Angiotensin-converting enzyme inhibitor as a risk factor for the development of anemia, and the impact of incident anemia on mortality in patients with left ventricular dysfunction

Erythropoiesis and Blood Pressure Are Regulated via AT1 Receptor by Distinctive Pathways

The renin–angiotensin system (RAS) plays a central role in blood pressure regulation. Although clinical and experimental studies have suggested that inhibition of RAS is associated with progression of anemia, little evidence is available to support this claim. Here we report that knockout mice that lack angiotensin II, including angiotensinogen and renin knockout mice, exhibit anemia. The anemia of angiotensinogen knockout mice was rescued by angiotensin II infusion, and rescue was completely blocked by simultaneous administration of AT1 receptor blocker. To genetically determine the responsible receptor subtype, we examined AT1a, AT1b, and AT2 knockout mice, but did not observe anemia in any of them. To investigate whether pharmacological AT1 receptor inhibition recapitulates the anemic phenotype, we administered AT1 receptor antagonist in hypotensive AT1a receptor knockout mice to inhibit the remaining AT1b receptor. In these animals, hematocrit levels barely decreased, but blood pressure further decreased to the level observed in angiotensinogen knockout mice. We then generated AT1a and AT1b double-knockout mice to completely ablate the AT1 receptors; the mice finally exhibited the anemic phenotype. These results provide clear evidence that although erythropoiesis and blood pressure are negatively controlled through the AT1 receptor inhibition in vivo, the pathways involved are complex and distinct, because erythropoiesis is more resistant to AT1 receptor inhibition than blood pressure control.

Is anemia a new cardiovascular risk factor?

Anemia is frequent in patients with cardiovascular disease and is often characterized as the fifth cardiovascular risk factor. It is considered to develop due to a complex interaction of iron deficiency, cytokine production and impaired renal function, although other factors, such as blood loss, may also contribute. Unfortunately, treatment of anemia in cardiovascular disease lacks clear targets and specific therapy is not defined. Treatment with erythropoietin-stimulating agents in combination with iron is the basic strategy but clear guidelines are not currently available. This review aims to clarify poorly investigated and defined issues concerning the relation of anemia and cardiovascular risk--in particular in patients with acute coronary syndromes and chronic heart failure--as well as the current therapeutic strategies in these clinical conditions.

Co-morbidities in heart failure

Heart failure is a clinical syndrome characterized by poor quality of life and high morbidity and mortality. Co-morbidities frequently accompany heart failure and further decrease in both quality of life and clinical outcome. We describe that the prevalence of co-morbidities in patients with heart failure is much higher compared to age-matched controls. We will specifically address the most studied organ-related co-morbidities, that is, renal dysfunction, cerebral dysfunction, anaemia, liver dysfunction, chronic obstructive pulmonary disease, diabetes mellitus and sleep apnoea. The pathophysiologic processes underlying the interaction between heart failure and co-morbid conditions are complex and remain largely unresolved. Although common risk factors are likely to contribute, it is reasonable to believe that factors associated with heart failure might cause other co-morbid conditions. Inflammation, neurohumoral pathway activation and hemodynamic changes are potential factors. We try to provide explanations for the observed association between co-morbidities and heart failure, as well as its impact on survival.

Iron deficiency anemia in heart failure

Anemia and iron deficiency are quite prevalent in patients with heart failure (HF) and may overlap. Both anemia and iron deficiency are associated with worse symptoms and adverse clinical outcomes. In the past few years, there has been an enormous interest in the subject of iron deficiency and its management in patients with HF. In this review, the etiology and relevance of iron deficiency, iron metabolism in the setting of HF, studies on iron supplementation in patients with HF and potential cardiovascular effects of subclinical iron overload are discussed.

Erythropoiesis stimulating agents (ESAs) for congestive heart failure: the red and the black

CHF is a disease of high incidence and prevalence in the elderly. Anemia is associated with an increased mortality in these patients. Erythropoietin secretion is reduced in these patients due to complexed mechanisms. Although some improvement in quality of life has been shown when using ESAs it has not been found any decrement on mortality. Moreover, safety reports suggest an increased risk of thromboembolic event. Together with the high drug cost, the use of ESAs cannot be recommended for the treatment of CHF patients.

