Faculty Bibliography

Background Coronary revascularization provides important long-term clinical benefits to patients with high-risk presentations of coronary artery disease, including those with chronic kidney disease. The cost-effectiveness of coronary interventions in this setting is not known. Methods and Results We developed a Markov cohort simulation model to assess the cost-effectiveness of percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) in patients with chronic kidney disease who were hospitalized with acute myocardial infarction or unstable angina. Model inputs were primarily drawn from a sample of 14 300 patients identified using the Medicare 20% sample. Survival, quality-adjusted life-years, costs, and cost-effectiveness were projected over a 20-year time horizon. Multivariable models indicated higher 30-day mortality and end-stage renal disease with both PCI and CABG, and higher stroke with CABG, relative to medical therapy. However, the model projected long-term gains of 0.72 quality-adjusted life-years (0.97 life-years) for PCI compared with medical therapy, and 0.93 quality-adjusted life-years (1.32 life-years) for CABG compared with PCI. Incorporation of long-term costs resulted in incremental cost-effectiveness ratios of $65 326 per quality-adjusted life-year gained for PCI versus medical therapy, and $101 565 for CABG versus PCI. Results were robust to changes in input parameters but strongly influenced by the background costs of the population, and the time horizon. Conclusions For patients with chronic kidney disease and high-risk coronary artery disease presentations, PCI and CABG were both associated with markedly increased costs as well as gains in quality-adjusted life expectancy, with incremental cost-effectiveness ratios indicating intermediate value in health economic terms.

Background/UNASSIGNED:There is a paucity of contemporary data examining electrolyte changes during and immediately after hemodialysis (HD), and their relationship with dialysate prescriptions. The present study examines these relationships. Methods/UNASSIGNED:We analyzed patient- (n=66) and HD session-level pre- and post-dialysis laboratory data (n=1,713) over a six-month period from the Monitoring in Dialysis Study. We fit mixed effects regression models to analyze electrolyte, blood urea nitrogen, creatinine, and albumin levels immediately post-HD, accounting for pre-HD and dialysate prescriptions. In a subset of US patients (n=40), 15-minute post-HD and 30-minute post-HD values were available at one session. Predictive models were fit to estimate electrolyte levels immediately post-HD, accounting for pre-HD concentrations and dialysate prescriptions. Results/UNASSIGNED:Serum bicarbonate, calcium, and albumin increased (mean increase 4.9±0.3 mEq/L, 0.7±0.1 mEq/L, and 0.4±0.03 g/dL, respectively), whereas potassium, magnesium, and phosphorus decreased immediately post-HD (mean -1.2±0.1 mEq/L, -0.3±0.03 mEq/L, and -3.0±0.2 mg/dL, respectively). Hypokalemia and hypophosphatemia were present in 40% of and 67% of immediate post-HD samples, respectively. Dynamic changes were observed in electrolyte concentrations at 15- and 30-minutes post-HD, compared to immediately post-HD. Conclusion/UNASSIGNED:We describe the magnitude of post-dialytic changes in serum electrolytes with contemporary HD, reporting a high incidence of electrolyte abnormalities post-HD, and present predictive nomograms relating electrolyte changes immediately post-HD to dialysate prescriptions. Our results may be useful for clinical care and provide insights for future research on dialysate prescriptions.

