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

Association between Chronic Kidney Disease and Sudden Sensorineural Hearing Loss: A Longitudinal Follow-Up Studies Using ICD-10 Codes in a National Health Screening Cohort

This study aims to investigate the association between chronic kidney disease (CKD) and sudden sensorineural hearing loss (SSNHL) using a population-based cohort study. We used data from the Korean National Health Insurance Service-Health Screening Cohort. Participants were selected based on diagnosis and treatment codes, and CKD participants were 1:4 matched with control participants. Covariates, including demographic and lifestyle factors, and comorbidities were considered in the analysis. We calculated the incidence rate and hazards ratio of SSNHL. A total of 16,713 CKD participants and 66,852 matched controls were enrolled. The CKD group had a higher incidence rate of SSNHL compared to the control group at 2.16 and 1.74 per 1000 person-years, respectively. The CKD group exhibited a higher risk for SSNHL compared to the control group with adjusted HR 1.21. In the subgroup analysis, the presence of cardiovascular risk factors was associated with a diminished effect of CKD on the risk of developing SSNHL. This study provides strong evidence of an association between CKD per se and an increased risk of SSNHL even after adjusting for various demographic and comorbidity factors. The findings suggest that CKD patients may require more comprehensive monitoring for hearing loss.

Effect of Congenital or Acquired Renal Mass Reduction on Arterial Stiffness

BACKGROUND

The changes in kidney functions, adversely affect the cardiovascular system. The aim of this study was to investigate whether arterial stiffness (AS), an indicator of subclinical atherosclerosis, was affected in patients with congenital or acquired reduced renal mass.

METHODS

In this prospective study, a total 135 patients (mean age 43.4±8.5 years and 71.9% female) with congenital unilateral small/non-functioning kidney or unilateral agenesis or with unilateral nephrectomy were included. As control group, 44 healthy individuals with similar age and gender (mean age, 42.5±7.1 year and 61.4% female) were included. Estimated glomerular filtration rate (eGFR) was calculated by Modification of Diet in Renal Disease formula. Official blood pressures (BP) and 24-h ambulatory non-invasive BP of both groups were measured. AS was assessed with pulse wave velocity (PWV) by using Mobile-O-Graph NG arteriograph device using oscillometrical method.

RESULTS

There was no difference in terms of BP parameters and body mass index between groups. eGFR values of control group and study group were 93±19ml/min/1.73m² and 89±28ml/min/1.73m², respectively (p=0.379). Compared with control group, the study group had higher PWV values (6.72±1.11m/sec vs 6.29±0.75m/sec, p=0.018). In linear regression analysis, PWV was found to be correlated with age (β=0.752, p<0.001), and daytime ambulatory systolic BP (β=0.345, p<0.001).

CONCLUSION

Our study showed that AS was increased in patients with reduced renal mass and this increase in AS was related to age and systolic BP. No relation was determined between AS and eGFR. This article is protected by copyright. All rights reserved.

Histology-Verified Intracranial Artery Calcification and Its Clinical Relevance With Cerebrovascular Disease

Intracranial artery calcification (IAC) was regarded as a proxy for intracranial atherosclerosis (ICAS). IAC could be easily detected on routine computer tomography (CT), which was neglected by clinicians in the previous years. The evolution of advanced imaging technologies, especially vessel wall scanning using high resolution-magnetic resonance imaging (HR-MRI), has aroused the interest of researchers to further explore the characteristics and clinical impacts of IAC. Recent histological evidence acquired from the human cerebral artery specimens demonstrated that IAC could mainly involve two layers: the intima and the media. Accumulating evidence from histological and clinical imaging studies verified that intimal calcification is more associated with ICAS, while medial calcification, especially the internal elastic lamina, contributes to arterial stiffness rather than ICAS. Considering the highly improved abilities of novel imaging technologies in differentiating intimal and medial calcification within the large intracranial arteries, this review aimed to describe the histological and imaging features of two types of IAC, as well as the risk factors, the hemodynamic influences, and other clinical impacts of IAC occurring in intimal or media layers.

Carotid Artery Calcification: What We Know So Far

Carotid artery calcification (CAC) is a well-known marker of atherosclerosis and is linked to a high rate of morbidity and mortality. CAC is divided into two types: intimal and medial calcifications, each with its own set of risk factors. Vascular calcification is now understood to be an active, enzymatically regulated process involving dystrophic calcification and endothelial dysfunction at an early stage. This causes a pathogenic inflammatory response, resulting in calcium phosphate deposition in the form of microcalcifications, which causes plaque formation, ultimately becoming unstable with sequelae of complications. If the inflammation goes away, hydroxyapatite crystal formation takes over, resulting in macro-calcifications that help to keep the plaque stable. As CAC can be asymptomatic, it is critical to identify it early using diagnostic imaging. The carotid artery calcification score is calculated using computed tomography angiography (CTA), which is a confirmatory test that enables the examination of plaque composition and computation of the carotid artery calcification score. Magnetic resonance angiography (MRA), which is sensitive as CTA, duplex ultrasound (DUS), positron emission tomography, and computed tomography (PET-CT) imaging with (18) F-Sodium Fluoride, and Optical Coherence Tomography (OCT) are some of the other diagnostic imaging modalities used. The current therapeutic method starts with the best medical care and is advised for all CAC patients. Carotid endarterectomy and carotid stenting are two treatment options that have mixed results in terms of effectiveness and safety. When patient age and anatomy, operator expertise, and surgical risk are all considered, the agreement is that both techniques are equally beneficial.

Association between Periodontitis and Carotid Artery Calcification: A Systematic Review and Meta-Analysis

Recent studies have supported the relationship between periodontitis and carotid artery calcification (CAC), but still uncertain. This systematic review is aimed at evaluating the association between periodontitis and CAC. The search was conducted in four electronic databases: PubMed, EMBASE, Web of Science, and The Cochrane Library, supplemented by checking references of included articles and related review articles. Eligibility assessment and data extraction were conducted independently. The quality assessment and publication bias analysis were performed. The association between periodontitis and CAC was presented in odd ratio (OR) with 95% confidence interval (CI). Additional outcomes included the percentage of alveolar bone loss in CAC versus non-CAC. Twelve studies were included, and 10 were performed quantity analysis. Periodontitis with secure definition (OR = 2.02, 95%CI = 1.18 - 3.45) and insecure definition (OR = 10.78, 95%CI = 4.41 - 26.34) was associated with CAC. And a higher average percentage of alveolar bone loss (weighted mean difference = 10.84%; 95%CI = 6.40 - 15.48) was also observed in CAC patients compared to non-CAC patients. No significant publication bias was found. The results of this systematic review and meta-analysis revealed a significant relationship between periodontitis and CAC.

Positive Associations between Adipocyte Fatty Acid-Binding Protein Level and Central Arterial Stiffness in Peritoneal Dialysis Patients

Background

Adipocyte fatty acid-binding protein (A-FABP) plays essential roles in lipolysis, insulin resistance, and atherosclerosis. This study aimed to evaluate the relationship between serum A-FABP levels and carotid-femoral pulse wave velocity (cfPWV) in peritoneal dialysis (PD) patients.

Methods

This study obtained fasting blood samples from 76 PD patients. A validated tonometry system was used to measure cfPWV. Patients with cfPWV values >10 m/s were classified into the high arterial stiffness group, whereas patients with values ≤10 m/s were classified into the low arterial stiffness group, according to the ESH-ESC 2013 guidelines. Serum A-FABP levels were measured using a commercial enzyme-linked immunosorbent assay kit.

Results

Twenty-five (32.9%) of the 76 PD patients were classified in the high arterial stiffness group. Compared with the patients in the low arterial stiffness group, the high arterial stiffness group was older (P = 0.002) and had a longer PD vintage (P = 0.011), higher diastolic blood pressure (DBP, P = 0.036), higher fasting glucose levels (P = 0.012), higher serum C reactive protein levels (P = 0.001), and higher serum A-FABP levels (P < 0.001). A multivariate logistic regression analysis of the factors significantly associated with central arterial stiffness revealed that A-FABP (odds ratio (OR): 1.165, 95% confidence interval (CI): 1.056–1.284, P = 0.002), age (OR: 1.423, 95% CI: 1.153–1.757, P = 0.001), PD vintage (OR: 1.049, 95% CI: 1.015–1.085, P = 0.005), and DBP (OR: 1.152, 95% CI: 1.033–1.285, P = 0.011) were independent predictors of central arterial stiffness in PD patients. Furthermore, serum A-FABP levels (β = 0.476, adjusted R² change: 0.197, P < 0.001) were significantly positively correlated with cfPWV according to the multivariable forward stepwise linear regression analysis.

