title: Long-term comparison of the implantable cardioverter defibrillator versus amiodarone: eleven-year follow-up of a subset of patients in the Canadian Implantable Defibrillator Study (CIDS).
abstract: BACKGROUND
  The implantable cardioverter defibrillator (ICD) is superior to amiodarone for secondary prophylaxis of sudden cardiac death. However, the magnitude of this benefit over long-term follow-up is not known. Thus, our objective was to evaluate the long-term consequences of using amiodarone versus an ICD as first-line monotherapy in patients with a prior history of sustained ventricular tachycardia/ventricular fibrillation or cardiac arrest.
  
  
  RESULTS
  A total of 120 patients were enrolled at St Michael's Hospital in the Canadian Implantable Defibrillator Study (CIDS) and were randomly assigned to receive either amiodarone (n=60) or an ICD (n=60). The treatment strategy was not altered after the end of CIDS unless the initial assigned therapy was not effective or was associated with serious side effects. After a mean follow-up of 5.6+/-2.6 years, there were 28 deaths (47%) in the amiodarone group, compared with 16 deaths (27%) in the ICD group (P=0.0213). Total mortality was 5.5% per year in the amiodarone group versus 2.8% per year in the ICD group (hazard ratio of amiodarone: ICD, 2.011; 95% confidence interval, 1.087 to 3.721; P=0.0261). In the amiodarone group, 49 patients (82% of all patients) had side effects related to amiodarone, of which 30 patients (50% of all patients) required discontinuation or dose reduction; 19 patients crossed over to ICD because of amiodarone failure (n=7) or side effects (n=12).
  
  
  CONCLUSIONS
  In a subset of CIDS, the benefit of the ICD over amiodarone increases with time; most amiodarone-treated patients eventually develop side effects, have arrhythmia recurrences, or die.
authors.affiliation: Terrence Donnelly Heart Center, Department of Medicine, St Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: Fayez
authors.initials: F
authors.lastname: Bokhari
authors.forename: David
authors.initials: D
authors.lastname: Newman
authors.forename: Mary
authors.initials: M
authors.lastname: Greene
authors.forename: Victoria
authors.initials: V
authors.lastname: Korley
authors.forename: Iqwal
authors.initials: I
authors.lastname: Mangat
authors.forename: Paul
authors.initials: P
authors.lastname: Dorian
mesh_terms: D000368:Aged; D000638:Amiodarone / Q000008:administration & dosage / Q000009:adverse effects / Q000191:economics / Q000627:therapeutic use*; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000191:economics / Q000627:therapeutic use*; D002170:Canada / Q000453:epidemiology; D015897:Comorbidity; D001026:Coronary Artery Bypass; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000517:prevention & control; D017147:Defibrillators, Implantable / Q000191:economics / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015993:Life Tables; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000188:drug therapy / Q000628:therapy; D016019:Survival Analysis; D017180:Tachycardia, Ventricular / Q000188:drug therapy / Q000628:therapy*; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000188:drug therapy / Q000628:therapy*
chemical_list: D000889:Anti-Arrhythmia Agents; D000638:Amiodarone