Intravenous dopexamine in the treatment of acute congestive heart failure: Results of a multicenter, double-blind, placebo-controlled withdrawal study

Acute hemodynamic effects of intravenous infusion of dopexamine were evaluated by a placebo-controlled withdrawal study in patients with acute congestive heart failure. Twenty patients were enrolled at 10 centers in Japan. All patients had a pulmonary capillary or diastolic pressure of 15 mmHg or greater and a cardiac index of 2.5 l/min/m2 or less.Phase I: Intravenous dopexamine was introduced in a single-blind, uncontrolled fashion at the rate of 0.5 µg/kg/min and was titrated up to achieve a 30% or more increase in the cardiac index. Two patients withdrew from the study due to sinus tachycardia and ventricular ectopy or exacerbation of heart failure.Phase II: The remaining 18 responders who were free of limiting side effects were randomized in double-blind fashion to continue dopexamine or to switch to placebo for an additional 60 minutes. At the end of phase II, the hemodynamic improvement obtained in phase I of the study disappeared completely after substitution of placebo but was maintained in dopexamine-treated patients. Our findings suggest that dopexamine, when given in appropriate doses to selected patients, shows balanced vasodilator action suitable for the treatment of acute congestive heart failure.