Arterial stiffness and pulse pressure in CKD and ESRD

Determination of Peak Oxygen Uptake in Patients with Acute Myocardial Infarction: The Role of Arterial Stiffness in Cardio-Vascular-Skeletal Muscle Coupling

The relationship between arterial stiffness and oxygen uptake (VO2) in patients with acute myocardial infarction (AMI) remains unclear. We aimed to investigate this relationship and factors contributing to VO2 in patients with AMI. The role of arterial stiffness in cardio-skeletal muscle coupling during exercise was then elucidated. Upon discharge, we measured exercise capacity using cardiopulmonary exercise testing (CPX), assessed arterial stiffness with the cardio-ankle vascular index (CAVI), and determined body composition to assess the skeletal muscle mass of 101 patients with AMI. Patients were categorized based on their CAVI scores into three groups: (i) normal (CAVI: ≤7.9), (ii) borderline (CAVI: 8.0-8.9), and (iii) abnormal (CAVI: ≥9.0). Subsequently, VO2 was compared among these groups. The relationship between the CAVI and VO2 Peak during CPX and factors contributing to VO2 Peak were investigated. The abnormal CAVI group had a significantly lower VO2 Peak than the normal and borderline groups. The CAVI was associated with VO2 Peak. Furthermore, the CAVI was found to be a factor contributing to VO2 Peak. These findings suggest that arterial stiffness in tissue blood distribution and blood supply causes systemic exercise limits in patients with AMI. This suggests that arterial stiffness plays a significant role in cardio-vascular-skeletal muscle coupling.

Associations of Glucometabolic Indices with Aortic Stiffness in Patients Undergoing Peritoneal Dialysis with and without Diabetes Mellitus

Disruptions in glucose metabolism are frequently observed among patients undergoing peritoneal dialysis (PD) who utilize glucose-containing dialysis solutions. We aimed to investigate the relationship between glucometabolic indices, including fasting glucose, insulin resistance, advanced glycation end products (AGEs), PD-related glucose load, and icodextrin usage, and aortic stiffness in PD patients with and without diabetic mellitus (DM). This study involved 172 PD patients (mean age 58.3 ± 13.5 years), consisting of 110 patients without DM and 62 patients with DM. Aortic stiffness was assessed using the carotid-femoral pulse wave velocity (cfPWV). Impaired fasting glucose was defined as a fasting glucose level ≥ 100 mg/dL. Homeostatic model assessment for insulin resistance (HOMA-IR) scores, serum AGEs, dialysate glucose load, and icodextrin usage were assessed. Patients with DM exhibited the highest cfPWV (9.9 ± 1.9 m/s), followed by those with impaired fasting glucose (9.1 ± 1.4 m/s), whereas patients with normal fasting glucose had the lowest cfPWV (8.3 ± 1.3 m/s), which demonstrated a significant trend. In non-DM patients, impaired fasting glucose (β = 0.52, 95% confidence interval [CI] = 0.01-1.03, p = 0.046), high HOMA-IR (β = 0.60, 95% CI = 0.12-1.08, p = 0.015), and a high PD glucose load (β = 0.58, 95% CI = 0.08-1.08, p = 0.023) were independently associated with increased cfPWV. In contrast, none of the glucometabolic factors contributed to differences in cfPWV in DM patients. In conclusion, among PD patients without DM, impaired fasting glucose, insulin resistance, and PD glucose load were closely associated with aortic stiffness.

Mean value of pulse pressure: The key feature in ambulatory arterial stiffness index estimation using regression models

OBJECTIVE

Ambulatory arterial stiffness index (AASI) is an index which indicates arterial stiffness. This work aims to explore the mathematical relationship between AASI and mean value of PP (PP‾), and reveal the importance of PP‾ during AASI estimating. Meanwhile, a well-performing AASI estimation model is presented.

METHODS

To evaluate AASI, electrocardiograph (ECG) signal, photoplethysmogram (PPG) signal and arterial blood pressure (ABP) are used as the source of AASI estimation. Features are extracted from the above three signals. Meanwhile, fitting curve analysis and regression models are implemented to describe the relationship between AASI and PP‾.

RESULTS

Among three fitting curves on AASI and PP‾, cubic polynomial curve performs best. The introduction of feature PP‾ in AASI estimation reduced LR's MAE from 0.0556 to 0.0372, SVMR's MAE from 0.0413 to 0.0343 and RFR's MAE from 0.0386 to 0.0256. All three estimation models obtain considerable improvement, especially on the previous worst-performing linear regression.

SIGNIFICANCE

This work presents the mathematical association between AASI and PP‾. AASI estimation using regression models can be significantly improved by involving PP‾ as its key feature, which is not only meaningful for exploring the connection between vascular elasticity function and pulse pressure, but also hold importance for the diagnosis of cardiovascular arteriosclerosis and atherosclerosis at the early stage.

The influence of microenvironment stiffness on endothelial cell fate: Implication for occurrence and progression of atherosclerosis

Atherosclerosis, the primary cause of cardiovascular diseases (CVDs), is characterized by phenotypic changes in fibrous proliferation, chronic inflammation and lipid accumulation mediated by vascular endothelial cells (ECs) and vascular smooth muscle cells (SMCs) which are correlated with the stiffening and ectopic remodeling of local extracellular matrix (ECM). The native residents, ECs and SMCs, are not only affected by various chemical factors including inflammatory mediators and chemokines, but also by a range of physical stimuli, such as shear stress and ECM stiffness, presented in the microenvironmental niche. Especially, ECs, as a semi-selective barrier, can sense mechanical forces, respond quickly to changes in mechanical loading and provide context-specific adaptive responses to restore homeostasis. However, blood arteries undergo stiffening and lose their elasticity with age. Reports have shown that the ECM stiffening could influence EC fate by changing the cell adhesion, spreading, proliferation, cell to cell contact, migration and even communication with SMCs. The cell behaviour changes mediated by ECM stiffening are dependent on the activation of a signaling cascade of mechanoperception and mechanotransduction. Although the substantial evidence directly indicates the importance of ECM stiffening on the native ECs, the understanding about this complex interplay is still largely limited. In this review, we systematically summarize the roles of ECM stiffening on the behaviours of endothelial cells and elucidate the underlying details in biological mechanism, aiming to provide the process of how ECs integrate ECM mechanics and the highlights for bioaffinity of tissue-specific engineered scaffolds.

Meta-Analysis of Pulse Transition Features in Non-Invasive Blood Pressure Estimation Systems: Bridging Physiology and Engineering Perspectives

The pulse transition features (PTFs), including pulse arrival time (PAT) and pulse transition time (PTT), hold significant importance in estimating non-invasive blood pressure (NIBP). However, the literature showcases considerable variations in terms of PTFs' correlation with blood pressure (BP), accuracy in NIBP estimation, and the comprehension of the relationship between PTFs and BP. This inconsistency is exemplified by the wide-ranging correlations reported across studies investigating the same feature. Furthermore, investigations comparing PAT and PTT have yielded conflicting outcomes. Additionally, PTFs have been derived from various bio-signals, capturing distinct characteristic points like the pulse's foot and peak. To address these inconsistencies, this study meticulously reviews a selection of such research endeavors while aligning them with the biological intricacies of blood pressure and the human cardiovascular system (CVS). Each study underwent evaluation, considering the specific signal acquisition locale and the corresponding recording procedure. Moreover, a comprehensive meta-analysis was conducted, yielding multiple conclusions that could significantly enhance the design and accuracy of NIBP systems. Grounded in these dual aspects, the study systematically examines PTFs in correlation with the specific study conditions and the underlying factors influencing the CVS. This approach serves as a valuable resource for researchers aiming to optimize the design of BP recording experiments, bio-signal acquisition systems, and the fine-tuning of feature engineering methodologies, ultimately advancing PTF-based NIBP estimation.

Can the Abdominal Aortic Atherosclerotic Plaque Index Predict Functional Outcomes after Robot-Assisted Partial Nephrectomy?

This study aims to evaluate the abdominal aortic atherosclerotic plaque index (API)'s predictive role in patients with pre-operatively or post-operatively developed chronic kidney disease (CKD) treated with robot-assisted partial nephrectomy (RAPN) for renal cell carcinoma (RCC). One hundred and eighty-three patients (134 with no pre- and post-operative CKD (no CKD) and 49 with persistent or post-operative CKD development (post-op CKD)) who underwent RAPN between January 2019 and January 2022 were deemed eligible for the analysis. The API was calculated using dedicated software by assessing the ratio between the CT scan atherosclerotic plaque volume and the abdominal aortic volume. The ROC regression model demonstrated the influence of API on CKD development, with an increasing effect according to its value (coefficient 0.13; 95% CI 0.04-0.23; p = 0.006). The Model 1 multivariable analysis of the predictors of post-op CKD found that the following are independently associated with post-op CKD: Charlson Comorbidity Index (OR 1.31; p = 0.01), last follow-up (FU) Δ%eGFR (OR 0.95; p < 0.01), and API ≥ 10 (OR 25.4; p = 0.01). Model 2 showed API ≥ 10 as the only factor associated with CKD development (OR 25.2; p = 0.04). The median follow-up was 22 months. Our results demonstrate API to be a strong predictor of post-operative CKD, allowing the surgeon to tailor the best treatment for each patient, especially in those who might be at higher risk of CKD.

