American Heart Association Discourages HRT to Prevent Heart Disease
For years, one of the cornerstones of preventive medicine was the belief that estrogen protects the heart. In the years before menopause, when women produce estrogen naturally, women are almost immune to heart disease, but after menopause the heart disease risk for women climbs until it equals that for men. Based on this observation as well as animal studies that demonstrated that estrogen had a beneficial effect on blood vessels, medical experts believed that replacing estrogen after menopause could reduce the risk of heart disease in older women.
Throughout the 1980s and most of the 1990s this belief was bolstered by the results from large studies, which showed that women who take hormone replacement therapy had fewer heart attacks and strokes than women who didn't take hormones. The belief was so strong that in the AHA's 1995 guidelines on preventing second heart attacks in people with heart disease doctors were told to "consider estrogen for all women with heart disease," says Mosca.
Nonbelievers raised questions about the weakness of these studies citing, for example, data that suggested women who take hormone replacement are less likely to smoke, more likely to be well educated, and more likely to exercise and eat healthy diets. In short, these women have a low risk for heart disease because of their lifestyle.
When hormone replacement was studied in a more controlled setting among women who had heart attacks the findings were surprising -- not only did estrogen not prevent a second heart attack but also it appeared to increase the risk of having one. Another study among women who have heart disease tracked the effect of estrogen on the heart arteries and found that estrogen did not slow hardening of the arteries -- which can lead to heart disease.
Late last month these findings were replicated in two more studies.
Utian says the belief that hormone replacement protected the heart was a big factor in convincing American doctors to recommend the treatment and American women to take estrogen, but he says he isn't sure what impact the AHA advisory will have on the use of estrogen. "I don't think most women come into a doctor's office saying 'I want hormones to protect my heart,'" says Utian.
"Women stay on hormones because of quality-of-life issues: They feel better, sex improves," says Utian. Mosca agrees that "hormones make women feel better" and that is a powerful impetus to keep taking the pills.
For that reason some women will want to resume taking hormones after a heart attack, she says. Although the AHA is recommending that hormones be stopped right after a woman has a heart attack, Mosca says it is not making a firm recommendation on resuming hormone therapy. That decision, she says, should be based on extensive consultation between the woman and her doctor.