What is the treatment for myocarditis?

Treatment of Myocarditis

Myocarditis should be treated with supportive care focused on heart failure management, with immunosuppressive therapy reserved only for specific forms such as giant cell, cardiac sarcoidosis, or eosinophilic myocarditis. 1, 2

Initial Management

Supportive Care

• Treat according to standard heart failure guidelines for patients presenting with dilated cardiomyopathy 1
• Hospitalize patients with fever and suspected myocarditis for cardiac monitoring 2
• Avoid NSAIDs due to risk of increased inflammation and mortality 1, 2
• Maintain ACE inhibitors/ARBs unless there is significant hemodynamic compromise 2
• Continue beta-blockers in hemodynamically stable patients 2
• Consider low-dose aldosterone antagonists for patients with mildly reduced LV function 2
• Adjust diuretics based on fluid status assessment 2

Activity Restriction

• Avoid competitive sports and strenuous exercise for 3-6 months after diagnosis 1, 2
• Return to activity only when:
  • Absence of symptoms
  • Normalized cardiac function
  • Absence of arrhythmias 2

Special Considerations by Clinical Presentation

Mild/Moderate Myocarditis

• Supportive care is the mainstay of treatment 2
• Anti-inflammatory medications generally not needed if symptoms are rapidly improving 2

Fulminant Myocarditis with Hemodynamic Compromise

• Intravenous corticosteroids may be necessary 2
• Consider temporary pacemaker for heart block or ventricular arrhythmias 2
• Provide inotropic support as needed 2
• Mechanical circulatory support (MCS) may be required for cardiogenic shock despite optimal medical management 1, 2
  • Some patients can be bridged to recovery 1

Arrhythmia Management

• Acute arrhythmia management is supportive, as arrhythmias often resolve with resolution of inflammation 1
• For drug-refractory ventricular arrhythmias, endocardial and epicardial radiofrequency catheter ablation can be effective 1
• Avoid medications that prolong QT interval 2

Specific Etiologies Requiring Targeted Treatment

Immunosuppressive Therapy

• Generally not indicated for acute lymphocytic myocarditis in adults 1
• Indicated for:
  • Giant cell myocarditis
  • Cardiac sarcoidosis
  • Eosinophilic myocarditis 1, 2
• Consider for COVID-19 associated myocarditis, especially with concurrent pneumonia requiring oxygen 2

Infectious Causes

• Provide appropriate antimicrobial therapy for bacterial causes (e.g., Lyme disease, diphtheria) 2

Follow-Up and Monitoring

• Perform surveillance testing at 3-6 months after presentation 2:
  • ECG
  • Echocardiogram
  • Ambulatory rhythm monitor
  • Cardiac MRI
• Continue guideline-directed heart failure therapy and titrate as appropriate in outpatient setting 2
• Consider chest CT at 3-6 months in patients with dyspnea or abnormal pulmonary function tests 2

Advanced Therapies

• Consider cardiac transplantation for patients with refractory heart failure 1
  • Survival rates after transplantation for adult patients with myocarditis are similar to other causes of cardiac failure
  • Higher post-transplantation risk in children if active myocarditis is present in the explanted heart 1

Caveats and Pitfalls

• Avoid NSAIDs in acute myocarditis due to risk of increased inflammation and mortality (exception: cases with suspected pericardial involvement) 1, 2
• The role of immunosuppression in patients requiring mechanical circulatory support remains uncertain 1
• Recognize that mortality is significantly higher in fulminant myocarditis (up to 42% short-term mortality) compared to uncomplicated cases 2
• Be vigilant for persistent AV blocks that may develop and require permanent pacing 2
• Recent data from JAMA (2023) indicates that while corticosteroids are often used for specific forms of myocarditis, this practice is based largely on anecdotal evidence 3