Canadian researchers concluded that anticoagulation therapy remains woefully underused for the prevention of ischemic stroke in high-risk patients with atrial fibrillation.
The study was funded by the Canadian Stroke Network and conducted at the nonprofit Institute for Clinical Evaluative Science (ICES) in Toronto, Ontario. It found that of patients from a hospital-based stroke registry who were known to have atrial fibrillation (and who also were considered at high risk for developing stroke) who then experienced a first-time ischemic stroke, 90% were receiving no warfarin therapy or had been taking subtherapeutic doses of the anticoagulant (Gladstone DJ et al. Stroke. doi:10.1161/STROKEAHA.108.516344 [published online ahead of print August 28, 2008]). The rate of ischemic stroke among all patients with atrial fibrillation is about 4.5% (the researchers said the rate would be much higher in their study population); warfarin lowers the rate to about 1.4%.
Mitka M. Patients With Atrial Fibrillation Often Receive Improper Levels of Warfarin. JAMA. 2008;300(14):1640. doi:10.1001/jama.300.14.1640