<qa>  What is the name of the early marker of myocardial injury?The objective is to estimate the association between biomarkers of myocardial injury and myocardial infarction in patients undergoing cardiac surgery. Myocardial infarction will be established with both a new and very early marker of myocardial injury Heart-type Fatty Acid Binding Proteins as well as to a known early marker of such injury Cardiac troponin. 