Relation of red cell distribution width with CHA2DS2-VASc score in patients with nonvalvular atrial fibrillation

Red Blood Cell Distribution Width is a Biomarker of Red Cell Dysfunction Associated with High Systemic Inflammation and a Prognostic Marker in Heart Failure and Cardiovascular Disease: A Potential Predictor of Atrial Fibrillation Recurrence

At the beginning of the 21st century, approximately 2.3 million US adults had atrial fibrillation (AF), and there has been a 60% increase in hospital admissions for AF. Given that the expectancy is a continuous increase in incidence, it portends a severe healthcare problem. Considerable evidence supports the immune system and inflammatory response in cardiac tissue, and circulatory processes are involved in the physiopathology of AF. In this regard, finding novel inflammatory biomarkers that predict AF recurrence after catheter ablation (CA) is a prime importance global healthcare problem. Many inflammatory biomarkers and natriuretic peptides came out and were shown to have predictive capabilities for AF recurrence in patients undergoing CA. In this regard, some studies have shown that red blood cell distribution width (RDW) is associated with the risk of incident AF. This review aimed to provide an update on the evidence of the RDW as a biomarker of red cell dysfunction and its association with high systemic inflammation, and with the risk of incident AF. Through the literature review, we will highlight the most relevant studies of the RDW related to AF recurrence after CA. Many studies demonstrated that RDW is associated with all cause-mortality, heart failure, cardiovascular disease, and AF, probably because RDW is a biomarker of red blood cell dysfunction associated with high systemic inflammation, reflecting an advanced heart disease with prognostic implications in heart failure and cardiovascular disease. Thus, suggesting that could be a potential predictor for AF recurrence after CA. Moreover, the RDW is a parameter included in routine full blood count, which is low-cost, quick, and easy to obtain. We provided an update on the evidence of the most relevant studies of the RDW related to AF recurrence after CA, as well as the mechanism of the high RDW and its association with high systemic inflammation and prognostic marker in cardiovascular disease and heart failure.

Is Red Cell Distribution Width a Reliable Marker for Cardiovascular Diseases? A Narrative Review

Red cell distribution width (RDW) is an easy-to-access marker which is routinely measured in complete blood count (CBC) test. Besides the classic use of RDW as a marker for discriminating different types of anemia, recent studies had indicated the relationship between high RDW and cardiovascular diseases. High RDW is not only useful in the diagnosis and prognostication of various cardiovascular conditions but also could be used as a valuable tool for predicting the incidence of cardiovascular diseases. population-based studies have indicated that higher RDW could effectively predict the incidence of heart failure (HF), atherosclerotic diseases, and atrial fibrillation (AF). It has been also demonstrated that higher RDW is associated with worse outcomes in these diseases. Recent studies have shown that high RDW is also associated with other cardiovascular conditions including cardiomyopathies, and pulmonary hypertension. The predictive role of RDW in endovascular interventions has also been demonstrated by many recent studies. Here in this review, we attempt to compile the most recent findings with older reports regarding the relation between high RDW and HF, cardiomyopathies, pulmonary hypertension, AF, atherosclerotic disorders, primary hypertension, and the outcomes of endovascular interventions. we also discussed the role of RDW in the prognostication of different cardiovascular conditions when combined with classic classification criteria.

Development and Validation of a New Nomogram Model for Predicting Acute Ischemic Stroke in Elderly Patients with Non-Valvular Atrial Fibrillation: A Single-Center Cross-Sectional Study

Background and Aims

Non-valvular atrial fibrillation (NVAF) patients face a 3-5 times greater risk of acute ischemic stroke (AIS) compared to those without NVAF. This study aims to establish a novel clinical prediction model for AIS in elderly patients with NVAF by incorporating relevant biomarker indicators.

Methods

A total of 301 individuals diagnosed with NVAF were selected for this investigation at the Third Affiliated Hospital of Anhui Medical University. Based on the presence of AIS, patients were categorized into two groups: the Stroke Cohort and the Non-Stroke Cohort. Predictor screening was performed using the least absolute shrinkage and selection operation (LASSO) regression algorithm. The binary logistic regression equation was applied to fit the model, followed by internal validation using the bootstrap resampling method (1000 times). Receiver operating characteristic (ROC) curve, calibration degree curve plots, and clinical decision curve analysis (DCA) were generated, respectively. Finally, a nomogram was constructed to present the prediction model.

