Heterogeneous Treatment Effects of Intensive Glycemic Control on Kidney Microvascular Outcomes and Mortality in ACCORD.

SIGNIFICANCE STATEMENT: Identifying and quantifying treatment effect variation across patients is the fundamental challenge of precision medicine. Here we quantify heterogeneous treatment effects of intensive glycemic control in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial, considering three outcomes of interest-a composite kidney outcome (driven by macroalbuminuria), all-cause mortality, and first assisted hypoglycemic event. We demonstrate that the effects of intensive glycemic control vary with risk of kidney failure, as predicted by the kidney failure risk equation (KFRE). Participants at highest risk of kidney failure gain the largest absolute kidney benefit of intensive glycemic control but also experience the largest absolute risk of death and hypoglycemic events. Our findings illustrate the value of identifying clinically meaningful treatment heterogeneity, particularly when treatments have different effects on multiple end points. OBJECTIVE: Clear criteria to individualize glycemic targets in patients with type II diabetes are lacking. In this post hoc analysis of the ACCORD, we evaluate whether the KFRE can identify patients for whom intensive glycemic control confers more benefit in preventing kidney microvascular outcomes. RESEARCH DESIGN AND METHODS: We divided the ACCORD trial population into quartiles on the basis of 5-year kidney failure risk using the KFRE. We estimated conditional treatment effects within each quartile and compared them with the average treatment effect in the trial. The treatment effects of interest were the 7-year restricted mean survival time (RMST) differences between intensive and standard glycemic control arms on ( 1 ) time-to-first development of severely elevated albuminuria or kidney failure and ( 2 ) all-cause mortality. RESULTS: We found evidence that the effect of intensive glycemic control on kidney microvascular outcomes and all-cause mortality varies with baseline risk of kidney failure. Patients with elevated baseline risk of kidney failure derived the most from intensive glycemic control in reducing kidney microvascular outcomes (7-year RMST difference of 114.8 [95% confidence interval 58.1 to 176.4] versus 48.4 [25.3 to 69.6] days in the entire trial population) However, this same patient group also experienced a shorter time to death (7-year RMST difference of -56.7 [-100.2 to -17.5] v. -23.6 [-42.2 to -6.6] days). CONCLUSIONS: We found evidence of heterogenous treatment effects of intensive glycemic control on kidney microvascular outcomes in ACCORD as a function of predicted baseline risk of kidney failure. Patients with higher kidney failure risk experienced the most pronounced reduction in kidney microvascular outcomes but also experienced the highest risk of all-cause mortality.

Defining systolic blood pressure normative values in hospitalized pediatric patients: a single center experience.

BACKGROUND: Normative blood pressure (BP) values and definition of hypertension (HTN) in children in outpatient setting cannot be reliably used for inpatient therapy initiation. No normative exists to describe HTN in hospitalized pediatric populations. We aimed to study the prevalence of hypertension and produce normative BP values in hospitalized children. METHODS: Cross sectional observational study of all children hospitalized on acute care floors, ≥2 and <18 years age, at Stanford Children's Hospital, from Jan-01-2014 to Dec-31-2018. Cohort included 7468 hospital encounters with a total of 118,423 automated, oscillometric, BPs measured in the upper extremity during a hospitalization of >24 hours. RESULTS: Overall prevalence of HTN, defined by outpatient guidelines, was 12-48% in boys and 6-39% in girls, stage 1 systolic HTN in 12-38% of boys and 6-31% of girls, stage 2 systolic HTN in 3-10% of boys and 1-8% of girls. Centile curves were derived demonstrating overall higher BP reading for hospitalized patients compared to the outpatient setting. CONCLUSION: Higher blood pressures are anticipated during hospitalization. Thresholds provided by the centile curves generated in this study may provide the clinician with some guidance on how to manage hospitalized pediatric patients based on clinical circumstances. IMPACT: Hospitalized children have higher blood pressures compared to patients in the ambulatory setting, hence outpatient normative blood pressure values cannot be reliably used for inpatient therapy initiation. No normative exists to describe hypertension in hospitalized pediatric populations. The thresholds provided by the centile curves generated in this study may provide the clinician with some guidance on how to manage hospitalized pediatric patients based on clinical circumstances.

Comparative effectiveness of sodium-glucose cotransporter-2 inhibitors versus glucagon-like peptide-1 receptor agonists in patients with type 2 diabetes and mild/moderate chronic kidney disease.