Association between left ventricular dysfunction, anemia, and chronic renal failure. Analysis of the Heart Failure Prevalence and Predictors in Turkey (HAPPY) cohort

BACKGROUND

Anemia and chronic renal failure (CRF) are frequent comorbidities in patients with heart failure (HF), and they have been reported to be associated with increased mortality and hospitalization rates. HF, anemia, and CRF have been reported to interact with each other forming a vicious cycle termed cardio-renal-anemia syndrome. The aim of the present study was to evaluate the association of HF, anemia, and CRF using data from the large-scale"Heart Failure Prevalence and Predictors in Turkey (HAPPY)" study.

PATIENTS AND METHODS

Among the HAPPY cohort, 3,369 subjects who had either left ventricular dysfunction (LVD) or normal left ventricular function on echocardiography or normal serum NT-proBNP levels were included in this analysis.

RESULTS

The prevalence of anemia and CRF was significantly higher in patients with LVD compared with subjects with normal ventricular function (20.7 % vs. 4.0 % and 19.0 % vs. 3.7 %, respectively; p < 0.001 for each). Binary logistic regression analyses for the presence of LVD, anemia, and CRF demonstrated that each one was an independent predictor for the presence of the others.

CONCLUSION

These findings point to the presence of cardio-renal-anemia syndrome and the necessity of treating these comorbidities in patients with HF.

Effect of angiotensin converting enzyme inhibitors and angiotensin receptor blockers on hemoglobin levels

Background

Angiotensin converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are widely used in the management of congestive heart failure (CHF), diabetes mellitus (DM) and hypertension (HTN). Use of these agents is reported to cause anemia.

Methods

We examined the association between standard care use of ACEI or ARB and subsequent change in hemoglobin (Hgb) in a population of 701 adult primary care patients with DM, CHF and/or HTN. Data analysis was conducted to adjust for baseline differences between the treatment groups.

Results

After adjusting for differences in covariates at baseline between the subjects who were prescribed ACEI (N = 519) and ARB (N = 182), as well as the associated odds of being prescribed ARB, the ACEIs were associated with lower mean Hgb [0.18 (0.02, 0.34) g/dL, p = 0.02] at follow up relative to ARBs. However, patients with CHF experienced an increase in Hgb while on treatment (0.42 g/dL), especially those treated with ACEIs (0.56 g/dL). Chronic kidney disease at baseline was not associated with a significant decrease in Hgb in either treatment group.

Conclusions

Since ACEIs and ARBs are most frequently used in patients who are vulnerable to complications from anemia, such as patients with CHF, HTN and DM, these findings may be useful to clinicians in selecting medications and monitoring patients for the adverse effects of treatment.

Association of anaemia in primary care patients with chronic kidney disease: cross sectional study of quality improvement in chronic kidney disease (QICKD) trial data

BACKGROUND

Anaemia is a known risk factor for cardiovascular disease and treating anaemia in chronic kidney disease (CKD) may improve outcomes. However, little is known about the scope to improve primary care management of anaemia in CKD.

METHODS

An observational study (N = 1,099,292) with a nationally representative sample using anonymised routine primary care data from 127 Quality Improvement in CKD trial practices (ISRCTN5631023731). We explored variables associated with anaemia in CKD: eGFR, haemoglobin (Hb), mean corpuscular volume (MCV), iron status, cardiovascular comorbidities, and use of therapy which associated with gastrointestinal bleeding, oral iron and deprivation score. We developed a linear regression model to identify variables amenable to improved primary care management.

RESULTS

The prevalence of Stage 3-5 CKD was 6.76%. Hb was lower in CKD (13.2 g/dl) than without (13.7 g/dl). 22.2% of people with CKD had World Health Organization defined anaemia; 8.6% had Hb ≤ 11 g/dl; 3% Hb ≤ 10 g/dl; and 1% Hb ≤ 9 g/dl. Normocytic anaemia was present in 80.5% with Hb ≤ 11; 72.7% with Hb ≤ 10 g/dl; and 67.6% with Hb ≤ 9 g/dl; microcytic anaemia in 13.4% with Hb ≤ 11 g/dl; 20.8% with Hb ≤ 10 g/dl; and 24.9% where Hb ≤ 9 g/dl. 82.7% of people with microcytic and 58.8% with normocytic anaemia (Hb ≤ 11 g/dl) had a low ferritin (<100 ug/mL). Hypertension (67.2% vs. 54%) and diabetes (30.7% vs. 15.4%) were more prevalent in CKD and anaemia; 61% had been prescribed aspirin; 73% non-steroidal anti-inflammatory drugs (NSAIDs); 14.1% warfarin 12.4% clopidogrel; and 53.1% aspirin and NSAID. 56.3% of people with CKD and anaemia had been prescribed oral iron. The main limitations of the study are that routine data are inevitably incomplete and definitions of anaemia have not been standardised.

