During ward consultations we are often asked whether a patient with stroke and atrial fibrillation (AF) should receive anticoagulants to prevent recurrence. Of late this question has been less often asked, perhaps because our colleagues prefer a more definitive answer than the one we are able to give to a question that they quite rightly believe ought to have a definite answer. Our reply is usually that we do not know, because the data needed to make a decision are either nonexistent or inadequate.
Anticoagulant therapy should, in theory, be helpful. The rationale is reasonably logical and based on the notion that AF (from any cause) leads in some way to the formation of a thrombus in the left atrium. The thrombus then can be carried away— in whole or in part—to the brain, causing cerebral infarction and stroke; subsequent, long-term anticoagulant therapy interferes with this process of thromboembolism and