Analysis of factors that determine the diagnostic yield of temporal artery biopsy.

PURPOSE To analyse the diagnostic yield of temporal artery biopsy in the diagnosis of giant cell arteritis, and to correlate these results with the clinical and laboratory features which indicate it, in an attempt to increase the efficiency of this technique and try to "save biopsies". METHODS A retrospective cohort study including suspected giant cell arteritis cases in which a temporal artery biopsy was performed. The data recorded included demographic, clinical and laboratory information. RESULTS A total of 38 patients were analysed. The biopsy was positive in 68.42% of cases. Multivariate analysis revealed visual symptoms and a high C-reactive protein as parameters with a high diagnostic efficiency. CONCLUSIONS Our study supports the fact that temporal artery biopsy should be undertaken when there is strong clinical suspicion. Visual symptoms and high C-reactive protein are considered as a high efficiency indicators to biopsy.