Risk Factors for Thrombotic Events in Systemic Lupus Erythematosus Patients with Antiphospholipid Antibodies: Insights from Morphometric Measurements of Carotid Arteries Provisionally Accepted

Qing Yang¹ Qi Liu² Changqing Yin¹ Xiaoyu Zhang² Xi Chen³ Dmytro Pylypenko⁴ Hao Chen⁵ Qiang Shu^2* Dexin Yu^1*

• ¹Department of Radiology, Qilu Hospital, Shandong University, China
• ²Department of Rheumatology, Qilu Hospital, Shandong University, Department of Rheumatology, Qilu Hospital, Shandong niversity, China
• ³Department of Orthopaedics, Peking University Third Hospital, China
• ⁴GE Healthcare, MR Research China, China
• ⁵Clinical Epidemiology Unit, Clinical Research Center of Shandong University, Qilu Hospital, Shandong University, China

Objective: To identify the correlation between thrombosis and atherosclerosis in systemic lupus erythematosus (SLE) patients with antiphospholipid antibodies (aPLs) (SLE/aPLs) through highresolution magnetic resonance imaging (HR-MRI) of the carotid artery.Methods: A single-center, cross-sectional study was conducted. We collected consecutive patients with SLE/aPLs and healthy controls who underwent carotid HR-MRI examinations. The morphometric characteristics of the common carotid artery (CCA), internal carotid artery (ICA), external carotid artery (ECA), and carotid bulb (Sinus) were measured, and the differences in morphometric parameters between different groups were analyzed. Results: A total of 144 carotid arteries were analyzed. Compared with the control group, the wall area, wall thickness (WT and WTmax), and normalized wall index of CCA, ICA, ECA, and Sinus were increased in patients with SLE/aPLs, and the total vascular area (TVA) of CCA, ICA, and Sinus, and the bifurcation angle (BIFA) of ICA-ECA were also increased. A negative lupus anticoagulant (LAC) (with or without positive anticardiolipin antibody (aCL) or anti-β2glycoprotein antibody (aβ2GPI)) contributed to illustrating lower increased TVA and thickened vessel walls of CCA and ICA in SLE/aPLs patients without thrombotic events. Logistic regression analysis showed that WTmaxSinus and WTmaxGlobal were independent risk factors for thrombotic events in SLE/aPLs patients. The receiver operator characteristic curve showed that the cut-off value of WTmaxSinus was 2.855 mm, and WTmaxGlobal was 3.370 mm. Conclusion: HR-MRI ensures the complete and accurate measurement of carotid morphometric parameters. Compared with the control group, the carotid artery in patients with SLE/aPLs is mainly characterized by diffusely thickened vessel walls, increased vascular area of CCA and ICA, and increased BIFA of ICA-ECA without significant change in lumen area. LAC-negative and nonthrombotic events distinguish relatively early atherosclerosis in the carotid arteries in patients with SLE/aPLs. Patients with SLE/aPLs that possess circumscribed thickened carotid vessel walls (> 3.370 mm), particularly thickened at the Sinus (> 2.855 mm), may require management strategies for the risk of thrombotic events.