Percutaneous closure of ostium secundum atrial septal defect (ASD) has become the standard of care for this condition. However, the management of very large ASDs remains less extensively studied, particularly regarding long-term outcomes. We aimed to assess peri-procedural and long-term outcomes following implantation of very large closure devices compared with smaller devices.

We conducted a prospective, single-center cohort study including consecutive patients aged ≥ 15 years who underwent percutaneous ostium secundum ASD closure at Marie Lannelongue Hospital between 1998 and 2021. Peri-procedural and long-term outcomes were systematically collected. Patients were categorized according to implanted device size: ≥ 34 mm (very large device group) versus < 34 mm. Comparative analyses were performed between groups.

A total of 1497 patients were included, of whom 257 (17.1%) received a device ≥ 34 mm. Baseline clinical characteristics were similar between groups, except for a prior history of stroke/TIA, which was more frequent in the < 34 mm group (OR 0.38 [0.18–0.80]; P = 0.01). There were no significant differences in baseline electrocardiographic characteristics, including history of atrial arrhythmia (OR 1.15 [0.77–1.70]; P = 0.50). During the peri-procedural period, patients receiving devices ≥ 34 mm had a significantly higher incidence of intra-procedural atrial arrhythmias (OR 5.90 [1.79–19.50]; P = 0.003) and device embolization (OR 3.68 [1.25–10.70]; P = 0.021). Over a mean follow-up of 10.0 years, no statistically significant differences were observed between groups in all-cause mortality (OR 0.97 [0.52–1.85]; P = 1.00), cardiac reintervention (OR 1.34 [0.37–4.79]; P = 0.64), stroke (OR 1.34 [0.50–3.63]; P = 0.56), heart failure (OR 1.53 [0.71–3.29]; P = 0.28), or atrial arrhythmia (OR 1.24 [0.78–1.98]; P = 0.36).

Percutaneous closure of ostium secundum ASD using very large devices (≥ 34 mm) is associated with a higher risk of peri-procedural atrial arrhythmia and device embolization. However, long-term clinical outcomes are comparable to those observed with smaller devices, supporting the overall safety and efficacy of this approach in selected patients.