Effects of acute hormone therapy on recurrent ischemia in postmenopausal women with unstable angina

Objectives We tested whether acute hormone therapy reduces ambulatory electrocardiographic ischemia in postmenopausal (PMP) women with unstable angina (UA). Background Endothelial dysfunction contributes to the pathophysiology of UA. Acute estrogen administration improves endothelial function in PMP women with coronary artery disease and increases coronary artery blood flow. Methods Two hundred ninety-three PMP women with UA (mean age 69.7 years), treated with standard anti-ischemic therapy, were enrolled within 24 h of symptom onset. In a double-blind fashion, subjects were randomized to receive intravenous followed by oral conjugated estrogen for 21 days, intravenous estrogen followed by oral conjugated estrogen plus medroxyprogesterone for 21 days or placebo. The primary end point was the number of ambulatory electrocardiographic ischemic events over the first 48 h. Clinical events were also determined over six months of follow-up. Results Electrocardiographic ischemia did not differ among the three randomized groups. The mean number of ischemic events per patient over 48 h was 0.74 for estrogen, 0.86 for estrogen plus progesterone and 0.74 for the placebo groups (p = 0.87). The percentage of patients with ischemic events and the mean duration of ischemia did not differ between hormone- and placebo-treated patients. In-hospital and six-month rates of adverse clinical events were also similar among the three randomized groups. Conclusions Acute hormone therapy does not reduce ischemia in PMP women with UA when added to standard anti-ischemic therapy.