Subcutaneous implantable cardioverter defibrillator in children and adolescents: results from the S-ICD 'Monaldi care' registry

Background: Implantable cardioverter defibrillators (ICD) are widely accepted therapy in children and adolescents who are survivors of cardiac arrest or for high-risk patients with inheritable channelopathies, cardiomyopathies, or congenital heart disease. Initial experience with subcutaneous ICD (S-ICD) systems has shown a high efficacy in adults. However, the use of S-ICD in children and adolescents implies some specific considerations, as the safety for these patients is unknown and recommendations among physicians may vary widely. Methods: We reviewed the data and studied the indications for S-ICD in children and adolescents and discuss the preliminary clinical experience. Results: From a cohort of 297 patients enrolled in the S-ICD “Monaldi care” registry that encompass all the patients implanted in the Monaldi Hospital of Naples, we considered 21 consecutive children and adolescents (mean age 13.9 years, range 8-18 years, mean body weight 59.3 kg, range 38-100 kg) who underwent S-ICD implant from April 2014 to June 2020. Mean follow-up was 41.9±21.9 months. Only one patient presented, 6 weeks after implantation, skin erosion at the inferior parasternal incision that resolved after antibiotic therapy, without the necessity of any system revision. Two patients experienced appropriate shocks and four inappropriate shocks, due to T wave oversensing or atrial arrhythmia. Only one patient, with arrhythmogenic right ventricular dysplasia, required a system revision after 36 months of the first implantation and then a reintervention with a replacement of the S-ICD by a conventional ICD system. Conclusions: Our experience suggests that the S-ICD device can be used in some children over the age of 8 as well as adults, with a similar rate of unwanted side effects, and early evidence of apparent efficacy.