Cardiac markers for assessing the acute coronary syndromes - A focus on cardiac troponins

Markers of myocardial injury will continue to play an essential role in the assessment and management of patients presenting within the spectrum of ac ute coronary syndromes, a term representing the continuum of acute myocardi al ischemia ranging from angina through Q-wave myocardial infarction. Coron ary artery lesion instability can be detected by markers of plaque inflamma tion and disruption, platelets reactivity, and thrombosis. When myocardial injury occurs with severe impairment of coronary blood flow, several marker s are released from the damaged myocyte. For many years, creatine kinase-MB isoenzyme has been the conventional marker for myocardial infarction. Desp ite its inadequate sensitivity and specificity for myocardial injury, creat ine kinase-MB remains an essential component in assessing reinfarction or i nfarct extension, as well as in monitoring reperfusion after thrombolytic t herapy when combined with myoglobin. Among the many cardiac markers for myo cardial necrosis, cardiac troponins possess superior sensitivity and specif icity for the detection of myocardial injury. In addition to their superior performance in detecting minor myocardial damage, cardiac troponins can be useful in detecting perioperative myocardial infarction, infarct size, imp roving risk stratification, and facilitating therapeutic decision making in patients with acute coronary syndromes.