Cardiac troponin T as a postmortem biomarker for acute myocardial infarction

The diagnosis of acute myocardial infarction (AMI), especially within the first hours after onset of ischemia, poses a challenge to the forensic pathologist. During this time, the infarction is generally not visible macroscopically nor with routine histology. Whilst cardiac Troponin T (cTnT) is a well-established biomarker for AMI clinically, its use as a postmortem diagnostic tool is less conclusive, warranting further investigation. The aim of this study was to investigate the sensitivity and specificity of cTnT as a postmortem diagnostic marker of AMI and the impact of postmortem interval (PMI) and cardiopulmonary resuscitation (CPR) on cTnT-concentrations. Samples from 64 subjects, 15 AMI cases and 49 controls, were collected at the Department of Forensic Medicine in Stockholm and analyzed for cTnT: one femoral blood sample was taken at arrival of the body to the morgue, and again during autopsy. Pericardial fluid (PCF) was only collected during autopsy. Sensitivity and specificity for serum cTnT were calculated to be 86.7 %/67.3 % and for pericardial fluid 86.7 %/44.9 %. cTnT samples taken during autopsy were generally higher than samples taken upon arrival to the morgue. A CPR-dependent elevation in serum cTnT was noted (P = .005). With a cut off at 56 n/L, serum cTnT can be used to rule out AMI. The postmortem interval and CPR must be taken into consideration when interpreting postmortem cTnT.