The impact of dialysate flow rate on haemodialysis adequacy: a systematic review and meta-analysis.

Background: Patients with kidney failure treated with maintenance haemodialysis (HD) require appropriate small molecule clearance. Historically, a component of measuring 'dialysis adequacy' has been quantified using urea kinetic modelling that is dependent on the HD prescription. However, the impact of dialysate flow rate on urea clearance remains poorly described in vivo and its influence on other patient-important outcomes of adequacy is uncertain. Methods: We searched Embase, MEDLINE and the Cochrane Library from inception until April 2022 for randomized controlled trials and observational trials comparing a higher dialysate flow rate (800 ml/min) and lower dialysate flow rate (300 ml/min) with a standard dialysis flow rate (500 ml/min) in adults (age ≥18 years) treated with maintenance HD (>90 consecutive days). We conducted a random effects meta-analysis to estimate the pooled mean difference in dialysis adequacy as measured by Kt/V or urea reduction ratio (URR). Results: A total of 3118 studies were identified. Of those, nine met eligibility criteria and four were included in the meta-analysis. A higher dialysate flow rate (800 ml/min) increased single-pool Kt/V by 0.08 [95% confidence interval (CI) 0.05-0.10, P < .00001] and URR by 3.38 (95% CI 1.97-4.78, P < .00001) compared with a dialysate flow rate of 500 ml/min. Clinically relevant outcomes including symptoms, cognition, physical function and mortality were lacking and studies were generally at a moderate risk of bias due to issues with randomization sequence generation, allocation concealment and blinding. Conclusion: A higher dialysate flow increased urea-based markers of dialysis adequacy. Additional high-quality research is needed to determine the clinical, economic and environmental impacts of higher dialysate flow rates.

Kidney Failure Risk Equation in vascular access planning: a population-based study supporting value in decision making.

Background: The Kidney Failure Risk Equation (KFRE) can play a better role in vascular access (VA) planning in patients with chronic kidney disease (CKD) requiring hemodialysis (HD). We described the VA creation and utilization pattern under existing estimated glomerular filtration rate (eGFR)-based referral, and investigated the utility of KFRE score as an adjunct variable in VA planning. Methods: Patients with CKD aged ≥18 years with eGFR <20 mL/min/1.73 m2 who chose HD as dialysis modality from January 2010 to August 2020 were included from a population-based database in British Columbia, Canada. Modality selection date was the index date. Exposures were categorized as (i) current eGFR-based referral, (ii) eGFR-based referral plus KRFE 2-year risk score on index date (KFRE-2) >40% and (iii) eGFR-based referral plus KFRE-2 ≤40%. We estimated the proportion of patients who started HD on arteriovenous fistula/graft (AVF/G) within 2 years, indicating timely pre-emptive creation, and the proportion of patients in whom AVF/G was created but did not start HD within 2 years, indicating too-early creation. Results: Study included 2581 patients, median age 71 years, 60% male. Overall, 1562(61%) started HD and 276 (11%) experienced death before HD initiation within 2 years. Compared with current referral, the proportion of patients who started HD on AVF/G was significantly higher when KFRE-2 was considered in addition to current referral (49% vs 58%, P-value <.001). Adjunct KFRE-2 significantly reduced too-early creation (31% vs 18%, P-value <.001). Conclusions: KFRE in addition to existing eGFR-based referral for VA creation has the potential to improve VA resource utilization by ensuring more patients start HD on AVF/G and may minimize too-early/unnecessary creation. Prospective research is necessary to validate these findings.

Dapagliflozin Utilization in Chronic Kidney Disease and Its Real-World Effectiveness Among Patients with Lower Levels of Albuminuria in the USA and Japan.

INTRODUCTION: Sodium-glucose cotransporter 2 inhibitors such as dapagliflozin have been proven effective for slowing chronic kidney disease (CKD) progression in large outcomes trials that mainly included patients with higher levels of albuminuria. Understanding the real-world utilization and effectiveness of these drugs among patients with CKD with lower levels of albuminuria can inform clinical decision-making in this population. METHODS: Claims data from the USA and Japan were used to describe patients with CKD and urinary albumin-to-creatinine ratio (UACR) < 200 mg/g who were eligible for dapagliflozin 10 mg treatment (initiators and untreated) following its approval for CKD. A quantile regression analysis was performed to evaluate the effect of dapagliflozin 10 mg initiation versus no initiation on estimated glomerular filtration rate (eGFR) slope in a propensity score-matched cohort, using a prevalent new-user design. RESULTS: Dapagliflozin initiators (n = 20,407) mostly had stage 3-4 CKD (69-81% across databases). The most common comorbidities were type 2 diabetes, hypertension and cardiovascular disease. At baseline, a renin-angiotensin system inhibitor was prescribed in 53-81% of patients. Eligible but untreated patients were older and had a higher eGFR and lower comorbidity burden than initiators. Following dapagliflozin initiation, the differences in median eGFR slope between initiators and matched non-initiators were 1.07 mL/min/1.73 m2/year (95% confidence interval [CI] 0.40-1.74) in all patients with UACR < 200 mg/g and 1.28 mL/min/1.73 m2/year (95% CI - 1.56 to 4.12) in patients with UACR < 200 mg/g without type 2 diabetes. CONCLUSIONS: Dapagliflozin 10 mg was prescribed to a broad range of patients with CKD. In patients with UACR < 200 mg/g, dapagliflozin initiation was associated with a clinically meaningful attenuation of eGFR slope compared with non-initiation. These findings supplement available clinical efficacy evidence and suggest that dapagliflozin effectiveness may extend to patients with CKD and UACR < 200 mg/g. Graphical Abstract and Video Abstract available for this article. (Video Abstract 245964 kb).

