Long‐term risk of stroke and bleeding post–atrial fibrillation ablation

BACKGROUND: Catheter ablation (CA) is an established therapy for atrial fibrillation (AF). Studies regarding long-term real-world outcomes post-CA have inconsistently accounted for oral anticoagulation (OAC). OBJECTIVES: To describe patterns of OAC use post-CA and to compare the OAC-adjusted long-term risk of stroke and major bleeding in AF patients with and without CA. METHODS: A population-based cohort of AF patients was constructed in Quebec and Ontario, Canada (1999-2014). Propensity score matching was performed to determine the incidence rates of stroke and major bleeding among those undergoing CA, adjusted for time-dependent OAC use. RESULTS: From the entire cohort, 6391 patients were identified as having undergone CA as compared to 482 977 patients who did not. Of these, 1240 patients with government medical insurance undergoing CA were matched with 2427 patients without CA. Post-CA, 78%, 65%, and 61% remained on an OAC at 1, 2, and 5 years, while 75%, 71%, and 68% of patients not undergoing CA were on OACs at 1, 2, and 5 years. At follow-up, there was no statistically significant difference for stroke (adjusted hazard ratio [HR], 0.88; 95% CI, 0.63 to 1.21) or major bleeding (adjusted HR, 0.88; 95% CI, 0.73 to 1.06). CONCLUSION: No evidence was found that CA significantly decreases the risk of stroke or major bleeding when adjusting for OAC use over time. It may be prudent to continue anticoagulation post-CA based on patient-risk profile until randomized trials demonstrate both reduced stroke rates with CA, and improved safety (balancing stroke and bleeding risk) with OAC discontinuation post-CA.