Beneficial effects of amrinone-hydralazine combination on resting hemodynamics and exercise capacity in patients with severe congestive heart failure.

Abstract

The effects of combined administration of low-dose amrinone (100 mg) and hydralazine (75-100 mg) on resting hemodynamics and exercise capacity were studied in 9 patients with severe congestive heart failure. Five patients were in New York Heart Association (NYHA) functional class IV and 4 were in class III. Cardiac index increased from 1.92 .+-. 0.36 l/min per m2 to 3.23 .+-. 0.63 l/min per m2 (P < 0.001). Pulmonary wedge pressure decreased from 23.6 .+-. 4.1 to 15.1 .+-. 4.7 mm Hg (P < 0.001) and systemic vascular resistance from 1666 .+-. 210 to 1063 .+-. 189 dyn-s-cm-5 (P < 0.001). Mean arterial pressure and heart rate were not significantly changed. The onset of action ranged from 30-150 min and the duration of action from 4-6 h after oral administration. When compared with amrinone alone (100 mg) or hydralazine alone (75-100 mg), the increase in stroke volume index and the decrease in pulmonary wedge pressure induced by the combined therapy were significantly greater (P < 0.01). The hemodynamic benefits at rest were associated with an improvement in NYHA functional class in all, but 1 patient during chronic therapy. Exercise capacity (Naughton protocol) increased during the 1st wk of therapy from 6.1 .+-. 4.3 to 10.6 .+-. 5.3 min (P < 0.01). This increase in exercise capacity was sustained or further improved at 3 wk. The hemodynamic effects of low-dose amrinone can be amplified by simultaneous administration of a vasodilator such as hydralazine in patients with severe congestive heart failure. This combined therapy results in a substantial and sustained improvement in functional class and exercise capacity.