Benefit and safety of dual anti-platelet therapy after coronary artery bypass grafting: a Meta-analysis of 15 studies

Abstract

Objective Under the method of a Meta-analysis, evaluate the early and long-term curative effect after coronary artery bypass grafting with the comparison of benefit and safety between dual anti-platelet therapy and aspirin therapy alone. Methods Medline, Embase, ScienceDirect and Cochrane Library were searched to identify randomized controlled trials concerning the comparison of benefit and safety between dual anti-platelet therapy and aspirin therapy alone, with extraction effect sizes including mortality, bleeding events, myocardial ischemia and graft occlusion. Newcastle-Ottawa Scale and Jadal scales were used to evaluate the quality of observational case-control studies and randomized controlled studies. Statistical analysis was performed using Meta R. 15.2 software package. Results 15 literatures were enrolled for Meta-analyses, including 8 randomized controlled studies, 3 prospective observational studies and 4 retrospective observational studies. Among a total of 31 365 patiens, 8 642 patients were received combination therapy of aspirin and clopidogrel after CABG, and 22 723 patients were received combination therapy of aspirin and placebo or aspirin therapy alone. The Meta-analysis results, with comparison of the early postoperative curative effect in 13 literatures, showed that, relative to aspirin therapy alone, dual anti-platelet therapy could reduce the risk of graft occlusion(OR=0.53, 95%CI: 0.37-0.76, P=0.001), reduce the risk of myocardial ischemia(OR=0.84, 95%CI: 0.71-0.99, P=0.038), reduce the risk of mortality after CABG(OR=0.47, 95%CI: 0.36-0.61, P<0.001), simultaneously not increase the risk of bleeding events. The Meta-analysis results, with comparison of the long-term postoperative curative effect in 2 literatures, showed that the significant difference could not be found between two method of therapy about affecting the risk of graft occlusion(OR=0.40, 95%CI: 0.02-6.90, P=0.523), myocardial ischemia(OR=0.49, 95%CI: 0.04-6.10, P=0.597), and mortality(OR=0.55, 95%CI: 0.13-2.80, P=0.420). Conclusion Relative to aspirin therapy alone, dual anti-platelet therapy has better efficacy and safety in early postoperative term. However better long-term curative effect of dual anti-platelet therapy are not be confirmed, and more long-term follow-up studies are necessary to provide evidence based medicine. Key words: Coronary artery bypass grafting; Clopidogrel; Graft occlusion; Meta-analysis