Plasma Soluble Tumor Necrosis Factor Receptor Concentrations and Clinical Events After Hospitalization: Findings From the ASSESS-AKI and ARID Studies.

RATIONALE & OBJECTIVE: The role of plasma soluble tumor necrosis factor receptor 1 (sTNFR1) and sTNFR2 in the prognosis of clinical events after hospitalization with or without acute kidney injury (AKI) is unknown. STUDY DESIGN: Prospective cohort. SETTING & PARTICIPANTS: Hospital survivors from the ASSESS-AKI (Assessment, Serial Evaluation, and Subsequent Sequelae of Acute Kidney Injury) and ARID (AKI Risk in Derby) studies with and without AKI during the index hospitalization who had baseline serum samples for biomarker measurements. PREDICTORS: We measured sTNFR1 and sTNFR2 from plasma samples obtained 3 months after discharge. OUTCOMES: The associations of biomarkers with longitudinal kidney disease incidence and progression, heart failure, and death were evaluated. ANALYTICAL APPROACH: Cox proportional hazard models. RESULTS: Among 1,474 participants with plasma biomarker measurements, 19% had kidney disease progression, 14% had later heart failure, and 21% died during a median follow-up of 4.4 years. For the kidney outcome, the adjusted HRs (AHRs) per doubling in concentration were 2.9 (95% CI, 2.2-3.9) for sTNFR1 and 1.9 (95% CI, 1.5-2.5) for sTNFR2. AKI during the index hospitalization did not modify the association between biomarkers and kidney events. For heart failure, the AHRs per doubling in concentration were 1.9 (95% CI, 1.4-2.5) for sTNFR1 and 1.5 (95% CI, 1.2-2.0) for sTNFR2. For mortality, the AHRs were 3.3 (95% CI, 2.5-4.3) for sTNFR1 and 2.5 (95% CI, 2.0-3.1) for sTNFR2. The findings in ARID were qualitatively similar in terms of the magnitude of association between biomarkers and outcomes. LIMITATIONS: Different biomarker platforms and AKI definitions; limited generalizability to other ethnic groups. CONCLUSIONS: Plasma sTNFR1 and sTNFR2 measured 3 months after hospital discharge were independently associated with clinical events regardless of AKI status during the index admission. sTNFR1 and sTNFR2 may assist with the risk stratification of patients during follow-up.

Dipping Status, Ambulatory Blood Pressure Control, Cardiovascular Disease, and Kidney Disease Progression: A Multicenter Cohort Study of CKD.

RATIONALE & OBJECTIVE: Ambulatory blood pressure (BP) monitoring allows concurrent evaluation of BP control and nocturnal BP dipping status, both related to adverse outcomes. However, few studies have assessed the prognostic role of combining information on dipping status and achieved ambulatory BP in patients with chronic kidney disease (CKD). STUDY DESIGN: Prospective observational cohort study. SETTING & PARTICIPANTS: 906 patients with hypertension and CKD attending 1 of 3 Italian nephrology clinics. EXPOSURE: Four groups were defined by simultaneously classifying systolic ambulatory BP levels as being at goal (daytime SBP <135 and nighttime SBP <120 mm Hg) or above goal, and the presence or absence of nocturnal dipping (nighttime to daytime SBP ratio of <0.9 versus ≥0.9). OUTCOME: The composite of time to initiation of maintenance dialysis or estimated glomerular filtration rate (eGFR) decline ≥50%, and the composite of fatal and nonfatal cardiovascular events. ANALYTICAL APPROACH: Multivariable Cox proportional hazards models were used to estimate risks of kidney disease progression and cardiovascular disease in the 4 exposure groups where nocturnal dipping with systolic ambulatory BP at goal was the reference group. RESULTS: The mean patient age was 63.8 years, 61% were male, and 26.4% had diabetes; eGFR was 41.1 ± 20.8 mL/min/1.73 m2. The dipping prevalence in each of the 4 groups was as follows: nocturnal dipping with ambulatory BP at goal, 18.6%; no nocturnal dipping with ambulatory BP at goal, 20.5%; nocturnal dipping with ambulatory BP above goal, 11.8%; and no nocturnal dipping with ambulatory BP above goal, 49.1%. Among patients with ambulatory BP above goal, the risk of cardiovascular events was greater in the absence (HR, 2.79 [95% CI, 1.64-4.75]) and presence (HR, 2.05 [95% CI, 1.10-3.84]) of nocturnal dipping. The same held true for risk of kidney disease progression (HRs of 2.40 [95% CI, 1.58-3.65] and 2.11 [95% CI, 1.28-3.48] in the absence and presence of nocturnal dipping, respectively). Patients at the ambulatory BP goal but who did not experience nocturnal dipping had an increased risk of the cardiovascular end point (HR, 2.06 [95% CI, 1.15-3.68]) and the kidney disease progression outcome (HR, 1.82 [95% CI, 1.17-2.82]). LIMITATIONS: Lack of a diverse cohort (all those enrolled were White). Residual uncontrolled confounding. CONCLUSIONS: Systolic ambulatory BP above goal or the absence of nocturnal dipping, regardless of ambulatory BP, is associated with higher risks of cardiovascular disease and kidney disease progression among patients with CKD. PLAIN-LANGUAGE SUMMARY: Among patients with chronic kidney disease (CKD), ambulatory blood pressure (BP) monitoring improves the identification of individuals at high risk of clinical disease outcomes. Those with uncontrolled ambulatory BP are known to have a higher risk of developing cardiovascular disease and kidney disease progression, particularly when their ambulatory BP does not decline by at least 10% at night. Whether this is also true for patients with presence of optimal ambulatory BP levels but a BP pattern of no nighttime decline is largely unknown. We measured ambulatory BP in 900 Italian patients with CKD and followed them for several years. We found that, independent of ambulatory BP level, the absence of nighttime reductions in BP was associated with worsening of CKD and more frequent cardiovascular events. The absence of nighttime declines in BP is an independent risk factor for adverse events among patients with CKD. Future studies are needed to examine whether treating the absence of nighttime declines in BP improves clinical outcomes.

