12.7 THE RELATIONSHIP BETWEEN FUNCTIONAL ARTERIAL RESPONSE AND CIRCULATING BIOMARKERS OF PATIENTS WITH FIBROMUSCULAR DYSPLASIA

Abstract

Background: Fibromuscular dysplasia (FMD) is a rare idiopathic, non-atherosclerotic non-inflammatory vascular disease. This work represents the first study of the pathophysiology of FMD. We investigated the relationships between circulating biomarkers and the non-invasive vascular parameters. Methods: We included 50 patients with FMD, 50 essential hypertensive patients (HT) and 50 healthy subjects (NT) matched for age, sex, ethnicity and blood pressure. We determined circulating levels of total microparticles (MPs) (annexinV+MPs), endothelial MPs (CD144+MPs, CD62E+MPs and CD31+CD41-MPs) and SMC-MPs by flow cytometry analysis. We measured forearm endothelial function by post-ischemic flow dependent vasodilation. Shear stress was estimated using the formula of Weaver (1–3). Aortic stiffness was assessed by measuring carotid-femoral pulse wave velocity. Triple signal score was assessed from 15-MHz echotracking system. Results: There are no significant differences between rates of total MPs, endothelial MPs (CD144+MPs, CD62E+MPs and CD31+CD41-MPs) and SMC-MPs between 3 groups (with p-value 0.38 0.52 0.65 0.17 and 0.25 respectively). Endothelial MPs were not correlated with the endothelial dysfunction, nor with the shear stress, whether in FMD, NT or HT. We observed a strong negative correlation between aortic stiffness and nitroglycerin-mediated dilation in the group NT, HT and whole population (r= −0.43, p= 0.001 r= −0.29, p= 0.03 r = −0.35, p<0.001 respectively), but not in FD (p=0.5). SMC-MPs were not associated with the triple signal or any arterial parameter in the group FMD nor in the whole population. Conclusions: The number of MPs was not correlated with large artery properties. Arterial stiffness is negatively related to endothelium-independent dilatation.