2024 Strategies and Criteria for the Diagnosis and Management of Myocarditis

Top 10 key takeaway points of the report of the American College of Cardiology Solution Set Oversight Committee for the diagnosis and management of myocarditis: 1. Be aware of the 3 classic presentations of myocarditis: chest pain, heart failure/shock, and/or symptoms related to arrhythmia (eg, presyncope or syncope), especially in a young person with the history of an antecedent viral infection, or other risk factors. 2. High-sensitivity cardiac troponin (hs-cTn) is a common diagnostic test in patients with suspected myocarditis; however, some patients with myocarditis will not have an elevated hs-cTn. 3. Cardiac magnetic resonance (CMR) imaging often allows the noninvasive diagnosis of stage B or symptomatic myocarditis. Endomyocardial biopsy is warranted to diagnose specific conditions that require etiology-directed therapies. 4. A novel 4-stage classification of myocarditis is proposed. Stage A refers to those having or being exposed to risk factors; stage B to those asymptomatic but with evidence of myocardial inflammation; stage C to those with symptomatic myocarditis; and stage D to those with advanced myocarditis (hemodynamic or electrical instability requiring intervention). 5. Research is needed to define the trajectories of the 4 stages of myocarditis and what explains the variable rates of progression and improvement among patients. 6. Risk stratification in patients with symptomatic myocarditis. 7. The follow-up of patients with myocarditis does not end after 2 to 3 weeks, even with resolution of symptoms. Two cardiac imaging studies (echocardiogram and/or a CMR) are advised during follow-up. 8. Given the increasing recognition of genetic predisposition to myocarditis, genetic counseling and testing is advised and discovery of a pathogenic variant should be followed by cascade screening of family members. 9. Safety for return to strenuous physical activity is guided by a follow-up CMR, 24-hour monitoring for arrhythmia, and exercise testing, typically 6 months, can be as early as 3 months after diagnosis. 10. Further research on a wide range of factors is needed. Source: https://www.jacc.org/