Accelerated atherosclerosis in prolonged maintenance hemodialysis

Beyond prevalence: significance and differential impact of echocardiographic abnormalities in dialysis patients

BACKGROUND

Echocardiography is commonly used to assess hydratation status and cardiac function in kidney failure patients, but the impact of structural or functional abnormalities on the prognosis of kidney failure patients was yet to be investigated. This study aimed to investigate the prevalence and clinical significance of echocardiographic abnormalities in kidney failure patients.

METHODS

This study included 857 kidney failure patients who underwent echocardiography at dialysis initiation. Patients were followed up for a median of 4.2 years for the occurrence of major adverse cardiovascular events (MACE) and all-cause mortality.

RESULTS

Among the 857 patients studied, 77% exhibited at least one echocardiographic abnormality. The most common abnormalities were left ventricular hypertrophy and left atrial enlargement, but they were not significantly correlated with poor outcomes. Instead, the primary predictors of both major adverse cardiovascular events and mortality in kidney failure patients were left ventricular systolic function, right ventricular systolic function, left ventricular volume index, and valvular abnormalities. Although diastolic dysfunction was linked to major adverse cardiovascular events, it was not associated with mortality. Furthermore, the study revealed that increased left ventricular volume index and left ventricular systolic dysfunction had a more significant impact on peritoneal dialysis (PD) patients than on hemodialysis (HD) patients.

CONCLUSION

This study provides insights into the echocardiographic abnormalities and their association with adverse outcomes in kidney failure patients, which can help clinicians optimize the management of patients and closely monitor possible high-risk populations.

IL-6 inhibition with clazakizumab in patients receiving maintenance dialysis: a randomized phase 2b trial

Inflammation mediated by interleukin-6 (IL-6) is strongly associated with cardiovascular risk. Here we evaluated clazakizumab, a monoclonal antibody targeting the IL-6 ligand, in a phase 2b dose-finding study. Adults with cardiovascular disease and/or diabetes receiving maintenance dialysis with high-sensitivity C-reactive protein (hs-CRP) ≥ 2 mg l-1 at baseline were randomized to receive clazakizumab (2.5 mg, 5 mg or 10 mg, n = 32 per dose group) or placebo (n = 31) every 4 weeks. The primary endpoint was the change from baseline in hs-CRP to week 12, expressed as the geometric mean ratio. Clazakizumab treatment signficantly reduced serum hs-CRP concentrations at week 12 by 86%, 90% and 92% relative to placebo in patients randomized to 2.5 mg, 5 mg or 10 mg clazakizumab, respectively (all P < 0.0001), meeting the primary outcome. With regard to secondary endpoints, clazakizumab treatment reduced serum fibrinogen, amyloid A, secretory phospholipase A2, and lipoprotein(a) concentrations, as well as increased mean serum albumin concentrations at 12 weeks, relative to placebo. The proportion of patients who achieved hs-CRP < 2.0 mg l-1 was 79%, 82% and 79% in the 2.5 mg, 5 mg and 10 mg clazakizumab groups, respectively, compared with 0% of placebo-treated patients. With regard to safety, no cases of sustained grade 3 or 4 thrombocytopenia or neutropenia were observed. Serious infections were seen with similar frequency in the placebo, clazakizumab 2.5 mg and clazakizumab 5 mg groups, but were numerically more frequent in the clazakizumab 10 mg group. The results of this trial indicate that in patients receiving maintenance dialysis, clazakizumab reduced inflammatory biomarkers associated with cardiovascular events. ClinicalTrials.gov registration: NCT05485961 .

A Historical Perspective on Uremia and Uremic Toxins

Uremia, also known as uremic syndrome, refers to the clinical symptoms in the final stage of renal failure. The definition of the term has changed over time due to an improved comprehension of the kidney's function and the advancement of dialysis technology. Here, we aim to present an overview of the various concepts that have developed regarding uremia throughout the years. We provide a comprehensive review of the historical progression starting from the early days of Kolff and his predecessors, continuing with the initial research conducted by Niwa et al., and culminating in the remote sensing hypothesis of Nigam. Additionally, we explore the subsequent investigation into the function of these toxins as signaling molecules in various somatic cells.

Sex Differences in Cardiovascular Outcomes in Patients With Kidney Failure

BACKGROUND

Cardiovascular disease is the leading cause of mortality in patients with kidney failure, and their risk of cardiovascular events is 10 to 20 times higher as compared with the general population.

METHODS AND RESULTS

We evaluated 508 822 patients who initiated dialysis between January 1, 2005 and December 31, 2014 using the United States Renal Data System with linked Medicare claims. We determined hospitalization rates for cardiovascular events, defined by acute coronary syndrome, heart failure, and stroke. We examined the association of sex with outcome of cardiovascular events, cardiovascular death, and all-cause death using adjusted time-to-event models. The mean age was 70±12 years and 44.7% were women. The cardiovascular event rate was 232 per thousand person-years (95% CI, 231-233), with a higher rate in women than in men (248 per thousand person-years [95% CI, 247-250] versus 219 per thousand person-years [95% CI, 217-220]). Women had a 14% higher risk of cardiovascular events than men (hazard ratio [HR], 1.14 [95% CI, 1.13-1.16]). Women had a 16% higher risk of heart failure (HR, 1.16 [95% CI, 1.15-1.18]), a 31% higher risk of stroke (HR, 1.31 [95% CI, 1.28-1.34]), and no difference in risk of acute coronary syndrome (HR, 1.01 [95% CI, 0.99-1.03]). Women had a lower risk of cardiovascular death (HR, 0.89 [95% CI, 0.88-0.90]) and a lower risk of all-cause death than men (HR, 0.96 [95% CI, 0.95-0.97]).

CONCLUSIONS

Among patients undergoing dialysis, women have a higher risk of cardiovascular events of heart failure and stroke than men. Women have a lower adjusted risk of cardiovascular mortality and all-cause mortality.

Update on Hemodialysis-Induced Multiorgan Ischemia: Brains and Beyond

Hemodialysis is a life-saving treatment for patients with kidney failure. However, patients requiring hemodialysis have a 10-20 times higher risk of cardiovascular morbidity and mortality than that of the general population. Patients encounter complications such as episodic intradialytic hypotension, abnormal perfusion to critical organs (heart, brain, liver, and kidney), and damage to vulnerable vascular beds. Recurrent conventional hemodialysis exposes patients to multiple episodes of circulatory stress, exacerbating and being aggravated by microvascular endothelial dysfunction. This promulgates progressive injury that leads to irreversible multiorgan injury and the well-documented higher incidence of cardiovascular disease and premature death. This review aims to examine the underlying pathophysiology of hemodialysis-related vascular injury and consider a range of therapeutic approaches to improving outcomes set within this evolved rubric.‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬.

Predictors of functional impairment and mortality in patients on maintenance hemodialysis

INTRODUCTION

Numerous factors impact the mortality and functional abilities of patients with end-stage renal disease (ESRD) receiving maintenance hemodialysis (MHD). We aimed to determine the mortality rate at 1 year of MHD, identify predictors of mortality, and assess functional impairments concerning activities of daily living (ADLs) and instrumental ADL (IADL).

METHODS

Our study was prospective, observational cohort study that enrolled patients receiving MHD. We collected demographic, clinical, and laboratory data. We also assessed ADLs and IADLs for daily performance.

RESULTS

Our study included 167 patients with a mean age of 51.6 ± 13.1 years, and 56.9% were male. Of these, 80 (47.9%) were diabetic, and 145 (86.8%) were hypertensive. The mortality rate after 1 year of MHD was 10.8%, and cardiovascular causes accounted for over 70% of total deaths. Sudden cardiac death was the most frequent cause (38.9%), followed by cardiogenic shock (22.2%). Older age and low parathormone levels (<300 pg/mL) were significantly associated with higher mortality rates. Mean ADL and IADL scores were 4.5 ± 1.3 and 6.3 ± 2.7, respectively. Eighteen (10.8%) and 56 (33.5%) patients had low ADL and IADL scores, respectively. Although statistically insignificant, a higher proportion of non-survivors exhibited low IADL and ADL scores. Older age, longer diabetes duration, and higher BMI levels were significantly associated with lower IADL scores.

CONCLUSIONS

Older age and suppressed PTH levels are predictors of mortality in ESRD patients receiving MHD. These patients require regular follow-ups to rule out cardiovascular morbidity. Functional impairment is prevalent but remains underdiagnosed in MHD patients. It should be monitored regularly to improve quality of life in ESRD.

Knowledge of arteriovenous fistula care in patients with end-stage kidney disease in south Asian countries: A systematic review and meta-analysis

OBJECTIVES

To find the prevalence of knowledge of arteriovenous fistula (AVF) self-care, its characteristics, and associated factors among hemodialysis patients and summarize the findings of various domains of AVF self-care in south Asian countries.

METHODS

The systematic literature search was performed on online databases and additional sources to retrieve published articles on AVF self-care. We estimated the pooled prevalence using a random effects model in meta-analysis. Additionally, thematic knowledge regarding various aspects of AVF self-care was narratively summarized.

