Inflammatory Biomarkers in the Short-Term Prognosis of Venous Thromboembolism: A Narrative Review

Astragaloside IV induces endothelial progenitor cell angiogenesis in deep venous thrombosis through inactivation of PI3K/AKT signaling

BACKGROUND

Deep vein thrombosis (DVT), referred to as venous thromboembolism, is the third most frequent cardiovascular disease. Endothelial progenitor cells (EPCs) contribute to the recanalization of DVT. Astragaloside IV (AS-IV) has been suggested to have angiogenesis-enhancing effects. Here, we investigate the roles and mechanisms of AS-IV in EPCs and DVT.

METHODS

The experimental DVT model was established by inferior vena cava stenosis in rats. EPCs were collected from patients with DVT. Transwell assays were performed to detect cell migration. Tube formation was determined using Matrigel basement membrane matrix and ImageJ software. The thrombus weight and length were measured. Pathological changes were examined by hematoxylin-eosin staining. The production of proinflammatory cytokines was estimated by ELISA. The level of PI3K/AKT-related proteins was measured by western blotting.

RESULTS

AS-IV administration facilitated the migrative and angiogenic functions of human EPCs in vitro. Additionally, AS-IV inhibited thrombosis and repressed the infiltration of leukocytes into the thrombus and the production of proinflammatory cytokines in rats. Mechanistically, AS-IV inactivated PI3K/AKT signaling in rats.

CONCLUSION

AS-IV prevents thrombus in an experimental DVT model by facilitating EPC angiogenesis and decreasing inflammation through inactivation of PI3K/AKT signaling.

Evaluation of soluble P-selectin as a predictive biomarker in acute symptomatic pulmonary embolism: Insights from a prospective observational study

BACKGROUND

Soluble P-selectin (sP-selectin) has been proposed as a potential biomarker for venous thromboembolism (VTE) diagnosis with interesting results. However, its role in predicting early mortality in pulmonary embolism (PE) remains unexplored.

METHODS

This observational, prospective, single-center study enrolled consecutive patients aged 18 or older with confirmed acute symptomatic PE and no prior anticoagulation. The study aims to assess the prognostic capacity of sP-selectin measured at the time of PE diagnosis for short-term mortality and major bleeding.

RESULTS

A total of 196 patients, with a mean age of 69.1 years (SD 17), were included, of whom 52.6% were male. Within 30 days, 9.7% of patients (n = 19) died, and 5.1% (n = 10) suffered major bleeding. PE risk stratification revealed 4.6% (n = 9) with high-risk PE, 34.7% (n = 68) with intermediate-high-risk PE, 38.3% (n = 75) with intermediate-low-risk PE, and 22.5% (n = 44) with low-risk PE according to the European Society of Cardiology score. Mean plasma sP-selectin levels were comparable between survivors and non-survivors (489.7 ng/mL ±63 vs. 497.3 ng/mL ±51; p = .9). The ROC curve for 30-day all-cause mortality and major bleeding yielded an AUC of 0.49 (95% CI 0.36-0.63) and 0.46 (95% CI 0.24-0.68), respectively. Multivariate and survival analyses were precluded due to lack of significance.

CONCLUSIONS

sP-selectin was not useful for predicting short-term mortality or major bleeding in patients with acute symptomatic pulmonary embolism. Further studies are required to clarify the role of sP-selectin in VTE, particularly in prognosticating PE outcomes.

Hot under the clot: venous thrombogenesis is an inflammatory process

ABSTRACT

Venous thrombosis (VT) is a serious medical condition in which a blood clot forms in deep veins, often causing limb swelling and pain. Current antithrombotic therapies carry significant bleeding risks resulting from targeting essential coagulation factors. Recent advances in this field have revealed that the cross talk between the innate immune system and coagulation cascade is a key driver of VT pathogenesis, offering new opportunities for potential therapeutic interventions without inducing bleeding complications. This review summarizes and discusses recent evidence from preclinical models on the role of inflammation in VT development. We highlight the major mechanisms by which endothelial cell activation, Weibel-Palade body release, hypoxia, reactive oxygen species, inflammasome, neutrophil extracellular traps, and other immune factors cooperate to initiate and propagate VT. We also review emerging clinical data describing anti-inflammatory approaches as adjuncts to anticoagulation in VT treatment. Finally, we identify key knowledge gaps and future directions that could maximize the benefit of anti-inflammatory therapies in VT. Identifying and targeting the inflammatory factors driving VT, either at the endothelial cell level or within the clot, may pave the way for new therapeutic possibilities for improving VT treatment and reducing thromboembolic complications without increasing bleeding risk.

