Which Patients with Atrial Fibrillation Do Not Need Anticoagulation Therapy with Warfarin?

Anticoagulation therapy with warfarin is not indicated for use in patients with non- valvular atrial fibrillation who are at low risk for embolic cerebral vascular events. The classification of "low risk for embolic stroke" is defined as a 1 percent annual risk for stroke or lone atrial fibrillation (i.e., age younger than 65 years without history of hypertension, transient ischemic attack, stroke, coronary heart disease, recent congestive heart failure, or diabetes). Anticoagulation therapy with warfarin is beneficial in patients with atrial fibrillation who are at moderate or high risk for stroke. Patients with absolute contraindications to anticoagulation therapy (e.g., thrombocytopenia, recent trauma or surgery, hemorrhagic stroke, alcoholism) should not take warfarin. [Strength of recommendation: A, based on meta-analyses of large randomized controlled trials (RCTs).