RESULTS

Among the articles retrieved seven studies met our inclusion and exclusion criteria. The prevalence of AVF self-care in individual studies ranged from 59% to 99%, with an overall random pooled prevalence of 81% (95% CI, 68% to 94%). Major factors associated with self-care of AVF knowledge included patients' educational status, age, vintage of hemodialysis, and healthcare personnel's advice.

DISCUSSION

Knowledge scarcity regarding potential measures of AVF self-care obligates the need for continuous education in hemodialysis patients. A multidisciplinary approach is vital to enhance self-care from pre- to post-creation of AVF in hemodialysis patients as well as their caregivers in order to prolong the patency rates and decrease the subsequent morbidity and mortality due to failure of AVF.

External validation of the SYNTAX score II 2020 in patients with chronic renal insufficiency

BACKGROUND

The SYNTAX score Ⅱ 2020 (SSⅡ-2020) was created as a customized decision-making tool for individuals diagnosed with complex coronary artery disease (CAD). Nevertheless, there has been a scarcity of research investigating the long-term predictive significance of SSⅡ-2020 for patients with both CAD and chronic renal insufficiency (CRI) who undergo percutaneous coronary intervention (PCI).

AIMS

We sought to showcase the prognostic capacity of SSII-2020 in evaluating long-term all-cause mortality (ACM) within this high-risk patient cohort.

METHODS

A retrospective cohort comprising 1156 individuals diagnosed with CRI and exhibiting left main CAD, three-vessel CAD or both was included in this investigation. We categorized participants into three groups based on the optimal SSII-2020 threshold for predicting long-term ACM, determined using the X-tile software.

RESULTS

At the median follow-up duration of 6.3 years, the ACM rates were determined to be 10% in the low, 17% in the moderate, and 28% in the high SSII-2020 groups (p < 0.001). Employing multivariate Cox regression analysis, it was observed that the high SSII-2020 group exhibited a 3.289-fold increased risk of ACM (95% confidence interval [CI]: 2.229-4.856, p < 0.001) compared with the low SSII-2020 group, whereas the high SSII-2020 group displayed a 1.757-fold (95% CI: 1.190-2.597, p = 0.005) in comparison to the median SSII-2020 groups. Compared with SSII, the SSII-2020 had an incremental value for predicting 7-year ACM (C-index: 0.662 vs. 0.534, p = 0.007; IDI: 0.016, p < 0.001).

CONCLUSIONS

SSII-2020 enhances long-term ACM prediction, facilitates improved risk stratification, and improves clinical utility for PCI patients with complex CAD and CRI.

Antihypertensive treatment of end-stage renal disease patients on hemodialysis does not alter circulating ACE and ACE2 activity and angiotensin peptides

Cardiovascular diseases (CVD) are the main causes of death in hemodialysis patients, representing a public health challenge. We investigated the effect of different antihypertensive treatments on circulating levels of renin-angiotensin system (RAS) components in end-stage renal disease (ESRD) patients on hemodialysis. ESRD patients were grouped following the prescribed antihypertensive drugs: ß-blocker, ß-blocker+ACEi and ß-blocker+AT1R blocker. ESDR patients under no antihypertensive drug treatment were used as controls. Blood samples were collected before hemodialysis sessions. Enzymatic activities of the angiotensin-converting enzymes ACE and ACE2 were measured through fluorescence assays and plasma concentrations of the peptides Angiotensin II (Ang II) and Angiotensin-(1-7) [Ang-(1-7)] were quantified using mass spectrometry (LC-MS/MS). ACE activity was decreased only in the ß-blocker+ACEi group compared to the ß-blocker+AT1R, while ACE2 activity did not change according to the antihypertensive treatment. Both Ang II and Ang-(1-7) levels also did not change according to the antihypertensive treatment. We concluded that the treatment of ESRD patients on hemodialysis with different antihypertensive drugs do not alter the circulating levels of RAS components.

Hemodiafiltration with endogenous reinfusion of the regenerated ultrafiltrate (HFR): towards a convective, diffusive, and adsorptive dialysis

Hemodiafiltration with endogenous reinfusion of the ultrafiltrate (HFR) is a dialysis technique characterized by a resin cartridge with adsorptive properties that combines the mechanisms of diffusion, convection, and adsorption in a single therapeutic regimen. After nearly 20 years of clinical experience with HFR, this article reviews the accumulated evidence with this technique, considering whether adsorption reduction, as a third purification mechanism, should be the next step in the treatment of hemodialysis patients. HFR, beyond producing an extensive removal of uremic toxins, has demonstrated to reduce the loss of nutrients and other physiological components during the dialysis session as compared to online hemodiafiltration, ameliorating the inflammatory state and oxidative stress in this population. In addition to its ease of use, the technique is also highly biocompatible and can be used in patients with a compromised vascular access. Based on these observations, HFR appears to be an especially useful therapy for high-comorbidity patients, including those with frailty, malnutrition, or cardiovascular disease. In this review, we, as a consensus panel of nephrologists experienced with HFR, survey existing literature and summarize our views on when to use this technique, which patients may be best suited for HFR, and how to effectively prescribe and monitor this modality of dialysis in daily clinical practice.

Can Erectile Dysfunction Severity Predict Major Adverse Cardiovascular Events in Men Undergoing Dialysis? A Prospective Cohort Study

PURPOSE

To evaluate the impact of severe erectile dysfunction (ED) on future major adverse cardiovascular events (MACE) in men on dialysis.

MATERIALS AND METHODS

This prospective cohort study included 71 men on dialysis. ED was assessed using the Sexual Health Inventory for Men (SHIM). Men were divided into the mild/moderate ED (SHIM score ≥8) and severe ED (SHIM score ≤7) groups. The primary endpoint was MACE-free survival. MACE was a composite of myocardial infarction, cardiovascular death, and stroke. The secondary endpoints were cardiac event-free survival and overall survival (OS). Moreover, the predictive abilities of severe ED for 5-year MACE, 5-year cardiac events, and 5-year overall mortality were evaluated.

RESULTS

The median age and follow-up period of the included men were 64 years and 58 months, respectively. The median SHIM score was 4.0; all had a degree of ED, and 64.7% had severe ED. In the background-adjusted multivariable analyses, severe ED was not significantly associated with shorter MACE-free survival (hazard ratio [HR], 1.890; 95% confidence interval [CI], 0.533-6.706; p=0.324), cardiac event-free survival (HR, 2.081; 95% CI, 0.687-6.304; p=0.195), and OS (HR, 0.817; 95% CI, 0.358-1.863; p=0.630). Severe ED did not significantly improve the predictive abilities for 5-year MACE, 5-year cardiac events, and 5-year overall mortality (p=0.110, p=0.101, and p=0.740, respectively).

CONCLUSIONS

ED severity was not associated with shorter MACE-free survival, cardiac event-free survival, or OS, and ED severity could not improve the predictive abilities for these outcomes in men undergoing dialysis.

Cardiovascular Consequences of Acute Kidney Injury: Treatment Options

Soon after haemodialysis was introduced into clinical practice, a high risk of cardiac death was noted in end-stage renal disease. However, only in the last decade has it become clear that any renal injury, acute or chronic, is associated with high overall and cardiovascular lethality. The need for early recognition of kidney damage in cardiovascular pathology to assess risk and develop tactics for patient management contributed to the emergence of the concept of the "cardiorenal syndrome" (CRS). CRS is a pathophysiological disorder of the heart and kidneys in which acute or chronic dysfunction of one of these organs leads to acute or chronic dysfunction of the other. The beneficial effect of ultrafiltration as a component of renal replacement therapy (RRT) is due to the elimination of hyperhydration, which ultimately affects the improvement in cardiac contractile function. This review considers the theoretical background, current status of CRS, and future potential of RRT, focusing on the benefits of ultrafiltration as a therapeutic option.

[Cardiorenal syndromes: historical aspects and current challenges]

The article describes major milestones in acknowledgment of pathophysiological relationship between heart and kidneys since Ancient Egypt till our time and history of term "cardiorenal syndrome" (CRS). First references about kidney and heart functions could be dated to 13 BC when Hippocrates mentioned them. In the XIV century Gentile da Foligno proposed a hypothesis about functional interconnection between heart and kidneys. In the XVIII century Richard Bright described the link between myocardial hypertrophy and kidneys diseases. Frederic Justin Collet was the first one who used the term "cardiorenal" in his article in 1903. In Russia, I.I. Stolnikov conducted his experiments about myocardial hypertrophy and kidneys ischemia in 1880. Famous Russian internist, E.M. Tareev, devoted several paragraphs to cardiorenal interactions in his fundamental manuals "Anemia in Bright's disease" (1929) and "Hypertension" (1948). The research on this topic was continued by Tareev's followers: N.A. Mukhin, V.S. Moiseev, more recent successors - Zh.D. Kobalava, S.V. Moiseev, V.V. Fomin, S.V. Villevalde and others. Their contribution resulted in development of first Russian clinical guidelines on cardio and nephroprotection in CRS in 2014. In 2008 consensus of Acute Disease Quality Initiative summarized current experience on CRS. Today, research on controversial classification questions, biomarkers and other aspects of CRS continues.

