Prevalence and prognostic factors for aortic dilatation in giant cell arteritis - a longitudinal study

Predictive data for the development of aortic dilatation (AD) in giant-cell arteritis (GCA) are controversial. The aim was to investigate by computed tomography (CT) the prevalence of AD in a consecutive cohort of GCA patients and controls, and to identify possible predictors for AD.

GCA patients and controls were identified by electronic search and underwent aortic contrast enhanced CT defining AD by aortic diameter adjusted to age, gender and body surface area. Pulse-wave velocity, intima-media thickness (IMT) and laboratory studies including lymphocyte subsets were conducted identifying potential factors associated with AD. Clinical and laboratory parameters at disease onset, occurrence of aortic rupture/dissection before and up to five years after study visit were retrieved by chart review.

144 GCA patients and 115 controls were included. GCA patients developed more frequently AD of the ascending and thoracic descending aorta compared to controls (OR 2.60, p = 0.016; OR 3.65, p = 0.005, respectively). Factors associated with AD development of thoracic descending aorta, but not of the ascending aorta, were higher percentages of circulating CD3+CD4+ cells, higher CD4/CD8 ratio, presence of polymyalgia rheumatica and increased carotid IMT at disease onset (OR range 1.10-3.11, all with p < 0.05). During follow-up, no GCA patient required surgical aortic repair or suffered aortic rupture/dissection.

Thoracic but not abdominal ADs occur more commonly in GCA patients, however, the subsequent risk for aortic repair, rupture or dissection is low. Changes of T-cell subsets, presence of polymyalgia rheumatica and increased carotid IMT at disease onset are associated with AD development.