Preventive aspirin for women?

Two-in-one Bayer Women’s adds 300 milligrams of calcium to 81 mg of aspirin. The cost is almost double that of regular low-dose aspirin.

For years, daily low-dose aspirin was seldom prescribed to women because of the misperception that heart attacks mainly happened to men. Today, the U.S. Preventive Services Task Force recommends a daily baby aspirin (81 milligrams) for most women and men who have moderately elevated coronary risk. There’s even a product marketed specifically to women: Bayer Women’s.

Now, the first large clinical trial to test aspirin’s effects in women has found that aspirin therapy doesn’t always work the same way in women as it does in men. While aspirin protects against heart attack in middle-aged and older men, it does not do so in women ages 45 to 64, even if they’re at high coronary risk. This finding is from a 10-year Harvard study of nearly 40,000 women published in March 2005. However, the study found that low-dose aspirin does reduce the chance of a first heart attack in women age 65 or older--a group that’s far more likely to suffer a heart attack than younger women.

Interestingly, for middle-aged and older women in the study, aspirin cut the risk of a first ischemic (clot-related) stroke by 24 percent. That’s an important finding, since, unlike men, women suffer more strokes than heart attacks. The stroke-preventing benefit of low-dose aspirin has not been seen in studies of men. Women and men who have already had a heart attack or stroke should be on preventive aspirin or another blood-thinning medication. Here are some guidelines for healthy women:

Assess your risk. Use the risk calculator at www.med-decisions.com to determine your heart-attack risk. For stroke risk, use the calculator at www.nhlbi.nih.gov/about/framingham/stroke.htm .

If you’re under 65. Most younger women don’t need aspirin. But if you have an increased stroke risk or high heart-attack risk, you may decide, with your doctor, to take aspirin.

If you’re over 65. Consider aspirin if you have an increased risk of stroke or a 3 percent or greater risk of heart attack or death from coronary disease in the next five years.

If aspirin is contraindicated. Your doctor may prescribe a different blood-thinning medication if you have had or are at risk for gastrointestinal bleeding, an uncommon but sometimes serious side effect of aspirin, or if you have other medical problems.