Derived from the National Pediatric Cardiology Quality Improvement Collaborative registry, the NEONATE risk score predicted freedom from interstage mortality or heart transplant for patients with single ventricle CHD and aortic arch hypoplasia discharged home following Stage 1 palliation.

We sought to validate the score in an external, modern cohort.

This was a retrospective cohort analysis of single ventricle CHD and aortic arch hypoplasia patients enrolled in the National Pediatric Cardiology Quality Improvement Collaborative Phase II registry from 2016 to 2020, who were discharged home after Stage 1 palliation. Points were allocated per the NEONATE score (Norwood type—Norwood/Blalock–Taussig shunt: 3, Hybrid: 12; extracorporeal membrane oxygenation post-op: 9, Opiates at discharge: 6, No Digoxin at discharge: 9, Arch Obstruction on discharge echo: 9, Tricuspid regurgitation ≥ moderate on discharge echo: 12; Extra oxygen plus ≥ moderate tricuspid regurgitation: 28). The composite primary endpoint was interstage mortality or heart transplant.

In total, 1026 patients met inclusion criteria; 61 (6%) met the primary outcome. Interstage mortality occurred in 44 (4.3%) patients at a median of 129 (IQR 62,195) days, and 17 (1.7%) were referred for heart transplant at a 167 (114,199) days of life. The median NEONATE score was 0(0,9) in those who survived to Stage 2 palliation compared to 9(0,15) in those who experienced interstage mortality or heart transplant (p < 0.001). Applying a NEONATE score cut-off of 17 points that separated patients into low- and high-risk groups in the learning cohort provided 91% specificity, negative predictive value of 95%, and overall accuracy of 87% (85.4–89.5%).

In a modern cohort of patients with single ventricle CHD and aortic arch hypoplasia, the NEONATE score remains useful at discharge post-Stage 1 palliation to predict freedom from interstage mortality or heart transplant.

The National Pediatric Cardiology Quality Improvement Collaborative (NPC-QIC) lacks a rigorous enrollment audit process, unlike other collaborative networks. Most centers require individual families to consent to participate. It is unknown whether there is variation across centers or biases in enrollment.

We used the Pediatric Cardiac Critical Care Consortium (PC4) registry to assess enrollment rates in NPC-QIC for those centers participating in both registries using indirect identifiers (date of birth, date of admission, gender, and center) to match patient records. All infants born 1/1/2018–12/31/2020 and admitted 30 days of life were eligible. In PC4, all infants with a fundamental diagnosis of hypoplastic left heart or variant or who underwent a surgical or hybrid Norwood or variant were eligible. Standard descriptive statistics were used to describe the cohort and center match rates were plotted on a funnel chart.

Of 898 eligible NPC-QIC patients, 841 were linked to 1,114 eligible PC4 patients (match rate 75.5%) in 32 centers. Match rates were lower in patients of Hispanic/Latino ethnicity (66.1%, p = 0.005), and those with any specified chromosomal abnormality (57.4%, p = 0.002), noncardiac abnormality (67.8%, p = 0.005), or any specified syndrome (66.5%, p = 0.001). Match rates were lower for patients who transferred to another hospital or died prior to discharge. Match rates varied from 0 to 100% across centers.

It is feasible to match patients between the NPC-QIC and PC4 registries. Variation in match rates suggests opportunities for improvement in NPC-QIC patient enrollment.

To identify interstage best practices associated with lower mortality, we studied National Pediatric Cardiology Quality Improvement Collaborative centres registry using a positive deviance approach.

Positive deviant and control centre team members were interviewed to identify potential interstage best practices. Subsequently, all collaborative centres were surveyed on the use of these practices to test their associations with centre mortality. Questionnaires were scored using Likert scales; the overall score was linearly transformed to a 0–100-point scale with higher scores indicating increased use of practices. Mortality was based on patients enrolled after a centre’s first year in the collaborative. Centre mortality rates were divided into tertiles. Survey scores for the low mortality tertile were compared with the other tertiles.

For this study, seven positive deviant and four control teams were interviewed. A total of 20 potential best practices were identified, including team composition, improvement practices, and parent involvement. Questionnaires were completed by 36/43 eligible centres, providing 1504 patients for analysis. Average survey score was 50.2 (SD 13.4). Average mortality was 6.1% (SD 4.1). There was no correlation between survey scores and mortality (r=0.14, p=0.41). The one practice associated with the low mortality tertile was frequency of discussion of interstage results: 58.3% of low mortality teams discussed results at least monthly versus 8.4% of the middle and high tertile centres (p=0.02).

Low-mortality centres more frequently discuss interstage results than high-mortality centres. Heightened awareness of outcomes may influence practice; however, further study is needed to understand the variation in outcomes across centres.

Although interstage mortality for infants with hypoplastic left heart syndrome has declined within the National Pediatric Cardiology Quality Improvement Collaborative, variation across centres persists. It remains unclear whether centres with lower interstage mortality have lower-risk patients or whether differences in care may explain this variation. We examined previously established risk factors across National Pediatric Cardiology Quality Improvement Collaborative centres with lower and higher interstage mortality rates.

Lower-mortality centres were defined as those with >25 consecutive interstage survivors. Higher-mortality centres were defined as those with cumulative interstage mortality rates >10%, which is a collaborative historic baseline rate. Baseline risk factors and perioperative characteristics were compared.

Seven lower-mortality centres were identified (n=331 patients) and had an interstage mortality rate of 2.7%, as compared with 13.3% in the four higher-mortality centres (n=173 patients, p<0.0001). Of all baseline risk factors examined, the only factor that differed between the lower- and higher-mortality centres was postnatal diagnosis (18.4 versus 31.8%, p=0.001). In multivariable analysis, there remained a significant mortality difference between the two groups of centres after adjusting for this variable: adjusted mortality rate was 2.8% in lower-mortality centres compared with 12.6% in higher-mortality centres, p=0.003. Secondary analyses identified multiple differences between groups in perioperative practices and other variables.

Variation in interstage mortality rates between these two groups of centres does not appear to be explained by differences in baseline risk factors. Further study is necessary to evaluate variation in care practices to identify targets for improvement efforts.