Elevated Red Cell Distribution Width Is Associated With Impaired Reverse Ventricular Remodeling and Increased Mortality in Patients Undergoing Cardiac Resynchronization Therapy

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.

The Ratio of Hemoglobin to Red Cell Distribution Width: A Strong Predictor of Clinical Outcome in Patients with Heart Failure

Background: Hemoglobin (Hb) is a standard and widely available clinical parameter that predicts clinical outcomes in heart failure (HF) patients. Red cell distribution width (RDW) is also a routinely measured clinical parameter that is predictive of clinical outcomes in HF. The ratio between Hb and RDW has yet to be evaluated in HF. Methods: We evaluated the predictive value of the Hb/RDW ratio on clinical outcomes in patients with HF. All patients diagnosed with chronic HF at a health maintenance organization were evaluated for Hb/RDW ratio and followed for cardiac-related hospitalizations and death. Results: The study cohort included 6888 HF patients. The mean Hb/RDW ratio was 0.85 ± 0.18; median was 0.85 (interquartile range 0.72–0.98). Patients with a lower Hb/RDW ratio were more likely to be women and had more comorbidities. The overall two year-mortality rate was 23.2%. Decreasing quantiles of the Hb/RDW ratio were associated with reduced survival rates and reduced event-free survival from death or cardiovascular-hospitalizations. Multivariable Cox regression analysis after adjustment for significant predictors demonstrated that low Hb/RDW ratio was a significant predictor of mortality, with a graded increased risk as Hb/RDW ratio decreased. Lower Hb/RDW ratio was also a significant independent predictor of the combined endpoint of death or cardiovascular hospitalizations. A sensitivity analysis evaluating Hb/RDW ratio as a continuous parameter using restricted cubic splines demonstrated a continuous increase in the mortality risk with decreasing Hb/RDW ratio, p < 0.0001 for the linear model. Conclusions: Hb/RDW ratio is a significant prognostic tool for predicting HF mortality and cardiovascular hospitalizations.

Increased red blood cell distribution width might predict left ventricular hypertrophy in patients with atrial fibrillation

The presence of left ventricular hypertrophy has been confirmed to be an independent risk factor for stroke and death in patients with atrial fibrillation. This retrospective study aimed to evaluate the potential risk factors for left ventricular hypertrophy in patients with atrial fibrillation.A series of consecutive patients diagnosed with atrial fibrillation between June 2018 and December 2019 were included. The patients' clinical data were analyzed. The cut-off values, sensitivity and specificity of the independent risk factors were calculated using a receiver operating characteristic curve.Among 87 patients with atrial fibrillation, 39 patients with left ventricular hypertrophy and 48 patients without left ventricular hypertrophy were included. Multivariate logistic regression analysis showed that red blood cell distribution width (odds ratio [OR] 4.89, 95% confidence interval [CI]: 1.69-14.13, P < .05) was an independent risk factor, while the concentration of low-density lipoprotein (OR 0.37, 95% CI: 0.17-0.83, P < .05) and left ventricular ejection fraction (OR 0.88, 95% CI: 0.82-0.95, P < .05) were inversely associated with left ventricular hypertrophy in atrial fibrillation patients. The receiver operating characteristic curve demonstrated that the area under the curve was 0.80 (95% CI: 0.71-0.90, P < .05) with a cut-off value of 13.05, and the red blood cell distribution width predicted left ventricular hypertrophy status among atrial fibrillation patients with a sensitivity of 72.1% and a specificity of 76.9%.Red blood cell distribution width was associated with left ventricular hypertrophy in patients with atrial fibrillation.

Full blood count as potential predictor of outcomes in patients undergoing cardiac resynchronization therapy

Almost a third of patients fulfilling current guidelines criteria have suboptimal responses following cardiac resynchronization therapy (CRT). Circulating biomarkers may help identify these patients. We aimed to assess the predictive role of full blood count (FBC) parameters in prognosis of heart failure (HF) patients undergoing CRT device implantation. We enrolled 612 consecutive CRT patients and FBC was measured within 24 hours prior to implantation. The follow-up period was a median of 1652 days (IQR: 837–2612). The study endpoints were i) composite of all-cause mortality or transplant, and ii) reverse left ventricular (LV) remodeling. On multivariate analysis [hazard ratio (HR), 95% confidence interval (CI)] only red cell count (RCC) (p = 0.004), red cell distribution width (RDW) (p < 0.001), percentage of lymphocytes (p = 0.03) and platelet count (p < 0.001) predicted all-cause mortality. Interestingly, RDW (p = 0.004) and platelet count (p = 0.008) were independent predictors of reverse LV remodeling. This is the first powered single-centre study to demonstrate that RDW and platelet count are independent predictors of long-term all-cause mortality and/or heart transplant in CRT patients. Further studies, on the role of these parameters in enhancing patient selection for CRT implantation should be conducted to confirm our findings.

