Radiofrequency-based carotid wall tracking: a comparison between two different systems

Role of Preoperative Ultrasound Shear-Wave Elastography and Radiofrequency-Based Arterial Wall Tracking in Assessing the Vulnerability of Carotid Plaques: Preliminary Results

We aimed at evaluating the ability of point shear-wave elastography (pSWE) and of a radiofrequency (RF) echo-tracking-based method in preoperatively assessing the vulnerability of the carotid plaque in patients undergoing carotid endarterectomy (CEA) for significant asymptomatic stenosis. All patients who underwent CEA from 03/2021 to 03/2022 performed a preoperative pSWE and an RF echo-based wall evaluation of arterial stiffness using an Esaote MyLab ultrasound system (EsaoteTM, Genova, Italy) with dedicated software. The data derived from these evaluations (Young's modulus (YM), augmentation index (AIx), pulse-wave velocity (PWV)) were correlated with the outcome of the analysis of the plaque removed during the surgery. Data were analyzed on 63 patients (33 vulnerable and 30 stable plaques). In stable plaques, YM was significantly higher than in vulnerable plaques (49.6 + 8.1 kPa vs. 24.6 + 4.3 kPa, p = 0.009). AIx also tended to be slightly higher in stable plaques, even if it was not statistically significant (10.4 + 0.9% vs. 7.7 + 0.9%, p = 0.16). The PWV was similar (12.2 + 0.9 m/s for stable plaques vs. 10.6 + 0.5 m/s for vulnerable plaques, p = 0.16). For YM, values >34 kPa had a sensitivity of 50% and a specificity of 73.3% in predicting plaque nonvulnerability (area under the curve = 0.66). Preoperative measurement of YM by means of pSWE could be a noninvasive and easily applicable tool for assessing the preoperative risk of plaque vulnerability in asymptomatic patients who are candidates for CEA.

Ambulatory and successive home-based heart rate targeted aerobic training improves arterial parameters: a follow-up study in people with metabolic syndrome

BACKGROUND

Studies demonstrated that outpatient aerobic exercise programs (aEP) can significantly decrease aortic stiffness in people with metabolic syndrome (MetS). There is some limited data that remotely supervised home-based aEP can also improve arterial stiffness in this population. We aimed to evaluate the changes in the arterial wall parameters after the 2-month ambulatory supervised aEP followed by the 6-month home-based aEP with and without targeting of heart rate (HR) by electrocardiogram (ECG) in people with MetS.

METHODS

In this prospective study (ClinicalTrials.gov identifier: NCT05592704) 132 MetS subjects (mean age 52.44 ± 6.26 years, 54.55% female) were evaluated. At first, all subjects participated in the 2-month ambulatory supervised aEP, which consisted of 40 individual aerobic training sessions on a cycle ergometer 5 times/week for 40 min and received the recommendations for home-based training. Then the study (n = 66) and the control (n = 66) groups participated in the 6-month home-based aEP, but only the study group subjects targeted their HR using ECG monitor connected to the smartphone during workouts. Arterial stiffness parameters and carotid artery intima-media thickness (cIMT) were evaluated in all participants at baseline and after 8 months.

RESULTS

After 8 months, carotid-femoral pulse wave velocity (c-f PWV) significantly reduced in both groups (-12.22% in the study group vs. -7.85% in the control group, all p < .001) without a significant between-group difference (p = 0.144). A significant improvement of carotid-radial pulse wave velocity (c-r PWV) was observed only in the study group (-11.37%, p < .001, d = -0.671) with significant between-group difference (p < .001). The reduction of c-r PWV after 8 months of aEP occurred when c-r PWV at baseline was in the 2nd quartile (>7.90 m/s). A significant decrease of 3.32% in cIMT was present only in the study group (p = .032, d = -0.288).

CONCLUSIONS

The combination of 2-month ambulatory supervised aEP and successive 6-month home-based aEP targeted by HR monitoring using ECG improved arterial properties in MetS subjects more than the same combination without HR targeting, leading to the greater reduction of c-r PWV and cIMT.

