How soon after a stroke should anticoagulation be started?
Large strokes and those due to cardioembolism are most likely to bleed. As such, it is common practice to wait 1 month after a large stroke before initiating anticoagulation for atrial fibrillation.
Patients with very small cardioembolic strokes may be started on anticoagulation within 1 to 2 days. In patients with large strokes at high risk for embolization (mechanical valves, cardiac thrombus), anticoagulation may be started cautiously after 5 to 15 days.
Retrospective data suggest bridging with heparin or low-molecular-weight heparin causes more bleeding.
In the absence of a hypercoagulable state, it is acceptable to start warfarin at low doses to achieve therapeutic anticoagulation slowly. Some clinicians suggest aspirin until an international normalized ratio (INR) of 2 is achieved.
