Red cell distribution width in heart failure: prediction of clinical events and relationship with markers of ineffective erythropoiesis, inflammation, renal function, and nutritional state

Expansion of the red cell distribution width and evolving iron deficiency as predictors of poor outcome in chronic heart failure

BACKGROUND

An elevated red cell distribution width (RDW) and iron deficiency (ID) at baseline predict enhanced mortality in chronic heart failure (CHF), but little is known about the prognostic implications of their temporal trends. We sought to determine the survival implications of temporal changes in RDW and evolving ID in patients with CHF.

METHODS

The relation between red cell indices on first consultation and over time with mortality in 274 stable patients with systolic CHF was analysed. The combination of a rising RDW with a falling mean cell volume (MCV) over time defined evolving ID.

RESULTS

Over a median 12 month period, 51% and 23% of patients had a rise in RDW and evolving ID, respectively. After a median follow-up of 27 months, 60 (22%) patients died. A rising RDW predicted enhanced all-cause mortality (unadjusted HR for 1% per week rise 9.27, 95% CI 3.58 to 24.00, P<0.0001) independently and incrementally to baseline RDW, with an absolute increase >0.02% per week optimally predictive. Evolving ID also related to higher rates of mortality (HR 2.78, 95% CI 1.64 to 4.73, P<0.001) and was prognostically worse than a rising RDW alone (P<0.005). Patients with evolving ID who maintained their Hb levels over time had a 2-fold greater risk of death than those whose Hb levels declined without evolving ID.

CONCLUSIONS

An expanding RDW and evolving iron deficiency over time predict an amplified risk of death in CHF and should be utilised for risk stratification and/or therapeutically targeted to potentially improve outcomes.

[Red cell distribution width and mortality risk in acute heart failure patients]

BACKGROUND AND OBJECTIVE

Red cell distribution width (RDW) is a quantitative measure of the variability in size of erythrocytes, and it is used for the differential diagnosis of anemia. Recent reports have suggested that high RDW could play a role for risk stratification in patients with chronic heart failure. However, the prognostic role of RDW in unselected population with acute heart failure (AHF), after a thoroughly multivariate adjustment, has not been well established. The aim of this study was to establish the association between RDW and long-term mortality in patients admitted for AHF.

PATIENTS AND METHOD

We analyzed 1,190 consecutive patients admitted for AHF in our center. RDW measurement was performed on admission. RDW values were stratified into quartiles (Q) and the association of RDW with total mortality was assessed using Cox regression.

RESULTS

After a median follow-up of 15 months (interquartile range 3-33 months) 458 (38%) deaths were identified. There was a progressive increase in mortality rates from Q1 to Q4: 1.34, 1.82, 2.56 and 3.53 per 10 patients-year of follow-up (for Q1, Q2, Q3 and Q4 respectively, P for trend <.001). In the multivariate analysis, this association remained independent for patients in Q3 (15-16%) and Q4 (>16%) versus Q1 (≤14%), hazard ratio (HR): 1.66, 95% confidence interval (95% CI) 1.24-2.22, P<.01, HR: 1.80, 95% CI 1.33-2.43, p<.01, respectively, in a model adjusted for established prognostic markers in AHF.

CONCLUSION

In patients with AHF, higher RDW values were associated with increased long-term mortality.

Relation of coronary collateral circulation with red cell distribution width in patients with non-ST elevation myocardial infarction

OBJECTIVES

We aimed to investigate the relationship between red cell distribution width (RDW) value and coronary collateral circulation (CCC) in patients with non-ST elevation myocardial infarction (NSTEMI).

METHODS

The study population consisted of 322 consecutive patients with NSTEMI. The patients were classified into impaired CCC (group 1, Rentrop grades 0-1) or good CCC (group 2, Rentrop grades 2-3). Baseline RDW was measured as part of the automated complete blood count.

RESULTS

The RDW values were significantly higher in patients with impaired CCC than in those with good CCC (17.2 ± 2.3 vs 14.5 ± 2.5, P < .001). In multivariate logistic regression analysis, RDW (odds ratio: 1.52, 95% confidence interval: 1.30-1.78, P < .001), baseline creatine kinase MB (CK-MB), and absence of preinfarction angina were found to be the independent predictors of impaired CCC. In receiver-operating characteristic curve analysis, the RDW value >15.5 yielded an area under curve value of 0.783, with 77% sensitivity and 73% specificity.

CONCLUSIONS

Our study results demonstrated that, high RDW, high CK-MB, and absence of preinfarction angina were found to be independent predictors of impaired CCC.

Prognostic value of red cell distribution width in patients with pulmonary embolism

Elevated red blood cell distribution width (RDW) has been associated with adverse outcomes of heart failure and pulmonary hypertension. A total of 702 consecutive patients with acute pulmonary embolism (PE) were evaluated. There was a graded increase in mortality rate with RDW quartiles of 5.8% in quartile I (≤13.6), 9.7% in quartile II (13.7%-14.5%), 13.1% in quartile III (14.6%-16.3%), and 20% in quartile IV (>16.3%; P < .001). Patients who died had higher baseline RDW values (16.1% [11.7-28.3] vs 14.5% [10.7-32.5]; P < .001). The optimal cutoff value of RDW for predicting in-hospital mortality was ≥15%. The area under the curve of mortality for RDW was 0.649 (confidence interval [CI]: 0.584-0.715); the negative predictive value was 93%. In multivariable regression analysis, RDW remained associated with an increased odds of death (odds ratio: 1.2, 95% CI: 1.1-1.4). High RDW level was an independent predictor of short-term mortality in PE. The RDW levels may provide a potential marker to predict outcome in patients with PE.