Soluble urokinase type plasminogen activator receptor (suPAR) and mortality in acute pulmonary embolism

INTRODUCTION

The soluble urokinase-type plasminogen activator receptor (suPAR) potentially plays a role in immune-thrombosis, possibly by modulating plasmin activity or contributing to chemotaxis in a complex, poorly understood context. The role of suPAR levels in the short-term prognostic of patients with pulmonary embolism (PE) has not been evaluated.

MATERIAL AND METHODS

This observational, prospective, single-center study enrolled consecutive patients aged 18 and above with confirmed acute symptomatic PE and no prior anticoagulant therapy. The primary objective was to assess the prognostic capacity of suPAR levels measured at the time of diagnosis in terms of mortality.

RESULTS

Fifty-two patients, with a mean age of 73.8 years (±17), were included, with gender distribution evenly split at 50%. Seven (13.5%) patients died. The ROC curve for mortality yielded an AUC of 0.72 (95% CI 0.48-0.96), with an optimal suPAR cut-off of 5.5ng/mL. Bivariate analysis for suPAR>5.5ng/mL was associated with a crude odds ratio of 10 (95% CI 1.63-61.27; p=0.01) for 30-day mortality. Survival analysis showed a 30-day mortality hazard ratio of 8.33 (95% CI 1.69-40.99; p<0.01).

CONCLUSION

suPAR emerges as a potential biomarker for short-term mortality prediction and holds the potential for enhanced stratification in patients with acute symptomatic PE.

Real-world Safety and Effectiveness of Edoxaban in Patients with Venous Thromboembolism with or without Preceding Parenteral Anticoagulants: A Single-center Retrospective Study

Objective Edoxaban is an anticoagulant used for venous thromboembolism (VTE) treatment and requires pretreatment with parenteral anticoagulants. However, pretreatment is not always performed in the clinical setting. In this study, we investigated the safety and effectiveness of edoxaban treatment in patients with VTE with or without pretreatment. Methods We retrospectively enrolled 364 patients who received edoxaban for VTE treatment between September 2014 and March 2020 and investigated patient demographics, VTE recurrence, and major bleeding as clinical outcomes in patients with or without pretreatment. Furthermore, the factors contributing to pretreatment decisions were assessed. Results Patients without pretreatment (n=208) had more active cancer cases and fewer pulmonary embolism complications than those with pretreatment (n=156). Lower levels of hemoglobin and higher levels of white blood cell counts, C-reactive protein, and D-dimer at the diagnosis were found in patients who received pretreatment than in those without pretreatment. No symptomatic VTE recurrence was observed. After propensity score matching, the cumulative incidence of major bleeding was not significantly higher in patients with pretreatment than in those without it (log-rank test, p=0.136). The incidence of deteriorated VTE on imaging did not significantly differ between patients with and without pretreatment, even after propensity matching (log-rank test, p=0.414). Conclusion In a real-world clinical setting, where physicians determined the use of parenteral anticoagulant lead-in according to their experience, patient demographics, and VTE characteristics, no significant differences were found regarding safety and effectiveness in edoxaban-treated VTE patients with or without pretreatment with parenteral anticoagulants.

The Potential Role of CA-125 as a Biomarker for Short-Term Mortality Risk in Patients with Acute Symptomatic Pulmonary Embolism

Background: Antigen carbohydrate 125 (CA-125) is a complex glycoprotein extensively studied as a prognostic biomarker in heart failure, yet its potential role in the short-term prognosis of an acute pulmonary embolism (PE) remains unexplored. Methods: In this observational, prospective, single-center study, consecutive patients aged 18 and older with a confirmed acute symptomatic PE and no history of prior anticoagulant therapy were enrolled. Primary and secondary objectives aimed to assess the prognostic capacity of CA-125 at PE diagnosis for 30-day mortality and major bleeding, respectively. Results: A total of 164 patients were included (mean age 69.8 years, SD 17), with 56.1% being male. Within 30 days, 17 patients (10.4%) died and 9 patients (5.5%) suffered major bleeding. ROC curve analysis for 30-day mortality yielded an area under the curve of 0.69 (95% CI 0.53-0.85) with an optimal CA-125 cut-off point of 20 U/mL and a negative predictive value of 96%. Multivariate analysis revealed a significant association between CA-125 levels exceeding 20 U/mL and 30-day mortality (adjusted odds ratio 4.95; 95% CI 1.61-15.2) after adjusting for age, cancer, NT-proBNP > 600 ng/mL, and the simplified pulmonary embolism severity index score. Survival analysis for 30-day mortality exhibited a hazard ratio of 5.47 (95% CI 1.78-16.8). No association between CA-125 levels and 30-day major bleeding was found. Conclusions: CA-125 emerges as a promising surrogate biomarker for short-term mortality prediction in an acute symptomatic PE. Future investigations should explore the integration of CA-125 into PE mortality prediction scores to enhance the prognostic accuracy in this patient population.

