Venous Thromboembolism

All else being equal, I’d prefer to do nothing. Whether this is nihilism, laziness, or experience is a matter of debate. The American College of Chest Physicians (CHEST) Guidelines on therapy for venous thromboembolism (VTE) opened a door for withholding treatment for isolated subsegmental pulmonary embolism (ISSPE) in 2016 and kept it open in 2021. I was happy to walk through it and withhold therapy if it wasn’t indicated.

ISSPE is truly a conundrum. With advances in technology, the distal vessels in the lung became visible on commercial CT a little more than 10 years ago. The subsegmental branches are located after the fourth bifurcation of the pulmonary arterial system, and the new technology offered resolution adequate to identify clot in these vessels. But the new technology told us nothing about how to manage clot isolated to the subsegmental vasculature.

Autopsy data say clot in these vessels is common, even in patients who were never diagnosed with VTE while they were alive. To some degree then, the pulmonary arterial system is thought to serve as a filter to prevent clot from crossing to the systemic circulation and causing stroke. This led some to speculate that the subsegmental pulmonary arteries are supposed to contain clot and that we simply couldn’t see it before now. If this theory is correct, the practice of providing anticoagulation for ISSPE could increase bleeding without reducing the risk for VTE recurrence.

Management studies generally supported this concept. In 2007, a trial that was published in JAMA randomized patients to two different diagnostic strategies: ventilation-perfusion (VQ) and CT. CT detected more clot than VQ did, so more anticoagulation was given in the CT arm. Yet, the VTE rate during follow-up was not significantly different between arms. The implication? Some of the clots detected by CT were of lesser clinical significance and didn’t need to be treated.

Meta-analytic data from management trials also suggested that some pulmonary emboli (PE) need not be treated. Data also show when compared with patients who have more proximal PE, those with ISSPE have lower pretest probability for VTE, are less symptomatic, and have a lower burden of coexistent lower extremity thrombosis (deep vein thrombosis [DVT]).

In response to this data, the CHEST Guidelines began cautiously providing the option for withholding therapy in patients who were diagnosed with ISSPE in 2016. Their recommendations stated that patients should be stratified for recurrence risk and have lower extremity ultrasonography performed to rule out DVT. A patient with ISSPE, a low recurrence risk, and a negative ultrasound can have anticoagulation withheld. This made perfect sense to me based on what I thought I knew at the time.

Recently published data cast doubt on my nihilism. The first prospective study designed specifically to assess the safety of withholding therapy for ISSPE suggests that this practice could be dangerous. How did this happen? The trial was very well done, and the authors enrolled the right population. All of the patients had ISSPE, low recurrence risk, and negative lower extremity ultrasound. The authors were anticipating a 1% VTE rate at 90 days based on prior data but instead found a rate of 3.1% (1.6%-6.1%). They point out that this rate is not different from those seen in patients with more proximal PE who are treated with anticoagulation. However, they acknowledge that it is higher than what’s considered acceptable and warrants therapeutic anticoagulation.

So what should we do now? We treat ISSPE, that’s what. All the arguments for withholding therapy remain valid, the recurrence rate is reasonably low, and none of the recurrent VTEs in the new study were fatal. There’s still no doubt that some patients with PE won’t benefit from anticoagulation. Unfortunately, we currently lack the tools to identify them. The risk-benefit ratio for recurrence versus bleeding will be tighter with ISSPE, particularly when there’s only one clot. Unless the bleeding risk is elevated though, the ratio still favors treatment.

Aaron B. Holley, MD, is an associate professor of medicine at Uniformed Services University and program director of pulmonary and critical care medicine at Walter Reed National Military Medical Center.

A version of this article first appeared on Medscape.com.

All else being equal, I’d prefer to do nothing. Whether this is nihilism, laziness, or experience is a matter of debate. The American College of Chest Physicians (CHEST) Guidelines on therapy for venous thromboembolism (VTE) opened a door for withholding treatment for isolated subsegmental pulmonary embolism (ISSPE) in 2016 and kept it open in 2021. I was happy to walk through it and withhold therapy if it wasn’t indicated.

ISSPE is truly a conundrum. With advances in technology, the distal vessels in the lung became visible on commercial CT a little more than 10 years ago. The subsegmental branches are located after the fourth bifurcation of the pulmonary arterial system, and the new technology offered resolution adequate to identify clot in these vessels. But the new technology told us nothing about how to manage clot isolated to the subsegmental vasculature.

Autopsy data say clot in these vessels is common, even in patients who were never diagnosed with VTE while they were alive. To some degree then, the pulmonary arterial system is thought to serve as a filter to prevent clot from crossing to the systemic circulation and causing stroke. This led some to speculate that the subsegmental pulmonary arteries are supposed to contain clot and that we simply couldn’t see it before now. If this theory is correct, the practice of providing anticoagulation for ISSPE could increase bleeding without reducing the risk for VTE recurrence.

Management studies generally supported this concept. In 2007, a trial that was published in JAMA randomized patients to two different diagnostic strategies: ventilation-perfusion (VQ) and CT. CT detected more clot than VQ did, so more anticoagulation was given in the CT arm. Yet, the VTE rate during follow-up was not significantly different between arms. The implication? Some of the clots detected by CT were of lesser clinical significance and didn’t need to be treated.

Meta-analytic data from management trials also suggested that some pulmonary emboli (PE) need not be treated. Data also show when compared with patients who have more proximal PE, those with ISSPE have lower pretest probability for VTE, are less symptomatic, and have a lower burden of coexistent lower extremity thrombosis (deep vein thrombosis [DVT]).

In response to this data, the CHEST Guidelines began cautiously providing the option for withholding therapy in patients who were diagnosed with ISSPE in 2016. Their recommendations stated that patients should be stratified for recurrence risk and have lower extremity ultrasonography performed to rule out DVT. A patient with ISSPE, a low recurrence risk, and a negative ultrasound can have anticoagulation withheld. This made perfect sense to me based on what I thought I knew at the time.

Recently published data cast doubt on my nihilism. The first prospective study designed specifically to assess the safety of withholding therapy for ISSPE suggests that this practice could be dangerous. How did this happen? The trial was very well done, and the authors enrolled the right population. All of the patients had ISSPE, low recurrence risk, and negative lower extremity ultrasound. The authors were anticipating a 1% VTE rate at 90 days based on prior data but instead found a rate of 3.1% (1.6%-6.1%). They point out that this rate is not different from those seen in patients with more proximal PE who are treated with anticoagulation. However, they acknowledge that it is higher than what’s considered acceptable and warrants therapeutic anticoagulation.

So what should we do now? We treat ISSPE, that’s what. All the arguments for withholding therapy remain valid, the recurrence rate is reasonably low, and none of the recurrent VTEs in the new study were fatal. There’s still no doubt that some patients with PE won’t benefit from anticoagulation. Unfortunately, we currently lack the tools to identify them. The risk-benefit ratio for recurrence versus bleeding will be tighter with ISSPE, particularly when there’s only one clot. Unless the bleeding risk is elevated though, the ratio still favors treatment.

Aaron B. Holley, MD, is an associate professor of medicine at Uniformed Services University and program director of pulmonary and critical care medicine at Walter Reed National Military Medical Center.

A version of this article first appeared on Medscape.com.

All else being equal, I’d prefer to do nothing. Whether this is nihilism, laziness, or experience is a matter of debate. The American College of Chest Physicians (CHEST) Guidelines on therapy for venous thromboembolism (VTE) opened a door for withholding treatment for isolated subsegmental pulmonary embolism (ISSPE) in 2016 and kept it open in 2021. I was happy to walk through it and withhold therapy if it wasn’t indicated.

ISSPE is truly a conundrum. With advances in technology, the distal vessels in the lung became visible on commercial CT a little more than 10 years ago. The subsegmental branches are located after the fourth bifurcation of the pulmonary arterial system, and the new technology offered resolution adequate to identify clot in these vessels. But the new technology told us nothing about how to manage clot isolated to the subsegmental vasculature.

Autopsy data say clot in these vessels is common, even in patients who were never diagnosed with VTE while they were alive. To some degree then, the pulmonary arterial system is thought to serve as a filter to prevent clot from crossing to the systemic circulation and causing stroke. This led some to speculate that the subsegmental pulmonary arteries are supposed to contain clot and that we simply couldn’t see it before now. If this theory is correct, the practice of providing anticoagulation for ISSPE could increase bleeding without reducing the risk for VTE recurrence.

Management studies generally supported this concept. In 2007, a trial that was published in JAMA randomized patients to two different diagnostic strategies: ventilation-perfusion (VQ) and CT. CT detected more clot than VQ did, so more anticoagulation was given in the CT arm. Yet, the VTE rate during follow-up was not significantly different between arms. The implication? Some of the clots detected by CT were of lesser clinical significance and didn’t need to be treated.

Meta-analytic data from management trials also suggested that some pulmonary emboli (PE) need not be treated. Data also show when compared with patients who have more proximal PE, those with ISSPE have lower pretest probability for VTE, are less symptomatic, and have a lower burden of coexistent lower extremity thrombosis (deep vein thrombosis [DVT]).

In response to this data, the CHEST Guidelines began cautiously providing the option for withholding therapy in patients who were diagnosed with ISSPE in 2016. Their recommendations stated that patients should be stratified for recurrence risk and have lower extremity ultrasonography performed to rule out DVT. A patient with ISSPE, a low recurrence risk, and a negative ultrasound can have anticoagulation withheld. This made perfect sense to me based on what I thought I knew at the time.

Recently published data cast doubt on my nihilism. The first prospective study designed specifically to assess the safety of withholding therapy for ISSPE suggests that this practice could be dangerous. How did this happen? The trial was very well done, and the authors enrolled the right population. All of the patients had ISSPE, low recurrence risk, and negative lower extremity ultrasound. The authors were anticipating a 1% VTE rate at 90 days based on prior data but instead found a rate of 3.1% (1.6%-6.1%). They point out that this rate is not different from those seen in patients with more proximal PE who are treated with anticoagulation. However, they acknowledge that it is higher than what’s considered acceptable and warrants therapeutic anticoagulation.

So what should we do now? We treat ISSPE, that’s what. All the arguments for withholding therapy remain valid, the recurrence rate is reasonably low, and none of the recurrent VTEs in the new study were fatal. There’s still no doubt that some patients with PE won’t benefit from anticoagulation. Unfortunately, we currently lack the tools to identify them. The risk-benefit ratio for recurrence versus bleeding will be tighter with ISSPE, particularly when there’s only one clot. Unless the bleeding risk is elevated though, the ratio still favors treatment.

Aaron B. Holley, MD, is an associate professor of medicine at Uniformed Services University and program director of pulmonary and critical care medicine at Walter Reed National Military Medical Center.

A version of this article first appeared on Medscape.com.

Patients looking to refill a prescription for apixaban (Eliquis) through CVS Caremark may be in for a surprise following its decision to exclude the direct oral anticoagulant (DOAC) from its formulary starting Jan. 1.

The move leaves just one DOAC, rivaroxaban (Xarelto), on CVS’ commercial formulary and is being assailed as the latest example of “nonmedical switching” used by health insurers to control costs.

In a letter to CVS Caremark backed by 14 provider and patient organizations, the nonprofit Partnership to Advance Cardiovascular Health (PACH) calls on the pharmacy chain to reverse its “dangerously disruptive” decision to force stable patients at high risk of cardiovascular events to switch anticoagulation, without an apparent option to be grandfathered into the new plan.

PACH president Dharmesh Patel, MD, Stern Cardiovascular Center, Memphis, called the formulary change “reckless and irresponsible, especially because the decision is not based in science and evidence, but on budgets. Patients and their health care providers, not insurance companies, need to be trusted to determine what medication is best,” he said in a statement.

Craig Beavers, PharmD, vice president of Baptist Health Paducah, Kentucky, said that, as chair of the American College of Cardiology’s Cardiovascular Team Section, he and other organizations have met with CVS Caremark medical leadership to advocate for patients and to understand the company’s perspective.

“The underlying driver is cost,” he told this news organization.

Current guidelines recommend DOACs in general for a variety of indications, including to reduce the risk of stroke and embolism in nonvalvular atrial fibrillation and to prevent deep vein thrombosis, but there are select instances where a particular DOAC might be more appropriate, he observed.

“Apixaban may be better for a patient with a history of GI bleeding because there’s less GI bleeding, but the guidelines don’t necessarily spell those things out,” Dr. Beavers said. “That’s where the clinician should advocate for their patient and, unfortunately, they are making their decision strictly based off the guidelines.”

Requests to speak with medical officers at CVS Caremark went unanswered, but its executive director of communications, Christina Peaslee, told this news organization that the formulary decision “maintains clinically appropriate, cost-effective prescription coverage” for its clients and members.

“Both the American Heart Association/American College of Cardiology/Heart Rhythm Society and 2021 CHEST guidelines recommend DOACs over warfarin for treatment of various cardiology conditions such as atrial fibrillation, but neither list a specific agent as preferred – showing that consensus clinical guidelines do not favor one over the other,” she said in an email. “Further, Xarelto has more FDA-approved indications than Eliquis (e.g., Xarelto is approved for a reduction in risk of major CV events in patients with CAD or PAD) in addition to all the same FDA indications as Eliquis.”

Ms. Peaslee pointed out that all formulary changes are evaluated by an external medical expert specializing in the disease state, followed by review and approval by an independent national Pharmacy & Therapeutics Committee.

The decision to exclude apixaban is also limited to a “subset of commercial drug lists,” she said, although specifics on which plans and the number of affected patients were not forthcoming.

The choice of DOAC is a timely question in cardiology, with recent studies suggesting an advantage for apixaban over rivaroxaban in reducing the risk of recurrent venous thromboembolism, as well as reducing the risk of major ischemic or hemorrhagic events in atrial fibrillation.

Ms. Peaslee said CVS Caremark closely monitors medical literature for relevant clinical trial data and that most clients allow reasonable formulary exceptions when justified. “This formulary exceptions process has been successfully used for changes of this type and allows patients to get a medication that is safe and effective, as determined by their prescriber.”

The company will also continue to provide “robust, personalized outreach to the small number of members who will need to switch to an alternative medication,” she added.

Dr. Beavers said negotiations with CVS are still in the early stages, but, in the meantime, the ACC is providing health care providers with tools, such as drug copay cards and electronic prior authorizations, to help ensure patients don’t have gaps in coverage.

In a Jan. 14 news release addressing the formulary change, ACC notes that a patient’s pharmacy can also request a one-time override when trying to fill a nonpreferred DOAC in January to buy time if switching medications with their clinician or requesting a formulary exception.

During discussions with CVS Caremark, it says the ACC and the American Society of Hematology “underscored the negative impacts of this decision on patients currently taking one of the nonpreferred DOACs and on those who have previously tried rivaroxaban and changed medications.”

The groups also highlighted difficulties with other prior authorization programs in terms of the need for dedicated staff and time away from direct patient care.

“The ACC and ASH will continue discussions with CVS Caremark regarding the burden on clinicians and the effect of the formulary decision on patient access,” the release says.

In its letter to CVS, PACH argues that the apixaban exclusion will disproportionately affect historically disadvantaged patients, leaving those who can least afford the change with limited options. Notably, no generic is available for either apixaban or rivaroxaban.

The group also highlights a 2019 national poll, in which nearly 40% of patients who had their medication switched were so frustrated that they stopped their medication altogether.

PACH has an online petition against nonmedical switching, which at press time had garnered 2,126 signatures.

One signee, Jan Griffin, who survived bilateral pulmonary embolisms, writes that she has been on Eliquis [apixaban] successfully since her hospital discharge. “Now, as of midnight, Caremark apparently knows better than my hematologist as to what blood thinner is better for me and will no longer cover my Eliquis prescription. This is criminal, immoral, and unethical. #StopTheSwitch.”

A version of this article first appeared on Medscape.com.

Patients looking to refill a prescription for apixaban (Eliquis) through CVS Caremark may be in for a surprise following its decision to exclude the direct oral anticoagulant (DOAC) from its formulary starting Jan. 1.

The move leaves just one DOAC, rivaroxaban (Xarelto), on CVS’ commercial formulary and is being assailed as the latest example of “nonmedical switching” used by health insurers to control costs.

In a letter to CVS Caremark backed by 14 provider and patient organizations, the nonprofit Partnership to Advance Cardiovascular Health (PACH) calls on the pharmacy chain to reverse its “dangerously disruptive” decision to force stable patients at high risk of cardiovascular events to switch anticoagulation, without an apparent option to be grandfathered into the new plan.

PACH president Dharmesh Patel, MD, Stern Cardiovascular Center, Memphis, called the formulary change “reckless and irresponsible, especially because the decision is not based in science and evidence, but on budgets. Patients and their health care providers, not insurance companies, need to be trusted to determine what medication is best,” he said in a statement.

Craig Beavers, PharmD, vice president of Baptist Health Paducah, Kentucky, said that, as chair of the American College of Cardiology’s Cardiovascular Team Section, he and other organizations have met with CVS Caremark medical leadership to advocate for patients and to understand the company’s perspective.

“The underlying driver is cost,” he told this news organization.

Current guidelines recommend DOACs in general for a variety of indications, including to reduce the risk of stroke and embolism in nonvalvular atrial fibrillation and to prevent deep vein thrombosis, but there are select instances where a particular DOAC might be more appropriate, he observed.

“Apixaban may be better for a patient with a history of GI bleeding because there’s less GI bleeding, but the guidelines don’t necessarily spell those things out,” Dr. Beavers said. “That’s where the clinician should advocate for their patient and, unfortunately, they are making their decision strictly based off the guidelines.”

Requests to speak with medical officers at CVS Caremark went unanswered, but its executive director of communications, Christina Peaslee, told this news organization that the formulary decision “maintains clinically appropriate, cost-effective prescription coverage” for its clients and members.

“Both the American Heart Association/American College of Cardiology/Heart Rhythm Society and 2021 CHEST guidelines recommend DOACs over warfarin for treatment of various cardiology conditions such as atrial fibrillation, but neither list a specific agent as preferred – showing that consensus clinical guidelines do not favor one over the other,” she said in an email. “Further, Xarelto has more FDA-approved indications than Eliquis (e.g., Xarelto is approved for a reduction in risk of major CV events in patients with CAD or PAD) in addition to all the same FDA indications as Eliquis.”

Ms. Peaslee pointed out that all formulary changes are evaluated by an external medical expert specializing in the disease state, followed by review and approval by an independent national Pharmacy & Therapeutics Committee.

The decision to exclude apixaban is also limited to a “subset of commercial drug lists,” she said, although specifics on which plans and the number of affected patients were not forthcoming.

The choice of DOAC is a timely question in cardiology, with recent studies suggesting an advantage for apixaban over rivaroxaban in reducing the risk of recurrent venous thromboembolism, as well as reducing the risk of major ischemic or hemorrhagic events in atrial fibrillation.

