Huge study questions HRT‚s role in heart health

The assumption that hormone replacement therapy helps prevent heart disease may be false, according to preliminary results made available in the midst of a US study of 27 000 healthy postmenopausal women.

Investigators with the National Institutes of Health (NIH) Hormone Replacement Therapy Study found that women taking estrogen were having slightly more heart attacks, strokes and blood clots in their legs and lungs than those taking the placebo. Less than 1% experienced these problems and the initial increased risk seemed to go away after the first 2 years of hormone treatment.

The acting director of the trial, Dr. Jacques Rossouw, said that even though it is too soon to say whether the increased risk of heart attacks and strokes will hold up as the trial continues, he felt morally obliged to inform participants of the findings. Each study participant received a letter informing her of the initial findings. The NIH recommends that the trial continue fully and that women in it remain and continue taking therapy.

Ten million American women take HRT, which has long been touted for its heart-protecting qualities. Studies comparing heart attack rates in women taking HRT with those who did not have consistently found lower rates of heart disease in those taking the hormones. However, these studies didn‚t consider the fact that women who take hormones tend to have a lower risk of heart disease anyway. They are also less likely to smoke and more likely to exercise and have a healthy diet.

Participants in the Women‚s Health Initiative study, who are being followed for 8 to 12 years, have clinic visits every 6 months to assure safety and assess their health. The study tests whether long-term HRT reduces coronary heart disease and fractures without increasing the risk of breast cancer.

A study published by JAMA in August 1998 found that HRT for postmenopausal women with heart disease did not prevent further heart attacks or death from coronary heart disease. The Heart and Estrogen-Progestin Replacement Study (HERS) involved 2763 women, who were treated for about 4 years.