Association between Acute Declines in Estimated Glomerular Filtration Rate during Renin-Angiotensin System Inhibition and Risk of Adverse Outcomes.

BACKGROUND: Declines in glomerular filtration rate (GFR) occur commonly when renin-angiotensin system (RAS) inhibitors are started. Our objective was to determine the relation between declines in estimated GFR during trials of RAS inhibition and kidney outcomes. METHODS: We included participants with CKD (estimated GFR<60 mL/min/1.73m2) from 16 trials of RAS inhibition. The exposure was subacute declines in estimated GFR expressed as % change between randomization and month 3, and in the subset of trials with data available, we also examined % change in eGFR between randomization and month 1. The primary outcome was kidney failure with replacement therapy. Cox proportional hazards models were used to examine the association between subacute declines in eGFR and risk of kidney failure. We used spline models to identify the threshold of change in eGFR below which RAS inhibition was favorable (conservatively comparing a given decline in eGFR with RAS inhibition to no decline in the comparator). RESULTS: 11,800 individuals with mean eGFR 43 (SD 11) mL/min/1.73m2 and median urine albumin/creatinine ratio of 362 mg/g (IQR 50, 1367) were included, and 1,162 (10%) developed kidney failure. The threshold of decline in eGFR that favored use of RAS inhibitors for kidney failure was estimated to be up to 13% (95%CI 8%, 17%) over a 3-month interval and up to 21% (95%CI 15%, 27%) over a 1-month interval after starting RAS inhibitors. CONCLUSIONS: In people treated with RAS inhibitors, ≤ 13% decline in eGFR over a 3-month period or ≤21% decline over a 1-month period was associated with lower risk of kidney failure compared with no decline with the use of placebo or other agents.

Glomerular Filtration Rate Estimation Using ß2-Microglobulin and ß-Trace Protein in Adults With Solid Tumors: A Prospective Cross-Sectional Study.

RATIONALE & OBJECTIVE: ß2-Microglobulin (B2M) and ß-trace protein (BTP) are novel endogenous filtration markers that may improve the accuracy of estimated glomerular filtration rate (eGFR) beyond creatinine and cystatin C (eGFRcr-cys), but they have not been assessed in patients with cancer. STUDY DESIGN: Cross-sectional analysis. SETTING & PARTICIPANTS: Prospective cohort of 1,200 patients with active solid tumors recruited between April 2015 and September 2017. EXPOSURE: CKD-EPI equations without race combining B2M and/or BTP with creatinine with or without cystatin C (2-, 3-, or 4-marker panel eGFR). OUTCOME: Performance of equations compared with eGFRcr-cys and non-GFR determinants of serum B2M and BTP (SB2M, and SBTP, respectively). Measured GFR (mGFR) was determined using the plasma clearance of chromium-51 labeled ethylenediamine tetraacetic acid (51Cr-EDTA). ANALYTICAL APPROACH: Bias was defined as the median of the differences between mGFR and eGFR, and 1-P30 was defined as the percentage of estimates that differed by more than 30% from the mGFR (1-P30). Linear regression was used to assess association of clinical and laboratory variables with SB2M, and SBTP after adjustment for mGFR. RESULTS: Mean age and mGFR were 58.8±13.2 SD years and 78.4±21.7 SD mL/min/1.73m2, respectively. Performance of the 3-marker and 4-marker panel equations was better than eGFRcr-cys (lesser bias and 1-P30). Performance of 2-marker panel equations was as good as eGFRcr-cys (lesser bias and similar 1-P30). SB2M and SBTP were not strongly influenced by cancer site. LIMITATIONS: Participants may have had better clinical performance status than the general population of patients with solid tumors. CONCLUSIONS: B2M and BTP can improve the accuracy of eGFR and may be useful as confirmatory tests in patients with solid tumors, either by inclusion in a multimarker panel equation with creatinine and cystatin C, or by substituting for cystatin C in combination with creatinine. PLAIN-LANGUAGE SUMMARY: The most accurate method to assess estimate kidney function is estimated glomerular filtration rate (eGFR) using creatinine and cystatin C (eGFRcr-cys). We studied whether using ß2-microglobulin (B2M) and/or ß-trace protein (BTP) with creatinine with or without cystatin C (2-, 3-, or 4-marker panel eGFR) might be useful in patients with active solid tumors. The performance of the 3-marker and 4-marker panel equations was better than eGFRcr-cys. Performance of 2-marker panel equations was as good as eGFRcr-cys. We conclude that B2M and BTP can improve the accuracy of eGFR and may be useful as a confirmatory test in patients with solid tumors either by inclusion in multimarker panel equation with creatinine and cystatin C or by substituting for cystatin C in combination with creatinine.