AIM: To determine the comparative effectiveness regarding major cardiovascular events of glucagon-like peptide-1 (GLP-1) receptor agonists and sodium-glucose cotransporter-2 (SGLT-2) inhibitors in patients with type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD). MATERIALS AND METHODS: We assembled a cohort of commercially insured adult patients with T2DM in the United States (derived from Optum Clinformatics DataMart 2003-2021) who were new users of GLP-1 receptor agonists or SGLT-2 inhibitors. We compared risks of non-fatal myocardial infarction or stroke in patients with and without CKD, and further categorized by CKD stage: stages G1 or G2 [estimated glomerular filtration rate (eGFR) ≥60 ml/min] and A2 (urine albumin to creatinine ratio 30 to <300 mg/g) or A3 (urine albumin to creatinine ratio ≥300 mg/g), stage G3a (eGFR 45 to <60 ml/min/1.73 m2 ) and stage G3b (eGFR 30 to <45 ml/min/1.73 m2 ). We used proportional hazards regression after inverse probability of treatment weighting to compute hazard ratios and 95% confidence intervals. RESULTS: After accounting for the probability of treatment, patients with T2DM and CKD treated with SGLT-2 inhibitors experienced a 14% lower risk of non-fatal myocardial infarction or stroke (hazard ratio 0.86, 95% confidence interval 0.78-0.94) relative to those treated with GLP-1 receptor agonists. CONCLUSIONS: Recognizing the potential for residual confounding, selection bias and immortal time bias, commercially insured patients in the United States with T2DM and CKD treated with SGLT-2 inhibitors experienced significantly lower risks of non-fatal myocardial infarction or stroke relative to those treated with GLP-1 receptor agonists.

Estimated Effect of Parathyroidectomy on Long-Term Kidney Function in Adults With Primary Hyperparathyroidism.

BACKGROUND: Multidisciplinary guidelines recommend parathyroidectomy to slow the progression of chronic kidney disease in patients with primary hyperparathyroidism (PHPT) and an estimated glomerular filtration rate (eGFR) less than 60 mL/min/1.73 m2. Limited data address the effect of parathyroidectomy on long-term kidney function. OBJECTIVE: To compare the incidence of a sustained decline in eGFR of at least 50% among patients with PHPT treated with parathyroidectomy versus nonoperative management. DESIGN: Target trial emulation was done using observational data from adults with PHPT, using an extended Cox model with time-varying inverse probability weighting. SETTING: Veterans Health Administration. PATIENTS: Patients with a new biochemical diagnosis of PHPT in 2000 to 2019. MEASUREMENTS: Sustained decline of at least 50% from pretreatment eGFR. RESULTS: Among 43 697 patients with PHPT (mean age, 66.8 years), 2928 (6.7%) had a decline of at least 50% in eGFR over a median follow-up of 4.9 years. The weighted cumulative incidence of eGFR decline was 5.1% at 5 years and 10.8% at 10 years in patients managed with parathyroidectomy, compared with 5.1% and 12.0%, respectively, in those managed nonoperatively. The adjusted hazard of eGFR decline did not differ between parathyroidectomy and nonoperative management (hazard ratio [HR], 0.98 [95% CI, 0.82 to 1.16]). Subgroup analyses found no heterogeneity of treatment effect based on pretreatment kidney function. Parathyroidectomy was associated with a reduced hazard of the primary outcome among patients younger than 60 years (HR, 0.75 [CI, 0.59 to 0.93]) that was not evident among those aged 60 years or older (HR, 1.08 [CI, 0.87 to 1.34]). LIMITATION: Analyses were done in a predominantly male cohort using observational data. CONCLUSION: Parathyroidectomy had no effect on long-term kidney function in older adults with PHPT. Potential benefits related to kidney function should not be the primary consideration for PHPT treatment decisions. PRIMARY FUNDING SOURCE: National Institute on Aging.

MyPlate Awareness and Engagement and Perceived and Objective Diet Quality in US Adults With Chronic Kidney Disease.

