Intradialytic hypotension and risk of cardiovascular disease

Long-term impacts of hemodialysis on the right ventricle: Assessment via 3-dimensional speckle-tracking echocardiography

BACKGROUND

Right ventricular (RV) dysfunction is a major cause of death in patients undergoing maintenance hemodialysis (MHD). We used 3-dimensional speckle-tracking echocardiography (3DSTE) to evaluate long-term impacts of MHD on RV function.

HYPOTHESIS

In this study, RV dysfunction in MHD patients will be revealed and studied in depth by 3DSTE.

METHODS

Echocardiography was performed on 110 consecutively enrolled individuals: 30 controls and 80 patients with MHD. Conventional echocardiographic parameters and 3DSTE parameters were obtained and compared between groups. Univariate and multivariate logistic regression analysis identified independent predictors of intradialytic hypotension (IDH).

RESULTS

Compared with the control group, RV end-diastolic volume (RVEDV) was markedly enlarged (46.1 ± 11.8 mL/m² vs 42.3 ± 8.6 mL/m² ; P = 0.047), whereas RV ejection fraction (RVEF) was significantly lower in the MHD group (50.6% ± 5.8% vs 55.2% ± 3.7%; P < 0.001). RV global, septal, and lateral wall longitudinal strains were also decreased in the MHD group (-18.2 ± 3.6 vs -22.6 ± 4.3%; -13.1 ± 3.8 vs -17.5 ± 5.5%; and -23.4 ± 4.7 vs -27.7 ± 4.0%, respectively; all P < 0.001). RVEF (odds ratio [OR]: 0.72, 95% confidence interval [CI]: 0.51 to 1.01, P = 0.038) and history of diabetes (OR: 11.14, 95% CI: 1.16 to 106.71, P = 0.036) were 2 independent predictors of IDH. Ultrafiltration rate was an independent factor associated with RVEF (β = -0.01, 95% CI: -0.019 to 0.001, P = 0.039).

CONCLUSIONS

RVEF by 3DSTE could be an important predictor of IDH in MHD patients, and lower ultrafiltration rate was protective for RVEF. 3DSTE may have potential in RV evaluation and risk stratification in MHD patients.

Intradialytic hypotension

PURPOSE OF REVIEW

This review focuses on recent advances in our understanding of intradialytic hypotension (IDH) and measures that may reduce its frequency.

RECENT FINDINGS

The frequency and severity of IDH predict the risk for adverse clinical outcomes. The highest mortality risks associated with IDH were observed when the intradialytic systolic blood pressure (SBP) nadirs were <90 and <100 mmHg and the predialysis SBP were ≤159 mmHg or ≥160 mmHg, respectively. Interdialytic weight gain (IDWG) ≥3 kg occurs more frequently among patients with IDH. Prolonged and possibly more frequent dialysis, use of biofeedback devices, dialysate cooling and limiting sodium loading are useful measures to reduce the frequency of IDH.

SUMMARY

Frequent IDH is associated with high IDWGs and a poor prognosis. Studies on prolonged dialysis, biofeedback devices and cooled dialysate have yielded promising results. Intradialytic relative blood volume monitoring devices have been investigated in preventing IDH but results are mixed. Administration of a sodium/hydrogen exchange isoform 3 inhibitor increases stool sodium but has not been shown to decrease IDWG. IDH continues to be a significant dialysis complication deserving of further investigation.

Impaired Gut Epithelial Tight Junction Expression in Hemodialysis Patients Complicated with Intradialytic Hypotension

BACKGROUND

There is accumulating evidence pointing to uremia-induced impairment of the intestinal epithelial barrier structure in advanced chronic kidney disease (CKD) and hemodialysis (HD) patients. In this study, the impact of intradialytic hypotension on intestinal barrier integrity is being explored.

METHODS

Immunohistochemical staining was used to detect the expression of 4 types of tight junction (TJ) proteins such as occludin, zonula occludens-1 (ZO-1), claudin-1, and claudin-4, in colonic samples of a group of patients receiving segmental colectomy. Five patients with nondialysis CKD (group 2), 5 HD patients with intradialytic hypotension (group 3), and 5 non-CKD subjects (group 1) were examined.

RESULTS

Both patients' groups 2 and 3 demonstrated significantly reduced expression of occludin as compared to group 1 (p < 0.05 and p < 0.01, resp.). Except for claudin-4, expression of all markers of TJ proteins was significantly reduced in patients' group 3 as compared to control (p < 0.01). In addition, decreased expressions of claudin-1 and ZO-1 were also more pronounced in group 3 when compared to group 2.

CONCLUSIONS

This study extends the earlier finding by demonstrating that dialysis-related hypotension caused even marked depletion of the key protein constituents of the epithelial TJ.

Multiple-frequency bioimpedance devices for fluid management in people with chronic kidney disease receiving dialysis: a systematic review and economic evaluation

BACKGROUND

Chronic kidney disease (CKD) is a long-term condition requiring treatment such as conservative management, kidney transplantation or dialysis. To optimise the volume of fluid removed during dialysis (to avoid underhydration or overhydration), people are assigned a 'target weight', which is commonly assessed using clinical methods, such as weight gain between dialysis sessions, pre- and post-dialysis blood pressure and patient-reported symptoms. However, these methods are not precise, and measurement devices based on bioimpedance technology are increasingly used in dialysis centres. Current evidence on the role of bioimpedance devices for fluid management in people with CKD receiving dialysis is limited.

OBJECTIVES

To evaluate the clinical effectiveness and cost-effectiveness of multiple-frequency bioimpedance devices versus standard clinical assessment for fluid management in people with CKD receiving dialysis.

DATA SOURCES

We searched major electronic databases [e.g. MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, Science Citation Index and Cochrane Central Register of Controlled Trials (CENTRAL)] conference abstracts and ongoing studies. There were no date restrictions. Searches were undertaken between June and October 2016.

REVIEW METHODS

Evidence was considered from randomised controlled trials (RCTs) comparing fluid management by multiple-frequency bioimpedance devices and standard clinical assessment in people receiving dialysis, and non-randomised studies evaluating the use of the devices for fluid management in people receiving dialysis. One reviewer extracted data and assessed the risk of bias of included studies. A second reviewer cross-checked the extracted data. Standard meta-analyses techniques were used to combine results from included studies. A Markov model was developed to assess the cost-effectiveness of the interventions.

