Red cell distribution width and carotid atherosclerosis progression. The Tromsø Study

Predicting the risk of subclinical atherosclerosis based on interpretable machine models in a Chinese T2DM population

Background

Cardiovascular disease (CVD) has emerged as a global public health concern. Identifying and preventing subclinical atherosclerosis (SCAS), an early indicator of CVD, is critical for improving cardiovascular outcomes. This study aimed to construct interpretable machine learning models for predicting SCAS risk in type 2 diabetes mellitus (T2DM) patients.

Methods

This study included 3084 T2DM individuals who received health care at Zhenhai Lianhua Hospital, Ningbo, China, from January 2018 to December 2022. The least absolute shrinkage and selection operator combined with random forest-recursive feature elimination were used to screen for characteristic variables. Linear discriminant analysis, logistic regression, Naive Bayes, random forest, support vector machine, and extreme gradient boosting were employed in constructing risk prediction models for SCAS in T2DM patients. The area under the receiver operating characteristic curve (AUC) was employed to assess the predictive capacity of the model through 10-fold cross-validation. Additionally, the SHapley Additive exPlanations were utilized to interpret the best-performing model.

Results

The percentage of SCAS was 38.46% (n=1186) in the study population. Fourteen variables, including age, white blood cell count, and basophil count, were identified as independent risk factors for SCAS. Nine predictors, including age, albumin, and total protein, were screened for the construction of risk prediction models. After validation, the random forest model exhibited the best clinical predictive value in the training set with an AUC of 0.729 (95% CI: 0.709-0.749), and it also demonstrated good predictive value in the internal validation set [AUC: 0.715 (95% CI: 0.688-0.742)]. The model interpretation revealed that age, albumin, total protein, total cholesterol, and serum creatinine were the top five variables contributing to the prediction model.

Conclusion

The construction of SCAS risk models based on the Chinese T2DM population contributes to its early prevention and intervention, which would reduce the incidence of adverse cardiovascular prognostic events.

Relationship between red blood cell-related indices and coronary artery calcification

BACKGROUND

Red blood cell (RBC) indices such as RBC count and RBC distribution width (RDW) are associated with heart failure and coronary artery disease, but the relationship between RBC indices and coronary artery calcification (CAC) is unclear. This study aimed to investigate RBC indices' correlation with, and predictive value for, the presence and severity of CAC.

METHODS

In this study, 1257 hospitalized patients who received a coronary computed tomography angiography examination were finally selected. Patients were classified into a control group (without CAC, n = 655) and a calcification group (with CAC, n = 602) according to their CAC score. The calcification group was further divided into a low calcification group, medium calcification group, and high calcification group.

RESULTS

In the calcification group, the RBC count was lower, and the RDW-standard deviation (SD) and RDW-coefficient of variation (CV) were higher, than those in the control group (P < .05). In the high calcification group, the RBC count was significantly lower, and the RDW-SD and RDW-CV were significantly higher, than those in the low calcification group (P < .05). Multivariate logistic regression analysis showed that RBC count, RDW-SD, and RDW-CV were independent predictors of CAC presence. Furthermore, multivariate logistic regression analysis also showed that RBC count and RDW-SD were independent predictors of severe CAC.

CONCLUSIONS

RBC indices were significantly associated with the presence and severity of CAC, indicating that these RBC indices have the potential to be predictors of CAC.

Relationship between red cell distribution width/albumin ratio and carotid plaque in different glucose metabolic states in patients with coronary heart disease: a RCSCD-TCM study in China

BACKGROUND

Red cell distribution width/albumin ratio (RAR) is thought to be associated with the prognosis of a variety of diseases, including diabetes and heart failure. To date, no studies have focused on the relationship between RAR and carotid plaque in patients with coronary heart disease (CHD).

METHODS

A total of 10,267 patients with CHD were divided according to RAR quartiles (Q1: RAR ≤ 2.960; Q2: 2.960 < RAR ≤ 3.185; Q3: 3.185 < RAR < 3.441; Q4: RAR ≥ 3.441). Logistic regression was used to analyze the relationship between RAR and carotid plaques in CHD patients. The relationship between RAR and carotid plaques in according to sex, age and glucose regulation state groups were also assessed.

RESULTS

Among the 10,267 participants, 75.43% had carotid plaques. After adjusting for confounding factors, RAR was found to be associated with carotid plaque formation (OR: 1.23; 95% CI 1.08-1.39). The risk of carotid plaque formation in the Q4 group was 1.24 times higher than that in the Q1 group. After multivariate adjustment, RAR was associated with the risk of carotid plaque in female (OR: 1.29; 95% CI 1.09-1.52). And the relationship between RAR and carotid plaques in patients younger than 60 years old (OR: 1.43; 95% CI 1.16-1.75) was stronger than that in those older than 60 years old (OR: 1.29; 95% CI 1.10-1.51). Under different glucose metabolism states, RAR had the highest correlation with the risk of carotid plaques in diabetes patients (OR: 1.28; 95% CI 1.04-1.58).

