Large-vessel involvement in giant cell arteritis: a population-based cohort study of the incidence-trends and prognosis

Objectives To evaluate incidence-trends and timing of large-vessel (LV) manifestations in patients with giant cell arteritis (GCA), and to examine the influence of LV manifestations on survival. Methods A population-based incident cohort of patients diagnosed with GCA between 1950 and 2004 was used. LV involvement was defined as large-artery stenosis or aortic aneurysm/dissection that developed in the 1year before GCA diagnosis or at any time thereafter. Patients were followed up until death or 31 December 2009. Results The study included 204 patients, 80% women, mean age at diagnosis of GCA 76.0years (8.2years). Median length of follow-up was 8.8years. The cumulative incidence of any LV manifestation at 10years was 24.9% for patients diagnosed with GCA between 1980 and 2004 compared with 8.3% for patients diagnosed with GCA between 1950 and 1979. The incidence of any LV event was high within the first year of GCA diagnosis. The incidence of aortic aneurysm/dissection increased 5years after GCA diagnosis. Compared with the general population, survival was decreased in patients with an aortic aneurysm/dissection (standardized mortality ratio (SMR) 2.63; 95% CI 1.78 to 3.73) but not in patients with large-artery stenosis (SMR 1.44; 95% CI 0.87 to 2.25). Patients with GCA and aortic manifestations had a higher than expected number of deaths from cardiovascular and pulmonary causes than the general population. Among patients with GCA, aortic manifestations were associated with increased mortality (HR=3.4; 95% CI 2.2 to 5.4). Conclusions Vigilance and screening for aortic aneurysms should be considered in all patients 5years after the incidence of GCA. Aortic aneurysm/dissection is associated with increased mortality in GCA.