Carotid Pressure Research Articles

Wave reflections, arterial stiffness, and orthostatic hypotension.

The effect of wave reflections on blood pressure change associated with posture remains unclear. We therefore applied a wave separation technique to investigate the relations of the backward pressure wave amplitude with orthostatic pressure changes and orthostatic hypotension (OH). We analyzed data from 613 subjects who had participated in our hemodynamic studies. Measurements of brachial systolic (SBP) and diastolic blood pressures (DBP), carotid-femoral pulse wave velocity (cf-PWV), and backward pressure wave amplitude from a decomposed carotid pressure wave (Pb) were obtained at supine position. SBP and DBP were measured again 3 minutes after standing. OH was defined as a fall of ≥20 mm Hg in SBP and/or ≥10 mm Hg in DBP. Subjects with OH (n = 100) were characterized with significantly higher supine SBP and DBP and significantly lower standing SBP and DBP when compared with subjects without OH. Subjects with OH were also characterized with significantly higher cf-PWV and Pb. cf-PWV and Pb separately were significantly associated with the orthostatic SBP change in univariable and multivariable analyses. Also, cf-PWV and Pb separately were significant predictors of OH in univariable and multivariable analyses. cf-PWV predicted OH in the younger but less so in the older subgroup, whereas Pb demonstrated similar prediction in both subgroups. In a final multivariable model, both cf-PWV and Pb were significant independent predictors of OH. Wave reflections are an independent determinant of orthostatic SBP change and OH in both younger and older subjects.

Physical Activity is Associated with Attenuated Carotid Blood Pressure Response to Mental Stress

Physical Activity is Associated with Attenuated Carotid Blood Pressure Response to Mental Stress

Determination of delay time in individual transfer function for central aortic pressure reconstruction.

In previous research, time-delay (Δt) was a more important parameter than the reflection coefficient in the individual transfer function of central aortic pressure reconstruction. The Δt can be obtained by electrocardiography (ECG) or phonocardiography (PCG). Because the pre-ejection period remains an uncertain factor, the present study used ECG and PCG to define the delay time and analyzed the accuracy of the reconstruction results. The Δt pre is the actual delay time derived from the aorta to the carotid pressure wave, Δt PCG is the time delay between the aortic valve component of the second heart sound and the dicrotic incisura of the carotid pressure wave, and Δt ECG represents the delay from the interval of the ECG R-peak to the foot of the carotid pressure wave. Compared with the measured aortic pressure, the reconstruction result obtained by Δt=Δt PCG slightly differed from the best result estimated by Δt=Δt pre. However, the differences between the result obtained by Δt=Δt ECG and the best result were significant in terms of the diastolic blood pressure, and pulse pressure, and especially in terms of the augmentation index and root-mean-square-error. Thus, the Δt should be determined by PCG for central aortic pressure reconstruction in practice.

Comparison of two techniques for measuring pulse wave velocity in children (1156.5)

Pulse wave velocity (PWV) is used as an indicator of arterial stiffness. Carotid‐femoral PWV is the gold standard method. However, femoral pressure is difficult to measure in children and therefore carotid‐toe PWV has been used as an alternate method. Furthermore, measurement of carotid artery pressure requires highly skilled technicians, while participants are required to remain still over a time period, making this measure difficult to obtain in children. As a result, this study was undertaken to determine the effectiveness of using ECG R‐wave‐toe as an alternate method to measure PWV. Carotid‐toe PWV and R‐wave‐toe PWV were calculated for 31 healthy adolescents (16 females). Ten consecutive beats were averaged for each subject to determine the pulse transit time for each PWV method. PWV was calculated by dividing the pulse transit time by the distance travelled between the two recording sites for each method. A paired t‐test and Pearson correlation were conducted and significance was set at p<0.05. PWV estimated by the R‐wave‐toe technique was significantly lower than that estimated by the carotid‐toe technique (3.86 vs. 4.50 m/s, p<0.001). As well, a positive correlation was found between the two methods (r = 0.86, R2 = 0.75, p<0.001). Although based on a small sample, these results suggest that R‐wave‐toe measurement technique may be a simple and useful alternate method to obtain PWV in children.Grant Funding Source: Supported by Canadian Institutes of Health Research

