The Use of Telemedicine by US Nephrologists for In-Center Hemodialysis Care During the Pandemic: An Analysis of National Medicare Claims

Rationale & Objective

Because of coronavirus disease 2019 (COVID-19), the US government issued emergency waivers in March 2020 that removed regulatory barriers around the use of telemedicine. For the first time, nephrologists were reimbursed for telemedicine care delivered during in-center hemodialysis. We examined the use of telemedicine for in-center hemodialysis during the first 16 months of the pandemic.

Study Design

We ascertained telemedicine modifiers on nephrologist claims. We used multivariable regression to examine time trends and patient, dialysis facility, and geographic correlates of telemedicine use. We also examined whether the estimated effects of predictors of telemedicine use changed over time.

Setting & Participants

US Medicare beneficiaries receiving in-center hemodialysis between March 1, 2020, and June 30, 2021.

Exposures

Patient, geographic, and dialysis facility characteristics.

Outcomes

The use of telehealth for in-center hemodialysis care.

Analytic Approach

Retrospective cohort analysis.

Results

Among 267,434 Medicare beneficiaries identified, the reported use of telemedicine peaked at 9% of patient-months in April 2020 and declined to 2% of patient-months by June 2021. Telemedicine use varied geographically and was more common in areas that were remote and socioeconomically disadvantaged. Patients were more likely to receive care by telemedicine in areas with higher incidence of COVID-19, although the predictive value of COVID-19 diminished later in the pandemic. Patients were more likely to receive care using telemedicine if they were at facilities with more staff, and the use of telemedicine varied by facility ownership type.

Limitations

Limited reporting of telemedicine on claims could lead to underestimation of its use. Reported telemedicine use was higher in an analysis designed to address this limitation by focusing on patients whose physicians used telemedicine at least once during the pandemic.

Conclusions

Some US nephrologists continued to use telemedicine for in-center hemodialysis throughout the pandemic, even as the association between COVID-19 incidence and telemedicine use diminished over time. These findings highlight unique challenges and opportunities to the future use of telemedicine in dialysis care.

A Phase II randomized controlled trial evaluated antithrombotic treatment with fesomersen in patients with kidney failure on hemodialysis

Patients with kidney failure on hemodialysis (KF-HD) are at high risk for both atherothrombotic events and bleeding. This Phase IIb study evaluated the dose-response of fesomersen, an inhibitor of hepatic Factor XI expression, versus placebo, for bleeding and atherothrombosis in patients with KF-HD. Patients were randomized to receive fesomersen 40, 80, or 120 mg once-monthly, or matching placebo, for up to 12 months. The primary safety endpoint was a composite of major bleeding and clinically relevant non-major bleeding (MB/CRNMB). Exploratory endpoints included post-dialysis arterio-venous (AV)-access bleeding, major atherothrombotic events (composite of fatal or non-fatal myocardial infarction, ischemic stroke, acute limb ischemia/major amputation, systemic embolism, symptomatic venous thromboembolism), AV-access thrombosis, and clotting of the hemodialysis circuit. Of 308 participants randomized, 307 received study treatment and were analyzed. Fesomersen led to a dose-dependent and sustained reduction of steady-state median FXI levels by 53.6% (40 mg group), 71.3% (80 mg group), 86.0% (120 mg group), and 1.9% in the placebo group. MB/CRNMB events occurred in 6.5% (40 mg group), 5.1% (80 mg group), 3.9% (120 mg group), and in 4.0% of those receiving placebo (pooled fesomersen versus placebo P = 0.78). Major atherothrombotic events occurred in 1 patient (1.3%) in each treatment arm. MB/CRNMB bleeding and post-dialysis AV-access bleeding were not related to predicted FXI levels. Lower predicted FXI levels were associated with reductions in hemodialysis circuit clotting (P = 0.002) and AV-access thrombosis (P = 0.014). In patients with KF-HD, fesomersen produced a dose-dependent reduction in FXI levels associated with similar rates of major bleeding compared with placebo. REGISTRATION: URL: https://www.clinicaltrials.gov; unique identifier: NCT04534114.

Intradialytic Hypotension and Mortality in Adolescents and Young Adults With Kidney Failure Receiving Maintenance Hemodialysis

Rationale & Objective

Intradialytic hypotension (IDH) is associated with mortality in adults with kidney failure requiring hemodialysis (HD); however, large-scale pediatric studies are lacking. Moreover, there is no evidence-based consensus definition of IDH in pediatric literature. We aimed to examine the association of commonly used definitions of IDH with mortality in adolescents and young adults.

Study Design

This was a retrospective observational cohort study.

Setting & Participants

In total, 1,199 adolescents and young adults (N = 320, aged 10-18 years and N = 879, aged 19-21 years) who initiated HD in a large dialysis organization were included.

Exposures

This study used different definitions of IDH.

Outcome

The study outcome was 2-year all-cause mortality.

Analytical Approach

Several definitions of IDH were selected a priori based on a literature review. Patients were classified as having IDH if it was present in at least 30% of HD treatments during the first 90 days after dialysis initiation. Cox proportional hazards regression was used to test whether IDH associated with 2-year all-cause mortality.

Results

Over a 2-year follow-up period, 54 (4.5%) patients died. Dependent on its definition, IDH was present in 2.9%-61.1% of patients. After the multivariable adjustment for sociodemographic and clinical characteristics, we found no association of IDH with mortality. Results were consistent across subgroups stratified by age (aged <18 and 19-21 years) and predialysis systolic blood pressure (<120, 120-150, and >150 mm Hg). We also examined IDH as occurring in <5%, 5%-29%, 30%-50%, and >50% of baseline treatments, and did not find a dose-response association with mortality (P > 0.05).

Limitations

Owing to low event rates, our current sample size may have been too small to detect a difference in mortality.

Conclusions

Our study found that IDH was not associated with mortality in adolescents and young adults.

Anticoagulation with osocimab in patients with kidney failure undergoing hemodialysis: a randomized phase 2 trial

Individuals with kidney failure undergoing hemodialysis are at elevated risk for thromboembolic events. Factor (F) XI, which is in the intrinsic pathway of coagulation, is emerging as an attractive target for new anticoagulants that may be safer than existing agents. Osocimab-an inhibitory FXIa antibody-is a potential treatment option for such patients. We conducted a phase 2b, double-blind, placebo-controlled trial, in which 704 participants (448 male, 256 female) with kidney failure undergoing hemodialysis were randomized to receive lower- or higher-dose osocimab or placebo. In total, 686 participants (436 male, 250 female) received treatment for ≤18 months (planned minimal treatment period of 6 months). The co-primary outcomes were clinically relevant bleeding (a composite of major and clinically relevant nonmajor bleeding) and a composite of the incidence of moderate, severe or serious adverse events. Clinically relevant bleeding occurred in 16/232 (6.9%) and 11/224 (4.9%) participants who received lower- and higher-dose osocimab, respectively, and in 18/230 participants (7.8%) who received a placebo. For the composite adverse event endpoint, incidences were 51%, 47% and 43% in the lower-dose osocimab, higher-dose osocimab and placebo groups, respectively. These results suggest that osocimab is associated with a low risk of bleeding and is generally well tolerated in this population; findings that require confirmation in larger trials. ClinicalTrials.gov identifier, NCT04523220 .

Dialysis Modality, Transplant Characteristics, and Incident Atrial Fibrillation After Kidney Transplant: An Observational Study Using USRDS Data

Rationale & Objective

Atrial fibrillation is the most common arrhythmia and is increasing in prevalence. The prevalence of atrial fibrillation is high among patients receiving dialysis, affecting ∼21.3% of the patients receiving hemodialysis and 15.5% of those receiving peritoneal dialysis. The association of previous dialysis modality with incident atrial fibrillation in patients after receiving their first kidney transplant has not been studied.

Study Design

We used the United States Renal Data System to retrospectively identify adult, Medicare-insured patients who received their first kidney transplant between January 1, 2005, and September 30, 2012 and who had not previously been diagnosed with atrial fibrillation.

Setting & Participants

The study included 43,621 patients who were aged 18 years older when receiving a first kidney transplant between January 1, 2005, and September 30, 2012 and whose primary payer was Medicare (parts A and B) at the time of transplantation and the 6 months preceding it.

Exposure

Dialysis modality used before transplant.

Outcome

Time to incidence of atrial fibrillation up to 3 years posttransplant.

Analytical Approach

Multivariable Cox regression was used to estimate HRs.

Results

Of 43,621 patients, 84.9% received hemodialysis and 15.1% received peritoneal dialysis before transplant. The mean ± SD age was 51 ± 13.6 years; 60.8% were male, 55.6% White, and 35.8% Black race. The mean dialysis vintage was 4.3 ± 2.8 years. Newly diagnosed atrial fibrillation after kidney transplant occurred in 286 patients (during 15,363 person-years) who had received peritoneal dialysis and in 2,315 patients (during 83,536 person-years) who had received hemodialysis. After multivariable adjustment, atrial fibrillation was 20% (95% CI, 4%-38%) more likely in those who had been receiving hemodialysis versus peritoneal dialysis, regardless of whether death was considered a competing risk or a censoring event. Each year of pretransplant dialysis vintage increased the risk of posttransplant atrial fibrillation by 6% (95% CI, 3%-9%).

Limitations

Residual confounding; data from billing claims does not specify the duration of atrial fibrillation or whether it is valvular.

Conclusions

Pretransplant hemodialysis, as compared with peritoneal dialysis, was associated with higher risk of newly diagnosed atrial fibrillation after a first kidney transplant.

