Intracoronary 17 β -Estradiol and the Inotropic Response to Dobutamine in Postmenopausal Women

BACKGROUND: Gender differences with respect to clinical presentation and outcome of cardiovascular disease have prompted examination of sex-specific factors that may influence cardiovascular physiology and pathophysiology. The rationale for evaluating control of contractility by estrogen derives from preclinical data demonstrating that 17beta-estradiol (17beta-E(2)) can attenuate the myocardial response to adrenergic stimulation. METHODS: The effects of two doses of intracoronary 17beta-E(2) (150 and 300 ng/min) were tested on the left ventricular (LV) inotropic response to intravenous dobutamine in postmenopausal women who had undergone diagnostic cardiac catheterization. Peak positive LV+dP/dt (LV+dP/dt(max)) was obtained from analysis of LV pressure recorded by a micromanometer catheter. RESULTS: The study was terminated prematurely after the manufacturer stopped production of 17beta-E(2), and data from 7 patients who had completed the study were analyzed. Intracoronary 17beta-E(2) had no effect on basal LV+dP/dt(max) (1299 +/- 60 mm Hg/sec [mean +/- SE] at control vs, 1299 +/- 46 mm Hg/sec with 17beta-E(2)). Intracoronary 17beta-E(2) also had no significant effect on the LV+dP/dt(max) response to dobutamine (1672 +/- 95 mm Hg/sec with dobutamine alone vs. 1639 +/- 73 with dobutamine and 17beta-E(2), p = 0.51). CONCLUSIONS: In humans, no evidence of an acute moderate or large effect of 17beta-E(2) on adrenergically stimulated contractility was documented; a small effect size could not be excluded.