MR and applanation tonometry derived aortic impedance: Association with aging and left ventricular remodeling

We sought to noninvasively estimate aortic impedance indices from MR and tonometric data. MR aortic velocity-encoded and carotid applanation tonometry pressure data of 70 healthy subjects (19-79 years) were used to calculate the following indices from impedance spectrum: (i) characteristic impedance (Zc) reflecting pulsatile component of left ventricular (LV) afterload, (ii) frequency of the minimal impedance magnitude related to arterial compliance (FMIN ), (iii) total peripheral resistance (TPR) related to steady LV load, (iv) impedance oscillatory index (ZINDEX ) related to proximal reflections, and (v) reflection magnitude (RM). Associations with age and LV remodeling (LV mass/end-diastolic volume) were investigated using multivariate analysis. All indices except Zc were associated with age independent of subjects characteristics and systolic blood pressures. They were all significantly associated with the well-established carotid-femoral pulse wave velocity (r ≥ 0.29; P < 0.01). However, such associations were not independent of age. Pulsatile index Zc was independently associated with carotid pulse pressure (r = 0.53, P < 0.001). Moreover, conversely to conventional stiffness indices, Zc and TPR were independently associated with LV remodeling (r = 0.30, r = 0.43, respectively, P < 0.01). We estimated aortic impedance from velocity-encoded MR and tonometry data resulting in reliable impedance and reflection indices as confirmed by their significant and independent associations with age and LV remodeling.

Role of nitrite in regulation of fetal cephalic circulation in sheep

Nitrite has been postulated to provide a reservoir for conversion to nitric oxide (NO), especially in tissues with reduced oxygen levels as in the fetus. Nitrite would thus provide local vasodilatation and restore a balance between oxygen supply and need, a putative mechanism of importance especially in the brain. The current experiments test the hypothesis that exogenous nitrite acts as a vasodilator in the cephalic vasculature of the intact, near term fetal sheep. Fetuses were first instrumented to measure arterial blood pressure and carotid artery blood flow and then studied 4-5 days later while in utero without anaesthesia. Initially l-nitro-arginine (LNNA) was given to block endogenous NO production. Carotid resistance to flow increased 2-fold from 0.54 ± 0.01 (SEM) to 1.20 ± 0.08 mmHg min ml(-1) (in 13 fetuses, P < 0.001), indicating NO tonically reduces cerebral vascular tone. Sodium nitrite (or saline as control) was then infused in increasing step-doses from 0.01 to 33 μm in half-log increments over a period of 2 h. Carotid artery pressure, blood flow and vascular resistance did not change compared to fetuses receiving saline, even at plasma nitrite concentrations two orders of magnitude above the physiological range. The results indicate that while cephalic vascular tone is controlled by endogenous nitric oxide synthase activity, exogenously administered nitrite is not a vasodilator at physiological concentrations in the vasculature served by the carotid artery of fetal sheep.

O158 Wave reflection from aortic coarctation augments carotid pressure: Insights from a computer model and wave intensity analysis

O158 Wave reflection from aortic coarctation augments carotid pressure: Insights from a computer model and wave intensity analysis

Gaussian fitting for carotid and radial artery pressure waveforms: comparison between normal subjects and heart failure patients

It has been reported that Gaussian functions could accurately and reliably model both carotid and radial artery pressure waveforms (CAPW and RAPW). However, the physiological relevance of the characteristic features from the modeled Gaussian functions has been little investigated. This study thus aimed to determine characteristic features from the Gaussian functions and to make comparisons of them between normal subjects and heart failure patients. Fifty-six normal subjects and 51 patients with heart failure were studied with the CAPW and RAPW signals recorded simultaneously. The two signals were normalized first and then modeled by three positive Gaussian functions, with their peak amplitude, peak time, and half-width determined. Comparisons of these features were finally made between the two groups. Results indicated that the peak amplitude of the first Gaussian curve was significantly decreased in heart failure patients compared with normal subjects (P<0.001). Significantly increased peak amplitude of the second Gaussian curves (P<0.001) and significantly shortened peak times of the second and third Gaussian curves (both P<0.001) were also presented in heart failure patients. These results were true for both CAPW and RAPW signals, indicating the clinical significance of the Gaussian modeling, which should provide essential tools for further understanding the underlying physiological mechanisms of the artery pressure waveform.