RESULTS

Five RCTs (with 904 adult participants) and eight non-randomised studies (with 4915 adult participants) assessing the use of the Body Composition Monitor [(BCM) Fresenius Medical Care, Bad Homburg vor der Höhe, Germany] were included. Both absolute overhydration and relative overhydration were significantly lower in patients evaluated using BCM measurements than for those evaluated using standard clinical methods [weighted mean difference -0.44, 95% confidence interval (CI) -0.72 to -0.15, p = 0.003, I2 = 49%; and weighted mean difference -1.84, 95% CI -3.65 to -0.03; p = 0.05, I2 = 52%, respectively]. Pooled effects of bioimpedance monitoring on systolic blood pressure (SBP) (mean difference -2.46 mmHg, 95% CI -5.07 to 0.15 mmHg; p = 0.06, I2 = 0%), arterial stiffness (mean difference -1.18, 95% CI -3.14 to 0.78; p = 0.24, I2 = 92%) and mortality (hazard ratio = 0.689, 95% CI 0.23 to 2.08; p = 0.51) were not statistically significant. The economic evaluation showed that, when dialysis costs were included in the model, the probability of bioimpedance monitoring being cost-effective ranged from 13% to 26% at a willingness-to-pay threshold of £20,000 per quality-adjusted life-year gained. With dialysis costs excluded, the corresponding probabilities of cost-effectiveness ranged from 61% to 67%.

LIMITATIONS

Lack of evidence on clinically relevant outcomes, children receiving dialysis, and any multifrequency bioimpedance devices, other than the BCM.

CONCLUSIONS

BCM used in addition to clinical assessment may lower overhydration and potentially improve intermediate outcomes, such as SBP, but effects on mortality have not been demonstrated. If dialysis costs are not considered, the incremental cost-effectiveness ratio falls below £20,000, with modest effects on mortality and/or hospitalisation rates. The current findings are not generalisable to paediatric populations nor across other multifrequency bioimpedance devices.

FUTURE WORK

Services that routinely use the BCM should report clinically relevant intermediate and long-term outcomes before and after introduction of the device to extend the current evidence base.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016041785.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Validating the use of bioimpedance spectroscopy for assessment of fluid status in children

BACKGROUND

Bioimpedance spectroscopy (BIS) with a whole-body model to distinguish excess fluid from major body tissue hydration can provide objective assessment of fluid status. BIS is integrated into the Body Composition Monitor (BCM) and is validated in adults, but not children. This study aimed to (1) assess agreement between BCM-measured total body water (TBW) and a gold standard technique in healthy children, (2) compare TBW_BCM with TBW from Urea Kinetic Modelling (UKM) in haemodialysis children and (3) investigate systematic deviation from zero in measured excess fluid in healthy children across paediatric age range.

METHODS

TBW_BCM and excess fluid was determined from standard wrist-to-ankle BCM measurement. TBW_D2O was determined from deuterium concentration decline in serial urine samples over 5 days in healthy children. UKM was used to measure body water in children receiving haemodialysis. Agreement between methods was analysed using paired t test and Bland-Altman method comparison.

RESULTS

In 61 healthy children (6-14 years, 32 male), mean TBW_BCM and TBW_D2O were 21.1 ± 5.6 and 20.5 ± 5.8 L respectively. There was good agreement between TBW_BCM and TBW_D2O (R² = 0.97). In six haemodialysis children (4-13 years, 4 male), 45 concomitant measurements over 8 months showed good TBW_BCM and TBW_UKM agreement (mean difference - 0.4 L, 2SD = ± 3.0 L). In 634 healthy children (2-17 years, 300 male), BCM-measured overhydration was - 0.1 ± 0.7 L (10-90th percentile - 0.8 to + 0.6 L). There was no correlation between age and OH (p = 0.28).

CONCLUSIONS

These results suggest BCM can be used in children as young as 2 years to measure normally hydrated weight and assess fluid status.

BP in Dialysis: Results of a Pilot Study

The optimal BP target for patients receiving hemodialysis is unknown. We randomized 126 hypertensive patients on hemodialysis to a standardized predialysis systolic BP of 110-140 mmHg (intensive arm) or 155-165 mmHg (standard arm). The primary objectives were to assess feasibility and safety and inform the design of a full-scale trial. A secondary objective was to assess changes in left ventricular mass. Median follow-up was 365 days. In the standard arm, the 2-week moving average systolic BP did not change significantly during the intervention period, but in the intensive arm, systolic BP decreased from 160 mmHg at baseline to 143 mmHg at 4.5 months. From months 4-12, the mean separation in systolic BP between arms was 12.9 mmHg. Four deaths occurred in the intensive arm and one death occurred in the standard arm. The incidence rate ratios for the intensive compared with the standard arm (95% confidence intervals) were 1.18 (0.40 to 3.33), 1.61 (0.87 to 2.97), and 3.09 (0.96 to 8.78) for major adverse cardiovascular events, hospitalizations, and vascular access thrombosis, respectively. The intensive and standard arms had similar median changes (95% confidence intervals) in left ventricular mass of -0.84 (-17.1 to 10.0) g and 1.4 (-11.6 to 10.4) g, respectively. Although we identified a possible safety signal, the small size and short duration of the trial prevent definitive conclusions. Considering the high risk for major adverse cardiovascular events in patients receiving hemodialysis, a full-scale trial is needed to assess potential benefits of intensive hypertension control in this population.

A brief review of intradialytic hypotension with a focus on survival

Intradialytic hypotension (IDH), a common complication of ultrafiltration during hemodialysis therapy, is associated with high mortality and morbidity. IDH, defined as a nadir systolic blood pressure of less than 90 mm Hg on more than 30% of treatments, is a relevant definition and is correlated with mortality. Risk factors for IDH include patient demographics, anti-hypertensive medication use, larger interdialytic weight gain, and dialysis prescription features as dialysate sodium, high ultrafiltration rate, and dialysate temperature. A high frequency of IDH events carries a substantial death risk. An ultrafiltration rate >10 mL/h/kg, and even more so >13 mL/h/kg, is highly predictive of cardiovascular and all-cause mortality. Evidence suggests that IDH causes acute reversible segmental myocardial hypoperfusion and contractile dysfunction (myocardial stunning), which can result in long-term loss of myocardial contractility, leading to premature death. IDH also has negative end-organ effects on the brain and gut, contributing to mortality through stroke, and endotoxin translocation with associated inflammation and protein-energy wasting. Given strong association of IDH and dialysis mortality, a paradigm shift to its approach is urgently needed. Randomized controlled trials are required to prospectively test drugs and monitoring devices which may reduce IDH.

