AMRINONE - NEW NON-GLYCOSIDIC, NON-ADRENERGIC CARDIOTONIC AGENT EFFECTIVE IN THE TREATMENT OF INTRACTABLE MYOCARDIAL FAILURE IN MAN

Chronic congestive heart failure not controlled by conventional therapy was treated with intravenous amrinone, a new non-glycosidic, non-catecholamine cardiotonic agent. Eight patients with New York Heart Association functional class III-IV symptoms were hemodynamically monitored. At peak effect, cardiac index (CI) increased from 1.84±0.32 to 2.74±0.44 l/min/m2 (mean ±SD) (p<0.001) and left ventricular filling pressure (LVFP) decreased from 25.8±6.2 to 19.5±6.8 mm Hg (p<0.05), while heart rate and mean aortic blood pressure did not change significantly. Mean endocardial circumferential fiber shortening (mean Vcf), determined by echocardiography, increased from 0.61±0.27 to 0.89±0.34 circ/sec (p<0.05). The duration of action after bolus infusion varied from 60-90 minutes. During continuous infusion of amrinone, sustained increases in CI and reductions in LVFP, similar to those at the time of peak effect after bolus administration, were maintained for 180 minutes. These marked cardiotonic effects of amrinone in patients already taking digitalis for severe heart failure occurred without side effects of arrhythmias or altered arterial pressures. The fact that the drug is orally active makes amrinone a very promising inotropic agent for the treatment of chronic heart failure in man.