Hormones’ protective effect is deceiving

Estrogen loss can bring on heart disease

You’ll be doing your female patients a disservice if you don’t do everything you can to encourage them to lessen their risk for cardiovascular disease by replacing the estrogen lost through menopause.

More cardiologists are recommending estrogen replacement therapy (ERT) for their postmenopausal female patients. ERT carries with it a marginally significant risk of breast cancer. The increased risk of endometrial cancer can be eliminated by the addition of progestin to the regimen. Despite those caveats, the American College of Physicians recommends that all women be encouraged to consider taking preventive hormone therapy.

Disease more prevalent after menopause

Though coronary artery disease occurs in premenopausal women, it becomes substantially more prevalent after menopause, resulting in a lifetime risk similar to that of men. Consistent and extensive data show clear beneficial effects of estrogen on cardiovascular health in women. Various clinical trials as well as observational and epidemiologic studies have shown ERT to be cardioprotective and to be significantly beneficial in women with heart disease.

Its effects include decreased low density lipoprotein, lipoprotein(a), and fibrinogen levels; increased high density lipoprotein and apolipoprotein A-1 levels; and improved endothelial function, vascular compliance, fibrinolytic potential, and antioxidant activity.

Three recent studies focused on components of ERT:

• In a lecture at the American Heart Association’s annual meeting in November, a research team reported that while natural progesterone augments estrogen’s cardioprotective effects, the synthetic version of the hormone may negate it by producing unstable angina.

• ERT appears to improve long-term outcomes in postmenopausal women following percutaneous transluminal coronary angioplasty (PTCA). Investigators in a recent retrospective study concluded that the benefits of ERT are magnified by the patients’ increased risk of cardiovascular morbidity and mortality.1 In addition, those benefits are present even after the clinical appearance of coronary artery disease.

The above-mentioned study assessed ERT’s effects, including restenosis, myocardial infarction, stroke, and death after a first PTCA. Adverse cardiac events are at least as common in women as in men during short- and long-term follow-up after PTCA.

Outcomes in women who had taken estrogen prior to their PTCA and during follow-up were compared to women not taking estrogen. The seven-year survival rate was 93% in the estrogen group vs. 75% in the control group. The treatment group had a lower incidence of cardiovascular events — 12% vs. 35% respectively. The need for follow-up revascularization was similar in both groups.

• Premarin contains three commonly used conjugated equine estrogens. They are all protective but have differing effects on insulin sensitivity and antioxidative activity, say investigators in a recent prospective, randomized, crossover study of healthy postmenopausal women.2 Researchers used doses equivalent to those contained in 1.25 mg Premarin.


1. O’Keefe JH, Kim SC, Hall RR, et al. Estrogen replacement therapy after coronary angioplasty in women. J Am Coll Cardiol 1997; 29:1-5.

2. Wilcox JG, Sevanian A, Hwang J, et al. Cardioprotective effects of individual conjugated equine estrogens through their possible modulation of insulin resistance and oxidation of low-density lipoprotein. Fertil Steril 1997; 67:57-62.