Pulsatile hemodynamics and microcirculation: evidence for a close relationship in hypertensive patients

Endothelial dysfunction influences augmented aortic hemodynamic responses to metaboreflex activation in postmenopausal women

PURPOSE

Postmenopausal women experience augmented aortic hemodynamic responses to isometric handgrip (IHG) exercise and metaboreflex activation post-exercise muscle ischemia (PEMI). Relationships between endothelial function brachial artery flow-mediated dilation (FMD) and aortic stiffness carotid-femoral pulse wave velocity (cfPWV) with aortic pulsatile hemodynamics during IHG and PEMI have not been determined. The relationships between aortic hemodynamic responses to PEMI were evaluated.

METHODS

Aortic blood pressure (BP), wave reflection, and pressure of forward (Pf) and backward (Pb) waves were measured using arterial tonometry at rest, IHG at 30% maximal force, and PEMI in 30 (15/group) postmenopausal women with low (≤ 4.5%) and normal (≥ 5.5%) FMD. Hemodynamic responses were analyzed as the change (Δ) from rest to the last minute of IHG and PEMI.

RESULTS

Brachial and aortic systolic BP (SBP) responses to IHG were higher in the low vs normal FMD group (P < 0.05). Aortic SBP (Δ20 ± 8 vs Δ11 ± 7 mmHg), pulse pressure (PP) (Δ12 ± 8 vs Δ6 ± 4 mmHg), augmented pressure (AP) (Δ5 ± 3 vs Δ2 ± 2 mmHg), and Pb (Δ6 ± 4 vs Δ3 ± 2 mmHg) responses to PEMI were greater (P < 0.05) in women with low vs. normal FMD. FMD was negatively correlated with aortic SBP, PP, AP, and Pb (P < 0.05) responses to PEMI. cfPWV was not correlated with responses to PEMI.

CONCLUSION

Endothelial dysfunction relates to augmented aortic pulsatile load during metaboreflex activation, which may increase cardiovascular risk in postmenopausal women.

Temporary decrease in microvascular tissue saturation after transcatheter aortic valve implantation

BACKGROUND

Data on the effect of transcatheter aortic valve implantation (TAVI) on peripheral microcirculation are limited.

OBJECTIVE

The aim of this study is to evaluate peripheral microvascular tissue saturation (StO2) before and after TAVI in relation to central and peripheral hemodynamics, cardiac and renal function.

METHODS

In this single-center prospective study, patients with severe aortic stenosis (sAS) scheduled for TAVI or cardiac catheterization (control) were assessed before and up to five days after the procedure. Cardiac function including cardiac output (CO) was assessed by echocardiography. Brachial (bBP) and central blood pressure (cBP), ankle brachial index (ABI), and parameters of arterial stiffness, including augmentation pressure (AP) and augmentation index adjusted for heart rate (AIx@HR75) were measured to assess hemodynamic changes. StO2 was measured in all extremities using a near-infrared spectroscopy (NIRS) camera. Renal function was measured by creatinine levels.

RESULTS

26 patients underwent TAVI and 11 patients served as control. Cardiac output was significantly increased, whereas hemodynamic parameters and peripheral StO2 were significantly decreased after TAVI. At follow-up, StO2 returned to baseline values. Changes in StO2 were negatively related to creatinine levels.

CONCLUSION

Transcatheter aortic valve implantation causes a temporary decrease in microvascular tissue saturation that is associated with renal function.

Retinal microvascular alterations in patients with active rheumatoid arthritis without cardiovascular risk factors: the potential effects of T cell co-stimulation blockade

Background

The evaluation of microvascular alterations might provide clinically useful information for patients with an increased cardiovascular (CV) risk, such as those with rheumatoid arthritis (RA), being the small artery remodeling the earliest form of target organ damage in primary CV diseases, such as arterial hypertension. The evaluation of retinal arterioles is a non-invasive technique aimed to identify an early microvascular damage, represented by the increase of the wall-to-lumen ratio (WLR) index. Abatacept (ABA), a T-cell co-stimulator blocker, is used to treat RA. A CV protective action was hypothesized for its peculiar mechanism of action in the modulation of T-cells, potentially involved in the pathogenesis of CV comorbidity. The study aimed to non-invasively investigate morphological characteristics of retinal arterioles in a cohort of RA patients treated with ABA.

Materials and methods

Seventeen RA patients [median (25th-75thpercentile) age = 58 (48-64) years, baseline 28-joint Disease Activity Score DAS28-C-reactive protein (DAS28-CRP) = 4.4 (3.9-4.6), body mass index (BMI) = 24.2 (23.4-26) kg/m2, rheumatoid factor positive:52.9%, anti-citrullinated peptide autoantibodies positive:76.5%] without known CV risk factors (arterial hypertension, diabetes, hypercholesterolemia, previous CV events, smoking) were evaluated by the adaptive optics imaging system of retinal arterioles before and every 6 months of therapy with ABA (T0, T6 and T12). Office blood pressure evaluation, 24-h ambulatory blood pressure monitoring and tissue-doppler echocardiography were also performed.

Results

A progressive significant reduction of the WLR of retinal arterioles was observed [T0 = 0.28 (0.25-0.30), T6 = 0.27 (0.24-0.31), T12 = 0.23 (0.23-0.26); p T0 vs. T6 = 0.414; p T6 vs. T12 = 0.02; p T0 vs. T12 = 0.009], without significant variations in other parameters. The T0-T12 reduction of WLR was correlated with that of DAS28-CRP (r:0.789; p = 0.005). Moreover, a significant reduction of diastolic office blood pressure and a trend for reduction of daily pressure measured by ambulatory monitoring were observed.

Conclusion

In a cohort of RA patients without known CV risk factors, a reduction of retinal microvascular alterations was demonstrated after treatment for 12 months with ABA, in parallel with the reduction of disease activity. These results might suggest the possibility of microvascular abnormalities regression induced by the immune system modulation.

Arterial Stiffness: From Basic Primers to Integrative Physiology

The elastic properties of conductance arteries are one of the most important hemodynamic functions in the body, and data continue to emerge regarding the importance of their dysfunction in vascular aging and a range of cardiovascular diseases. Here, we provide new insight into the integrative physiology of arterial stiffening and its clinical consequence. We also comprehensively review progress made on pathways/molecules that appear today as important basic determinants of arterial stiffness, particularly those mediating the vascular smooth muscle cell (VSMC) contractility, plasticity and stiffness. We focus on membrane and nuclear mechanotransduction, clearance function of the vascular wall, phenotypic switching of VSMCs, immunoinflammatory stimuli and epigenetic mechanisms. Finally, we discuss the most important advances of the latest clinical studies that revisit the classical therapeutic concepts of arterial stiffness and lead to a patient-by-patient strategy according to cardiovascular risk exposure and underlying disease.

Microcirculation in Hypertension: A Therapeutic Target to Prevent Cardiovascular Disease?

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.

Association between morphologic features of intracranial distal arteries and brain atrophy indexes in cerebral small vessel disease: a voxel-based morphometry study

Background

Brain atrophy represents a final common pathway for pathological processes in patients with cerebral small vessel disease (CSVD) and is now recognized as a strong independent predictor of clinical status and progression. The mechanism underlying brain atrophy in patients with CSVD is not yet fully comprehended. This study aims to investigate the association of morphologic features of intracranial distal arteries (A2, M2, P2 and more distal) with different brain structures [gray matter volume (GMV), white matter volume (WMV), and cerebrospinal fluid volume (CSFV)]. Furthermore, we also examined whether a correlation existed between these cerebrovascular characteristics and GMV in different brain regions.

