Racial differences in clinical use of cinacalcet in a large population of hemodialysis patients.

BACKGROUND/AIMS: African-Americans with end-stage renal disease receiving dialysis have more severe secondary hyperparathyroidism than Whites. We aimed to assess racial differences in clinical use of cinacalcet. METHODS: This retrospective cohort study used data from DaVita, Inc., for 45,589 prevalent hemodialysis patients, August 2004, linked to Centers for Medicare & Medicaid Services data, with follow-up through July 2007. Patients with Medicare as primary payer, intravenous vitamin D use, or weighted mean parathyroid hormone (PTH) level >150 pg/ml at baseline (August 1-October 31, 2004) were included. Cox proportional hazard modeling was used to evaluate race and other demographic and clinical characteristics as predictors of cinacalcet initiation, titration, and discontinuation. RESULTS: Of 16,897 included patients, 7,674 (45.4%) were African-American and 9,223 (54.6%) were white; 53.2% of cinacalcet users were African-American. Cinacalcet was prescribed for 47.7% of African-Americans and 34.5% of Whites, and for a greater percentage of African-Americans at higher doses at each PTH strata. After covariate adjustment, African-Americans were more likely than Whites to receive cinacalcet prescriptions (hazard ratio 1.17, p < 0.001). The direction and magnitude of this effect appeared to vary by age, baseline PTH, and calcium, and by elemental calcium use. African-Americans were less likely than Whites to have prescriptions discontinued and slightly more likely to undergo uptitration (hazard ratio 1.09, 95% confidence interval 0.995-1.188), but this relationship lacked statistical significance. CONCLUSION: Cinacalcet is prescribed more commonly and at higher initial doses for African-Americans than for Whites to manage secondary hyperparathyroidism.

Trends in hip fracture rates in US hemodialysis patients, 1993-2010.

BACKGROUND: Changes in mineral and bone disorder treatment patterns and demographic changes in the dialysis population may have influenced hip fracture rates in US dialysis patients in 1993-2010. STUDY DESIGN: Retrospective follow-up study analyzing trends over time in hospitalized hip fracture rates. SETTING & PARTICIPANTS: Using Medicare data, we created 2 point-prevalent study cohorts for each study year. Hemodialysis cohorts included patients with Medicare as primary payer receiving hemodialysis in the United States on January 1 of each year; non-end-stage renal disease (ESRD) cohorts included Medicare beneficiaries 66 years or older on January 1 of each year. FACTORS: Age, sex, race, primary cause of ESRD, dual Medicare/Medicaid enrollment status, comorbid conditions. OUTCOMES: Hip fracture rates. MEASUREMENTS: Unadjusted hip fracture rates measured using number of events per 1,000 person-years in each year, then adjusted for patient characteristics. Poisson models estimated strata-specific event rates. RESULTS: The observed number of first hospitalized hip fracture events and the adjusted hip fracture rate increased steadily from 1993 (831 events; 11.9/1,000 person-years), peaked in 2004 (3,256 events; 21.9/1,000 person-years), and decreased through 2010 (2,912 events; 16.6/1,000 person-years). The trend for the subset of hemodialysis patients 66 years or older was similar to the trend for the full hemodialysis cohort; however, it differed markedly in magnitude and pattern from the non-ESRD Medicare cohort, for which rates were substantially lower and slowly decreasing since 1996. LIMITATIONS: Unable to provide causal explanations for observed changes; hip fractures identified through inpatient episodes; results do not describe hemodialysis patients without Medicare Parts A and B; laboratory values unavailable in the Medicare data set. CONCLUSIONS: Temporal trends in hip fracture rates among Medicare hemodialysis patients differ markedly from the steadily decreasing trend in non-ESRD Medicare beneficiaries, showing a relatively rapid increase until 2004 and relatively rapid decrease thereafter. Further research is needed to define associated factors.

Evaluating real-world use of cinacalcet and biochemical response to therapy in US hemodialysis patients.

