Medicolegal Use of Troponin C Expression to Identify Different Causes of Cardiac Deaths at Different Postmortem Intervals

Abstract

Identification of the exact cause and time of death are important questions that have to be answered by the forensic pathologist. Traumatic cardiac injuries is a leading cause of death. This work aimed at using cardiac troponin C (cTnC) expression to differentiate between different types of cardiac injuries at different postmortem intervals (PMI). This study was performed on 90 forensic autopsies selected in the Medicolegal Department of Ministry of Justice. The cases were divided equally into 5 groups of different causes of death i.e. non-cardiac causes of death (control group), blunt cardiac injury (BCI), civilian cardiac firearm injury, civilian stab injury and sudden cardiac death (SCD). Brown Immunohistochemical expression of TnC was observed in all groups, where the non-cardiac death, blunt injury and firearm injury groups showed less immunohistochemical staining than stab injury and SCD. The density of the cTnC immunohistochemical staining increased by the increase in the PMI. Quantitative morphometric measurement of cTnC immunohistochemical expression was measured. Significant increases in the mean surface area of cTnC immunohistochemical expression were detected in the groups of only stab injury and SCD compared to the other studied groups (p<0.001), while non-significant differences were detected between non-cardiac, BCI and civilian cardiac firearm injury groups. Besides, the mean surface area of cTnC immunohistochemical expression increased significantly by the increase in the postmortem interval. These findings suggest that the mean surface area of cTnC immunohistochemical expression can differentiate between cardiac and non-cardiac deaths, and between the different types of cardiac deaths.