Social determinants of health and the transition from advanced chronic kidney disease to kidney failure.

BACKGROUND: The transition from chronic kidney disease (CKD) to kidney failure is a vulnerable time for patients, with suboptimal transitions associated with increased morbidity and mortality. Whether social determinants of health are associated with suboptimal transitions is not well understood. METHODS: This retrospective cohort study included 1070 patients with advanced CKD who were referred to the Ottawa Hospital Multi-Care Kidney Clinic and developed kidney failure (dialysis or kidney transplantation) between 2010 and 2021. Social determinant information, including education level, employment status and marital status, was collected under routine clinic protocol. Outcomes surrounding suboptimal transition included inpatient (versus outpatient) dialysis starts, pre-emptive (versus delayed) access creation and pre-emptive kidney transplantation. We examined the association between social determinants of health and suboptimal transition outcomes using multivariable logistic regression. RESULTS: The mean age and estimated glomerular filtration rate were 63 years and 18 ml/min/1.73 m2, respectively. Not having a high school degree was associated with higher odds for an inpatient dialysis start compared with having a college degree {odds ratio [OR] 1.71 [95% confidence interval (CI) 1.09-2.69]}. Unemployment was associated with higher odds for an inpatient dialysis start [OR 1.85 (95% CI 1.18-2.92)], lower odds for pre-emptive access creation [OR 0.53 (95% CI 0.34-0.82)] and lower odds for pre-emptive kidney transplantation [OR 0.48 (95% CI 0.24-0.96)] compared with active employment. Being single was associated with higher odds for an inpatient dialysis start [OR 1.44 (95% CI 1.07-1.93)] and lower odds for pre-emptive access creation [OR 0.67 (95% CI 0.50-0.89)] compared with being married. CONCLUSIONS: Social determinants of health, including education, employment and marital status, are associated with suboptimal transitions from CKD to kidney failure.

Survival Benefit of Kidney Transplantation in Patients With End-Stage Kidney Disease and Prior Acute Myocardial Infarction.

Patients with end stage kidney disease (ESKD) and a previous acute myocardial infarction (AMI) have less access to KT. Data on ESKD patients with an AMI history who underwent first KT or dialysis between January 2007 and December 2018 were extracted from the Korean National Health Insurance Service. Patients who underwent KT (n = 423) were chronologically matched in a 1:3 ratio with those maintained on dialysis (n = 1,269) at the corresponding dates, based on time-conditional propensity scores. The 1, 5, and 10 years cumulative incidences for all-cause mortality were 12.6%, 39.1%, and 60.1% in the dialysis group and 3.1%, 7.2%, and 14.5% in the KT group. Adjusted hazard ratios (HRs) of KT versus dialysis were 0.17 (95% confidence interval [CI], 0.12-0.24; p < 0.001) for mortality and 0.38 (95% CI, 0.23-0.51; p < 0.001) for major adverse cardiovascular events (MACE). Of the MACE components, KT was most protective against cardiovascular death (HR, 0.23; 95% CI, 0.12-0.42; p < 0.001). Protective effects of KT for all-cause mortality and MACE were consistent across various subgroups, including patients at higher risk (e.g., age >65 years, recent AMI [<6 months], congestive heart failure). KT is associated with lower all-cause mortality and MACE than maintenance dialysis patients with a prior AMI.

Treatment inequity in antiplatelet therapy for ischaemic heart disease in patients with advanced chronic kidney disease: releasing the evidence vacuum.

Chronic kidney disease (CKD) is a global health problem and an independent risk factor for cardiovascular morbidity and mortality. Despite evidence-based therapies significantly improving cardiovascular mortality outcomes in the general population and those with non-dialysis-dependent CKD, this risk reduction has not translated to patients with end-stage kidney disease (ESKD). Absent from all major antiplatelet trials, this has led to insufficient safety data for P2Y12 inhibitor prescriptions and treatment inequity in this subpopulation. This review article presents an overview of the progression of research in understanding antiplatelet therapy for ischaemic heart disease in patients with advanced CKD (defined as eGFR <30 mL/min/1.73 m2). Beyond trial recruitment strategies, new approaches should focus on registry documentation by CKD stage, risk stratification with biomarkers associated with inflammation and haemorrhage and building a knowledge base on optimal duration of dual and single antiplatelet therapies.

