A narrative review of red blood cell distribution width as a marker for pulmonary embolism

Prevalence and Risk Factors of Pulmonary Embolism in COPD Patients Complicated with Secondary Polycythemia

Purpose

This study aimed to establish the prevalence of pulmonary embolism (PE) in chronic obstructive pulmonary disease (COPD) patients with secondary polycythemia (SP) and explore the risk factors for PE in COPD patients with SP.

Patients and Methods

We analyzed the prevalence of PE among COPD patients with SP who were hospitalized at Qinghai Provincial People's Hospital between January 2015 and December 2020. From January 2021 to January 2024, we enrolled patients into three groups (COPD+SP+PE, COPD+SP, and control) and performed laboratory measurements, biomarkers, echocardiography, and pulmonary function tests. Patients in the COPD+SP group received clinical treatment, and biomarkers were measured again seven days after treatment.

Results

The prevalence of PE in patients with COPD SP was 5.21%. We found that COPD+SP+PE group had significantly higher levels of erythrocyte distribution width (RDW), platelet volume distribution width (PDW), mean platelet volume (MPV), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), monocyte to large platelet ratio (MLPR), 5-hydroxytryptamine (5-HT), activated protein C (APC), urokinase-type plasminogen activator (u-PA), thrombomodulin (TM), interleukin-38 (IL-38), tissue factor (TF), and fractalkine (FKN) in contrast to COPD+SP group. Biomarkers, such as FKN, β-thromboglobulin (β-TG), APC, u-PA, TM, TF, and IL-38, were risk factors for COPD patients with SP who are complicated by PE. Clinical treatment significantly reduced the levels of β-TG, IL-38, APC, endothelin-1 (ET-1), u-PA, FKN, TM, 5-HT, and neutrophil extracellular traps (NETs) in patients with COPD+SP.

Conclusion

PE incidence was significantly higher in patients with COPD and SP. In COPD patients with SP, routine joint detection of blood and cardiac markers, blood gas analysis, and pulmonary function tests can help to identify patients with PE. APC, u-PA, TF, FKN, TM, and IL-38 are risk factors for PE in patients with COPD and SP, and clinical treatment can effectively reduce this risk.

Does complete blood count have a role in the prediction of deep vein thrombosis?

METHODS

It was planned as a retrospective case-control study in which 1,527 patients between January 2022 and September 2022 were evaluated. After the eligibility criteria, systematic sampling was performed and analyzed in the case group (103) and the control group (179) patients. The predictive significance of Hb, NLR, PLR, MPV, PLT, MPV/PLT, monocytes, lymphocytes, eosinophils, RDW, LMR, and PDW parameters for the development of DVT was investigated. Then, logistic regression analysis was performed with these parameters to analyze the predictive value. The cutoff point was determined by performing ROC analysis for the statistically significant parameters.

RESULTS

Neutrophil, RDW, PDW, NLR, and MPV/platelet values were statistically higher in the DVT group than the control group. Lymphocyte, PLT, and LMR values were statistically lower in the DVT group than the control group. There was no statistical difference between the two groups in terms of neutrophils, monocytes, eosinophils, Hb, MPV, and PLR values. RDW and PDW values were statistically significant for DVT prediction (p < 0.001, OR = 1.183 and p < 0.001, OR = 1.304, respectively). According to ROC analysis, 45.5 fL for RDW and 14.3 fL for PDW were determined as the cutoff points for DVT prediction.

CONCLUSION

We found RDW and PDW to be significant in terms of DVT prediction in our study. We found the NLR and MPV/PLT to be higher in the DVT group, and the LMR to be lower in the DVT group, but we found that there was no statistically significant predictive value. CBC can be used as an inexpensive and easily accessible test that has predictive significance for DVT. In addition, these findings need to be supported by prospective studies in the future.

Construction and validation of risk prediction models for pulmonary embolism in hospitalized patients based on different machine learning methods

Objective

This study aims to apply different machine learning (ML) methods to construct risk prediction models for pulmonary embolism (PE) in hospitalized patients, and to evaluate and compare the predictive efficacy and clinical benefit of each model.

Methods

We conducted a retrospective study involving 332 participants (172 PE positive cases and 160 PE negative cases) recruited from Guangdong Medical University. Participants were randomly divided into a training group (70%) and a validation group (30%). Baseline data were analyzed using univariate analysis, and potential independent risk factors associated with PE were further identified through univariate and multivariate logistic regression analysis. Six ML models, namely Logistic Regression (LR), Decision Tree (DT), Random Forest (RF), Naive Bayes (NB), Support Vector Machine (SVM), and AdaBoost were developed. The predictive efficacy of each model was compared using the receiver operating characteristic (ROC) curve analysis and the area under the curve (AUC). Clinical benefit was assessed using decision curve analysis (DCA).