Association of Body Mass Index with Multiple Organ Failure in Hospitalized Patients with COVID-19: A Multicenter Retrospective Cohort Study.

Purpose: This study examines whether excessive adipose tissue, as measured by the body mass index (BMI), is associated with higher systemic markers of inflammation and higher risk of severe acute organ failure among patients with coronavirus disease 2019 (COVID-19). Methods: This was a multicenter retrospective cohort study of 1370 hospitalized adults (18 years or older) with COVID-19 during the first wave of the pandemic. Patient-level variables were extracted from the electronic medical record. The primary predictor variable was the BMI at time of hospital admission, in accordance with the World Health Organization classification. Multivariable logistic regression analyses examined the association of BMI with the composite of acute respiratory distress syndrome (ARDS), as defined by the use of high-flow nasal canula, non-invasive ventilation, or mechanical ventilation, severe acute kidney injury (AKI), as defined by acute dialysis requirement, or in-hospital death. Results: After adjustment for important cofounders, the BMI stratum of > 40 kg/m2 (compared to the BMI < 25 kg/m2 reference group) was associated with higher odds for the composite of ARDS, severe AKI, or in-hospital death (adjusted odds ratio [ORadj] 1.69; 95% confidence interval [CI]1.03, 2.78). As a continuous variable, BMI (per 5-kg/m2 increase) remained independently associated with the composite outcome (ORadj 1.13; 95% CI 1.03, 1.23); patients in higher BMI categories exhibited significantly higher peak levels of C-reactive protein (CRP), a systemic marker of inflammation (P = .01). In a sub-cohort of 889 patients, the association of BMI with the composite outcome was no longer significant after adjustment for the peak level of CRP. Conclusions: Among hospitalized patients with COVID-19, a higher BMI is associated with higher risk of severe organ failure or in-hospital death, which dissipates after adjustment for CRP level. This supports the hypothesis that inflammation is a downstream mediator of adipose tissue on acute organ dysfunction.

Development and Validation of the Rating of CKD Knowledge Among Older Adults (Know-CKD) With Kidney Failure.

RATIONALE & OBJECTIVE: Few older adults with kidney failure engage in shared decision making (SDM) for kidney replacement therapy. The lack of instruments to assess SDM-relevant knowledge domains may contribute to this. We assessed the reliability and validity of a new instrument, the Rating of CKD Knowledge Older Adults (Know-CKD). STUDY DESIGN: Multistage process, including a stakeholder-engaged development phase, pilot testing, and validation of a knowledge instrument using a cross-sectional survey of older adults with CKD. SETTING & PARTICIPANTS: 363 patients aged 70+years with nondialysis advanced chronic kidney disease (CKD) (estimated glomerular filtration rate [eGFR]<30mL/min/1.73m2) in Boston, Chicago, Portland, ME, and San Diego from June 2018 and January 2020. EXPOSURE: Educational level, higher literacy (Single Item Literacy Screener [SILS]) and numeracy (Subjective Numeracy Scale [SNS]), having participated in clinic-sponsored dialysis education, and self-reported "feeling informed" about options for treatment. OUTCOME: Validity and reliability of the Know-CKD instrument. ANALYTICAL APPROACH: Reliability was assessed with the Kuder-Richardson-20 coefficient. Construct validity was demonstrated by testing a priori hypotheses using t test, analysis of variance (ANOVA) tests, and linear regression analyses. RESULTS: The mean (± SD) participant age was 77.6±5.9 years, and mean eGFR was 22.7±7.2mL/min/1.73m2; 281 participants (78%) self-reported as White. The 12-item Know-CKD assessment had good reliability (Kuder-Richardson-20 reliability coefficient=0.75), and a mean score of 58.2% ± 22.3 SD. The subscales did not attain acceptable reliability. The proportion answering correctly on each item ranged from 20.1% to 91.7%. In examining construct validity, the hypothesized associations held; Know-CKD significantly associated with higher education (ß=6.98 [95% CI, 1.34-12.61], P=0.02), health literacy (ß = -12.67 [95% CI, -19.49 to-5.86], P≤0.001), numeracy per 10% higher (ß=1.85 [95% CI, 1.02-2.69], P≤0.001), and attendance at dialysis class (ß=18.28 [95% CI, 13.30-23.27], P≤0.001). These associations were also observed for the subscales except for prognosis (not associated with literacy or numeracy). LIMITATIONS: Know-CKD is only available in English and has been used only in research settings. CONCLUSIONS: For older adults facing dialysis initiation decisions, Know-CKD is a valid, reliable, and easy to administer measure of knowledge. Further research should examine the relationship of kidney disease knowledge and SDM, patient satisfaction, and clinical outcomes. PLAIN-LANGUAGE SUMMARY: The Rating of CKD Knowledge Among Older Adults (Know-CKD) study measures knowledge of chronic kidney disease (CKD) and is designed for older adults. Most existing knowledge measures for CKD focus on people of all ages and all CKD stages. This measure is useful because it will allow researchers to assess how well patient education efforts are working. Patient education is a way to help patients make decisions about their care. We describe how the measure was developed by a team of doctors, researchers, and patients, and how the measure performed among persons with advanced CKD aged 70 years and older. Know-CKD can inform efforts to improve shared decision-making research and practice for older patients with kidney disease.

