Assessment of Immediate, Short- and Long-Term Outcomes After Transcatheter Perimembranous Ventricular Septal Defect (PM VSD) Closure by KONAR-MF Occluder Device

Background: Perimembranous ventricular septal defect (PM VSD) is the most prevalent congenital heart defect, traditionally managed by surgical closure with associated morbidity. Objective: This study aimed to evaluate the immediate, short-, and one-year clinical outcomes of transcatheter PM VSD closure using the KONAR-MF occluder device in children, focusing on closure rates, valvular function, and rhythm disturbances. Methods: A prospective, single-arm cohort study was conducted at the National Institute of Cardiovascular Diseases (NICVD), Karachi, enrolling 42 patients aged <18 years with PM VSD suitable for device closure. Patients with right coronary cusp prolapse, pulmonary hypertension, or multiple congenital defects requiring surgery were excluded. Echocardiography, angiography, and electrocardiography were performed at baseline, post-procedure, and at 1, 3, 6, and 12 months. The study received ethical approval and adhered to the Declaration of Helsinki. Descriptive analysis was conducted using SPSS v26. Results: The mean age was 9.6 ± 5 years and weight 23.6 ± 12.4 kg. Immediate closure was achieved in 97.6%, sustained in 95.2% at 12 months. No cases of AV block, haemolysis, or significant arrhythmias were observed. Mild, non-progressive aortic regurgitation occurred in one patient (2.4%); tricuspid regurgitation improved over time. One unrelated death occurred at 12 months. Valvular function and ECG remained stable with no statistically significant deterioration (p > 0.05). Conclusion: Transcatheter PM VSD closure using the KONAR-MF occluder is a safe and effective alternative to surgery in selected pediatric patients, offering high closure rates and a low complication profile, supporting its clinical applicability in structural heart disease management.