title: Primary prevention implantable cardioverter defibrillator recipients: the need for defibrillator back-up after an event-free first battery service-life.
abstract: BACKGROUND
  In primary prevention implantable cardioverter defibrillator (ICD) patients, the relatively low incidence of ventricular arrhythmias (VA) combined with the limited battery service-life potentially results in a large group of patients who have had no benefit of the ICD during first service-life. Data on the occurrence of VA after device replacement remain scarce. The purpose of this study was to give clinicians better insight in the dilemma whether or not to replace an ICD after an event-free first battery service-life.
  
  
  RESULTS
  All patients treated with an ICD for primary prevention who had a replacement because of battery depletion and who did not receive appropriate therapy before device replacement were included in this analysis. Of 154 primary prevention ICD patients needing replacement because of battery depletion, 114 (74%) patients (mean age 61 ± 11 years, 80% male) had not received appropriate ICD therapy for VA. Follow-up was 71 ± 24 months after the initial implantation and 25 ± 21 months after device replacement. Following replacement, 3-year cumulative incidence of appropriate therapy in response to ventricular tachycardia or ventricular fibrillation was 14% (95% CI 5-22%).
  
  
  CONCLUSIONS
  The majority of primary prevention ICD patients do not experience VA during first battery service-life. However, a substantial part of these patients does experience appropriate ICD therapy after replacement.
authors.affiliation: Department of Cardiology, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: Guido H
authors.initials: GH
authors.lastname: Van Welsenes
authors.forename: Johannes B
authors.initials: JB
authors.lastname: Van Rees
authors.forename: Joep
authors.initials: J
authors.lastname: Thijssen
authors.forename: Serge A
authors.initials: SA
authors.lastname: Trines
authors.forename: Lieselot
authors.initials: L
authors.lastname: Van Erven
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Schalij
authors.forename: C J W
authors.initials: CJ
authors.lastname: Borleffs
mesh_terms: D000368:Aged; D017147:Defibrillators, Implantable; D011211:Electric Power Supplies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011322:Primary Prevention; D017180:Tachycardia, Ventricular / Q000453:epidemiology / Q000517:prevention & control; D014693:Ventricular Fibrillation / Q000453:epidemiology / Q000517:prevention & control