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Acute infective pericarditis — Clinical Guidelines

Overview

Acute infective pericarditis is characterized by inflammation of the pericardium, often triggered by infectious agents such as viruses, bacteria, or fungi. This condition can lead to significant morbidity due to symptoms like chest pain, pericardial effusion, and potential complications such as cardiac tamponade or constrictive pericarditis. Recurrent episodes are common, particularly in patients with autoimmune predispositions or inadequate initial treatment. Understanding and managing acute infective pericarditis is crucial in day-to-day practice to prevent complications and improve patient outcomes 1 2 3 4.

Pathophysiology

The pathophysiology of acute infective pericarditis involves a complex interplay of immune responses triggered by infectious agents. Upon pericardial injury, damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs) activate nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), leading to the transcription of inflammatory cytokines and precursors 1. This activation stimulates the formation of the NLRP3 inflammasome, which processes and releases interleukin-1β (IL-1β), a key mediator of inflammation. Additionally, the arachidonic acid pathway is activated through phospholipase A2, resulting in the production of prostaglandins and thromboxanes, further exacerbating inflammation 1. These molecular mechanisms collectively drive the clinical manifestations of pericarditis, including chest pain, pericardial friction rub, and electrocardiographic changes 1 2.

Epidemiology

Acute infective pericarditis affects approximately 4.4% of patients presenting with non-ischemic chest pain in emergency departments, with a slight male predominance 3. The incidence varies geographically, with tuberculosis being a significant cause in developing countries, whereas idiopathic or viral causes predominate in developed settings like the UK 2. Recurrent pericarditis occurs in 15–30% of patients within 18 months following the first episode, with higher recurrence rates noted in patients with autoimmune conditions or those treated with high-dose glucocorticoids 1 6. Trends suggest that improved diagnostic techniques and tailored therapeutic approaches are reducing recurrence rates and complications over time 1 4.

Clinical Presentation

Acute infective pericarditis typically presents with characteristic pleuritic chest pain, often exacerbated by inspiration or lying supine. Other common symptoms include fever, malaise, and dyspnea. Physical examination may reveal a pericardial friction rub, which, although transient, is highly specific for pericarditis 3 4. Electrocardiographically, diffuse ST-segment elevations and PR depressions are hallmark findings, though these may evolve over time. Atypical presentations can include milder symptoms in recurrent episodes, necessitating imaging and biomarker assessments for confirmation 4. Red-flag features include hypotension, muffled heart sounds, and signs of tamponade, indicating urgent intervention 3.

Diagnosis

The diagnosis of acute infective pericarditis involves a combination of clinical criteria and diagnostic tests. Key diagnostic steps include:

Clinical Criteria: At least two of the following must be present:

- Characteristic chest pain - Pericardial friction rub - Electrocardiographic changes (ST-segment elevation, PR depression, or T-wave inversion) - Evidence of pericardial effusion on imaging

Diagnostic Tests:

- Electrocardiogram (ECG): ST-segment elevations, PR depressions, or T-wave inversions. - Echocardiography: To detect pericardial effusion and assess for tamponade. - Cardiac MRI: Useful for detecting active inflammation and guiding management in recurrent cases 3 4.

Differential Diagnosis:

- Acute Coronary Syndrome: Elevated cardiac biomarkers, ECG changes without friction rub. - Pneumonia: Chest pain localized to one side, respiratory symptoms, and abnormal chest X-ray findings. - Pleurisy: Localized chest pain, pleural effusion without ECG changes typical of pericarditis 3.

Management

First-Line Treatment

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs):

Drugs: Ibuprofen, naproxen

Dose: Typically 400-800 mg orally every 6-8 hours

Duration: Until symptoms resolve (usually 1-2 weeks)

Monitoring: Renal function, gastrointestinal symptoms

Contraindications: Peptic ulcer disease, renal impairment, uncontrolled hypertension 1 2 3.

Colchicine:

Dose: 0.5–1.5 mg twice daily

Duration: 3 months or longer if recurrent episodes are suspected

Benefits: Reduces recurrence risk by more than 50% 2 3.

Second-Line Treatment

Glucocorticoids:

Drugs: Prednisolone, methylprednisolone

Dose: Low to moderate dose (e.g., prednisolone 40 mg daily)

Indications: Failure of NSAIDs and colchicine, autoimmune disorders, contraindications to NSAIDs

Duration: Gradual tapering over 2-4 weeks

Monitoring: Infection risk, adrenal suppression, metabolic effects 1 2.

