Deep vein thrombosis and pulmonary embolism

Prognostic role of elevated lactate in acute pulmonary embolism: A systematic review and meta-analysis

BACKGROUND

Previous studies have shown elevated lactate was a good predictor for the prognosis of pulmonary embolism (PE). However, due to low number of patients and different expression of blood lactate in separate study, these results are inconsistent. Therefore, the aim of this meta-analysis is to evaluate the relationship between increased lactate levels and adverse outcome in acute PE.

METHOD

The literatures search was conducted in PubMed, Web of Science, and EMBASE until May 29, 2021.

RESULTS

Finally, 6 studies with 1706 patients were included in our meta-analysis. High lactate levels were markedly associated with overall mortality both in unselected PE patients (OR 5.13, 95% CI: 3.36-7.86, p < .00,001) and normotensive PE patients (OR 4.54, 95% CI: 2.64-7.80, p < .00,001), and PE-related short-term mortality in patients with elevated lactate was significantly higher than that in patients with normal levels (OR 9.05, 95% CI :4.08-20.10, p < .00,001). The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of lactate for predicting overall mortality in patients with acute PE were 0.67 (95% CI: 0.43-0.85), 0.73 (95% CI: 0.60-0.83), 2.5 (95% CI: 2.0-3.1), and 0.45 (95% CI: 0.26-0.78), respectively. The area under SROC curve (AUC) was 0.76 (95% CI: 0.73-0.80).

CONCLUSION

The result of our meta-analysis indicate that elevated blood lactate is a good predictor for overall mortality and short-term mortality in patients with acute PE, and can be routinely measured in risk stratification, but its prognostic role in patients with different risk classes still need to be verified.

First-Time Submassive Pulmonary Embolism Likely Caused by Testosterone-Enhancing Supplement

Pulmonary embolism (PE) is a potentially fatal occurrence with a broad spectrum of risk factors. A 75-year-old male presented to the emergency room with five days of shortness of breath, back pain, and hemoptysis. A CT angiogram demonstrated bilateral pulmonary emboli with a larger thrombus on the right, as well as signs of right heart strain. The patient was started on IV heparin and ultimately underwent a successful embolectomy. Evaluation to determine the underlying etiology of this patient's first-time PE was performed to further stratify his risk of recurrence and the length of anticoagulation required. The provoking factor for his PE was initially unclear as he lacked any risk factors such as recent surgeries, periods of immobility, or previous diagnosis of malignancy. The patient was noted to be on an erectile dysfunction supplement called “Eroxin,” and he had been taking it for the past six months. Eroxin contains an ingredient called fenugreek, which is believed to enhance testosterone levels by inhibiting aromatase and 5-alpha-reductase activity. Fenugreek has previously been associated with the formation of PEs, and likely contributed to the PE in this patient. This is likely due to testosterone-induced polycythemia and increased platelet aggregation. This case highlights the concern around supplements as their ingredients are poorly regulated and occasionally found to be tainted with unlisted ingredients. This also highlights the importance of gathering a complete supplement history from patients as their use can lead to serious illness. Lastly, it encourages considering testosterone use as a potential thrombogenic risk factor.

Association Between Different DVT Prevention Methods and Outcomes of Septic Shock Caused by Intestinal Perforation in China: A Cross-Sectional Study

Introduction

Septic shock, largely caused by intestinal perforation, is the most common critical illness in intensive care unit (ICU). As an important quality control strategy in ICU, deep vein thrombosis (DVT) prevention is routinely used in the treatment of septic shock. Nevertheless, the effects of DVT prevention on septic shock are not fully revealed. This study was thus designed to investigate the effects of DVT prevention on septic shock caused by intestinal perforation in China.

Methods

A total of 463 hospitals were enrolled in a survey, led by the China National Critical Care Quality Control Center (China NCCQC) from January 1, 2018 to December 31, 2018. The association between DVT prevention, including pharmacological prophylaxis and mechanical prophylaxis, and outcomes, such as prognosis, complications, hospital stays, and hospitalization costs, was determined in the present study.

