Low-dose aspirin did not reduce overall incidence of stroke or improve outcomes following a stroke, an analysis of the Women s Health Study showed.
Researchers analyzed data from about 40,000 participants from the Women s Health Study, 460 of whom had been diagnosed with a stroke or transient ischemic attack (TIA) in the preceding year. There was a mean follow-up of 10 years. Ultimately, researchers compared stroke patients against study participants who had not reported a stroke.
The original Women's Health Study randomized healthy female healthcare professionals to receive 600 IU vitamin E or placebo, and low-dose aspirin or placebo on alternate days. The primary endpoint was cardiovascular disease or cancer.
No significant difference was found in total stroke incidence between women randomized to 100 mg of aspirin every other day and those randomized to placebo. Nor was the use of aspirin associated with significantly better functional outcomes in terms of total stroke, ischemic stroke, or hemorrhagic stroke, Pamela M. Rist ScD, of Brigham and Women s Hospital in Boston, and colleagues reported in Stroke: Journal of the American Heart Association.
Whereas randomized assignment to 100 mg of aspirin every other day may reduce the risk of ischemic cerebral vascular events, especially transient ischemic attacks, we did not observe differential effects on functional outcomes from stroke, Rist and colleagues concluded.
ACSH s Dr. Gilbert Ross added a bit of perspective: The study found that, in fact, low-dose alternate-day aspirin did lower the incidence of ischemic stroke the most common form, in which clot or fatty deposits block blood flow. However, the benefit in this type was balanced out by an increase in hemorrhagic stroke, the type caused by bleeding in the brain. The slight reduction in TIA had no long-term benefit, so this study s findings are at odds with the general approach of using aspirin to protect against stroke.