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.
Heart transplantation: Poorer outcomes in African Americans?
Heart transplantation remains the most effective and durable therapy for advanced heart failure. Median survival approaches 14 years.82
However, a retrospective study found that African American recipients had an 11.5% lower 10-year survival rate than whites, which persisted after adjusting for risk, donor-recipient matching by race, and censoring of deaths in the first year.83 Although socioeconomic factors and poor human leukocyte antigen matching have been implicated, a retrospective cohort study showed that African American recipients had a higher risk of death than white recipients even after adjustment for recipient, transplant, and socioeconomic factors.84–87 African Americans were more likely to die of graft failure or of a cardiovascular cause than white patients, but were less likely to die of infection or malignancy. Although mortality rates decreased over time for all transplant recipients, the disparity in mortality rates between African Americans and whites remained essentially unchanged.84
Among all donor-recipient combinations, African American recipients of hearts from African American donors had the highest risk of death.88
Limited access to transplantation persists, particularly for African Americans of lower socioeconomic status. African Americans are more likely than whites to be uninsured, and the funding requirement to be placed on the transplantation list disproportionately affects African Americans.89,90
Left-ventricular assist devices
Left-ventricular assist devices (LVADs) improve survival in heart transplantation candidates and heart failure patients who do not qualify for transplantation. After LVAD implantation, African American patients have similar 1- and 2-year survival rates and no difference in readmission rates compared with whites.91,92
Access to LVAD implantation, however, is significantly influenced by race, and African Americans are significantly less likely to receive one (OR = 0.29).93 Further investigation is required to identify disparities in outcome, access, and contributing factors.
DISPARITIES CAN BE MINIMIZED
In general, heart failure in African Americans is characterized by a high prevalence of hypertension as a major risk factor and potentially different pathogenesis than in the general population. Furthermore, heart failure in African Americans is more prevalent, occurs at an early age, and has a more severe course than in whites, perhaps because of a higher prevalence of risk factors such as diabetes mellitus, obesity, and again, hypertension. These disparities are multifactorial and involve a complex interplay between genes, environment, and socioeconomic factors.
For now, heart failure in African Americans should be treated according to standard evidenced-based strategies, which include a combination of isosorbide dinitrate and hydralazine in addition to other neurohormonal modifying agents (ACE inhibitors, beta-blockers, aldosterone antagonists), a strategy demonstrated to reduce mortality rates in African Americans. When treated according to guidelines, disparities in outcomes can be minimized.
However, many questions about managing heart failure remain unanswered, since African Americans have been markedly underrepresented in clinical trials. Clinical trials need to enroll enough African Americans to answer the questions of interest. Disparities in outcomes must be investigated in a scientific and hypothesis-driven manner. The effect of the built environment on African Americans needs more study as well, as success with these strategies may be impeded by unrecognized factors.
Preventing heart failure should be a priority. Efforts should be directed toward detecting and modifying risk factors early, managing hypertension aggressively, and identifying left ventricular dysfunction early.
