Anticoagulation Timing in Cardioembolic Stroke and Recurrent Event Risk

OBJECTIVES Guidelines recommend to initiate anticoagulation within 4-14 days after cardioembolic stroke. Data supporting this did not account for key factors potentially affecting the decision to initiate anticoagulation such as infarct size, hemorrhagic transformation, or high risk features on echocardiography. METHODS We pooled data from stroke registries of 8 comprehensive stroke centers across the United States. We included consecutive patients admitted with ischemic stroke and atrial fibrillation. The primary predictor was timing of initiating anticoagulation (0-3 days, 4-14 days, or >14 days) and outcomes were recurrent stroke/TIA/systemic embolism, symptomatic intracerebral hemorrhage (sICH), and major extracranial hemorrhage (ECH) within 90 days. RESULTS Among 2084 patients, 1289 met the inclusion criteria. The combined endpoint occurred in 10.1% (n = 130) subjects (87 ischemic events, 20 sICH, and 29 ECH). Overall, there was no significant difference in the composite endpoint between the three groups: 0-3 days [10.3% (64/617)], 4-14 days [(9.7%) 52/535)], >14 days [10.2% (14/137), p=0.933]. In adjusted models, patients started on anticoagulation between 4-14 days did not have a lower rate of sICH (vs. 0-3 days) (OR 1.49 95% CI 0.50 - 4.43) neither did they have a lower rate of recurrent ischemic events (vs. > 14 days) (OR 0.76 95% CI 0.36 - 1.62, p = 0.482). INTERPRETATION In this multicenter real world cohort, the recommended (4-14 days) time frame to start oral anticoagulation was not associated with reduced ischemic and hemorrhagic outcomes. Randomized trials are required to determine the optimal timing of anticoagulation initiation. This article is protected by copyright. All rights reserved.