Low-grade inflammatory processes and related oxidative stress may have a key role in the pathogenesis of hypertension and hypertension-mediated organ damage. Innate immune cells, such as neutrophils, ...dendritic cells, monocytes/macrophages, as well as unconventional T lymphocytes like γδ T cells contribute to hypertension and may trigger vascular inflammation. Adaptive immunity has been demonstrated to participate in elevation of blood pressure and in vascular and kidney injury. In particular, effector T lymphocytes (Th1, Th2, and Th17) may play a relevant role in promoting hypertension and microvascular remodeling, whereas T-regulatory lymphocytes may have a protective role. Effector cytokines produced by these immune cells lead to increased oxidative stress, endothelial dysfunction and contribute to target organ damage in hypertension. A possible role of immune cell subpopulations in the development and regression of microvascular remodeling has also been proposed in humans with hypertension. The present review summarizes the key immune mechanisms that may participate in the pathophysiology of hypertension-mediated inflammation and vascular remodeling; advances in this field may provide the basis for novel therapeutics for hypertension.
Background:
Vascular Ehlers–Danlos syndrome (vEDS) is an inherited connective tissue disorder characterized by arterial fragility. Celiprolol has been suggested to significantly reduce rates of ...vascular events in this setting, though real-world evidence is limited. The aim of this study was to report our experience with celiprolol therapy in vEDS management.
Methods:
Patients with a genetically confirmed diagnosis of vEDS who were referred for outpatient consultation at the Brescia University Hospital between January 2011 and July 2023 were included. At each visit, patients’ medical history, results of vascular imaging, and office blood pressure measurements were recorded. Celiprolol therapy was progressively titrated to the maximum tolerated dose of up to 400 mg daily, according to the patients’ tolerance.
Results:
Overall, 26 patients were included. Female sex was prevalent (62%). Mean (SD) age was 37 (16) years. Follow-up duration was 72 (41) months. At the last follow-up visit, all patients were on celiprolol therapy, 80% of whom were taking the maximum recommended dose. The yearly risk of symptomatic vascular events was 8.8%, the majority of which occurred after reaching the maximum recommended dose of celiprolol. No significant predictor of symptomatic vascular events was identified among patients’ clinical characteristics.
Conclusion:
In our cohort, rates of celiprolol use were high and the drug was well tolerated overall. Nonetheless, the risk of symptomatic vascular events remained nonnegligible. Future studies should identify reliable predictors of major adverse events and explore additional therapeutic strategies that could further lower the risk of life-threatening events in this population.
Some reports have suggested that inflammation in perivascular adipose tissue (PVAT) may be implicated in vascular dysfunction by causing the disappearance of an anticontractile effect. The aim of ...this study was to investigate the effects of chronic melatonin treatment on the functional responses of the small mesenteric arteries and on the expression of markers of inflammation/oxidative stress in the aortas of senescence-accelerated prone mice (SAMP8), a model of age-related vascular dysfunction. We investigated seven SAMP8 and seven control senescence-accelerated resistant mice (SAMR1) treated for 10 months with melatonin, as well as equal numbers of age-matched untreated SAMP8 and SAMR1. The mesenteric small resistance arteries were dissected and mounted on a wire myograph, and the concentration-response to norepinephrine was evaluated in vessels with intact PVAT and after the removal of the PVAT. The expression of markers of oxidative stress, inflammation and aging in the aortas was evaluated by immunostaining. In addition, the adiponectin content and the expression of adiponectin receptor 1 were evaluated in the visceral adipose tissue. In untreated SAMP8 mice, we observed an overexpression of oxidative stress and inflammatory markers in the vasculature compared with the controls. No anticontractile effect of the PVAT was observed in untreated SAMP8 mice. Long-term treatment of SAMP8 mice with melatonin increased the expression of some markers of vasoprotection, decreased oxidative stress and inflammation and restored the anticontractile effect of the PVAT. Decreased expression of adiponectin and adiponectin receptor 1 was also observed in visceral fat of untreated SAMP8, whereas a significant increase was observed after melatonin treatment.
Hypertension is associated with important alterations in the morphology of small arteries and arterioles. Vascular-specific manifestations are changes in the structure and function of vascular smooth ...muscle cells, extracellular matrix, perivascular tissues, and endothelial cells. Arteriole and capillary remodeling and capillary rarefaction have been observed in hypertensive animals and human beings which contribute to increased vascular resistance. An impairment of different angiogenetic factors, such as VEGF (vascular endothelial growth factor), VEGFR-2 (vascular endothelial growth factor receptor-2), TIMP-1 (tissue inhibitor matrix metalloproteinases-1), and TSP-1 (thrombospondin-1), seems to be responsible for the reduction of the microvascular network. Exercise training has been shown to improve vascular structure and function in hypertension not only in the large arteries but also in the peripheral circulation. Exercise training may regress microvascular remodeling and normalize capillary density, leading to capillary growth possibly by increasing proangiogenic stimuli such as VEGF. Exercise enhances endothelium-dependent vascular relaxation through nitric oxide release increase and oxidative stress reduction. Other mechanisms include improved balance between prostacyclin and thromboxane levels, lower circulating levels of endothelin-1, attenuation of infiltration of immune cells into perivascular adipose tissue, and increase of local adiponectin secretion. In addition, exercise training favorably modulates the expression of several microRNAs leading to a positive modification in muscle fiber composition. Identifying the bioactive molecules and biological mechanisms that mediate exercise benefits through pathways that differ from those used by antihypertensive drugs may help to improve our knowledge of hypertension pathophysiology and facilitate the development of new therapeutic strategies.
