Randomized trial comparing standard versus thermocontrolled haemodialysis using intradialytic cardiac, brain and renal magnetic resonance imaging

BACKGROUND

Ischaemic end-organ damage during haemodialysis (HD) is a significant problem that may be ameliorated by intradialytic cooling. A randomised trial was performed to compare standard HD (SHD; dialysate temperature 37°C) and programmed cooling of the dialysate [thermocontrolled HD (TCHD)] using multiparametric magnetic resonance imaging (MRI) to assess structural, functional and blood flow changes in the heart, brain and kidneys.

METHODS

Prevalent HD patients were randomly allocated to receive either SHD or TCHD for 2 weeks before undergoing serial MRI at four time points: pre-, during (30 min and 180 min) and post-dialysis. MRI measures include cardiac index, myocardial strain, longitudinal relaxation time (T1), myocardial perfusion, internal carotid and basilar artery flow, grey matter perfusion and total kidney volume. Participants then crossed to the other modality to repeat the study protocol.

RESULTS

Eleven participants completed the study. Separation in blood temperature between TCHD (-0.1 ± 0.3°C) and SHD (+0.3 ± 0.2°C; P = .022) was observed, although there was no difference in tympanic temperature changes between arms. There were significant intradialytic reductions in cardiac index, cardiac contractility (left ventricular strain), left carotid and basilar artery blood flow velocities, total kidney volume, longitudinal relaxation time (T1) of the renal cortex and transverse relaxation rate (T2*) of the renal cortex and medulla, but no differences between arms. Pre-dialysis T1 of the myocardium and left ventricular wall mass index were lower after 2 weeks of TCHD compared with SHD [1266 ms (interquartile range 1250-1291) versus 1311 ± 58 ms, P = .02; 66 ± 22 g/m2 versus 72 ± 23 g/m2, P = .004].

CONCLUSIONS

HD adversely affects cardiac function, reduces carotid and basilar artery blood flow and total kidney volume, but mild dialysate cooling using a biofeedback module did not result in differences in intradialytic MRI measures compared with SHD.

The dietary source of trimethylamine N-oxide and clinical outcomes: an unexpected liaison

The profile of gut microbiota can vary according to host genetic and dietary characteristics, and be influenced by disease state and environmental stressors. The uremic dysbiosis results in a loss of biodiversity and overgrowth of microorganisms that may cause elevation of metabolic solutes such as trimethylamine N-oxide (TMAO), inducing pathogenic effects on its host. In patients with chronic kidney disease (CKD), TMAO levels are elevated because of a decreased clearance and an increased production from the uremic gut dysbiosis with a disrupted intestinal barrier and elevated enzymatic hepatic activity. Dietary precursors of TMAO are abundant in animal-derived foods such as red meat, egg yolk and other full-fat dietary products. TMAO is also found naturally in fish and certain types of seafood, with the TMAO content highly variable according to the depth of the sea where the fish is caught, as well as processing and storage. Although evidence points towards TMAO as being an important link to vascular damage and adverse cardiovascular outcomes, the evidence in CKD patients has not been consistent. In this review we discuss the potential dietary sources of TMAO and its actions on the intestinal microbiome as an explanation for the divergent results. We further highlight the potential of a healthy diet as one feasible therapeutic opportunity to prevent gut dysbiosis and reduce uremic toxin levels in patients with CKD.

From electronic health records to clinical management systems: how the digital transformation can support healthcare services

