Positive inotropic effects of ibopamine in patients with congestive heart failure. A multicenter investigation.
A multicenter double-blind placebo-controlled investigation was carried out in 42 patients with severe congestive heart failure who were given ibopamine (SB-7505), the 3,4-diisobutyryl ester of N-methyldopamine, for a period of 10 days in addition to previous treatment with digitalis and diuretics. Symptoms were evaluated by using a suitable score; some patients were submitted to an exercise test along with other clinical tests. Compared with placebo, ibopamine induced no significant changes in heart rate and arterial blood pressure. Clinical scores were lower after ibopamine than after placebo (p less than 0.01). Functional capacity, defined as the duration (in s) of a maximum symptom-limited exercise test using the ergometric bicycle with a constant 25-W workload, was significantly higher after ibopamine than after placebo (p less than 0.05). So a clear symptomatic improvement was observed after ibopamine in cardiac patients with prolongation of exercise time and reduced clinical scores. In conclusion, the results obtained, along with the slight improvement in the systolic time intervals, indicate that ibopamine is capable of improving cardiac performance in patients with advanced heart failure who display symptoms despite treatment with digitalis and diuretics.