Fasting Substrate Concentrations Predict Cardiovascular Outcomes in the CANagliflozin cardioVascular Assessment Study (CANVAS).

OBJECTIVE: To examine whether the circulating substrate mix may be related to the incidence of heart failure (HF) and cardiovascular (CV) mortality and how it is altered by canagliflozin treatment. RESEARCH DESIGN AND METHODS: We measured fasting glucose, free fatty acids (FFA), glycerol, ß-hydroxybutyrate, acetoacetate, lactate, and pyruvate concentrations in 3,581 samples from the CANagliflozin cardioVascular Assessment Study (CANVAS) trial at baseline and at 1 and 2 years after randomization. Results were analyzed by univariate and multivariate Cox proportional hazards models. RESULTS: Patients in the lowest baseline FFA tertile were more often men with a longer duration of type 2 diabetes (T2D), higher urinary albumin excretion, lower HDL-cholesterol levels, higher history of CV disease (CVD), and higher use of statins and insulin. When all seven metabolites were used as predictors, FFA were inversely associated with incident hospitalized HF (hazard ratio [HR] 0.33 [95% CI 0.21-0.55]), while glycerol was a positive predictor (2.21 [1.45-3.35]). In a model further adjusted for 16 potential confounders, including prior HF and CVD and pharmacologic therapies, FFA remained a significant negative predictor. FFA and glycerol also predicted CV mortality (HR 0.53 [95% CI 0.35-0.81] and 1.81 [1.26-2.58], respectively) and all-cause death (0.50 [0.36-0.70] and 1.64 [1.22-2.18]). When added to these models, background insulin therapy was an independent positive predictor of risk of death. Canagliflozin treatment significantly increased plasma FFA and ß-hydroxybutyrate regardless of background antihyperglycemic therapy. CONCLUSIONS: A constitutive metabolic setup consisting of higher lipolysis may be beneficial in delaying or preventing hospitalized HF; a further stimulation of lipolysis by canagliflozin may reinforce this influence.

Effects of canagliflozin on serum potassium in the CANagliflozin cardioVascular Assessment Study (CANVAS) Program.

BACKGROUND: The sodium-glucose cotransporter 2 inhibitor canagliflozin has been shown to reduce the risk of cardiovascular and renal events in patients with Type 2 diabetes mellitus and high risk. Pooled analyses of data from early studies and interim data from the CANagliflozin cardioVascular Assessment Study (CANVAS) suggested that canagliflozin might lead to increases in serum potassium, particularly the 300 mg dose in patients with renal impairment, which is important because high serum potassium is associated with increased cardiovascular and renal risk. We examined the effect of canagliflozin on serum potassium levels and hyperkalemia rates in the completed CANVAS Program. METHODS: The CANVAS Program (n = 10,142) was comprised of two comparable double-blind, randomized, placebo-controlled trials (CANVAS and CANVAS-Renal). Participants received canagliflozin 100 or 300 mg or placebo. Serum potassium measurements were performed in a central laboratory0 and assessed at ∼6-month intervals. RESULTS: In the CANVAS Program, mean potassium levels were generally consistent with canagliflozin and placebo, overall and by baseline estimated glomerular filtration rate (eGFR; ≥60, 45 to<60 and <45 mL/min/1.73 m2). The risk of increased or decreased potassium was similar with canagliflozin and placebo overall and by baseline eGFR (all P-heterogeneity ≥0.56) or use of renin-angiotensin-aldosterone system inhibitors (all P-heterogeneity ≥0.71); levels did not appear different by canagliflozin dose. Hyperkalemia {hazard ratio (HR) [95% confidence interval (CI)] 1.60 (0.92-2.81)} and serious hyperkalemia [HR (95% CI) 0.75 (0.27-2.11)] adverse events were not different across groups. CONCLUSIONS: In the CANVAS Program, there were no meaningful effects of canagliflozin on serum potassium in the overall population or key subgroups. Hyperkalemia adverse events were uncommon and occurred at comparable rates with canagliflozin and placebo.

Current status of health systems financing and oversight for end-stage kidney disease care: a cross-sectional global survey.