CONCLUSIONS

Medication review is needed in people with CKD and anaemia prior to considering erythropoietin or parenteral iron. Iron stores may be depleted in over >60% of people with normocytic anaemia. Prescribing oral iron has not corrected anaemia.

Statins for renal patients: a fiddler on the roof?

Atherosclerotic cardiovascular disease is the main cause of morbidity and mortality in chronic kidney disease patients. There is a raft of evidence showing that in the general population dyslipidaemia is associated with an increased risk of cardiovascular events, as well as with a greater prevalence of chronic kidney disease. Consequently, the use of statins in the general population with dyslipidaemia is not controversial. Nevertheless, the benefits of statins in patients with chronic kidney disease are more elusive. The authors review the possible effects of statins on the progression of renal disease and cardiovascular events in chronic kidney disease patients.

Introduction of angiotensin-converting enzyme inhibitors induces a fall in hemoglobin levels in elderly patients hospitalized with heart failure: a cohort study

BACKGROUND AND AIMS

Although the use of angiotensin-converting enzyme-inhibitors (ACE-I) is a cornerstone of treatment for heart failure (HF), these agents have been associated with decreasing hemoglobin levels in several settings. The aim of this study was to assess whether ACE-I are associated with decreasing hemoglobin in older subjects, and whether this effect is enhanced among patients with HF.

METHODS

The association between starting use of ACE-I and variations in hemoglobin levels was investigated in 10,354 hospitalized elderly, 1217 of whom had a verified diagnosis of HF, enrolled in a multicenter pharmacoepidemiology survey.

RESULTS

According to Cox regression analysis, the relative risk of a decrease in hemoglobin levels >0.5 g/dL associated with starting treatment with ACE-I was 1.12 (95% CI 0.98-1.26, p=0.081) among participants without HF, and 1.98 (95% CI 1.54-2.53, p<0.0001) among patients with HF, after adjusting for potential confounders. Analysis of the interaction term in Cox regression confirmed that the association between use of ACE-I and hemoglobin decrease varied according to diagnosis of HF (p=0.003) and older age (p=0.029).

CONCLUSIONS

Starting treatment with ACE-I is independently associated with increased risk of hemoglobin decrease among older hospitalized patients with HF. Hemoglobin levels should be monitored in older subjects who start ACE-I.

Effect of anemia on short- and long-term outcome in patients hospitalized for acute coronary syndromes

Anemia is common in hospitalized cardiac patients and is associated with adverse outcomes. The aim of this study was to identify the association of anemia with early and long-term outcomes in patients with acute coronary syndromes (ACSs). Included were 5,304 consecutive patients (73% men, 61 ± 12 years of age) admitted to a coronary care unit from 1985 through 2008 for ACS. According to the World Health Organization, anemia was defined as serum hemoglobin levels <13 g/dl for men and <12 g/dl for women. Anemia was divided into tertiles to compare mild, moderate, and severe anemia to nonanemia. For trend analyses the study population was categorized in 3 groups: 1985 to 1990, 1991 to 2000, and 2001 to 2008. Outcome measurements were all-cause mortality at 30-days and 20 years. Anemia was present in 2,016 patients (38%), of whom 655 had mild anemia, 717 moderate anemia, and 646 severe anemia. Median follow-up duration was 10 years (range 2 to 25). Compared to nonanemia, adjusted hazard ratios (HRs) for mortality at 30 days were 1.40 for moderate anemia (95% confidence interval [CI] 1.04 to 1.87) and 1.67 for severe anemia (95% CI 1.25 to 2.24). At 20 years HRs were 1.13 for moderate anemia (95% CI 1.01 to 1.27) and 1.39 for severe anemia (95% CI 1.23 to 1.56). In addition, survival during hospitalization improved over time. Compared to 1985 to 1990 adjusted HRs were 0.52 for 1991 to 2000 (95% CI 0.41 to 0.66) and 0.36 for 2001 to 2008 (95% CI 0.25 to 0.51). In conclusion, presence and severity of anemia is an important predictor of higher in-hospital and long-term mortality after ACS. In addition, since the 1980s in-hospital outcome of patients with ACS and anemia has improved.