BACKGROUND/AIMS: Data describing real-world use and effectiveness of cinacalcet are limited. We aimed to characterize predictors of treatment and changes in secondary hyperparathyroidism (SHPT) biochemistry after cinacalcet initiation. METHODS: We studied 25,250 in-center hemodialysis patients from a large dialysis provider, alive through November 2004, with no prior cinacalcet prescription. Patients were followed until initiation of cinacalcet, censoring, death, or July 31, 2007. Initiators were further followed for dose titration and discontinuation. Predictors of these events were evaluated using Cox proportional hazards modeling. Biochemical parameters and other SHPT medication use were compared between baseline, pre-initiation, and post-initiation time points. RESULTS: Over an average of 1.25 years of follow-up, 30% of patients initiated cinacalcet therapy. Between baseline and initiation (mean of 386 days), parathyroid hormone (PTH) and phosphorus levels increased 78 and 7%, respectively, in these patients. After adjustment, cinacalcet initiation was associated with higher SHPT severity, younger age, African-American race, higher phosphorus levels, and more comorbidity. Within 1 month of initiation, median PTH was reduced by 15-30% and phosphorus by 3-5%. Reductions were sustained or increased over 12 months, depending on initiating PTH level and whether dose up-titration occurred. Discontinuation was common, although many patients reinitiated. CONCLUSIONS: A substantial proportion of patients experienced SHPT progression and initiated cinacalcet treatment. Reductions in biochemistry varied by disease severity and whether doses were titrated.

Impact of hemodialysis catheter dysfunction on dialysis and other medical services: an observational cohort study.

Practice guidelines define hemodialysis catheter dysfunction as blood flow rate (BFR) <300 mL/min. We conducted a study using data from DaVita and the United States Renal Data System to evaluate the impact of catheter dysfunction on dialysis and other medical services. Patients were included if they had ≥8 consecutive weeks of catheter dialysis between 8/2004 and 12/2006. Actual BFR <300 mL/min despite planned BFR ≥300 mL/min was used to define catheter dysfunction during each dialysis session. Among 9,707 patients, the average age was 62,53% were female, and 40% were black. The median duration of catheter dialysis was 190 days, and the cohort accounted for 1,075,701 catheter dialysis sessions. There were 70,361 sessions with catheter dysfunction, and 6,33 1 (65.2%) patients had at least one session with catheter dysfunction. In multivariate repeated measures analysis, catheter dysfunction was associated with increased odds of missing a dialysis session due to access problems (Odds ratio [OR] 2.50; P < 0.001), having an access-related procedure (OR 2.10; P < 0.001), and being hospitalized (OR 1.10; P = 0.001). Catheter dysfunction defined according to NKF vascular access guidelines results in disruptions of dialysis treatment and increased use of other medical services.

Association of family history of ESRD, prevalent albuminuria, and reduced GFR with incident ESRD.

BACKGROUND: The contribution of albuminuria to the increased risk of incident end-stage renal disease (ESRD) in individuals with a family history of ESRD has not been well studied. STUDY DESIGN: Prospective cohort study. STUDY SETTING & PARTICIPANTS: We analyzed data for family history of ESRD collected from 19,409 participants of the Renal REGARDS (Reasons for Geographic and Racial Differences in Stroke) cohort study. PREDICTOR: Family history of ESRD was ascertained by asking "Has anyone in your immediate family ever been told that he or she had kidney failure? This would be someone who is on or had been on dialysis or someone who had a kidney transplant." STUDY OUTCOMES: Incidence rate for ESRD. MEASUREMENTS: Morning urine albumin-creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR). Incident cases of ESRD were identified through the US Renal Data System. RESULTS: A family history of ESRD was reported by 11.1% of participants. Mean eGFRs for those with and without a family history of ESRD were 87.5 ± 22.2 (SD) and 86.5 ± 19.3 mL/min/1.73 m(2), respectively (P = 0.05) and the respective geometric mean ACRs were 12.2 and 9.7 mg/g (P < 0.001). ESRD incidence rates for those with and without a family history of ESRD were 244.3 and 106.1/100,000 person-years, respectively. After adjusting for age, sex, and race, the ESRD HR for those with versus those without a family history of ESRD was 2.13 (95% CI, 1.18-3.83). Adjustment for comorbid conditions and socioeconomic status attenuated this association (HR, 1.82; 95% CI, 1.00-3.28), and further adjustment for baseline eGFR and ACR completely attenuated the association between family history of ESRD and incident ESRD (HR, 1.12; 95% CI, 0.69-1.80). LIMITATIONS: The report of a family history of ESRD was not validated. CONCLUSION: Family history of ESRD is common in older Americans and the increased risk of ESRD associated with a family history reflects lower GFR, higher albuminuria, and comorbid conditions.