Results

Logistic regression analysis identified lower extremity deep venous thrombosis, elevated D-dimer, shortened activated partial prothrombin time, and increased red blood cell distribution width as potential independent risk factors for PE. Among the six ML models, the RF model achieved the highest AUC of 0.778. Additionally, DCA consistently indicated that the RF model offered the greatest clinical benefit.

Conclusion

This study developed six ML models, with the RF model exhibiting the highest predictive efficacy and clinical benefit in the identification and prediction of PE occurrence in hospitalized patients.

Associations of RBC counts and incidence of DVT in patients with spinal cord injury: a five year observational retrospective study

BACKGROUND

The role of red blood cell (RBC) counts as potential independent risk factors for deep vein thrombosis (DVT) in patients with spinal cord injury (SCI) remains uncertain. This study aims to clarify the associations between RBC counts and DVT incidence among this population.

METHODS

A retrospective analysis was performed on 576 patients with SCI admitted to the rehabilitation medicine department from January 1, 2017 to December 31, 2021. After exclusions, 319 patients were analyzed, among which 94 cases of DVT were identified.

RESULTS

Mode of injury, D-dimer and anticoagulant therapy were significant covariates (P < 0.05). Age, fibrinogen, D-dimer, anticoagulant therapy and American Spinal Cord Injury Association impairment scale (AIS) grades were associated with RBC counts and DVT incidence (P < 0.05). Adjusting for these factors, a 1.00 × 10^12/L increase in RBC counts correlated with a 45% decrease in DVT incidence (P = 0.042), revealing a "U" shaped relationship with a pivot at 4.56 × 10^12/L (P < 0.05).

CONCLUSION

RBC counts below 4.56 × 10^12/L serve as a protective factor against DVT, while counts above this threshold pose a risk. These findings could inform the development of DVT prevention strategies for patients with SCI, emphasizing the need for targeted monitoring and management of RBC counts.

Assessment of the CLOT (children's likelihood of thrombosis) real-time risk prediction model of hospital-associated venous thromboembolism in children with congenital heart disease

BACKGROUND

Children with congenital heart disease (CHD) are at high risk for hospital-associated venous thromboembolism (HA-VTE). The children's likelihood of thrombosis (CLOT) trial validated a real-time predictive model for HA-VTE using data extracted from the EHR for pediatric inpatients. We tested the hypothesis that addition of CHD specific data would improve model prediction in the CHD population.

METHODS

Model performance in CHD patients from 2010 to 2022, was assessed using 3 iterations of the CLOT model: 1) the original CLOT model, 2) the original model refit using only data from the CHD cohort, and 3) the model updated with the addition of cardiopulmonary bypass time, STAT Mortality Category, height, and weight as covariates. The discrimination of the three models was quantified and compared using AUROC.

RESULTS

Our CHD cohort included 1457 patient encounters (median 2.0 IQR [0.5-5.2] years-old). HA-VTE was present in 5% of our CHD cohort versus 1% in the general pediatric population. Several features from the original model were associated with thrombosis in the CHD cohort including younger age, thrombosis history, infectious disease consultation, and EHR coding of a central venous line. Lower height and weight were associated with thrombosis. HA-VTE rate was 12% (18/149) amongst those with STAT Category 4-5 operation versus 4% (49/1256) with STAT Category 1-3 operation (P < .001). Longer cardiopulmonary bypass time (124 [92-205] vs. 94 [65-136] minutes, P < .001) was associated with thrombosis. The AUROC for the original (0.80 95% CI [0.75-0.85]), refit (0.85 [0.81-0.89]), and updated (0.86 [0.81-0.90]) models demonstrated excellent discriminatory ability within the CHD cohort.

CONCLUSION

The automated approach with EHR data extraction makes the applicability of such models appealing for ease of clinical use. The addition of cardiac specific features improved model discrimination; however, this benefit was marginal compared to refitting the original model to the CHD cohort. This suggests strong predictive generalized models, such as CLOT, can be optimized for cohort subsets without additional data extraction, thus reducing cost of model development and deployment.

