Additive effects of milrinone and dobutamine in severe heart failure

The hemodynamic effects of dobutamine, milrinone, and a combination of both drugs were compared intra-individually in 14 patients with severe heart failure (NYHA III: n = 9; NYHA IV: n = 5). Dobutamine (maximum dose: 9 micrograms/kg/min) and milrinone (0.5 micrograms/kg/min) each induced a comparable increase in stroke volume index (21 to 29 resp. 21 to 30 ml/m2; mean values; p less than 0.001) and reduction in pulmonary capillary wedge pressure (29 to 22 resp. 28 to 21 mm Hg; p less than 0.001), as well as in systemic (1846 to 1218 resp. 1858 to 1276 dyn s/cm5; p less than 0.001) and pulmonary vascular (301 to 195 resp. 293 to 216 dyn s/cm5; p less than 0.001) resistances. The heart rate rose significantly after dobutamine (92 to 107 min-1; p less than 0.05), but did not change after milrinone (94 to 95 min-1; ns). Neither drug had a significant effect on systemic arterial pressures. The combination of milrinone and dobutamine induced a further significant rise in stroke volume index (37 ml/m2; p less than 0.01) when compared to either drug alone. The combination also caused an additional fall in pulmonary capillary wedge pressure (14 mm Hg; p less than 0.01), as well as in systemic (799 dyn s/cm5; p less than 0.001) and pulmonary (133 dyn s/cm5; p less than 0.001) vascular resistances. When compared to dobutamine alone, the combined therapy did not significantly change the heart rate and systemic arterial pressures. The combined administration of a beta-adrenergic agonist and a phosphodiesterase inhibitor induces beneficial hemodynamic effects.(ABSTRACT TRUNCATED AT 250 WORDS)