P2.028: Postoperative Complications in Children with Congenital Heart Disease: A National Competing-Risks Analysis (2017-2018)

Background: Survival of children with congenital heart disease (CHD) has improved with advances in cardiac surgery, but survivors remain at risk for long-term complications. Limited data exist regarding the incidence of key postoperative outcomes in this population. We aimed to determine the cumulative incidence of major clinical outcomes after CHD surgery in a large multicenter cohort.

Methods: We conducted a retrospective observational study using the TriNetX USA Collaborative Network. Pediatric patients ( < 18 years) with CHD who underwent cardiac surgery (atrial or ventricular septal defect repair, Fontan procedure, tetralogy of Fallot repair, Norwood procedure, bidirectional Glenn shunt, or coarctation of the aorta repair) between January 2017 and January 2025 were identified. A 20-year look-back period was utilized to capture prior history, and follow-up was available through January 2025 (up to 8 years post-surgery). Patients with Down syndrome, muscular dystrophies, or other genetic/metabolic syndromes were excluded. A competing-risks analysis was performed to estimate cumulative incidence of major postoperative outcomes, treating death or alternative outcomes as competing events. Key outcomes included arrhythmias, heart failure, pulmonary hypertension (PH), failure to thrive (FTT), renal dysfunction, and developmental delays.

Results: A total of 49,600 children met inclusion criteria across 63 health care organizations. The mean age at surgery was 8±5 years, 51% were male, and 59% were White. During the follow-up period, a substantial burden of complications was observed.
Arrhythmias had the highest cumulative incidence over time, reaching 15% by 8 years after surgery. FTT occurred in approximately 10% of patients by 8 years. By the end of follow-up, cumulative incidence of heart failure and PH was 8–9% each, and developmental delays around 8%. In contrast, renal dysfunction was less frequent (2%), and new diagnoses of chromosomal anomalies occurred in 3% of the cohort [Figure 1]. A summary of outcome event counts and 8-year cumulative incidences is provided in Table 1.

Conclusion: Children with CHD who undergo cardiac surgery face significant long-term risks of both cardiac and non-cardiac complications. Arrhythmias and growth failure were the most common adverse outcomes in this large cohort. These findings highlight the need for ongoing surveillance and multidisciplinary care to address long-term complications in pediatric CHD survivors.