Results

The final results of this study revealed that neutrophil-to-lymphocyte ratio (NLR), red cell distribution width (RDW), lipoprotein(a) (Lp(a)), systolic pressure, history of stroke, hyperlipidemia were independent risk factors for AIS in elderly patients with NVAF (P<0.05). And the high-density lipoprotein cholesterol (HDL-C) was an independent protective factor (P<0.05). By incorporating these indicators, a nomogram prediction model for predicting AIS in elderly patients with NVAF was constructed. Comparative analysis between the nomogram predictive model and CHA2DS2-VASc score revealed that the AUC of the nomogram predictive model surpassed that of the CHA2DS2-VASc score (AUC: 0.881vs 0.850).

Conclusion

NLR, RDW, Lp(a), SP, history of stroke, hyperlipidemia, and HDL-C emerge as independent prognostic factors for acute ischemic stroke in elderly patients with non-valvular atrial fibrillation. The predictive utility of the nomogram model may potentially surpass that of the CHA2DS2-VASc scoring system.

Neutrophil-Lymphocyte Ratio and Red Blood Cell Distribution Width in Patients with Atrial Fibrillation and Rheumatic Valve Disease

The lifetime risk of developing atrial fibrillation (AF) is 1 in 3 adults, resulting in a prevalence of 2-4%. Rheumatic heart disease (RHD) is a frequent aetiology of valvular heart disease in lowand middle-income countries. Between 21% and 80% of patients with mitral valve disease, especially with stenosis, may have AF. Both these conditions, AF and RHD, present a state of persistent inflammation. In turn, inflammation is a frequent cause of anisocytosis, which can be evidenced through the parameter RDW (red bold cell distribution width). Factors associated with increased RDW are also known as risk factors associated with a higher incidence of AF. RDW may have an independent role in the pathogenesis of AF and the increased propensity of both thromboembolic and bleeding events. Another marker involved in the incidence of AF is the neutrophil-lymphocyte ratio. This is also a marker of oxidative stress and inflammation and is associated with a higher rate of AF recurrence. This review will evaluate these biomarkers and their association with cardiovascular events in patients with AF and RHD. The hypotheses and current debates about the relationship of biomarkers with the severity of chronic valve dysfunction, with acute rheumatic carditis in the paediatric population, and with the presence of thrombus in the left atrium will be discussed.

Relation of red cell distribution width with HAS-BLED score in patients with non-valvular atrial fibrillation

Background

Numerous researchers have shown that there is a close correlation between red cell distribution width (RDW) and cardiovascular disease such as heart failure, coronary heart disease, and atrial fibrillation. This study was designated to investigate the correlation between RDW and the Hypertension, Abnormal renal/liver function, Stroke, Bleeding history or predisposition, Labile international normalized ratio, Elderly, Drugs/alcohol (HAS-BLED) score.

Methods

The HAS-BLED scores of 251 hospitalized patients with non-valvular atrial fibrillation were calculated and the receiver operating characteristics were used to evaluate the predictive value of RDW on high HAS-BLED score (≥3 scores). Multiple logistic regression analysis was used to analyze the independent predictor of high HAS-BLED scores.

Results

Correlation analysis between RDW and HAS-BLED scores showed the RDW was positively correlated with HAS-BLED score, with r=0.393 (P<0.0001). The RDW of the high HAS-BLED score group was higher than that of the no-high HAS-BLED score group. The area under the receiver operating characteristic curve of RDW was 0.796 (0.740–0.844, P<0.0001) to predict a high HAS-BLED score, and multiple logistic regression analysis showed that a high RDW value could be used as an independent predictor of high HAS-BLED.

Conclusions

RDW value is associated with HAS-BLED value, and can be used as the independent predictive factor of high HAS-BLED scores.

Red blood cell distribution width and atrial fibrillation

Atrial fibrillation (AF) is the most frequent arrhythmia encountered in clinical practice and is a major health problem associated with remarkable morbidity, mortality and has considerable healthcare costs. Red blood cell distribution width (RDW) reflects the heterogeneity of the volume and size of red blood cells. It is an easily measured and inexpensive index that has been associated with several cardiovascular disease states. Accumulating evidence suggests that RDW is a prognostic marker of AF in various clinical settings. In this article, we review the available data regarding the prognostic role of RDW in AF development and perpetuation in diverse disease states as well as its role on the prediction of adverse outcomes.

