In non-ST-segment elevation myocardial infarction, risk stratification is based on the patient’s medical history, clinical presentation, pain characteristics, ECG, and cardiac markers.1 Patients in high risk stratification have characteristics: they may have ischemic symptoms that worsen or exacerbate within 48 hours. It is also possible that patients may present with prolonged symptoms of precordial pain and have resting chest pain as the main manifestation, often greater than 20 minutes. Other patients may develop pulmonary edema, or a new murmur of mitral valve insufficiency. Others may develop hypotension, bradycardia, and the ECG may show transient ST-segment changes or new bundle-branch conduction block. Patients at high risk may also have elevated cardiac markers.2 Patients at moderate risk are those with a previous history of heart attack or cerebrovascular disease. The pain is predominantly resting pain and can last longer than 20 minutes. Some patients have resting chest pain for less than 20 minutes or can be relieved with rest or sublingual nitroglycerin. The ECG may show inversion of T waves or may show pathological Q waves, and cardiac markers may be mildly elevated.3. In patients with mildly dangerous non-ST-segment elevation myocardial infarction, the ECG often shows no changes during chest pain or is only normal. Their pain is characterized by new onset of Canadian Cardiovascular Society graded grade III or IV angina within the past two weeks, but no prolonged episodes of resting chest pain.