Anaemia and the development of depressive symptoms following acute coronary syndrome: longitudinal clinical observational study

OBJECTIVE

Depressive symptoms are common following acute coronary syndrome (ACS) and predict subsequent cardiovascular morbidity. Depression in acute cardiac patients appears to be independent of clinical disease severity and other cardiovascular measures. One factor that has not been considered previously is anaemia, which is associated with fatigue and adverse cardiac outcomes. This study assessed the relationship between anaemia on admission and depressive symptoms following ACS.

DESIGN

Longitudinal clinical observational study.

SETTING

Coronary care unit.

PATIENTS

223 patients with documented ACS.

MAIN OUTCOME MEASURES

Depressive symptoms measured with the Beck Depression Inventory 3 weeks after admission.

RESULTS

Anaemia was defined with WHO criteria and was present in 30 (13.5%) patients. Anaemia predicted raised depression scores 3 weeks later independently of age, gender, marital status, educational attainment, smoking, Global Registry of Acute Cardiac Events (GRACE) risk scores, negative mood in hospital and history of depression (p=0.003). The odds of a Beck Depression Inventory score ≥10 among anaemic patients were 4.03 (95% CIs 1.48 to 11.00), adjusted for covariates. Sensitivity analyses indicated that effects were also present when haemoglobin was analysed as a continuous measure. Anaemia also predicted major adverse cardiac events over the subsequent 12 months.

CONCLUSIONS

Anaemia appears to contribute to depression following ACS and is associated with future cardiac morbidity. Studies evaluating the effects of anaemia management will help delineate the role of this pathway more precisely.

Treatment with iron of patients with heart failure with and without anemia

Iron deficiency is a common cause of anemia in otherwise healthy individuals and plays an important role in the development of anemia within the heart failure patient population. Iron-deficient heart failure patients experience worse symptoms and are less exercise tolerant than those without iron deficiency. These symptoms may occur even before clinical anemia is evident. This article reviews studies of the benefits of the use of intravenous iron to treat iron deficiency in anemic and nonanemic heart failure patients and an overview of the physiology and pathophysiology of iron metabolism in chronic heart failure.

Treatment of anemia in heart failure: potential risks and benefits of intravenous iron therapy in cardiovascular disease

Iron-deficiency anemia is common in patients with heart failure (HF), but the optimum diagnostic tests to detect iron deficiency and the treatment options to replete iron have not been fully characterized. Recent studies in patients with HF indicate that intravenous iron can rapidly replenish iron stores in patients having iron-deficiency anemia, with resultant increased hemoglobin levels and improved functional capacity. Preliminary data from a subgroup analysis also suggest that supplemental intravenous iron therapy can improve functional capacity even in those subjects without anemia. The mechanisms responsible for this observation are not fully characterized, but may be related to beneficial effects of iron supplementation on mitochondrial respiration in skeletal muscle. The long-term safety of using intravenous iron supplementation in HF populations is not known. Iron is a known pro-oxidant factor that can inhibit nitric oxide signaling and irreversibly injury cells. Increased iron stores are associated with vascular endothelial dysfunction and increased risk of coronary heart disease events. Additional clinical trials are needed to more fully characterize the therapeutic potential and safety of intravenous iron in HF patients.

Outcomes associated with anemia in patients with heart failure

Over the past decade, a growing body of literature has led to a greater understanding of the relationship between anemia and the outcomes in patients with heart failure. This article reviews the current literature on the association between anemia and a broad range of clinical outcomes, including mortality, hospitalization, health status, and cost.