Method

A total of 39 participants were eventually enrolled. The morphologic features of intracranial distal arteries based on TOF-MRA were extracted and quantified using the intracranial artery feature extraction technique (iCafe). The brain 3D-T1 images were segmented into gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) using the "Segment" tool in CAT12 for the voxel-based morphometry (VBM) analysis. Univariable and multivariable linear regression models were used to investigate the relationship between these cerebrovascular features and different brain structures. Partial correlation analysis with a one-tailed method was used to evaluate the relationship between these cerebrovascular features and GMV in different brain regions.

Results

Our findings indicate that both distal artery length and density were positively correlated with GM fraction in CSVD patients, regardless of whether univariable or multivariable linear regression analyses were performed. In addition, distal artery length (β = -0.428, p = 0.007) and density (β = -0.337, p = 0.036) were also found to be negative associated with CSF fraction, although this relationship disappeared after adjusting for potential confounders. Additional adjustment for the effect of WMHs volume did not change these results. In subgroup anasysis, we found that participants in the highest distal artery length tertile had significantly higher GM fraction and lower CSF fraction level than participants in the lowest distal artery length tertile. In partial correlation analysis, we also found that these cerebrovascular characteristics associated with regional GMV, especially subcortical nuclear.

Conclusion

The morphologic features of intracranial distal arteries, including artery length, density and average tortuosity, measured from 3D-TOF MRA, are associated with generalized or focal atrophy indexes of CSVD.

Nonlinear relationship between pulse pressure and risk of cognitive impairment: A 4-year community-based cohort study in Xi'an, China

OBJECTIVES

It has been known that pulse pressure (PP) is a risk factor for cardiovascular disease and stroke, however, the relationship between PP and cognitive impairment is unclear.

METHODS

This was a community-based cohort study. Participates were followed-up for 4 years and new-onset cognitive impairment was diagnosed. Multivariable logistic regression and restricted cubic spline (RCS) were used to investigate the relationship between PP and cognitive impairment. Propensity score matching (PSM) and sensitivity analysis among ApoEε4 non-carriers were performed to confirm the results.

RESULTS

1462 participants were included at baseline and 1173 completed the follow-up. There were 42 (3.5%) new-onset cognitive impairment of whom 31 were diagnosed with MCI and 11 with dementia during the follow-up. Multivariable logistic regression analysis showed that PP was positively associated with cognitive impairment (OR = 2.853, 95% CI 1.079-7.548, p = 0.035), and RCS suggested a non-linear relationship (P_non-linear = 0.034). The risk of cognitive impairment merely changed when the PP was below about 46.7 mmHg and increased rapidly thereafter. After the covariates were well balanced using PSM (standardized mean differences <0.1 for all covariates), logistic regression analysis revealed the risk of cognitive impairment was still higher for those with high PP (OR = 3.369, 95% CI 1.202-9.441, p = 0.021). Sensitivity analysis showed consistent results with primary analysis.

CONCLUSION

PP is associated with cognitive impairment in a non-linear manner among middle-aged and elderly. The risk of cognitive impairment increases rapidly when PP exceeds about 46.7 mmHg, which may be informative for subsequent research of PP control ranges.

Association of Pressure Wave Reflections With Left Ventricular Mass: a Systematic Review and Meta-Analysis

BACKGROUND

Pressure wave reflections (PWRs) within the circulation are assessed at various arterial sites by various noninvasive methods. We aimed at reviewing the conflicting data regarding the hypothesis that higher PWRs are associated with higher left ventricular mass and tested whether this association stands for all available indices of PWRs, all (proximal or distal to the heart) sites of assessment, and is modified by sex, age and heart rate.

METHODS

Based on a predefined protocol applying the Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines, we identified eligible for meta-analysis data regarding: augmentation index, augmentation pressure, backward pressure (Pb), reflection index, and their association with left ventricular mass index (19 studies, total population n=8686).

RESULTS

We found statistically significant associations, independent from blood pressure level, for all indices of PWRs at all arterial sites (carotid augmentation index; odds ratio; standardized beta coefficient [β]: 0.14 [95% CI, 0.07% to 0.21%], per SD increase), radial augmentation index (β: 0.21; 0.11 to 0.31), central augmentation pressure (β: 0.15; 0.03 to 0.27), central Pb (β: 0.23; 0.05 to 0.42), and central reflection index (β: 0.14; 0.06 to 0.22), except for aortic augmentation index as estimated by generalized transfer functions. Meta-regression analysis showed that the association between carotid augmentation index and left ventricular mass was higher among populations with higher heart rate (P=0.036, beta: 0.017 [95% CI, 0.001 to 0.033]) and tended to be higher in middle-aged (P=0.07, beta: -0.001; -0.021 to 0.001).

CONCLUSIONS

A clinically meaningful association between PWRs and left ventricular mass, assessed at either central or peripheral arterial sites by most available methods was shown, suggesting that PWR reduction strategies might be useful. Based on the present evidence, such trials should target middle-aged populations with high normal heart rate.

State of the Art Review: Vascular Remodeling in Hypertension

Although the gold-standard method for the assessment of structural alteration in small resistance arteries is the evaluation of the MLR by micromyography in bioptic tissues, new, noninvasive techniques are presently under development, focusing mainly on the evaluation of WLR in retinal arterioles. These approaches represent a promising and interesting future perspective. Appropriate antihypertensive treatment is able to prevent the development of microvascular alterations or to induce their regression. Also, conductance arteries may be affected by a remodeling process in hypertension, and a cross-talk may exist between structural changes in the small and large arteries. In conclusion, the evaluation of microvascular structure is ready for clinical prime time, and it could, in the future, represent an evaluation to be performed in the majority of hypertensive patients, to better stratify cardiovascular risk and better evaluate the effects of antihypertensive therapy. However, for this purpose, we need a clear demonstration of the prognostic relevance of noninvasive measures of microvascular structure, in basal conditions and during treatment. Vascular remodeling may be frequently observed in hypertension, as well as in obesity and diabetes mellitus. An increased media to lumen ratio (MLR) or wall to lumen ratio (WLR) in microvessels is the hallmark of hypertension, and may impair organ flow reserve, being relevant in the maintenance and, probably, also in the progressive worsening of hypertensive disease, as well as in the development of hypertension-mediated organ damage/cardiovascular events. The molecular mechanisms underlying the development of vascular remodeling are only partly understood.

Pulse Pressure Is Associated with Rapid Cognitive Decline over 4 Years: A Population-Based Cohort Study

Aiming to investigate the relationship between pulse pressure (PP) and cognitive decline, cognitively normal subjects from a community-based longitudinal cohort were followed-up for 4 years. The Mini-Mental State Examination (MMSE) was used to evaluate global cognitive function, and a ≥2-point decrease in the MMSE score from baseline was defined as cognitive decline. Restricted cubic spline, multivariable linear regression and logistic regression were used to investigate the relationship between PP and cognitive decline. A total of 1173 participants completed the follow-up, and 205 (17.5%) met the criteria for cognitive decline. Restricted cubic splines showed no nonlinear relationship between PP and ΔMMSE (P_overall = 0.037, P_non-linear = 0.289) or cognitive decline (P_overall = 0.003, P_non-linear = 0.845). Multivariable linear regression analysis showed that PP was positively related to ΔMMSE (b = 0.021, p = 0.020). Multivariable logistic regression analysis showed that PP was positively associated with cognitive decline (OR = 1.020, p = 0.023). A stratified analysis found an association between PP and cognitive decline in participants who were aged ≤65 years, male, and APOEε4 noncarriers and who had school education ≤6 years or hypertension. A sensitivity analysis after propensity-score matching did not alter our findings. These findings highlight that elevated PP is associated with rapid cognitive decline, particularly in males, middle-aged, low-educated, hypertensive individuals and APOEε4 noncarriers.

