VIDEO: Use of CT to assess coronary plaques
Leslee Shaw, PhD, FACC, MASNC, FAHA, FSCCT, clinical scientist and director of The Blavatnik Family Women’s Health Research Institute, Mount Sinai Hospital, New York, and former president of both the Society of Cardiovascular Computed Tomography (SCCT) and the American Society of Nuclear Cardiology (ASNC), explains how cardiac computed tomography (CT) can be used to assess coronary plaques.
CT was highly recommended in the recent 2021 chest pain evaluation guidelines being elevated to a 1A recommended front-line imaging modality. Cardiac CT was already seeing wider usage prior to the guidelines, but now many hospitals are looking at using a CT-first approach to cardiac assessments. CT plaque imaging will likely be another next step in CTA advancements to be adopted for general cardiac assessments in the next few years.
The CT images are created based on the density of the materials the photons pass through, known as Hounsfield units (HU). This measure can help determine the density of plaque composition to assess if it is calcified, fibrotic or lipid core. This can assess risks of future acute coronary syndromes (ACS). It is also possible to monitor the plaque progression, or regression, based on drug therapy. Many cardiac CT experts predict low-dose CTA will play a key role in prevention efforts in a few years by showing patients the impact of lifestyle changes and stain therapies on serial scans over time.
CT calcium scoring is now a standard-or-care and is a type of plaque assessment imaging. These scans are often used as a screening tool for assessing myocardial infarction risks in patients and to determine if a patient should go on statins. Coronary artery calcium (CAC) uses the Agatston scoring system that calculates the amount of calcified plaque in the coronary arteries to offer a risk assessment for the likelihood of future cardiac events.
CT assessments for soft plaques are more challenging, sometimes being limited by the image quality and the resolution of the scans. Automated assessment software can help determine the HU values for various plaques, which otherwise can be difficult to interpret. Artificial intelligence (AI) applications have also been developed to automatically analysis the soft plaques and speed these assessments.
Newer CT scanner and post-processing advanced visualization technology will likely advance plaque assessments toward of more commonly used standard of care. Technologies to watch in this area include photon-counting CT scanners offering higher resolution imaging, and the development of perivascular fat attenuation index as a metric of coronary inflammation, which will show areas of vulnerable plaques that cause heart attacks.
Shaw spoke with Cardiovascular Business at the American College of Cardiology (ACC) 2022 meeting.
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Dave Fornell has covered healthcare for more than 17 years, with a focus in cardiology and radiology. Fornell is a 5-time winner of a Jesse H. Neal Award, the most prestigious editorial honors in the field of specialized journalism. The wins included best technical content, best use of social media and best COVID-19 coverage. Fornell was also a three-time Neal finalist for best range of work by a single author. He produces more than 100 editorial videos each year, most of them interviews with key opinion leaders in medicine. He also writes technical articles, covers key trends, conducts video hospital site visits, and is very involved with social media. E-mail: dfornell@innovatehealthcare.com