Finerenone in Black Patients With Type 2 Diabetes and CKD: A Post hoc Analysis of the Pooled FIDELIO-DKD and FIGARO-DKD Trials.

Rationale & Objective: In FIDELITY, finerenone improved cardiorenal outcomes in patients with chronic kidney disease (CKD) and type 2 diabetes (T2D). This analysis explored the efficacy and safety of finerenone in Black patients. Study Design: Subanalysis of randomized controlled trials. Setting & Participants: Patients with T2D and CKD. Intervention: Finerenone or placebo. Outcomes: Composite of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure; composite of kidney failure, sustained ≥57% estimated glomerular filtration rate (eGFR) decline from baseline maintained for ≥4 weeks, or renal death. Results: Of the 13,026 patients, 522 (4.0%) self-identified as Black. Finerenone demonstrated similar effects on the cardiovascular composite outcome in Black (HR, 0.79 [95% CI, 0.51-1.24]) and non-Black patients (HR, 0.87 [95% CI, 0.79-0.96; P = 0.5 for interaction]). Kidney composite outcomes were consistent in Black (HR, 0.71 [95% CI, 0.43-1.16]) and non-Black patients (HR, 0.76 [95% CI, 0.66-0.88; P = 0.9 for interaction]). Finerenone reduced urine albumin-to-creatinine ratio by 40% at month 4 (least-squares mean treatment ratio, 0.60 [95% CI, 0.52-0.69; P < 0.001]) in Black patients and 32% at month 4 (least-squares mean treatment ratio, 0.68 [95% CI, 0.66-0.70; P < 0.001]) in non-Black patients, versus placebo. Chronic eGFR decline (month 4 to end-of-study) was slowed in Black and non-Black patients treated with finerenone versus placebo (between-group difference, 1.4 mL/min/1.73 m2 per year [95% CI, 0.33-2.44; P = 0.01] and 1.1 mL/min/1.73 m2 per year [95% CI, 0.89-1.28; P < 0.001], respectively). Safety outcomes were similar between subgroups. Limitations: Small number of Black patients; analysis was not originally powered to determine an interaction effect based on Black race. Conclusions: The efficacy and safety of finerenone appears consistent in Black and non-Black patients with CKD and T2D. Funding: Bayer AG. Trial Registration: ClinicalTrials.gov NCT02540993, NCT02545049. Plain-Language Summary: Diabetes is a major cause of chronic kidney disease (CKD), affecting more Black adults than White adults. Most adults with CKD ultimately die from heart and vascular complications (eg, heart attack and stroke) rather than kidney failure. This analysis of 2 recent trials shows that the drug finerenone was beneficial for patients with diabetes and CKD. Along with reducing kidney function decline and protein in the urine, it also decreased heart and vascular issues and lowered blood pressure in both Black and non-Black adults with diabetes and CKD. These findings have promising implications for slowing the progression of CKD and protecting against cardiovascular problems in diverse populations.

Mineralocorticoid receptor antagonism in diabetes reduces albuminuria by preserving the glomerular endothelial glycocalyx.

The glomerular endothelial glycocalyx (GEnGlx) forms the first part of the glomerular filtration barrier. Previously, we showed that mineralocorticoid receptor (MR) activation caused GEnGlx damage and albuminuria. In this study, we investigated whether MR antagonism could limit albuminuria in diabetes and studied the site of action. Streptozotocin-induced diabetic Wistar rats developed albuminuria, increased glomerular albumin permeability (Ps'alb), and increased glomerular matrix metalloproteinase (MMP) activity with corresponding GEnGlx loss. MR antagonism prevented albuminuria progression, restored Ps'alb, preserved GEnGlx, and reduced MMP activity. Enzymatic degradation of the GEnGlx negated the benefits of MR antagonism, confirming their dependence on GEnGlx integrity. Exposing human glomerular endothelial cells (GEnC) to diabetic conditions in vitro increased MMPs and caused glycocalyx damage. Amelioration of these effects confirmed a direct effect of MR antagonism on GEnC. To confirm relevance to human disease, we used a potentially novel confocal imaging method to show loss of GEnGlx in renal biopsy specimens from patients with diabetic nephropathy (DN). In addition, patients with DN randomized to receive an MR antagonist had reduced urinary MMP2 activity and albuminuria compared with placebo and baseline levels. Taken together, our work suggests that MR antagonists reduce MMP activity and thereby preserve GEnGlx, resulting in reduced glomerular permeability and albuminuria in diabetes.

Retrieval of renal function after renal artery stenting improves event-free survival in a subgroup analysis of the Cardiovascular Outcomes in Renal Atherosclerotic Lesions trial.

