Thus, the aims of this paper are: (1) to evaluate the circulating EMP levels—namely CD31+/42− (PECAM-1), CD144 (VE Cadherin), and CD62e (E-selectin)—in combination with annexin V labelling in a hypercholesterolemia cohort representing patients with endothelial dysfunction; and (2) to assess the relationship between EMP and EDV as assessed via PWA, which is an established method of assessing endothelial function. This evidence concerns the gene PECAM1 and endothelial dysfunction.