Even in Big Cities, There Are Barriers to TAVI Access

Even in metropolitan areas where access to TAVI shouldn’t be a problem, geographically speaking, there’s still evidence of racial/ethnic and socioeconomic disparities when it comes to treatment of aortic stenosis, according to an analysis of data on Medicare beneficiaries.

Lead author Ashwin S. Nathan, MD (Hospital of the University of Pennsylvania, Philadelphia), said the current study, published online today in JAMA Cardiology, is complementary to his group’s earlier report on the urban versus rural divide in the proliferation of new TAVI centers.

With this analysis, he told TCTMD, they sought to see at a “more-granular level” what was happening in cities. The point was to do a deep dive “into the local regions and [try] to understand who is and who is not getting access to this procedure even though it’s sort of ‘in their backyard,’” Nathan explained.

Their research isn’t the first to look at where TAVI programs are and which regions they serve. What’s less understood, said Nathan, are the demographic characteristics of the patients themselves.

“When you take out that factor of geographic access, are there still inequities in who has access to the procedure? And the answer is: yes,” Nathan emphasized. “Above and beyond [physical proximity] there are racial/ethnic and socioeconomic inequities in access to TAVI.”

Signs of Systemic Barriers

Nathan and colleagues conducted their analysis by using Medicare claims data from 2012 through 2018, including fee-for-service beneficiaries ages 66 and up who lived in the 25 largest metropolitan core-based statistical areas. The numbers were crunched at a zip code level using US Department of Housing data. The metropolitan areas studied had, on average, seven TAVI centers.

They assessed 7,590 individual zip codes, where Medicare beneficiaries had a mean age of 71.4 years. Slightly less than half (47.6%) were men, while 4.0% were Asian, 11.1% Black, 8.0% Hispanic, and 73.8% white.

Per 100,000 beneficiaries, the mean number of TAVI cases was 249. With each $1,000 decrease in household income, this number dropped by 0.2%. Unadjusted TAVI rates per 100,000 were lower for Black and Hispanic patients compared with white individuals irrespective of median household income. For instance, even in the highest income tertile, there were 154 TAVIs for Black, 194 for Hispanic, and 451 for white patients per 100,000 beneficiaries.

Adjusted for age and comorbidities, the higher the percentage of patients who were dually eligible for both Medicare and Medicaid, the lower the TAVI prevalence; the same inverse relationship was seen for Distressed Communities Index score, which captures economic indicators including education, housing vacancy, unemployment, poverty rate, median income, and changes in employment/business establishments at a zip code level.

Further adjusted for median household income, the data also showed that for every 1% increase in the proportion of Black patients within a zip code, the number TAVIs performed dropped by 1.1% (P< 0.001). As the proportion of Hispanic patients rose by 1%, TAVIs decreased by 1.2% per 100,000 beneficiaries (P = 0.03). There was no interaction between race/ethnicity and income level. Sensitivity analysis showed similar results for SAVR alone or all aortic valve replacement (surgical and transcatheter).

“While it is unclear whether this reflects different burdens of symptomatic aortic stenosis by race and socioeconomic status or disparities in use of TAVR, these findings may suggest that access to high-technology therapeutics [requires] more than geographic proximity and adequate health insurance and systemic barriers can limit the receipt of high-technology healthcare by marginalized populations,” the investigators conclude.

In turn, they add, “disparate availability of a technology may contribute to the presence of structural racism within medicine, which is defined as macrolevel systems, societal forces, institutions, ideologies, and processes that generate and reinforce inequities among racial and ethnic groups.”

Both TAVI and SAVR, said Nathan, “are very sophisticated procedures that require a lot of patient investment to get the procedure done.” There’s preoperative testing as well as multiple clinic visits, on top of the hospital stay itself and the recovery period.

“It’s hard for certain groups of patients to make that investment,” he commented.

Cardiologists have a role to play in addressing these inequities, Nathan said. “We do have the due diligence to understand what the issue is and try to address it.” Obstacles can occur at many steps along the process. Patients may lack access to primary care or not receive an initial echocardiogram, or they may not be referred to a specialist, for instance. For some, the cost of commuting to the hospital or missing work is prohibitive.

“All these things are hard for patients, and we have to try to identify ways to make them easier,” he advised. Possible solutions include patient navigators to help guide people through the intricacies of obtaining treatment for their aortic stenosis, or even something as simple as transportation vouchers.

‘Disentangling Race’ a Daunting Task

One important missing ingredient in understanding these patterns, though, is knowledge about the biology of aortic stenosis as it relates to ancestry, Nathan et al acknowledge.

Clyde W. Yancy, MD (Northwestern University Feinberg School of Medicine, Chicago, IL), and Ajay Kirtane, MD (NewYork-Presbyterian/Columbia University Irving Medical Center, New York, NY), agree that TAVI’s rollout “appears to mirror past patterns of race-based disparities,” asking in an editor’s note, “Has there been no real progress?”

In interpreting the current results, they write, “we echo the caution of residual unmeasured confounders; restate concerns regarding the biology of calcific aortic stenosis as a function of genetic ancestry; and add survival bias given the shorter life expectancy as a function of race.”

What’s clear is that “disentangling race from the entirety of the social construct is a complex and uncertain exercise,” Yancy and Kirtane say. “Is it possible that there are race-based biases impacting TAVR at the patient level? Yes. Is it proven? No. Equity in access to care and completeness of clinical assessment, including even a careful physical examination, also come into play when assessing disparities in a ‘downstream’ procedure such as TAVR.”

They posit that race isn’t the sole culprit. But as the evidence base builds to address this issue, “we must do more to recognize our possible biases and concomitantly exercise caution before concluding race-based disparities in the utilization of TAVR. We can be empathic but we must also be sure,” the editorialists stress.

For Nathan, what should come next are studies that, rather than analyzing large data sets, instead seek out the patient experience. “Talking to individual patients, understanding their barriers [and] limitations, I think would be the most helpful thing, . . . and then developing solutions and testing the solutions to make sure they help alleviate the problems are the next steps for this project,” he said.