Red Cell Distribution Width as a Novel Marker for Different Types of Atrial Fibrillation in Low and High Altitude

Background

Increased red cell distribution width (RDW) can predict the incidence and mortality of cardiovascular diseases. However, there are limited data on the relationship between RDW and altitude and the subtype of atrial fibrillation (AF). We investigated the effects of altitude on RDW in patients with different types of AF.

Methods

A total of 303 patients with nonvalvular AF were included. Of these, 156 lived in low altitude (77 paroxysmal AF, PAF; 79 persistent AF, PeAF) and 147 in high altitude (77 paroxysmal AF, PAF; 70 persistent AF, PeAF). In these groups, baseline characteristics, complete blood counts, serum biochemistry, and echocardiography were evaluated. Multivariate logistic regression analysis was conducted to determine the independent predictors of AF at the different altitudes.

Results

In both low and high altitudes, RDW and left atrial diameter (LAD) were higher in AF than control subjects (P < 0.05) and higher in persistent AF than paroxysmal AF (P < 0.05). Compared with any groups (PAF group, PeAF group, or control group) of low-altitude, RDW and LAD were found higher in high-altitude corresponding groups. Multivariate logistic regression analysis demonstrated that RDW, mean corpuscular volume (MCV), and LAD levels independently associated with AF patients in low altitude (RDW, OR 1.687, 95% CI 1.021–2.789; P < 0.05), while in high altitude, RDW, MCV, creatinine (Cr), and LAD were independent predictors for AF patients (RDW, OR 1.755, 95% CI 1.179–2.613; P < 0.05).

Conclusion

Elevated RDW levels may be an independent risk marker for nonvalvular AF, affected by type of AF and altitude.

Red Cell Distribution Width Predicts 90 Day Mortality in Continuous-Flow Left Ventricular Assist Device Patients

Red cell distribution width (RDW) measures the variance in size of circulating red blood cells and is a strong independent predictor of morbidity and mortality in cardiovascular disease and heart failure. Predictive power of RDW on mortality after continuous-flow left ventricular assist device (CF-LVAD) implantation remains largely unknown. Four hundred nine patients who underwent CF-LVAD implantation between April 2004 and December 2015 were retrospectively analyzed. The primary outcome of interest was 90 day mortality after CF-LVAD implantation. Median RDW before CF-LVAD implantation was 15.8%. Patients with elevated RDW (>15.8%) at baseline had significantly lower hemoglobin (10.6 ± 1.8 vs. 11.9 ± 2.1 mg/dl; p < 0.001), lower mean corpuscular volume (84.9 ± 7.7. vs. 88.7 ± 5.9; p < 0.001), higher blood urea nitrogen (BUN; 36.3 ± 21.8 vs. 30.1 ± 17.1; p < 0.001), lower albumin (3.4 ± 0.6 vs. 3.7 ± 0.5; p < 0.001), and higher total bilirubin levels (1.67 ± 2.21 vs. 1.29 ± 0.96). Red cell distribution width was independently predictive of 90 day mortality (odds ratio [OR], 1.16 for 1% increase; CI, 1.04-1.31; p = 0.010). Discriminatory power of RDW alone was comparable to model of end-stage liver disease excluding international normalized ratio (MELD-Xi) and HeartMate II risk scores. Mechanical unloading with CF-LVAD was associated with a reduction in RDW levels. These findings suggest that RDW, a simple and inexpensive test available through routine complete blood count, can be successfully used for mortality risk assessment in CF-LVAD candidates.

