Hormone replacement therapy should not be given to women solely for the purpose of preventing heart disease because the benefits are ambiguous at best, the American Heart Assn. recommended today.
The suggestion from the nation's leading group of heart doctors adds another twist to the complex calculations faced by many of the 50 million American women over age 50 as they ponder whether to use hormone therapy. The suggestions are likely to lead to changes in the advice at least some women receive from their doctors.
"These are good recommendations," said Dr. Howard Judd, chairman of the department of obstetrics and gynecology at the Olive View/UCLA Medical Center in Sylmar. "There has been a huge amount of publicity about estrogen preventing heart disease. . . . Then, as the various trials have been performed, these trials have not supported a protective effect. I think we have to reassess the role of estrogen in preventing heart disease."
As recently as 1995, the heart association recommended that hormone replacement therapy be considered for all women past menopause. In 1999, the organization softened that position, saying the decision for therapy should be tailored to the patient.
Now, the heart association said its recommendation should not lead women to abandon hormone therapy if they are taking it for other reasons that are better substantiated: to reduce hot flashes during menopause, for example, or to prevent osteoporosis.
But many do take the drugs at least in part because of the widespread belief that estrogen combats heart disease, which is the largest single cause of death for women. Recent studies, the heart association says, have not supported the idea that the hormone, taken with or without progesterone, protects the heart in women who have heart disease.
If anything, studies have shown a slight increase of blood clots and heart attacks in the early months of hormone therapy.
As for women who do not already have heart disease, the jury is still out on whether hormone therapy may be beneficial to the heart. There is some evidence of a slightly increased risk in the short term.
Guidelines Called Important Clarification
Over the longer term, there may be a benefit; research on that continues. But given the absence of more data, the heart association recommends that women who do not have heart disease should not take hormone therapy if their only reason for doing so is concern over heart disease.
If women are interested in the therapy for additional reasons, however, the new statement says, it is still reasonable for healthy people to consider a possible benefit to the heart as one factor in making their decision.
Both heart and hormone experts called the new guidelines, published today in the journal Circulation, reasonable and an important clarification of the current state of knowledge surrounding heart disease and estrogen--knowledge that may not have filtered down to many doctors' offices although other groups, including the North American Menopause Society, have made similar recommendations.
Women who are concerned about their hearts should place much more emphasis on strategies that are known to help, such as watching one's diet and weight, avoiding smoking, and (when appropriate) taking medications that lower cholesterol levels or blood pressure, the heart association said. Such strategies are seriously underutilized, said Dr. Lori Mosca, lead author of the new guidelines and director of preventive cardiology at New York Presbyterian Hospital.
"That is what a woman should be focusing on with her physician," Mosca said.
Risk for heart disease increases sharply after menopause, when the body's production of estrogen falls steeply.
The fact that the risk rises as estrogen production declines was one reason that many doctors thought that replacing a woman's natural hormone with a synthetic estrogen would help ward off heart disease.
Then, large epidemiological studies that compared the health of women taking estrogen after menopause with those who did not showed that those taking estrogen appeared to have a 30% to 50% lower risk of heart disease.
But scientists point out that the epidemiological studies are not conclusive. It's always possible that the women who choose to take hormones differ from those who opt not to take them. And the difference, rather than the estrogen, accounts for the lower risk. Women who choose to take estrogen might on average be healthier to begin with, for instance.
And though estrogen does seem to reduce cholesterol levels and increase the elasticity of blood vessels, "that doesn't always translate into an outcome in people," said Dr. Elizabeth Barrett-Connor, professor of epidemiology in the department of family and preventive medicine at UC San Diego.
Some researchers continue to believe that estrogen does provide a benefit for the heart. But several recent clinically controlled studies have cast doubt on that protective role.
For instance, a four-year study of women with preexisting heart disease known as the Heart and Estrogen Replacement Study (HERS) showed no difference in the number of heart attacks in women who took hormones and those who didn't.
Evidence for Change in Treatment Grows
There was, however, a threefold increase in risks of blood clots in hormone users and, in the first year of the study, a 52% increase in the risk of a heart attack in hormone users. As the study went on, that risk subsided.
In another study, known as ERA, taking estrogen alone or with progesterone did nothing to reduce narrowing of blood vessels in women who had heart disease.
"I think we are accumulating an increasingly large body of evidence suggesting that women with heart disease are not benefited from hormone therapy with regard to heart disease," said Dr. David Herrington, professor of cardiology at Wake Forest University School of Medicine in Winston-Salem, N.C. Herrington is a coauthor of the new guidelines and an investigator in the HERS and ERA studies.
Clearer answers for those who do not have heart disease should come in the next decade from studies including the Women's Health Initiative, a $700-million national study of 160,000 women, which, among many goals, is exploring the role of hormone therapy in a wide range of health areas including the brain, heart, bones and cancer.
So far, the first two years of the study have seen a small increase in blood clots among women taking hormones, which was expected, but also a slight, unexpected increase in risk of heart disease and stroke. The extent of the increased risk isn't known because the data have not yet been published, but women taking part in the study have been notified that researchers continue to see the slight increase in risk.
Today's guidelines do not recommend that people doing well on hormone replacement therapy stop taking the drugs, said Mosca. But if they have heart disease and the prevention of heart disease is the only benefit they are seeking, they might want to revisit their options with their doctor, she said.