LONG-TERM OUTCOMES OF PATIENTS WITH IMPLANTABLE CARDIOVERTER-DEFIBRILLATORS IMPLANTED IN CHILDHOOD: TRANSVENOUS VS. NONTRANSVENOUS SYSTEM

BACKGROUND: Implantable cardioverter-defibrillators (ICD) have been established as effective and safe therapy for prevention of sudden cardiac death in children. Controversy regarding ICD type (transvenous, T vs. non-transvenous, NT) led us to perform long-term analysis.
METHODS: A nationwide cohort of all patients (N=109, male 73, 67.0%) with ICDs implanted during childhood from 1993-2022 at median (IQR) age 14.3(10.7-16.6) years was retrospectively studied. Data were retrieved from the institutional databases and medical records and cross-mapped with the National Death Registry. Patients were followed-up for a median (IQR) of 62.2(27.1-127.3) months.
RESULTS: 94 patients received T and 15 NT systems (pericardial coil in 11, pleural coil in 1 and subcutaneous coil in 3 patients). Totally subcutaneous ICD systems were not included. Patients with NT ICDs were significantly younger (median age 4.6 vs. 15.3 years, p<0.001) and smaller (median weight 17.0 vs. 58.6 kg, p<0.001) at implant. There were 6 deaths (5.5%), all in patients with T systems, yielding a 5/10 years survival probability of 93.8/91.5%. Five years after ICD implantation freedom from appropriate therapy was 56.3/60.3% (p=0.886) and from inappropriate therapy 85.7/88.8% (p=0.751) in NT vs. T systems, respectively. A total of 37 surgical revisions for ICD related complications (except ERI enforced generator replacement) had to be performed 32 patients (29.4 %). None of the revisions in the NT group was associated with shock coil malfunction or strangulation of the heart in pericardial coil systems. Five years after implantation freedom from surgical revision in NT vs. T group was 72.7/73.7%, resp. (p=0.961).
CONCLUSIONS: NT ICDs are as effective and safe as T ICDs in treatment of malignant arrhythmias in children. Burden of surgical revisions is comparable.