LAUSR

Introduction: Atrioventricular septal defect (AVSD) is among the most common congenital heart diseases especially in infants with trisomy 21 (T21). However, the clinical outcomes of AVSD are largely limited to institutional reports. Aim: Using U.S.A. national database, the purpose of this study was to a) to assess the prevalence, mortality and outcomes of AVSD, and b) to determine the impact of T21 on its outcomes. Methods: We queried The US National Inpatient Sample from the Healthcare Cost and Utilization Project for patients with AVSD with and without T21 in the period 2002-2017. Patient characteristics, comorbidities, mortality, and healthcare utilization were evaluated for AVSD comparing those with and without T21. Results: During the study period, a total of 20,628,538 infants were born in the in the US, of them 67,020 (0.3%) had AVSD. T21 was diagnosed in 34,825 (52%). The incidence of AVSD ranged from 4.5-7.4/year. Common associated CHD were transposition of great arteries, tetralogy of Fallot, and truncus arteriosus at 10.9%, 4%, 0.4% respectively. The association with CHD was not different between AVSD with and without T21. During study period, 92% of patients underwent surgical repair. AVSD patients with T21 had greater mortality (4.4% vs 1.1%, p<0.001) more frequent pulmonary hypertension (4.8% vs 2.7%, p<0.001), longer median length of hospital stay (7 vs 3 days), and less incidence of arrhythmia (2.8% vs 6%, p<0.001). Comparisons between AVSD with and without T21 are outlined in table 1. Conclusion: Almost half of infants with AVSD had T21. T21 is associated with greater mortality and pulmonary hypertension, longer hospitalization and less arrhythmia.