Large vessel vasculitis is a risk factor for relapse only in giant cell arteritis patients without polymyalgia rheumatica.

Abstract

To evaluate differences in presentation and outcome of GCA patients with and without large vessel vasculitis (LVV) and according to the extent and severity of LVV. Consecutive patients diagnosed with GCA between 2003 and 2020 who have had FDG PET imaging at diagnosis ≤3 days after initiation of glucocorticoids (GC) and followed for ≥12 months at the University Hospitals Leuven (Belgium) were included retrospectively. PET scans were visually scored (0-3) in seven vascular areas and a total vascular score (TVS) was calculated. LVV was defined as FDG uptake ≥2 in any large vessel. We included 238 GCA patients, of which 169 (71%) had LVV. LVV patients were younger (69 vs 74 years, P < 0.001) and more frequently female (72% vs 49%, P = 0.001). In patients without PMR symptoms, the presence of LVV was associated with relapse (aOR 3.05 [95% CI 1.32-7.43], P = 0.011) and with a lower probability of stopping GC (aHR 0.59 [95% CI 0.37-0.94], P = 0.025). However, in those with PMR symptoms, there was no difference in relapse risk (aOR 1.20 [95% CI 0.53-2.66], P = 0.657) and in the probability of stopping GC (aHR 1.25 [95% CI 0.75-2.09], P = 0.394) between patients with and without LVV. A higher TVS was associated with an increased risk of relapse (aOR 1.09 [95% CI 1.04-1.15], P = 0.001) in patients without PMR symptoms, but not in those with PMR symptoms (aOR 1.01 [95% CI 0.96-1.07], P = 0.693). LVV is a risk factor for relapse in GCA patients without PMR symptoms with a higher relapse risk in those with higher TVS.