Correction of iron deficiency in the cardiorenal syndrome.

Impaired energy metabolism is a feature of Congestive Heart Failure (CHF). Iron deficiency has been shown to reduce energy production in the cell in animals and humans. Iron deficiency is common in both Chronic Kidney Disease (CKD) and in CHF. Recent studies suggest that iron deficiency is an independent risk factor for mortality in CHF. Studies of correction of the anemia with intravenous (IV) iron in both CKD and CHF have shown an improvement in the anemia and, in some cases, in the renal function as well. Some CHF studies of correction of the iron deficiency have shown an improvement in cardiac function and structure as well as in exercise capacity and quality of life. This occurred independent of whether or not they had anemia, suggesting that the iron deficiency itself may be independently contributing to the worsening of the CHF and CKD. If future long-term studies confirm the safety and efficacy of IV iron in the treatment of iron deficiency in CKD and CHF, this will become a new addition to the therapeutic armamentarium of the cardiorenal syndrome, and parameters of iron deficiency will become part of the routine measurements performed in both CKD and CHF whether or not the patient is anemic.

The emerging role of NO and IGF-1 in early renal hypertrophy in STZ-induced diabetic rats.

BACKGROUND: Diabetic nephropathy (DN) is a major complication of diabetes mellitus, and the most common cause of end-stage renal disease. DN is characterized by early hyperfiltration and renal hypertrophy, which are associated with increased renal insulin-like growth factor-1 (IGF-1) levels. The relationship between IGF-1 and nitric oxide (NO) in DN is not established. The aim of this study was to investigate the effects of NO system modulation on the IGF-1-mediated hypertrophy and hyperfiltration during the first week after diabetes induction. METHODS: Diabetes was induced in rats by streptozotocin (STZ) injection. Diabetic rats were treated with NO synthase inhibitor L-NG-nitroarginine methyl ester (L-NAME). Various serum IGF-binding proteins (IGFBPs) and renal IGFBP1 expression was evaluated. Urine and plasma NO(2) + NO(3) level analysis was also performed. RESULTS: STZ induced hyperglycaemia decreased plasma insulin levels and brought about a decrease in body weight. L-NAME administration to diabetic rats significantly prevented renal hypertrophy and hyperfiltration. Serum IGFBP3, IGFBP4 and 30-kDa IGFBP fraction were all significantly reduced in diabetic rats, compared with those in non-diabetic control rats. However, the renal IGFBP1 mRNA expression in diabetic rats was significantly higher. These changes were accompanied by an increased in NO production. L-NAME administration prevented the serum IGFBP decline, without significantly affecting the renal IGFBP1 mRNA expression. CONCLUSIONS: We have shown that increased renal IGF-1 and increased NO production during the very early stages of STZ-induced DN are associated with renal hypertrophy and hyperfiltration in diabetic rats. Modulating the IGF-1 availability to the kidney by nitric oxide synthase inhibition significantly reduced renal hypertrophy and hyperfiltration during the first week of STZ-induced diabetes mellitus.

Intravenous iron in heart failure: beyond targeting anemia.

Iron deficiency is commonly seen in congestive heart failure (CHF) in both anemic and nonanemic patients. In six studies in which these iron-deficient patients with CHF were treated with intravenous (IV) iron, five found an improvement in the hemoglobin. In uncontrolled and controlled studies, the New York Heart Association (NYHA) class, quality of life, and exercise capacity were improved consistently with IV iron. In some studies, cardiac function also was improved. In one large, double-blind, placebo-controlled study of IV iron, the patient global assessment, quality of life, and NYHA class improved rapidly in both those who were anemic or not anemic. In contrast to these studies, another controlled study of anemia in CHF showed no effect of oral iron on hemoglobin or on any cardiac parameters over 1 year. These studies suggest that CHF in both anemic and nonanemic iron-deficient patients may benefit from a course of IV iron, but not oral iron.

Anaemia management in cardio renal disease.

