Hormone Therapy, Age, and Risk for Heart Disease

Women’s Health Initiative (WHI) data have suggested that the greatest risk for coronary heart disease associated with hormone therapy — with conjugated equine estrogen (CEE) alone or CEE plus medroxyprogesterone acetate (MPA) — might occur in older women. Because the number of younger women with CHD events was small, the WHI researchers pooled data from both arms of the trial, encompassing a total of 27,347 women aged 50 to 79 who were randomized to CEE or CEE/MPA (depending on uterine status) or placebo.

There was a slight, nonsignificant trend toward decreased CHD risk with HT use (compared with placebo) among younger women and those closer to menopause. For example, there was an absolute decrease of 6 CHD events per 10,000 person-years in women within 10 years of menopause, compared with an absolute increase in risk of 17 events for women 20 or more years since menopause, and a decrease of 2 events per 10,000 person-years for women aged 50 to 59, compared with an increase of 19 events for women aged 70 to 79. The trend toward decreased CHD risk in the early years after menopause was driven mainly by event rates in the CEE-alone arm (and not the CEE/MPA arm). Risk for stroke increased significantly across all categories of age and time since menopause (absolute increase, 9 events per 10,000 person-years).