Cleveland Clinic Journal of Medicine

Perioperative medicine is an evolving field with a rapidly growing body of literature. Because physicians and patients are often concerned about cardiac risk, we focus this review on perioperative cardiology.

The information we present here is derived from presentations at the Perioperative Medicine Summit and the annual meetings of the Society of Hospital Medicine and Society of General Internal Medicine in 2016. We surveyed perioperative literature from January 2015 through March 2016 and chose the final articles by consensus, based on relevance to clinicians who provide preoperative evaluations and postoperative care to surgical patients.

We have divided this review into four sections:

• Preoperative cardiac risk assessment
• Medical therapy to reduce postoperative cardiac complications (beta-blockers, statins, and angiotensin II receptor blockers [ARBs])
• Perioperative management of patients with a coronary stent on antiplatelet therapy
• Perioperative bridging anticoagulation.

PREOPERATIVE ASSESSMENT OF CARDIAC RISK

Functionally independent patients do better

Visnjevac O, Davari-Farid S, Lee J, et al. The effect of adding functional classification to ASA status for predicting 30-day mortality. Anesth Analg 2015; 121:110–116.

Functional capacity is an independent predictor of perioperative death and is included in the algorithm of the current joint American College of Cardiology/American Heart Association (ACC/AHA) guidelines,¹ but it is not in the Revised Cardiac Risk Index² or the American Society of Anesthesiologists (ASA) classification.³

The study. Visnjevac et al⁴ performed a retrospective, observational cohort study of 12,324 patients who underwent noncardiac surgery, stratifying rates of all-cause mortality and 30-day postoperative complications based on ASA class and functional capacity.

The ASA physical status classification is defined as:

• 1—Normal healthy patient
• 2—Patient with mild systemic disease
• 3—Patient with severe systemic disease
• 4—Patient with severe systemic disease that is a constant threat to life
• 5—Moribund patient not expected to survive without surgery.

Functional capacity was defined as the ability to perform all activities of daily living. It was prospectively assessed during the patient interview by pre-anesthesia personnel and entered into the database of the Veterans Affairs Surgical Quality Improvement Program.

Results. Within each ASA class, the mortality rate was significantly lower for functionally independent patients than for partially or fully dependent patients:

• In class 2—odds ratio (OR) 0.14 for functionally independent patients
• In class 3—OR 0.29 for functionally independent patients
• In class 4—OR 0.5 for functionally independent patients.

The mortality rate was higher for dependent patients than for independent patients who were one ASA class higher, despite the higher class having greater rates of comorbidity.

Adding functional capacity to the ASA classification improved the area under the receiver operating curve from 0.811 to 0.848 (a perfect test would have a value of 1.0), suggesting that physicians should incorporate functional capacity into their preoperative evaluation, perhaps by increasing a patient’s ASA class to the next higher class if he or she is functionally dependent.

Angina portends poor outcomes

Pandey A, Sood A, Sammon JD, et al. Effect of preoperative angina pectoris on cardiac outcomes in patients with previous myocardial infarction undergoing major noncardiac surgery (data from ACS-NSQIP). Am J Cardiol 2015; 115:1080–1084.

Coronary artery disease is a risk factor for adverse perioperative outcomes, but the risk varies depending on whether the patient has had a myocardial infarction (and how long ago) and whether he or she has anginal symptoms (and how severe they are).

The study. Pandey et al⁵ used data from the American College of Surgeons National Surgical Quality Improvement Program to evaluate the impact of stable angina in 1,568 patients who underwent noncardiac surgery after a myocardial infarction.

Results. Postoperative myocardial infarction or cardiac arrest occurred in 5.5% of patients. The incidence was significantly greater in those who had anginal symptoms before surgery than in those without symptoms (8.4% vs 5%, P = .035); reintervention rates and length of stay were also higher in this group. In multivariate analysis, preoperative angina remained a significant predictor of postoperative myocardial infarction (OR 2.49, 95% confidence interval [CI] 1.20–5.81) and re­intervention (OR 2.4, 95% CI 1.44–3.82.

The authors cautioned against relying on predictive tools such as the Revised Cardiac Risk Index that do not consider stable angina and previous myocardial infarction as separate independent risk factors.

Implications for clinical practice. While functional capacity is an integral part of the ACC/AHA guideline algorithm,¹ the findings of these two studies suggest that other current tools to calculate perioperative risk (ASA class and Revised Cardiac Risk Index) could be improved by including functional capacity and stable angina.

PERIOPERATIVE MEDICAL THERAPY

Beta-blockers help only those at high risk and may harm others

Friedell ML, Van Way CW 3rd, Freyberg RW, Almenoff PL. ß-blockade and operative mortality in noncardiac surgery: harmful or helpful? JAMA Surg 2015; 150:658–663.

Beta-blockers have been used perioperatively for nearly 2 decades to try to reduce rates of postoperative major adverse cardiovascular events. However, in view of recent trials, fewer patients are likely to benefit from this intervention than has been thought.

The study. Friedell et al⁶ retrospectively analyzed data from 343,645 patients in Veterans Affairs hospitals to determine the effect of beta-blockers on major adverse cardiac event rates after major noncardiac surgery. Beta-blockers were considered to have been used perioperatively if given any time between 8 hours before and 24 hours after surgery. The outcome studied was the mortality rate at 30 days.

The authors derived a novel risk score and used multivariate analysis to attempt to adjust for confounding factors. The risk score was based on four risk factors identified a priori:

• Serum creatinine level > 2.0 mg/dL
• Coronary artery disease
• Diabetes
• Surgery in a major body cavity (abdomen or chest).

Results. In this cohort, 43.2% of patients had received a beta-blocker. The unadjusted mortality rates by risk category for patients receiving or not receiving a beta-blocker were:

• No risk factors: 1.0% with a beta-blocker vs 0.6% without
• One or two risk factors: 1.7% vs 1.5%
• Three or four risk factors: 2.3% vs 4.5%.

After adjustment for confounding factors, the 30-day mortality rate was higher in low-risk patients and lower in high-risk patients who received beta-blockers. Odds ratios for death in beta-blocker users (entire cohort) by risk category were:

• No risk factors: 1.19
• One or two risk factors 0.97
• Three or four risk factors 0.76.

In the 3.8% of the total cohort who underwent cardiac surgery, beta-blockers had no significant effect—beneficial or harmful—in any risk group.

Jørgensen ME, Hlatky MA, Køber L, et al. ß-blocker-associated risks in patients with uncomplicated hypertension undergoing noncardiac surgery. JAMA Intern Med 2015; 175:1923–1931.

The study. Jørgensen et al⁷ investigated the association between chronic beta-blocker use for the treatment of hypertension and 30-day rates of mortality and major adverse cardiac events. Eligible patients (N = 55,320) were at least 20 years old and were undergoing any type of noncardiac surgery. The authors established that hypertension was present through use of an algorithm based on the International Classification of Diseases (10th edition). Patients with existing cardiovascular disease and renal disease were excluded. The authors used multivariate analysis to adjust for confounding factors.

Results. Twenty-six percent of the patients were on chronic beta-blocker therapy for hypertension. The mortality rate at 30 days was 1.93% in patients treated with a beta-blocker alone or in combination with other antihypertensive drugs; the rate was 1.32% for patients receiving any combination of renin-angiotensin system inhibitor, calcium antagonist, or thiazide, but no beta-blocker. Similarly, the 30-day major adverse cardiac event rates were 1.32% with beta-blockers and 0.84% without beta-blockers.

In subgroup analysis, each medication combination that included a beta-blocker was associated with higher rates of death and major adverse cardiac events than the same combination without a beta-blocker. Odds ratios for major adverse cardiac events with beta-blocker combinations ranged from 1.22 to 2.16 compared with regimens with no beta-blocker.

Implications for clinical practice. These two studies added to a growing chorus of concerns about the value and safety of beta-blockers in surgical patients. Friedell et al⁶ made an observation that was remarkably similar to one reported by Lindenauer et al⁸ in 2005: when patients were stratified by baseline risk of death, only those with the highest baseline risk benefited from beta-blocker therapy. Those in the lowest risk group actually were harmed by beta-blocker use, ie, the mortality rate was higher.

More interesting is the novel observation by Jørgensen et al⁷ that even in patients with no known cardiovascular disease who are on chronic beta-blocker therapy—presumably on stable doses and not solely for perioperative risk reduction—rates of mortality and major adverse cardiac events were higher than for patients not on chronic beta-blocker therapy.

The current studies support a cautious, selective approach to the perioperative use of beta-blockers—they should be used only in high-risk patients undergoing high-risk surgery, as has been proposed by the ACC/AHA.¹

Statins protect

Antoniou GA, Hajibandeh S, Hajibandeh S, Vallabhaneni SR, Brennan JA, Torella F. Meta-analysis of the effects of statins on perioperative outcomes in vascular and endovascular surgery. J Vasc Surg 2015; 61:519–532.

The study⁹ was a comprehensive meta-analysis of randomized controlled trials and observational studies of the effects of HMG-CoA reductase inhibitors (statins) on perioperative outcomes in patients undergoing vascular surgery (but not for intracranial or coronary artery disease). Twenty-four studies were included, 4 randomized controlled trials and 20 observational studies (including 16 cohort and 4 case-controlled studies), with a total of 22,536 patients, 8,052 receiving statins and 15,484 not receiving statins.

Results. Although there was no significant difference in cardiovascular mortality rates, patients receiving statins had significantly lower rates of all-cause mortality, myocardial infarction, stroke, and a composite of myocardial infarction, stroke, and death at 30 days postoperatively than patients not receiving statins. Additionally, there was no difference in the incidence of kidney injury between groups. The possibility of publication bias was thought to be low for all of these outcomes.

Berwanger O, Le Manach Y, Suzumura EA, et al. Association between pre-operative statin use and major cardiovascular complications among patients undergoing non-cardiac surgery: the VISION study. Eur Heart J 2016; 37:177–185.

The study. The Vascular Events in Non-cardiac Surgery Patients Cohort Evaluation (VISION) study^10,11 was an international prospective cohort study of more than 40,000 patients age 45 and older undergoing major noncardiac surgery with either general or regional anesthesia. Postoperative troponin measurements were obtained in all patients 6 to 12 hours after surgery and for the first 3 postoperative days. The authors evaluated the effect of preoperative statin use on cardiovascular outcomes at 30 days after surgery using a multivariate logistic model and propensity score analysis to correct for confounding factors. Statin use was defined as exposure within 7 days before surgery or 3 days after.

Results. In the 15,478 patients included in the analysis, statin use conferred a significant reduction in the primary outcome (composite of all-cause mortality, myocardial injury after noncardiac surgery, or stroke); the absolute risk reduction was 2.0%. Statin users also had a significantly lower risk of all-cause mortality, cardiovascular mortality, and myocardial injury after noncardiac surgery, but not of postoperative myocardial infarction or stroke. This analysis did not address the type of statin, dosing, or safety markers such as liver and muscle function.

Implications for clinical practice. With largely observational data and a few small randomized trials, these meta-analyses provide important information with respect to perioperative cardiovascular protection by statins. Starting a statin before surgery and continuing it perioperatively seems appropriate in patients at high risk (as recommended by the ACC/AHA guidelines¹). Based on other data, the benefit may be evident in as little as 5 days, as this is when statins appear to reach their plateau with regard to their vascular pleiotropic effects.¹² The incidence of adverse effects of statins, including muscle and liver injury, appears to be low in the perioperative setting.¹³

Given the inconsistent data regarding perioperative beta-blocker therapy, statins may very well be the most important perioperative medication with respect to cardiovascular risk reduction. However, a large randomized trial would help to confirm this belief.

Restart angiotensin II receptor blockers soon after surgery

Lee SM, Takemoto S, Wallace AW. Association between withholding angiotensin receptor blockers in the early postoperative period and 30-day mortality: a cohort study of the Veterans Affairs Healthcare System. Anesthesiology 2015; 123:288–306.

A concern about perioperative use of ARBs is that they impair the renin-angiotensin-aldosterone system, which maintains blood pressure under general anesthesia. ARB-induced intraoperative hypotension is particularly difficult to control, as it is often refractory to treatment with conventional adrenergic vasopressors.

The study. Lee et al¹⁴ conducted a retrospective cohort trial to evaluate the effects of continuing to withhold ARBs postoperatively. Of the 30,173 patients admitted for surgery in the Veterans Affairs system from 1999 through 2011 who were taking an ARB before surgery and who met the inclusion criteria, 10,205 (33.8%) were not restarted on their medication by postoperative day 2.

Results. The mortality rate at 30 days was higher in those whose ARBs were withheld than in those in whom it was resumed, with a multivariable-adjusted hazard ratio of 1.74 (95% CI 1.47–2.06; P < .001). The risk of withholding ARBs was more pronounced in younger patients (hazard ratio 2.52; 95% CI 1.69–3.76 in those under age 60) than in older patients (hazard ratio 1.42, 95% CI 1.09–1.85 in those over age 75).

Implications for clinical practice. While not addressing whether to continue or withhold ARBs preoperatively, this retrospective study presented evidence that delay in resuming chronic ARB therapy after surgery was common and appeared to be associated with a higher 30-day mortality rate. The ACC/AHA guidelines¹ state:

• Continuing angiotensin-converting enzyme (ACE) inhibitors or ARBs perioperatively is reasonable (class IIa recommendation, level of evidence B) (Table 1).
• If an ACE inhibitor or ARB is withheld before surgery, it is reasonable to restart it postoperatively as soon as clinically feasible (class IIa recommendation, level of evidence C).

Close attention to medication reconciliation in the postoperative period is necessary to facilitate early resumption of ARBs.

CORONARY STENTS AND ANTIPLATELET THERAPY IN NONCARDIAC SURGERY PATIENTS

Considerations in the management of noncardiac surgery patients with stents include risks of stent thrombosis, bleeding, and potentially delaying procedures to continue uninterrupted dual antiplatelet therapy. Evidence is evolving regarding the risks of perioperative complications in patients with bare-metal stents and drug-eluting stents, as well as the optimal timing before noncardiac surgery.

Bare-metal vs drug-eluting stents

Bangalore S, Silbaugh TS, Normand SL, Lovett AF, Welt FG, Resnic FS. Drug-eluting stents versus bare metal stents prior to noncardiac surgery. Catheter Cardiovasc Interv 2015; 85:533–541.

The study. Bangalore et al¹⁵ compared the safety of drug-eluting vs bare-metal stents in noncardiac surgery patients and investigated adverse events stratified by time since stent placement. This was a retrospective observational study of 8,415 patients in the Massachusetts claims database who underwent noncardiac surgery 1 year or less after percutaneous coronary intervention.

Results. There was no significant difference in the incidence of the primary outcome (composite of death, myocardial infarction, and bleeding) between the two groups.

With drug-eluting stents, patients had lower 30-day postoperative mortality rates, and their rate of the primary outcome decreased with time from percutaneous coronary intervention to surgery, being lowest beyond 90 days:

• 8.6% in days 1–30
• 7.5% in days 31–90
• 5.2% in days 91–180
• 5.8% in days 181–365 (P = .02).

With bare-metal stents, the event rate remained high over time:

• 8.2% in days 1–30
• 6.6% in days 31–90
• 8.1% in days 91–180
• 8.8% in days 181–365 (P = .60).

This study did not report information about perioperative antiplatelet management and was limited to first-generation drug-eluting stents. 

Saia F, Belotti LM, Guastaroba P, et al. Risk of adverse cardiac and bleeding events following cardiac and noncardiac surgery in patients with coronary stents: how important is the interplay between stent type and time from stenting to surgery? Circ Cardiovasc Qual Outcomes 2015; 9:39–47.

The study. Saia et al¹⁶ retrospectively examined predictors of periprocedural ischemic and bleeding events among cardiac and noncardiac surgical patients who had previously undergone percutaneous coronary intervention. They also assessed the risks associated with stent type and time from percutaneous coronary intervention to surgery.

Of 39,362 patients, 13,128 underwent procedures during the 5-year study period. The cumulative incidence of surgery was 3.6% at 30 days, 14% at 1 year, and 40% at 5 years after percutaneous coronary intervention. Almost 30% of the procedures were done urgently.

Results. The 30-day rate of postoperative cardiac death was 2.5%, nonfatal myocardial infarction 1.5%, and serious bleeding events 6.5%. Older drug-eluting stents were associated with higher risks of adverse events than newer drug-eluting stents at any time point (odds ratio 2.1 at 0–180 days, 1.9 at 6–12 months, and 1.45 after 12 months). Surgery performed 6 to 12 months after percutaneous coronary intervention had lower rates of adverse outcomes than surgery performed within 6 months. Beyond 6 months from percutaneous coronary intervention, bare-metal stents and newer drug-eluting stents did not have significantly different adverse event rates; however, newer drug-eluting stents appeared safer than bare-metal stents from 0 to 180 days.

Limitations of this study included lack of information regarding periprocedural antiplatelet management and a relatively small subset of newer drug-eluting stent patients.

Implications for clinical practice. These studies added to earlier work that demonstrated that the risk of perioperative adverse events differs by both the stent type and the time from percutaneous coronary intervention to noncardiac surgery. In patients with a drug-eluting stent, the risk levels off 90 days after percutaneous coronary intervention, suggesting that the previously recommended 12 months of uninterrupted dual antiplatelet therapy (per the 2014 ACC/AHA guidelines¹) may not be needed, particularly with newer-generation drug-eluting stents. Based on new evidence, the ACC/AHA guidelines regarding perioperative management of dual antiplatelet therapy in noncardiac surgery patients were updated,¹⁷ as noted below.

An update to the ACC/AHA guidelines on dual antiplatelet therapy

Levine GN, Bates ER, Bittl JA, et al. 2016 ACC/AHA guideline focused update on duration of dual antiplatelet therapy in patients with coronary artery disease. Circulation 2016 Mar 29. DOI: 10.1161/CIR.0000000000000404. [Epub ahead of print]

The 2016 update¹⁷ provides the following recommendations for patients with coronary stents who undergo noncardiac surgery:

• Delay elective surgery for 30 days after placement of a bare-metal stent (class I recommendation, level of evidence B).
• It is optimal to delay elective surgery 6 months after drug-eluting stent placement (class I recommendation, level of evidence B).
• If dual antiplatelet therapy must be discontinued, then continue aspirin if possible and restart the P2Y₁₂ inhibitor as soon as possible postoperatively (class I recommendation, level of evidence C ).
• A consensus decision among treating clinicians is useful regarding the risks of surgery and discontinuation or continuation of antiplatelet therapy (class IIa recommendation, level of evidence C).
• If dual antiplatelet therapy must be discontinued, then elective surgery should not be performed less than 30 days after bare-metal stent placement, or less than 3 months after drug-eluting stent placement (class III recommendation, level of evidence B).
• Elective surgery after drug-eluting stent placement when the P2Y₁₂ inhibitor must be discontinued may be considered 3 months after drug-eluting stent placement if the risk of surgical delay is greater than the risk of stent thrombosis (class IIb recommendation, level of evidence C).

The basic differences are the new recommendations for a minimum of 6 months of dual antiplatelet therapy as opposed to 12 months after drug-eluting stent placement before elective noncardiac surgery, and to allow surgery after 3 months (as opposed to 6 months) if the risk of delaying surgery outweighs the risk of stent thrombosis or myocardial infarction.

PERIOPERATIVE ANTICOAGULATION

The optimal perioperative management of patients with atrial fibrillation who are on warfarin is uncertain. The American College of Chest Physicians guidelines¹⁸ categorized patients with atrial fibrillation into low, moderate, and high thromboembolic risk. Based primarily on observational data, these guidelines recommended perioperative bridging anticoagulation for those at high risk but not for those at low risk. For intermediate-risk patients, there were insufficient data to make any recommendation.

Bridging may not benefit those at intermediate risk

Douketis JD, Spyropoulos AC, Kaatz S, et al; BRIDGE Investigators. Perioperative bridging anticoagulation in patients with atrial fibrillation. N Engl J Med 2015; 373:823–833.

The study. The Bridging Anticoagulation in Patients Who Require Temporary Interruption of Warfarin Therapy for an Elective Invasive Procedure or Surgery (BRIDGE) trial¹⁹ was the first randomized controlled trial to examine the effects of perioperative bridging anticoagulation in patients with atrial fibrillation without mechanical heart valves.

Results. In 1,884 patients undergoing elective surgery, the incidence of arterial thromboembolism was 0.4% in the no-bridging group and 0.3% in the bridging group (95% CI −0.6 to 0.8; P = .01 for noninferiority). Major bleeding occurred in 1.3% of patients in the no-bridging group and 3.2% in the bridging group (95% CI 0.20–0.78; P = .005 for superiority).

These results suggest that the risks of bridging therapy are greater than the benefits. Of note, the mean CHADS₂ score (1 point each for congestive heart failure, hypertension, age ≥ 75 years, and diabetes mellitus; 2 points for previous stroke or transient ischemic attack; a total score > 2 indicates significant risk of stroke) for patients enrolled in this trial was 2.3, and it may be difficult to extrapolate these results to the limited number of patients at highest risk, ie, who have a CHADS₂ score of 5 or 6. Also, this study did not address patients with arterial or venous thromboembolism.

Implications for clinical practice. Despite the limitations noted above, this study does provide guidance for management of the intermediate-risk group with atrial fibrillation as defined by the American College of Chest Physicians: a no-bridging strategy is the best option.

Perioperative medicine is an evolving field with a rapidly growing body of literature. Because physicians and patients are often concerned about cardiac risk, we focus this review on perioperative cardiology.

The information we present here is derived from presentations at the Perioperative Medicine Summit and the annual meetings of the Society of Hospital Medicine and Society of General Internal Medicine in 2016. We surveyed perioperative literature from January 2015 through March 2016 and chose the final articles by consensus, based on relevance to clinicians who provide preoperative evaluations and postoperative care to surgical patients.

We have divided this review into four sections:

• Preoperative cardiac risk assessment
• Medical therapy to reduce postoperative cardiac complications (beta-blockers, statins, and angiotensin II receptor blockers [ARBs])
• Perioperative management of patients with a coronary stent on antiplatelet therapy
• Perioperative bridging anticoagulation.