Plain-Language Summary

New-onset atrial fibrillation (AF) occurs in 7% of kidney transplant recipients in the first 3 years posttransplantation. We conducted this study to determine whether pretransplant dialysis modality was associated with posttransplant AF. We identified 43,621 patients; 84.9% used hemodialysis and 15.1% used peritoneal dialysis pretransplant. Multivariable Cox regression was used to estimate hazard ratios. We found that patients receiving hemodialysis pretransplant were at 20% increased risk of developing posttransplant AF as compared with patients receiving peritoneal dialysis. As our understanding of transplant-specific risk factors for AF increases, we may be able to better risk-stratify transplant patients and develop monitoring and management strategies that can improve outcomes.

Challenges in the management of the kidney allograft: from decline to failure: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

In March 2022, Kidney Disease: Improving Global Outcomes (KDIGO) held a virtual Controversies Conference to address the important but rarely examined phase during which the kidney transplant is failing or has failed. In addition to discussing the definition of a failing allograft, 4 broad areas were considered in the context of a declining functioning graft: prognosis and kidney failure trajectory; immunosuppression strategies; management of medical and psychological complications, and patient factors; and choice of kidney replacement therapy or supportive care following graft loss. Identifying and paying special attention to individuals with failing allografts was felt to be important in order to prepare patients psychologically, manage immunosuppression, address complications, prepare for dialysis and/or retransplantation, and transition to supportive care. Accurate prognostication tools, although not yet widely available, were embraced as necessary to define allograft survival trajectories and the likelihood of allograft failure. The decision of whether to withdraw or continue immunosuppression after allograft failure was deemed to be based most appropriately on risk-benefit analysis and likelihood of retransplantation within a few months. Psychological preparation and support was identified as a critical factor in patient adjustment to graft failure, as was early communication. Several models of care were noted that enabled a medically supportive transition back to dialysis or retransplantation. Emphasis was placed on the importance of dialysis-access readiness before initiation of dialysis, in order to avoid use of central venous catheters. The centrality of the patient to all management decisions and discussions was deemed to be paramount. Patient "activation," which can be defined as engaged agency, was seen as the most effective way to achieve success. Unresolved controversies, gaps in knowledge, and areas for research were also stressed in the conference deliberations.

Trends and perspectives for improving quality of chronic kidney disease care: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

Chronic kidney disease (CKD) affects over 850 million people globally, and the need to prevent its development and progression is urgent. During the past decade, new perspectives have arisen related to the quality and precision of care for CKD, owing to the development of new tools and interventions for CKD diagnosis and management. New biomarkers, imaging methods, artificial intelligence techniques, and approaches to organizing and delivering healthcare may help clinicians recognize CKD, determine its etiology, assess the dominant mechanisms at given time points, and identify patients at high risk for progression or related events. As opportunities to apply the concepts of precision medicine for CKD identification and management continue to be developed, an ongoing discussion of the potential implications for care delivery is required. The 2022 KDIGO Controversies Conference on Improving CKD Quality of Care: Trends and Perspectives examined and discussed best practices for improving the precision of CKD diagnosis and prognosis, managing the complications of CKD, enhancing the safety of care, and maximizing patient quality of life. Existing tools and interventions currently available for the diagnosis and treatment of CKD were identified, with discussion of current barriers to their implementation and strategies for improving the quality of care delivered for CKD. Key knowledge gaps and areas for research were also identified.

Market Competition and Anemia Management in the United States Following Dialysis Payment Reform

BACKGROUND

Whether market competition influences health care provider responses to national reimbursement reforms is unknown.

OBJECTIVES

We examined whether changes in anemia management after the expansion of Medicare's dialysis payment bundle varied with market competition.

RESEARCH DESIGN

With data from the US dialysis registry, we used a difference-in-differences (DID) design to estimate the independent associations of market competition with changes in anemia management after dialysis reimbursement reform.

SUBJECTS

A total of 326,150 patients underwent in-center hemodialysis in 2009 and 2012, representing periods before and after reimbursement reform.

MEASURES

Outcomes were erythropoiesis-stimulating agent (ESA) and intravenous iron dosage, the probability of hemoglobin <9 g/dL, hospitalizations, and mortality. We also examined serum ferritin concentration, an indicator of body iron stores. We used a dichotomous market competition index, with less competitive areas defined as effectively having <2 competing dialysis providers.

RESULTS

Compared with areas with more competition, patients in less competitive areas had slightly more pronounced declines in ESA dose (60% vs. 57%) following reimbursement reform (DID estimate: -3%; 95% CI, -5% to -1%) and less pronounced declines in intravenous iron dose (-14% vs. -19%; DID estimate: 5%; 95% CI, 1%-9%). The likelihoods of hemoglobin <9 g/dL, hospitalization, and mortality did not vary with market competition. Serum ferritin concentrations in 2012 were 4% (95% CI, 3%-6%) higher in less competitive areas.

CONCLUSIONS

After the expansion of Medicare's dialysis payment bundle, ESA use declined by more, and intravenous iron use declined by less in concentrated markets. More aggressive cost-reduction strategies may be implemented in less competitive markets.

Novel anemia therapies in chronic kidney disease: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

Anemia is common in patients with chronic kidney disease and is associated with a high burden of morbidity and adverse clinical outcomes. In 2012, Kidney Disease: Improving Global Outcomes (KDIGO) published a guideline for the diagnosis and management of anemia in chronic kidney disease. Since then, new data from studies assessing established and emerging therapies for the treatment of anemia and iron deficiency have become available. Beginning in 2019, KDIGO planned 2 Controversies Conferences to review the new evidence and its potential impact on the management of anemia in clinical practice. Here, we report on the second of these conferences held virtually in December 2021, which focused on a new class of agents-the hypoxia-inducible factor-prolyl hydroxylase inhibitors (HIF-PHIs). This report provides a review of the consensus points and controversies from this second conference and highlights areas that warrant prioritization for future research.

Vadadustat for treatment of anemia in patients with dialysis-dependent chronic kidney disease receiving peritoneal dialysis

BACKGROUND

Hypoxia-inducible factor prolyl hydroxylase inhibitors such as vadadustat may provide an oral alternative to injectable erythropoiesis-stimulating agents for treating anemia in patients receiving peritoneal dialysis. In two randomized (1:1), global, phase 3, open-label, sponsor-blind, parallel-group, active-controlled noninferiority trials in patients with dialysis-dependent chronic kidney disease (INNO2VATE), vadadustat was noninferior to darbepoetin alfa with respect to cardiovascular safety and hematological efficacy. Vadadustat's effects in patients receiving only peritoneal dialysis is unclear.

METHODS

We conducted a post hoc analysis of patients in the INNO2VATE trials receiving peritoneal dialysis at baseline. The prespecified primary safety endpoint was time to first major cardiovascular event (MACE; defined as all-cause mortality or nonfatal myocardial infarction or stroke). The primary efficacy endpoint was mean change in hemoglobin from baseline to the primary evaluation period (Weeks 24-36).

RESULTS

Of the 3923 patients randomized in the two INNO2VATE trials, 309 were receiving peritoneal dialysis (vadadustat, n = 152; darbepoetin alfa, n = 157) at baseline. Time to first MACE was similar in the vadadustat and darbepoetin alfa groups [hazard ratio 1.10; 95% confidence interval (CI) 0.62, 1.93]. In patients receiving peritoneal dialysis, the difference in mean change in hemoglobin concentrations was -0.10 g/dL (95% CI -0.33, 0.12) in the primary evaluation period. The incidence of treatment-emergent adverse events (TEAEs) was 88.2% versus 95.5%, and serious TEAEs was 52.6% versus 73.2% in the vadadustat and darbepoetin alfa groups, respectively.

CONCLUSIONS

In the subgroup of patients receiving peritoneal dialysis in the phase 3 INNO2VATE trials, safety and efficacy of vadadustat were similar to darbepoetin alfa.

Managing the symptom burden associated with maintenance dialysis: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

Individuals with kidney failure undergoing maintenance dialysis frequently report a high symptom burden that can interfere with functioning and diminish life satisfaction. Until recently, the focus of nephrology care for dialysis patients has been related primarily to numerical targets for laboratory measures, and outcomes such as cardiovascular disease and mortality. Routine symptom assessment is not universal or standardized in dialysis care. Even when symptoms are identified, treatment options are limited and are initiated infrequently, in part because of a paucity of evidence in the dialysis population and the complexities of medication interactions in kidney failure. In May of 2022, Kidney Disease: Improving Global Outcomes (KDIGO) held a Controversies Conference-Symptom-Based Complications in Dialysis-to identify the optimal means for diagnosing and managing symptom-based complications in patients undergoing maintenance dialysis. Participants included patients, physicians, behavioral therapists, nurses, pharmacists, and clinical researchers. They outlined foundational principles and consensus points related to identifying and addressing symptoms experienced by patients undergoing dialysis and described gaps in the knowledge base and priorities for research. Healthcare delivery and education systems have a responsibility to provide individualized symptom assessment and management. Nephrology teams should take the lead in symptom management, although this does not necessarily mean taking ownership of all aspects of care. Even when options for clinical response are limited, clinicians should focus on acknowledging, prioritizing, and managing symptoms that are most important to individual patients. A recognized factor in the initiation and implementation of improvements in symptom assessment and management is that they will be based on locally existing needs and resources.

Hemodialysis Versus Peritoneal Dialysis Drug Expenditures: A Comparison Within the Private Insurance Market

Rationale and Objective

Recent initiatives aim to improve patient satisfaction and autonomy by increasing the use of peritoneal dialysis (PD) in the United States. However, limited knowledge is available about the costs of different dialysis modalities, particularly those incurred by private insurers. In this study, we compared the costs of injectable dialysis drugs (and their oral equivalents) paid by insurers between privately insured patients receiving hemodialysis and PD.

