The SIDECAR 2.0 (S-ICD registry in European paediatric and young adult patients with congenital heart defects 2.0): an analysis of European S-ICD clinical practice and its evolution in paediatric patients

Subcutaneous implantable cardioverter-defibrillators (S-ICDs) are effective in patients who require protection from sudden cardiac death while avoiding the long-term risks associated with transvenous leads. However, data on their real-world performance in paediatric and young patients remain limited. This study aims to evaluate the safety and efficacy of S-ICDs in a large, multicentre cohort of paediatric and young patients across Europe, with a focus on contemporary implantation practices and clinical outcomes.

This is an international, multicentre, observational, retrospective registry on S-ICD outcome in paediatric and young adult patients with congenital heart defects (CHD), cardiomyopathies, channelopathies, and idiopathic ventricular fibrillation (IVF). Data were collected on implantation techniques, acute and long-term outcomes, including defibrillation efficacy, inappropriate (IAS) and appropriate shocks, and complications. Follow-up data were analysed to assess device performance and safety. A total of 223 patients (mean age: 15 ± 3 years; 59% male, 53% cardiomyopathies, 18% channelopathies, 15% IVF, 14% CHD) were included. Most patients underwent implantation using an intermuscular (65%) and two-incision technique (88%). Acute defibrillation success was 100%, and no intraoperative complications occurred. The median follow-up was 28 (IQR: 12–55) months. Appropriate shocks were delivered in 41 (18%) patients (26% rate at 5 years). The first shock was effective in 92% of discrete episodes. The IAS and the complication rates were 20% and 5% at 5 years. Older age, intermuscular pocket, and two-incision technique were associated with fewer complications.

This multicentre S-ICD European registry in paediatric and young patients demonstrated favourable outcomes, low IAS, and complication rates.