title: Use of implantable cardioverter defibrillators after out-of-hospital cardiac arrest: a prospective follow-up study.
abstract: BACKGROUND
  Survivors of out-of-hospital cardiac arrest are at high risk of recurrent arrests, many of which could be prevented with implantable cardioverter defibrillators (ICDs). We sought to determine the ICD insertion rate among survivors of out-of-hospital cardiac arrest and to determine factors associated with ICD implantation.
  
  
  METHODS
  The Ontario Prehospital Advanced Life Support (OPALS) study is a prospective, multiphase, before-after study assessing the effectiveness of prehospital interventions for people experiencing cardiac arrest, trauma or respiratory arrest in 19 Ontario communities. We linked OPALS data describing survivors of cardiac arrest with data from all defibrillator implantation centres in Ontario.
  
  
  RESULTS
  From January 1997 to April 2002, 454 patients in the OPALS study survived to hospital discharge after experiencing an out-of-hospital cardiac arrest. The mean age was 65 (standard deviation 14) years, 122 (26.9%) were women, 398 (87.7%) had a witnessed arrest, 372 (81.9%) had an initial rhythm of ventricular tachycardia or ventricular fibrillation (VT/VF), and 76 (16.7%) had asystole or another arrhythmia. The median cerebral performance category at discharge (range 1-5, 1 = normal) was 1. Only 58 (12.8%) of the 454 patients received an ICD. Patients with an initial rhythm of VT/VF were more likely than those with an initial rhythm of asystole or another rhythm to undergo device insertion (adjusted odds ratio [OR] 9.63, 95% confidence interval [CI] 1.31-71.50). Similarly, patients with a normal cerebral performance score were more likely than those with abnormal scores to undergo ICD insertion (adjusted OR 12.52, 95% CI 1.74-92.12).
  
  
  CONCLUSIONS
  A minority of patients who survived cardiac arrest underwent ICD insertion. It is unclear whether this low usage rate reflects referral bias, selection bias by electrophysiologists, supply constraint or patient preference.
authors.affiliation: Ottawa Health Research Institute.
authors.forename: Ratika
authors.initials: R
authors.lastname: Parkash
authors.forename: Anthony
authors.initials: A
authors.lastname: Tang
authors.forename: George
authors.initials: G
authors.lastname: Wells
authors.forename: Josée
authors.initials: J
authors.lastname: Blackburn
authors.forename: Ian
authors.initials: I
authors.lastname: Stiell
authors.forename: Christopher
authors.initials: C
authors.lastname: Simpson
authors.forename: Paul
authors.initials: P
authors.lastname: Dorian
authors.forename: Raymond
authors.initials: R
authors.lastname: Yee
authors.forename: Doug
authors.initials: D
authors.lastname: Cameron
authors.forename: Stuart
authors.initials: S
authors.lastname: Connolly
authors.forename: David
authors.initials: D
authors.lastname: Birnie
authors.forename: Graham
authors.initials: G
authors.lastname: Nichol
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002170:Canada / Q000453:epidemiology; D016022:Case-Control Studies; D016001:Confidence Intervals; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D004632:Emergency Medical Services / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006323:Heart Arrest / Q000401:mortality* / Q000628:therapy*; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011446:Prospective Studies; D018570:Risk Assessment; D017678:Sex Distribution; D016019:Survival Analysis; D016896:Treatment Outcome