PREOPERATIVE ASSESSMENT OF CARDIAC RISK

Functionally independent patients do better

Visnjevac O, Davari-Farid S, Lee J, et al. The effect of adding functional classification to ASA status for predicting 30-day mortality. Anesth Analg 2015; 121:110–116.

Functional capacity is an independent predictor of perioperative death and is included in the algorithm of the current joint American College of Cardiology/American Heart Association (ACC/AHA) guidelines,¹ but it is not in the Revised Cardiac Risk Index² or the American Society of Anesthesiologists (ASA) classification.³

The study. Visnjevac et al⁴ performed a retrospective, observational cohort study of 12,324 patients who underwent noncardiac surgery, stratifying rates of all-cause mortality and 30-day postoperative complications based on ASA class and functional capacity.

The ASA physical status classification is defined as:

• 1—Normal healthy patient
• 2—Patient with mild systemic disease
• 3—Patient with severe systemic disease
• 4—Patient with severe systemic disease that is a constant threat to life
• 5—Moribund patient not expected to survive without surgery.

Functional capacity was defined as the ability to perform all activities of daily living. It was prospectively assessed during the patient interview by pre-anesthesia personnel and entered into the database of the Veterans Affairs Surgical Quality Improvement Program.

Results. Within each ASA class, the mortality rate was significantly lower for functionally independent patients than for partially or fully dependent patients:

• In class 2—odds ratio (OR) 0.14 for functionally independent patients
• In class 3—OR 0.29 for functionally independent patients
• In class 4—OR 0.5 for functionally independent patients.

The mortality rate was higher for dependent patients than for independent patients who were one ASA class higher, despite the higher class having greater rates of comorbidity.

Adding functional capacity to the ASA classification improved the area under the receiver operating curve from 0.811 to 0.848 (a perfect test would have a value of 1.0), suggesting that physicians should incorporate functional capacity into their preoperative evaluation, perhaps by increasing a patient’s ASA class to the next higher class if he or she is functionally dependent.

Angina portends poor outcomes

Pandey A, Sood A, Sammon JD, et al. Effect of preoperative angina pectoris on cardiac outcomes in patients with previous myocardial infarction undergoing major noncardiac surgery (data from ACS-NSQIP). Am J Cardiol 2015; 115:1080–1084.

Coronary artery disease is a risk factor for adverse perioperative outcomes, but the risk varies depending on whether the patient has had a myocardial infarction (and how long ago) and whether he or she has anginal symptoms (and how severe they are).

The study. Pandey et al⁵ used data from the American College of Surgeons National Surgical Quality Improvement Program to evaluate the impact of stable angina in 1,568 patients who underwent noncardiac surgery after a myocardial infarction.

Results. Postoperative myocardial infarction or cardiac arrest occurred in 5.5% of patients. The incidence was significantly greater in those who had anginal symptoms before surgery than in those without symptoms (8.4% vs 5%, P = .035); reintervention rates and length of stay were also higher in this group. In multivariate analysis, preoperative angina remained a significant predictor of postoperative myocardial infarction (OR 2.49, 95% confidence interval [CI] 1.20–5.81) and re­intervention (OR 2.4, 95% CI 1.44–3.82.

The authors cautioned against relying on predictive tools such as the Revised Cardiac Risk Index that do not consider stable angina and previous myocardial infarction as separate independent risk factors.

Implications for clinical practice. While functional capacity is an integral part of the ACC/AHA guideline algorithm,¹ the findings of these two studies suggest that other current tools to calculate perioperative risk (ASA class and Revised Cardiac Risk Index) could be improved by including functional capacity and stable angina.

PERIOPERATIVE MEDICAL THERAPY

Beta-blockers help only those at high risk and may harm others

Friedell ML, Van Way CW 3rd, Freyberg RW, Almenoff PL. ß-blockade and operative mortality in noncardiac surgery: harmful or helpful? JAMA Surg 2015; 150:658–663.

Beta-blockers have been used perioperatively for nearly 2 decades to try to reduce rates of postoperative major adverse cardiovascular events. However, in view of recent trials, fewer patients are likely to benefit from this intervention than has been thought.

The study. Friedell et al⁶ retrospectively analyzed data from 343,645 patients in Veterans Affairs hospitals to determine the effect of beta-blockers on major adverse cardiac event rates after major noncardiac surgery. Beta-blockers were considered to have been used perioperatively if given any time between 8 hours before and 24 hours after surgery. The outcome studied was the mortality rate at 30 days.

The authors derived a novel risk score and used multivariate analysis to attempt to adjust for confounding factors. The risk score was based on four risk factors identified a priori:

• Serum creatinine level > 2.0 mg/dL
• Coronary artery disease
• Diabetes
• Surgery in a major body cavity (abdomen or chest).

Results. In this cohort, 43.2% of patients had received a beta-blocker. The unadjusted mortality rates by risk category for patients receiving or not receiving a beta-blocker were:

• No risk factors: 1.0% with a beta-blocker vs 0.6% without
• One or two risk factors: 1.7% vs 1.5%
• Three or four risk factors: 2.3% vs 4.5%.

After adjustment for confounding factors, the 30-day mortality rate was higher in low-risk patients and lower in high-risk patients who received beta-blockers. Odds ratios for death in beta-blocker users (entire cohort) by risk category were:

• No risk factors: 1.19
• One or two risk factors 0.97
• Three or four risk factors 0.76.

In the 3.8% of the total cohort who underwent cardiac surgery, beta-blockers had no significant effect—beneficial or harmful—in any risk group.

Jørgensen ME, Hlatky MA, Køber L, et al. ß-blocker-associated risks in patients with uncomplicated hypertension undergoing noncardiac surgery. JAMA Intern Med 2015; 175:1923–1931.

The study. Jørgensen et al⁷ investigated the association between chronic beta-blocker use for the treatment of hypertension and 30-day rates of mortality and major adverse cardiac events. Eligible patients (N = 55,320) were at least 20 years old and were undergoing any type of noncardiac surgery. The authors established that hypertension was present through use of an algorithm based on the International Classification of Diseases (10th edition). Patients with existing cardiovascular disease and renal disease were excluded. The authors used multivariate analysis to adjust for confounding factors.

Results. Twenty-six percent of the patients were on chronic beta-blocker therapy for hypertension. The mortality rate at 30 days was 1.93% in patients treated with a beta-blocker alone or in combination with other antihypertensive drugs; the rate was 1.32% for patients receiving any combination of renin-angiotensin system inhibitor, calcium antagonist, or thiazide, but no beta-blocker. Similarly, the 30-day major adverse cardiac event rates were 1.32% with beta-blockers and 0.84% without beta-blockers.

In subgroup analysis, each medication combination that included a beta-blocker was associated with higher rates of death and major adverse cardiac events than the same combination without a beta-blocker. Odds ratios for major adverse cardiac events with beta-blocker combinations ranged from 1.22 to 2.16 compared with regimens with no beta-blocker.

Implications for clinical practice. These two studies added to a growing chorus of concerns about the value and safety of beta-blockers in surgical patients. Friedell et al⁶ made an observation that was remarkably similar to one reported by Lindenauer et al⁸ in 2005: when patients were stratified by baseline risk of death, only those with the highest baseline risk benefited from beta-blocker therapy. Those in the lowest risk group actually were harmed by beta-blocker use, ie, the mortality rate was higher.

More interesting is the novel observation by Jørgensen et al⁷ that even in patients with no known cardiovascular disease who are on chronic beta-blocker therapy—presumably on stable doses and not solely for perioperative risk reduction—rates of mortality and major adverse cardiac events were higher than for patients not on chronic beta-blocker therapy.

The current studies support a cautious, selective approach to the perioperative use of beta-blockers—they should be used only in high-risk patients undergoing high-risk surgery, as has been proposed by the ACC/AHA.¹

Statins protect

Antoniou GA, Hajibandeh S, Hajibandeh S, Vallabhaneni SR, Brennan JA, Torella F. Meta-analysis of the effects of statins on perioperative outcomes in vascular and endovascular surgery. J Vasc Surg 2015; 61:519–532.

The study⁹ was a comprehensive meta-analysis of randomized controlled trials and observational studies of the effects of HMG-CoA reductase inhibitors (statins) on perioperative outcomes in patients undergoing vascular surgery (but not for intracranial or coronary artery disease). Twenty-four studies were included, 4 randomized controlled trials and 20 observational studies (including 16 cohort and 4 case-controlled studies), with a total of 22,536 patients, 8,052 receiving statins and 15,484 not receiving statins.

Results. Although there was no significant difference in cardiovascular mortality rates, patients receiving statins had significantly lower rates of all-cause mortality, myocardial infarction, stroke, and a composite of myocardial infarction, stroke, and death at 30 days postoperatively than patients not receiving statins. Additionally, there was no difference in the incidence of kidney injury between groups. The possibility of publication bias was thought to be low for all of these outcomes.

Berwanger O, Le Manach Y, Suzumura EA, et al. Association between pre-operative statin use and major cardiovascular complications among patients undergoing non-cardiac surgery: the VISION study. Eur Heart J 2016; 37:177–185.

The study. The Vascular Events in Non-cardiac Surgery Patients Cohort Evaluation (VISION) study^10,11 was an international prospective cohort study of more than 40,000 patients age 45 and older undergoing major noncardiac surgery with either general or regional anesthesia. Postoperative troponin measurements were obtained in all patients 6 to 12 hours after surgery and for the first 3 postoperative days. The authors evaluated the effect of preoperative statin use on cardiovascular outcomes at 30 days after surgery using a multivariate logistic model and propensity score analysis to correct for confounding factors. Statin use was defined as exposure within 7 days before surgery or 3 days after.

Results. In the 15,478 patients included in the analysis, statin use conferred a significant reduction in the primary outcome (composite of all-cause mortality, myocardial injury after noncardiac surgery, or stroke); the absolute risk reduction was 2.0%. Statin users also had a significantly lower risk of all-cause mortality, cardiovascular mortality, and myocardial injury after noncardiac surgery, but not of postoperative myocardial infarction or stroke. This analysis did not address the type of statin, dosing, or safety markers such as liver and muscle function.

Implications for clinical practice. With largely observational data and a few small randomized trials, these meta-analyses provide important information with respect to perioperative cardiovascular protection by statins. Starting a statin before surgery and continuing it perioperatively seems appropriate in patients at high risk (as recommended by the ACC/AHA guidelines¹). Based on other data, the benefit may be evident in as little as 5 days, as this is when statins appear to reach their plateau with regard to their vascular pleiotropic effects.¹² The incidence of adverse effects of statins, including muscle and liver injury, appears to be low in the perioperative setting.¹³

Given the inconsistent data regarding perioperative beta-blocker therapy, statins may very well be the most important perioperative medication with respect to cardiovascular risk reduction. However, a large randomized trial would help to confirm this belief.

Restart angiotensin II receptor blockers soon after surgery

Lee SM, Takemoto S, Wallace AW. Association between withholding angiotensin receptor blockers in the early postoperative period and 30-day mortality: a cohort study of the Veterans Affairs Healthcare System. Anesthesiology 2015; 123:288–306.

A concern about perioperative use of ARBs is that they impair the renin-angiotensin-aldosterone system, which maintains blood pressure under general anesthesia. ARB-induced intraoperative hypotension is particularly difficult to control, as it is often refractory to treatment with conventional adrenergic vasopressors.

The study. Lee et al¹⁴ conducted a retrospective cohort trial to evaluate the effects of continuing to withhold ARBs postoperatively. Of the 30,173 patients admitted for surgery in the Veterans Affairs system from 1999 through 2011 who were taking an ARB before surgery and who met the inclusion criteria, 10,205 (33.8%) were not restarted on their medication by postoperative day 2.

Results. The mortality rate at 30 days was higher in those whose ARBs were withheld than in those in whom it was resumed, with a multivariable-adjusted hazard ratio of 1.74 (95% CI 1.47–2.06; P < .001). The risk of withholding ARBs was more pronounced in younger patients (hazard ratio 2.52; 95% CI 1.69–3.76 in those under age 60) than in older patients (hazard ratio 1.42, 95% CI 1.09–1.85 in those over age 75).

Implications for clinical practice. While not addressing whether to continue or withhold ARBs preoperatively, this retrospective study presented evidence that delay in resuming chronic ARB therapy after surgery was common and appeared to be associated with a higher 30-day mortality rate. The ACC/AHA guidelines¹ state:

• Continuing angiotensin-converting enzyme (ACE) inhibitors or ARBs perioperatively is reasonable (class IIa recommendation, level of evidence B) (Table 1).
• If an ACE inhibitor or ARB is withheld before surgery, it is reasonable to restart it postoperatively as soon as clinically feasible (class IIa recommendation, level of evidence C).

Close attention to medication reconciliation in the postoperative period is necessary to facilitate early resumption of ARBs.

CORONARY STENTS AND ANTIPLATELET THERAPY IN NONCARDIAC SURGERY PATIENTS

Considerations in the management of noncardiac surgery patients with stents include risks of stent thrombosis, bleeding, and potentially delaying procedures to continue uninterrupted dual antiplatelet therapy. Evidence is evolving regarding the risks of perioperative complications in patients with bare-metal stents and drug-eluting stents, as well as the optimal timing before noncardiac surgery.

Bare-metal vs drug-eluting stents

Bangalore S, Silbaugh TS, Normand SL, Lovett AF, Welt FG, Resnic FS. Drug-eluting stents versus bare metal stents prior to noncardiac surgery. Catheter Cardiovasc Interv 2015; 85:533–541.

The study. Bangalore et al¹⁵ compared the safety of drug-eluting vs bare-metal stents in noncardiac surgery patients and investigated adverse events stratified by time since stent placement. This was a retrospective observational study of 8,415 patients in the Massachusetts claims database who underwent noncardiac surgery 1 year or less after percutaneous coronary intervention.

Results. There was no significant difference in the incidence of the primary outcome (composite of death, myocardial infarction, and bleeding) between the two groups.

With drug-eluting stents, patients had lower 30-day postoperative mortality rates, and their rate of the primary outcome decreased with time from percutaneous coronary intervention to surgery, being lowest beyond 90 days:

• 8.6% in days 1–30
• 7.5% in days 31–90
• 5.2% in days 91–180
• 5.8% in days 181–365 (P = .02).

With bare-metal stents, the event rate remained high over time:

• 8.2% in days 1–30
• 6.6% in days 31–90
• 8.1% in days 91–180
• 8.8% in days 181–365 (P = .60).

This study did not report information about perioperative antiplatelet management and was limited to first-generation drug-eluting stents. 

Saia F, Belotti LM, Guastaroba P, et al. Risk of adverse cardiac and bleeding events following cardiac and noncardiac surgery in patients with coronary stents: how important is the interplay between stent type and time from stenting to surgery? Circ Cardiovasc Qual Outcomes 2015; 9:39–47.

The study. Saia et al¹⁶ retrospectively examined predictors of periprocedural ischemic and bleeding events among cardiac and noncardiac surgical patients who had previously undergone percutaneous coronary intervention. They also assessed the risks associated with stent type and time from percutaneous coronary intervention to surgery.

Of 39,362 patients, 13,128 underwent procedures during the 5-year study period. The cumulative incidence of surgery was 3.6% at 30 days, 14% at 1 year, and 40% at 5 years after percutaneous coronary intervention. Almost 30% of the procedures were done urgently.

Results. The 30-day rate of postoperative cardiac death was 2.5%, nonfatal myocardial infarction 1.5%, and serious bleeding events 6.5%. Older drug-eluting stents were associated with higher risks of adverse events than newer drug-eluting stents at any time point (odds ratio 2.1 at 0–180 days, 1.9 at 6–12 months, and 1.45 after 12 months). Surgery performed 6 to 12 months after percutaneous coronary intervention had lower rates of adverse outcomes than surgery performed within 6 months. Beyond 6 months from percutaneous coronary intervention, bare-metal stents and newer drug-eluting stents did not have significantly different adverse event rates; however, newer drug-eluting stents appeared safer than bare-metal stents from 0 to 180 days.

Limitations of this study included lack of information regarding periprocedural antiplatelet management and a relatively small subset of newer drug-eluting stent patients.

Implications for clinical practice. These studies added to earlier work that demonstrated that the risk of perioperative adverse events differs by both the stent type and the time from percutaneous coronary intervention to noncardiac surgery. In patients with a drug-eluting stent, the risk levels off 90 days after percutaneous coronary intervention, suggesting that the previously recommended 12 months of uninterrupted dual antiplatelet therapy (per the 2014 ACC/AHA guidelines¹) may not be needed, particularly with newer-generation drug-eluting stents. Based on new evidence, the ACC/AHA guidelines regarding perioperative management of dual antiplatelet therapy in noncardiac surgery patients were updated,¹⁷ as noted below.

An update to the ACC/AHA guidelines on dual antiplatelet therapy

Levine GN, Bates ER, Bittl JA, et al. 2016 ACC/AHA guideline focused update on duration of dual antiplatelet therapy in patients with coronary artery disease. Circulation 2016 Mar 29. DOI: 10.1161/CIR.0000000000000404. [Epub ahead of print]

The 2016 update¹⁷ provides the following recommendations for patients with coronary stents who undergo noncardiac surgery:

• Delay elective surgery for 30 days after placement of a bare-metal stent (class I recommendation, level of evidence B).
• It is optimal to delay elective surgery 6 months after drug-eluting stent placement (class I recommendation, level of evidence B).
• If dual antiplatelet therapy must be discontinued, then continue aspirin if possible and restart the P2Y₁₂ inhibitor as soon as possible postoperatively (class I recommendation, level of evidence C ).
• A consensus decision among treating clinicians is useful regarding the risks of surgery and discontinuation or continuation of antiplatelet therapy (class IIa recommendation, level of evidence C).
• If dual antiplatelet therapy must be discontinued, then elective surgery should not be performed less than 30 days after bare-metal stent placement, or less than 3 months after drug-eluting stent placement (class III recommendation, level of evidence B).
• Elective surgery after drug-eluting stent placement when the P2Y₁₂ inhibitor must be discontinued may be considered 3 months after drug-eluting stent placement if the risk of surgical delay is greater than the risk of stent thrombosis (class IIb recommendation, level of evidence C).

The basic differences are the new recommendations for a minimum of 6 months of dual antiplatelet therapy as opposed to 12 months after drug-eluting stent placement before elective noncardiac surgery, and to allow surgery after 3 months (as opposed to 6 months) if the risk of delaying surgery outweighs the risk of stent thrombosis or myocardial infarction.

PERIOPERATIVE ANTICOAGULATION

The optimal perioperative management of patients with atrial fibrillation who are on warfarin is uncertain. The American College of Chest Physicians guidelines¹⁸ categorized patients with atrial fibrillation into low, moderate, and high thromboembolic risk. Based primarily on observational data, these guidelines recommended perioperative bridging anticoagulation for those at high risk but not for those at low risk. For intermediate-risk patients, there were insufficient data to make any recommendation.

Bridging may not benefit those at intermediate risk

Douketis JD, Spyropoulos AC, Kaatz S, et al; BRIDGE Investigators. Perioperative bridging anticoagulation in patients with atrial fibrillation. N Engl J Med 2015; 373:823–833.

The study. The Bridging Anticoagulation in Patients Who Require Temporary Interruption of Warfarin Therapy for an Elective Invasive Procedure or Surgery (BRIDGE) trial¹⁹ was the first randomized controlled trial to examine the effects of perioperative bridging anticoagulation in patients with atrial fibrillation without mechanical heart valves.

Results. In 1,884 patients undergoing elective surgery, the incidence of arterial thromboembolism was 0.4% in the no-bridging group and 0.3% in the bridging group (95% CI −0.6 to 0.8; P = .01 for noninferiority). Major bleeding occurred in 1.3% of patients in the no-bridging group and 3.2% in the bridging group (95% CI 0.20–0.78; P = .005 for superiority).

These results suggest that the risks of bridging therapy are greater than the benefits. Of note, the mean CHADS₂ score (1 point each for congestive heart failure, hypertension, age ≥ 75 years, and diabetes mellitus; 2 points for previous stroke or transient ischemic attack; a total score > 2 indicates significant risk of stroke) for patients enrolled in this trial was 2.3, and it may be difficult to extrapolate these results to the limited number of patients at highest risk, ie, who have a CHADS₂ score of 5 or 6. Also, this study did not address patients with arterial or venous thromboembolism.

Implications for clinical practice. Despite the limitations noted above, this study does provide guidance for management of the intermediate-risk group with atrial fibrillation as defined by the American College of Chest Physicians: a no-bridging strategy is the best option.

Perioperative medicine is an evolving field with a rapidly growing body of literature. Because physicians and patients are often concerned about cardiac risk, we focus this review on perioperative cardiology.

The information we present here is derived from presentations at the Perioperative Medicine Summit and the annual meetings of the Society of Hospital Medicine and Society of General Internal Medicine in 2016. We surveyed perioperative literature from January 2015 through March 2016 and chose the final articles by consensus, based on relevance to clinicians who provide preoperative evaluations and postoperative care to surgical patients.

We have divided this review into four sections:

• Preoperative cardiac risk assessment
• Medical therapy to reduce postoperative cardiac complications (beta-blockers, statins, and angiotensin II receptor blockers [ARBs])
• Perioperative management of patients with a coronary stent on antiplatelet therapy
• Perioperative bridging anticoagulation.

PREOPERATIVE ASSESSMENT OF CARDIAC RISK

Functionally independent patients do better

Visnjevac O, Davari-Farid S, Lee J, et al. The effect of adding functional classification to ASA status for predicting 30-day mortality. Anesth Analg 2015; 121:110–116.

Functional capacity is an independent predictor of perioperative death and is included in the algorithm of the current joint American College of Cardiology/American Heart Association (ACC/AHA) guidelines,¹ but it is not in the Revised Cardiac Risk Index² or the American Society of Anesthesiologists (ASA) classification.³

The study. Visnjevac et al⁴ performed a retrospective, observational cohort study of 12,324 patients who underwent noncardiac surgery, stratifying rates of all-cause mortality and 30-day postoperative complications based on ASA class and functional capacity.

The ASA physical status classification is defined as:

• 1—Normal healthy patient
• 2—Patient with mild systemic disease
• 3—Patient with severe systemic disease
• 4—Patient with severe systemic disease that is a constant threat to life
• 5—Moribund patient not expected to survive without surgery.

