The cardiac isoforms of Troponins I or T are the preferred markers for the diagnosis of myocardial injury. They are more sensitive and specific than than CK-MB or other conventional markers.
Troponins are present in complexes of similar weight to CK-MB and it is likely that they are released from injured cells at similar rates. Once elevated troponins may persist for a number of weeks and in some circumstances CK-MB may be useful in clarifying whether an event is recent (within 48 hours).
The ideal time to check for cardiac troponins is between 6 and 9 hours. Ideally one should also document an elevation in more than one sample
High sensitivity cardiac troponins (hs-cTnTs) can be taken earlier to determine if an acute myocardial infarction has occurred
Last reviewed 02/2021