In-hospital changes in the red blood cell distribution width and mortality in critically ill patients with heart failure

AIMS

A high red blood cell distribution width (RDW) at admission or discharge is associated with a worse prognosis in hospitalized patients with heart failure (HF), and the prognostic value of the in-hospital change in RDW (∆RDW) remains debatable.

METHODS AND RESULTS

We included 5514 patients with critical illness and HF from the MIMIC-IV database. The ΔRDW was calculated by the RDW at discharge minus that at admission. Clinical outcomes included all-cause mortality at 90 day, 180 day, and 1 year after discharge. The median age of the patients was 73.91 years, and 46.37% were women. Kaplan-Meier curve and Cox regression analyses were used to examine the association between the ΔRDW and all-cause mortality at different time points. A multivariable Cox proportional hazard model showed that the ΔRDW (per 1% increase) was independently associated with all-cause mortality at 90 day, 180 day, and 1 year after adjusting for confounding factors (hazard ratio [HR] = 1.17, 95% confidence interval [CI] = 1.13-1.21, P < 0.001; HR = 1.17, 95% CI = 1.14-1.20, P < 0.001; and HR = 1.18, 95% CI = 1.15-1.20, P < 0.001, respectively). Restricted cubic splines showed a non-linear relationship between the ΔRDW and the risk of clinical outcomes. High ΔRDW was associated with a high risk of mortality at different time points. A subgroup analysis showed that this positive association remained consistent in pre-specified subgroups.

CONCLUSIONS

Our study suggests that an increased RDW during hospitalization is independently associated with short- or long-term all-cause mortality in critical-ill patients with HF.

Effect of rScO2-Guided Blood Pressure Management on Postoperative Complications in Elderly Patients After Major Noncardiac Surgery: Protocol for a Randomized Controlled Trial

Background

Postoperative complications are common after major surgical procedures, leading to increased morbidity and mortality. Regional cerebral oxygen saturation (rScO2) reflects cerebral and global perfusion, and thus it can be used to guide hemodynamic management. We aim to explore the effect of rScO2-guided blood pressure management strategy on postoperative major complications in older adults who undergo major noncardiac surgery.

Methods

This randomized controlled clinical trial includes a total of 400 elderly patients receiving major noncardiac surgery and general anesthesia. Patients will be randomized (1:1) to one of two blood pressure management groups: a standard care group (targeting mean arterial pressure >65 mmHg or within 20% of baseline value), and a rScO2-guided group (absolute value of rScO2 >60% or decrease in rScO2 <10% of baseline). The primary outcome is the composite outcome of major complications (including infectious, respiratory, neurologic, cardiovascular, renal, thromboembolic gastrointestinal, and surgical complications) and deaths within the first 7 days after surgery. Secondary outcomes include the individual components of the primary outcome by day 7 after surgery and 30-day mortality. Data will be analyzed in the modified intention-to-treat population.

Discussion

This study will provide evidence for improving postoperative outcomes using the rScO2-guided blood pressure management among older adults who undergo major noncardiac surgery.

Trial Registration

Chinese Clinical Trial Registry (Identifier: ChiCTR2200060816).

Incorporating inflammatory biomarkers into a prognostic risk score in patients with non-ischemic heart failure: a machine learning approach

Objectives

Inflammation is involved in the mechanisms of non-ischemic heart failure (NIHF). We aimed to investigate the prognostic value of 21 inflammatory biomarkers and construct a biomarker risk score to improve risk prediction for patients with NIHF.

Methods

Patients diagnosed with NIHF without infection during hospitalization were included. The primary outcome was defined as all-cause mortality and heart transplantations. We used elastic net Cox regression with cross-validation to select inflammatory biomarkers and construct the best biomarker risk score model. Discrimination, calibration, and reclassification were evaluated to assess the predictive value of the biomarker risk score.