Detectable Bias between Vascular Ultrasound Echo-Tracking Systems: Relevance Depends on Application

The Esaote MyLab70 ultrasound system has been extensively used to evaluate arterial properties. Since it is reaching end-of-service-life, ongoing studies are forced to seek an alternative, with some opting for the Esaote MyLabOne. Biases might exist between the two systems, which, if uncorrected, could potentially lead to the misinterpretation of results. This study aims to evaluate a potential bias between the two devices. Moreover, by comparing two identical MyLabOne systems, this study also aims to investigate whether biases estimated between the MyLabOne and MyLab70 employed in this study could be generalized to any other pair of similar scanners. Using a phantom set-up, we performed n = 60 measurements to compare MyLab70 to MyLabOne and n = 40 measurements to compare the two MyLabOne systems. Comparisons were performed to measure diameter, wall thickness, and distension. Both comparisons led to significant biases for the diameter (relative bias: −0.27% and −0.30% for the inter- and intra-scanner model, respectively, p < 0.05) and wall thickness (relative bias: 0.38% and −1.23% for inter- and intra-scanner model, respectively p < 0.05), but not for distension (relative bias: 0.48% and −0.12% for inter- and intra-scanner model, respectively, p > 0.05). The biases estimated here cannot be generalized to any other pair of similar scanners. Therefore, longitudinal studies with large sample sizes switching between scanners should perform a preliminary comparison to evaluate potential biases between their devices. Furthermore, caution is warranted when using biases reported in similar comparative studies. Further work should evaluate the presence and relevance of similar biases in human data.

4 days in dry immersion increases arterial wall response to ultrasound wave as measured using radio-frequency signal, comparison with spaceflight data

Recent studies have reported a significant increase in common carotid artery (CCA) intima media thickness, wall stiffness and reflectivity to ultrasound, in astronauts, after six months of spaceflight. The hypothesis was that 4 days in dry immersion (subjects under bags of water) will be sufficient to change the CCA wall reflectivity to ultrasound similar to what observed after spaceflight. Such response would be quantified using the amplitude of the ultrasound signal returned to the probe by the target concerned. [coefficient of signal return (Rs)]. The Rs for anterior and posterior CCA wall, sternocleidomastoid muscle, intima layer and CCA lumen were calculated from the ultrasound radio frequency (RF) data displayed along each echographic line. After four days of DI, Rs increased in the CCA posterior wall (+15% +/- 10 from pre DI, p &lt; 0.05), while no significant change was observed in the other targets. The observed increase in Rs with DI was approximately half compared to what was observed after six months of space flight (+34% +/- 14). This difference may be explained by dose response (dry immersion only four days in duration). As a marker of tissue-level physical changes, Rs provide complimentary information alongside previously observed CCA wall thickness and stiffness.

Comparison between Carotid Distensibility-Based Vascular Age and Risk-Based Vascular Age in Middle-Aged Population Free of Cardiovascular Disease

The concept of vascular age (VA) was proposed to provide patients with an understandable explanation of cardiovascular (CV) risk and to improve the performance of prediction models. The present study compared risk-based VA derived from Framingham Risk Score (FRS) and Systematic Coronary Risk Estimation (SCORE) models with value-based VA derived from the measurement of the common carotid artery (CCA) distensibility coefficient (DC), and it assessed the impact of DC-based VA on risk reclassification. In 528 middle-aged individuals apparently free of CV disease, DC was measured by radiofrequency-based arterial wall tracking that was previously utilised to establish sex- and age-specific reference values in a healthy population. DC-based VA represented the median value (50th percentile) for given sex in the reference population. FRS-based and SCORE-based VA was calculated as recommended. We observed a good agreement between DC-based and FRS-based VA, with a mean difference of 0.46 ± 12.2 years (p = 0.29), while the mean difference between DC-based and SCORE-based VA was higher (3.07 ± 12.7 years, p < 0.0001). When only nondiabetic individuals free of antihypertensive therapy were considered (n = 341), the mean difference dropped to 0.70 ± 12.8 years (p = 0.24). Substitution of chronological age with DC-based VA in FRS and SCORE models led to a reclassification of 28% and 49% of individuals, respectively, to the higher risk category. Our data suggest that the SCORE prediction model, in which diabetes and antihypertensive treatment are not considered, should be used as a screening tool only in healthy individuals. The use of VA derived from CCA distensibility measurements could improve the performance of risk prediction models, even that of the FRS model, as it might integrate risk prediction with additional risk factors participating in vascular ageing, unique to each individual. Prospective studies are needed to validate the role of DC-based VA in risk prediction.

Single M-Line Is as Reliable as Multiple M-Line Ultrasound for Carotid Artery Screening

Purpose: Carotid artery properties can be evaluated with high accuracy and reproducibility using multiple M-line ultrasound. However, the cost of multiple M-line-based imaging modalities and the extensive operator expertise requirements hamper the large-scale application for arterial properties assessment, particularly in resource-constrained settings. This study is aimed to assess the performance of a single M-line approach as an affordable and easy-to-use alternative to multiple M-line imaging for screening purposes.