Unattended versus Attended Blood Pressure Measurement: Relationship with Retinal Microcirculation

Though the relationship between both “attended” and “unattended” BP and several forms of target organ damage have been evaluated, data on retinal arteriolar alterations are lacking. The aim of our study was to evaluate the relationship between “attended” or “unattended” BP values and retinal arteriolar changes in consecutive individuals undergoing a clinical evaluation and assessment of retinal fundus at an ESH Excellence Centre. An oscillometric device programmed to perform 3 BP measurements, at 1 min intervals and after 5 min of rest was used on all individuals to measure BP with the patient alone in the room (“unattended”) or in the presence of the physician (“attended”) in the same day in a random order. The retinal arteriole’s wall thickness (WT) was measured automatically by a localization algorithm as the difference between external (ED) and internal diameter (ID) by adaptive optics (RTX-1, Imagine Eyes, Orsay, Francia). Media-to-lumen ratio (WLR) of the retinal arterioles and cross-sectional area (WCSA) of the vascular wall were calculated. Results: One-hundred-forty-two patients were examined (mean age 57 ± 12 yrs, 48% female, mean BMI 26 ± 4). Among them, 60% had hypertension (84% treated) and 11% had type 2 diabetes mellitus. Unattended systolic BP (SBP) was lower as compared to attended SBP (129 ± 14.8. vs. 122.1 ± 13.6 mmHg, p < 0.0001). WLR was similarly correlated with unattended and attended SBP (r = 0.281, p < 0.0001 and r = 0.382, p < 0.0001) and with unattended and attended diastolic BP (r = 0.34, p < 0.001 and r = 0.29, p < 0.0001). The differences between correlations were not statistically significant (Steiger’s Z test). Conclusion: The measurement of “unattended” or “attended” BP provides different values, and unattended BP is lower as compared to attended BP. In this study a similar correlation was observed between attended and unattended BP values and structural changes of retinal arterioles.

Microcirculation and Macrocirculation in Hypertension: A Dangerous Cross-Link?

Microcirculation and macrocirculation are tightly interconnected into a dangerous cross-link in hypertension. Small artery damage includes functional (vasoconstriction, impaired vasodilatation) and structural abnormalities (mostly inward eutrophic remodeling). These abnormalities are major determinants of the increase in total peripheral resistance and mean blood pressure (BP) in primary hypertension, which in the long term induces large artery stiffening. In turn, large artery stiffening increases central systolic and pulse pressures, which are further augmented by wave reflection in response to the structural alterations in small resistance arteries. Finally, transmission of high BP and flow pulsatility to small resistance arteries further induces functional and structural abnormalities, thus leading to increased total peripheral resistance and mean BP, thus perpetuating the vicious circle. Hyperpulsatility, in addition to higher mean BP, exaggerates cardiac, brain, and kidney damages and leads to cardiovascular, cerebral, and renal complications. The dangerous cross-link between micro and macrocirculation can be reversed into a virtuous one by ACE (angiotensin-converting enzyme) inhibitors, sartans, and calcium channel blockers. These three pharmacological classes are more potent than β-blockers and diuretics for reducing arterial stiffness and small artery remodeling. The same ranking was observed for their effectiveness at reducing left ventricular hypertrophy, preserving glomerular filtration rate, and preventing dementia, suggesting that they can act beyond brachial BP reduction, by breaking the micro/macrocirculation vicious circle.

Peripheral microcirculatory abnormalities are associated with cardiovascular risk in systemic sclerosis: a nailfold video capillaroscopy study

INTRODUCTION

Microvascular dysfunction is the key element in the pathogenesis of systemic sclerosis (SSc), whereas the contribution of large and medium size vessel abnormalities is yet to be established. The aim of the present study is to assess the association between micro- and macrovascular function by utilizing a broad spectrum of assessments of vascular performance.

METHODS

We included consecutive, consenting SSc patients who underwent nailfold video capillaroscopy (NVC) for microcirculation evaluation. Peripheral and central systolic and diastolic blood pressure, carotid intima-media thickness (cIMT), aortic augmentation index (AIx) corrected for a heart rate of 75 beats per minute (AIx-75), and carotid-femoral pulse wave velocity (PWV) were also performed to assess macrovascular function. Cardiovascular risk disease (CVD) algorithms were also calculated and included in the analysis.

RESULTS

A total of 81 patients (6 males) were studied with mean age 55.44 ± 13.40 years. Reduced capillary density was inversely correlated with arterial stiffness (Alx-75) and augmentation pressure (r =  - 0.262, p = 0.018, and r =  - 0.249, p = 0.025 respectively). Alx was significantly lower in the early compared to late pattern (28.24 ± 11.75 vs 35.63 ± 10.47, p = 0.036). A significant trend was found among NVC patterns with Alx-75 values being higher with the progression of microangiopathy towards the "late" group (26.36 ± 10.90 vs 30.81 ± 11.59 vs 35.21 ± 7.90, p = 0.027 for trend). Similarly, Framingham risk score and Atherosclerotic Cardiovascular Disease score were progressively higher across the worsening NVC patterns (4.10 ± 4.13 vs 2.99 ± 2.72 vs 6.36 ± 5.65, p = 0.023, and 6.99 ± 7.18 vs 5.63 ± 4.41 vs 12.09 ± 9.90, p = 0.019, respectively, for trends). Finally, QRISK3 (10-year cardiovascular disease risk) and ASCVD (Atherosclerotic Cardiovascular Disease) scores were inversely correlated with the number of capillaries (r =  - 0.231, p = 0.048, and r =  - 0.260, p = 0.038 respectively).

CONCLUSION

These data suggest that CVD risk scores and macrovascular parameters are strongly correlated with microvasculopathy in patients with SSc. Key Points • Microangiopathy is the hallmark of SSc, but the relationship between subclinical atherosclerosis and small vessel disease remains unknown. • Arterial stiffening and CVD risk scores are positively associated with the degree of progression of peripheral microvasculopathy assessed with NVC. • The results of the study suggest an association between NVC abnormalities and higher CVD risk in SSc patients.

MRI-Based Investigation of Association Between Cerebrovascular Structural Alteration and White Matter Hyperintensity Induced by High Blood Pressure

BACKGROUND

High blood pressure (BP) is a common risk factor for cerebral small vessel disease including white matter hyperintensity (WMH). Whether increased BP exacerbates WMH by impacting cerebral vascular morphologies remains poorly studied.

PURPOSE

To determine the relationships among high BP, cerebrovascular morphologies, and WMH in elderly individuals.

STUDY TYPE

Cohort.

SUBJECTS

Eight hundred sixty-three participants (54.2% female) from the Taizhou Imaging Study without clinical evidence of neurologic disorders were included in the analyses.

FIELD STRENGTH/SEQUENCE

3.0 T; time-of-flight magnetic resonance angiography (TOF MRA); T2 fluid-attenuated inversion recovery (FLAIR); T1 magnetization-prepared rapid gradient-echo; gradient echo T2*-weighted; diffusion tensor imaging; pulsed arterial spin labeling.