Results

Of 1,250 patients included (median age, 53 years, 31.9% women), 436 patients (34.9%) experienced the primary outcome during a median of 2.8 years of follow-up. The final biomarker risk score included high-sensitivity C-reactive protein-to-albumin ratio (CAR) and red blood cell distribution width-standard deviation (RDW-SD), both of which were 100% selected in 1,000 times cross-validation folds. Incorporating the biomarker risk score into the best basic model improved the discrimination (ΔC-index = 0.012, 95% CI 0.003-0.018) and reclassification (IDI, 2.3%, 95% CI 0.7%-4.9%; NRI, 17.3% 95% CI 6.4%-32.3%) in risk identification. In the cross-validation sets, the mean time-dependent AUC ranged from 0.670 to 0.724 for the biomarker risk score and 0.705 to 0.804 for the basic model with a biomarker risk score, from 1 to 8 years. In multivariable Cox regression, the biomarker risk score was independently associated with the outcome in patients with NIHF (HR 1.76, 95% CI 1.49-2.08, p < 0.001, per 1 score increase).

Conclusions

An inflammatory biomarker-derived risk score significantly improved prognosis prediction and risk stratification, providing potential individualized therapeutic targets for NIHF patients.

The Effects of Nordic Walking with Poles with an Integrated Resistance Shock Absorber on Red Blood Cell Distribution and Cardiorespiratory Efficiency in Postmenopausal Women-A Randomized Controlled Trial

BACKGROUND

Age-related reduction in exercise capacity is manifested by a rapid development of fatigue. Research confirmed the adverse prognostic value of red blood cell distribution width (RDW-CV), an independent factor in heart failure, coronary heart disease and myocardial infarction. Physical exercise improves and helps to maintain cardiorespiratory fitness. The aim of our study was to examine the impact of 8 weeks' Nordic walking training with classic poles (NW) and NW training with poles with an integrated resistance shock absorber (NW with RSA) on RDW-CV levels and to assess correlations between RDW-CV levels and cardiorespiratory performance in postmenopausal women.

METHODS

In this study, 32 postmenopausal women (NW-16, NW with RSA-16) participated in eight weeks of walking training. The mean age of women was 66.56 ± 4.23 year. and BMI 26.99 ± 3.86 kg/m². At the beginning and at the end of the study, spirometry and exercise tests were performed. Haematological parameters were determined in the venous blood.

RESULTS

Statistical analysis of differences in post-training changes in the parameters between the groups studied showed a significant difference in change in body weight (∆body weight) (p < 0.05; ES: 0.778), BMI (∆BMI) (p < 0.05; ES: 0.778), waist circumference (∆WC) (p < 0.05; ES: 1.225) and (∆RDW-SD) (p < 0.05; ES: 1.215). There were no changes in electrocardiographic and spirometric parameters.

CONCLUSIONS

Based on the findings from the present study, it can be assumed that endurance and resistance exercise can significantly reduce disease severity and mortality. A clinical analysis of RDW levels, together with other cardiological and biochemical parameters, can provide practical prognostic information relating to cardiovascular disease, mortality risk and treatment outcomes.

[Red cell distribution width as a predictor of impaired exercise capacity in patients with heart failure]

Aim    To test a hypothesis that increased values of red cell distribution width (RDW) in patients with chronic heart failure (CHF) can be related with low exercise tolerance.Material and methods    102 patients were evaluated who had CHF with mid-range and reduced left ventricular ejection fraction (LV EF) without anemia (72% men, mean age 66±10.2 years). Cardiopulmonary stress test (CPST), echocardiography, 6‑min walk test (6MWT), blood count, and measurements of N-terminal pro-brain natriuretic peptide (NT-pro-BNP) and serum iron were performed.Results    The average LV EF was 39±8.7 %; the peak oxygen consumption (VO2peak) was 13.7±4.8 ml /kg /min; and the median NT-pro-BNP was 595.3 pg /ml (Q1-3 1443-2401). RDW variables, including the RDW coefficient of variation (RDW-CV) and RDW standard deviation (RDW-SD), were not significantly related with serum iron or hemoglobin concentrations. A one-factor linear regression analysis showed a significant correlation of VO2peak with RDW-SD (р=0.039). A multivariate linear regression analysis with adjustments for LV EF, hemoglobin concentration, and age did not reveal any significant correlation of VO2peak with RDW variables. The distance covered in the 6MWT was significantly associated with RDW-CV both in the one-factor analysis and with adjustments for LV EF, hemoglobin and serum iron concentrations, and age.Conclusion    This study showed that high RDW values in CHF patients without anemia predicted low exercise tolerance regardless of the age, LV systolic function, and hemoglobin and serum iron concentrations. A 16% increase in RDW-CV significantly decreased the likelihood of covering a distance longer than 360 m during 6 min.