Methods: We used triplicate longitudinal common carotid artery (CCA) ultrasound recordings (17 M-lines covering about 16 mm, at 500 frames per second) of 500 subjects from The Maastricht Study to assess the validity and reproducibility of a single against multiple M-line approach. The multiple M-line measures were obtained by averaging over all available 17 lines, whereas the middle M-line was used as a proxy for the single M-line approach.

Results: Diameter, intima-media thickness (IMT), and Young's elastic modulus (YEM) were not significantly different between the single and multiple M-line approaches (p > 0.07). Distension and distensibility coefficient (DC) did differ significantly (p < 0.001), however, differences were technically irrelevant. Similarly, Bland-Altman analysis revealed good agreement between the two approaches. The single M-line approach, compared to multiple M-line, exhibited an acceptable reproducibility coefficient of variation (CV) for diameter (2.5 vs. 2.2%), IMT (11.9 vs. 7.9%), distension (10 vs. 9.4%), DC (10.9 vs. 10.2%), and YEM (26.5 vs. 20.5%). Furthermore, in our study population, both methods showed a similar capability to detect age-related differences in arterial stiffness.

Conclusion: Single M-line ultrasound appears to be a promising tool to estimate anatomical and functional CCA properties with very acceptable validity and reproducibility. Based on our results, we might infer that image-free, single M-line tools could be suited for screening and for performing population studies in low-resource settings worldwide. Whether the comparison between single and multiple M-line devices will yield similar findings requires further study.

Noninvasive carotid pressure-diameter loops to identify viscoelastic properties in ageing, hypertension and type 2 diabetes

OBJECTIVES

Arterial stiffness as pulse wave velocity (PWV) predicts cardiovascular events independently of blood pressure (BP). PWV does not distinguish between stiffness in systole and diastole. This cross-sectional study aimed to test the hypothesis that viscous and elastic carotid wall properties differ between systole and diastole, distinguishing effects of ageing, hypertension and T2 diabetes (T2DM).

METHODS

We examined carotid visco-elasticity in 307 people (180 men), with hypertension alone (n = 69), combined hypertension/T2DM (H-T2DM, n = 99), normotensive (N-T2DM, n = 25) and healthy controls (n = 114). Diameter (D)/pressure (P) waveforms were measured at right /left common carotid arteries, respectively. Local carotid PWV and distensibility in systole and diastole were evaluated by the D2P-loop method, and wall viscosity from hysteresis, the area (HA) within the P--D loop, as a dynamic measure of systolic loading and diastolic unloading.

RESULTS

Controls' hysteresis fell quadratically with age (R2 = 0.23, P < 0.001). Yet mean HA in hypertensive patients (0.95, 95% CI 0.65-1.23) was six-fold higher than in age-matched controls (0.14, -0.20 to 0.49, P < 0.001) with a 2.5× difference between diastolic (dDs) to systolic (sDs) distensibility (P < 0.05) in hypertensive patients. HA was higher in hypertensive patients and H-T2DMs (0.80, 0.58-1.04) than N-T2DMs (0.20, -0.17 to 0.54, P < 0.05), but similar between controls and N-T2DMs. BP-adjusted carotid diameters in all T2DM were significantly greater compared with controls and hypertensive patients.

CONCLUSION

Higher BP increased wall viscosity, hysteresis and relative difference between systolic and diastolic distensibility across groups. Carotid diameters were increased in all T2DMs, more in H-T2DM, probably altering BP-flow dynamics in T2DM.

Index of Reflectivity of Ultrasound Radio Frequency Signal from the Carotid Artery Wall Increases in Astronauts after a 6 mo Spaceflight

The objective was to quantify the index of reflectivity of the common carotid artery and surrounding structures, before and after 6 mo of microgravity. Our hypothesis was that structural changes in the insonated target would increase its index of reflectivity. The neck anterior muscle and common carotid artery (walls and lumen) were visualized by echography (17 MHz linear probe), and the radiofrequency signal along each vertical line was displayed. The limits of the radiofrequency data corresponding to each target (muscle, vessel wall) were determined from the B-mode image and radiofrequency trace. Each target's index of reflectivity was calculated as the proportion of backscattered energy to the whole backscattered energy along the line. After 6 mo in flight, the index of reflectivity increased significantly for both common carotid walls, while it remained unchanged for the neck muscle, carotid intima and lumen. The index of reflectivity provided additional information beyond traditional B-mode imaging.

