Impact of thrombolysis on stroke outcome at 12 months in a population: the Bern stroke project.

BACKGROUND AND PURPOSE

Thrombolysis improves outcome of patients with acute ischemic stroke, but it is unknown whether thrombolysis has a measurable effect on long-term outcome in a defined population.

METHODS

We prospectively assessed demographic data, management, and outcome of acute ischemic stroke patients admitted within 48 hours to 18 primary care hospitals of the canton of Bern (969 299 inhabitants) during 12 months. Blinded follow-up was obtained at 3 and 12 months. Predictors of mortality and favorable outcome (modified Rankin Scale score ≤2) at 3 and 12 months using logistic regression were analyzed.

RESULTS

From December 2007 to December 2008, 807 patients (mean age, 72 years) were included. Median National Institutes of Health Stroke Scale score on admission was 5; 107 patients (13%) received intravenous, intra-arterial, or mechanical thrombolysis. Estimated cumulative mortality at 3 months was 20.6% and at 12 months 27.4%. Age 75 years or older, higher National Institutes of Health Stroke Scale scores, and higher Charlson comorbidity index were independent predictors of mortality at 3 and 12 months. Estimated favorable outcome at 3 months was 48.2% and at 12 months was 44.6%. Thrombolysis was the only modifiable independent predictor of favorable outcome at 3 (relative risk, 1.49; 95% CI, 1.18-1.89) and 12 months (relative risk, 1.59; 95% CI, 1.24-2.04), whereas age younger than 75 years, male gender, National Institutes of Health Stroke Scale score <4, and lower Charlson comorbidity index were nonmodifiable predictors.

CONCLUSIONS

Thirteen percent of acute ischemic stroke patients admitted within 48 hours to Bernese hospitals underwent thrombolysis, which exerted a measurable effect on 3-month outcome in this population. This effect was sustained at 12 months. Age, stroke severity, Charlson comorbidity index, and male gender were independent nonmodifiable predictors of outcome.