CKD-EPI and EKFC GFR Estimating Equations: Performance and Other Considerations for Selecting Equations for Implementation in Adults.

SIGNIFICANCE STATEMENT: New eGFR equations from Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and European Kidney Function Consortium (EKFC) using creatinine (eGFRcr), cystatin C (eGFRcys), and both (eGFRcr-cys) have sufficient accuracy for use in clinical practice, leading to uncertainty in selecting equations for implementation. The authors evaluated performance of equations in an independent population of 4050 adults and evaluated other considerations important for implementation. They found that CKD-EPI and EKFC equations are approaching convergence, with better performance of eGFRcr-cys equations in the overall group and fewer differences among race, sex, and age subgroups than eGFRcr equations. Larger differences among eGFRcr equations reflect regional population differences in creatinine, forcing a trade-off between accuracy and uniformity in global implementation of eGFRcr equations. More widespread use of cystatin C could avoid this trade-off. BACKGROUND: New CKD-EPI and EKFC eGFR equations using eGFRcr, eGFRcys, and both (eGFRcr-cys) have sufficient accuracy for use in clinical practice. A better understanding of the equations, including their performance in race, sex and age subgroups, is important for selection of eGFR equations for global implementation. METHODS: We evaluated performance (bias and P 30 ) of equations and methods used for equation development in an independent study population comprising 4050 adults pooled from 12 studies. The mean (SD) measured GFR was 76.4 (29.6) ml/min per 1.73 m 2 and age 57.0 (17.4) years, with 1557 (38%) women and 579 (14%) Black participants. RESULTS: Coefficients for creatinine, cystatin C, age, and sex in the CKD-EPI and EKFC equations are similar. Performance of the eGFRcr-cys equations in the overall population (bias <±5 ml/min per 1.73 m 2 and P 30 >90%) was better than the eGFRcr or eGFRcys equations, with fewer differences among race, sex, and age subgroups. Differences in performance across subgroups reflected differences in diversity of source populations and use of variables for race and sex for equation development. Larger differences among eGFRcr equations reflected regional population differences in non-GFR determinants of creatinine. CONCLUSION: CKD-EPI and EKFC equations are approaching convergence. It is not possible to maximize both accuracy and uniformity in selecting one of the currently available eGFRcr equations for implementation across regions. Decisions should consider methods for equation development in addition to performance. Wider use of cystatin C with creatinine could maximize both accuracy and uniformity of GFR estimation using currently available equations.

Acute Declines in Estimated GFR in Blood Pressure Target Trials and Risk of Adverse Outcomes.

