The role of HRT in the prevention of heart disease continues to cause confusion. While the recently published NICE guideline on diagnosis and management of the menopause stated that HRT does not increase the risk of heart disease when started in women aged under 60, it did not recommend the use of HRT to prevent heart disease since the evidence was not conclusive enough.
To add to the debate, a randomised trial looking at the effect of starting HRT within 6 years of the menopause or after 10 years has shown that starting early is beneficial.
The ELITE trial randomised 643 healthy postmenopausal women to take either tablet form of 1mg estradiol 1mg E or placebo. Cyclical Progesterone vaginal gel was included in women who had not had a hysterectomy. Similar numbers of women were in the early postmenopause group (<6 years since menopause) and the late postmenopause group (>10 years since menopause).
Progression of atherosclerosis was assessed by Carotid artery thickness (CIMT) and cardiac CT. 596 women completed the study over a median of 5 years. Slower progression of atherosclerosis assessed by CIMT was shown in the in early postmenopause group but no difference was shown by cardiac CT measurement. No benefit was shown in the late postmenopause group and no effect was found from the addition of progesterone gel.
It was concluded that estradiol appeared to slow the progression of atherosclerosis as measured by CIMT, but only when started within 6 years of the menopause. It is proposed that the vascular effect of estrogen may be lost with prolonged estrogen deprivation, which is consistent with the theory of a “Window of opportunity” whereby early use of estrogen postmenopause may be protective.
Ref Vascular effects of Early versus Late Postmenopausal Treatment with Estradiol. Hodis H et al. N Engl J med 2016;374:1221-1231