CONCLUSIONS

RAR was significantly related to carotid plaques in patients with CHD. In addition, the correlation between RAR and the incidence of carotid plaque in patients with CHD was higher in women and middle-aged and elderly patients. In patients with CHD and diabetes, the correlation between RAR and carotid plaque was higher.

Association of Red Blood Cell Distribution Width and Neutrophil-to-Lymphocyte Ratio with Calcification and Cardiovascular Markers in Chronic Kidney Disease

We aimed to investigate the association between Red Blood Cell Distribution Width (RDW) and Neutrophil-to-Lymphocyte Ratio (NLR), simple, rapidly assessed markers from the complete blood count with vascular calcification (VC)/stiffness and cardiovascular disease (CVD) in chronic kidney disease (CKD). Dephosphorylated, uncarboxylated matrix Gla-protein (dp-ucMGP), and central/peripheral hemodynamics' parameters were measured in 158 CKD patients, including Hemodialysis and Peritoneal Dialysis. Spearman's rho analysis showed that RDW correlated with C-reactive protein (CRP) (r = 0.29, p < 0.001), dp-ucMGP (r = 0.43, p = < 0.0001), central diastolic blood pressure (DBP) (r = -0.19, p = 0.02), and albuminuria (r = -0.17, p = 0.03). NLR correlated with the duration of CVD (r = 0.32, p < 0.001), CRP (r = 0.27, p = 0.01), dp-ucMGP (r = 0.43, p < 0.0001), central DBP (r = -0.32, p < 0.0001) and eGFR (r = -0.25, p = 0.04). In multiple regression models, circulating dp-ucMGP was an independent predictor of RDW (β = 0.001, p = 0.001) and NLR (β = 0.002, p = 0.002). In CKD patients, RDW and NLR are associated with traditional and novel markers of VC and CVD.

Red Blood Cell Distribution Width: A Risk Factor for Prognosis in Patients with Ischemic Cardiomyopathy after Percutaneous Coronary Intervention

BACKGROUND

It has been demonstrated in previous studies that red blood cell distribution width (RDW) is correlated with the severity and prognosis of cardiovascular disease. The target of our study was to assess the relationship between RDW and the prognosis of ischemic cardiomyopathy (ICM) patients undergoing percutaneous coronary intervention (PCI).

METHODS

The study retrospectively enrolled 1986 ICM patients undergoing PCI. The patients were divided into three groups by RDW tertiles. The primary endpoint was major adverse cardiovascular events (MACE) and the secondary endpoints were each of the components of MACE (all-cause mortality, nonfatal myocardial infarction (MI) and any revascularization). Kaplan-Meier survival analyses were conducted to show the association between RDW and the incidence of adverse outcomes. The independent effect of RDW on adverse outcomes was determined by multivariate Cox proportional hazard regression analysis. In addition, the nonlinear relationship between RDW values and MACE was explored using restricted cubic spline (RCS) analysis. The relationship between RDW and MACE in different subgroups was determined using subgroup analysis.

RESULTS

As RDW tertiles increased, the incidences of MACE (Tertile 3 vs. Tertile 1: 42.6 vs. 23.7, p < 0.001), all-cause death (Tertile 3 vs. Tertile 1: 19.3 vs. 11.4, p < 0.001) and any revascularization (Tertile 3 vs. Tertile 1: 20.1 vs. 14.1, p < 0.001) increased significantly. The K-M curves showed that higher RDW tertiles were related to increased incidences of MACE (log-rank, p < 0.001), all-cause death (log-rank, p < 0.001) and any revascularization (log-rank, p < 0.001). After adjusting for confounding variables, RDW was proved to be independently associated with increased risks of MACE (Tertile 3 vs. Tertile 1: HR, 95% CI: 1.75, 1.43-2.15; p for trend < 0.001), all-cause mortality (Tertile 3 vs. Tertile 1: HR, 95% CI: 1.58, 1.17-2.13; p for trend < 0.001) and any revascularization (Tertile 3 vs. Tertile 1: HR, 95% CI: 2.10, 1.54-2.88; p for trend < 0.001). In addition, the RCS analysis suggested nonlinear association between RDW values and MACE. The subgroup analysis revealed that elderly patients or patients with angiotensin receptor blockers (ARBs) had a higher risk of MACE with higher RDW. Patients with hypercholesterolemia or without anemia also had a higher risk of MACE.

CONCLUSIONS

RDW was significantly related to the increased risk of MACE among ICM patients undergoing PCI.

Red cell distribution width: a novel predictive biomarker for stroke risk after transient ischaemic attack

OBJECTIVE

Predicting the prognosis of transient ischaemic attack (TIA) is difficult for many frontline clinicians. The purpose of this study was to determine whether subsequent stroke in TIA patients can be predicted via red blood cell distribution width (RDW).

MATERIAL AND METHODS

A total of 360 consecutive patients with new-onset TIA in our stroke centre, were enrolled over the period studied. The patients were divided into three groups: 103 TIA patients, 206 ischaemic stroke (IS) patients and 51 patients with haemorrhagic stroke (HS) within 7 days after TIA. Complete blood count, biochemical parameters and brain imaging were performed on all patients.