Red cell distribution width and mean platelet volume in amyloidosis

We aimed to determine whether red cell distribution width (RDW) and mean platelet volume (MPV) values differ between patients with reactive amyloid A (AA) amyloidosis due to chronic inflammatory disease and in healthy participants. In this study, 33 patients with AA amyloidosis and 40 age- and sex-matched healthy controls were enrolled. Erythrocyte sedimentation rate (ESR), RDW, platelet count (PLT), and MPV levels were retrospectively obtained from our computerized patient database. We found RDW, ESR, and PLT levels to be significantly higher in patients with AA amyloidosis compared with the controls (P < .0001). Mean platelet volume was significantly lower in patients with amyloidosis (P < .0001). Inflammatory diseases such as AA amyloidosis may demonstrate low MPV and high RDW levels.

Relation between red cell distribution width and clinical outcome after surgery for congenital heart disease in children

Recent studies have reported a strong association between increased red cell distribution width (RDW) and the risk of adverse outcomes for adults with heart failure. This study investigated the association between preoperative RDW and postoperative clinical outcomes for children with cardiac disease. The relation between preoperative RDW and the length of postoperative stay was tested with 688 consecutive children undergoing surgery for congenital heart disease (CHD). The RDW was significantly higher in patients who died during the postoperative hospital stay (mean, 18.34 ± 4.69 vs 16.12 ± 2.84; p = 0.004). The risk of postoperative death was five times higher for patients with an RDW of 16% or more. In the general study population, RDW correlated with the intensive care unit (ICU) stay (p < 0.0001) and with the total hospital stay in the local population (p < 0.0001). The correlation between RDW and ICU stay was stronger for patients with acyanotic CHD (p < 0.0001) than for those with cyanotic CHD (p = 0.0007), and for the subpopulation of patients with acyanotic CHD and normal hemoglobin level (p < 0.0001) than for anemic patients with acyanotic CHD (p = 0.025). Preoperative RDW is a strong predictor of an adverse outcome in children undergoing surgery for CHD, especially in nonanemic patients, for whom it reflects an underlying inflammatory stress.

Red blood cell distribution width and its relation to cardiac function and biomarkers in a prospective hospital cohort referred for echocardiography

BACKGROUND

Red blood cell distribution width (RDW), a measure of anisocytosis, is a prognostic biomarker for heart failure (HF). However it is still unclear how RDW is associated with heart function and established cardiac biomarkers.

METHODS AND RESULTS

In a prospective hospital cohort of 296 patients referred for echocardiography because of suspected HF, blood sampling and clinical examination were performed within 24h after echocardiography. The patients were divided into four HF groups, including one group where the HF diagnosis was uncertain (gray zone). In the patients the mean age was 70 ± 11 years, 44% with systolic HF (SHF), 18% with heart failure with normal ejection fraction (HFNEF), 17% with gray zone and 21% without HF (non-HF). RDW was higher among patients with SHF and HFNEF, compared with gray zone and non-HF patients. The distribution of different variables over the RDW quartiles showed an inverse correlation between RDW levels and LVEF and a positive correlation between RDW and NT-proBNP levels. Further analysis with stepwise multiple linear regression demonstrated that NT-proBNP levels, but not LVEF, were independently correlated with RDW.

CONCLUSION

In patients referred for echocardiography because of suspected HF, RDW levels were higher in patients with SHF and HFNEF. Moreover, NT-proBNP levels were independently linked with elevated RDW.

Red cell distribution width and outcome in patients with septic shock

INTRODUCTION

Red cell distribution width (RDW) is reflective of systemic inflammation. The objective of this study was to investigate the association between RDW (on day 1 of development of septic shock) and mortality.

METHODS

A total of 279 patients with septic shock were included. We categorized the patients into quintiles based on RDW as follows: <13.5%, 13.5% to 15.5%, 15.6% to 17.5%, 17.5% to 19.4%, and >19.4%.

RESULTS

Red cell distribution width was a strong predictor of hospital mortality with a significant risk gradient across RDW quintiles after multivariable adjustment: RDW 13.5% to 15.5% (odds ratio [OR], 4.6; 95% confidence interval [CI], 1.0-23.4; P = .06); RDW 15.6% to 17.5% (OR, 8.0; 95% CI, 1.5-41.6; P = .01); RDW 17.6% to 19.4% (OR, 25.3; 95% CI, 4.3-149.2; P < .001); and RDW >19.4% (OR, 12.3; 95% CI, 2.1-73.3; P = .006), all relative to patients with RDW <13.5%. Similar significant robust associations were present for intensive care unit mortality. Estimating the receiver-operating characteristic area under the curve (AUC) showed that RDW has very good discriminative power for hospital mortality (AUC = 0.74). The AUC was 0.69 for Acute Physiologic and Chronic Health Evaluation II (APACHE II) and 0.69 for sequential organ failure assessment (SOFA). When adding RDW to APACHE II, the AUC increased from 0.69 to 0.77.

CONCLUSIONS

Red cell distribution width on day 1 of septic shock is a robust predictor of mortality. The RDW is inexpensive and commonly measured. The RDW fared better than either APACHE II or SOFA, and the sum of RDW and APACHE II was a stronger predictor of mortality than either one alone.

Red blood cell distribution width is associated with poor clinical outcome in acute cerebral infarction

Increased red blood cell distribution width (RDW), which is a marker of anisocytosis, is associated with mortality and cardiovascular events in the general population and in patients with heart failure or coronary heart disease. We investigated whether RDW in acute cerebral infarction is predictive of functional outcome and mortality. A total of 847 consecutive patients with first-ever acute cerebral infarction who presented to the emergency department within seven days of symptom onset were enrolled in this study. We investigated the association of RDW with poor functional outcome (modified Rankin Scale >2) and all-cause mortality at three months, as well as survival time for one year after stroke onset. Multivariate logistic regression revealed that higher RDW was independently associated with poor functional outcome (adjusted odds ratio [OR], 1.222 per 1% increment in RDW, 95% confidence interval [CI] 1.059-1.409, p=0.006) and all-cause death (adjusted OR, 1.395 per 1% increment in RDW, 95% CI 1.168-1.665, p<0.001) at three months after stroke onset. RDW was an independent predictor of survival in multivariate Cox-proportional regression model (adjusted hazard ratio, 1.328 per 1% increment in RDW, 95%CI 1.178-1.498, p<0.001). The addition of RDW to a survival model significantly increased predictability for survival across the entire follow-up period (weighted average of the area-under the curves, 0.858 vs. 0.841, p<0.05). In conclusion, higher RDW measured in cases of acute stage cerebral infarction was associated with poor functional outcome and mortality. RDW may be used as a biomarker for the prediction of long-term outcomes in patients with acute cerebral infarction.

