RESUMO
BACKGROUND: Patients with recent coronary artery bypass graft (CABG) surgery are at risk for early graft failure, which is associated with a risk of myocardial infarction and death. In the COMPASS (Cardiovascular OutcoMes for People Using Anticoagulation StrategieS) trial, rivaroxaban 2.5 mg twice daily plus aspirin 100 mg once daily compared with aspirin 100 mg once daily reduced the primary major adverse cardiovascular events (MACE) outcome of cardiovascular death, stroke, or myocardial infarction. Rivaroxaban 5 mg twice daily alone did not significantly reduce MACE. OBJECTIVES: This pre-planned substudy sought to determine whether the COMPASS treatments are more effective than aspirin alone for preventing graft failure and MACE after CABG surgery. METHODS: The substudy randomized 1,448 COMPASS trial patients 4 to 14 days after CABG surgery to receive the combination of rivaroxaban plus aspirin, rivaroxaban alone, or aspirin alone. The primary outcome was graft failure, diagnosed by computed tomography angiogram 1 year after surgery. RESULTS: The combination of rivaroxaban and aspirin and the regimen of rivaroxaban alone did not reduce the graft failure rates compared with aspirin alone (combination vs. aspirin: 113 [9.1%] vs. 91 [8.0%] failed grafts; odds ratio [OR]: 1.13; 95% confidence interval [CI]: 0.82 to 1.57; p = 0.45; rivaroxaban alone vs. aspirin: 92 [7.8%] vs. 92 [8.0%] failed grafts; OR: 0.95; 95% CI: 0.67 to 1.33; p = 0.75). Compared with aspirin, the combination was associated with fewer MACE (12 [2.4%] vs. 16 [3.5%]; hazard ratio [HR]: 0.69; 95% CI: 0.33 to 1.47; p = 0.34), whereas rivaroxaban alone was not (16 [3.3%] vs. 16 [3.5%]; HR: 0.99, CI: 0.50 to 1.99; p = 0.98). There was no fatal bleeding or tamponade within 30 days of randomization. CONCLUSIONS: The combination of rivaroxaban 2.5 mg twice daily plus aspirin or rivaroxaban 5 mg twice daily alone compared with aspirin alone did not reduce graft failure in patients with recent CABG surgery, but the combination of rivaroxaban 2.5 mg twice daily plus aspirin was associated with similar reductions in MACE, as observed in the larger COMPASS trial. (Cardiovascular OutcoMes for People Using Anticoagulation StrategieS [COMPASS]; NCT01776424).