Comparison of causes of death using HEMO Study and HCFA end-stage renal disease death notification classification systems. The National Institutes of Health-funded Hemodialysis. Health Care Financing Administration

The Detrimental Impact of End-Stage Kidney Disease Is Not Reflected in Autopsy Reports

CONTEXT.—

End-stage kidney disease (ESKD) is defined as renal impairment requiring renal replacement therapy to sustain life. With a 1-year mortality of ∼20% to 30%, many die of complications related to this disease.

OBJECTIVE.—

To determine the percentage of autopsy cases of decedents with ESKD in which the contribution of ESKD to death is accurately reflected in the final report.

DESIGN.—

Autopsy case records were retrospectively reviewed at 4 institutions (Yale New Haven Hospital, University of Chicago Medical Center, University of Illinois at Chicago Hospital, University of Iowa Hospital). Clinical, macroscopic, and microscopic autopsy findings were reviewed, with attention to renal disease findings.

RESULTS.—

One hundred sixty decedents with documented ESKD and premortem dialysis who underwent autopsy assessment were identified. ESKD was implicated as a cause of death (CoD) or significant contributing factor in 44 cases (28%), but not in the remaining 116 cases (72%). Cardiovascular disease was the most common CoD in ESKD. There was significant interpathologist variation in the inclusion of ESKD as a CoD across institutions. These rates ranged from 85% correlation (23 of 27 cases), to 13% (4 of 31 and 8 of 62 cases at 2 institutions), and 22.5% (9 of 40 cases) across the 4 participating institutions.

CONCLUSIONS.—

The recognition at autopsy of ESKD as a CoD or contributing CoD at autopsy in patients undergoing dialysis remains low (28%). The detrimental impact of ESKD is not reflected in hospital autopsy reports, which carries implications for collection of vital statistics and allocation of research funding for kidney diseases.

Residual Kidney Function and Cause-Specific Mortality Among Incident Hemodialysis Patients

Introduction

The survival benefit of residual kidney function (RKF) in patients on hemodialysis is presumably due to enhanced fluid management and solute clearance. However, data are lacking on the association of renal urea clearance (CLurea) with specific causes of death.

Methods

We conducted a longitudinal cohort study of 39,623 adults initiating thrice-weekly in-center hemodialysis from 2007 to 2011 and had data on renal CLurea and urine volume. Multivariable cause-specific proportional hazards model was used to examine the associations between baseline RKF and cause-specific mortality, including sudden cardiac death (SCD), non-SCD cardiovascular death (CVD), and non-CVD. Restricted cubic splines were fitted for change in RKF over 6 months after initiating hemodialysis.

Results

Among 39,623 patients with data on baseline renal CLurea and urine volume, there was a significant trend toward a higher mortality risk across lower RKF levels, irrespective of cause of death in a case-mix adjustment model (Ptrend < 0.05). Adjustment for ultrafiltration rate (UFR) slightly attenuated the association between low renal CLurea and high cause-specific mortality, whereas adjustment for highest potassium did not have substantial effect. Among 12,169 patients with data on change in RKF, a 6-month decline in renal CLurea showed graded associations with SCD, non-SCD CVD, and non-CVD risk, whereas the graded associations between faster 6-month decline in urine output and higher death risk were clear only for SCD and non-CVD.

Conclusion

Lower RKF and loss of RKF were associated with higher cause-specific mortality among patients initiating thrice-weekly in-center hemodialysis.

Causes of Death in End-Stage Kidney Disease: Comparison between the United States Renal Data System and a Large Integrated Health Care System

INTRODUCTION

Using a large diverse population of incident end-stage kidney disease (ESKD) patients from an integrated health system, we sought to evaluate the concordance of causes of death (CODs) between the underlying COD from the United States Renal Data System (USRDS) registry and CODs obtained from Kaiser Permanente Southern California (KPSC).

METHODS

A retrospective cohort study was performed among incident ESKD patients who had mortality records and CODs reported in both KPSC and USRDS databases between January 1, 2007, and December 31, 2016. Underlying CODs reported by the KPSC were compared to the CODs reported by USRDS. Overall and subcategory-specific COD agreements were assessed using Cohen's weighted kappa statistic (95% CI). Proportions of positive and negative agreement were also determined.

RESULTS

Among 4,188 ESKD patient deaths, 4,118 patients had CODs recorded in both KPSC and USRDS. The most common KPSC CODs were circulatory system diseases (35.7%), endocrine/nutritional/metabolic diseases (24.2%), genitourinary diseases (12.9%), and neoplasms (9.6%). Most common USRDS CODs were cardiac disease (46.9%), withdrawal from dialysis (12.6%), and infection (10.1%). Of 2,593 records with causes listed NOT as "Other," 453 (17.4%) had no agreement in CODs between the USRDS and the underlying, secondary, tertiary, or quaternary causes recorded by KPSC. In comparing CODs recorded within KPSC to the USRDS, Cohen's weighted kappa (95% CI) was 0.20 (0.18-0.22) with overall agreement of 36.4%.

CONCLUSION

Among an incident ESKD population with mortality records, we found that there was only fair or slight agreement between CODs reported between the USRDS registry and KPSC, a large integrated health care system.

Cinacalcet and gastrointestinal bleeding risk in patients receiving hemodialysis

PURPOSE

Secondary hyperparathyroidism (SHPT) is common among dialysis patients, and calcimimetics are a mainstay of treatment. This study assessed whether cinacalcet use is associated with gastrointestinal bleeding in a large hemodialysis cohort.

METHODS

A linked database of clinical records and medical claims for patients receiving hemodialysis in a large dialysis organization, 2007-2010, was used. A nested case-control study was performed among patients aged ≥18 years who had received hemodialysis for ≥90 days, had Medicare Parts A, B, and D coverage for ≥1 year, and had clinical evidence of SHPT (parathyroid hormone >300 pg/mL). Cases were those who experienced death or hospitalization caused by gastrointestinal bleeding. Each case was matched to up to four controls. Exposure was measured by any cinacalcet use, current use, past use, cumulative exposure days, and cumulative dosage. Conditional logistic models were used to assess the association.

RESULTS

Of 48 437 patients included, 2570 experienced gastrointestinal bleeding events (2498 non-fatal, 72 fatal), and 2465 (2397 non-fatal, 68 fatal) were matched to 9500 controls; 17.2% of cases and 15.8% of controls had cinacalcet exposure and 11.1% of both cases and controls had current use. The adjusted odds ratios (95% CI) of gastrointestinal bleeding for any use, current use, and past use of cinacalcet were 1.04 (0.91-1.19), 0.97 (0.83-1.13), and 1.22 (0.99-1.50), respectively, with no use as the reference.

CONCLUSION

The results do not suggest an elevated risk of gastrointestinal bleeding resulting in hospitalization or death for hemodialysis patients exposed to cinacalcet.

Rheumatoid Arthritis and Mortality in End Stage Renal Disease

OBJECTIVE

To determine whether rheumatoid arthritis (RA) is a risk factor for cardiovascular disease (CVD) events, all-cause mortality and cardiovascular mortality in End Stage Renal Disease (ESRD).

METHODS

Cohort study of adult patients with ESRD in the United States Renal Data System (USRDS) with RA and a 5% random sample of those without RA. CVD events, all-cause mortality and cardiovascular mortality were determined in those with RA compared to those without RA using Cox Proportional Hazards modeling.

RESULTS

2,824 subjects, 407 with RA and 2,417 without RA, were included in the analyses. The duration of the study was up to 5 years, depending on mortality and initiation of dialysis. There were no significant differences in CVD events by RA status (n = 311 [76.4% RA] vs. n = 1936 [80.1% without RA], p = 0.09). Subjects with RA had a significantly shorter mean time in months from start of dialysis to an incident CVD event (20.1 ± 12.2 vs. 21.2 ± 14.1, p < 0.01) than those without RA. In multivariable adjusted models, RA was not associated with an increased risk for all-cause mortality (aHR = 1.09, 95%CI 0.94-1.27) or cardiovascular mortality (aHR = 0.95, 95% CI 0.74-1.22) within 5 years. Risk factors for all-cause mortality and cardiovascular mortality in RA included older age and a higher Charlson comorbidity index (CCI).

CONCLUSIONS

Clinicians should be aware that persons with RA who develop ESRD incur cardiac events sooner than the general population. However, RA is not an independent risk factor for all-cause or cardiovascular mortality in ESRD.

Survival outcomes for patients with surgically induced end-stage renal disease

INTRODUCTION

While medically induced end-stage renal disease (m-ESRD) has been well-studied, outcomes in patients with surgically induced ESRD (s-ESRD) are unknown. We sought to quantitatively compare the non-oncological outcomes for s-ESRD and m-ESRD in a large, population-based cohort.

