What is the workup, etiology, and treatment for pericarditis?

Workup, Etiology, and Treatment for Pericarditis

The diagnosis of pericarditis requires at least 2 of 4 criteria (chest pain, pericardial friction rub, ECG changes, and pericardial effusion), and first-line treatment consists of aspirin/NSAIDs plus colchicine for 3 months, with treatment duration guided by symptom resolution and CRP normalization. 1, 2

Diagnostic Workup

Essential Initial Tests

• Clinical evaluation: Sharp, pleuritic retrosternal chest pain that improves when sitting up/leaning forward 2
• Auscultation: Pericardial friction rub (present in <30% of cases) 2, 3
• ECG: Widespread concave upward ST-segment elevation, PR segment depression, absence of reciprocal changes 1, 2
• Echocardiography: Assess for pericardial effusion and rule out tamponade 1
• Laboratory tests:
  • CRP and ESR (markers of inflammation)
  • WBC count with differential
  • Renal and liver function tests
  • Cardiac biomarkers (troponin, creatine kinase) 1
• Chest X-ray: Evaluate cardiac silhouette and rule out other pulmonary pathology 1, 2

Second-Level Testing

• CT and/or CMR: Indicated for:
  • Assessment of pericardial thickness
  • Evaluation of calcifications (CT)
  • Determining degree and extension of pericardial involvement
  • Confirming diagnosis in atypical cases 1
• Cardiac catheterization: When non-invasive methods don't provide definitive diagnosis of constrictive pericarditis 1

Etiology

Common Causes

1. Idiopathic/Viral (most common in developed countries) 1, 3
2. Post-cardiac injury: Post-myocardial infarction, post-pericardiotomy syndrome 4, 3
3. Autoimmune diseases: Systemic lupus erythematosus, rheumatoid arthritis 4
4. Infectious:
   • Bacterial: Staphylococcus, Streptococcus, Haemophilus 5
   • Tuberculous: Most common cause in endemic areas 3, 5
5. Neoplastic: Primary or metastatic tumors 1
6. Drug-induced: Procainamide, hydralazine, isoniazid 6
7. Uremic: In patients with renal failure 1
8. Traumatic: Direct injury 5

Risk Stratification

High-Risk Features (Requiring Hospitalization)

• Fever >38°C
• Subacute onset
• Large pericardial effusion
• Cardiac tamponade
• Failure to respond to NSAIDs
• Immunosuppression
• Trauma
• Oral anticoagulant therapy
• Myopericarditis with elevated troponins 1, 2

Low-Risk Features (Outpatient Management)

• Absence of high-risk features
• Good response to initial anti-inflammatory therapy 1

Treatment Algorithm

1. Acute Pericarditis (First Episode)

First-Line Therapy

• NSAIDs:

  • Ibuprofen: 600 mg every 8 hours (1800-2400 mg/day) OR
  • Aspirin: 750-1000 mg every 8 hours (2250-3000 mg/day) 1, 2
  • Continue until complete symptom resolution and CRP normalization (typically 1-2 weeks)
  • Taper by decreasing doses 250-500 mg every 1-2 weeks 1
  • Always add gastroprotection

• PLUS Colchicine:

  • 0.5 mg once daily if <70 kg
  • 0.5 mg twice daily if ≥70 kg
  • Duration: 3 months 1, 2, 3

Second-Line Therapy (Only if First-Line Fails or Contraindicated)

• Low-dose corticosteroids:
  • Prednisone 0.2-0.5 mg/kg/day
  • Only after excluding infectious causes
  • Maintain until symptom resolution and CRP normalization
  • Taper slowly to avoid recurrence 1, 2

2. Recurrent Pericarditis

First-Line Therapy

• NSAIDs/Aspirin: Same doses as for acute pericarditis 1
• PLUS Colchicine: Same doses but extended to 6 months 1, 3

For Multiple Recurrences

• Triple therapy: NSAIDs + colchicine + low-dose corticosteroids 1
• IL-1 blockers: For steroid-dependent cases with multiple recurrences 3

3. Specific Etiologies

Tuberculous Pericarditis

• Standard anti-TB drugs for 6 months:
  • Isoniazid 300 mg/day
  • Rifampin 600 mg/day
  • Pyrazinamide 15-30 mg/kg/day
  • Ethambutol 15-25 mg/kg/day 1, 5
• Consider adding corticosteroids 1, 5

Bacterial (Purulent) Pericarditis

• Urgent pericardial drainage
• Intravenous antibiotics (e.g., vancomycin, ceftriaxone, ciprofloxacin)
• Consider pericardiectomy if not improving 1, 5

Neoplastic Pericarditis

• Systemic antineoplastic treatment
• Extended pericardial drainage
• Consider intrapericardial cytostatic/sclerosing agents 1

Follow-up and Monitoring

• Initial follow-up: 1-2 weeks after starting treatment
• Subsequent follow-up: Every 1-2 months until treatment completion
• Monitor:
  • Symptom resolution
  • CRP normalization (key marker to guide treatment duration)
  • ECG changes resolution
  • Resolution of pericardial effusion if present 1, 2

Common Pitfalls to Avoid

1. Overuse of corticosteroids as first-line therapy (increases recurrence risk) 1, 2
2. Inadequate treatment duration (leads to recurrences) 2
3. Failure to add colchicine (doubles recurrence risk) 2, 3
4. Missing high-risk features requiring hospitalization 2
5. Rapid tapering of medications before complete resolution 1
6. Exercise restriction: Athletes should restrict activity for at least 3 months; non-athletes until symptoms resolve and tests normalize 1

Prognosis

• Most patients with idiopathic/viral pericarditis have good long-term prognosis 1
• Recurrence rate: 15-30% without colchicine, reduced to 8-15% with colchicine 1, 2
• Risk of constrictive pericarditis: <1% in idiopathic/viral cases, 20-30% in bacterial cases (especially TB) 1
• Cardiac tamponade: Rare in idiopathic pericarditis, more common with specific etiologies (malignancy, TB) 1