Patterns of Hemodialysis Catheter Dysfunction Defined According to National Kidney Foundation Guidelines As Blood Flow <300 mL/min.

Blood flow rate (BFR) <300 mL/min commonly is used to define hemodialysis catheter dysfunction and the need for interventions to prevent complications. The objective of this study was to describe patterns of unplanned BFR <300 mL/min during catheter hemodialysis using data from DaVita dialysis facilities and the United States Renal Data System. Patients were included if they received at least eight weeks of hemodialysis exclusively through a catheter between 08/04 and 12/06, and catheter hemodialysis was the first treatment modality following diagnosis of end-stage renal disease (first access), or it immediately followed at least one 30-day period of dialysis exclusively through a fistula or graft (replacement access). Actual BFR <300 mL/min despite a planned BFR ≥300 mL/min defined catheter dysfunction during each dialysis session. There were 3,364 patients, 268,363 catheter dialysis sessions, and 19,118 (7.1%) sessions with catheter dysfunction. Almost two-thirds of patients had ≥1 catheter dysfunction session, and 30% had ≥1 catheter dysfunction session per month. Patients with catheter as a replacement access had a higher rate of catheter dysfunction than those with a catheter as first access (hazard ratio: 1.13; P = 0.04). Catheter dysfunction affects almost one-third of catheter dialysis patients each month and two-thirds overall.

Albuminuria and racial disparities in the risk for ESRD.

The causes of the increased risk for ESRD among African Americans are not completely understood. Here, we examined whether higher levels of urinary albumin excretion among African Americans contributes to this disparity. We analyzed data from 27,911 participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study who had urinary albumin-to-creatinine ratio (ACR) and estimated GFR (eGFR) measured at baseline. We identified incident cases of ESRD through linkage with the United States Renal Data System. At baseline, African Americans were less likely to have an eGFR <60 ml/min per 1.73 m(2) but more likely to have an ACR ≥ 30 mg/g. The incidence rates of ESRD among African Americans and whites were 204 and 58.6 cases per 100,000 person-years, respectively. After adjustment for age and gender, African Americans had a fourfold greater risk for developing ESRD (HR 4.0; 95% CI 2.8 to 5.9) compared with whites. Additional adjustment for either eGFR or ACR reduced the risk associated with African-American race to 2.3-fold (95% CI 1.5 to 3.3) or 1.8-fold (95% CI 1.2 to 2.7), respectively. Adjustment for both ACR and eGFR reduced the race-associated risk to 1.6-fold (95% CI 1.1 to 2.4). Finally, in a model that further adjusted for both eGFR and ACR, hypertension, diabetes, family income, and educational status, African-American race associated with a nonsignificant 1.4-fold (95% CI 0.9 to 2.3) higher risk for ESRD. In conclusion, the increased prevalence of albuminuria may be an important contributor to the higher risk for ESRD experienced by African Americans.

Kidney function, albuminuria, and all-cause mortality in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) study.