METHODS

Medicare patients >65 years old initiating hemodialysis were identified using the U.S. Renal Data System database (2000-2012). Metastatic cancer, prior transplant history, and nephrectomy for polycystic kidney disease were exclusion criteria. Patients were classified as having s-ESRD or m-ESRD based on hospital and physician claims for nephrectomy within a year preceding the onset of maintenance hemodialysis. Outcomes included non-cancer mortality (NCM), overall survival (OS), cardiovascular event (CVE), and renal transplantation. Time-to-event analyses were performed using Kaplan-Meier and cumulative incidence curves, and multivariable Cox and Fine-and-Grey regression models.

RESULTS

The cohort included 312 612 patients, of whom 1648 (0.53%) had s-ESRD. Compared to m-ESRD patients, s-ESRD patients had a significantly lower five-year cumulative incidence of NCM (68% vs. 80%; p<0.001) and CVE (62% vs. 68%; p<0.001), with a correspondingly higher probability of OS (22% vs. 17%; p<0.001) and rate of renal transplantation (3.6% vs. 2.0%; p<0.001). On multivariable analyses, s-ESRD remained associated with lower risks of NCM (p<0.001) and CVE (p<0.001), improved OS (p<0.001), and higher chance of renal transplantation (p<0.001).

CONCLUSIONS

While outcomes for s-ESRD appear more favorable than m-ESRD, s-ESRD is still associated with a substantial risk of NCM and CVE, and a low incidence of renal transplantation in Medicare patients >65 years old. These non-oncological outcomes are worth considering in patients potentially facing postoperative ESRD.

Cardiovascular Outcomes of Calcium-Free vs Calcium-Based Phosphate Binders in Patients 65 Years or Older With End-stage Renal Disease Requiring Hemodialysis

IMPORTANCE

Guidelines restricting use of calcium-based phosphate binders in all patients with end-stage renal disease owing to their potential contribution to increased cardiovascular risk shifted prescribing from calcium acetate toward the costlier sevelamer carbonate products.

OBJECTIVE

To compare cardiovascular events and mortality between patients with end-stage renal disease (ESRD) undergoing hemodialysis receiving sevelamer vs calcium acetate in real-world practice.

DESIGN, SETTING, AND PARTICIPANTS

An observational cohort study was conducted using the United States Renal Data System linked to Medicare claims data (May 1, 2012, to December 31, 2013). Data analysis was performed from October 2017 to September 2018. Participants included patients 65 years or older with ESRD within 180 days after starting hemodialysis (sevelamer, 2647; calcium acetate, 2074).

EXPOSURES

New use of sevelamer (calcium-free phosphate binder) vs calcium acetate (calcium-based phosphate binder).

MAIN OUTCOMES AND MEASURES

Hazard ratios (HRs) with 95% CIs were estimated for fatal or nonfatal cardiovascular events (myocardial infarction or ischemic stroke: primary outcome) and all-cause mortality (secondary outcome) using Cox proportional hazards regression with fine stratification on the propensity score to control for potential confounders, including phosphorus and calcium levels.

RESULTS

After propensity score weighting, 2639 patients initiating sevelamer treatment (1184 men [44.9%]; mean [SD] age, 75.6 [6.9] years) and 2065 patients initiating calcium acetate treatment (930 men [45.0%]; mean [SD] age, 75.5 [7.1] years) were included in the analysis. Crude incidence rates (IRs) for cardiovascular events of 458 per 1000 person-years for sevelamer and 464 per 1000 person-years for calcium acetate were observed. After propensity score fine-stratification weighting, HRs of 0.96 (95% CI, 0.84-1.10) for cardiovascular events were observed. Results were consistent within subgroups of age (<75 y: primary outcome, HR, 1.02; 95% CI, 0.85-1.24; vs ≥75 years: primary outcome, HR, 0.83; 95% CI, 0.69-1.01) and sex (primary outcome in men: HR, 1.02; 95% CI, 0.83-1.26).

CONCLUSIONS AND RELEVANCE

The results of the study do not suggest increased cardiovascular safety of sevelamer in the routine clinical practice of patients with ESRD compared with calcium acetate; this study's findings suggest that well-designed, long-term, randomized clinical trials are needed.

Mortality and morbidity after pancreatoduodenectomy in patients undergoing hemodialysis: Analysis using a national inpatient database

BACKGROUND

Whether patients undergoing hemodialysis have greater risks of mortality and morbidity after pancreatoduodenectomy remains unknown.

METHODS

We used the Diagnosis Procedure Combination database, a national Japanese inpatient database, to identify patients who underwent pancreatoduodenectomy from July 2010 to March 2015. We conducted propensity-score-matching analyses to compare the outcomes, including postoperative complications and 30- and 90-day mortality after pancreatoduodenectomy between patients with and without hemodialysis.

RESULTS

Of 30,495 eligible patients, 307 (1.0%) received hemodialysis. In the unmatched cohort, the proportions of male sex, younger age, pancreatic cancer, ischemic heart disease, diabetes mellitus, and hypertension were greater in patients with hemodialysis than those without hemodialysis. A 1-to-4 propensity score matching created a total of 1,535 patients, including 307 with hemodialysis and 1,228 without hemodialysis. Patients undergoing hemodialysis had greater proportions of postoperative complications, including peritonitis (8.8% vs 4.8%, P = .012), sepsis or disseminated intravascular coagulation (3.6% vs 0.7%, P = .001), intra-abdominal bleeding (4.9% vs 0.7%, P < .001), and acute coronary event (4.2% vs 1.7%, P = .015). Propensity score matching showed that patients undergoing hemodialysis had an increased risk of postoperative complications (OR, 1.62; 95% CI, 1.23-2.14; P = .001), 30-day mortality (OR, 7.45; 95% CI, 3.26-17.0; P < .001), and 90-day mortality (OR, 10.9; 95% CI, 6.58-18.2; P < .001) than those not undergoing hemodialysis.

CONCLUSION

Patients undergoing hemodialysis had a significantly increased risk of postoperative complications and death after pancreatoduodenectomy. In particular, surgeons should consider the increased risk of intra-abdominal bleeding, peritonitis, sepsis or disseminated intravascular coagulation, and acute coronary event in patients with hemodialysis.

Declining comorbidity-adjusted mortality rates in English patients receiving maintenance renal replacement therapy

We aimed to compare long-term mortality trends in end-stage renal disease versus general population controls after accounting for differences in age, sex and comorbidity. Cohorts of 45,000 patients starting maintenance renal replacement therapy (RRT) and 5.3 million hospital controls were identified from two large electronic hospital inpatient data sets: the Oxford Record Linkage Study (1965-1999) and all-England Hospital Episode Statistics (2000-2011). All-cause and cause-specific three-year mortality rates for both populations were calculated using Poisson regression and standardized to the age, sex, and comorbidity structure of an average 1970-2008 RRT population. The median age at initiation of RRT in 1970-1990 was 49 years, increasing to 61 years by 2006-2008. Over that period, there were increases in the prevalence of vascular disease (from 10.0 to 25.2%) and diabetes (from 6.7 to 33.9%). After accounting for age, sex and comorbidity differences, standardized three-year all-cause mortality rates in treated patients with end-stage renal disease between 1970 and 2011 fell by about one-half (relative decline 51%, 95% confidence interval 41-60%) steeper than the one-third decline (34%, 31-36%) observed in the general population. Declines in three-year mortality rates were evident among those who received a kidney transplant and those who remained on dialysis, and among those with and without diabetes. These data suggest that the full extent of mortality rate declines among RRT patients since 1970 is only apparent when changes in comorbidity over time are taken into account, and that mortality rates in RRT patients appear to have declined faster than in the general population.

Disparities in early mortality among chronic kidney disease patients who transition to peritoneal dialysis and hemodialysis with and without catheters

PURPOSE

The early period after chronic kidney disease (CKD) patients transition to end-stage renal disease (ESRD) represents the highest mortality risk but is variable among different patient populations and clinical circumstances. We compared early mortality outcomes among a diverse CKD population that transitioned to ESRD.

METHODS

A retrospective cohort study (1/1/2002 through 12/31/2013) of CKD patients (age ≥ 18 years) who transitioned to peritoneal dialysis (PD), hemodialysis (HD) with arteriovenous fistula/grafts, and HD with catheters was performed. Multivariable Cox regression modeling was used to estimate 6-month all-cause mortality hazard ratios (HR) among the three treatment groups after adjustment for patient and clinical characteristics.