OBJECTIVE: The Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL) trial, a multicenter randomized controlled trial with 947 patients, concluded that there was no benefit of renal artery stenting (RAS) over medical therapy. However, patients with chronic kidney disease (CKD) were not analyzed separately in the CORAL trial. CKD is a risk factor for cardiovascular and renal morbidity. We hypothesized that improved renal function after RAS would be associated with increased long-term survival and a lower risk of cardiovascular and renal events in patients with CKD. METHODS: This post hoc analysis of the CORAL trial included 842 patients with CKD stages 2 to 4 at baseline who were randomized to optimal medical therapy alone (OMT; n = 432) or RAS plus OMT (RAS + OMT; n = 410). Patients were categorized as responders or nonresponders based on the change in the estimated glomerular filtration rate (eGFR) from baseline to last follow-up (median, 3.6 years; interquartile range, 2.6-4.6 years). Responders were defined by a 20% or greater increase in eGFR from baseline; all others were designated as nonresponders. Event-free survival was defined as freedom from death and multiple cardiovascular and renal complications. Event-free survival was analyzed using the Kaplan-Meier method and log-rank test. Multivariable Cox proportional hazards regression analysis was used to identify independent predictors of event-free survival. RESULTS: The RAS + OMT group had a higher proportion of patients with improved renal function (≥20% increase in eGFR over baseline), compared with the OMT group (25.6% vs 17.1%; P = .003). However, event-free survival was no different for the two cohorts (P = .18 by the log-rank test). Multivariable Cox proportional hazards regression analysis identified four variables that independently correlated with event-free survival for the stented cohort. Higher preoperative eGFR (hazard ratio, 0.98; 95% confidence interval [CI], 0.96-0.99; P = .002) and being a responder to stenting (hazard ratio, 0.49; 95% CI, 0.26-0.95; P = .033) increased event-free survival, whereas a history of congestive heart failure (hazard ratio, 2.52; 95% CI, 1.46-4.35; P < .001) and a higher preoperative systolic BP (hazard ratio, 1.02; 95% CI, 1.01-1.03; P = .002) decreased event-free survival. Within the stented group, 105 of 410 patients (25.6%) were responders. Event-free survival was superior for responders, compared with nonresponders (P = .009 by log-rank test). The only independent preoperative negative predictor of improved renal function after stenting was diabetes (odds ratio, 0.37; 95% CI, 0.16-0.84; P = .017), which decreased the probability of improved renal function after RAS + OMT. A subset of patients (23.4%) after RAS had worsened renal function, but OMT alone produced an equivalent incidence of worsened renal function. An increased urine albumin/creatinine ratio was an independent predictor of worsened renal function after RAS. CONCLUSIONS: CORAL participants who demonstrated improved kidney function after RAS + OMT demonstrated improved event-free survival. This finding reinforces the need for predictors of outcome to guide patient selection for RAS.

Effects of Dapagliflozin on Hospitalizations in Patients With Chronic Kidney Disease : A Post Hoc Analysis of DAPA-CKD.

BACKGROUND: Acute hospitalizations are common in patients with chronic kidney disease (CKD) and often lead to decreases in health-related quality of life and increased care costs. OBJECTIVE: To determine the effects of dapagliflozin on first hospitalizations and all (first and subsequent) hospitalizations and to explore effects on cause-specific hospitalizations. DESIGN: Post hoc analysis of a randomized, double-blind, placebo-controlled clinical trial. (ClinicalTrials.gov: NCT03036150). SETTING: 386 ambulatory practice sites in 21 countries from 2 February 2017 through 12 June 2020. PARTICIPANTS: Adults with an estimated glomerular filtration rate of 25 to 75 mL/min/1.73 m2 and a urinary albumin-creatinine ratio of 200 to 5000 mg/g, with and without type 2 diabetes. INTERVENTION: Dapagliflozin, 10 mg once daily, or matching placebo (1:1 ratio). MEASUREMENTS: The effects of dapagliflozin on first hospitalizations for any cause, all hospitalizations, and cause-specific (first and recurrent) hospitalizations were determined. The reported system organ class was used to evaluate reasons for admission. Hospitalizations were analyzed using Cox proportional hazards regression models (first hospitalization), the Lin-Wei-Yang-Ying method (all hospitalizations or death), and negative binomial models (cause-specific hospitalizations). RESULTS: The study included 4304 patients (mean age, 61.8 years; 33.1% women). During a median follow-up of 2.4 years, 2072 hospitalizations were reported among 1224 (28.4%) participants. Compared with placebo, dapagliflozin reduced risk for a first hospitalization (hazard ratio, 0.84 [95% CI, 0.75 to 0.94]) and all hospitalizations or death (rate ratio, 0.79 [CI, 0.70 to 0.89]). There was no evidence that the effects of dapagliflozin on first and all hospitalizations varied by baseline presence of type 2 diabetes (P for interaction = 0.60 for each). Compared with placebo, dapagliflozin reduced the rate of admissions due to cardiac disorders, renal and urinary disorders, metabolism and nutrition disorders, and neoplasms. LIMITATIONS: This was a post hoc analysis and should be viewed as hypothesis-generating. Hospitalizations and causes were reported by site investigators and were not centrally adjudicated. CONCLUSION: Dapagliflozin reduced the risk for hospitalization for any cause in patients with CKD with and without type 2 diabetes. PRIMARY FUNDING SOURCE: AstraZeneca.

Safety and efficacy of dapagliflozin in patients with focal segmental glomerulosclerosis: a prespecified analysis of the dapagliflozin and prevention of adverse outcomes in chronic kidney disease (DAPA-CKD) trial.

