Vorapaxar in patients with peripheral artery disease and acute coronary syndrome: Insights from Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome (TRACER)

Background In the TRACER trial, vorapaxar, a protease-activated receptor-1 antagonist, plus standard care in non-ST-segment elevation acute coronary syndrome (NSTE ACS) patients did not significantly reduce the primary composite end point but reduced a key secondary end point and significantly increased bleeding. History of peripheral artery disease (PAD) was a risk-enrichment inclusion criterion. We investigated the efficacy and safety of vorapaxar in NSTE ACS patients with documented PAD. Methods TRACER was a double-blind, randomized trial comparing vorapaxar with placebo in 12,944 patients with NSTE ACS. Results In total, 936 (7.2%) patients had a history of PAD. Ischemic events occurred more frequently among patients with PAD (25.3%) versus no PAD (12.2%, P <.001), and Global Use of Strategies to Open Occluded Coronary Arteries moderate/severe bleeding was more common in PAD (9.1%) versus no PAD (5.0%, P =.004). Similar rates of the composite end point (cardiovascular death, myocardial infarction, or stroke) occurred in patients with PAD treated with vorapaxar and placebo (21.7% vs 24.8%, P interaction =.787). Patients with PAD treated with vorapaxar, when compared with placebo, also had a numerical reduction in peripheral revascularization procedures (8.1% vs 9.0%, P =.158) and a lower extremity amputation rate (0.9% vs 1.5%, P =.107). Vorapaxar increased Global Use of Strategies to Open Occluded Coronary Arteries moderate/severe bleeding similarly in patients with PAD (hazard ratio 1.47, 95% CI 0.89-2.45) and without (hazard ratio 1.48, 95% CI 1.22-1.79; P interaction =.921). Conclusions Patients with NSTE ACS and PAD were at increased risk for ischemic events. Lower rates of ischemic end points, peripheral revascularization, and amputation with vorapaxar did not reach statistical significance but warrant further investigation. Vorapaxar increased bleeding in both patients with and without PAD at a similar magnitude of risk.