Ms. Peaslee said CVS Caremark closely monitors medical literature for relevant clinical trial data and that most clients allow reasonable formulary exceptions when justified. “This formulary exceptions process has been successfully used for changes of this type and allows patients to get a medication that is safe and effective, as determined by their prescriber.”

The company will also continue to provide “robust, personalized outreach to the small number of members who will need to switch to an alternative medication,” she added.

Dr. Beavers said negotiations with CVS are still in the early stages, but, in the meantime, the ACC is providing health care providers with tools, such as drug copay cards and electronic prior authorizations, to help ensure patients don’t have gaps in coverage.

In a Jan. 14 news release addressing the formulary change, ACC notes that a patient’s pharmacy can also request a one-time override when trying to fill a nonpreferred DOAC in January to buy time if switching medications with their clinician or requesting a formulary exception.

During discussions with CVS Caremark, it says the ACC and the American Society of Hematology “underscored the negative impacts of this decision on patients currently taking one of the nonpreferred DOACs and on those who have previously tried rivaroxaban and changed medications.”

The groups also highlighted difficulties with other prior authorization programs in terms of the need for dedicated staff and time away from direct patient care.

“The ACC and ASH will continue discussions with CVS Caremark regarding the burden on clinicians and the effect of the formulary decision on patient access,” the release says.

In its letter to CVS, PACH argues that the apixaban exclusion will disproportionately affect historically disadvantaged patients, leaving those who can least afford the change with limited options. Notably, no generic is available for either apixaban or rivaroxaban.

The group also highlights a 2019 national poll, in which nearly 40% of patients who had their medication switched were so frustrated that they stopped their medication altogether.

PACH has an online petition against nonmedical switching, which at press time had garnered 2,126 signatures.

One signee, Jan Griffin, who survived bilateral pulmonary embolisms, writes that she has been on Eliquis [apixaban] successfully since her hospital discharge. “Now, as of midnight, Caremark apparently knows better than my hematologist as to what blood thinner is better for me and will no longer cover my Eliquis prescription. This is criminal, immoral, and unethical. #StopTheSwitch.”

A version of this article first appeared on Medscape.com.

Patients looking to refill a prescription for apixaban (Eliquis) through CVS Caremark may be in for a surprise following its decision to exclude the direct oral anticoagulant (DOAC) from its formulary starting Jan. 1.

The move leaves just one DOAC, rivaroxaban (Xarelto), on CVS’ commercial formulary and is being assailed as the latest example of “nonmedical switching” used by health insurers to control costs.

In a letter to CVS Caremark backed by 14 provider and patient organizations, the nonprofit Partnership to Advance Cardiovascular Health (PACH) calls on the pharmacy chain to reverse its “dangerously disruptive” decision to force stable patients at high risk of cardiovascular events to switch anticoagulation, without an apparent option to be grandfathered into the new plan.

PACH president Dharmesh Patel, MD, Stern Cardiovascular Center, Memphis, called the formulary change “reckless and irresponsible, especially because the decision is not based in science and evidence, but on budgets. Patients and their health care providers, not insurance companies, need to be trusted to determine what medication is best,” he said in a statement.

Craig Beavers, PharmD, vice president of Baptist Health Paducah, Kentucky, said that, as chair of the American College of Cardiology’s Cardiovascular Team Section, he and other organizations have met with CVS Caremark medical leadership to advocate for patients and to understand the company’s perspective.

“The underlying driver is cost,” he told this news organization.

Current guidelines recommend DOACs in general for a variety of indications, including to reduce the risk of stroke and embolism in nonvalvular atrial fibrillation and to prevent deep vein thrombosis, but there are select instances where a particular DOAC might be more appropriate, he observed.

“Apixaban may be better for a patient with a history of GI bleeding because there’s less GI bleeding, but the guidelines don’t necessarily spell those things out,” Dr. Beavers said. “That’s where the clinician should advocate for their patient and, unfortunately, they are making their decision strictly based off the guidelines.”

Requests to speak with medical officers at CVS Caremark went unanswered, but its executive director of communications, Christina Peaslee, told this news organization that the formulary decision “maintains clinically appropriate, cost-effective prescription coverage” for its clients and members.

“Both the American Heart Association/American College of Cardiology/Heart Rhythm Society and 2021 CHEST guidelines recommend DOACs over warfarin for treatment of various cardiology conditions such as atrial fibrillation, but neither list a specific agent as preferred – showing that consensus clinical guidelines do not favor one over the other,” she said in an email. “Further, Xarelto has more FDA-approved indications than Eliquis (e.g., Xarelto is approved for a reduction in risk of major CV events in patients with CAD or PAD) in addition to all the same FDA indications as Eliquis.”

Ms. Peaslee pointed out that all formulary changes are evaluated by an external medical expert specializing in the disease state, followed by review and approval by an independent national Pharmacy & Therapeutics Committee.

The decision to exclude apixaban is also limited to a “subset of commercial drug lists,” she said, although specifics on which plans and the number of affected patients were not forthcoming.

The choice of DOAC is a timely question in cardiology, with recent studies suggesting an advantage for apixaban over rivaroxaban in reducing the risk of recurrent venous thromboembolism, as well as reducing the risk of major ischemic or hemorrhagic events in atrial fibrillation.

Ms. Peaslee said CVS Caremark closely monitors medical literature for relevant clinical trial data and that most clients allow reasonable formulary exceptions when justified. “This formulary exceptions process has been successfully used for changes of this type and allows patients to get a medication that is safe and effective, as determined by their prescriber.”

The company will also continue to provide “robust, personalized outreach to the small number of members who will need to switch to an alternative medication,” she added.

Dr. Beavers said negotiations with CVS are still in the early stages, but, in the meantime, the ACC is providing health care providers with tools, such as drug copay cards and electronic prior authorizations, to help ensure patients don’t have gaps in coverage.

In a Jan. 14 news release addressing the formulary change, ACC notes that a patient’s pharmacy can also request a one-time override when trying to fill a nonpreferred DOAC in January to buy time if switching medications with their clinician or requesting a formulary exception.

During discussions with CVS Caremark, it says the ACC and the American Society of Hematology “underscored the negative impacts of this decision on patients currently taking one of the nonpreferred DOACs and on those who have previously tried rivaroxaban and changed medications.”

The groups also highlighted difficulties with other prior authorization programs in terms of the need for dedicated staff and time away from direct patient care.

“The ACC and ASH will continue discussions with CVS Caremark regarding the burden on clinicians and the effect of the formulary decision on patient access,” the release says.

In its letter to CVS, PACH argues that the apixaban exclusion will disproportionately affect historically disadvantaged patients, leaving those who can least afford the change with limited options. Notably, no generic is available for either apixaban or rivaroxaban.

The group also highlights a 2019 national poll, in which nearly 40% of patients who had their medication switched were so frustrated that they stopped their medication altogether.

PACH has an online petition against nonmedical switching, which at press time had garnered 2,126 signatures.

One signee, Jan Griffin, who survived bilateral pulmonary embolisms, writes that she has been on Eliquis [apixaban] successfully since her hospital discharge. “Now, as of midnight, Caremark apparently knows better than my hematologist as to what blood thinner is better for me and will no longer cover my Eliquis prescription. This is criminal, immoral, and unethical. #StopTheSwitch.”

A version of this article first appeared on Medscape.com.

Adapted D-dimer thresholds based on pretest probability were effective for ruling out pulmonary embolism (PE) in subgroups of high-risk individuals without the use of imaging in a review of data.

In a patient suspected to have a PE, “diagnosis is made radiographically, usually with CT pulmonary angiogram, or V/Q scan,” Suman Pal, MD, of the University of New Mexico, Albuquerque, said in an interview.

“Validated clinical decision tools such as Wells’ score or Geneva score may be used to identify patients at low pretest probability of PE who may initially get a D-dimer level check, followed by imaging only if D-dimer level is elevated,” explained Dr. Pal, who was not involved with the new research, which was published in the Annals of Internal Medicine.

According to the authors of the new paper, while current diagnostic strategies in patients with suspected PE include use of a validated clinical decision rule (CDR) and D-dimer testing to rule out PE without imaging tests, the effectiveness of D-dimer tests in older patients, inpatients, cancer patients, and other high-risk groups has not been well-studied.

Lead author of the paper, Milou A.M. Stals, MD, and colleagues said their goal was to evaluate the safety and efficiency of the Wells rule and revised Geneva score in combination with D-dimer tests, and also the YEARS algorithm for D-dimer thresholds, in their paper.

Dr. Stals, of Leiden (the Netherlands) University Medical Center, and the coinvestigators conducted an international systemic review and individual patient data meta-analysis that included 16 studies and 20,553 patients, with all studies having been published between Jan. 1, 1995, and Jan. 1, 2021. Their primary outcomes were the safety and efficiency of each of these three strategies.

In the review, the researchers defined safety as the 3-month incidence of venous thromboembolism after PE was ruled out without imaging at baseline. They defined efficiency as the proportion patients for whom PE was ruled out based on D-dimer thresholds without imaging.

Overall, efficiency was highest in the subset of patients aged younger than 40 years, ranging from 47% to 68% in this group. Efficiency was lowest in patients aged 80 years and older (6.0%-23%), and in patients with cancer (9.6%-26%).

The efficiency was higher when D-dimer thresholds based on pretest probability were used, compared with when fixed or age-adjusted D-dimer thresholds were used.

The key finding was the significant variability in performance of the diagnostic strategies, the researchers said.

“The predicted failure rate was generally highest for strategies incorporating adapted D-dimer thresholds. However, at the same time, predicted overall efficiency was substantially higher with these strategies versus strategies with a fixed D-dimer threshold as well,” they said. Given that the benefits of each of the three diagnostic strategies depends on their correct application, the researchers recommended that an individual hospitalist choose one strategy for their institution.

“Whether clinicians should rely on the Wells rule, the YEARS algorithm, or the revised Geneva score becomes a matter of local preference and experience,” Dr. Stals and colleagues wrote.

The study findings were limited by several factors including between-study differences in scoring predictors and D-dimer assays. Another limitation was that differential verification biases for classifying fatal events and PE may have contributed to overestimation of failure rates of the adapted D-dimer thresholds.

Strengths of the study included its large sample size and original data on pretest probability, and that data support the use of any of the three strategies for ruling out PE in the identified subgroups without the need for imaging tests, the authors wrote.

“Pending the results of ongoing diagnostic randomized trials, physicians and guideline committees should balance the interlink between safety and efficiency of available diagnostic strategies,” they concluded.

Adapted D-dimer benefits some patients

“Clearly, increasing the D-dimer cutoff will lower the number of patients who require radiographic imaging (improved specificity), but this comes with a risk for missing PE (lower sensitivity). Is this risk worth taking?” Daniel J. Brotman, MD, of Johns Hopkins University, Baltimore, asked in an editorial accompanying the new study.

Dr. Brotman was not surprised by the study findings.

“Conditions that predispose to thrombosis through activated hemostasis – such as advanced age, cancer, inflammation, prolonged hospitalization, and trauma – drive D-dimer levels higher independent of the presence or absence of radiographically apparent thrombosis,” he said. However, these patients are unlikely to have normal D-dimer levels regardless of the cutoff used.

Adapted D-dimer cutoffs may benefit some patients, including those with contraindications or limited access to imaging, said Dr. Brotman. D-dimer may be used for risk stratification regardless of PE, since patients with marginally elevated D-dimers have better prognoses than those with higher D-dimer elevations, even if a small PE is missed.

Dr. Brotman wrote that increasing D-dimer cutoffs for high-risk patients in the subgroups analyzed may spare some patients radiographic testing, but doing so carries an increased risk for diagnostic failure. Overall, “the important work by Stals and colleagues offers reassurance that modifying D-dimer thresholds according to age or pretest probability is safe enough for widespread practice, even in high-risk groups.”
 

Focus on single strategy ‘based on local needs’

“Several validated clinical decision tools, along with age or pretest probability adjusted D-dimer threshold are currently in use as diagnostic strategies for ruling out pulmonary embolism,” Dr. Pal said in an interview.

The current study is important because of limited data on the performance of these strategies in specific subgroups of patients whose risk of PE may differ from the overall patient population, he noted.

“Different diagnostic strategies for PE have a variable performance in patients with differences of age, active cancer, and history of VTE,” said Dr. Pal. “However, in this study, no clear preference for one strategy over others could be established for these subgroups, and clinicians should continue to follow institution-specific guidance.

“A single strategy should be adopted at each institution based on local needs and used as the standard of care until further data are available,” he said.

“The use of D-dimer to rule out PE, either with fixed threshold or age-adjusted thresholds, can be confounded in clinical settings by other comorbid conditions such as sepsis, recent surgery, and more recently, COVID-19,” he said.

“Since the findings of this study do not show a clear benefit of one diagnostic strategy over others in the analyzed subgroups of patients, further prospective head-to-head comparison among the subgroups of interest would be helpful to guide clinical decision making,” Dr. Pal added.
 

YEARS-specific study supports D-dimer safety and value

A recent paper published in JAMA supported the results of the meta-analysis. In that study, Yonathan Freund, MD, of Sorbonne Université, Paris, and colleagues focused on the YEARS strategy combined with age-adjusted D-dimer thresholds as a way to rule out PE in PERC-positive ED patients.

The authors of this paper randomized 18 EDs to either a protocol of intervention followed by control, or control followed by intervention. The study population included 726 patients in the intervention group and 688 in the control group.

The intervention strategy to rule out PE consisted of assessing the YEARS criteria and D-dimer testing. PE was ruled out in patients with no YEARS criteria and a D-dimer level below 1,000 ng/mL and in patients with one or more YEARS criteria and D-dimers below an age-adjusted threshold (defined as age times 10 ng/mL in patients aged 50 years and older).

The control strategy consisted of D-dimer testing for all patients with the threshold at age-adjusted levels; D-dimers about these levels prompted chest imaging.

Overall, the risk of a missed VTE at 3 months was noninferior between the groups (0.15% in the intervention group and 0.80% in the controls).

“The intervention was associated with a statistically significant reduction in chest imaging use,” the researchers wrote.

This study’s findings were limited by randomization at the center level, rather than the patient level, and the use of imaging on some patients despite negative D-dimer tests, the researchers wrote. However, their findings support those of previous studies and especially support the safety of the intervention, in an emergency medicine setting, as no PEs occurred in patients with a YEARS score of zero who underwent the intervention.
 

Downsides to applying algorithms to every patient explained

In an editorial accompanying the JAMA study, Marcel Levi, MD, and Nick van Es, MD, of Amsterdam University Medical Center, emphasized the challenges of diagnosing PE given that many patients present with nonspecific clinical manifestations and without typical signs and symptoms. High-resolution CT pulmonary angiography allows for a fast and easy diagnosis in an emergency setting. However, efforts are ongoing to develop alternative strategies that avoid unnecessary scanning for potential PE patients, many of whom have alternative diagnoses such as pulmonary infections, cardiac conditions, pleural disease, or musculoskeletal problems.

On review of the JAMA study using the YEARS rule with adjusted D-dimer thresholds, the editorialists noted that the data were robust and indicated a 10% reduction in chest imaging. They also emphasized the potential to overwhelm busy clinicians with more algorithms.

“Blindly applying algorithms to every patient may be less appropriate or even undesirable in specific situations in which deviation from the rules on clinical grounds is indicated,” but a complex imaging approach may be time consuming and challenging in the acute setting, and a simple algorithm may be safe and efficient in many cases, they wrote. “From a patient perspective, a negative diagnostic algorithm for pulmonary embolism does not diminish the physician’s obligation to consider other diagnoses that explain the symptoms, for which chest CT scans may still be needed and helpful.”

The Annals of Internal Medicine study was supported by the Dutch Research Council. The JAMA study was supported by the French Health Ministry. Dr. Stals, Dr. Freund, Dr. Pal, Dr. Levi, and Dr. van Es had no financial conflicts to disclose.

Adapted D-dimer thresholds based on pretest probability were effective for ruling out pulmonary embolism (PE) in subgroups of high-risk individuals without the use of imaging in a review of data.

In a patient suspected to have a PE, “diagnosis is made radiographically, usually with CT pulmonary angiogram, or V/Q scan,” Suman Pal, MD, of the University of New Mexico, Albuquerque, said in an interview.

“Validated clinical decision tools such as Wells’ score or Geneva score may be used to identify patients at low pretest probability of PE who may initially get a D-dimer level check, followed by imaging only if D-dimer level is elevated,” explained Dr. Pal, who was not involved with the new research, which was published in the Annals of Internal Medicine.

According to the authors of the new paper, while current diagnostic strategies in patients with suspected PE include use of a validated clinical decision rule (CDR) and D-dimer testing to rule out PE without imaging tests, the effectiveness of D-dimer tests in older patients, inpatients, cancer patients, and other high-risk groups has not been well-studied.

Lead author of the paper, Milou A.M. Stals, MD, and colleagues said their goal was to evaluate the safety and efficiency of the Wells rule and revised Geneva score in combination with D-dimer tests, and also the YEARS algorithm for D-dimer thresholds, in their paper.

Dr. Stals, of Leiden (the Netherlands) University Medical Center, and the coinvestigators conducted an international systemic review and individual patient data meta-analysis that included 16 studies and 20,553 patients, with all studies having been published between Jan. 1, 1995, and Jan. 1, 2021. Their primary outcomes were the safety and efficiency of each of these three strategies.

In the review, the researchers defined safety as the 3-month incidence of venous thromboembolism after PE was ruled out without imaging at baseline. They defined efficiency as the proportion patients for whom PE was ruled out based on D-dimer thresholds without imaging.

Overall, efficiency was highest in the subset of patients aged younger than 40 years, ranging from 47% to 68% in this group. Efficiency was lowest in patients aged 80 years and older (6.0%-23%), and in patients with cancer (9.6%-26%).

The efficiency was higher when D-dimer thresholds based on pretest probability were used, compared with when fixed or age-adjusted D-dimer thresholds were used.

The key finding was the significant variability in performance of the diagnostic strategies, the researchers said.

“The predicted failure rate was generally highest for strategies incorporating adapted D-dimer thresholds. However, at the same time, predicted overall efficiency was substantially higher with these strategies versus strategies with a fixed D-dimer threshold as well,” they said. Given that the benefits of each of the three diagnostic strategies depends on their correct application, the researchers recommended that an individual hospitalist choose one strategy for their institution.

“Whether clinicians should rely on the Wells rule, the YEARS algorithm, or the revised Geneva score becomes a matter of local preference and experience,” Dr. Stals and colleagues wrote.

The study findings were limited by several factors including between-study differences in scoring predictors and D-dimer assays. Another limitation was that differential verification biases for classifying fatal events and PE may have contributed to overestimation of failure rates of the adapted D-dimer thresholds.

Strengths of the study included its large sample size and original data on pretest probability, and that data support the use of any of the three strategies for ruling out PE in the identified subgroups without the need for imaging tests, the authors wrote.

“Pending the results of ongoing diagnostic randomized trials, physicians and guideline committees should balance the interlink between safety and efficiency of available diagnostic strategies,” they concluded.

