Common scenarios to clarify the interpretation of cardiac markers

Abstract

The authors present a practical approach for physicians in clinical practice to use cardiac troponins in the interpretation of heart disease and myocardial damage. Laboratory results that fall within the intermediate area of facility-specific cutoff reference values for elevated troponin levels confer lower risks to patients than do higher levels of cardiac troponin. Perhaps not surprisingly, the actual anatomy of the vessels at cardiac catheterization does not correlate well with the troponin level. In the six cases presented here, the patients' low levels of troponin release are discussed using the new term minimal myocardial infarction, which is synonymous with conditions that would previously have been diagnosed as unstable angina. Elevated levels of cardiac troponin provide a very sensitive measure for clinicians diagnosing patients with myocardial necrosis, but such measures are also useful in defining a broad spectrum of disease. Whenever the troponin levels are elevated (barring laboratory error), the patient has a poorer prognosis. The greatest challenge for physicians is in determining which patients with cardiac troponin elevation will best benefit from heart catheterization and percutaneous intervention.