Venous thromboembolic outcomes in patients with lymphedema and lipedema: An analysis from the National Inpatient Sample

BACKGROUND

Patients with lymphedema and lipedema share physical exam findings that may lead to misdiagnosis. Poor mobility is common in patients with obesity and patients with lymphedema and lipedema. This may constitute a risk factor for venous thromboembolism (VTE). Our objective was to evaluate the association of VTE in obese patients with lymphedema and lipedema.

METHODS

The National Inpatient Sample (NIS) was searched from 2016 to 2020 to identify hospital admissions of obese female patients with lymphedema and lipedema. Patients were analyzed in the context of presence or absence of VTE while adjusting for complex cluster sampling techniques. Predictors of VTE were accessed by multivariable regression.

RESULTS

Lymphedema was identified in 189,985 patients and lipedema in 50,645 patients. VTE was observed in 3.12% (n = 374,210) of patients with obesity. In patients with obesity, VTE was more common in patients with lymphedema than without (2.6% vs 1.6%; p < 0.01). Similarly, VTE was more common in patients with lipedema than without (0.6% vs 0.4%; p < 0.01). After multivariable logistic regression, VTE events in obese patients with lymphedema were higher versus without (OR 1.6; CI 1.08-2.43; p = 0.02). Similarly, VTE events were more common in obese patients with lipedema versus obese patients without lipedema (OR 1.20; CI 1.03-1.41; p = 0.02).

CONCLUSIONS

In this hypothesis-generating study, lymphedema and lipedema show a positive association with VTE after adjusting for baseline patient characteristics such as obesity, which is a known independent risk factor for VTE. Mechanisms whereby lymphedema and lipedema are associated with VTE should be investigated.

Acute Pulmonary Embolism and Immunity in Animal Models

Venous thromboembolism, encompassing acute pulmonary embolism (APE) and deep vein thrombosis (DVT), is a potentially fatal disease with complex pathophysiology. Traditionally, the Virchow triad provided a framework for understanding the pathogenic contributors to thrombus formation, which include endothelial dysfunction, alterations in blood flow and blood hypercoagulability. In the last years, it has become apparent that immunity plays a central role in thrombosis, interacting with classical prothrombotic mechanisms, oxidative stress and vascular factors. Thrombosis amplifies inflammation, and exaggerated inflammatory processes can trigger thrombosis mainly due to the activation of leukocytes, platelets, and endothelial cells. APE-related endothelium injury is a major trigger for immune system activation. Endothelium is also a key component mediating inflammatory reaction and it is relevant to maintain vascular permeability. Exaggerated right ventricular wall stress and overload, with coexisting systemic hypotension and hypoxemia, result in myocardial injury and necrosis. Hypoxia, tissue factor activation and cytokine storm are engaged in the thrombo-inflammatory processes. Thrombus development is characterized by inflammatory state vascular wall caused mainly by an early extravasation of leukocytes and intense selectins and cytokines production. Nevertheless, immunity of DVT is well described, little is known about potential chemokine and cellular differences between thrombus that develops in the vein and thrombus that detaches and lodges in the pulmonary circulation being a cause of APE. There is a paucity of data considering inflammatory state in the pulmonary artery wall during an acute episode of pulmonary embolism. The main aim of this review is to summarize the knowledge of immunity in acute phase of pulmonary embolism in experimental models.

Adhesive properties of plasma-circulating and platelet-derived microvesicles from healthy individuals

BACKGROUND

Microvesicles (MVs) produced by platelets upon activation possess high procoagulant activity and represent a possible thrombotic risk marker. However, direct experimental evaluation of the adhesive properties of MVs and their potential role in thrombus growth is lacking.

OBJECTIVES

We investigated integrin αIIbβ3 status and adhesive properties of plasma-circulating and platelet-derived MVs from healthy individuals.

METHODS

MVs were isolated from whole blood or produced from activated platelets. Flow cytometry was used for quantification of fluorescently labeled PAC-1 and fibrinogen binding to MVs. Confocal microscopy was used for evaluation of MVs adhesion to fibrinogen and for estimation of their involvement in whole blood thrombus formation in a parallel-plate flow chambers under arterial shear conditions.