Red blood cell distribution width, multimorbidity, and the risk of death in hospitalized older patients

We aimed to assess the association between red blood cell distribution width (RDW) and mortality in patients enrolled by a Geriatric Department. One hundred twenty-two patients were followed up during 5 years. The primary end point was all-cause mortality, and hazard ratios were estimated using a Cox proportional hazard model. Higher RDW values were strongly associated with an increased risk of death. Survival curves across RDW quartiles were statistically different according to the log-rank test (p = 0.017). The first quartile presented higher probability of survival compared to the last one. The gradient from lower to higher risk across quartiles was clear both in the 5-year mortality risk and in the mortality rate per 100 person-years, which ranged from 18.9 to 42.6. However, in the Cox regression model after adjusting for age, severity, and other factors, excess risk was only observed in the highest RDW quartile, with a hazard ratio of 2.24 (CI(95%) 1.13-4.42) vs the first quartile. RDW is a good predictor of mortality in hospitalized older adults beyond those with cardiovascular risk factors, and it could serve as an integrative measure of multiple clinical and subclinical processes simultaneously occurring in complex patients.

Clinical usefulness of measuring red blood cell distribution width in patients with hepatitis B

Background

Red blood cell distribution width (RDW), an automated measure of red blood cell size heterogeneity (e.g., anisocytosis) that is largely overlooked, is a newly recognized risk marker in patients with cardiovascular diseases, but its role in persistent viral infection has not been well-defined. The present study was designed to investigate the association between RDW values and different disease states in hepatitis B virus (HBV)-infected patients. In addition, we analyzed whether RDW is associated with mortality in the HBV-infected patients.

Methodology/Principal Findings

One hundred and twenty-three patients, including 16 with acute hepatitis B (AHB), 61 with chronic hepatitis B (CHB), and 46 with chronic severe hepatitis B (CSHB), and 48 healthy controls were enrolled. In all subjects, a blood sample was collected at admission to examine liver function, renal function, international normalized ratio and routine hematological testing. All patients were followed up for at least 4 months. A total of 10 clinical chemistry, hematology, and biochemical variables were analyzed for possible association with outcomes by using Cox proportional hazards and multiple regression models. RDW values at admission in patients with CSHB (18.30±3.11%, P<0.001), CHB (16.37±2.43%, P<0.001) and AHB (14.38±1.72%, P<0.05) were significantly higher than those in healthy controls (13.03±1.33%). Increased RDW values were clinically associated with severe liver disease and increased 3-month mortality rate. Multivariate analysis demonstrated that RDW values and the model for end-stage liver disease score were independent predictors for mortality (both P<0.001).

Conclusion

RDW values are significantly increased in patients with hepatitis B and associated with its severity. Moreover, RDW values are an independent predicting factor for the 3-month mortality rate in patients with hepatitis B.

Red cell distribution width and risk of peripheral artery disease: Analysis of National Health and Nutrition Examination Survey 1999–2004

Red cell distribution width (RDW) is an independent predictor of the 10-year estimated risk of coronary heart disease (CHD) events. However, RDW’s association with peripheral artery disease (PAD) – a CHD risk equivalent – has not been evaluated to date. In this cross-sectional study, we examined 6950 participants of the National Health and Nutrition Examination Survey, 1999–2004. PAD was defined as an ankle–brachial index below 0.9 ( n = 618). RDW was divided into quartiles (Q) (Q1: ≤ 12.2; Q2: 12.3–12.5; Q3: 12.6–13.0; Q4: ≥ 13.1) and PAD risk was compared across these quartiles using adjusted multivariate logistic regression. A graded increase in prevalent PAD with increasing RDW quartiles was observed (4.2% in Q1 vs 13.9% in Q4; test of trend p < 0.001). Risk of PAD was significantly higher (odds ratio (OR) 1.19, 95% confidence interval (CI): 1.06–1.34; p = 0.003) after adjusting for age, sex, race, body mass index, hypertension, hyperlipidemia, diabetes, smoking, estimated glomerular filtration rate, C-reactive protein, hemoglobin, mean corpuscular volume, and nutritional factors (folate, iron and vitamin B12) deficiencies with each unit (0.1) increase in RDW. Upon receiver-operating characteristics analysis, the predictive accuracy of the American College of Cardiology / American Heart Association (ACC/AHA)-defined PAD screening criteria (for a high-risk population) was 0.657 at best, but improved significantly (0.727) after addition of RDW ( p < 0.0001). In conclusion, higher levels of RDW are independently associated with a higher risk of PAD and can significantly improve the risk prediction beyond that estimated by ACC/AHA-defined PAD screening criteria.

Red cell distribution width improves the simplified acute physiology score for risk prediction in unselected critically ill patients

Introduction

Recently, red cell distribution width (RDW), a measure of erythrocyte size variability, has been shown to be a prognostic marker in critical illness. The aim of this study was to investigate whether adding RDW has the potential to improve the prognostic performance of the simplified acute physiology score (SAPS) to predict short- and long-term mortality in an independent, large, and unselected population of intensive care unit (ICU) patients.

