title: Predictors of perioperative mortality after coronary artery bypass grafting in the elderly.
abstract: BACKGROUND
  Coronary artery bypass grafting (CABG) is associated with higher operative risk in the elderly compared to younger patients. The aim of this study was to evaluate risk factors for perioperative mortality after CABG in the elderly.
  
  
  METHODS
  We investigated 325 consecutive patients aged 75 or over undergoing isolated CABG at our institution. We analyzed the patients' characteristics and perioperative outcome. Patients were divided into survivors and non-survivors; risk factors and complications were compared. Based on this, we performed a multivariate logistic regression analysis to determine independent risk factors for perioperative mortality.
  
  
  RESULTS
  Non-survivors of CABG more often suffered from concomitant extracardiac atherosclerosis (non-survivors, 62.2 %; survivors, 40.6 %; p = 0.013) as well as from renal insufficiency preoperatively (non-survivors, 35.1 %; survivors 8.0 %; p < 0.0001). A trend towards higher incidences of impaired left ventricular function (non-survivors, 37.8 %; survivors, 29.9 %; p = 0.105) and a history of recent myocardial infarction (non-survivors, 29.7 %; survivors, 17.0 %; p = 0.061) were found in non-survivors compared to survivors. Furthermore, non-survivors more often underwent CABG with cardiopulmonary bypass (CPB non-survivors, 96.1 %; survivors 70.6 %; p = 0.0005). Multivariate logistic regression analysis revealed that preoperatively impaired renal function (OR: 2.857, p < 0.0001), use of CPB (OR: 5.952, p = 0.0175), extracardiac atherosclerosis (OR: 1.581, p = 0.0228), and recent myocardial infarction (OR: 1.574, p = 0.0405) were independent risk factors for perioperative mortality. Comparison of patients undergoing CABG with or without CPB reveals that patients operated without CPB had a higher preoperative risk than patients undergoing CABG with CPB.
  
  
  CONCLUSIONS
  These results show that besides impaired renal function, extracardiac atherosclerosis, and history of recent myocardial infarction, the use of CPB is a major risk factor for CABG in the elderly. Perioperative mortality and morbidity can be significantly reduced if CPB is avoided.
authors.affiliation: Department of Cardiothoracic Surgery, Vienna General Hospital, University of Vienna, Vienna, Austria. juliane.kilo@akh-wien.ac.at
authors.forename: J
authors.initials: J
authors.lastname: Kilo
authors.forename: M
authors.initials: M
authors.lastname: Czerny
authors.forename: D
authors.initials: D
authors.lastname: Zimpfer
authors.forename: M
authors.initials: M
authors.lastname: Gorlitzer
authors.forename: E
authors.initials: E
authors.lastname: Wolner
authors.forename: M
authors.initials: M
authors.lastname: Grimm
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002315:Cardiopulmonary Bypass / Q000401:mortality*; D001026:Coronary Artery Bypass / Q000401:mortality*; D006801:Humans; D012189:Retrospective Studies; D012307:Risk Factors; D017741:Survivors / Q000706:statistics & numerical data; D016896:Treatment Outcome