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Community genetic testing prompts behavior change in patients
that could decrease an individual’s likelihood of developing chronic kidney disease (CKD) and end-stage renal failure (ESRF), a new pilot study suggests.
“Disclosing APOL1 genetic testing results to patients of African ancestry with hypertension and their clinicians was associated with a greater reduction in systolic blood pressure [SBP], increased kidney disease screening, and positive self-reported behavior change in those with high-risk genotypes,” Girish Nadkarni, MD, MPH, Icahn Mount Sinai School of Medicine, New York, and colleagues reported.
“These two measurements – the change in blood pressure and increased kidney function tests – act as hallmarks for detecting beneficial lifestyle change,” Dr. Nadkarni noted in a statement from his institution.
“For many years, researchers have wondered whether reporting APOL1 genetic test results would help improve clinical management. This is the first pragmatic randomized clinical trial to test this out [and] these results suggest we are headed in the right direction,” he added.
The study was published online March 4, 2022, in JAMA Network Open.
A quarter of those with high-risk genotype changed medication behavior
High-risk APOL1 genotypes confer a 5- to 10-fold increased risk for CKD and ESRF caused by hypertension and are found in one out of seven individuals of African ancestry. People of African ancestry also have the highest age-adjusted prevalence of high BP and the lowest rates of BP control, Dr. Nadkarni and colleagues wrote.
They studied a total of 2,050 patients of African ancestry with hypertension but without CKD who were randomized to undergo either immediate APOL1 testing (intervention group) or delayed APOL1 testing (control group).
“Patients randomly assigned to the intervention group received APOL1 genetic testing results from trained staff [while] their clinicians received results through clinical decision support in electronic health records,” the investigators explained.
Control patients received results after 12 months of follow-up. The mean age of the cohort was 53 years and almost two-thirds were female. Mean baseline SBP was significantly higher in patients with high-risk APOL1 genotypes, at 137 mm Hg, compared with those with low-risk APOL1 genotypes, at 134 mm Hg (P = .003), and controls, at 133 mm Hg (P = .001), the authors reported.
At 3 months, “all groups had some decrease in SBP,” Dr. Nadkarni and colleagues observed.
However, patients with high-risk APOL1 genotypes had a significantly greater decrease in SBP, at 6 mm Hg, compared with a mean decrease of 3 mm Hg for those with low-risk APOL1 genotypes (P = .004) as well as controls (P = .01). At 12 months, there was no significant difference in SBP or change in SBP from baseline to 12 months between the three groups.
“All three groups showed a significant increase in the rate of urine protein testing over time,” the authors added.
Again, however, the most significant increase in urine protein testing over time was seen in patients with high-risk APOL1 genotypes, with a 12% increase from baseline, compared with a 6% increase for patients with low-risk APOL1 genotypes and a 7% increase among controls. The difference was significant only between patients with high-risk APOL1 genotypes and controls (P = .01).
Significantly more patients with high-risk APOL1 genotypes, at 59%, reported making positive lifestyle changes as reflected in better dietary and exercise habits after receiving their test results than did those with low-risk APOL1 genotypes, at 37% (P < .001).
Moreover, 24% of those with high-risk genotypes reported that receiving test results changed how they take their BP medication, compared with only 10% of those with low-risk genotypes.
More high-risk genotype carriers also reported taking their medications more often, at 10%, compared with 5% of low-risk genotype carriers (P = .005).
On the other hand, more patients with the high-risk genotype, at 27%, worried that they would develop kidney problems than low-risk carriers, at 17% (P < .001). Although investigators did offer patients the opportunity to speak with a genetic counselor at no cost, none chose to do so, the authors noted.
Small improvements
As the investigators emphasized, the magnitude of BP improvement seen in high-risk APOL1 carriers was small. However, they did not provide specific BP target recommendations or BP-lowering strategies, which, had they done so, may have brought BP down to a greater degree.
Health behavior changes were similarly small and may not have been clinically that meaningful.
Still, “results suggest that the trial clearly influenced those who received positive results and may have had some positive effects on other patients,” Dr. Nadkarni concluded.
Dr. Nadkarni is a cofounder of and has equity in Renalytx, and has been a member of the scientific advisory board and received personal fees from the company. He is also a cofounder of Pensieve Health.
A version of this article first appeared on Medscape.com.
that could decrease an individual’s likelihood of developing chronic kidney disease (CKD) and end-stage renal failure (ESRF), a new pilot study suggests.
“Disclosing APOL1 genetic testing results to patients of African ancestry with hypertension and their clinicians was associated with a greater reduction in systolic blood pressure [SBP], increased kidney disease screening, and positive self-reported behavior change in those with high-risk genotypes,” Girish Nadkarni, MD, MPH, Icahn Mount Sinai School of Medicine, New York, and colleagues reported.
“These two measurements – the change in blood pressure and increased kidney function tests – act as hallmarks for detecting beneficial lifestyle change,” Dr. Nadkarni noted in a statement from his institution.
“For many years, researchers have wondered whether reporting APOL1 genetic test results would help improve clinical management. This is the first pragmatic randomized clinical trial to test this out [and] these results suggest we are headed in the right direction,” he added.
The study was published online March 4, 2022, in JAMA Network Open.
A quarter of those with high-risk genotype changed medication behavior
High-risk APOL1 genotypes confer a 5- to 10-fold increased risk for CKD and ESRF caused by hypertension and are found in one out of seven individuals of African ancestry. People of African ancestry also have the highest age-adjusted prevalence of high BP and the lowest rates of BP control, Dr. Nadkarni and colleagues wrote.
They studied a total of 2,050 patients of African ancestry with hypertension but without CKD who were randomized to undergo either immediate APOL1 testing (intervention group) or delayed APOL1 testing (control group).
“Patients randomly assigned to the intervention group received APOL1 genetic testing results from trained staff [while] their clinicians received results through clinical decision support in electronic health records,” the investigators explained.
Control patients received results after 12 months of follow-up. The mean age of the cohort was 53 years and almost two-thirds were female. Mean baseline SBP was significantly higher in patients with high-risk APOL1 genotypes, at 137 mm Hg, compared with those with low-risk APOL1 genotypes, at 134 mm Hg (P = .003), and controls, at 133 mm Hg (P = .001), the authors reported.
At 3 months, “all groups had some decrease in SBP,” Dr. Nadkarni and colleagues observed.
However, patients with high-risk APOL1 genotypes had a significantly greater decrease in SBP, at 6 mm Hg, compared with a mean decrease of 3 mm Hg for those with low-risk APOL1 genotypes (P = .004) as well as controls (P = .01). At 12 months, there was no significant difference in SBP or change in SBP from baseline to 12 months between the three groups.
“All three groups showed a significant increase in the rate of urine protein testing over time,” the authors added.
Again, however, the most significant increase in urine protein testing over time was seen in patients with high-risk APOL1 genotypes, with a 12% increase from baseline, compared with a 6% increase for patients with low-risk APOL1 genotypes and a 7% increase among controls. The difference was significant only between patients with high-risk APOL1 genotypes and controls (P = .01).
Significantly more patients with high-risk APOL1 genotypes, at 59%, reported making positive lifestyle changes as reflected in better dietary and exercise habits after receiving their test results than did those with low-risk APOL1 genotypes, at 37% (P < .001).
Moreover, 24% of those with high-risk genotypes reported that receiving test results changed how they take their BP medication, compared with only 10% of those with low-risk genotypes.
More high-risk genotype carriers also reported taking their medications more often, at 10%, compared with 5% of low-risk genotype carriers (P = .005).
On the other hand, more patients with the high-risk genotype, at 27%, worried that they would develop kidney problems than low-risk carriers, at 17% (P < .001). Although investigators did offer patients the opportunity to speak with a genetic counselor at no cost, none chose to do so, the authors noted.
Small improvements
As the investigators emphasized, the magnitude of BP improvement seen in high-risk APOL1 carriers was small. However, they did not provide specific BP target recommendations or BP-lowering strategies, which, had they done so, may have brought BP down to a greater degree.
Health behavior changes were similarly small and may not have been clinically that meaningful.
Still, “results suggest that the trial clearly influenced those who received positive results and may have had some positive effects on other patients,” Dr. Nadkarni concluded.
Dr. Nadkarni is a cofounder of and has equity in Renalytx, and has been a member of the scientific advisory board and received personal fees from the company. He is also a cofounder of Pensieve Health.
A version of this article first appeared on Medscape.com.
that could decrease an individual’s likelihood of developing chronic kidney disease (CKD) and end-stage renal failure (ESRF), a new pilot study suggests.
“Disclosing APOL1 genetic testing results to patients of African ancestry with hypertension and their clinicians was associated with a greater reduction in systolic blood pressure [SBP], increased kidney disease screening, and positive self-reported behavior change in those with high-risk genotypes,” Girish Nadkarni, MD, MPH, Icahn Mount Sinai School of Medicine, New York, and colleagues reported.
“These two measurements – the change in blood pressure and increased kidney function tests – act as hallmarks for detecting beneficial lifestyle change,” Dr. Nadkarni noted in a statement from his institution.
“For many years, researchers have wondered whether reporting APOL1 genetic test results would help improve clinical management. This is the first pragmatic randomized clinical trial to test this out [and] these results suggest we are headed in the right direction,” he added.
The study was published online March 4, 2022, in JAMA Network Open.
A quarter of those with high-risk genotype changed medication behavior
High-risk APOL1 genotypes confer a 5- to 10-fold increased risk for CKD and ESRF caused by hypertension and are found in one out of seven individuals of African ancestry. People of African ancestry also have the highest age-adjusted prevalence of high BP and the lowest rates of BP control, Dr. Nadkarni and colleagues wrote.
They studied a total of 2,050 patients of African ancestry with hypertension but without CKD who were randomized to undergo either immediate APOL1 testing (intervention group) or delayed APOL1 testing (control group).
“Patients randomly assigned to the intervention group received APOL1 genetic testing results from trained staff [while] their clinicians received results through clinical decision support in electronic health records,” the investigators explained.
Control patients received results after 12 months of follow-up. The mean age of the cohort was 53 years and almost two-thirds were female. Mean baseline SBP was significantly higher in patients with high-risk APOL1 genotypes, at 137 mm Hg, compared with those with low-risk APOL1 genotypes, at 134 mm Hg (P = .003), and controls, at 133 mm Hg (P = .001), the authors reported.
At 3 months, “all groups had some decrease in SBP,” Dr. Nadkarni and colleagues observed.
However, patients with high-risk APOL1 genotypes had a significantly greater decrease in SBP, at 6 mm Hg, compared with a mean decrease of 3 mm Hg for those with low-risk APOL1 genotypes (P = .004) as well as controls (P = .01). At 12 months, there was no significant difference in SBP or change in SBP from baseline to 12 months between the three groups.
“All three groups showed a significant increase in the rate of urine protein testing over time,” the authors added.
Again, however, the most significant increase in urine protein testing over time was seen in patients with high-risk APOL1 genotypes, with a 12% increase from baseline, compared with a 6% increase for patients with low-risk APOL1 genotypes and a 7% increase among controls. The difference was significant only between patients with high-risk APOL1 genotypes and controls (P = .01).
Significantly more patients with high-risk APOL1 genotypes, at 59%, reported making positive lifestyle changes as reflected in better dietary and exercise habits after receiving their test results than did those with low-risk APOL1 genotypes, at 37% (P < .001).
Moreover, 24% of those with high-risk genotypes reported that receiving test results changed how they take their BP medication, compared with only 10% of those with low-risk genotypes.
More high-risk genotype carriers also reported taking their medications more often, at 10%, compared with 5% of low-risk genotype carriers (P = .005).
On the other hand, more patients with the high-risk genotype, at 27%, worried that they would develop kidney problems than low-risk carriers, at 17% (P < .001). Although investigators did offer patients the opportunity to speak with a genetic counselor at no cost, none chose to do so, the authors noted.
Small improvements
As the investigators emphasized, the magnitude of BP improvement seen in high-risk APOL1 carriers was small. However, they did not provide specific BP target recommendations or BP-lowering strategies, which, had they done so, may have brought BP down to a greater degree.
Health behavior changes were similarly small and may not have been clinically that meaningful.
Still, “results suggest that the trial clearly influenced those who received positive results and may have had some positive effects on other patients,” Dr. Nadkarni concluded.
Dr. Nadkarni is a cofounder of and has equity in Renalytx, and has been a member of the scientific advisory board and received personal fees from the company. He is also a cofounder of Pensieve Health.
A version of this article first appeared on Medscape.com.
FROM JAMA NETWORK OPEN
Finerenone + SGLT2 inhibitor of benefit in diabetes with CKD?
New signals of a potential additive benefit from the nonsteroidal mineralocorticoid antagonist finerenone (Kerendia) and a sodium-glucose transporter 2 inhibitor in patients with type 2 diabetes and chronic kidney disease (CKD) emerged in a follow-up report from the FIDELITY analysis, which combined data from more than 13,000 patients who received finerenone in either of the two pivotal trials with the agent.
The analysis showed that the 877 patients enrolled in either the FIDELIO DKD or FIGARO DKD trials taking an SGLT2 inhibitor at baseline had a 37% relative reduction in their urinary albumin-to-creatinine ratio (UACR), compared with placebo-treated patients after a median of 3 years on treatment.
Among the remaining 12,149 patients who did not receive an SGLT2 inhibitor, finerenone cut the average UACR by 32%, compared with placebo, said Peter Rossing, DMSc, MD, who presented the findings on Feb. 27 at the World Congress of Nephrology 2022 in Kuala Lumpur, Malaysia.
Primary endpoint results for FIDELIO-DKD and FIGARO-DKD also suggest similar additive effects of finerenone plus an SGLT2 inhibitor.
Results of the composite renal endpoint in each study – progression to kidney failure, renal death, or at least a 57% decline in estimated glomerular filtration rate (eGFR) from baseline – showed a 58% relative risk reduction in patients who received agents from both drug classes and a 20% relative risk reduction in those who only received finerenone, a between-group difference that was not significant.
For the composite cardiovascular event endpoint – cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure – the rate fell by 37%, compared with placebo, in patients who also received an SGLT2 inhibitor, and by 13%, compared with placebo, in those who received finerenone but no SGLT2 inhibitor, also a difference that was not significant.
‘A lot of interest in finerenone’ in U.S.
“The benefits of finerenone on cardiovascular and kidney outcomes were consistent, irrespective of SGLT2 inhibitor use at baseline,” concluded Dr. Rossing, professor and head of research at the Steno Diabetes Center in Copenhagen.
The new findings are a “suggestion that the two classes might be additive [in their effects], but more data are needed,” Dr. Rossing said during his presentation.
But he cautioned that in both pivotal trials randomization did not consider SGLT2 inhibitor use. All patients in the two trials were already receiving a renin-angiotensin system (RAS) inhibitor as background treatment, either an ACE inhibitor or angiotensin-receptor blocker.
The consequence of treatment with finerenone combined with an SGLT2 inhibitor is of growing importance because “an SGLT2 inhibitor is now recommended in most guidelines” for the type of patients enrolled in the two finerenone trials, explained Dr. Rossing.
He also noted that the first guideline to recommend routine use of finerenone in indicated patients appeared recently in the annual update to Standards of Medical Care in Diabetes – 2022 published by the American Diabetes Association.
The 2022 Standards states: “In patients with CKD who are at increased risk for cardiovascular events or CKD progression or are unable to use an SGLT2 inhibitor, a nonsteroidal mineralocorticoid receptor antagonist (finerenone) is recommended to reduce CKD progression and cardiovascular events.”
Results from FIDELIO-DKD, reported in the New England Journal of Medicine in 2020, and the main study, FIGARO-DKD, published in the same journal in 2021, led the Food and Drug Administration to approve finerenone in July 2021 to slow the progression of renal disease in patients with type 2 diabetes and CKD.
“My impression is that in the United States there is a lot of interest in finerenone,” Dr. Rossing said during the discussion following his presentation.
Finerenone has also been recently approved in the European Union.
‘Consistent’ benefits irrespective of SGLT2 inhibitors
“The cardiovascular and kidney benefits of finerenone were consistent irrespective of SGLT2 inhibitor use. This is definitely interesting and warrants a randomized controlled trial” to examine the relationship in a more rigorous way, commented Tejas Desai, MD, a nephrologist with the Department of Veterans Affairs, Charlotte, N.C.
That study, CONFIDENCE, is on its way, Dr. Rossing said during his talk. The randomized phase 2 trial has a planned enrollment of 800 patients with type 2 diabetes and CKD and three treatment groups: finerenone plus placebo, the SGLT2 inhibitor empagliflozin (Jardiance) plus placebo, or finerenone plus empagliflozin. The study will launch later in 2022 and has a planned completion date of late 2023.
“SGLT2 inhibitors, compared with finerenone, is where all of this is headed. We need a large trial that adjudicates the best medication to use with a RAS inhibitor,” Dr. Desai said in an interview.
The new analyses from the combined FIDELITY study expand on a previous report presented at the 2021 annual congress of the European Society of Cardiology and published in the European Heart Journal.
‘Impressive’ effect on cardiovascular events
The main findings from FIDELITY presented in those earlier reports, in 13,026 patients, showed there was a significant 14% relative reduction in the composite cardiovascular endpoint with finerenone, compared with placebo, during a median 3 years of follow-up.
The same report documented, in the total combined cohort, a significant 23% relative reduction in the composite renal endpoint in those taking finerenone compared with placebo.
“Reducing the risk of cardiovascular endpoints by a relative 14% is impressive,” and the time course showed a “relatively quick onset of action,” Dr. Desai noted.
He also characterized the enrolled patients, which included many with stage 3 or 4 CKD, as “not the sickest population of patients with CKD,” but rather “relatively healthier patients with CKD.”
Dr. Desai also downplayed the importance of the observed reduction in UACR associated with finerenone in FIDELITY.
“UACR is a surrogate marker. Results from many studies have shown improvements in UACR only to not show protection against falls in eGFR rate,” Dr. Desai said.
He was also reassured by the low incidence of hyperkalemia that led to discontinuation, which occurred in 1.7% of patients taking finerenone and in 0.6% of those taking placebo.
The types of patients enrolled in FIDELIO-DKD and FIGARO-DKD, who did not have eGFR rates below 25 mL/min per 1.73 m2, are not particularly susceptible to this adverse effect, he said, noting, “I’m not overly concerned with hyperkalemia in this CKD population.
“I’m more concerned about [hyperkalemia in] patients with CKD and an eGFR of less than 25 mL/min per 1.73 m2, but this was less than 1% of the enrolled population,” Dr. Desai observed.
FIDELIO-DKD, FIGARO-DKD, and FIDELITY were sponsored by Bayer, which markets finerenone (Kerendia). Dr. Rossing reported being a consultant for Bayer and other drug companies, and receiving research funding from AstraZeneca and Novo Nordisk. Dr. Desai reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.
New signals of a potential additive benefit from the nonsteroidal mineralocorticoid antagonist finerenone (Kerendia) and a sodium-glucose transporter 2 inhibitor in patients with type 2 diabetes and chronic kidney disease (CKD) emerged in a follow-up report from the FIDELITY analysis, which combined data from more than 13,000 patients who received finerenone in either of the two pivotal trials with the agent.
The analysis showed that the 877 patients enrolled in either the FIDELIO DKD or FIGARO DKD trials taking an SGLT2 inhibitor at baseline had a 37% relative reduction in their urinary albumin-to-creatinine ratio (UACR), compared with placebo-treated patients after a median of 3 years on treatment.
Among the remaining 12,149 patients who did not receive an SGLT2 inhibitor, finerenone cut the average UACR by 32%, compared with placebo, said Peter Rossing, DMSc, MD, who presented the findings on Feb. 27 at the World Congress of Nephrology 2022 in Kuala Lumpur, Malaysia.
Primary endpoint results for FIDELIO-DKD and FIGARO-DKD also suggest similar additive effects of finerenone plus an SGLT2 inhibitor.
Results of the composite renal endpoint in each study – progression to kidney failure, renal death, or at least a 57% decline in estimated glomerular filtration rate (eGFR) from baseline – showed a 58% relative risk reduction in patients who received agents from both drug classes and a 20% relative risk reduction in those who only received finerenone, a between-group difference that was not significant.
For the composite cardiovascular event endpoint – cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure – the rate fell by 37%, compared with placebo, in patients who also received an SGLT2 inhibitor, and by 13%, compared with placebo, in those who received finerenone but no SGLT2 inhibitor, also a difference that was not significant.
‘A lot of interest in finerenone’ in U.S.
“The benefits of finerenone on cardiovascular and kidney outcomes were consistent, irrespective of SGLT2 inhibitor use at baseline,” concluded Dr. Rossing, professor and head of research at the Steno Diabetes Center in Copenhagen.
The new findings are a “suggestion that the two classes might be additive [in their effects], but more data are needed,” Dr. Rossing said during his presentation.
But he cautioned that in both pivotal trials randomization did not consider SGLT2 inhibitor use. All patients in the two trials were already receiving a renin-angiotensin system (RAS) inhibitor as background treatment, either an ACE inhibitor or angiotensin-receptor blocker.
The consequence of treatment with finerenone combined with an SGLT2 inhibitor is of growing importance because “an SGLT2 inhibitor is now recommended in most guidelines” for the type of patients enrolled in the two finerenone trials, explained Dr. Rossing.
He also noted that the first guideline to recommend routine use of finerenone in indicated patients appeared recently in the annual update to Standards of Medical Care in Diabetes – 2022 published by the American Diabetes Association.
The 2022 Standards states: “In patients with CKD who are at increased risk for cardiovascular events or CKD progression or are unable to use an SGLT2 inhibitor, a nonsteroidal mineralocorticoid receptor antagonist (finerenone) is recommended to reduce CKD progression and cardiovascular events.”
Results from FIDELIO-DKD, reported in the New England Journal of Medicine in 2020, and the main study, FIGARO-DKD, published in the same journal in 2021, led the Food and Drug Administration to approve finerenone in July 2021 to slow the progression of renal disease in patients with type 2 diabetes and CKD.
“My impression is that in the United States there is a lot of interest in finerenone,” Dr. Rossing said during the discussion following his presentation.
Finerenone has also been recently approved in the European Union.
‘Consistent’ benefits irrespective of SGLT2 inhibitors
“The cardiovascular and kidney benefits of finerenone were consistent irrespective of SGLT2 inhibitor use. This is definitely interesting and warrants a randomized controlled trial” to examine the relationship in a more rigorous way, commented Tejas Desai, MD, a nephrologist with the Department of Veterans Affairs, Charlotte, N.C.
That study, CONFIDENCE, is on its way, Dr. Rossing said during his talk. The randomized phase 2 trial has a planned enrollment of 800 patients with type 2 diabetes and CKD and three treatment groups: finerenone plus placebo, the SGLT2 inhibitor empagliflozin (Jardiance) plus placebo, or finerenone plus empagliflozin. The study will launch later in 2022 and has a planned completion date of late 2023.
“SGLT2 inhibitors, compared with finerenone, is where all of this is headed. We need a large trial that adjudicates the best medication to use with a RAS inhibitor,” Dr. Desai said in an interview.
The new analyses from the combined FIDELITY study expand on a previous report presented at the 2021 annual congress of the European Society of Cardiology and published in the European Heart Journal.
‘Impressive’ effect on cardiovascular events
The main findings from FIDELITY presented in those earlier reports, in 13,026 patients, showed there was a significant 14% relative reduction in the composite cardiovascular endpoint with finerenone, compared with placebo, during a median 3 years of follow-up.
The same report documented, in the total combined cohort, a significant 23% relative reduction in the composite renal endpoint in those taking finerenone compared with placebo.
“Reducing the risk of cardiovascular endpoints by a relative 14% is impressive,” and the time course showed a “relatively quick onset of action,” Dr. Desai noted.
He also characterized the enrolled patients, which included many with stage 3 or 4 CKD, as “not the sickest population of patients with CKD,” but rather “relatively healthier patients with CKD.”
Dr. Desai also downplayed the importance of the observed reduction in UACR associated with finerenone in FIDELITY.
“UACR is a surrogate marker. Results from many studies have shown improvements in UACR only to not show protection against falls in eGFR rate,” Dr. Desai said.
He was also reassured by the low incidence of hyperkalemia that led to discontinuation, which occurred in 1.7% of patients taking finerenone and in 0.6% of those taking placebo.
The types of patients enrolled in FIDELIO-DKD and FIGARO-DKD, who did not have eGFR rates below 25 mL/min per 1.73 m2, are not particularly susceptible to this adverse effect, he said, noting, “I’m not overly concerned with hyperkalemia in this CKD population.
“I’m more concerned about [hyperkalemia in] patients with CKD and an eGFR of less than 25 mL/min per 1.73 m2, but this was less than 1% of the enrolled population,” Dr. Desai observed.
FIDELIO-DKD, FIGARO-DKD, and FIDELITY were sponsored by Bayer, which markets finerenone (Kerendia). Dr. Rossing reported being a consultant for Bayer and other drug companies, and receiving research funding from AstraZeneca and Novo Nordisk. Dr. Desai reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.
New signals of a potential additive benefit from the nonsteroidal mineralocorticoid antagonist finerenone (Kerendia) and a sodium-glucose transporter 2 inhibitor in patients with type 2 diabetes and chronic kidney disease (CKD) emerged in a follow-up report from the FIDELITY analysis, which combined data from more than 13,000 patients who received finerenone in either of the two pivotal trials with the agent.
The analysis showed that the 877 patients enrolled in either the FIDELIO DKD or FIGARO DKD trials taking an SGLT2 inhibitor at baseline had a 37% relative reduction in their urinary albumin-to-creatinine ratio (UACR), compared with placebo-treated patients after a median of 3 years on treatment.
Among the remaining 12,149 patients who did not receive an SGLT2 inhibitor, finerenone cut the average UACR by 32%, compared with placebo, said Peter Rossing, DMSc, MD, who presented the findings on Feb. 27 at the World Congress of Nephrology 2022 in Kuala Lumpur, Malaysia.
Primary endpoint results for FIDELIO-DKD and FIGARO-DKD also suggest similar additive effects of finerenone plus an SGLT2 inhibitor.
Results of the composite renal endpoint in each study – progression to kidney failure, renal death, or at least a 57% decline in estimated glomerular filtration rate (eGFR) from baseline – showed a 58% relative risk reduction in patients who received agents from both drug classes and a 20% relative risk reduction in those who only received finerenone, a between-group difference that was not significant.
For the composite cardiovascular event endpoint – cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure – the rate fell by 37%, compared with placebo, in patients who also received an SGLT2 inhibitor, and by 13%, compared with placebo, in those who received finerenone but no SGLT2 inhibitor, also a difference that was not significant.
‘A lot of interest in finerenone’ in U.S.
“The benefits of finerenone on cardiovascular and kidney outcomes were consistent, irrespective of SGLT2 inhibitor use at baseline,” concluded Dr. Rossing, professor and head of research at the Steno Diabetes Center in Copenhagen.
The new findings are a “suggestion that the two classes might be additive [in their effects], but more data are needed,” Dr. Rossing said during his presentation.
But he cautioned that in both pivotal trials randomization did not consider SGLT2 inhibitor use. All patients in the two trials were already receiving a renin-angiotensin system (RAS) inhibitor as background treatment, either an ACE inhibitor or angiotensin-receptor blocker.
The consequence of treatment with finerenone combined with an SGLT2 inhibitor is of growing importance because “an SGLT2 inhibitor is now recommended in most guidelines” for the type of patients enrolled in the two finerenone trials, explained Dr. Rossing.
He also noted that the first guideline to recommend routine use of finerenone in indicated patients appeared recently in the annual update to Standards of Medical Care in Diabetes – 2022 published by the American Diabetes Association.
The 2022 Standards states: “In patients with CKD who are at increased risk for cardiovascular events or CKD progression or are unable to use an SGLT2 inhibitor, a nonsteroidal mineralocorticoid receptor antagonist (finerenone) is recommended to reduce CKD progression and cardiovascular events.”
Results from FIDELIO-DKD, reported in the New England Journal of Medicine in 2020, and the main study, FIGARO-DKD, published in the same journal in 2021, led the Food and Drug Administration to approve finerenone in July 2021 to slow the progression of renal disease in patients with type 2 diabetes and CKD.
“My impression is that in the United States there is a lot of interest in finerenone,” Dr. Rossing said during the discussion following his presentation.
Finerenone has also been recently approved in the European Union.
‘Consistent’ benefits irrespective of SGLT2 inhibitors
“The cardiovascular and kidney benefits of finerenone were consistent irrespective of SGLT2 inhibitor use. This is definitely interesting and warrants a randomized controlled trial” to examine the relationship in a more rigorous way, commented Tejas Desai, MD, a nephrologist with the Department of Veterans Affairs, Charlotte, N.C.
That study, CONFIDENCE, is on its way, Dr. Rossing said during his talk. The randomized phase 2 trial has a planned enrollment of 800 patients with type 2 diabetes and CKD and three treatment groups: finerenone plus placebo, the SGLT2 inhibitor empagliflozin (Jardiance) plus placebo, or finerenone plus empagliflozin. The study will launch later in 2022 and has a planned completion date of late 2023.
“SGLT2 inhibitors, compared with finerenone, is where all of this is headed. We need a large trial that adjudicates the best medication to use with a RAS inhibitor,” Dr. Desai said in an interview.
The new analyses from the combined FIDELITY study expand on a previous report presented at the 2021 annual congress of the European Society of Cardiology and published in the European Heart Journal.
‘Impressive’ effect on cardiovascular events
The main findings from FIDELITY presented in those earlier reports, in 13,026 patients, showed there was a significant 14% relative reduction in the composite cardiovascular endpoint with finerenone, compared with placebo, during a median 3 years of follow-up.
The same report documented, in the total combined cohort, a significant 23% relative reduction in the composite renal endpoint in those taking finerenone compared with placebo.
“Reducing the risk of cardiovascular endpoints by a relative 14% is impressive,” and the time course showed a “relatively quick onset of action,” Dr. Desai noted.
He also characterized the enrolled patients, which included many with stage 3 or 4 CKD, as “not the sickest population of patients with CKD,” but rather “relatively healthier patients with CKD.”
Dr. Desai also downplayed the importance of the observed reduction in UACR associated with finerenone in FIDELITY.
“UACR is a surrogate marker. Results from many studies have shown improvements in UACR only to not show protection against falls in eGFR rate,” Dr. Desai said.
He was also reassured by the low incidence of hyperkalemia that led to discontinuation, which occurred in 1.7% of patients taking finerenone and in 0.6% of those taking placebo.
