Atrial Fibrillation and Chronic Kidney Disease: Aetiology and Management.

Chronic kidney disease (CKD) and atrial fibrillation (AF) are associated with significant cardiovascular morbidity and mortality. Recent studies have highlighted an increased prevalence and incidence of AF in patients with CKD. This article aims to provide a comprehensive review of current management strategies and considerations of treating atrial fibrillation with concomitant CKD. Potential electrophysiological mechanisms between AF and CKD are explored. Current evidence and literature focusing on pharmacological rate and rhythm control along with procedural intervention is reviewed and presented. The management of AF and CKD together is complex, but particularly pertinent when considering the close cyclical relationship in the progression of both diseases.

A ReaxFF Potential for Modeling Organic Matter Degradation with Oxybromine Oxidants.

Oxidation of organic matter with oxybromine oxidants is ushering in a new era of enhanced hydrocarbon recovery. While these potent reagents are being tested in laboratory and field experiments, there is a pressing demand to delineate the molecular processes governing oxidation reactions at geological depth. Here, we parameterize a ReaxFF potential to model the oxidative decompositions of aliphatic and aromatic hydrocarbons in the presence of water-NaBr solutions that contain oxybromine (BrOn)- oxidizers. Our parameterization results in a reliable empirical bond-order potential that accurately calculates bond energies, exhibiting an RMSE of ∼1.18 eV, corresponding to 1.36 % average error. Reproducing bond dissociation and binding energies from Density Functional Theory (DFT), our parameterization proves transferable to aqueous environments. This H/C/O/Na/Br ReaxFF potential accurately reproduces the oxidation pathways of small hydrocarbons with oxybromine oxidizers. This force field captures proton and oxygen transfer, C-C bond tautomerization, and cleavage, leading to ring-opening and chain fragmentation. Molecular dynamic simulations demonstrate the oxidative degradation of aromatic and aliphatic kerogen-like moieties in bulk solutions. We envision that such reactive force fields will be useful to understand better the oxidation reactions of organic matter formed in geological reservoirs for enhanced shale gas recovery and improved carbon dioxide treatments.

Does cooled dialysate still have a role in reducing intradialytic stress? Implications of the MyTEMP trial.

PURPOSE OF REVIEW: There is an excess of cardiovascular morbidity and mortality in the maintenance haemodialysis population. Targeting traditional risk factors (e.g. hypercholesterolaemia) do not improve cardiovascular outcomes. Repeated myocardial stunning during haemodialysis is an important nontraditional risk, resulting in pathological cardiac remodelling and fibrosis. This review explores dialysate cooling as a management strategy to promote haemodynamic stability, reduce myocardial injury, and improve cardiovascular disease outcomes for individuals receiving maintenance haemodialysis. RECENT FINDINGS: Observational data and small interventional studies demonstrate dialysate cooling has the potential to reduce end-organ damage and provide cardioprotection, renal protection and neuroprotection compared with standard care. These data are limited by the small sample sizes, short follow-up times and lack of long-term patient important outcomes. The MyTEMP study, a multicentre pragmatic randomized controlled trial, demonstrated cooled dialysate (0.5°C below body temperature) vs. standard care did not improve cardiovascular outcomes for prevalent haemodialysis patients. SUMMARY: Dialysate cooling has been widely adopted into routine clinical practice; the MyTEMP study challenges the unit-level approach to implementing dialysate cooling. Due to methodological limitations, the absence of other important patient outcome measures, and lack of granularity of patient-level data, dialysate cooling should not be hastily removed from all dialysis care and warrants further research.

Specific-Ion Effects Unveil a Route for Modulating Oxidatively Triggered Acid Systems for Reservoir Applications.

On-demand in situ preparation of industrially relevant organic acids, namely, methanesulfonic acid, triflic acid, and trifluoroacetic acid, is demonstrated in this study. Sodium and potassium bromate were found to selectively oxidize a series of ammonium salts NH4X, where X = OMs, OTf, or OTFAc, with characteristic clock reaction behavior. The redox system undergoes rapid acid formation following an extended induction time at 150 °C and is identified as a potential candidate for high-temperature oil field chemistry applications where on-demand acid placement is required. Although the reaction kinetics for acid formation from NH4X salts where X = Cl, Br, F, or SO42- follows a pKa trend, the rates of formation of the organic acids are much slower and deviate from this trend. Furthermore, we demonstrate that the rate of acid formation can be modulated by the addition of alkali metal salts, with the strongest effect observed from LiBr. Spectroscopic studies implicate the formation of lithium bromate ion pairs that slow or altogether inhibit the oxidation of NH4+. Additionally, the presence of Br- alters the reaction path, eliminating the clock behavior and creating a pathway for Li+ to strongly inhibit the redox reaction. From these studies, a method for slowing ammonium oxidation under reservoir conditions to sufficiently delay acid formation until the precursors are placed in the zone of interest is identified.