Design of the Shunyi study on cardiovascular disease and age-related brain changes: a community-based, prospective, cohort study

Background

Rapid economic growth and increasing lifespan have contributed to an increasing burden of chronic non-communicable diseases in China. Population-based studies focusing on cardiovascular disease and age-related brain changes, with extensive clinical, genetic, and imaging data as well as a comprehensive evaluation of brain function are lacking in China. The Shunyi cohort study aimed to investigate the determinants and consequences of cardiovascular disease and age-related brain alterations among individuals residing in a rural area of Beijing.

Methods

This prospective, community-based study included individuals aged 35 years and older living in five villages in Shunyi, a rural district located 20 miles from urban Beijing. A total of 1,586 individuals were enrolled between June 2013 and September 2014. Biological samples and brain magnetic resonance images were collected along with baseline clinical data through face-to-face interviews. Whole exome sequencing and quantitative assessments of cognitive and motor function were performed.

Results

Among the 1,586 participants included, 40% were men, and the mean age of the cohort was 56.7±10.0 years. This population had a relatively low education level. A heavy burden of vascular risk factors with a low control rate was observed in the Shunyi population. Since 2017, the cohort has been followed up annually. As of October 2019, we had failed to obtain the follow-up data of five participants.

Conclusions

With an extensive range of clinical, genetic, and imaging data, the Shunyi cohort study has the potential to contribute significantly towards identifying the causes and consequences of cardiovascular disease and age-related brain changes in older people in China.

Automated measurement of compression-decompression in arterial diameter and wall thickness by image-free ultrasound

BACKGROUND AND OBJECTIVE

The manual measurement of arterial diameter and wall thickness using imaging modalities demand expertise, and the state-of-art automated or semi-automated measurement features are seldom available in the entry-level systems. The advanced ultrasound modalities are expensive, non-scalable, and less favorable for field and resource-constrained settings. In this work, we present a novel method to measure arterial diameter (D), surrogate intima-media thickness (sIMT), and with them their intra-cardiac cycle changes by employing an affordable image-free ultrasound technology.

METHODS

The functionality of the method was systematically validated on a simulation testbed, phantoms and, 40 human subjects. The accuracy, agreement, inter-beat, and inter-operator variabilities were quantified. The in-vivo measurement performance of the method was compared against two reference B-mode tools - Carotid Studio and CAROLAB.

RESULTS

Simulations revealed that for the A-mode frames with SNR > 10 dB, the proposed method identifies the desired arterial wall interfaces with an RMSE < 20 μm. The RMSE for the diameter and wall thickness measurements from the static phantom were 111 μm and 14 μm, and for the dynamic phantom were 117 μm and 18 μm, respectively. Strong agreement was seen between the in-vivo measurements of the proposed method and the two reference tools. The mean absolute errors against the two references and the inter-beat variability were smaller than 0.18 mm for D and smaller than 36 μm for sIMT measurements. Likewise, the respective inter-observer variabilities were 0.16 ± 0.23 mm and 43 ± 25 μm.

CONCLUSION

Acceptable accuracy and repeatability were observed during the validation, that were on a par with the recently reported B-mode techniques in the literature. The technology being real-time, automated, and relatively inexpensive, is promising for field and low-resource settings.

Measurement, Analysis and Interpretation of Pressure/Flow Waves in Blood Vessels

The optimal performance of the cardiovascular system, as well as the break-down of this performance with disease, both involve complex biomechanical interactions between the heart, conduit vascular networks and microvascular beds. ‘Wave analysis’ refers to a group of techniques that provide valuable insight into these interactions by scrutinizing the shape of blood pressure and flow/velocity waveforms. The aim of this review paper is to provide a comprehensive introduction to wave analysis, with a focus on key concepts and practical application rather than mathematical derivations. We begin with an overview of invasive and non-invasive measurement techniques that can be used to obtain the signals required for wave analysis. We then review the most widely used wave analysis techniques—pulse wave analysis, wave separation and wave intensity analysis—and associated methods for estimating local wave speed or characteristic impedance that are required for decomposing waveforms into forward and backward wave components. This is followed by a discussion of the biomechanical phenomena that generate waves and the processes that modulate wave amplitude, both of which are critical for interpreting measured wave patterns. Finally, we provide a brief update on several emerging techniques/concepts in the wave analysis field, namely wave potential and the reservoir-excess pressure approach.

Assessment of vascular stiffness using different modalities in patients with systemic lupus erythematosus: a case control study

Background

Cardiovascular disease is a major cause of morbidity and mortality in systemic lupus erythematosus (SLE) patients. Accurate risk stratification would require a simple, non-invasive index integrating all traditional and emerging risk factors. Vascular stiffness fulfills these requirements and has better predictive value for cardiovascular events than traditional risk factors in hypertensives and patients with coronary artery disease. Our aim was to determine whether arterial stiffness is increased in SLE patients compared to healthy controls and to correlate the arterial stiffness in SLE patients with cardiovascular risk factors, namely, hypertension and diabetes mellitus.