Conclusions

A-FABP levels are an independent marker of central arterial stiffness in PD patients.

Blood Pressure Variability and Outcomes in End-Stage Renal Disease Patients on Dialysis: A Systematic Review and Meta-Analysis

Objective: Previous studies have suggested that blood pressure variability (BPV) is associated with an increased risk of mortality and cardiovascular events in patients on dialysis. However, the results are inconsistent. A comprehensive literature review was conducted to analyze the association between BPV and outcomes in patients on dialysis. Methods: Articles in Embase, Medline, and Web of Science from the date of inception through January 1, 2020, were identified. The outcomes were all-cause and cardiovascular mortality and cardiovascular events. The risk of bias was assessed using the Newcastle-Ottawa scale tool. Random effects models were used to pool the overall effect sizes. Two reviewers extracted the data independently. Meta-regression and subgroup analyses were performed to explore potential heterogeneity. Results: Fifteen eligible studies were included, and all enrolled hemodialysis recipients only. The overall risk of bias for the included studies was low. A 1-SD increase in systolic BPV was associated with higher risks of all-cause mortality (HR = 1.18; 95% CI 1.11–1.26, I2 = 53.8%), cardiovascular mortality (HR = 1.23; 95% CI 1.10–1.37, I2 = 57.2%), and cardiovascular events (HR = 1.27; 95% CI 1.07–1.51, I2 = 69.3%). Likewise, a 1-SD increase in diastolic BPV was associated with higher HR for all-cause and cardiovascular mortality (HR = 1.14; 95% CI 1.05–1.23, I2 = 0.0%, and HR = 1.14; 95% CI 0.94–1.38, I2 = 0.0%, respectively). Conclusions: A greater BPV is associated with higher risks of cardiovascular and mortality outcomes in patients on hemodialysis. Further research is required to determine whether BPV may be useful either as a marker enabling individualized treatment of cardiovascular risk or as a treatment target in its own right.

Impaired coronary microcirculation is associated with left ventricular diastolic dysfunction in end-stage chronic kidney disease patients

INTRODUCTION

Coronary vascular dysfunction, as assessed by coronary flow reserve (CFR) in the left anterior descending coronary artery, is found in various conditions including end-stage chronic kidney disease (CKD). Currently, we investigated the associations of CFR with echocardiographic indices of systolic and diastolic cardiac function and identified independent predictors of CFR in hemodialysis patients.

METHODS

End-stage CKD patients treated with hemodialysis (n = 29) without known cardiovascular disease were recruited from a Hemodialysis Unit in Northwestern Greece. A thorough echocardiographic evaluation including CFR measurement following dipyridamole infusion was performed in all participants. Arterial stiffness was assessed by measurement of carotid-femoral pulse wave velocity and aortic augmentation index.

RESULTS

The mean age of the patients was 63 years, and mean duration of hemodialysis was 2.9 years. CFR was 1.60 ± 0.37 while dipyridamole caused a significant increase in E'_sep , S_lat , E'_lat , and Stroke volume (P < .05 for all). Independent predictors of CFR were posterior wall thickness (B -0.408, P = .013) and dipyridamole-induced changes in Tei index (B -0.425, P = .007). A severely decreased CFR < 1.5 was observed in 52% of the patients. E/E' ratio (B 10.84, P = .014) was the single independent predictor of severely decreased CFR.

CONCLUSIONS

In end-stage CKD patients on hemodialysis without known cardiovascular disease, impaired coronary vascular function was prevalent and related to increased left ventricular wall thickness, increased filling pressures, and dipyridamole-induced deteriorated myocardial function independently of the presence of wall-motion abnormalities. Further studies are required to clarify the prognostic role of dipyridamole-induced cardiac changes in hemodialysis patients.

Ferritin in Kidney and Vascular Related Diseases: Novel Roles for an Old Player

Iron is at the forefront of a number of pivotal biological processes due to its ability to readily accept and donate electrons. However, this property may also catalyze the generation of free radicals with ensuing cellular and tissue toxicity. Accordingly, throughout evolution numerous pathways and proteins have evolved to minimize the potential hazardous effects of iron cations and yet allow for readily available iron cations in a wide variety of fundamental metabolic processes. One of the extensively studied proteins in the context of systemic and cellular iron metabolisms is ferritin. While clinicians utilize serum ferritin to monitor body iron stores and inflammation, it is important to note that the vast majority of ferritin is located intracellularly. Intracellular ferritin is made of two different subunits (heavy and light chain) and plays an imperative role as a safe iron depot. In the past couple of decades our understanding of ferritin biology has remarkably improved. Additionally, a significant body of evidence has emerged describing the significance of the kidney in iron trafficking and homeostasis. Here, we briefly discuss some of the most important findings that relate to the role of iron and ferritin heavy chain in the context of kidney-related diseases and, in particular, vascular calcification, which is a frequent complication of chronic kidney disease.

Arterial stiffness may predict renal and cardiovascular prognosis in autosomal-dominant polycystic kidney disease

Background and aims

Autosomal-dominant polycystic kidney disease (ADPKD) is one of the most common causes of end-stage renal disease (ESRD). The most important cause of death among ADPKD patients is cardiovascular (CV). The aim of this study was to examine the prognostic significance of arterial stiffness on CV and renal outcomes in ADPKD.

Methods

A total of 55 patients with ADPKD were examined. Pulse wave velocity was determined and stiffness index (SIDVP) was calculated. Combined primary endpoints (CV and renal) were major CV events (myocardial infarction, stroke, and CV intervention) as CV endpoints, and attaining of ESRD or start of renal replacement therapy as renal endpoints. Secondary endpoints were CV or renal endpoints separately.

Results

The mean age of those 55 ADPKD patients was 45 ± 12 years, 21 patients were male. The average value of the SIDVP was 11.11 ± 2.22 m/s. The patients were divided into two groups by the cutoff value of 11 m/s of SIDVP and then outcomes were analyzed. In the higher arterial stiffness group (SIDVP > 11 m/s), occurrence of combined primary endpoint (CV and renal) was significantly higher than in the group with more elastic arteries (p = 0.033). A statistically significant difference was found in the renal endpoints (p = 0.018), but not in the CV endpoints (p = 0.952) between the two groups.

Conclusions

Increased arterial stiffness predicts the onset of ESRD in ADPDK. Assessment of SIDVP appears to be a useful method for estimating the renal and CV prognosis in ADPKD.

Volume status and arterial blood pressures are associated with arterial stiffness in hemodialysis patients

BACKGROUND

Arterial stiffness is a strong predictor of mortality in hemodialysis patients. In this study, we aimed to investigate possible relations of arterial stiffness with volume status determined by bioimpedance analysis and aortic blood pressure parameters. Also, effects of a single hemodialysis session on these parameters were studied.

METHODS

A total of 75 hemodialysis patients (M/F: 43/32; mean age: 53 ± 17) were enrolled. Carotid-femoral pulse wave velocity, augmentation index, and aortic pulse pressure were measured by applanation tonometry before and after hemodialysis. Extracellular fluid and total body fluid volumes were determined by bioimpedance analysis.

RESULTS

Carotid-femoral pulse wave velocity (9.30 ± 3.30 vs 7.59 ± 2.66 m/s, p < 0.001), augmentation index (24.52 ± 9.42 vs 20.28 ± 10.19, p < 0.001), and aortic pulse pressure (38 ± 14 vs 29 ± 8 mmHg, p < 0.001) significantly decreased after hemodialysis. Pre-dialysis carotid-femoral pulse wave velocity was associated with age (r² = 0.15, p = 0.01), total cholesterol (r² = 0.06, p = 0.02), peripheral mean blood pressure (r² = 0.10, p = 0.005), aortic-mean blood pressure (r² = 0.06, p = 0.02), aortic pulse pressure (r² = 0.14, p = 0.001), and extracellular fluid/total body fluid (r² = 0.30, p < 0.0001). Pre-dialysis augmentation index was associated with total cholesterol (r² = 0.06, p = 0,02), aortic-mean blood pressure (r² = 0.16, p < 0.001), and aortic pulse pressure (r² = 0.22, p < 0.001). Δcarotid-femoral pulse wave velocity was associated with Δaortic-mean blood pressure (r² = 0.06, p = 0.02) and inversely correlated with baseline carotid-femoral pulse wave velocity (r² = 0.29, p < 0.001). Pre-dialysis Δaugmentation index was significantly associated with Δaortic-mean blood pressure (r² = 0.09, p = 0.009) and Δaortic pulse pressure (r² = 0.06, p = 0.03) and inversely associated with baseline augmentation index (r² = 0.14, p = 0.001). In multiple linear regression analysis (adjusted R² = 0.46, p < 0.001) to determine the factors predicting Log carotid-femoral pulse wave velocity, extracellular fluid/total body fluid and peripheral mean blood pressure significantly predicted Log carotid-femoral pulse wave velocity (p = 0.001 and p = 0.006, respectively).

