The Women's Health Study is the first large clinical trial to study the use of low-dose aspirin to prevent heart attack and stroke in women. The 10-year randomized, double-blind, placebo-controlled study was conducted among nearly 40,000 healthy women age 45 and older. Although studies have shown that low-dose aspirin reduces the risk of a first heart attack in men, there have been few such studies in women. The study was supported by the National Institutes of Health's National Heart, Lung, and Blood Institute and the National Cancer Institute.
The Women's Health Study found that aspirin did not prevent first heart attacks or death from cardiovascular causes in women. Low-dose aspirin (100 mg on alternate days) lowered the incidence of a first major cardiovascular event (nonfatal heart attack, non-fatal stroke, or death from cardiovascular causes) by 9 percent. This was not statistically significant. Stroke was 17 percent lower in the aspirin group, a statistically significant difference. The findings of the study will be presented at the American College of Cardiology's (ACC) annual meeting in Orlando, FL and also published online in The New England Journal of Medicine March 7, 2005 and in print in the March 31 issue.
The greatest benefit appeared to be in women 65 and older. In this sub-group, low-dose aspirin reduced the risk of major cardiovascular events by 26 percent. However, the benefits of low-dose aspirin therapy must be weighed against the risk of an increased chance of internal bleeding, a well-known side effect of aspirin use.
The bottom line is that many women, especially those 65 and older, may benefit from taking low-dose aspirin every other day to prevent stroke. But it is important for women to weigh the risk and benefits of taking aspirin and to consult with their doctor. Above all, women, like men, should adopt the well-proven approaches that reduce the risk of heart disease -- eating for heart health, getting regular physical activity, maintaining a healthy weight, not smoking, and controlling high cholesterol, high blood pressure, and diabetes.
The Women's Health Study also assessed the benefits of vitamin E supplementation (600 IU every other day). These findings, also presented at ACC, indicate there was no evidence of cardiovascular benefit or increased risk from taking a vitamin E supplement. Analyses of the effect of vitamin E and aspirin on cancer are under way.