Bronson T. Bomkamp, MD; Andrew J. Borgert, PhD; Alec J. Fitzsimmons, MPH; Travis J. Smith, MD; Irina Shakhnovich, MD; Jacob R. Peschman, MD
Background: Temporal artery biopsy is ordered when clinical symptoms and an elevated C-reactive protein values and/or erythrocyte sedimentation rates suggest giant cell arteritis. The percentage of temporal artery biopsies positive for giant cell arteritis is low. The objectives of our study were to analyze the diagnostic yield of temporal artery biopsies at an independent academic medical center and to develop a risk stratification model for triaging patients for possible temporal artery biopsy.
Methods: We retrospectively reviewed the electronic health records of all patients who underwent temporal artery biopsy in our institution from January 2010 through February 2020. We compared clinical symptoms and inflammatory marker (C-reactive protein and erythrocyte sedimentation rate) values of patients whose specimens were positive for giant cell arteritis with those of patients with negative specimens. Statistical analysis included descriptive statistics, chi-square test, and multivariable logistic regression. A risk stratification tool, which included point assignments and measures of performance, was developed.
Results: Of 497 temporal artery biopsies for giant cell arteritis performed, 66 were positive and 431 were negative. Jaw/tongue claudication, elevated inflammatory marker values, and age were associated with a positive result. Using our risk stratification tool, 3.4% of low-risk patients, 14.5% of medium-risk patients, and 43.9% of high-risk patients were positive for giant cell arteritis.
Conclusions: Jaw/tongue claudication, age, and elevated inflammatory markers were associated with positive biopsy results. Our diagnostic yield was much lower when compared with a benchmark yield determined in a published systematic review. A risk stratification tool was developed based on age and the presence of independent risk factors.