RESULTS AND CONCLUSIONS

Neither circulating plasma MVs, nor platelet-activation-produced MVs bound PAC-1. However, both types of MVs specifically and weakly bound fibrinogen (about 400 molecules of bound fibrinogen per MV versus >100,000 per non-procoagulant activated platelet). Still, the MVs did not adhere stably to the immobilized fibrinogen. Both types of MVs were weakly incorporated into a thrombus and did not affect thrombus formation: average thrombus height in the recalcified whole blood in the presence of platelet-activation-produced MVs was 4.19 ± 1.38 μm versus 4.87 ± 1.72 μm (n = 6, p > 0.05) in the control experiments. This suggests that MVs present in plasma of healthy individuals are not likely to be directly involved in thrombus formation under arterial flow conditions.

Utilization of a Novel Scoring System in Predicting 30-day Mortality in Acute Pulmonary Embolism, the CLOT-5 Pilot Study

OBJECTIVES

To construct a new scoring system utilizing biomarkers, vitals, and imaging data to predict 30-day mortality in acute pulmonary embolism (PE).

BACKGROUND

Acute PE, a well-known manifestation of venous thromboembolic disease, is responsible for over 100,000 deaths worldwide yearly. Contemporary management algorithms rely on a multidisciplinary approach to care via PE response teams (PERT) in the identification of low, intermediate, and high-risk patients. The PESI and sPESI scores have been used as cornerstones of the triage process in assigning risk of 30-day mortality for patients presenting with acute PE; however, the specificity of these scoring systems has often come into question.

METHODS

This study retrospectively analyzed 488 patients with acute PE who were managed at a tertiary care institution with either conservative therapy consisting of low molecular weight or unfractionated heparin, advanced therapies consisting of catheter directed therapies, aspiration thrombectomy, or a combination of these therapies, or surgical embolectomy. The CLOT-5 score was designed to include vital signs, biomarkers, and imaging data to predict 30-day mortality in patients presenting with acute PE.

RESULTS

The CLOT-5 score had an area under the curve (AUC) of 0.901 with a standard error of 0.29, while the PESI and sPESI scores had an AUC and standard errors of 0.793 ±- 0.43 and 0.728 ± 0.55, respectively.

CONCLUSIONS

When incorporated into the management algorithms of national PERT programs, the CLOT-5 score may allow for rapid and comprehensive assessment of patients with acute PE at high risk for clinical decompensation, leading to early escalation of care where appropriate.

Use of the RCOG risk assessment model and biomarkers to evaluate the risk of postpartum venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality during pregnancy and the puerperium. The vast majority of VTE occurs after childbirth. China has not yet established standard risk assessment model for postpartum venous thromboembolism (VTE), the Royal College of Obstetricians and Gynecologists (RCOG) risk assessment model (RAM) is commonly used in clinic at present. Herein, we aimed to evaluate the validity of the RCOG RAM in the Chinese population and try to formulate a local risk assessment model by combining with other biomarkers for VTE prophylaxis.

METHODS

The retrospective study was conducted from January 2019 to December 2021at Shanghai First Maternity and Infant Hospital which has approximately 30,000 births annually, and the incidence of VTE, differences between RCOG-recommended risk factors, and other biological indicators from medical records were evaluated.

RESULTS

The study included VTE (n = 146) and non-VTE(n = 413) women who examined by imaging for suspicion of postpartum VTE. There was no statistical difference in the incidence rate of postpartum VTE between the low-score group (23.8%) and the high-score group (28%) after stratification by RCOG RAM. However, we found that cesarean section (in the low-score group), white blood cell (WBC) ≥ 8.64*10^9/L (in the high-score group), low-density lipoprotein(LDL) ≥ 2.70 mmol/L, and D-dimer ≥ 3.04 mg/L (in both groups) were highly associated with postpartum VTE. Subsequently, the validity of the RCOG RAM combined with biomarkers as a model for the risk assessment of VTE was estimated and the results showed that this model has good accuracy, sensitivity, and specificity.

CONCLUSIONS

Our study indicated that the RCOG RAM was not the best strategy for predicting postpartum VTE. Combined with some biomarkers (including the value of LDL and D-Dimer, and WBC count), the RCOG RAM is more efficient when identifying high-risk groups of postpartum VTE in the Chinese population.

TRIAL REGISTRATION

This purely observational study does not require registration based on ICMJE guidelines.

[Clinical characteristics and presentation form in patients with venous thromboembolism and negative or weakly positive D-dimer]

INTRODUCTION

D-dimer has a high negative predictive value for the diagnosis of venous thromboembolic disease (VTE). However, VTE has been reported in the presence of normal D-dimer values.