BACKGROUND: Despite renin-angiotensin-aldosterone system blockade and immunosuppressive treatment, focal segmental glomerulosclerosis (FSGS) often progresses to kidney failure. The objective of this prespecified analysis of the dapagliflozin and prevention of adverse outcomes in chronic kidney disease trial (DAPA-CKD) was to assess efficacy and safety of dapagliflozin in a small subgroup of participants with FSGS confirmed by kidney biopsy. METHODS: In DAPA-CKD, patients with an estimated glomerular filtration rate (eGFR) 25-75 mL/min/1.73 m2 and urinary albumin:creatinine ratio (UACR) 200-5000 mg/g (22.6-565 mg/mol) were randomized to dapagliflozin 10 mg once daily or placebo as an adjunct to standard care and followed for median 2.4 years. The primary composite endpoint was sustained eGFR decline ≥50%, end-stage kidney disease, or kidney or cardiovascular death. The endpoint of interest for this analysis was eGFR slope (acute effects from baseline to Week 2 and chronic effects from Week 2 to end of treatment). RESULTS: Of 104 participants with biopsy-confirmed FSGS, 45 were randomized to dapagliflozin and 59 to placebo. Mean (standard deviation) age was 54.0 (14.3) years, mean eGFR 41.9 (11.5) mL/min/1.73 m2 and median (interquartile range) UACR 1248 (749-2211) mg/g. The primary outcome occurred in 4 (8.9%) and 7 (11.9%) participants randomized to dapagliflozin and placebo, respectively [hazard ratio 0.62, 95% confidence interval (95% CI) 0.17, 2.17]. Dapagliflozin led to a larger acute reduction (standard error) in eGFR compared with placebo (-4.5, 95% CI -5.9 to -3.1 versus -0.9, -2.1 to 0.4 mL/min/1.73 m2/2 weeks). Thereafter, mean rates of chronic eGFR decline with dapagliflozin and placebo were -1.9 (-3.0, -0.9) and -4.0 (-4.9, -3.0) mL/min/1.73 m2/year, respectively (difference 2.0, 95% CI 0.6 to 3.5, mL/min/1.73 m2/year). Adverse events leading to study drug discontinuation were similar in both groups; there were fewer serious adverse events with dapagliflozin. CONCLUSIONS: Among DAPA-CKD participants with FSGS, dapagliflozin reduced the rate of chronic decline of eGFR compared with placebo, although this difference was not statistically significant.

Effects of canagliflozin versus finerenone on cardiorenal outcomes: exploratory post hoc analyses from FIDELIO-DKD compared to reported CREDENCE results.

BACKGROUND: The nonsteroidal mineralocorticoid receptor antagonist finerenone and the sodium-glucose cotransporter-2 inhibitor (SGLT-2i) canagliflozin reduce cardiorenal risk in albuminuric patients with chronic kidney disease (CKD) and type 2 diabetes (T2D). At first glance, the results of Finerenone in Reducing Kidney Failure and Disease Progression in Diabetic Kidney Disease (FIDELIO-DKD) (ClinicalTrials.gov, NCT02540993) and Canagliflozin and Renal Events in Diabetes with Established Nephropathy Clinical Evaluation (CREDENCE) appear disparate. In FIDELIO-DKD, the primary endpoint had an 18% [95% confidence interval (CI) 7-27] relative risk reduction; in CREDENCE, the primary endpoint had a 30% (95% CI 18-41) relative risk reduction. Unlike CREDENCE, the FIDELIO-DKD trial included patients with high albuminuria but excluded patients with symptomatic heart failure with reduced ejection fraction. The primary endpoint in the FIDELIO-DKD trial was kidney specific and included a sustained decline in the estimated glomerular filtration rate (eGFR) of ≥40% from baseline. In contrast, the primary endpoint in the CREDENCE trial included a sustained decline in eGFR of ≥57% from baseline and cardiovascular (CV) death. This post hoc exploratory analysis investigated how differences in trial design-inclusion/exclusion criteria and definition of primary outcomes-influenced observed treatment effects. METHODS: Patients from FIDELIO-DKD who met the CKD inclusion criteria of the CREDENCE study (urine albumin: creatinine ratio >300-5000 mg/g and an eGFR of 30-<90 mL/min/1.73 m2 at screening) were included in this analysis. The primary endpoint was a cardiorenal composite (CV death, kidney failure, eGFR decrease of ≥57% sustained for ≥4 weeks or renal death). Patients with symptomatic heart failure with reduced ejection fraction were excluded from FIDELIO-DKD. Therefore, in a sensitivity analysis, we further adjusted for the baseline prevalence of heart failure. RESULTS: Of 4619/5674 (81.4%) patients who met the subgroup inclusion criteria, 49.6% were treated with finerenone and 50.4% received placebo. The rate of the cardiorenal composite endpoint was 43.9/1000 patient-years with finerenone compared with 59.5/1000 patient-years with placebo. The relative risk was significantly reduced by 26% with finerenone versus placebo [hazard ratio (HR) 0.74 (95% CI 0.63-0.87)]. In CREDENCE, the rate of the cardiorenal composite endpoint was 43.2/1000 patient-years with canagliflozin compared with 61.2/1000 patient-years with placebo; a 30% risk reduction was observed with canagliflozin [HR 0.70 (95% CI 0.59-0.82)]. CONCLUSIONS: This analysis highlights the pitfalls of direct comparisons between trials. When key differences in trial design are considered, FIDELIO-DKD and CREDENCE demonstrate cardiorenal benefits of a similar magnitude.

Molecular Signatures of Diabetic Kidney Disease Hiding in a Patient with Hypertension-Related Kidney Disease: A Clinical Pathologic Molecular Correlation.

