Shared Decision Making in Health Care Visits for CKD: Patients' Decisional Role Preferences and Experiences.

RATIONALE & OBJECTIVE: Research on shared decision making (SDM) in chronic kidney disease (CKD) has focused almost exclusively on the modality of kidney replacement treatment. We explored what other CKD decisions are recognized by patients, what their preferences and experiences are regarding these decisions, and how decisions are made during their interactions with medical care professionals. STUDY DESIGN: Cross-sectional study. SETTING & PARTICIPANTS: Patients with CKD receiving (outpatient) care in 1 of 2 Dutch hospitals. EXPOSURE: Patients' preferred decisional roles for treatment decisions were measured using the Control Preferences Scale survey administered after a health care visit with medical professionals. OUTCOME: Number of decisions for which patients experienced a decisional role that did or did not match their preferred role. Observed levels of SDM and motivational interviewing in audio recordings of health care visits, measured using the 4-step SDM instrument (4SDM) and Motivational Interviewing Treatment Integrity coding tools. ANALYTICAL APPROACH: The results were characterized using descriptive statistics, including differences in scores between the patients' experienced and preferred decisional roles. RESULTS: According to the survey (n=122) patients with CKD frequently reported decisions regarding planning (112 of 122), medication changes (82 of 122), or lifestyle changes (59 of 122). Of the 357 reported decisions in total, patients preferred that clinicians mostly (125 of 357) or fully (101 of 357) make the decisions. For 116 decisions, they preferred a shared decisional role. For 151 of 357 decisions, the patients' preferences did not match their experiences. Decisions were experienced as "less shared/patient-directed" (76 of 357) or "more shared/patient-directed" (75 of 357) than preferred. Observed SDM in 118 coded decisions was low (median4; range, 0 - 22). Motivational interviewing techniques were rarely used. LIMITATIONS: Potential recall and selection bias, and limited generalizability. CONCLUSIONS: We identified multiple discrepancies between preferred, experienced, and observed SDM in health care visits for CKD. Although patients varied in their preferred decisional role, a considerable number of patients expressed a preference for shared decision making for many decisions. However, SDM behavior during the health care visits was observed infrequently. PLAIN-LANGUAGE SUMMARY: Shared decision making (SDM) may be a valuable approach for common chronic kidney disease (CKD) decisions, but our knowledge is limited. We collected patient surveys after health care visits for CKD. Patients most frequently experienced decisions regarding planning, medication, and lifestyle. Three decisional roles were preferred by comparable numbers of patients: let the clinician alone decide, let the clinician decide for the most part, or "equally share" the decision. Patients' experiences of who made the decision did not always match their preferences. In audio recordings of the health care visits, we observed low levels of SDM behavior. These findings suggest that the preference for "sharing decisions" is often unmet for a large number of patients.

Predicting outcomes in chronic kidney disease: needs and preferences of patients and nephrologists.

INTRODUCTION: Guidelines on chronic kidney disease (CKD) recommend that nephrologists use clinical prediction models (CPMs). However, the actual use of CPMs seems limited in clinical practice. We conducted a national survey study to evaluate: 1) to what extent CPMs are used in Dutch CKD practice, 2) patients' and nephrologists' needs and preferences regarding predictions in CKD, and 3) determinants that may affect the adoption of CPMs in clinical practice. METHODS: We conducted semi-structured interviews with CKD patients to inform the development of two online surveys; one for CKD patients and one for nephrologists. Survey participants were recruited through the Dutch Kidney Patient Association and the Dutch Federation of Nephrology. RESULTS: A total of 126 patients and 50 nephrologists responded to the surveys. Most patients (89%) reported they had discussed predictions with their nephrologists. They most frequently discussed predictions regarded CKD progression: when they were expected to need kidney replacement therapy (KRT) (n = 81), and how rapidly their kidney function was expected to decline (n = 68). Half of the nephrologists (52%) reported to use CPMs in clinical practice, in particular CPMs predicting the risk of cardiovascular disease. Almost all nephrologists (98%) reported discussing expected CKD trajectories with their patients; even those that did not use CPMs (42%). The majority of patients (61%) and nephrologists (84%) chose a CPM predicting when patients would need KRT in the future as the most important prediction. However, a small portion of patients indicated they did not want to be informed on predictions regarding CKD progression at all (10-15%). Nephrologists not using CPMs (42%) reported they did not know CPMs they could use or felt that they had insufficient knowledge regarding CPMs. According to the nephrologists, the most important determinants for the adoption of CPMs in clinical practice were: 1) understandability for patients, 2) integration as standard of care, 3) the clinical relevance. CONCLUSION: Even though the majority of patients in Dutch CKD practice reported discussing predictions with their nephrologists, CPMs are infrequently used for this purpose. Both patients and nephrologists considered a CPM predicting CKD progression most important to discuss. Increasing awareness about existing CPMs that predict CKD progression may result in increased adoption in clinical practice. When using CPMs regarding CKD progression, nephrologists should ask whether patients want to hear predictions beforehand, since individual patients' preferences vary.