The relationship between red cell distribution width, serum calcium ratio, and in-hospital mortality among patients with acute respiratory failure: A retrospective cohort study of the MIMIC-IV database

To investigate the impact of RDW/CA (the ratio of red cell distribution width to calcium) on in-hospital mortality in patients with acute respiratory failure (ARF). This retrospective cohort study analyzed the data of 6981 ARF patients from the Medical Information Mart for Intensive Care (MIMIC-IV) database 2.0. Critically ill participants between 2008 and 2019 at the Beth Israel Deaconess Medical Center in Boston. The primary outcome of interest was in-hospital mortality. A Cox proportional hazards regression model was used to determine whether the RDW/CA ratio independently correlated with in-hospital mortality. The Kaplan-Meier method was used to plot the survival curves of the RDW/CA. Subgroup analyses were performed to measure the mortality across various subgroups. After adjusting for potential covariates, we found that a higher RDW/CA was associated with an increased risk of in-hospital mortality (HR = 1.17, 95% CI: 1.01-1.35, P = .0365) in ARF patients. A nonlinear relationship was observed between RDW/CA and in-hospital mortality, with an inflection point of 1.97. When RDW/CA ≥ 1.97 was positively correlated with in-hospital mortality in patients with ARF (HR = 1.554, 95% CI: 1.183-2.042, P = .0015). The Kaplan-Meier curve indicated the higher survival rates for RDW/CA < 1.97 and the lower for RDW/CA ≥ 1.97 after adjustment for age, gender, body mass index, and ethnicity. RDW/CA is an independent predictor of in-hospital mortality in patients with ARF. Furthermore, a nonlinear relationship was observed between RDW/CA and in-hospital mortality in patients with ARF.

Discrimination of the acute pulmonary embolism subtypes based on the novel MAPH score

Acute pulmonary embolism (APE) is a thromboembolism situation that can be central or peripheral. APE risk analysis and classification are essential for therapy planning. Our aim is to determine the novel MAPH score (including age, mean platelet volume (MPV), total protein, and hematocrit parameters) that can distinguish APE subtypes. Our retrospective cohort analysis includes 97 APE patients referred to the emergency medicine department who underwent pulmonary computed tomography angiography (CTA) in 24 h from 2020 to 2022. The hospital information system provided demographic, clinical, laboratory, and pulmonary CTA data. APE was classified into central (46 patients) and peripheral (51 patients) depending on the area of vascular involvement. The central APE group had higher hypertension (HT) (67.4%) and atrial fibrillation (AF) (39.1%) incidence than the peripheral APE group (all p values > 0.05). The central APE had higher total protein and platelet counts (p = 0.003 and p = 0.036), but peripheral APE had higher troponin values (p = 0.029). Central APE had 2.17 ± 0.85 MAPH and peripheral APE 1.76 ± 0.95 (p = 0.029). HT, AF, platelet count, and MAPH score differed significantly in univariate logistic regression (all p values < 0.05). However, only platelet count varied in multivariate logistic regression (p = 0.042). ROC curve analysis revealed that the MAPH score predicts central APE with 83% sensitivity and 45% specificity at a cut-off level of 1.5. The new MAPH score as an indicator of blood viscosity may distinguish between central and peripheral APE. Our result is significant, especially for centers with limited examinations, as it may accelerate the diagnosis and treatment processes. We think that our results might guide future investigations.

Association of red cell distribution width/albumin ratio and in hospital mortality in patients with atrial fibrillation base on medical information mart for intensive care IV database

BACKGROUND

Atrial fibrillation (AF) is a common cardiac arrhythmia. The ratio of red cell distribution width (RDW) to albumin has been recognized as a reliable prognostic marker for poor outcomes in a variety of diseases. However, the evidence regarding the association between RDW to albumin ratio (RAR) and in hospital mortality in patients with AF admitted to the Intensive Care Unit (ICU) currently was unclear. The purpose of this study was to explore the association between RAR and in hospital mortality in patients with AF in the ICU.

METHODS

This retrospective cohort study used data from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database for the identification of patients with atrial fibrillation (AF). The primary endpoint investigated was in-hospital mortality. Multivariable-adjusted Cox regression analysis and forest plots were utilized to evaluate the correlation between the RAR and in-hospital mortality among patients with AF admitted to ICU. Additionally, receiver operating characteristic (ROC) curves were conducted to assess and compare the predictive efficacy of RDW and the RAR.

RESULTS

Our study included 4,584 patients with AF with a mean age of 75.1 ± 12.3 years, 57% of whom were male. The in-hospital mortality was 20.3%. The relationship between RAR and in-hospital mortality was linear. The Cox proportional hazard model, adjusted for potential confounders, found a high RAR independently associated with in hospital mortality. For each increase of 1 unit in RAR, there is a 12% rise in the in-hospital mortality rate (95% CI 1.06-1.19). The ROC curves revealed that the discriminatory ability of the RAR was better than that of RDW. The area under the ROC curves (AUCs) for RAR and RDW were 0.651 (95%CI: 0.631-0.671) and 0.599 (95% CI: 0.579-0.620).

CONCLUSIONS

RAR is independently correlated with in hospital mortality and in AF. High level of RAR is associated with increased in-hospital mortality rates.