Healthcare systems worldwide are currently undergoing significant transformations in response to increasing costs, a shortage of healthcare professionals and the growing complexity of medical needs among the population. Value-based healthcare reimbursement systems are emerging as an attempt to incentivize patient-centricity and cost containment. From a technological perspective, the transition to digitalized services is intended to support these transformations. A Health Information System (HIS) is a technological solution designed to govern the data flow generated and consumed by healthcare professionals and administrative staff during the delivery of healthcare services. However, the exponential growth of digital capabilities and applied advanced analytics has expanded their traditional functionalities and brought the promise of automating administrative procedures and simple repetitive tasks, while enhancing the efficiency and outcomes of healthcare services by incorporating decision support tools for clinical management. The future of HIS is headed towards modular architectures that can facilitate implementation and adaptation to different environments and systems, as well as the integration of various tools, such as artificial intelligence (AI) models, in a seamless way. As an example, we present the experience and future developments of the European Clinical Database (EuCliD®). EuCliD is a multilingual HIS used by 20 000 nurses and physicians on a daily basis to manage 105 000 patients treated in 1100 clinics in 43 different countries. EuCliD encompasses patients' follow-up, automatic reporting and mobile applications while enabling efficient management of clinical processes. It is also designed to incorporate multiagent systems to automate repetitive tasks, AI modules and advanced dynamic dashboards.

An explorative cross-sectional analysis of mental health shame and help-seeking intentions in different lifestyles

To identify und support particular target groups for mental health prevention, we explore the links between shame and help-seeking intentions concerning mental health in different lifestyles (based on socioeconomic status as well as health-related behaviors). Lifestyles were operationalized by nine confirmatory, homogenous clusters of the sample. These clusters are based on individuals' similarities in sociodemographic aspects and health behavior. Analyses included t tests, Chi-square, ANOVA, regressions investigating in sociodemographic characteristics. Hierarchical linear models examining cross-sectional associations of shame and willingness to seek help for different lifestyles of participants of the Study of Health in Pomerania (SHIP-START-1 and SHIP-START-3, data collected 2002-2006 and 2014-2016; n = 1630). Hierarchical linear models showed small context effects for lifestyle-related associations of shame and willingness to seek help. For younger as well as male participants, lifestyles indicated different associations of shame and help-seeking intentions: Especially the lifestyles with unhealthy behaviors and high as well as low socioeconomic status resulted in higher shame being associated with low help-seeking intentions in case of mental illness. Lifestyle clusters might be a useful tool to identify marginalized groups with unhealthy behaviors, which should be addressed by interventions and prevention programs.

Comparison of four medium cut-off dialyzers

BACKGROUND

Recently, several pharmaceutical companies have developed new medium cut-off (MCO) dialyzers for expanded hemodialysis (HDx). This study aimed to compare the safety and efficacy of four MCO dialyzers, against each other and versus high-flux hemodialysis (HD) and post-dilution hemodiafiltration (HDF).

METHODS

A prospective study was carried out on 23 patients who underwent six dialysis sessions: two sessions with the FX80 Cordiax in HD and HDF, and four HDx sessions with the Phylther 17-SD, Vie-18X, Elisio HX19 and Theranova 400 dialyzers. The reduction ratios (RRs) of urea, creatinine, β2-microglobulin, myoglobin, kappa free immunoglobulin light chain (κFLC), prolactin, α1-microglobulin, α1-acid glycoprotein, lambda (λFLC) and albumin were compared. Dialysate albumin loss was also measured.

RESULTS

The differences in efficacy between the evaluated dialyzers were minimal in small molecules and even up to the size of β2-microglobulin. The main differences were found between myoglobin, κFLC, prolactin, α1-microglobulin and λFLC RRs, in which all four MCO dialyzers, with similar efficacy, were clearly superior to HD and slightly inferior to HDF treatment. Albumin losses in the dialysate with HD dialyzers were <1 g and between 1.5 and 2.5 g in HDx and HDF. The global removal score values were similar in all four HDx treatments, and again significantly higher than those with HD.

CONCLUSIONS

The results of the four MCO dialyzers evaluated in this study showed good efficiency, with no significant performance differences between them while being completely safe in terms of albumin loss. Likewise, the study confirms the superiority of HDx over high-flux HD with an efficacy close to that of post-dilution HDF.

