title: All cause mortality of cardiac resynchronization therapy with implantable cardioverter defibrillator: a meta-analysis of randomized controlled trials.
abstract: OBJECTIVE
  Cardiac resynchronization therapy with implantable cardioverter defibrillator (CRT-D) has been shown to improve symptoms in patients with chronic heart failure (CHF). However, reduction of all cause mortality is being debated. To evaluate whether CRT-D reduces all cause mortality compared with no-CRT-D in patients with CHF, a meta-analysis of randomized controlled trials was performed.
  
  
  METHODS
  Data sources are MEDLINE (1994-2008), EMBASE (1994-2008), the Cochrane Controlled Trials Register (Second Quarter, 2008), the National Institutes of Health Clinical Trials.gov database of clinical trials and the US Food and Drug Administration Website (1994-2008). Search terms included cardiac resynchronization therapy with implantable cardioverter defibrillator, biventricular implantable cardioverter defibrillator, cardiac resynchronization therapy, and CRT-D.
  
  
  METHODS
  Two reviewers independently assessed trial eligibility and quality. Eligible studies were randomized controlled trials of CRT-D for the treatment of CHF. Eligible studies reported all cause deaths as outcomes. Seven randomized trials were included in the meta-analysis, comparing CRT-D with no-CRT-D. The outcome was all cause mortality.
  
  
  RESULTS
  A total of 747 events occurred in 4531 patients from seven randomized trials. Follow-up in the included trials ranged from 6 to 69 months. Most trials were high-quality. Pooled analysis demonstrated CRT-D significantly reduced all cause mortality (odds ratios (OR) 0.55, 95% confidence interval 0.40 to 0.76, P=0.0002). Subgroup analysis CRT-D vs CRT alone and CRT-D vs medical therapy alone, significantly reduced all cause mortality (OR 0.48, 95% confidence interval 0.31 to 0.75, P=0.001; OR 0.64, 95% confidence interval 0.46 to 0.90, P=0.009; respectively).
  
  
  CONCLUSIONS
  CRT-D significantly reduces all cause mortality in patients with advanced CHF.
authors.affiliation: Department of Cardiology, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, People's Republic of China.
authors.forename: Yanlan
authors.initials: Y
authors.lastname: Huang
authors.forename: Weifeng
authors.initials: W
authors.lastname: Wu
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Cao
authors.forename: Nan
authors.initials: N
authors.lastname: Qu
mesh_terms: D058406:Cardiac Resynchronization Therapy / Q000401:mortality*; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D006333:Heart Failure / Q000401:mortality* / Q000628:therapy*; D006801:Humans; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data