OBJECTIVES: The Global Kidney Health Atlas (GKHA) is a multinational, cross-sectional survey designed to assess the current capacity for kidney care across all world regions. The 2017 GKHA involved 125 countries and identified significant gaps in oversight, funding and infrastructure to support care for patients with kidney disease, especially in lower-middle-income countries. Here, we report results from the survey for the second iteration of the GKHA conducted in 2018, which included specific questions about health financing and oversight of end-stage kidney disease (ESKD) care worldwide. SETTING: A cross-sectional global survey. PARTICIPANTS: Key stakeholders from 182 countries were invited to participate. Of those, stakeholders from 160 countries participated and were included. PRIMARY OUTCOMES: Primary outcomes included cost of kidney replacement therapy (KRT), funding for dialysis and transplantation, funding for conservative kidney management, extent of universal health coverage, out-of-pocket costs for KRT, within-country variability in ESKD care delivery and oversight systems for ESKD care. Outcomes were determined from a combination of desk research and input from key stakeholders in participating countries. RESULTS: 160 countries (covering 98% of the world's population) responded to the survey. Economic factors were identified as the top barrier to optimal ESKD care in 99 countries (64%). Full public funding for KRT was more common than for conservative kidney management (43% vs 28%). Among countries that provided at least some public coverage for KRT, 75% covered all citizens. Within-country variation in ESKD care delivery was reported in 40% of countries. Oversight of ESKD care was present in all high-income countries but was absent in 13% of low-income, 3% of lower-middle-income, and 10% of upper-middle-income countries. CONCLUSION: Significant gaps and variability exist in the public funding and oversight of ESKD care in many countries, particularly for those in low-income and lower-middle-income countries.

Hemodialysis Use and Practice Patterns: An International Survey Study.

RATIONALE & OBJECTIVE: Hemodialysis (HD) is the most common form of kidney replacement therapy. This study aimed to examine the use, availability, accessibility, affordability, and quality of HD care worldwide. STUDY DESIGN: A cross-sectional survey. SETTING & PARTICIPANTS: Stakeholders (clinicians, policy makers, and consumer representatives) in 182 countries were convened by the International Society of Nephrology from July to September 2018. OUTCOMES: Use, availability, accessibility, affordability, and quality of HD care. ANALYTICAL APPROACH: Descriptive statistics. RESULTS: Overall, representatives from 160 (88%) countries participated. Median country-specific use of maintenance HD was 298.4 (IQR, 80.5-599.4) per million population (pmp). Global median HD use among incident patients with kidney failure was 98.0 (IQR, 81.5-140.8) pmp and median number of HD centers was 4.5 (IQR, 1.2-9.9) pmp. Adequate HD services (3-4 hours 3 times weekly) were generally available in 27% of low-income countries. Home HD was generally available in 36% of high-income countries. 32% of countries performed monitoring of patient-reported outcomes; 61%, monitoring of small-solute clearance; 60%, monitoring of bone mineral markers; 51%, monitoring of technique survival; and 60%, monitoring of patient survival. At initiation of maintenance dialysis, only 5% of countries used an arteriovenous access in almost all patients. Vascular access education was suboptimal, funding for vascular access procedures was not uniform, and copayments were greater in countries with lower levels of income. Patients in 23% of the low-income countries had to pay >75% of HD costs compared with patients in only 4% of high-income countries. LIMITATIONS: A cross-sectional survey with possibility of response bias, social desirability bias, and limited data collection preventing in-depth analysis. CONCLUSIONS: In summary, findings reveal substantial variations in global HD use, availability, accessibility, quality, and affordability worldwide, with the lowest use evident in low- and lower-middle-income countries.

No evidence of a legacy effect on survival following randomization to extended hours dialysis in the ACTIVE Dialysis trial.

