Until recently, the bulk of evidence suggested that hormone therapy protected women from heart attacks. However some recent studies now question whether this is really true. This is an important issue as coronary heart disease is the number one cause of death among women in the United States. This risk increases significantly in the menopause years. Estrogen is thought to play a role in protecting women from heart disease during the reproductive years. It is known that estrogen lowers total and LDL cholesterol (high levels correlate with a higher risk of heart attacks), and estrogen increases HDL cholesterol (associated with a lower risk of heart attack). This coincides with observational data that have shown a nearly 50% decrease in the risk of a heart attack with estrogen use. We now have some new information from three large-scale clinical trials that brings the protective role of estrogen into question.

HERS (The Heart and Estrogen/Progestin Replacement Study): In this study, women with preexisting heart disease who were treated with a combination of estrogen and progesterone did not show a significant difference in the rates of second heart attacks or cardiac death compared to women not even on hormone therapy. A worrisome finding was the increase (from 1% to 2%) of coronary events during the first year of treatment in the hormone group. This increase was not seen after the first year. The investigators of HERS have recommended that hormone therapy not be initiated in women with known heart disease. However, women already receiving hormone therapy for a year or more need not discontinue it, as they may be past the increased risk period.

WHI (Women's Health Initiative): This is another large clinical trial with 20,000 women. In contrast with HERS, this ongoing study is examining the effects of hormone therapy on healthy postmenopausal women without preexisting coronary heart disease. The goal is to determine estrogen's ability to prevent a first heart attack. The study groups receive no hormone therapy, estrogen alone or both estrogen and progesterone together. The study will be completed in 2005, but two years into the study preliminary data indicate that hormone therapy may be associated with a somewhat higher rate of heart attack, stroke and blood clots in the legs or lung. The increased risk was small and less than 1% of women had an adverse event. It is thought that the protective effects of estrogen may take at least three years to show up. The study is continuing and will provide us with additional information.

NURSES' HEALTH STUDY: This is a large prospective study of nurses done over the past 20 years. Data from this study again suggest that postmenopausal women with established coronary heart disease may have a small increased risk of a second heart attack or cardiac death during the first year of estrogen or estrogen and progesterone use.

What Does It All Mean?
Instead of confirming estrogen's role in the prevention of heart disease as hoped for, these recent studies have added some concern about initiating hormone therapy in women with known heart disease and have raised more questions about the true benefits. We hope to have more information over the next few years. In the meantime the decision to use hormone therapy remains highly individual based on symptoms, risk factors and a variety of health conditions. If the only consideration for beginning postmenopausal hormone therapy is prevention of heart disease it may be prudent to look at the many other avenues of prevention such as controlling blood pressure, diabetes and cholesterol, maintaining a healthy weight, getting regular exercise an abstinence from smoking. In women with known heart disease who are not already on hormone therapy careful consideration should be used prior to initiating hormone therapy.

If you are concerned about heart disease and would like to know more about assessing your personal risks and maximizing prevention please call and set up an appointment with one of the Avenues For Health physicians.