Returning to haemodialysis after kidney allograft failure: a survival study with propensity score matching.

BACKGROUND: Patients who return to dialysis after kidney allograft failure (KAF) are classically considered to have lower survival rates than their transplant-naïve incident dialysis counterparts. However, this observation in previous comparisons could be due to poor matching between the two populations. METHODS: To compare survival rates between patients who returned to haemodialysis (HD) after KAF versus transplant-naïve incident HD patients, we performed a retrospective study using the EuCliD® database (European Clinical Database) that collects data from Fresenius Medical Care (FMC) outpatient HD facilities in Spain. Propensity score matching (PSM) was performed to homogenize both populations. RESULTS: This study included 5216 patients from 65 different FMC clinics between 2009 and 2014. Naïve incident HD patients were mostly male, older, comorbid and more commonly had catheters as vascular access. During the study follow-up, 3915 patients exited, of whom 1534 died. The mean survival time for the entire cohort was 4.86 years [95% confidence interval (CI) 4.78-4.94]. Univariate Cox analysis indicated higher mortality risk among transplant-naïve incident HD patients [hazard ratio (HR) 1.728; 95% CI 1.35-2.21; P < 0.001). However, this difference was no longer significant after multivariate adjustment. After applying PSM to minimize the bias due to indication issue, we obtained an adjusted population composed of 480 naïve and 240 KAF patients. The results analysing the PSM-adjusted cohort confirmed similar survival in both cohorts (log-rank, 3.34; P = 0.068; HR 1.382; 95% CI 0.97-1.95; P = 0.069). CONCLUSIONS: When comparing properly matched patient groups, patients who return to HD after KAF present similar survival than survival than transplant-naïve incident patients.

Proton Pump Inhibitor Usage and the Risk of Mortality in Hemodialysis Patients.

INTRODUCTION: Long-term inappropriate proton pump inhibitors use (PPIs) is a matter of concern because of the risks associated with their long-term use in older patients with chronic conditions. The risk of PPI treatment in hemodialysis patients remains unexplored. METHODS: We assessed the relationship between the use of PPIs and the risk of death in hemodialysis patients throughout a retrospective multicenter propensity score-matched study. Information about demographic, hemodialysis treatment, laboratory data, and concomitant medication was obtained from the EuCliD database (Fresenius Medical Care). We studied 1776 hemodialysis patients on PPI therapy compared to 466 patients not receiving PPIs. The resulting population comprising 2 groups of 410 matched patients was studied. RESULTS: PPI use was associated with hypomagnesemia (Mg <1.8 mg/dl (0.75 mmol/l); odds ratio [OR] = 2.70, 95% confidence interval [CI] = 1.38-5.27, P < 0.01). The exposure to PPIs in the full patient cohort was identified as an independent predictor for all-cause mortality in both univariate (HR = 3.16, 95% CI = 1.69-5.90, P < 0.01) and multivariate (HR = 2.70, 95% CI = 1.38-5.27, P < 0.01) Cox regression models. Moreover PPI use was identified as a predictor of CV mortality (HR = 1.51, 95% CI = 1.05-2.20, P = 0.03) Of the 820 patients matched throughout the propensity score analysis, the hazard ratios for all-cause mortality (HR = 1.412, 95% CI = 1.04-1.93, P = 0.03) and CV mortality (HR = 1.67, 95% CI = 1.03-2.71, P = 0.04) were higher among patients on PPIs versus those not on PPIs. CONCLUSION: The study data suggest that the PPI treatment should be regularly monitored and prescribed only when indicated.

Increased mortality in haemodialysis patients administered high doses of erythropoiesis-stimulating agents: a propensity score-matched analysis.

