From Excess Amputations to Postpregnancy HF, Studies Shine Light on Racial Divide

In 2020, the American Heart Association highlighted structural racism as a driver of health disparities and called for more detailed research. Now, in a special issue of the Journal of the American Heart Association, 16 studies highlight CV health disparities in diverse populations ranging from PAD and heart transplantation to trial enrollment challenges, among others.

Senior associate editor Pamela Peterson, MD, MSPH (Denver Health Medical Center, CO), and associate editor Sula Mazimba, MD, MPH (University of Virginia Medical Center, Charlottesville), say the burden of CVD in Black communities “remains disproportionately high and is a primary cause of disparities in life expectancy between Black and white individuals.” Epidemiologic data suggest that CVD outcome disparities account for about 30% of the difference in mortality between Black and white males and 40% of the difference between Black and white females,” they add.

“It's important to have a broad picture looking at social determinants of health and how structural racism may play a role,” Peterson told TCTMD. “One thing that I would say about most of these studies is that none of them gives us a firm answer. I think what they do is continue to highlight the need for further research, and to explore to what extent are there biologic reasons, or to what extent are there social determinants of health and other factors, that are playing into these disparities.”

Snapshots in a Broader Picture

In one study, led by Alexander C. Fanaroff, MD, MHS (Perelman Center for Advanced Medicine, Philadelphia, PA), markers of lower socioeconomic status and Black race were associated with higher rates of major lower-extremity amputation in patients with PAD. Nearly four in five Americans who underwent amputation lived in metropolitan areas. Fanaroff and colleagues say strategies are needed to target communities with high amputation rates and to address racial residential segregation in urban neighborhoods that affects access to care. They concluded that solutions may include “investment in the development and implementation of scalable community‐based resources for PAD diagnosis and management—potentially including community screening programs, reliable oscillometric ankle-brachial index screening techniques, home‐based walking programs, and collaborative efforts to measure and improve the quality of medical management of patients with PAD seen in primary care practices.” An in-depth feature story by TCTMD has previously detailed some of the novel approaches being pioneered to reach at-risk groups.

Access to high-quality healthcare resources as a driver of underlying healthcare disparities also was seen in a study of adult heart transplant recipients. Compared with white patients, those who were Black were less likely to undergo transplantation (adjusted HR 0.87; 95% CI 0.84-0.90) but were at greater risk of post‐transplant death (HR 1.14; 95% CI 1.04-1.24), despite an increase in Black and Hispanic patients enrolled on transplant wait lists over the study period.

In another study, heart failure (HF) within 5 years of pregnancy was increased in women with pre‐pregnancy hypertension and hypertensive disorders of pregnancy (HDP), but the risks were substantially higher for non-Hispanic Black women compared with white women (2.28 compared with 0.96 per 1,000 person‐years). The investigators, led by Angela M. Malek, PhD (Medical University of South Carolina, Charleston), say more data are needed on racial/ethnic differences in maternal incident HF after delivery “with consideration of pre‐pregnancy hypertension and/or HDP, and in particular the individual components of HDP as well as severity.” They added that differentiation between HF with preserved versus reduced ejection fraction and “development of a prediction model to predict the risk of adverse maternal outcomes subsequent to delivery in women with and without HDP or pre‐pregnancy hypertension is of interest and could help guide intensified follow‐up.”

Other studies in the special issue focus on racial and sex differences in anticoagulation after electrical cardioversion for atrial fibrillation and flutter, disparate outcomes after MI in younger patients, differences in disease expression in hypertrophic cardiomyopathy, out-of-hospital cardiac arrest, white matter structure and amyloid deposition, and health disparities among women of childbearing age.

Missing from Clinical Trials

Peterson said one of the included topics that she would like to see more discussion on involved the enrollment of underrepresented minorities in clinical trials, adding that it has “been an ongoing challenge for many trials in many ways.”

The study to which she referred reviewed National Institutes of Health‐funded CV clinical trials registered on ClinicalTrials.gov between 2000 and 2019. Only one trial out of 100 that were included in the review reported meeting its enrollment goal of a specified recruitment target for minority groups.

“The majority of these trials did not specify a Black enrollment target, did not meet targets, and largely did not report plans to enroll Black adults in their studies,” the authors reported. They add that “the first step is for Black inclusion to be a priority at the trial-design phase through defined recruitment targets and intentional recruitment strategies.” In an accompanying editorial, Neal K. Lakdawala, MD (Brigham and Women's Hospital, Boston, MA), suggests that funding agencies and regulators “should monitor diversity prospectively and actively incentivize investigators to enroll Black patients.”

Peterson said all of the studies highlight the fact that much work remains to be done, both in identifying why disparities exist and addressing the factors responsible for them.

“For a long time, there's been a lot of research out there that just sort of demonstrates the existence of health disparities,” she said. “The reality is that we have a long way to go to address the problem.”