77. High preoperative myocardial ischemia biomarkers as predictors of postoperative mortality after CABG surgery: Short and mid term outcome of tertiary center experience

Abstract

To evaluate the predictivity of preoperative serum myocardial ischemia biomarkers for postoperative (PO) mortality in patients undergoing coronary artery bypass grafting (CABG) surgery. Patients & methods: The study included 300 patients with mean age of 62.2 ± 4.2 years. Patients were evaluated for preoperative risk factors and donated fasting blood samples for ELISA estimation of preoperative serum levels of creatinine (sCr), cardiac troponin T (cTnT) and cTnI and Creatine Kinase-myoband (CK-MB) Isoenzyme. Intraoperative and PO complications were determined. The 30-day PO mortality rate and total mortality rate at the end of follow-up period were determined. Results: All surgeries were conducted successfully without intraoperative mortalities or complications. One patient died during the 1st 30-days after surgery, 11 patients died during a mean follow-up period of 22 month for a follow-up mortality rate of 3.7% and a total mortality rate of 4%. Non-survivors were significantly (p < 0.05) older, had increased frequency of associated co-morbidities and significantly higher serum levels of CK-MB, cTnT and cTnI. Concerning operative data, non-survivors consumed significantly longer theater time with significantly longer aortic clamping and CPB times. The ROC curve analysis defined old age, high preoperative cTnT serum levels, number of diseased vessels, high preoperative cTnI serum levels high preoperative CK-MB serum level, preoperative low left ventricle ejection fraction (LVEF), high preoperative serum creatinine and intraoperative aortic clamping time were specific predictors for PO mortality in descending significance. Regression analysis defined high preoperative serum cTnT and CK-MB and old age the most significant specific predictors of PO mortality. Conclusion: Old age, multiple diseased vessels and low left ventricular ejection fraction in conjunction with high preoperative serum levels of myocardial ischemia biomarkers could predict PO mortality after CABG surgery. However, high preoperative troponin levels were significantly superior predictor for PO mortality than CK-MB.