Hormone replacement therapy in postmenopausal women at cardiovascular risk: epidemiology and clinical trials

Whether hormone replacement therapy (HRT) is useful in postmenopausal women in terms of cardioprotection remains controversial. This paper reviews the results of epidemiological studies and clinical trials in postmenopausal w omen at cardiovascular risk. The well-known methodological biases in observ ational studies limit the clinical relevance of the average risk reduction of 50% observed for the primary prevention of CAD. Moreover these results c annot be extrapolated to the European population of postmenopausal women si nce the magnitude of the risk/benefit ratio of HRT may vary considerably be cause of differences with the North American population at least in terms o f the CAD risk factors and the type of HRT used. The lack of prospective ra ndomized clinical trials is also obvious for secondary prevention since the Heart and Estrogen/progestin Replacement Study is the single large randomi zed study published to date that has tested the effects of HRT drugs that a re less commonly used in Europe. The need for European randomized trials of HRT is now more urgent than ever.