Anaemia is common in congestive heart failure (CHF) and is associated with increased mortality, morbidity and progressive renal failure. The common causes of the anaemia are the associated renal failure and excessive cytokine production, both of which can cause depression of the erythropoietin (EPO) production in the kidney and depression of EPO response in bone marrow. The cytokines can also induce iron deficiency by increasing hepcidin production from the liver, which both reduces gastrointestinal iron absorption and reduces iron release from iron stores located in the macrophages and hepatocytes. Attempts to control this anaemia will have to consider the use of both erythropoiesis stimulating agents (ESA) as well as oral and, probably more importantly, intravenous (IV) iron. Studies of anaemia in CHF with ESA and oral or IV iron and even with IV iron alone have shown a positive effect on hospitalisation, fatigue and shortness of breath, cardiac and renal function, quality-of-life, exercise capacity and reduced beta natriuretic peptide and have not demonstrated an increase in cardiovascular damage related to therapy. Although some studies and meta-analyses have revealed improvement in these parameters others have not. Adequately powered long-term placebo-controlled studies of ESA and of IV iron in CHF are needed and are currently being carried out.

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.

Prevalence of chronic kidney disease and anemia in patients with coronary artery disease with normal serum creatinine undergoing percutaneous coronary interventions: relation to New York Heart Association class.

BACKGROUND: Kidney disease and cardiovascular disease seem to be lethally synergistic and both are approaching the epidemic level. A reduced glomerular filtration rate is associated with increased mortality risk in patients with heart failure. Many patients with congestive heart failure are anemic. Anemia is very often associated with chronic kidney disease. OBJECTIVES: To assess--in relation to New York Heart Association class--the prevalence of anemia and chronic kidney disease in patients with normal serum creatinine in a cohort of 526 consecutive patients with coronary artery disease undergoing percutaneous coronary interventions. METHODS: GFR was estimated using the simplified MDRD formula, the Cockcroft-Gault formula, the Jeliffe and the novel CKD-EPI formula. RESULTS: According to the WHO definition the prevalence of anemia in our study was 21%. We observed a progressive decline in GFR and hemoglobin concentration together with a rise in NYHA class. Significant correlations were observed between eGFR and systolic blood pressure, diastolic blood pressure, age, NYHA class, complications of PCI, including bleeding, and major adverse cardiac events. CONCLUSIONS: The prevalence of anemia and chronic kidney disease is high in patients undergoing PCI despite normal serum creatinine, particularly in higher NYHA class. Lower eGFR and hemoglobin are associated with more complications, including bleeding after PCI and higher prevalence of major adverse cardiac events. In patients with risk factors for cardiovascular disease, GFR should be estimated since renal dysfunction and subsequent anemia are important risk factors for cardiovascular morbidity and mortality.

The anemia of heart failure.

Anemia is common in congestive heart failure (CHF) and is associated with an increased mortality and morbidity. The most likely causes of anemia are chronic kidney disease (CKD) and excessive cytokine production, both of which can cause depression of erythropoietin (EPO) production and bone marrow activity. The cytokines also induce iron deficiency by both reducing gastrointestinal iron absorption and iron release from iron stores located in the macrophages and hepatocytes. Iron deficiency can cause thrombocytosis which might also contribute to cardiovascular complications in both CHF and CKD and is partially reversible with iron treatment. Thus attempts to control this anemia will have to consider both the use of erythropoiesis-stimulating agents (ESA), such as EPO, as well as oral and, probably more importantly, intravenous (IV) iron. The many studies on anemia in CHF patients treated with ESA and oral or IV iron, and even with IV iron without ESA have up to now shown a quite consistent positive effect on hospitalization, fatigue, shortness of breath, quality of life, exercise capacity, and beta-natriuretic peptide reduction, in the absence of increased cardiovascular damage related to the therapy. Adequately powered long-term placebo-controlled studies of ESA and/or IV iron are currently being carried out and their results are eagerly awaited.

Metabolic alkalosis in skilled nursing patients.