The types of patients enrolled in FIDELIO-DKD and FIGARO-DKD, who did not have eGFR rates below 25 mL/min per 1.73 m2, are not particularly susceptible to this adverse effect, he said, noting, “I’m not overly concerned with hyperkalemia in this CKD population.
“I’m more concerned about [hyperkalemia in] patients with CKD and an eGFR of less than 25 mL/min per 1.73 m2, but this was less than 1% of the enrolled population,” Dr. Desai observed.
FIDELIO-DKD, FIGARO-DKD, and FIDELITY were sponsored by Bayer, which markets finerenone (Kerendia). Dr. Rossing reported being a consultant for Bayer and other drug companies, and receiving research funding from AstraZeneca and Novo Nordisk. Dr. Desai reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.
FROM THE WORLD CONGRESS OF NEPHROLOGY
What is the healthiest salt for you?
When we refer to “regular table salt,” it is most commonly in the form of sodium chloride, which is also a major constituent of packaged and ultraprocessed foods.
The best approach to finding the “healthiest salt” – which really means the lowest in sodium – is to look for the amount on the label. “Sodium-free” usually indicates less than 5 mg of sodium per serving, and “low-sodium” usually means 140 mg or less per serving. In contrast, regular table salt can contain as much as 560 mg of sodium in one serving.
Other en vogue salts, such as pink Himalayan salt, sea salt, and kosher salt, are high in sodium content – like regular table salt – but because of their larger crystal size, less sodium is delivered per serving.
Most salt substitutes are reduced in sodium, with the addition of potassium chloride instead.
FDA issues guidance on reducing salt
Currently, the U.S. sodium dietary guidelines for persons older than 14 stipulate 2,300 mg/d, which is equivalent to 1 teaspoon a day. However it is estimated that the average person in the United States consumes more than this – around 3,400 mg of sodium daily.
In October 2021, the U.S. Food and Drug Administration published guidance on voluntary sodium limitations in commercially processed, packaged, and prepared food. The FDA’s short-term approach is to slowly reduce exposure to sodium in processed and restaurant food by 2025, on the basis that people will eventually get used to less salt, as has happened in the United Kingdom and other countries.
Such strategies to reduce salt intake are now being used in national programs in several countries. Many of these successful initiatives include active engagement with the food industry to reduce the amount of sodium added to processed food, as well as public awareness campaigns to alert consumers to the dangers of eating too much salt. This includes increasing potassium in manufactured foods, primarily to target hypertension and heart disease, as described by Clare Farrand, MSc, BSc, and colleagues, in the Journal of Clinical Hypertension. The authors also make several recommendations regarding salt reduction policies:
- Food manufacturers should gradually reduce sodium in food to the lowest possible levels and explore the use of potassium-based sodium replacers to reduce sodium levels even further.
- Governments should continue to monitor sodium and potassium levels in processed foods.
- Further consideration may need to be given to how best to label salt substitutes (namely potassium) in processed foods to ensure that people who may be adversely affected are aware.
- Governments should systematically monitor potassium intake at the population level, including for specific susceptible groups.
- Governments should continue to systematically monitor sodium (salt) intake and iodine intake at the population level to adjust salt iodization over time as necessary, depending on observed salt intake in specific targeted groups, to ensure that they have sufficient but not excessive iodine intakes as salt intakes are reduced.
- Governments should consider opportunities for promoting and subsidizing salt substitutes, particularly in countries where salt added during cooking or at the table is the major source of salt in the diet.
The new FDA document includes 163 subcategories of foods in its voluntary salt reduction strategy.
Salt substitutes, high blood pressure, and mortality
Lowering sodium intake is almost certainly beneficial for persons with high blood pressure. In 2020, a review in Hypertension highlighted the benefit of salt substitutes in reducing hypertension, reporting that they lower systolic blood pressure by 5.58 mm Hg and diastolic blood pressure by 2.88 mm Hg.
And changes to dietary sodium intake can potentially reduce or obviate the need for medications for essential hypertension in some individuals. Although there are only a few studies on this topic, a study by Bruce Neal, MB, ChB, PhD, and colleagues, revealed a reduction in stroke, cardiovascular events, and deaths with the use of potassium-based salt substitutes.
Salt substitutes and sodium and potassium handling in the kidneys
Many studies have shown that potassium-rich salt substitutes are safe in individuals with normal kidney function, but are they safe and beneficial for people with chronic kidney disease (CKD)?
For anyone who is on a renal diet, potassium and sodium intake goals are limited according to their absolute level of kidney function.
There have been case reports of life-threatening blood potassium levels (hyperkalemia) due to potassium-rich salt substitutes in people with CKD, but no larger published studies on this topic can be found.
A diet modeling study by Rebecca Morrison and colleagues evaluated varying degrees of potassium-enriched salt substituted bread products and their impact on dietary intake in persons with CKD. They used dietary data from the National Nutrition and Physical Activity Survey 2011-2012 in Australia for 12,152 participants, 154 of whom had CKD. Replacing the sodium in bread with varying amounts of potassium chloride (20%, 30%, and 40%) would result in one-third of people with CKD exceeding the safe limits for dietary potassium consumption (31.8%, 32.6%, and 33%, respectively), they found.
“Potassium chloride substitution in staple foods such as bread and bread products have serious and potentially fatal consequences for people who need to restrict dietary potassium. Improved food labelling is required for consumers to avoid excessive consumption,” Ms. Morrison and colleagues concluded. They added that more studies are needed to further understand the risks of potassium dietary intake and hyperkalemia in CKD from potassium-based salt substitutes.
The American Heart Association recommends no more than 1,500 mg of sodium intake daily for persons with CKD, diabetes, or high blood pressure; those older than 51; and African American persons of any age.
The recommended daily intake of potassium in persons with CKD can range from 2,000 mg to 4,000 mg, depending on the individual and their degree of CKD. The potassium content in some salt substitutes varies from 440 mg to 2,800 mg per teaspoon.
The best recommendation for individuals with CKD and a goal to reduce their sodium intake is to use herbs and lower-sodium seasonings as a substitute, but these should always be reviewed with their physician and renal nutritionist.
Dr. Brookins is a board-certified nephrologist and internist practicing in Georgia. She is the founder and owner of Remote Renal Care, a telehealth kidney practice. She reported no relevant conflicts of interest.
A version of this article first appeared on Medscape.com.
When we refer to “regular table salt,” it is most commonly in the form of sodium chloride, which is also a major constituent of packaged and ultraprocessed foods.
The best approach to finding the “healthiest salt” – which really means the lowest in sodium – is to look for the amount on the label. “Sodium-free” usually indicates less than 5 mg of sodium per serving, and “low-sodium” usually means 140 mg or less per serving. In contrast, regular table salt can contain as much as 560 mg of sodium in one serving.
Other en vogue salts, such as pink Himalayan salt, sea salt, and kosher salt, are high in sodium content – like regular table salt – but because of their larger crystal size, less sodium is delivered per serving.
Most salt substitutes are reduced in sodium, with the addition of potassium chloride instead.
FDA issues guidance on reducing salt
Currently, the U.S. sodium dietary guidelines for persons older than 14 stipulate 2,300 mg/d, which is equivalent to 1 teaspoon a day. However it is estimated that the average person in the United States consumes more than this – around 3,400 mg of sodium daily.
In October 2021, the U.S. Food and Drug Administration published guidance on voluntary sodium limitations in commercially processed, packaged, and prepared food. The FDA’s short-term approach is to slowly reduce exposure to sodium in processed and restaurant food by 2025, on the basis that people will eventually get used to less salt, as has happened in the United Kingdom and other countries.
Such strategies to reduce salt intake are now being used in national programs in several countries. Many of these successful initiatives include active engagement with the food industry to reduce the amount of sodium added to processed food, as well as public awareness campaigns to alert consumers to the dangers of eating too much salt. This includes increasing potassium in manufactured foods, primarily to target hypertension and heart disease, as described by Clare Farrand, MSc, BSc, and colleagues, in the Journal of Clinical Hypertension. The authors also make several recommendations regarding salt reduction policies:
- Food manufacturers should gradually reduce sodium in food to the lowest possible levels and explore the use of potassium-based sodium replacers to reduce sodium levels even further.
- Governments should continue to monitor sodium and potassium levels in processed foods.
- Further consideration may need to be given to how best to label salt substitutes (namely potassium) in processed foods to ensure that people who may be adversely affected are aware.
- Governments should systematically monitor potassium intake at the population level, including for specific susceptible groups.
- Governments should continue to systematically monitor sodium (salt) intake and iodine intake at the population level to adjust salt iodization over time as necessary, depending on observed salt intake in specific targeted groups, to ensure that they have sufficient but not excessive iodine intakes as salt intakes are reduced.
- Governments should consider opportunities for promoting and subsidizing salt substitutes, particularly in countries where salt added during cooking or at the table is the major source of salt in the diet.
The new FDA document includes 163 subcategories of foods in its voluntary salt reduction strategy.
Salt substitutes, high blood pressure, and mortality
Lowering sodium intake is almost certainly beneficial for persons with high blood pressure. In 2020, a review in Hypertension highlighted the benefit of salt substitutes in reducing hypertension, reporting that they lower systolic blood pressure by 5.58 mm Hg and diastolic blood pressure by 2.88 mm Hg.
And changes to dietary sodium intake can potentially reduce or obviate the need for medications for essential hypertension in some individuals. Although there are only a few studies on this topic, a study by Bruce Neal, MB, ChB, PhD, and colleagues, revealed a reduction in stroke, cardiovascular events, and deaths with the use of potassium-based salt substitutes.
Salt substitutes and sodium and potassium handling in the kidneys
Many studies have shown that potassium-rich salt substitutes are safe in individuals with normal kidney function, but are they safe and beneficial for people with chronic kidney disease (CKD)?
For anyone who is on a renal diet, potassium and sodium intake goals are limited according to their absolute level of kidney function.
There have been case reports of life-threatening blood potassium levels (hyperkalemia) due to potassium-rich salt substitutes in people with CKD, but no larger published studies on this topic can be found.
A diet modeling study by Rebecca Morrison and colleagues evaluated varying degrees of potassium-enriched salt substituted bread products and their impact on dietary intake in persons with CKD. They used dietary data from the National Nutrition and Physical Activity Survey 2011-2012 in Australia for 12,152 participants, 154 of whom had CKD. Replacing the sodium in bread with varying amounts of potassium chloride (20%, 30%, and 40%) would result in one-third of people with CKD exceeding the safe limits for dietary potassium consumption (31.8%, 32.6%, and 33%, respectively), they found.
“Potassium chloride substitution in staple foods such as bread and bread products have serious and potentially fatal consequences for people who need to restrict dietary potassium. Improved food labelling is required for consumers to avoid excessive consumption,” Ms. Morrison and colleagues concluded. They added that more studies are needed to further understand the risks of potassium dietary intake and hyperkalemia in CKD from potassium-based salt substitutes.
The American Heart Association recommends no more than 1,500 mg of sodium intake daily for persons with CKD, diabetes, or high blood pressure; those older than 51; and African American persons of any age.
The recommended daily intake of potassium in persons with CKD can range from 2,000 mg to 4,000 mg, depending on the individual and their degree of CKD. The potassium content in some salt substitutes varies from 440 mg to 2,800 mg per teaspoon.
The best recommendation for individuals with CKD and a goal to reduce their sodium intake is to use herbs and lower-sodium seasonings as a substitute, but these should always be reviewed with their physician and renal nutritionist.
Dr. Brookins is a board-certified nephrologist and internist practicing in Georgia. She is the founder and owner of Remote Renal Care, a telehealth kidney practice. She reported no relevant conflicts of interest.
A version of this article first appeared on Medscape.com.
When we refer to “regular table salt,” it is most commonly in the form of sodium chloride, which is also a major constituent of packaged and ultraprocessed foods.
The best approach to finding the “healthiest salt” – which really means the lowest in sodium – is to look for the amount on the label. “Sodium-free” usually indicates less than 5 mg of sodium per serving, and “low-sodium” usually means 140 mg or less per serving. In contrast, regular table salt can contain as much as 560 mg of sodium in one serving.
Other en vogue salts, such as pink Himalayan salt, sea salt, and kosher salt, are high in sodium content – like regular table salt – but because of their larger crystal size, less sodium is delivered per serving.
Most salt substitutes are reduced in sodium, with the addition of potassium chloride instead.
FDA issues guidance on reducing salt
Currently, the U.S. sodium dietary guidelines for persons older than 14 stipulate 2,300 mg/d, which is equivalent to 1 teaspoon a day. However it is estimated that the average person in the United States consumes more than this – around 3,400 mg of sodium daily.
In October 2021, the U.S. Food and Drug Administration published guidance on voluntary sodium limitations in commercially processed, packaged, and prepared food. The FDA’s short-term approach is to slowly reduce exposure to sodium in processed and restaurant food by 2025, on the basis that people will eventually get used to less salt, as has happened in the United Kingdom and other countries.
Such strategies to reduce salt intake are now being used in national programs in several countries. Many of these successful initiatives include active engagement with the food industry to reduce the amount of sodium added to processed food, as well as public awareness campaigns to alert consumers to the dangers of eating too much salt. This includes increasing potassium in manufactured foods, primarily to target hypertension and heart disease, as described by Clare Farrand, MSc, BSc, and colleagues, in the Journal of Clinical Hypertension. The authors also make several recommendations regarding salt reduction policies:
- Food manufacturers should gradually reduce sodium in food to the lowest possible levels and explore the use of potassium-based sodium replacers to reduce sodium levels even further.
- Governments should continue to monitor sodium and potassium levels in processed foods.
- Further consideration may need to be given to how best to label salt substitutes (namely potassium) in processed foods to ensure that people who may be adversely affected are aware.
- Governments should systematically monitor potassium intake at the population level, including for specific susceptible groups.
- Governments should continue to systematically monitor sodium (salt) intake and iodine intake at the population level to adjust salt iodization over time as necessary, depending on observed salt intake in specific targeted groups, to ensure that they have sufficient but not excessive iodine intakes as salt intakes are reduced.
- Governments should consider opportunities for promoting and subsidizing salt substitutes, particularly in countries where salt added during cooking or at the table is the major source of salt in the diet.
The new FDA document includes 163 subcategories of foods in its voluntary salt reduction strategy.
Salt substitutes, high blood pressure, and mortality
Lowering sodium intake is almost certainly beneficial for persons with high blood pressure. In 2020, a review in Hypertension highlighted the benefit of salt substitutes in reducing hypertension, reporting that they lower systolic blood pressure by 5.58 mm Hg and diastolic blood pressure by 2.88 mm Hg.
And changes to dietary sodium intake can potentially reduce or obviate the need for medications for essential hypertension in some individuals. Although there are only a few studies on this topic, a study by Bruce Neal, MB, ChB, PhD, and colleagues, revealed a reduction in stroke, cardiovascular events, and deaths with the use of potassium-based salt substitutes.
Salt substitutes and sodium and potassium handling in the kidneys
Many studies have shown that potassium-rich salt substitutes are safe in individuals with normal kidney function, but are they safe and beneficial for people with chronic kidney disease (CKD)?
For anyone who is on a renal diet, potassium and sodium intake goals are limited according to their absolute level of kidney function.
There have been case reports of life-threatening blood potassium levels (hyperkalemia) due to potassium-rich salt substitutes in people with CKD, but no larger published studies on this topic can be found.
A diet modeling study by Rebecca Morrison and colleagues evaluated varying degrees of potassium-enriched salt substituted bread products and their impact on dietary intake in persons with CKD. They used dietary data from the National Nutrition and Physical Activity Survey 2011-2012 in Australia for 12,152 participants, 154 of whom had CKD. Replacing the sodium in bread with varying amounts of potassium chloride (20%, 30%, and 40%) would result in one-third of people with CKD exceeding the safe limits for dietary potassium consumption (31.8%, 32.6%, and 33%, respectively), they found.
“Potassium chloride substitution in staple foods such as bread and bread products have serious and potentially fatal consequences for people who need to restrict dietary potassium. Improved food labelling is required for consumers to avoid excessive consumption,” Ms. Morrison and colleagues concluded. They added that more studies are needed to further understand the risks of potassium dietary intake and hyperkalemia in CKD from potassium-based salt substitutes.
The American Heart Association recommends no more than 1,500 mg of sodium intake daily for persons with CKD, diabetes, or high blood pressure; those older than 51; and African American persons of any age.
The recommended daily intake of potassium in persons with CKD can range from 2,000 mg to 4,000 mg, depending on the individual and their degree of CKD. The potassium content in some salt substitutes varies from 440 mg to 2,800 mg per teaspoon.
The best recommendation for individuals with CKD and a goal to reduce their sodium intake is to use herbs and lower-sodium seasonings as a substitute, but these should always be reviewed with their physician and renal nutritionist.
Dr. Brookins is a board-certified nephrologist and internist practicing in Georgia. She is the founder and owner of Remote Renal Care, a telehealth kidney practice. She reported no relevant conflicts of interest.
A version of this article first appeared on Medscape.com.
Biomarkers predict cardiovascular risk in chronic kidney disease patients
Chronic kidney disease (CKD) patients may be at increased risk for atherosclerotic cardiovascular disease, but no ASCVD risk prediction models are currently in place to inform clinical care and prevention strategies, Joshua Bundy, PhD, of Tulane University, New Orleans, and colleagues wrote in their paper, published in the Journal of the American Society of Nephrology.
To improve the accuracy of ASCVD risk prediction, the researchers developed several models using data from the Chronic Renal Insufficiency Cohort (CRIC) study. This longitudinal cohort study included more than 2,500 adult CKD patients. The participants’ ages ranged from 21-74 years, with the mean age having been 55.8 years, and 52.0% of the cohort was male.
Kidney function was defined using the glomerular filtration rate; the mean estimated glomerular filtration rate (eGFR) of the study participants was 56.0 mL/min per 1.73m2. The primary endpoint for the prediction models was incident ASCVD, defined as a composite of incident fatal or nonfatal stroke or MI.
A total of 252 incident ASCVD events occurred during the first 10 years of follow-up from baseline (1.9 events per 1,000 person-years). Patients with ASCVD events were more likely to be older, Black, and current smokers. They also were more likely than those who did not experience ASCVD events to have less than a college level education, to have a history of diabetes, and to use blood pressure–lowering medications.
“In our study, we created two new prediction tools for patients with CKD: the first is a simple model that includes factors routinely measured by health care providers and the second is an expanded model with additional variables particularly important to patients with CKD, including measures of long-term blood sugar, inflammation, and kidney and heart injury,” he explained. “We found that the new models are better able to classify patients who will or will not have a stroke or heart attack within 10 years, compared with the standard models. The new tools may better assist health care providers and patients with CKD in shared decision-making for prevention of heart disease.”
Results
The area under the curve for a prediction model using coefficients estimated within the CRIC sample was 0.736. This represented an accuracy higher than the American College of Cardiology/American Heart Association Pooled Cohort Equations (PCE), which have shown an AUC of 0.730 (P = .03). The PCE were developed by the ACC and the AHA in 2013 to estimate ASCVD risk in the primary prevention population.
The second CRIC model that was developed using clinically available variables had an AUC of 0.760. However, the third CRIC biomarker-enriched model was even more effective, with an AUC of 0.771 – significantly higher than the clinical model (P = .001).
Model 1 included the ACC/AHA PCE variables with coefficients recalculated in the CRIC study sample. Model 2 (the CRIC Clinical Model) included age, HDL cholesterol, systolic BP, current smoking, urinary albumin-to-creatinine ratio (ACR), hemoglobin A1c, and hemoglobin. Model 3 (the CRIC Enriched Model) included age, total cholesterol, HDL cholesterol, current smoking, urinary ACR, A1c, apolipoprotein B, high-sensitivity C-reactive protein (hsCRP), troponin T, and N-terminal of the prohormone brain natriuretic peptide (NT-proBNP).
Both the clinical and biomarker models improved reclassification of non-ASCVD events, compared with the PCEs (6.6% and 10.0%, respectively).
Several factors not included in prior prediction models were important for atherosclerotic CVD prediction among patients with CKD, the researchers noted. These included variables routinely measured in clinical practice as well as biomarkers: measures of long-term glycemia (A1c), inflammation (hsCRP), kidney injury (urinary ACR), and cardiac injury (troponin T and NT-proBNP).
Patients who had an ASCVD event had higher levels of A1c, systolic and diastolic BP, urinary ACR, troponin T, and NT-proBNP; these patients also had lower levels of HDL cholesterol, eGFR, and hemoglobin, compared with those who did not have an event.
The study findings were limited by several factors including the selection of study participants based on a single assessment of kidney function, who had an above average baseline ASCVD risk, the researchers noted. Other limitations included the inability to include imaging variables in the models, and the overestimated risk in the highest predicted probability groups in the CRIC study.
However, the models significantly improve prediction beyond the ACC/AHA PCE in patients with CKD, they concluded.
Models may inform shared decision-making
The development of new prediction models is important, because cardiovascular disease is the leading cause of death among U.S. adults and preventing CVD is a major public health challenge, lead author Dr. Bundy said in an interview.
“In an effort to prevent CVD, risk prediction equations can help identify patients who are at high risk for developing CVD and who may benefit from initiation or intensification of preventive and/or therapeutic measures. Simultaneously, chronic kidney disease is prevalent and those with CKD are often considered at high risk for CVD,” he said.
“However, common risk prediction tools were developed for the general population and may not work as well in patients with CKD, who may have different risk factors. Improving risk prediction in patients with CKD may help identify those among this growing population who are truly at high risk, as well as identify those who are at low risk and less likely to benefit from invasive procedures,” Dr. Bundy explained.
Glomerular filtration rate was not a strong predictor of atherosclerotic CVD
“One of the surprising findings was that estimated glomerular filtration rate was not a strong predictor and was not included in our final models,” Dr. Bundy said.
“We know that eGFR is a very important measurement in this population, but our results suggest that, at least in our sample, urinary albumin-to-creatinine ratio and cardiac biomarkers like troponin T and NT-proBNP are stronger predictors of atherosclerotic CVD in a population with reduced kidney function,” he said.
“Patient characteristics like age, blood pressure, and cholesterol are used by health care providers to predict whether a person will have a heart attack or stroke. However, most currently available prediction tools were not made for use in patients with CKD, which is a condition that is becoming more common and is likely to be seen by more health care providers in family practice,” said Dr. Bundy. “These people with CKD may have different risk factors for heart disease.”
Models are useful for clinical practice
“We are seeing rising numbers of patients with CKD in the population because of increasing age, rising rates of diabetes, and hypertension,” Noel Deep, MD, said in an interview. “The current practice of medicine does not have CKD-specific prediction models for ASCVD development, and current risks are calculated based on prediction models developed for the general population.”
“Having a prediction model that incorporates criteria/variables associated with CKD improves our ability to accurately identify and address the risk of ASCVD in this particular patient population,” said Dr. Deep, who is a general internist in a multispecialty group practice with Aspirus Antigo (Wisc.) Clinic and the chief medical officer and a staff physician at Aspirus Langlade Hospital, also in Antigo.
“We always knew that CKD does place the individual at higher risk for developing ASCVD, but I was impressed by the significant improvement in the prediction models using CKD specific tools, such as cardiac biomarkers (NT-proBNP), intensity of diabetes control (A1c), tobacco use, urinary albuminuria, in addition to advancing age,” he said. “Many of the laboratory tests listed in this study are commonly available and can be easily incorporated into our evaluation for and management of ASCVD in our patients with CKD.”
“As a practicing primary care physician, I would say that this study emphasizes the importance of identifying and working toward mitigating the associated health risks that our patients with CKD might have coexisting and that significantly contribute to progression of CKD,” said Dr. Deep, who is also assistant clinical professor at the Medical College of Wisconsin, Wausau. “By addressing these risk factors, we can positively impact the health of our patients with CKD and decrease the morbidity and mortality, and health care costs. These predictive models can hopefully help us more accurately identify the risk of ASCVD thereby decreasing unnecessary diagnostic procedures and interventions which carry their own risks and morbidity.”
Looking ahead, “these predictive models should be assessed and validated in large studies in diverse populations and those with different risk factors for ASCVD because CKD can be caused by several different medical conditions each with potential to contribute to ASCVD,” Dr. Deep added.
Limitations and next steps
“Although we externally validated our models in two population-based cohort studies, the individuals in these datasets were selected based on only one assessment of kidney function,” Dr. Bundy noted. “Furthermore, the best practices for implementing risk prediction models in the clinic remain to be determined, especially as new models are developed.
“While our models show promising performance for predicting 10-year risk of atherosclerotic CVD, more clinical trials are needed to test implementation of these models for improving patient care and disease prevention.”
The study was supported by the National Institute of Diabetes and Digestive and Kidney Diseases. Additional support came from the University of Pennsylvania Clinical and Translational Science Award, Johns Hopkins University, the University of Maryland, Clinical and Translational Science Collaborative of Cleveland, the National Center for Advancing Translational Sciences component of the National Institutes of Health and NIH roadmap for Medical Research, Michigan Institute for Clinical and Health Research, University of Illinois at Chicago, Tulane COBRE for Clinical and Translational Research in Cardiometabolic Diseases, Kaiser Permanente, and the University of New Mexico. Lead author Dr. Bundy was supported by the National Institutes of Health/Eunice Kennedy Shriver National Institute of Child Health and Human Development. The researchers had no financial conflicts to disclose. Dr. Deep had no financial conflicts to disclose.
This article was updated on 2/17/2021.
Chronic kidney disease (CKD) patients may be at increased risk for atherosclerotic cardiovascular disease, but no ASCVD risk prediction models are currently in place to inform clinical care and prevention strategies, Joshua Bundy, PhD, of Tulane University, New Orleans, and colleagues wrote in their paper, published in the Journal of the American Society of Nephrology.
To improve the accuracy of ASCVD risk prediction, the researchers developed several models using data from the Chronic Renal Insufficiency Cohort (CRIC) study. This longitudinal cohort study included more than 2,500 adult CKD patients. The participants’ ages ranged from 21-74 years, with the mean age having been 55.8 years, and 52.0% of the cohort was male.
Kidney function was defined using the glomerular filtration rate; the mean estimated glomerular filtration rate (eGFR) of the study participants was 56.0 mL/min per 1.73m2. The primary endpoint for the prediction models was incident ASCVD, defined as a composite of incident fatal or nonfatal stroke or MI.
A total of 252 incident ASCVD events occurred during the first 10 years of follow-up from baseline (1.9 events per 1,000 person-years). Patients with ASCVD events were more likely to be older, Black, and current smokers. They also were more likely than those who did not experience ASCVD events to have less than a college level education, to have a history of diabetes, and to use blood pressure–lowering medications.
“In our study, we created two new prediction tools for patients with CKD: the first is a simple model that includes factors routinely measured by health care providers and the second is an expanded model with additional variables particularly important to patients with CKD, including measures of long-term blood sugar, inflammation, and kidney and heart injury,” he explained. “We found that the new models are better able to classify patients who will or will not have a stroke or heart attack within 10 years, compared with the standard models. The new tools may better assist health care providers and patients with CKD in shared decision-making for prevention of heart disease.”
Results
The area under the curve for a prediction model using coefficients estimated within the CRIC sample was 0.736. This represented an accuracy higher than the American College of Cardiology/American Heart Association Pooled Cohort Equations (PCE), which have shown an AUC of 0.730 (P = .03). The PCE were developed by the ACC and the AHA in 2013 to estimate ASCVD risk in the primary prevention population.
The second CRIC model that was developed using clinically available variables had an AUC of 0.760. However, the third CRIC biomarker-enriched model was even more effective, with an AUC of 0.771 – significantly higher than the clinical model (P = .001).
Model 1 included the ACC/AHA PCE variables with coefficients recalculated in the CRIC study sample. Model 2 (the CRIC Clinical Model) included age, HDL cholesterol, systolic BP, current smoking, urinary albumin-to-creatinine ratio (ACR), hemoglobin A1c, and hemoglobin. Model 3 (the CRIC Enriched Model) included age, total cholesterol, HDL cholesterol, current smoking, urinary ACR, A1c, apolipoprotein B, high-sensitivity C-reactive protein (hsCRP), troponin T, and N-terminal of the prohormone brain natriuretic peptide (NT-proBNP).
Both the clinical and biomarker models improved reclassification of non-ASCVD events, compared with the PCEs (6.6% and 10.0%, respectively).
Several factors not included in prior prediction models were important for atherosclerotic CVD prediction among patients with CKD, the researchers noted. These included variables routinely measured in clinical practice as well as biomarkers: measures of long-term glycemia (A1c), inflammation (hsCRP), kidney injury (urinary ACR), and cardiac injury (troponin T and NT-proBNP).
Patients who had an ASCVD event had higher levels of A1c, systolic and diastolic BP, urinary ACR, troponin T, and NT-proBNP; these patients also had lower levels of HDL cholesterol, eGFR, and hemoglobin, compared with those who did not have an event.
The study findings were limited by several factors including the selection of study participants based on a single assessment of kidney function, who had an above average baseline ASCVD risk, the researchers noted. Other limitations included the inability to include imaging variables in the models, and the overestimated risk in the highest predicted probability groups in the CRIC study.
However, the models significantly improve prediction beyond the ACC/AHA PCE in patients with CKD, they concluded.
Models may inform shared decision-making
The development of new prediction models is important, because cardiovascular disease is the leading cause of death among U.S. adults and preventing CVD is a major public health challenge, lead author Dr. Bundy said in an interview.
“In an effort to prevent CVD, risk prediction equations can help identify patients who are at high risk for developing CVD and who may benefit from initiation or intensification of preventive and/or therapeutic measures. Simultaneously, chronic kidney disease is prevalent and those with CKD are often considered at high risk for CVD,” he said.
“However, common risk prediction tools were developed for the general population and may not work as well in patients with CKD, who may have different risk factors. Improving risk prediction in patients with CKD may help identify those among this growing population who are truly at high risk, as well as identify those who are at low risk and less likely to benefit from invasive procedures,” Dr. Bundy explained.
Glomerular filtration rate was not a strong predictor of atherosclerotic CVD
“One of the surprising findings was that estimated glomerular filtration rate was not a strong predictor and was not included in our final models,” Dr. Bundy said.
“We know that eGFR is a very important measurement in this population, but our results suggest that, at least in our sample, urinary albumin-to-creatinine ratio and cardiac biomarkers like troponin T and NT-proBNP are stronger predictors of atherosclerotic CVD in a population with reduced kidney function,” he said.
