Authors: K. Bates Gribbons, Cristina Ponte, Anthea Craven, Joanna C. Robson, Ravi Suppiah, Raashid Luqmani, Richard Watts, Peter A. Merkel, Peter C. Grayson
Published: 2019-11-15
DOI: 10.1002/art.41165
Source: Full article
ObjectiveDiagnostic assessment in giant cell arteritis (GCA) is rapidly changing as vascular imaging becomes more available. This study was undertaken to determine if clinicalGCAsubsets have distinct profiles or reflect differential diagnostic assessments.MethodsPatients were recruited from an international cohort and divided into 4 subsets based on a temporal artery (TA) abnormality (positiveTAbiopsy [TAB] or halo sign onTAultrasound [TA‐US]) and/or evidence of large vessel (LV) involvement on imaging: 1) bothTAabnormality andLVinvolvement (TA+/LV+GCA); 2)TAabnormality withoutLVinvolvement (TA+/LV−GCA); 3)LVinvolvement withoutTAabnormality (TA−/LV+GCA); and 4) clinically diagnosedGCAwithoutLVinvolvement orTAabnormality (TA−/LV−GCA).ResultsNine hundred forty‐one patients withGCAwere recruited from 72 international study sites. Most patients received multiple forms of diagnostic assessment, includingTAB(n = 705 [75%]),TA‐US(n = 328 [35%]), andLVimaging (n = 534 [57%]). Assessment usingTAB,TA‐US, andLVimaging confirmed the diagnosis ofGCAin 66%, 79%, and 40% of cases, respectively.GCAsubsets had distinct profiles independent of diagnostic assessment strategies.TA+/LV− were the most common subset (51%), with a high burden of cranial ischemia. Those in theTA−/LV− subset (26%) had a high prevalence of cranial ischemia and musculoskeletal symptoms. Patients in theTA−/LV+ subset (12%) had prevalent upper extremity vascular abnormalities and a low prevalence of vision loss, and those in theTA+/LV+ subset (11%) were older and had a high prevalence of cranial ischemia, constitutional symptoms, and elevated acute‐phase reactant levels.ConclusionVascular imaging is increasingly incorporated into the diagnostic assessment ofGCAand identifies clinical subsets of patients based on involvement of temporal and extracranial arteries.