Associations between physical activity levels and renal recovery following acute kidney injury stage 3: a feasibility study.

BACKGROUND: Acute kidney injury (AKI) can lead to chronic kidney disease, which results in poor long-term outcomes. There is plausibility that increased levels of physical activity may promote renal recovery post-AKI. This study aimed to investigate associations between physical activity levels and renal recovery following stage 3 AKI, and to assess the feasibility of measuring physical activity levels in this population. METHODS: Forty One hospitalised patients with AKI stage 3 were enrolled. Serum creatinine and estimated glomerular filtration rate (eGFR) were collected at 12 months prior to the development of AKI, during the hospital admission when the episode of AKI stage 3 occurred, and at 1-, 3- and 6-months post discharge. All participants completed the General Practice Activity Questionnaire (GPPAQ) to assess physical activity levels. A pedometer was also worn for 7 days immediately following discharge and at 6-months post discharge to ascertain an average daily step count. Feasibility outcomes including eligibility, recruitment and retention rates, and losses to follow up were also assessed. RESULTS: The average (± SD) baseline eGFR and median (IQR) serum creatinine was 71 ± 20 mL/min/1.73m2 and 85 (49) µmol/L respectively. A threefold increase in creatinine occurred during hospitalisation 436 (265) µmol/L. Greatest renal recovery occurred prior to discharge, with recovery continuing for a further three months. Inactive individuals (low GPPAQ scores) had consistently higher serum creatinine values compared to those who were active: 1 months 122 (111) µmol/L vs 70 (0) µmol/L, 6 months 112 (57) µmol/L vs 68 (0) µmol/L. Individuals with higher step counts also displayed better renal recovery 6-months post discharge (r = -0.600, p = 0.208). CONCLUSIONS: Higher levels of physical activity are associated with improved renal recovery after 6- months following an episode of stage 3 AKI. A future randomised controlled trial is feasible and would be required to confirm these initial findings.

Prevalence and correlates of physical activity across kidney disease stages: an observational multicentre study.

BACKGROUND: People with chronic kidney disease (CKD) report high levels of physical inactivity, a major modifiable risk factor for morbidity and mortality. Understanding the biological, psychosocial and demographic causes of physical activity behaviour is essential for the development and improvement of potential health interventions and promotional initiatives. This study investigated the prevalence of physical inactivity and determined individual correlates of this behaviour in a large sample of patients across the spectrum of kidney disease. METHODS: A total of 5656 people across all stages of CKD (1-2, 3, 4-5, haemodialysis, peritoneal dialysis and renal transplant recipients) were recruited from 17 sites in England from July 2012 to October 2018. Physical activity was evaluated using the General Practice Physical Activity Questionnaire. Self-reported cardiorespiratory fitness, self-efficacy and stage of change were also assessed. Binominal generalized linear mutually adjusted models were conducted to explore the associations between physical activity and correlate variables. This cross-sectional observational multi-centre study was registered retrospectively as ISRCTN87066351 (October 2015). RESULTS: The prevalence of physical activity (6-34%) was low and worsened with disease progression. Being older, female and having a greater number of comorbidities were associated with greater odds of being physically inactive. Higher haemoglobin, cardiorespiratory fitness and self-efficacy levels were associated with increased odds of being active. Neither ethnicity nor smoking history had any effect on physical activity. CONCLUSIONS: Levels of physical inactivity are high across all stages of CKD. The identification of stage-specific correlates of physical activity may help to prioritize factors in target groups of kidney patients and improve the development and improvement of public health interventions.

The STAT3-IL-10-IL-6 Pathway Is a Novel Regulator of Macrophage Efferocytosis and Phenotypic Conversion in Sterile Liver Injury.