Canagliflozin slows the progression of chronic kidney disease in patients with type 2 diabetes and induces a reversible acute drop in estimated glomerular filtration rate (eGFR), believed to be a hemodynamic effect. Predictors of the initial drop and its association with long-term eGFR trajectories and safety outcomes are unknown. To assess this, we performed a post-hoc analysis of 4289 participants in the CREDENCE trial with type 2 diabetes and chronic kidney disease equally split into treatment and placebo groups who had eGFR measured at both baseline and week three. The eGFR was categorized at week three as greater than a 10% decline; between 0 and 10% decline; and no decline. Long-term eGFR trajectories and safety outcomes were estimated in each category of acute eGFR change by linear mixed effects models and Cox regression after adjustment for baseline characteristics and medications use. Significantly more participants in the canagliflozin (45%) compared to the placebo (21%) group experienced an acute drop in eGFR over 10%. An over 30% drop occurred infrequently (4% of participants with canagliflozin and 2% with placebo). The odds ratio for a drop in eGFR over 10% with canagliflozin compared to placebo was significant at 3.03 (95% confidence interval 2.65, 3.47). Following the initial drop in eGFR, multivariable adjusted long-term eGFR trajectories, as well as overall and kidney safety profiles, in those treated with canagliflozin were similar across eGFR decline categories. Thus, although acute drops in eGFR over 10% occurred in nearly half of all participants following initiation of canagliflozin, the clinical benefit of canagliflozin was observed regardless. Additionally, safety outcomes were similar among subgroups of acute eGFR drop.

Introduction/UNASSIGNED:Reports from the United States suggest that acute kidney injury (AKI) frequently complicates COVID-19, but understanding of AKI risks and outcomes is incomplete. Additionally, whether kidney outcomes have evolved during the course of the pandemic is unknown. Methods/UNASSIGNED:We used electronic records to identify COVID-19 patients with and without AKI admitted to 3 New York Hospitals between March 2 and August 25, 2020. Outcomes included AKI overall and according to admission week, AKI stage, the requirement for new renal replacement therapy (RRT), mortality and recovery of kidney function. Logistic regression was utilized to assess associations of patient characteristics and outcomes. Results/UNASSIGNED:Out of 4732 admissions 1386 (29.3%) patients had AKI. Among those with AKI, 717 (51.7%) had Stage 1, 132 (9.5%) Stage 2, 537 (38.7%) stage 3, and 237 (17.1%) required RRT initiation. In March 536/1648 (32.5%) of patients developed AKI compared with 15/87 (17.2%) in August (P<0.001 for monthly trend) whereas RRT initiation was required in 6.9% and 0% of admission, in March and August respectively. Mortality was higher with than without AKI (51.6% vs 8.6%) and was 71.9% in individuals requiring RRT. However, most patients with AKI who survived hospitalization (77%) recovered to within 0.3 mg/dL of baseline creatinine. Among those surviving to discharge, 62% discontinued RRT. Conclusions/UNASSIGNED:AKI impacts a high proportion of admitted COVID-19 patients and is associated with high mortality, particularly when RRT is required. AKI incidence appears to be decreasing over time and kidney function frequently recovers in those who survive.

Background/UNASSIGNED:The intestinal microbiome is an appealing target for interventions in ESKD because of its likely contribution to uremic toxicity. Before conducting clinical trials of microbiome-altering treatments, it is necessary to understand the within-person and between-person variability in the composition and function of the gut microbiome in patients with ESKD. Methods/UNASSIGNED:We conducted a multicenter, nonrandomized, crossover feasibility study of patients on maintenance hemodialysis consisting of three phases: pretreatment (8 weeks); treatment, during which the prebiotic, p-inulin, was administered at a dosage of 8 g twice daily (12 weeks); and post-treatment (8 weeks). Stool samples were collected 1-2 times per week and blood was collected weekly for 28 weeks. The gut microbiome was characterized using 16S ribosomal-RNA sequencing and metabolomic profiling. Results/UNASSIGNED:=0.004) and a progressive decrease in prevalence of high intraclass correlations, indicating an increase in intraparticipant microbiome diversity during and after p-inulin treatment. An effect of p-inulin on the metabolomic profile was not evident. Conclusions/UNASSIGNED:The intraparticipant stability of the gut microbiome under no-treatment conditions, the tolerability of p-inulin, the signals of increased diversity of the microbiome with p-inulin treatment, and the willingness of participants to provide stool samples all support the feasibility of a larger trial to investigate interventions targeting the gut microbiome in patients with ESKD. Whether or not p-inulin has sufficient efficacy as an intervention requires evaluation in larger studies. Clinical Trial registry name and registration number/UNASSIGNED:Gut Microbiome and p-Inulin in Hemodialysis, NCT02572882.

