Con: Postmenopausal hormone replacement therapy does not improve outcome in women undergoing coronary artery bypass graft surgery

Abstract

CARDIOVASCULAR DISEASE is the leading cause of death in the United States in men and women. Deaths from cardiovascular disease outnumber deaths from all cancers combined and include approximately 500,000 women each year.1 The prognosis for women with coronary heart disease is worse than that for men, with higher mortality for women hospitalized for acute myocardial infarction, angioplasty, and coronary artery bypass graft surgery2-4 (CABG). Although the long-term survival for men and women discharged alive after CABG surgery is similar, the incidence of graft patency and survival free of angina is lower in women than in men.5 Despite the alarming prevalence of coronary heart disease in women, the incidence of coronary artery disease is still higher in men, with women developing atherosclerotic heart disease an average of 10 years later than men.6 This apparent female advantage is thought to be due to the protective effects of estrogen in women before menopause. In the Framingham study,7 researchers showed that the incidence of cardiovascular disease was 40 times higher in women aged 75 to 84 years compared with women aged 35 to 44 years. This ratio was not seen in men and likely reflects the relatively lower incidence of coronary artery disease in premenopausal women. Many observational studies have shown a lower risk of coronary heart disease in women who are taking postmenopausal hormone replacement therapy (HRT) when compared with women who are not, providing evidence to support the influential benefit of estrogen on risk for coronary heart disease. Estrogen raises high-density lipoprotein levels and lowers levels of low-density lipoproteins.8 These changes in lipoprotein profiles account for only 25% to 50% of the reduction in cardiovascular risk, however. Studies have shown evidence for estrogen-related endothelial-dependent vasodilation,9 antioxidant effects,10 and potential influences on coagulation.11 Given this information, it may be postulated that HRT would decrease the risk for recurrent cardiac events in women who have a history of coronary artery disease, resulting in improved clinical outcome. The authors conclusively show evidence against HRT in women with coronary artery disease, however, and illustrate that there is a paucity of data to confirm that this HRT improves outcome after CABG surgery.