An overall and dose-response meta-analysis of red blood cell distribution width and CVD outcomes

Red blood cell distribution width (RDW) is the coefficient of variation of red blood cell size, considered to be associated with cardiovascular disease (CVD). This study aimed to comprehensively synthesize previous studies on RDW and CVD outcomes through an overall and dose-response meta-analysis. PubMed, Embase and Web of Science were searched systematically for English and Chinese language publications up to November 30, 2015. We extracted data from publications matching our inclusion criteria for calculating pooled hazard ratio (HR), which was used to assess prognostic impact of RDW on CVD. Twenty-seven articles, consisting of 28 studies and 102,689 participants (mean age 63.9 years, 63,703 males/36,846 females, 2,140 gender-unmentioned subjects) were included in the present meta-analysis. The pooled HRs are 1.12 (95% CI = 1.09-1.15) for the association of all-cause mortality (ACM) per 1% increase of RDW, 1.12(95% CI = 1.08-1.17) for major adverse cardiac events (MACEs) per 1% increase of RDW. A dose-response curve relating RDW increase to its effect on CVD outcomes was established (p_curve < 0.001). For every 1-unit increase of RDW, there is an increased risk of occurrence of ACM (pooled HR = 1.03, 95% CI = 1.02-1.04) and MACEs (pooled HR = 1.04, 95% CI = 1.01-1.06). This study indicates RDW may be a prognostic indicator for CVD outcomes.

Impact of Iron Deficiency on Response to and Remodeling After Cardiac Resynchronization Therapy

Iron deficiency is prevalent in heart failure with reduced ejection fraction and relates to symptomatic status, readmission, and all-cause mortality. The relation between iron status and response to cardiac resynchronization therapy (CRT) remains insufficiently elucidated. This study assesses the impact of iron deficiency on clinical response and reverse cardiac remodeling and outcome after CRT. Baseline characteristics, change in New York Heart Association functional class, reverse cardiac remodeling on echocardiography, and clinical outcome (i.e., all-cause mortality and heart failure readmissions) were retrospectively evaluated in consecutive CRT patients who had full iron status and complete blood count available at implantation, implanted at a single tertiary care center with identical dedicated multidisciplinary CRT follow-up from October 2008 to August 2015. A total of 541 patients were included with mean follow-up of 38 ± 22 months. Prevalence of iron deficiency was 56% at implantation. Patients with iron deficiency exhibited less symptomatic improvement 6 months after implantation (p value <0.001). In addition, both the decrease in left ventricular end-diastolic diameter (-3.1 vs -6.2 mm; p value = 0.011) and improvement in ejection fraction (+11% vs +15%, p value = 0.001) were significantly lower in patients with iron deficiency. Iron deficiency was significantly associated with an increased risk for heart failure admission or all-cause mortality (adjusted hazard ratio 1.718, 95% confidence interval 1.178 to 2.506), irrespectively of the presence of anemia (Hemoglobin <12 g/dl in women and <13 g/dl in men). In conclusion, iron deficiency is prevalent and affects both clinical response and reverse cardiac remodeling after CRT implantation. Moreover, it is a powerful predictor of adverse clinical outcomes in CRT.

Measurement of the Red Blood Cell Distribution Width Improves the Risk Prediction in Cardiac Resynchronization Therapy

Objectives. Increases in red blood cell distribution width (RDW) and NT-proBNP (N-terminal pro-B-type natriuretic peptide) predict the mortality of chronic heart failure patients undergoing cardiac resynchronization therapy (CRT). It was hypothesized that RDW is independent of and possibly even superior to NT-proBNP from the aspect of long-term mortality prediction. Design. The blood counts and serum NT-proBNP levels of 134 patients undergoing CRT were measured. Multivariable Cox regression models were applied and reclassification analyses were performed. Results. After separate adjustment to the basic model of left bundle branch block, beta blocker therapy, and serum creatinine, both the RDW > 13.35% and NT-proBNP > 1975 pg/mL predicted the 5-year mortality (n = 57). In the final model including all variables, the RDW [HR = 2.49 (1.27–4.86); p = 0.008] remained a significant predictor, whereas the NT-proBNP [HR = 1.18 (0.93–3.51); p = 0.07] lost its predictive value. On addition of the RDW measurement, a 64% net reclassification improvement and a 3% integrated discrimination improvement were achieved over the NT-proBNP-adjusted basic model. Conclusions. Increased RDW levels accurately predict the long-term mortality of CRT patients independently of NT-proBNP. Reclassification analysis revealed that the RDW improves the risk stratification and could enhance the optimal patient selection for CRT.

Red cell volume distribution width-to-platelet ratio in assessment of liver fibrosis in patients with chronic hepatitis B

BACKGROUND & AIMS

Precise assessment of liver fibrosis is necessary in patients with chronic liver disease. We investigated the performance of red cell volume distribution width-to-platelet ratio for the assessment of liver fibrosis in patients with chronic hepatitis B.