BACKGROUND AND OBJECTIVES/OBJECTIVE:The kidney protective effects of renin-angiotensin system inhibitors are greater in people with higher levels of albuminuria at treatment initiation. Whether this applies to sodium-glucose cotransporter 2 (SGLT2) inhibitors is uncertain, particularly in patients with a very high urine albumin-to-creatinine ratio (UACR; ≥3000 mg/g). We examined the association between baseline UACR and the effects of the SGLT2 inhibitor, canagliflozin, on efficacy and safety outcomes in the Canagliflozin and Renal Endpoints in Diabetes with Established Nephropathy Clinical Evaluation (CREDENCE) randomized controlled trial. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS/METHODS:=506). In addition, we examined the effects of canagliflozin on UACR itself, eGFR slope, and the intermediate outcomes of glycated hemoglobin, body weight, and systolic BP. RESULTS:=0.02). Rates of kidney-related adverse events were lower with canagliflozin, with a greater relative reduction in higher UACR categories. CONCLUSIONS:Canagliflozin safely reduces kidney and cardiovascular events in people with type 2 diabetes and severely increased albuminuria. In this population, the relative kidney benefits were consistent over a range of albuminuria levels, with greatest absolute kidney benefit in those with an UACR ≥3000 mg/g. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER/UNASSIGNED:ClinicalTrials.gov: CREDENCE, NCT02065791. PODCAST/UNASSIGNED:This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2021_02_22_CJN15260920_final.mp3.

PURPOSE OF REVIEW/OBJECTIVE:Several nontraditional risk factors have been the focus of research in an attempt to understand the disproportionately high cardiovascular morbidity and mortality in chronic kidney disease (CKD) and end-stage kidney disease (ESKD) populations. One such category of risk factors is cardiovascular autonomic dysfunction. Its true prevalence in the CKD/ESKD population is unknown but existing evidence suggests it is common. Due to lack of standardized diagnostic and treatment options, this condition remains undiagnosed and untreated in many patients. In this review, we discuss current evidence pointing toward the role of autonomic nervous system (ANS) dysfunction in CKD, building off of crucial historical evidence and thereby highlighting the areas in need for future research interest. RECENT FINDINGS/RESULTS:There are several key mediators and pathways leading to cardiovascular autonomic dysfunction in CKD and ESKD. We review studies exploring the mechanisms involved and discuss the current measurement tools and indices to evaluate the ANS and their pitfalls. There is a strong line of evidence establishing the temporal sequence of worsening autonomic function and kidney function and vice versa. Evidence linking ANS dysfunction and arrhythmia, sudden cardiac death, intradialytic hypotension, heart failure and hypertension are discussed. SUMMARY/CONCLUSIONS:There is a need for early recognition and referral of CKD and ESKD patients suspected of cardiovascular ANS dysfunction to prevent the downstream effects described in this review.There are many unknowns in this area and a clear need for further research.

PURPOSE:Limited data are available on venovenous extracorporeal membrane oxygenation (ECMO) in patients with severe hypoxemic respiratory failure from coronavirus disease 2019 (COVID-19). METHODS: < 100). Patients were followed until hospital discharge, death, or a minimum of 60 days. We adjusted for confounding using a multivariable Cox model. RESULTS: < 80 (HR 0.55; 95% CI 0.40-0.77). CONCLUSION:In select patients with severe respiratory failure from COVID-19, ECMO may reduce mortality.

