Cochrane Summaries

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Anticoagulants for preventing stroke in patients with nonrheumatic atrial fibrillation and a history of stroke or transient ischaemic attack

Saxena R, Koudstaal PJ
Published Online: 
13 April 2011

Anticoagulants are beneficial and safe for preventing a second stroke in people with nonrheumatic atrial fibrillation and recent cerebral ischaemia. 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 and 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 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. This review identified two trials in which patients with NRAF who had a stroke were treated with anticoagulant therapy. These studies show that anticoagulants safely reduce the risk of recurrent stroke by two-thirds, despite a higher chance of major extracranial bleeds. There was no increased risk of intracranial bleeds.