Current assessment of pulse wave velocity: comprehensive review of validation studies

The missing link between inflammation and arterial stiffness among different metabolic phenotypes

OBJECTIVES

Although metabolically healthy obesity (MHO) has begun to be seen as a being benign phenomenon, this conclusion is still not completely certain. Obesity is also associated with low-grade systemic inflammation and endothelial dysfunction. Thus, we aimed to assess Pulse Wave Velocity (PWV) as a marker of arterial stiffness and CV risk among individuals with MHO, metabolically unhealthy obesity (MUO), and metabolically healthy normal-weight (MHN).

METHODS

150 participants (n = 50 MHO, n = 50 MUO, n = 50 MHN) who had been admitted to our outpatient clinics were enrolled in this cross-sectional study. Demographic, anthropometric, clinical, and laboratory data, including hs-CRP and PWV, were recorded for all subjects.

RESULTS

hs-CRP and PWV were higher in MUO and MHO than MHN individuals (P < .05). hs-CRP showed a strong positive correlation with PWV (r = 0.85, P < .001). After adjusting for other risk factors, multivariate linear regression analysis showed that the PWV was independently associated with BMI (β = 0.08, P = .03), WC (β = 0.04, P = .04) and hs-CRP (β = 6.08, P < .001).

CONCLUSIONS

PWV, which is an important non-invasive marker of cardiovascular risk, is higher in MHO than in MHN as in MUO individuals. Moreover, PWV was positively correlated with the serum hs-CRP level as a conventional marker for systemic inflammation. Thus, MHO can be seen as a cardiometabolic risk marker.

Risk Assessment and Clinical Management of Children and Adolescents with Heterozygous Familial Hypercholesterolaemia. A Position Paper of the Associations of Preventive Pediatrics of Serbia, Mighty Medic and International Lipid Expert Panel

Heterozygous familial hypercholesterolaemia (FH) is among the most common genetic metabolic lipid disorders characterised by elevated low-density lipoprotein cholesterol (LDL-C) levels from birth and a significantly higher risk of developing premature atherosclerotic cardiovascular disease. The majority of the current pediatric guidelines for clinical management of children and adolescents with FH does not consider the impact of genetic variations as well as characteristics of vascular phenotype as assessed by recently developed non-invasive imaging techniques. We propose a combined integrated approach of cardiovascular (CV) risk assessment and clinical management of children with FH incorporating current risk assessment profile (LDL-C levels, traditional CV risk factors and familial history) with genetic and non-invasive vascular phenotyping. Based on the existing data on vascular phenotype status, this panel recommends that all children with FH and cIMT ≥0.5 mm should receive lipid lowering therapy irrespective of the presence of CV risk factors, family history and/or LDL-C levels Those children with FH and cIMT ≥0.4 mm should be carefully monitored to initiate lipid lowering management in the most suitable time. Likewise, all genetically confirmed children with FH and LDL-C levels ≥4.1 mmol/L (160 mg/dL), should be treated with lifestyle changes and LLT irrespective of the cIMT, presence of additional RF or family history of CHD.

The mitochondria-targeted antioxidant MitoQ attenuated PM2.5-induced vascular fibrosis via regulating mitophagy

Short-term PM2.5 exposure is related to vascular remodeling and stiffness. Mitochondria-targeted antioxidant MitoQ is reported to improve the occurrence and development of mitochondrial redox-related diseases. At present, there is limited data on whether MitoQ can alleviate the vascular damage caused by PM2.5. Therefore, the current study was aimed to evaluate the protective role of MitoQ on aortic fibrosis induced by PM2.5 exposure. Vascular Doppler ultrasound manifested PM2.5 damaged both vascular function and structure in C57BL/6J mice. Histopathological analysis found that PM2.5 induced aortic fibrosis and disordered elastic fibers, accompanied by collagen I/III deposition and synthetic phenotype remodeling of vascular smooth muscle cells; while these alterations were partially alleviated following MitoQ treatment. We further demonstrated that mitochondrial dysfunction, including mitochondrial reactive oxygen species (ROS) overproduction and activated superoxide dismutase 2 (SOD2) expression, decreased mitochondrial membrane potential (MMP), oxygen consumption rate (OCR), ATP and increased intracellular Ca2+, as well as mitochondrial fragmentation caused by increased Drp1 expression and decreased Mfn2 expression, occurred in PM2.5-exposed aorta or human aortic vascular smooth muscle cells (HAVSMCs), which were reversed by MitoQ. Moreover, the enhanced expressions of LC3II/I, p62, PINK1 and Parkin regulated mitophagy in PM2.5-exposed aorta and HAVSMCs were weakened by MitoQ. Transfection with PINK1 siRNA in PM2.5-exposed HAVSMCs further improved the effects of MitoQ on HAVSMCs synthetic phenotype remodeling, mitochondrial fragmentation and mitophagy. In summary, our data demonstrated that MitoQ treatment had a protective role in aortic fibrosis after PM2.5 exposure through mitochondrial quality control, which regulated by mitochondrial ROS/PINK1/Parkin-mediated mitophagy. Our study provides a possible targeted therapy for PM2.5-induced arterial stiffness.

Effectiveness of indoor air purification intervention in improving cardiovascular health: A systematic review and meta-analysis of randomized controlled trials

Indoor air purifiers are increasingly marketed for their health benefits, but their cardiovascular effects remain unclear. We systematically reviewed and meta-analysed randomized controlled trials (RCTs) on the cardiovascular effects of indoor air purification interventions in humans of all ages. We searched Embase, Medline, PubMed, and Web of Science from inception to 22 August 2020. Fourteen cross-over RCTs (18 publications) were included. Systolic blood pressure (SBP) was significantly reduced after intervention (-2.28 (95% CI: -3.92, -0.64) mmHg). There were tendencies of reductions in diastolic blood pressure (-0.35 [-1.52, 0.83] mmHg), pulse pressure (PP) (-0.86 [-2.07, 0.34] mmHg), C-reactive protein (-0.23 [-0.63, 0.18] mg/L), and improvement in reactive hyperaemia index (RHI) (0.10 [-0.04, 0.24]) after indoor air purification, although the effects were not statistically significant. However, when restricting the analyses to RCTs using physical-type purifiers only, significant improvements in PP (-1.56 [-2.98, -0.15] mmHg) and RHI (0.13 [0.01, 0.25]) were observed. This study found potential evidence on the short-term cardiovascular benefits of using indoor air purifiers, especially for SBP, PP and RHI. However, under the Grading of Recommendations Assessment, Development and Evaluation framework, the overall certainty of evidence was very low, which discourage unsubstantiated claims on the cardiovascular benefits of air purifiers. We have also identified several key methodological limitations, including small sample size, short duration of intervention, and the lack of wash-out period. Further RCTs with larger sample size and longer follow-up duration are needed to clarify the cardiovascular benefits of air purification interventions.

