Written by Vivian Lei
Spoon Feed
This expert consensus document serves as a guide for all clinicians managing myocarditis, including a five-step care pathway, risk stratification framework, and long-term surveillance recommendations.
My, oh, myocarditis!
We’ve covered myocarditis before. With new clinical advances and an evolving understanding of myocarditis, this document provides a structured five-step care pathway for evaluating suspected myocarditis.
Step 1: Prompt recognition of clinical syndrome
- Three classic presentations:
- Chest pain
- Arrhythmia (palpitations, syncope)
- Heart failure and cardiogenic shock
- Consider in combination with history of recent viral illness, prior myocarditis or autoimmune disease, family history of cardiomyopathy/sudden death, or exposure to known cardiotoxin.
- Initial work-up:
- Electrocardiogram (ECG): Non-specific ST-T wave changes, conduction abnormalities.
- Cardiac biomarkers: hs-cTn, CRP, natriuretic peptide level.
- Echocardiography: Assesses ventricular function, wall motion abnormalities, and pericardial effusion.
- Exclusion of coronary artery disease with coronary angiography if clinically indicated.
Step 2: Triage – Assess need for:
- Hospitalization.
- Referral or transfer to an advanced heart failure center.
- Emergent circulatory support or pacemaker.
Step 3: Confirmatory diagnostics
- Cardiac magnetic resonance (CMR) imaging: Identifies edema, fibrosis, and necrosis using T1/T2 mapping.
- Endomyocardial biopsy (EMB): Recommended for uncertain cases, refractory heart failure, or arrhythmogenic myocarditis.
Step 4: Treatment
- Medical therapy: Guideline-directed heart failure medications, including beta-blockers, ACE inhibitors/ARBs, and SGLT2 inhibitors.
- Activity restriction: Competitive sports are contraindicated for 3–6 months post-diagnosis.
- Immunosuppressive therapy: Considered in select cases (autoimmune myocarditis, giant cell myocarditis).
- Advanced therapies: Indications for arrhythmia management, ventricular assist devices (VADs) or cardiac transplantation.
Step 5: Longitudinal Surveillance
- Patients require serial imaging and biomarker monitoring even after symptom resolution.
- Genetic testing and counseling is recommended for idiopathic myocarditis.
- Assessment for return to strenuous physical activity.
A novel four-stage classification system is also introduced to guide clinicians on risk stratification and therapeutic interventions:
Stage A: At-risk patients (e.g. genetic predisposition, autoimmune disorders, toxin exposure).
Stage B: Asymptomatic myocarditis with imaging or biomarker abnormalities.
Stage C: Symptomatic myocarditis with structural or functional myocardial dysfunction.
Stage D: Advanced myocarditis with hemodynamic instability, requiring mechanical circulatory support or transplant evaluation.
How will this change my practice?
Working in the emergency department, patients with myocarditis can have heterogeneous presentations, ranging from asymptomatic cases to fulminant cardiogenic shock. Knowing that a standardized management framework exists is helpful in caring for these patients and provides a shared understanding among all clinicians in delivering the most evidence-based care.
Source
2024 ACC Expert Consensus Decision Pathway on Strategies and Criteria for the Diagnosis and Management of Myocarditis: A Report of the American College of Cardiology Solution Set Oversight Committee. J Am Coll Cardiol. 2024 Dec 10:S0735-1097(24)10040-X. doi: 10.1016/j.jacc.2024.10.080. Epub ahead of print. PMID: 39665703
