Thromboembolism and Bleeding Risks in Atrial Fibrillation: Outcomes of Oral Anticoagulation After Catheter Ablation

Background Despite the growing use of catheter ablation for atrial fibrillation, large‐scale studies assessing the efficacy and safety of oral anticoagulation (OAC) after ablation, particularly in patients with high stroke risk, remain limited. Methods This prospective study enrolled consecutive patients from the China‐AF (China Atrial Fibrillation) registry between August 2011 and June 2022. Stroke risk was stratified by CHA 2 DS 2 ‐VA score as low (0–1), intermediate (2), or high (≥3). The study end points were thromboembolism (ischemic stroke or systemic embolism), and bleeding (International Society on Thrombosis and Hemostasis major bleeding and clinically relevant non‐major bleeding). A 6‐month landmark analysis was applied to evaluate the association of OAC with end points using incidence rates and Cox models. Results Among 13 669 patients (median follow‐up, 4.0 years), 2637 continued and 11 032 discontinued OAC at the 6‐month landmark. OAC was not associated with reduced thromboembolism risk across low‐ (adjusted hazard ratio [aHR], 1.11 [95% CI, 0.70–1.77]; P =0.649), intermediate‐ (aHR, 0.64 [95% CI, 0.36–1.16]; P =0.141) or high‐stroke risk patients (aHR, 1.05 [95% CI, 0.74–1.48]; P =0.801). In contrast, continued OAC was associated with higher bleeding risk, including clinically relevant non‐major bleeding across stroke risk strata, and International Society on Thrombosis and Hemostasis major bleeding among high‐risk patients (aHR, 2.32 [95% CI, 1.19–4.50]; P =0.013). These results were consistent across subgroups and sensitivity analyses. Conclusions In this large, real‐world cohort of patients with atrial fibrillation undergoing catheter ablation, continued OAC was not associated with lower thromboembolic risk, but with higher major bleeding risk among patients with CHA 2 DS 2 ‐VA scores ≥3. These findings support individualized post‐ablation anticoagulation strategies and warrant future investigation. Registration URL: https://www.clinicaltrials.gov ; Unique Identifier: NCT06987825.