Adapted D-dimer benefits some patients

“Clearly, increasing the D-dimer cutoff will lower the number of patients who require radiographic imaging (improved specificity), but this comes with a risk for missing PE (lower sensitivity). Is this risk worth taking?” Daniel J. Brotman, MD, of Johns Hopkins University, Baltimore, asked in an editorial accompanying the new study.

Dr. Brotman was not surprised by the study findings.

“Conditions that predispose to thrombosis through activated hemostasis – such as advanced age, cancer, inflammation, prolonged hospitalization, and trauma – drive D-dimer levels higher independent of the presence or absence of radiographically apparent thrombosis,” he said. However, these patients are unlikely to have normal D-dimer levels regardless of the cutoff used.

Adapted D-dimer cutoffs may benefit some patients, including those with contraindications or limited access to imaging, said Dr. Brotman. D-dimer may be used for risk stratification regardless of PE, since patients with marginally elevated D-dimers have better prognoses than those with higher D-dimer elevations, even if a small PE is missed.

Dr. Brotman wrote that increasing D-dimer cutoffs for high-risk patients in the subgroups analyzed may spare some patients radiographic testing, but doing so carries an increased risk for diagnostic failure. Overall, “the important work by Stals and colleagues offers reassurance that modifying D-dimer thresholds according to age or pretest probability is safe enough for widespread practice, even in high-risk groups.”
 

Focus on single strategy ‘based on local needs’

“Several validated clinical decision tools, along with age or pretest probability adjusted D-dimer threshold are currently in use as diagnostic strategies for ruling out pulmonary embolism,” Dr. Pal said in an interview.

The current study is important because of limited data on the performance of these strategies in specific subgroups of patients whose risk of PE may differ from the overall patient population, he noted.

“Different diagnostic strategies for PE have a variable performance in patients with differences of age, active cancer, and history of VTE,” said Dr. Pal. “However, in this study, no clear preference for one strategy over others could be established for these subgroups, and clinicians should continue to follow institution-specific guidance.

“A single strategy should be adopted at each institution based on local needs and used as the standard of care until further data are available,” he said.

“The use of D-dimer to rule out PE, either with fixed threshold or age-adjusted thresholds, can be confounded in clinical settings by other comorbid conditions such as sepsis, recent surgery, and more recently, COVID-19,” he said.

“Since the findings of this study do not show a clear benefit of one diagnostic strategy over others in the analyzed subgroups of patients, further prospective head-to-head comparison among the subgroups of interest would be helpful to guide clinical decision making,” Dr. Pal added.
 

YEARS-specific study supports D-dimer safety and value

A recent paper published in JAMA supported the results of the meta-analysis. In that study, Yonathan Freund, MD, of Sorbonne Université, Paris, and colleagues focused on the YEARS strategy combined with age-adjusted D-dimer thresholds as a way to rule out PE in PERC-positive ED patients.

The authors of this paper randomized 18 EDs to either a protocol of intervention followed by control, or control followed by intervention. The study population included 726 patients in the intervention group and 688 in the control group.

The intervention strategy to rule out PE consisted of assessing the YEARS criteria and D-dimer testing. PE was ruled out in patients with no YEARS criteria and a D-dimer level below 1,000 ng/mL and in patients with one or more YEARS criteria and D-dimers below an age-adjusted threshold (defined as age times 10 ng/mL in patients aged 50 years and older).

The control strategy consisted of D-dimer testing for all patients with the threshold at age-adjusted levels; D-dimers about these levels prompted chest imaging.

Overall, the risk of a missed VTE at 3 months was noninferior between the groups (0.15% in the intervention group and 0.80% in the controls).

“The intervention was associated with a statistically significant reduction in chest imaging use,” the researchers wrote.

This study’s findings were limited by randomization at the center level, rather than the patient level, and the use of imaging on some patients despite negative D-dimer tests, the researchers wrote. However, their findings support those of previous studies and especially support the safety of the intervention, in an emergency medicine setting, as no PEs occurred in patients with a YEARS score of zero who underwent the intervention.
 

Downsides to applying algorithms to every patient explained

In an editorial accompanying the JAMA study, Marcel Levi, MD, and Nick van Es, MD, of Amsterdam University Medical Center, emphasized the challenges of diagnosing PE given that many patients present with nonspecific clinical manifestations and without typical signs and symptoms. High-resolution CT pulmonary angiography allows for a fast and easy diagnosis in an emergency setting. However, efforts are ongoing to develop alternative strategies that avoid unnecessary scanning for potential PE patients, many of whom have alternative diagnoses such as pulmonary infections, cardiac conditions, pleural disease, or musculoskeletal problems.

On review of the JAMA study using the YEARS rule with adjusted D-dimer thresholds, the editorialists noted that the data were robust and indicated a 10% reduction in chest imaging. They also emphasized the potential to overwhelm busy clinicians with more algorithms.

“Blindly applying algorithms to every patient may be less appropriate or even undesirable in specific situations in which deviation from the rules on clinical grounds is indicated,” but a complex imaging approach may be time consuming and challenging in the acute setting, and a simple algorithm may be safe and efficient in many cases, they wrote. “From a patient perspective, a negative diagnostic algorithm for pulmonary embolism does not diminish the physician’s obligation to consider other diagnoses that explain the symptoms, for which chest CT scans may still be needed and helpful.”

The Annals of Internal Medicine study was supported by the Dutch Research Council. The JAMA study was supported by the French Health Ministry. Dr. Stals, Dr. Freund, Dr. Pal, Dr. Levi, and Dr. van Es had no financial conflicts to disclose.

Adapted D-dimer thresholds based on pretest probability were effective for ruling out pulmonary embolism (PE) in subgroups of high-risk individuals without the use of imaging in a review of data.

In a patient suspected to have a PE, “diagnosis is made radiographically, usually with CT pulmonary angiogram, or V/Q scan,” Suman Pal, MD, of the University of New Mexico, Albuquerque, said in an interview.

“Validated clinical decision tools such as Wells’ score or Geneva score may be used to identify patients at low pretest probability of PE who may initially get a D-dimer level check, followed by imaging only if D-dimer level is elevated,” explained Dr. Pal, who was not involved with the new research, which was published in the Annals of Internal Medicine.

According to the authors of the new paper, while current diagnostic strategies in patients with suspected PE include use of a validated clinical decision rule (CDR) and D-dimer testing to rule out PE without imaging tests, the effectiveness of D-dimer tests in older patients, inpatients, cancer patients, and other high-risk groups has not been well-studied.

Lead author of the paper, Milou A.M. Stals, MD, and colleagues said their goal was to evaluate the safety and efficiency of the Wells rule and revised Geneva score in combination with D-dimer tests, and also the YEARS algorithm for D-dimer thresholds, in their paper.

Dr. Stals, of Leiden (the Netherlands) University Medical Center, and the coinvestigators conducted an international systemic review and individual patient data meta-analysis that included 16 studies and 20,553 patients, with all studies having been published between Jan. 1, 1995, and Jan. 1, 2021. Their primary outcomes were the safety and efficiency of each of these three strategies.

In the review, the researchers defined safety as the 3-month incidence of venous thromboembolism after PE was ruled out without imaging at baseline. They defined efficiency as the proportion patients for whom PE was ruled out based on D-dimer thresholds without imaging.

Overall, efficiency was highest in the subset of patients aged younger than 40 years, ranging from 47% to 68% in this group. Efficiency was lowest in patients aged 80 years and older (6.0%-23%), and in patients with cancer (9.6%-26%).

The efficiency was higher when D-dimer thresholds based on pretest probability were used, compared with when fixed or age-adjusted D-dimer thresholds were used.

The key finding was the significant variability in performance of the diagnostic strategies, the researchers said.

“The predicted failure rate was generally highest for strategies incorporating adapted D-dimer thresholds. However, at the same time, predicted overall efficiency was substantially higher with these strategies versus strategies with a fixed D-dimer threshold as well,” they said. Given that the benefits of each of the three diagnostic strategies depends on their correct application, the researchers recommended that an individual hospitalist choose one strategy for their institution.

“Whether clinicians should rely on the Wells rule, the YEARS algorithm, or the revised Geneva score becomes a matter of local preference and experience,” Dr. Stals and colleagues wrote.

The study findings were limited by several factors including between-study differences in scoring predictors and D-dimer assays. Another limitation was that differential verification biases for classifying fatal events and PE may have contributed to overestimation of failure rates of the adapted D-dimer thresholds.

Strengths of the study included its large sample size and original data on pretest probability, and that data support the use of any of the three strategies for ruling out PE in the identified subgroups without the need for imaging tests, the authors wrote.

“Pending the results of ongoing diagnostic randomized trials, physicians and guideline committees should balance the interlink between safety and efficiency of available diagnostic strategies,” they concluded.

Adapted D-dimer benefits some patients

“Clearly, increasing the D-dimer cutoff will lower the number of patients who require radiographic imaging (improved specificity), but this comes with a risk for missing PE (lower sensitivity). Is this risk worth taking?” Daniel J. Brotman, MD, of Johns Hopkins University, Baltimore, asked in an editorial accompanying the new study.

Dr. Brotman was not surprised by the study findings.

“Conditions that predispose to thrombosis through activated hemostasis – such as advanced age, cancer, inflammation, prolonged hospitalization, and trauma – drive D-dimer levels higher independent of the presence or absence of radiographically apparent thrombosis,” he said. However, these patients are unlikely to have normal D-dimer levels regardless of the cutoff used.

Adapted D-dimer cutoffs may benefit some patients, including those with contraindications or limited access to imaging, said Dr. Brotman. D-dimer may be used for risk stratification regardless of PE, since patients with marginally elevated D-dimers have better prognoses than those with higher D-dimer elevations, even if a small PE is missed.

Dr. Brotman wrote that increasing D-dimer cutoffs for high-risk patients in the subgroups analyzed may spare some patients radiographic testing, but doing so carries an increased risk for diagnostic failure. Overall, “the important work by Stals and colleagues offers reassurance that modifying D-dimer thresholds according to age or pretest probability is safe enough for widespread practice, even in high-risk groups.”
 

Focus on single strategy ‘based on local needs’

“Several validated clinical decision tools, along with age or pretest probability adjusted D-dimer threshold are currently in use as diagnostic strategies for ruling out pulmonary embolism,” Dr. Pal said in an interview.

The current study is important because of limited data on the performance of these strategies in specific subgroups of patients whose risk of PE may differ from the overall patient population, he noted.

“Different diagnostic strategies for PE have a variable performance in patients with differences of age, active cancer, and history of VTE,” said Dr. Pal. “However, in this study, no clear preference for one strategy over others could be established for these subgroups, and clinicians should continue to follow institution-specific guidance.

“A single strategy should be adopted at each institution based on local needs and used as the standard of care until further data are available,” he said.

“The use of D-dimer to rule out PE, either with fixed threshold or age-adjusted thresholds, can be confounded in clinical settings by other comorbid conditions such as sepsis, recent surgery, and more recently, COVID-19,” he said.

“Since the findings of this study do not show a clear benefit of one diagnostic strategy over others in the analyzed subgroups of patients, further prospective head-to-head comparison among the subgroups of interest would be helpful to guide clinical decision making,” Dr. Pal added.
 

YEARS-specific study supports D-dimer safety and value

A recent paper published in JAMA supported the results of the meta-analysis. In that study, Yonathan Freund, MD, of Sorbonne Université, Paris, and colleagues focused on the YEARS strategy combined with age-adjusted D-dimer thresholds as a way to rule out PE in PERC-positive ED patients.

The authors of this paper randomized 18 EDs to either a protocol of intervention followed by control, or control followed by intervention. The study population included 726 patients in the intervention group and 688 in the control group.

The intervention strategy to rule out PE consisted of assessing the YEARS criteria and D-dimer testing. PE was ruled out in patients with no YEARS criteria and a D-dimer level below 1,000 ng/mL and in patients with one or more YEARS criteria and D-dimers below an age-adjusted threshold (defined as age times 10 ng/mL in patients aged 50 years and older).

The control strategy consisted of D-dimer testing for all patients with the threshold at age-adjusted levels; D-dimers about these levels prompted chest imaging.

Overall, the risk of a missed VTE at 3 months was noninferior between the groups (0.15% in the intervention group and 0.80% in the controls).

“The intervention was associated with a statistically significant reduction in chest imaging use,” the researchers wrote.

This study’s findings were limited by randomization at the center level, rather than the patient level, and the use of imaging on some patients despite negative D-dimer tests, the researchers wrote. However, their findings support those of previous studies and especially support the safety of the intervention, in an emergency medicine setting, as no PEs occurred in patients with a YEARS score of zero who underwent the intervention.
 

Downsides to applying algorithms to every patient explained

In an editorial accompanying the JAMA study, Marcel Levi, MD, and Nick van Es, MD, of Amsterdam University Medical Center, emphasized the challenges of diagnosing PE given that many patients present with nonspecific clinical manifestations and without typical signs and symptoms. High-resolution CT pulmonary angiography allows for a fast and easy diagnosis in an emergency setting. However, efforts are ongoing to develop alternative strategies that avoid unnecessary scanning for potential PE patients, many of whom have alternative diagnoses such as pulmonary infections, cardiac conditions, pleural disease, or musculoskeletal problems.

On review of the JAMA study using the YEARS rule with adjusted D-dimer thresholds, the editorialists noted that the data were robust and indicated a 10% reduction in chest imaging. They also emphasized the potential to overwhelm busy clinicians with more algorithms.

“Blindly applying algorithms to every patient may be less appropriate or even undesirable in specific situations in which deviation from the rules on clinical grounds is indicated,” but a complex imaging approach may be time consuming and challenging in the acute setting, and a simple algorithm may be safe and efficient in many cases, they wrote. “From a patient perspective, a negative diagnostic algorithm for pulmonary embolism does not diminish the physician’s obligation to consider other diagnoses that explain the symptoms, for which chest CT scans may still be needed and helpful.”

The Annals of Internal Medicine study was supported by the Dutch Research Council. The JAMA study was supported by the French Health Ministry. Dr. Stals, Dr. Freund, Dr. Pal, Dr. Levi, and Dr. van Es had no financial conflicts to disclose.

Apixaban appears to be safer and more effective than rivaroxaban for reducing risk of venous thromboembolism and bleeding, based on new research.

Recurrent venous thromboembolism (VTE) – a composite of pulmonary embolism and deep vein thrombosis – was the primary effectiveness outcome in the retrospective analysis of new-user data from almost 40,000 patients, which was published in Annals of Internal Medicine. Safety was evaluated through a composite of intracranial and gastrointestinal bleeding.

After a median follow-up of 102 days in the apixaban group and 105 days in the rivaroxaban group, apixaban demonstrated superiority for both primary outcomes.

These real-world findings may guide selection of initial anticoagulant therapy, reported lead author Ghadeer K. Dawwas, PhD, MSc, MBA, of the University of Pennsylvania, Philadelphia, and colleagues.

“Randomized clinical trials comparing apixaban with rivaroxaban in patients with VTE are under way (for example, COBRRA (NCT03266783),” the investigators wrote. “Until the results from these trials become available (The estimated completion date for COBRRA is December 2023.), observational studies that use existing data can provide evidence on the effectiveness and safety of these alternatives to inform clinical practice.”

In the new research, apixaban was associated with a 23% lower rate of recurrent VTE (hazard ratio, 0.77; 95% confidence interval, 0.69-0.87), including a 15% lower rate of deep vein thrombosis and a 41% lower rate of pulmonary embolism. Apixaban was associated with 40% fewer bleeding events (HR, 0.60; 95% CI, 0.53-0.69]), including a 40% lower rate of GI bleeding and a 46% lower rate of intracranial bleeding.

The study involved 37,236 patients with VTE, all of whom were diagnosed in at least one inpatient encounter and initiated direct oral anticoagulant (DOAC) therapy within 30 days, according to Optum’s deidentified Clinformatics Data Mart Database. Patients were evenly split into apixaban and rivaroxaban groups, with 18,618 individuals in each. Propensity score matching was used to minimize differences in baseline characteristics.

Apixaban was associated with an absolute reduction in recurrent VTE of 0.6% and 1.1% over 2 and 6 months, respectively, as well as reductions in bleeding of 1.1% and 1.5% over the same respective time periods.

The investigators noted that these findings were maintained in various sensitivity and subgroup analyses, including a model in which patients with VTE who had transient risk factors were compared with VTE patients exhibiting chronic risk factors.

“These findings suggest that apixaban has superior effectiveness and safety, compared with rivaroxaban and may provide guidance to clinicians and patients regarding selection of an anticoagulant for treatment of VTE,” Dr. Dawwas and colleagues concluded.

Study may have missed some nuance in possible outcomes, according to vascular surgeon

Thomas Wakefield, MD, a vascular surgeon and a professor of surgery at the University of Michigan Health Frankel Cardiovascular Center, Ann Arbor, generally agreed with the investigators’ conclusion, although he noted that DOAC selection may also be influenced by other considerations.

“The results of this study suggest that, when choosing an agent for an individual patient, apixaban does appear to have an advantage over rivaroxaban related to recurrent VTE and bleeding,” Dr. Wakefield said in an interview. “One must keep in mind that these are not the only factors that are considered when choosing an agent and these are not the only two DOACs available. For example, rivaroxaban is given once per day while apixaban is given twice per day, and rivaroxaban has been shown to be successful in the treatment of other thrombotic disorders.”

Dr. Wakefield also pointed out that the study may have missed some nuance in possible outcomes.

“The current study looked at severe outcomes that resulted in inpatient hospitalization, so the generalization to strictly outpatient treatment and less severe outcomes cannot be inferred,” he said.

Damon E. Houghton, MD, of the department of medicine and a consultant in the department of vascular medicine and hematology at Mayo Clinic, Rochester, Minn., called the study a “very nice analysis,” highlighting the large sample size.

“The results are not a reason to abandon rivaroxaban altogether, but do suggest that, when otherwise appropriate for a patient, apixaban should be the first choice,” Dr. Houghton said in a written comment. “Hopefully this analysis will encourage more payers to create financial incentives that facilitate the use of apixaban in more patients.”

Randomized trial needed, says hematologist

Colleen Edwards, MD, of the departments of medicine, hematology, and medical oncology, at the Icahn School of Medicine at Mount Sinai, New York, had a more guarded view of the findings than Dr. Wakefield and Dr. Houghton.

“[The investigators] certainly seem to be doing a lot of statistical gymnastics in this paper,” Dr. Edwards said in an interview. “They used all kinds of surrogates in place of real data that you would get from a randomized trial.”

For example, Dr. Edwards noted the use of prescription refills as a surrogate for medication adherence, and emphasized that inpatient observational data may not reflect outpatient therapy.

“Inpatients are constantly missing their medicines all the time,” she said. “They’re holding it for procedures, they’re NPO, they’re off the floor, so they missed their medicine. So it’s just a very different patient population than the outpatient population, which is where venous thromboembolism is treated now, by and large.”