Current clinical practice in adapted automated peritoneal dialysis (aAPD)-A prospective, non-interventional study

Adapted automated peritoneal dialysis (aAPD), comprising a sequence of dwells with different durations and fill volumes, has been shown to enhance both ultrafiltration and solute clearance compared to standard peritoneal dialysis with constant time and volume dwells. The aim of this non-interventional study was to describe the different prescription patterns used in aAPD in clinical practice and to observe outcomes characterizing volume status, dialysis efficiency, and residual renal function over 1 year. Prevalent and incident, adult aAPD patients were recruited during routine clinic visits, and aAPD prescription, volume status, residual renal function and laboratory data were documented at baseline and every quarter thereafter for 1 year. Treatments were prescribed according to the nephrologist's medical judgement in accordance with each center's clinical routine. Of 180 recruited patients, 160 were analyzed. 27 different aAPD prescription patterns were identified. 79 patients (49.4%) received 2 small, short dwells followed by 3 long, large dwells. During follow-up, volume status changed only marginally, with visit mean values ranging between 1.59 (95% confidence interval: 1.19; 1.99) and 1.97 (1.33; 2.61) L. Urine output and creatinine clearance decreased significantly, accompanied by reductions in ultrafiltration and Kt/V. 25 patients (15.6%) received a renal transplant and 15 (9.4%) were changed to hemodialysis. Options for individualization offered by aAPD are actually used in practice for optimized treatment. Changes observed in renal function and dialysis efficiency measures reflect the natural course of chronic kidney disease. No safety events were observed during the study period.

Proteinuria in COVID-19

Upper respiratory and pulmonary diseases are the primary manifestations of coronavirus disease 2019 (COVID-19). However, kidney involvement has also been recognized and extensively described. A large percentage of affected patients present with acute kidney injury (AKI). However, specific phenotypic aspects of AKI or other renal manifestations of COVID-19 remain sparsely characterized. Many reports indicate that proteinuria can be detected in AKI associated with COVID-19 (CoV-AKI) despite CoV-AKI being largely described as a form of acute tubular injury. On the other hand, individuals of African ancestry with the high-risk APOL1 genotype are uniquely at risk of developing collapsing glomerulopathy when they are infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the entity now known as COVID-19-associated nephropathy (COVAN). Patients with COVAN typically present with nephrotic-range proteinuria. The exact incidence of proteinuria in COVID-19 is unclear due to heterogeneity in the frequency with which proteinuria has been assessed in cases of COVID-19, as well as methodological differences in the way proteinuria is measured and/or reported. In this review we discuss the current evidence of proteinuria as a manifestation of COVID-19 and elaborate on potential pathophysiological mechanisms associated with it.

Pathology of COVID-19-associated acute kidney injury

Acute kidney injury (AKI) is common among hospitalized patients with coronavirus disease 2019 (COVID-19), with the occurrence of AKI ranging from 0.5% to 80%. An improved knowledge of the pathology of AKI in COVID-19 is crucial to mitigate and manage AKI and to improve the survival of patients who develop AKI during COVID-19. In this review, we summarize the published cases and case series of various kidney pathologies seen with COVID-19. Both live kidney biopsies and autopsy series suggest acute tubular injury as the most commonly encountered pathology. Collapsing glomerulopathy and thrombotic microangiopathy are other encountered pathologies noted in both live and autopsy tissues. Other rare findings such as anti-neutrophil cytoplasmic antibody vasculitis, anti-glomerular basement membrane disease and podocytopathies have been reported. Although direct viral infection of the kidney is possible, it is certainly not a common or even widespread finding reported at the time of this writing (November 2020).

COVID-19 pandemic era: is it time to promote home dialysis and peritoneal dialysis?

The novel coronavirus, called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was declared a pandemic in March 2020 by the World Health Organization. Older individuals and patients with comorbid conditions such as hypertension, heart disease, diabetes, lung disease, chronic kidney disease (CKD) and immunologic diseases are at higher risk of contracting this severe infection. In particular, patients with advanced CKD constitute a vulnerable population and a challenge in the prevention and control of the disease. Home-based renal replacement therapies offer an opportunity to manage patients remotely, thus reducing the likelihood of infection due to direct human interaction. Patients are seen less frequently, limiting the close interaction between patients and healthcare workers who may contract and spread the disease. However, while home dialysis is a reasonable choice at this time due to the advantage of isolation of patients, measures must be assured to implement the program. Despite its logistical benefits, outpatient haemodialysis also presents certain challenges during times of crises such as the coronavirus disease 2019 (COVID-19) pandemic and potentially future ones.