Carotid-Femoral Pulse Transit Time Variability Predicted Mortality and Improved Risk Stratification in the Elderly

[Figure: see text].

Ambulatory monitoring of central arterial pressure, wave reflections, and arterial stiffness in patients at cardiovascular risk

This paper reviews current 24 h ambulatory noninvasive technologies for pulse wave analysis (PWA) providing central arterial pressure, pulse wave velocity, and augmentation index and the scientific evidence supporting their use in the clinical management of patients with arterial hypertension or at risk for cardiovascular complications.The most outstanding value of these techniques lies in the fact that they are user-friendly, mostly operator independent, and enable the evaluation of vascular function during daily-life conditions, allowing to obtain repeated measurements in different out-of-office circumstances, less artificial than those of the laboratory or doctor's office.Studies performed so far suggest that 24 h PWA may represent a potentially promising tool for evaluating vascular function, structure, and damage in daily-life conditions and promoting early screening in subjects at risk. The current evidence in favor of such an approach in the clinical practice is still limited and does not recommend its routine use. In particular, at the moment, there is a shortage of long-term prognostic studies able to support the predictive value of 24 h PWA. Finally, the accuracy of the measures is strongly dependent on the type of technology and device employed with lack of interoperability among the devices that deeply affects comparability of results among studies using different technologies. It is thus mandatory in the near future to promote proper validation studies, for instance using the ARTERY protocol, and to plan well-designed long-term longitudinal studies that may prove the accuracy and high predictive value of PWA in ambulatory conditions.

Feasibility of non-invasive measurement of central blood pressure and arterial stiffness in shock

BACKGROUND

Patients in haemodynamic shock are in need for an intensive care treatment. Invasive haemodynamic monitoring is state of the art for these patients. However, evolved, non-invasive blood pressure monitoring devices offer advanced functions like the assessment of central blood pressure and arterial stiffness. We analysed the feasibility of two oscillometric blood pressure devices in patients with shock.

METHODS

We performed a monocentre prospective study, enrolling 57 patients admitted to the intensive care unit (ICU), due to septic and/or cardiogenic shock. We assessed invasive and non-invasive peripheral and central blood pressure <24 hours and 48 hours after admission on the ICU. Additional haemodynamic parameters such as pulse wave velocity (PWV), augmentation pressure and augmentation index were obtained through Mobil-o-Graph PWA (IEM) and SphygmoCor XCEL (AtCor Medical).

RESULTS

A complete haemodynamic assessment was successful in all patients (48) with the Mobil-o-Graph 24 hours PWA and in 29 patients with the SphygmoCor XCEL (P = .001), when cases of death or device malfunction were excluded. Reasons for failure were severe peripheral artery disease, haemodynamic instability, oedema and agitation. Invasive blood pressure showed a sufficient correlation with both devices; however, large differences between invasive and non-invasive techniques were recorded in Bland-Altmann analysis (P < .05 for all parameters). PWV differed between the two devices.

CONCLUSION

Non-invasive peripheral blood pressure measurement remains a rescue technique. However, non-invasive assessment of arterial stiffness and central blood pressure is possible in patients with septic or cardiogenic shock. Further studies are required to assess their clinical significance for patients in shock.

Estimated Arterial Stiffness and Prediction of Vascular Aging: The Rising of a New Era

Arterial stiffness has been associated with cardiovascular events and correlated with cardiovascular risk factors. In the new guidelines of the European Society of Hypertension, the evaluation of arterial stiffness, and specifically carotid-femoral pulse wave velocity (c-f PWV), was taken into account for the detailed screening of the hypertensive population. Despite the importance of arterial stiffness as a target organ damage, the measurement is time-consuming, not practical, needs expensive equipment and experienced staff. For all these reasons, c-f PWV is not recommended for the everyday clinical practice and its current use is restricted for research purposes. The importance of arterial properties in clinical practice and cardiovascular prevention is well known. Hence, the estimation of arterial stiffness and vascular health based on parameters that affect arterial stiffness, but without the use of a machine, is a new promising field. Furthermore, the relationship between age-related MRI abnormalities as well as ultrafast ultrasound with vascular effect gives a new promise for future vascular aging assessment.

Factors and Prognostic Significance of Impaired Exercise Tolerance in Women over 40 with Arterial Hypertension

The aim of this study was to identify factors influencing maximal oxygen uptake (VO_2max) and early identification of the profile of hypertensive women in the perimenopausal period at risk of heart failure. This study included 185 female patients. Regression analyses determined predictors of the lowest VO_2max (quartile 1: VO_2max < 17 mL/kg/min). Females with the lowest oxygen consumption had a significantly higher level of high sensitive cardiac Troponin T (hs-cTnT) (p = 0.001), higher values of the left atrial (LA) volume, late diastolic mitral annulus velocity (A′), E/E′ (p = 0.0003, p = 0.02, p = 0.04; respectively), higher BMI and fat content (kg and %) (p < 0.0001), higher fat free mass (FFM) (kg) (p < 0.0001), total body water content (TBW) (p = 0.0002) as well as extracellular body water content (ECW) (p < 0.0001) and intracellular body water content (ICW) (p = 0.005), ECW/TBW × 100% (p < 0.0001) and metabolic age (p < 0.0001) and lower E′ (p = 0.001) compared to controls. In a multiple logistic regression model independently associated with VO_2max were: ECW/TBW × 100% (OR 4.45, 95% CI: 1.77–11.21; p = 0.002), BMI (OR 7.11, 95% CI: 2.01–25.11; p = 0.002) and hs-cTnT level (OR 2.69, 95% CI: 1.23–5.91; p = 0.013). High-sensitivity cardiac troponin may serve as an early biomarker of heart failure in hypertensive women. Hydration status should be considered in overall hypertensive women care. There is an importance of body mass compartments analysis in the early identification of hypertensive females at risk of heart failure. Optimization and personalization of body structure may be a preventive method for this disease. ClinicalTrials.gov Identifier: NCT04802369.