Functional capacity was defined as the ability to perform all activities of daily living. It was prospectively assessed during the patient interview by pre-anesthesia personnel and entered into the database of the Veterans Affairs Surgical Quality Improvement Program.

Results. Within each ASA class, the mortality rate was significantly lower for functionally independent patients than for partially or fully dependent patients:

• In class 2—odds ratio (OR) 0.14 for functionally independent patients
• In class 3—OR 0.29 for functionally independent patients
• In class 4—OR 0.5 for functionally independent patients.

The mortality rate was higher for dependent patients than for independent patients who were one ASA class higher, despite the higher class having greater rates of comorbidity.

Adding functional capacity to the ASA classification improved the area under the receiver operating curve from 0.811 to 0.848 (a perfect test would have a value of 1.0), suggesting that physicians should incorporate functional capacity into their preoperative evaluation, perhaps by increasing a patient’s ASA class to the next higher class if he or she is functionally dependent.

Angina portends poor outcomes

Pandey A, Sood A, Sammon JD, et al. Effect of preoperative angina pectoris on cardiac outcomes in patients with previous myocardial infarction undergoing major noncardiac surgery (data from ACS-NSQIP). Am J Cardiol 2015; 115:1080–1084.

Coronary artery disease is a risk factor for adverse perioperative outcomes, but the risk varies depending on whether the patient has had a myocardial infarction (and how long ago) and whether he or she has anginal symptoms (and how severe they are).

The study. Pandey et al⁵ used data from the American College of Surgeons National Surgical Quality Improvement Program to evaluate the impact of stable angina in 1,568 patients who underwent noncardiac surgery after a myocardial infarction.

Results. Postoperative myocardial infarction or cardiac arrest occurred in 5.5% of patients. The incidence was significantly greater in those who had anginal symptoms before surgery than in those without symptoms (8.4% vs 5%, P = .035); reintervention rates and length of stay were also higher in this group. In multivariate analysis, preoperative angina remained a significant predictor of postoperative myocardial infarction (OR 2.49, 95% confidence interval [CI] 1.20–5.81) and re­intervention (OR 2.4, 95% CI 1.44–3.82.

The authors cautioned against relying on predictive tools such as the Revised Cardiac Risk Index that do not consider stable angina and previous myocardial infarction as separate independent risk factors.

Implications for clinical practice. While functional capacity is an integral part of the ACC/AHA guideline algorithm,¹ the findings of these two studies suggest that other current tools to calculate perioperative risk (ASA class and Revised Cardiac Risk Index) could be improved by including functional capacity and stable angina.

PERIOPERATIVE MEDICAL THERAPY

Beta-blockers help only those at high risk and may harm others

Friedell ML, Van Way CW 3rd, Freyberg RW, Almenoff PL. ß-blockade and operative mortality in noncardiac surgery: harmful or helpful? JAMA Surg 2015; 150:658–663.

Beta-blockers have been used perioperatively for nearly 2 decades to try to reduce rates of postoperative major adverse cardiovascular events. However, in view of recent trials, fewer patients are likely to benefit from this intervention than has been thought.

The study. Friedell et al⁶ retrospectively analyzed data from 343,645 patients in Veterans Affairs hospitals to determine the effect of beta-blockers on major adverse cardiac event rates after major noncardiac surgery. Beta-blockers were considered to have been used perioperatively if given any time between 8 hours before and 24 hours after surgery. The outcome studied was the mortality rate at 30 days.

The authors derived a novel risk score and used multivariate analysis to attempt to adjust for confounding factors. The risk score was based on four risk factors identified a priori:

• Serum creatinine level > 2.0 mg/dL
• Coronary artery disease
• Diabetes
• Surgery in a major body cavity (abdomen or chest).

Results. In this cohort, 43.2% of patients had received a beta-blocker. The unadjusted mortality rates by risk category for patients receiving or not receiving a beta-blocker were:

• No risk factors: 1.0% with a beta-blocker vs 0.6% without
• One or two risk factors: 1.7% vs 1.5%
• Three or four risk factors: 2.3% vs 4.5%.

After adjustment for confounding factors, the 30-day mortality rate was higher in low-risk patients and lower in high-risk patients who received beta-blockers. Odds ratios for death in beta-blocker users (entire cohort) by risk category were:

• No risk factors: 1.19
• One or two risk factors 0.97
• Three or four risk factors 0.76.

In the 3.8% of the total cohort who underwent cardiac surgery, beta-blockers had no significant effect—beneficial or harmful—in any risk group.

Jørgensen ME, Hlatky MA, Køber L, et al. ß-blocker-associated risks in patients with uncomplicated hypertension undergoing noncardiac surgery. JAMA Intern Med 2015; 175:1923–1931.

The study. Jørgensen et al⁷ investigated the association between chronic beta-blocker use for the treatment of hypertension and 30-day rates of mortality and major adverse cardiac events. Eligible patients (N = 55,320) were at least 20 years old and were undergoing any type of noncardiac surgery. The authors established that hypertension was present through use of an algorithm based on the International Classification of Diseases (10th edition). Patients with existing cardiovascular disease and renal disease were excluded. The authors used multivariate analysis to adjust for confounding factors.

Results. Twenty-six percent of the patients were on chronic beta-blocker therapy for hypertension. The mortality rate at 30 days was 1.93% in patients treated with a beta-blocker alone or in combination with other antihypertensive drugs; the rate was 1.32% for patients receiving any combination of renin-angiotensin system inhibitor, calcium antagonist, or thiazide, but no beta-blocker. Similarly, the 30-day major adverse cardiac event rates were 1.32% with beta-blockers and 0.84% without beta-blockers.

In subgroup analysis, each medication combination that included a beta-blocker was associated with higher rates of death and major adverse cardiac events than the same combination without a beta-blocker. Odds ratios for major adverse cardiac events with beta-blocker combinations ranged from 1.22 to 2.16 compared with regimens with no beta-blocker.

Implications for clinical practice. These two studies added to a growing chorus of concerns about the value and safety of beta-blockers in surgical patients. Friedell et al⁶ made an observation that was remarkably similar to one reported by Lindenauer et al⁸ in 2005: when patients were stratified by baseline risk of death, only those with the highest baseline risk benefited from beta-blocker therapy. Those in the lowest risk group actually were harmed by beta-blocker use, ie, the mortality rate was higher.

More interesting is the novel observation by Jørgensen et al⁷ that even in patients with no known cardiovascular disease who are on chronic beta-blocker therapy—presumably on stable doses and not solely for perioperative risk reduction—rates of mortality and major adverse cardiac events were higher than for patients not on chronic beta-blocker therapy.

The current studies support a cautious, selective approach to the perioperative use of beta-blockers—they should be used only in high-risk patients undergoing high-risk surgery, as has been proposed by the ACC/AHA.¹

Statins protect

Antoniou GA, Hajibandeh S, Hajibandeh S, Vallabhaneni SR, Brennan JA, Torella F. Meta-analysis of the effects of statins on perioperative outcomes in vascular and endovascular surgery. J Vasc Surg 2015; 61:519–532.

The study⁹ was a comprehensive meta-analysis of randomized controlled trials and observational studies of the effects of HMG-CoA reductase inhibitors (statins) on perioperative outcomes in patients undergoing vascular surgery (but not for intracranial or coronary artery disease). Twenty-four studies were included, 4 randomized controlled trials and 20 observational studies (including 16 cohort and 4 case-controlled studies), with a total of 22,536 patients, 8,052 receiving statins and 15,484 not receiving statins.

Results. Although there was no significant difference in cardiovascular mortality rates, patients receiving statins had significantly lower rates of all-cause mortality, myocardial infarction, stroke, and a composite of myocardial infarction, stroke, and death at 30 days postoperatively than patients not receiving statins. Additionally, there was no difference in the incidence of kidney injury between groups. The possibility of publication bias was thought to be low for all of these outcomes.

Berwanger O, Le Manach Y, Suzumura EA, et al. Association between pre-operative statin use and major cardiovascular complications among patients undergoing non-cardiac surgery: the VISION study. Eur Heart J 2016; 37:177–185.

The study. The Vascular Events in Non-cardiac Surgery Patients Cohort Evaluation (VISION) study^10,11 was an international prospective cohort study of more than 40,000 patients age 45 and older undergoing major noncardiac surgery with either general or regional anesthesia. Postoperative troponin measurements were obtained in all patients 6 to 12 hours after surgery and for the first 3 postoperative days. The authors evaluated the effect of preoperative statin use on cardiovascular outcomes at 30 days after surgery using a multivariate logistic model and propensity score analysis to correct for confounding factors. Statin use was defined as exposure within 7 days before surgery or 3 days after.

Results. In the 15,478 patients included in the analysis, statin use conferred a significant reduction in the primary outcome (composite of all-cause mortality, myocardial injury after noncardiac surgery, or stroke); the absolute risk reduction was 2.0%. Statin users also had a significantly lower risk of all-cause mortality, cardiovascular mortality, and myocardial injury after noncardiac surgery, but not of postoperative myocardial infarction or stroke. This analysis did not address the type of statin, dosing, or safety markers such as liver and muscle function.

Implications for clinical practice. With largely observational data and a few small randomized trials, these meta-analyses provide important information with respect to perioperative cardiovascular protection by statins. Starting a statin before surgery and continuing it perioperatively seems appropriate in patients at high risk (as recommended by the ACC/AHA guidelines¹). Based on other data, the benefit may be evident in as little as 5 days, as this is when statins appear to reach their plateau with regard to their vascular pleiotropic effects.¹² The incidence of adverse effects of statins, including muscle and liver injury, appears to be low in the perioperative setting.¹³

Given the inconsistent data regarding perioperative beta-blocker therapy, statins may very well be the most important perioperative medication with respect to cardiovascular risk reduction. However, a large randomized trial would help to confirm this belief.

Restart angiotensin II receptor blockers soon after surgery

Lee SM, Takemoto S, Wallace AW. Association between withholding angiotensin receptor blockers in the early postoperative period and 30-day mortality: a cohort study of the Veterans Affairs Healthcare System. Anesthesiology 2015; 123:288–306.

A concern about perioperative use of ARBs is that they impair the renin-angiotensin-aldosterone system, which maintains blood pressure under general anesthesia. ARB-induced intraoperative hypotension is particularly difficult to control, as it is often refractory to treatment with conventional adrenergic vasopressors.

The study. Lee et al¹⁴ conducted a retrospective cohort trial to evaluate the effects of continuing to withhold ARBs postoperatively. Of the 30,173 patients admitted for surgery in the Veterans Affairs system from 1999 through 2011 who were taking an ARB before surgery and who met the inclusion criteria, 10,205 (33.8%) were not restarted on their medication by postoperative day 2.

Results. The mortality rate at 30 days was higher in those whose ARBs were withheld than in those in whom it was resumed, with a multivariable-adjusted hazard ratio of 1.74 (95% CI 1.47–2.06; P < .001). The risk of withholding ARBs was more pronounced in younger patients (hazard ratio 2.52; 95% CI 1.69–3.76 in those under age 60) than in older patients (hazard ratio 1.42, 95% CI 1.09–1.85 in those over age 75).

Implications for clinical practice. While not addressing whether to continue or withhold ARBs preoperatively, this retrospective study presented evidence that delay in resuming chronic ARB therapy after surgery was common and appeared to be associated with a higher 30-day mortality rate. The ACC/AHA guidelines¹ state:

• Continuing angiotensin-converting enzyme (ACE) inhibitors or ARBs perioperatively is reasonable (class IIa recommendation, level of evidence B) (Table 1).
• If an ACE inhibitor or ARB is withheld before surgery, it is reasonable to restart it postoperatively as soon as clinically feasible (class IIa recommendation, level of evidence C).

Close attention to medication reconciliation in the postoperative period is necessary to facilitate early resumption of ARBs.

CORONARY STENTS AND ANTIPLATELET THERAPY IN NONCARDIAC SURGERY PATIENTS

Considerations in the management of noncardiac surgery patients with stents include risks of stent thrombosis, bleeding, and potentially delaying procedures to continue uninterrupted dual antiplatelet therapy. Evidence is evolving regarding the risks of perioperative complications in patients with bare-metal stents and drug-eluting stents, as well as the optimal timing before noncardiac surgery.

Bare-metal vs drug-eluting stents

Bangalore S, Silbaugh TS, Normand SL, Lovett AF, Welt FG, Resnic FS. Drug-eluting stents versus bare metal stents prior to noncardiac surgery. Catheter Cardiovasc Interv 2015; 85:533–541.

The study. Bangalore et al¹⁵ compared the safety of drug-eluting vs bare-metal stents in noncardiac surgery patients and investigated adverse events stratified by time since stent placement. This was a retrospective observational study of 8,415 patients in the Massachusetts claims database who underwent noncardiac surgery 1 year or less after percutaneous coronary intervention.

Results. There was no significant difference in the incidence of the primary outcome (composite of death, myocardial infarction, and bleeding) between the two groups.

With drug-eluting stents, patients had lower 30-day postoperative mortality rates, and their rate of the primary outcome decreased with time from percutaneous coronary intervention to surgery, being lowest beyond 90 days:

• 8.6% in days 1–30
• 7.5% in days 31–90
• 5.2% in days 91–180
• 5.8% in days 181–365 (P = .02).

With bare-metal stents, the event rate remained high over time:

• 8.2% in days 1–30
• 6.6% in days 31–90
• 8.1% in days 91–180
• 8.8% in days 181–365 (P = .60).

This study did not report information about perioperative antiplatelet management and was limited to first-generation drug-eluting stents. 

Saia F, Belotti LM, Guastaroba P, et al. Risk of adverse cardiac and bleeding events following cardiac and noncardiac surgery in patients with coronary stents: how important is the interplay between stent type and time from stenting to surgery? Circ Cardiovasc Qual Outcomes 2015; 9:39–47.

The study. Saia et al¹⁶ retrospectively examined predictors of periprocedural ischemic and bleeding events among cardiac and noncardiac surgical patients who had previously undergone percutaneous coronary intervention. They also assessed the risks associated with stent type and time from percutaneous coronary intervention to surgery.

Of 39,362 patients, 13,128 underwent procedures during the 5-year study period. The cumulative incidence of surgery was 3.6% at 30 days, 14% at 1 year, and 40% at 5 years after percutaneous coronary intervention. Almost 30% of the procedures were done urgently.

Results. The 30-day rate of postoperative cardiac death was 2.5%, nonfatal myocardial infarction 1.5%, and serious bleeding events 6.5%. Older drug-eluting stents were associated with higher risks of adverse events than newer drug-eluting stents at any time point (odds ratio 2.1 at 0–180 days, 1.9 at 6–12 months, and 1.45 after 12 months). Surgery performed 6 to 12 months after percutaneous coronary intervention had lower rates of adverse outcomes than surgery performed within 6 months. Beyond 6 months from percutaneous coronary intervention, bare-metal stents and newer drug-eluting stents did not have significantly different adverse event rates; however, newer drug-eluting stents appeared safer than bare-metal stents from 0 to 180 days.

Limitations of this study included lack of information regarding periprocedural antiplatelet management and a relatively small subset of newer drug-eluting stent patients.

Implications for clinical practice. These studies added to earlier work that demonstrated that the risk of perioperative adverse events differs by both the stent type and the time from percutaneous coronary intervention to noncardiac surgery. In patients with a drug-eluting stent, the risk levels off 90 days after percutaneous coronary intervention, suggesting that the previously recommended 12 months of uninterrupted dual antiplatelet therapy (per the 2014 ACC/AHA guidelines¹) may not be needed, particularly with newer-generation drug-eluting stents. Based on new evidence, the ACC/AHA guidelines regarding perioperative management of dual antiplatelet therapy in noncardiac surgery patients were updated,¹⁷ as noted below.

An update to the ACC/AHA guidelines on dual antiplatelet therapy

Levine GN, Bates ER, Bittl JA, et al. 2016 ACC/AHA guideline focused update on duration of dual antiplatelet therapy in patients with coronary artery disease. Circulation 2016 Mar 29. DOI: 10.1161/CIR.0000000000000404. [Epub ahead of print]

The 2016 update¹⁷ provides the following recommendations for patients with coronary stents who undergo noncardiac surgery:

• Delay elective surgery for 30 days after placement of a bare-metal stent (class I recommendation, level of evidence B).
• It is optimal to delay elective surgery 6 months after drug-eluting stent placement (class I recommendation, level of evidence B).
• If dual antiplatelet therapy must be discontinued, then continue aspirin if possible and restart the P2Y₁₂ inhibitor as soon as possible postoperatively (class I recommendation, level of evidence C ).
• A consensus decision among treating clinicians is useful regarding the risks of surgery and discontinuation or continuation of antiplatelet therapy (class IIa recommendation, level of evidence C).
• If dual antiplatelet therapy must be discontinued, then elective surgery should not be performed less than 30 days after bare-metal stent placement, or less than 3 months after drug-eluting stent placement (class III recommendation, level of evidence B).
• Elective surgery after drug-eluting stent placement when the P2Y₁₂ inhibitor must be discontinued may be considered 3 months after drug-eluting stent placement if the risk of surgical delay is greater than the risk of stent thrombosis (class IIb recommendation, level of evidence C).

The basic differences are the new recommendations for a minimum of 6 months of dual antiplatelet therapy as opposed to 12 months after drug-eluting stent placement before elective noncardiac surgery, and to allow surgery after 3 months (as opposed to 6 months) if the risk of delaying surgery outweighs the risk of stent thrombosis or myocardial infarction.

PERIOPERATIVE ANTICOAGULATION

The optimal perioperative management of patients with atrial fibrillation who are on warfarin is uncertain. The American College of Chest Physicians guidelines¹⁸ categorized patients with atrial fibrillation into low, moderate, and high thromboembolic risk. Based primarily on observational data, these guidelines recommended perioperative bridging anticoagulation for those at high risk but not for those at low risk. For intermediate-risk patients, there were insufficient data to make any recommendation.

Bridging may not benefit those at intermediate risk

Douketis JD, Spyropoulos AC, Kaatz S, et al; BRIDGE Investigators. Perioperative bridging anticoagulation in patients with atrial fibrillation. N Engl J Med 2015; 373:823–833.

The study. The Bridging Anticoagulation in Patients Who Require Temporary Interruption of Warfarin Therapy for an Elective Invasive Procedure or Surgery (BRIDGE) trial¹⁹ was the first randomized controlled trial to examine the effects of perioperative bridging anticoagulation in patients with atrial fibrillation without mechanical heart valves.

Results. In 1,884 patients undergoing elective surgery, the incidence of arterial thromboembolism was 0.4% in the no-bridging group and 0.3% in the bridging group (95% CI −0.6 to 0.8; P = .01 for noninferiority). Major bleeding occurred in 1.3% of patients in the no-bridging group and 3.2% in the bridging group (95% CI 0.20–0.78; P = .005 for superiority).

These results suggest that the risks of bridging therapy are greater than the benefits. Of note, the mean CHADS₂ score (1 point each for congestive heart failure, hypertension, age ≥ 75 years, and diabetes mellitus; 2 points for previous stroke or transient ischemic attack; a total score > 2 indicates significant risk of stroke) for patients enrolled in this trial was 2.3, and it may be difficult to extrapolate these results to the limited number of patients at highest risk, ie, who have a CHADS₂ score of 5 or 6. Also, this study did not address patients with arterial or venous thromboembolism.

Implications for clinical practice. Despite the limitations noted above, this study does provide guidance for management of the intermediate-risk group with atrial fibrillation as defined by the American College of Chest Physicians: a no-bridging strategy is the best option.

Managing heart failure is a challenge. To aid clinicians in this task, the American College of Cardiology Foundation (ACC) and the American Heart Association (AHA) publish evidence-based guidelines, most recently in 2013.¹ Since then, new drugs and devices have been shown to improve survival and reduce hospitalizations.

See related editorial

This paper reviews the ABCs of outpatient management of systolic heart failure (or heart failure with reduced ejection fraction), including the results of major trials and recommendations.

A common and serious condition

Heart failure is a debilitating syndrome that takes a significant physical and mental toll on those affected.

And it is common. An American age 40 or older faces a 20% lifetime risk of heart failure.¹ An estimated 5.1 million Americans have clinical signs and symptoms of heart failure, and 900,000 new cases are diagnosed each year.² By 2030 the prevalence of heart failure is projected to increase by 46%, and 9 million Americans will have been diagnosed with it.²

The severity of heart failure can be described using either the functional classification devised by the New York Heart Association (NYHA; Table 1) or the stages defined by the ACC and AHA.^1,3 Though survival rates have improved, there is a direct correlation between worsening symptoms and death.⁴

Heart failure is the leading cause of hospitalizations annually. It accounts for $30 billion in healthcare costs, with direct medical costs accounting for 68% and another $1.8 billion associated with clinic visits, most often with primary care providers. By 2030, the cost is projected to increase by 127% to $69.7 billion—$244 per person in the United States.²

ACE inhibitors

The renin-angiotensin-aldosterone system has been studied for over 100 years.⁵

In heart failure with reduced ejection fraction, this system is upregulated as an adaptive mechanism to maintain hemodynamic homeostasis.^6–8 However, prolonged activation of the renin-angiotensin-aldosterone system can lead to deleterious cardiovascular effects such as myocyte hypertrophy, myocardial fibrosis, sodium conservation, and fluid overload.^8,9 Angiotensin II is a potent vasoconstrictor and plays a role in cardiovascular remodeling, leading to worsening progression of heart failure.⁶

CONSENSUS (the Cooperative North Scandinavian Enalapril Survival Study) examined the effect of the angiotensin-converting enzyme (ACE) inhibitor enalapril on survival in 253 patients with NYHA class IV heart failure. Participants were randomized to receive either enalapril or placebo. At 6 months, the mortality rate was 26% in the enalapril group vs 44% in the placebo group, an 18% absolute risk reduction and a 41% relative risk reduction (P = .002). At 12 months, the relative risk reduction in mortality was 30% (P = .001).¹⁰

SOLVD (the Study of Left Ventricular Dysfunction) extended the use of ACE inhibitors to all patients with heart failure, not just those in NYHA class IV. It randomized 1,284 patients with heart failure of any NYHA class and an ejection fraction less than 35% to receive either enalapril or placebo, and demonstrated a 16% relative risk reduction in mortality in the enalapril group, with mortality rates of 36% vs 39.7% (P = .0036).¹¹

Recommendations. The benefits of ACE inhibition have been demonstrated in patients with mild, moderate, and severe heart failure. Thus, the guidelines recommend ACE inhibitors (Table 2) for all patients with heart failure with reduced ejection fraction.¹

Angiotensin II receptor blockers

Angiotensin II receptor blockers (ARBs) (Table 3) have been proven to be suitable alternatives for patients with heart failure with reduced ejection fraction who cannot tolerate ACE inhibitors.

