Red blood cell distribution width and mortality and hospitalizations in peritoneal dialysis patients

BACKGROUND

Red blood cell distribution width (RDW) is found to be associated with different types of anemia and has recently been studied as a prognostic marker of mortality in hemodialysis patients. However, the relationship of RDW with mortality and hospitalization rate in peritoneal dialysis (PD) patients is less known.

METHODS

Among 14 323 incident PD patients between 2007 and 2011 in the USA, we examined the relationship of baseline and time-varying RDW with the risk of mortality and time to first hospitalization using adjusted Cox models. In addition, we examined the relationship of baseline RDW and hospitalization rate using an adjusted negative-binomial regression model. Sensitivity analyses included competing risk models and subgroup analyses.

RESULTS

The study population comprised patients 56 ± 16 years of age, including 43% females, 23% African Americans and 62% diabetics, with a mean RDW of 15.3 ± 1.6%. In models adjusted for clinical characteristics and laboratory parameters, RDW exhibited an incremental relationship with the mortality risk, where RDW ≥16.5% had a 40% and 69% higher risk of death in baseline and time-varying analyses, respectively, compared with an RDW of 14.5-15.5%. Moreover, higher baseline RDW ≥16.5% was also associated with a higher risk of time to first hospitalization {hazard ratio 1.22 [95% confidence interval (CI) 1.14-1.29]} and a higher rate of hospitalizations [incidence rate ratio 1.16 (95% CI 1.09-1.23)]. These results were consistent across numerous sensitivity analyses.

CONCLUSIONS

Higher RDW is associated with a higher risk of mortality and hospitalizations among incident PD patients. Further studies are needed to examine the mechanism behind RDW and adverse outcomes.

Transplantation of kidneys from hepatitis C-infected donors to hepatitis C-negative recipients: Single center experience

Our aim was to evaluate the safety of transplanting kidneys from HCV-infected donors in HCV-uninfected recipients. Data collected from 53 recipients in a single center, observational study included donor and recipient characteristics, liver and kidney graft function, new infections and de novo donor-specific antibodies and renal histology. Treatment with a direct-acting antiviral regimen was initiated when HCV RNA was detected. The mean ± SD age of recipients was 53 ± 11 years, 34% were female, 19% and 79% of recipients were white and African American, respectively. The median and interquartile range (IQR) time between transplant and treatment initiation was 76 (IQR: 68-88) days. All 53 recipients became viremic (genotype: 1a [N = 34], 1b [N = 1], 2 [N = 3], and 3 [N = 15]). The majority (81%) of recipients did not experience clinically significant increases (>3 times higher than upper limit of the normal value) in aminotransferase levels and their HCV RNA levels were in the 5 to 6 log range. One patient developed fibrosing cholestatic hepatitis with complete resolution. All recipients completed antiviral treatment and 100% were HCV RNA-negative and achieved 12-week sustained virologic response. The estimated GFRs at end of treatment and 12-week posttreatment were 67 ± 21 mL/min/1.73 m² and 67 ± 17 mL/min/1.73 m² , respectively. Four recipients developed acute rejection. Kidney transplantation from HCV-infected donors to HCV-negative recipients should be considered in all eligible patients.

National Trends in Utilization and 1-Year Outcomes with Transplantation of HCV-Viremic Kidneys

BACKGROUND

Recent pilot trials have demonstrated the safety of transplanting HCV-viremic kidneys into HCV-seronegative recipients. However, it remains unclear if allograft function is impacted by donor HCV-viremia or recipient HCV-serostatus.

METHODS

We used national United States registry data to examine trends in HCV-viremic kidney use between 4/1/2015 and 3/31/2019. We applied advanced matching methods to compare eGFR for similar kidneys transplanted into highly similar recipients of kidney transplants.

RESULTS

Over time, HCV-seronegative recipients received a rising proportion of HCV-viremic kidneys. During the first quarter of 2019, 200 HCV-viremic kidneys were transplanted into HCV-seronegative recipients, versus 69 into HCV-seropositive recipients, while 105 HCV-viremic kidneys were discarded. The probability of HCV-viremic kidney discard has declined over time. Kidney transplant candidates willing to accept a HCV-seropositive kidney increased from 2936 to 16,809 from during this time period. When transplanted into HCV-seronegative recipients, HCV-viremic kidneys matched to HCV-non-viremic kidneys on predictors of organ quality, except HCV, had similar 1-year eGFR (66.3 versus 67.1 ml/min per 1.73 m², P=0.86). This was despite the much worse kidney donor profile index scores assigned to the HCV-viremic kidneys. Recipient HCV-serostatus was not associated with a clinically meaningful difference in 1-year eGFR (66.5 versus 71.1 ml/min per 1.73 m², P=0.056) after transplantation of HCV-viremic kidneys.