METHODS

This is a prospective observational study in patients with VTE from Hospital Gregorio Marañón between 2001 and 2022, comparing the characteristics of clinical presentation based on D-dimer levels (<500 ng/mL vs. ≥500 ng/mL).

RESULTS

A total of 2582 patients were found, 333 patients (12.9%) presented negative or weakly positive D-dimer levels. They were significantly younger (57.9 vs. 65.3 years), with a lower prevalence of comorbidities (ischemic heart disease, dementia, and chronic kidney disease), and a greater family history of VTE (8.4% vs. 5.2%) and thrombophilia (11.7% vs. 7.8%). They presented significantly less dyspnea (57.6% vs. 75.4%), syncope (3% vs. 13.5%), less thrombotic load, elevated NT-pro-BNP (22.0% vs. 48.2%), and right ventricle dilatation (8.1% vs. 30.0%).

CONCLUSION

Patients with VTE and low D-dimer levels at diagnosis were younger, with milder clinical presentation and lower thrombotic load; but they presented a higher prevalence of thrombophilia and a family history of VTE.

Risk factors for totally implantable access ports-associated thrombosis in pediatric oncology patients

The application of totally implantable access ports (TIAPs) reduces treatment-related discomfort; however, the existence of catheter may cause side effects, with the most common one being the occurrence of TIAPs-associated thrombosis. The risk factors for TIAPs-associated thrombosis in pediatric oncology patients have not been fully described. A total of 587 pediatric oncology patients undergoing TIAPs implantation at a single center over a 5-year period were retrospectively analyzed in the present study. We investigated the risk factors for thrombosis, emphasizing the internal jugular vein distance, by measuring the vertical distance from the highest point of the catheter to the upper border of the left and right extremitas sternalis claviculae on chest X-ray images. Among 587 patients, 143 (24.4%) had thrombosis. Platelet count, C-reactive protein, and the vertical distance from the highest point of the catheter to the upper border of the left and right extremitas sternalis claviculae were demonstrated to be the main risk factors for the development of TIAPs-associated thrombosis. TIAPs-associated thrombosis, especially asymptomatic events, is common in pediatric cancer patients. The vertical distance from the highest point of the catheter to the upper border of the left and right extremitas sternalis claviculae was a risk factor for TIAPs-associated thrombosis, which deserved additional attention.

Venous thromboembolism: Why is it still a significant health problem?

BACKGROUND

Venous thromboembolism (VTE) remains the third leading cause of acute cardiovascular syndrome following myocardial infarction and ischemic stroke. The global burden of disease worldwide is high and shows a steady upward trend in recent years with an incidence of 1-2 per 1000 adults per year. The overarching goal of the initial management of VTE is to prevent early and late adverse outcomes. Rapid evaluation and therapeutic intervention is vital to improving prognosis.

METHODS

We searched PubMed, Science Direct and Scopus databases for articles published in the last 10 years. Additionally, some earlier articles were analyzed.

RESULTS

For the purposes of this review, we discussed how understanding the epidemiology of VTE and the current knowledge of early and late complications of this disease have shaped the current approach to VTE prevention. We also analyzed the current knowledge and the most up-to-date information about VTE in COVID-19 infection. Contemporary perspective presented in this article on mortality in VTE, the incidence of recurrences, the risk of major bleeding during therapy and the chronic complications indicate why this is a major challenge for today's medicine and a current target for further research.

CONCLUSIONS

Understanding the interaction between environmental and genetic factors appears to be crucial in the diagnostic process. It can provide insight into the pathophysiology of VTE, potentially identifying options for targeted prevention and treatment. However, due to differences in clinical presentation, diagnosing pulmonary embolism may not be an easy task which perfectly illustrates the scale and complexity of the disease.

Apelin-36 alleviates LPS-induced trophoblast cell injury by inhibiting GRP78/ASK1/JNK signaling

Pre-eclampsia (PE) is a type of hypertensive disorder of pregnancy that poses a serious threat to the health of both mother and fetus. Inhibition of the inflammatory environment on trophoblast cells is of great significance to improve PE. Apelin-36 is an endogenous active peptide with strong anti-inflammatory activity. Therefore, this study aims to investigate the effects of Apelin-36 on lipopolysaccharide (LPS)-induced trophoblast cells and its potential mechanism. The levels of inflammatory factors (TNF-α, IL-8, IL-6 and MCP-1) were detected by reverse transcription-quantitative PCR (RT-qPCR). The proliferation, apoptosis, migration and invasion capacities in trophoblast cells were detected by CCK-8, TUNEL staining, wound healing and Transwell assays, respectively. GRP78 was overexpressed by cell transfection. Western blot was applied for the identification of protein levels. Apelin concentration-dependently decreased the expression of inflammatory cytokines and p-p65 protein level in trophoblast cells induced by LPS. Apelin treatment reduced LPS-induced apoptosis and improved the proliferation, invasion and migration capacities of LPS-mediated trophoblast cells. Additionally, Apelin down-regulated GRP78, p-ASK1 and p-JNK protein levels. The inhibition on LPS-induced trophoblast cell apoptosis and the promotion on invasion and migration by Apelin-36 was counteracted by GRP78 overexpression. To sum up, Apelin-36 could alleviate LPS-induced cell inflammation and apoptosis and improve the invasion and migration of trophoblasts by inhibiting the GRP78/ASK1/JNK signaling.

