Racial, Ethnic, and Socioeconomic Disparities in P2Y12 Inhibitor Prescribing Following PCI in Medicare Beneficiaries

Background: Dual antiplatelet therapy is the standard treatment for patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). Research has shown that ticagrelor and prasugrel are more effective in reducing ischemic events when compared to clopidogrel but may be associated with increased bleeding. Patients initiated on ticagrelor or prasugrel may be deescalated to clopidogrel whereas patients who were pretreated with clopidogrel may be escalated to prasugrel or ticagrelor due to clinician discretion. There is a lack of data exploring P2Y12 inhibitor prescribing and switching trends by racial, ethnic, and social factors.

Objectives: To identify racial, ethnic, and socioeconomic disparities in P2Y12 inhibitor prescribing trends in patients with ACS following PCI.

Methods: This was a retrospective cohort study that used Medicare data from 2010 to 2019 to identify patients who underwent PCI for ACS. The initiation of P2Y12 inhibitors along with the rates of therapeutic escalation and deescalation was assessed across racial and ethnic subgroups. The Social Vulnerability Index (SVI) was used to assess the county-level social determinant of health status. P2Y12 inhibitor prescriptions for Black and Hispanic patients were compared to White patients via minimally adjusted and fully adjusted logistic regression models.

Results: A total of 250,601 participants met the eligibility criteria. The mean (SD) age of patients was 76.0 (6.9) years; 41.9% of patients were female. After adjusting for patients’ characteristics, including baseline comorbid conditions, geographic regions, bleeding risk factors, and SVI themes, both Black and Hispanic patients were 14% (OR 0.86 [95% CI, 0.82-0.89]) and 5% (OR 0.95 [95% CI, 0.91-0.99]) less likely to be initiated on ticagrelor or prasugrel, respectively. Black patients were 13% less likely to undergo therapeutic escalation (OR 0.87 [95% CI, 0.76, 0.98]) compared to White patients, while also being 25% less likely to be therapeutically de-escalated (OR 0.75 [95% CI, 0.70, 0.80]). SVI was not a significant determinant of initial P2Y12 inhibitor choice or escalation or de-escalation of therapy.

Conclusions: Racial disparities were most evident for Black and Hispanic patients regarding P2Y12 prescribing trends. These disparities were not evident based on socioeconomic status. Identifying and evaluating the mediators for disparities is essential to improving post-PCI treatment for patients with ACS.