CONCLUSION

Carotid-femoral pulse wave velocity, augmentation index, and aortic pulse pressure significantly decreased after hemodialysis. Arterial stiffness was associated with both peripheral and aortic blood pressure. Furthermore, reduction in arterial stiffness parameters was related to reduction in aortic blood pressure. Pre-dialysis carotid-femoral pulse wave velocity was associated with volume status determined by bioimpedance analysis. Volume control may improve not only the aortic blood pressure measurements but also arterial stiffness in hemodialysis patients.

Comparison of the CHADS2, CHA2DS2-VASc and R2CHADS2 Scores in Japanese Patients with Non-valvular Paroxysmal Atrial Fibrillation Not Receiving Anticoagulation Therapy

Objective It remains unclear whether the CHADS2, CHA2DS2-VASc, or R2CHADS2 score is the most useful for the risk stratification of ischemic stroke/systemic thromboembolism (IS/SE) in Japanese patients with paroxysmal non-valvular atrial fibrillation (PNVAF). Methods We investigated the incidence of IS/SE on the basis of the CHADS2, CHA2DS2-VASc, and R2CHADS2 scores in 332 consecutive PNVAF patients (224 men, mean age: 65±13 years) who had not been administered anticoagulation therapy but who were administered antiarrhythmic drug therapy to maintain sinus rhythm between August 1995 and July 2008 before the 2008 Japanese Circulation Society guideline was issued (mean follow-up period: 53±35 months). Results The annual rates of IS/SE without underlying antiarrhythmic drug therapy are shown in the table included in this article. Higher CHADS2, CHA2DS2-VASc, and R2CHADS2 scores were associated with greater annual rates of IS/SE (p<0.001). In a multivariate logistic regression analysis adjusted for potentially confounding variables, the CHADS2 scores [odds ratio (OR): 4.74, 95% confidence interval (CI): 2.80-8.00, p<0.001], CHA2DS2-VASc scores (OR: 4.15, 95% CI: 2.57-6.71, p<0.001), and R2CHADS2 scores (OR: 1.94, 95% CI: 1.48-2.53, p<0.001) were significant independent predictors of IS/SE. The area under the receiver-operator characteristic curve for predicting IS/SE was 0.89 for CHA2DS2-VASc scores, 0.87 for CHADS2 scores, and 0.85 for R2CHADS2 scores (all, p<0.001), with no significant difference among the three scores. Conclusion In Japanese patients with PNVAF, the CHADS2, CHA2DS2-VASc, and R2CHADS2 scores are all useful for the risk stratification of IS/SE cases.

Cholesterol lowering treatment restores blood global DNA methylation in chronic kidney disease (CKD) patients

BACKGROUND AND AIMS

Chronic kidney disease (CKD) is characterized by increased oxidative stress (OS). In consideration of the well-known link between OS and DNA methylation we assessed DNA methylcytosine (mCyt) concentrations in CKD patients at baseline and during cholesterol lowering treatment.

METHODS AND RESULTS

DNA methylation and OS indices (malonyldialdehyde, MDA; allantoin/uric acid ratio, All/UA) were measured in 30 CKD patients randomized to three cholesterol lowering regimens for 12 months (simvastatin 40 mg/day, ezetimibe/simvastatin 10/20 mg/day, or ezetimibe/simvastatin 10/40 mg/day) and 30 age- and sex-matched healthy controls. DNA methylation was significantly lower in CKD patients vs. controls (4.06 ± 0.20% vs. 4.27 ± 0.17% mCyt, p = 0.0001). Treatment significantly increased mCyt DNA concentrations in all patients (4.06 ± 0.04% at baseline; 4.12 ± 0.03% at 4 months; 4.17 ± 0.03% at 8 months; and 4.20 ± 0.02% at 12 months, p = 0.0001 for trend). A trend for a greater effect on DNA methylation was observed with combined treatment ezetimibe/simvastatin 10/40 mg/day (+5.2% after one year treatment). The treatment-associated mCyt increase was significantly correlated with the concomitant reduction in MDA concentrations and All/AU ratios.

CONCLUSION

Our results demonstrate that CKD patients have a lower degree of DNA methylation and that cholesterol lowering treatment restores mCyt DNA concentrations to levels similar to healthy controls. The treatment-associated increase in DNA methylation is correlated with a concomitant reduction in OS markers. The study was registered at clinicaltrials.gov (NCT00861731).

Resveratrol Ameliorated Vascular Calcification by Regulating Sirt-1 and Nrf2

Pathologic vascular calcification is a significant reason for mortality and morbidity in patients who suffer from end-stage renal disease (ESRD). Resveratrol, a scavenger for many free radicals, is a crucial compound for biomedicine. However, the role and mechanism of resveratrol in vascular calcification is still unknown. In this study, to mimic vascular calcification in ESRD, we used β-glyceophosphate to stimulate the rat vascular smooth muscle cells (RASMCs). We investigate the therapeutic role of resveratrol pretreatment in vascular calcification. In the current in vitro study, we observe the effects of resveratrol on improving intracellular calcium deposition and protecting against mitochondria dysfunction in calcific RASMCs. Resveratrol decreased the mRNA level of fibroblast growth factor-23, then increased the mRNA level of klotho and the nuclear transcription factor NF-E2-related factor 2 (nuclear factor-erythroid 2-related factor 2 [Nrf2]) in RASMCs after calcification. Further, resveratrol activated the expression of sirtuin-1 and Nrf2, and inhibited the expression of osteopontin, runt-related transcription factor 2, and heme oxygenase-1. Our study shows that resveratrol could ameliorate oxidative injury of RASMCs by preventing vascular calcification-induced calcium deposition and mitochondria dysfunction through involving sirtuin-1 and Nrf2. These results might indicate a novel role for resveratrol in resistance to oxidative stress for ESRD patients suffering from vascular calcification.

Contribution of volume overload to the arterial stiffness of hemodialysis patients

Arterial stiffness is evaluated with the measurement of pulse wave velocity (PWV), while overhydration (OH) and nutritional status are evaluated with bioimpedance spectroscopy (BIS). In this study, we investigated the effect of a single dialysis session on arterial stiffness, hydration status, and laboratory parameters. The observational, cross-sectional, cohort study included 71 HD patients with mean age 64 ± 16 yrs. A Complior device was used to perform PWV measurements. The patients were examined immediately before and 15 min after a mid-week hemodialysis session. Body fluids and nutritional status were studied using a Body Composition Monitor (BCM), Fresenius Medical Care. Clinical and laboratory data were also analyzed. Multivariate regression analysis of PWV before HD showed that an OH increase of 1 L relate to a PWV parameter rise before HD of 0.523 m/s. Multivariate regression analysis of PWV after HD showed that a rise of central SBP after HD of 10 mmHg relate to a PWV increase after HD of 0.707 m/s. Our data indicate that hydration status and blood pressure may be major determinants of PWV in HD patients.

The reverse remodeling of the aorta in patients after renal transplantation - the value of aortic stiffness index: prospective echocardiographic study

BACKGROUND

Atherosclerosis is regarded as a combination of two major separate diseases: atherosis and sclerosis. Sclerotic component depends on deterioration of elastic properties of the aortic wall and is called aortic stiffness. The most valuable, non-invasive method of aortic stiffness assessment is echocardiography, which allows to calculate the aortic stiffness index (ASI). ASI is an independent predictor of all-cause and cardiovascular mortality in different groups of patients. The main aim of study was the assessment of the aortic reverse remodeling in patients with end-stage renal disease (ESRD) after renal transplantation (RT).