Red Blood Cell Distribution Width in Heart Failure: Pathophysiology, Prognostic Role, Controversies and Dilemmas

Red blood cell distribution width (RDW), an integral parameter of the complete blood count (CBC), has been traditionally used for the classification of several types of anemia. However, over the last decade RDW has been associated with outcome in patients with several cardiovascular diseases including heart failure. The role of RDW in acute, chronic and advanced heart failure is the focus of the present work. Several pathophysiological mechanisms of RDW’s increase in heart failure have been proposed (i.e., inflammation, oxidative stress, adrenergic stimulation, undernutrition, ineffective erythropoiesis, reduced iron mobilization, etc.); however, the exact mechanism remains unknown. Although high RDW values at admission and discharge have been associated with adverse prognosis in hospitalized heart failure patients, the prognostic role of in-hospital RDW changes (ΔRDW) remains debatable. RDW has been incorporated in recent heart failure prognostic models. Utilizing RDW as a treatment target in heart failure may be a promising area of research.

Prognostic value of red blood cell distribution width for mortality in patients with hypertrophic cardiomyopathy

BACKGROUND

Red blood cell distribution width (RDW) has emerged as a useful indicator for adverse outcomes in several cardiovascular diseases. The relation between RDW and the prognosis of hypertrophic cardiomyopathy (HCM) remains to be evaluated. We examined the relation between RDW and all-cause mortality and HCM-related death in a population of adult HCM patients.

METHODS

We performed clinical evaluation in 414 consecutive adult HCM patients (median age, 57.5 years; male, 54.8%).

RESULTS

During a median follow-up of 3.7 years, all-cause mortality and HCM-related death occurred in 75 (18.1%) and 50 (12.1%) patients, respectively. Based on the tertiles of baseline RDW, mortality increased with higher tertile. With the tertile 1 as reference, adjusted all-cause mortality hazard ratios (HRs) were 3.9 for the tertile 2 (95% confidence interval [CI]: 1.5-10.3) and 3.1 for the tertile 3 (95% CI: 1.1-8.2). Adjusted HCM-related death HRs were higher in the tertile 2 (HR: 5.5; 95% CI: 1.2-24.4) and tertile 3 (HR: 6.6; 95% CI: 1.5-29.0) compared with the tertile 1. Further smooth curve fitting exhibited a saturation effect after adjusting for confounders, and there were a two-stage change and an inflection point. Two-piecewise Cox model suggested mortality significantly increased with RDW level up to the inflection point (about 14.0% for both all-cause mortality and HCM-related death), and RDW was not associated with mortality after the point.

CONCLUSION

In adult HCM patients, we found increased RDW was a significant risk predictor for all-cause mortality and HCM-related death, and a saturation effect was observed.

Effect of rehabilitation on biologic and transcriptomic responses after hospital-acquired deconditioning: a prospective longitudinal feasibility study

PURPOSE

The objective of this study is to explore the transcriptomic and biologic variables characterizing the longitudinal rehabilitation intervention of patients with hospital-acquired deconditioning (HAD).