The Kidney Precision Medicine Project (KPMP) seeks to establish a molecular atlas of the kidney in health and disease and improve our understanding of the molecular drivers of CKD and AKI. Herein, we describe the case of a 66-year-old woman with CKD who underwent a protocol KPMP kidney biopsy. Her clinical history included well-controlled diabetes mellitus, hypertension, and proteinuria. The patient's histopathology was consistent with modest hypertension-related kidney injury, without overt diabetic kidney disease. Transcriptomic signatures of the glomerulus, interstitium, and tubular subsegments were obtained from laser microdissected tissue. The molecular signatures that were uncovered revealed evidence of early diabetic kidney disease adaptation and ongoing active tubular injury with enriched pathways related to mesangial cell hypertrophy, glycosaminoglycan biosynthesis, and apoptosis. Molecular evidence of diabetic kidney disease was found across the nephron. Novel molecular assays can supplement and enrich the histopathologic diagnosis obtained from a kidney biopsy.

Effects of dapagliflozin on mortality in patients with chronic kidney disease: a pre-specified analysis from the DAPA-CKD randomized controlled trial.

AIMS: Mortality rates from chronic kidney disease (CKD) have increased in the last decade. In this pre-specified analysis of the DAPA-CKD trial, we determined the effects of dapagliflozin on cardiovascular and non-cardiovascular causes of death. METHODS AND RESULTS: DAPA-CKD was an international, randomized, placebo-controlled trial with a median of 2.4 years of follow-up. Eligible participants were adult patients with CKD, defined as a urinary albumin-to-creatinine ratio (UACR) 200-5000 mg/g and an estimated glomerular filtration rate (eGFR) 25-75 mL/min/1.73 m2. All-cause mortality was a key secondary endpoint. Cardiovascular and non-cardiovascular death was adjudicated by an independent clinical events committee. The DAPA-CKD trial randomized participants to dapagliflozin 10 mg/day (n = 2152) or placebo (n = 2152). The mean age was 62 years, 33% were women, the mean eGFR was 43.1 mL/min/1.73 m2, and the median UACR was 949 mg/g. During follow-up, 247 (5.7%) patients died, of whom 91 (36.8%) died due to cardiovascular causes, 102 (41.3%) due to non-cardiovascular causes, and in 54 (21.9%) patients, the cause of death was undetermined. The relative risk reduction for all-cause mortality with dapagliflozin (31%, hazard ratio [HR] [95% confidence interval (CI)] 0.69 [0.53, 0.88]; P = 0.003) was consistent across pre-specified subgroups. The effect on all-cause mortality was driven largely by a 46% relative risk reduction of non-cardiovascular death (HR [95% CI] 0.54 [0.36, 0.82]). Deaths due to infections and malignancies were the most frequently occurring causes of non-cardiovascular deaths and were reduced with dapagliflozin vs. placebo. CONCLUSION: In patients with CKD, dapagliflozin prolonged survival irrespective of baseline patient characteristics. The benefits were driven largely by reductions in non-cardiovascular death.

A pre-specified analysis of the DAPA-CKD trial demonstrates the effects of dapagliflozin on major adverse kidney events in patients with IgA nephropathy.

Immunoglobulin A (IgA) nephropathy is a common form of glomerulonephritis, which despite use of renin-angiotensin-aldosterone-system blockers and immunosuppressants, often progresses to kidney failure. In the Dapagliflozin and Prevention of Adverse Outcomes in Chronic Kidney Disease trial, dapagliflozin reduced the risk of kidney failure and prolonged survival in participants with chronic kidney disease with and without type 2 diabetes, including those with IgA nephropathy. Participants with estimated glomerular filtration rate (eGFR) 25-75 mL/min/1.73m2 and urinary albumin-to-creatinine ratio 200-5000 mg/g (22.6-565 mg/mol) were randomized to dapagliflozin 10mg or placebo, as adjunct to standard care. The primary composite endpoint was a sustained decline in eGFR of 50% or more, end-stage kidney disease, or death from a kidney disease-related or cardiovascular cause. Of 270 participants with IgA nephropathy (254 [94%] confirmed by previous biopsy), 137 were randomized to dapagliflozin and 133 to placebo, and followed for median 2.1 years. Overall, mean age was 51.2 years; mean eGFR, 43.8 mL/min/1.73m2; and median urinary albumin-to-creatinine ratio, 900 mg/g. The primary outcome occurred in six (4%) participants on dapagliflozin and 20 (15%) on placebo (hazard ratio, 0.29; 95% confidence interval, 0.12, 0.73). Mean rates of eGFR decline with dapagliflozin and placebo were -3.5 and -4.7 mL/min/1.73m2/year, respectively. Dapagliflozin reduced the urinary albumin-to-creatinine ratio by 26% relative to placebo. Adverse events leading to study drug discontinuation were similar with dapagliflozin and placebo. There were fewer serious adverse events with dapagliflozin, and no new safety findings in this population. Thus, in participants with IgA nephropathy, dapagliflozin reduced the risk of chronic kidney disease progression with a favorable safety profile.

Rationale and design of the Kidney Precision Medicine Project.