METHODS

Study group involved 42 patients aged 43.3 ± 12.6 years, including 19 women aged 49.9 ± 10.9 years and 23 men aged 41.5 ± 12.91 years, who have undergone RT from non-related renal transplant donors, The study protocol has been consisted of 5 stages: 1 week after RT, 3 months after RT, 6 months after RT, 1 year after RT and 3 years after RT. The echocardiographic examination was performed and measurements of Ao_max, Ao_min were done. On the base of obtained parameters ASI, aortic distensibility (AD) and aortic strain (AS) were calculated according to adequate formulas.

RESULTS

The improvement of indices characterizing the elastic properties of aorta were noted. These changes attained the statistically significant level only at the end of the observation. ASI just after RT was equal - 4.65 ± 1.58, three months after RT - 4.54 ± 1.49, six months after RT - 4.59 ± 1.61, one year after RT - 4.35 ± 1.21 and three years after RT - 3.35 ± 1.29, while AD reached respectively - 6.55 ± 3.76 cm²/dyn^-110^-6 just after RT, - 6.38 ± 3.42 cm²/dyn^-110^-6 three months after RT, - 6.53 ± 3.60 cm²/dyn^-110^-6 six months after RT, - 6.48 ± 2.79 cm²/dyn^-110^-6 one year after RT and - 8.03 ± 3.95 cm²/dyn^-110^-6 three years after RT. Noted AS values were equal - 6.61 ± 4.05%, just after RT, - 6.40 ± 3.58% three months after RT, - 6.56 ± 3.76%, six months after RT, - 6.45 ± 2.80% one year after RT, - 8.01 ± 3.97%. and three years after RT. The exact analysis of parameters concerning aortic function showed that to achieve ASI, AD and AS improvement, long time was needed, because the most significant changes of these indices were observed only between 1 year and 3 years after RT.

CONCLUSIONS

There is a relationship between renal transplantation and improvement of the aortic elastic properties. The recovery of the renal function allows to initiate the reparative processes leading to at least partial restitution of the structure and features of the aorta, which is called reverse remodelling. Improvement of aortic wall elastic properties after renal transplantation is a continuous and prolonged process.

Ambulatory Blood Pressure in Chronic Kidney Disease: Ready for Prime Time?

Hypertension is common in patients with chronic kidney disease (CKD) and is the most important modifiable risk factor for CKD progression and adverse cardiovascular events in these patients. Diagnosis and successful management of hypertension are critically dependent on accurate blood pressure (BP) measurement. This is most relevant to CKD patients, in whom BP control is difficult to achieve and in whom early antihypertensive treatment is imperative to prevent kidney and cardiovascular complications. Accumulated data indicate that ambulatory blood pressure monitoring (ABPM) is better in detecting hypertension than office BP measurement. ABPM is also a superior prognostic marker compared with office BP and has successfully identified hypertensive CKD patients at increased risk. Additionally, ABPM provides information on circadian BP variation and short-term BP variability, which is associated with cardiovascular and renal outcomes. This paper reviews the evidence for the usefulness of ABPM in detection and management of hypertension in CKD patients and discusses our current understanding of the pathophysiology of altered circadian BP rhythm and variability in CKD and the role of abnormal BP patterns detected by ABPM in relation to outcomes in CKD. In addition, this Review examines the emerging role of antihypertensive chronotherapy to tailor BP management to the circadian BP pattern abnormality detected by 24-hour ABPM.

Intracranial Artery Calcification and Its Clinical Significance

Intracranial arterial calcification (IAC) is an easily identifiable entity on plain head computed tomography scans. Recent studies have found high prevalence rates for IAC worldwide, and this may be associated with ischemic stroke and cognitive decline. Aging, traditional cardiovascular risk factors, and chronic kidney disease have been found to be associated with IAC. The severity of IAC can be assessed using different visual grading scales or various quantitative methods (by measuring volume or intensity). An objective method for assessing IAC using consistent criteria is urgently required to facilitate comparisons between multiple studies involving diverse populations. There is accumulating evidence from clinical studies that IAC could be utilized as an indicator of intracranial atherosclerosis. However, the pathophysiology underlying the potential correlation between IAC and ischemic stroke-through direct arterial stenosis or plaque stability-remains to be determined. More well-designed clinical studies are needed to explore the predictive values of IAC in vascular events and the underlying pathophysiological mechanisms.

Impact of coronary artery calcification in percutaneous coronary intervention with paclitaxel-eluting stents: Two-year clinical outcomes of paclitaxel-eluting stents in patients from the ARRIVE program

OBJECTIVES

The purpose of this study was to evaluate clinical outcomes after percutaneous coronary intervention (PCI) in patients with coronary artery calcification (CAC).

BACKGROUND

Smaller studies have reported worse clinical outcomes in patients with CAC who undergo PCI. The impact of CAC in the drug-eluting stent era is unclear.

METHODS

Data from 7,492 patients treated by PCI with ≥1 TAXUS Express stent in the ARRIVE registry with no inclusion/exclusion criteria were stratified by the severity of CAC, as determined by the operator. Endpoints were independently adjudicated. All major adverse cardiac events were assessed at 2 years.

RESULTS

Moderate/severe CAC was present in 19.6%. The nil/mild CAC group had higher rate of current smokers. The moderate/severe CAC group was older and had a higher prevalence of hypertension, kidney disease, prior coronary artery bypass grafting, congestive heart failure, and left main disease. After adjustment for imbalanced baseline variables, patients with moderate/severe CAC had higher 2 year rates of major adverse cardiac events (18.3% vs 13.5%, p = 0.01) and death (10.3% vs 5.6%, p = 0.02).

CONCLUSIONS

Moderate/severe CAC was associated with increased clinical events in patients who underwent PCI with TAXUS stents. This may be explained in part due to differences important baseline characteristics including more patients with more comorbidities and more complex lesions. After adjustment for imbalanced baseline variables, the moderate/severe CAC group had a higher risk of major adverse cardiac events and death. Improvements in treatment strategies are needed for this high-risk group of patients who undergo PCI. © 2016 Wiley Periodicals, Inc.

Aortic pulse wave velocity is associated with measures of subclinical target organ damage in patients with mild hypertension

We evaluated the temporal association between aortic arterial stiffness and subclinical target organ damage, including renal function decline, left ventricular geometric remodeling, and left ventricular diastolic dysfunction in patients with mild hypertension. Automatic pulse wave velocity (PWV) measuring system was applied to examine carotid-femoral PWV (CFPWV) reflecting aortic arterial stiffness in 644 essential hypertensive patients. Clinical data were collected, and cardiac structure and function were assessed by echocardiography. CFPWV was significantly and positively associated with left ventricular mass index (r = 0.153, P = 0.018), relative wall thickness (r = 0.235, P < 0.001), and left atrial diameter (r = 0.192, P = 0.003), and negatively with E/A ratio (r = -0.361, P < 0.001) and creatinine clearance (r = -0.248, P < 0.001). Logistic regression analysis demonstrated that CFPWV remained significantly correlated with renal function decline (P = 0.011), left ventricular diastolic dysfunction (P = 0.009) and left ventricular geometric remodeling (P = 0.020). Higher CFPWV was independently associated with greater burden of subclinical disease in renal impairment, left ventricular geometric remodeling and diastolic dysfunction.

Efficacy of losartan for improving insulin resistance and vascular remodeling in hemodialysis patients

Insulin resistance and vascular remodeling are prevalent and predict cardiovascular mortality in hemodialysis patients. Angiotensin II (Ang II) may be involved in both pathogenesis. In the present study, we investigated the effects of the Ang II receptor blocker losartan on insulin resistance, arterial stiffness, and carotid artery structure in hemodialysis patients. Seventy-two hemodialysis patients were randomly assigned to receive either losartan 50 mg qd (n = 36) or β-blocker bisoprolol 5 mg qd (n = 36). At the start and at month 12, ambulatory blood pressure (BP) monitoring, aortic pulse wave velocity (PWV) measurements, and carotid artery ultrasound were performed, and homeostasis model assessment index of insulin resistance (HOMA-IR) was determined. During the study period, bioimpedance method was used to evaluate volume status every 3 months. Home-monitored BPs were measured at least monthly. Ambulatory BP decreased significantly and similarly by either losartan or bisoprolol. Decreases in PWVs in losartan group at the end of month 12 were significantly greater than changes in PWV in bisoprolol group (0.9 ± 0.3 vs. 0.4 ± 0.5 m/s, P = 0.021). Common carotid artery intima-media cross-sectional area decreased significantly only in patients treated with losartan (20.3 ± 4.9 vs. 19.1 ± 5.1 mm(2) , P = 0.001), and HOMA-IR was also reduced in losartan group only (1.9 ± 1.0 vs. 1.7 ± 0.8, P = 0.003). Multiple regression analysis showed significant correlations between changes in PWV and changes in HOMA-IR. With comparable BP-lowering efficacy, losartan achieved better improvement in insulin sensitivity, arterial stiffness, and carotid artery hypertrophy in hemodialysis patients. The regression of arterial stiffness may be in part through attenuation in insulin resistance.

