***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND The optimal haemoglobin concentration ( [ Hb ] ) for patients with end-stage renal failure is uncertain . In particular , it is unclear whether Hb normalization may be an advantage to such patients who are otherwise well . METHODS A prospect i ve , r and omized , double-blind cross-over study was completed in 14 haemodialysis patients ( 12 male ) aged between 23 and 65 years over a period of 18 months , using a variety of measures to examine the effect of epoetin at target [ Hb ] of 10 g/dl ( [Hb](10 ) ) and 14 g/dl ( [Hb](14 ) ) . Patients were r and omized to maintain one or other of the target levels for 6 weeks before being crossed over to the alternative [ Hb ] . Baseline data ( mean [ Hb ] : 8.5+/-0.2 g/dl ) were also included selectively . Six patients were known to be hypertensive . Comparisons were made between 24-h ambulatory blood pressure levels ( ABP ) , echocardiographic findings and estimates of blood volume ( BV ) , plasma volume ( PV ) and Hb mass . Quality of life estimates were obtained using the Sickness Impact Profile ( SIP ) , and epoetin dosage requirements at target [ Hb ] were assessed . RESULTS Daytime and nocturnal ABP ( systolic and diastolic ) were not different at the respective target [ Hb ] , although nocturnal diastolic levels were higher compared with baseline ( 73+/-4 mmHg ) at both [Hb](10 ) ( 83+/-3 , P:<0.01 ) and [Hb](14 ) ( 81+/-6 , P:<0.05 ) . Significant reductions in cardiac output ( 5.2+/-0.3 vs 6.6+/-0.5 l/min , P:<0.01 ) and left ventricular end-diastolic diameter ( 4.8+/-0.2 vs 5.2+/-0.2 cm , P:<0 . 001 ) were found at [Hb](14 ) compared with [Hb](10 ) . Left ventricular mass index was correlated with both PV ( P:<0.001 ) and BV ( P:<0.01 ) , but not with Hb mass . The PV decreased as the [ Hb ] rose ( P:<0.001 ) but BV remained unchanged . Quality of life was significantly improved at [Hb](14 ) compared with [Hb](10 ) for both total score ( 6 . 5+/-1.7 vs 13.4+/-3.0 , P:=0.01 ) and psychosocial dimension score ( 5 . 4+/-1.9 vs 15.4+/-4.0 , P:<0.01 ) . The maintenance weekly dose of epoetin  required was 80 % higher at [Hb](14 ) compared with [Hb](10 ) ( P:<0.001 ) . CONCLUSION These data suggest there may be a significant haemodynamic and symptomatic advantage in maintaining a physiological [ Hb ] in haemodialysis patients . Although untoward effects were not identified in this study at [Hb](14 ) , a substantially higher dose of epoetin is required to maintain this level BACKGROUND Renal anemia is an important determinant for left ventricular hypertrophy in dialysis patients and an independent prognosis parameter for the cardiovascular survival in dialysis patients . In addition , an autonomic dysfunction is associated with the uremic state and influences the cardiovascular risk in patients with end-stage renal disease ( ESRD ) . METHODS We investigated in this prospect i ve longitudinal study the effect of hemoglobin normalization by a chronic treatment with recombinant human erythropoietin ( rhEPO ) on cardiovascular prognosis parameters in 23 patients on chronic hemodialysis with renal anemia ( hemoglobin concentration < or = 10.5 g/dL ) and echocardiographically proven left ventricular hypertrophy . We studied muscle sympathetic nerve activity measured by microneurography ; cardiopulmonary baroreflex activity by lower-body negative pressure ( LBNP- ) testing ; left ventricular structure and mass index ( LVMI ) by echocardiography ; blood pressure by 24-hour readings ; peripheral blood flow and vascular resistance by plethysmography before ( U1 ) and after 7 months of chronic rhEPO treatment ( U2 ) . RESULTS In the anemic state , mean ( + /- SD ) muscle sympathetic nerve activity in ESRD was elevated ( U1 rest , 34 + /- 13 bursts per minute ) and cardiopulmonary baroreflex response during LBNP markedly lacking ( U1 -15 mm Hg , 34 + /- 13 bursts per minute ) reflecting a severely