From heterogeneous healthcare data to disease-specific biomarker networks: A hierarchical Bayesian network approach

In this work, we introduce an entirely data-driven and automated approach to reveal disease-associated biomarker and risk factor networks from heterogeneous and high-dimensional healthcare data. Our workflow is based on Bayesian networks, which are a popular tool for analyzing the interplay of biomarkers. Usually, data require extensive manual preprocessing and dimension reduction to allow for effective learning of Bayesian networks. For heterogeneous data, this preprocessing is hard to automatize and typically requires domain-specific prior knowledge. We here combine Bayesian network learning with hierarchical variable clustering in order to detect groups of similar features and learn interactions between them entirely automated. We present an optimization algorithm for the adaptive refinement of such group Bayesian networks to account for a specific target variable, like a disease. The combination of Bayesian networks, clustering, and refinement yields low-dimensional but disease-specific interaction networks. These networks provide easily interpretable, yet accurate models of biomarker interdependencies. We test our method extensively on simulated data, as well as on data from the Study of Health in Pomerania (SHIP-TREND), and demonstrate its effectiveness using non-alcoholic fatty liver disease and hypertension as examples. We show that the group network models outperform available biomarker scores, while at the same time, they provide an easily interpretable interaction network.

High-dimensional and heterogeneous healthcare data, such as electronic health records or epidemiological study data, contain much information on yet unknown risk factors that are associated with disease development. The identification of these risk factors may help to improve prevention, diagnosis, and therapy. Bayesian networks are powerful statistical models that can decipher these complex relationships. However, high dimensionality and heterogeneity of data, together with missing values and high feature correlation, make it difficult to automatically learn a good model from data. To facilitate the use of network models, we present a novel, fully automated workflow that combines network learning with hierarchical clustering. The algorithm reveals groups of strongly related features and models the interactions among those groups. It results in simpler network models that are easier to analyze. We introduce a method of adaptive refinement of such models to ensure that disease-relevant parts of the network are modeled in great detail. Our approach makes it easy to learn compact, accurate, and easily interpretable biomarker interaction networks. We test our method extensively on simulated data as well as data from the Study of Health in Pomerania (SHIP-Trend) by learning models of hypertension and non-alcoholic fatty liver disease.

Artificial intelligence enabled applications in kidney disease

Artificial intelligence (AI) is considered as the next natural progression of traditional statistical techniques. Advances in analytical methods and infrastructure enable AI to be applied in health care. While AI applications are relatively common in fields like ophthalmology and cardiology, its use is scarcely reported in nephrology. We present the current status of AI in research toward kidney disease and discuss future pathways for AI. The clinical applications of AI in progression to end-stage kidney disease and dialysis can be broadly subdivided into three main topics: (a) predicting events in the future such as mortality and hospitalization; (b) providing treatment and decision aids such as automating drug prescription; and (c) identifying patterns such as phenotypical clusters and arteriovenous fistula aneurysm. At present, the use of prediction models in treating patients with kidney disease is still in its infancy and further evidence is needed to identify its relative value. Policies and regulations need to be addressed before implementing AI solutions at the point of care in clinics. AI is not anticipated to replace the nephrologists' medical decision-making, but instead assist them in providing optimal personalized care for their patients.

Progression of coronary artery calcification in conventional hemodialysis, nocturnal hemodialysis, and kidney transplantation

Introduction

Cardiovascular disease is the leading cause of death in end-stage renal disease (ESRD) and is strongly associated with vascular calcification. An important driver of vascular calcification is high phosphate levels, but these become lower when patients initiate nocturnal hemodialysis or receive a kidney transplant. However, it is unknown whether nocturnal hemodialysis or kidney transplantation mitigate vascular calcification. Therefore, we compared progression of coronary artery calcification (CAC) between patients treated with conventional hemodialysis, nocturnal hemodialysis, and kidney transplant recipients.

