Stopping Oral Anticoagulation After Catheter Ablation for Atrial Fibrillation in Patients With High Risk of Stroke: STOP‐OAC Study

Background The benefit of continuing oral anticoagulation (OAC) after catheter ablation (CA) for atrial fibrillation (AF) in patients with a high risk of stroke remains unclear. The Safeness or Threat Of Pausing‐Oral anticoagulant therapy After Catheter ablation for atrial fibrillation study (STOP‐OAC study) aimed to investigate the safety and efficacy of OAC discontinuation after CA for AF in patients with CHADS 2 score ≥2. Methods We enrolled 1655 consecutive patients with AF with CHADS 2 score ≥2 (mean CHADS 2 of 2.4 and CHA 2 DS 2 ‐VASc of 3.8) who underwent first‐time CA at 8 institutions in Japan from April 2021 to March 2024. The main analysis was the landmark analysis at 240 days after CA compared between the 2 groups either on or off OAC at 240 days. Results There were 327 patients who had stopped OAC at 240 days (off‐OAC group), and 1241 patients who continued OAC at 240 days (on‐OAC group). Patients in the off‐OAC group compared with those in the on‐OAC group less often had nonparoxysmal AF (43.1% and 54.3%), and history of ischemic stroke (7.7% and 23.4%) with lower CHADS 2 score (2.2±0.5 and 2.4±0.6). The incidence of ischemic stroke beyond 240 days was not different between the 2 groups (0.4% and 0.5% per patient‐year, P =0.21), whereas the incidence of major or clinically relevant nonmajor bleeding beyond 240 days was significantly lower in the off‐OAC group than in the on‐OAC group (0.4% and 1.7% per patient‐year, P <0.001). Conclusions The STOP‐OAC study provides real‐world evidence supporting the safety and efficacy of early OAC discontinuation after CA of AF in selected patients with CHADS 2 score ≥2.