Ab0739 performance of the 2022 american college of rheumatology/eular classification criteria for giant cell arteritis in a cohort of patients with suspicion of having giant cell arteritis

Background The new ACR/EULAR 2022 classification criteria for giant cell arteritis (GCA) use weighted items and incorporate findings from vessel imaging to reflect the current clinical standard. Although intended to define homogenous patient populations for research purposes when a diagnosis of medium- or large-vessel vasculitis has been made, the 2022 criteria were developed including non-vasculitis comparators. Hence, in the absence of a sensitive diagnostic gold standard, the criteria bear potential to be used for GCA diagnosis. Objectives To evaluate the performance of the new 2022 ACR/EULAR classification criteria for GCA when used for GCA diagnosis. Methods Retrospective analysis of a cohort of patients suspected of having GCA who underwent ultrasound between 12/2006 and 05/2021. GCA was diagnosed if temporal artery biopsy was positive, if the 1990 ACR criteria were fulfilled, or if at least 2/5 ACR criteria were fulfilled in combination with vasculitis on imaging. Results 276 patients were diagnosed with GCA, and 400 patients had a condition that mimics GCA. When applying the 2022 criteria as diagnostic criteria, sensitivity remained high with 87.3% (95% CI 82.8%–91.0%), whereas specificity was lower with 70.3% (95% CI 65.5% to 74.7%). In 35 patients (12.7%) with GCA, the criteria were not met (Table 1). These were mainly patients without cranial symptoms but having typical imaging findings in vascular territories not considered in the criteria. 119 non-GCA patients (29.8%) scored ≥6 points. Polymyalgia rheumatica (PMR) (31.9%) followed by non-vasculitic ophthalmologic diseases (15.1%) were the most frequent diagnoses among those. Conclusion The inclusion of polymyalgic symptoms and heavy weighting of sudden visual loss in the score led to false classification of patients with PMR and ophthalmologic diseases as GCA. For diagnostic purposes, the scoring of the criteria could potentially be adapted by applying a higher cut-off for the diagnosis of GCA or a lower weighting for polymyalgic and visual symptoms. References [1]Ponte C, Grayson PC, Robson JC, et al. 2022 American College of Rheumatology/EULAR classification criteria for giant cell arteritis. Arthritis Rheumatol.2022. doi: 10.1002/art.42325. Table 1. 2022 American College of Rheumatology/ EULAR classification criteria for giant cell arteritis in patients with GCA and non-GCA Total number of patients (n=676) GCA patients with <6 points (n=35) GCA patients with ≥6 points (n=241) p-value Non-GCA patients <6 points (n=281) Non-GCA patients ≥6 points (n=119) p-value Age, mean (±SD) 71.8 (9.7) 71.3 (8.7) 73.5 (8.4) 0.167 71.2 (10.2) 70.2 (11.0) 0.393 Female, n (%) 398 (58.9) 21 (60.) 150 (62.2) 0.799 155 (55.2) 72 (60.5) 0.324 ACR/EULAR criteria Morning stiffness in shoulders/neck, n (%) 287 (42.5) 8 (22.9) 98 (40.7) 0.004 104 (37.0) 77 (64.7) <0.001 Sudden visual loss, n (%) 78 (11.5) 0 (0.0) 36 (14.9) 0.01 21 (7.5) 21 (17.6) 0.002 Jaw or tongue claudication, n (%) 147 (21.7) 0 (0.0) 110 (45.6) <0.001 9 (3.2) 28 (23.5) <0.001 New temporal headache, n (%) 347 (51.3) 11 (31.4) 158 (65.6) <0.001 84 (29.9) 94 (79.0) <0.001 Scalp tenderness, n (%) 139 (20.6) 1 (2.9) 95 (39.4) <0.001 9 (3.2) 34 (28.6) <0.001 Abnormal examination of the temporal artery, n (%) 111 (16.4) 1 (2.9) 83 (34.4) <0.001 7 (2.5) 20 (16.8) <0.001 Maximum ESR ≥50 mm/hour or maximum CRP ≥10 mg/liter, n (%) 504 (74.6) 29 (82.9) 226 (93.8) 0.004 150 (53.4) 99 (83.2) <0.001 Positive temporal artery biopsy or halo sign on temporal artery ultrasound, n (%) 194 (28.7) 2 (5.7) 186 (77.2) <0.001 0 (0.0) 6 (5.0) <0.001 Bilateral axillary involvement, n (%) 38 (5.6) 2 (5.7) 35 (14.5) 0.191 0 (0.0) 1 (0.8) 0.3 FDG-PET activity throughout aorta, n (%) 52 (7.7) 5 (14.3) 36 (14.9) 0.919 8 (2.8) 3 (2.5) 1 CRP=C-reactive protein; ESR=erythrocyte sedimentation rate; FDG-PET=fluorodeoxyglucose-positron emission tomography; IQR=interquartile range; n=number; PMR=Polymyalgia rheumatica; SD=standard deviation; TA=temporal artery, TAB=temporal artery biopsy. Acknowledgements The authors would like to thank the Swiss Foundation for Research on Muscle Diseases (FSRMM) for supporting the Ph.D. of Andrea Hemmig. Disclosure of Interests None Declared.