Acute coronary syndromes in chronic hemodialysis patients: a series of 34 cases (case series)

Cardiovascular diseases, particularly acute coronary syndrome, are the leading cause of death in chronic hemodialysis patients. Our study aims to analyze the pathophysiological, clinical, angiographic, and therapeutic characteristics of coronary heart disease in hemodialysis patients.

PATIENTS AND METHODS

This single-centered retrospective descriptive study included 34 hemodialysis patients hospitalized in the cardiovascular ICU.

RESULTS

The mean age of patients in our study was 64.4±11.3 years. The main cardiovascular risk factor found in our study was age, with a prevalence of 76.50%, followed by hypertension, with a prevalence of 67.60%. Diabetes was present in 55.90% of patients. The authors also found that 17.90% of patients were obese, and 29.40% had abdominal obesity. The main cause of renal disease in our study was diabetic nephropathy (52.90% of cases), followed by hypertensive nephropathy (23.50% of cases). ST segment elevation myocardial infarction was found in 14.70% of cases, and non-ST-segment elevation myocardial infarction in 85.30% of cases. Coronary angiography was performed in 76.40% of patients. Single-vessel coronary artery disease (CAD) was found in 20%, two-vessel CAD in 50%, and three-vessel CAD in 30% of the cases. Coronary artery calcifications were observed in 21.42% of cases. 38.23% had an angioplasty, and 20.58% were referred for a coronary artery bypass graft.

CONCLUSION

Despite the high mortality rate after acute coronary syndrome, hemodialysis patients are less likely to undergo diagnostic angiography or coronary revascularization. Patients on hemodialysis tend to have multiple, diffuse, calcified CAD.

Major cardiovascular events and associated factors among routine hemodialysis patients with end-stage renal disease at tertiary care hospital in Somalia

Introduction

Cardiovascular complications are the most significant cause of death in patients undergoing routine hemodialysi (HD) with end-stage renal disease (ESRD). The main objective of this study is to determine the significant cardiac events and risk factors in patients undergoing routine hemodialysis in Somalia.

Methods

We carried out a cross-sectional retrospective study in a single dialysis center in Somalia. Two hundred out of 224 were included. All of them had ESRD and were on hemodialysis during the study period between May and October 2021. The records of all patients were reviewed, and the following parameters were analyzed socio-demographic factors, risk factors for cardiovascular disease, and the presence of cardiovascular diseases.

Results

The mean age was 54 ± 17.5 years (range 18-88 years), and 106 (53%) patients were males. The prevalence of a cardiovascular disease among hemodialysis patients was 29.5%. Moreover, the distribution of cardiovascular diseases was different; heart failure was the most common, about 27.1%, followed by coronary artery disease (17%), pericarditis and pericardial-effusion (13.6%), dysrhythmia (10.2%), cerebrovascular-accident (8.5%), and peripheral vascular disease (3.4%). About 176 (88%) participants had at least one modifiable cardiovascular risk factor. The most common modifiable cardiovascular risk factor was hypertension (n = 45, 25.1%), followed by anemia (n = 28, 15.6%) and diabetes (n = 26, 14.5%). Younger (18-30) participants were six times less likely to have cardiovascular events among hemodialysis than older age 0.4 (0.11-1.12).

Conclusion

Low prevalence rate of cardiovascular complications was confirmed in ESRD patients receiving hemodialysis in the main HD center in Somalia. Diabetes, anemia, and hypertension were the highest significant risk factors for CVD in HD patients with ESRD in Somalia.

Probing the Association between Acute Kidney Injury and Cardiovascular Outcomes

BACKGROUND

Patients hospitalized with AKI have higher subsequent risks of heart failure, atherosclerotic cardiovascular events, and mortality than their counterparts without AKI, but these higher risks may be due to differences in prehospitalization patient characteristics, including the baseline level of estimated glomerular filtration rate (eGFR), the rate of prior eGFR decline, and the proteinuria level, rather than AKI itself.

METHODS

Among 2177 adult participants in the Chronic Renal Insufficiency Cohort study who were hospitalized in 2013-2019, we compared subsequent risks of heart failure, atherosclerotic cardiovascular events, and mortality between those with serum creatinine-based AKI (495 patients) and those without AKI (1682 patients). We report both crude associations and associations sequentially adjusted for prehospitalization characteristics including eGFR, eGFR slope, and urine protein-creatinine ratio (UPCR).

RESULTS

Compared with patients hospitalized without AKI, those with hospitalized AKI had lower eGFR prehospitalization (42 versus 49 ml/min per 1.73 m 2 ), faster chronic loss of eGFR prehospitalization (-0.84 versus -0.51 ml/min per 1.73 m 2 per year), and more proteinuria prehospitalization (UPCR 0.28 versus 0.16 g/g); they also had higher prehospitalization systolic BP (130 versus 127 mm Hg; P < 0.01 for all comparisons). Adjustment for prehospitalization patient characteristics attenuated associations between AKI and all three outcomes, but AKI remained an independent risk factor. Attenuation of risk was similar after adjustment for absolute eGFR, eGFR slope, or proteinuria, individually or in combination.

CONCLUSIONS

Prehospitalization variables including eGFR, eGFR slope, and proteinuria confounded associations between AKI and adverse cardiovascular outcomes, but these associations remained significant after adjusting for prehospitalization variables.

Association between Aortic Calcification Burden and the Severity of Erectile Dysfunction in Men Undergoing Dialysis: A Cross-Sectional Study

PURPOSE

Accelerated atherosclerosis is a major complication in patients with end-stage renal disease and it plays an important role in the pathogenesis of erectile dysfunction (ED). However, the association between aortic calcification burden and the severity of ED remains unclear. The aim of the present study was to investigate this association in men undergoing dialysis.

MATERIALS AND METHODS

This cross-sectional study included 71 men undergoing peritoneal dialysis and/or hemodialysis between July 2016 and May 2018 at Mutsu General Hospital. ED was assessed with the Sexual Health Inventory for Men (SHIM). Patients were divided into the mild/moderate (SHIM score ≥8) and severe ED groups (SHIM score ≤7). Aortic calcification index (ACI) was examined as a clinical indicator of abdominal aortic calcification. Multivariable logistic regression analysis was performed to identify the significant factors associated with severe ED.

RESULTS

The median age of the study participants was 64 years; all had ED, with 64.8% having severe ED. In the multivariable analyses, a slight association was observed between ankle-brachial index and severe ED (odds ratio [OR], 0.058; p=0.072), whereas ACI was significantly associated with severe ED (OR, 1.022; p=0.022).

CONCLUSIONS

Aortic calcification burden was independently associated with severe ED.

Carotid–Femoral Pulse Wave Velocity Could Be a Marker to Predict Cardiovascular and All-Cause Mortality of Hemodialysis Patients

Among hemodialysis (HD) patients, cardiovascular disease (CVD) is recognized as a major contributor to the high risk of mortality, and emerging evidence has ascertained arterial stiffness as an independent predictor of adverse cardiovascular (CV) outcomes. We aimed to investigate the efficacy of arterial stiffness measurement in predicting CV and all-cause mortality in patients on HD (n = 130). Carotid–femoral pulse wave velocity (cfPWV) was measured by a validated tonometry system. A cfPWV of >10 m/s was used to assign patients to the arterial stiffness group (n = 64). Baseline and biochemical characteristics, as well as all-cause and CV mortality, were recorded. During the 3-year follow-up period, a total of 32 deaths (25%) occurred. The patients who died had clinically significant high cfPWV levels; were relatively old; and had hypoalbuminemia, low creatinine levels, and diabetes. After adjustment for the prognostic variables, patients with elevated cfPWV had significantly higher all-cause (p = 0.036) and CV mortality (p = 0.017), compared with the mortality rates in the normal group. In this study, cfPWV was found to be an independent predictor of all-cause and CV mortality in HD patients.

Kidney transplantation following iliac revascularization in severe atherosclerosis: a comparative study

BACKGROUND

Kidney transplantation (KT) has become the standard of care for patients with end-stage renal disease. However, as atherosclerosis progresses with time on dialysis, it causes increasing difficulties in implanting the graft. This is a comparative study analyzing complications and graft survival of recipients with iliac revascularization before transplantation.

METHODS

Between January 2006 and December 2015, 1691 kidney transplants were performed at our institution. We retrospectively analyzed eighteen patients with peripheral arterial disease (PAD) with the necessity of vascular revascularization before kidney transplantation to protect the inflow to the renal graft and to optimizing blood supply to the extremities. The primary endpoint included patient survival and graft survival. The secondary endpoints evaluate perioperative and early postoperative complication rates after kidney transplantation.

RESULTS

All patients enrolled in this study underwent two consecutive surgical procedures. No patient reported limb loss, and there was no additional perioperative morbidity or mortality related to the vascular procedure. Primary endpoints such as graft survival without dialysis and overall patient survival show 1-month survival of 100%, 1-year survival of 94.1%, and 5-year survival of 84.70%, respectively. One graft failure occurred 8 months after transplantation due to acute rejection, and there were two deaths over follow-up period due to myocardial infarction.