CONCLUSIONS

By 2019, HCV-seronegative patients received the majority of kidneys transplanted from HCV-viremic donors. Widely used organ quality scores underestimated the quality of HCV-viremic kidneys based on 1-year allograft function. Recipient HCV-serostatus was also not associated with worse short-term allograft function using HCV-viremic kidneys.

Association of the frequency of pre-end-stage renal disease medical care with post-end-stage renal disease mortality and hospitalization

Background

Previous studies have demonstrated that early pre-end-stage renal disease (ESRD) nephrology care could improve postdialysis prognosis. However, less is known about the specific types of interventions responsible for the improved outcomes. We hypothesized that more frequent predialysis laboratory testing is associated with better postdialysis outcomes in incident ESRD patients.

Methods

In all, 23 089 patients with available outpatient laboratory tests performed during the 2-year predialysis (i.e. prelude) period were identified from a total of 52 172 American veterans with chronic kidney disease (CKD) transitioning to dialysis between October 2007 and September 2011. The associations between the frequency of combined laboratory tests, including serum creatinine, serum potassium and hemoglobin (test trio), with postdialysis mortality and hospitalization were examined in multivariable adjusted Cox and logistic regression models.

Results

When entering the 2-year prelude period, the mean age (Standard Deviation) of the patients was 66.2 (SD 11.3) years and the mean estimated glomerular filtration rate was 46.8 (SD 23.9) mL/min/1.73 m2. In all, 14% of patients had the test trio performed less than twice in 24 months and 8.9% had the trio measured more often than every other month. Over a 2.5-year median postdialysis follow-up period, 15 303 (66.3%) patients died (mortality rate 260/1000 patient-years). The adjusted hazard ratio of all-cause mortality and adjusted odds ratio of the composite of hospitalization or death associated with lab testing done >12/24 months compared with 2-≤4/24 months were 0.68 [95% confidence interval (CI) 0.65-0.73] and 0.70 (95% CI 0.62-0.79), respectively.

Conclusions

More frequent laboratory testing in patients with advanced CKD is associated with better clinical outcomes after dialysis. Further examination in clinical trials is needed before the implementation of more frequent laboratory testing in clinical practice.

Prognostic significance of pre-end-stage renal disease serum alkaline phosphatase for post-end-stage renal disease mortality in late-stage chronic kidney disease patients transitioning to dialysis

Background

Higher serum alkaline phosphatase (ALP) levels have been associated with excess mortality in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD) and end-stage renal disease (ESRD). However, little is known about the impact of late-stage NDD-CKD ALP levels on outcomes after dialysis initiation.

Methods

Among 17 732 US veterans who transitioned to dialysis between October 2007 and September 2011, we examined the association of serum ALP levels averaged over the last 6 months of the pre-ESRD transition period ('prelude period') with all-cause, cardiovascular and infection-related mortality following dialysis initiation, using Cox (for all-cause mortality) and competing risk (for cause-specific mortality) regressions adjusted for demographics, comorbidities, medications, estimated glomerular filtration rate and serum albumin levels over the 6-month prelude period, and vascular access type at dialysis initiation.

Results

During a median follow-up of 2.0 (interquartile range, 1.1-3.2) years following dialysis initiation, a total of 9196 all-cause deaths occurred. Higher ALP levels were incrementally associated with higher all-cause, cardiovascular and infection-related mortality. Compared with patients in the lowest ALP quartile (<66.0 U/L), those in the highest quartile (≥111.1 U/L) had multivariable-adjusted hazard/subhazard ratios (95% confidence interval) of 1.42 (1.34-1.51), 1.43 (1.09-1.88) and 1.39 (1.09-1.78) for all-cause, cardiovascular and infection-related mortality, respectively. The associations remained consistent in various subgroups and after further adjustment for liver enzymes, serum phosphorus and intact parathyroid hormone levels.

