Mortality In Incident Hemodialysis Patients Research Articles

Hyponatremia, Mineral Metabolism, and Mortality in Incident Maintenance Hemodialysis Patients: A Cohort Study

Hyponatremia is associated with increased mortality in chronic diseases. Recent animal studies also implicate hyponatremia in bone abnormalities. However, associations between hyponatremia, mineral bone abnormalities, and mortality in incident hemodialysis patients are unknown. Nonconcurrent prospective cohort study. Incident hemodialysis patients from the Accelerated Mortality on Renal Replacement (ArMORR) cohort with available serum sodium measurements from the time of dialysis therapy initiation (n = 6,127) were classified as hyponatremic (sodium, <135 mEq/L) or normonatremic (sodium, 135-145 mEq/L) based on glucose-corrected sodium level at the time of dialysis therapy initiation. Patients with sodium levels >145 mEq/L were excluded (n = 74). Hyponatremia (sodium, <135 mEq/L). Mineral bone abnormalities; rates of falls, fractures, and mortality. Hyponatremia and mineral bone abnormalities were assessed at the time of hemodialysis therapy initiation. Data for other outcomes were collected during a 1-year follow-up. Univariate and multivariable logistic and Cox proportion hazard analyses were conducted to compute ORs and HRs, respectively, with 95% CIs. 775 patients were hyponatremic and 5,278 were normonatremic at baseline. In univariate analyses, hyponatremia was associated with hypercalcemia (OR, 1.92; 95% CI, 1.11-3.30), elevated alkaline phosphatase level (OR, 1.36; 95% CI, 1.12-1.66), and hypoparathyroidism (OR, 1.40; 95% CI, 1.18-1.65). Similar relationships were observed in multivariable models. No statistically significant relationships were observed with phosphorus abnormalities, hypovitaminosis D, falls, or fractures. 965 (15.8%) patients had died at the 1-year follow up. Compared with normonatremic patients, hyponatremic patients had higher 1-year mortality in univariate (HR, 1.59; 95% CI, 1.34-1.87) and multivariable analyses (HR, 1.42; 95% CI, 1.19-1.69). Low rate of falls and fractures, lack of data for bone density and fibroblast growth factor 23. In incident hemodialysis patients, hyponatremia is associated with hypercalcemia, elevated alkaline phosphatase levels, hypoparathyroidism, and increased 1-year mortality. Future studies are needed to examine whether treatments to alter hyponatremia have effects on mineral bone abnormalities and mortality.

Association of Cardiac Valvular Calcifications and C-Reactive Protein With Cardiovascular Mortality in Incident Hemodialysis Patients: A Japanese Cohort Study

Cardiac valve calcification is seen frequently in patients undergoing dialysis. Serum C-reactive protein (CRP) level also is reported to predict future cardiovascular events. We investigated the association among valve calcification, CRP level, and mortality in patients with end-stage renal disease who were just beginning hemodialysis (HD) therapy. Observational cohort. 1,290 consecutive patients who just started HD therapy were enrolled and were followed up to 10 years. Patients were divided into 3 groups according to number of calcified valves: those without valve calcification, those with calcification in a single (aortic or mitral) valve, and those with calcification in both valves. They also were divided into tertiles according to CRP level. Cardiovascular and all-cause mortality. Echocardiography and CRP measurement were performed within 1 month after beginning HD therapy. During follow-up (median, 51 months), 335 (25.9%) patients died, including 156 (12.1%) of cardiovascular disease. The adjusted HR for cardiovascular mortality was 2.80 (95% CI, 1.63-4.81) for 2 calcifications versus 0 (P < 0.001). Furthermore, the risk of cardiovascular mortality was 3.66-fold higher in patients with calcifications in both valves (highest tertile of CRP) compared with patients without valve calcification (lowest tertile of CRP; P < 0.001). Precise medical treatments or therapeutic interventions were not evaluated. Valve calcification and elevated CRP levels were not only related to additively increased risk of mortality, but also improved the prediction of mortality in patients with end-stage renal disease who had just begun HD therapy.

