Primary biventricular repair in neonates with borderline left ventricle.

Abstract

Borderline left ventricle (LV) represents a spectrum of defects, from mild to severe left heart hypoplasia, often with other cardiac anomalies. Decision-making regarding primary biventricular (BiV) repair is challenging. We sought to identify risk factors associated with adverse outcome after neonatal primary BiV repair for borderline LV. A retrospective review was undertaken of neonatal primary BiV repair for borderline LV between 2001 and 2022. The primary outcome was composite of death, transplant, conversion to single-ventricle circulation, pulmonary vascular resistance ≥3 Wood units, and left atrial mean pressure >15 mm Hg. Logistic regression was used to identify associations. Secondary outcome was left heart reintervention (LHRI), analyzed using competing risk regression. Risk score to predict probability of composite outcome was developed. Among 238 neonates, 133 (56%) were male. Median age was 6 (4-10) days. Median follow-up was 1.6 (0.3-5.5) years. The composite outcome occurred in 48 (20.2%) patients. In total, 62 (26.2%) patients required LHRI. Mitral valve area z score <-2 (adjusted hazard ratio [aHR], 3.09; 95% CI, 1.33-7.21; P = .009) and endocardial fibroelastosis (EFE) (aHR, 2.91; 95% CI, 1.08-7.87, P = .04) were associated with the composite outcome. LHRI was associated with mitral valve anterior-posterior diameter z score <-2 (aHR, 2.45; 95% CI, 1.27-4.72, P = .007) and EFE (aHR, 2.54; 95% CI, 1.09-5.91, P = .03). Risk scores ranged from 1 (18% predicted risk) to 4 (86% predicted risk). Mitral valve dimensions and EFE presence are associated with adverse outcomes after BiV repair and can guide frequency of surveillance. Risk stratification may assist with decision-making on initial management strategy.