RESULTS

The mean RDW values of patients with IS and HS after TIA were significantly higher than patients with TIA (13.35 ± 1.59 vs 12.84 ± 1.19, 13.32 ± 1.08 vs 12.84 ± 1.19, respectively, all p ≤ .001). In a multivariate model, RDW was independently associated with stroke after TIA (IS: odds ratio (OR) = 2.52, 95% confidence interval (CI) = 1.46-3.35, p = .002; HS: OR = 1.511, 95% CI = 1.101-2.074, p = .011). Compared to ABCD² scores, the diagnostic power of RDW in the differentiation of patients with IS after TIA was better (area under curve (AUC): 0.731 vs 0.613, p = .015). When an RDW cut-off value of 13.95% was accepted for differentiating patients with IS from TIA, the sensitivity and specificity were 73.7% and 74.3%, respectively. However, the AUC for the ability of the RDW to predict HS was 0.653 (95% CI = 0.589-0.716; p < .001).

CONCLUSIONS

The early determination of RDW is a promising, rapid, easy and inexpensive biomarker to predict the subsequent stroke in TIA patients, especially for IS. KEY MESSAGESThe most important result of our study is to show that (1) the higher RDW, the earlier the stroke onset and (2) RDW ≥13.95% has a 2.52-fold risk of ischaemic stroke in TIA patients, and RDW ≥12.85% has a 1.51-fold risk of haemorrhagic stroke.As an economic and accessible hematological marker, baseline RDW may serve as a useful biomarker for risk stratification in TIA patients.

Associations of Red Cell Distribution Width With Coronary Artery Calcium in the General Population

Red cell distribution width (RDW) is a measure of the variability of erythrocyte volumes. RDW has been associated with incidence of cardiovascular diseases. However, the underlying mechanisms for the increased cardiovascular risk are still unclear. This study aimed to examine associations of RDW and coronary atherosclerosis in the general population. Computed tomography was performed and RDW was measured in fresh blood from 5772 subjects (aged 50–64 years) from the Swedish CArdioPulmonary bioImage Study (SCAPIS). Multinomial logistic regression was conducted to examine the associations between RDW and coronary artery calcium score (CACS). A total of 3902 (67.6%) individuals had low CACS (≤10), 18.6% had moderate CACS (>10 and ≤100) and 13.8% had high CACS (>100). The proportion with high CACS was 11.7%, 12.7%, 13.7% and 18.3%, respectively, in quartile 1–4 of RDW. After controlling for traditional risk factors, there were significant associations between RDW and high CACS: odds ratio = 1.51, 95% confidence interval: 1.18–1.94, and P = .001, for 4^th vs 1^st quartile of RDW. Elevated RDW is associated with coronary artery calcification in the middle-aged general population. RDW could be a reproducible and easily assessable biomarker of coronary calcification and cardiovascular risk.

Blood Cell Count Indexes of Systemic Inflammation in Carotid Artery Disease: Current Evidence and Future Perspectives

Carotid artery disease is commonly encountered in clinical practice and accounts for approximately 30% of ischemic strokes in the general population. Numerous biomarkers have been investigated as predictors of the onset and progression of carotid disease, the occurrence of cerebrovascular complications, and overall prognosis. Among them, blood cell count (BCC) indexes of systemic inflammation might be particularly useful, from a pathophysiological and clinical point of view, given the inflammatory nature of the atherosclerotic process. The aim of this review is to discuss the available evidence regarding the role of common BCC indexes, such as the neutrophil to lymphocyte ratio (NLR), monocyte to lymphocyte ratio (MLR), platelet to lymphocyte ratio (PLR), mean platelet volume (MPV), platelet distribution width (PDW), and red cell distribution width (RDW), in the diagnosis and risk stratification of carotid artery disease, and their potential clinical applications.

Aiding clinical assessment of neonatal sepsis using hematological analyzer data with machine learning techniques

INTRODUCTION

Early diagnosis and antibiotic administration are essential for reducing sepsis morbidity and mortality; however, diagnosis remains difficult due to complex pathogenesis and presentation. We created a machine learning model for bacterial sepsis identification in the neonatal intensive care unit (NICU) using hematological analyzer data.

METHODS

Hematological analyzer data were gathered from NICU patients up to 48 hours prior to clinical evaluation for bacterial sepsis. Five models, Support Vector Machine, K-nearest-neighbors, Logistic Regression, Random Forest (RF), and Extreme Gradient boosting (XGBoost), were trained on 60 hematological and nine clinical variables for 2357 cases (1692 control, 665 septic). Clinical feature only models (nine variables) were additionally trained and compared with models including hematological variables. Feature importance was used to assess relative contributions of parameters to performance.