Background: Erythropoiesis-stimulating agents (ESAs) are widely used to treat anaemia in patients with chronic kidney disease. The issue of ESA safety has been raised in multiple studies, with correlates derived for elevated cancer incidence and mortality. Whether these associations are related to ESA dose or the typology of the patient remains obscure. Methods: A multicentre, observational retrospective propensity score-matched study was designed to analyse the effects of weekly ESA dose in 1679 incident haemodialysis (HD) patients. ESA administration was according to standard medical practice. Patients were grouped as quintiles, according to ESA dose, in order to compare mortality and hospitalization data. Using propensity score matching (PSM), we defined two groups of 324 patients receiving weekly threshold ESA doses of either > or ≤8000 IU. Results: Kaplan-Meier survival curves indicated significant increases in the risk of mortality in patients administered with high doses of ESAs (>8127.4 IU/week). Multivariate Cox models identified a high ESA dose as an independent predictor for all-cause and cardiovascular (CV) mortality. Moreover, logistic regression models identified high ESA doses as an independent predictor for all-cause, CV and infectious hospitalization. PSM analyses confirmed that weekly ESA doses of >8000 IU constitute an independent predictor of all-cause mortality and hospitalization, even though the adjusted cohort displayed the same demographic features, inflammatory profile, clinical HD parameters and haemoglobin levels. Conclusions: Our data suggest that ESA doses of >8000 IU/week are associated with an increased risk of all-cause mortality and hospitalization in HD patients.

Hemodiafiltration Reduces All-Cause and Cardiovascular Mortality in Incident Hemodialysis Patients: A Propensity-Matched Cohort Study.

BACKGROUND: The majority of studies suggesting that online hemodiafiltration reduces the risk of mortality compared to hemodialysis (HD) have been performed in dialysis-prevalent populations. In this report, we conducted an epidemiologic study of mortality in incident dialysis patients, comparing post-dilution online hemodiafiltration and high-flux HD, with propensity score matching (PSM) used to correct indication bias. METHODS: Our study cohort comprised 3,075 incident dialysis patients treated in 64 Spanish Fresenius Medical Care clinics between January 2009 and December 2012. The primary outcome of this study was to investigate the impact of the type of renal replacement on all-cause mortality. An analysis of cardiovascular mortality was defined as the secondary outcome. To achieve these objectives, patients were followed until December 2016. Patients were categorized as high-flux HD patients if they underwent this treatment exclusively. If >90% of their treatment was with online hemodiafiltration, then the patient was grouped to that modality. RESULTS: After PSM, a total of 1,012 patients were matched. Compared with patients on high-flux HD, those on online hemodiafiltration received a median replacement volume of 23.45 (interquartile range 21.27-25.51) L/session and manifested 24 and 33% reductions in all-cause and cardiovascular mortality (all-cause mortality hazards ratio [HR] 0.76, 95% CI 0.62-0.94 [p = 0.01]; and cardiovascular mortality HR 0.67, 95% CI 0.50-0.90 [p = 0.008]). CONCLUSIONS: This study shows that post-dilution online hemodiafiltration reduces all-cause and cardiovascular mortality compared to high-flux HD in an incident HD population.

Hemodialysis patients receiving a greater Kt dose than recommended have reduced mortality and hospitalization risk.

Achieving an adequate dialysis dose is one of the key goals for dialysis treatments. Here we assessed whether patients receiving the current cleared plasma volume (Kt), individualized for body surface area per recommendations, had improved survival and reduced hospitalizations at 2 years of follow-up. Additionally, we assessed whether patients receiving a greater dose gained more benefit. This prospective, observational, multicenter study included 6129 patients in 65 Fresenius Medical Care Spanish facilities. Patients were classified monthly into 1 of 10 risk groups based on the difference between achieved and target Kt. Patient groups with a more negative relationship were significantly older with a higher percentage of diabetes mellitus and catheter access. Treatment dialysis time, effective blood flow, and percentage of on-line hemodiafiltration were significantly higher in groups with a higher dose. The mortality risk profile showed a progressive increase when achieved minus target Kt became more negative but was significantly lower in the group with 1 to 3 L clearance above target Kt and in groups with greater increases above target Kt. Additionally, hospitalization risk appeared significantly reduced in groups receiving 9 L or more above the minimum target. Thus, prescribing an additional 3 L or more above the minimum Kt dose could potentially reduce mortality risk, and 9 L or more reduce hospitalization risk. As such, future prospective studies are required to confirm these dose effect findings.

