Heart failure in African Americans: Disparities can be overcome
ABSTRACTAfrican Americans are disproportionately affected by heart failure, with a high prevalence at an early age. Hypertension, diabetes, obesity, and chronic kidney disease are all common in African Americans and all predispose to heart failure. Neurohormonal imbalances, endothelial dysfunction, genetic polymorphisms, and socioeconomic factors also contribute. In general, the same evidence-based treatment guidelines that apply to white patients with heart failure also apply to African Americans. However, the combination of hydralazine and isosorbide dinitrate is advised specifically for African Americans.
KEY POINTS
- The natural history, epidemiology, and outcomes of heart failure in African Americans differ from those in whites.
- Hypertension is the predominant risk factor for heart failure in African Americans, and aggressive management of hypertension may substantially reduce the incidence and consequences of heart failure in this population.
- Heart failure in African Americans should be treated according to the same evidenced-based strategies as in the general population. In addition, a combination of isosorbide dinitrate and hydralazine is recommended in African Americans.
- Many questions remain unanswered, since African Americans have been markedly underrepresented in clinical trials.
Healthy neighborhoods, healthy people
Neighborhoods can be designed and built with wellness in mind, incorporating features such as access to healthy food and walkability. Living in such neighborhoods leads to more physical activity and less obesity, although this relationship may be less robust in African Americans.46–49
Environmental factors are multifactorial in African Americans and extend beyond those afforded by the built environment. For instance, lack of safety may hinder the potential benefit of an otherwise walkable neighborhood. These interactions are highly complex, and more investigation is needed to determine the effect of built environments on risk factors in African Americans.
DRUG THERAPY FOR HEART FAILURE IN AFRICAN AMERICANS
Use standard therapies
ACE inhibitors, beta-blockers, and aldosterone antagonists are the standard of care in heart failure, with digoxin (Lanoxin) and diuretics used as adjuncts to control symptoms.
African Americans may respond differently than whites to some of these drugs (Table 1). However, these findings should be interpreted with caution, since most of them came from subgroup analyses of trials in which African Americans accounted for as many as 28% to as few as 1%.50 To date, no data unequivocally show that we should use standard heart failure therapies any differently in African Americans than in whites.
Digoxin: Limited role to control symptoms
Post hoc analysis of the Digitalis Investigation Group trial, in which 14% of the patients were nonwhite, revealed that compared with placebo, digitalis (and achieving a serum digitalis concentration of 0.5 to 0.9 ng/mL) was associated with lower rates of all-cause mortality in most subgroups—except nonwhites.51
In general, digoxin has a limited role in heart failure, since other drugs are available that substantially modify outcomes. However, it can be considered in patients who have persistent heart failure symptoms.
ACE inhibitors, ARBs are recommended
ACE inhibitors are recommended for patients with New York Heart Association (NYHA) class I, II, III, or IV heart failure (class I recommendation, ie, “recommended”; level of evidence A on a scale of A, B, and C) and as part of standard therapy for African American patients with heart failure with symptomatic or asymptomatic left ventricular systolic dysfunction (class I recommendation; level of evidence C).41
Although African American patients did not appear to derive any benefit from enalapril (Vasotec) in the Studies of Left Ventricular Dysfunction (SOLVD) trial,52 a subsequent analysis that involved the SOLVD Prevention Trial did not find any differences between African Americans and whites in response to this agent.6 Similarly, a meta-analysis did not suggest differences in ACE-inhibitor efficacy in reducing adverse cardiovascular outcomes in heart failure between African Americans and non–African Americans.53
Of note: African Americans have a 3% to 4% higher incidence of angioedema from ACE inhibitors than whites.54,55
Angiotensin receptor blockers (ARBs) can be used as substitute therapy in African Americans who cannot tolerate ACE inhibitors (class IIa recommendation, ie, “reasonable”; level of evidence B).41
Beta-blockers also recommended
Beta-blockers are recommended in NYHA class I, II, III, and IV heart failure (class I recommendation; level of evidence A) and as part of standard therapy for African Americans with heart failure due to symptomatic left ventricular systolic dysfunction (class I recommendation; level of evidence B) and asymptomatic left ventricular systolic dysfunction (level of evidence C).41
Carvedilol (Coreg) and metoprolol (Lopressor) are the standard beta-blockers used to treat heart failure, and these drugs should be used in African Americans as well as in whites.15,53,56–59 Of interest, however, race-specific differences may exist in the beta-adrenergic pathway.60,61
Aldosterone antagonists: More study needed
Aldosterone antagonists, also called mineralocorticoid antagonists, ie, spironolactone (Aldactone) and eplerenone (Inspra), are recommended in addition to beta-blockers and ACE inhibitors for NYHA class II–IV heart failure, unless contraindicated (class I recommendation; level of evidence A).
However, trials of aldosterone antagonists to date have enrolled few African Americans.62–64 The limited data suggest that African Americans with heart failure may be less responsive to the renal effects of spironolactone, demonstrating less of an increase in serum potassium levels, and there are essentially no data to guide the use of these drugs in African Americans with heart failure.65 Further study is needed. But in the absence of data to the contrary, these agents, should also be used in African American patients with class III or IV heart failure.
