The following are key points to remember from a state-of-the-art paper on current and evolving multimodality cardiac imaging in managing transthyretin amyloid cardiomyopathy:

1. Background: Amyloid transthyretin cardiomyopathy (ATTR-CM) is common and under-recognized. With newer targeted therapies available, early recognition and better characterization of this disease utilizing cardiac imaging is important.
2. Current European and US recommendations: For the diagnosis of ATTR-CM, a stepwise approach is recommended, which includes: 1) assessing for clinical, electrocardiographic, and echocardiographic features consistent with ATTR-CM among patients with heart failure and/or unexplained increase in left ventricular (LV) wall thickness; 2) evaluating for monoclonal proteins to rule out AL amyloidosis in addition to either simultaneous or possible downstream bone scintigraphy scanning for ATTR-CM; and 3) selecting additional testing, such as cardiac magnetic resonance imaging (CMR), endomyocardial or extracardiac biopsies, and genetic testing, to clarify or confirm the diagnosis.
3. Role of echocardiography: This imaging modality for assessment of cardiac amyloidosis is widely available, readily quantifies LV wall thickness/mass and chamber dimensions, assesses LV diastology, and assesses LV strain patterns. This modality does not directly assess myocardial tissue characteristics.
4. Role of nuclear imaging: The use of semi-quantitative bone scintigraphy scanning looking for amyloid deposits in the heart has become an important tool for diagnosing ATTR-CM with a high sensitivity and specificity. Quantitative single-photon emission computed tomography imaging is an emerging area of development, although it is not currently an established diagnostic tool for ATTR-CM.
5. Role of CMR: This modality uniquely can provide information on cardiac function and tissue characterization, helping to better diagnose cardiac amyloidosis and understand disease pathophysiology. Patterns of late gadolinium enhancement, myocardial nulling patterns, T1 mapping, and measured extracellular volume are particularly helpful in diagnosing cardiac amyloidosis. Emerging areas of investigation include assessment and use of LV strain, myocardial stiffness/elastography, spectroscopy, and diffusion tensor imaging,
6. Role of multimodality imaging for treatment and monitoring: Echocardiography is a simple and widely available modality for longitudinal follow-up. CMR offers detailed information on structure, function, and tissue characterization, but is less available and requires more center expertise. Either can be a tool for monitoring treatment response or to follow disease progression. Use of bone scintigraphy for monitoring is an emerging topic for discussion, though not well-established. New tracers for positron emission tomography scanning have shown the ability to quantify amyloid plaque burden and will need more evidence on how to best use in disease monitoring.
7. Future role of artificial intelligence: Machine learning algorithms may have a use in multimodality imaging for the diagnosis, characterization, and prognostication of cardiac amyloidosis. More work needs to validate this approach and integrate it into patient care.

Clinical Topics: Heart Failure and Cardiomyopathies, Noninvasive Imaging

Keywords: Cardiac Imaging Techniques, Cardiomyopathies

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