The impact of morphological characteristics on late outcomes in patients born with hypoplastic left heart syndrome†.

OBJECTIVES: Patients with hypoplastic left heart syndrome are at high risk of late adverse events after Fontan completion, but it is unclear whether their morphological characteristics influence these outcomes. METHODS: Retrospective review of the data from the Australian and New Zealand Fontan Registry identified 185 patients with hypoplastic left heart syndrome who survived to hospital discharge after Fontan completion. Their outcomes were reviewed to identify predictors of adverse events with a particular focus on the impact of morphological characteristics. All available echocardiographic parameters were collected, and the hypoplasia of the left ventricle was subjectively considered to be mild, moderate or severe. RESULTS: The mean follow-up after the Fontan procedure was 6.4 ± 4.7 years. The median age at Fontan procedure was 4.41 years, 95% (176/185) of patients underwent an extracardiac conduit Fontan procedure and 71% (132/185) of those were fenestrated. At 15 years after Fontan, freedom from death and cardiac transplantation was 90% [95% confidence interval (CI) 85-97], freedom from Fontan failure was 78% (95% CI 70-87) and freedom from adverse events was 32% (95% CI 22-46). Morphological parameters did not influence transplant-free survival or Fontan failure. Independent risk factors predicting higher incidence of adverse events included aortic atresia (P = 0.003). CONCLUSIONS: The long-term survival of Fontan survivors with hypoplastic left heart syndrome is excellent and appears comparable to that of the general Fontan population. However, intrinsic morphological characteristics may continue to burden patients with late morbidity.