Development of an online patient decision aid for kidney failure treatment modality decisions.

BACKGROUND: Patient decision aids (PtDAs) support patients and clinicians in shared decision-making (SDM). Real-world outcome information may improve patients' risk perception, and help patients make decisions congruent with their expectations and values. Our aim was to develop an online PtDA to support kidney failure treatment modality decision-making, that: 1) provides patients with real-world outcome information, and 2) facilitates SDM in clinical practice. METHODS: The International Patient Decision Aids Standards (IPDAS) development process model was complemented with a user-centred and convergent mixed-methods approach. Rapid prototyping was used to develop the PtDA with a multidisciplinary steering group in an iterative process of co-creation. The results of an exploratory evidence review and a needs-assessment among patients, caregivers, and clinicians were used to develop the PtDA. Seven Dutch teaching hospitals and two national Dutch outcome registries provided real-world data on selected outcomes for all kidney failure treatment modalities. Alpha and beta testing were performed to assess the prototype and finalise development. An implementation strategy was developed to guide implementation of the PtDA in clinical practice. RESULTS: The 'Kidney Failure Decision Aid' consists of three components designed to help patients and clinicians engage in SDM: 1) a paper hand-out sheet, 2) an interactive website, and 3) a personal summary sheet. A 'patients-like-me' infographic was developed to visualise survival probabilities for each treatment modality on the website. Other treatment outcomes were incorporated as event rates (e.g. hospitalisation rates) or explained in text (e.g. the flexibility of each treatment modality). No major revisions were needed after alpha and beta testing. During beta testing, some patients ignored the survival probabilities because they considered these too confronting. Nonetheless, patients agreed that every patient has the right to choose whether they want to view this information. Patients and clinicians believed that the PtDA would help patients make informed decisions, and that it would support values- and preferences-based decision-making. Implementation of the PtDA has started in October 2020. CONCLUSIONS: The 'Kidney Failure Decision Aid' was designed to facilitate SDM in clinical practice and contains real-world outcome information on all kidney failure treatment modalities. It is currently being investigated for its effects on SDM in a clinical trial.

High-flow Nasal Cannula therapy: A feasible treatment for vulnerable elderly COVID-19 patients in the wards.

BACKGROUND: Invasive mechanical ventilation is the treatment of choice in COVID-19 patients when hypoxemia persists, despite maximum conventional oxygen administration. Some frail patients with severe hypoxemic respiratory failure are deemed not eligible for invasive mechanical ventilation. OBJECTIVES: To investigate whether High-flow nasal cannula (HFNC) in the wards could serve as a rescue therapy in these frail patients. METHODS: This retrospective cohort study included frail COVID-19 patients admitted to the hospital between March 9th and May 1st 2020. HFNC therapy was started in the wards. The primary endpoint was the survival rate at hospital discharge. RESULTS: Thirty-two patients with a median age of 79.0 years (74.5-83.0) and a Clinical Frailty Score of 4 out of 9 (3-6) were included. Only 6% reported HFNC tolerability issues. The overall survival rate was 25% at hospital discharge. CONCLUSIONS: This study suggests that, when preferred, HFNC in the wards could be a potential rescue therapy for respiratory failure in vulnerable COVID-19 patients.