Concentrations of selected acute phase proteins in patients with chronic venous insufficiency treated with Sulodexide. Part 1

Introduction

Chronic venous insufficiency (CVI) is a widespread and serious social problem. The pathogenesis of the disease is multifactorial and one of the important factors in its development is inflammation.

Aim

Assessment of the concentration of selected acute phase proteins: C-reactive protein (CRP) and α1 antitrypsin (AAT) in the blood serum of patients with CVI before and after treatment with Sulodexide.

Material and methods

The study was carried out in 88 people, including 39 clinically healthy subjects as the reference group and 49 patients with CVI at various stages of the disease. The concentrations of CRP and AAT were determined.

Results

The concentration of CRP in patients before the use of Sulodexide, compared to the results in the reference group, was statistically significantly higher. The concentration decreased significantly after the applied treatment. AAT concentration was significantly (p < 0.05) higher in the group of patients compared to the reference group. After treatment with Sulodexide, AAT concentration decreased in all study groups, which was statistically significant compared to the reference group.

Conclusions

Elevated levels of acute phase proteins: CRP and AAT in patients indicate the participation of the inflammatory component in the pathogenesis of CVI. Monitoring levels of acute phase protein, especially AAT, may be useful in tracking the course of the disease, the body's response to treatment, and in making prognosis. Sulodexide, which acts mainly as an anticoagulant and profibrinolytic, also has an anti-inflammatory effect, which may contribute to the inhibition of the development of subsequent stages of CVI.

Could PD-L1 positivity be associated with venous thrombosis in patients with non-small cell lung cancer?

The risk of venous thromboembolism (VTE) is increased in non-small cell lung cancer (NSCLC), and defining at-risk patients is important. Thus, we aimed to assess the association between programmed cell death ligand 1 (PD-L1) expression and VTE [pulmonary embolism (PE), deep venous thrombosis (DVT)] in NSCLC. In this retrospective, observational multicentre study, 369 patients with NSCLC who had PD-L1 immunohistochemistry based on biopsies taken between January 2017 and December 2019, were divided as PD-L1-positive (n = 181) and -negative (n = 188) groups, and low-positive (n = 99) and high-positive (n = 82) PD-L1 groups. Among all population, 12.5% of them developed a VTE during a median follow-up of 474 days. The rates of DVT, PE, and PE + DVT were 5.7%, 6% and 0.8%, respectively. VTE (15.5% vs. 9.5%) and DVT (3.8% vs. 7.4%) were similar between two groups, while PE was significantly higher in PD‑L1-positive group than those in PD-L1-negative group (11.1% vs 1%, p < 0.001). There were no significant differences between low- and high-positive groups in terms of VTE (14.1% vs. 17%), PE (12.1% vs. 9.8%), and DVT (2% vs. 6.1%). In the multivariate analysis, multiple metastases (Hazard ratio [HR] 4.02; 95% confidence interval [Cl] 1.18-13.63; p = 0.07) and PD-L1 positivity was associated with an increased PE risk (HR 8.39; 95% Cl 2.07-34.07; p = 0.003). In conclusion, PD-L1 positivity may be of important role in predicting the increased risk of PE in patients with NSCLC and thereby may be used to define patients likely to benefit from thromboprophylaxis.