CONCLUSIONS

Vascular repair before kidney transplantation is safe, and results are suggestive that it prolongs graft survival. These promising results should encourage other centers to address vascular repair before the transplantation to optimize blood supply to the extremity and the future graft. Although, the interpretation of our results must be cautiously because of the small and heterogeneous sample size, and the limitations of retrospective study design. Prospective trials with larger study populations are needed to confirm the results of this study and to identify significant differences.

Impact of Arterial Calcification of the Lower Limbs on Long-Term Clinical Outcomes in Patients on Hemodialysis

Lower limbs' arterial calcification is significantly associated with the clinical severity of lower extremity artery disease (LEAD) in patients undergoing hemodialysis (HD). However, the association between arterial calcification of the lower limbs and long-term clinical outcomes in patients on HD has not been elucidated. Calcification scores of the superficial femoral artery (SFACS) and below-knee arteries (BKACS) were quantitatively evaluated in 97 HD patients who were followed for 10 years. Clinical outcomes, including all-cause and cardiovascular mortality, cardiovascular events, and limb amputation were evaluated. Risk factors for clinical outcomes were evaluated using univariate and multivariate Cox proportional hazard analyses. Furthermore, SFACS and BKACS were divided into three groups (low, middle, and high), and their associations with clinical outcomes were evaluated using Kaplan-Meier analysis. SFACS, BKACS, C-reactive protein, serum albumin, age, diabetes, presence of ischemic heart disease, and critical limb-threatening ischemia were significantly associated with 3-year and 10-year clinical outcomes in the univariate analysis. Multivariate analysis showed that SFACS was an independent factor associated with 10-year cardiovascular events and limb amputations. Kaplan-Meier life table analysis showed that higher SFACS and BKACS levels were significantly associated with cardiovascular events and mortality. In conclusion, long-term clinical outcomes and the risk factors in patients undergoing HD were evaluated. Arterial calcification of the lower limbs was strongly associated with 10-year cardiovascular events and mortality in patients undergoing HD.

Quantitative Data-Independent Acquisition Mass Spectrometry Proteomics and Weighted Correlation Network Analysis of Plasma Samples for the Discovery of Chronic Kidney Disease-Specific Atherosclerosis Risk Factors

Chronic kidney disease (CKD) accelerates atherosclerosis. The mechanism of CKD-related atherosclerosis is complex, and CKD-specific risk factors may contribute to this process in addition to traditional risk factors such as hypertension, diabetes, and hypercholesterolemia. In the present study, to discover CKD-specific atherosclerosis risk factors, a total of 62 patients with different stages of kidney function were enrolled. All patients underwent coronary angiographies and the severity of coronary atherosclerosis was defined by the SYNTAX score. Patients were divided into different groups according to their kidney function levels and coronary atherosclerosis severity. Data-independent acquisition mass spectrometry was used to identify differentially expressed proteins (DEPs) in the plasma samples, and weighted correlation network analysis (WGCNA) was employed to identify significant protein modules and hub proteins related to CKD-specific atherosclerosis. The results showed that 10 DEPs associated with atherosclerosis were found in the comparative groups with modest and severe CKD. Through WGCNA, 1768 proteins were identified and 8 protein modules were established. Enrichment analyses of protein modules revealed functional clusters mainly associated with inflammation and the complement and coagulation cascade as atherosclerosis developed under CKD conditions. The results may help to better understand the mechanisms of CKD-related atherosclerosis and guide future research on developing treatments for CKD-related atherosclerosis.

Adherence to the Mediterranean Diet Is Associated with a More Favorable Left Ventricular Geometry in Patients with End-Stage Kidney Disease

Introduction. The aim of the study was to examine the impact of adherence to a Mediterranean-style diet (MD) on left ventricular hypertrophy (LVH) and cardiac geometry in chronic kidney disease patients on dialysis (CKD-5D), given the high prevalence of cardiovascular morbidity in this population. Methods. n = 127 (77 men and 50 women) CKD-5D patients (69 on hemodialysis and 58 on peritoneal dialysis) with a mean age of 62 ± 15 years were studied. An MD adherence score (MDS) (range 0−55, 55 representing maximal adherence) was estimated with a validated method. Echocardiographic LVH was defined by LV mass index (LVMI) > 95 g/m2 in women and >115 g/m2 in men. Based on LVMI and relative wall thickness (RWT), four LV geometric patterns were defined: normal (normal LVMI and RWT), concentric remodeling (normal LVMI and increased RWT > 0.42), eccentric LVH (increased LVMI and normal RWT), and concentric LVH (increased LVMI and RWT). Results. Patients with LVH (n = 81) as compared to patients with no LVH (n = 46) were older in age (66 ± 13 vs. 55 ± 16 years; p < 0.001) had lower MDS (24 ± 2.7 vs. 25 ± 4.3; p < 0.05) and higher malnutrition-inflammation score (5.0 ± 2.7 vs. 3.9 ± 1.9; p < 0.05), body mass index (27.5 ± 4.9 vs. 24.1 ± 3.5 kg/m2; p < 0.001), prevalence of diabetes (79% vs. 20%; p < 0.05), coronary artery disease (78% vs. 20%; p < 0.05) and peripheral vascular disease (78% vs. 20%; p < 0.01). In a multivariate logistic regression analysis adjusted for all factors mentioned above, each 1-point greater MDS was associated with 18% lower odds of having LVH (OR = 0.82, 95% CI: 0.69−0.98; p < 0.05). MDS was inversely related to LVMI (r = −0.273; p = 0.02), and in a multiple linear regression model (where LVMI was analyzed as a continuous variable), MDS emerged as a significant (Β = −2.217; p < 0.01) independent predictor of LVH. Considering LV geometry, there was a progressive decrease in MDS from the normal group (25.0 ± 3.7) to concentric remodeling (25.8 ± 3.0), eccentric (24.0 ± 2.8), and then concentric (23.6 ± 2.7) group (p < 0.05 for the trend). Conclusions. The greater adherence to an MD is associated with lesser LVH, an important cardiovascular disease risk factor; MD preserves normal cardiac geometry and may confer protection against future cardiac dysfunction in dialysis patients.

The Evolving View of Uremic Toxicity

Indoxyl sulfate, closely related to indigo, a dye valued for it binding to cloth, has been recognized as a protein-bound solute bound to albumin, present in increased concentration in the serum of patients with impaired glomerular filtration (13). The early studies of Niwa identified indoxyl sulfate as a toxin capable of accelerating the rate of renal damage in subtotal nephrectomized rats (18). Over the past decade other protein-bound solutes have been identified in the plasma of patients with impaired glomerular filtration. Although the early studies, focused on the kidney, identified indoxyl sulfate as a toxic waste product dependent on the kidney for its removal, subsequent observations have identified organic anion transporters on many non-renal tissue, leading to the view that indoxyl sulfate is part of a systemic signaling system.

Robot-assisted kidney transplantation as a minimally invasive approach for kidney transplant recipients: A systematic review and meta-analyses

BACKGROUND

Robot-assisted kidney transplantation (RAKT) has emerged as an alternative for kidney transplant recipients with the potential benefits of minimally invasive surgery. The aim of this systematic review and meta-analysis is to compare the clinical outcomes of RAKT with open kidney transplantation (OKT).

METHODS

MEDLINE, Embase, Web of Science and Cochrane databases were systematically searched. Baseline characteristics, intraoperative and postoperative outcomes were collected, as well as long-term renal function and data on graft and patient survival.

RESULTS

Eleven studies were included, which compared 482 RAKT procedures with 1316 OKT procedures. RAKT was associated with lower a risk of surgical site infection (Risk ratio (RR) = 0.15, p < 0.001), symptomatic lymphocele (RR = 0.20, p = 0.03), less postoperative pain (Mean difference (MD) = -1.38 points, p < 0.001), smaller incision length (MD = -8.51 cm, p < 0.001), and shorter length of hospital stay (MD = -1.69 days, p = 0.03) compared with OKT. No difference was found in renal function, graft, and patient survival.

CONCLUSIONS

RAKT is a safe and feasible alternative to OKT with less surgical complications without compromising renal function, graft and patient survival.

Inflammation and Cardiovascular Disease Associated With Hemodialysis for End-Stage Renal Disease

Chronic kidney disease (CKD) and cardiac insufficiency often co-exist, particularly in uremic patients on hemodialysis (HD). The occurrence of abnormal renal function in patients with cardiac insufficiency is often indicative of a poor prognosis. It has long been established that in patients with cardiac insufficiency, poorer renal function tends to indicate poorer cardiac mechanics, including left atrial reserve strain, left ventricular longitudinal strain, and right ventricular free wall strain (Unger et al., Eur J Heart Fail, 2016, 18(1), 103–12). Similarly, patients with chronic kidney disease, particularly uremic patients on HD, often have cardiovascular complications in addition to abnormal endothelial function with volume overload, persistent inflammatory states, calcium overload, and imbalances in redox responses. Cardiac insufficiency due to uremia is therefore mainly due to multifaceted non-specific pathological changes rather than pure renal insufficiency. Several studies have shown that the risk of adverse cardiovascular events is greatly increased and persistent in all patients treated with HD, especially in those who have just started HD treatment. Inflammation, as an important intersection between CKD and cardiovascular disease, is involved in the development of cardiovascular complications in patients with CKD and is indicative of prognosis (Chan et al., Eur Heart J, 2021, 42(13), 1244–1253). Therefore, only by understanding the mechanisms underlying the sequential development of inflammation in CKD patients and breaking the vicious circle between inflammation-mediated renal and cardiac insufficiency is it possible to improve the prognosis of patients with end-stage renal disease (ESRD). This review highlights the mechanisms of inflammation and the oxidative stress that co-exists with inflammation in uremic patients on dialysis, as well as the mechanisms of cardiovascular complications in the inflammatory state, and provides clinical recommendations for the anti-inflammatory treatment of cardiovascular complications in such patients.

