Inequities in Mitral, Tricuspid Trials Have Implications Across CV Research

(UPDATED) Hospitals that participate in clinical trials for transcatheter mitral and tricuspid therapies care for a more socioeconomically advantaged population than those that don’t take part, although their proportions of Black and Hispanic patients are similar, according to new data.

The findings, researchers say, should inform policies around clinical trial recruitment and conduct to bring about greater inclusivity in trial results across the spectrum of structural heart, cardiology, and even, more broadly, general medical research.

There are a few different tacks to take depending on what kind of increased diversity is the priority, lead author Ashwin S. Nathan, MD (University of Pennsylvania, Philadelphia), told TCTMD. “If you want to improve representation among poorer patients and socioeconomically disadvantaged patients, I think there is some utility to expand site selection to include those hospitals that serve poorer communities,” he said. “But if you want to expand access to Black and Hispanic patients and otherwise minority patients, it is actually the very same patients that are within the hospital [where] you are having these trials, and increased efforts for outreach may be what is necessary.”

The study, published online last week ahead of print in JAMA Cardiology, is not the first to identify inequities within clinical trial enrollment, but by focusing on just the tricuspid and mitral valvular space, the researchers were able to identify “one slice of probably a much larger problem,” Nathan said. “This gets at a much bigger problem within not only cardiology, but medicine overall into how we think about trial diversity.”

Commenting on the findings for TCTMD, Ourania Preventza, MD (Baylor College of Medicine, Dallas, TX), agreed. “[Trials] need to be patient specific,” she said. “And if you do not have patient-specific studies, you cannot really treat patients well. So, the implications can be huge [if] your results do not reflect the population that we treat.”

Her previous research looking at sex discrepancies of both patients in and physicians leading cardiovascular surgery trials found vast underrepresentation of females in both these categories, so Preventza also stressed the importance of including more women in trials in general.

Differences in Trial Hospitals

For the study, Nathan and colleagues used Medicare data from 2019 to identify 1,050 US hospitals with active cardiac surgery programs, including 121 (11.5%) that participated in 32 unique trials for transcatheter mitral or tricuspid therapies.

Hospitals that participated in trials were generally larger and more likely to be academic centers and located in metropolitan areas. Also, those undergoing procedures at trial hospitals had a greater comorbidity burden.

This gets at a much bigger problem within not only cardiology, but medicine overall into how we think about trial diversity. Ashwin S. Nathan

Compared with patients treated at hospitals that did not participate in trials, those treated at trial hospitals had a $5,291 higher median zip code-based household income and a 5.37 lower Distressed Communities Index score in adjusted models. There was no significant difference in the proportion of patients dual eligible for Medicaid.

The difference in proportion of Black and Hispanic patients treated at each category of hospitals was less than 1% after adjustment for each of the socioeconomic indicators.

While Nathan said he is doesn’t know why these patterns have emerged, it’s clear that maintaining a clinical trial infrastructure is expensive. “I know hospitals that take care of poorer patients tend to operate on thinner margins, and it is certainly more difficult for them to participate in trials,” he said. “That definitely can contribute to hospitals taking care of poorer patients not having access to the trials.”

As for racial and ethnic inequities among hospitals that do participate in trials, Nathan pointed out that they are already “enriched with Black and Hispanic patients, but they are still not enrolling those patients. I think that has to do with building trust in those communities and then improving outreach to those populations within those hospitals that actually have trials.”

The Quest for Equity

In an accompanying editorial, Ann Marie Navar, MD, PhD (University of Texas Southwestern Medical Center, Dallas), agrees. “Improving racial and ethnic diversity in clinical trials will require multifactorial interventions within participating sites to ensure that patients are being equitably identified and offered clinical trials, remove barriers to trial participation, and improve outreach and build trust in research among Black and Hispanic individuals.”

More strikingly, the findings “highlight an even more important barrier to diversity in clinical trial participation in patients with valvular disease: disparities in identification and referral for valve intervention in the first place,” Navar writes. She notes that fewer than 5% of patients undergoing cardiac surgery or TAVR at all hospitals were Black and Hispanic, a number far below what would be expected given the demographics of the US.

“Ultimately, without efforts to address these disparities in diagnosis and treatment for valvular heart disease, even with improved enrollment of Black and Hispanic persons, access to clinical trials will never truly be equitable,” Navar concludes.

All of these issues need to be “proactively thought about” when trials are designed going forward, Nathan said. “The foresight to try to improve inclusivity at that stage is what will help us ultimately improve the diversity of these clinical trials. If we rely on the same sites, I think we are going to continue to get the same results. If we can think about it ahead of time and think about setting recruitment goals and improvement targets, I do think that this is a this is a very fixable problem.”

Moreover, he pointed out, this presents an ideal opportunity for collaboration among government agencies, clinicians and hospitals, and industry. “I think there can be a really nice synergy between all three groups in order to address this problem,” he said.

Preventza added that mandates from the National Institutes of Health and Food and Drug Administration about inclusivity in trials might also go a long way toward increasing diversity in research that will ultimately lead to more applicable findings for a wider variety of patients.

Whether industry-funded trials that don’t fall under these mandates opt to make the same changes remains to be seen.