Clinical experience of subcutaneous and transvenous implantable cardioverter defibrillators in children and teenagers

Background: Subcutaneous implantable cardioverter defibrillator (S-ICD) systems have no components in contact with the heart and may avoid complications such as lead fracture, venous obstruction, or endocarditis that occur with transvenous leads. Concerns have been raised regarding inappropriate shocks and pocket erosion with S-ICD systems. We have compared the performance of S-ICD and transvenous ICD systems in children and teenagers. Methods: We studied consecutive patients <20 years of age who received an ICD over a 4-year period in two Scottish centers. Baseline characteristics, complications, and ICD therapy were recorded. The primary outcome measure was survival. The secondary outcome measure was survival-free from inappropriate ICD therapy or system revision. Results: Nine S-ICD were implanted in nine patients. Eight transvenous ICD were implanted in six patients; two were redo procedures. Baseline characteristics were well matched. Median duration of follow-up was lower for S-ICD (20 months) than for transvenous ICD (36 months, P = 0.0262). Survival was 100% in both groups. Survival free of inappropriate therapy or system revision was 89% for S-ICD and 25% for transvenous ICD systems (log-rank test, P = 0.0237). No S-ICD were extracted, but three transvenous ICD were extracted due to infection (n = 1) and lead failure (n = 2). Conclusions: In real-world use in children and teenagers, S-ICD may offer similar survival benefit to transvenous ICD, with a lower incidence of complications requiring reoperation. In the absence of randomized trials, S-ICD should be compared prospectively with transvenous ICD in large multicenter registries with comparable periods of follow-up