The effects of single hemodialysis session on arterial stiffness in hemodialysis patients

Increased arterial stiffness in hemodialysis patients is a strong predictor of cardiovascular morbidity and mortality. Pulse wave velocity (PWV) and augmentation index (AIx), which are markers of arterial stiffness, were used to determine the severity of vascular damage noninvasively. This study aimed to investigate the effects of solute volume removal and hemodynamic changes on PWV and AIx of a single hemodialysis session. Thirty hemodialysis patients were enrolled in the study. Before initiation of hemodialysis, every 15 minutes during hemodialysis, and 30 minutes after the completion of the session, measurements of PWV and AIx@75 (normalized with heart rate 75 bpm) were obtained from each patient. Body composition was analyzed by bioimpedance spectroscopy device before and 30 minutes after completion of the hemodialysis session. During the hemodialysis, no significant change was observed in AIx@75. However, PWV decreased steadily during the session reaching statistically significant level at 135th minute (P = 0.026), with a maximal drop at 210th minute (P < 0.001). At 210th minute, decrease in PWV correlated positively with the decrease in central systolic blood pressure, central diastolic blood pressure, central pulse pressure, augmentation pressure, and AIx@75. Multiple regression analysis showed that decrease in PWV at 210th minute was associated with decrease in central systolic blood pressure and central pulse pressure. Ultrafiltration during hemodialysis had no significant effect on PWV and AIx@75. Delta urea correlated positively with delta PWV at 240th minute. A significant decrease in PWV was observed during hemodialysis and correlated with urea reduction; however, we were unable to document any effect of volume removal on arterial stiffness.

Associations between serum hepcidin level, FGF-21 level and oxidative stress with arterial stiffness in CAPD patients

BACKGROUND

Patients on continuous ambulatory peritoneal dialysis (CAPD) and hemodialysis have accelerated atherosclerosis associated with an increase in cardiovascular morbidity and mortality. Atherosclerosis is associated with increased arterial stiffness (AS), endothelial dysfunction and elevated oxidative stress (OS) and inflammation. We aimed to investigate the relationship between oxidative stress status, arterial stiffness, hepcidin and fibroblast growth factor-21 (FGF-21) levels in CAPD patients.

METHODS

As a prospective observational study, we analyzed 56 CAPD patients, aged between 30 and 63 years. Serum hepcidin, FGF-21 levels, OS status and AS were determined. Arterial stiffness was measured by flow-mediated dilatation (FMD). Oxidative stress status was determined by total antioxidant status, total oxidant status (TOS) and oxidative stress index (OSI).

RESULTS

FMD was negatively correlated with TOS, OSI, hepcidin and FGF-21 (r: -0.313, p: 0.020; r: -0.0331, p: 0.014; r: -0.498, p < 0.001; r: -0.403, p: 0.002, respectively). OSI was positively correlated with hepcidin, parathormone and negatively correlated with FMD (r: 0.278, p: 0.040; r: 0.462, p < 0.001; r: -0.0331, p: 0.014, respectively).

CONCLUSION

There are many factors affecting arterial stiffness in CAPD patients. In our study, higher levels of OS status, hepcidin and FGF-21 were independent determinants of arterial stiffness in PD patients. Therefore, definition and improvement of these new parameters will be helpful to reduce the cardiovascular disease risk and mortality in CAPD patients.

Role of Pulse Wave Velocity in Patients with Chronic Kidney Disease Stages 3-5 on Long-Term Follow-Up

BACKGROUND

The relationship between arterial stiffness and kidney function has not been clearly demonstrated although observations of higher arterial stiffness in patients with advanced stages of chronic kidney disease (CKD) were reported. In longitudinal analyses, there was no close association between basal arterial stiffness and progression of kidney function in the general population. In the present study, we assessed the relationship between arterial stiffness and progression of renal dysfunction in patients with CKD stages 3-5 using two types of measures of arterial stiffness, i.e., carotid-femoral pulse wave velocity (cfPWV) and brachial-ankle pulse wave velocity (baPWV), over a 10-year period.

METHODS

110 patients with CKD stages 3-5 (aged 57.8 ± 10.6 years; female/male: 72/38) were followed for 10 years. Before and at the end of the 10-year period, cfPWV and baPWV were measured using form PWV/ABI (Omron Colin Co. Ltd.).

RESULTS

Throughout the study, systolic blood pressure was well-controlled in all patients. Twenty-nine patients (26%) received renal replacement therapy, 12 patients (11%) developed cardiovascular diseases (CVDs), 5 patients were found to have neoplasm, and 9 patients dropped out of the study during the 10-year observation period. In patients who developed end-stage renal disease, the baseline estimated glomerular filtration rate (eGFR) was significantly lower, and in patients who developed CVD, the basal value of baPWV was significantly higher (p < 0.05). Throughout the study, blood pressures were controlled (136.1/77.0 ± 15.6/7.1 to 137.5/77.6 ± 14.9/11.2), kidney function worsened (eGFR, 30.8 ± 16.5 to 22.9 ± 17.6 ml/min/1.73 m(2); p < 0.01), and baPWV but not cfPWV showed a significant change [1, 672.2 ± 209.6 vs. 1,753.1 ± 333.2 cm/s (p = 0.04) and 918.9 ± 153.2 vs. 939.4 ± 133.2 cm/s]. Moreover, the difference in PWV between the start and the end of the 10-year observation period was positively correlated with the difference in eGFR.

CONCLUSION

With moderate progression of renal dysfunction and under well-controlled blood pressure, peripheral but not central arterial stiffness is possibly one of the strongest predictors of CVD in patients with CKD stages 3-5.

Short-term aerobic exercise and vascular function in CKD stage 3: a randomized controlled trial

BACKGROUND

The present study was designed to determine the effect of short-term moderate-intensity exercise training on arterial stiffness in patients with chronic kidney disease (CKD) stage 3.

STUDY DESIGN

Randomized controlled trial with a parallel-group design.

SETTING & PARTICIPANTS

Testing and training sessions were performed at Springfield College. 46 (treatment group, n=25; control group, n=21) patients with CKD with diabetes and/or hypertension completed the study.

INTERVENTION

The aerobic training program consisted of 16 weeks of supervised exercise training at 50%-60% peak oxygen uptake (Vo2peak) 3 times per week, while the control group remained sedentary. Identical testing procedures were performed following the 16-week intervention.

OUTCOMES

The primary outcome was arterial stiffness. Secondary outcomes were aerobic capacity, various blood parameters (endothelin 1, nitrate/nitrite, and high-sensitivity C-reactive protein), and health-related quality of life.

MEASUREMENTS

Arterial stiffness was assessed with aortic pulse wave velocity (PWV), aerobic capacity by Vo2peak, blood parameters by enzyme-linked immunosorbent assays, and health-related quality of life by the 36-Item Short Form Health Survey (SF-36). Participants attended 4 sessions before being randomly assigned to either the treatment or control group. Participants gave consent during the first session, whereas a graded exercise test with measurement of Vo2peak was completed during the second session. During sessions 3 and 4, aortic PWV was measured at rest prior to 40 minutes of either moderate-intensity exercise training or seated rest. A venous blood sample was obtained prior to exercise or rest and participants completed the SF-36 questionnaire.

RESULTS

16 weeks of training led to an 8.2% increase in Vo2peak for the treatment group (P=0.05), but no changes in aortic PWV .

LIMITATIONS

Randomization was not concealed and was violated on one occasion; also, use of an indirect measurement of endothelial function and the short duration of the intervention.

CONCLUSIONS

Short-term moderate-intensity exercise training does not alter arterial stiffness in patients with CKD, but seems to reduce endothelin 1 levels.

