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

Objectives: 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.

Methods: 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.

Results: 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.

Conclusions: 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.