Risk of ischaemic events at giant cell arteritis diagnosis according to PET/CT findings

Purpose: To analyse the risk of ischaemic events in patients with newly diagnosed giant cell arteritis (GCA) according to PET/CT findings.

Methods: PET/CT was performed during the first 10 days of steroid therapy. Clinical manifestations at diagnosis, and physical examination and PET/CT findings were recorded and compared according to the presence or absence of ischaemic symptoms at disease onset. Analysed territories included the ascending aorta, aortic arch, descending aorta, abdominal aorta, carotid arteries, brachiocephalic trunk, vertebral arteries, subclavian arteries and axillary arteries.

Results: The study group comprised 30 patients with a median age of 80.8 years. Of these patients, 21 (70%) reported ischaemic symptoms at diagnosis, and 13 (43.3%) had permanent visual loss. Of the 30 patients, 77.8% showed large vessel vasculitis (including aortic and vertebral artery involvement) on PET/CT, and 60% had isolated involvement of the vertebral territory. Vertebral arteries were more frequently involved in patients with ischaemic symptoms (OR 5.0, 95% CI 0.99-24.86, p = 0.051). The presence of vertebral artery involvement in the absence of aortic involvement was associated with the presence of ischaemic manifestations (Fisher's exact test, p = 0.001). The presence of aortitis was found to protect against the development of permanent visual loss (OR 19.0, 95% CI 2.79-127.97, p = 0.001).

Conclusion: Our findings suggest an association between the vascular pattern on PET/CT at the time of GCA diagnosis and the risk of ischaemic events.