What is the context? Patients with kidney disease are more likely to experience a heart attack than those without.Those with advanced kidney disease have a higher risk of death following a heart attack.Over the past two decades, advances in treatment following a heart attack have reduced the risk of death, however this has not translated to those with advanced kidney disease.Progression of kidney disease influences antiplatelet (e.g. clopidogrel) treatment efficacy.What is new?This contemporary review analyses registry and trial data to highlight some of the issues surrounding treatment inequity in patients with advanced kidney disease.This article describes potential mechanisms by which progression of kidney disease can influence clotting, bleeding and antiplatelet treatments.What is the impact?Further research into antiplatelet therapy for patients with advanced kidney disease is required.Registry and trial data can improve upon classification of kidney disease for future research.Future trials in antiplatelet therapy for advanced kidney disease are anticipated.

Update of dialysis initiation timing in end stage kidney disease patients: is it a resolved question? A systematic literature review.

BACKGROUND: The exact optimal timing of dialysis for ESKD patients remains unknown. This study systematically reviewed the available evidence with regard to the optimal initiation of maintenance dialysis in ESKD patients. METHODS: An electronic search was performed in Embase, PubMed and the Cochrane Library in order to find studies investigating associations between variables reference to "start of dialysis" and outcomes. Quality assessment and bias assessment were performed by the Newcastle-Ottawa scale and the ROBINSI tool. Due to the heterogeneity of studies, a meta-analysis could not be performed. RESULTS: Thirteen studies were included; four studies included only haemodialysis patients, three peritoneal dialysis, six both; study outcomes included mortality, cardiovascular events, technique failure, quality of life and others. Nine studies mainly focused on the optimal GFR of maintenance dialysis initiation; five studies showed none association between GFR and mortality or other adverse outcomes, two studies showed dialysis initiation at higher GFR levels were with poor prognosis, and 2 studies showed higher GFR levels with better prognosis. Three studies paid attention to comprehensive assessment of uremic signs and/or symptoms for optimal dialysis initiation; uremic burden based on 7 uremic indicators (hemoglobin, serum albumin, blood urea nitrogen, serum creatinine, potassium, phosphorus, and bicarbonate) were not associated with mortality; another equation (combination of sex, age, serum creatinine, blood urea nitrogen, serum albumin, haemoglobin, serum phosphorus, diabetes mellitus, and heart failure) based on fuzzy mathematics to assess the timing of haemodialysis initiation was accuracy to prognose 3-year survival; the third study found that volume overload or hypertension was associated with the highest risk for subsequent mortality. Two studies compared urgent or optimal start in dialysis, a study reported increased survival in optimal start patients, another reported no differences between Urgent-Start-PD and Early-Start-PD regarding 6-month outcomes. LIMITATIONS: Heterogeneity among the studies was quite high, with differences in sample size, variable and group characteristics; no RCT studies were included, which weakened the strength of evidences. CONCLUSIONS: The criteria for dialysis initiation were varied. Most studies proved that GFR at dialysis initiation was not associated with mortality, timing of dialysis initiation should not be based on GFR, assessments of volume load and patient's tolerance to volume overload are prospective approaches.

Mortality After Home Hemodialysis Treatment Failure and Return to In-Center Hemodialysis.

RATIONALE & OBJECTIVE: Patients on home hemodialysis (HHD) may eventually return to in-center hemodialysis (ICHD) for clinical, technical, or psychosocial reasons. We studied the mortality of patients returning to ICHD after HHD, comparing it with the mortality experience among patients receiving HHD and patients receiving ICHD without prior treatment with HHD. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: All patients represented in the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) who commenced HD during 2005-2015 and were treated for >90 days. EXPOSURE: ICHD and/or HHD, and clinical characteristics at study entry. OUTCOME: Mortality and cause of death. ANALYTICAL APPROACH: A time-varying multivariate Cox proportional hazards analysis with shared frailty was implemented to explore the association between patient treatment states and mortality. Patients were censored at the time of transplantation or change in treatment modality to peritoneal dialysis. RESULTS: A total of 19,306 patients initiated HD and were treated for >90 days. The mean age of patients was 60.8 ± 15.4 (SD) years, 62% were male, and 49% had diabetes. After HHD treatment failure, adjusted mortality was increased compared with continued HHD at 0-30 days (HR, 3.93 [95% CI, 2.09-7.40]; P < 0.001), 30-90 days (HR, 3.34 [95% CI, 1.98-5.62]; P < 0.001), and >90 days (HR, 2.29 [95% CI, 1.84-2.85]; P < 0.001). LIMITATIONS: Covariates recorded at dialysis initiation, residual confounding underlying successful initiation of HHD treatment, and observational data lacking detail on cause of HHD treatment failure. CONCLUSIONS: HHD treatment failure is associated with a significant increase in mortality compared with continued HHD. This risk was present in both the early (first 30 days and 30-90 days) and late (>90 days) periods after HHD treatment failure. Further investigation into the specific causes of treatment failure and death may highlight specific high-risk patients.

Dialysis Outcomes for Children With Lupus Nephritis Compared to Children With Other Forms of Nephritis: A Retrospective Cohort Study.

