Abstract 17919: Defibrillation Thresholds in Single Versus Dual Coil ICD Lead Systems: Is There Any Difference?

Background: Single coil implantable cardioverter defibrillator (ICD) lead systems are less often utilized even though no significant difference in defibrillation threshold (DFT) has been demonstrated in comparison to dual coil ICDs. The superior vena cava (SVC) coil is associated with an active fibrotic reaction within the SVC, which can increase complication risk during extraction. We compared DFTs between single vs. dual coil ICD leads at initial implantation. Methods: Two hundred and fifty three consecutive patients who underwent new ICD implantation from 9/2008 to 9/2010 at our institution were retrospectively analyzed. Mean follow-up was 14.6±7.3 months. Results: Single coil was used more frequently vs. dual coil (172 vs. 81 pts). Age was lower in single coil group (63.0 vs. 72.1, p<0.001). There was no significant difference (single vs. dual coil, p>0.05) in sex, LV EF (28.9 vs. 26.6%), body mass index, ischemic cardiomyopathy, primary prophylaxis indication, procedural complications, lead extraction during follow up, and mortality. DFT testing was performed in 92% and 86% of patients in each group. There was no significant difference in DFTs (16.6±2.8 vs. 17.3±3.2J, p=0.13), DFT safety margin (18.9±3.1 vs. 18.9±3.8J, p=0.96) and successful shocks during follow up between the two groups. The single coil group with ischemic cardiomyopathy had lower DFT (16.1±2.5 vs. 17.9±3.4J, p=0.002), but single coil group with non-ischemic cardiomyopathy had higher DFT (17.7±3.1 vs. 15.9±2.3J, p= 0.03). Right-sided implants in single coil group had lower DFTs (16.4±4 vs. 18.3±2.4J, p=0.008). Two BMI groups (BMI <30 [25±2.5] vs. BMI ≥30 [35.5±4.2]) were analyzed. In BMI <30 group, DFT was lower in single coil group (16.6±3.0J vs. 18.3±3.5J, p=0.008). In BMI ≥30 group, there was no significant difference in DFT between two groups (16.7±2.6 vs. 16.1±2.5, p=0.30). Conclusion: Single coil ICD leads offer adequate safety margins in patients with ischemic and non-ischemic cardiomyopathy irrespective of sex, LV function, implant site, and BMI. They should offer a better safety profile during lead extractions.