The following is a summary of “Usefulness of Subclavian Artery Ultrasound Assessment in Giant Cell Arteritis Evaluation,” published in the January 2023 issue of Rheumatology by Oshinsky, et al.

Giant cell arteritis (GCA) is more frequently diagnosed using vascular ultrasonography. The axillary and temporal arteries are frequently examined. The subclavian artery was included, although its value was still debatable. For a study, researchers sought to determine if including the subclavian artery in addition to the temporal and axillary arteries would increase the accuracy of the ultrasound assessment of GCA beyond that of using only the temporal and axillary arteries.

They established a fast-track clinic to quickly assess patients with suspected GCA using ultrasonography. Patients who were referred for vascular ultrasonography for GCA in the cohort research had a new worry about GCA. Retrospective evaluations were done on subclavian intima-media thickness (IMT) cutoffs of 1.0 and 1.5 mm.

About 233 individuals were sent to the fast-track clinic between November 2017 and August 2021. Around 158 individuals had ultrasounds because they were worried about a new GCA. Inclusion of the subclavian artery did not find any individuals with GCA who were not already found to have positive temporal and/or axillary artery exams at a subclavian IMT threshold of 1.5 mm, and at this cutoff, there was 1 false-positive result. However, most patients with an isolated subclavian IMT larger than 1.0 mm had false-positive findings, and the specificity of this cutoff was low. Several participants were diagnosed with GCA and had otherwise normal ultrasounds thanks to a subclavian IMT cutoff of 1.0 mm.

The subclavian artery was included in the ultrasound assessment of the GCA at 2 distinct cutoffs, although it seldom helped to accurately diagnose the condition and increased the incidence of false-positive results.