Evaluation of Hemogram Parameters in the Diagnosis of Pulmonary Embolism: Immature Granulocytes and Other New Tips

Pulmonary embolism (PE) is an important cause of sudden death and is difficult to diagnose. Therefore unnecessary radiological investigations are often resorted to. Although some inflammatory parameters in the hemogram have been found to play a role in the diagnosis of PE, many parameters have not been adequately investigated. We aimed to evaluate potential inflammatory parameters in hemogram in the diagnosis of PE and to determine the parameters with the highest diagnostic value. This single-center, retrospective study was performed by evaluating 114 cases with suspected PE admitted to the emergency department between January 2017 and June 2022. Among 114 cases, 62 cases with a definitive diagnosis of PE by pulmonary computed tomography angiography served as the PE group and 52 cases without PE served as the control group. Admission hemogram parameters of both groups were recorded. Potential chronic diseases and acute conditions affecting hemogram were excluded from the study. In the multivariate model; immature granulocyte (IG), neutrophil/lymphocyte ratio (NLR), monocyte % and platelet large cell ratio (P-LCR) were found to be significantly and independently effective in differentiating cases with and without PE (P˂.05). Our findings suggest that high IG, high NLR, high monocyte %, and low P-LCR values have diagnostic value in cases with suspected PE. However the usability of IGs in the diagnosis of PE is a new finding. Hemogram is cheap, easily accessible, and potential inflammatory biomarkers in hemograms may increase physicians' awareness in the diagnosis of PE.

Relationship between the Ratio of Red Cell Distribution Width to Albumin and 28-Day Mortality among Chinese Patients over 80 Years with Atrial Fibrillation

INTRODUCTION

Atrial fibrillation (AF) is a prevalent heart arrhythmia in elderly adults aged 80 years or older. The red cell distribution width (RDW) to albumin ratio has been acknowledged as a reliable prognostic marker for poor outcomes in a variety of disorders. However, there exists limited scientific evidence on the association of RDW to albumin (RAR) with mortality in geriatric individuals with AF.

METHODS

From January 2015 to June 2020, a retrospective study was conducted in a tertiary academic institution that diagnosed 1,141 elderly adults with AF. The RAR value was calculated as the ratio of RDW (%) to albumin (g/dL). The potential association between RAR and cardiovascular mortality and the risk of all-cause mortality within 28 days was evaluated by means of multivariable Cox regression analysis.

RESULTS

The 28-day all-cause and cardiovascular mortality rates were 8.7% and 3.3%, respectively. Increased RAR tertiles were found to be significantly associated with greater all-cause mortality (T1: 1.6%; T2: 6.2%; T3: 18.1%, p < 0.001) and cardiovascular mortality (T1: 0.8%; T2: 2.9%; T3: 6.3%, p < 0.001) using Kaplan-Meier analysis. Continuous RAR had a positive association with all-cause mortality (hazard ratios [HR] = 1.42, 95% confidence interval [CI] 1.23-1.65) and cardiovascular mortality (HR = 1.31, 95% CI: 1.05-1.64), even after accounting for numerous confounding variables. In comparison to the T1 group, individuals with the highest RAR levels displayed a greater risk of all-cause mortality (HR = 2.73, 95% CI: 1.11-6.74) and cardiovascular mortality (HR = 2.59, 95% CI: 0.69-9.78). Increased RAR levels were related to higher rates of cardiovascular and all-cause mortality across almost all subgroups.

CONCLUSION

RAR is independently correlated with 28-day all-cause mortality and cardiovascular mortality in AF-affected individuals aged ≥80.

Red Cell Distribution Width as a Prognostic Indicator for Mortality and ICU Admission in Patients with COVID-19

BACKGROUND

COVID-19 disease caused by the SARS-CoV-2 virus can lead to an acute respiratory illness with a high hospitalization and mortality risk. Therefore, prognostic indicators are essential for early interventions. As a component of complete blood counts, the coefficient of variation (CV) of red blood cell distribution width (RDW) reflects cellular volume variations. It has been shown that RDW is associated with increased mortality risk in a wide range of diseases. This study aimed to determine the relationship between RDW and mortality risk in COVID-19 patients.

METHODS

This retrospective study was performed on 592 patients admitted to hospital between February 2020 and December 2020. Patients were divided into low and high RDW groups and the relationship between RDW and mortality, intubation, admission to intensive care unit (ICU), and need for oxygen therapy was investigated.

RESULTS

The mortality rate in the low RDW group was 9.4%, while that in the high group was 20% (p < 0.001). Also, ICU admission in the low group was 8%, whereas this was 10% in the high RDW group (p = 0.040). The results of the Kaplan-Meyer curve showed that the survival rate was higher in the low group compared to the high RDW group. Cox results in the crude model showed that higher RDW values were directly related to increased mortality, although this was not significant after adjustment for other covariates.