Aortic to brachial pulse pressure amplification as functional marker and predictor of renal function loss in chronic kidney disease

Pulse pressure amplification (PPA) reflects large artery function. Its contribution in chronic kidney disease (CKD) remains uncertain. The authors assessed PPA in CKD progression in patients with CKD stage 2 to 4 (n=128) and 89 controls (follow-up: 42 months). PPA was reduced in CKD patients as compared with control patients and associated with decline in renal function. Sixteen renal endpoints, defined by 50% loss of renal function or start of renal replacement therapy, were detected. In Cox regression analysis, PPA, estimated glomerular filtration rate, and proteinuria predicted renal endpoints. Patients with CKD stage 4 and low PPA had the highest risk for developing renal endpoints (unadjusted 8.1; 2.4-27.7 and adjusted for age and proteinuria 5.6; 1.5-21.9, log-rank P<.001). Taken together, PPA is reduced in CKD and is associated with declining renal function. In addition, low PPA predicts renal endpoints in severe CKD. Furthermore, this study emphasizes the role of systolic blood pressure as a major determinant of PPA.

The combination of the ankle brachial index and brachial ankle pulse wave velocity exhibits a superior association with outcomes in diabetic patients

OBJECTIVE

Patients with type 2 diabetes mellitus (T2DM) and peripheral arterial disease are classified as having very high cardiovascular risks. We therefore sought to determine whether assessments of the ankle brachial index (ABI) and brachial ankle pulse wave velocity (baPWV) together exhibited a superior association with the outcomes of T2DM.

METHODS

A retrospective analysis of patients receiving ABI and baPWV during the period 2005-2007 was performed. Patients A total of 452 subjects were enrolled and followed-up for a mean 5.8 years after being grouped according to the ABI (<0.9 vs. ≥0.9) and baPWV (<1,700 cm/s vs. ≥1,700 cm/s).

RESULTS

The outcomes were all-cause mortality and composite events (all-cause mortality, hospitalization for coronary artery disease, stroke, re-vascularization, amputation and diabetic foot). Inter-group differences in the smoking rate, duration of diabetes, systolic and pulse blood pressure, anti-platelet drugs, estimated glomerular filtration rate, and urine albumin excretion were significant. During the follow-up period, 17 (3.7%) individuals died and composite events were recorded in 64 cases (14.1%). A low ABI plus high baPWV was found be associated with poor outcomes compared with a normal ABI plus low baPWV (p<0.001). Meanwhile, a low ABI plus high baPWV was associated with an increased risk of all-cause mortality [hazard ratio (HR) 17.01, 95% confidence interval (CI) 1.57-183.73, p=0.019] and composite events (HR 8.53, 95% CI 3.31-21.99, p<0.001).

CONCLUSION

In this study, the outcomes of patients with a low ABI plus high baPWV were the worst, while the subjects with a low ABI plus low baPWV or normal ABI exhibited similar outcomes. Therefore, the ABI plus baPWV exhibits a better association with the outcomes of T2DM.

Impact of the severity of coronary artery calcification on clinical events in patients undergoing coronary artery bypass grafting (from the Acute Catheterization and Urgent Intervention Triage Strategy Trial)

The treatment of calcified coronary lesions by percutaneous coronary intervention has been shown to be associated with poor outcomes and an increased rate of complications. However, the impact of coronary calcification in patients undergoing coronary artery bypass grafting (CABG) is unknown. A total of 755 patients presenting with acute coronary syndrome in the Acute Catheterization and Urgent Intervention Triage Strategy trial underwent CABG. Patients were divided into 3 groups according to the presence and extent of coronary calcifications (lesion level: severe, moderate, none to mild) as assessed by an independent angiographic core laboratory. Major ischemic and bleeding outcomes were assessed at 30 days and 1 year. Severe calcification was found in 103 patients (13.6%), moderate calcification in 249 patients (33.0%), and none-to-mild calcification in 403 patients (53.4%). The presence of severe calcification compared with moderate or none to mild was associated with a significantly higher unadjusted rate of death (11.8% vs 3.7% vs 4.5%, p = 0.006), death or myocardial infarction (MI; 31.1% vs 19.7% vs 16.4%, p = 0.006), and major adverse cardiac event (MACE; 32.0% vs 22.6% vs 20.8%, p = 0.059) at 1 year. By multivariate analysis, severe calcification (vs nonsevere calcification) was identified as an independent predictor of 1-year MACE (hazard ratio 1.49, 95% confidence interval 1.01 to 2.21, p = 0.04) and death or MI (hazard ratio 1.77, 95% confidence interval 1.18 to 2.66, p = 0.006). In conclusion, the presence of severe coronary calcification was associated with worse outcomes after CABG, including an increased risk of death. The presence of severe coronary calcification was identified as an independent predictor of MACE and death or MI 1 year after CABG.

Definition, identification and treatment of resistant hypertension in chronic kidney disease patients

Resistant hypertension, the inability to achieve goal blood pressure despite the use of three or more appropriately dosed antihypertensive drugs (including a diuretic), remains a common clinical problem, especially in patients with chronic kidney disease (CKD). While the exact prevalence and prognosis of resistant hypertension in CKD patients remain unknown, resistant hypertension likely contributes significantly to increased cardiovascular risk and progression of kidney disease in this population. We review the identification and evaluation of patients with resistant hypertension, including the importance of 24-h ambulatory blood pressure monitoring in the identification of 'white-coat', 'masked' and 'non-dipper' hypertension, the latter of which has particular clinical and therapeutic importance in patients with resistant hypertension and CKD. We then discuss treatment strategies for resistant hypertension that target the pathophysiologic mechanisms underlying resistance to treatment, including persistent volume excess, incomplete renin-angiotensin-aldosterone system blockade and inadequate nocturnal blood pressure control. Finally, we propose a treatment algorithm for evaluation and treatment of resistant hypertension in patients with CKD.

A new echocardiographic parameter of arterial stiffness in end-stage renal disease

BACKGROUND

Cardiovascular disease is the leading cause of death among patients with end-stage renal disease (ESRD). Arterial stiffness is an independent predictive parameter of overall and cardiovascular mortality in these patients. However, the defined procedures for the measurement of arterial stiffness are time consuming and not practical in daily practice.

METHODS

The study population included 50 patients with ESRD who were treated with hemodialysis (HD; n=23) or peritoneal dialysis (PD; n=27) and 70 age- and sex-matched control subjects. Aortofemoral pulse wave velocity (PWV), carotid intima-media thickness (CIMT), and color M-mode propagation velocity of the descending aorta (aortic propagation velocity, APV) were measured.

RESULTS

Compared to the control group, the patients with ESRD had significantly lower APV (46.4 ± 12.4 vs. 58.5 ± 8.5, p < 0.01) and higher PWV (10.5 ± 2.5 vs. 9.2 ± 1.2, p < 0.01) and CIMT (0.66 ± 0.15 vs. 0.43 ± 0.06, p < 0.01) measurements. There were significant correlations between APV and CIMT (r = - 0.769, p < 0.001), APV and PWV (r = - 0.682, p < 0.001), and PWV and CIMT (r = 0.564, p < 0.001). There were no significant differences in APV and PWV between the PD and HD patients.

CONCLUSION

Arterial stiffness is an important indicator of atherosclerosis and arterial aging in patients with ESRD. The measurement of APV is an easy and practical new echocardiographic method and may be used to identify arterial stiffness in these patients.

Effect of isovolemic, isothermic hemodialysis on cerebral perfusion and vascular stiffness using contrast computed tomography and pulse wave velocity

Background

Patients undergoing hemodialysis treatment have a six-fold increased risk for stroke relative to the general population. However, the effect of hemodialysis on cerebral blood flow is poorly studied and confounding factors like blood pressure and ultrafiltration as well as temperature changes have rarely been accounted for. The aim of our study was to use state-of-the-art technology to evaluate the effect of a single dialysis session on cerebral perfusion as well as on vascular stiffness.

Methods

Chronic hemodialysis patients (7 male/3 female, mean age 58 years) were recruited. Cerebral blood flow and arterial pulse wave velocity were measured before and immediately after a hemodialysis session. To exclude effects of volume changes we kept ultrafiltration to a minimum, allowing no change in body weight. Isothermic conditions were maintained by using the GENIUS single-pass batch-dialysis system with a high-flux polysulfone dialyser. Cerebral blood flow was measured by contrast-enhanced computed tomography. Pulse wave velocity was measured using the SphygmoCor (AtCor Medical, USA) device by a single operator.

