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 19months [range: 5-162months] and 17months [range: 6-168months] 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: 1.34-7.48], p=0.009). CONCLUSIONS: LVI represents a distinct disease pattern of GCA with an increased risk of aortic dilation. Control of the aortic morphology during follow-up is required.