A new study shows that a non-invasive imaging test can help identify patients with coronary artery blockage or stenosis who require revascularization. The findings were published as a special report. Radiology: Cardiothoracic imagingJournal of the Radiological Society of North America (RSNA).

Doctors use coronary CT angiography (CTA) to diagnose narrowing or blockage in the heart’s arteries. The CTA test gives a score of mild (0-1), moderate (2-3), or severe (4-5). Patients with a score above 3 usually require treatment and may benefit from stents or surgery to restore blood flow to the heart (revascularization).

CTA shows the extent of blood vessel blockage. However, the degree of occlusion does not always reliably predict blood flow within a vessel. ”

Mangun Kaur Randhawa, MD, Postdoctoral Fellow, Department of Radiology, Massachusetts General Hospital (MGH), Boston

Physicians have traditionally relied on an invasive procedure known as invasive coronary angiography to image blood vessels, but more recently, flow reserve ratio (ratio We are adding other invasive tests such as FFR). CT-FFR is a relatively new alternative that uses CTA images of the heart, AI algorithms, and/or computational fluid dynamics to non-invasively model a patient’s coronary blood flow.

To assess the impact of selective use of CT-FFR on clinical outcomes, Dr. Randhawa’s research team studied patients who underwent coronary CTA at MGH between August 2020 and August 2021. A retrospective study was conducted.

During the study period, 3,098 patients underwent coronary CTA. Of these, 113 coronary artery bypass graft patients were excluded. Of the remaining 2,985 patients, 292 (9.7%) were referred for CT-FFR analysis, and eight of these tests were excluded, resulting in a final study group of 284 patients.

As expected, most of the referrals to CT-FFR were patients with a score of 3 or higher. CT-FFR was requested in the majority (73.5%) of patients with score 3 (moderate stenosis/occlusion).

“For patients with moderate arterial narrowing or occlusion, it can be unclear who will benefit from invasive testing or revascularization,” Dr. Randhawa said. “CT-FFR helps identify and select patients who will benefit most.”

Of the 284 patients, 160 (56.3%) had negative CT-FFR results > 0.80, 88 patients (30.9%) had clearly positive (abnormal) results ≤0.75, and the remaining 36 had negative CT-FFR results > 0.80. patients (12.6%) with borderline results between 0.76 and 0.80.

Patients with significant stenosis/occlusion on coronary CTA who underwent CT-FFR were more likely to undergo invasive coronary angiography (25.5% vs. 74.5%) and subsequent percutaneous coronary intervention than patients who did not undergo CT-FFR. The rate of intervention (21.1% vs. 78.9%) was lower. CT-FFR.

“CT-FFR can help identify patients who would benefit most from undergoing invasive procedures and defer stent placement or surgical treatment for those who are unlikely to benefit,” said the lead author. said Brian B. Goshajila, MD, MBA, vice chair of the Department of Surgery and Academic Affairs. Director of Cardiovascular Imaging at MGH. “We found that CT-FFR ‘improves’ over CT, but its benefits are greatest when used selectively.”

Dr. Ghoshhajra added that CT-FFR analysis was successful in the majority of patients, regardless of challenging factors such as elevated or irregular heart rate or obesity.

“When we measure coronary flow objectively with CT-FFR, we tend to treat what the physiology supports, not just what the eye sees, reducing the number of patients who undergo further investigation and treatment.” he said.

The researchers said that the results of this study demonstrate the utility of CT-FFR in clinical practice when used selectively, allowing invasive procedures in patients with significant coronary artery stenosis or occlusion without compromising safety. He emphasized the possibility of reducing the frequency of