A Canadian Commentary on the NKF-ASN Task Force Recommendations on Reassessing the Inclusion of Race in Diagnosing Kidney Disease.

In 2021, a committee was commissioned by the Canadian Society of Nephrology to comment on the 2021 National Kidney Foundation-American Society of Nephrology Task Force recommendations on the use of race in glomerular filtration rate estimating equations. The committee met on numerous occasions and agreed on several recommendations. However, the committee did not achieve unanimity, with a minority group disagreeing with the scope of the commentary. As a result, this report presents the viewpoint of the majority members. We endorsed many of the recommendations from the National Kidney Foundation-American Society of Nephrology Task Force, most importantly that race should be removed from the estimated glomerular filtration rate creatinine-based equation. We recommend an immediate implementation of the new Chronic Kidney Disease Epidemiology Collaboration equation (2021), which does not discriminate among any group while maintaining precision. Additionally, we recommend that Canadian laboratories and provincial kidney organizations advocate for increased testing and access to cystatin C because the combination of cystatin C and creatinine in revised equations leads to more precise estimates. Finally, we recommend that future research studies evaluating the implementation of the new equations and changes to screening, diagnosis, and management across provincial health programs be prioritized in Canada.

Association of body mass index with the development of metabolic acidosis in patients with chronic kidney disease.

Aims: Higher body mass index (BMI) is associated with higher bone mass and bone serves as a buffer during the development of metabolic acidosis. The authors sought to examine the relationship between BMI and metabolic acidosis in patients with chronic kidney disease (CKD). Materials and Methods: The study utilized a large US longitudinal data repository including over 103 million patients from healthcare provider organizations to evaluate the relationship between the exposure variable (BMI) and the prevalence and incidence of metabolic acidosis among patients with estimated glomerular filtration rate <60 ml/min/1.73 m2. Incident metabolic acidosis was identified at the first of two consecutive post-index serum bicarbonate values, 10-365 days apart, between 12 and <22 mEq/L in patients with normal index serum bicarbonate. Cox proportional hazard models were adjusted for multiple variables including demographics, comorbidities, income, education, and kidney function. Results: 103,766 patients qualified for this study; 6472 (6.2%) had metabolic acidosis at index. An inverse association between BMI category and metabolic acidosis was observed for both baseline (prevalence) and new-onset (incidence) metabolic acidosis. Compared to BMI category of 18.5 to <25 kg/m2, each category of incrementally higher BMI was associated with a decreasing risk of incident metabolic acidosis; the adjusted hazard ratios (95% confidence interval) were 0.866 (0.824-0.911), 0.770 (0.729-0.813), 0.664 (0.622-0.709), and 0.612 (0.571-0.655) for BMI 25 to <30, 30 to <35, 35 to <40, and 40+ kg/m2, respectively. Conclusions: Among patients with CKD, an incremental increase in BMI was inversely associated with both the prevalence and incidence of metabolic acidosis. These associations suggest that increased body weight may protect against the development of metabolic acidosis, a risk factor for progressive loss of kidney function.

Impaired Renal Function and Major Cardiovascular Events in Young Adults.

BACKGROUND: Cardiovascular (CV) disease in young adults (aged 18-39 years) is on the rise. Whether subclinical reductions in kidney function (ie, estimated glomerular filtration rate [eGFR] above the current threshold for chronic kidney disease but below age-expected values) are associated with elevated CV risk is unknown. OBJECTIVES: The goal of this study was to examine age-specific associations of subclinical eGFR reductions in young adults with major adverse cardiovascular events (MACEs) and MACE plus heart failure (MACE+). METHODS: A retrospective cohort study of 8.7 million individuals (3.6 million aged 18-39 years) was constructed using linked provincial health care data sets from Ontario, Canada (January 2008-March 2021). Cox models were used to examine the association of categorized eGFR (50-120 mL/min/1.73 m2) with MACE (first of CV mortality, acute coronary syndrome, and ischemic stroke) and MACE+, stratified according to age (18-39, 40-49, and 50-65 years). RESULTS: In the study cohort (mean age 41.3 years; mean eGFR 104.2 mL/min/1.73 m2; median follow-up 9.2 years), a stepwise increase in the relative risk of MACE and MACE+ was observed as early as eGFR <80 mL/min/1.73 m2 in young adults (eg, for MACE, at eGFR 70-79 mL/min/1.73 m2, ages 18-30 years: 2.37 events per 1,000 person years [HR: 1.31; 95% CI: 1.27-1.40]; ages 40-49 years: 6.26 events per 1,000 person years [HR: 1.09; 95% CI: 1.06-1.12]; ages 50-65 years: 14.9 events per 1,000 person years [HR: 1.07; 95% CI: 1.05-1.08]). Results persisted for each MACE component and in additional analyses (stratifying according to past CV disease, accounting for albuminuria at index, and using repeated eGFR measures). CONCLUSIONS: In young adults, eGFR below age-expected values were associated with an elevated risk for MACE and MACE+, warranting age-appropriate risk stratification, proactive monitoring, and timely intervention.

A prospective evaluation of patient perspectives and financial considerations during prostate cancer treatment decision-making.

