Estrogen plus Progestin and Artery Diseases

December 2003

Findings Summary

The WHI Estrogen Plus Progestin (E+P) study reported in July 2002 that use of E+P increases the risk of heart attack and stroke, in addition to other health effects. Further analyses of the data from this study indicate that E+P neither increased nor decreased the risk of peripheral arterial disease (PAD) in the 16,608 postmenopausal women in the E+P study. These results were published in the medical journal, Circulation (February 10, 2004).
Coronary heart disease is narrowing of the arteries supplying the heart muscle. PAD is a narrowing of arteries throughout the rest of the body, causing poor circulation. PAD may be seen in the arteries of the legs and in the carotid arteries (which carry the blood to the brain). Observational studies had found less narrowing of these arteries in healthy women taking hormones. Other studies of women with preexisting heart disease found that E+P did not reduce the risk of PAD.
From the WHI data, E+P did not prevent blockage of the aorta (the large artery carrying blood from the heart to the rest of the body), the carotid arteries, or the arteries supplying the legs. This lack of effect of E+P was similar among women of different ages and among women with and without health problems like high blood pressure, diabetes, smoking, prior heart disease or PAD.
Women in this trial were randomly assigned to either placebo or estrogen plus progestin (conjugated equine estrogens 0.625 mg and medroxyprogesterone acetate (2.5 mg), also known as Prempro). When the WHI study first began, this was the most commonly prescribed menopausal hormone therapy in the United States for women with the uterus. Because of the overall findings of health risks exceeding benefits, use of these hormones is now generally recommended only for short-term relief of menopausal symptoms.