Incidence and predictors of thoracic aortic damage in biopsy-proven giant cell arteritis

Objective: To describe the frequency and predisposing factors of aortic structural disease among patients with biopsy-proven giant cell arteritis (GCA).Method: A retrospective review identified all patients with biopsy-proven GCA from 1998 to 2013 with aortic imaging. Kaplan-Meier methods were used to estimate cumulative incidence and Cox models were used to examine potential predictors of development of aneurysm/dilatation of the thoracic aorta.Results: The cohort included 114 patients with aortic imaging performed within a median time of 1.8 months from GCA diagnosis. Fifty-seven patients (50%) had at least one additional follow-up imaging study. At the first imaging study, 8% had evidence of aneurysm/dilatation and 25% thickening of the thoracic aorta. Excluding prevalent cases, the cumulative incidence for aneurysm/dilatation of the thoracic aorta during follow-up was 0% at both 1 year and 2 years but increased to 10% at 5 years. The sole predictor for development of thoracic aortic aneurysm/dilatation was current smoking (hazard ratio 28.8, 95% confidence interval 1.62, 511.4; p = 0.02).Conclusion: Thoracic aortic aneurysm/dilatation was seen in 8% of patients at baseline. Among patients without aortic disease, the cumulative incidence of aortic disease was 10% at 5 years after diagnosis. Current smokers were at an increased risk for developing thoracic aortic damage. Surveillance for aortic damage should be pursued in patients with GCA, particularly those with a smoking history.