Serum β-Trace Protein and Risk of Mortality in Incident Hemodialysis Patients

Residual kidney function in dialysis patients is associated with better survival, but there are no simple methods for its assessment. β-Trace protein is a novel endogenous filtration marker of kidney function that is not removed during hemodialysis and may serve as a marker for residual kidney function similar to serum creatinine in patients not on dialysis. The objective of this study was to determine the association of serum β-trace protein with mortality in incident hemodialysis patients. Serum β-trace protein was measured in baseline samples from 503 participants of a national prospective cohort study of incident dialysis patients with enrollment during 1995-1998 and follow-up until 2004. Outcomes were all-cause and cardiovascular disease mortality analyzed using Cox regression adjusted for demographic, clinical, and treatment factors. Serum β-trace protein levels were higher in individuals with no urine output compared with individuals with urine output (9.0±3.5 versus 7.6±3.1 mg/L; P<0.001). There were 321 deaths (159 deaths from cardiovascular disease) during follow-up (median=3.3 years). Higher β-trace protein levels were associated with higher risk of mortality. The adjusted hazard ratio and 95% confidence interval for all-cause mortality per doubling of serum β-trace protein was 1.36 (1.09-1.69). The adjusted hazard ratios (95% confidence intervals) for all-cause mortality in the middle and highest tertiles compared with the lowest tertile were 0.95 (0.69-1.32) and 1.72 (1.25-2.37). Similar results were noted for cardiovascular disease mortality. The serum level of β-trace protein is an independent predictor of death and cardiovascular disease mortality in incident hemodialysis patients.

Patterns and Predictors of Early Mortality in Incident Hemodialysis Patients: New Insights

Background: Incident hemodialysis patients have the highest mortality in the first several months after starting dialysis treatments. We hypothesized that the patterns and risk factors associated with this early mortality differ from those in later dialysis therapy periods. Methods: We examined mortality patterns and predictors during the first several months of hemodialysis treatment in 18,707 incident patients since the first week of hemodialysis therapy and estimated the population attributable fractions for selected time periods in the first 24 months. Results: The 18,707 incident hemodialysis patients were 45% women and 54% diabetics. The standardized mortality ratios (95% confidence interval) in the 1st to 3rd month of hemodialysis therapy were 1.81 (1.74–1.88), 1.79 (1.72–1.86), and 1.34 (1.27–1.40), respectively. The standardized mortality ratio reached prevalent mortality only by the 7th month. No survival advantage for African Americans existed in the first 6 months. Patients with low albumin <3.5 g/dl had the highest proportion of infection-related deaths while patients with higher albumin levels had higher cardiovascular deaths including 76% of deaths during the first 3 months. Use of catheter as vascular access and hypoalbuminemia <3.5 g/dl explained 34% (17–54%) and 33% (19–45%) of all deaths in the first 90 days, respectively. Conclusions: Incident hemodialysis patients have the highest mortality during the first 6 months including 80% higher death risk in the first 2 months. The presence of a central venous catheter and hypoalbuminemia <3.5 g/dl each explain one third of all deaths in the first 90 days.

Electrocardiographic left ventricular hypertrophy and outcome in hemodialysis patients.

Background and AimsElectrocardiography (ECG) is the most widely used initial screening test for the assessment of left ventricular hypertrophy (LVH), an independent predictor of cardiovascular mortality in patients with end-stage renal disease (ESRD). However, traditional ECG criteria based only on voltage to detect LVH have limited clinical utility for the detection of LVH because of their poor sensitivity.MethodsThis prospective observational study was undertaken to compare the prognostic significance of commonly used ECG criteria for LVH, namely Sokolow-Lyon voltage (SV) or voltage-duration product (SP) and Cornell voltage (CV) or voltage-duration product (CP) criteria, and to investigate the association between echocardiographic LV mass index (LVMI) and ECG-LVH criteria in ESRD patients, who consecutively started maintenance hemodialysis (HD) between January 2006 and December 2008.ResultsA total of 317 patients, who underwent both ECG and echocardiography, were included. Compared to SV and CV criteria, SP and CP criteria, respectively, correlated more closely with LVMI. In addition, CP criteria provided the highest positive predictive value for echocardiographic LVH. The 5-year cardiovascular survival rates were significantly lower in patients with ECG-LVH by each criterion. In multivariate analyses, echocardiographic LVH [adjusted hazard ratio (HR): 11.71; 95% confidence interval (CI): 1.57–87.18; P = 0.016] and ECG-LVH by SP (HR: 3.43; 95% CI: 1.32–8.92; P = 0.011) and CP (HR: 3.07; 95% CI: 1.16–8.11; P = 0.024) criteria, but not SV and CV criteria, were significantly associated with cardiovascular mortality.ConclusionsThe product of QRS voltage and duration is helpful in identifying the presence of LVH and predicting cardiovascular mortality in incident HD patients.