Red Cell Distribution Width and Risk of Atrial Fibrillation and Subsequent Thromboembolism: The Tromsø Study

Introduction  Red cell distribution width (RDW) is associated with cardiovascular diseases, including atrial fibrillation (AF) and venous thromboembolism (VTE). Whether RDW is a risk marker for thromboembolic events in AF patients is scarcely known. We aimed to assess the association between RDW and the risk of AF, and AF-related VTE and ischemic stroke, in a population-based cohort. Methods  We measured RDW in 26,111 participants from the Tromsø Study (1994-1995), and registered incident AF cases through December 31, 2013. Among participants with AF, first-ever VTEs and ischemic strokes were registered from the date of AF diagnosis through the end of follow-up. We calculated hazard ratios (HRs) with 95% confidence intervals (CIs) for AF by quartiles of RDW. Furthermore, we calculated cause-specific HRs for VTE and ischemic stroke by tertiles of RDW for participants with AF. Results  There were 2,081 incident AF cases during a median of 18.8 years of follow-up. Subjects with RDW in the highest quartile (RDW ≥ 13.3%) had 30% higher risk of AF than those in the lowest quartile (RDW ≤ 12.3%). Among those with AF, subjects with RDW in the upper tertile had a doubled risk of ischemic stroke (HR 2.07, 95% CI 1.20-3.57). In contrast, RDW was not associated with incident VTE in subjects with AF. Conclusion  RDW was significantly associated with incident AF in a general population. Among subjects with AF, high RDW was associated with ischemic stroke, but not VTE.

Red blood cell distribution width: A marker of anisocytosis potentially associated with atrial fibrillation

The incorporation of biomarkers in the actually used risk scores seem to be helpful for early identifying atrial fibrillation (AF) patients at higher risk. The aim of this critical review of the scientific literature is to investigate the potential clinical significance of red blood cell distribution width (RDW) in AF. A systematic electronic search was carried out to identify all articles describing an epidemiological association between RDW and AF in adult human populations. Data abstraction was conducted on a final number of 35 articles (13 cross-sectional, 12 prospective and 10 retrospective studies). The results of these epidemiological investigations were all virtually concordant to emphasize that an enhanced RDW value is not only a predictive factor and a marker of AF but its measurement may also be helpful for predicting the risk of developing many adverse complications in patients with AF, such as recurrence and duration of AF, hospitalization for heart failure, bleeding, left atrial thrombosis and stasis, thromboembolic events and mortality. AF patients with RDW values exceeding the local reference range may be more aggressively investigated and managed, in order to identify and attenuate the impact of possible underlying disorders causing both anisocytosis and AF.

Severity stratification and prognostic prediction of patients with acute pancreatitis at early phase: A retrospective study

Severity stratification and prognostic prediction at early stage is crucial for reducing the rates of mortality of patients with acute pancreatitis (AP). We aim to investigate the predicting performance of neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and red-cell distribution width (RDW) combined with severity scores (sequential organ failure assessment [SOFA], bed-side index for severity of AP [BISAP], Ranson criteria, and acute physiology and chronic health evaluation II [APACHE II]) for severe AP (SAP) and mortality.A total of 406 patients diagnosed with AP admitted in a tertiary teaching hospital were enrolled. Demographic information and clinical parameters were retrospectively collected and analyzed. NLR, PLR, RDW, blood urea nitrogen (BUN), and AP severity scores (SOFA, BISAP, Ranson, and APACHE II) were compared between different severity groups and the survival and death group. Receiver-operating characteristic (ROC) curves for SAP and 28-day mortality were calculated for each predictor using cut-off values. Area under the curve (AUC) analysis and logistic regression models were performed to compare the performance of laboratory biomarkers and severity scores.Our results showed that NLR, PLR, RDW, glucose, and BUN level of the SAP group were significantly increased compared to the mild acute pancreatitis (MAP) group on admission (P < .001). The severity of AP increased as the NLR, SOFA, BISAP, and Ranson increased (P < .01). The AUC values of NLR, PLR, RDW, BUN, SOFA, BISAP, Ranson, and APACHE II to predict SAP were 0.722, 0.621, 0.787, 0.677, 0.806, 0.841, 0.806, and 0.752, respectively, while their AUC values to predict 28-day mortality were 0.851, 0.693, 0.885, 0.765, 0.968, 0.929, 0.812, and 0.867, respectively. BISAP achieved the highest AUC, sensitivity and NPV in predicting SAP, while SOFA is the most superior in predicting mortality. The combination of BISAP + RDW achieved the highest AUC (0.872) in predicting SAP and the combination of SOFA + RDW achieved the highest AUC (0.976) in predicting mortality. RDW (OR = 1.739), SOFA (OR = 1.554), BISAP (OR = 2.145), and Ranson (OR = 1.434) were all independent risk factors for predicting SAP, while RDW (OR = 7.361) and hematocrit (OR = 0.329) were independent risk factors for predicting mortality by logistic regression model.NLR, PLR, RDW, and BUN indicated good predictive value for SAP and mortality, while RDW had the highest discriminatory capacity. RDW is a convenient and reliable indicator for prediction not only SAP, but also mortality.

