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).

Troponin levels begin to rise within 3 to 4 hours after symptom onset, peak at 24 to 48 hours, and may remain elevated for 7 to 14 days (cardiac troponin T up to 14 days; cardiac troponin I often 7 to 10 days).

High sensitivity cardiac troponins (hs-cTnTs) measurement is recommended in all patients with suspected ACS. If the clinical presentation is compatible with myocardial ischaemia, then a rise and/or fall above the 99th percentile of healthy individuals points to a diagnosis of MI.

Reference:

1. NICE. Acute coronary syndromes. NICE guideline NG185. Published November 2020
2. NICE. High-sensitivity troponin tests for the early rule out of NSTEMI. HealthTech guidance HTG552. Published August 2020