BACKGROUND: Chronic kidney disease and albuminuria are associated with increased risk of all-cause mortality. STUDY DESIGN: Prospective observational cohort study. SETTING & PARTICIPANTS: 17,393 participants (mean age, 64.3 ± 9.6 years) in the REGARDS (Reasons for Geographic and Racial Differences in Stroke) Study. PREDICTOR: Estimated glomerular filtration rate (eGFR), urinary albumin-creatinine ratio (ACR). OUTCOME: All-cause mortality (710 deaths); median duration of follow-up, 3.6 years. MEASUREMENTS & ANALYSIS: Categories of eGFR (90 to <120, 60 to <90, 45 to <60, 30 to <45, and 15 to <30 mL/min/1.73 m(2)) and urinary ACR (<10 mg/g or normal, 10 to <30 mg/g or high normal, 30 to 300 mg/g or high, and >300 mg/g or very high). Cox proportional hazards models were adjusted for demographic factors, cardiovascular covariates, and hemoglobin level. RESULTS: The background all-cause mortality rate for participants with normal ACR, eGFR of 90 to <120 mL/min/1.73 m(2), and no coronary heart disease was 4.3 deaths/1,000 person-years. Higher ACR was associated with an increased multivariable-adjusted HR for all-cause mortality within each eGFR category. Decreased eGFR was associated with a higher adjusted HR for all-cause mortality for participants with high-normal (P = 0.01) and high (P < 0.001) ACRs, but not those with normal or very high ACRs. LIMITATIONS: Only 1 laboratory assessment for serum creatinine and ACR was available. CONCLUSIONS: Increased albuminuria was an independent risk factor for all-cause mortality. Decreased eGFR was associated with increased mortality risk in those with high-normal and high ACRs. The mortality rate was low in the normal-ACR group and increased in the very-high-ACR group, but did not vary with eGFR in these groups.

Associations of dietary fat with albuminuria and kidney dysfunction.

BACKGROUND: Diet represents a potentially important target for intervention in nephropathy, yet data on this topic are scarce. OBJECTIVES: The objective was to investigate associations between dietary fats and early kidney disease. DESIGN: We examined cross-sectional associations between dietary fats and the presence of high albuminuria (an established independent predictor of kidney function decline, cardiovascular disease, and mortality) or estimated glomerular filtration rate (eGFR) <60 mL ⋅ min(-1) ⋅ 1.73 m(-2) at baseline in 19,256 participants of the REGARDS (Reasons for Geographic and Racial Differences in Stroke) study, an ongoing cohort study in US adults aged ≥45 y at time of enrollment. We used logistic regression to assess associations between quintiles of total fat and subtypes of dietary fat (saturated, monounsaturated, polyunsaturated, and trans fat) and presence of high albuminuria or eGFR <60 mL ⋅ min(-1) ⋅ 1.73 m(-2). RESULTS: After multivariable adjustment, only saturated fat intake was significantly associated with high albuminuria [for quintile 5 compared with quintile 1, odds ratio (OR): 1.33; 95% CI: 1.07, 1.66; P for trend = 0.04]. No significant associations between any type of fat and eGFR <60 mL · min(-1) · 1.73 m(-2) were observed. ORs between the highest quintile of saturated fat and eGFR <60 mL · min(-1) · 1.73 m(-2) varied by race with a borderline significant interaction term (ORs: 1.24 in whites compared with 0.74 in blacks; P for interaction = 0.05) in multivariable-adjusted models, but no other associations were significantly modified by race or diabetes status. CONCLUSION: Higher saturated fat intake is significantly associated with the presence of high albuminuria, but neither total nor other subtypes of dietary fat are associated with high albuminuria or eGFR <60 mL · min(-1) · 1.73 m(-2).

Hemoglobin concentration and cognitive impairment in the renal REasons for Geographic And Racial Differences in Stroke (REGARDS) Study.

BACKGROUND: There is growing interest in determining the degree of anemia, which is clinically significant. The goal of this study was to determine the association between hemoglobin concentration and cognitive impairment in a large sample of U.S. adults. METHODS: We used cross-sectional data from 19,701 adults participating in the REasons for Geographic And Racial Differences in Stroke study. Cognitive impairment was defined as a score of 4 or less on the six-item screener. Hemoglobin was analyzed in 1 g/dL increments relative to the World Health Organization (WHO) threshold (<13 g/dL for men and <12 g/dL for women). RESULTS: The mean hemoglobin concentration was 13.7 ± 1.5 g/dL. The prevalence of cognitive impairment increased from 4.3% among individuals with a hemoglobin >3 g/dL above the WHO threshold to 16.8% for those with a hemoglobin ≥2 g/dL below the WHO threshold. After adjustment for demographics, chronic health conditions, health status, and inflammation, the association between reduced hemoglobin and cognitive impairment was attenuated and no longer significant, including among those with hemoglobin ≥2 g/dL below the WHO threshold (odds ratio 1.39, 95% confidence interval = 0.94-2.04). A test for linear trend was of borderline significance (p value = .06). For 94% of the sample within 2 g/dL of the WHO threshold, there was no relationship between hemoglobin concentration and the odds of cognitive impairment. The associations did not differ by sex and race. CONCLUSIONS: Within a large sample of community-dwelling adults, there was no significant association between hemoglobin concentration and cognitive impairment after multivariable adjustment.

