What is the workup and treatment for a patient presenting with pericarditis?

Workup and Treatment for Pericarditis

Diagnosis

Acute pericarditis is diagnosed when at least 2 of the following 4 criteria are present: pericarditic chest pain, pericardial friction rub, new widespread ST-elevation or PR depression on ECG, or new/worsening pericardial effusion. 1

Initial Diagnostic Workup (First-Level)

All patients with suspected pericarditis require the following mandatory tests 1:

• Physical examination with auscultation for pericardial friction rub (present in <30% of cases) 2
• 12-lead ECG to identify widespread ST-elevation or PR depression (present in 25-60% of cases) 1, 2
• Transthoracic echocardiography to assess for pericardial effusion (present in ~60% of cases) and evaluate for tamponade 1
• Chest X-ray (typically normal unless effusion exceeds 300 mL) 1
• Laboratory tests including:
  • Inflammatory markers: CRP and/or ESR, white blood cell count with differential 1
  • Cardiac biomarkers: troponin and creatine kinase (may be elevated with concomitant myocarditis) 1
  • Renal function and liver tests 1

Risk Stratification

High-risk features requiring hospital admission include 1:

• Fever >38°C (>100.4°F) 1
• Subacute course (symptoms developing over days/weeks) 1
• Large pericardial effusion (diastolic echo-free space >20 mm) 1
• Cardiac tamponade 1
• Failure to respond to NSAIDs within 7 days 1

Low-risk patients without these features can be managed as outpatients with follow-up at 1 week to assess treatment response. 1

Second-Level Diagnostic Testing

Advanced imaging and invasive procedures are indicated for high-risk patients 1:

• CT and/or cardiac MRI for further characterization of pericardial involvement 1
• Pericardiocentesis or surgical drainage indicated for:
  • Cardiac tamponade 1
  • Suspected bacterial or neoplastic pericarditis 1
  • Symptomatic moderate-to-large effusions not responding to medical therapy 1

When pericardial fluid is obtained, perform cytology, PCR for tuberculosis, and aerobic/anaerobic cultures 1. Note that searching for specific etiology is not mandatory in low-risk patients in developed countries, as 80-90% of cases are idiopathic/viral with benign prognosis 1, 3.

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Treatment

First-Line Therapy

The cornerstone of treatment is combination therapy with NSAIDs PLUS colchicine for all patients with acute pericarditis. 1, 4

NSAID Dosing 4:

• Aspirin 750-1000 mg every 8 hours OR
• Ibuprofen 600 mg every 8 hours
• Duration: 1-2 weeks initially, then taper gradually (e.g., aspirin by 250-500 mg every 1-2 weeks) 4
• Continue until symptoms resolve AND CRP normalizes 1, 4
• Always provide gastroprotection 4

Colchicine Dosing 1, 4:

• Weight-adjusted dosing:
  • 0.5 mg once daily if <70 kg 1, 4
  • 0.5 mg twice daily if ≥70 kg 1, 4
• Duration: 3 months for acute pericarditis 1, 4
• Duration: 6 months for recurrent pericarditis 1

Colchicine reduces recurrence rates from 37.5% to 16.7% (absolute risk reduction of 20.8%). 2 Without colchicine, recurrence rates are 15-30% after the first episode and increase to 50% after the first recurrence 4, 2, 3.

Monitoring Treatment Response

• Use CRP to guide treatment duration and assess response to therapy 1, 4
• Evaluate response after 1 week 1
• Taper medications only when symptoms are absent AND CRP is normalized 4

Second-Line Therapy

Corticosteroids are NOT recommended as first-line therapy due to increased risk of chronicity and recurrence. 1, 4 They should only be considered when 1, 4:

• Contraindication to NSAIDs/colchicine exists
• Failure of first-line therapy after adequate trial
• Infectious causes have been excluded 4

When corticosteroids are necessary, use low-to-moderate doses (prednisone 0.2-0.5 mg/kg/day) rather than high doses 4.

Activity Restriction

• Exercise restriction until symptoms resolve and CRP, ECG, and echocardiogram normalize 4
• For athletes, restrict exercise for at least 3 months 4

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Special Clinical Scenarios

Tuberculous Pericarditis

• In endemic areas, empiric anti-TB chemotherapy is recommended for exudative pericardial effusion after excluding other causes 1
• Standard anti-TB drugs for 6 months to prevent constrictive pericarditis 1
• Pericardiectomy if no improvement or deterioration after 4-8 weeks of therapy 1
• Adjunctive corticosteroids may be considered in HIV-negative patients but avoided in HIV-associated TB pericarditis 4

Uremic Pericarditis

• Intensify dialysis as first-line treatment 4
• Consider pericardial aspiration/drainage if non-responsive 4
• Colchicine is contraindicated in severe renal impairment 4

Purulent Pericarditis

• Requires immediate empiric intravenous antimicrobial therapy and urgent drainage 4
• With aggressive management, 85% survival rate with good long-term outcomes 4

Neoplastic Pericarditis

• Cytological analysis of pericardial fluid for confirmation 1
• Extended pericardial drainage to prevent recurrence and provide intrapericardial therapy 1
• Systemic antineoplastic treatment for confirmed cases 1
• Consider intrapericardial instillation of cytostatic/sclerosing agents to prevent recurrences 1

Constrictive Pericarditis

• Pericardiectomy is the mainstay of treatment for chronic permanent constriction 1
• Cardiac catheterization indicated when non-invasive methods don't provide definitive diagnosis 1

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Critical Pitfalls to Avoid

• Inadequate treatment of the first episode is the most common cause of recurrence 4
• Never use corticosteroids as first-line therapy - they provide rapid symptom control but increase risk of chronicity and recurrence 4
• Do not use colchicine for isolated pericardial effusion without inflammation (normal CRP) - it is ineffective and increases side effects 4
• Ensure adequate treatment duration - less than 3 months of colchicine increases recurrence risk 4
• Do not taper therapy prematurely - wait until both symptoms resolve AND CRP normalizes 4
• Risk of constrictive pericarditis varies by etiology: <1% for idiopathic/viral, 2-5% for autoimmune/neoplastic, and 20-30% for bacterial causes 4