This patient should be given a P2Y₁₂ inhibitor, such as clopidogrel, and an anticoagulant, such as the low-molecular-weight heparin enoxaparin, and be admitted to the hospital. Once the diagnosis of a non–ST-elevation myocardial infarction (NSTEMI) has been confirmed by the presence of ischemic chest pain, ST-segment depression on the electrocardiogram (ECG), and/or abnormal cardiac biomarkers, the use of antiplatelet and anticoagulant medications, antianginal medications, and cardioprotective medications is imperative. This patient was given aspirin and nitroglycerin prior to the diagnosis of NSTEMI, and he takes daily ACE inhibitor and statin medications. The additional therapies that are warranted in this situation include a P2Y₁₂ inhibitor (clopidogrel, prasugrel, ticagrelor), an anticoagulant (unfractionated heparin or low-molecular-weight heparin), and a β-blocker. The use of clopidogrel, in addition to aspirin, is the best-studied combination of antiplatelet medications.

In patients with an ST-elevation myocardial infarction (STEMI), reperfusion, preferably via percutaneous coronary intervention, should be performed as quickly as possible from symptom onset. This patient does not have evidence of ST-segment elevation or left bundle branch block on the initial ECG. Although an early invasive strategy (defined as within 24 hours of hospital admission) has been proved to be effective in treatment of NSTEMI, there is no evidence that earlier angiography (<6 hours or at hospital admission) offers incremental benefit to these patients.

In patients with a low TIMI risk score (0-2), indicating a low in-hospital risk of death or recurrent ischemia/infarction, predischarge stress testing may be warranted to further define a large ischemic burden and guide revascularization decisions. This patient has a TIMI risk score of 4 (≥3 traditional cardiovascular risk factors, ST-segment deviation, daily aspirin use, elevated cardiac biomarkers), placing him at intermediate risk. These patients have improved clinical outcomes with an early invasive strategy. Exercise stress testing is not appropriate and may be dangerous.

Clinical decision-making should not be affected by the results of the second set of cardiac biomarkers. The presence of an elevated troponin level drawn in the emergency department is prognostically significant and warrants hospital admission, treatment of NSTEMI, and risk stratification.