Regression of radial artery wall hypertrophy and improvement of carotid artery compliance after long-term antihypertensive treatment in elderly patients

Assessment of aortic to peripheral vascular stiffness and gradient by segmented upper limb PWV in healthy and hypertensive individuals

Theoretically pulse wave velocity (PWV) is obtained by calculating the distance between two waveform probes divided by the time difference, and PWV ratio is used to assess the arterial stiffness gradient (SG) from proximal to distal. The aim was to investigate segmental upper-limb PWV (ulPWV) differences and the effects of hypertension and or aging on each ulPWV and SG. The study collected multi-waveform signals and conduction distances from 167 healthy individuals and 92 hypertensive patients. The results showed significant differences between ulPWVs (P < 0.001), with increased and then decreased vascular stiffness along the proximal transmission to the distal peripheral artery and then to the finger. Adjusted for age and sex, ulPWVs in hypertension exceeded that of healthy individuals, with significant differences between groups aged ≥ 50 years (P < 0.05). The hrPWV/rfPWV (heart-radial/radial-finger) was reduced in hypertension and differed significantly between the aged ≥ 50 years (P = 0.015); the ratio of baPWV (brachial-ankle) to ulPWV differed significantly between groups (P < 0.05). Hypertension affected the consistency of rfPWV with hfPWV (heart-finger). The findings suggest that segmented ulPWV is instrumental in providing stiffness corresponding to the physiological structure of the vessel. The superimposition of hypertension and or aging exacerbates peripheral arterial stiffness, as well as alteration in stiffness gradient.

Radial artery diameter: a comprehensive systematic review of anatomy

AIMS

The objective of this systematic review is to determine with the highest accuracy the average radial artery (RA) diameter overall and in certain subgroups. The aim of this study is to provide assistance in the development of fitting transradial devices, an increasingly popular intervention.

METHODS

Several databases were used to extract appropriate studies highlighting RA diameter. Databases used in the generation of this study were Ovid EBM Reviews, Ovid Embase, Ovid Medline, Scopus and Web of Science Core Collection. RA diameter was determined overall, in males versus females, adults only, adults+children, in the presence of comorbidities, and finally RA diameter in the context of various vasodilators.

RESULTS

A total of 71 studies were included. The average RA diameter overall was determined to be 2.62±0.15 mm in children+adults and 2.70±0.15 mm in adults only. In comparison to an RA diameter of 2.68±0.24 mm in adult males, the diameter was found to be 2.27±0.27 mm in adult females (p=0.028). As for comorbidities, the mean RA diameter in adult patients with hypertension and congestive heart failure was 2.72±0.37 mm and 2.80±0.25 mm, respectively. Finally, the mean RA diameter with nitrate and angiotensin-converting enzyme (ACE) inhibitor use was 2.97±0.53 mm and 2.82±0.29 mm respectively. For comparison, the average outer diameter of a 5 French introducer sheath is 2.29 mm and a 6 French introducer sheath is 2.62 mm.

CONCLUSIONS

The findings presented in this study will help determine the most appropriate transradial device to use in several different populations in the context of vasodilator usage or the absence thereof.

A Non-invasive Radial Arterial Compliance Measuring Method using Bio-Impedance

Arterial compliance is one of the essential indicators of certain types of cardiovascular disease, with both systematic and local compliance exhibiting significance. Radial arterial compliance (RAC) has been regarded as an important type of local compliance in several long-term pathophysiological studies. Bio-Impedance (Bio-Z) is a non-invasive signal which can be used to unobtrusively monitor blood volume changes, captured using wearable sensors. In this paper, a compliance monitoring technique based on Bio-Z is proposed for long-term RAC measurements. Both the distensibility-blood pressure (BP) relation and compliance-mean artery pressure relation are analyzed to observe interparticipant compliance variations from four healthy participants, by controlling the blood flow in a way similar to the oscillometric method for BP measurement. A Bio-Z based compliance index (DBZI) is proposed that can be leveraged for continuous and unobtrusive sensing paradigms. A consecutive seven-day experiment shows that the mean and standard deviation values of the difference between the median value of the Bio-Z based beat-by-beat calculated compliance and DBZI are 0.17 and 0.20 mOhm/mmHg, respectively. This demonstrates the consistency and repeatability of the measurements. The results show that DBZI can track the Bio-Z based compliance with an error of 9.72% and 11.67%, compared to a gold standard, in terms of mean and standard deviation, respectively.

Analysis of sequential ultrasound frames for the measurement of hemodynamic stresses, critical bent buckling pressure, and critical buckling torque of human common carotid atherosclerosis

BACKGROUND

Structural properties of the arterial wall are important diagnostic parameters. The current study aimed at investigating the hemodynamic properties and intima-media thickness changes of the common carotid artery in human subjects with atherosclerosis in order to determine the relationships between these indices.

METHODS

This study presented methods to detect instantaneous changes in the lumen diameter, intima media thickness, longitudinal movement and acceleration, and velocity of the left side of common carotid artery. These parameters were measured in 155 male patients, categorized into control (n = 42), mild (n = 39), moderate (n = 37), and severe (n = 37) carotid stenosis groups by B-mode and Doppler ultrasonography. Extracted parameters were used to estimate the biomechanical properties of arteries, including radial strain, arterial stiffness index, Young's elastic modulus, circumferential stress, shear stress, axial stress, critical bent buckling pressure, and critical buckling torque.

FINDINGS

All biomechanical parameters of common carotid artery were significantly different in patients with mild, moderate, and severe stenosis, compared to the control group (P < 0.05). Moreover, the current results showed a significant correlation between intima media thickness and non-intima media thickness-based biomechanical indices including circumferential strain, stiffness index, and shear stress in different stenosis groups (P < 0.05).