RESULTS

Among 5373 ESRD patients (62.7 years, 41.3% females, 37.5% Hispanics, 13.3% PD, 34.9% HD with fistula/graft, 51.8% HD with catheter), 551 (10.3%) died at 6 months. Mortality rates were highest immediately after transition (299 deaths per 1000 person-years in first month). Compared to PD patients, the 6-month mortality HR (95% CI) was 1.87 (1.06-3.30) in HD with fistula/graft patients and 3.77 (2.17-6.57) in HD with catheter patients. Inpatient transition (HR 1.32), acute kidney injury (HR 2.06), and an eGFR ≥ 15 vs 5-9 (HR 1.68) at transition were also associated with higher early mortality risk.

CONCLUSION

Among a diverse CKD population who transitioned to ESRD, we observed considerable differences in early mortality risk among PD, HD with fistula/graft, and HD with catheter patients. The identification of patient-specific and clinical environmental factors related to high early mortality may provide insights for managing advanced stages of CKD and shared decision making.

Results of the HEMO Study suggest that p-cresol sulfate and indoxyl sulfate are not associated with cardiovascular outcomes

Cardiovascular disease, the leading cause of mortality in hemodialysis patients, is not fully explained by traditional risk factors. To help define non-traditional risk factors, we determined the association of predialysis total p-cresol sulfate, indoxyl sulfate, phenylacetylglutamine, and hippurate with cardiac death, sudden cardiac death, and first cardiovascular event in the 1,273 participants of the HEMO Study. The results were adjusted for potential demographic, clinical, and laboratory confounders. The mean age of the patients was 58 years, 63% were Black and 42% were male. Overall, there was no association between the solutes and outcomes. However, in sub-group analyses, among patients with lower serum albumin (under 3.6 g/dl), a twofold higher p-cresol sulfate was significantly associated with a 12% higher risk of cardiac death (hazard ratio 1.12; 95% confidence interval, 0.98-1.27) and 22% higher risk of sudden cardiac death (1.22, 1.06-1.41). Similar trends were also noted with indoxyl sulfate. Trial interventions did not modify the association between these solutes and outcomes. Routine clinical and lab data explained less than 22% of the variability in solute levels. Thus, in prevalent hemodialysis patients participating in a large U.S. hemodialysis trial, uremic solutes p-cresol sulfate, indoxyl sulfate, hippurate, and phenylacetylglutamine were not associated with cardiovascular outcomes. However, there were trends of toxicity among patients with lower serum albumin.

Sudden Cardiac Death Among Hemodialysis Patients

Hemodialysis patients carry a large burden of cardiovascular disease; most onerous is the high risk for sudden cardiac death. Defining sudden cardiac death among hemodialysis patients and understanding its pathogenesis are challenging, but inferences from the existing literature reveal differences between sudden cardiac death among hemodialysis patients and the general population. Vascular calcifications and left ventricular hypertrophy may play a role in the pathophysiology of sudden cardiac death, whereas traditional cardiovascular risk factors seem to have a more muted effect. Arrhythmic triggers also differ in this group as compared to the general population, with some arising uniquely from the hemodialysis procedure. Combined, these factors may alter the types of terminal arrhythmias that lead to sudden cardiac death among hemodialysis patients, having important implications for prevention strategies. This review highlights current knowledge on the epidemiology, pathophysiology, and risk factors for sudden cardiac death among hemodialysis patients. We then examine strategies for prevention, including the use of specific cardiac medications and device-based therapies such as implantable defibrillators. We also discuss dialysis-specific prevention strategies, including minimizing exposure to low potassium and calcium dialysate concentrations, extending dialysis treatment times or adding sessions to avoid rapid ultrafiltration, and lowering dialysate temperature.

Serum Asymmetric and Symmetric Dimethylarginine and Morbidity and Mortality in Hemodialysis Patients

BACKGROUND

Asymmetric (ADMA) and symmetric dimethylarginine (SDMA) are putative uremic toxins that may exert toxicity by a number of mechanisms, including impaired nitric oxide synthesis and generation of reactive oxygen species. The study goal was to determine the association between these metabolites and cardiovascular outcomes in hemodialysis patients.

STUDY DESIGN

Post hoc analysis of the Hemodialysis (HEMO) Study.

SETTING & PARTICIPANTS

1,276 prevalent hemodialysis patients with available samples 3 to 6 months after randomization.

PREDICTOR

ADMA and SDMA measured in stored specimens.

OUTCOMES

Cardiac death, sudden cardiac death, first cardiovascular event, and any-cause death. Association with predictors analyzed using Cox regression adjusted for potential confounders (including demographics, clinical characteristics, comorbid conditions, albumin level, and residual kidney function).

RESULTS

Mean age of patients was 57±14 (SD) years, 63% were black, and 57% were women. Mean ADMA (0.9±0.2μmol/L) and SDMA levels (4.3±1.4μmol/L) were moderately correlated (r=0.418). Higher dialysis dose or longer session length were not associated with lower predialysis ADMA or SDMA concentrations. In fully adjusted models, each doubling of ADMA level was associated with higher risk (HR per 2-fold higher concentration; 95% CI) of cardiac death (1.83; 1.29-2.58), sudden cardiac death (1.79; 1.19-2.69), first cardiovascular event (1.50; 1.20-1.87), and any-cause death (1.44; 1.13-1.83). Compared to the lowest ADMA quintile (<0.745 μmol/L), the highest ADMA quintile (≥1.07μmol/L) was associated with higher risk (HR; 95% CI) of cardiac death (2.10; 1.44-3.05), sudden cardiac death (2.06; 1.46-2.90), first cardiovascular event (1.75; 1.35-2.27), and any-cause death (1.56; 1.21-2.00). SDMA level was associated with higher risk for cardiac death (HR, 1.40; 95% CI, 1.03-1.92), but this was no longer statistically significant after adjusting for ADMA level (HR, 1.20; 95% CI, 0.86-1.68).

LIMITATIONS

Single time-point measurement of ADMA and SDMA.

CONCLUSIONS

ADMA and, to a lesser extent, SDMA levels are associated with cardiovascular outcomes in hemodialysis patients.

Trimethylamine N-Oxide and Cardiovascular Events in Hemodialysis Patients

Cardiovascular disease causes over 50% of the deaths in dialysis patients, and the risk of death is higher in white than in black patients. The underlying mechanisms for these findings are unknown. We determined the association of the proatherogenic metabolite trimethylamine N-oxide (TMAO) with cardiovascular outcomes in hemodialysis patients and assessed whether this association differs by race. We measured TMAO in stored serum samples obtained 3-6 months after randomization from a total of 1232 white and black patients of the Hemodialysis Study, and analyzed the association of TMAO with cardiovascular outcomes using Cox models adjusted for potential confounders (demographics, clinical characteristics, comorbidities, albumin, and residual kidney function). Mean age of the patients was 58 years; 35% of patients were white. TMAO concentration did not differ between whites and blacks. In whites, 2-fold higher TMAO associated with higher risk (hazard ratio [95% confidence interval]) of cardiac death (1.45 [1.24 to 1.69]), sudden cardiac death [1.70 (1.34 to 2.15)], first cardiovascular event (1.15 [1.01 to 1.32]), and any-cause death (1.22 [1.09 to 1.36]). In blacks, the association was nonlinear and significant only for cardiac death among patients with TMAO concentrations below the median (1.58 [1.03 to 2.44]). Compared with blacks in the same quintile, whites in the highest quintile for TMAO (≥135 μM) had a 4-fold higher risk of cardiac or sudden cardiac death and a 2-fold higher risk of any-cause death. We conclude that TMAO concentration associates with cardiovascular events in hemodialysis patients but the effects differ by race.

Antidepressants for treating depression in adults with end-stage kidney disease treated with dialysis

BACKGROUND

Depression affects approximately one-quarter of people treated with dialysis and is considered an important research uncertainty by patients and health professionals. Treatment for depression in dialysis patients may have different benefits and harms compared to the general population due to different clearances of antidepressant medication and the severity of somatic symptoms associated with end-stage kidney disease (ESKD). Guidelines suggest treatment of depression in dialysis patients with pharmacological therapy, preferably a selective serotonin reuptake inhibitor. This is an update of a review first published in 2005.

OBJECTIVES

To evaluate the benefit and harms of antidepressants for treating depression in adults with ESKD treated with dialysis.

SEARCH METHODS

We searched Cochrane Kidney and Transplant's Specialised Register to 20 January 2016 through contact with the Information Specialist using search terms relevant to this review.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing antidepressant treatment with placebo or no treatment, or compared to another antidepressant medication or psychological intervention in adults with ESKD (estimated glomerular filtration rate < 15 mL/min/1.73 m(2)).

DATA COLLECTION AND ANALYSIS

Data were abstracted by two authors independently onto a standard form and subsequently entered into Review Manager. Risk ratios (RR) for dichotomous data and mean differences (MD) for continuous data were calculated with 95% confidence intervals (95% CI).