Poverty and racial disparities in kidney disease: the REGARDS study.

UNLABELLED: There are pronounced disparities among black compared to white Americans for risk of end-stage renal disease. This study examines whether similar relationships exist between poverty and racial disparities in chronic kidney disease (CKD) prevalence. METHODS: We studied 22,538 participants in the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort study. We defined individual poverty as family income below USD 15,000 and a neighborhood as poor if 25% or more of the households were below the federal poverty level. RESULTS: As the estimated glomerular filtration rate (GFR) declined from 50-59 to 10-19 ml/min/ 1.73 m2, the black:white odds ratio (OR) for impaired kidney function increased from 0.74 (95% CI 0.66, 0.84) to 2.96 (95% CI 1.96, 5.57). Controlling for individual income below poverty, community poverty, demographic and comorbid characteristics attenuated the black:white prevalence to an OR of 0.65 (95% CI 0.57, 0.74) among individuals with a GFR of 59-50 ml/min/1.73 m2 and an OR of 2.21 (95% CI 1.25, 3.93) among individuals with a GFR between 10 and 19 ml/min/ 1.73 m2. CONCLUSION: Household, but not community poverty, was independently associated with CKD and attenuated but did not fully account for differences in CKD prevalence between whites and blacks.

Exploration of anaemia as a progression factor in African Americans with cardiovascular disease.

BACKGROUND: Despite the higher incidence of end-stage renal disease (ESRD) among African Americans, whites in the USA have a higher prevalence of chronic kidney disease. This may be due, in part, to faster progression to ESRD among African Americans. Anaemia is associated with a risk of kidney disease progression and is more prevalent among African Americans. The purpose of this study is to determine if anaemia is associated with progression to ESRD differently according to race. METHODS: A retrospective cohort study of Cooperative Cardiovascular Project data for 87 693 Medicare beneficiaries >or=65 years old and ESRD free admitted to 4047 hospitals with acute myocardial infarction between February 1994 and June 1995 was conducted. Follow-up was collected through June 2004 for ESRD and mortality. RESULTS: Among 87 693 patients, 7.0% were African Americans and 50.1% females. African Americans had a higher prevalence of anaemia than whites (40.2% versus 26.7%, respectively; P < 0.001). Lower haematocrit was associated with higher ESRD rates after adjustment, and the association of haematocrit with ESRD did not vary according to race (P = 0.19). This association was strongest at the lowest baseline kidney function (GFR <15) with hazard ratios increasing 7-fold as haematocrit decreased from >or= 42% to <28%. CONCLUSIONS: In a nationally representative sample of patients with cardiovascular disease, anaemia was associated equally among African Americans and whites with an increased risk of ESRD.

Obesity, end-stage renal disease, and survival in an elderly cohort with cardiovascular disease.

