Hematoxylin and Eosin (H&E) stained slides and fibronectin, CD59, myoglobulin, troponin T, desmin, cathepsin S stained slides of 20 cases diagnosed with early myocardial infarction were retrospectively re-examined. The diagnosis of myocardial infarction was analyzed in two groups: Group 1: first eight hours, Group 2: 8-24 hours. Here, CTSS is linked to myocardial infarction.