MAIN RESULTS

Four studies in 170 participants compared antidepressant therapy (fluoxetine, sertraline, citalopram or escitalopram) versus placebo or psychological training for 8 to 12 weeks. In generally very low or ungradeable evidence, compared to placebo, antidepressant therapy had no evidence of benefit on quality of life, had uncertain effects on increasing the risk of hypotension (3 studies, 144 participants: RR 1.72, 95% CI 0.75 to 3.92), headache (2 studies 56 participants: RR 2.91, 95% CI 0.73 to 11.57), and sexual dysfunction (2 studies, 101 participants: RR 3.83, 95% CI 0.63 to 23.34), and increased nausea (3 studies, 114 participants: RR 2.67, 95% CI 1.26 to 5.68). There were few or no data for hospitalisation, suicide or all-cause mortality resulting in inconclusive evidence. Antidepressant therapy may reduce depression scores during treatment compared to placebo (1 study, 43 participants: MD -7.50, 95% CI -11.94 to -3.06). Antidepressant therapy was not statistically different from group psychological therapy for effects on depression scores or withdrawal from treatment and a range of other outcomes were not measured.

AUTHORS' CONCLUSIONS

Despite the high prevalence of depression in dialysis patients and the relative priority that patients place on effective treatments, evidence for antidepressant medication in the dialysis setting is sparse and data are generally inconclusive. The relative benefits and harms of antidepressant therapy in dialysis patients are poorly known and large randomised studies of antidepressants versus placebo are required.

Immune Sensitization and Mortality in Wait-Listed Kidney Transplant Candidates

Cardiovascular mortality is the leading cause of death in ESRD. Whereas innate and adaptive immunity have established roles in cardiovascular disease, the role of humoral immunity is unknown. We conducted a retrospective cohort study in first-time adult kidney transplant candidates (N=161,308) using data from the Scientific Registry of Transplant Recipients and the Centers for Medicare and Medicaid Services to evaluate whether anti-human leukocyte antigen antibodies, measured as panel reactive antibodies (PRAs), are related to mortality in ESRD. Relationships between time-varying PRAs and all-cause or cardiovascular mortality were assessed using Cox proportional hazards models. The analysis was repeated in subcohorts of candidates at lower risk for significant comorbidities, activated on the waiting list after 2007, or unsensitized at activation. Competing risks analyses were also conducted. Fully adjusted models showed increased hazard ratios (HRs [95% confidence intervals]) for all-cause mortality (HR, 1.02 [95% CI, 0.99 to 1.06]; HR, 1.11 [95% CI,1.07 to 1.16]; and HR,1.21 [95% CI,1.15 to 1.27]) and cardiovascular mortality (HR, 1.05 [95% CI,1.00 to 1.10]; HR,1.11 [95% CI,1.05 to 1.18]; and HR,1.21 [95% CI,1.12 to 1.31]) in PRA 1%-19%, PRA 20%-79%, and PRA 80%-100% categories compared with PRA 0%, respectively. Associations between PRA and the study outcomes were accentuated in competing risks models and in lower-risk patients and persisted in other subcohorts. Our findings suggest that PRA is an independent predictor of mortality in wait-listed kidney transplant candidates. The mechanisms by which PRA confers an incremental mortality risk in sensitized patients, and the role of transplantation in modifying this risk, warrant further study.

Heritability of Risk for Sudden Cardiac Arrest in ESRD

Patients on dialysis are 20 times more likely to have a cardiac arrest compared with the general population. We considered whether inherited factors associate with cardiac arrest among patients on dialysis. From a sample of 647,457 patients on chronic dialysis, we identified 5117 pairs of patients who came from the same family. These patients were each matched to a control subject from the same population. McNemar's tests were used to compare the risk of cardiac arrest between the familial related and unrelated pairs. Genetically related family members who did not cohabitate had an odds ratio of 1.88 (95% confidence interval [95% CI], 1.25 to 2.84) for cardiac arrest compared with their phenotypically matched unrelated controls. Genetically related family members who lived together in the same environment had an odds ratio of 1.66 (95% CI, 1.20 to 2.28). Spouses, who are genetically unrelated but live together in the same environment, had an odds ratio of 0.95 (95% CI, 0.60 to 1.59) for cardiac arrest. The risk of cardiac arrest in patients on dialysis may be attributable to inherited factors. Additional studies are needed to identify such candidate genes that modify cardiovascular risk in ESRD.

Long-term Effects of Frequent Nocturnal Hemodialysis on Mortality: The Frequent Hemodialysis Network (FHN) Nocturnal Trial

BACKGROUND

Few data are available regarding the long-term mortality rate for patients receiving nocturnal home hemodialysis.

STUDY DESIGN

Posttrial observational study.

SETTING & PARTICIPANTS

Frequent Hemodialysis Network (FHN) Nocturnal Trial participants who consented to extended follow-up.

INTERVENTION

The FHN Nocturnal Trial randomly assigned 87 individuals to 6-times-weekly home nocturnal hemodialysis or 3-times-weekly hemodialysis for 1 year. Patients were enrolled starting in March 2006 and follow-up was completed by May 2010. After the 1-year trial concluded, FHN Nocturnal participants were free to modify their hemodialysis prescription.

OUTCOMES & MEASUREMENTS

We obtained dates of death and kidney transplantation through July 2011 using linkage to the US Renal Data System and queries of study centers. We used log-rank tests and Cox regression to relate mortality to the initial randomization assignment.

RESULTS

Median follow-up for the trial and posttrial observational period was 3.7 years. In the nocturnal arm, there were 2 deaths during the 12-month trial period and an additional 12 deaths during the extended follow-up. In the conventional arm, the numbers of deaths were 1 and 4, respectively. In the nocturnal dialysis group, the overall mortality HR was 3.88 (95% CI, 1.27-11.79; P=0.01). Using as-treated analysis with a 12-month running treatment average, the HR for mortality was 3.06 (95% CI, 1.11-8.43; P=0.03). Six-month running treatment data analysis showed an HR of 1.12 (95% CI, 0.44-3.22; P=0.7).

LIMITATIONS

These results should be interpreted cautiously due to a surprisingly low (0.03 deaths/patient-year) mortality rate for individuals randomly assigned to conventional home hemodialysis, low statistical power for the mortality comparison due to the small sample size, and the high rate of hemodialysis prescription changes.

CONCLUSIONS

Patients randomly assigned to nocturnal hemodialysis had a higher mortality rate than those randomly assigned to conventional dialysis. The implications of this result require further investigation.

Protein carbamylation is associated with heart failure and mortality in diabetic patients with end-stage renal disease

Serum carbamylated albumin (C-Alb) levels are associated with excess mortality in patients with diabetic end stage renal disease. To gain insight into the pathophysiology of carbamylation, we determined associations between C-Alb and causes of death in patients on chronic hemodialysis. The Die Deutsche Diabetes Dialyse Studie (4D study) was a randomized controlled trial testing the effects of atorvastatin on survival in diabetic patients on dialysis during a median follow-up of 4 years. We stratified 1,161 patients by C-Alb to see if differences in carbamylation altered the effects of atorvastatin on survival. Baseline C-Alb significantly correlated with serum cardiac stress markers troponin T and N-terminal pro-B-type-natriuretic peptide, and was associated with history of heart failure and arrhythmia. C-Alb was strongly associated with 1-year adjusted risk of CV mortality, sudden cardiac death and the 4-year risk of death from congestive heart failure (Hazard Ratios of 3.06, 3.78 and 4.64, respectively), but not with myocardial infarction or stroke. Patients with low C-Alb, treated with atorvastatin, experienced a significant improvement in their 4-year survival (Hazard Ratio 0.692). High C-Alb levels are associated with ongoing cardiac damage, risk of congestive heart failure and sudden cardiac death. Thus, carbamylation and uremic cardiomyopathy are associated in patients with diabetes mellitus and kidney disease. Additionally, statins were specifically beneficial to hemodialysis patients with low C-Alb.

Markers of increased cardiovascular risk in patients with chronic kidney disease

BACKGROUND

Epidemiological studies have shown that chronic kidney disease (CKD) is an important risk factor for atherosclerosis and cardiovascular disease (CAD). The aim of the study was to determine markers of increased risk of CAD and to achieve a better understanding of agents implicated in the process of atherosclerosis in CKD patients.

METHODS

The study group consisted of a total of 139 patients with CKD while the control group comprised 45 healthy volunteers. Concentrations of osteoprotegerin, osteopontin, osteocalcin, matrix γ-carboxyglutamic acid (Gla) protein (MGP), fetuin A, matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), tissue inhibitor of metalloproteinase-2 (TIMP-2), ATP binding cassette transporter A1 (ABCA1), ATP binding cassette transporter G1 (ABCG1) and renalase were measured by the ELISA method.