CONCLUSION

The results of our study reveal that high RDW is associated with increased hospitalization and risk of death and that RDW may be a reliable indicator of COVID-19 prognosis.

Nomogram for Predicting Postoperative Portal Venous Systemic Thrombosis in Patients with Cirrhosis Undergoing Splenectomy and Esophagogastric Devascularization

OBJECTIVES

The aim of the study is to develop a nomogram for predicting postoperative portal venous systemic thrombosis (PVST) in patients with cirrhosis undergoing splenectomy and esophagogastric devascularization.

METHODS

In total, 195 eligible patients were included. Demographic characteristics were collected, and the results of perioperative routine laboratory investigations and ultrasound examinations were also recorded. Blood cell morphological traits, including the red cell volume distribution width (RDW), mean platelet volume, and platelet distribution width, were identified. Univariate and multivariate logistic regressions were implemented for risk factor filtration, and an integrated nomogram was generated and then validated using the bootstrap method.

RESULTS

A color Doppler abdominal ultrasound examination on a postoperative day (POD) 7 (38.97%) revealed that 76 patients had PVST. The results of the multivariate logistic regression suggested that a higher RDW on POD3 (RDW3) (odds ratio (OR): 1.188, 95% confidence interval (CI): 1.073-1.326), wider portal vein diameter (OR: 1.387, 95% CI: 1.203-1.642), history of variceal hemorrhage (OR: 3.407, 95% CI: 1.670-7.220), and longer spleen length (OR: 1.015, 95% CI: 1.001-1.029) were independent risk parameters for postoperative PVST. Moreover, the nomogram integrating these four parameters exhibited considerable capability in PVST forecasting. The nomogram's receiver operating characteristic curve reached 0.83 and achieved a sensitivity and specificity of 0.711 and 0.848, respectively, at its cutoff. The nomogram's calibration curve demonstrated that it was well calibrated.

CONCLUSION

The nomogram exhibited excellent performance in PVST prediction and might assist surgeons in identifying vulnerable patients and administering timely prophylaxis.

Blood Cells and Venous Thromboembolism Risk: A Two-Sample Mendelian Randomization Study

Background

Previous studies have shown that various cell indices are associated with a higher risk of venous thromboembolism (VTE), however, whether these findings reflect a causal relationship remains unclear. Therefore, we performed a two-sample Mendelian randomization (MR) analysis to assess the causal association of various blood cells with VTE risk.

Study Design and Methods

Summary statistics of genetic instruments representing cell indices for erythrocytes, leukocytes, and platelets were extracted from genome-wide association studies of European ancestry, by Two-Sample Mendelian Randomization. Inverse variance weighting (IVW) was used as the primary analytical method for MR. Sensitivity analyses were performed to detect horizontal pleiotropy and heterogeneity.

Results

Genetically predicted red blood cell distribution width, mean reticulocyte volume, and mean red blood cell volume were positively associated with VTE, with odds ratio (OR) of 1.002 [CI 1.000-1.003, P = 0.022), 1.003 (CI 1.001-1.004, P = 0.001, respectively)] and 1.001 (CI 1.000-1.002, P = 0.005). Genetically predicted monocyte count was negatively correlated with VTE, with OR = 0.998 (CI 0.996-0.999, P = 0.041).

Conclusion

Genetically liability to high- red blood cell distribution width, mean reticulocyte volume, mean red blood cell volume, and low monocyte count are associated with the higher risk of VTE. Targeting these factors might be a potential strategy to prevent VTE.

Preoperative hemoglobin-to-red cell distribution width ratio as a prognostic factor in pulmonary large cell neuroendocrine carcinoma: a retrospective cohort study

Background

The hemoglobin (Hgb)/red cell distribution width (RDW) ratio (HRR) is a simple prognostic marker for small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC), but no data are available for pulmonary large cell neuroendocrine carcinoma (PLCNEC). This study aimed to assess the potential prognostic role of preoperative HRR in PLCNEC.

Methods

This single-center retrospective study included patients with PLCNEC who underwent surgery at Shanghai Pulmonary Hospital from January 2012 to August 2016. The follow-up was censored in August 2020. The participants were grouped as low/high HRR according to their optimal value calculated using a receiver operating characteristic (ROC) curve. Univariable and multivariable Cox analysis were performed to identify the risk factors for overall survival (OS).