Main Results

Notably, the increased rates of DVT prevention were not associated with the onset of complications in patients with septic shock caused by intestinal perforation (p > 0.05). In addition, even though increased DVT prevention did not affect hospital stays, it significantly decreased the discharge rates without doctor's order in patients with septic shock caused by intestinal perforation (p < 0.05). Nevertheless, it should be noted that the rates of pharmacological prophylaxis but not mechanical prophylaxis were significantly associated with the costs of septic shock caused by intestinal perforation (p < 0.05). Although increased total rates of DVT prevention and the rates of mechanical prophylaxis did not reduce the mortality in patients with septic shock caused by intestinal perforation, the higher frequent intervention using pharmacological prophylaxis indicated the lower mortality of these patients (p < 0.05).

Conclusions

DVT prevention by any means is a safe therapeutic strategy for treating septic shock caused by intestinal perforation, and pharmacological prophylaxis reduced the mortality of patients with septic shock caused by intestinal perforation.

Large-scale genetic correlation scanning and causal association between deep vein thrombosis and human blood metabolites

Deep vein thrombosis (DVT) refers to the abnormal coagulation of blood in a deep vein. Recently, some studies have found that metabolites are related to the occurrence of DVT and may serve as new markers for the diagnosis of DVT. In this study, we used the GWAS summary dataset of blood metabolites and DVT to perform a large-scale genetic correlation scan of DVT and blood metabolites to explore the correlation between blood metabolites and DVT. We used GWAS summary data of DVT from the UK Biobank (UK Biobank fields: 20002) and GWAS summary data of blood metabolites from a previously published study (including 529 metabolites in plasma or serum from 7824 adults from two European population studies) for genetic correlation analysis. Then, we conducted a causal study between the screened blood metabolites and DVT by Mendelian randomization (MR) analysis. In the first stage, genetic correlation analysis identified 9 blood metabolites that demonstrated a suggestive association with DVT. These metabolites included Valine (correlation coefficient = 0.2440, P value = 0.0430), Carnitine (correlation coefficient = 0.1574, P value = 0.0146), Hydroxytryptophan (correlation coefficient = 0.2376, P value = 0.0360), and 1-stearoylglycerophosphoethanolamine (correlation coefficient = - 0.3850, P value = 0.0258). Then, based on the IVW MR model, we analysed the causal relationship between the screened blood metabolites and DVT and found that there was a suggestive causal relationship between Hydroxytryptophan (exposure) and DVT (outcome) (β = - 0.0378, se = 0.0163, P = 0.0204). Our study identified a set of candidate blood metabolites that showed a suggestive association with DVT. We hope that our findings will provide new insights into the pathogenesis and diagnosis of DVT in the future.

Survival Prediction in Patients with Hypertensive Chronic Kidney Disease in Intensive Care Unit: A Retrospective Analysis Based on the MIMIC-III Database

Objective

Disease prediction is crucial to treatment success. The aim of this study was to accurately and explicably predict, based on the first laboratory measurements, medications, and demographic information, the risk of death in patients with hypertensive chronic kidney disease within 1 and 3 years after admission to the Intensive Care Unit (ICU).

Methods

Patients with hypertensive chronic kidney disease who had been registered in the Medical Information Mart for Intensive Care (MIMIC-III) database of critical care medicine were set as the subject of study, which was randomly divided into a training set and a validation set in a ratio of 7 : 3. Univariate Cox regression analysis and stepwise Cox regression analysis were applied in the training set to identify the predictive factors of prognosis of patients with hypertensive chronic kidney disease in ICU, and the predictive nomogram based on Cox regression model was constructed. We internally validated the model in the training set and externally validated that in the validation model. The efficacy was assessed primarily through area under the receiver operating characteristic (ROC) curve, clinical decision curves, and calibration curves.

