Assessing the Clinical Treatment Dynamics of Antiplatelet Therapy Following Acute Coronary Syndrome and Percutaneous Coronary Intervention in the US

IMPORTANCE: A platelet ADP P2Y12 receptor (P2Y12) inhibitor plus aspirin is standard therapy for patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). Compared with clopidogrel, prasugrel and ticagrelor are associated with superior antiatherothrombotic effects but increased bleeding risk; with recent guideline updates, it is important to describe current treatment patterns and the role of bleeding risk in treatment choice. OBJECTIVE: To describe secular trends and determinants of initial P2Y12 inhibitor choice and switching, including deescalation (switch from prasugrel or ticagrelor to clopidogrel). DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study used MarketScan Commercial Claims Data from 2010 to 2019 for patients aged 18 years or older who underwent PCI for ACS, had no P2Y12 inhibitor use in the past year, and filled a P2Y12 inhibitor prescription within 30 days after PCI hospitalization discharge. Data were analyzed from February to May 2022. EXPOSURES: Clopidogrel, prasugrel, and ticagrelor, with determinants including bleeding risk measured using Academic Research Consortium for High Bleeding Risk criteria, sociodemographic characteristics, P2Y12 inhibitor copays, and bleeding events during follow-up. MAIN OUTCOMES AND MEASURES: The prevalence of each P2Y12 inhibitor among patients who initiated the drugs and the prevalence of switching within 12 months after PCI were evaluated. The association between baseline bleeding risk and bleeding manifestations during follow-up and initial treatment and deescalation were calculated using multivariable logistic and Cox proportional hazards regression models. RESULTS: Between 2010 and 2019, 62 423 patients were identified who initiated P2Y12 inhibitors (females, 22.4%; males, 77.6%; mean [SD] age, 54.32 [7.13] years). The prevalence of clopidogrel as initial therapy decreased from 77.5% in 2010 to 29.6% in 2019, while initial use of prasugrel or ticagrelor increased from 22.5% to 60.4%. Within 1 year after PCI, 11.0% of patients switched therapy, mostly for deescalation. Deescalation prevalence increased from 1.8% in 2010 to 12.6% in 2018. Between 2016 and 2018, 8588 of 22 886 (37.5%) patients had major baseline bleeding risk, which decreased the selection of prasugrel or ticagrelor as initial therapy (adjusted odds ratio, 0.78; 95% CI, 0.74-0.84). Among 11 285 patients who initiated prasugrel or ticagrelor, major bleeding risk at baseline (adjusted hazard ratio, 1.11; 95% CI, 1.00-1.23) and the occurrence of bleeding during follow-up (adjusted hazard ratio, 4.42; 95% CI, 3.62-5.93) were associated with deescalation. CONCLUSIONS AND RELEVANCE: A strong shift in preference for prasugrel and ticagrelor as initial therapy following PCI for ACS was observed. Deescalation increased over the study period. Major bleeding risk at baseline was moderately associated with initial treatment choice but had a limited association with deescalation. The increasing use of more potent P2Y12 inhibitors emphasizes opportunities to enhance preemptive patient-centered treatment strategies to maintain optimal antiplatelet activity while reducing bleeding risk during the subacute period following PCI for ACS.