Identificar situaciones de riesgo para los pacientes en hemodiálisis mediante la adecuada valoración de su composición corporal / Risk identification in haemodialysis patients by appropriate body composition assessment

Introducción Circunstancias como el género, la edad, la presencia de diabetes mellitus (DM) y la insuficiencia renal tienen impacto sobre la composición corporal de los pacientes. Sin embargo, a la hora de evaluar parámetros nutricionales como el tejido magro y graso de los pacientes en hemodiálisis (HD) se emplean valores de referencia provenientes de población sana. Objetivos: Analizar la composición corporal mediante bioimpedancia espectroscópica (BIS) de 6.395 pacientes en HD para obtener valores de referencia de índice de tejido magro (ITM) y de índice de tejido graso (ITG) procedentes de pacientes en HD y confirmar su validez al demostrar que aquellos con un ITM por debajo del percentil 10 calculado para su grupo tienen mayor riesgo de muerte. Material y métodos Usamos la BIS para determinar el ITM e ITG de nuestra cohorte de pacientes en HD en España. Calculamos el percentil 10 y el percentil 90 del ITM e ITG en cada decil de edad de pacientes, agrupados según su género y presencia de DM. Recogemos parámetros clínicos, analíticos y demográficos. Resultados: Objetivamos que los valores del percentil 10 y del 90 de ITM/ITG varían en función del grupo (edad, género y presencia de DM) y que, tras ajustar por otros factores de riesgo como la sobrehidratación, los pacientes con ITM inferior al percentil 10 tienen mayor riesgo relativo de muerte (OR 1,57) que aquellos con valores superiores. Conclusiones: Monitorizar el ITM e ITG de los pacientes en HD CON adecuados valores de referencia puede ser útil para identificar situaciones de riesgo en los pacientes en HD (AU)

Introduction: Circumstances such as gender, age, diabetes mellitus (DM) and renal failure impact on the body composition of patients. However, we use nutritional parameters such as lean and fat tissue with reference values from healthy subjects to assess the nutritional status of haemodialysis (HD) patients. Aims: To analyse body composition by bioimpedance spectroscopy (BIS) of 6395 HD patients in order to obtain reference values of lean tissue index (LTI) and fat tissue index (FTI) from HD patients; and to confirm its validity by showing that those patients with LTI below the 10th percentile calculated for their group have greatest risk of death. Material and methods: We used the BIS to determine the LTI and FTI in our cohort of HD patients in Spain. We calculated the 10th percentile and 90th percentile of LTI and FTI in each age decile for patients grouped by gender and presence of DM. We collected clinical, laboratory and demographic parameters. Results: The LTI/FTI 10 and 90 percentile values varied by group (age, gender and presence of DM) and, after adjusting for other risk factors such as fluid overload, those patients with LTI lower than percentile 10 had a higher relative risk of death (OR 1.57) than those patients with higher values. Conclusions: Monitoring the LTI and FTI of patients on HD using suitable reference values may help to identify risk in this patient population (AU)

Risk identification in haemodialysis patients by appropriate body composition assessment. / Identificar situaciones de riesgo para los pacientes en hemodiálisis mediante la adecuada valoración de su composición corporal.

