Background GCA is the most frequent vasculitis in patients over 50 years old. It involves large vessels (LV) such as aorta, carotid, vertebral and subclavian arteries. After the development of new imaging techniques, extracranial LV involvement has been increasingly described. Past studies showed a trend in worse prognosis in those patients with aortitis at diagnosis but larger studies are needed to determine the clinical implications of these results. Correlation between symptoms at diagnosis and PET evaluation has not been done.
Objectives To evaluate aortic and supraaortic involvement in a new onset GCA cohort through PET/CT. To compare aortic and supraaortic involvement in patients with and without cranial ischemic symptoms.
Methods Prospective study including all newly diagnosed biopsy-proven GCA patients in 2016 according to ACR criteria. PET/CT was performed during initial evaluation. Clinical data, blood tests and PET/CT results were recorded. Ischemic symptoms included jaw claudication (JC) and visual symptoms. Analysis was made using Stata IC/14. Patients were compared according to clinical presentation (presence vs absence of ischemic symptoms) with Fisher exact test.
Results 18 patients were included (63.6% were women). At diagnosis age was 77.4±8.7 years (mean ± SD). Patients presented headache (78.6%), polymyalgia rheumatica (14.3%), constitutional syndrome (42.8%), JC (42.9%) and visual symptoms (35.7%). On physical examination pulse was decreased in 78.6% of patients. Blood tests showed anemia in 71.4% with an ESR 90.41±33mm/h (mean ± SD). PET/CT was performed after (median, intercuartilic range) 6.5 days (2 - 10 days). Analysis of vascular uptake was semiquantitative. Aortic involvement was present in 42.9% of patients. Supraaortic and vertebral arteries were involved in 42.8%. Baseline characteristics were similar to other cohorts. At the time of diagnosis, proportion of aortitis was significantly lower (p=0.049) in patients with ischemic symptoms when compared to those without. We could not find any differences between these two groups when analyzing the presence of increased vascular uptake in carotid and vertebral arteries. Limitations of the study are the small size of the cohort and the variability of the PET/CT protocols among literature. However, we think this study is important because it shows the differences between these two subgroups of GCA.
Conclusions In this study, patients with cranial ischemic symptoms showed less involvement of large vessels when compared to those GCA patients that presented with systemic symptoms. These results suggest that there may be different physiopathological subsets leading to GCA. Further studies are needed to better understand these mechanisms.
Disclosure of Interest None declared