Abstract 17152: Use and Outcomes of the Medical Hybrid Procedure for Stage 1 Palliation in Infants With Hypoplastic Left Heart Syndrome and Variants

Abstract

Background: Staged palliation of hypoplastic left heart syndrome (HLHS) and variants typically begins with the Norwood operation or the hybrid procedure. Hybrid palliation is used in 13% of patients nationally and is often reserved for high-risk patients. A stented hybrid (SH) consists of bilateral pulmonary artery bands (bPAB) and a ductal stent while a ‘medical hybrid’ (MH) consists of bPAB and prostaglandins. MH use and outcomes have not been well described. Hypothesis: MH is used in higher-risk patients and therefore has lower survival than other stage 1 strategies. Aims: Compare use and outcomes of MH, SH, and surgical stage 1 (SS1) using a multicenter database. Methods: Patients from the National Pediatric Cardiology Quality Improvement Collaborative (NPC-QIC) database were categorized by initial intervention: MH, SH, or SS1. Other/unclear procedures were excluded. Results: The study included 2423 patients from 65 centers: 277 (11%) MH, 133 (5%) SH, 2013 (83%) SS1. MH had the lowest birth weight (BW) and gestational age (GA), most non-cardiac anomalies, and most preoperative risk factors (PRF). Most centers performed MH in a minority of cases, though use ranged from 0% to 82% at centers with ≥10 patients. Transplant-free survival at 1 year was 56% for MH, 66% for SH, and 81% for SS1 (p<0.0001). Using multivariable logistic regression, predictors of MH vs SS1 were lower BW (p<0.001), lower GA (p<0.001), genetic syndrome (p=0.010), non-cardiac anomaly (p=0.031), and ≥4/12 PRF (p<0.001). Predictors of MH vs SH were HLHS (p=0.044) and ≥4/12 PRF (p=0.045). Cox proportional hazards regression was used to compare risk-adjusted outcomes, excluding one center that performed >50% SH: MH had higher risk of one-year mortality/transplant compared to SS1 (HR = 1.89, 95% CI 1.47-2.42) and no difference compared to SH (HR = 1.16, 95% CI 0.76-1.79). Conclusions: Survival after MH is similar to SH and worse than SS1. This may be due to patient risk factors not controlled for in this study.