Background/Purpose: Takayasu Arteritis (TAK) is a systemic large-vessel vasculitis that mostly affects women of childbearing age. The worldwide incidence of TAK varies due to genetic and/or environmental factors. We describe the frequency, clinical features and outcomes of TAK in Western Australia (WA).

Methods: Cohort study of TAK patients identified in the Western Australian population (2.4 million) through multiple sources including hospital discharge codes between 1-1-2000 and 30-5-2015. 

Results:   Sixteen patients with a clinical TAK diagnosis were identified of whom 11/16 fulfilled 1990 ACR criteria for TAK. All were female and 81% were Caucasian. The median age at diagnosis was 33 years (interquartile range, 27-44 years) with 2 patients (18%) > 40 years at time of diagnosis. The median time to diagnosis was 6 months (interquartile range 2-32 months). Limb claudication was the most common presenting symptom, present in  5/11 patients (45%), followed by fatigue in 4/11 patients (36%). ESR and/or CRP were elevated at diagnosis in only 5 patients (45%). Hata type 2a arteriographic abnormalities were the most common (55%).  All patients received corticosteroids as initial treatment and all were commenced on additional immunosuppressant agents (Methotrexate in 73%). There was one death during the study period. Four patients (36%) developed cerebrovascular disease, 3 suffered more than one stroke.  Two patients (18%) suffered acute myocardial infarction. Vascular intervention was performed in 3 patients (27%).

Conclusion: TAK prevalence in WA is at least 4.2/million based on ACR criteria. The high morbidity despite immunosuppressive treatment might be related to a long delay to diagnosis and indicates a need for better tools to achieve earlier diagnosis.