INTRODUCTION: In universal healthcare systems, patients may still encounter financial obstacles from cancer treatments, potentially influencing treatment decision-making. We investigated the relationship between socioeconomic status and treatment decision-making as it pertains to patient values, preferences, and perceived barriers to care for localized prostate cancer. METHODS: We conducted a prospective study of patients undergoing a prostate biopsy for the initial detection of prostate cancer. Sociodemographic variables were collected, with validated instruments used to determine health literacy levels. Patients were divided into two groups using self-reported income; those with a positive identification of prostate cancer underwent additional surveys to ascertain their knowledge of their diagnosis, treatment-related preferences, and socioeconomic barriers to care. Descriptive statistics were used. RESULTS: Of 160 patients, approximately one-third were classified as having low health literacy. Within the low-income group, education levels were lower (34.6% had less than high school education vs. 10.2% in the high-income group) and unemployment rates higher (75.0% unemployed vs. 38.9% in the high-income group). Low-income patients with prostate cancer placed greater importance on indirect out-of-pocket expenses related to treatment (78.3% vs. 33.3%, p=0.001), higher emphasis on treatment-related travel time (50% vs. 15.1%, p=0.004), and more often had difficulty paying for healthcare services in the past (30.9% vs. 9.1%, p=0.02). CONCLUSIONS: Patients with lower household incomes have unique treatment values and decision-making preferences. They may experience additional challenges and barriers to obtaining cancer care, at least partly related to indirect costs. These findings should be considered when framing prostate cancer treatment discussions and designing patient-facing health information.

Safety and Effectiveness of Rivaroxaban Versus Warfarin Across GFR Levels in Atrial Fibrillation: A Population-Based Study in Australia and Canada.

Rationale & Objective: The benefit-risk profile of rivaroxaban versus warfarin for atrial fibrillation (AF) in patients with chronic kidney disease is uncertain. We compared rivaroxaban with warfarin across the range of kidney function in adults with AF. Study Design: Multicenter retrospective cohort. Setting & Participants: Adults with AF and a measure of estimated glomerular filtration rate (eGFR); using administrative data from 5 jurisdictions across Australia and Canada (2011-2018). Kidney function was categorized as eGFR ≥60, 45-59, 30-44, and <30 mL/min/1.73 m2. Patients receiving dialysis and kidney transplant recipients were excluded. Exposures: New dispensation of either rivaroxaban or warfarin. Outcomes: Composite (1) effectiveness outcome (all-cause death, ischemic stroke, or transient ischemic attack) and (2) major bleeding events (intracranial, gastrointestinal, or other) at 1 year. Analytical Approach: Cox proportional hazards models accounting for propensity score matching were performed independently in each jurisdiction and then pooled using random-effects meta-analysis. Results: 55,568 patients (27,784 rivaroxaban-warfarin user matched pairs; mean age 74 years, 46% female, 33.5% with eGFR <60 mL/min/1.73 m2) experienced a total of 4,733 (8.5%) effectiveness and 1,144 (2.0%) bleeding events. Compared to warfarin, rivaroxaban was associated with greater or similar effectiveness across a broad range of kidney function (pooled HRs of 0.72 [95% CI, 0.66-0.78], 0.78 [95% CI, 0.58-1.06], 0.70 [95% CI, 0.57-0.87], and 0.78 [95% CI, 0.62-0.99]) for eGFR ≥60, 45-59, 30-44, and <30 mL/min/1.73 m2, respectively). Rivaroxaban was also associated with similar risk of major bleeding across all eGFR categories (pooled HRs of 0.75 [95% CI, 0.56-1.00], 1.01 [95% CI, 0.79-1.30], 0.87 [95% CI, 0.66-1.15], and 0.63 [95% CI, 0.37-1.09], respectively). Limitations: Unmeasured treatment selection bias and residual confounding. Conclusions: In adults with AF, rivaroxaban compared with warfarin was associated with lower or similar risk of all-cause death, ischemic stroke and transient ischemic attack and similar risk of bleeding across a broad range of kidney function. Plain-Language Summary: This real-world study involved a large cohort of 55,568 adults with atrial fibrillation from 5 jurisdictions across Australia and Canada. It showed that the favorable safety (bleeding) and effectiveness (stroke or death) profile of rivaroxaban compared with warfarin was consistent across different levels of kidney function. This study adds important safety data on the use of rivaroxaban in patients with reduced kidney function, including those with estimated glomerular filtration rate <30 mL/min/1.73 m2 in whom the risks and benefits of rivaroxaban use is most uncertain. Overall, the study supports the use of rivaroxaban as a safe and effective alternative to warfarin for atrial fibrillation across differing levels of kidney function.

A Predictive Model for Kidney Failure After Nephrectomy for Localized Kidney Cancer: The Kidney Cancer Risk Equation.