AIM: Extended hours haemodialysis is associated with superior survival to standard hours. However, residual confounding limits the interpretation of this observation. We aimed to determine the effect of a period of extended hours dialysis on long-term survival among participants in the ACTIVE Dialysis trial. METHODS: Two-hundred maintenance haemodialysis recipients were randomized to extended hours dialysis (median 24 h/wk) or standard hours dialysis (median 12 h/wk) for 12 months. Further pre-specified observational follow up occurred at 24, 36 and 60 months. Vital status and modality of renal replacement therapy were ascertained. RESULTS: Over the 5 years, 38 participants died, 30 received a renal transplant, and 6 were lost to follow up. Total weekly dialysis hours did not differ between standard and extended groups during the follow-up period (14.1 hours [95%CI 13.4-14.8] vs 14.8 hours [95%CI 14.1-15.6]; P = .16). There was no difference in all-cause mortality (hazard ratio for extended hours 0.91 [95%CI 0.48-1.72]; P = .77). Similar results were obtained after censoring participants at transplantation, and after adjusting for potential confounding variables. Subgroup analysis did not reveal differences in treatment effect by region, dialysis setting or vintage (P-interaction .51, .54, .12, respectively). CONCLUSION: Twelve months of extended hours dialysis did not improve long-term survival nor affect dialysis hours after the intervention period. An urgent need remains to further define the optimal dialysis intensity across the broad range of dialysis recipients.

Inequities in the global representation of sites participating in large, multicentre dialysis trials: a systematic review.

BACKGROUND: The number of dialysis recipients is growing worldwide, making it important that the full range of patient populations are represented in randomised trials. As trial recruitment has not previously been examined at a global level, we compared the location of trial sites recruiting to large multicentre randomised controlled trials (RCTs) in dialysis to the global distribution of dialysis recipients. METHODS: A systematic review (2007-2016) was conducted to identify RCTs enrolling ≥100 dialysis patients from ≥2 sites. The number and location of sites were extracted from manuscripts and trial registration. The proportion of sites from each International Society of Nephrology global region was divided by the proportion of the global dialysis population in that region to determine a 'representation index' (RI), where 1.0 indicated that the number of sites was proportionate to the number of dialysis recipients in that region. RESULTS: We identified 180 RCTs, recruiting from 6172 sites in 54 countries. Eastern and Central Europe had the highest RI at 2.45. Other well-represented regions were Western Europe (2.20), North America (2.06), and Russia and newly independent states (1.36). Africa had the lowest RI at 0.05, followed by South Asia (0.08), Latin America (0.15), Middle East (0.27), North-East Asia (0.41), and South-East Asia and Oceania (0.62). CONCLUSIONS: Regions of the world with growing numbers of dialysis patients are poorly represented in large, multicentre RCTs. Efforts to boost trial participation in these regions are required to ensure that generalisable and relevant information is available to local healthcare providers.

Acute Increases in Serum Creatinine After Starting Angiotensin-Converting Enzyme Inhibitor-Based Therapy and Effects of its Continuation on Major Clinical Outcomes in Type 2 Diabetes Mellitus.

Discontinuation of angiotensin-converting enzyme (ACE) inhibitor is recommended if patients experience ≥30% acute increase in serum creatinine after starting this therapy. However, the long-term effects of its continuation or discontinuation on major clinical outcomes after increases in serum creatinine are unclear. In the ADVANCE trial (Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation), 11 140 diabetes mellitus patients were randomly assigned to perindopril-indapamide or placebo after a 6-week active run-in period. The current study included 11 066 participants with 2 serum creatinine measurements recorded before and during the active run-in period (3 weeks apart). Acute increase in creatinine was determined using these 2 measurements and classified into 4 groups: increases in serum creatinine of <10%, 10% to 19%, 20% to 29%, and ≥30%. The primary study outcome was the composite of major macrovascular events, new or worsening nephropathy, and all-cause mortality. An acute increase in serum creatinine was associated with an elevated risk of the primary outcome ( P for trend <0.001). The hazard ratios were 1.11 (95% CI, 0.97-1.28) for those with an increase of 10% to 19%, 1.34 (1.07-1.66) for 20% to 29%, and 1.44 (1.15-1.81) for ≥30%, compared with <10%. However, there was no evidence of heterogeneity in the benefit of randomized treatment effects on the outcome across subgroups defined by acute serum creatinine increase ( P for heterogeneity=0.94). Acute increases in serum creatinine after starting perindopril-indapamide were associated with greater risks of subsequent major clinical outcomes. However, the continuation of angiotensin-converting enzyme inhibitor-based therapy reduced the long-term risk of major clinical outcomes, irrespective of acute increase in creatinine. Clinical Trial Registration- URL: http://www.clinicaltrials.gov . Unique identifier: NCT00145925.