OBJECTIVE: Awareness of federal dietary guidelines has been associated with better perceived and objective diet quality. Little is known about the awareness of federal dietary recommendations among persons with chronic kidney disease (CKD) and the associations between recognition of guidelines, perception of diet quality, and objective quality of the diet in this population. DESIGN AND METHODS: We compared awareness of, and engagement with, MyPlate (a representation of 5 food groups from the US Department of Agriculture) along with perceived and objective diet quality, the latter assessed via Dietary Approaches to Stop Hypertension index scores, among US adults with and without CKD during 2017-2020. RESULTS: Among noninstitutionalized adults in the United States, 8.3% had albuminuria with normal or near-normal kidney function, 4.0% had estimated glomerular filtration rate 45-59 mL/minute/1.73 m2 (CKD stage G3a) and 1.6% had estimated glomerular filtration rate <45 mL/minute/1.73 m2 (CKD stages G3b/G4/G5). MyPlate awareness was lower among persons with CKD compared with those without CKD (19.6% vs. 26.4%, P < .001) and was lower among persons with more advanced CKD stages: 20.8%, 18.2%, and 16.3% in persons with CKD stages G1/G2, G3a, and G3b/G4/G5, respectively (trend P < .001). Among persons aware of MyPlate, a numerically higher proportion with CKD attempted to follow MyPlate recommendations (43.9% vs. 32.3%, P = .10); the proportion was highest among persons with moderate-to-advanced CKD (41.9%, 42.9%, and 56.9% among persons with CKD stages G1/G2, G3a, and G3b/G4/G5, respectively (trend P < .001)). Perceived and objective dietary quality (the latter based on concordance with the Dietary Approaches to Stop Hypertension diet) were slightly higher among persons with CKD relative to those without CKD. CONCLUSIONS: Adults with CKD have lower MyPlate awareness than adults without CKD. Enhancing diet education to persons with CKD could improve diet quality and potentially ameliorate CKD-associated complications.

Groundwater constituents and the incidence of kidney cancer.

BACKGROUND: Kidney cancer incidence demonstrates significant geographic variation suggesting a role for environmental risk factors. This study sought to evaluate associations between groundwater exposures and kidney cancer incidence. METHODS: The authors identified constituents from 18,506 public groundwater wells in all 58 California counties measured in 1996-2010, and obtained county-level kidney cancer incidence data from the California Cancer Registry for 2003-2017. The authors developed a water-wide association study (WWAS) platform using XWAS methodology. Three cohorts were created with 5 years of groundwater measurements and 5-year kidney cancer incidence data. The authors fit Poisson regression models in each cohort to estimate the association between county-level average constituent concentrations and kidney cancer, adjusting for known risk factors: sex, obesity, smoking prevalence, and socioeconomic status at the county level. RESULTS: Thirteen groundwater constituents met stringent WWAS criteria (a false discovery rate <0.10 in the first cohort, followed by p values <.05 in subsequent cohorts) and were associated with kidney cancer incidence. The seven constituents directly related to kidney cancer incidence (and corresponding standardized incidence ratios) were chlordane (1.06; 95% confidence interval [CI], 1.02-1.10), dieldrin (1.04; 95% CI, 1.01-1.07), 1,2-dichloropropane (1.04; 95% CI, 1.02-1.05), 2,4,5-TP (1.03; 95% CI, 1.01-1.05), glyphosate (1.02; 95% CI, 1.01-1.04), endothall (1.02; 95% CI, 1.01-1.03), and carbaryl (1.02; 95% CI, 1.01-1.03). Among the six constituents inversely related to kidney cancer incidence, the standardized incidence ratio furthest from the null was for bromide (0.97; 95% CI, 0.94-0.99). CONCLUSIONS: This study identified several groundwater constituents associated with kidney cancer. Public health efforts to reduce the burden of kidney cancer should consider groundwater constituents as environmental exposures that may be associated with the incidence of kidney cancer.

Parathyroidectomy and Cinacalcet Use in Medicare-Insured Kidney Transplant Recipients.

RATIONALE & OBJECTIVE: Posttransplant hyperparathyroidism is common, and treatment practices are poorly characterized. The goal of this study was to examine the incidence, associations, and outcomes of posttransplant parathyroidectomy and calcimimetic use in a cohort of Medicare-insured US kidney transplant recipients. STUDY DESIGN: Retrospective observational cohort study. SETTING & PARTICIPANTS: We used the US Renal Data System to extract demographic, clinical, and prescription data from Medicare Parts A, B, and D-insured patients who received their first kidney transplant in 2007-2013. We excluded patients with pretransplant parathyroidectomy. PREDICTORS: Calendar year of transplantation and pretransplant patient characteristics. OUTCOME: (1) Incidence of and secular trends in parathyroidectomy and cinacalcet use in the 3 years after transplant; (2) 90-day outcomes after posttransplant parathyroidectomy and cinacalcet initiation. ANALYTICAL APPROACH: Temporal trends and pretransplant correlates of parathyroidectomy and cinacalcet use were assessed using proportional hazards models and multivariable Poisson regression, respectively. RESULTS: The inclusion criteria were met by 30,127 patients, of whom 10,707 used cinacalcet before transplant, 551 underwent posttransplant parathyroidectomy, and 5,413 filled≥1 prescription for cinacalcet. The rate of posttransplant parathyroidectomy was stable over time. By contrast, cinacalcet use increased during the period studied. Long dialysis vintage and pretransplant cinacalcet use were strongly associated with posttransplant parathyroidectomy and cinacalcet use. Roughly 1 in 4 patients were hospitalized within 90 days of posttransplant parathyroidectomy, with hypocalcemia-related diagnoses being the most common complication. Parathyroidectomy (vs cinacalcet initiation) was not associated with an increase in acute kidney injury. LIMITATIONS: We lacked access to laboratory data to help assess the severity of secondary/tertiary hyperparathyroidism. The cohort was limited to Medicare beneficiaries. CONCLUSIONS: Almost one-fifth of our study cohort was treated with parathyroidectomy and/or cinacalcet. Further studies are needed to establish the optimal treatment for posttransplant hyperparathyroidism.

