Abstract / Summary
Atrial septal defect (ASD) is one of the most common congenital heart anomalies and is associated with chronic right-sided volume overload, chamber dilatation, impaired ventricular function, and pulmonary hypertension. Transcatheter closure using occluder devices is considered the treatment of choice in most cases. However, evidence regarding the precise characterization of structural and functional cardiac changes following intervention, particularly in relation to different defect sizes, remains limited. This study aimed to comprehensively assess cardiac structural and functional remodeling in children before and six months after transcatheter ASD closure and to evaluate the impact of defect size on these changes. In this prospective observational study, 53 patients younger than 18 years with secundum atrial septal defects (ASDs) and significant left-to-right shunting (Qp/Qs ≥ 1.5) underwent transcatheter closure. Transthoracic echocardiography was performed before the procedure and at 6-month follow-up to assess right atrial (RA) and right ventricular (RV) function, tricuspid annular plane systolic excursion (TAPSE), myocardial performance index (MPI), inferior vena cava (IVC) dimensions, and pulmonary artery pressure (PAP). A subgroup analysis was performed to compare patients with ASD diameters < 10 mm and ≥ 10 mm. Following transcatheter ASD closure, significant reverse cardiac remodeling was observed. Right atrial decreased markedly (p < 0.001). Right ventricular systolic function improved significantly, as demonstrated by increases in tricuspid annular plane systolic excursion (TAPSE) (p < 0.001). Global ventricular performance, assessed by the myocardial performance index (MPI), also improved significantly (p < 0.001). Diastolic function showed favorable changes, with decreased E/A ratio and decreased E/e’ ratio ( p < 0.001). When stratified by ASD size, patients with defects ≥ 10 mm ( n = 32) showed significant improvement in right ventricular structural and functional parameters, including TAPSE, E/e′, MPI, and fractional area change ( p < 0.001 for all), whereas patients with defects < 10 mm ( n = 21) showed significant structural reverse remodeling but no significant change in right ventricular functional indices ( p > 0.05 for all), and residual chamber enlargement was more common among patients with larger defects. Baseline defect size was significantly associated with the magnitude of structural and functional cardiac improvement. Transcatheter ASD closure was associated with significant improvement in right heart structural parameters at 6 months in all patients, and in right ventricular functional parameters specifically among patients with larger defects; findings should be interpreted within the single follow-up time point of this study. Not applicable.