MO1007RELATIONSHIP BETWEEN DIALYSIS ADEQUACY, ULTRAFILTRATION RATE AND SURVIVAL IN YOUNG HEMODIALYSIS (HD) PATIENTS HAVING INITIATED CHRONIC HD IN CHILDHOOD*

Background and Aims Hemodialysis (HD) adequacy is currently assessed based on weight-normalized small solute clearance (spKt/V), with same targets in both adult and pediatric patients on chronic thrice weekly hemodialysis, despite lack of pediatric studies to support this. It has been hypothesised that pediatric patients of small size may require higher spKt/V targets, due to higher ratio of body surface area (BSA) to body weight and/or greater post-dialysis urea rebound. Ultrafiltration rates (UFR) >10-13 mL/kg/h, associated with increased mortality in adults, are furthermore routinely exceeded in pediatric patients with uncertain consequences. We aimed to characterize how different delivered HD adequacy metrics and UFR are associated with survival in a large cohort of patients who started HD in childhood. Method Retrospective analysis on a cohort of patients <30y on chronic HD since childhood (<19y), having received thrice-weekly HD 2004-2016 in outpatient DaVita dialysis centers. Mean delivered dialysis dose (spKt/V) and alternative measures of HD adequacy and fluid balance, including eKt/V, body-surface normalized Kt (Kt/BSA) and ultrafiltration rate (UFR), were investigated as predictors of survival in a Weibull regression model. Results A total of 1780 patients were included (age at initiation of HD: 0-12y: n=321, >12-18y: n=1459), with median spKtV=1.55, eKt/V=1.31, Kt/BSA=31.2 L/m2 and UFR=10.6 mL/kg/h. Kt/BSA was a better predictor of survival than spKt/V or eKt/V (P<0.001 versus P=0.002, respectively). UFR was associated with survival (P<0.001), with increased mortality <10/>18 mL/kg/h. Associations remained significant after adjusting for age, ethnicity, and etiology of kidney disease. Conclusion We found that targeting Kt/BSA>30 L/m2 in children and young adults on maintenance HD is associated with improved long-term outcomes, corresponding to spKt/V>1.4 (>12 years) and >1.6 (<12 years), respectively. Relatively high UFR of 10-18 ml/kg/h appears to be risk-free in this HD population.

MO834LOWER POST DIALYSIS POTASSIUM AND HIGHER ULTRAFILTRATION RATE ARE INDEPENDENT PREDICTORS OF ALL-CAUSE MORTALITY IN DIALYSIS PATIENTS

Background and Aims Dialysis is a life-saving procedure for the end-stage kidney disease, but mortality in this category of patients is still high. The survival of these patients is much lower compared to the general population. Factors affecting this survival has been studied for years and still continue to be an important part of current studies. While ultrafiltration rate is known to be associated with mortality in prevalent dialysis patients an important predictor of survival is the control of potassium profile. The aim of our study was to assess the hemodynamic and biochemical data, and to identify any significant association between post-dialysis potassium and all-cause mortality. Method This is a prospective study of 308 patients on maintenance dialysis, followed for seven years, ending 2019. All patients are dialysis dependent for ESKD and getting treatment in a single-center. Hypokalemia was defined as a serum potassium level < 3.5 mEq/L and high ultrafiltration rate (UFR) > 13 ml/kg/h. Other hemodynamic and metabolic data were also evaluated The survival rate was analysed by Kaplan-Meier curves and Cox regression analysis. Results A total of 308 patients were enrolled in this study. Mean age was 52 ± 15.6 years; 62.3% of pts were male; BMI 24.7±4.2. Of these, 55 patients (17.9%) died during the follow-up period. Our data showed the presence left ventricular hypertrophy (p=0.010), peripheral artery disease (p<0.0001), diastolic disfunction (p<0.01) and ultrafiltration rate during dialysis >13ml/kg/h (p=0.002) were the most important predictors of mortality. Metabolic abnormalities, low albumin (p<0.0005), hyperphosphatemia (p=0.011), post-dialysis potassium (p=0.037) were significantly associated with higher mortality. Logistic regression analysis of the metabolic data identified post-dialysis potassium (OR 0.242, 95% CI 0.074 – 0.793, p=0.019), and logistic regression analysis of the hemodynamic data identified ultrafiltration ratio (OR 0.149, CI 0.033 – 0.673, p=0.013) as independent predictors of all-cause mortality. Conclusion Lower post dialysis potassium levels and higher ultrafiltration rate are independently associated with higher all-cause and CV mortality in prevalent hemodialysis patients. Therefore the potassium profile and the UFR of the dialysis patients needs close monitoring and optimal control. The individualization of the dialysis prescription is recommended for each patient and it has an important role in preventing the occurrence of complication with immediate and long term effects. Management of dialysis patients should focus especially on reducing the risk of hypokalemia, not only that of hyperkalemia.

