Abstract 12593: Improvement in Aortic Vascular Inflammation by 18-FDG PET/CT Associates With Reduction in Aortic Wall Thickness by MRI

Abstract

Introduction: The presence of aortic vascular inflammation (VI) by 18-FDG PET/CT predicts future cardiovascular (CV) events. Furthermore, aortic wall thickness by MRI has been shown to be an important marker of early subclinical atherosclerosis. Whether improvement in aortic vascular inflammation by FDG PET/CT is associated with improvement in aortic wall thickness by MRI is not known. Hypothesis: We hypothesized that an improvement in VI by FDG PET/CT will associate with an improvement in aortic wall thickness by MRI in a well characterized cohort of Psoriasis (PSO) patients. Methods: Consecutively recruited PSO patients (N=64) underwent whole-body PET/CT and MRI exams at baseline and 1-year follow-up. VI was assessed as target-to-background ratio (TBR) [Excellence Brilliant Workstation]. To measure aortic wall thickness, wall boundaries of the thoracic descending aorta were traced on each MRI slice [Qplaque, Medis]. The longitudinal change in wall thickness of the thoracic descending aorta was analyzed using unadjusted and adjusted multivariable regression (STATA 12). Results: The cohort was middle-aged (mean±SEM 50.67±1.80) and had a low cardiovascular risk by Framingham risk score [median-3, IQR- (1-7)]. Overall the cohort had an average TBR of 1.74±0.02 consistent with moderate vascular inflammation. At follow-up, the total cohort had a mean improvement in TBR of 7.47% (p<0.001) with use of topical therapy (64%), biological therapy (59%) and UVB (13%). Improvement in TBR of the aorta was associated with reduction in mean wall thickness of the descending thoracic aorta beyond adjustment for traditional risk factors, statin use, & systemic/biologic PSO therapy (β=0.30, p = 0.03). Conclusions: Improvement in aortic VI by FDG PET/CT was associated with reduction in aortic wall thickness by MRI at one year, suggesting a reduction in VI may improve early atherosclerosis. Our findings suggest that an improvement in vascular inflammation may mitigate structural abnormalities of the aorta. Randomized controlled studies are needed to confirm these findings.