Benefits and risks of implantable cardioverter-defibrillators in children and young adults with congenital heart disease, primary electrical disease or paediatric cardiomyopathy†.

Objectives: This study aimed to investigate the benefits and potential risks of implantable cardioverter-defibrillators in paediatric and congenital heart disease (CHD) patients in the current era.

Methods: All patients with CHD, paediatric cardiomyopathy or primary electrical disease, who underwent implantation of a defibrillator from 2001 to 2023, were examined. The occurrence of appropriate therapy, unplanned surgeries due to device complications, inappropriate shocks and associated risk factors were analysed.

Results: A total of 214 patients were included, with 61% having CHD, 17% having paediatric cardiomyopathy and 22% having primary electrical disease. The most common diagnoses were transposition of the great arteries and tetralogy of Fallot (each 12%). The median age at implantation was 23 years (interquartile ranges 15-38), and the median follow-up was 5.7 years (95% confidence interval 4.9-7.3). A total of 196 patients met the criteria for outcome analysis, where appropriate therapy was observed in 41% (n = 80), occurring more often in patients with indications for secondary prevention than primary prevention (56% vs 26% at 5 years, P = 0.003). The cumulative incidence of inappropriate shocks was 13% (n = 26), with patients with CHD being more frequently affected. Unplanned surgeries were required in 36% (n = 71), predominantly due to lead-related issues in those with abdominal generator placement.

Conclusions: The high rate of appropriate therapies underscores the critical importance of risk assessment in ICD selection, particularly to mitigate lead failures and unnecessary shocks. However, defibrillator therapy has a relevant rate of unplanned surgeries, with abdominal generators and epicardial/extracardiac leads being risk factors.