A Randomized Controlled Trial Of Prasugrel For Prevention Of Early Saphenous Vein Graft Thrombosis

Objectives. To test whether administration of prasugrel after coronary artery bypass grafting (CABG) reduces saphenous vein graft (SVG) thrombosis. Use of aspirin after CABG improves graft patency, but administration of other antiplatelet agents has yielded equivocal results. Methods. We performed a double-blind trial randomizing patients to prasugrel or placebo after CABG at four United States centers. Almost all patients were receiving aspirin. Follow-up angiography, optical coherence tomography (OCT), intravascular ultrasound (IVUS), and near-infrared spectroscopy (NIRS) were performed at 12 months. The primary efficacy endpoint was prevalence of OCT-detected SVG thrombus. The primary safety endpoint was incidence of Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO) severe bleeding. Results. The study was stopped early due to slow enrollment after randomizing 84 patients. Mean age was 64 +/- 6 years; 98% of the patients were men. Follow-up angiography was performed in 59 patients. IVUS was performed in 52 patients, OCT in 53 patients, and NIRS in 33 patients. Thrombus was identified by OCT in 56% vs 50% of patients in the prasugrel vs placebo groups, respectively (P=.78). Angiographic SVG failure occurred in 24% of patients in the prasugrel arm vs 40% in the placebo arm (P=.19). The 1-year incidence of major adverse cardiovascular events was 14.3% vs 2.4% in the prasugrel and placebo groups, respectively (P=.20), without significant differences in GUSTO severe bleeding (P=.32). Conclusion. Early SVG failure occurred in approximately one-third of patients. Prasugrel did not decrease prevalence of SVG thrombus 12 months after CABG.