Nationwide pediatric experience with endocardial, subcutaneous, and hybrid extravascular ICD systems
Z Nagy, L Rarosi, O Csenteri, A Szabo, G Fesus, Z Som, L KornyeiAbstract
Background
Implantable cardioverter-defibrillator (ICD) therapy plays a key role in the prevention of sudden cardiac death. In children, smaller body size and anatomical constraints often necessitate hybrid procedures that require surgical exposure of the chest or pericardium. Beyond technical feasibility, the underlying diagnosis also influences the choice of ICD system.
Purpose
This study aimed to compare demographic and clinical characteristics, outcomes and complications among endocardial, subcutaneous, and hybrid ICD systems in the pediatric population.
Methods
We performed a retrospective, single-center, population-based study including all pediatric ICD implantations between 2010 and 2025 (n=86; median age: 13 years [IQR 12–16]; 39,5% female; median weight: 56 kg [IQR 42–72]). Patients (pts) were classified into three groups: Type 1 (endocardial, n=54), Type 2 (subcutaneous, n=20), and Type 3 (hybrid, n=12). Anthropometric and clinical characteristics, underlying diagnoses, and clinical outcomes were compared across groups. Within the hybrid group, subgroups were formed based on the surgical technique. Logistic regression analyses were performed to identify predictors of inappropriate shocks and device-related complications.
Results
Significant differences were observed in age, body weight, and height across the groups (all p<0.001). The distribution of underlying etiologies and the rate of appropriate shocks did not differ significantly (p=0.069 and p>0.57, respectively). Reoperations were significantly more frequent in the Type 1 group (44.4%) compared with Type 2 (10.0%) and Type 3 (16.7%) (p=0.008). Within the hybrid group, the ventricular pace–sense lead was epicardial in 11/12 pts. The shock coil location varied, being subcutaneous in 3, pericardial in 8, and pleural in 1 pt. Generator was placed in the left hypochondrium (n=2), right hypochondrium (n =7), left lateral subcutaneous region (n=2), and right pectoral region (n=1). Logistic regression identified no significant predictors of inappropriate shocks or device-related complications, independent of body weight. For inappropriate shocks, endocardial ICDs showed an OR of 0.98 (p=0.97) and hybrid ICDs 0.98 (p=0.98), both relative to subcutaneous systems. For complications, endocardial ICDs demonstrated an OR of 0.075 (p=0.085), while hybrid ICDs showed an OR of 1.30 (p =0.73), compared with subcutaneous ICDs.
Conclusion
While anthropometric differences reflected patient selection, device type was not significantly associated with inappropriate shocks or complication risk. Hybrid ICD systems demonstrated acceptable procedural characteristics and complication rates comparable to endocardial and subcutaneous systems, making them a feasible alternative when conventional approaches are limited.