ThP8.7 - Giant Cell Arteries: Diagnostics

Abstract Aim Giant cell arteritis (GCA) poses a risk of severe ischaemic complications such as irreversible blindness which mandates early recognition of condition. We aimed to evaluate effectiveness of ultrasound doppler (USD) in diagnosing GCA compared to temporal artery biopsy (TAB) and American College of Rheumatology (ACR) score. Method This retrospective study included patients with suspected GCA who had consecutive TAB and USD examinations performed over a course of three years (2017-2022) which was correlated with ACR score. The data was also analysed to assess further management. Results There were 64 patients over this period who had both studies performed (22 were excluded as they did not have TAB) with 64% having an ACR score ≥3. Twenty males and forty-four females with a median age of 77 years (IQR 84-67). Overall, 81% patients had a negative USD result. Comparing USD results with TAB gold standard, there was sensitivity of 63% and specificity of 84%. Comparing USD results with ACR as gold standard, there was sensitivity of 20% and specificity of 83%. Forty percent patients with negative doppler result were continued on treatment mainly due to improvement of symptoms in response to steroids. Conclusion US Doppler has high diagnostic specificity and low sensitivity which makes it time-efficient, cost-effective and allows for the implementation of fast-track management pathway for majority patients. In certain circumstances, as cases of low clinical suspicion and positive doppler result, an additional test (TAB) would be required to confirm the diagnosis and cases where clinical suspicion is high with negative doppler, TAB should be considered.