Mortality in Patients with Biopsy-proven Giant Cell Arteritis: A South Australian Population-based Study

Abstract

To compare mortality rates and cause of death in patients with biopsy-proven giant cell arteritis (GCA) with those in the general population. Patients with biopsy-proven GCA were identified from pathology reports of temporal artery biopsies in South Australia, from January 1, 1992, to December 31, 2006. All patients with biopsy-proven GCA were linked to the South Australian Births, Death and Marriage Registry to identify deaths until December 31, 2006. Standardized mortality ratios and relative survival (ratio of observed survival in GCA group to expected survival of general South Australian population, matched by age, sex, and calendar time) were calculated. The cause of death recorded on the death certificate was also documented. There were 225 cases of biopsy-proven GCA (163 women and 62 men). The mean age at diagnosis of GCA was 78.2 years. The mean followup period was 66.2 months (SD 47.1 mo). During the followup period, there were 71 deaths in the GCA group (50 women, 21 men). The standardized mortality ratio was 0.99 (95% CI 0.77-1.25). The relative survival for different followup periods demonstrates that patients with GCA experienced similar mortality to the general population (age-matched and sex-matched). Death from cardiovascular causes (45%) was the most common, followed by infection (17%) and cancer (17%). Infection was a significantly more common cause of death in the first year (chi-squared, p = 0.0002). Our population-based cohort study did not demonstrate any increased mortality risk for patients diagnosed with biopsy-proven GCA. The risk of death from infection early in the disease may be increased.