Expert clinical decision pathway details diagnosis, management of myocarditis
The guidance from the American College of Cardiology includes a five-step care pathway for myocarditis, including strategies for diagnosis, risk stratification, and surveillance, and proposes four new stages of disease classification.
Patients with clinically suspected myocarditis should be managed according to a five-step care pathway, according to a new expert clinical decision pathway from the American College of Cardiology.
The pathway was developed to inform care in adults with myocarditis and noted that optimal care should reflect the preferences of the managing clinician as well as the individual patient, with shared decision making whenever appropriate. The writing committee noted that the pathway is not intended to supersede good clinical judgment because many questions remain unanswered, especially regarding myocarditis care. “Given the complexity of this condition, team-based care is optimal and, depending upon the severity of the presentation, may include a broad array of specialists,” they wrote. The pathway was published Dec. 10 by JACC.
In step 1 of the care pathway, clinicians should recognize clinical syndromes compatible with acute myocarditis. Initial workup should include complete blood count with differential, biomarkers such as high-sensitivity cardiac troponins, electrocardiography, and echocardiography. Obstructive coronary artery disease should be excluded as clinically appropriate.
In step 2, clinicians should assess the need for hospitalization, urgent referral to an advanced heart failure center, and emergent arrhythmia management or circulatory support.
Step 3 involves ordering pivotal diagnostic tests, including cardiac magnetic resonance imaging (MRI) with T1 and T2 parametric mapping and endomyocardial biopsy.
Step 4 covers treatment and includes starting pharmacologic therapy, withdrawing an inciting agent when one is present, placing a temporary pacemaker or starting ventricular arrhythmia management if needed, and starting temporary circulatory support if needed. The small minority of patients who do not recover after initial treatment should receive a durable left ventricular assistive device or should be referred for transplant (if warranted and possible).
The statement notes that care does not end even if symptoms resolve within two to three weeks. Step 5, longitudinal surveillance, indicates that clinicians should monitor biomarkers and should order echocardiography and cardiac MRI with T1 and T2 parametric mapping. Outpatient genetic counseling and testing should be offered, and assessment for return to strenuous physical activity, including competitive sports, can be done three to six months after the initial diagnosis.
The document also proposed four stages of classification for myocarditis, where stage A refers to those having or exposed to risk factors, stage B includes those who are asymptomatic but have evidence of myocardial inflammation, stage C includes those with symptomatic myocarditis, and stage D includes those with advanced myocarditis (e.g., hemodynamic or electrical instability requiring intervention).
The pathway noted that more research is needed to define the trajectories of these four proposed stages, including evaluating risk for progression to chronic heart failure, determining rate of progression from stage A to higher stages, and pinpointing when stage D becomes irreversible. Additional areas for research include phenotyping, racial differences in mortality rates, social determinants of health, and access to and coverage of screening, evaluation, and care, the committee said.