Hemoglobin variability and mortality in ESRD

Beneficial dose conversion after switching from higher doses of shorter-acting erythropoiesis-stimulating agents to C.E.R.A in CKD patients in clinical practice: MINERVA Study

PURPOSE

To assess whether the correction dose recommended by the summary of product characteristics was adequate and to confirm the adequacy of the recommended conversion dosing strategies from shorter-acting erythropoiesis-stimulating agents (ESAs) to continuous erythropoietin receptor activator (C.E.R.A) in anaemic chronic kidney disease (CKD) patients in the clinical setting.

METHODS

This was a 12-month, multicenter, prospective, observational study in anaemic CKD patients on haemodialysis and not on dialysis receiving C.E.R.A (at least one dose).

RESULTS

A total of 227 patients were included (not on dialysis; n = 142; haemodialysis: n = 85). The present analysis was conducted on ESA-naïve patients (not on dialysis: n = 31) and patients switched from other ESA (not on dialysis: n = 63; haemodialysis: n = 57). Both on and not on dialysis patients switched from other ESA received lower starting C.E.R.A doses than those recommended, and remained stable during the 12-month period. The higher the previous ESA dose was, the more beneficial the C.E.R.A dose conversion factor was. The proportion of patients with stable haemoglobin within the target range (11-13 g/dL) did not vary during the 12-month period both in nondialysis CKD patients and in those undergoing dialysis [baseline: 42 (66.7 %) and 34 (59.6 %); month 6: 21 (55.3 %) and 26 (50.0 %); month 12: 20 (64.5 %) and 25 (69.4 %), respectively]. In naïve patients, the mean weight-adjusted C.E.R.A dose during the study (1.19 ± 0.49 µg/kg/month) was similar to the recommended one. C.E.R.A was well tolerated.

CONCLUSIONS

Conversion from shorter-acting ESAs to C.E.R.A doses lower than those recommended can efficiently maintain target haemoglobin levels both in nondialysis and haemodialysis CKD patients, particularly when switching from higher ESA doses. A monthly C.E.R.A dose of 1.2 µg/Kg seems adequate for anaemia correction.

Cost savings using a protocol approach to manage anemia in a hemodialysis unit

BACKGROUND

National guidelines recommend using anemia management protocols to guide treatment. The objective of this study was to determine if an anemia management protocol would improve hemoglobin (Hgb) indices in hemodialysis patients and to measure whether the protocol would reduce the use and cost of darbepoetin alfa (DBO) and intravenous (IV) iron in hemodialysis patients.

METHODS

An anemia management protocol was created and implemented for hemodialysis patients at our institution. A retrospective observational review of the use of DBO and IV iron as well as changes in Hgb, transferrin saturation and ferritin in 174 patients was conducted 6 months before and after implementation of the anemia protocol.

RESULTS

The number of Hgb measurements in the target range increased from 44.3 to 46.0% (p = 0.48) after protocol implementation. The mean weekly dose of DBO was reduced from 34.56 ± 31.12 to 31.11 ± 28.64 μg post-protocol implementation (p = 0.011), which translated to a cost savings of USD 41,649 over 6 months. The mean monthly IV iron dose also decreased from 139.56 ± 98.83 to 97.65 ± 79.05 mg (p < 0.005), a cost savings of USD 18,594 over the same time period.

CONCLUSION

The use of an anemia management protocol resulted in the deprescribing of DBO and iron agents while increasing the number of patients in the target Hgb range, which led to significant cost savings in the treatment of anemia.

Does erythropoietin cause hemoglobin variability--is it 'normal'?

Hemoglobin variability (Hb-var) in patients with chronic kidney disease has been stipulated to be a result of exogenous treatment with erythropoiesis stimulating agents (ESA) and has been related to mortality in dialysis patients. We hypothesized the existence of Hb-var independent of ESA administration and compared it to that in healthy adults using data from the Scripps-Kaiser and NHANES III databases. We studied the Hb-var in 1571 peritoneal dialysis patients which included 116 patients not requiring treatment with erythropoietin. We systematically studied the differences between the groups that needed ESA therapy and those who did not. White race and male sex were significant predictors of need for erythropoietin therapy. We found peritoneal dialysis patients to exhibit significantly increased Hb-var independent of treatment with exogenous erythropoietin (0.99 gm/dL vs. 1.17 gm/dL, p-value<0.001). We found age to be a significant determinant of Hb-var in the ESA treated group. Hb-var in younger patients (<30 years) was increased by 50% compared to young healthy adults. The Hb-var in elderly (>60 years) peritoneal dialysis patients was similar to that seen in healthy elders, suggesting similarity with anemia of aging. We conclude that exogenous ESA administration does not explain Hb-var entirely but may enhance it. Intrinsic factors affecting erythropoiesis including age may be the major determinants of Hb-var.

Determinants of hemoglobin variability in stable peritoneal dialysis patients

PURPOSE

Significant within-patient hemoglobin (Hb) level variability is well recognized in particularly hemodialysis patients. Several factors such as hospitalizations, intercurrent diseases and IV iron therapy are found to be related to Hb variability (Hb-var). In this observational study, we aimed to identify predictors and outcome of Hb-var in peritoneal dialysis (PD) patients without hospitalization, intercurrent disease and IV iron therapy during the study period.

METHODS

All patients were in the maintenance phase of short-acting erythropoiesis-stimulating agents (ESAs) therapy. The target range of Hb was 11-12 g/dL according to KDOQI Guidelines in 2007. The desired range of Hb was 11-12.5 g/dL. Patients' demographic and laboratory data were collected at baseline. Atherosclerotic disease was assessed using carotid intima-media thickness (CIMT). We assessed Hb variability with various methods using SD Hbmean, SD Hbrange and the velocity of Hb change. Hb deflectpositive, Hb deflectnegative, Hb values and ESA dosing were recorded monthly for 6 months.

RESULTS

This study included 50 prevalent PD patients (mean age 46.9 ± 13.7 years, 25 women). The mean velocity of Hb change was negatively correlated with age and positively correlated with frequent ESA dose changes. Higher albumin and residual renal function (RRF) were also positively correlated with Hb deflectpositive. Patients with CIMT ≥0.7 cm had lower SD Hb range compared to CIMT <0.7 cm. Cumulative survival was better in patients with Hb levels consistently ≥10 g/dL compared to patients who had Hb <10 g/dL for at least 1 month. However, Hb-var was not associated with mortality.

CONCLUSIONS

In PD patients without hospitalization, intercurrent disease(s) or IV iron therapy, young age, higher albumin or RRF and lower CIMT were associated with greater oscillations in response to ESA therapy. Careful and appropriate ESA dose changes considering these parameters could minimize Hb variability in these patients.

Effect of hemoglobin variability on mortality and some cardiovascular parameters in hemodialysis patients

BACKGROUND AND OBJECTIVES

Most hemodialysis patients show hemoglobin fluctuations between low-normal and high levels. This hemoglobin variability may cause left ventricle hypertrophy and may increase mortality as well. Recently, many studies were designed to evaluate the effect of hemoglobin variability on mortality but results were conflicting. We aimed to investigate the effect of hemoglobin variability on mortality and some cardiovascular parameters in hemodialysis population.

DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS

Hundred and seventy-five prevalent hemodialysis patients classified into three hemoglobin variability groups according to their hemoglobin levels throughout 24 month observation period: Low-Normal, Low-High, Normal-High. Groups were compared in terms of laboratory, demographical data and mortality rates, initial and the end of 24 month echocardiographic data. Initial and last echocardiographic data were compared within groups in terms of left ventricle mass index increase.

RESULTS

Mortality rates and cardiovascular risk factors such as coronary heart disease, diabetes mellitus and hypertension that may affect mortality were same between three groups. There was no significant difference between three groups in terms of echocardiographic and laboratory parameters. Only Low-High group showed significant increase on left ventricle mass index when initial and last echocardiographic parameters were compared.

