a national register study- recently published Danish study
This is a large non-randomised Level 3 observational study1 that was unable to collect important information on age at menopause and confounding from major cardiovascular risk factors e.g smoking, BMI, exercise etc. This limits its interpretation.
However, overall it showed no increase in CVD in women who chose to take HRT presumably for symptom relief from near menopause. This is reassuring and in contrast to studies where HRT was started on average 13-14 years after menopause eg the WHI and WISDOM RCTs and there was a risk of early cardiovascular harm in the oldest women started on combined HRT in their 70's. The nomal time to commence HRT does not have this risk.
It is difficult to interpret the small increase in the 51-54 age group as the comparison group not on HRT at this age may not have been post-menopausal, oestrogen deficient and would be protected by their later menopause.
Similarly, the apparent benefit of cyclic HRT over continuous HRT may have been due to the usual use of cyclic HRT at perimenopause and continuous therapy post menopause and thus reflect a perimenopausal window of cardioprotection as well as the possible advantage from a reduction in the days on progestogen.
The reduction in CVD seen in this study with non-oral regimens and oestrogen-only regimens is in keeping with other data that progestogens may detract from the putative cardio protective effect of oestrogen and that non-oral routes are not thrombogenic and therefore a better option in the obese or those with known thrombophilia who are the main risk groups for thromosis on HRT.
The bottom line of this study is that HRT from near menopause does not increase overall risk of myocardial infarction but the design of the study could not examine if there was a window around menopause where HRT may be cardioprotective. This will require a long-term RCT from perimenopause.
Meantime, tailoring HRT to the individual can maximise the benefits and minimise the risks."
Commentary by
Professor Alastair H. MacLennan
Reference
1. Løkkegaard E, Andreasen AH, Jacobsen RK, Nielsen LH, Agger C, Lidegaard Ø.
Hormone therapy and risk of myocardial infarction: a national register study.
Eur Heart J. 2008 Nov;29(21):2660-8. Epub 2008 Sep 30. http://eurheartj.oxfordjournals.org/cgi/content/abstract/ehn408
Content Updated 6 October, 2008
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