Val-HefT (the Valsartan HF Trial)¹² randomized 5,010 patients in a double-blind fashion to receive either valsartan or placebo, with background therapy that included beta-blockers, digoxin, diuretics, and ACE inhibitors. There was a 13% reduction of the combined primary end point of mortality and morbidity and a 24% reduction in heart failure hospitalizations in the valsartan group.¹²

Subgroup analysis compared patients on the basis of use of ACE inhibitors and beta-blockers at study entry. Valsartan had a favorable effect in the subgroups using beta-blockers alone, ACE inhibitors alone, and neither drug. However, when patients received all three (a beta-blocker, an ACE inhibitor, and valsartan), the mortality rate was significantly increased (P = .009).¹² This finding conflicted with those of other studies, which found a small benefit of combining an ACE inhibitor and an ARB.

CHARM-Added (the Candesartan in HF Assessment of Reduction in Mortality and Morbidity trial)¹³ investigated whether adding the ARB candesartan to an ACE inhibitor would improve clinical outcomes. In the study, 2,548 patients in NYHA class II, III, or IV with a left ventricular ejection fraction of less than 40% who were receiving ACE inhibitors were randomized to either candesartan or placebo. The addition of candesartan resulted in a significant reduction in cardiovascular mortality and heart failure hospitalizations, but with the downside of higher rates of hyperkalemia and serum creatinine elevation.¹³

Recommendations. The 2013 guidelines recommend that ARBs be used in patients who cannot tolerate an ACE inhibitor due to cough. However, routine combined use of ARBs, ACE inhibitors, and aldosterone antagonists is not recommended and may cause harm.¹

Aldosterone receptor antagonists

Elevated levels of aldosterone lead to fluid retention, loss of magnesium and potassium, and myocardial fibrosis.

RALES (the Randomized Aldactone Evaluation Study)¹⁴ tested the hypothesis that the aldosterone receptor antagonist spironolactone (25 mg daily) would reduce deaths from all causes in patients with severe heart failure receiving standard medications including an ACE inhibitor. RALES included 1,663 patients in NYHA class III or IV with a left ventricular ejection fraction of 35% or less, randomized to receive 25 mg of spironolactone or matching placebo. This study found a 30% relative risk reduction and an 11% absolute risk reduction in all-cause mortality, a 31% relative risk reduction and a 10% absolute risk reduction in cardiac mortality, and 30% fewer cardiac-related hospitalizations in the spironolactone group.¹⁴

Eplerenone, an aldosterone receptor antagonist that lacks the antiandrogenic side effects of spironolactone, has also been shown to be beneficial. Its efficacy in patients with left ventricular systolic dysfunction was first established in postmyocardial infarction patients.¹⁵

EMPHASIS-HF (the Eplerenone in Mild Patients Hospitalized and Survival Study in Heart Failure)¹⁶ broadened the application of eplerenone (and aldosterone antagonists in general), investigating the effects of eplerenone in 2,737 NYHA class II patients, regardless of ischemic etiology. The composite end point of cardiovascular death or heart failure hospitalization occurred in 18.3% of the eplerenone group vs 25.9% of the placebo group (P < .001). A total of 12.5% of patients in the eplerenone group died, compared with 15.5% in the placebo group (P = .008). Hospitalizations were also fewer in the eplerenone group.

Recommendations. The 2013 guidelines recommend aldosterone receptor antagonists (Table 4) for patients with NYHA class II, III, or IV heart failure who have an ejection fraction of 35% or less, to reduce morbidity and mortality (class IA recommendation).¹ The guidelines also recommend that these agents not be used in patients with renal insufficiency (serum creatinine > 2.5 mg/dL in men or > 2.0 mg/dL in women; an estimated glomerular filtration rate < 30 mL/min/1.73 m²); or a serum potassium level above 5 mmol/L.¹

Angiotensin-neprilysin inhibitor (the future)

Research has identified neprilysin as another potential target in the treatment of heart failure and has sought to combine inhibition of angiotensin and neprilysin.

Neprilysin, a neutral endopeptidase, is associated with degradation of several natural vasoactive peptides such as natriuretic peptide, bradykinin, and adrenomedullin. Neprilysin inhibition increases these substances and counters the neurohormonal overactivation that leads to vasoconstriction, sodium retention, and cardiac remodeling.¹⁷

The ARB valsartan has been combined with the neprilysin inhibitor sacubitril to create the first angiotensin-neprilysin inhibitor (ARNI) (Table 5). The combination was selected to minimize the potential for angioedema.

PARADIGM-HF (the Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure trial)¹⁷ examined whether combined angiotensin-neprilysin inhibition was superior to ACE inhibition alone with enalapril in patients with chronic heart failure.

In PARADIGM-HF, 10,521 patients with NYHA class II, III, or IV heart failure were randomized to receive either sacubitril-valsartan or enalapril. The group receiving sacubitril-valsartan had significantly fewer deaths from cardiovascular causes and heart failure hospitalizations.¹⁷ An improvement in quality of life and NYHA functional class was also observed in the sacubitril-valsartan group.¹⁷

Sacubitril-valsartan underwent priority review by the US Food and Drug Administration and has been approved. Currently, it is indicated for the treatment of heart failure with reduced ejection fraction and NYHA class II, III, or IV symptoms. It should be avoided in patients who have previously experienced angioedema with an ACE inhibitor or ARB, in patients receiving aliskiren for diabetes, and in patients with hypersensitivity reactions to either of its components. Simultaneous use of sacubitril-valsartan and an ACE inhibitor should be avoided, and a washout period is recommended when transitioning from an ACE inhibitor to this combined agent.

Beta-blockers

In heart failure, there is increased sympathetic activation and associated elevations in norepinephrine levels, which may lead to deleterious long-term effects on cardiac function and structure. Beta-adrenergic receptor blockade is now known to be cardioprotective, but it was not always so; beta-blockers used to be contraindicated in patients with heart failure.

An early experience using beta-blockers in heart failure was described in 1975.^18,19 The first study to report a survival benefit of treating systolic heart failure with a beta-blocker was published in 1979.²⁰ Later, small controlled trials demonstrated a reduction in heart failure symptoms and improvement in left ventricular function and in NYHA functional class.²¹ Larger clinical trials have demonstrated a tremendous survival benefit with beta-blockers in heart failure, specifically carvedilol, extended-release metoprolol, and bisoprolol.

The US Carvedilol Heart Failure Study Group trial²² evaluated whether beta-blocker use in heart failure patients would reduce the rates of morbidity and mortality.²² The trial included 1,094 patients with symptomatic heart failure for at least 3 months and a left ventricular ejection fraction of 35% or less on background therapy including vasodilators, ACE inhibitors, and digoxin. Patients were randomized to receive either carvedilol or placebo. Carvedilol use was associated with a dramatic 65% risk reduction in mortality (7.8% with placebo vs 3.2% with carvedilol, P < .001) and a 27% risk reduction in hospitalizations (19.6% vs 14.1%, P = .036), leading to early trial termination.

CIBIS-II (the Cardiac Insufficiency Bisoprolol Study II)²³ investigated the effects of beta-blockers on survival and morbidity. CIBIS-II included 2,647 NYHA class III or IV patients with a left ventricular ejection fraction less than 35% on background medical therapy that included diuretics and ACE inhibitors. This trial was also terminated early, after demonstrating a significant survival benefit with bisoprolol.

MERIT-HF (the Metoprolol Extended Release Randomized Intervention Trial in Congestive Heart Failure)²⁴ evaluated if once-daily metoprolol would lower mortality rates  in patients with symptomatic heart failure. The study enrolled 3,991 NYHA class II–IV patients with chronic heart failure and a left ventricular ejection fraction of 40% or less. Like the previous two beta-blocker trials, MERIT-HF was terminated early, as it demonstrated a 34% reduction in all-cause mortality (7.2% risk of death per patient-year vs 11.0%, P = .00009).

The beta-blocker trials have shown that when added to background therapy, beta-blockers improve survival and reduce hospitalizations. However, when prescribing a beta-blocker, it is important to understand that not all beta-blockers are equal in the treatment of heart failure.

COMET (the Carvedilol or Metoprolol European Trial)²⁵ was the only head-to-head randomized control trial evaluating clinical outcomes in patients receiving carvedilol or metoprolol tartrate (not metoprolol succinate). In COMET, 1,511 patients with NYHA class II, III, or IV heart failure with a left ventricular ejection fraction of 35% or less were randomized to carvedilol or metoprolol tartrate. The primary end point of all-cause mortality occurred in 34% of the carvedilol group and 40% of the metoprolol tartrate group (P = .0017). There was no significant difference with regard to the composite end point of mortality and all-cause admissions.

Recommendations. The 2013 guidelines give a class IA recommendation for starting a beta-blocker (carvedilol, bisoprolol, or metoprolol succinate, Table 6) in patients with current or prior symptoms of heart failure.¹ Beta-blockers should be initiated with caution or avoided in patients with acutely decompensated heart failure with evidence of fluid overload.

Brain-type natriuretic peptide

Brain-type natriuretic peptide (BNP) or its amino-terminal cleavage product (NT-proBNP) originates in cardiomyocytes and is released by several triggers, most commonly cardiomyocyte stretch in the setting of volume or pressure overload.²⁶ The biologic significance of BNP includes natriuresis and vasodilation, renin-angiotensin system inhibition, and sympathetic nervous system modulation.²⁶

TIME-CHF (the Trial of Intensified vs. Standard Medical Therapy in Elderly Patients With Congestive HF)²⁷ investigated whether 18-month outcomes would be better if treatment were guided by N-terminal BNP levels rather than by symptoms. The BNP-guided strategy was not associated with a reduction in hospitalization or a survival benefit.

BATTLESCARRED (the NT-proBNP-Assisted Treatment to Lessen Serial Cardiac Readmissions and Death trial)²⁸ in 2009 showed that a BNP-guided management strategy significantly reduced mortality rates in patients under age 75 compared with standard medical therapy.

PROTECT (the Use of NT-proBNP Testing to Guide HF Therapy in the Outpatient Setting study)²⁹ also showed that a BNP-guided strategy was superior to usual care and was associated with reduced cardiovascular events and improved quality of life.²⁹

GUIDE IT-HF (the Guiding Evidence Based Therapy Using Biomarker Intensified Treatment in Heart Failure study), currently ongoing, is designed to assess the safety, efficacy and cost-effectiveness of a biomarker-guided strategy in 1,100 high-risk patients with heart failure with reduced ejection fraction. 

Recommendations. The 2013 ACC/AHA guidelines give a class IA recommendation for the use of BNP to support clinical decision-making, particularly in cases of clinical uncertainty.¹ BNP can also be used to establish prognosis or disease severity in chronic heart failure and to achieve optimal dosage of goal-directed medical therapy for euvolemic patients followed in a structured heart failure program.¹

Heart failure clinics

Continuity of care upon discharge from the hospital is currently in a state of evolution. Those diagnosed with heart failure can now experience more comprehensive posthospital care by virtue of disease management clinics. The name may vary by institution, but whether it is called a “diuresis clinic,” “bridge clinic,” or “heart failure clinic,” the goal is to improve guideline-driven care, educate the patient, and reduce heart failure hospitalizations. Heart failure clinics are designed to provide a smooth transition from inpatient to outpatient care and to encourage patient self-accountability in health maintenance thereafter.

Studies have shown that heart failure clinics are associated with better medication dosing, fewer hospitalizations, and lower healthcare costs.^30–32

Chronotropy: I_f inhibition

An elevated resting heart rate has been shown to be associated with increased cardiovascular morbidity and mortality.³³ Studies have shown that slowing the heart rate improves myocardial contraction and energy supply and reduces energy expenditure.³⁴ Ivabradine, a selective I_f (the f is for “funny”) channel inhibitor, slows the heart rate without other known cardiovascular effects.

SHIFT (the Systolic Heart Failure Treatment With the I_f Inhibitor Ivabradine Trial)³⁵ investigated whether isolated heart rate reduction with ivabradine would reduce adverse clinical outcomes in patients with symptomatic heart failure. SHIFT randomized 6,505 patients with a left ventricular ejection fraction of 35% or less, in sinus rhythm, with a heart rate of at least 70 beats per minute, on optimal medical therapy, and hospitalized within 12 months of enrollment to receive ivabradine or placebo. The primary end point was a composite of cardiovascular mortality and hospital admission for worsening heart failure. Outcomes varied by heart rates achieved, with the best outcomes in those with the lowest heart rates at trial conclusion.

Ivabradine (Table 7) is indicated for patients with symptomatic heart failure with a left ventricular ejection fraction less than 35%, in sinus rhythm, with a resting heart rate of at least 70 beats per minute, and either on a maximally tolerated beta-blocker or with a contraindication to beta-blockers.

Ivabradine should be avoided in patients who are in acute decompensated heart failure or are hypotensive (blood pressure < 90/50 mm Hg), as well as in patients with a significant conduction abnormality (sick sinus syndrome, sinoatrial block, third-degree atrioventricular block), hepatic impairment, or bradycardia (resting heart rate < 60 beats per minute).

Digoxin

Digoxin has been used in treating systolic heart failure for more than 70 years.^36,37

DIG (Digoxin Investigative Group trial)³⁸ evaluated the long-term effect of digoxin on rates of mortality and hospitalization for heart failure over a 3-year period. In patients with  a left ventricular ejection fraction less than 45%, digoxin had no effect on overall mortality when combined with diuretics and ACE inhibitors. However, the risk of hospitalization for worsening heart failure was significantly reduced with digoxin treatment.³⁸

Recommendations. Digoxin should be considered when patients are on guideline-recommended therapy but heart failure symptoms persist. It is commonly initiated at a dose of 0.125 to 0.25 mg. The target therapeutic range for digoxin is 0.5 to 0.9 ng/mL.¹ Digoxin toxicity can occur in patients with renal impairment, hypokalemia, hypomagnesemia, and hypothyroidism.

The 2013 ACC/AHA guidelines give a class IIA recommendation (treatment is “reasonable”) for digoxin in patients with heart failure with reduced ejection fraction unless contraindicated, to decrease hospitalizations for heart failure.¹

Diuretics

Clinical manifestations of volume overload in patients with heart failure are from excess salt and water retention leading to inappropriate volume expansion in both the vascular and extravascular space. Diuretics (Table 8) are the foundation of heart failure treatment. Most patients are first initiated on a combination of a loop diuretic and a low-sodium diet to improve symptoms.

The 2013 ACC/AHA guidelines give a class I recommendation for diuretics in patients with heart failure with reduced ejection fraction who have evidence of fluid retention, unless contraindicated, to improve symptoms.¹

Devices: ICDs

Patients with heart failure are at increased risk of sudden death and ventricular arrhythmias.³⁹ Previously, antiarrhythmic drugs were considered the standard of care for nonsustained ventricular tachycardia after myocardial infarction.

MADIT (the Multicenter Automatic Defibrillator Implantation Trial) investigated whether prophylactic implantation of an internal cardiac defibrillator would improve 5-year survival rates in patients with heart failure. Eligible patients had had a Q-wave or enzyme-positive myocardial infarction within 3 weeks of study entry. They also had had an episode of asymptomatic nonsustained ventricular tachycardia unrelated to an acute myocardial infarction. Additionally, the patients had a left ventricular ejection fraction less than 35%, and inducible, sustained, nonsuppressible ventricular tachyarrhythmia on electrophysiologic testing.⁴⁰

During the study, 15 patients in the defibrillator group died vs 39 in the conventional therapy group (P = .009).⁴⁰

MADIT II evaluated the potential survival benefit of a prophylactically implanted defibrillator in the absence of electrophysiologic testing to induce arrhythmias.⁴¹ MADIT II included 1,232 patients with prior myocardial infarctions and a left ventricular ejection fracton of 30% or less. Patients were randomized to receive an implanted cardioverter-defibrillator or conventional medical therapy. The primary end point was death from any cause.⁴¹

The mortality rate was 19.8% in the conventional therapy group vs 14.2% in the defibrillator group (hazard ratio 0.69, P = .016).⁴¹ Thus, MADIT-II confirmed the benefits of prophylactic implantable cardioverter-defibrillator therapy seen in the original MADIT, and additionally eliminated the need for an electrophysiology test prior to device implantation.

SCD-HeFT (the Sudden Cardiac Death in Heart Failure Trial) evaluated whether amiodarone or a conservatively programmed shock-only, single-lead implanted cardioverter-defibrillator would decrease the risk of death (all-cause) in a population with mild to moderate heart failure with ischemic and nonischemic causes.⁴² In this trial, 2,521 patients with an ejection fraction of 35% or less, in NYHA class II or III, and with stable heart failure were randomized to receive a single-chamber implantable cardioverter-defibrillator,  amiodarone, or placebo.

There were 244 deaths in the placebo group, 240 deaths in the amiodarone group (P = .53 compared with placebo), and 182 deaths in the defibrillator group (P = .007 compared with placebo).⁴²

Recommendations. The 2013 ACC/AHA guideline¹ gives implantable defibrillator therapy a class IA recommendation for the primary prevention of sudden cardiac death in selected patients with nonischemic cardiomyopathy or ischemic cardiomyopathy at least 40 days after a myocardial infarction and 90 days after percutaneous coronary intervention or coronary artery bypass grafting; with a left ventricular ejection fraction of 35% or less; and NYHA class II or III symptoms on chronic goal-directed medical management.

This therapy receives a class IB recommendation for primary prevention of sudden cardiac death to reduce total mortality in selected patients at least 40 days after myocardial infarction with a left ventricular ejection fraction of 30% or less and NYHA class I symptoms while receiving goal-directed medical therapy.

Implantable cardioverter-defibrillators are not recommended in patients who otherwise have a life expectancy of less than 1 year.

Devices: Cardiac resynchronization therapy

From 25% to 30% of heart failure patients have an intraventricular conduction abnormality,^43,44 which can result in abnormalities of systolic and diastolic function. Biventricular pacing, in which a pacing lead is placed in the coronary sinus in addition to the right atrium and right ventricle, optimizes synchronization of ventricular contraction.^43,44

MUSTIC (the Multisite Stimulation in Cardiomyopathies study) was a randomized trial designed to assess the efficacy of biventricular pacing (also known as cardiac resynchronization therapy) in heart failure patients.⁴⁴ Entry criteria included NYHA class III heart failure for at least 1 month, left ventricular ejection fraction less than 35%, left ventricular end-diastolic diameter greater than 60 mm, and QRS duration longer than 150 ms. Patients were followed up at 9 and 12 months with 6-minute walking distance, peak oxygen consumption, changes in NYHA class, and left ventricular systolic function by echocardiography or radionuclide testing. Quality of life was assessed by the Minnesota Living With Heart Failure Questionnaire.

At 12 months, patients could walk significantly farther in 6 minutes, and their peak oxygen consumption had increased. They also reported significant improvement in quality of life, and NYHA class improved by 25%. MUSTIC was the first study to show a benefit in exercise tolerance, quality of life, improvement in cardiac performance, and reduction in heart failure symptoms with the use of biventricular pacing at 1 year.

MIRACLE (the Multicenter InSync Randomized Clinical Evaluation) validated the findings seen in MUSTIC by using a larger population size and a double-blinded method.⁴⁵ Compared with a control group, patients who underwent cardiac resynchronization therapy could walk farther in 6 minutes and scored better in NYHA class, quality of life, and left ventricular ejection fraction.⁴⁵

Recommendations. The 2013 ACC/AHA guidelines¹ give cardiac resynchronization therapy a class IA/B indication for NYHA class II, III, or IV patients on goal-directed medical therapy in sinus rhythm with left ventricular ejection fraction 35% or less, left bundle branch block, and QRS duration of 150 ms or more.¹

Devices: Implantable sensors

The future of ambulatory heart failure management may include implantable pulmonary artery pressure sensors.

The CardioMEMS is a permanently implantable pressure measurement system designed to provide daily pulmonary artery pressure measurements in an ambulatory setting with a goal of reducing heart failure-related hospitalizations. Through a transvenous delivery system, an implantable, battery-free sensor is positioned in the distal pulmonary artery.^46,47

CHAMPION (the CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in NYHA Class III Patients trial) was one of the first major trials to assess the safety and efficacy of implantable pulmonary artery pressure monitoring systems.⁴⁶ The study device was associated with a significant reduction in mean pulmonary artery pressures, fewer heart failure hospitalizations, and better quality of life. The length of stay for heart failure-related hospitalizations was also significantly shorter in the CardioMEMs group.⁴⁶

Exercise

Patients with heart failure routinely experience a decline in functional capacity. This decline manifests as reduced exercise tolerance and poor quality of life, usually resulting in a physician recommendation to rest and paradoxical deconditioning and possible progression of symptoms.

Several studies have shown that cardiac rehabilitation has improved outcomes in heart failure patients.⁴⁸ Cardiac rehabilitation is a supervised program that helps patients with exercise training, healthy living, education, and psychosocial counseling.

