Abstract 18320: Vessel-Specific Coronary Inflammation Quantified Using Perivascular Fat Attenuation Index Score on CCTA Detects the Vulnerable Coronary Artery and Predicts Acute Plaque Events

Abstract

Background: Coronary artery inflammation can be detected non-invasively on routinely performed coronary computed tomography angiograms (CCTA) by measuring the 3D changes of perivascular adipose tissue attenuation. Fat attenuation index (FAI) Score is the corrected metric of coronary inflammation measured in any of the 3 coronary arteries, and predicts acute myocardial infarction (AMI). Although FAI score is able to detect the vulnerable patient, it is unclear whether it can be used to detect the vulnerable artery in advance of an acute event. Aim: To evaluate the ability of FAI Score to detect the vulnerable coronary artery in patients undergoing CCTA for investigation of chest pain. Methods: Consecutive patients (n = 3,393, mean age 61±15, 57% male) from two UK hospitals in the Oxford Risk Factors and Non Invasive Imaging (ORFAN) study underwent CCTA between 2010-2018 for suspected coronary artery disease (CAD), and were followed up prospectively for a median of 7.7 years. AMI events were recorded via nationwide screening and the culprit vessel was identified based on the target lesion in percutaneous coronary intervention (PCI). FAI score was generated with CaRi-Heart® device. Results: A total of 296 AMI events occurred during the follow up period and 176 patients underwent PCI (59 attributed to the right coronary artery (RCA), and 93 to left anterior descending artery (LAD)). Patients with high FAI score in the LAD had 2 times higher risk for AMI in the LAD (Fig. A), but not in the RCA (HR 1.73 95% CI 0.96-3.08, p=0.07). Similarly, patients with high FAI score in the RCA had 1.9 times higher risk for AMI in the RCA (Fig. B), and modestly elevated risk for an AMI from the LAD. (HR 1.62, 95% CI 1.02-2.59, p=0.04) Conclusion: Vessel-specific FAI score predicts AMI caused by a culprit lesion in the corresponding coronary artery. The ability of FAI score to identify the vulnerable artery before it gives a plaque rupture event may be useful in planning targeted therapeutic interventions.