Definitions of intradialytic hypotension

Intradialytic hypotension (IDH) is a common and often distressful complication of hemodialysis. However, despite its clinical significance, there is no consensus, evidence-based medical definition for the condition. Over the years, numerous definitions have been implemented in both the clinical and research settings. Definition inconsistencies have hindered data synthesis and the development of evidence-based guidelines for the prevention and treatment of IDH, as well as prevented accurate estimation of the population burden of IDH and patient risk assessment. Most existing IDH definitions are comprised of one or more of the following components: (1) intradialytic BP criteria (requisite BP declines or minimum BP thresholds), (2) the provision of interventions aimed at restoring effective arterial volume, and/or (3) patient-reported symptoms. Remarkably, there are insufficient data to inform IDH definition construction, and it remains unknown if a single, universal definition can adequately capture the condition across patient subgroups, and in clinical and research settings.

Intradialytic Central Venous Oxygen Saturation is Associated with Clinical Outcomes in Hemodialysis Patients

Central venous oxygen saturation (ScvO₂) in the superior vena cava is predominantly determined by cardiac output, arterial oxygen content, and oxygen consumption by the upper body. While abnormal ScvO₂ levels are associated with morbidity and mortality in non-uremic populations, ScvO₂ has received little attention in hemodialysis patients. From 1/2012 to 8/2015, 232 chronic hemodialysis patients with central venous catheters as vascular access had their ScvO₂ monitored during a 6-month baseline period and followed for up to 36 months. Patients were stratified into upper and lower two tertiles by a ScvO₂ of 61.1%. Survival analysis employed Kaplan-Meier curves and adjusted Cox proportional hazards models. Patients in the lower tertiles of ScvO₂ were older, had longer hemodialysis vintage, lower systolic blood pressure, lower ultrafiltration rates, higher leukocyte counts and neutrophil-to-lymphocyte ratios. Kaplan-Meier analysis indicated a shorter survival time in the lower tertiles of ScvO₂ (P = 0.005, log-rank test). In adjusted Cox analysis, a 1 percent point decrease in mean ScvO₂ was associated with a 4% increase in mortality (HR 1.04 [95% CI 1.01-1.08], P = 0.044), indicating that low ScvO₂ is associated with poor outcomes. Research on the relative contributions of cardiac output and other factors is warranted to further elucidate the pathophysiology underlying this novel finding.

Levocarnitine Decreases Intradialytic Hypotension Episodes: A Randomized Controlled Trial

Intradialytic hypotension is common complication in stage 5 chronic kidney disease patients on hemodialysis. Incidence ranges from 15 to 30%. These patients have levocarnitine deficiency. A randomized, placebo-controlled quadruple-blinded trial was designed to demonstrate the levocarnitine efficiency on intradialytic hypotension prevention. Patients were randomized into four groups, to receive levocarnitine or placebo. During the intervention period, levocarnitine and placebo was administered 0 and 30 min before each hemodialysis session, respectively. During the trial, 33 patients received 1188 hemodialysis sessions. We identified 239 (21.3%) intradialytic hypotension episodes. The intradialytic hypotension episodes were less frequent in the levocarnitine group (9.3%, 60 IH events) (P < 0.001). Hemodialysis is frequently perplexed by intradialytic hypotension episodes. Levocarnitine supplementation before each hemodialysis session efficiently diminishes the intradialytic hypotension episodes. This is a new application method that must be considered and explored.

Beneficial effect of kidney transplantation from a deceased donor on severe chronic refractory intradialytic hypotension - a case report

BACKGROUND

Chronic refractory hypotension (IDH, intradialytic hypotension) is a rare but serious problem encountered in patients on hemodialysis. Patients with chronic hypotension are often disqualified by transplant teams from renal transplantation. This is due to the possibility of an enormous risk of ischemic complications.

CASE PRESENTATION

We describe a 44-year old female patient with severe refractory hypotension (mean BP 60/30 mmHg, the lowest 48/28 mmHg), which appeared after bilateral laparoscopic nephrectomy of the infected kidneys. The kidney transplantation from a deceased donor, with infusion of the two pressor amines (dopamine, dobutamine) was performed without technical complications and the blood pressure measurements were 100-120/70-80 mmHg. The immunosuppression regimen was tacrolimus (TAC) + mycophenolate mophetil (MMF) and steroids (GS). Pressor amines were discontinued on the 18th day after the transplantation. Because of delayed graft function, 4 hemodialysis treatments were performed. The patient was discharged from the hospital on the 22nd day with good function of the transplanted kidney (the concentration of serum creatinine 117 μmol/l). During one-year follow-up, the patient has been remaining stable with a very good graft function (serum creatinine 84 μmol/l) and normal blood pressure (115/70 mmHg).

CONCLUSIONS

Proper preparation and adequate perioperative treatment allowed for safely performing kidney transplantation in the patient with severe IDH.

An extended Kalman filter with inequality constraints for real-time detection of intradialytic hypotension

Intradialytic hypotension (IDH) is the most common complication of hemodialysis, affecting 15-50% of all dialysis sessions. Previously, we had presented a non-invasive Polyvinylidene Fluoride (PVDF) based sensor in the form of a ring to measure vascular tone and we showed that the morphology of the signal can be utilized to predict IDH. This paper presents an approach for analyzing the PVDF signal using extended Kalman filter (EKF) and a synthetic model that has previously been used to model the ECG signal with Gaussian functions. Moreover, a novel approach for incorporating state inequality constraints into the EKF process using a gradient projection method is introduced. The taut string algorithm was first used to estimate the outline of the signal and remove it to highlight the reflection waves. Then, the EKF was used to characterize the morphology of the signal using Gaussian functions. The amplitudes of the Gaussian functions were used as features to train a classifier. The results indicated that the PPV and NPV for the prediction were 83.33% and 100%, respectively.

Higher Ultrafiltration Rate Is Associated with Longer Dialysis Recovery Time in Patients Undergoing Conventional Hemodialysis

BACKGROUND

Increased mortality and morbidity are reported in association with high ultrafiltration rate (UFR) and with long dialysis recovery time (DRT). We studied the association between UFR and DRT.

METHODS

This is a cross-sectional, observational study was conducted. Patients on thrice-weekly hemodialysis (HD) with self-reported DRT between August and December 2014 were included. We examined the association of 30-day average UFR with recovery time.

