New treatment options for stroke prevention in atrial fibrillation.

Atrial fibrillation (AF) is the most common arrhythmia requiring treatment. Its most devastating consequence is thromboembolic stroke. Therapy with warfarin is indicated in most patients, as it has been shown conclusively to reduce the risk of stroke. Aspirin is an inferior alternative except in certain low-risk patients or for patients with an absolute contraindication to warfarin. Guidelines have been published for the administration of antithrombotic therapy in AF, but many patients who are candidates for anticoagulation do not receive this therapy. Even as this therapy is under-utilized, the indication for anticoagulation is expanding. Indefinite continuation of anticoagulation should be considered in higher-risk patients despite the appearance that sinus rhythm has been restored because asymptomatic (or silent) AF occurs frequently. Newer agents that offer substantial benefit over warfarin are being developed and would enhance compliance with anticoagulation in AF if these novel therapies prove to be safe and equivalent to warfarin in efficacy.