Chronic kidney disease (CKD) and acute kidney injury (AKI) are common, heterogeneous, and morbid diseases. Mechanistic characterization of CKD and AKI in patients may facilitate a precision-medicine approach to prevention, diagnosis, and treatment. The Kidney Precision Medicine Project aims to ethically and safely obtain kidney biopsies from participants with CKD or AKI, create a reference kidney atlas, and characterize disease subgroups to stratify patients based on molecular features of disease, clinical characteristics, and associated outcomes. An additional aim is to identify critical cells, pathways, and targets for novel therapies and preventive strategies. This project is a multicenter prospective cohort study of adults with CKD or AKI who undergo a protocol kidney biopsy for research purposes. This investigation focuses on kidney diseases that are most prevalent and therefore substantially burden the public health, including CKD attributed to diabetes or hypertension and AKI attributed to ischemic and toxic injuries. Reference kidney tissues (for example, living-donor kidney biopsies) will also be evaluated. Traditional and digital pathology will be combined with transcriptomic, proteomic, and metabolomic analysis of the kidney tissue as well as deep clinical phenotyping for supervised and unsupervised subgroup analysis and systems biology analysis. Participants will be followed prospectively for 10 years to ascertain clinical outcomes. Cell types, locations, and functions will be characterized in health and disease in an open, searchable, online kidney tissue atlas. All data from the Kidney Precision Medicine Project will be made readily available for broad use by scientists, clinicians, and patients.

Kidney Biomarkers and Major Adverse Kidney Events in Critically Ill Patients.

Background: Several biomarkers of AKI have been examined for their ability to predict AKI before serum creatinine. Few studies have focused on using kidney biomarkers to better predict major adverse kidney events (MAKE), an increasingly used composite outcome in critical care nephrology research. Methods: Single-center prospective study collecting blood and urine samples from critically ill patients with AKI Kidney Disease Improving Global Outcomes stage 2 or above, and matched controls from a single, tertiary care intensive care unit (ICU). Samples were collected at 24-48 hours after AKI diagnosis (patients) or ICU admission (controls), 5-7 days later, and 4-6 weeks after discharge for patients with AKI. The primary outcome of interest was MAKE at hospital discharge (MAKE-DC), consisting of the composite end point of death, RRT dependence, or a decrease in estimated glomerular filtration to <75% of baseline. Results: Serum/urinary neutrophil gelatinase-associated lipocalin (NGAL), serum/urinary cystatin C, and urinary kidney injury molecule-1 early in the AKI or ICU course were all significantly higher in patients with MAKE-DC compared with those not experiencing MAKE-DC. Additionally, serum/urinary NGAL and serum cystatin C measurements at the first time point remained significantly associated with MAKE events at 3, 6, and 12 months. Serum cystatin C, and to a lesser extent serum NGAL, significantly improved upon a logistic regression clinical prediction model of MAKE-DC (AUROC 0.94 and 0.87 versus 0.83; P=0.001 and P=0.02, respectively). Patients without MAKE-DC experienced a greater decline in serum NGAL from first to second measurement than those patients experiencing MAKE-DC. Conclusions: Early measures of kidney biomarkers in patients who are critically ill are associated with MAKE-DC. This relationship appears to be greatest with serum NGAL and cystatin C, which display additive utility to a clinical prediction model. Trending serum NGAL may also have utility in predicting MAKE-DC.

A Randomized Trial of Strategies Using Darbepoetin Alfa To Avoid Transfusions in CKD.

BACKGROUND: Exposure to high doses or a high cumulative dose of erythropoiesis-stimulating agents (ESAs) may contribute to cardiovascular events in patients with CKD and anemia. Whether using a low fixed ESA dose versus dosing based on a hemoglobin-based, titration-dose algorithm in such patients might reduce risks associated with high ESA doses and decrease the cumulative exposure-while reducing the need for red blood cell transfusions-is unknown. METHODS: In this phase-3, randomized trial involving 756 adults with stage-3 to -5 CKD and anemia, we evaluated incidence of red blood cell transfusions for participants randomized to receive darbepoetin given as a fixed dose (0.45 µg/kg every 4 weeks) versus administered according to a hemoglobin-based, titration-dose algorithm, for up to 2 years. Participants received transfusions as deemed necessary by the treating physician. RESULTS: There were 379 patients randomized to the fixed-dose group, and 377 to the titration-dose group. The percentage of participants transfused did not differ (24.1% and 24.4% for the fixed-dose and titration-dose group, respectively), with similar time to first transfusion. The titration-dose group achieved significantly higher median hemoglobin (9.9 g/dl) compared with the fixed-dose group (9.4 g/dl). The fixed-dose group had a significantly lower median cumulative dose of darbepoetin (median monthly dose of 30.9 µg) compared with the titration-dose group (53.6 µg median monthly dose). The FD and TD group received a median (Q1, Q3) cumulative dose per 4 weeks of darbepoetin of 30.9 (21.8, 40.0) µg and 53.6 (31.1, 89.9) µg, respectively; the median of the difference between treatment groups was -22.1 (95% CI, -26.1 to -18.1) µg. CONCLUSIONS: These findings indicate no evidence of difference in incidence of red blood cell transfusion for a titration-dose strategy versus a fixed-dose strategy for darbepoetin. This suggests that a low fixed dose of darbepoetin may be used as an alternative to a dose-titration approach to minimize transfusions, with less cumulative dosing.

Kidney Tubular Damage and Functional Biomarkers in Acute Kidney Injury Following Cardiac Surgery.

