POS0342 DISCRIMINANT VALUE OF ULTRASOUND OF THE WALL OF LARGE VESSELS IN THE DIAGNOSIS OF GIANT CELL ARTERITIS
Authors: I. González-Mazón, E. Fernández-Fernández, I. Monjo, E. De Miguel
Journal: Annals of the Rheumatic Diseases (2021)

Background: The EULAR recommendations for the use of imaging in large vessel vasculitis in clinical practice suggest the performance of diagnostic imaging tests in all patients with suspected GCA and ultrasound is the recommended first-line test in patients with suspected cranial GCA (c-GCA) 1 . However, a priority imaging modality has not been established in cases of suspected GCA involving large vessels (LV-GCA). Since patients with LV-GCA often undergo extensive screening programs for suspected infection or malignancy before the diagnosis of GCA is established, our knowledge in this field needs to be improved. Objectives: The aim of this study is to investigate the wall affectation of vasculitis of the proximal arm and neck arteries in patients with suspected GCA, polymyalgia rheumatica (PMR), atherosclerosis and non-GCA patients. Methods: Retrospective available ultrasound examination from all the patients referred to our GCA fast-track clinic in the last three years were collected. All patients had ultrasound of cranial and large vessel examination (axillary, subclavian and carotid arteries). GCA diagnosis was confirmed by the doctor after a follow-up between six months to three years. Every patient had videos and pictures of every referred vessel. Examination was performed by two rheumatologists with long experience in GCA ultrasound from the same Rheumatology Department with a Esaote Mylab Twice with probe of 13 MHz (2017-2019) and a Esaote Mylab X8plus with a probe of 15 MHz (2019-2020). IMT and hypoechoic halo measures were taken. Results: We analyzed 300 examinations and selected 196 baseline cases of four different pathologies (29 PMR, 40 atherosclerosis, 71 GCA of which 14 LV-GCA without cranial involvement and 56 non-GCA non-PMR controls). Intima-media thickness (IMT) with the statistical significance between different diseases and controls are showed in the Table 1. Table 1. Ultrasound IMT and halo measures in large vessels of different diseases and controls Non-GCA n=56 GCA n=71 Atherosclerosis n=40 PMR n=29 LV-GCA n=14 Axillary right # * 0.67±.19 0.95±0.30 0.70±0.18 0.65±0.13 1.03±0.33 Axillary left # ** 0.61±0.12 0.92±0.29 0.72±0.19 0.66±0.13 0.99±0.25 Subclavian right # * 0.70±0.15 1.00±0.31 0.86±0.29 0.70±0.20 1.09±0.36 Subclavian left # * 0.62±0.14 0.95±0.27 0.70±0.14 0.64±0.18 1.05±0.25 CCD right # 0.79±0.22 0.97±0.26 1.01±0.30 0.81±0.10 0.91±0.29 CCD left # 0.81±0.16 0.99±0.22 0.98±0.32 0.82±0.20 0.97±0.17 GCA= Giant cell arteritis (cranial, large vessel and mixed forms); Non-GCA = Patients suspected but not confirmed as GCA; Atherosclerosis = patients with high arteriosclerosis risk without suspected GCA; PMR = Patients with polymyalgia rheumatica without GCA; LV-GCA= Large vessel vasculitis GCA without cranial involvement. # p&lt;0.01 GCA vs non-GCA and GCA vs PMR * p&lt;0.01 GCA vs Atherosclerosis; ** p&lt;0.05 GCA vs Atherosclerosis Conclusion: GCA ultrasound of large vessels shows significant differences with other diseases. The differences seem to support the use of ultrasound in the fast-track clinic of GCA not only in c-GCA but also in LV-GCA. References: [1]Dejaco C et al. EULAR recommendations for the use of imaging in large vessel vasculitis in clinical practice. Ann Rheum Dis. 2018 May;77(5):636-643. doi: 10.1136/annrheumdis-2017-212649. Epub 2018 Jan 22. PMID: 29358285. Disclosure of Interests: Iñigo González-Mazón: None declared, Elisa Fernández-Fernández: None declared, Irene Monjo Speakers bureau: Roche, Novartis, UCB, Gedeon Richter, Consultant of: Roche, Eugenio de Miguel Speakers bureau: AbbVie, Novartis, Pfizer, MSD, BMS, UCB, Roche, Grunental, Janssen, Sanofi., Paid instructor for: Janssen, Novartis, Roche, Consultant of: AbbVie, Novartis, Pfizer, Galapagos, Grant/research support from: Abbvie, Novartis, Pfizer