Safety and efficacy of subcutaneous implantable cardioverter-defibrillator in dialysis patients: insights from a systematic review

Introduction The subcutaneous ICD (S-ICD) should be considered according to current guidelines for dialysis patients for its extravascular system, by preserving and reducing vascular access complications and may lower infection risk. However, evidence regarding long-term safety and efficacy in this population remains limited. The number of dialysis patients receiving S-ICDs has now surpassed those implanted with transvenous ICDs (TV-ICDs), highlighting the need to evaluate real-world outcomes. Methods A systematic review was conducted comparing (1) S-ICD and TV-ICD outcomes in dialysis patients, and (2) S-ICD outcomes according to dialysis status (dialysis vs. non-dialysis). Searches were performed in PubMed, ClinicalTrials.gov, and Embase using the terms "defibrillation," "hemodialysis," "dialysis," and "ICD." The primary endpoints were overall complications, infections and efficacy (appropriate and inappropriate shocks). Results For comparison of S-ICD and TV-ICD outcomes in dialysis patients, 3 studies were included (n = 4,751; 2,094 S-ICD and 2,647 TV-ICD). Mean age of 62 years, 69.2% male, mean LVEF 27.4%, ischemic etiology in 64%, and primary prevention in 86.9%. The mean follow-up was 58 months. Among dialysis patients, no significant differences were found between S-ICD and TV-ICD regarding total complications (p = 0.78) or infection rates (p = 0.24) [figure 1A and 1B]. For comparison of dialysed status vs non-dialysed outcomes in S-ICD recipients, another three additional studies were analyzed (n = 1,802; 265 dialyzed, 1,537 non-dialyzed). Mean age of 55 years, mean LVEF 29.1%, ischemic etiology in 43.8%, and 74.7% had primary prevention indications, with a mean follow-up of 10.5 months. Within the S-ICD cohort, dialysis patients showed a trend toward higher overall complications, without significance (p = 0.65) as the infection risk (p = 0.57) compared with non-dialysis recipients [Figure 2A and 2B]. Regarding safety, the rate of appropriate shocks was higher in dialysis patients (p < 0.00001), while inappropriate shocks were comparable (p = 0.94) [Figure 2C and 2D]. Conclusion Despite theoretical advantages and current guideline support, in this systematic analysis the S-ICD did not demonstrate lower complication or infection rates compared with TV-ICDs in dialysis patients, during medium term follow-up. Likewise, among S-ICD recipients, dialysis status did not significantly impact safety outcomes. Device efficacy was preserved across groups. These findings suggest that while S-ICDs remain a reasonable option in dialysis patients, their superiority over transvenous systems in reducing complications has yet to be confirmed.