Estrogen replacement may increase heart risks for some women

Cardiologists should think twice about prescribing hormone replacement therapy for women who have heart disease, researchers at Duke University Medical Center warned, after concluding their research project recently.

Their study, prepared for the annual meeting of the American College of Cardiology, is the second in a year that finds an association between new use of hormones in women who have previous heart disease and the occurrence of a second cardiac "event," such as a heart attack or unstable angina. This was not seen in women using such hormones before they developed heart disease.

These studies suggest the general message that hormone therapy is good for the hearts of postmenopausal women must be considered further, said Dr. Karen Alexander of the Duke Clinical Research Institute.

"While hormone use has benefits and may still be cardioprotective in women without heart disease," observed Alexander, "women who have heart disease should probably not start using them."

In looking back at a 1996 study of the use of aspirin in heart attack patients, Alexander and her team found that more than 37% of women who started using hormone therapy after their attack were hospitalized for unstable angina within almost a year. That rate of hospitalization was significantly higher than for women who had never used hormones (17%) and those who had used them before their heart attack (21%).

"These data contribute to the evolving understanding of the benefits from hormone use," Alexander said.

A study reported last August was the first clue that women with heart disease should not start hormone replacement therapy (HRT), which consists of daily doses of estrogen for women who have had hysterectomies or estrogen plus the progestin hormone for women with an intact uterus.

The August study, led by the University of California at San Francisco and called the Heart and Estrogen/progestin Replacement Study (HERS), found that hormone therapy appeared to increase the risk of a heart attack, especially in the first year of treatment in postmenopausal women with heart disease.

It concluded that there was no overall cardiac benefit to hormone use in these women during the four years of the trial, and that the risk of heart attacks seemed to increase soon after starting hormones.

SOURCES: "Initiation of Hormone Replacement Therapy After Acute Myocardial Infarction is Associated With More Angina but Less Death/MI During Follow-up," presented at the 48th Annual Scientific Session of the American College of Cardiology, Mar. 10, 1999.