Roles of endothelial and smooth muscle cell dysfunction and vasa vasorum in vasomotor disorders in ischemia with no obstructive coronary artery disease.

Recently, the importance has emerged of ischemia with no obstructive coronary artery disease (INOCA), for which endothelial and vascular smooth muscle cell (VSMC) dysfunctions and alterations in coronary vasa vasorum are involved. Regarding endothelial vasodilator functions, both endothelium-derived nitric oxide and endothelium-derived hyperpolarizing factor play important roles in modulating vascular tone, especially in the microcirculation. Recent studies have suggested systemic endothelial dysfunction in INOCA. Regarding VSMC dysfunction, Rho-kinase has been identified as a key molecular mechanism of VSMC hyperconstriction in INOCA. Finally, recent advances of coronary imaging have demonstrated the important role of altered adventitial vasa vasorum functions in INOCA.