Narrative review: the management of acute decompensated heart failure

Acute decompensated heart failure (ADHF) is the most common reason for hospitalization in Western nations. The prognosis of patients admitted to hospital with ADHF is poor, with up to 64% being readmitted within the first 90 days after discharge and with a 1-year mortality approximating 20%. Epidemiological studies suggest that the majority of patients hospitalized with ADHF receive treatment that is inadequate and which is not based on scientific evidence. Furthermore, emerging data suggest that the "conventional" therapeutic interventions for ADHF including morphine, high-dose diuretics, and inotropic agents may be harmful. The goal of this review is to provide evidence-based recommendations for the diagnosis and management of ADHF.

Pharmacological treatment of chronic systolic heart failure: are we scraping the bottom of the barrel?

Heart failure is a major health problem and its prevalence is growing, primarily as a consequence of the aging of the population. Recently, we have witnessed significant progress in reducing the mortality associated with chronic heart failure due to the introduction of renin-angiotensin-aldosterone system inhibitors, beta-blocking agents and the use of electrical devices. However, the prognosis of heart failure is still so disappointing that it remains the leading cause of death in developed countries. This grim record impels the search for new therapeutic strategies. The objective of this paper is to briefly review the results of some recent trials that have been put in place to test the effects of drugs that are deemed to be potentially capable of improving the prognosis of chronic systolic heart failure patients. Despite compelling theoretical premises, the results to date appear to be weak or even disappointing.

The role of statins in chronic kidney disease

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality not only amongst the general population, but also in patients with chronic kidney disease (CKD). Persons with CKD are much more likely to die of CVD than to experience kidney failure. Clinical trials have demonstrated that statins are gaining widespread acceptance as a principal therapy for the primary and secondary prevention of atherosclerosis and CVD. In CKD patients the role of statins in primary prevention of CVD remains to be clarified. The absolute benefit of treatment with a statin seems to be greater among nondialysis-dependent-CKD patients. Studies in end-stage renal disease patients on dialysis did not confirm these results. Recently, however, the Study of Heart and Renal Protection (SHARP) has suggested that statins with ezetimibe may be beneficial even in dialysis patients. Clinical studies with statins on proteinuria reduction and renal disease progression have yielded conflicting results. Some studies have shown a prominent reduction in proteinuria, while other studies have shown that statins had no effect or may cause proteinuria at high doses. This review examines the clinical evidence of the observed benefits of kidney function with the use of this drug category in CKD patients.

Anemia in heart failure: an overview of current concepts

Chronic heart failure is a substantial public health problem. Anemia is an important comorbidity frequently observed in patients with the disease and, in heart failure, anemia has only recently started to attract systematic epidemiological and therapeutical research endeavor. This article describes the many aspects of anemia in chronic heart failure, starting with the ongoing discussion of how to define anemia, which has important consequences for the estimation of its prevalence and incidence. Further, we discuss prognostic implications of anemia in patients with chronic or acute heart failure, the etiology of anemia in heart failure and treatment possibilities. Such therapeutic avenues embrace intravenous iron preparations and subcutaneous administration of erythropoietin and its derivatives, all of which have been extensively studied over the last several years. Finally, this article describes the potential costs incurred by treating anemic patients with heart failure.

Erythropoiesis-stimulating agents and heart failure

Anemia is a common comorbidity in heart failure (HF) patients. Its occurrence and severity are associated with worse prognosis. Although the etiology of anemia is multifactorial, inappropriate erythropoietin (EPO) production and/or bone-marrow resistance to EPO appear crucial in majority of anemic HF patients. Consequently, treatment based on this pathophysiological background may prove to be most effective and beneficial. In a number of smaller clinical studies, administration of erythropoiesis-stimulating agents (ESAs) to anemic HF patients improved a number of surrogate endpoints, including left ventricular function, exercise capacity, renal function, and different quality of life parameters. However, two larger, phase II studies, did not fully confirm these promising results. Furthermore, many concerns have been raised on the safety of ESAs after the recent publication of studies correcting anemia in patients with chronic kidney disease (CKD). On the other hand, chronic HF population varies significantly from CKD patients, with different comorbidities, renal function, and etiology of anemia. Moreover, ESAs have been shown to possess robust nonhematopoietic effects in the heart, namely inhibition of apoptosis and stimulation of neovascularization. Therefore, large-scale trials with ESAs are required to examine the effect and safety of anemia treatment in HF patients.