Early corrective surgery may prevent Baroreflex impairment in congenital heart diseases

Arrhythmias in tetralogy of Fallot (ToF) and transposition of the great arteries (TGA) could be the consequence of reduced baroreflex-sensitivity (BRS). Hypoxia until the first surgical correction in these patients may impair BRS. We aimed to compare the BRS of ToF, TGA and control subjects and test the effect of the timing of operation on BRS. 19 patients with ToF, 22 patients with TGA and 19 healthy controls were enrolled. Carotid pulse pressure (PPc) was similar in ToF and TGA patients but lower in controls. BRS was lower in the ToF group compared to the control or to the TGA groups. The first operation was performed later in patients with ToF than in patients with TGA. Adjustment for PPc attenuated the difference in BRS between ToF and control subjects. Adjustment for age at corrective surgery abolished the difference in BRS between the ToF and the TGA groups. In ToF patients, reduced BRS could be explained by the stiffening of central arteries and the later corrective surgery. Earlier surgical correction may prevent irreversible deterioration of baroreflex-function and arrhythmia development in ToF patients.

Nonphysiologic blood flow triggers endothelial and arterial remodeling in vivo: Implications for novel left ventricular assist devices with a peripheral anastomosis

Less invasive circulatory support devices have been developed that require anastomosis to a peripheral artery. The Symphony Heart Assist System (Abiomed, Inc, Danvers, Mass) is a volume-displacement pump sewn to the subclavian artery to provide partial circulatory support. The surgical configuration produces nonphysiologic blood pressure and bidirectional flow in the subclavian artery. Our objective was to identify effects of altered hemodynamics on arterial structure and function. In calves (n=23; 80-100 kg), the Symphony pump was sewn end-to-side to the carotid artery. Acutely, carotid blood pressure and flow were recorded to evaluate hemodynamic changes. After medium-term support (1-4 weeks), carotid artery was studied. Histologic and molecular assays evaluated architectural changes. Quantitative real-time polymerase chain reaction evaluated gene expression of matrix metalloproteinase (MMP)-2, MMP-9, and connective tissue growth factor. Invitro carotid arterial-ring studies evaluated physiologic responses. During Symphony support, carotid arterial pressure was 200/15 mm Hg. Antegrade flow increased significantly (P<.05) from 1.40 ± 0.32 to 4.29 ± 0.33 L/min. Flow during native cardiac diastole reversed completely from 0.25 ± 0.05 to -4.15 ± 0.38 L/min in carotid artery proximal to the anastomosis. After medium-term support, the carotid artery was significantly dilated with significantly thinner tunica media and thicker tunica adventitia than in control carotid arteries. MMP-9 gene expression decreased significantly, connective tissue growth factor gene expression increased significantly, and collagen, elastin, and total extracellular matrix increased significantly. Endothelial cells were significantly hypertrophied and produced significantly more von Willebrand factor. Endothelial apoptosis increased significantly. Platelet-endothelial interactions decreased significantly. Endothelial-independent contraction decreased significantly, whereas endothelial-dependent relaxation increased modestly. Assisted circulation with a left ventricular assist device triggered arterial remodeling that allowed a peripheral artery to accommodate the altered hemodynamics of a novel partial-support pump. Further delineation of remodeling pathways may be of significance for the emerging field of partial circulatory support.

