Warfarin use following ischemic stroke among Medicare patients with atrial fibrillation

Background: Elderly patients with ischemic stroke and atrial fibrillation are at especially increased risk for recurrent stroke. Warfarin sodium is highly effective in reducing this risk. Objective: To determine the use of warfarin among a population sample of elderly patients with atrial fibrillation hospitalized for ischemic stroke. Methods: The Connecticut Peer Review Organization conducted a chart review of Medicare patients, aged 65 years or older, hospitalized in 1994 with a diagnosis of atrial fibrillation. Patients with a principal diagnosis of acute myocardial infarction or another indication for anticoagulation were excluded. Results: Among 635 patients (402 women; 585 white; 218 greater than or equal to 85 years old; 147 with a new diagnosis of atrial fibrillation), 334 had stroke as a principal diagnosis. Among those discharged alive after a stroke, only 147 (53%) of 278 were prescribed warfarin at discharge. Furthermore, among 130 (47%) of 278 patients not prescribed warfarin at discharge, 81 (62%) of 130 were also not prescribed aspirin. Increased potential benefit (additional vascular risk factors) was not associated with a higher rate of warfarin use. Low risk for anticoagulation (lack of risk factors for bleeding) was associated with a slightly higher rate of warfarin use. Among those with an increased risk of stroke and a low risk for bleeding (ideal candidates), 124 (62%) of 278 were discharged on a regimen of warfarin. Conclusion: Anticoagulation of elderly stroke patients with atrial fibrillation, even among ideal candidates, is underused. The increased use of warfarin among these patients represents an excellent opportunity for reducing the risk of recurrent stroke in this high-risk population.