Patients who present in the emergency room with chest pain are given a troponin test (blood sample is taken by nurse).
Troponin is a protein enzyme that leaks from the heart when this muscle is damaged.
If the test result is elevated (in a range that indicates damage to heart tissue), this can mean that the patient had a heart attack very recently.
However, elevated troponin doesn’t always mean cardiac damage.
In fact, the test result isn’t either normal or elevated; there is another range — an in-between range.
It’s sometimes referred to as a gray area or indeterminate area, which (along with elevated status) warrants a follow-up blood draw several hours later to see if the result is of a higher value (meaning that even more troponin has leaked from the heart).
If elevated troponin doesn’t always mean damage to the heart, what else might it mean?
“It can mean a long list of non-cardiac things, the most common being from renal failure, heart failure, pulmonary embolus, cardiac contusion, sepsis, cardiotoxins, CNS disorders, excessive exercise,” says Dr. Sameer Sayeed, a cardiologist at ColumbiaDoctors of Somers, NY.
Generally, with modern assays and automated laboratory systems, troponin results can be returned within a few hours, often between one to three hours after the sample is taken.
Some rapid tests and point-of-care systems can provide results in as little as 20 to 60 minutes.
Other causes of elevated troponin not related to the heart muscle include: high blood pressure, drug toxicity, low thyroid, transient ischemic attack, stroke and rheumatoid arthritis.