“Patient characteristics like age, blood pressure, and cholesterol are used by health care providers to predict whether a person will have a heart attack or stroke. However, most currently available prediction tools were not made for use in patients with CKD, which is a condition that is becoming more common and is likely to be seen by more health care providers in family practice,” said Dr. Bundy. “These people with CKD may have different risk factors for heart disease.”
Models are useful for clinical practice
“We are seeing rising numbers of patients with CKD in the population because of increasing age, rising rates of diabetes, and hypertension,” Noel Deep, MD, said in an interview. “The current practice of medicine does not have CKD-specific prediction models for ASCVD development, and current risks are calculated based on prediction models developed for the general population.”
“Having a prediction model that incorporates criteria/variables associated with CKD improves our ability to accurately identify and address the risk of ASCVD in this particular patient population,” said Dr. Deep, who is a general internist in a multispecialty group practice with Aspirus Antigo (Wisc.) Clinic and the chief medical officer and a staff physician at Aspirus Langlade Hospital, also in Antigo.
“We always knew that CKD does place the individual at higher risk for developing ASCVD, but I was impressed by the significant improvement in the prediction models using CKD specific tools, such as cardiac biomarkers (NT-proBNP), intensity of diabetes control (A1c), tobacco use, urinary albuminuria, in addition to advancing age,” he said. “Many of the laboratory tests listed in this study are commonly available and can be easily incorporated into our evaluation for and management of ASCVD in our patients with CKD.”
“As a practicing primary care physician, I would say that this study emphasizes the importance of identifying and working toward mitigating the associated health risks that our patients with CKD might have coexisting and that significantly contribute to progression of CKD,” said Dr. Deep, who is also assistant clinical professor at the Medical College of Wisconsin, Wausau. “By addressing these risk factors, we can positively impact the health of our patients with CKD and decrease the morbidity and mortality, and health care costs. These predictive models can hopefully help us more accurately identify the risk of ASCVD thereby decreasing unnecessary diagnostic procedures and interventions which carry their own risks and morbidity.”
Looking ahead, “these predictive models should be assessed and validated in large studies in diverse populations and those with different risk factors for ASCVD because CKD can be caused by several different medical conditions each with potential to contribute to ASCVD,” Dr. Deep added.
Limitations and next steps
“Although we externally validated our models in two population-based cohort studies, the individuals in these datasets were selected based on only one assessment of kidney function,” Dr. Bundy noted. “Furthermore, the best practices for implementing risk prediction models in the clinic remain to be determined, especially as new models are developed.
“While our models show promising performance for predicting 10-year risk of atherosclerotic CVD, more clinical trials are needed to test implementation of these models for improving patient care and disease prevention.”
The study was supported by the National Institute of Diabetes and Digestive and Kidney Diseases. Additional support came from the University of Pennsylvania Clinical and Translational Science Award, Johns Hopkins University, the University of Maryland, Clinical and Translational Science Collaborative of Cleveland, the National Center for Advancing Translational Sciences component of the National Institutes of Health and NIH roadmap for Medical Research, Michigan Institute for Clinical and Health Research, University of Illinois at Chicago, Tulane COBRE for Clinical and Translational Research in Cardiometabolic Diseases, Kaiser Permanente, and the University of New Mexico. Lead author Dr. Bundy was supported by the National Institutes of Health/Eunice Kennedy Shriver National Institute of Child Health and Human Development. The researchers had no financial conflicts to disclose. Dr. Deep had no financial conflicts to disclose.
This article was updated on 2/17/2021.
Chronic kidney disease (CKD) patients may be at increased risk for atherosclerotic cardiovascular disease, but no ASCVD risk prediction models are currently in place to inform clinical care and prevention strategies, Joshua Bundy, PhD, of Tulane University, New Orleans, and colleagues wrote in their paper, published in the Journal of the American Society of Nephrology.
To improve the accuracy of ASCVD risk prediction, the researchers developed several models using data from the Chronic Renal Insufficiency Cohort (CRIC) study. This longitudinal cohort study included more than 2,500 adult CKD patients. The participants’ ages ranged from 21-74 years, with the mean age having been 55.8 years, and 52.0% of the cohort was male.
Kidney function was defined using the glomerular filtration rate; the mean estimated glomerular filtration rate (eGFR) of the study participants was 56.0 mL/min per 1.73m2. The primary endpoint for the prediction models was incident ASCVD, defined as a composite of incident fatal or nonfatal stroke or MI.
A total of 252 incident ASCVD events occurred during the first 10 years of follow-up from baseline (1.9 events per 1,000 person-years). Patients with ASCVD events were more likely to be older, Black, and current smokers. They also were more likely than those who did not experience ASCVD events to have less than a college level education, to have a history of diabetes, and to use blood pressure–lowering medications.
“In our study, we created two new prediction tools for patients with CKD: the first is a simple model that includes factors routinely measured by health care providers and the second is an expanded model with additional variables particularly important to patients with CKD, including measures of long-term blood sugar, inflammation, and kidney and heart injury,” he explained. “We found that the new models are better able to classify patients who will or will not have a stroke or heart attack within 10 years, compared with the standard models. The new tools may better assist health care providers and patients with CKD in shared decision-making for prevention of heart disease.”
Results
The area under the curve for a prediction model using coefficients estimated within the CRIC sample was 0.736. This represented an accuracy higher than the American College of Cardiology/American Heart Association Pooled Cohort Equations (PCE), which have shown an AUC of 0.730 (P = .03). The PCE were developed by the ACC and the AHA in 2013 to estimate ASCVD risk in the primary prevention population.
The second CRIC model that was developed using clinically available variables had an AUC of 0.760. However, the third CRIC biomarker-enriched model was even more effective, with an AUC of 0.771 – significantly higher than the clinical model (P = .001).
Model 1 included the ACC/AHA PCE variables with coefficients recalculated in the CRIC study sample. Model 2 (the CRIC Clinical Model) included age, HDL cholesterol, systolic BP, current smoking, urinary albumin-to-creatinine ratio (ACR), hemoglobin A1c, and hemoglobin. Model 3 (the CRIC Enriched Model) included age, total cholesterol, HDL cholesterol, current smoking, urinary ACR, A1c, apolipoprotein B, high-sensitivity C-reactive protein (hsCRP), troponin T, and N-terminal of the prohormone brain natriuretic peptide (NT-proBNP).
Both the clinical and biomarker models improved reclassification of non-ASCVD events, compared with the PCEs (6.6% and 10.0%, respectively).
Several factors not included in prior prediction models were important for atherosclerotic CVD prediction among patients with CKD, the researchers noted. These included variables routinely measured in clinical practice as well as biomarkers: measures of long-term glycemia (A1c), inflammation (hsCRP), kidney injury (urinary ACR), and cardiac injury (troponin T and NT-proBNP).
Patients who had an ASCVD event had higher levels of A1c, systolic and diastolic BP, urinary ACR, troponin T, and NT-proBNP; these patients also had lower levels of HDL cholesterol, eGFR, and hemoglobin, compared with those who did not have an event.
The study findings were limited by several factors including the selection of study participants based on a single assessment of kidney function, who had an above average baseline ASCVD risk, the researchers noted. Other limitations included the inability to include imaging variables in the models, and the overestimated risk in the highest predicted probability groups in the CRIC study.
However, the models significantly improve prediction beyond the ACC/AHA PCE in patients with CKD, they concluded.
Models may inform shared decision-making
The development of new prediction models is important, because cardiovascular disease is the leading cause of death among U.S. adults and preventing CVD is a major public health challenge, lead author Dr. Bundy said in an interview.
“In an effort to prevent CVD, risk prediction equations can help identify patients who are at high risk for developing CVD and who may benefit from initiation or intensification of preventive and/or therapeutic measures. Simultaneously, chronic kidney disease is prevalent and those with CKD are often considered at high risk for CVD,” he said.
“However, common risk prediction tools were developed for the general population and may not work as well in patients with CKD, who may have different risk factors. Improving risk prediction in patients with CKD may help identify those among this growing population who are truly at high risk, as well as identify those who are at low risk and less likely to benefit from invasive procedures,” Dr. Bundy explained.
Glomerular filtration rate was not a strong predictor of atherosclerotic CVD
“One of the surprising findings was that estimated glomerular filtration rate was not a strong predictor and was not included in our final models,” Dr. Bundy said.
“We know that eGFR is a very important measurement in this population, but our results suggest that, at least in our sample, urinary albumin-to-creatinine ratio and cardiac biomarkers like troponin T and NT-proBNP are stronger predictors of atherosclerotic CVD in a population with reduced kidney function,” he said.
“Patient characteristics like age, blood pressure, and cholesterol are used by health care providers to predict whether a person will have a heart attack or stroke. However, most currently available prediction tools were not made for use in patients with CKD, which is a condition that is becoming more common and is likely to be seen by more health care providers in family practice,” said Dr. Bundy. “These people with CKD may have different risk factors for heart disease.”
Models are useful for clinical practice
“We are seeing rising numbers of patients with CKD in the population because of increasing age, rising rates of diabetes, and hypertension,” Noel Deep, MD, said in an interview. “The current practice of medicine does not have CKD-specific prediction models for ASCVD development, and current risks are calculated based on prediction models developed for the general population.”
“Having a prediction model that incorporates criteria/variables associated with CKD improves our ability to accurately identify and address the risk of ASCVD in this particular patient population,” said Dr. Deep, who is a general internist in a multispecialty group practice with Aspirus Antigo (Wisc.) Clinic and the chief medical officer and a staff physician at Aspirus Langlade Hospital, also in Antigo.
“We always knew that CKD does place the individual at higher risk for developing ASCVD, but I was impressed by the significant improvement in the prediction models using CKD specific tools, such as cardiac biomarkers (NT-proBNP), intensity of diabetes control (A1c), tobacco use, urinary albuminuria, in addition to advancing age,” he said. “Many of the laboratory tests listed in this study are commonly available and can be easily incorporated into our evaluation for and management of ASCVD in our patients with CKD.”
“As a practicing primary care physician, I would say that this study emphasizes the importance of identifying and working toward mitigating the associated health risks that our patients with CKD might have coexisting and that significantly contribute to progression of CKD,” said Dr. Deep, who is also assistant clinical professor at the Medical College of Wisconsin, Wausau. “By addressing these risk factors, we can positively impact the health of our patients with CKD and decrease the morbidity and mortality, and health care costs. These predictive models can hopefully help us more accurately identify the risk of ASCVD thereby decreasing unnecessary diagnostic procedures and interventions which carry their own risks and morbidity.”
Looking ahead, “these predictive models should be assessed and validated in large studies in diverse populations and those with different risk factors for ASCVD because CKD can be caused by several different medical conditions each with potential to contribute to ASCVD,” Dr. Deep added.
Limitations and next steps
“Although we externally validated our models in two population-based cohort studies, the individuals in these datasets were selected based on only one assessment of kidney function,” Dr. Bundy noted. “Furthermore, the best practices for implementing risk prediction models in the clinic remain to be determined, especially as new models are developed.
“While our models show promising performance for predicting 10-year risk of atherosclerotic CVD, more clinical trials are needed to test implementation of these models for improving patient care and disease prevention.”
The study was supported by the National Institute of Diabetes and Digestive and Kidney Diseases. Additional support came from the University of Pennsylvania Clinical and Translational Science Award, Johns Hopkins University, the University of Maryland, Clinical and Translational Science Collaborative of Cleveland, the National Center for Advancing Translational Sciences component of the National Institutes of Health and NIH roadmap for Medical Research, Michigan Institute for Clinical and Health Research, University of Illinois at Chicago, Tulane COBRE for Clinical and Translational Research in Cardiometabolic Diseases, Kaiser Permanente, and the University of New Mexico. Lead author Dr. Bundy was supported by the National Institutes of Health/Eunice Kennedy Shriver National Institute of Child Health and Human Development. The researchers had no financial conflicts to disclose. Dr. Deep had no financial conflicts to disclose.
This article was updated on 2/17/2021.
FROM THE JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY
No COVID vax, no transplant: Unfair or good medicine?
Right now, more than 106,600 people in the United States are on the national transplant waiting list, each hoping to hear soon that a lung, kidney, heart, or other vital organ has been found for them. It’s the promise not just of a new organ, but a new life.
Well before they are placed on that list, transplant candidates, as they’re known, are evaluated with a battery of tests and exams to be sure they are infection free, their other organs are healthy, and that all their vaccinations are up to date.
In January, a 31-year-old Boston father of two declined to get the COVID-19 vaccine, and Brigham and Women’s Hospital officials removed him from the heart transplant waiting list. And in North Carolina, a 38-year-old man in need of a kidney transplant said he, too, was denied the organ when he declined to get the vaccination.
Those are just two of the most recent cases. The decisions by the transplant centers to remove the candidates from the waiting list have set off a national debate among ethicists, family members, doctors, patients, and others.
On social media and in conversation, the question persists: Is removing them from the list unfair and cruel, or simply business as usual to keep the patient as healthy as possible and the transplant as successful as possible?
Two recent tweets sum up the debate.
“The people responsible for this should be charged with attempted homicide,” one Twitter user said, while another suggested that the more accurate way to headline the news about a transplant candidate refusing the COVID-19 vaccine would be: “Patient voluntarily forfeits donor organ.”
Doctors and ethics experts, as well as other patients on the waiting list, say it’s simply good medicine to require the COVID vaccine, along with a host of other pretransplant requirements.
Transplant protocols
“Transplant medicine has always been a strong promoter of vaccination,” said Silas Prescod Norman, MD, a clinical associate professor of nephrology and internal medicine at the University of Michigan, Ann Arbor. He is a kidney specialist who works in the university’s transplant clinic.
Requiring the COVID vaccine is in line with requirements to get numerous other vaccines, he said.“Promoting the COVID vaccine among our transplant candidates and recipients is just an extension of our usual practice.
“In transplantation, first and foremost is patient safety,” Dr. Norman said. “And we know that solid organ transplant patients are at substantially higher risk of contracting COVID than nontransplant patients.”
After the transplant, they are placed on immunosuppressant drugs, that weaken the immune system while also decreasing the body’s ability to reject the new organ.
“We know now, because there is good data about the vaccine to show that people who are on transplant medications are less likely to make detectable antibodies after vaccination,” said Dr. Norman, who’s also a medical adviser for the American Kidney Fund, a nonprofit that provides kidney health information and financial assistance for dialysis.
And this is not a surprise because of the immunosuppressive effects, he said. “So it only makes sense to get people vaccinated before transplantation.”
Researchers compared the cases of more than 17,000 people who had received organ transplants and were hospitalized from April to November 2020, either for COVID (1,682 of them) or other health issues. Those who had COVID were more likely to have complications and to die in the hospital than those who did not have it.
Vaccination guidelines, policies
Federal COVID-19 treatment guidelines from the National Institutes of Health state that transplant patients on immunosuppressant drugs used after the procedure should be considered at a higher risk of getting severe COVID if infected.
In a joint statement from the American Society of Transplant Surgeons, the American Society of Transplantation, and the International Society for Heart and Lung Transplantation, the organizations say they “strongly recommend that all eligible children and adult transplant candidates and recipients be vaccinated with a COVID-19 vaccine [and booster] that is approved or authorized in their jurisdiction. Whenever possible, vaccination should occur prior to transplantation.” Ideally, it should be completed at least 2 weeks before the transplant.
The organizations also “support the development of institutional policies regarding pretransplant vaccination. We believe that this is in the best interest of the transplant candidate, optimizing their chances of getting through the perioperative and posttransplant periods without severe COVID-19 disease, especially at times of greater infection prevalence.”
Officials at Brigham and Women’s Hospital, where the 31-year-old father was removed from the list, issued a statement that reads, in part: “Our Mass General Brigham health care system requires several [Centers for Disease Control and Prevention]-recommended vaccines, including the COVID-19 vaccine, and lifestyle behaviors for transplant candidates to create both the best chance for a successful operation and to optimize the patient’s survival after transplantation, given that their immune system is drastically suppressed. Patients are not active on the wait list without this.”
Ethics amid organ shortage
“Organs are scarce,” said Arthur L. Caplan, PhD, director of the division of medical ethics at New York University Langone Medical Center. That makes the goal of choosing the very best candidates for success even more crucial.
“You try to maximize the chance the organ will work,” he said. Pretransplant vaccination is one way.
The shortage is most severe for kidney transplants. In 2020, according to federal statistics, more than 91,000 kidney transplants were needed, but fewer than 23,000 were received. During 2021, 41,354 transplants were done, an increase of nearly 6% over the previous year. The total includes kidneys, hearts, lungs, and other organs, with kidneys accounting for more than 24,000 of the total.
Even with the rise in transplant numbers, supply does not meet demand. According to federal statistics, 17 people in the United States die each day waiting for an organ transplant. Every 9 minutes, someone is added to the waiting list.
“This isn’t and it shouldn’t be a fight about the COVID vaccine,” Dr. Caplan said. “This isn’t an issue about punishing non-COVID vaccinators. It’s deciding who is going to get a scarce organ.”
“A lot of people [opposed to removing the nonvaccinated from the list] think: ‘Oh, they are just killing those people who won’t take a COVID vaccine.’ That’s not what is going on.”
The transplant candidate must be in the best possible shape overall, Dr. Caplan and doctors agreed. Someone who is smoking, drinking heavily, or abusing drugs isn’t going to the top of the list either. And for other procedures, such as bariatric surgery or knee surgery, some patients are told first to lose weight before a surgeon will operate.
The worry about side effects from the vaccine, which some patients have cited as a concern, is misplaced, Dr. Caplan said. What transplant candidates who refuse the COVID vaccine may not be thinking about is that they are facing a serious operation and will be on numerous anti-rejection drugs, with side effects, after the surgery.
“So to be worried about the side effects of a COVID vaccine is irrational,” he said.
Transplants: The process
The patients who were recently removed from the transplant list could seek care and a transplant at an alternate center, said Anne Paschke, a spokesperson for the United Network for Organ Sharing, a nonprofit group that is under contract with the federal government and operates the national Organ Procurement and Transplantation Network (OPTN).
“Transplant hospitals decide which patients to add to the wait list based on their own criteria and medical judgment to create the best chance for a positive transplant outcome,” she said. That’s done with the understanding that patients will help with their medical care.
So, if one program won’t accept a patient, another may. But, if a patient turned down at one center due to refusing to get the COVID vaccine tries another center, the requirements at that hospital may be the same, she said.
OPTN maintains a list of transplant centers. As of Jan. 28, there were 251 transplant centers, according to UNOS, which manages the waiting list, matches donors and recipients, and strives for equity, among other duties.
Pretransplant refusers not typical
“The cases we are seeing are outliers,” Dr. Caplan said of the handful of known candidates who have refused the vaccine. Most ask their doctor exactly what they need to do to live and follow those instructions.
Dr. Norman agreed. Most of the kidney patients he cares for who are hoping for a transplant have been on dialysis, “which they do not like. They are doing whatever they can to make sure they don’t go back on dialysis. As a group, they tend to be very adherent, very safety conscious because they understand their risk and they understand the gift they have received [or will receive] through transplantation. They want to do everything they can to respect and protect that gift.”
Not surprisingly, some on the transplant list who are vaccinated have strong opinions about those who refuse to get the vaccine. Dana J. Ufkes, 61, a Seattle realtor, has been on the kidney transplant list – this time – since 2003, hoping for her third transplant. When asked if potential recipients should be removed from the list if they refuse the COVID vaccine, her answer was immediate: “Absolutely.”
At age 17, Ms. Ufkes got a serious kidney infection that went undiagnosed and untreated. Her kidney health worsened, and she needed a transplant. She got her first one in 1986, then again in 1992.
“They last longer than they used to,” she said. But not forever. (According to the American Kidney Fund, transplants from a living kidney donor last about 15-20 years; from a deceased donor, 10-15.)
The decision to decline the vaccine is, of course, each person’s choice, Ms. Ufkes said. But “if they don’t want to be vaccinated [and still want to be on the list], I think that’s BS.”
Citing the lack of organs, “it’s not like they are handing these out like jellybeans.”
A version of this article first appeared on WebMD.com.
Right now, more than 106,600 people in the United States are on the national transplant waiting list, each hoping to hear soon that a lung, kidney, heart, or other vital organ has been found for them. It’s the promise not just of a new organ, but a new life.
Well before they are placed on that list, transplant candidates, as they’re known, are evaluated with a battery of tests and exams to be sure they are infection free, their other organs are healthy, and that all their vaccinations are up to date.
In January, a 31-year-old Boston father of two declined to get the COVID-19 vaccine, and Brigham and Women’s Hospital officials removed him from the heart transplant waiting list. And in North Carolina, a 38-year-old man in need of a kidney transplant said he, too, was denied the organ when he declined to get the vaccination.
Those are just two of the most recent cases. The decisions by the transplant centers to remove the candidates from the waiting list have set off a national debate among ethicists, family members, doctors, patients, and others.
On social media and in conversation, the question persists: Is removing them from the list unfair and cruel, or simply business as usual to keep the patient as healthy as possible and the transplant as successful as possible?
Two recent tweets sum up the debate.
“The people responsible for this should be charged with attempted homicide,” one Twitter user said, while another suggested that the more accurate way to headline the news about a transplant candidate refusing the COVID-19 vaccine would be: “Patient voluntarily forfeits donor organ.”
Doctors and ethics experts, as well as other patients on the waiting list, say it’s simply good medicine to require the COVID vaccine, along with a host of other pretransplant requirements.
Transplant protocols
“Transplant medicine has always been a strong promoter of vaccination,” said Silas Prescod Norman, MD, a clinical associate professor of nephrology and internal medicine at the University of Michigan, Ann Arbor. He is a kidney specialist who works in the university’s transplant clinic.
Requiring the COVID vaccine is in line with requirements to get numerous other vaccines, he said.“Promoting the COVID vaccine among our transplant candidates and recipients is just an extension of our usual practice.
“In transplantation, first and foremost is patient safety,” Dr. Norman said. “And we know that solid organ transplant patients are at substantially higher risk of contracting COVID than nontransplant patients.”
After the transplant, they are placed on immunosuppressant drugs, that weaken the immune system while also decreasing the body’s ability to reject the new organ.
“We know now, because there is good data about the vaccine to show that people who are on transplant medications are less likely to make detectable antibodies after vaccination,” said Dr. Norman, who’s also a medical adviser for the American Kidney Fund, a nonprofit that provides kidney health information and financial assistance for dialysis.
And this is not a surprise because of the immunosuppressive effects, he said. “So it only makes sense to get people vaccinated before transplantation.”
Researchers compared the cases of more than 17,000 people who had received organ transplants and were hospitalized from April to November 2020, either for COVID (1,682 of them) or other health issues. Those who had COVID were more likely to have complications and to die in the hospital than those who did not have it.
Vaccination guidelines, policies
Federal COVID-19 treatment guidelines from the National Institutes of Health state that transplant patients on immunosuppressant drugs used after the procedure should be considered at a higher risk of getting severe COVID if infected.
In a joint statement from the American Society of Transplant Surgeons, the American Society of Transplantation, and the International Society for Heart and Lung Transplantation, the organizations say they “strongly recommend that all eligible children and adult transplant candidates and recipients be vaccinated with a COVID-19 vaccine [and booster] that is approved or authorized in their jurisdiction. Whenever possible, vaccination should occur prior to transplantation.” Ideally, it should be completed at least 2 weeks before the transplant.
The organizations also “support the development of institutional policies regarding pretransplant vaccination. We believe that this is in the best interest of the transplant candidate, optimizing their chances of getting through the perioperative and posttransplant periods without severe COVID-19 disease, especially at times of greater infection prevalence.”
Officials at Brigham and Women’s Hospital, where the 31-year-old father was removed from the list, issued a statement that reads, in part: “Our Mass General Brigham health care system requires several [Centers for Disease Control and Prevention]-recommended vaccines, including the COVID-19 vaccine, and lifestyle behaviors for transplant candidates to create both the best chance for a successful operation and to optimize the patient’s survival after transplantation, given that their immune system is drastically suppressed. Patients are not active on the wait list without this.”
Ethics amid organ shortage
“Organs are scarce,” said Arthur L. Caplan, PhD, director of the division of medical ethics at New York University Langone Medical Center. That makes the goal of choosing the very best candidates for success even more crucial.
“You try to maximize the chance the organ will work,” he said. Pretransplant vaccination is one way.
The shortage is most severe for kidney transplants. In 2020, according to federal statistics, more than 91,000 kidney transplants were needed, but fewer than 23,000 were received. During 2021, 41,354 transplants were done, an increase of nearly 6% over the previous year. The total includes kidneys, hearts, lungs, and other organs, with kidneys accounting for more than 24,000 of the total.
Even with the rise in transplant numbers, supply does not meet demand. According to federal statistics, 17 people in the United States die each day waiting for an organ transplant. Every 9 minutes, someone is added to the waiting list.
“This isn’t and it shouldn’t be a fight about the COVID vaccine,” Dr. Caplan said. “This isn’t an issue about punishing non-COVID vaccinators. It’s deciding who is going to get a scarce organ.”
“A lot of people [opposed to removing the nonvaccinated from the list] think: ‘Oh, they are just killing those people who won’t take a COVID vaccine.’ That’s not what is going on.”
The transplant candidate must be in the best possible shape overall, Dr. Caplan and doctors agreed. Someone who is smoking, drinking heavily, or abusing drugs isn’t going to the top of the list either. And for other procedures, such as bariatric surgery or knee surgery, some patients are told first to lose weight before a surgeon will operate.
The worry about side effects from the vaccine, which some patients have cited as a concern, is misplaced, Dr. Caplan said. What transplant candidates who refuse the COVID vaccine may not be thinking about is that they are facing a serious operation and will be on numerous anti-rejection drugs, with side effects, after the surgery.
“So to be worried about the side effects of a COVID vaccine is irrational,” he said.
Transplants: The process
The patients who were recently removed from the transplant list could seek care and a transplant at an alternate center, said Anne Paschke, a spokesperson for the United Network for Organ Sharing, a nonprofit group that is under contract with the federal government and operates the national Organ Procurement and Transplantation Network (OPTN).
“Transplant hospitals decide which patients to add to the wait list based on their own criteria and medical judgment to create the best chance for a positive transplant outcome,” she said. That’s done with the understanding that patients will help with their medical care.
So, if one program won’t accept a patient, another may. But, if a patient turned down at one center due to refusing to get the COVID vaccine tries another center, the requirements at that hospital may be the same, she said.
OPTN maintains a list of transplant centers. As of Jan. 28, there were 251 transplant centers, according to UNOS, which manages the waiting list, matches donors and recipients, and strives for equity, among other duties.
Pretransplant refusers not typical
“The cases we are seeing are outliers,” Dr. Caplan said of the handful of known candidates who have refused the vaccine. Most ask their doctor exactly what they need to do to live and follow those instructions.
Dr. Norman agreed. Most of the kidney patients he cares for who are hoping for a transplant have been on dialysis, “which they do not like. They are doing whatever they can to make sure they don’t go back on dialysis. As a group, they tend to be very adherent, very safety conscious because they understand their risk and they understand the gift they have received [or will receive] through transplantation. They want to do everything they can to respect and protect that gift.”
Not surprisingly, some on the transplant list who are vaccinated have strong opinions about those who refuse to get the vaccine. Dana J. Ufkes, 61, a Seattle realtor, has been on the kidney transplant list – this time – since 2003, hoping for her third transplant. When asked if potential recipients should be removed from the list if they refuse the COVID vaccine, her answer was immediate: “Absolutely.”
At age 17, Ms. Ufkes got a serious kidney infection that went undiagnosed and untreated. Her kidney health worsened, and she needed a transplant. She got her first one in 1986, then again in 1992.
“They last longer than they used to,” she said. But not forever. (According to the American Kidney Fund, transplants from a living kidney donor last about 15-20 years; from a deceased donor, 10-15.)
The decision to decline the vaccine is, of course, each person’s choice, Ms. Ufkes said. But “if they don’t want to be vaccinated [and still want to be on the list], I think that’s BS.”
Citing the lack of organs, “it’s not like they are handing these out like jellybeans.”
A version of this article first appeared on WebMD.com.
Right now, more than 106,600 people in the United States are on the national transplant waiting list, each hoping to hear soon that a lung, kidney, heart, or other vital organ has been found for them. It’s the promise not just of a new organ, but a new life.
Well before they are placed on that list, transplant candidates, as they’re known, are evaluated with a battery of tests and exams to be sure they are infection free, their other organs are healthy, and that all their vaccinations are up to date.
In January, a 31-year-old Boston father of two declined to get the COVID-19 vaccine, and Brigham and Women’s Hospital officials removed him from the heart transplant waiting list. And in North Carolina, a 38-year-old man in need of a kidney transplant said he, too, was denied the organ when he declined to get the vaccination.
Those are just two of the most recent cases. The decisions by the transplant centers to remove the candidates from the waiting list have set off a national debate among ethicists, family members, doctors, patients, and others.
On social media and in conversation, the question persists: Is removing them from the list unfair and cruel, or simply business as usual to keep the patient as healthy as possible and the transplant as successful as possible?
Two recent tweets sum up the debate.
“The people responsible for this should be charged with attempted homicide,” one Twitter user said, while another suggested that the more accurate way to headline the news about a transplant candidate refusing the COVID-19 vaccine would be: “Patient voluntarily forfeits donor organ.”
Doctors and ethics experts, as well as other patients on the waiting list, say it’s simply good medicine to require the COVID vaccine, along with a host of other pretransplant requirements.
Transplant protocols
“Transplant medicine has always been a strong promoter of vaccination,” said Silas Prescod Norman, MD, a clinical associate professor of nephrology and internal medicine at the University of Michigan, Ann Arbor. He is a kidney specialist who works in the university’s transplant clinic.
Requiring the COVID vaccine is in line with requirements to get numerous other vaccines, he said.“Promoting the COVID vaccine among our transplant candidates and recipients is just an extension of our usual practice.
“In transplantation, first and foremost is patient safety,” Dr. Norman said. “And we know that solid organ transplant patients are at substantially higher risk of contracting COVID than nontransplant patients.”
After the transplant, they are placed on immunosuppressant drugs, that weaken the immune system while also decreasing the body’s ability to reject the new organ.
“We know now, because there is good data about the vaccine to show that people who are on transplant medications are less likely to make detectable antibodies after vaccination,” said Dr. Norman, who’s also a medical adviser for the American Kidney Fund, a nonprofit that provides kidney health information and financial assistance for dialysis.
