The results of this study showed that the levels of CK-MB and cTnI, myocardial infarction area, and Gensini score of patients in the mild decline group and the severe decline group were significantly higher than those of the normal group, and the LVEF value was significantly lower than that of the normal group, and the CK level of patients in the severe decline group was significantly higher than that in the normal group. Here, TNNI3 is linked to myocardial infarction.