OBJECTIVES/UNASSIGNED:The ideal clinical model to deliver palliative care to patients with advanced kidney disease is currently unknown. Internationally, ambulatory kidney palliative care clinics have emerged with positive outcomes, yet there is limited data from the United States (US). In this exploratory study we report perceptions of a US-based ambulatory kidney palliative care clinic from the perspective of patient and caregiver attendees. The objective of this study was to inform further improvement of our clinical program. METHODS/UNASSIGNED:Semi-structured interviews were conducted to elicit the patient and caregiver experience. Eleven interviews (8 patients with chronic kidney disease stage IV or V and 3 caregivers) were analyzed using qualitative description design. RESULTS/UNASSIGNED:We identified 2 themes: "Communication addressing the emotional and physical aspects of disease" and "Filling gaps in care"; Subthemes include perceived value in symptom management, assistance with coping with disease, engagement in advance care planning, program satisfaction and patient activation. SIGNIFICANCE OF RESULTS/UNASSIGNED:Qualitative analysis showed that attendees of an ambulatory kidney palliative care clinic found the clinic enhanced the management of their kidney disease and provided services that filled current gaps in their care. Shared experiences highlight the significant challenges of life with kidney disease and the possible benefits of palliative care for this population. Further study to determine the optimal model of care for kidney palliative care is needed. Inclusion of the patient and caregiver perspective will be essential in this development.

Importance:Therapies that improve survival in critically ill patients with coronavirus disease 2019 (COVID-19) are needed. Tocilizumab, a monoclonal antibody against the interleukin 6 receptor, may counteract the inflammatory cytokine release syndrome in patients with severe COVID-19 illness. Objective:To test whether tocilizumab decreases mortality in this population. Design, Setting, and Participants:The data for this study were derived from a multicenter cohort study of 4485 adults with COVID-19 admitted to participating intensive care units (ICUs) at 68 hospitals across the US from March 4 to May 10, 2020. Critically ill adults with COVID-19 were categorized according to whether they received or did not receive tocilizumab in the first 2 days of admission to the ICU. Data were collected retrospectively until June 12, 2020. A Cox regression model with inverse probability weighting was used to adjust for confounding. Exposures:Treatment with tocilizumab in the first 2 days of ICU admission. Main Outcomes and Measures:Time to death, compared via hazard ratios (HRs), and 30-day mortality, compared via risk differences. Results:Among the 3924 patients included in the analysis (2464 male [62.8%]; median age, 62 [interquartile range {IQR}, 52-71] years), 433 (11.0%) received tocilizumab in the first 2 days of ICU admission. Patients treated with tocilizumab were younger (median age, 58 [IQR, 48-65] vs 63 [IQR, 52-72] years) and had a higher prevalence of hypoxemia on ICU admission (205 of 433 [47.3%] vs 1322 of 3491 [37.9%] with mechanical ventilation and a ratio of partial pressure of arterial oxygen to fraction of inspired oxygen of <200 mm Hg) than patients not treated with tocilizumab. After applying inverse probability weighting, baseline and severity-of-illness characteristics were well balanced between groups. A total of 1544 patients (39.3%) died, including 125 (28.9%) treated with tocilizumab and 1419 (40.6%) not treated with tocilizumab. In the primary analysis, during a median follow-up of 27 (IQR, 14-37) days, patients treated with tocilizumab had a lower risk of death compared with those not treated with tocilizumab (HR, 0.71; 95% CI, 0.56-0.92). The estimated 30-day mortality was 27.5% (95% CI, 21.2%-33.8%) in the tocilizumab-treated patients and 37.1% (95% CI, 35.5%-38.7%) in the non-tocilizumab-treated patients (risk difference, 9.6%; 95% CI, 3.1%-16.0%). Conclusions and Relevance:Among critically ill patients with COVID-19 in this cohort study, the risk of in-hospital mortality in this study was lower in patients treated with tocilizumab in the first 2 days of ICU admission compared with patients whose treatment did not include early use of tocilizumab. However, the findings may be susceptible to unmeasured confounding, and further research from randomized clinical trials is needed.