Myocardial infarction after CABG is a serious complication and one of the most common causes of morbidity and mortality. The study enrolled 250 consecutive patients undergone isolated CABG at the National Heart Institute, Cairo, Egypt and Benha University hospital, Benha, Egypt in the period from November 2013 to May 2014 (6 months). To determine the incidence of perioperative myocardial infarction and to detect predictors in hospital and 30 days clinical outcome related to perioperative myocardial infarction by using hs-TnI and evaluated the utility of adding to the troponin criteria new Q-waves or imaging evidence of new wall motion abnormality as suggested in the Universal Definition of MI.