Short-term effects of transdermal estrogen replacement therapy on coronary vascular reactivity in postmenopausal women with angina pectoris and normal results on coronary angiograms.

OBJECTIVES: This study sought to analyze the effect of short-term transdermal estradiol treatment on in vivo coronary endothelial function in postmenopausal women with angina and normal results on coronary arteriograms.

BACKGROUND: The incidence of coronary heart disease increases in women after menopause. Estrogen replacement therapy has been associated with a global reduction in cardiovascular disease incidence and mortality. In addition, coronary endothelial dysfunction has been demonstrated in a group of postmenopausal women. It has been shown that intravenous or intracoronary estrogens improve endothelial function in postmenopausal women with coronary atherosclerosis. However, the efficacy of this treatment is unknown in patients with angina and normal coronary arteries.

METHODS: Endothelium-dependent coronary reactivity was analyzed in 15 postmenopausal women with angina and normal coronary arteries at baseline and after 24 h of estradiol transdermal administration (100 microg).

RESULTS: Estradiol concentration increased from 22 +/- 8 pg/ml (mean +/- SEM) at baseline to 76 +/- 13 pg/ml (p < 0.01) at 24 h. At baseline, acetylcholine induced vasoconstriction, with a mean diameter reduction of -23 +/- 6% (p = 0.002). After estrogen treatment, there was no vasoconstriction with acetylcholine, with a mean diameter change of 0 +/- 4%, significantly different from the pretreatment diameter reduction observed (p = 0.003). Similarly, estimated coronary blood flow significantly increased in response to acetylcholine after estrogen treatment, with a mean change of 50 +/- 30% compared with 5 +/- 24% before estradiol administration (p = 0.04).

CONCLUSIONS: Early after transdermal estrogen administration, endothelium-dependent coronary vasomotion is improved in postmenopausal women with angina and normal coronary arteries.