"Studying how warfarin therapy is associated with intracranial hemorrhages is challenging because these events are rare, albeit devastating," says Margaret Fang, MD, MPH, who led the study as an MGH research fellow and is now at the University of California at San Francisco (UCSF). "Because lower level warfarin therapy can lead to a much higher risk of ischemic stroke, we also wanted to examine whether less intensive treatment, which recent guidelines have suggested for older patients, actually results in a lower risk of hemorrhage."
Atrial fibrillation, a type of irregular heartbeat, is a common and strong risk factor for stroke. By leading to the formation of blood clots that travel to the brain, the condition is believed to account for about 80,000 ischemic strokes a year and can increase a patient's overall stroke risk fivefold. Many patients with atrial fibrillation are treated with blood-thinning medications like warfarin, and previous studies by members of this research team and others have confirmed that achieving appropriate levels of anticoagulation reflected by levels of 2.0 or more on a blood test called the INR can significantly reduce the risk that a stroke will occur.
However, elevated anticoagulation levels can increase the risk of brain hemorrhage, a rare but dangerous complication of warfarin therapy. Concern about the risk of hemorrhage, especially among older people, has led some pat
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Contact: Sue McGreevey
smcgreevey@partners.org
617-724-2764
Massachusetts General Hospital
15-Nov-2004