AXILLARY ARTERIES ULTRASOUND IN THE DIAGNOSIS OF GIANT CELL ARTERITIS WITH PREDOMINANTLY CRANIAL SYMPTOMS

J. Martinho, M. J. Sousa Bandeira, L. James, A. Verdiyeva, T. Fontes, A. R. Lopes, N. Khmelinskii, R. Luqmani, C. PonteCentro Hospitalar e Universitário de Lisboa Norte, Centro Académico de Medicina de Lisboa, Rheumatolgy Department, Lisbon, Portugal Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Centro Académico de Medicina de Lisboa, Unidade de Investigação em Reumatologia, Lisbon, Portugal University of Oxford, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Oxford, United Kingdom Hospital Divino Espírito Santo, Rheumatology Department, Açores, Portugal  Background Giant cell arteritis (GCA) is the most common form of primary systemic vasculitis in patients aged >50 years. It predominantly affects the cranial arteries; however, extra-cranial disease involving the aorta and its major branches can also be present. According to the 2018 EULAR recommendations, the ultrasound of temporal arteries (TAs), with or without axillary arteries (AXs), should be the first imaging modality performed in patients with suspected predominantly cranial GCA [1]. This recommendation reflects that the value of the AXs ultrasound in GCA diagnosis is still questionable, especially in patients who present with cranial symptoms of the disease. Objectives To assess the value of AXs ultrasound in the ultrasonographic diagnosis of GCA, particularly in patients with predominantly cranial symptoms of GCA. Methods Observational retrospective study involving the Rheumatology Departments of Centro Hospitalar Universitário Lisboa Norte (CHULN), Lisbon-Portugal, and the Nuffield Orthopaedic Centre (NOC), Oxford-UK. We included patients with a clinical diagnosis of GCA and a positive ultrasound for GCA at diagnosis, i.e., the presence of a non-compressible halo sign in the TAs or AXs. Information regarding the demographics, clinical manifestations at disease presentation, and therapeutics were collected. Cranial symptoms included headache, temporary or permanent loss of vision, diplopia, blurred vision, jaw or tongue claudication, scalp tenderness or paraesthesia, stroke, or transient ischaemic attack (TIA). Results We included 230 patients, 139 (60.4%) from the NOC and 91 (39.6%) from CHULN. One hundred and thirty-six (59.1%) patients were females, and the mean ± standard deviation age at diagnosis was 75.3 ± 8.5 years. The ultrasound was performed after ten days of treatment with prednisolone ≥30mg/day in 70/230 (30.4%) patients. The presence of halo sign in the TAs was found in 207/230 (90.0%) patients and in the AXs in 57/230 (24.8%) patients. According to the ultrasound pattern presented, 173/230 (75.2%) patients had positive TAs and negative AXs ultrasound, 23/230 (10.0%) had negative TAs and positive AXs ultrasound, and 34/230 (14.8%) had both positive TAs and AXs ultrasound. Cranial symptoms were reported in 207/230 (90.0%) patients, in whom AXs involvement on ultrasound was detected in 43/207 (20.8%) of cases. Concerning only the patients with negative TAs and positive AXs ultrasound, 13/23 (56.5%) reported cranial symptoms. Headache was reported in 10/23 (43.5%), visual symptoms in 6/23 (26.1%), jaw or tongue claudication in 4/23 (17.4%), scalp tenderness or paraesthesia in 4/23 (17.4%), and stroke or TIA in 1/23 (4.3%) patients. Constitutional symptoms were present in 13/23 (56.5%), polymyalgia rheumatica in 9/23 (39.1%), and limb claudication in 1/23 (4.3%) patients. A total of 10/23 (43.5%) patients were on glucocorticoid treatment at the time of the diagnosis, but only 4/23 (17.4%) were on prednisolone ≥30mg/day for at least ten days. Conclusion Axillary involvement in GCA is frequent, affecting around 1/4 of the patients at diagnosis. The additional assessment of the AXs improved the ultrasound diagnostic sensitivity by 10% compared to only assessing the TAs. Patients with AXs involvement were reported to have cranial symptoms in 43/57 (75.4%) of cases. More than half of the patients with negative TAs and positive AXs ultrasound presented with cranial symptoms. Our results support the need to assess the AXs in patients with suspected GCA, regardless of the presence or absence of cranial symptoms. Reference [1]Dejaco C, Ramiro S, Duftner C, et al. EULAR recommendations for the use of imaging in large vessel vasculitis in clinical practice. Ann Rheum Dis 2018;77:636–43. Acknowledgements: NIL. Disclosure of Interests None Declared. Keywords: Diagnostic tests, Imaging, Vasculitis DOI: 10.1136/annrheumdis-2023-eular.4441Citation: , volume 82, supplement 1, year 2023, page 761Session: Diagnostics and imaging procedures (Poster View)