Relationship Between Pericoronary Fat Attenuation Index(FAI) And Coronary Atherosclerosis And Plaque Properties

Objective: Coronary artery inflammation is the main factor to promote the occurrence of coronary atherosclerosis and vulnerable plaque rupture.Recently,it has been proposed that the measurement of pericoronary fat attenuation index(FAI)on CCTA is an effective way to detect coronary artery inflammation in the early stage.The main purpose of this study is to find out the relationship between the proximal 40 mm FAI of the three branches of coronary artery based on CCTA and the occurrence and properties of atherosclerotic plaque in coronary artery.Materials and methods:We retrospectively reviewed medical records and images from598 patients who underwent CCTA examination with Revolution CT from March 2017 to April 2019.The exclusion criteria were as follows: previous history of CABG and PCI;poor image quality of CCTA;patients with infectious diseases,valvular heart disease,congenital coronary artery malformations or arrhythmias;images could not be recognized by CCTAAI-assisted diagnosis system.Finally,the CCTA images of 264 patients were used to automatically measure the FAI value of the adipose tissuesurround the 40 mm in the proximal three branches of the coronary artery using the AI-assisted diagnosis system(Coronary Doc,Shukun Technology).The differences of pericoronary FAI in the proximal 40 mm of coronary artery were compared according to whether there were plaques(0: no plaques,1: plaques),lumen stenosis(< 50%,≥ 50%)and plaque characteristics(calcified,non-calcified,mixed plaques)in the analyzed segments.Linear regression analysis was used to calculate the correlation between pericoronary FAI in the proximal 40 mm of coronary artery and plaque properties(characteristics,area and number of the plaque,degree of lumen stenosis)and lesion locations.Results: 774 coronary arteries of 264 patients were included in pericoronary FAI analysis.The FAI value around the coronary artery with plaque(-79.22 ±8.47HU)in the proximal 40 mm segments of coronary artery was significantly higher than that in the group without plaque(-82.23 ±8.34HU),and the difference was statistically significant(p< 0.001).After the analysis of the three major branches of the coronary artery,it was also found that the FAI around the coronary artery in the plaque group was higher than that in the non-plaque group,and the difference was statistically significant.In patients with coronary atherosclerosis,the pericoronary FAI of patients with non-calcified plaque(-76.59 ±8.21HU)was significantly higher than that of patients with calcified plaque(-81.01 ±8.67HU),and the difference was statistically significant(p= 0.001).Multiple linear regression analysis showed that the plaque characteristics,lesion locations and lesion area in the proximal 40 mm segment of the three branches of the coronary artery were all correlated with the pericoronary FAI value around the corresponding segment(p<0.05).Conclusion:Pericoronary FAI represents a new monitoring method of coronary artery inflammation.This study found that the presence of atherosclerotic plaques in the proximal 40 mm of the three major branches of the coronary artery would significantly affect the pericoronary FAI,and the properties of the plaque,such as the plaque characteristics,lesion locations and lesion area,were significantly correlated with the increase of pericoronary FAI in the proximal 40 mmsegment of the three branches of the coronary artery.