Clinical profile, prenatal detection and predictors of outcome of heterotaxy syndromes in Western Australia

Background

Heterotaxy syndromes encompass left and right atrial isomerism (LAI and RAI respectively) and are associated with variable cardiac and non-cardiac anomalies which greatly influence outcomes. RAI is usually associated with complex congenital heart disease (CHD), early surgical intervention and increased mortality. LAI is less commonly associated with complex CHD but can be associated with heart block. The objective of this study was to review the clinical features and outcomes of patients with heterotaxy syndromes in Western Australia (WA).

Methods

A retrospective review was performed of live born patients diagnosed with heterotaxy from 2003 to 2022 in a statewide tertiary cardiac service, representing all cases in WA with a view to compare the outcomes between LAI and RAI at our centre.

Results

30 patients (53% male) were diagnosed with heterotaxy; 16 (53%) with LAI and 14 (47%) with RAI. Overall incidence was 0.48 per 10,000 live births over the defined period. RAI patients were significantly more likely to have an antenatal diagnosis (81.8% versus LAI 28.6%, p = 0.03). Overall, 5-year survival was 56% for RAI and 87% for LAI. No deaths occurred after the first 12 months of life with a median follow-up of 65 months (IQR 114.8). RAI was associated with asplenia (91%), atrioventricular septal defect (91%) and a functionally univentricular circulation (71%). LAI was associated with polysplenia (100%) and complete heart block in 3 patients (19%). Surgical pathways included repair of anomalous pulmonary venous return (45%), Blalock Taussig shunt (60%), bidirectional cavopulmonary connection (50%) and Fontan completion (30%).

Conclusions

Patients with RAI suffer high mortality and early surgical intervention, with few making it to Fontan completion. By comparison patients with LAI have less morbidity and mortality. The management of heterotaxy continues to be challenging due to widely associated cardiac and extracardiac manifestations.