Renal failure is common among the long-term care (LTC) elderly. Little is known about the acid/base status of these patients. The aim of this study is to evaluate the relationship between the acid base status and renal function in a representative group of skilled nursing patients and relate it to their feeding status. LTC elderly patients, in stable clinical condition, 50 on naso-gastric tube (NGT) feeding, 40 orally fed (OF), were recruited to this study. As controls, we studied a group of 30 elderly independent, ambulatory patients admitted to the acute geriatric departments of the hospital for different causes which were not related to their acid-base status. Venous blood was taken for the routine tests and blood gases. In the LTC study groups a 24-h urine collection was examined for biochemical parameters and calculations of all clearances. Glomerular filtration rate (GFR) was estimated by the Cockroft and Goult and MDRD formulas. Renal function was similar in the two main study groups. Daily secretion of sodium and chloride were 50% lower in the NGT fed patients (p<0.001). The LTC elderly patients had significantly higher venous pH values, with no differences in pCO(2) or HCO(3). An alkalotic state (pH>7.45) was found in 13.6% of them (18% in the NGT and 6.5% in the OF) while none of the independent elderly had such values (p<0.05). Similarly, HCO(3)>34 was found in 12% of the LTC elderly versus none in the independents (p=0.06). Values of pO(2) and O(2) saturation were significantly higher in the nursing elderly and mainly those fed by NGT. Hemoglobin levels had a significantly negative correlation with the pH (r=-0.3, p<0.002). In conclusion, unexpected metabolic alkalosis was found in a group of skilled nursing patients, more prominent in those fed by NGT. This finding warrants the inclusion of routine pH determination in patients whenever pharmacokinetic considerations are essential.

The correction of anemia in patients with the combination of chronic kidney disease and congestive heart failure may prevent progression of both conditions.

It has recently been recognized that many patients with congestive heart failure (CHF) are anemic. The anemia is very often associated with chronic kidney disease (CKD). The more severe the anemia the more severe the CHF, with higher mortality, morbidity, and hospitalization rate. The only way to prove that the anemia is itself a causative factor in the progression of both the CKD and the CHF is to correct it. In this paper we review the results of published papers and some preliminary reports about correction of this anemia in CHF. These studies frequently showed that erythropoietic stimulating agents (ESA) with oral or IV iron often resulted in improvement in left ventricular systolic and diastolic function, dilation, and hypertrophy, stabilization or improvement in renal function, reduced hospitalizations, diuretic dose, mitral regurgitation, pulmonary artery pressure, plasma volume, heart rate, serum brain natriuretic peptide levels, and the inflammatory markers C reactive protein and Interleukin 6, and an improvement in New York Heart Association class, exercise capacity, oxygen utilization during exercise, sleep apnea, caloric intake, depression, and quality of life. The activity of endothelial progenitor cells was also increased. Iron deficiency may also play an important role in the anemia, because significant improvement of cardiac, renal, and functional status in these anemic CKD-CHF has been seen after treatment with IV iron alone. Clearly more work is needed to clarify the relationship between anemia, CKD and CHF.

The role of correction of anaemia in patients with congestive heart failure: a short review.

Many patients with Congestive Heart Failure (CHF) are anaemic. This anaemia is associated with more severe CHF and a higher incidence of mortality, hospitalisation and morbidity. The only way to prove that the anaemia is causing this worsening of CHF is to correct it. We review here some of the published papers about correction of anaemia. Many studies show a positive effect of Erythropoietin (EPO) or its' derivatives when administered in combination with oral or IV iron, with improvements in left and right ventricular systolic and diastolic function, dilation and hypertrophy and renal function. In addition, a reduction in hospitalisations, diuretic dose, pulmonary artery pressure, plasma volume, heart rate, serum Brain Natriuretic Peptide levels, the inflammatory marker Interleukin 6, soluble Fas ligand--a mediator of apoptosis, and improvements in New York Heart Association class, exercise capacity, oxygen utilization, caloric intake, Quality of Life and the activity of Endothelial Progenitor Cells, have been observed. Iron deficiency may also play an important role in this anaemia, since improvements in CHF have also been reported following treatment with IV iron alone. However, until the ongoing large placebo-controlled studies of the EPO derivative darbepoetin or IV iron are completed, we will not know whether these treatments really influence CHF outcome.

Tubular and glomerular L-arginine transport (uptake and transporters) and the nitric oxide synthases in ischemic acute renal failure (iARF) in streptozotocin-induced diabetic rats (STZ-DM).

