Sex Differences and Functional Outcome after Intravenous Thrombolysis

BACKGROUND AND PURPOSE: Women have a worse outcome after stroke compared with men, although in intravenous thrombolysis (IVT)-treated patients, women seem to benefit more. Besides sex differences, age has also a possible effect on functional outcome. The interaction of sex on the functional outcome in IVT-treated patients in relation to age remains complex. The purpose of this study was to compare outcome after IVT between women and men with regard to age in a large multicenter European cohort reflecting daily clinical practice of acute stroke care. METHODS: Data were obtained from IVT registries of 12 European tertiary hospitals. The primary outcome was poor functional outcome, defined as a modified Rankin scale score of 3 to 6 at 3 months. We stratified outcome by age in decades. Safety measures were symptomatic intracranial hemorrhage and mortality at 3 months. RESULTS: In this cohort, 9495 patients were treated with IVT, and 4170 (43.9%) were women with a mean age of 71.9 years. After adjustments for baseline differences, female sex remained associated with poor functional outcome (odds ratio, 1.15; 95% confidence interval, 1.02-1.31). There was no association between sex and functional outcome when data were stratified by age. Symptomatic intracranial hemorrhage rate was similar in both sexes (adjusted odds ratio, 0.93; 95% confidence interval, 0.73-1.19), whereas mortality was lower among women (adjusted odds ratio, 0.83; 95% confidence interval, 0.70-0.99). CONCLUSIONS: In this large cohort of IVT-treated patients, women more often had poor functional outcome compared with men. This difference was not dependent on age.