RESULTS

The three best performing models were RF, Logistic Regression, and XGBoost. RF achieved an average accuracy of 0.74, AUC-ROC of 0.73, Sensitivity of 0.38, and Specificity of 0.88. Logistic Regression achieved an average accuracy of 0.70, AUC-ROC of 0.74, Sensitivity of 0.62, and Specificity of 0.73. XGBoost achieved an average accuracy of 0.72, AUC-ROC of 0.71, Sensitivity of 0.40, and Specificity of 0.85. All models with hematological variables had significantly stronger performance than models trained on only clinical features. Neutrophil parameters had the highest average feature importance.

CONCLUSIONS

Machine learning models using hematological analyzer data can classify NICU patients as sepsis positive or negative with stronger performance compared to clinical feature only models. Hematological analyzer variables could augment current sepsis classification machine learning algorithms.

Red blood cell distribution width is associated with hypoperfusion in carotid endarterectomy under regional anesthesia

BACKGROUND

A subset of patients submitted to carotid endarterectomy under regional anesthesia develop intraoperative neurologic deficit during carotid artery crossclamping related to critical cerebral perfusion, which may be owing to low flow or embolic phenomena. This subgroup is deemed prone to worse outcomes, which highlights its clinical relevance. The main aim of this study was to identify clinical and hematological predictors for intraoperative neurologic deficit. The secondary aim was to evaluate the perioperative prognostic value of postcarotid artery crossclamping manifestations of cerebral ischemia.

METHODS

Between January 2012 to January 2020, patients submitted to carotid endarterectomy under regional anesthesia in a tertiary referral center who presented intraoperative neurologic deficit were prospectively and consecutively included. This group constituted 8% of the total carotid endarterectomy performed in the center during this timeframe. The control group of patients was the subsequent patient submitted to carotid endarterectomy without intraoperative neurologic deficit in a 1:1 ratio. Blood samples were collected before surgery (<2 weeks). Propensity score matching was used to identify well-matched pairs of patients.

RESULTS

A total of 180 patients were included, with 90 (50% of the cohort and 8% of total carotid endarterectomies) presenting intraoperative neurologic deficit associated to clamping. Mean age was 71.4 ± 9.27 years in the study group and 68.8 ± 8.36 years in the control group. The clinical variables presenting significance after multivariate analysis include: age (adjusted odds ratio: 1.04, 5-95% confidence interval, [1.003-1.078]; P = .034), obesity (adjusted odds ratio: 3.537 [1.445-8.658]; P = .006), lower ipsilateral carotid stenosis grade (adjusted odds ratio: 0.725 [0.525-0.997]; P = .049), and higher contralateral carotid stenosis grade (adjusted odds ratio: 1.266 [1.057-1.516]; P = .010). Red cell distribution width coefficient of variation demonstrated statistical significance in predicting intraoperative neurologic deficit with an adjusted odds ratio of 1.394 (1.076-1.805); P = .012. The 30-day stroke rate was significantly higher in the intraoperative neurologic deficit group, with an adjusted odds ratio of 5.13 (5-95% confidence interval [1.058-24.87]; P = .042) after propensity score matching. Postoperative complications (Clavien-Dindo ≥2) were also associated with intraoperative neurologic deficit (after propensity score matching adjusted odds ratio of 2.748 [5-95% confidence interval, 0.976-7.741]; P = .051).

CONCLUSION

In this study, increased red cell distribution width coefficient of variation demonstrated value to predict intraoperative neurologic deficit. Additionally, age, obesity, a lower degree of ipsilateral carotid stenosis, and a higher degree of contralateral carotid stenosis also demonstrated ability to predict intraoperative neurologic deficit. Moreover, intraoperative neurologic deficit was an independent risk factor for 30-day stroke and postoperative complications Clavien-Dindo ≥2.

Red Blood Cell Distribution Width as a 5-Year Prognostic Marker in Patients Submitted to Carotid Endarterectomy

OBJECTIVE

Patients submitted to carotid artery endarterectomy (CEA) have a long-term risk of major adverse cardiovascular events (MACE) of 6-9% at 2 years. Hematological parameters have been shown to have a predictive function in atherosclerotic diseases, namely the red blood cell distribution width-coefficient of variation (RDW-CV). This parameter has been associated with worse outcomes such as myocardial infarction (MI), stroke, and all-cause mortality. This study aims to evaluate the potential role of preoperative hematologic parameters such as RDW-CV in predicting perioperative and long-term cardiovascular adverse events and mortality in patients submitted to CEA.

METHODS

From January 2012 to January 2019, 180 patients who underwent CEA with regional anesthesia in a tertiary care and referral center were selected from a prospective cohort database. Blood samples were collected preoperatively 2 weeks before admission, including a full blood count. The primary outcome included long-term MACE. Secondary outcomes included all-cause mortality, stroke, MI, acute heart failure, and major adverse limb events (MALE).

