What are troponin levels? What role do they play in the heart?

In the last several decades, just as we have seen the development of new, highly effective treatments to counter cardiovascular disease, we have also seen the development of new tests that facilitate doctors' abilities to rapidly and accurately diagnose serious forms of heart disease. One of the best examples of the latter is in the assessment of cardiac "troponins." Since their discovery in 1989, "troponin levels" have helped to redefine the ways doctors determine whether a person is having or has had a heart attack.

Cardiac troponins are a group of proteins found specifically in the muscles cells of the heart that help the heart coordinate its muscular activity. Research performed largely within the last 10 years has demonstrated that normal people do not have any measurable amounts of these proteins circulating in their bloodstreams.

Individuals with various forms of heart muscle injury (most notably from a heart attack), however, do have circulating levels of these proteins. In fact, within approximately 4 hours of damage to heart muscle, troponin blood levels detected by a simple blood test begin to rise. These levels can remain elevated for up to 10 to 14 days after the initial onset of heart muscle damage. Troponins also rise in proportion to the amount of heart muscle injury.

Thus, troponins have emerged as one of the simplest and most effective ways for cardiologists to estimate the severity of a person's heart attack, which in turn, is critical for deciding upon the best forms of heart attack therapy. Troponins add important prognostic information as well. Understanding a patient's future risk for developing recurrent heart attacks or heart failure helps to optimize long-term cardiovascular prevention strategies.