CONCLUSIONS

Consistent with previous studies, we found that most of the patients exhibited hemoglobin variability and our study is consistent with some of the studies that did not find any relationship between hemoglobin variability and mortality. Firstly, in this study based on objective data, it was shown that hemoglobin variability has adverse effect on left ventricle geometry independent from anemia.

Low hemoglobin levels and hypo-responsiveness to erythropoiesis-stimulating agent associated with poor survival in incident Japanese hemodialysis patients

Although erythropoiesis-stimulating agents (ESAs) are effective at treating anemia, the association between hemoglobin (Hb) levels and survival is still unclear, especially for the incident Japanese hemodialysis (HD) population. The Japan Erythropoietin Treatment (JET) Study is an open multi-center, prospective, observational study designed to evaluate the relationship between the maintenance of Hb levels and new HD patient prognosis after the first administration of epoetin beta. Landmark analyses were performed to examine the relationship between Hb levels at 6 months and survival. Among a total of 10,310 patients, 6631 completed the initial 6 months of epoetin beta treatment (induction phase) and were followed up for a further 2.5 years (maintenance phase). Three-year survival rate of patients with <9 g/dL Hb levels after 6 months was 74.1%, which was significantly lower than 89.3% for patients with Hb levels 10 to 11 g/dL; the adjusted hazard ratio (HR) was 2.08 (95% CI, 1.57-2.77; P < 0.0001). Moreover, the 3-year survival rate for poor responders defined by Hb levels <10 g/dL and weekly epoetin beta doses ≥ 9000 IU during the induction phase was 71.6%, which was significantly lower than 89.4% for the group, which had Hb levels 10 to 11 g/dL excluding poor responders and those with excursion; the HR was 1.71 (95% CI, 1.13-2.60; P = 0.0118). Adverse events related to the treatment were reported in 71 of 10,310 patients (0.69%). These findings suggest that the achieved low Hb levels and poor response to ESA therapy are significantly associated with high mortality.

Pre-emptive replacement of water treatment components improves responsiveness to erythropoiesis-stimulating agents in maintenance haemodialysis patients: a quality improvement report

Hypo-responsiveness to erythropoiesis-stimulating agents (ESAs) has been associated with increased mortality. We examined the effect of water treatment component replacement on declining ESA responsiveness in the absence of chemical or microbiological standards failure. Pre-emptive renewal of the water treatment system supplying 802 standard-flux haemodialysis patients resulted in a significant rise in haemoglobin from (mean ± SD) 12.1 ± 1.2 to 12.3 ± 1.0 g/dl (p < 0.0001), accompanied by a significant decrease in prescribed dose of darbepoetin alfa from 47.9 ± 27.3 to 44.7 ± 27.6 μg/week (p < 0.0001). ESA responsiveness improved significantly from 0.060 ± 0.041 to 0.055 ± 0.040 μg/kg/g · dl(-1) (p < 0.0001) and the number of patients no longer requiring ESA therapy increased threefold. These benefits were derived in the absence of haemolysis or significant changes in water quality. Renewal of water system components should be conducted even in the absence of proven microbiological and chemical failure.

Comparison between short- and long-acting erythropoiesis-stimulating agents in hemodialysis patients: target hemoglobin, variability, and outcome

Purpose

Maintaining target hemoglobin (Hb) with minimal variability is a challenge in hemodialysis (HD) patients. The aim of this study is to compare the long- and short-acting erythropoietin-stimulating agents such as Aranesp and Eprex in achieving these targets.

Methods

Randomized, prospective, open-labeled study of 24 weeks includes stable patients on HD >3 months, age >18 years, and on Eprex for >3 months. Patients were randomized into two groups: A-(Aranesp group):HD patients on Eprex Q TIW or BIW were converted to Aranesp Q weekly, by using the conversion factor of 200:1 and those on Eprex Q weekly to Aranesp Q 2 weeks; B-(Eprex group):patients continued on Eprex treatment. Hemoglobin target was set at (105–125 g/l). Primary end points were percentage of patients achieving target Hb, hemoglobin variability, and number of dose changes in each group.

Results

This study consisted of 139 HD patients: 72 in the Aranesp and 67 in the Eprex—mean (SD) age 54 (16.2) years, 77 (55 %) males. About 46 % were diabetic. Target Hb achieved in 64.8 % of the Aranesp and 59.7 % in the Eprex (p = 0.006). Hb variability was less frequent in the Aranesp group (p = 0.2). Mean number of dose changes was 1.3 (0.87) in the Aranesp and 1.9 (1.2) in the Eprex (p < 0.001). There was 1 vascular access thrombosis in the Aranesp and 8 in the Eprex (p < 0.001). There was no difference in hospitalization and death number between the 2 groups.

Conclusions

Aranesp Q weekly or every 2 weeks is more efficient in achieving target Hb, with less dose changes and minor vascular access complications.

Biomedical system dynamics to improve anemia control with darbepoetin alfa in long-term hemodialysis patients

OBJECTIVE

To determine the value of a biomedical system dynamics (BMSD) approach for optimization of anemia management in long-term hemodialysis patients because elevated hemoglobin levels and high doses of erythropoiesis-stimulating agents (ESAs) may negatively affect survival in this population.

PATIENTS AND METHODS

A model of erythropoiesis and its response to ESAs on the basis of a BMSD method (Mayo Clinic Anemia Management System [MCAMS]) was developed. Thereafter, an open-label, prospective, nonrandomized practice quality improvement project was performed with retrospective analysis in 8 community-based outpatient hemodialysis facilities. All prevalent hemodialysis patients seen from January 1, 2007, through December 31, 2010 (300-342 patients per month), were included with darbepoetin as the ESA. The primary outcome was the percentage of patients who attained the desired hemoglobin level. Secondary outcome measures included the percentage of patients with hemoglobin values above the desired range and mean dose of darbepoetin used.

RESULTS

The 3 treatment periods were (1) standard ESA protocol in 2007, (2) transition to the MCAMS (2008 to June 2009), and (3) stability period with the MCAMS used in all hemodialysis facilities (2009 to 2010). In the first 6 months of 2007, 69% of patients were in the desired range and 26% were above the range. In comparison, during the first 5 months of 2010, 83% were in and 6% were above the range (P<.001). The mean monthly darbepoetin dose per patient decreased from 304 μg in 2007 to 173 μg by the second half of 2009 (P<.001).

CONCLUSION

With the introduction of the MCAMS, more patients had hemoglobin levels in the desired range and fewer patients exceeded the target range, with a concomitant 40% reduction in darbepoetin use.

Renal anemia control in Lithuania: influence of local conditions and local guidelines

Erythropoietin stimulating agents had a long haul in Lithuania—we had no epoetin till 1994 and there was no intravenous iron in 2001–2004. The aim of this study was to assess the changes of renal anemia control in hemodialysis patients from early independence of Lithuania till nowadays and to evaluate the link of anemia with hospitalization rates and survival and hemoglobin variability in association with mortality. In December of each year since 1996 all hemodialysis centers have been visited and data has been collected using special questionnaires. The history of renal anemia control in Lithuania was complicated; however, a significant improvement was achieved: 54.7% of hemodialysis patients reached the target hemoglobin; all patients have a possibility of treatment with epoetin and intravenous iron. The involuntary experiment with an intravenous iron occurred in Lithuania because of economic reasons and confirmed the significant role of intravenous iron in the management of renal anemia. Hemoglobin below 100 g/L was associated with a 2.5-fold increase in relative risk of death and 1.7-fold increase in relative risk of hospitalization in Lithuanian hemodialysis patients. Although hemoglobin variability was common in Lithuanian hemodialysis patients, we did not find the association between hemoglobin variability and all-cause mortality in our study.