RATIONALE & OBJECTIVE: Nephrectomy is the mainstay of treatment for individuals with localized kidney cancer. However, surgery can potentially result in the loss of kidney function or in kidney failure requiring dialysis/kidney transplantation. There are currently no clinical tools available to preoperatively identify which patients are at risk of kidney failure over the long term. Our study developed and validated a prediction equation for kidney failure after nephrectomy for localized kidney cancer. STUDY DESIGN: Population-level cohort study. SETTING & PARTICIPANTS: Adults (n=1,026) from Manitoba, Canada, with non-metastatic kidney cancer diagnosed between January 1, 2004, and December 31, 2016, who were treated with either a partial or radical nephrectomy and had at least 1 estimated glomerular filtration rate (eGFR) measurement before and after nephrectomy. A validation cohort included individuals in Ontario (n=12,043) with a diagnosis of localized kidney cancer between October 1, 2008, and September 30, 2018, who received a partial or radical nephrectomy and had at least 1 eGFR measurement before and after surgery. NEW PREDICTORS & ESTABLISHED PREDICTORS: Age, sex, eGFR, urinary albumin-creatinine ratio, history of diabetes mellitus, and nephrectomy type (partial/radical). OUTCOME: The primary outcome was a composite of dialysis, transplantation, or an eGFR<15mL/min/1.73m2 during the follow-up period. ANALYTICAL APPROACH: Cox proportional hazards regression models evaluated for accuracy using area under the receiver operating characteristic curve (AUC), Brier scores, calibration plots, and continuous net reclassification improvement. We also implemented decision curve analysis. Models developed in the Manitoba cohort were validated in the Ontario cohort. RESULTS: In the development cohort, 10.3% reached kidney failure after nephrectomy. The final model resulted in a 5-year area under the curve of 0.85 (95% CI, 0.78-0.92) in the development cohort and 0.86 (95% CI, 0.84-0.88) in the validation cohort. LIMITATIONS: Further external validation needed in diverse cohorts. CONCLUSIONS: Our externally validated model can be easily applied in clinical practice to inform preoperative discussions about kidney failure risk in patients facing surgical options for localized kidney cancer. PLAIN-LANGUAGE SUMMARY: Patients with localized kidney cancer often experience a lot of worry about whether their kidney function will remain stable or will decline if they choose to undergo surgery for treatment. To help patients make an informed treatment decision, we developed a simple equation that incorporates 6 easily accessible pieces of patient information to predict the risk of reaching kidney failure 5 years after kidney cancer surgery. We expect that this tool has the potential to inform patient-centered discussions tailored around individualized risk, helping ensure that patients receive the most appropriate risk-based care.

Practical Utilization of Prediction Equations in Chronic Kidney Disease.

Chronic kidney disease (CKD) is common and can lead to kidney failure, cardiovascular complications, and early mortality. While nephrologists can provide valuable insights for patients at all stages of CKD, these scarce resources should be targeted at patients with the highest risk of progression and adverse outcomes. Prediction models are tools that can help providers risk stratify patients if they are effectively implemented into the clinical workflow. We believe these equations should demonstrate (1) clinical utility: where they can provide useful information to the physician and patients; and (2) clinical usability: where they are able to be easily integrated into clinical workflow and do not result in unnecessary costs or visits. CKD often remains unrecognized until later stages when a large window of opportunity to delay progression has already passed. Models to determine progression of CKD using thresholds such as a 40% decline in eGFR can provide clinical utility in risk stratifying patients at all stages of CKD, an endpoint that has been recommended by the FDA for the evaluation of drug approvals for disease-modifying therapies. For patients at more advanced stages of CKD with a greater risk of kidney failure, tools such as the kidney failure risk equation can be implemented to help guide most costly decisions, such as referral to multidisciplinary care, commencing dialysis modality education, or planning for vascular access placement surgery. In addition, models focused on determining outcomes following dialysis initiation can help inform shared decision-making between patient and provider to better inform decisions around conservative care. To ensure widespread adoption of these tools, it is important to ensure that they are broadly generalizable to many health settings and easily implemented into existing clinic workflows with minimum disruption.

The Development of a Comprehensive Clinicopathologic Registry for Glomerular Diseases Using Natural Language Processing.

Background: Glomerulonephritis (GN) represents a common cause of chronic kidney disease, and treatment to slow or prevent progression of GN is associated with significant morbidity. Large patient registries have improved the understanding of risk stratification, treatment selection, and definitions of treatment response in GN, but can be resource-intensive, with incomplete patient capture. Objective: To describe the creation of a comprehensive clinicopathologic registry for all patients undergoing kidney biopsy in Manitoba, using natural language processing software for data extraction from pathology reports, as well as to describe cohort characteristics and outcomes. Design: Retrospective population-based cohort study. Setting: Tertiary care center in the province of Manitoba. Patients: All patients undergoing a kidney biopsy in the province of Manitoba from 2002 to 2019. Measurements: Descriptive statistics are presented for the most common glomerular diseases, along with outcomes of kidney failure and mortality for the individual diseases. Methods: Data from native kidney biopsy reports from January 2002 to December 2019 were extracted into a structured database using a natural language processing algorithm employing regular expressions. The pathology database was then linked with population-level clinical, laboratory, and medication data, creating a comprehensive clinicopathologic registry. Kaplan-Meier curves and Cox models were constructed to assess the relationship between type of GN and outcomes of kidney failure and mortality. Results: Of 2421 available biopsies, 2103 individuals were linked to administrative data, of which 1292 had a common glomerular disease. The incidence of yearly biopsies increased almost 3-fold over the study period. Among common glomerular diseases, immunoglobulin A (IgA) nephropathy was the most common (28.6%), whereas infection-related GN had the highest proportions of kidney failure (70.3%) and all-cause mortality (42.3%). Predictors of kidney failure included urine albumin-to-creatinine ratio at the time of biopsy (adjusted hazard ratio [HR] = 1.43, 95% confidence interval [CI] = 1.24-1.65), whereas predictors of mortality included age at the time of biopsy (adjusted HR = 1.05, 95% CI = 1.04-1.06) and infection-related GN (adjusted HR = 1.85, 95% CI = 1.14-2.99, compared with the reference category of IgA nephropathy). Limitations: Retrospective, single-center study with a relatively small number of biopsies. Conclusions: Creation of a comprehensive glomerular diseases registry is feasible and can be facilitated through the use of novel data extraction methods. This registry will facilitate further epidemiological research in GN.