INTERPRETATION

We concluded that the conventional and new indicators such as axial stress, critical bent buckling pressure, critical buckling torque could be useful for evaluating atherosclerosis development and also, may provide more information for physicians and interventional radiologists in designing strategies for decreasing risk in interventional treatment such as stent replacement and differentiation of vulnerable plaques.

Small Resistance Artery Disease and ACE2 in Hypertension: A New Paradigm in the Context of COVID-19

Cardiovascular disease causes almost one third of deaths worldwide, and more than half are related to primary arterial hypertension (PAH). The occurrence of several deleterious events, such as hyperactivation of the renin–angiotensin system (RAS), and oxidative and inflammatory stress, contributes to the development of small vessel disease in PAH. Small resistance arteries are found at various points through the arterial tree, act as the major site of vascular resistance, and actively regulate local tissue perfusion. Experimental and clinical studies demonstrate that alterations in small resistance artery properties are important features of PAH pathophysiology. Diseased small vessels in PAH show decreased lumens, thicker walls, endothelial dysfunction, and oxidative stress and inflammation. These events may lead to altered blood flow supply to tissues and organs, and can increase the risk of thrombosis. Notably, PAH is prevalent among patients diagnosed with COVID-19, in whom evidence of small vessel disease leading to cardiovascular pathology is reported. The SARS-Cov2 virus, responsible for COVID-19, achieves cell entry through an S (spike) high-affinity protein binding to the catalytic domain of the angiotensin-converting enzyme 2 (ACE2), a negative regulator of the RAS pathway. Therefore, it is crucial to examine the relationship between small resistance artery disease, ACE2, and PAH, to understand COVID-19 morbidity and mortality. The scope of the present review is to briefly summarize available knowledge on the role of small resistance artery disease and ACE2 in PAH, and critically discuss their clinical relevance in the context of cardiovascular pathology associated to COVID-19.

Comparison of 24-Hour Ambulatory Central Blood Pressure Reduction Efficacy Between Fixed Amlodipine or Up-Titrated Hydrochlorothiazide Plus Losartan: The K-Central Study

OBJECTIVE

The main objective of this study was to evaluate non-inferiority of office mean systolic blood pressure (BP) reduction efficacy and superiority of 24-hour ambulatory central BP reduction efficacy between losartan combined with fixed dose amlodipine (L/A group) and dose up-titrated hydrochlorothiazide (L/H group) according to office BP.

METHODS

We conducted a prospective, randomized, double-blind multicenter trial in 231 patients with hypertensive (mean age = 59.2 ± 12.2 years). Patients received losartan 50 mg monotherapy for 4 weeks, followed by additional use of amlodipine 5 mg or hydrochlorothiazide 12.5 mg for 20 weeks after randomization. The patients who did not achieve the BP goal after 4 weeks' randomization received an increased dose of 100 mg/5 mg for the L/A group and 100 mg/25 mg for L/H group, respectively. The 24-hour ambulatory central BP was measured at baseline and after 20 weeks' treatment.

RESULTS

Office mean systolic BP reduction of L/A group was not inferior to L/H group after 4 weeks' treatment (-17.6 ± 13.3 vs. -14.4 ± 12.6 mm Hg, P = 0.0863) and was not significantly different after 20 weeks' treatment. (-15.7 ± 14.0 vs. -14.7 ± 15.1 mm Hg, P = 0.6130) The 24-hour ambulatory central systolic BP was significantly more reduced in the L/A group compared with that in the L/H group after 20 weeks' treatment (-9.37 ± 10.67 vs. -6.28 ± 10.50 mm Hg, P = 0.0407). The 24-hour ambulatory central systolic BP at the completion of the study and its reduction magnitude were independently associated with reductions in aortic pulse wave velocity, pulse pressure, and wave reflection magnitude.

CONCLUSION

Office systolic BP reduction with L/A was not inferior to L/H after 4 week's treatment. The combination of losartan and amlodipine was more favorable in 24-hour ambulatory central hemodynamics beyond BP-lowering efficacy than the combination of losartan and hydrochlorothiazide, regardless of office BP.

CLINICAL TRIALS REGISTRATION

NCT02294539.

Vascular Smooth Muscle Remodeling in Conductive and Resistance Arteries in Hypertension

Cardiovascular disease is a leading cause of death worldwide and accounts for >17.3 million deaths per year, with an estimated increase in incidence to 23.6 million by 2030. ¹ Cardiovascular death represents 31% of all global deaths ² -with stroke, heart attack, and ruptured aneurysms predominantly contributing to these high mortality rates. A key risk factor for cardiovascular disease is hypertension. Although treatment or reduction in hypertension can prevent the onset of cardiovascular events, existing therapies are only partially effective. A key pathological hallmark of hypertension is increased peripheral vascular resistance because of structural and functional changes in large (conductive) and small (resistance) arteries. In this review, we discuss the clinical implications of vascular remodeling, compare the differences between vascular smooth muscle cell remodeling in conductive and resistance arteries, discuss the genetic factors associated with vascular smooth muscle cell function in hypertensive patients, and provide a prospective assessment of current and future research and pharmacological targets for the treatment of hypertension.

Carotid Artery Stiffness and Incident Depressive Symptoms: The Paris Prospective Study III

BACKGROUND

Arterial stiffness may contribute to late-life depression via cerebral microvascular damage, but evidence is scarce. No longitudinal study has evaluated the association between arterial stiffness and risk of depressive symptoms. Therefore, we investigated the association between carotid artery stiffness and incident depressive symptoms in a large community-based cohort study.

METHODS

This longitudinal study included 7013 participants (mean age 59.7 ± 6.3 years; 35.8% women) free of depressive symptoms at baseline. Carotid artery stiffness (high-resolution echo tracking) was determined at baseline. Presence of depressive symptoms was determined at baseline and at 4 and 6 years of follow-up, and was defined as a score ≥7 on the validated Questionnaire of Depression, Second Version, Abridged and/or new use of antidepressant medication. Logistic regression and generalized estimating equations were used.

