Estrogen for Unstable Angina

OB/GYN News, June 15, 2001 by Sally Koch Kubetin

Acute estrogen with or without progesterone doesn't curb recurrent myocardial ischemia in postmenopausal women with unstable angina, Dr. Steven P. Schulman reported at the annual meeting of the American College of Cardiology.

His hypothesis that it would do so seemed reasonable, Dr. Schulman explained, since endothelial dysfunction is a hallmark of unstable angina, and prior studies in postmenopausal women in the cardiac catheterization laboratory had shown that acute estrogen therapy causes coronary vasodilation, increased coronary blood flow, and reversal of acetyicholine-induced endothelial dysfunction.

The theory was tested in a trial in which 293 postmenopausal women on standard anti-ischemic therapy while hospitalized for unstable angina were randomized to 1.25 mg of IV conjugated estrogen over 30 minutes followed immediately by 1.25 mg/day oral conjugated estrogen for 21 days, or intravenous estrogen followed by oral estrogen plus 2.5 mg/day medroxyprogesterone for 21 days, or placebo.

The primary study end point was the incidence of ischemic events by ambulatory ECG over 48 hours. The mean number of such events was 0.86 in the estrogen-plus-progesterone group, 0.74 with estrogen-plus-placebo, and 0.74 with double placebo, reported Dr. Schulman of Johns Hopkins University, Baltimore.

Symptomatic in-hospital myocardial ischemia occurred in 52.1% of the estrogen/progesterone group, 39% with estrogen-plus-placebo, and 42.4% with double placebo. In-hospital mortality occurred in 5.3% on estrogen/progesterone, 5% with estrogen only, and 3% with placebo.