What is the recommended treatment for myocarditis?

Treatment of Myocarditis

The treatment of myocarditis depends primarily on clinical severity and etiology: supportive care with guideline-directed medical therapy for heart failure forms the foundation, while corticosteroids are reserved for specific scenarios including COVID-19 myocarditis with pneumonia requiring oxygen, hemodynamic compromise, MIS-A, or biopsy-proven eosinophilic/giant cell infiltrates. 1

Initial Management Based on Severity

Hospitalization Strategy

• Patients with definite mild-to-moderate myocarditis require hospitalization, ideally at an advanced heart failure center 1
• Fulminant myocarditis (cardiogenic shock, sustained ventricular arrhythmias, advanced AV block) demands management at centers with mechanical circulatory support expertise, including V-A ECMO capability 1
• Approximately 75% of hospitalized myocarditis patients have uncomplicated courses with near-zero mortality, while those with acute heart failure or ventricular arrhythmias face 12% in-hospital mortality or transplant rates 2
• The 2% to 9% presenting with hemodynamic instability requiring inotropes or mechanical support have approximately 28% mortality or transplant rates at 60 days 2

Supportive Care and Heart Failure Management

Guideline-Directed Medical Therapy

• Initiate standard heart failure therapies as appropriate and continue after discharge 1
• Low-dose aldosterone system inhibitors may be used empirically in patients with mildly reduced LV systolic function and stable hemodynamics 1
• Beta-blockers are helpful for supraventricular arrhythmias if hemodynamically stable, but can precipitate cardiogenic shock in severely compromised patients 1

Critical pitfall: Beta-blockade requires careful hemodynamic assessment before initiation to avoid precipitating shock 1

Etiology-Specific Immunosuppressive Therapy

COVID-19-Related Myocarditis

• Patients with myocarditis AND COVID-19 pneumonia requiring supplemental oxygen should receive corticosteroids 1
• Intravenous corticosteroids may be considered for suspected or confirmed COVID-19 myocarditis with hemodynamic compromise or MIS-A 1
• MIS-A presents as a hyperinflammatory state with acute heart failure/cardiogenic shock without sepsis, often with elevated inflammatory biomarkers and ferritin 1

Biopsy-Proven Specific Etiologies

• Empiric corticosteroids may be considered for biopsy evidence of severe myocardial inflammatory infiltrates or fulminant myocarditis, balanced against infection risk 1
• Immunosuppression (corticosteroids) is appropriate for eosinophilic or giant cell myocardial infiltrations or systemic autoimmune disorder-related myocarditis 2
• These biopsy findings are very rare in COVID-19, and the magnitude of benefit from immune-modifying therapy remains incompletely defined 1

Important nuance: While corticosteroids are frequently used in clinical practice, this is largely based on anecdotal evidence, and the specific immune cells that should be targeted to improve outcomes remain unclear 2

Pericardial Involvement Management

Anti-Inflammatory Therapy

• For suspected pericardial involvement, treatment with NSAIDs, colchicine, and/or prednisone is reasonable 1
• NSAIDs may be used to alleviate chest pain and inflammation in patients with associated pericardial involvement 1
• Low-dose colchicine or prednisone may be added for persistent chest pain, with dose tapering based on symptoms and clinical findings 1
• Interleukin-1 antagonists represent innovative treatment approaches for pericarditis 3

Post-Stabilization and Follow-Up

Diagnostic Confirmation

• Once patients with cardiogenic shock or hemodynamic instability stabilize, perform CMR before hospital discharge to confirm diagnosis and assess extent of ventricular dysfunction and inflammation 1

Surveillance Strategy

• Consider follow-up testing (ECG, echocardiogram, ambulatory rhythm monitor, CMR) at 3-6 months after presentation, particularly with ongoing cardiac symptoms or findings suggesting significant/worsening myocardial involvement 1
• Recent guidelines introduce risk stratification that influences both treatment and follow-up, abandoning fixed waiting periods for resuming sports and work 3

Vaccine-Associated Myocarditis

• Vaccine-associated myocarditis should be diagnosed, categorized, and treated analogously to myocarditis following SARS-CoV-2 infection 1
• COVID-19 vaccination maintains a very favorable benefit-to-risk ratio for all age and sex groups despite rare myocarditis cases 1