Single-coil and dual-coil defibrillator leads and association with clinical outcomes in a complete Danish nationwide ICD cohort

BACKGROUND: The best defibrillator lead in routine implantable cardioverter-defibrillator (ICD) patients is not settled. Traditionally, most physicians prefer dual coil leads but use of single coil leads is increasing.

OBJECTIVE: To compare clinical outcomes in patients with single and dual coil leads.

METHODS: All 4,769 Danish patients ≥18 years of age with first time ICD implants from 2007 to 2011 were included from the Danish Pacemaker and ICD Register. Defibrillator leads were 38.9% single coil and 61.1% dual coil. Primary endpoint was all-cause mortality. Secondary endpoints were lowest successful energy at implant defibrillation testing, first shock failure in spontaneous arrhythmias, structural lead failure, and lead extraction outcomes.

RESULTS: Single-coil leads were associated with lower all-cause mortality with an adjusted hazard ratio (aHR) of 0.85 (0.73-0.99), P = 0.04. This finding was robust in a supplementary propensity score matched analysis. However, dual coil leads were used in patients with slightly higher preimplant morbidity making residual confounding by indication the most likely explanation for the observed association between lead type and mortality. The lowest successful defibrillation energy was higher using single coil leads: 23.2 ± 4.3 J vs. 22.1 ± 3.9 J, P < 0.001. No significant differences were observed for other secondary endpoints showing high shock efficacies and low rates of lead failures and extraction complications.

CONCLUSIONS: Shock efficacy is very high for modern ICD systems. The choice between single and dual coil defibrillator leads is unlikely to have clinically significant impact on patient outcomes in routine ICD implants.