The Risk of Thromboembolism and Need for Oral Anticoagulation After Successful Atrial Fibrillation Ablation

Objectives The aim of this multicenter study was to evaluate the safety of discontinuing oral anticoagulation therapy (OAT) after apparently successful pulmonary vein isolation. Background Atrial fibrillation (AF) is associated with an increased risk of thromboembolic events (TE) and often requires OAT. Pulmonary vein isolation is considered an effective treatment for AF. Methods We studied 3,355 patients, of whom 2,692 (79% male, mean age 57 +/- 11 years) discontinued OAT 3 to 6 months after ablation (Off-OAT group) and 663 (70% male, mean age 59 +/- 11 years) remained on OAT after this period (On-OAT group). CHADS2 (congestive heart failure, hypertension, age [ 75 years and older], diabetes mellitus, and a history of stroke or transient ischemic attack) risk scores of 1 and >= 2 were recorded in 723 (27%) and 347 (13%) Off-OAT group patients and in 261 (39%) and 247 (37%) On-OAT group patients, respectively. Results During follow-up (mean 28 +/- 13 months vs. 24 +/- 15 months), 2 (0.07%) Off-OAT group patients and 3 (0.45%) On-OAT group patients had an ischemic stroke (p = 0.06). No other thromboembolic events occurred. No Off-OAT group patient with a CHADS2 risk score of >= 2 had an ischemic stroke. A major hemorrhage was observed in 1 (0.04%) Off-OAT group patient and 13 (2%) On-OAT group patients (p < 0.0001). Conclusions In this nonrandomized study, the risk-benefit ratio favored the suspension of OAT after successful AF ablation even in patients at moderate-high risk of TE. This conclusion needs to be confirmed by future large randomized trials. (J Am Coll Cardiol 2010; 55: 735-43) (C) 2010 by the American College of Cardiology Foundation