Canagliflozin for Primary and Secondary Prevention of Cardiovascular Events: Results From the CANVAS Program (Canagliflozin Cardiovascular Assessment Study).

BACKGROUND: Canagliflozin is a sodium glucose cotransporter 2 inhibitor that significantly reduces the composite of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke in patients with type 2 diabetes mellitus and elevated cardiovascular risk. The comparative effects among participants with and without a history of cardiovascular disease (secondary versus primary prevention) were prespecified for evaluation. METHODS: The CANVAS Program (Canagliflozin Cardiovascular Assessment Study) randomly assigned 10 142 participants with type 2 diabetes mellitus to canagliflozin or placebo. The primary prevention cohort comprised individuals ≥50 years of age with ≥2 risk factors for cardiovascular events but with no prior cardiovascular event, and the secondary prevention cohort comprised individuals ≥30 years of age with a prior cardiovascular event. The primary end point was a composite of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke. Secondary outcomes included heart failure hospitalization and a renal composite (40% reduction in estimated glomerular filtration rate, renal replacement therapy, or renal death). RESULTS: Primary prevention participants (N=3486; 34%) were younger (63 versus 64 years of age), were more often female (45% versus 31%), and had a longer duration of diabetes mellitus (14 versus 13 years) compared with secondary prevention participants (N=6656; 66%). The primary end point event rate was higher in the secondary prevention group compared with the primary prevention group (36.9 versus 15.7/1000 patient-years, P<0.001). In the total cohort, the primary end point was reduced with canagliflozin compared with placebo (26.9 versus 31.5/1000 patient-years; hazard ratio [HR], 0.86; 95% confidence interval [CI], 0.75-0.97; P<0.001 for noninferiority, P=0.02 for superiority) with no statistical evidence of heterogeneity (interaction P value=0.18) between the primary (HR, 0.98; 95% CI, 0.74-1.30) and secondary prevention (HR, 0.82; 95% CI, 0.72-0.95) cohorts. Renal outcomes (HR, 0.59; 95% CI, 0.44-0.79 versus HR, 0.63; 95% CI, 0.39-1.02; interaction P value=0.73) and heart failure hospitalization (HR, 0.68; 95% CI, 0.51-0.90 versus HR, 0.64; 95% CI, 0.35-1.15; interaction P value=0.91) were similarly reduced in the secondary and primary prevention cohorts, respectively. Lower extremity amputations were similarly increased in the secondary and primary prevention cohorts (HR, 2.07; 95% CI, 1.43-3.00 versus HR, 1.52; 95% CI, 0.70-3.29; interaction P value=0.63). CONCLUSIONS: Patients with type 2 diabetes mellitus and prior cardiovascular events had higher rates of cardiovascular outcomes compared with the primary prevention patients. Canagliflozin reduced cardiovascular and renal outcomes with no statistical evidence of heterogeneity of the treatment effect across the primary and secondary prevention groups. Additional studies will provide further insights into the effects of canagliflozin in these patient populations. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifiers: NCT01032629 and NCT01989754.

Longitudinal Assessment of the Effect of Atrasentan on Thoracic Bioimpedance in Diabetic Nephropathy: A Randomized, Double-Blind, Placebo-Controlled Trial.

