Efficacy and safety of the subcutaneous implantable cardioverter defibrillator in patients with and without obesity: An international, bicentric retrospective registry

AIM: This study evaluated the efficacy and safety of the subcutaneous implantable cardioverter defibrillator (S-ICD) in patients with obesity. METHODS: ). Defibrillation testing (DFT) failure, shock impedance, rates of appropriate and inappropriate shock, long-term complications, survival, and device-related or cardiac rehospitalizations were compared. RESULTS: Of the 120 patients included, most baseline characteristics were similar between patients with (n = 30) and without obesity (n = 90), except for a higher prevalence of diabetes in the group with obesity. The first shock during DFT was similarly effective (99 vs. 100%), although, shock impedance was significantly higher in patients with obesity (59 vs. 74 Ω; p = 0.011). There was no difference between the groups regarding the incidence of appropriate (hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.21-2.34, p = 0.584), and inappropriate shocks (HR 0.92, 95% CI 0.23-3.48, p = 0.902). Non-infectious complications occurred numerically more often in obese patients (16.7% vs. 4.9%, p = 0.058), while device-associated infections were more frequent among non-obese patients (7.4% vs. 0%, p = 0.188). The risk of all-cause mortality (HR 0.32; 95% CI 0.11-0.97; p = 0.141), device-related (HR 0.52; 95% CI 0.14-1.90; p = 0.395) or cardiac rehospitalization (HR 1.06; 95% CI 0.48-2.32; p = 0.890) were similar between the groups. CONCLUSION: Despite higher shock impedance during DFT at S-ICD implantation, shock efficacy remained stable during implantation and follow-up in both groups. Fewer infectious but more system-specific complications may manifest in patients with obesity compared to non-obese patients.