title: Effect of obesity on short- and long-term mortality postcoronary revascularization: a meta-analysis.
abstract: OBJECTIVE
  Overweight and obesity are often assumed to be risk factors for postprocedural mortality in patients with coronary artery disease (CAD). However, recent studies have described an "obesity paradox" -- a neutral or beneficial association between obesity and mortality postcoronary revascularization. We reviewed the effect of overweight and obesity systematically on short- and long-term all-cause mortality post-coronary artery bypass grafting (CABG) and post-percutaneous coronary intervention (PCI).
  
  
  METHODS
  We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Scopus, and Web of Science to identify cohort, case control, and randomized controlled studies evaluating the effect of obesity on in-hospital/short-term (within 30 days) and long-term (up to 5 years) mortality. Full-text, published articles reporting all-cause mortality between individuals with and without elevated BMI were included. Two reviewers independently assessed studies for inclusion and performed data extraction.
  
  
  RESULTS
  Twenty-two cohort publications were identified, reporting results in ten post-PCI and twelve post-CABG populations. Compared to individuals with non-elevated BMI levels, obese patients undergoing PCI had lower short- (odds ratio (OR) 0.63; 95% confidence interval (CI) 0.54-0.73) and long-term mortality (OR 0.65; 95% CI 0.51-0.83). Post-CABG, obese patients had lower short-term (OR 0.63; 95% CI 0.56-0.71) and similar long-term (OR 0.88; 95% CI 0.60-1.29) mortality risk compared to normal weight individuals. Results were similar in overweight patients for both procedures.
  
  
  CONCLUSIONS
  Compared to non-obese individuals, overweight and obese patients have similar or lower short- and long-term mortality rates postcoronary revascularization. Further research is needed to confirm the validity of these findings and delineate potential underlying mechanisms.
authors.affiliation: Division of Cardiothoracic Surgery, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Antigone
authors.initials: A
authors.lastname: Oreopoulos
authors.forename: Raj
authors.initials: R
authors.lastname: Padwal
authors.forename: Colleen M
authors.initials: CM
authors.lastname: Norris
authors.forename: John C
authors.initials: JC
authors.lastname: Mullen
authors.forename: Victor
authors.initials: V
authors.lastname: Pretorius
authors.forename: Kamyar
authors.initials: K
authors.lastname: Kalantar-Zadeh
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000401:mortality*; D001026:Coronary Artery Bypass / Q000009:adverse effects; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009204:Myocardial Revascularization / Q000401:mortality*; D009765:Obesity / Q000150:complications*; D016017:Odds Ratio; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013997:Time Factors; D016896:Treatment Outcome