For someone experiencing a heart attack, every second counts. Researchers are currently studying whether tests that detect lower levels of troponin in the blood may help physicians diagnose heart attacks sooner.
What Is Troponin?
Troponin refers to a protein present in the body's heart and skeletal muscle. Two subunits of this protein — cardiac troponin T (cTnT) and cardiac troponin I (cTnI) — are released into the blood when the heart muscle becomes damaged. Since elevated cTnT and cTnI levels can detect injury to the heart, they are the preferred biomarkers to help identify suspected heart attacks.
Measuring Troponin Levels
Troponin levels are measured with a blood test. In healthy individuals, troponin levels are barely detectable. But within six hours of having a heart attack, most people will have increased troponin levels, according to the National Institutes of Health. After 12 hours, almost all heart attack patients will have raised troponin levels.
When someone goes to the hospital with chest pain, the doctor will most likely perform a troponin test to help determine whether he or she has had a heart attack or if the pain is due to something else. While the troponin test is a powerful tool to help doctors diagnose heart attacks, increased troponin levels may also be due to other factors, such as an abnormally fast heartbeat, strenuous exercise or trauma to the heart from a car accident, to name a few.
Promising Research Into Troponin Tests
There is ongoing research into new tests that detect even lower concentrations of troponin in blood. Preliminary results show that the ability to monitor very low levels of the protein may help doctors evaluate whether people are having a heart attack within two to four hours after presenting with symptoms. The hope is that by detecting elevated levels of troponin earlier, doctors may be able to diagnose and treat heart attacks sooner than before.
Sources: National Institutes of Health. Troponin test. http://www.nlm.nih.gov/medlineplus/ency/article/007452.htm. Accessed January 11, 2012; Thygesen, Alpert, Jaffe et al. Third universal definition of myocardial infarction. European Heart Journal, 2012; Anoop, Mills, Griffiths et al. High-sensitivity cardiac troponin and the underdiagnosis of myocardial infarction in women. Study presented at the ESC Congress on September 4, 2013.