Time to diagnosis in large vessel vasculitis: insights from a retrospective study at a tertiary rheumatology centre.

To evaluate the diagnostic pathway of patients affected by large vessel vasculitis (LVV) and to determine factors associated with the time to diagnosis including referring and previously consulted medical specialties. This retrospective single-centre study enrolled patients diagnosed with giant cell arteritis (GCA) and Takayasu arteritis (TAK) between January 2014 and May 2025. Clinical, laboratory and referral data were retrieved from medical records. Time to diagnosis was defined as the interval between the onset of first LVV-related symptoms and the confirmed diagnosis. Factors associated with diagnostic delay were analysed by multivariate Cox regression. Temporal differences were visualised using Kaplan-Meier curves. In total, 501 patients were included (GCA n=488; TAK n=13). Compared with GCA (89 days (IQR 31-184)), the median time to diagnosis for TAK (245 days (IQR 31-1308)) was longer. Presentation with typical cranial symptoms was associated with a shorter diagnostic interval (HR 1.27, p=0.022), involvement of the aorta and its major branches was linked to prolonged delay (HR 0.64, p<0.001). Prior medical consultations by rheumatologists were associated with longer diagnostic delay (HR 0.73, p=0.004), whereas referrals by ophthalmologists (HR 2.40, p=0.001) and cardiologists (HR 3.81, p=0.008) were associated with earlier diagnosis. Diagnostic delay varies by subtype and clinical presentation. Time to diagnosis was longer in TAK compared with GCA, whereas typical cranial symptoms facilitate earlier diagnosis. Increasing awareness is crucial to minimise diagnostic delay and prevent organ damage.