RESULTS

In total, 6.9% (n = 484) of the participants had incident depressive symptoms. Individuals in the lowest tertile of carotid distensibility coefficient (indicating greater carotid artery stiffness) compared with those in the highest tertile had a higher risk of incident depressive symptoms (odds ratio: 1.43; 95% confidence interval: 1.10-1.87), after adjustment for age, sex, living alone, education, lifestyle, cardiovascular risk factors, and baseline Questionnaire of Depression, Second Version, Abridged scores. Results were qualitatively similar when we used carotid Young's elastic modulus as a measure of carotid stiffness instead of carotid distensibility coefficient, and when we used generalized estimating equations instead of logistic regression.

CONCLUSIONS

Greater carotid stiffness is associated with a higher incidence of depressive symptoms. This supports the hypothesis that carotid stiffness may contribute to the development of late-life depression.

Numerical study to evaluate the effect of a surface-based sensor on arterial tonometry

Arterial tonometry is a widely used non-invasive blood pressure measurement method. In contrast to the cuff-based method, it is possible to obtain a continuous pressure profile with respect to systolic and diastolic pressures using this method. However, due to a requirement of arterial tonometry-that a sensor needs to be placed directly above a blood vessel-placement error is inevitable if the measurement device is only capable of measuring local regions. This study assumed that the plate sensor is flexible, thus reducing the placement error. We investigated the pressure distribution along the wrist surface rather than the local region through the contact simulation between the flexible plate sensor and the wrist. As a result, we concluded that there is a unique pressure distribution for any specific wrist, regardless of the length and position of the plate, and that it is possible to measure the blood pressure using the response at the wrist surface to the pressure inside the radial artery.

Computational study to investigate effect of tonometer geometry and patient-specific variability on radial artery tonometry

Tonometry-based devices are valuable method for vascular function assessment and for measurement of blood pressure. However current design and calibration methods rely on simple models, neglecting key geometrical features, and anthropometric and property variability among patients. Understanding impact of these influences on tonometer measurement is thus essential for improving outcomes of current devices, and for proposing improved design. Towards this goal, we present a realistic computational model for tissue-device interaction using complete wrist section with hyperelastic material and frictional contact. Three different tonometry geometries were considered including a new design, and patient-specific influences incorporated via anthropometric and age-dependent tissue stiffness variations. The results indicated that the new design showed stable surface contact stress with minimum influence of the parameters analyzed. The computational predictions were validated with experimental data from a prototype based on the new design. Finally, we showed that the underlying mechanics of vascular unloading in tonometry to be fundamentally different from that of oscillatory method. Due to directional loading in tonometry, pulse amplitude maxima was observed to occur at a significantly lower compression level (around 31%) than previously reported, which can impact blood pressure calibration approaches based on maximum pulse pressure recordings.

A novel non-invasive ultrasonic method to assess total axial stress of the common carotid artery wall in healthy and atherosclerotic men

In the present study, developing a new non-invasive method independent from blood flow, we estimated and compared the total axial stress of the common carotid artery wall in healthy and atherosclerotic subjects. Consecutive ultrasonic images of the common carotid artery of 48 male subjects including healthy, with less and more than 50% stenosis in carotid artery were recorded. Longitudinal displacement and acceleration was extracted from ultrasonic image processing using a block matching algorithm. Furthermore, images were examined using a maximum gradient algorithm and time rate changes of the internal diameter and intima-media thickness were extracted. Finally, axial stress was estimated using an appropriate constitutive equation. Statistical analysis results showed that with stenosis initiation and its progression, axial acceleration and stress increase significantly. According to the results of the present study, maximum axial stress of the arterial wall is 1.713±0.546, 1.993±0.731 and 2.610±0.603 (kPa) in normal, with less and more than 50% stenosis in carotid artery respectively. Whereas minimum axial stress is -1.714±0.676, -1.982±0.663 and -2.593±0.661 (kPa) in normal, with less and more than 50% stenosis in carotid artery respectively. Moreover, internal diameter and intima-media thickness of the artery also increase significantly with stenosis initiation and its progression. In this study, the feasibility of axial wall stress computation for human common carotid arteries based on non-invasive in vivo clinical data is concluded. We found a strong and graded association between axial stress and severity of carotid stenosis, which might be used to discriminate healthy from atherosclerotic arteries.

Increased aortic stiffness and blood pressure in non-classic Pompe disease

Vascular abnormalities and glycogen accumulation in vascular smooth muscle fibres have been described in Pompe disease. Using carotid-femoral pulse wave velocity (cfPWV), the gold standard methodology for determining aortic stiffness, we studied whether aortic stiffness is increased in patients with Pompe disease. Eighty-four adult Pompe patients and 179 age- and gender-matched volunteers participated in this cross-sectional case-controlled study. Intima media thickness and the distensibility of the right common carotid artery were measured using a Duplex scanner. Aortic augmentation index, central pulse pressure, aortic reflexion time and cfPWV were assessed using the SphygmoCor® system. CfPWV was higher in patients than in volunteers (8.8 versus 7.4 m/s, p < 0.001). This difference was still present after adjustment for age, gender, mean arterial blood pressure (MAP), heart rate and diabetes mellitus (p = 0.001), and was shown by subgroup analysis to apply to the 40-59 years age group (p = 0.004) and 60+ years age group (p = 0.01), but not to younger age groups (p = 0.99). Except for a shorter aortic reflexion time (p = 0.02), indirect indicators of arterial stiffness did not differ between patients and volunteers. Relative to volunteers (20%), more Pompe patients had a history of hypertension (36%, p = 0.005), and the MAP was higher than in volunteers (100 versus 92 mmHg, p < 0.001). This study shows that patients with non-classic Pompe disease have increased aortic stiffness and blood pressure. Whether this is due to glycogen accumulation requires further investigation. To reduce the potential risk of cardiovascular diseases, we recommend that blood pressure and other common cardiovascular risk factors are monitored regularly.