RESULTS

The total number of patients included in this study was 2,689. DRT in categories of immediate recovery, >0-≤2, >2-≤6, >6-≤12, and >12 h, were reported in 27, 28, 17, 9, and 20% of the patients respectively. In multivariable analysis, longer DRT was associated with female gender, non-black race, higher body weight, lower serum albumin, chronic heart failure, cerebrovascular disease, missed dialysis sessions, higher pre-dialysis systolic blood pressure, and larger UF volume. Compared to UFR of <10, UFR ≥13 mL/kg/h was associated with longer DRT, OR of 1.16 (95% CI 0.99-1.36), and 1.28 (95% CI 1.06-1.54) in the unadjusted and the adjusted analyses respectively. Intradialytic hypotension was also associated with longer DRT in the unadjusted (per 10% higher frequency, OR 1.04 [95% CI 1.01-1.07]) and adjusted analyses (OR 1.03 [95% CI 1.00-1.07]).

CONCLUSION

Long recovery time is common after HD. Rapid fluid removal is associated with longer DRT.

Treatment tolerance and patient-reported outcomes favor online hemodiafiltration compared to high-flux hemodialysis in the elderly

Large cohort studies suggest that high convective volumes associated with online hemodiafiltration may reduce the risk of mortality/morbidity compared to optimal high-flux hemodialysis. By contrast, intradialytic tolerance is not well studied. The aim of the FRENCHIE (French Convective versus Hemodialysis in Elderly) study was to compare high-flux hemodialysis and online hemodiafiltration in terms of intradialytic tolerance. In this prospective, open-label randomized controlled trial, 381 elderly chronic hemodialysis patients (over age 65) were randomly assigned in a one-to-one ratio to either high-flux hemodialysis or online hemodiafiltration. The primary outcome was intradialytic tolerance (day 30-day 120). Secondary outcomes included health-related quality of life, cardiovascular risk biomarkers, morbidity, and mortality. During the observational period for intradialytic tolerance, 85% and 84% of patients in high-flux hemodialysis and online hemodiafiltration arms, respectively, experienced at least one adverse event without significant difference between groups. As exploratory analysis, intradialytic tolerance was also studied, considering the sessions as a statistical unit according to treatment actually received. Over a total of 11,981 sessions, 2,935 were complicated by the occurrence of at least one adverse event, with a significantly lower occurrence in online hemodiafiltration with fewer episodes of intradialytic symptomatic hypotension and muscle cramps. By contrast, health-related quality of life, morbidity, and mortality were not different in both groups. An improvement in the control of metabolic bone disease biomarkers and β2-microglobulin level without change in serum albumin concentration was observed with online hemodiafiltration. Thus, overall outcomes favor online hemodiafiltration over high-flux hemodialysis in the elderly.

Association of Triiodothyronine Levels with Left Ventricular Function, Cardiovascular Events, and Mortality in Hemodialysis Patients

Background

Hemodialysis (HD) patients have altered free triiodothyronine (fT3) levels. A low fT3 level is a strong and inverse mortality predictor in HD patients. However, little is known about the relationship between fT3 and left ventricular function in HD patients.

Methods

A total of 128 maintenance HD patients were enrolled in this study. A thyroid function test with blood sampling and echocardiography was conducted. Low-T3 syndrome was defined as fT3 level <3.62 pmol/L and normal thyroid stimulating hormone (TSH). Overall mortality and rate of cardiovascular (CV) events were assessed during 48 months of follow-up.

Results

Low-T3 syndrome was detected in 57 (44.5%) of the 128 patients. Patients with low-T3 syndrome had a shorter duration of HD (49.1 vs. 73.3, p = 0.01), and lower serum albumin (35.1 vs. 40.4 g/L, p<0.001), left ventricular ejection fraction (LVEF; 54.7% vs. 63.9%, p<0.001), and fractional shortening at endocardial levels (endoFS; 29.3% vs. 34.8%, p = 0.001) compared to those with normal fT3 levels. In multivariate linear regression, LVEF, albumin, and duration of HD were independently correlated with fT3 levels. In addition, fT3 was also correlated with LVEF. During the study period, 13 (10.1%) patients died, CV events occurred in 15 (11.7%) patients. In Cox regression analysis, low fT3 level and elevated high-sensitivity C-reactive protein (hs-CRP) were associated with mortality and CV events.

Conclusions

In HD patients, fT3 level is positively correlated with LVEF. Low fT3 level and elevated hs-CRP predicted all-cause mortality and CV events.

The Dialysis Sodium Gradient: A Modifiable Risk Factor for Fluid Overload

Background

Fluid overload in patients on conventional hemodialysis is a frequent complication, associated with increased cardiovascular morbidity and mortality. The dialysate sodium prescription is a potential modifiable risk factor. Our primary objective was to describe associations between dialysate-to-serum sodium gradient and parameters of fluid status. A secondary objective was to evaluate the 6-month risk of hospitalization and mortality in relation to sodium gradient.

Methods

We performed a cross-sectional study of 110 prevalent conventional hemodialysis patients at a single center. The associations of sodium gradient with interdialytic weight gain index (IDWG%), ultrafiltration (UF) rate, and blood pressure (BP) were analyzed.

Results

The mean serum sodium gradient was 4.6 ± 3.6 mEq/L. There was a direct correlation between sodium gradient and IDWG% (r = 0.48, p < 0.01) as well as UF rate (r = 0.44, p < 0.01). In a logistic regression model, a 1 mEq/L higher sodium gradient was associated with increased risk of IDWG% >3% (OR 1.33, p < 0.01) and increased risk of UF rate >10 mL/kg/h (OR 1.16, p = 0.03), but there were no associations with intradialytic hypotension, intradialytic hypertension or BP. No significant differences were found with 6-month hospitalization or mortality risk in relation to sodium gradient.

Conclusion

A higher sodium gradient was associated with significant increases in IDWG and UF rates, known to be associated with poor outcomes, but was not associated with intradialytic hypotension. Individualizing the dialysate sodium prescription to minimize sodium gap may lead to less fluid overload in conventional hemodialysis patients.

Impact of rapid ultrafiltration rate on changes in the echocardiographic left atrial volume index in patients undergoing haemodialysis: a longitudinal observational study

OBJECTIVE

Optimal fluid management is essential when caring for a patient on haemodialysis (HD). However, if the fluid removal is too rapid, the resultant higher ultrafiltration rate (UFR) disadvantageously promotes haemodynamic instability and cardiac injury. We evaluated the effects of a rapid UFR on changes in the echocardiographic left atrial volume index (LAVI) over a period of time.

