Use of Aspirin Versus Clopidogrel Plus Aspirin After Coronary Artery Bypass Graft Surgery

Abstract

Aspirin and clopidogrel together reduce the risk of recurrent thrombosis-related events in patients with acute coronary syndromes or stent revascularization and may reduce thrombosis-induced saphenous vein graft failure. In this retrospective, observational study, 4297 patients were assigned to 2 groups after coronary artery bypass graft surgery, based on medications prescribed at hospital discharge: aspirin only (n = 3318) or aspirin plus clopidogrel (n = 979). At 4-year follow-up, unadjusted survival was similar between the 2 groups (aspirin—clopidogrel, 87.9% vs aspirin-only, 88.8%, P = .43). After statistical adjustment using Cox regression analysis, dual anti-platelet therapy at hospital discharge was not associated with improved survival (odds ratio 1.055, 95% confidence interval 0.7-1.4, P = .72). In propensity score-based, case-matched populations (962 patients each), similar results were obtained (odds ratio 0.996, 95% confidence interval 0.7-1.4, P = .98). In our study population, aspirin plus clopidogrel did not provide survival benefit over treatment with aspirin alone in 4 years after coronary artery bypass graft surgery.