ACC 2017: No racial differences in dual antiplatelet therapy use after percutaneous coronary intervention

March 17, 2017 – Black and white patients had similar rates of dual antiplatelet therapy utilization and adjusted cardiovascular outcomes three years after percutaneous coronary intervention.

A recent study presented at this year’s Scientific Sessions of the American College of Cardiology (ACC) in Washington, D.C. found that while black drug-eluting stent (DES) recipients were younger, had more diabetes, hypertension, and renal disease as compared to white patients, they had similar rates of dual antiplatelet therapy (DAPT) utilization through their first year post-percutaneous coronary intervention (PCI).

“Finding that DAPT use didn’t vary significantly by race is very important,” said Lonnie Sullivan, a medical student at Duke University and first author of the study (pictured). “It verifies that there is no race-driven difference in the care these patients are receiving.”

DCRI and Duke researchers observed data from 915 black and 3,559 white patients who underwent DES placement at Duke University Medical Center between 2005 and 2013. Longitudinally observing patients who received care at Duke for the past several decades, the researchers compared DAPT use at hospital discharge and at follow-up at six months, 12 months, and annually thereafter. Logistic regression was used to model the effects of DAPT use on clinical outcomes post-PCI.

“Premature discontinuation of DAPT may result in stent closure,” Sullivan said. “With this study, we wanted to determine if there was any difference in how DAPT was utilized by race and if this in part explained potential differences in outcomes.”

The study found that black patients who received DES had worse unadjusted cardiovascular outcomes compared to white patients despite the fact that at discharge, there were no notable racial differences in the utilization of DAPT. There were similar rates of revascularization however, as compared to white patients at 36 months. These differences dissipated after adjustment for baseline characteristics.

According to Sullivan, the question still remains as to why black patients receiving DES have more comorbidity at baseline than white patients.

“What we do know is that there are more barriers involved for black patients in receiving care,” he said.

The study also specifically looked at DAPT utilization but researchers were unable to assess adherence beyond self-report, thus there was no definitive way of determining whether patients had missed doses.

“Educating patients on the importance of compliance as soon as they are started on DAPT is one of the most important interventions that we can implement,” Sullivan said. “Being able to adequately control existing cardiovascular risk factors will also go a long way in improving outcomes.”

In addition to Sullivan, other researchers included the DCRI’s Hillary Mulder, Karen Chiswell, Linda Shaw, Tracy Wang and Kevin Thomas.