Acute coronary syndromes (ACS), including non-ST-segment elevation (NSTE) ACS, represent a significant source of morbidity and mortality in the United States. To address this widespread, serious health problem, the American College of Cardiology and the American Heart Association (ACC/AHA) published guidelines for the treatment of NSTE ACS, which include unstable angina (UA) and NSTE myocardial infarction (NSTEMI). These ACC/AHA guidelines are intended to help physicians make appropriate decisions when diagnosing and treating patients with NSTE ACS.