FRI0199 PRESENCE AND DISTRIBUTION OF VASCULITIS IN TEMPORAL, AXILLARY AND SUBCLAVIAN ARTERIES IN GIANT CELL ARTERITIS ASSESSED BY ULTRASONOGRAPHY AT ONSET OF DIAGNOSIS. (13th June 2020) - Andel, P. M.
Abstract : Background: In the last two decades ultrasound (US) has become a significant and valuable mode of diagnosing giant cell arteritis (GCA) in clinical practice (1). This is also reflected in the suggested expansion of the ACR 1990 criteria where imaging including US is equated with biopsy (2). Favorable sensitivity compared to biopsy has been shown and explained with the widespread uneven distribution of inflammation in cranial and extracranial arteries (3). Objectives: To explore the prevalence and distribution of inflammatory involvement in temporal, axillary and subclavian arteries in patients diagnosed with GCA at an ordinary rheumatology clinic. Methods: In this retrospective study we identified all patients diagnosed with GCA between 2006 and 2019. Since 2006 US has been used at the clinic to diagnose GCA. The vascular US examination was performed by two experienced ultrasonographers (HB, APD). The medical records were reviewed and data were collected using a predefined protocol including data collection for US at the time of diagnosis. Standard US procedure contained an assessment of both temporal arteries (superficial artery, frontal artery and parietal artery) in longitudinal and transversal planes with and without colordoppler mode. A positive US test was defined in presence of hypoechoic vessel wall thickening (halo sign). The axillary and subclavian arteries where assessed in B-mode and intima media thickness (IMT) was measured. A positive test was defined if IMT > 1 mm. Results: A total of 69 GCA patients (20 men and 49 women) with US performed at the time of diagnosis were identified. Among them, 67 (97.1%) patients met the suggested expansion ACR 1990 criteria. The mean age was 69.9 years. Detailed results for vasculitis distribution for the temporal artery with its branches and the axillary and subclavian arteries are shown in the table below. Positive US findings were recorded in 61 patients (88.4%). A total of 45 patients (65.2%) had a positive US test in the temporal artery and 41 patients (59.4%) in the extracranial arteries. Solely extracranial arteritis was observed in 18 patients (29.5%), 22 (36.0%) had exclusively temporal involvement. Involvement of both cranial and extracranial arteries was observed in 21 patients (34.4%). Only nine patients had positive findings at just one site. Five patients had isolated unilateral subclavian affection, and two patients had isolated unilateral frontal artery and superficial artery involvement each. Conclusion: Our data highlights the importance and value of a complete US of cranial and extracranial arteries diagnosing GCA in daily clinical care. The data demonstrate the widespread nature of arterial affection in GCA and the fact that it is often more than one site that is affected. The spreading pattern was comparable to older studies in the respect of large vessel and multisite involvement. References: [1]Dejaco C. et al. Ann Rheum Dis. 2018;77:636-43. [2]Dejaco C et al. Rheumatology 2017;56:505-15. [3]Schmidt W A. Rheumatology. 2018;57;ii22-ii31. Disclosure of Interests: Peter Michael Andel Grant/research support from: Travel Grant from Vest Agder Legeforening, Norge, Serina Brådland: None declared, Vilde Haraldstad: None declared, Helle Bitter: None declared, Andreas Diamantopoulos: None declared, Glenn Haugeberg: None declared