Methods

This observational cohort study includes 17,922 ICU patients with available RDW measurements from different types of ICUs. We modeled the association between RDW and mortality by using multivariable logistic regression, adjusting for demographic factors, comorbidities, hematocrit, and severity of illness by using the SAPS.

Results

ICU-, in-hospital-, and 1-year mortality rates in the 17,922 included patients were 7.6% (95% CI, 7.2 to 8.0), 11.2% (95% CI, 10.8 to 11.7), and 25.4% (95% CI, 24.8 to 26.1). RDW was significantly associated with in-hospital mortality (OR per 1% increase in RDW (95%CI)) (1.14 (1.08 to 1.19), P < 0.0001), ICU mortality (1.10 (1.06 to 1.15), P < 0.0001), and 1-year mortality (1.20 (95% CI, 1.14 to 1.26); P < 0.001). Adding RDW to SAPS significantly improved the AUC from 0.746 to 0.774 (P < 0.001) for in-hospital mortality and 0.793 to 0.805 (P < 0.001) for ICU mortality. Significant improvements in classification of SAPS were confirmed in reclassification analyses. Subgroups demonstrated robust results for gender, age categories, SAPS categories, anemia, hematocrit categories, and renal failure.

Conclusions

RDW is a promising independent short- and long-term prognostic marker in ICU patients and significantly improves risk stratification of SAPS. Further research is needed the better to understand the pathophysiology underlying these effects.

A high red blood cell distribution width predicts failure of arteriovenous fistula

In hemodialysis patients, a native arteriovenous fistula (AVF) is the preferred form of permanent vascular access. Despite recent improvements, vascular access dysfunction remains an important cause of morbidity in these patients. In this prospective observational cohort study, we evaluated potential risk factors for native AVF dysfunction. We included 68 patients with chronic renal disease stage 5 eligible for AVF construction at the Department of General and Vascular Surgery, Central Clinical Hospital Ministry of Internal Affairs, Warsaw, Poland. Patient characteristics and biochemical parameters associated with increased risk for AVF failure were identified using Cox proportional hazards models. Vessel biopsies were analyzed for inflammatory cells and potential associations with biochemical parameters. In multivariable analysis, independent predictors of AVF dysfunction were the number of white blood cells (hazard ratio [HR] 1.67; 95% confidence interval [CI] 1.24 to 2.25; p<0.001), monocyte number (HR 0.02; 95% CI 0.00 to 0.21; p = 0.001), and red blood cell distribution width (RDW) (HR 1.44; 95% CI 1.17 to 1.78; p<0.001). RDW was the only significant factor in receiver operating characteristic curve analysis (area under the curve 0.644; CI 0.51 to 0.76; p = 0.046). RDW>16.2% was associated with a significantly reduced AVF patency frequency 24 months after surgery. Immunohistochemical analysis revealed CD45-positive cells in the artery/vein of 39% of patients and CD68-positive cells in 37%. Patients with CD68-positive cells in the vessels had significantly higher white blood cell count. We conclude that RDW, a readily available laboratory value, is a novel prognostic marker for AVF failure. Further studies are warranted to establish the mechanistic link between high RDW and AVF failure.

Relation between changes in red cell distribution width and clinical outcomes in acute decompensated heart failure

BACKGROUND

Increased red blood cell distribution (RDW) has been associated with adverse outcomes in patients with heart failure. We studied the association between baseline RDW and changes in RDW during hospital course with clinical outcomes in acute decompensated heart failure (ADHF) patients.

METHODS AND RESULTS

We prospectively studied 614 patients with ADHF. Baseline RDW and RDW change during hospital course were determined. The relationship between RDW and clinical outcomes after hospital discharge was tested using Cox regression models, adjusting for clinical characteristics, echocardiographic findings and brain natriuretic peptide levels. During follow up (1 year), 286 patients (46.6%) died and 84 were readmitted for ADHF (13.7%). Median RDW was significantly higher among patients who died compared to patients who survived (15.6% interquartile range [14.5 to 17.1] vs. 14.9% mg/L interquartile range [14.1 to 16.1], P<0.0001). Compared with patients in the 1st RDW quartile, the adjusted hazard ratio [HR] for death or rehospitalization was 1.9 [95% CI 1.3-2.6] in patients in the 4th quartile. Changes in RDW during hospitalization were strongly associated with changes in mortality risk. Compared with patients with persistent normal RDW (<14.5%), the adjusted HR for mortality was 1.9 [95% CI 1.1-3.1] for patients in whom RDW increased above 14.5% during hospital course, similar to patients with persistent elevation of RDW (HR was 1.7, 95% CI 1.2-2.3).

CONCLUSION

In patients hospitalized with ADHF, RDW is a strong independent predictor of greater morbidity and mortality. An increase in RDW during hospitalization also portends adverse clinical outcome.

Association between red cell distribution width and disease activity in patients with inflammatory bowel disease

BACKGROUND

Recent studies have suggested that a higher red blood cell distribution width (RDW) is associated with disease activity in patients with inflammatory bowel disease (IBD). However, the RDW in IBD patients without anemia has not been investigated.

AIM

This study aimed to determine whether or not RDW could be used for the assessment of disease activity in IBD patients with and without anemia.

METHODS

The serum C-reactive protein (CRP) level, erythrocyte sedimentation rate (ESR), hemoglobin concentration, platelet and white blood cell counts, and RDW were assessed in 221 IBD patients, comprised of 120 patients with ulcerative colitis (UC) and 101 patients with Crohn's disease (CD). Disease activity was determined for UC and CD with the Mayo score and the Crohn's disease activity index, respectively.

RESULTS

The CRP level, ESR, hemoglobin concentration, hematocrit, and RDW increased according to disease activity in patients with and without anemia (all P < 0.05). Multivariate analysis demonstrated that RDW was the best independent indicator for predicting disease activity in CD patients without anemia [odd ratios (OR), 1.702; 95% confidence interval (CI), 1.185-2.445; P = 0.004] and UC patients without anemia (OR, 4.921; 95% CI, 2.281-10.615; P < 0.001). Also, ROC curve analysis showed the RDW to be the most significant indicator of non-anemic active IBD [area under curve (AUC) in CD, 0.852, P < 0.001; AUC in UC, 0.827, P < 0.001].

