Clinical course of severe congenital aortic valve stenosis in children.

Background: Congenital valvular aortic stenosis (VAS) in children requires lifelong follow-up. An overview of age-specific treatment pathways from first diagnosis of severe VAS is lacking. Objectives: To assess patient journeys and outcomes after severe pediatric VAS diagnosis, by describing its clinical course and treatment trajectories based on a 37-year single-center experience. Methods: Baseline and time-related data of children diagnosed with severe congenital VAS between 1985 and 2022 were retrospectively collected. Time-related death (Kaplan-Meier estimator) and intervention occurrence (Aalen-Johansen estimator) were analyzed. Results: 245 children (73.1 % male, median age: 1.2 years (IQR:0.1-7.0)) were diagnosed with severe VAS (53 aged <30 days, 74 between 30d-1y, 84 between 1y-12y, 34 between 12y-18y). Median survival follow-up was 23.3 years (IQR:10.3-31.2) (99.0 % complete). Thirty-five-year incidence of death after diagnosis was 16.2 %(95 %CI:9.7-22.2 %). Of 245 patients, 211 patients (86.1 %) underwent an intervention and 34 (13.9 %) did not undergo an intervention. Of these 34 children, 7 children showed time-related Doppler gradient regression to mild-or-moderate VAS and 17 had stable severe VAS. These 24 children experienced a 6.0 % incidence of death at 30-years after diagnosis. The most common intervention over time (47.5 %) was balloon valvuloplasty, especially in neonates and infants, followed by aortic valve replacement (37.5 %), especially in older children. Conclusions: This study highlights the vast heterogeneity of treatment pathways and outcomes in children diagnosed with severe VAS at different ages. The observed stabilization of severe VAS or regression of the serial peak Doppler gradient to mild-or-moderate VAS without symptoms in 24 children highlights the need for better insight into determinants of disease course.