Aortic disease in giant cell arteritis

The increasing use of non-invasive vascular imaging has allowed for improved detection of aortic disease in patients with vasculitis. Indeed, up to 70 % of patients have radiographic evidence of aortitis at GCA onset and aortic dilatation is already identified in about 15 %. Aortic inflammation is generally diagnosed by imaging studies such as CT angiography, MR angiography or FDG-PET, and occasionally by histopathology following resection of the aorta for aneurysm repair. Aortic inflammation may be clinically silent but is a risk factor for progressive aortic dilatation and aneurysm formation in GCA. By comparison, aortitis in Takayasu arteritis may lead to aortic dilatation or stenosis, particularly in the descending thoracic and abdominal aorta. The risk of thoracic aortic aneurysm in patients with GCA has been estimated to be up to 17-fold higher than that of the general population, with up to 1/3 of patients developing aortic aneurysm at 10 years of follow-up. Moreover, chronic smoldering aortitis may be refractory to current therapy, lasts for several years and contributes to progressive aortic dilatation. A rare but life-threatening complication of GCA-associated aortic disease is dissection or rupture. Observational studies are informing outcomes and management of inflammatory aortic aneurysms, while transcriptomic and molecular studies on aortic tissue are yielding important information regarding disease pathogenesis. These endeavors are critical to reducing the excess mortality related to aortic disease in GCA. Also, improved understanding of the pathophysiology of the disease is allowing the development of non-glucocorticoid targeted therapies.