Study Design

A retrospective cohort study.

Setting and Participants

From a private insurance claims database, we identified patients who started receiving PD or in-center hemodialysis between January 1, 2017, and December 31, 2020.

Exposure

Patients started receiving PD.

Outcomes

Average annual injectable drug and aggregate expenditures and expenditure subcategories.

Analytical Approach

Patients who started receiving PD were propensity matched to similar patients who started receiving hemodialysis based on the year of dialysis initiation, patient demographics, health, geography, and comorbidities. Cost ratios (CRs) were estimated from generalized linear models.

Results

We matched 284 privately insured patients who started receiving PD 1:1 with patients started receiving in-center hemodialysis. The average annual injectable drug expenditures for hemodialysis were 2-fold higher (CR: 1.99; 95% CI, 1.62-2.44) than that for PD. Compared those receiving PD, patients receiving hemodialysis incurred significantly lower nondrug dialysis-related expenditures (0.85; 95% CI, 0.76-0.94). The average annual expenditures for non-dialysis-dependent outpatient services were significantly higher among patients who underwent in-center hemodialysis (CR: 1.44; 95% CI, 1.10-1.90). Although aggregate and inpatient hospitalization expenditures were higher for in-center hemodialysis, these differences did not reach statistical significance.

Limitations

Small sample sizes may have restricted our ability to identify differences in some cost categories.

Conclusions

Compared with privately insured patients who started receiving PD, patients starting in-center hemodialysis incurred higher expenditures for injectable dialysis drugs, whereas differences in other expenditure categories varied. Recent increases in the use of PD may lead to reductions in injectable dialysis drug costs among privately insured patients.

Plain Language Summary

Recent initiatives aim to improve patient satisfaction and autonomy by increasing the use of peritoneal dialysis (PD) in the United States. However, limited knowledge is available about the costs of different dialysis modalities, particularly those incurred by private insurers. In this study, we compared the costs of injectable dialysis drugs (and their oral equivalents) provided by insurers between privately insured patients receiving hemodialysis and PD. We found that the average annual injectable drug expenditures for hemodialysis were 2.0-fold higher compared with those for PD. These findings suggest that the recent increase in the use of PD may lead to reductions in injectable dialysis drug costs among privately insured patients.

Safety Endpoints With Vadadustat Versus Darbepoetin Alfa in Patients With NonDialysis-Dependent CKD: A Post Hoc Regional Analysis of the PRO2TECT Randomized Clinical Trial of ESA-Treated Patients

Rationale & Objective

In the PRO₂TECT trials, vadadustat was found to be noninferior to darbepoetin alfa in hematologic efficacy but not for major adverse cardiovascular events (MACE; all-cause death or nonfatal myocardial infarction or stroke) in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD). We investigated the regional differences in MACE in the PRO₂TECT trials.

Study Design

Phase 3, global, open-label, randomized, active-controlled clinical trial.

Setting & Participants

A total of 1,725 erythropoiesis-stimulating agent (ESA)-treated patients with anemia and NDD-CKD.

Intervention

1:1 randomization to receive vadadustat or darbepoetin alfa.

Outcomes

The primary safety end point was the time to first MACE.

Results

At baseline, patients in Europe (n=444) were primarily treated with darbepoetin alfa, showed higher proportions on low ESA doses (<90 U/kg/wk epoetin alfa equivalents) with a hemoglobin concentration of ≥10 g/dL compared with patients in the US (n=665) and non-US/non-Europe (n=614) regions. The MACE rates per 100 person-years in the 3 vadadustat groups across regions were 14.5 in the US, 11.6 in Europe, and 10.0 in the non-US/non-Europe groups, whereas event rates in the darbepoetin alfa group were considerably lower in Europe than in the US and non-US/non-Europe groups (6.7 vs 13.3 and 10.5, respectively). The overall hazard ratio for MACE for vadadustat vs darbepoetin alpha was 1.16; 95% CI, 0.93-1.45, but varied by geographical region, with a greater hazard ratio seen in Europe (US, 1.07; 95% CI, 0.78-1.46; Europe, 2.05; 95% CI, 1.24-3.39; non-US/non-Europe, 0.91; 95% CI, 0.60-1.37); interaction between study treatment and geographical region, P = 0.07). In Europe, ESA rescue was associated with a higher risk of MACE in both groups.

Limitations

Several analyses are exploratory.

Conclusions

In this trial, there was a low risk of MACE in the darbepoetin alfa group in Europe. Patients in Europe were generally on low doses of ESA, with hemoglobin already within target range. The low risk of MACE may have been related to a limited need to switch and titrate darbepoetin alfa compared with the non-US/non-Europe group.

Funding

Akebia Therapeutics, Inc.

Trial Registration

ClinicalTrials.gov identifier: NCT02680574.

Safety Endpoints With Vadadustat Versus Darbepoetin Alfa in Patients With Non-Dialysis-Dependent CKD: A Post Hoc Regional Analysis of the PRO2TECT Randomized Clinical Trial of ESA-Naïve Patients

Rationale & Objective

Prespecified analyses of the PRO₂TECT trials comparing the safety of the oral hypoxia-inducible factor prolyl hydroxylase inhibitor vadadustat with darbepoetin alfa in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD) found no difference in major adverse cardiovascular events (MACE; death from any cause or nonfatal myocardial infarction or stroke) among US patients and a higher risk among patients treated with vadadustat outside the United States. We investigated regional differences in MACE in the PRO₂TECT trial that enrolled 1,751 patients previously untreated with erythropoiesis-stimulating agents.

Study Design

Phase 3, global, open-label, randomized, active-controlled clinical trial.

Setting and Participants

Erythropoiesis-stimulating agent-untreated patients with anemia and NDD-CKD.

Intervention

Eligible patients were randomized 1:1 to receive vadadustat or darbepoetin alfa.

Outcomes

The primary safety end point was time to first MACE. Secondary safety end points included time to first expanded MACE (MACE plus hospitalization for heart failure or thromboembolic event, excluding vascular access thrombosis).

Results

In the non-US/non-Europe region, there was a higher proportion of patients with baseline estimated glomerular filtration rate (eGFR) level of ≤10 mL/min/1.73 m² in the vadadustat group [96 (34.7%)] than in the darbepoetin alfa group [66 (24.0%)]. In this region, there were 21 excess MACEs reported in the vadadustat group [78 events (n=276)] versus the darbepoetin alfa [57 events (n=275)], including 13 excess noncardiovascular deaths, largely from kidney failure. Noncardiovascular deaths were concentrated in Brazil and South Africa, which enrolled higher proportions of patients with an eGFR of ≤10 mL/min/1.73 m² and who may not have had access to dialysis.

Limitations

Different regional treatment patterns of patients with NDD-CKD.

Conclusions

The higher MACE rate in the non-US/non-Europe vadadustat group may have been partly because of imbalances in the baseline eGFR level in countries where dialysis was not uniformly available resulting in many kidney-related deaths.

Physiological Age by Artificial Intelligence-Enhanced Electrocardiograms as a Novel Risk Factor of Mortality in Kidney Transplant Candidates

BACKGROUND

Mortality risk assessment before kidney transplantation (KT) is imperfect. An emerging risk factor for death in nontransplant populations is physiological age as determined by the application of artificial intelligence to the electrocardiogram (ECG). The aim of this study was to examine the relationship between ECG age and KT waitlist mortality.

METHODS

We applied a previously developed convolutional neural network to the ECGs of KT candidates evaluated 2014 to 2019 to determine ECG age. We used a Cox proportional hazard model to examine whether ECG age was associated with waitlist mortality.

RESULTS

Of the 2183 patients evaluated, 59.1% were male, 81.4% were white, and 11.4% died during follow-up. Mean ECG age was 59.0 ± 12.0 y and mean chronological age at ECG was 53.3 ± 13.6 y. After adjusting for chronological age, comorbidities, and other characteristics associated with mortality, each increase in ECG age of >10 y than the average ECG age for patients of a similar chronological age was associated with an increase in mortality risk (hazard ratio 3.59 per 10-y increase; 95% confidence interval, 2.06-5.72; P  < 0.0001).

CONCLUSIONS

ECG age is a risk factor for KT waitlist mortality. Determining ECG age through artificial intelligence may help guide risk-benefit assessment when evaluating candidates for KT.

Home dialysis: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

Home dialysis modalities (home hemodialysis [HD] and peritoneal dialysis [PD]) are associated with greater patient autonomy and treatment satisfaction compared with in-center modalities, yet the level of home-dialysis use worldwide is low. Reasons for limited utilization are context-dependent, informed by local resources, dialysis costs, access to healthcare, health system policies, provider bias or preferences, cultural beliefs, individual lifestyle concerns, potential care-partner time, and financial burdens. In May 2021, KDIGO (Kidney Disease: Improving Global Outcomes) convened a controversies conference on home dialysis, focusing on how modality choice and distribution are determined and strategies to expand home-dialysis use. Participants recognized that expanding use of home dialysis within a given health system requires alignment of policy, fiscal resources, organizational structure, provider incentives, and accountability. Clinical outcomes across all dialysis modalities are largely similar, but for specific clinical measures, one modality may have advantages over another. Therefore, choice among available modalities is preference-sensitive, with consideration of quality of life, life goals, clinical characteristics, family or care-partner support, and living environment. Ideally, individuals, their care-partners, and their healthcare teams will employ shared decision-making in assessing initial and subsequent kidney failure treatment options. To meet this goal, iterative, high-quality education and support for healthcare professionals, patients, and care-partners are priorities. Everyone who faces dialysis should have access to home therapy. Facilitating universal access to home dialysis and expanding utilization requires alignment of policy considerations and resources at the dialysis-center level, with clear leadership from informed and motivated clinical teams.