Results

A total of 1762 patients with hypertensive chronic kidney disease were finally included. During the 3-year follow-up, 667 patients (37.85%) died, with a median follow-up time of 220 days (1-1090). The data set were randomly divided into a training set (n = 1231) and a validation set (n = 531). It was identified in the training set that insurance, albumin, alkaline phosphatase, the mean corpuscular hemoglobin concentration, mean corpuscular volume, history of coronary angiogram, hyperlipemia, medication of digoxin, acute renal failure, and history of renal surgery were the most relevant features. Taking 1 year and 3 years as the cut-off points, the AUC of participants were 0.736 and 0.744, respectively, in the internal validation and were 0.775 and 0.769, respectively, in the external validation, suggesting that the model is of favorable predictive efficacy.

Conclusion

We trained and validated a model using data from a large multicenter cohort, which has considerable predictive performance on an individual scale and could be used to improve treatment strategies.

Comparison of deep vein thrombosis risks in acute respiratory distress syndrome caused by COVID-19 and bacterial pneumonia: a retrospective cohort study

BACKGROUND

High incidence of deep vein thrombosis (DVT) has been observed in patients with acute respiratory distress syndrome (ARDS) caused by COVID-19 and those by bacterial pneumonia. However, the differences of incidence and risk factors of DVT in these two groups of ARDS had not been reported before.

STUDY DESIGN AND METHODS

We performed a retrospective cohort study to investigate the difference of DVT in incidence and risk factors between the two independent cohorts of ARDS and eventually enrolled 240 patients, 105 of whom with ARDS caused by COVID-19 and 135 caused by bacterial pneumonia. Lower extremity venous compression ultrasound scanning was performed whenever possible regardless of clinical symptoms in the lower limbs. Clinical characteristics, including demographic information, clinical history, vital signs, laboratory findings, treatments, complications, and outcomes, were analyzed for patients with and without DVT in these two cohorts.

RESULTS

The 28-days incidence of DVT was higher in patients with COVID-19 than in those with bacterial pneumonia (57.1% vs 41.5%, P = 0.016). Taking death as a competitive risk, the Fine-Gray test showed no significant difference in the 28-day cumulative incidence of DVT between these two groups (P = 0.220). Fine-Gray competing risk analysis also showed an association between increased CK (creatine kinase isoenzyme)-MB levels (P = 0.003), decreased PaO2 (partial pressure of arterial oxygen)/FiO2 (fraction of inspired oxygen) ratios (P = 0.081), increased D-dimer levels (P = 0.064) and increased incidence of DVT in COVID-19 cohort, and an association between invasive mechanical ventilation (IMV; P = 0.001) and higher incidence of DVT and an association between VTE prophylaxis (P = 0.007) and lower incidence of DVT in bacterial pneumonia cohort. The sensitivity and specificity of the corresponding receiver operating characteristic curve originating from the combination of CK-MB levels, PaO2/FiO2 ratios, and D-dimer levels ≥0.5 μg/mL were higher than that of the DVT Wells score (P = 0.020) and were not inferior to that of the Padua prediction score (P = 0.363) for assessing the risk of DVT in COVID-19 cohort.

CONCLUSIONS

The incidence of DVT in patients with ARDS caused by COVID-19 is higher than those caused by bacterial pneumonia. Furthermore, the risk factors for DVT are completely different between these two ARDS cohorts. It is suggested that COVID-19 is probably an additional risk factor for DVT in ARDS patients.