An Overview of Current Methods for Real-world Applications to Generalize or Transport Clinical Trial Findings to Target Populations of Interest.

It has been well established that randomized clinical trials have poor external validity, resulting in findings that may not apply to relevant-or target-populations. When the trial is sampled from the target population, generalizability methods have been proposed to address the applicability of trial findings to target populations. When the trial sample and target populations are distinct, transportability methods may be applied for this purpose. However, generalizability and transportability studies present challenges, particularly around the strength of their conclusions. We review and summarize state-of-the-art methods for translating trial findings to target populations. We additionally provide a novel step-by-step guide to address these challenges, illustrating principles through a published case study. When conducted with rigor, generalizability and transportability studies can play an integral role in regulatory decisions by providing key real-world evidence.

Age-related decline in anti-HBV antibodies in vaccinated kidney transplant recipients.

BACKGROUND: Hepatitis B virus (HBV) vaccination is indicated for all end stage kidney disease patients, including all solid organ transplant candidates. Maintenance of adequate immunity is especially important for immunosuppressed solid organ recipients who are at increased risk for donor or community acquired HBV. The impact of age and immunosuppression on long-term maintenance of HBV immunity postvaccination has not been fully investigated. METHODS: We performed a single-center retrospective study of 96 kidney transplant recipients, transplanted between July 2012 and December 2020, who had Hepatitis B surface antibody (HBsAb) levels measured pretransplantation and 1-year posttransplantation. We compared the change in HBsAb levels stratified by patient's age (<45, 45-60, and >60) and by whether or not the patient received lymphocyte depleting induction therapy. RESULTS: Our results demonstrate that HBsAb IgG levels vary by age group, decreased significantly at 1-year posttransplant (p < .0001) and were significantly lower in the older cohort (p = .03). Among recipients who received rabbit anti-thymocyte globulin induction (rATG), the log HbsAb levels were significantly lower in the older age group (2.15 in age <45, 1.75 in age 45-60 and 1.47 in age >60, p = .01). Age group (p = .004), recipient HBcAb status (p = .002), and rATG (p = .048) were independently associated with >20% reduction in log HBsAb levels posttransplant. CONCLUSION: Significant declines in HBsAb levels occur postkidney transplantation, especially in older individuals, thus placing exposed older kidney transplant recipients at greater risk of HBV infection and associated complications.

Functional Consequences of Memory Inflation after Solid Organ Transplantation.

CMV is a major infectious complication following solid organ transplantation. Reactivation of CMV leads to memory inflation, a process in which CD8 T cells expand over time. Memory inflation is associated with specific changes in T cell function, including increased oligoclonality, decreased cytokine production, and terminal differentiation. To address whether memory inflation during the first year after transplantation in human subjects alters T cell differentiation and function, we employed single-cell-matched TCRαß and targeted gene expression sequencing. Expanded T cell clones exhibited a terminally differentiated, immunosenescent, and polyfunctional phenotype whereas rare clones were less differentiated. Clonal expansion occurring between pre- and 3 mo posttransplant was accompanied by enhancement of polyfunctionality. In contrast, polyfunctionality and differentiation state were largely maintained between 3 and 12 mo posttransplant. Highly expanded clones had a higher degree of polyfunctionality than rare clones. Thus, CMV-responsive CD8 T cells differentiated during the pre- to posttransplant period then maintained their differentiation state and functional capacity despite posttransplant clonal expansion.

Evolution of Cytomegalovirus-Responsive T Cell Clonality following Solid Organ Transplantation.

CMV infection is a significant complication after solid organ transplantation. We used single cell TCR αß sequencing to determine how memory inflation impacts clonality and diversity of the CMV-responsive CD8 and CD4 T cell repertoire in the first year after transplantation in human subjects. We observed CD8 T cell inflation but no changes in clonal diversity, indicating homeostatic stability in clones. In contrast, the CD4 repertoire was diverse and stable over time, with no evidence of CMV-responsive CD4 T cell expansion. We identified shared CDR3 TCR motifs among patients but no public CMV-specific TCRs. Temporal changes in clonality in response to transplantation and in the absence of detectable viral reactivation suggest changes in the repertoire immediately after transplantation followed by an expansion with stable clonal competition that may mediate protection.