Conclusions

Higher pre-ESRD serum ALP levels are independently associated with higher post-ESRD mortality risk. Further studies are warranted to determine if interventions that lower pre-ESRD ALP levels reduce mortality in incident dialysis patients.

History of posttraumatic stress disorder and outcomes after kidney transplantation

A history of posttraumatic stress disorder (PTSD), if uncontrolled, represents a contraindication for kidney transplantation. However, no previous large study has assessed the association between pretransplant history of PTSD and posttransplantation outcomes. We examined 4479 US veterans who had undergone transplantation. The diagnosis of history of PTSD was based on a validated algorithm. Measured covariates were used to create a matched cohort (n = 560). Associations between pretransplant PTSD and death with functioning graft, all-cause death, and graft loss were examined in survival models. Posttransplant medication nonadherence was assessed using proportion of days covered (PDC). From among 4479 veterans, 282 (6.3%) had a history of PTSD. The mean age ± standard deviation (SD) of the cohort at baseline was 61 ± 11 years, 91% were male, and 66% and 28% of patients were white and African American, respectively. Compared to patients without a history of PTSD, patients with a history of PTSD had a similar risk of death with a functioning graft (subhazard ratio [SHR] 0.97, 95% confidence interval [CI] 0.61-1.54), all-cause death (1.05, 0.69-1.58), and graft loss (1.09, 0.53-2.26). Moreover, there was no difference in immunosuppressive drug PDC in patients with and without a history of PTSD (PDC: 98 ± 4% vs 99 ± 3%, P = .733 for tacrolimus; PDC: 99 ± 4% vs 98 ± 7%, P = .369 for mycophenolic acid). A history of PTSD in US veterans with end-stage renal disease should not on its own preclude a veteran from being considered for transplantation.

Association between malnutrition-inflammation score and risk of subsequent self-reported bone fractures in prevalent kidney transplant recipients

Chronic inflammation and protein energy wasting (PEW) syndrome are common in kidney transplant recipients (KTR). The presence of inflammation and PEW syndrome can directly affect bone resorption and bone formation, leading to bone loss and fractures. We showed PEW is independently associated with new clinically detected bone fractures in prevalent KTR.

INTRODUCTION

Kidney transplant recipients (KTR) have a 4-fold higher risk of fracture compared to the general population. Chronic inflammation and PEW syndrome are common in KTR and are associated with poor outcomes. We hypothesized that the Malnutrition-Inflammation Score (MIS), a validated measure of PEW, is associated with higher risk of bone fractures in KTR.

METHODS

This prospective cohort study included 839 prevalent KTR from a Central European academic center. MIS, a semiquantitative instrument of PEW, was calculated at the study entry. Self-reported history of fractures was recorded during the 2-year follow-up period. The association between MIS and bone fractures was examined in logistic regression analyses with adjustment for age, gender, eGFR, smoking habits, history of pre-transplant bone fractures, and acute rejection.

RESULTS

Mean age was 51 ± 13 years, and 56% of patients were males with median (interquartile range) transplant vintage 69 (38-112) months, estimated glomerular filtration rate 55 ± 21 ml/min/1.73 m², and calculated MIS 3 (2-4) at enrollment. Fifty-five (7%) patients experienced self-reported bone fractures during the 2-year follow-up period. Higher MIS score showed linear association with increased risk of fracture. Each one-point higher MIS was associated with 23% higher risk of bone fractures (odds ratio (OR) and 95% CI 1.23, 1.12-1.34), which remained significant after multivariable adjustments (OR 1.17, 95% CI 1.06-1.29).

CONCLUSION

The MIS is independently associated with new clinically detected bone fractures in prevalent KTR.