RATIONALE & OBJECTIVE: Children with lupus nephritis (LN) are at high risk of developing kidney failure requiring initiation of kidney replacement therapy. This study compared outcomes among children with LN on dialysis with children with non-lupus glomerular disease and investigated risk factors for adverse outcomes among children with LN on dialysis. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Children and adolescents aged 6-20 years with LN (n = 231) and non-lupus glomerular disease (n = 1,726) who initiated maintenance dialysis 1991-2018 and were enrolled in the North American Pediatric Renal Trials and Collaborative Studies (NAPRTCS) registry. EXPOSURE: Lupus nephritis. OUTCOME: Hospitalization, mortality, and time to transplant. ANALYTICAL APPROACH: Contingency tables were used to compare hospitalizations, and multivariable cause-specific hazards models were used to compare rates of death and transplantation in children with LN compared with those with non-lupus glomerular disease. Using data from children with LN, multivariable logistic regression models were fit to evaluate the risk factors for hospitalization, and multivariable Cox regression models were fit to evaluate factors associated with kidney transplantation. RESULTS: Children with LN were more likely to be hospitalized in the first year after dialysis initiation (63.3% vs 48.6%, P < 0.001) and were less likely to receive a kidney transplant in the first 3 years after dialysis initiation (year 0-1: adjusted hazard ratio [AHR], 0.36 [95% CI, 0.23-0.57], P < 0.001; year 1-3: AHR, 0.73 [95% CI, 0.54-0.98], P = 0.04). Anemia was associated with hospitalization after dialysis initiation (adjusted OR, 4.44 [95% CI, 1.44-13.66], P = 0.01). Non-White race was associated with a lower rate of kidney transplantation (AHR, 0.47 [95% CI, 0.27-0.82], P = 0.01). LN was not associated with death while on dialysis (AHR, 1.21 [95% CI, 0.47-3.11], P = 0.7). LIMITATIONS: The NAPRTCS registry does not collect information on lupus disease activity or medication doses and has limited data on medication use. CONCLUSIONS: Children and adolescents with LN on dialysis are at higher risk for adverse outcomes including hospitalization and lower rates of kidney transplantation compared with children with non-lupus glomerular disease receiving maintenance dialysis.

Risk of Acute Kidney Injury After Hypertensive Disorders of Pregnancy: A Population-Based Cohort Study.

RATIONALE & OBJECTIVE: Even though studies have demonstrated a relationship between hypertensive disorders of pregnancy (HDPs) and chronic kidney disease, there are limited data on the risk of acute kidney injury (AKI) following HDPs. We examined the risk of AKI following the occurrence of HDPs. STUDY DESIGN: Retrospective population-based cohort study. SETTING & PARTICIPANTS: Pregnant women in Ontario, Canada, aged 14-50 years, who delivered at ≥20 weeks' gestation between April 1, 2002, and March 31, 2015. EXPOSURE: Preeclampsia, gestational hypertension, or neither. OUTCOMES: The primary outcome was AKI with receipt of dialysis (AKI-D) ≥90 days after delivery. The main secondary outcome was AKI based on a hospitalization with a diagnostic code for AKI ≥90 days after delivery. ANALYTICAL APPROACH: Time-dependent Cox proportional and cause-specific hazards models were used to evaluate the relationship between HDP and outcomes of interest. Models were adjusted for baseline and time-varying covariates. RESULTS: Our cohort comprised 1,142,656 women and 1,826,235 deliveries, of which 1.7% were associated with gestational hypertension and 4.4% with preeclampsia. After a mean follow-up of 6.7 years, there were 322 episodes of AKI-D (0.41 per 10,000 person-years) and 1,598 episodes of AKI based on diagnostic codes (2.04 per 10,000 person-years). After adjustment, neither preeclampsia nor gestational hypertension was associated with AKI-D. Preeclampsia was associated with AKI (HR, 1.22 [95% CI, 1.03-1.45]), but gestational hypertension was not. LIMITATIONS: Retrospective design and possible unmeasured confounding. Cases of HDPs and AKI may have been undetected. CONCLUSIONS: Preeclampsia was a risk factor for AKI occurring ≥90 days after delivery. Our findings suggest the potential importance of obtaining a pregnancy history as part of a comprehensive risk profile for acute kidney disease and suggest that women with a history of HDP may benefit from monitoring of kidney function.

A Cost-effectiveness Analysis of Adherence Promotion Strategies to Improve Rejection Rates in Adolescent Kidney Transplant Recipients.