Relationship between serum 25-hydroxyvitamin D concentrations and blood pressure among US adults without a previous diagnosis of hypertension: evidence from NHANES 2005-2018

Background

There are various cross-sectional studies that concluded that vitamin D is associated with blood pressure, but randomized controlled studies have not yielded consistent conclusions. Considering many limitations indeed, our study aimed to examine whether concentrations of 25(OH)D are inversely associated with blood pressure in people without a previous diagnosis of hypertension.

Method

We analyzed data from the 2005-2018 National Health and Nutrition Examination Survey. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by applying multivariable logistic regression models. The dose-response relationship was assessed by means of restricted cubic spline regression, and stratification analyses were employed to test the consistency between the subgroups.

Results

Of 17,467 participants aged ≥ 20 years without a previous diagnosis of hypertension, 4,769 had higher blood pressure. Compared with individuals whose 25(OH)D levels were in the bottom quartile (<44.3 nnol/L), adjusting for multiple confounders, the ORs for higher blood pressure were 0.90(95%CI 0.78, 1.05), 0.85(95%CI 0.72, 0.99), and 0.86(95%CI 0.72, 1.02), respectively (P for trend = 0.096). Furthermore, as a continuous variable, 25(OH)D concentrations were non-linearly associated with an increased risk of hypertension (P < 0.001). The interaction between the sleeplessness subgroup and higher blood pressure was significant (P = 0.042).

Conclusion

In adults without a previous diagnosis of hypertension in the United States, concentrations of 25(OH)D were inversely associated with higher blood pressure when it was <84 nmol/L.

Serum Trimethylamine N-Oxide Level Is Positively Associated with Aortic Stiffness Measured by Carotid-Femoral Pulse Wave Velocity in Patients Undergoing Maintenance Hemodialysis

Trimethylamine N-oxide (TMAO) is a biomarker that is effective in predicting major adverse cardiovascular (CV) events. Age-related vascular problems are significantly affected by aortic stiffness (AS), which is independently linked to CV morbidity and mortality. This study aimed to determine the association between serum TMAO levels and carotid-femoral pulse wave velocity (cfPWV) in patients receiving hemodialysis (HD) therapy. In total, 115 patients with HD were enrolled in this study. The AS group included patients whose cfPWV was >10 m/s. Using high-performance liquid chromatography and mass spectrometry, the levels of serum TMAO were measured. The AS group included 42 (36.5%) patients, and compared with the non-AS group, the rates of diabetes, hypertension, older age, systolic blood pressure, serum glucose, and TMAO levels were high. In the multivariate logistic regression analysis, serum TMAO and age were independently linked with AS after correcting for the factors significantly associated with AS. Following multivariate stepwise linear regression analysis, serum TMAO in these individuals was found to be strongly correlated with cfPWV values (p < 0.001). In patients on chronic HD, serum TMAO level is an independent measure of AS and strongly correlated with cfPWV.

Hypertension and Dyslipidemia: the Two Partners in Endothelium-Related Crime

PURPOSE OF REVIEW

The goal of this article is to characterize the endothelium's role in the development of hypertension and dyslipidemia and to point out promising therapeutic directions.

RECENT FINDINGS

Dyslipidemia may facilitate the development of hypertension, whereas the collaboration of these two silent killers potentiates the risk of atherosclerosis. The common pathophysiological denominator for hypertension and dyslipidemia is endothelial cell dysfunction, which manifests as dysregulation of homeostasis, redox balance, vascular tone, inflammation, and thrombosis. Treatment focused on mediators acting in these processes might be groundbreaking. Metabolomic research on hypertension and dyslipidemia has revealed new therapeutic targets. State-of-the-art solutions integrating interview, clinical examination, innovative imaging, and omics profiles along with artificial intelligence have been already shown to improve patients' risk stratification and treatment. Pathomechanisms underlying hypertension and dyslipidemia take place in the endothelium. Novel approaches involving endothelial biomarkers and bioinformatics advances could open new perspectives in patient management.

A Case of Significant Improvement of Heart Failure With Reduced Ejection Fraction With a Small Dose of Candesartan in a Hemodialysis Patient With Hypertensive Heart Disease and Nephrosclerosis

Hypertension induces vascular damage followed by organ damage, including heart failure in hypertensive heart disease (HHD) and nephrosclerosis (the resultant renal pathologic change from long-standing hypertension affecting renal vascular supply), ultimately causing renal failure. Renin-angiotensin-aldosterone system (RAAS) inhibitors are well known as effective drugs for the treatment of hypertension and the anti-remodeling of affected organs. A 52-year-old male was evaluated. Right atrophic kidney and proteinuria were noted in his high school years; however, he had no symptoms for about 35 years. He had pollakiuria in November and oliguria and leg edema in December 2020. The edema deteriorated rapidly, and general fatigue and orthopnea emerged in January 2021. Anasarca, hypertension (198/151 mmHg), tachycardia (115/minute), and hypoxemia (oxygen saturation {SpO2} of 93%) were observed on admission. A bilateral pleural effusion and pulmonary congestion were found on a chest X-ray (CXR) examination. An echocardiogram showed a 22% left ventricle ejection fraction (LVEF). Blood urea nitrogen (BUN) and serum creatinine concentrations were 70 mg/dL and 6.05 mg/dL, respectively. He was diagnosed with nephrosclerosis and HHD-induced cardiac exhaustion. Hemodialysis was started in April 2021. Even though the dry weight was decreased by draining water, cardiomegaly (cardiothoracic ratio {CTR}: 60%), low LVEF (20%-30%), and hypertension, especially diastolic hypertension (140-150/100-120 mmHg), were sustained. After 2 mg of candesartan was added in November 2021, the cardiomegaly, blood pressure (BP), and LVEF were rapidly ameliorated. The CTR and LVEF recovered to 48.5% and 60%, respectively, in April 2022. Statistical analyses showed that the independent factors for CTR were the mean monthly diastolic BP (standard partial regression coefficient {[Formula: see text]}: 0.9058, p<0.0001) and candesartan ([Formula: see text]: -0.7389, p=0.0011) in vital signs and prescribed drugs, respectively. We experienced a case of a significant effect of candesartan treatment against heart failure with reduced ejection fraction (HFrEF) caused by HHD in a hemodialysis patient with nephrosclerosis. Statistical analyses suggested that the improvement of HFrEF resistant to fluid removal by hemodialysis was presumably due to a decrease in diastolic BP caused by a small dose of candesartan.

Severely increased albuminuria in patients with type 2 diabetes mellitus is associated with increased subclinical atherosclerosis in femoral arteries with Na [18F]F activity as a proxy - The DETERMINE study

BACKGROUND AND AIMS

Sodium [18F]fluoride (Na [18F]F) positron emission tomography imaging allows detailed visualization of early arterial micro-calcifications. This study aims to investigate atherosclerosis manifested by micro-calcification, macro-calcification, and aortic stiffness in patients with type 2 diabetes mellitus (T2DM) with and without albuminuria and severely decreased kidney function.

METHODS

A cohort was stratified in four groups (N = 10 per group), based on KDIGO categories (G1-5 A1-3). G1-2A1 non-diabetic controls (median [IQR] estimated glomerular filtration rate (eGFR) in mL/min/1.73 m2 91 [81-104]), G1-2A1 with T2DM (eGFR 87 [84-93], and albumin-creatinin-ratio (ACR) in mg/mmol 0.35 [0.25-0.75]), G1-2A3 with T2DM (eGFR 85 [60-103], and ACR 74 [62-122], and G4A3 with T2DM (eGFR 19 [13-27] and ACR 131 [59-304]).

RESULTS

Na [18F]F femoral artery grading score differed significantly in the groups with the highest Na [18F]F activity in A3 groups with T2DM (G1-2A3 with T2DM 228 [100-446] and G4A3 with T2DM 198 [113-578]) from the lowest groups of the G1-2A1 with T2DM (33 [0-93]) and in G1-2A1 non-diabetic controls (75 [0-200], p = 0.001). Aortic Na [18F]F activity and femoral artery computed tomography (CT)-assessed macro-calcification was increased in G4A3 with T2DM compared with G1-2A1 with T2DM (47.5 [33.8-73.8] vs. 17.5 [8.8-27.5] (p = 0.006) and 291 [170-511] vs. 12.2 [1.41-44.3] mg (p = 0.032), respectively). Carotid-femoral pulse wave velocity (PWV)-assessed aortic stiffness was significantly higher in both A3 groups with T2DM compared with G1-2A1 with T2DM (11.15 and 12.35 vs. 8.86 m/s, respectively (p = 0.009)).

CONCLUSIONS

This study indicates that the presence of severely increased albuminuria in patients with T2DM is cross-sectionally associated with subclinical arterial disease in terms of micro-calcification and aortic stiffness. Additional decrease in kidney function was associated with advanced macro-calcifications.

Uncontrolled hypertension is associated with increased risk of graft failure in kidney transplant recipients: a nationwide population-based study

Backgroud

Hypertension is highly prevalent in patients with kidney transplantation caused by transplantation-related immunologic or non-immunologic risk factors. However, whether a strict definition of hypertension (≥130/80 mmHg) and subdivided blood pressure (BP) groups are associated with an increased risk of graft failure after kidney transplantation using a nationwide large cohort study are still unknown.