SARS-CoV-2 Vaccine Antibody Response and Breakthrough Infection in Patients Receiving Dialysis.

BACKGROUND: Whether breakthrough SARS-CoV-2 infections after vaccination are related to the level of postvaccine circulating antibody is unclear. OBJECTIVE: To determine longitudinal antibody-based response and risk for breakthrough infection after SARS-CoV-2 vaccination. DESIGN: Prospective study. SETTING: Nationwide sample from dialysis facilities. PATIENTS: 4791 patients receiving dialysis. MEASUREMENTS: Remainder plasma from a laboratory processing routine monthly tests was used to measure qualitative and semiquantitative antibodies to the receptor-binding domain (RBD) of SARS-CoV-2. To evaluate whether peak or prebreakthrough RBD values were associated with breakthrough infection, a nested case-control analysis matched each breakthrough case patient to 5 control patients by age, sex, and vaccination month and adjusted for diabetes status and region of residence. RESULTS: Of the 4791 patients followed with monthly RBD assays, 2563 were vaccinated as of 14 September 2021. Among the vaccinated patients, the estimated proportion with an undetectable RBD response increased from 6.6% (95% CI, 5.5% to 7.8%) 14 to 30 days after vaccination to 20.2% (CI, 17.0% to 23.3%) 5 to 6 months after vaccination. Estimated median index values decreased from 91.9 (CI, 78.6 to 105.2) 14 to 30 days after vaccination to 8.4 (CI, 7.6 to 9.3) 5 to 6 months after vaccination. Breakthrough infections occurred in 56 patients, with samples collected a median of 21 days before breakthrough infection. Compared with prebreakthrough index RBD values of 23 or higher (equivalent to ≥506 binding antibody units per milliliter), prebreakthrough RBD values less than 10 and values from 10 to less than 23 were associated with higher odds for breakthrough infection (rate ratios, 11.6 [CI, 3.4 to 39.5] and 6.0 [CI, 1.5 to 23.6], respectively). LIMITATIONS: Single measure of vaccine response; ascertainment of COVID-19 diagnosis from electronic health records. CONCLUSION: The antibody response to SARS-CoV-2 vaccination wanes rapidly in persons receiving dialysis. In this population, the circulating antibody response is associated with risk for breakthrough infection. PRIMARY FUNDING SOURCE: Ascend Clinical Laboratory.

SARS-CoV-2 Infection during the Omicron Surge among Patients Receiving Dialysis: The Role of Circulating Receptor-Binding Domain Antibodies and Vaccine Doses.

BACKGROUND: It is unclear whether circulating antibody levels conferred protection against SARS-CoV-2 infection among patients receiving dialysis during the Omicron-dominant period. METHODS: We followed monthly semiquantitative SARS-CoV-2 RBD IgG index values in a randomly selected nationwide cohort of patients receiving dialysis and ascertained SARS-CoV-2 infection during the Omicron-dominant period of December 25, 2021 to January 31, 2022 using electronic health records. We estimated the relative risk for documented SARS-CoV-2 infection by vaccination status and by circulating RBD IgG using a log-binomial model accounting for age, sex, and prior COVID-19. RESULTS: Among 3576 patients receiving dialysis, 901 (25%) received a third mRNA vaccine dose as of December 24, 2021. Early antibody responses to third doses were robust (median peak index IgG value at assay limit of 150). During the Omicron-dominant period, SARS-CoV-2 infection was documented in 340 (7%) patients. Risk for infection was higher among patients without vaccination and with one to two doses (RR, 2.1; 95% CI, 1.6 to 2.8, and RR, 1.3; 95% CI, 1.0 to 1.8 versus three doses, respectively). Irrespective of the number of vaccine doses, risk for infection was higher among patients with circulating RBD IgG <23 (506 BAU/ml) (RR range, 2.1 to 3.2, 95% CI, 1.3 to 3.4 and 95% CI, 2.2 to 4.5, respectively) compared with RBD IgG ≥23. CONCLUSIONS: Among patients receiving dialysis, a third mRNA vaccine dose enhanced protection against SARS-CoV-2 infection during the Omicron-dominant period, but a low circulating RBD antibody response was associated with risk for infection independent of the number of vaccine doses. Measuring circulating antibody levels in this high-risk group could inform optimal timing of vaccination and other measures to reduce risk of SARS-CoV-2 infection.

Post-Vaccination Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infections and Incidence of the Presumptive B.1.427/B.1.429 Variant Among Healthcare Personnel at a Northern California Academic Medical Center.

