title: Adjunctive antiarrhythmic drug therapy in patients with implantable cardioverter defibrillators: a systematic review.
abstract: OBJECTIVE
  To assess the efficacy and safety of adjunctive antiarrhythmic drug therapy for preventing implantable cardioverter defibrillator (ICD) therapies.
  
  
  RESULTS
  We conducted a systematic literature search to identify all randomized, controlled trials assessing the efficacy of adjunctive antiarrhythmic drug therapy. Trial data were reviewed and extracted independently by two investigators in an unblinded, standardized manner. Eight trials including a total of 1889 patients were analysed. There was heterogeneity in the type of antiarrhythmic used in the treatment arm (amiodarone, sotalol, azimilide, and dofetilide) as well as in the control group (five trials compared with placebo and three trials compared with beta-blocker). The main outcome, risk of shock therapy, was reduced when comparing amiodarone plus beta-blocker with beta-blocker alone (HR 0.27; 95% CI 0.14-0.52) and when comparing sotalol with placebo (HR 0.55; 95% CI 0.4-0.78). The effect was not conclusive when comparing sotalol with other beta-blocker (HR 0.61; 95% CI 0.37-1) and azimilide or dofetilide with placebo (HR 0.78; 95% CI 0.58-1.04 and HR 0.67; 95% CI 0.43-1.04, respectively). Although there were some benefits for secondary outcomes in all antiarrhythmics, the magnitude of the benefit was higher with amiodarone.
  
  
  CONCLUSIONS
  Amiodarone is the most effective treatment to reduce ICD shock therapies. The benefit of other antiarrhythmics is limited to secondary outcomes.
authors.affiliation: Epidemiology Unit, Department of Cardiology, Paseo Vall d'Hebron Hospital, Barcelona 119-129, 08035, Spain, and Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada. nacho_ferreira@hotmail.com
authors.forename: Ignacio
authors.initials: I
authors.lastname: Ferreira-González
authors.forename: Laura
authors.initials: L
authors.lastname: Dos-Subirá
authors.forename: Gordon H
authors.initials: GH
authors.lastname: Guyatt
mesh_terms: D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001145:Arrhythmias, Cardiac / Q000628:therapy*; D017024:Chemotherapy, Adjuvant; D002986:Clinical Trials as Topic; D017147:Defibrillators, Implantable; D006801:Humans; D016896:Treatment Outcome
chemical_list: D000889:Anti-Arrhythmia Agents