METHODS

A total of 482 consecutive patients with chronic hepatitis B who underwent liver biopsy between October 2005 and May 2014 were recruited. Liver stiffness was measured using transient elastography. FIB-4 score, red cell volume distribution width-to-platelet ratio and the aspartate aminotransferase-to-platelet ratio index were also assessed.

RESULTS

A total of 271 (56.2%) patients were males. The median age was 44 years. F1, F2, F3 and F4 fibrosis stages were identified in 68 (14.1%), 137 (28.4%), 64 (13.3%) and 213 (44.2%) of the patients respectively. The mean red cell volume distribution width-to-platelet ratio increased with liver fibrosis severity: F1, 0.065; F2, 0.077; F3, 0.097 and F4, 0.121 (P < 0.01). The area under the receiver operating characteristic curve of the red cell volume distribution width-to-platelet ratio for predicting significant fibrosis (≥F2) was 0.747. This result was inferior to transient elastography (0.866, P = 0.004), but comparable to FIB-4 (0.782, P = 0.427) and aspartate aminotransferase-to-platelet ratio index (0.716, P = 0.507). The area under the receiver operating characteristic curve of red cell volume distribution width-to-platelet ratio for predicting cirrhosis (F4) was 0.811, which was inferior to liver stiffness (0.915, P < 0.001), but comparable to FIB-4 (0.804, P = 0.805) and superior to aspartate aminotransferase-to-platelet ratio index (0.680, P < 0.001).

CONCLUSIONS

The accuracy of red cell volume distribution width-to-platelet ratio was acceptable for the assessment of liver fibrosis in patients with chronic hepatitis B. When transient elastography is not available, red cell volume distribution width-to-platelet ratio assessment is a simple method that can be used to reduce the need for liver biopsy.

Comparative diagnostic accuracy of red cell distribution width-to-platelet ratio versus noninvasive fibrosis scores for the diagnosis of liver fibrosis in biopsy-proven nonalcoholic fatty liver disease

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease and assessment of liver fibrosis is important. We aimed to investigate the performance of red cell volume distribution width-to-platelet ratio (RPR) in predicting liver fibrosis in patients with NAFLD and to compare it with well-known noninvasive predicting fibrosis scores (alanine aminotransferase ratio, aspartate aminotransferase platelet ratio index, fibrosis index, fibrosis 4, and fibrosis, cirrhosis index).

MATERIALS AND METHODS

Serum samples of consecutive biopsy-proven NAFLD patients were used to calculate the RPR index. Fibrosis stages were evaluated using the Brunt Criteria. Area under receiver operating characteristics curve was used to calculate predicting performance and compare with other noninvasive fibrosis scores.

RESULTS

One hundred and twenty-three consecutive patients with biopsy-confirmed NAFLD were recruited; 54 patients (43.9%) were women. The median age of the patients was 49 years. Fibrosis scores were F0-1, F2, F3, and F4 in 79 (64.2%), 27 (22%), 11 (8.9%), and 6 (4.9%) patients, respectively. The median RPR increased as the fibrosis scores progressed: F0, 0.0524; F1, 0.0534; F2, 0.0606; F3, 0.0815; and F4 0.2022. Area under receiver operating characteristics curve of the RPR was 0.69 in predicting significant fibrosis (≥ F2), 0.81 in advanced fibrosis (≥ F3), and 0.85 in F4, and all were statistically significant (P<0.001). Comparisons with other noninvasive fibrosis scores were not statistically significant (P>0.05). RPR was correlated with fibrosis r: 0.37, 95% confidence interval: (0.21-0.52), P<0.001. RPR was an independent predicting factor for identifying both significant and advanced fibrosis in regression analysis (P<0.05).

CONCLUSION

RPR was both correlated and able to predict liver fibrosis and may be suggested to reduce liver biopsy in NAFLD.

