Abstract 10068: High Pericoronary Adipose Tissue Attenuation on Coronary Computed Tomography Angiography Predicts Cardiovascular Events in Patients Without Obstructive Coronary Artery Disease

Introduction: Patients without obstructive coronary artery disease (CAD) have an increased risk of major adverse coronary events compared to patients with no coronary artery stenosis. However, risk stratification among patients without obstructive CAD has not been established. Hypothesis: This study was aimed to investigate whether pericoronary adipose tissue attenuation (PCATA) on coronary computed tomography angiography (CCTA), a novel imaging biomarker of pericoronary inflammation, is a useful predictor for cardiovascular events in patients without obstructive CAD. Methods: A total of 1183 patients without obstructive CAD undergoing clinically indicated CCTA in our institute from August 2011 and December 2016 were enrolled. Obstructive CAD was defined as luminal narrowing of ≧50% in any coronary artery. We also examined PCATA and high-risk plaque features on CCTA as well as coronary artery calcium score and pericardial fat volume. PCATA in Hounsfield units (HU) was assessed at proximal 40-mm segments of all 3 major coronary arteries. The outcome was composite cardiovascular events including cardiovascular death, acute coronary syndrome, and late coronary revascularization. Results: During a median follow-up of 23.0 months, 32 cardiovascular events were observed. Left anterior descending artery (LAD)-PCATA in patients with cardiovascular events was significantly higher than that in patients without (-64.0 ± 6.0 HU vs -66.9 ± 7.3 HU, p=0.012), whereas right coronary artery- and left circumflex artery-PCATA were not. High LAD-PCATA was significantly associated with cardiovascular events in a model that included traditional risk factors, coronary artery calcium score and adverse CTA findings, such as degree of stenosis and high-risk plaque (HR; 1.467, 95%CI; 1.03-2.09, p = 0.033). Finally, incremental prognostic value of PCATA was evaluated. After adding LAD-PCATA to a model including traditional risk factors and the adverse CTA findings, global chi-square values increased significantly from 33.0 to 37.5 (p = 0.032). Conclusions: High LAD-PCATA has incremental prognostic value over conventional risk factors and CTA findings in patients without obstructive CAD.