Antihypertensive drugs and arterial stiffness

Arterial stiffness is recognized as an important determinant of outcome in the hypertensive population. Although pulse pressure is an indirect index more recently relatively simple non-invasive techniques to measure pulse wave velocity, particularly in the aorta and arterial wave analysis have been developed and applied to clinical trials. There are clear differences in the effects of antihypertensive drugs on these parameters and stiffness is becoming a therapeutic target in its own right.

The changing face of vascular interventional radiology: the future role of pharmacotherapies and molecular imaging

Interventional radiology has had to evolve constantly because there is the ever-present competition and threat from other specialties within medicine, surgery, and research. The development of new technologies, techniques, and therapies is vital to broaden the horizon of interventional radiology and to ensure its continued success in the future. In part, this change will be due to improved chronic disease prevention altering what we treat and in whom. The most important of these strategies are the therapeutic use of statins, Beta-blockers, angiotensin-converting enzyme inhibitors, and substances that interfere with mast cell degeneration. Molecular imaging and therapeutic strategies will move away from conventional techniques and nano and microparticle molecular technology, tissue factor imaging, gene therapy, endothelial progenitor cells, and photodynamic therapy will become an important part of interventional radiology of the future. This review looks at these new and exciting technologies.

Morphological macrovascular alterations in complex regional pain syndrome type I demonstrated by increased intima-media thickness

Background

Although intima-media thickness (IMT) was increased in several inflammatory diseases, studies investigating whether the inflammatory processes lead to macrovascular alteration with increased IMT in complex regional pain syndrome (CRPS) lack.

Methods

Using ultrasound (high-resolution B-mode), we compared bilaterally the IMT of the common carotid artery (CCA-IMT), the radial artery (RA-IMT), the brachial artery (BRA-IMT) and the quotient Q_RA/CCA, in CRPS type I (n=17), peripheral nerve injury (PNI, n=17) and pain-free controls (PFC, n=22, matched to CRPS by gender, age and traditional cardiovascular risk factors). Statistics: Spearman’s correlation, paired t-test, ANOVA (p<0.05).

Results

Compared to PFC, RA-IMT were significantly increased in both patient groups bilaterally (mean±standard deviation, CRPS affected side vs. PFC dominant side: 0.32±0.08 mm vs. 0.19±0.08 mm, p<0.001; PNI affected side vs. PFC dominant side: 0.27±0.09 mm vs. 0.19±0.08 mm, p< 0.05; CRPS non-affected side vs. PFC non-dominant side: 0.30±0.10 mm vs. 0.19±0.09 mm, p<0.001; PNI non-affected side vs. PFC non-dominant side: 0.25±0.10 mm vs. 0.19±0.09 mm, p<0.05) and Q_RA/CCA (CRPS affected-side vs. PFC dominant side: 0.49±0.12 vs. 0.30±0.11, p<0.001; PNI affected side vs. PFC dominant side: 0.41±0.10 vs. 0.30±0.11, p<0.05; CRPS non-affected side vs. PFC non-dominant side: 0.43±0.19 vs. 0.30±0.13, p<0.001; PNI non-affected side vs. PFC non-dominant side: 0.39±0.14 vs. 0.30±0.13, p<0.05), and BRA-IMT - only on the affected side in CRPS (CRPS: 0.42±0.06 mm vs. PFC: 0.35±0.08 mm; p<0.05). In CRPS, Q_RA/CCA was significantly higher on the affected side compared to PNI (p<0.05). However, only CRPS displayed within-group side-to-side differences with a significantly increased RA-IMT and Q_RA/CCA on the affected side (p<0.05). The CCA-IMT was comparable between all groups and sides.

Conclusions

The increased IMT of peripheral arteries in CRPS suggests ongoing inflammatory process. Until now, only endothelial dysfunction has been reported. The presented morphological macrovascular alterations might explain the treatment resistance of some CRPS patients.

Effect of Angiotensin-converting enzyme inhibitors and Angiotensin receptor antagonists in atherosclerosis prevention

Atherosclerosis is a highly complex biological process that has become the scourge of modern civilization. Endothelial dysfunction is the first step in the development of atherosclerosis. The renin-angiotensin-aldosterone system (RAAS) plays an important role in the development of endothelial dysfunction and atherosclerosis. Several studies have shown that in vitro blockade of the RAAS is associated with improvement in markers of endothelial dysfunction and inflammation. Many clinical trials have demonstrated a clear benefit of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) manifested by a reduction of cardiovascular events. These findings suggest that ACEIs and ARBs can play an important role in prevention of atherosclerosis and in the delay of its progression. In this review we focus on the importance of RAAS blockade to prevent or delay progression of atherosclerosis and its impact on reduction of cardiovascular events.

Perindopril protects against streptozotocin-induced hyperglycemic myocardial damage/alterations

