title: Relationship Between Diabetic Variables and Outcomes After Coronary Artery Bypass Grafting in Diabetic Patients.
abstract: BACKGROUND
  Nearly half of the patients undergoing coronary artery bypass grafting (CABG) have diabetes. There is mixed data as to whether preoperative (haemoglobin A1c{HbA1c}) and/or perioperative diabetes control is associated with mortality and morbidity after CABG. We reviewed the characteristics and outcomes of diabetic patients undergoing CABG with a focus on HbA1c, perioperative glucose levels and diabetic treatment regimens.
  
  
  METHODS
  Diabetic patients undergoing CABG during July 2010 to June 2012 were studied (n=306). The last preoperative HbA1c levels, and perioperative glucose levels (mean and coefficient of variation {CV}) were retrospectively recorded, as well as the pre-existing and perioperative diabetes treatment regimens for analyses.
  
  
  RESULTS
  Mean HbA1c was 7.7+/-1.6%, and 11.1% (34), 56.2% (172), and 32.7% (100) of patients were managed preoperatively with diet only, oral diabetic medications and insulin respectively. For operative mortality which occurred in 2.0%, C-statistics (95% confidence interval) was only significant for HbA1c, 0.855 (0.757-0.975), and glucose CV on the day of surgery, 0.722 (0.567-0.877). HbA1c also detected postoperative renal failure, C-statistic 0.617 (0.504-0.730), but not other complications or mortality during follow-up. In multivariate analysis, HbA1c was the only diabetes-related independent predictor of operative mortality, hazards ratio 4.13 (1.04-16.4), and none of the diabetes-related variables predicted mortality during follow-up or other postoperative complications.
  
  
  CONCLUSIONS
  Preoperative HbA1c was the only diabetic variable to independently predict operative mortality after CABG, suggesting medium-term preoperative diabetes control is more important and prognostic of operative outcomes than perioperative diabetes control.
authors: Green Lane Cardiovascular Service, Auckland City Hospital, Auckland, New Zealand. Electronic address: TWang@adhb.govt.nz.
authors: Tom Kai Ming
authors: TK
authors: Wang
authors: Green Lane Cardiovascular Service, Auckland City Hospital, Auckland, New Zealand.
authors: Andrew
authors: A
authors: Woodhead
authors: Green Lane Cardiovascular Service, Auckland City Hospital, Auckland, New Zealand.
authors: Tharumenthiran
authors: T
authors: Ramanathan
authors: Green Lane Cardiovascular Service, Auckland City Hospital, Auckland, New Zealand.
authors: James
authors: J
authors: Pemberton
mesh_terms: D000368:Aged; D001786:Blood Glucose / Q000378:metabolism*; D001026:Coronary Artery Bypass; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000401:mortality*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human
keywords: Cardiac surgery; Coronary artery bypass grafting; Diabetes mellitus