Methods

We measured CAC annually up to 3 years in 114 patients with ESRD that were transplantation candidates: 32 that continued conventional hemodialysis, 34 that initiated nocturnal hemodialysis (≥4x 8 hours/week), and 48 that received a kidney transplant. We compared CAC progression between groups as the difference in square root transformed volume scores per year (ΔCAC SQRV) using linear mixed models. Reference category was conventional hemodialysis.

Results

The mean age of the study population was 53 ±13 years, 75 (66%) were male, and median dialysis duration was 28 (IQR 12–56) months. Median CAC score at enrollment was 171 (IQR 10–647), which did not differ significantly between treatment groups (P = 0.83). Compared to conventional hemodialysis, CAC progression was non-significantly different in nocturnal hemodialysis -0.10 (95% CI -0.77 to 0.57) and kidney transplantation -0.33 (95% CI -0.96 to 0.29) in adjusted models.

Conclusions

Nocturnal hemodialysis and kidney transplantation are not associated with significantly less CAC progression compared to conventional hemodialysis during up to 3 years follow-up. Further studies are needed to confirm these findings, to determine which type of calcification is measured with CAC in end-stage renal disease, and whether that reflects cardiovascular risk.

Meaning of empowerment in peritoneal dialysis: focus groups with patients and caregivers

BACKGROUND

While peritoneal dialysis (PD) can offer patients more independence and flexibility compared with in-center hemodialysis, managing the ongoing and technically demanding regimen can impose a burden on patients and caregivers. Patient empowerment can strengthen capacity for self-management and improve treatment outcomes. We aimed to describe patients' and caregivers' perspectives on the meaning and role of patient empowerment in PD.

METHODS

Adult patients receiving PD (n = 81) and their caregivers (n = 45), purposively sampled from nine dialysis units in Australia, Hong Kong and the USA, participated in 14 focus groups. Transcripts were thematically analyzed.

RESULTS

We identified six themes: lacking clarity for self-management (limited understanding of rationale behind necessary restrictions, muddled by conflicting information); PD regimen restricting flexibility and freedom (burden in budgeting time, confined to be close to home); strength with supportive relationships (gaining reassurance with practical assistance, comforted by considerate health professionals, supported by family and friends); defying constraints (reclaiming the day, undeterred by treatment, refusing to be defined by illness); regaining lost vitality (enabling physical functioning, restoring energy for life participation); and personal growth through adjustment (building resilience and enabling positive outlook, accepting the dialysis regimen).

CONCLUSIONS

Understanding the rationale behind lifestyle restrictions, practical assistance and family support in managing PD promoted patient empowerment, whereas being constrained in time and capacity for life participation outside the home undermined it. Education, counseling and strategies to minimize the disruption and burden of PD may enhance satisfaction and outcomes in patients requiring PD.

Epicardial fat, cardiovascular risk factors and calcifications in patients with chronic kidney disease

Background

Epicardial adipose tissue (EAT) exerts cardiopathogenic effects, but the independent association between EAT and cardiovascular (CV) calcification in patients with chronic kidney disease (CKD) remains controversial. We therefore assessed the association between EAT, CV risk factors and CV calcifications.

Methods

257 patients with CKD Stage 3 and/or overt proteinuria underwent quantification of EAT, coronary artery calcification and aortic valve calcification by computed tomography. Framingham and American College of Cardiology and American Heart Association (ACC-AHA) 10-year CV event risk scores were calculated for each patient.