Obesity is highly prevalent in African Americans and is associated with increased risk of End-Stage Renal Disease (ESRD) and death. It is not known if the effect of obesity is similar among blacks and whites. The aim of this study is to examine racial differences in the association of obesity with ESRD and survival in elderly patients (age >65). Data were obtained for 74,167 Medicare patients with acute myocardial infarction (AMI) between February 1994 and July 1995. BMI was calculated as weight (kg) divided by height (m(2)). We evaluated the association of BMI class with ESRD incidence and death using multivariable Cox proportional hazards models, testing for race-BMI interactions. Compared to whites, African Americans had higher BMI (26.9 vs. 26.0, P < 0.0001) and estimated glomerular filtration rate (72.4 ml/min/1.73 m(2) vs. 66.6 ml/min/1.73 m(2), P < 0.0001). Crude ESRD rates increased with increasing obesity among whites but not among blacks. However, after adjusting for age, sex, and other comorbidities, obesity was not associated with increased ESRD rate among blacks or whites and the interaction between race and BMI was not significant. Furthermore, for both races, patients classified as overweight, class 1 obese, or class 2 obese had similar, significantly better survival abilities compared to normal weight patients and the race BMI interaction was not significant. In conclusion, obesity does not increase risk of ESRD among black or white elderly subjects with cardiovascular disease (CVD). However, both obese blacks and whites, in this population, experience a survival benefit. Further studies need to explore this obesity paradox.

Correlates of anemia in American blacks and whites: the REGARDS Renal Ancillary Study.

For unclear reasons, anemia is more common in American blacks than whites. The authors evaluated anemia prevalence (using World Health Organization criteria) among 19,836 blacks and whites recruited in 2003-2007 for the REasons for Geographic And Racial Differences in Stroke Renal Ancillary study and characterized anemia by 3 anemia-associated conditions (chronic kidney disease, inflammation, and microcytosis). They used multivariable models to assess potential causes of race differences in anemia. Anemia was 3.3-fold more common in blacks than whites, with little attenuation after adjusting for demographic variables, socioeconomic factors, and comorbid conditions. Increasing age, residence in the US southeast, lower income, vascular disease, diabetes, hypertension, and never smoking were associated with anemia. Age, diabetes, and vascular disease were stronger correlates of anemia among whites than blacks (P < 0.05). Among those with anemia, chronic kidney disease was less common among blacks than whites (22% vs. 34%), whereas inflammation (18% vs. 14%) and microcytosis (22% vs. 11%) were more common. In this large, geographically diverse cohort, anemia was 3-fold more common in blacks than whites with different characteristics and correlates. Race differences in anemia prevalence were not explained by the factors studied. Future research into the causes and consequences of anemia in different racial groups is needed.

Chronic kidney disease is often unrecognized among patients with coronary heart disease: The REGARDS Cohort Study.

INTRODUCTION: Individuals with kidney disease are at increased risk for coronary heart disease (CHD) and CHD is associated with an increased prevalence of chronic kidney disease (CKD). Awareness of CKD may potentially influence diagnostic decisions, life-style changes and pharmacologic interventions targeted at modifiable CHD risk factors. We describe here the degree to which persons with CHD are aware of their CKD. METHODS: The Reasons for Geographical and Racial Difference in Stroke (REGARDS) cohort study, a population-based sample of US residents aged 45 and older. We included in our analyses 28,112 REGARDS participants recruited as of June 2007. We estimated GFR (eGFR) using the MDRD equation, defined CKD as a GFR <60 ml/min/1.73 m(2), and ascertained awareness of chronic kidney disease and coronary heart disease through self-report. We used the odds ratio to compare the association between awareness of kidney disease, as measured by GFR <60 ml/min/1.73 m(2), among individuals with and without self-reported CHD by both the presence of CKD and the severity of impaired kidney function. RESULTS: Coronary heart disease was reported by 3,803 (14.1%) of subjects, and 11.3% of subjects had CKD by eGFR. Among all individuals with a GFR <60 ml/min/ 1.73 m(2), 9.6% reported having been told by a physician that they had kidney disease. Among those with CHD and CKD, 5.0% were aware of their CKD compared to 2.0% in those without CHD [OR (95% CI) = 2.57 (2.08, 3.28)]. This difference persisted after controlling for the level of kidney function [aOR (95% CI) = 1.87 (1.43, 2.41)]. CONCLUSION: There was a high prevalence of CKD and a low prevalence of awareness of kidney disease among older adults in the US population with or without coronary heart disease. These findings support recent recommendations that patients with cardiovascular disease be systematically screened for and educated about CKD.

Racial differences in the competing risks of mortality and ESRD after acute myocardial infarction.