Defining Myocardial Infarction in trials of people receiving hemodialysis: consensus report from the SONG-HD MI Expert Working group

Cardiovascular disease is the leading cause of death in patients receiving hemodialysis. Currently there is no standardized definition of myocardial infarction (MI) for patients receiving hemodialysis. Through an international consensus process MI was established as the core CVD measure for this population in clinical trials. The Standardised Outcomes in Nephrology Group - Hemodialysis (SONG-HD) initiative convened a multidisciplinary, international working group to address the definition of MI in this population.Based on current evidence, the working group recommends using the 4th Universal Definition of MI with specific caveats with regard to the interpretation of "ischemic symptoms" and performing a baseline 12-lead electrocardiogram to facilitate interpretation of acute changes on subsequent tracings. The working group does not recommend obtaining baseline cardiac troponin values, though does recommend obtaining serial cardiac biomarkers in settings where ischemia is suspected. Application of an evidence-based uniform definition should increase the reliability and accuracy of trial results.

Fifty Years of a National Program for the Treatment of Kidney Failure

This Viewpoint examines the first 50 years of the US End-Stage Renal Disease (ESRD) program, including technological updates and continuing challenges to update cost and quality.

Range and Consistency of Cardiovascular Outcomes Reported by Clinical Trials in Kidney Transplant Recipients: A Systematic Review

Cardiovascular disease is a major cause of morbidity and mortality in kidney transplant recipients. Trial evidence to improve cardiovascular outcomes is limited by inconsistent reporting of outcomes, which may also lack patient-relevance. This study aimed to assess the range and consistency of cardiovascular outcomes reported by contemporary trials in kidney transplant recipients.

Methods

A systematic review of all randomized controlled trials involving adult kidney transplant recipients that reported at least 1 cardiovascular outcome from January 2012 to December 2019 was performed, including Embase, MEDLINE, Cochrane, and ClinicalTrials.gov electronic databases. Trial characteristics were extracted and all levels of specification of the cardiovascular outcome measures reported were analyzed (the measure definition, metric' and method of aggregation). Measures assessing a similar aspect of cardiovascular disease were categorized into outcomes.

Results

From 93 eligible trials involving 27 609 participants, 490 outcome measures were identified. The outcome measures were grouped into 38 outcomes. A cardiovascular composite was the most common outcome reported (40 trials, 43%) followed by cardiovascular mortality (42%) and acute coronary syndrome (31%). Cardiovascular composite was also the most heterogeneous outcome with 77 measures reported followed by cardiovascular mortality (n = 58) and inflammatory biomarkers (n = 51). The most common cardiovascular composite outcome components reported were major cardiovascular events (18 trials), stroke unspecified (11 trials), and myocardial infarction unspecified (10 trials).

Conclusions

There is substantial heterogeneity in cardiovascular outcome reporting in kidney transplant trials.

Overall Adverse Event Profile of Vadadustat versus Darbepoetin Alfa for the Treatment of Anemia Associated with Chronic Kidney Disease in Phase 3 Trials

INTRODUCTION

Anemia frequently occurs in chronic kidney disease (CKD), is associated with poor quality of life and cardiovascular outcomes, and its treatment represents a considerable economic burden to the healthcare system. Although effective, the current standard of care for the treatment of anemia in chronic kidney disease patients with erythropoiesis-stimulating agents requires chronic/ongoing injections, making the treatment less accessible or desirable to patients not treated by in-center maintenance hemodialysis. Furthermore, safety concerns, including an increased risk of cardiovascular events and mortality, have emerged from their use in studies targeting hemoglobin concentrations in the normal or near-normal range. The orally active hypoxia-inducible factor prolyl hydroxylase inhibitor vadadustat may offer advantages over erythropoiesis-stimulating agents by correcting anemia via pathways activating endogenous erythropoietin production.

METHODS

To comprehensively analyze the safety profile of vadadustat in patients with dialysis-dependent and non-dialysis-dependent CKD-related anemia, we pooled the safety populations from each of the four trials in the phase 3 clinical program (n = 7,373) and compared the risk of treatment-emergent adverse events (TEAEs) for each treatment arm.

RESULTS

In patients randomized to vadadustat versus darbepoetin alfa, rates of TEAEs (88.9% vs. 89.3%), treatment-emergent serious adverse events (58.0% vs. 59.3%), and TEAEs leading to death (16.1% vs. 16.2%) were similar, as were rates of adverse events of special interest, including cardiovascular-, hepatic-, and neoplasm-related adverse events.

DISCUSSION/CONCLUSION

Among patients with CKD-related anemia treated with vadadustat, we observed similar rates of adverse events relative to those treated with darbepoetin alfa.

Apixaban for Patients With Atrial Fibrillation on Hemodialysis: A Multicenter Randomized Controlled Trial

BACKGROUND

There are no randomized data evaluating the safety or efficacy of apixaban for stroke prevention in patients with end-stage kidney disease on hemodialysis and with atrial fibrillation (AF).

METHODS

The RENAL-AF trial (Renal Hemodialysis Patients Allocated Apixaban Versus Warfarin in Atrial Fibrillation) was a prospective, randomized, open-label, blinded-outcome evaluation (PROBE) of apixaban versus warfarin in patients receiving hemodialysis with AF and a CHA2DS2-VASc score ≥2. Patients were randomly assigned 1:1 to 5 mg of apixaban twice daily (2.5 mg twice daily for patients ≥80 years of age, weight ≤60 kg, or both) or dose-adjusted warfarin. The primary outcome was time to major or clinically relevant nonmajor bleeding. Secondary outcomes included stroke, mortality, and apixaban pharmacokinetics. Pharmacokinetic sampling was day 1, day 3, and month 1.

RESULTS

From January 2017 through January 2019, 154 patients were randomly assigned to apixaban (n=82) or warfarin (n=72). The trial stopped prematurely because of enrollment challenges. Time in therapeutic range (international normalized ratio, 2.0-3.0) for warfarin-treated patients was 44% (interquartile range, 23%-59%). The 1-year rates for major or clinically relevant nonmajor bleeding were 32% and 26% in apixaban and warfarin groups, respectively (hazard ratio, 1.20 [95% CI, 0.63-2.30]), whereas 1-year rates for stroke or systemic embolism were 3.0% and 3.3% in apixaban and warfarin groups, respectively. Death was the most common major event in the apixaban (21 patients [26%]) and warfarin (13 patients [18%]) arms. The pharmacokinetic substudy enrolled the target 50 patients. Median steady-state 12-hour area under the curve was 2475 ng/mL×h (10th to 90th percentiles, 1342-3285) for 5 mg of apixaban twice daily and 1269 ng/mL×h (10th to 90th percentiles, 615-1946) for 2.5 mg of apixaban twice daily. There was substantial overlap between minimum apixaban blood concentration, 12-hour area under the curve, and maximum apixaban blood concentration for patients with and without a major or clinically relevant nonmajor bleeding event.

CONCLUSIONS

There was inadequate power to draw any conclusion regarding rates of major or clinically relevant nonmajor bleeding comparing apixaban and warfarin in patients with AF and end-stage kidney disease on hemodialysis. Clinically relevant bleeding events were ≈10-fold more frequent than stroke or systemic embolism among this population on anticoagulation, highlighting the need for future randomized studies evaluating the risks versus benefits of anticoagulation among patients with AF and end-stage kidney disease on hemodialysis.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02942407.

Association of Bradycardia and Asystole Episodes with Dialytic Parameters: An Analysis of the Monitoring in Dialysis (MiD) Study

Background

Bradycardia and asystole events are common among patients treated with maintenance hemodialysis. However, triggers of these events in patients on maintenance hemodialysis (HD), particularly during the long interdialytic period when these events cluster, are uncertain.

Methods

The Monitoring in Dialysis Study (MiD) enrolled 66 patients on maintenance HD who were implanted with loop recorders and followed for 6 months. We analyzed associations of predialysis laboratory values with clinically significant bradyarrhythmia or asystole (CSBA) during the 12 hours before an HD session. Associations with CSBA were analyzed with mixed-effect models. Adjusted negative binomial mixed-effect regression was used to estimate incidence rate ratios (IRR) for CSBA. We additionally evaluated associations of CSBA at any time during follow-up with time-averaged dialytic and laboratory parameters and associations of peridialytic parameters with occurrence of CSBA from the start of one HD session to the beginning of the next.

Results

There were 551 CSBA that occurred in the last 12 hours of the interdialytic interval preceding 100 HD sessions in 12% of patients and 1475 CSBA events in 23% of patients overall. We did not identify significant associations between dialytic parameters or serum electrolytes and CSBA in the last 12 hours of the interdialytic interval in adjusted analyses. Median time-averaged ultrafiltration rate was significantly higher in individuals without CSBA (9.8 versus 8, P=0.04). Use of dialysate sodium concentrations ≤135 (versus 140) mEq/L was associated with a reduced risk of CSBA from the start of one session to the beginning of next.

Conclusions

Although a few factors had modest associations with CSBA in some analyses, we did not identify any robust associations of modifiable parameters with CSBA in the MiD Study. Further investigation is needed to understand the high rates of arrhythmia in the hemodialysis population.

