A novel ultrasound-based score for assessing carotid artery activity in Takayasu's arteritis

The role of ultrasonography for evaluating vessel wall inflammation in Takayasu's arteritis (TAK) is well-recognised; however, an effective approach for the quantitative assessment of disease activity remains lacking. This study aimed to develop a novel ultrasound-based score for determining TAK activity.

TAK patients with carotid artery involvement were prospectively followed-up for 6 months. Our proposed ultrasonographic activity score (ULTRAS, range between 0-12) consisted of wall thickness (TS, range between 0-8) and semi-quantitative echogenicity scores (ES, range between 0-4). The diagnostic performance of ULTRAS for disease activity was evaluated in terms of area under the receiver operating characteristic curve (AUC). Internal validation was subsequently performed.

The patients were divided into training and validation groups (n=136 and 30. respectively). In the training group, 83 (61.0%) had active disease. At an optimal cut-off of 7, ULTRAS showed good diagnostic accuracy for active TAK (AUC, 0.88; 95% CI, 82-94). Improved diagnostic performance was achieved when combined with ESR (AUC, 0.91; 95% CI, 86-96) or CRP (AUC, 0.90; 95%CI, 86-95). In the verification group, the AUCs were 0.88, 0.95, and 0.92 for ULTRAS, ESR plus ULTRAS, and CRP plus ULTRAS, respectively. At post-treatment follow-up, the TS, ES, and ULTRAS paralleled the patients' disease remission and symptom recovery. At 3-month follow-up, an improvement in wall thickness of ≥0.3 mm correlated with symptom recovery in 50% of the patients.

Our proposed ultrasound-based score carries the potential in the detection of active disease among TAK patients.