Preoperative Administration of Levosimendan to Prevent Low Cardiac Output Syndrome Following Pediatric Cardiac Surgery: A Retrospective Study

Background: Low cardiac output syndrome (LCOS) is a significant cause of postoperative morbidity and mortality in children with congenital heart disease. Prophylactic levosimendan is increasingly used to prevent LCOS, but its superiority to other strategies remains unproven. Based on the pharmacokinetics of levosimendan, we hypothesize that preoperative administration is beneficial for preventing LCOS in a specifically at-risk population. Methods: This is a retrospective single-center cohort study in a tertiary pediatric intensive care unit. All patients under one year of age undergoing surgery for congenital heart disease using cardiopulmonary bypass and receiving levosimendan within 24 h before or after surgery were included and classified into two groups: preoperative and postoperative administration. Results: Overall, 107 patients were included. Fifty-three patients (49.5%) received levosimendan before surgery, with significantly lower mortality, fewer LCOS markers, and lower LCOS scores compared to patients receiving levosimendan after surgery. Although not significant, the use of extracorporeal membrane oxygenation, renal replacement therapy, and temperature control was also lower in the preoperative group. There was no difference in mechanical ventilation duration and length of stay. Conclusions: Preoperative administration of levosimendan seems associated with a lower incidence of LCOS and reduced mortality in high-risk children with congenital heart surgery.