Results

A total of 80 patients with PLCNEC were included. The optimal cutoff values were 0.969 for HRR. Compared with the high HRR group, the low HRR group had a lower mean Hgb (12.1 vs. 14.1 g/dL, P<0.001), lower mean albumin-globulin ratio (AGR) (1.4 vs. 1.6, P=0.017), and higher median RDW (14.5% vs. 12.9%, P<0.001). The median OS was 30.0 months [95% confidence interval (CI): 13.4 to 46.5 months]. Participants in the low HRR group exhibited a poorer OS than those with high HRR (20.3 months, 95% CI: 14.5 to 26.1 months vs. not reached, P<0.001). The multivariable analysis showed that low HRR was significantly associated with poor OS [hazard ratio (HR) =3.16, 95% CI: 1.69 to 5.93, P<0.001].

Conclusions

Low HRR is associated with poor OS in patients with PLCNEC and can be used as an inexpensive prognostic factor in patients undergoing PLCNEC resection.

The red blood cell distribution width-albumin ratio: A promising predictor of mortality in heart failure patients - A cohort study

BACKGROUND

Epidemiological studies suggest that increases in red blood cell distribution width (RDW) and decreases in albumin level can independently predict adverse cardiovascular outcomes. The prognostic value of RDW-albumin ratio (RAR), an innovate biomarker of inflammation, in heart failure (HF) patients has not been assessed. This study aimed to explore the association between RAR and mortality of HF patients.

METHODS

Data on patients diagnosed with HF were extracted from MIMIC-III database version 1.4. Cox proportional hazards models were used to investigate the associations between RAR and mortality of HF patients. HF patients admitted to the Second Affiliated Hospital of Wenzhou Medical University were also enrolled to explore the relationship between RAR and existing indicators of HF.

RESULTS

For 90-day mortality, the HR (95% CI) for the second (4.33＜RAR＜5.44) and the third (RAR＞5.44) tertiles were 2.00 (1.58, 2.54) and 3.63 (2.91, 4.53), respectively, compared to the first tertile (RAR＜4.33). When adjusted for age, gender and ethnicity in Model 1, the adjusted HR (95% CI) value of third tertiles was 3.66 (2.93, 4.56). Further adjust the vital signs, blood biochemical indicators, SOFA score and other parameters in Model II, the adjusted HR value of third tertiles was still statistically significant (HR: 2.70, 95% CI: 2.07-3.51, P < 0.0001). A similar trend was observed for 30-day, one-year mortality. For HF patients, high RAR significantly increased the risk of sepsis and requirement for renal replacement therapy. Additionally, there is a positive correlation between RAR, CRP levels, and NT-proBNP respectively.

CONCLUSION

High level of RAR is associated with increased short- and long-term mortality of patients with heart failure. The RAR is a promising biomarker that is easy to obtain and readily predicts mortality in heart failure patients.

ΔRDW: A Novel Indicator with Predictive Value for the Diagnosis and Treatment of Multiple Diseases

Elevated red blood cell distribution width (RDW) is a powerful predictor of poor prognosis in a variety of diseases, but a single measurement of RDW cannot reflect the dynamic change of diseases. ΔRDW, as a risk stratification tool, can be used to record changes in RDW before and after treatment; also, it allows investigators to name the unit change of RDW in the studied population. So far, there have been few relevant studies on the predictive value of ΔRDW for different diseases; this article aims to review the studies and summaries of the current understandings on the correlation between ΔRDW and disease outcomes.

The prevalence and clinical features of pulmonary embolism in patients with AE-COPD: A meta-analysis and systematic review

BACKGROUND

The prevalence of pulmonary embolism (PE) in the acute exacerbation of chronic obstructive pulmonary disease (AE-COPD) is highly controversial. We conducted a systematic review and meta-analysis to summarize the epidemiology and characteristics of PE with AE-COPD for current studies.

METHODS

We searched the PubMed, EMBASE, Cochrane Library and Web of Science databases for studies published prior to October 21, 2020. Pooled proportions with 95% confidence intervals (95% CIs) were calculated using a random effects model. Odds ratios (ORs) and mean differences (MDs) with 95% confidence intervals were used as effect measures for dichotomous and continuous variables, respectively.

RESULTS

A total of 17 studies involving 3170 patients were included. The prevalence of PE and deep vein thrombosis (DVT) in AE-COPD patients was 17.2% (95% CI: 13.4%-21.3%) and 7.1% (95% CI: 3.7%-11.4%%), respectively. Dyspnea (OR = 6.77, 95% CI: 1.97-23.22), pleuritic chest pain (OR = 3.25, 95% CI: 2.06-5.12), lower limb asymmetry or edema (OR = 2.46, 95% CI:1.51-4.00), higher heart rates (MD = 20.51, 95% CI: 4.95-36.08), longer hospital stays (MD = 3.66, 95% CI: 3.01-4.31) were associated with the PE in the AE-COPD patients. Levels of D-dimer (MD = 1.51, 95% CI: 0.80-2.23), WBC counts (MD = 1.42, 95% CI: 0.14-2.70) were significantly higher and levels of PaO2 was lower (MD = -17.20, 95% CI: -33.94- -0.45, P<0.05) in the AE-COPD with PE group. The AE-COPD with PE group had increased risk of fatal outcome than the AE-COPD group (OR = 2.23, 95% CI: 1.43-3.50).

