Detecting coronary inflammation on CT imaging could reshape preventive cardiology
New technology that directly visualizes inflammation in a patient's coronary arteries could potentially transform the preventive cardiology landscape. It can evaluate a patient's risk of a heart attack in a way that goes beyond what we learn from traditional cholesterol readings.
Researchers at Oxford University developed the novel imaging technology, which detects coronary inflammation using coronary computed tomography angiography (CCTA) scans and artificial intelligence (AI) to show inflammation in the perivascular fat surrounding the vessels. It is now being commercialized by Caristo and pending U.S. Food and Drug Administration (FDA) final review.
"It has always been the holy grail of cardiovascular prevention to be able to pick up coronary inflammation, because if you know which artery is inflamed and which patient needs treatments to prevent heart attacks. Up until now, we had only simply biomarkers like high sensitivity C-reactive protein (CRP), which are nonspecific. So we have developed a technology the last few years that allows you to measure coronary inflammation by analyzing the fat that surrounds arteries," explained by Charalambos Antoniades, MD, the British Heart Foundation Chair of Cardiovascular Medicine at the University of Oxford. He spoke with Cardiovascular Business about the technology at the American Heart Association (AHA) 2024 meeting, where he presented data on it at multiple sessions.
How perivascular fat attenuation imaging works
When an artery is inflamed, it secretes inflammatory molecules into the perivascular fat that activate lipolysis and change the composition of the fat surrounding the artery.
"This is something that you can visualize and quantify from routine CCTA. We can tell how inflamed your coronary artery is just by looking at these scans," Antoniades said.
He describes the CT images essentially as echos of inflammation from the vessel, since there is no way currently to directly measure or visualize vascular inflammation. The AI is able to assess these changes in the fat with a millimeter-by-millimeter assessment on contrast CT scans. The AI then calculates a perivascular fat attenuation index (FAI) score, a reproducible risk assessment for coronary events based on inflammation levels.
This technology was one of the key innovations cited by numerous CCTA experts at the Society of Cardiovascular Computed Tomography (SCCT) over the past several years that could be a potential paradigm shift for how patients are evaluated for coronary risk.
CCTA inflammation imaging may change how patients are assessed
For decades, inflammation has been recognized as a key driver of cardiovascular disease. However, the ability to accurately measure inflammation within coronary arteries remained elusive. Traditional biomarkers like high-sensitivity C-reactive protein (hs-CRP) could detect systemic inflammation, but lacked specificity for coronary vessels.
The Caristo technology has already demonstrated its potential in clinical trials. It not only detects coronary implantation, but also can track regression after a patient is treated with anti-inflammatory agents such as statins and biologics. The ability to track these changes in real time may revolutionize how physicians manage cardiovascular risk, or help determine which drugs are working.
The increased interest in coronary inflammation has surged following the FDA's approval of colchicine for cardiovascular disease treatment. Until recently, there were limited therapeutic options to target inflammation in coronary arteries. With new pharmacologic interventions emerging and AI-driven advancements in CT imaging, the ability to assess and treat inflammation has become more feasible and impactful.
“This technology fits perfectly into the evolving landscape of cardiovascular prevention,” Antoniades noted. “Unlike plasma biomarkers that indicate general inflammation, our imaging method identifies inflammation specifically in the coronary arteries, pinpointing which artery—or even which plaque—poses the highest risk.”
Inflammation has been the missing link in heart attack risk assessments
Not all patients with coronary plaques or high cholesterol will have a heart attack. In fact, a large number of heart attacks occur in patients without obstructive coronary artery disease (CAD). Often a patient's first healthcare evaluation for heart disease is when they present to the hospital with chest pain.
ORFAN, late-breaking study using the Caristo technology Antoniades presented at AHA 2023 and published in 2024, showed patients without obstructive CAD were two times as likely to have heart attacks.(1) Out of the 40,000 patients tracked in the study, only 18% of cardiac events occurred in patients with obstructive CAD, showing inflammation was a key factor.
Newer CCTA AI technologies from vendors like Cleerly and Heartflow can already identify existing soft plaques, detail their composition and accurately quantify and track the plaques over time. However, plaque is stable unless it has the addition of inflammation, which makes them unstable and vulnerable to plaque rupture.
"Another important aspect of this is that by applying this kind of approach, you can identify coronary arteries which are inflamed before they even develop the plaque. Or you can find arteries that have minor plaques which are very inflamed, and they may cause a heart attack before you even see a large plaque," Antoniades explained.
He said this new information could make a major impact in preventive cardiology going forward.
"This AI technology takes into account plaque inflammation, the risk factors of the patient, and it calculates the absolute risk for a fatal cardiac event over the next decade. And then from the moment you have that number, the guidelines tell you exactly what to do. This is exactly the beauty of this AI technology," Antoniades said.
CT calcium scoring exams have been used for assessing coronary artery disease risk for several years, but it is falling out of favor with many cardiology experts in favor of soft plaque analysis. This is mainly due to calcified plaques being stable and not the primary cause for alarm. CCTA experts say the soft plaques that are not seen on calcium scoring scans are the real problem. And according to Antoniades, the addition of inflammation information will allow specialists to pinpoint which soft plaques to watch, and which patients need earlier or more intensive medication interventions.
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