Newer cardiac biomarkers in myocardial necrosis.

Sir, M of myocardial necrosis have gone through a long journey since 1950s.The cardiac biomarkers(CB) of past include total creatine kinase (CK) activity, aspartate aminotransferace activity (AST), lactate dehydrogenase (LDH) and LD1/LD2 ratio while the current CB are CK-MB, myoglobin, CKMB isoforms, cardiac troponin (cTn) I and T. The introduction of heart –type fatty–acid binding protein (H-FABP), high sensitive troponin (hs Troponin)and ST2 has led to a better prognosis, early and more precise diagnosis of myocyte injury and apoptosis. High sensitive troponin scores over contemporary cTn assays in detection of cTn in healthy individuals and gives a more precise definition of what is normal (= 99 percentile). These titres can differentiate acute from chronic cardiac myocyte necrosis. cTnT and cTnI levels are not detected in healthy subjects and the 99th percentile is very low (eg-0.04 to 0.5 micrograms/L). Therefore, most assays were imprecise at this low level, so it was recommended to raise the definition of myocardial infarction (MI) at which a specific assay has a coefficient of variat ion of 10% or less . cTnI is less associated with false positives in population with chronic kidney disease (CKD) and therefore is more preferred CB than cTnT in such a clinical setting. The heart type fatty acid binding protein (H-FABP) occurs in nine different isoforms and have a half life of several days. FABPs are transport proteins that carry l ipophil ic molecules l ike eicosanoids and retinoids, fatty acids across the membranes. It is released after myocardial death within 6 hours and is not cardiac specific like myoglobin.1 It can help in much earlier diagnosis as it Newer Cardiac Biomarkers in Myocardial Necrosis