title: Off-pump versus on-pump coronary revascularization: meta-analysis of mid- and long-term outcomes.
abstract: BACKGROUND
  Early outcomes for off-pump coronary artery bypass grafting (OPCAB) have been extensively compared with on-pump coronary revascularization (ONCAB); however, the long-term effects of OPCAB continue to be debated. This study aims to compare the mid-term (>1year; ≤5 years) and long-term (>5 years) survival and major adverse cardiovascular and cerebrovascular events of OPCAB versus ONCAB.
  
  
  METHODS
  A systematic search identified 32 studies meeting our inclusion criteria. These were analyzed using random effects modeling, with subgroup evaluation according to study type. Primary outcomes were mid- and long-term survival over a follow-up period greater than 1 year. Secondary outcomes were mid- and long-term events including repeat revascularization, myocardial infarction, angina, heart failure, and cerebrovascular accidents.
  
  
  RESULTS
  Off-pump coronary artery bypass grafting confers similar overall mid-term survival when compared with ONCAB (hazard ratio, 1.06; 95% confidence interval, 0.95 to 1.19; p=0.31). On-pump coronary artery bypass grafting was associated with a significant trend towards a long-term survival advantage (hazard ratio, 1.06; 95% confidence interval, 1.00 to 1.13; p=0.05); however, this was no longer present when subgroup analysis of only randomized controlled trials, registry-based studies, and propensity-matched studies was performed. There was an increase in angina recurrence among two studies after OPCAB, but no difference was seen in 11 other studies reporting data as odds ratio. No significant differences were observed in other secondary outcomes.
  
  
  CONCLUSIONS
  This analysis demonstrates comparable mid-term mortality and mid- to long-term morbidity between OPCAB and ONCAB. On-pump coronary artery bypass grafting may be associated with improved long-term survival when all study types are analyzed; however, analysis of only randomized controlled trials and propensity-matched studies demonstrates comparable long-term mortality between OPCAB and ONCAB.
authors: Department of Surgery and Cancer, Imperial College London, London, United Kingdom.
authors: Umar A R
authors: UA
authors: Chaudhry
authors: Department of Surgery and Cancer, Imperial College London, London, United Kingdom.
authors: Leanne
authors: L
authors: Harling
authors: Department of Surgery and Cancer, Imperial College London, London, United Kingdom.
authors: Christopher
authors: C
authors: Rao
authors: Department of Surgery and Cancer, Imperial College London, London, United Kingdom.
authors: Hutan
authors: H
authors: Ashrafian
authors: Department of Surgery and Cancer, Imperial College London, London, United Kingdom.
authors: Michael
authors: M
authors: Ibrahim
authors: Second Department of Cardiac Surgery, Evangelismos General Hospital, Athens, Greece.
authors: John
authors: J
authors: Kokotsakis
authors: Department of Surgery and Cancer, Imperial College London, London, United Kingdom.
authors: Roberto
authors: R
authors: Casula
authors: Department of Surgery and Cancer, Imperial College London, London, United Kingdom. Electronic address: t.athanasiou@imperial.ac.uk.
authors: Thanos
authors: T
authors: Athanasiou
mesh_terms: D001026:Coronary Artery Bypass; D047549:Coronary Artery Bypass, Off-Pump; D003324:Coronary Artery Disease / Q000401:mortality / Q000601:surgery*; D006801:Humans; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome