Real-world anticoagulant use and clinical outcomes in postoperative atrial fibrillation after coronary artery bypass grafting: a nationwide practice-based cohort from The Netherlands Heart Registration

Aims Postoperative atrial fibrillation (POAF) occurs in 15-40% of patients following coronary artery bypass grafting (CABG). Existing risk scores are unsuited to its transient nature, and evidence for long-term oral anticoagulation (OAC) remains limited. Although guidelines suggest balancing thromboembolic and bleeding risk, unclear recommendations and limited real-world data drive practice variation. This study evaluated OAC use and outcomes in a national POAF cohort after CABG.Methods and results This retrospective study included adults undergoing isolated CABG (2013-2022) from the Netherlands Heart Registration, linked to mortality and pharmacological data from Statistics Netherlands. Patients with prior atrial fibrillation or preoperative OAC were excluded. Outcomes included short-term complications and long-term cause-specific mortality, comparing OAC with antiplatelets. Among 44 601 CABG patients, 11 054 (24.8%) developed POAF. Of these, 10 750 were successfully linked. Mean age was 68.9 years; 81.7% were male. OAC therapy was initiated in 43.6% of patients, rising from 38.7% (2013) to 53.7% (2022). Within 30 days, mortality was 1.6%, cerebrovascular events 1.3%, and bleeding reintervention 5.4%. Most discontinued OAC after 1 year, while 10.3% continued for 10 years. Crude thromboembolic mortality was lower among OAC users (0.04 vs. 0.42 per 100 patient-years), while bleeding-related mortality remained low (0.00 vs. 0.08). However, survival analyses from 30 days postoperatively showed no significant differences between groups.Conclusion Among POAF patients after CABG, crude mortality was lower in OAC users, but no survival benefit was observed from 30 days onward. Low long-term OAC continuation without excess thromboembolic mortality suggests the potential value of time-limited anticoagulation strategies.