Low-dose aspirin shown to reduce risk of first stroke in women

The Women’s Health Study is a large, randomized, double-blind, placebo-controlled trial funded by both the National Heart, Lung and Blood Institute and the National Cancer Institute to evaluate the benefits and risks of low dose aspirin as well as vitamin E supplementation in the primary prevention of cardiovascular disease. The trial included healthy women 45 years of age and older who were monitored for 10 years for first major cardiovascular events.

With regard to aspirin, data addressing these issues in women have been limited. During follow-up, 477 major cardiovascular events were confirmed in the aspirin group as compared to 522 in the placebo group, a 9 percent overall reduction that was not statistically significant. However, the benefit of aspirin within the WHS was due almost entirely to a statistically significant reduction in stroke events without a reduction in heart attack rates. The most consistent benefits were observed among women 65 years of age and older. Among such women, low- dose aspirin use resulted in a 26 percent reduction in risk of major cardiovascular events.

“From a clinical standpoint, the new data suggest that many women are likely to attain a net benefit from preventive aspirin therapy,” said Paul Ridker, M.D., and a BWH cardiologist also involved in the WHS clinical trial.