Association Between Preoperative Hemodialysis Timing and Postoperative Mortality in Patients With End-stage Kidney Disease

Importance

For patients with end-stage kidney disease treated with hemodialysis, the optimal timing of hemodialysis prior to elective surgical procedures is unknown.

Objective

To assess whether a longer interval between hemodialysis and subsequent surgery is associated with higher postoperative mortality in patients with end-stage kidney disease treated with hemodialysis.

Design, Setting, and Participants

Retrospective cohort study of 1 147 846 procedures among 346 828 Medicare beneficiaries with end-stage kidney disease treated with hemodialysis who underwent surgical procedures between January 1, 2011, and September 30, 2018. Follow-up ended on December 31, 2018.

Exposures

One-, two-, or three-day intervals between the most recent hemodialysis treatment and the surgical procedure. Hemodialysis on the day of the surgical procedure vs no hemodialysis on the day of the surgical procedure.

Main Outcomes and Measures

The primary outcome was 90-day postoperative mortality. The relationship between the dialysis-to-procedure interval and the primary outcome was modeled using a Cox proportional hazards model.

Results

Of the 1 147 846 surgical procedures among 346 828 patients (median age, 65 years [IQR, 56-73 years]; 495 126 procedures [43.1%] in female patients), 750 163 (65.4%) were performed when the last hemodialysis session occurred 1 day prior to surgery, 285 939 (24.9%) when the last hemodialysis session occurred 2 days prior to surgery, and 111 744 (9.7%) when the last hemodialysis session occurred 3 days prior to surgery. Hemodialysis was also performed on the day of surgery for 193 277 procedures (16.8%). Ninety-day postoperative mortality occurred after 34 944 procedures (3.0%). Longer intervals between the last hemodialysis session and surgery were significantly associated with higher risk of 90-day mortality in a dose-dependent manner (2 days vs 1 day: absolute risk, 4.7% vs 4.2%, absolute risk difference, 0.6% [95% CI, 0.4% to 0.8%], adjusted hazard ratio [HR], 1.14 [95% CI, 1.10 to 1.18]; 3 days vs 1 day: absolute risk, 5.2% vs 4.2%, absolute risk difference, 1.0% [95% CI, 0.8% to 1.2%], adjusted HR, 1.25 [95% CI, 1.19 to 1.31]; and 3 days vs 2 days: absolute risk, 5.2% vs 4.7%, absolute risk difference, 0.4% [95% CI, 0.2% to 0.6%], adjusted HR, 1.09 [95% CI, 1.04 to 1.13]). Undergoing hemodialysis on the same day as surgery was associated with a significantly lower hazard of mortality vs no same-day hemodialysis (absolute risk, 4.0% for same-day hemodialysis vs 4.5% for no same-day hemodialysis; absolute risk difference, -0.5% [95% CI, -0.7% to -0.3%]; adjusted HR, 0.88 [95% CI, 0.84-0.91]). In the analyses that evaluated the interaction between the hemodialysis-to-procedure interval and same-day hemodialysis, undergoing hemodialysis on the day of the procedure significantly attenuated the risk associated with a longer hemodialysis-to-procedure interval (P<.001 for interaction).

Conclusions and Relevance

Among Medicare beneficiaries with end-stage kidney disease, longer intervals between hemodialysis and surgery were significantly associated with higher risk of postoperative mortality, mainly among those who did not receive hemodialysis on the day of surgery. However, the magnitude of the absolute risk differences was small, and the findings are susceptible to residual confounding.

A Comparison of US Medicare Expenditures for Hemodialysis and Peritoneal Dialysis

BACKGROUND

Observations that peritoneal dialysis (PD) may be an effective, lower-cost alternative to hemodialysis for the treatment of ESKD have led to policies encouraging PD and subsequent increases in its use in the United States.

METHODS

In a retrospective cohort analysis of Medicare beneficiaries who started dialysis between 2008 and 2015, we ascertained average annual expenditures (for up to 3 years after initiation of dialysis) for patients ≥67 years receiving in-center hemodialysis or PD. We also determined whether differences in Medicare expenditures across dialysis modalities persisted as more patients were placed on PD. We used propensity scores to match 8305 patients initiating PD with 8305 similar patients initiating hemodialysis.

RESULTS

Overall average expenditures were US$108,656 (2017) for hemodialysis and US$91,716 for PD (proportionate difference, 1.11; 95% confidence interval [CI], 1.09 to 1.13). This difference did not change over time (P for time interaction term=0.14). Hemodialysis had higher estimated intravenous (iv) dialysis drug costs (1.69; 95% CI, 1.64 to 1.73), rehabilitation expenditures (1.35; 95% CI, 1.26 to 1.45), and other nondialysis expenditures (1.34; 95% CI, 1.30 to 1.37). Over time, initial differences in total dialysis expenditures disappeared and differences in iv dialysis drug utilization narrowed as nondialysis expenditures diverged. Estimated iv drug costs declined by US$2900 per patient-year in hemodialysis between 2008 and 2014 versus US$900 per patient-year in PD.

CONCLUSIONS

From the perspective of the Medicare program, savings associated with PD in patients ≥67 years have remained unchanged, despite rapid growth in the use of this dialysis modality. Total dialysis expenditures for the two modalities converged over time, whereas nondialysis expenditures diverged.

Azithromycin use increases the risk of sudden cardiac death in patients with hemodialysis-dependent kidney failure

Azithromycin is an antibiotic with QT-prolonging potential commonly prescribed to individuals receiving hemodialysis. Hemodialysis patients have a high prevalence of clinical conditions, such as structural heart disease, that can enhance the pro-arrhythmic effects azithromycin, but were excluded from prior investigations evaluating the cardiac safety of azithromycin. Using data from the United States Renal Data System (2007-2017), we conducted two cohort studies to examine the cardiac safety of azithromycin relative to amoxicillin-based antibiotics (amoxicillin, amoxicillin/clavulanic acid) and levofloxacin (a fluoroquinolone antibiotic known to prolong the QT-interval) in the hemodialysis population. The primary outcome was five-day sudden cardiac death. Using inverse probability of treatment weighted survival models, we estimated hazard ratios, risk differences, and 95% confidence intervals. The azithromycin vs. amoxicillin-based antibiotic cohort included 282,899 patients and 725,431 treatment episodes (381,306 azithromycin and 344,125 amoxicillin-based episodes). Azithromycin vs. amoxicillin-based antibiotic treatment was associated with higher relative and absolute risks of sudden cardiac death, weighted hazard ratio of 1.70 (95% Confidence Interval, 1.36 to 2.11) and weighted risk difference per 100,000 treatment episodes of 25.0 (15.5 to 36.5). The azithromycin vs. levofloxacin cohort included 245,143 patients and 554,557 treatment episodes (387,382 azithromycin and 167,175 levofloxacin episodes). Azithromycin vs. levofloxacin treatment was associated with lower relative and absolute risks of sudden cardiac death, weighted hazard ratio of 0.79 (0.64 to 0.96) and weighted risk difference per 100,000 treatment episodes of -18.9 (-35.5 to -3.8). Thus, when selecting among azithromycin, levofloxacin, and amoxicillin-based antibiotics, clinicians should weigh the relative antimicrobial benefits of these drugs against their potential cardiac risks.

[Nomenclature for kidney function and kidney diseases - Improving assessment and prognosis through precision and comprehensibility]

Nierenkrankheiten stellen ein zunehmendes Gesundheitsproblem dar, dessen Eindämmung eine effektive Kommunikation zwischen den an Erfassung, Diagnostik und Therapie Beteiligten sowie den betroffenen Patientinnen und Patienten erfordert. Die Nomenklatur für Nierenfunktion und Nierenkrankheiten ist jedoch bislang nicht einheitlich. Die internationale, gemeinnützige Organisation Kidney Disease: Improving Global Outcomes (KDIGO) hat deshalb 2019 in einem Konsensus-Prozess ein englischsprachiges Glossar entwickelt, um die Begriffe zur Beschreibung von Nierenfunktion, Nierenstruktur und Nierenkrankheiten zu vereinheitlichen. Leitprinzipien bei der Entwicklung dieser Nomenklatur waren (1) Präzision, (2) Patientenzentrierung und (3) Konsistenz mit bisherigen KDIGO-Leitlinien. Das vorliegende Positionspapier beinhaltet eine deutsche Übersetzung dieses Glossars, die im Auftrag der nephrologischen Fachgesellschaften in Deutschland, Österreich und der Schweiz entwickelt wurde.

Association between cause of kidney failure and fracture incidence in a national US dialysis population cohort study

Background

Whether fracture rates, overall and by fracture site, vary by cause of kidney failure in patients receiving dialysis is unknown.

Methods

Using the US Renal Data System, we compared fracture rates across seven causes of kidney failure in patients who started dialysis between 1997 and 2014. We computed unadjusted and multivariable adjusted proportional sub-distribution hazard models, with fracture events (overall, and by site) as the outcome and immunoglobulin A nephropathy as the reference group. Kidney transplantation and death were competing events.

Results

Among 491 496 individuals, with a median follow-up of 2.0 (25%, 75% range 0.9–3.9) years, 62 954 (12.8%) experienced at least one fracture. Patients with diabetic nephropathy, vasculitis or autosomal polycystic kidney disease (ADPKD) had the highest (50, 46 and 40 per 1000 person-years, respectively), and patient with lupus nephritis had the lowest (20 per 1000 person-years) fracture rates. After multivariable adjustment, diabetic nephropathy [hazard ratio (HR) 1.43, 95% confidence interval 1.33–1.53], ADPKD (HR 1.37, 1.26–1.48), vasculitis (HR 1.22, 1.09–1.34), membranous nephropathy (HR 1.16, 1.02–1.30) and focal segmental glomerulosclerosis (FSGS) (HR 1.13, 1.02–1.24) were associated with a significantly higher, and lupus nephritis with a significantly lower (HR 0.85, 0.71–0.98) fracture hazard. The hazards for upper extremity and lower leg fractures were significantly higher in diabetic nephropathy, ADPKD, FSGS and membranous nephropathy, while the hazard for vertebral fracture was significantly higher in vasculitis. Our findings were limited by the lack of data on medication use and whether fractures were traumatic or non-traumatic, among other factors.