The effect of natriuretic C-type peptide and its change over time on mortality in patients on haemodialysis or haemodiafiltration.

BACKGROUND: C-type natriuretic peptide (CNP) and its co-product N-terminal proCNP (NTproCNP) have been associated with beneficial effects on the cardiovascular system. In prevalent dialysis patients, however, a relation between NTproCNP and mortality has not yet been investigated. Furthermore, as a middle molecular weight substance, its concentration might be influenced by dialysis modality. METHODS: In a cohort of patients treated with haemodialysis (HD) or haemodiafiltration (HDF), levels of NTproCNP were measured at baseline and 6, 12, 24 and 36 months. The relation between serum NTproCNP and mortality and the relation between the 6-month rate of change of NTproCNP and mortality were analysed using Cox regression models. For the longitudinal analyses, linear mixed models were used. RESULTS: In total, 406 subjects were studied. The median baseline serum NTproCNP was 93 pmol/L and the median follow-up was 2.97 years. No relation between baseline NTproCNP or its rate of change over 6 months and mortality was found. NTproCNP levels remained stable in HD patients, whereas NTproCNP decreased significantly in HDF patients. The relative decline depended on the magnitude of the convection volume. CONCLUSIONS: In our study, levels of NTproCNP appear strongly elevated in prevalent dialysis patients. Second, while NTproCNP remains unaltered in HD patients, its levels decline in individuals treated with HDF, with the decline dependent on the magnitude of the convection volume. Third, NTproCNP is not related to mortality in this population. Thus NTproCNP does not seem to be a useful marker for mortality risk in dialysis patients.

Improvement of Cardiac Function After Roux-en-Y Gastric Bypass in Morbidly Obese Patients Without Cardiac History Measured by Cardiac MRI.

PURPOSE: Metabolic syndrome in patients with morbid obesity causes a higher cardiovascular morbidity, eventually leading to left ventricular hypertrophy and decreased left ventricular ejection fraction (LVEF). Roux-en-Y gastric bypass (RYGB) is considered the gold standard modality for treatment of morbid obesity and might even lead to improved cardiac function. Our objective is to investigate whether cardiac function in patients with morbid obesity improves after RYGB. MATERIALS AND METHODS: In this single center pilot study, 15 patients with an uneventful cardiac history who underwent RYGB were included from May 2015 to March 2016. Cardiac function was measured by cardiac magnetic resonance imaging (CMRI), performed preoperatively and 3, 6, and 12 months postoperative. LVEF and myocardial mass and cardiac output were measured. RESULTS: A total of 13 patients without decreased LVEF preoperative completed follow-up (mean age 37, 48.0 ± 8.8). There was a significant decrease of cardiac output 12 months postoperative (8.3 ± 1.8 preoperative vs. 6.8 ± 1.8 after 12 months, P = 0.001). Average myocardial mass declined by 15.2% (P < 0.001). After correction for body surface area (BSA), this appeared to be non-significant (P = 0.36). There was a significant improvement of LVEF/BSA at 6 and 12 months postoperative (26.2 ± 4.1 preoperative vs. 28.4 ± 3.4 and 29.2 ± 3.6 respectively, both P = 0.002). Additionally, there was a significant improvement of stroke volume/BSA 12 months after surgery (45.8 ± 8.0 vs. 51.9 ± 10.7, P = 0.033). CONCLUSION: RYGB in patients with morbid obesity with uneventful history of cardiac disease leads to improvement of cardiac function.

Connective Tissue Growth Factor Is Related to All-cause Mortality in Hemodialysis Patients and Is Lowered by On-line Hemodiafiltration: Results from the Convective Transport Study.

