July 23, 2001 -- In a dramatic change in the field of heart disease prevention, the American Heart Association is advising doctors to stop prescribing hormone replacement therapy to women to prevent heart disease. Moreover, the AHA says that healthy women should not be told that taking estrogen might protect their hearts.
The AHA also is advising that estrogen be stopped immediately if a woman has a heart attack and that hormone replacement only be resumed after careful consultation between a woman and her doctor.
But "healthy women who are taking estrogen don't need to be afraid," because the new advisory concerns only women who have heart disease, says heart specialist Lori Mosca, MD, PhD, author of the AHA's science advisory published in Circulation: Journal of the American Heart Association.
Women who have a history of heart disease and who are taking hormone replacement therapy, either estrogen alone or estrogen/progestin combination therapy, should talk to their doctors about the risks and benefits of continued therapy.
Mosca, director of preventive cardiology at New York Presbyterian Hospital of Columbia University and Cornell University, tells WebMD that the AHA acted quickly in response to new information. The new information is a spate of recent studies suggesting that estrogen replacement may actually increase the risk for heart attack in some cases.
The final word on the risks and benefits of hormone replacement for healthy women will come from an ongoing federal study called the Women's Health Initiative, which will not be completed until 2005.
Wulf Utian, MD, executive director of the North American Menopause Society, tells WebMD that the AHA advisory is very similar to an advisory issued late last year by the International Menopause Society. "It is basically don't start, don't stop," says Utian. For women who have heart disease, hormone replacement should not be initiated, but if a woman is already taking estrogen, there is no reason to stop.
Mosca says she has no qualms about prescribing hormone replacement for a healthy woman who is experiencing menopause symptoms such as hot flashes and sleep disturbances because estrogen remains the best treatment for these symptoms. Hormone replacement can also protect against bone-thinning osteoporosis, but Mosca points out that there are other compounds -- such as Fosamax, Evista, or Calcitonin -- that are used to both prevent and treat osteoporosis.
Mosca says that when doctors are counseling healthy women about hormone replacement, that counseling should omit any suggestion that hormone replacement can prevent heart disease. Women who are interested in heart disease prevention should direct their efforts toward lifestyle modification, says Mosca: for example, smoking cessation, weight loss, and regular exercise. Appropriate medications should be considered for women who have high blood pressure or high cholesterol.
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.
The following are some topics a woman should discuss with her doctor before starting or resuming hormone replacement therapy: