Troponin-I
Definition
Troponin is a protein found in heart muscle cells. When heart tissue is damaged it leaks into the blood and can be detected with a blood test.
Purpose
Used mainly in the diagnosis of heart attack (myocardial infarction). It confirms heart muscle damage and, according to the degree of elevation, gives an idea of the extent of the damage. In the emergency department it is performed together with the ECG and other cardiac assessments.
Results
Timing is critical:
| Situation | Interpretation |
|---|---|
| First result normal | Repeated within 12 hours; the rise in troponin becomes visible about 2 to 3 hours after the heart attack begins |
| Still normal at 12 hours | Heart attack is unlikely |
| High | Heart muscle damage is present; very high levels suggest acute MI |
| Continuing to rise | Levels may continue to rise for about 24 hours after the infarction |
Normal Values
Laboratory specific.
Risks and Limitations
High troponin has many causes other than heart attack: arrhythmias, heart failure, myocarditis, heart surgery, intense exercise, chest trauma, kidney disease, pulmonary embolism, sepsis and severe COVID-19.
For this reason, a high troponin on its own does not mean "you have had a heart attack"; it is evaluated together with the clinical picture, ECG and serial measurements.