Anemia and chronic kidney disease are associated with poor outcomes in heart failure patients

Development of a model predicting cardiac events in heart failure patients with decreased renal function: a retrospective study

BACKGROUND

Inappropriate and multiple medications affect the prognosis of patients with acute decompensated heart failure (ADHF). However, in ADHF patients with decreased renal function, there have been no reports on prognostic factors, including medication data, or models for predicting cardiac events.

AIM

To develop a model including medication data to predict cardiac events in ADHF patients with decreased renal function.

METHOD

This retrospective cohort study included 443 first-time admitted ADHF patients with decreased renal function (estimated glomerular filtration rate < 60 mL/min/1.73 m² at discharge) in the Showa University Fujigaoka Hospital. The primary outcome was cardiac events within one year after discharge, defined as the composite of HF readmission, HF mortality, and cardiovascular mortality. The model for predicting cardiac events was developed using predictive factors extracted by multivariable analysis. The cardiac events curves were visualized using the Kaplan-Meier method and estimated using a log-rank test.

RESULTS

The incidence of cardiac events within one year after discharge was 20.1%. By multivariable analysis, we observed that atrial fibrillation, weight loss < 5%, brain natriuretic peptide ≥ 200 pg/mL, polypharmacy, and beta-blockers use below target dosage were significantly associated with an increased risk of cardiac events. The developed model, the cardiac events rate in the high-risk group was significantly higher than in the low-risk group (41.0 vs. 9.2%, p < 0.001).

CONCLUSION

The developed model for predicting cardiac events will be useful in decision-making to support appropriate early management of ADHF patients with decreased renal function.

Role of Iron Deficiency in Heart Failure-Clinical and Treatment Approach: An Overview

BACKGROUND

The association of chronic heart failure (CHF) and iron deficiency (ID) with or without anemia is frequently encountered in current medical practice and has a negative prognostic impact, worsening patients' exercise capacity and increasing hospitalization costs. Moreover, anemia is common in patients with chronic kidney disease (CKD) and CHF, an association known as cardio-renal anemia syndrome (CRAS) possessing a significantly increased risk of death.

AIM

This review aims to provide an illustrative survey on the impact of ID in CHF patients-based on physiopathological traits, clinical features, and the correlation between functional and absolute ID with CHF-and the benefit of iron supplementation in CHF.

METHOD

We selected the most recent publications with important scientific content covering the association of CHF and ID with or without anemia.

DISCUSSIONS

An intricate physiopathological interplay is described in these patients-decrease in erythropoietin levels, activation of the renin-angiotensin-aldosterone system, systemic inflammation, and increases in hepcidin levels. These mechanisms amplify anemia, CHF, and CKD severity and worsen patients' outcomes.

CONCLUSIONS

Anemia is frequently encountered in CHF and represents a negative prognostic factor. Data from randomized controlled trials have underlined the administration of intravenous iron therapy (ferric carboxymaltose) as the only viable treatment option, with beneficial effects on quality of life and exercise capacity in patients with ID and systolic heart failure.

Testosterone and quality of life in patients with dilated cardiomyopathy

BACKGROUND

Testosterone is an important factor that influences the quality of life in men. The purpose of this study is to evaluate how testosterone level impacts the quality of life in patients with dilated cardiomyopathy.

METHODS

This cross-sectional single-center included 97 male patients with dilated cardiomyopathy, in whom serum testosterone was measured. Health-related quality of life was measured using the translated validated version of the Kansas City Cardiomyopathy Questionnaire (KCCQ-12). We used correlation and multivariable regression to assess the association between KCCQ-12 score, serum testosterone level, and clinical and paraclinical variables.

RESULTS

The mean age of study participants was 58 (range 29-88). The mean LVEF was 25 ±8.61%. The average total serum testosterone level was 3.13 ±2.72 (range 0.19-13.5 ng/ml). The median global KCCQ-12 score was 44.8 (6.2-90.6) representing a poor to fair impairment in quality of life. There was an inverse correlation between the KCCQ-12 score and NYHA class (Pearson coefficient r = 0.847 p<0.001) and a direct correlation with LVEF (r=0.445, p<0.001). Also, the KCCQ-12 score correlated with hemoglobin level (r=0.214, p=0.037) and plasmatic creatinine level (r=-0.296 p= 0.004). In multivariable regression, the independent predictors of health-related quality of life were testosterone, LVEF, and NYHA class.