CONCLUSION

The association between increased RDW and active IBD was evident in IBD patients with and without anemia.

Red blood cell distribution width predicts early mortality in patients with acute dyspnea

BACKGROUND

Red blood cell distribution width (RDW) has been shown to predict clinical outcomes in cardiovascular diseases. We studied whether RDW is useful to predict early mortality in patients with acute dyspnea at an emergency department (ED).

METHODS

We retrospectively analyzed 907 patients with acute dyspnea who visited the ED from January 2009 to May 2009. Primary outcome was 30-day mortality.

RESULTS

Acute decompensated heart failure (29.9%) was the most common adjudicated discharge diagnosis followed by cancer (14.8%) and pneumonia (12.5%). There was a stepwise increase of 30-day mortality risk from lowest (RDW<12.9%) to highest (RDW>14.3%) RDW tertiles (1.4% vs. 8.3% vs. 18.3%; log-rank P<0.001). In multivariate Cox hazard analysis, RDW was an independent predictor of 30-day mortality after adjusting for other risk factors (HR 1.23; 95% CI 1.11-1.36; P<0.001). Adding RDW to conventional clinical predictors significantly improved prediction for 30-day mortality as measured by the area under the ROC curve (AUC, from 0.873 to 0.885; P=0.023) and the net reclassification improvement (NRI=14.1%; P<0.001)/integrated discrimination improvement (IDI=0.038; P=0.006).

CONCLUSIONS

Our findings suggest that RDW measured at ED is an independent and additive predictor of early mortality in patients with acute dyspnea.

Red cell distribution width and mortality in newly hospitalized patients

OBJECTIVE

Previous studies suggest that red cell distribution width, a measure of erythrocyte size variability, may predict long-term mortality, particularly in cardiovascular disease. Less research has focused on the prognostic utility of red cell distribution width in an acutely hospitalized population.

METHODS

We performed a secondary analysis of prospectively collected data on 74,784 consecutive hospitalized adults with red cell distribution width measured on admission. The primary outcome of interest was in-hospital mortality; a secondary outcome was unplanned transfer to the intensive care unit. We calculated multivariable logistic models adjusted for age, gender, race, and comorbid conditions.

RESULTS

The overall in-hospital mortality rate was 1.3% (95% confidence interval [CI], 1.2-1.4). As red cell distribution width increased, so did mortality, from 0.2% (lowest red cell distribution width decile) to 4.4% (highest red cell distribution width decile). Unadjusted red cell distribution width significantly discriminated between hospital survivors and nonsurvivors (area under the curve 0.74). In multivariate analyses, for every 1% increment in red cell distribution width at the time of admission, the odds for in-hospital mortality increased by 24% (odds ratio 1.24; 95% CI, 1.20-1.27); findings were robust across comorbidity subgroups. The rate of unplanned intensive care unit transfer was 7.0% (95% CI, 6.8-7.2) and in unadjusted analyses increased more than 2-fold from 4.5% in the lowest to 11.6% in the highest red cell distribution width decile. This relationship was significantly confounded but remained significant in multivariate analysis (odds ratio 1.04 per 1% red cell distribution width increment; 95% CI, 1.03-1.06).

CONCLUSION

Red cell distribution width strongly and independently predicted in-hospital mortality in this large cohort of hospitalized patients. It also was associated with acute decompensation among patients on the general ward, but to a lesser degree. The mechanisms underlying these findings are unknown.

Usefulness of admission red cell distribution width as a predictor of early mortality in patients with acute pulmonary embolism

Red cell distribution width (RDW) is strongly associated with prognosis in cardiopulmonary disorders such as coronary artery disease, acute myocardial infarction, acute and chronic heart failure, and pulmonary hypertension. However, its prognostic significance in acute pulmonary embolism (PE) is unknown. The aim of this study was to investigate the relation between admission RDW and early mortality in patients with acute PE. One hundred sixty-five patients with confirmed acute PE were included. Patients with previous treatment for anemia, malignancy, or chronic liver disease, those with dialysis treatment for chronic renal failure, and those who received erythrocyte suspension for any reason were excluded. A total of 136 consecutive patients with acute PE were evaluated prospectively. According to receiver-operating characteristic curve analysis, the optimal cut-off value of RDW to predict early mortality was >14.6%, with 95.2% sensitivity and 53% specificity. Patients were categorized prospectively as having unchanged (group 1) or increased (group 2) RDW on the basis of a cut-off value of 14.6%. The mean age of patients was 63 ± 15 years. The mean follow-up duration was 11 ± 7 days, and 21 patients died. Among these 21 patients, 1 (1.6%) was in group 1 and 20 (27%) were in group 2 (p <0.001). Increased RDW >14.6% on admission, age, presence of shock, heart rate, oxygen saturation, and creatinine level were found to have prognostic significance in univariate Cox proportional-hazards analysis. Only increased RDW >14.6% on admission (hazard ratio 15.465, p = 0.012) and the presence of shock (hazard ratio 9.354, p <0.001) remained associated with increased risk for acute PE-related early mortality in a multivariate Cox proportional-hazards model. In conclusion, high RDW was associated with worse hemodynamic parameters, and RDW seems to aid in the risk stratification of patients with acute PE.

Association between red blood cell distribution width and macrovascular and microvascular complications in diabetes

AIMS/HYPOTHESIS

Red blood cell distribution width (RDW) has been reported to be a risk marker of morbidity and mortality for cardiovascular disease in various study populations. However, no studies have investigated the relationship between RDW and diabetes complications. We therefore evaluated RDW as a marker of macrovascular and microvascular complications in a nationally representative sample of the adult diabetes population in the USA.

