Raloxifene: cardiovascular considerations

Ovarian hormone deficiency status is associated with increased cardiovascular morbidity and mortality, suggesting that estrogen might exhibit a favorable cardiovascular effect. Estrogen has a multitude of beneficial biological effects on surrogate markers of cardiovascular disease that may account for this hypothesis. However, none of the randomized trials already conducted with hormone replacement therapy showed overall benefit by means of reducing clinical ischemic cardiovascular events and/or suppressing atherogenesis. Moreover, the Women's Health Initiative study (WHI) has suggested a possible detrimental effect for hormone replacement therapy including increased cardiovascular morbidity, ovarian and breast cancer. Hence, any beneficial effect of estrogen must be carefully weighed against its carcinogenic properties together with its side effects. The need for a more efficient and specific molecule led to the development of the selective estrogen receptor modulators (SERMs). This new generation of drugs mimic the effect of estrogen in some tissues while antagonize several estrogen effects in other tissues. These unique properties offer the possibility to attain the beneficial effects of estrogen while avoiding its carcinogenic effect and the accompanying adverse reactions. Here we review the different effects of raloxifene- a protype second generation SERM on the cardiovascular system. We discuss raloxifene's role at different levels of the atherothrombotic cascade addressing each level separately; trying to clarify the net effect of raloxifene in modulating thrombosis in the arterial tree.