AB0382 DOES THE ULTRASOUND IMAGE OF THE LARGE VESSEL WALLS DIFFER IN THE SUBTYPES OF GCA AND PMR OR THERE IS A SYSTEMIC SUBCLINICAL COMMON INFLAMMATION?
Authors: E. Fernández-Fernández, I. González-Mazón, I. Monjo, J. M. Mostaza, C. Lahoz, E. De Miguel
Journal: Annals of the Rheumatic Diseases (2021)

Background: Several clinical patterns of giant cell arteritis (GCA) have been described including cranial GCA (c-GCA), large vessel GCA (LV-GCA), mixed forms of c-GCA and LV-GCA (mixed-GCA), and even polymyalgia rheumatica (PMR) that has been associated with GCA and some degree of subclinical vascular inflammation could be present in the patients. However, many questions about this disease and its subtypes remain unanswered. Objectives: To investigate the affectation of the arterial wall of GCA and its subtypes and PMR and to know if there really are different ultrasound patterns that can be determined or if otherwise they present a common subclinical systemic inflammation with only different degrees of involvement of the vascular wall. Methods: All available ultrasound examinations of patients referred to our fast-track GCA clinic for suspected GCA in the last three years were reviewed and retrospectively collected data. Patients who had undergone ultrasound examination of both cranial and large vessels (axillary, subclavian and carotid arteries) were included. The videos and images of the large vessels of each patient were reviewed and intima-media thickness (IMT) and hypoechoic halo measurements were taken. The data of the following groups, established according to the final diagnosis confirmed by the doctor after a follow-up between six months and three years, were compared: GCA group (within it 3 other groups were included: c-GCA, LV-GCA and mixed-GCA), PMR group and the group without ACG or PMR (non-GCA). Results: We analyzed the examinations of 300 patients and 161 baseline examinations were included: 76 with GCA (32 c-GCA, 14 LV-GCA and 30 mixed-GCA), 29 with PMR and 56 non-GCA. The mean IMT for each large vessel explored and the statistical significance between the different groups are shown in Table 1. All arteries except the carotid arteries had a significantly higher IMT in the LV-GCA and mixed-GCA groups when compared with both c-GCA and non-GCA groups. There were no differences in IMT between mixed-GCA and LV-GCA. There were also no differences in any explored artery between PMR and non-GCA. There were statistically significant differences in the IMT of the bilateral axillary and subclavian arteries between the PMR group and all the GCA subtypes, being greater in the latter. IMT tended to be higher in the c-GCA group when compared to non-GCA, reaching statistical significance in the left arteries (axillary, subclavian, and distal carotid). Although there was also a tendency for IMT to be higher in mixed-GCA patients than in LV-GCA patients, the differences did not reach statistical significance. Table 1. Ultrasound IMT and halo measures in the different subtypes of GCA, PMR and controls Arteries Non-GCA n=56 GCA n=76 c-GCA n=32 LV-GCA n=14 Mixed-GCA n=30 PMR n=29 p &lt; 0.05 Right axillary (mean ± SD ) 0.67±0.19 0.95±0.30 0.75±0.20 1.03±0.33 1.11±0.27 0.65±0.13 2*, 3*, 4*, 5*, 6, 7*, 8* Left axillary (mean ± SD ) 0.61±0.12 0.92±0.29 0.77±0.19 0.99±0.25 1.03±0.33 0.66±0.13 1*, 2*, 3*, 4, 5*, 6, 7*, 8* Right subclavian (mean ± SD ) 0.70±0.15 1.00±0.31 0.79±0.16 1.09±0.36 1.10±0.29 0.70±0.20 2*,3*, 4*, 5*, 7*, 8* Left Subclavian (mean ± SD ) 0.62±0.14 0.95±0.27 0.76±0.16 1.05±0.25 1.06±0.26 0.64±0.18 1*, 2*, 3*, 4*, 5*, 7*, 8* Right CCD (mean ± SD ) 0.79±0.22 0.97±0.26 0.99±0.22 0.91±0.29 1.05±0.28 0.81±0.10 1*, 3*, 6*, 8* Left CCD (mean ± SD ) 0.81±0.16 0.99±0.22 0.95±0.20 0.97±0.17 1.03±0.27 0.82±0.20 1, 2, 3*, 8 SD: Standard deviation; CCD: common distal carotid artery. 1=c-GCA vs non-GCA; 2=LV-GCA vs non-GCA; 3=mixed-GCA vs non-GCA; 4=c-GCA vs LV-GCA; 5=c-GCA vs mixed-GCA; 6=PMR vs c-GCA; 7=PMR vs LV-GCA; 8=PMR vs mixed-GCA; *p &lt; 0.01. Conclusion: Large vessel ultrasound does not differ between healthy patients and those with PMR without confirmed GCA. Our data suggest that mixed-GCA subtype is not an intermediate form between the cranial and LV-GCA suptypes but could have a higher inflammatory burden. Disclosure of Interests: Elisa Fernández-Fernández: None declared, Iñigo González-Mazón: None declared, Irene Monjo Speakers bureau: Roche, Novartis, UCB, Gedeon Richter, Consultant of: Roche, José María Mostaza: None declared, Carlos Lahoz: None declared, 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