Association of Pretransplant Renal Function With Liver Graft and Patient Survival After Liver Transplantation in Patients With Nonalcoholic Steatohepatitis

Nonalcoholic steatohepatitis (NASH) is one of the top 3 indications for liver transplantation (LT) in Western countries. It is unknown whether renal dysfunction at the time of LT has any effect on post-LT outcomes in recipients with NASH. From the United Network for Organ Sharing-Standard Transplant Analysis and Research data set, we identified 4088 NASH recipients who received deceased donor LT. We divided our recipients a priori into 3 categories: group 1 with estimated glomerular filtration rate (eGFR) <30 mL/minute/1.73 m² at the time of LT and/or received dialysis within 2 weeks preceding LT (n = 937); group 2 with recipients who had eGFR ≥30 mL/minute/1.73 m² and who did not receive renal replacement therapy prior to LT (n = 2812); and group 3 with recipients who underwent simultaneous liver-kidney transplantation (n = 339). We examined the association of pretransplant renal dysfunction with death with a functioning graft, all-cause mortality, and graft loss using competing risk regression and Cox proportional hazards models. The mean ± standard deviation age of the cohort at baseline was 58 ± 8 years, 55% were male, 80% were Caucasian, and average exception Model for End-Stage Liver Disease score was 24 ± 9. The median follow-up period was 5 years (median, 1816 days; interquartile range, 1090-2723 days). Compared with group 1 recipients, group 2 recipients had 19% reduced trend for risk for death with a functioning graft (subhazard ratio [SHR], 0.81; 95% confidence interval [CI], 0.64-1.02) and similar risk for graft loss (SHR, 1.25; 95% CI, 0.59-2.62), whereas group 3 recipients had similar risk for death with a functioning graft (SHR, 1.23; 95% CI, 0.96-1.57) and graft loss (SHR, 0.18; 95% CI, 0.02-1.37) using an adjusted competing risk regression model. In conclusion, recipients with preserved renal function before LT showed a trend toward lower risk of death with a functioning graft compared with SLKT recipients and those with pretransplant severe renal dysfunction in patients with NASH.

Predialysis coronary revascularization and postdialysis mortality

Objectives

Coronary artery bypass grafting (CABG) is associated with better survival than percutaneous coronary intervention (PCI) in patients with mild-to-moderate chronic kidney disease (CKD) and End-Stage Renal Disease (ESRD). However, the optimal strategy for coronary artery revascularization in advanced CKD patients who transition to ESRD is unclear.

Methods

We examined a contemporary national cohort of 971 US veterans with incident ESRD, who underwent first CABG or PCI up to 5 years prior to dialysis initiation. We examined the association of a history of CABG versus PCI with all-cause mortality following transition to dialysis, using Cox proportional hazards models adjusted for time between procedure and dialysis initiation, socio-demographics, comorbidities and medications.

Results

582 patients underwent CABG and 389 patients underwent PCI. The mean age was 66±8 years, 99% of patients were male, 79% were white, 19% were African Americans, and 84% were diabetics. The all-cause post-dialysis mortality rates after CABG and PCI were 229/1000 patient-years (PY) [95% CI: 205-256] and 311/1000PY [95% CI: 272-356], respectively. Compared to PCI, patients who underwent CABG had 34% lower risk of death [multivariable adjusted Hazard Ratio (95% CI) 0.66 (0.51-0.86), p=0.002] after initiation of dialysis. Results were similar in all subgroups of patients stratified by age, race, type of intervention, presence/absence of myocardial infarction, congestive heart failure and diabetes.

Conclusion

CABG in advanced CKD patients was associated lower risk of death after initiation of dialysis compared to PCI.

Association Between Serum Prealbumin Level and Outcomes in Prevalent Kidney Transplant Recipients

OBJECTIVE(S)

Prealbumin, a transport protein mostly synthesized in the liver, is a marker of nutrition. Although decreased prealbumin levels are associated with increased mortality in end-stage kidney disease patients, its association with mortality in kidney transplant recipients remains unknown. We evaluated the association between prealbumin levels and outcomes in kidney transplant recipients.

DESIGN

This was a prospective prevalent cohort study. This study included 991 kidney transplant recipients enrolled from December 31, 2006, to December 31, 2007, and followed over a 6-year period. Sociodemographic, past medical history, clinical, and laboratory data were collected at the study entry. Associations between prealbumin levels and death with functioning graft, all-cause mortality, and graft loss were examined using survival models.

RESULTS

Serum prealbumin levels showed significant negative correlation with estimated glomerular filtration rate (R = -0.28; P < .001) and high-sensitive C-reactive protein (R = -0.24; P < .001). Each 5 mg/dL lower serum prealbumin level was associated with 20% higher risk of death with functioning graft (subdistribution hazard ratio [95% confidence interval]: 1.20 [1.08-1.35]; P = .001), which persisted after multivariable adjustments (subdistribution hazard ratio [95% confidence interval]: 1.13 [1.00-1.28]; P = .039). Qualitatively similar trend was observed in all-cause mortality; however, there was no association between prealbumin levels and graft loss.

