Ultrasound activity score in the carotid arteries for assessing disease activity of Takayasu arteritis

Abstract

Objective: The role of ultrasonography for evaluating vessel wall inflammation in Takayasu arteritis (TAK) is well-recognized; however, an effective approach for the quantitative assessment of disease activity remains lacking. This study aimed to develop a novel ultrasound-based scoring system for determining TAK activity. Methods:TAK patients with carotid artery involvement were prospectively followed-up for 6 months. Their clinical symptoms, inflammatory biomarkers, and ultrasonographic features at baseline and follow-up were recorded. Our proposed ultrasound activity score (ULTRAS) consisted of wall thickness (TS) and semi-quantitative echogenicity scores (ES). 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. Results: A total of 136 patients were included. 83 (61.0%) of whom had active disease. Active TAK demonstrated significantly increased ESR and CRP levels, greater wall thickness and proportion of low echogenicity on ultrasonography, and higher TS, ES, and ULTRAS. At an optimal cut-off of 7, ULTRAS showed satisfactory 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). At 3-month follow-up, an improvement in wall thickness of ≥0.3 mm correlated with symptom recovery in 50% of patients. Conclusions: Our proposed ultrasound-based scoring model carries the potential in the detection of active disease among TAK patients.