Sustained Improvement in Interstage Survival and Outcomes Within the National Pediatric Cardiology Quality Improvement Collaborative

BACKGROUND: Infants with hypoplastic left heart syndrome remain at high risk during the interstage between stage 1 and stage 2 surgical palliations. As a multicenter Learning Health Network, the National Pediatric Cardiology Quality Improvement Collaborate uses collaborative research and improvement to improve hypoplastic left heart syndrome outcomes for infants. We evaluated whether our previously reported improvement in interstage survival from 90.5% to 94.8% was sustained over time. METHODS: Infants enrolled in the National Pediatric Cardiology Quality Improvement Collaborate clinical registry who underwent stage 1 surgical palliation and were discharged home during the interstage period were included. Patient demographics, hypoplastic left heart syndrome anatomic type, and neonatal hospitalization data in phase 1 (2008–2016) and phase 2 (2016–2025) were compared. Statistical process control was used to analyze rates of interstage survival, major adverse event readmissions, and growth failure. RESULTS: A total of 5495 patients (phase 1—2199, phase 2—3296) were enrolled from 77 centers, of which 38.7% were female and 11.2% had a major syndrome. The phase 2 cohort had a higher prevalence of RV-PA conduit (phase 1: 55.2% versus phase 2: 64.3%; P <0.001), lower median NEONATE score (9 versus 3; P <0.001), higher digoxin prescription (28.9% versus 74.7%; P <0.001), and longer median length of stay compared with phase 1 (28 versus 34 days; P <0.001). Improvement in interstage survival noted in phase 1 was sustained throughout phase 2 at 94.8%. Major adverse event readmissions declined early in phase 2 and were maintained (1.74 versus 0.9/100 interstage patients). Adequate growth was statistically different but clinically stable over time (mean weight Z score at stage 2 admission −1.5 versus −1.42; P <0.019). CONCLUSIONS: National Pediatric Cardiology Quality Improvement Collaborate sustained significant improvements in interstage outcomes through continued adherence to improvement processes, collaborative learning, and promoting best practices over time, including utilization of digoxin and NEONATE score.