Risk Factors for Death or Transplant After Stage 2 Palliation for Single Ventricle Heart Disease.

Background: For infants with single ventricle heart disease, the time after stage 2 procedure (S2P) is believed to be a lower risk period compared with the interstage period; however, significant morbidity and mortality still occur. Objectives: This study aimed to identify risk factors for mortality or transplantation referral between S2P surgery and the first birthday. Methods: Retrospective cohort analysis of infants in the National Pediatric Cardiology Quality Improvement Collaborative who underwent staged single ventricle palliation from 2016 to 2022 and survived to S2P. Multivariable logistic regression and classification and regression trees were performed to identify risk factors for mortality and transplantation referral after S2P. Results: Of the 1,455 patients in the cohort who survived to S2P, 5.2% died and 2.3% were referred for transplant. Overall event rates at 30 and 100 days after S2P were 2% and 5%, respectively. Independent risk factors for mortality and transplantation referral included the presence of a known genetic syndrome, shunt type at stage 1 procedure (S1P), tricuspid valve repair at S1P, longer time to extubation and reintubation after S1P, ≥ moderate tricuspid regurgitation prior to S2P, younger age at S2P, and the risk groups identified in the classification and regression tree analysis (extracorporeal membrane oxygenation after S1P and longer S2P cardiopulmonary bypass time without extracorporeal membrane oxygenation). Conclusions: Mortality and transplantation referral rates after S2P to 1 year of age remain high ∼7%. Many of the identified risk factors after S2P are similar to those established for interstage factors around the S1P, whereas others may be unique to the period after S2P.