CONCLUSION(S)

Lower serum prealbumin level is associated with increased risk of death with functioning graft in prevalent kidney transplant recipients.

Vancomycin-Associated Acute Kidney Injury in a Large Veteran Population

BACKGROUND

To determine the association of vancomycin with acute kidney injury (AKI) in relation to its serum concentration value and to examine the risk of AKI in patients treated with vancomycin when compared with a matched cohort of patients receiving non-glycopeptide antibiotics (linezolid/daptomycin).

METHODS

From a cohort of > 3 million US veterans with baseline estimated glomerular filtration rate ≥60 mL/min/1.73 m2, we identified 33,527 patients who received either intravenous vancomycin (n = 22,057) or non-glycopeptide antibiotics (linezolid/daptomycin, n = 11,470). We examined the association of the serum trough vancomycin level recorded within the first 48 h of administration with subsequent AKI in all patients treated with vancomycin and association of vancomycin vs. non-glycopeptide antibiotics use with the risk of incident AKI.

RESULTS

The overall multivariable adjusted ORs of AKI stages 1, 2, and 3 in patients on vancomycin vs. non-glycopeptides were 1.1 (1.1-1.2), 1.2 (1-1.4), and 1.4 (1.1-1.7), respectively. When examined in strata divided by vancomycin trough level, the odds of AKI were similar or lower in patients receiving vancomycin compared to non-glycopeptide antibiotics as long as serum vancomycin levels were ≤20 mg/L. However, in patients with serum vancomycin levels > 20 mg/L, the ORs of AKI stages 1, 2, and 3 in patients on vancomycin vs. non-glycopeptide antibiotics were 1.5 (1.4-1.7), 1.9 (1.5-2.3), and 2.7 (2-3.5), respectively.

CONCLUSIONS

Vancomycin use is associated with a higher risk of AKI when serum levels exceed > 20 mg/L.

Mean Corpuscular Volume and Mortality in Incident Hemodialysis Patients

BACKGROUND/AIMS

Anemia is common in patients with advanced chronic kidney disease (CKD). A proportion of patients present with macrocytic anemia, manifested by elevated mean corpuscular volume (MCV), which has been associated with worse outcomes in CKD patients. However, it is unknown whether elevated MCV is associated with higher mortality risk in incident hemodialysis (HD) patients.

METHODS

This retrospective observational cohort study examined all-cause, cardiovascular, and infectious mortality associations with both baseline and time-varying MCV in 109,501 incident HD patients using Cox proportional hazards models with 3 levels of hierarchical multivariable adjustment. Odds ratios of high versus low baseline MCV were evaluated using logistic regression.

RESULTS

The mean age of patients was 65 ± 15 (standard deviation) years and the cohort was 44% female, 58% diabetic, and 31% African American. Higher MCV was associated with older age, female sex, non-Hispanic White race-ethnicity, alcohol consumption, and having a decreased albumin or protein intake. Patients with higher MCV levels (> 98 fL) had a higher all-cause, cardiovascular, and infectious mortality risk in both baseline and time varying models, and across all levels of adjustment. In the fully adjusted models, compared to a reference of MCV 92-< 94 fL, patients with a baseline MCV > 100+ fL had a 28% higher risk of all-cause mortality (hazard ratio [HR] 1.28, 95% CI 1.22-1.34), 27% higher risk of cardiovascular mortality (HR 1.27, 95% CI 1.18-1.36), and 18% higher risk of infectious mortality (HR 1.18, 95% CI 1.02-1.38). Associations of higher MCV with these adverse outcomes persisted across all examined subgroups of clinical characteristics.

CONCLUSIONS

Higher MCV was associated with higher all-cause, cardiovascular, and infectious mortality in HD patients. Further investigation is necessary to understand the underlying nature of the observed association.

Association of Chronic Insomnia With Mortality and Adverse Renal Outcomes

OBJECTIVE

To examine whether chronic insomnia is associated with an increased risk of adverse renal outcomes and all-cause mortality.

