Recommendations for multimodality cardiovascular imaging of patients with hypertrophic cardiomyopathy: An update from the American Society of Echocardiography (ASE) in collaboration with the American Society of Nuclear Cardiology, the Society of Cardiovascular Magnetic Resonance & the Society of Cardiovascular Computed Tomography

Recommendations for multimodality cardiovascular imaging of patients with hypertrophic cardiomyopathy: An update from the American Society of Echocardiography (ASE) in collaboration with the American Society of Nuclear Cardiology, the Society of Cardiovascular Magnetic Resonance & the Society of Cardiovascular Computed Tomography

REVIEWED BY | Susannah Mahar ASA SIG: Cardiac

REFERENCE | Authors: Abraham T, Armour AC, Desai MY, Dragulescu A, Gilliland Y, Lester SJ, Maldonado Y, Mohiddin S, Nagueh SF, Nieman K, Phelan D, Sperry BW, Woo A Journal: Journal of the American Society of Echocardiography 2022; June

WHY THE STUDY WAS PERFORMED AND WHAT THE STUDY FOUND

This article was written to review the evolution of multiple imaging techniques used to assess and differentiate hypertrophic cardiomyopathy from other causes of left ventricular hypertrophy (LVH). The article is composed of three sections. The first focuses on imaging, including echocardiography, cardiac magnetic resonance, cardiac computed tomography and cardiac nuclear imaging. The second section reviews the use of imaging for risk stratification and prognostication, and the final section discusses the role of multimodality imaging in common clinical scenarios. In conclusion, the article highlights the importance of using as many modalities as possible to evaluate, diagnose and guide treatment in patients with hypertrophic cardiomyopathy.

Initially, the article outlines the specific characteristics and symptoms of hypertrophic cardiomyopathy (HCM). It reviews the benefits and pitfalls of each technique and sums up how to differentiate HCM from other phenotypes including athletic remodelling, hypertension, inflammation and infiltration.

Echocardiography is the primary modality used for assessing the pattern of left ventricular hypertrophy. When the images are suboptimal, then ultrasound enhancing agents (UAEs) are recommended. Cardiac magnetic resonance (CMR) and cardiac computed tomography are also suggested due to their high spatial resolution. Cardiac resonance uses late gadolinium enhancement (LGE) with T1 and T2 mapping, which is beneficial in evaluating patients who have increased wall thickness.

Thorough assessment of the patient also includes looking for concomitant pathology such as aortic stenosis, subaortic membrane, apical aneurysm, thrombus and mid-cavity obstruction which can mimic hypertrophic cardiomyopathy.

The following assessments are also required:

• left ventricular systolic function

• diastolic function

• dynamic left ventricular outflow tract obstruction

• mitral valve anatomy.

Section two highlights the use of multimodality imaging to help with risk stratification and prognostication. Sudden cardiac death (SCD) is low in patients with hypertrophic cardiomyopathy. Currently, there is an algorithm that calculates the risk of sudden cardiac death (HCM-SCD score) based on age, maximal wall thickness, LA diameter and maximal left ventricular outflow tract gradient, but this article questions the sensitivity of the score and suggests including more imaging guidelines to direct treatment. Inclusion of the following parameters: apical aneurysm, late gadolinium enhancement (LGE) by CMR, LV systolic dysfunction and ischaemia are necessary to support treatment options such as implantable cardiac defibrillator (ICD) pacemakers and septal reduction therapy (SRT).

“Appropriate understanding and utilisation of multimodality imaging is fundamental to accurate diagnosis as well as longitudinal care of patients with HCM.”

The final section highlights the importance of multimodality imaging in common clinical scenarios such as chest pain and coronary artery disease. Myocardial perfusion imaging techniques such as positron emission topography (PET), cardiac computed tomographic angiography (CCTA) and cardiac magnetic resonance (CMR) are the preferred methods of investigation. The best noninvasive assessment of the coronary arteries is CCTA, and both PET and CMR are preferred techniques for stress perfusion. Echocardiography is used initially as a screening tool and for patients in the pre and postprocedural setting.

IN CONCLUSION THE RELEVANCE TO CLINICAL PRACTICE

Multimodality imaging plays a crucial role in the initial evaluation of patients with known or suspected hypertrophic cardiomyopathy. It is central to risk stratification for sudden cardiac death and can be used in common clinical settings such as chest pain and coronary artery disease. When performed by an experienced practitioner, and in conjunction with clinical findings, imaging can confirm or refute findings and guide relevant therapies.