Pericoronary Adipose Tissue Attenuation Is Associated with High-Risk Plaque and Subsequent Acute Coronary Syndrome in Patients with Stable Coronary Artery Disease

Background: High-risk plaques (HRP) detected on coronary computed tomography angiography (CTA) confer an increased risk of acute coronary syndrome (ACS). Pericoronary adipose tissue attenuation (PCAT) is a novel biomarker of coronary inflammation. This study aimed to evaluate the association of PCAT with HRP and subsequent ACS development in patients with stable coronary artery disease (CAD). Methods: Patients with stable CAD who underwent coronary CTA from 2011 to 2016 and had available outcome data were included. We studied 41 patients with HRP propensity matched to 41 controls without HRP (60 ± 10 years, 67% males). PCAT was assessed using semi-automated software on a per-patient basis in the proximal right coronary artery (PCAT(RCA)) and a per-lesion basis (PCAT(Lesion)) around HRP in cases and the highest-grade stenosis lesions in controls. Results: PCAT(RCA) and PCAT(Lesion) were higher in HRP patients than controls (PCAT(RCA): −80.7 ± 6.50 HU vs. −84.2 ± 8.09 HU, p = 0.03; PCAT(Lesion): −79.6 ± 7.86 HU vs. −84.2 ± 10.3 HU, p = 0.04), and were also higher in men (PCAT(RCA): −80.5 ± 7.03 HU vs. −86.1 ± 7.08 HU, p < 0.001; PCAT(Lesion): −79.6 ± 9.06 HU vs. −85.2 ± 7.96 HU, p = 0.02). Median time to ACS was 1.9 years, within a median follow-up of 5.3 years. PCAT(RCA) alone was higher in HRP patients who subsequently presented with ACS (−76.8 ± 5.69 HU vs. −82.0 ± 6.32 HU, p = 0.03). In time-dependent analysis, ACS was associated with HRP and PCAT(RCA). Conclusions: PCAT attenuation is increased in stable CAD patients with HRP and is associated with subsequent ACS development. Further investigation is required to determine the clinical implications of these findings.