Milrinone, dobutamine, and nitroprusside: comparative effects on hemodynamics and myocardial energetics in patients with severe congestive heart failure.

To assess their comparative effects on hemodynamics and myocardial energetics, we administered nitroprusside (1.5 +/- 0.6 microgram/kg-min), dobutamine (10 +/- 3 micrograms/kg-min), and milrinone (67 +/- 13 micrograms/kg-min) sequentially to 10 patients with severe (NYHA class III or IV) congestive heart failure. Each agent led to a significant (p = .001) increase in cardiac index (1.9 +/- 0.5 to 2.7 +/- 0.6 liters/min/m2; 1.7 +/- 0.4 to 2.6 +/- 0.6 liters/min/m2; and 1.8 +/- 0.5 to 2.7 +/- 0.5 liters/min/m2, for nitroprusside, dobutamine, and milrinone, respectively). Dobutamine did not produce a significant change in the pulmonary capillary wedge pressure (27 +/- 5 to 24 +/- 6 mm Hg, NS) nor in mean arterial pressure (83 +/- 9 to 86 +/- 10 mm Hg, NS), but caused a significant rise in heart rate (85 +/- 16 to 99 +/- 17 beats/min, p = .001) and in myocardial oxygen consumption (8.7 +/- 2.1 to 11.1 +/- 3.8 ml O2/min, p = .03). In contrast, nitroprusside and milrinone each caused a significant (p = .001) fall in the pulmonary capillary wedge pressure (27 +/- 6 to 19 +/- 7 mm Hg and 26 +/- 6 to 19 +/- 9 mm Hg, respectively), without significantly increasing either the heart rate (87 +/- 18 to 85 +/- 17 beats/min and 86 +/- 17 to 89 +/- 17 beats/min, respectively) or myocardial oxygen consumption (8.8 +/- 2.3 to 7.6 +/- 2.1 ml O2/min and 8.8 +/- 2.1 to 8.4 +/- 2.1 ml O2/min, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of long-term therapy with milrinone and the effects of milrinone withdrawal.

To assess the long-term efficacy of milrinone in patients with severe congestive heart failure, we obtained hemodynamic measurements (systemic arterial and right heart catheterization) in 13 patients at baseline and after intravenous administration of milrinone. After continuous oral milrinone therapy of 8 +/- 4 months duration, repeat hemodynamic study was performed in patients on oral milrinone therapy, after withdrawal of milrinone, and after readministration of milrinone intravenously. Comparison of initial baseline and withdrawal hemodynamic measurements for the group as a whole showed no interval progression of heart failure, as reflected by the pulmonary capillary wedge pressure (27 +/- 8 to 24 +/- 12 mm Hg, NS) or the cardiac index (2.0 +/- 0.4 to 2.1 +/- 0.8 liters/min/m2, NS). Individual comparisons of milrinone-free hemodynamics revealed that five patients had improved hemodynamically, three patients were unchanged, and five patients had deteriorated, four of whom manifested dependence on milrinone with a progressive hemodynamic decline after milrinone withdrawal which required readministration of milrinone on an emergency basis. Continued efficacy of milrinone was observed on readmission after withdrawal: pulmonary capillary wedge pressure fell from 27 +/- 8 to 16 +/- 10 mm Hg (p = .001) initially and from 24 +/- 12 to 13 +/- 11 mm Hg (p = .001) at readministration, while cardiac index rose from 2.0 +/- 0.4 to 2.8 +/- 0.5 liters/min/m2 (p = .001) initially and from 2.1 +/- 0.8 to 2.7 +/- 0.5 liters/min/m2 (p = .005) upon readministration.(ABSTRACT TRUNCATED AT 250 WORDS)