RESULTS

We observed decreased levels of fetuin A (control vs. CKD group: 37.5 vs. 33.2 ng/ml, p = 0.018), and increased concentrations of osteocalcin (control vs. CKD group: 9.1 ± 6.0 vs. 13.6 ± 10.3 ng/ml, p = 0.05), MMP-2 (113.1 ± 75.0 vs. 166.0 ± 129.9 ng/ml, p = 0.045), TIMP-2 (22.1 ± 5.1 vs. 25.4 ± 7,0 ng/ml, p = 0.005) and renalase (251.0 ± 157 vs. 316.1 ± 155.3 ng/ml, p = 0.026). In patients with CKD (in comparison to control group), left ventricle ejection fraction: 53.0 ± 3,5% vs. 48.5%, p = 0.012) and calcification of the aortic valve (9.5% vs. 39.8%, p = 0.008) were observed more frequently.

CONCLUSIONS

Decreased levels of fetuin A and increased concentration of osteocalcin, renalase, MMP-2 and TIMP-2 suggest that these factors may be involved in the pathogenesis of CAD in patients with CKD. Significantly increased indices of cardiac hypertrophy and its dysfunction in patients with CKD are indicators of pathological mechanisms occurring in cardiovascular system in this group of patients.

High blood pressure in dialysis patients: cause, pathophysiology, influence on morbidity, mortality and management

Dialysis is initiated in a patient with End stage renal disease. The recent guidelines suggest the initiation of dialysis when symptoms and signs of kidney failure are present and not merely a decrease in GFR. The most common complication postdialysis is the occurrence of hypotension. However many dialysis patients are found to be hypertensive. In this article, we mention the cause and pathophysiology of hypertension in dialysis patients and its management.

Near-term prediction of sudden cardiac death in older hemodialysis patients using electronic health records

BACKGROUND AND OBJECTIVES

Sudden cardiac death is the most common cause of death among individuals undergoing hemodialysis. The epidemiology of sudden cardiac death has been well studied, and efforts are shifting to risk assessment. This study aimed to test whether assessment of acute changes during hemodialysis that are captured in electronic health records improved risk assessment.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data were collected from all hemodialysis sessions of patients 66 years and older receiving hemodialysis from a large national dialysis provider between 2004 and 2008. The primary outcome of interest was sudden cardiac death the day of or day after a dialysis session. This study used data from 2004 to 2006 as the training set and data from 2007 to 2008 as the validation set. The machine learning algorithm, Random Forests, was used to derive the prediction model.

RESULTS

In 22 million sessions, 898 people between 2004 and 2006 and 826 people between 2007 and 2008 died on the day of or day after a dialysis session that was serving as a training or test data session, respectively. A reasonably strong predictor was derived using just predialysis information (concordance statistic=0.782), which showed modest but significant improvement after inclusion of postdialysis information (concordance statistic=0.799, P<0.001). However, risk prediction decreased the farther out that it was forecasted (up to 1 year), and postdialytic information became less important.

CONCLUSION

Subtle changes in the experience of hemodialysis aid in the assessment of sudden cardiac death and are captured by modern electronic health records. The collected data are better for the assessment of near-term risk as opposed to longer-term risk.

Serum testosterone levels and clinical outcomes in male hemodialysis patients

BACKGROUND

Studies linking low serum testosterone concentration to adverse clinical outcomes in hemodialysis patients have been relatively small. We investigated the role of testosterone in adverse outcomes and quality of life in an incident cohort of male Canadian hemodialysis patients.

STUDY DESIGN

A prospectively designed multicenter observational study using data from the Canadian Kidney Disease Cohort Study (CKDCS).

SETTING & PARTICIPANTS

Male patients initiating hemodialysis therapy since February 14, 2005, in 3 Canadian centers serving ethnically diverse populations were studied (N = 623).

PREDICTOR

Serum testosterone levels using the International Society of Andrology, International Society for the Study of the Aging Male, and European Association of Urology cutoffs (low, <231 ng/dL; borderline, 231-346 ng/dL; normal, >346 ng/dL).

OUTCOMES

All-cause mortality, fatal and nonfatal cardiovascular (CV) events, and Health Utility Index (HUI)-assessed health-related quality of life.

MEASUREMENTS

Participants completed a structured interview on demographics and medical history and an HUI questionnaire (version 3). Routine laboratory test results captured into the study database, and serum testosterone measured within 3 months after initiation of the baseline hemodialysis session.

RESULTS

During a median follow-up of 20 (range, 1-81) months, 166 (27%) died and 98 (20%) had a CV event. Mean serum testosterone level was 234.1 ± 146.1 (SD) ng/dL. Higher serum testosterone levels were associated with significantly decreased unadjusted risk of death (HR per 10-ng/dL increase, 0.58; 95% CI, 0.37-0.90). There was a statistically significant trend for higher all-cause mortality with low serum testosterone levels in adjusted analyses (P < 0.001). Higher levels of log-transformed testosterone were associated with significantly higher HUI scores (P for trend <0.001), and low levels of serum testosterone were associated significantly with lower HUI scores (P for trend <0.001). Although there was a significant trend in the unadjusted risk of CV events among participants with low serum testosterone levels (P < 0.001), the risk was no longer significant after adjustment for age. There was no significant interaction with age and serum testosterone level tested as continuous variables (P = 0.07).

LIMITATIONS

A short follow-up period and serum testosterone measured on a single occasion.

CONCLUSIONS

Low serum testosterone concentration may be a modifiable risk factor for adverse outcomes and poor quality of life in male hemodialysis patients. This hypothesis should be tested in randomized controlled trials.

CT coronary angiography is feasible for the assessment of coronary artery disease in chronic dialysis patients, despite high average calcium scores

Purpose

Significant obstructive coronary artery disease (CAD) is common in asymptomatic dialysis patients. Identifying these high risk patients is warranted and may improve the prognosis of this vulnerable patient group. Routine catheterization of incident dialysis patients has been proposed, but is considered too invasive. CT-angiography may therefore be more appropriate. However, extensive coronary calcification, often present in this patient group, might hamper adequate lumen evaluation. The objective of this study was to assess the feasibility of CT-angiography in this patient group.

Methods

For this analysis all patients currently participating in the ICD2 trial (ISRCTN20479861), with no history of PCI or CABG were included. The major epicardial vessels were evaluated on a segment basis (segment 1–3, 5–8, 11 and 13) by a team consisting of an interventional and an imaging specialist. Segments were scored as not significant, significant and not interpretable.

Results

A total of 70 dialysis patients, with a mean age of 66±8 yrs and predominantly male (70%) were included. The median calcium score was 623 [79, 1619].

Over 90% of the analyzed segments were considered interpretable. The incidence of significant CAD on CT was 43% and was associated with cardiovascular events during follow-up. The incidence of cardiovascular events after 2-years follow-up: 36% vs. 0% in patients with no significant CAD (p<0.01).

Conclusion

Despite the high calcium scores CT-angiography is feasible for the evaluation of the extent of CAD in dialysis patients. Moreover the presence of significant CAD on CT was associated with events during follow-up.

Retained organic solutes, patient characteristics and all-cause and cardiovascular mortality in hemodialysis: results from the retained organic solutes and clinical outcomes (ROSCO) investigators

BACKGROUND

Multiple solutes are retained in uremia, but it is currently unclear which solutes are toxic. Small studies suggest that protein-bound solutes, such as p-cresol sulfate and indoxyl sulfate and intracellular solutes, such as methylamine (MMA) and dimethylamine (DMA), may be toxic. Our objective was to test whether elevated levels of these solutes were associated with mortality.

METHODS

We conducted a prospective cohort study in 521 U.S. incident hemodialysis patients to evaluate associations between these solutes and all-cause and cardiovascular mortality. P-cresol sulfate, indoxyl sulfate, MMA and DMA levels were measured from frozen plasma samples obtained 2 to 6 months after initiation of dialysis. Mortality data was available through 2004 using the National Death Index.

RESULTS

Elevated (greater than the population median) p-cresol sulfate, MMA or DMA levels were not associated with all-cause or cardiovascular mortality. Elevated indoxyl sulfate levels were associated with all-cause mortality but not cardiovascular mortality (hazard ratio 1.30 (95% confidence interval 1.01, 1.69) p-value 0.043).

CONCLUSIONS

In this cohort of 521 incident hemodialysis patients, only elevated indoxyl sulfate levels were associated with all-cause mortality. Further research is needed to identify causes of the toxicity of uremia to provide better care for patients with kidney disease.