Methods

Using Korean National Health Insurance Service data, we included 14,249 patients who underwent kidney transplantation from 2002 to 2016. Patients were categorized into five BP groups according to the 2021 Kidney Disease: Improving Global Outcomes practice guidelines for BP management: normal BP (<120/80 mmHg), elevated BP (120-129/ < 80 mmHg), incident hypertension (≥130/80 mmHg), and controlled or uncontrolled hypertension with anti-hypertensive medications.

Results

The primary outcome was graft failure, which occurred in 1934 (13.6%) participants during the 6-year follow-up. After adjusting for covariates, hypertension was associated with a higher risk of graft failure [Adjusted hazard ratio (AHR), 1.70; 95% confidence interval (CI), 1.48-1.96)] than no-hypertension. The AHR for graft failure was the highest in patients with uncontrolled hypertension (AHR, 2.13; 95% CI, 1.80-2.52). The risk of graft failure had a linear relationship with systolic and diastolic BP, and pulse pressure.

Conclusions

In this nationwide population-based study, hypertension ≥130/80 mmHg based on the 2021 KDIGO BP guidelines in kidney transplantion recipients, and elevated systolic and diastolic BP, and pulse pressure were associated with the risk of developing graft failure in kidney transplant recipients.

The Role of the Vasculature in Heart Failure

The contribution of the vasculature in the development and progression of heart failure (HF) syndromes is poorly understood and often neglected. Incorporating both arterial and venous systems, the vasculature plays a significant role in the regulation of blood flow throughout the body in meeting its metabolic requirements. A deterioration or imbalance between the cardiac and vascular interaction can precipitate acute decompensated HF in both preserved and reduced ejection fraction phenotypes. This is characterised by the increasingly recognised concept of ventricular-arterial coupling: a well-balanced relationship between ventricular and vascular stiffness, which has major implications in HF. Often, the cause of decompensation is unknown, with international guidelines mainly centred on arrhythmia, infection, acute coronary syndrome and its mechanical complications as common causes of decompensation; the vascular component is often underrecognised. A better understanding of the vascular contribution in cardiovascular failure can improve risk stratification, earlier diagnosis and facilitate earlier optimal treatment. This review focuses on the role of the vasculature by integrating the concepts of ventricular-arterial coupling, arterial stiffness and venous return in a failing heart.

Non-Haemodynamic Mechanisms Underlying Hypertension-Associated Damage in Target Kidney Components

Arterial hypertension (AH) is a global challenge that greatly impacts cardiovascular morbidity and mortality worldwide. AH is a major risk factor for the development and progression of kidney disease. Several antihypertensive treatment options are already available to counteract the progression of kidney disease. Despite the implementation of the clinical use of renin-angiotensin aldosterone system (RAAS) inhibitors, gliflozins, endothelin receptor antagonists, and their combination, the kidney damage associated with AH is far from being resolved. Fortunately, recent studies on the molecular mechanisms of AH-induced kidney damage have identified novel potential therapeutic targets. Several pathophysiologic pathways have been shown to play a key role in AH-induced kidney damage, including inappropriate tissue activation of the RAAS and immunity system, leading to oxidative stress and inflammation. Moreover, the intracellular effects of increased uric acid and cell phenotype transition showed their link with changes in kidney structure in the early phase of AH. Emerging therapies targeting novel disease mechanisms could provide powerful approaches for hypertensive nephropathy management in the future. In this review, we would like to focus on the interactions of pathways linking the molecular consequences of AH to kidney damage, suggesting how old and new therapies could aim to protect the kidney.

Aortic Stiffness: A Major Risk Factor for Multimorbidity in the Elderly

Multimorbidity, the coexistence of multiple health conditions in an individual, has emerged as one of the greatest challenges facing health services, and this crisis is partly driven by the aging population. Aging is associated with increased aortic stiffness (AoStiff), which in turn is linked with several morbidities frequently affecting and having disastrous consequences for the elderly. These include hypertension, ischemic heart disease, heart failure, atrial fibrillation, chronic kidney disease, anemia, ischemic stroke, and dementia. Two or more of these disorders (multimorbidity) often coexist in the same elderly patient and the specific multimorbidity pattern depends on several factors including sex, ethnicity, common morbidity routes, morbidity interactions, and genomics. Regular exercise, salt restriction, statins in patients at high atherosclerotic risk, and stringent blood pressure control are interventions that delay progression of AoStiff and most likely decrease multimorbidity in the elderly.

Increased arterial pressure volume index and cardiovascular risk score in China

BACKGROUND AND OBJECTIVE

The new non-invasive arterial stiffness indices, arterial pressure volume index (API) is explored as a novel marker of residual stress in the wall of the peripheral muscular arteries at zero-stress state in clinical settings. The present study aimed to study the association of API with cardiovascular disease (CVD) risk in China (China-PAR).

METHODS

According to China-PAR score, participants were divided into three groups: low risk (< 5%), medium risk (5-9.9%), and high risk (≥ 10.0%). API ≥ 31 was defined as high API, and the incidences of high API were compared. Logistic regression models were used to analyze the risk factors of high API and high risk China-PAR categories. The association between China-PAR and API was analyzed by restrictive cubic spline.

RESULTS

The study included 4311 participants. After adjustments for confounding factors, high API was independent factor associated with high risk China-PAR categories, and the probability of high API was 1.366 times higher than that in normal API subjects. While, the independent factors associated with high API were BMI, blood pressure and heart rate. Furthermore, API had a significant U-shaped association with China-PAR. CVD risk was lowest with API of 19 units, the fastest increase at 26 units and the flattest starting point at 59 units.

CONCLUSION

API, an indicator of arterial stiffness and residual stress, had a U-shaped association with China-PAR score and might play an important role in predicting CVD risk in Chinese natural populations.

Hypertension and cardiomyopathy associated with chronic kidney disease: epidemiology, pathogenesis and treatment considerations

Chronic kidney disease (CKD) is a complex condition with a prevalence of 10-15% worldwide. An inverse-graded relationship exists between cardiovascular events and mortality with kidney function which is independent of age, sex, and other risk factors. The proportion of deaths due to heart failure and sudden cardiac death increase with progression of chronic kidney disease with relatively fewer deaths from atheromatous, vasculo-occlusive processes. This phenomenon can largely be explained by the increased prevalence of CKD-associated cardiomyopathy with worsening kidney function. The key features of CKD-associated cardiomyopathy are increased left ventricular mass and left ventricular hypertrophy, diastolic and systolic left ventricular dysfunction, and profound cardiac fibrosis on histology. While these features have predominantly been described in patients with advanced kidney disease on dialysis treatment, patients with only mild to moderate renal impairment already exhibit structural and functional changes consistent with CKD-associated cardiomyopathy. In this review we discuss the key drivers of CKD-associated cardiomyopathy and the key role of hypertension in its pathogenesis. We also evaluate existing, as well as developing therapies in the treatment of CKD-associated cardiomyopathy.

Fibroblast Growth Factor 23 Exacerbates Cardiac Fibrosis in Deoxycorticosterone Acetate-Salt Mice With Hypertension

Fibroblast growth factor 23 (FGF23) is associated with cardiovascular disease in patients with chronic kidney disease; however, the mechanisms underlying the effect of FGF23 on cardiac function remain to be investigated. Herein, we studied the effect of continuous intravenous (CIV) FGF23 loading in a deoxycorticosterone acetate (DOCA)-salt mouse model with mild chronic kidney disease and hypertension as well as heart failure with a preserved ejection fraction. Wild-type male mice were randomly allocated to 4 groups: normal control, vehicle-treated DOCA-salt mice, FGF23-treated DOCA-salt mice, and FGF23- and calcitriol-treated DOCA-salt mice. The DOCA-salt mice received the agents via the CIV route for 10 days using an infusion minipump. DOCA-salt mice that received FGF23 showed a marked increase in the serum FGF23 level, and echocardiography in these mice revealed heart failure with a preserved ejection fraction. These mice also showed exacerbation of myocardial fibrosis, concomitant with an inverse and significant correlation with Cyp27b1 expression. Calcitriol treatment attenuated FGF23-induced cardiac fibrosis and improved diastolic function via inhibition of transforming growth factor-β signaling. This effect was independent of the systemic and local levels of FGF23. These results suggest that CIV FGF23 loading exacerbates cardiac fibrosis and that locally abnormal vitamin D metabolism is involved in this mechanism. Calcitriol attenuates this exacerbation by mediating transforming growth factor-β signaling independently of the FGF23 levels.

A common Matrix metalloproteinase 8 promoter haplotype enhances the risk for hypertension via diminished interactions with nuclear factor kappa B

OBJECTIVES

Matrix metalloproteinase 8 (MMP8) has a prominent role in collagen turnover in blood vessels and vascular remodeling. The contribution of regulatory single nucleotide polymorphisms in MMP8 to cardiovascular diseases is unclear. We aimed to delineate the influence of MMP8 promoter variations on hypertension.

METHODS

A case-control study in unrelated individuals ( n  = 2565) was carried out. Resequencing of the MMP8 proximal promoter, linkage disequilibrium analysis, genotyping of variants and regression analyses were performed. MMP8 promoter-reporter constructs were generated and expressed in human vascular endothelial cells under various conditions.