BACKGROUND: Fluid retention is a common adverse event in patients who receive endothelin (ET) receptor antagonist therapy, including the highly selective ETA receptor antagonist, atrasentan. OBJECTIVE: We performed longitudinal assessments of thoracic bioimpedance in patients with type 2 diabetes mellitus and nephropathy to determine whether a decrease in bioimpedance accurately reflected fluid retention during treatment with atrasentan. STUDY DESIGN: We conducted a randomized, double-blind, placebo-controlled study in 48 patients with type 2 diabetes mellitus and nephropathy who were receiving stable doses of renin angiotensin system inhibitors and diuretics. METHODS: Patients were randomized 1:1:1 to placebo, atrasentan 0.5 mg, or atrasentan 1.25 mg once daily for 8 weeks. Thoracic bioimpedance, vital signs, clinical exams, and serologies were taken at weeks 1, 2, 4, 6, and 8, with the exception of serum hemoglobin, which was not taken at week 1, and serum brain natriuretic peptide, which was only taken at baseline, week 4, and week 8. RESULTS: Alterations in bioimpedance were more often present in those who received atrasentan than in those who received placebo, though overall differences were not statistically significant. Transient declines in thoracic bioimpedance during the first 2 weeks of atrasentan exposure occurred before or during peak increases in body weight and hemodilution (decreased serum hemoglobin). CONCLUSIONS: We conclude that thoracic bioimpedance did not reflect changes in weight gain or edema with atrasentan treatment in this study. However, the sample size was small, and it may be of interest to explore the use of thoracic bioimpedance in a larger population to understand its potential clinical use in monitoring fluid retention in patients with chronic kidney disease who receive ET receptor antagonists.

Rationale, design and baseline characteristics of the CANagliflozin cardioVascular Assessment Study-Renal (CANVAS-R): A randomized, placebo-controlled trial.

AIMS: The primary aim of the CANagliflozin cardioVascular Assessment Study-Renal (CANVAS-R) is to determine whether the favourable effects of inhibition of the sodium glucose co-transporter 2 (SGLT2) on blood glucose, blood pressure and body weight are accompanied by protection against adverse renal outcomes. MATERIALS AND METHODS: CANVAS-R is a prospective, randomized, double-blind, placebo-controlled trial in patients with type 2 diabetes with a history or high risk of cardiovascular events. Patients were randomly assigned to once-daily placebo or canagliflozin 100 mg (with optional uptitration to 300 mg) for a planned average of 2.5 years of follow-up. The primary outcome is kidney disease progression, defined by class change in albuminuria. The two secondary outcomes are the composite of hospitalized heart failure or cardiovascular death, and cardiovascular death alone. Effects on end-stage renal disease and a range of other outcomes will also be explored. RESULTS: A total of 5812 participants were recruited at 422 sites in 24 countries between January 2014 and May 2015. The mean baseline age was 64 years, mean duration of diabetes was 14 years, mean glycated haemoglobin level was 8.3% and mean body mass index was 32 kg/m2 . Of these participants, 37% were women, 71% had a history of cardiovascular disease, 22.3% had microalbuminuria and 8.7% had macroalbuminuria. The mean baseline estimated glomerular filtration rate was 76 mL/min/1.73 m2 . The study will have at least 90% power ( P = .05) to detect a 22% or greater reduction in the risk of progression of albuminuria. CONCLUSIONS: The trial should define the potential renoprotective effect of canagliflozin and will provide additional important new data about its effects on vascular outcomes, death and kidney failure.

A randomized, placebo-controlled trial of pentoxifylline on erythropoiesis-stimulating agent hyporesponsiveness in anemic patients with CKD: the Handling Erythropoietin Resistance With Oxpentifylline (HERO) trial.

