Children undergoing cardiac surgery have overall improving survival, though they consume substantial resources. Nationwide inpatient cost estimates and costs at longitudinal follow-up are lacking.

Retrospective cohort study of children <19 years of age admitted to Pediatric Health Information System administrative database with an International Classification of Diseases diagnosis code undergoing cardiac surgery. Patients were grouped into neonates (≤30 days of age), infants (31–365 days of age), and children (>1 year) at index procedure. Primary and secondary outcomes included hospital stay and hospital costs at index surgical admission and 1- and 5-year follow-up.

Of the 99,670 cohort patients, neonates comprised 27% and had the highest total hospital costs, though daily hospital costs were lower. Mortality declined (5.6% in 2004 versus 2.5% in 2015, p < 0.0001) while inpatient costs rose (5% increase/year, p < 0.0001). Neonates had greater index diagnosis complexity, greater inpatient costs, required the greatest ICU resources, pharmacotherapy, and respiratory therapy. We found no relationship between hospital surgical volume, mortality, and hospital costs. Neonates had higher cumulative hospital costs at 1- and 5-year follow-up compared to infants and children.

Inpatient hospital costs rose during the study period, driven primarily by longer stay. Neonates had greater complexity index diagnosis, required greater hospital resources, and have higher hospital costs at 1 and 5 years compared to older children. Surgical volume and in-hospital mortality were not associated with costs. Further analyses comprising merged clinical and administrative data are necessary to identify longer stay and cost drivers after paediatric cardiac surgery.

Data regarding preoperative mortality in neonates with critical CHD are sparse and would aid patient care and family counselling. The objective of this study was to utilise a multicentre administrative dataset to report the rate of and identify risk factors for preoperative in-hospital mortality in neonates with critical CHD across US centres.

The Pediatric Health Information System database was utilised to search for newborns ≤30 days old, born 1 January 2009 to 30 June 2018, with an ICD-9/10 code for d-transposition of the great arteries, truncus arteriosus, interrupted aortic arch, or hypoplastic left heart syndrome. Preoperative in-hospital mortality was defined as patients who died prior to discharge without an ICD code for cardiac surgery or interventional catheterisation.

Overall preoperative mortality rate was at least 5.4% (690/12,739) and varied across diagnoses (d-TGA 2.9%, TA 8.3%, IAA 5.5%, and HLHS 7.3%) and centres (0–20.5%). In multivariable analysis, risk factors associated with preoperative mortality included preterm delivery (<37 weeks) (OR 2.3, 95% CI: 1.8–2.9; p < 0.01), low birth weight (<2.5 kg) (OR 3.8, 95% CI: 3.0–4.7; p < 0.01), and genetic abnormality (OR 1.6, 95% CI: 1.2–2.2; p < 0.01). Centre average surgical volume was not a significant risk factor.

Approximately 1 in 20 neonates with critical CHD suffered preoperative in-hospital mortality, and rates varied across diagnoses and centres. Better understanding of the factors that drive the variation (e.g. patient factors, preoperative care models, surgical timing) could help identify patient care improvement opportunities and inform conversations with families.