Preadmission oral anticoagulant treatment and clinical outcome among patients hospitalized with acute stroke and atrial fibrillation: a nationwide study.

BACKGROUND AND PURPOSE: Preadmission oral anticoagulant treatment (OAT) has been linked with less severe stroke and a better outcome in patients with atrial fibrillation. However, the existing studies have methodological limitations and have, with one exception, not included hemorrhagic strokes. We performed a nationwide historic follow-up study using data from population-based healthcare registries to assess the effect of preadmission OAT on stroke outcomes further.

METHODS: We identified 11 356 patients with atrial fibrillation admitted to hospital with acute stroke (including ischemic stroke and intracerebral hemorrhage) between 2003 and 2009. Propensity score-matched analyses were used to compare stroke severity (Scandinavian Stroke Scale score) and mortality among 2175 patients with preadmission OAT and 2175 patients without preadmission OAT.

RESULTS: A total of 2492 (21.9%) patients received OAT at the time of their stroke. Preadmission OAT was associated with a lower risk of severe stroke (Scandinavian Stroke Scale score at time of admission, <30 point; propensity score-matched odds ratio, 0.74; 95% confidence interval, 0.63-0.86) and lower 30-day mortality rate (propensity score-matched adjusted odds ratio, 0.83; 95% confidence interval, 0.71-0.98).

CONCLUSIONS: Only a minority of hospitalized patients with acute stroke with atrial fibrillation received OAT at the time of stroke. Preadmission OAT was associated with less severe stroke and lower 30-day mortality rate in a propensity score-matched analysis.