Does Catheter Ablation Eliminate the Need for Oral Anticoagulation?

Abstract

Stroke and thromboembolism are recognized as one of the most serious complications of atrial fibrillation (AF) because they are associated with a substantial risk of morbidity and mortality.1 Oral anticoagulation (OAC) with warfarin is highly effective in preventing thromboembolic events in patients with AF.2 However, treatment with OAC necessitates frequent monitoring and dietary and drug restrictions and may be associated with serious side effects, of which hemorrhagic stroke is the most devastating. Therefore, adequate risk stratification of AF patients and meticulous evaluation of benefits and risks are mandatory. Various risk factors have been identified as contributing to the risk for stroke in AF and risk stratification schemes such as the CHADS2 score have been established and validated.3 Although this score identifies patients who benefit most and least from anticoagulation, the threshold for use of anticoagulation is controversial, especially for those at intermediate risk (stroke rate, 3% to 5% per year).4 Updated guidelines tend to an earlier anticoagulation strategy withholding OAC only in patients who are truly low risk.5 Article see p 615 The optimal anticoagulation treatment of patients undergoing successful AF catheter ablation is even less well defined. Limited data are available regarding the risk of thromboembolism with and without warfarin after AF ablation. Challenges arise from the definition of success, with noncontinuous monitoring techniques underestimating true arrhythmia recurrence rates,6 an increasing amount of asymptomatic AF after ablation,7 controversial data on long-term efficacy of AF catheter ablation,8,9 and on how much AF is necessary to provoke thromboembolic events. For these reasons, current recommendations rely on the patient's individual baseline thromboembolic risk irrespective of a potentially curative ablation procedure to decide on long-term anticoagulation strategies.5,10 Patients having a CHADS2 score ≥2 are generally not recommended to …