Connective tissue growth factor (CTGF) plays a key role in the pathogenesis of tissue fibrosis. The aminoterminal fragment of CTGF is a middle molecule that accumulates in chronic kidney disease. The aims of this study are to explore determinants of plasma CTGF in hemodialysis (HD) patients, investigate whether CTGF relates to all-cause mortality in HD patients, and investigate whether online-hemodiafiltration (HDF) lowers CTGF. Data from 404 patients participating in the CONvective TRAnsport STudy (CONTRAST) were analyzed. Patients were randomized to low-flux HD or HDF. Pre-dialysis CTGF was measured by sandwich ELISA at baseline, after six and 12 months. CTGF was inversely related in multivariable analysis to glomerular filtration rate (GFR) (p < 0.001) and positively to cardiovascular disease (CVD) (p = 0.006), dialysis vintage (p < 0.001), interleukin-6 (p < 0.001), beta-2-microglobulin (p = 0.045), polycystic kidney disease (p < 0.001), tubulointerstitial nephritis (p = 0.002), and renal vascular disease (p = 0.041). Patients in the highest quartile had a higher mortality risk compared to those in the lowest quartile (HR 1.7, 95% CI: 1.02-2.88, p = 0.043). HDF lowered CTGF with 4.8% between baseline and six months, whereas during HD, CTGF increased with 4.9% (p < 0.001). In conclusion, in HD patients, CTGF is related to GFR, CVD and underlying renal disease and increased the risk of all-cause mortality. HDF reduces CTGF.

Role of Albumin Assay on Calcium Levels and Prescription of Phosphate Binders in Chronic Hemodialysis Patients.

BACKGROUND/AIMS: In hemodialysis (HD) patients, the bromcresol green (BCG) assay overestimates, whereas the bromcresol purple (BCP) assay underestimates albumin concentration. Since corrected calcium concentrations depend on albumin, the albumin assay may have implications for the management of bone mineral disorders. METHODS: A subset of patients from CONTRAST, a cohort of prevalent HD patients, was analyzed. Bone mineral parameters and prescription of medication were compared between patients in whom albumin was assessed by BCP versus BCG. RESULTS: Albumin was assessed by BCP in 331 patients (9 of 25 centers) and by BCG in 175 patients (16 of 25 centers). Albumin was the lowest in the BCP group (34.5 ± 4.2 vs. 40.3 ± 3.1 g/L; p < 0.0005). Measured calcium levels and the prescription of calcium-based phosphate binders were similar in both groups. Corrected calcium levels, however, were markedly higher in the BCP group (2.45 ± 0.18 vs. 2.33 ± 0.18 mmol/L; p < 0.0005). CONCLUSION: These findings suggest that calcium levels are not corrected for albumin in clinical practice when considering the prescription of calcium-free or calcium-based phosphate-binders in dialysis patients.

Serum sclerostin: relation with mortality and impact of hemodiafiltration.

BACKGROUND: The glycoprotein sclerostin (Scl; 22 kDa), which is involved in bone metabolism, may play a role in vascular calcification in haemodialysis (HD) patients. In the present study, we investigated the relation between serum Scl (sScl) and mortality. The effects of dialysis modality and the magnitude of the convection volume in haemodiafiltration (HDF) on sScl were also investigated. METHODS: In a subset of patients from the CONTRAST study, a randomized controlled trial comparing HDF with HD, sScl was measured at baseline and at intervals of 6, 12, 24 and 36 months. Patients were divided into quartiles, according to their baseline sScl. The relation between time-varying sScl and mortality with a 4-year follow-up period was investigated using crude and adjusted Cox regression models. Linear mixed models were used for longitudinal measurements of sScl. RESULTS: The mean (±standard deviation) age of 396 test subjects was 63.6 (±13.9 years), 61.6% were male and the median follow-up was 2.9 years. Subjects with the highest sScl had a lower mortality risk than those with the lowest concentrations [adjusted hazard ratio 0.51 (95% confidence interval, CI, 0.31-0.86, P = 0.01)]. Stratified models showed a stable sScl in patients treated with HD (Δ +2.9 pmol/L/year, 95% CI -0.5 to +6.3, P = 0.09) and a decreasing concentration in those treated with HDF (Δ -4.5 pmol/L/year, 95% CI -8.0 to -0.9, P = 0.02). The relative change in the latter group was related to the magnitude of the convection volume. CONCLUSIONS: (i) A high sScl is associated with a lower mortality risk in patients with end-stage kidney disease; (ii) treatment with HDF causes sScl to fall; and (iii) the relative decline in patients treated with HDF is dependent on the magnitude of the convection volume.

