Characteristics and early clinical outcomes of patients undergoing totally subcutaneous vs. transvenous single chamber implantable cardioverter defibrillator placement

Aims: In 2012, the first totally Subcutaneous Implantable Cardioverter-Defibrillator (S-ICD) was approved by the Food and Drug Administration (FDA) in the United States. A possible benefit of this device is that it does not involve placing leads 'in' or 'on' the heart, potentially reducing complications. Methods amd results: Ninety-one S-ICD and 182 single chamber TV-ICD implants were performed between 10/22/2012 and 9/22/2015. During this period of time, 91 patients with S-ICD were matched to TV-ICD patients using single centre NCDR ICD Registry Data based on dialysis status, gender, and age. Intra- and post-operative complications and deaths were examined within the first 180 days following implantation. Patients with S-ICDs had higher creatinine (2.3 ± 2.5 vs. 1.1 ± 0.7, P < 0.001) and were more likely to be on chronic dialysis (20.9% vs. 5.5%, P < 0.001) than TV-ICD patients. Patients in the S-ICD group were more likely to have had prior device infections (14.3% vs. 3.3%, P = 0.021) as well as prior TIA/CVA (14.3% vs. 4.4%, P = 0.049) compared to patients in the TV-ICD group. Seven patients experienced 7 complications or death in TV-ICD group and 5 patients experienced 7 complications or death in SQ-ICD group, P = 0.774. Conclusion: In this retrospective matched single centre cohort study, there was no significant difference in implantation complications or death in patients receiving single chamber TV-ICDs compared to S-ICDs within 6 months following implantation. This occurred despite more severe preexisting illness in the S-ICD group. Further investigation is needed to determine outcomes after longer-term follow-up.