A Meta-Analysis Comparing Aspirin Alone Versus Dual Antiplatelet Therapy for the Prevention of Venous Graft Failure Following Coronary Artery Bypass Surgery

Abstract

Background: Aspirin (ASA) monotherapy is the current standard of care after coronary artery bypass grafting (CABG) to prevent saphenous vein graft (SVG) failure. Several small, randomized clinical trials (RCTs) have suggested that dual antiplatelet therapy (DAPT) may be more effective at preventing SVG failure than ASA alone; however, it is unclear whether some P2Y12 inhibitors are more effective than others for the prevention of SVG failure.

Methods: Scientific databases and websites were searched to find RCTs. Both traditional pairwise meta-analysis using random-effect model and network meta-analysis using mixed-treatment comparison models were performed to compare the efficacy of various anti-platelet strategies for the prevention of SVG failure.

Results: Nine RCTs, which included a total of 1677 patients, were analyzed. Compared to ASA alone, DAPT decreased the risk of graft failure by 37% (RR: 0.63, 95% CI: 0.47-0.86; p = 0.003). In the moderator analysis, the decreased risk of graft failure with DAPT was not significantly different in the ASA + clopidogrel group than in the ASA + ticagrelor group (P-interaction = 0.17). The results of the network meta-analysis were consistent with those from pairwise analyses. The risk of major bleeding was not statistically significantly different between DAPT and ASA alone (RR: 1.35, 95% CI: 0.62-2.94; p = 0.45).

Conclusion: In post-CABG patients, DAPT seems to be more effective at preventing graft failure than ASA alone. This strategy does not seem to significantly increase major bleeding risk. Clopidogrel- and ticagrelor-based DAPT seem to be equally effective for this indication.

Keywords: Antiplatelet therapy; Aspirin; Coronary artery bypass grafting; P2Y12 inhibitors; Saphenous vein graft.