And this is not a surprise because of the immunosuppressive effects, he said. “So it only makes sense to get people vaccinated before transplantation.”
Researchers compared the cases of more than 17,000 people who had received organ transplants and were hospitalized from April to November 2020, either for COVID (1,682 of them) or other health issues. Those who had COVID were more likely to have complications and to die in the hospital than those who did not have it.
Vaccination guidelines, policies
Federal COVID-19 treatment guidelines from the National Institutes of Health state that transplant patients on immunosuppressant drugs used after the procedure should be considered at a higher risk of getting severe COVID if infected.
In a joint statement from the American Society of Transplant Surgeons, the American Society of Transplantation, and the International Society for Heart and Lung Transplantation, the organizations say they “strongly recommend that all eligible children and adult transplant candidates and recipients be vaccinated with a COVID-19 vaccine [and booster] that is approved or authorized in their jurisdiction. Whenever possible, vaccination should occur prior to transplantation.” Ideally, it should be completed at least 2 weeks before the transplant.
The organizations also “support the development of institutional policies regarding pretransplant vaccination. We believe that this is in the best interest of the transplant candidate, optimizing their chances of getting through the perioperative and posttransplant periods without severe COVID-19 disease, especially at times of greater infection prevalence.”
Officials at Brigham and Women’s Hospital, where the 31-year-old father was removed from the list, issued a statement that reads, in part: “Our Mass General Brigham health care system requires several [Centers for Disease Control and Prevention]-recommended vaccines, including the COVID-19 vaccine, and lifestyle behaviors for transplant candidates to create both the best chance for a successful operation and to optimize the patient’s survival after transplantation, given that their immune system is drastically suppressed. Patients are not active on the wait list without this.”
Ethics amid organ shortage
“Organs are scarce,” said Arthur L. Caplan, PhD, director of the division of medical ethics at New York University Langone Medical Center. That makes the goal of choosing the very best candidates for success even more crucial.
“You try to maximize the chance the organ will work,” he said. Pretransplant vaccination is one way.
The shortage is most severe for kidney transplants. In 2020, according to federal statistics, more than 91,000 kidney transplants were needed, but fewer than 23,000 were received. During 2021, 41,354 transplants were done, an increase of nearly 6% over the previous year. The total includes kidneys, hearts, lungs, and other organs, with kidneys accounting for more than 24,000 of the total.
Even with the rise in transplant numbers, supply does not meet demand. According to federal statistics, 17 people in the United States die each day waiting for an organ transplant. Every 9 minutes, someone is added to the waiting list.
“This isn’t and it shouldn’t be a fight about the COVID vaccine,” Dr. Caplan said. “This isn’t an issue about punishing non-COVID vaccinators. It’s deciding who is going to get a scarce organ.”
“A lot of people [opposed to removing the nonvaccinated from the list] think: ‘Oh, they are just killing those people who won’t take a COVID vaccine.’ That’s not what is going on.”
The transplant candidate must be in the best possible shape overall, Dr. Caplan and doctors agreed. Someone who is smoking, drinking heavily, or abusing drugs isn’t going to the top of the list either. And for other procedures, such as bariatric surgery or knee surgery, some patients are told first to lose weight before a surgeon will operate.
The worry about side effects from the vaccine, which some patients have cited as a concern, is misplaced, Dr. Caplan said. What transplant candidates who refuse the COVID vaccine may not be thinking about is that they are facing a serious operation and will be on numerous anti-rejection drugs, with side effects, after the surgery.
“So to be worried about the side effects of a COVID vaccine is irrational,” he said.
Transplants: The process
The patients who were recently removed from the transplant list could seek care and a transplant at an alternate center, said Anne Paschke, a spokesperson for the United Network for Organ Sharing, a nonprofit group that is under contract with the federal government and operates the national Organ Procurement and Transplantation Network (OPTN).
“Transplant hospitals decide which patients to add to the wait list based on their own criteria and medical judgment to create the best chance for a positive transplant outcome,” she said. That’s done with the understanding that patients will help with their medical care.
So, if one program won’t accept a patient, another may. But, if a patient turned down at one center due to refusing to get the COVID vaccine tries another center, the requirements at that hospital may be the same, she said.
OPTN maintains a list of transplant centers. As of Jan. 28, there were 251 transplant centers, according to UNOS, which manages the waiting list, matches donors and recipients, and strives for equity, among other duties.
Pretransplant refusers not typical
“The cases we are seeing are outliers,” Dr. Caplan said of the handful of known candidates who have refused the vaccine. Most ask their doctor exactly what they need to do to live and follow those instructions.
Dr. Norman agreed. Most of the kidney patients he cares for who are hoping for a transplant have been on dialysis, “which they do not like. They are doing whatever they can to make sure they don’t go back on dialysis. As a group, they tend to be very adherent, very safety conscious because they understand their risk and they understand the gift they have received [or will receive] through transplantation. They want to do everything they can to respect and protect that gift.”
Not surprisingly, some on the transplant list who are vaccinated have strong opinions about those who refuse to get the vaccine. Dana J. Ufkes, 61, a Seattle realtor, has been on the kidney transplant list – this time – since 2003, hoping for her third transplant. When asked if potential recipients should be removed from the list if they refuse the COVID vaccine, her answer was immediate: “Absolutely.”
At age 17, Ms. Ufkes got a serious kidney infection that went undiagnosed and untreated. Her kidney health worsened, and she needed a transplant. She got her first one in 1986, then again in 1992.
“They last longer than they used to,” she said. But not forever. (According to the American Kidney Fund, transplants from a living kidney donor last about 15-20 years; from a deceased donor, 10-15.)
The decision to decline the vaccine is, of course, each person’s choice, Ms. Ufkes said. But “if they don’t want to be vaccinated [and still want to be on the list], I think that’s BS.”
Citing the lack of organs, “it’s not like they are handing these out like jellybeans.”
A version of this article first appeared on WebMD.com.
Allopurinol found safe in patients with concomitant gout, CKD
Allopurinol treatment is not associated with increased mortality in patients with gout and chronic kidney disease even at 5 years after starting treatment, a study has found.
Around one in five patients with gout also have chronic kidney disease, and previous research suggests that hyperuricemia is itself a contributor to renal disease, which is why there has been interest in the use of serum urate–lowering medication in patients with both conditions.
Since the publication of two earlier randomized controlled trials suggested a twofold increase in mortality among patients with renal disease who were treated with allopurinol in an attempt to slow progression, there has been wariness about the drug in patients with compromised renal function.
In a study published in Annals of Internal Medicine, Jie Wei, PhD, of Xiangya Hospital at Central South University in Changsha, China, and coauthors report the results of their retrospective, population-based study of 5,277 adults aged 40 and older with gout and moderate to severe chronic kidney disease who were initiated on allopurinol and 5,277 matched individuals not on allopurinol.
At 5 years after the patients started allopurinol, the study found that mortality was a statistically significant 15% lower (hazard ratio, 0.85; 95% confidence interval, 0.77-0.93) among those on allopurinol, compared with those not taking the drug. The rate was 4.9 deaths per 100 person-years among those on allopurinol, compared with 5.8 among those not taking it.
The researchers also created two simulated randomized clinical trials from the data for initiators of allopurinol, replicating each initiator twice. The first trial assigned patient replicates either to achieving a target serum urate level of less than 0.36 mmol/L within a year or not achieving it. The second assigned patient replicates to either an allopurinol dose-escalation group or no dose escalation.
For the target serum urate level study, 1,484 achieved the target, and this was associated with a 13% lower hazard ratio for mortality that just missed statistical significance (HR, 0.87; 95% confidence interval, 0.75-1.01).
In the dose-escalation study, there were 773 participants who increased their dose of allopurinol in the first year after initiation – from a median of 100 mg/day to a median final dose of 300 mg/day – and 2,923 who didn’t. Those who escalated their dose had a nonsignificant 12% lower risk of mortality (HR, 0.88; 95% CI, 0.73-1.07), compared with those who didn’t.
The authors suggest that this could be the result of confounding, as patients who achieved target serum urate levels may have been of better health generally than those who didn’t, which could also have contributed to lower mortality.
Coauthor of the study Yuqing Zhang, DSc, of Massachusetts General Hospital and Harvard Medical School, Boston, said there had previously been a theory that allopurinol could protect against progression of renal disease. However, the two randomized, controlled trials in patients with chronic kidney disease but not gout published in 2020 suggested that allopurinol was instead associated with a doubling of mortality in this group.
“This study really shows convincing evidence that among gout patients with renal disease, allopurinol does not increase mortality,” Dr. Zhang told this news organization. He suggested the reason that the earlier studies had found higher mortality among patients on allopurinol was because those patients did not have gout. Given that gout can increase mortality, treating it effectively with allopurinol may therefore reduce mortality even in patients with concurrent chronic kidney disease.
Commenting on the study, Angelo Gaffo, MD, from the Birmingham VA Medical Center and the division of rheumatology at the University of Alabama at Birmingham, said that, while there had been data suggesting increased mortality, the findings from this “very well-done” study were reassuring and even suggested a possible decrease in mortality associated with allopurinol.
“I wouldn’t scream it out loud because it needs confirmation, but it’s something also that we have a sense that could be true,” he said.
Dr. Gaffo noted that patients treated with allopurinol tended to be those with fewer comorbidities. “Patients who have a lot of comorbidities probably are less likely to have their dose of allopurinol started or increased because of some concerns that practitioners may have about putting them on another medicine or increasing the dose of that medicine,” he said.
He also stressed that the findings still need replication in other large database studies, given that a prospective, randomized clinical trial addressing such a question would be difficult to conduct.
The study was supported by the Project Program of National Clinical Research Center for Geriatric Disorders, the National Natural Science Foundation of China, and the U.S. National Institutes of Health. Two authors reported consulting fees from the pharmaceutical sector unrelated to the study. No other conflicts of interest were declared.
A version of this article first appeared on Medscape.com.
Allopurinol treatment is not associated with increased mortality in patients with gout and chronic kidney disease even at 5 years after starting treatment, a study has found.
Around one in five patients with gout also have chronic kidney disease, and previous research suggests that hyperuricemia is itself a contributor to renal disease, which is why there has been interest in the use of serum urate–lowering medication in patients with both conditions.
Since the publication of two earlier randomized controlled trials suggested a twofold increase in mortality among patients with renal disease who were treated with allopurinol in an attempt to slow progression, there has been wariness about the drug in patients with compromised renal function.
In a study published in Annals of Internal Medicine, Jie Wei, PhD, of Xiangya Hospital at Central South University in Changsha, China, and coauthors report the results of their retrospective, population-based study of 5,277 adults aged 40 and older with gout and moderate to severe chronic kidney disease who were initiated on allopurinol and 5,277 matched individuals not on allopurinol.
At 5 years after the patients started allopurinol, the study found that mortality was a statistically significant 15% lower (hazard ratio, 0.85; 95% confidence interval, 0.77-0.93) among those on allopurinol, compared with those not taking the drug. The rate was 4.9 deaths per 100 person-years among those on allopurinol, compared with 5.8 among those not taking it.
The researchers also created two simulated randomized clinical trials from the data for initiators of allopurinol, replicating each initiator twice. The first trial assigned patient replicates either to achieving a target serum urate level of less than 0.36 mmol/L within a year or not achieving it. The second assigned patient replicates to either an allopurinol dose-escalation group or no dose escalation.
For the target serum urate level study, 1,484 achieved the target, and this was associated with a 13% lower hazard ratio for mortality that just missed statistical significance (HR, 0.87; 95% confidence interval, 0.75-1.01).
In the dose-escalation study, there were 773 participants who increased their dose of allopurinol in the first year after initiation – from a median of 100 mg/day to a median final dose of 300 mg/day – and 2,923 who didn’t. Those who escalated their dose had a nonsignificant 12% lower risk of mortality (HR, 0.88; 95% CI, 0.73-1.07), compared with those who didn’t.
The authors suggest that this could be the result of confounding, as patients who achieved target serum urate levels may have been of better health generally than those who didn’t, which could also have contributed to lower mortality.
Coauthor of the study Yuqing Zhang, DSc, of Massachusetts General Hospital and Harvard Medical School, Boston, said there had previously been a theory that allopurinol could protect against progression of renal disease. However, the two randomized, controlled trials in patients with chronic kidney disease but not gout published in 2020 suggested that allopurinol was instead associated with a doubling of mortality in this group.
“This study really shows convincing evidence that among gout patients with renal disease, allopurinol does not increase mortality,” Dr. Zhang told this news organization. He suggested the reason that the earlier studies had found higher mortality among patients on allopurinol was because those patients did not have gout. Given that gout can increase mortality, treating it effectively with allopurinol may therefore reduce mortality even in patients with concurrent chronic kidney disease.
Commenting on the study, Angelo Gaffo, MD, from the Birmingham VA Medical Center and the division of rheumatology at the University of Alabama at Birmingham, said that, while there had been data suggesting increased mortality, the findings from this “very well-done” study were reassuring and even suggested a possible decrease in mortality associated with allopurinol.
“I wouldn’t scream it out loud because it needs confirmation, but it’s something also that we have a sense that could be true,” he said.
Dr. Gaffo noted that patients treated with allopurinol tended to be those with fewer comorbidities. “Patients who have a lot of comorbidities probably are less likely to have their dose of allopurinol started or increased because of some concerns that practitioners may have about putting them on another medicine or increasing the dose of that medicine,” he said.
He also stressed that the findings still need replication in other large database studies, given that a prospective, randomized clinical trial addressing such a question would be difficult to conduct.
The study was supported by the Project Program of National Clinical Research Center for Geriatric Disorders, the National Natural Science Foundation of China, and the U.S. National Institutes of Health. Two authors reported consulting fees from the pharmaceutical sector unrelated to the study. No other conflicts of interest were declared.
A version of this article first appeared on Medscape.com.
Allopurinol treatment is not associated with increased mortality in patients with gout and chronic kidney disease even at 5 years after starting treatment, a study has found.
Around one in five patients with gout also have chronic kidney disease, and previous research suggests that hyperuricemia is itself a contributor to renal disease, which is why there has been interest in the use of serum urate–lowering medication in patients with both conditions.
Since the publication of two earlier randomized controlled trials suggested a twofold increase in mortality among patients with renal disease who were treated with allopurinol in an attempt to slow progression, there has been wariness about the drug in patients with compromised renal function.
In a study published in Annals of Internal Medicine, Jie Wei, PhD, of Xiangya Hospital at Central South University in Changsha, China, and coauthors report the results of their retrospective, population-based study of 5,277 adults aged 40 and older with gout and moderate to severe chronic kidney disease who were initiated on allopurinol and 5,277 matched individuals not on allopurinol.
At 5 years after the patients started allopurinol, the study found that mortality was a statistically significant 15% lower (hazard ratio, 0.85; 95% confidence interval, 0.77-0.93) among those on allopurinol, compared with those not taking the drug. The rate was 4.9 deaths per 100 person-years among those on allopurinol, compared with 5.8 among those not taking it.
The researchers also created two simulated randomized clinical trials from the data for initiators of allopurinol, replicating each initiator twice. The first trial assigned patient replicates either to achieving a target serum urate level of less than 0.36 mmol/L within a year or not achieving it. The second assigned patient replicates to either an allopurinol dose-escalation group or no dose escalation.
For the target serum urate level study, 1,484 achieved the target, and this was associated with a 13% lower hazard ratio for mortality that just missed statistical significance (HR, 0.87; 95% confidence interval, 0.75-1.01).
In the dose-escalation study, there were 773 participants who increased their dose of allopurinol in the first year after initiation – from a median of 100 mg/day to a median final dose of 300 mg/day – and 2,923 who didn’t. Those who escalated their dose had a nonsignificant 12% lower risk of mortality (HR, 0.88; 95% CI, 0.73-1.07), compared with those who didn’t.
The authors suggest that this could be the result of confounding, as patients who achieved target serum urate levels may have been of better health generally than those who didn’t, which could also have contributed to lower mortality.
Coauthor of the study Yuqing Zhang, DSc, of Massachusetts General Hospital and Harvard Medical School, Boston, said there had previously been a theory that allopurinol could protect against progression of renal disease. However, the two randomized, controlled trials in patients with chronic kidney disease but not gout published in 2020 suggested that allopurinol was instead associated with a doubling of mortality in this group.
“This study really shows convincing evidence that among gout patients with renal disease, allopurinol does not increase mortality,” Dr. Zhang told this news organization. He suggested the reason that the earlier studies had found higher mortality among patients on allopurinol was because those patients did not have gout. Given that gout can increase mortality, treating it effectively with allopurinol may therefore reduce mortality even in patients with concurrent chronic kidney disease.
Commenting on the study, Angelo Gaffo, MD, from the Birmingham VA Medical Center and the division of rheumatology at the University of Alabama at Birmingham, said that, while there had been data suggesting increased mortality, the findings from this “very well-done” study were reassuring and even suggested a possible decrease in mortality associated with allopurinol.
“I wouldn’t scream it out loud because it needs confirmation, but it’s something also that we have a sense that could be true,” he said.
Dr. Gaffo noted that patients treated with allopurinol tended to be those with fewer comorbidities. “Patients who have a lot of comorbidities probably are less likely to have their dose of allopurinol started or increased because of some concerns that practitioners may have about putting them on another medicine or increasing the dose of that medicine,” he said.
He also stressed that the findings still need replication in other large database studies, given that a prospective, randomized clinical trial addressing such a question would be difficult to conduct.
The study was supported by the Project Program of National Clinical Research Center for Geriatric Disorders, the National Natural Science Foundation of China, and the U.S. National Institutes of Health. Two authors reported consulting fees from the pharmaceutical sector unrelated to the study. No other conflicts of interest were declared.
A version of this article first appeared on Medscape.com.
FROM ANNALS OF INTERNAL MEDICINE
HIV+ patients get good outcomes after kidney or liver transplant
in new research that represents some of the longest follow-up on these patients to date.
The findings further support the inclusion of people with HIV in transplant resource allocation, say the researchers.
“Overall, the excellent outcomes following liver and kidney transplant recipients in HIV-infected recipients justify the utilization of a scarce resource,” senior author Peter G. Stock, MD, PhD, surgical director of the Kidney and Pancreas Transplant Program and surgical director of the Pediatric Renal Transplant Program at the University of California, San Francisco (UCSF), said in an interview.
“Many centers still view HIV as a strict contraindication [for transplantation]. This data shows it is not,” he emphasized.
The study, published in JAMA Surgery, involved HIV-positive patients who received kidney or liver transplants between 2000 and 2019 at UCSF, which has unique access to some of the longest-term data on those outcomes.
“UCSF was the first U.S. center to do transplants routinely in people with HIV, and based on the large volume of transplants that are performed, we were able to use propensity matching to address the comparison of HIV-positive and negative liver and kidney transplant recipients at a single center,” Dr. Stock explained.
“To the best of our knowledge, there are no long-term reports [greater than 10 years] on [transplant] outcomes in the HIV-positive population.”
Commenting on the study, David Klassen, MD, chief medical officer of the United Network for Organ Sharing (UNOS), noted that the findings “confirm previous research done at UCSF and reported in the New England Journal of Medicine” in 2010. “It extends the previous findings.”
“The take-home message is that these HIV-positive patients can be successfully transplanted with expected good outcomes and will derive substantial benefit from transplantation,” Dr. Klassen said.
Kidney transplant patient survival lower, graft survival similar
For the kidney transplant analysis, 119 HIV-positive recipients were propensity matched with 655 recipients who were HIV-negative, with the patients’ mean age about 52 and approximately 70% male.
At 15-years post-transplant, patient survival was 53.6% among the HIV-positive patients versus 79.6% for HIV-negative (P = .03).
Graft survival among the kidney transplant patients was proportionally higher among HIV-positive patients after 15 years (75% vs. 57%); however, the difference was not statistically significant (P = .77).
First author Arya Zarinsefat, MD, of the Department of Surgery at UCSF, speculated that the lower long-term patient survival among HIV-positive kidney transplant recipients may reflect known cardiovascular risks among those patients.
“We postulated that part of this may be due to the fact that HIV-positive patients certainly have additional comorbidities, specifically cardiovascular” ones, he told this news organization.
“When looking at the survival curve, survival was nearly identical at 5 years and only started to diverge at 10 years post-transplant,” he noted.
A further evaluation of patients with HIV who were co-infected with hepatitis C (HCV) showed that those with HIV-HCV co-infection prior to the center’s introduction of anti-HCV direct-acting antiviral (DAA) medications in 2014 had the lowest survival rate of all subgroups, at 57.1% at 5 years post-transplant (P = .045 vs. those treated after 2014).
Liver transplant patient survival similar
In terms of liver transplant outcomes, among 83 HIV-positive recipients who were propensity-matched with 468 HIV-negative recipients, the mean age was about 53 and about 66% were male.
The patient survival rates at 15 years were not significantly different between the groups, at 70% for HIV-positive and 75.7% for HIV-negative, (P = .12).
Similar to the kidney transplant recipients, the worst survival among all liver transplant subgroups was among HIV-HCV co-infected patients prior to access to HCV direct-acting antivirals in 2014, with a 5-year survival of 59.5% (P = .04).
“Since the advent of HCV direct-acting antivirals, liver transplant outcomes in HCV mono-infected patients are comparable to HCV/HIV co-infected recipients,” Dr. Stock said.
Acute rejection rates higher with HIV-positivity versus national averages
The rates of acute rejection at 1 year in the kidney and liver transplant, HIV-positive groups – at about 20% and 30%, respectively – were, however, higher than national average incidence rates of about 10% at 1 year.
Long-term data on those patients showed the acute rejection affected graft survival outcomes with kidney transplant recipients: HIV-positive kidney transplant recipients who had at least one episode of acute rejection had a graft survival of just 52.8% at 15 years post-transplant, compared with 91.8% among recipients without acute rejection.
Such differences were not observed among HIV-positive liver transplant recipients.
The authors note that the increased risk of acute rejection in HIV-positive kidney transplant patients is consistent with previous studies, with causes that may be multifactorial.
Top theories include drug interactions with protease inhibitors, resulting in some centers transitioning HIV-infected patients from those regimens to integrase-based regimens prior to transplant.
“The management and prevention of acute rejection in HIV-positive kidney transplant [patients] will therefore continue to be a key component in the care of these patients,” the authors note in their study.
The study was supported in part by the National Institutes of Health. The study authors and Dr. Klassen have disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.
in new research that represents some of the longest follow-up on these patients to date.
The findings further support the inclusion of people with HIV in transplant resource allocation, say the researchers.
“Overall, the excellent outcomes following liver and kidney transplant recipients in HIV-infected recipients justify the utilization of a scarce resource,” senior author Peter G. Stock, MD, PhD, surgical director of the Kidney and Pancreas Transplant Program and surgical director of the Pediatric Renal Transplant Program at the University of California, San Francisco (UCSF), said in an interview.
“Many centers still view HIV as a strict contraindication [for transplantation]. This data shows it is not,” he emphasized.
The study, published in JAMA Surgery, involved HIV-positive patients who received kidney or liver transplants between 2000 and 2019 at UCSF, which has unique access to some of the longest-term data on those outcomes.
“UCSF was the first U.S. center to do transplants routinely in people with HIV, and based on the large volume of transplants that are performed, we were able to use propensity matching to address the comparison of HIV-positive and negative liver and kidney transplant recipients at a single center,” Dr. Stock explained.
“To the best of our knowledge, there are no long-term reports [greater than 10 years] on [transplant] outcomes in the HIV-positive population.”
Commenting on the study, David Klassen, MD, chief medical officer of the United Network for Organ Sharing (UNOS), noted that the findings “confirm previous research done at UCSF and reported in the New England Journal of Medicine” in 2010. “It extends the previous findings.”
“The take-home message is that these HIV-positive patients can be successfully transplanted with expected good outcomes and will derive substantial benefit from transplantation,” Dr. Klassen said.
Kidney transplant patient survival lower, graft survival similar
For the kidney transplant analysis, 119 HIV-positive recipients were propensity matched with 655 recipients who were HIV-negative, with the patients’ mean age about 52 and approximately 70% male.
At 15-years post-transplant, patient survival was 53.6% among the HIV-positive patients versus 79.6% for HIV-negative (P = .03).
Graft survival among the kidney transplant patients was proportionally higher among HIV-positive patients after 15 years (75% vs. 57%); however, the difference was not statistically significant (P = .77).
First author Arya Zarinsefat, MD, of the Department of Surgery at UCSF, speculated that the lower long-term patient survival among HIV-positive kidney transplant recipients may reflect known cardiovascular risks among those patients.
“We postulated that part of this may be due to the fact that HIV-positive patients certainly have additional comorbidities, specifically cardiovascular” ones, he told this news organization.
“When looking at the survival curve, survival was nearly identical at 5 years and only started to diverge at 10 years post-transplant,” he noted.
A further evaluation of patients with HIV who were co-infected with hepatitis C (HCV) showed that those with HIV-HCV co-infection prior to the center’s introduction of anti-HCV direct-acting antiviral (DAA) medications in 2014 had the lowest survival rate of all subgroups, at 57.1% at 5 years post-transplant (P = .045 vs. those treated after 2014).
Liver transplant patient survival similar
In terms of liver transplant outcomes, among 83 HIV-positive recipients who were propensity-matched with 468 HIV-negative recipients, the mean age was about 53 and about 66% were male.
The patient survival rates at 15 years were not significantly different between the groups, at 70% for HIV-positive and 75.7% for HIV-negative, (P = .12).
Similar to the kidney transplant recipients, the worst survival among all liver transplant subgroups was among HIV-HCV co-infected patients prior to access to HCV direct-acting antivirals in 2014, with a 5-year survival of 59.5% (P = .04).
“Since the advent of HCV direct-acting antivirals, liver transplant outcomes in HCV mono-infected patients are comparable to HCV/HIV co-infected recipients,” Dr. Stock said.
Acute rejection rates higher with HIV-positivity versus national averages
The rates of acute rejection at 1 year in the kidney and liver transplant, HIV-positive groups – at about 20% and 30%, respectively – were, however, higher than national average incidence rates of about 10% at 1 year.
Long-term data on those patients showed the acute rejection affected graft survival outcomes with kidney transplant recipients: HIV-positive kidney transplant recipients who had at least one episode of acute rejection had a graft survival of just 52.8% at 15 years post-transplant, compared with 91.8% among recipients without acute rejection.
Such differences were not observed among HIV-positive liver transplant recipients.
The authors note that the increased risk of acute rejection in HIV-positive kidney transplant patients is consistent with previous studies, with causes that may be multifactorial.
Top theories include drug interactions with protease inhibitors, resulting in some centers transitioning HIV-infected patients from those regimens to integrase-based regimens prior to transplant.
“The management and prevention of acute rejection in HIV-positive kidney transplant [patients] will therefore continue to be a key component in the care of these patients,” the authors note in their study.
The study was supported in part by the National Institutes of Health. The study authors and Dr. Klassen have disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.
in new research that represents some of the longest follow-up on these patients to date.
The findings further support the inclusion of people with HIV in transplant resource allocation, say the researchers.
“Overall, the excellent outcomes following liver and kidney transplant recipients in HIV-infected recipients justify the utilization of a scarce resource,” senior author Peter G. Stock, MD, PhD, surgical director of the Kidney and Pancreas Transplant Program and surgical director of the Pediatric Renal Transplant Program at the University of California, San Francisco (UCSF), said in an interview.
“Many centers still view HIV as a strict contraindication [for transplantation]. This data shows it is not,” he emphasized.
The study, published in JAMA Surgery, involved HIV-positive patients who received kidney or liver transplants between 2000 and 2019 at UCSF, which has unique access to some of the longest-term data on those outcomes.
“UCSF was the first U.S. center to do transplants routinely in people with HIV, and based on the large volume of transplants that are performed, we were able to use propensity matching to address the comparison of HIV-positive and negative liver and kidney transplant recipients at a single center,” Dr. Stock explained.
“To the best of our knowledge, there are no long-term reports [greater than 10 years] on [transplant] outcomes in the HIV-positive population.”
Commenting on the study, David Klassen, MD, chief medical officer of the United Network for Organ Sharing (UNOS), noted that the findings “confirm previous research done at UCSF and reported in the New England Journal of Medicine” in 2010. “It extends the previous findings.”
“The take-home message is that these HIV-positive patients can be successfully transplanted with expected good outcomes and will derive substantial benefit from transplantation,” Dr. Klassen said.
Kidney transplant patient survival lower, graft survival similar
For the kidney transplant analysis, 119 HIV-positive recipients were propensity matched with 655 recipients who were HIV-negative, with the patients’ mean age about 52 and approximately 70% male.
At 15-years post-transplant, patient survival was 53.6% among the HIV-positive patients versus 79.6% for HIV-negative (P = .03).
Graft survival among the kidney transplant patients was proportionally higher among HIV-positive patients after 15 years (75% vs. 57%); however, the difference was not statistically significant (P = .77).
First author Arya Zarinsefat, MD, of the Department of Surgery at UCSF, speculated that the lower long-term patient survival among HIV-positive kidney transplant recipients may reflect known cardiovascular risks among those patients.
“We postulated that part of this may be due to the fact that HIV-positive patients certainly have additional comorbidities, specifically cardiovascular” ones, he told this news organization.
“When looking at the survival curve, survival was nearly identical at 5 years and only started to diverge at 10 years post-transplant,” he noted.
A further evaluation of patients with HIV who were co-infected with hepatitis C (HCV) showed that those with HIV-HCV co-infection prior to the center’s introduction of anti-HCV direct-acting antiviral (DAA) medications in 2014 had the lowest survival rate of all subgroups, at 57.1% at 5 years post-transplant (P = .045 vs. those treated after 2014).
Liver transplant patient survival similar
In terms of liver transplant outcomes, among 83 HIV-positive recipients who were propensity-matched with 468 HIV-negative recipients, the mean age was about 53 and about 66% were male.
The patient survival rates at 15 years were not significantly different between the groups, at 70% for HIV-positive and 75.7% for HIV-negative, (P = .12).
Similar to the kidney transplant recipients, the worst survival among all liver transplant subgroups was among HIV-HCV co-infected patients prior to access to HCV direct-acting antivirals in 2014, with a 5-year survival of 59.5% (P = .04).
“Since the advent of HCV direct-acting antivirals, liver transplant outcomes in HCV mono-infected patients are comparable to HCV/HIV co-infected recipients,” Dr. Stock said.
Acute rejection rates higher with HIV-positivity versus national averages
The rates of acute rejection at 1 year in the kidney and liver transplant, HIV-positive groups – at about 20% and 30%, respectively – were, however, higher than national average incidence rates of about 10% at 1 year.