Persistently low intact parathyroid hormone levels predict a progression of aortic arch calcification in incident hemodialysis patients

Recent observational studies have found that low intact parathyroid hormone (iPTH) is related with mortality in hemodialysis patients and these findings may be considered to be the result of accelerated cardiovascular calcifications in adynamic bone disease. This study was aimed to determine the relationship between persistently low iPTH and aortic arch calcification (AAC) in incident hemodialysis patients. From January 2004 to December 2008, a total of 94 incident hemodialysis patients were enrolled in this study. They were divided into three groups according to the changing patterns of iPTH during the first year of hemodialysis. ACC was scored on posterior-anterior plain chest X-rays using a specific scale at the initiation of dialysis and followed till May 2011. The median follow-up periods were 46.9 months. The prevalence of baseline AAC and its progression were the highest in the persistently low iPTH group. Also, all-cause mortality was the highest in this group. Age, baseline calcification score and persistently low iPTH independently contributed to the progression of calcification by multivariate logistic regression analyses (HR 1.083, 95% CI 1.023-1.147, P = 0.006; HR 3.320, 95% CI 1.023-10.789, P = 0.046; HR 5.207, 95% CI 1.027-26.412, P = 0.046, respectively). Also, mortality was relatively higher in calcification progressor compared to non-progressor (39.3, 18.2%, P = 0.030). Persistently low iPTH was an independent risk factor for both AAC and mortality in incident hemodialysis patients.

The Impact of Residual Renal Function on Hospitalization and Mortality in Incident Hemodialysis Patients

Background/Aims: Few data are available on the impact of residual renal function (RRF) on mortality and hospitalization in hemodialysis (HD) patients. The objective of our study was to compare clinical outcomes for HD patients with and without RRF. Methods: In a cohort of 118 incident HD patients with RRF (n = 51) and without RRF (n = 67) who started dialysis in a single center, we recorded demographics, laboratory data, medication, hospitalizations and mortality. Results: Patients without RRF were older (p = 0.007), had lower baseline serum albumin levels (p = 0.002) and spent 18.6 more days in hospital per year than those with RRF (p = 0.055). Mean survival time was significantly lower in patients without RRF (p = 0.027). In a Cox proportional hazards model, only RRF remained as a significant independent predictor. Conclusions: RRF is associated with significantly reduced mortality and hospital days, but does not decrease the hospitalization rate and time to first hospitalization.

Cardiovascular Disease and CKD: Core Curriculum 2010

Cardiovascular Disease and CKD: Core Curriculum 2010

Impact of the clinical conditions at dialysis initiation on mortality in incident haemodialysis patients: a national cohort study in Taiwan

Glomerular filtration rate (GFR) and co-morbidity at dialysis initiation in relation to mortality in end-stage renal disease is still controversial. We studied factors potentially related to the mortality in incident haemodialysis (HD) patients. A national database included 23 551 incident HD patients from July 2001 to December 2004. Kaplan-Meier and Cox regression analyses were performed to assess the association between GFR estimated by the four-variable Modified Diet in Renal Disease equation and all-cause mortality. Analyses were performed from Day 91 after the start of dialysis. Patients were classified into five groups (quintiles) based on estimated glomerular filtration rate (eGFR) at the start of dialysis. The median eGFR at dialysis initiation was low (4.7 mL/min/1.73 m(2)), as was the mortality in the first year of dialysis [13.2/100 patient-year, 95% confidence interval (95% CI) = 12.8-13.7]. There was an inverse association between lower eGFR and higher survival rate. The Cox regression model revealed an increase in mortality risk in Q5 (hazard ratio [HR] = 2.44, 95% CI = 2.11-2.81), Q4 (HR = 1.66, 95% CI = 1.43-1.93), Q3 (HR = 1.21, 95% CI = 1.04-1.41) and Q2 (HR = 1.18, 95% CI = 1.01-1.37) compared with the reference group of Q1 after adjusting for year of application, primary diseases (chronic glomerulonephritis, diabetic nephropathy, hypertension, chronic tubulointerstitial nephritis and others), demographics (age, sex), presence of co-morbidity (diabetes mellitus, hypertension, congestive heart failure, ischaemic heart diseases, cerebrovascular diseases, malignancies, liver cirrhosis, tuberculosis, other diseases and free of reported of co-morbidities) and haematocrit. Propensity score analysis also showed a higher eGFR to be associated with increased mortality risks. Adjustment for all covariates explained a high percentage of excess risk of mortality in the groups with low eGFR, but less risk in the groups with higher eGFR. Lower eGFR at dialysis initiation is associated with lower mortality. Conditions at dialysis initiation explained excess 1-year mortality risk differently in patients who began dialysis at different levels of eGFR. Other factors likely contribute to the mortality of patients initiating dialysis at higher eGFR levels, and further study is needed.

