Acute hemodynamic effects of a new inotropic agent (OPC-8212) in patients with congestive heart failure.

The acute effects of OPC-8212, a newly synthesized orally effective inotropic agent, were assessed clinically. Eleven patients with moderate congestive heart failure received a single mean dose of 6.5 mg/kg body weight of the drug. Eight hours after administration, the cardiac and stroke work indexes increased by 11% (p less than 0.01) and 20% (p less than 0.005), respectively, with concomitant decreases in the diastolic pulmonary artery (25%, p less than 0.005) and right atrial pressures (33%, p less than 0.01). There were no significant changes in blood pressure or heart rate. The contractile state of the left ventricle was also assessed by the shift of the Starling curve. To construct the function curve, lower body negative pressure was used to regulate the venous return to the heart. An inotropic effect of the agent was confirmed by the shift of this function curve upward and to the left, even when an augmentation of the cardiac output was masked by the marked reduction in preload. The hemodynamic and clinical effects of OPC-8212 were encouraging and the drug appears to be promising for the treatment of congestive heart failure.