Despite impressions to the contrary, cardiovascular disease is the leading cause of death among women in the United States, as it is among men. 1 However, myocardial infarction and stroke are uncommon in women until their sixth decade and beyond. Clinicians have long suspected that the delay of a decade or more in cardiovascular disease expression in women relative to men is due to the protective effects of estrogen during a woman’s reproductive years. Women in the Nurses’ Health Study who underwent surgical menopause by bilateral oophorectomy without estrogen replacement had more than twice the risk of subsequent clinically apparent coronary heart disease as postoperative women who received estrogen therapy. 2 In recent years, reports from population-based observational studies of favorable effects of estrogen therapy on cardiovascular morbidity and mortality 3 4 5 have led to enthusiasm for widespread use of estrogen by postmenopausal women for prevention of cardiovascular disease events. The guidelines for estrogen therapy issued by the American College of Physicians include the statement,“Women who have coronary heart disease or who are at increased risk for coronary heart disease are likely to benefit from hormone therapy.” 6

However, any potential cardiovascular benefit of estrogen, in addition to other benefits, such as preservation of bone mass, must be weighed against uterine cancer risks and possible breast cancer risks with prolonged use. 7 8 Indeed, despite widespread publicity in recent years about heart disease in postmenopausal women and the apparent cardiovascular virtues of estrogen, many women consider their risk of heart disease lower than their risk of breast cancer and, importantly, fear the consequences of breast cancer more than the consequences of heart disease. 9 Furthermore, estrogen therapy is associated with side effects in some women, including vaginal bleeding, and is generally not recommended for chronic use by women with a family history of breast cancer. Thus, many postmenopausal women, including those most likely to benefit from estrogen therapy because of established atherosclerosis, 3 10 may be unwilling or unable to take estrogen supplementation for several decades in the absence of menopausal symptoms. A review of the current understanding of the cardiovascular effects of estrogen and lipid-lowering therapies suggests that lipid-lowering therapy might achieve cardiovascular benefits similar to those of estrogen therapy and thus be acceptable to women who cannot take or choose not to take prolonged estrogen supplementation in the absence of menopausal symptoms.