Analytical characteristics of commercial cardiac troponin I and T immunoassays in serum from rats, dogs, and monkeys with induced acute myocardial injury

A translational approach to detecting drug-induced cardiac injury with cardiac troponins: consensus and recommendations from the Cardiac Troponins Biomarker Working Group of the Health and Environmental Sciences Institute

Cardiac troponins (cTns) are established biomarkers of ischemic heart disease in humans. However, their value as biomarkers of cardiac injury from causes other than ischemic heart disease is now being explored, particularly in drug development. In a workshop sponsored by the Cardiac Troponin Biomarker Working Group of the Health and Environmental Sciences Institute, preclinical, clinical, and regulatory scientists discussed the application of cTns in their respective environments, issues in translating the preclinical application of cTn to clinical studies, and gaps in our understanding of cTn biology and pathobiology. Evidence indicates that cTns are sensitive and specific biomarkers of cardiac injury from varying causes in both animals and humans. Accordingly, monitoring cTns can help ensure patient safety during the clinical evaluation of new drugs. In addition, preclinical characterization of cardiac risk and cTns as biomarkers of that risk can guide relevant clinical application and interpretation. We summarize here the outcomes of the workshop which included consensus statements, recommendations for further research, and a proposal for a cross-disciplinary group of clinical, regulatory, and drug development scientists to collaborate in such research.

Qualification of cardiac troponin I concentration in mouse serum using isoproterenol and implementation in pharmacology studies to accelerate drug development

Cardiac troponin I is a useful biomarker of myocardial injury, but its use in mice and application to early drug discovery are not well described. The authors investigated the relationship between cTnI concentration in serum and histologic lesions in heart tissue from mice treated with isoproterenol (ISO). Cardiac TnI concentrations in serum increased in a dose-dependant manner and remained increased twenty-four to forty-eight hours after a single administration of isoproterenol. Increased cTnI concentration was of greater magnitude and longer duration than increased fatty acid binding protein 3 concentration, aspartate aminotransferase activity, and creatine kinase activity in serum. Isoproterenol-induced increases in cTnI concentrations were both greater and more sustained in BALB/c than in CD1 mice and correlated with incidence and severity of lesions observed in heart sections from both strains. In drug development studies in BALB/c mice with novel kinase inhibitors, cTnI concentration was a reliable stand-alone biomarker of cardiac injury and was used in combination with measurements of in vivo target inhibition to demonstrate an off-target contribution to cardiotoxicity. Additional attributes, including low cost and rapid turnaround time, made cTnI concentration in serum invaluable for detecting cardiotoxicity, exploring structure-activity relationships, and prioritizing development of compounds with improved safety profiles early in drug discovery.