RESULTS

We identified four single nucleotide polymorphisms (SNPs) in the promoter region of MMP8 : -1089A/G (rs17099452), -815G/T (rs17099451), -795C/T (rs11225395), -763A/T (rs35308160); these SNPs form three major haplotypes. Hap3 (viz., GTTT haplotype) carriers showed significant associations with hypertension in two geographically distinct human populations (e.g., Chennai: odds ratio [OR] = 1.47, 95% confidence interval [CI] = 1.16-1.86, P  = 2 × 10 -3 ; Chandigarh: OR = 1.85, 95% CI = 1.21-2.81, P  = 4 × 10 -3 ). Hap3 carriers also displayed elevated systolic blood pressure, diastolic blood pressure and mean arterial pressure levels. Hap3 promoter-reporter construct showed lower promoter activity than the wild-type (Hap1) construct. In silico analysis and molecular dynamics studies predicted diminished binding of the transcription factor nuclear factor kappa B (NF-κB) to the functional -815T allele of Hap3 compared to the -815G wild-type allele; this prediction was validated by in-vitro experiments. Hap3 displayed impaired response to tumor necrosis factor-alpha treatment, possibly due to weaker binding of NF-κB. Notably, MMP8 promoter haplotypes were identified as independent predictors of plasma MMP8 and endothelial dysfunction markers (von Willebrand factor and endothelin-1) levels.

CONCLUSION

MMP8 promoter GTTT haplotype has a functional role in reducing MMP8 expression during inflammation via diminished interaction with NF-κB and in enhancing the risk of hypertension.

Effects of Chronic Kidney Disease on Nanomechanics of the Endothelial Glycocalyx Are Mediated by the Mineralocorticoid Receptor

Endothelial mechanics control vascular reactivity and are regulated by the mineralocorticoid receptor (MR) and its downstream target, the epithelial Na⁺ channel (ENaC). Endothelial dysfunction is a hallmark of chronic kidney disease (CKD), but its mechanisms are poorly understood. We hypothesized that CKD disrupts endothelial mechanics in an MR/ENaC-dependent process.

METHODS

Primary human endothelial cells were cultured with uremic serum derived from children with stage 3-5 (predialysis) CKD or adult hemodialysis (HD) patients or healthy controls. The height and stiffness of the endothelial glycocalyx (eGC) and cortex were monitored by atomic force microscopy (AFM) using an ultrasensitive mechanical nanosensor.

RESULTS

In a stage-dependent manner, sera from children with CKD induced a significant increase in eGC and cortex stiffness and an incremental reduction of the eGC height. AFM measurements were significantly associated with individual pulse wave velocity and serum concentrations of gut-derived uremic toxins. Serum from HD patients increased MR expression and mechanical stiffness of the endothelial cortex, an effect reversed by MR and ENaC antagonists, decreased eNOS expression and NO bioavailability, and augmented monocyte adhesion.

CONCLUSION

These data indicate progressive structural damage of the endothelial surface with diminishing kidney function and identify the MR as a mediator of CKD-induced endothelial dysfunction.

Excessive Consumption Hibiscus sabdariffa L. Increases Inflammation and Blood Pressure in Male Wistar Rats via High Antioxidant Capacity: The Preliminary Findings

Hibiscus sabdariffa L. (HSL) has high amounts of antioxidants and many beneficial effects in several pathologies. However, few studies describe the possible harmful effects of high concentrations of HSL. Here we evaluate the effect of excessive and chronic consumption of infusions with different percentages of HSL on some oxidative stress markers in serum, and the possible association with inflammation and increased systolic blood pressure (SBP), in healthy rats. A total of 32 male Wistar rats were used to form 4 groups with 8 animals each. Group 1 control (drinking tap water), group 2, 3 and 4, drinking water supplemented with 15, 30 and 60 g/L of HSL calyxes respectively. SBP was evaluated and determinations in serum of the NO₃⁻/NO₂⁻ ratio, glutathione (GSH), total antioxidant capacity (TAC), selenium (Se), TNF-α, IL-1α/IL-1F1, IL-1β, IL-10, extracellular superoxide dismutase (EcSOD), thioredoxin reductase (TrxR) and glutathione peroxidase (GPx) activities, were evaluated. The SBP (p = 0.01), GPx activity, GSH, TAC, Se, TNF-α and EcSOD activities (p ≤ 0.001) and IL-1α/IL-1F1, IL-1β, TrxR and NO₃⁻/NO₂⁻ (p ≤ 0.05), were increased but IL-10 (p < 0.001) was decreased in rats that consumed the 3 and 6% HSL infusions. The excessive and chronic consumption of HSL may increase the TAC that could lead to a proinflammatory state which is associated with hypertension.

Arterial Stiffness and Diabetes Risk in Framingham Heart Study and UK Biobank

BACKGROUND

Microvascular damage from large artery stiffness (LAS) in pancreatic, hepatic, and skeletal muscles may affect glucose homeostasis. Our goal was to evaluate the association between LAS and the risk of type 2 diabetes using prospectively collected, carefully phenotyped measurements of LAS as well as Mendelian randomization analyses.

METHODS

Carotid-femoral pulse wave velocity (CF-PWV) and brachial and central pulse pressure were measured in 5676 participants of the FHS (Framingham Heart Study) without diabetes. We used Cox proportional hazards regression to evaluate the association of CF-PWV and pulse pressure with incident diabetes. We subsequently performed 2-sample Mendelian randomization analyses evaluating the associations of genetically predicted brachial pulse pressure with type 2 diabetes in the UKBB (United Kingdom Biobank).

RESULTS

In FHS, individuals with higher CF-PWV were older, more often male, and had higher body mass index and mean arterial pressure compared to those with lower CF-PWV. After a median follow-up of 7 years, CF-PWV and central pulse pressure were associated with an increased risk of new-onset diabetes (per SD increase, multivariable-adjusted CF-PWV hazard ratio, 1.36 [95% CI, 1.03-1.76]; P=0.030; central pulse pressure multivariable-adjusted CF-PWV hazard ratio, 1.26 [95% CI, 1.08-1.48]; P=0.004). In United Kingdom Biobank, genetically predicted brachial pulse pressure was associated with type 2 diabetes, independent of mean arterial pressure (adjusted odds ratio, 1.16 [95% CI, 1.00-1.35]; P=0.049).

CONCLUSIONS

Using prospective cohort data coupled with Mendelian randomization analyses, we found evidence supporting that greater LAS is associated with increased risk of developing diabetes. LAS may play an important role in glucose homeostasis and may serve as a useful marker of future diabetes risk.

Vascular aging in adult congenital heart disease-a narrative review

Background and Objective

Many studies about the high prevalence of cardiovascular disease in adults with congenital heart disease (CHD) have been published in response to the growing number of adult patients with CHD. The aging process leads to hypertension and cardiovascular disease, which is caused by a degenerative change in the systemic arterial system characterized by the stiffening of elastic arteries (known as arteriosclerosis) and the enlargement of aorta. In patients with CHD, aortic dilatation (so-called aortopathy) is one of the most frequent complications. It is well known the anatomical and histological changes in aortopathy are similar to those in aging process. The increase of pulse wave velocity (PWV) enhances pressure wave reflection, and it augments left ventricular afterload and impairs the coronary supply-workload balance in aging. This article reviews the aortic function in patients with CHD, aiming to provide a new direction for the management of their cardiovascular aging process.

Methods

Papers on vascular physiology in CHD were retrieved. I searched all original papers and reviews about the vascular physiology in CHD using PubMed, published from January 1, 1973 to June 30, 2022, in English.

Key Content and Findings

Enhancement of pressure wave reflection has been reported in many CHDs. Although PWV in whole aorta is not necessarily elevated, the abnormal arterial stiffness gradient is common in patients with CHD.

Conclusions

Many reports concerning functional abnormalities of the aorta have been reported. The abnormalities can result in cardiovascular disease and organ damage. The practitioners should carefully treat patients with CHD while paying attention to their aging process.

The direct effect of fibroblast growth factor 23 on vascular smooth muscle cell phenotype and function

BACKGROUND

In chronic kidney disease (CKD) patients, increased levels of fibroblast growth factor 23 (FGF23) are associated with cardiovascular mortality. The relationship between FGF23 and heart hypertrophy has been documented, however, it is not known whether FGF23 has an effect on vasculature. Vascular smooth muscle cells VSMCs may exhibit different phenotypes; our hypothesis is that FGF23 favours a switch from a contractile to synthetic phenotype that may cause vascular dysfunction. Our objective was to determine whether FGF23 may directly control a change in VSMC phenotype.

METHODS

This study includes in vitro, in vivo and ex vivo experiments and evaluation of patients with CKD stages 2-3 studying a relationship between FGF23 and vascular dysfunction.

RESULTS

In vitro studies show that high levels of FGF23, by acting on its specific receptor FGFR1 and Erk1/2, causes a change in the phenotype of VSMCs from contractile to synthetic. This change is mediated by a downregulation of miR-221/222, which augments the expression of MAP3K2 and PAK1. miR-221/222 transfections recovered the contractile phenotype of VSMCs. Infusion of recombinant FGF23 to rats increased vascular wall thickness, with VSMCs showing a synthetic phenotype with a reduction of miR-221 expression. Ex-vivo studies on aortic rings demonstrate also that high FGF23 increases arterial stiffening. In CKD 2-3 patients, elevation of FGF23 was associated with increased pulse wave velocity and reduced plasma levels of miR-221/222.

CONCLUSION

In VSMCs, high levels of FGF23, through the downregulation of miR-221/222, causes a change to a synthetic phenotype. This change in VSMCs increases arterial stiffening and impairs vascular function, which might ultimately worsen cardiovascular disease.

