A clinical trial of estrogen-replacement therapy after ischemic stroke.

Background: Observational studies have suggested that estrogen-replacement therapy may reduce a woman's risk of stroke and death. Methods: We conducted a randomized, double-blind, placebo-controlled trial of estrogen therapy (1 mg of estradiol-17 beta per day) in 664 postmenopaus al women (mean age, 71 years) who had recently had an ischemic stroke or tr ansient ischemic attack. Women were recruited from 21 hospitals in the Unit ed States and were followed for the occurrence of stroke or death. Results: During a mean follow-up period of 2.8 years, there were 99 strokes or deaths among the women in the estradiol group, and 93 among those in th e placebo group (relative risk in the estradiol group, 1.1; 95 percent conf idence interval, 0.8 to 1.4). Estrogen therapy did not reduce the risk of d eath alone (relative risk, 1.2; 95 percent confidence interval, 0.8 to 1.8) or the risk of nonfatal stroke (relative risk, 1.0; 95 percent confidence interval, 0.7 to 1.4). The women who were randomly assigned to receive estr ogen therapy had a higher risk of fatal stroke (relative risk, 2.9; 95 perc ent confidence interval, 0.9 to 9.0), and their nonfatal strokes were assoc iated with slightly worse neurologic and functional deficits. Conclusions: Estradiol does not reduce mortality or the recurrence of strok e in postmenopausal women with cerebrovascular disease. This therapy should not be prescribed for the secondary prevention of cerebrovascular disease.