Efficacy and Safety of Tolvaptan in Infants after Open Heart Surgery

Background: Reports on the efficacy of tolvaptan, which is a selective vasopressin V2 antagonist, in infants who undergo cardiac surgery are rare. We evaluated the efficacy and safety of tolvaptan to manage early fluid retention in infants following open heart surgery. Methods: Pediatric patients under the age of 1 year who underwent biventricular repair with CPB were received conventional diuretics. Additionally, tolvaptan was administered in 18 patients two days after the administration of conventional diuretics when conventional diuretics did not effectively control fluid. For the evaluation of the effect of tolvaptan, the cumulative 24-h urine volume was measured. Changes in laboratory values, cardio hemodynamic factors, and all adverse events were also evaluated. Results: The cumulative 24-h urine volume after 1st tolvaptan administration increased significantly compared with the urine volume before the administration (Day 3 vs. Day 4, 56.0 ± 15.0 vs. 84.2 ± 20.6 mL/kg; p=0.0002). Similarly, the cumulative 24-h urine volume after 2nd tovaptan administration were significantly larger than that before the tolvaptan administration (Day 5 vs. Day 3, 85.9 ± 32.2 vs 56.0 ± 15.0 mL/kg; p=0.003). There were no significant differences in hemodynamical factors and laboratory values on the tolvaptan administration. We also found that no adverse events were present. Conclusions: The addition of tolvaptan to conventional diuretics increases urine volume without major adverse events, and could be beneficial to control fluid in infants who underwent open heart surgery.