title: Obesity is still a risk factor in coronary artery bypass surgery.
abstract: OBJECTIVE
  Even with the improvements in surgical techniques and perioperative care, obesity is still a risk factor for occurrence of adverse events following cardiac surgery. In this observational, retrospective study, we aimed to document the effects of obesity on surgical outcomes in patients undergoing coronary artery bypass surgery and find out the effects of improvements in cardiac surgery.
  
  
  METHODS
  Between January 2011 and March 2013, isolated coronary artery bypass surgery was performed on 790 patients. The body mass index values of the patients were calculated and patients were divided into two groups; below 30 were classified as non-obese group whereas above 30 were classified as obese group. The odds ratio was obtained by using univariate analysis in order to document the effects of obesity on outcomes.
  
  
  RESULTS
  There were 548 (69.3%) patients in non-obese group, whereas 242 (30.7%) patients in obese group. The cardiopulmonary bypass (80.47±23.58 vs. 80.89±28.46, p=0.449) and aortic clamp times (54.13±16.60 vs. 54.19±19.85, p=0.511) and number of bypass grafts (3.09±1.02 vs. 2.96±1.00, p=0.11) were comparable between the groups. The mean number of fresh frozen plasma used was higher in obese patients (1.37±1.75 vs. 1.48±4.63, p=0.02). Intubation time was higher in obese patients (10.57±6.87 vs. 12.71±35.31, p=0.014). Total amount of postoperative drainage was higher in non-obese patients (766.77±472.27 vs. 648.72±371.39, p<0.001). The superficial infection/mediastenitis (0.4% vs. 2.5%, p=0.012), dehiscence (0.2% vs. 3.7%, p<0.001) and postoperative renal failure rates (4.7% vs. 8.7%, p=0.031) were higher in obese patients. The incidence of atrial fibrillation was lower in obese patients (19.7% vs. 12.8%, p=0.019). The mortality (0.5% vs. 1.7%, p=0.210) and postoperative stroke rates (1.1% vs. 0.8%, p=1.000) were similar in both groups.
  
  
  CONCLUSIONS
  We documented that obesity is still a risk factor for occurrence of postoperative adverse events. We believe that improved perioperative care together with meticulous regimens can improve postoperative outcomes in patients undergoing coronary artery bypass surgery.
authors.affiliation: Clinic of Cardiovascular Surgery, Medicana International Ankara Hospital; Ankara-Turkey. barisdurukan@yahoo.com.
authors.forename: Hasan Alper
authors.initials: HA
authors.lastname: Gürbüz
authors.forename: Ahmet Barış
authors.initials: AB
authors.lastname: Durukan
authors.forename: Nevriye
authors.initials: N
authors.lastname: Salman
authors.forename: Halil İbrahim
authors.initials: Hİ
authors.lastname: Uçar
authors.forename: Cem
authors.initials: C
authors.lastname: Yorgancıoğlu
mesh_terms: D015992:Body Mass Index; D002303:Cardiac Output, Low / Q000453:epidemiology / Q000209:etiology; D001026:Coronary Artery Bypass; D006801:Humans; D009203:Myocardial Infarction / Q000401:mortality / Q000601:surgery*; D009767:Obesity, Morbid; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology; D051437:Renal Insufficiency / Q000453:epidemiology / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors