Epidemiology of major and minor relapses in giant cell arteritis according to EULAR definitions: Insights from the ARTESER registry

Abstract

Objective To investigate the prevalence, timing and risk factors at diagnosis associated with relapses in giant cell arteritis (GCA), with a separate analysis of major and minor relapses. Methods A retrospective review of patients from the Spanish multicentre GCA registry (ARTESER) was conducted. Relapses were classified using 2018 EULAR definitions. Results We included 1284 patients with at least one year of follow-up. Twenty-six percent experienced relapses, with cumulative rates of 18.1%, 27.9%, 37.6% and 44.8% at 1, 2, 3 and 4 years, respectively. Multiple relapses were observed in 14.6% of patients during the first year, 10.5% in the second, 9% in the third and 17.8% in the fourth, reflecting the relapsing-remitting nature of GCA. According to EULAR definitions, major relapses represented 26.7% of all recorded relapses and affected 7.6% of patients. Younger age at diagnosis (HR: 0.976, P = 0.004) and a higher total dose of prednisone at the first relapse (HR: 0.998, P = 0.003) were associated with a reduced risk of overall relapses. Severe ischemic complications (HR: 4.126, P < 0.001) and large-vessel (LV) involvement at diagnosis (HR: 1.992, P = 0.024) significantly increased the risk of major relapses, while younger age (HR: 0.970, P = 0.002) was protective against minor relapses. Conclusions Major relapses are not so uncommon, representing a quarter of all relapses. The presence of severe ischemic complications and LV involvement at diagnosis substantially increase their risk.