Primary prevention of sudden cardiac death in children with hypertrophic cardiomyopathy: experience with implantable cardioverter-defibrillators

Hypertrophic cardiomyopathy is the most common cause of sudden cardiac death in both adults and children. A crucial issue is identifying children with hypertrophic cardiomyopathy (HCM) who are at high risk of sudden cardiac death and require an implantable cardioverter-defibrillator for primary prevention of sudden cardiac death. Objective . To evaluate the effectiveness of implantable cardioverter defibrillators (ICDs) as the primary prevention of sudden cardiac death in children with hypertrophic cardiomyopathy. Material and methods . Data were collected from a single pediatric center (2009–2024), including 200 children and adolescents with hypertrophic cardiomyopathy, 77 patients underwent implantation of a cardioverter defibrillator for the primary prevention of sudden cardiac death. Results . Appropriate shocks on ventricular tachycardia and ventricular fibrillation occurred in 8 out of 77 patients (10.4%) within 1.25 years (IQR 0.6–3). The median time from implantation to the first discharge was 2 years (IQR 1.2–2.3). The annual frequency of appropriate ICD shocks was 3.5% per year. A direct correlation of the responses on the number of risk factors for sudden cardiac death was obtained. In patients with two or more risk factors, the likelihood of motivated response was 12 times higher than in those with fewer risk factors (OR/OR 12.12; CI 95% 1.47–99.65). The values of 5-year risk of sudden cardiac death >16% (HCM Risk-Kids) and >11.9% (HCM Risk-SCD) had the best prognostic value (AUC 0.738; p<0.05 and AUC 0.935; p<0.001, respectively). No significant correlation was found between an estimated 5-year SCD risk of 6% (HCM Risk-Kids and HCM Risk-SCD) and the frequency of ICD activations. Inappropriate ICD activations were recorded in 6 patients (7.8%), while complications were observed in 3 (3.9%). Conclusion . The high prognostic significance of the factorial approach to the stratification of the risk of SCD in children with HCM has been established. It is necessary to further improve the cut-off points for determining indications for implantation of cardioverter defibrillators in children based on 5-year models of sudden cardiac death in pediatric patients.