Cardiac troponin biomarkers

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

• there is evidence that using hs-cTnT determination, it was possible to diagnose an acute myocardial infarction in 94% of cases at admission and in 100% of the cases, if the assay was repeated at 3 h.

Reference:

• 1) Aldous SJ et al. Diagnostic and prognostic utility of early measurement with high-sensitivity troponin T assay in patients presenting with chest pain.CMAJ. 2012 Mar 20;184(5):E260-8
• 2) Stabile E, Agresta A. High-sensitivity troponin useful for diagnosis and prognosis in patients with acute coronary syndrome. Evid Based Med. 2013 Feb;18(1):42.