Single-ventricular disease with atrioventricular septal defect (AVSD) includes a variety of complex congenital heart defects such as unbalanced AVSD and univentricular hearts with common atrioventricular valve, commonly associated with heterotaxy.

Our objective was to describe hard outcomes (death, transplantation) and their predictors in these defects.

We conducted a retrospective, monocentric review of children with a single ventricle with common atrioventricular valve, who started in a single ventricular repair path between 1968 and 2017.

In total, 161 patients were included: 121 univentricular hearts with heterotaxy syndrome and 40 isolated unbalanced AVSD. Median follow-up was 7.3 years (0–34 years). Prenatal diagnosis had been done in 41.6% patients. Overall mortality was 49%. 24% of patients (39/161) never had surgery with a mortality of 77% at a median age of 1.7 years. Twenty-four percent patients (39/161) had the first stage palliation (Blalock–Taussig shunt 11%, banding of pulmonary artery 11%, other 2%) with a mortality of 69% at a median age of 3.2 years. 26% patients reached the second stage palliation (Glenn surgery) (42/161) with a mortality of 48% at a median age of 8 years, and 26% patients had the third stage palliation (Fontan completion) (41/161) with a mortality of 10% at a median age of 15.6 years. Protective factors were prenatal diagnosis (HR: 0.32, P=0.002) and Fontan stage (HR 0.08, P<0.0001). No risk factor associated with mortality had been identified. Seventy percent of survivors (n=51) were in NYHA functional class I and 78% received at least one cardiac medication.

Outcome of univentricular hearts with AVSD has improved over the last 40 years. However, mortality and morbidity remain high. Patients with prenatal diagnosis and Fontan completion have better survival.