Results

This study included 50 SLE patients and 50 age- and gender-matched healthy individuals. SLE patients had higher median aortic stiffness index (SI) and lower strain and distensibility, compared to controls (p value for all < 0.001). SLE patients had significantly impaired flow-mediated dilation (FMD) compared to controls: the median (range) in SLE patients was 8.82 (2.5–21.87), compared to 19 (12–37.5) in controls (z = − 7.695, p ˂ 0.001). Regarding quality arterial stiffness (QAS) parameters, SLE patients had significantly lower median carotid distension, distensibility coefficient, and compliance coefficient, with higher median carotid SI, carotid pulse wave velocity (PWV), and augmentation index (AI), compared to controls (p value for all ≤ 0.001). SLE patients had a higher median cf-PWV 6.5 m/s (4.8–11.8), compared to a median of 4.6 m/s (3.8–6.9) in controls (z = − 8.193, p ˂ 0.001). Linear regression analysis to adjust for hypertension and diabetes mellitus yielded a statistically significant difference between both groups for all of the above parameters (p = 0.014 for maximum carotid intima media thickness (IMT) and < 0.001 for remaining parameters), with the exception of the maximum carotid augmentation index (p = 0.184).

Conclusion

SLE patients have significantly increased arterial stiffness and impaired FMD compared to healthy controls. This is true even after adjusting for hypertension and diabetes mellitus, highlighting the fact that SLE could be an independent cardiovascular risk factor. These findings emphasize the need for early management of SLE together with aggressive risk factor modification.

Carotid atherosclerosis, dilation, and stiffness relate to cerebral small vessel disease

OBJECTIVE

To investigate the association of carotid atherosclerosis, dilation, and stiffness with imaging markers of cerebral small vessel disease (CSVD) in a community-based sample.

METHODS

The study comprised 1,051 participants (age 57.5 ± 9.2 years). Carotid plaques, intima-media thickness (IMT), diastolic diameter, pulse wave velocity, and stiffness index (β) were measured by ultrasound. Imaging markers of CSVD, including lacunes, cerebral microbleeds, dilated PVS, and white matter hyperintensities (WMH) volume, were assessed.

RESULTS

Carotid plaque was associated with the presence of lacunes (odds ratio [OR] 2.78, 95% confidence interval [CI] 1.78-4.33; p < 0.001) and larger WMH volume (natural log transformed, β ± SE, 0.32 ± 0.10; p = 0.002). The increased carotid diameter was associated with the presence of lacunes (OR 1.82, 95% CI 1.22-2.72; p = 0.003), larger WMH volume (β ± SE, 0.37 ± 0.10; p < 0.001), and PVS in the basal ganglia (OR 1.59, 95% CI 1.20-2.11; p = 0.001). Associations of carotid dilation and CSVD were independent of carotid IMT and plaque. Most parenchymal lesions were located in the basal ganglia and deep white matter. Carotid IMT and stiffness were not associated with CSVD.

CONCLUSIONS

Carotid atherosclerosis and dilation are associated with imaging markers of CSVD. The noninvasive carotid assessment would seem to be a rational approach to risk stratification of CSVD.

Radiofrequency-based wall tracking for noninvasive assessment of local carotid pulse pressure: comparison with applanation tonometry and association with organ damage

OBJECTIVES

Central pulse pressure (PP) has been suggested a better predictor of cardiovascular risk than brachial PP, and its routine noninvasive assessment can be useful for risk stratification. The present study evaluated the capability of a radiofrequency-based carotid wall tracking to estimate central PP from distension curves, comparing the values of carotid PP as obtained by wall tracking with those provided by applanation tonometry. Furthermore, the associations of carotid PP with intermediate markers of cardiovascular risk, like carotid intima-media thickness (IMT) and left ventricular mass (LVM), were assessed.

METHODS

Carotid PP was measured by wall tracking and applanation tonometry during the same session in 346 individuals (healthy controls, patients with hypertension and diabetes). IMT was measured in all individuals and LVM was measured in 253.