Association between red cell distribution width and the risk of heart events in patients with coronary artery disease

Red cell distribution width (RDW) has been found to be a novel prognostic biomarker in patients with coronary artery disease (CAD); however, the association between RDW and the risk of heart events in patients with CAD is yet to be fully elucidated. Thus, the aim of the present study was to determine whether an elevated RDW was associated with the Framingham risk score (FRS) in patients with CAD. Data were retrospectively collected from Affiliated Dongyang Hospital of Wenzhou Medical University (Dongyang, China). The patients had undergone a coronary angiography and their clinical data were integrated. The patients (male, 260; female, 132) were divided into two groups based on the results of the coronary angiography, namely the CAD (n=283) and control groups (n=109). The FRS was calculated for all the subjects, and complete blood count testing with biochemical measurements was performed. The mean RDW level was 13.7±1.8% in the CAD group and 13.1±1.0% in the control group, while the mean FRS was 9.0±4.9 in the CAD group and 6.4±3.9 in the control group. The RDW and FRS were significantly higher in the CAD group compared with the control group (P<0.001). No statistically significant differences were observed between the groups with regard to the hematocrit, mean corpuscular volume, platelets, glucose, urea, albumin, aspartate aminotransferase, total cholesterol, triglycerides (TG), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and N-terminal pro-brain natriuretic peptide (P>0.05). The RDW was shown to significantly correlate with the red blood cell (RBC) count (r=-0.133, P=0.029), hemoglobin level (r=-0.207, P=0.001) and TG level (r=0.226, P<0.001) within the laboratory parameters, as well as the FRS (r=0.206, P<0.001). In the stepwise multivariate linear regression, which included the RBC count, hemoglobin level, TG level and RDW, the FRS was predicted by hemoglobin (r²=0.034, P=0.001), TG (r²=0.059, P<0.001) and RDW (r²=0.030, P=0.003) parameters. Therefore, a novel association was revealed between higher levels of RDW and an elevated FRS in patients with CAD, which raises the possibility that a simple marker, RDW, may be associated with an increased risk of heart events in CAD patients.

Prognostic value of red blood cell distribution width for patients with heart failure: a systematic review and meta-analysis of cohort studies

Aims

Multiple studies have investigated the prognostic role of red blood cell distribution width (RDW) for patients with heart failure (HF), but the results have been inconsistent. The aim of the present study was to estimate the impact of RDW on the prognosis of HF by performing a systematic review and meta-analysis.

Methods and Results

The Embase, PubMed, and Web of Science databases were searched up to November 16, 2013 to identify eligible cohort studies. The quality of each study was assessed using the Newcastle-Ottawa Scale (NOS). The association between RDW, either on admission or at discharge, and HF outcomes (all-cause mortality [ACM], heart transplantation, cardiovascular mortality, and rehospitalization, etc.) were reviewed. The overall hazard ratio (HR) for the effect of RDW on ACM was pooled using a random-effects model, and the publication bias was evaluated using funnel plots and Eggers' tests. Seventeen studies, with a total of 18288 HF patients, were included for systematic review. All eligible studies indicated that RDW on admission and RDW at discharge, as well as its change during treatment, were of prognostic significance for HF patients. The HR for the effect of a 1% increase in baseline RDW on ACM was 1.10 (95% confidence interval: 1.07–1.13), based on pooling of nine studies that provided related data. However, publication bias was observed among these studies.

Conclusions

HF patients with higher RDW may have poorer prognosis than those with lower RDW. Further studies are needed to explore the potential mechanisms underlying this association.

Neutrophil-to-lymphocyte ratio predicts response to cardiac resynchronization therapy

BACKGROUND

Neutrophil-to-lymphocyte (N/L) ratio has been associated with adverse outcomes in patients with acute coronary syndromes and increased risk for long-term mortality in patients with acute decompensated heart failure. We aimed to investigate the prognostic value of neutrophil-to-lymphocyte ratio on response to cardiac resynchronization therapy (CRT).

MATERIAL AND METHODS

Seventy consecutive patients (mean age 58 ± 13 years; 40 men) undergoing CRT were included in the study. Hematological and echocardiographic parameters were measured before and 6 months after CRT. Echocardiographic response to CRT was defined as a ≥ 15% reduction in left ventricular end-systolic volume at 6-month follow-up.

RESULTS

After 6 months of CRT, 49 (70%) patients were responders. After 6 months, left ventricular ejection fraction (LVEF) had significantly increased, from 21 ± 7% to 34 ± 11% in responder patients (p = 0.001). N/L ratio decreased significantly, from 2.4 ± 1 to 2.1 ± 0.7 in responders (p = 0.04). In multivariate analysis, significant associates of echocardiographic response to CRT was evaluated adjusting for age, etiology of cardiomyopathy, baseline LVEF, New York Heart Association functional class, C-reactive protein, and baseline N/L ratio. Baseline N/L ratio was the only predictor of response to CRT (OR 1.506, 95% CI, 1.011-2.243, p = 0.035).

CONCLUSIONS

N/L ratio at baseline could help to identify patients with response to CRT.