CONCLUSIONS

The prevalence of PE during AE-COPD varies considerably among the studies. AE-COPD patients with PE experienced an increased risk of death, especially among the ICU patients. Understanding the potential risk factors for PE may help clinicians identify AE-COPD patients at increased risk of PE.

PROSPERO REGISTRATION NUMBER

CRD42021226568.

Predictive Value of Red Blood Cell Distribution Width in Poststroke Depression

Purpose

Red blood cell distribution width (RDW) is increased in a variety of inflammatory-related diseases. However, there is no report of its clinical significance in poststroke depression (PSD). This study explores the clinical significance of RDW in PSD patients.

Methods

A total of 185 patients with first-ever acute ischaemic stroke (AIS) in the Second Hospital of Anhui Medical University were chosen as subjects. A retrospective observational study was conducted from February 2019 to February 2020. PSD patients were diagnosed at 6 months after stroke based on the Diagnostic and Statistical Manual of Mental Disorders-IV criteria. Clinical and laboratory data were obtained from all patients. Coefficient of Variation (RDW-CV) and standard deviation (RDW-SD) were used to statistically report the performance of red blood cell distribution width.

Results

At the 6-month follow-up, 46 patients were diagnosed with PSD. Compared with non-PSD patients, PSD patients exhibited an increase in RDW-CV and RDW-SD, which positively correlated with serum interleukin 6 (IL-6) concentrations. In PSD patients, only RDW-SD demonstrated a consistent positive association with the Hamilton Rating Scale for Depression (HAM-D) scores at 6 months after admission. RDW-CV, RDW-SD, and IL-6 were recognized as independent predictors of PSD. The area under the receiver operating characteristic (ROC) curve (AUC) of RDW-SD was 0.796 (95% CI: 0.731-0.852) for the prediction of PSD, which was superior to that of RDW-CV. The specificity for predicting PSD was 60.43%, and the sensitivity was 91.30% if RDW-SD was higher than 43.80 fL.

Conclusions

RDW-SD is a simple, inexpensive, rapid, and easily accessible parameter that can be used to predict PSD in patients with stroke.

Prediction of venous thromboembolism with machine learning techniques in young-middle-aged inpatients

Accumulating studies appear to suggest that the risk factors for venous thromboembolism (VTE) among young-middle-aged inpatients are different from those among elderly people. Therefore, the current prediction models for VTE are not applicable to young-middle-aged inpatients. The aim of this study was to develop and externally validate a new prediction model for young-middle-aged people using machine learning methods. The clinical data sets linked with 167 inpatients with deep venous thrombosis (DVT) and/or pulmonary embolism (PE) and 406 patients without DVT or PE were compared and analysed with machine learning techniques. Five algorithms, including logistic regression, decision tree, feed-forward neural network, support vector machine, and random forest, were used for training and preparing the models. The support vector machine model had the best performance, with AUC values of 0.806-0.944 for 95% CI, 59% sensitivity and 99% specificity, and an accuracy of 87%. Although different top predictors of adverse outcomes appeared in the different models, life-threatening illness, fibrinogen, RBCs, and PT appeared to be more consistently featured by the different models as top predictors of adverse outcomes. Clinical data sets of young and middle-aged inpatients can be used to accurately predict the risk of VTE with a support vector machine model.

A Real-time Risk-Prediction Model for Pediatric Venous Thromboembolic Events

BACKGROUND

Hospital-associated venous thromboembolism (HA-VTE) is an increasing cause of morbidity in pediatric populations, yet identification of high-risk patients remains challenging. General pediatric models have been derived from case-control studies, but few have been validated. We developed and validated a predictive model for pediatric HA-VTE using a large, retrospective cohort.

METHODS

The derivation cohort included 111 352 admissions to Monroe Carell Jr. Children's Hospital at Vanderbilt. Potential variables were identified a priori, and corresponding data were extracted. Logistic regression was used to estimate the association of potential risk factors with development of HA-VTE. Variable inclusion in the model was based on univariate analysis, availability in routine medical records, and clinician expertise. The model was validated by using a separate cohort with 44 138 admissions.