BACKGROUND: L-arginine or its metabolites may be important pathogenetic factors in ischemic acute renal failure (iARF) in rats. It was found that the L-arginine-nitric oxide synthase-nitric oxide system plays an important role in the renal hemodynamic alterations in the early stages of diabetes. The iARF in diabetic rats is much more severe than the normal rats exposed to a same ischemia time. The purpose of the present study was to evaluated L-arginine uptake and its transporters and nitric oxide synthase isoform expression in tubuli and glomeruli of STZ-induced diabetic rats with iARF. METHODS: iARF was induced by right nephrectomy and left renal artery clamping for 60 min followed by a 60 min reflow period. iARF was induced in STZ diabetes rats two weeks after intraperitoneal streptozotocin (60 mg/kg body weight) and in normal control rats. L-arginine uptake, L-arginine transporters (CAT1 and CAT2) and nitric oxide synthases (iNOS, eNOS, and bNOS) were determined by RT-PCR) in both glomeruli and tubuli preparations. RESULTS: The STZ diabetic rats compared with the non diabetic normal rats have a higher glomerular L-arginine uptake, higher iNOS mRNA, lower eNOS mRNA, and lower tubular CAT1 mRNA, eNOS mRNA, and bNOS mRNA. The diabetic iARF after one hour of reperfusion had lower glomerular L-arginine uptake, lower CAT1 mRNA, lower eNOS mRNA, lower bNOS, and higher tubular iNOS mRNA compared with iARF in normal rats. CONCLUSIONS: Our findings suggest a prolonged and more severe post-glomerular vasoconstriction very early after the reflow in the iARF of STZ diabetic rats compared with the iARF in the normal control rats. That may be a plausible explanation to the very significant decline in GFR and tubular necrosis that characterize the iARF in diabetic rats.

The cardio-renal anemia syndrome.

Congestive heart failure, chronic kidney insufficiency and anemia are often present in the same patient. We have coined this triad the cardio-renal anemia syndrome. We suggest that congestive heart failure can often cause chronic renal failure, with both diseases producing anemia. The anemia exacerbates the chronic heart failure, which then worsens the chronic renal failure, causing further anemia, in a vicious cycle. Together with early detection and treatment of the chronic heart failure, correction of the associated anemia with a combination of subcutaneous erythropoietin and intravenous iron will often alleviate the chronic heart failure and slow down or stop the progression of the associated chronic kidney insufficiency.

Renal effects of low dose aspirin in elderly patients.

BACKGROUND: Aspirin is commonly used by elderly patients. In previous studies we found transient changes in renal function induced by low doses of aspirin. OBJECTIVES: To investigate the mechanisms of these effects. METHODS: The study group included 106 long-term care stable geriatric inpatients. Diet and drugs were kept stable. The study lasted 5 weeks; during the first 2 weeks 100 mg aspirin was administered once a day. Clinical and laboratory follow-up was performed at baseline and weekly for the next 3 weeks. The glomerular filtration rate was estimated by creatinine clearance measured in 24 hour urine and serum creatinine, and by the Cockcroft-Gault formula (C-G) equation. Uric acid clearance was determined from serum concentrations and 24 hour excretion of uric acid. Patients with serum creatinine > 1.5 mg/dl were not included. RESULTS: After 2 weeks on low dose aspirin, measured creatinine and uric acid clearances decreased significantly compared with the initial values in 70% and 62% of the patients, respectively, with mean decreases of 19% and 17%, respectively (P< 0.001). Blood urea nitrogen increased by 17% while serum creatinine and uric acid concentrations increased by 4% (P < 0.05 for all). The C-G values decreased by 3% (P< 0.05). After withdrawal of aspirin all parameters improved. However, 67% of the patients remained with some impairment in their measured Ccr, compared to baseline. Patients who reacted adversely to low dose aspirin had significantly better pre-study renal function (Ccr), lower hemoglobin and lower levels of serum albumin. CONCLUSIONS: Short-term low dose aspirin affected renal tubular creatinine and uric acid transport in the elderly, which may result in a prolonged or permanent deterioration of the renal function. It is suggested that renal functions be monitored even with the use of low dose aspirin in elderly patients.

The interaction between heart failure and other heart diseases, renal failure, and anemia.