CONCLUSIONS

The results of this study showed for the first time a significant direct relationship between serum testosterone levels and quality of life in patients with dilated cardiomyopathy.

Effect of iron supplementation in patients with heart failure and iron deficiency: A systematic review and meta-analysis

Background

The effectiveness of oral and intravenous iron supplementation in reducing the risk of mortality and hospitalizations in HF patients with iron deficiency is not well-established.

Methods

A thorough literature search was conducted across 2 electronic databases (Medline and Cochrane Central) from inception through March 2021. RCTs assessing the impact of iron supplementation on clinical outcomes in iron deficient HF patients were considered for inclusion. Primary end-points included all-cause mortality and HF hospitalization. Evaluations were reported as odds ratios (ORs) or risk ratios (RRs) with 95% confidence intervals (CI) and analysis was performed using a random effects model. I² index was used to assess heterogeneity.

Results

From the 2599 articles retrieved from initial search, 10 potentially relevant studies (n = 2187 patients) were included in the final analysis. Both oral (OR: 0.93; 95% CI: 0.08-11.30; p = 0.951) and intravenous (OR: 0.97; 95% CI: 0.73-1.29; p = 0.840) iron supplementation did not significantly reduce all-cause mortality. However, intravenous iron supplementation significantly decreased the rates of overall (OR: 0.52; 95% CI: 0.33-0.81; p = 0.004) and HF (OR: 0.42; 95% CI: 0.22-0.80; p = 0.009) hospitalizations. In addition, intravenous ferric carboxymaltose therapy significantly reduced the time to first HF hospitalization or cardiovascular mortality (RR = 0.70; 95% CI = 0.50-1.00; p = 0.048), but had no effect on time to first cardiovascular death (RR: 0.94; 95% CI: 0.70-1.25; p = 0.655).

Conclusion

Oral or intravenous iron supplementation did not reduce mortality in iron deficient HF patients. However, intravenous iron supplementation was associated with a significant decrease in overall and HF hospitalizations.

Association of anaemia and all-cause mortality in patients with ischaemic heart failure varies by renal function status

Aims

The aims of the current study were to evaluate the association between anaemia and all‐cause mortality according to chronic kidney disease (CKD) status and to explore at what level of haemoglobin concentration would the all‐cause mortality risk increase prominently among CKD and non‐CKD patients, respectively.

Methods and results

This is a prospective cohort study, and 1559 patients with ischaemic heart failure (IHF) were included (mean age of 63.5 ± 11.0 years, 85.8% men) from December 2015 to June 2019. Patients were divided into the CKD (n = 481) and non‐CKD (n = 1078) groups based on the estimated glomerular filtration rate of 60 mL/min/1.73 m². In the CKD group, the incidence rate of all‐cause mortality in anaemic and non‐anaemic patients was 15.4 per 100 person‐years and 10.8 per 100 person‐years, respectively, with an incidence rate ratio of 1.42 (95% confidence interval: 1.00–2.02; P‐value = 0.05). In the non‐CKD group, the incidence rate of all‐cause mortality in anaemic and non‐anaemic patients was 9.8 per 100 person‐years and 5.5 per 100 person‐years, respectively, with an incidence rate ratio of 1.78 (95% confidence interval: 1.20–2.59; P‐value = 0.005). After a median follow‐up of 2.1 years, the cumulative incidence rate of all‐cause mortality in anaemic and non‐anaemic patients was 41.5% and 44.1% (P‐value = 0.05) in the CKD group, and 30.9% and 18.1% (P‐value < 0.0001) in the non‐CKD group. In the CKD group, cumulative incidence rate of all‐cause mortality increased prominently when haemoglobin concentration was below 100 g/L, which was not observed in the non‐CKD group.

