Ultrasound for diagnosis and follow-up of chronic axillary vasculitis in patients with long-standing giant cell arteritis

Philipp Bosch; Christian Dejaco; Wolfgang A Schmidt; Kenny D- Schlüter; Gudrun Pregartner; Valentin S Schäfer

doi:10.1177/1759720X21998505

Ultrasound for diagnosis and follow-up of chronic axillary vasculitis in patients with long-standing giant cell arteritis

Ther Adv Musculoskelet Dis. 2021 Mar 19:13:1759720X21998505. doi: 10.1177/1759720X21998505. eCollection 2021.

Authors

Philipp Bosch¹, Christian Dejaco¹, Wolfgang A Schmidt², Kenny D- Schlüter², Gudrun Pregartner³, Valentin S Schäfer⁴

Affiliations

¹ Department of Rheumatology and Immunology, Medical University Graz, Graz, Austria.
² Medical Centre for Rheumatology Berlin-Buch, Immanuel Krankenhaus Berlin, Berlin, Germany.
³ Institute for Medical Informatics, Statistics and Documentation, Medical University of Graz, Graz, Austria.
⁴ Department of Internal Medicine III, Oncology, Haematology, Rheumatology and Clinical Immunology, University Hospital Bonn, Venusberg-Campus 1, Bonn, Nordrhein-Westfalen 53127, Germany.

Abstract

Aims: To assess intima-media thickness (IMT) changes measured by ultrasound in axillary arteries of giant cell arteritis (GCA) patients over time and to calculate an ultrasound cut-off value for the diagnosis of chronic axillary artery involvement in patients with longstanding GCA.

Methods: Ultrasound of both axillary arteries was performed in 109 GCA patients at time of diagnosis and at several follow-up visits and in 40 healthy controls (HCs). IMT determined at the prospective follow-up visit was compared between GCA patients with (axGCA) and without (non-axGCA) vasculitis of axillary arteries at baseline, as well as with HCs. Changes in IMT were depicted. Receiver operating characteristics were performed for cut-off calculations. Inter-/intra-rater agreement was evaluated using stored images and intraclass correlation coefficient (ICC).

Results: Seventy-three patients were in the axGCA and 36 in the non-axGCA group. Pathological IMT of axillary arteries (axGCA) declined in the first 18 months of treatment by -0.5 mm, (range -2.77 to 0.50), independent of age and gender. Median IMT, after median disease duration of 48 months (16-137), was 0.90 mm (0.46-2.20) in axGCA and 0.60 mm (0.42-1.0) in the non-axGCA group pooled with HCs. An IMT of 0.87 mm was highly specific (specificity 96%, sensitivity 61%) for diagnosis of chronic axGCA. Intra-rater and inter-reader agreement of ultrasound images were good [ICC 0.96-1.0 (three readers) and 0.87, respectively].

Conclusion: Pathological IMT of the axillary artery declined under treatment. An IMT of 0.87 mm is highly specific for diagnosis of chronic vasculitis of axillary arteries in long-standing GCA patients.

Keywords: Ultrasound; giant cell arteritis; imaging; large vessel vasculitis; outcome measure.