Predictive value of red cell distribution width on left atrial thrombus or left atrial spontaneous echo contrast in patients with non-valvular atrial fibrillation

OBJECTIVE

To evaluate the predictive value of red cell distribution width (RDW) on left atrial thrombus (LAT) or left atrial spontaneous echo contrast (LASEC) in patients with non-valvular atrial fibrillation (AF).

METHODS

We reviewed 692 patients who were diagnosed as non-valvular AF and underwent transesophageal echocardiography (TEE) in Guangdong Cardiovascular Institute from April 2014 to December 2015. The baseline clinical characteristics, laboratory test of blood routine, electrocardiograph measurements were analyzed.

RESULTS

Eighty-four patients were examined with LAT/LASEC under TEE. The mean RDW level was significantly higher in LAT/LASEC patients compared with the non-LAT/LASEC patients (13.59% ± 1.07% vs. 14.34% ± 1.34%; P < 0.001). Receiver-operating characteristic curve analysis was performed and indicated the best RDW cut point was 13.16%. Furthermore, multivariate logistic regression analysis indicated that RDW level > 13.16% could be an independent risk factor for LAT/LASEC in patients with AF.

CONCLUSION

Elevated RDW level is associated with the presence of LAT/LASEC and could be with moderate predictive value for LAT/LASEC in patients with non-valvular AF.

Role of Red Cell Distribution Width in the Relationship between Clinical Outcomes and Anticoagulation Response in Patients with Atrial Fibrillation

Little is known as to why elevated red cell distribution width (RDW) is associated with adverse clinical outcomes in patients with atrial fibrillation (AF). We hypothesized that RDW value might predict the intensity of anticoagulation, resulting in higher adverse events in patients with AF taking warfarin. We analyzed 657 patients with non-valuvular AF who took warfarin. The intensity of anticoagulation was assessed as mean time in the therapeutic range (TTR) and defined TTR ≥60% as an optimal intensity. The primary end-point was the composite of stroke/systemic embolism and major bleeding. The secondary end-point was the composite of stroke/systemic embolism, major bleeding and death. The relationship between the baseline RDW with TTR and clinical outcomes was assessed using categorical variables as quartiles or dichotomous variables. The mean value of TTR decreased as an increment of the RDW (45.2% vs. 44.7% vs. 40.8% vs. 35.2%, p<0.001). Primary and secondary end-points were significantly increased when TTR was less than 60% and RDW was more than 13.6%. Ratio of patients achieving optimal anticoagulation were significantly decreased as an increment of RDW. A RDW of ≥13.6% was a significant predictor for poor anticoagulation control (adjusted Odds ratio [OR] 0.43, 95% confidence interval [CI] 0.23–0.82), stroke (adjusted hazard ratio [HR] 3.86, 95% CI 1.11–13.40), primary (adjusted HR 1.88, 95% CI 1.12–3.16) and secondary end-point (adjusted HR 2.46, 95% CI 1.26–4.81). RDW was negatively associated with TTR in patients with AF. Therefore, RDW might be a useful marker for the prediction of anticoagulation response and clinical outcomes in patients with AF.