Long-term data on those patients showed the acute rejection affected graft survival outcomes with kidney transplant recipients: HIV-positive kidney transplant recipients who had at least one episode of acute rejection had a graft survival of just 52.8% at 15 years post-transplant, compared with 91.8% among recipients without acute rejection.
Such differences were not observed among HIV-positive liver transplant recipients.
The authors note that the increased risk of acute rejection in HIV-positive kidney transplant patients is consistent with previous studies, with causes that may be multifactorial.
Top theories include drug interactions with protease inhibitors, resulting in some centers transitioning HIV-infected patients from those regimens to integrase-based regimens prior to transplant.
“The management and prevention of acute rejection in HIV-positive kidney transplant [patients] will therefore continue to be a key component in the care of these patients,” the authors note in their study.
The study was supported in part by the National Institutes of Health. The study authors and Dr. Klassen have disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.
Pheochromocytoma: An Incidental Finding in an Asymptomatic Older Adult With Renal Oncocytoma
A high index of suspicion for pheochromocytoma is necessary during the workup of secondary hypertension as untreated pheochromocytoma may lead to significant morbidity and mortality, especially in patients who require any surgical treatment.
Pheochromocytoma is a rare catecholamine-secreting tumor of chromaffin cells of the adrenal medulla or sympathetic ganglia, occurring in about 0.2 to 0.5% of patients with hypertension.1-3 However, in a review of 54 autopsy-proven cases of pheochromocytoma, about 50% of the patients with hypertension were not clinically suspected for pheochromocytoma.4
Pheochromocytoma is usually diagnosed based on symptoms of hyperadrenergic spells, resistant hypertension, especially in the young, with a pressor response to the anesthesia stress test and adrenal incidentaloma.
The classic triad of symptoms associated with pheochromocytoma includes episodic headache (90%), sweating (60-70%), and palpitations (70%).2,5 Sustained or paroxysmal hypertension is the most common symptom reported in about 95% of patients with pheochromocytoma. Other symptoms include pallor, tremors, dyspnea, generalized weakness, orthostatic hypotension, cardiomyopathy, or hyperglycemia.6 However, about 10% of patients with pheochromocytoma are asymptomatic or mildly symptomatic.7 Secondary causes of hypertension are usually suspected in multidrug resistant or sudden early onset of hypertension.8
Approximately 10% of catecholamine-secreting tumors are malignant.9-11 Benign and malignant pheochromocytoma have a similar biochemical and histologic presentation and are differentiated based on local invasion into the surrounding tissues and organs (eg, kidney, liver) or distant metastasis.
A typical workup of a suspected patient with pheochromocytoma includes biochemical tests, including measurements of urinary and fractionated plasma metanephrines and catecholamine. Patients with positive biochemical tests should undergo localization of the tumor with an imaging study either with an adrenal/abdominal magnetic resonance imaging (MRI) or computed tomography (CT) scan. If a patient has paraganglioma or an adrenal mass > 10 cm or negative abdominal imaging with a positive biochemical test, further imaging with an iobenguane I-123 scan is needed (Figure 1).
In this article, we present an unusual case of asymptomatic pheochromocytoma in a patient with right-sided renal oncocytoma who underwent an uneventful nephrectomy and adrenalectomy.
Case Presentation
A 72-year-old male with a medical history of diabetes, hypertension, sensory neuropathy, benign prostatic hypertrophy (BPH) status posttransurethral resection of the prostate, and chronic renal failure presented to establish care with the Arizona Kidney Disease and Hypertension Center. His medications included losartan 50 mg by mouth daily, diltiazem 180 mg extended-release by mouth daily, carvedilol 6.25 mg by mouth twice a day, and tamsulosin 0.4 mg by mouth daily. His presenting vitals were blood pressure (BP), 112/74 left arm sitting, pulse, 63/beats per min, and body mass index, 34. On physical examination, the patient was alert and oriented, and the chest was clear to auscultation without wheeze or rhonchi. On cardiac examination, heart rate and rhythm were regular; S1 and S2 were normal with no added murmurs, rubs or gallops, and no jugular venous distension. The abdomen was soft, nontender, with no palpable mass. His laboratory results showed sodium, 142 mmol/L; potassium, 5.3 mmol/L; chloride, 101 mmol/L; carbon dioxide, 24 mmol/L; albumin, 4.3 g/dL; creatinine, 1.89 mg/dL; blood urea nitrogen, 29 mg/dL; estimated glomerular filtration rate non-African American, 35 mL/min/1.73; 24-h urine creatinine clearance, 105 mL/min; protein, 1306 mg/24 h (Table).
His renal ultrasound showed an exophytic isoechoic mass or complex cyst at the lateral aspect of the lower pole of the right kidney, measuring 45 mm in diameter. An MRI of the abdomen with and without contrast showed a solid partially exophytic mass of the posterolateral interpolar cortex of the right kidney, measuring 5.9 cm in the greatest dimension (Figure 2). No definite involvement of Gerota fascia was noted, a 1-cm metastasis to the right adrenal gland was present, renal veins were patent, and there was no upper retroperitoneal lymphadenopathy.
Treatment and Follow-up
The patient underwent right-hand-assisted lap-aroscopic radical nephrectomy and right adre-nalectomy without any complications. However, the surgical pathology report showed oncocytoma of the kidney (5.7 cm), pheochromocytoma of the adrenal gland (1.4 cm), and papillary adenoma of the kidney (0.7 cm). Right kidney nephrectomy showed non-neoplastic renal parenchyma, diabetic glomerulosclerosis (Renal Pathology Society 2010 diabetic nephropathy class IIb), severe mesangial expansion, moderate interstitial fibrosis, moderate arteriosclerosis, and mild arteriolosclerosis.
A fluorodeoxyglucose-positron emission tomography (FDG-PET) scan was significant for right nephrectomy and adrenalectomy and showed no significant evidence of residual neoplasm or local or distant metastases. A nuclear medicine (iobenguane I-123) tumor and single positron emission computed tomography (SPECT) scan showed normal activity throughout the body and no evidence of abnormal activity (Figure 3).
Discussion
Pheochromocytoma is a rare cause of secondary hypertension. However, the real numbers are thought to be > 0.2 to 0.5%.1,2,4 Patients with pheochromocytoma should undergo surgical adrenal resection after appropriate medical preparation. Patients with pheochromocytoma who are not diagnosed preoperatively have increased surgical mortality rates due to fatal hypertensive crises, malignant arrhythmia, and multiorgan failure as a result of hypertensive crisis.15 Anesthetic drugs during surgery also can exacerbate the cardiotoxic effects of catecholamines. Short-acting anesthetic agents, such as fentanyl, are used in patients with pheochromocytoma.16
This case of pheochromocytoma illustrated no classic symptoms of episodic headache, sweating, and tachycardia, and the patient was otherwise asymptomatic. BP was well controlled with losartan, diltiazem, and a β-blocker with α-blocking activity (carvedilol). As the patient was not known to have pheochromocytoma, he did not undergo preoperative medical therapy. Figure 4 illustrates the receptors stimulate catecholamines, and the drugs blocking these receptors prevent hypertensive crisis during surgery. However, the surgery was without potential complications (ie, hypertensive crisis, malignant arrhythmia, or multiorgan failure). The patient was diagnosed incidentally on histopathology after right radical nephrectomy and adrenalectomy due to solid partially exophytic right renal mass (5.9 cm) with right adrenal metastasis. About 10% of patients are asymptomatic or mildly symptomatic.7 Sometimes, the symptoms may be ignored because of the episodic nature. Other possible reasons can be small, nonfunctional tumors or the use of antihypertensive medications suppressing the symptoms.7
The adrenal mass that was initially thought to be a metastasis of right kidney mass was later confirmed as pheochromocytoma. One possible explanation for uneventful surgery could be the use of β-blocker with α-blocking activity (carvedilol), α-1 adrenergic blocker (tamsulosin) along with nondihydropyridine calcium channel blocker (diltiazem) as part of the patient’s antihypertensive and BPH medication regimen. Another possible explanation could be silent or episodically secreting pheochromocytoma with a small functional portion.
Subsequent workup after adrenalectomy, including urinary and fractionated plasma metanephrines and catecholamines, were not consistent with catecholamine hypersecretion. A 24-hour urine fractionated metanephrines test has about 98% sensitivity and 98% specificity. Elevated plasma norepinephrine was thought to be due to renal failure because it was < 3-fold the upper limit of normal, which is considered to be a possible indication of pheochromocytoma.17,18 The nuclear medicine (iobenguane I-123) tumor, SPECT, and FDG-PET CT studies were negative for residual pheochromocytoma. Other imaging studies to consider in patients with suspected catecholamine-secreting tumor with positive biochemical test and negative abdominal imaging are a whole-body MRI scan, 68-Ga DOTATATE (gallium 68 1,4,7,10-tetraazacyclododecane-1,4,7,10 tetraacetic acid-octreotate) or FDG-PET scan.19
In a review of 54 autopsy-proven pheochromocytoma cases by Sutton and colleagues in 1981, 74% of the patients were not clinically suspected for pheochromocytoma in their life.4 Similarly, in a retrospective study of hospital autopsies by McNeil and colleagues, one incidental pheochromocytoma was detected in every 2031 autopsies (0.05%).20 In another case series of 41 patients with pheochromocytoma-related adrenalectomy, almost 50% of the pheochromocytomas were detected incidentally on imaging studies.21 Although the number of incidental findings are decreasing due to advances in screening techniques, a significant number of patients remain undiagnosed. Multiple cases of diagnosis of pheochromocytoma on autopsy of patients who died of hemodynamic instability (ie, hypertensive crisis, hypotension crisis precipitated by surgery for adrenal or nonadrenal conditions) are reported.3 To the best of our knowledge, there are no case reports published on the diagnosis of pheochromocytoma after adrenalectomy in an asymptomatic patient without intraoperative complications.
The goal of preoperative medical therapy includes BP control, prevention of tachycardia, and volume expansion. The preoperative medications regimens are combined α- and β-adrenergic blockade, calcium channel blockers, and metyrosine. According to clinical practice guidelines of the Endocrine Society in 2014, the α-adrenergic blockers should be started first at least 7 days before surgery to control BP and to cause vasodilation. Early use of α-blockers is required to prevent cardiotoxicity. The β-adrenergic blockers should be started after the adequate α-adrenergic blockade, typically 2 to 3 days before surgery, as early use can cause vasoconstriction in patients with pheochromocytoma. The α-adrenergic blockers include phenoxybenzamine (nonselective long-acting nonspecific α-adrenergic blocking agent), and selective α-1 adrenergic blockers (doxazosin, prazosin, terazosin). The β-adrenergic blocker (ie, propranolol, metoprolol) should be started cautiously with a low dose and slowly titrated to control heart rate. A high sodium diet and increased fluid intake also are recommended 7 to 14 days before surgery. A sudden drop in catecholamines can cause hypotension during an operation. Continuous fluid infusions are given to prevent hypotension.22 Similarly, anesthetic agents also should be modified to prevent cardiotoxic effects. Rocuronium and vecuronium are less cardiotoxic compared with other sympathomimetic muscle relaxants. Short-acting anesthetic agents, such as fentanyl, are preferred. α-blockers are continued throughout the operation. Biochemical testing with fractionated metanephrines is performed about 1 to 2 weeks postoperatively to look for recurrence of the disease.23
Secondary causes of hypertension are suspected in multidrug resistant or sudden early onset of hypertension before aged 40 years. Pheochromocytoma is a rare cause of secondary hypertension, and older adult patients are rarely diagnosed with pheochromocytoma.24 In this report, pheochromocytoma was detected in a 72-year-old hypertensive patient. Therefore, a pheochromocytoma diagnosis should not be ignored in the older adult patient with adrenal mass and hypertension treated with more than one drug. The authors recommend any patient undergoing surgery with adrenal lesion should be considered for the screening of possible pheochromocytoma and prepared preoperatively, especially any patient with renal cell carcinoma with adrenal metastasis.
Conclusions
Asymptomatic pheochromocytoma is an unusual but serious condition, especially for patients undergoing a surgical procedure. An adrenal mass may be ignored in asymptomatic or mildly symptomatic older adult patients and is mostly considered as adrenal metastasis when present with other malignancies. Fortunately, the nephrectomy and adrenalectomy in our case of asymptomatic pheochromocytoma was uneventful, but pheochromocytoma should be ruled out before a surgical procedure, as an absence of medical pretreatment can lead to serious consequences. Therefore, we suggest a more careful screening of pheochromocytoma in patients with an adrenal mass (primary or metastatic) and hypertension treated with multiple antihypertensive drugs, even in older adult patients.
1. Omura M, Saito J, Yamaguchi K, Kakuta Y, Nishikawa T. Prospective study on the prevalence of secondary hypertension among hypertensive patients visiting a general outpatient clinic in Japan. Hypertens Res. 2004;27(3):193-202. doi:10.1291/hypres.27.193
2. Stein PP, Black HR. A simplified diagnostic approach to pheochromocytoma: a review of the literature and report of one institution’s experience. Medicine (Baltimore). 1991;70(1):46-66. doi:10.1097/00005792-199101000-00004
3. Beard CM, Sheps SG, Kurland LT, Carney JA, Lie JT. Occurrence of pheochromocytoma in Rochester, Minnesota, 1950 through 1979. Mayo Clin Proc. 1983;58(12):802-804.
4. Sutton MG, Sheps SG, Lie JT. Prevalence of clinically unsuspected pheochromocytoma: review of a 50-year autopsy series. Mayo Clin Proc. 1981;56(6):354-360.
5. Manger WM, Gifford RW Jr. Pheochromocytoma. J Clin Hypertens (Greenwich). 2002;4(1):62-72. doi:10.1111/j.1524-6175.2002.01452.x
6. Kassim TA, Clarke DD, Mai VQ, Clyde PW, Mohamed Shakir KM. Catecholamine-induced cardiomyopathy. Endocr Pract. 2008;14(9):1137-1149. doi:10.4158/EP.14.9.1137
7. Kudva YC, Young WF, Thompson GB, Grant CS, Van Heerden JA. Adrenal incidentaloma: an important component of the clinical presentation spectrum of benign sporadic adrenal pheochromocytoma. The Endocrinologist. 1999;9(2):77-80. doi:10.1097/00019616-199903000-00002
8. Puar TH, Mok Y, Debajyoti R, Khoo J, How CH, Ng AK. Secondary hypertension in adults. Singapore Med J. 2016;57(5):228-232. doi:10.11622/smedj.2016087
9. Bravo EL. Pheochromocytoma: new concepts and future trends. Kidney Int. 1991;40(3):544-556. doi:10.1038/ki.1991.244
10. Plouin PF, Chatellier G, Fofol I, Corvol P. Tumor recurrence and hypertension persistence after successful pheochromocytoma operation. Hypertension. 1997;29(5):1133-1139. doi:10.1161/01.hyp.29.5.1133
11. Hamidi O, Young WF Jr, Iñiguez-Ariza NM, et al. Malignant pheochromocytoma and paraganglioma: 272 patients over 55 years. J Clin Endocrinol Metab. 2017;102(9):3296-3305. doi:10.1210/jc.2017-00992
12. Kenny L, Rizzo V, Trevis J, Assimakopoulou E, Timon D. The unexpected diagnosis of phaeochromocytoma in the anaesthetic room. Ann Card Anaesth. 2018;21(3):307-310. doi:10.4103/aca.ACA_206_17
13. Johnston PC, Silversides JA, Wallace H, et al. Phaeochromocytoma crisis: two cases of undiagnosed phaeochromocytoma presenting after elective nonrelated surgical procedures. Case Rep Anesthesiol. 2013;2013:514714. doi:10.1155/2013/514714
14. Shen SJ, Cheng HM, Chiu AW, Chou CW, Chen JY. Perioperative hypertensive crisis in clinically silent pheochromocytomas: report of four cases. Chang Gung Med J. 2005;28(1):44-50.
15. Lo CY, Lam KY, Wat MS, Lam KS. Adrenal pheochromocytoma remains a frequently overlooked diagnosis. Am J Surg. 2000;179(3):212-215. doi:10.1016/s0002-9610(00)00296-8
16. Myklejord DJ. Undiagnosed pheochromocytoma: the anesthesiologist nightmare. Clin Med Res. 2004;2(1):59-62. doi:10.3121/cmr.2.1.59
17. Stumvoll M, Radjaipour M, Seif F. Diagnostic considerations in pheochromocytoma and chronic hemodialysis: case report and review of the literature. Am J Nephrol. 1995;15(2):147-151. doi:10.1159/000168820
18. Morioka M, Yuihama S, Nakajima T, et al. Incidentally discovered pheochromocytoma in long-term hemodialysis patients. Int J Urol. 2002;9(12):700-703. doi:10.1046/j.1442-2042.2002.00553.x
19. ˇCtvrtlík F, Koranda P, Schovánek J, Škarda J, Hartmann I, Tüdös Z. Current diagnostic imaging of pheochromocytomas and implications for therapeutic strategy. Exp Ther Med. 2018;15(4):3151-3160. doi:10.3892/etm.2018.5871
20. McNeil AR, Blok BH, Koelmeyer TD, Burke MP, Hilton JM. Phaeochromocytomas discovered during coronial autopsies in Sydney, Melbourne and Auckland. Aust N Z J Med. 2000;30(6):648-652. doi:10.1111/j.1445-5994.2000.tb04358.x
21. Baguet JP, Hammer L, Mazzuco TL, et al. Circumstances of discovery of phaeochromocytoma: a retrospective study of 41 consecutive patients. Eur J Endocrinol. 2004;150(5):681-686. doi:10.1530/eje.0.1500681
22. Lenders JW, Duh QY, Eisenhofer G, et al. Pheochromocytoma and paraganglioma: an endocrine society clinical practice guideline. J Clin Endocrinol Metab. 2014;99(6):1915-1942. doi:10.1210/jc.2014-1498
23. Dortzbach K, Gainsburg DM, Frost EA. Variants of pheochromocytoma and their anesthetic implications--a case report and literature review. Middle East J Anaesthesiol. 2010;20(6):897-905.
24. Januszewicz W, Chodakowska J, Styczy´nski G. Secondary hypertension in the elderly. J Hum Hypertens. 1998;12(9):603-606. doi:10.1038/sj.jhh.1000673
A high index of suspicion for pheochromocytoma is necessary during the workup of secondary hypertension as untreated pheochromocytoma may lead to significant morbidity and mortality, especially in patients who require any surgical treatment.
A high index of suspicion for pheochromocytoma is necessary during the workup of secondary hypertension as untreated pheochromocytoma may lead to significant morbidity and mortality, especially in patients who require any surgical treatment.
Pheochromocytoma is a rare catecholamine-secreting tumor of chromaffin cells of the adrenal medulla or sympathetic ganglia, occurring in about 0.2 to 0.5% of patients with hypertension.1-3 However, in a review of 54 autopsy-proven cases of pheochromocytoma, about 50% of the patients with hypertension were not clinically suspected for pheochromocytoma.4
Pheochromocytoma is usually diagnosed based on symptoms of hyperadrenergic spells, resistant hypertension, especially in the young, with a pressor response to the anesthesia stress test and adrenal incidentaloma.
The classic triad of symptoms associated with pheochromocytoma includes episodic headache (90%), sweating (60-70%), and palpitations (70%).2,5 Sustained or paroxysmal hypertension is the most common symptom reported in about 95% of patients with pheochromocytoma. Other symptoms include pallor, tremors, dyspnea, generalized weakness, orthostatic hypotension, cardiomyopathy, or hyperglycemia.6 However, about 10% of patients with pheochromocytoma are asymptomatic or mildly symptomatic.7 Secondary causes of hypertension are usually suspected in multidrug resistant or sudden early onset of hypertension.8
Approximately 10% of catecholamine-secreting tumors are malignant.9-11 Benign and malignant pheochromocytoma have a similar biochemical and histologic presentation and are differentiated based on local invasion into the surrounding tissues and organs (eg, kidney, liver) or distant metastasis.
A typical workup of a suspected patient with pheochromocytoma includes biochemical tests, including measurements of urinary and fractionated plasma metanephrines and catecholamine. Patients with positive biochemical tests should undergo localization of the tumor with an imaging study either with an adrenal/abdominal magnetic resonance imaging (MRI) or computed tomography (CT) scan. If a patient has paraganglioma or an adrenal mass > 10 cm or negative abdominal imaging with a positive biochemical test, further imaging with an iobenguane I-123 scan is needed (Figure 1).
In this article, we present an unusual case of asymptomatic pheochromocytoma in a patient with right-sided renal oncocytoma who underwent an uneventful nephrectomy and adrenalectomy.
Case Presentation
A 72-year-old male with a medical history of diabetes, hypertension, sensory neuropathy, benign prostatic hypertrophy (BPH) status posttransurethral resection of the prostate, and chronic renal failure presented to establish care with the Arizona Kidney Disease and Hypertension Center. His medications included losartan 50 mg by mouth daily, diltiazem 180 mg extended-release by mouth daily, carvedilol 6.25 mg by mouth twice a day, and tamsulosin 0.4 mg by mouth daily. His presenting vitals were blood pressure (BP), 112/74 left arm sitting, pulse, 63/beats per min, and body mass index, 34. On physical examination, the patient was alert and oriented, and the chest was clear to auscultation without wheeze or rhonchi. On cardiac examination, heart rate and rhythm were regular; S1 and S2 were normal with no added murmurs, rubs or gallops, and no jugular venous distension. The abdomen was soft, nontender, with no palpable mass. His laboratory results showed sodium, 142 mmol/L; potassium, 5.3 mmol/L; chloride, 101 mmol/L; carbon dioxide, 24 mmol/L; albumin, 4.3 g/dL; creatinine, 1.89 mg/dL; blood urea nitrogen, 29 mg/dL; estimated glomerular filtration rate non-African American, 35 mL/min/1.73; 24-h urine creatinine clearance, 105 mL/min; protein, 1306 mg/24 h (Table).
His renal ultrasound showed an exophytic isoechoic mass or complex cyst at the lateral aspect of the lower pole of the right kidney, measuring 45 mm in diameter. An MRI of the abdomen with and without contrast showed a solid partially exophytic mass of the posterolateral interpolar cortex of the right kidney, measuring 5.9 cm in the greatest dimension (Figure 2). No definite involvement of Gerota fascia was noted, a 1-cm metastasis to the right adrenal gland was present, renal veins were patent, and there was no upper retroperitoneal lymphadenopathy.
Treatment and Follow-up
The patient underwent right-hand-assisted lap-aroscopic radical nephrectomy and right adre-nalectomy without any complications. However, the surgical pathology report showed oncocytoma of the kidney (5.7 cm), pheochromocytoma of the adrenal gland (1.4 cm), and papillary adenoma of the kidney (0.7 cm). Right kidney nephrectomy showed non-neoplastic renal parenchyma, diabetic glomerulosclerosis (Renal Pathology Society 2010 diabetic nephropathy class IIb), severe mesangial expansion, moderate interstitial fibrosis, moderate arteriosclerosis, and mild arteriolosclerosis.
A fluorodeoxyglucose-positron emission tomography (FDG-PET) scan was significant for right nephrectomy and adrenalectomy and showed no significant evidence of residual neoplasm or local or distant metastases. A nuclear medicine (iobenguane I-123) tumor and single positron emission computed tomography (SPECT) scan showed normal activity throughout the body and no evidence of abnormal activity (Figure 3).
Discussion
Pheochromocytoma is a rare cause of secondary hypertension. However, the real numbers are thought to be > 0.2 to 0.5%.1,2,4 Patients with pheochromocytoma should undergo surgical adrenal resection after appropriate medical preparation. Patients with pheochromocytoma who are not diagnosed preoperatively have increased surgical mortality rates due to fatal hypertensive crises, malignant arrhythmia, and multiorgan failure as a result of hypertensive crisis.15 Anesthetic drugs during surgery also can exacerbate the cardiotoxic effects of catecholamines. Short-acting anesthetic agents, such as fentanyl, are used in patients with pheochromocytoma.16
This case of pheochromocytoma illustrated no classic symptoms of episodic headache, sweating, and tachycardia, and the patient was otherwise asymptomatic. BP was well controlled with losartan, diltiazem, and a β-blocker with α-blocking activity (carvedilol). As the patient was not known to have pheochromocytoma, he did not undergo preoperative medical therapy. Figure 4 illustrates the receptors stimulate catecholamines, and the drugs blocking these receptors prevent hypertensive crisis during surgery. However, the surgery was without potential complications (ie, hypertensive crisis, malignant arrhythmia, or multiorgan failure). The patient was diagnosed incidentally on histopathology after right radical nephrectomy and adrenalectomy due to solid partially exophytic right renal mass (5.9 cm) with right adrenal metastasis. About 10% of patients are asymptomatic or mildly symptomatic.7 Sometimes, the symptoms may be ignored because of the episodic nature. Other possible reasons can be small, nonfunctional tumors or the use of antihypertensive medications suppressing the symptoms.7
The adrenal mass that was initially thought to be a metastasis of right kidney mass was later confirmed as pheochromocytoma. One possible explanation for uneventful surgery could be the use of β-blocker with α-blocking activity (carvedilol), α-1 adrenergic blocker (tamsulosin) along with nondihydropyridine calcium channel blocker (diltiazem) as part of the patient’s antihypertensive and BPH medication regimen. Another possible explanation could be silent or episodically secreting pheochromocytoma with a small functional portion.
Subsequent workup after adrenalectomy, including urinary and fractionated plasma metanephrines and catecholamines, were not consistent with catecholamine hypersecretion. A 24-hour urine fractionated metanephrines test has about 98% sensitivity and 98% specificity. Elevated plasma norepinephrine was thought to be due to renal failure because it was < 3-fold the upper limit of normal, which is considered to be a possible indication of pheochromocytoma.17,18 The nuclear medicine (iobenguane I-123) tumor, SPECT, and FDG-PET CT studies were negative for residual pheochromocytoma. Other imaging studies to consider in patients with suspected catecholamine-secreting tumor with positive biochemical test and negative abdominal imaging are a whole-body MRI scan, 68-Ga DOTATATE (gallium 68 1,4,7,10-tetraazacyclododecane-1,4,7,10 tetraacetic acid-octreotate) or FDG-PET scan.19
In a review of 54 autopsy-proven pheochromocytoma cases by Sutton and colleagues in 1981, 74% of the patients were not clinically suspected for pheochromocytoma in their life.4 Similarly, in a retrospective study of hospital autopsies by McNeil and colleagues, one incidental pheochromocytoma was detected in every 2031 autopsies (0.05%).20 In another case series of 41 patients with pheochromocytoma-related adrenalectomy, almost 50% of the pheochromocytomas were detected incidentally on imaging studies.21 Although the number of incidental findings are decreasing due to advances in screening techniques, a significant number of patients remain undiagnosed. Multiple cases of diagnosis of pheochromocytoma on autopsy of patients who died of hemodynamic instability (ie, hypertensive crisis, hypotension crisis precipitated by surgery for adrenal or nonadrenal conditions) are reported.3 To the best of our knowledge, there are no case reports published on the diagnosis of pheochromocytoma after adrenalectomy in an asymptomatic patient without intraoperative complications.
The goal of preoperative medical therapy includes BP control, prevention of tachycardia, and volume expansion. The preoperative medications regimens are combined α- and β-adrenergic blockade, calcium channel blockers, and metyrosine. According to clinical practice guidelines of the Endocrine Society in 2014, the α-adrenergic blockers should be started first at least 7 days before surgery to control BP and to cause vasodilation. Early use of α-blockers is required to prevent cardiotoxicity. The β-adrenergic blockers should be started after the adequate α-adrenergic blockade, typically 2 to 3 days before surgery, as early use can cause vasoconstriction in patients with pheochromocytoma. The α-adrenergic blockers include phenoxybenzamine (nonselective long-acting nonspecific α-adrenergic blocking agent), and selective α-1 adrenergic blockers (doxazosin, prazosin, terazosin). The β-adrenergic blocker (ie, propranolol, metoprolol) should be started cautiously with a low dose and slowly titrated to control heart rate. A high sodium diet and increased fluid intake also are recommended 7 to 14 days before surgery. A sudden drop in catecholamines can cause hypotension during an operation. Continuous fluid infusions are given to prevent hypotension.22 Similarly, anesthetic agents also should be modified to prevent cardiotoxic effects. Rocuronium and vecuronium are less cardiotoxic compared with other sympathomimetic muscle relaxants. Short-acting anesthetic agents, such as fentanyl, are preferred. α-blockers are continued throughout the operation. Biochemical testing with fractionated metanephrines is performed about 1 to 2 weeks postoperatively to look for recurrence of the disease.23
Secondary causes of hypertension are suspected in multidrug resistant or sudden early onset of hypertension before aged 40 years. Pheochromocytoma is a rare cause of secondary hypertension, and older adult patients are rarely diagnosed with pheochromocytoma.24 In this report, pheochromocytoma was detected in a 72-year-old hypertensive patient. Therefore, a pheochromocytoma diagnosis should not be ignored in the older adult patient with adrenal mass and hypertension treated with more than one drug. The authors recommend any patient undergoing surgery with adrenal lesion should be considered for the screening of possible pheochromocytoma and prepared preoperatively, especially any patient with renal cell carcinoma with adrenal metastasis.
Conclusions
Asymptomatic pheochromocytoma is an unusual but serious condition, especially for patients undergoing a surgical procedure. An adrenal mass may be ignored in asymptomatic or mildly symptomatic older adult patients and is mostly considered as adrenal metastasis when present with other malignancies. Fortunately, the nephrectomy and adrenalectomy in our case of asymptomatic pheochromocytoma was uneventful, but pheochromocytoma should be ruled out before a surgical procedure, as an absence of medical pretreatment can lead to serious consequences. Therefore, we suggest a more careful screening of pheochromocytoma in patients with an adrenal mass (primary or metastatic) and hypertension treated with multiple antihypertensive drugs, even in older adult patients.
Pheochromocytoma is a rare catecholamine-secreting tumor of chromaffin cells of the adrenal medulla or sympathetic ganglia, occurring in about 0.2 to 0.5% of patients with hypertension.1-3 However, in a review of 54 autopsy-proven cases of pheochromocytoma, about 50% of the patients with hypertension were not clinically suspected for pheochromocytoma.4
Pheochromocytoma is usually diagnosed based on symptoms of hyperadrenergic spells, resistant hypertension, especially in the young, with a pressor response to the anesthesia stress test and adrenal incidentaloma.