impaired autonomic function . Normalization of the hemoglobin concentration by chronic rhEPO treatment ( U1 , 10.5 + /- 0.9 g/dL versus U2 , 13.4 + /- 3.1 g/dL , P < 0.001 ) did not influence sympathetic nerve activity ( U2 , 34 + /- 15 bursts per minute , NS ) and cardiopulmonary baroreflex sensitivity did not change ( U2 -15 mm Hg , 37 + /- 16 bursts per minute , NS ) . LVMI decreased significantly after chronic treatment with rhEPO ( U1 , 134 + /- 26 g/m2 versus U2 , 97 + /- 25 g/m2 , P < 0.001 ) and left ventricular geometry developed from an asymmetric to a symmetric configuration ( U1 , relative wall thickness 0.58 versus U2 , 0.43 , P < 0.001 ) . Under treatment with rhEPO , 24-hour systolic and diastolic blood pressure did not increase ( systolic U1 , 132 + /- 4 mm Hg versus U2 , 128 + /- 3 mm Hg , NS , and diastolic U1 , 76 + /- 2 mm Hg versus U2 , 73 + /- 2 mm Hg , NS ) . Peripheral blood flow ( U1 , 6.1 + /- 3.3 mL/100 mL/min versus U2 , 6.2 + /- 0.6 mL/100 mL/min , NS ) as well as forearm vascular resistance ( U1 , 15.7 + /- 3.3 mm Hg/mL/100 mL versus U2 , 14.9 + /- 3.1 mm Hg/mL/100 mL , NS ) did not change by chronic rhEPO treatment . CONCLUSION Normalization of hemoglobin by chronic rhEPO treatment in dialysis patients has beneficial cardiovascular effects with regression of left ventricular hypertrophy and improvement of left ventricular geometry . However , a reduction of sympathetic overactivity or a re setting of baroreceptor sensitivity by a rhEPO treatment in dialysis patients in the medium-term could not be demonstrated . The reason for this may be the complex and multifactorial pathomechanism of autonomic dysfunction and cardiovascular disease in ESRD Target hematocrit/hemoglobin values in dialysis patients are still controversial . The Spanish Cooperative Renal Patients Quality of Life Study Group ( including 34 hemodialysis units ) conducted a prospect i ve , 6-mo study of the effect on patient functional status and quality of life of using epoetin to achieve normal hematocrit in hemodialysis patients with anemia . The possible adverse effects of increased hematocrit , patient hospitalization , and epoetin requirements were also studied . The study included 156 patients ( age range , 18 to 65 yr ) . Given the minimal experience in the safety of increasing hematocrit in dialysis patients to normal levels with epoetin , stable patients on hemodialysis who had received epoetin treatment for at least 3 mo and had a stable hemoglobin level of > or = 9 g/dl were included in the study . Patients with antecedents of congestive cardiac failure , ischemic cardiopathy , diabetes mellitus , uncontrolled hypertension , cerebrovascular accident or seizures , malfunction of the vascular access or severe comorbidity ( defined by a comorbidity index ) , and those over 65 yr of age were excluded from the study . Quality of life was measured with the Sickness Impact Profile ( SIP ) and Karnofsky scale . Patients completed question naires at home at onset and conclusion of the 6-mo study . Mean hematocrit increased from 30.9 to 38.4 % and hemoglobin from 10.2 to 12.5 g/dl during the study . Health indicator scores improved significantly : mean Physical Dimension ( SIP ) from 5.38 to 4.1 ( P < 0.005 ) ; mean Psychosocial Dimension from 9.2 to 7 ( P < 0.001 ) ; mean global SIP from 8.9 to 7.25 ( P < 0.001 ) ; mean Karnofsky scale score from 75.6 to 78.4 ( P < 0.01 ) . ( SIP is scaled so that lower scores represent better functional status , and vice versa for the Karnofsky scale ) . Therefore , functional status and quality of life improved with increased hematocrit . No deaths occurred . Three patients ( 2 % ) were censored for hypertension and nine ( 5.7 % ) for thrombosis of the vascular access . The cumulative probability of thrombosis of the vascular access was 0.067 . The average epoetin dose rose from 93 + /- 62 U/kg per wk at onset to 141 + /- 80 U/kg per wk at conclusion , a 51 % increase . The number of patients hospitalized decreased and hospital lengths of stay were shorter during the study period than in the same patients in the 6-mo period preceding the study ( P < 0.05 ) . Nine patients ( 5.7 % ) had thrombosis of the vascular access . There were no changes in the prevalence of arterial hypertension , but three patients ( 2 % ) showed hypertension that was difficult to control . It is concluded that normalization of hematocrit in selected hemodialysis patients , i.e. , nondiabetic patients without severe cardiovascular or cerebrovascular comorbidities , improves quality of life and decreases morbidity without significant adverse effects BACKGROUND In patients with end-stage renal disease , anemia develops as a result of erythropoietin deficiency , and recombinant human erythropoietin ( epoetin ) is prescribed to correct the anemia partially . We examined the risks and benefits of normalizing the hematocrit in patients with cardiac disease who were undergoing hemodialysis . METHODS We studied 1233 patients with clinical evidence of congestive heart failure or ischemic heart disease who were undergoing hemodialysis :  618 patients were assigned to receive increasing doses of epoetin to achieve and maintain a hematocrit of 42 percent , and 615 were assigned to receive doses of epoetin sufficient to maintain a hematocrit of 30 percent throughout the study . The median duration of treatment was 14 months . The primary end point was the length of time to death or a first nonfatal myocardial infa rct ion . RESULTS After 29 months , there were 183 deaths and 19 first nonfatal myocardial infa rct ions among the patients in the normal-hematocrit group and 150 deaths and 14 nonfatal myocardial infa rct ions among those in the low-hematocrit group ( risk ratio for the normal-hematocrit group as compared with the low-hematocrit group , 1.3 ; 95 percent confidence interval , 0.9 to 1.9 ) . Although the difference in event-free survival between the two groups did not reach the prespecified statistical stopping boundary , the study was halted . The causes of death in the two groups were similar . The mortality rates decreased with increasing hematocrit values in both groups . The patients in the normal-hematocrit group had a decline in the adequacy of dialysis and received intravenous iron dextran more often than those in the low-hematocrit group . CONCLUSIONS In patients with clinical ly evident congestive heart failure or ischemic heart disease who are receiving hemodialysis , administration of epoetin to raise their hematocrit to 42 percent is not recommended We administered recombinant human erythropoietin to 25 anemic patients with end-stage renal disease who were undergoing hemodialysis . The recombinant human erythropoietin was given intravenously three times weekly after dialysis , and transfusion requirements , hematocrit , ferrokinetics , and reticulocyte responses were monitored . Over a range of doses between 15 and 500 units per kilogram of body weight , dose-dependent increases in effective erythropoiesis were noted . At 500 units per kilogram , changes in the hematocrit of as much as 10 percentage points were seen within three weeks , and increases in ferrokinetics of three to four times basal values , as measured by erythron transferrin uptake , were observed . Of 18 patients receiving effective doses of recombinant human erythropoietin , 12 who had required transfusions no longer needed them , and in 11 the hematocrit increased to 35 percent or more . Along with the rise in hematocrit , four patients had an increase in blood pressure , and a majority had increases in serum creatinine and potassium levels . No organ dysfunction or other toxic effects were observed , and no antibod 
    Output:
    
Providing EPO for a hemoglobin level of more than 10 to 11 g/dl had a cost-effectiveness higher than that of doing so for other hemoglobin levels .