What are the indications for managing pericarditis after left heart catheterization (LHC)?

Management of Pericarditis After Left Heart Catheterization

Pericarditis after left heart catheterization (LHC) should be managed with high-dose aspirin (500-1000 mg every 6-8 hours) as first-line therapy, with the addition of colchicine (0.5-0.6 mg once or twice daily for 3 months) to reduce symptoms and prevent recurrence. 1

Diagnosis of Post-LHC Pericarditis

Diagnosis requires at least 2 of the following 4 criteria:

• Pericarditic chest pain (typically pleuritic, positional)
• Pericardial friction rub on auscultation
• ECG changes (PR depression, diffuse ST-segment elevation)
• New or worsening pericardial effusion 1

Additional supporting findings include:

• Elevated inflammatory markers (CRP, ESR, WBC)
• Evidence of pericardial inflammation on imaging (CT, CMR) 1

Etiology and Classification

Post-LHC pericarditis is classified as a post-cardiac injury syndrome (PCIS), specifically an iatrogenic form of pericarditis that occurs after cardiac procedures. It may present as:

1. Early pericarditis: Occurs 1-3 days after LHC due to direct inflammatory response to adjacent tissue injury
2. Late pericarditis (Dressler's syndrome): Occurs weeks after LHC, believed to be immune-mediated 1

Treatment Algorithm

First-Line Therapy

1. High-dose aspirin: 500-1000 mg every 6-8 hours until symptoms improve 1

   • Preferred over other NSAIDs due to favorable coronary flow effects
   • Continue until symptoms resolve and inflammatory markers normalize

2. Colchicine: Add to aspirin therapy 1

   • Dosing: 0.5-0.6 mg once daily (if <70kg) or twice daily (if ≥70kg)
   • Duration: 3 months
   • Reduces symptoms and decreases risk of recurrence

3. Acetaminophen: Can be used for symptomatic relief in early pericarditis 1

Important Considerations

• Avoid other NSAIDs (except aspirin) as they may impair myocardial healing and increase risk of rupture 1
• Avoid corticosteroids as first-line therapy due to potential increased risk of recurrent MI 1
• Monitor CRP levels to guide treatment duration 2
• Perform echocardiography to assess for effusion size and potential tamponade 1

Special Circumstances

Pericardial Effusion Management

• Small asymptomatic effusions: Conservative management with monitoring
• Moderate to large effusions (>20mm in diastole): Consider pericardiocentesis 1
• Cardiac tamponade: Urgent pericardiocentesis is life-saving (Class I indication) 1

Recurrent Pericarditis

• Occurs in approximately 15-30% of cases without colchicine, reduced to 8-15% with colchicine 2
• For recurrences, continue or reinstitute the same treatment regimen with longer duration 1

Effusive-Constrictive Pericarditis

• Rare complication characterized by concomitant tamponade and constriction 3
• Diagnosis requires combined pericardiocentesis and cardiac catheterization
• May require pericardiectomy if persistent constriction develops

Monitoring and Follow-up

1. Short-term follow-up (1 week) to assess response to treatment 1
2. Monitor inflammatory markers (CRP) to guide treatment duration 2
3. Repeat echocardiography if symptoms worsen or to assess resolution of effusion 1
4. Taper medications only after CRP normalization and symptom resolution 2

Prognosis

• Most cases of post-LHC pericarditis resolve with appropriate anti-inflammatory therapy
• Complications are rare but include recurrent pericarditis, cardiac tamponade, and constrictive pericarditis
• The overall incidence of major complications after diagnostic cardiac catheterization is extremely low (8.2 per 10,000 procedures) 4

Pitfalls to Avoid

• Misdiagnosis: Differentiate from post-MI pericarditis, which requires different management
• Premature discontinuation of therapy before complete resolution of inflammation
• Inappropriate use of corticosteroids as first-line therapy
• Failure to recognize tamponade, which requires urgent intervention
• Overlooking late-presenting pericarditis (Dressler's syndrome) in patients with delayed symptoms after LHC