Mortality in incident haemodialysis patients: time-dependent haemoglobin levels and erythropoiesis-stimulating agent dose are independent predictive factors in the ANSWER study

Although the association between low haemoglobin levels and mortality is well established in haemodialysis patients, data are conflicting regarding levels >12 g/dl. In addition, divergent results have been reported on the relation between erythropoiesis-stimulating agents (ESAs) and mortality. This was a multicentre, observational, prospective, 24-month study, which recruited Spanish incident haemodialysis patients (N = 2310). Univariate and multivariate time-dependent Cox regression models examined the longitudinal association of mortality with haemoglobin and ESA dose; adjustment was made for iron deficiency and other confounders. After adjusting for age, functional status, body mass index, albumin levels, catheter as vascular access, previous history of cardiovascular disease, neoplasia, and ESA dose, mortality decreased with increasing haemoglobin. Adjusted hazard ratios relative to the reference category (11-12 g/dl) and 95% confidence intervals were: 1.36 (1.01-1.86) for <or=10 g/dl, 1.03 (0.75-1.42) for 10-11 g/dl, 0.93 (0.68-1.26) for 12-13 g/dl and 0.69 (0.49-0.97) for >13 g/dl. Independent of haemoglobin, patients on sustained ESA doses of 1-4000 IU/week and 8001-16 000 IU/week had better survival than non-treated (reference) patients, with adjusted hazard ratios of 0.61 (0.41-0.90) and 0.68 (0.49-0.94), respectively. No significant difference was found for doses of 4001-8000 IU/week or >16,000 IU/week, adjusted hazard ratios of 0.87 (0.63-1.20) and 0.89 (0.63-1.28), respectively. Higher haemoglobin levels are associated with lower mortality in Spanish incident haemodialysis patients, regardless of ESA dose, comorbidity, vascular access or malnutrition. No increase in mortality occurs for high ESA doses, independent of haemoglobin levels.

Association of Blood Pressure Increases During Hemodialysis With 2-Year Mortality in Incident Hemodialysis Patients: A Secondary Analysis of the Dialysis Morbidity and Mortality Wave 2 Study

Intradialytic increases in blood pressure (BP) can complicate the management of hypertension in hemodialysis (HD) patients. However, the long-term consequences are uncertain. Thus, we sought to determine whether BP increases during HD were associated with greater 2-year mortality in incident HD patients. Secondary analysis of a prospective dialysis cohort. Incident HD patients in the Dialysis Morbidity and Mortality Wave 2 Study. Changes in systolic BP (SBP) during HD (ie, postdialysis SBP -- predialysis SBP), averaged from 3 HD sessions before enrollment. Time to 2-year all-cause mortality. Cox regression was used to model hazard ratios for mortality associated with changes in SBP during HD while adjusting for demographics, comorbid conditions, interdialytic weight gain, laboratory variables, and antihypertensive agents. Of 1,748 patients, 12.2% showed greater than 10-mm Hg increases in SBP during HD. In adjusted analyses, every 10-mm Hg increase in SBP during HD was associated independently with a 6% increased hazard of death (hazard ratio, 1.06; 95% confidence interval, 1.01 to 1.11). When also adjusted for diastolic BP and postdialysis SBP, the adjusted hazard of death associated with increasing SBP during HD remained significant (hazard ratio, 1.12; 95% confidence interval, 1.05 to 1.21 per 10-mm Hg increase in SBP during HD). However, in analyses adjusted for predialysis SBP, there was a significant interaction between change in SBP and predialysis SBP. In analyses stratified by predialysis SBP, trends for increased mortality associated with increasing SBP during dialysis were present in patients with predialysis SBP less than 160 mm Hg. However, this relationship was significant only in patients with predialysis SBP less than 120 mm Hg. Secondary analysis with a limited number of baseline BP measurements and limited information about dialysis prescription. Increasing SBP by more than 10 mm Hg during HD occurs in approximately 10% of incident patients, and although increasing SBP during HD was associated with decreased 2-year survival, these findings were limited to patients with predialysis SBP less than 120 mm Hg.

