P205 The contemporary presentation and management of giant cell arteritis with large vessel vasculitis

Abstract

Abstract Background/Aims Giant cell arteritis with large vessel vasculitis (LV-GCA) represents a distinct, less researched sub-category of giant cell arteritis (GCA). In comparison to cranial GCA, the patient’s diagnostic pathway is less well described and it is thought that LV-GCA is underdiagnosed, including in patients with polymyalgia rheumatica and cranial-GCA. Advances in imaging (e.g. PET-CT) and treatment (tocilizumab), have provided additional options in the diagnosis and management of LV-GCA. The aim was to describe the contemporary clinical journey for patients diagnosed with LV-GCA. Methods The electronic patient health record system in NHS Lothian (TrakCare) was used to collect relevant data. Patients with imaging-confirmed large vessel vasculitis, diagnosed with GCA after 1 January 2017 were included. Follow-up was until August 2020. Results Eighteen patients with LV-GCA were included. The mean age was 65 years and 66.7% were female. Two patients had known cranial-GCA but 89% of patients were diagnosed exclusively with large vessel involvement. The most common symptoms were malaise (55%), weight loss (55%), polymyalgia rheumatica (55%) and limb claudication (44%). Pyrexia of unknown origin was a feature in only 17% of patients. Two patients were asymptomatic and were investigated on the basis of raised inflammatory markers. Mean CRP at baseline was 99mg/L and ESR 85mm/hour. The mean time from symptom-onset to diagnosis was 6.8 months (range 1 to 15 months). Sixteen patients (89%) were reviewed by at least one other secondary care specialist. One third of patients were referred from General Medicine followed by Vascular Surgery (16%) and General Practice (16%). 7/18 patients were inpatients at the time of referral. 56% of patients required two modalities of imaging to confirm large vessel involvement. The most commonly used imaging techniques (in descending order) were CT-Chest/Abdomen/Pelvis, CT-angiogram, PET-CT and Vascular Ultrasound. 50% of patients underwent follow-up imaging, most commonly MR- or CT-angiography. Mean follow-up was for 1.6 years. The mean prednisolone dose at 3 months (n = 18) was 24mg daily and 8mg at 12 months (n = 12). 28% of patients relapsed during the follow-up period at 4, 5, 8, 9 and 24 months post-diagnosis. 7/18 patients were commenced on methotrexate for steroid-side effects or for relapse. 8/18 received subcutaneous tocilizumab in combination with methotrexate in two cases. Three patients were started on azathioprine but only one continued. Conclusion In modern-day clinical practice, patients with LV-GCA experience a longer time to diagnosis than those with cranial symptoms. Patients with LV-GCA can experience an array of constitutional symptoms. Frequently, more than one imaging modality is required to confirm LV-GCA and the majority of patients will have seen other hospital specialists or have been admitted to hospital before diagnosis. Methotrexate and tocilizumab are the most frequently-used and effective steroid-adjunct in this single-centre cohort. Disclosure O. Cronin: None. N.D. McKay: Consultancies; Gilead. Other; Has received support for conference attendance from Pfizer and Gilead, Has received educational support from UCB, Gilead, Celgene, Biogen, Sanofi, Abbvie, Novartis, Pfizer. H. Preston: None. H. Harris: None. B. Hauser: None.