RESULTS

Carotid PP values as measured by wall tracking and applanation tonometry were highly correlated [r = 0.87; slope 0.90 (0.85-0.95); P < 0.0001; mean difference = 3.1 ± 6.8 mmHg], and were independently determined by the same variables (age, heart rate, triglycerides, blood pressure-lowering therapy). Carotid IMT and LVM correlated more strongly with carotid PP (r = 0.44 and 0.50; P < 0.0001 for both) than with brachial PP (r = 0.34 and 0.42; P < 0.0001 for both). Patients with carotid PP at least 50 mmHg had higher IMT, LVM, and prevalence of LV hypertrophy than those with PP less than 50 mmHg (P = 0.0001 to <0.0001).

CONCLUSIONS

Local carotid PP as estimated by wall tracking is comparable to that obtained by applanation tonometry, and it shows a better association with target organ damage than brachial blood pressure. Assessment of carotid PP during routine ultrasound examination of extracranial carotid tree may provide additional information for individual risk stratification.

Age-specific reference values for carotid arterial stiffness estimated by ultrasonic wall tracking

Interaction between arterial stiffness and hypertension plays an important role in the development of cardiovascular disease. Accordingly, assessment of arterial stiffness may provide a tool for estimating cardiovascular risk and monitoring therapy in hypertensive patients. Radiofrequency-based vascular ultrasound allows accurate noninvasive assessment of local mechanical properties of large arteries, but for its use in clinical practice, reference values according to age and sex are mandatory for each vascular site. To provide reference values for common carotid artery stiffness as assessed by an echo-tracking imaging system Hitachi-Aloka, we pooled measurements collected in 1847 healthy subjects aged 3–74 years (1008 males and 839 females) recruited in 14 European centers in the E-tracking International Collaboration (ETIC). Statistical models were developed to describe relationships of different stiffness indices with age and to calculate median values and Z-scores corresponding to ± 1 and ± 2 standard deviations. In our apparently healthy population, age accounted for 53% of variability in the elastic modulus (epsilon), 39% in arterial compliance, 47% in stiffness index (β), and 56% in local pulse wave velocity; on average, blood pressure accounted for a further 7.5% of variability. Dependence on age was not linear; changes in mean values increased at older ages, especially for epsilon and β. There was an interaction between age and gender for arterial compliance, which was higher in males. We present nomograms and a software that can be used for the automated calculation of Z-scores for local carotid stiffness in individual patients. These tools can be used to establish prognostic indicators or surrogate targets for treatment monitoring.

Familial history of hypertension as a predictor of increased arterial stiffness in normotensive offspring

Background

Increased arterial stiffness can be used as a prognostic marker of arterial hypertension. The relationship between arterial stiffness and arterial hypertension seems to be reciprocal.

Objective

Evaluation of changes of the arterial elastic prosperities in normotensive subjects, with and without parental history of hypertension.

Subjects and Methods

One hundred and ten normotensive individuals, aged 20–30 years, were divided into two groups: group-A (n = 57) and group-B (n = 53) subjects with positive and negative parental history of hypertension, respectively. Systolic, diastolic and pulse pressures were measured using mercury sphygmomanometer. The elastic properties of the ascending aorta and the common carotid arteries were assessed using M-mode echo and B-mode imaging, respectively. Stiffness index of the digital volume pulse (SIDVP) was measured in the right index finger using photoplethysmography.

Results

Group A subjects showed higher aortic stiffness index (p = 0.002), carotid stiffness index (p = 0.001), carotid pulse wave velocity (p ⩽ 0.001) and stiffness index of digital volume pulse (p = 0.001). Group A subjects showed lower aortic distensibility (p = 0.001), aortic strain (p = 0.004), changes in aortic diameter (p = 0.022), carotid distension (p = 0.026), carotid distensibility coefficient (p ⩽ 0.001) and carotid compliance coefficient (p = 0.002).

Conclusion

The aortic and carotid stiffness parameters and SIDVP were higher in normotensive offspring of hypertensive parents. This finding could direct the attention towards the increased cardiovascular risk in this group and thus prompt earlier and tighter prevention of cardiovascular risk factors.

Impact of glycemic control on aortic stiffness, left ventricular mass and diastolic longitudinal function in type 2 diabetes mellitus

BACKGROUND

Poor glycemic control is associated with impaired left ventricular (LV) diastolic function in patients with type 2 diabetes mellitus (T2DM). Inappropriate LV mass increase and accelerated aortic stiffening were suggested to participate on deterioration of diastolic function. The present study investigated the inter-relationships between glycemic control, early diastolic and systolic longitudinal velocity of mitral annulus, LV mass and aortic stiffness in T2DM patients free of cardiovascular disease and with preserved LV ejection fraction, and compared them with those observed in healthy volunteers of similar age and sex distribution.

