What is the treatment for myocarditis?

Treatment for Myocarditis

The treatment for myocarditis should follow standard heart failure management protocols, with hospitalization recommended for patients with definite myocarditis that is either mild or moderate in severity, ideally at an advanced heart failure center. 1

Diagnosis and Initial Assessment

• Initial testing for suspected myocarditis should include ECG, cardiac troponin (preferably high-sensitivity assay), and echocardiogram 1
• Cardiology consultation is recommended for patients with rising troponin levels and/or ECG or echocardiographic abnormalities concerning for myocarditis 1
• Cardiac MRI is recommended in hemodynamically stable patients to confirm the diagnosis and assess the extent of ventricular dysfunction and inflammation 1
• Endomyocardial biopsy (EMB) should be performed in patients with clinically suspected unexplained acute myocarditis who require inotropic support or mechanical circulatory support, and those with high-grade heart block, sustained ventricular arrhythmias, or failure to respond to guideline-based therapy 1

Treatment Algorithm

1. Supportive Care and Standard Heart Failure Management

• Treat according to standard heart failure guidelines for patients with myocarditis presenting as dilated cardiomyopathy 1
• For patients with mildly reduced left ventricular function and stable hemodynamics, consider:
  • Low-dose aldosterone system inhibitors 1
  • Beta-blockers for patients with supraventricular arrhythmias, if hemodynamically stable 1
  • Guideline-directed medical therapy for heart failure should be initiated before discharge and titrated appropriately in the outpatient setting 1

2. Management Based on Clinical Presentation

For Patients with Hemodynamic Instability:

• Patients with fulminant myocarditis (cardiogenic shock, sustained ventricular arrhythmias, advanced AV block) should be managed at centers with expertise in advanced heart failure 1
• Mechanical circulatory support (including V-A extracorporeal membrane oxygenation) may be required for patients who develop cardiogenic shock despite optimal medical management 1
• Some patients with myocarditis can be bridged to recovery with mechanical support 1

For Patients with COVID-19 Myocarditis:

• Patients with myocarditis and COVID-19 pneumonia requiring supplemental oxygen should be treated with corticosteroids 1
• Intravenous corticosteroids may be considered for suspected or confirmed COVID-19 myocarditis with hemodynamic compromise or multisystem inflammatory syndrome in adults (MIS-A) 1

For Patients with Pericardial Involvement:

• Nonsteroidal anti-inflammatory drugs (NSAIDs) may be used to alleviate chest pain and inflammation 1
• Low-dose colchicine or prednisone may be added for persistent chest pain, with a plan to taper based on symptoms and clinical findings 1

3. Special Considerations for Immunosuppressive Therapy

• Immunosuppression is generally not indicated for the management of acute lymphocytic myocarditis in adults 1
• Immunosuppressive therapy should be considered in specific forms of myocarditis:
  • Giant cell myocarditis 1, 2
  • Cardiac sarcoidosis 1
  • Eosinophilic myocarditis 1, 2
  • Myocarditis due to systemic autoimmune disorders 2
• Empiric use of corticosteroids may be considered in patients with biopsy evidence of severe myocardial inflammatory infiltrates or fulminant myocarditis, balanced against infection risk 1

Important Precautions and Follow-up

• NSAIDs should generally be avoided in viral myocarditis (except when there is pericardial involvement) due to the risk of increased inflammation and mortality 1
• Sustained aerobic exercise during acute viral myocarditis should be avoided 1
• Competitive sport participation should be avoided for 3-6 months after the diagnosis of myocarditis 1
• Follow-up surveillance testing (ECG, echocardiogram, ambulatory rhythm monitor, CMR) should be performed 3-6 months after presentation to:
  • Gauge recovery of cardiac function and inflammation
  • Guide heart failure management
  • Assess prognosis 1

Prognosis

• Approximately 75% of patients admitted with myocarditis have an uncomplicated course with a mortality rate of approximately 0% 2
• Acute myocarditis complicated by acute heart failure or ventricular arrhythmias is associated with a 12% rate of either in-hospital mortality or need for heart transplant 2
• Patients with hemodynamic instability have an approximately 28% rate of mortality or heart transplant at 60 days 2
• The overall rate of survival after cardiac transplantation for adult patients with myocarditis is similar to that for other causes of cardiac failure 1

Common Pitfalls to Avoid

• Failing to recognize the severity of myocarditis, which can rapidly progress to fulminant disease
• Inappropriate use of beta-blockers in patients with severe cardiac compromise, which can precipitate cardiogenic shock 1
• Overuse of immunosuppressive therapy in viral myocarditis without specific indications 1
• Allowing patients to return to competitive sports too early after myocarditis 1
• Inadequate follow-up monitoring for recovery of cardiac function and inflammation 1