Red blood cell distribution width as a predictor of atrial fibrillation

BACKGROUND

Current evidence suggests that a higher red blood cell distribution width (RDW) may be associated with increased risk of atrial fibrillation (AF) development. Given that some controversial results have been published, we conducted a systematic review of the current literature along with a comprehensive meta-analysis to evaluate the association between RDW and AF development.

METHODS

We performed a systematic search of the literature using electronic databases (PubMed, Ovid, Embase, and Web of Science) to identify studies reporting on the association between RDW and AF development published until June 2016. We used both fix-effects and random-effects models to calculate the overall effect estimate. An I²  > 50% indicates at least moderate statistical heterogeneity. A sensitivity analysis and subgroup analysis were performed to find the origin of heterogeneity.

RESULTS

A total of 12 studies involving 2721 participants were included in this meta-analysis. The standardized mean difference in the RDW levels between patients with and those without AF development was 0.66 units (P < .05; 95% confidence interval 0.44-0.88). A significant heterogeneity between the individual studies was observed (P < .05; I²  = 80.4%). A significant association between the baseline RDW levels and AF occurrence or recurrence following cardiac procedure or surgery was evident (SMD: 0.61; 95% confidence interval 0.33-0.88; P < .05) with significant heterogeneity across the studies (I²  = 80.7%; P < .01).

CONCLUSIONS

Our comprehensive meta-analysis suggests that higher levels of RDW are associated with an increased risk of AF in different populations.

Relation of red blood cell distribution width with CHADS2 and CHA2DS2-VASc score in Chinese patients with non-valvular atrial fibrillation

BACKGROUND

Higher red cell distribution width (RDW) predicts adverse events in patients with cardiovascular diseases. However, there are limited data regarding the relationship between RDW and thromboembolism risk in the patients with atrial fibrillation (AF). We aimed to investigate the association between RDW and CHADS2, CHA2DS2-VASc scores used for the evaluation of thromboembolic risk in patients with non-valvular atrial fibrillation (AF).

METHODS

Our study included 99 patients with AF (68 paroxysmal AF; 31 persistent AF). We calculated CHADS₂ and CHA₂DS₂-VASc risk scores for each patient, and we carefully recorded clinical characteristics as well as laboratory and echocardiographic parameters. According to CHADS₂ and CHA₂DS₂-VASc scores, we divided the AF patients into 2 groups (low-intermediate risk and high risk group). Subsequently, we compared the aforementioned parameters between the 2 groups, and we evaluated the relationship between RDW and CHADS₂/CHA2DS₂-VASc score. Finally, multivariate logistic regression analysis was performed to find independent predictors of high CHADS₂, CHA₂DS₂-VASc scores.

RESULTS

Patients with high CHADS₂, CHA₂DS₂-VASc scores had older age, higher RDW, and creatinine levels, increased left atrial diameter and lower left ventricular ejection fraction, compared to the low CHADS₂, CHA₂DS₂-VASc score group. Multivariate logistic regression analysis showed that RDW was an independent predictor for high CHADS₂, CHA₂DS₂-VASc scores(OR: 2.184 and OR: 5.748; all P<0.05).

CONCLUSION

RDW is significantly correlated with CHADS₂ and CHA₂DS₂-VASc score in the patients with AF, while is an independent predictor for high CHADS₂ and CHA₂DS₂-VASc score.

Prognostic Value of Red Blood Cell Distribution Width on Bleeding Events in Nonvalvular Atrial Fibrillation Patients Taking Dabigatran (110 mg b.i.d.) after Catheter Ablation

OBJECTIVES

Recent research has indicated that red blood cell distribution width (RDW) is associated with the prognosis of cardiovascular diseases such as chronic heart failure and coronary heart disease. We aimed to study the predictive value of RDW for bleeding events in patients with nonvalvular atrial fibrillation (NVAF) during the administration of 110 mg of dabigatran twice a day after catheter ablation.

METHODS

One hundred and seventy-two NVAF patients who were hospitalized and received catheter ablation in Jiangsu Provincial People's Hospital from January 2014 to January 2015 were enrolled (110 mg of dabigatran was administered orally to outpatients preoperatively twice a day for 3 weeks). The enrolled patients were divided into the high RDW (>12.8%) group (n = 85) and the low RDW (≤12.8%) group (n = 87) according to the median RDW. The activated partial thromboplastin time (APTT) at dabigatran trough concentration was also detected. Patients were followed up for 3 months to observe the occurrence of bleeding events, and the predictive value of RDW as well as APTT for bleeding events was assessed from receiver-operating characteristic (ROC) analyses.

