Warfarin for stroke prevention following anterior ST-elevation myocardial infarction

Abstract

To assess the benefit of vitamin K antagonist (VKA) therapy for prevention of ischemic stroke following anterior ST-elevation myocardial infarction (STEMI) in patients with reduced ejection fraction. A prospective institutional-based registry was used to identify survivors of anterior STEMI with a post-STEMI ejection fraction of 40% or less over a 10-year period. Clinical and procedural characteristics were collected from medical records and vital status from the Social Security Death Index. Outcomes were compared on the basis of VKA use. The primary outcome was a composite of ischemic stroke, death, and clinically relevant bleeding. A secondary analysis examined the effects of low-molecular-weight heparin bridging therapy. The primary outcome occurred in 24.7% (40/162) of VKA patients and 20.5% (22/107) of non-VKA patients [adjusted hazard ratio (HR), 1.30; 95% confidence interval (CI), 0.71-2.31]. Ischemic stroke occurred in 2.5 and 0.9% of VKA patients and non-VKA patients, respectively (adjusted HR, 2.81; 95% CI, 0.31-25.1). There was no significant difference in the rate of bleeding or death between groups. The addition of a low-molecular-weight heparin bridge to VKA therapy was associated with increased bleeding events (adjusted HR, 2.55; 95% CI, 1.04-6.24). Ischemic stroke was infrequent in the 6 months following anterior STEMI irrespective of VKA treatment status. The routine use of anticoagulation for prevention of stroke following anterior STEMI may not be warranted.