Conclusions

Results of the current study indicated that among IHF patients, the association between anaemia and all‐cause mortality differed by the renal function status. These findings underline the importance to assess mortality risk and manage anaemia among IHF patients according to the renal function status.

Relation between Hemoconcentration Status and Readmission Plus Mortality Rate Among Iranian Individuals with Decompensated Heart Failure

BACKGROUND

Hemoconcentration (HC) has been suggested to be a useful biomarker for determination of optimum diuretic therapy in acute heart failure (HF), but role of this factor in rehospitalization and death was still controversial. In this study, we aimed to define relation between HC and readmission and mortality rate among Iranian patients with acute HF.

METHODS

This was a prospective cohort study done from March 2017 to March 2018 using data of a HF section of Persian Registry Of cardioVascular diseasE. From a total number of 390 registered HF individuals aged 18 years or older, 69 ones showed alterations in hemoglobin (Hb) levels. Hb levels were measured at admission and discharge time. HC was defined as any increased level in Hb during hospitalization. The relation of HC with readmission and death rate was done using multiple logistic regression and Cox proportional hazard model, respectively.

RESULTS

The mean age of study population was 70.5 ± 11.9 years with the dominant percentage of male participants (66.9%). Patients showing HC during admission did not reveal any significant decreased likelihood of rehospitalization compared to negative ones. In comparison to HC negative patients, those showing increments in Hb levels had a borderline significant lower likelihood of mortality (hazard ratio: 0.82, 95% confidence interval, CI = 0.07-1.18, P = 0.08).

CONCLUSIONS

Our data suggested that HC was associated marginally with reduced mortality rate 6 months post HF attack and could be utilized as a useful biomarker for risk stratification of HF patients. Several prospective longitudinal population-based studies are necessary proving these associations.

Red Cell Distribution Width and Severe Left Ventricular Dysfunction in Ischemic Heart Failure

OBJECTIVE

The red cell distribution width (RDW), a simple and widely available marker, has been linked with an increased risk of adverse outcomes in patients with heart failure (HF) and risk of death, and cardiovascular events in those with previous myocardial infarction, but its relation with the severity of left ventricular (LV) dysfunction is not fully investigated. The aim of this study was to assess the prognostic value of the RDW in post myocardial infarction patients with typical signs and symptoms of HF and with reduced LV ejection fraction (EF).

METHODS

Patients (n = 350) came from an ongoing registry of consecutive patients who admitted for ischemic heart disease at our center. All patients were followed up 1 year after the initial hospitalization by telephone interviews. The outcomes studied were mortality and hospitalization because of decompensated HF.

RESULTS

RDW-coefficient of variation (express in percentage) was calculated from SD of mean corpuscular volume and mean corpuscular volume itself. Using logistic regression analysis, 3 variables consisting age, RDW level, and hemoglobin were identified as independent predictors of severe LV dysfunction (LVEF <30%). Levels of RDW were associated with the presence of severe LV dysfunction, with an accuracy of 61.4% (95% confidence interval: 56.2%-66.4%) and 66.9% (95% confidence interval: 61.8%-71.6%), using cut-off values of higher than 13.5 and 13.8, respectively.

CONCLUSION

Our results suggest that elevated RDW may be used as a prognostic tool among HF patients with the documented myocardial infarction because it is an inexpensive, rapidly calculated test that is already routinely in use in practice.

Severity of Anemia Predicts Hospital Length of Stay but Not Readmission in Patients with Chronic Kidney Disease: A Retrospective Cohort Study