Ultrasonography to detect cardiovascular damage in children with essential hypertension

Background

Essential hypertension in adults may begin in childhood. The damages to the heart and blood vessels in children with essential hypertension are hidden and difficult to detect. We noninvasively examined changes in cardiovascular structure and function in children with hypertension at early stage using ultrasonography.

Methods

All patients with essential hypertension admitted from March 2020 to May 2021 were classified into simple hypertension (group 1, n = 34) and hypertension co-existing with obesity (group 2, n = 11) isolation. Meanwhile 32 healthy children were detected as control heathly group (group 3). We used pulse-wave Doppler to measure carotid–femoral pulse wave velocity (cfPWV), intimal–medial thickness (cIMT) and distensibility of carotid artery (CD). Cardiac structure and function (left atrial diameter [LAD], left ventricular mass [LVM], LVM index [LVMI], relative wall thicknes [RWT], end-diastolic left ventricular internal diameter [LVIDd], diastolic interventricular septum thickness [IVSd], diastolic left ventricular posterior wall thickness [LVPWd], root diameter of aorta [AO], E peak, A peak, E' peak, A' peak, E/E' ratio, and E/A ratio) were measured by echocardiography.

Results

The cfPWV of children in group 1 and group 2 were significantly higher than healthy children in group 3. Significant differences were observed in LVM, LVMI, RWT, LVIDd, IVSd, LVPWd, LAD, A peak, E' peak, A' peak, and E/E’ among three groups.

Conclusion

Children and adolescents with essential hypertension demonstrate target organ damages in the heart and blood vessels.

Volume elastic modulus with exponential function of transmural pressure as a valid stiffness measure derived by photoplethysmographic volume-oscillometry in human finger and radial arteries: potential for arteriosclerosis screening

Noninvasive and convenient measurement of vascular stiffness is of considerable importance for early detection and treatment of arteriosclerosis. Volume elastic modulus ([Formula: see text]) is one of representative measures reflecting effective vascular elasticity that is strongly dependent upon blood pressure (BP) or transmural pressure ([Formula: see text] = mean BP - (externally applied pressure)). However, its nonlinear nature in terms of functional form has not been fully investigated in human vasculature. This paper therefore seeks to clarify the functional form of [Formula: see text] in the human finger and radial arteries based on photoplethysmographic volume-oscillometry developed for novel indirect BP measurement. Using a smartphone-based instrument specially designed for this study, [Formula: see text] values at various [Formula: see text] levels were obtained in 11 male and female volunteers with various ages. It was demonstrated that [Formula: see text] showed an exponential behavior with respect to [Formula: see text] changes, expressed as [Formula: see text] ([Formula: see text], α; constant) with a high coefficient of determination, the validity of which was also supported through theoretical derivation. Conclusively, the [Formula: see text] is found to increase exponentially with arterial distending pressure, and the independent measures [Formula: see text] and α would be useful parameters to conveniently evaluate progressive changes of vascular stiffness among and/or within individuals, indicating that this measurement has potential for arteriosclerosis screening (200/200). Schematic diagram of overall configuration of the measurement system of arterial elasticity in the finger and the wrist, consisting of a measuring, signal processing and control (MSC) unit (surrounded by the dashed line) and a smartphone for data display and storage. An occlusive cuff and a photoplethysmographic placement of LED and PD for the finger and the wrist are shown in the upper middle part. Measurement scenes of the finger and the wrist are also inset in the upper left and in the upper right part, respectively.

Vascular Ageing in Youth: A Call to Action

Extensive evidence shows that risk factors for cardiovascular disease (CVD) begin to develop early in life. Childhood obesity and elevated blood pressure (BP) have become overwhelmingly challenging, with 57% of today's children predicted to be obese by the age of 35 years, and global rates of hypertension in children and adolescents increasing by 75% from 2000 to 2015. Thus, there is an urgent need for tools that can assess early CVD risk in youth, which may lead to better risk stratification, preventative intervention, and personalised medicine. Vascular ageing (the deterioration in vascular structure and function) is a pivotal progenitor of health degeneration associated with elevated BP. Exposure to adverse environmental and genetic factors from fetal life promotes the development and accumulation of subclinical vascular changes that direct an individual towards a trajectory of early vascular ageing (EVA)-an independent predictor of target organ damage in the heart, brain, and kidneys. Therefore, characterising vascular ageing from youth may provide a window into cardiovascular risk later in life. However, vascular ageing measurements only have value when techniques are accurate/validated and when reliable thresholds are available for defining normal ranges and ranges that signal increased risk of disease. The aim of this paper is to summarise current evidence on the importance of vascular ageing assessment in youth and the impact of interventions to prevent or delay EVA, to highlight the need for standardisation and validation of measurement techniques in children and adolescents, and the importance of establishing reference values for vascular ageing measures in this population.

Pathophysiology and consequences of arterial stiffness in children with chronic kidney disease

Changes in arterial structure and function are seen early in the course of chronic kidney disease (CKD) and have been causally associated with cardiovascular (CV) morbidity. Numerous potential injuries encompassing both traditional and uremia-specific CV risk factors can induce structural arterial changes and accelerate arterial stiffening. When the buffering capacity of the normally elastic arteries is reduced, damage to vulnerable microcirculatory beds can occur. Moreover, the resultant increase to cardiac afterload contributes to the development of left ventricular hypertrophy and cardiac dysfunction. Adult studies have linked arterial stiffness with increased risk of mortality, CV events, cognitive decline, and CKD progression. Pulse wave velocity (PWV) is currently the gold standard of arterial stiffness assessment but its measurement in children is challenging due to technical difficulties and physiologic aspects related to growth and poor standardization between algorithms for calculating PWV. Nevertheless, studies in pediatric CKD have reported increased arterial stiffness in children with advanced CKD, on dialysis, and after kidney transplantation. Development of arterial stiffness in children with CKD is closely related to mineral-bone disease and hypertension, but other factors may also play a significant role. The clinical relevance of accelerated arterial stiffness in childhood on cardiovascular outcomes in adult life remains unclear, and prospective studies are needed. In this review we discuss mechanisms leading to arterial stiffness in CKD and its clinical implications, along with issues surrounding the technical aspects of arterial stiffness assessment in children.

