Early use of non‐vitamin K antagonist oral anticoagulants after cardiac surgery compared with warfarin for postoperative atrial fibrillation

BACKGROUND: The introduction of non-vitamin-K-antagonist oral anticoagulants (NOAC) has shifted the landscape of anticoagulation in the setting of atrial fibrillation (AF), as an alternative to warfarin. Despite extensive evidence for NOACs in non-perioperative and non-valvular AF, there remains little consensus on anticoagulation choice for patients with postoperative atrial fibrillation (POAF) after cardiac surgery. METHODS: This retrospective, observational study included 2263 patients who underwent cardiac surgery between 1 March 2016 and 13 January 2023 at a tertiary cardiac centre. Patients with pre-existing AF, valvular AF and transcatheter interventions were excluded. Short- and long-term outcomes were compared between patients who received a NOAC and those who received warfarin for POAF. A Cox regression model was constructed to identify independent predictors for time-to-mortality. Subgroup analysis was performed based on the type of surgery, including CABG-only, aortic valve replacement (AVR)-only, and combined surgery cohorts. RESULTS: Of the 2263 patients, 556 (24.5%) developed POAF. Of those who developed POAF, 162 were anticoagulated with warfarin and 65 were anticoagulated with a NOAC, including apixaban, rivaroxaban and dabigatran. There were three cases of permanent stroke in the warfarin group compared with no cases in the NOAC group. All-cause 30-day and one-year readmission rates were similar between groups. The use of NOAC or warfarin did not impact overall survival in the Kaplan-Meier analysis. Subgroup analysis demonstrated similar outcomes in CABG-only, AVR-only and combined surgery groups. CONCLUSIONS: Warfarin and NOAC performed similarly in short- and long-term complications, suggesting NOAC as a plausible alternative to warfarin for anticoagulation in POAF.