The USRDS: what you need to know about what it can and can't tell us about ESRD

This article summarizes the administrative structure underlying the Unites States Renal Data System (USRDS); summarizes incidence, prevalence, patient characteristics, and treatment modalities; and describes data regarding clinical indicators and preventive care, hospitalization, survival, and costs. The USRDS recently instituted a comprehensive assessment system to characterize the transition to the new Centers for Medicare & Medicaid Services Prospective Payment System, which bundles into a single payment several integral components of dialysis care. This challenging initiative will be an important component of future USRDS Annual Data Reports. The main strengths of the USRDS are its size and representativeness, nearly complete inclusion of the US end-stage renal disease population, and linkage to Medicare claims. Limitations include lack of continuous validation of its methods, lack of complete comorbidity and laboratory data at registration, an initial survival bias, and lack of accuracy of cause-of-death reporting.

Mortality of dialysis patients according to influenza and pneumococcal vaccination status

BACKGROUND

Data from an immunocompromised subpopulation in which both vaccine recipients and nonrecipients have frequent opportunities for vaccination can help determine the associations between vaccination against seasonal influenza and pneumococcal disease and all-cause mortality.

STUDY DESIGN

We surveyed dialysis centers and performed a retrospective analysis of health status at dialysis therapy initiation, vaccination for influenza and pneumococcal disease, laboratory results, and mortality associated with the 2005-2006 influenza season for patients in 3 End-Stage Renal Disease Networks across the United States.

SETTING & PARTICIPANTS

Of 1,033 dialysis facilities considered, 903 centers with a total patient population of 54,734 reported vaccination data. Analysis was limited to 36,966 patients on dialysis treatment for at least 1 year as of December 31, 2005.

PREDICTOR

Vaccination status.

OUTCOMES

OR for all-cause mortality (vaccinated vs unvaccinated patients).

RESULTS

The estimated adjusted OR for mortality was significantly less than 1.0 for patient who received either vaccination and was lower for patients who had received both vaccinations than for those who had received either. Survival analysis confirmed these findings.

LIMITATIONS

Possible misclassification due to self-report of vaccination for some patients. Lack of vaccination date.

CONCLUSIONS

Vaccination against influenza and pneumococcal disease is associated with improved survival in dialysis patients. The 2 vaccinations have independent effects on mortality.

Statistical analysis and design for estimating accuracy in clinical-center classification of cause-specific clinical events in clinical trials

BACKGROUND

When cause-specific clinical events (for instance, hospitalization for cardiac disease) are used as the primary or key secondary outcomes, it is important to assess how accurately these events have been classified and estimate the error-corrected treatment effects to ensure validity. However, it may not be feasible to verify cause classification for every event in large clinical trials.

PURPOSE

We present statistical methods for the design and analysis of outcome-classification accuracy and for estimating error-corrected treatment effects.

METHODS

Using the Hemodialysis (HEMO) Study, in which primary causes were designated for all 7822 hospitalizations by the 15 participating clinical centers - but only two subsets were audited by the Outcome Committee - we applied existing methods to obtain unbiased estimates of the sensitivity and specificity of clinical-center classifications. The multiple imputation method was used to correct for the misclassification of events. We then examined how trial results were affected by three methods of event classification: unaudited, imputed, and adjudicated.

RESULTS

We applied a three-step procedure to extend the results for the two subsets of audited events to estimate the sensitivity and specificity for the complete set. Finite population sample size formulas were developed for designing the quality control sample. Based on the HEMO analysis, the estimate of the intervention effect using the unaudited outcome was biased; the bias was reduced using the outcome corrected by imputation.

LIMITATIONS

The methods are limited to situations in which there are clinical-center classifications for all clinical events but only partial availability of reference standard classifications, and the verification process does not depend on the true event cause or other unobserved information.

CONCLUSIONS

Designing a quality control study to estimate the accuracy of outcome classification is important. The multiple imputation method can be used to correct for errors in outcome classification and to estimate the error-corrected treatment effect. Trial results need to be reexamined using the error-corrected outcome.

Change in cardiovascular disease status in peritoneal dialysis patients: a 5-year single-center experience

BACKGROUND

We compared patient characteristics, atherosclerosis, left ventricular hypertrophy, and dialysis practice patterns of peritoneal dialysis (PD) patients with change in cardiovascular disease (CVD) status and no change in CVD status in Chinese PD center.

METHODS

This study included all patients who started on PD between 1 January 2003 and 30 June 2009 at the Renji Hospital, Shanghai Jiaotong University School of Medicine, China. They were followed up from the date of PD initiation until new-onset CVD.

RESULTS

The median follow-up time was 44.13 months. In patients with preexisting CVD, both high triglyceride (1.43 ± 0.89 mmol/L vs. 2.64 ± 1.58 mmol/L, p < 0.001) and the duration of dialysis (45.76 ± 13.28 months vs. 58.68 ± 13.74 months, p < 0.01) were independent predictors of CVD progression and the left atrial dimension, left ventricle septal thickness, left ventricle mass index (LVMI), and intima-media thickness (IMT) also had the difference. On the other hand, in patients without preexisting CVD, the dialysis adequacy and nutritional status are important during the follow-up. Serum albumin in CVD group was lower than in no CVD group (30.86 ± 4.77 g/L vs. 36.04 ± 6.40 g/L, p < 0.05). Creatinine clearance (CCr) and Kt/V in CVD group were lower than in no CVD group (CCr 57.24 ± 13.86 L/week vs. 71.06 ± 23.96 L/week, p < 0.05; Kt/V 1.82 ± 0.41 vs. 2.23 ± 0.57, p < 0.05).

CONCLUSION

In patients with preexisting CVD, it is important to address traditional risk factors such as LVMI, IMT, and lipid profile. In patients without preexisting CVD, we should pay more attention to the nutritional status and PD prescription in order to lower the morbidity of CVD in these PD patients.

Predictors of sudden cardiac death: a competing risk approach in the hemodialysis study

BACKGROUND AND OBJECTIVES

There are few data on risk factors for sudden cardiac death (SCD) in patients undergoing hemodialysis (HD). The study objective was to identify predictors associated with various causes of death in the Hemodialysis (HEMO) Study and to develop a prediction model for SCD using a competing risk approach.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In this analysis of 1745 HEMO participants, all-cause mortality was classified as SCD, non-SCD, and noncardiac death. Predictors for each cause of death were evaluated using cause-specific Cox proportional hazards models, and a competing risk approach was used to calculate absolute risk predictions for SCD.

RESULTS

During a median follow-up of 2.5 years, 808 patients died. Rates of SCD, non-SCD, and noncardiac death were 22%, 17%, and 61%, respectively. Predictors of various causes of death differ somewhat in HD patients. Age, diabetes, peripheral vascular disease, ischemic heart disease, serum creatinine, and alkaline phosphatase were independent predictors of SCD. The 3-year C-statistic for SCD was 0.75 (95% confidence interval, 0.70-0.79), and calibration was good (χ(2)=1.1; P=0.89). At years 3 and 5 of follow-up, the standard Cox model overestimated the risk for SCD as compared with the competing risk approach on the relative scale by 25% and 46%, respectively, and on the absolute scale by 2% and 6%, respectively.

CONCLUSIONS

Predictors of various causes of death differ in HD patients. The proposed prediction model for SCD accounts for competing causes of death. External validation of this model is required.

Improving ascertainment of sudden cardiac death in patients with end stage renal disease

BACKGROUND AND OBJECTIVES

Data collected by the US Renal Data System (USRDS) identify sudden cardiac death (SCD) as the leading cause of death among hemodialysis patients. However, evidence suggests that clinical events captured on the USRDS death notification form may be inaccurate. A new method for classifying SCD was recently developed to enhance the accuracy of SCD classification. This study examined the performance characteristics of this refined definition using a cohort of hemodialysis patients who experienced a witnessed SCD as the reference standard.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This is a retrospective cohort study of 363 patients who experienced a witnessed SCD in US Gambro (DaVita) outpatient dialysis clinics. Sensitivity of SCD defined by death notification forms and SCD defined using additional administrative sources was compared. Clinical data recorded near time of death were also examined.

RESULTS

Existing USRDS death notification forms reported 70.8% of witnessed SCD as "cardiac arrest/cause unknown" or "arrhythmia." The refined definition significantly improved identification to 83.8% of witnessed SCD events (P<0.001). Verified SCD cases that were not identified by either definition were more likely to be reported on the death notification form as death due to myocardial infarction, hyperkalemia, sepsis, malignancy, or unknown cause.

CONCLUSIONS

Compared with the death notification form alone, the refined SCD definition significantly improves the sensitivity of reporting of witnessed SCD occurring within outpatient hemodialysis clinics. More accurate reporting of cardiac events by clinicians and refinements to existing death notification forms may further improve recognition and understanding of SCD.