DESIGN

Longitudinal observational study.

SETTING AND PARTICIPANTS

A total of 124 new patients on HD.

INTERVENTIONS

Echocardiography was performed at baseline and repeated after 19.7 months (range 11.3-23.1 months). Changes in LAVI (ΔLAVI/year, mL/m²/year) were calculated. The UFR was expressed in mL/hour/kg, and we used the mean UFR over 30 days (∼12-13 treatments).

MAIN OUTCOME MEASURES

The 75th centile of the ΔLAVI/year distribution was regarded as a 'pathological' increment.

RESULTS

The mean interdialytic weight gain was 1.73±0.94 kg, and the UFR was 8.01±3.87 mL/hour/kg. The significant pathological increment point in ΔLAVI/year was 4.89 mL/m²/year. Correlation analysis showed that ΔLAVI/year was closely related to the baseline blood pressure, haemoglobin level, residual renal function and UFR. According to the receiver operating characteristics curve, the 'best' cut-off value of UFR for predicting the pathological increment was 10 mL/hour/kg, with an area under the curve of 0.712. In multivariate analysis, systolic blood pressure, a history of coronary artery disease, haemoglobin <10 g/dL and high UFR were significant predictors. An increase of 1 mL/hour/kg in the UFR was associated with a 22% higher risk of a worsening LAVI (OR 1.22, 95% CI 1.05 to 1.41).

CONCLUSIONS

An increased haemodynamic load could affect left atrial remodelling in incident patients on HD. Thus, close monitoring and optimal control of UFR are needed.

Bioimpedance and Fluid Status in Children and Adolescents Treated With Dialysis

BACKGROUND

Assessment of hydration status in patients with chronic kidney failure treated by dialysis is crucial for clinical management decisions. Dilution techniques are considered the gold standard for measurement of body fluid volumes, but they are unfit for day-to-day care. Multifrequency bioimpedance has been shown to be of help in clinical practice in adults and its use in children and adolescents has been advocated. We investigated whether application of multifrequency bioimpedance is appropriate for total-body water (TBW) and extracellular water (ECW) measurement in children and adolescents on dialysis therapy.

STUDY DESIGN

A study of diagnostic test accuracy.

SETTING & PARTICIPANTS

16 young dialysis patients (before a hemodialysis session or after peritoneal dialysis treatment) from the Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy, and the Emma Children's Hospital-Academic Medical Center, Amsterdam, the Netherlands.

INDEX TEST

TBW and ECW volumes assessed by multifrequency bioimpedance.

REFERENCE TESTS

TBW and ECW volumes measured by deuterium and bromide dilution, respectively.

RESULTS

Mean TBW volumes determined by multifrequency bioimpedance and deuterium dilution were 19.2±8.7 (SD) and 19.3±8.3L, respectively; Bland-Altman analysis showed a mean bias between the 2 methods of -0.09 (95% limits of agreement, -2.1 to 1.9) L. Mean ECW volumes were 8.9±4.0 and 8.3±3.3L measured by multifrequency bioimpedance and bromide dilution, respectively; mean bias between the 2 ECW measurements was +0.6 (95% limits of agreement, -2.3 to 3.5).

LIMITATIONS

Participants ingested the deuterated water at home without direct supervision by investigators, small number of patients, repeated measurements in individual patients were not performed.

CONCLUSIONS

Multifrequency bioimpedance measurements were unbiased but imprecise in comparison to dilution techniques. We conclude that multifrequency bioimpedance measurements cannot precisely estimate TBW and ECW in children receiving dialysis.

Dialysate temperature of 36 °C: association with clinical outcomes

Dialysate cooling, either individualized based upon patient body temperature, or to a standardized temperature below 37 °C, has been proposed to minimize hemodynamic insults and improve outcomes among hemodialysis patients. However, low dialysate temperatures (35-35.5 °C) are associated with patient discomfort, and individualized dialysate cooling is difficult to operationalize. Here, we tested whether a standardized dialysate temperature of 36 °C (dT36) was associated with improved clinical outcomes compared to the default temperature of 37 °C (dT37). Because patients with known hemodynamic instability may be selectively prescribed dT36, we minimized selection bias by considering only incident adult in-center hemodialysis patients who, between Jan 2011 and Dec 2013 received their first-ever hemodialysis treatment at a large dialysis organization. Exposure status was based on the treatment order for this first-ever treatment. 313 dT36 patients were identified and propensity-score matched (1:5) to 1565 dT37 controls. Death, hospitalization, and missed hemodialysis treatments were considered from the date of first-ever hemodialysis treatment until the earliest of death, loss to follow-up, crossover (month in which prescribed dialysate temperature was consistent with patient's exposure group for <80% of treatments), or study end (June 2015). During follow-up, rates of death, hospitalization and missed hemodialysis treatments did not differ between the two groups. This study therefor showed no benefit of dT36 vs. dT37 with respect to these clinical outcomes. Our results do not favor conversion to a default dialysate temperature of 36 °C. Individualized dialysate cooling may provide a more reliable approach to achieve the hemodynamic benefits associated with reduced dialysate temperature.

Effect of Mealtime During Hemodialysis on Patients' Complications

Introduction: Food intake during hemodialysis increases the risk of problems such as hypotension, nausea, and vomiting in patients undergoing hemodialysis. This study aimed to determine the effect of mealtime during dialysis on the patients' complications. Methods: This is a quasi-experimental study consisted of all eligible hemodialysis patients in Hamadan teaching hospitals. All of 48 patients were selected through census method. The research was conducted in two sessions. At both sessions, patients were kept fasting prior to hemodialysis. In the first session, after one hour and in the second session after two hours of hemodialysis, a meal containing 350 kcal of energy was given to the patients. Blood pressure and intensity of nausea and vomiting was measured and recorded immediately before the start of hemodialysis, and then every half an hour before the termination of the hemodialysis. Results: The results showed that in both sessions, food intake caused a drop in the systolic and diastolic blood pressure, but changes in the mealtime had no effect on the systolic and diastolic blood pressure. Also, statistical test showed that changes in the mealtime had no significant impact on the intensity of nausea and vomiting. Conclusion: Food intake during hemodialysis had no effect on the nausea and vomiting, but caused a drop in the systolic and diastolic blood pressure, the drop continued for one hour and one and a half hour after the meal. It is suggested, mealtime in the early hours of hemodialysis could be better managed during the hemodialysis process.