Although Dr. Edwards suggested that the findings might guide treatment selection “a little bit,” she noted that insurance constraints and costs play a greater role, and ultimately concluded that a randomized trial is needed to materially alter clinical decision-making.

“I think we really have to wait for randomized trial before we abandon our other choices,” she said.

The investigators disclosed relationships with Merck, Celgene, UCB, and others. Dr. Wakefield reported awaiting disclosures. Dr. Houghton and Dr. Edwards reported no relevant conflicts of interest.

Apixaban appears to be safer and more effective than rivaroxaban for reducing risk of venous thromboembolism and bleeding, based on new research.

Recurrent venous thromboembolism (VTE) – a composite of pulmonary embolism and deep vein thrombosis – was the primary effectiveness outcome in the retrospective analysis of new-user data from almost 40,000 patients, which was published in Annals of Internal Medicine. Safety was evaluated through a composite of intracranial and gastrointestinal bleeding.

After a median follow-up of 102 days in the apixaban group and 105 days in the rivaroxaban group, apixaban demonstrated superiority for both primary outcomes.

These real-world findings may guide selection of initial anticoagulant therapy, reported lead author Ghadeer K. Dawwas, PhD, MSc, MBA, of the University of Pennsylvania, Philadelphia, and colleagues.

“Randomized clinical trials comparing apixaban with rivaroxaban in patients with VTE are under way (for example, COBRRA (NCT03266783),” the investigators wrote. “Until the results from these trials become available (The estimated completion date for COBRRA is December 2023.), observational studies that use existing data can provide evidence on the effectiveness and safety of these alternatives to inform clinical practice.”

In the new research, apixaban was associated with a 23% lower rate of recurrent VTE (hazard ratio, 0.77; 95% confidence interval, 0.69-0.87), including a 15% lower rate of deep vein thrombosis and a 41% lower rate of pulmonary embolism. Apixaban was associated with 40% fewer bleeding events (HR, 0.60; 95% CI, 0.53-0.69]), including a 40% lower rate of GI bleeding and a 46% lower rate of intracranial bleeding.

The study involved 37,236 patients with VTE, all of whom were diagnosed in at least one inpatient encounter and initiated direct oral anticoagulant (DOAC) therapy within 30 days, according to Optum’s deidentified Clinformatics Data Mart Database. Patients were evenly split into apixaban and rivaroxaban groups, with 18,618 individuals in each. Propensity score matching was used to minimize differences in baseline characteristics.

Apixaban was associated with an absolute reduction in recurrent VTE of 0.6% and 1.1% over 2 and 6 months, respectively, as well as reductions in bleeding of 1.1% and 1.5% over the same respective time periods.

The investigators noted that these findings were maintained in various sensitivity and subgroup analyses, including a model in which patients with VTE who had transient risk factors were compared with VTE patients exhibiting chronic risk factors.

“These findings suggest that apixaban has superior effectiveness and safety, compared with rivaroxaban and may provide guidance to clinicians and patients regarding selection of an anticoagulant for treatment of VTE,” Dr. Dawwas and colleagues concluded.

Study may have missed some nuance in possible outcomes, according to vascular surgeon

Thomas Wakefield, MD, a vascular surgeon and a professor of surgery at the University of Michigan Health Frankel Cardiovascular Center, Ann Arbor, generally agreed with the investigators’ conclusion, although he noted that DOAC selection may also be influenced by other considerations.

“The results of this study suggest that, when choosing an agent for an individual patient, apixaban does appear to have an advantage over rivaroxaban related to recurrent VTE and bleeding,” Dr. Wakefield said in an interview. “One must keep in mind that these are not the only factors that are considered when choosing an agent and these are not the only two DOACs available. For example, rivaroxaban is given once per day while apixaban is given twice per day, and rivaroxaban has been shown to be successful in the treatment of other thrombotic disorders.”

Dr. Wakefield also pointed out that the study may have missed some nuance in possible outcomes.

“The current study looked at severe outcomes that resulted in inpatient hospitalization, so the generalization to strictly outpatient treatment and less severe outcomes cannot be inferred,” he said.

Damon E. Houghton, MD, of the department of medicine and a consultant in the department of vascular medicine and hematology at Mayo Clinic, Rochester, Minn., called the study a “very nice analysis,” highlighting the large sample size.

“The results are not a reason to abandon rivaroxaban altogether, but do suggest that, when otherwise appropriate for a patient, apixaban should be the first choice,” Dr. Houghton said in a written comment. “Hopefully this analysis will encourage more payers to create financial incentives that facilitate the use of apixaban in more patients.”

Randomized trial needed, says hematologist

Colleen Edwards, MD, of the departments of medicine, hematology, and medical oncology, at the Icahn School of Medicine at Mount Sinai, New York, had a more guarded view of the findings than Dr. Wakefield and Dr. Houghton.

“[The investigators] certainly seem to be doing a lot of statistical gymnastics in this paper,” Dr. Edwards said in an interview. “They used all kinds of surrogates in place of real data that you would get from a randomized trial.”

For example, Dr. Edwards noted the use of prescription refills as a surrogate for medication adherence, and emphasized that inpatient observational data may not reflect outpatient therapy.

“Inpatients are constantly missing their medicines all the time,” she said. “They’re holding it for procedures, they’re NPO, they’re off the floor, so they missed their medicine. So it’s just a very different patient population than the outpatient population, which is where venous thromboembolism is treated now, by and large.”

Although Dr. Edwards suggested that the findings might guide treatment selection “a little bit,” she noted that insurance constraints and costs play a greater role, and ultimately concluded that a randomized trial is needed to materially alter clinical decision-making.

“I think we really have to wait for randomized trial before we abandon our other choices,” she said.

The investigators disclosed relationships with Merck, Celgene, UCB, and others. Dr. Wakefield reported awaiting disclosures. Dr. Houghton and Dr. Edwards reported no relevant conflicts of interest.

Apixaban appears to be safer and more effective than rivaroxaban for reducing risk of venous thromboembolism and bleeding, based on new research.

Recurrent venous thromboembolism (VTE) – a composite of pulmonary embolism and deep vein thrombosis – was the primary effectiveness outcome in the retrospective analysis of new-user data from almost 40,000 patients, which was published in Annals of Internal Medicine. Safety was evaluated through a composite of intracranial and gastrointestinal bleeding.

After a median follow-up of 102 days in the apixaban group and 105 days in the rivaroxaban group, apixaban demonstrated superiority for both primary outcomes.

These real-world findings may guide selection of initial anticoagulant therapy, reported lead author Ghadeer K. Dawwas, PhD, MSc, MBA, of the University of Pennsylvania, Philadelphia, and colleagues.

“Randomized clinical trials comparing apixaban with rivaroxaban in patients with VTE are under way (for example, COBRRA (NCT03266783),” the investigators wrote. “Until the results from these trials become available (The estimated completion date for COBRRA is December 2023.), observational studies that use existing data can provide evidence on the effectiveness and safety of these alternatives to inform clinical practice.”

In the new research, apixaban was associated with a 23% lower rate of recurrent VTE (hazard ratio, 0.77; 95% confidence interval, 0.69-0.87), including a 15% lower rate of deep vein thrombosis and a 41% lower rate of pulmonary embolism. Apixaban was associated with 40% fewer bleeding events (HR, 0.60; 95% CI, 0.53-0.69]), including a 40% lower rate of GI bleeding and a 46% lower rate of intracranial bleeding.

The study involved 37,236 patients with VTE, all of whom were diagnosed in at least one inpatient encounter and initiated direct oral anticoagulant (DOAC) therapy within 30 days, according to Optum’s deidentified Clinformatics Data Mart Database. Patients were evenly split into apixaban and rivaroxaban groups, with 18,618 individuals in each. Propensity score matching was used to minimize differences in baseline characteristics.

Apixaban was associated with an absolute reduction in recurrent VTE of 0.6% and 1.1% over 2 and 6 months, respectively, as well as reductions in bleeding of 1.1% and 1.5% over the same respective time periods.

The investigators noted that these findings were maintained in various sensitivity and subgroup analyses, including a model in which patients with VTE who had transient risk factors were compared with VTE patients exhibiting chronic risk factors.

“These findings suggest that apixaban has superior effectiveness and safety, compared with rivaroxaban and may provide guidance to clinicians and patients regarding selection of an anticoagulant for treatment of VTE,” Dr. Dawwas and colleagues concluded.

Study may have missed some nuance in possible outcomes, according to vascular surgeon

Thomas Wakefield, MD, a vascular surgeon and a professor of surgery at the University of Michigan Health Frankel Cardiovascular Center, Ann Arbor, generally agreed with the investigators’ conclusion, although he noted that DOAC selection may also be influenced by other considerations.

“The results of this study suggest that, when choosing an agent for an individual patient, apixaban does appear to have an advantage over rivaroxaban related to recurrent VTE and bleeding,” Dr. Wakefield said in an interview. “One must keep in mind that these are not the only factors that are considered when choosing an agent and these are not the only two DOACs available. For example, rivaroxaban is given once per day while apixaban is given twice per day, and rivaroxaban has been shown to be successful in the treatment of other thrombotic disorders.”

Dr. Wakefield also pointed out that the study may have missed some nuance in possible outcomes.

“The current study looked at severe outcomes that resulted in inpatient hospitalization, so the generalization to strictly outpatient treatment and less severe outcomes cannot be inferred,” he said.

Damon E. Houghton, MD, of the department of medicine and a consultant in the department of vascular medicine and hematology at Mayo Clinic, Rochester, Minn., called the study a “very nice analysis,” highlighting the large sample size.

“The results are not a reason to abandon rivaroxaban altogether, but do suggest that, when otherwise appropriate for a patient, apixaban should be the first choice,” Dr. Houghton said in a written comment. “Hopefully this analysis will encourage more payers to create financial incentives that facilitate the use of apixaban in more patients.”

Randomized trial needed, says hematologist

Colleen Edwards, MD, of the departments of medicine, hematology, and medical oncology, at the Icahn School of Medicine at Mount Sinai, New York, had a more guarded view of the findings than Dr. Wakefield and Dr. Houghton.

“[The investigators] certainly seem to be doing a lot of statistical gymnastics in this paper,” Dr. Edwards said in an interview. “They used all kinds of surrogates in place of real data that you would get from a randomized trial.”

For example, Dr. Edwards noted the use of prescription refills as a surrogate for medication adherence, and emphasized that inpatient observational data may not reflect outpatient therapy.

“Inpatients are constantly missing their medicines all the time,” she said. “They’re holding it for procedures, they’re NPO, they’re off the floor, so they missed their medicine. So it’s just a very different patient population than the outpatient population, which is where venous thromboembolism is treated now, by and large.”

Although Dr. Edwards suggested that the findings might guide treatment selection “a little bit,” she noted that insurance constraints and costs play a greater role, and ultimately concluded that a randomized trial is needed to materially alter clinical decision-making.

“I think we really have to wait for randomized trial before we abandon our other choices,” she said.

The investigators disclosed relationships with Merck, Celgene, UCB, and others. Dr. Wakefield reported awaiting disclosures. Dr. Houghton and Dr. Edwards reported no relevant conflicts of interest.

The plasma D-dimer assay has been used, along with clinical prediction scores, to rule out pulmonary embolism (PE) in critically ill patients for decades, but a new study suggests it may not be the right test to use in hospitalized COVID-19 patients.

The results showed that all hospitalized patients with COVID-19 and radiographic evidence of PE had plasma D-dimer levels of 0.05 mcg/mL or greater, the cutoff point for the diagnosis.

“If using D-dimer to exclude patients with PE, the increased values we found among 92.3% of patients suggest that this assay would be less useful than in the populations in which it was originally validated, among which a minority of patients had increased D-dimer values,” the authors write. “Setting higher D-dimer thresholds was associated with improved specificity at the cost of an increased false-negative rate that could be associated with an unacceptable patient safety risk.”

The inclusion of patients with D-dimer and computed tomography pulmonary angiography (CTPA) was necessary to estimate diagnostic performance, they note, but “this may have introduced selection bias by excluding patients unable to undergo CTPA.”

“Nonetheless, given the high pretest probability of PE and low specificity observed in this and other studies, these results suggest that use of D-dimer levels to exclude PE among patients hospitalized with COVID-19 may be inappropriate and have limited clinical utility,” they conclude.

Led by Constantine N. Logothetis, MD, from Morsani College of Medicine, University of South Florida, Tampa, the study was published online Oct. 8 as a Research Letter in JAMA Network Open.
 

Uncertain utility

The authors note that the availability of D-dimer samples routinely collected from hospitalized COVID-19 patients – as well as the heterogeneity of early, smaller studies – generated uncertainty about the utility of this assay.

This uncertainty prompted them to test the diagnostic accuracy of the D-dimer assay among a sample of 1,541 patients who were hospitalized with COVID-19 at their institution between January 2020 and February 2021 for a possible PE.

They compared plasma D-dimer concentrations with CTPA, the criterion standard for diagnosing PE, in 287 of those patients.

Overall, 118 patients (41.1%) required care in the ICU, and 27 patients (9.4%) died during hospitalization.

The investigators looked at the ability of plasma D-dimer levels collected on the same day as CTPA to diagnose PE.

Thirty-seven patients (12.9%) had radiographic evidence of PE, and 250 patients (87.1%) did not.

Overall, the vast majority of patients (92.3%; n = 265 patients) had plasma D-dimer levels of 0.05 mcg/mL or more, including all patients with PE and 225 of 250 patients without PE (91.2%).

The median D-dimer values were 1.0 mcg/mL for 250 patients without PE and 6.1 mcg/mL for 37 patients with PE.

D-dimer values ranged from 0.2 mcg/mL to 128 mcg/mL among patients without PE, and from 0.5 mcg/mL to more than 10,000 mcg/mL among patients with PE. Patients without PE had statistically significantly decreased mean D-dimer values (8.7 mcg/mL vs. 1.2 mcg/mL; P < .001).

A D-dimer concentration of 0.05 mcg/mL was associated with a sensitivity of 100%, specificity of 8.8%, negative predictive value (NPV) of 100%, positive predictive value (PPV) of 13.9%, and a negative likelihood ratio (NLR) of less than 0.1.

The age-adjusted threshold was associated with a sensitivity of 94.6%, specificity of 22.8%, NPV of 96.6%, PPV of 13.9%, and NLR of 0.24.

The authors note that all hospitalized patients with COVID-19 and radiographic evidence of PE had plasma D-dimer levels of 0.05 mcg/mL or greater.
 

D-dimer in VTE may not extrapolate to COVID-19

“The D-dimer test, which is a measure of circulating byproducts of blood clot dissolution, has long been incorporated into diagnostic algorithms for venous thromboembolic [VTE] disease, including deep vein thrombosis and pulmonary embolism. It is uncertain whether this diagnostic use of D-dimer testing can be extrapolated to the context of COVID-19 – an illness we now understand to be associated itself with intravascular thrombosis and fibrinolysis,” Matthew Tomey, MD, a cardiologist at Mount Sinai Morningside, New York, said in an interview.

“The authors of this study sought to evaluate the test characteristics of the D-dimer assay for diagnosis of pulmonary embolism in a consecutive series of 287 hospitalized patients with COVID-19 who underwent computed tomography pulmonary angiography (CTPA). This was a selected group of patients representing less than 20% of the 1,541 patients screened. Exclusion of data on the more than 80% of screened patients who did not undergo CTPA is a significant limitation of the study,” Dr. Tomey said.

“In the highly selected, small cohort studied, representing a group of patients at high pretest probability of pulmonary embolism, there was no patient with pulmonary embolism who had a D-dimer value less than 0.5 mcg/mL. Yet broad ranges of D-dimer values were observed in COVID-19 patients with (0.5 to >10,000 mcg/mL) and without (0.2 to 128 mcg/mL) pulmonary embolism,” he added.

Based on the presented data, it is likely true that very low levels of D-dimer decrease the likelihood of finding a pulmonary embolus on a CTPA, if it is performed, Dr. Tomey noted.

“Yet the data confirm that a wide range of D-dimer values can be observed in COVID-19 patients with or without pulmonary embolism. It is not clear at this time that D-dimer levels should be used as gatekeepers to diagnostic imaging studies such as CTPA when pretest suspicion of pulmonary embolism is high,” he said.

“This issue becomes relevant as we consider evolving data on use of anticoagulation in treatment of hospitalized patients with COVID-19. We learned this year that in critically ill patients hospitalized with COVID-19, routine therapeutic anticoagulation (with heparin) was not beneficial and potentially harmful when compared with usual thromboprophylaxis,” he concluded.

“As we strive to balance competing risks of bleeding and thrombosis, accurate diagnosis of pulmonary embolism is important to guide decision-making about therapeutic anticoagulation, including in COVID-19.”

Dr. Logothetis and Dr. Tomey have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

The plasma D-dimer assay has been used, along with clinical prediction scores, to rule out pulmonary embolism (PE) in critically ill patients for decades, but a new study suggests it may not be the right test to use in hospitalized COVID-19 patients.

The results showed that all hospitalized patients with COVID-19 and radiographic evidence of PE had plasma D-dimer levels of 0.05 mcg/mL or greater, the cutoff point for the diagnosis.

“If using D-dimer to exclude patients with PE, the increased values we found among 92.3% of patients suggest that this assay would be less useful than in the populations in which it was originally validated, among which a minority of patients had increased D-dimer values,” the authors write. “Setting higher D-dimer thresholds was associated with improved specificity at the cost of an increased false-negative rate that could be associated with an unacceptable patient safety risk.”

The inclusion of patients with D-dimer and computed tomography pulmonary angiography (CTPA) was necessary to estimate diagnostic performance, they note, but “this may have introduced selection bias by excluding patients unable to undergo CTPA.”

“Nonetheless, given the high pretest probability of PE and low specificity observed in this and other studies, these results suggest that use of D-dimer levels to exclude PE among patients hospitalized with COVID-19 may be inappropriate and have limited clinical utility,” they conclude.

Led by Constantine N. Logothetis, MD, from Morsani College of Medicine, University of South Florida, Tampa, the study was published online Oct. 8 as a Research Letter in JAMA Network Open.
 

Uncertain utility

The authors note that the availability of D-dimer samples routinely collected from hospitalized COVID-19 patients – as well as the heterogeneity of early, smaller studies – generated uncertainty about the utility of this assay.

This uncertainty prompted them to test the diagnostic accuracy of the D-dimer assay among a sample of 1,541 patients who were hospitalized with COVID-19 at their institution between January 2020 and February 2021 for a possible PE.

They compared plasma D-dimer concentrations with CTPA, the criterion standard for diagnosing PE, in 287 of those patients.

Overall, 118 patients (41.1%) required care in the ICU, and 27 patients (9.4%) died during hospitalization.

The investigators looked at the ability of plasma D-dimer levels collected on the same day as CTPA to diagnose PE.

Thirty-seven patients (12.9%) had radiographic evidence of PE, and 250 patients (87.1%) did not.

