Prevalence of ischemic complications in patients with giant cell arteritis presenting with apparently isolated polymyalgia rheumatica.

OBJECTIVE: To investigate the frequency and type of giant cell arteritis (GCA)-related ischemic complications in a series of patients with GCA who, for a substantial period of time (i.e., at least 3 mo), lacked vascular symptoms and presented with apparently isolated polymyalgia rheumatica (PMR). METHODS: Retrospective follow-up study of an unselected population of 167 patients with GCA diagnosed from 1985 to 2014. RESULTS: In all, 18 patients (11%) developed GCA on a background of a prior history of PMR. They were diagnosed as having isolated PMR because they did not have clinical evidence of GCA at diagnosis and exhibited a prompt and complete response to low-dose steroid therapy. However, during the course of treatment, 17 patients later experienced an arteritic relapse with the development of typical craniofacial symptoms, and one patient developed signs of upper extremity vascular insufficiency, resulting in the diagnosis of large-vessel GCA. The median time to GCA diagnosis from the initiation of low-dose steroid therapy was 9 ± 14.4 mo (range: 3-39). At the time of GCA diagnosis, severe ischemic complications were observed in 50% (9/18) of the patients. Of these patients 22% (4/18) were considered to have "true" occlusive disease (i.e., permanent visual loss, stroke, and/or limb claudication). Late inflammation of the aorta and its branches occurred in 4 (22%) of the patients during long-term follow-up. CONCLUSION: Patients with GCA presenting with apparently isolated PMR have a significant risk of developing transient or permanent disease-related ischemic complications; these complications occurred in 50% of the cases.