Impact of Aortic Atresia After Fontan Operation in Patients With Hypoplastic Left Heart Syndrome

Abstract

Background: Patients with aortic atresia have the worst prognosis in the spectrum of hypoplastic left heart syndrome. It remains unknown whether patients with aortic atresia continue to do poorly after Fontan operation. This study aimed to determine the association between aortic atresia and atrioventricular valve (AVV) function and clinical outcomes after Fontan operation in patients with hypoplastic left heart syndrome. Methods: We performed a retrospective study of 1731 patients who survived the Fontan operation from the Australia and New Zealand Fontan Registry between 1975 and 2020. Results: We identified 188 patients with hypoplastic left heart syndrome, including 99 (53%) with aortic atresia. Overall transplant-free survival and freedom from failure of Fontan circulation at 15 years was 91% (95% CI, 86%-96%) and 79% (95% CI, 71%-88%), respectively. The cumulative incidence of AVV operation at 15 years of age for patients with aortic atresia and aortic stenosis was 28% (95% CI, 19%-38%) and 14% (95% CI, 7%-22%; P =.03), respectively. The cumulative incidence of AVV failure (moderate or greater regurgitation or AVV operation) at 15 years of age for patients with aortic atresia and aortic stenosis was 50% (95% CI, 37%-61%) and 30% (95% CI, 19%-42%; P =.01). Patients with AVV failure were at increased risk of having moderately, or worse, decreased systolic ventricular function (odds ratio 6.7; 95% CI, 1.7-33; P =.01) and failure of Fontan circulation (hazard ratio 3.7; 95% CI, 1.5-9.1; P <.01). Conclusions: In patients with hypoplastic left heart syndrome, there is no significant difference in transplant-free survival after Fontan operation between patients with aortic atresia and patients with aortic stenosis. However, patients with aortic atresia have a much higher burden of AVV failure than patients with aortic stenosis. Atrioventricular valve failure is associated with failure of Fontan circulation.