RESULTS

A total of 815 encounters were identified with HA-VTE in the derivation cohort. Variables strongly associated with HA-VTE include history of thrombosis (odds ratio [OR] 8.7; 95% confidence interval [CI] 6.6-11.3; P < .01), presence of a central line (OR 4.9; 95% CI 4.0-5.8; P < .01), and patients with cardiology conditions (OR 4.0; 95% CI 3.3-4.8; P < .01). Eleven variables were included, which yielded excellent discriminatory ability in both the derivation cohort (concordance statistic = 0.908) and the validation cohort (concordance statistic = 0.904).

CONCLUSIONS

We created and validated a risk-prediction model that identifies pediatric patients at risk for HA-VTE development. We anticipate early identification of high-risk patients will increase prophylactic interventions and decrease the incidence of pediatric HA-VTE.

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.

Predictive Value of Red Blood Cell Distribution Width in Chronic Obstructive Pulmonary Disease Patients with Pulmonary Embolism

Purpose

This study is aimed at investigating the relationship between red cell distribution width (RDW) and chronic obstructive pulmonary disease (COPD) patients with pulmonary embolism (PE).

Methods

We conducted a retrospective study enrolling a total of 125 patients from January 2013 to December 2019. The study group consisted of 40 COPD patients with PE, and the control group had 85 COPD patients without PE. Clinical data including demographic characteristics, comorbidities, and results of imaging examinations and laboratory tests were recorded. Blood biomarkers, including red blood cell distribution width standard deviation (RDW-SD), red blood cell distribution width coefficient of variation (RDW-CV), and D-Dimer, were included.

Results

RDW-SD and RDW-CV were higher in the COPD patients with the PE group (p < 0.001). A higher RDW-SD led to a significantly increased risk of PE than a lower RDW-SD (adjusted odds ratio (OR): 1.188; 95% confidence interval (CI): 1.048-1.348). The area under the curve (AUC) of RDW-SD used for predicting PE was 0.737. Using 44.55 as the cutoff value of RDW-SD, the sensitivity was 80% and the specificity was 64.7%. The prediction accuracy of RDW-SD combined with D-Dimer (AUC = 0.897) was higher than that of RDW-SD or D-Dimer alone. The optimal cutoff value of RDW-SD+D-Dimer for predicting PE was 0.266, which generated a sensitivity of 87.5% and specificity of 83.5%.

Conclusion

RDW is significantly increased in COPD patients with PE and may thus be useful in predicting the occurrence of PE in patients with COPD.

Risk of Stroke in Patients With Patent Foramen Ovale Who Had Pulmonary Embolism

Background

The presence of patent foramen ovale (PFO) alone does not increase the risk of ischemic stroke. Several prospective studies with a small number of patients have shown that the risk of ischemic stroke is higher in patients with PFO and pulmonary embolism (PE). We studied the association of ischemic stroke in the patients who had PFO with PE (PFOwiPE) and compared with the patients who had PFO without PE (PFOwoPE).

Methods

Electronic medical records of 154 adult patients in our internal medicine office were reviewed. Thirty-four patients had PFOwiPE and 120 had PFOwoPE. Independent t-test and Mann-Whitney U-test were used to compare the continuous variables between the two groups, while Chi-square tests were applied to compare the categorical variables between the two groups. Logistic regression was used for multivariate analysis. The dependent variable was stroke and the independent variable of interest was PFO with, or without PE.

Results

Mean age of patients with PFOwiPE was 54.8 years and patients with PFOwoPE was 57.8 years (P = 0.331). Mean body mass index (BMI) of the patients with PFOwiPE was significantly greater than the patients with PFOwoPE (32.5 ± 8.84 kg/m² vs. 28.4 ± 6.99 kg/m²; P < 0.05). Mean left ventricular ejection fraction (LVEF) and red blood cell (RBC) count of patients with PFOwiPE was significantly lower than patients with PFOwoPE (LVEF 54.9 ± 13.01% vs. 59.6 ± 6.85%, P < 0.05; RBC 4.1 ± 1.203 × 10⁶/µL vs. 4.5 ± 0.596 × 10⁶/µL, P < 0.05). There was significantly higher association of congestive heart failure (CHF) in patients with PFOwiPE compared to patients with PFOwoPE (20.6% vs. 7.5%; P < 0.05). Association of ischemic stroke was 35.3% in patients with PFOwiPE and 39.2% in patients with PFOwoPE. The difference was not statistically significant (P = 0.682).

Conclusions

Association of ischemic stroke was similar in patients with PFOwiPE and patients with PFOwoPE. Association of significantly higher BMI, lower LVEF, lower RBC count, and higher frequency of CHF were associated with patients with PFOwiPE compared to the patients with PFOwoPE.