Objective: Ultrasound is a standard tool to diagnose giant cell arteritis (GCA). Until now, only a few studies have investigated the role of ultrasound in the follow-up of GCA. The aim of this study was to assess the changes in the intima-media thickness (IMT), total number of affected arteries and provisional OMERACT GCA ultrasonography score (OGUS) in a 12-months follow-up period.

Methods: Patients with newly diagnosed GCA were prospectively enrolled. Ultrasound examinations of facial, temporal, carotid, vertebral and axillary arteries were performed at baseline, after 3, 6, 9 and 12 months. Changes of IMT, total number of affected arteries and OGUS values were evaluated. In a subgroup of patients, exams were conducted weekly in the first 100 days.

Results: Fifty patients were enrolled and 36 completed the follow-up. Significant reductions in IMT, total number of affected arteries and OGUS were observed. Eighteen patients presented to weekly exams. The mean IMT of the axillary artery normalized after 7 days, while IMT of the common temporal artery normalized after 50 days. The mean OGUS values were below 1 after 6 months. There were no differences in IMT changes between GCA patients with or without PMR or between those with and without additional tocilizumab treatment. A relapse occurred in four patients. At relapse, mean IMT and OGUS were higher as compared to the preceding assessment. No predictive values indicating a relapse were identified.

Conclusions: Vascular ultrasound is sensitive to change in GCA. The presence of PMR or treatment with tocilizumab did not affect IMT decrease.