METHODS

125 T2DM patients and 101 healthy volunteers underwent noninvasive measurement of systolic (s') and early diastolic (e') velocities of mitral annulus, LV mass, carotid-femoral pulse wave velocity (cfPWV) and local carotid blood pressure (BP).

RESULTS

Forty-four (35.2%) T2DM patients had e' velocity lower than that expected for age (against 7.9% in healthy volunteers; P < 0.0001), 34 (27.2%) had cfPWV higher than that expected for age and mean BP (against 5.9% in healthy volunteers; P < 0.0001), and 71 (56.8%) had LV mass higher than that expected for body size and stroke work (against 17.6% in healthy volunteers; P < 0.0001). Carotid systolic BP was higher in T2DM patients (124 ± 14 vs 111 ± 11 mmHg; P < 0.0001). In multivariate analysis, e' velocity was independently related to age, carotid BP and s' velocity in healthy volunteers, and to male sex, age, carotid BP, heart rate and LV mass in T2DM. Glycosylated hemoglobin (HbA1c) was independently related to cfPWV and LV mass in T2DM patients. T2DM patients with HbA1c ≥6.5% (N = 85) had higher cfPWV (P < 0.05), central BP (P = 0.01), prevalence of LV hypertrophy (P = 0.01) and lower e' and s' velocity (P = 0.001 and <0.05, respectively) as compared to those with HbA1c <6.5%.

CONCLUSIONS

One-third of T2DM patients with preserved LV ejection fraction has sign of subclinical LV diastolic dysfunction. HbA1c levels are positively associated with LV mass and aortic stiffness, both of which show a negative independent impact on early diastolic velocity e', the latter through an increase in afterload. T2DM patients with suboptimal glycemic control (HbA1c ≥ 6.5%) have lower diastolic and systolic LV longitudinal performance, together with increased aortic stiffness and a higher prevalence of LV hypertrophy.

Carotid-Femoral Pulse Wave Velocity Assessed by Ultrasound: A Study with Echotracking Technology

Described here is a new method for determination of carotid-femoral pulse wave velocity (PWV) based on arterial diameter waveform recording by an ultrasound system. The study was carried out on 120 consecutive patients. Carotid-femoral PWV was determined using a tonometric technique (PWVpp, PulsePen, DiaTecne, Milan, Italy) and an echotracking ultrasound system (PWVet, E-Track, Aloka, Tokyo, Japan). The relationship between PWVpp and PWVet was evaluated by linear regression and Bland-Altman analysis. There was excellent agreement between PWVet and PWVpp (Pearson's r = 0.94, 95% confidence interval: 0.91-0.96, p < 0.0001; PWVet = 0.88 × PWVpp + 0.57). The Bland-Altman plot revealed an offset of -0.33 m/s with limits of agreement from -2.21 to 1.54 m/s. The coefficients of variation for within-subject repeatability between PWVet and PWVpp had were 5.79% and 8.47%, respectively, without significant differences in the Bland-Altman analysis. The results suggest that echotracking technology can provide a reliable estimate of aortic stiffness comparable to that of the tonometric techniques.

Associations between common carotid artery diameter, Framingham risk score and cardiovascular events

BACKGROUND AND AIMS

Vascular biomarkers are associated with risk burden and are capable to predict the development of future cardiovascular (CV) events; yet, their additive predictive value over and above established risk algorithms seems to be only modest. The present study evaluated the cross-sectional associations between vascular biomarkers, 10-year Framingham risk (FR) and prevalent CV events in a population with a high prevalence of hypertension and diabetes.

METHODS AND RESULTS

As many as 681 subjects (419 men, age = 60 ± 10 years, 282 diabetics, 335 hypertensives, mean FR score = 22.5 ± 16.5%) underwent an integrated vascular examination including: radiofrequency-based ultrasound of common carotid artery (cca) to measure intima-media thickness (IMT), inter-adventitial diameter (IAD) and local pulse wave velocity (PWV); applanation tonometry to assess carotid pulse pressure (PP) and augmentation index (AIx); carotid-femoral PWV (cfPWV) measurement. One hundred and thirty-five subjects (19.8%) had history of CV events, and CV events were independently associated with male sex, age, antihypertensive treatment, current smoking, HDL-cholesterol and ccaIAD. In logistic regression model, only ccaIAD was associated with prevalence of CV events after adjustment for FR score, with the OR of 1.71 [1.34-2.19] (P < 0.0001) that remained unchanged when ccaIMT was included into the model (OR = 1.76 [1.36-2.27]; P < 0.0001). The association between prevalent CV events and ccaIAD was significant (OR of 1.65 [1.24-2.20]; P = 0.0005) also in a subgroup of subjects being at a high 10-year risk of CV disease (N = 330).