Chronic Kidney Disease, Metabolic Syndrome and Cardiovascular Risk: Insights and Associated Mechanistic Pathways

Abstract:

This study is a narrative review that aims to address the conceptual, characteristic, pathophysiological, and mechanistic aspects that define the profile of metabolic syndrome and chronic kidney disease. The objective was to investigate current knowledge and elucidate, through discussions on the topic, the main interrelated paths. This review was carried out unsystematically, from March to May 2020, by means of a survey of the literature indexed in the PubMed, Web of Science, and Scopus (Elsevier®) databases. The scientific materials collected showed that the cross-talk between the diseases in question is mainly based on the conditions of resistance to insulin action, endothelial dysfunction, activation pathways of the Renin-Angiotensin-Aldosterone system and adipokine imbalance, also emphasizing the influence of atherosclerotic events in kidney damage. Furthermore, it was reinforced the fact that inflammatory processes play an important role in the worsening and evolution of the clinical condition of patients, especially when they have underlying pathologies chronically treated for subclinical inflammation. It is expected that a greater number of original researches will propose to investigate other possible interactions, with a view to standardized treatment of these diseases or nutritional management.

Stratification Analysis of Statin Effect on Major Adverse Cardiac Events After Percutaneous Coronary Intervention in Patients on Hemodialysis

ABSTRACT

The statin use in patients on hemodialysis remains controversial, and no beneficial effects of statin on the reduction of adverse cardiovascular events have been reported in these patients. This study used stratification analysis to examine the clinical factors in patients on hemodialysis who could benefit from statin for secondary prevention. This prospective multicenter study included 234 consecutive patients on hemodialysis with coronary artery disease who underwent successful reperfusion therapy with percutaneous coronary intervention. The patients were followed up for up to 3 years or until the occurrence of major adverse cardiac events (MACEs; defined as a composite of all-cause death and nonfatal myocardial infarction). Inverse probability of treatment weighting adjustment was used to remove the selection bias. During the median follow-up period of 30 months, MACEs occurred in 55 patients. Patients with MACEs had significantly lower statin therapy (P < 0.001). Multivariable Cox proportional hazards analysis showed that the patients on statins had a significantly reduced rate of MACE occurrence [adjusted hazard ratio 0.30 (0.11-0.81), P = 0.02]. The stratification analysis of outcomes according to the presence of clinical factors showed that beneficial effects of statin were associated with man, elderly, lower body mass index, lower abdominal circumference, hypertension, diabetes, higher C-reactive protein, symptomatic heart failure, lower left ventricular function, nonacute coronary syndrome, and shorter stent length. Statin was effective for the prevention of MACEs in patients on hemodialysis who underwent percutaneous coronary intervention. We identified specific clinical factors affecting statin effectiveness for secondary prevention.

Serum Growth Differentiation Factor-15/Albumin Ratio as a 2-Year Survival Marker of End-Stage Renal Disease Patients Initiating Maintenance Hemodialysis

It is important to identify risk factors related to mortality in end-stage renal disease (ESRD) patients starting renal replacement therapy. Recently, several studies proposed that growth-differentiation factor-15 (GDF-15) is a possible biomarker for the prognosis of patients on maintenance hemodialysis. Here, we investigated the predictive value of serum GDF-15/Albumin ratio on two-year mortality in ESRD patients initiating maintenance hemodialysis. The study was a single center, retrospective study on ESRD patients starting maintenance hemodialysis with a follow-up of two years. All patients completed laboratory test and bioimpedance spectroscopy prior to the initiation of the first dialysis. The patients were stratified into quartiles according to the quartiles of serum GDF-15/Albumin ratio. Among the 159 patients, the mean age was 61.78 ± 12.52 years and median survival was 20.03 ± 7.73 months. The highest GDF-15/Albumin quartile was significantly more associated with the increased risk of all-cause mortality than other quartiles (unadjusted hazard ratio (HR): 8.468, 95% CI 2.981–24.054, p < 0.001). Older age and a higher overhydration state were associated with GDF-15/Albumin ratio. The ROC analysis confirmed that the ability of the GDF-15/Albumin ratio to predict mortality was superior to GDF-15 or albumin alone. In conclusion, the GDF-15/Albumin ratio measured at the initial maintenance hemodialysis is an independent prognostic marker of two-year mortality in ESRD patients.

Epidemiology of cardiovascular death in kidney failure: An Australian and New Zealand cohort study using data linkage

Aim

Cardiovascular mortality risk evolves over the lifespan of kidney failure (KF), as patients develop comorbid disease and transition between treatment modalities. Absolute cardiovascular death rates would help inform clinical practice and health‐care provision, but are not well understood across a continuum of dialysis and transplant states. We aimed to characterize cardiovascular death across the natural history of KF using a lifespan approach.

Methods

We performed a population‐based cohort study of incident patients commencing kidney replacement therapy in Australia and New Zealand. Cardiovascular deaths were identified using data linkage to national death registers. We estimated the probability of death and kidney transplant using multi‐state models, and calculated rates of graft failure and cardiovascular death across demographic factors and comorbidities.

Results

Among 60 823 incident patients followed over 381 874 person‐years, 25% (8492) of deaths were from cardiovascular disease. At 15 years from treatment initiation, patients had a 15.2% probability of cardiovascular death without being transplanted, but only 2.3% probability of cardiovascular death post‐transplant. Females had a 3% lower probability of cardiovascular death at 15 years (15.3% vs. 18.6%) but 4% higher probability of non‐cardiovascular death (54.5% vs. 50.8%). Within the first year of dialysis, cardiovascular mortality peaked in the second month and showed little improvement across treatment era.

Conclusion

Despite improvements over time, cardiovascular death remains common in KF, particularly among the dialysis population and in the first few months of treatment. Multi‐state models can provide absolute measures of cardiovascular mortality across both dialysis and transplant states.

In this population‐based cohort study using multi‐state models (alive without kidney transplant [KT], CV death without KT, non‐CV death without KT, alive after first KT, CV death after first KT and non‐CV death after first KT), the probability of CV death was higher in non‐KT than KT patients at 15 years from treatment. In patients on dialysis, CV mortality was highest from the second month after commencing dialysis and remained high thereafter. Thus, the use of multi‐state models provides helpful information on impacts of different treatments with respect to serious outcomes.

Predictive Effect of Renal Function on Clinical Outcomes in Older Adults With Acute Myocardial Infarction: Results From an Observational Cohort Study in China

Background: The impact of estimated glomerular filtration rate (eGFR) on the risk of death and cardiovascular events in individuals with acute myocardial infarction (AMI) is less well established, particularly in the old Chinese population. The aim of this study was to investigate the association of eGFR with clinical outcomes among older subjects with AMI. We further developed a nomogram for the prediction of 1- and 3-year survival in this population.

Methods: A cohort of 2,366 AMI subjects aged over 60 years in 2013–2020 were enrolled in the Cardiovascular Center of Beijing Friendship Hospital Database (CBD) Bank. Outcomes including cardiovascular (CV) death, all-cause death, non-fatal myocardial infarction (MI), non-fatal stroke, revascularization, and cardiac rehospitalization were collected overall and by eGFR category at baseline. eGFR was estimated by the Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI). Subjects were categorized into four groups according to quartiles of eGFR: ≤ 63.02, 63.03–78.45, 78.46–91.50, >91.51 ml/min/1.73 m². Hazard ratios (HRs), corresponding 95% confidence intervals (CIs) as well as the nomogram were assessed using Cox regression models. Validation of the nomogram was estimated by discrimination and calibration.

Results: Incidence rates and multivariable-adjusted hazard ratios of CV and all-cause death decreased significantly across quartiles of eGFR over a median follow-up time of 36.7 months. In adjusted analysis, compared with eGFR ≤ 63.02 ml/min/1.73 m², patients with eGFR of 63.03–78.45, 78.46–91.50, >91.51 ml/min/1.73 m² experienced decreased risks of CV death [respective HRs of 0.58 (95% CI, 0.38–0.90), 0.61 (95% CI, 0.38–0.99), and 0.48 (95% CI, 0.25–0.90); all p < 0.05] and all-cause death [respective HRs of 0.64 (95% CI, 0.47–0.88), 0.61 (95% CI, 0.42–0.88), and 0.54 (95% CI, 0.35–0.84); all p < 0.05]. Age, eGFR quartiles, BMI, glycated hemoglobin, LVEF, LM/multi-vessel disease, angiotensin-converting enzyme inhibitors (ACEIs), or angiotensin receptor blockers (ARBs) prescribed at discharge were associated with all-cause death. The developed model predicted 1- and 3-year probability of survival, which performed well in both discrimination and calibration.