Anemia, defined as a hemoglobin level of less than 12 g/dL, often is seen in congestive heart failure (CHF). It is associated with an increased mortality and morbidity and increased hospitalizations. Compared with nonanemic patients the presence of anemia also is associated with worse cardiac clinical status, more severe systolic and diastolic dysfunction, a higher beta natriuretic peptide level, increased extracellular and plasma volume, a more rapid deterioration of renal function, a lower quality of life, and increased medical costs. The only way to determine if anemia is merely a marker for more severe CHF or actually is contributing to the worsening of the CHF is to correct the anemia and see if this favorably influences the CHF. In several controlled and uncontrolled studies, correction of the anemia with subcutaneous erythropoietin (EPO) or darbepoetin in conjunction with oral and intravenous iron has been associated with an improvement in clinical status, number of hospitalizations, cardiac and renal function, and quality of life. However, larger, randomized, double-blind, controlled studies still are needed to verify these initial observations. The effect of EPO may be related partly to its nonhematologic functions including neovascularization; prevention of apoptosis of endothelial, myocardial, cerebral, and renal cells; increase in endothelial progenitor cells; and anti-inflammatory and antioxidant effects. Anemia also may play a role in increasing cardiovascular morbidity in chronic kidney insufficiency, diabetes, renal transplantation, asymptomatic left ventricular dysfunction, left ventricular hypertrophy, acute coronary syndromes including myocardial infarction and chronic coronary heart disease, and in cardiac surgery. Again, controlled studies of correction of anemia are needed to assess its importance in these conditions. The anemia in CHF mainly is caused by a combination of renal failure and CHF-induced increased cytokine production, and these can both lead to reduced production of EPO, resistance of the bone marrow to EPO stimulation, and to cytokine-induced iron-deficiency anemia caused by reduced intestinal absorption of iron and reduced release of iron from iron stores. The use of angiotensin-converting enzyme inhibitor and angiotensin receptor blockers also may inhibit the bone marrow response to EPO. Hemodilution caused by CHF also may cause a low hemoglobin level. Renal failure, cardiac failure, and anemia therefore all interact to cause or worsen each other--the so-called cardio-renal-anemia syndrome. Adequate treatment of all 3 conditions will slow down the progression of both the CHF and the chronic kidney insufficiency.

Anemia, chronic renal disease and congestive heart failure--the cardio renal anemia syndrome: the need for cooperation between cardiologists and nephrologists.

Many patients with congestive heart failure (CHF) fail to respond to maximal CHF therapy and progress to end stage CHF with many hospitalizations, poor quality of life (QoL), progressive chronic kidney disease (CKD) which can lead to end stage kidney disease (ESKD), or die of cardiovascular complications within a short time. One factor that has generally been ignored in many of these people is the fact that they are often anemic. The anemia in CHF is due mainly to the frequently-associated CKD but also to the inhibitory effects of cytokines on erythropoietin production and on bone marrow activity, as well as to their interference with iron absorption from the gut and their inhibiting effect on the release of iron from iron stores. Anemia itself may further worsen cardiac and renal function and make the patients resistant to standard CHF therapy. Indeed anemia in CHF has been associated with increased severity of CHF, increased hospitalization, worse cardiac function and functional class, the need for higher doses of diuretics, progressive worsening of renal function and reduced QoL. In both controlled and uncontrolled studies of CHF, the correction of the anemia with erythropoietin (EPO) and oral or intravenous (IV) iron has been associated with improvement in many cardiac and renal parameters and an increased QoL. EPO itself may also play a direct role in improving the heart unrelated to the improvement of the anemia--by reducing apoptosis of cardiac and endothelial cells, increasing the number of endothelial progenitor cells, and improving endothelial cell function and neovascularization of the heart. Anemia may also play a role in the worsening of acute myocardial infarction and chronic coronary heart disease (CHD) and in the cardiovascular complications of renal transplantation. Anemia, CHF and CKD interact as a vicious circle so as to cause or worsen each other- the so-called cardio renal anemia syndrome. Only adequate treatment of all three conditions can prevent the CHF and CKD from progressing.

Fucoidin, an inhibitor of leukocyte adhesion, exacerbates acute ischemic renal failure and stimulates nitric oxide synthesis.

