TUESDAY, May 24, 2005 (HealthDay News) -- Taking the anti-clotting medication warfarin (Coumadin) may reduce stroke risk by more than two-thirds in people with a prior history of atrial fibrillation, a condition that causes an irregular heartbeat in the heart's upper chambers and greatly increases the risk of stroke.
In the study, researchers at the University of Texas Health Science Center, in San Antonio, assessed the occurrence and characteristics of strokes in patients who'd taken part in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM).
In their latest analysis of AFFIRM patient data, the researchers looked at variables for ischemic stroke -- a type of attack triggered by a sudden decrease in blood flow to the brain. The Texas team tracked outcomes in patients with atrial fibrillation for between two to six years.
They found a number of factors associated with risk of ischemic stroke, including older age, being female, a history of diabetes and a prior history of stroke or mini-stroke. The presence of atrial fibrillation was also associated with a 60 percent increased risk of stroke, while the use of warfarin was associated with a 69 percent decreased stroke risk.
Based on the findings, the study authors conclude that "anticoagulation therapy [using warfarin] should be maintained in patients who have a history of atrial fibrillation and risk factors for stroke, even when the recurrent atrial fibrillation has not been documented."
The study appears in the May 23 issue of the Archives of Internal Medicine.
The American Heart Association has more about atrial fibrillation.