Results

Using multivariable regression analysis, higher EAT was significantly associated with the majority of investigated risk factors {higher age: odds ratio [OR] 1.05/year [95% confidence interval (CI) 1.02-1.08]; male sex: OR 4.03 [95% CI 2.22-7.31]; higher BMI: OR 1.28/kg/m² [95% CI 1.20-1.37]; former smoking: OR 1.84 [95% CI 1.07-3.17]; lower high-density lipoprotein cholesterol: OR 0.98/mg/dL [95% CI 0.96-1.00] and lower estimated glomerular filtration rate: OR 0.98/mL/min/1.73 m² [95% CI 0.97-0.99]; all P < 0.05} and was not associated with diabetes mellitus, hypertensive nephropathy, total cholesterol and albuminuria. EAT was positively associated with higher ACC-AHA and Framingham risk scores. EAT correlated with coronary artery calcification and aortic valve calcification [Spearman ρ = 0.388 (95% CI 0.287-0.532) and r _rb = 0.409 (95% CI 0.310-0.556), respectively], but these correlations were dependent on CV risk factors.

Conclusions

The increase of EAT can be explained by individual CV risk factors and kidney function and correlates with 10-year risk for CV event scores, suggesting that EAT is a modifiable risk factor in patients with CKD. Although EAT correlates with CV calcifications, these relations depend on CV risk factors.

Measurement of Fluid Status Using Bioimpedance Methods in Korean Pediatric Patients on Hemodialysis

Adequate fluid management is an important therapeutic goal of dialysis. Recently, bioelectrical impedance methods have been used to determine body fluid status, but pediatric reports are rare. To determine the accuracy of bioelectrical impedance methods in the assessment of body fluid statusof children undergoing hemodialysis (HD), 12 children on HD were studied. A multi-frequency bioimpedance analysis device (Inbody S10) and bioimpedance spectroscopy device (BCM) were used to evaluate fluid status. Fluid removal during a HD session (assessed as body-weight change, ΔBWt) was compared with the difference in total body water determined by each device (measured fluid difference, ΔMF), which showed strong correlation using either method (Pearson's coefficient, r = 0.772 with Inbody S10 vs. 0.799 with BCM). Bioimpedance measurement indicated fluid overload (FO; ΔHS greater than 7%) in 34.8% with Inbody S10 and 56.5% with BCM, and only about 60% of children with FO by bioimpedance methods showed clinical symptoms such as hypertension and edema. In some patients with larger weight gain Inbody S10-assessed overhydration (OH) was much smaller than BCM-assessed OH, suggesting that BCM is more relevant in estimating fluid accumulation amount than Inbody S10. To our knowledge, this is the first report on the use of body composition monitors to assess fluid status in Korean children receiving HD.

Vitamin D levels in critically ill patients with acute kidney injury: a protocol for a prospective cohort study (VID-AKI)

INTRODUCTION

Acute kidney injury (AKI) affects more than 50% of critically ill patients. The formation of calcitriol, the active vitamin D metabolite, from the main inactive circulating form, 25-hydroxyvitamin D (25(OH)D), occurs primarily in the proximal renal tubules. This results in a theoretical basis for reduction in levels of calcitriol over the course of an AKI. Vitamin D deficiency is highly prevalent in critically ill adults, and has been associated with increased rates of sepsis, longer hospital stays and increased mortality. The primary objective of this study is to perform serial measurements of 25(OH)D and calcitriol (1,25(OH)₂D), as well as parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23) levels, in critically ill adult patients with and without AKI, and to determine whether patients with AKI have significantly lower vitamin D metabolite concentrations. The secondary objectives are to describe dynamic changes in vitamin D metabolites, PTH and FGF23 during critical illness; to compare vitamin D metabolite concentrations in patients with AKI with and without renal replacement therapy; and to investigate whether there is an association between vitamin D status and outcomes.

METHODS AND ANALYSIS

230 general adult intensive care patients will be recruited. The AKI arm will include 115 critically ill patients with AKI Kidney Disease Improving Global Outcome stage II or stage III. The comparison group will include 115 patients who require cardiovascular or respiratory support, but who do not have AKI. Serial measurements of vitamin D metabolites and associated hormones will be taken on prespecified days. Patients will be recruited from two large teaching Trusts in England. Data will be analysed using standard statistical methods.

ETHICS AND DISSEMINATION

Ethical approval was obtained. Upon completion, the study team will submit the study report for publication in a peer-reviewed scientific journal and for conference presentation.

TRIAL REGISTRATION NUMBER

NCT02869919; Pre-results.