METHODS

This prospective clinical trial recruited HAD patients (n = 10) who spent ≥3 weeks hospitalized and then received inpatient rehabilitation. Functional improvement was measured using the Functional Independence Measure (FIM). Transcriptomic and biological variables were recorded at rehabilitation admission and 1, 2, 4, and 6 weeks post-admission. RNA sequencing studied the temporal changes of gene expression in leukocytes. Between-subject transcriptome comparisons were performed using principle component analysis. Within-subject changes in gene expression were analyzed using a gene ontology hierarchical clustering to identify common biological terms. Heart rate, weight, albumin, creatinine, and complete blood counts were analyzed.

RESULTS

Patients average age was 50.6 ± 7.2, FIM increased during inpatient rehabilitation (p = 0.01), weight increased (p = 0.01), lymphocytes decreased (p = 0.05), neutrophil increased (0.03) and red cell distribution width decreased (p = 0.05). The temporal profiles of gene expression revealed within-patient homogeneity and between-patients heterogeneity. The biological terms "bone morphogenesis" and "muscle cell development" were the most significantly enriched differentially expressed genes.

CONCLUSION

Transcriptomic and biologic markers paralleled the functional improvements of HAD patients during inpatient rehabilitation. Transcriptomic analyses were consistent with the cohort heterogeneity. Enrichment of the biological pathways bone morphogenesis and muscle cell development constituted evidence at the gene expression level of the effect of rehabilitation. Larger studies of various rehabilitation patient groups may increase gene expression profile homogeneity. Objective transcriptomic and biologic markers have the potential to improve the rehabilitation of HAD patients.IMPLICATIONS FOR REHABILITATIONNovel gene expression methods are increasingly being integrated into clinical practice and may apply to rehabilitation.Patients with hospital-acquired deconditioning (HAD) enriched gene expression of pathways targeted by inpatient rehabilitation such as bone morphogenesis and muscle cell development.The gene expression paralleled functional improvement of HAD patients.These data demonstrated the feasibility of molecular methods to identify markers of rehabilitation success in HAD patients.

Red Cell Distribution Width as a Predictor of Functional Outcome in Rehabilitation of Older Stroke Patients

BACKGROUND

Red cell distribution width (RDW) is a prognostic marker in vascular diseases. While increased RDW predicts mortality and outcomes after ischemic stroke, evidence regarding its prognostic significance in stroke rehabilitation is lacking. Thus, the present study investigated the relationship of RDW with stroke, orthopedic, and deconditioning rehabilitation outcomes.

METHODS

This prospective comparative study included three groups (stroke, orthopedic, and deconditioning) of older adult patients hospitalized for rehabilitation. The patients in each group were divided into two subgroups according to whether they had high (>14.5%) or normal (≤14.5%) RDW levels on admission. Functional outcome was assessed by total and motor FIM (Functional Independence Measure) score changes and efficiency at admission and on discharge.

RESULTS

Of the 234 eligible patients, 108 (46.2%) had high RDW. Of the 50 stroke rehabilitation patients, 13 (26%) had high RDW. FIM change and efficiency scores were significantly lower in patients with high RDW only in the stroke rehabilitation group. However, multiple linear regression analysis showed that high RDW was not independently associated with total and motor FIM gain or total and motor FIM efficiency.

CONCLUSION

High RDW levels on admission to rehabilitation were associated with poor rehabilitation outcome in stroke patients but were not an independent risk factor for rehabilitation outcomes.

Low-Volume High-Intensity Interval Versus Continuous Endurance Training: Effects on Hematological and Cardiorespiratory System Adaptations in Professional Canoe Polo Athletes