ASSESSMENT

Cerebrovascular morphologic measurements were quantified based on the TOF MRA images, including vessel density, radius, tortuosity, and branch number. WMH lesion volumes (WMHV) and WMH lesion counts (WMHC) were calculated automatically based on the T2 FLAIR images.

STATISTICAL TESTS

Multivariable linear regression analysis and path analysis with a linear single-mediator model were employed. A P value <0.05 was considered statistically significant.

RESULTS

Higher BP, especially diastolic BP, was significantly correlated with lower cerebrovascular density (β = -104) and lower branch numbers (β = -0.02). Although decreased tortuosity (β = -1.25) and increased radius (β = 93.8) were correlated with BP, no significant relationship of tortuosity (β = -4.6 × 10^-4 , P = 0.58) or radius (β = 0.03, P = 0.08) with BP in small vessels was found. The proportion of small vessels decreased as BP increased (SBP: β = -6.6 × 10^-4 ; DBP: β = -9.0 × 10^-4 ). Similarly, increased WMHV and WMHC were associated with decreased vessel density (volumes: β = -24, counts: β = -127), decreased tortuosity (volumes: β = -0.08, counts: β = -0.53), and increased radius (volumes: β = 12.6, counts: β = 86.6). Path analyses suggested an association between high BP and WMHs that were mediated by cerebrovascular morphologic changes.

DATA CONCLUSION

Structural alterations of cerebral vessels induced by high BP are correlated with WMH. This result suggested that elevated BP might be one of the pathophysiological mechanisms involving in the co-occurrence of cerebrovascular alteration and small vessel disease.

LEVEL OF EVIDENCE

1 Technical Efficacy Stage: 1.

Arterial Stiffness and Cardiovascular Risk in Hypertension

Arterial stiffness, a leading marker of risk in hypertension, can be measured at material or structural levels, with the latter combining effects of the geometry and composition of the wall, including intramural organization. Numerous studies have shown that structural stiffness predicts outcomes in models that adjust for conventional risk factors. Elastic arteries, nearer to the heart, are most sensitive to effects of blood pressure and age, major determinants of stiffness. Stiffness is usually considered as an index of vascular aging, wherein individuals excessively affected by risk factor exposure represent early vascular aging, whereas those resistant to risk factors represent supernormal vascular aging. Stiffness affects the function of the brain and kidneys by increasing pulsatile loads within their microvascular beds, and the heart by increasing left ventricular systolic load; excessive pressure pulsatility also decreases diastolic pressure, necessary for coronary perfusion. Stiffness promotes inward remodeling of small arteries, which increases resistance, blood pressure, and in turn, central artery stiffness, thus creating an insidious feedback loop. Chronic antihypertensive treatments can reduce stiffness beyond passive reductions due to decreased blood pressure. Preventive drugs, such as lipid-lowering drugs and antidiabetic drugs, have additional effects on stiffness, independent of pressure. Newer anti-inflammatory drugs also have blood pressure independent effects. Reduction of stiffness is expected to confer benefit beyond the lowering of pressure, although this hypothesis is not yet proven. We summarize different steps for making arterial stiffness measurement a keystone in hypertension management and cardiovascular prevention as a whole.

An Algorithm for the Noninvasive and Personalized Measurement of Microvascular Blood Viscosity Using Physiological Parameters

Blood viscosity is one of the important parameters to characterize hemorheological properties of the human body. Its real-time and dynamic measurement has important physiological significance for studying the development and prevention of chronic diseases. This study researched noninvasive and personalized measurement of microvascular blood viscosity. In the microcirculation capillary network blood flow model, combined with pulse wave parameters, multiple regression analysis was used to fit the simulated radius of personalized physiological blood vessels to calculate the microvascular blood viscosity. The fitted value related to the simulated radius of the physiological blood vessel had a high correlation with the corresponding theoretically derived value (correlation coefficient: 0.904, P ≤ 0.001). The calculated value of the microvascular blood viscosity had a certain correlation with the clinical whole blood viscosity at a low shear rate (correlation coefficient: 0.443, P < 0.05). This algorithm could provide effective means for noninvasive and long-term individual monitoring and family health care.

Effect of direct renin inhibition on vascular function after long-term treatment with aliskiren in hypertensive and diabetic patients

OBJECTIVE

We tested the hypothesis that chronic treatment with the direct renin inhibitor aliskiren improves vascular function in resistance and conduit arteries of type two diabetic and hypertensive patients.

METHOD

Sixteen patients with mild essential hypertension and with a previous diagnosis of noninsulin-dependent diabetes mellitus were included in the study. Patients were then randomized to aliskiren (150 mg once daily, n = 9), or ramipril (5 mg once daily, n = 7). Each patient underwent a biopsy of the subcutaneous tissue and small arteries were dissected and mounted on a pressurized micromyograph to evaluate endothelium dependent vasorelaxation in response to acetylcholine ± N omega-nitro-L-arginine methyl ester hydrochloride in vessels precontracted with norepinephrine. Endothelial function has been quantified also in large conduit arteries by flow-mediated dilation.

RESULTS

A similar office blood pressure-lowering effect was observed with the two drugs, although changes in DBP were not statistically significant in the ramipril group. Aliskiren significantly improved endothelium-dependent relaxation in subcutaneous resistance arteries, as well as increased flow-mediated dilation in conduit arteries, whereas the effects induced by ramipril did not reach statistical significance. Only aliskiren significantly increased the expression of p1177-endothelial nitric oxide synthase in the endothelium. Both aliskiren and ramipril had a negligible effect on markers of oxidative stress.

CONCLUSION

Aliskiren restored endothelial function and induced a more prompt peripheral vasodilation in hypertensive and diabetic patients possibly through the increased production of nitric oxide via the enhanced expression and function of the active phosphorylated form of endothelial nitric oxide synthase.

A high normal ankle-brachial index is associated with biopsy-proven severe renal small artery intimal thickening and impaired renal function in chronic kidney disease

A significant relationship has been established between central hemodynamics and renal microvascular damage. We hypothesized that the increase in the ankle-brachial index (ABI) with age is due to increased arterial stiffness and wave reflection and is thus associated with the pathogenesis of the renal small artery in patients with chronic kidney disease (CKD). We recruited 122 patients with CKD (stages 1-5) who underwent renal biopsy and ABI measurements between 2010 and 2013. Renal small artery intimal thickening (SA-IT) severity was assessed by semiquantitative grading. The median age was 47 years, with a range of 15-86 years (47% women). The median estimated glomerular filtration rate (eGFR) was 62 mL/min/1.73 m². Compared with patients with the lowest 1-3 SA-IT index quartile, those with the highest quartile of the SA-IT index were older in age had higher mean arterial pressure, ABI, brachial-ankle pulse wave velocity, and lower eGFR. ABI was positively associated with SA-IT severity and inversely associated with eGFR. Multivariate logistic regression analyses showed that ABI was significantly associated with the highest quartile of the SA-IT index (odds ratio per SD increase in ABI, 1.83; 95% confidence interval, 1.08-3.26) and low eGFR (<60 mL/min/1.73 m²) (odds ratio per SD increase in ABI, 1.74; 95% confidence interval, 1.03-3.03). In conclusion, a high normal ABI was associated with severe renal small artery intimal thickening and low eGFR in patients with CKD.

Aortic stiffness is not only associated with structural but also functional parameters of retinal microcirculation

OBJECTIVE

The aim of the study was to test the hypothesis that alterations in large arteries are associated with microvascular remodelling and decreased retinal capillary blood flow.