Risk of acute coronary syndrome after parathyroidectomy in patients with end-stage renal disease: A population-based cohort study in Taiwan

Aim

Patients with end‐stage renal disease (ESRD) who received parathyroidectomy (PTX) had persistently reduced levels of parathyroid hormone. This study investigated the risk of acute coronary syndrome (ACS) in patients with ESRD who underwent PTX using a nationwide health insurance claims database.

Methods

Of all ESRD patients, we selected 1047 individuals who had undergone PTX between 2000 and 2008 as the PTX group and 4188 patients who did not undergo PTX (non‐PTX group) matched by propensity score. Multivariable Cox proportional hazards regression analysis was conducted for assessing the excess ACS risk for the PTX group compared to the non‐PTX group.

Results

The mean follow‐up periods were 4.63 and 4.04 years for the PTX and non‐PTX groups, respectively. A significant reduction in the risk of ACS (adjusted hazard ratio = 0.74, 95% confidence interval = 0.57–0.96) was observed for the ESRD patients after PTX.

Conclusions

Parathyroidectomy is associated with reduced risk of ACS in patients with ESRD.

From a national health insurance claims database, this study matched patients receiving dialysis who had a parathyroidectomy to patients who did not, using a propensity score method. They demonstrate that patients who had a parathyroidectomy were less likely to experience an acute coronary syndrome in the ensuing 4 years.

Effect of Tenapanor on Interdialytic Weight Gain in Patients on Hemodialysis

BACKGROUND AND OBJECTIVES

Interdialytic weight gain in patients on hemodialysis is associated with adverse cardiovascular outcomes and increased mortality. The degree of interdialytic weight gain is influenced by sodium intake. We evaluated the effects of tenapanor (AZD1722 and RDX5791), a minimally systemically available inhibitor of the sodium/hydrogen exchanger isoform 3, on interdialytic weight gain in patients with CKD stage 5D treated with hemodialysis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This phase 2, randomized, double-blind study (NCT01764854; conducted January to September of 2013) enrolled adults on maintenance hemodialysis with interdialytic weight gain ≥3.0% of postdialysis weight and ≥2 kg. Patients were randomly assigned (1:1) to receive tenapanor or placebo. The primary end point was change in mean interdialytic weight gain (percentage of baseline postdialysis weight) from baseline (mean across a 2-week run-in period) to week 4. In a subgroup of inpatients, 24-hour stool sodium and stool weight were assessed for 1 week.

RESULTS

Sixteen patients received 1 week of inpatient treatment (tenapanor, eight; placebo, eight), and 72 patients received 4 weeks of treatment in an outpatient setting (tenapanor, 37; placebo, 35; completers: tenapanor, 31; placebo, 33). In the outpatient cohort, no significant effect on interdialytic weight gain was detected; least squares mean changes in relative interdialytic weight gain from baseline to week 4 were tenapanor, -0.26% (95% confidence interval, -0.57% to 0.06%) and placebo, -0.23% (95% confidence interval, -0.54% to 0.07%; P=0.46). During week 1 (inpatient cohort only), compared with placebo, tenapanor treatment resulted in higher stool sodium content (mean [±SD]: tenapanor, 36.6 [±21.8] mmol/d; placebo, 2.8 [±2.7] mmol/d; P<0.001) and higher stool weight (tenapanor, 172.5 [±68.1] g/d; placebo, 86.3 [±30.0] g/d; P<0.01). A similar safety profile was observed across treatment groups with the exception of diarrhea, which occurred more frequently with tenapanor treatment.

CONCLUSIONS

Tenapanor treatment increased stool sodium and weight over placebo in patients undergoing hemodialysis. However, over 4 weeks of treatment, there was no difference in interdialytic weight gain between patients treated with tenapanor and those receiving placebo.

Predialysis hypotension is not a predictor for mortality in long-term hemodialysis patients: insight from a single-center observational study

Introduction

Predialysis hypotension has been noted to be a predictor of mortality in hemodialysis (HD) patients. Previous studies evaluating the impact of predialysis hypotension on the mortality of HD patients did not exclude patients with diabetes mellitus (DM) or cardiovascular disease.

Methods

Eight hundred and sixty-six patients on maintenance HD were recruited. Clinical parameters were recorded and subjected to the analysis of predictors of predialysis hypotension and mortality.

Results

Multivariate logistic regression analyses indicated that DM (odds ratio [OR]: 0.439, P=0.002), hypertension history (OR: 0.634, P=0.022), Kt/V Daugirdas (OR: 2.545, P=0.001), anuria (OR: 2.313, P=0.002), serum phosphate (OR: 0.833, P=0.010), and serum triglyceride (OR: 1.002, P=0.012) were associated with predialysis hypotension. Multivariate Cox regression analysis showed that age (P<0.001), male sex (P=0.029), anuria (P=0.004), and DM (P=0.011) were associated with higher probability of 24- and 36-month mortality. Predialysis hypotension was not associated with higher probability of 12-, 24-, and 36-month mortality.

Conclusion

Predialysis hypotension is not a predictor of 12-, 24-, and 36-month survival in patients without DM and with higher dialysis adequacy.

Rapid ultrafiltration rates and outcomes among hemodialysis patients: re-examining the evidence base

PURPOSE OF REVIEW

This review critically summarizes the evidence linking ultrafiltration rates to adverse outcomes among hemodialysis patients and provides research recommendations to address knowledge gaps.

RECENT FINDINGS

Growing evidence suggests that fluid-related factors play important roles in hemodialysis patient outcomes. Ultrafiltration rate - the rate of fluid removal during hemodialysis - is one such factor. Existing observational data suggest a robust association between greater ultrafiltration rates and adverse cardiovascular outcomes, and such findings are supported by plausible physiologic rationale. Potential mechanistic pathways include ultrafiltration-related ischemia to the heart, brain, and gut, and volume overload-precipitated cardiac stress from reactive measures to ultrafiltration-induced hemodynamic instability. Inter-relationships among ultrafiltration rates and other fluid measures, such as interdialytic weight gain and chronic volume expansion, render the specific role of ultrafiltration rates in adverse outcomes difficult to study. Randomized trials must be conducted to confirm epidemiologic findings and examine the effect of ultrafiltration rate reduction on clinical and patient-centered outcomes.

