Postcardiac surgery low cardiac output syndrome: dopexamine or dopamine?

Objective: To compare the efficacy and safety of dopexamine with dopamine in the treatment of low cardiac output syndrome after cardiac surgery. Design: This was a multicentre, double-blind, randomised, parallel-group study conducted in intensive care units at centres in Holland and Belgium. Patients were randomised to receive dopexamine (up to 2.0 μg/kg per min) or dopamine (up to 6.0 μg/kg per min) for 6 h after low cardiac output syndrome was confirmed. Results: 70 patients were enrolled (35/group) and there was no significant difference in the operative procedures or haemodynamics at entry into the study. Clinical efficacy, defined as a cardiac index > 2.5 l/min per m² with urine production > 0.5 ml/kg per h and stable haemodynamics for two consecutive readings 1 h apart, was achieved by 90 and 87 % of patients in the dopexamine and dopamine groups, respectively. However, more patients maintained clinical efficacy over the 6-h period in the dopexamine group, which was statistically significant at 1–2 h and approached significance at all other time points. Safety was assessed by comparing the adverse events and concomitant medication. Fewer patients on dopexamine had cardiac events compared with dopamine-treated patients (25 vs 38 events), although there was no difference in the pattern of rhythm disturbance. Fewer patients in the dopexamine group required concomitant vasodilating drugs (18 vs 30). Conclusion: Taking the proportion of patients achieving clinical efficacy, the time to achieve it and the maintenance of it along with the adverse event profile, dopexamine was shown to be an effective and safe drug to use in the management of low cardiac output syndrome after coronary artery bypass graft surgery and may be superior to dopamine. Received: 19 November 1996 Accepted: 8 July 1997