Aortic dilatation in patients with large vessel vasculitis: A longitudinal case control study using PET/CT

Area of Science:

• Cardiovascular Imaging
• Rheumatology
• Nuclear Medicine

Background:

• Large vessel vasculitis (LVV) is an inflammatory condition affecting major arteries.
• Aortic dilatation is a serious complication of LVV, but predictors require further investigation.
• ¹⁸FDG-PET/CT is a valuable tool for assessing vascular inflammation.

Purpose of the Study:

• To evaluate aortic diameter changes and identify predictors of aortic dilatation in LVV patients using ¹⁸FDG-PET/CT.
• To compare aortic dimensions and dilatation risk between LVV patients and a control group.
• To explore the relationship between FDG uptake and aortic dilatation in LVV.

Main Methods:

• Longitudinal follow-up of 93 LVV patients and 29 lymphoma controls with at least two ¹⁸FDG-PET/CT scans.
• Radiological and nuclear medicine assessment of aortic diameter and FDG uptake at four levels.
• Statistical analysis to identify predictors of aortic dilatation, including sex, hypertension, and FDG uptake grade.

Main Results:

• LVV patients exhibited significant increases in ascending, descending thoracic, and suprarenal abdominal aorta diameter over a median of 31 months.
• Aortic dilatation was more frequent in LVV patients (19%) compared to controls (3%).
• Male sex (OR 7.27) and hypertension in GCA patients (OR 6.30) were significant predictors of aortic dilatation. High FDG uptake (grade 3) in GCA patients correlated with larger aortic diameters.

Conclusions:

• Patients with LVV have an elevated risk of aortic dilatation compared to controls.
• Male sex and hypertension (specifically in GCA) are key predictors of aortic dilatation in LVV.
• Elevated aortic FDG uptake on initial PET/CT in GCA patients signifies a heightened risk for subsequent aortic dilatation.