Left ventricular structure and function in patients with chronic kidney disease assessed by 3D echocardiography: the CPH-CKD ECHO study

Cardiovascular disease is the leading cause of mortality amongst patients with chronic kidney disease (CKD). This is the first study using 3-dimensional echocardiography (3DE) to investigate associations between adverse changes of the left ventricle, and different stages of CKD. Participants were recruited from the Copenhagen CKD cohort study and the Herlev-Gentofte CKD cohort study. Patients were stratified according to GFR category (G1 + 2: eGFR ≥ 60 mL/min/1.73 m2, G3: eGFR = 30-59 mL/min/1.73 m2, and G4 + 5: eGFR ≤ 29 mL/min/1.73 m2), and according to albuminuria (A1: UACR < 30 mg/g, A2: 30-300 mg/g, A3: > 300 mg/g). Echocardiograms were analysed for left ventricular (LV) mass index (LVMi), LV ejection fraction (LVEF), and global strain measures. In adjusted analysis, eGFR groups were adjusted for confounders and albuminuria category, while albuminuria groups were adjusted for confounders and GFR category. The study population consisted of 662 outpatients with CKD and 169 controls. Mean age was 57 ± 13 years, and 61% were males. Mean LVEF and global longitudinal strain (GLS) were increasingly impaired across eGFR groups: LVEF = 60.1%, 58.4%, and 57.8% (p = 0.013), GLS =  - 16.1%, - 14.8%, and - 14.6% (p < 0.0001) for G1 + 2, G3, and G4 + 5. LVMi and prevalence of LV hypertrophy increased with albuminuria severity: mean LVMi = 87.9 g/m2, 88.1 g/m2, and 92.1 g/m2 (p = 0.007) from A1-3. Adjusted analysis confirmed reduced LVEF in G3 compared with G1 + 2, and increased LVMi in A3 compared with A1. Increasingly impaired eGFR was associated with adverse changes in LV systolic function, while albuminuria was associated with adverse changes in LV mass assessed by 3DE. Their associations were independent of each other.

A Reproducible Mouse Model of Moderate CKD With Early Manifestations of Osteoblastic Transition of Cardiovascular System

Chronic kidney disease (CKD) is a significant public health challenge with a substantial associated risk of mortality, morbidity, and health care expenditure. Culprits that lead to development and progression of CKD are multifaceted and heterogenous in nature. This notion underscores the need for diversification of animal models to investigate its pathophysiology, related complications, and to subsequently enable discovery of novel therapeutics. Importantly, animal models that could recapitulate complications of CKD in both genders are desperately needed. Cardiovascular disease is the most common cause of death in CKD patients that may be due in part to high prevalence of vascular calcification (VC). Using DBA/2 mice that are susceptible to development of VC, we sought to investigate the feasibility and reproducibility of a unilateral ischemia-reperfusion model followed by contralateral nephrectomy (UIRI/Nx) to induce CKD and its related complications in female and male mice. Our results demonstrate that irrespective of gender, mice faithfully displayed complications of moderate CKD following UIRI/Nx as evidenced by significant rise in serum creatinine, albuminuria, higher degree of collagen deposition, elevated expression of classic fibrotic markers, higher circulating levels of FGF-23, PTH and hepcidin. Moreover, we corroborate the osteoblastic transition of aortic smooth muscle cells and cardiomyocytes based on higher levels of osteoblastic markers namely, Cbfa-1, osteopontin, osteocalcin, and osterix. Our data confirms a viable, and consistent model of moderate CKD and its associated complications in both male and female mice. Furthermore, early evidence of osteoblastic transition of cardiovascular system in this model confirms its suitability for studying and implementing potential preventive and/or therapeutic approaches that are urgently needed in this field.

Central and brachial pulse pressure predicts cardiovascular and renal events in treated hypertensive patients

PURPOSES

Central blood pressure is a stronger predictor of cardiovascular prognosis rather than brachial blood pressure. The reflection wave reaches the abdominal aorta sooner than ascending aorta. Thus, the contribution of central pulse pressure (cPP) to renal events may differ from that of cardiovascular events.

METHODS

The subanalysis of the ABC-J II study was performed. Subjects were 3434 treated hypertensive patients with a mean follow-up of 4.7 years. Left ventricular hypertrophy, an index of cardiovascular risk, correlated with cPP better than central systolic blood pressure in this cohort. The contribution of brachial pulse pressure (bPP) and cPP to cardiovascular and renal events was analysed.

RESULTS

Cox proportional-hazard analysis revealed that sex (p < 0.001), height (p < 0.05), history of cardiovascular diseases (p < 0.001), number of antihypertensive drugs (p < 0.05), and cPP (p < 0.05) contributed to cardiovascular events. However, Cox proportional-hazard analysis disclosed that baseline serum creatinine (p < 0.001) and bPP (p < 0.05) predicted renal events. After adjusting for the history of cardiovascular diseases, Cox regression demonstrated only sex as a significant predictor of cardiovascular events. After adjusting for baseline serum creatinine, no parameters were shown to predict renal events.

CONCLUSIONS

The present findings support our previous data that the absence of cardiovascular or renal diseases is an important determinant for event-free survival, and suggest that cPP and bPP contribute to cardiovascular and renal events in treated hypertensive patients.

Arterial Stiffness, Genetic Risk, and Type 2 Diabetes: A Prospective Cohort Study

OBJECTIVE

We aimed to investigate prospective associations of pulse wave arterial stiffness index (ASI) and pulse pressure (PP) with type 2 diabetes (T2D) and assess the modifying effect of genetics.

RESEARCH DESIGN AND METHODS

We included 152,611 participants free of diabetes and cardiovascular disease in the UK Biobank. All participants had ASI and blood pressure measurements collected at baseline visit. In total, 37 single nucleotide polymorphisms were used to calculate the genetic risk score (GRS) of T2D.

RESULTS

During a median follow-up of 9.5 years, 3,000 participants developed T2D. Per-SD increase in ASI was associated with a 3% higher T2D risk (95% CI 2-4%). The hazard ratio (HR) (95% CI) of T2D was 1.58 (1.39-1.80) in the highest quintile group compared with the lowest quintile group of ASI. However, the association between PP and T2D was nonlinear. Compared with the lowest quintile group, the risk of T2D in higher quintile groups of PP was 0.91 (0.79-1.04), 0.98 (0.86-1.11), 1.15 (1.01-1.30), and 1.24 (1.10-1.41), respectively. Furthermore, we observed an interaction between ASI and genetic susceptibility to T2D, because the elevated HR of T2D associated with high ASI was more evident among participants with higher GRS of T2D (P interaction = 0.008), whereas the interaction between PP and GRS was nonsignificant (P interaction = 0.55).

CONCLUSIONS

ASI was associated with an elevated risk of T2D in a dose-response fashion, whereas PP and T2D showed a nonlinear J-shaped association. Additionally, the association between ASI and T2D was partially strengthened by higher genetic susceptibility to T2D.

Inadequacy of Augmentation Index for Monitoring Arterial Stiffness: Comparison with Arterial Compliance and Other Hemodynamic Variables

PURPOSE

Augmentation Index (AI_x) is used clinically for monitoring both wave reflections and arterial stiffness, which when increased is a risk factor of cardiovascular mortality and morbidity. We hypothesize that AI_x is not solely related to vascular stiffness as described by arterial compliance and other hemodynamic parameters since AI_x underestimates wave reflections.

METHODS

Aortic pressure and flow datasets (n = 42) from mongrel dogs were obtained from our experiments and Mendeley Data under various conditions. Arterial compliances based on the Windkessel model (C_t), the stroke volume (SV) to pulse pressure (PP) ratio (C_v = SV/PP), and at inflection pressure point (C_Pi) were computed. Other relevant hemodynamic factors are also computed.

RESULTS

AI_x was poorly associated with arterial stiffness calculated from C_t (r = 0.299, p = 0.058) or C_Pi (r = 0.203, p = 0.203), even when adjusted for heart rates. C_t and C_v were monotonically associated. Alterations in inflection pressure (P_i) did not follow the changes in pulse pressure (PP) (r = 0.475, p = 0.002), and P_i was quantitatively similar to systolic pressure (r = 0.940, p < 0.001).

CONCLUSION

AI_x is neither linearly correlated with arterial stiffness, nor with arterial compliance and several cardiac and arterial parameters have to be considered when AI_x is calculated.

High prevalence of middle cerebral artery calcification is associated with cardiovascular mortality in hemodialyzed patients: an overlooked part of arterial tree?

PURPOSE

We have analyzed markers of accelerated atherosclerosis like large artery stiffness, ankle-brachial index, carotid and vertebral duplex ultrasonography and their possible associations with the incidence of intracranial calcifications, clinical course of hemodialyzed patients, and cardiovascular mortality.

METHODS

A computed tomographic scan of the head was performed for any neurological indication on 100 hemodialyzed patients. Eleven intracranial arteries were analyzed for calcification score, while internal carotid arteries and vertebral arteries were excluded in cerebral artery calcification score. As a control group for assessing intracranial calcifications, we have analyzed computed tomographic scans from diabetic patients who had an acute stroke.

RESULTS

Deceased patients had significantly higher values of augmentation index and pulse wave velocity, lower ankle-brachial index, and higher internal carotid arteries peak systolic value than survived patients. Deceased patients had significantly higher number of calcified middle cerebral arteries as well as significantly higher intracranial artery calcification score and cerebral artery calcification score. Hemodialyzed patients had significantly higher both intracranial and cerebral artery calcification scores than diabetic control group. Age and calcified middle cerebral arteries had increased HR of 1.08 and 1.36 for cardiovascular mortality.