BACKGROUND: Although mRNA-based severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines report >90% efficacy, breakthrough infections occur. Little is known about their effectiveness against SARS-CoV-2 variants, including the highly prevalent B.1.427/B.1.429 variant. METHODS: In this quality improvement project, we collected demographic and clinical information from post-vaccine SARS-CoV-2 cases (PVSCs), defined as healthcare personnel (HCP) with positive SARS-CoV-2 nucleic acid amplification test after receiving ≥1 vaccine dose. Available specimens were tested for L452R, N501Y, and E484K mutations using reverse-transcription polymerase chain reaction. Mutation prevalence was compared among unvaccinated, early post-vaccinated (≤14 days after dose 1), partially vaccinated (positive test >14 days after dose 1 and <14 days after dose 2), and fully vaccinated (>14 days after dose 2) PVSCs. RESULTS: From December 2020 to April 2021, ≥23 090 HCP received ≥1 dose of an mRNA-based SARS-CoV-2 vaccine, and 660 HCP cases of SARS-CoV-2 occurred, of which 189 were PVSCs. Among the PVSCs, 114 (60.3%), 49 (25.9%), and 26 (13.8%) were early post-vaccination, partially vaccinated, and fully vaccinated, respectively. Of 261 available samples from vaccinated and unvaccinated HCP, 103 (39.5%), including 42 PVSCs (36.5%), had the L452R mutation presumptive of B.1.427/B.1.429. When adjusted for community prevalence of B.1.427/B.1.429, PVSCs did not have significantly elevated risk of B.1.427/B.1.429 compared with unvaccinated HCP. CONCLUSIONS: Most PVSCs occurred prior to expected onset of full, vaccine-derived immunity. Presumptive B.1.427/B.1.429 was not more prevalent in post-vaccine cases than in unvaccinated SARS-CoV-2 HCP. Continued infection control measures, particularly <14 days post-vaccination, and continued variant surveillance in PVSCs are imperative to control future SARS-CoV-2 surges.

Nephrology Referral Based on Laboratory Values, Kidney Failure Risk, or Both: A Study Using Veterans Affairs Health System Data.

RATIONALE & OBJECTIVE: Current guidelines for nephrology referral are based on laboratory criteria. We sought to evaluate whether nephrology referral patterns reflect current clinical practice guidelines and to estimate the change in referral volume if they were based on the estimated risk of kidney failure. STUDY DESIGN: Observational cohort. SETTING & PARTICIPANTS: Retrospective study of 399,644 veterans with chronic kidney disease (October 1, 2015 through September 30, 2016). EXPOSURE: Laboratory referral criteria based on Veterans Affairs/Department of Defense guidelines, categories of predicted risk for kidney failure using the Kidney Failure Risk Equation, and the combination of laboratory referral criteria and predicted risk. OUTCOME: Number of patients identified for referral. ANALYTICAL APPROACH: We evaluated the number of patients who were referred and their predicted 2-year risk for kidney failure. For each exposure, we estimated the number of patients who would be identified for referral. RESULTS: There were 66,276 patients who met laboratory indications for referral. Among these patients, 11,752 (17.7%) were referred to nephrology in the following year. The median 2-year predicted risk of kidney failure was 1.5% (interquartile range, 0.3%-4.7%) among all patients meeting the laboratory referral criteria. If referrals were restricted to patients with a predicted risk of ≥1% in addition to laboratory indications, the potential referral volume would be reduced from 66,276 to 38,229 patients. If referrals were based on predicted risk alone, a 2-year risk threshold of 1% or higher would identify a similar number of patients (72,948) as laboratory-based criteria with median predicted risk of 2.3% (interquartile range, 1.4%-4.6%). LIMITATIONS: Missing proteinuria measurements. CONCLUSIONS: The current laboratory-based guidelines for nephrology referral identify patients who are, on average, at low risk for progression, most of whom are not referred. As an alternative, referral based on a 2-year kidney failure risk exceeding 1% would identify a similar number of patients but with a higher median risk of kidney failure.

Cardiovascular outcomes associated with prescription of sodium-glucose co-transporter-2 inhibitors versus dipeptidyl peptidase-4 inhibitors in patients with diabetes and chronic kidney disease.