Sheykhlouvand, M, Gharaat, M, Khalili, E, Agha-Alinejad, H, Rahmaninia, F, and Arazi, H. Low-volume high-intensity interval versus continuous endurance training: effects on hematological and cardiorespiratory system adaptations in professional canoe polo athletes. J Strength Cond Res 32(7): 1852-1860, 2018-The aim of this study was to compare the effect of 2 paddling-based high-intensity interval training (HIIT) and continuous endurance training (CET) on hematological, immunological, and cardiorespiratory adaptations in professional canoe polo athletes. A total of 21 male canoe polo athletes were randomly divided into 1 of 3 groups (N = 7): (a) HIIT with variable intensity (VIHIIT) (6 × 60 seconds at 100, 110, 120, 130, 130, 130, 120, 110, 100% vV[Combining Dot Above]O2peak from first to ninth session, respectively, 1:3 work to recovery ratio); (b) HIIT with variable volume (VVHIIT) (6, 7, 8, 9, 9, 9, 8, 7, 6 repetitions/session from first to ninth session, respectively) × 60 seconds at lowest velocity that elicited V[Combining Dot Above]O2peak (vV[Combining Dot Above]O2peak), 1:3 work to recovery ratio); and (c) the CET group performed 3 times × 60 minutes paddling sessions (75% vV[Combining Dot Above]O2peak) per week for 3 weeks. Significant increases in V[Combining Dot Above]O2peak (ml·kg·min) (VIHIIT = 7.6%, VVHIIT = 6.7%), ventilation (V[Combining Dot Above]E) at V[Combining Dot Above]O2peak (VIHIIT = 11.5%, VVHIIT = 15.2%), respiratory frequency (Rf) at V[Combining Dot Above]O2peak (VVHIIT = 21.1%), V[Combining Dot Above]O2 at ventilatory threshold (VT) (VIHIIT = 10.5%, VVHIIT = 25.1%), V[Combining Dot Above]E at VT (VIHIIT = 12.4%, VVHIIT = 34.0%), tidal volume at VT (VIHIIT = 11.7%, VVHIIT = 33.3%), Rf at VT (VIHIIT = 9.7%), V[Combining Dot Above]E/V[Combining Dot Above]O2 at VT (VVHIIT = 13.1%), V[Combining Dot Above]O2/heart rate (HR) at VT (VIHIIT = 12.9%, VVHIIT = 21.4%), and V[Combining Dot Above]E/HR at VT (VIHIIT = 7.8%, VVHIIT = 27.2%) were seen compared with pretraining. Training interventions resulted in significant increases in mean platelet volume (VIHIIT = 2.7%, VVHIIT = 1.9%), mean corpuscular hemoglobin concentration (CET = 3.3%), and significant decrease in red blood cell distribution width (VVHIIT = -4.3), and cell numbers of lymphocyte (CET = -27.1) compared with pretraining. This study demonstrated that paddling-based HIIT enhances aerobic capacity and respiratory makers, without negatively affecting the immune system over 3 weeks.

Red blood cell distribution width as a potential predictor of survival of pulmonary arterial hypertension associated with primary Sjogren's syndrome: a retrospective cohort study

Pulmonary arterial hypertension (PAH) is a severe complication and leading cause of mortality in patients with primary Sjogren's syndrome (pSS). This study was to investigate the overall survival rates and the utility of red blood cell distribution width (RDW) as a potential prognostic factor of pSS-PAH. This cohort study retrospectively enrolled 55 patients with pSS-PAH who were followed up at the Department of Rheumatology of Peking Union Medical College Hospital (PUMCH) between August 2007 and May 2017. The patients were stratified according to the level of RDW (≤ 15.0 and > 15.0%). Baseline demographics, laboratory results, pulmonary function conditions, hemodynamic assessments, and treatment regimens were analyzed. Cox proportional hazards regression analysis was used to identify whether RDW level is a factor related to adverse outcome. A total of 55 patients were recruited, with an average age of 38.9 ± 9.3 years. Fifty-four were female (98.2%), and the average duration at the time of PAH diagnosis was 25.5 ± 33.2 months. Higher RDW levels were found in patients who deceased in follow-up (13.8 ± 2.6 vs 16.5 ± 1.6%, p = 0.003) and with higher NYHA classes (13.8 ± 1.8 vs 16.5 ± 2.9%, p < 0.001). Patients with RDW > 15% had a significantly worse overall survival than patients with RDW ≤ 15% (3-year survival rate 59.5 vs. 88.7% log-rank p = 0.015). Cox regression analysis identified RDW > 15% as a prognostic factor for adverse outcome (HR 1.786, 95% CI 1.137-2.803, p = 0.012). RDW can serve as a potential negative prognostic factor of pSS-PAH.

