Subcutaneous versus transvenous implantable defibrillator: An updated meta-analysis

Background: Implantable cardioverter-defibrillator (ICD) placement is a well-established therapy for prevention of sudden cardiac death. The subcutaneous implantable cardioverter-defibrillator (S-ICD) was specifically designed to overcome some of the complications related to the transvenous implantable cardioverter-defibrillator (TV-ICD), such as lead complications and systemic infections. Evidence on the comparison of S-ICD vs TV-ICD are limited.

Objective: The purpose of this study was to conduct an updated meta-analysis comparing S-ICD vs TV-ICD.

Methods: Electronic databases were searched for studies directly comparing clinical outcomes and complications between S-ICD and TV-ICD. The primary outcome was the composite of clinically relevant complications (lead, pocket, major procedural complications; device-related infections) and inappropriate shocks. Secondary outcomes included death and the individual components of the primary outcome.

Results: Thirteen studies comprising 9073 patients were included in the analysis. Mean left ventricular ejection fraction was 40% ± 10%; 30% of patients were female; and 73% had an ICD implanted for primary prevention. There was no statistically significant difference in the risk of the primary outcome between S-ICD and TV-ICD (odds ratio [OR] 0.80; 95% confidence interval [CI] 0.53-1.19). Patients with S-ICD had lower risk of lead complications (OR 0.14; 95% CI 0.06-0.29; P <.00001) and major procedural complications (OR 0.18; 95% CI 0.06-0.57; P = .003) but higher risk of pocket complications (OR 2.18; 95% CI 1.30-3.66; P = .003) compared to those with TV-ICD. No significant differences were found for the other outcomes.

Conclusion: In patients with an indication for ICD without the need for pacing, TV-ICD and S-ICD are overall comparable in terms of the composite of clinically relevant device-related complications and inappropriate shock.