Overall, the vast majority of patients (92.3%; n = 265 patients) had plasma D-dimer levels of 0.05 mcg/mL or more, including all patients with PE and 225 of 250 patients without PE (91.2%).

The median D-dimer values were 1.0 mcg/mL for 250 patients without PE and 6.1 mcg/mL for 37 patients with PE.

D-dimer values ranged from 0.2 mcg/mL to 128 mcg/mL among patients without PE, and from 0.5 mcg/mL to more than 10,000 mcg/mL among patients with PE. Patients without PE had statistically significantly decreased mean D-dimer values (8.7 mcg/mL vs. 1.2 mcg/mL; P < .001).

A D-dimer concentration of 0.05 mcg/mL was associated with a sensitivity of 100%, specificity of 8.8%, negative predictive value (NPV) of 100%, positive predictive value (PPV) of 13.9%, and a negative likelihood ratio (NLR) of less than 0.1.

The age-adjusted threshold was associated with a sensitivity of 94.6%, specificity of 22.8%, NPV of 96.6%, PPV of 13.9%, and NLR of 0.24.

The authors note that all hospitalized patients with COVID-19 and radiographic evidence of PE had plasma D-dimer levels of 0.05 mcg/mL or greater.
 

D-dimer in VTE may not extrapolate to COVID-19

“The D-dimer test, which is a measure of circulating byproducts of blood clot dissolution, has long been incorporated into diagnostic algorithms for venous thromboembolic [VTE] disease, including deep vein thrombosis and pulmonary embolism. It is uncertain whether this diagnostic use of D-dimer testing can be extrapolated to the context of COVID-19 – an illness we now understand to be associated itself with intravascular thrombosis and fibrinolysis,” Matthew Tomey, MD, a cardiologist at Mount Sinai Morningside, New York, said in an interview.

“The authors of this study sought to evaluate the test characteristics of the D-dimer assay for diagnosis of pulmonary embolism in a consecutive series of 287 hospitalized patients with COVID-19 who underwent computed tomography pulmonary angiography (CTPA). This was a selected group of patients representing less than 20% of the 1,541 patients screened. Exclusion of data on the more than 80% of screened patients who did not undergo CTPA is a significant limitation of the study,” Dr. Tomey said.

“In the highly selected, small cohort studied, representing a group of patients at high pretest probability of pulmonary embolism, there was no patient with pulmonary embolism who had a D-dimer value less than 0.5 mcg/mL. Yet broad ranges of D-dimer values were observed in COVID-19 patients with (0.5 to >10,000 mcg/mL) and without (0.2 to 128 mcg/mL) pulmonary embolism,” he added.

Based on the presented data, it is likely true that very low levels of D-dimer decrease the likelihood of finding a pulmonary embolus on a CTPA, if it is performed, Dr. Tomey noted.

“Yet the data confirm that a wide range of D-dimer values can be observed in COVID-19 patients with or without pulmonary embolism. It is not clear at this time that D-dimer levels should be used as gatekeepers to diagnostic imaging studies such as CTPA when pretest suspicion of pulmonary embolism is high,” he said.

“This issue becomes relevant as we consider evolving data on use of anticoagulation in treatment of hospitalized patients with COVID-19. We learned this year that in critically ill patients hospitalized with COVID-19, routine therapeutic anticoagulation (with heparin) was not beneficial and potentially harmful when compared with usual thromboprophylaxis,” he concluded.

“As we strive to balance competing risks of bleeding and thrombosis, accurate diagnosis of pulmonary embolism is important to guide decision-making about therapeutic anticoagulation, including in COVID-19.”

Dr. Logothetis and Dr. Tomey have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

The plasma D-dimer assay has been used, along with clinical prediction scores, to rule out pulmonary embolism (PE) in critically ill patients for decades, but a new study suggests it may not be the right test to use in hospitalized COVID-19 patients.

The results showed that all hospitalized patients with COVID-19 and radiographic evidence of PE had plasma D-dimer levels of 0.05 mcg/mL or greater, the cutoff point for the diagnosis.

“If using D-dimer to exclude patients with PE, the increased values we found among 92.3% of patients suggest that this assay would be less useful than in the populations in which it was originally validated, among which a minority of patients had increased D-dimer values,” the authors write. “Setting higher D-dimer thresholds was associated with improved specificity at the cost of an increased false-negative rate that could be associated with an unacceptable patient safety risk.”

The inclusion of patients with D-dimer and computed tomography pulmonary angiography (CTPA) was necessary to estimate diagnostic performance, they note, but “this may have introduced selection bias by excluding patients unable to undergo CTPA.”

“Nonetheless, given the high pretest probability of PE and low specificity observed in this and other studies, these results suggest that use of D-dimer levels to exclude PE among patients hospitalized with COVID-19 may be inappropriate and have limited clinical utility,” they conclude.

Led by Constantine N. Logothetis, MD, from Morsani College of Medicine, University of South Florida, Tampa, the study was published online Oct. 8 as a Research Letter in JAMA Network Open.
 

Uncertain utility

The authors note that the availability of D-dimer samples routinely collected from hospitalized COVID-19 patients – as well as the heterogeneity of early, smaller studies – generated uncertainty about the utility of this assay.

This uncertainty prompted them to test the diagnostic accuracy of the D-dimer assay among a sample of 1,541 patients who were hospitalized with COVID-19 at their institution between January 2020 and February 2021 for a possible PE.

They compared plasma D-dimer concentrations with CTPA, the criterion standard for diagnosing PE, in 287 of those patients.

Overall, 118 patients (41.1%) required care in the ICU, and 27 patients (9.4%) died during hospitalization.

The investigators looked at the ability of plasma D-dimer levels collected on the same day as CTPA to diagnose PE.

Thirty-seven patients (12.9%) had radiographic evidence of PE, and 250 patients (87.1%) did not.

Overall, the vast majority of patients (92.3%; n = 265 patients) had plasma D-dimer levels of 0.05 mcg/mL or more, including all patients with PE and 225 of 250 patients without PE (91.2%).

The median D-dimer values were 1.0 mcg/mL for 250 patients without PE and 6.1 mcg/mL for 37 patients with PE.

D-dimer values ranged from 0.2 mcg/mL to 128 mcg/mL among patients without PE, and from 0.5 mcg/mL to more than 10,000 mcg/mL among patients with PE. Patients without PE had statistically significantly decreased mean D-dimer values (8.7 mcg/mL vs. 1.2 mcg/mL; P < .001).

A D-dimer concentration of 0.05 mcg/mL was associated with a sensitivity of 100%, specificity of 8.8%, negative predictive value (NPV) of 100%, positive predictive value (PPV) of 13.9%, and a negative likelihood ratio (NLR) of less than 0.1.

The age-adjusted threshold was associated with a sensitivity of 94.6%, specificity of 22.8%, NPV of 96.6%, PPV of 13.9%, and NLR of 0.24.

The authors note that all hospitalized patients with COVID-19 and radiographic evidence of PE had plasma D-dimer levels of 0.05 mcg/mL or greater.
 

D-dimer in VTE may not extrapolate to COVID-19

“The D-dimer test, which is a measure of circulating byproducts of blood clot dissolution, has long been incorporated into diagnostic algorithms for venous thromboembolic [VTE] disease, including deep vein thrombosis and pulmonary embolism. It is uncertain whether this diagnostic use of D-dimer testing can be extrapolated to the context of COVID-19 – an illness we now understand to be associated itself with intravascular thrombosis and fibrinolysis,” Matthew Tomey, MD, a cardiologist at Mount Sinai Morningside, New York, said in an interview.

“The authors of this study sought to evaluate the test characteristics of the D-dimer assay for diagnosis of pulmonary embolism in a consecutive series of 287 hospitalized patients with COVID-19 who underwent computed tomography pulmonary angiography (CTPA). This was a selected group of patients representing less than 20% of the 1,541 patients screened. Exclusion of data on the more than 80% of screened patients who did not undergo CTPA is a significant limitation of the study,” Dr. Tomey said.

“In the highly selected, small cohort studied, representing a group of patients at high pretest probability of pulmonary embolism, there was no patient with pulmonary embolism who had a D-dimer value less than 0.5 mcg/mL. Yet broad ranges of D-dimer values were observed in COVID-19 patients with (0.5 to >10,000 mcg/mL) and without (0.2 to 128 mcg/mL) pulmonary embolism,” he added.

Based on the presented data, it is likely true that very low levels of D-dimer decrease the likelihood of finding a pulmonary embolus on a CTPA, if it is performed, Dr. Tomey noted.

“Yet the data confirm that a wide range of D-dimer values can be observed in COVID-19 patients with or without pulmonary embolism. It is not clear at this time that D-dimer levels should be used as gatekeepers to diagnostic imaging studies such as CTPA when pretest suspicion of pulmonary embolism is high,” he said.

“This issue becomes relevant as we consider evolving data on use of anticoagulation in treatment of hospitalized patients with COVID-19. We learned this year that in critically ill patients hospitalized with COVID-19, routine therapeutic anticoagulation (with heparin) was not beneficial and potentially harmful when compared with usual thromboprophylaxis,” he concluded.

“As we strive to balance competing risks of bleeding and thrombosis, accurate diagnosis of pulmonary embolism is important to guide decision-making about therapeutic anticoagulation, including in COVID-19.”

Dr. Logothetis and Dr. Tomey have disclosed no relevant financial relationships.

A version of this article first appeared on Medscape.com.

A study that compared three types of direct oral anticoagulants (DOACs) found that rivaroxaban was associated with a much higher risk of overall and major gastrointestinal bleeding than apixaban or dabigatran.

The results, which were published in the Annals of Internal Medicine, could help guide DOAC selection for high-risk groups with a prior history of peptic ulcer disease or major GI bleeding, said lead study authors Arnar Bragi Ingason, MD and Einar S. Björnsson, MD, PhD, in an email.

DOACs treat conditions such as atrial fibrillation, venous thromboembolism, and ischemic stroke and are known to cause GI bleeding. Previous studies have suggested that rivaroxaban poses a higher GI-bleeding risk than other DOACs.

These studies, which used large administrative databases, “had an inherent risk of selection bias due to insurance status, age, and comorbidities due to their origin from insurance/administrative databases. In addition, they lacked phenotypic details on GI bleeding events,” said Dr. Björnsson and Dr. Ingason, who are both of Landspitali University Hospital, Reykjavik, Iceland,

Daily dosage may exacerbate risk

Rivaroxaban is administered as a single daily dose, compared with apixaban’s and dabigatran’s twice-daily regimens. “We hypothesized that this may lead to a greater variance in drug plasma concentration, making these patients more susceptible to GI bleeding,” the lead authors said.

Using data from the Icelandic Medicine Registry, a national database of outpatient prescription information, they compared rates of GI bleeding among new users of apixaban, dabigatran, and rivaroxaban from 2014 to 2019. Overall, 5,868 patients receiving one of the DOACs took part in the study. Among these participants, 3,217 received rivaroxaban, 2,157 received apixaban, and 494 received dabigatran. The researchers used inverse probability weighting, Kaplan–Meier survival estimates, and Cox regression to compare GI bleeding.

Compared with dabigatran, rivaroxaban was associated with a 63%-104% higher overall risk for GI bleeding and 39%-95% higher risk for major GI bleeding. Rivaroxaban also had a 40%-42% higher overall risk for GI bleeding and 49%-50% higher risk for major GI bleeding, compared with apixaban.

The investigators were surprised by the low rate of upper GI bleeding for dabigatran, compared with the other two drugs. “However, these results must be interpreted in the context that the dabigatran group was relatively small,” said Dr. Björnsson and Dr. Ingason via email.

Overall, the study cohort was small, compared with previous registry studies.

Investigators also did not account for account for socioeconomic status or lifestyle factors, such as alcohol consumption or smoking. “However, because the cost of all DOACs is similar in Iceland, selection bias due to socioeconomic status is unlikely,” the investigators reported in their paper. “We are currently working on comparing the rates of thromboembolisms and overall major bleeding events between the drugs,” the lead authors said.
 

Clinicians should consider location of bleeding

Though retrospective, the study by Ingason et. al. “is likely as close as is feasible to a randomized trial as is possible,” said Don C. Rockey, MD, a professor of medicine at the Medical University of South Carolina, Charleston, in an interview.

“From the clinician’s perspective, it is important to take away that there may be differences among the DOACs in terms of where in the GI tract the bleeding occurs,” said Dr. Rockey. In the study, the greatest differences appeared to be in the upper GI tract, with rivaroxaban outpacing apixaban and dabigatran. In patients who are at risk for upper GI bleeding, it may be reasonable to consider use of dabigatran or apixaban, he suggested.

“A limitation of the study is that it is likely underpowered overall,” said Dr. Rockey. It also wasn’t clear how many deaths occurred either directly from GI bleeding or as a complication of GI bleeding, he said.The study also didn’t differentiate major bleeding among DOACs specifically in the upper or lower GI tract, Dr. Rockey added.
 

Other studies yield similar results

Dr. Ingason and Dr. Björnsson said their work complements previous studies, and Neena S. Abraham, MD, MSc , who has conducted a similar investigation to the new study, agreed with that statement.

Data from the last 4 years overwhelmingly show that rivaroxaban is most likely to cause GI bleeding, said Dr. Abraham, professor of medicine and a consultant with Mayo Clinic’s division of gastroenterology and hepatology, in an interview.

A comparative safety study Dr. Abraham coauthored in 2017 of rivaroxaban, apixaban, and dabigatran in a much larger U.S. cohort of 372,380 patients revealed that rivaroxaban had the worst GI bleeding profile. Apixaban was 66% safer than rivaroxaban and 64% safer than dabigatran to prevent gastrointestinal bleeding.

“I believe our group was the first to conduct this study and show clinically significant differences in GI safety of the available direct oral anticoagulants,” she said. Other investigators have since published similar results, and the topic of the new study needs no further investigation, according to Dr. Abraham.

“It is time for physicians to choose a better choice when prescribing a direct oral anticoagulant to their atrial fibrillation patients, and that choice is not rivaroxaban,” she said.

The Icelandic Centre for Research and the Landspítali University Hospital Research Fund provided funds for this study. Dr. Ingason, Dr. Björnsson, Dr. Rockey, and Dr. Abraham reported no disclosures.

A study that compared three types of direct oral anticoagulants (DOACs) found that rivaroxaban was associated with a much higher risk of overall and major gastrointestinal bleeding than apixaban or dabigatran.

The results, which were published in the Annals of Internal Medicine, could help guide DOAC selection for high-risk groups with a prior history of peptic ulcer disease or major GI bleeding, said lead study authors Arnar Bragi Ingason, MD and Einar S. Björnsson, MD, PhD, in an email.

DOACs treat conditions such as atrial fibrillation, venous thromboembolism, and ischemic stroke and are known to cause GI bleeding. Previous studies have suggested that rivaroxaban poses a higher GI-bleeding risk than other DOACs.

These studies, which used large administrative databases, “had an inherent risk of selection bias due to insurance status, age, and comorbidities due to their origin from insurance/administrative databases. In addition, they lacked phenotypic details on GI bleeding events,” said Dr. Björnsson and Dr. Ingason, who are both of Landspitali University Hospital, Reykjavik, Iceland,

Daily dosage may exacerbate risk

Rivaroxaban is administered as a single daily dose, compared with apixaban’s and dabigatran’s twice-daily regimens. “We hypothesized that this may lead to a greater variance in drug plasma concentration, making these patients more susceptible to GI bleeding,” the lead authors said.

Using data from the Icelandic Medicine Registry, a national database of outpatient prescription information, they compared rates of GI bleeding among new users of apixaban, dabigatran, and rivaroxaban from 2014 to 2019. Overall, 5,868 patients receiving one of the DOACs took part in the study. Among these participants, 3,217 received rivaroxaban, 2,157 received apixaban, and 494 received dabigatran. The researchers used inverse probability weighting, Kaplan–Meier survival estimates, and Cox regression to compare GI bleeding.

Compared with dabigatran, rivaroxaban was associated with a 63%-104% higher overall risk for GI bleeding and 39%-95% higher risk for major GI bleeding. Rivaroxaban also had a 40%-42% higher overall risk for GI bleeding and 49%-50% higher risk for major GI bleeding, compared with apixaban.

The investigators were surprised by the low rate of upper GI bleeding for dabigatran, compared with the other two drugs. “However, these results must be interpreted in the context that the dabigatran group was relatively small,” said Dr. Björnsson and Dr. Ingason via email.

Overall, the study cohort was small, compared with previous registry studies.

Investigators also did not account for account for socioeconomic status or lifestyle factors, such as alcohol consumption or smoking. “However, because the cost of all DOACs is similar in Iceland, selection bias due to socioeconomic status is unlikely,” the investigators reported in their paper. “We are currently working on comparing the rates of thromboembolisms and overall major bleeding events between the drugs,” the lead authors said.
 

Clinicians should consider location of bleeding

Though retrospective, the study by Ingason et. al. “is likely as close as is feasible to a randomized trial as is possible,” said Don C. Rockey, MD, a professor of medicine at the Medical University of South Carolina, Charleston, in an interview.

“From the clinician’s perspective, it is important to take away that there may be differences among the DOACs in terms of where in the GI tract the bleeding occurs,” said Dr. Rockey. In the study, the greatest differences appeared to be in the upper GI tract, with rivaroxaban outpacing apixaban and dabigatran. In patients who are at risk for upper GI bleeding, it may be reasonable to consider use of dabigatran or apixaban, he suggested.

“A limitation of the study is that it is likely underpowered overall,” said Dr. Rockey. It also wasn’t clear how many deaths occurred either directly from GI bleeding or as a complication of GI bleeding, he said.The study also didn’t differentiate major bleeding among DOACs specifically in the upper or lower GI tract, Dr. Rockey added.
 

Other studies yield similar results

Dr. Ingason and Dr. Björnsson said their work complements previous studies, and Neena S. Abraham, MD, MSc , who has conducted a similar investigation to the new study, agreed with that statement.

Data from the last 4 years overwhelmingly show that rivaroxaban is most likely to cause GI bleeding, said Dr. Abraham, professor of medicine and a consultant with Mayo Clinic’s division of gastroenterology and hepatology, in an interview.

A comparative safety study Dr. Abraham coauthored in 2017 of rivaroxaban, apixaban, and dabigatran in a much larger U.S. cohort of 372,380 patients revealed that rivaroxaban had the worst GI bleeding profile. Apixaban was 66% safer than rivaroxaban and 64% safer than dabigatran to prevent gastrointestinal bleeding.

“I believe our group was the first to conduct this study and show clinically significant differences in GI safety of the available direct oral anticoagulants,” she said. Other investigators have since published similar results, and the topic of the new study needs no further investigation, according to Dr. Abraham.

“It is time for physicians to choose a better choice when prescribing a direct oral anticoagulant to their atrial fibrillation patients, and that choice is not rivaroxaban,” she said.

The Icelandic Centre for Research and the Landspítali University Hospital Research Fund provided funds for this study. Dr. Ingason, Dr. Björnsson, Dr. Rockey, and Dr. Abraham reported no disclosures.