PATIENTS AND METHODS

We examined associations of chronic insomnia (defined as the presence of both International Classification of Diseases, Ninth Revision codes 307.42, 307.49, and 780.52 and long-term use of insomnia medications) with adverse renal outcomes (end-stage renal disease, incidence of estimated glomerular filtration rate [eGFR] ≤45 mL/min per 1.73 m², and eGFR slopes <-3.0 mL/min per 1.73 m² per year) and all-cause mortality in a national cohort of 1,639,090 US veterans by using Cox proportional hazards and logistic regression models with multivariable adjustments.

RESULTS

A total of 36,741 patients (2.24%) had chronic insomnia; 32,985 (89.8%) were male and 28,090 (76.5%) were white, with a mean baseline eGFR of 84.1±16.4 mL/min per 1.73 m². Chronic insomnia was associated with a significantly higher risk of eGFR 45 mL/min per 1.73 m² or less (multivariable-adjusted hazard ratio [HR], 1.39; 95% CI, 1.34-1.44; P<.001), and rapid loss of kidney function (odds ratio, 1.07; 95% CI, 1.03-1.12; P=.002), but not end-stage renal disease (HR, 1.25; 95% CI, 0.81-1.93; P=.32). Chronic insomnia was not associated with a higher risk of all-cause mortality (HR, 1.00; 95% CI, 0.97-1.03; P=.99).

CONCLUSION

Chronic insomnia is associated with a higher risk of development and progression of chronic kidney disease, but not ESRD. Further studies are needed to establish the underlying mechanisms of action and to determine whether treatment of insomnia could be beneficial to prevent deteriorating kidney function.

Association of Continuation of Statin Therapy Initiated Before Transition to Chronic Dialysis Therapy With Mortality After Dialysis Initiation

IMPORTANCE

De novo statin therapy in patients receiving chronic dialysis has failed to demonstrate cardiovascular (CV) protection in randomized clinical trials and thus is not recommended by current guidelines. However, current guidelines recommend the continuation of statin therapy if initiated before transition to dialysis.

OBJECTIVE

To investigate whether the continuation of statins from advanced chronic kidney disease into the dialysis therapy period is associated with improved survival.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of US veterans transitioning to dialysis between October 1, 2007, and March 30, 2014. Participants were 14 298 US veterans who were receiving statins during the 12-month period before transition to dialysis and survived the first year of dialysis. Data analysis was conducted between August 2, 2017, and June 28, 2018.

EXPOSURES

Patients were characterized as statin continuers (n = 11 936) if statin therapy was continued for at least 6 months during the first year after dialysis initiation and as statin discontinuers (n = 2362) if therapy with statins was stopped or no statin therapy was received in the year posttransition.

MAIN OUTCOMES AND MEASURES

Associations of statin continuation with 12-month all-cause mortality and CV mortality after 1 year of dialysis initiation were examined using Cox proportional hazards regression models adjusted for demographics and comorbidities.

RESULTS

The mean (SD) age of the cohort was 71 (10) years; the cohort was 96.7% (n = 13 828) male and 21.3% (n = 3043) African American, and 74.6% (n = 10 627) had diabetes. The 12-month all-cause mortality and CV mortality rates after 1 year of transition to dialysis were lower in statin continuers: deaths per 100 person-years were 21.9 (95% CI, 20.9-22.8) and 8.1 (95% CI, 7.5-8.6) in statin continuers vs 30.3 (95% CI, 27.8-32.8) and 9.8 (95% CI, 8.3-11.2) in statin discontinuers. Moreover, lower all-cause mortality and CV mortality risks with statin continuation persisted in adjusted analyses, with hazard ratios of 0.72 (95% CI, 0.66-0.79) and 0.82 (95% CI, 0.69-0.96), respectively. Associations were similar across subgroups, including age, race, and diabetes status.

CONCLUSIONS AND RELEVANCE

In this study, the continuation of statin therapy after transition to dialysis was associated with reduced all-cause mortality and CV mortality. The study findings suggest that future studies are needed to examine potential CV benefits of continuing statin therapy after dialysis initiation.

Development and Validation of Prediction Scores for Early Mortality at Transition to Dialysis

OBJECTIVE

To develop and validate a risk prediction model that would help individualize treatment and improve the shared decision-making process between clinicians and patients.