The cardio-renal-anaemia syndrome predicts survival in peritoneally dialyzed patients

INTRODUCTION

Anaemia is one of the arms of the cardio-renal-anaemia syndrome (CRA) in chronic kidney disease (CKD) patients. The correction of anaemia was effective in the amelioration of both cardiac and renal failure. We studied the relationship between the severity of CRA syndrome in peritoneally dialyzed patients and their survival probability.

MATERIAL AND METHODS

Fifty-six patients on peritoneal dialysis were followed for 1 year. Definition of the severity of the CRA in dialysis patients: cardiac arm - NYHA class I-IV = 1-4 points, renal arm - non-diabetic patients age < 65 =1 point, non-diabetic patients age>65 = 2 points, diabetic patients age < 65 = 3 points, diabetic patients age>65 = 4 points, anaemia arm - Hb 11-13 g/dl (male), 11-12 g/dl (female) = 1 point, Hb 10-11 g/dl = 2 points, Hb 9-10 g/dl = 3 points, Hb < 9 g/dl = 4 points. The severity score = cardiac + renal + anaemia arms score divided by 3 (maximum 4 points).

RESULTS

A total of 10/56 patients (18%) died during the study. The median value for the severity score of the whole group was 1.69. In Kaplan-Meier analysis CRA severity score was strongly associated with mortality (p < 0.001). It also correlated with albumin, CRP, erythropoietin treatment, Hb and fasting glucose. In the multivariate regression analysis age, Hb, albumin, and presence of diabetes remained significant predictors of death.

CONCLUSIONS

The severity score of CRA syndrome in peritoneally dialyzed patients is an independent and very significant predictor of death. The patients with a high severity score had more hypoalbuminaemia, higher inflammation markers and higher prevalence of diabetes and chronic heart failure. Cardio-renal-anaemia syndrome severity scoring as defined by us could be an easy tool to predict outcome of dialysis patients.

The role of the renin-angiotensin system in the regulation of erythropoiesis

The renin-angiotensin system is the major regulator of blood pressure by virtue of controlling vascular resistance and plasma volume. Much less recognition exists for the role of the renin-angiotensin system in regulating erythropoiesis, a biological function critical for oxygen delivery to tissues. In this review, we present evidence that angiotensin II (Ang II) is a physiologically important regulator of erythropoiesis with 2 key actions. First, Ang II is a growth factor of erythroid progenitors and, in cooperation with erythropoietin, increases red blood cell mass. Second, Ang II acts as an erythropoietin secretagogue to maintain increased erythropoietin levels despite increments in hematocrit. Among a multitude of physiologic and pathophysiologic implications, these lines of evidence provide an explanation for the effect of angiotensin-converting enzyme inhibitors and Ang II type 1 receptor blockers to decrease hematocrit or cause anemia in various clinical conditions.

Anemia in chronic heart failure

Anemia is frequently observed in patients with chronic heart failure and is increasingly recognized as an important and treatable condition. The present review will summarize the current knowledge of the prevalence, causative factors, and pathophysiologic correlates of anemia in chronic heart failure. Despite increasing knowledge of anemia there are very few evidence-based recommendations for treatment. Potential benefits of therapy with supplemental hematinics such as iron, subcutaneous erythropoiesis-stimulating agents, or both will also be discussed.

Effect of anemia and comorbidity on functional status and mortality in old age: results from the Leiden 85-plus Study

BACKGROUND

There is limited insight into the attributable effect of anemia and comorbidity on functional status and mortality in old age.

METHODS

The Leiden 85-plus Study is a population-based prospective follow-up study of 562 people aged 85 years. Anemia was defined according to World Health Organization criteria. We measured 3 parameters of functional status at baseline and annually thereafter for 5 years: disability in basic and instrumental activities of daily living, cognitive function and the presence of depressive symptoms. We obtained mortality data from the municipal registry.

RESULTS

The prevalence of anemia at baseline was 26.7% (150/562). Participants who had anemia at baseline had more disability in activities of daily living, worse cognitive function and more depressive symptoms than participants without anemia at baseline (p <or= 0.01). These differences disappeared after adjustment for comorbidity. After adjustment for comorbidity in the prospective analyses, anemia at baseline was associated with an additional increase in disability in instrumental activities of daily living during follow-up; incident anemia during follow-up (n = 99) was associated with an additional increase in disability in basic activities of daily living. Prevalent and incident anemia were both associated with an increased risk of death, even after we adjusted for sex, education level, income, residence in a long-term care facility, C-reactive protein level, creatinine clearance and the presence of disease (hazard ratio for prevalent anemia 1.41, 95% confidence interval [CI] 1.13 to 1.76; hazard ratio for incident anemia 2.08, 95% CI 1.60 to 2.70).

