More from the Women’s Health Initiative: Benefits for Estrogen?

 Women who began taking estrogen in their 50s had lower coronary-artery calcium scores than placebo users.

Although initial findings from the Women’s Health Initiative (WHI) indicated substantial risks to use of estrogen in postmenopausal women, a newer study showed no increase in coronary heart disease risks due to hormone therapy for any outcome in women aged 50 to 59 at HT initiation (Journal Watch Apr 10 2007). Now, in a WHI substudy, coronary-artery calcification was assessed in 1064 women who were aged 50 to 59 at randomization to conjugated equine estrogen alone (0.625 mg/day) or placebo; the women underwent computed tomography of the heart after a mean 7.4 years of treatment and 1.3 years after trial completion.

The mean coronary-artery calcium score was significantly lower with estrogen than with placebo. In an analysis restricted to data for women with at least 80% adherence to estrogen or placebo for at least 5 years, the multivariable odds ratios for high levels of coronary-artery calcium were about 60% lower in estrogen users.

Comment: These data support the hypothesis that estrogen therapy has cardioprotective effects in younger women. Accompanying editorialists concur and suggest that estrogen’s effects on the vasculature are mediated in part by age and in part by vascular health at time of estrogen initiation. The findings offer reassurance that estrogen does not increase heart disease risk when used for treatment of menopausal symptoms in healthy women aged 50 to 59 — but the findings do not indicate that estrogen should be used to prevent cardiovascular disease.

Robert W. Rebar, MD

Published in Journal Watch General Medicine June 20, 2007

Citation(s):

Manson JE et al. Estrogen therapy and coronary-artery calcification. N Engl J Med 2007 Jun 21; 356:2591-602.