The presence of structural alterations in the microcirculation may be considered an important mechanism of organ damage; however, it is not currently known whether structural alterations of small ...arteries may predict fatal and nonfatal cardiovascular events.
One hundred twenty-eight patients were included in the present study. There were 59 patients with essential hypertension, 17 with pheochromocytoma, 20 with primary aldosteronism, 12 with renovascular hypertension, and 20 normotensive patients with non-insulin-dependent diabetes mellitus. All subjects were submitted to a biopsy of subcutaneous fat. Small resistance arteries were dissected and mounted on an isometric myograph, and the tunica media-to-internal lumen ratio (M/L) was measured. The subjects were reevaluated after an average follow-up time of 5.4 years. Thirty-seven subjects had a documented fatal or nonfatal cardiovascular event (5.32 events/100 patients per year). In the subcutaneous small arteries of subjects with cardiovascular events, a smaller internal diameter and a clearly greater M/L was observed. Our subjects were subdivided according to the presence of an M/L greater or smaller than the mean and median values observed in the whole population (0.098) or mean value +2 SD of our normal subjects (0.11). Life-table analyses showed a significant difference in event-free survival between the subgroups. Cox's proportional hazard model, considering all known cardiovascular risk factors, indicated that only pulse pressure (P=0.009) and M/L (P<0.0001) were significantly associated with the occurrence of cardiovascular events.
Our results strongly indicate a relevant prognostic role of structural alterations in small resistance arteries of a high-risk population.
Hypertension is a major cardiovascular risk factor that is responsible for a heavy burden of morbidity and mortality worldwide. A critical aspect of cardiovascular risk estimation in hypertensive ...patients depends on the assessment of hypertension-mediated organ damage (HMOD), namely the generalized structural and functional changes in major organs induced by persistently elevated blood pressure values. The vasculature of the eye shares several common structural, functional, and embryological features with that of the heart, brain, and kidney. Since retinal microcirculation offers the unique advantage of being directly accessible to non-invasive and relatively simple investigation tools, there has been considerable interest in the development and modernization of techniques that allow the assessment of the retinal vessels' structural and functional features in health and disease. With the advent of artificial intelligence and the application of sophisticated physics technologies to human sciences, consistent steps forward have been made in the study of the ocular fundus as a privileged site for diagnostic and prognostic assessment of diverse disease conditions. In this narrative review, we will recapitulate the main ocular imaging techniques that are currently relevant from a clinical and/or research standpoint, with reference to their pathophysiological basis and their possible diagnostic and prognostic relevance. A possible non pharmacological approach to prevent the onset and progression of retinopathy in the presence of hypertension and related cardiovascular risk factors and diseases will also be discussed.
It has been previously demonstrated that T lymphocytes may be involved in the development of hypertension and microvascular remodeling, and that circulating T effector lymphocytes may be increased in ...hypertension. In particular, Th1 and Th 17 lymphocytes may contribute to the progression of hypertension and microvascular damage while T-regulatory (Treg) lymphocytes seem to be protective in this regard. However, no data is available about patients with severe obesity, in which pronounced microvascular alterations were observed.
We have investigated 32 severely obese patients undergoing bariatric surgery, as well as 24 normotensive lean subjects and 12 hypertensive lean subjects undergoing an elective surgical intervention. A peripheral blood sample was obtained before surgery for assessment of CD4+ T lymphocyte subpopulations. Lymphocyte phenotype was evaluated by flow cytometry in order to assess T-effector and Treg lymphocytes.
A marked reduction of several Treg subpopulations was observed in obese patients compared with controls, together with an increased in CD4+ effector memory T-effector cells.
In severely obese patients, Treg lymphocytes are clearly reduced and CD4+ effector memory cells are increased. It may be hypothesized that they might contribute to the development of marked microvascular alterations previously observed in these patients.