INTERPRETATION

Anemia in very elderly people appears to be associated with an increased risk of death, independent of comorbidity. However, the associated functional decline appears to be attributed mainly to comorbidity.

Prospective assessment of the occurrence of anemia in patients with heart failure: results from the Study of Anemia in a Heart Failure Population (STAMINA-HFP) Registry

BACKGROUND

Although a potentially important pathophysiologic factor in heart failure, the prevalence and predictors of anemia have not been well studied in unselected patients with heart failure.

METHODS

The Study of Anemia in a Heart Failure Population (STAMINA-HFP) Registry prospectively studied the prevalence of anemia and the relationship of hemoglobin to health-related quality of life and outcomes among patients with heart failure. A random selection algorithm was used to reduce bias during enrollment of patients seen in specialty clinics or clinics of community cardiologists with experience in heart failure. In this initial report, data on prevalence and correlates of anemia were analyzed in 1,076 of the 1,082 registry patients who had clinical characteristics and hemoglobin determined by finger-stick at baseline.

RESULTS

Overall (n = 1,082), the registry patients were 41% female and 73% white with a mean age (+/-SD) of 64 +/- 14 years (68 +/- 13 years in community and 57 +/- 14 years in specialty sites, P < .001). Among the 1,076 patients in the prevalence analysis, mean hemoglobin was 13.3 +/- 2.1 g/dL (median 13.2 g/dL); and anemia (defined by World Health Organization criteria) was present in 34%. Age identified patients at risk for anemia, with 40% of patients >70 years affected.

CONCLUSIONS

Initial results from the STAMINA-HFP Registry suggest that anemia is a common comorbidity in unselected outpatients with heart failure. Given the strong association of anemia with adverse outcomes in heart failure, this study supports further investigation concerning the importance of anemia as a therapeutic target in this condition.

Prevalence of anemia in heart failure and its effects on prognosis

Anemia is common in heart failure patients but its prevalence varies widely according to various sources. There is no agreement regarding the definition of anemia to be used and several risk factors have been found to be associated with higher prevalence of anemia in heart failure patients. The prevalence of anemia depends on its definition and the clinical characteristics of the patients included in the studies. Anemia is associated with adverse prognosis in the general population, in patients with end-stage renal disease, chronic diseases, coronary artery disease and also in patients with heart failure; however, despite all the information available, the issue of whether anemia is an independent predictor of mortality and the nature of the risk between anemia and mortality in heart failure patients are not yet fully understood.

Erythropoietic stress and anemia in diabetes mellitus

Anemia is one of the world's most common preventable conditions, yet it is often overlooked, especially in people with diabetes mellitus. Diabetes-related chronic hyperglycemia can lead to a hypoxic environment in the renal interstitium, which results in impaired production of erythropoietin by the peritubular fibroblasts and subsequent anemia. Anemia in patients with diabetes mellitus might contribute to the pathogenesis and progression of cardiovascular disease and aggravate diabetic nephropathy and retinopathy. Anemia occurs earlier in patients with diabetic renal disease than in nondiabetic individuals with chronic kidney disease. Although erythropoietin has been used to treat renal anemia for nearly two decades, debate persists over the optimal target hemoglobin level. Most guidelines recommend that hemoglobin levels be maintained between 105g/l and 125g/l. The suggested role of anemia correction--to prevent the progression of left ventricular hypertrophy in patients with diabetes mellitus--is yet to be established. However, an emphasis on regular screening for anemia, alongside that for other diabetes-related complications, might help to delay the progression of vascular complications in these patients.

