Effects of a cardioselective beta1 partial agonist (corwin) on left ventricular function and myocardial metabolism in patients with previous myocardial infarction

Abstract

Corwin is a new selective beta1 partial agonist, able to stabilize the beta1 adrenoceptors at approximately 43 % of their maximal activity. The aim of the study was to determine the effects of this agent in patients with coronary artery disease (CAD) and previous myocardial infarction (Ml). In a first group of 14 patients, corwin increased significantly the peak (+)dPdt (+35%; p < 0.005), the global ejection fraction, and the ejection fraction of abnormally contracting segments (from 20 ± 18 to 26 ± 19%; p < 0.02). Corwin also induced significant decreases in mean systolic (−8%; p < 0.05) and mean diastolic (−38%; p < 0.001) wall stress and accelerated the relaxation rate. In a second group of 11 patients, a metabolic study indicated that neither myocardial oxygen consumption (15 ± 7 versus 15 ± 7 ml/min; difference not significant) nor lactate extraction was modified by the drug. In this group, increases in peak (+)dPdt, acceleration in ventricular relaxation (−8 ms in time constant of isovolumic pressure decrease; p < 0.01), and decreases in left ventricular end-diastolic pressure also were noted after administration of corwin, both under basal conditions and during a cold pressor test. In conclusion, corwin is a positive inotrope which, in patients with CAD and left ventricular dysfunction, improves left ventricular systolic and diastolic function without inducing myocardial ischemia.