Plasma cardiac troponin T closely correlates with infarct size in a mouse model of acute myocardial infarction

Background: Cardiac troponins replaced creatine kinase and lactate dehydrogenase isoenzymes as criterion standards for the laboratory diagnosis of myocardial damage. However, there are only few publications on correlations of cardiac troponin T (cTnT) with pathologically determined infarct size which are flawed by insufficient sample size. Methods: In 38 anesthetized wildtype mice, the chest and pericardium were opened and the left descending artery was ligated. After sham operation, all mice recovered. Twenty-four hours after surgical induction of acute myocardial infarction heparinized blood samples were collected, the animals sacrificed and hearts harvested. Plasma cTnT was measured by a quantitative rapid assay using the Cardiac Reader (Roche Diagnostics). The hearts were cut into four transverse sections which were stained with 1.5% triphenyltetrazolium chloride for evaluation of necrosis by computerized planimetry. Pearson correlation coefficients were calculated between histological infarct size and cardiac markers. Results: Infarct sizes ranged from 14% to 55% of left ventricle and cTnT concentrations from 3.9 to 14.1 mug/l. cTnT correlated closely with histological infarct size (r=0.84, p<0.001). Conclusions: This study for the first time demonstrates a close correlation of cTnT release with pathological infarct size in a suitable experimental model with a sufficient sample size. (C) 2002 Elsevier Science B.V. All rights reserved.