Contexte: La glomérulonéphrite (GN) est une cause courante d'insuffisance rénale chronique. Le traitement pour ralentir ou prévenir la progression de la GN est associé à une morbidité significative. Les vastes registres de patients ont permis de mieux comprendre la stratification des risques, la sélection du traitement et les définitions de la réponse au traitement en contexte de GN, mais ces registres exigent beaucoup de ressources et la saisie des données du patient peut être incomplète. Objectifs: Décrire, à l'aide d'un logiciel de traitement en langage naturel pour l'extraction des données des rapports pathologiques, la création d'un registre clinicopathologique complet pour tous les patients subissant une biopsie rénale au Manitoba, et décrire les caractéristiques et les résultats de la cohorte. Conception: Étude de cohorte rétrospective basée sur la population. Cadre: Centre de soins tertiaires de la province du Manitoba. Sujets: Tous les patients ayant subi une biopsie rénale entre 2002 et 2019 au Manitoba. Mesures: Des statistiques descriptives sont présentées pour les maladies glomérulaires les plus courantes, accompagnées des résultats d'insuffisance rénale et de mortalité pour les maladies individuelles. Méthodologie: Les données des rapports de biopsie sur un rein natif entre janvier 2002 et décembre 2019 ont été extraites d'une base de données structurée à l'aide d'un algorithme de traitement en langage naturel utilisant des expressions régulières. La base de données des pathologies a ensuite été reliée aux données cliniques, de laboratoire et de médicaments au niveau de la population, pour créer un registre clinicopathologique complet. Des courbes Kaplan-Meier et des modèles de Cox ont été construits pour évaluer la relation entre le type de GN et les résultats d'insuffisance rénale et de mortalité. Résultats: Des 2 421 biopsies réalisées, 2 103 concernaient des individus liés à des données administratives; de ceux-ci, 1 292 étaient atteints d'une maladie glomérulaire courante. L'incidence des biopsies annuelles a presque été multipliée par trois au cours de la période étudiée. Parmi les maladies glomérulaires courantes, la néphropathie à IgA était la plus fréquente (28,6 %). Les GN liées à une infection présentaient les proportions les plus élevées d'insuffisance rénale (70,3 %) et de mortalité toutes causes confondues (42,3 %). Les facteurs prédictifs de l'insuffisance rénale comprenaient le rapport albumine/créatinine urinaire au moment de la biopsie (rapport de risque corrigé [RRc]: 1,43; intervalle de confiance à 95 % [IC 95 %]: 1,24-1,65), alors que les facteurs prédictifs de la mortalité incluaient l'âge au moment de la biopsie (RRc: 1,05; IC 95 %: 1,04-1,06) et les GN liées à une infection (RRc: 1,85; IC 95 %: 1,14-2,99; par rapport à la catégorie de référence de la néphropathie à IgA). Limites: Étude rétrospective menée dans un seul centre sur un nombre relativement faible de biopsies. Conclusion: La création d'un registre complet des maladies glomérulaires est réalisable et peut être facilitée par l'utilisation de nouvelles méthodes d'extraction des données. Ce registre facilitera de futures recherches épidémiologiques sur la GN. Enregistrement de l'essai: ne s'applique pas, cette étude n'est pas un essai clinique.

Patient Management and Clinical Outcomes Associated with a Recorded Diagnosis of Stage 3 Chronic Kidney Disease: The REVEAL-CKD Study.

INTRODUCTION: Guidelines for the treatment of chronic kidney disease (CKD) recommend early intervention and management to slow disease progression. However, associations between diagnosis and CKD progression are not fully understood. METHODS: REVEAL-CKD (NCT04847531) is a retrospective observational study of patients with stage 3 CKD. Data were extracted from the US TriNetX database. Eligible patients had two consecutive estimated glomerular filtration rate (eGFR) measurements indicative of stage 3 CKD (≥ 30 and < 60 ml/min/1.73 m2) recorded 91-730 days apart from 2015 to 2020. Diagnosed patients were included if their first CKD diagnosis code was recorded at least 6 months after their second qualifying eGFR measurement. We assessed CKD management and monitoring practices for the 180 days before and after CKD diagnosis, annual eGFR decline in the 2 years before and after CKD diagnosis, and associations between diagnostic delay and post-diagnosis event rates. RESULTS: The study included 26,851 patients. After diagnosis, we observed significant increases in the prescribing rate of guideline-recommended medications such as angiotensin-converting enzyme inhibitors (rate ratio [95% confidence interval]: 1.87 [1.82, 1.93]), angiotensin receptor blockers (1.91 [1.85, 1.97]) and mineralocorticoid receptor antagonists (2.23 [2.13, 2.34]). Annual eGFR decline was significantly reduced following a CKD diagnosis, from 3.20 ml/min/1.73 m2 before diagnosis to 0.74 ml/min/1.73 m2 after diagnosis. Delayed diagnosis (by 1-year increments) was associated with elevated risk of CKD progression to stage 4/5 (1.40 [1.31-1.49]), kidney failure (hazard ratio [95% confidence interval]: 1.63 [1.23-2.18]) and the composite of myocardial infarction, stroke and hospitalization for heart failure (1.08 [1.04-1.13]). CONCLUSIONS: A recorded CKD diagnosis was associated with significant improvements in CKD management and monitoring practices and attenuated eGFR decline. Recorded diagnosis of stage 3 CKD is an important first step to reduce the risk of disease progression and minimize adverse clinical outcomes. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT04847531.

