ObjectiveTo describe the clinical features, treatment, and outcomes in a longitudinal cohort of patients with Takayasu arteritis (TAK). Patients and MethodsWe retrospectively studied patients with newly diagnosed TAK evaluated from January 1, 1984, through December 31, 2009. ResultsThe cohort included 126 patients who were predominantly white (85/103; 82.5%) and female (115/126; 91%). The median age at diagnosis was 31.6 years (interquartile range, 22.9-39.8 years). Median delay in diagnosis was 17.5 months (interquartile range, 7-41.8 months). Thirty-one patients (25%) were 40 years or older at diagnosis. Median delay in diagnosis for patients 40 years or older was 44.8 months compared with 28.3 months for those younger than 40 years (P<.001). Limb claudication was the presenting symptom in 64 of 123 patients (52%). Hata type V arteriographic abnormalities were the most common (57/100; 57%). Renal artery abnormalities were observed in 24 of 41 patients (58%) with new-onset hypertension. Inflammatory markers were elevated at diagnosis in 85 of 119 patients (71%). Vascular interventions were performed in 69 patients (55%). Seventy-nine patients (63%) were followed up for more than 1 year (median follow-up, 5.5 years; interquartile range, 2.9-10.0 years). In this subset, treatment consisted of corticosteroids in 73 patients (92%) and additional immunosuppressants in 52 patients (66%). At 5 years, 96% experienced at least one remission of any duration. The overall survival was 97% at 10 years and 86% at 15 years. Mortality was increased compared with the general population (standardized mortality ratio, 3.0; 95% CI, 1.0-8.9). ConclusionThere continues to be an unacceptably long delay in the diagnosis of TAK. Awareness of TAK in patients older than 40 years is needed. Morbidity was high despite immunosuppressive treatment. Survival was decreased in this cohort.