Beyond linear methods of data analysis: time series analysis and its applications in renal research

Analysis of temporal trends in medicine is needed to understand normal physiology and to study the evolution of disease processes. It is also useful for monitoring response to drugs and interventions, and for accountability and tracking of health care resources. In this review, we discuss what makes time series analysis unique for the purposes of renal research and its limitations. We also introduce nonlinear time series analysis methods and provide examples where these have advantages over linear methods. We review areas where these computational methods have found applications in nephrology ranging from basic physiology to health services research. Some examples include noninvasive assessment of autonomic function in patients with chronic kidney disease, dialysis-dependent renal failure and renal transplantation. Time series models and analysis methods have been utilized in the characterization of mechanisms of renal autoregulation and to identify the interaction between different rhythms of nephron pressure flow regulation. They have also been used in the study of trends in health care delivery. Time series are everywhere in nephrology and analyzing them can lead to valuable knowledge discovery. The study of time trends of vital signs, laboratory parameters and the health status of patients is inherent to our everyday clinical practice, yet formal models and methods for time series analysis are not fully utilized. With this review, we hope to familiarize the reader with these techniques in order to assist in their proper use where appropriate.

Association between hemoglobin, calcium, and lactate dehydrogenase variability and mortality among metastatic renal cell carcinoma

PURPOSE

There are no robust data on hemoglobin (Hb), lactate dehydrogenase (LDH), and calcium variability for overall survival (OS) in patients with metastatic renal cell carcinoma (mRCC) treated with vascular endothelial growth factor (VEGF)-targeted therapy. We aim to evaluate prognostic implications of Hb, LDH, and calcium variability and establish a novel risk stratification model in RCC patients receiving targeted therapies.

METHODS

We retrospectively studied an unselected cohort of patients with mRCC, who were treated with tyrosine kinase inhibitors. We assessed LDH variability, Ca variability, and Hb variability with various methods using standard deviation and fluctuation across thresholds. Kaplan-Meier and log-rank analyses were employed on OS and multivariate Cox proportional hazard model analyzed clinical parameters for their prognostic relevance.

RESULTS

A total of 59 patients intermediate-risk group according to the Memorial Sloan-Kettering Cancer Center with mRCC who had early progressed after first-line therapy with interferon-α were included in this retrospective single-center study conducted between February 2008 and December 2011. The mean Hb was 12.4 g/dl (min-max 9.1-15.2) throughout the study. Multivariable-adjusted Cox regression showed that patients in the consistently low-Hb group and patients in the low-amplitude and high-amplitude groups had a statistically significant increase in risk compared with patients who were consistently on target (HR 4.1; 95 % CI 1.3-12.9 and HR 2.9; 95 % CI 1.05-8.1 and HR 4.4; 95 % CI 1.7-11.1, respectively). On the other hand, the higher mean LDH (LDH more than 1 >upper limit of normal) was associated with OS. LDH variability and Ca variability were not associated with mortality.

CONCLUSIONS

In patients with mRCC treated with VEGF-targeted therapy, Hb variability and mean LDH level might be associated with OS. This should be investigated prospectively.

Between subjects variability in haemoglobin and dose are not associated with the erythropoiesis-stimulating agent used to treat anaemia in dialysis: a meta-analysis

AIMS

We aimed to compare mean and between subject variability in haemoglobin (Hb) and erythropoiesis-stimulating agents (ESA) dose across the ESA compounds used to treat anaemia in dialysis patients.

METHODS

We performed a meta-analysis of randomized trials evaluating ESA in adult patients with chronic kidney disease on dialysis (target Hb 9-13.5 g dl(-1)), and compared mean Hb and its standard deviation (SD), and ESA dose and its coefficient of variation (CV) between the different agents [rHuEPO alfa or beta, darbepoetin alfa, pegylated-epoetin beta (PEG-EPO) or other epoetins]. The effect of route and frequency of administration, frequency of dose adjustments, study blinding and type, baseline value, Hb target and sampling frequency were also assessed.

RESULTS

Among 4983 patients from 16 studies, pooled Hb mean and SD during the evaluation phase were 11.5 g dl(-1) (95% CI 11.3, 11.7) and 0.99 g dl(-1) (0.88, 1.09), respectively. The Hb mean and SD were not significantly influenced by the covariates tested. Only Hb SD was significantly lower in maintenance studies relative to correction studies. No differences in mean ESA dose and CV were found across the covariates, except that PEG-EPO monthly dose was 42% higher than the every 2 weeks dose and the rHuEPO i.v. dose was 32% higher than the s.c. dose.

CONCLUSIONS

Between subject variability in haemoglobin and ESA dose in dialysis patients is not associated with the type of ESA, nor with the dosing interval or route of administration, except for higher dose requirements in PEG-EPO monthly administration relative to every 2 weeks or rHuEPO i.v. relative to s.c.

Haemoglobin variability in the early post-transplant period: association with graft survival and mortality

AIM

Haemoglobin (Hb) variability is associated with poor survival in patients with chronic kidney disease. Association of Hb variability after kidney transplantation with patients' and graft survival has not been adequetly studied.

METHODS

This retrospective study used registry data to examine the association between Hb variability in the early post-transplant period (first 6 months) and graft survival after kidney transplantatin. Kaplan-Meier and Cox regression analyses were used for univariate and multivariate associations between mortality, death censored graft survival and the composite outcome of both, in 752 patients after kidney transplantation. Hb values were collected each month during the first 6 months after transplantation, and Hb variavility was calculated using the residual standard deviation method.

RESULTS

The highest quartile of Hb variability was associated with inferior graft and patients' survival in univariate (hazard ratio (HR) 2.18; 95% confidence interval (CI) 1.51 to 3.13; P < 0.001) and multivariate models (HR 1.5; 95% CI 1.029 to 2.18; P = 0.035). This association was mainly due to increased death censored graft failure in the high variability group (HR 2.75; 95% CI 1.73 to 4.38; P < 0.001) and (HR 1.67; 95% CI 1.023 to 2.74; P = 0.04) in the univariate and multivariate models, respectively. There was no association between Hb variability and the risk of death (HR 1.51; 95% CI 0.88 to 2.57; P = 0.132).

CONCLUSION

High Hb variability is independently associated with inferior graft survival in patients after kidney transplantation.

Prevalence of ventricular arrhythmia and its associated factors in nondialyzed chronic kidney disease patients

BACKGROUND AND OBJECTIVES

Sudden cardiac death is the most common cause of mortality in chronic kidney disease patients, and it occurs mostly due to ventricular arrhythmias. In this study, we aimed at investigating the prevalence of ventricular arrhythmia and the factors associated with its occurrence in nondialyzed chronic kidney disease patients.

DESIGN SETTING PARTICIPANTS AND MEASUREMENTS

This cross-sectional study evaluated 111 chronic kidney disease patients (estimated glomerular filtration rate 34.7±16.1 mL/min/1.73 m(2), 57±11.4 years, 60% male, 24% diabetics). Ventricular arrhythmia was assessed by 24-hour electrocardiogram. Left ventricular hypertrophy (echocardiogram), 24-hour ambulatory blood pressure monitoring, and coronary artery calcification (multi-slice computed tomography) and laboratory parameters were also evaluated.

RESULTS

Ventricular arrhythmia was found in 35% of the patients. Non-controlled hypertension was observed in 21%, absence of systolic decency in 29%, left ventricular hypertrophy in 27%, systolic dysfunction in 10%, and coronary artery calcification in 49%. Patients with ventricular arrhythmia were older (p<0.001), predominantly men (p = 0.009), had higher estimated glomerular filtration rate (p = 0.03) and hemoglobin (p = 0.005), and lower intact parathyroid hormone (p = 0.024) and triglycerides (p = 0.011) when compared to patients without ventricular arrhythmia. In addition, a higher left ventricular mass index (p = 0.002) and coronary calcium score (p = 0.002), and a lower ejection fraction (p = 0.001) were observed among patients with ventricular arrhythmia. In the multiple logistic regression analysis, aging, increased hemoglobin levels and reduced ejection fraction were independently related to the presence of ventricular arrhythmia.