SUMMARY

Compelling observational data demonstrate an association between more rapid ultrafiltration rates and adverse clinical outcomes. Before translating these findings into clinical practice, randomized trials are needed to verify observational data results and to identify effective strategies to mitigate ultrafiltration-related risk.

Ultrafiltration Rates and the Quality Incentive Program: Proposed Measure Definitions and Their Potential Dialysis Facility Implications

BACKGROUND AND OBJECTIVES

Rapid ultrafiltration rates are associated with adverse outcomes among patients on hemodialysis. The Centers for Medicare and Medicaid Services is considering an ultrafiltration rate quality measure for the ESRD Quality Incentive Program. Two measure developers proposed ultrafiltration rate measures with different selection criteria and specifications. We aimed to compare the proposed ultrafiltration rate measures and quantify dialysis facility operational burden if treatment times were extended to lower ultrafiltration rates.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data were taken from the 2012 database of a large dialysis organization. Analyses of the Centers for Medicare and Medicaid Services measure considered 148,950 patients on hemodialysis, and analyses of the Kidney Care Quality Alliance measure considered 151,937 patients. We described monthly patient and facility ultrafiltration rates and examined differences in patient characteristics across ultrafiltration rate thresholds and differences in facilities across ultrafiltration rate measure scores. We computed the additional treatment time required to lower ultrafiltration rates <13 ml/h per kilogram.

RESULTS

Ultrafiltration rates peaked in winter and nadired in summer. Patients with higher ultrafiltration rates were younger; more likely to be women, nonblack, Hispanic, and lighter in weight; and more likely to have histories of heart failure compared with patients with lower ultrafiltration rates. Facilities had, on average, 20.8%±10.3% (July) to 22.8%±10.6% (February) of patients with ultrafiltration rates >13 ml/h per kilogram by the Centers for Medicare and Medicaid Services monthly measure. Facilities had, on average, 15.8%±8.2% of patients with ultrafiltration rates ≥13 ml/h per kilogram by the Kidney Care Quality Alliance annual measure. Larger facilities (>100 patients) would require, on average, 33 additional treatment hours per week to lower all facility ultrafiltration rates <13 ml/h per kilogram when total treatment time is capped at 4 hours.

CONCLUSIONS

Ultrafiltration rates vary seasonally and across clinical subgroups. Extension of treatment time as a strategy to lower ultrafiltration rates may pose facility operational challenges. Prospective studies of ultrafiltration rate threshold implementation are needed.

Are Diuretics Underutilized in Dialysis Patients?

While oral diuretics are commonly used in patients with chronic kidney disease for the management of volume and blood pressure, they are often discontinued upon initiation of dialysis. We suggest that diuretics are considerably underutilized in peritoneal dialysis and haemodialysis patients despite numerous potential benefits and few side effects. Moreover, when diuretics are used, optimal doses are not always prescribed. In peritoneal dialysis, the use of diuretics can improve volume status and minimize the need for higher glucose-containing solutions. In patients on haemodialysis, diuretics can help lessen interdialytic weight gain, resulting in decreased ultrafiltration rates and fewer episodes of intradialytic hypotension. This paper will review the mechanism of action of diuretics in patients with renal insufficiency, quantify the risk of side effects and elaborate on the potential advantages of diuretic use in peritoneal dialysis and hemodialysis patients with residual kidney function.

Prevalence of intradialytic hypotension, clinical symptoms and nursing interventions--a three-months, prospective study of 3818 haemodialysis sessions

Background

Intradialytic hypotension (IDH) is considered one of the most frequent complications of haemodialysis with an estimated prevalence of 20–50 %, but studies investigating its exact prevalence are scarce. A complicating factor is that several definitions of IDH are used. The goal of this study was, to assess the prevalence of IDH, primarily in reference to the European Best Practice Guideline (EBPG) on haemodynamic instability: A decrease in systolic blood pressure (SBP) ≥20 mmHg or in mean arterial pressure (MAP) ≥10 mmHg associated with a clinical event and the need for nursing intervention.

Methods

During 3 months we prospectively collected haemodynamic data, clinical events, and nursing interventions of 3818 haemodialysis sessions from 124 prevalent patients who dialyzed with constant ultrafiltration rate and dialysate conductivity. Patients were considered as having frequent IDH if it occurred in >20 % of dialysis sessions.

Results

Decreases in SBP ≥20 mmHg or MAP ≥10 mmHg occurred in 77.7 %, clinical symptoms occurred in 21.4 %, and nursing interventions were performed in 8.5 % of dialysis sessions. Dialysis hypotension according to the full EBPG definition occurred in only 6.7 % of dialysis sessions. Eight percent of patients had frequent IDH.

Conclusions

The prevalence of IDH according to the EBPG definition is low. The dominant determinant of the EBPG definition was nursing intervention since this was the component with the lowest prevalence. IDH seems to be less common than indicated in the literature but a proper comparison with previous studies is complicated by the lack of a uniform definition.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-016-0231-9) contains supplementary material, which is available to authorized users.

Hemodialysis in children with ventriculoperitoneal shunts: prevalence, management and outcomes

BACKGROUND

Hemodialysis (HD) in children with a concomitant ventriculoperitoneal shunt (VPS) is rare. Registry data suggest that peritoneal dialysis with a VPS is safe, but little is known about HD in the presence of a VPS.

METHODS

We performed a 10-year survey to determine the prevalence of a VPS, complications and outcome in children with a VPS on HD in 15 dialysis units from the 13 countries participating in the European Pediatric Dialysis Working Group.

RESULTS

Eleven cases of HD with a VPS were reported (prevalence 1.33 %; 328 patient-months) and compared with prospective Registry data. The median age at start of dialysis was 9.6 [inter-quartile range (IQR) 1.0-15.0] years and median HD vintage was 2.4 (IQR 1.7-3.0) years. Dialysis was performed through a central venous line (CVL) and through an arteriovenous fistula in six and five children, respectively. Three CVL infections occurred in two children, but these children did not develop VPS infections or meningitis. Symptoms of hemodynamic instability were reported in six (55 %) children at least once per week, with hypotension or hypertension occurring in four of these children and nausea, vomiting and headaches occurring in two; four other children reported less frequent symptoms. Seizures on dialysis occurred in two children, at a frequency of less than once per month, with one child also experiencing visual disturbances. During follow-up (median 4.0; IQR 0.38-7.63 years), three children remained on HD and eight had a functioning transplant. No patients were switched to PD.

