HOUSTON — Multimodal imaging is crucial for the diagnosis and care of patients with hypertrophic cardiomyopathy (HCM), according to new guidelines from the American Society of Echocardiography.
The recommendations were also endorsed by the American Society of Nuclear Cardiology, the Society for Cardiovascular Magnetic Resonance, and the Society of Cardiovascular Computed Tomography.
HCM is diagnosed by the presence of left ventricular hypertrophy without any other causes from cardiac, systemic, syndromic, or metabolic diseases. Symptoms can vary widely and include left ventricular outflow tract obstruction with or without significant mitral regurgitation, diastolic dysfunction with heart failure with preserved and heart failure with reduced ejection fraction, autonomic dysfunction, ischemia, and arrhythmias, according to an article in the Journal of the American Society of Echocardiography.1
“Appropriate understanding and utilization of multimodality imaging is fundamental to accurate diagnosis as well as longitudinal care of patients with HCM,” wrote the panel, which was chaired by Sherif F. Nagueh, MD, of Houston Methodist Hospital. Led by, “Resting and stress imaging provide comprehensive and complementary information to help clarify mechanism(s) responsible for symptoms such that appropriate and timely treatment strategies may be implemented.”
It added, “Advanced imaging is relied upon to guide certain treatment options, including septal reduction therapy and mitral valve repair. Using both clinical and imaging parameters, enhanced algorithms for sudden cardiac death risk stratification facilitate selection of HCM patients most likely to benefit from implantable cardioverter-defibrillators.”
The guidelines said echocardiography is the best initial imaging modality for HCM screening, along with clinical evaluation and ECG. They advised that screening frequency for asymptomatic family members of HCM patients depends on age, whether a pathogenic variant is identified and if there is early-onset disease.
Specifically, the guidance calls for screening every 1 to 2 years for children and adolescents from families with known pathogenic variants and/or early-onset disease. Without those conditions, children and adolescents should be screened every 2-3 years. In adults, screening is advised every 3-5 years, and at the onset of symptoms that indicate cardiac disease.
“All myocardial segments should be carefully examined for evidence of hypertrophy,” the panel emphasized. “CMR should be considered in patients with technically challenging echocardiograms, and in patients in whom abnormal electrocardiographic findings are present despite an apparently normal echocardiogram. There are several observational studies in patients who are genotype positive but who have not yet developed LV hypertrophy, noting the presence of crypts, increased ratio of LV wall thickness to LV end-diastolic dimension, increased ECV by CMR, and abnormal segmental systolic and diastolic function.”
The bottom line, according to the report, is that imaging “can confirm or refute the diagnosis.” The guidelines called for imaging to be performed at clinical sites/centers of excellence with experience in the diagnosis and management of HCM.
“Imaging is central to risk stratification for sudden cardiac death as well as the evaluation of patients with chest pain and possible CAD,” the authors pointed out. “Along with ECG, imaging with echocardiography and/or CMR is needed for screening. In addition, imaging can guide treatment for obstructive HCM, be it with negative inotropic drugs, septal reduction therapy, or TEER of the mitral valve.”
They added, “The imaging staff should have a clear understanding of the strengths and limitations of the different imaging modalities and the clinical implications of the findings ascertained by imaging. Importantly, the results should be communicated clearly with the clinical team taking care of the patient.”
- Nagueh SF, Phelan D, Abraham T, Armour A, Desai MY, Dragulescu A, Gilliland Y, Lester SJ, Maldonado Y, Mohiddin S, Nieman K, Sperry BW, Woo A. Recommendations for Multimodality Cardiovascular Imaging of Patients with Hypertrophic Cardiomyopathy: An Update from the American Society of Echocardiography, in Collaboration with the American Society of Nuclear Cardiology, the Society for Cardiovascular Magnetic Resonance, and the Society of Cardiovascular Computed Tomography. J Am Soc Echocardiogr. 2022 Jun;35(6):533-569. doi: 10.1016/j.echo.2022.03.012. PMID: 35659037.