CONCLUSION

This study showed that large artery stiffness and not the presence of peripheral arterial disease or carotid artery stenosis have the prognostic role of middle cerebral arteries' calcifications and cardiovascular mortality in hemodialyzed patients. The presence of middle cerebral arteries' calcifications diagnosed by a non-invasive method should be considered a marker of middle-sized conduit arteries atherosclerosis, subclinical brain damage, and future fatal cardiovascular events.

Center-To-Periphery Arterial Stiffness Gradient Is Attenuated and/or Reversed in Pregnancy-Associated Hypertension

Background: Non-pregnant (NP) women have a progressive increase in arterial stiffness from central-to-peripheral arteries [“stiffness gradient” (SG)], which is of physiologic importance since excessive pulsatility is filtered by the creation of wave reflections. If the aorta gets stiff with minimal or no change in the periphery, the SG is dissipated transmitting pressure disturbances to the microcirculation. It remains unknown the status of the SG in both women with healthy pregnancies (HP) and complicated by pregnancy-associated hypertension (PAH).

Objective: To determine whether HP and PAH are associated with changes in SG. Secondarily, we aim at identifying potential differences between the subgroups of PAH (pre-eclampsia and gestational hypertension).

Methods: HP (n = 10), PAH (n = 16), and healthy NP women (n = 401, to be matched for age, and cardiovascular risk with the pregnant women) were included. Carotid-to-femoral (cfPWV) and carotid-to-radial pulse wave velocity (crPWV), common carotid artery (CCA) and brachial artery (BA) diameters and elastic modulus (EM), and regional (cfPWV/crPWV or “PWV ratio”) and local (CCA EM/BA EM or “EM ratio”) SG were quantified.

Results: HP showed no changes in PWV ratio compared with NP, in the presence of significantly lower cfPWV and crPWV. HP exhibited higher arterial diameters and lower CCA EM/BA EM compared to NP, without differences with PAH. PAH was associated with a significant increase in the PWV ratio that exceeded the levels of both NP and HP, explained by a lower (although significant) reduction of cfPWV with respect to that observed in HP with respect to NP, and a higher reduction in crPWV with respect to that observed between HP and NP. The blunted reduction in cfPWV observed in PAH coincided with an increase in the CCA EM.

Conclusions: Compared with NP, HP was associated with unchanged PWV ratio but with a reduction in CCA EM/BA EM, in the setting of a generalized drop in arterial stiffness. Compared with NP and HP, PAH was associated with an “exaggerated rise” in the PWV ratio without changes in CCA EM/BA EM, in the setting of a blunt reduction in cfPWV but exaggerated crPWV drop. The SG attenuation/reversal in PAH was mainly driven by pre-eclampsia.

Diabetes mellitus type 2 does not influence carotid stiffness in patients on maintenance hemodialysis

Patients on maintenance hemodialysis are a group with high cardiovascular risk, characterized by high arterial stiffness, which is considered a novel cardiovascular risk factor. Diabetes mellitus is both one of the leading causes of end-stage renal disease and a determinant of poor outcome in this group. The aim of the study was to examine carotid stiffness with high resolution echo-tracking in order to assess the influence of diabetes mellitus on arterial stiffness in this group.

Ninety patients (47 F; 43 M) with end-stage renal disease on maintenance hemodialysis were divided into two subgroups: diabetic and nondiabetic (37 and 53 patients respectively). They underwent clinical examination, laboratory tests, and ultrasonographic carotid stiffness assessment both before and after hemodialysis. Local arterial stiffness parameters β, Ep, AC, and PWVβ were calculated. Patient survival was assessed after a 58-month-long follow-up. During the 58-month period 25 of these diabetic patients died, as did 18 non-diabetic patients. Diabetes mellitus was a risk factor for overall mortality among the group of hemodialysed patients. Patients who died from non-cardiovascular causes significantly more often suffered from diabetes mellitus than survivors. There were no statistically significant differences in local arterial stiffness between the groups.

Local arterial stiffness in hemodialysed patients, assessed with high resolution echo-tracking, is not influenced by the presence of diabetes.

Association between pulse pressure, systolic blood pressure and the risk of rapid decline of kidney function among general population without hypertension: results from the China health and retirement longitudinal study (CHARLS)

BACKGROUND

Association between blood pressure (BP) and kidney function among the middle and old aged general population without hypertension remains unclear.

METHODS

Participants aged ≥ 45 years, with complete data in 2011 and 2015 interviews of the China Health and Retirement Longitudinal Study(CHARLS), and without pre-existing hypertension were included. Systolic BP (SBP) was categorized as low (< 120 mmHg), medium (120-129 mmHg), and high (120-139 mmHg). Diastolic BP (DBP) was categorized as low (< 60 mmHg), medium (60-74 mmHg), and high (75-89 mmHg). Pulse pressure (PP) was categorized as normal (< 60 mmHg) and high (≥ 60 mmHg). The outcome was defined as rapid decline of estimated glomerular filtration rate(eGFR, decline ≥ 4 ml/min/1.73 m2/year). BP combination was designed according to the category of SBP and PP. The association between BP components, types of BP combination, and the risk of rapid decline of eGFR was analyzed using multivariate logistic regression models, respectively. Age-stratified analyses were conducted.

RESULTS

Of 4,534 participants included, 695(15.3%) individuals were recognized as having rapid decline of eGFR. High PP[odds ratio(OR) = 1.34, 95%confidence interval(CI) 1.02-1.75], low SBP (OR = 1.28, 95%CI 1.03-1.59), and high SBP (OR = 1.32, 95% CI 1.02-1.71) were significantly associated with the risk of eGFR decline. Low SBP were associated with 65% increment of the risk of eGFR decline among participants aged < 55 years. The combination of high SBP and high PP (OR = 1.79, 95% CI 1.27-2.54) and the combination of low SBP and high PP (OR = 3.07, 95% CI 1.24-7.58) were associated with the increased risk of eGFR decline among the middle and old aged general population.

CONCLUSION

Single and combination of high PP and high SBP could be the risk indicators of eGFR decline among the middle and old aged general population.

Chronic Kidney Disease and Arterial Stiffness: A Two-Way Path

The kidney-heart relationship has raised interest for the medical population since its vast and complex interaction significantly impacts health. Chronic kidney disease (CKD) generates vascular structure and function changes, with significant hemodynamic effects. The early arterial stiffening in CKD patients is a consequence of the interaction between oxidative stress and chronic vascular inflammation, leading to an accelerated deterioration of left ventricular function and alteration in tissue perfusion. CKD amplifies the inflammatory cascade's activation and is responsible for altering the endothelium function, increasing the vascular tone, wall thickening, and favors calcium deposits in the arterial wall. Simultaneously, the autonomic imbalance, and alteration in other hormonal systems, also favor the overactivation of inflammatory and fibrotic mediators. Thus, hormonal disarrangement also contributes to structural and functional lesions throughout the arterial wall. On the other hand, a rise in arterial stiffening and volume overload generates high left ventricular afterload. It increases the left ventricular burden with consequent myocardial remodeling, development of left ventricular hypertrophy and, in turn, heart failure. It is noteworthy that reduction in glomerular mass of renal diseases generates a compensatory glomerular filtration overdriven associated with large-arteries stiffness and high cardiovascular events. Furthermore, we consider that the consequent alterations of the arterial system's mechanical properties are crucial for altering tissue perfusion, mainly in low resistance. Thus, increasing the knowledge of these processes may help the reader to integrate them from a pathophysiological perspective, providing a comprehensive idea of this two-way path between arterial stiffness and renal dysfunction and their impact at the cardiovascular level.

The Novel Bone Alkaline Phosphatase Isoform B1x Is Associated with Improved 5-Year Survival in Chronic Kidney Disease

Circulating alkaline phosphatase (ALP) is an independent cardiovascular risk marker. Serum bone ALP (BALP) isoforms indicate bone turnover and comprise approximately 50% of total circulating ALP. In chronic kidney disease (CKD), mortality is highest in patients with increased ALP and BALP and low bone turnover. However, not all low bone turnover states are associated with increased mortality. Chronic inflammation and oxidative stress, features of protein energy wasting syndrome, induce cardiovascular BALP activity and fibro-calcification, while bone turnover is suppressed. Circulating BALP isoform B1x is associated with low ALP and low bone turnover and has been exclusively detected in CKD. We investigated the association of serum B1x with survival, abdominal aortic calcification (AAC) score, and aortic pulse wave velocity (PWV) in CKD. Serum ALP, BALP isoforms, parathyroid hormone (PTH), PWV, and AAC were measured repeatedly over 2 years in 68 prevalent dialysis patients. Mortality was assessed after 5 years. B1x was detected in 53 patients. A competing risk analysis revealed an association of B1x with improved 5-year survival; whereas, baseline PWV, but not AAC score, predicted mortality. However, PWV improved in 26 patients (53%), and B1x was associated with variation of PWV over time (p = 0.03). Patients with B1x had lower PTH and total ALP, suggesting an association with lower bone turnover. In conclusion, B1x is associated with time-varying PWV, lower circulating ALP, and improved survival in CKD, and thus may be an indicator of a reduced cardiovascular risk profile among patients with low bone turnover.