CONCLUSIONS

Ventricular arrhythmia is prevalent in nondialyzed chronic kidney disease patients. Age, hemoglobin levels and ejection fraction were the factors associated with ventricular arrhythmia in these patients.

Hospitalization and mortality in hemodialysis patients: association with hemoglobin variability

BACKGROUND/AIMS

Hemodialysis patients show complications associated with low or high hemoglobin (Hb), which occur frequently in clinical practice. We sought to determine the clinical importance of these changes in Hb levels.

METHODS

From our clinic cohorts, we identified 1,634 who met inclusion criteria for analysis of hospitalization frequency and 1,953 analysis of mortality; many patients were in both groups. Hb excursions outside the target range (11-12.5 g/dl) were studied in relation to patient outcomes.

RESULTS

Hb measures below range were associated with more frequent hospitalization (p < 0.001), increased length of stay (p < 0.001), and increased mortality (p < 0.01), whereas Hb above range was associated with a reduced frequency of hospitalization (p < 0.01) and shorter length of stay (p < 0.01), and tended to be associated with reduced mortality.

CONCLUSIONS

Excursions below range were associated with negative outcomes, but excursions above range were either beneficial or neutral. Our findings indicate that clinicians should focus on low Hb as a negative indicator of patient status, whereas transient Hb above range is a marker for patient health and well-being.

Clinical management of nondialysis patients with chronic kidney disease: a retrospective observational study. Data from the SONDA study (Survey Of Non-Dialysis outpAtients)

Background

A lack of awareness of chronic kidney disease (CKD) often results in delayed diagnosis and inadequate treatment.

Purpose

The objective of this study was to assess the therapeutic management and outcome of nondialysis CKD patients.

Methods

Three hundred ninety-seven patients (54.9% males aged 67.5 ± 14.6 years) were retrospectively screened at the Nephrology Department, GB Grassi Hospital, Rome, Italy. After a baseline visit, patient data were collected every 6 months for a total of 24 months. Clinical characteristics were measured at baseline, then the following outcomes were measured every 6 months: staging of CKD, presence of concomitant diseases, treatment and adherence to Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines for anemia management.

Results

Three hundred sixty-eight (92.7%) patients attended at least one visit and 92 (23.2%) patients attended all four visits. Patients were mainly referred to a nephrologist for chronic renal failure (61.7%) or hypertension (42.8%). At baseline, 79.6% of patients had previous hospitalization and 79.1% were receiving antihypertensive medication. Serum creatinine and/or glomerular filtration rate was examined in >90% of patients, whereas parathyroid hormone was rarely examined (5.5%). Vitamin D supplementation was received by 6.5% of patients. The majority of patients were staged at 3 or 4 CKD (32% and 23.9%, respectively) and did not significantly change over time. The use of antithrombotic, antilipidemic and erythropoietin medication increased over the four surveys. The majority of patients (86.8%) achieved hemoglobin K/DOQI target levels.

Conclusion

These findings demonstrate a current lack of attention of CKD and related disorders (mineral metabolism, electrolyte balance, and anemia) at the level of the general practitioner (GP) and non-nephrology specialist, which can result in both delayed referral and inadequate treatment. By increasing both awareness of CKD and the coordinated relationship between GPs and nephrologists, patient clinical and therapeutic outcome may be improved.

The MAINTAIN study--managing hemoglobin variability with darbepoetin alfa in dialysis patients experiencing a severe drop in hemoglobin

BACKGROUND

Dialysis patients, receiving erythropoiesis stimulating agents, typically show signs of hemoglobin variability as a consequence of their dosing patterns, bleeding, infection, etc., which is commonly managed adjusting the dose regimen of the erythropoiesis stimulating agent. However, information on dosing strategies used in daily clinical practice and their outcomes in relation to hemoglobin variability is limited.

OBJECTIVES

To investigate clinical practice in Austria in relation with the management of hemoglobin variability, defined as a decrease of ³ 1 g/dL within 4 weeks from ³ 11 g/dL to £ 11 g/dL during maintenance therapy with darbepoetin alfa. The nature and incidence of clinical events related to the hemoglobin drop were also assessed.

RESEARCH DESIGN AND METHODS

The MAINTAIN non-interventional study was conducted in hemodialysis patients, receiving darbepoetin alfa in accordance to the label approved in the European Union at that time. Patient data were documented retrospectively for the 3 months prior to the hemoglobin drop. Data for the 6 months post hemoglobin drop were collected retrospectively or prospectively, depending on the time of patient inclusion respective to the Hb drop.

RESULTS

A hundred thirty six of 154 patients fulfilled all inclusion/exclusion criteria and had prospective documentation of 6 months. The main causes for the hemoglobin drop included surgical and medical procedures (36.1 %), and infections or infestations (24.4 %). The median treatment period was 273 days. The mean hemoglobin drop was - 1.74 g/dL (95 % confidence interval (CI): - 1.60 to - 1.87). Consequently, 81 % of the patients had their dose of darbepoetin alfa increased within a median Kaplan-Meier time to dose increase of 12.5 days (95 % CI: 6-22). The geometric mean weekly darbepoetin alfa dose increased by a factor of 1.1 from 29.1 mg (95 % CI: 24.6-34.4) in the 3 months before hemoglobin drop to 32.4 (95 % CI: 27.2-38.6) in months 4-6 post hemoglobin drop. Three patients had red blood cell transfusions before hemoglobin drop and nine patients after hemoglobin drop. The mean hemoglobin increase was 0.43 g/dL (95 % CI: 0.24-0.62) from immediately prior to 2 weeks after dose increase. The median Kaplan-Meier time to achieve a hemoglobin ³ 11 g/dL after hemoglobin drop was 36 days (95 % CI: 32-45). Frequent darbepoetin alfa dose adjustments were necessary to sustain maintenance levels. No drug-related adverse events were reported.

CONCLUSIONS

This observational study describes physicians' reactions to a drop in hemoglobin in clinical practice. Using darbepoetin alfa, the drop was generally compensated without leading to overcorrection.

Lack of adequate predialyis care and previous hemodialysis, but not hemoglobin variability, are independent predictors of anemia-associated mortality in incident Brazilian peritoneal dialysis patients: results from the BRAZPD study

BACKGROUND/AIMS

The objective of this study was to analyze the prevalence of anemia and variability of hemoglobin (Hb) values in peritoneal dialysis (PD) patients, to establish its associated factors and their impact on clinical outcomes in a large cohort of patients starting PD treatment.

METHODS

Data were collected monthly in incident patients, who were followed until the primary endpoint (death from all causes) or until leaving the study.

RESULTS

2,156 patients starting PD were included. The prevalence of Hb lower than 11 g/dl was 57% at baseline and decreased to 38% at the 4th month. Lack of adequate predialysis care and previous treatment with hemodialysis were the most important factors associated with anemia. Anemia was an independent predictor of mortality. There were no differences in patient survival throughout the different groups of Hb variability.

CONCLUSION

Our data point to the need of identifying other risk factors for anemia and aggressively interfere with the modifiable ones in order to correct anemia and decrease mortality in this group of high-risk patients.

C.E.R.A. maintains stable hemoglobin in Latin American patients on dialysis

Background

C.E.R.A. is a continuous erythropoietin receptor activator with characteristics that permit a once-monthly schedule of administration for the maintenance treatment for chronic kidney disease (CKD) patients. The main objective of this study was to assess the maintenance of Hb concentration with once-monthly intravenous and/or subcutaneous C.E.R.A. therapy in Latin American dialysis patients with chronic renal anemia previously treated with epoetin alfa s.c or i.v 1–3 times per week.