Conclusions

Fracture risk, overall and by fracture site, varies by cause of end-stage kidney disease. Future work to determine underlying pathogenic mechanisms contributing to differential risks might inform more tailored treatment strategies. Our study was limited by lack of data regarding numerous potential confounders or mediators including medications and measures or bone biomarkers.

Erythropoietic effects of vadadustat in patients with anemia associated with chronic kidney disease

Patients with chronic kidney disease (CKD) develop anemia largely because of inappropriately low erythropoietin (EPO) production and insufficient iron available to erythroid precursors. In four phase 3, randomized, open-label, clinical trials in dialysis-dependent and non-dialysis-dependent patients with CKD and anemia, the hypoxia-inducible factor prolyl hydroxylase inhibitor, vadadustat, was noninferior to the erythropoiesis-stimulating agent, darbepoetin alfa, in increasing and maintaining target hemoglobin concentrations. In these trials, vadadustat increased the concentrations of serum EPO, the numbers of circulating erythrocytes, and the numbers of circulating reticulocytes. Achieved hemoglobin concentrations were similar in patients treated with either vadadustat or darbepoetin alfa, but compared with patients receiving darbepoetin alfa, those receiving vadadustat had erythrocytes with increased mean corpuscular volume and mean corpuscular hemoglobin, while the red cell distribution width was decreased. Increased serum transferrin concentrations, as measured by total iron-binding capacity, combined with stable serum iron concentrations, resulted in decreased transferrin saturation in patients randomized to vadadustat compared with patients randomized to darbepoetin alfa. The decreases in transferrin saturation were associated with relatively greater declines in serum hepcidin and ferritin in patients receiving vadadustat compared with those receiving darbepoetin alfa. These results for serum transferrin saturation, hepcidin, ferritin, and erythrocyte indices were consistent with improved iron availability in the patients receiving vadadustat. Thus, overall, vadadustat had beneficial effects on three aspects of erythropoiesis in patients with anemia associated with CKD: increased endogenous EPO production, improved iron availability to erythroid cells, and increased reticulocytes in the circulation.

Natriuretic peptides, extracellular volume, and subclinical cardiovascular changes in chronic kidney disease stages 1-3: a pilot study

Natriuretic peptide levels are elevated in persons with chronic kidney disease (CKD) stages 1-3, but it remains unclear whether this is associated with extracellular volume excess or early cardiovascular changes. We hypothesized that patients with CKD stages 1-3 would have evidence of cardiovascular changes, which would associate with brain natriuretic peptide (BNP), amino-terminal-pro-BNP (NT-pro-BNP), and patient-reported symptoms.Outpatients with CKD stages 1-3 and non-CKD controls were enrolled. Cardiovascular parameters included extracellular water (ECW) normalized to body weight measured using whole-body multifrequency bioimpedance spectroscopy, and total peripheral resistance index (TPRI) and cardiac index measured by impedance cardiography. Dyspnea, fatigue, depression, and quality of life were quantified using questionnaires.Among 21 participants (13 with CKD), median (IQR) BNP was 47.0 (28.0-302.5) vs 19.0 (12.3-92.3) pg/mL, p=0.07, and NT-pro-BNP was 245.0 (52.0-976.8) vs 26.0 (14.5-225.8) pg/mL, p=0.08, in the CKD and control groups, respectively. Those with CKD had higher pulse pressure (79 (66-87) vs 64 (49-67) mm Hg, p=0.046) and TPRI (3721 (3283-4278) vs 2933 (2745-3198) dyn×s/cm5/m2, p=0.01) and lower cardiac index (2.28 (2.08-2.78) vs 3.08 (2.43-3.37) L/min/m2, p=0.02). In the overall cohort, natriuretic peptides correlated with pulse pressure (BNP r=0.59; NT-pro-BNP r=0.58), cardiac index (BNP r=-0.76; NT-pro-BNP r=-0.62), and TPRI (BNP r=0.48), p<0.05 for each, but not with ECW/weight. TPRI and blood pressure correlated moderately with symptoms.Elevated natriuretic peptides may coincide with low cardiac index and elevated peripheral resistance in patients with CKD stages 1-3. The role of these biomarkers to detect subclinical cardiovascular changes needs to be further explored.

The modifying effect of the serum-to-dialysate potassium gradient on the cardiovascular safety of SSRIs in the hemodialysis population: a pharmacoepidemiologic study

BACKGROUND

Hypokalemia is a risk factor for drug-induced QT-prolongation. Larger serum-to-dialysate potassium gradients during hemodialysis may augment the proarrhythmic risks of selective serotonin reuptake inhibitors (SSRIs).

METHODS

We conducted a cohort study using 2007-2017 data from the United States Renal Data System and a large dialysis provider to examine if the serum-to-dialysate potassium gradient modifies SSRI cardiac safety. Using a new-user design, we compared 1-year sudden cardiac death (SCD) risk among hemodialysis patients newly treated with higher (citalopram, escitalopram) vs. lower (fluoxetine, fluvoxamine, paroxetine, sertraline) QT-prolonging potential SSRIs, overall and stratified by baseline potassium gradient (≥4 vs. <4 mEq/L). We used inverse probability of treatment weighted survival models to estimate weighted hazard ratios (HRs) and 95% confidence intervals (CIs), and conducted a confirmatory nested case-control study.

RESULTS

The study included 25,099 patients: 11,107 (44.3%) higher QT-prolonging potential SSRI new-users and 13,992 (55.7%) lower QT-prolonging potential SSRI new-users. Overall, higher vs. lower QT-prolonging potential SSRI use was not associated with SCD, weighted HR of 1.03 (95% CI, 0.86-1.24). However, a greater risk of SCD was associated with higher vs. lower QT-prolonging potential SSRI use among patients with baseline potassium gradients ≥4 mEq/L, but not among those with gradients <4 mEq/L, weighted HR of 2.17 (95% CI, 1.16-4.03) vs. 0.95 (0.78-1.16). Nested case-control analyses yielded analogous results.

CONCLUSIONS

The serum-to-dialysate potassium gradient may modify the association between higher vs. lower QT-prolonging SSRI use and SCD among people receiving hemodialysis. Minimizing the potassium gradient in the setting of QT-prolonging medication use may be warranted.

Proton pump inhibitors may enhance the risk of citalopram- and escitalopram-associated sudden cardiac death among patients receiving hemodialysis

PURPOSE

Polypharmacy is common in the hemodialysis population and increases the likelihood that patients will be exposed to clinically significant drug-drug interactions. Concurrent use of proton pump inhibitors (PPIs) with citalopram or escitalopram may potentiate the QT-prolonging effects of these selective serotonin reuptake inhibitors through pharmacodynamic and/or pharmacokinetic interactions.

METHODS

We conducted a retrospective cohort study using data from the U.S. Renal Data System (2007-2017) and a new-user design to examine the differential risk of sudden cardiac death (SCD) associated with citalopram/escitalopram initiation vs. sertraline initiation in the presence and absence of PPI use among adults receiving hemodialysis. We studied 72 559 patients:14 983 (21%) citalopram/escitalopram initiators using a PPI; 26 503 (36%) citalopram/escitalopram initiators not using a PPI;10 779 (15%) sertraline initiators using a PPI; and 20 294 (28%) sertraline initiators not using a PPI (referent). The outcome of interest was 1-year SCD. We used inverse probability of treatment weighted survival models to estimate weighted hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Compared with sertraline initiators not using a PPI, citalopram/escitalopram initiators using a PPI had the numerically highest risk of SCD (HR [95% CI] = 1.31 [1.11-1.54]), followed by citalopram/escitalopram initiators not using a PPI (HR [95% CI] = 1.22 [1.06-1.41]). Sertraline initiators using a PPI had a similar risk of SCD compared with those not using a PPI (HR [95% CI] = 1.03 [0.85-1.26]).

CONCLUSIONS

Existing PPI use may elevate the risk of SCD associated with citalopram or escitalopram initiation among hemodialysis patients.

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.

Cost Barriers to More Widespread Use of Peritoneal Dialysis in the United States

The United States Department of Health and Human Services launched the Advancing American Kidney Health Initiative in 2019, which included a goal of transforming dialysis care from an in-center to a largely home-based dialysis program. A substantial motivator for this transition is the potential to reduce costs of ESKD care with peritoneal dialysis. Studies demonstrating that peritoneal dialysis is less costly than in-center hemodialysis have often focused on the perspective of the payer, whereas less consideration has been given to the costs of those who are more directly involved in treatment decision making, including patients, caregivers, physicians, and dialysis facilities. We review comparisons of peritoneal dialysis and in-center hemodialysis costs, focusing on costs incurred by the people and organizations making decisions about dialysis modality, to highlight the financial barriers toward increased adoption of peritoneal dialysis. We specifically address misaligned economic incentives, underappreciated costs for key stakeholders involved in peritoneal dialysis delivery, differences in provider costs, and transition costs. We conclude by offering policy suggestions that include improving data collection to better understand costs in peritoneal dialysis, and sharing potential savings among all stakeholders, to incentivize a transition to peritoneal dialysis.