High blood pressure, obesity, abnormal lipid profile, which often coexist with diabetes, tend to be associated with preclinical cardiovascular abnormalities and may contribute to the association of diabetes with cardiovascular events. Many studies have proved that streptozotocin (STZ) is responsible for type-2-diabetes-induced cardiovascular complications. Long-term perindopril therapy in patients with hypertension and diabetes has been observed to correct carotid remodeling by reducing hypertrophy. We studied the effect of perindopril (1 mg/kg/d orally [po]) on cardiovascular complications in neonatal model of rats, which was induced by administering STZ (90 mg/kg, intraperitoneally [ip]), in 5-d-old wistar rats and cardiac hypertrophy induced by isoprenaline (ISO; 5 mg/kg, ip) for 10 d. Various biochemical, cardiac, and hemodynamic parameters were measured at the end of 8 weeks of treatment in diabetes model and 10 d in hypertrophy model. STZ produced hyperglycemia, hyperinsulinemia, dyslipidemia, hypertension, bradycardia, increased creatinine kinase (CK-MB), lactate dehydrogenase enzymes (LDH) and C-reactive protein (CRP) levels, cardiac hypertrophy, and oxidative stress. Chronic treatment with perindopril significantly prevented STZ-induced hyperglycemia and hyperinsulinemia and controlled dyslipdemia in diabetic rats. Further, perindopril produced a significant reduction in elevated levels of CRP, LDH, and CK. STZ-induced hypertension and bradycardia were also prevented by perindopril treatment. Perindopril also produced beneficial effect by preventing cardiac hypertrophy as evident from cardiac hypertrophy index and left ventricular hypertrophic index. Perindopril also prevented STZ-induced oxidative stress. Similar results were obtained in ISO-induced cardiac hypertrophic model, which confirms the beneficial role of perindopril in cardiac hypertrophy. In conclusion, our data from both studies suggest that perindopril produced beneficial effect on cardiac complications.

Arterial stiffness: from physiology to clinical implications

Current European guidelines for the management of arterial hypertension introduce the assessment of arterial stiffness by pulse wave velocity (PWV) as an index of hypertension-related cardiovascular target organ damage. An increase in arterial stiffness is related to haemodynamic modifications at the level of the aorta, leading to a rise in cardiac afterload, a reduction in coronary perfusion and an overstretch of the aortic walls. An increasing number of studies have demonstrated the accuracy of PWV as an independent predictor of cardiovascular events and cardiovascular mortality in patients with different co-morbidities and cardiovascular risk. Many strategies have demonstrated their efficacy in preventing arterial stiffening; therapy of arterial hypertension is the mainstay in the management of patients with increased PWV and altered pulse wave reflection. Literature has clearly shown the specific efficacy of drugs interfering with the renin-angiotensin-aldosterone system and calcium-channel blockers in the control of central haemodynamics, particularly when compared with β-blockers (β-adrenoceptor antagonists). The same action has not yet been demonstrated on PWV. Further studies are needed to assess the real relative efficacy of different drug classes on the management of arterial stiffness and the clinical and prognostic relevance of these therapies.

Chronic kidney disease is associated with increased carotid artery stiffness without morphological changes in participants of health check-up programs

BACKGROUND AND METHODS

Patients with chronic kidney disease (CKD) show a much higher risk of cardiovascular disease. However, the mechanisms underlying this association and the impact of CKD on behaviors of the vascular walls have not been fully clarified. Using ultrasonography, this study investigated associations of CKD (estimated glomerular filtration rate <60 ml/min/1.73 m(2) and/or presence of proteinuria) with both elasticity (stiffness β index) of the carotid artery and intimal atherosclerotic changes in participants of health check-up programs (n=3406, 63% men; mean age, 58.8 years).

RESULTS

Stiffness β was significantly higher in CKD subjects (7.49 ± 0.14) than in non-CKD subjects (6.87 ± 0.05, P<0.001). This significant difference was maintained in a multiple adjusted model including conventional risk factors such as hypertension, diabetes mellitus, dyslipidemia, smoking and obesity (7.20 ± 0.14 vs. 6.91 ± 0.05, P=0.043). No significant differences in intima-media complex thickness or plaque score were seen between CKD and non-CKD subjects.

CONCLUSION

In participants of health check-up programs, CKD was associated with increased carotid arterial stiffness without intimal disease, independently of conventional risk factors. These findings indicate that CKD may predispose the carotid arteries to earlier development of arteriosclerosis, characterized by increased arterial stiffness.

Critical appraisal of the differential effects of antihypertensive agents on arterial stiffness

Increased central arterial stiffness, involving accelerated vascular ageing of the aorta, is a powerful and independent risk factor for early mortality and provides prognostic information above and beyond traditional risk factors for cardiovascular disease (CVD). Central arterial stiffness is an important determinant of pulse pressure; therefore, any pathological increase may result in left ventricular hypertrophy and impaired coronary perfusion. Central artery stiffness can be assessed noninvasively by measurement of aortic pulse wave velocity, which is the gold standard for measurement of arterial stiffness. Earlier, it was believed that changes in arterial stiffness, which are primarily influenced by long-term pressure-dependent structural changes, may be slowed but not reversed by pharmacotherapy. Recent studies with drugs that inhibit the renin-angiotensin-aldosterone system, advanced glycation end products crosslink breakers, and endothelin antagonists suggest that blood pressure (BP)-independent reduction and reversal of arterial stiffness are feasible. We review the recent literature on the differential effect of antihypertensive agents either as monotherapy or combination therapy on arterial stiffness. Arterial stiffness is an emerging therapeutic target for CVD risk reduction; however, further clinical trials are required to confirm whether BP-independent changes in arterial stiffness directly translate to a reduction in CVD events.

Arterial structure and function after recovery from the metabolic syndrome: the cardiovascular risk in Young Finns Study

BACKGROUND

The reversibility of ultrasonographic vascular changes associated with the metabolic syndrome (MetS) recovery is unknown. We examined whether spontaneous recovery from MetS (according to the International Diabetes Federation definition) has a favorable effect on vascular properties and evaluated the associations between lifestyle factors and MetS recovery.