RESULTS

In all patients, preoperatively, no bleeding events were observed and the APTT did not exceed twice the normal upper limit. Thirteen cases of bleeding events, all minor bleeding, occurred after a 3-month follow-up: 3 of gingival bleeding, 3 of urinary tract bleeding, 3 conjunctival hemorrhages and 4 subcutaneous hemorrhages. The incidence of bleeding events in the low RDW group was lower than in the high RDW group (3.4 vs. 11.8%, p = 0.039). The areas under the ROC curve for RDW and APTT to predict the occurrence of bleeding events were 0.737 (cutoff point 13.25%; p < 0.05) and 0.558 (p > 0.05), respectively.

CONCLUSION

RDW was associated with the occurrence of bleeding events in NVAF patients on dabigatran (110 mg twice a day) after ablation, while also being an independent predictor of bleeding events. RDW had superior predictive value for bleeding events over APTT when APTT did not exceed twice the normal upper limit.

Red cell distribution width as a novel predictor for clinical outcomes in patients with paroxysmal atrial fibrillation

AIMS

Elevated red cell distribution width (RDW) has been known to be associated with adverse long-term outcomes in patients with cardiovascular diseases. We aimed to evaluate relationship between RDW values and clinical outcomes in patients with paroxysmal atrial fibrillation (AF).

METHODS AND RESULTS

We analysed 567 patients who were newly diagnosed as paroxysmal AF. Clinical outcomes were analysed after median 4.8 (3.4-6.9) years follow-up. The composite clinical outcomes were defined as the composite of death, hospitalization due to heart failure, and new-onset stroke. Bleeding events were composed of major and minor bleeding. The relationship of RDW with clinical outcomes was assessed using continuous or categorical variables as quartiles: <12.8, 12.8-13.2, 13.3-13.8, and ≥13.9%. Patients with the highest RDW quartile were the oldest and had more frequent history of heart failure. CHA2DS2-VASc score was increased along with increasing RDW quartiles (1.75 ± 1.48 vs. 1.77 ± 1.63 vs. 1.87 ± 1.61 vs. 2.33 ± 1.65, P = 0.008). Incidence of new-onset stroke (log-rank P = 0.032), the composite clinical outcomes (log-rank P = 0.014), and bleeding events (log-rank P = 0.001) were increased as increasing RDW quartiles. Multivariate analysis identified that RDW was a significant predictor for new-onset stroke [adjusted hazard ratio (HR) 1.32, 95% confidence interval (CI) 1.06-1.65, P = 0.015], the composite clinical outcomes (adjusted HR 1.21, 95% CI 1.03-1.41, P = 0.017), and bleeding events (adjusted HR 1.36, 95% CI 1.13-1.64, P = 0.001).

CONCLUSIONS

RDW can be a new, useful, novel predictor of clinical and safety outcomes in patients with paroxysmal AF.

P-wave dispersion: an update

P-wave dispersion (PWD, Pd or Pdis) is a noninvasive electrocardiographic (ECG) marker for atrial remodeling and predictor for atrial fibrillation (AF). PWD is defined as the difference between the widest and the narrowest P-wave duration recorded from the 12 ECG leads. Increased P-wave duration and PWD reflect prolongation of intraatrial and interatrial conduction time with lack of a well-coordinated conduction system within the atrial muscles, with inhomogeneous, asynchronic, pro-inflammatory and anti-inflammatory effect mediated by interleukin-6 (IL-6) in patients with the CG + GG genotype IL-6 -634C/G polymorphism [1] and discontinuous propagation of sinus impulses mainly between the left and right atria, interstitial/extracellular fibroblast activation and collagen deposition with fibrosis (via TGF-β) in atrial tissue, insufficient blood supply, significant not isotropic myoelectric activity, and thin wall thickness and consequent expansion tendency all well-known electrophysiological characteristics in patients with atrial arrhythmias and especially paroxysmal atrial fibrillation (PAF) [2].