The disposal of apoptotic bodies by professional phagocytes is crucial to effective inflammation resolution. Our ability to improve the disposal of apoptotic bodies by professional phagocytes is impaired by a limited understanding of the molecular mechanisms that regulate the engulfment and digestion of the efferocytic cargo. Macrophages are professional phagocytes necessary for liver inflammation, fibrosis, and resolution, switching their phenotype from proinflammatory to restorative. Using sterile liver injury models, we show that the STAT3-IL-10-IL-6 axis is a positive regulator of macrophage efferocytosis, survival, and phenotypic conversion, directly linking debris engulfment to tissue repair.

Bromate Oxidation of Ammonium Salts: In Situ Acid Formation for Reservoir Stimulation.

A redox chemistry approach has been employed to synthesize an assortment of acids in the subterranean environment for the purpose of enhancing productivity from hydrocarbon-bearing rock formations. Experimental studies revealed that bromate selectively oxidizes a series of ammonium salts NH4X where X = F-, Cl-, Br-, SO42-, and CF3CO2- to produce 5-17 wt % HX. Importantly, the in situ method allows strategic placement of the acid in the zone of interest where the fluid is heated, and the reaction is triggered. Ammonium counteranions are shown to influence the kinetics of the bromate-ammonium reaction, and the conditions are tailored to promote oxidation of ammonium at reservoir temperatures. The reaction is observed to be acid-catalyzed, where the formation of bromous acid (HBrO2) is involved in the rate-limiting step. As a result, an induction period that scales with the p Ka of the acid being formed is followed by rapid formation of the reaction products.

Cardiac Remodelling in Patients Undergoing in-Centre Nocturnal Haemodialysis: Results from the MIDNIGHT Study, a Non-Randomized Controlled Trial.

Evidence suggests extended-hours haemodialysis (HD) may improve cardiovascular, medical and quality-of-life outcomes. In-centre nocturnal haemodialysis (INHD) is an established but underutilized method of providing extended-hours treatment. This 6-month, non-randomized controlled trial (ISRCTN16672784) recruited 13 INHD patients and 12 control patients on conventional HD. The effects of treatment on left ventricular (LV) structure, function and myocardial fibrosis were assessed using cardiac magnetic resonance imaging and native T1 mapping. Quality-of-life and clinical measures were also collected. INHD led to significant reductions in LV mass (-14.75 vs. +6.54 g; p = 0.02), global T1 (-30.62 vs. 0.4 ms; p = 0.05) and non-septal native T1 values (-30.93 vs. 8.96 ms; p = 0.02) over time. There were also significant improvements in serum phosphate (-0.39 vs. +0.02 mmol/L; p = 0.03) and reductions in ultrafiltration rates (-2.32 vs. +0.70 mL/h/kg p = 0.05) between INHD and controls. Six-months of INHD was associated with favourable LV remodelling and reduced myocardial fibrosis compared to patients on conventional haemodialysis.

Motivations and barriers to exercise in chronic kidney disease: a qualitative study.

BACKGROUND: Exercise has the potential to modulate a number of complications associated with chronic kidney disease (CKD). However, typically, CKD patients lead very sedentary lifestyles, the reasons for which are not fully known. The aim of this qualitative study was to gain an understanding of the motivators, barriers and beliefs held by CKD patients regarding exercise. METHODS: We conducted 3 focus groups and 22 semi-structured interviews. Data were collected from nephrology outpatient clinics in the United Kingdom. A total of 36 individuals with CKD stages 1-5 not requiring renal replacement therapy, aged 26-83 years participated in this study. This manuscript outlines the findings from patients with CKD stages 3-5. Focus groups and interviews were transcribed verbatim and analysed thematically. RESULTS: Positive attitudes to exercise reflected autonomous motivations including: exercising for health; enjoyment and social interaction. Family support and goal setting were seen as motivators for exercise and the accessibility of local facilities influenced activity levels. Barriers to exercise were poor health, fear of injury or aggravating their condition, a lack of guidance from healthcare professionals and a lack of facilities. CONCLUSIONS: These findings are an important first stage in the development of a CKD-specific exercise behaviour change intervention. Interventions should operate at multiple levels, with a focus on improving patient autonomy and exercise self-efficacy, support networks and the physical environment (e.g. the accessibility of local facilities). In addition, strategies are required to ensure that the healthcare system is actively promoting and routinely supporting exercise for all patients with CKD.

What to do with foundation therapies for heart failure for patients with end-stage kidney disease on haemodialysis.

