Utility of the NEONATE Score at an Institution that Routinely Performs the Hybrid Procedure for Hypoplastic Left Heart Syndrome

NEONATE score > 17 has been proposed as a risk factor for interstage mortality/cardiac transplant (IM/T) for patients with single ventricle physiology. Hybrid procedure is assigned 6 points, the highest possible score for that surgical variable. Most centers reserve the hybrid procedure for high-risk patients. Goal of this study was to evaluate the NEONATE score at a center that routinely performs the hybrid procedure. Retrospective chart review of patients undergoing the hybrid procedure was performed (2008-2021). Demographics and variables used for the NEONATE score were collected. Maximization of Youden's J Statistic used to determine cohort-specific optimal threshold for patients undergoing comprehensive Stage II procedure (H-CSII) versus those with IM/T (H-IM/T). Total of 120 patients met inclusion criteria (H-CSII = 105, H-IM/T = 15). Gestational age was median 39 weeks (IQR 38, 39) and birth weight was 3.18 kg (2.91, 3.57). No patient was discharged with opiates or required post-operative extracorporeal circulatory support. Optimal threshold, as selected by maximizing Youden's J Statistic, was 22. Score > 22 had a positive predictive value of 0.33 (95% CI 0.12-0.62), negative predictive values of 0.90 (95% CI 0.83-0.95), and accuracy of 0.83 (95% CI 0.75-0.90) for IM/T. At a center that routinely performs the hybrid procedure, value of > 22 had the highest accuracy. This suggests that the hybrid procedure is not necessarily intrinsically a risk-factor for IM/T, but rather patient selection for the hybrid procedure may play a larger role at centers that do not routinely perform this procedure.