Anticoagulation after catheter ablation of atrial fibrillation: An unnecessary evil? A systematic review and meta-analysis

Background: Anticoagulation in patients with atrial fibrillation (AF) is currently based on clinical parameters (CHA₂DS ₂-VASc score) that have been shown to predict cerebrovascular events (CVE). Controversy exists as to whether CVE risk persists unmodified after successful catheter ablation, as observational studies suggest a lower risk of CVE. Current guidelines recommend continued oral anticoagulation (OAC) based on the CHA ₂DS ₂-VASc score risk profile. Methods: We conducted a systematic literature review of all studies published up to July 31, 2018, that reported CVE after catheter ablation of AF and compared patients on or off OAC. Random-effects models were used to demonstrate the risk of CVE and major bleeding in on-OAC vs off-OAC patients. This analysis was further stratified by CHADS₂ and CHA ₂DS ₂-VASc score. Results: We retained 16 studies, 10 prospective cohort and 6 retrospective cohort, that met inclusion criteria, and which enrolled 25 177 patients: 13 166 off-OAC and 12 011 on-OAC. No significant difference in the incidence of CVE emerged between on-OAC and off-OAC patients after AF ablation (risk ratio, 0.66; confidence interval [CI], 0.38, 1.15). Similar results were found after stratification by CHADS₂ and CHA ₂DS ₂-VASc score. Off-OAC patients suffered significantly less bleeding than those on OAC (RR, 0.17; CI, 0.09, 0.34). Of note, the percentage of patients with AF recurrence impacts the treatment effect in the two groups (P = 0.001). Conclusions: In this metanalysis, the risk-benefit ratio favored the suspension of OAT after successful AF ablation even in patients at moderate-high risk. Whether the reported results can be extended also to non-vitamin K antagonist oral anticoagulants warrants further investigations.