MB and myocardial infarction: At present, coronary heart disease has become one of the leading causes of mortality in China, among which acute myocardial infarction (AMI) takes the highest proportion.[1] Cardiac markers commonly used in the clinical diagnosis of AMI include creatine kinase-MB (CK-MB), cardiac troponin T (cTnT), and myoglobin, etc.[2] Previous studies showed that the significant levels of cTnT were identified around 6 hours,[3] and high- sensitivity cTnT could only be detected within 3 to 4 hours after the myocardial infarction.[4]