Machine learning algorithm as a prognostic tool for venous thromboembolism in allogeneic transplant patients

As a serious complication after allogenic hematopoietic stem cell transplantation (allo-HSCT), venous thromboembolism (VTE) is significantly related to increased nonrelapse mortality. Therefore distinguishing patients at high risk of death who should receive specific therapeutic management is key to improving survival. This study aimed to establish a machine learning-based prognostic model for the identification of post-transplantation VTE patients who have a high risk of death. We retrospectively evaluated 256 consecutive VTE patients who underwent allo-HSCT at our center between 2008 and 2019. These patients were further randomly divided into (1) a derivation (80%) cohort of 205 patients and (2) a test (20%) cohort of 51 patients. The least absolute shrinkage and selection operator (LASSO) approach was used to choose the potential predictors from the primary dataset. Eight machine learning classifiers were used to produce 8 candidate models. A 10-fold cross-validation procedure was used to internally evaluate the models and to select the best-performing model for external assessment using the test cohort. In total, 256 of 7238 patients were diagnosed with VTE after transplantation. Among them, 118 patients (46.1%) had catheter-related venous thrombosis, 107 (41.8%) had isolated deep-vein thrombosis (DVT), 20 (7.8%) had isolated pulmonary embolism (PE), and 11 (4.3%) had concomitant DVT and PE. The 2-year overall survival (OS) rate of patients with VTE was 68.8%. Using LASSO regression, 8 potential features were selected from the 54 candidate variables. The best-performing algorithm based on the 10-fold cross-validation runs was a logistic regression classifier. Therefore a prognostic model named BRIDGE was then established to predict the 2-year OS rate. The areas under the curves of the BRIDGE model were 0.883, 0.871, and 0.858 for the training, validation, and test cohorts, respectively. The Hosmer-Lemeshow goodness-of-fit test showed a high agreement between the predicted and observed outcomes. Decision curve analysis indicated that VTE patients could benefit from the clinical application of the prognostic model. A BRIDGE risk score calculator for predicting the study result is available online (47.94.162.105:8080/bridge/). We established the BRIDGE model to precisely predict the risk for all-cause death in VTE patients after allo-HSCT. Identifying VTE patients who have a high risk of death can help physicians treat these patients in advance, which will improve patient survival.

Low ambient temperature might trigger the symptom onset of pulmonary embolism: A nationwide case-crossover study at hourly level in China

BACKGROUND

Pulmonary embolism (PE) is an important cause of death and its seasonality has long been observed. Very few epidemiological studies have explored the potential role of ambient temperature in PE symptom onset, especially at the hourly level.

METHODS

We conducted a time-stratified case-crossover study among 17,903 PE patients with hourly onset of symptom from 1590 hospitals across China between January 2015 and September 2020. Conditional logistic regression model combined with distributed lag non-linear models were used to explore the associations between hourly ambient temperature and PE symptom onset. The attributable fractions due to non-optimum temperature were calculated.

RESULTS

The exposure-response relationship curve was inverse and almost linear. Lower temperature was significantly associated with higher risk of PE symptom onset when temperature was below 18 °C. This risk occurred immediately at the same hour, attenuated thereafter, and became nonsignificant at approximately 72 h after exposure. Compared with the referent temperature (P₉₉, 34.1 °C), the odds ratio of PE symptom onset associated with extremely low temperature (P₁, -16.1 °C) over lag 0-72 h was 1.63 (95%CI: 1.23, 2.16). Low temperature may account for 16.19 % of the symptom onset nationally with higher proportion in the south of China. The effects were stronger in older adults, males, and cold seasons.

CONCLUSIONS

We provided the first-hand robust evidence that transient exposure (at the hourly level) to low temperature might trigger the symptom onset of PE and constitute a considerable burden for PE patients. Targeted protections and health education are needed for susceptible populations.

Genome- and transcriptome-wide association studies show that pulmonary embolism is associated with bone-forming proteins

BACKGROUND

Pulmonary embolism (PE) is a leading cause of death in stroke patients and a severe health burden worldwide. There is a pressing need to understand the mechanisms by which it occurs and to identify at-risk patients efficiently and accurately.

OBJECTIVES

The aim of this paper was to analyze the genetic correlation between PE and human plasma proteins through genome-wide association study (GWAS) with transcriptome-wide association study (TWAS), in combination with mRNA expression profiling at three levels: DNA, RNA, and protein.

METHODS

First, based on data from GWAS in European populations, we performed a linkage disequilibrium score regression (LDSC) analysis of plasma proteins and PE in 3,283 individuals and additionally analyzed the genetic association between PE and fracture. Then, we performed a TWAS on PE GWAS data using skeletal muscle and blood for gene expression references. Finally, we validated the genetic correlation between PE and human plasma proteins by co-matching the genes encoding the identified proteins and those identified using TWAS with the differentially expressed genes obtained from mRNA expression profiling of PE (Figure1).

RESULTS

We identified five plasma proteins associated with PE, including hydroxycarboxylic acid receptor 2, defensin 118, and bone morphogenetic protein (BMP) 7, as well as a relationship between PE and fracture. Comparison of genes encoding these proteins with genes obtained from TWAS and then with differentially expressed genes obtained from PE mRNA expression profiling revealed that PE was highly correlated with the BMP family of genes.