BACKGROUND: The prevalence of earlier stage chronic kidney disease is lower for African Americans than whites in the United States. This is counterintuitive given the known 4-fold greater incidence of end-stage renal disease (ESRD) in African Americans. We describe racial differences in the rate of progression to ESRD and address the competing risk of mortality. STUDY DESIGN: Retrospective analysis of Cooperative Cardiovascular Project data. SETTING & PARTICIPANTS: 127,736 Medicare beneficiaries 65 years and older admitted to 4,545 hospitals with acute myocardial infarction between February 1994 and June 1995, with follow-up data for ESRD and mortality through June 2004. PREDICTORS: African American versus white race, estimated glomerular filtration rate (eGFR), and their interaction; other characteristics at hospital admission. OUTCOMES & MEASUREMENTS: Time to ESRD using Cox proportional hazards models. RESULTS: Mean age was 77.1 years, with 8,278 African Americans (6.5%) and 49.9% women. Mean baseline eGFRs were 61.4 +/- 31.4 and 57.0 +/- 25.6 mL/min/1.73 m(2) (P < 0.001) for African Americans and whites, respectively. Of 2,161 patients (1.7%) progressing to ESRD (incidence, 3.75/1,000 person-years), 14.9% were African American. The adjusted hazard ratio for ESRD (African Americans versus whites) was 1.90 (95% confidence interval, 1.78 to 2.03); African Americans were at significantly increased risk of incident ESRD at each baseline eGFR stage (P for interaction < 0.001). Racial differences in incident ESRD were not accounted for by differences in mortality. LIMITATIONS: Retrospective analysis, residual bias from unmeasured factors, baseline eGFR determined from serum creatinine levels at the time of acute hospitalization. CONCLUSIONS: Within a nationally representative sample of Medicare patients with acute myocardial infarction, African Americans had an increased 10-year risk of ESRD regardless of baseline kidney function that was not accounted for by differences in pre-ESRD mortality.

Long-term risk of mortality and end-stage renal disease among the elderly after small increases in serum creatinine level during hospitalization for acute myocardial infarction.

BACKGROUND: Although small changes in creatinine level during hospitalization have been associated with risk of short-term mortality, associations with posthospitalization end-stage renal disease (ESRD) and long-term mortality are unknown. We assessed the relationship between change in serum creatinine levels up to 3.0 mg/dL and death and ESRD among elderly survivors of hospitalization for acute myocardial infarction. METHODS: Retrospective cohort study of a nationally representative sample of Medicare beneficiaries admitted with acute myocardial infarction to nonfederal US hospitals between February 1994 and July 1995. Outcomes were mortality and ESRD through June 2004. RESULTS: The 87 094 eligible patients admitted to 4473 hospitals had a mean age of 77.1 years; for the 43.2% with some creatinine increase, quartiles of increase were 0.1, 0.2, 0.3 to 0.5, and 0.6 to 3.0 mg/dL. Incidence of ESRD and mortality ranged from 2.3 and 139.1 cases per 1000 person-years, respectively, among patients with no increase to 20.0 and 274.9 cases per 1000 person-years in the highest quartile of creatinine increase. Compared with patients without creatinine increase, adjusted hazard ratios by quartile of increase were 1.45, 1.97, 2.36, and 3.26 for ESRD and 1.14, 1.16, 1.26, and 1.39 for mortality, with no 95% confidence intervals overlapping 1.0 for either end point. CONCLUSION: In a nationally representative sample of elderly patients discharged after hospitalization for acute myocardial infarction, small changes in serum creatinine level during hospitalization were associated with an independent higher risk of ESRD and death.

Racial differences in the prevalence of chronic kidney disease among participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Cohort Study.

