Impact of hypoplastic left heart syndrome anatomic subtype on mortality, ventricular function, and atrioventricular...

The aortic atresia/mitral stenosis (AA/MS) subtype in hypoplastic left heart syndrome (HLHS) has been associated with poor single-ventricle palliation outcomes. We evaluated whether HLHS anatomic subtype influences transplant and Fontan-takedown-free survival and right ventricular (RV) and tricuspid valve (TV) function in the current era.

Retrospective chart review was done for 219 consecutive neonates with HLHS who received a Norwood at our center (2006-2023). Primary outcomes were freedom from mortality/transplant/Fontan takedown post-Norwood (n = 219) and Fontan (n = 133). Moderate or greater RV dysfunction and TV failure were secondary outcomes. Log-rank and Cox regression evaluated primary outcomes; Fine-Gray model assessed secondary outcomes.

Post-Norwood (n = 219), we found that AA/MS was not associated with mortality/transplant/Fontan takedown (log-rank and Cox P = .72), RV dysfunction (Fine-Gray HR, 0.79; P = .33), or TV failure (Fine-Gray hazard ratio [HR], 1.27, P = .34). On multivariable regression, RV dysfunction pre-Norwood (HR, 4.45; P = .008) and genetic syndrome (HR, 2.21; P = .031) were associated with mortality/transplant/Fontan takedown. Post-Fontan, AA/MS was not associated with Fontan failure (log-rank and Cox P = .35), RV dysfunction (Fine-Gray HR, 1; P = .99) or TV failure (Fine-Gray HR, 1.15; P = .74). Aortic stenosis was associated with RV dysfunction (Fine-Gray HR, 2.35; P = .02). On univariate regression, extracardiac anomaly was associated with Fontan failure (HR, 7.25; P = .003). On multivariable regression, TV insufficiency pre-Glenn (HR, 5.4; P = .002) and genetic syndrome (HR, 4.15; P = .036) correlated with Fontan failure.

No association was observed between AA/MS and reduced transplant/takedown-free survival, RV function, or TV failure. Aortic stenosis was associated with increased risk of moderate or greater RV dysfunction post-Fontan. We found that preoperative RV and TV dysfunction, genetic syndrome, and extracardiac anomalies remain risk factors.