Use of Thienopyridine Prior to Presentation for Acute Coronary Syndromes and Association With Safety and Efficacy of Vorapaxar: Insights From the TRACER Study

Background: In TRACER, vorapaxar, a novel PAR-1 antagonist, was compared with placebo in pts with NSTE ACS treated with standard of care, including >90% use of thienopyridine at baseline. In this context, vorapaxar was associated with a modest efficacy signal and increased bleeding. We assessed use of thienopyridine prior to hospitalization for the index ACS event and its association with efficacy and safety of vorapaxar. Methods: The TRACER trial included 12,944 pts randomized to vorapaxar or placebo and followed for a median of 502 days. Prior use of thienopyridine was defined as being on treatment during the 7 days prior to the index ACS presentation. The main outcomes were a composite of cardiovascular death, myocardial infarction, stroke, recurrent ischemia with rehospitalization, and urgent coronary revascularization; a composite of cardiovascular death, myocardial infarction, and stroke; and bleeding complications. Safety outcomes were non-CABG-related GUSTO and TIMI bleeding. Results: The vast maj...