The aim of this study was to examine the relationship of severe anemia to hospital readmission and length of stay (LOS) in patients with chronic kidney disease (CKD) stage 3-5. Compared with the general population, patients with moderate CKD have a higher hospital readmission rate and LOS. Anemia in patients with moderate CKD is associated with higher morbidity and mortality. The influence of anemia on hospital outcomes in patients with moderate CKD has not been characterized.We conducted a retrospective cohort study at Maine Medical Center, a 606-bed academic tertiary care hospital. Patients with CKD stages 3-5 and not on dialysis admitted during February 2013 to January 2014 were eligible. Patients with end stage renal disease on hemodialysis or peritoneal dialysis, kidney transplant, acute kidney injury, gastrointestinal bleeding, active malignancy, pregnancy, and surgery were excluded. The cohort was split into severe anemia (hemoglobin ≤9  g/dL) versus a comparison group (hemoglobin >9 g /dL), and examined for differences in 30-day hospital readmission and LOS.In this study, the data of 1141 patients were included, out of which 156 (13.7%) had severe anemia (mean hemoglobin 8.1 g/dL, SD 0.8). Severe anemia was associated with increased hospital LOS (mean 6.4 (SD 6.0) days vs mean 4.5 (SD 4.0) days, P < 0.001). The difference was 1.7 day longer (95% CI 0.94, 2.45). There was no difference in readmission rate (mean 11.5% vs 10.2%, P = 0.7).Patients with moderate CKD and severe anemia are at risk for increased hospital LOS. Interventions targeting this high-risk population, including outpatient management of anemia, may benefit patient care and save costs through improved hospital outcomes.

Clinical outcomes of erythropoietin use in heart failure patients with anemia of chronic kidney disease

BACKGROUND

Anemia and chronic kidney disease are common disorders in heart failure (HF) patients and are associated with increased morbidity and mortality. This study assessed clinical outcomes associated with erythropoietin (EPO) treatment in this cardiorenal anemia syndrome (CRAS) population.

METHODS AND RESULTS

This was a retrospective cohort study of Veterans Affairs patients with CRAS from January 2003 to December 2006. The primary outcome was a composite of death, acute coronary syndrome (ACS), HF, and stroke. Multiple Cox regression modeling was used to evaluate the outcome in patients prescribed (n = 213) and not prescribed EPO (n = 1845). Adjusted incidence of mortality was statistically significantly higher in EPO than in non-EPO users (33.8% vs 19.7%; hazard ratio 1.40, 95% confidence interval 1.06-1.85; P = .02). The unadjusted composite of cardiovascular events/death was higher in the EPO group, but not statistically significant when adjusted for confounders (P = .12). Crude ACS events were documented in 18.8% and 10.8% patients (P = .001), and stroke events occurred in 22.5% and 18.3% patients (P = .14) in EPO and non-EPO groups, respectively.

CONCLUSIONS

We found that in CRAS patients, EPO use was associated with increased risk of mortality and a trend toward increased cardiovascular events. Therefore, clinicians considering EPO use in CRAS patients should assess whether any potential benefits outweigh the risks of use.

Anemia, heart failure and evidence-based clinical management

Anemia is a prevalent comorbidity and marker of a poorer prognosis in patients with heart failure (HF). Its clinical relevance, as well as its pathophysiology and the clinical management of these patients are important subjects in the specialized literature. In the present review, we describe the current concepts on the pathophysiology of anemia in HF, its diagnostic criteria, and the recommendations for iron supplementation. Also, we make a critical analysis of the major studies showing evidences on the benefits of this supplementation. The four main components of anemia are addressed: chronic disease, dilutional, "renal" and malabsorption. In patients with HF, the diagnostic criteria are the same as those used in the general population: serum ferritin levels lower than 30 mcg/L in patients without kidney diseases and lower than 100 mcg/L or serum ferritin levels between 100-299 mcg/L with transferring saturation lower than 20% in patients with chronic kidney diseases. Finally, the therapeutic possibilities for anemia in this specific patient population are discussed.

Anemia is Associated With Mortality Following Endovascular Repair of Abdominal Aortic Aneurysm

Aim: The aim of this study was to compare midterm mortality between anemic and nonanemic patients undergoing endovascular repair of abdominal aortic aneurysm and to assess a correlation with markers of inflammation. Methods: Anemia was defined as hemoglobin <13 (men) and <12 g/dL (women). The impact of anemia and inflammatory markers on mortality was assessed using Kaplan-Meier curves and Cox regression. Results: A total of 224 patients (12 females [5.36%]; age: 69.73 ± 8.72 years) were included; 102 (45.53%) were anemic. Median follow-up was 17 months (interquartile range: 7-25 months). Nine patients died (1.79%; 8 anemic vs 1 nonanemic). Survival was lower for patients with anemia (log-rank, P = .01). White blood cell count and C-reactive protein (CRP) differed significantly ( P < .001 and P = .01). Anemia and CRP were associated with decreased survival (Cox regression, P = .01, hazard ratio [HR]: 0.35, 95% confidence interval: 0.14-0.84 and P = .002, HR: 1.18, 95% CI: 1.06-1.31). Conclusion: Patients with anemia had decreased survival over the midterm; inflammatory markers were higher among this group.