METHODS

The study group comprised of 88 patients with essential hypertension and 32 healthy controls. Retinal microcirculation was evaluated by scanning laser Doppler flowmetry. Macrovascular changes were assessed on the basis of arterial stiffness measurement (carotid-femoral pulse wave velocity), its hemodynamic consequences (central pulse pressure, augmentation pressure, augmentation index) and intima media thickness of common carotid artery.

RESULTS

Pulse wave velocity was inversely correlated to mean retinal capillary blood flow in hypertensive patients (R = -0.32, p < 0.01). This relationship remained significant in multivariate regression analysis after adjustment for age, sex, central systolic blood pressure (BP) and body mass index (β = -31.27, p < 0.001). Lumen diameter (LD) of retinal arterioles was significantly smaller in hypertensive then normotensive subjects (79.4 vs. 83.8, p = 0.03). Central and brachial systolic, diastolic and mean BPs were significantly correlated with LD and outer diameter of retinal arterioles. The relationship between LD and central BPs remained significant in multivariate analysis (β = -0.15, p = 0.03 for cSBP; β = -0.22, p = 0.04 for cDBP; β = -0.21, p = 0.03 for cMBP). Moreover, in a subgroup with cardiac damage central and brachial pulse pressure were positively associated with retinal wall thickness, wall cross sectional area, and wall to lumen ratio.

CONCLUSION

In conclusion, the study provides a strong evidence that microcirculation is coupled with macrocirculation not only in terms of structural but also functional parameters.

Arterial stiffness correlates with progressive nailfold capillary microscopic changes in systemic sclerosis: results from a cross-sectional study

BACKGROUND

While microangiopathy is well-documented in systemic sclerosis (SSc), a potential link between SSc and macrovascular disease is highly debated and remains to be established. The aim of the present study is to investigate the association between micro- and macrovascular involvement in the setting of SSc.

METHODS

Consecutive, consenting SSc patients were assessed by nailfold video-capillaroscopy (NVC) to evaluate the microcirculation. The number of capillaries per mm² and the capillaroscopic skin ulcer risk index (CSURI) were measured, and findings were also classified into three scleroderma patterns (i.e., early, active, and late). Carotid intima-media thickness (IMT), aortic augmentation index corrected for a heart rate of 75 beats per minute (AIx-75), carotid-femoral pulse wave velocity (PWV), and central systolic and diastolic blood pressure were also determined to assess macrovascular function.

RESULTS

A total of 37 patients were studied. A significant correlation was observed between AIx and the average number of capillaries per mm² (r = - 0.34, p = 0.047) and between AIx and CSURI (r = 0.35, p = 0.044). Patients with the "early" scleroderma pattern had lower AIx values compared with "active" (20.5 ± 11.4 vs 34.1 ± 11.5%, p = 0.02) and "late" (20.5 ± 11.4 vs 33.4 ± 8.8%, p = 0.05) patterns. No other significant correlations were found between macrovascular biomarkers (PWV, carotid IMT, systolic and diastolic central blood pressure) and the capillaroscopic measurements.

CONCLUSIONS

These data suggest that arterial stiffness (as assessed by AIx-75) correlates with microvascular damage in patients with SSc.

Peripheral arterial stiffness is correlated with intrarenal arteriolosclerosis according to biopsies from patients with kidney disease

AIM

To investigate the possible associations between intrarenal arteriolosclerosis as determine by renal biopsy and endothelial function as well as arterial stiffness measured by peripheral arterial tonometry (EndoPAT).

METHODS

This was a cross-sectional study. Patients who underwent both renal biopsy and EndoPAT were recruited, and intrarenal arteriolosclerosis was graded according to the pathological slice. Endothelial function and arterial stiffness were both measured by EndoPAT and were expressed by the reactive hyperemia index (RHI) and augmentation index (AIx), respectively. AIx@75, representing the AIx standardized to a heart rate of 75 bpm was also determined.

RESULTS

In total, 113 patients were assessed, the mean age was 51 ± 13, and 68.1% were men. The natural logarithm RHI (LnRHI), AIx and AIx@75 were significantly different among different grades of intrarenal arteriolosclerosis (P = .030, P < .001, P < .001, respectively). In the multivariable adjusted model, for every SD increase in the AIx and AIx@75, the odds of having more severe arteriolosclerosis were 2.506 times (95% confidence interval [CI] 1.464-4.288, P = .001] and 3.191 times (95% CI 1.780-5.719, P < .001) higher, respectively, and the association between the LnRHI and intrarenal arteriolosclerosis was nullified (P = .059). The positive values of the AIx and AIx@75 for the diagnosis of severe intrarenal arteriolosclerosis were 0.80 (95% CI 0.73-0.88, P < .001) and 0.78 (95% CI 0.70-0.87, P < .001), respectively.

CONCLUSION

Subjects with more severe intrarenal arteriolosclerosis have greater peripheral vascular stiffness; AIx and AIx@75 reflected peripheral vascular stiffness could be used to identify patients with severe intrarenal arteriolosclerosis.

Arterial stiffness and peripheral vascular resistance in offspring of hypertensive parents: influence of sex and other confounders

AIM

Established essential hypertension is associated with increased arterial stiffness and peripheral resistance, but the extent of vascular changes in persons genetically predisposed for essential hypertension is uncertain.

METHODS

Participants from the Danish Hypertension Prevention Project (DHyPP) (both parents hypertensive) (n = 95, 41 ± 1 years, 53% men) were compared with available spouses (n = 45, 41 ± 1 years) using measurements of ambulatory blood pressure (BP), left ventricular mass index (LVMI), pulse wave velocity, central BP and augmentation index (AIx) in addition to forearm resting and minimal resistance [forearm resting vascular resistance (Rrest) and forearm minimal vascular resistance (Rmin)].

RESULTS

DHyPP patients with participating spouses had higher 24-h mean BP (94 ± 1 vs. 88 ± 1 mmHg, P < 0.01), LVMI (94 ± 3 vs. 80 ± 2 g/m, P < 0.01), central SBP (121 ± 2 vs. 111 ± 2 mmHg, P < 0.01) and AIx (16.0 ± 1.2 vs. 10.5 ± 1.7%, P < 0.01), but similar carotid-femoral pulse wave velocity (7.5 ± 0.2 vs. 7.1 ± 0.2 m/s), Rrest (53 ± 3 vs. 51 ± 3 mmHg/ml/min/100 ml) and log Rmin (0.58 ± 0.02 vs. 0.55 ± 0.02 mmHg/ml/min/100 ml) when compared with spouses. Using multiple linear regression analysis (adjusting for sex, age, BMI, creatinine clearance and 24-h BP, heart rate and sodium excretion) AIx and LVMI remained elevated in DHyPP patients [4.2% (0.7; 7.7), P = 0.02 and 6.3 g/m (0.7; 11.9), P = 0.03]. For the entire DHyPP cohort AIx, Rrest and Rmin were higher in women than men (P < 0.01), and the same was true for AIx and Rmin among spouses (P < 0.05). Furthermore, AIx was linearly associated with Rrest and Rmin.

CONCLUSION

Young to middle-aged individuals genetically predisposed for essential hypertension display increased AIx and LVMI, although vascular stiffness and peripheral resistance are still normal.