Red blood cell distribution width is a survival predictor beyond anemia and Nt-ProBNP in stable optimally medicated heart failure with reduced ejection fraction outpatients

BACKGROUND

RDW is an automatic value obtained with the blood count, and represents the erythrocytes dimension variation.

OBJECTIVE

To evaluate in optimally medicated outpatients with heart failure with reduced ejection fraction (HFrEF) the RDW prognostic value regarding survival in a multivariable model including anemia and Nt-ProBNP.

METHODS

233 consecutive outpatients, LVEF <40%, clinically stable were followed-up for 3-years in an HF Unit. End-point was all-cause death. The RDW categorized according to the tertiles (T1 = <13.9; T2 14-15.2; T3> = 15.3). Anemia classified according to the WHO criteria. Cox survival model adjusted for clinical profile, optimal therapeutic, renal function, Nt-ProBNP, etiology, atrial fibrillation, and anemia.

RESULTS

(1) The 3-years death rate was 33.5%, and increased with the RDW tertiles (17.3%; 25%; 61.1%; p < 0.001). (2) The ROC curve for death associated with RDW (AUC 0.73; p < 0.001); (3) The adjusted death risk increased with the tertiles (Hazard-ratio '[HR] = 1.61; IC 95% 1.09-2.39; p = 0.017). RDW> = 15.3 had greater adjusted death risk than T1 (HR = 2.18; 95% CI 0.99-4.8; p = 0.05) and T1+T2 (HR = 1.54; 95% CI 1.13-2.09; p = 0.006).

CONCLUSION

RDW determined in optimally medicated outpatients with HFrEF, during dry-state, is a strong, cheap, and independent predictor of long-term survival.

Effect of Exercise Training on Red Blood Cell Distribution Width as a Marker of Impaired Exercise Tolerance in Patients With Coronary Artery Disease

Red blood cell distribution width (RDW) can predict mortality in cardiovascular disease. However, the underlying mechanisms of the beneficial prognostic marker remain unknown. The purpose of this study was to investigate whether the RDW is related to impaired exercise tolerance and exercise training (ET) effect on RDW in patients with coronary artery disease (CAD).Seventy-eight patients who underwent ET by supervised bicycle ergometer during 3 weeks served as the ET group whereas 30 patients who did not undergo ET were the control group. Exercise stress test with cardiopulmonary analysis was performed in the ET group. Peak oxygen uptake (from 14.1 ± 4.0 to 15.1 ± 3.8 mL/kg/minute, P < 0.05) significantly increased in the ET group. Although RDW and serum erythropoietin concentration (EP) before the observation period did not differ between the ET and control groups, RDW (from 44.4 ± 4.7 to 43.4 ± 3.8 fL, P < 0.01) and EP (from 27.9 ± 15.8 to 22.9 ± 8.2 mIU/mL, P < 0.005) significantly decreased in the ET group, however, these parameters did not change in the control group. In the ET group, RDW was negatively correlated with peak oxygen uptake (r = -0.55, P < 0.01) and the changes in RDW before and after ET were positively correlated with the changes in EP (r = 0.39, P < 0.005).Thus, ET increases exercise tolerance and decreases RDW in association with increased oxygen uptake in patients with CAD.

Persistent increase in red cell size distribution width after acute diseases: A biomarker of hypoxemia?

BACKGROUND

A biomarker of hypoxic exposure would be useful in clinical diagnosis and prognosis. Acute hypoxia stimulates large increases in serum erythropoietin (EPO), and EPO induces formation of characteristic enlarged red blood cells (RBCs). The presence of large RBCs perturbs red cell distribution width (RDW).