RATIONALE & OBJECTIVE: Nonadherence to medical regimens increases the risk of graft loss among adolescent and young adult recipients of kidney transplants. Interventions that improve adherence may decrease rejection rates, but their perceived costs are a barrier to clinical implementation. We developed a model to assess the cost-effectiveness of an adherence promotion strategy, the Medication Adherence Promotion System (MAPS). STUDY DESIGN: Simulation-based. Data sources included published articles indexed in Medline or referenced in bibliographies of relevant English-language articles. Data on costs and outcomes were taken from a single clinical center. SETTING & POPULATION: US adolescent patients after their first kidney transplant. INTERVENTION: Usual posttransplant care versus usual care plus MAPS. OUTCOME: Effectiveness measured in quality-adjusted life years (QALYs) and costs measured in 2020 US dollars. MODEL, PERSPECTIVE, & TIMEFRAME: Markov state transition decision model. We used a health care system perspective with a lifelong time horizon. RESULTS: In the base-case analysis, MAPS was more effective and less costly than usual care. MAPS cost $9,106 per patient less than usual care and resulted in a gain of 0.32 QALYs. In probabilistic sensitivity analyses, MAPS was cost saving 100% of the time. Extending results to a program level with 100 patients, any adherence promotion intervention similar in effectiveness to MAPS would cost less than $50,000/QALY if the start-up costs were <$2.5 million and annual costs <$188,000. Strategies with costs similar to MAPS that reduce the risk of rejection by as little as 3% would also have similar cost-effectiveness. LIMITATIONS: Estimates of components and costs for MAPS were based on a single center. CONCLUSIONS: Adherence promotion strategies with costs similar to MAPS can be cost-effective as long as they reduce rejection rates by at least 3%. This model can be applied to study the cost-effectiveness of adherence promotion strategies with varying costs and outcomes.

Cancer Risk and Mortality in Patients With Kidney Disease: A Population-Based Cohort Study.

RATIONALE & OBJECTIVE: Patients with chronic kidney disease (CKD) may be at increased risk for cancer. CKD may also be associated with worse cancer outcomes. This study examined cancer incidence and mortality across the spectrum of CKD. STUDY DESIGN: Population-based cohort study. SETTING & PARTICIPANTS: All adult Ontario residents with data on estimated glomerular filtration rate (eGFR) or who were receiving maintenance dialysis or had received a kidney transplant (2007-2016). EXPOSURE: Patients were categorized as of the first date they had 2 eGFR assessments or were registered as receiving maintenance dialysis or having received a kidney transplant. eGFR levels were further categorized as ≥60, 45-59, 30-44, 15-29, and <15 mL/min/1.73 m2; the latter 4 groups are consistent with KDIGO (Kidney Disease: Improving Global Outcomes) CKD categories G3a, G3b, G4, and G5, respectively. OUTCOMES: Overall and site-specific cancer incidence and mortality. ANALYTICAL APPROACH: Fine and Gray subdistribution hazard models. RESULTS: Among 5,882,388 individuals with eGFR data, 29,809 receiving dialysis, and 4,951 having received a kidney transplant, there were 325,895 cancer diagnoses made during 29,993,847 person-years of follow-up. The cumulative incidence of cancer ranged between 10.8% and 15.3% in patients with kidney disease. Compared with patients with eGFR ≥60 mL/min/1.73 m2, adjusted hazard ratios (AHRs) for a cancer diagnosis among patients with CKD G3a, G3b, G4, and G5 were 1.08 (95% CI, 1.07-1.10), 0.99 (95% CI, 0.97-1.01), 0.85 (95% CI, 0.81-0.88), and 0.81 (95% CI, 0.73-0.90), respectively. The AHRs for patients receiving dialysis and who had received a transplant were 1.01 (95% CI, 0.96-1.07) and 1.25 (95% CI, 1.12-1.39), respectively. Patients with kidney disease had higher proportions of stage 4 cancers at diagnosis. Patients with CKD G3a, G3b, and G4 and transplant recipients had increased risks of cancer-specific mortality (AHRs of 1.27 [95% CI, 1.23-1.32], 1.29 [95% CI, 1.24-1.35], 1.25 [95% CI, 1.18-1.33], and 1.48 [95% CI, 1.18-1.87], respectively). The risks of bladder and kidney cancers and multiple myeloma were particularly increased in CKD, and mortality from these malignancies increased with worsening kidney function. LIMITATIONS: Possible unmeasured confounding and limited ability to infer causal associations. CONCLUSIONS: Cancer incidence in the setting of kidney disease is substantial. Cancer risk was increased in mild to moderate CKD and among transplant recipients, but not in advanced kidney disease. Cancer-related mortality was significantly higher among patients with kidney disease, particularly urologic cancers and myeloma. Strategies to detect and manage these cancers in the CKD population are needed.

A Predictive Model for Progression of CKD to Kidney Failure Based on Routine Laboratory Tests.

RATIONALE & OBJECTIVE: Stratification of chronic kidney disease (CKD) patients at risk for progressing to kidney failure requiring kidney replacement therapy (KFRT) is important for clinical decision-making and trial enrollment. STUDY DESIGN: Four independent prospective observational cohort studies. SETTING & PARTICIPANTS: The development cohort comprised 4,915 CKD patients, and 3 independent validation cohorts comprised a total of 3,063. Patients were observed for approximately 5 years. EXPOSURE: 22 demographic, anthropometric, and laboratory variables commonly assessed in CKD patients. OUTCOME: Progression to KFRT. ANALYTICAL APPROACH: A least absolute shrinkage and selection operator (LASSO) Cox proportional hazards model was fit to select laboratory variables that best identified patients at high risk for KFRT. Model discrimination and calibration were assessed and compared against the 4-variable Tangri (T4) risk equation both in a resampling approach within the development cohort and in the validation cohorts using cause-specific concordance (C) statistics, net reclassification improvement, and calibration graphs. RESULTS: The newly derived 6-variable risk score (Z6) included serum creatinine, albumin, cystatin C, and urea, as well as hemoglobin and the urinary albumin-creatinine ratio. In the the resampling approach, Z6 achieved a median C statistic of 0.909 (95% CI, 0.868-0.937) at 2 years after the baseline visit, whereas the T4 achieved a median C statistic of 0.855 (95% CI, 0.799-0.915). In the 3 independent validation cohorts, the Z6C statistics were 0.894, 0.921, and 0.891, whereas the T4C statistics were 0.882, 0.913, and 0.862. LIMITATIONS: The Z6 was both derived and tested only in White European cohorts. CONCLUSIONS: A new risk equation based on 6 routinely available laboratory tests facilitates identification of patients with CKD who are at high risk of progressing to KFRT.

