title: Primary Prevention Implantable Cardioverter Defibrillators in Patients With Nonischemic Cardiomyopathy: A Meta-analysis.
abstract: Conflicting data have emerged on the efficacy of implantable cardioverter defibrillators (ICDs) for primary prevention of sudden cardiac death (primary prevention ICDs) in patients with nonischemic cardiomyopathy.
  
  
  
  To investigate the association of primary prevention ICDs with all-cause mortality in patients with nonischemic cardiomyopathy.
  
  
  
  PubMed was searched from January 1, 2000, through October 31, 2016, for the terms implantable defibrillator OR implantable cardioverter defibrillator AND non-ischemic cardiomyopathy. Additional references were identified from bibliographies of pertinent articles and queries to experts in this field.
  
  
  
  Inclusion criteria consisted of a randomized clinical trial design and comparison of the ICD with medical therapy (control) in at least 100 patients with nonischemic cardiomyopathy. In addition, studies had to report on all-cause mortality during a follow-up period of at least 12 months and be published in English. The search yielded 10 studies, of which only 1 met the inclusion criteria. A search of bibliographies of pertinent articles and queries of experts in this field led to 3 additional studies.
  
  
  
  The PRISMA guidelines were used to abstract data and assess data quality and validity. Data were pooled using fixed- and random-effects models.
  
  
  
  The primary end point was all-cause mortality. Before data collection started, primary prevention ICDs were hypothesized to reduce all-cause mortality among patients with nonischemic cardiomyopathy.
  
  
  
  Four randomized clinical trials met the selection criteria and included 1874 unique patients; 937 were in the ICD group and 937 in the control group. Pooling data from these trials showed a significant reduction in all-cause mortality with an ICD (hazard ratio, 0.75; 95% CI, 0.61-0.93; P = .008; P = .87 for heterogeneity).
  
  
  
  Primary prevention ICDs are efficacious at reducing all-cause mortality among patients with nonischemic cardiomyopathy. These findings support professional guidelines that recommend the use of ICDs in such patients.
authors.affiliation: Division of Cardiology, Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina.
authors.forename: Sana M
authors.initials: SM
authors.lastname: Al-Khatib
authors.affiliation: Division of Cardiology, UCLA (University of California, Los Angeles).
authors.forename: Gregg C
authors.initials: GC
authors.lastname: Fonarow
authors.affiliation: Division of Cardiology, University of Texas Southwestern, Dallas.
authors.forename: Jose A
authors.initials: JA
authors.lastname: Joglar
authors.affiliation: Department of Biostatistics, University of Washington, Seattle.
authors.forename: Lurdes Y T
authors.initials: LYT
authors.lastname: Inoue
authors.affiliation: Division of Cardiology, Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Mark
authors.affiliation: Department of Biostatistics and Bioinformatics, Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina.
authors.forename: Kerry L
authors.initials: KL
authors.lastname: Lee
authors.affiliation: Division of Cardiology, Feinberg School of Medicine, Northwestern Memorial Hospital, Chicago, Illinois.
authors.forename: Alan
authors.initials: A
authors.lastname: Kadish
authors.affiliation: Division of Cardiology, University of Washington, Seattle.
authors.forename: Gust
authors.initials: G
authors.lastname: Bardy
authors.affiliation: Department of Clinical Pharmacology, Duke Clinical Research Institute, Duke University Medical Center, Durham, North Carolina.
authors.forename: Gillian D
authors.initials: GD
authors.lastname: Sanders
mesh_terms: D009202:Cardiomyopathies / Q000628:therapy*; D002423:Cause of Death; D016757:Death, Sudden, Cardiac / Q000517:prevention & control*; D017147:Defibrillators, Implantable; D006333:Heart Failure / Q000628:therapy*; D006801:Humans; D009026:Mortality; D011322:Primary Prevention; D016016:Proportional Hazards Models; D016032:Randomized Controlled Trials as Topic