High Ultrafiltration Increasing Intradialytic Blood Pressure on Hemodialysis Patients

The increase in blood pressure when the patient is undergoing hemodialysis is experienced by patients with intradialytic hypertension. This condition can be very dangerous for the patient, must be prevented and needs to be controlled. Prevention can be done by controlling variables that can affect intradialytic blood pressure, including ultrafiltration during hemodialysis. This study aims to analyze the relationship between ultrafiltration (ultrafiltration goal, ultrafiltration rate) and intradialytic blood pressure. This research was a descriptive-analytic study with a cross-sectional design, with 112 samples at two centres of dialysis in Semarang. Data were analyzed using the Spearman Rho. The finding obtained showed that ultrafiltration goal (UFG) and ultrafiltration rate (UFR) correlated with intradialytic blood pressure (systolic, diastolic and mean arterial pressure). The magnitude of UFG an associated with increase in intradialytic systolic (p=0,024; r=0,213), increase in intradialytic diastolic (p=0,007; r=0,252) and increase in mean arterial pressure (p=0,016; r=0,227). High UFR is associated with with increase in intradialytic systolic (p=0,037; r=0,211), increase in intradialytic diastolic (p=0,001; r=0,320) and increase in mean arterial pressure (p=0,034; r=0,200). Determination of ultrafiltration during hemodialysis must be done carefully and precisely to prevent an increase in intradialytic blood pressure.

Hemodialysis (HD) dose and ultrafiltration rate are associated with survival in pediatric and adolescent patients on chronic HD—a large observational study with follow-up to young adult age

Background Hemodialysis (HD) dose targets and ultrafiltration rate (UFR) limits for pediatric patients on chronic HD are not known and are derived from adults (spKt/V>1.4 and <13 ml/kg/h). We aimed to characterize how delivered HD dose and UFR are associated with survival in a large cohort of patients who started HD in childhood. Methods Retrospective analysis on a cohort of patients <30 years, on chronic HD since childhood (<19 years), having received thrice-weekly HD 2004–2016 in outpatient DaVita centers. Outcome: Survival while remaining on HD. Predictors: (I) primary analysis: mean delivered dialysis dose stratified as spKt/V ≤1.4/1.4–1.6/>1.6 (Kaplan–Meier analysis), (II) secondary analyses: UFR and alternative dialysis adequacy measures [eKt/V, body-surface normalized Kt/BSA] on continuous scale (Weibull regression model). Results A total of 1780 patients were included (age at the start of HD: 0–12y: n=321, >12–18y: n=1459; median spKt/V=1.55, eKt/V=1.31, Kt/BSA=31.2 L/m2, UFR=10.6 mL/kg/h). (I) spKt/V<1.4 was associated with lower survival compared to spKt/V>1.4–1.6 (P<0.001, log-rank test), and spKt/V>1.6 (P<0.001), with 10-year survival of 69.3% (59.4–80.9%) versus 83.0% (76.8–89.8%) and 84.0% (79.6–88.5%), respectively. (II) Kt/BSA was a better predictor of survival than spKt/V or eKt/V. UFR was additionally associated with survival (P<0.001), with increased mortality <10/>18 mL/kg/h. Associations did not alter significantly following adjustment for demographic characteristics (age, etiology of kidney disease, and ethnicity). Conclusions Our results suggest usefulness of targeting Kt/BSA>30 L/m2 for best long-term outcomes, corresponding to spKt/V>1.4 (>12 years) and >1.6 (<12 years). In contrast to adults, higher UFR of 10–18 ml/kg/h was not associated with greater mortality in this population.