CONCLUSIONS

Hemodialysis in children with a VPS is safe, but associated with frequent symptoms of hemodynamic instability. No episodes of VPS infection or meningitis were seen among the children in the survey, not even in those with CVL sepsis.

A Higher Cardiothoracic Ratio Is Associated with 2-Year Mortality after Hemodialysis Initiation

A high cardiothoracic ratio (CTR) is indicative of a cardiac disorder. However, few reports have revealed an association between the CTR and mortality in patients starting hemodialysis (HD).

METHODS

Patients with HD initiation (n = 387; mean age, 66.7 ± 12.7 years) were divided into the following three groups according to their CTR at HD initiation: CTR <50%, 50% ≤ CTR < 55%, and CTR ≥55%. Kaplan-Meier analysis was performed to compare 2-year all-cause mortality among these groups. Furthermore, we investigated the factors affecting their 2-year mortality using a Cox proportional hazard regression analysis.

RESULTS

Sixty-five patients (17%) died within 2 years after HD initiation. Kaplan-Meier analysis showed that patients with CTR ≥55% had a higher mortality rate than those in the other groups. Cox proportional hazard regression analysis was performed using parameters with p values <0.1 among these three groups [sex, age, presence or absence of ischemic heart disease, hemoglobin levels, serum albumin levels, CTR, body mass index (BMI)] and confounding factors [presence or absence of diabetes mellitus, and estimated glomerular filtration rate (eGFR)]. Age, eGFR, BMI, and CTR ≥55% at HD initiation were identified as factors influencing 2-year mortality.

CONCLUSION

CTR >55% is one of the most important independent factors to affect 2-year all-cause mortality. Thus, confirming the cardiac condition of patients at HD initiation with a CTR >55% may improve their survival.

Intradialytic Blood Pressure Abnormalities: The Highs, The Lows and All That Lies Between

BACKGROUND

Frequent blood pressure (BP) measurements are necessary to ensure patient safety during hemodialysis treatments. Intradialytic BPs are not optimal tools for hypertension diagnosis and cardiovascular risk stratification, but they do have critical clinical and prognostic significance. We present evidence associating intradialytic BP phenomena including fall, rise and variability with adverse clinical outcomes and review related pathophysiologic mechanisms and potential management strategies.

SUMMARY

Observational studies demonstrate associations between intradialytic hypotension, hypertension and BP variability and mortality. Lack of consensus regarding diagnostic criteria has hampered data synthesis, and prospective studies investigating optimal management strategies for BP phenomena are lacking. Mechanistic data suggest that cardiac, gut, kidney and brain ischemia may lie on the causal pathway between intradialytic hypotension and mortality, and endothelial cell dysfunction, among other factors, may be an important mediator of intradialytic hypertension and adverse outcomes. These plausible pathophysiologic links present potential therapeutic targets for future inquiry. The phenomenon of intradialytic BP variability has not been adequately studied, and practical clinical measures and treatment strategies are lacking.

KEY MESSAGES

Intradialytic BP phenomena have important prognostic bearing. Clinical practice guidelines for both intradialytic hypotension and hypertension exist, but their underlying evidence is weak overall. Further research is needed to develop consensus diagnostic criteria for intradialytic hypotension, hypertension and BP variability and to elucidate optimal treatment and prevention strategies for each BP manifestation.

Frequency of intradialytic hypotensive episodes: old problem, new insights

Symptomatic intradialytic hypotension (IDH) continues to be an important complication of hemodialysis treatment. There is some evidence that besides an IDH episode, repeated episodes could represent an even more important independent risk factor for mortality in hemodialysis patients. A retrospective cross-sectional study was performed to study 18 dialysis treatments in 43 patients during 6 weeks. Relationships of IDH episodes with baseline variables were examined using a Poisson regression model (generalized linear model). IDH was frequent (93% of patients) and highly variable by patient (0%-100%). Multivariate analysis showed that patients who experienced frequent hypotensive episodes had a lower dry weight (90% confidence interval [CI]: 0.95-0.99), higher phosphorus levels (90% CI: 1.07-1.47), greater prevalence of diabetes mellitus (90% CI: 1.11-2.71), and hypertension (90% CI: 1.04-2.45). Dry weight, hypertension, and phosphorus levels are modifiable risk factors to possibly reduce the rate of IDH episodes. The potential protective role of phosphorus warrants further investigation.

A retrospective, longitudinal study estimating the association between interdialytic weight gain and cardiovascular events and death in hemodialysis patients

BACKGROUND

Greater interdialytic weight gain (IDWG) is associated with risk of all-cause mortality and hospitalization. Dialysis patients are also at greater risk of cardiovascular (CV) events than patients without kidney disease. This retrospective study examined the potential association between IDWG and specific types of CV events.

METHODS

Data were obtained from United States Renal Data System claims and the electronic health records of Medicare patients who initiated hemodialysis between 01 January 2007 and 31 December 2008 at a large dialysis organization. Absolute IDWG was defined as predialysis weight minus postdialysis weight from the prior treatment, and relative IDWG was calculated as percentage of postdialysis weight with mean values for each, calculated over dialysis days 91 to 180. Patient outcomes were considered beginning on day 181, continuing until death, discontinuation of care, censoring, or study end (31 December 2009). Outcomes included all-cause mortality, CV mortality, hospitalization for nonfatal heart failure/volume overload, hospitalization for nonfatal myocardial infarction, MACE (a composite measure of nonfatal myocardial infarction, nonfatal ischemic stroke, or CV death), and MACE+ (events comprising MACE as well as arrhythmia, nonfatal hemorrhagic stroke, or hospitalization for heart failure). Associations between IDWG and outcomes over the exposure period were estimated using proportional hazards regression and adjusted for baseline characteristics.

RESULTS

39,256 patients qualified for analysis. In general, associations of relative IDWG with outcomes were more potent, consistent, and monotonic than those for absolute IDWG. Relative IDWG > 3.5 % body weight was independently associated with all outcomes studied: point estimates ranged from 1.18 (myocardial infarction) to 1.26 (CV mortality) and were consistent among patients with and without diabetes, and with and without baseline heart failure. Absolute IDWG > 3 kg was associated with outcomes other than myocardial infarction: point estimates ranged from 1.11 (MACE) to 1.20 (heart failure).

CONCLUSIONS

Greater IDWG is associated with an increased risk of CV morbid events. Strategies that mitigate IDWG may improve CV health and survival among hemodialysis patients.