INTRODUCTION: Circumstances such as gender, age, diabetes mellitus (DM) and renal failure impact on the body composition of patients. However, we use nutritional parameters such as lean and fat tissue with reference values from healthy subjects to assess the nutritional status of haemodialysis (HD) patients. AIMS: To analyse body composition by bioimpedance spectroscopy (BIS) of 6395 HD patients in order to obtain reference values of lean tissue index (LTI) and fat tissue index (FTI) from HD patients; and to confirm its validity by showing that those patients with LTI below the 10th percentile calculated for their group have greatest risk of death. MATERIAL AND METHODS: We used the BIS to determine the LTI and FTI in our cohort of HD patients in Spain. We calculated the 10th percentile and 90th percentile of LTI and FTI in each age decile for patients grouped by gender and presence of DM. We collected clinical, laboratory and demographic parameters. RESULTS: The LTI/FTI 10 and 90 percentile values varied by group (age, gender and presence of DM) and, after adjusting for other risk factors such as fluid overload, those patients with LTI lower than percentile 10 had a higher relative risk of death (OR 1.57) than those patients with higher values. CONCLUSIONS: Monitoring the LTI and FTI of patients on HD using suitable reference values may help to identify risk in this patient population.

Hiponatremia, mortalidad y hemodiálisis: una asociación no explicada / Hyponatraemia, mortality and haemodialysis: An unexplained association

Introducción: Al igual que en la población general, en los pacientes en hemodiálisis (HD), la hiponatremia también se asocia a mayor riesgo de muerte. El objetivo de este trabajo es estudiar en la población en HD la relación entre natremia y mortalidad. Definir hiponatremia en HD y determinar qué peculiaridades tienen los pacientes hiponatrémicos en relación con aspectos antropométricos, analíticos, dialíticos y de hidratación, mediante bioimpedancia. Metodos: Estudio observacional, descriptivo, de una cohorte de pacientes incidentes en HD. La variable independiente fue la media de las natremias medidas en los 6 primeros meses en HD. Resultados: Se incluyó a 4.153 pacientes. La edad media era de 64,7 años y predominaban los hombres con un 64,2%. Un 34,8% eran diabéticos. El tiempo medio de seguimiento fue 21,48 (DE) (1,31) meses. Las natremias tenían una distribución normal, con una media (DE) de 138,46 (2,7) mEq/l. Las variables que presentan diferencias significativas en función de los cuartiles de natremia son: peso, diabetes, presión arterial sistólica, ganancia de peso interdialítica, ultrafiltración total, glucemia, albúmina y creatinina séricas y tipo de acceso vascular y de HD. El índice de masa magra (LTI) en los pacientes con hiponatremia, Q1 (135 mEq/l), fue significativamente más bajo que el del resto de pacientes. Los pacientes con una natremia menor de 136 mEq/l tienen un riesgo independiente de mortalidad mayor que el resto (OR=1,62) (análisis de regresión de Cox). Conclusiones: Los pacientes en HD con hiponatremia tienen mal pronóstico y presentan desnutrición o sobrecarga de volumen (AU)

Background: As in the general population, in patients on haemodialysis (HD) hyponatraemia is associated with higher mortality risk. The objective of this article was to study the relationship between predialysis serum sodium (sNa) and mortality in an HD population. We also intended to define hyponatraemia and determine the characteristics of hyponatraemic patients in terms of anthropometric data, analytical features, dialysis measurements and hydration (bioimpedance). Methods: Observational, descriptive study of a cohort of HD incident patients. The independent variable was the mean of each patient's sNa analysed during their first 6 months on HD. Results: A total of 4,153 patients were included in the study. Mean age was 64.7 years; 65.2% of the patients were male and 35% were diabetics. Mean follow-up time was 21.48 (SD) (1.31) months. sNa had a normal distribution, with a mean (SD)=138.46 (2.7) mEq/l. Body weight, diabetes mellitus, systolic blood pressure, interdialytic weight gain, total ultrafiltration, serum glucose, albumin and creatinine, vascular access and haemodialysis type, acquire significant differences between sodium quartiles. Lean tissue index (LTI) in patients with low serum sodium, Q1 (135 mEq/l), was significantly lower than the LTI of patients from the other serum sodium quartiles. Patients with sNa<136 mEq/l had a higher independent mortality risk (OR=1.62) (Cox regression analysis). Conclusions: HD patients with hyponatraemia patients have a poor prognosis and present malnutrition or fluid overload (AU)

Hyponatraemia, mortality and haemodialysis: An unexplained association.

