Very low risk of thromboembolic events in patients undergoing successful catheter ablation of atrial fibrillation with a CHADS2 score ≤3: a long-term outcome study.

Background: Long-term cessation of oral anticoagulation (OAC) after catheter ablation of atrial fibrillation (AF) has been deemed controversial. The safety of this management strategy in patients without recurrent AF and with historically elevated risks for thromboembolism remains largely unknown. In this study, we sought to evaluate the long-term results of OAC cessation after successful catheter ablation of AF.

Methods And Results: OAC and antiarrhythmic drugs (AADs) were discontinued irrespective of AF type or baseline CHADS(2) (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, prior stroke or transient ischemic attack) risk score in 327 patients (mean age, 63±13 years; 79% men) with drug-refractory AF after catheter ablation (mean CHADS(2) score, 1.89±0.95; median, 2.0). Patients with a CHADS(2) score of 2 (45.4%) and 3 (23.2%) accounted for 68.8% of this cohort. In patients with a high risk of recurrence or prior thromboembolic complications, OAC was continued for up to 6 to 12 months postablation and antiplatelet therapy was administered to all patients who maintained sinus rhythm upon OAC interruption. After a follow-up of 46±17 months (range, 13-82 months), 82% remained AF free (off AADs). Significant predictors of late AF recurrence (P<0.05) were nonparoxysmal AF (hazard ration [HR], 1.83), female sex (HR, 2.19), age ≥60 years (HR, 1.81), left atrial size >40 mm (HR, 3.52), CHADS(2) score ≥2 (HR, 1.81), and early recurrences (HR, 5.52). No symptomatic ischemic cerebrovascular events were detected during follow-up despite interruption of OAC in 298 (91%) patients and AADs in 293 (89%) patients.

Conclusions: No significant thromboembolic-related morbidity is observed when AADs and OAC are discontinued after successful catheter ablation of AF in patients with a CHADS(2) score ≤3 who are maintained on antiplatelet therapy during long-term follow-up.