RATIONALE & OBJECTIVE: Acute decreases in glomerular filtration rate (GFR) occur commonly during intensive blood pressure (BP) lowering. Our objective was to determine the relationship between acute decreases in estimated GFR and patient outcomes. STUDY DESIGN: Retrospective observational study. SETTING & PARTICIPANTS: Participants from 4 randomized controlled trials of intensive BP lowering in chronic kidney disease (Modification of Diet in Renal Disease study, African American Study of Kidney Disease and Hypertension, Systolic Blood Pressure Intervention Trial, and Action to Control Cardiovascular Risk in Diabetes trial). EXPOSURE: A 4-category exposure defined by the level of acute decrease in estimated GFR (defined as>15% vs≤15% between baseline and month 4) and the randomization to intensive versus usual BP control. OUTCOMES: Risk of kidney replacement therapy (primary outcome), defined as the need for dialysis or transplant except in the Action to Control Cardiovascular Risk in Diabetes trial, which defined its kidney outcome as a composite occurrence of serum creatinine concentration>3.3mg/dL, kidney failure, or kidney replacement therapy. ANALYTICAL APPROACH: Multivariable Cox models. RESULTS: We included 4,473 individuals randomly assigned to intensive versus usual BP control who had a total of 351 kidney outcomes and 304 deaths during median follow-up durations of 22 and 24 months, respectively. Approximately 14% of participants exhibited an acute decrease in eGFR, 11.0% in the usual BP treatment arm and 17.8% in the intensive BP treatment arm. In adjusted models, compared with a≤15% eGFR decrease in the usual BP arm, a≤15% eGFR decrease in the intensive BP control arm was associated with lower risk of the kidney outcome (HR, 0.75; 95% CI, 0.57-0.98). In contrast, a>15% decrease in eGFR was associated with a higher risk of the kidney outcome in the usual (HR, 2.47; 95% CI, 1.80-3.38) and intensive BP treatment arms (HR, 1.99; 95% CI, 1.45-2.73) compared with a≤15% decrease in the usual BP arm. LIMITATIONS: Observational study, residual confounding. CONCLUSIONS: Decreases in eGFR of>15% in the usual and intensive BP treatment arms were associated with a higher risk of kidney outcomes compared with a≤15% decrease in the usual BP arm and may be a harbinger of adverse outcomes.

Association of Longitudinal B-Type Natriuretic Peptide Monitoring With Kidney Failure in Patients With CKD: A Cohort Study.

RATIONALE & OBJECTIVE: Both hypervolemia and hypovolemia are associated with chronic kidney disease (CKD) progression. Although longitudinal monitoring of B-type natriuretic peptide (BNP) may aid physicians' decision making about the optimization of volume status, its clinical benefit remains uncertain in CKD. This study assessed the association between BNP monitoring and the risk of incident kidney replacement therapy (KRT). STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: A total of 2,998 outpatients with stages 3-5 of nondialyzed CKD referred to the department of nephrology at an academic hospital. EXPOSURE: BNP monitoring. OUTCOME: KRT, acute kidney injury (AKI), and heart failure hospitalization. ANALYTICAL APPROACH: Marginal structural models, which create a balanced pseudo population at each time point, were applied to account for potential time-dependent confounders. Inverse probability weighted pooled logistic regression models were employed to estimate hazard ratios. RESULTS: At baseline, the median age and estimated glomerular filtration rate were 66 years and 38.1mL/min/1.73m2, respectively. During the follow-up period (median, 5.9 [IQR, 2.8-9.9] years), 449 patients required KRT, 765 had AKI, and 236 were hospitalized for heart failure. After adjustment for time-updated clinical characteristics and physician-specific practice styles, BNP monitoring was associated with lower risks of KRT (HR, 0.44 [95% CI, 0.21-0.92]), AKI (HR, 0.36 [95% CI, 0.18-0.72]), and heart failure hospitalization (HR, 0.37 [95% CI, 0.14-0.95]). The association between BNP monitoring and KRT was attenuated after additional adjustment for AKI or heart failure hospitalization as a time-varying covariate. LIMITATIONS: Residual confounding by measured and unmeasured variables or indications for BNP measurements. CONCLUSIONS: BNP monitoring was associated with a lower risk of KRT among patients with CKD that did not require dialysis. This association is potentially mediated through a reduced risk of AKI or heart failure hospitalization. PLAIN-LANGUAGE SUMMARY: Both volume overload and volume depletion are deleterious to kidney function. B-type natriuretic peptide (BNP) is a biomarker that reflects volume status not only in heart failure but also in nondialysis chronic kidney disease (CKD). Although longitudinal BNP monitoring may aid physicians' decision making about the optimization of volume status, its clinical benefit remains uncertain in CKD. In this cohort study analyzing 2,998 patients with nondialyzed CKD, BNP monitoring was associated with a lower risk of kidney replacement therapy, acute kidney injury, and heart failure hospitalization over the follow-up period. The association with kidney replacement therapy may be mediated through a reduced risk of acute kidney injury or heart failure hospitalization. BNP monitoring may aid physicians in optimal fluid management, potentially conferring better kidney outcomes.

