Physical Examination e352 3.2.3. Electrocardiogram e353 Biomarkers of Myocardial Necrosis e353 3.2.5. Imaging e353 Prognosis Early Risk Stratification: Recommendations e353 Rationale for Risk Stratification and Spectrum of Risk: High, Intermediate, and Low e354 3.3.2. Estimation of Level of Risk e354 3.3.2.1. History: Angina Symptoms and Angina Equivalents e354 Demographics and History in Diagnosis and Risk Stratification e354 Early Estimation of Risk e355 3.3.2.4. Electrocardiogram e355 3.3.2.5. Physical Examination e357 Cardiac Biomarkers and the Universal Definition of MI: Recommendations e357 3.4.1. Biomarkers: Diagnosis e357 3.4.2. Biomarkers: Prognosis e357 3.4.3. Cardiac Troponins e357 3.4.3.1. Prognosis e358 CK-MB and Myoglobin Compared With Troponin e359 3.5. Immediate Management e359 Discharge From the ED or Chest Pain Unit: Recommendations e359 4. Early Hospital Care e359 4.1. Standard Medical Therapies e360 4.1.1. Oxygen: Recommendation e360 4.1.2. Anti-Ischemic and Analgesic Medications e360 4.1.2.1. Nitrates: Recommendations e360 4.1.2.2. Analgesic Therapy: Recommendations e361 4.1.2.3. Beta-Adrenergic Blockers: Recommendations e362 Calcium Channel Blockers: Recommendations e362 4.1.2.5. Other Anti-Ischemic Interventions e363 4.1.2.6. Cholesterol Management e363 Inhibitors of the Renin-Angiotensin-Aldosterone System: Recommendations e363 4.3. Initial Antiplatelet/Anticoagulant Therapy in Patients With Definite or Likely NSTE-ACS e364 Initial Oral and Intravenous Antiplatelet Therapy in Patients With Definite or Likely NSTE-ACS Treated With an Initial Invasive or Ischemia-Guided Strategy: Recommendations e364 4.3.1.1. Aspirin e365 Receptor Inhibitors e365 4.3.2. Initial Parenteral Anticoagulant Therapy in Patients With Definite NSTE-ACS: Recommendations e367 Heparin e367 4.3.2.2. Bivalirudin e367 4.3.2.3. Fondaparinux e367 4.3.2.4. Unfractionated Heparin e367 4.3.2.5. Argatroban e368 Fibrinolytic Therapy in Patients With Definite NSTE-ACS: Recommendation . e368 Ischemia-Guided Strategy Versus Early Invasive Strategies e368 4.4.1. 