METHODS

A cross-sectional study was performed using the nationwide 1988 to 1994 data set from the Third National Health and Nutrition Examination Survey. The association between RDW quartiles and macrovascular and microvascular complications was evaluated in 2,497 non-pregnant adults aged 20 years and older and affected by diabetes. Logistic regression modelling was used to adjust for potential confounding.

RESULTS

Compared with the lowest RDW quartile, higher RDW values (3rd and 4th quartiles) were associated with increased adjusted odds of any vascular complication (OR 4th quartile 2.06 [95% CI 1.11, 3.83]), myocardial infarction (OR 4th quartile 2.45 [95% CI 1.13, 5.28]), heart failure (OR 4th quartile 4.40 [95% CI 1.99, 9.72]), stroke (OR 4th quartile 2.56 [95% CI 1.21, 5.42]) and nephropathy (OR 4th quartile 2.33 [95% CI 1.42, 3.82]). The odds of developing diabetic retinopathy were not significantly increased across RDW quartiles.

CONCLUSIONS/INTERPRETATION

Higher RDW values are associated with increased odds of developing cardiovascular disease and nephropathy in a nationally representative sample of USA adults with diabetes. RDW may be an important clinical marker of vascular complications in diabetes and one that is independent of traditional risk factors and disease duration.

Red cell distribution width and all-cause mortality in critically ill patients

OBJECTIVE

Red cell distribution width is a predictor of mortality in the general population. The prevalence of increased red cell distribution width and its significance in the intensive care unit are unknown. The objective of this study was to investigate the association between red cell distribution width at the initiation of critical care and all cause mortality.

DESIGN

Multicenter observational study.

SETTING

Two tertiary academic hospitals in Boston, MA.

PATIENTS

A total of 51,413 patients, aged ≥ 18 yrs, who received critical care between 1997 and 2007.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The exposure of interest was red cell distribution width as a predictor of mortality in the general population. The prevalence of increased red cell distribution width and its significance in the intensive care unit are unknown and categorized a priori in quintiles as ≤ 13.3%, 13.3% to 14.0%, 14.0% to 14.7%, 14.7% to 15.8%, and >15.8%. Logistic regression examined death by days 30, 90, and 365 postcritical care initiation, inhospital mortality, and bloodstream infection. Adjusted odds ratios were estimated by multivariable logistic regression models. Adjustment included age, sex, race, Deyo-Charlson index, coronary artery bypass grafting, myocardial infarction, congestive heart failure, hematocrit, white blood cell count, mean corpuscular volume, blood urea nitrogen, red blood cell transfusion, sepsis, and creatinine. Red cell distribution width was a particularly strong predictor of all-cause mortality 30 days after critical care initiation with a significant risk gradient across red cell distribution width quintiles after multivariable adjustment: red cell distribution width 13.3% to 14.0% (odds ratio [OR], 1.19; 95% confidence interval [CI], 1.08-1.30; p <.001); red cell distribution width 14.0% to 14.7% (OR, 1.28; 95% CI, 1.16-1.42; p <.001); red cell distribution width 14.7% to 15.8% (OR, 1.69; 95% CI, 1.52-1.86; p <.001); red cell distribution width >15.8% (OR, 2.61; 95% CI, 2.37-2.86; p <.001), all relative to patients with red cell distribution width ≤ 13.3%. Similar significant robust associations postmultivariable adjustments are seen with death by days 90 and 365 postcritical care initiation as well as inhospital mortality. In a subanalysis of patients with blood cultures drawn (n = 18,525), red cell distribution width at critical care initiation was associated with the risk of bloodstream infection and remained significant after multivariable adjustment. The adjusted risk of bloodstream infection was 1.40- and 1.44-fold higher in patients with red cell distribution width values in the 14.7% to 15.8% and >15.8% quintiles, respectively, compared with those with red cell distribution width ≤ 13.3%. Estimating the receiver operating characteristic area under the curve shows that red cell distribution width has moderate discriminative power for 30-day mortality (area under the curve = 0.67).

CONCLUSION

Red cell distribution width is a robust predictor of the risk of all-cause patient mortality and bloodstream infection in the critically ill. Red cell distribution width is commonly measured, inexpensive, and widely available and may reflect overall inflammation, oxidative stress, or arterial underfilling in the critically ill.

Red blood cell distribution width is an independent predictor of mortality in acute kidney injury patients treated with continuous renal replacement therapy

BACKGROUND

A potential independent association was recently demonstrated between high red blood cell distribution width (RDW) and the risk of all-cause mortality in patients with cardiovascular disease, although the mechanism remains unclear. However, there have been no reports on the relationship between RDW and mortality in acute kidney injury (AKI) patients treated with continuous renal replacement therapy (CRRT). In this study, we assessed whether RDW was associated with mortality in AKI patients on CRRT treatment in the intensive care unit (ICU).

METHODS

We enrolled 470 patients with AKI who were treated with CRRT at the Yonsei University Medical Center ICU from August 2007 to September 2009 in this study. We performed a retrospective analysis of demographic, biochemical parameters and patient outcomes. Following CRRT treatment, 28-day all-cause mortality was evaluated.

RESULTS

At the initiation of CRRT treatment, RDW level was significantly correlated with white blood cell count, hemoglobin (Hb) and total cholesterol. Patients with high RDW levels exhibited significantly higher 28-day mortality rates than patients with low RDW levels (P < 0.01). Baseline RDW level, Sequential Organ Failure Assessment (SOFA) score, low mean arterial pressure (MAP) and low cholesterol levels were independent risk factors for mortality. In multivariate Cox proportional hazard analyses, RDW at CRRT initiation was an independent predictor for 28-day all-cause mortality after adjusting for age, gender, MAP, Hb, albumin, total cholesterol, C-reactive protein and SOFA score.