Comparing Tests Assessing Protein-Energy Wasting: Relation With Quality of Life.

OBJECTIVE: Protein-energy wasting (PEW), a state of decreased bodily protein and energy fuels, is highly prevalent among hemodialysis patients. The best method to determine PEW, however, remains debated. As an independent, negative association between PEW and quality of life (QOL) has been demonstrated, establishing which nutrition-related test correlates best with QOL may help to identify how PEW should preferably be assessed. DESIGN AND METHODS: Data were used from CONTRAST, a cohort of end-stage kidney disease patients. At baseline, Subjective Global Assessment (SGA), Malnutrition Inflammation Score (MIS), Geriatric Nutritional Risk Index, composite score on protein-energy nutritional status, normalized protein nitrogen appearance, body mass index, serum albumin, and serum creatinine were determined. QOL was assessed by the Kidney Disease Quality of Life Short Form 1.3. The present study reports on 2 general and 11 kidney disease-specific QOL scores. Spearman's rho (ρ) was calculated to determine correlations between nutrition-related tests and QOL domains. Twelve months after randomization, a sensitivity analysis was performed to test the robustness of the results. RESULTS: Of 714 patients, 489 representative subjects were available for analysis. All tests correlated with the Physical Component Score, except body mass index. Only SGA and MIS correlated significantly with the Mental Component Score. SGA correlated significantly with 10 of 11 kidney disease-specific QOL domains. The MIS not only correlated significantly with all (11) kidney disease-specific QOL domains but also with higher correlation coefficients. CONCLUSION: Of the 8 investigated nutrition-related tests, only MIS correlates with all QOL domains (13 of 13) with the strongest associations.

Early home-based group education to support informed decision-making among patients with end-stage renal disease: a multi-centre randomized controlled trial.

BACKGROUND: The aim was to test the effectiveness of early home-based group education on knowledge and communication about renal replacement therapy (RRT). METHODS: We conducted a randomized controlled trial using a cross-over design among 80 end-stage renal disease (ESRD) patients. Between T0 and T1 (weeks 1-4) Group 1 received the intervention and Group 2 received standard care. Between T1 and T2 (weeks 5-8) Group 1 received standard care and Group 2 received the intervention. The intervention was a group education session on RRT options held in the patient's home given by social workers. Patients invited members from their social network to attend. Self-report questionnaires were used at T0, T1 and T2 to measure patients' knowledge and communication, and concepts from the Theory of Planned Behaviour such as attitude. Comparable questionnaires were completed pre-post intervention by 229 attendees. Primary RRT was registered up to 2 years post-intervention. Multilevel linear modelling was used to analyse patient data and paired t-tests for attendee data. RESULTS: Statistically significant increases in the primary targets knowledge and communication were found among patients and attendees after receiving the intervention. The intervention also had a significant effect in increasing positive attitude toward living donation and haemodialysis. Of the 80 participants, 49 underwent RRT during follow-up. Of these, 34 underwent a living donor kidney transplant, of which 22 were pre-emptive. CONCLUSIONS: Early home-based group education supports informed decision-making regarding primary RRT for ESRD patients and their social networks and may remove barriers to pre-emptive transplantation.

Serum Magnesium and Sudden Death in European Hemodialysis Patients.