KDOQI US Commentary on the 2021 KDIGO Clinical Practice Guideline for the Management of Blood Pressure in CKD.

The Kidney Disease Outcomes Quality Initiative (KDOQI) convened a work group to review the 2021 KDIGO (Kidney Disease: Improving Global Outcomes) guideline for the management of blood pressure in chronic kidney disease (CKD). This commentary is the product of that work group and presents the recommendations and practice points from the KDIGO guideline in the context of US clinical practice. A critical addition to the KDIGO guideline is the recommendation for accurate assessment of blood pressure using standardized office blood pressure measurement. In the general adult population with CKD, KDIGO recommends a goal systolic blood pressure less than 120 mm Hg on the basis of results from the Systolic Blood Pressure Intervention Trial (SPRINT) and secondary analyses of the Action to Control Cardiovascular Risk in Diabetes-Blood Pressure (ACCORD-BP) trial. The KDOQI work group agreed with most of the recommendations while highlighting the weak evidence base especially for patients with diabetes and advanced CKD.

Integrating Patient Activation Into Dialysis Care.

Patient activation, the measure of patients' readiness and willingness to manage their own health care, is low among people receiving in-center hemodialysis, which is exacerbated because such centers are commonly set up for patients to passively receive care. In our pursuit of person-centered care and value-based medicine, enabling patients to take a more active role in their care can lead to healthy behaviors, with subsequent reductions in individual burden and costs to the health care system. To improve patient activation, we need to embrace a patient-first approach and combine it with ways to equip patients to thrive with self-management. This requires changes in the training of the health care team as well as changes in care delivery models, promoting interventions such as health coaching and peer mentoring, while leveraging technology to enable self-access to records, self-monitoring, and communication with providers. We also need health care policies that encourage a focus on patient-identified goals, including more attention to patient-reported outcomes. In this article, we review the current status of patient activation in dialysis patients, outline some of the available interventions, and propose steps to change the dynamics of the current system to move toward a more active role for patients in their care.

A Unifying Approach for GFR Estimation: Recommendations of the NKF-ASN Task Force on Reassessing the Inclusion of Race in Diagnosing Kidney Disease.

BACKGROUND: In response to a national call for re-evaluation of the use of race in clinical algorithms, the National Kidney Foundation (NKF) and the American Society of Nephrology (ASN) established a Task Force to reassess inclusion of race in the estimation of glomerular filtration rate (GFR) in the United States and its implications for diagnosis and management of patients with, or at risk for, kidney diseases. PROCESS & DELIBERATIONS: The Task Force organized its activities over 10 months in phases to (1) clarify the problem and evidence regarding GFR estimating equations in the United States (described previously in an interim report), and, in this final report, (2) evaluate approaches to address use of race in GFR estimation, and (3) provide recommendations. We identified 26 approaches for the estimation of GFR that did or did not consider race and narrowed our focus, by consensus, to 5 of those approaches. We holistically evaluated each approach considering 6 attributes: assay availability and standardization; implementation; population diversity in equation development; performance compared with measured GFR; consequences to clinical care, population tracking, and research; and patient centeredness. To arrive at a unifying approach to estimate GFR, we integrated information and evidence from many sources in assessing strengths and weaknesses in attributes for each approach, recognizing the number of Black and non-Black adults affected. RECOMMENDATIONS: (1) For US adults (>85% of whom have normal kidney function), we recommend immediate implementation of the CKD-EPI creatinine equation refit without the race variable in all laboratories in the United States because it does not include race in the calculation and reporting, included diversity in its development, is immediately available to all laboratories in the United States, and has acceptable performance characteristics and potential consequences that do not disproportionately affect any one group of individuals. (2) We recommend national efforts to facilitate increased, routine, and timely use of cystatin C, especially to confirm estimated GFR in adults who are at risk for or have chronic kidney disease, because combining filtration markers (creatinine and cystatin C) is more accurate and would support better clinical decisions than either marker alone. If ongoing evidence supports acceptable performance, the CKD-EPI eGFR-cystatin C (eGFRcys) and eGFR creatinine-cystatin C (eGFRcr-cys_R) refit without the race variables should be adopted to provide another first-line test, in addition to confirmatory testing. (3) Research on GFR estimation with new endogenous filtration markers and on interventions to eliminate race and ethnic disparities should be encouraged and funded. An investment in science is needed for newer approaches that generate accurate, unbiased, and precise GFR measurement and estimation without the inclusion of race, and that promote health equity and do not generate disparate care. IMPLEMENTATION: This unified approach, without specification of race, should be adopted across the United States. High-priority and multistakeholder efforts should implement this solution.