PATIENTS AND METHODS

We developed a risk prediction tool for mortality during the first year of dialysis based on pre-end-stage renal disease characteristics in a cohort of 35,878 US veterans with incident end-stage renal disease who transitioned to dialysis treatment between October 1, 2007, and March 31, 2014 and then externally validated this tool among 4284 patients in the Kaiser Permanente Southern California (KPSC) health care system who transitioned to dialysis treatment between January 1, 2007, and September 30, 2015.

RESULTS

To ensure model goodness of fit, 2 separate models were selected for patients whose last estimated glomerular filtration rate (eGFR) before dialysis initiation was less than 15 mL/min per 1.73 m² or 15 mL/min per 1.73 m² or higher. Model discrimination in the internal validation cohort of veterans resulted in C statistics of 0.71 (95% CI, 0.70-0.72) and 0.66 (95% CI, 0.65-0.67) among patients with eGFR lower than 15 mL/min per 1.73 m² and 15 mL/min per 1.73 m² or higher, respectively. In the KPSC external validation cohort, the developed risk score exhibited C statistics of 0.77 (95% CI, 0.74-0.79) in men and 0.74 (95% CI, 0.71-0.76) in women with eGFR lower than 15 mL/min per 1.73 m² and 0.71 (95% CI, 0.67-0.74) in men and 0.67 (95% CI, 0.62-0.72) in women with eGFR of 15 mL/min per 1.73 m² or higher.

CONCLUSION

A new risk prediction tool for mortality during the first year after transition to dialysis (available at www.DialysisScore.com) was developed in the large national Veterans Affairs cohort and validated with good performance in the racially, ethnically, and gender diverse KPSC cohort. This risk prediction tool will help identify high-risk populations and guide management strategies at the transition to dialysis.

Achieving Sustained Virological Response in Liver Transplant Recipients With Hepatitis C Decreases Risk of Decline in Renal Function

The effect of antiviral therapy (AVT) on kidney function in liver transplantation (LT) recipients has not been well described despite known association of hepatitis C virus (HCV) infection with chronic kidney disease (CKD). We compared the incidence of CKD and end-stage renal disease (ESRD) in 204 LT recipients with HCV based on treatment response to AVT. The mean estimated glomerular filtration rate (eGFR) at baseline (3 months after LT) was similar in the sustained virological response (SVR; n = 145) and non-SVR group (n = 59; 69 ± 21 versus 65 ± 33 mL/minute/1.73 m² ; P = 0.27). In the unadjusted Cox proportional regression analysis, the presence of SVR was associated with an 88% lower risk of CKD (hazard ratio, 0.12; 95% confidence interval [CI], 0.05-0.31) and 86% lower risk of ESRD (odds ratio, 0.14; 95% CI, 0.05-0.35). Similar results were found after adjusting for propensity score and time-dependent Cox regression analyses. The estimated slopes of eGFR based on a 2-stage mixed model of eGFR were calculated. Patients with SVR had a less steep slope in eGFR (-0.60 mL/minute/1.73 m² /year; 95% CI, -1.50 to 0.30; P = 0.190) than recipients without SVR (-2.53 mL/minute/1.73 m² /year; 95% CI, -3.99 to -1.07; P = 0.001), and the differences in the slopes were statistically significant (P = 0.026). In conclusion, in LT recipients with chronic HCV infection, achieving SVR significantly lowers the risk of decline in renal function and progression to ESRD independent of the AVT therapy used.

Hypoglycemia-Related Hospitalizations and Mortality Among Patients With Diabetes Transitioning to Dialysis

RATIONALE & OBJECTIVE

Diabetic patients with declining kidney function are at heightened risk for hypoglycemia. We sought to determine whether hypoglycemia-related hospitalizations in the interval before dialysis therapy initiation are associated with post-end-stage renal disease (ESRD) mortality among incident patients with ESRD with diabetes.

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

US veterans from the national Veterans Affairs database with diabetes and chronic kidney disease transitioning to dialysis therapy from October 2007 to September 2011.

EXPOSURE

Hypoglycemia-related hospitalizations during the pre-ESRD period and antidiabetic medication regimens.

OUTCOME

The outcome of post-ESRD all-cause mortality was evaluated relative to pre-ESRD hypoglycemia. The outcome of pre-ESRD hypoglycemia-related hospitalization was evaluated relative to antidiabetic medication regimens.