A study that compared three types of direct oral anticoagulants (DOACs) found that rivaroxaban was associated with a much higher risk of overall and major gastrointestinal bleeding than apixaban or dabigatran.

The results, which were published in the Annals of Internal Medicine, could help guide DOAC selection for high-risk groups with a prior history of peptic ulcer disease or major GI bleeding, said lead study authors Arnar Bragi Ingason, MD and Einar S. Björnsson, MD, PhD, in an email.

DOACs treat conditions such as atrial fibrillation, venous thromboembolism, and ischemic stroke and are known to cause GI bleeding. Previous studies have suggested that rivaroxaban poses a higher GI-bleeding risk than other DOACs.

These studies, which used large administrative databases, “had an inherent risk of selection bias due to insurance status, age, and comorbidities due to their origin from insurance/administrative databases. In addition, they lacked phenotypic details on GI bleeding events,” said Dr. Björnsson and Dr. Ingason, who are both of Landspitali University Hospital, Reykjavik, Iceland,

Daily dosage may exacerbate risk

Rivaroxaban is administered as a single daily dose, compared with apixaban’s and dabigatran’s twice-daily regimens. “We hypothesized that this may lead to a greater variance in drug plasma concentration, making these patients more susceptible to GI bleeding,” the lead authors said.

Using data from the Icelandic Medicine Registry, a national database of outpatient prescription information, they compared rates of GI bleeding among new users of apixaban, dabigatran, and rivaroxaban from 2014 to 2019. Overall, 5,868 patients receiving one of the DOACs took part in the study. Among these participants, 3,217 received rivaroxaban, 2,157 received apixaban, and 494 received dabigatran. The researchers used inverse probability weighting, Kaplan–Meier survival estimates, and Cox regression to compare GI bleeding.

Compared with dabigatran, rivaroxaban was associated with a 63%-104% higher overall risk for GI bleeding and 39%-95% higher risk for major GI bleeding. Rivaroxaban also had a 40%-42% higher overall risk for GI bleeding and 49%-50% higher risk for major GI bleeding, compared with apixaban.

The investigators were surprised by the low rate of upper GI bleeding for dabigatran, compared with the other two drugs. “However, these results must be interpreted in the context that the dabigatran group was relatively small,” said Dr. Björnsson and Dr. Ingason via email.

Overall, the study cohort was small, compared with previous registry studies.

Investigators also did not account for account for socioeconomic status or lifestyle factors, such as alcohol consumption or smoking. “However, because the cost of all DOACs is similar in Iceland, selection bias due to socioeconomic status is unlikely,” the investigators reported in their paper. “We are currently working on comparing the rates of thromboembolisms and overall major bleeding events between the drugs,” the lead authors said.
 

Clinicians should consider location of bleeding

Though retrospective, the study by Ingason et. al. “is likely as close as is feasible to a randomized trial as is possible,” said Don C. Rockey, MD, a professor of medicine at the Medical University of South Carolina, Charleston, in an interview.

“From the clinician’s perspective, it is important to take away that there may be differences among the DOACs in terms of where in the GI tract the bleeding occurs,” said Dr. Rockey. In the study, the greatest differences appeared to be in the upper GI tract, with rivaroxaban outpacing apixaban and dabigatran. In patients who are at risk for upper GI bleeding, it may be reasonable to consider use of dabigatran or apixaban, he suggested.

“A limitation of the study is that it is likely underpowered overall,” said Dr. Rockey. It also wasn’t clear how many deaths occurred either directly from GI bleeding or as a complication of GI bleeding, he said.The study also didn’t differentiate major bleeding among DOACs specifically in the upper or lower GI tract, Dr. Rockey added.
 

Other studies yield similar results

Dr. Ingason and Dr. Björnsson said their work complements previous studies, and Neena S. Abraham, MD, MSc , who has conducted a similar investigation to the new study, agreed with that statement.

Data from the last 4 years overwhelmingly show that rivaroxaban is most likely to cause GI bleeding, said Dr. Abraham, professor of medicine and a consultant with Mayo Clinic’s division of gastroenterology and hepatology, in an interview.

A comparative safety study Dr. Abraham coauthored in 2017 of rivaroxaban, apixaban, and dabigatran in a much larger U.S. cohort of 372,380 patients revealed that rivaroxaban had the worst GI bleeding profile. Apixaban was 66% safer than rivaroxaban and 64% safer than dabigatran to prevent gastrointestinal bleeding.

“I believe our group was the first to conduct this study and show clinically significant differences in GI safety of the available direct oral anticoagulants,” she said. Other investigators have since published similar results, and the topic of the new study needs no further investigation, according to Dr. Abraham.

“It is time for physicians to choose a better choice when prescribing a direct oral anticoagulant to their atrial fibrillation patients, and that choice is not rivaroxaban,” she said.

The Icelandic Centre for Research and the Landspítali University Hospital Research Fund provided funds for this study. Dr. Ingason, Dr. Björnsson, Dr. Rockey, and Dr. Abraham reported no disclosures.

In patients with acute pulmonary embolism, using cutoff values other than 110 beats per minute might improve the prognostic value of heart rate at admission, a recent observational study suggests.

Courtesy of Mercy Medical Center

For identifying low-risk patients, a cutoff of 80 bpm increased the sensitivity of the simplified Pulmonary Embolism Severity Index (sPESI) from about 94% to nearly 99% among nonhypotensive patients with acute symptomatic pulmonary embolism (PE), according to results of the large, registry-based study.

Similarly, using a 140-bpm cutoff increased the specificity of the Bova score for identifying intermediate-high–risk patients from about 93% to 98% in the study, which was recently published in the journal CHEST.

“Although standard dichotomization of HR [i.e., HR less than 110 vs. greater than 110 bpm] may be useful for guideline recommendations, our results will allow for more accuracy regarding clinical decision-making,” wrote lead author Ana Jaureguízar, MD, of the University of Alcalá in Madrid, on behalf of the RIETE (Registro Informatizado de la Enfermedad TromboEmbólica) investigators.
 

Intuitive findings inform future research

These observational findings are intuitive and do at least have the potential to inform the design of future randomized clinical trials, according to Albert J. Polito, MD, chief of the division of pulmonary medicine and medical director for the lung center at Mercy Medical Center in Baltimore.

“In medicine, there is a spectrum of risk,” Dr. Polito said in an interview. “While we love our cutoffs, which in this case has traditionally always been that 110 beats per minute for heart rate, it makes sense that there would be some range of risks of bad outcomes.”

Building on the observations of the present study, subsequent prospective randomized studies could potentially aim to determine, for example, when thrombolytic therapy should be considered in nonhypotensive patients with acute PE and higher heart rates.

“It would not be easy to design, but it’s a straightforward question to ask whether patients with the highest heart rates are the ones who potentially might benefit the most from thrombolytic therapy,” Dr. Polito said.
 

Value of alternative HR cutoffs

Heart rate is a simple and easily available vital sign that is clearly linked to prognosis in patients with pulmonary embolism, authors of the RIETE registry study say in their report. Accordingly, a heart rate threshold of 110 bpm has made its way into scoring systems that seek to identify low-risk patients, such as the sPESI, and those focused on identifying higher-risk patients, such as the Bova score.

However, it has not been clear whether alternative HR cutoffs would improve upon the 110-bpm threshold, they added. At the low-risk end, more accurate scoring systems could optimize the selection of patients for home treatment, while at the intermediate-high–risk end, they could better select patients for close monitoring or advanced PE treatments.
 

Better granularity on heart rate risks?

To better define the prognostic value of different heart rate thresholds, investigators analyzed data from RIETE, a large, ongoing, multinational prospective registry including patients with objectively confirmed acute venous thromboembolism.

For 44,331 consecutive nonhypotensive symptomatic PEs, the overall rate of 30-day all-cause mortality was 5.1%, and the 30-day PE-related mortality was 1.9%, the authors report.

Significantly poorer outcomes were seen in patients with higher heart rates as compared to patients in the 80-99 bpm range, they also found. As compared to that reference range, odds ratios for 30-day all-cause death ranged from 1.5 for heart rates of 100-109, up to 2.4 for those with heart rates of 140 bpm or greater.

Likewise, patients with higher heart rates had a 1.7- to 2.4-fold greater risk of 30-day PE-related death as compared to the 80- to 99-bpm reference range, while patients with lower heart rates had lesser risk, the data published in CHEST show.
 

Toward refinement of prognostic scoring

Next, investigators sought to refine the prognostic scoring systems for low-risk PE (sPESI) and intermediate-high–risk PE (Bova).

For sPESI, they found that dropping the cutoff value from 110 to 100 bpm increased the sensitivity of the score from 93.4% to 95.3%. Going down even further to 80 bpm increased sensitivity to 98.8%, according to the report.

By going down from 110 to 80 bpm, the proportion of patients defined as low-risk dropped from 35% to 12%, according to the investigators.

For the Bova score, increasing the cutoff value from 110 to 120 bpm likewise increased specificity from 93.2% to 95%, while going up even further to 140 bpm increased specificity to 98.0%, the report shows.

In sensitivity analyses, the findings were not impacted by excluding younger patients, those who received reperfusion therapies, or those with atrial fibrillation, according to the study findings.
 

Potential implications for clinical practice

Taken together, these findings could serve as a resource to inform discussions regarding PE management that include whether home therapy or use of thrombolytic therapy is appropriate, investigators said in their report.

“For instance, among low-risk sPESI patients, those with borderline tachycardia [i.e., a heart rate between 100-109 bpm] might benefit from initial hospital observation for trending,” they wrote.

Dr. Jaureguízar reported no disclosures. One coinvestigator reported funding support from the Institute of Health Carlos III (ISCIII) and the European Development Regional Fund (ERDF). One coinvestigator reported consulting in litigation involving two models of inferior vena cava filters.

Dr. Polito reported no disclosures.

In patients with acute pulmonary embolism, using cutoff values other than 110 beats per minute might improve the prognostic value of heart rate at admission, a recent observational study suggests.

Courtesy of Mercy Medical Center

For identifying low-risk patients, a cutoff of 80 bpm increased the sensitivity of the simplified Pulmonary Embolism Severity Index (sPESI) from about 94% to nearly 99% among nonhypotensive patients with acute symptomatic pulmonary embolism (PE), according to results of the large, registry-based study.

Similarly, using a 140-bpm cutoff increased the specificity of the Bova score for identifying intermediate-high–risk patients from about 93% to 98% in the study, which was recently published in the journal CHEST.

“Although standard dichotomization of HR [i.e., HR less than 110 vs. greater than 110 bpm] may be useful for guideline recommendations, our results will allow for more accuracy regarding clinical decision-making,” wrote lead author Ana Jaureguízar, MD, of the University of Alcalá in Madrid, on behalf of the RIETE (Registro Informatizado de la Enfermedad TromboEmbólica) investigators.
 

Intuitive findings inform future research

These observational findings are intuitive and do at least have the potential to inform the design of future randomized clinical trials, according to Albert J. Polito, MD, chief of the division of pulmonary medicine and medical director for the lung center at Mercy Medical Center in Baltimore.

“In medicine, there is a spectrum of risk,” Dr. Polito said in an interview. “While we love our cutoffs, which in this case has traditionally always been that 110 beats per minute for heart rate, it makes sense that there would be some range of risks of bad outcomes.”

Building on the observations of the present study, subsequent prospective randomized studies could potentially aim to determine, for example, when thrombolytic therapy should be considered in nonhypotensive patients with acute PE and higher heart rates.

“It would not be easy to design, but it’s a straightforward question to ask whether patients with the highest heart rates are the ones who potentially might benefit the most from thrombolytic therapy,” Dr. Polito said.
 

Value of alternative HR cutoffs

Heart rate is a simple and easily available vital sign that is clearly linked to prognosis in patients with pulmonary embolism, authors of the RIETE registry study say in their report. Accordingly, a heart rate threshold of 110 bpm has made its way into scoring systems that seek to identify low-risk patients, such as the sPESI, and those focused on identifying higher-risk patients, such as the Bova score.

However, it has not been clear whether alternative HR cutoffs would improve upon the 110-bpm threshold, they added. At the low-risk end, more accurate scoring systems could optimize the selection of patients for home treatment, while at the intermediate-high–risk end, they could better select patients for close monitoring or advanced PE treatments.
 

Better granularity on heart rate risks?

To better define the prognostic value of different heart rate thresholds, investigators analyzed data from RIETE, a large, ongoing, multinational prospective registry including patients with objectively confirmed acute venous thromboembolism.

For 44,331 consecutive nonhypotensive symptomatic PEs, the overall rate of 30-day all-cause mortality was 5.1%, and the 30-day PE-related mortality was 1.9%, the authors report.

Significantly poorer outcomes were seen in patients with higher heart rates as compared to patients in the 80-99 bpm range, they also found. As compared to that reference range, odds ratios for 30-day all-cause death ranged from 1.5 for heart rates of 100-109, up to 2.4 for those with heart rates of 140 bpm or greater.

Likewise, patients with higher heart rates had a 1.7- to 2.4-fold greater risk of 30-day PE-related death as compared to the 80- to 99-bpm reference range, while patients with lower heart rates had lesser risk, the data published in CHEST show.
 

Toward refinement of prognostic scoring

Next, investigators sought to refine the prognostic scoring systems for low-risk PE (sPESI) and intermediate-high–risk PE (Bova).

For sPESI, they found that dropping the cutoff value from 110 to 100 bpm increased the sensitivity of the score from 93.4% to 95.3%. Going down even further to 80 bpm increased sensitivity to 98.8%, according to the report.

By going down from 110 to 80 bpm, the proportion of patients defined as low-risk dropped from 35% to 12%, according to the investigators.

For the Bova score, increasing the cutoff value from 110 to 120 bpm likewise increased specificity from 93.2% to 95%, while going up even further to 140 bpm increased specificity to 98.0%, the report shows.

In sensitivity analyses, the findings were not impacted by excluding younger patients, those who received reperfusion therapies, or those with atrial fibrillation, according to the study findings.
 

Potential implications for clinical practice

Taken together, these findings could serve as a resource to inform discussions regarding PE management that include whether home therapy or use of thrombolytic therapy is appropriate, investigators said in their report.

“For instance, among low-risk sPESI patients, those with borderline tachycardia [i.e., a heart rate between 100-109 bpm] might benefit from initial hospital observation for trending,” they wrote.

Dr. Jaureguízar reported no disclosures. One coinvestigator reported funding support from the Institute of Health Carlos III (ISCIII) and the European Development Regional Fund (ERDF). One coinvestigator reported consulting in litigation involving two models of inferior vena cava filters.

Dr. Polito reported no disclosures.

In patients with acute pulmonary embolism, using cutoff values other than 110 beats per minute might improve the prognostic value of heart rate at admission, a recent observational study suggests.

Courtesy of Mercy Medical Center

For identifying low-risk patients, a cutoff of 80 bpm increased the sensitivity of the simplified Pulmonary Embolism Severity Index (sPESI) from about 94% to nearly 99% among nonhypotensive patients with acute symptomatic pulmonary embolism (PE), according to results of the large, registry-based study.

Similarly, using a 140-bpm cutoff increased the specificity of the Bova score for identifying intermediate-high–risk patients from about 93% to 98% in the study, which was recently published in the journal CHEST.

“Although standard dichotomization of HR [i.e., HR less than 110 vs. greater than 110 bpm] may be useful for guideline recommendations, our results will allow for more accuracy regarding clinical decision-making,” wrote lead author Ana Jaureguízar, MD, of the University of Alcalá in Madrid, on behalf of the RIETE (Registro Informatizado de la Enfermedad TromboEmbólica) investigators.
 

Intuitive findings inform future research

These observational findings are intuitive and do at least have the potential to inform the design of future randomized clinical trials, according to Albert J. Polito, MD, chief of the division of pulmonary medicine and medical director for the lung center at Mercy Medical Center in Baltimore.

“In medicine, there is a spectrum of risk,” Dr. Polito said in an interview. “While we love our cutoffs, which in this case has traditionally always been that 110 beats per minute for heart rate, it makes sense that there would be some range of risks of bad outcomes.”

Building on the observations of the present study, subsequent prospective randomized studies could potentially aim to determine, for example, when thrombolytic therapy should be considered in nonhypotensive patients with acute PE and higher heart rates.

“It would not be easy to design, but it’s a straightforward question to ask whether patients with the highest heart rates are the ones who potentially might benefit the most from thrombolytic therapy,” Dr. Polito said.
 

Value of alternative HR cutoffs

Heart rate is a simple and easily available vital sign that is clearly linked to prognosis in patients with pulmonary embolism, authors of the RIETE registry study say in their report. Accordingly, a heart rate threshold of 110 bpm has made its way into scoring systems that seek to identify low-risk patients, such as the sPESI, and those focused on identifying higher-risk patients, such as the Bova score.

However, it has not been clear whether alternative HR cutoffs would improve upon the 110-bpm threshold, they added. At the low-risk end, more accurate scoring systems could optimize the selection of patients for home treatment, while at the intermediate-high–risk end, they could better select patients for close monitoring or advanced PE treatments.
 

Better granularity on heart rate risks?

To better define the prognostic value of different heart rate thresholds, investigators analyzed data from RIETE, a large, ongoing, multinational prospective registry including patients with objectively confirmed acute venous thromboembolism.

For 44,331 consecutive nonhypotensive symptomatic PEs, the overall rate of 30-day all-cause mortality was 5.1%, and the 30-day PE-related mortality was 1.9%, the authors report.

Significantly poorer outcomes were seen in patients with higher heart rates as compared to patients in the 80-99 bpm range, they also found. As compared to that reference range, odds ratios for 30-day all-cause death ranged from 1.5 for heart rates of 100-109, up to 2.4 for those with heart rates of 140 bpm or greater.

Likewise, patients with higher heart rates had a 1.7- to 2.4-fold greater risk of 30-day PE-related death as compared to the 80- to 99-bpm reference range, while patients with lower heart rates had lesser risk, the data published in CHEST show.
 

Toward refinement of prognostic scoring

Next, investigators sought to refine the prognostic scoring systems for low-risk PE (sPESI) and intermediate-high–risk PE (Bova).

For sPESI, they found that dropping the cutoff value from 110 to 100 bpm increased the sensitivity of the score from 93.4% to 95.3%. Going down even further to 80 bpm increased sensitivity to 98.8%, according to the report.

By going down from 110 to 80 bpm, the proportion of patients defined as low-risk dropped from 35% to 12%, according to the investigators.

For the Bova score, increasing the cutoff value from 110 to 120 bpm likewise increased specificity from 93.2% to 95%, while going up even further to 140 bpm increased specificity to 98.0%, the report shows.

In sensitivity analyses, the findings were not impacted by excluding younger patients, those who received reperfusion therapies, or those with atrial fibrillation, according to the study findings.
 

Potential implications for clinical practice

Taken together, these findings could serve as a resource to inform discussions regarding PE management that include whether home therapy or use of thrombolytic therapy is appropriate, investigators said in their report.