Association of Uremic Solutes With Cardiovascular Death in Diabetic Kidney Disease.

RATIONALE & OBJECTIVE: Cardiovascular disease (CVD) is a major cause of mortality among people with diabetic kidney disease (DKD). The pathophysiology is inadequately explained by traditional CVD risk factors. The uremic solutes trimethylamine-N-oxide (TMAO) and asymmetric and symmetric dimethylarginine (ADMA, SDMA) have been linked to CVD in kidney failure with replacement therapy (KFRT), but data are limited in populations with diabetes and less severe kidney disease. STUDY DESIGN: Observational cohort. SETTINGS & PARTICIPANTS: Random subcohort of 555 REGARDS (Reasons for Geographic and Racial Differences in Stroke) study participants with diabetes and estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 at study entry. EXPOSURE: ADMA, SDMA, and TMAO assayed by liquid chromatography-mass spectrometry in plasma and urine. OUTCOME: Cardiovascular mortality (primary outcome); all-cause mortality and incident KFRT (secondary outcomes). ANALYTICAL APPROACH: Plasma concentrations and ratios of urine to plasma concentrations of ADMA, SDMA, and TMAO were tested for association with outcomes. Adjusted Cox regression models were fitted and hazard ratios of outcomes calculated per standard deviation and per doubling, and as interquartile comparisons. RESULTS: The mean baseline eGFR was 44 mL/min/1.73 m2. Cardiovascular death, overall mortality, and KFRT occurred in 120, 285, and 89 participants, respectively, during a mean 6.2 years of follow-up. Higher plasma ADMA and SDMA (HRs of 1.20 and 1.28 per 1-SD greater concentration), and lower ratios of urine to plasma concentrations of ADMA, SDMA, and TMAO (HRs per halving of 1.53, 1.69, and 1.38) were associated with cardiovascular mortality. Higher plasma concentrations of ADMA, SDMA, and TMAO (HRs of 1.31, 1.42, and 1.13 per 1-SD greater concentration) and lower urine to plasma ratios of ADMA, SDMA, and TMAO (HRs per halving of 1.34, 1.37, and 1.26) were associated with all-cause mortality. Higher plasma ADMA and SDMA were associated with incident KFRT by categorical comparisons (HRs of 2.75 and 2.96, comparing quartile 4 to quartile 1), but not in continuous analyses. LIMITATIONS: Single cohort, restricted to patients with diabetes and eGFR < 60 mL/min/1.73 m2, potential residual confounding by GFR, no dietary information. CONCLUSIONS: Higher plasma concentrations and lower ratios of urine to plasma concentrations of uremic solutes were independently associated with cardiovascular and all-cause mortality in DKD. Associations of ratios of urine to plasma concentrations with mortality suggest a connection between renal uremic solute clearance and CVD pathogenesis.

Mobility in Older Adults Receiving Maintenance Hemodialysis: A Qualitative Study.

RATIONALE & OBJECTIVE: For older adults, maintaining mobility is a major priority, especially for those with advanced chronic diseases like kidney failure. However, our understanding of the factors affecting mobility in older adults receiving maintenance hemodialysis is limited. STUDY DESIGN: Descriptive qualitative study. SETTING & PARTICIPANTS: Using purposive sampling, we recruited (1) persons aged≥60 years receiving maintenance hemodialysis; and (2) care partners (≥18 years) providing regular support to an older adult receiving hemodialysis. During a single in-person home visit, we assessed mobility using the Short Physical Performance Battery (SPPB) and conducted individual one-on-one interviews regarding important personal factors related to mobility. ANALYTICAL APPROACH: Descriptive statistics were used for demographic and SPPB data. Transcripts underwent thematic coding, informed by the International Classification of Function framework of mobility. We used conceptual content analysis to inductively extract themes and subthemes. RESULTS: We enrolled 31 older adults receiving hemodialysis (42% female, 68% Black) with a mean age of 73±8 years and mean dialysis vintage of 4.6±3.5 years; their mean SPPB score was 3.6±2.8 points. Among 12 care partners (75% female, 33% Black), the mean age was 54±16 years and mean SPPB score was 10.1±2.4 points. Major themes extracted were (1) mobility represents independence; (2) mobility is precarious; (3) limitations in mobility cause distress; (4) sources of encouragement and motivation are critical; and (5) adaptability is key. LIMITATIONS: Modest sample from single geographic area. CONCLUSIONS: For older adults receiving hemodialysis, mobility is severely limited and is often precarious in nature, causing distress. Older adults receiving hemodialysis and their care partners have identified sources of encouragement and motivation for mobility, and cite an adaptable mindset as important. Future studies should conceptualize mobility as a variable condition and build on this outlook of adaptability in the development of interventions.

Epidemiology and Risk Factors for Hemodialysis Access-Associated Infections in Children: A Prospective Cohort Study From the SCOPE Collaborative.

