A randomized, open-label, parallel-group design was used to determine the percentage of patients achieving improvements in predetermined baseline hemodynamic end points (>20% to 30% increase in cardiac index depending on baseline values and >25% decrease in pulmonary capillary wedge pressure), assessed at hour 0 (end of initial dose titration) and 1, 2, 4, 8, and 24 hours after the infusion of milrinone or nitroglycerin. In total, 125 patients (60 milrinone, 65 nitroglycerin) enrolled in this study, and 119 (58 milrinone, 61 nitroglycerin) were evaluable for the efficacy analysis. A significantly greater proportion of milrinone-treated patients reached (45% v 14%, P =.005) and maintained (24% v 6%, P =.026) hemodynamic goals than did nitroglycerin-treated patients; the time to achieve hemodynamic goals was significantly less in milrinone-treated patients (33 +/- 2 v 54 +/- 10 minutes, P <.001). Milrinone was also significantly more effective in decreasing systemic vascular resistance (P =.004), increasing stroke volume (P =.008), and improving global clinical status. Inodilator therapy with milrinone seems more efficacious in attaining sustained hemodynamic improvement than does pure intravenous vasodilator therapy with nitroglycerin in treating patients with decompensated heart failure.