Efficacy and safety of the subcutaneous implantable cardioverter-defibrillator in patients with and without obesity: A meta-analysis

Abstract

Background

The subcutaneous implantable cardioverter-defibrillator (S-ICD) has emerged as an alternative to transvenous systems for prevention of sudden cardiac death. However, concerns have been raised regarding its efficacy and safety in obese individuals.

Objective

The purpose of this study was to perform a meta-analysis to evaluate the efficacy and safety of the S-ICD in patients with obesity by assessing the relationship between body mass index (BMI) and clinical outcomes.

Methods

A comprehensive search of multiple databases was conducted for English-language peer-reviewed studies reporting clinical outcomes in S-ICD recipients with (BMI ≥30 kg/m²) and without obesity (BMI <30 kg/m²). Data on preimplantation screening failure, defibrillation testing, complications, appropriate and inappropriate shocks, and survival were analyzed using standard, random-effects, meta-analytical techniques.

Results

Twenty-nine studies involving 20,486 patients were included. There was no statistically significant difference in mean BMI values of patients with failed or successful preimplantation screening (mean difference –0.60 kg/m²; 95% confidence interval [CI] –2.06 to 0.86). Obesity was associated with higher rates of failed defibrillation testing at ≤65 J (odds ratio [OR] 2.16; 95% CI 1.39–3.35), and malpositioning/suboptimal positioning occurred more frequently in obese compared to nonobese patients (OR 3.37; 95% CI 1.76–6.44). Increased BMI as a continuous variable (per increase in 1 kg/m² BMI) was associated with elevated defibrillation thresholds (OR 1.05; 95% CI 1.03–1.08); higher risk of complications (hazard ratio [HR] 1.04; 95% CI 1.02–1.05); a trend toward an increased number of appropriate shocks (HR 1.02; 95% CI 1.00–1.04); and no significant increase in the risk of inappropriate shocks (HR 1.01; 95% CI 0.99–1.03).

Conclusion

This meta-analysis underscores the importance of considering obesity in S-ICD implantation decisions. Although S-ICD remains effective in obese patients, attention to potential technical challenges and higher complication rates is warranted.