941-16 Beneficial Effects of OPC-18790 on Mechanoenergetics in Patients with Idiopathic Dilated Cardiomyopathy

OPC–18790 is a novel inotropic agent which works partially by inhibiting phosphodiesterase without a positive chronotropic effect. The purpose of this study was to examine the effects of OPC–1 8790 on mechanoenergetics in patients with idiopathic dilated cardiomyopathy (DCM) in comparison with the effects of dobutamine. Twenty patients with DCM (LVEF<50%) received either OPC-18790 infusion (5–10μg/kg/min, n=10), or dobutamine (2.5–5μg/kg/min, n=10). Measurements of heart rate (HR), left ventricular enddiastolic volume index (LVEDVl), left ventricular end-systolic elastance (Ees), effective arterial elastance (Ea), myocardial oxygen consumption (MVO2), external work (EW). and pressure-volume area (PVA) were obtained by using conductance catheter and Webster catheter before and after administration of each drug.OPC-18790DobutaminebeforeafterbeforeafterHR(min-1)79±485±679±597±5***LVEDVI(mL/m2)126±11109±7**150±7141±11Ees(mmHg/mL)1.73±0.312.48±0.48*0.72±0.091.42±0.18***Ea(mmHg/mL)2.17±0.271.79±0.222.16±0.222.44±0.44MVO2(J/beat)4.51±0.663.61±0.62*516±0.747.27±1.30**EW(J/beat)0.70±0.060.65±0.100.90±0.111.09±0.13**EW/PVA(%)41.4±3.459.6±5.1**30.3±2.947.0±5.0***EW/MVO2(%)17.4±2.321.0±3.0*20.3±3.017.9±2.6*mean value±SEM*p<0.05**p<0.01***p<0.001 vs beforeOPC–18790 decreased MVO2and improved mechanical efficiency partially due to an adequate balance between inotropic and preload reducing effect. OPC-18790 may be useful for treating patients with congestive heart failure