Non-Invasive Methods for PWV Measurement in Blood Vessel Stiffness Assessment

In recent years, statistical studies highlighted an increasing incidence of cardiovascular diseases (CVD) which reflected on additional costs on the healthcare systems worldwide. Pulse wave velocity (PWV) measurement is commonly considered a CVD predictor factor as well as a marker of Arterial Stiffness (AS), since it is closely related to the mechanical characteristics of the arterial wall. An increase in PWV is due to a more rigid arterial system. Because of the prevalence of the elastic component, in young people the PWV is lower than in the elderly. Nowadays, invasive and non-invasive methods for PWV assessment are employed: there is an increasing attention in the development of non-invasive devices which mostly perform a regional PWV measurement (over a long arterial portion) rather than local (over a short arterial portion). The accepted gold-standard for non-invasive AS measurement is the carotid-femoral PWV used to evaluate the arterial damage, the corresponding cardiovascular risk and to adapt the proper therapy. This review article considers the main commercially available devices underlining their operating principles in terms of sensors, execution mode, pulse waveform acquired, site of measurement, distance and time estimation methods, as well as their main limitations in clinical practice.

Brachial-ankle pulse wave velocity and cardio-ankle vascular index are associated with future cardiovascular events in a general population: The Nagahama Study

Faster pulse wave velocity (PWV) is known to be associated with the incidence of cardiovascular diseases (CVD). The aim of this study was to clarify the hypothesis that PWV may be associated with future CVD events even when its time-dependent changes were adjusted. We also investigated a prognostic significance of cardio-ankle vascular index, another index of arterial stiffness. Study participants included 8850 community residents. The repeated measures of the clinical parameters at 5.0 years after the baseline were available for 7249 of the participants. PWV was calculated using the arterial waveforms measured at the brachia and ankles (baPWV). The cardio-ankle vascular index was calculated by estimated pulse transit time from aortic valve to tibial artery. During the 8.53 years follow-up period, we observed 215 cases of CVD. The incidence rate increased linearly with baPWV quartiles (per 10 000 person-years: Q1, 2.7; Q2, 12.6; Q3, 22.5; Q4, 76.2), and the highest quartile was identified as an independent determinant of incident CVD by conventional Cox proportional hazard analysis adjusted for known risk factors [hazard ratio (HR), 4.00; p = .007]. Per unit HR of baPWV (HR, 1.15; p < .001) remained significant in the time-dependent Cox regression analysis including baPWV and other clinical values measured at 5-year after the baseline as time-varying variables (HR, 1.14; p < .001). The cardio-ankle vascular index was also associated with CVD with similar manner though the associations were less clear than that of baPWV. baPWV is a good risk marker for the incidence of CVD.

Sex differences in arterial wave reflection and the role of exogenous and endogenous sex hormones: results of the Berlin Aging Study II

BACKGROUND

Arterial stiffness is tightly linked to hypertension. Sex differences in hypertension and arterial stiffness have already been established, yet the role of sex hormones is not precisely defined. This study examined age and sex differences of arterial wave reflection and associations with endogenous and exogenous sex hormones in women.

METHODS

Pulse wave analysis was performed with an oscillometric device in 590 male and 400 female participants of the Berlin Aging Study II. Participants have been recruited from two age-strata, 22-35 years and 60-82 years. Data on exposures and potential confounders, including medication, have been collected at baseline visit.

RESULTS

Aumentation index (AIx) and pulse wave velocity increased with age. Mean AIx was higher in women than in men. Multivariable regression analysis showed a positive association between use of oral contraceptive pills (OCPs) and AIx controlling for confounders (age, BMI, current smoking, central blood pressure), with a significantly higher mean AIx in OCP-users compared with nonusers (mean group difference: 4.41; 95% confidence interval 1.61-7.22). Per quartile decrease in estradiol level AIx increased by 1.72 (95% confidence interval 0.43-3.00). In OCP users endogenous estradiol was largely suppressed.

CONCLUSION

The findings suggest important sex differences in measures of arterial wave reflection, with a higher mean AIx observed in women compared with men. OCPs may promote the development of hypertension by increasing AIx. Suppressed endogenous estradiol levels may be responsible for this increased wave reflection due to increased vasotonus of the small and medium arteries.

Development of a novel CT-derived measure of cardiovascular health: the CT aortic stiffness index (CTASI)

AIMS

Aortic stiffness, measured as aortic pulse wave velocity (PWV), is a powerful predictor of cardiovascular health but is difficult to accurately obtain non-invasively. This study sought to develop a novel CT aortic stiffness index (CTASI) which incorporates both anatomical (calcification) and physiological (distensibility) aspects of aortic health.

METHODS

Invasive PWV and CT scans were obtained for 80 patients undergoing TAVI (cohort 1). CT data alone were obtained from an additional 238 patients (cohort 2). Aortic calcification was quantified using a modified Agatston's methodology. Distensibility-PWV was calculated from minimum and maximum ascending aorta areas. Linear regression of these values was used to construct CTASI from cohort 1. CTASI was then calculated for cohort 2 who were prospectively followed-up.

RESULTS

CTASI correlated with invasive PWV (rho = 0.47, p < 0.01) with a higher correlation coefficient than distensibility-PWV (rho = 0.35, p < 0.01) and aortic calcification (rho = 0.36, p < 0.01). Compared to invasive PWV, CTASI had a good accuracy as a diagnostic test (AOC 0.72 [95% CI 0.61-0.84]), superior to aortic calcification and distensibility-PWV alone (χ² = 0.82, p = 0.02). There were 61 deaths during a median follow-up of 771 days (95% CI 751.4-790.5). CTASI was able to predict 1-year mortality (OR 2.58, 95% CI 1.18-5.61, p = 0.02) and Kaplan-Meier survival (log-rank p = 0.03).

