Stroke Risk-Based Anticoagulation After Atrial Fibrillation Ablation: ALONE-AF Post-Hoc Analysis

BACKGROUND Discontinuation of oral anticoagulant (OAC) in patients without recurrent atrial arrhythmia after ablation for atrial fibrillation (AF) has been demonstrated to reduce composite outcomes of stroke, systemic embolism, and major bleeding compared with continued OAC. OBJECTIVE This study aimed to evaluate the optimal OAC strategy according to baseline stroke risk and AF recurrence. METHODS In this post-hoc analysis of the Long-Term Anticoagulation Discontinuation after Catheter Ablation for Atrial Fibrillation (ALONE-AF) trial, patients were stratified according to CHA2DS2-VASc score ≤2 and ≥3. Within each stratum, outcomes were compared between the OAC discontinuation and continuation subgroups. The cumulative incidence of stroke, systemic embolism, and major bleeding at 2 years was estimated using the Kaplan-Meier method, with competing risk analysis accounting for AF recurrence. RESULTS Among 840 patients, 584 and 256 had a CHA2DS2-VASc score ≤2 (mean age 62.0±7.5 years, 15.9% female) and ≥3 (mean age 68.9±7.3 years, 45.3% female), respectively. In the CHA2DS2-VASc ≤2 stratum, the primary outcome occurred in one patient (0.4%) in discontinuation subgroup vs. six (2.4%) in continuation subgroup (absolute difference -1.9 percentage points, P=0.066). In the CHA2DS2-VASc ≥3 stratum, two events (1.8%) occurred in the continuation subgroup only (absolute difference -1.8 percentage points, P=0.172). All major bleeding events (n=5) occurred in the continuation subgroups. Competing risk analysis yielded consistent results. CONCLUSIONS In this exploratory post-hoc analysis, no statistically significant differences in outcomes were observed between OAC strategies when stratified by CHA2DS2-VASc score, though event numbers were limited. Larger prospective trials are needed to confirm these observations. TRIAL REGISTRATIONS ClinicalTrials.gov Identifier: NCT04432220.