Single Versus Dual Antiplatelet Therapy After Coronary Artery Bypass Grafting for Unprotected Left-Main Coronary Disease

BACKGROUND: The use of dual antiplatelet therapy (DAPT) after coronary revascularization for left-main disease is still debated. The study aimed to characterize patients who received dual versus single antiplatelet therapy (SAPT) after coronary artery bypass grafting (CABG) for unprotected left-main disease and compare the outcomes of those patients. RESULTS: This multicenter retrospective cohort study included 551 patients who were grouped into 2 groups: patients who received SAPT (n = 150) and those who received DAPT (n = 401). There were no differences in age ( P = 0.451), gender ( P = 0.063), smoking ( P = 0.941), diabetes mellitus ( P = 0.773), history of myocardial infarction ( P = 0.709), chronic kidney disease ( P = 0.615), atrial fibrillation ( P = 0.306), or cerebrovascular accident ( P = 0.550) between patients who received SAPT versus DAPT. DAPTs were more commonly used in patients with acute coronary syndrome [87 (58%) vs. 273 (68.08%); P = 0.027], after off-pump CABG [12 (8%) vs. 73 (18.2%); P = 0.003] and in patients with radial artery grafts [1 (0.67%) vs. 32 (7.98%); P < 0.001]. While SAPTs were more commonly used in patients with low ejection fraction [55 (36.67%) vs. 61 (15.21%); P < 0.001] and in patients with postoperative acute kidney injury [27 (18%) vs. 37 (9.23%); P = 0.004]. The attributed treatment effect of DAPT for follow-up major adverse cerebrovascular and cardiac events was not significantly different from that of SAPT [β, -2.08 (95% confidence interval (CI), -20.8-16.7); P = 0.828]. The attributed treatment effect of DAPT on follow-up all-cause mortality was not significantly different from that of SAPT [β, 4.12 (CI, -11.1-19.32); P = 0.595]. There was no difference in bleeding between groups ( P = 0.666). CONCLUSIONS: DAPTs were more commonly used in patients with acute coronary syndrome, after off-pump CABG, and with radial artery grafts. SAPTs were more commonly used in patients with low ejection fraction and acute kidney injury. Patients on DAPT after CABG for left-main disease had comparable major adverse cerebrovascular and cardiac events and survival to patients on SAPT, with no difference in bleeding events.