Results

This study shows for the first time that isovolemic, isothermic hemodialysis neither affected blood pressure or heart rate, nor total or regional cerebral perfusion. There was also no change in pulse wave velocity.

Conclusions

Mechanisms other than the dialysis procedure itself might be causative for the high incidence of ischemic strokes in this patient population. Moreover, the sole removal of uremic toxins does not lead to short-term effects on vascular stiffness, underlying the importance of volume control in this patient population.

Endothelin-A receptor antagonism modifies cardiovascular risk factors in CKD

Arterial stiffness and impaired nitric oxide (NO) bioavailability contribute to the high risk for cardiovascular disease in CKD. Both asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO production, and endothelin-1 (ET-1) oppose the actions of NO, suggesting that ET-1 receptor antagonists may have a role in cardiovascular protection in CKD. We conducted a randomized, double-blind, three-way crossover study in 27 patients with proteinuric CKD to compare the effects of the ET(A) receptor antagonist sitaxentan, nifedipine, and placebo on proteinuria, BP, arterial stiffness, and various cardiovascular biomarkers. After 6 weeks of treatment, placebo and nifedipine did not affect plasma urate, ADMA, or urine ET-1/creatinine, which reflects renal ET-1 production; in contrast, sitaxentan led to statistically significant reductions in all three of these biomarkers. No treatment affected plasma ET-1. Reductions in proteinuria and BP after sitaxentan treatment was associated with increases in urine ET-1/creatinine, whereas reduction in pulse-wave velocity, a measure of arterial stiffness, was associated with a decrease in ADMA. Taken together, these data suggest that ET(A) receptor antagonism may modify risk factors for cardiovascular disease in CKD.

The contribution of thyroid dysfunction on cardiovascular disease in patients with chronic kidney disease

Accelerated atherosclerosis and arterial stiffness are the two leading causes of increased cardiovascular disease in patients with chronic kidney disease. Dysfunctional thyroid hormone metabolism has been suggested to play a role in atherosclerosis and arterial stiffness. Changes in cardiac contractility and output, myocardial oxygen demand, systemic and peripheral vascular resistance, blood pressure and lipid profile, increased inflammatory burden and endothelial dysfunction may be responsible for thyroid hormone-related cardiovascular disease. This article focuses on the mechanistic insights of this association and provides a concise review of the current literature.

Association of blood pressure with the start of renal replacement therapy in elderly compared with young patients receiving predialysis care

BACKGROUND

In the growing elderly predialysis population, little is known about the effect of identified risk factors on the progression to end-stage renal disease. Therefore, we investigated the association of systolic (SBP) and diastolic blood pressure (DBP) with the start of renal replacement therapy (RRT), in elderly (≥65 years) compared with young (<65 years) predialysis patients.

METHODS

In the PREPARE-1 cohort, 547 incident predialysis patients, referred as part of the usual care to eight Dutch predialysis care outpatient clinics, were included (1999-2001) and followed until the start of dialysis, transplantation, death, or until 1 January 2008. The outcome was the start of RRT. All analyses were stratified for age; <65 years (young) and ≥65 years (elderly).

RESULTS

In young predialysis patients (n = 268) higher SBP (every 20 mm Hg increase) and high DBP (DBP ≥100 mm Hg compared with 80-89 mm Hg) were associated with a higher rate of starting RRT (adjusted hazard ratio (HR) (95% confidence interval) 1.21 (1.09;1.34) and 1.74 (1.16;2.62), respectively). However, in elderly predialysis patients (n = 240) only patients with SBP ≥180 mm Hg had an increased rate compared with patients with 140-159 mm Hg (adjusted HR 2.33 (1.41;3.87)). Furthermore, patients with DBP <70 or ≥100 mm Hg had an increased rate of starting RRT, independent of SBP, compared with patients with 80-89 mm Hg (fully adjusted HR 1.72 (1.01;2.94) and 2.05 (1.13;3.73), respectively).

CONCLUSIONS

The association of SBP and DBP with the start of RRT is different between elderly and young predialysis patients.

Unusual presentation of Mönckeberg's sclerosis in the thyroid vessels of three female patients

Histopathological findings of Mönckeberg's sclerosis in the thyroid vessels of three female patients are described. Two of the patients presented with papillary carcinoma and the third presented with two cystic adenomatous nodules. Lesions of chronic lymphocytic thyroiditis were observed in two of the cases. The presence of Mönckeberg's sclerosis is an indication for further examination of patients' vascular systems because of the high risk for cardiovascular events.

Stiffness parameter β as a predictor of the 4-year all-cause mortality of chronic hemodialysis patients

BACKGROUND

There is a lack of information on stiffness parameter β, an index of arterial stiffness, in hemodialysis (HD) patients. The aim of the present study was to investigate whether stiffness parameter β is predictive of the long-term mortality of chronic HD patients.

METHODS

We measured biochemical parameters and the stiffness parameter β of 80 patients on maintenance HD therapy and followed their course for 4 years, and we enrolled 70 of these 80 patients in the study. We divided the 70 patients into tertiles according to their stiffness parameter β values, and conducted multivariate analyses to examine the impact of the tertiles on 4-year mortality.

RESULTS

Older age and the presence of diabetes mellitus were found to be independently associated with higher stiffness parameter β values. Fifteen patients (21.4 %) died and 16 (22.9 %) experienced a new cardiovascular event during the follow-up period. The results of a Kaplan-Meier analysis revealed a significantly higher risk of all-cause mortality in the HD patients with highest stiffness parameter β values (p = 0.0106). According to the ROC curve, the cut-off level that yielded maximal sensitivity and specificity for predicting all-cause mortality was 10.1, and the sensitivity and specificity using the cut-off value were 69.2 and 70.2 %, respectively.

CONCLUSION

The results of this study suggest that stiffness parameter β is a predictor of all-cause mortality in chronic HD patients.

Endothelial dysfunction in uremic patients on continuous ambulatory peritoneal dialysis (CAPD)

Endothelial dysfunction is associated with diabetic micro- and macroangiopathy as well as with the decline in creatinine clearance. It has been suggested that endothelial dysfunction presents in patients (pts) on continuous ambulatory peritoneal dialysis (CAPD). The objective of this study was to examine the plasma biomarkers of endothelial dysfunction and their association with IMT of carotid arteries in diabetic and non-diabetic patients on CAPD. This study included 37 CAPD pts (25 with type II diabetes and 12 non-diabetic pts) mean age 59.2 years ± 2.48. Plasma von Willebrand factor (vWF) activity, serum albumin, glucose, total cholesterol, triglycerides and lipoprotein (a) levels, as well as serum level of homocysteine, parathyroid hormone (PTH) in plasma and microalbuminuria was determined. Ultrasound examination of carotid arteries was performed in all patients by measured bilateral intima-media thickness of carotid artery (CIMT). Mean IMT value was significantly higher in type 2 DM patients (0.86 ± 0.04 mm) compared to non-diabetic patients (0.52 ± 0.06 mm) on peritoneal dialysis (p<0.0001). There was also a significant difference in lipids /triglycerides and Lp (a)/, procoagulation (fibrinogen, von Wilebrand factor, factor VIII) and inflammatory markers (CRP) level between type 2 DM and non-diabetic CAPD patients. A stepwise multiple regression analysis revealed that log triglycerides and factor VIII were independent factors for the IMT. The results of this research impose that diabetic type 2 CAPD patients have developed systemic alteration of endothelial function and higher risk of cardiovascular complications compared to non-diabetic CAPD patients.

Factors related to pulse wave velocity and augmentation index in chronic hemodialysis patients

BACKGROUND

Augmentation index (AIx) and pulse wave velocity (PWV) are early markers of atherosclerotic vascular changes and also have been shown to be predictive of cardiovascular disease and total mortality. The aim of our study was to evaluate the relationship between PWV and AIx-HR75, which is the corrected form of AIx according to a heart rate of 75 beats/min, echocardiographic parameters and biochemical parameters in chronic hemodialysis (HD) patients.

SUBJECTS AND METHODS

AIx-HR75 and PWV were measured in 556 HD patients by applanation tonometry using the SphygmoCor device.

