EDN1 and endothelial dysfunction: Moorhouse et al. [34] suggested that endothelial dysfunction presenting a reduced release of endothelium-derived relaxation factors such as NO, and the increased release of endothelial-derived contractility factors such as endothelin-1, caused abnormal vasoconstriction, elevated blood pressure which increased the risk of hypertension recurrence and an unsuccessful RDN procedure, and also was an early sign of the development of atherosclerosis [35].