Blood Pressure, Incident Cognitive Impairment, and Severity of CKD: Findings From the Chronic Renal Insufficiency Cohort (CRIC) Study.

RATIONALE & OBJECTIVE: Hypertension is a known risk factor for dementia and cognitive impairment. There are limited data on the relation of systolic blood pressure (SBP) and diastolic blood pressure (DBP) with incident cognitive impairment in adults with chronic kidney disease. We sought to identify and characterize the relationship among blood pressure, cognitive impairment, and severity of decreased kidney function in adults with chronic kidney disease. STUDY DESIGN: Longitudinal cohort study. SETTING & PARTICIPANTS: 3,768 participants in the Chronic Renal Insufficiency Cohort (CRIC) Study. EXPOSURE: Baseline SBP and DBP were examined as exposure variables, using continuous (linear, per 10-mm Hg higher), categorical (SBP<120 [reference], 120 to 140,>140mm Hg; DBP<70 (reference), 70 to 80, > 80mm Hg) and nonlinear terms (splines). OUTCOME: Incident cognitive impairment defined as a decline in Modified Mini-Mental State Examination (3MS) score to greater than 1 standard deviation below the cohort mean. ANALYTICAL APPROACH: Cox proportional hazard models adjusted for demographics as well as kidney disease and cardiovascular disease risk factors. RESULTS: The mean age of participants was 58±11 (SD) years, estimated glomerular filtration rate (eGFR) was 44mL/min/1.73m2 ± 15 (SD), and the median follow-up time was 11 (IQR, 7-13) years. In 3,048 participants without cognitive impairment at baseline and with at least 1 follow-up 3MS test, a higher baseline SBP was significantly associated with incident cognitive impairment only in the eGFR>45mL/min/1.73m2 subgroup (adjusted hazard ratio [AHR], 1.13 [95% CI, 1.05-1.22] per 10mm Hg higher SBP]. Spline analyses, aimed at exploring nonlinearity, showed that the relationship between baseline SBP and incident cognitive impairment was J-shaped and significant only in the eGFR>45mL/min/1.73m2 subgroup (P=0.02). Baseline DBP was not associated with incident cognitive impairment in any analyses. LIMITATIONS: 3MS test as the primary measure of cognitive function. CONCLUSIONS: Among patients with chronic kidney disease, higher baseline SBP was associated with higher risk of incident cognitive impairment specifically in those individuals with eGFR>45mL/min/1.73m2. PLAIN-LANGUAGE SUMMARY: High blood pressure is a strong risk factor for dementia and cognitive impairment in studies of adults without kidney disease. High blood pressure and cognitive impairment are common in adults with chronic kidney disease (CKD). The impact of blood pressure on the development of future cognitive impairment in patients with CKD remains unclear. We identified the relationship between blood pressure and cognitive impairment in 3,076 adults with CKD. Baseline blood pressure was measured, after which serial cognitive testing was performed over 11 years. Fourteen percent of participants developed cognitive impairment. We found that a higher baseline systolic blood pressure was associated with an increased risk of cognitive impairment. We found that this association was stronger in adults with mild-to-moderate CKD compared with those with advanced CKD.

Change in Albuminuria and GFR Slope as Joint Surrogate End Points for Kidney Failure: Implications for Phase 2 Clinical Trials in CKD.

SIGNIFICANCE STATEMENT: Changes in albuminuria and GFR slope are individually used as surrogate end points in clinical trials of CKD progression, and studies have demonstrated that each is associated with treatment effects on clinical end points. In this study, the authors sought to develop a conceptual framework that combines both surrogate end points to better predict treatment effects on clinical end points in Phase 2 trials. The results demonstrate that information from the combined treatment effects on albuminuria and GFR slope improves the prediction of treatment effects on the clinical end point for Phase 2 trials with sample sizes between 100 and 200 patients and duration of follow-up ranging from 1 to 2 years. These findings may help inform design of clinical trials for interventions aimed at slowing CKD progression. BACKGROUND: Changes in log urinary albumin-to-creatinine ratio (UACR) and GFR slope are individually used as surrogate end points in clinical trials of CKD progression. Whether combining these surrogate end points might strengthen inferences about clinical benefit is unknown. METHODS: Using Bayesian meta-regressions across 41 randomized trials of CKD progression, we characterized the combined relationship between the treatment effects on the clinical end point (sustained doubling of serum creatinine, GFR <15 ml/min per 1.73 m 2 , or kidney failure) and treatment effects on UACR change and chronic GFR slope after 3 months. We applied the results to the design of Phase 2 trials on the basis of UACR change and chronic GFR slope in combination. RESULTS: Treatment effects on the clinical end point were strongly associated with the combination of treatment effects on UACR change and chronic slope. The posterior median meta-regression coefficients for treatment effects were -0.41 (95% Bayesian Credible Interval, -0.64 to -0.17) per 1 ml/min per 1.73 m 2 per year for the treatment effect on GFR slope and -0.06 (95% Bayesian Credible Interval, -0.90 to 0.77) for the treatment effect on UACR change. The predicted probability of clinical benefit when considering both surrogates was determined primarily by estimated treatment effects on UACR when sample size was small (approximately 60 patients per treatment arm) and follow-up brief (approximately 1 year), with the importance of GFR slope increasing for larger sample sizes and longer follow-up. CONCLUSIONS: In Phase 2 trials of CKD with sample sizes of 100-200 patients per arm and follow-up between 1 and 2 years, combining information from treatment effects on UACR change and GFR slope improved the prediction of treatment effects on clinical end points.