Prehemodialysis care by dietitians and first-year mortality after initiation of hemodialysis

BACKGROUND

Since January 2002, Medicare has provided payment for medical nutrition therapy for patients with chronic kidney disease. Few patients receive dietary counseling before end-stage renal disease onset; whether such counseling is associated with improved outcomes is unknown.

STUDY DESIGN

Retrospective cohort analysis.

SETTING & PARTICIPANTS

Patients who initiated hemodialysis therapy on June 1, 2005, to May 31, 2007, in the United States for whom predialysis dietitian care was reported on the Centers for Medicare & Medicaid Services Medical Evidence Report.

PREDICTOR

Dietitian care before end-stage renal disease onset.

OUTCOME

Time to death.

MEASUREMENTS

Propensity score for dietitian care calculated using logistic regression; Cox regression analysis used to compare time to death by predialysis dietitian care overall and stratified by tertiles of propensity score, adjusting for baseline characteristics.

RESULTS

Most patients (88%) received no dietitian care; 9% received dietitian care for 12 months or less, and 3% received dietitian care for more than 12 months before dialysis therapy initiation (total N = 156,440). Predialysis dietitian care was associated independently with higher albumin and lower total cholesterol levels at dialysis therapy initiation. There was evidence of an independent association between predialysis dietitian care for longer than 12 months and decreased mortality during the first year on dialysis therapy for the second tertile of propensity score. Adjusted mortality HRs were 1.16 (95% CI, 0.44-3.09; P = 0.8), 0.81 (95% CI, 0.71-0.93; P = 0.002), and 0.93 (95% CI, 0.86-1.01; P = 0.1) in the first, second, and third tertiles of propensity score, respectively.

LIMITATIONS

Information for dietitian care was missing for 18.6% of Medical Evidence Reports and has low sensitivity; including only incident dialysis patients precluded evaluation of an association between dietitian care and chronic kidney disease progression; the observational design allowed the possibility of residual confounding.

CONCLUSIONS

Our study suggests an independent association between predialysis dietitian care for more than 12 months and lower mortality during the first year on dialysis therapy.

Design and implementation of the Canadian Kidney Disease Cohort Study (CKDCS): A prospective observational study of incident hemodialysis patients

Background

Many nephrology observational studies use renal registries, which have well known limitations. The Canadian Kidney Disease Cohort Study (CKDCS) is a large prospective observational study of patients commencing hemodialysis in five Canadian centers. This study focuses on delineating potentially reversible determinants of adverse outcomes that occur in patients receiving dialysis for end-stage renal disease (ESRD).

Methods/Design

The CKDCS collects information on risk factors and outcomes, and stores specimens (blood, dialysate, hair and fingernails) at baseline and in long-term follow-up. Such specimens will permit measurements of biochemical markers, proteomic and genetic parameters (proteins and DNA) not measured in routine care. To avoid selection bias, all consenting incident hemodialysis patients at participating centers are enrolled, the large sample size (target of 1500 patients), large number of exposures, and high event rates will permit the exploration of multiple potential research questions.

Preliminary Results

Data on the baseline characteristics from the first 1074 subjects showed that the average age of patients was 62 (range; 50-73) years. The leading cause of ESRD was diabetic nephropathy (41.9%), and the majority of the patients were white (80.0%). Only 18.7% of the subjects received dialysis in a satellite unit, and over 80% lived within a 50 km radius of the nearest nephrologist's practice.

Discussion

The prospective design, detailed clinical information, and stored biological specimens provide a wealth of information with potential to greatly enhance our understanding of risk factors for adverse outcomes in dialysis patients. The scientific value of the stored patient tissue will grow as new genetic and biochemical markers are discovered in the future.

Mortality associated with low serum sodium concentration in maintenance hemodialysis

BACKGROUND

low serum sodium concentrations are associated with an increased risk of death in the general population, but causality is uncertain due to confounding from clinical conditions such as congestive heart failure and cirrhosis, in which hyponatremia results from elevated levels of arginine vasopressin.

METHODS

to examine the association between predialysis serum sodium concentration and mortality in patients undergoing hemodialysis for end-stage renal disease, a condition in which arginine vasopressin does not affect water excretion and osmoregulation, we studied 1549 oligoanuric participants in the HEMO study, a randomized controlled trial of hemodialysis patients examining the effect of hemodialysis dose and flux. We used proportional hazards models to compare the risk of death according to predialysis serum sodium concentration.

RESULTS

considered as a continuous variable, each 4-mEq/L increment in baseline predialysis serum sodium concentration was associated with a hazard ratio for all-cause mortality of 0.84 (95% confidence interval (CI), 0.78-0.90). Multivariable adjustment for demographic, clinical, laboratory, and dialysis-specific covariates, including ultrafiltration volume, did not appreciably change the results (hazard ratio for all-cause mortality of 0.89; 95% CI, 0.82-0.96). the results also were consistent in time-updated analyses using repeated measures of serum sodium and other relevant covariates.

CONCLUSION

Lower predialysis serum sodium concentration is associated with an increased risk of death. Considering the unique physiology in the dialysis population, these findings raise the possibility that hyponatremia itself may be a causal determinant of mortality in the broader population.

Validation of CKD and related conditions in existing data sets: A systematic review

BACKGROUND

Accurate classification of individuals with kidney disease is vital to research and public health efforts aimed at improving health outcomes. Our objective is to identify and synthesize published literature evaluating the accuracy of existing data sources related to kidney disease.

STUDY DESIGN

A systematic review of studies seeking to validate the accuracy of the underlying data relevant to kidney disease.

SETTING & POPULATION

US-based and international studies covering a wide range of both outpatient and inpatient study populations.

SELECTION CRITERIA FOR STUDIES

Any English-language study investigating the prevalence or cause of kidney disease, existence of comorbid conditions, or cause of death in patients with chronic kidney disease (CKD). All definitions and stages of CKD, including end-stage renal disease (ESRD), were accepted.

INDEX TESTS

Presence of a kidney disease-related variable in existing data sets, including administrative data sets and disease registries.

REFERENCE TESTS

Presence of a kidney disease-related variable defined using laboratory criteria or medical record review.

RESULTS

30 studies were identified. Most studies investigated the accuracy of kidney disease reporting, comparing coded renal disease with that defined using estimated glomerular filtration rate. The sensitivity of coded renal disease varied widely (0.08-0.83). Specificity was higher, with all studies reporting values ≥0.90. Studies evaluating the cause of CKD, comorbid conditions, and cause of death in patients with CKD used ESRD or transplant populations exclusively, and accuracy was highly variable compared with ESRD registry data.

LIMITATIONS

Only English-language studies were evaluated.

CONCLUSIONS

Given the heterogeneous results of validation studies, a variety of attributes of existing data sources, including the accuracy of individual data items within these sources, should be considered carefully before use in research, quality improvement, and public health efforts.

Meeting KDOQI guideline goals at hemodialysis initiation and survival during the first year

BACKGROUND AND OBJECTIVES

To determine, in a national cohort of incident hemodialysis patients, whether meeting a greater number of National Kidney Foundation Kidney Disease Outcomes Quality Initiative (KDOQI) guideline goals at dialysis initiation was independently associated, in a graded manner, with lower first-year mortality rates.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Patients who initiated hemodialysis between June 1, 2005, and May 31, 2007, in the US were included in this retrospective cohort analysis. Guidelines examined were (1) use of arteriovenous fistula or graft at initiation; (2) hemoglobin > or = 11 g/dl; and (3) albumin at goal. The primary predictor variable was number of guideline goals (zero, one, two, or three) met at dialysis initiation. Cox regression analysis was used to compare time to death, adjusting for baseline characteristics.

RESULTS

At dialysis initiation, 59%, 31%, 9%, and 1.6% of patients met zero, one, two, or three guideline goals, respectively (total n = 192,307). After multivariate adjustment, mortality hazard ratios (95% confidence intervals) were 0.81 (0.80 to 0.83) for patients who met one, 0.53 (0.51 to 0.56) for patients who met two, and 0.34 (0.30 to 0.39) for patients who met three guideline goals, compared with patients who met none. Meeting each individual goal was also associated with lower mortality.

CONCLUSIONS

These findings suggest a graded association between meeting a greater number of evidence-based guideline goals at dialysis initiation and lower risk of death during the first year on dialysis.

