What is the most effective therapy for a 65-year-old patient with low-grade fever and pleuritic chest pain two weeks after myocardial infarction (heart attack)?

Management of Post-MI Pericarditis

An anti-inflammatory agent is the most effective therapy for a 65-year-old patient presenting with low-grade fever and pleuritic chest pain two weeks after myocardial infarction. 1, 2

Clinical Presentation Analysis

The patient's presentation strongly suggests post-MI pericarditis based on:

• Timing: Two weeks after documented MI
• Symptoms: Low-grade fever and pleuritic chest pain
• Absence of shortness of breath
• Normal lung and heart examination
• Unchanged ECG from hospital discharge

This clinical picture is consistent with post-MI pericarditis (Dressler syndrome), which typically presents 1-3 weeks after a myocardial infarction with pleuritic chest pain and low-grade fever.

Diagnostic Differentiation

It's important to differentiate post-MI pericarditis from other potential causes:

• Post-MI pericarditis: Pleuritic chest pain, low-grade fever, normal lung exam, unchanged ECG
• Recurrent ischemia: Usually associated with similar pain to original MI, new ECG changes, often with shortness of breath
• Infection: Would typically present with higher fever, abnormal lung exam, leukocytosis
• Pulmonary embolism: Usually presents with shortness of breath, which is absent here

Treatment Approach

First-line Treatment

• High-dose aspirin (650 mg every 4-6 hours) is the cornerstone therapy for post-MI pericarditis 1
• Continue until symptoms resolve, then taper gradually

Additional Options

• Colchicine (0.6 mg every 12 hours orally) can be added if symptoms are not adequately controlled with aspirin alone 1, 2
• Acetaminophen (500 mg orally every 6 hours) may be used for additional pain relief 1

Treatments to Avoid

• Glucocorticoids should be avoided as they increase the risk of myocardial scar thinning and rupture 1
• NSAIDs (except aspirin) should be avoided due to their continuous effect on platelet function and increased risk of myocardial scar thinning and infarct expansion 1
• Anticoagulation is not indicated for uncomplicated post-MI pericarditis and may increase risk of hemorrhagic conversion 1
• Antibiotics are not indicated as this is an inflammatory, not infectious process
• Antianxiety agents do not address the underlying pathology
• Antianginal medications would not be effective as this is not an ischemic process

Monitoring and Follow-up

• Monitor for symptom resolution with anti-inflammatory therapy
• Perform serial ECGs to evaluate for any evolution of changes
• Consider echocardiography if symptoms worsen to evaluate for pericardial effusion
• Watch for rare complications such as cardiac tamponade or constrictive pericarditis

Pitfalls and Caveats

• Don't mistake post-MI pericarditis for recurrent ischemia; the pleuritic nature of the pain, absence of new ECG changes, and timing post-MI are key differentiating factors
• Avoid corticosteroids even if symptoms are severe, as they increase risk of myocardial rupture
• Remember that post-MI pericarditis is associated with larger infarcts, so these patients may have higher long-term mortality despite the typically benign course of the pericarditis itself 3

By correctly identifying this presentation as post-MI pericarditis and treating with appropriate anti-inflammatory therapy, you can effectively manage the patient's symptoms while avoiding potentially harmful treatments.