title: Cardiac resynchronisation for patients with heart failure due to left ventricular systolic dysfunction -- a systematic review and meta-analysis.
abstract: BACKGROUND
  Randomised controlled trials generally suggest that cardiac resynchronisation improves outcomes in patients with heart failure due to left ventricular systolic dysfunction and cardiac dyssynchrony. Our objective was to provide a valid synthesis of the effects of CRT on mortality, major morbidity, quality of life and implantation success rates.
  
  
  METHODS
  Systematic overview and meta-analysis of randomised trials, both blinded and open, comparing cardiac resynchronisation with control. The primary outcome was all-cause mortality, and secondary outcomes included hospitalisation for worsening heart failure, quality of life and implantation success rates.
  
  
  RESULTS
  We identified 8 randomised trials which included 3380 patients and observed a total of 524 deaths. Follow-up ranged from 1 month to a mean of 29.4 months. Most trials were of high quality, with centrally administered randomisation and few patients lost to follow-up. CRT reduced mortality in these trials (odds ratio 0.72, 95% CI 0.59 to 0.88). In addition CRT reduced hospitalisation for worsening heart failure (odds ratio 0.55, 95% CI 0.44 to 0.68) and improved quality of life as measured by the Minnesota Living with Heart Failure Questionnaire (weighted mean difference -7.1, 95% CI -2.9 to -11.4). Implantation success rates in the trials were 87% or greater.
  
  
  CONCLUSIONS
  Cardiac resynchronisation in patients with heart failure characterised by dyssynchrony substantially reduces all-cause mortality, major morbidity and improves quality of life.
authors.affiliation: Clinical Epidemiology and Biostatistics, Department of Primary Care and General Practice, Primary Care Clinical Sciences Building, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK. N.Freemantle@bham.ac.uk
authors.forename: N
authors.initials: N
authors.lastname: Freemantle
authors.forename: P
authors.initials: P
authors.lastname: Tharmanathan
authors.forename: M J
authors.initials: MJ
authors.lastname: Calvert
authors.forename: W T
authors.initials: WT
authors.lastname: Abraham
authors.forename: J
authors.initials: J
authors.lastname: Ghosh
authors.forename: J G F
authors.initials: JG
authors.lastname: Cleland
mesh_terms: D002303:Cardiac Output, Low / Q000503:physiopathology*; D006801:Humans; D011788:Quality of Life; D011795:Surveys and Questionnaires; D013599:Systole; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*