Vascular Aging and Disease of the Small Vessels

Cardiovascular events are the consequence of vascular damage at both the macro and microcirculatory level. The relationship between large stiffening artery and microvascular disease may be bidirectional, since wave reflection from microvascular sites could increase systolic blood pressure and pulse pressure, while transmission of increased arterial pulsatility to microvessels could represent a mechanism of damage. Hypertension and aging share similar mechanisms of vascular dysfunction. In fact, vascular remodelling, endothelial dysfunction and vascular stiffness are common features in hypertension and aging. Structural and functional changes in small arteries occur during normal and accelerated aging, possibly triggered by hypertension. A cross-talk may be present between large and small artery changes, interacting with pressure wave transmission and reflection, exaggerating cardiac, brain and kidney damage, and finally leading to cardiovascular and renal complications.

What Do We Know about Diet and Markers of Cardiovascular Health in Children: A Review

Chronic diseases such as cancer, diabetes, and cardiovascular diseases (CVD) are the main health concerns in the 21st century, with CVD as the number one cause of mortality worldwide. Although CVD hard endpoints such as stroke or heart attack do not usually occur in children, evidence shows that the manifestation of CVD risk factors begins in childhood, preceding clinical complications of CVD in adulthood. Dietary intake is a modifiable risk factor that has been shown to make a substantial contribution to the risk of CVD in adulthood. However, less is known about the association between dietary intake and markers of cardiovascular health in children. This review summarises the current evidence on the relationship between dietary intake and markers of cardiovascular health including traditional CVD risk factors, physical fitness, and indices of arterial stiffness and wave reflection in children. Original research published in English, between January 2008 and December 2018 fulfilling the objective of this review were screened and included. Findings show that adaptation of a healthy lifestyle early in life can be beneficial for reducing the risk of CVD later in life. Furthermore, keeping arterial stiffness low from a young age could be a potential CVD prevention strategy. However, limited studies are available on diet-arterial stiffness relationship in children, and future research is required to better understand this association to aid the development and implementation of evidence-based strategies for preventing CVD-related complications later in life.

Aggressive systolic blood pressure control in older subjects: benefits and risks

Systolic hypertension, especially isolated systolic hypertension (ISH) is very common in older subjects aged ≥ 65 years and is a major risk factor for cardiovascular disease (CVD), strokes, heart failure (HF) and chronic kidney disease (CKD). It is also, directly and linearly related with these complications irrespective of sex, or ethnicity, but it is worse with the advancement of age. Effective control of systolic blood pressure (SBP), is associated with significant reduction in the incidence of these complications. Currently, there is a debate about the optimal SBP control in view of the Systolic Blood Pressure Intervention Trial (SPRINT) showing beneficial cardiovascular (CV) effects of intensive SBP of < 120 mmHg in older patients. Also, the recently released blood pressure (BP) guidelines by the American College of Cardiology, the American Heart Association and the American Society of Hypertension (ACC/AHA/ASH) recommend a SBP reduction of < 130 mmHg. These SBP treatment recommendations are in contrast with the current (JNC VIII) committee of BP treatment guidelines, which recommend a SBP reduction < 150 mmHg for the same age of patients. All these different recommendations have created a debate regarding the optimal treatment targets for the systolic hypertension of the elderly patients. To gain more information a focused Medline search was conducted from 2010 to 2017 using the terms, systolic blood pressure, aggressive control, older subjects, treatment guidelines, and 37 pertinent papers were retrieved. The findings from these studies suggest a SBP reduction of < 140 mm Hg for persons aged ≥ 60 years, with an attempt for SBP reduction to ≤130 mm Hg in healthier subjects and hose with CVD, DM, and CKD. Care should be taken not to further reduce the SBP in older subjects if their DBP is ≤60 mmHg for the fear of J-curve effect.

Higher arterial stiffness is associated with lower cognitive performance in patients with hypertension

Cognitive impairment and elevated arterial stiffness have been described in patients with arterial hypertension, but their association has not been well studied. We evaluated the correlation of arterial stiffness and different cognitive domains in patients with hypertension compared with those with normotension. We evaluated 211 patients (69 with normotension and 142 with hypertension). Patients were age matched and distributed according to their blood pressure: normotension, hypertension stage 1, and hypertension stage 2. Cognitive function was assessed using the Mini-Mental State Examination, Montreal Cognitive Assessment, and a battery of neuropsychological evaluations that assessed six main cognitive domains. Pulse wave velocity was measured using a Complior device, and carotid properties were assessed by radiofrequency ultrasound. Central arterial pressure and augmentation index were obtained using applanation tonometry. The hypertension stage 2 group had higher arterial stiffness and worse performance either by Mini-Mental State Examination (26.8±2.1 vs 27.3±2.1 vs 28.0±2.0, P=.003) or the Montreal Cognitive Assessment test (23.4±3.5 vs 24.9±2.9 vs 25.6±3.0, P<.001). On multivariable regression analysis, augmentation index, intima-media thickness, and pulse wave velocity were the variables mainly associated with lower cognitive performance at different cognitive domains. Cognitive impairment in different domains was associated with higher arterial stiffness.

Hemodynamic Consequences of Changes in Microvascular Structure

In hypertension, an increased media-to-lumen ratio of small resistance arteries might play an important role in the increase of vascular resistance, and may also be an adaptive response to the increased hemodynamic load. The presence of morphological alteration in the microvasculature may be associated to an impaired tissue perfusion and/or to the development of target organ damage. Structural alterations in the microcirculation might represent a predictor of the onset of cardio-cerebrovascular events and hypertension complications. A cross-talk between the small and large artery may exaggerate arterial damage, following a vicious circle. Therefore, in the present review, possible hemodynamic consequences of the presence of microvascular structural alterations will be considered, in terms of their time of onset, role in the development and/or maintenance of high blood pressure values, and interrelationships with structural/mechanical alterations of large conductance arteries.

Comparison of lercanidipine plus hydrochlorothiazide vs. lercanidipine plus enalapril on micro and macrocirculation in patients with mild essential hypertension

Dihydropyridine calcium channel blockers may possess antioxidant properties, and might improve micro and macrovascular structure and function. Combination treatment with an ACE inhibitor may have additional advantages, compared with a thiazide diuretic. The aim of the present study is to investigate the effects of a short-term treatment with lercanidipine, and to compare two combination treatments: lercanidipine + enalapril vs. lercanidipine + hydrochlorothiazide on structural alterations in retinal arterioles, on skin capillary density and on large artery distensibility. Thirty essential hypertension patients are included in the study, and treated for 4 weeks with lercanidipine 20 mg per day orally. Then, they were treated for 6 months with lercanidipine + enalapril (n = 15) or lercanidipine + hydrochlorothiazide (n = 15) combinations. Investigations were performed on basal condition, after appropriate wash out of previous treatments, after 4 weeks of lercanidipine monotherapy treatment, and at the end of the combination treatment. Non-invasive measurements of wall-to-lumen ratio (WLR) and other morphological parameters of retinal arterioles were performed using either scanning laser Doppler flowmetry or adaptive optics. Capillary density was evaluated by capillaroscopy, while pulse wave velocity was measured, and central blood pressures were assessed by pressure waveform analysis. A significant improvement of WLR and other indices of retinal artery structure is observed with both technical approaches after treatment with lercanidipine alone, with a further improvement after treatment with lercanidipine + enalapril, while after treatment with lercanidipine + hydrochlorothiazide, the improvement is partially blunted. Central systolic and diastolic blood pressures are similarly reduced by both therapeutic strategies. Capillary density is increased only after treatment with lercanidipine + enalapril. In conclusion, lercanidipine both in monotherapy and in combination with enalapril but not with hydrochlorothiazide is able to improve microvascular structure; on the other hand, a decrease in central blood pressure is observed with both therapeutic combinations.

