Dual renin-angiotensin systemblockade and vascular remodeling. Is this a real advantage for vascular protection?

Essential hypertension is characterized by increased peripheral vascular resistance to blood flow particularly in younger individuals. Resistance arteries undergo vascular remodeling (reduced vascular lumen with increased media thickness) that may be functional, mechanical, and/or structural [1,2][1,2]. Small decreases in the lumen diameter significantly increase resistance to blood flow. Increased media-to-lumen ratio (M/L) is the most reproducible parameter of vascular remodeling of resistance arteries [1,3][1,3]. Interestingly, an increased M/L ratio of subcutaneous small resistance arteries is a potent predictor of cardiovascular events in patients with increased blood pressure values [4–6][4–6][4–6] and different cardiovascular risk [4,5][4,5]. In hypertensive patients, it is thought that increased M/L ratio could be the earliest alteration that occurs in the vasculature [7] and may precede endothelial dysfunction [7,8][7,8]. The extent of structural alterations in subcutaneous small resistance arteries is particularly pronounced in hypertensive patients with type 2 diabetes mellitus [9] or obesity [10–12][10–12][10–12]. Thus, the association of several cardiovascular risk factors may have a synergistic, deleterious effect on the microcirculation. Furthermore, the remodeled resistance arteries are the sites of origin of most of the wave reflections that travel backward toward the heart, contributing to the stiffness of large arteries and the increased central SBP.