Thrombolysis treatment for acute stroke: issues of efficacy and utilization in women.

BACKGROUND: Some studies report that women with ischemic stroke are more likely to benefit from intravenous tissue thrombolysis (IV tPA) treatment, but are less likely to receive the treatment compared with men. We review the literature on sex differences in utilization and efficacy of IV tPA and suggest directions for future studies.
METHODS: We identified studies that reported on sex differences in either the utilization or efficacy of IV tPA treatment for acute ischemic stroke.
RESULTS: Data from observational studies of IV tPA use show evidence of under-utilization in women, although wide variability between studies suggests that differences are specific to local conditions and populations. Prior analyses of randomized trial data show strong evidence that women but not men receive statistically and clinically significant benefit from IV tPA treatment. Observational studies of the effectiveness of IV tPA treatment in men and women have limited validity because of the absence of comparable control groups.
CONCLUSION: There is good evidence that there are clinically important sex differences in both the efficacy and utilization of IV tPA, with women gaining more benefit from treatment than men. The current paradox between greater efficacy but lower utilization of IV tPA in women requires greater attention from the stroke community. Larger placebo-controlled thrombolysis trials, specifically powered to look at sex differences in treatment efficacy, and more studies designed to understand the underlying reasons for the lower utilization of IV tPA in women are required.