BACKGROUND: As in the general population, in patients on haemodialysis (HD) hyponatraemia is associated with higher mortality risk. The objective of this article was to study the relationship between predialysis serum sodium (sNa) and mortality in an HD population. We also intended to define hyponatraemia and determine the characteristics of hyponatraemic patients in terms of anthropometric data, analytical features, dialysis measurements and hydration (bioimpedance). METHODS: Observational, descriptive study of a cohort of HD incident patients. The independent variable was the mean of each patient's sNa analysed during their first 6 months on HD. RESULTS: A total of 4,153 patients were included in the study. Mean age was 64.7 years; 65.2% of the patients were male and 35% were diabetics. Mean follow-up time was 21.48 (SD) (1.31) months. sNa had a normal distribution, with a mean (SD)=138.46 (2.7) mEq/l. Body weight, diabetes mellitus, systolic blood pressure, interdialytic weight gain, total ultrafiltration, serum glucose, albumin and creatinine, vascular access and haemodialysis type, acquire significant differences between sodium quartiles. Lean tissue index (LTI) in patients with low serum sodium, Q1 (135 mEq/l), was significantly lower than the LTI of patients from the other serum sodium quartiles. Patients with sNa<136 mEq/l had a higher independent mortality risk (OR=1.62) (Cox regression analysis). CONCLUSIONS: HD patients with hyponatraemia patients have a poor prognosis and present malnutrition or fluid overload.

Improved survival of incident patients with high-volume haemodiafiltration: a propensity-matched cohort study with inverse probability of censoring weighting.

BACKGROUND: Haemodiafiltration (HDF) is the preferred dialysis modality in many countries. The aim of the study was to compare the survival of incident patients on high-volume HDF (HV-HDF) with high-flux haemodialysis (HD) in a large-scale European dialysis population. METHODS: The study population was extracted from 47,979 patients in 369 NephroCare centres throughout 12 countries. Baseline was six months after dialysis initiation; maximum follow-up was 5 years. Patients were either on HV-HDF (defined as with ≥21 litres substitution fluid volume per session) or on HD if on that treatment for ≥75% of the 3 months before baseline. The main predictor was treatment modality. Other parameters included country, age, gender, BMI, haemoglobin, albumin and Charlson comorbidity index. Propensity score matching and Inverse Probability of Censoring Weighting (IPCW) were applied to reduce bias by indication and consider modality crossover, respectively. RESULTS: After propensity score matching, 1,590 incident patients remained. Kaplan-Meier and proportional Cox regression analyses revealed no significant survival advantage of HV-HDF. Results were biased by modality crossover: during the 5-year study period, 7% of HV-HDF patients switched to HD, and 55% of HD patients switched to HV-HDF. IPCW uncovered a statistically significant survival advantage of HV-HDF (OR 0.501; CI 0.366-0.684; p < 0.001). A higher benefit of HV-HDF for some subgroups was revealed, for example, non-diabetics, patients 65-74 years, patients with obesity or high blood pressure. CONCLUSIONS: This large-scale study supports the generalizability of previous RCT findings regarding the survival benefit of HV-HDF. Sub-group analysis showed that some sub-cohorts appear to benefit more from HV-HDF than others.

Impact of targeting Kt instead of Kt/V.