CONCLUSIONS

In a population with a high prevalence of diabetes and hypertension, ccaIAD was the only vascular measure associated with prevalent CV events, independently of FR score.

The impact of age and risk factors on carotid and carotid-femoral pulse wave velocity

OBJECTIVE

Segmental carotid-femoral pulse-wave velocity (PWV) is a gold standard method for arterial stiffness assessment; recently, a local carotid PWV measurement by ultrasound has been developed. The present study compared the impact of age and established risk factors on carotid and carotid-femoral PWV.

METHODS

Three hundred and seven volunteers (167 men; age from 15 to 78 years) free of cardiovascular disease, diabetes, antihypertensive and lipid-lowering treatment underwent sequential measurement of carotid and carotid-femoral PWV.

RESULTS

In the entire study population, both carotid and carotid-femoral PWV were independently associated mainly with age and blood pressure. In individuals more than 50 years old (N = 132, 80 men), carotid-femoral PWV, but not carotid PWV, was also associated with high-density lipoprotein (HDL)-cholesterol and fasting glucose. The annual increase in carotid and carotid-femoral PWV was similar (0.087 ± 0.004 and 0.090 ± 0.005  m/s, respectively; P = 0.69). Carotid PWV increased with age more rapidly in women than in men (0.099 ± 0.005 vs. 0.076 ± 0.005  m/s per year, P < 0.005), whereas carotid-femoral PWV showed a steeper increase in individuals more than 50 years old than individuals aged 50 years or less (0.150 ± 0.019 vs. 0.088 ± 0.007  m/s per year, P = 0.001).

CONCLUSION

In apparently healthy population, both carotid and carotid-femoral PWV were influenced above all by age and blood pressure. Other established cardiovascular risk factors had a limited impact only on carotid-femoral PWV of older individuals. The age-related increase in carotid and carotid-femoral PWV seemed to follow different patterns; increase in carotid PWV showed age-sex interaction, being steeper in women, whereas increase in carotid-femoral PWV was more prominent in older individuals.

Hemodynamic overload and intra-abdominal adiposity in obese children: Relationships with cardiovascular structure and function

BACKGROUND AND AIMS

Childhood obesity promotes adverse changes in cardiovascular structure and function. This study evaluated whether these changes are related to intra-abdominal adiposity and associated cardiometabolic risk or to body-size induced hemodynamic overload.

METHODS AND RESULTS

55 obese children/adolescents and 35 healthy-weight controls underwent carotid, cardiac and abdominal ultrasound to assess carotid artery intima-media thickness (IMT), diameter, distension and stiffness, left ventricular (LV) dimension, mass and function and extent of intra-abdominal adiposity. As compared to controls with healthy BMI, obese children had higher systolic blood pressure (BP), stroke volume and lower total peripheral resistance (P < 0.001-0.0001), higher plasma triglycerides, glycated hemoglobin, insulin and HOMA-IR index (P = 0.01-<0.0001), higher carotid IMT, diameter and distension (P < 0.005-0.0005), higher LV diameter, wall thickness and mass (P < 0.001-0.0001), and impaired LV diastolic function assessed by myocardial longitudinal performance (P < 0.005). In entire population, independent determinants of carotid diameter, LV diameter, wall thickness and mass were fat-free mass (or stroke volume, respectively) and BP. Carotid distension was determined by carotid diameter and BP, and carotid IMT by carotid diameter, BP, HDL-cholesterol and glycated hemoglobin. LV diastolic performance was inversely related to preperitoneal fat thickness and plasma insulin levels.

CONCLUSIONS

Obese youths present signs of impaired lipid and glucose metabolism, hyperdynamic circulation and cardiovascular changes. Increase in LV dimensions and mass and in carotid diameter and distension seems to reflect adaptation to body-size induced increase in hemodynamic load, changes in LV diastolic performance a negative impact of intra-abdominal adiposity and associated metabolic risk, and increase in IMT both adaptive remodeling and metabolic risk.

Structural and Functional Abnormalities of Carotid Artery and Their Relation with EVA Phenomenon

Early vascular aging is a process characterized by a reduction in arterial elastin with an increase in collagen that has been related to cardiovascular risk factor and can determine an increased arterial stiffness and central blood pressure. It can be measured by several non invasive methods and in different arterial segment. The present paper will focus on functional (local stiffness parameter) and structural (intima media thickness) carotid arteries alterations typically evaluated by ultrasound methods. Methodological, research and clinical issue has been reviewed.