Red blood cell distribution width and cardiovascular diseases

BACKGROUND

The red blood cell distribution width (RDW) is a rather simple measure of red blood cell (RBC) size heterogeneity (i.e., anisocytosis), which is easily calculated by dividing the standard deviation (SD) of erythrocyte volumes for the mean corpuscular volume (MCV). Emerging evidence suggests that, besides RBC abnormalities, many human disorders may be frequently associated with a high degree of anisocytosis.

METHODS

In this narrative review, we analyzed the current scientific literature about the putative role and the potential epidemiologic association between RDW and cardiovascular diseases. The findings of the most representative epidemiological studies were summarized and discussed.

RESULTS

Overall, considerable and convincing evidence has been brought that an increased RDW value is associated with acute coronary syndrome (ACS) [including acute myocardial infarction (AMI)], ischemic cerebrovascular disease (including stroke), peripheral artery disease (PAD), as well as with atrial fibrillation (AF), heart failure (HF) and hypertension. Higher anisocytosis also significantly and independently predicts adverse outcomes in patients with these conditions.

CONCLUSIONS

Although the role of anisocytosis in the pathogenesis of cardiovascular diseases remains uncertain, the considerable evidence available so far suggests that the clinical use of RDW may be broadened beyond the conventional boundaries of erythrocyte disorders, in particular for assisting the diagnosis and prognostication of patients with ACS, ischemic cerebrovascular disease, PAD, HF and AF.

The association between red cell distribution width and stroke in patients with atrial fibrillation

OBJECTIVE

Red cell distribution width is associated with increased risk of cardiovascular morbidity and mortality. We aimed to assess its association with stroke in patients with atrial fibrillation.

METHODS

By using the computerized database of the largest Health Maintenance Organization in Israel, we identified a cohort of adults with atrial fibrillation diagnosed before January 1, 2012. Eligible subjects were not taking anticoagulants at baseline and had at least 1 blood cell count performed in 2011 (41,140 subjects). The cohort was followed for the first occurrence of stroke until December 31, 2012.

RESULTS

Overall, 1692 subjects developed stroke during 38,024 person-years of follow-up (stroke rate, 4.45 per 100 person-years). Stroke incidence rate increased across red cell distribution width quartiles: 3.26, 3.71, 5.01, and 6.05 per 100 person-years in the lowest (≤ 13.4%), second (13.4%-14.1%), third (14.1%-15.0%), and highest (>15%) red cell distribution width quartiles, respectively. On multivariate analysis adjusting for Congestive heart failure, Hypertension, Age ≥ 75, Diabetes, and Prior Stroke or TIA (doubled) (CHADS2) score risk factors, the hazard ratio for stroke was 1.29 (95% confidence interval, 1.17-1.42) in subjects with red cell distribution width >14.5% compared with those with values ≤ 14.5% and was similar in subjects with and without anemia. When analyzed as quartiles, the hazard ratio for stroke was 1.33 (confidence interval, 1.15-1.53) in the highest quartile compared with the lowest quartile and was similar in subjects with and without anemia. The area under the receiver operating characteristic curve was 0.598 for (CHADS2) score and increased to 0.618 when red cell distribution width was included in the model (P < .001).

CONCLUSIONS

Red cell distribution width is directly associated with the risk of stroke regardless of anemia status and improves the predictive accuracy for stroke in patients with atrial fibrillation.

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.

Seasonal changes in gene expression represent cell-type composition in whole blood

Seasonal patterns in behavior and biological parameters are widespread. Here, we examined seasonal changes in whole blood gene expression profiles of 233 healthy subjects. Using weighted gene co-expression network analysis, we identified three co-expression modules showing circannual patterns. Enrichment analysis suggested that this signal stems primarily from red blood cells and blood platelets. Indeed, a large clinical database with 51 142 observations of blood cell counts over 3 years confirmed a corresponding seasonal pattern of counts of red blood cells, reticulocytes and platelets. We found no direct evidence that these changes are linked to genes known to be key players in regulating immune function or circadian rhythm. It is likely, however, that these seasonal changes in cell counts and gene expression profiles in whole blood represent biological and clinical relevant phenomena. Moreover, our findings highlight possible confounding factors relevant to the study of gene expression profiles in subjects collected at geographical locations with disparaging seasonality patterns.