Large-vessel involvement and aortic dilation in giant-cell arteritis. A multicenter study of 549 patients

{Objectives: Large-vessel involvement (LVI) can occur in giant-cell arteritis (GCA) and may represent a distinct disease subgroup with a higher risk for aortic dilation. This study aimed to better characterize the presentation and evolution of LVI in patients with GCA. Patients and methods: A retrospective multicenter study enrolled 248 GCA patients with LVI and 301 GCA patients without LVI on imaging. Factors associated with aortic dilation were identified in a multivariable model. Results: The patients with LVI were younger (p < 0.0001), more likely to be women (p = 0.01), and showed fewer cephalic symptoms (p < 0.0001) and polymyalgia rheumatica (p = 0.001) but more extracranial vascular symptoms (p = 0.05) than the patients without LVI. Glucocorticoids (GC) management did not differ between the two groups, but the GC discontinuation rate was lower in the patients with LVI (p = 0.0003). Repeated aortic imaging procedures were performed at 19 months [range: 5-162 months] and 17 months [range: 6-168 months] after diagnosis in 154 patients with LVI and 123 patients without LVI, respectively, of whom 21% and 7%, respectively, presented new aortic dilations (p = 0.0008). In the patients with LVI, aortic dilation occurred on an aorta segment shown to be inflammatory on previous imaging in 94% of patients. In the multivariate analysis, LVI was the strongest predictor of aortic dilation (hazard ratio: 3.16 [range: 134-7.48]