Effects of two weeks of metformin treatment on whole-body glycocalyx barrier properties in db/db mice

BackgroundThe anti-diabetic drug metformin has been demonstrated to exert a protective effect against vascular complications in diabetes independent of its glucose lowering action. Since the endothelial glycocalyx has been indicated to have important vasculoprotective properties and to be vulnerable to degradation by hyperglycemic conditions, we evaluated in the current study the effect of short-term metformin treatment on whole-body glycocalyx barrier properties in a mouse model of non-insulin dependent diabetes mellitus (db/db mouse).MethodsGlycocalyx barrier properties were measured in an acute experiment in three groups of mice: 1) db/db mice without treatment serving as controls, 2) db/db mice which received metformin for two weeks in the drinking water serving as experimental group, and 3) C57Bl/6 mice serving as reference group. Animals were put under anesthesia (ketamine, medetomidine, and atropine) and carotid artery blood pressure was continuously monitored. To probe the glycocalyx a mixture of the tracers FITC-labeled 70 kDa dextrans (Dex70) or fluorescein-labeled red blood cells (RBCs) versus Texas Red-labeled 40 kDa dextrans (Dex40) was infused and blood samples subsequently collected for 30 min to determine the initial vascular distribution volume and clearance of these tracers. Urine was collected and dry-to-wet weight of heart and kidney were determined after the experiment. Group differences were tested using unpaired t-tests.ResultsMetformin treatment did not affect body weight, fasting blood glucose and arterial blood pressure. Compared to C57Bl/6 mice, db/db mice showed a diminished initial exclusion and increased vascular clearance of Dex70 versus Dex40 (P < 0.05), and both were improved by the metformin treatment (P < 0.05). While urine production was higher in the db/db mice compared to C57Bl/6 (P < 0.05), heart and kidney of the metformin treated animals showed comparable dry-to-wet weights compared to the C57Bl/6 mice.ConclusionsTwo weeks of metformin in the drinking water is associated with an improvement in glycocalyx barrier properties in db/db mice, as evidence by an enhanced exclusion and retention of 70 kDa dextrans in the vasculature. In addition, metformin improved hydration of heart and kidney. Previous reported cardiovascular benefits of metformin may well involve an improvement of the endothelial glycocalyx.

Singular and combined effects of nebivolol and lifestyle modification on large artery stiffness in hypertensive adults

We hypothesized that the combination of nebivolol and lifestyle modification would reduce large artery stiffness in middle-aged and older hypertensive adults more than either intervention alone. To address this, 45 men and women (age 40-75 years) with stage I hypertension were randomized to receive either nebivolol (NB; forced titration to 10 mg OD; n = 15; age 57.2 ± 11.4 years; body mass index [BMI] 30.8 ± 5.8 kg/m(2)), lifestyle modification (LM; 5-10% weight loss via calorie restriction and physical activity; n = 15; age 52.7 ± 8.5 years; BMI 33.9 ± 7.2 kg/m(2)) or nebivolol plus lifestyle modification (NBLM; n = 15; age 58.9 ± 9.4 years; BMI 32.5 ± 4.9 kg/m(2)) for 12 weeks. β-stiffness index, a blood-pressure-independent measure of arterial stiffness, and arterial compliance were measured via high-resolution ultrasound and tonometry at baseline and after the 12-week intervention. There was no difference between groups in age, body weight or composition, blood pressure, or in β-stiffness index or arterial compliance at baseline (all p > 0.05). Following the 12-week intervention, body weight decreased ~5% (p < 0.05) in the LM and NBLM groups but did not change from baseline in the NB group (p > 0.05). Supine brachial and carotid systolic and diastolic blood pressure declined following treatment in each of the groups (p < 0.05). However, the magnitude of reduction was not different (p < 0.05) between groups. β-stiffness index declined (-2.03 ± 0.60, -1.87 ± 0.83 and -2.51 ± 0.90 U) and arterial compliance increased similarly (both p > 0.05) in the NB, LM and NBLM groups, respectively. In summary, our findings indicate that the combination of nebivolol and lifestyle modification reduced large artery stiffness to a similar degree as either intervention alone in middle-aged and older hypertensive adults.

