POS0812 SUBCLAVIAN ARTERIES INVOLVEMENT IN PATIENTS WITH GIANT CELL ARTERITIS: DO WE NEED A MODIFIED HALO SCORE?
Authors: J. Molina Collada, J. Martínez-Barrio, B. Serrano-Benavente, I. Castrejon, J. C. Nieto González, L. R. Caballero Motta, L. Trives Folguera, J. M. Alvaro-Gracia
Journal: Annals of the Rheumatic Diseases (2021)

Background: EULAR recommendations propose temporal and axillary arteries ultrasound (US) as first-line investigation when predominantly cranial giant cell arteritis (GCA) is suspected. Recently, two novel US scoring systems, the halo count and the Southend Halo Score, have been developed to quantify the extent of inflammation by US in GCA. Objectives: To assess whether adding the subclavian arteries examination into the ultrasound (US) Southend Halo Score, as proposed in the modified Halo Score, improves the diagnostic accuracy of GCA and its relationship with systemic inflammation. Methods: Retrospective observational study of patients referred to a GCA fast track pathway (FTP) over a 1-year period. Patients underwent US exam of temporal and large vessel (LV) (carotid, subclavian and axillary) arteries. The extent of inflammation was measured by the halo count, the Southend Halo Score and the modified Halo Score (Image 1). The gold standard for GCA diagnosis was clinical confirmation after 6 months follow-up. Results: 64 patients were evaluated in the FTP, 17(26.5%) had GCA. Subclavian arteries involvement was present only in patients with GCA (29.4% versus 0%,p&lt;0.001) (Table 1). Overall, the three scores showed excellent diagnostic accuracy for GCA (ROC AUC 0.906, 0.930 and 0.928, respectively) and moderate correlations with acute phase reactants (0.35-0.51, p&lt;0.01). However, in the subgroup of patients presenting LV involvement, moderate correlations were found between the modified Halo Score and ESR (rho 0.712, p&lt;0.05), haemoglobin (rho 0.703, p&lt;0.05) and platelets (rho 0.734, p&lt;0.05), but not with the other two US scores. Figure 1. Proposed scores to quantify the extent of vascular inflammation by ultrasound in giant cell arteritis. A. Halo count, B. Halo Score, C: Modified Halo Score Table 1. Clinical, laboratory and ultrasound findings of patients included in the fast track pathway with or without GCA clinical confirmation. Total n=64 Patients with GCA n=17 Patients without GCA n=47 p Age, median (IQR ) 78 (69.3-83) 78 (72.5-83) 78 (66-83) 0.5 Female, n (% ) 42 (65.6%) 10 (58.8%) 32 (68.1%) 0.491 Temporal artery biopsy positive n=13, no. of patients 5 (38.5%) 5 (50%) 0 (0%) 0.231 18 F-FDG-PET/CT positive n=14, no. of patients 7 (50%) 5 (62.5%) 2 (33.3%) 0.592 Fulfilling 1990 GCA criteria, no. of patients 16 (25%) 8 (47.1%) 8 (17%) 0.022 PMR diagnosis before US examination, no. of patients 21 (32.8%) 4 (23,5%) 17 (36,2%) 0.386 Headache, no. of patients 31 (48.4%) 12 (70.6%) 19 (40.4%) 0.033 Jaw claudication, no. of patients 12 (18.8%) 9 (52.9%) 3 (6.4%) &lt;0.001 Ocular ischaemia, no. of patients 4 (6.3%) 2 (11.8%) 2 (4.3%) 0.285 Abnormal TA clinical examination, no. of patients 5 (7.8%) 3 (17.6%) 2 (4.3%) 0.112 CRP (mg/dL), median (IQR ) 1.7(0-6.5) 7 (2.1-14) 1.1 (0-5.1) 0.001 ESR (mm/h), mean (SD ) 52.8 (34.6) 68.3 (33.3) 46.8 (33.3) 0.044 Haemoglobin (g/dL), mean (SD ) 12.5 (1.7) 11.8 (1.6) 12.7 (1.7) 0.059 Platelets 10 9 /L, mean (SD ) 276.1 (105.8) 323.4 (116.3) 258.7 (97.3) 0.52 Positive US findings, no. of patients 17 (26.6%) 15 (88.2%) 2 (4.3%) &lt;0.001 Temporal artery positive US findings, no. of patients 13 (20.3%) 12 (70.6%) 1 (2.1%) &lt;0.001 Axillary positive US findings, no. of patients 9 (14.1%) 8 (47.1%) 1 (2.1%) &lt;0.001 Subclavian positive US findings, no. of patients 5 (7.8%) 5 (29.4%) 0 (0%) &lt;0.001 Temporal artery + axillary or subclavian positive US findings, no. of patients 5 (7.9%) 5 (29.4%) 0 (0%) 0.003 Halo Count, median (IQR ) 0 (0-0.75) 2 (1-4.5) 0 (0-0) &lt;0.001 Halo Score, median (IQR ) 0 (0-4.5) 18 (7-22.5)) 0 (0-0) &lt;0.001 Modified Halo Score, median (IQR ) 0 (0-2.75) 8 (3-13.5) 0 (0-0) &lt;0.001 Conclusion: The inclusion of subclavian arteries examination in the modified Halo Score does not improve the diagnostic accuracy of GCA. Nevertheless, it correlates better with markers of systemic inflammation in LV-GCA Disclosure of Interests: None declared