Vascular Smooth Muscle Cells and Arterial Stiffening: Relevance in Development, Aging, and Disease

The cushioning function of large arteries encompasses distension during systole and recoil during diastole which transforms pulsatile flow into a steady flow in the microcirculation. Arterial stiffness, the inverse of distensibility, has been implicated in various etiologies of chronic common and monogenic cardiovascular diseases and is a major cause of morbidity and mortality globally. The first components that contribute to arterial stiffening are extracellular matrix (ECM) proteins that support the mechanical load, while the second important components are vascular smooth muscle cells (VSMCs), which not only regulate actomyosin interactions for contraction but mediate also mechanotransduction in cell-ECM homeostasis. Eventually, VSMC plasticity and signaling in both conductance and resistance arteries are highly relevant to the physiology of normal and early vascular aging. This review summarizes current concepts of central pressure and tensile pulsatile circumferential stress as key mechanical determinants of arterial wall remodeling, cell-ECM interactions depending mainly on the architecture of cytoskeletal proteins and focal adhesion, the large/small arteries cross-talk that gives rise to target organ damage, and inflammatory pathways leading to calcification or atherosclerosis. We further speculate on the contribution of cellular stiffness along the arterial tree to vascular wall stiffness. In addition, this review provides the latest advances in the identification of gene variants affecting arterial stiffening. Now that important hemodynamic and molecular mechanisms of arterial stiffness have been elucidated, and the complex interplay between ECM, cells, and sensors identified, further research should study their potential to halt or to reverse the development of arterial stiffness.

Microvascular structure as a prognostically relevant endpoint

Remodelling of subcutaneous small resistance arteries, as indicated by an increased media-to-lumen ratio, is frequently present in hypertensive, obese, or diabetic patients. The increased media-to-lumen ratio may impair organ flow reserve. This may be important in the maintenance and, probably, also in the progressive worsening of hypertensive disease. The presence of structural alterations represents a prognostically relevant factor, in terms of development of target organ damage or cardiovascular events, thus allowing us a prediction of complications in hypertension. In fact, media-to-lumen ratio of small arteries at baseline, and possibly their changes during treatment may have a strong prognostic significance. However, new, non-invasive techniques are needed before suggesting extensive application of the evaluation of remodelling of small arteries for the cardiovascular risk stratification in hypertensive patients. Some new techniques for the evaluation of microvascular morphology in the retina, currently under clinical investigation, seem to represent a promising and interesting future perspective. The evaluation of microvascular structure is progressively moving from bench to bedside, and it could represent, in the near future, an evaluation to be performed in all hypertensive patients, to obtain a better stratification of cardiovascular risk, and, possibly, it might be considered as an intermediate endpoint in the evaluation of the effects of antihypertensive therapy, provided that a demonstration of a prognostic value of non-invasive measures of microvascular structure is made available.

Brachial-ankle PWV for predicting clinical outcomes in patients with acute stroke

BACKGROUND

Although brachial-ankle pulse wave velocity (baPWV) is well-known for predicting the cardiovascular mortality and morbidity, its anticipated value is not demonstrated well concerning acute stroke.

METHODS

Total 1557 patients with acute stroke who performed baPWV were enrolled. We evaluated the prognostic value of baPWV predicting all-cause death and vascular death in patients with acute stroke Results: Highest quartile of baPWV was ≥23.64 m/s. All-caused deaths (including vascular death; 71) were 109 patients during follow-up periods (median 905 days). Multivariate Cox regression analysis revealed that patients with the highest quartile of baPWV had higher risk for vascular death when they are compared with patients with all other three quartiles of baPWV (Hazard ratio with 95% confidence interval [CI] 1.879 [1.022-3.456], p = .042 for vascular death).

CONCLUSION

High baPWV was a strong prognostic value of vascular death in patients with acute stroke.

Central Hemodynamics and Arterial Stiffness in Systemic Sclerosis

Although microvascular disease is a hallmark of systemic sclerosis (SSc), a higher prevalence of macrovascular disease and a poorer related prognosis have been reported in SSc than in the general population. The simultaneous assessment of prognostically relevant functional properties of larger and smaller arteries, and their effects on central hemodynamics, has never been performed in SSc using the state-of-the-art techniques. Thirty-four women with SSc (aged 61±15 years, disease duration 17±12 years, and blood pressure 123/70±18/11 mm Hg) and 34 healthy women individually matched by age and mean arterial pressure underwent the determination of carotid-femoral (aortic) and carotid-radial (upper limb) pulse wave velocity (a direct measure of arterial stiffness), aortic augmentation (a measure of the contribution of reflected wave to central pulse pressure), and aortobrachial pulse pressure amplification (brachial/aortic pulse pressure) through applanation tonometry (SphygmoCor). Patients and controls did not differ by carotid-femoral or carotid-radial pulse wave velocity. Aortic augmentation index corrected for a heart rate of 75 bpm (AIx@75) was higher in women with SSc (30.9±16% versus 22.2±12%; P =0.012). Patients also had a lower aortobrachial amplification of pulse pressure (1.22±0.18 versus 1.33±0.25; P =0.041). SSc was an independent predictor of AIx@75 (direct) and pulse pressure amplification (inverse). Among patients, age, mean arterial pressure, and C-reactive protein independently predicted carotid-femoral pulse wave velocity. Age and mean arterial pressure were the only predictors of AIx@75. Women with SSc have increased aortic augmentation and decreased pulse pressure amplification (both measures of the contribution of reflected wave to central waveform) but no changes in aortic or upper limb arterial stiffness. Microvascular involvement occurs earlier than large artery stiffening in SSc.

Central wave reflection is associated with peripheral arterial resistance in addition to arterial stiffness in subjects without antihypertensive medication

Background

Augmentation index, a marker of central wave reflection, is influenced by age, sex, height, blood pressure, heart rate, and arterial stiffness. However, the detailed haemodynamic determinants of augmentation index, and their relations, remain uncertain. We examined the association of augmentation index with vascular resistance and other haemodynamic and non-haemodynamic factors.

Methods

Background information, laboratory values, and haemodynamics of 488 subjects (239 men, 249 women) without antihypertensive medication were obtained. Indices of central wave reflection, systemic vascular resistance, cardiac function, and pulse wave velocity were measured using continuous radial pulse wave analysis and whole-body impedance cardiography.

Results

In a regression model including only haemodynamic variables, augmentation index in males and female subjects, respectively, was associated with systemic vascular resistance (β = 0.425, β = 0.336), pulse wave velocity (β = 0.409, β = 0.400) (P < 0.001 for all), stroke volume (β = 0.256, β = 0.278) (P = 0.001 for both) and heart rate (β = −0.150, β = −0.156) (P = 0.049 and P = 0.036). When age, height, weight, smoking habits, and laboratory values were included in the regression model, the most significant explanatory variables for augmentation index in males and females, respectively, were age (β = 0.577, β = 0.557) and systemic vascular resistance (β = 0.437, β = 0.295) (P < 0.001 for all). In the final regression model, pulse wave velocity was not a significant explanatory variable for augmentation index, probably due to the high correlation of this variable with age (Spearman’s correlation ≥0.617).

Conclusion

Augmentation index is strongly associated with systemic vascular resistance in addition to arterial stiffness.

Trial registration

ClinicalTrials.gov, NCT01742702.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-016-0303-6) contains supplementary material, which is available to authorized users.