OBJECTIVES: To lessen renal ischemic injury caused by fucoidin, a substance capable of reducing tissue infiltration by neutrophils, and to seek a possible interrelationship with the nitric oxide system which may also modulate leukocyte infiltration. MATERIAL AND METHODS: Acute ischemic renal failure was induced in rats by uninephrectomy followed by 60 min of clamping of the renal artery. The rats were injected with fucoidin (25 mg/kg) or fucoidin+nitroprusside (2.5 mg/kg) before reperfusion, and urine was collected for 24 h afterwards. Serum and urine were examined for creatinine sodium and protein; creatinine clearance and fractional excretion of sodium (FENa) were calculated. The renal tissue of the sacrificed animals was examined histologically for tissue damage and histochemically for myeloperoxidase, a marker of neutrophil infiltration. The nitric oxide system was evaluated by measuring urinary nitrates and inducible nitric oxide synthase messenger RNA (iNOs mRNA). RESULTS: Renal failure was more severe in the fucoidin group than the nitroprusside group (creatinine clearance 0.11+/-0.08 ml/min for ischemia+fucoidin versus 0.26+/-0.11 ml/min for ischemia only; p<0.002). Adding nitroprusside to fucoidin lessened the decline in creatinine clearance (0.13+/-0.13 ml/min; p=NS). Fucoidin was associated with greater tubular damage, as evidenced by increased FENa (7.2%+/-2.8% vs 1.51%+/-1.96% for ischemia only; p<0.001). Nitroprusside weakened this trend. Fucoidin caused an increase in the fractional excretion of nitrates, a response accompanied by increased iNOS mRNA. CONCLUSIONS: Fucoidin failed to protect the kidney from ischemic damage and was even nephrotoxic. It also stimulated the formation of iNOS RNA.

Therapy insight: congestive heart failure, chronic kidney disease and anemia, the cardio-renal-anemia syndrome.

Congestive heart failure (CHF) and chronic kidney disease (CKD) often progress to end stage even with optimum medical therapy. One factor that is common to both conditions is anemia, which is present in about a third of CHF patients. CHF can cause or worsen both anemia and CKD, and CKD can cause or worsen both anemia and CHF. Thus, a vicious circle exists between these three conditions, with each causing or worsening the other. We have called this condition the cardio-renal-anemia syndrome. Anemia in CHF is associated with increased mortality and hospitalization, reduced cardiac function and evidence of more severe CHF and CKD than in nonanemic patients. Intervention studies in anemic CHF patients have shown that optimum medical treatment of CHF and the correction of the associated anemia with subcutaneous erythropoietin and oral iron or intravenous iron sucrose can improve cardiac function, patients' functional status, renal function and quality of life, and reduce the frequency of hospitalization and the dose of diuretics required.

Erythropoietin in heart failure.

The incidence of both congestive heart failure (CHF) and end-stage renal disease both are increasing. Anemia is common in both conditions and is associated with a marked increase in mortality and morbidity in both CHF and chronic kidney insufficiency (CKI). Each of these 3 conditions can cause or worsen the other 2. In other words, a vicious circle frequently is present in which CHF can cause or worsen both anemia and CKI, in which CKI can cause or worsen both anemia and CHF, and in which anemia can cause or worsen both CHF and CKI. We have called this vicious circle the cardio renal anemia syndrome. Optimal treatment of CHF with all the recommended CHF medications at their recommended doses will, in our experience, frequently fail to improve the CHF and CKI if anemia is present and is not corrected. On the other hand, correction of the anemia with subcutaneous erythropoietin and intravenous iron has caused a great improvement in the CHF including a marked improvement in patient and cardiac function and a marked reduction in the need for hospitalization and for high-dose diuretics. It also frequently has caused renal function to improve or at least stabilize. In addition, patients' quality of life and exercise capacity also have improved with the correction of the anemia. In CKI patients, anemia also may play an important role in increasing the risk for death, coronary heart disease, stroke, and progression to end-stage renal disease. Erythropoietin may have a direct positive effect on the heart and brain unrelated to correction of the anemia by reducing cell apoptosis and by increasing neovascularization, both of which could prevent tissue damage. This could have profound therapeutic implications not only in CHF but in the future treatment of myocardial infarction, coronary heart disease, strokes, and renal failure.