title: Off-pump versus on-pump revascularization in females: a meta-analysis of observational studies.
abstract: BACKGROUND
  Coronary revascularization in female patients presents several challenges, including smaller target vessels and smaller conduits. Furthermore, late presentation and more co-morbidities than males may increase complication rates. The aim of this study was to assess whether off-pump coronary artery bypass (OPCAB) improves outcomes when compared to on-pump coronary artery bypass (ONCAB) in the female population.
  
  
  METHODS
  A systematic literature review identified six observational studies, incorporating 23313 patients (n=9596 OPCAB, 13717 ONCAB). These were meta-analyzed using random effects modeling. Heterogeneity, subgroup analysis, quality scoring and publication bias were assessed. The primary endpoints were 30-day mortality and major cardiac, respiratory and renal complications. Secondary endpoints were the number of grafts per patient.
  
  
  RESULTS
  No statistically significant difference was observed in 30-day mortality between the OPCAB and ONCAB groups (4.8% vs. 0.7%; OR 0.96; 95% CI [0.41, 2.24], p=0.92). Significant inter-study heterogeneity was also present (I2=94%) and was not explained by study size or quality. Peri-operative myocardial infarction (OR 0.65; 95% CI [0.51, 0.84], p=0.0009) was significantly lower with OPCAB without significant heterogeneity; however, OPCAB did not significantly alter other morbidity outcomes. OPCAB was associated with a trend towards fewer grafts per patient than ONCAB.
  
  
  CONCLUSIONS
  OPCAB is a safe alternative to ONCAB in the surgical revascularisation of female patients and may reduce post-operative myocardial infarction (MI). However, this does not translate into a reduction in 30-day mortality and OPCAB does not significantly improve other cardiovascular, renal or neurological outcomes. Late outcome data remains lacking and a well-structured, randomized trial is required to answer vital questions regarding the effect of OPCAB on women in the long-term.
authors.affiliation: Department of Cardiothoracic Surgery, Imperial College Healthcare NHS Trust, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Attaran
authors.affiliation: Department of Surgery and Cancer, Imperial College London, UK.
authors.forename: L
authors.initials: L
authors.lastname: Harling
authors.affiliation: Department of Surgery and Cancer, Imperial College London, UK.
authors.forename: H
authors.initials: H
authors.lastname: Ashrafian
authors.affiliation: Department of Cardiothoracic Surgery, Imperial College Healthcare NHS Trust, London, UK.
authors.forename: M
authors.initials: M
authors.lastname: Moscarelli
authors.affiliation: Department of Cardiothoracic Surgery, Imperial College Healthcare NHS Trust, London, UK.
authors.forename: R
authors.initials: R
authors.lastname: Casula
authors.affiliation: Department of Cardiothoracic Surgery, Imperial College Healthcare NHS Trust, London, UK.
authors.forename: J
authors.initials: J
authors.lastname: Anderson
authors.affiliation: Department of Cardiothoracic Surgery, Imperial College Healthcare NHS Trust, London, UK.
authors.forename: P
authors.initials: P
authors.lastname: Punjabi
authors.affiliation: Department of Surgery and Cancer, Imperial College London, UK Leanne.harling@imperial.ac.uk.
authors.forename: T
authors.initials: T
authors.lastname: Athanasiou
mesh_terms: D047549:Coronary Artery Bypass, Off-Pump / Q000009:adverse effects / Q000379:methods*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000401:mortality / Q000517:prevention & control*; D064887:Observational Studies as Topic; D015996:Survival Rate; D013997:Time Factors
keywords: CABG; cardiac surgery; off-pump CABG; women