HF-ACTION (Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training) is the largest randomized trial performed to determine whether aerobic exercise training reduces all-cause mortality or all-cause hospitalization and improves quality of life in patients with stable heart failure.⁴⁹ Although the reduction in end points was initially not statistically significant, after adjusting for highly prognostic predictors of poor outcomes (cardiopulmonary exercise time, left ventricular ejection fraction, atrial fibrillation, and depression), exercise training was found to reduce the incidence of all-cause mortality or all-cause hospitalization by 11% (P = .03).⁴⁹

Recommendations. Based on the results of HF-ACTION and several smaller studies, the ACC/AHA guidelines give exercise training a class IA recommendation as a safe and effective activity for patients with heart failure who are able to participate, to improve functional status.¹ A class IIA recommendation is given to cardiac rehabilitation for the improvement of functional capacity, exercise duration, quality of life, and mortality rates.¹

End-stage heart failure: Recognition

Despite adequate titration of goal-directed medical therapy, a portion of patients with heart failure with reduced ejection fraction ultimately progress to stage D, also termed “advanced” heart failure. The 5-year survival rate for patients with heart failure overall is 50%, but the 1-year mortality rate for those with advanced heart failure exceeds 50%.⁵⁰

Because the high rates of morbidity and mortality can potentially be lowered, recognition of heart failure disease progression is imperative so that patients can be promptly referred for therapies such as inotropic infusion, mechanical circulatory support, and cardiac transplant, as well as end-of-life care such as hospice.¹

The ACC/AHA¹ have published clinical events and findings useful in identifying patients with advanced heart failure:

• Two or more hospitalizations or emergency department visits for heart failure in the past year
• Progressive deterioration in renal function (eg, elevation in creatinine or blood urea nitrogen)
• Weight loss without other cause
• Intolerance to ACE inhibitors due to hypotension or worsening renal function
• Inability to tolerate beta-blockers due to worsening heart failure or hypotension
• Systolic blood pressure often below 90 mm Hg
• Persistent dyspnea with dressing or bathing requiring rest
• Inability to walk one block on level ground due to dyspnea or fatigue
• Recent need to escalate diuretics to maintain volume status, often reaching daily dose equivalent to furosemide more than 160 mg/day or use of supplemental metolazone
• Progressive decline in serum sodium, usually to below 133 mmol/L
• Frequent shocks from implanted cardiac defibrillator.

End-stage heart failure: Left ventricular assist devices

For patients with refractory heart failure despite optimal medical management, advanced therapies such as heart transplant or ventricular assist devices have been proven to be durable options. These mechanical circulatory support devices “unload” the diseased ventricle and maintain cardiac output to vital organs.⁵¹ They were initially designed as temporary support to allow ventricular recovery or as a bridge to cardiac transplant. However, they have also evolved into permanent (“destination”) therapy.⁵²

REMATCH (the Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive HF trial) was the landmark study that showed that left ventricular assist device implantation resulted in a survival benefit and an improved quality of life in patients with advanced heart failure ineligible for cardiac transplant, compared with medical management.⁵⁰ Implantation of a left ventricular assist device was associated with a 27% absolute reduction in the 1-year mortality rate.⁵⁰

Since the National Institutes of Health’s artificial heart program was launched in 1964, there has been tremendous progress in the development of mechanical circulatory devices.⁵⁰ The results of REMATCH were promising, but the 2-year survival rate was still only 23%, leaving a lot to be desired.

The HeartMate II (Thoratec) trial compared an axial continuous-flow device vs the previously established pulsatile left ventricular assist device, and noted a 2-year survival of 58% with the continuous flow device vs  24% with the pulsatile device (P = .008).⁵³

ADVANCE (Evaluation of the HeartWare Left Ventricular Assist Device for the Treatment of Advanced Heart Failure) showed similar efficacy of the HVAD (Heartware), a centrifugal continuous-flow LVAD currently in use.⁵⁴

The next generation of continuous-flow left ventricular assist devices are currently in clinical trials in the United States and include the axial flow MVAD (Heartware) and centrifugal flow Heartmate III (Thoratec).

We emphasize the importance of early identification of patients with advanced disease who may qualify for and benefit from such therapies.

The management of heart failure is evolving. In the 1960s, the standard heart failure medical regimen included digoxin, diuretics, and the recommendation of rest. This contrasts with the current era, in which medical regimens include neurohormonal blockade, diuretics, and the promotion of physical activity.⁵⁵ Since the publication of the 2013 heart failure guidelines, new medical and device options have emerged that have been proven to either improve survival or reduce hospitalizations. The development of clinical guidelines promotes evidence-based practice and overcomes the inertia of practice patterns based on anecdotal evidence.

Several approaches to the management of heart failure have been recommended. A major effort should be made to identify those at risk for heart failure (stage A) and to implement risk factor modification. Treatment of hypertension, diabetes mellitus, and dyslipidemia decreases the risk of heart failure.¹

For patients with evidence of structural heart disease with and without symptoms, Figure 1 summarizes a guideline approach to the management of heart failure. It should be stressed that guidelines are meant to guide management, but do not serve as a substitute for sound clinical judgment.

Heart failure is the common final pathway of all cardiac pathology, and understanding the neurohormonal response and maladaptive physiology has led to the development of novel therapeutics and devices. At present, the field of cardiology may not be able to remove the “failure” from heart failure, but we can make every effort to prevent failure of treatment delivery and reduce resource utilization and morbidity associated with this syndrome.

Acknowledgments: We would like to thank Chankya Dahagam and Cynthia Obenwa for their valuable contribution in the preparation of this manuscript.

Managing heart failure is a challenge. To aid clinicians in this task, the American College of Cardiology Foundation (ACC) and the American Heart Association (AHA) publish evidence-based guidelines, most recently in 2013.¹ Since then, new drugs and devices have been shown to improve survival and reduce hospitalizations.

See related editorial

This paper reviews the ABCs of outpatient management of systolic heart failure (or heart failure with reduced ejection fraction), including the results of major trials and recommendations.

A common and serious condition

Heart failure is a debilitating syndrome that takes a significant physical and mental toll on those affected.

And it is common. An American age 40 or older faces a 20% lifetime risk of heart failure.¹ An estimated 5.1 million Americans have clinical signs and symptoms of heart failure, and 900,000 new cases are diagnosed each year.² By 2030 the prevalence of heart failure is projected to increase by 46%, and 9 million Americans will have been diagnosed with it.²

The severity of heart failure can be described using either the functional classification devised by the New York Heart Association (NYHA; Table 1) or the stages defined by the ACC and AHA.^1,3 Though survival rates have improved, there is a direct correlation between worsening symptoms and death.⁴

Heart failure is the leading cause of hospitalizations annually. It accounts for $30 billion in healthcare costs, with direct medical costs accounting for 68% and another $1.8 billion associated with clinic visits, most often with primary care providers. By 2030, the cost is projected to increase by 127% to $69.7 billion—$244 per person in the United States.²

ACE inhibitors

The renin-angiotensin-aldosterone system has been studied for over 100 years.⁵

In heart failure with reduced ejection fraction, this system is upregulated as an adaptive mechanism to maintain hemodynamic homeostasis.^6–8 However, prolonged activation of the renin-angiotensin-aldosterone system can lead to deleterious cardiovascular effects such as myocyte hypertrophy, myocardial fibrosis, sodium conservation, and fluid overload.^8,9 Angiotensin II is a potent vasoconstrictor and plays a role in cardiovascular remodeling, leading to worsening progression of heart failure.⁶

CONSENSUS (the Cooperative North Scandinavian Enalapril Survival Study) examined the effect of the angiotensin-converting enzyme (ACE) inhibitor enalapril on survival in 253 patients with NYHA class IV heart failure. Participants were randomized to receive either enalapril or placebo. At 6 months, the mortality rate was 26% in the enalapril group vs 44% in the placebo group, an 18% absolute risk reduction and a 41% relative risk reduction (P = .002). At 12 months, the relative risk reduction in mortality was 30% (P = .001).¹⁰

SOLVD (the Study of Left Ventricular Dysfunction) extended the use of ACE inhibitors to all patients with heart failure, not just those in NYHA class IV. It randomized 1,284 patients with heart failure of any NYHA class and an ejection fraction less than 35% to receive either enalapril or placebo, and demonstrated a 16% relative risk reduction in mortality in the enalapril group, with mortality rates of 36% vs 39.7% (P = .0036).¹¹

Recommendations. The benefits of ACE inhibition have been demonstrated in patients with mild, moderate, and severe heart failure. Thus, the guidelines recommend ACE inhibitors (Table 2) for all patients with heart failure with reduced ejection fraction.¹

Angiotensin II receptor blockers

Angiotensin II receptor blockers (ARBs) (Table 3) have been proven to be suitable alternatives for patients with heart failure with reduced ejection fraction who cannot tolerate ACE inhibitors.

Val-HefT (the Valsartan HF Trial)¹² randomized 5,010 patients in a double-blind fashion to receive either valsartan or placebo, with background therapy that included beta-blockers, digoxin, diuretics, and ACE inhibitors. There was a 13% reduction of the combined primary end point of mortality and morbidity and a 24% reduction in heart failure hospitalizations in the valsartan group.¹²

Subgroup analysis compared patients on the basis of use of ACE inhibitors and beta-blockers at study entry. Valsartan had a favorable effect in the subgroups using beta-blockers alone, ACE inhibitors alone, and neither drug. However, when patients received all three (a beta-blocker, an ACE inhibitor, and valsartan), the mortality rate was significantly increased (P = .009).¹² This finding conflicted with those of other studies, which found a small benefit of combining an ACE inhibitor and an ARB.

CHARM-Added (the Candesartan in HF Assessment of Reduction in Mortality and Morbidity trial)¹³ investigated whether adding the ARB candesartan to an ACE inhibitor would improve clinical outcomes. In the study, 2,548 patients in NYHA class II, III, or IV with a left ventricular ejection fraction of less than 40% who were receiving ACE inhibitors were randomized to either candesartan or placebo. The addition of candesartan resulted in a significant reduction in cardiovascular mortality and heart failure hospitalizations, but with the downside of higher rates of hyperkalemia and serum creatinine elevation.¹³

Recommendations. The 2013 guidelines recommend that ARBs be used in patients who cannot tolerate an ACE inhibitor due to cough. However, routine combined use of ARBs, ACE inhibitors, and aldosterone antagonists is not recommended and may cause harm.¹

Aldosterone receptor antagonists

Elevated levels of aldosterone lead to fluid retention, loss of magnesium and potassium, and myocardial fibrosis.

RALES (the Randomized Aldactone Evaluation Study)¹⁴ tested the hypothesis that the aldosterone receptor antagonist spironolactone (25 mg daily) would reduce deaths from all causes in patients with severe heart failure receiving standard medications including an ACE inhibitor. RALES included 1,663 patients in NYHA class III or IV with a left ventricular ejection fraction of 35% or less, randomized to receive 25 mg of spironolactone or matching placebo. This study found a 30% relative risk reduction and an 11% absolute risk reduction in all-cause mortality, a 31% relative risk reduction and a 10% absolute risk reduction in cardiac mortality, and 30% fewer cardiac-related hospitalizations in the spironolactone group.¹⁴

Eplerenone, an aldosterone receptor antagonist that lacks the antiandrogenic side effects of spironolactone, has also been shown to be beneficial. Its efficacy in patients with left ventricular systolic dysfunction was first established in postmyocardial infarction patients.¹⁵

EMPHASIS-HF (the Eplerenone in Mild Patients Hospitalized and Survival Study in Heart Failure)¹⁶ broadened the application of eplerenone (and aldosterone antagonists in general), investigating the effects of eplerenone in 2,737 NYHA class II patients, regardless of ischemic etiology. The composite end point of cardiovascular death or heart failure hospitalization occurred in 18.3% of the eplerenone group vs 25.9% of the placebo group (P < .001). A total of 12.5% of patients in the eplerenone group died, compared with 15.5% in the placebo group (P = .008). Hospitalizations were also fewer in the eplerenone group.

Recommendations. The 2013 guidelines recommend aldosterone receptor antagonists (Table 4) for patients with NYHA class II, III, or IV heart failure who have an ejection fraction of 35% or less, to reduce morbidity and mortality (class IA recommendation).¹ The guidelines also recommend that these agents not be used in patients with renal insufficiency (serum creatinine > 2.5 mg/dL in men or > 2.0 mg/dL in women; an estimated glomerular filtration rate < 30 mL/min/1.73 m²); or a serum potassium level above 5 mmol/L.¹

Angiotensin-neprilysin inhibitor (the future)

Research has identified neprilysin as another potential target in the treatment of heart failure and has sought to combine inhibition of angiotensin and neprilysin.

Neprilysin, a neutral endopeptidase, is associated with degradation of several natural vasoactive peptides such as natriuretic peptide, bradykinin, and adrenomedullin. Neprilysin inhibition increases these substances and counters the neurohormonal overactivation that leads to vasoconstriction, sodium retention, and cardiac remodeling.¹⁷

The ARB valsartan has been combined with the neprilysin inhibitor sacubitril to create the first angiotensin-neprilysin inhibitor (ARNI) (Table 5). The combination was selected to minimize the potential for angioedema.

PARADIGM-HF (the Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure trial)¹⁷ examined whether combined angiotensin-neprilysin inhibition was superior to ACE inhibition alone with enalapril in patients with chronic heart failure.

In PARADIGM-HF, 10,521 patients with NYHA class II, III, or IV heart failure were randomized to receive either sacubitril-valsartan or enalapril. The group receiving sacubitril-valsartan had significantly fewer deaths from cardiovascular causes and heart failure hospitalizations.¹⁷ An improvement in quality of life and NYHA functional class was also observed in the sacubitril-valsartan group.¹⁷

Sacubitril-valsartan underwent priority review by the US Food and Drug Administration and has been approved. Currently, it is indicated for the treatment of heart failure with reduced ejection fraction and NYHA class II, III, or IV symptoms. It should be avoided in patients who have previously experienced angioedema with an ACE inhibitor or ARB, in patients receiving aliskiren for diabetes, and in patients with hypersensitivity reactions to either of its components. Simultaneous use of sacubitril-valsartan and an ACE inhibitor should be avoided, and a washout period is recommended when transitioning from an ACE inhibitor to this combined agent.

Beta-blockers

In heart failure, there is increased sympathetic activation and associated elevations in norepinephrine levels, which may lead to deleterious long-term effects on cardiac function and structure. Beta-adrenergic receptor blockade is now known to be cardioprotective, but it was not always so; beta-blockers used to be contraindicated in patients with heart failure.

An early experience using beta-blockers in heart failure was described in 1975.^18,19 The first study to report a survival benefit of treating systolic heart failure with a beta-blocker was published in 1979.²⁰ Later, small controlled trials demonstrated a reduction in heart failure symptoms and improvement in left ventricular function and in NYHA functional class.²¹ Larger clinical trials have demonstrated a tremendous survival benefit with beta-blockers in heart failure, specifically carvedilol, extended-release metoprolol, and bisoprolol.

The US Carvedilol Heart Failure Study Group trial²² evaluated whether beta-blocker use in heart failure patients would reduce the rates of morbidity and mortality.²² The trial included 1,094 patients with symptomatic heart failure for at least 3 months and a left ventricular ejection fraction of 35% or less on background therapy including vasodilators, ACE inhibitors, and digoxin. Patients were randomized to receive either carvedilol or placebo. Carvedilol use was associated with a dramatic 65% risk reduction in mortality (7.8% with placebo vs 3.2% with carvedilol, P < .001) and a 27% risk reduction in hospitalizations (19.6% vs 14.1%, P = .036), leading to early trial termination.

CIBIS-II (the Cardiac Insufficiency Bisoprolol Study II)²³ investigated the effects of beta-blockers on survival and morbidity. CIBIS-II included 2,647 NYHA class III or IV patients with a left ventricular ejection fraction less than 35% on background medical therapy that included diuretics and ACE inhibitors. This trial was also terminated early, after demonstrating a significant survival benefit with bisoprolol.

MERIT-HF (the Metoprolol Extended Release Randomized Intervention Trial in Congestive Heart Failure)²⁴ evaluated if once-daily metoprolol would lower mortality rates  in patients with symptomatic heart failure. The study enrolled 3,991 NYHA class II–IV patients with chronic heart failure and a left ventricular ejection fraction of 40% or less. Like the previous two beta-blocker trials, MERIT-HF was terminated early, as it demonstrated a 34% reduction in all-cause mortality (7.2% risk of death per patient-year vs 11.0%, P = .00009).

The beta-blocker trials have shown that when added to background therapy, beta-blockers improve survival and reduce hospitalizations. However, when prescribing a beta-blocker, it is important to understand that not all beta-blockers are equal in the treatment of heart failure.

COMET (the Carvedilol or Metoprolol European Trial)²⁵ was the only head-to-head randomized control trial evaluating clinical outcomes in patients receiving carvedilol or metoprolol tartrate (not metoprolol succinate). In COMET, 1,511 patients with NYHA class II, III, or IV heart failure with a left ventricular ejection fraction of 35% or less were randomized to carvedilol or metoprolol tartrate. The primary end point of all-cause mortality occurred in 34% of the carvedilol group and 40% of the metoprolol tartrate group (P = .0017). There was no significant difference with regard to the composite end point of mortality and all-cause admissions.

Recommendations. The 2013 guidelines give a class IA recommendation for starting a beta-blocker (carvedilol, bisoprolol, or metoprolol succinate, Table 6) in patients with current or prior symptoms of heart failure.¹ Beta-blockers should be initiated with caution or avoided in patients with acutely decompensated heart failure with evidence of fluid overload.

Brain-type natriuretic peptide

Brain-type natriuretic peptide (BNP) or its amino-terminal cleavage product (NT-proBNP) originates in cardiomyocytes and is released by several triggers, most commonly cardiomyocyte stretch in the setting of volume or pressure overload.²⁶ The biologic significance of BNP includes natriuresis and vasodilation, renin-angiotensin system inhibition, and sympathetic nervous system modulation.²⁶

TIME-CHF (the Trial of Intensified vs. Standard Medical Therapy in Elderly Patients With Congestive HF)²⁷ investigated whether 18-month outcomes would be better if treatment were guided by N-terminal BNP levels rather than by symptoms. The BNP-guided strategy was not associated with a reduction in hospitalization or a survival benefit.

BATTLESCARRED (the NT-proBNP-Assisted Treatment to Lessen Serial Cardiac Readmissions and Death trial)²⁸ in 2009 showed that a BNP-guided management strategy significantly reduced mortality rates in patients under age 75 compared with standard medical therapy.

PROTECT (the Use of NT-proBNP Testing to Guide HF Therapy in the Outpatient Setting study)²⁹ also showed that a BNP-guided strategy was superior to usual care and was associated with reduced cardiovascular events and improved quality of life.²⁹

GUIDE IT-HF (the Guiding Evidence Based Therapy Using Biomarker Intensified Treatment in Heart Failure study), currently ongoing, is designed to assess the safety, efficacy and cost-effectiveness of a biomarker-guided strategy in 1,100 high-risk patients with heart failure with reduced ejection fraction. 

Recommendations. The 2013 ACC/AHA guidelines give a class IA recommendation for the use of BNP to support clinical decision-making, particularly in cases of clinical uncertainty.¹ BNP can also be used to establish prognosis or disease severity in chronic heart failure and to achieve optimal dosage of goal-directed medical therapy for euvolemic patients followed in a structured heart failure program.¹

Heart failure clinics

Continuity of care upon discharge from the hospital is currently in a state of evolution. Those diagnosed with heart failure can now experience more comprehensive posthospital care by virtue of disease management clinics. The name may vary by institution, but whether it is called a “diuresis clinic,” “bridge clinic,” or “heart failure clinic,” the goal is to improve guideline-driven care, educate the patient, and reduce heart failure hospitalizations. Heart failure clinics are designed to provide a smooth transition from inpatient to outpatient care and to encourage patient self-accountability in health maintenance thereafter.

Studies have shown that heart failure clinics are associated with better medication dosing, fewer hospitalizations, and lower healthcare costs.^30–32

Chronotropy: I_f inhibition

An elevated resting heart rate has been shown to be associated with increased cardiovascular morbidity and mortality.³³ Studies have shown that slowing the heart rate improves myocardial contraction and energy supply and reduces energy expenditure.³⁴ Ivabradine, a selective I_f (the f is for “funny”) channel inhibitor, slows the heart rate without other known cardiovascular effects.

SHIFT (the Systolic Heart Failure Treatment With the I_f Inhibitor Ivabradine Trial)³⁵ investigated whether isolated heart rate reduction with ivabradine would reduce adverse clinical outcomes in patients with symptomatic heart failure. SHIFT randomized 6,505 patients with a left ventricular ejection fraction of 35% or less, in sinus rhythm, with a heart rate of at least 70 beats per minute, on optimal medical therapy, and hospitalized within 12 months of enrollment to receive ivabradine or placebo. The primary end point was a composite of cardiovascular mortality and hospital admission for worsening heart failure. Outcomes varied by heart rates achieved, with the best outcomes in those with the lowest heart rates at trial conclusion.

Ivabradine (Table 7) is indicated for patients with symptomatic heart failure with a left ventricular ejection fraction less than 35%, in sinus rhythm, with a resting heart rate of at least 70 beats per minute, and either on a maximally tolerated beta-blocker or with a contraindication to beta-blockers.

Ivabradine should be avoided in patients who are in acute decompensated heart failure or are hypotensive (blood pressure < 90/50 mm Hg), as well as in patients with a significant conduction abnormality (sick sinus syndrome, sinoatrial block, third-degree atrioventricular block), hepatic impairment, or bradycardia (resting heart rate < 60 beats per minute).

Digoxin

Digoxin has been used in treating systolic heart failure for more than 70 years.^36,37

DIG (Digoxin Investigative Group trial)³⁸ evaluated the long-term effect of digoxin on rates of mortality and hospitalization for heart failure over a 3-year period. In patients with  a left ventricular ejection fraction less than 45%, digoxin had no effect on overall mortality when combined with diuretics and ACE inhibitors. However, the risk of hospitalization for worsening heart failure was significantly reduced with digoxin treatment.³⁸

Recommendations. Digoxin should be considered when patients are on guideline-recommended therapy but heart failure symptoms persist. It is commonly initiated at a dose of 0.125 to 0.25 mg. The target therapeutic range for digoxin is 0.5 to 0.9 ng/mL.¹ Digoxin toxicity can occur in patients with renal impairment, hypokalemia, hypomagnesemia, and hypothyroidism.

The 2013 ACC/AHA guidelines give a class IIA recommendation (treatment is “reasonable”) for digoxin in patients with heart failure with reduced ejection fraction unless contraindicated, to decrease hospitalizations for heart failure.¹

Diuretics

Clinical manifestations of volume overload in patients with heart failure are from excess salt and water retention leading to inappropriate volume expansion in both the vascular and extravascular space. Diuretics (Table 8) are the foundation of heart failure treatment. Most patients are first initiated on a combination of a loop diuretic and a low-sodium diet to improve symptoms.