The classic triad of symptoms associated with pheochromocytoma includes episodic headache (90%), sweating (60-70%), and palpitations (70%).2,5 Sustained or paroxysmal hypertension is the most common symptom reported in about 95% of patients with pheochromocytoma. Other symptoms include pallor, tremors, dyspnea, generalized weakness, orthostatic hypotension, cardiomyopathy, or hyperglycemia.6 However, about 10% of patients with pheochromocytoma are asymptomatic or mildly symptomatic.7 Secondary causes of hypertension are usually suspected in multidrug resistant or sudden early onset of hypertension.8
Approximately 10% of catecholamine-secreting tumors are malignant.9-11 Benign and malignant pheochromocytoma have a similar biochemical and histologic presentation and are differentiated based on local invasion into the surrounding tissues and organs (eg, kidney, liver) or distant metastasis.
A typical workup of a suspected patient with pheochromocytoma includes biochemical tests, including measurements of urinary and fractionated plasma metanephrines and catecholamine. Patients with positive biochemical tests should undergo localization of the tumor with an imaging study either with an adrenal/abdominal magnetic resonance imaging (MRI) or computed tomography (CT) scan. If a patient has paraganglioma or an adrenal mass > 10 cm or negative abdominal imaging with a positive biochemical test, further imaging with an iobenguane I-123 scan is needed (Figure 1).
In this article, we present an unusual case of asymptomatic pheochromocytoma in a patient with right-sided renal oncocytoma who underwent an uneventful nephrectomy and adrenalectomy.
Case Presentation
A 72-year-old male with a medical history of diabetes, hypertension, sensory neuropathy, benign prostatic hypertrophy (BPH) status posttransurethral resection of the prostate, and chronic renal failure presented to establish care with the Arizona Kidney Disease and Hypertension Center. His medications included losartan 50 mg by mouth daily, diltiazem 180 mg extended-release by mouth daily, carvedilol 6.25 mg by mouth twice a day, and tamsulosin 0.4 mg by mouth daily. His presenting vitals were blood pressure (BP), 112/74 left arm sitting, pulse, 63/beats per min, and body mass index, 34. On physical examination, the patient was alert and oriented, and the chest was clear to auscultation without wheeze or rhonchi. On cardiac examination, heart rate and rhythm were regular; S1 and S2 were normal with no added murmurs, rubs or gallops, and no jugular venous distension. The abdomen was soft, nontender, with no palpable mass. His laboratory results showed sodium, 142 mmol/L; potassium, 5.3 mmol/L; chloride, 101 mmol/L; carbon dioxide, 24 mmol/L; albumin, 4.3 g/dL; creatinine, 1.89 mg/dL; blood urea nitrogen, 29 mg/dL; estimated glomerular filtration rate non-African American, 35 mL/min/1.73; 24-h urine creatinine clearance, 105 mL/min; protein, 1306 mg/24 h (Table).
His renal ultrasound showed an exophytic isoechoic mass or complex cyst at the lateral aspect of the lower pole of the right kidney, measuring 45 mm in diameter. An MRI of the abdomen with and without contrast showed a solid partially exophytic mass of the posterolateral interpolar cortex of the right kidney, measuring 5.9 cm in the greatest dimension (Figure 2). No definite involvement of Gerota fascia was noted, a 1-cm metastasis to the right adrenal gland was present, renal veins were patent, and there was no upper retroperitoneal lymphadenopathy.
Treatment and Follow-up
The patient underwent right-hand-assisted lap-aroscopic radical nephrectomy and right adre-nalectomy without any complications. However, the surgical pathology report showed oncocytoma of the kidney (5.7 cm), pheochromocytoma of the adrenal gland (1.4 cm), and papillary adenoma of the kidney (0.7 cm). Right kidney nephrectomy showed non-neoplastic renal parenchyma, diabetic glomerulosclerosis (Renal Pathology Society 2010 diabetic nephropathy class IIb), severe mesangial expansion, moderate interstitial fibrosis, moderate arteriosclerosis, and mild arteriolosclerosis.
A fluorodeoxyglucose-positron emission tomography (FDG-PET) scan was significant for right nephrectomy and adrenalectomy and showed no significant evidence of residual neoplasm or local or distant metastases. A nuclear medicine (iobenguane I-123) tumor and single positron emission computed tomography (SPECT) scan showed normal activity throughout the body and no evidence of abnormal activity (Figure 3).
Discussion
Pheochromocytoma is a rare cause of secondary hypertension. However, the real numbers are thought to be > 0.2 to 0.5%.1,2,4 Patients with pheochromocytoma should undergo surgical adrenal resection after appropriate medical preparation. Patients with pheochromocytoma who are not diagnosed preoperatively have increased surgical mortality rates due to fatal hypertensive crises, malignant arrhythmia, and multiorgan failure as a result of hypertensive crisis.15 Anesthetic drugs during surgery also can exacerbate the cardiotoxic effects of catecholamines. Short-acting anesthetic agents, such as fentanyl, are used in patients with pheochromocytoma.16
This case of pheochromocytoma illustrated no classic symptoms of episodic headache, sweating, and tachycardia, and the patient was otherwise asymptomatic. BP was well controlled with losartan, diltiazem, and a β-blocker with α-blocking activity (carvedilol). As the patient was not known to have pheochromocytoma, he did not undergo preoperative medical therapy. Figure 4 illustrates the receptors stimulate catecholamines, and the drugs blocking these receptors prevent hypertensive crisis during surgery. However, the surgery was without potential complications (ie, hypertensive crisis, malignant arrhythmia, or multiorgan failure). The patient was diagnosed incidentally on histopathology after right radical nephrectomy and adrenalectomy due to solid partially exophytic right renal mass (5.9 cm) with right adrenal metastasis. About 10% of patients are asymptomatic or mildly symptomatic.7 Sometimes, the symptoms may be ignored because of the episodic nature. Other possible reasons can be small, nonfunctional tumors or the use of antihypertensive medications suppressing the symptoms.7
The adrenal mass that was initially thought to be a metastasis of right kidney mass was later confirmed as pheochromocytoma. One possible explanation for uneventful surgery could be the use of β-blocker with α-blocking activity (carvedilol), α-1 adrenergic blocker (tamsulosin) along with nondihydropyridine calcium channel blocker (diltiazem) as part of the patient’s antihypertensive and BPH medication regimen. Another possible explanation could be silent or episodically secreting pheochromocytoma with a small functional portion.
Subsequent workup after adrenalectomy, including urinary and fractionated plasma metanephrines and catecholamines, were not consistent with catecholamine hypersecretion. A 24-hour urine fractionated metanephrines test has about 98% sensitivity and 98% specificity. Elevated plasma norepinephrine was thought to be due to renal failure because it was < 3-fold the upper limit of normal, which is considered to be a possible indication of pheochromocytoma.17,18 The nuclear medicine (iobenguane I-123) tumor, SPECT, and FDG-PET CT studies were negative for residual pheochromocytoma. Other imaging studies to consider in patients with suspected catecholamine-secreting tumor with positive biochemical test and negative abdominal imaging are a whole-body MRI scan, 68-Ga DOTATATE (gallium 68 1,4,7,10-tetraazacyclododecane-1,4,7,10 tetraacetic acid-octreotate) or FDG-PET scan.19
In a review of 54 autopsy-proven pheochromocytoma cases by Sutton and colleagues in 1981, 74% of the patients were not clinically suspected for pheochromocytoma in their life.4 Similarly, in a retrospective study of hospital autopsies by McNeil and colleagues, one incidental pheochromocytoma was detected in every 2031 autopsies (0.05%).20 In another case series of 41 patients with pheochromocytoma-related adrenalectomy, almost 50% of the pheochromocytomas were detected incidentally on imaging studies.21 Although the number of incidental findings are decreasing due to advances in screening techniques, a significant number of patients remain undiagnosed. Multiple cases of diagnosis of pheochromocytoma on autopsy of patients who died of hemodynamic instability (ie, hypertensive crisis, hypotension crisis precipitated by surgery for adrenal or nonadrenal conditions) are reported.3 To the best of our knowledge, there are no case reports published on the diagnosis of pheochromocytoma after adrenalectomy in an asymptomatic patient without intraoperative complications.
The goal of preoperative medical therapy includes BP control, prevention of tachycardia, and volume expansion. The preoperative medications regimens are combined α- and β-adrenergic blockade, calcium channel blockers, and metyrosine. According to clinical practice guidelines of the Endocrine Society in 2014, the α-adrenergic blockers should be started first at least 7 days before surgery to control BP and to cause vasodilation. Early use of α-blockers is required to prevent cardiotoxicity. The β-adrenergic blockers should be started after the adequate α-adrenergic blockade, typically 2 to 3 days before surgery, as early use can cause vasoconstriction in patients with pheochromocytoma. The α-adrenergic blockers include phenoxybenzamine (nonselective long-acting nonspecific α-adrenergic blocking agent), and selective α-1 adrenergic blockers (doxazosin, prazosin, terazosin). The β-adrenergic blocker (ie, propranolol, metoprolol) should be started cautiously with a low dose and slowly titrated to control heart rate. A high sodium diet and increased fluid intake also are recommended 7 to 14 days before surgery. A sudden drop in catecholamines can cause hypotension during an operation. Continuous fluid infusions are given to prevent hypotension.22 Similarly, anesthetic agents also should be modified to prevent cardiotoxic effects. Rocuronium and vecuronium are less cardiotoxic compared with other sympathomimetic muscle relaxants. Short-acting anesthetic agents, such as fentanyl, are preferred. α-blockers are continued throughout the operation. Biochemical testing with fractionated metanephrines is performed about 1 to 2 weeks postoperatively to look for recurrence of the disease.23
Secondary causes of hypertension are suspected in multidrug resistant or sudden early onset of hypertension before aged 40 years. Pheochromocytoma is a rare cause of secondary hypertension, and older adult patients are rarely diagnosed with pheochromocytoma.24 In this report, pheochromocytoma was detected in a 72-year-old hypertensive patient. Therefore, a pheochromocytoma diagnosis should not be ignored in the older adult patient with adrenal mass and hypertension treated with more than one drug. The authors recommend any patient undergoing surgery with adrenal lesion should be considered for the screening of possible pheochromocytoma and prepared preoperatively, especially any patient with renal cell carcinoma with adrenal metastasis.
Conclusions
Asymptomatic pheochromocytoma is an unusual but serious condition, especially for patients undergoing a surgical procedure. An adrenal mass may be ignored in asymptomatic or mildly symptomatic older adult patients and is mostly considered as adrenal metastasis when present with other malignancies. Fortunately, the nephrectomy and adrenalectomy in our case of asymptomatic pheochromocytoma was uneventful, but pheochromocytoma should be ruled out before a surgical procedure, as an absence of medical pretreatment can lead to serious consequences. Therefore, we suggest a more careful screening of pheochromocytoma in patients with an adrenal mass (primary or metastatic) and hypertension treated with multiple antihypertensive drugs, even in older adult patients.
1. Omura M, Saito J, Yamaguchi K, Kakuta Y, Nishikawa T. Prospective study on the prevalence of secondary hypertension among hypertensive patients visiting a general outpatient clinic in Japan. Hypertens Res. 2004;27(3):193-202. doi:10.1291/hypres.27.193
2. Stein PP, Black HR. A simplified diagnostic approach to pheochromocytoma: a review of the literature and report of one institution’s experience. Medicine (Baltimore). 1991;70(1):46-66. doi:10.1097/00005792-199101000-00004
3. Beard CM, Sheps SG, Kurland LT, Carney JA, Lie JT. Occurrence of pheochromocytoma in Rochester, Minnesota, 1950 through 1979. Mayo Clin Proc. 1983;58(12):802-804.
4. Sutton MG, Sheps SG, Lie JT. Prevalence of clinically unsuspected pheochromocytoma: review of a 50-year autopsy series. Mayo Clin Proc. 1981;56(6):354-360.
5. Manger WM, Gifford RW Jr. Pheochromocytoma. J Clin Hypertens (Greenwich). 2002;4(1):62-72. doi:10.1111/j.1524-6175.2002.01452.x
6. Kassim TA, Clarke DD, Mai VQ, Clyde PW, Mohamed Shakir KM. Catecholamine-induced cardiomyopathy. Endocr Pract. 2008;14(9):1137-1149. doi:10.4158/EP.14.9.1137
7. Kudva YC, Young WF, Thompson GB, Grant CS, Van Heerden JA. Adrenal incidentaloma: an important component of the clinical presentation spectrum of benign sporadic adrenal pheochromocytoma. The Endocrinologist. 1999;9(2):77-80. doi:10.1097/00019616-199903000-00002
8. Puar TH, Mok Y, Debajyoti R, Khoo J, How CH, Ng AK. Secondary hypertension in adults. Singapore Med J. 2016;57(5):228-232. doi:10.11622/smedj.2016087
9. Bravo EL. Pheochromocytoma: new concepts and future trends. Kidney Int. 1991;40(3):544-556. doi:10.1038/ki.1991.244
10. Plouin PF, Chatellier G, Fofol I, Corvol P. Tumor recurrence and hypertension persistence after successful pheochromocytoma operation. Hypertension. 1997;29(5):1133-1139. doi:10.1161/01.hyp.29.5.1133
11. Hamidi O, Young WF Jr, Iñiguez-Ariza NM, et al. Malignant pheochromocytoma and paraganglioma: 272 patients over 55 years. J Clin Endocrinol Metab. 2017;102(9):3296-3305. doi:10.1210/jc.2017-00992
12. Kenny L, Rizzo V, Trevis J, Assimakopoulou E, Timon D. The unexpected diagnosis of phaeochromocytoma in the anaesthetic room. Ann Card Anaesth. 2018;21(3):307-310. doi:10.4103/aca.ACA_206_17
13. Johnston PC, Silversides JA, Wallace H, et al. Phaeochromocytoma crisis: two cases of undiagnosed phaeochromocytoma presenting after elective nonrelated surgical procedures. Case Rep Anesthesiol. 2013;2013:514714. doi:10.1155/2013/514714
14. Shen SJ, Cheng HM, Chiu AW, Chou CW, Chen JY. Perioperative hypertensive crisis in clinically silent pheochromocytomas: report of four cases. Chang Gung Med J. 2005;28(1):44-50.
15. Lo CY, Lam KY, Wat MS, Lam KS. Adrenal pheochromocytoma remains a frequently overlooked diagnosis. Am J Surg. 2000;179(3):212-215. doi:10.1016/s0002-9610(00)00296-8
16. Myklejord DJ. Undiagnosed pheochromocytoma: the anesthesiologist nightmare. Clin Med Res. 2004;2(1):59-62. doi:10.3121/cmr.2.1.59
17. Stumvoll M, Radjaipour M, Seif F. Diagnostic considerations in pheochromocytoma and chronic hemodialysis: case report and review of the literature. Am J Nephrol. 1995;15(2):147-151. doi:10.1159/000168820
18. Morioka M, Yuihama S, Nakajima T, et al. Incidentally discovered pheochromocytoma in long-term hemodialysis patients. Int J Urol. 2002;9(12):700-703. doi:10.1046/j.1442-2042.2002.00553.x
19. ˇCtvrtlík F, Koranda P, Schovánek J, Škarda J, Hartmann I, Tüdös Z. Current diagnostic imaging of pheochromocytomas and implications for therapeutic strategy. Exp Ther Med. 2018;15(4):3151-3160. doi:10.3892/etm.2018.5871
20. McNeil AR, Blok BH, Koelmeyer TD, Burke MP, Hilton JM. Phaeochromocytomas discovered during coronial autopsies in Sydney, Melbourne and Auckland. Aust N Z J Med. 2000;30(6):648-652. doi:10.1111/j.1445-5994.2000.tb04358.x
21. Baguet JP, Hammer L, Mazzuco TL, et al. Circumstances of discovery of phaeochromocytoma: a retrospective study of 41 consecutive patients. Eur J Endocrinol. 2004;150(5):681-686. doi:10.1530/eje.0.1500681
22. Lenders JW, Duh QY, Eisenhofer G, et al. Pheochromocytoma and paraganglioma: an endocrine society clinical practice guideline. J Clin Endocrinol Metab. 2014;99(6):1915-1942. doi:10.1210/jc.2014-1498
23. Dortzbach K, Gainsburg DM, Frost EA. Variants of pheochromocytoma and their anesthetic implications--a case report and literature review. Middle East J Anaesthesiol. 2010;20(6):897-905.
24. Januszewicz W, Chodakowska J, Styczy´nski G. Secondary hypertension in the elderly. J Hum Hypertens. 1998;12(9):603-606. doi:10.1038/sj.jhh.1000673
1. Omura M, Saito J, Yamaguchi K, Kakuta Y, Nishikawa T. Prospective study on the prevalence of secondary hypertension among hypertensive patients visiting a general outpatient clinic in Japan. Hypertens Res. 2004;27(3):193-202. doi:10.1291/hypres.27.193
2. Stein PP, Black HR. A simplified diagnostic approach to pheochromocytoma: a review of the literature and report of one institution’s experience. Medicine (Baltimore). 1991;70(1):46-66. doi:10.1097/00005792-199101000-00004
3. Beard CM, Sheps SG, Kurland LT, Carney JA, Lie JT. Occurrence of pheochromocytoma in Rochester, Minnesota, 1950 through 1979. Mayo Clin Proc. 1983;58(12):802-804.
4. Sutton MG, Sheps SG, Lie JT. Prevalence of clinically unsuspected pheochromocytoma: review of a 50-year autopsy series. Mayo Clin Proc. 1981;56(6):354-360.
5. Manger WM, Gifford RW Jr. Pheochromocytoma. J Clin Hypertens (Greenwich). 2002;4(1):62-72. doi:10.1111/j.1524-6175.2002.01452.x
6. Kassim TA, Clarke DD, Mai VQ, Clyde PW, Mohamed Shakir KM. Catecholamine-induced cardiomyopathy. Endocr Pract. 2008;14(9):1137-1149. doi:10.4158/EP.14.9.1137
7. Kudva YC, Young WF, Thompson GB, Grant CS, Van Heerden JA. Adrenal incidentaloma: an important component of the clinical presentation spectrum of benign sporadic adrenal pheochromocytoma. The Endocrinologist. 1999;9(2):77-80. doi:10.1097/00019616-199903000-00002
8. Puar TH, Mok Y, Debajyoti R, Khoo J, How CH, Ng AK. Secondary hypertension in adults. Singapore Med J. 2016;57(5):228-232. doi:10.11622/smedj.2016087
9. Bravo EL. Pheochromocytoma: new concepts and future trends. Kidney Int. 1991;40(3):544-556. doi:10.1038/ki.1991.244
10. Plouin PF, Chatellier G, Fofol I, Corvol P. Tumor recurrence and hypertension persistence after successful pheochromocytoma operation. Hypertension. 1997;29(5):1133-1139. doi:10.1161/01.hyp.29.5.1133
11. Hamidi O, Young WF Jr, Iñiguez-Ariza NM, et al. Malignant pheochromocytoma and paraganglioma: 272 patients over 55 years. J Clin Endocrinol Metab. 2017;102(9):3296-3305. doi:10.1210/jc.2017-00992
12. Kenny L, Rizzo V, Trevis J, Assimakopoulou E, Timon D. The unexpected diagnosis of phaeochromocytoma in the anaesthetic room. Ann Card Anaesth. 2018;21(3):307-310. doi:10.4103/aca.ACA_206_17
13. Johnston PC, Silversides JA, Wallace H, et al. Phaeochromocytoma crisis: two cases of undiagnosed phaeochromocytoma presenting after elective nonrelated surgical procedures. Case Rep Anesthesiol. 2013;2013:514714. doi:10.1155/2013/514714
14. Shen SJ, Cheng HM, Chiu AW, Chou CW, Chen JY. Perioperative hypertensive crisis in clinically silent pheochromocytomas: report of four cases. Chang Gung Med J. 2005;28(1):44-50.
15. Lo CY, Lam KY, Wat MS, Lam KS. Adrenal pheochromocytoma remains a frequently overlooked diagnosis. Am J Surg. 2000;179(3):212-215. doi:10.1016/s0002-9610(00)00296-8
16. Myklejord DJ. Undiagnosed pheochromocytoma: the anesthesiologist nightmare. Clin Med Res. 2004;2(1):59-62. doi:10.3121/cmr.2.1.59
17. Stumvoll M, Radjaipour M, Seif F. Diagnostic considerations in pheochromocytoma and chronic hemodialysis: case report and review of the literature. Am J Nephrol. 1995;15(2):147-151. doi:10.1159/000168820
18. Morioka M, Yuihama S, Nakajima T, et al. Incidentally discovered pheochromocytoma in long-term hemodialysis patients. Int J Urol. 2002;9(12):700-703. doi:10.1046/j.1442-2042.2002.00553.x
19. ˇCtvrtlík F, Koranda P, Schovánek J, Škarda J, Hartmann I, Tüdös Z. Current diagnostic imaging of pheochromocytomas and implications for therapeutic strategy. Exp Ther Med. 2018;15(4):3151-3160. doi:10.3892/etm.2018.5871
20. McNeil AR, Blok BH, Koelmeyer TD, Burke MP, Hilton JM. Phaeochromocytomas discovered during coronial autopsies in Sydney, Melbourne and Auckland. Aust N Z J Med. 2000;30(6):648-652. doi:10.1111/j.1445-5994.2000.tb04358.x
21. Baguet JP, Hammer L, Mazzuco TL, et al. Circumstances of discovery of phaeochromocytoma: a retrospective study of 41 consecutive patients. Eur J Endocrinol. 2004;150(5):681-686. doi:10.1530/eje.0.1500681
22. Lenders JW, Duh QY, Eisenhofer G, et al. Pheochromocytoma and paraganglioma: an endocrine society clinical practice guideline. J Clin Endocrinol Metab. 2014;99(6):1915-1942. doi:10.1210/jc.2014-1498
23. Dortzbach K, Gainsburg DM, Frost EA. Variants of pheochromocytoma and their anesthetic implications--a case report and literature review. Middle East J Anaesthesiol. 2010;20(6):897-905.
24. Januszewicz W, Chodakowska J, Styczy´nski G. Secondary hypertension in the elderly. J Hum Hypertens. 1998;12(9):603-606. doi:10.1038/sj.jhh.1000673
Cisplatin-Induced Acute Kidney Injury and Renal Salt Wasting Syndrome
A treatment strategy that incorporates both water restrictions and sodium supplementation may be appropriate when differentiating between diagnoses of renal salt wasting syndrome and syndrome of inappropriate antidiuretic hormone secretion.
Cisplatin is a potent antineoplastic agent derived from platinum and commonly used in the treatment of head and neck, bladder, ovarian, and testicular malignancies.1,2 Approximately 20% of all cancer patients are prescribed platinum-based chemotherapeutics.3 Although considered highly effective, cisplatin is also a dose-dependent nephrotoxin, inducing apoptosis in the proximal tubules of the nephron and reducing glomerular filtration rate. This nephron injury leads to inflammation and reduced medullary blood flow, causing further ischemic damage to the tubular cells.4 Given that the proximal tubule reabsorbs 67% of all sodium, cisplatin-induced nephron injuries can also lead to hyponatremia.5
The primary mechanisms of hyponatremia following cisplatin chemotherapy are syndrome of inappropriate antidiuretic hormone secretion (SIADH) and renal salt wasting syndrome (RSWS). Though these diagnoses have similar presentations, the treatment recommendations are different due to pathophysiologic differences. Fluid restriction is the hallmark of SIADH treatment, while increased sodium intake remains the hallmark of RSWS treatment.6 This patient presented with a combination of cisplatin-induced acute kidney injury (AKI) and hyponatremia secondary to RSWS. While RSWS and AKI are known complications of cisplatin chemotherapy, the combination is underreported in the literature. Therefore, this case report highlights the combination of these cisplatin-induced complications, emphasizes the clinical challenges in differentiating SIADH from RSWS, especially in the presence of a concomitant AKI, and suggests a treatment approach during diagnostic uncertainty.
Case Presentation
A 71-year-old man with a medical history of squamous cell carcinoma (SCC) of the left neck on cycle 1, day 8 of cisplatin-based chemotherapy and ongoing radiation therapy (720 cGy of 6300 cGy), lung adenocarcinoma status postresection, and hyperlipidemia presented to the emergency department (ED) at the request of his oncologist for abnormal laboratory values. In the ED, his metabolic panel showed a 131-mmol/L serum sodium, 3.3 mmol/L potassium, 83 mmol/L chloride, 29 mmol/L bicarbonate, 61 mg/dL blood urea nitrogen (BUN), and 8.8 mg/dL creatinine (baseline, 0.9 mg/dL). The patient reported throbbing headaches, persistent nausea, and multiple episodes of nonbloody emesis for several days that he attributed to his chemotherapy. He noted decreased urination without discomfort or changes in color or odor and no fatigue, fevers, chills, hematuria, flank, abdominal pain, thirst, or polydipsia. He reported no toxic ingestions or IV drug use. The patient had no relevant family history or additional social history. His outpatient medications included 10 mg cetirizine, 8 mg ondansetron, and 81 mg aspirin. On initial examination, his 137/66 mm Hg blood pressure was mildly elevated. The physical examination findings were notable for a 5-cm mass in the left neck that was firm and irregularly-shaped. His physical examination was otherwise unremarkable. He was admitted to the inpatient medicine service for an AKI complicated by symptomatic hyponatremia.
Investigations
We evaluated the patient’s AKI based on treatment responsiveness, imaging, and laboratory testing. Renal and bladder ultrasound showed no evidence of hydronephrosis or obstruction. He had a benign urinalysis with microscopy absent for protein, blood, ketones, leukocyte esterase, nitrites, and cellular casts. His urine pH was 5.5 (reference range, 5.0-9.0) and specific gravity was 1.011 (reference range, 1.005-1.030). His urine electrolytes revealed 45-mmol/L urine sodium (reference range, 40-220), 33-mmol/L urine chloride (reference range, 110-250), 10-mmol/L urine potassium (reference range, 25-120), 106.7-mg/dL urine creatinine (reference range, 10-400) and a calculated 2.7% fractional excretion of sodium (FENa) and 22.0-mEq/L elevated urine anion gap. As a fluid challenge, he was treated with IV 0.9% sodium chloride at 100-125 mL/h, receiving 3 liters over the first 48 hours of his hospitalization. His creatinine peaked at 9.2 mg/dL and stabilized before improving later in his hospitalization (Figure 1). The patient initially had oliguria (< 0.5 mL/kg/h), which slowly improved over his hospital course. Unfortunately, due to multiple system and clinical factors, accurate inputs and outputs were not adequately maintained during his hospitalization.
We evaluated hyponatremia with a combination of serum and urine laboratory tests. In addition to urine electrolytes, the initial evaluation focused on trending his clinical trajectory. We repeated a basic metabolic panel every 4 to 6 hours. He had 278-mOsm/kg serum osmolality (reference range, 285-295) with an effective 217-mOsm/kg serum tonicity. His urine osmolality was 270.5 mOsm/kg.
Despite administering 462 mEq sodium via crystalloid, his sodium worsened over the first 48 hours, reaching a nadir at 125 mmol/L on hospital day 3 (Figure 2). While he continued to appear euvolemic on physical examination, his blood pressure became difficult to control with 160- to 180-mm Hg systolic blood pressure readings. His thyroid stimulating hormone (TSH) was normal and aldosterone was low (4 ng/dL). Additional urine studies, including a 24-hour urine sample, were collected for further evaluation. His urine uric acid was 140 mg/d (reference range, 120-820); his serum uric acid level was 8.2 mg/dL (reference range, 3.0-9.0). His 24-hour urine creatinine was 0.57 g/d (reference range, 0.50-2.15) and uric acid to creatinine ratio was 246 mg/g (reference range, 60-580). His serum creatinine collected from the same day as his 24-hour urine sample was 7.3 mg/dL. His fractional excretion of uric acid (FEurate) was 21.9%.
Differential Diagnosis
The patient’s recent administration of cisplatin raised clinical suspicion of cisplatin-induced AKI. To avoid premature diagnostic closure, we used a systematic approach for thinking about our patient’s AKI, considering prerenal, intrarenal, and postrenal etiologies. The unremarkable renal and bladder ultrasound made a postrenal etiology unlikely. The patient’s 2.7% FENa in the absence of a diuretic, limited responsiveness to crystalloid fluid resuscitation, 7.5 serum BUN/creatinine ratio, and 270.5 mOsm/kg urine osmolality suggested an intrarenal etiology, which can be further divided into problems with glomeruli, tubules, small vessels, or interstitial space. The patient’s normal urinary microscopy with no evidence of protein, blood, ketones, leukocyte esterase, nitrites, or cellular casts made a glomerular etiology less likely. The acute onset and lack of additional systemic features, other than hypertension, made a vascular etiology less likely. A tubular etiology, such as acute tubular necrosis (ATN), was highest on the differential and was followed by an interstitial etiology, such as acute interstitial nephritis (AIN).
Patients with drug-induced AIN commonly present with signs and symptoms of an allergic-type reaction, including fever, rash, hematuria, pyuria, and costovertebral angle tenderness. The patient lacked these symptoms. However, cisplatin is known to cause ATN in up to 20-30% of patients.7 Therefore, despite the lack of the classic muddy-brown, granular casts on urine microscopy, cisplatin-induced ATN remained the most likely etiology of his AKI. Moreover, ATN can cause hyponatremia. ATN is characterized by 3 phases: initiation, maintenance, and recovery phases.8 Hyponatremia occurs during the recovery phase, typically starting weeks after renal insult and associated with high urine output and diuresis. This patient presented 1 week after injury and had persistent oliguria, making ATN an unlikely culprit of his hyponatremia.
Our patient presented with hypotonic hyponatremia with a 131 mmol/L initial sodium level and an < 280 mOsm/kg effective serum osmolality, or serum tonicity. The serum tonicity is equivalent to the difference between the measured serum osmolality and the BUN. In the setting of profound AKI, this adjustment is essential for correctly categorizing a patient’s hyponatremia as hyper-, iso-, or hypotonic. The differential diagnosis for this patient’s hypotonic hyponatremia included dilutional effects of hypervolemia, SIADH, hyperthyroidism, adrenal insufficiency, and RSWS. The patient’s volume examination, lack of predisposing comorbidities or suggestive biomarkers, and > 20 mmol/L urinary sodium made hypervolemia unlikely. His urinary osmolality and specific gravity made primary polydipsia unlikely. We worked up his hyponatremia according to a diagnostic algorithm (eAppendix available at doi:10.12788/fp.0198).
