News release on the Federally Funded HERS study
Study Questions Estrogen-Heart Link
By DANIEL Q. HANEY, AP Medical Editor
ANAHEIM, Calif. (AP) - Challenging a medical doctrine that has stood for two decades, a study found no evidence that estrogen supplements protect older women from heart disease.
The findings are likely to confuse doctors and patients alike about the already complicated decision of whether to take estrogen for many years after menopause. Estrogen has both benefits and risks, including an increased chance of breast cancer.
The latest research, released Monday, is the second major study to question the doctrine that hormone replacement is a powerful way to ward off heart disease, the leading killer of older women.
That belief has been a centerpiece of women's health care since the 1980s and has helped make the estrogen pill Premarin the most widely prescribed medicine in the United States.
Many doctors think estrogen helps the heart largely because it seems to improve cholesterol levels after women go through menopause. The pills lower total cholesterol and ``bad'' cholesterol, while raising ``good'' cholesterol. Doctors assume these changes translate into less heart disease, even though no experiments definitively prove this.
The first to put the idea to the test was the landmark Heart and Estrogen-progestin Replacement Study - HERS - finished two years ago. Its conclusion shocked doctors: Four years of treatment with combination estrogen and progestin pills failed to lower the risk of new heart attacks in women who already had heart disease.
While some physicians immediately stopped putting their elderly heart patients on long-term hormone replacement, many others have simply refused to believe the results.
The latest report backs up HERS' disturbing conclusion. It studied post-menopausal women with heart disease to see if hormone replacement slows the buildup of fatty deposits in their heart arteries, the major underlying cause of heart attacks. It, too, found no benefit from hormones.
``These results are indeed somewhat surprising in view of the large body of evidence indicating that estrogen does have a favorable effect on cholesterol and heart disease,'' said the study's director, Dr. David Herrington of Wake Forest University Baptist Medical Center in Winston-Salem, N.C.
``We can't say for certain there is no benefit, but we can rule out a large effect,'' he said. Herrington presented the results in Anaheim at the annual scientific meeting of the American College of Cardiology.
The results are unlikely to settle the question.
Dr. Sidney Smith of the University of North Carolina, a spokesman for the American Heart Association, noted that neither HERS nor the latest study shows whether hormone replacement helps if begun early in menopause or before women develop heart disease.
The answer to those questions should come from the federally sponsored Women's Health Initiative, which is examining the effects of hormone replacement on more than 27,000 women ages 50 to 79. The first results are expected in about five years.
Weighing the risks and benefits of estrogen is already complex. Many women use it for a few years to relieve hot flashes and other ill effects of menopause. Others stay on the hormone for many years to improve cholesterol levels and to prevent brittle bones and vaginal changes, even though the treatment can also increase the risk of breast cancer.
Now doctors are clearly confused and divided over what to expect from estrogen on the heart. However, many agree that even if the hormone proves to be good, its benefit is unlikely to be as large as that of statin drugs, which clearly lower cholesterol and save lives.
In Herrington's study, sponsored by the National Institutes of Health, 309 older women with heart disease were randomly assigned to Premarin, the estrogen-progestin combination Prempro or dummy pills. After four years, doctors measured their heart arteries and found no difference in the progression of their disease.
Dr. Marion Limacher of the University of Florida said that until recently, she routinely recommended estrogen supplements for older women with heart disease. Now she takes them off hormone replacement, largely as a result of HERS.
Nevertheless, she said, ``some doctors discount HERS as flawed or not to be believed.''
However, Dr. Michael H. Davidson of the Chicago Center for Clinical Research said estrogen may still turn out to be good for many women's hearts. He presented evidence that estrogen plus a statin lower cholesterol more than does a statin alone.
``We have several years to go before we know which women will benefit from hormone replacement therapy and which ones should avoid it,'' Davidson said.