Long-Term Changes in Estimated Glomerular Filtration Rate in Left Ventricular Assist Device Recipients: A Longitudinal Joint Model Analysis.

Background Advanced kidney disease is often a relative contraindication to left ventricular assist device (LVAD) implantation because of concerns for poor outcomes including worsening kidney disease. Data are lacking on long-term changes and sex-based differences in estimated glomerular filtration rate (eGFR), with published data limited by potential bias introduced by the competing risks of death and heart transplantation. Methods and Results We conducted a longitudinal analysis of 288 adults receiving durable continuous-flow LVADs from January 2010 to December 2017 at a single center. A joint model was constructed to evaluate change in eGFR over 2 years, the prespecified primary outcome, adjusted for the competing risks of death and heart transplantation. Median baseline eGFR was 60 mL/min per 1.73 m2 (interquartile range 42-78). At 2 years, 74 patients died and 104 received a heart transplant. In unadjusted analysis, LVAD recipients had a modest initial increase in eGFR of ≈2 mL/min per 1.73 m2 within the first 6 months after implantation, followed by a decrease in eGFR below baseline values at 1 and 2 years. Men experienced an eGFR decline of 5 to 10 mL/min per 1.73 m2 over the first year which then stabilized, while women had an ≈5 mL/min per 1.73 m2 increase in eGFR within the first 6 months followed by decline towards baseline eGFR levels (interaction P=0.005). Conclusions Estimated GFR remains relatively stable in most patients following LVAD implantation. Larger studies are needed to investigate sex-based differences in eGFR and to evaluate eGFR trajectory and mortality in LVAD recipients with lower eGFR.

Intensive BP Control in Patients with CKD and Risk for Adverse Outcomes.

SIGNIFICANCE STATEMENT: Although most guidelines recommend tightly controlling BP in patients with CKD, individuals with advanced kidney disease or severe albuminuria were not well-represented in trials examining the effect of this intervention on kidney outcomes. To examine the effect of intensive BP control on the risk of kidney outcomes in patients with CKD, the authors pooled individual-level data from seven trials. They found that overall, intensive BP control was associated with a 13% lower, but not significant, risk of a kidney outcome. However, the intervention's effect on the kidney outcome differed depending on baseline eGFR. Data from this pooled analysis suggested a benefit of intensive BP control in delaying KRT onset in patients with stages 4-5 CKD, but not necessarily in those with stage 3 CKD. BACKGROUND: The effect of intensive BP lowering (to systolic BP of <120 mm Hg) on the risk of kidney failure requiring KRT remains unclear in patients with advanced CKD. Such patients were not well represented in trials evaluating intensive BP control. METHODS: To examine the effect of intensive BP lowering on KRT risk-or when not possible, trial-defined kidney outcomes-we pooled individual-level data from seven trials that included patients with eGFR<60 ml/min per 1.73 m 2 . We performed prespecified subgroup analyses to evaluate the effect of intensive BP control by baseline albuminuria and eGFR (CKD stages 4-5 versus stage 3). RESULTS: Of 5823 trial participants, 526 developed the kidney outcome and 382 died. Overall, intensive (versus usual) BP control was associated with a lower risk of kidney outcome and death in unadjusted analyses but these findings did not achieve statistical significance. However, the intervention's effect on the kidney outcome differed depending on baseline eGFR ( P interaction=0.05). By intention-to-treat analysis, intensive (versus usual) BP control was associated with a 20% lower risk of the primary kidney outcome in those with CKD GFR stages 4-5, but not in CKD GFR stage 3. There was no interaction between intensive BP control and the severity of albuminuria for kidney outcomes. CONCLUSIONS: Data from this pooled analysis of seven trials suggest a benefit of intensive BP control in delaying KRT onset in patients with stages 4-5 CKD but not necessarily with stage 3 CKD. These findings suggest no evidence of harm from intensive BP control, but also point to the need for future trials of BP targets focused on populations with advanced kidney disease. PODCAST: This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast/JASN/2023_02_27_JASN0000000000000060.mp3.