Descending aorta subject-specific one-dimensional model validated against in vivo data

The aorta plays a major role in the cardiovascular system and its function and structure are primarily affected by aging, eating habits, life style and other cardiovascular risk factors, inducing increased stiffness which is associated with cardiovascular and cerebral morbi-mortality. Our objective was to develop and validate a robust subject-specific one-dimensional wave propagation numerical model of the descending aorta. This model with a cross-sectional area, velocity and pressure formulation is built using geometric and hemodynamic data measured on a specific person and is validated against in vivo data acquired on the same subject at three distinct anatomical locations along the thoracic aorta. We studied seven healthy volunteers, who underwent carotid applanation tonometry and aortic cardiovascular magnetic resonance (CMR). Responses of our model in terms of changes in central pressure waveform with arterial alterations were consistent with previously described physiological knowledge. Quantitative validation averaged over the three descending aortic locations and the seven subjects provided low rms errors (given in percentage of the maximal clinical value) between simulated and CMR data, i.e. area: 10±6%, velocity: 11±3%, flow rate: 9±3%. Finally, we also found low rms (5±2%) when comparing simulated pressure in the proximal aortic location against tonometric carotid pressure curves. In conclusion, this simple model performs similar to more complex models of the entire systemic arterial tree at a fraction of the cost, and could be of major usefulness in the non-invasive and local estimation of proximal biomechanical and hemodynamic indices.

Arterial compliance and stiffness following low-intensity resistance exercise

Although acute high-intensity resistance exercise to exhaustion decreases arterial compliance and increases arterial stiffness, the effect of low-intensity resistance exercise (LRE) to exhaustion on arterial compliance and stiffness remains unknown. The present study investigated the acute effects of LRE on arterial compliance and stiffness. Ten healthy individuals (age 26 ± 5 years) performed LRE (40% of 1 repetition maximum) and control (CON: seated rest in the exercise room) trials on separate days in a randomized controlled crossover fashion. The LRE comprised three sets of bench presses to exhaustion with an inter-set rest period of 2 min. In the CON trial, LRE was not performed. Carotid arterial compliance, the β-stiffness index (via simultaneous B-mode ultrasound and applanation tonometry), carotid and brachial blood pressure and heart rate were measured before and at 30 and 60 min after both trials. Carotid arterial compliance and the β-stiffness index significantly increased and decreased, respectively (both P < 0.05), at 30 and 60 min after the LRE trials, but neither significantly differed after the CON trials. Carotid and brachial blood pressure and heart rate did not change at 30 and 60 min after both trials from baseline. These results suggest that LRE acutely increases arterial compliance and decreases arterial stiffness.

Carotid arterial intima–media thickness and arterial stiffness in pre‐eclampsia: analysis with a radiofrequency ultrasound technique

Whether arterial elasticity is reduced in preeclampsia has been investigated only rarely. This study aimed to characterize in vivo the carotid arterial intima–media thickness (IMT) and mechanical properties in women with pre-eclampsia by employing a radiofrequency ultrasound technique. We included 22 late-onset pre-eclamptic pregnant women and 28 normotensive pregnant women who were matched for age (29 ± 6 vs. 27 ± 3, P=0.09) and gestational age (36.0 ± 3.2 vs. 35.8 ± 2.4 weeks, P=0.802). All women were nulliparous with singleton pregnancy. The pre-eclamptic women had a significantly higher arterial pressure than did the normotensive women (P<0.0001). All women underwent right common carotid arterial measurements with an ultrasound machine equipped with automatic Quality IMT (QIMT) and Quality Arterial Stiffness (QAS) capability. At follow-up examination 18 months after parturition, measurements were repeated in 10 of the pre-eclamptic women and 11 of the normotensive women. In pre-eclamptic compared with normotensive pregnancy, carotid arterial IMT (459 ± 95 vs. 351 ± 85 μm, P=0.0001), internal diameter (7.8 ± 0.5 vs. 7.2 ± 0.4 mm, P<0.0001), pulse wave velocity (7.1 ± 1.7 vs. 6.0 ± 1.5 m/s, P=0.007), augmentation index (7.9 ± 9.2 vs. −5.0 ± 5.6%, P<0.0001) and arterial wall tension (55.0 ± 6.5 vs. 38.6 ± 4.9 mmHg/cm, P<0.0001) were significantly greater, and the distensibility coefficient (0.020 ± 0.009 vs. 0.029 ± 0.011 1/kPa, P=0.006) was significantly smaller, remaining so after adjusting for body mass index and carotid arterial pressure. Eighteen months after parturition, carotid arterial internal diameter, pressure and wall tension remained greater in the pre-eclamptic group. Carotid arterial remodeling, including changes in arterial internal diameter and wall thickness, and arterial stiffening occur in pre-eclampsia but this may reverse, to some extent, postpartum. QIMT and QAS techniques together could provide a comprehensive assessment of carotid arterial remodeling.