AIM: To determine the association with cardiovascular (CV) outcomes of sodium-glucose co-transporter-2 (SGLT-2) inhibitors compared with dipeptidyl peptidase-4 (DPP-4) inhibitors in patients with type 2 diabetes (T2D) and chronic kidney disease (CKD). MATERIALS AND METHODS: We conducted a population-based cohort study of new users of SGLT-2 inhibitors and DPP-4 inhibitors with T2D and CKD using data from Optum Clinformatics DataMart. We assembled three cohorts: T2D/no CKD, T2D/CKD 1-2, and T2D/CKD 3a. The study outcomes were (a) time to first heart failure (HF) hospitalization and (b) time to a composite CV endpoint comprised of non-fatal myocardial infarction (MI) or stroke. After inverse probability of treatment weighting, we used proportional hazards regression to estimate hazard ratios (HR) and 95% confidence intervals (CI). RESULTS: New users of SGLT-2 inhibitors versus DPP-4 inhibitors had lower risks of HF hospitalization in the T2D/no CKD (HR, 0.76; 95% CI, 0.70, 0.82) and T2D/CKD 1-2 (HR, 0.63; 95% CI, 0.48, 0.84) cohorts, but no significant association was present in the T2D/CKD 3a cohort. Compared with prescription of DPP-4 inhibitors, SGLT-2 inhibitors were associated with lower risks of non-fatal MI or stroke of 23% (HR, 0.77; 95% CI, 0.70, 0.85) in the T2D/no CKD cohort, but no significant associations were present in the T2D/CKD 1-2 and T2D/CKD 3a cohorts. CONCLUSIONS: Incident prescription of SGLT-2 inhibitors was associated with lower risks of HF hospitalization but not with non-fatal MI or stroke despite suggesting benefit, relative to prescription of DPP-4 inhibitor across different stages of CKD.

Serial SARS-CoV-2 Receptor-Binding Domain Antibody Responses in Patients Receiving Dialysis.

BACKGROUND: Assessing the evolution of SARS-CoV-2 immune response among patients receiving dialysis can define its durability in a highly clinically relevant context because patients receiving dialysis share the characteristics of persons most susceptible to SARS-CoV-2 infection. OBJECTIVE: To evaluate the persistence of SARS-CoV-2 receptor-binding domain (RBD) IgG in seroprevalent patients receiving dialysis. DESIGN: Prospective. SETTING: Nationwide sample from dialysis facilities. PATIENTS: 2215 patients receiving dialysis who had evidence of SARS-CoV-2 infection as of July 2020. MEASUREMENTS: Remainder plasma from routine monthly laboratories was used to measure semiquantitative RBD IgG index value over 6 months. RESULTS: A total of 2063 (93%) seroprevalent patients reached an assay detectable response (IgG index value ≥1). Most (n = 1323, 60%) had responses in July with index values classified as high (IgG ≥10); 1003 (76%) remained within this stratum. Adjusted median index values declined slowly but continuously (July vs. December values were 21 vs. 13; P < 0.001). The trajectory of the response did not vary by age group, sex, race/ethnicity, or diabetes status. Patients without an assay detectable response (n = 137) were more likely to be White and in the younger (18 to 44 years) or older (≥80 years) age groups and less likely to have diabetes and hypoalbuminemia. LIMITATION: Lack of data on symptoms or reverse transcriptase polymerase chain reaction diagnosis, cohort of persons who survived infection, and use of a semiquantitative assay. CONCLUSION: Despite impaired immunity, most seropositive patients receiving dialysis maintained RBD antibody levels over 6 months. A slow and continual decline in median antibody levels over time was seen, but no indication that subgroups with impaired immunity had a shorter-lived humoral response was found. PRIMARY FUNDING SOURCE: Ascend Clinical Laboratories.

National Estimates of CKD Prevalence and Potential Impact of Estimating Glomerular Filtration Rate Without Race.

BACKGROUND: The implications of removing the adjustment for Black race in equations to eGFR on the prevalence of CKD and management strategies are incompletely understood. METHODS: We estimated changes in CKD prevalence and the potential effect on therapeutic drug prescriptions and prediction of kidney failure if race adjustment were removed from the CKD-EPI GFR estimating equation. We used cross-sectional and longitudinal data from adults aged ≥18 years in the National Health and Nutrition Examination Survey (NHANES) from 2015 to 2016, and the Veterans Affairs (VA) Health Care System in 2015. In the VA cohort, we assessed use of common medications that require dose adjustment on the basis of kidney function, and compared the prognostic accuracy of the Kidney Failure Risk Equation with versus without race adjustment of eGFR. RESULTS: The prevalence of CKD among Black adults increased from 5.2% to 10.6% in NHANES, and from 12.4% to 21.6% in the VA cohort after eliminating race adjustment. Among Black veterans, 41.0% of gabapentin users, 33.5% of ciprofloxacin users, 24.0% of metformin users, 6.9% of atenolol users, 6.6% of rosuvastatin users, and 5.8% of tramadol users were reclassified to a lower eGFR for which dose adjustment or discontinuation is recommended. Without race adjustment of eGFR, discrimination of the Kidney Failure Risk Equation among Black adults remained high and calibration was marginally improved overall, with better calibration at higher levels of predicted risk. CONCLUSIONS: Removal of race adjustment from CKD-EPI eGFR would double the estimated prevalence of CKD among Black adults in the United States. Such a change is likely to affect a sizeable number of drug-dosing decisions. It may also improve the accuracy of kidney failure risk prediction among higher-risk Black adults.

