This patient should receive high-dose aspirin. He has acute pericarditis in the setting of a recent myocardial infarction. The typical chest pain, physical examination findings, and abnormal electrocardiogram (ECG) are all consistent with this diagnosis, especially the findings of concave upward ST-segment elevation and PR-segment depression in all leads, except aVR, on the ECG. Anti-inflammatory therapy with aspirin or other NSAIDs, such as ibuprofen, is indicated in patients with acute pericarditis. In those whose pericarditis is associated with myocardial infarction, such as this patient, only aspirin should be used because ibuprofen and other NSAIDs can impair myocardial healing and increase the risk of mechanical complications. The anti-inflammatory medication should be given in relatively high doses to achieve an anti-inflammatory effect and then tapered slowly over 2 to 4 weeks to reduce the risk of recurrent pericarditis. Colchicine (0.5-1.2 mg/d) also has been shown to be effective as adjunctive therapy to anti-inflammatory agents in patients with acute pericarditis, further reducing the risk of recurrent pericarditis and treatment failure. Colchicine is not recommended for patients with post-infarction pericarditis. Colchicine may be associated with gastrointestinal side effects, liver toxicity, and bone marrow suppression but is generally well tolerated.

Nitroglycerin is an effective therapy for chest pain caused by myocardial ischemia but is not effective for symptoms caused by pericarditis.

Glucocorticoids, such as prednisone, are reserved for patients with contraindications to NSAIDs or those with refractory acute pericarditis, primarily because there is evidence that their use is associated with an increased risk of recurrent pericarditis. As this patient has no apparent contraindication to aspirin use, treatment with glucocorticoids is not indicated.