The Myocarditis Foundation is very excited to share this recently published article! After peer reviews, and endorsements by the Myocarditis Foundation, the Heart Failure Society of America (HFSA), and the International Society of Cardiomyopathies, Myocarditis, and Heart Failure, the complete article was recently published by Elsevier.
It was after the events of the recent COVID pandemic that myocarditis was identified as a high-priority topic by the American College of Cardiology’s (ACC’s) Science and Quality Committee and the Solution Set Oversight Committee. Subsequently, the Writing Committee of the ACC Expert Consensus Decision Pathway (ECDP) on Strategies and Criteria for the Diagnosis and Management of Myocarditis was convened.
Dr. Leslie Cooper, the Co-Founder of the Myocarditis Foundation, was key to the development of this and was a Vice-Chair on the Writing Committee for the paper.
After many months of collaboration by specialists from around the world, this expert consensus decision pathway was developed to share with the physicians who are not familiar with the disease, but who truly need to be aware of the potential diagnosis for their patients. It has been found that the earlier the diagnosis is made for patients, the better the outcome and recovery for them.
While the article is geared for physicians, the Myocarditis Foundation wanted the public community to understand the information as well. We have developed a simpler way to better understand the content for the lay person. This synopsis is meant for the public community and not meant to take away from the complete article. It is important to recognize that there is inadequate healthcare coverage for myocarditis, both for diagnostic care and post diagnosis care. There is also a great need for advocacy, health policy, and interventions for equity for a disease such as myocarditis, that requires advanced therapies when severe. This is a good start that will improve the knowledge base for healthcare providers.
Simplified Lay Person Synopsis:
Recognizing Presentations
- Classic Symptoms: Myocarditis typically presents as:
- Chest pain resembling a heart attack.
- Heart failure/shock with symptoms like breathlessness, fatigue, or swelling.
- Arrhythmias causing fainting (syncope) or palpitations.
- Historical Clues: Look for recent viral infections, family history of cardiomyopathy, or exposure to toxins that can trigger myocarditis.
- Clinician Awareness: Recognizing myocarditis early is crucial since it mimics other conditions like acute coronary syndrome.
Diagnostic Tools: High-Sensitivity Cardiac Troponin (hs-cTn)
- Role: hs-cTn detects myocardial injury. It is often elevated in myocarditis but not always.
- Challenges:
- Some patients show normal hs-cTn despite having myocarditis.
- There’s a need for research to confirm if very low hs-cTn levels can reliably rule out myocarditis.
- Future Potential: Serial hs-cTn measurements could help track disease progression and recovery.
CMR and EMB as Pivotal Tests
- Cardiac Magnetic Resonance Imaging (CMR):
- Utility: Non-invasive test to detect inflammation using T1/T2 mapping and gadolinium-enhanced imaging.
- Advantages: Identifies patterns specific to myocarditis and rules out coronary artery disease.
- Limitations: May be less effective in patients with arrhythmias or delayed imaging post-symptom onset.
- Endomyocardial Biopsy (EMB):
- Utility: Helps identify specific types of myocarditis (e.g., giant cell or eosinophilic) and underlying infections.
- Risks: Procedural complications, though rare in experienced centers.
- Indications: Recommended for patients with severe symptoms or those unresponsive to standard therapies.
4-Stage Classification of Myocarditis
- New Framework parallels heart failure staging:
- Stage A: At-risk individuals (e.g., those with viral infections, cardiotoxic exposure).
- Stage B: Asymptomatic myocardial inflammation detected through imaging or biomarkers.
- Stage C: Symptomatic myocarditis (e.g., heart failure, arrhythmias).
- Stage D: Advanced myocarditis requiring interventions like circulatory support or heart transplantation.
- Significance: This classification helps guide treatment and monitoring.
Research Gaps
- Progression and Recovery:
- Rates of progression from Stage A to C are unclear.
- Factors determining recovery or irreversibility of Stage D myocarditis are unknown.
- Chronic Heart Failure:
- Long-term risk of developing chronic HF after myocarditis needs further study.
Referral Criteria for Advanced Heart Failure Centers
- Indications for Referral:
- Severe left ventricular dysfunction.
- Hemodynamic instability (e.g., shock, arrhythmias).
- High risk of requiring mechanical support or transplantation.
- Multidisciplinary Care: Centers specialize in advanced diagnostics, biopsies, and interventions like left ventricular assist devices (LVADs).
Follow-Up Care
- Monitoring:
- Two imaging studies are recommended:
- An early echocardiogram (2-4 weeks post-diagnosis) to check for progression.
- A follow-up CMR at six months for detailed assessment.
- Biomarkers like hs-cTn can help track recovery.
- Two imaging studies are recommended:
- Long-Term Surveillance:
- Even asymptomatic patients need follow-ups to prevent relapse or chronic complications.
- Advocacy is needed for insurance coverage of repeat testing.
Genetic Counseling and Testing
- Importance:
- Some forms of myocarditis (e.g., familial or genetically predisposed) are linked to specific gene mutations.
- Identifying mutations allows screening and preventive care for family members.
- Cascade Screening:
- When a genetic predisposition is identified, family members can be tested to detect risks early.
Return to Physical Activity
- Strenuous Activity:
- Exercise can exacerbate inflammation, so activity is restricted until recovery is confirmed.
- Guidelines:
- CMR, arrhythmia monitoring (e.g., 24-hour Holter), and exercise tests are required to clear patients for strenuous activity.
- Athletes may resume competitive sports after 3-6 months if cleared by testing.
Future Research Needs
- Knowledge Gaps:
- Social determinants of health impacting disease outcomes.
- The psychological burden on patients and caregivers.
- Effectiveness of immunosuppressive therapies.
- Advanced imaging techniques to improve diagnosis.
- Registries: International collaboration to collect patient data could improve understanding of myocarditis.
Management Pathway Summary
- Initial Evaluation:
- ECG, biomarkers (e.g., hs-cTn), echocardiography, and ruling out coronary artery disease.
- Definitive Testing:
- Use CMR or EMB for confirmation based on symptoms and risk.
- Treatment:
- Initiate pharmacological and supportive therapy based on myocarditis stage and severity.
- Follow-Up:
- Monitor for symptom recurrence, imaging changes, and biomarkers.
- Physical Activity:
- Gradual return under supervision after diagnostic clearance.
Novel Contributions
- Updated Lake Louise Criteria for CMR: Highlights parametric T1 and T2 imaging to detect myocarditis-associated inflammation.
- Focus on Genetic Factors: Suggests genetic predisposition might contribute significantly to susceptibility.
