Hormone replacement therapy (HRT) and ischaemic heart disease: getting to the heart of the matter.

Numerous observational studies have previously shown that estrogen therapy (ERT) or estrogen/progestin hormone replacement therapy (HRT) can significantly reduce the risk of Coronary Artery Disease (CAD) in healthy postmenopausal women by up to 50%. However, due to statistical limitations inherent in these earlier studies, several large randomised trials are now under way. The results from some of these randomised trials are expected sometime in 2005 and will certainly help confirm or refute the present perceived cardio-protective effects of ERT/HRT in healthy menopausal women. On the other hand, the role of hormonal therapy in menopausal women with established CAD is more controversial. Although results from earlier observational trials have been encouraging, more recent randomised controlled data from the Heart and Estrogen/Progestin Replacement (HER) study and the Estrogen Replacement and Atherosclerosis (ERA) study have been more sober. In fact, both have generally reported on the failure of ERT/HRT to reduce the overall rate of ischaemic cardiovascular events or to halt the progression of coronary atherosclerosis in menopausal women with established CAD. However, these studies are not without their own limitations. As such, more future trials will be needed before the role of postmenopausal hormone therapy in the secondary prevention of CAD can be firmly established.