Conclusion: In older patients with AMI, early identification of eGFR reduced and cardiovascular risks management may prevent poor clinical outcomes.

Thyroid dysfunction and insulin resistance in end-stage renal disease patients before and 1 year after starting maintenance hemodialysis: A prospective multicenter study

BACKGROUND

Thyroid dysfunction and insulin resistance (IR) are common findings in patients with ESRD. We aimed to evaluate thyroid dysfunction and IR in ESRD before and after 1 year of starting hemodialysis (HD).

METHODS

This was a prospective study that recruited newly starting HD patients who fulfilled the inclusion criteria. Patients were evaluated for TSH, free T4, free T3, fasting insulin, fasting glucose, HOMA-IR, serum ferritin, and hs-CRP levels before starting their first dialysis session and after 1 year of regular HD.

RESULTS

Eighty-one patients have completed the 1-year follow-up period. After 1 year of regular HD, there were statistically significant increments of hs-CRP, serum ferritin, and TSH levels. On the other hand, fasting insulin level and HOMA-IR showed statistically significant increments after 1 year of starting HD. After 1 year of regular HD, TSH level showed a positive correlation with hs-CRP and serum ferritin level, while free T3 was negatively correlated with HOMA-IR. On the other hand, there was a significant positive correlation between HOMA-IR, hs-CRP, and serum ferritin levels, while HOMA-IR was negatively correlated with Kt/V.

CONCLUSIONS

This study suggests overlapping complex pathogenesis of thyroid dysfunction, chronic inflammation, and IR in chronic HD patients.

Variety of Cardiac Events in Hospitalized Chronic Kidney Disease Patients

Objective This study assessed the variety and frequency of various cardiovascular events in different stages of chronic kidney disease (CKD) patients who were hospitalized due to different causes. Methods This prospective cross-sectional observational analysis was conducted at the Department of Nephrology in The Kidney Centre Post Graduate Training Institute Karachi on all adult CKD (of all stages with or without dialysis) patients, who developed cardiovascular events during their hospital admission either in ward or ICU due to any cause between August 2020 and February 2021. Total of 765 patients got admitted in the given time period and among them, 290 patients developed various cardiovascular events. Baseline data, co-morbidities, clinical features, drug history and management were determined. Results There were a total of 290 patients in our study in which 154 (53.1%) were male and 136(46.9%) were female. Mean age was 57 ± 15.5. Our majority of patients were end-stage renal disease and on maintenance hemodialysis (n=119, 41%) while the most prevalent co-morbid condition was hypertension (n=227, 78.3%) followed by diabetes mellitus (n=204, 70.4%). The most frequent cardiovascular events in CKD patients was the atrial fibrillation 101(34.8%) while 37(12.8%) patients suffered ST-elevation myocardial infarction and supraventricular tachycardia. Patients who had high potassium levels (>5.2) most frequently suffered from atrial fibrillation (n=16, 28.1%) as compared to other cardiovascular events. Conclusion Patients with CKD are at increased risk of having several cardiovascular events. Numerous risk factors involved in the pathogenesis. Among the diverse causes, fluctuations in serum levels of various electrolytes are important causes as certain electrolytes disbalance can trigger various life-threatening cardiac arrhythmias.

Risk of post-transplant cardiovascular events in kidney transplant recipients with preexisting aortoiliac stenosis

Prediction of the risk of cardiovascular events (CVE's) is important to optimize outcomes after kidney transplantation. Aortoiliac stenosis is frequently observed during pre‐transplant screening. We hypothesized that these patients are at higher risk of post‐transplant CVE's due to the joint underlying atherosclerotic disease. Therefore, we aimed to assess whether aortoiliac stenosis was associated with post‐transplant CVE's. This retrospective, single‐center cohort study included adult kidney transplant recipients, transplanted between 2000 and 2016, with contrast‐enhanced imaging available. Aortoiliac stenosis was classified according to the Trans‐Atlantic Inter‐Society Consensus (TASC) II classification and was defined as significant in case of ≥50% lumen narrowing. The primary outcome was CVE‐free survival. Eighty‐nine of 367 patients had significant aortoiliac stenosis and were found to have worse CVE‐free survival (median CVE‐free survival: stenosis 4.5 years (95% confidence interval (CI) 2.8–6.2), controls 8.9 years (95% CI 6.8–11.0); log‐rank test P < .001). TASC II C and D lesions were independent risk factors for a post‐transplant CVE with a hazard ratio of 2.15 (95% CI 1.05–4.38) and 6.56 (95% CI 2.74–15.70), respectively. Thus, kidney transplant recipients with TASC II C and D aortoiliac stenosis require extensive cardiovascular risk management pre‐, peri,‐ and post‐transplantation.

Modeling of endothelial cell dysfunction using human induced pluripotent stem cells derived from patients with end-stage renal disease

Background

Endothelial cell (EC) dysfunction is a frequent feature in patients with end-stage renal disease (ESRD). The aim of this study was to generate human induced pluripotent stem cells, differentiate ECs (hiPSC-ECs) from patients with ESRD, and appraise the usefulness of hiPSC-ECs as a model to investigate EC dysfunction.

Methods

We generated hiPSCs using peripheral blood mononuclear cells (PBMCs) isolated from three patients with ESRD and three healthy controls (HCs). Next, we differentiated hiPSC-ECs using the generated hiPSCs and assessed the expression of endothelial markers by immunofluorescence. The differentiation efficacy, EC dysfunction, and molecular signatures of EC-related genes based on microarray analysis were compared between the ESRD and HC groups.

Results

In both groups, hiPSCs and hiPSC-ECs were successfully obtained based on induced pluripotent stem cell or EC marker expression in immunofluorescence and flow cytometry. However, the efficiency of differentiation of ECs from hiPSCs was lower in the ESRD-hiPSCs than in the HC-hiPSCs. In addition, unlike HC-hiPSC-ECs, ESRD-hiPSC-ECs failed to form interconnecting branching point networks in an in vitro tube formation assay. During microarray analysis, transcripts associated with oxidative stress and inflammation were upregulated and transcripts associated with vascular development and basement membrane extracellular matrix components were downregulated in ESRD-hiPSC-ECs relative to in HC-hiPSC-ECs.

Conclusion

ESRD-hiPSC-ECs showed a greater level of EC dysfunction than HC-hiPSC-ECs did based on functional assay results and molecular profiles. hiPSC-ECs may be used as a disease model to investigate the pathophysiology of EC dysfunction in ESRD.

Top 100 cited articles on hemodialysis: A bibliometric analysis

INTRODUCTION

This study was conducted to better understand hemodialysis by reviewing the most-cited articles related to it.

METHODS

We searched articles on the Web of Science and selected the 100 most frequently cited articles. Subsequently, we reviewed these articles and identified their characteristics.

RESULTS

The 100 most frequently cited articles were published in 21 journals. The majority of these papers were published in the following journals: Kidney International (26 articles), New England Journal of Medicine (18 articles), Journal of the American Society of Nephrology (14 articles), and the American Journal of Kidney Disease (13 articles). The 100 most-cited articles were published in 25 countries. The United States of America was the country with the highest number of publications (65 articles). The University of Michigan was the institution with the highest number of articles (14 articles). FK Port was the author with the largest number of publications (13 articles).

CONCLUSIONS

This is the first study in the field of nephrology that provides a list of the 100 most-cited articles on hemodialysis. Through this study, clinicians will be able to recognize major academic interests and research trends in hemodialysis.

Serum vaspin levels and carotid intima-media thickness in predialysis patients

BACKGROUND AND OBJECTIVE

Visceral adipose tissue-derived serine proteinase inhibitor (vaspin) is an adipokine that correlates with insulin resistance and obesity in human beings. Previous studies have evaluated the serum vaspin levels in several diseases such as chronic haemodialysis patients and coronary artery disease. To our knowledge, serum vaspin levels have not yet been reported in predialysis patients. Carotid intima-media thickness (CIMT) is a noninvasive procedure to detect early atherosclerotic changes. The aim of this study was to evaluate serum vaspin levels in predialysis patients and their relationships with glomerular filtration rate and CIMT levels.

METHODS

A total of twenty-five predialysis patients (14 females and 11 males) and 22 healthy subjects (8 females and 14 males) were enrolled in the study. Serum samples were subjected to the human vaspin RIA system. CIMT was measured by B-mode ultrasonography.

RESULTS

Serum vaspin levels were significantly lower in predialysis patients than control subjects (P < .05), while CIMT levels were significantly higher (P < .001). Serum vaspin levels were found to be significantly correlated with glomerular filtration rate (r = 0.42, P < .001) and CIMT (r = -0.47, P < .05) in predialysis patients.

