Accumulation of Microvascular Target Organ Damage in Systemic Lupus Erythematosus Patients is Associated with Increased Cardiovascular Risk.

Background: Systemic lupus erythematosus (SLE) is a prototype autoimmune disease associated with increased cardiovascular (CV) burden. Besides increased arterial stiffness and subclinical atherosclerosis, microvascular dysfunction is considered an important component in the pathophysiology of CV disease. However, there is a lack of data regarding the effect of multiple target organ damage (TOD) on CV health. Objectives: This study aimed to evaluate (i) the presence of microvascular changes in SLE in various vascular beds, (ii) the possible associations between the accumulation of microvascular TOD and CV risk and (iii) whether Galectin-3 represents a predictor of combined microvascular TOD. Methods: Participants underwent (i) evaluation of skin microvascular perfusion (laser speckle contrast analysis), (ii) fundoscopy (non-mydriatic fundus camera), (iii) indirect assessment of myocardial perfusion (subendocardial viability ratio) and (iv) determination of urine albumin-to-creatinine ratio (UACR). CV risk was calculated using the QResearch Risk Estimator version 3 (QRISK3). Serum Galectin-3 levels were determined. Results: Forty-seven SLE patients and fifty controls were studied. SLE patients demonstrated impaired skin microvascular reactivity (160.2 ± 41.0 vs. 203.6 ± 40.1%), retinal arteriolar narrowing (88.1 ± 11.1 vs. 94.6 ± 13.5 μm) and higher UACR levels compared to controls. Furthermore, SLE individuals had significantly higher Galectin-3 levels [21.5(6.1) vs. 6.6(6.6) ng/dL], QRISK3 scores [7.0(8.6) vs. 1.3(3.6)%] and a greater chance for microvascular dysfunction. In the SLE group, patients with multiple TOD exhibited higher QRISK3. In the multivariate analysis, the accumulation of TOD correlated with disease activity and Galectin-3 (p < 0.05). Conclusions: Our study showed for the first time that SLE patients exhibit a greater number of cases of TOD. The accumulation of TOD was associated with increased CV risk. Clinicians dealing with SLE should be aware and seek microvascular alterations.