Arterial hypertension is a common condition worldwide and an important risk factor for cardio- and cerebrovascular events, renal diseases, as well as microvascular eye diseases. Established ...hypertension leads to the chronic vasoconstriction of small arteries as well as to a decreased lumen diameter and the thickening of the arterial media or wall with a consequent increased media-to-lumen ratio (MLR) or wall-to-lumen ratio (WLR). This process, defined as vascular remodeling, was firstly demonstrated in small resistance arteries isolated from subcutaneous biopsies and measured by micromyography, and this is still considered the gold-standard method for the assessment of structural alterations in small resistance arteries; however, microvascular remodeling seems to represent a generalized phenomenon. An increased MLR may impair the organ flow reserve, playing a crucial role in the maintenance and, probably, also in the progressive worsening of hypertensive disease, as well as in the development of hypertension-mediated organ damage and related cardiovascular events, thus possessing a relevant prognostic relevance. New non-invasive techniques, such as scanning laser Doppler flowmetry or adaptive optics, are presently under development, focusing mainly on the evaluation of WLR in retinal arterioles; recently, also retinal microvascular WLR was demonstrated to have a prognostic impact in terms of cardio- and cerebrovascular events. A rarefaction of the capillary network has also been reported in hypertension, which may contribute to flow reduction in and impairment of oxygen delivery to different tissues. These microvascular alterations seem to represent an early step in hypertension-mediated organ damage since they might contribute to microvascular angina, stroke, and renal dysfunction. In addition, they can be markers useful in monitoring the beneficial effects of antihypertensive treatment. Additionally, conductance arteries may be affected by a remodeling process in hypertension, and an interrelationship is present in the structural changes in small and large conductance arteries. The review addresses the possible relations between structural microvascular alterations and hypertension-mediated organ damage, and their potential improvement with antihypertensive treatment.
Introduction
The aim of this study was to prospectively investigate whether the structure of cerebral small-resistance arteries is related to cerebral perfusion parameters as measured with dynamic ...susceptibility-weighted contrast magnetic resonance imaging (DSC-MRI) in a selected cohort of hypertensive and normotensive patients.
Methods
Ten hypertensive and 10 normotensive patients were included in the study. All patients underwent neurosurgical intervention for an intracranial tumor and were investigated with DSC-MRI at 1.5 T. Cerebral small-resistance arteries were dissected from a small portion of morphologically normal cerebral tissue and mounted on an isometric myograph for the measurement of the media-to-lumen (M/L) ratio. A quantitative assessment of cerebral blood flow (CBF) and volume (CBV) was performed with a region-of-interest approach. Correlation coefficients were calculated for normally distributed variables. The institutional review board approved the study, and informed consent was obtained from all patients.
Results
Compared with normotensive subjects, hypertensive patients had significantly lower regional CBF (mL/100 g/min) in the cortical grey matter (55.63 ± 1.90 vs 58.37 ± 2.19,
p
< 0.05), basal ganglia (53.34 ± 4.39 vs 58.22. ± 4.33,
p
< 0.05), thalami (50.65 ± 3.23 vs 57.56 ± 4.45,
p
< 0.01), subcortical white matter (19.32 ± 2.54 vs 22.24 ± 1.9,
p
< 0.05), greater M/L ratio (0.099 ± 0.013 vs 0.085 ± 0.012,
p
< 0.05), and lower microvessel density (1.66 ± 0.67 vs 2.52 ± 1.28,
p
< 0.05). A statistically significant negative correlation was observed between M/L ratio of cerebral arteries and CBF in the cortical grey matter (
r
= −0.516,
p
< 0.05), basal ganglia (
r
= −0.521,
p
< 0.05), thalami (
r
= −0.527
p
< 0.05), and subcortical white matter (
r
= −0.612,
p
< 0.01).
Conclusion
Our results indicate that microvascular structure might play a role in controlling CBF, with possible clinical consequences.
Structural alterations of subcutaneous small resistance arteries, as indicated by an increased media-to-lumen ratio, are frequently present in hypertensive and/or diabetic patients, and may represent ...the earliest alteration observed. Furthermore, media-to-lumen ratio of small arteries evaluated by micromyography has a strong prognostic significance; however, its extensive evaluation is limited by the invasivity of the assessment, since a biopsy of subcutaneous fat is needed. Noninvasive measurement of wall-to-lumen of retinal arterioles using scanning laser Doppler flowmetry (SLDF) has recently been introduced. However, this new technique has not yet been compared to micromyographic measurement, generally considered the gold standard approach.
We investigated 40 individuals and patients, 24 of them were hypertensive patients and 16 normotensive individuals. All patients underwent a biopsy of subcutaneous fat during an elective surgical intervention. Subcutaneous small resistance arteries were dissected and mounted on a wire myograph, and media-to-lumen ratio was measured. In addition, an evaluation of wall-to-lumen ratio of retinal arterioles by SLDF was performed (Heidelberg Retina Flowmeter, Heidelberg Engineering). A close correlation was observed between media-to-lumen ratio of subcutaneous small arteries and wall-to-lumen ratio of retinal arterioles (r = 0.76, P < 0.001; P < 0.001, r(2) = 0.57).
A noninvasive and easily repeatable procedure (intraobserver and interobserver variation coefficient <13%) such as an evaluation of the arterioles in the fundus oculi by SLDF may provide similar information regarding microvascular morphology compared with an invasive, accurate and prognostically relevant micromyographic measurement of media-to-lumen ratio of subcutaneous small arteries.
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