Cardiac biomarkers in blood, and pericardial and cerebrospinal fluids of forensic autopsy cases: A reassessment with special regard to postmortem interval

• Previous studies on postmortem cardiac biomarkers described inconsistent results.
• This study comprehensively reviewed autopsy data with regard to cause of death.
• Cardiac biomarker levels depended on the causes of death and postmortem time.
• Elevated cardiac biomarker levels were not specific for myocardial infarction.
• Other causes of elevated cardiac biomarkers were similar to clinical findings.

Previous studies suggested possible application of postmortem biochemistry of myocardial biomarkers to the investigation of sudden cardiac death; however, differences from clinical findings should be considered in autopsy materials. The present study involved a comprehensive investigation of cardiac troponin T and I (cTnT and cTnI), and creatine kinase MB (CK-MB) in cardiac and peripheral external iliac venous blood, pericardial fluid (PCF) and cerebrospinal fluid (CSF) for reassessment, with special regard to the estimated postmortem interval in relation to the cause of death, reviewing a large number of forensic autopsy cases (n = 1923). These cardiac biomarkers showed cause-of-death- and postmortem-time-dependent differences: blood and PCF levels of each marker were higher in hyperthermia (heatstroke), bathwater drowning and chronic congestive heart disease in cases of postmortem interval (PMI) <12 h. After 12 h postmortem, these markers were also higher in fatal drug abuse, spontaneous cerebral/subarachnoid bleeding, electrocution and pulmonary embolism. In addition, most other causes of death, including ischemic heart disease, showed substantial elevations, while these markers remained low in acute hemorrhagic death from sharp instrument injury, hypothermia (cold exposure) and sea-/freshwater drowning during PMI of <48 h. CSF cTnI and CK-MB showed similar findings. There was no difference between myocardial infarction and other causes of death to be discriminated, including asphyxiation, drowning and fire fatality. These findings are similar to clinical observations in critical ill patients, suggesting that elevated cardiac biomarkers cannot be a specific finding for death from acute ischemic heart disease, but indicate the severity of myocardial injury in postmortem investigation.