CONCLUSION

CTASI is a stronger measure of aortic stiffness than aortic calcification or distensibility alone. Given the prolific use of CT scanning for assessing coronary and vascular disease, the additional calculation of CTASI during these scans could provide an important direct measurement of vascular health and guide pharmacological therapy.

Serum Osteoprotegerin and Carotid Intima-Media Thickness Are Related to High Arterial Stiffness in Heart Failure with Reduced Ejection Fraction

Arterial stiffness (AS) is a complex vascular phenomenon with consequences for central hemodynamics and left-ventricular performance. Circulating biomarkers have been associated with AS; however, their value in heart failure is poorly characterized. Our aim was to evaluate the clinical and biomarker correlates of AS in the setting of heart failure with reduced ejection fraction (HFrEF). In 78 hospitalized, hemodynamically stable patients (20 women, 58 men, mean age 65.8 ± 1.41 years) with HFrEF, AS was measured using aortic pulse wave velocity (PWV). Serum OPG, RANKL, sclerostin, and DKK-1 were determined, and the relationships between the clinical variables, vascular-calcification-related biomarkers, and PWV were evaluated by correlation analysis and linear and logistic regression models. OPG and the OPG/RANKL ratio were significantly higher in the group of patients (n = 37, 47.4%) with increased PWV (>10 m/s). PWV was positively correlated with age, left-ventricular ejection fraction, and carotid intima-media thickness (cIMT), and negatively correlated with the glomerular filtration rate. OPG and cIMT were significantly associated with PWV in the logistic regression models when adjusted for hypertension, EF, and the presence of atherosclerotic manifestations. Elevated serum OPG, together with cIMT, were significantly related to increased AS in the setting of HFrEF.

Ultrasound Methods in the Evaluation of Atherosclerosis: From Pathophysiology to Clinic

Atherosclerosis is a key pathological process that causes a plethora of pathologies, including coronary artery disease, peripheral artery disease, and ischemic stroke. The silent progression of the atherosclerotic disease prompts for new surveillance tools that can visualize, characterize, and provide a risk evaluation of the atherosclerotic plaque. Conventional ultrasound methods-bright (B)-mode US plus Doppler mode-provide a rapid, cost-efficient way to visualize an established plaque and give a rapid risk stratification of the patient through the Gray-Weale standardization-echolucent plaques with ≥50% stenosis have a significantly greater risk of ipsilateral stroke. Although rather disputed, the measurement of carotid intima-media thickness (C-IMT) may prove useful in identifying subclinical atherosclerosis. In addition, contrast-enhanced ultrasonography (CEUS) allows for a better image resolution and the visualization and quantification of plaque neovascularization, which has been correlated with future cardiovascular events. Newly emerging elastography techniques such as strain elastography and shear-wave elastography add a new dimension to this evaluation-the biomechanics of the arterial wall, which is altered in atherosclerosis. The invasive counterpart, intravascular ultrasound (IVUS), enables an individualized assessment of the anti-atherosclerotic therapies, as well as a direct risk assessment of these lesions through virtual histology IVUS.

Central pulse pressure is inversely associated with proximal aortic remodelling

OBJECTIVES

Hypertension leads to aortic stiffening and dilatation but unexpected data from the Framingham Heart Study showed an inverse relationship between brachial pulse pressure and aortic diameter. Aortic dilatation would not only lead to lower pulse pressure but also to a worse prognosis (cardiac events, heart failure). Invasive pressure may be more informative but data are lacking.

AIM

This study evaluated the relationship between invasively measured central blood pressure and proximal aortic diameter.

METHODS

In 71 consecutive patients referred to invasive haemodynamic study, proximal aortic remodelling was evaluated in terms of Z-score, comparing diameters measured at the sinus of Valsalva to the diameter expected according to patients' age, sex and body height. Pressures were recorded directly in the proximal aorta by means of a catheter before coronary assessment.

RESULTS

The mean invasive aortic SBPs and DBPs were 146 ± 23 and 78 ± 13 mmHg, respectively, giving a central pulse pressure (cPP inv) of 68 ± 21 mmHg. Proximal aortic diameter was 34.9 ± 19.4 mm, whereas Z-score was -0.3 ± 1.7. Patients with higher cPPinv showed a significantly lower Z-score (-0.789 vs. 0.155, P = 0.001). cPPinv was inversely related to Z-score (R = -0.271, P = 0.022) independently from age, mean blood pressure and heart rate (β = -0.241, P = 0.011).

CONCLUSION

Aortic root Z-score is inversely associated with invasively measured central pulse pressure in a cohort of patients undergoing invasive coronary assessment. Remodelling at the sinuses of Valsalva may be a compensatory mechanism to limit pulse pressure.

Connecting vascular aging and frailty in Alzheimer's disease

Aging plays an important role in the etiology of the most common age-related diseases (ARDs), including Alzheimer's disease (AD). The increasing number of AD patients and the lack of disease-modifying drugs warranted intensive research to tackle the pathophysiological mechanisms underpinning AD development. Vascular aging/dysfunction is a common feature of almost all ARDs, including cardiovascular (CV) diseases, diabetes and AD. To this regard, interventions aimed at modifying CV outcomes are under extensive investigation for their pleiotropic role in ameliorating and slowing down cognitive impairment in middle-life and elderly individuals. Evidence from observational and clinical studies confirm the notion that the earlier the interventions are conducted, the most favorable are the effects on cognitive function. Therefore, epidemiological research should focus on the early detection of deviations from a healthy cognitive aging trajectory, through the stratification of adult individuals according to the rate of aging. Here, we review the interplay between vascular and cognitive dysfunctions associated with aging, to disentangle the complex mechanisms underpinning the development and progression of neurodegenerative disorders, with a specific focus on AD.