Chronic kidney disease (CKD) is a long-term condition in which the function of the kidneys is reduced. Kidney function is monitored using a measurement called the estimated glomerular filtration rate. CKD can be separated into stages of severity, ranging from 1 (mild) to 5 (severe), using estimated glomerular filtration rate. Mild to moderate CKD (stages 1­3) is difficult to diagnose because there are usually no symptoms. In this study from the REVEAL-CKD programme, we looked at the effects of having undiagnosed stage 3 (moderate) CKD and examined how a CKD diagnosis affects disease management and worsening of the condition. Using a database of medical records for patients in the USA called TriNetX, we looked at data from over 26,000 patients with stage 3 CKD who were identified using estimated glomerular filtration rate measurements. We found that healthcare teams prescribed significantly more guideline-recommended medications and did more clinical monitoring in the 180 days after a CKD diagnosis than they did before the diagnosis. Additionally, the rate of decline in kidney function slowed after a CKD diagnosis. Delaying diagnosis by 1 year increased the risk of deterioration of the condition by 40%, the risk of needing a kidney transplant or long-term dialysis treatment by 63% and the risk of major heart and blood vessel diseases (known as cardiovascular events) by 8%. Our findings suggest that diagnosis of stage 3 CKD is an important first step to reduce the risk of the disease worsening and other complications. Video Abstract (MP4 82773 KB).

Ticagrelor as Compared to Clopidogrel Following Percutaneous Coronary Intervention for Acute Coronary Syndrome.

Dual antiplatelet therapy with acetylsalicylic acid and a P2Y12 inhibitor has become a mainstay of therapy after percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). Although higher-potency P2Y12 inhibitors are preferred over clopidogrel in major society guidelines, recent evidence has questioned the extent of the benefit. It is important to evaluate the relative efficacy and safety of P2Y12 inhibitors in a real-world setting. This is a retrospective cohort study of all patients who underwent PCI for ACS in a Canadian province from January 1, 2015 to March 31, 2020. Baseline characteristics, including co-morbidities, medications, and bleeding risk, were obtained. Propensity matching was used to compare patients who received ticagrelor versus clopidogrel. The primary outcome was occurrence of major adverse cardiovascular events (MACEs) at 12 months, defined as death, nonfatal myocardial infarction, or unplanned revascularization. Secondary outcomes included all-cause mortality, major bleeding, stroke, and all-cause hospitalization. A total of 6,665 patients were included; 2,108 received clopidogrel and 4,214 received ticagrelor. Patients who received clopidogrel were older, had more co-morbidities, including cardiovascular risk factors, and had a higher bleeding risk. In 1.925 propensity score-matched pairs, ticagrelor was associated with a significantly lower risk of MACE (hazard ratio 0.79, 0.67 to 0.93, p <0.01) and hospitalization (hazard ratio 0.85, 0.77 to 0.95, p <0.01). No difference was observed in the risk of major bleeding. A statistically nonsignificant trend toward reduced risk of all-cause mortality was noted. In conclusion, in a real-world high-risk cohort, ticagrelor was associated with decreased risk of MACE and all-cause hospitalization compared with clopidogrel after PCI for ACS.

Serum Bicarbonate and Graft and Patient Outcomes Among Kidney Transplant Recipients: A Retrospective Cohort Study Evaluating Changes in Serum Bicarbonate Over Time.

Rationale & Objective: Identification of treatable risk factors for kidney allograft failure is necessary to improve graft longevity. Metabolic acidosis with either low serum bicarbonate or normal serum bicarbonate (eubicarbonatemic metabolic acidosis) is implicated in native kidney disease progression but its effects in kidney transplant recipients are unclear. Study Design: Retrospective cohort study. Setting & Participants: An Integrated Claims-Clinical dataset of US patients with chronic kidney disease (estimated glomerular filtration rates <60 mL/min/1.73 m2) and serum bicarbonate data were used to generate a cohort of kidney transplant recipients with data from ≥1 year before and after transplantation. Primary Predictor: The primary independent variable was a change in serum bicarbonate from baseline. Outcomes: The primary outcomes were graft failure and all-cause mortality. The secondary outcomes were major adverse cardiac events and all-cause hospitalization. Analytical Approach: We used adjusted time-dependent Cox proportional hazards models to assess the risk of graft failure, all-cause mortality, major adverse cardiac events, and time to first hospitalization. Results: In this US community-based cohort of 1,915 kidney transplant recipients with a median follow-up of ∼2.5 years, each 1-mEq/L increase in serum bicarbonate was associated with significantly lower hazard of graft loss, death, major adverse cardiac events, and hospitalization by 10%, 8%, 4%, and 8%, respectively. Limitations: Possible residual confounding. Conclusions: In a US community-based population of kidney transplant recipients, even small incremental increases in serum bicarbonate (1 mEq/L) were significantly associated with reduced hazard of graft loss, all-cause mortality, cardiovascular events, and hospitalization. Interventional trials evaluating the potential benefits of treating metabolic acidosis in kidney transplant recipients are warranted.

A Health Survey-Based Prediction Equation for Incident CKD.

