Outcome of Down patients with repaired versus unrepaired atrioventricular septal defect.

Background and aims: Patients with Down Syndrome (DS) are frequently born with an atrioventricular septal defect (AVSD). Surgical repair of the defect aims to minimize mortality and morbidity. However, a surgical intervention, specifically in DS patients, is not without risk and a subgroup of patients underwent only conservative non-surgical treatment. Outcome data of these different approaches are scarce. The aim of this retrospective study was to compare the long-term outcome of DS patients with and without surgery for AVSD. Methods: DS patients registered with AVSD in the hospital's database from January 1980 till December 2020 were selected. Patient characteristics, peri-operative if appropriate, and follow-up data were obtained from the medical files. Results: In total, 72 unrepaired (36 male, 50%) and 134 repaired patients (61 male, 46%) were included. After a maximum of 60 years of follow-up, the all-cause mortality was 45.8% and 17.1%, respectively. Thirty-six percent and 13%, respectively, were labeled as non-cardiovascular death. Mean survival time for unrepaired AVSD was 40.7 years (95% CI 36.1-45.2) and for repaired AVSD 38.5 years (95% CI 35.3-41.6) (Log rank p = 0.465). However, the survival rate 35 years after birth was 62.1% for unrepaired patients versus 81.7% for repaired patients. Mortality rates were the highest the first months after surgical repair. Conclusions: The mean survival rate of Down patients, born with an AVSD, did not differ between repair or not. However, long-term survival rate was higher in patients who underwent surgical repair. Mortality was highest the first months after surgery.