Hormone Therapy And The Progression Of Coronary-Artery Atherosclerosis In Postmenopausal Women

Two recent studies were reported in the same issue of the New England Journal of Medicine (8/7/03) looking at the relationship between hormone therapy (HT) and cardiovascular disease in menopausal women.  Yesterday, we discussed the results of the National Institutes of Health (NIH) Women's Health Initiative (WHI) which showed an increased risk of coronary heart disease in healthy postmenopausal women who took combined estrogen plus progesterone for more than 5 years.  Today we'll address the second study on a similar topic by the Women's Estrogen-Progestin Lipid-Lowering Hormone Atherosclerosis Regression Trial Research Group.  This study evaluated postmenopausal women who already had preexisting coronary artery disease,to see if a treatment regimen of 17-estradiol (the endogenous estrogen molecule) either alone or when given concurrently with medroxyprogesterone acetate (Provera™) could slow the progression of atherosclerosis.  Previous studies have shown that a treatment regimen of conjugated equine estrogen with or without continuous administration of medroxyprogesterone acetate (Premarin™ or Prempro™) could not slow the progression of atherosclerosis in similar women.  The question here was whether a different formulation of estrogen would make a difference.  It did not.

This study was a double-blind, placebo-controlled trail in 226 postmenopausal women whose average age was 63.5 years and who had at least one coronary-artery lesion.  The participants were randomly assigned to groups who received either their usual care (the "control group"), estrogen therapy with micronized 17-estradiol alone (the "estrogen group"), or 17-estradiol plus sequentially administered medroxyprogesterone acetate (the "combination estrogen-progestin group"). In all patients the low-density lipoprotein (LDL) cholesterol level was reduced to a target of less than 130 mg per deciliter. The researchers were primarily interested in the average per-participant change in coronary artery stenosis (narrowing) between angiograms taken at the beginning and end of the study.

After an average of 3.3 years, the average change in the percent stenosis was 1.89 percentage points in the control group, 2.18 in the estrogen group, and 1.24 in the estrogen-progestin group.  After statistical analysis, the researchers concluded that in older postmenopausal women with established coronary-arteryathero sclerosis, 17-estradiol either alone or with sequentially administered medroxyprogesterone acetate had no significant effect on the progression of atherosclerosis.

Created: 9/9/2003  -  Donnica Moore, M.D.