METHODS AND RESULTS

We measured carotid artery intima-media thickness, distensibility, and brachial flow-mediated dilatation by ultrasound in 1673 subjects of the Young Finns Study cohort (age, 31.5+/-5.0 years in 2001) who participated in follow-up studies in 2001 and 2007. At baseline, no differences in intima-media thickness, carotid artery distensibility, or flow-mediated dilatation were observed between the recovery group (baseline-only MetS) and those with incident (only at follow-up) or persistent (both at baseline and follow-up) MetS. After 6 years, the recovery group had smaller intima-media thickness (mean+/-SEM, 0.62+/-0.01 versus 0.68+/-0.01 mm; P=0.0009) and higher carotid artery distensibility (1.98+/-0.07%/mm Hg versus 1.56+/-0.04%/mm Hg; P=0.001) compared with the persistent group and higher flow-mediated dilatation compared with the control group (9.91+/-0.51% versus 8.57+/-0.12%; P=0.03). The recovery group had reduced intima-media thickness progression compared with the persistent group (0.036+/-0.005 versus 0.079+/-0.010 mm; P=0.001) and reduced carotid artery distensibility change compared with the incident group (-0.12+/-0.05%/mm Hg versus -0.38+/-0.10%/mm Hg; P=0.03) over the 6-year follow-up. Differences in carotid artery distensibility levels were attenuated (P=0.11) after the inclusion of weight change in the models. MetS recovery was paralleled with significant reductions in waist circumference that independently correlated with increased physical activity and increased attention paid to health habits during the follow-up.

CONCLUSIONS

Recovery from the MetS was associated with positive effects on vascular properties during a 6-year follow-up period of young adults.

The macrocirculation and microcirculation of hypertension

Changes in vascular structure that accompany hypertension may contribute to hypertensive end-organ damage. Both the macrovascular and microvascular levels should be considered, as interactions between them are believed to be critically important. Regarding the macrocirculation, the article first reviews basic concepts of vascular biomechanics, such as arterial compliance, arterial distensibility, and stress-strain relationships of arterial wall material, and then reviews how hypertension affects the properties of conduit arteries, particularly examining evidence that it accelerates the progressive stiffening that normally occurs with advancing age. High arterial stiffness may increase central systolic and pulse pressure by two different mechanisms: 1) Abnormally high pulse wave velocity may cause pressure waves reflected in the periphery to reach the central aorta in systole, thus augmenting systolic pressure; 2) In the elderly, the interaction of the forward pressure wave with high arterial stiffness is mostly responsible for abnormally high pulse pressure. At the microvascular level, hypertensive disease is characterized by inward eutrophic or hypertrophic arteriolar remodeling and capillary rarefaction. These abnormalities may depend in part on the abnormal transmission of highly pulsatile blood pressure into microvascular networks, especially in highly perfused organs with low vascular resistance, such as the kidney, heart, and brain, where it contributes to hypertensive end-organ damage.

Perindopril: beyond lowering blood pressure

Perindopril, a prodrug ester of perindoprilat, is an angiotensin-converting enzyme inhibitor that lowers angiotensin II and potentiates bradykinin. This agent has proven efficacy in a wide range of cardiovascular diseases. Its efficacy, safety and tolerability are well established in the treatment of hypertension. Beyond pharmacodynamic effects shown in lowering blood pressure, perindopril was also involved in the improvement of endothelial function and the normalization of vascular and cardiac structure and function. Large morbidity-mortality trials, such as the European Trial on Reduction of Cardiac Events with Perindopril in Patients with Stable Coronary Artery Disease (EUROPA), Perindopril Protection Against Recurrent Stroke Study (PROGRESS) and Anglo-Scandinavian Cardiac Outcomes Trial-Blood Pressure Lowering Arm (ASCOT-BPLA), have shown that treatment with perindopril reduces and prevents cardiovascular disease in a large range of patients with vascular diseases (including stable coronary disease), whether or not they are hypertensive.

Study of the intima-media thickening in carotid arteries of healthy elderly with high blood pressure and elderly with high blood pressure and dyslipidemia

OBJECTIVE

The objective of this study was to assess the mean intima-media thickening of carotid arteries of elderly subjects, and its relationship with age, anthropometric measurements, high systolic blood pressure and dyslipidemia.

METHODS

In this investigation, 129 subjects were enrolled between 1995 and 1998, age ranging from 29 to 94 years. They were assigned to one of 4 groups, including 2 control groups (group I, of healthy younger subjects; group II of healthy elderly subjects). Groups III and IV included those who presented with isolated systolic hypertension (ISH), and ISH and dyslipidemia, respectively. All subjects were submitted to a medical interview, lab tests with measurement of cholesterol levels, electrocardiogram, and carotid ultrasound. The ultrasound included measurement of the intima-media thickening (IMT) of the carotid arteries, the right carotid artery (RCA) and left carotid artery (LCA), and assessment of the presence of plaques. Blood fat and glucose were measured by a standard method. The results were compared among the groups through statistical tests. The tests employed were: Chi-Square, Pearson's and Likelihood Ratio, Student's t, Mann-Whitney; ANOVA followed by Tukey's test, Kruskal-Wallis nonparametric test, and test for multiple comparisons and Odds Ratio determination (OR).

RESULTS

In this investigation, a positive association was observed between aging and IMT. In relation to systolic hypertension, a significant association was observed with IMT (IMT-RCA p = 0.0034; IMT-LCAp = 0.0196; IMT-RLCAp = 0.0299), and with the presence of plaques (PlaqueR p = 0.0110; PlaqueL p = 0.0294; PlaqueRL p = 0.0040).

CONCLUSION

This investigation evidenced the important role of aging in IMT, and of systolic hypertension in the IMT and presence of plaque. However, further studies are needed for a better understanding of the actual role of risk factors in aging.

Role of increased aortic stiffness in the pathogenesis of heart failure

Aortic stiffness is an independent predictor of cardiovascular mortality in a variety of patient groups including hypertensives and other unselected patients. Despite a sound pathophysiologic basis, termed the ventricular-vascular coupling mechanism, the relationship between aortic stiffness and heart failure has been less well studied. This review summarizes some important trials of aortic stiffness in cardiovascular disease risk prediction and progression to heart failure. Emerging targets for therapeutics and areas requiring more research are also discussed.

