VIDEO: Cardiac CT as a front-line chest pain exam in the ED
Harold Litt, MD, PhD, division chief, cardiothoracic imaging, director, Center for Advanced CT Imaging Sciences, and professor of radiology, Perelman School of Medicine of the University of Pennsylvania, explains the use of cardiac computed tomography (CT) as a primary imaging exam for patients with chest pain at his emergency department over the past decade. He also said use of CT has increased at his center this past year since the adoption of the new chest pain guidelines
Litt was the principle investigator of the ACRIN PA 4005 trial about a decade ago, the first large-scale trial powered to assess the use of noninvasive cardiovascular CT angiography (CCTA) in chest pain patients presenting to emergency departments (ED). The data found CCTA could be used a s a rapid rule out test for coronary involvement, or it could show blockages the CT imaging.
Several more trials over the past decade created enough clinical data to raise CCTA to a level A1 recommendation for chest pain imaging in the 2021 ACC/AHA Chest Pain Guidelines. The guidelines now call for the use of CT as a front line imaging modality in certain instances, especially in patients with no prior history of coronary artery disease.
"We have believed for a long time that CT is the best first test for most patients that are coming to the emergency department, particularly low and intermediate risk patients," Litt explained. "What we see in the new guidelines is pushing that up a bit into higher-risk patients."
At the University of Pennsylvania, he said they have combined CCTA with the use of high sensitivity troponin blood tests to speed diagnosis of ED chest pain patients.
"Earlier this year, we put together a task force made up of the high sensitivity troponin advocates and the imaging advocates to decide what are we going to do with patients who come in and have a slightly elevated troponin, what should the first test be that we do. And the answer is almost always CT," Litt said.
He explained CT is a good first test in patients that are considered low-risk, but in patients with known coronary disease, these patients are better suited for functional testing.
"In the patients with known coronary disease, CT is just going to show you the disease you already know they have. So in those patients, we would want to go to a more functional test first, usually a PET scan or a stress echo," Litt explained.
The inclusion of CT in the new chest pain guidelines has had a noticeable impact on referrals for CCTA evaluations at his center.
"The new guidelines have definitely had an effect on out outpatient referrals," Litt said. "The community cardiologists, family medicine physicians, and internal medicine physicians have heard about the guidelines and are starting to think about CT more often and refer more patients with stable chest pain. Our volumes for stable chest pain patients have definitely gone up."
With increasing use of cardiac CT among referring physicians, the CAD-RADS scoring system plays an important role. Litt said this scale gives a standardized description of the severity of the disease present in the coronaries in an attempt to reduce variability between radiologists or cardiologists descriptions and make it easier for referring physicians to understand the reports.
Hear more of Litt's thoughts on cardiac CT in the VIDEO: The expanding role of cardiac CT in electrophysiology.