The patient had a 217 mOsm/kg serum tonicity and a 270.5 mOsm/kg urine osmolality, consistent with impaired water excretion. His presentation, TSH, and concordant decrease in sodium and potassium made an endocrine etiology of his hyponatremia less likely. In hindsight, a serum cortisol would have been beneficial to more completely exclude adrenal insufficiency. His urine sodium was elevated at 45 mmol/L, raising concern for RSWS or SIADH. The FEurate helped to distinguish between SIADH and RSWS. While FEurate is often elevated in both SIADH and RSWS initially, the FEurate normalizes in SIADH with normalization of the serum sodium. The ideal cutoff for posthyponatremia correction FEurate is debated; however, a FEurate value after sodium correction < 11% suggests SIADH while a value > 11% suggests RSWS.9 Our patient’s FEurate following the sodium correction (serum sodium 134 mmol/L) was 21.9%, most suggestive of RSWS.
Treatment
Upon admission, initial treatment focused on resolving the patient’s AKI. The oncology team discontinued the cisplatin-based chemotherapy. His medication dosages were adjusted for his renal function and additional nephrotoxins avoided. In consultation, the nephrology service recommended 100 mL/h fluid resuscitation. After the patient received 3 L of 0.9% sodium chloride, his creatinine showed limited improvement and his sodium worsened, trending from 131 mmol/L to a nadir of 125 mmol/L. We initiated oral free-water restriction while continuing IV infusion of 0.9% sodium chloride at 125 mL/h.
We further augmented his sodium intake with 1-g sodium chloride tablets with each meal. By hospital day 6, the patient’s serum sodium, BUN, and creatinine improved to 130 mEq/L, 50 mg/dL, and 7.7 mg/dL, respectively. We then discontinued the oral sodium chloride tablets, fluid restriction, and IV fluids in a stepwise fashion prior to discharge. At discharge, the patient’s serum sodium was 136 mEq/L and creatinine, 4.8 mg/dL. The patient’s clinical course was complicated by symptomatic hypertension with systolic blood pressures about 180 mm Hg, requiring intermittent IV hydralazine, which was transitioned to daily nifedipine. Concerned that fluid resuscitation contributed to his hypertension, the patient also received several doses of furosemide. At time of discharge, the patient remained hypertensive and was discharged with nifedipine 90 mg daily.
Outcome and Follow-up
The patient has remained stable clinically since discharge. One week after discharge, his serum sodium and creatinine were 138 mmol/L and 3.8 mg/dL, respectively. More than 1 month after discharge, his sodium remains in the reference range and his creatinine was stable at about 3.5 mg/dL. He continues to follow-up with nephrology, oncology, and radiation oncology. He has restarted chemotherapy with a carboplatin-based regimen without recurrence of hyponatremia or AKI. His blood pressure has gradually improved to the point where he no longer requires nifedipine.
Discussion
The US Food and Drug Administration first approved the use of cisplatin, an alkylating agent that inhibits DNA replication, in 1978 for the treatment of testicular cancer.10 Since its approval, cisplatin has increased in popularity and is now considered one of the most effective antineoplastic agents for the treatment of solid tumors.1 Unfortunately, cisplatin has a well-documented adverse effect profile that includes neurotoxicity, gastrointestinal toxicity, nephrotoxicity, and ototoxicity.4 Despite frequent nephrotoxicity, cisplatin only occasionally causes hyponatremia and rarely causes RSWS, a known but potentially fatal complication. Moreover, the combination of AKI and RSWS is unique. Our patient presented with the unique combination of AKI and hyponatremia, most consistent with RSWS, likely precipitated from cisplatin chemotherapy. Through this case, we review cisplatin-associated electrolyte abnormalities, highlight the challenge of differentiating SIADH and RSWS, and suggest a treatment approach for hyponatremia during the period of diagnostic uncertainty.
Blachley and colleagues first discussed renal and electrolyte disturbances, specifically magnesium wasting, secondary to cisplatin use in 1981. In 1984, Kurtzberg and colleagues noted salt wasting in 2 patients receiving cisplatin therapy. The authors suggested that cisplatin inhibits solute transport in the thick ascending limb, causing clinically significant electrolyte abnormalities, coining the term cisplatin-induced salt wasting.11
The prevalence of cisplatin-induced salt wasting is unclear and likely underreported. In 1988, Hutchinson and colleagues conducted a prospective cohort study and noted 10% of patients (n = 70) developed RSWS at some point over 18 months of cisplatin therapy—a higher rate than previously estimated.12 In 1992, another prospective cohort study evaluated the adverse effects of 47 patients with non-small cell lung cancer treated with cisplatin and reported hyponatremia in 43% of its 93 courses of chemotherapy. The authors did not report the etiology of these hyponatremia cases.13 Given the diagnostic challenge, RSWS may be underrepresented as a confirmed etiology of hyponatremia in cisplatin treatment.
Hyponatremia from cisplatin may present as either SIADH or RSWS, complicating treatment decisions. Both conditions lead to hypotonic hyponatremia with urine osmolality > 100 mOSm/kg and urine sodium levels > 40 mmol/L. However, pathophysiology behind SIADH and RSWS is different. In RSWS, proximal tubule damage causes hyponatremia, decreasing sodium reabsorption, and leading to impaired concentration gradient in every segment of the nephron. As a result, RSWS can lead to profound hyponatremia. Treatment typically consists of increasing sodium intake to correct serum sodium with salt tablets and hypertonic sodium chloride while treating the underlying etiology, in our case removing the offending agent, and waiting for proximal tubule function to recover.6 On the other hand, in SIADH, elevated antidiuretic hormone (ADH) increases water reabsorption in the collecting duct, which has no impact on concentration gradients of the other nephron segments.14 Free-water restriction is the hallmark of SIADH treatment. Severe SIADH may require sodium repletion and/or the initiation of vaptans, ADH antagonists that competitively inhibit V2 receptors in the collecting duct to prevent water reabsorption.15
Our patient had an uncertain etiology of his hyponatremia throughout most of his treatment course, complicating our treatment decision-making. Initially, his measured serum osmolality was 278 mOsm/kg; however, his effective tonicity was lower. His AKI elevated his BUN, which in turnrequired us to calculate his serum tonicity (217 mOsm/kg) that was consistent with hypotonic hyponatremia. His elevated urine osmolality and urine sodium levels made SIADH and RSWS the most likely etiologies of his hyponatremia. To confirm the etiology, we waited for correction of his serum sodium. Therefore, we treated him with a combination of sodium repletion with 0.9% sodium chloride (154 mEq/L), hypertonic relative to his serum sodium, sodium chloride tablets, and free-water restriction. In this approach, we attempted to harmonize the treatment strategies for both SIADH and RSWS and effectively corrected his serum sodium. We evaluated his response to our treatment with a basic metabolic panel every 6 to 8 hours. Had his serum sodium decreased < 120 mmol/L, we planned to transfer the patient to the intensive care unit for 3% sodium chloride and/or intensification of his fluid restriction. A significant worsening of his hyponatremia would have strongly suggested hyponatremia secondary to SIADH since isotonic saline can worsen hyponatremia due to increased free-water reabsorption in the collecting duct.16
To differentiate between SIADH and RSWS, we relied on the FEurate after sodium correction. Multiple case reports from Japan have characterized the distinction between the processes through FEurate and serum uric acid. While the optimal cut-off values for FEurate require additional investigation, values < 11% after serum sodium correction suggests SIADH, while a value > 11% suggests RSWS.17 Prior cases have also emphasized serum hypouricemia as a distinguishing characteristic in RSWS. However, our case illustrates that serum hypouricemia is less reliable in the setting of AKI. Due to his severe AKI, our patient could not efficiently clear uric acid, likely contributing to his hyperuricemia.
Ultimately, our patient had an FEurate > 20%, which was suggestive of RSWS. Nevertheless, we recognize limitations and confounders in our diagnosis and have reflected on our diagnostic and management choices. First, the sensitivity and specificity of postsodium correction FEurate is unknown. Tracking the change in FEurate with our interventions would have increased our diagnostic utility, as suggested by Maesaka and colleagues.14 Second, our patient’s serum sodium was still at the lower end of the reference range after treatment, which may decrease the specificity of FEurate. Third, a plasma ADH collected during the initial phase of symptomatic hyponatremia would have helped differentiate between SIADH and RSWS.
Other diagnostic tests that could have excluded alternative diagnoses with even greater certainty include plasma adrenocorticotropic hormone, B-type natriuretic peptide, renin, cortisol, and thyroid function tests. From a practical standpoint, these laboratory results (excluding thyroid function test and brain natriuretic peptide) would have taken several weeks to result at our institution, limiting their clinical utility. Similarly, FEurate also has limited clinical utility, requiring effective treatment as part of the diagnostic test. Therefore, we recommend focusing on optimal treatment for hyponatremia of uncertain etiology, especially where SIADH and RSWS are the leading diagnoses.
Conclusions
We described a rare case of concomitant cisplatin-induced severe AKI and RSWS. We have emphasized the diagnostic challenge of distinguishing between SIADH and RSWS, especially with concomitant AKI, and have acknowledged that optimal treatment relies on accurate differentiation. However, differentiation may not be clinically feasible. Therefore, we suggest a treatment strategy that incorporates both free-water restriction and sodium supplementation via IV and/or oral administration.
1. Dasari S, Tchounwou PB. Cisplatin in cancer therapy: molecular mechanisms of action. Eur J Pharmacol. 2014;740:364-378. doi:10.1016/j.ejphar.2014.07.025
2. Holditch SJ, Brown CN, Lombardi AM, Nguyen KN, Edelstein CL. Recent advances in models, mechanisms, biomarkers, and interventions in cisplatin-induced acute kidney injury. Int J Mol Sci. 2019;20(12):3011. Published 2019 Jun 20. doi:10.3390/ijms20123011
3. National Institutes of Health, National Cancer Institute. The “accidental” cure—platinum-based treatment for cancer: the discovery of cisplatin. Published May 30, 2014. Accessed November 10, 2021. https://www.cancer.gov/research/progress/discovery/cisplatin
4. Ozkok A, Edelstein CL. Pathophysiology of cisplatin-induced acute kidney injury. Biomed Res Int. 2014;2014:967826. doi:10.1155/2014/967826
5. Palmer LG, Schnermann J. Integrated control of Na transport along the nephron. Clin J Am Soc Nephrol. 2015;10(4):676-687. doi:10.2215/CJN.12391213
6. Bitew S, Imbriano L, Miyawaki N, Fishbane S, Maesaka JK. More on renal salt wasting without cerebral disease: response to saline infusion. Clin J Am Soc Nephrol. 2009;4(2):309-315. doi:10.2215/CJN.02740608
7. Shirali AC, Perazella MA. Tubulointerstitial injury associated with chemotherapeutic agents. Adv Chronic Kidney Dis. 2014;21(1):56-63. doi:10.1053/j.ackd.2013.06.010
8. Agrawal M, Swartz R. Acute renal failure [published correction appears in Am Fam Physician 2001 Feb 1;63(3):445]. Am Fam Physician. 2000;61(7):2077-2088.
9. Milionis HJ, Liamis GL, Elisaf MS. The hyponatremic patient: a systematic approach to laboratory diagnosis. CMAJ. 2002;166(8):1056-1062.
10. Monneret C. Platinum anticancer drugs. From serendipity to rational design. Ann Pharm Fr. 2011;69(6):286-295. doi:10.1016/j.pharma.2011.10.001
11. Kurtzberg J, Dennis VW, Kinney TR. Cisplatinum-induced renal salt wasting. Med Pediatr Oncol. 1984;12(2):150-154. doi:10.1002/mpo.2950120219
12. Hutchison FN, Perez EA, Gandara DR, Lawrence HJ, Kaysen GA. Renal salt wasting in patients treated with cisplatin. Ann Intern Med. 1988;108(1):21-25. doi:10.7326/0003-4819-108-1-21
13. Lee YK, Shin DM. Renal salt wasting in patients treated with high-dose cisplatin, etoposide, and mitomycin in patients with advanced non-small cell lung cancer. Korean J Intern Med. 1992;7(2):118-121. doi:10.3904/kjim.1992.7.2.118
14. Maesaka JK, Imbriano L, Mattana J, Gallagher D, Bade N, Sharif S. Differentiating SIADH from cerebral/renal salt wasting: failure of the volume approach and need for a new approach to hyponatremia. J Clin Med. 2014;3(4):1373-1385. Published 2014 Dec 8. doi:10.3390/jcm3041373
15. Palmer BF. The role of v2 receptor antagonists in the treatment of hyponatremia. Electrolyte Blood Press. 2013;11(1):1-8. doi:10.5049/EBP.2013.11.1.1
16. Verbalis JG, Goldsmith SR, Greenberg A, Schrier RW, Sterns RH. Hyponatremia treatment guidelines 2007: expert panel recommendations. Am J Med. 2007;120(11 Suppl 1):S1-S21. doi:10.1016/j.amjmed.2007.09.001
17. Maesaka JK, Imbriano LJ, Miyawaki N. High prevalence of renal salt wasting without cerebral disease as cause of hyponatremia in general medical wards. Am J Med Sci. 2018;356(1):15-22. doi:10.1016/j.amjms.2018.03.02
A treatment strategy that incorporates both water restrictions and sodium supplementation may be appropriate when differentiating between diagnoses of renal salt wasting syndrome and syndrome of inappropriate antidiuretic hormone secretion.
A treatment strategy that incorporates both water restrictions and sodium supplementation may be appropriate when differentiating between diagnoses of renal salt wasting syndrome and syndrome of inappropriate antidiuretic hormone secretion.
Cisplatin is a potent antineoplastic agent derived from platinum and commonly used in the treatment of head and neck, bladder, ovarian, and testicular malignancies.1,2 Approximately 20% of all cancer patients are prescribed platinum-based chemotherapeutics.3 Although considered highly effective, cisplatin is also a dose-dependent nephrotoxin, inducing apoptosis in the proximal tubules of the nephron and reducing glomerular filtration rate. This nephron injury leads to inflammation and reduced medullary blood flow, causing further ischemic damage to the tubular cells.4 Given that the proximal tubule reabsorbs 67% of all sodium, cisplatin-induced nephron injuries can also lead to hyponatremia.5
The primary mechanisms of hyponatremia following cisplatin chemotherapy are syndrome of inappropriate antidiuretic hormone secretion (SIADH) and renal salt wasting syndrome (RSWS). Though these diagnoses have similar presentations, the treatment recommendations are different due to pathophysiologic differences. Fluid restriction is the hallmark of SIADH treatment, while increased sodium intake remains the hallmark of RSWS treatment.6 This patient presented with a combination of cisplatin-induced acute kidney injury (AKI) and hyponatremia secondary to RSWS. While RSWS and AKI are known complications of cisplatin chemotherapy, the combination is underreported in the literature. Therefore, this case report highlights the combination of these cisplatin-induced complications, emphasizes the clinical challenges in differentiating SIADH from RSWS, especially in the presence of a concomitant AKI, and suggests a treatment approach during diagnostic uncertainty.
Case Presentation
A 71-year-old man with a medical history of squamous cell carcinoma (SCC) of the left neck on cycle 1, day 8 of cisplatin-based chemotherapy and ongoing radiation therapy (720 cGy of 6300 cGy), lung adenocarcinoma status postresection, and hyperlipidemia presented to the emergency department (ED) at the request of his oncologist for abnormal laboratory values. In the ED, his metabolic panel showed a 131-mmol/L serum sodium, 3.3 mmol/L potassium, 83 mmol/L chloride, 29 mmol/L bicarbonate, 61 mg/dL blood urea nitrogen (BUN), and 8.8 mg/dL creatinine (baseline, 0.9 mg/dL). The patient reported throbbing headaches, persistent nausea, and multiple episodes of nonbloody emesis for several days that he attributed to his chemotherapy. He noted decreased urination without discomfort or changes in color or odor and no fatigue, fevers, chills, hematuria, flank, abdominal pain, thirst, or polydipsia. He reported no toxic ingestions or IV drug use. The patient had no relevant family history or additional social history. His outpatient medications included 10 mg cetirizine, 8 mg ondansetron, and 81 mg aspirin. On initial examination, his 137/66 mm Hg blood pressure was mildly elevated. The physical examination findings were notable for a 5-cm mass in the left neck that was firm and irregularly-shaped. His physical examination was otherwise unremarkable. He was admitted to the inpatient medicine service for an AKI complicated by symptomatic hyponatremia.
Investigations
We evaluated the patient’s AKI based on treatment responsiveness, imaging, and laboratory testing. Renal and bladder ultrasound showed no evidence of hydronephrosis or obstruction. He had a benign urinalysis with microscopy absent for protein, blood, ketones, leukocyte esterase, nitrites, and cellular casts. His urine pH was 5.5 (reference range, 5.0-9.0) and specific gravity was 1.011 (reference range, 1.005-1.030). His urine electrolytes revealed 45-mmol/L urine sodium (reference range, 40-220), 33-mmol/L urine chloride (reference range, 110-250), 10-mmol/L urine potassium (reference range, 25-120), 106.7-mg/dL urine creatinine (reference range, 10-400) and a calculated 2.7% fractional excretion of sodium (FENa) and 22.0-mEq/L elevated urine anion gap. As a fluid challenge, he was treated with IV 0.9% sodium chloride at 100-125 mL/h, receiving 3 liters over the first 48 hours of his hospitalization. His creatinine peaked at 9.2 mg/dL and stabilized before improving later in his hospitalization (Figure 1). The patient initially had oliguria (< 0.5 mL/kg/h), which slowly improved over his hospital course. Unfortunately, due to multiple system and clinical factors, accurate inputs and outputs were not adequately maintained during his hospitalization.
We evaluated hyponatremia with a combination of serum and urine laboratory tests. In addition to urine electrolytes, the initial evaluation focused on trending his clinical trajectory. We repeated a basic metabolic panel every 4 to 6 hours. He had 278-mOsm/kg serum osmolality (reference range, 285-295) with an effective 217-mOsm/kg serum tonicity. His urine osmolality was 270.5 mOsm/kg.
Despite administering 462 mEq sodium via crystalloid, his sodium worsened over the first 48 hours, reaching a nadir at 125 mmol/L on hospital day 3 (Figure 2). While he continued to appear euvolemic on physical examination, his blood pressure became difficult to control with 160- to 180-mm Hg systolic blood pressure readings. His thyroid stimulating hormone (TSH) was normal and aldosterone was low (4 ng/dL). Additional urine studies, including a 24-hour urine sample, were collected for further evaluation. His urine uric acid was 140 mg/d (reference range, 120-820); his serum uric acid level was 8.2 mg/dL (reference range, 3.0-9.0). His 24-hour urine creatinine was 0.57 g/d (reference range, 0.50-2.15) and uric acid to creatinine ratio was 246 mg/g (reference range, 60-580). His serum creatinine collected from the same day as his 24-hour urine sample was 7.3 mg/dL. His fractional excretion of uric acid (FEurate) was 21.9%.
Differential Diagnosis
The patient’s recent administration of cisplatin raised clinical suspicion of cisplatin-induced AKI. To avoid premature diagnostic closure, we used a systematic approach for thinking about our patient’s AKI, considering prerenal, intrarenal, and postrenal etiologies. The unremarkable renal and bladder ultrasound made a postrenal etiology unlikely. The patient’s 2.7% FENa in the absence of a diuretic, limited responsiveness to crystalloid fluid resuscitation, 7.5 serum BUN/creatinine ratio, and 270.5 mOsm/kg urine osmolality suggested an intrarenal etiology, which can be further divided into problems with glomeruli, tubules, small vessels, or interstitial space. The patient’s normal urinary microscopy with no evidence of protein, blood, ketones, leukocyte esterase, nitrites, or cellular casts made a glomerular etiology less likely. The acute onset and lack of additional systemic features, other than hypertension, made a vascular etiology less likely. A tubular etiology, such as acute tubular necrosis (ATN), was highest on the differential and was followed by an interstitial etiology, such as acute interstitial nephritis (AIN).
Patients with drug-induced AIN commonly present with signs and symptoms of an allergic-type reaction, including fever, rash, hematuria, pyuria, and costovertebral angle tenderness. The patient lacked these symptoms. However, cisplatin is known to cause ATN in up to 20-30% of patients.7 Therefore, despite the lack of the classic muddy-brown, granular casts on urine microscopy, cisplatin-induced ATN remained the most likely etiology of his AKI. Moreover, ATN can cause hyponatremia. ATN is characterized by 3 phases: initiation, maintenance, and recovery phases.8 Hyponatremia occurs during the recovery phase, typically starting weeks after renal insult and associated with high urine output and diuresis. This patient presented 1 week after injury and had persistent oliguria, making ATN an unlikely culprit of his hyponatremia.
Our patient presented with hypotonic hyponatremia with a 131 mmol/L initial sodium level and an < 280 mOsm/kg effective serum osmolality, or serum tonicity. The serum tonicity is equivalent to the difference between the measured serum osmolality and the BUN. In the setting of profound AKI, this adjustment is essential for correctly categorizing a patient’s hyponatremia as hyper-, iso-, or hypotonic. The differential diagnosis for this patient’s hypotonic hyponatremia included dilutional effects of hypervolemia, SIADH, hyperthyroidism, adrenal insufficiency, and RSWS. The patient’s volume examination, lack of predisposing comorbidities or suggestive biomarkers, and > 20 mmol/L urinary sodium made hypervolemia unlikely. His urinary osmolality and specific gravity made primary polydipsia unlikely. We worked up his hyponatremia according to a diagnostic algorithm (eAppendix available at doi:10.12788/fp.0198).
The patient had a 217 mOsm/kg serum tonicity and a 270.5 mOsm/kg urine osmolality, consistent with impaired water excretion. His presentation, TSH, and concordant decrease in sodium and potassium made an endocrine etiology of his hyponatremia less likely. In hindsight, a serum cortisol would have been beneficial to more completely exclude adrenal insufficiency. His urine sodium was elevated at 45 mmol/L, raising concern for RSWS or SIADH. The FEurate helped to distinguish between SIADH and RSWS. While FEurate is often elevated in both SIADH and RSWS initially, the FEurate normalizes in SIADH with normalization of the serum sodium. The ideal cutoff for posthyponatremia correction FEurate is debated; however, a FEurate value after sodium correction < 11% suggests SIADH while a value > 11% suggests RSWS.9 Our patient’s FEurate following the sodium correction (serum sodium 134 mmol/L) was 21.9%, most suggestive of RSWS.
Treatment
Upon admission, initial treatment focused on resolving the patient’s AKI. The oncology team discontinued the cisplatin-based chemotherapy. His medication dosages were adjusted for his renal function and additional nephrotoxins avoided. In consultation, the nephrology service recommended 100 mL/h fluid resuscitation. After the patient received 3 L of 0.9% sodium chloride, his creatinine showed limited improvement and his sodium worsened, trending from 131 mmol/L to a nadir of 125 mmol/L. We initiated oral free-water restriction while continuing IV infusion of 0.9% sodium chloride at 125 mL/h.
We further augmented his sodium intake with 1-g sodium chloride tablets with each meal. By hospital day 6, the patient’s serum sodium, BUN, and creatinine improved to 130 mEq/L, 50 mg/dL, and 7.7 mg/dL, respectively. We then discontinued the oral sodium chloride tablets, fluid restriction, and IV fluids in a stepwise fashion prior to discharge. At discharge, the patient’s serum sodium was 136 mEq/L and creatinine, 4.8 mg/dL. The patient’s clinical course was complicated by symptomatic hypertension with systolic blood pressures about 180 mm Hg, requiring intermittent IV hydralazine, which was transitioned to daily nifedipine. Concerned that fluid resuscitation contributed to his hypertension, the patient also received several doses of furosemide. At time of discharge, the patient remained hypertensive and was discharged with nifedipine 90 mg daily.
Outcome and Follow-up
The patient has remained stable clinically since discharge. One week after discharge, his serum sodium and creatinine were 138 mmol/L and 3.8 mg/dL, respectively. More than 1 month after discharge, his sodium remains in the reference range and his creatinine was stable at about 3.5 mg/dL. He continues to follow-up with nephrology, oncology, and radiation oncology. He has restarted chemotherapy with a carboplatin-based regimen without recurrence of hyponatremia or AKI. His blood pressure has gradually improved to the point where he no longer requires nifedipine.
Discussion
The US Food and Drug Administration first approved the use of cisplatin, an alkylating agent that inhibits DNA replication, in 1978 for the treatment of testicular cancer.10 Since its approval, cisplatin has increased in popularity and is now considered one of the most effective antineoplastic agents for the treatment of solid tumors.1 Unfortunately, cisplatin has a well-documented adverse effect profile that includes neurotoxicity, gastrointestinal toxicity, nephrotoxicity, and ototoxicity.4 Despite frequent nephrotoxicity, cisplatin only occasionally causes hyponatremia and rarely causes RSWS, a known but potentially fatal complication. Moreover, the combination of AKI and RSWS is unique. Our patient presented with the unique combination of AKI and hyponatremia, most consistent with RSWS, likely precipitated from cisplatin chemotherapy. Through this case, we review cisplatin-associated electrolyte abnormalities, highlight the challenge of differentiating SIADH and RSWS, and suggest a treatment approach for hyponatremia during the period of diagnostic uncertainty.
Blachley and colleagues first discussed renal and electrolyte disturbances, specifically magnesium wasting, secondary to cisplatin use in 1981. In 1984, Kurtzberg and colleagues noted salt wasting in 2 patients receiving cisplatin therapy. The authors suggested that cisplatin inhibits solute transport in the thick ascending limb, causing clinically significant electrolyte abnormalities, coining the term cisplatin-induced salt wasting.11
The prevalence of cisplatin-induced salt wasting is unclear and likely underreported. In 1988, Hutchinson and colleagues conducted a prospective cohort study and noted 10% of patients (n = 70) developed RSWS at some point over 18 months of cisplatin therapy—a higher rate than previously estimated.12 In 1992, another prospective cohort study evaluated the adverse effects of 47 patients with non-small cell lung cancer treated with cisplatin and reported hyponatremia in 43% of its 93 courses of chemotherapy. The authors did not report the etiology of these hyponatremia cases.13 Given the diagnostic challenge, RSWS may be underrepresented as a confirmed etiology of hyponatremia in cisplatin treatment.
Hyponatremia from cisplatin may present as either SIADH or RSWS, complicating treatment decisions. Both conditions lead to hypotonic hyponatremia with urine osmolality > 100 mOSm/kg and urine sodium levels > 40 mmol/L. However, pathophysiology behind SIADH and RSWS is different. In RSWS, proximal tubule damage causes hyponatremia, decreasing sodium reabsorption, and leading to impaired concentration gradient in every segment of the nephron. As a result, RSWS can lead to profound hyponatremia. Treatment typically consists of increasing sodium intake to correct serum sodium with salt tablets and hypertonic sodium chloride while treating the underlying etiology, in our case removing the offending agent, and waiting for proximal tubule function to recover.6 On the other hand, in SIADH, elevated antidiuretic hormone (ADH) increases water reabsorption in the collecting duct, which has no impact on concentration gradients of the other nephron segments.14 Free-water restriction is the hallmark of SIADH treatment. Severe SIADH may require sodium repletion and/or the initiation of vaptans, ADH antagonists that competitively inhibit V2 receptors in the collecting duct to prevent water reabsorption.15
Our patient had an uncertain etiology of his hyponatremia throughout most of his treatment course, complicating our treatment decision-making. Initially, his measured serum osmolality was 278 mOsm/kg; however, his effective tonicity was lower. His AKI elevated his BUN, which in turnrequired us to calculate his serum tonicity (217 mOsm/kg) that was consistent with hypotonic hyponatremia. His elevated urine osmolality and urine sodium levels made SIADH and RSWS the most likely etiologies of his hyponatremia. To confirm the etiology, we waited for correction of his serum sodium. Therefore, we treated him with a combination of sodium repletion with 0.9% sodium chloride (154 mEq/L), hypertonic relative to his serum sodium, sodium chloride tablets, and free-water restriction. In this approach, we attempted to harmonize the treatment strategies for both SIADH and RSWS and effectively corrected his serum sodium. We evaluated his response to our treatment with a basic metabolic panel every 6 to 8 hours. Had his serum sodium decreased < 120 mmol/L, we planned to transfer the patient to the intensive care unit for 3% sodium chloride and/or intensification of his fluid restriction. A significant worsening of his hyponatremia would have strongly suggested hyponatremia secondary to SIADH since isotonic saline can worsen hyponatremia due to increased free-water reabsorption in the collecting duct.16
To differentiate between SIADH and RSWS, we relied on the FEurate after sodium correction. Multiple case reports from Japan have characterized the distinction between the processes through FEurate and serum uric acid. While the optimal cut-off values for FEurate require additional investigation, values < 11% after serum sodium correction suggests SIADH, while a value > 11% suggests RSWS.17 Prior cases have also emphasized serum hypouricemia as a distinguishing characteristic in RSWS. However, our case illustrates that serum hypouricemia is less reliable in the setting of AKI. Due to his severe AKI, our patient could not efficiently clear uric acid, likely contributing to his hyperuricemia.
Ultimately, our patient had an FEurate > 20%, which was suggestive of RSWS. Nevertheless, we recognize limitations and confounders in our diagnosis and have reflected on our diagnostic and management choices. First, the sensitivity and specificity of postsodium correction FEurate is unknown. Tracking the change in FEurate with our interventions would have increased our diagnostic utility, as suggested by Maesaka and colleagues.14 Second, our patient’s serum sodium was still at the lower end of the reference range after treatment, which may decrease the specificity of FEurate. Third, a plasma ADH collected during the initial phase of symptomatic hyponatremia would have helped differentiate between SIADH and RSWS.
Other diagnostic tests that could have excluded alternative diagnoses with even greater certainty include plasma adrenocorticotropic hormone, B-type natriuretic peptide, renin, cortisol, and thyroid function tests. From a practical standpoint, these laboratory results (excluding thyroid function test and brain natriuretic peptide) would have taken several weeks to result at our institution, limiting their clinical utility. Similarly, FEurate also has limited clinical utility, requiring effective treatment as part of the diagnostic test. Therefore, we recommend focusing on optimal treatment for hyponatremia of uncertain etiology, especially where SIADH and RSWS are the leading diagnoses.
