Capillary Rarefaction as an Index for the Microvascular Assessment of Hypertensive Patients

Abstract

Arterial hypertension represents a leading cause of cardiovascular mortality and morbidity worldwide through its detrimental effects on target organs. Therefore, the early identification and appropriate management of high-risk patients emerges as extremely important. Given that the microvasculature is subject to a series of morphological and functional changes under the continuous effect of high blood pressure, research over the last years has gradually moved toward the identification of specific microcirculatory alterations that may serve as early prognostic markers of cardiovascular risk. Dermal capillaries represent an "open window" for the in vivo study of human microcirculation that has been long used mainly for the study of rheumatic diseases. However, capillaroscopy has been relatively understudied and only recently applied in the field of hypertension. Capillaroscopy represents a forthcoming promising estimate of the microvascular status in hypertensive patients, with capillary rarefaction representing the most typical finding. The present review aims at summarizing available evidence and the main findings, as well as the premises and promises, of capillary rarefaction as a tool for evaluating patients with hypertension.

Neuronal nitric oxide synthase in hypertension – an update

“…Sustained pressure-overload in conjunction with systematic inflammation, oxidative stress and endothelial dysfunction in hypertension stimulates a series of adverse outcomes of the heart, including ventricular hypertrophy [6], collagen deposition or fibrosis [7], dilatation [8] and coronary artery stiffening or rarefaction [9, 10]. The fundamental mechanisms those cause these changes involve altered ion channels and transporters in the plasmalemmal membrane of cardiac myocytes; abnormal calcium handling in cardiac myocytes; metabolic derangement; sarcomere disorganization and changes in the wide spectrum of intracellular signaling pathways [6, 11–17] .…”

Improvement in Retinal Capillary Rarefaction After Valsartan Treatment in Hypertensive Patients

“…In hypertensive patients, capillary density has previously been shown to inversely correlate with office BP levels in capillaries of the skin and cerebral capillaries . One previous study found an inverse relationship between 24‐hour systolic BP and capillary recruitment in skin capillaries of normotensive individuals .…”

“…Whether capillary density improves in parallel in the cerebrovascular bed is speculative but the rationale is solid according to the similarity of changes in the retinal and cerebrovascular beds in hypertension. 22 In hypertensive patients, capillary density has previously been shown to inversely correlate with office BP levels in capillaries of the skin 8,26,27 and cerebral capillaries. 21 One previous study found an inverse relationship between 24-hour systolic BP and capillary recruitment in skin capillaries of normotensive individuals.…”

In vivo optical imaging of the viable epidermis around the nailfold capillaries for the assessment of heart failure severity in humans

“…Also a key use of NVC in the group of systemic sclerosis spectrum disorders is to distinguish the primary Raynaud's phenomenon from disease . Moreover, a successful application of NVC to evaluate and classify microvascular involvement has been reported for such pathologies as diabetes and systemic or pulmonary arterial hypertension when severe capillary alterations such as heterogeneously enlarged loops, capillary loss and neoangiogenesis can be observed . Although NVC has been demonstrated to be capable of assessing dynamic characteristics of blood flow, it has certain shortcomings and is predominantly limited to the analysis of static images and morphology of the capillary network .…”