OP5 Pericoronary adipose tissue density is greater in takayasu arteritis than atherosclerosis and is associated with coronary arterial inflammation measured by 68Ga-DOTATATE PET

Introduction Pericoronary adipose tissue (PCAT) density is associated with vascular inflammation, but its nature is not fully understood. We compared PCAT density with clinical and molecular imaging markers of inflammation. Methods PCAT density was quantified in patients with Takayasu arteritis (TAK), coronary artery disease (CAD), and age and gender-matched healthy controls from cardiac CT images using semi-automated software (Autoplaque). In TAK patients, PCAT density was also compared to the Indian Takayasu Clinical Activity Score (ITAS). In CAD patients, PCAT density was compared to maximum tissue-to-blood ratio (TBRmax) from motion-corrected 68Ga-DOTATATE PET, using image registration software (FusionQuant), and aortic 18F-fluorodeoxyglucose (FDG) PET. Imaging was acquired during clinical care or prior research. 68Ga-DOTATATE is an experimental marker of vascular inflammation that binds macrophage somatostatin receptor-2. Results 60 patients were included (TAK, n=20; CAD, n=20; healthy, n=20). Mean PCAT density varied significantly among the three groups (TAK: -74.00 ±SD 11.92 Hounsfield unit [HU]; CAD: -80.39 ±SD 10.9 HU; healthy controls: -83.85 ±SD 10.07 HU; p Conclusion PCAT density could be a useful, non-PET marker of coronary arterial inflammation and disease activity in both TAK and CAD patients.