Anemia in heart failure patients

Heart failure is a very common disease, with severe morbidity and mortality, and a frequent reason of hospitalization. Anemia and a concurrent renal impairment are two major risk factors contributing to the severity of the outcome and consist of the cardio renal anemia syndrome. Anemia in heart failure is complex and multifactorial. Hemodilution, absolute or functional iron deficiency, activation of the inflammatory cascade, and impaired erythropoietin production and activity are some pathophysiological mechanisms involved in anemia of the heart failure. Furthermore other concomitant causes of anemia, such as myelodysplastic syndrome and chemotherapy, may worsen the outcome. Based on the pathophysiology of cardiac anemia, there are several therapeutic options that may improve hemoglobin levels, tissues' oxygenation, and probably the outcome. These include administration of iron, erythropoiesis-stimulating agents, and blood transfusions but still the evidence provided for their use remains limited.

Analysis of early kidney damage in hospitalized patients with chronic kidney disease: a multicenter study

BACKGROUND

To identify the risk factors for early kidney damage in hospitalized Chinese patients with chronic kidney disease (CKD).

METHODS

A total of 12 multicenter cross-sectional studies were conducted between January 2005 and January 2006 in Chinese CKD patients with estimated glomerular filtration rate (eGFR) equal to or more than 30 mL/min/1.73 m2 in Shanghai. CKD was defined according to the K/DOQI guideline. GFR was estimated by the simplified modification of diet in renal disease equation. The demographic, clinical, and laboratory data were collected through a questionnaire and analyzed among eligible patients stratified by three different CKD groups (CKD stages 1, 2, and 3). The relevant clinical and laboratory risk factors for early kidney damage with a GFR < 90 mL/min/1.73 m2 were determined by logistic regression.

RESULTS

A total of 822 CKD patients were enrolled in this study. There were significant differences in age and gender among patients with CKD stages 1, 2, and 3. The prevalence of hypertension, cardiovascular disease, cerebral vascular disease, anemia, and hyperuricemia increases when the eGFR declines. Logistic analysis showed that age, hypertension, anemia, and hyperuricemia were independently associated with early kidney damage.

CONCLUSIONS

In CKD patients, we have identified only age, hypertension, anemia, and hyperuricemia as the risk factors for early kidney damage. Risk factors should be managed to prevent accelerated kidney damage in CKD patients.

Characteristics and outcomes among heart failure patients with anemia and renal insufficiency with and without blood transfusions (public discharge data from California 2000-2006)

Renal insufficiency and anemia are increasingly recognized as predictors of adverse events in heart failure. The impact of blood transfusion on mortality in patients with heart failure has not been previously characterized. We examined temporal changes in admissions and in-hospital mortality using public discharge data from California (2000 to 2006) and then evaluated the impact of renal insufficiency, anemia, and transfusion on in-hospital mortality in univariate and multivariate analyses. In total 596,456 unique patient admissions for heart failure were recorded. Renal insufficiency and anemia were common co-morbidities (27.4% and 27.1%, respectively) and 6.2% of patients received a transfusion of red blood cells. Renal insufficiency and anemia were associated with increased mortality (unadjusted odds ratio [OR] 2.45, 95% confidence interval [CI] 2.39 to 2.52, and 1.27, 95% CI 1.24 to 1.30, respectively). After adjustment, renal insufficiency (OR 2.54, 95% CI 2.46 to 2.62) and anemia (OR 1.12 95% CI 1.07 to 1.17) remained significant; however, transfusion emerged as the strongest single predictor (OR 3.81, 95% CI 3.51 to 4.13) of mortality. In conclusion, these data suggest that anemia and renal insufficiency are independently associated with mortality in an unselected heart failure population. This is the first study to demonstrate that transfusion magnifies this effect and is associated with a particularly poor prognosis.