Despite suggestions that higher serum magnesium (Mg) levels are associated with improved outcome, the association with mortality in European hemodialysis (HD) patients has only scarcely been investigated. Furthermore, data on the association between serum Mg and sudden death in this patient group is limited. Therefore, we evaluated Mg in a post-hoc analysis using pooled data from the CONvective TRAnsport STudy (CONTRAST, NCT00205556), a randomized controlled trial (RCT) evaluating the survival risk in dialysis patients on hemodiafiltration (HDF) compared to HD with a mean follow-up of 3.1 years. Serum Mg was measured at baseline and 6, 12, 24 and 36 months thereafter. Cox proportional hazards models, adjusted for confounders using inverse probability weighting, were used to estimate hazard ratios (HRs) of baseline serum Mg on all-cause mortality, cardiovascular mortality, non-cardiovascular mortality and sudden death. A generalized linear mixed model was used to investigate Mg levels over time. Out of 714 randomized patients, a representative subset of 365 (51%) were analyzed in the present study. For every increase in baseline serum Mg of 0.1 mmol/L, the HR for all-cause mortality was 0.85 (95% CI 0.77-94), the HR for cardiovascular mortality 0.73 (95% CI 0.62-0.85) and for sudden death 0.76 (95% CI 0.62-0.93). These findings did not alter after extensive correction for potential confounders, including treatment modality. Importantly, no interaction was found between serum phosphate and serum Mg. Baseline serum Mg was not related to non-cardiovascular mortality. Mg decreased slightly but statistically significant over time (Δ -0.011 mmol/L/year, 95% CI -0.017 to -0.009, p = 0.03). In short, serum Mg has a strong, independent association with all-cause mortality, cardiovascular mortality and sudden death in European HD patients. Serum Mg levels decrease slightly over time.

Eccentric Left Ventricular Hypertrophy and Sudden Death in Patients with End-Stage Kidney Disease.

BACKGROUND/AIMS: Both all-cause and cardiovascular mortality risks are extremely high in patients with end-stage kidney disease (ESKD). Sudden death accounts for approximately one-quarter of all fatal events. Left ventricular hypertrophy (LVH) is a known risk factor for mortality and can be divided in 2 types: concentric and eccentric. This study evaluated possible differences in all-cause mortality, cardiovascular mortality and sudden death between prevalent ESKD patients with concentric and eccentric LVH. METHODS: Participants of the CONvective TRAnsport STudy (CONTRAST) who underwent transthoracic echocardiography (TTE) at baseline were analyzed. In patients with LVH, a relative wall thickness of ≤0.42 was considered eccentric and >0.42 was considered concentric hypertrophy. Cox proportional hazards models, adjusted for potential confounders, were used to calculate hazard ratios (HRs) of patients with eccentric LVH versus patients with concentric LVH for all-cause mortality, cardiovascular mortality and sudden death. RESULTS: TTE was performed in 328 CONTRAST participants. LVH was present in 233 participants (71%), of which 87 (37%) had concentric LVH and 146 (63%) eccentric LVH. The HR for all-cause mortality of eccentric versus concentric LVH was 1.14 (p = 0.52), 1.79 (p = 0.12) for cardiovascular mortality and 4.23 (p = 0.02) for sudden death in crude analyses. Propensity score-corrected HR for sudden death in patients with eccentric LVH versus those with concentric LVH was 5.22 (p = 0.03). CONCLUSIONS: (1) The hazard for all-cause mortality, cardiovascular mortality and sudden death is markedly increased in patients with LVH. (2) The sudden death risk is significantly higher in ESKD patients with eccentric LVH compared to subjects with concentric LVH.

The Effect of Online Hemodiafiltration on Infections: Results from the CONvective TRAnsport STudy.

BACKGROUND: Hemodialysis (HD) patients have a high risk of infections. The uremic milieu has a negative impact on several immune responses. Online hemodiafiltration (HDF) may reduce the risk of infections by ameliorating the uremic milieu through enhanced clearance of middle molecules. Since there are few data on infectious outcomes in HDF, we compared the effects of HDF with low-flux HD on the incidence and type of infections. PATIENTS AND METHODS: We used data of the 714 HD patients (age 64 ±14, 62% men, 25% Diabetes Mellitus, 7% catheters) participating in the CONvective TRAnsport STudy (CONTRAST), a randomized controlled trial evaluating the effect of HDF as compared to low-flux HD. The events were adjudicated by an independent event committee. The risk of infectious events was compared with Cox regression for repeated events and Cox proportional hazard models. The distributions of types of infection were compared between the groups. RESULTS: Thirty one percent of the patients suffered from one or more infections leading to hospitalization during the study (median follow-up 1.96 years). The risk for infections during the entire follow-up did not differ significantly between treatment arms (HDF 198 and HD 169 infections in 800 and 798 person-years respectively, hazard ratio HDF vs. HD 1.09 (0.88-1.34), P = 0.42. No difference was found in the occurrence of the first infectious event (either fatal, non-fatal or type specific). Of all infections, respiratory infections (25% in HDF, 28% in HD) were most common, followed by skin/musculoskeletal infections (21% in HDF, 13% in HD). CONCLUSIONS: HDF as compared to HD did not result in a reduced risk of infections, larger studies are needed to confirm our findings. TRIAL REGISTRATION: ClinicalTrials.gov NCT00205556.

