Doctors participating in trials expected stents that prop open narrowed brain arteries would be superior to therapy aimed at controlling risk factors.
But results showed the opposite. They abruptly stopped the trials when patients with stents were found to be more likely to have a second stroke or die.
The medical therapy found to be more effective included daily blood thinning medications and aggressive control of blood pressure and cholesterol.
Rush University Medical Center participated in the study, which is in this week's New England Journal of Medicine.