Refractory or Specialist Escalation

Interleukin-1 (IL-1) Inhibitors:

Drugs: Anakinra (IL-1 receptor antagonist), rilonacept (decoy receptor), canakinumab (IL-1β monoclonal antibody)

Dose: Anakinra 100 mg daily subcutaneously; rilonacept 162 mg subcutaneously every 2 weeks; canakinumab 150 mg intravenously every 8 weeks

Indications: Recurrent pericarditis unresponsive to NSAIDs, colchicine, and glucocorticoids; high-risk features (multiple episodes, elevated inflammatory markers)

Monitoring: Adverse effects (infections, injection site reactions) 1 2 4.

Surgical Intervention

Pericardiectomy: Considered in patients refractory to medical therapy with persistent constrictive pericarditis or recurrent pericardial effusion 2.

Complications

Acute Complications:

Cardiac Tamponade: Hypotension, muffled heart sounds, pulsus paradoxus; requires immediate pericardiocentesis.

Pericardial Constriction: Chronic symptoms of dyspnea, fatigue; confirmed by imaging and hemodynamic assessment.

Long-Term Complications:

Recurrent Episodes: Increased risk with prior corticosteroid use, inadequate treatment duration.

Quality of Life Impact: Reduced physical activity, work capacity, and psychological well-being 1 6.

Prognosis & Follow-Up

The prognosis for acute infective pericarditis is generally good, with a <0.5% risk of constrictive pericarditis in idiopathic cases. Prognostic indicators include the absence of autoimmune conditions, successful initial treatment, and timely tapering of anti-inflammatory therapies based on clinical and biomarker resolution. Follow-up should include regular clinical assessments, ECG monitoring, and echocardiography every 6-12 months for patients with recurrent episodes 1 2 3.

Special Populations

Pregnancy

Management focuses on NSAIDs and colchicine, avoiding high-dose glucocorticoids unless absolutely necessary due to potential fetal risks. Close monitoring of maternal and fetal well-being is essential 5.

Pediatrics

Treatment principles are similar, but dosing adjustments are crucial based on weight. NSAIDs and colchicine are generally well-tolerated, with close follow-up to monitor for recurrence and complications 5.

Elderly

Increased vigilance for drug interactions and comorbidities is necessary. NSAIDs should be used cautiously due to higher risks of renal and gastrointestinal complications; colchicine and glucocorticoids may be preferred with careful monitoring 5.

Autoimmune Disorders

Patients with underlying autoimmune conditions have a higher risk of recurrence. Tailored management involving control of the underlying disease alongside pericarditis treatment is crucial 1 13.

Key Recommendations

Initiate NSAIDs as first-line therapy for symptom relief and resolution of inflammation in acute infective pericarditis (Evidence: Strong) 1 2 3.

Add colchicine for 3 months to reduce recurrence risk in patients with acute pericarditis (Evidence: Moderate) 2 3.

Reserve glucocorticoids for refractory cases or those with contraindications to NSAIDs and colchicine (Evidence: Moderate) 1 2.

Consider IL-1 inhibitors in patients with recurrent pericarditis unresponsive to conventional therapy or high-risk features (Evidence: Moderate) 1 4.

Perform echocardiography to assess pericardial effusion and rule out tamponade (Evidence: Strong) 3.

Monitor inflammatory markers to guide treatment duration and tapering (Evidence: Moderate) 1 4.

Avoid rapid tapering of anti-inflammatory therapy until clinical symptoms and biomarkers normalize (Evidence: Expert opinion) 1.

Refer patients with recurrent pericarditis for specialist evaluation, especially if multiple episodes or high-risk features are present (Evidence: Expert opinion) 1 4.

Consider pericardiectomy in cases of refractory constrictive pericarditis or persistent effusion (Evidence: Weak) 2.

Manage autoimmune comorbidities aggressively to reduce recurrence risk in susceptible patients (Evidence: Moderate) 1 13.

References

1 Bonaventura A, Santagata D, Vecchié A, Abbate A. Current Drug Treatment for Acute and Recurrent Pericarditis. Drugs 2025. link 2 Ismail TF. Acute pericarditis: Update on diagnosis and management. Clinical medicine (London, England) 2020. link 3 Peterson TA, Turner SP, Dolezal KA. Acute Pericarditis: Rapid Evidence Review. American family physician 2024. link 4 Vecchiè A, Dell M, Mbualungu J, Ho AC, VAN Tassell B, Abbate A. Recurrent pericarditis: an update on diagnosis and management. Panminerva medica 2021. link 5 Schwier NC, Cornelio CK, Epperson TM. Managing acute and recurrent idiopathic pericarditis. JAAPA : official journal of the American Academy of Physician Assistants 2020. link 6 Imazio M, Demichelis B, Parrini I, Cecchi E, Demarie D, Ghisio A et al.. Management, risk factors, and outcomes in recurrent pericarditis. The American journal of cardiology 2005. link

Acute infective pericarditis