Myoglobin and C5b9 immunohistochemistry studies in heart tissue from sudden unexpected natural death cases

The post-mortem diagnosis for acute myocardial infarction is one of the most challenging because acute myocardial infarction in the first 4 hours does not provide specific changes. Hence, this research evaluated the effectiveness of immunohistochemistry staining for detecting early myocardial infarction. Immunohistochemical staining for myoglobin and C5b9 were conducted on myocardial tissue from four groups with the following criteria: 1. Acute myocardial infarction cases (18 cases, positive control), 2. Severe coronary atherosclerosis cases (19 cases), 3. Natural deaths with unknown cause of death (12 cases), 4. Negative control. The results were that myoglobin staining was found positive in 17 cases of group 1 (94.4%), 13 cases of group 2 (68.4%), 3 cases of group 3 (25%), and 6 cases of group 4 (60%). C5b9 staining was found positive in 18 cases of group 1(100%), 10 cases of group 2 (52.6%), 4 cases of group 3 (33.3%), and 7 cases of group 4 (70%). The results showed that no statistical significance was found in a comparative analysis between group 4 and group 2. Hence, the results of staining for C5b9 and myoglobin conflict with the findings of prior research because the specificity in identifying acute myocardial infarction was low.