Eliminating Cardiovascular Health Disparities in African Americans: Are We Any Closer to Closing the Gap?

The release of Healthy People 2010 and the landmark Institute of Medicine report brought our attention to the importance of health disparities almost two decades ago.^1,2 Despite improvements in our overall care of patients with cardiovascular disease (CVD), rates of CVD in African Americans have continued to remain higher than for other groups. For instance, the overall rates of death attributable to CVD in 2013 were 356.7 for non-Hispanic African American men, 270.6 for non-Hispanic white men, 197.4 for Hispanic men, 246.6 for non-Hispanic African American women, 183.8 for non-Hispanic white women, and 136.4 for Hispanic women.³ Moreover, the gap in life expectancy between African Americans and whites is driven primarily by excess CVD mortality in African Americans.⁴

So, almost two decades after the importance of race/ethnic health disparities was brought to our attention, are we any closer to closing the gap? The AHA has put forth a scientific statement describing the current state of Cardiovascular Health in African Americans.⁵ The writing group has reminded us that we have a long way to go before we reach the ultimate goal of providing equitable care in a healthcare system that results in equitable health outcomes for all groups, regardless of race/ethnicity. The statement highlights the exquisite complexity of the issues that impact the persistence of health disparities, ranging from genetics, to risk factor burden, to social determinants of health that affect lifestyle and health behaviors, and even treatment effectiveness. Specifically:

Determinants of differences in disease burden. There is no denying that the strongest contributor to excess CVD in AA is the excess of CVD risk factors, particularly hypertension. The writing group reminds us that unique genetic polymorphisms may be present in African Americans that contribute to earlier disease onset, as well as a more severe phenotype. However, a recent systemic review suggests that the small number of GWAS with substantial populations of African ancestry has limited our ability to detect genetic factors that contribute to CVD disparities between African Americans and whites.⁶ Even if genetic variants affect population differences in disease incidence and prevalence, African Americans may suffer from a “two-hit” phenomenon where genetic susceptibility to certain disease states is amplified by environmental and contextual factors that worsen clinical outcomes.

Contextual factors that influence disease outcomes. The writing group accurately reminds us that African American race in the United States (U.S.) is closely correlated with socioeconomic status – lower income, education, and health literacy, as well as less access to preventive strategies. Similarly, a history of economic and political policies that have prevented African Americans from having equal access to economic affluence has shaped cultural practices that linger today (i.e., dietary choices, fear and mistrust of the healthcare system, etc.). It is important for healthcare providers to take all of these factors into account in the office setting. Patients are often labeled “difficult” or “noncompliant” for not adhering to medical recommendations; however, patients’ socioeconomic struggles are real barriers that often are not discussed in the clinical setting, but certainly impact clinical outcomes.

Determinants of differences in response to treatment for disease. Race-specific guidelines for treatment have been issued for conditions including hypertension as well as heart failure. A recent analysis of NHANES data confirms that African American patients are more likely to be treated with anti-hypertensive medications with proven efficacy in African Americans, including diuretics and calcium channel blockers⁷ consistent with recommended guidelines⁸. Despite being more likely to receive the recommended therapy, as well as combination therapy with two or more drugs, African American patients were 27% less likely to achieve hypertension control, consistent with the notion that African Americans have more aggressive forms of hypertension. Inadequate treatment of hypertension strongly contributes to the high rates of end-organ disease in this group, including heart failure (HF), chronic kidney disease, and stroke. Prior analyses suggest that >30% of incident HF in African Americans could be prevented by eliminating hypertension as a risk factor.⁹ Thus, many groups advocate that more aggressive SBP control targets may be reasonable in higher risk individuals.^{10, 11}

The information provided in this report is extremely timely as the demographics of the U.S. population shifts towards a more diverse society. It is impossible to dissociate health outcomes for African Americans from the larger social and political climate that created these inequities to begin with. The writing group reminds us of studies that show the health consequences of perceived racial discrimination. Recent events, including high profile cases of police brutality, the rise of white supremacist groups as we saw in Charlottesville Virginia, and the repeal of political legislation intended to erase historical social injustices, reminds us that even today, discrimination is not always perceived and is often very real. Many of the historical forces that kept African Americans in a socioeconomically disadvantaged position persist to date and continue to have both direct and indirect impacts on the health outcomes of this group. As such, it is increasingly important for the healthcare community to keep equity at the forefront of our awareness in an effort to advocate for issues that impact all of our patients – particularly those who are most vulnerable and most disenfranchised.

Finally, while African Americans are overrepresented in the prevalence of conditions such as HF and stroke, they are grossly underrepresented in the clinical trials used to determine treatment for said conditions. The enrollment of African Americans in contemporary clinical trials for HF and stroke has been dismal and does not match the burden of disease. The NIH has made it mandatory to include women and minorities as participants in research involving human subjects. However, no such requirement exists for the pharmaceutical industry. Moreover, large and costly trials are often performed without adequate numbers of minority patients, such that conclusions regarding the effectiveness of new medications in the populations who have the most potential to benefit are based on post-hoc analyses. African Americans’ low participation in clinical trials may in part be patient-driven due to mistrust of the healthcare system related to past medical experimentation on poor African Americans. However, this phenomenon may also in part be provider-driven. Studies have shown African Americans are less likely to be recruited into clinical trials because physicians are less likely to take the time to discuss new and alternative therapies¹² and are more likely to perceive African Americans as likely to be ineligible or to be noncompliant.¹³ Regardless of the reasons, African Americans should be strongly encouraged to participate in clinical trials for disease states that disproportionately affect them.

The causes for the existence of health disparities are multifactorial, and “rooted in historic and contemporary inequities”.¹ Accordingly, the solutions for the elimination of health disparities will have to be multifactorial as well. The gap can only be closed with concerted efforts to increase knowledge of determinants of differences in disease burden, response to treatment of disease, and eliminate disparate contextual factors that influence clinical outcomes once disease is manifest. The healthcare community must continue to encourage research initiatives, quality metrics, clinical trial enrolment, reporting of results, and patient education and engagement that is sensitive to race and ethnic differences in manifestations of CVD.