Perspective:

The advantages of the totally subcutaneous ICD include elimination of complications related to venous access, no need for fluoroscopy during implantation, no physical stress on leads associated with cardiac motion, less morbidity associated with device extraction, and a potential reduction in endovascular infection risk to patients with dialysis access or endovascular prostheses. The present study offers some assurance that S-ICD is safe and effective at least up to 3 years. Introduction of dual zone programing during the study period resulted in welcome reduction in inappropriate shocks to the levels more in line with transvenous ICDs. The present study stands out among other ICD trials in terms of its very low mortality rate of 1.6% annually. This is much less than in most primary prevention trials. It is therefore even more surprising given that almost one third of patients in the current study received S-ICDs for secondary prevention. I suppose this is reflecting the fact that patients in the current study are younger, more active, and perhaps healthier (by definition none of them required pacing). Of note, no study to date has directly compared the transvenous and totally subcutaneous ICD.