Treatment Time or Convection Volume in HDF: What Drives the Reduced Mortality Risk?

BACKGROUND/AIMS: Treatment time is associated with survival in hemodialysis (HD) patients and with convection volume in hemodiafiltration (HDF) patients. High-volume HDF is associated with improved survival. Therefore, we investigated whether this survival benefit is explained by treatment time. METHODS: Participants were subdivided into four groups: HD and tertiles of convection volume in HDF. Three Cox regression models were fitted to calculate hazard ratios (HRs) for mortality of HDF subgroups versus HD: (1) crude, (2) adjusted for confounders, (3) model 2 plus mean treatment time. As the only difference between the latter models is treatment time, any change in HRs is due to this variable. RESULTS: 114/700 analyzed individuals were treated with high-volume HDF. HRs of high-volume HDF are 0.61, 0.62 and 0.64 in the three models, respectively (p values <0.05). Confidence intervals of models 2 and 3 overlap. CONCLUSION: The survival benefit of high-volume HDF over HD is independent of treatment time.

A Comparison of 8 Nutrition-Related Tests to Predict Mortality in Hemodialysis Patients.

OBJECTIVE: Protein-energy wasting (PEW) describes a state of decreased protein and energy fuels and is highly prevalent in hemodialysis patients. As PEW is associated with mortality, it should be detected accurately and easily. This study investigated which nutrition-related test predicts mortality and morbidity best in hemodialysis patients. DESIGN AND SUBJECTS: Data were used from CONTRAST, a cohort of end-stage kidney disease patients. Subjective Global Assessment (SGA), Malnutrition Inflammation Score (MIS), Geriatric Nutritional Risk Index (GNRI), composite score of Protein-Energy Nutritional Status (cPENS), serum albumin, serum creatinine, body mass index, and normalized protein nitrogen appearance rate were assessed at baseline. End points were all-cause mortality, cardiovascular events, and infection. Discriminative value of every test was assessed with Harrell's C statistic and calibration tested using the Hosmer-Lemeshow goodness-of-fit test. Ultimately, in every test, 4 groups were created to compare (1) hazard ratios (HR; worst vs best group), (2) HR increase per group, and (3) HR of worst group versus other groups. RESULTS: In total, 489 patients were analyzed. Median follow-up was 2.97 years (interquartile range, 1.67-4.47 years). MIS, GNRI, albumin, and creatinine discriminated all-cause mortality equally. SGA, cPENS, body mass index, and normalized protein nitrogen appearance were inferior. cPENS and creatinine were inadequately calibrated. Of the remaining tests, GNRI predicted mortality less when comparing HRs. MIS and albumin predicted mortality equally well. In a subanalysis, these also predicted infection equally well, but MIS predicted cardiovascular events better. CONCLUSION: Of the 8 investigated nutrition-related tests, MIS and albumin predict mortality best in hemodialysis patients. As one has no added value over the other, we conclude that mortality is most easily predicted in hemodialysis patients by serum albumin.

Recurrent FXYD2 p.Gly41Arg mutation in patients with isolated dominant hypomagnesaemia.