Hemoglobin variability in anemia of chronic kidney disease

Hemoglobin levels in individuals with chronic kidney disease fluctuate frequently above or below the recommended target levels within short periods of time even though the calculated mean hemoglobin remains within the target range of 11 to 12 g/dl. Both pharmacologic features and dosing of erythropoiesis-stimulating agents may lead to cyclic pattern of hemoglobin levels within the recommended range. Several longitudinal studies highlight the complexity of maintaining stable hemoglobin levels over time. As a consequence, patients may risk increased hospitalization and mortality, because both low and high hemoglobin levels are associated with increased cardiovascular events and death. The duration of time that hemoglobin remains higher or lower than the target thresholds may be important to adverse outcomes. It is not clear whether adverse effects of hemoglobin variability are because of the therapy with erythropoiesis-stimulating agents and/or iron or despite such a therapy. Several factors affect hemoglobin variability, including those that are drug related, such as pharmacokinetic parameters, patient-related differences in demographic characteristics, and factors affecting clinical status, as well as clinical practice guidelines, treatment protocols, and reimbursement policies. Strategies that consider each of these factors and reduce hemoglobin variability may be associated with improved clinical outcomes.

The potential role of erythropoietin in chronic heart failure: from the correction of anemia to improved perfusion and reduced apoptosis?

Besides stimulating erythropoiesis, erythropoietin (EPO) exerts powerful proangiogenic and antiapoptotic effects. These erythropoiesis-independent effects are potentially useful as a supplement for the treatment of chronic heart failure (CHF). EPO may improve microvascular capacity of ischemic myocardial tissue and could thereby (partially) restore myocardial function. In addition, EPO could protect cardiomyocytes from hypoxic damage and prevent them from apoptosis. However, the clinical value of these erythropoiesis-independent effects for the treatment of CHF remains to be elucidated. Small-sized trials evaluating the effects of EPO treatment on surrogate endpoints in patients with CHF showed positive effects in general; however, their mutual results are not always unambiguous. Moreover, increasing hematocrit levels with EPO has been associated with increased blood viscosity and an inherent risk of thromboembolic events. A currently running multicenter phase III trial is designed to provide clarity concerning the effects of EPO on outcome and safety in patients with CHF. Focusing primarily on outcome, however, does not provide insight into the mode of action and isolated benefits of the erythropoiesis-independent effects of EPO. Further exploration of these effects is a key issue to gain knowledge of the full potential of EPO for the treatment of CHF.

Anemia and chronic heart failure implications and treatment options

Anemia is a common comorbidity in patients with heart failure and is associated with worse long-term outcomes. Although the cause of anemia in heart failure is unclear, the weight of evidence suggests that renal dysfunction, along with neurohormonal and proinflammatory cytokine activation in heart failure, favors the development of anemia of chronic disease, with defective iron utilization, inappropriate erythropoietin production, and depressed bone marrow function. Similarly, the mechanisms by which anemia worsens heart failure outcomes are unknown but may be related to increased myocardial workload. If anemia is a mediator and not just a marker of poor outcomes, correcting anemia could become an important and novel therapeutic target to improve long-term outcomes in such patients. Indeed, several small-sized studies have shown the beneficial effects of empirically treating anemia in heart failure patients with recombinant erythropoietin and intravenous iron. However, the ideal threshold at which therapy should be initiated and the extent of correction considered safe and desirable in the individual patient with heart failure need to be known. These issues become more important because of increasing safety concerns that recombinant erythropoietin therapy for treating anemia may be associated with adverse cardiovascular outcomes in patients with chronic kidney disease and may worsen cancer in patients receiving chemotherapy to treat various types of cancer. Therefore, further prospectively designed studies are required to address some of these questions. Fortunately, 2 large mortality morbidity trials, TREAT (Trial to Reduce Cardiovascular Events with Aranesp Therapy) in patients with chronic kidney disease and RED-HF (Reduction of Events with Darbepoetin alfa in Heart Failure) in heart failure patients, are in progress and are likely to provide definitive answers.

Anemia and cardio-renal syndrome: A deadly association?

Despite growing recognition of the frequent presentation of cardio-renal syndrome, its underlying pathophysiology is not well understood, and no consensus as to its appropriate management has been achieved. On the other hand, there is growing evidence that the presence of anemia can worsen cardiac function and symtomps in patients with congestive heart failure (CHF) and that correction of anemia may beneficial. We believe that the treatment modalities, especially eryhtropoietin, to correct anemia will be an important part of our therapeutic armemanterium in the battle against CHF.