RESULTS

The mean PWV and AIx-HR75 values of the study group were 10.2 ± 2.4 and 28.4 ± 10.2 m/s. A positive correlation was found between PWV and AIx-HR75 (r = 0.214, p = 0.000). AIx-HR75 correlated with age (r = 0.093, p = 0.028), body surface area (BSA) (r = -0.194, p = 0.000), mean arterial pressure (MAP) (r = 0.335, p = 0.000), pulse pressure (PP) (r = 0.212, p = 0.000), cardiothoracic index (r = 0.155, p = 0.016), and presence of left ventricular hypertrophy (r = 0.152, p = 0.001). PWV correlated with MAP (r = 0.208, p = 0.000), PP (r = 0.098, r = 0.021), left ventricular mass (r = 0.105, p = 0.023), and predialysis sodium level (r = -0.105, p = 0.023). In the multivariate analyses, PWV was associated with MAP (t = 3.78, p = 0.000), presence of diabetes (t = 3.20, p = 0.001), and predialysis sodium level (t = -2.06, p = 0.040), and AIx-HR75 was associated with age (t = 2.48, p = 0.014), female sex (t = 3.98, p = 0.000), BSA (t = -2.15, p = 0.033), and MAP (t = 7.02, p = 0.000).

CONCLUSION

There is a strong association between MAP and arterial stiffness parameters in HD patients. We feel that efficient control of blood pressure could lead to reduced arterial stiffness in HD patients.

Association of blood pressure with decline in renal function and time until the start of renal replacement therapy in pre-dialysis patients: a cohort study

Background

To investigate whether high blood pressure accelerates renal function decline in patients with advanced chronic kidney disease (CKD), we studied the association of systolic (SBP) and diastolic blood pressure (DBP) with decline in renal function and time until the start of renal replacement therapy (RRT) in patients with CKD stages IV-V on pre-dialysis care.

Methods

In the PREPARE-1 cohort 547 incident pre-dialysis patients, referred as part of the usual care to outpatient clinics of eight Dutch hospitals, were included between 1999 and 2001 and followed until the start of RRT, mortality, or end of follow-up (January 1^st 2008). Main outcomes were rate of decline in renal function, estimated as the slope of available eGFR measurements, and time until the start of RRT.

Results

A total of 508 patients, 57% men and median (IQR) age of 63 (50-73) years, were available for analyses. Mean (SD) decline in renal function was 0.35 (0.75) ml/min/1.73 m²/month. Every 10 mmHg increase in SBP or DBP resulted in an accelerated decline in renal function (adjusted additional decline 0.04 (0.02;0.07) and 0.05 (0.00;0.11) ml/min/1.73 m²/month respectively) and an earlier start of RRT (adjusted HR 1.09 (1.04;1.14) and 1.16 (1.05;1.28) respectively). Furthermore, patients with SBP and DBP above the BP target goal of < 130/80 mmHg experienced a faster decline in renal function (adjusted additional decline 0.31 (0.08;0.53) ml/min/1.73 m²/month) and an earlier start of RRT (adjusted HR 2.08 (1.25;3.44)), compared to patients who achieved the target goal (11%). Comparing the decline in renal function and risk of starting RRT between patients with only SBP above the target (≥ 130 mmHg) and patients with both SBP and DBP below the target (< 130/80 mmHg), showed that the results were almost similar as compared to patients with both SBP and DBP above the target (adjusted additional decline 0.31 (0.04;0.58) ml/min/1.73 m²/month and adjusted HR 2.24 (1.26;3.97)). Therefore, it seems that especially having SBP above the target is harmful.

Conclusions

In pre-dialysis patients with CKD stages IV-V, having blood pressure (especially SBP) above the target goal for CKD patients (< 130/80 mmHg) was associated with a faster decline in renal function and a later start of RRT.

Impact of arterial stiffness on adverse cardiovascular outcomes and mortality in peritoneal dialysis patients

BACKGROUND

Cardiovascular (CV) disease is a major cause of morbidity and mortality in patients with end-stage renal disease. In recent years, arterial stiffness has taken on great importance in the pathophysiology of CV diseases. The independent predictive value of arterial stiffness for CV events and for all-cause and CV mortality has been demonstrated in the general population and in hemodialysis patients. Our aim in this study was to determine the relationship of arterial stiffness with mortality and fatal and nonfatal CV events in peritoneal dialysis (PD) patients.

METHODS

In this prospective observational cohort study with 2 years of follow-up, we studied a cohort of 156 PD patients with a mean follow-up of 19.2 ± 6.4 months. At baseline, echocardiography and standard clinical and biochemical analyses were performed in all patients and in 28 healthy subjects. Aortic stiffness index beta (ASIβ, a surrogate marker of arterial stiffness) was calculated as follows: ASIβ = ln (systolic blood pressure / diastolic blood pressure) / [(systolic diameter – diastolic diameter) / diastolic diameter].

RESULTS

During the follow-up period, 25 of the patients (16.0%) died, and 10 of those deaths had CV causes. Nonfatal CV events occurred in 15 patients. The median ASIβ was greater in PD patients than in control subjects (4.2 vs. 3.5; interquartile range: 3.2 - 5.5 vs. 2.5 - 4.8; p = 0.028]. In the fully adjusted multivariate Cox regression analysis (co-variates: age, sex, albumin, hemoglobin, diabetes mellitus, comorbid CV disease, left ventricular mass index, residual glomerular filtration rate, dialysate-to-plasma ratio of creatinine, Kt/V urea, left ventricular ejection fraction, duration of dialysis, smoking), ASIβ independently predicted fatal and nonfatal CV events (hazard ratio: 1.239; 95% confidence interval: 1.103 to 1.392), but not all-cause mortality.

CONCLUSIONS

Our results provide the first direct evidence that arterial stiffness is an independent risk predictor of adverse CV outcome in PD patients.

Evolution of arterial stiffness after kidney transplantation

BACKGROUND

Increased arterial stiffness (AS) is a major determinant of cardiovascular complications in end-stage renal disease (ESRD) patients. Little is known about AS evolution after kidney transplantation. The aim of the study was to characterize the evolution of AS after kidney transplantation in a population of ESRD patients, in comparison to those remaining in dialysis.

METHODS

Eighty-eight patients (age between 35 and 65) were recruited from the waiting list for kidney transplantation of the University Hospital of Nancy. Two vascular evaluations were performed at a 1-year interval. During this interval, 39 patients were transplanted and 49 remained in dialysis.

RESULTS

At inclusion, median pulse-wave velocity (PWV) was similar in transplanted patients and transplantation-pending patients, respectively, 9.2 (7.9-11.9) and 9.8 (7.7-12.1) m/s. No difference between the two groups was found at the 1-year interval. Median of time after transplantation was 6.3 (3.8-10.1) months. Median of blood pressure (MBP) decreased only in the transplanted patients [99 (93-112) versus 96 (90-101) mmHg, P < 0.01] Multivariate analysis showed that PWV changes depend on changes in MBP and baseline PWV.

CONCLUSION

Although no difference in the 1-year PWV evolution was found, the low MBP value in transplanted patients allow to expect a better long-term evolution of AS and a better cardiovascular prognosis after kidney transplantation than in transplantation-pending patients.

Blood pressure and not uraemia is the major determinant of arterial stiffness and endothelial dysfunction in patients with chronic kidney disease and minimal co-morbidity

INTRODUCTION

Patients with chronic kidney disease (CKD) have increased risk of cardiovascular disease to which co-morbidity and associated conventional risk factors contribute. We hypothesised that arterial stiffness (AS) and endothelial dysfunction (ED), as surrogates of cardiovascular risk, would worsen as renal function declined even in patients without co-morbidity and that this would relate to emerging cardiovascular risk factors.

METHODS

Carotid-femoral pulse wave velocity (PWV), as a measure of AS, and flow-mediated dilatation (FMD) of the brachial artery, as a measure of ED, were assessed in CKD patients without established cardiovascular disease or diabetes mellitus.

RESULTS

PWV increased linearly as renal function declined (r(2) = 0.08, p < 0.01) whereas FMD was reduced only in patients with advanced kidney disease. In multivariable analysis, blood pressure was the major determinant of PWV and FMD. High-sensitivity C-reactive protein and asymmetric dimethylarginine, and isoprostanes and endothelin-1, were independent predictors of PWV and FMD, respectively. However, renal function did not independently predict either AS or ED.

CONCLUSIONS

These findings suggest that declining renal function, in the absence of significant co-morbidity, is associated with progressive arterial stiffness, but only patients close to dialysis exhibit endothelial dysfunction. Whilst blood pressure remains the major determinant of PWV and FMD, inflammation, oxidative stress and endothelin-nitric oxide balance contribute to cardiovascular risk, in this non-comorbid cohort.