BACKGROUND: Erythropoiesis-stimulating agent (ESA)-hyporesponsive anemia is common in chronic kidney disease (CKD). Pentoxifylline shows promise as a treatment for ESA-hyporesponsive anemia, but has not been rigorously evaluated. STUDY DESIGN: Multicenter, double-blind, randomized, controlled trial. SETTING & PARTICIPANTS: 53 adult patients with CKD stage 4 or 5 (including dialysis) and ESA-hyporesponsive anemia (hemoglobin≤120g/L and ESA resistance index [calculated as weight-adjusted weekly ESA dose in IU/kg/wk divided by hemoglobin concentration in g/L]≥1.0IU/kg/wk/g/L for erythropoietin-treated patients and ≥0.005µg/kg/wk/g/L for darbepoetin-treated patients). INTERVENTIONS: Pentoxifylline (400mg/d; n=26) or matching placebo (control; n=27) for 4 months. PRIMARY OUTCOME: ESA resistance index at 4 months; secondary outcomes: hemoglobin concentration, ESA dose, blood transfusion requirement, serum ferritin level and transferrin saturation, C-reactive protein level, adverse events, quality of life, and health economics. RESULTS: There was no statistically significant difference in ESA resistance index between the pentoxifylline and control groups (adjusted mean difference, -0.39 [95%CI, -0.89 to 0.10] IU/kg/wk/g/L; P=0.1). Pentoxifylline significantly increased hemoglobin concentration relative to the control group (adjusted mean difference, 7.6 [95%CI, 1.7-13.5] g/L; P=0.01). There was no difference in ESA dose between groups (-20.8 [95%CI, -67.2 to 25.7] IU/kg/wk; P=0.4). No differences in blood transfusion requirements, adverse events, or quality of life were observed between groups. Pentoxifylline cost A$88.05 (US $82.94) per person over the trial and produced mean savings in ESA cost of A$1,332 (US $1,255). The overall economic impact over the trial period was a saving of A$1,244 (US $1,172) per person for the pentoxifylline group compared with controls. LIMITATIONS: Sample size smaller than planned due to slow recruitment. CONCLUSIONS: Pentoxifylline did not significantly modify ESA hyporesponsiveness, but increased hemoglobin concentration. Further studies are warranted to determine whether pentoxifylline therapy represents a safe strategy for increasing hemoglobin levels in patients with CKD with ESA-hyporesponsive anemia.

Co-payments for health care: what is their real cost?

Based on the premise that current trends in healthcare spending are unsustainable, the Australian Government has proposed in the recent Budget the introduction of a compulsory $7 co-payment to visit a General Practitioner (GP), alongside increased medication copayments. This paper is based on a recent submission to the Senate Inquiry into the impact of out-of-pocket costs in Australia. It is based on a growing body of evidence highlighting the substantial economic burden faced by individuals and families as a result of out-of-pocket costs for health care and their flow-on effects on healthcare access, outcomes and long-term healthcare costs. It is argued that a compulsory minimum co-payment for GP consultations will exacerbate these burdens and significantly undermine the tenets of universal access in Medicare. Alternative recommendations are provided that may help harness unsustainable health spending while promoting an equitable and fair health system.

Design and participant baseline characteristics of 'A Clinical Trial of IntensiVE Dialysis': the ACTIVE Dialysis Study.

AIMS: Observational reports suggest extended dialysis hours are associated with improved outcomes. These findings are confounded by better prognostic characteristics among people practising extended hours. The aim of this article is to provide an overview of the methods and baseline characteristics for ACTIVE Dialysis Study participants. METHODS: This multicentre, randomized, open-label, blinded endpoint-assessment trial randomized participants receiving maintenance haemodialysis therapy to either extended (≥24 h) or standard (12-18 h) weekly haemodialysis for 12 months. A web-based randomization system used minimization to ensure balanced allocation across regions, dialysis setting and dialysis vintage. The primary outcome is the change in quality of life over 12 months of study treatment assessed by EQ-5D. Secondary outcomes include change in left ventricular mass index assessed by magnetic resonance imaging and safety outcomes including dialysis access events. RESULTS: A total of 200 participants were recruited between 2009 and 2013 from Australia (29.0%), China (62.0%), Canada (5.5%) and New Zealand (3.5%). Participants had a mean age of 52 (± 12) years and 11.5% were dialysing at home, with a mean duration of 13.9 h per week over a median of three sessions. At baseline, 32.5% had a history of cardiovascular disease and 36.5% had diabetes. CONCLUSION: The ACTIVE Dialysis Study has met its planned recruitment target. The participant population are drawn from a range of health service settings in a global context. The study will contribute important evidence on the benefits and harms of extending weekly dialysis hours. The trial is registered at clinicaltrials.gov (NCT00649298).