Early Anti-Coagulation after Ischemic Stroke due to Atrial Fibrillation is Safe and Prevents Recurrent Stroke.

BACKGROUND Patients with acute cardio-embolic stroke from atrial fibrillation (AF) are at risk for recurrence with up to 50% of recurrent stroke occurring within two weeks of the index event. Anti-coagulation with heparinoids within 48 hours of stroke has been shown to increase risk of symptomatic intracranial hemorrhage (ICH) with no clear benefit on early stroke recurrence. METHODS This study was a retrospective chart review of consecutive patients who were admitted to the stroke service at the Foothills Medical Centre between 2009 and 2011. All patients with an acute stroke with a cardio-embolic etiology and a diagnosis of atrial fibrillation were reviewed. We hypothesized that anti-coagulation within two weeks of stroke, appropriately begun because of a diagnosis of AF, decreased rates of recurrent stroke without causing an increase in rates of symptomatic ICH. RESULTS Between 2009-2011, 324 patients were identified with cardio-embolic stroke secondary to AF. Within two weeks of stroke onset 61.4% (199/324) of patients were therapeutic on anti-coagulation. Patients who were anti-coagulated had a smaller median index stroke volume (3.2 ml vs 18.4 ml). Three (0.9%) patients suffered a clinically significant ICH. Recurrent stroke occurred in 11 patients (3.4%) within the two-week period. Therapeutic anti-coagulation within two weeks of initial stroke was associated with a decreased risk of recurrent stroke (RR 0.1, 95% CI 0.03-0.64). CONCLUSIONS Anti-coagulation within two weeks of acute stroke in patients with AF appears to be safe among patients with smaller infarcts and prevents early recurrent infarction.