What is the treatment for pericarditis post myocardial infarction (MI) or stent placement syndrome?

Treatment of Post-MI Pericarditis and Post-Stent Placement Syndrome

For early post-MI pericarditis (occurring 1-3 days after MI), start with acetaminophen for symptomatic relief; if symptoms persist or for late pericarditis (Dressler's syndrome), escalate to high-dose aspirin (500-1,000 mg every 6-8 hours) plus colchicine (0.5-0.6 mg once or twice daily for 3 months). 1

Initial Conservative Management

Early pericarditis (1-3 days post-MI):

• Most cases are transient and resolve with conservative therapy alone 1
• Acetaminophen 500 mg every 6 hours is the first-line agent for symptomatic relief 1
• This approach avoids bleeding risks in patients on dual antiplatelet therapy (DAPT) after stenting 2

Escalation for Persistent or Late Pericarditis

When symptoms persist despite acetaminophen OR for Dressler's syndrome (weeks after MI):

• High-dose aspirin: 500-1,000 mg every 6-8 hours until symptoms improve 1, 3, 4
• Add colchicine: 0.5-0.6 mg twice daily (if ≥70 kg) or once daily (if <70 kg) for 3 months 1, 3
• Colchicine reduces recurrence rates by approximately 50% 3
• Adjust colchicine dosing in stage 4-5 kidney disease, severe hepatic impairment, or with P-glycoprotein/CYP3A4 inhibitors 1

Critical Medications to Avoid

Glucocorticoids and NSAIDs (other than aspirin) are potentially harmful due to:

• Increased risk of recurrent MI 1
• Impaired myocardial healing and risk of ventricular rupture 1, 4
• Myocardial scar thinning and infarct expansion 1
• These agents carry a Class III: Harm recommendation 1, 4

Special Considerations for Post-Stent Patients

In patients recently stented who are on DAPT plus anticoagulation:

• High-dose aspirin may increase bleeding risk 2
• Colchicine plus acetaminophen is a reasonable alternative to avoid aspirin dose escalation 2
• This combination successfully treats symptoms while maintaining standard DAPT dosing 2

Diagnostic Criteria

Diagnosis requires pleuritic chest pain PLUS ≥1 of the following: 1

• Pericardial friction rub on auscultation
• ECG changes: PR-segment depression, diffuse concave ST-elevations, or persistent ST-elevations/dynamic T-wave changes post-MI
• New or growing pericardial effusion on echocardiography

Important Clinical Pitfalls

Do NOT routinely treat asymptomatic pericardial effusions with high-dose aspirin or colchicine 1

Monitor for cardiac tamponade in patients with effusions >10 mm, which requires investigation for possible subacute rupture and hospitalization 3

Inadequate treatment of the first episode is the most common cause of recurrence—ensure full treatment duration 4

Taper medications gradually: Decrease aspirin by 250-500 mg every 1-2 weeks, taper one drug at a time before discontinuing colchicine 3

Refractory Cases

For symptoms unresponsive to aspirin plus colchicine:

• Consider long-term oral corticosteroids (3-6 months) as a last resort 1, 3
• Pericardiocentesis with intrapericardial triamcinolone (300 mg/m²) may be considered 3
• Use corticosteroids with extreme caution due to harm risks outlined above 1