title: Single-coil and dual-coil defibrillator leads and association with clinical outcomes in a complete Danish nationwide ICD cohort.
abstract: BACKGROUND
  The best choice of defibrillator lead in patients with routine implantable cardioverter-defibrillator (ICD) is not settled. Traditionally, most physicians prefer dual-coil leads but the use of single-coil leads is increasing.
  
  
  OBJECTIVE
  The purpose of this study was to compare clinical outcomes in patients with single- and dual-coil leads.
  
  
  METHODS
  All 4769 Danish patients 18 years or older 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 leads and 61.1% dual-coil leads. The primary end point was all-cause mortality. Secondary end points 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 of 0.85 (95% confidence interval 0.73-0.99; P = .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 < .001). No significant differences were observed for other secondary end points showing high shock efficacies and low rates of lead failures and extraction complications.
  
  
  CONCLUSIONS
  Shock efficacy is high for modern ICD systems. The choice between single-coil and dual-coil defibrillator leads is unlikely to have a clinically significant impact on patient outcomes in routine ICD implants.
authors.affiliation: Department of Cardiology, Center for Cardiovascular Research, Aalborg University Hospital, Aalborg, Denmark. Electronic address: jaml@rn.dk.
authors.forename: Jacob M
authors.initials: JM
authors.lastname: Larsen
authors.affiliation: Department of Cardiology, Center for Cardiovascular Research, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Søren P
authors.initials: SP
authors.lastname: Hjortshøj
authors.affiliation: Department of Cardiology, Aarhus University Hospital Skejby, Aarhus, Denmark.
authors.forename: Jens C
authors.initials: JC
authors.lastname: Nielsen
authors.affiliation: Department of Cardiology, Odense University Hospital, Odense, Denmark.
authors.forename: Jens B
authors.initials: JB
authors.lastname: Johansen
authors.affiliation: Department of Cardiology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
authors.forename: Helen H
authors.initials: HH
authors.lastname: Petersen
authors.affiliation: Department of Cardiology, Copenhagen University Hospital Gentofte, Copenhagen, Denmark.
authors.forename: Jens
authors.initials: J
authors.lastname: Haarbo
authors.affiliation: Department of Cardiology, Center for Cardiovascular Research, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Martin B
authors.initials: MB
authors.lastname: Johansen
authors.affiliation: Department of Cardiology, Center for Cardiovascular Research, Aalborg University Hospital, Aalborg, Denmark.
authors.forename: Anna Margrethe
authors.initials: AM
authors.lastname: Thøgersen
mesh_terms: D000368:Aged; D001145:Arrhythmias, Cardiac / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D002423:Cause of Death / Q000639:trends; D017147:Defibrillators, Implantable; D003718:Denmark / Q000453:epidemiology; D004554:Electric Countershock / Q000295:instrumentation*; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012042:Registries; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D013997:Time Factors
keywords: Coil; Defibrillation; ICD; Implantable cardioverter-defibrillator; Lead extraction; Lead failure; Leads; Mortality