RESULTS

At baseline, 27.2% of patients had increased RDW-CV. Increased RDW-CV was independently associated with baseline hemoglobin (adjusted odds ratio [aOR] 0.715, 95% CI 0.588-0.869, p = 0.001) and atrial fibrillation (aOR 4.028, 95% CI 1.037-15.639, p = 0.001). After a median follow-up of 50 months, log-rank univariate analysis of RDW-CV demonstrated a significant association between increased RDW-CV and long-term all-cause mortality (log-rank <0.001), MACE (log-rank <0.001), and MI (log-rank = 0.017). After multivariate Cox regression analysis, increased RDW-CV was associated with increased long-term mortality (adjusted hazard ratio [aHR] 2.455, 95% CI 1.231-4.894, p = 0.011) and MACE (aHR 2.047, 95% CI 1.202-3.487, p = 0.008). A decreased hemoglobin to platelet ratio (aHR 2.650e-8, 95% CI 9.049e-15 to 0.078, p = 0.019) was also associated with all-cause mortality.

CONCLUSION

RDW is a widely available and low-cost marker that independently predicts long-term mortality, MACE, and MI after CEA. This biomarker could prove useful in assessing which patients would likely benefit from CEA in the long term.

BIRC6 Is Associated with Vulnerability of Carotid Atherosclerotic Plaque

Carotid atherosclerotic plaque rupture can lead to cerebrovascular accident (CVA). By comparing RNA-Seq data from vascular smooth muscle cells (VSMC) extracted from carotid atheroma surgically excised from a group of asymptomatic and symptomatic subjects, we identified more than 700 genomic variants associated with symptomatology (p < 0.05). From these, twelve single nucleotide polymorphisms (SNPs) were selected for further validation. Comparing genotypes of a hospital-based cohort of asymptomatic with symptomatic patients, an exonic SNP in the BIRC6 (BRUCE/Apollon) gene, rs35286811, emerged as significantly associated with CVA symptomatology (p = 0.002; OR = 2.24). Moreover, BIRC6 mRNA levels were significantly higher in symptomatic than asymptomatic subjects upon measurement by qPCR in excised carotid atherosclerotic tissue (p < 0.0001), and significantly higher in carriers of the rs35286811 risk allele (p < 0.0001). rs35286811 is a proxy of a GWAS SNP reported to be associated with red cell distribution width (RDW); RDW was increased in symptomatic patients (p < 0.03), but was not influenced by the rs35286811 genotype in our cohort. BIRC6 is a negative regulator of both apoptosis and autophagy. This work introduces BIRC6 as a novel genetic risk factor for stroke, and identifies autophagy as a genetically regulated mechanism of carotid plaque vulnerability.

Red Blood Cell Distribution Width Is Associated with Deterioration of Renal Function and Cardiovascular Morbidity and Mortality in Patients with Diabetic Kidney Disease

We sought to investigate the possible association between Red Blood Cell Distribution Width (RDW), vascular calcification, oxidative stress and renal function and all-cause/cardiovascular (CV) mortality, CV events and progression of kidney disease in a cohort of patients with Diabetic Kidney Disease (DKD). Carotid intima media thickness (cIMT) and oxidized low-density cholesterol were measured in 104 Type 2 Diabetes Mellitus (T2DM) patients with established DKD, distributed in all five stages of kidney disease and 38 diabetics with normal renal function. All patients were followed for 7 years with end-points all-cause and CV mortality, CV events and progression to End-Stage Renal Disease (ESRD). RDW was positively correlated with diabetes duration (r = 0.19, p = 0.023) and albuminuria (r = 0.29, p = 0.002). Multivariate regression analysis revealed that RDW was a strong, independent predictor of cIMT value (β = 0.031, p = 0.012). Kaplan-Meier curves and Cox proportional hazard models revealed that after adjustment for several cofounders, RDW was a significant and independent predictor for all-cause mortality, CV mortality, CV event and progression to ESRD (HR 1.75, p = 0.001, HR 2.03, p = 0.001, HR = 1.66, p < 0.0001 and HR 2.14, p = 0.001 respectively). RDW predicts mortality, CV events and deterioration of renal function in DKD, probably reflecting atherosclerosis.

Red Cell Distribution Width, Unlike Neutrophil Lymphocyte Ratio Is Unable to Accurately Gauge Enhanced Systemic Inflammation Associated With Panoramic Imaged Carotid Plaque

INTRODUCTION

We have previously shown that panoramic X-rays (PXs) demonstrating calcified carotid artery atheromas (CCAA) are associated with increased systemic inflammation demonstrating increased neutrophil lymphocyte ratios (NLRs), a validated risk indicator of fatal myocardial infarctions arising from coronary artery atherosclerosis. Using this same cohort of patients (with minor adjustments because of missing data), we sought to determine if a like association existed between PXs evidencing CCAA and elevated red blood cell distribution width (RDW) given conflicting data as its reliability relative to NLR as a biologic marker of system inflammation. We hypothesized that CCAAs on PXs would simultaneously be associated with both increased NLR and RDW.

MATERIALS AND METHODS

Investigators implemented a cross-sectional study design. Study sample consisted of patient medical records and PXs of white men ≥ 55 years. Two groups (N = 50 each) were constituted, one with atheromas (CCAA+) and without atheromas (CCAA-). The predictor variable was CCAA+ and outcome variables were NLR and RDW. Bootstrapping analysis was employed to analyze the differences in mean NLRs and RDWs between groups since the data was not normally distributed. Statistical significance determined to be ≤ 0.05 for all tests. The Medical Center's Institutional Review Board approved the research protocol.