Methods

This was a single-arm, open-label, multicenter, 32-week study of anemic patients with CKD previously treated with epoetin alfa sc or iv 1–3 times per week. After a 4-week screening period, during which mean Hb levels were maintained between 10.5 and 12.5 g/dL on their previous erythropoiesis stimulating agent, eligible patients entered a 16-week C.E.R.A. dose titration period followed by a 4-week efficacy evaluation period (EEP) and a 28-week safety follow-up. The starting dose of C.E.R.A. was based on the previous dose of epoetin alfa. Doses of C.E.R.A. were then adjusted to maintain Hb levels within ±1.0 g/dL of the reference concentration and between 10.5 and 12.5 g/dL. The Hb reference concentration was defined as the mean of all Hb levels during screening. The primary end point was the proportion of patients maintaining a mean Hb concentration (g/dL) within ±1 g/dL of their reference Hb and between 10.5 and 12.5 g/dL during the EEP.

Results

A total of 163 patients from 27 centers in Argentina, Brazil, Chile, Colombia, Ecuador, Mexico, Peru, Uruguay, and Venezuela entered the treatment period and 102 completed the prescribed course of C.E.R.A. Forty-five patients (43.7 %) maintained a mean Hb concentration within ±1 g/dL of their reference Hb value and between 10.5 and 12.5 g/dL during the EEP. The median monthly dose remained constant at 120 μg during the titration period and during the EEP. On the average, there were only 2.3 dose changes per patient in 28 weeks of treatment, covering 7 C.E.R.A. scheduled administrations. 53 % of all dose changes were dose decreases, 47 % increases. A total of 10 AEs and 4 SAEs were considered to be related to the study treatment.

Conclusions

Once-monthly C.E.R.A. treatment effectively maintains stable Hb concentrations in patients with chronic renal anemia undergoing dialysis with a good safety and tolerability profile.

Monthly administration of a continuous erythropoietin receptor activator provides efficient haemoglobin control in non-dialysis patients during routine clinical practice: results from the non-interventional, single-cohort, multicentre, SUPRA study

BACKGROUND

The continuous erythropoietin receptor activator (C.E.R.A.) has a long half-life, a relatively low binding affinity for the erythropoiesis receptor and low systemic clearance. These characteristics permit once-monthly dosing, which could reduce staffing requirements and be advantageous for patients. However, outcomes observed during controlled trials of C.E.R.A. have not been assessed under everyday clinical conditions in which physicians make all therapeutic decisions based on their own experience, rather than according to a pre-defined protocol.

OBJECTIVE

This study aimed to assess whether the efficacy and safety of C.E.R.A. reported during controlled trials are reproducible under routine clinical conditions.

METHODS

This was a non-interventional, single-cohort, multicentre study carried out in 92 specialist nephrology clinics and private practices in Germany. The study included patients with non-dialysis chronic kidney disease and anaemia, with or without current erythropoiesis stimulating agent (ESA) therapy. C.E.R.A. initiation and dosing was at the discretion of the physician. The primary efficacy variable was the proportion of patients for whom all measured haemoglobin (Hb) values during months 7-9 were within the range 11-12 g/dL ('responders').

RESULTS

335 patients received ≥1 dose of C.E.R.A.; 150 had previously received ESA therapy. The mean number of doses was 7.6 per patient over a mean follow-up of 7.9 months. Mean ± SD Hb was 10.7 ± 1.1 g/dL at baseline and 11.3 ± 1.1 g/dL at the final visit (efficacy population, n = 205). The primary endpoint, all measured Hb values during months 7-9 within the range 11-12 g/dL, was achieved by 19.0% (39/205) of patients, increasing to 41.5% for Hb 11-13 g/dL, 42.0% for 10-12 g/dL and 76.6% for Hb ≥10 g/dL. Hb fluctuation during months 7-9 was ≤1 g/dL in 185/205 patients (90.2%). C.E.R.A. was well tolerated without novel safety concerns.

CONCLUSION

Hb levels remained stable during routine use of C.E.R.A. in an unselected population of non-dialysis chronic kidney disease patients with anaemia. C.E.R.A. was administered approximately monthly compared with 3-7 doses per month on previous ESA therapy.

Monthly continuous erythropoietin receptor activator treatment maintains stable hemoglobin levels in routine clinical management of hemodialysis patients

Once-monthly administration of CERA, a continuous erythropoietin receptor activator, has shown equivalent efficacy to shorter-acting erythropoiesis-stimulating agents (ESAs) that require more frequent dosing, but data on routine use of once-monthly CERA in hemodialysis patients are lacking. Study on Efficacy, Safety and Applicability of Mircera (SESAM) was a prospective, multicenter, noninterventional trial with a duration of up to 9 months (month 0-5 "titration phase"; month 6-8 "evaluation phase") to test the stability of Hb control in hemodialysis patients under routine conditions. Patient selection, Hb targets and CERA dosing were at the discretion of the local nephrologist. 918 patients from 92 German nephrology centers were included. Ninety-three percent were on ESA treatment prior to study entry. The mean number of CERA dose changes during the study was 1.9 ± 1.9 per patient. Mean Hb level was 11.4 ± 1.2 g/dL at baseline and 11.7 ± 1.4 g/dL at the end of the 8-month study. During the evaluation phase (months 6-8), 15.6%, 40.3%, and 66.0% of patients had stable Hb (i.e., at least two values) in the ranges 11-12, 10-12, and 10-13 g/dL, respectively. The mean intra-individual fluctuation in Hb was 1.4 ± 0.7 g/dL during the study (0.5 ± 0.4 g/dL during the 3-month evaluation phase). More than 90% of patients, and > 80% of physicians, rated CERA therapy as "very good" or "good" throughout the study. Four patients (0.4%) discontinued prematurely due to adverse drug reactions. Once-monthly CERA therapy maintains stable Hb values with low intra-individual variability and few dose adaptations in hemodialysis patients when administered entirely according to local practice, and the regimen was well-tolerated.

Greater variability in kidney function is associated with an increased risk of death

Intra-individual variability in kidney function is a common phenomenon; however, predictors of kidney function variability and its prognostic significance are not known. To examine this question, we assembled a cohort of 51,304 US veterans with an estimated glomerular filtration rate (eGFR) <60 ml/min at the end of the study period and who had at least two eGFR measurements during the previous 3 years. Variability in kidney function was defined for each patient as the coefficient of variation of the regression line fitted to all outpatient measures of eGFR during this time frame. In adjusted analyses, blacks, women, and those with Current Procedural Terminology and ICD-9-CM diagnostic codes for hypertension, diabetes, cardiovascular disease, peripheral artery disease, chronic lung disease, hepatitis C, dementia, acute kidney injury, and those with a greater number of hospitalizations had greater variability in eGFR. After a median follow-up of 4.9 years, there were 23.66%, 25.68%, and 31.23% deaths among patients in the lowest, intermediate, and highest tertiles of eGFR variability, respectively. Compared with the referent (those in the lowest tertile), patients in the highest tertile had a significantly increased risk of death with a hazard ratio of 1.34 (1.28-1.40), an association consistently present in all sensitivity analyses. Thus, our results demonstrate that greater variability in kidney function is independently associated with increased risk of death.

Impact of pharmacist-managed erythropoiesis-stimulating agents clinics for patients with non-dialysis-dependent CKD

BACKGROUND

Erythropoiesis-stimulating agents (ESAs) are associated with serious adverse events, and maintaining hemoglobin levels within a narrow range can be difficult. We examined the quality of ESA prescribing and monitoring in pharmacist-managed ESA clinics versus usual care in patients with non-dialysis-dependent chronic kidney disease (NDD-CKD).

STUDY DESIGN

Historical cohort.

SETTING & PARTICIPANTS

Outpatients receiving ESAs for NDD-CKD at 10 Veterans Affairs Medical Centers with both pharmacist-managed ESA clinics (n = 314) and physician-based care (ie, usual care; n = 91) and 6 sites with usual care only (n = 167) on January 1, 2009, were followed up for 6 months.

PREDICTOR

Type/site of care (ie, pharmacist-managed ESA clinic, usual care at ESA clinic site, usual-care site).

OUTCOMES

Primary outcomes were proportion of hemoglobin values in the target range of 10-12 g/dL, ESA dose, and frequency of hemoglobin monitoring. Factors associated with hemoglobin values out of target range were identified using multinomial logistic regression.

