African-American ACS Patients Less Often Treated With Prasugrel After PCI

Despite presenting at higher clinical risk, African-American patients treated with PCI for ACS are less likely to be given the potent antiplatelet agent prasugrel compared with non-African-American patients, according to results from the PROMETHEUS registry.

African-Americans have been underrepresented in clinical research, and this translates into open questions with regard to their healthcare, senior author Roxana Mehran, MD (Icahn School of Medicine at Mount Sinai, New York), told TCTMD.

“We really do have to understand if there is a racial disparity in receiving therapies that benefit patients with cardiovascular disease,” she said. If a gap does exist, “well, we need to erase that,” Mehran continued. “It needs to go away. I'm not suggesting that there is, but this registry is sort of a lens to what's going on in the real world.”

For the study, published online last week ahead of print in Catheterization and Cardiovascular Interventions, Michela Faggioni, MD (Icahn School of Medicine at Mount Sinai), Mehran, and colleagues looked at 19,832 patients—10.7% of whom self-identified as African-American—from the PROMETHEUS registry who received PCI for ACS at eight US centers between 2010 and 2013. African-American patients were younger, more often female, and more likely to have a history of diabetes, chronic kidney disease, or prior PCI than non-African-Americans.

Prasugrel, which is now available as a generic but was not during the study period, was more often prescribed in non-African-American versus African-American patients (21.4% vs 11.9%; P < 0.01). In fact, African-American race was identified as an independent predictor of reduced prasugrel use on multivariable analysis (P < 0.0001).

Prasugrel prescriptions increased by severity of clinical presentation in non-African-American patients (P < 0.001), but not in African-Americans. Also, use of prasugrel went down with both increased ischemic and bleeding risks for all patients, but more so for non-African-American patients.

In multivariable analysis, MACE (the composite of all-cause death, non-fatal MI, stroke, or unplanned coronary revascularization) and bleeding risk at 90 days were similar for all patients regardless of race. However, the adjusted risk of MI was higher for African-American patients at both 90 days (HR 1.62; 95% CI 1.30-2.02) and 1 year.

‘A Call to Action’

While the results of this study are not surprising, they are “concerning,” Wayne Batchelor, MD (Southern Medical Group, Tallahassee, FL), told TCTMD.

“We've seen from other observational studies that there seems to be a bias such that African-Americans are less likely to be treated with aggressive antiplatelet therapies relative to other racial groups, so this is not the first study to report that,” he commented. “I think it was a very insightful and helpful study because it highlights the importance of teasing out the independent factors that lead to these biases, and I think it's a call to action for us to figure out why this might be.”

The challenge moving forward lies in the interpretation of these data. “At the end of the day, the decision to put a patient on a particular antiplatelet agent rests on the interaction between the physician and the patient [and] is also influenced by healthcare insurance and socioeconomic status,” Batchelor continued. “So if there's a perception, or the patient relates to the physician, that they won't be able to afford the newer agents like prasugrel or ticagrelor, then obviously there is going to be a bias toward treating those patients with the generic clopidogrel. So I'm almost certain that there's some part of that playing out in this study.”

Everything is moving in the wrong direction here. I think that's a really compelling reason to do further study. Wayne Batchelor

Now that prasugrel is available generically, “this bias should be perhaps reduced over time, and the hope is that it will be,” Batchelor said. “If it's purely a cost issue, then the bias should go in the right direction and be eliminated. If there are other elements that determine that ultimate decision that relate to the patient/physician interaction, then obviously that bias could still persist.”

In the current era, Mehran said she would like to see physicians “paying a lot of attention to not just a patient's lesion but also the entire patient risk profile—thinking about all of their cardiovascular risk and making sure we're applying the best medical management of these patients along with the best revascularization strategies.”

Future researchers should make every effort to include more African-American patients in their studies, she stressed. “We have to work hard in doing specific studies that only enroll minority patients, . . . and I think we need to push industry and NIH and others to [fund] those studies for women and minorities. I really believe we have to do that. Otherwise we're constantly missing evidence.”

Batchelor also argued the need for more inclusive research. “I'd love to see a study that looks at the intersection between race, ethnicity, gender, insurance status, and socioeconomic status and other social determinants of health to really tease out [if] race just simply a surrogate for healthcare insurance status or something else,” he said. “Are there other factors that account for these differences in prescription use and also in outcomes?”

Given that this study found a higher risk of MI among African-American patients, “you get this really strange paradox, where they present with higher risk but prescription use is less than 50% what it is in non-African-Americans and their outcomes are far worse,” he said. “So everything is moving in the wrong direction here. I think that's a really compelling reason to do further study.”

Note: Mehran is a faculty member of the Cardiovascular Research Foundation, the publisher of TCTMD.