METHODS

Using a >2M patient medical claims database, the human pathome was scanned for diseases where RDW rose 0-50days following a new diagnosis. The course of RDW after selected diagnoses was visualized by registering RDW measurements by diagnosis date.

RESULTS

Acute hemorrhage, which provokes EPO-driven erythropoiesis, is followed by increases in RDW but not mean cell volume (MCV). Similar RDW increases follow many acute diseases with risk of hypoxia, including heart failure, pneumonia, atelectasis, pulmonary embolism, pneumothorax, and sepsis. Elevations reach maximum within 1month after onset and subside to pre-disease levels about 6months later. Unlike the case with iron-deficiency anemia (IDA), RDW elevations after hypoxia-associated diseases are unaccompanied by discernible change in average RBC size.

CONCLUSIONS

As predicted by a model risk pathway linking hypoxia to formation of enlarged RBCs via EPO, acute hypoxemia-related disease episodes induce change in RBC size distribution. Further study is needed to explore whether a more sensitive and specific signal can be extracted from the fine structure of the RBC size distribution routinely measured in automated hemocytometers.

Red blood cell distribution width: A simple parameter with multiple clinical applications

The red blood cell distribution width (RDW) is a simple and inexpensive parameter, which reflects the degree of heterogeneity of erythrocyte volume (conventionally known as anisocytosis), and is traditionally used in laboratory hematology for differential diagnosis of anemias. Nonetheless, recent evidence attests that anisocytosis is commonplace in human disorders such as cardiovascular disease, venous thromboembolism, cancer, diabetes, community-acquired pneumonia, chronic obstructive pulmonary disease, liver and kidney failure, as well as in other acute or chronic conditions. Despite some demographic and analytical issues related to the routine assessment that may impair its clinical usefulness, an increased RDW has a high negative predictive value for diagnosing a variety of disorders, but also conveys important information for short- and long-term prognosis. Even more importantly, the value of RDW is now being regarded as a strong and independent risk factor for death in the general population. Although it has not been definitely established whether an increased value of RDW is a risk factor or should only be considered an epiphenomenon of an underlying biological and metabolic imbalance, it seems reasonable to suggest that the assessment of this parameter should be broadened far beyond the differential diagnosis of anemias. An increased RDW mirrors a profound deregulation of erythrocyte homeostasis involving both impaired erythropoiesis and abnormal red blood cell survival, which may be attributed to a variety of underlying metabolic abnormalities such as shortening of telomere length, oxidative stress, inflammation, poor nutritional status, dyslipidemia, hypertension, erythrocyte fragmentation and alteration of erythropoietin function. As such, the aim of this article is to provide general information about RDW and its routine assessment, to review the most relevant implications in health and disease and give some insights about its potential clinical applications.

Red cell distribution width as an independent predictor of exercise intolerance and ventilatory inefficiency in patients with chronic heart failure

PURPOSE

Peak oxygen uptake (peak VO₂) and ventilatory inefficiency (VE/VCO₂ slope) have proven to be strong prognostic markers in patients with chronic heart failure (CHF). Recently increased red cell distribution width (RDW) has emerged as an additional predictor of poor outcome in CHF. We sought to evaluate the relationship between RDW and cardiopulmonary exercise test (CPET) parameters in CHF patients and healthy controls.

MATERIALS AND METHODS

85 ambulatory CHF patients (68 men, 54±10 years) and 107 healthy controls, who underwent a symptom-limited CPET on a treadmill according to the modified Bruce ramp protocol, were enrolled. CHF patients and healthy controls were divided into RDW tertile groups and laboratory, echocardiographic, and CPET results were analyzed.