The 2013 ACC/AHA guidelines give a class I recommendation for diuretics in patients with heart failure with reduced ejection fraction who have evidence of fluid retention, unless contraindicated, to improve symptoms.¹

Devices: ICDs

Patients with heart failure are at increased risk of sudden death and ventricular arrhythmias.³⁹ Previously, antiarrhythmic drugs were considered the standard of care for nonsustained ventricular tachycardia after myocardial infarction.

MADIT (the Multicenter Automatic Defibrillator Implantation Trial) investigated whether prophylactic implantation of an internal cardiac defibrillator would improve 5-year survival rates in patients with heart failure. Eligible patients had had a Q-wave or enzyme-positive myocardial infarction within 3 weeks of study entry. They also had had an episode of asymptomatic nonsustained ventricular tachycardia unrelated to an acute myocardial infarction. Additionally, the patients had a left ventricular ejection fraction less than 35%, and inducible, sustained, nonsuppressible ventricular tachyarrhythmia on electrophysiologic testing.⁴⁰

During the study, 15 patients in the defibrillator group died vs 39 in the conventional therapy group (P = .009).⁴⁰

MADIT II evaluated the potential survival benefit of a prophylactically implanted defibrillator in the absence of electrophysiologic testing to induce arrhythmias.⁴¹ MADIT II included 1,232 patients with prior myocardial infarctions and a left ventricular ejection fracton of 30% or less. Patients were randomized to receive an implanted cardioverter-defibrillator or conventional medical therapy. The primary end point was death from any cause.⁴¹

The mortality rate was 19.8% in the conventional therapy group vs 14.2% in the defibrillator group (hazard ratio 0.69, P = .016).⁴¹ Thus, MADIT-II confirmed the benefits of prophylactic implantable cardioverter-defibrillator therapy seen in the original MADIT, and additionally eliminated the need for an electrophysiology test prior to device implantation.

SCD-HeFT (the Sudden Cardiac Death in Heart Failure Trial) evaluated whether amiodarone or a conservatively programmed shock-only, single-lead implanted cardioverter-defibrillator would decrease the risk of death (all-cause) in a population with mild to moderate heart failure with ischemic and nonischemic causes.⁴² In this trial, 2,521 patients with an ejection fraction of 35% or less, in NYHA class II or III, and with stable heart failure were randomized to receive a single-chamber implantable cardioverter-defibrillator,  amiodarone, or placebo.

There were 244 deaths in the placebo group, 240 deaths in the amiodarone group (P = .53 compared with placebo), and 182 deaths in the defibrillator group (P = .007 compared with placebo).⁴²

Recommendations. The 2013 ACC/AHA guideline¹ gives implantable defibrillator therapy a class IA recommendation for the primary prevention of sudden cardiac death in selected patients with nonischemic cardiomyopathy or ischemic cardiomyopathy at least 40 days after a myocardial infarction and 90 days after percutaneous coronary intervention or coronary artery bypass grafting; with a left ventricular ejection fraction of 35% or less; and NYHA class II or III symptoms on chronic goal-directed medical management.

This therapy receives a class IB recommendation for primary prevention of sudden cardiac death to reduce total mortality in selected patients at least 40 days after myocardial infarction with a left ventricular ejection fraction of 30% or less and NYHA class I symptoms while receiving goal-directed medical therapy.

Implantable cardioverter-defibrillators are not recommended in patients who otherwise have a life expectancy of less than 1 year.

Devices: Cardiac resynchronization therapy

From 25% to 30% of heart failure patients have an intraventricular conduction abnormality,^43,44 which can result in abnormalities of systolic and diastolic function. Biventricular pacing, in which a pacing lead is placed in the coronary sinus in addition to the right atrium and right ventricle, optimizes synchronization of ventricular contraction.^43,44

MUSTIC (the Multisite Stimulation in Cardiomyopathies study) was a randomized trial designed to assess the efficacy of biventricular pacing (also known as cardiac resynchronization therapy) in heart failure patients.⁴⁴ Entry criteria included NYHA class III heart failure for at least 1 month, left ventricular ejection fraction less than 35%, left ventricular end-diastolic diameter greater than 60 mm, and QRS duration longer than 150 ms. Patients were followed up at 9 and 12 months with 6-minute walking distance, peak oxygen consumption, changes in NYHA class, and left ventricular systolic function by echocardiography or radionuclide testing. Quality of life was assessed by the Minnesota Living With Heart Failure Questionnaire.

At 12 months, patients could walk significantly farther in 6 minutes, and their peak oxygen consumption had increased. They also reported significant improvement in quality of life, and NYHA class improved by 25%. MUSTIC was the first study to show a benefit in exercise tolerance, quality of life, improvement in cardiac performance, and reduction in heart failure symptoms with the use of biventricular pacing at 1 year.

MIRACLE (the Multicenter InSync Randomized Clinical Evaluation) validated the findings seen in MUSTIC by using a larger population size and a double-blinded method.⁴⁵ Compared with a control group, patients who underwent cardiac resynchronization therapy could walk farther in 6 minutes and scored better in NYHA class, quality of life, and left ventricular ejection fraction.⁴⁵

Recommendations. The 2013 ACC/AHA guidelines¹ give cardiac resynchronization therapy a class IA/B indication for NYHA class II, III, or IV patients on goal-directed medical therapy in sinus rhythm with left ventricular ejection fraction 35% or less, left bundle branch block, and QRS duration of 150 ms or more.¹

Devices: Implantable sensors

The future of ambulatory heart failure management may include implantable pulmonary artery pressure sensors.

The CardioMEMS is a permanently implantable pressure measurement system designed to provide daily pulmonary artery pressure measurements in an ambulatory setting with a goal of reducing heart failure-related hospitalizations. Through a transvenous delivery system, an implantable, battery-free sensor is positioned in the distal pulmonary artery.^46,47

CHAMPION (the CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in NYHA Class III Patients trial) was one of the first major trials to assess the safety and efficacy of implantable pulmonary artery pressure monitoring systems.⁴⁶ The study device was associated with a significant reduction in mean pulmonary artery pressures, fewer heart failure hospitalizations, and better quality of life. The length of stay for heart failure-related hospitalizations was also significantly shorter in the CardioMEMs group.⁴⁶

Exercise

Patients with heart failure routinely experience a decline in functional capacity. This decline manifests as reduced exercise tolerance and poor quality of life, usually resulting in a physician recommendation to rest and paradoxical deconditioning and possible progression of symptoms.

Several studies have shown that cardiac rehabilitation has improved outcomes in heart failure patients.⁴⁸ Cardiac rehabilitation is a supervised program that helps patients with exercise training, healthy living, education, and psychosocial counseling.

HF-ACTION (Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training) is the largest randomized trial performed to determine whether aerobic exercise training reduces all-cause mortality or all-cause hospitalization and improves quality of life in patients with stable heart failure.⁴⁹ Although the reduction in end points was initially not statistically significant, after adjusting for highly prognostic predictors of poor outcomes (cardiopulmonary exercise time, left ventricular ejection fraction, atrial fibrillation, and depression), exercise training was found to reduce the incidence of all-cause mortality or all-cause hospitalization by 11% (P = .03).⁴⁹

Recommendations. Based on the results of HF-ACTION and several smaller studies, the ACC/AHA guidelines give exercise training a class IA recommendation as a safe and effective activity for patients with heart failure who are able to participate, to improve functional status.¹ A class IIA recommendation is given to cardiac rehabilitation for the improvement of functional capacity, exercise duration, quality of life, and mortality rates.¹

End-stage heart failure: Recognition

Despite adequate titration of goal-directed medical therapy, a portion of patients with heart failure with reduced ejection fraction ultimately progress to stage D, also termed “advanced” heart failure. The 5-year survival rate for patients with heart failure overall is 50%, but the 1-year mortality rate for those with advanced heart failure exceeds 50%.⁵⁰

Because the high rates of morbidity and mortality can potentially be lowered, recognition of heart failure disease progression is imperative so that patients can be promptly referred for therapies such as inotropic infusion, mechanical circulatory support, and cardiac transplant, as well as end-of-life care such as hospice.¹

The ACC/AHA¹ have published clinical events and findings useful in identifying patients with advanced heart failure:

• Two or more hospitalizations or emergency department visits for heart failure in the past year
• Progressive deterioration in renal function (eg, elevation in creatinine or blood urea nitrogen)
• Weight loss without other cause
• Intolerance to ACE inhibitors due to hypotension or worsening renal function
• Inability to tolerate beta-blockers due to worsening heart failure or hypotension
• Systolic blood pressure often below 90 mm Hg
• Persistent dyspnea with dressing or bathing requiring rest
• Inability to walk one block on level ground due to dyspnea or fatigue
• Recent need to escalate diuretics to maintain volume status, often reaching daily dose equivalent to furosemide more than 160 mg/day or use of supplemental metolazone
• Progressive decline in serum sodium, usually to below 133 mmol/L
• Frequent shocks from implanted cardiac defibrillator.

End-stage heart failure: Left ventricular assist devices

For patients with refractory heart failure despite optimal medical management, advanced therapies such as heart transplant or ventricular assist devices have been proven to be durable options. These mechanical circulatory support devices “unload” the diseased ventricle and maintain cardiac output to vital organs.⁵¹ They were initially designed as temporary support to allow ventricular recovery or as a bridge to cardiac transplant. However, they have also evolved into permanent (“destination”) therapy.⁵²

REMATCH (the Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive HF trial) was the landmark study that showed that left ventricular assist device implantation resulted in a survival benefit and an improved quality of life in patients with advanced heart failure ineligible for cardiac transplant, compared with medical management.⁵⁰ Implantation of a left ventricular assist device was associated with a 27% absolute reduction in the 1-year mortality rate.⁵⁰

Since the National Institutes of Health’s artificial heart program was launched in 1964, there has been tremendous progress in the development of mechanical circulatory devices.⁵⁰ The results of REMATCH were promising, but the 2-year survival rate was still only 23%, leaving a lot to be desired.

The HeartMate II (Thoratec) trial compared an axial continuous-flow device vs the previously established pulsatile left ventricular assist device, and noted a 2-year survival of 58% with the continuous flow device vs  24% with the pulsatile device (P = .008).⁵³

ADVANCE (Evaluation of the HeartWare Left Ventricular Assist Device for the Treatment of Advanced Heart Failure) showed similar efficacy of the HVAD (Heartware), a centrifugal continuous-flow LVAD currently in use.⁵⁴

The next generation of continuous-flow left ventricular assist devices are currently in clinical trials in the United States and include the axial flow MVAD (Heartware) and centrifugal flow Heartmate III (Thoratec).

We emphasize the importance of early identification of patients with advanced disease who may qualify for and benefit from such therapies.

The management of heart failure is evolving. In the 1960s, the standard heart failure medical regimen included digoxin, diuretics, and the recommendation of rest. This contrasts with the current era, in which medical regimens include neurohormonal blockade, diuretics, and the promotion of physical activity.⁵⁵ Since the publication of the 2013 heart failure guidelines, new medical and device options have emerged that have been proven to either improve survival or reduce hospitalizations. The development of clinical guidelines promotes evidence-based practice and overcomes the inertia of practice patterns based on anecdotal evidence.

Several approaches to the management of heart failure have been recommended. A major effort should be made to identify those at risk for heart failure (stage A) and to implement risk factor modification. Treatment of hypertension, diabetes mellitus, and dyslipidemia decreases the risk of heart failure.¹

For patients with evidence of structural heart disease with and without symptoms, Figure 1 summarizes a guideline approach to the management of heart failure. It should be stressed that guidelines are meant to guide management, but do not serve as a substitute for sound clinical judgment.

Heart failure is the common final pathway of all cardiac pathology, and understanding the neurohormonal response and maladaptive physiology has led to the development of novel therapeutics and devices. At present, the field of cardiology may not be able to remove the “failure” from heart failure, but we can make every effort to prevent failure of treatment delivery and reduce resource utilization and morbidity associated with this syndrome.

Acknowledgments: We would like to thank Chankya Dahagam and Cynthia Obenwa for their valuable contribution in the preparation of this manuscript.

Managing heart failure is a challenge. To aid clinicians in this task, the American College of Cardiology Foundation (ACC) and the American Heart Association (AHA) publish evidence-based guidelines, most recently in 2013.¹ Since then, new drugs and devices have been shown to improve survival and reduce hospitalizations.

See related editorial

This paper reviews the ABCs of outpatient management of systolic heart failure (or heart failure with reduced ejection fraction), including the results of major trials and recommendations.

A common and serious condition

Heart failure is a debilitating syndrome that takes a significant physical and mental toll on those affected.

And it is common. An American age 40 or older faces a 20% lifetime risk of heart failure.¹ An estimated 5.1 million Americans have clinical signs and symptoms of heart failure, and 900,000 new cases are diagnosed each year.² By 2030 the prevalence of heart failure is projected to increase by 46%, and 9 million Americans will have been diagnosed with it.²

The severity of heart failure can be described using either the functional classification devised by the New York Heart Association (NYHA; Table 1) or the stages defined by the ACC and AHA.^1,3 Though survival rates have improved, there is a direct correlation between worsening symptoms and death.⁴

Heart failure is the leading cause of hospitalizations annually. It accounts for $30 billion in healthcare costs, with direct medical costs accounting for 68% and another $1.8 billion associated with clinic visits, most often with primary care providers. By 2030, the cost is projected to increase by 127% to $69.7 billion—$244 per person in the United States.²

ACE inhibitors

The renin-angiotensin-aldosterone system has been studied for over 100 years.⁵

In heart failure with reduced ejection fraction, this system is upregulated as an adaptive mechanism to maintain hemodynamic homeostasis.^6–8 However, prolonged activation of the renin-angiotensin-aldosterone system can lead to deleterious cardiovascular effects such as myocyte hypertrophy, myocardial fibrosis, sodium conservation, and fluid overload.^8,9 Angiotensin II is a potent vasoconstrictor and plays a role in cardiovascular remodeling, leading to worsening progression of heart failure.⁶

CONSENSUS (the Cooperative North Scandinavian Enalapril Survival Study) examined the effect of the angiotensin-converting enzyme (ACE) inhibitor enalapril on survival in 253 patients with NYHA class IV heart failure. Participants were randomized to receive either enalapril or placebo. At 6 months, the mortality rate was 26% in the enalapril group vs 44% in the placebo group, an 18% absolute risk reduction and a 41% relative risk reduction (P = .002). At 12 months, the relative risk reduction in mortality was 30% (P = .001).¹⁰

SOLVD (the Study of Left Ventricular Dysfunction) extended the use of ACE inhibitors to all patients with heart failure, not just those in NYHA class IV. It randomized 1,284 patients with heart failure of any NYHA class and an ejection fraction less than 35% to receive either enalapril or placebo, and demonstrated a 16% relative risk reduction in mortality in the enalapril group, with mortality rates of 36% vs 39.7% (P = .0036).¹¹

Recommendations. The benefits of ACE inhibition have been demonstrated in patients with mild, moderate, and severe heart failure. Thus, the guidelines recommend ACE inhibitors (Table 2) for all patients with heart failure with reduced ejection fraction.¹

Angiotensin II receptor blockers

Angiotensin II receptor blockers (ARBs) (Table 3) have been proven to be suitable alternatives for patients with heart failure with reduced ejection fraction who cannot tolerate ACE inhibitors.

Val-HefT (the Valsartan HF Trial)¹² randomized 5,010 patients in a double-blind fashion to receive either valsartan or placebo, with background therapy that included beta-blockers, digoxin, diuretics, and ACE inhibitors. There was a 13% reduction of the combined primary end point of mortality and morbidity and a 24% reduction in heart failure hospitalizations in the valsartan group.¹²

Subgroup analysis compared patients on the basis of use of ACE inhibitors and beta-blockers at study entry. Valsartan had a favorable effect in the subgroups using beta-blockers alone, ACE inhibitors alone, and neither drug. However, when patients received all three (a beta-blocker, an ACE inhibitor, and valsartan), the mortality rate was significantly increased (P = .009).¹² This finding conflicted with those of other studies, which found a small benefit of combining an ACE inhibitor and an ARB.

CHARM-Added (the Candesartan in HF Assessment of Reduction in Mortality and Morbidity trial)¹³ investigated whether adding the ARB candesartan to an ACE inhibitor would improve clinical outcomes. In the study, 2,548 patients in NYHA class II, III, or IV with a left ventricular ejection fraction of less than 40% who were receiving ACE inhibitors were randomized to either candesartan or placebo. The addition of candesartan resulted in a significant reduction in cardiovascular mortality and heart failure hospitalizations, but with the downside of higher rates of hyperkalemia and serum creatinine elevation.¹³

Recommendations. The 2013 guidelines recommend that ARBs be used in patients who cannot tolerate an ACE inhibitor due to cough. However, routine combined use of ARBs, ACE inhibitors, and aldosterone antagonists is not recommended and may cause harm.¹

Aldosterone receptor antagonists

Elevated levels of aldosterone lead to fluid retention, loss of magnesium and potassium, and myocardial fibrosis.

RALES (the Randomized Aldactone Evaluation Study)¹⁴ tested the hypothesis that the aldosterone receptor antagonist spironolactone (25 mg daily) would reduce deaths from all causes in patients with severe heart failure receiving standard medications including an ACE inhibitor. RALES included 1,663 patients in NYHA class III or IV with a left ventricular ejection fraction of 35% or less, randomized to receive 25 mg of spironolactone or matching placebo. This study found a 30% relative risk reduction and an 11% absolute risk reduction in all-cause mortality, a 31% relative risk reduction and a 10% absolute risk reduction in cardiac mortality, and 30% fewer cardiac-related hospitalizations in the spironolactone group.¹⁴

Eplerenone, an aldosterone receptor antagonist that lacks the antiandrogenic side effects of spironolactone, has also been shown to be beneficial. Its efficacy in patients with left ventricular systolic dysfunction was first established in postmyocardial infarction patients.¹⁵

EMPHASIS-HF (the Eplerenone in Mild Patients Hospitalized and Survival Study in Heart Failure)¹⁶ broadened the application of eplerenone (and aldosterone antagonists in general), investigating the effects of eplerenone in 2,737 NYHA class II patients, regardless of ischemic etiology. The composite end point of cardiovascular death or heart failure hospitalization occurred in 18.3% of the eplerenone group vs 25.9% of the placebo group (P < .001). A total of 12.5% of patients in the eplerenone group died, compared with 15.5% in the placebo group (P = .008). Hospitalizations were also fewer in the eplerenone group.

Recommendations. The 2013 guidelines recommend aldosterone receptor antagonists (Table 4) for patients with NYHA class II, III, or IV heart failure who have an ejection fraction of 35% or less, to reduce morbidity and mortality (class IA recommendation).¹ The guidelines also recommend that these agents not be used in patients with renal insufficiency (serum creatinine > 2.5 mg/dL in men or > 2.0 mg/dL in women; an estimated glomerular filtration rate < 30 mL/min/1.73 m²); or a serum potassium level above 5 mmol/L.¹

Angiotensin-neprilysin inhibitor (the future)

Research has identified neprilysin as another potential target in the treatment of heart failure and has sought to combine inhibition of angiotensin and neprilysin.

Neprilysin, a neutral endopeptidase, is associated with degradation of several natural vasoactive peptides such as natriuretic peptide, bradykinin, and adrenomedullin. Neprilysin inhibition increases these substances and counters the neurohormonal overactivation that leads to vasoconstriction, sodium retention, and cardiac remodeling.¹⁷

The ARB valsartan has been combined with the neprilysin inhibitor sacubitril to create the first angiotensin-neprilysin inhibitor (ARNI) (Table 5). The combination was selected to minimize the potential for angioedema.

PARADIGM-HF (the Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure trial)¹⁷ examined whether combined angiotensin-neprilysin inhibition was superior to ACE inhibition alone with enalapril in patients with chronic heart failure.

In PARADIGM-HF, 10,521 patients with NYHA class II, III, or IV heart failure were randomized to receive either sacubitril-valsartan or enalapril. The group receiving sacubitril-valsartan had significantly fewer deaths from cardiovascular causes and heart failure hospitalizations.¹⁷ An improvement in quality of life and NYHA functional class was also observed in the sacubitril-valsartan group.¹⁷

Sacubitril-valsartan underwent priority review by the US Food and Drug Administration and has been approved. Currently, it is indicated for the treatment of heart failure with reduced ejection fraction and NYHA class II, III, or IV symptoms. It should be avoided in patients who have previously experienced angioedema with an ACE inhibitor or ARB, in patients receiving aliskiren for diabetes, and in patients with hypersensitivity reactions to either of its components. Simultaneous use of sacubitril-valsartan and an ACE inhibitor should be avoided, and a washout period is recommended when transitioning from an ACE inhibitor to this combined agent.

Beta-blockers

In heart failure, there is increased sympathetic activation and associated elevations in norepinephrine levels, which may lead to deleterious long-term effects on cardiac function and structure. Beta-adrenergic receptor blockade is now known to be cardioprotective, but it was not always so; beta-blockers used to be contraindicated in patients with heart failure.

An early experience using beta-blockers in heart failure was described in 1975.^18,19 The first study to report a survival benefit of treating systolic heart failure with a beta-blocker was published in 1979.²⁰ Later, small controlled trials demonstrated a reduction in heart failure symptoms and improvement in left ventricular function and in NYHA functional class.²¹ Larger clinical trials have demonstrated a tremendous survival benefit with beta-blockers in heart failure, specifically carvedilol, extended-release metoprolol, and bisoprolol.

The US Carvedilol Heart Failure Study Group trial²² evaluated whether beta-blocker use in heart failure patients would reduce the rates of morbidity and mortality.²² The trial included 1,094 patients with symptomatic heart failure for at least 3 months and a left ventricular ejection fraction of 35% or less on background therapy including vasodilators, ACE inhibitors, and digoxin. Patients were randomized to receive either carvedilol or placebo. Carvedilol use was associated with a dramatic 65% risk reduction in mortality (7.8% with placebo vs 3.2% with carvedilol, P < .001) and a 27% risk reduction in hospitalizations (19.6% vs 14.1%, P = .036), leading to early trial termination.

CIBIS-II (the Cardiac Insufficiency Bisoprolol Study II)²³ investigated the effects of beta-blockers on survival and morbidity. CIBIS-II included 2,647 NYHA class III or IV patients with a left ventricular ejection fraction less than 35% on background medical therapy that included diuretics and ACE inhibitors. This trial was also terminated early, after demonstrating a significant survival benefit with bisoprolol.