A New Noninvasive System for Clinical Pulse Wave Velocity Assessment: The Athos Device

This paper presents a low cost, noninvasive, clinical-grade Pulse Wave Velocity evaluation device. The proposed system relies on a simultaneous acquisition of femoral and carotid pulse waves to improve estimation accuracy and correctness. The sensors used are two high precision MEMS force sensors, encapsulated in two ergonomic probes, and connected to the main unit. Data are then wirelessly transmitted to a standard laptop, where a dedicated graphical user interface (GUI) runs for analysis and recording. Besides the interface, the Athos system provides a Matlab algorithm to process the signals quickly and achieve a reliable PWV assessment. To better compare the results at the end of each analysis, a detailed report is generated, including all the relevant examination information (subject data, mean PTT, and obtained PWV). A pre-clinical study was conducted to validate the system by realizing several Pulse Wave Velocity measurements on ten heterogeneous healthy subjects of different ages. The collected results were then compared with those measured by a well-established and largely more expensive clinical device (SphygmoCor).

Carotid Beta Stiffness Association with Thyroid Function

Background: Thyroid hormone modulation of cardiovascular function has been associated with cardiovascular disease. Recent evidence suggests that free thyroxine (FT4) levels are associated with an increase in systemic arterial stiffness, but little is known about the effects of FT4 at the local level of the common carotid artery. β-stiffness index is a local elastic parameter usually determined by carotid ultrasound imaging. Methods: We conducted a cross-sectional analysis in the ProgeNIA cohort, including 4846 subjects across a broad age range. For the purpose of this study, we excluded subjects with increased thyrotropin (TSH) levels and those treated with levothyroxine or thyrostatic. We assessed β stiffness, strain, wall–lumen ratio, carotid cross-sectional area (CSA), and stress and flow in the right common carotid artery. We tested whether FT4, heart rate, and their interactions were associated with carotid parameters. Results: FT4 was positively and independently associated with β stiffness index (β = 0.026, p = 0.041), and had a negative association with strain (β = −0.025, p = 0.009). After adding heart rate and the interaction between FT4 and heart rate to the model, FT4 was still associated with the β stiffness index (β = 0.186, p = 0.06), heart rate was positively associated with the stiffness index (β = 0.389, p < 0.001) as well as their interaction (β = 0.271, p = 0.007). Conclusion: This study suggests that higher FT4 levels increase arterial stiffness at the common carotid level, consistent with a detrimental effect on elastic arteries. The effect of FT4 is likely to be primarily attributable to its effect on heart rate.

Local transversal aortic strain is impaired in ascending aorta dilatation

BACKGROUND

Ascending aorta dilatation is found in 13% of hypertensive patients. Little is known about elastic properties of ascending aorta in such patients. Echo-based transverse aortic strain analysis can describe mechanical properties of ascending aorta but has never been applied to patients with ascending aorta dilatation.

AIM

To assess mechanical properties of ascending aorta by transverse aortic strain analysis (as β2-stiffness index) in hypertensive patients with ascending aorta dilatation and association between mechanical properties of ascending aorta and cardiovascular damage.

METHODS

A total of 100 hypertensive outpatients underwent transthoracic echocardiography and assessment of pulse wave velocity (PWV). Strain analysis of ascending aorta was performed with echocardiographic speckle-tracking software. Patients were divided in three groups based on ascending aorta diameter: less than 40, 40-45, and at least 45 mm.

RESULTS

Beta-SI increased exponentially with ascending aorta dimensions (P < 0.001). Patients with ascending aorta dilatation had Beta-SI significantly higher than those with normal ascending aorta diameter. A greater proportion of patient with impaired (i.e., elevated) Beta-SI was present in groups with larger ascending aorta (18.2 vs. 48.4 vs. 80%, respectively, P < 0.05). On multivariate logistic regression only impaired Beta-SI predicted ascending aorta dilatation (P < 0.001). Beta-SI was related to cardiovascular damage in terms of left ventricular (LV) mass (LV mass indexed to BSA, P = 0.030) and PWV (P = 0.028). Patients with high Beta-SI had greater LV mass indexed to BSA (117 ± 47 vs. 94 ± 24 g/m2; P = 0.010) and PWV (10.20 ± 2.99 vs. 8.63 ± 1.88 m/s; P = 0.013).

CONCLUSION

Ascending aorta dilatation is associated with increased local aortic stiffness in hypertensive patients. Strain analysis adds functional information to the mere morphological evaluation of aortic diameter and could be a useful tool to better define cardiovascular risk in this population.

The cuffless SOMNOtouch NIBP device shows poor agreement with a validated oscillometric device during 24-h ambulatory blood pressure monitoring

Repeated cuff‐based blood pressure (BP) measurements may cause discomfort resulting in stress and erroneous recording values. SOMNOtouch NIBP is an alternative cuff‐less BP measurement device that calculates changes in BP based on changes in pulse transit time (PTT) and a software algorithm. The device is calibrated with a single upper arm cuff‐based BP measurement. We tested the device against a validated 24‐h ambulatory BP monitoring (ABPM) device using both the previous (SomBP1) and the current software algorithm (SomBP2). In this study, 51 patients (mean age ± SD 61.5 ± 13.0 years) with essential hypertension underwent simultaneous 24‐h ABPM with the SOMNOtouch NIBP on the left arm and a standard cuff‐based oscillometric device on the right arm (OscBP). We found that mean daytime systolic BP (SBP) with OscBP was 140.8 ± 19.7 compared to 148.0 ± 25.2 (P = .008) and 146.9 ± 26.0 mmHg (P = .034) for SomBP1 and SomBP2, respectively. Nighttime SBP with OscBP was 129.5 ± 21.1 compared with 146.1 ± 25.8 (P < .0001) and 141.1 ± 27.4 mmHg (P = .001) for SomBP1 and SomBP2, respectively. Ninety‐five% limits of agreement between OscBP and SomBP1 were ± 36.6 mmHg for daytime and ± 42.6 mmHg for nighttime SBP, respectively. Agreements were not improved with SomBP2. For SBP, a nocturnal dipping pattern was found in 33% of the study patients when measured with OscBP but only in 2% and 20% with SomBP1 and ‐2, respectively. This study demonstrates that BP values obtained with the cuff‐less PTT‐based SOMNOtouch device should be interpreted with caution as these may differ substantially from what would be obtained from a validated cuff‐based BP device.

