TNNI3 and myocardial infarction: cTnI is the gold standard biomarker for detecting cardiac injury and necrosis of cardiomyocyte, and is highly specific for cardiac injury, and persistent elevation of troponin I is associated with greater left ventricular dysfunction and a higher rate of cardiac events27, which are combined with the myocardial infarction area to assess the degree of myocardial damage.