Anemia and chronic kidney disease are potential risk factors for mortality in stroke patients: a historic cohort study

Background

Chronic kidney disease (CKD) is associated to a higher stroke risk. Anemia is a common consequence of CKD, and is also a possible risk factor for cerebrovascular diseases. The purpose of this study was to examine if anemia and CKD are independent risk factors for mortality after stroke.

Methods

This historic cohort study was based on a stroke registry and included patients treated for a first clinical stroke in the stroke unit of one academic hospital over a three-year period. Mortality predictors comprised demographic characteristics, CKD, glomerular filtration rate (GFR), anemia and other stroke risk factors. GFR was estimated by means of the simplified Modification of Diet in Renal Disease formula. Renal function was assessed according to the Kidney Disease Outcomes Quality Initiative (K/DOQI)-CKD classification in five groups. A value of hemoglobin < 120 g/L in women and < 130 g/L in men on admission defined anemia. Kaplan-Meier survival curves and Cox models were used to describe and analyze one-year survival.

Results

Among 890 adult stroke patients, the mean (Standard Deviation) calculated GFR was 64.3 (17.8) ml/min/1.73 m² and 17% had anemia. Eighty-two (10%) patients died during the first year after discharge. Among those, 50 (61%) had K/DOQI CKD stages 3 to 5 and 32 (39%) stages 1 or 2 (p < 0.001). Anemia was associated with an increased risk of death one year after discharge (p < 0.001). After adjustment for other factors, a higher hemoglobin level was independently associated with decreased mortality one year after discharge [hazard ratio (95% CI) 0.98 (0.97-1.00)].

Conclusions

Both CKD and anemia are frequent among stroke patients and are potential risk factors for decreased one-year survival. The inclusion of patients with a first-ever clinical stroke only and the determination of anemia based on one single measure, on admission, constitute limitations to the external validity. We should investigate if an early detection and management of both CKD and anemia could improve survival in stroke patients.

The effect of erythropoietin on exercise capacity, left ventricular remodeling, pressure-volume relationships, and quality of life in older patients with anemia and heart failure with preserved ejection fraction

A prospective, open-label, 3-month study was conducted to evaluate the feasibility and short-term clinical effect of subcutaneous erythropoietin injections in patients with anemia and heart failure with preserved ejection fraction (ejection fraction, 55%+/-2%). Using a dose-adjusted algorithm to effect a rate of rise in hemoglobin not to exceed 0.4 g/dL /wk, hemoglobin (10.8+/-0.3 to 12.2+/-0.3 g/dL) and red blood cell volume (1187+/-55 to 1333+/-38 mL) increased with an average weekly dose of 3926 units. Functional measures increased from baseline (6-minute walk test [289+/-24 to 331+/-22 m], exercise time [432+/-62 to 571+/-51 s], and peak oxygen consumption [8.2+/-0.7 to 9.4+/-0.9 mL/kg/min], all P<.05). End-diastolic volume declined significantly (8% volumetric decrease, 108+/-3 to 100+/-3 mL, P =.03), but there were no significant changes in left ventricular mass or estimated left ventricular end-diastolic pressure. Pressure-volume analysis demonstrated a reduction in ventricular capacitance at an end-diastolic pressure of 30 mm Hg without significant changes in contractile state.

Should a statin be prescribed to every patient with heart failure?

Chronic heart failure (HF) represents an emerging epidemic since its prevalence is continuously increasing despite advances in treatment. Many recent clinical studies have clearly demonstrated that statin therapy is associated with improved outcomes in HF irrespective of aetiology (ischaemic or not) or baseline cholesterol levels. Indeed, most of the conducted large statin trials and trials in HF have demonstrated a positive effect of statins in HF patients. Furthermore, the use of statins in HF seems to be safe as none of the recent trials has resulted in worse outcomes for HF patients treated with statins. Potential mechanisms through which statins could benefit the failing myocardium include non-sterol effects of statins, as well as effects on nitric oxide and endothelial function, inflammation and adhesion molecules, apoptosis and myocardial remodelling and neurohormonal activation. This review discusses the pathophysiological basis of statin effects on HF and focuses on clinical data for the benefit from statin use in this setting. Until today there are no official recommendations in both the American and the European guidelines regarding the use of statins in HF patients, as the available data come from small observational or larger but retrospective, non-randomised studies. Therefore, HF patients should be treated according to current lipid guidelines. Large randomised clinical trials are underway and will further delineate the role of statin therapy in HF patients. Until more data are available, we could not recommend statin use to every patient with HF irrespective of HF aetiology and baseline cholesterol levels.

