High-Frequency Ultrasound of Multiple Arterial Areas Reveals Increased Intima Media Thickness, Vessel Wall Appearance, and Atherosclerotic Plaques in Systemic Lupus Erythematosus

Introduction: Despite improved therapies and management, patients with systemic lupus erythematosus (SLE) still have increased risks of cerebrovascular and cardiovascular disease. High-frequency ultrasound (US) provides an opportunity to distinguish atherosclerosis from inflammation in the vessels. We hypothesized that an extended US protocol may add information regarding vascular affection in SLE. Methods: Sixty patients (52 women, 8 men; mean age 43.2 ± 11.3 years) with SLE characterized by either lupus nephritis (LN; n = 20), antiphospholipid syndrome (APS; n = 20), or skin and joint involvement (n = 20) as well as matched healthy controls (n = 60) were included. Intima-media thickness (IMT), assessment of vessel walls, and plaque occurrence were recorded using high-frequency US (GE Logic E9) in common carotid, internal carotid, brachiocephalic, subclavian, axillary, common femoral, and proximal superficial femoral arteries as well as in the aortic arch. Results: For the entire SLE group, IMT was increased in the internal carotid artery (0.52 ± 0.17 vs. 0.45 ± 0.09 mm, p = 0.004), the common femoral artery (0.57 ± 0.23 vs. 0.49 ± 0.11 mm, p < 0.01), the subclavian artery (0.58 ± 0.19 vs. 0.53 ± 0.13 mm, p = 0.02), and the aortic arch (1.21 ± 0.63 vs. 0.98 ± 0.25 mm, p = 0.002) compared to controls. These differences were primarily observed in the APS and LN groups compared to controls. Vessels with increased IMT ≥0.9 mm had a smooth, medium echogenic appearance in areas free of atherosclerotic plaques. Atherosclerotic plaques were detected in 15/60 patients (25%) as compared to 2/60 of the controls (3%). Plaques were predominantly (67%) located in the carotid bifurcation. Multivariate analysis revealed influence of age on IMT in all vessel areas. Furthermore, in the common femoral artery, sagittal abdominal diameter, diastolic blood pressure, and cholesterol all showed association with increased IMT. In the internal carotid artery, male sex and presence of Raynaud phenomenon influenced IMT. Conclusion: Among SLE patients without presence of plaques, an extended US protocol revealed increased wall thickness with predominantly medium echogenic appearance highlighting possibly inflammation or early atherosclerosis. The appearance of vessel walls has not previously been studied in detail. An increased number of plaques were found in SLE compared to age- and sex-matched healthy controls. We found similar risk factors for increased IMT and occurrence of plaques, possibly indicating atherosclerotic mechanisms rather than inflammation.