BACKGROUND: Magnesium (Mg(2+)) is an essential ion for cell growth, neuroplasticity and muscle contraction. Blood Mg(2+) levels <0.7 mmol/L may cause a heterogeneous clinical phenotype, including muscle cramps and epilepsy and disturbances in K(+) and Ca(2+) homeostasis. Over the last decade, the genetic origin of several familial forms of hypomagnesaemia has been found. In 2000, mutations in FXYD2, encoding the γ-subunit of the Na(+)-K(+)-ATPase, were identified to cause isolated dominant hypomagnesaemia (IDH) in a large Dutch family suffering from hypomagnesaemia, hypocalciuria and chondrocalcinosis. However, no additional patients have been identified since then. METHODS: Here, two families with hypomagnesaemia and hypocalciuria were screened for mutations in the FXYD2 gene. Moreover, the patients were clinically and genetically characterized. RESULTS: We report a p.Gly41Arg FXYD2 mutation in two families with hypomagnesaemia and hypocalciuria. Interestingly, this is the same mutation as was described in the original study. As in the initial family, several patients suffered from muscle cramps, chondrocalcinosis and epilepsy. Haplotype analysis revealed an overlapping haplotype in all families, suggesting a founder effect. CONCLUSIONS: The recurrent p.Gly41Arg FXYD2 mutation in two new families with IDH confirms that FXYD2 mutation causes hypomagnesaemia. Until now, no other FXYD2 mutations have been reported which could indicate that other FXYD2 mutations will not cause hypomagnesaemia or are embryonically lethal.

Treatment policy rather than patient characteristics determines convection volume in online post-dilution hemodiafiltration.

BACKGROUND/AIMS: Sub-analyses of three large trials showed that hemodiafiltration (HDF) patients who achieved the highest convection volumes had the lowest mortality risk. The aims of this study were (1) to identify determinants of convection volume and (2) to assess whether differences exist between patients achieving high and low volumes. METHODS: HDF patients from the CONvective TRAnsport STudy (CONTRAST) with a complete dataset at 6 months (314 out of a total of 358) were included in this post hoc analysis. Determinants of convection volume were identified by regression analysis. RESULTS: Treatment time, blood flow rate, dialysis vintage, serum albumin and hematocrit were independently related. Neither vascular access nor dialyzer characteristics showed any relation with convection volume. Except for some variation in body size, patient characteristics did not differ across tertiles of convection volume. CONCLUSION: Treatment time and blood flow rate are major determinants of convection volume. Hence, its magnitude depends on center policy rather than individualized patient prescription.

Resistance to erythropoiesis stimulating agents in patients treated with online hemodiafiltration and ultrapure low-flux hemodialysis: results from a randomized controlled trial (CONTRAST).

UNLABELLED: Resistance to erythropoiesis stimulating agents (ESA) is common in patients undergoing chronic hemodialysis (HD) treatment. ESA responsiveness might be improved by enhanced clearance of uremic toxins of middle molecular weight, as can be obtained by hemodiafiltration (HDF). In this analysis of the randomized controlled CONvective TRAnsport STudy (CONTRAST; NCT00205556), the effect of online HDF on ESA resistance and iron parameters was studied. This was a pre-specified secondary endpoint of the main trial. A 12 months' analysis of 714 patients randomized to either treatment with online post-dilution HDF or continuation of low-flux HD was performed. Both groups were treated with ultrapure dialysis fluids. ESA resistance, measured every three months, was expressed as the ESA index (weight adjusted weekly ESA dose in daily defined doses [DDD]/hematocrit). The mean ESA index during 12 months was not different between patients treated with HDF or HD (mean difference HDF versus HD over time 0.029 DDD/kg/Hct/week [-0.024 to 0.081]; P = 0.29). Mean transferrin saturation ratio and ferritin levels during the study tended to be lower in patients treated with HDF (-2.52% [-4.72 to -0.31]; P = 0.02 and -49 ng/mL [-103 to 4]; P = 0.06 respectively), although there was a trend for those patients to receive slightly more iron supplementation (7.1 mg/week [-0.4 to 14.5]; P = 0.06). In conclusion, compared to low-flux HD with ultrapure dialysis fluid, treatment with online HDF did not result in a decrease in ESA resistance. TRIAL REGISTRATION: ClinicalTrials.gov NCT00205556.