Study Design and Population
This is a retrospective study of all patients ≥ 18 years old who
underwent S-ICD implantation between 2010 and 2022 in a single
multihospital healthcare system (Northwestern Medicine, Chicago, IL).
Northwestern Medicine is comprised of four tertiary or quaternary care
hospitals within a single metropolitan area. All hospitals share a
single electronic medical record. Patients who were referred for S-ICD
extraction but underwent S-ICD implantation at another institution were
excluded from the analysis to ensure that the study population underwent
implantation according to a standardized protocol and were followed
internally for electrophysiologic care. Patient demographics, clinical
characteristics and procedural information were retrospectively
abstracted from the electronic medical record for all S-ICD implantation
procedures. The primary endpoint of this study was S-ICD removal or
extraction, collectively referred to as extraction. If a patient
underwent extraction, further clinical information was collected in a
retrospective manner from the time of extraction. This study was
approved by the Northwestern University Institutional Review Board.