Comparison of Single-Coil and Dual-Coil Implantable Defibrillators: A Meta-Analysis

The purpose of this investigation was to conduct a meta-analysis of studies comparing defibrillation threshold (DFT) and outcomes with single-coil and dual-coil implantable cardioverter-defibrillator (ICD) systems.

Use of dual-coil rather than single-coil defibrillator leads may lower the DFT with a transvenous ICD system; however, dual-coil ICDs may have higher lead-related complications.

Sixteen studies, each with more than 10 human subjects, that compared single-coil and dual-coil ICD systems were included for the final analysis after a comprehensive publication search using predefined search terms and additional search from cross-references. A test of heterogeneity, pooling, and meta-analysis of the data from the studies were performed using R statistical software. A random effects model was used for meta-analysis.

Data pooled from 14 studies analyzed for difference in DFT showed an estimated difference in mean DFTs between single-coil and dual-coil ICDs of 0.81 J (95% confidence interval [CI]: 0.31 to 1.30 J), thus favoring dual-coil ICDs. However, pooled data from 5 studies revealed no difference in first-shock efficacy for dual-coil ICDs compared with single-coil ICDs (estimated overall odds ratio: 0.94; 95% CI: 0.49 to 1.78; p = 0.85). The all-cause mortality rate analyzed from 4 studies was lower in patients with single-coil ICDs (estimated hazard ratio: 0.91; 95% CI: 0.83 to 0.99).

There was a marginal difference in the defibrillation threshold of transvenous ICDs between single-coil and dual-coil lead systems. However, first-shock efficacy was no different between the 2 groups, and patients with single-coil ICDs had favorable all-cause mortality rates on the basis of data from nonrandomized studies. Potential risks and benefits of single-coil and dual-coil ICD leads should be carefully weighed.