CONCLUSIONS

This is the first report to describe the association between serum vaspin levels and CIMT in predialysis patients. We concluded that serum vaspin levels were decreased in predialysis patients than control subjects. In addition, serum vaspin levels were found to be significantly correlated with glomerular filtration rate and CIMT.

Nonatherosclerotic Vascular Abnormalities Associated with Chronic Kidney Disease

Nonatherosclerotic vascular diseases are manifested by endothelial dysfunction, hypertension, vascular calcification, coronary microvascular dysfunction, and calciphylaxis. Unfortunately, there are no definitive treatments for many of these disorders other than hypertension. In addition, although hypertension is more difficult to treat in the chronic kidney disease population, it is necessary to try and target a blood pressure of less than 130/80 mm Hg through the use of aggressive angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, diuretics, and other antihypertensive medications. New therapies are being actively investigated in an attempt to treat nonatherosclerotic vascular diseases in the chronic kidney disease population.

Impact of Dialysis Vintage and Renal Biomarkers on Mortality in Dialysis-Dependent Patients With Critical Limb Ischemia Undergoing Revascularization

PURPOSE

Revascularization of both endovascular therapy (EVT) and surgical reconstruction improve clinical outcomes of patients with critical limb ischemia (CLI); however, treatment of dialysis-dependent patients with CLI is still challenging. This study aimed to investigate the impact of dialysis-related parameters on the risk of mortality in dialysis-dependent patients undergoing revascularization for CLI.

MATERIALS AND METHODS

We retrospectively identified 274 dialysis-dependent patients with CLI (196 males; mean age 71 years), who underwent revascularization, from the clinical database of the surgical reconstruction vs peripheral intervention in patients with critical limb ischemia (SPINACH) study, which was a prospective, multicenter, observational study. Of these patients, 175 patients underwent EVT and 99 patients received surgical reconstruction. The current study evaluated the impact of dialysis vintage and renal biomarkers on the mortality rate of dialysis-dependent patients with CLI undergoing revascularization.

RESULTS

During a mean follow-up period of 1.7 ± 1.1 years, 147 deaths were observed. The 3-year overall survival rate and its standard error were estimated to be 40.5% ± 8.1% using the Kaplan-Meier method. A Cox proportional hazard analysis revealed that dialysis vintage ≥4 years, serum creatinine levels <4.7 mg/dL, serum urea nitrogen ≥88 mg/dL, and calcium-phosphate product ≥62.6 mg²/dL² were independent risk factors for mortality after adjustment for the detailed mortality risk score developed in the SPINACH study. Adding these parameters to the original mortality risk score slightly, but not significantly, increased the area under the time-dependent receiver operating characteristics curve from 0.74 (95% CI, 0.67 to 0.81) to 0.77 (0.71 to 0.84) (p=0.084), whereas continuous net reclassification improvement reached 0.75 (0.12 to 0.90) (p=0.027).

CONCLUSION

We found that long dialysis vintage, low serum creatinine, high serum urea nitrogen, and high calcium-phosphate product were independently associated with the increased risk of mortality in dialysis-dependent patients with CLI undergoing revascularization.

Effect of Vancomycin on the Gut Microbiome and Plasma Concentrations of Gut-Derived Uremic Solutes

Introduction

Declining renal function results in the accumulation of solutes normally excreted by healthy kidneys. Data suggest that some of the protein-bound solutes mediate accelerated cardiovascular disease. Many of the poorly dialyzable protein-bound uremic retention solutes are products of gut bacterial metabolism.

Methods

We performed a blinded-randomized controlled trial comparing the changes in plasma concentrations of a panel of protein-bound solutes and microbiome structure in response to the once-weekly oral administration of 250 mg of vancomycin or placebo over a period of 12 weeks in a cohort of stable patients with end-stage kidney disease. We also examined the pattern of recovery of the solutes and gut microbiome over 12 weeks of placebo administration following vancomycin.

Results

We enrolled 15 subjects. Ten subjects provided sufficient plasma and stool samples to permit us to examine the effect of vancomycin on plasma solute levels. We showed that a weekly dose of vancomycin resulted in a reduction in the plasma concentration of 7 colon-derived solutes. We described a significant effect of vancomycin on the microbiome structure with a decrease in alpha diversity and change in beta diversity. Multiple taxa decreased with vancomycin including genera Clostridium and Bacteroides. We demonstrated microbiome recovery after stopping vancomycin. However, recovery in the solutes was highly variable between subjects.

Conclusions

We demonstrated that microbiome suppression using vancomycin resulted in changes in multiple gut-derived uremic solutes. Future studies are needed to address whether reduction in those uremic solutes results in improvement of cardiovascular outcomes in ESKD patients.

Nomenclature for kidney function and disease-executive summary and glossary from a Kidney Disease: Improving Global Outcomes (KDIGO) consensus conference

The worldwide burden of kidney disease is rising, but public awareness remains limited, underscoring the need for more effective communication by stakeholders in the kidney health community. Despite this need for clarity, the nomenclature for describing kidney function and disease lacks uniformity. In June 2019, Kidney Disease: Improving Global Outcomes (KDIGO) convened a consensus conference with the goal of standardizing and refining the nomenclature used in the English language to describe kidney function and disease, and of developing a glossary that could be used by journals in scientific publications. Guiding principles of the conference were that the revised nomenclature should be patient-centred, precise, and consistent with nomenclature used in the KDIGO guidelines. Conference attendees reached general consensus on the following recommendations: (i) to use 'kidney' rather than 'renal' or 'nephro' when referring to kidney disease and kidney function; (ii) to use 'kidney failure' with appropriate descriptions of the presence or absence of symptoms, signs, and treatment rather than 'end-stage' kidney disease; (iii) to use the KDIGO definition and classification of acute kidney diseases and disorders (AKD) and acute kidney injury (AKI) rather than alternative descriptions to define and classify the severity of AKD and AKI; (iv) to use the KDIGO definition and classification of chronic kidney disease (CKD) rather than alternative descriptions to define and classify the severity of CKD; and (v) to use specific kidney measures, such as albuminuria or decreased glomerular filtration rate, rather than 'abnormal or reduced kidney function' to describe alterations in kidney structure and function. A proposed five-part glossary contains specific items for which there was general agreement. Conference attendees acknowledged limitations of the recommendations and glossary but considered that standardizing scientific nomenclature is essential for improving communication.

Uremic Toxins in Organ Crosstalk

Many putative uremic toxins—like indoxyl sulfate, p-cresol sulfate, kynurenic acid, uric acid, and CMPF—are organic anions. Both inter-organ and inter-organismal communication are involved. For example, the gut microbiome is the main source of indole, which, after modification by liver drug metabolizing enzymes (DMEs), becomes indoxyl sulfate. Various organic anion transporters (organic anion transporters, OATs; organic anion-transporting polypeptides, OATPs; multidrug resistance-associated proteins, MRPs, and other ABC transporters like ABCG2)—often termed “drug transporters”—mediate movement of uremic toxins through cells and organs. In the kidney proximal tubule, critical roles for OAT1 and OAT3 in regulating levels of protein-bound uremic toxins have been established using knock-out mice. OATs are important in maintaining residual tubular function in chronic kidney disease (CKD); as CKD progresses, intestinal transporters like ABCG2, which extrude urate and other organic anions into the gut lumen, seem to help restore homeostasis. Uremic toxins like indoxyl sulfate also regulate signaling and metabolism, potentially affecting gene expression in extra-renal tissues as well as the kidney. Focusing on the history and evolving story of indoxyl sulfate, we discuss how uremic toxins appear to be part of an extensive “remote sensing and signaling” network—involving so-called drug transporters and drug metabolizing enzymes which modulate metabolism and signaling. This systems biology view of uremic toxins is leading to a new appreciation of uremia as partly due to disordered remote sensing and signaling mechanisms–resulting from, and causing, aberrant inter-organ (e.g., gut-liver- kidney-CNS) and inter-organismal (e.g., gut microbiome-host) communication.

Effects of chronic kidney disease and declining renal function on coronary atherosclerotic plaque progression: a PARADIGM substudy

AIMS 

To investigate the change in atherosclerotic plaque volume in patients with chronic kidney disease (CKD) and declining renal function, using coronary computed tomography angiography (CCTA).

METHODS AND RESULTS

In total, 891 participants with analysable serial CCTA and available glomerular filtration rate (GFR, derived using Cockcroft-Gault formulae) at baseline (CCTA 1) and follow-up (CCTA 2) were included. CKD was defined as GFR <60 mL/min/1.73 m2. Declining renal function was defined as ≥10% drop in GFR from the baseline. Quantitative assessment of plaque volume and composition were performed on both scans. There were 203 participants with CKD and 688 without CKD. CKD was associated with higher baseline total plaque volume, but similar plaque progression, measured by crude (57.5 ± 3.4 vs. 65.9 ± 7.7 mm3/year, P = 0.28) or annualized (17.3 ± 1.0 vs. 19.9 ± 2.0 mm3/year, P = 0.25) change in total plaque volume. There were 709 participants with stable GFR and 182 with declining GFR. Declining renal function was independently associated with plaque progression, with higher crude (54.1 ± 3.2 vs. 80.2 ± 9.0 mm3/year, P < 0.01) or annualized (16.4 ± 0.9 vs. 23.9 ± 2.6 mm3/year, P < 0.01) increase in total plaque volume. In CKD, plaque progression was driven by calcified plaques whereas in patients with declining renal function, it was driven by non-calcified plaques.

