Haptoglobin Polymorphism as a Determinant of Adverse Outcome After Cardiac Surgery in Diabetic Patients

Specific aim 1a will test the hypothesis that diabetic patients with 2-2 haptoglobin genotype have higher indices of postoperative myocardial injury (creatine kinase MB isoenzyme , Troponin I ) and renal injury (as indicated by elevated creatinine, cytostatin C and glomerular filtration rate). Of note, significantly elevated levels (\>5 times the upper normal limit) of creatine kinase MB isoenzyme and troponins postoperatively have been associated with postoperative myocardial ischemia/infarction and are a predictor of short-term and long-term mortality after cardiac surgery. Specific aim 1b will evaluate preoperative and postoperative indices of oxidative stress (such as isoprostane f2 alpha and malondialdehyde) and will evaluate whether patients with type 2-2 haptoglobin express increased oxidative stress. The investigators will also try to correlate whether patients with increased oxidative stress are those with elevated indices of myocardial and/or renal injury Specific aim 1c will try to evaluate whether patients with type 2-2 haptoglobin also have increased levels of inflammatory indices (C-reactive protein,\[interleukin\] IL-1, IL-2, IL-6, TNF\[tumor necrosis factor\]) and try to correlate the findings with postoperative myocardial and or renal injury. The incidence of atrial fibrillation after coronary artery bypass graft ranges from 19% to 27%. The investigators will also look at any correlation of the type 2-2 haptoglobin and the incidence of post-operative atrial fibrillation.