title: Obesity and postoperative atrial fibrillation in patients undergoing cardiac surgery: Systematic review and meta-analysis.
abstract: BACKGROUND
  Post-operative atrial fibrillation (POAF) is one of the most common complications following cardiac surgery. However, it is unclear whether there is a relationship between obesity and POAF. We thus assessed all available evidence investigating the association between obesity and POAF, also considering any link between POAF and other post-operative conditions such as mortality, stroke, myocardial infarctions and respiratory complications.
  
  
  METHODS
  Five electronic databases were searched and relevant studies were identified. Data was extracted and meta-analyzed from the identified studies.
  
  
  RESULTS
  We found that obese patients had significantly higher odds of POAF when compared with non-obese patients (P=0.006). There was also significant heterogeneity among the identified studies. POAF when compared with no-POAF was associated with an increased risk of stroke (P<0.0001), 30-day mortality (P=0.005) and respiratory complications (P<0.00001). However, we found no significant link between POAF and myocardial infarctions (P=0.79).
  
  
  CONCLUSIONS
  Our findings suggest that obesity is associated with a moderately higher risk of POAF. While POAF is also associated with an increased incidence of stroke, 30-day mortality and respiratory complications, further studies must be conducted before conclusions can be made about the long-term outcomes.
authors.affiliation: The Collaborative Research (CORE) Group, Macquarie University, Sydney, Australia. Electronic address: kphan.vc@gmail.com.
authors.forename: Kevin
authors.initials: K
authors.lastname: Phan
authors.affiliation: The Collaborative Research (CORE) Group, Macquarie University, Sydney, Australia.
authors.forename: Jacqueline Nguyen
authors.initials: JN
authors.lastname: Khuong
authors.affiliation: The Collaborative Research (CORE) Group, Macquarie University, Sydney, Australia.
authors.forename: Joshua
authors.initials: J
authors.lastname: Xu
authors.affiliation: The Collaborative Research (CORE) Group, Macquarie University, Sydney, Australia.
authors.forename: Aran
authors.initials: A
authors.lastname: Kanagaratnam
authors.affiliation: The Collaborative Research (CORE) Group, Macquarie University, Sydney, Australia.
authors.forename: Tristan D
authors.initials: TD
authors.lastname: Yan
mesh_terms: D001281:Atrial Fibrillation / Q000209:etiology*; D006348:Cardiac Surgical Procedures / Q000009:adverse effects* / Q000401:mortality; D002318:Cardiovascular Diseases / Q000601:surgery*; D016206:Databases, Bibliographic; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000150:complications / Q000453:epidemiology*; D011184:Postoperative Period; D012307:Risk Factors
keywords: AF; Atrial fibrillation; Body mass index; Obesity; Postoperative atrial fibrillation