MERIT-HF (the Metoprolol Extended Release Randomized Intervention Trial in Congestive Heart Failure)²⁴ evaluated if once-daily metoprolol would lower mortality rates  in patients with symptomatic heart failure. The study enrolled 3,991 NYHA class II–IV patients with chronic heart failure and a left ventricular ejection fraction of 40% or less. Like the previous two beta-blocker trials, MERIT-HF was terminated early, as it demonstrated a 34% reduction in all-cause mortality (7.2% risk of death per patient-year vs 11.0%, P = .00009).

The beta-blocker trials have shown that when added to background therapy, beta-blockers improve survival and reduce hospitalizations. However, when prescribing a beta-blocker, it is important to understand that not all beta-blockers are equal in the treatment of heart failure.

COMET (the Carvedilol or Metoprolol European Trial)²⁵ was the only head-to-head randomized control trial evaluating clinical outcomes in patients receiving carvedilol or metoprolol tartrate (not metoprolol succinate). In COMET, 1,511 patients with NYHA class II, III, or IV heart failure with a left ventricular ejection fraction of 35% or less were randomized to carvedilol or metoprolol tartrate. The primary end point of all-cause mortality occurred in 34% of the carvedilol group and 40% of the metoprolol tartrate group (P = .0017). There was no significant difference with regard to the composite end point of mortality and all-cause admissions.

Recommendations. The 2013 guidelines give a class IA recommendation for starting a beta-blocker (carvedilol, bisoprolol, or metoprolol succinate, Table 6) in patients with current or prior symptoms of heart failure.¹ Beta-blockers should be initiated with caution or avoided in patients with acutely decompensated heart failure with evidence of fluid overload.

Brain-type natriuretic peptide

Brain-type natriuretic peptide (BNP) or its amino-terminal cleavage product (NT-proBNP) originates in cardiomyocytes and is released by several triggers, most commonly cardiomyocyte stretch in the setting of volume or pressure overload.²⁶ The biologic significance of BNP includes natriuresis and vasodilation, renin-angiotensin system inhibition, and sympathetic nervous system modulation.²⁶

TIME-CHF (the Trial of Intensified vs. Standard Medical Therapy in Elderly Patients With Congestive HF)²⁷ investigated whether 18-month outcomes would be better if treatment were guided by N-terminal BNP levels rather than by symptoms. The BNP-guided strategy was not associated with a reduction in hospitalization or a survival benefit.

BATTLESCARRED (the NT-proBNP-Assisted Treatment to Lessen Serial Cardiac Readmissions and Death trial)²⁸ in 2009 showed that a BNP-guided management strategy significantly reduced mortality rates in patients under age 75 compared with standard medical therapy.

PROTECT (the Use of NT-proBNP Testing to Guide HF Therapy in the Outpatient Setting study)²⁹ also showed that a BNP-guided strategy was superior to usual care and was associated with reduced cardiovascular events and improved quality of life.²⁹

GUIDE IT-HF (the Guiding Evidence Based Therapy Using Biomarker Intensified Treatment in Heart Failure study), currently ongoing, is designed to assess the safety, efficacy and cost-effectiveness of a biomarker-guided strategy in 1,100 high-risk patients with heart failure with reduced ejection fraction. 

Recommendations. The 2013 ACC/AHA guidelines give a class IA recommendation for the use of BNP to support clinical decision-making, particularly in cases of clinical uncertainty.¹ BNP can also be used to establish prognosis or disease severity in chronic heart failure and to achieve optimal dosage of goal-directed medical therapy for euvolemic patients followed in a structured heart failure program.¹

Heart failure clinics

Continuity of care upon discharge from the hospital is currently in a state of evolution. Those diagnosed with heart failure can now experience more comprehensive posthospital care by virtue of disease management clinics. The name may vary by institution, but whether it is called a “diuresis clinic,” “bridge clinic,” or “heart failure clinic,” the goal is to improve guideline-driven care, educate the patient, and reduce heart failure hospitalizations. Heart failure clinics are designed to provide a smooth transition from inpatient to outpatient care and to encourage patient self-accountability in health maintenance thereafter.

Studies have shown that heart failure clinics are associated with better medication dosing, fewer hospitalizations, and lower healthcare costs.^30–32

Chronotropy: I_f inhibition

An elevated resting heart rate has been shown to be associated with increased cardiovascular morbidity and mortality.³³ Studies have shown that slowing the heart rate improves myocardial contraction and energy supply and reduces energy expenditure.³⁴ Ivabradine, a selective I_f (the f is for “funny”) channel inhibitor, slows the heart rate without other known cardiovascular effects.

SHIFT (the Systolic Heart Failure Treatment With the I_f Inhibitor Ivabradine Trial)³⁵ investigated whether isolated heart rate reduction with ivabradine would reduce adverse clinical outcomes in patients with symptomatic heart failure. SHIFT randomized 6,505 patients with a left ventricular ejection fraction of 35% or less, in sinus rhythm, with a heart rate of at least 70 beats per minute, on optimal medical therapy, and hospitalized within 12 months of enrollment to receive ivabradine or placebo. The primary end point was a composite of cardiovascular mortality and hospital admission for worsening heart failure. Outcomes varied by heart rates achieved, with the best outcomes in those with the lowest heart rates at trial conclusion.

Ivabradine (Table 7) is indicated for patients with symptomatic heart failure with a left ventricular ejection fraction less than 35%, in sinus rhythm, with a resting heart rate of at least 70 beats per minute, and either on a maximally tolerated beta-blocker or with a contraindication to beta-blockers.

Ivabradine should be avoided in patients who are in acute decompensated heart failure or are hypotensive (blood pressure < 90/50 mm Hg), as well as in patients with a significant conduction abnormality (sick sinus syndrome, sinoatrial block, third-degree atrioventricular block), hepatic impairment, or bradycardia (resting heart rate < 60 beats per minute).

Digoxin

Digoxin has been used in treating systolic heart failure for more than 70 years.^36,37

DIG (Digoxin Investigative Group trial)³⁸ evaluated the long-term effect of digoxin on rates of mortality and hospitalization for heart failure over a 3-year period. In patients with  a left ventricular ejection fraction less than 45%, digoxin had no effect on overall mortality when combined with diuretics and ACE inhibitors. However, the risk of hospitalization for worsening heart failure was significantly reduced with digoxin treatment.³⁸

Recommendations. Digoxin should be considered when patients are on guideline-recommended therapy but heart failure symptoms persist. It is commonly initiated at a dose of 0.125 to 0.25 mg. The target therapeutic range for digoxin is 0.5 to 0.9 ng/mL.¹ Digoxin toxicity can occur in patients with renal impairment, hypokalemia, hypomagnesemia, and hypothyroidism.

The 2013 ACC/AHA guidelines give a class IIA recommendation (treatment is “reasonable”) for digoxin in patients with heart failure with reduced ejection fraction unless contraindicated, to decrease hospitalizations for heart failure.¹

Diuretics

Clinical manifestations of volume overload in patients with heart failure are from excess salt and water retention leading to inappropriate volume expansion in both the vascular and extravascular space. Diuretics (Table 8) are the foundation of heart failure treatment. Most patients are first initiated on a combination of a loop diuretic and a low-sodium diet to improve symptoms.

The 2013 ACC/AHA guidelines give a class I recommendation for diuretics in patients with heart failure with reduced ejection fraction who have evidence of fluid retention, unless contraindicated, to improve symptoms.¹

Devices: ICDs

Patients with heart failure are at increased risk of sudden death and ventricular arrhythmias.³⁹ Previously, antiarrhythmic drugs were considered the standard of care for nonsustained ventricular tachycardia after myocardial infarction.

MADIT (the Multicenter Automatic Defibrillator Implantation Trial) investigated whether prophylactic implantation of an internal cardiac defibrillator would improve 5-year survival rates in patients with heart failure. Eligible patients had had a Q-wave or enzyme-positive myocardial infarction within 3 weeks of study entry. They also had had an episode of asymptomatic nonsustained ventricular tachycardia unrelated to an acute myocardial infarction. Additionally, the patients had a left ventricular ejection fraction less than 35%, and inducible, sustained, nonsuppressible ventricular tachyarrhythmia on electrophysiologic testing.⁴⁰

During the study, 15 patients in the defibrillator group died vs 39 in the conventional therapy group (P = .009).⁴⁰

MADIT II evaluated the potential survival benefit of a prophylactically implanted defibrillator in the absence of electrophysiologic testing to induce arrhythmias.⁴¹ MADIT II included 1,232 patients with prior myocardial infarctions and a left ventricular ejection fracton of 30% or less. Patients were randomized to receive an implanted cardioverter-defibrillator or conventional medical therapy. The primary end point was death from any cause.⁴¹

The mortality rate was 19.8% in the conventional therapy group vs 14.2% in the defibrillator group (hazard ratio 0.69, P = .016).⁴¹ Thus, MADIT-II confirmed the benefits of prophylactic implantable cardioverter-defibrillator therapy seen in the original MADIT, and additionally eliminated the need for an electrophysiology test prior to device implantation.

SCD-HeFT (the Sudden Cardiac Death in Heart Failure Trial) evaluated whether amiodarone or a conservatively programmed shock-only, single-lead implanted cardioverter-defibrillator would decrease the risk of death (all-cause) in a population with mild to moderate heart failure with ischemic and nonischemic causes.⁴² In this trial, 2,521 patients with an ejection fraction of 35% or less, in NYHA class II or III, and with stable heart failure were randomized to receive a single-chamber implantable cardioverter-defibrillator,  amiodarone, or placebo.

There were 244 deaths in the placebo group, 240 deaths in the amiodarone group (P = .53 compared with placebo), and 182 deaths in the defibrillator group (P = .007 compared with placebo).⁴²

Recommendations. The 2013 ACC/AHA guideline¹ gives implantable defibrillator therapy a class IA recommendation for the primary prevention of sudden cardiac death in selected patients with nonischemic cardiomyopathy or ischemic cardiomyopathy at least 40 days after a myocardial infarction and 90 days after percutaneous coronary intervention or coronary artery bypass grafting; with a left ventricular ejection fraction of 35% or less; and NYHA class II or III symptoms on chronic goal-directed medical management.

This therapy receives a class IB recommendation for primary prevention of sudden cardiac death to reduce total mortality in selected patients at least 40 days after myocardial infarction with a left ventricular ejection fraction of 30% or less and NYHA class I symptoms while receiving goal-directed medical therapy.

Implantable cardioverter-defibrillators are not recommended in patients who otherwise have a life expectancy of less than 1 year.

Devices: Cardiac resynchronization therapy

From 25% to 30% of heart failure patients have an intraventricular conduction abnormality,^43,44 which can result in abnormalities of systolic and diastolic function. Biventricular pacing, in which a pacing lead is placed in the coronary sinus in addition to the right atrium and right ventricle, optimizes synchronization of ventricular contraction.^43,44

MUSTIC (the Multisite Stimulation in Cardiomyopathies study) was a randomized trial designed to assess the efficacy of biventricular pacing (also known as cardiac resynchronization therapy) in heart failure patients.⁴⁴ Entry criteria included NYHA class III heart failure for at least 1 month, left ventricular ejection fraction less than 35%, left ventricular end-diastolic diameter greater than 60 mm, and QRS duration longer than 150 ms. Patients were followed up at 9 and 12 months with 6-minute walking distance, peak oxygen consumption, changes in NYHA class, and left ventricular systolic function by echocardiography or radionuclide testing. Quality of life was assessed by the Minnesota Living With Heart Failure Questionnaire.

At 12 months, patients could walk significantly farther in 6 minutes, and their peak oxygen consumption had increased. They also reported significant improvement in quality of life, and NYHA class improved by 25%. MUSTIC was the first study to show a benefit in exercise tolerance, quality of life, improvement in cardiac performance, and reduction in heart failure symptoms with the use of biventricular pacing at 1 year.

MIRACLE (the Multicenter InSync Randomized Clinical Evaluation) validated the findings seen in MUSTIC by using a larger population size and a double-blinded method.⁴⁵ Compared with a control group, patients who underwent cardiac resynchronization therapy could walk farther in 6 minutes and scored better in NYHA class, quality of life, and left ventricular ejection fraction.⁴⁵

Recommendations. The 2013 ACC/AHA guidelines¹ give cardiac resynchronization therapy a class IA/B indication for NYHA class II, III, or IV patients on goal-directed medical therapy in sinus rhythm with left ventricular ejection fraction 35% or less, left bundle branch block, and QRS duration of 150 ms or more.¹

Devices: Implantable sensors

The future of ambulatory heart failure management may include implantable pulmonary artery pressure sensors.

The CardioMEMS is a permanently implantable pressure measurement system designed to provide daily pulmonary artery pressure measurements in an ambulatory setting with a goal of reducing heart failure-related hospitalizations. Through a transvenous delivery system, an implantable, battery-free sensor is positioned in the distal pulmonary artery.^46,47

CHAMPION (the CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in NYHA Class III Patients trial) was one of the first major trials to assess the safety and efficacy of implantable pulmonary artery pressure monitoring systems.⁴⁶ The study device was associated with a significant reduction in mean pulmonary artery pressures, fewer heart failure hospitalizations, and better quality of life. The length of stay for heart failure-related hospitalizations was also significantly shorter in the CardioMEMs group.⁴⁶

Exercise

Patients with heart failure routinely experience a decline in functional capacity. This decline manifests as reduced exercise tolerance and poor quality of life, usually resulting in a physician recommendation to rest and paradoxical deconditioning and possible progression of symptoms.

Several studies have shown that cardiac rehabilitation has improved outcomes in heart failure patients.⁴⁸ Cardiac rehabilitation is a supervised program that helps patients with exercise training, healthy living, education, and psychosocial counseling.

HF-ACTION (Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training) is the largest randomized trial performed to determine whether aerobic exercise training reduces all-cause mortality or all-cause hospitalization and improves quality of life in patients with stable heart failure.⁴⁹ Although the reduction in end points was initially not statistically significant, after adjusting for highly prognostic predictors of poor outcomes (cardiopulmonary exercise time, left ventricular ejection fraction, atrial fibrillation, and depression), exercise training was found to reduce the incidence of all-cause mortality or all-cause hospitalization by 11% (P = .03).⁴⁹

Recommendations. Based on the results of HF-ACTION and several smaller studies, the ACC/AHA guidelines give exercise training a class IA recommendation as a safe and effective activity for patients with heart failure who are able to participate, to improve functional status.¹ A class IIA recommendation is given to cardiac rehabilitation for the improvement of functional capacity, exercise duration, quality of life, and mortality rates.¹

End-stage heart failure: Recognition

Despite adequate titration of goal-directed medical therapy, a portion of patients with heart failure with reduced ejection fraction ultimately progress to stage D, also termed “advanced” heart failure. The 5-year survival rate for patients with heart failure overall is 50%, but the 1-year mortality rate for those with advanced heart failure exceeds 50%.⁵⁰

Because the high rates of morbidity and mortality can potentially be lowered, recognition of heart failure disease progression is imperative so that patients can be promptly referred for therapies such as inotropic infusion, mechanical circulatory support, and cardiac transplant, as well as end-of-life care such as hospice.¹

The ACC/AHA¹ have published clinical events and findings useful in identifying patients with advanced heart failure:

• Two or more hospitalizations or emergency department visits for heart failure in the past year
• Progressive deterioration in renal function (eg, elevation in creatinine or blood urea nitrogen)
• Weight loss without other cause
• Intolerance to ACE inhibitors due to hypotension or worsening renal function
• Inability to tolerate beta-blockers due to worsening heart failure or hypotension
• Systolic blood pressure often below 90 mm Hg
• Persistent dyspnea with dressing or bathing requiring rest
• Inability to walk one block on level ground due to dyspnea or fatigue
• Recent need to escalate diuretics to maintain volume status, often reaching daily dose equivalent to furosemide more than 160 mg/day or use of supplemental metolazone
• Progressive decline in serum sodium, usually to below 133 mmol/L
• Frequent shocks from implanted cardiac defibrillator.

End-stage heart failure: Left ventricular assist devices

For patients with refractory heart failure despite optimal medical management, advanced therapies such as heart transplant or ventricular assist devices have been proven to be durable options. These mechanical circulatory support devices “unload” the diseased ventricle and maintain cardiac output to vital organs.⁵¹ They were initially designed as temporary support to allow ventricular recovery or as a bridge to cardiac transplant. However, they have also evolved into permanent (“destination”) therapy.⁵²

REMATCH (the Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive HF trial) was the landmark study that showed that left ventricular assist device implantation resulted in a survival benefit and an improved quality of life in patients with advanced heart failure ineligible for cardiac transplant, compared with medical management.⁵⁰ Implantation of a left ventricular assist device was associated with a 27% absolute reduction in the 1-year mortality rate.⁵⁰

Since the National Institutes of Health’s artificial heart program was launched in 1964, there has been tremendous progress in the development of mechanical circulatory devices.⁵⁰ The results of REMATCH were promising, but the 2-year survival rate was still only 23%, leaving a lot to be desired.

The HeartMate II (Thoratec) trial compared an axial continuous-flow device vs the previously established pulsatile left ventricular assist device, and noted a 2-year survival of 58% with the continuous flow device vs  24% with the pulsatile device (P = .008).⁵³

ADVANCE (Evaluation of the HeartWare Left Ventricular Assist Device for the Treatment of Advanced Heart Failure) showed similar efficacy of the HVAD (Heartware), a centrifugal continuous-flow LVAD currently in use.⁵⁴

The next generation of continuous-flow left ventricular assist devices are currently in clinical trials in the United States and include the axial flow MVAD (Heartware) and centrifugal flow Heartmate III (Thoratec).

We emphasize the importance of early identification of patients with advanced disease who may qualify for and benefit from such therapies.

The management of heart failure is evolving. In the 1960s, the standard heart failure medical regimen included digoxin, diuretics, and the recommendation of rest. This contrasts with the current era, in which medical regimens include neurohormonal blockade, diuretics, and the promotion of physical activity.⁵⁵ Since the publication of the 2013 heart failure guidelines, new medical and device options have emerged that have been proven to either improve survival or reduce hospitalizations. The development of clinical guidelines promotes evidence-based practice and overcomes the inertia of practice patterns based on anecdotal evidence.

Several approaches to the management of heart failure have been recommended. A major effort should be made to identify those at risk for heart failure (stage A) and to implement risk factor modification. Treatment of hypertension, diabetes mellitus, and dyslipidemia decreases the risk of heart failure.¹

For patients with evidence of structural heart disease with and without symptoms, Figure 1 summarizes a guideline approach to the management of heart failure. It should be stressed that guidelines are meant to guide management, but do not serve as a substitute for sound clinical judgment.

Heart failure is the common final pathway of all cardiac pathology, and understanding the neurohormonal response and maladaptive physiology has led to the development of novel therapeutics and devices. At present, the field of cardiology may not be able to remove the “failure” from heart failure, but we can make every effort to prevent failure of treatment delivery and reduce resource utilization and morbidity associated with this syndrome.

Acknowledgments: We would like to thank Chankya Dahagam and Cynthia Obenwa for their valuable contribution in the preparation of this manuscript.

To the Editor: Thanks for the concise review of obstructive sleep apnea (OSA) in the January 2016 issue.¹ I offer the following comments and questions:

1. Risk factors for OSA include large neck circumference, which in Table 1 is defined as larger than 40 cm (15.75 inches), which would include shirt collar sizes 16 and above. In the second paragraph of the text, large neck circumference is defined as greater than 17 inches in men, which would include collar sizes above 17. The definition of a large neck as larger than 40 cm must obviously be more sensitive for predicting OSA, and the definition of greater than 17 inches more specific. Which do the authors use in clinical practice?

2. The American Academy of Sleep Medicine is quoted as recommending home OSA screening “if direct monitoring of the response to non-[continuous positive airway pressure] treatments for sleep apnea is needed.”² However, the need for direct monitoring would seem to be a contraindication to home testing rather than an indication. If this statement is correct as written, would the authors explain why and how specific non-CPAP treatments for OSA are more amenable to monitoring at home than in the sleep lab?

3. Patients with Parkinson disease are at risk for both OSA and hypotension, making them generally an exception to the association of OSA with hypertension.³

4. The home overnight OSA test often consists of a pulse oximeter worn for 8 hours at night, taped to a finger.⁴ This simple, inexpensive test for OSA detects episodes of apnea or hypopnea that result in arterial desaturation. Is it beneficial to also document episodes of apnea or hypopnea that do not result in arterial desaturation? These episodes are included in the 17% false-negative rate for home OSA testing mentioned in the text. Are these episodes important clinically, other than for prognosis in patients who may go on to develop apneic episodes severe enough to cause desaturation?

5. Lastly, the authors may wish to comment on the importance of diagnosing and treating OSA in patients who plan to have elective surgery under general anesthesia, which can lead to profound sleep apnea in the recovery room, with associated morbidity and death.⁵

To the Editor: Thanks for the concise review of obstructive sleep apnea (OSA) in the January 2016 issue.¹ I offer the following comments and questions:

1. Risk factors for OSA include large neck circumference, which in Table 1 is defined as larger than 40 cm (15.75 inches), which would include shirt collar sizes 16 and above. In the second paragraph of the text, large neck circumference is defined as greater than 17 inches in men, which would include collar sizes above 17. The definition of a large neck as larger than 40 cm must obviously be more sensitive for predicting OSA, and the definition of greater than 17 inches more specific. Which do the authors use in clinical practice?

2. The American Academy of Sleep Medicine is quoted as recommending home OSA screening “if direct monitoring of the response to non-[continuous positive airway pressure] treatments for sleep apnea is needed.”² However, the need for direct monitoring would seem to be a contraindication to home testing rather than an indication. If this statement is correct as written, would the authors explain why and how specific non-CPAP treatments for OSA are more amenable to monitoring at home than in the sleep lab?

3. Patients with Parkinson disease are at risk for both OSA and hypotension, making them generally an exception to the association of OSA with hypertension.³

4. The home overnight OSA test often consists of a pulse oximeter worn for 8 hours at night, taped to a finger.⁴ This simple, inexpensive test for OSA detects episodes of apnea or hypopnea that result in arterial desaturation. Is it beneficial to also document episodes of apnea or hypopnea that do not result in arterial desaturation? These episodes are included in the 17% false-negative rate for home OSA testing mentioned in the text. Are these episodes important clinically, other than for prognosis in patients who may go on to develop apneic episodes severe enough to cause desaturation?