Effectiveness of an Intervention to Improve Decision Making for Older Patients With Advanced Chronic Kidney Disease : A Randomized Controlled Trial.

BACKGROUND: Older patients with advanced chronic kidney disease (CKD) face difficult decisions about managing kidney failure, frequently experiencing decisional conflict, regret, and treatment misaligned with preferences. OBJECTIVE: To assess whether a decision aid about kidney replacement therapy improved decisional quality compared with usual care. DESIGN: Multicenter, randomized, controlled trial. (ClinicalTrials.gov: NCT03522740). SETTING: 8 outpatient nephrology clinics associated with 4 U.S. centers. PARTICIPANTS: English-fluent patients, 70 years and older with nondialysis CKD stages 4 to 5 recruited from 2018 to 2020. INTERVENTION: DART (Decision-Aid for Renal Therapy) is an interactive, web-based decision aid for older adults with CKD. Both groups received written education about treatments. MEASUREMENTS: Change in the decisional conflict scale (DCS) score from baseline to 3, 6, 12, and 18 months. Secondary outcomes included change in prognostic and treatment knowledge and change in uncertainty. RESULTS: Among 400 participants, 363 were randomly assigned: 180 to usual care, 183 to DART. Decisional quality improved with DART with mean DCS declining compared with control (mean difference, -8.5 [95% CI, -12.0 to -5.0]; P < 0.001), with similar findings at 6 months, attenuating thereafter. At 3 months, knowledge improved with DART versus usual care (mean difference, 7.2 [CI, 3.7 to 10.7]; P < 0.001); similar findings at 6 months were modestly attenuated at 18 months (mean difference, 5.9 [CI, 1.4 to 10.3]; P = 0.010). Treatment preferences changed from 58% "unsure" at baseline to 28%, 20%, 23%, and 14% at 3, 6, 12, and 18 months, respectively, with DART, versus 51% to 38%, 35%, 32%, and 18% with usual care. LIMITATION: Latinx patients were underrepresented. CONCLUSION: DART improved decision quality and clarified treatment preferences among older adults with advanced CKD for 6 months after the DART intervention. PRIMARY FUNDING SOURCE: Patient-Centered Outcomes Research Institute (PCORI).

National Projections for Clinical Implications of Race-Free Creatinine-Based GFR Estimating Equations.

BACKGROUND: The National Kidney Foundation and American Society of Nephrology Task Force on Reassessing the Inclusion of Race in Diagnosing Kidney Disease recently recommended a new race-free creatinine-based equation for eGFR. The effect on recommended clinical care across race and ethnicity groups is unknown. METHODS: We analyzed nationally representative cross-sectional questionnaires and medical examinations from 44,360 participants collected between 2001 and 2018 by the National Health and Nutrition Examination Survey. We quantified the number and proportion of Black, White, Hispanic, and Asian/Other adults with guideline-recommended changes in care. RESULTS: The new equation, if applied nationally, could assign new CKD diagnoses to 434,000 (95% confidence interval [CI], 350,000 to 517,000) Black adults, reclassify 584,000 (95% CI, 508,000 to 667,000) to more advanced stages of CKD, restrict kidney donation eligibility for 246,000 (95% CI, 189,000 to 303,000), expand nephrologist referrals for 41,800 (95% CI, 19,800 to 63,800), and reduce medication dosing for 222,000 (95% CI, 169,000 to 275,000). Among non-Black adults, these changes may undo CKD diagnoses for 5.51 million (95% CI, 4.86 million to 6.16 million), reclassify 4.59 million (95% CI, 4.28 million to 4.92 million) to less advanced stages of CKD, expand kidney donation eligibility for 3.96 million (95% CI, 3.46 million to 4.46 million), reverse nephrologist referral for 75,800 (95% CI, 35,400 to 116,000), and reverse medication dose reductions for 1.47 million (95% CI, 1.22 million to 1.73 million). The racial and ethnic mix of the populations used to develop eGFR equations has a substantial effect on potential care changes. CONCLUSION: The newly recommended 2021 CKD-EPI creatinine-based eGFR equation may result in substantial changes to recommended care for US patients of all racial and ethnic groups.