BACKGROUND: Patients must receive an adequate dialysis dose in each hemodialysis (HD) session. Ionic dialysance (ID) enables the dialysis dose to be monitored in each session. The aim of this study was to compare the achievement of Kt versus eKt/V values and to analyse the main impediments to reaching the dialysis dose. METHODS: Of 5316 patients from 54 Fresenius Medical Care centers in Spain undergoing their usual HD regime, 3275 received ID and were included in the study. RESULTS: The minimum prescribed dose of eKt/V was reached in 91.2% of the patients, while the minimum recommended dose of Kt was reached in only 66.8%. Patients not receiving the minimum Kt dose were older, had spent 7 months less on dialysis, had a dialysis duration of 6 min less, had 5.7 kg more of body weight and Qb was 47 mL/min lower. The target Kt was not reached by 62% of patients with catheters and by 37% of women. With each quintile increase of body weight, eKt/V decreased and Kt increased. Of patients with a body weight >80 kg, 1.4%, mostly men, reached the target Kt but not prescribed eKt/V. CONCLUSIONS: The impact of monitoring the dose with Kt instead of Kt/V is that identifies 25.8% of patients who did not reach the minimum Kt while achieving Kt/V. The main impediments to achieving an adequate dialysis dose were catheter use, female sex, advanced age, greater body weight, shorter dialysis time and lower Qb.

Type of vascular access and survival among very elderly hemodialysis patients.

The use of central venous catheters (CVC) for hemodialysis (HD) is associated with higher mortality compared to arteriovenous access (AV). However, studies analyzing the influence of the type of vascular access on the survival of very elderly patients (≥75 years) initiating HD are few and involve only a limited number of patients. We studied a cohort of 5,466 incident patients who started HD; of these, 1,841 were aged ≥75. Types of vascular access for HD were classified as either CVC, which included both tunneled and non-tunneled catheters, or AV, which included AV fistula and grafts. The outcome of the study was all-cause mortality during the follow-up period. In the whole cohort, AV use was associated with a survival advantage over CVC use (88 and 63% at 2 and 5 years, respectively, in patients with an AV as compared to 75 and 48% in patients with a CVC) (p < 0.0001). Among patients ≥75, CVC use was associated with a higher number of deaths compared to AV use. Patients ≥75 with an AV showed a greater survival as compared to patients ≥75 with a CVC (80 and 53% at 2 and 5 years, respectively, vs. 68 and 43%; p < 0.0001). Multivariate analysis revealed that CVC use and the presence of arrhythmia were independent risk factors of death in patients ≥75, whereas obesity was associated with greater survival. In conclusion, the type of vascular access has a significant influence on the survival of very elderly patients (≥75) initiating HD. CVC use was associated with poorer survival compared to AV access.

Assessment of quality guidelines implementation using a continuous quality improvement programme.

BACKGROUND: Data from the Dialysis Outcomes and Practice Patterns Study (DOPPS) study suggest that the level of implementation of the European Best Practice Guidelines (EBPG) is at best partial. The main aim of this study is to describe the level of implementation of the EBPG in the European Fresenius Medical Care (FME) clinic network. METHODS: Data presented in this investigation were gained through the FME database EuCliD (European Clinical Database). Patient data from 4 countries (Great Britain, France, Italy, Spain) were selected from the EuCliD database. The parameters chosen were haemodialysis adequacy, biocompatibility, anaemia control and serum phosphate control, which are surrogate indicators for quality of care. They were compared, by country, between the first quarter (Q1) 2002 and the fourth quarter (Q4) 2005. RESULTS: During Q1 2002 and Q4 2005, respectively, a total of 7,067 and 9,232 patients were treated in FME clinics located in France, Italy, Spain and the UK. This study confirms variations in haemodialysis practices between countries as already described by the DOPPS study. A large proportion of patients in each country achieved the targets recommended by the EBPG in Q4 2005 and this represented a significant improvement over the results achieved in Q1 2002. CONCLUSIONS: Differences in practices between countries still exist. The FME CQI programme allows some of these differences to be overcome leading to an improvement in the quality of the treatment delivered.