BACKGROUND: Cardiac surgery-associated acute kidney injury (AKI) is associated with increased morbidity and mortality. We examined the utility of combining biomarkers of kidney function loss (serum cystatin C) and kidney tubular damage (urine neutrophil gelatinase-associated lipocalin [NGAL] and Kidney Injury Molecule-1 [KIM-1]) for the prediction of post-cardiac surgery AKI. METHODS: Single-center prospective cohort study of 106 adults undergoing coronary artery bypass grafting and/or valve surgery with cardiopulmonary bypass (CPB). Primary outcome was postoperative in-hospital AKI defined by serum creatinine (SCr)-Kidney Disease: Improving Global Outcomes criteria. Biomarkers were measured preoperatively, 6 hours after CPB and on postoperative days (PODs) 1 to 4. RESULTS: A total of 23 subjects (21.7%) developed AKI. After adjusting for preoperative left ventricular ejection fraction, body mass index >30 kg/m2, and estimated glomerular filtration rate (eGFR) <60 ml/min per 1.73 m2, the combination of peak serum cystatin C and peak urine KIM-1/creatinine (Cr) (6 hours post-CPB to POD 1) above optimal cutoff significantly associated with postoperative AKI (odds ratio [OR]: 5.32; 95% confidence interval [CI]: 1.31-21.67; P = 0.020). This biomarker combination significantly improved the performance of the clinical model for the prediction of postoperative AKI (area under the curve [AUC]: 0.77, 95% CI: 0.65-0.90 for the clinical model alone versus 0.83, 95% CI: 0.73-0.93 for the clinical model with the addition of biomarker data, P = 0.049). CONCLUSIONS: Combining biomarkers of postoperative kidney function loss and postoperative kidney tubular damage significantly improved prediction of in-hospital AKI following cardiac surgery. Future large, multicenter studies are warranted to assess whether panels of biomarkers reflecting distinct pathobiology can be used to guide interventions and improve short- and long-term outcomes in patients undergoing cardiac surgery.

Effect of Blood Pressure Control on Long-Term Risk of End-Stage Renal Disease and Death Among Subgroups of Patients With Chronic Kidney Disease.

Background Our objective was to explore the effect of intensive blood pressure (BP) control on kidney and death outcomes among subgroups of patients with chronic kidney disease divided by baseline proteinuria, glomerular filtration rate, age, and body mass index. Methods and Results We included 840 MDRD (Modification of Diet in Renal Disease) trial and 1067 AASK (African American Study of Kidney Disease and Hypertension) participants. We used Cox models to examine whether the association between intensive BP control and risk of end-stage renal disease (ESRD) or death is modified by baseline proteinuria (≥0.44 versus <0.44 g/g), glomerular filtration rate (≥30 versus <30 mL/min per 1.73 m2), age (≥40 versus <40 years), or body mass index (≥30 versus <30 kg/m2). The median follow-up was 14.9 years. Strict (versus usual) BP control was protective against ESRD (hazard ratio [HR]ESRD, 0.77; 95% CI, 0.64-0.92) among those with proteinuria ≥0.44 g/g but not proteinuria <0.44 g/g. Strict (versus usual) BP control was protective against death (HRdeath, 0.73; 95% CI, 0.59-0.92) among those with glomerular filtration rate <30 mL/min per 1.73 m2 but not glomerular filtration rate ≥30 mL/min per 1.73 m2 (HRdeath, 0.98; 95% CI, 0.84-1.15). Strict (versus usual) BP control was protective against ESRD among those ≥40 years (HRESRD, 0.82; 95% CI, 0.71-0.94) but not <40 years. Strict (versus usual) BP control was also protective against ESRD among those with body mass index ≥30 kg/m2 (HRESRD, 0.75; 95% CI, 0.61-0.92) but not body mass index <30 kg/m2. Conclusions The ESRD and all-cause mortality benefits of intensive BP lowering may not be uniform across all subgroups of patients with chronic kidney disease. But intensive BP lowering was not associated with increased risk of ESRD or death among any subgroups that we examined.

Treatment of Anemia With Darbepoetin Prior to Dialysis Initiation and Clinical Outcomes: Analyses From the Trial to Reduce Cardiovascular Events With Aranesp Therapy (TREAT).

RATIONALE & OBJECTIVE: Evidence from clinical trials to guide patient preparation for maintenance dialysis therapy is limited. Although anemia is associated with mortality and cardiovascular (CV) disease in individuals initiating maintenance dialysis therapy, it is not known if treatment of anemia before dialysis therapy initiation with erythropoiesis-stimulating agents alters outcomes. STUDY DESIGN: Post hoc analysis of a randomized controlled trial. SETTING & PARTICIPANTS: Participants with type 2 diabetes and chronic kidney disease who progressed to dialysis therapy (n=590) in the Trial to Reduce Cardiovascular Events With Aranesp Therapy (TREAT). EXPOSURE: Randomized treatment assignment (darbepoetin vs placebo). OUTCOMES: All-cause mortality, CV mortality, nonfatal myocardial infarction, heart failure, and stroke within the first 180 days of dialysis therapy initiation. ANALYTICAL APPROACH: Proportional hazards regression. RESULTS: Overall, 590 of 4,038 (14.6%) participants initiated dialysis therapy during the trial (n=298 and 292 in the darbepoetin and placebo groups, respectively). Corresponding hemoglobin levels were 11.3±1.6 and 9.5±1.5g/dL (P<0.001). Death from any cause occurred in 31 (10.4%) participants assigned to darbepoetin and 28 (9.6%) assigned to placebo (HR, 1.16; 95% CI, 0.69-1.93), while death from CV causes occurred in 15 (5.0%) and 13 (4.5%) participants, respectively (HR, 1.21; 95% CI, 0.58-1.93). There were no differences in risk for nonfatal myocardial infarction or heart failure. Stroke occurred in 8 (2.8%) participants assigned to darbepoetin and 1 (0.3%) assigned to placebo (HR, 8.6; 95% CI, 1.1-68.7). LIMITATIONS: Post hoc analyses of a subgroup of study participants. CONCLUSIONS: Despite initiating dialysis therapy with a higher hemoglobin level, prior treatment with darbepoetin was not associated with a reduction in mortality, myocardial infarction, or heart failure in the first 180 days, but a higher frequency of stroke was observed. In the absence of more definitive data, this may inform decisions regarding the use of erythropoiesis-stimulating agents to treat mild to moderate anemia in patients with type 2 diabetes and chronic kidney disease nearing dialysis therapy initiation.

