Markers of acute coronary syndrome in emergency room.

Acute coronary syndromes (ACS) encompasses a spectrum of coronary heart diseases, ranging in severity from unstable angina to ST-elevation myocardial infarction (STEMI). Early diagnosis and risk stratification are needed in order to address correctly hospitalization and treatment. Although the diagnosis of STEMI in the presence of typical electrocardiogram (ECG) changes and symptoms is easy and does not require the use of biomarkers, cardiac biomarkers are particularly important in the Emergency Department (ED), where about 25% of patients admitted are affected by ACS but clinical presentation is often atypical and ECG alterations may be absent. The ideal marker in the ED should have rapid release, high sensitivity and specificity and risk stratifying properties. Classic cardiac biomarkers, like myoglobin, cardiac troponin T or I and creatine kinase-MB, have a poor sensitivity, dependent on the time past from the onset of symptoms to presentation, the duration of ischemia and the amount of myocardial tissue involved. Although the serial testing of these cardiac biomarkers can improve the detection of myocardial necrosis, there is still a need for the development of early markers that can reliably rule out ACS from the ED at presentation and also detect myocardial ischemia in the absence of irreversible myocyte injury. There are several markers which represent the different features of ACS pathogenesis and that can be divided into three major groups: markers of cardiac ischemia and necrosis, markers of inflammation and coronary plaque instability and marker of cardiac function.