BACKGROUND: Prediction tools that incorporate self-reported health information could increase CKD awareness, identify modifiable lifestyle risk factors, and prevent disease. We developed and validated a survey-based prediction equation to identify individuals at risk for incident CKD (eGFR <60 ml/min per 1.73 m2), with and without a baseline eGFR. METHODS: A cohort of adults with an eGFR ≥70 ml/min per 1.73 m2 from Ontario, Canada, who completed a comprehensive general population health survey between 2000 and 2015 were included (n=22,200). Prediction equations included demographics (age, sex), comorbidities, lifestyle factors, diet, and mood. Models with and without baseline eGFR were derived and externally validated in the UK Biobank (n=15,522). New-onset CKD (eGFR <60 ml/min per 1.73 m2) with ≤8 years of follow-up was the primary outcome. RESULTS: Among Ontario individuals (mean age, 55 years; 58% women; baseline eGFR, 95 (SD 15) ml/min per 1.73 m2), new-onset CKD occurred in 1981 (9%) during a median follow-up time of 4.2 years. The final models included lifestyle factors (smoking, alcohol, physical activity) and comorbid illnesses (diabetes, hypertension, cancer). The model was discriminating in individuals with and without a baseline eGFR measure (5-year c-statistic with baseline eGFR: 83.5, 95% confidence interval [CI], 82.2 to 84.9; without: 81.0, 95% CI, 79.8 to 82.4) and well calibrated. In external validation, the 5-year c-statistic was 78.1 (95% CI, 74.2 to 82.0) and 66.0 (95% CI, 61.6 to 70.4), with and without baseline eGFR, respectively, and maintained calibration. CONCLUSIONS: Self-reported lifestyle and health behavior information from health surveys may aid in predicting incident CKD. PODCAST: This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast.aspx?p=CJASN&e=2023_01_10_CJN05650522.mp3.

Design and population of the VALOR-CKD study: a multicenter, randomized, double-blind, placebo-controlled trial evaluating the efficacy and safety of veverimer in slowing progression of chronic kidney disease in patients with metabolic acidosis.

BACKGROUND: Whether treating metabolic acidosis slows progression of chronic kidney disease (CKD) has not been established. Veverimer is a novel hydrochloric acid binder that removes acid from the gastrointestinal tract leading to an increase in serum bicarbonate; it is being developed to treat metabolic acidosis with the goal of slowing progression of CKD. METHODS: The VALOR-CKD trial is an international, randomized, multicenter, double-blind, placebo-controlled study designed to evaluate the effect of once-daily veverimer on kidney disease progression in patients with metabolic acidosis and CKD. Eligibility criteria include a serum bicarbonate in the range of 12-20 mmol/L and an estimated glomerular filtration rate (eGFR) of 20-40 mL/min/1.73 m2. The primary outcome is kidney disease progression defined as the development of end-stage kidney disease, a sustained decline in eGFR of >40% from baseline or death due to kidney failure. Key secondary endpoints include effects on physical function. RESULTS: Between December 2018 and December 2021, 1480 participants were randomized. The mean age at baseline was 65.1 years and 42% of the patients were female. The mean baseline eGFR was 29.1 mL/min/1.73 m2 and mean serum bicarbonate was 17.5 mmol/L. The median urine albumin-to-creatinine ratio at screening was 201 mg/g and the median 5-year predicted risk of kidney failure was 32%. Diabetes and hypertension were present in 56% and 98% of participants, respectively. CONCLUSIONS: VALOR-CKD has recruited a large population of people with metabolic acidosis at high risk for CKD progression to determine the effects of veverimer on the risk of progressive loss of kidney function.

Kidney function and the comparative effectiveness and safety of direct oral anticoagulants vs. warfarin in adults with atrial fibrillation: a multicenter observational study.

AIMS: The aim of this study was to determine the comparative effectiveness and safety of direct oral anticoagulants (DOACs) and warfarin in adults with atrial fibrillation (AF) by level of kidney function. METHODS AND RESULTS: We pooled findings from five retrospective cohorts (2011-18) across Australia and Canada of adults with; a new dispensation for a DOAC or warfarin, an AF diagnosis, and a measure of baseline estimated glomerular filtration rate (eGFR). The outcomes of interest, within 1 year from the cohort entry date, were: (1) the composite of all-cause death, first hospitalization for ischaemic stroke, or transient ischaemic attack (effectiveness), and (2) first hospitalization for major bleeding defined as an intracranial, upper or lower gastrointestinal, or other bleeding (safety). Cox models were used to examine the association of a DOAC vs. warfarin with outcomes, after 1:1 matching via a propensity score. Kidney function was categorized as eGFR ≥60, 45-59, 30-44, and <30 mL/min/1.73 m2. A total of 74 542 patients were included in the matched analysis. DOAC initiation was associated with greater or similar effectiveness compared with warfarin initiation across all eGFR categories [pooled HRs (95% CIs) for eGFR categories: 0.74(0.69-0.79), 0.76(0.54-1.07), 0.68(0.61-0.75) and 0.86(0.76-0.98)], respectively. DOAC initiation was associated with lower or similar risk of major bleeding than warfarin initiation [pooled HRs (95% CIs): 0.75(0.65-0.86), 0.81(0.65-1.01), 0.82(0.66-1.02), and 0.71(0.52-0.99), respectively). Associations between DOAC initiation, compared with warfarin initiation, and study outcomes were not modified by eGFR category. CONCLUSION: DOAC use, compared with warfarin use, was associated with a lower or similar risk of all-cause death, ischaemic stroke, and transient ischaemic attack and also a lower or similar risk of major bleeding across all levels of kidney function.