Insights into the mechanism(s) of von Willebrand factor degradation during mechanical circulatory support

Left ventricular assist device support produces a bleeding diathesis. Evidence suggests a major role for von Willebrand factor (vWF). We examined vWF metabolism in a preclinical model of short-term mechanical circulatory support. In 25 calves (weight, 80-110 kg), the inflow/outflow graft of the Symphony Heart Assist System was sewn end-to-side to the carotid artery. Support was initiated (acute, n=4; 1 week, n=16; 2 weeks, n=5). Acutely, carotid artery pressure and flow were measured to evaluate the hemodynamic changes near the anastomosis. At baseline and after ≤2 weeks of support, platelet aggregometry with adenosine 5'-diphosphate, collagen, and ristocetin was performed. Gel electrophoresis and wet immunoblotting qualitatively evaluated vWF multimers and quantified plasma ADAMTS-13, the vWF-cleaving protease. Carotid arterial rings near the anastomosis were studied with immunohistochemical staining for ADAMTS-13 and were cultured to quantify endothelial ADAMTS-13 production. Fluorescent resonance energy transfer was used to evaluate the enzymatic activity of ADAMTS-13 in the plasma and in supernatant from cultured carotid arterial rings. Plasma interleukin-6, which inhibits ADAMTS-13 activity, was measured using an enzyme-linked immunosorbent assay. During support, statistically significant (P<.05) changes in the carotid endothelium arterial hemodynamics were observed. The highest molecular weight vWF multimers were absent, and the vWF-ristocetin platelet aggregation pathway was significantly impaired. A modest but significant increase in plasma ADAMTS-13 protein and activity was observed. ADAMTS-13 decreased significantly in the carotid near the anastomosis but increased significantly in supernatant from cultured carotid arterial rings. The plasma interleukin-6 levels did not change significantly. Hemodynamic activation of vWF and increased plasma ADAMTS-13 activity may have reduced high-molecular-weight vWF multimers and thereby impaired the vWF-platelet aggregation pathway. Additional delineation of these pathways may improve management of left ventricular assist device-associated bleeding.

A novel approach to assess hemorrhagic shock severity using the arterially determined left ventricular isovolumic contraction period

Recently, the ventilatory variation in pre-ejection period (ΔPEP) was found to be useful in the prediction of fluid-responsiveness of patients in shock. In the present study we investigated the behavior of the ventilation-induced variations in the systolic timing intervals in response to a graded hemorrhage protocol. The timing intervals studied included the ventilatory variation in ventricular electromechanical delay (ΔEMD), isovolumic contraction period (determined from the arterial pressure waveform, ΔAIC), pulse travel time (ΔPTT), and ΔPEP. ΔAIC and ΔPEP were evaluated in the aorta and carotid artery (annotated by subscripts Ao and CA) and were compared with the responses of pulse pressure variation (ΔPPAo) and stroke volume variation (ΔSV). The graded hemorrhage protocol, followed by resuscitation using norepinephrine and autologous blood transfusion, was performed in eight anesthetized Yorkshire X Landrace swine. ΔAICAo, ΔAICCA, ΔPEPAo, ΔPEPCA, ΔPPAo, ΔPPCA, and ΔSV showed significant increases during the graded hemorrhage and significant decreases during the subsequent resuscitation. ΔAICAo, ΔAICCA, ΔPEPAo, and ΔPEPCA all correlated well with ΔPPAo and ΔSV (all r ≥ 0.8, all P < 0.001). ΔEMD and ΔPTT did not significantly change throughout the protocol. In contrast with ΔPEPAo, which was significantly higher than ΔPEPCA (P < 0.01), ΔAICAo was not different from ΔAICCA. In conclusion, ventilation-induced preload variation principally affects the arterially determined isovolumic contraction period (AIC). Moreover, ΔAIC can be determined solely from the arterial pressure waveform, whereas ΔPEP also requires ECG measurement. Importantly, ΔAIC determined from either the carotid or aortic pressure waveform are interchangeable, suggesting that, in contrast with ΔPEP, ΔAIC may be site independent.