Updated US Prevalence Estimates for Chronic Kidney Disease Stage and Complications Using the New Race-Free Equation to Estimate Glomerular Filtration Rate

This cross-sectional study investigates US population changes in chronic kidney disease (CKD) G stage and 4 CKD-related complications, comparing the 2021 equation for estimating glomerular filtration rate with the 2009 equation, which included a race coefficient.

Implantable Loop Recorder Monitoring and the Incidence of Previously Unrecognized Atrial Fibrillation in Patients on Hemodialysis

INTRODUCTION

Atrial fibrillation (AF) is common in patients with kidney failure on hemodialysis (KF-HD). We determined both AF incidence and burden in patients with KF-HD using implantable loop recorder (ILR) monitoring.

METHODS

Patients with KF-HD were enrolled and received an ILR. In 6 monitoring months, the incidence of AF events lasting ≥6 minutes was captured. Demographic, clinical, and dialysis characteristics were collected, and associations with incident AF were estimated using negative binomial regression models and expressed as incidence rate ratios and 95% CIs.

RESULTS

We enrolled 66 patients with KF-HD (mean age = 56 years, 70% male); 59 (90%) were without previously diagnosed AF. AF lasting ≥6 minutes was detected in 18 of 59 subjects (31%) without previously diagnosed AF and in 5 of 7 subjects (71%) with a previous AF diagnosis. Among the 23 with detected AF, episodes were present on 16% of patient days. Although 14 of 23 patients (61%) had AF on <5% of monitored days, the average duration of AF episodes was <1 hour in 13 of 23 patients (52%). Among patients with AF ≥6 minutes, 19 of 23 (83%) had a CHA2DS2-VASc score ≥2. When investigating individual HD parameters, higher dialysate calcium (>2.5 vs. 2.5 mEq/l: incidence rate ratio = 0.62; 95% CI, 0.48-0.80) was associated with lower AF risk whereas higher dialysate bicarbonate concentrations (>35 vs. 35 mEq/l: incidence rate ratio = 3.18; 95% CI, 1.13-8.94) were associated with higher AF risk.

CONCLUSION

New AF was detected in approximately one-third of patients with KF-HD. AF affects a substantial proportion of patient days and may be an underappreciated cause of stroke in KF-HD.

Sex Differences in Kidney Transplantation: Austria and the United States, 1978–2018

Background

Systematic analyses about sex differences in wait-listing and kidney transplantation after dialysis initiation are scarce. We aimed at identifying sex-specific disparities along the path of kidney disease treatment, comparing two countries with distinctive health care systems, the US and Austria, over time.

Methods

We analyzed subjects who initiated dialysis from 1979–2018, in observational cohort studies from the US and Austria. We used Cox regression to model male-to-female cause-specific hazard ratios (csHRs, 95% confidence intervals) for transitions along the consecutive states dialysis initiation, wait-listing, kidney transplantation and death, adjusted for age and stratified by country and decade of dialysis initiation.

Results

Among 3,053,206 US and 36,608 Austrian patients starting dialysis, men had higher chances to enter the wait-list, which however decreased over time [male-to-female csHRs for wait-listing, 1978–1987: US 1.94 (1.71, 2.20), AUT 1.61 (1.20, 2.17); 2008–2018: US 1.35 (1.32, 1.38), AUT 1.11 (0.94, 1.32)]. Once wait-listed, the advantage of the men became smaller, but persisted in the US [male-to-female csHR for transplantation after wait-listing, 2008–2018: 1.08 (1.05, 1.11)]. The greatest disparity between men and women occurred in older age groups in both countries [male-to-female csHR for wait-listing after dialysis, adjusted to 75% age quantile, 2008–2018: US 1.83 (1.74, 1.92), AUT 1.48 (1.02, 2.13)]. Male-to-female csHRs for death were close to one, but higher after transplantation than after dialysis.

Conclusions

We found evidence for sex disparities in both countries. Historically, men in the US and Austria had 90%, respectively, 60% higher chances of being wait-listed for kidney transplantation, although these gaps decreased over time. Efforts should be continued to render kidney transplantation equally accessible for both sexes, especially for older women.

Anticoagulation use and the risk of stroke and major bleeding in patients on hemodialysis: From the VIVALDI, a population-based prospective cohort study

BACKGROUND

Evidence supporting the use of anticoagulation for the prevention of stroke and thromboembolism in patients with kidney failure on hemodialysis (HD) and atrial fibrillation (AF) is limited. We prospectively assessed the incidences of stroke and major bleeding, as well as anticoagulation strategies in patients on HD with AF.

METHODS

We recruited 625 prevalent HD patients into a population-based observational cohort study. The primary prospective outcomes were thromboembolic events (stroke, transient ischemic attack, systemic embolism) and major bleeding. Secondary outcomes included a composite of thromboembolic events, major bleeding, and cardiovascular death to determine net clinical harm.

RESULTS

A total of 238 patients (38.1%) had AF, 165 (26.4%) already at baseline and 73 (15.9%) developed AF during a median follow up of 870 days. Forty (6.4%) thromboembolic events and 89 (14.2%) major bleedings occurred. Overall, 256 patients died (41.0%). In AF patients, use of vitamin K antagonists (VKAs) in 61 patients (25.6%) was not significantly associated with reduced risk of the primary thromboembolic outcome (subdistribution hazard ratio [SHR] 1.41 adjusted for age, sex, congestive heart failure, hypertension, stroke/transient ischemic attack/thromboembolism, vascular disease, and diabetes history score and antiplatelet co-medication (95% CI, 0.49-4.07), but with increased risk of major bleeding (SHR: 2.28; 95% CI, 1.09-4.79) compared with AF patients without anticoagulation (N = 139, 58.4%). Use of VKAs was associated with net clinical harm (adjusted SHR: 2.07; 95% CI, 1.25-3.42).

CONCLUSIONS

Although the nonrandomized nature of the study is prone to bias, anticoagulation with VKAs was not associated with decreased thromboembolic risk, but rather with increased risk of major bleeding and may be net harmful to patients with AF on HD.

Kidney Function, Kidney Replacement Therapy, and Mortality in Men and Women

Introduction

Women are more likely to have chronic kidney disease (CKD), compared with men, yet they are less likely to receive dialysis. Whether this sex disparity, which has predominantly been observed in nephrology-referred or CKD-specific cohorts so far, has a biological root cause remains unclear.

Methods

We extracted general population data from the Stockholm CREAtinine Measurements project (SCREAM) (N = 496,097 participants, 45.5% men, 54.5% women). We used Cox regression to model male-to-female cause-specific hazard ratios (csHRs) for the competing events kidney replacement therapy (KRT, by dialysis or transplantation) and pre-KRT death, adjusted for baseline age, baseline kidney function (assessed via estimated glomerular filtration rate [eGFR] and eGFR slope), and comorbidities. Furthermore, we modeled sex-specific all-cause mortality by eGFR, again adjusted for age, eGFR slope, and comorbidities at baseline.

Results

Compared with women, men were significantly more likely to receive KRT (fully adjusted male-to-female csHR for KRT 1.41 [95% CI 1.13–1.76]) but also more likely to experience pre-KRT death (csHR 1.36 [95% CI 1.33–1.38]). Differences between men and women regarding all-cause mortality by eGFR indicated a higher mortality in men at low eGFR values.

Conclusion

Our data show that sex differences in CKD outcomes persist even after controlling for important comorbidities and kidney function at baseline. While future studies with a wider range of biological factors are warranted, these data suggest that nonbiological factors may be more important in explaining existing sex disparities in CKD progression and therapy.

Ultrafiltration rate and incident atrial fibrillation among older individuals initiating hemodialysis

BACKGROUND

Higher ultrafiltration (UF) rates are associated with numerous adverse cardiovascular outcomes among individuals receiving maintenance hemodialysis. We undertook this study to investigate the association of UF rate and incident atrial fibrillation in a large, nationally representative US cohort of incident, older hemodialysis patients.

METHODS

We used the US Renal Data System linked to the records of a large dialysis provider to identify individuals ≥67 years of age initiating hemodialysis between January 2006 and December 2011. We applied an extended Cox model as a function of a time-varying exposure to compute adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the association of delivered UF rate and incident atrial fibrillation.

RESULTS

Among the 15 414 individuals included in the study, 3177 developed atrial fibrillation. In fully adjusted models, a UF rate >13 mL/h/kg (versus ≤13 mL/h/kg) was associated with a higher hazard of incident atrial fibrillation [adjusted HR 1.19 (95% CI 1.07-1.30)]. Analyses using lower UF rate thresholds (≤10 versus >10 mL/h/kg and ≤8 versus >8 mL/h/kg, separately) yielded similar results. Analyses specifying the UF rate as a cubic spline (per 1 mL/h/kg) confirmed an approximately linear dose-response relationship between the UF rate and the risk of incident atrial fibrillation: risk began at UF rates of ~6 mL/h/kg and the magnitude of this risk flattened, but remained elevated, at rates ≥9 mL/h/kg.

CONCLUSION

In this observational study of older individuals initiating hemodialysis, higher UF rates were associated with higher incidences of atrial fibrillation.