“For instance, among low-risk sPESI patients, those with borderline tachycardia [i.e., a heart rate between 100-109 bpm] might benefit from initial hospital observation for trending,” they wrote.

Dr. Jaureguízar reported no disclosures. One coinvestigator reported funding support from the Institute of Health Carlos III (ISCIII) and the European Development Regional Fund (ERDF). One coinvestigator reported consulting in litigation involving two models of inferior vena cava filters.

Dr. Polito reported no disclosures.

A new study may help doctors assess the long-term risk for major bleeding if anticoagulation for unprovoked venous thromboembolisms (VTE) is continued beyond 3-6 months.

The meta-analysis of data from 27 studies with 17,202 patients was published in the Annals of Internal Medicine. According to two of the paper’s coauthors, Faizan Khan, MSc, and Marc A. Rodger, MD, it “provides best available estimates of long-term bleeding risk with different anticoagulants in patients with unprovoked VTE,” including subgroups at increased risk.

Patients at increased risk for major bleeding include those who are older; those using antiplatelet therapy; and patients with kidney disease, a history of bleeding, or anemia, noted the coauthors, who work for the Ottawa Hospital Research Institute.

The researchers focused on randomized controlled trials (RCTs) and prospective cohort studies that reported major bleeding among patients with a first unprovoked or weakly provoked VTE who received oral anticoagulation for at least 6 months beyond an initial anticoagulant treatment course of at least 3 months.

The investigators analyzed data from 14 RCTs and 13 cohort studies. In all, 9,982 patients received a vitamin K antagonist (VKA), and 7,220 received a direct oral anticoagulant (DOAC).

The incidence of major bleeding per 100 person-years was 1.7 events with VKAs, compared with 1.1 events with DOACs. The researchers estimated that the 5-year cumulative incidence of major bleeding with VKAs was 6.3%. The available data for DOACs were insufficient to estimate the incidence of major bleeding beyond 1 year.

“This information can help clinicians counsel patients and inform shared decision-making about extended therapy,” the researchers said.

Risks of serious bleeding ‘not trivial’

Margaret Fang, MD, with the University of California, San Francisco, agreed that the study can help clinicians and patients weigh the risks of extended anticoagulation for common types of VTE.

The study also “highlights that the risks of serious bleeding are not trivial” and points out gaps in the literature regarding the long-term use of DOACs for extended VTE therapy, Dr. Fang said.

Better ways to predict which patients will develop bleeding on anticoagulants are needed, Dr. Fang added. “It will also be important to establish which of the various therapies for preventing recurrent VTE – full dose versus lowered dose, or even aspirin – has the best balance of safety and efficacy,” she said.

‘Standardized approach’ for identifying high-risk patients lacking

Clinical practice guidelines recommend indefinite anticoagulation for an unprovoked VTE, except when patients are at high risk of bleeding, the authors noted. But clinicians lack a “standardized approach to identify patients at high risk of bleeding,” Mr. Khan and Dr. Rodger said. “Evidence from randomized trials on net long-term benefit of extended therapy is limited, and current guideline recommendations are largely based on expert consensus opinion. Major bleeding events are two to three times more likely to be fatal than recurrent VTE events, so extended therapy is not always associated with a net mortality benefit, particularly in patients at low risk of recurrent VTE or high risk of bleeding.”

The analysis indicates that there is “a clinically meaningful difference in long-term risk for anticoagulant-related major bleeding among patients with a first unprovoked VTE stratified according to presence or absence of the following risk factors: age older than 65 years, creatinine clearance less than 50 mL/min, history of bleeding, concomitant use of antiplatelet therapy, and hemoglobin level less than 100 g/L,” the authors said.

For example, the researchers found that the incidence of major bleeding was higher among those older than 65 years, compared with younger patients (incidence rate ratio, 1.84 with VKAs and 2.92 with DOACs), and among those with creatinine clearance less than 50 mL/min (IRR, 2.83 with VKAs and 3.71 with DOACs).

The case-fatality rate of major bleeding was 8.3% with VKAs and 9.7% with DOACs.

The study received funding from the Canadian Institutes of Health Research. Some of the coauthors are employees of or have financial ties to pharmaceutical companies. Mr. Khan, Dr. Rodger, and Dr. Fang had no relevant disclosures.

jremaly@mdedge.com

A new study may help doctors assess the long-term risk for major bleeding if anticoagulation for unprovoked venous thromboembolisms (VTE) is continued beyond 3-6 months.

The meta-analysis of data from 27 studies with 17,202 patients was published in the Annals of Internal Medicine. According to two of the paper’s coauthors, Faizan Khan, MSc, and Marc A. Rodger, MD, it “provides best available estimates of long-term bleeding risk with different anticoagulants in patients with unprovoked VTE,” including subgroups at increased risk.

Patients at increased risk for major bleeding include those who are older; those using antiplatelet therapy; and patients with kidney disease, a history of bleeding, or anemia, noted the coauthors, who work for the Ottawa Hospital Research Institute.

The researchers focused on randomized controlled trials (RCTs) and prospective cohort studies that reported major bleeding among patients with a first unprovoked or weakly provoked VTE who received oral anticoagulation for at least 6 months beyond an initial anticoagulant treatment course of at least 3 months.

The investigators analyzed data from 14 RCTs and 13 cohort studies. In all, 9,982 patients received a vitamin K antagonist (VKA), and 7,220 received a direct oral anticoagulant (DOAC).

The incidence of major bleeding per 100 person-years was 1.7 events with VKAs, compared with 1.1 events with DOACs. The researchers estimated that the 5-year cumulative incidence of major bleeding with VKAs was 6.3%. The available data for DOACs were insufficient to estimate the incidence of major bleeding beyond 1 year.

“This information can help clinicians counsel patients and inform shared decision-making about extended therapy,” the researchers said.

Risks of serious bleeding ‘not trivial’

Margaret Fang, MD, with the University of California, San Francisco, agreed that the study can help clinicians and patients weigh the risks of extended anticoagulation for common types of VTE.

The study also “highlights that the risks of serious bleeding are not trivial” and points out gaps in the literature regarding the long-term use of DOACs for extended VTE therapy, Dr. Fang said.

Better ways to predict which patients will develop bleeding on anticoagulants are needed, Dr. Fang added. “It will also be important to establish which of the various therapies for preventing recurrent VTE – full dose versus lowered dose, or even aspirin – has the best balance of safety and efficacy,” she said.

‘Standardized approach’ for identifying high-risk patients lacking

Clinical practice guidelines recommend indefinite anticoagulation for an unprovoked VTE, except when patients are at high risk of bleeding, the authors noted. But clinicians lack a “standardized approach to identify patients at high risk of bleeding,” Mr. Khan and Dr. Rodger said. “Evidence from randomized trials on net long-term benefit of extended therapy is limited, and current guideline recommendations are largely based on expert consensus opinion. Major bleeding events are two to three times more likely to be fatal than recurrent VTE events, so extended therapy is not always associated with a net mortality benefit, particularly in patients at low risk of recurrent VTE or high risk of bleeding.”

The analysis indicates that there is “a clinically meaningful difference in long-term risk for anticoagulant-related major bleeding among patients with a first unprovoked VTE stratified according to presence or absence of the following risk factors: age older than 65 years, creatinine clearance less than 50 mL/min, history of bleeding, concomitant use of antiplatelet therapy, and hemoglobin level less than 100 g/L,” the authors said.

For example, the researchers found that the incidence of major bleeding was higher among those older than 65 years, compared with younger patients (incidence rate ratio, 1.84 with VKAs and 2.92 with DOACs), and among those with creatinine clearance less than 50 mL/min (IRR, 2.83 with VKAs and 3.71 with DOACs).

The case-fatality rate of major bleeding was 8.3% with VKAs and 9.7% with DOACs.

The study received funding from the Canadian Institutes of Health Research. Some of the coauthors are employees of or have financial ties to pharmaceutical companies. Mr. Khan, Dr. Rodger, and Dr. Fang had no relevant disclosures.

jremaly@mdedge.com

A new study may help doctors assess the long-term risk for major bleeding if anticoagulation for unprovoked venous thromboembolisms (VTE) is continued beyond 3-6 months.

The meta-analysis of data from 27 studies with 17,202 patients was published in the Annals of Internal Medicine. According to two of the paper’s coauthors, Faizan Khan, MSc, and Marc A. Rodger, MD, it “provides best available estimates of long-term bleeding risk with different anticoagulants in patients with unprovoked VTE,” including subgroups at increased risk.

Patients at increased risk for major bleeding include those who are older; those using antiplatelet therapy; and patients with kidney disease, a history of bleeding, or anemia, noted the coauthors, who work for the Ottawa Hospital Research Institute.

The researchers focused on randomized controlled trials (RCTs) and prospective cohort studies that reported major bleeding among patients with a first unprovoked or weakly provoked VTE who received oral anticoagulation for at least 6 months beyond an initial anticoagulant treatment course of at least 3 months.

The investigators analyzed data from 14 RCTs and 13 cohort studies. In all, 9,982 patients received a vitamin K antagonist (VKA), and 7,220 received a direct oral anticoagulant (DOAC).

The incidence of major bleeding per 100 person-years was 1.7 events with VKAs, compared with 1.1 events with DOACs. The researchers estimated that the 5-year cumulative incidence of major bleeding with VKAs was 6.3%. The available data for DOACs were insufficient to estimate the incidence of major bleeding beyond 1 year.

“This information can help clinicians counsel patients and inform shared decision-making about extended therapy,” the researchers said.

Risks of serious bleeding ‘not trivial’

Margaret Fang, MD, with the University of California, San Francisco, agreed that the study can help clinicians and patients weigh the risks of extended anticoagulation for common types of VTE.

The study also “highlights that the risks of serious bleeding are not trivial” and points out gaps in the literature regarding the long-term use of DOACs for extended VTE therapy, Dr. Fang said.

Better ways to predict which patients will develop bleeding on anticoagulants are needed, Dr. Fang added. “It will also be important to establish which of the various therapies for preventing recurrent VTE – full dose versus lowered dose, or even aspirin – has the best balance of safety and efficacy,” she said.

‘Standardized approach’ for identifying high-risk patients lacking

Clinical practice guidelines recommend indefinite anticoagulation for an unprovoked VTE, except when patients are at high risk of bleeding, the authors noted. But clinicians lack a “standardized approach to identify patients at high risk of bleeding,” Mr. Khan and Dr. Rodger said. “Evidence from randomized trials on net long-term benefit of extended therapy is limited, and current guideline recommendations are largely based on expert consensus opinion. Major bleeding events are two to three times more likely to be fatal than recurrent VTE events, so extended therapy is not always associated with a net mortality benefit, particularly in patients at low risk of recurrent VTE or high risk of bleeding.”

The analysis indicates that there is “a clinically meaningful difference in long-term risk for anticoagulant-related major bleeding among patients with a first unprovoked VTE stratified according to presence or absence of the following risk factors: age older than 65 years, creatinine clearance less than 50 mL/min, history of bleeding, concomitant use of antiplatelet therapy, and hemoglobin level less than 100 g/L,” the authors said.

For example, the researchers found that the incidence of major bleeding was higher among those older than 65 years, compared with younger patients (incidence rate ratio, 1.84 with VKAs and 2.92 with DOACs), and among those with creatinine clearance less than 50 mL/min (IRR, 2.83 with VKAs and 3.71 with DOACs).

The case-fatality rate of major bleeding was 8.3% with VKAs and 9.7% with DOACs.

The study received funding from the Canadian Institutes of Health Research. Some of the coauthors are employees of or have financial ties to pharmaceutical companies. Mr. Khan, Dr. Rodger, and Dr. Fang had no relevant disclosures.

jremaly@mdedge.com

Prophylactic anticoagulation to prevent venous thromboembolism (VTE) was associated with reduced 60-day mortality in patients with COVID-19 who were ill enough to require hospitalization, a new report shows.

In a cohort study of more than 1,300 hospitalized patients with COVID-19 infection across 30 hospitals in Michigan, both prophylactic- and therapeutic-dose anticoagulation were associated with reduced in-hospital mortality; however, at 60 days, only prophylactic-dose anticoagulation remained associated with lower mortality.

And adherence was key; nonadherence, or missing 2 days or more of anticoagulation, was linked to more deaths at 60 days.

The findings, which were published online June 11 in JAMA Network Open, are final proof that a prophylactic anticoagulation strategy for the hospitalized COVID population is, indeed, the right one, Valerie M. Vaughn, MD, director of hospital medicine research at the University of Utah, Salt Lake City, said in an interview.

“We’ve probably always known that patients with COVID need prophylaxis for VTE, but we found that early on, unfortunately, that wasn’t being done,” Dr. Vaughn said.

“Now, we see that prophylactic rates have increased. We always knew to use anticoagulation prophylactically in patients who were hospitalized with infection because of their risk for VTE, so this study just drives home that proper adherence to an anticoagulation protocol improves mortality,” she said.

Dr. Vaughn was on the front lines when COVID-19 came to Michigan, where the research was conducted.

“We probably should have been anticoagulating from the get-go, but you have to remember that in the early days of COVID, the hospitals in Michigan were being overwhelmed. They didn’t have PPE. They were taking care of patients outside of their typical hospital beds or setting up field hospitals,” she said. “It was not quite as bad as New York, but at the University of Michigan, we set up four or five ICUs outside of our normal care.”

They also converted the top floor of their pediatric hospital into an ICU to take care of patients with COVID during the first surge, she added. “We didn’t know much about this disease, but faced with this influx of patients, many of whom were dying with blood clots, we had to do something.”  

Some hospitals began prophylactically anticoagulating their patients, but others hesitated before adopting the strategy. “But now we feel confident that prophylactic anticoagulation, done according to the right protocol, with no interruptions in the treatment, is beneficial,” Dr. Vaughn said.

The best medication choice is enoxaparin (Lovenox), which can be given once a day, as opposed to heparin, which needs to be given via injection three times a day, she said.

“Prophylactic dose anticoagulation is typically given by an injection under the skin, but a lot of times, I’ve had patients tell me they feel like a human pin cushion and have all these bruises from being stuck with needles every day, which I can totally relate to,” she said.

“It is important for us as clinicians to explain that we’re having to poke our patients because it is good for them and will help them fight COVID,” she added. “Also having the once-a-day option is going to be a lot better for adherence, and adherence to the protocol, not missing any days, is key to the better outcome.”

Dr. Vaughn and her team reviewed the charts of 1,351 patients (48% women, 49% Black, median age 64 [range 52-75]) who were hospitalized throughout Michigan during the first several months of the COVID-19 pandemic, from March to June 2020.

Only 18 patients (1.3%) had a confirmed VTE and 219 patients (16.2%) received treatment-dose anticoagulation.

The researchers noted that use of treatment-dose anticoagulation without imaging ranged from 0% to 29% across hospitals and increased significantly over time.

Of the 1,127 patients who received anticoagulation, 392 (34.8%) missed 2 days or more of prophylaxis.

In addition, there were varying rates of missed prophylaxis among the hospitals, from 11% to 61%, but these rates decreased markedly over time.

Missed doses were associated with a higher 60-day mortality (adjusted hazard ratio, 1.31; 95% confidence interval, 1.03-1.67), but not in-hospital mortality (aHR, 0.97; 95% CI, 0.91-1.03).

Compared with no anticoagulation, receiving any dose of anticoagulation was associated with lower in-hospital mortality.

However, only prophylactic-dose anticoagulation remained associated with lower mortality at 60 days. The adjusted hazard ratio for prophylactic-dose anticoagulation was 0.71 (95% CI, 0.51-0.90), compared with 0.92 (95% CI, 0.63-1.35) for treatment-dose anticoagulation.
 

Study boosts confidence

Despite its limitations, the study should make clinicians more confident that the use of prophylactic anticoagulation is warranted for hospitalized patients with COVID-19, write Andrew B. Dicks, MD, and Ido Weinberg, MD, from Massachusetts General Hospital, Boston, in an invited commentary.

“Practically, we still lack the granular data we need to help guide us in patient-by-patient decision-making – such as anticoagulation agent choice, dosage, and duration of therapy – especially as dictated by acuity of patient illness,” Dr. Dicks and Dr. Weinberg note.

“While we still await the data from randomized controlled trials to guide the optimal anticoagulation dose and duration, this study adds significant merit to the previously published recommendations from several different medical organizations regarding the use of prophylactic anticoagulation in hospitalized patients with COVID-19,” Dr. Dicks told this news organization.

The study was supported by Blue Cross and Blue Shield of Michigan and Blue Care Network as part of their Value Partnerships program. Dr. Vaughn has reported receiving speaking fees from Thermo Fisher Scientific. Dr. Dicks and Dr. Weinberg have reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Prophylactic anticoagulation to prevent venous thromboembolism (VTE) was associated with reduced 60-day mortality in patients with COVID-19 who were ill enough to require hospitalization, a new report shows.

In a cohort study of more than 1,300 hospitalized patients with COVID-19 infection across 30 hospitals in Michigan, both prophylactic- and therapeutic-dose anticoagulation were associated with reduced in-hospital mortality; however, at 60 days, only prophylactic-dose anticoagulation remained associated with lower mortality.

And adherence was key; nonadherence, or missing 2 days or more of anticoagulation, was linked to more deaths at 60 days.

The findings, which were published online June 11 in JAMA Network Open, are final proof that a prophylactic anticoagulation strategy for the hospitalized COVID population is, indeed, the right one, Valerie M. Vaughn, MD, director of hospital medicine research at the University of Utah, Salt Lake City, said in an interview.

“We’ve probably always known that patients with COVID need prophylaxis for VTE, but we found that early on, unfortunately, that wasn’t being done,” Dr. Vaughn said.

“Now, we see that prophylactic rates have increased. We always knew to use anticoagulation prophylactically in patients who were hospitalized with infection because of their risk for VTE, so this study just drives home that proper adherence to an anticoagulation protocol improves mortality,” she said.

Dr. Vaughn was on the front lines when COVID-19 came to Michigan, where the research was conducted.

“We probably should have been anticoagulating from the get-go, but you have to remember that in the early days of COVID, the hospitals in Michigan were being overwhelmed. They didn’t have PPE. They were taking care of patients outside of their typical hospital beds or setting up field hospitals,” she said. “It was not quite as bad as New York, but at the University of Michigan, we set up four or five ICUs outside of our normal care.”

They also converted the top floor of their pediatric hospital into an ICU to take care of patients with COVID during the first surge, she added. “We didn’t know much about this disease, but faced with this influx of patients, many of whom were dying with blood clots, we had to do something.”  

Some hospitals began prophylactically anticoagulating their patients, but others hesitated before adopting the strategy. “But now we feel confident that prophylactic anticoagulation, done according to the right protocol, with no interruptions in the treatment, is beneficial,” Dr. Vaughn said.

The best medication choice is enoxaparin (Lovenox), which can be given once a day, as opposed to heparin, which needs to be given via injection three times a day, she said.