Association Between Long-term Blood Pressure Variability and Mortality Among Incident Hemodialysis Patients

Blood pressure variability (BPV) is one putative risk factor for cardiovascular disease and mortality in hemodialysis patients. The purposes of this study are to identify a suitable metric of long-term BPV in this population and determine whether an association between BPV and all-cause mortality exists. Retrospective cohort study. Patients from the Accelerated Mortality on Renal Replacement (ArMORR) cohort who were adult, incident to hemodialysis at any Fresenius Medical Care unit between June 2004 and August 2005, and had suitable blood pressure data were studied (n = 6,961). Predialysis blood pressures measured between dialysis days 91 and 180 were used to determine each patient's absolute level of, trend in (slope over time), and variability in blood pressure. All-cause mortality beginning immediately after day 180 and continuing through day 365 or until censoring (median follow-up, 185 days). Of the 4 candidate BPV metrics, only average residual-intercept ratio adequately distinguished BPV from absolute blood pressure level and temporal blood pressure trend. In the primary analysis, each SD increase in systolic and diastolic BPV was associated with adjusted hazard ratios for all-cause mortality of 1.13 (95% confidence interval, 1.03 to 1.23) and 1.15 (95% confidence interval, 1.06 to 1.26), respectively. Results were consistent across multiple sensitivity analyses in which inclusion and exclusion criteria and timing of blood pressure measurements were varied. Contingency of results on the validity of mathematic description of BPV; potential for misclassification bias and residual confounding. Provided the mathematical descriptions of BPV are valid, the data suggest that systolic and diastolic BPV is associated with all-cause mortality in incident hemodialysis patients. Additional study is necessary to confirm and generalize findings, assess the interplay between systolic and diastolic BPV, and assess causality.

N-terminal Pro-B–Type Natriuretic Peptide (NT-proBNP) Concentrations in Hemodialysis Patients: Prognostic Value of Baseline and Follow-up Measurements

Increased N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations are associated with increased cardiovascular mortality in chronic hemodialysis patients. Previous studies focused on prevalent dialysis patients and examined single measurements of NT-proBNP in time. We measured NT-proBNP concentrations in 2990 incident hemodialysis patients to examine the risk of 90-day and 1-year mortality associated with baseline NT-proBNP concentrations. In addition, we calculated the change in concentrations after 3 months in a subset of 585 patients to examine the association between longitudinal changes in NT-proBNP and subsequent mortality. Increasing quartiles of NT-proBNP were associated with a monotonic increase in 90-day [quartile 1, referent; from quartile 2 to quartile 4, hazard ratio (HR) 1.7-6.3, P < 0.001] and 1-year (quartile 1, referent; from quartile 2 to quartile 4, HR 1.7-4.9, P < 0.001) all-cause mortality. After multivariable adjustment, these associations remained robust. When examined using a multivariable fractional polynomial, increased NT-proBNP concentrations were associated with increased 90-day (HR per unit increase in log NT-proBNP 1.5, 95% CI 1.3-1.7) and 1-year (HR per unit increase in log NT-proBNP 1.4, 95% CI 1.3-1.5) all-cause mortality. In addition, patients with the greatest increase in NT-proBNP after 3 months of dialysis had a 2.4-fold higher risk of mortality than those with the greatest decrease in NT-proBNP. NT-proBNP concentrations are independently associated with mortality in incident hemodialysis patients. Furthermore, the observation that longitudinal changes in NT-proBNP concentrations were associated with subsequent mortality suggests that monitoring serial NT-proBNP concentrations may represent a novel tool for assessing adequacy and guiding therapy in patients initiating hemodialysis.

Reducing morbidity and mortality in incident hemodialysis patients with an early intervention program

Reducing morbidity and mortality in incident hemodialysis patients with an early intervention program

Vitamin D as a novel nontraditional risk factor for mortality in hemodialysis patients: The need for randomized trials

Vitamin D has been used in the context of secondary hyperparathyroidism in patients with end-stage renal disease. A wave of recent studies suggests that vitamin D treatment may be associated with decreased mortality risk in these patients. The article by Wolf et al. further supports these studies by identifying vitamin D deficiency as a risk factor for early mortality in incident hemodialysis patients.

