Comparison of subcutaneous and transvenous implantable cardioverter-defibrillators: Insights from a single-center cohort in Taiwan

BACKGROUND: Transvenous implantable cardioverter-defibrillators (TV-ICDs) are associated with complications from intravenous leads. Subcutaneous ICDs (S-ICDs) were developed as a safer, effective alternative. This study evaluated the efficacy and safety of S-ICDs in an Asian population. METHODS: In this single-center retrospective study, we reviewed adult patients with indications for single-chamber ICDs who did not require pacing or have pace-terminable ventricular tachycardia. Propensity score matching in a 1:2 ratio was applied to compare patients with S-ICDs and TV-ICDs. The primary outcome was a composite of device-related complications and inappropriate shocks. Secondary outcomes included all-cause mortality, appropriate shock therapy, and heart failure hospitalization. RESULTS: From 2020 to 2024, 110 patients (13 with S-ICDs and 97 with TV-ICDs) met inclusion criteria. After propensity score matching, 13 S-ICD and 26 TV-ICD patients were analyzed (82.1 % male; mean age, 43.7 ± 14.2 years). The primary outcome occurred in 15.4 % of the S-ICD group and 19.2 % of the TV-ICD group (hazard ratio [HR], 1.18; 95 % confidence interval [CI], 0.22-6.19). Device-related complications were observed in 1 S-ICD and 4 TV-ICD patients (HR, 0.79; 95 % CI, 0.09-7.24), while inappropriate shocks occurred in 1 patient in each group (HR, 2.45; 95 % CI, 0.15-39.72). Appropriate shocks were delivered in 4 S-ICD and 7 TV-ICD patients (HR, 1.56; 95 % CI, 0.45-5.47). CONCLUSION: Among patients eligible for ICDs without pacing indications, S-ICDs demonstrated comparable safety and efficacy to TV-ICDs, with no significant differences in device-related complications or inappropriate shocks.