Background/Purpose: Fast-track clinics incorporating ultrasound into the initial evaluation of patients suspected of having giant cell arteritis (GCA) have been implemented throughout Europe leading to reduced incidence of blindness and decreased overall cost of care. Ultrasound is now recommended as one of the initial diagnostic modalities for GCA, assuming availability and expertise per EULAR guidelines. In the United States, the use of ultrasound for GCA diagnosis has been limited to date. Here we report our fast-track GCA clinic experience at Massachusetts General Hospital.

Methods: A fast-track GCA clinic was developed at our tertiary care academic medical center which serves as a referral center for GCA patients. A standardized algorithm was created for referred patients with suspected GCA. Clinical evaluation and a dedicated ultrasound exam of the bilateral temporal and axillary arteries were completed in a single clinic session within 48 hours of referral if the patient was able. Bilateral common superficial, parietal, and frontal branches of the temporal arteries were evaluated for both halo and compression signs, and bilateral axillary arteries for halo sign. Clinical evaluation and ultrasound exam were performed and interpreted by one rheumatologist (MAM). Ultrasound images were reviewed separately by a blinded rheumatologist (MJK), both with expertise in vasculitis ultrasound.

Results: Between September 2019 and March 2020, 18 patients were evaluated in the fast-track GCA clinic. Overall, 15 patients (83%) were seen within 48 hours, 11 patients (61%) within 24 hours and 2 patients within 1 hour of referral. Mean age was 72 years, 67% were female and 83% were Caucasian (17% Hispanic). Temporal headache was reported by 89% of patients. Mean ESR was 24.7 mm/h, mean CRP was 40.6 mg/L, and 6 patients had acute phase reactants within normal limits. Four patients (22%) had a positive temporal (n = 3) or axillary (n = 1) artery ultrasound confirmed by the blinded reviewer. Three of the 4 patients with a positive ultrasound also had a positive temporal artery biopsy (TAB). The remaining patient had relapsing GCA previously diagnosed with TAB, therefore a new biopsy was not pursued. In total, 10 patients underwent TAB after ultrasound. Mean time from fast-track evaluation to TAB was 6 days. There were no conflicting results between ultrasound and TAB. Four patients with negative results on both ultrasound and TAB and one additional patient who declined TAB went on to be treated for GCA given clinical suspicion. The remaining patients were diagnosed with headache (n = 5), infection (n = 2), cardioembolic transient vision loss (n = 1) and vasculitis not otherwise specified (n = 1). Of note, 1 patient with classic symptoms of GCA and a clearly positive ultrasound was found to have normal acute phase reactants and positive TAB. No patients developed vision loss attributed to GCA.

Conclusion: Ultrasound at the point of care is an effective diagnostic tool in GCA, assuming adequate training and availability. TAB can be obtained to confirm ultrasound findings particularly during the initial phase of a fast-track clinic. For a subset of patients with negative ultrasound and TAB, the diagnosis of GCA was made on clinical grounds.

« Back to ACR Convergence 2020

ACR Meeting Abstracts - https://acrabstracts.org/abstract/fast-track-giant-cell-arteritis-clinic-experience-in-the-united-states/