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.