RESULTS

For patients with CHF, compared with patients in the lowest RDW tertile, those in the highest tertile had lower peak VO₂ (22 mL/kg/min vs. 28 mL/kg/min, p<0.001) and higher VE/VCO₂ slope (31 vs. 25, p=0.004). Multivariate regression analysis revealed RDW to be an independent predictor for peak VO₂ (β=-0.247, p=0.035) and VE/VCO₂ slope (β=0.366, p=0.004). The optimal cutoff value of RDW for predicting peak VO₂ ≤20 mL/kg/min and VE/VCO₂ slope ≥34 was 13.6% (sensitivity 53%, specificity 89%) and 13.4% (sensitivity 75%, specificity 82%), respectively. In contrast, for healthy controls, RDW was not related to both peak VO₂ and VE/VCO₂ slope.

CONCLUSION

Higher RDW is independently related to peak VO₂ and VE/VCO₂ slope only in patients with CHF. RDW assessment, an inexpensive and simple method, might help predict functional capacity and ventilatory efficiency in these patients.

Recurrence of left ventricular dysfunction in patients with restored idiopathic dilated cardiomyopathy

BACKGROUND

In some patients with nonischemic idiopathic dilated cardiomyopathy (DCM), left ventricular (LV) dysfunction improves spontaneously but can recur. The factors predicting recurrence of LV dysfunction in recovered idiopathic DCM are poorly defined. We investigated the clinical, echocardiographic, and laboratory variables affecting recurrence of LV dysfunction in patients who recovered from DCM.

HYPOTHESIS

The recurrence of LV dysfunction in recovered idiopathic DCM is impacted by clinical, echocardiographic, and laboratory variables.

METHODS

The study comprised 85 consecutively enrolled patients (62 males, age 57 ± 16 years) with DCM who achieved a restoration of LV systolic function. Patients were followed up for 50 ± 33 months after recovery from LV dysfunction without discontinuation of standard medication for heart failure with depressed ejection fraction. Clinical, echocardiographic, and laboratory variables were analyzed to identify factors independently associated with recurrence of LV dysfunction.

RESULTS

LV dysfunction recurred in 33 patients (23 males, age 64 ± 12 years). Univariate analysis revealed that age, duration from initial presentation to recovery time, diabetes, and LV end-diastolic dimension (LVEDD) at initial presentation were associated with recurrence of LV dysfunction. Multivariate analysis revealed that only age, diabetes, and LVEDD at initial presentation were independent predictors in patients who recovered from LV dysfunction.

CONCLUSIONS

The recurrence of LV dysfunction was significantly correlated with age, presence of diabetes, and LVEDD at initial presentation. Clinicians should consider maintenance of intensive care to patients who recovered from DCM with these factors.

Red cell distribution width is associated with physical inactivity and heart failure, independent of established risk factors, inflammation or iron metabolism; the EPIC-Norfolk study

AIMS

Red cell distribution width (RDW) is associated with increased risk of heart failure (HF). We examined in a healthy population (1) whether this association is independent of cardiovascular risk factors and iron metabolism and (2) whether RDW associates with physical activity.

METHODS AND RESULTS

Hazard ratios (HRs, highest quartile versus lowest quartile of RDW) for the risk of HF were calculated in 17,533 participants from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk cohort. During a follow-up of 11.2±2.2 years 640 participants developed a HF event. The HR for HF events was 1.44 (95%CI 1.15-1.80, p<0.001). There was a non-linear increase in HF risk across RDW quartiles. Adjustment for established risk factors (sex, age, diabetes, smoking, systolic blood pressure, total and high-density lipoprotein cholesterol) attenuated the HR for HF to 1.40 (95%CI 1.11-1.77, p=0.001). Adjustment for CRP, iron and ferritin levels did not affect the HR for HF. RDW levels are inversely associated with physical activity (per category β=-0.37, 95%CI -0.053 to -0.021, p<0.0001), independent of iron metabolism. However, the association between HF and RDW levels was not changed by physical activity.

CONCLUSIONS

This study confirms that RDW is associated with HF events in an apparently healthy middle-aged population. More importantly, we show that the underlying pathophysiology linking HF with anisocytosis is not reflected by conventional risk factors, nor it is explained by iron metabolism or inflammation. Furthermore, RDW levels were associated with physical inactivity, but this did not influence the RDW-associated-risk of heart failure.