Prior polymyalgia rheumatica is associated with sonographic vasculitic changes in newly diagnosed patients with giant cell arteritis

Objectives: To investigate the hypothesis that a history of PMR is associated with a more severe and damaging disease course in newly diagnosed GCA patients.

Methods: This was a retrospective analysis of GCA patients diagnosed between December 2006 and May 2021. We compared vascular ultrasound findings (presence of vasculitis and vascular stenosis) in GCA patients with and without prior PMR.

Results: Forty-nine of 311 GCA patients (15.8%) had prior PMR in a median of 30.6 (IQR 7.1-67.3) months before GCA diagnosis. Patients with prior PMR more often had large vessel vasculitis (LVV) (51.0% vs 25.0%, P < 0.001) and stenosis within the vasculitic segments (18.4% vs 3.1%, P < 0.001) on ultrasound. In multivariable analysis, prior PMR remained significantly associated with LVV (odds ratio 7.65, 95% CI: 2.72, 23.97, P < 0.001). Polymyalgic symptoms at GCA diagnosis in the patients without prior PMR were not associated with a higher prevalence of LVV (P = 0.156).

Conclusion: Patients with a diagnosis of PMR before GCA diagnosis had two times more often large vessel involvement and significant more vasculitic stenoses on ultrasound examination than patients without prior PMR. Pre-existing PMR is an independent risk factor for more extensive and advanced ultrasound findings at GCA diagnosis. The contribution of subclinical vasculitis to disease associated damage should be further studied.