Metabolically Healthy Obesity: Presence of Arterial Stiffness in the Prepubescent Population

Aim: Arteriosclerotic cardiovascular disease, one of the world’s leading causes of death, first manifests itself at an early age. The identification of children who may have increased cardiovascular risk in the future could be an important prevention strategy. Our aim was to assess the clinical, analytical, and dietary variables associated with arterial stiffness (AS), measured by carotid-femoral pulse wave velocity (cfPWV) in a prepubescent population with metabolically healthy obesity (MHO). Subjects and Methods: A cross-sectional study in prepubescent subjects with obesity who had ≤1 metabolic syndrome criteria (abdominal perimeter and blood pressure ≥90th percentile, triglycerides >150 mg/dL, HDL-cholesterol <40 mg/dL, fasting plasma glucose ≥100 mg/dL) was conducted. Adherence to Mediterranean Diet, blood pressure, BMI, waist/height ratio (WHtR), glycemic status, lipid profile, and cfPWV were analyzed. 75 MHO children (boys: 43; girls: 32; p = 0.20) (age = 10.05 ± 1.29 years; BMI = 25.29 ± 3.5 kg/m2) were included. Results: We found a positive correlation between cfPWV and weight (r = 0.51; p < 0.0001), BMI (r = 0.44; p < 0.0001), WHtR (r = 0.26; p = 0.02), fasting insulin levels (r = 0.28; p = 0.02), and insulin resistance (Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) index) (r = 0.25; p = 0.04). Multiple linear regression analysis identified BMI and HOMA-IR as independent parameters associated with cfPWV. Conclusions: Prepubescent children with obesity who were shown to be metabolically healthy presented with arterial stiffness, which is closely related to BMI and the state of insulin resistance.

A novel angle extremum maximum method for recognition of pulse wave feature points

BACKGROUND AND OBJECTIVES

Pulse wave is one of the biomedical signals that has been studied over the past years. Accurate recognition of feature points is the basis of verifying the connections between pulse waves and certain diseases. Therefore, the aim of the study is to discuss the use of angle mapping on feature points recognition.

METHODS

The mathematical method is based on the application of angle curve with parameter " k " on pulse wave. The data used is collected by PVDF sensor. Approximate curve and mathematical model are used for the discussion of the influence of parameter k and pulse wave amplitude by numerical calculation. The conclusion drawn from the numerical solution is that when k changes to maximize the angle extremum value, the corresponding position of angle extremum point is the feature point position. For the sampling rate f = 455Hz in this paper, k can be taken from 5 to 15.

RESULTS

We present the recognition results of unobvious feature points based on the "angle extremum maximum method" and corresponding angle values. The results are compared with traditional methods and the determination of angle threshold value is discussed.

CONCLUSIONS

This method can be used for accurate and efficient feature points identification, and it can be better applied to pulse waves with noise or unobvious feature points.

How to Measure Arterial Stiffness in Humans

Despite the wide recognition of larger artery stiffness as a highly clinically relevant and independent prognostic biomarker, it has yet be incorporated into routine clinical practice and to take a more prominent position in clinical guidelines. An important reason may be the plethora of methods and devices claiming to measure arterial stiffness in humans. This brief review provides a concise overview of methods in use, indicating strengths and weaknesses. We classified and graded methods, highly weighing their scrutiny and purity in quantifying arterial stiffness, rather than focusing on their ease of application or the level at which methods have demonstrated their prognostic and diagnostic potential.

Improvement in arterial stiffness (pOpmètre®) after bariatric surgery. Results from a prospective study

BACKGROUND

Arterial stiffness (AS) is an independent predictor of cardiovascular risk, and could be used as a surrogate marker of improvement in cardiovascular risk following bariatric surgery. The aim of this study was to compare AS before and after surgery.

METHODS

One hundred and thirty-four patients undergoing bariatric surgery between May 2016 and January 2019 were prospectively included. AS was measured on pulse wave velocity (PWV) with the pOpmètre® device pre- and postoperatively. The main endpoint was change in PWV between baseline and 3 months post-surgery.

RESULTS

Overall, mean PWV was 6.87m/s preoperatively and 6.71m/s at 3 months (P=0.7148). Patients with pathologic PWV (>2 standard deviations from expected value for age) showed significant improvement at 3 months (31 patients; 10.1m/s preoperatively vs 7.5m/s at 3 months; P=0.007). These results did not correlate with improvement in other clinical or biological parameters following surgery (excess weight loss, mean blood pressure, fasting blood glucose, waist circumference, body composition).

CONCLUSION

These results suggest that pathological arterial stiffness may resolve following bariatric surgery independently of the other factors influencing cardiovascular risk in obesity.

Pulse wave velocity and short-term outcome in patients requiring intravascular volume expansion: a pilot study

BACKGROUND

Fluid therapy has a pivotal role in the management of acutely ill patients. However, whether or not a patient can tolerate additional intravascular volume is controversial and optimal strategy is unknown. Carotid femoral pulse wave velocity (cfPWV) evaluates arterial stiffness.

OBJECTIVE

To determine whether cfPWV can predict the ability of patients to tolerate clinically indicated acute fluid expansion.

METHODS

50 consecutive patients requiring intravascular volume expansion were prospectively recruited in intensive care units. All subjects underwent transthoracic echocardiography, pulmonary ultrasound assessment, and a cfPWV study (S. Giovanni Bosco Hospital in Turin, Italy, between 2015 and 2016) at baseline and after 24 hours. Acute outcomes were registered at 24 hours ("soft" end points) and 30 days ('hard' end points: death, acute myocardial infarction, stroke, occurrence of atrial fibrillation, need for dialysis) after initial fluid therapy. Multivariate logistic regression was used to assess association of the initial cfPWV with outcomes.

RESULTS

cfPWV was significantly higher (10.6±3.6 vs 7.4±2.2 m/s, P<0.0001) in subjects who met the prespecified combined endpoints (hard or soft) than in those who did not. After adjustment for confounding factors, initial cfPWV was significantly and independently associated with the occurrence of hard events (OR=2.8 (95% CI 1.36 to 5.97), P=0.005; area under the receiver operating characteristic curve 84%). cfPWV of <9 m/s had a negative predictive value of 93%, excluding hard events associated with fluid expansion.

CONCLUSION

cfPWV appears to reflect the ability of the patient to tolerate an intravascular fluid expansion when clinically indicated. Increased cfPWV could help to identify subjects at greater risk of developing signs and symptoms of fluid overload.