Factors Associated with Severity of Acute Kidney Injury and Adverse Outcomes in Critically Ill Patients with COVID-19.

BACKGROUND: Acute kidney injury (AKI) is a well-recognized complication of coronavirus disease 2019 (COVID-19). The short and long-term outcomes of patients who develop AKI have not been well characterized. METHODS: In this multicenter retrospective cohort study, we describe the clinical characteristics and outcomes of critically ill adults with severe COVID-19 and AKI. Patient-level variables were extracted from the electronic medical record. Using nadir-to-peak serum creatinine, AKI was defined using the KDIGO definition. Multivariable logistic regression analyses examined factors associated with development of moderate-to-severe (stage 2-3) AKI, severe (stage-3) AKI, and the composite of renal replacement therapy (RRT) or in-hospital death. RESULTS: Among 459 critically ill adults with COVID-19, 371 (80.1%) developed AKI, with 179 (37.9%) developing stage-3 AKI. Male gender, black and Asian/Native American race, lower baseline estimated glomerular filtration rate (eGFR), higher body mass index (BMI), and higher Acute Physiology and Chronic Health Evaluation (APACHE) IV score were more prevalent among patients with severe AKI, as were systemic markers of inflammation. On multivariable analysis, male gender, black and Asian/Native American race, higher APACHE IV score, lower baseline eGFR, and higher BMI (mainly the highest BMI stratum ≥35 kg/m2) were independently associated with higher stages of AKI severity. Male gender, lower baseline eGFR, and higher APACHE IV score were also independently associated with the composite of RRT or in-hospital death. Moderate-to-severe AKI and severe AKI were independently associated with in-hospital death, and there was a significant interaction between BMI and moderate-to-severe AKI for the outcome of in-hospital death. Among 83 (18.1%) patients who required RRT, 27 (32.5%) survived, and 12 (44.4%) remained dialysis-dependent at discharge. At 3 and 6 months, 5 (41.7%) and 4 (33.3%) remained dialysis-dependent, respectively. CONCLUSIONS: AKI is common in critically ill adults with COVID-19. Several patient-level risk factors are associated with higher stages of AKI severity. BMI might be an effect modifier of AKI severity for in-hospital death. Among AKI survivors, there is a high rate of short- and long-term dialysis dependence.

Rates of In-Hospital Decongestion and Association with Mortality and Cardiovascular Outcomes Among Patients Admitted for Acute Heart Failure.

BACKGROUND: Decongestion is an important goal in the management of acute heart failure. Whether the rate of decongestion is associated with mortality and cardiovascular outcomes is unknown. METHODS: Using data from 4133 patients from the Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study With Tolvaptan (EVEREST) trial, we used multivariable Cox regression models to evaluate the association between rates of in-hospital change in assessments of volume overload, including b-type natriuretic peptide (BNP), N-terminal pro b-type natriuretic peptide (NT-proBNP), as well as change in hemoconcentration, with risk of all-cause mortality and a composite outcome of cardiovascular mortality or heart failure hospitalization. RESULTS: More rapid rates of in-hospital decongestion were associated with decreased risk of mortality and the composite outcome over a median 10-month follow-up. In reference to the quartile of slowest decline, the quartile with the fastest BNP and NT-proBNP decline had lower hazards of mortality (hazard rate [HR] = 0.43 [0.31, 0.59] and HR = 0.27 [0.19, 0.40], respectively) and composite outcome (HR = 0.49 [0.39, 0.60] and HR = 0.54 [0.42, 0.71], respectively). In reference to the quartile of slowest increase, the quartile with the fastest hematocrit increase had lower hazards of mortality (HR = 0.77 [0.62, 0.95]) and composite outcome (HR = 0.75 [0.64, 0.88]). Results were also consistent when models were repeated using propensity-score matching. CONCLUSIONS: Faster rates of decongestion are associated with reduced risk of mortality and a composite of cardiovascular mortality and heart failure hospitalization. It remains unknown whether more rapid decongestion provides cardiovascular benefit or whether it serves as a proxy for less treatment resistant heart failure.