There is a significant burden of cardiovascular disease morbidity and mortality in the end-stage kidney disease population, driven by traditional and non-traditional risk factors. Despite its prevalence, heart failure is difficult to diagnose in the dialysis population due to overlapping clinical presentations, limitations of investigations, and the impact on the cardiorenal axis. 'Foundation therapies' are the key medications which improve patient outcomes in heart failure with reduced ejection fraction and include beta-blockers, renin-angiotensin-aldosterone system inhibitors and sodium-glucose cotransporter-2 inhibitors. They are underutilised in the dialysis population due to the exclusion of chronic kidney disease patients from major trials and legitimate clinical concerns e.g. hyperkalaemia, intradialytic hypotension and residual kidney function preservation. A coordinated cardiorenal multidisciplinary approach can guide appropriate diagnostic considerations (biomarkers interpretation, imaging, addressing unique complications of kidney disease), optimise dialysis management (prescription length, frequency and ultrafiltration targets) and when at euvolaemia facilitate the stepwise introduction of appropriate foundation therapies.

The paradox of haemodialysis: the lived experience of the clocked treatment of chronic illness.

Studies exploring the relationship between time and chronic illness have generally focused on measurable aspects of time, also known as linear time. Linear time follows a predictable, sequential order of past, present and future; measured using a clock and predicated on normative assumptions. Sociological concepts addressing lifecourse disruption following diagnosis of chronic illness have served to enhance the understanding of lived experience. To understand the nuanced relationship between time and chronic illness, however, requires further exploration. Here, we show how the implicit assumptions of linear time meet in tension with the lived experience of chronic illness. We draw on interviews and photovoice work with people with end-stage kidney disease in receipt of in-centre-daytime haemodialysis to show how the clocked treatment of chronic illness disrupts experiences of time. Drawing on concepts of 'crip' and 'chronic' time we argue that clocked treatment and the lived experience of chronic illness converge at a paradox whereby clocked treatment allows for the continuation of linear time yet limits freedom. We use the concept of 'crip time' to challenge the normative assumptions implicit within linear concepts of time and argue that the understanding of chronic illness and its treatment would benefit from a 'cripped' starting point.

UK survey of patient and caregiver perspectives on the impact of chronic kidney disease-associated anaemia.

OBJECTIVE: Chronic kidney disease (CKD)-associated anaemia has substantial biopsychosocial impacts. This study explores the impact of CKD-associated anaemia and treatment preferences from the patient perspective. DESIGN: Cross-sectional survey. SETTING: Anonymised online survey implemented by Ipsos UK on behalf of the National Kidney Federation and GSK from October 2022 to January 2023. PARTICIPANTS: Data were collected from UK adults living with CKD (self-reported). PRIMARY AND SECONDARY OUTCOME MEASURES: Outcome measures were exploratory and not predefined. The cross-sectional survey was designed to explore the biopsychosocial impact of living with anaemia on individuals with CKD; their unmet needs; the treatment strategies typically implemented and the associated barriers/facilitators to adherence; the healthcare professional-patient relationship with regard to anaemia diagnosis and management. RESULTS: Of 101 participants, 90 (89%) were patients with CKD and 11 (11%) were informal carers. 96 (95%) participants reported symptom(s) relevant to their experience of CKD. 88 (87%) participants reported symptom(s) associated with anaemia and 61 (64%) expressed an impact on daily life including 18 (19%) unable to perform daily activities, 13 (14%) unable to go to work and 9 (9%) reporting poor social life/interactions. 85 (84%) participants reported they have received treatment for anaemia: intravenous iron (n=55, 54%), iron tablets (n=29, 29%), erythropoietin-stimulating agents (ESAs) via an autoinjector (n=28, 28%), ESA injections via a syringe (n=24, 24%), ESA injections via a dialysis machine (n=17, 17%), folic acid (n=22, 22%) and blood transfusion (n=17, 17%). Six of seven (86%) participants who received their ESA from a healthcare professional at home preferred injections whereas 13/27 (48%) participants who injected themselves at home preferred oral tablets. CONCLUSIONS: There is not a 'one-size-fits-all' approach to the management of CKD-associated anaemia. A personalised approach incorporating the treatment preferences of the individual should be explored when discussing treatment options.

Impact of physical activity on surrogate markers of cardiovascular disease in the haemodialysis population.