Non-Invasive Device for Blood Pressure Wave Acquisition by Means of Mechanical Transducer

Blood pressure wave monitoring provides interesting information about the patient’s cardiovascular function. For this reason, this article proposes a non-invasive device capable of capturing the vibrations (pressure waves) produced by the carotid artery by means of a pressure sensor encapsulated in a closed dome filled with air. When the device is placed onto the outer skin of the carotid area, the vibrations of the artery will exert a deformation in the dome, which, in turn, will lead to a pressure increase in its inner air. Then, the sensor inside the dome captures this pressure increase. By combining the blood pressure wave obtained with this device together with the ECG signal, it is possible to help the screening of the cardiovascular system, obtaining parameters such as heart rate variability (HRV) and pulse transit time (PTT). The results show how the pressure wave has been successfully obtained in the carotid artery area, discerning the characteristic points of this signal. The features of this device compare well with previous works by other authors. The main advantages of the proposed device are the reduced size, the cuffless condition, and the potential to be a continuous ambulatory device. These features could be exploited in ambulatory tests.

A Low Tacrolimus Concentration/Dose Ratio Increases the Risk for the Development of Acute Calcineurin Inhibitor-Induced Nephrotoxicity

Fast tacrolimus metabolism is linked to inferior outcomes such as rejection and lower renal function after kidney transplantation. Renal calcineurin-inhibitor toxicity is a common adverse effect of tacrolimus therapy. The present contribution hypothesized that tacrolimus-induced nephrotoxicity is related to a low concentration/dose (C/D) ratio. We analyzed renal tubular epithelial cell cultures and 55 consecutive kidney transplant biopsy samples with tacrolimus-induced toxicity, the C/D ratio, C0, C2, and C4 Tac levels, pulse wave velocity analyses, and sublingual endothelial glycocalyx dimensions in the selected kidney transplant patients. A low C/D ratio (C/D ratio < 1.05 ng/mL×1/mg) was linked with higher C2 tacrolimus blood concentrations (19.2 ± 8.7 µg/L vs. 12.2 ± 5.2 µg/L respectively; p = 0.001) and higher degrees of nephrotoxicity despite comparable trough levels (6.3 ± 2.4 µg/L vs. 6.6 ± 2.2 µg/L respectively; p = 0.669). However, the tacrolimus metabolism rate did not affect the pulse wave velocity or glycocalyx in patients. In renal tubular epithelial cells exposed to tacrolimus according to a fast metabolism pharmacokinetic profile it led to reduced viability and increased Fn14 expression. We conclude from our data that the C/D ratio may be an appropriate tool for identifying patients at risk of developing calcineurin-inhibitor toxicity.

Association Between HDL Cholesterol and QTc Interval: A Population-Based Epidemiological Study

Previous experimental studies showed that increasing high-density lipoprotein cholesterol (HDL) cholesterol shortens cardiac ventricular repolarization and the QT interval corrected for heart rate (QTc). However, little is known about the epidemiological relationship between HDL and QTc. The potential antiarrhythmic effect of HDL cholesterol remains a speculative hypothesis. In this cross-sectional population based study in adults living in the Italian-speaking part of Switzerland, we aimed to explore the association between HDL cholesterol and the QTc interval in the general population. A total of 1202 subjects were screened. electrocardiogram (ECG) recordings, measurements of lipid parameters and other laboratory tests were performed. QTc was corrected using Bazett’s (QTc_Baz) and Framingham (QTc_Fram) formulas. HDL was categorized according to percentile distributions: <25th (HDL-1; ≤1.39 mmol/L); 25th–<50th (HDL-2; 1.40–1.69 mmol/L); 50th–<75th (HDL-3; 1.69–1.99 mmol/L); and ≥75th (HDL-4; ≥2.0 mmol/L). After exclusion procedures, data of 1085 subjects were analyzed. Compared with the HDL reference group (HDL-1), HDL-2 and HDL-3 were associated with a reduction of QTc_Baz and QTc_Fram duration in crude (HDL-2, QTc_Baz/QTc_Fram: β-11.306/–10.186, SE 4.625/4.016; p = 0.016/0.012; HDL-3, β-12.347/–12.048, SE 4.875/4.233, p = 0.012/<0.001) and adjusted (HDL-2: β-11.697/–10.908, SE 4.333/4.151, p < 0.001/0.010; HDL-3 β-11.786/–11.002, SE 4.719/4.521, p = 0.014/0.016) linear regression models in women. In adjusted logistic regression models higher HDL, were also associated with lower risk of prolonged QTc_Baz/QTc_Fram (HDL-2: OR 0.16/0.17, CI 0.03–0.83/0.47–0.65; HDL-3: OR 0.10/0.14, CI 0.10–0.64/0.03–0.63) in women. Restricted cubic spline analysis confirmed a non linear association (p < 0.001). The present findings indicate an epidemiological association between HDL cholesterol and QTc duration. To draw firm conclusions, further investigations in other populations and with a prospective cohort design are needed.

Noninvasive Assessment of Aortic Pulse Wave Velocity by the Brachial Occlusion-Cuff Technique: Comparative Study

Cardiovascular diseases are one of most frequent cause of morbidity and mortality in the world. There is an emerging need for integrated, non-invasive, and easy-to-use clinical tools to assess accurately cardiovascular system primarily in the preventative medicine. We present a novel design for a non-invasive pulse wave velocity (PWV) assessment method integrated in a single brachial blood pressure monitor allowing for up to 100 times more sensitive recording of the pressure pulsations based on a brachial occlusion-cuff (suprasystolic) principle. The monitor prototype with built-in proprietary method was validated with a gold standard reference technique SphygmoCor VX device. The blood pressure and PWV were assessed on twenty-five healthy individuals (9 women, age (37 ± 13) years) in a supine position at rest by a brachial cuff blood pressure monitor prototype, and immediately re-tested using a gold standard method. PWV using our BP monitor was (6.67 ± 0.96) m/s compared to PWV determined by SphygmoCor VX (6.15 ± 1.01) m/s. The correlation between methods using a Pearson’s correlation coefficient was r = 0.88 (p < 0.001). The study demonstrates the feasibility of using a single brachial cuff build-in technique for the assessment of the arterial stiffness from a single ambulatory blood pressure assessment.