Newswise — Now that the popularity of hormone replacement therapy (HRT) has declined, so too has the number of myocardial infarctions, or heart attacks, in menopausal women each year, a new study has found. There has been no such difference in the rate of strokes, however.
The study, which appears in the May issue of the journal Medical Care, looked at whether the decreased use of HRT has affected the rate of cardiovascular health outcomes.
Before 2002, physicians believed HRT reduced the risk of coronary heart disease by up to 50 percent in menopausal women. As a result, physicians prescribed it broadly to treat many of the symptoms of menopause, as well as to protect women against cardiovascular disease. However, a report by the Women's Health Initiative in 2002 revealed that HRT actually had the opposite effect — it increased the risk of heart attack in these women.
"After the 2002 report, the use of HRT in women aged 50 to 69 declined from more than 30 percent to less than 15 percent," said lead study author Kanaka Shetty, M.D
Shetty, at the RAND Corporation in Santa Monica, and colleagues evaluated data from 1990 to 2005 for women between the ages of 40 and 79. The researchers used U.S. death records, hospital discharge data and national surveys of medication usage.
They found that the decreased use of HRT did not reduce the number of hospitalizations or deaths from stroke. However, it was, linked to a decrease in acute myocardial infarction among women.
The study found that for every 10,000 additional HRT users in one year, there will be 25 more heart attacks. By comparison, the Women's Health Initiative found seven more heart attacks per 10,000 women on HRT in one year.
As for the non-effect on stroke figures, "We were surprised that HRT had such divergent effects on stroke and acute myocardial infarction in the overall population," Shetty said.
Nieca Goldberg, M.D., suggested there might be other reasons for the decline in heart attacks.
"The reduction in hormone therapy coincided with the American Heart Association's and National Heart, Lung, and Blood Institute's women and heart disease awareness campaigns," said Goldberg, a cardiologist at Total Heart Care, in New York City. "The lower rate of heart attacks may be due to better screening for heart disease risk factors in women, more woman scheduling appointments to be screened for heart disease risk factors and better awareness of women's heart attack symptoms by physicians."
Goldberg, whose practice focuses primarily on women, said, "It's premature to attribute the decline in heart attack rates to the decline in hormone therapy."
Shetty KD, Vogt WB, Bhattacharya J. Hormone replacement therapy and cardiovascular health in the US. Medical Care 47(5), 2009.