In experimental hypertension, the increase in peripheral resistance occurs at the microvascular level. It was clearly demonstrated that wall thickness is increased in relation to internal lumen and that this alteration contributes to peripheral resistance. The increased media/lumen ratio may impair organ flow reserve [25]. This may be important in the maintenance and, probably, also in the progressive worsening of hypertensive disease. The evaluation of microvascular structure is not an easy task. The techniques with highest accuracy, such as wire or pressure micromyography, have the limitation of requiring biological samples, obtained by surgical approaches (e.g., gluteal biopsies). However, the presence of structural alterations evaluated by such approaches represents a prognostically relevant factor, in terms of development of target organ damage or cardiovascular events, thus allowing the prediction of hypertension complications [26, 27].

New, noninvasive techniques are needed before suggesting extensive application of the evaluation of microvascular morphology for the cardiovascular risk stratification in hypertensive patients. Some new techniques for evaluation of microvascular morphology in the retina, presently under clinical investigation, seem to represent a promising and interesting future perspective.

Presently, we may safely state that the evaluation of microvascular structure is progressively moving from bench to bedside [28], and it could represent, in the immediate future, an evaluation to be performed in all hypertensive patients, in order to obtain a better stratification of cardiovascular risk, and perhaps, it might be considered as an intermediate end point in the evaluation of the effects of antihypertensive therapy [29, 30].