Association between pulse pressure and progression of chronic kidney disease

The aim of this study was to investigate the association between pulse pressure (PP) and chronic kidney disease (CKD) progression among the general population in Japan. We conducted a population-based cohort study of the residents of Iki Island, Nagasaki, Japan, from 2008 to 2018. We identified 1042 participants who had CKD (estimated glomerular filtration rate(eGFR) < 60 mL/min/1.73 m2 or the presence of proteinuria) at baseline. Cox's proportional hazard model was used to evaluate the association between PP and progression of CKD. During a 4.66-year mean follow-up, there were 241 cases of CKD progression (incident rate: 49.8 per 1000 person-years). A significant increase existed in CKD progression per 10 mmHg of PP elevation, even when adjusted for confounding factors [adjusted hazard ratio 1.17 (1.06-1.29) p < 0.001]. Similar results were obtained even after dividing PP into quartiles [Q2: 1.14 (0.74-1.76), Q3: 1.35 (0.88-2.06), Q4: 1.87 (1.23-2.83) p = 0.003 for trend]. This trend did not change significantly irrespective of baseline systolic or diastolic blood pressures. PP remained a potential predictive marker, especially for eGFR decline. In conclusion, we found a significant association between PP and CKD progression. PP might be a potential predictive marker for CKD progression.

Different circadian patterns of arterial stiffness are responsible for increased cardiovascular mortality in hemodialyzed patients

We hypothesized that volume changes during 48-h are associated with different circadian patterns of arterial stiffness on non-dialysis day compared to dialysis day and that the night-time increase of arterial stiffness is associated with higher mortality. The patients whose night-time mean pulse wave velocity levels drop or rise more than 0.5 m/s compared with the day-time period were defined as pulse wave velocity dippers and risers. The patients whose night-time mean augmentation index drop or rise more than 10% compared with the day-time period were defined as augmentation index dippers and risers. There was significantly higher number of patients with dipping and rising pattern of augmentation index and pulse wave velocity on non-dialysis day when compared to dialysis day. On the non-dialysis day both nocturnal augmentation index and pulse wave velocity levels were higher in deceased group with significantly higher number of augmentation index and pulse wave velocity dippers when compared to survived patients. In the linear regression model, the strongest association of survival was with augmentation index and pulse wave velocity risers on the non-dialysis day. On logistic regression only pulse wave velocity rising pattern on non-dialysis day had increased HR of 1.78 for cardiovascular mortality. The present study is the first which analyzed circadian patterns of arterial stiffness in patients on hemodialysis and compared their impact on cardiovascular mortality. A significantly greater number of patients had an augmentation index and pulse wave velocity rising pattern in the deceased group compared to the survived group of patients. Survival had the strongest association with augmentation index and pulse wave velocity risers on the non-dialysis day.

Aortic Root Dilatation Is Attenuated with Diabetes but Is Not Associated with Renal Progression in Chronic Kidney Disease

Patients with chronic kidney disease (CKD) often have cardiac functional and structural abnormalities which can lead to adverse cardiovascular outcomes. In this study, we investigated associations between diabetes mellitus (DM) and cardiac functional and structural parameters in patients with CKD focusing on aortic root diameter (ARD). We also investigated associations of renal outcomes with DM and cardiac functional and structural characteristics. We enrolled 419 patients with CKD stage 3–5 were enrolled. ARD was normalized to body surface area (BSA) (ARD/BSA), and the rate of decline in renal function was assessed by the estimated glomerular filtration rate (eGFR) slope (mL/min/1.73 m²/year). ARD/BSA ≥2.1 cm/m² in men or ≥2.2 cm/m² in women was defined as indicating aortic root dilatation. The patients with DM had lower ARD/BSA, higher left atrial dimension (LAD), lower left ventricular ejection fraction, lower ratio of peak early transmitral filling wave velocity to peak late transmitral filling wave velocity, and higher left ventricular relative wall thickness, than those without DM. After multivariable analysis, DM (vs. non-DM; coefficient β, −0.060; p = 0.018) was significantly associated with low ARD/BSA. Significantly fewer patients with DM had aortic root dilatation compared to those without DM (14.3% vs. 23.1%, p = 0.022). In the patients with DM, there were significant associations between a high left ventricular mass index (LVMI) (per 1 g/m², β, −0.016; p = 0.040) and high LAD (per 1 cm; β, −1.965; p < 0.001) with a low eGFR slope. However, other parameters, including ARD/BSA, were not associated with eGFR slope. Furthermore, there were no associations between eGFR slope and any of the echocardiographic parameters in the patients without DM. Aortic root dilatation was attenuated in the patients with DM, but it was not associated with a decline in renal function. However, high LAD and LVMI were associated with rapid renal function decline in the CKD patients with DM.

Can Aortic and Renal Arteries Calcium Scores Be New Factors to Predict Post-Operative Renal Function After Nephron Sparing Surgery?

INTRODUCTION

This study aims to investigate whether the calcification of renal arteries and aorta may be risk factors for developing chronic kidney disease (CKD) after Nephron sparing surgery (NSS).

MATERIALS AND METHODS

The patients that underwent either open or laparoscopic NSS from 2000 to 2019 in 4 different centers were retrospectively assessed. Of these patients, 328 had a non-contrast-enhanced computer tomography. Calcium scores of the renal arteries and abdominal aorta were measured in the non-contrast-enhanced images with the calcium score plugin (version 2.0) of Horos™. Univariate and multivariate logistic regression analysis was performed to determine significant risk factors for developing CKD at the last check-up. Roc curve analysis was performed to determine the optimal cut-off values of age and abdominal aorta calcium scores.

RESULTS

A total of 302 patients, of which 52 (16,6%) with CKD and 252 (83,4%) without CKD at the last check-up, were included in the analysis. The mean warm ischemia duration was significantly higher in patients with CKD (18,79±6,72 vs 16,38±5,57 minutes, p=0,016). The mean size of the tumor diameter and the number of the patients with ≥stage T1b were higher in the group with CKD (p=0,024 and 0,005, respectively). The median calcium scores of the aorta and renal arteries were higher in the group with CKD (p<0,001 and p<0,001, respectively). In multivariate analysis, age >60 years (OR:3,65, p=0,022), calcium score of the aorta (OR:4,07, p=0,029), tumor diameter (OR:1,03, p=0,026) and pre-operative CKD stage (OR:10,13, p<0,001) found the be significant factors for predicting last check-up CKD.

CONCLUSION

The calcium score of the aorta may be used as an additional risk factor to predict post-operative CKD risk after NSS with sensitivity over 80%.

Degradation of Premature-miR-181b by the Translin/Trax RNase Increases Vascular Smooth Muscle Cell Stiffness

[Figure: see text].

Narrative Review of Carotid disease and the kidney

Patients with chronic kidney disease (CKD) have an increased cardiovascular (CV) risk that is only in part explained by established risk factors. Carotid arteriosclerosis and atherosclerosis are increased in CKD, play a role in the causation of CV disease in these patients and can affect the progression of renal disease. The arterial stiffening process is evident even in CKD patients with a very mild reduction of glomerular filtration rate (GFR) whereas arterial thickening is evident in more advanced stages. Possible mechanisms include functional and structural alterations of the arterial wall. Arterial stiffness can mediate the effect of CKD on target organs (i.e., brain, kidney and heart). In this review we discuss the arterial phenotype of patients with CKD. This is characterized by increased common carotid artery stiffness and outward remodeling (enlargement and thickening of the arterial wall) and a normal/reduced stiffness paired with an inward remodeling (narrowing of the arterial wall) of muscular arteries. We also discuss the consequences of carotid dysfunction, including the involvement of large elastic arteries stiffness on ventricular-vascular coupling, the mechanisms linking carotid stiffening and increased cardio- and cerebrovascular risk in CKD patients, and the therapeutic options to improve carotid function.

Cardiorespiratory fitness assessed by cardiopulmonary exercise testing between different stages of pre-dialysis chronic kidney disease: A systematic review and meta-analysis

AIM

The burden of several cardiovascular risk factors increases in parallel to renal function decline. Exercise intolerance is common in patients with chronic kidney disease (CKD) and has been associated with increased risk of adverse outcomes. Whether indices of cardiorespiratory capacity deteriorate with advancing CKD stages is unknown.

METHODS

We conducted a systematic review and meta-analysis of studies assessing cardiorespiratory capacity in adult patients with pre-dialysis CKD using cardiopulmonary exercise testing (CPET) and reporting data for different stages. Our primary outcome was differences in peak oxygen uptake (VO₂ peak) between patients with CKD Stages 2-3a and those with Stages 3b-5(pre-dialysis). Literature search was undertaken in PubMed, Web of Science and Scopus databases, and abstract books of relevant meetings. Quality assessment was undertaken with Newcastle-Ottawa-Scale.

RESULTS

From 4944 records initially retrieved, six studies with 512 participants fulfilling our inclusion criteria were included in the primary meta-analysis. Peak oxygen uptake (VO₂ peak) was significantly higher in patients with CKD Stages 2-3a versus those with Stages 3b-5(pre-dialysis) [weighted-mean-difference, WMD: 2.46, 95% CI (1.15, 3.78)]. Oxygen consumption at ventilatory threshold (VO₂ VT) was higher in Stages 2-3a compared with those in Stages 3b-5(pre-dialysis) [standardized-mean-difference, SMD: 0.59, 95% CI (0.06, 1.1)], while no differences were observed for maximum workload and respiratory-exchange-ratio. A secondary analysis comparing patients with CKD Stages 2-3b and Stages 4-5(pre-dialysis), yielded similar results [WMD: 1.78, 95% CI (1.34, 2.22)]. Sensitivity analysis confirmed the robustness of these findings.