Systolic blood pressure and mortality in prevalent haemodialysis patients in the HEMO study

Previous studies of blood pressure and mortality in haemodialysis have yielded mixed results, perhaps due to confounding by comorbid conditions. We hypothesized that after improved accounting for confounding factors, higher systolic blood pressure (SBP) would be associated with higher all-cause mortality. We conducted a secondary analysis of data from the haemodialysis study, a randomized trial in prevalent haemodialysis patients. We used three proportional hazard models to determine the relative hazard at different levels of SBP: (1) Model-BL used baseline SBP; (2) Model-TV used SBP as a time-varying variable; and (3) Model-TV-Lag added a 3-month lag to Model-TV to de-emphasize changes in SBP associated with acute illness. In all the models, pre-dialysis SBP <120 mm Hg was associated with a higher risk of mortality compared with the referent group (140-159 mm Hg); higher pre-dialysis SBP was not associated with higher risk of mortality. In conclusion, we observed a robust association between lower pre-dialysis SBP and higher risk for all-cause and cardiovascular mortality in a well-characterized cohort of prevalent haemodialysis patients. Randomized clinical trials are needed to define optimal blood pressure targets in the haemodialysis population.

Inpatient hemodialysis initiation: reasons, risk factors and outcomes

BACKGROUND/AIMS

Inpatient initiation of chronic hemodialysis is considered undesirable because of cost and possible harms of hospitalization. We examined the patient characteristics and outcomes associated with inpatient initiation.

METHODS

In a prospective cohort study of incident dialysis patients, the independent association of inpatient hemodialysis initiation with patient outcomes was assessed in multivariable analyses with adjustment for patient characteristics and propensity for inpatient initiation.

RESULTS

A total of 410 of 652 (63%) hemodialysis patients began as inpatients; uremia and volume overload were the most commonly documented reasons. Compared to outpatients, inpatients were more likely to be unmarried, report less social support, have multiple comorbidities and be referred to a nephrologist 4 months or less prior to initiation. Inpatient initiation was protective for subsequent all-cause hospitalization (incidence rate ratio (IRR) = 0.92, confidence interval (CI) 0.89-0.94); this was most pronounced among those who had the highest propensity for inpatient initiation (IRR = 0.66, CI 0.56-0.78), including those referred late to nephrology. Similar results were found for infectious hospitalization. Mortality [hazard ratio = 1.03, CI 0.82-1.30] and cardiovascular events were not significantly different for inpatients versus outpatients.

CONCLUSION

Inpatient hemodialysis initiation has a protective association with hospitalization among those patients referred late to nephrology, with multiple comorbidities and/or little social support.

Peripheral vascular disease-related procedures in dialysis patients: predictors and prognosis

BACKGROUND AND OBJECTIVES

Peripheral vascular disease (PVD) is prevalent among dialysis patients, and many dialysis patients undergo PVD-related procedures. We aimed to examine the risk factors for and prognosis after such procedures in the dialysis setting.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In a national prospective cohort study of 1041 incident dialysis patients, we examined the factors that are associated with PVD procedures (lower extremity amputations and bypasses) after the start of dialysis. Adjusted risk for PVD procedures of various factors was estimated using multivariable Cox proportional hazards models. Incidence rates of subsequent cardiovascular events, infectious hospitalizations, PVD- and cardiovascular disease-related mortality, and all-cause mortality were compared for those with and without a PVD procedure.

RESULTS

Overall, 217 (21%) patients underwent a PVD procedure after the start of dialysis. For those without diabetes, only PVD history (relative hazard [RH] 2.9; 95% confidence interval [CI] 1.3 to 6.6) and increased fibrinogen (RH 1.2; 95% CI 1.0 to 1.5) predicted PVD procedures. For those with diabetes, increased serum phosphate (RH 1.2; 95% CI 1.1 to 1.4), along with decreased albumin, increased C-reactive protein and fibrinogen, and lower SBP, was associated with risk for PVD procedures. Of those who had a procedure compared with those who did not, 68 versus 30% experienced a subsequent cardiovascular event, 85 versus 66% an infectious hospitalization, 11 versus 2% a PVD-related death, and 81 versus 59% all-cause death (mean follow-up 3.0 yr).

CONCLUSIONS

Prognosis after PVD procedures is poor, and providers should be aware that risk factors for PVD procedures may differ by diabetes status.

Cerebrovascular disease incidence, characteristics, and outcomes in patients initiating dialysis: the choices for healthy outcomes in caring for ESRD (CHOICE) study

BACKGROUND

Stroke is the third most common cause of cardiovascular disease death in patients on dialysis therapy; however, characteristics of cerebrovascular disease, including clinical subtypes and subsequent consequences, have not been well described.

STUDY DESIGN

Prospective national cohort study, the Choices for Healthy Outcomes in Caring for End-Stage Renal Disease (CHOICE) Study.

SETTINGS & PARTICIPANTS

1,041 incident dialysis patients treated in 81 clinics enrolled from October 1995 to July 1998, followed up until December 31, 2004.

PREDICTOR

Time from dialysis therapy initiation.

OUTCOMES & MEASUREMENTS

Cerebrovascular disease events were defined as nonfatal (hospitalized stroke and carotid endarterectomy) and fatal (stroke death) events after dialysis therapy initiation. Stroke subtypes were classified by using standardized criteria from the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) system. The incidence of cerebrovascular event subtypes was analyzed by using time-to-event analyses accounting for competing risk of death. Clinical outcomes after stroke were abstracted from medical records.

RESULTS

165 participants experienced a cerebrovascular event with an overall incidence of 4.9 events/100 person-years. Ischemic stroke was the most common (76% of all 200 events), with cardioembolism subtype accounting for 28% of the 95 abstracted ischemic events. Median time from onset of symptoms to first stroke evaluation was 8.5 hours (25th and 75th percentiles, 1 and 42), with only 56% of patients successfully escaping death, nursing home, or skilled nursing facility.

LIMITATIONS

Relatively small sample size limits power to determine risk factors.

CONCLUSIONS

Cerebrovascular disease is common in dialysis patients, is identified late, and carries a significant risk of morbidity and mortality. Stroke etiologic subtypes on dialysis therapy are multifactorial, suggesting risk factors may change the longer one has end-stage renal disease. Additional studies are needed to address the poor prognosis through prevention, early identification, and treatment.

PSYCHOSOCIAL FACTORS IN PATIENTS WITH CHRONIC KIDNEY DISEASE: The Psychiatric Landscape of Withdrawal

Withdrawal from dialysis is an appropriate decision for situations in which the burdens of treatment outweigh the benefits. Alternately, it can be viewed as a public health problem and suicide equivalent that contributes to the high mortality of end-stage renal disease (ESRD). More than one in five deaths of patients with ESRD are preceded by dialysis cessation, and approximately 15,000 Americans died last year following a determination to stop this life-support treatment. This article discusses what is known about the psychosocial aspects of the patients who terminate dialysis, the role of depression and other psychiatric disorders, the family perspective, and the relationship of these decisions to suicide.

Cause-specific mortality of dialysis patients after coronary revascularization: why don't dialysis patients have better survival after coronary intervention?

INTRODUCTION

The risk of death after coronary revascularization is markedly higher for dialysis patients than for the general population and the cause is inadequately explained. We analyzed cause-specific mortality of dialysis patients after coronary revascularization.

METHODS

This was a retrospective analysis of dialysis patients hospitalized for first surgical coronary revascularization after renal replacement therapy initiation from 1 January 1999 to 31 December 2002. Patients were identified from the US Renal Data System database (n = 1,516,251) by the International Classification of Diseases, Ninth Edition, Clinical Modification code for coronary artery bypass (CAB) surgery (36.1x). Endpoints were deaths due to all causes, all cardiac causes, cardiac arrest or arrhythmia, myocardial infarction, infection and other causes. Cause-specific mortality information was obtained from Centers for Medicare & Medicaid Services End-Stage Renal Disease Death Notification form (CMS 2746-U3).

RESULTS

For CAB patients (n = 5830), the all-cause mortality rate was 290 per 1000 patient-years and the rate for arrhythmically mediated deaths was 76 per 1000 patient-years. The largest cause of attributable mortality is cardiac arrest or arrhythmia, accounting for approximately one-fourth of all-cause mortality.

CONCLUSIONS

The risk of arrhythmically mediated death may contribute to poor long-term outcomes after coronary revascularization in dialysis patients. A treatment strategy employing coronary revascularization and other interventions to reduce the sudden cardiac death risk might improve long-term survival.

Haemodialysis and peritoneal dialysis patients admitted to intensive care units

Hutchison and colleagues report a 10-year experience of dialysis patients admitted to intensive care units (ICUs) in the UK excluding Scotland. Their study is the largest published so far and raises issues of interest to both ICU physicians and nephrologists. Overall, the dialysis patients, although sicker on admission and having pre-existing co-morbidities, do as well as other ICU patients. Their clinical progress after leaving the ICU, however, is less good than for other ICU patients, raising the possibility that the patients might be leaving too early, or perhaps that dialysis patients should be discharged to a high-dependency unit rather than go direct to a renal ward. All in all, the paper by Hutchison and colleagues provides a useful foundation for planning the critical care management of dialysis patients in the UK and elsewhere.