Correlation between pulmonary to systemic flow ratio and N-terminal Pro-B-type natriuretic peptide level in children with atrial septal defect

Introduction: Atrial septal defect (ASD) increases pulmonary to systemic flow ratio (Q(p)/Q(s)) which is an important determinant factor for treatment. N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels are correlated with volume overloading of the heart. This study aims to explore the relationship between Q(p)/Q(s) and NT-proBNP levels in children with ASD. Materials and methods: Between January 2010 and December 2023, 464 patients under 20 years old with ASD who underwent cardiac catheterization and received NT-proBNP test were enrolled retrospectively. Baseline characteristics such as sex, body weight, and age were recorded. Q(p)/Q(s) was measured during standardized right heart catheterization according to Fick principle. Results: A significant positive correlation existed between NT-proBNP and Q(p)/Q(s) (R = 0.507, P < 0.001), with an R-2 of 0.258. The linear regression model indicates that a one-unit (pg/ml) increase in NT-proBNP corresponded to a 0.003-unit increase in Q(p)/Q(s) (P < 0.001). Patients with a Q(p)/Q(s) ratio >= 2 had significantly higher NT-proBNP levels than those with a ratio <2 (P < 0.001). Conclustion: This study, the largest cohort to date, reveals the correlation between non-invasive NT-proBNP level and invasive Q(p)/Q(s) measurement in children with ASD.