RATIONALE & OBJECTIVE: Infections cause significant morbidity and mortality for children receiving maintenance hemodialysis (HD). The Standardizing Care to Improve Outcomes in Pediatric End-Stage Kidney Disease (SCOPE) Collaborative is a quality-improvement initiative aimed at reducing dialysis-associated infections by implementing standardized care practices. This study describes patient-level risk factors for catheter-associated bloodstream infections (CA-BSIs) and examines the association between dialysis center-level compliance with standardized practices and risk of CA-BSI. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: Children enrolled in SCOPE between June 2013 and July 2019. EXPOSURES: Data were collected on patient characteristics and center-level compliance with HD catheter care practices across the study period. Centers were categorized as consistent, dynamic (improved compliance over the study period), or inconsistent performers based on frequency of compliance audit submission and changes in compliance with HD care practices over time. OUTCOME: CA-BSIs. ANALYTICAL APPROACH: Generalized linear mixed models were used to evaluate (1) patient-level risk factors for CA-BSI and (2) associations between change in center-level compliance and CA-BSIs. RESULTS: The cohort included 1,277 children from 35 pediatric dialysis centers; 1,018 (79.7%) had a catheter and 259 (20.3%) had an arteriovenous fistula or graft. Among children with a catheter, mupirocin use at the catheter exit site was associated with an increased rate of CA-BSIs (rate ratio [RR], 4.45; P = 0.004); the use of no antibiotic agent at the catheter exit site was a risk factor of borderline statistical significance (RR, 1.79; P = 0.05). Overall median compliance with HD catheter care practices was 87.5% (IQR, 77.3%-94.0%). Dynamic performing centers showed a significant decrease in CA-BSI rates over time (from 2.71 to 0.71 per 100 patient-months; RR, 0.98; P < 0.001), whereas no significant change in CA-BSI rates was detected among consistent or inconsistent performers. LIMITATIONS: Lack of data on adherence to HD care practices on the individual patient level. CONCLUSIONS: Improvement in compliance with standardized HD care practices over time may lead to a reduction in dialysis-associated infections.

Associations of Plasma Biomarkers of Inflammation, Fibrosis, and Kidney Tubular Injury With Progression of Diabetic Kidney Disease: A Cohort Study.

RATIONALE & OBJECTIVE: Most circulating biomarkers of chronic kidney disease (CKD) progression focus on factors reflecting glomerular filtration. Few biomarkers capture nonglomerular pathways of kidney injury or damage, which may be particularly informative in populations at high risk for CKD progression such as individuals with diabetes. STUDY DESIGN: Cohort study. SETTING & PARTICIPANTS: 594 participants (mean age, 70 years; 53% women) of the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study who had diabetes and an estimated glomerular filtration rate (eGFR)<60mL/min/1.73m2 at baseline. EXPOSURES: Plasma biomarkers of inflammation/fibrosis (TNFR1 and TNFR2, suPAR, MCP-1, YKL-40) and tubular injury (KIM-1) measured at the baseline visit. OUTCOMES: Incident kidney failure with replacement therapy (KFRT). ANALYTICAL APPROACH: Cox proportional hazards regression and least absolute shrinkage and selection operator regression adjusted for established risk factors for kidney function decline, baseline eGFR, and urinary albumin-creatinine ratio (UACR). RESULTS: A total of 98 KFRT events were observed over a mean of 6.2±3.5 (standard deviation) years of follow-up. Plasma biomarkers were modestly associated with baseline eGFR (correlation coefficients ranging from-0.08 to-0.65) and UACR (0.14 to 0.56). In individual biomarker models adjusted for eGFR, UACR, and established risk factors, hazard ratios for incident KFRT per 2-fold higher biomarker concentrations were 1.52 (95% CI, 1.25-1.84) for plasma KIM-1, 1.54 (95% CI, 1.08-2.21) for TNFR1, 1.91 (95% CI, 1.16-3.14) for TNFR2, and 1.39 (95% CI, 1.05-1.84) for YKL-40. In least absolute shrinkage and selection operator regression models accounting for biomarkers in parallel, plasma KIM-1 and TNFR1 remained associated with incident KFRT. LIMITATIONS: Single biomarker measurement, lack of follow-up eGFR assessments. CONCLUSIONS: Individual plasma markers of inflammation/fibrosis (TNFR1, TNFR2, YKL-40) and tubular injury (KIM-1) were associated with risk of incident KFRT in adults with diabetes and an eGFR<60mL/min/1.73m2 after adjustment for established risk factors.

Cardiopulmonary exercise testing in patients with end-stage kidney disease: principles, methodology and clinical applications of the optimal tool for exercise tolerance evaluation.

Chronic kidney disease (CKD), especially end-stage kidney disease (ESKD), is associated with an increased risk for cardiovascular events and all-cause mortality. Exercise intolerance as well as reduced cardiovascular reserve is extremely common in patients with CKD. Cardiopulmonary exercise testing (CPET) is a non-invasive, dynamic technique that provides an integrative evaluation of cardiovascular, pulmonary, neuropsychological and metabolic function during maximal or submaximal exercise, allowing the evaluation of functional reserves of these systems. This assessment is based on the principle that system failure typically occurs when the system is under stress and thus CPET is currently considered to be the gold standard for identifying exercise limitation and differentiating its causes. It has been widely used in several medical fields for risk stratification, clinical evaluation and other applications, but its use in everyday practice for CKD patients is scarce. This article describes the basic principles and methodology of CPET and provides an overview of important studies that utilized CPET in patients with ESKD, in an effort to increase awareness of CPET capabilities among practicing nephrologists.