Evaluation of the role of some biochemical markers in the diagnosis of acute mycoardial infarction an antemortem and postmortem study

ABSTRACT

Cardiac disease is the most frequent cause of sudden death. Moreover, the beginning of myocardial damage does not necessarily conincide with the appearance of symptoms, and therefore an asymptomatic period may ensue. One of the most difficult problems that face the critical care clinicians and forensic pathologists is to diganose sudden death in subjects with acute cardiac processes that progressed rapidly, with non-specific symptoms in many cases, and led to death without obvious morphological alterations. In recent years, many researches has been done to look for rapid, sensitive and specific cardiac markers that can assist critical care clinicians and forensic pathologists to make an early diangosis of acute myocardial infarction [AMI]. The latest markers available in market include troponins [I and T], creatine kinase [CK] and myoglobin. Cardiac troponin I [cTnI] is eventually a more sensitive, and a more reliable serum marker than cardiac troponin [cTnT] for the determination of damaged cardiac tissue following AMI. The aim of the present work is to test the prognositc value and reliability of measuring levels of certain blood biochemical markers for diangosing death due to acute myocardial infarction. The study was conducted at the Critical Care Department Units of Alexandria Main University Hospital. It was carried out on 62 selected cases suffering from extensive acute myocardial infarction. A spectal sheet was designed to collect the required information. Follow up of the patients was carried out till either improvement or death. Blood was obtained from all patient for cardiac markers assays on admission, six hours after admission, and two hours postmortem for those who died [femoral vein]. Serum samples were tested for Cardiac troponin I [cTnI], Myoglobin and Creatine kinase MB [CK-MB]. Aditional 10 control deaths were included in the study [non-AMI deaths]. The results of the present study revealed that statistically significant differences were obtained for cTnI, myoglobin and CK-MB between Survived-MI cases and Non-Survived ones on admission and 6 hours later. Similarly, the concentrations of the three studied biochemical parameters in myocardial infarction [MI] patients, 6 hours from admission and 2 hours after death showed statistically significnat differences. Furthermore, the study showed postmortem significantly higher serum levels of these cardiac markers in deaths due to AMI as compared to deaths due to Non-MI. When comparing the cut off values of the 3 cardiac markers, it was found that measuring cTn I and CK-MB provide prognositc information that permits the early identification of patients with AMI at increased risk of death, hence aggressive treatement is needed for them and claims of malpractice are ruled out