What is the treatment for myocarditis?

Treatment of Myocarditis

The treatment of myocarditis should include hospitalization for patients with definite myocarditis (even mild or moderate severity), ideally at an advanced heart failure center, with guideline-directed medical therapy for heart failure as the cornerstone of management. 1

Diagnostic Approach

Before initiating treatment, proper diagnosis is essential:

• Initial evaluation should include ECG, cardiac troponin measurement (preferably high-sensitivity assay), and echocardiogram 1, 2
• Cardiac MRI is recommended in hemodynamically stable patients with suspected myocarditis 1, 2
• Endomyocardial biopsy should be performed in patients with:
  • Rapidly deteriorating cardiac function requiring inotropic support or mechanical circulatory support 1
  • Mobitz type 2 second-degree or higher heart block 1
  • Sustained or symptomatic ventricular tachycardia 1
  • Failure to respond to guideline-based therapy 1

Treatment Algorithm

1. Supportive Care and Heart Failure Management

• Initiate guideline-directed medical therapy for heart failure in patients with reduced ejection fraction 1
• Continue heart failure medications indefinitely, even after improvement in symptoms or LVEF 1
• Avoid nonsteroidal anti-inflammatory drugs (NSAIDs) due to risk of increased inflammation and mortality 1
• Restrict physical activity and avoid competitive sports for 3-6 months after diagnosis 1

2. Specific Treatments Based on Etiology

• For myocarditis with COVID-19 pneumonia (requiring supplemental oxygen):

  • Administer corticosteroids 1

• For suspected pericardial involvement:

  • Consider NSAIDs, colchicine, and/or prednisone 1

• For COVID-19 myocarditis with hemodynamic compromise or MIS-A:

  • Consider intravenous corticosteroids 1

• For specific forms of myocarditis:

  • Giant cell myocarditis, cardiac sarcoidosis, or eosinophilic myocarditis: Implement treatments directed at modifying the immune response 1
  • Autoimmune-associated myocarditis: Initiate methylprednisolone 1000 mg/day IV, followed by prednisone 1-2 mg/kg/day orally for 1-2 weeks 3
  • Immune checkpoint inhibitor-associated myocarditis: Withhold further therapy and initiate high-dose corticosteroids (methylprednisolone 1000 mg/day followed by oral prednisone 1 mg/kg/day) 1

3. Management of Complications

• For cardiogenic shock despite optimal medical management:

  • Consider mechanical circulatory support (MCS) 1
  • Some patients with myocarditis can be bridged to recovery with MCS 1

• For drug-refractory ventricular arrhythmias:

  • Consider endocardial and epicardial radiofrequency catheter ablation 1

• For steroid-refractory or high-grade myocarditis with hemodynamic instability:

  • Consider additional immunosuppressive therapies such as antithymocyte globulin, infliximab (except in heart failure patients), mycophenolate mofetil, or abatacept 1

Follow-up and Monitoring

• Reassess for resolution of myocardial inflammation after approximately 8 weeks 1
• Before returning to competitive sports, ensure:
  • Absence of cardiopulmonary symptoms 1
  • Resolution of laboratory evidence of myocardial injury 1
  • Normalization of LV systolic function 1
  • Absence of spontaneous/inducible cardiac arrhythmias on ECG monitoring and exercise stress testing 1

Special Considerations

• Immunosuppression is generally not indicated for the management of acute lymphocytic myocarditis in adults 1
• The role of immunosuppression in patients requiring mechanical circulatory support remains uncertain 1
• Vaccine-associated myocarditis should be diagnosed, categorized, and treated similarly to myocarditis following SARS-CoV-2 infection 1
• Cardiac transplantation may be considered for patients with refractory heart failure, with similar survival rates to other causes of cardiac failure 1

Common Pitfalls to Avoid

• Do not use NSAIDs in acute myocarditis without pericardial involvement 1
• Do not allow early return to competitive sports (wait 3-6 months) 1
• Do not miss concomitant pericardial involvement, which requires specific treatment 1
• Do not overlook the need for specialized care - fulminant myocarditis should be managed at centers with expertise in advanced heart failure, mechanical circulatory support, and other advanced therapies 1