Conclusions
We described a rare case of concomitant cisplatin-induced severe AKI and RSWS. We have emphasized the diagnostic challenge of distinguishing between SIADH and RSWS, especially with concomitant AKI, and have acknowledged that optimal treatment relies on accurate differentiation. However, differentiation may not be clinically feasible. Therefore, we suggest a treatment strategy that incorporates both free-water restriction and sodium supplementation via IV and/or oral administration.
Cisplatin is a potent antineoplastic agent derived from platinum and commonly used in the treatment of head and neck, bladder, ovarian, and testicular malignancies.1,2 Approximately 20% of all cancer patients are prescribed platinum-based chemotherapeutics.3 Although considered highly effective, cisplatin is also a dose-dependent nephrotoxin, inducing apoptosis in the proximal tubules of the nephron and reducing glomerular filtration rate. This nephron injury leads to inflammation and reduced medullary blood flow, causing further ischemic damage to the tubular cells.4 Given that the proximal tubule reabsorbs 67% of all sodium, cisplatin-induced nephron injuries can also lead to hyponatremia.5
The primary mechanisms of hyponatremia following cisplatin chemotherapy are syndrome of inappropriate antidiuretic hormone secretion (SIADH) and renal salt wasting syndrome (RSWS). Though these diagnoses have similar presentations, the treatment recommendations are different due to pathophysiologic differences. Fluid restriction is the hallmark of SIADH treatment, while increased sodium intake remains the hallmark of RSWS treatment.6 This patient presented with a combination of cisplatin-induced acute kidney injury (AKI) and hyponatremia secondary to RSWS. While RSWS and AKI are known complications of cisplatin chemotherapy, the combination is underreported in the literature. Therefore, this case report highlights the combination of these cisplatin-induced complications, emphasizes the clinical challenges in differentiating SIADH from RSWS, especially in the presence of a concomitant AKI, and suggests a treatment approach during diagnostic uncertainty.
Case Presentation
A 71-year-old man with a medical history of squamous cell carcinoma (SCC) of the left neck on cycle 1, day 8 of cisplatin-based chemotherapy and ongoing radiation therapy (720 cGy of 6300 cGy), lung adenocarcinoma status postresection, and hyperlipidemia presented to the emergency department (ED) at the request of his oncologist for abnormal laboratory values. In the ED, his metabolic panel showed a 131-mmol/L serum sodium, 3.3 mmol/L potassium, 83 mmol/L chloride, 29 mmol/L bicarbonate, 61 mg/dL blood urea nitrogen (BUN), and 8.8 mg/dL creatinine (baseline, 0.9 mg/dL). The patient reported throbbing headaches, persistent nausea, and multiple episodes of nonbloody emesis for several days that he attributed to his chemotherapy. He noted decreased urination without discomfort or changes in color or odor and no fatigue, fevers, chills, hematuria, flank, abdominal pain, thirst, or polydipsia. He reported no toxic ingestions or IV drug use. The patient had no relevant family history or additional social history. His outpatient medications included 10 mg cetirizine, 8 mg ondansetron, and 81 mg aspirin. On initial examination, his 137/66 mm Hg blood pressure was mildly elevated. The physical examination findings were notable for a 5-cm mass in the left neck that was firm and irregularly-shaped. His physical examination was otherwise unremarkable. He was admitted to the inpatient medicine service for an AKI complicated by symptomatic hyponatremia.
Investigations
We evaluated the patient’s AKI based on treatment responsiveness, imaging, and laboratory testing. Renal and bladder ultrasound showed no evidence of hydronephrosis or obstruction. He had a benign urinalysis with microscopy absent for protein, blood, ketones, leukocyte esterase, nitrites, and cellular casts. His urine pH was 5.5 (reference range, 5.0-9.0) and specific gravity was 1.011 (reference range, 1.005-1.030). His urine electrolytes revealed 45-mmol/L urine sodium (reference range, 40-220), 33-mmol/L urine chloride (reference range, 110-250), 10-mmol/L urine potassium (reference range, 25-120), 106.7-mg/dL urine creatinine (reference range, 10-400) and a calculated 2.7% fractional excretion of sodium (FENa) and 22.0-mEq/L elevated urine anion gap. As a fluid challenge, he was treated with IV 0.9% sodium chloride at 100-125 mL/h, receiving 3 liters over the first 48 hours of his hospitalization. His creatinine peaked at 9.2 mg/dL and stabilized before improving later in his hospitalization (Figure 1). The patient initially had oliguria (< 0.5 mL/kg/h), which slowly improved over his hospital course. Unfortunately, due to multiple system and clinical factors, accurate inputs and outputs were not adequately maintained during his hospitalization.
We evaluated hyponatremia with a combination of serum and urine laboratory tests. In addition to urine electrolytes, the initial evaluation focused on trending his clinical trajectory. We repeated a basic metabolic panel every 4 to 6 hours. He had 278-mOsm/kg serum osmolality (reference range, 285-295) with an effective 217-mOsm/kg serum tonicity. His urine osmolality was 270.5 mOsm/kg.
Despite administering 462 mEq sodium via crystalloid, his sodium worsened over the first 48 hours, reaching a nadir at 125 mmol/L on hospital day 3 (Figure 2). While he continued to appear euvolemic on physical examination, his blood pressure became difficult to control with 160- to 180-mm Hg systolic blood pressure readings. His thyroid stimulating hormone (TSH) was normal and aldosterone was low (4 ng/dL). Additional urine studies, including a 24-hour urine sample, were collected for further evaluation. His urine uric acid was 140 mg/d (reference range, 120-820); his serum uric acid level was 8.2 mg/dL (reference range, 3.0-9.0). His 24-hour urine creatinine was 0.57 g/d (reference range, 0.50-2.15) and uric acid to creatinine ratio was 246 mg/g (reference range, 60-580). His serum creatinine collected from the same day as his 24-hour urine sample was 7.3 mg/dL. His fractional excretion of uric acid (FEurate) was 21.9%.
Differential Diagnosis
The patient’s recent administration of cisplatin raised clinical suspicion of cisplatin-induced AKI. To avoid premature diagnostic closure, we used a systematic approach for thinking about our patient’s AKI, considering prerenal, intrarenal, and postrenal etiologies. The unremarkable renal and bladder ultrasound made a postrenal etiology unlikely. The patient’s 2.7% FENa in the absence of a diuretic, limited responsiveness to crystalloid fluid resuscitation, 7.5 serum BUN/creatinine ratio, and 270.5 mOsm/kg urine osmolality suggested an intrarenal etiology, which can be further divided into problems with glomeruli, tubules, small vessels, or interstitial space. The patient’s normal urinary microscopy with no evidence of protein, blood, ketones, leukocyte esterase, nitrites, or cellular casts made a glomerular etiology less likely. The acute onset and lack of additional systemic features, other than hypertension, made a vascular etiology less likely. A tubular etiology, such as acute tubular necrosis (ATN), was highest on the differential and was followed by an interstitial etiology, such as acute interstitial nephritis (AIN).
Patients with drug-induced AIN commonly present with signs and symptoms of an allergic-type reaction, including fever, rash, hematuria, pyuria, and costovertebral angle tenderness. The patient lacked these symptoms. However, cisplatin is known to cause ATN in up to 20-30% of patients.7 Therefore, despite the lack of the classic muddy-brown, granular casts on urine microscopy, cisplatin-induced ATN remained the most likely etiology of his AKI. Moreover, ATN can cause hyponatremia. ATN is characterized by 3 phases: initiation, maintenance, and recovery phases.8 Hyponatremia occurs during the recovery phase, typically starting weeks after renal insult and associated with high urine output and diuresis. This patient presented 1 week after injury and had persistent oliguria, making ATN an unlikely culprit of his hyponatremia.
Our patient presented with hypotonic hyponatremia with a 131 mmol/L initial sodium level and an < 280 mOsm/kg effective serum osmolality, or serum tonicity. The serum tonicity is equivalent to the difference between the measured serum osmolality and the BUN. In the setting of profound AKI, this adjustment is essential for correctly categorizing a patient’s hyponatremia as hyper-, iso-, or hypotonic. The differential diagnosis for this patient’s hypotonic hyponatremia included dilutional effects of hypervolemia, SIADH, hyperthyroidism, adrenal insufficiency, and RSWS. The patient’s volume examination, lack of predisposing comorbidities or suggestive biomarkers, and > 20 mmol/L urinary sodium made hypervolemia unlikely. His urinary osmolality and specific gravity made primary polydipsia unlikely. We worked up his hyponatremia according to a diagnostic algorithm (eAppendix available at doi:10.12788/fp.0198).
The patient had a 217 mOsm/kg serum tonicity and a 270.5 mOsm/kg urine osmolality, consistent with impaired water excretion. His presentation, TSH, and concordant decrease in sodium and potassium made an endocrine etiology of his hyponatremia less likely. In hindsight, a serum cortisol would have been beneficial to more completely exclude adrenal insufficiency. His urine sodium was elevated at 45 mmol/L, raising concern for RSWS or SIADH. The FEurate helped to distinguish between SIADH and RSWS. While FEurate is often elevated in both SIADH and RSWS initially, the FEurate normalizes in SIADH with normalization of the serum sodium. The ideal cutoff for posthyponatremia correction FEurate is debated; however, a FEurate value after sodium correction < 11% suggests SIADH while a value > 11% suggests RSWS.9 Our patient’s FEurate following the sodium correction (serum sodium 134 mmol/L) was 21.9%, most suggestive of RSWS.
Treatment
Upon admission, initial treatment focused on resolving the patient’s AKI. The oncology team discontinued the cisplatin-based chemotherapy. His medication dosages were adjusted for his renal function and additional nephrotoxins avoided. In consultation, the nephrology service recommended 100 mL/h fluid resuscitation. After the patient received 3 L of 0.9% sodium chloride, his creatinine showed limited improvement and his sodium worsened, trending from 131 mmol/L to a nadir of 125 mmol/L. We initiated oral free-water restriction while continuing IV infusion of 0.9% sodium chloride at 125 mL/h.
We further augmented his sodium intake with 1-g sodium chloride tablets with each meal. By hospital day 6, the patient’s serum sodium, BUN, and creatinine improved to 130 mEq/L, 50 mg/dL, and 7.7 mg/dL, respectively. We then discontinued the oral sodium chloride tablets, fluid restriction, and IV fluids in a stepwise fashion prior to discharge. At discharge, the patient’s serum sodium was 136 mEq/L and creatinine, 4.8 mg/dL. The patient’s clinical course was complicated by symptomatic hypertension with systolic blood pressures about 180 mm Hg, requiring intermittent IV hydralazine, which was transitioned to daily nifedipine. Concerned that fluid resuscitation contributed to his hypertension, the patient also received several doses of furosemide. At time of discharge, the patient remained hypertensive and was discharged with nifedipine 90 mg daily.
Outcome and Follow-up
The patient has remained stable clinically since discharge. One week after discharge, his serum sodium and creatinine were 138 mmol/L and 3.8 mg/dL, respectively. More than 1 month after discharge, his sodium remains in the reference range and his creatinine was stable at about 3.5 mg/dL. He continues to follow-up with nephrology, oncology, and radiation oncology. He has restarted chemotherapy with a carboplatin-based regimen without recurrence of hyponatremia or AKI. His blood pressure has gradually improved to the point where he no longer requires nifedipine.
Discussion
The US Food and Drug Administration first approved the use of cisplatin, an alkylating agent that inhibits DNA replication, in 1978 for the treatment of testicular cancer.10 Since its approval, cisplatin has increased in popularity and is now considered one of the most effective antineoplastic agents for the treatment of solid tumors.1 Unfortunately, cisplatin has a well-documented adverse effect profile that includes neurotoxicity, gastrointestinal toxicity, nephrotoxicity, and ototoxicity.4 Despite frequent nephrotoxicity, cisplatin only occasionally causes hyponatremia and rarely causes RSWS, a known but potentially fatal complication. Moreover, the combination of AKI and RSWS is unique. Our patient presented with the unique combination of AKI and hyponatremia, most consistent with RSWS, likely precipitated from cisplatin chemotherapy. Through this case, we review cisplatin-associated electrolyte abnormalities, highlight the challenge of differentiating SIADH and RSWS, and suggest a treatment approach for hyponatremia during the period of diagnostic uncertainty.
Blachley and colleagues first discussed renal and electrolyte disturbances, specifically magnesium wasting, secondary to cisplatin use in 1981. In 1984, Kurtzberg and colleagues noted salt wasting in 2 patients receiving cisplatin therapy. The authors suggested that cisplatin inhibits solute transport in the thick ascending limb, causing clinically significant electrolyte abnormalities, coining the term cisplatin-induced salt wasting.11
The prevalence of cisplatin-induced salt wasting is unclear and likely underreported. In 1988, Hutchinson and colleagues conducted a prospective cohort study and noted 10% of patients (n = 70) developed RSWS at some point over 18 months of cisplatin therapy—a higher rate than previously estimated.12 In 1992, another prospective cohort study evaluated the adverse effects of 47 patients with non-small cell lung cancer treated with cisplatin and reported hyponatremia in 43% of its 93 courses of chemotherapy. The authors did not report the etiology of these hyponatremia cases.13 Given the diagnostic challenge, RSWS may be underrepresented as a confirmed etiology of hyponatremia in cisplatin treatment.
Hyponatremia from cisplatin may present as either SIADH or RSWS, complicating treatment decisions. Both conditions lead to hypotonic hyponatremia with urine osmolality > 100 mOSm/kg and urine sodium levels > 40 mmol/L. However, pathophysiology behind SIADH and RSWS is different. In RSWS, proximal tubule damage causes hyponatremia, decreasing sodium reabsorption, and leading to impaired concentration gradient in every segment of the nephron. As a result, RSWS can lead to profound hyponatremia. Treatment typically consists of increasing sodium intake to correct serum sodium with salt tablets and hypertonic sodium chloride while treating the underlying etiology, in our case removing the offending agent, and waiting for proximal tubule function to recover.6 On the other hand, in SIADH, elevated antidiuretic hormone (ADH) increases water reabsorption in the collecting duct, which has no impact on concentration gradients of the other nephron segments.14 Free-water restriction is the hallmark of SIADH treatment. Severe SIADH may require sodium repletion and/or the initiation of vaptans, ADH antagonists that competitively inhibit V2 receptors in the collecting duct to prevent water reabsorption.15
Our patient had an uncertain etiology of his hyponatremia throughout most of his treatment course, complicating our treatment decision-making. Initially, his measured serum osmolality was 278 mOsm/kg; however, his effective tonicity was lower. His AKI elevated his BUN, which in turnrequired us to calculate his serum tonicity (217 mOsm/kg) that was consistent with hypotonic hyponatremia. His elevated urine osmolality and urine sodium levels made SIADH and RSWS the most likely etiologies of his hyponatremia. To confirm the etiology, we waited for correction of his serum sodium. Therefore, we treated him with a combination of sodium repletion with 0.9% sodium chloride (154 mEq/L), hypertonic relative to his serum sodium, sodium chloride tablets, and free-water restriction. In this approach, we attempted to harmonize the treatment strategies for both SIADH and RSWS and effectively corrected his serum sodium. We evaluated his response to our treatment with a basic metabolic panel every 6 to 8 hours. Had his serum sodium decreased < 120 mmol/L, we planned to transfer the patient to the intensive care unit for 3% sodium chloride and/or intensification of his fluid restriction. A significant worsening of his hyponatremia would have strongly suggested hyponatremia secondary to SIADH since isotonic saline can worsen hyponatremia due to increased free-water reabsorption in the collecting duct.16
To differentiate between SIADH and RSWS, we relied on the FEurate after sodium correction. Multiple case reports from Japan have characterized the distinction between the processes through FEurate and serum uric acid. While the optimal cut-off values for FEurate require additional investigation, values < 11% after serum sodium correction suggests SIADH, while a value > 11% suggests RSWS.17 Prior cases have also emphasized serum hypouricemia as a distinguishing characteristic in RSWS. However, our case illustrates that serum hypouricemia is less reliable in the setting of AKI. Due to his severe AKI, our patient could not efficiently clear uric acid, likely contributing to his hyperuricemia.
Ultimately, our patient had an FEurate > 20%, which was suggestive of RSWS. Nevertheless, we recognize limitations and confounders in our diagnosis and have reflected on our diagnostic and management choices. First, the sensitivity and specificity of postsodium correction FEurate is unknown. Tracking the change in FEurate with our interventions would have increased our diagnostic utility, as suggested by Maesaka and colleagues.14 Second, our patient’s serum sodium was still at the lower end of the reference range after treatment, which may decrease the specificity of FEurate. Third, a plasma ADH collected during the initial phase of symptomatic hyponatremia would have helped differentiate between SIADH and RSWS.
Other diagnostic tests that could have excluded alternative diagnoses with even greater certainty include plasma adrenocorticotropic hormone, B-type natriuretic peptide, renin, cortisol, and thyroid function tests. From a practical standpoint, these laboratory results (excluding thyroid function test and brain natriuretic peptide) would have taken several weeks to result at our institution, limiting their clinical utility. Similarly, FEurate also has limited clinical utility, requiring effective treatment as part of the diagnostic test. Therefore, we recommend focusing on optimal treatment for hyponatremia of uncertain etiology, especially where SIADH and RSWS are the leading diagnoses.
Conclusions
We described a rare case of concomitant cisplatin-induced severe AKI and RSWS. We have emphasized the diagnostic challenge of distinguishing between SIADH and RSWS, especially with concomitant AKI, and have acknowledged that optimal treatment relies on accurate differentiation. However, differentiation may not be clinically feasible. Therefore, we suggest a treatment strategy that incorporates both free-water restriction and sodium supplementation via IV and/or oral administration.
1. Dasari S, Tchounwou PB. Cisplatin in cancer therapy: molecular mechanisms of action. Eur J Pharmacol. 2014;740:364-378. doi:10.1016/j.ejphar.2014.07.025
2. Holditch SJ, Brown CN, Lombardi AM, Nguyen KN, Edelstein CL. Recent advances in models, mechanisms, biomarkers, and interventions in cisplatin-induced acute kidney injury. Int J Mol Sci. 2019;20(12):3011. Published 2019 Jun 20. doi:10.3390/ijms20123011
3. National Institutes of Health, National Cancer Institute. The “accidental” cure—platinum-based treatment for cancer: the discovery of cisplatin. Published May 30, 2014. Accessed November 10, 2021. https://www.cancer.gov/research/progress/discovery/cisplatin
4. Ozkok A, Edelstein CL. Pathophysiology of cisplatin-induced acute kidney injury. Biomed Res Int. 2014;2014:967826. doi:10.1155/2014/967826
5. Palmer LG, Schnermann J. Integrated control of Na transport along the nephron. Clin J Am Soc Nephrol. 2015;10(4):676-687. doi:10.2215/CJN.12391213
6. Bitew S, Imbriano L, Miyawaki N, Fishbane S, Maesaka JK. More on renal salt wasting without cerebral disease: response to saline infusion. Clin J Am Soc Nephrol. 2009;4(2):309-315. doi:10.2215/CJN.02740608
7. Shirali AC, Perazella MA. Tubulointerstitial injury associated with chemotherapeutic agents. Adv Chronic Kidney Dis. 2014;21(1):56-63. doi:10.1053/j.ackd.2013.06.010
8. Agrawal M, Swartz R. Acute renal failure [published correction appears in Am Fam Physician 2001 Feb 1;63(3):445]. Am Fam Physician. 2000;61(7):2077-2088.
9. Milionis HJ, Liamis GL, Elisaf MS. The hyponatremic patient: a systematic approach to laboratory diagnosis. CMAJ. 2002;166(8):1056-1062.
10. Monneret C. Platinum anticancer drugs. From serendipity to rational design. Ann Pharm Fr. 2011;69(6):286-295. doi:10.1016/j.pharma.2011.10.001
11. Kurtzberg J, Dennis VW, Kinney TR. Cisplatinum-induced renal salt wasting. Med Pediatr Oncol. 1984;12(2):150-154. doi:10.1002/mpo.2950120219
12. Hutchison FN, Perez EA, Gandara DR, Lawrence HJ, Kaysen GA. Renal salt wasting in patients treated with cisplatin. Ann Intern Med. 1988;108(1):21-25. doi:10.7326/0003-4819-108-1-21
13. Lee YK, Shin DM. Renal salt wasting in patients treated with high-dose cisplatin, etoposide, and mitomycin in patients with advanced non-small cell lung cancer. Korean J Intern Med. 1992;7(2):118-121. doi:10.3904/kjim.1992.7.2.118
14. Maesaka JK, Imbriano L, Mattana J, Gallagher D, Bade N, Sharif S. Differentiating SIADH from cerebral/renal salt wasting: failure of the volume approach and need for a new approach to hyponatremia. J Clin Med. 2014;3(4):1373-1385. Published 2014 Dec 8. doi:10.3390/jcm3041373
15. Palmer BF. The role of v2 receptor antagonists in the treatment of hyponatremia. Electrolyte Blood Press. 2013;11(1):1-8. doi:10.5049/EBP.2013.11.1.1
16. Verbalis JG, Goldsmith SR, Greenberg A, Schrier RW, Sterns RH. Hyponatremia treatment guidelines 2007: expert panel recommendations. Am J Med. 2007;120(11 Suppl 1):S1-S21. doi:10.1016/j.amjmed.2007.09.001
17. Maesaka JK, Imbriano LJ, Miyawaki N. High prevalence of renal salt wasting without cerebral disease as cause of hyponatremia in general medical wards. Am J Med Sci. 2018;356(1):15-22. doi:10.1016/j.amjms.2018.03.02
1. Dasari S, Tchounwou PB. Cisplatin in cancer therapy: molecular mechanisms of action. Eur J Pharmacol. 2014;740:364-378. doi:10.1016/j.ejphar.2014.07.025
2. Holditch SJ, Brown CN, Lombardi AM, Nguyen KN, Edelstein CL. Recent advances in models, mechanisms, biomarkers, and interventions in cisplatin-induced acute kidney injury. Int J Mol Sci. 2019;20(12):3011. Published 2019 Jun 20. doi:10.3390/ijms20123011
3. National Institutes of Health, National Cancer Institute. The “accidental” cure—platinum-based treatment for cancer: the discovery of cisplatin. Published May 30, 2014. Accessed November 10, 2021. https://www.cancer.gov/research/progress/discovery/cisplatin
4. Ozkok A, Edelstein CL. Pathophysiology of cisplatin-induced acute kidney injury. Biomed Res Int. 2014;2014:967826. doi:10.1155/2014/967826
5. Palmer LG, Schnermann J. Integrated control of Na transport along the nephron. Clin J Am Soc Nephrol. 2015;10(4):676-687. doi:10.2215/CJN.12391213
6. Bitew S, Imbriano L, Miyawaki N, Fishbane S, Maesaka JK. More on renal salt wasting without cerebral disease: response to saline infusion. Clin J Am Soc Nephrol. 2009;4(2):309-315. doi:10.2215/CJN.02740608
7. Shirali AC, Perazella MA. Tubulointerstitial injury associated with chemotherapeutic agents. Adv Chronic Kidney Dis. 2014;21(1):56-63. doi:10.1053/j.ackd.2013.06.010
8. Agrawal M, Swartz R. Acute renal failure [published correction appears in Am Fam Physician 2001 Feb 1;63(3):445]. Am Fam Physician. 2000;61(7):2077-2088.
9. Milionis HJ, Liamis GL, Elisaf MS. The hyponatremic patient: a systematic approach to laboratory diagnosis. CMAJ. 2002;166(8):1056-1062.
10. Monneret C. Platinum anticancer drugs. From serendipity to rational design. Ann Pharm Fr. 2011;69(6):286-295. doi:10.1016/j.pharma.2011.10.001
11. Kurtzberg J, Dennis VW, Kinney TR. Cisplatinum-induced renal salt wasting. Med Pediatr Oncol. 1984;12(2):150-154. doi:10.1002/mpo.2950120219
12. Hutchison FN, Perez EA, Gandara DR, Lawrence HJ, Kaysen GA. Renal salt wasting in patients treated with cisplatin. Ann Intern Med. 1988;108(1):21-25. doi:10.7326/0003-4819-108-1-21
13. Lee YK, Shin DM. Renal salt wasting in patients treated with high-dose cisplatin, etoposide, and mitomycin in patients with advanced non-small cell lung cancer. Korean J Intern Med. 1992;7(2):118-121. doi:10.3904/kjim.1992.7.2.118
14. Maesaka JK, Imbriano L, Mattana J, Gallagher D, Bade N, Sharif S. Differentiating SIADH from cerebral/renal salt wasting: failure of the volume approach and need for a new approach to hyponatremia. J Clin Med. 2014;3(4):1373-1385. Published 2014 Dec 8. doi:10.3390/jcm3041373
15. Palmer BF. The role of v2 receptor antagonists in the treatment of hyponatremia. Electrolyte Blood Press. 2013;11(1):1-8. doi:10.5049/EBP.2013.11.1.1
16. Verbalis JG, Goldsmith SR, Greenberg A, Schrier RW, Sterns RH. Hyponatremia treatment guidelines 2007: expert panel recommendations. Am J Med. 2007;120(11 Suppl 1):S1-S21. doi:10.1016/j.amjmed.2007.09.001
17. Maesaka JK, Imbriano LJ, Miyawaki N. High prevalence of renal salt wasting without cerebral disease as cause of hyponatremia in general medical wards. Am J Med Sci. 2018;356(1):15-22. doi:10.1016/j.amjms.2018.03.02
Apixaban a reasonable alternative to warfarin in patients with severe renal impairment
Background: Over 6 million Americans are prescribed anticoagulation; however, available anticoagulation options for patients with concomitant renal impairment are limited. Until recently, warfarin was the only recommended option because of a lack of data to support the use of alternative agents in such patients. This study evaluates the safety and effectiveness of apixaban, compared with warfarin, in patients with severe renal dysfunction.
Study design: Multicenter retrospective cohort study.
Setting: Seven hospitals in Michigan between January 2013 and December 2015 and including adult patients with CrCl less than 25 cc/min who were newly initiated on apixaban or warfarin.
Synopsis: Patients in the apixaban group (n=128) had a higher rate of heart failure, atrial fibrillation, stent placement, and hyperlipidemia, while the warfarin group (n=733) had a higher rate of prior venous thromboembolism. The primary outcome was time to first bleeding or thrombotic event. Apixaban was associated with a lower risk of thrombotic or bleeding events, compared with warfarin (HR, 0.47). Post-hoc analysis controlling for patient differences showed similar results. There was no statistical difference in the severity of events or overall mortality. Further subgroup analysis showed that 5 mg B.I.D. dosing was not associated with higher risk of bleeding than 2.5 mg B.I.D.
The main limitation is the retrospective observational design, which may have introduced confounding variables that were not accounted for in the analyses. The study also did not account for patient nonadherence to medication.
Bottom line: Apixaban is a reasonable alternative to warfarin in patients with severe renal impairment.
Citation: Hanni C et al. Outcomes associated with apixaban vs. warfarin in patients with renal dysfunction. Blood Adv. 2020;4(11): 2366-71. doi: 10.1182/bloodadvances.2019000972.
Dr. Narayan is a hospitalist in the Division of Hospital Medicine, Mount Sinai Health System, New York.
Background: Over 6 million Americans are prescribed anticoagulation; however, available anticoagulation options for patients with concomitant renal impairment are limited. Until recently, warfarin was the only recommended option because of a lack of data to support the use of alternative agents in such patients. This study evaluates the safety and effectiveness of apixaban, compared with warfarin, in patients with severe renal dysfunction.
Study design: Multicenter retrospective cohort study.
Setting: Seven hospitals in Michigan between January 2013 and December 2015 and including adult patients with CrCl less than 25 cc/min who were newly initiated on apixaban or warfarin.
Synopsis: Patients in the apixaban group (n=128) had a higher rate of heart failure, atrial fibrillation, stent placement, and hyperlipidemia, while the warfarin group (n=733) had a higher rate of prior venous thromboembolism. The primary outcome was time to first bleeding or thrombotic event. Apixaban was associated with a lower risk of thrombotic or bleeding events, compared with warfarin (HR, 0.47). Post-hoc analysis controlling for patient differences showed similar results. There was no statistical difference in the severity of events or overall mortality. Further subgroup analysis showed that 5 mg B.I.D. dosing was not associated with higher risk of bleeding than 2.5 mg B.I.D.
The main limitation is the retrospective observational design, which may have introduced confounding variables that were not accounted for in the analyses. The study also did not account for patient nonadherence to medication.
Bottom line: Apixaban is a reasonable alternative to warfarin in patients with severe renal impairment.
Citation: Hanni C et al. Outcomes associated with apixaban vs. warfarin in patients with renal dysfunction. Blood Adv. 2020;4(11): 2366-71. doi: 10.1182/bloodadvances.2019000972.
Dr. Narayan is a hospitalist in the Division of Hospital Medicine, Mount Sinai Health System, New York.
Background: Over 6 million Americans are prescribed anticoagulation; however, available anticoagulation options for patients with concomitant renal impairment are limited. Until recently, warfarin was the only recommended option because of a lack of data to support the use of alternative agents in such patients. This study evaluates the safety and effectiveness of apixaban, compared with warfarin, in patients with severe renal dysfunction.
Study design: Multicenter retrospective cohort study.
Setting: Seven hospitals in Michigan between January 2013 and December 2015 and including adult patients with CrCl less than 25 cc/min who were newly initiated on apixaban or warfarin.
Synopsis: Patients in the apixaban group (n=128) had a higher rate of heart failure, atrial fibrillation, stent placement, and hyperlipidemia, while the warfarin group (n=733) had a higher rate of prior venous thromboembolism. The primary outcome was time to first bleeding or thrombotic event. Apixaban was associated with a lower risk of thrombotic or bleeding events, compared with warfarin (HR, 0.47). Post-hoc analysis controlling for patient differences showed similar results. There was no statistical difference in the severity of events or overall mortality. Further subgroup analysis showed that 5 mg B.I.D. dosing was not associated with higher risk of bleeding than 2.5 mg B.I.D.
The main limitation is the retrospective observational design, which may have introduced confounding variables that were not accounted for in the analyses. The study also did not account for patient nonadherence to medication.
Bottom line: Apixaban is a reasonable alternative to warfarin in patients with severe renal impairment.
Citation: Hanni C et al. Outcomes associated with apixaban vs. warfarin in patients with renal dysfunction. Blood Adv. 2020;4(11): 2366-71. doi: 10.1182/bloodadvances.2019000972.
Dr. Narayan is a hospitalist in the Division of Hospital Medicine, Mount Sinai Health System, New York.