title: Off-pump coronary artery bypass may increase late mortality: a meta-analysis of randomized trials.
abstract: BACKGROUND
  Although a lot of randomized trials of off-pump coronary artery bypass grafting (CABG) versus on-pump CABG were conducted, the majority of them reported only early outcomes. Previous meta-analyses of a few randomized trials found no differences for 1-year to 2-year mortality.
  
  
  METHODS
  We focused late (> or = 1 year) all-cause mortality and performed a meta-analysis of randomized controlled trials of off-pump versus on-pump CABG. The MEDLINE, the EMBASE, and the Cochrane Central Register of Controlled Trials were searched using PubMed and OVID. For each study, data regarding all-cause mortality in both the off-pump and on-pump groups were used to generate risk ratios (RRs) and 95% confidence intervals. Study-specific estimates were combined using inverse variance-weighted averages of logarithmic RRs in both fixed-effects and random-effects models.
  
  
  RESULTS
  Our search identified 11 results of 12 randomized trials (4,326 patients) of off-pump versus on-pump CABG. Pooled analysis demonstrated a statistically significant increase in midterm all-cause mortality by a factor of 1.37 with off-pump relative to on-pump CABG (RR, 1.373; 95% confidence interval, 1.043 to 1.808). Exclusion of any single result, except for the largest (>2,000 patients) trial, from the analysis did not substantively alter the overall result of our analysis. Eliminating the largest trial demonstrated a statistically nonsignificant benefit of on-pump over off-pump CABG for midterm all-cause mortality (RR, 1.344; 95% confidence interval, 0.952 to 1.896).
  
  
  CONCLUSIONS
  The results of our analysis suggest that off-pump CABG may increase late all-cause mortality by a factor of 1.37 over on-pump CABG. Longer term mortality from randomized trials of off-pump versus on-pump CABG is needed.
authors.affiliation: Department of Cardiovascular Surgery, Shizuoka Medical Center, Shizuoka, Japan. kfgth973@ybb.ne.jp
authors.forename: Hisato
authors.initials: H
authors.lastname: Takagi
authors.forename: Masafumi
authors.initials: M
authors.lastname: Matsui
authors.forename: Takuya
authors.initials: T
authors.lastname: Umemoto
mesh_terms: D047549:Coronary Artery Bypass, Off-Pump / Q000401:mortality*; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D013997:Time Factors