Reversing gene expression in cardiovascular target organs following chronic depression of the paraventricular nucleus of hypothalamus and rostral ventrolateral medulla in spontaneous hypertensive rats

BACKGROUND

Chronic overexpression of an inwardly rectifying potassium channel (hKir2.1) in the paraventricular nucleus of the hypothalamus (PVN) and in the rostral ventrolateral medulla (RVLM) to suppress neuronal excitability, resulted in a long term decrease of blood pressure and sympathetic output in spontaneously hypertensive rats (SHR).

OBJECTIVE

Evaluate gene expression in end-organs of SHR after a chronic overexpression of hKir2.1 channels in either the PVN or RVLM.

METHODS

mRNA levels of 16 genes known to be involved with blood pressure regulation were evaluated using RT-PCR in tissues from the heart, common carotid artery and kidney of SHR submitted to chronic depression of PVN and RVLM excitability using a lentiviral vector (LVhKir2.1).

RESULTS

In SHR hearts in which either the PVN or RVLM were injected with LVhKir2.1, there was a downregulation of angiotensin II receptor 1b (AT1), ATPase, Ca(2+)-transporter, troponin T2 and tropomyosin2 (only in RVLM) relative to the sham group. In the kidney of SHR with LVhKir2.1 injections in PVN and RVLM, angiotensinogen, angiotensin II receptor2 (AT2) and endothelin1 were all upregulated compared to sham. In the carotid artery, endothelin2, endothelin receptor A and B were up-regulated following LVhKir2.1 in to either the PVN or RVLM relative to sham.

CONCLUSION

Chronic overexpression of hKir2.1 channels in PVN and RVLM, promoted a BP decrease with up-regulation of angiotensinogen and AT2 genes expression in the kidney and down-regulation of AT1 in the heart of SHR. Thus, we demonstrate the potential efficacy of central manipulation to protect against end-organ damage in essential hypertension.

Relationship Between Carotid Atherosclerosis and Pulse Pressure with Renal Hemodynamics in Hypertensive Patients

BACKGROUND

Structural atherosclerotic damage, arterial stiffness, pulse pressure (PP), and renal hemodynamics may interact and influence each other. Renal resistance index (RRI) appears as a good indicator of systemic vascular changes. The aim of our study was to assess the independent relationships of carotid intima-media thickness (cIMT), aortic pulse wave velocity (aPWV), and peripheral PP with RRI in hypertensives with various degrees of renal function.

METHODS

We enrolled 463 hypertensive patients (30-70 years) with normal renal function (group 0; n = 280) and with chronic kidney disease (groups I-V; n = 183). All subjects underwent ultrasonographic examination of intrarenal and carotid vasculature, as well as a 24-h ambulatory blood pressure monitoring.

RESULTS

A statistically significant difference in RRI, cIMT, aPWV, and clinic PP was observed in the different 6 groups (all P < 0.001), even after adjustment for age. RRI correlated with cIMT (r = 0.460, P < 0.001), aPWV (r = 0.386, P < 0.001), clinic PP (r = 0.279, P < 0.001), and 24-h PP (r = 0.229, P < 0.001) in the entire study population. These correlations were similar in subjects with and without renal dysfunction. In the overall study population, the association between RRI, cIMT, and clinic PP remained statistically significant even after adjustment for various confounding factors, whereas the relationship between RRI and aPWV was lost in multivariate analysis.

CONCLUSIONS

cIMT and clinic PP rather than directly aPWV are associated with intrarenal hemodynamics. Our results confirm that in hypertensives RRI not only detects derangement of intrarenal circulation but may also be considered as a sensor of systemic vascular changes, independently of level of renal function.

Association of Central Versus Brachial Blood Pressure With Target-Organ Damage: Systematic Review and Meta-Analysis

Accumulating evidence suggests that central blood pressure (BP) may reflect the hemodynamic stress on target organs more accurately than brachial BP. A systematic review assessing the relationship of central versus brachial BP with preclinical target-organ damage was performed. Meta-analysis of cross-sectional data showed that central compared with brachial systolic BP was more closely associated with (1) left ventricular mass index (12 studies, n=6431; weighted age [SD], 49.9 [13.1] years; 51% hypertensives): pooled correlation coefficients r=0.30; 95% confidence interval (CI), 0.23-0.37 versus r=0.26; 95% CI, 0.19-0.33, respectively; P<0.01 for difference; (2) carotid intima-media thickness (7 studies, n=6136; weighted age, 55.6 [13.2] years; 48% hypertensives): r=0.27; 95% CI, 0.19-0.34 versus r=0.23; 95% CI, 0.16-0.30, respectively; P<0.01 for difference; (3) pulse-wave velocity (14 studies, n=3699; weighted age, 53.9 [13.3] years; 53% hypertensives): r=0.42; 95% CI, 0.37-0.47 versus r=0.39; 95% CI, 0.33-0.45, respectively; P<0.01 for difference. Four studies assessing urine albumin excretion (n=3718; weighted age, 56.4 [5] years; 69% hypertensives) reported similar correlations (P=not significant) with central (r=0.22; 95% CI, 0.14-0.29) and brachial systolic BP (r=0.22; 95% CI, 0.12-0.32). Similar findings were observed for central compared with brachial pulse pressure in terms of relationship with target-organ damage. Metaregression analyses did not reveal any significant effect of age. In conclusion, central compared with brachial BP seems to be more strongly associated with most of the investigated indices of preclinical organ damage.

Association Between Arterial Stiffness and Skin Microvascular Function: The SUVIMAX2 Study and The Maastricht Study

BACKGROUND

It has been hypothesized that arterial stiffness leads to generalized microvascular dysfunction and that individuals with type 2 diabetes mellitus (T2DM) are particularly prone to the detrimental effects of arterial stiffness. However, evidence for an association between stiffness and markers of generalized microvascular dysfunction is lacking. We therefore investigated the association between arterial stiffness and skin microvascular function in individuals without and with T2DM.

METHODS

Cross-sectional data were used of The Supplementation en Vitamines et Mineraux Antioxydants 2 (SUVIMAX2) Study (n = 284/62.2 years/48.6% women/0% T2DM (by design)) and The Maastricht Study (n = 737/59.7 years/45.2% women/28.8% T2DM (by design)). Arterial stiffness was determined by carotid-femoral pulse wave velocity (cfPWV). Skin capillaroscopy was used to determine capillary density at baseline, and during reactive hyperemia and venous congestion. Laser Doppler flowmetry was used to assess acetylcholine- and local heating-induced vasoreactivity, and skin flowmotion.

RESULTS

In The SUVIMAX2 Study, cfPWV (per +1 SD) was not associated with baseline capillary density (regression coefficient: -0.48 (95% confidence interval: 2.37; 1.41)) or capillary recruitment during venous congestion (0.54% (-0.74; 1.81%)). In addition, cfPWV was not associated with acetylcholine (-0.02% (-0.14; 0.10%)) or local heating-induced vasoreactivity (0.03% (-0.07; 0.12%)). In The Maastricht Study, in individuals without T2DM, cfPWV was not associated with baseline capillary density (-1.20 (-3.17; 0.77)), and capillary recruitment during reactive hyperemia (1.22% (-0.41; 2.84%)) or venous congestion (1.50% (-0.25; 3.25%)). In addition, cfPWV was not associated with flowmotion (-0.01 (-0.07; 0.06)). Results were adjusted for age and sex. Additional adjustments for confounders did not materially change these results. Results were qualitatively similar in individuals with T2DM.

CONCLUSIONS

Arterial stiffness is not associated with skin microvascular function, irrespective of the presence of T2DM.