Abstract 15653: Prevention of Sudden Cardiac Death with the Implantable Cardioverter-defibrillator in Children and Adolescents with Hypertrophic Cardiomyopathy: An International Multicenter Study
Introduction. Hypertrophic cardiomyopathy (HCM) is the most common cause of sudden death in the young. Availability of the implantable cardioverter-defibrillator (ICD) over the last decade has demonstrated its potential for sudden death (SD) prevention, but predominantly in adult HCM patients. Efficacy of ICDs in children/adolescents, generally less commonly considered for prophylactic implant, remains largely unresolved.
Hypothesis. We assessed efficacy of ICDs for aborting SD in young patients and utility of current risk stratification model for selection of patients leading to therapy.
Methods. We formulated an international, multicenter registry (n = 22 centers), of 224 HCM patients at high-risk for SD implanted with ICDs < 20 years old.
Results. Defibrillators activated appropriately to terminate VT/VF in 43 of 224 patients (19%) over 4.3 ± 3.3 years follow-up period. ICD intervention rates were 4.4%/year overall, 12.2%/year for secondary prevention after cardiac arrest, 3.2%/year for primary prevention (5-year probability; 17%). Time from implant to first appropriate intervention averaged 2.8 ± 2.6 years, up to 8.6 years. Likelihood of primary prevention appropriate interventions for VT/VF in patients with 1, 2, or ≥ 3 risk markers was 23, 21, and 27/100 person-years, including 12 of 26 patients (46%) implanted for only a single risk factor. Massive LV hypertrophy was the predominant risk factor predictive for interventions in 17 of 26 patients (65%). ICD-related complications, particularly inappropriate shocks with or without lead malfunction occurred in 91 patients (41%).
Conclusions. In a high-risk pediatric HCM cohort, ICD interventions frequently and effectively terminated life-threatening ventricular tachyarrhythmias, changing the disease course for many young patients. Extreme LV hypertrophy was the risk factor most reliable in predicting appropriate interventions. The large number of device-related complications and inappropriate shocks add significant complexity to ICD decisions in this age group.
- © 2012 by American Heart Association, Inc.