CONCLUSION

Decline in renal function was associated with more rapid plaque progression, whereas the presence of CKD was not.

Renal Replacement Modality Affects Uremic Toxins and Oxidative Stress

Nowadays, the high prevalence of kidney diseases and their related complications, including endothelial dysfunction and cardiovascular disease, represents one of the leading causes of death in patients with chronic kidney diseases. Renal failure leads to accumulation of uremic toxins, which are the main cause of oxidative stress development. The renal replacement therapy appears to be the best way to lower uremic toxin levels in patients with end-stage renal disease and reduce oxidative stress. At this moment, despite the increasing number of recognized toxins and their mechanisms of action, it is impossible to determine which of them are the most important and which cause the greatest complications. There are many different types of renal replacement therapy, but the best treatment has not been identified yet. Patients treated with diffusion methods have satisfactory clearance of small molecules, but the clearance of medium molecules appears to be insufficient, but treatment with convection methods cleans medium molecules better than small molecules. Hence, there is an urgent need of new more validated, appropriate, and reliable information not only on toxins and their role in metabolic disorders, including oxidative stress, but also on the best artificial renal replacement therapy to reduce complications and prolong the life of patients with chronic kidney disease.

Chronic kidney disease, atherosclerotic plaque characteristics on carotid magnetic resonance imaging, and cardiovascular outcomes

Background

It is unclear whether faster progression of atherosclerosis explains the higher risk of cardiovascular events in CKD. The objectives of this study were to 1. Characterize the associations of CKD with presence and morphology of atherosclerotic plaques on carotid magnetic resonance imaging (MRI) and 2. Examine the associations of baseline CKD and carotid atherosclerotic plaques with subsequent cardiovascular events.

Methods

In a subgroup (N = 465) of Systolic Blood Pressure Intervention Trial.

(SPRINT) participants, we measured carotid plaque presence and morphology at baseline and after 30-months with MRI. We examined the associations of CKD (baseline eGFR < 60 ml/min/1.73m²) with progression of carotid plaques and the SPRINT cardiovascular endpoint.

Results

One hundred and ninety six (42%) participants had CKD. Baseline eGFR in the non-CKD and CKD subgroups were 77 ± 14 and 49 ± 8 ml/min/1.73 m², respectively. Lipid rich necrotic-core plaque was present in 137 (29.5%) participants. In 323 participants with both baseline and follow-up MRI measurements of maximum wall thickness, CKD was not associated with progression of maximum wall thickness (OR 0.62, 95% CI 0.36 to 1.07, p = 0.082). In 96 participants with necrotic core plaque at baseline and with a valid follow-up MRI, CKD was associated with lower odds of progression of necrotic core plaque (OR 0.41, 95% CI 0.17 to 0.95, p = 0.039). There were 28 cardiovascular events over 1764 person-years of follow-up. In separate Cox models, necrotic core plaque (HR 2.59, 95% CI 1.15 to 5.85) but not plaque defined by maximum wall thickness or presence of a plaque component (HR 1.79, 95% CI 0.73 to 4.43) was associated with cardiovascular events. Independent of necrotic core plaque, CKD (HR 3.35, 95% CI 1.40 to 7.99) was associated with cardiovascular events.

Conclusions

Presence of necrotic core in carotid plaque rather than the presence of plaque per se was associated with increased risk of cardiovascular events. We did not find CKD to be associated with faster progression of necrotic core plaques, although both were independently associated with cardiovascular events. Thus, CKD may contribute to cardiovascular disease principally via mechanisms other than atherosclerosis such as arterial media calcification or stiffening.

Trial Registration

NCT01475747, registered on November 21, 2011.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02260-x.

Uremic Toxins, Oxidative Stress, Atherosclerosis in Chronic Kidney Disease, and Kidney Transplantation

Patients with chronic kidney disease (CKD) are at a high risk for cardiovascular disease (CVD), and approximately half of all deaths among patients with CKD are a direct result of CVD. The premature cardiovascular disease extends from mild to moderate CKD stages, and the severity of CVD and the risk of death increase with a decline in kidney function. Successful kidney transplantation significantly decreases the risk of death relative to long-term dialysis treatment; nevertheless, the prevalence of CVD remains high and is responsible for approximately 20-35% of mortality in renal transplant recipients. The prevalence of traditional and nontraditional risk factors for CVD is higher in patients with CKD and transplant recipients compared with the general population; however, it can only partly explain the highly increased cardiovascular burden in CKD patients. Nontraditional risk factors, unique to CKD patients, include proteinuria, disturbed calcium, and phosphate metabolism, anemia, fluid overload, and accumulation of uremic toxins. This accumulation of uremic toxins is associated with systemic alterations including inflammation and oxidative stress which are considered crucial in CKD progression and CKD-related CVD. Kidney transplantation can mitigate the impact of some of these nontraditional factors, but they typically persist to some degree following transplantation. Taking into consideration the scarcity of data on uremic waste products, oxidative stress, and their relation to atherosclerosis in renal transplantation, in the review, we discussed the impact of uremic toxins on vascular dysfunction in CKD patients and kidney transplant recipients. Special attention was paid to the role of native and transplanted kidney function.

GSTM1 Modulates Expression of Endothelial Adhesion Molecules in Uremic Milieu

Deletion polymorphism of glutathione S-transferase M1 (GSTM1), a phase II detoxification and antioxidant enzyme, increases susceptibility to end-stage renal disease (ESRD) as well as the development of cardiovascular diseases (CVD) among ESRD patients and leads to their shorter cardiovascular survival. The mechanisms by which GSTM1 downregulation contributes to oxidative stress and inflammation in endothelial cells in uremic conditions have not been investigated so far. Therefore, the aim of the present study was to elucidate the effects of GSTM1 knockdown on oxidative stress and expression of a panel of inflammatory markers in human umbilical vein endothelial cells (HUVECs) exposed to uremic serum. Additionally, we aimed to discern whether GSTM1-null genotype is associated with serum levels of adhesion molecules in ESRD patients. HUVECs treated with uremic serum exhibited impaired redox balance characterized by enhanced lipid peroxidation and decreased antioxidant enzyme activities, independently of the GSTM1 knockdown. In response to uremic injury, HUVECs exhibited alteration in the expression of a series of inflammatory cytokines including retinol-binding protein 4 (RBP4), regulated on activation, normal T cell expressed and secreted (RANTES), C-reactive protein (CRP), angiogenin, dickkopf-1 (Dkk-1), and platelet factor 4 (PF4). GSTM1 knockdown in HUVECs showed upregulation of monocyte chemoattractant protein-1 (MCP-1), a cytokine involved in the regulation of monocyte migration and adhesion. These cells also have shown upregulated intracellular and vascular cell adhesion molecules (ICAM-1 and VCAM-1). In accordance with these findings, the levels of serum ICAM-1 and VCAM-1 (sICAM-1 and sVCAM-1) were increased in ESRD patients lacking GSTM1, in comparison with patients with the GSTM1-active genotype. Based on these results, it may be concluded that incubation of endothelial cells in uremic serum induces redox imbalance accompanied with altered expression of a series of cytokines involved in arteriosclerosis and atherosclerosis. The association of GSTM1 downregulation with the altered expression of adhesion molecules might be at least partly responsible for the increased susceptibility of ESRD patients to CVD.

A history of uraemic toxicity and of the European Uraemic Toxin Work Group (EUTox)

The uraemic syndrome is a complex clinical picture developing in the advanced stages of chronic kidney disease, resulting in a myriad of complications and a high early mortality. This picture is to a significant extent defined by retention of metabolites and peptides that with a preserved kidney function are excreted or degraded by the kidneys. In as far as those solutes have a negative biological/biochemical impact, they are called uraemic toxins. Here, we describe the historical evolution of the scientific knowledge about uraemic toxins and the role played in this process by the European Uraemic Toxin Work Group (EUTox) during the last two decades. The earliest knowledge about a uraemic toxin goes back to the early 17th century when the existence of what would later be named as urea was recognized. It took about two further centuries to better define the role of urea and its link to kidney failure, and one more century to identify the relevance of post-translational modifications caused by urea such as carbamoylation. The knowledge progressively extended, especially from 1980 on, by the identification of more and more toxins and their adverse biological/biochemical impact. Progress of knowledge was paralleled and impacted by evolution of dialysis strategies. The last two decades, when insights grew exponentially, coincide with the foundation and activity of EUTox. In the final section, we summarize the role and accomplishments of EUTox and the part it is likely to play in future action, which should be organized around focus points like biomarker and potential target identification, intestinal generation, toxicity mechanisms and their correction, kidney and extracorporeal removal, patient-oriented outcomes and toxin characteristics in acute kidney injury and transplantation.