How acute changes in cardiac troponin concentrations help to handle the challenges posed by troponin elevations in...

Cardiac troponins (cTn) I and T are organ-specific, but not disease specific biomarkers. Although acute myocardial infarction (AMI) is the most important cause of cTn elevation, other cardiac disorders as well as primarily noncardiac disorders with cardiac involvement often are also associated with cardiomyocyte injury. Levels of cTn should be interpreted as quantitative markers of cardiomyocyte injury with the likelihood of AMI increasing with the level of cTn. Similar to the level of cTn at presentation, acute changes in cTn help to differentiate chronic disorders, which show no change, from acute conditions, which usually show a rise from presentation to the second measurement at 1-3h in the emergency department. Thereby, changes in cTn help to overcome some of the challenges posed by cTn elevations in non-AMI patients. Absolute changes in cTn provide a higher diagnostic accuracy for AMI as compared to relative changes. Again, the higher the absolute change, the higher the likelihood for AMI. Two caveats apply to the diagnostic use of cTn changes. First, patients with AMI may show no or only a minimal change when assessed around the peak of cTn release. Second, in addition to AMI, several other acute cardiac conditions including tachyarrhythmias, myocarditis, hypertensive crisis, and Takotsubo cardiomyopathy also may present with substantial cTn changes.