A Safety and Efficacy Study of Tolvaptan Following Open Heart Surgery in 109 Cases

This study was conducted to evaluate the safety and efficacy of tolvaptan following open heart surgery.We retrospectively reviewed 109 patients who were administered tolvaptan following open heart surgery between August 2011 and July 2014. We divided the patients according to their urine output index (amount of urine output/body surface area) into tertiles as follows: T1 (low responders; n = 36), T2 (intermediate responders; n = 36), and T3 (high responders; n = 37). No fatal adverse events were observed following tolvaptan administration. The factors that showed a significant difference among the 3 groups were body surface area (BSA) and preoperative body weight. Body weight rapidly decreased and a greater increase in the serum sodium level was observed on day 1 in the T3 group than in the other 2 groups. No decrease in blood pressure and no significant differences in the occurrence of atrial fibrillation were observed among the 3 groups during tolvaptan administration.Tolvaptan can be safely and effectively administered to increase the urine output without adversely affecting the cardiovascular system or renal function following open heart surgery. However, careful attention is required regarding the possibility of a rapid increase in the serum sodium level so it is important to monitor changes in serum Na levels.