Corticosteroids reduce vascular ultrasound sensitivity even with short duration: results from Coventry Multi-Disciplinary Fast Track Pathway for management of Giant Cell Arteritis

Introduction Giant cell arteritis (GCA) is a common form of vasculitis and can result in permanent visual loss and other complications. The advent of vascular Doppler ultrasound (US) has provided a new means for early diagnosis for these patients although it is affected by introduction of corticosteroids (CS). The Coventry multidisciplinary fast track (FTGCA) pathway was set up in 2013 in collaboration with vascular physiology and ophthalmology with a view to enabling prompt multidisciplinary assessment. Objectives This study aims to assess feasibility of this novel pathway and to assess the impact of CS use on the performance of US in a real life cohort. Methods Data were collected retrospectively for patients who attended the Coventry FTGCA pathway between 1st Jan 2014 to 31st December 2017. Patients were identified from US lists and clinical details were obtained from electronic medical records. Ethical approval was obtained from Research and Development department. Results 620 eligible patients were included in this study. The pathway overall performed well with significant reduction in patients needing CS. US had sensitivity of 50% which improved further to ∼56% in CS naïve patients although median duration of CS use was 2 days. US specificity was >96%, and we were able to avoid using CS completely in 451 patients (73%). CS negatively impacted on utility of US with US more likely to be false negative. Conclusions This novel pathway demonstrates the ability to minimise use of CS through fast track multidisciplinary assessment. US was performed promptly and had reassuring real life sensitivity and specificity in this cohort. CS naïve patients showed significantly higher sensitivity for US despite the short duration of CS use.