Impact of Age and of the Patent Ductus Arteriosus on Pulmonary Hemodynamics in Children with Complete Atrioventricular Septal Defect

Complete atrioventricular septal defect (CAVSD) can lead to the development of pulmonary obstructive vascular disease due to high pulmonary blood flow and pressures. This study aimed to evaluate the changes in pulmonary hemodynamics with aging and with patent ductus arteriosus (PDA) in children with CAVSD. We retrospectively evaluated 137 children (94% with trisomy 21, median age of 195 (25-2963) days, 58.4% female) with CASVD referred to cardiac catheterization from January 2000 to December 2020. Those with associated congenital heart disease, except PDA, had been excluded. They were divided into three age terciles (T1, T2, and T3). Aging was directly associated with higher mean (T1: 34.2 +/- 9.1; T2: 37.1 +/- 5.8; T3: 42 +/- 10.6 mmHg, p < 0.001) and diastolic (T1: 19.4 +/- 5.3; T2 21.6 +/- 5.0; T3: 26.0 +/- 9.5 mmHg, P < 0.001) pulmonary arterial pressures, and with higher pulmonary vascular resistance (T1: 3.24 +/- 1.69, T2: 3.47 +/- 1.19; T3: 4.49 +/- 3.91 Wu.m(2), p = 0.023). This resulted in a loss of eligibility for anatomical correction, which became evident only after 300 days of age. PDA was associated with a higher mean (37.2 [35.9; 38.5] vs. 41.3 [37.5; 45.0] mmHg, p = 0.049) and diastolic (21.7 [20.7; 22.6] vs. 26.4 [24.1; 29.0] mmHg, p = 0.001) pulmonary pressure, and resistor-compliance time (0.28 [0.26; 0.29] vs. 0.36 [0.31; 0.40], p = 0.001) after adjusting for age and sex. In children with CAVSD, aging was associated with worsening of pulmonary vascular hemodynamics, particularly when PDA was associated, resulting in loss of eligibility for anatomical correction after 10 months of age as the first surgical option.