Antiplatelet therapy and coronary artery bypass grafting: a systematic review and network meta-analysis.

OBJECTIVES Acetylsalicylic acid (ASA) monotherapy is the standard of care after coronary artery bypass grafting (CABG), but the benefits of more intense antiplatelet therapy, specifically dual antiplatelet therapy (DAPT), require further exploration in CABG patients. We performed a network meta-analysis to compare the effects of various antiplatelet regimens on saphenous vein graft patency, mortality, major adverse cardiovascular events and bleeding among CABG patients. METHODS We searched Cochrane Central Register of Controlled Trials, Medical Literature Analysis and Retrieval Systems Online, Excerpta Medica Database, Cumulative Index to Nursing and Allied Health Literature, American College of Physicians Journal Club and conference proceedings for randomized controlled trials. Screening, data extraction, risk of bias assessment and Grading of Recommendations Assessment, Development and Evaluation were performed in duplicate. We conducted a random effect Bayesian network meta-analysis including both direct and indirect comparisons. RESULTS We included 43 randomized controlled trials studying 15 511 patients. DAPT with low-dose ASA and ticagrelor [odds ratio (OR) 2.53, 95% credible interval (CrI) 1.35-4.72; I2 = 55; low certainty] or clopidogrel (OR 1.56, 95% CrI 1.02-2.39; I2 = 55; very low certainty) improved saphenous vein graft patency when compared to low-dose ASA monotherapy. DAPT with low-dose ASA and ticagrelor was associated with lower mortality (OR 0.52, 95% CrI 0.30-0.87; I2 = 14; high certainty) and lower major adverse cardiovascular events (OR 0.63, 95% CrI 0.44-0.91; I2 = 0; high certainty) when compared to low-dose ASA monotherapy. Based on moderate certainty evidence, DAPT was associated with an increase in major bleeding. CONCLUSIONS Our results suggest that DAPT improves saphenous vein graft patency, mortality and major adverse cardiovascular event. As such, surgeons and physicians should consider re-initiating DAPT for acute coronary syndrome patients after their CABG, at the expense of an increased risk for major bleeding. CLINICAL TRIAL REGISTRATION International Prospective Register of Systematic Reviews ID Number CRD42019127695.