A new prediction model for giant cell arteritis in patients with new onset headache and/or visual loss

Abstract

Objective The gold standard for diagnosis of giant cell arteritis (GCA) is a temporal artery biopsy (TAB). We sought for a clinical useful model to predict when an invasive TAB is not necessary to confirm GCA. Methods A prospective cohort study was conducted with patients > 50 years with possible GCA, presenting with newly onset headache and/or visual loss. Demographical, clinical, laboratory findings and histological data were collected. Results Fifty-six (70%) of the 94 patients showed 1 or more halos of the superficial temporal artery branches. Ultrasound-guided biopsy was positive in 28 patients (30%). Four independent variables predicted a positive TAB: weight loss, bilateral headache, positive halo sign and thrombocytosis. The ROC of the model had an area under the curve of 0.932 with a PPV of 83% and a NPV of 94%. Conclusions Weight loss, bilateral headache, a positive halo sign with duplex and thrombocytosis are the most important clinical and laboratory predictors for GCA in a selected group of patients. Significance In patients > 50 years presenting with new onset headache or visual loss with 3 or more of the above mentioned risk factors, a biopsy of the temporal artery is not needed to confirm the diagnosis GCA. KEY MESSAGES In our study biopsy of the temporal artery was positive in 30% of the patients with possible GCA Weight loss, bilateral headache, a positive halo sign on duplex and thrombocytosis are predictors for GCA The halo sign had a high sensitivity but a low specificity for a biopsy proven GCA

Imaging in diagnosis, monitoring and outcome prediction of large vessel vasculitis: a systematic literature review and meta-analysis informing the 2023 update of the EULAR recommendations

“…Similar results for ultrasound were also found when using TAB as the reference standard. Five studies from the update (1 low, 29 4 moderate RoB 18 24 27 28 and 10 studies) from the previous SLR (1 low, 60 1 moderate, 54 8 high RoB), 55–59 61–63 including 1126 participants, were analysed. These revealed pooled sensitivities of 73% (95% CI 61% to 83%) and specificities of 84% (95% CI 74% to 90%).…”