A prospective cohort study evaluating the role of quantifying sonographic inflammatory changes in GCA.

Objectives: Vascular ultrasound (VUS) is a well-validated tool for diagnosing GCA [1]. The role of VUS in prognostication and disease-monitoring remains to be defined.

Methods: This study compares intima-media thickness (IMT), Halo Count (HC), Halo Score (HS) and OMERACT GCA US Score (OGUS) at multiple time points in a prospective cohort of GCA patients to evaluate the role of sonographic vasculitis quantification in the diagnosis and management of GCA. Longitudinal trends and time-to-normalization of HC, HS and OGUS were evaluated. Correlation coefficients, AUC analysis and DeLong test were used to determine which patient factors may predict VUS outcomes and which patient factors are predictive of adverse events.

Results: Forty-eight of 50 patients were followed up at 6 months and 27 at 12 months. Mean HC, HS, IMT and OGUS all declined significantly over 12 months. Of 48 patients, HC, HS and OGUS normalized in 21, 32 and 39 patients, respectively, by 6 months. Fulfilling 2022 ACR/EULAR Classification Criteria showed moderate correlation with baseline HC, HS and OGUS with higher classification criteria scores showing strong correlation with higher VUS outcome scores. HC, HS and OGUS were superior to all clinical and laboratory parameters for predicting future adverse events with OGUS outperforming HC and HS.

Conclusion: VUS quantification scores performed better than other clinical variables in predicting future adverse events in GCA and OGUS is validated in a prospective cohort. These data suggest that VUS quantification scores are candidate biomarkers for GCA and may be important outcome variables in clinical trials.