Impact of Warfarin and Dual Antiplatelet Therapy on Graft Failure After Coronary Endarterectomy: A Retrospective Cohort Study.

Purpose: Coronary endarterectomy combined with coronary artery bypass grafting (CE-CABG) effectively achieves coronary revascularization in patients with diffuse atherosclerotic coronary artery disease (CAD). However, the loss of the subendothelial tissue at the CE-CABG coronary artery accelerates local thrombosis, leading to CE-CABG graft failure. Dual antiplatelet therapy (DAT) and warfarin plus aspirin (WPA) are the two most common anticoagulation strategies post CE-CABG. This retrospective study compares the clinical outcomes and graft failure rates associated with these two approaches.

Methods: This study is a retrospective cohort study. Between July 2016 and April 2024, 102 patients with diffuse CAD underwent CE-CABG. Six patients were excluded. In total, 96 patients (mean age 59.8 ± 7.7 years) enrolled in the study (43 in DAT group and 53 in WPA group). The DAT group received aspirin (100 mg, qd) and clopidogrel (75 mg, qd) for 1 year postoperatively, transitioning to aspirin (100 mg, qd) after 1 year. The WPA group received warfarin (international normalized ratio, INR remained at 1.8-2.5) and aspirin (100 mg, qd) for 3 months postoperatively, followed by DAT after 3 months, changed to aspirin monotherapy after 1 year. The primary endpoint was graft failure of the CE-CABG graft.

Results: Four patients died during the perioperative period (1 in DAT group, 3 in WPA group), resulting in an overall perioperative mortality rate of 4.2%. Five patients were lost for follow-up. Mean follow-up time was 38 months. Three patients died during the follow-up period (1 in DAT group, 2 in WPA group). The CE-CABG graft patency of the WPA group was significantly higher compared to the DAT group (88.1% vs. 50.0%, P < 0.001). Kaplan-Meier analysis showed that the median graft failure time was significantly longer in the WPA group (77 months, 95% CI 69-85) compared to the DAT group (73 months, 95% CI 17-129, P = 0.017). A higher proportion of the DAT group was classified as NYHA III-IV compared to the WPA group (26.2% vs. 10.2%, P = 0.046). One patient of the WPA group had a gastrointestinal bleeding event, and the overall incidence of bleeding events was not statistically different between the two groups.

Conclusion: Using the WPA strategy after CE-CABG significantly reduces the rate of graft failure and improves cardiac function without increasing the risk of bleeding events.