Affair of the Heart

For years, it has seemed obvious that taking estrogen is good for a woman's heart. Most women don't suffer heart attacks until they've gone through menopause and their bodies no longer produce much of the hormone. But researchers discovered a funny thing when they tried to prove the obvious. Taking estrogen doesn't always protect women against heart disease--and may sometimes make matters worse.

Scientists presented their latest misgivings about estrogen's coronary benefits at last week's meeting of the American College of Cardiology in Anaheim, Calif. In a preliminary analysis of a study of 309 women with heart disease, Dr. David Herrington of Wake Forest University School of Medicine in Winston-Salem, N.C., and his colleagues reported that estrogen, taken by itself or in combination with the drug progestin, had no effect for better or worse on the atherosclerotic plaques in the women's coronary arteries. Their conclusion echoes that of another study of female heart patients, published 18 months ago, that showed that estrogen is no better than a placebo at preventing a second heart attack.

Of course, most women take estrogen (Premarin is the most popular brand) for just a few years through menopause. Nothing in the latest studies suggests that they should stop. The dilemma is over long-term use, which has been proved to prevent osteoporosis, and does wonders for skin tone as well. Unfortunately, over the years, hormone-replacement therapy increases the risk of breast cancer. Many doctors and patients have been willing to take that risk because it seemed there were substantial benefits to the heart.

The latest reports have called that assumption into question. But it's important not to interpret these results too broadly. Herrington's study and its predecessor looked at women who already had ailing hearts. Both followed their patients for a relatively short time--three to four years. It's quite possible that estrogen is better at preventing the onset of heart problems than it is at treating existing disease. We won't know whether that hypothesis is valid for five more years, when a much larger study on the effects of estrogen in healthy women reaches its conclusion.

It's now clear, as Herrington says, that "the whole relationship between estrogen and heart disease is more complex than we thought." The latest studies indicate that the hormone appears to increase some women's chances of heart problems in the first year after they begin taking it. Any positive cardiac benefits become apparent only after three years of therapy. So if you have never taken estrogen and suffer a heart attack, you probably shouldn't start using the drug. But if you have been on estrogen for several years and then have a heart attack, continuing to take estrogen shouldn't hurt and may help your heart in the long run.