CONCLUSION

Our study demonstrates that RDW could be an additive predictor for all-cause mortality in AKI patients on CRRT treatment in the ICU.

Red Cell Distribution Width Does Not Predict Stroke Severity or Functional Outcome

Introduction

Red cell distribution width was recently identified as a predictor of cardiovascular and all-cause mortality in patients with previous stroke. Red cell distribution width is also higher in patients with stroke compared with those without. However, there are no data on the association of red cell distribution width, assessed during the acute phase of ischemic stroke, with stroke severity and functional outcome. In the present study, we sought to investigate this relationship and ascertain the main determinants of red cell distribution width in this population.

Methods

We used data from the Acute Stroke Registry and Analysis of Lausanne for patients between January 2003 and December 2008. Red cell distribution width was generated at admission by the Sysmex XE-2100 automated cell counter from ethylene diamine tetraacetic acid blood samples stored at room temperature until measurement. An χ2-test was performed to compare frequencies of categorical variables between different red cell distribution width quartiles, and one-way analysis of variance for continuous variables. The effect of red cell distribution width on severity and functional outcome was investigated in univariate and multivariate robust regression analysis. Level of significance was set at 95%.

Results

There were 1504 patients (72±15·76 years, 43·9% females) included in the analysis. Red cell distribution width was significantly associated to NIHSS ( β-value=0·24, P=0·01) and functional outcome (odds ratio=10·73 for poor outcome, P<0·001) at univariate analysis but not multivariate. Prehospital Rankin score ( β=0·19, P<0·001), serum creatinine ( β=0·008, P<0·001), hemoglobin ( β=−0·009, P<0·001), mean platelet volume ( β=0·09, P<0·05), age ( β=0·02, P<0·001), low ejection fraction ( β=0·66, P<0·001) and antihypertensive treatment ( β=0·32, P<0·001) were independent determinants of red cell distribution width.

Conclusions

Red cell distribution width, assessed during the early phase of acute ischemic stroke, does not predict severity or functional outcome.

Determinants of red cell distribution width (RDW) in cardiorenal patients: RDW is not related to erythropoietin resistance

BACKGROUND

Studies have shown that red cell distribution width (RDW) is related to outcome in chronic heart failure (CHF). The pathophysiological process is unknown. We studied the relationship between RDW and erythropoietin (EPO) resistance, and related factors such as erythropoietic activity, functional iron availability and hepcidin.

METHODS AND RESULTS

In the Mechanisms of Erythropoietin Action in the Cardiorenal Syndrome (EPOCARES) study, which investigates the role of EPO in 54 iron-supplemented anemic patients with CHF and chronic kidney disease (CKD) (n = 35 treated with 50 IU/kg/wk Epopoetin beta, n = 19 control), RDW was not associated with EPO resistance. We defined EPO resistance by EPO levels (r = 0.12, P = .42), the observed/predicted log EPO ratio (r = 0.12, P = .42), the increase in reticulocytes after 2 weeks of EPO treatment (r = -0.18, P = .31), and the increase of hemoglobin after 6 months of EPO treatment (r = 0.26, P = .35). However, RDW was negatively correlated with functional iron availability (reticulocyte hemoglobin content, r = -0.48, P < .001, and transferrin saturation, r = -0.39, P = .005) and positively with erythropoietic activity (soluble transferrin receptor, r = 0.48, P < .001, immature reticulocyte fraction, r = 0.36, P = .01) and positively with interleukin-6 (r = 0.48, P < .001). No correlation existed between hepcidin-25 and RDW.

CONCLUSIONS

EPO resistance was not associated with RDW. RDW was associated with functional iron availability, erythropoietic activity, and interleukin-6 in anemic patients with CHF and CKD.

Usefulness of red cell distribution width to predict mortality in patients with peripheral artery disease

Increased red blood cell distribution width (RDW), a marker of anisocytosis, has been associated with adverse outcomes in multiple settings. Whether RDW is predictive of mortality in patients with peripheral artery disease (PAD) is unknown. We studied 13,039 consecutive outpatients (69.5 ± 12.0 years of age, 60.9% men, 97.6% white) with PAD identified by noninvasive lower-extremity arterial testing at the Mayo Clinic from January 1997 through December 2007, with follow-up through September 2009. We defined PAD as a low (≤ 0.9) or high (≥ 1.4) ankle-brachial index (ABI). Cardiovascular risk factors and co-morbidities were ascertained using electronic medical record-based algorithms. RDW was obtained from the complete blood cell count drawn around the time of arterial evaluation. Mortality was ascertained using the Mayo electronic medical record and Accurint databases. Association of RDW with all-cause mortality was analyzed by multivariable Cox proportional hazards regression. During a median follow-up of 5.5 years, 4,039 (31.0%) deaths occurred (28.7% in low and 38.9% in high ABI subsets). After adjustment for age, gender, cardiovascular risk factors, and co-morbidities, patients in the highest quartile of RDW (> 14.5%) had a 66% greater risk of mortality compared to the lowest quartile (< 12.8%, p < 0.0001); a 1% increment in RDW was associated with a 10% greater risk of all-cause mortality (hazard ratio 1.10, 95% confidence interval 1.08 to 1.12, p < 0.0001). The adjusted hazard ratio was similar in the low (1.10, 1.08 to 1.12) and high (1.09, 1.06 to 1.12) ABI subsets. In conclusion, RDW, a routinely available measurement, is an independent prognostic marker in patients with PAD.

Red cell distribution width as a novel predictor of mortality in ICU patients

BACJGROUND: the red cell distribution width (RDW) in ICU patients has never been investigated.

METHODS

a total of 602 consecutive patients were prospectively enrolled. We collected each patient's base-line characteristics including the Acute Physiology and Chronic Health Evaluation II (APACHE-II) score, RDW, and C-reactive protein (CRP). The primary outcome for this analysis was ICU mortality, and secondary outcome was the total length of stay in hospital (TLSH). Potential predictors were analyzed for possible association with outcomes.

