Heart Disease: HRT and CVD
For many years it was thought that the use of HRT reduced the risk of heart disease and indeed, many women took HRT mainly for that reason.
However, results of some trials, including the Women’s Health Initiative (WHI) trial initially suggested that women who took HRT had an increased risk of heart disease. This finding led to great concern, confusion and loss of confidence in the use of HRT. Since first publication of these results in 2002, further analysis has reassuringly shown that it was only in women who were 20 or more years post-menopause who took HRT in the trial (women who would be very unlikely to take HRT out-with a trial, in the “real” world) who had a small increased risk. Women who were within 10 years of the menopause, had no increased risk and had a trend towards a reduced risk.
There have been many studies showing reasons why the use of estrogen, the main component of HRT, should be beneficial for heart health since it has been shown to reduce LDL cholesterol, increase HDL cholesterol, reduce the deposition of cholesterol in blood vessel walls, and favourably influence the “pear” to “apple” weight distribution.
More recent studies and reviews have now shown that HRT can reduce the risk of cardiovascular disease if started within the early years of the menopause, the "window of opportunity". More studies are needed to examine the effects of different types and routes of HRT, since previous studies have mostly included the use of oral HRT, but in recent years the use of trandermal HRThas increased.
While the main indication for HRT will continue to be for control of menopausal symptoms, the message of HRT also providing benefits for reduced risk of cardiovascular disease when started early in the menopausal years, now seems to be well established.
For women who start HRT for control of persistent symptoms after a gap of around 10 years or more since menopause, or are restarting after stopping HRT some time ago, the only concern about starting after such a gap is that blood vessels may react differently than if HRT was started early. This would not increase the risk of cardiovascular disease, but may not provide the benefit that HRT can provide if started within 10 years of the menopause.
In terms of cardiovascular system, the safest way to start after a gap would be transdermal estrogen (patch or gel) starting with a low dose of estrogen.