ANALYTIC APPROACH

We examined whether the occurrence and frequency of pre-ESRD hypoglycemia-related hospitalizations are associated with post-ESRD mortality using Cox regression models adjusted for case-mix covariates. In a subcohort of patients prescribed 0 to 2 oral antidiabetic drugs and/or insulin, we examined the 12 most commonly prescribed antidiabetic medication regimens and risk for pre-ESRD hypoglycemia-related hospitalization using logistic regression models adjusted for case-mix covariates.

RESULTS

Among 30,156 patients who met eligibility criteria, the occurrence of pre-ESRD hypoglycemia-related hospitalization(s) was associated with higher post-ESRD mortality risk: adjusted HR (aHR), 1.25; 95% CI, 1.17-1.34 (reference group: no hypoglycemia hospitalization). Increasing frequency of hypoglycemia-related hospitalizations was independently associated with incrementally higher mortality risk: aHRs of 1.21 (95% CI, 1.12-1.30), 1.47 (95% CI, 1.19-1.82), and 2.07 (95% CI, 1.46-2.95) for 1, 2, and 3 or more hypoglycemia-related hospitalizations, respectively (reference group: no hypoglycemia hospitalization). Compared with patients who were prescribed neither oral antidiabetic drugs nor insulin, medication regimens that included sulfonylureas and/or insulin were associated with higher risk for hypoglycemia.

LIMITATIONS

Residual confounding cannot be excluded.

CONCLUSIONS

Among incident patients with ESRD with diabetes, a dose-dependent relationship between frequency of pre-ESRD hypoglycemia-related hospitalizations and post-ESRD mortality was observed. Further study of diabetic management strategies that prevent hypoglycemia as patients with chronic kidney disease transition to ESRD are warranted.

Abrupt Decline in Kidney Function Precipitating Initiation of Chronic Renal Replacement Therapy

INTRODUCTION

Abrupt declines in kidney function often occur in patients with advanced chronic kidney disease and may exacerbate the need to initiate dialysis treatment. It is unclear how frequently such events occur in patients transitioning to chronic dialysis therapy, and what outcomes they are associated with.

METHODS

We examined a national cohort of 23,349 US veterans with incident end-stage renal disease (ESRD) and with available pre-ESRD estimated glomerular filtration rate (eGFR) to identify abrupt declines in kidney function, defined as an unexpected >50% decrease in eGFR at the time of chronic dialysis transition. Associations with all-cause mortality and with renal recovery were examined in Cox proportional hazard and competing risk regression models.

RESULTS

A total of 4804 (21%) patients experienced an abrupt decline in kidney function at dialysis transition. Renal recovery occurred in 586 (12.2%) and 297 (1.6%) patients with and without an abrupt decline, respectively (adjusted subhazard ratio: 4.42; 95% confidence interval [CI]: 3.72-5.27; P < 0.001). In the first 6 months after dialysis transition 1178 patients (24.5%) with abrupt decline died (annualized mortality rate 574/1000 patient-years), compared with 2354 deaths (12.7%) in patients without abrupt decline (274 deaths/1000 patient-years). An abrupt decline was associated with 45% higher mortality after multivariable adjustments (hazard ratio: 1.45; 95% CI: 1.33-1.57).

CONCLUSION

Abrupt declines in kidney function are common in patients transitioning to chronic dialysis, and are associated with higher mortality. Patients with abrupt declines also experience a higher rate of renal recovery; hence, careful attention to residual kidney function is warranted in these patients.

Successful Practice Transitioning Between Hemodialysis and Hemodiafiltration in Outpatient Units: Ten Key Issues for Physicians to Remember

Hemodiafiltration (HDF) during chronic renal replacement therapy (RRT) is a relatively new practice phenomenon, emerging over the last two decades. While the technological platforms utilized during chronic RRT are in many cases similar or effectively identical to conventional hemodialysis (HD), significant differences may emerge in daily practice. Several authors of this review moved practice site between the United States and the European Union and transitioned from an HD-based practice to predominantly HDF-practicing networks. In doing so, we became keenly aware of the potential pitfalls nephrologists may be facing during such transitions. This brief review is intended to provide a succinct overview of several practical concerns and complications nephrologists may encounter in daily practice of end-stage renal disease care, including but not limited to management of electrolytes, renal anemia and treatment goals and settings during HDF.