Aspirin Cuts Strokes in Middle-Age Women, Study Shows

For older women, the small doses of aspirin also appear to lower the risk of heart attack.

ORLANDO, Fla. — Aspirin has proven for the first time that it can save healthy women’s lives by preventing strokes but not heart attacks in middle-age women, and it can prevent both in women age 65 and older, a major study reported Monday.

The Women’s Health Study, involving nearly 40,000 healthy nurses, was the first major long-term study to test the preventive benefits of aspirin in women. The results are at odds with what studies have found in men, who can dramatically cut their risk of dying of heart attacks, but not stroke, by taking aspirin.

“I don’t think we should be that surprised,” lead author Paul Ridker of Brigham and Women’s Hospital in Boston said at an American College of Cardiology meeting here. “Women do suffer proportionately more strokes than men.”

The study also showed that vitamin E didn’t provide any protective benefit, but it didn’t confirm findings from a major study last fall which suggested that vitamin E could be harmful.

Previous studies of low-dose aspirin in both men and women show that heart patients who regularly take low-dose aspirin, usually less than 100 milligrams, are less likely to die of heart disease or have a second heart attack.

Anyone who takes an aspirin during a heart attack is more likely to survive and less likely to have a second attack later on. But until now, no one had studied whether low-dose aspirin can prevent heart attacks in healthy women.

After a decade, women who used aspirin had a 17 percent lower risk of stroke, driven by a 24 percent reduction in the most common form of stroke caused by blood clots, the study found.

Women age 65 and older were 30 percent less likely to have a stroke caused by a blood clot and 34 percent less likely to suffer a heart attack.

Nonsmokers and former smokers benefited the most.

Current guidelines, drawn entirely from research in men, advise doctors not to recommend aspirin for women who have less than a 10 percent risk of heart disease over the next decade.

The new findings likely will send doctors back to the drawing board to figure out when it’s appropriate to advise middle-age women to take a baby aspirin, which can cause serious gastrointestinal bleeding.

“Our guidelines were based on limited data. Now we have robust data,” says Sidney Smith of the University of North Carolina-Chapel Hill and a co-chairman of the American Heart Association committee that writes treatment guidelines for cardiologists. “Older women might benefit.”

The AHA released a statement Monday urging women whose physicians have prescribed baby aspirin, especially those with heart disease risk factors, to continue.

“We want to be sure these women realize that this study does not apply to them,” AHA President Alice Jacobs says.

Women randomly were assigned to take a placebo or 100 milligrams of aspirin, slightly more than a baby aspirin of 81 mg but less than an adult dose of 325 milligrams, which can double the risk of serious gastrointestinal bleeding.

Findings also were released online by The New England Journal of Medicine.