Changes in right heart morphology and pulmonary arterial pressure following transcatheter Atrial Septal Defect (ASD) closure in adults

Introduction: Atrial septal defect (ASD) is one of the commonest congenital heart diseases. Pulmonary arterial hypertension (PAH) has been noted in 6% to 35% of patients with secundum ASD. PAH in unoperated patients with ASD has been associated with functional limitations, atrial tachyarrhythmias, heart failure, and reduced life expectancy. This study aims to evaluate right atrial and right ventricular dimensions, the severity of tricuspid regurgitation, and pulmonary arterial systolic pressure in adults before and after ASD device closure in a sample of the Nepalese population.Methods: This is a cross-sectional study on patients who underwent transcatheter ASD closure at a single centre in Nepal between January 2016 and December 2020, followed up from January 2023 to December 2023. Results: A total of 688 patients underwent ASD devise closure, of which 358 (52.03%) were available for follow-up. The cohort included patients aged 18–70 years (mean 35.8 ± 12.2 years), with a female predominance (72.9%). Device sizes ranged from 10–40 mm, with the Amplatzer septal occluder being most frequently used (95.2%). The mean follow-up duration was 58 (range 28–90) months. Prior to closure, all patients demonstrated right atrial and right ventricular dilatation, which persisted in only four (1.1%) patients post-procedure. Tricuspid regurgitation was predominantly mild to moderate before closure, with marked improvement thereafter. Mean tricuspid regurgitation pressure gradient (TRPG) decreased significantly from 47.03 ± 9.76 mmHg (range 16–92) to 13.6 ± 12.06 mmHg (range 0–90) post-closure. Pulmonary arterial hypertension (PAH), present as moderate to severe in most patients pre-procedure, was absent in the majority after closure, as assessed by echocardiography.Conclusion: ASD device closure effectively reduces right atrial and right ventricular size. TR and pulmonary artery systolic pressure in most of the cases. This study has established baseline values for the Nepalese population.