5. Lastly, the authors may wish to comment on the importance of diagnosing and treating OSA in patients who plan to have elective surgery under general anesthesia, which can lead to profound sleep apnea in the recovery room, with associated morbidity and death.⁵

To the Editor: Thanks for the concise review of obstructive sleep apnea (OSA) in the January 2016 issue.¹ I offer the following comments and questions:

1. Risk factors for OSA include large neck circumference, which in Table 1 is defined as larger than 40 cm (15.75 inches), which would include shirt collar sizes 16 and above. In the second paragraph of the text, large neck circumference is defined as greater than 17 inches in men, which would include collar sizes above 17. The definition of a large neck as larger than 40 cm must obviously be more sensitive for predicting OSA, and the definition of greater than 17 inches more specific. Which do the authors use in clinical practice?

2. The American Academy of Sleep Medicine is quoted as recommending home OSA screening “if direct monitoring of the response to non-[continuous positive airway pressure] treatments for sleep apnea is needed.”² However, the need for direct monitoring would seem to be a contraindication to home testing rather than an indication. If this statement is correct as written, would the authors explain why and how specific non-CPAP treatments for OSA are more amenable to monitoring at home than in the sleep lab?

3. Patients with Parkinson disease are at risk for both OSA and hypotension, making them generally an exception to the association of OSA with hypertension.³

4. The home overnight OSA test often consists of a pulse oximeter worn for 8 hours at night, taped to a finger.⁴ This simple, inexpensive test for OSA detects episodes of apnea or hypopnea that result in arterial desaturation. Is it beneficial to also document episodes of apnea or hypopnea that do not result in arterial desaturation? These episodes are included in the 17% false-negative rate for home OSA testing mentioned in the text. Are these episodes important clinically, other than for prognosis in patients who may go on to develop apneic episodes severe enough to cause desaturation?

5. Lastly, the authors may wish to comment on the importance of diagnosing and treating OSA in patients who plan to have elective surgery under general anesthesia, which can lead to profound sleep apnea in the recovery room, with associated morbidity and death.⁵

Although vitamin and mineral deficiencies are relatively uncommon in the United States and other developed countries, physicians must be alert to them, particularly in specific populations such as infants, pregnant women, alcoholics, vegetarians, people of lower socioeconomic status, and patients on dialysis, on certain medications, or with a history of malabsorption or gastrointestinal surgery. The skin is commonly affected by nutritional deficiencies and can provide important diagnostic clues.

This article reviews the consequences of deficiencies of zinc and vitamins A, B₂, B₃, B₆, and C, emphasizing dermatologic findings.

ZINC DEFICIENCY

Case: A colon cancer patient on total parenteral nutrition

A 65-year-old woman who had been on total parenteral nutrition for 4 months after undergoing surgical debulking for metastatic colon cancer was admitted for evaluation of a rash on her face and extremities and failure to thrive. The rash had started 10 days earlier as small red papules and vesicles on the forehead and progressed to cover the forehead and lips. She had been prescribed prednisone 20 mg daily, but the condition had not improved.

Physical examination revealed numerous violaceous papules, plaques, and vesicles on her face, legs, and feet (Figure 1). The vesicles were tender to touch and some were crusted. Biopsy of a lesion on her leg revealed psoriasiform dermatitis with prominent epidermal pallor and necrosis (Figure 2), suggestive of a nutritional deficiency.

Blood testing revealed low levels of alkaline phosphatase and zinc. She was started on zinc supplementation (3 mg/kg/day), and her cutaneous lesions improved within a month, confirming the diagnosis of zinc deficiency.

Zinc is an essential trace element

Zinc is an essential trace element required for function of many metalloproteases and transcription factors involved in reproduction, immunology, and wound repair. Additionally, its antioxidant properties help prevent ultraviolet radiation damage.¹

The recommended dietary allowance (RDA) for zinc is 11 mg/day for men and 8 mg/day for women, with higher amounts for pregnant and lactating women.¹ The human body does not store zinc, and meat and eggs are the most important dietary sources.¹

The normal plasma zinc level is 70 to 250 µL/dL, and hypozincemia can be diagnosed with a blood test. For the test to be accurate, zinc-free tubes should be used, anticoagulants should be avoided, the blood should not come into contact with rubber stoppers, and blood should be drawn in the morning due to diurnal variation in zinc levels. Additionally, zinc levels may be transiently low secondary to infection. Thus, the clinical picture, along with zinc levels, histopathology, and clinical response to zinc supplementation are necessary for the diagnosis of zinc deficiency.²

Since zinc is required for the activity of alkaline phosphatase (a metalloenzyme), serum levels of alkaline phosphatase correlate with zinc levels and can be used as a serologic marker for zinc levels.³

Zinc deficiency is a worldwide problem, with a higher prevalence in developing countries. It can result from either inadequate diet or impaired absorption, which can be acquired or inherited.

Clinical forms of zinc deficiency

Acrodermatitis enteropathica, an inherited form of zinc deficiency, is due to a mutation in the SLC39A4 gene encoding a zinc uptake protein.⁴ Patients typically present during infancy a few weeks after being weaned from breast milk. Clinical presentations include diarrhea, periorificial (eg, around the mouth) and acral dermatitis, and alopecia, although only 20% of patients have all these findings at presentation.⁵ Occasionally, diaper rash, photosensitivity, nail dystrophy, angular stomatitis, conjunctivitis, blepharitis, and growth retardation are observed. Serum levels of zinc and alkaline phosphatase are low.⁵ Clinical and serologic markers improve within 2 to 3 weeks with oral zinc supplementation (2–3 mg/kg/day).

Acquired forms of zinc deficiency are linked to poor socioeconomic status, diet, infections, renal failure, pancreatic insufficiency, cystic fibrosis, and malabsorption syndromes.^1,6,7 Cutaneous findings in acquired cases of zinc deficiency are similar to those seen in acrodermatitis enteropathica. Periorificial lesions are a hallmark of this condition, and angular cheilitis is an early manifestation. Eczematous annular plaques typically develop in areas subjected to repeated friction and pressure and may evolve into vesicles, pustules, and bullae.² On biopsy study, lesions are characterized by cytoplasmic pallor, vacuolization, and necrosis of keratinocytes, which are common findings in nutritional deficiencies.⁸ Dystrophic nails, structural hair changes, and diminished growth of both hair and nails have been reported.²

Cutaneous lesions due to hypozincemia respond quickly to zinc supplementation (1–3 mg/kg/day), usually without permanent damage.² However, areas of hypo- and hyperpigmentation may persist.

VITAMIN C DEFICIENCY

Case: A lung transplant recipient on peritoneal dialysis

A 59-year-old bilateral lung transplant patient with a history of chronic kidney disease on peritoneal dialysis for the past 2 years was admitted for peritonitis. He had developed tender violaceous papules and nodules coalescing into large plaques on his arms and perifollicular purpuric macules on both legs 3 days before admission (Figure 3). The lesions were painful to the touch, and some bled at times. Tender gums, bilateral edema, and corkscrew hair were also noted (corkscrew hair is shown in another patient in Figure 4).

Biopsy of a lesion on the forearm was consistent with lymphangiectasia secondary to edema. Staining for bacteria and fungi was negative.

Serologic investigation revealed low vitamin C serum levels (7 µmol/L, reference range 23–114 µmol/L). Supplementation with 1 g/day of vitamin C was started and resulted in gradual improvement of the purpura. The patient died 4 months later of complications of comorbidities.

An important antioxidant

Vitamin C, or ascorbic acid, is an important antioxidant involved in the synthesis of tyrosine, tryptophan, and folic acid and in the hydroxylation of glycine and proline, a required step in the formation of collagen.⁹ Humans cannot synthesize vitamin C and must acquire it in the diet.⁹ Plants are the most important dietary sources.⁹ Although vitamin C is generally not toxic and its metabolites are renally cleared, diarrhea and other gastrointestinal disturbances can occur if large amounts are ingested.¹⁰

Vitamin C deficiency is rare in developed countries and is linked to malnutrition. Risk factors include alcoholism, severe psychiatric illness, anorexia, and low socioeconomic status. Moreover, multiple conditions including stress, viral illness, smoking, fever, and use of antibiotics lead to diminished vitamin C bioavailability.⁹ Patients on dialysis are at increased risk of vitamin C deficiency since it is lost during the process.¹¹

The RDA for vitamin C is 90 mg for men and 75 mg for women, with higher requirements during pregnancy and lactation.¹² This is much higher than the amount needed to prevent scurvy, 10 mg/day.¹³

Scurvy is the classic manifestation

The classic manifestations of vitamin C deficiency are scurvy and Barlow disease, also known as infantile scurvy.

Early manifestations of vitamin C deficiency such as fatigue, mood changes, and depression appear after 1 to 3 months of inadequate intake.¹³ Other manifestations are anemia, bone pain, hemorrhage into joints, abnormal vision, and possibly osteoporosis.

Cutaneous findings are a hallmark of scurvy. Follicular hyperkeratosis with fragmented corkscrew hair and perifollicular hemorrhages on posterior thighs, forearms, and abdomen are pathognomonic findings that occur early in the disease.¹³ The cutaneous hemorrhages can become palpable, particularly in the lower limbs. Diffuse petechiae are a later finding along with ecchymosis, particularly in pressure sites such as the buttocks.¹³ “Woody edema” of the legs with ecchymosis, pain, and limited motion can also arise.¹⁴ Nail findings including koilonychia and splinter hemorrhages are common.^13,14

Vitamin C deficiency results in poor wound healing with consequent ulcer formation due to impaired collagen synthesis. Hair abnormalities including corkscrew and swan-neck hairs are common in scurvy due to vitamin C’s role in disulfide bond formation, which is necessary for hair synthesis.¹³

Scurvy also affects the oral cavity: gums typically appear red, swollen, and shiny earlier in the disease and can become black and necrotic later.¹³ Loosening and loss of teeth is also common.¹³

Scurvy responds quickly to vitamin C supplementation. Patients with scurvy should receive 1 to 2 g of vitamin C daily for 2 to 3 days, 500 mg daily for the next week, and 100 mg daily for the next 1 to 3 months.¹⁵ Fatigue, pain, and confusion usually improve in the first 24 hours of treatment, cutaneous manifestations respond in 2 weeks, and hair within 1 month. Complete recovery is expected within 3 months on vitamin C supplementation.¹⁵

VITAMIN A DEFICIENCY

Case: A girl with short-bowel syndrome on total parenteral nutrition

A 14-year-old girl who had been on total parenteral nutrition for the past 3 years due to short-bowel syndrome was admitted for evaluation for a second small-bowel transplant. She complained of dry skin and dry eyes. She was found to have rough, toad-like skin with prominent brown perifollicular hyperkeratotic papules on buttocks and extremities (Figure 5). Additionally, corkscrew hairs were noted. Physical examination was consistent with phrynoderma.

Blood work revealed low levels of vitamin A (8 µg/dL, reference range 20–120 µg/dL) and vitamin C (20 µmol/L, reference range 23–114 µmol/L). After bowel transplant, her vitamin A levels normalized within 2 weeks and her skin improved without vitamin A supplementation.

Essential for protein synthesis

Vitamin A is a group of fat-soluble isoprenoids that includes retinol, retinoic acid, and beta-carotene. It is stored in hepatic stellate cells, which can release it in circulation for distribution to peripheral organs when needed.¹⁶

Vitamin A is essential for protein synthesis in the eye and is a crucial component of phototransduction.¹⁷ It is also an important modulator of the immune system, as it enhances cytotoxicity and proliferation of T cells while suppressing B-cell proliferation.¹⁸ Additionally, vitamin A plays an important role in the skin, where it promotes cell mitosis and increases epithelial thickness, the number of Langerhans cells, and glycosaminoglycan synthesis.^19–21

Deficiency associated with malabsorption, liver disease, small-bowel surgery

Vitamin A deficiency is rare in developed countries overall, but it is associated with malabsorption, liver disease, and small-bowel surgery.²² Indeed, 4 years after undergoing bariatric surgery, 69% of patients in one series had deficiencies in vitamin A and other fat-soluble vitamins.²³ The typical manifestations are nyctalopia (night blindness) and xerophthalmia (inability to produce tears).

Phrynoderma, or “toad skin,” is a cutaneous manifestation of vitamin A deficiency. The association between phrynoderma and vitamin A deficiency was established in 1933 when prisoners in Africa with nyctalopia, xerophthalmia, and phrynoderma showed improvement in all three conditions when treated with cod oil, which is rich in vitamin A.²⁴

Phrynoderma is characterized by dry, hyperkeratotic papules with central intrafollicular plugs projecting from hair follicles.²⁵ The lesions are typically symmetrically distributed on the face, the skull, and the extensor surfaces of the shoulders, buttocks, and extremities, but they can extend to the entire body in severe cases.²⁵ They typically get better with improved nutrition.

Evidence is mounting to suggest phrynoderma is a cutaneous manifestation of diverse nutritional deficiencies, not just vitamin A. For example, some children with phrynoderma have normal levels of vitamin A,²⁶ and a trial showed that patients with phrynoderma benefited from intramuscular injections of either vitamin A or vitamin B complex, particularly when also treated with topical keratolytics.²⁷ Thus, patients who present with the typical lesions of phrynoderma should be screened for nutritional deficiencies beyond vitamin A.

VITAMIN B₆ DEFICIENCY

Case: A woman with sepsis

A 62-year-old woman with a 4-year history of unspecified dermatitis, intertriginous rashes, and skin ulcerations with polymicrobial infections was admitted for sepsis. She reported that her rash had worsened over the previous 2 weeks. Physical examination revealed generalized xerosis, an inflamed bright red tongue with atrophy of distal papillae, and red painful erosions in intertriginous areas (Figure 6).

Blood testing revealed low levels of vitamin B₂ (< 5.0 nmol/L, reference range 6.2–39 nmol/L) and vitamin B₆ (3.1 nmol/L, reference range 20–125 nmol/L). She was started on supplementation with vitamin B₆ 50 mg/day and vitamin B₂ 200 mg/day, and her dermatitis and ulcers improved.

Pyridoxine and its derivatives

Pyridoxine and its derivatives are collectively known as vitamin B₆. Vitamin B₆ can be stored throughout the body, particularly in muscle and the liver, whereas its oxidized version is excreted mostly in the urine.^28,29 Vitamin B₆ serves as a cofactor to more than 140 enzymes, it is required for tryptophan metabolism and synthesis of nicotinic acid, and it is a cofactor for alanine aminotransferase and aspartate aminotransferase.^28,29

Vitamin B₆ deficiency is rare in the general population. The median daily intake is 2 mg/day for men and 1.5 mg/day for women, whereas the RDA for adults is 1.3 mg/day. No signs of vitamin B₆ deficiency have been noted at intakes greater than 0.5 mg/day in clinical studies.²⁸

However, chronic alcoholism poses a high risk of this deficiency because it decreases the intake of vitamin B₆ and decreases the ability of the liver to store it. Additionally, patients with eclampsia or preeclampsia or who are on dialysis have higher vitamin B₆ requirements.²⁸ Certain medications are also associated with a low vitamin B₆ level, in particular the antituberculosis medication isoniazid, penicillamine, and hydralazine.²⁸

Although clinical manifestations of vitamin B₆ deficiency are rare, subclinical deficiency may be common, particularly in the elderly,²⁸ as up to 23% of people ages 65 to 75 and 40% of those older than 85 have vitamin B₆ deficiency.^30,31

Features of vitamin B₆ deficiency

Vitamin B₆ deficiency is associated with anemia (hypochromic, microcytic, iron-refractory), impaired immune function, seizures, peripheral neuropathy, and glossitis. Experimentally induced deficiency of vitamin B₆ results in periorificial dermatitis within 3 weeks.³² Intriguingly, multiple studies have shown an inverse correlation between B₆ levels and diverse cancers, including colorectal, pancreatic, and lung cancer.²⁸

Given its role in the synthesis of nicotinic acid, vitamin B₆ deficiency results in abnormal levels of B₃. Thus, vitamin B₆ deficiency may result in a pellagra-like presentation (reviewed in detail below in the discussion of vitamin B₃ deficiency). In this case, giving vitamin B₃ does not result in significant improvement, and this failure helps to establish the diagnosis of vitamin B₆ deficiency.³² It is believed that pellagrous lesions in vitamin B₆ deficiency are due to decreased synthesis of proline from ornithine, as suggested by decreased levels of the enzyme ornithine aminotransferase in patients with low vitamin B₆.³³ Other cutaneous manifestations of vitamin B₆ deficiency include eczema and seborrheic dermatitis.³³

Vitamin B₆ can be measured in blood and urine. Although these levels only reflect recent intake, plasma values lower than 20 nmol/L are indicative of vitamin B₆ deficiency.³⁴ Therapeutic oral supplementation of vitamin B₆ is the treatment of choice. Vitamin B₆ treatment is safe, but exposure to high levels of vitamin B₆ may result in photosensitivity and dermatitis.³⁵

Vitamin B₂ (riboflavin) deficiency

Riboflavin, or vitamin B₂, is a water-soluble vitamin involved in diverse reduction-oxidation reactions. Its active forms—flavin adenine dinucleotide and flavin mononucleotide—act as electron carriers in the respiratory electron transfer chain, and the former is necessary for the oxidation of fatty acids.³⁶ The human body does not store riboflavin, and excess intake is excreted in the urine.³⁶

Milk, dairy products, and meat are the major dietary sources of vitamin B₂. Additionally, some colonic bacteria synthesize it and provide an additional source.³⁶ Patients whose diets are low in dairy and meat products, in particular vegetarians, alcoholics, and the elderly, are at risk of this deficiency. Other populations at risk are pregnant women, lactating women, premature infants, infants exposed to phototherapy for hyperbilirubinemia, and infants of mothers with low vitamin B₂ levels.^36,37

The RDA for vitamin B₂ is 1.3 mg/day for men and 1.1 mg/day per women, with higher requirements for pregnant and lactating women. Fortunately, the median intake of riboflavin from diet in the United States is 2 mg/day for men and 1.5 mg/day for women.³⁸

Features of vitamin B₂ deficiency

Features of vitamin B₂ deficiency include angular stomatitis, glossitis, cheilosis, nasolabial dermatitis, and rarely corneal vascularization.^39,40 Dermatitic lesions around the scrotum and labia are common and are in many cases the initial manifestation of vitamin B₂ deficiency.^39,40 Riboflavin deficiency during development results in muscular, skeletal, and gastrointestinal abnormalities. In adults, riboflavin deficiency is associated with anemia, decreased iron absorption, neurodegeneration, and peripheral neuropathy.³⁶

Vitamin B₂ deficiency usually coexists with other deficiencies, and riboflavin is involved in the metabolism of other B vitamins including B₃, B₆, B₉ (folate), and B₁₂. Thus, the clinical presentation of vitamin B₂ deficiency is similar to that of vitamin B₃ and B₆ deficiency (reviewed above and below) and has been described as pellagra sine pellagra (pellagra without pellagra). Moreover, correction of riboflavin deficiency results in increased levels of vitamin B₃ and B₆.³⁶

Vitamin B₂ levels can be measured in the urine and blood.³⁷ Oral supplementation is safe (up to 60 mg/day) and is the treatment of choice.^36,38 Clearance of lesions within 3 to 5 days of riboflavin supplementation confirms the diagnosis.⁴⁰

Vitamin B₃ (niacin) deficiency

Niacin, or vitamin B₃, is a water-soluble vitamin abundant in meat, eggs, and legumes. It is an essential cofactor for coenzyme I and coenzyme II; therefore, it plays a crucial role in ATP synthesis, glycolysis, and metabolism of fatty acids and amino acids.^41,42

Most niacin is acquired in the diet, but humans can synthesize it from tryptophan in the presence of vitamin B₆ and thiamine.⁴² Thus, a deficiency in tryptophan, vitamin B₆, or thiamine can also lead to low niacin, and  an excess of dietary leucine can interfere with niacin synthesis and result in deficiency.⁴²

The RDA for niacin is 6 to 20 mg/day, based on sex and age, with higher requirements for pregnant and lactating women.³⁸

Pellagra, the clinical manifestation

Pellagra is the clinical manifestation of niacin deficiency, although it is thought that lack of tryptophan, vitamin B₆, or thiamine may also be required for clinical symptoms to appear.⁴¹

Sporadic cases of pellagra occur in homeless people, alcoholics, drug abusers, people with anorexia, and food faddists.^41,42 Symptoms typically develop after about 50 days of a niacin-free diet.⁴¹ Pellagra may also develop due to impaired absorption or metabolism, particularly in patients with prolonged diarrhea, colitis, ileitis, hepatic cirrhosis, or Hartnup disease.^42–45 Certain medications, eg, isoniazid, 5-fluorouracil, azathioprine, and 6-mercaptopurine, interfere with niacin synthesis and may induce pellagra in susceptible patients.⁴²

The clinical course of pellagra is often described by the four “Ds”: dermatitis, dementia, diarrhea, and, when not corrected, death. Early symptoms of insufficient vitamin B₃ are weakness, fatigue, loss of appetite, depression, and mood changes.⁴²

The cutaneous manifestations of pellagra are impressive and include photosensitive eruptions, perineal lesions, and thickened and pigmented skin.⁴¹ Biopsy of affected and unaffected skin in pellagra patients shows abnormal keratinization.

Photosensitivity is an initial manifestation of pellagra.⁴⁶ It is believed that vitamin B₃ deficiency results in a lack of urocanic acid, a compound that protects against ultraviolet B damage and accumulation of kynurenic acid, a known phototoxic agent.⁴⁷

The initial stage of acute pellagra can resemble a sunburn on the face, neck, and dorsal extremities⁴⁷ that becomes darker with time instead of fading.⁴⁶ Sharply demarcated hyperpigmented areas on the arms and legs are known as the “glove” and “boot” of pellagra.⁴⁶ Nearly all patients have involvement of the dorsum of the hand.⁴² The Casal necklace may be present, a characteristic eruption observed in up to 76% of patients on the front of the neck in the region of C3-C4.⁴⁸