CT procedure shown to reduce need for invasive cardiac testing
Scientists may have found an effective way to identify patients with coronary artery blockage or narrowing using a novel form of a CT scan that can potentially tell when patients are in need of a revascularization procedure. The findings are published in Radiology: Cardiothoracic Imaging. [1]
Traditionally, invasive procedures, such as coronary angiography, are used to image vessels and assess blockage. However, CT-fractional flow reserve (CT-FFR) is able to safely model a patient’s coronary blood flow using coronary CT angiography (CTA) of the heart, combined with AI to compute fluid dynamics.
Coronary CTA is the first step in the process, but used alone it has its limitations. The procedure allows providers to see and rank the degree of vessel blockage, but the study authors wrote it isn’t sufficient to predict the amount of blood flow in the vessel. To do that, a patient typically needs an invasive test.
“In patients with moderate narrowing or blockage of the arteries, there can be ambiguity about who would benefit from invasive testing and revascularization procedures,” the study’s lead author Mangun Kaur Randhawa, MD, Department of Radiology at Massachusetts General Hospital, said in a statement. “CT-FFR helps us identify and select those patients who are most likely to benefit.”
To assess how well CT-FFR can improve the measurement of artery blockage, Randhawa’s research team conducted a retrospective study of patients who underwent coronary CTA at Massachusetts General Hospital between August 2020 and August 2021.
Of the 2,985 study-eligible patients who underwent coronary CTA, 292 were referred for CT-FFR analysis. Of the cohort, eight exams were excluded, leaving a study group of 284. Reviewing the results of the CT-FFR, Randhawa and her team found that patients with significantly reduced blood flow, as seen on a coronary CTA, had lower rates of invasive coronary angiography, dropping to 25.5% from 74.5% for patients who did not undergo CT-FFR. Subsequent percutaneous coronary interventions were also reduced to 21.1% vs. 78.9%.
In simpler terms, patients shown to have significant blockage on a coronary CTA who would typically then undergo an invasive procedure to gather more details were able to avoid those procedures, thanks to CT-FFR.
“CT-FFR helps us identify patients who would most benefit from undergoing invasive procedures and to defer stenting or surgical treatment in patients who likely won’t,” study senior author Brian B. Ghoshhajra, MD, Massachusetts General Hospital, said in the statement, adding that CT-FFR, while it should be used selectively, seemed to work for the majority of patient cases by measuring significant coronary artery narrowing or blockages without compromising safety.
“When you objectively measure coronary artery flow with CT-FFR, you induce fewer patients to be further investigated and treated, because you tend to treat not just what the eyeball sees, but what the physiology supports,” Ghoshhajra concluded.
The full study is available at the link below.