Immediate postnatal cardiac surgery versus conventional neonatal cardiac surgery for critical congenital heart disease: a propensity score-matched cohort study

Technical Summary: Immediate Postnatal vs. Conventional Neonatal Cardiac Surgery for Critical Congenital Heart Disease

Problem Statement
The optimal timing for cardiac surgery in neonates with critical congenital heart disease (CCHD) remains uncertain. While surgery immediately after birth may reduce exposure to unstable transitional physiology and prevent deterioration, there are concerns that neonates may not be physiologically ready for cardiopulmonary bypass (CPB), potentially increasing perioperative risk. Conversely, conventional care involves postnatal stabilization before surgery, which allows for physiologic adaptation but may expose infants to persistent cyanosis, circulatory instability, and transfer-related risks. Previous observational comparisons have been confounded by variations in anatomy, prenatal diagnosis, institutional practices, and preoperative conditions. This study aims to compare the safety and outcomes of immediate postnatal surgery versus conventional neonatal surgery in a matched cohort.

Methodology

• Study Design: A retrospective, single-center, propensity score-matched (PSM) cohort study conducted at Beijing Anzhen Hospital from December 2022 to March 2026.
• Participants: 117 eligible neonates with CCHD underwent cardiac surgery. The eligible diagnoses included transposition of the great arteries (TGA), pulmonary atresia, severe pulmonary stenosis, and total anomalous pulmonary venous connection (TAPVC).
• Group Definitions:
  • Immediate Postnatal Surgery: Planned surgery performed within hours of birth.
  • Conventional Neonatal Surgery: Surgery performed after initial postnatal stabilization.
• Matching Strategy: Propensity score matching was performed using the following covariates: sex, body length, birth weight, prematurity, Risk Adjustment for Congenital Heart Surgery-1 (RACHS-1) category, diagnosis category, prenatal diagnosis status, and inborn status. This resulted in 24 matched pairs (48 neonates total).
• Outcomes:
  • Primary/Secondary Clinical Outcomes: Postoperative adverse events (major complications prolonging hospitalization or causing deterioration), in-hospital mortality, and operative metrics (CPB time, aortic cross-clamp time, vasoactive-inotropic score, mechanical ventilation duration, ICU stay).
  • Long-term Outcome: Freedom from post-discharge unplanned reintervention (catheter-based or surgical procedures for residual/recurrent disease), analyzed via Kaplan-Meier estimation and Cox proportional hazards regression.

Key Results

• Baseline Characteristics: After matching, the groups were well-balanced regarding diagnosis, prenatal diagnosis status, and inborn status. There were no significant differences in body length, birth weight, prematurity, or RACHS-1 categories.
• Operative and Early Postoperative Metrics:
  • Surgical Duration: CPB time (188.5 vs. 212.5 min, P=0.212) and aortic cross-clamp time (125.0 vs. 129.0 min, P=0.700) were statistically similar.
  • Recovery Metrics: Mechanical ventilation time (93.8 vs. 94.0 h, P=0.584) and ICU stay (10.5 vs. 14.5 days, P=0.279) showed no significant difference.
  • Physiologic Support: The vasoactive-inotropic score was numerically higher in the immediate group (9.28 vs. 5.64) but not statistically significant (P=0.170).
• Clinical Outcomes:
  • Adverse Events: Occurred in 25.0% (6/24) of the immediate group vs. 33.3% (8/24) of the conventional group (P=0.791).
  • Mortality: In-hospital mortality was 8.3% (2/24) in the immediate group and 12.5% (3/24) in the conventional group (P=1.000).
  • Reintervention: Post-discharge unplanned reintervention occurred in 4.2% (1/24) of the immediate group versus 20.8% (5/24) of the conventional group (P=0.125).
• Statistical Modeling: Kaplan-Meier analysis indicated a numerically higher freedom from reintervention in the immediate group, though the difference was not statistically significant (log-rank P=0.122). Cox regression yielded a hazard ratio of 0.22 (95% CI 0.03–1.86; P=0.163) for the immediate group, suggesting a lower but non-significant hazard of reintervention.

Key Contributions

1. Feasibility Demonstration: The study demonstrates that immediate postnatal cardiac surgery is feasible in selected neonates without increasing perioperative risks (mortality, adverse events, ventilation time, or ICU stay) compared to conventional stabilization strategies.
2. Rigorous Matching: By matching on RACHS-1 category, diagnosis, and prenatal/inborn status, the study reduced confounding variables that typically plague observational timing studies, allowing for a more direct comparison of surgical timing strategies.
3. Reintervention Analysis: The study uniquely analyzed post-discharge unplanned reintervention as a time-to-event outcome, addressing the limitation of crude rates when follow-up durations differ between groups.

Significance and Claims
The authors conclude that for selected neonates with critical congenital heart disease, immediate postnatal surgery is a viable strategy that does not carry a higher perioperative risk than conventional neonatal surgery. The observed reduction in unplanned reintervention rates with immediate surgery is described as "hypothesis-generating" rather than conclusive.

The paper emphasizes that surgical timing is not merely an operative variable but a marker of the surrounding care system. The success of the immediate pathway relies on a coordinated perinatal approach involving prenatal diagnosis, delivery planning, and immediate access to specialized cardiac anesthesia, perfusion, and intensive care. The authors explicitly state that these results do not support immediate surgery for all neonates; rather, timing should be individualized based on hemodynamic status, extracardiac disease, and institutional capabilities. The study calls for larger, multicenter studies with longer follow-up and standardized timing definitions to confirm the potential benefits regarding reintervention rates.