Nutritional Parameters and Mortality in Incident Hemodialysis Patients

To evaluate the impact of nutritional parameters at the time of initiation of hemodialysis (HD) on mortality. Retrospective study. Dialysis Unit of the Federal University of Sao Paulo, Oswaldo Ramos Foundation. Three hundred forty-four incident HD patients (60.5% male, 26% diabetic) with the first nutritional evaluation performed before completing 3 months of onset of HD were included. The study consisted of baseline measurements of several nutritional parameters (triceps skinfold thickness [TSF], midarm muscle circumference [MAMC], body mass index [BMI], serum albumin, serum creatinine, and protein and energy intake assessed by 3-day food diary) and records of outcome (death) over a period of 10 years. Muscle and/or fat depletion was observed in 51% of the studied patients, according to the percent standard of MAMC and TSF, respectively. Presence of diabetes, age over 60 years, serum albumin < 3.5 g/dL, MAMC adequacy < 90%, protein intake < 1.0 g/kg/d, and energy intake < 25 kcal/kg/d were associated with worse survival. When patients were analyzed according to tertiles of dialysis vintage, BMI > or = 25 (calculated as kg/m2) had a negative impact on survival only in the highest tertile (> 2.45 years). Patients with BMI < 25 and MAMC adequacy > or = 90% showed the best survival over the study period, and those with BMI > or = 25 but MAMC adequacy < 90% had the worst survival (P = .004). In the multivariate survival analysis adjusting for diabetes, advanced age, and hypoalbuminemia, the reduced MAMC (P = .008) and the low energy intake (P = .03) were independent predictors of death in incident HD patients. Reduced MAMC and low energy intake at the beginning of chronic dialysis are risk factors for mortality. A negative effect of high BMI on survival was associated with reduced MAMC and longer dialysis vintage.

Reuse-Associated Mortality in Incident Hemodialysis Patients in the United States, 2000 to 2001

The impact of dialyzer reuse on the mortality of hemodialysis patients is debated. This study assesses reuse-associated mortality across US dialysis provider systems (for-profit, not-for-profit; hospital-based, and freestanding units) in incident patients. Incident Medicare hemodialysis patients who initiated dialysis therapy from January 1, 2000, to December 31, 2001, were included and followed up to December 31, 2002. A 3-month entry period was used to determine comorbidity and disease severity. Applying various analytic approaches, mortality rates for patients treated with reused (or reprocessed) or single-use dialyzers were compared. Because of differences among dialysis units, facility clustering was addressed. Of 75,831 patients, 61,391 patients (81.0%) were classified as on reuse, and 14,440 patients (19.0%), as on single use, as of the start of follow-up. The overall mortality rate was 25.0/100 patient-years. No difference in mortality risk was found between patients treated with reuse compared with single use in an intent-to-treat approach (hazard ratio, 0.98; 95% confidence interval, 0.94 to 1.02; P = 0.266) after adjusting for chain affiliation, for-profit status, year of dialysis inception, age, sex, race, renal diagnosis, comorbidity, and hospitalization days. Findings were similar in an as-treated approach (hazard ratio, 0.97; 95% confidence interval, 0.93 to 1.01; P = 0.136). No survival advantage associated with single use was found for subgroups. No overall survival advantage or disadvantage is associated with dialyzer reuse compared with single use in incident hemodialysis patients in the United States; however, continued monitoring is advised.

Association of hematocrit value with cardiovascular morbidity and mortality in incident hemodialysis patients

Associations between hematocrit values and clinical outcome have been studied with conflicting results in cardiac patients, end-stage renal disease (ESRD) patients, and ESRD patients with cardiac disease. We studied dialysis patients to determine the relationship between hematocrit value and cardiac risk under current Dialysis Outcomes Quality Initiative (DOQI) practices. METHODS; Medicare data were used to study 50,579 incident hemodialysis patients selected from January 1, 1998, to December 31, 1999, who received hemodialysis for 9 months after the onset of ESRD. Patients were divided into groups on the basis of the hematocrit value: < or =30%, >30% to < or =33%, >33% to < or =36%, >36% to < or =39%, and >39%. For hospitalization, the follow-up extended to 21/2 years; for mortality, 3 years. Compared to patients with hematocrit values of >33% to < or =36%, patients with values of >36% to < or =39% and those with values of >39% had risk ratios for hospitalization due to cardiac disease of 0.92 (95% CI 0.88 to 0.97) and 0.79 (95% CI 0.72 to 0.87), respectively, and risk ratios for death due to cardiac disease of 0.92 (95% CI 0.87 to 0.98) and 0.83 (95% CI 0.74 to 0.93), respectively, in the follow-up period. The significant associations we report do not establish a causal relationship between higher hematocrit values and lower risks of cardiac morbidity and mortality. A randomized clinical trial in low-risk patients is needed to establish causality.