Background and objective: Dual antiplatelet therapy is one of the main treatments in acute coronary syndrome (ACS). Switching antiplatelet agents may be necessary in some patients to improve efficacy or safety. The objective of this study was to determine the prevalence, predictors, and implications of clinical switching in patients during hospital admission and 1-year follow-up at discharge.
Methods: Observational, prospective, multicenter registry study in patients discharged following an admission for ACS and followed up for 1 year. We analyzed ischemic and bleeding events as well as treatment changes.
Results: We recruited 1717 patients; in-hospital switching occurred in 425 (24.8%): 15.1% to clopidogrel and 84.9% to newer antiplatelet drugs (prasugrel or ticagrelor). Those switched to newer antiplatelets were younger, with lower scores on the GRACE and CRUSADE scales, admitted more frequently for ST-elevation myocardial infarction and underwent more invasive management and percutaneous revascularization. The clinical cardiologist was responsible for most in-hospital switching to newer antiplatelets (79.6%). The loading dose of the second antiplatelet did not affect incidence of bleeding events. Post-discharge switching was infrequent (2%) and depended mainly on clinical indications; only 30% was related to a new ACS.
Conclusions: In a contemporary registry with ACS, in-hospital switching of antiplatelet drugs was frequent. Those switched to newer antiplatelets were younger and admitted more frequently for ST-elevation myocardial infarction. Post-discharge switching was infrequent.