Cardiac markers protocols in a chest pain observation unit

The use of cardiac markers to identify high-risk patients in the observation unit (OU) of an emergency department (ED) is indispensable. As the literature reviewed in this article reveals, the use of patient history and ECG alone overlooks a significant portion of patients with acute cardiac ischemia. it is believed that acute myocardial infarction and some high-risk unstable angina OU patients can be identified within 6 hours of hospital presentation using a combination of cardiac markers. Testing soon after symptom onset, or on arrival in the ED, with myoglobin, CK-MB subforms, or CK-MB delta, appear to provide the best diagnostic usefulness. For testing later in the clinical course, CK-MB, troponin I, or troponin T are of clear diagnostic and prognostic value. The markers currently used, however, are unable to identify a significant subset of patients with non-AMI coronary syndromes. These patients require further testing with appropriate noninvasive or invasive diagnostic studies.