Association of Aspirin Dose and Vorapaxar Safety and Efficacy in Patients With Non-ST-Segment Elevation Acute Coronary Syndrome (from the TRACER Trial)

作者：Mahaffey Kenneth W^*; Huang Zhen; Wallentin Lars; Storey Robert F; Jennings Lisa K; Tricoci Pierluigi; White Harvey D; Armstrong Paul W; Aylward Philip E; Molitemo David J; Van de Werf Frans; Chen Edmond; Leonardi Sergio; Rorick Tyrus; Held Claes; Strony John; Harrington Robert A

来源：American Journal of Cardiology, 2014, 113(6): 936-944.

DOI：10.1016/j.amjcard.2013.11.052

Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome (TRACER) trial compared vorapaxar and placebo in 12,944 high-risk patients with non ST-segment elevation acute coronary syndrome. We explored aspirin (ASA) use and its association with outcomes. Kaplan-Meier event rates were compared in groups defined by ASA dose (low, medium, and high). Landmark analyses with covariate adjustment were performed for 0 to 30, 31 to 180, and 181 to 365 days. Of 12,515 participants, 7,523, 1,049, and 3,943 participants were treated with low-, medium-, and high-dose ASA at baseline, respectively. Participants enrolled in North America versus elsewhere were more often treated with a high dose at baseline (66% vs 19%) and discharge (60% vs 3%). Unadjusted cardiovascular death, myocardial infarction, stroke, hospitalization for ischemia, or urgent revascularization event rates tended to be higher with higher baseline ASA (18.45% low, 19.13% medium, and 20.27% high; p for trend = 0.15573). Unadjusted and adjusted hazard ratios (95% confidence intervals) for effect of vorapaxar on cardiovascular (unadjusted p for interaction = 0.065; adjusted p for interaction = 0.140) and bleeding (unadjusted p for interaction = 0.915; adjusted p for interaction = 0.954) outcomes were similar across groups. Landmark analyses showed similar safety and efficacy outcomes with vorapaxar and placebo by ASA dose at each time point except for 0 to 30 days, when vorapaxar tended to be worse for efficacy (hazard ratio 1.13, 95% confidence interval 0.89 to 1.44, p for interaction = 0.0157). In conclusion, most TRACER participants were treated with low-dose ASA, although a high dose was common in North America. High-dose participants tended to have higher rates of ischemic and bleeding outcomes. Although formal statistical testing did not reveal heterogeneity in vorapaxar%26apos;s effect across dose subgroups, consistent trends support use of low-dose ASA with other antiplatelet therapies.

• 出版日期2014-3-15