Many patients who should receive the anticoagulant warfarin according to guidelines do not, a new study finds.
A significant number of atrial fibrillation patients who should be prescribed the anticoagulant warfarin according to guidelines never receive it and a significant portion of those who do receive it stop taking it within a year, a study finds. The study was published online last month in the journal Stroke.
Guidelines from the American Heart Association and the American Stroke Association state that patients who have atrial fibrillation (AF) as well as ischemic stroke (IS) or transient ischemic attack (TIA) should be prescribed warfarin to prevent strokes due to clotting. However, the study found that of 2,460 IS and TIA patients, 291 had AF, of whom 84.8% were prescribed warfarin either alone or in conjunction with aspirin and/or the antiplatelet drug clopidogrel. Of the patients who received warfarin, approximately 80% continued to take it for the next year, despite the fact that patients are supposed to stay on it indefinitely.
There was a decrease in initial use of warfarin by patients with a CHADS2 score greater than 3, indicating an increase in stroke risk due to congestive heart failure, hypertension, diabetes, or being over 75. Women were 56% less likely than men to still be on warfarin a year later than were men.
Patients in the study were drawn from the Get With The Guidelines-Stroke national quality improvement registry and the Adherence eValuation After Ischemic Stroke Longitudinal (AVAIL) Registry. The research was supported by funding from Bristol-Myers Squibb, which makes Coumadin, a brand name of warfarin.