Pericoronary fat attenuation index is associated with plaque parameters and stenosis severity in patients with acute coronary syndrome: a cross-sectional study

Abstract

Background: The pericoronary fat attenuation index (FAI) is a novel imaging biomarker of coronary inflammation, which is closely related to development and progression of coronary artery disease (CAD). However, there are limited reports on whether elevated pericoronary FAI values from coronary computed tomography angiography (CCTA) were associated with plaque parameters and coronary stenosis in patients with acute coronary syndrome (ACS). We aimed to assessed that FAI helps to identify high risk of CAD. Methods: The clinical diagnosis confirmed to the American Heart Association guidelines for ACS. The lesion-specific pericoronary FAI and plague parameters were measured using QAngioCT software. Using a Hounsfield unit (HU) of −70.1 as the threshold value, lesions with a lesion-specific pericoronary FAI value ≥−70.1 HU were allocated to the FAI-positive group and those with a FAI value <0.001). The area under the curve (AUC) of FAI in the diagnosis of vulnerable plagues was 0.810. Plaques were closer to the coronary ostium [3.32 (2.83, 4.29) vs. 4.17 (3.33, 4.95) cm, P<0.001] and more often located in the bifurcated segments of the vessels (50.65% vs. 32.43%, P=0.004) in the FAI-positive group than the FAI-negative group. The FAI-positive group also had a higher percentage of diameter stenosis than the FAI-negative group [80.00% (65.00%, 90.00%) vs. 60.00% (40.00%, 85.00%), P<0.001]. FAI values were higher in stenoses with a diameter ≥50% than stenoses with a diameter <50%. Conclusions: The FAI was identified as a novel imaging biomarker of coronary inflammation that is correlated with vulnerable plaque features and stenosis severity.