Rationale, design, and baseline characteristics of the CArdiovascular safety and Renal Microvascular outcomE study with LINAgliptin (CARMELINA®): a randomized, double-blind, placebo-controlled clinical trial in patients with type 2 diabetes and high cardio-renal risk.

BACKGROUND: Cardiovascular (CV) outcome trials in type 2 diabetes (T2D) have underrepresented patients with chronic kidney disease (CKD), leading to uncertainty regarding their kidney efficacy and safety. The CARMELINA® trial aims to evaluate the effects of linagliptin, a DPP-4 inhibitor, on both CV and kidney outcomes in a study population enriched for cardio-renal risk. METHODS: CARMELINA® is a randomized, double-blind, placebo-controlled clinical trial conducted in 27 countries in T2D patients at high risk of CV and/or kidney events. Participants with evidence of CKD with or without CV disease and HbA1c 6.5-10.0% (48-86 mmol/mol) were randomized 1:1 to receive linagliptin once daily or matching placebo, added to standard of care adjusted according to local guidelines. The primary outcome is time to first occurrence of CV death, non-fatal myocardial infarction, or non-fatal stroke. The key secondary outcome is a composite of time to first sustained occurrence of end-stage kidney disease, ≥ 40% decrease in estimated glomerular filtration rate (eGFR) from baseline, or renal death. CV and kidney events are prospectively adjudicated by independent, blinded clinical event committees. CARMELINA® was designed to continue until at least 611 participants had confirmed primary outcome events. Assuming a hazard ratio of 1.0, this provides 90% power to demonstrate non-inferiority of linagliptin versus placebo within the pre-specified non-inferiority margin of 1.3 at a one-sided α-level of 2.5%. If non-inferiority of linagliptin for the primary outcome is demonstrated, then its superiority for both the primary outcome and the key secondary outcome will be investigated with a sequentially rejective multiple test procedure. RESULTS: Between July 2013 and August 2016, 6980 patients were randomized and took ≥ 1 dose of study drug (40.6, 33.1, 16.9, and 9.4% from Europe, South America, North America, and Asia, respectively). At baseline, mean ± SD age was 65.8 ± 9.1 years, HbA1c 7.9 ± 1.0%, BMI 31.3 ± 5.3 kg/m2, and eGFR 55 ± 25 mL/min/1.73 m2. A total of 5148 patients (73.8%) had prevalent kidney disease (defined as eGFR < 60 mL/min/1.73 m2 or macroalbuminuria [albumin-to-creatinine ratio > 300 mg/g]) and 3990 patients (57.2%) had established CV disease with increased albuminuria; these characteristics were not mutually exclusive. Microalbuminuria (n = 2896 [41.5%]) and macroalbuminuria (n = 2691 [38.6%]) were common. CONCLUSIONS: CARMELINA® will add important information regarding the CV and kidney disease clinical profile of linagliptin by including an understudied, vulnerable cohort of patients with T2D at highest cardio-renal risk. Trial registration ClinicalTrials.gov identifier-NCT01897532; registered July 9, 2013.

C-Reactive Protein and Risk of ESRD: Results From the Trial to Reduce Cardiovascular Events With Aranesp Therapy (TREAT).

BACKGROUND: To better understand a potential association of elevated C-reactive protein (CRP) level with progression of chronic kidney disease (CKD), we examined the relationship of CRP level with the development of end-stage renal disease (ESRD) in the Trial to Reduce Cardiovascular Events With Aranesp Therapy (TREAT). STUDY DESIGN: Post hoc analysis of a randomized controlled trial. SETTING & PARTICIPANTS: 4,038 patients with type 2 diabetes, CKD, and anemia in TREAT. PREDICTOR: Baseline serum CRP concentrations. OUTCOMES: The primary outcome was development of ESRD; secondary outcomes included doubling of serum creatinine level, a composite of ESRD/serum creatinine doubling, and a composite of death or ESRD. MEASUREMENTS: We fit unadjusted and adjusted Cox regression models to test the association of baseline CRP level with time to the development of the outcomes of interest. RESULTS: Mean age of participants was 67 years, 43% were men, and 64% were white. Approximately half (48%) the patients had CRP levels > 3.0mg/L; 668 patients developed ESRD, and 1,270 developed the composite outcome of death or ESRD. Compared with patients with baseline CRP levels ≤ 3.0mg/L, those with moderately/markedly elevated CRP levels (≥6.9mg/L; 24% of patients) had a higher adjusted risk for ESRD (HR, 1.32; 95% CI, 1.07-1.63) and the composite outcome of death or ESRD (HR, 1.41; 95% CI, 1.21-1.64). Although nonsignificant, similar trends were noted in competing-risk models. LIMITATIONS: Results may not be generalizable to nondiabetic CKD or diabetic CKD in the absence of anemia. CONCLUSIONS: Elevated baseline CRP levels are common in type 2 diabetic patients with anemia and CKD and are associated with the future development of ESRD and the composite of death or ESRD.