Vascular calcification and arterial stiffness in chronic kidney disease: implications and management

Cardiovascular (CV) disease is the commonest cause of mortality in patients with chronic kidney disease (CKD). Vascular calcification (VC), induced by calcium and phosphate excess and uraemia, is a major risk factor and is independently associated with CV events and death. Local and systemic calcium-regulatory proteins as well as inhibitory extracellular factors are involved in the pathogenesis of VC. In CKD the balance becomes dysregulated leading to differentiation of vascular smooth muscle cells into phenotypically distinct osteoblast-like cells with subsequent ossification of the arterial wall. Associated with imbalances in mineral metabolism, VC has intimate interactions with bone mineralization and enhanced bone resorption. Arterial stiffness represents the functional disturbance of VC, with reduced compliance of large arteries, and predominantly results from greater medial calcification. As with VC, arterial stiffness is an independent predictor of CV mortality and patients with CKD have greater arterial stiffness than the general population resulting in the principal consequences of left ventricular hypertrophy and altered coronary perfusion. Both VC and arterial stiffness can be measured through non-invasive techniques involving computed tomography, ultrasound, echocardiography, and pulse wave velocity. Management in CKD is difficult but detection, prevention and treatment is crucial to reduce CV mortality. The optimal control of mineral metabolism, especially hyperphosphatemia with non-calcium based phosphate binders, has been shown to be effective to reduce VC, and attenuation of arterial stiffness, especially with good blood pressure control, can have a favourable effect with regression of left ventricular hypertrophy. The use of bisphosphonates, calcimimetics, vitamin D therapy and newer experimental treatments, as well as nocturnal dialysis, may have potential benefit.

Angiotensin-converting enzyme and vascular remodeling

Vascular remodeling is the result of a close interplay of changes in vascular tone and structure. In this review, the role of angiotension-converting enzyme (ACE) and the impact of ACE inhibition on vascular remodeling processes during vascular injury and restenosis, hypertension, atherosclerosis, and aneurysm formation are discussed. The role of ACE and angiotensin II (Ang II) in neointimal thickening has been firmly established by animal studies and is mediated by Ang II type 1 (AT(1)) receptor signaling events via monocyte chemoattractant protein-1 and NAD(P)H oxidase. ACE and Ang II are involved in the remodeling of large and resistance arteries during hypertension; here, cell proliferation and matrix remodeling are also regulated by signaling events downstream of the AT(1) receptor. In atherosclerosis, Ang II is involved in the inflammatory and tissue response, mediated by various signaling pathways downstream of the AT(1) receptor. Although ACE inhibition has been shown to inhibit atherosclerotic processes in experimental animal models, results of large clinical trials with ACE inhibitors were not conclusive. Remodeling of vessel dimensions and structure during aneurysm formation is counteracted by ACE inhibition. Here, a direct effect of ACE inhibitors on matrix metalloproteinase activity has to be considered as part of the working mechanism. The role of ACE2 in vascular remodeling has yet to be established; however, ACE2 has been shown to be associated with vascular changes in hypertension and atherosclerosis.

Endothelial function, arterial stiffness and lipid lowering drugs

The endothelium is a dynamic organ that plays a pivotal role in cardiovascular homeostasis. Alteration in endothelial function precedes the development of atherosclerosis and contributes to its initiation, perpetuation and clinical manifestations. It has been suggested that the assessment of endothelial function could represent a barometer of vascular health that could be used to gauge cardiovascular risk. This review summarises the various methods used to assess endothelium-dependent vasodilatation and their potential prognostic implications. In addition, the techniques used to evaluate arterial stiffness are discussed. The latter is to some extent controlled by the endothelium and has been the subject of considerable research in recent years. This paper also discusses the effects of lipid lowering treatment on both endothelial function and arterial stiffness.

Effects of perindopril in hypertensive patients with or without type 2 diabetes mellitus, and with altered insulin sensitivity

Impaired insulin sensitivity and hypertension are risk factors for atherosclerosis, which in turn leads to a variety of cardiovascular diseases. In both conditions, the risks of morbidity and mortality appear to be further increased. Impaired insulin sensitivity is also a precursor for diabetes. The renin-angiotensin-aldosterone system (RAAS) is implicated in the development of both hypertension and insulin resistance. Antihypertensive agents that act by blocking the RAAS, such as angiotensin-converting enzyme (ACE) inhibitors, may improve insulin sensitivity and therefore prevent the deleterious consequences of insulin resistance, including type 2 diabetes. ACE inhibitors appear to improve insulin sensitivity in patients with hypertension and insulin resistance, including diabetes. This review assesses the literature surrounding the use of the ACE inhibitor perindopril in patients with hypertension and varying degrees of insulin resistance, including the effects of perindopril in preventing the development of diabetes and subsequent cardiovascular morbidity and mortality.

Nitric oxide in hypertension

Hypertension is a major risk factor for cardiovascular disease, and reduction of elevated blood pressure significantly reduces the risk of cardiovascular events. Endothelial dysfunction, which is characterized by impairment of nitric oxide (NO) bioavailability, is an important risk factor for both hypertension and cardiovascular disease and may represent a major link between the conditions. Evidence suggests that NO plays a major role in regulating blood pressure and that impaired NO bioactivity is an important component of hypertension. Mice with disruption of the gene for endothelial NO synthase have elevated blood pressure levels compared with control animals, suggesting a genetic component to the link between impaired NO bioactivity and hypertension. Clinical studies have shown that patients with hypertension have a blunted arterial vasodilatory response to infusion of endothelium-dependent vasodilators and that inhibition of NO raises blood pressure. Impaired NO bioactivity is also implicated in arterial stiffness, a major mechanism of systolic hypertension. Clarification of the mechanisms of impaired NO bioactivity in hypertension could have important implications for the treatment of hypertension.