Global Phase 3 programme of vadadustat for treatment of anaemia of chronic kidney disease: rationale, study design and baseline characteristics of dialysis-dependent patients in the INNO2VATE trials

Background

Erythropoiesis-stimulating agents (ESAs) are currently the mainstay of treatment for anaemia of chronic kidney disease (CKD). Vadadustat is an investigational oral hypoxia-inducible factor prolyl-hydroxylase inhibitor that stimulates endogenous erythropoietin formation. The INNO₂VATE programme comprises two studies designed to evaluate the safety and efficacy of vadadustat versus the ESA darbepoetin alfa in ameliorating anaemia in patients with dialysis-dependent CKD (DD-CKD). Here we describe the trial design along with patient demographics and baseline characteristics.

Methods

Two Phase 3, open-label, sponsor-blind, active-controlled trials enrolled adults with anaemia of CKD who recently initiated dialysis and had limited ESA exposure (incident DD-CKD trial) or were receiving maintenance dialysis with ESA treatment (prevalent DD-CKD trial). Study periods include correction/conversion (Weeks 0–23), maintenance (Weeks 24–52), long-term treatment (Weeks 53 to end of treatment) and safety follow-up. The primary safety endpoint is the time to the first major adverse cardiovascular event and the primary efficacy endpoint is the change in haemoglobin (baseline to Weeks 24–36).

Results

A total of 369 and 3554 patients were randomized in the incident DD-CKD and prevalent DD-CKD trials, respectively. Demographics and baseline characteristics were similar among patients in both trials and comparable to those typically observed in DD-CKD.

Conclusions

The two INNO₂VATE trials will provide important information on the safety and efficacy of a novel approach for anaemia management in a diverse DD-CKD population. Demographics and baseline characteristics of enrolled patients suggest that study results will be representative for a large proportion of the DD-CKD population.

Mortality, Kidney Failure, and Hospitalization Among Medicare Beneficiaries With CKD and Pulmonary Hypertension

RATIONALE & OBJECTIVE

Pulmonary hypertension (PH) is highly prevalent among patients with chronic kidney disease (CKD) not requiring kidney replacement therapy. We studied the associations of PH with mortality, kidney failure, as well as cardiovascular (CV) and non-CV hospitalization among Medicare beneficiaries with a CKD diagnosis.

STUDY DESIGN

Retrospective, observational study using a matched cohort design.

SETTING & PARTICIPANTS

Patients with PH (based on 2 claims within 2 years) and patients without PH matched on CKD stage from the Medicare 5% CKD sample (1996-2016).

PREDICTOR

Presence of pulmonary hypertension.

OUTCOME

Mortality, kidney failure, and all-cause, CV, and non-CV hospitalization.

ANALYTICAL APPROACH

Cox proportional hazards models to assess the association between PH and mortality, adjusting for age, sex, race, and comorbidities. Death was considered as a competing event in Fine-Gray models to assess the association between PH and kidney failure. Negative binomial model was used to evaluate the relationship between PH and all-cause, CV, and non-CV hospitalizations.

RESULTS

30,052 patients with PH and CKD and 150,260 CKD stage-matched patients without diagnosed PH were studied. The median age of the study population was 80.7 years, 57.8% were women, and 10.3% were African Americans. The presence of PH was associated with an increased risk of mortality after 1 (HR, 2.87 [95% CI, 2.79-2.95]), 2-3 (HR, 1.56 [95% CI, 1.51-1.61]), and 4-5 (HR, 1.47 [95% CI, 1.40-1.53]) years of follow-up, and a higher risk of all-cause, CV, and non-CV hospitalization during the same period. PH was also associated with kidney failure in after 1 and 2-3 years but not after 4-5 years of follow-up evaluation. Patients with PH also experienced higher rates of acute kidney injury (AKI), and AKI requiring dialysis support within 30 and 90 days of AKI.

LIMITATIONS

Reliance on billing codes and lack of echocardiogram or right heart catheterization data CONCLUSIONS: Among older Medicare beneficiaries with a CKD diagnosis not requiring kidney replacement therapy, the presence of PH was associated with an increased risk of mortality, kidney failure, and hospitalization. Understanding of the mechanism of these associations, especially the increased risk of kidney failure, requires further study.

Analysis of Respiratory Fluoroquinolones and the Risk of Sudden Cardiac Death Among Patients Receiving Hemodialysis

Importance

Respiratory fluoroquinolone antibiotics are some of the most common medications with QT interval-prolonging potential prescribed to patients with hemodialysis-dependent kidney failure-individuals who have a very high risk of sudden cardiac death (SCD). To date, there have been no large-scale, population-specific studies evaluating the cardiac safety of respiratory fluoroquinolones in the hemodialysis population.

Objective

To investigate the cardiac safety of respiratory fluoroquinolones among individuals with hemodialysis-dependent kidney failure.

Design, Setting, and Participants

A retrospective cohort study examining safety using an active comparator new-user design was conducted using administrative claims data from a US-wide kidney failure registry from January 1, 2007, to December 31, 2016, including 264 968 Medicare beneficiaries receiving in-center maintenance hemodialysis. Data analysis was performed from January 4 to August 16, 2021.

Exposures

Respiratory fluoroquinolone (levofloxacin or moxifloxacin) vs amoxicillin-based (amoxicillin or amoxicillin with clavulanic acid) antibiotic treatment.

Main Outcomes and Measures

Sudden cardiac death within 5 days of outpatient initiation of a study antibiotic. Inverse probability of treatment-weighted survival models to estimate hazard ratios (HRs), risk differences (RDs), and corresponding 95% CIs. Death due to a cause other than SCD was treated as a competing event. Fracture was considered as a negative control outcome.

Results

The study cohort included 264 968 unique in-center hemodialysis patients and 626 322 study antibiotic treatment episodes: 251 726 respiratory fluoroquinolone treatment episodes (40.2%) and 374 596 amoxicillin-based treatment episodes (59.8%). Of the 264 968 patients, 135 236 (51.0%) were men, and the mean (SD) age was 61 (15) years. Respiratory fluoroquinolone vs amoxicillin-based antibiotic treatment was associated with a higher relative and absolute 5-day risk of SCD (weighted HR, 1.95; 95% CI, 1.57-2.41; and weighted RD per 100 000 treatment episodes, 44.0; 95% CI, 31.0-59.2). Respiratory fluoroquinolone vs amoxicillin-based antibiotic treatment was not associated with the 5-day risk of fracture.

Conclusions and Relevance

In this study, compared with amoxicillin-based antibiotic treatment, respiratory fluoroquinolone treatment was associated with a higher short-term risk of SCD among patients with hemodialysis-dependent kidney failure. This finding suggests that decisions between the use of respiratory fluoroquinolones and amoxicillin-based antibiotics should be individualized, with prescribers considering both the clinical benefits and potential cardiac risks.

Anticoagulation in patients with kidney failure on dialysis: factor XI as a therapeutic target

Chronic kidney disease is present in almost 10% of the world population and is associated with excess mortality and morbidity. Reduced glomerular filtration rate and the presence and extent of proteinuria, key domains of chronic kidney disease, have both been shown to be strong and independent risk factors for cardiovascular disease. Patients with kidney failure requiring dialysis are at highest risk for cardiovascular events (e.g., stroke or myocardial infarction), and of developing chronic cardiovascular conditions, such as heart failure. Despite the high burden of cardiovascular disease, there is a paucity of evidence supporting therapies to reduce this risk. Although long-term anticoagulant treatment has the potential to prevent thromboembolism in persons with kidney failure on dialysis, this possibility remains understudied. The limited data available on anticoagulation in patients with kidney failure has focused on vitamin K antagonists or direct oral anticoagulants that inhibit thrombin or factor (F) Xa. The risk of bleeding is a major concern with these agents. However, FXI is emerging as a potential safer target for new anticoagulants because FXI plays a greater part in thrombosis than in hemostasis. In this article, we (i) explain the rationale for considering anticoagulation therapy in patients with kidney failure to reduce atherothrombotic events, (ii) highlight the limitations of current anticoagulants in this patient population, (iii) explain the potential benefits of FXI inhibitors, and (iv) summarize ongoing studies investigating FXI inhibition in patients with kidney failure on dialysis.

Patient Health Outcomes following Dialysis Facility Closures in the United States

BACKGROUND

Ongoing changes to reimbursement of United States dialysis care may increase the risk of dialysis facility closures. Closures may be particularly detrimental to the health of patients receiving dialysis, who are medically complex and clinically tenuous.

METHODS

We used two separate analytic strategies-one using facility-based matching and the other using propensity score matching-to compare health outcomes of patients receiving in-center hemodialysis at United States facilities that closed with outcomes of similar patients who were unaffected. We used negative binomial and Cox regression models to estimate associations of facility closure with hospitalization and mortality in the subsequent 180 days.

RESULTS

We identified 8386 patients affected by 521 facility closures from January 2001 through April 2014. In the facility-matched model, closures were associated with 9% higher rates of hospitalization (relative rate ratio [RR], 1.09; 95% confidence interval [95% CI], 1.03 to 1.16), yielding an absolute annual rate difference of 1.69 hospital days per patient-year (95% CI, 0.45 to 2.93). Similarly, in a propensity-matched model, closures were associated with 7% higher rates of hospitalization (RR, 1.07; 95% CI, 1.00 to 1.13; P=0.04), yielding an absolute rate difference of 1.08 hospital days per year (95% CI, 0.04 to 2.12). Closures were associated with nonsignificant increases in mortality (hazard ratio [HR], 1.08; 95% CI, 1.00 to 1.18; P=0.05 for the facility-matched comparison; HR, 1.08; 95% CI, 0.99 to 1.17; P=0.08 for the propensity-matched comparison).

CONCLUSIONS

Patients affected by dialysis facility closures experienced increased rates of hospitalization in the subsequent 180 days and may be at increased risk of death. This highlights the need for effective policies that continue to mitigate risk of facility closures.