Early outcomes after complete atrioventricular septal defect repair beyond one year of age: a single-centre comparative study

BACKGROUND: Complete atrioventricular septal defect is usually repaired during early infancy, but delayed referral remains common where access to specialised congenital cardiac surgery is limited. OBJECTIVE: To compare early outcomes after repair in patients aged 12 months or younger and those older than 12 months. METHODS: This single-centre retrospective study included 81 patients who underwent repair between 2020 and 2024. All patients evaluated for repair underwent cardiac catheterisation, and those with elevated pulmonary vascular resistance underwent vasoreactivity testing with 100% oxygen and inhaled nitric oxide. In-hospital mortality, major complications, pulmonary artery pressure, atrioventricular valve regurgitation, and perioperative outcomes were compared. RESULTS: Thirty-five patients were aged 12 months or younger and 46 were older than 12 months. Median ages were 8 and 14 months, respectively. In-hospital mortality occurred in 3 of 35 and 4 of 46 patients, respectively. Major complications occurred in 6 of 35 and 11 of 46 patients. No statistically significant differences were detected in mortality, major complications, ventilation duration, ICU stay, pulmonary artery pressure, or early atrioventricular valve regurgitation. Confidence intervals around mortality and major-complication estimates were wide. CONCLUSION: Repair beyond 12 months was feasible in selected patients considered operable after invasive assessment, but in-hospital mortality remained substantial and estimates were imprecise. These findings do not establish equivalence and should not support intentional delay of repair.