RESULTS

A study group of 50 CCAA+ men (mean age 71; range 58-89 years) demonstrated a mean NLR of 2.98 ± 1.38 and an RDW of 13.21 ± 0.85. A control group of 50 CCAA- males (mean age 70 range; 55-91 years) evidenced a mean NLR of 2.38 ± 0.77 and an RDW of 13.16 ± 0.77. Bootstrapping comparison of NLR values evidenced significant (P = 0.008) difference (95% confidence interval of difference of mean: - 0.4272, 0.4384; observed effect size: 0.579) between groups; however, there was no significant difference in RDW values between the groups. Furthermore, logistic regression modeling demonstrated that for a one unit increase in NLR the odds of being CCAA+ (vs. CCAA-) increases by a factor of 1.659.

CONCLUSION

The existence of CCAA seen on PXs of elderly white men is associated with significantly (P = 0.008) elevated NLR values but is not associated with increases in RDW.

Correlation Between Red Cell Distribution Width and Peripheral Vascular Disease Severity and Complexity

A traditional hematological marker, red cell distribution width (RDW), is accepted as a novel marker of atherosclerotic vascular diseases. Clinical importance of the RDW as a prognostic biomarker in peripheral vascular disease (PVD) has been reported in a few studies. Herein, we aimed to show the correlation between RDW and PVD severity and its complexity in terms of angiographic evaluation. A total of 118 patients who underwent peripheral lower extremity angiography were subsequently evaluated retrospectively. Upon admission, RDW level was measured with automated complete blood count. Severity and complexity of the PVD was evaluated according to Trans-Atlantic Inter-Society Consensus (TASC II) classification. A TASC II A-B lesion was defined as simple PVD, and a TASC II C-D lesion was defined as prevalent and complex PVD. Then, both groups were compared statistically according to clinical, laboratory, and demographic features, including RDW levels. In 49.6% of the patients, TASC II C-D lesions were observed. Advanced age, male gender, and body mass index (BMI) were associated with TASC II groups. Red cell distribution width levels were correlated with presence of PVD, as well as TASC II grades (p:0.02). The fourth quartile (75th percentile) of the RDW levels was 14.1, and patients with RDW levels ≥14.1 had a more significant correlation with the presence and severity of PVD (p:0.001). In the multivariate regression analysis, elevated RDW was found to be an independent predictor of the presence of PVD and also TASC II C-D lesions (OR:2.26, with a 95% confidence interval (CI) 0.051-0.774; p:0.02). Elevated RDW levels was associated with TASC II C-D lesions, which indicated more prevalent and complex PVD.

Impact of Chronic Inflammation, Assessed by hs-CRP, on the Association between Red Cell Distribution Width and Arterial Cardiovascular Disease: The Tromsø Study

Red cell distribution width (RDW), a measure of variability in size of circulating erythrocytes, is associated with arterial cardiovascular disease (CVD), but the underlying mechanism remains unclear. We aimed to investigate the impact of chronic inflammation as measured by high-sensitivity C-reactive protein (hs-CRP) on this relationship, and explore whether RDW could be a mediator in the causal pathway between inflammation and arterial CVD. Baseline characteristics, including RDW and hs-CRP, were obtained from 5,765 individuals attending a population-based cohort study. We followed up participants from inclusion in the fourth survey of the Tromsø Study (1994/1995) until December 31, 2012. Multivariable Cox-regression models were used to calculate hazard ratios (HR) with 95% confidence intervals (CI) for incident myocardial infarction (MI) and ischemic stroke across quintiles of hs-CRP and RDW. Subjects with hs-CRP in the highest quintile had 44% higher risk of MI (HR: 1.44, 95% CI: 1.14-1.80), and 64% higher risk of ischemic stroke (HR: 1.64, 95% CI: 1.20-2.24) compared with subjects in the lowest quintile. RDW mediated 7.2% (95% CI: 4.0-30.8%) of the association between hs-CRP and ischemic stroke. Subjects with RDW in the highest quintile had 22% higher risk of MI (HR: 1.22, 95% CI: 0.98-1.54) and 44% higher risk of ischemic stroke (HR: 1.44, 95% CI: 1.06-1.97) compared with subjects in the lowest quintile. These risk estimates were slightly attenuated after adjustments for hs-CRP. Our findings suggest that chronic inflammation is not a primary mechanism underlying the relationship between RDW and arterial CVD.

The association between red cell distribution width and venous thromboembolism is not explained by myocardial infarction, stroke, or cancer

BACKGROUND

Red cell distribution width (RDW) is a risk marker of venous thromboembolism (VTE), myocardial infarction (MI), stroke, and cancer. Due to interrelations between these diseases, the association between RDW and VTE may be explained by MI, stroke, or cancer.

OBJECTIVE

To investigate whether the effect of RDW on VTE could be explained by intermediate development of MI, stroke, or cancer.

