Device-Related Complications and Inappropriate Therapies Among Subcutaneous vs. Transvenous Implantable Defibrillator Recipients: Insight Monaldi Rhythm Registry.

Introduction: In the context of randomized clinical trials, subcutaneous implantable cardiac defibrillators (S-ICDs) are non-inferior to transvenous ICDs (T-ICDs) concerning device-related complications or inappropriate shocks in patients with an indication for defibrillator therapy and not in need of pacing. We aimed at describing the clinical features of patients who underwent S-ICD implantation in our clinical practice, as well as the ICD-related complications and the inappropriate therapies among S-ICD vs. T-ICD recipients during a long-term follow-up.
Materials and Methods: All patients undergoing ICD, both S-ICD and TV-ICD, at Monaldi Hospital from January 1, 2015 to January 1, 2019 and followed up at our institution were included in the present analysis. The clinical variables associated with S-ICD implantation were evaluated by logistic regression analyses. We collected the ICD inappropriate therapies, ICD-related complications (including both pulse generator and lead-related complications), ICD-related infections, appropriate ICD therapies, and overall mortality. Kaplan-Meier (KM) analyses were performed to assess the risk of clinical outcome events between the two subgroups. A time-dependent Cox regression analysis was performed to adjust the results.
Results: Total 607 consecutive patients (mean age 53.8 ± 16.8, male 77.8%) with both TV-ICD ( n : 290, 47.8%) and S-ICD ( n : 317, 52.2%), implanted and followed at our center for a mean follow-up of 1614 ± 1018 days, were included in the study. At multivariate logistic regression analysis, an independent association between S-ICD implantation and ionic channel disease [ OR : 6.01 (2.26-15.87); p < 0.0001 ] and ischemic cardiomyopathy [ OR : 0.20 (0.12-0.35); p < 0.0001 ] was shown. The KM analysis did not show a significantly different risk of the inappropriate ICD therapies ( log rank p = 0.64 ) between the two subgroups; conversely, a significant increase in the risk of ICD-related complications ( log rank p = 0.02 ) and infections ( log rank p = 0.02 ) in TV-ICD group was shown. The adjusted risk for ICD-related infections [ OR : 0.07 (0.009-0.55), p = 0.01 ] and complications [0.31 (0.12-0.81) , p = 0.01 ] was significantly lower among patients with S-ICD.
Conclusions: The choice to implant S-ICD was mainly driven by younger age and the presence of ionic channel disease; conversely ischemic cardiomyopathy reduces the probability to use this technology. No significant differences in inappropriate ICD therapies were shown among S-ICD vs. TV-ICD group; moreover, S-ICD is characterized by a lower rate of infectious and non-infectious complications leading to surgical revision or extraction.
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
(Copyright © 2022 Russo, Rago, Ruggiero, Cavaliere, Bianchi, Ammendola, Papa, Tavoletta, De Vivo, Golino, D'Onofrio and Nigro.)