One of the proposed benefits of hormone replacement therapy (HRT) is reduced risk of heart attack and heart disease in postmenopausal women. However, some research has suggested that HRT does not provide this benefit. New research in the July 3, 2002 issue of the Journal of the American Medical Association (JAMA) provides more evidence that HRT may not be effective for reducing heart attack risk and heart disease-related deaths in postmenopausal women who already have heart disease.

Related News: The July 17, 2002 issue of JAMA reports that another major study of HRT in postmenopausal women was stopped three years early due to evidence that HRT may increase the risk of breast cancer, heart disease, stroke, and blood clots in the leg veins and the lungs. See: "HRT study stopped early because risks seem to outweigh benefits"

About the study

A group of U.S. researchers, led by researchers at the University of California, San Francisco, analyzed new data from the Heart and Estrogen/Progestin Replacement Study (HERS). The HERS study included 2763 postmenopausal women with heart disease who were younger than 80 and had not undergone a hysterectomy when the study began in 1993-94. Data from the original HERS study suggested that during the first year of HRT, women were at higher risk of heart disease-related events than women taking placebo (inactive pill). However, the data suggested that after three to five years the risk might be lower among HRT users than in the placebo group.

At the start of the original HERS study, participants provided information about their reproductive and health history, medication use, risk factors for heart disease, and quality of life. They also underwent a complete physical exam including breast and pelvic exams, mammography, electrocardiogram (ECG), and cholesterol testing. Women were assigned to take either HRT or a placebo pill each day. The original study included an average of 4 years of follow-up for each woman. This recent analysis included an average of 2.7 more years of follow-up on 2321 of the women. However, at the start of this second phase, women were told which medication they were taking (HRT or placebo) and given the option of discontinuing or switching treatments.

At the end of the study, researchers compared the number of heart attacks and heart disease-related deaths in the HRT group with the placebo group.

Note: This study was funded by Wyeth-Ayerst, the company that manufactures the HRT Prempro.

The findings

Women taking HRT were no less likely to have a heart attack or die of heart disease than women taking placebo. This was true during the final 2.7 years and during the entire 6.8 years of the study.

Although these results are interesting, there are limitations to this study. First, all of the women in this study had heart disease, so these results may not apply to postmenopausal women without heart disease who are trying to prevent it. Second, the fact that some women changed treatment groups for the last phase of the trial reduces the power of the study to detect a persistent or increasing benefit of HRT on heart disease events. Third, although the women were asked about use of other medications that might affect heart disease risk—such as aspirin, cholesterol-lowering drugs, other hormones, and beta-blockers—there’s no way to determine the full effects of these other drugs on the study outcomes. Finally, only one type and dosage of HRT was used in this study so it’s possible that another type or dosage would produce different results.

How does this affect you?

Does this mean that you should rethink your decision to take HRT? That depends on what you take it for. The findings of this study add to mounting evidence that HRT does not prevent heart attacks or death in postmenopausal women with heart disease. In another analysis of the HERS and HERS II studies, HRT was shown to increase the need for gallbladder surgery and the risk of blots clots in the leg veins, which can travel to the lungs and cause a pulmonary embolism. In addition, HRT did not seem to reduce the risk of fractures due to osteoporosis. However, there is some scientific evidence that HRT helps relieve uncomfortable symptoms of menopause, such as hot flashes, insomnia, and vaginal dryness. On a positive note, HRT did not seem to increase the risk of breast cancer.

According to the study authors, their findings lend additional support to recent recommendations that postmenopausal hormone therapy should not be used to reduce the risk of heart disease events in women with heart disease.

Aside from HRT, is there anything women can do to reduce their risk of heart disease and other aging-related diseases after menopause? In an editorial accompanying this study, Dr. Diane Petitti lists medications that may help prevent heart disease, stroke, and osteoporosis:

  • Beta-blockers or aspirin to prevent heart disease events and stroke among women with heart disease or history of stroke
  • ACE inhibitors or aspirin to prevent heart disease in women at high risk for the disease
  • Statin drugs to lower cholesterol levels, which in turn reduces risk of heart disease and possibly stroke
  • Medications to reduce blood pressure, which in turn reduces risk of heart disease and stroke
  • Bisphosphonates and selective estrogen response modifiers (SERMS) to prevent osteoporosis in women with low bone density