Background: The haemodialysis (HD) population is sedentary, with substantial cardiovascular disease risk. In the general population, small increases in daily step count associate with significant reductions in cardiovascular mortality. This study explores the relationship between daily step count and surrogate markers of cardiovascular disease, including left ventricular ejection fraction (LVEF) and native T1 (a marker of diffuse myocardial fibrosis), within the HD population. Methods: This was a post hoc analysis of the association between daily step count and metabolic equivalent of task (MET) and prognostically important cardiac magnetic resonance imaging parameters from the CYCLE-HD study (ISRCTN11299707). Unadjusted linear regression and multiple linear regression adjusted for age, body mass index, dialysis vintage, haemoglobin, hypertension and ultrafiltration volume were performed. Significant relationships were explored with natural cubic spline models with four degrees of freedom (five knots). Results: A total of 107 participants were included [age 56.3 ± 14.1 years, 79 (73.8%) males]. The median daily step count was 2558 (interquartile range 1054-4352). There were significant associations between steps and LVEF (ß = 0.292; P = .009) and steps and native T1 (ß = -0.245; P = .035). Further modelling demonstrated most of the increase in LVEF occurred at up to 2000 steps/day and there was an inverse dose-response relationship between steps and native T1, with the most pronounced reduction in native T1 between ≈2500 and 6000 steps/day. Conclusions: The results suggest an association between daily step count and parameters of cardiovascular health in the HD population. These findings support the recommendations for encouraging physical activity but are not the justification. Further research should evaluate whether a simple physical activity intervention improves cardiovascular outcomes in individuals receiving maintenance HD.

Progressing the understanding of chronic illness and its treatment: A post-human, ethological understanding of haemodialysis.

Haemodialysis is a common treatment option offered internationally for people requiring kidney replacement therapy. Research exploring haemodialysis is predominantly clinical and quantitative, and improvements to its provision and receipt tends also to be clinically focused. In recent years, however, a number of studies have sought to explore the lived experience of haemodialysis. These studies tend to use semi-structured interviews and present descriptive findings. Such findings serve to raise the profile of patient perspectives and encourage thinking beyond the clinical gaze. To progress this, we apply a post-humanism approach to the understanding of the receipt of haemodialysis. Drawing on findings from a study to explore the experience and impact of in-centre, daytime, haemodialysis we follow Fox and Alldred's ethological toolkit to provide a post-human analysis of haemodialysis. In doing so we argue that haemodialysis exists as a heterogenous and changeable assemblage of multiple and fluid, human and non-human factors that has the capacity to affect. Here we outline this post-human approach and the impact it has for understanding not just haemodialysis but also the receipt of treatment for other chronic illnesses.

Biographical dialectics: The ongoing and creative problem solving required to negotiate the biographical disruption of chronic illness.

Here we propose the term 'biographical dialectics' as a sister term to 'biographical disruption' to capture the ongoing problem solving that characterises the lives of many people living with life limiting chronic illnesses. The paper is based on the experiences of 35 adults with end-stage kidney disease (ESKD) in receipt of haemodialysis. Photovoice and semi-structured interviews showed that ESKD and the use of haemodialysis was widely agreed to be biographically disruptive. In talking about and showing disruption through photographs the participants' ongoing problem solving was universal across their diverse experiences. 'Biographical disruption' and Hegalian dialectical logic, are drawn on to make sense of these actions and to further understand the personal and disruptive experience of chronic illness. Based on this, 'biographical dialectics' captures the work that is required to account for and manage the enduring and biographical impact of chronic illness that follows the initial disruption of diagnosis and continues as life progresses.

Reducing the carbon footprint of research: experience from the NightLife study.

BACKGROUND: As set out in the Climate Change Act (2008), the UK National Health Service (NHS) has made a commitment to halve greenhouse gas emissions by 2025 and reach net zero by 2050. Research forms a core part of NHS activity and reducing the carbon footprint of clinical trials is a core element of the National Institute for Health and Care Research Carbon Reduction Strategy (2019). KEY ARGUMENTS: However, support from funding organisations on how to achieve these targets is lacking. This brief communication article reports the reduction in the carbon footprint of the NightLife study, an ongoing multicentre randomised controlled trial assessing the impact of in-centre nocturnal haemodialysis on quality of life. CONCLUSION: By using remote conferencing software and innovative data collection methods, we demonstrated a total saving of 136 tonnes of carbon dioxide equivalent over three workstreams during the first 18 months of the study, following grant activation on 1 January 2020. In addition to the environmental impact, there were additional benefits seen to cost as well as increased participant diversity and inclusion. This work highlights ways in which trials could be made less carbon intensive, more environmentally sustainable and better value for money.