RESULTS

More hemoglobin values were in the target range in pharmacist-managed ESA clinics (71.1% vs 56.9% for usual-care sites; P < 0.001). The average 30-day dose of darbepoetin was 163 μg in pharmacist-managed ESA clinic patients versus 240 μg in usual-care site patients and 258 μg in usual-care patients at ESA clinic sites. For epoetin, corresponding average 30-day doses were 44,890 versus 47,141 and 57,436 IU. Veterans in pharmacist-managed ESA clinics had more hemoglobin measurements on average (5.8 vs 3.6 in usual-care sites and 3.8 in usual care at ESA clinic sites; P = 0.007). In the multinomial model, usual care was associated with hemoglobin levels out of target range, whereas heart failure and diabetes were associated with values in range.

LIMITATIONS

We could not assess whether different hemoglobin targets were used by usual-care providers.

CONCLUSIONS

Relative to usual care, pharmacist-managed clinics provided improved quality of ESA dosing and monitoring for patients with NDD-CKD.

Impact of higher hemoglobin targets on blood pressure and clinical outcomes: a secondary analysis of CHOIR

BACKGROUND

Targeting a higher hemoglobin in patients with chronic kidney disease leads to adverse cardiovascular outcomes, yet the reasons remain unclear. Herein, we sought to determine whether changes in erythropoiesis-stimulating agent (ESA) dose and in hemoglobin were predictive of changes in blood pressure (BP) and whether these changes were associated with cardiovascular outcomes.

METHODS

In this secondary analysis of 1421 Correction of Hemoglobin and Outcomes in Renal Disease (CHOIR) participants, mixed model analyses were used to describe monthly changes in ESA dose and hemoglobin with changes in diastolic BP (DBP) and systolic BP (SBP). Poisson modeling was performed to determine whether changes in hemoglobin and BP were associated with the composite end point of death or cardiovascular outcomes.

RESULTS

Monthly average DBP, but not SBP, was higher in participants in the higher hemoglobin arm. Increases in ESA doses and in hemoglobin were significantly associated with linear increases in DBP, but not consistently with increases in SBP. In models adjusted for demographics and comorbid conditions, increases in ESA dose (>0 U) and larger increases in hemoglobin (>1.0 g/dL/month) were associated with poorer outcomes [event rate ratio per 1000 U weekly dose per month increase 1.05, (1.02-1.08), P = 0.002 and event rate ratio 1.70 (1.02-2.85), P = 0.05, respectively]. However, increasing DBP was not associated with adverse outcomes [event rate ratio 1.01 (0.98-1.03), P = 0.7].

CONCLUSION

Among CHOIR participants, higher hemoglobin targets, increases in ESA dose and in hemoglobin were associated both with increases in DBP and with higher event rates; however, increasing DBP was not associated with adverse outcomes.

Treating anemia associated with chronic renal failure with erythropoiesis stimulators: recombinant human erythropoietin might be the best among the available choices

Chronic renal failure (CRF) is a widespread medical problem commonly accompanied by a hypoproliferative anemia ("renal anemia") due to erythropoietin deficiency. Anemia greatly contributes to reduced quality of life (Hr-QoL) and high morbidity and mortality in CRF patients. Recombinant human erythropoietin (rHu-Epo) was introduced to medical practice some 20years ago. It enables correction of anemia (hemoglobin levels, Hb) with dramatic immediate (Hr-QoL improvement) and long-term effects (reduced morbidity and mortality). Newer experimental data suggest that long-term benefits could be due not only to antianemic effect, but also to a direct organoprotective effect of (rHu)-Epo mediated through a receptor complex different from the "erythropoietic" erythropoietin receptor. During the last decade, two alternative treatments for renal anemia have been approved: darbepoetin and CERA. Both are direct agonists of the "erythropoietic" receptors and both were derived from rHu-Epo. Molecularly, they differ from rHu-Epo in that they are much larger molecules (darbepoetin is genetically modified rHu-Epo with a higher sugar content and CERA is pegylated rHu-Epo) with lower affinity for the erythropoietin receptor but with a longer circulating time. In terms of renal anemia correction, they are non-inferior to rHu-Epo and allow for less frequent dosing. They have never been compared to rHu-Epo regarding the long-term outcomes. It is hypothesized that regarding the long-term outcomes (morbidity, mortality), rHu-Epo might be superior to those larger molecules. The hypothesis is based on two types of observations. First, experimental data emphasize the role of small, erythropoietically less valuable rHu-Epo isoforms in its organoprotective effects. Second, clinical observations suggest that rHu-Epo enables for less variable Hb correction than the larger molecules, and pronounced within-subject Hb variability has been suggested as an independent predictor of poor long-term outcomes of renal anemia management.

Efficacy of hemopoietic-stimulating factors in patients undergoing chronic hemodialysis

Anemia has been linked to increased mortality and morbidity in renal hemodialysis patients. Other risk factors that contribute to an adverse outcome include the variability of hemoglobin (Hb) levels and the decreased response to erythropoiesis-stimulating factors (ESFs). In this study we evaluated the effectiveness of four different ESFs (epoetin-A, epoetin-B, darbepoetin, and CERA), assessed the variability of Hb levels, and compared ESF dosages which contributed to the achievement of Hb levels in each individual patient with renal failure undergoing chronic hemodialysis maintenance. In conclusion, the four ESFs administered are equally effective in the treatment of anemia in renal hemodialysis patients and they do not influence in a different manner the variability of Hb. The administration of darbepoetin-A and CERA might possibly cause more patients to overshoot the target level of Hb.

Simplifying anemia management in hemodialysis patients: ESAs administered at longer dosing intervals can enhance opportunities to provide patient-focused care

OBJECTIVE

To review issues and challenges in caring for hemodialysis patients with anemia of chronic kidney disease, specifically focusing on the effects of longer erythropoiesis-stimulating agent (ESA) dosing intervals on processes of care.

METHODS

PubMed searches were performed limited to the last 10 years to February 2011, focusing on articles in English that were 'clinical trials,' assessed processes of care, measured associations of hemoglobin (Hb) with outcomes, and explored/analyzed extended dosing intervals of ESAs in hemodialysis patients and recommendations for increasing the quality of care of these patients. Some limitations included the fact that a meta-analysis was not conducted; many studies were associative and therefore unable to prove causality; and none of the clinical trials directly compared the impact of more frequent or less frequent ESA dosing strategies on patient care and outcomes.

FINDINGS

Progress over the past several decades has been substantial; however, unmet needs remain and there is room for improvement in efficiencies of care. Many patients fail to meet Hb targets, and nephrology professionals' time is consumed with preparing, administering, and monitoring therapy. Direct interaction between patients and care providers has been lost as attention has shifted to 'cost-effective' (not necessarily patient-centered) ways to deliver care. Use of ESAs at longer dosage intervals represents one opportunity to improve efficiency of care. Newer ESAs have been developed for less frequent dosing. Once-monthly dosing decreases time spent administering/monitoring therapy and allows nephrology professionals to provide comprehensive renal care, wherein the patient rather than task-oriented processes becomes the primary focus.

CONCLUSIONS

A fragmented, uncoordinated care-delivery model heightens the urgency to systematically address issues related to delivery of care and improve efficiencies in anemia management as part of the patient-centered approach. ESAs designed for administration at longer intervals may effectively and reliably achieve Hb targets with once-monthly dosing, thereby decreasing time spent administering/monitoring therapy.

