Controlled trial of aspirin in cerebral ischemia.

The findings from a double-blind multicenter clinical trial of aspirin for treatment of cerebral ischemia are reviewed. Of 303 patients who had carotid transient ischemic attacks (TIAs), 125 were selected for carotid reconstructive surgery and were then randomly assigned treatment with aspirin or placebo. The remaining 178 patients were also randomly assigned to an aspirin or placebo regimen. Analysis of the first 6 months of follow-up showed a differential in favor of aspirin when death, nonfatal cerebral or retinal infarction and the occurrence of TIAs were grouped and considered together as end points. Restriction of end points to death or nonfatal cerebral or retinal infarction yielded no statistically significant differential between the aspirin and placebo groups. After these results were published, a study group from Canada reported that aspirin was effective in preventing threatened stroke, but that this effect was limited to males. Review of our nonsurgical group with respect to sex shows findings consistent with those of the Canadian study for the end points of stroke or death. Inclusion of the occurrence of TIAs in the group of end points, however, revealed that aspirin is effective in females as well as males.