CONCLUSION

VO₂ peak and VO₂ VT assessed with CPET are significantly lower in patients in CKD Stages 3b-5 compared with Stages 2-3a. Reduced cardiorespiratory fitness may be another factor contributing to cardiovascular risk increase with advancing CKD.

Renal Dysfunction Is Associated with Middle Cerebral Artery Pulsatility Index and Total Burden of Cerebral Small Vessel Disease

BACKGROUND AND PURPOSE

Renal dysfunction is known to affect vasculature and lead to systemic arterial stiffness. It also independently increases the risk of cerebral small vessel disease (cSVD) and stroke. We aimed to examine the effect of renal dysfunction on cerebral hemodynamics and the burden of cSVD.

METHODS

Of the 412 patients admitted to Seoul National University Hospital, between May 2015 and 2019, with lacunar infarction and no major intracranial arterial stenosis observed on magnetic resonance angiography, we included 283 patients who had undergone a transcranial Doppler (TCD) ultrasound after 72 h of stroke onset. The patients were divided into renal dysfunction (estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m2 at admission) and control (eGFR ≥60 mL/min/1.73 m2) groups. We investigated the correlations between renal function, the pulsatility index (PI), and the total MRI burden of cSVD. Furthermore, multivariate analysis was performed to assess the association between renal dysfunction and the PI of the middle cerebral artery (MCA) measured through TCD ultrasound.

RESULTS

Among the total patients, 74 (26.1%) had renal dysfunction (eGFR <60 mL/min/1.73 m2 at admission). Patients with renal dysfunction were significantly older, showed higher pulse pressure, and had a higher prevalence of hypertension, diabetes mellitus, and coronary artery disease. Renal dysfunction was significantly associated with higher distal cerebrovascular flow resistance (median PI 1.12, interquartile range [IQR]: 0.85-1.57 vs. controls 0.84, IQR: 0.54-1.22; p < 0.001). Also, patients with renal dysfunction had a significantly higher total MRI burden of cSVD (median cSVD score 2, IQR: 1-3 vs. controls median score 1, IQR: 0-2; p < 0.001). There was an inverse proportional relationship between the PI and eGFR. Finally, multivariate analysis showed renal dysfunction (adjusted odds ratio: 4.516, 95% confidence interval: 1.051-20.292) and older age (adjusted odds ratio: 1.076, 95% confidence interval: 1.038-1.114) as independent predictors of a high PI.

CONCLUSIONS

Renal dysfunction is independently associated with a high PI of MCA. Renal dysfunction leads to systemic arterial stiffness including stiffness in cerebral arteries, thus increasing the burden of cSVD. Therefore, noninvasive screening for high PI by TCD in kidney failure patients might be helpful.

The aortic-femoral arterial stiffness gradient: an atherosclerosis risk in communities (ARIC) study

BACKGROUND

The aortic to femoral arterial stiffness gradient (af-SG) may be a novel measure of arterial health and cardiovascular disease (CVD) risk, but its association with CVD risk factors and CVD status, and whether or not they differ from the referent measure, carotid-femoral pulse-wave velocity (cfPWV), is not known.

METHOD

Accordingly, we compared the associations of the af-SG and cfPWV with (i) age and traditional CVD risk factors and (ii) CVD status. We evaluated 4183 older-aged (75.2 ± 5.0 years) men and women in the community-based Atherosclerosis Risk in Communities (ARIC) Study. cfPWV and femoral-ankle PWV (faPWV) were measured using an automated cardiovascular screening device. The af-SG was calculated as faPWV divided by cfPWV. Associations of af-SG and cfPWV with age, CVD risk factors (age, BMI, blood pressure, heart rate, glucose and blood lipid levels) and CVD status (hypertension, diabetes, coronary heart disease, heart failure, stroke) were determined using linear and logistic regression analyses.

RESULTS

(i) the af-SG and cfPWV demonstrated comparable associations with age and CVD risk factors, except BMI. (ii) a low af-SG was associated with diabetes, coronary heart disease, heart failure and stroke, whilst a high cfPWV was only associated with diabetes.

CONCLUSION

Although future studies are necessary to confirm clinical utility, the af-SG is a promising tool that may provide a unique picture of hemodynamic integration and identification of CVD risk when compared with cfPWV.

Renal hemodynamics across the adult lifespan: Relevance of flow pulsatility to chronic kidney disease

BACKGROUND

Elevated renal flow pulsatility may contribute to the pathogenesis of chronic kidney disease (CKD). The purpose of this study was to investigate the associations among age, renal flow pulsatility, and CKD biomarkers in non-CKD adults and CKD patients.

METHODS

Non-CKD adults (n = 415) and CKD patients (n = 136) aged between 22 and 83 years underwent the renal blood flow measurement using duplex ultrasonography. Pulsatility index (PI) and resistive index (RI) were calculated to assess renal flow pulsatility. The CKD biomarkers such as urinary liver-type fatty acid-binding protein (L-FABP) and serum fibroblast growth factor 23 (FGF23) were measured from each participant. Aortic hemodynamic parameters were measured by applanation tonometry.

RESULTS

In non-CKD adults, advancing age was associated with elevations of renal PI and RI which slowly increased during middle-aged (PI: β = 0.14, RI: β = 0.17) and accelerated in older adults (PI: β = 0.34, RI: β = 0.33). In CKD patients, age-related increases in renal PI and RI were observed only in the middle age group (PI: β = 0.23, RI: β = 0.26). Multivariate analysis demonstrated that renal PI and RI were independently associated with CKD biomarkers, including urinary L-FABP and serum FGF23, and aortic pulse pressure.

CONCLUSIONS

Advancing age is associated with a progressive elevation of renal flow pulsatility which manifests during middle age and accelerates in later life. Moreover, elevated renal flow pulsatility is associated with the presence of CKD in each age group and also with biomarker levels that reflect CKD progression.

The association between Hba1c and arterial stiffness among non-diabetic patients with chronic kidney disease

Background

Cardiovascular events are seen more frequently after the age of 60 and they are a significant cause of morbidity and mortality. Arterial stiffness is a property that can be expressed by pulse wave velocity and this value is assumed to be a predictor of cardiovascular events. Patients with chronic kidney disease and dysregulated blood sugar have increased atherosclerosis and arterial stiffness, but the relationship between physiological levels of Hba1c and arterial stiffness is less clear in chronic kidney disease patients without diabetes mellitus.

Objectives

Here, we aimed to investigate the degree of arterial stiffness among non-diabetic, non-dialysis dependent chronic kidney disease patients with physiological HbA1c levels.

Methods

We enrolled 51 patients who were followed up at Ege University Hospital Nephrology Department between February and June 2015. Non-diabetic, non-dialysis dependent chronic kidney disease patients were included in the study. Blood pressure and pulse wave velocity were measured with an applanation tonometry device (Sphygmocor Vx Software Atcor Medical, Australia). Correlations between pulse wave velocity and the aforementioned parameters were investigated (see below).

Results

We detected a significant correlation between pulse wave velocity and systolic blood pressure (p=0.0001) and Hba1c (p=0.044) separately. There was an inverse correlation with creatinine clearance (p=0.04). We also detected a significant correlation with serum phosphorus level (p=0.0077) and furosemide use (p=0.014). No correlations were found among the other parameters.

Conclusions

Arterial stiffness is an important predictor of cardiovascular events and measuring it is an inexpensive method for estimating morbidity and mortality. Our study supports the importance of measuring arterial stiffness and of controlling blood glucose levels, even at physiological Hba1c values, especially for chronic kidney disease patients.

Pulse Wave Velocity Assessment for Cardiovascular Risk Prognostication in ESKD: Weighting Recent Evidence

BACKGROUND

Among patients with end-stage kidney disease (ESKD), arterial stiffness is considered as a powerful predictor of cardiovascular (CV) morbidity and mortality. However, the relevance of aortic pulse wave velocity (PWV) as a prognostic biomarker for CV risk estimation is not yet fully clear.

METHODS

We performed a systematic search of Medline/PubMed database from inception through August 21, 2019 to identify observational cohort studies conducted in ESKD patients and exploring the association of PWV with CV events and mortality.

RESULTS

Whereas "historical" cohort studies showed aortic PWV to be associated with higher risk of CV and all-cause mortality, recent studies failed to reproduce the independent predictive value of aortic PWV in older ESKD patients. Studies using state-of-the-art prognostic tests showed that the addition of aortic PWV to standard clinical risk scores could only modestly improve CV risk reclassification. Studies associating improvement in PWV in response to blood pressure (BP)-lowering with improvement in survival cannot demonstrate direct cause-and-effect associations due to their observational design and absence of accurate methodology to assess the BP burden.

CONCLUSION

Despite the strong pathophysiological relevance of arterial stiffness as a mediator of CV disease in ESKD, the assessment of aortic PWV for CV risk stratification in this population appears to be of limited value. Whether aortic PWV assessment is valuable in guiding CV risk factor management and whether such a therapeutic approach is translated into improvement in clinical outcomes, is an issue of clinical relevance that warrants investigation in properly-designed randomized trials.