Anemia management with darbepoetin-alfa in outpatient hemodialysis patients switched from epoetin-alfa: a community hospital experience

Epoetin-alfa (EA) and darbepoetin-alfa (DA) are agents for treating anemia in dialysis patients. In September 2005, our free-standing outpatient hemodialysis center (community-hospital based) implemented an interchange from EA to DA. Since then, all hemodialysis patients receive DA as the preferred agent. We performed this observational study to compare effectiveness of DA with EA in anemia management in a cohort of hemodialysis outpatients. We studied 98 hemodialysis outpatients who received twice to thrice weekly EA from January to August 2005. These patients were switched to DA in September 2005, and baseline DA dose was calculated from the conversion table in the package insert. After a 4 month titration phase, the same cohort of patients, now on once weekly DA, was followed from January to September 2006. Dose of EA or DA was adjusted to maintain hemoglobin at 11 to 13 g/dL. Hematologic and dialysis parameters were collected on a monthly basis, and inpatient data were excluded. Mean ± standard deviation age was 65.8 ± 14.2 years, with 42 (42.9%) women. Mean ± standard deviation hemoglobin level was 12.5 ± 1.6 g/dL during EA and 12.5 ± 1.6 g/dL during DA therapy (P = 0.23). Proportion of patients achieving hemoglobin (11-13 g/dL) was 44.5% ± 28.9% with EA and 49.8% ± 25.8% with DA (P = 0.09). Average intrapatient absolute hemoglobin variability was 1.0 ± 0.5 g/dL on EA and 1.1 ± 0.5 g/dL on DA (P = 0.29). Median (and interquartile range) EA dose used was 11,400 (7,050-22,800) IU/week, and median DA dose was 59.8 (40-91.6) mcg/week with an EA:DA dose conversion ratio of 191:1. Patients on EA or DA had similar dialysis adequacy, albumin, and iron parameters. DA is as effective as EA in treating anemia in hemodialysis outpatients. Dose requirement of DA is greater than 200:1 of the amount of EA and may not translate into cost savings.

Facility-level interpatient hemoglobin variability in hemodialysis centers participating in the Dialysis Outcomes and Practice Patterns Study (DOPPS): Associations with mortality, patient characteristics, and facility practices

BACKGROUND

Hemodialysis patients with larger hemoglobin level fluctuations have higher mortality rates. We describe facility-level interpatient hemoglobin variability, its relation to patient mortality, and factors associated with facility-level hemoglobin variability or achieving hemoglobin levels of 10.5-12.0 g/dL. Facility-level hemoglobin variability may reflect within-patient hemoglobin variability and facility-level anemia-control practices.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Data from the Dialysis Outcomes and Practice Patterns Study (DOPPS; 26,510 hemodialysis patients, 930 facilities, 12 countries, 1996-2008) and from the Centers for Medicare & Medicaid Services (CMS; 193,291 hemodialysis patients, 3,741 US facilities, 2002).

PREDICTORS

Standard deviation (SD) in single-measurement hemoglobin levels in hemodialysis patients in facility cross-sections (facility-level hemoglobin SD); patient characteristics; facility practices.

OUTCOMES

Patient-level mortality; additionally, facility practices correlated with facility-level hemoglobin SD or patient hemoglobin levels of 10.5-12.0 g/dL.

RESULTS

Facility-level hemoglobin SD varied more than 5-fold across DOPPS facilities (range, 0.5-2.7 g/dL; mean, 1.3 g/dL) and by country (range, 1.1 in Japan-DOPPS [2005/2006] to 1.7 g/dL in Spain-DOPPS [1998/1999]), with substantial decreases seen in many countries from 1998 to 2007. Facility-level hemoglobin SD was related inversely to patient age, but was associated minimally with more than 30 other patient characteristics and facility mean hemoglobin levels. Several anemia management practices were associated strongly with facility-level hemoglobin SD and having a hemoglobin level of 10.5-12.0 g/dL. When examined in CMS data, facility-level hemoglobin SD was positively associated with within-patient hemoglobin SD during the prior 6 months. Patient mortality rates were higher with greater facility-level hemoglobin SD (DOPPS: HR, 1.08 per 0.5-g/dL greater facility-level hemoglobin SD [95% CI, 1.02-1.15; P = 0.006]; CMS: HR, 1.16 per 0.5-g/dL greater facility-level hemoglobin SD [95% CI, 1.11-1.21; P < 0. 001]).

LIMITATIONS

Residual confounding.

CONCLUSIONS

Facility-level hemoglobin SD was associated strongly and positively with patient mortality, not tightly linked to numerous patient characteristics, but related strongly to facility anemia management practices. Facility-level hemoglobin variability may be modifiable and its optimization may improve hemodialysis patient survival.

Hemoglobin variability and mortality: confounding by disease severity

BACKGROUND

Substantial variability in hemoglobin levels has been associated with increased mortality risk in hemodialysis patients. Variability also has been associated with concurrent comorbid conditions and hospitalization. Adequate adjustment for confounding by disease severity is needed to estimate the association of hemoglobin level variability with mortality risk.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Medicare hemodialysis patients in 3 groups: prevalent on July 1, 2006 (n = 133,246), prevalent on July 1, 1996 (n = 78,602), and incident between January 1, 2005, and June 30, 2006 (n = 24,999).

PREDICTOR

Hemoglobin level variability estimated using the residual deviation around the linear trend in hemoglobin levels during a 6-month entry period.

OUTCOME

Time to death.

MEASUREMENTS

We fit Cox models of 1-year mortality with and without adjustment for disease severity (comorbid conditions, hospitalization days, and months with hemoglobin level <10 g/dL), measured concurrently with hemoglobin level variability.

RESULTS

Disease severity was associated positively with hemoglobin level variability in all groups. Before adjustment for disease severity, HRs for hemoglobin level variability were 1.27 (95% CI, 1.24-1.31) per 1 g/dL for patients prevalent in 2006, 1.32 (95% CI, 1.27-1.38) for patients prevalent in 1996, and 1.08 (95% CI, 1.03-1.13) for patients incident in 2005-2006. After adjustment, HRs for hemoglobin level variability were 1.02 (95% CI, 0.99-1.05), 1.07 (95% CI, 1.03-1.12), and 1.01 (95% CI, 0.95-1.06), respectively.

LIMITATIONS

We did not adjust for time-varying confounding of hemoglobin level; an inclusion requirement introduces potential selection bias; our findings may not apply to incident hemodialysis patients younger than 65 years; assessment of comorbid conditions from claims is subject to misclassification, with possible residual confounding attributable to comorbid conditions; this observational study cannot prove causality.

CONCLUSIONS

After adjustment for concurrent disease severity, evidence supporting an association between hemoglobin level variability and mortality risk was weak and inconsistent. The clinical utility of hemoglobin level variability may be limited.

Development of an erythropoietin prescription simulator to improve abilities for the prescription of erythropoietin stimulating agents: is it feasible?

BACKGROUND

The increasing use of erythropoietins with long half-lives and the tendency to lengthen the administration interval to monthly injections call for raising awareness on the pharmacokinetics and risks of new erythropoietin stimulating agents (ESA). Their pharmacodynamic complexity and individual variability limit the possibility of attaining comprehensive clinical experience. In order to help physicians acquiring prescription abilities, we have built a prescription computer model to be used both as a simulator and education tool.

METHODS

The pharmacokinetic computer model was developed using Visual Basic on Excel and tested with 3 different ESA half-lives (24, 48 and 138 hours) and 2 administration intervals (weekly vs. monthly). Two groups of 25 nephrologists were exposed to the six randomised combinations of half-life and administration interval. They were asked to achieve and maintain, as precisely as possible, the haemoglobin target of 11-12 g/dL in a simulated naïve patient. Each simulation was repeated twice, with or without randomly generated bleeding episodes.

RESULTS

The simulation using an ESA with a half-life of 138 hours, administered monthly, compared to the other combinations of half-lives and administration intervals, showed an overshooting tendency (percentages of Hb values > 13 g/dL 15.8 ± 18.3 vs. 6.9 ± 12.2; P < 0.01), which was quickly corrected with experience. The prescription ability appeared to be optimal with a 24 hour half-life and weekly administration (ability score indexing values in the target 1.52 ± 0.70 vs. 1.24 ± 0.37; P < 0.05). The monthly prescription interval, as suggested in the literature, was accompanied by less therapeutic adjustments (4.9 ± 2.2 vs. 8.2 ± 4.9; P < 0.001); a direct correlation between haemoglobin variability and number of therapy modifications was found (P < 0.01).