The racial disparity in the incidence of ESRD exemplified by the three- to four-fold excess risk among black compared with white individuals in the United States is not reflected in the prevalence of less severe degrees of impaired kidney function among black compared with white individuals. The four-variable Modification of Diet in Renal Disease study equation was used to evaluate the black-to-white prevalence of impaired kidney function with increasing severity of impairment among participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, a nationally representative, population-based cohort of individuals who are 45 yr and older. An estimated GFR (eGFR)<60 ml/min per 1.73 m2 was present in 43.3% of the 20,667 REGARDS participants and was slightly less prevalent among black than white patients (33.7 versus 49.9%; prevalence odds ratio 0.51; 95% confidence interval [CI] 0.48 to 0.54). The lower prevalence among black patients was not uniform as eGFR declined. After controlling for other patient characteristics, the black-to-white odds ratio was 0.42 (95% CI 0.40 to 0.46) at an eGFR of 50 to 59 ml/min per 1.73 m2 and increased to 1.73 (95% CI 1.02 to 2.94) at an eGFR of 10 to 19 ml/min per 1.73 m2. The disparity in prevalence of impaired kidney function among white compared with black patients reversed as the severity of impaired kidney function increased. Factors that are responsible for the increasing prevalence of severely impaired kidney function among black patients remain to be determined.

Survival advantage of black patients with kidney disease after acute myocardial infarction.

Black individuals have a disproportionate incidence of ESRD when compared with white individuals, and among patients with ESRD, black patients experience better survival. The aim of this analysis is to assess, in a nationally representative sample of patients with cardiovascular disease, ethnic differences in survival among predialysis patients with kidney disease. A retrospective cohort analysis was conducted of Cooperative Cardiovascular Project data of Medicare patients who were aged > 65 yr and admitted for incident acute myocardial infarction and had 3 yr of mortality follow-up. Cox regression models and Kaplan Meier estimates were performed to examine differences in survival between black and white patients stratified by severity of kidney disease. Of 57,942 patients, 7.3% were black. Black patients were younger and more likely to be female and were less likely to have decreased kidney function. A significant interaction between race and kidney function existed with respect to mortality among patients who survived to discharge. The adjusted hazard ratios for death, black compared with white patients, were 1.00 (95% confidence interval 0.90 to 1.11) among patients with a GFR > or = 60 ml/min per 1.73 m2 and decreased monotonically among patients with lower GFR to 0.79 (95% confidence interval 0.61 to 0.97) among patients with a GFR 15 to 29 ml/min per 1.73 m2. Among patients with incident acute myocardial infarction, black patients with more severe kidney disease, when compared with their white counterparts, experience better survival. Further investigation into the reasons for ethnic differences in survival and progression of kidney disease is warranted.

Delay in time to receipt of thrombolytic medication among Medicare patients with kidney disease.

BACKGROUND: Patients with kidney disease and acute myocardial infarction (AMI) receive standard therapy, including thrombolytic medication, less frequently than patients with normal kidney function. Our goal is to identify potential differences in thrombolytic medication delays and thrombolytic-associated bleeding events by severity of kidney disease. METHODS: This is a retrospective cohort analysis of Cooperative Cardiovascular Project data for all Medicare patients with AMI from 4,601 hospitals. Outcome measures included time to administration of thrombolytic medication censored at 6 hours and bleeding events. RESULTS: Of 109,169 patients (mean age, 77.4 years; 50.6% women), 13.9% received thrombolysis therapy. Average time to thrombolytic therapy was longer in patients with worse kidney function. Adjusted hazard ratios for minutes to thrombolytic therapy were 0.83 (95% confidence interval [CI], 0.79 to 0.87) for patients with a serum creatinine level of 1.6 to 2.0 mg/dL (141 to 177 micromol/L) and 0.58 (95% CI, 0.53 to 0.63) for patients with a creatinine level greater than 2.0 mg/dL (>177 micromol/L) or on dialysis therapy compared with those with normal kidney function. Odds ratios for bleeding events in patients administered thrombolytics versus those who were not decreased with worse kidney function: adjusted odds ratios, 2.28 (95% CI, 2.16 to 2.42) in patients with normal kidney function and 1.84 (95% CI, 1.09 to 3.10) in dialysis patients. CONCLUSION: Patients with worse kidney function experienced treatment delays, but were not at greater risk for thrombolysis-associated excess bleeding events. Physician concerns of thrombolytic-associated bleeding may not be sufficient reason to delay the administration of thrombolytic medication.