Carotid Artery Back Pressure and Cerebral Intolerance During the Occlusion in Carotid Stenting with the Mo.Ma Proximal Embolic Protection Device

OP-173 The Mo.Ma proximal embolic protection system provide neuroprotection during all phases of the carotid artery stenting (CAS) procedure. However, cerebral intolerance is not an infrequent occurrence with this approach. In most of the cases, intolerance is a benign phenomenon which resolves

Obesity and Overweight Associated With Increased Carotid Diameter and Decreased Arterial Function in Young Otherwise Healthy Men

Obesity is linked to cardiovascular disease, stroke, increased mortality and vascular remodeling. Although increased arterial diameter is associated with multiple cardiovascular risk factors and obesity, it is unknown whether lumen enlargement is accompanied by unfavorable vascular changes in young and otherwise healthy obese individuals. The purpose of this study was to compare carotid and brachial artery diameter, blood pressure, arterial stiffness, and endothelial function in young, apparently healthy, normal-weight, overweight, and obese male subjects. One hundred sixty-five male subjects (27.39±0.59 years) were divided into 3 groups (normal weight, overweight, and obese) according to body mass index. Subjects underwent cardiovascular measurements to determine arterial diameter, function, and stiffness. After adjusting for age, the obese group had significantly greater brachial, carotid, and aortic pressures, brachial pulse wave velocity, carotid intima media thickness, and carotid arterial diameter compared with both the overweight and normal-weight groups. Obesity is associated with a much worse arterial profile, as an increased carotid lumen size was accompanied by higher blood pressure, greater arterial stiffness, and greater carotid intima media thickness in obese compared with overweight or normal-weight individuals. These data suggest that although obesity may be a factor in arterial remodeling, such remodeling is also accompanied by other hemodynamic and arterial changes consistent with reduced arterial function and increased cardiovascular risk.

Measures of carotid–femoral pulse wave velocity and augmentation index are not reliable in patients with abdominal aortic aneurysm

Measures of carotid-femoral pulse wave velocity (cf-PWV) and carotid augmentation index (cAI) may be affected by the presence of an abdominal aortic aneurysm (AAA). We, therefore, investigated series of various measures of arterial stiffness and wave reflections in patients with AAA, before and 4 weeks after endovascular aneurysm repair (EVAR). A total of 51 patients (75.2 ± 11.6 years, 92.2% men) underwent EVAR for AAA and 51 controls with matched age, sex, SBP, and comorbidity were enrolled. Measures of aortic stiffness included cf-PWV by tonometry and brachial-ankle pulse wave velocity (ba-PWV) by plethysmography. Measures of wave reflections included cAI and the reflected pressure wave amplitude (Pb) from a decomposed carotid pressure wave. Patients with AAA had significantly lower cf-PWV (12.1 ± 2.7 versus 13.6 ± 3.5 m/s P=0.009), higher cAI (30.8 ± 12.2 versus 23.1 ± 23.3%, P=0.040) in comparison with controls. After EVAR for AAA, cf-PWV (14.4 ± 3.8 ms) increased significantly (P<0.001), and cAI (24.4 ± 14.5%) decreased significantly (P=0.004). In contrast, ba-PWV and Pb values were similar to those in controls and did not change significantly after EVAR. Furthermore, the heart rate and mean BP adjusted post-EVAR cf-PWV, ba-PWV, cAI, and Pb were similar to the corresponding values in controls. In patients with AAA, a lower cf-PWV and a higher cAI are expected, which do not represent true degrees of arterial stiffness and wave reflections. EVAR may correct the impacts of AAA on cf-PWV and cAI.