Assessment and Mitigation of Bleeding Risk in Atrial Fibrillation and Venous Thromboembolism: Executive Summary of a European and Asia-Pacific Expert Consensus Paper

While there is a clear clinical benefit of oral anticoagulation in patients with atrial fibrillation (AF) and venous thromboembolism (VTE) in reducing the risks of thromboembolism, major bleeding events (especially intracranial bleeds) may still occur and be devastating. The decision for initiating and continuing anticoagulation is often based on a careful assessment of both thromboembolism and bleeding risk. The more common and validated bleeding risk factors have been used to formulate bleeding risk stratification scores, but thromboembolism and bleeding risk factors often overlap. Also, many factors that increase bleeding risk are transient and modifiable, such as variable international normalized ratio values, surgical procedures, vascular procedures, or drug-drug and food-drug interactions. Bleeding risk is also not a static "one-off" assessment based on baseline factors but is dynamic, being influenced by aging, incident comorbidities, and drug therapies. In this executive summary of a European and Asia-Pacific Expert Consensus Paper, we comprehensively review the published evidence and propose a consensus on bleeding risk assessments in patients with AF and VTE, with a view to summarizing "best practice" when approaching antithrombotic therapy in these patients. We address the epidemiology and size of the problem of bleeding risk in AF and VTE, and review established bleeding risk factors and summarize definitions of bleeding. Patient values and preferences, balancing the risk of bleeding against thromboembolism, are reviewed, and the prognostic implications of bleeding are discussed. We propose consensus statements that may help to define evidence gaps and assist in everyday clinical practice.

Assessment and mitigation of bleeding risk in atrial fibrillation and venous thromboembolism: A Position Paper from the ESC Working Group on Thrombosis, in collaboration with the European Heart Rhythm Association, the Association for Acute CardioVascular Care and the Asia-Pacific Heart Rhythm Society

Whilst there is a clear clinical benefit of oral anticoagulation (OAC) in patients with atrial fibrillation (AF) and venous thromboembolism (VTE) in reducing the risks of thromboembolism, major bleeding events (especially intracranial bleeds) may still occur and be devastating. The decision to initiate and continue anticoagulation is often based on a careful assessment of both the thromboembolism and bleeding risk. The more common and validated bleeding risk factors have been used to formulate bleeding risk stratification scores, but thromboembolism and bleeding risk factors often overlap. Also, many factors that increase bleeding risk are transient and modifiable, such as variable international normalized ratio values, surgical procedures, vascular procedures, or drug-drug and food-drug interactions. Bleeding risk is also not a static 'one off' assessment based on baseline factors but is dynamic, being influenced by ageing, incident comorbidities, and drug therapies. In this Consensus Document, we comprehensively review the published evidence and propose a consensus on bleeding risk assessments in patients with AF and VTE, with the view to summarizing 'best practice' when approaching antithrombotic therapy in these patients. We address the epidemiology and size of the problem of bleeding risk in AF and VTE, review established bleeding risk factors, and summarize definitions of bleeding. Patient values and preferences, balancing the risk of bleeding against thromboembolism are reviewed, and the prognostic implications of bleeding are discussed. We propose consensus statements that may help to define evidence gaps and assist in everyday clinical practice.

Liquid Biopsy and Potential Liquid Biopsy-Based Biomarkers in Philadelphia-Negative Classical Myeloproliferative Neoplasms: A Systematic Review

Myeloproliferative neoplasms (MPNs) are rare, clonal disorders of the hematopoietic stem cell in which an uncontrolled proliferation of terminally differentiated myeloid cells is noted. Polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF) are included in the category of Philadelphia-negative, so-called classical MPNs. The potential applications of liquid biopsy and liquid biopsy-based biomarkers have not been explored in MPNs until now. Thus, a systematic search was computed in PubMed/MEDLINE, Web of Science and The Cochrane Library and, in total, 198 potentially relevant papers were detected. Following the removal of duplicates (n = 85), 113 records were screened. After the exclusion of irrelevant manuscripts based on the screening of their titles and abstracts (n = 81), we examined the full texts of 33 manuscripts. Finally, after we applied the exclusion and inclusion criteria, 27 original articles were included in this review. Overall, the data analyzed in this review point out that liquid biopsy and liquid biopsy-based biomarkers (cell-free DNA, extracellular vesicles, microparticles, circulating endothelial cells) could be used in MPNs for diagnostic and prognostic purposes. Future research is needed to clarify whether this technique can be employed to differentiate between MPN subtypes and secondary causes of erythrocytosis, thrombocytosis and myelofibrosis, as well as to predict the development of thrombosis.