Congestive heart failure-related anemia and a role for erythropoietin

Congestive heart failure (CHF) is a common clinical problem, especially affecting the elderly. Current strategies of neurohormonal blockade with medications like angiotensin converting enzyme inhibitors have improved morbidity and mortality, but further improvement in outcomes requires new strategies. Both anemia and chronic renal disease commonly accompany congestive heart failure; their close relationship, in which one disease exacerbates the other, has been termed the cardio-renal-anemia syndrome. Correction of anemia in CHF patients using recombinant erythropoietin is feasible; small studies suggest that anemic congestive heart failure patients may have improved morbidity with this therapy. Recent animal and human studies of erythropoietin have shown that its benefit may be derived from both hematological and newly discovered non-hematological properties. Anemia might soon be considered a modifiable risk factor for optimal CHF management.

Renal dysfunction in heart failure patients: what is the evidence?

Congestive heart failure (CHF) is an increasingly common medical condition and the fastest growing cardiovascular diagnosis in North America. Over one-third of patients with heart failure also have renal insufficiency. It has been shown that renal insufficiency confers worsened outcomes to patients with heart failure. However, a majority of the larger and therapy-defining heart failure medication and device trials exclude patients with advanced renal dysfunction. These studies also infrequently perform subgroup analyses based on the degree of renal dysfunction. The lack of information on heart failure patients who have renal insufficiency likely contributes to their being prescribed mortality and morbidity reducing medications and receiving diagnostic and therapeutic procedures at lower rates than heart failure patients with normal renal function. Inclusion of patients with renal insufficiency in heart failure studies and published guidelines for medication, device, and interventional therapies would likely improve patient outcomes.

The relative dosing of epoetin alfa and darbepoetin alfa in chronic kidney disease

OBJECTIVE

The purpose of this study was to review and analyze current research to evaluate the dose ratio of epoetin alfa and darbepoetin alfa for the treatment of anemia in chronic kidney disease (CKD) and to identify determinants of the variation in epoetin alfa:darbepoetin alfa dose ratios across studies.

METHODS

A systematic review of the literature for comparative switch and non-switch studies of epoetin alfa and darbepoetin alfa treatments in CKD for the period 2000-2005 was performed. Two reviewers independently assessed the quality of the information. Data on the study design and outcomes were collected for each selected study. The dose ratio from epoetin alfa to darbepoetin alfa was calculated for each study, and the results were reported stratified by study characteristics. To control for differences in study design and characteristics that could explain the variability in the relative dosages of the two agents across studies, multivariate regression analysis was conducted. Based on these results, a dose conversion ratio for Canada was estimated.

RESULTS

A total of 21 studies involving 16 378 patients exposed to epoetin alfa or darbepoetin alfa in CKD were identified. Univariate analysis of the dose ratios indicated a mean dose ratio of 217:1 (IU of epoetin alfa:mug of darbepoetin alfa). Results from the multivariate analysis demonstrated that the study design (i.e., switch study versus straight comparison studies) and geographical coverage (i.e., United States) affected the results. Based on the multivariate analysis, the dose conversion ratio between epoetin alfa and darbepoetin alfa for Canada was 169:1.

CONCLUSIONS

Despite limitations associated with switching studies and the limited total number of studies available, this systematic review based on aggregated results provides further evidence to the clinical community that the dose conversion ratio for epoetin alfa:darbepoetin alfa in CKD patients in Canada is approximately 169:1. At that ratio, treatment with epoetin alfa is 11-18% cheaper than treatment with darbepoetin alfa in Canada.