Clopidogrel Monotherapy in Patients With Chronic Coronary Syndrome Following Coronary Artery Bypass Grafting: A Nationwide Cohort Study

BACKGROUND AND OBJECTIVES: The optimal antiplatelet strategy for secondary prevention in patients with chronic coronary syndrome (CCS) after coronary artery bypass grafting (CABG) remains controversial. We compared long-term clinical outcomes according to the antiplatelet strategy after CABG. METHODS: A total of 29,898 patients with CCS who underwent CABG were identified from the Korean National Health Insurance Service database between January 2010 and December 2020. After applying exclusion criteria, the population was stratified based on antiplatelet use at discharge: dual antiplatelet therapy (DAPT, n=7,304), aspirin monotherapy (n=1,524), or clopidogrel monotherapy (n=218). The primary efficacy endpoint was major adverse cardiac and cerebrovascular events (MACCE), a composite of all-cause death, spontaneous myocardial infarction, and stroke up to 10 years. The primary safety endpoint was major bleeding requiring transfusion. RESULTS: The risk of MACCE was higher in the aspirin monotherapy group compared with DAPT at 10 years (39.9% vs. 47.7%, adjusted hazard ratio [HR], 1.16; 95% confidence interval [CI], 1.06-1.27). No significant difference was observed between DAPT and clopidogrel monotherapy (39.9% vs. 40.4%, adjusted HR, 1.05; 95% CI, 0.85-1.29). The risk of major bleeding requiring transfusion was lower with clopidogrel monotherapy than with DAPT (2.1% vs. 5.6%, adjusted HR, 0.36; 95% CI, 0.14-0.98), while rates were similar between DAPT and aspirin monotherapy (5.6% vs. 6.5%, adjusted HR, 1.06; 95% CI, 0.81-1.38). CONCLUSIONS: In patients with CCS undergoing CABG, clopidogrel monotherapy was associated with comparable ischemic outcomes and a lower risk of major bleeding compared with DAPT. Clopidogrel monotherapy may offer a favorable balance of efficacy and safety as an alternative to DAPT for secondary prevention in this population. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT06881901.