Abstract 16716: Comparison of Blood Troponin I Complexes and Free Form in Acute Myocardial Infarction and End Stage Renal Disease
Introduction: Circulating blood troponin complexes and free fractions remain poorly characterised in different conditions where troponin is detectable in blood Hypothesis: The aim of the study was to compare the differences in troponin-I(TnI) complexes/free-forms in end stage renal disease (ESRD) compared to acute myocardial infarction(AMI) Methods: Blood was collected from patients with AMI(n=7) or ESRD(n=4) at two time points (a)As early as possible after AMI or at initial contact with ESRD patients and (b)24-48 hours later. Western blotting was carried out with HyTest cTnI-560cc antibody on plasma extracted from whole blood. Densitometry analysis was performed and evaluated using the independent samples T-test and paired T-test as appropriate Results: Prominent bands were noted at ~45,~37 and ~25 kDa respectively representing low molecular weight(LMW) TnI-TnT-TnC complex, binary TnI-TnC complex and free-TnI. At time-point (a), there was no difference in these bands between STEMI and CKD patients. Interestingly, at time-point (b), AMI patients had significantly lower intensity of the 45kDa and 37kDa bands compared to CKD patients(for 45 kDa band mean difference was 54.3±19.4 AU, p=0.02; for 37 kDa band mean difference was 27.7±10.5 AU, p=0.03) as well as compared to the initial STEMI samples taken at time-point (a)(for 45 kDa band mean difference was 41.4±8.1 AU, p=0.002; for 37 kDa band mean difference was 16.7±6.3 AU, p=0.002) ,however there was no difference in the 25kDa band Conclusions: AMI patients had progressively lesser quantities of circulating LMW-ITC and binary IC complexes following AMI compared to ESRD patients, but similar quantities of circulating free TnI. This indicates a constant release of LMW-ITC and binary-IC complexes from the myocardium or reduced glomerular filtration of these complexes in ESRD while in the AMI patients, the LMW-ITC and binary I-C complexes appear to be progressively eliminated from plasma after the initial release