APOL1 renal-risk variants associate with reduced cerebral white matter lesion volume and increased gray matter volume.

To assess apolipoprotein L1 gene (APOL1) renal-risk-variant effects on the brain, magnetic resonance imaging (MRI)-based cerebral volumes and cognitive function were assessed in 517 African American-Diabetes Heart Study (AA-DHS) Memory IN Diabetes (MIND) and 2568 hypertensive African American Systolic Blood Pressure Intervention Trial (SPRINT) participants without diabetes. Within these cohorts, 483 and 197 had cerebral MRI, respectively. AA-DHS participants were characterized as follows: 60.9% female, mean age of 58.6 years, diabetes duration 13.1 years, estimated glomerular filtration rate of 88.2 ml/min/1.73 m(2), and a median spot urine albumin to creatinine ratio of 10.0 mg/g. In additive genetic models adjusting for age, sex, ancestry, scanner, intracranial volume, body mass index, hemoglobin A1c, statins, nephropathy, smoking, hypertension, and cardiovascular disease, APOL1 renal-risk-variants were positively associated with gray matter volume (ß = 3.4 × 10(-3)) and negatively associated with white matter lesion volume (ß = -0.303) (an indicator of cerebral small vessel disease) and cerebrospinal fluid volume (ß= -30707) (all significant), but not with white matter volume or cognitive function. Significant associations corresponding to adjusted effect sizes (ß/SE) were observed with gray matter volume (0.16) and white matter lesion volume (-0.208), but not with cerebrospinal fluid volume (-0.251). Meta-analysis results with SPRINT Memory and Cognition in Decreased Hypertension (MIND) participants who had cerebral MRI were confirmatory. Thus, APOL1 renal-risk-variants are associated with larger gray matter volume and lower white matter lesion volume suggesting lower intracranial small vessel disease.

Differences in Whole Blood Platelet Aggregation at Baseline and in Response to Aspirin and Aspirin Plus Clopidogrel in Patients With Versus Without Chronic Kidney Disease.

Thrombotic events while receiving antiplatelet agents (APAs) are more common in subjects with versus without chronic kidney disease (CKD). Data on antiplatelet effects of APA in CKD are scarce and limited by lack of baseline platelet function before APA treatment. We hypothesized subjects with stages 4 to 5 CKD versus no CKD have greater baseline platelet aggregability and respond poorly to aspirin and clopidogrel. In a prospective controlled study, we measured whole blood platelet aggregation (WBPA) in 28 CKD and 16 non-CKD asymptomatic stable outpatients not on APA, frequency-matched for age, gender, obesity, and diabetes mellitus. WBPA was remeasured after 2 weeks of each aspirin and aspirin plus clopidogrel. The primary outcome was percent inhibition of platelet aggregation (IPA) from baseline. The secondary outcome was residual platelet aggregability (RPA; proportion with <50% IPA). Baseline platelet aggregability was similar between groups except adenosine diphosphate-induced WBPA, which was higher in CKD versus non-CKD; median (interquartile range) = 13.5 (9.5 to 16.0) versus 9.0 (6.0 to 12.0) Ω, p = 0.007. CKD versus non-CKD participants had lower clopidogrel-induced IPA, 38% versus 72%, p = 0.04. A greater proportion of CKD versus non-CKD participants had RPA after clopidogrel treatment (56% vs 8.3%, p = 0.01). There were no significant interactions between CKD and the presence of cytochrome P450 2C19 polymorphisms for platelet aggregability in clopidogrel-treated participants. In conclusion, CKD versus non-CKD subjects exhibited similar platelet aggregation at baseline, similar aspirin effects and greater RPA on clopidogrel, which was independent of cytochrome P450 2C19 polymorphisms.

Race and ethnicity influences on cardiovascular and renal events in patients with diabetes mellitus.

BACKGROUND: The incidence of end-stage renal disease (ESRD) has been consistently shown to be higher among blacks and Hispanics compared to whites with unmeasured risk factors and access to care as suggested explanations. In a high-risk cohort with frequent protocol-directed follow-up, we evaluated the influence of race on cardiovascular (CV) outcomes and incidence of ESRD. METHODS: TREAT was a randomized, double-blind, placebo-controlled study. This secondary analysis focused on role of race on outcomes. TREAT enrolled 4,038 patients with type 2 diabetes, chronic kidney disease (estimated glomerular filtration rate 20-60 mL/min per 1.73 m(2)), and anemia (hemoglobin level ≤11 g/dL) treated with either darbepoetin alfa or placebo. We compared self-described black and Hispanic patients to white patients with regard to baseline characteristics and outcomes, including mortality, CV outcomes (myocardial infarction, stroke, heart failure, resuscitated sudden death, and coronary revascularization), and incident ESRD. Multivariate adjusted Cox models were developed for these outcomes. RESULTS: Black and Hispanic patients were younger, more likely women, had less prior CV disease, and higher blood pressure. During a mean follow-up of 2.4 years with comparable access to care, blacks and Hispanics had a greater risk of ESRD but a significant lower risk of myocardial infarction and coronary revascularization than whites. After adjusting for confounders, blacks remained at significantly greater risk of ESRD than whites (hazard ratio 1.53, 95% CI 1.26-1.85, P < .001), whereas this ESRD risk did not persist among Hispanics. CONCLUSION: Despite similar access to care and lower CV event rates, the risk of ESRD was higher among blacks and Hispanics than whites. For blacks, but not Hispanics, this increase was independent of known attributable risk factors.