“Prophylactic dose anticoagulation is typically given by an injection under the skin, but a lot of times, I’ve had patients tell me they feel like a human pin cushion and have all these bruises from being stuck with needles every day, which I can totally relate to,” she said.

“It is important for us as clinicians to explain that we’re having to poke our patients because it is good for them and will help them fight COVID,” she added. “Also having the once-a-day option is going to be a lot better for adherence, and adherence to the protocol, not missing any days, is key to the better outcome.”

Dr. Vaughn and her team reviewed the charts of 1,351 patients (48% women, 49% Black, median age 64 [range 52-75]) who were hospitalized throughout Michigan during the first several months of the COVID-19 pandemic, from March to June 2020.

Only 18 patients (1.3%) had a confirmed VTE and 219 patients (16.2%) received treatment-dose anticoagulation.

The researchers noted that use of treatment-dose anticoagulation without imaging ranged from 0% to 29% across hospitals and increased significantly over time.

Of the 1,127 patients who received anticoagulation, 392 (34.8%) missed 2 days or more of prophylaxis.

In addition, there were varying rates of missed prophylaxis among the hospitals, from 11% to 61%, but these rates decreased markedly over time.

Missed doses were associated with a higher 60-day mortality (adjusted hazard ratio, 1.31; 95% confidence interval, 1.03-1.67), but not in-hospital mortality (aHR, 0.97; 95% CI, 0.91-1.03).

Compared with no anticoagulation, receiving any dose of anticoagulation was associated with lower in-hospital mortality.

However, only prophylactic-dose anticoagulation remained associated with lower mortality at 60 days. The adjusted hazard ratio for prophylactic-dose anticoagulation was 0.71 (95% CI, 0.51-0.90), compared with 0.92 (95% CI, 0.63-1.35) for treatment-dose anticoagulation.
 

Study boosts confidence

Despite its limitations, the study should make clinicians more confident that the use of prophylactic anticoagulation is warranted for hospitalized patients with COVID-19, write Andrew B. Dicks, MD, and Ido Weinberg, MD, from Massachusetts General Hospital, Boston, in an invited commentary.

“Practically, we still lack the granular data we need to help guide us in patient-by-patient decision-making – such as anticoagulation agent choice, dosage, and duration of therapy – especially as dictated by acuity of patient illness,” Dr. Dicks and Dr. Weinberg note.

“While we still await the data from randomized controlled trials to guide the optimal anticoagulation dose and duration, this study adds significant merit to the previously published recommendations from several different medical organizations regarding the use of prophylactic anticoagulation in hospitalized patients with COVID-19,” Dr. Dicks told this news organization.

The study was supported by Blue Cross and Blue Shield of Michigan and Blue Care Network as part of their Value Partnerships program. Dr. Vaughn has reported receiving speaking fees from Thermo Fisher Scientific. Dr. Dicks and Dr. Weinberg have reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Prophylactic anticoagulation to prevent venous thromboembolism (VTE) was associated with reduced 60-day mortality in patients with COVID-19 who were ill enough to require hospitalization, a new report shows.

In a cohort study of more than 1,300 hospitalized patients with COVID-19 infection across 30 hospitals in Michigan, both prophylactic- and therapeutic-dose anticoagulation were associated with reduced in-hospital mortality; however, at 60 days, only prophylactic-dose anticoagulation remained associated with lower mortality.

And adherence was key; nonadherence, or missing 2 days or more of anticoagulation, was linked to more deaths at 60 days.

The findings, which were published online June 11 in JAMA Network Open, are final proof that a prophylactic anticoagulation strategy for the hospitalized COVID population is, indeed, the right one, Valerie M. Vaughn, MD, director of hospital medicine research at the University of Utah, Salt Lake City, said in an interview.

“We’ve probably always known that patients with COVID need prophylaxis for VTE, but we found that early on, unfortunately, that wasn’t being done,” Dr. Vaughn said.

“Now, we see that prophylactic rates have increased. We always knew to use anticoagulation prophylactically in patients who were hospitalized with infection because of their risk for VTE, so this study just drives home that proper adherence to an anticoagulation protocol improves mortality,” she said.

Dr. Vaughn was on the front lines when COVID-19 came to Michigan, where the research was conducted.

“We probably should have been anticoagulating from the get-go, but you have to remember that in the early days of COVID, the hospitals in Michigan were being overwhelmed. They didn’t have PPE. They were taking care of patients outside of their typical hospital beds or setting up field hospitals,” she said. “It was not quite as bad as New York, but at the University of Michigan, we set up four or five ICUs outside of our normal care.”

They also converted the top floor of their pediatric hospital into an ICU to take care of patients with COVID during the first surge, she added. “We didn’t know much about this disease, but faced with this influx of patients, many of whom were dying with blood clots, we had to do something.”  

Some hospitals began prophylactically anticoagulating their patients, but others hesitated before adopting the strategy. “But now we feel confident that prophylactic anticoagulation, done according to the right protocol, with no interruptions in the treatment, is beneficial,” Dr. Vaughn said.

The best medication choice is enoxaparin (Lovenox), which can be given once a day, as opposed to heparin, which needs to be given via injection three times a day, she said.

“Prophylactic dose anticoagulation is typically given by an injection under the skin, but a lot of times, I’ve had patients tell me they feel like a human pin cushion and have all these bruises from being stuck with needles every day, which I can totally relate to,” she said.

“It is important for us as clinicians to explain that we’re having to poke our patients because it is good for them and will help them fight COVID,” she added. “Also having the once-a-day option is going to be a lot better for adherence, and adherence to the protocol, not missing any days, is key to the better outcome.”

Dr. Vaughn and her team reviewed the charts of 1,351 patients (48% women, 49% Black, median age 64 [range 52-75]) who were hospitalized throughout Michigan during the first several months of the COVID-19 pandemic, from March to June 2020.

Only 18 patients (1.3%) had a confirmed VTE and 219 patients (16.2%) received treatment-dose anticoagulation.

The researchers noted that use of treatment-dose anticoagulation without imaging ranged from 0% to 29% across hospitals and increased significantly over time.

Of the 1,127 patients who received anticoagulation, 392 (34.8%) missed 2 days or more of prophylaxis.

In addition, there were varying rates of missed prophylaxis among the hospitals, from 11% to 61%, but these rates decreased markedly over time.

Missed doses were associated with a higher 60-day mortality (adjusted hazard ratio, 1.31; 95% confidence interval, 1.03-1.67), but not in-hospital mortality (aHR, 0.97; 95% CI, 0.91-1.03).

Compared with no anticoagulation, receiving any dose of anticoagulation was associated with lower in-hospital mortality.

However, only prophylactic-dose anticoagulation remained associated with lower mortality at 60 days. The adjusted hazard ratio for prophylactic-dose anticoagulation was 0.71 (95% CI, 0.51-0.90), compared with 0.92 (95% CI, 0.63-1.35) for treatment-dose anticoagulation.
 

Study boosts confidence

Despite its limitations, the study should make clinicians more confident that the use of prophylactic anticoagulation is warranted for hospitalized patients with COVID-19, write Andrew B. Dicks, MD, and Ido Weinberg, MD, from Massachusetts General Hospital, Boston, in an invited commentary.

“Practically, we still lack the granular data we need to help guide us in patient-by-patient decision-making – such as anticoagulation agent choice, dosage, and duration of therapy – especially as dictated by acuity of patient illness,” Dr. Dicks and Dr. Weinberg note.

“While we still await the data from randomized controlled trials to guide the optimal anticoagulation dose and duration, this study adds significant merit to the previously published recommendations from several different medical organizations regarding the use of prophylactic anticoagulation in hospitalized patients with COVID-19,” Dr. Dicks told this news organization.

The study was supported by Blue Cross and Blue Shield of Michigan and Blue Care Network as part of their Value Partnerships program. Dr. Vaughn has reported receiving speaking fees from Thermo Fisher Scientific. Dr. Dicks and Dr. Weinberg have reported no relevant financial relationships.

A version of this article first appeared on Medscape.com.

The incidence of venous thromboembolism (VTE) in nonhospitalized patients with COVID-19 was not significantly different from patients without the infectious disease, according to a new study published in JAMA Internal Medicine.

Design Cells/Getty Images

National Institutes of Health guidelines recommend blood thinners to prevent blood clots in patients hospitalized with COVID-19. However, the new study provides more insight on the best treatment approach for COVID-19 outpatients.

“[COVID-19’s] rapid global progression and impact has caused us to make and modify treatment decisions at a pace that we never have in modern medicine,” study author Nareg Roubinian, MD, an investigator at Kaiser Permanente, Oakland, Calif., said in an interview.

“As with other potential therapies for COVID-19, blood thinners need to be prospectively studied in a clinical trial to determine if they improve patient outcomes,” Dr. Roubinian added.

The increased risk of blood clots in patients hospitalized with COVID-19 has been a major issue throughout the pandemic. In fact, one study published in November 2020 found that more than half of patients hospitalized with the illness have prothrombotic antiphospholipid (aPL) autoantibodies in their blood, which could contribute to venous and arterial thromboembolism.

Although it was clear many hospitalized patients diagnosed with COVID-19 were developing more clots, researchers of the current study were not sure if this trend would also be seen in outpatients.

“Most people with COVID-19 do not need to be hospitalized, and we needed to know how often patients outside the hospital were having blood clots,” said Dr. Roubinian.

For the study, Dr. Roubinian and colleagues examined data on 220,588 patients who were members of Kaiser Permanente Northern California health plan and were tested for COVID-19 between Feb. 25 and Aug. 31, 2020. They then reported on the 30-day incidence of outpatient and hospital-associated blood clots following the COVID-19 diagnosis. Patients who were asymptomatic at the time of testing or had received anticoagulants within the last year were excluded.

“We knew from other studies that patients with COVID-19 often get sicker in the first few weeks after infection. What we didn’t know was whether COVID-19 patients were developing blood clots but not pneumonia or were developing blood clots at the same time as they developed pneumonia,” said Dr. Roubinian, an intensive care doctor with the Permanente Medical Group in Oakland, Calif. “Following the patients for 30 days allowed us to focus on the time period from infection to when blood clots were most likely to develop.”

Researchers found that of the cohort who took the COVID-19 test, 11.8% had a positive result. Within 30 days of the COVID-19 test, 0.8% of patients with a positive result were diagnosed with VTE compared to 0.5% of those who received a negative test result. They also found that viral testing took place in an outpatient setting for 59.1% of the patients with a positive viral test who later developed VTE. Of those patients, 76.1% had to be hospitalized.

Dr. Roubinian said he was surprised to see that the blood clotting in outpatients with COVID-19 was similar in frequency to what he saw in patients without the infection.

“Our findings suggest that blood clots do occur in COVID-19 patients but not on a scale where we need to put all or many COVID outpatients on blood thinners,” he said. “As with other potential therapies for COVID-19, blood thinners need to be prospectively studied in a clinical trial to determine if they improve patient outcomes.”

In December 2020, three trials investigating the risk and benefits of increased levels of anticoagulation in hospitalized COVID-19 patients were paused because of safety issues. The trials would have enrolled critically ill COVID-19 patients for whom therapeutic doses of anticoagulation drugs showed no benefit.

Anticoagulants are associated with bleeding risks, including prolonged nosebleeds and vomiting or coughing up blood.

Instead of prescribing the routine use of thromboprophylactic drugs to COVID-19 outpatients, Dr. Roubinian believes it would be helpful to learn how to determine whether a patient at risk of becoming sick or being hospitalized would benefit from being treated with such drugs.

Dr. Roubinian reported receiving grants from the National Institutes of Health and the National Heart, Lung, and Blood Institute during the conduct of the study.
 

The incidence of venous thromboembolism (VTE) in nonhospitalized patients with COVID-19 was not significantly different from patients without the infectious disease, according to a new study published in JAMA Internal Medicine.

Design Cells/Getty Images

National Institutes of Health guidelines recommend blood thinners to prevent blood clots in patients hospitalized with COVID-19. However, the new study provides more insight on the best treatment approach for COVID-19 outpatients.

“[COVID-19’s] rapid global progression and impact has caused us to make and modify treatment decisions at a pace that we never have in modern medicine,” study author Nareg Roubinian, MD, an investigator at Kaiser Permanente, Oakland, Calif., said in an interview.

“As with other potential therapies for COVID-19, blood thinners need to be prospectively studied in a clinical trial to determine if they improve patient outcomes,” Dr. Roubinian added.

The increased risk of blood clots in patients hospitalized with COVID-19 has been a major issue throughout the pandemic. In fact, one study published in November 2020 found that more than half of patients hospitalized with the illness have prothrombotic antiphospholipid (aPL) autoantibodies in their blood, which could contribute to venous and arterial thromboembolism.

Although it was clear many hospitalized patients diagnosed with COVID-19 were developing more clots, researchers of the current study were not sure if this trend would also be seen in outpatients.

“Most people with COVID-19 do not need to be hospitalized, and we needed to know how often patients outside the hospital were having blood clots,” said Dr. Roubinian.

For the study, Dr. Roubinian and colleagues examined data on 220,588 patients who were members of Kaiser Permanente Northern California health plan and were tested for COVID-19 between Feb. 25 and Aug. 31, 2020. They then reported on the 30-day incidence of outpatient and hospital-associated blood clots following the COVID-19 diagnosis. Patients who were asymptomatic at the time of testing or had received anticoagulants within the last year were excluded.

“We knew from other studies that patients with COVID-19 often get sicker in the first few weeks after infection. What we didn’t know was whether COVID-19 patients were developing blood clots but not pneumonia or were developing blood clots at the same time as they developed pneumonia,” said Dr. Roubinian, an intensive care doctor with the Permanente Medical Group in Oakland, Calif. “Following the patients for 30 days allowed us to focus on the time period from infection to when blood clots were most likely to develop.”

Researchers found that of the cohort who took the COVID-19 test, 11.8% had a positive result. Within 30 days of the COVID-19 test, 0.8% of patients with a positive result were diagnosed with VTE compared to 0.5% of those who received a negative test result. They also found that viral testing took place in an outpatient setting for 59.1% of the patients with a positive viral test who later developed VTE. Of those patients, 76.1% had to be hospitalized.

Dr. Roubinian said he was surprised to see that the blood clotting in outpatients with COVID-19 was similar in frequency to what he saw in patients without the infection.

“Our findings suggest that blood clots do occur in COVID-19 patients but not on a scale where we need to put all or many COVID outpatients on blood thinners,” he said. “As with other potential therapies for COVID-19, blood thinners need to be prospectively studied in a clinical trial to determine if they improve patient outcomes.”

In December 2020, three trials investigating the risk and benefits of increased levels of anticoagulation in hospitalized COVID-19 patients were paused because of safety issues. The trials would have enrolled critically ill COVID-19 patients for whom therapeutic doses of anticoagulation drugs showed no benefit.

Anticoagulants are associated with bleeding risks, including prolonged nosebleeds and vomiting or coughing up blood.

Instead of prescribing the routine use of thromboprophylactic drugs to COVID-19 outpatients, Dr. Roubinian believes it would be helpful to learn how to determine whether a patient at risk of becoming sick or being hospitalized would benefit from being treated with such drugs.

Dr. Roubinian reported receiving grants from the National Institutes of Health and the National Heart, Lung, and Blood Institute during the conduct of the study.
 

The incidence of venous thromboembolism (VTE) in nonhospitalized patients with COVID-19 was not significantly different from patients without the infectious disease, according to a new study published in JAMA Internal Medicine.

Design Cells/Getty Images

National Institutes of Health guidelines recommend blood thinners to prevent blood clots in patients hospitalized with COVID-19. However, the new study provides more insight on the best treatment approach for COVID-19 outpatients.

“[COVID-19’s] rapid global progression and impact has caused us to make and modify treatment decisions at a pace that we never have in modern medicine,” study author Nareg Roubinian, MD, an investigator at Kaiser Permanente, Oakland, Calif., said in an interview.

“As with other potential therapies for COVID-19, blood thinners need to be prospectively studied in a clinical trial to determine if they improve patient outcomes,” Dr. Roubinian added.

The increased risk of blood clots in patients hospitalized with COVID-19 has been a major issue throughout the pandemic. In fact, one study published in November 2020 found that more than half of patients hospitalized with the illness have prothrombotic antiphospholipid (aPL) autoantibodies in their blood, which could contribute to venous and arterial thromboembolism.

Although it was clear many hospitalized patients diagnosed with COVID-19 were developing more clots, researchers of the current study were not sure if this trend would also be seen in outpatients.

“Most people with COVID-19 do not need to be hospitalized, and we needed to know how often patients outside the hospital were having blood clots,” said Dr. Roubinian.

For the study, Dr. Roubinian and colleagues examined data on 220,588 patients who were members of Kaiser Permanente Northern California health plan and were tested for COVID-19 between Feb. 25 and Aug. 31, 2020. They then reported on the 30-day incidence of outpatient and hospital-associated blood clots following the COVID-19 diagnosis. Patients who were asymptomatic at the time of testing or had received anticoagulants within the last year were excluded.

“We knew from other studies that patients with COVID-19 often get sicker in the first few weeks after infection. What we didn’t know was whether COVID-19 patients were developing blood clots but not pneumonia or were developing blood clots at the same time as they developed pneumonia,” said Dr. Roubinian, an intensive care doctor with the Permanente Medical Group in Oakland, Calif. “Following the patients for 30 days allowed us to focus on the time period from infection to when blood clots were most likely to develop.”

Researchers found that of the cohort who took the COVID-19 test, 11.8% had a positive result. Within 30 days of the COVID-19 test, 0.8% of patients with a positive result were diagnosed with VTE compared to 0.5% of those who received a negative test result. They also found that viral testing took place in an outpatient setting for 59.1% of the patients with a positive viral test who later developed VTE. Of those patients, 76.1% had to be hospitalized.

Dr. Roubinian said he was surprised to see that the blood clotting in outpatients with COVID-19 was similar in frequency to what he saw in patients without the infection.

“Our findings suggest that blood clots do occur in COVID-19 patients but not on a scale where we need to put all or many COVID outpatients on blood thinners,” he said. “As with other potential therapies for COVID-19, blood thinners need to be prospectively studied in a clinical trial to determine if they improve patient outcomes.”

In December 2020, three trials investigating the risk and benefits of increased levels of anticoagulation in hospitalized COVID-19 patients were paused because of safety issues. The trials would have enrolled critically ill COVID-19 patients for whom therapeutic doses of anticoagulation drugs showed no benefit.

Anticoagulants are associated with bleeding risks, including prolonged nosebleeds and vomiting or coughing up blood.

Instead of prescribing the routine use of thromboprophylactic drugs to COVID-19 outpatients, Dr. Roubinian believes it would be helpful to learn how to determine whether a patient at risk of becoming sick or being hospitalized would benefit from being treated with such drugs.

Dr. Roubinian reported receiving grants from the National Institutes of Health and the National Heart, Lung, and Blood Institute during the conduct of the study.