METHODS

RDW was measured in 24 363 participants of the Tromsø Study in 1994-1995. Incident VTE, MI, stroke, and cancer were registered until December 31, 2010. Conventional and cause-specific Cox-regression models were used to estimate hazard ratios (HR) for VTE with 95% confidence intervals (CI) across categories of RDW.

RESULTS

There were 502 first VTEs during a median follow-up of 16 years. In conventional Cox regression analysis, RDW in the highest quartile was associated with a 71% (HR 1.71, 95% CI 1.09-2.67) and 27% (HR 1.27, 95% CI 0.88-1.85) higher risk of VTE in men and women, respectively, compared to subjects in the lowest quartiles. The risk of VTE among subjects with RDW in the highest quartile was similar for men and women of postmenopausal age. In cause-specific analysis, where each individual contributed with person-time until the first occurring event only, the risk estimates were similar to those of the conventional Cox-regression analysis.

CONCLUSION

Our findings suggest that the association between RDW and future risk of VTE is not explained by intermediate development of MI, stroke, or cancer.

Association of red cell distribution width with all-cause and cardiovascular-specific mortality in African American and white adults: a prospective cohort study

Background

While the mortality rate is declining in the United States, the life expectancy gap among different population groups suggests a need to identify biomarkers to improve early identification of individuals at risk. Red cell distribution width (RDW), a measure of anisocytosis, is an emerging biomarker of chronic disease morbidity and mortality, particularly in the elderly. However, little is known about its association with mortality risk in younger adults. The objectives of this study were to investigate the association between RDW and overall and cause-specific mortality risk, and to identify novel determinants of RDW level.

Methods

We used prospectively collected data from the Healthy Aging in Neighborhoods of Diversity across the Life Span study conducted in Baltimore, Maryland. At baseline (2004–2009), the study recruited 3720 African American and white men and women aged 30–64 years. Participants provided peripheral venous blood for RDW measurement as part of complete blood count, and genotyping. Mortality status was ascertained using the National Death Index database through December 31, 2013. Multivariable adjusted Cox proportional hazards regression models were fitted to assess mortality risk, and multiple linear regression models to identify determinants of RDW level.

Results

Participants’ mean age was 48.1 (9.2) years. Of 2726 participants included in the present analyses, 57% were African Americans, and 56% were women. After 18,424 person-years of follow-up time, there were 226 deaths, and the leading cause of death were cardiovascular diseases (31.9%). Participants in the highest quartile of RDW had a 1.73-fold increased all-cause mortality risk (highest quartile vs. lowest quartile, multivariable adjusted hazard ratio = 1.73, 95% confidence interval: 1.10–2.74, p-trend = 0.006). This effect was significantly modified by body mass index (p-interaction = 0.004). Similar risk was observed for cardiovascular disease-specific mortality. Independent of body mass index, waist-hip ratio and illicit drug use were significantly associated with RDW.

Conclusions

Elevated RDW was associated with a substantial risk of all-cause and cardiovascular disease-specific mortalities that was modified by body mass index. Central obesity and illicit drug use influence RDW level. In vulnerable populations at-risk for health disparities, RDW could provide a useful and inexpensive biomarker of mortality.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-017-1313-6) contains supplementary material, which is available to authorized users.

Comparison of the prognostic values of inflammation markers in patients with acute pancreatitis: a retrospective cohort study

OBJECTIVES

Inflammation-based prognostic markers (neutrophil-lymphocyte ratio (NLR), prognostic nutritional index (PNI), red cell distribution width (RDW) and lymphocyte-monocyte ratio (LMR)) are associated with overall survival in some diseases. This study assessed their prognostic value in mortality and severity in acute pancreatitis (AP).

DESIGN

A retrospective cohort study.

SETTING

Patients with AP were recruited from the emergency department at our hospital.

PARTICIPANTS

A total of 359 patients with AP (31 non-survivors) were enrolled.

PRIMARY AND SECONDARY OUTCOME MEASURES

Mortality and severity of AP were the primary and secondary outcome measures, respectively. Biochemistry and haematology results of the first test after admission were collected. Independent relationships between severe AP (SAP) and markers were assessed using multivariate logistic regression models. Mortality prediction ability was evaluated using receiver operating characteristic (ROC) curves. Overall survival was evaluated using the Kaplan-Meier method, with differences compared using the log-rank test. Independent relationships between mortality and each predictor were estimated using the Cox proportional hazard models.

RESULTS

Compared with survivors of AP, non-survivors had higher RDW (p<0.001), higher NLR (p<0.001), lower LMR (p<0.001) and lower PNI (p<0.001) at baseline. C reactive protein (CRP; OR=8.251, p<0.001), RDW (OR=2.533, p=0.003) and PNI (OR=7.753, p<0.001) were independently associated with the occurrence of SAP. For predicting mortality, NLR had the largest area under the ROC curve (0.804, p<0.001), with a 16.64 cut-off value, 82.4% sensitivity and 75.6% specificity. RDW was a reliable marker for excluding death owing to its lowest negative likelihood ratio (0.11). NLR (HR=4.726, p=0.004), CRP (HR=3.503, p=0.003), RDW (HR=3.139, p=0.013) and PNI (HR=2.641, p=0.011) were independently associated with mortality of AP.

