What are the treatment options for individuals at risk of myocarditis?

Treatment of Individuals at Risk of Myocarditis

For patients with myocarditis, hospitalize at an advanced heart failure center and initiate guideline-directed heart failure therapy (ACE inhibitors/ARBs, beta-blockers if stable, aldosterone antagonists), while avoiding NSAIDs and corticosteroids in typical viral myocarditis, with strict activity restriction for 3-6 months. 1, 2

Immediate Management and Hospitalization

All patients with definite myocarditis require hospitalization at an advanced heart failure center, regardless of whether symptoms appear mild or moderate. 3, 2, 4 This is critical because even seemingly stable patients can deteriorate rapidly.

• Patients with fulminant myocarditis (cardiogenic shock, sustained ventricular arrhythmias, or advanced heart block) must be transferred to centers with mechanical circulatory support capabilities, including V-A ECMO. 3, 2
• Fulminant myocarditis carries 28% mortality at 60 days despite aggressive treatment, though survivors have better long-term prognosis than non-fulminant forms. 2

Standard Medical Therapy

Guideline-directed heart failure therapy forms the cornerstone of treatment and should be initiated before discharge. 3, 2, 4

• ACE inhibitors or ARBs for neurohormonal blockade in all appropriate patients. 2
• Aldosterone antagonists for patients with mildly reduced left ventricular function and stable hemodynamics. 3, 2
• Beta-blockers only if hemodynamically stable and particularly useful for supraventricular arrhythmias—but can precipitate cardiogenic shock if cardiac function is significantly compromised. 3, 2

Critical Contraindications

NSAIDs and corticosteroids should be avoided in typical viral myocarditis as they increase inflammation and mortality. 3, 1, 5

• Animal studies demonstrate a 2- to 3-fold increase in inflammation, myocyte necrosis, and mortality with NSAIDs and aspirin in viral myocarditis. 5
• Corticosteroids can reactivate viral infections, perpetuating rather than resolving inflammation. 1
• A Cochrane systematic review found no mortality reduction with corticosteroids (RR 0.93,95% CI 0.70-1.24). 1

Exceptions Where Immunosuppression IS Indicated

Immunosuppression should be used only in specific non-viral subtypes: 3, 1, 2

• Giant cell myocarditis
• Cardiac sarcoidosis
• Eosinophilic myocarditis
• Immune checkpoint inhibitor-induced myocarditis (requires immediate high-dose methylprednisolone and permanent discontinuation of immunotherapy) 2
• MIS-A (multisystem inflammatory syndrome in adults) with hemodynamic compromise 3
• Fulminant myocarditis with biopsy-proven severe inflammatory infiltrates and hemodynamic instability 3, 1

COVID-19-Specific Considerations

For patients with concurrent COVID-19 pneumonia requiring supplemental oxygen, corticosteroids should be used. 3, 4 For associated pericardial involvement, NSAIDs may be used cautiously to alleviate chest pain, with low-dose colchicine or prednisone added for persistent symptoms. 3

Mechanical Circulatory Support

Mechanical circulatory support is required for patients developing cardiogenic shock despite optimal medical management. 3, 2, 4

• Options include percutaneous cardiopulmonary support, ECMO, or intra-aortic balloon pump. 2
• Some patients can be bridged to recovery, though the role of immunosuppression in this setting remains uncertain. 3
• Approximately 2-9% of patients require hemodynamic support with 28% mortality or transplant rate at 60 days. 6

Arrhythmia Management

Arrhythmias often resolve with resolution of acute inflammation, so management is primarily supportive. 3, 2 Insert a temporary pacemaker if symptomatic or high-grade AV block triggers ventricular tachyarrhythmias. 2

Activity Restriction

Mandate complete exercise abstinence for 3-6 months after diagnosis—this is non-negotiable. 3, 1, 2, 4

• Sustained aerobic exercise during acute viral myocarditis leads to increased mortality in animal models and can cause sudden death. 3, 1
• Competitive sport participation must be avoided for the full 3-6 month period. 3, 2
• Reassessment with clinical evaluation and functional testing is required before resuming competitive sports. 3

Follow-Up Surveillance

Follow-up testing at 3-6 months is essential to assess recovery, particularly in those with ongoing symptoms or significant myocardial involvement. 3, 2, 4

• Repeat ECG, echocardiogram, ambulatory rhythm monitor, and cardiac MRI to gauge recovery of cardiac function and inflammation. 3, 2
• This surveillance guides heart failure management and assesses prognosis. 3
• Dilated cardiomyopathy develops in 21% of patients during long-term follow-up. 2

Common Pitfalls to Avoid

• Do not use NSAIDs or high-dose aspirin unless there is significant pericardial involvement—the risk of increased inflammation and mortality outweighs potential benefits in isolated myocarditis. 3, 1, 5
• Do not allow early return to exercise—even if patients feel better, the 3-6 month restriction is based on mortality data. 3, 1
• Do not use immunosuppression empirically in typical lymphocytic viral myocarditis—it provides no benefit and may worsen outcomes. 1, 4