Dual Anti-platelet Therapy After Coronary Artery Bypass Grafting: Is There Any Benefit? A Systematic Review and Meta-Analysis

Abstract

Background Anti-platelet therapy is an important component of medical therapy post coronary artery bypass grafting (CABG). While aspirin administration is a Class I indication after CABG, the benefit of concomitant clopidogrel is a controversial issue. Methods We searched OVID Medline, Cochrane, Scopus, and EMBASE for randomized control trials and observational studies comparing aspirin +/- placebo to aspirin+clopidogrel after CABG. Results Eleven articles (five randomized control trials and six observational studies) including 25,728 patients met inclusion criteria. Early saphenous vein graft occlusion was reduced with the use of dual anti-platelet therapy (risk ratio (RR)=0.59, 95% CI 0.430.82, p=0.02). In-hospital or 30-day mortality was lower with aspirin+clopidogrel (0.8%) compared to aspirin alone (1.9%) (p<0.0001), while risk of angina or perioperative myocardial infarction was comparable (RR=0.60, 95% CI 0.311.14, p=0.12). Patients treated with aspirin+clopidogrel demonstrated a trend towards a higher incidence of major bleeding episodes as compared to patients treated with aspirin alone (RR=1.17, 95% CI 1.001.37, p=0.05). In a pooled analysis of studies involving off-pump CABG compared to aspirin alone, dual anti-platelet therapy reduced the risk of perioperative myocardial infarction and saphenous graft occlusion by 68% (47% to 71%) and 55% (2% to 79%) respectively. Conclusion Dual anti-platelet therapy after CABG improved early saphenous vein graft patency, but may increase the risk of bleeding. The use of dual anti-platelet therapy appears to be most beneficial in patients undergoing off-pump CABG. Prospective randomized studies are necessary to determine whether this beneficial effect of dual therapy is also achieved in patients undergoing on pump CABG. doi: 10.1111/jocs.12074 (J Card Surg 2013;28:109116)