CONCLUSIONS

NLR was the most powerful marker of overall survival in this patient series.

Lower mean corpuscular hemoglobin concentration is associated with poorer outcomes in intensive care unit admitted patients with acute myocardial infarction

BACKGROUND

Accumulated studies have shown that hematological parameters [e.g., red blood cell distribution width (RDW), hemoglobin, platelet count] and serum potassium level can impact the prognosis of patients with acute myocardial infarction (AMI). However, no previous study has evaluated the prognostic values of these laboratory tests simultaneously.

METHODS

This study is based on an intensive care unit (ICU) database named Multiparameter Intelligent Monitoring in Intensive Care II (MIMIC II). Adult patients with AMI were included, and their hematological parameters and serum ion levels on admission were extracted. The relationships between these laboratory tests and hospital mortality were evaluated using a logistic regression model and receiver operating characteristic (ROC) curve analysis. The effects of these laboratory tests on 1-year mortality were evaluated using a Cox hazard regression model and Kaplan-Meier curve analysis.

RESULTS

In univariable analysis, increased white blood cell (WBC), neutrophil percentage, mean corpuscular volume (MCV), RDW, potassium and decreased red blood cell (RBC), hemoglobin, mean corpuscular hemoglobin concentration (MCHC), hematocrit and percentage of lymphocyte, monocyte, basophil and eosinophil were significantly associated with hospital mortality. In multivariable analyses, basophil percentage, potassium, WBC and MCHC were independently associated with hospital morality, while WBC, RDW, MCHC, potassium and percentages of neutrophil and lymphocyte were associated with 1-year mortality.

CONCLUSIONS

Hematological parameters and serum potassium can provide prognostic information in AMI patients. MCHC is an independent prognostic factor for both short and long term outcomes of AMI.

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.

Hematological Parameters Improve Prediction of Mortality and Secondary Adverse Events in Coronary Angiography Patients: A Longitudinal Cohort Study

Prediction of primary cardiovascular events has been thoroughly investigated since the landmark Framingham risk score was introduced. However, prediction of secondary events after initial events of coronary artery disease (CAD) poses a new challenge. In a cohort of coronary angiography patients (n = 1760), we examined readily available hematological parameters from the UPOD (Utrecht Patient Oriented Database) and their addition to prediction of secondary cardiovascular events. Backward stepwise multivariable Cox regression analysis was used to test their ability to predict death and major adverse cardiovascular events (MACE). Continuous net reclassification improvement (cNRI) and integrated discrimination improvement (IDI) measures were calculated for the hematological parameters on top of traditional risk factors to assess prediction improvement. Panels of 3 to 8 hematological parameters significantly improved prediction of death and adverse events. The IDIs ranged from 0.02 to 0.07 (all P < 0.001) among outcome measures and the cNRIs from 0.11 to 0.40 (P < 0.001 in 5 of 6 outcome measures). In the hematological panels red cell distribution width (RDW) appeared most often. The multivariable adjusted hazard ratio of RDW per 1 standard deviation (SD) increase for MACE was 1.19 [1.08-1.32], P < 0.001. Routinely measured hematological parameters significantly improved prediction of mortality and adverse events in coronary angiography patients. Accurately indicating high-risk patients is of paramount importance in clinical decision-making.

Red cell distribution width is associated with future risk of incident stroke. The Tromsø Study

Red cell distribution width (RDW), a measure of the variability in size of the circulating erythrocytes, is associated with cardiovascular morbidity and mortality. We aimed to investigate whether RDW was associated with incident stroke and case fatality in subjects recruited from the general population. Baseline characteristics were obtained from 25,992 subjects participating in the fourth survey of the Tromsø Study, conducted in 1994/95. Incident stroke was registered from inclusion until December 31, 2010. Cox regression models were used to calculate hazard ratios (HR) with 95% confidence intervals (95% CI) for stroke, adjusted for age, sex, body mass index, smoking, haemoglobin level, white blood cell count, thrombocyte count, hypertension, total cholesterol, triglycerides, self-reported diabetes, and red blood cell count. During a median follow-up of 15.8 years, 1152 participants experienced a first-ever stroke. A 1% increment in RDW yielded a 13% higher risk of stroke (multivariable HR: 1.13, 95% CI: 1.07-1.20). Subjects with RDW in the highest quintile compared to the lowest had a 37% higher risk of stroke in multivariable analysis (HR: 1.37, 95% CI: 1.11-1.69). Subjects with RDW above the 95-percentile had 55% higher risk of stroke compared to those in the lowest quintile (HR: 1.55, 95% CI: 1.16-2.06). All risk estimates remained unchanged after exclusion of subjects with anaemia (n=1102). RDW was not associated with increased risk of death within one year or during the entire follow-up after an incident stroke. RDW is associated with incident stroke in a general population, independent of anaemia and traditional atherosclerotic risk factors.