SARS-CoV-2 Vaccine Acceptability in Patients on Hemodialysis: A Nationwide Survey.

BACKGROUND: Patients on dialysis are at increased risk for COVID-19-related complications. However, a substantial fraction of patients on dialysis belong to groups more likely to be hesitant about vaccination. METHODS: With the goal of identifying strategies to increase COVID-19 vaccine uptake among patients on hemodialysis, we conducted a nationwide vaccine acceptability survey, partnering with a dialysis network to distribute an anonymized English and Spanish language online survey in 150 randomly selected facilities in the United States. We used logistic regression to evaluate characteristics of vaccine-hesitant persons. RESULTS: A total of 1515 (14% of eligible) patients responded; 20% of all responders, 29% of patients aged 18-44 years, and 29% of Black responders reported being hesitant to seek the COVID-19 vaccine, even if the vaccine was considered safe for the general population. Odds of vaccine hesitancy were higher among patients aged 18-44 years versus those 45-64 years (odds ratio [OR], 1.5; 95% confidence interval [95% CI], 1.0 to 2.3), Black patients versus non-Hispanic White patients (OR, 1.9; 95% CI, 1.3 to 2.7), Native Americans or Pacific Islanders versus non-Hispanic White patients (OR, 2.0; 95% CI, 1.1 to 3.7), and women versus men (OR, 1.6; 95% CI, 1.2 to 2.0). About half (53%) of patients who were vaccine hesitant expressed concerns about side effects. Responders' main information sources about COVID-19 vaccines were television news and dialysis staff (68% and 38%, respectively). CONCLUSIONS: A substantial proportion of patients receiving in-center hemodialysis in the United States are hesitant about seeking COVID-19 vaccination. Facilitating uptake requires outreach to younger patients, women, and Black, Native American, or Pacific Islander patients, and addressing concerns about side effects. PODCAST: This article contains a podcast at https://www.asn-online.org/media/podcast/JASN/2021_07_07_JASN2021010104.mp3.

Comparison Between Ticagrelor and Clopidogrel in Elderly Patients With an Acute Coronary Syndrome: Insights From the SWEDEHEART Registry.

BACKGROUND: The comparative efficacy and safety of ticagrelor versus clopidogrel in older patients with myocardial infarction (MI) has received limited study. METHODS: We performed an observational analysis of all patients ≥80 years (n=14 005) who were discharged alive with aspirin combined with either clopidogrel (60.2%) or ticagrelor (39.8%) after a MI between 2010 and 2017 registered in the national registry SWEDEHEART (Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies). Inverse probability treatment weighting was used in Cox regression models to adjust for differences in demographics, in-hospital therapies, and medications. The primary ischemic outcome (death, MI, or stroke), and bleeding were obtained from national registries at 1 year. A sensitivity analysis in <80-year-old patients was performed. RESULTS: In patients ≥80 years, the incidence of the primary ischemic outcome (hazard ratio [HR], 0.97 [95% CI, 0.88-1.06]) was similar for ticagrelor- and clopidogrel-treated patients. Ticagrelor was associated with a 17% and 48% higher risk of death (HR, 1.17 [95% CI, 1.03-1.32]) and bleeding (HR, 1.48 [95% CI, 1.25-1.76]), but a lower risk of MI (HR, 0.80 [95% CI, 0.70-0.92]) and stroke (HR, 0.72 [95% CI, 0.56-0.93]). In <80-year-old patients, the incidence of the primary ischemic outcome was 17% (HR, 0.83 [95% CI, 0.77-0.89]) lower with ticagrelor. Ticagrelor was associated with 15% (HR, 0.85 [95% CI, 0.76-0.96]) lower risk of death, 32% higher risk of bleeding (HR, 1.32 [95% CI, 1.18-1.47]), but lower risk of MI (HR, 0.82 [95% CI, 0.75-0.91]) and stroke (HR, 0.82 [95% CI, 0.69-0.98]). CONCLUSIONS: Ticagrelor use among elderly patients with MI was associated with higher risk of bleeding and death compared with clopidogrel. A randomized study of ticagrelor versus clopidogrel in the elderly is needed.