Abstract 9964: Vorapaxar, a Platelet Thrombin-Receptor Antagonist, in Medically Managed Patients with Non-ST-Segment Elevation Acute Coronary Syndrome: Results from the TRACER Trial
Purpose: This is a prespecified post-randomization subgroup analysis to evaluate efficacy and safety outcomes of vorapaxar in the TRACER trial in patients that were medically managed without revascularization procedures during index hospitalization.
Methods: Vorapaxar, a novel platelet-protease-activated receptor-1 antagonist, was randomized with placebo in 12,944 patients with NSTE ACS. We explored the effect of vorapaxar vs placebo among medically managed patients at discharge (n=4194; 32.4 %) vs those undergoing revascularization (n=8750; 67.6%) from discharge to end of follow-up, with adjustments for baseline differences. Events rates are provided as 2-yr Kaplan-Meier estimates.
Results: The medically managed patients were more likely to be older and female and have prior MI, prior CABG, and decreased renal function. The 2-yr event rate of the primary outcome (CV death, MI, stroke, recurrent ischemia with rehospitalization, or urgent coronary revascularization) was 16.9% with vorapaxar and 17.3% with placebo (HR 0.95; 95% CI 0.81-1.14), with no interaction between study drug and management strategy (p=0.63). The rate of the key secondary endpoint (CV death, MI, and stroke) was 13.9% with vorapaxar and 15.1% with placebo (HR 0.88; 95% CI 0.73-1.07), with no interaction (p=0.86). Lower MI rates were observed in medically managed patients treated with vorapaxar (9.3% vs 11.1% [HR 0.79; 95% CI 0.63-0.99). Vorapaxar significantly increased GUSTO moderate or severe bleeding in medically managed patients (HR 1.52; 95% CI 1.04-2.22) and in patients undergoing revascularization (HR 1.32; 95% CI 0.99-1.76). In the medical group, intracranial hemorrhage (ICH) occurred in 18 patients with vorapaxar and in 1 patient with placebo, whereas ICH occurred in 17 vorapaxar patients and 9 placebo patients treated with revascularization, with no significant interaction (p=0.056).
Conclusion: In patients with NSTE ACS treated medically, the efficacy of vorapaxar was consistent with the main findings of the TRACER trial. Bleeding hazard with vorapaxar tended to be higher in medically treated patients, possibly due to patient selection factors.
- © 2012 by American Heart Association, Inc.