Association Between Implementation Of Novel Therapies And Improved Survival In Patients Starting Hemodialysis: The Swedish Renal Registry 2006-2015

Background The recent years have witnessed significant therapeutic advances for patients on hemodialysis. We evaluated temporal changes in treatments practices and survival rates among incident hemodialysis patients. Methods Observational study of patients initiating hemodialysis in Sweden 2006-2015. Trends of hemodialysis-related practices, medications, and routine laboratory biomarkers were evaluated. The incidence of death and major cardiovascular events (MACE) across calendar years were compared against the age-sex-matched general population. Via Cox regression, we explored whether adjustment for implementation of therapeutic advances modified observed survival and MACE risks. Results Among 6,612 patients, age and sex were similar, but the burden of co-morbidities increased over time. The proportion of patients receiving treatment by hemodiafiltration, &gt;3 sessions/week, lower ultrafiltration rate, and working fistulas increased progressively, as did use of non-calcium phosphate binders, cinacalcet, and vitamin D3. The standardized 1-year mortality decreased from 13.2% in 2006/07 to 11.1% in 2014/15. The risk of death decreased by 6% (HR 0.94, 95% CI 0.90-0.99) every two years, and the risk of MACE by 4% (HR 0.96; 0.92-1.00). Adjustment for changes in treatment characteristics abrogated these associations (HR 1.00; 0.92-1.09 for death and 1.00; 0.94-1.06 for MACE). Compared with the general population, the risk of death declined from 6 times higher 2006/2007 [standardized incidence rate ratio, sIRR 6.0 (5.3–6.9)], to 5.6 higher 2014/15 [sIRR 5.57 (4.8–6.4)]. Conclusions Gradual implementation of therapeutic advances over the last decade was associated with a parallel reduction in short-term risk of death and MACE among hemodialysis patients.

Fibroblast growth factor 23 (FGF23) level is associated with ultrafiltration rate in patients on hemodialysis

Fibroblast growth factor 23 (FGF23) is a bone-derived hormone that regulates renal phosphate reabsorption and vitamin D synthesis in renal proximal tubules. High circulating FGF23 levels are associated with increased mortality in patients with chronic kidney disease and those on dialysis. Current data also suggest higher circulating levels of FGF23 are associated with cardiovascular mortality, vascular calcification, and left ventricular hypertrophy; however, evidence on the role of FGF23 in patients on dialysis is incomplete, and some of the data, especially those on cardiovascular disease (CVD), are controversial. This study aimed to evaluate factors associated with FGF23 in hemodialysis patients with or without CVD. Randomly selected 76 patients on maintenance hemodialysis at a single hemodialysis center were enrolled. After the exclusion of eight patients with extremely outlying FGF23 levels, 68 patients, including 48 males and 46 patients with a CVD history, were included in the study. The mean age was 64.4 ± 12.1 years, and the mean dialysis duration was 12.7 ± 7.1 years. Dialysis duration, time-averaged concentration of urea (TAC-urea), ultrafiltration rate (UFR), blood pressure during hemodialysis session, laboratory data, and echocardiographic parameters including interventricular septum thickness (IVST), left ventricular mass indices (LVMI), and ejection fraction were included in univariate and multivariate analyses. The median lgFGF23 levels in the overall cohort and in those with and without CVD were 2.14 (interquartile range, IQR − 0.43 to − 4.23), 2.01 (− 0.52 to 4.12), and 2.59 (0.07 to 4.32), respectively, and there was no difference between the patients with and without CVD (p = 0.14). The univariate analysis revealed that FGF23 was significantly associated with age (r = − 0.12, p < 0.01), duration of hemodialysis (r = − 0.11, p < 0.01), TAC-urea (r = 0.29, p = 0.01), UFR (r = 0.26, p = 0.04), alkaline phosphatase (ALP; r = − 0.27, p = 0.03), corrected serum calcium (cCa; r = 0.32, p < 0.01), serum phosphate (iP, r = 0.57, p < 0.01), intact parathyroid hormone (iPTH; r = 0.38, p < 0.01), IVST (r = 0.30, p = 0.01), and LVMI (r = 0.26, p = 0.04). In multivariate regression analysis, FGF23 was significantly associated with cCa (F = 25.6, p < 0.01), iP (F = 22.5, p < 0.01), iPTH (F = 19.2, p < 0.01), ALP (F = 5.34, p = 0.03), and UFR (F = 3.94, p = 0.05). In addition, the univariate analysis after the categorization of patients according to CVD indicated that FGF23 was significantly associated with cCa (r = 0.34, p = 0.02), iP (r = 0.41, p < 0.01), iPTH (r = 0.39, p = 0.01), and TAC-urea (r = 0.45, p < 0.01) in patients with CVD, whereas only IVST (r = 0.53, p = 0.04) was associated with FGF23 in those without CVD. FGF23 levels in hemodialysis patients were extremely high and associated not only with mineral bone disease-related factors but also with UFR. Additionally, dialysis efficacy might be associated with lower FGF23 levels in patients with CVD.