Current Status and Future of Coronary CT: An Interview With Leslee J. Shaw, PhD, FACC

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Leslee J. Shaw, PhD, FACC, is an outcome research scientist and professor of medicine and radiology at Weill Cornell Medical College in New York.

She is the immediate past president of the Society for Cardiovascular Computed Tomography, past president of the American Society of Nuclear Cardiology, past chair of the Cardiac Imaging Committee for the Council of Clinical Cardiology of American Heart Association, and is on the Imaging Council for the ACC. In addition, Shaw sits on editorial board of several journals and is an executive editor of JACC: Cardiovascular Imaging.

In an interview conducted by Parham Eshtehardi, MD, Fellow in Training at Emory University School of Medicine, Shaw discusses the current status and future of coronary CT.

Eshtehardi: Let’s talk about the fastest growing non-invasive coronary imaging modality: coronary CT. Coronary CT angiogram (CTA) is distinct among non-invasive tests because it provides valuable anatomical information including presence, extent and severity of atherosclerosis, as well as plaque composition.

While coronary CTA does not provide any information on ischemia burden, proponents of coronary CTA believe that it improves important patient outcome compared with functional testing. As a lead researcher in several ischemia studies, what do you think is more important: anatomy or ischemia?

Shaw: CT is also capable of measuring rest and stress myocardial perfusion imaging as well as FFR-CT (CT-derived fractional flow reserve), which provide functional assessment of coronary disease. I have a very different view that does not pick one vs. the other and believe that both functional and anatomic testing are important for clinical practice use. It is simply what you start with and when you choose to bring in the second line test of anatomy or ischemia.

With all the available trials, CTA evidence is strong and should warrant its expanded use as a frontline procedure. Then, consider adding ischemia testing for patients with intermediate stenosis or assess the functional significance of a high-grade lesion.

Conversely, CTA should be considered as an add-on procedure for patients with ischemia on stress testing. It is less expensive and very accurate at defining the extent and severity of obstructive coronary artery disease. Moreover, the correlation between ischemia and atherosclerotic plaque – even in the setting of mild obstructive stenosis – can be an important means to define ischemic and anatomic risk.

Eshtehardi: FFR-CT adds physiologic assessment to anatomical data of coronary CTA. Do you think FFR-CT overcomes the limitations of coronary CTA in evaluation of ischemia?

Shaw: I don’t think that the data are ready for FFR-CT. While FFR-CT shows promise, it still needs work before it can be reliably applied in everyday clinical decision making. Data suggest that FFR-CT is less concordant with values from 0.70 to 0.80, which is an important range for decisions regarding percutaneous coronary interventions. We will likely see important trials and registries in the next few years that will help clarify the role of FFR-CT.

Eshtehardi: What are the current barriers for the widespread use of coronary CTA in clinical practice?

Shaw: Largely, the barriers are reimbursement. However, we are seeing that change and have witnessed major payers and radiology benefits managers develop more robust policies for CTA coverage over the past 12 months, especially as a front-line procedure.

Eshtehardi: Despite a strong body of evidence, ease of use and low cost, coronary artery calcium (CAC) scoring has not become a routine test for risk-stratification. Do you think there is a future for CAC evaluation?

Shaw: Absolutely. There is a strong push to add CAC and recent data from the PROMISE and CRESCENT trials explain how valuable it is in discerning patient risk. I would only support that discerning CAC provides important information about the presence of atherosclerosis and helps guide preventive strategies.

Eshtehardi: What are the benefits of social media for clinicians and researchers?

Shaw: It is important to guide folks who are not in imaging towards what is important. Since physicians and health care professionals are so busy, the discussion of important trends and scientific achievements in imaging provide an important means to educate our community as to what is “hot” and “trending” in cardiovascular imaging.

Eshtehardi: You recently accepted a new position at Cornell and moved from Atlanta to New York City. How do you like the change?

Shaw: New York is such a vibrant city with so many amazing medical schools. I collaborated heavily with people at Cornell and it seemed natural to move here and formally work with my longstanding colleagues.

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This interview was conducted by Parham Eshtehardi, MD, Fellow in Training at Emory University School of Medicine in Atlanta, GA.