TNNI3 and infarction: Clinically, after myocardial ischemia-reperfusion injury, plasma cTnI is significantly increased, accompanied by a large area of cTnI loss in myocardial tissue, and plasma cTnI level will increase with the prolonged ischemia time (50), and the missing area will increase with the time of myocardial ischemia or infarction (51).