THU0296 CORRELATIONS AMONG VASCULAR ULTRASOUND ABNORMALITIES OF THE TEMPORAL AND LARGE ARTERIES IN GIANT CELL ARTERITIS
Authors: Michael Diiorio, Piotr Sobieszczyk, Julia Ford, William Docken, Sara Tedeschi
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Vascular ultrasound (VUS) is a sensitive and specific method for evaluating giant cell arteritis (GCA). Understanding patterns of temporal artery (TA) and large artery involvement may be important for aiding in diagnosis. <h3>Objectives</h3> To determine correlations among VUS abnormalities in patients with GCA. <h3>Methods</h3> We performed a retrospective study among 503 patients that underwent VUS to evaluate suspected or known GCA at an academic medical center, 2013-2017. Demographics, clinical features, VUS reports, and pathology data were extracted through electronic medical record review. Trained cardiovascular ultrasonographers imaged the right and left temporal, common carotid (CCA), subclavian (SCA), and axillary (AXA) arteries. The superficial temporal arteries (STA) and their frontal (TA-F) and parietal (TA-P) branches were abnormal if halo sign or hyperechoic wall thickening was present; the CCA, SCA and AXA were abnormal if those findings and/or stenosis or occlusion were present. Cardiovascular medicine physicians trained in VUS interpreted studies as acute arteritis, no arteritis, or hyperechoic wall thickening without acute arteritis. Among patients diagnosed with GCA by the treating physician (n=139), we determined correlations between abnormal vessels using phi coefficients (φ). We created composite variables representing each TA and its branches, and the left and right CCA, SCA, and AXA to test correlations between temporal and large arteries. Significance was determined using Fisher's exact test with Bonferroni correction. <h3>Results</h3> Among 139 patients, 50% were diagnosed before VUS (median disease duration 17 months). Median age at VUS was 73 years; 75% were female and 93% White. Forty patients (29%) had TA biopsy-proven GCA; an additional 14 (10%) had biopsy-proven giant cell aortitis. Prevalence of abnormalities of TAs and large arteries were similar (20% of right and 27% of left TAs; 20% of right and 24% of left large arteries). VUS was consistent with acute arteritis in 32%, no arteritis in 53%, and hyperechoic without acute arteritis in 15%. Abnormalities in the STA, TA-F, and TA-P were moderately correlated ipsilaterally (φ = 0.46-0.62, p&lt;0.0001) and contralaterally (φ = 0.51-0.58, p&lt;0.0001) (Table). Abnormalities in the AXA and SCA were strongly correlated with the ipsilateral and contralateral AXA and SCA (φ = 0.64-0.82, p&lt;0.0001). Correlation between right and left TAs was moderate (φ = 0.59, p&lt;0.0001), while a stronger relationship was found between right and left large arteries (φ = 0.77, p&lt;0.0001). Abnormalities in TAs were not correlated with large arteries (φ ≈ 0 for all comparisons; not significant). <h3>Conclusion</h3> We observed moderate correlations of TA branches and strong correlations of large artery branches on VUS among GCA patients. Abnormalities in the TAs and large arteries were not correlated, underscoring the importance of scanning both groups of vessels with VUS. Temporal composite: abnormal superficial TA, TA-frontal branch, and/or TA-parietal branch. Large composite: abnormal common carotid, subclavian, and/or axillary artery. NS: not significant † p&lt;0.0001 <h3>Disclosure of Interests</h3> None declared