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 1 year 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 76.0 years (±8.2 years). Median length of follow-up was 8.8 years. The cumulative incidence of any LV manifestation at 10 years 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 5 years 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 5 years after the incidence of GCA. Aortic aneurysm/dissection is associated with increased mortality in GCA.