CONCLUSIONS

Computer-based simulations can be a useful tool for improving ESA prescription abilities among nephrologists by raising awareness about the pharmacokinetic characteristics of the various ESAs and recognizing the factors that influence haemoglobin variability.

Individualizing anaemia therapy

Individualized strategies for managing renal anaemia with erythropoiesis-stimulating agents (ESAs) need to be advanced. Recent outcomes from clinical studies prompted a narrowing of the guideline-recommended haemoglobin target (11-12 g/dL) due to increased mortality and morbidity when targeting higher haemoglobin concentrations. Maintaining a narrow target is a clinical challenge, as haemoglobin concentration tends to fluctuate. The goal of individualized treatment is to achieve the haemoglobin target at the lowest ESA dose while avoiding significant fluctuations in haemoglobin concentrations and persistently low or high concentrations. This may require changes to the ESA dose and dosing frequency over the course of treatment.

Hemoglobin variability does not predict mortality in European hemodialysis patients

Patients with CKD exhibit significant within-patient hemoglobin (Hb) level variability, especially with the use of erythropoiesis stimulating agents (ESAs) and iron. Analyses of dialysis cohorts in the United States produced conflicting results regarding the association of Hb variability with patient outcomes. Here, we determined Hb variability in 5037 European hemodialysis (HD) patients treated over 2 years to identify predictors of high variability and to evaluate its association with all-cause and cardiovascular disease (CVD) mortality. We assessed Hb variability with various methods using SD, residual SD, time-in-target (11.0 to 12.5 g/dl), fluctuation across thresholds, and area under the curve (AUC). Hb variability was significantly greater among incident patients than prevalent patients. Compared with previously described cohorts in the United States, residual SD was similar but fluctuations above target were less frequent. Using logistic regression, age, body mass index, CVD history, dialysis vintage, serum albumin, Hb, angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) use, ESA use, dialysis access type, dialysis access change, and hospitalizations were significant predictors of high variability. Multivariable adjusted Cox regression showed that SD, residual SD, time-in-target, and AUC did not predict all-cause or CVD mortality during a median follow-up of 12.4 months (IQR: 7.7 to 17.4). However, patients with consistently low levels of Hb (<11 g/dl) and those who fluctuated between the target range and <11 g/dl had increased risks for death (RR 2.34; 95% CI: 1.24 to 4.41 and RR 1.74; 95% CI: 1.00 to 3.04, respectively). In conclusion, although Hb variability is common in European HD patients, it does not independently predict mortality.

Determining optimum hemoglobin sampling for anemia management from every-treatment data

BACKGROUND AND OBJECTIVES

Anemia management protocols in ESRD call for hemoglobin (Hb) monitoring every 2 to 4 weeks. Short-term Hb variability affects the reliability of Hb measurement and may lead to incorrect dosing of erythropoiesis stimulating agents. We prospectively analyzed short-term Hb variability and quantified the relationship between frequency of Hb monitoring and error in Hb estimation.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using the Crit-Line III TQA device, we prospectively observed Hb during each dialysis treatment in 49 ESRD patients and quantified long- and short-term Hb variability. We estimated Hb from data sampled at regular intervals; 8×, 4×, 2×, or 1× per month to establish how well we account for short-term variability at different monitoring intervals. We calculated the Hb estimation error (Hb(err)) as a root mean-squared difference between the observed and estimated Hb and compared it with the measurement error.

RESULTS

The most accurate Hb estimation is achieved when monitoring 8× per month (Hb(err) = 0.23 ± 0.05 g/dl), but it exceeds the accuracy of the measurement device. The estimation error increases to 0.34 ± 0.07 g/dl when monitoring 4× per month, 0.39 ± 0.08 g/dl when monitoring 2× a month, and 0.45 ± 0.09 g/dl when monitoring 1× per month. Estimation error comparable to instrument error information is as follows: 8× per month, 15 patients; 4× per month, 22 patients; 2× per month, 6 patients; 1× per a month, 6 patients.

CONCLUSIONS

Four times a month is the clinically optimal Hb monitoring frequency for anemia management.

Impact of haemoglobin and erythropoietin dose changes on mortality: a secondary analysis of results from a randomized anaemia management trial

BACKGROUND

Anaemia is a common complication of chronic kidney disease. A number of studies have identified an adverse association between haemoglobin (Hgb) variability and mortality. To date, no study has evaluated the impact of Hgb variability on mortality in the setting of a uniform Hgb target and erythropoiesis-stimulating agents (ESA) dosing strategy.

METHODS

One hundred and fifty-four haemodialysis (HD) patients from a previous randomized anaemia management study were followed up for up to 6 years. The impact of Hgb variability and ESA dosing parameters on subsequent mortality risk were evaluated.

RESULTS

More rapid rises in Hgb (Hgb deflect(pos)) and ESA dose increases were independently associated with mortality in multivariate analysis, whereas more rapid Hgb declines (Hgb deflect(neg)) and ESA dose decreases were not. Each gram per litre per week increase in Hgb deflect(pos) was associated with an adjusted hazard ratio (HR) of 1.23 (1.03-1.48), while for every 1000-unit increase in ESA dose, the adjusted HR was 1.12 (1.01-1.24). Factors associated with positive Hgb deflections included frequency and magnitude of ESA dose changes, baseline Hgb, patient weight and presence of an HD catheter.

CONCLUSIONS

Rapid Hgb rises and greater average Eprex dose increases were independently associated with a higher mortality risk in HD patients after adjustment for baseline Hgb and Eprex dose. A randomized controlled trial evaluating different ESA dosing strategies in response to individual patient ESA responsiveness is needed.

Association of ESA hypo-responsiveness and haemoglobin variability with mortality in haemodialysis patients

BACKGROUND

Anaemia is a common complication in dialysis patients. In most cases, it is treated with erythropoietin-stimulating agents (ESA). It is not entirely clear whether the variability of haemoglobin caused by changing ESA response is associated with increased mortality. Therefore, we conducted a retrospective cohort study to evaluate ESA responsiveness and haemoglobin variability in association with mortality.

METHODS

We used the Austrian dialysis and transplant registry, and identified 932 patients who were on maintenance haemodialysis in the years 2005-08 with recorded weekly ESA doses and haemoglobin concentrations. ESA response was defined as a positive regression slope over the observation period. Cox regression analysis with spline functions and purposeful variable selection algorithms were used.

RESULTS

Adjusted Cox regression analysis showed an increased mortality risk in subjects with wide ranges of haemoglobin variability (from <10 to >12 g/dL) (HR = 2.38, 95% CI 1.20-4.71, P = 0.013). Furthermore, patients that never reached haemoglobin levels >10 g/dL despite ESA therapy exhibited the highest risk of mortality (HR = 6.37, 95% CI 2.15-18.82, P < 0.001). ESA hypo-responsiveness was associated with increased risk of mortality in the low as well as high haemoglobin ranges [HR = 2.06, 95% CI 1.49-2.86 at haemoglobin of 9.5 g/dL and HR = 1.64, 95% CI 0.68-3.92 at 13.5 g/dL both vs. 11 g/dL (reference)]. ESA dose equivalents >16,000 units per week were associated with increased mortality in ESA responders (HR = 1.30, 95% CI 1.02-1.64). However, in hypo-responders, mortality is not associated with ESA dose (HR = 1.02, 95% CI 0.87-1.20) [both at weekly ESA dose of 20,000 units vs. 16,000 (reference)].

CONCLUSIONS

These findings suggest that the risk of mortality of haemodialysis patients requiring ESA therapy is lowest if the haemoglobin concentration is stably maintained in the range between 10 and 12 g/dL with weekly ESA dose equivalents <16,000 units.