No Racial Disparity in Post-PCI Mortality Seen at the VA

There does not appear to be a major disparity in post-PCI outcomes between black and white patients treated within the US Veterans Affairs (VA) system, a new analysis shows, in contrast to some prior research suggesting that black patients fare worse.

After accounting for differences in baseline characteristics, black patients were not more likely to die within the first year (OR 1.04; 95% CI 0.90-1.19), according to lead author Taisei Kobayashi, MD (Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA), and colleagues.

The lack of difference was consistent for nearly all outcomes examined, with the exception of acute kidney injury, which was more commonly seen in black patients in the first 30 days (OR 1.22; 95% CI 1.10-1.36), the researchers report in a study published online today ahead of print in JAMA Cardiology.

Speaking with TCTMD, senior author Jay Giri, MD (Corporal Michael J. Crescenz VA Medical Center and the University of Pennsylvania), noted the discrepancy between the unadjusted and adjusted outcomes. Before accounting for baseline differences, black patients had higher rates of mortality, acute kidney injury, blood transfusion, and readmission for MI. Nearly all of those differences disappeared after adjustment for comorbidities and presentation (black patients were more likely to present with ACS).

Thus, once patients got to the cath lab, “it looked like the outcomes were equitable among black and white patients,” Giri said.

“So what we’re seeing is that when we’re trying to address health equity . . . in these patients, at least in the VA, it seems like the conversation probably shouldn’t be starting at the cath lab door,” he said. “It has to move backwards towards primary prevention and secondary prevention efforts, which are not being delivered equivalently among [black and white patients] if there’s still persistent discrepancies in their risk factors.”

The conversation probably shouldn’t be starting at the cath lab door. It has to move backwards towards primary prevention and secondary prevention efforts, which are not being delivered equivalently. Jay Giri

Wayne Batchelor, MD (Southern Medical Group, Tallahassee, FL), said the study is an important contribution to the literature dealing with the impact of race on clinical outcomes. But “the results are not too surprising given the fact that, historically, race has exerted its effect on clinical outcomes through a range of clinical, angiographic, social, and economic factors,” he told TCTMD.

By examining a cohort primarily consisting of men with similar healthcare access, “this study misses out on the opportunity to understand gender effects on outcome and also attenuates the traditional impact of race through differences in healthcare access and quality, socioeconomics, and a number of treatment biases,” he continued. “Therefore, one can only conclude that when many of the typical confounders that accompany race are removed, race itself does not appear to have much of an independent effect on outcome.”

Black Patients Less Likely to Receive DES, Beta-Blockers

Prior research has revealed racial disparities in terms of quality of care and outcomes in patients with CAD. A large study of Medicare beneficiaries, for example, showed that black patients were more likely than white patients to die after PCI. However, it was unclear whether similar differences existed within the integrated VA health system.

Giri said this study, which included 42,391 patients (13.3% black; 98.4% men) treated at 63 VA hospitals between October 2007 and September 2013, was initially designed as the first step of a quality improvement initiative. Data came from the VA Clinical Assessment, Reporting, and Tracking System for Cardiac Catheterization Laboratories (CART-CL) program. The expectation was that black patients would have worse outcomes and that certain factors that could be targeted to address the disparity would be identified.

Thus, Giri said the researchers were “pleasantly surprised” to find that most outcomes did not differ between black and white patients.

Although the lack of a racial disparity in mortality in this study could be due to the smaller sample size when compared with the prior Medicare analysis, Giri pointed out that there are several distinctive characteristics of the VA system that might influence outcomes.

It is an integrated system that includes all outpatient, inpatient, and pharmacy services, providing less fragmented care, he explained. In addition, prescriptions are mailed directly to patients after discharge, simplifying the process of obtaining required medications. And finally, VA physicians are primarily salaried, perhaps making medical decision making freer of financial considerations.

Although most outcomes were similar regardless of race, there were a few differences in terms of treatment approaches: black patients were more likely to receive BMS instead of DES and less likely to receive postprocedural beta-blockers.

Batchelor noted that prior studies have shown that black patients are less likely to receive DES, and indicated that that could be due to differences in perception by physicians about patients’ ability to adhere to dual antiplatelet therapy (DAPT). For patients who are deemed unlikely to stick to their regimen, physicians are more likely to choose BMS.

“That could’ve been playing a role here, although I would think in the VA that would be less of an issue than in the real world, where there’s a higher rate of lack of healthcare insurance in minorities than in, for example, white men.”

Giri also pointed to potential differences by race in physician perception of a patient’s likelihood to keep taking DAPT. “It’s kind of the most obvious explanation,” he said.

As for the discrepancy in beta-blocker use, Giri and Batchelor agreed that it likely had to do with evidence showing that the agents are less effective as antihypertensive medications in black versus white patients. Black patients are therefore more likely to be prescribed calcium channel blockers and diuretics to control blood pressure, Batchelor said.

More Representative Clinical Trial Populations Needed

Batchelor called the primary finding of the study—a lack of mortality difference—reassuring, but said the suggestion of racial bias in decision-making around stent choice is “something that has to be addressed and something the physicians have to look at very carefully.”

He also pointed out that the external validity of the study is limited because of the unique characteristics of the VA system.

“Further studies into the impact of race and gender on clinical outcomes that take into account variances in healthcare access, socioeconomic status, treatment biases, and patient compliance are still warranted,” he said.

Batchelor added that the medical and research communities need to increase efforts to collect data relevant to all groups of patients, including women and those from racial and ethnic minorities. “Moving forward as we do randomized trials on new therapies, we have to . . . do a better job of making sure that the patient population is representative of the US population. We’re not there yet,” he said. “If we had better upfront enrollment, we probably would have to do fewer post hoc analyses like this to try to make sense of how race impacts outcome.”