Distribution & diagnostic efficacy of cardiac markers CK-MB & LDH in pericardial fluid for postmortem diagnosis of ischemic heart disease.

The aim of the present study is to evaluate the diagnostic efficacy of biochemical markers creatine kinase-MB (CK-MB) and LDH in pericardial fluid for postmortem diagnosis of ischemic heart disease (IHD). We studied 119 medico-legal autopsies selected during a period of 2 years. Subjects were assigned into diagnostic groups upon final cause of death as follows: (1) sudden cardiac death due to IHD's (n = 52), (2) violent asphyxia (n = 24); (3) polytraumatic deaths (n = 20); (4) natural deaths excluding cardiac causes (n = 23). Pericardial fluid samples were tested for estimating enzyme levels. Histological examination was performed with hematoxylin and eosin (H&E) stain on myocardial tissue samples. We observed highest levels of CK-MB & LDH in deaths due to IHD's. Kruskal-Wallis test revels significant differences in activities of CK-MB (P = 0.0001) and LDH (P = 0.0065) amongst all diagnostic groups. Mann-Whitney test showed highly significant (P < 0.0001) levels of CK-MB in group 1 as compared to other diagnostic groups. However, LDH levels were non-discriminatory (P = 0.0827) between cases of IHD's and cases of other natural deaths. CK-MB levels were statistically non-significant between cases divided as myocardial infarction (MI) and severe coronary artery disease in group 1, hence its role for postmortem detection of MI is somewhat limiting. However, sensitivity and negative predictive values of its cut off level obtained in cases of IHD's are nearly equal to diagnostic efficacy in clinical settings. Hence, it can be useful additional diagnostic tool for autopsy diagnosis of IHD's. Whereas, LDH is not useful for postmortem diagnosis in these cases.