RESULTS

there was a significantly graded increase in APACHE-II score (tertile I = 10.7 ± 6.5 versus tertile II = 13.3 ± 6.2 versus tertile III = 15.8 ± 7.2; all P < 0.001) and ICU mortality rate (tertile I = 11.2% versus tertile II = 18.8% versus tertile III = 33.8%; all P < 0.001) across increasing of RDW tertile. As compared with APACHE-II score, combination of RDW and APACHE-II score increased the area under the curve (AUC) for predicting ICU mortality from 0.832 ± 0.020 to 0.885 ± 0.017 (P < 0.05). Multivariate analysis demonstrated that RDW, APACHE-II score, and CRP were independent predictors of ICU mortality (P < 0.05). RDW was also independently associated with TLSH in patients alive (P < 0.05).

CONCLUSION

we found a graded independent relation between higher RDW and adverse outcomes in ICU patients. RDW has the potentially clinical utility to predict outcome in ICU patients.

Relationship between red cell distribution width and short-term outcomes in acute coronary syndrome in a Chinese population

OBJECTIVE

This study was undertaken to determine the relationship between red cell distribution width (RDW) and short-term outcomes in acute coronary syndrome (ACS) in a Chinese population.

METHODS AND PATIENTS

A total of 1,654 patients with ACS on admission were divided into four groups according to quartiles of baseline RDW. The relationships between RDW and one-month cardiac mortality as well as heart failure and recurrent infarction were assessed.

RESULTS

Higher RDW values were associated with increased one-month cardiac mortality (quartile 1: 0.2%; quartile 2: 0.6%; quartile 3: 3.3%; quartile 4: 8.1%; p<0.001) and one-month heart failure and recurrent infarction (quartile 1: 2.1%; quartile 2: 2.7%; quartile 3: 3.6%; quartile 4: 15.2%; p<0.001). Logistic regression analysis revealed that RDW independently predicted for cardiac mortality (OR: 2.116, 95% CI: 1.427-3.137, p<0.001) and heart failure and recurrent infarction (OR: 2.134, 95% CI: 1.602-2.844, p<0.001) during a one-month follow-up in patients with ACS.

CONCLUSION

The present study indicates that elevated RDW could predict an increased risk of short-term adverse outcomes in patients with ACS.

Red cell distribution width and mortality in predominantly African-American population with decompensated heart failure

INTRODUCTION

Red-cell distribution width (RDW) has been identified as a novel prognostic marker in heart failure patients. However, evidence is limited for its predictive value in the setting of patients hospitalized with decompensated heart failure (DHF) and no data are available for African Americans (AA).

METHODS AND RESULTS

Data that included baseline characteristics, laboratory findings, and discharge medications were collected retrospectively on a total of 789 patients with DHF (mean age 62.7 ± 15.1 years, 50% males and 80% AA), admitted to an urban medical center between January 2007 and August 2007, 145 (18.38%) died during median follow-up of 573 days. Unadjusted and adjusted Cox-proportional hazard models were used to analyze predictive value of discharge RDW on mortality. There was a significant negative association between RDW and statin use, blood hemoglobin levels and mean corpuscular volume (MCV); whereas serum creatinine and blood urea nitrogen (BUN) increased with increasing RDW. A statistically significant graded increase in all-cause mortality with higher RDW quartiles (lowest vs highest quartile), independent of hemoglobin and creatinine levels, was found for all patients (adjusted hazard ratio [HR] 3.21; 95% confidence interval [CI]: 1.77-5.83, P < .05) for AAs (adjusted HR 2.92; 95% CI: 1.50-5.71, P < .05) and for non-AAs (adjusted HR-1.27, 95% CI: 1.03-1.55, P = 0.019; RDW evaluated as continuous variable).

CONCLUSION

Discharge RDW is an independent predictor of all-cause mortality in predominantly AA patients hospitalized with DHF. Further research is warranted to delineate underlying pathophysiological mechanisms including the association between statin use and RDW.

Red cell distribution width and risk of coronary heart disease events

Red cell distribution width (RDW) has emerged as a powerful predictor of all-cause mortality in variety of cardiovascular settings. However, no data are available associating RDW with coronary heart disease (CHD) risk in a healthy and nationally representative multiethnic population. A total of 7,556 participants of the National Health and Nutrition Examination Surveys 1999 to 2006 (age 41.5 ± 15.8 years, 60% women) were divided into 3 categories according to their 10-year Framingham risk of hard CHD events: <10% (n = 6,173, reference category), 10% to 20% (n = 1,093, intermediate-risk category), and >20% (n = 290, high-risk category). Unadjusted and adjusted multivariate logistic regression analyses were performed evaluating RDW as a predictor of CHD risk. Each unit increase (0.1) in RDW posed a statistically significant greater odds of being in the intermediate-risk category (odds ratio -1.35, 95% confidence interval 1.27 to 1.45, p <0.001) and high-risk category (odds ratio -1.38, 95% confidence interval 1.25 to 1.53, p <0.001) compared to the reference category, after adjusting for race, body mass index, estimated glomerular filtration rate, hemoglobin A1c, C-reactive protein, hemoglobin, and mean corpuscular volume. Additional adjustments with serum iron, vitamin B(12), and folic acid levels did not affect the association. Subsequently, we divided participants into 2 categories according to their anemia status (as defined by the World Health Organization) to evaluate its effect. An RDW level greater than the seventy-fifth percentile in both anemic and nonanemic participants was a significant predictor of greater CHD risk while RDW of the seventy-fifth percentile or less in anemic participants failed to predict CHD (compared to nonanemic participants with similar RDW as the reference category). In conclusion, a higher RDW appears to be a powerful independent predictor of future CHD risk.