Causes and consequences of increased arterial stiffness in chronic kidney disease patients

Cardiovascular (CV) morbidity and mortality is greatly enhanced in patients with chronic kidney disease, compared to the non-renal population. One key element of this high CV burden appears to be arterial stiffness, as an expression of premature vascular aging. Increased arterial stiffness in renal patients may be a consequence of vascular calcification, chronic volume overload, inflammation, endothelial dysfunction, oxidative stress and several other factors. The authors review briefly the main pathophysiological mechanisms leading to reduced arterial compliance. Increased arterial stiffness has significant clinical consequences: isolated systolic hypertension, left ventricular hypertrophy (and failure), and reduced myocardial perfusion. Better knowledge of the mechanisms of arterial functional and morphologic alteration may help in developing more refined therapeutic strategies aimed to reduce the high CV burden in chronic kidney disease. The potential therapeutic interventions - mainly the use of certain antihypertensive drugs and reduction of vascular calcification - are finally discussed.

Ageing and vascular ageing

There is an age related decline in various physiological processes. Vascular ageing is associated with changes in the mechanical and the structural properties of the vascular wall, which leads to the loss of arterial elasticity and reduced arterial compliance. Arterial compliance can be measured by different parameters like pulse wave velocity, augmentation index, and systemic arterial compliance. There is evidence that arterial compliance is reduced in disease states such as hypertension, diabetes, and end stage renal failure. Changes in arterial compliance can be present before the clinical manifestation of cardiovascular disease. Pharmacological and non-pharmacological measures have been shown to improve arterial compliance. Arterial compliance may constitute an early cardiovascular risk marker and may be useful in assessing the effects of drugs on the cardiovascular system. Pharmacogenetics and genetics of arterial compliance in the future will improve our knowledge and understanding about vascular ageing.

Increased carotid artery stiffness without atherosclerotic change in patients with aortic dissection

The arterial properties and pathogenesis of aortic dissection remain obscure. To examine the arterial properties of patients with aortic dissection, the authors studied the ultrasonographic characteristics of the carotid artery in patients with an aortic dissection (AD, n = 86), and compared these findings with data of patients suffering from arteriosclerosis obliterans (ASO, n = 151), coronary artery disease (CAD, n = 163), and with healthy controls (HC, n = 77). Atherosclerotic intimal changes, such as intima-media thickness (IMT) and plaque formation, were milder in AD than in ASO or CAD (IMT: 0.83 +/- 0.16 vs 0.93 +/- 0.20/0.86 +/- 0.17 mm, p < 0.05; plaque number: 0.6 +/- 1.1 vs 2.7 +/- 2.4/2.5 +/- 2.1, p <0.05). Luminal diameter in AD, ASO, and CAD was significantly higher than in HC. The luminal distensibility in AD was decreased compared with HC but was the same as in ASO and CAD. Intra-AD group analysis showed that in patients with an intramural hematoma (IMH) or a dissection with a thrombosed false lumen (TLF) the IMT was higher than in patients with a classic dissection. In addition, plaque formation was more severe in AD patients with a coexisting abdominal aortic aneurysm (AAA). Reduced distensibility without severe intimal disease was found in AD. These findings suggest that patients with AD may have several arterial alterations, including structural abnormalities. Patients with IMH, TFL, or coexisting AAA may differ from patients who have a classic type of dissection or who do not have AAA, in terms of arterial characteristics including intimal disease and wall elastic property, and the initiating cause of the dissection.

Treatment of isolated systolic hypertension in diabetes mellitus type 2

Age-related arterial stiffness is more pronounced in diabetics compared to non-diabetics, which could explain the prevalence of isolated systolic hypertension (ISH, systolic blood pressure > or =140 mmHg and diastolic blood pressure <90 mmHg) being approximately twice that of the general population without diabetes. Large-scale interventional outcome trials have also shown that diabetics usually have higher pulse pressure and higher systolic blood pressure than non-diabetics. Advanced glycation end-product formation has been implicated in vascular and cardiac complications of diabetes including loss of arterial elasticity, suggesting possibilities for new therapeutic options. With increasing age, there is a shift to from diastolic to systolic blood pressure and pulse pressure as predictors of cardiovascular disease. This may affect drug treatment as different antihypertensive drugs may have differential effects on arterial stiffness that can be dissociated from their effects on blood pressure. While thiazide diuretics are associated with little or no change in arterial stiffness despite a robust antihypertensive effect, angiotensin converting enzyme inhibitors, angiotensin II receptor blockers and calcium-channel blockers have been shown to reduce arterial stiffness. However, combination therapy is nearly always necessary to obtain adequate blood pressure control in diabetics. There are no randomized controlled trials looking specifically at treatment of ISH in diabetics. Recommendations regarding treatment of ISH in diabetes mellitus type 2 are based on extrapolation from studies in non-diabetics, post-hoc analyses and prespecified subgroup analysis in large-scale studies, and metaanalysis. These analyses have clearly demonstrated that blood pressure lowering in ISH confers improved prognosis and reduced cardiovascular and renal outcomes in both diabetics and non-diabetics.

Monitoring vascular health beyond blood pressure

It is well recognized that vascular changes, including atherosclerosis, begin early in life as a silent, asymptomatic disease process and are associated with cardiovascular (CV) risk factors. Importantly, CV risk factors persist or track from childhood to adulthood and are predictive of CV disease risk in adults. Evaluation of arterial stiffness and its predictors may help identify asymptomatic individuals at risk, before blood pressure is elevated above an "arbitrary" level that we currently identify as hypertension. Currently, measurements of arterial stiffness are being used in the research setting and also as part of cardiovascular risk prediction clinics. As the various techniques become more widely available, it is conceivable that the measurement of arterial stiffness could become an important part of the routine assessment of patients in daily practice, as a supplement to blood pressure measurement. Measurement of arterial stiffness will not only be helpful in the detection of early vascular disease but also will be a tool in the follow-up monitoring of strategies aimed at preventing hypertension or reducing further progression of vascular disease before blood pressure elevation can be detected.