Cochrane Summaries

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Anticoagulants versus antiplatelet therapy for preventing stroke in patients with nonrheumatic atrial fibrillation and a history of stroke or transient ischemic attack

Saxena R, Koudstaal PJ
Published Online: 
13 April 2011

Anticoagulants are more effective than antiplatelet drugs to prevent a second stroke in people with atrial fibrillation. Nonrheumatic atrial fibrillation (NRAF) is a heart rhythm disorder commonly found in patients who have had a stroke. Patients with NRAF have an irregular heart beat. This can cause the formation of a blood clot in the left atrium of the heart. This clot may break away and block a cerebral artery, thus causing a stroke. Patients who have had a stroke in the presence of NRAF have a high risk of another stroke. Anticoagulant drugs, such as warfarin, make the blood 'thinner' and prevent the formation of blood clots and hence could prevent stroke. However, anticoagulant drugs may also cause bleeding in the brain and this complication could offset any benefits. Aspirin may be a safer alternative. This review identified two trials in which patients with NRAF who had a stroke were treated with anticoagulants or antiplatelet therapy. These studies show that anticoagulants are superior to antiplatelet agents to reduce the risk of recurrent stroke.