Patient views regarding cannabis use in chronic kidney disease and kidney failure: a survey study.

BACKGROUND: Cannabis is frequently used recreationally and medicinally, including for symptom management in patients with kidney disease. METHODS: We elicited the views of Canadian adults with kidney disease regarding their cannabis use. Participants were asked whether they would try cannabis for anxiety, depression, restless legs, itchiness, fatigue, chronic pain, decreased appetite, nausea/vomiting, sleep, cramps and other symptoms. The degree to which respondents considered cannabis for each symptom was assessed with a modified Likert scale ranging from 1 to 5 (1, definitely would not; 5, definitely would). Multilevel multivariable linear regression was used to identify respondent characteristics associated with considering cannabis for symptom control. RESULTS: Of 320 respondents, 290 (90.6%) were from in-person recruitment (27.3% response rate) and 30 (9.4%) responses were from online recruitment. A total of 160/320 respondents (50.2%) had previously used cannabis, including smoking [140 (87.5%)], oils [69 (43.1%)] and edibles [92 (57.5%)]. The most common reasons for previous cannabis use were recreation [84/160 (52.5%)], pain alleviation [63/160 (39.4%)] and sleep enhancement [56/160 (35.0%)]. Only 33.8% of previous cannabis users thought their physicians were aware of their cannabis use. More than 50% of respondents probably would or definitely would try cannabis for symptom control for all 10 symptoms. Characteristics independently associated with interest in trying cannabis for symptom control included symptom type (pain, sleep, restless legs), online respondent {ß = 0.7 [95% confidence interval (CI) 0.1-1.4]} and previous cannabis use [ß = 1.2 (95% CI 0.9-1.5)]. CONCLUSIONS: Many patients with kidney disease use cannabis and there is interest in trying cannabis for symptom control.

Metabolic acidosis is undertreated and underdiagnosed: a retrospective cohort study.

BACKGROUND: Guidelines recommend treatment of metabolic acidosis (MA) in patients with chronic kidney disease (CKD), but the diagnosis and treatment rates in real-world settings are unknown. We investigated the frequency of MA treatment and diagnosis in patients with CKD. METHODS: In this retrospective cohort study, we examined administrative health data from two US databases [Optum's de-identified Integrated Claims + Clinical Electronic Health Record Database (US EMR cohort; 1 January 2007 to 30 June 2019) and Symphony Health Solutions IDV® (US claims cohort; 1 May 2016 to 30 April 2019)] and population-level databases from Manitoba, Canada (1 April 2006 to 31 March 2018). Patients who met laboratory criteria indicative of CKD and chronic MA were included: two consecutive estimated glomerular filtration results <60 mL/min/1.73 m2 and two serum bicarbonate results 12 to <22 mEq/L over 28-365 days. Outcomes included treatment of MA (defined as a prescription for oral sodium bicarbonate) and a diagnosis of MA (defined using administrative records). Outcomes were assessed over a 3-year period (1 year pre-index, 2 years post-index). RESULTS: A total of 96 184 patients were included: US EMR, 6179; Manitoba, 3223; US Claims, 86 782. Sodium bicarbonate treatment was prescribed for 17.6%, 8.7% and 15.3% of patients, and a diagnosis was found for 44.7%, 20.9% and 20.9% of patients, for the US EMR, Manitoba and US Claims cohorts, respectively. CONCLUSIONS: This analysis of 96 184 patients with laboratory-confirmed MA from three independent cohorts of patients with CKD and MA highlights an important diagnosis and treatment gap for this disease-modifying complication.

The Effect of Gender-Affirming Hormone Therapy on Measures of Kidney Function: A Systematic Review and Meta-Analysis.

BACKGROUND AND OBJECTIVES: Gender-affirming hormone therapy modifies body composition and lean muscle mass in transgender persons. We sought to characterize the change in serum creatinine, other kidney function biomarkers, and GFR in transgender persons initiating masculinizing and feminizing gender-affirming hormone therapy. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We searched PubMed, EMBASE, the Cochrane Library, and ClinicalTrials.gov from inception to September 16, 2020 for randomized controlled trials, observational studies, and case series that evaluated the change in serum creatinine, other kidney function biomarkers, and GFR before and after the initiation of gender-affirming hormone therapy in adult transgender persons. Two reviewers independently screened and abstracted data, and disagreements were resolved by a third reviewer. A random effects meta-analysis was performed to determine the change in outcomes over follow-up of 3, 6, and 12 months. RESULTS: Of the 4758 eligible studies, 26 met the inclusion criteria, including nine studies that recruited 488 transgender men and 593 women in which data were meta-analyzed. There was heterogeneity in study design, populations, gender-affirming hormone therapy routes, and dosing. At 12 months after initiating gender-affirming hormone therapy, serum creatinine increased by 0.15 mg/dl (95% confidence interval, 0.00 to 0.29) in 370 transgender men and decreased by -0.05 mg/dl (95% confidence interval, -0.16 to 0.05) in 361 transgender women. No study reported the effect of gender-affirming hormone therapy on albuminuria, proteinuria, cystatin C, or measured GFR. CONCLUSIONS: Gender-affirming hormone therapy increases serum creatinine in transgender men and does not affect serum creatinine in transgender women. The effect on gender-affirming hormone therapy on other kidney function biomarkers and measured GFR is unknown. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: Change in Kidney Function Biomarkers in Transgender Persons on Gender Affirmation Hormone Therapy-A Systematic Review and Meta-Analysis, CRD42020214248.