Significant role of long non-coding RNA MALAT1 in deep vein thrombosis via the regulation of vascular endothelial cell physiology through the microRNA-383-5p/BCL2L11 axis

Deep vein thrombosis (DVT) is a vascular disease. The long non-coding RNA (lncRNA), metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), is positively expressed in DVT tissues, and regulates the biological behavior of endothelial progenitor cells. Here, we explored whether MALAT1 affected the physiology of human vascular endothelial cells (HUVECs) and analyzed its underlying mechanism. To overexpress/silence the expression of MALAT1 in HUVECs, MALAT1-plasmid/MALAT1-small interfering RNA (siRNA) was used. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and flow cytometry analyses were performed to observe the cell viability and apoptosis. Reverse transcription-quantitative polymerase chain reaction and western blotting were used to determine the apoptosis-related protein and gene expression levels. We used Starbase software to predict the associations among MALAT1, microRNA (miR)-383-5p, and BCL2-like 11 (BCL2L11). Luciferase reporter assay was used to validate their relationship. Compared to the control vector group, MALAT1-plasmid suppressed the viability and induced apoptosis of HUVECs, while improving Bcl-2-associated X protein (Bax) expression and decreasing Bcl-2 expression. There was an interaction between MALAT1 and miR-383-5p. Compared to the control siRNA group, MALAT1-siRNA increased the cell viability, reduced cell apoptosis, upregulated Bcl-2 expression, and suppressed Bax expression. These changes were reversed by the miR-383-5p inhibitor. Additionally, we verified that BCL2L11 is a target of miR-383-5p. miR-383-5p improved the cell proliferation, while decreasing cell apoptosis in HUVECs by targeting BCL2L11. Therefore, the lncRNA-MALAT1/miR-383-5p/BCL2L11 axis may be effective for DVT treatment.

KLF11 Protects against Venous Thrombosis via Suppressing Tissue Factor Expression

Krüppel-like factors (KLFs) play essential roles in multiple biological functions, including maintaining vascular homeostasis. KLF11, a causative gene for maturity-onset diabetes of the young type 7, inhibits endothelial activation and protects against stroke. However, the role of KLF11 in venous thrombosis remains to be explored. Utilizing stasis-induced murine deep vein thrombosis (DVT) model and cultured endothelial cells (ECs), we identified an increase of KLF11 expression under prothrombotic conditions both in vivo and in vitro. The expression change of thrombosis-related genes was determined by utilizing gain- and loss-of-function approaches to alter KLF11 expression in ECs. Among these genes, KLF11 significantly downregulated tumor necrosis factor-α (TNF-α)-induced tissue factor (TF) gene transcription. Using reporter gene assay, chromatin immunoprecipitation assay, and co-immunoprecipitation, we revealed that KLF11 could reduce TNF-α-induced binding of early growth response 1 (EGR1) to TF gene promoter in ECs. In addition, we demonstrated that conventional Klf11 knockout mice were more susceptible to developing stasis-induced DVT. These results suggest that under prothrombotic conditions, KLF11 downregulates TF gene transcription via inhibition of EGR1 in ECs. In conclusion, KLF11 protects against venous thrombosis, constituting a potential molecular target for treating thrombosis.

Epidemiological characteristics, clinical relevance, and risk factors of thromboembolic complications among patients with COVID-19 pneumonia at A teaching hospital: Retrospective observational study

Background

Thromboembolism is the third most common cardiovascular disorders and substantial worldwide health burden, with 1-2 instances per 1000 persons each year. This study aimed to describe the epidemiological characteristics, clinical relevance, risk factor and outcome of thromboembolic complications among COVID-19 infected patients.

Method

This is a retrospective, single-center, observational study using a hospital information system (HIS). The study included 46-patients with a confirmed diagnosis of pneumonia by SARS-CoV-2 admitted to a tertiary hospital.

Results

The incidence of cardiovascular thromboembolic events among COVID-19 infected patients was 41.3% (n = 19). Cerebrovascular accident was the most common thromboembolic events among COVID-19 infected patients about 15.2%, flowed by pulmonary embolism (13%), acute myocardial infract (8.7%), and deep venous thrombosis (4.4%). In generally, 63% (n = 29) were males, while 37% (n = 17) were females. The majority of those who suffered thromboembolic events were over 65 years old (p < 0.000**).Patients with thromboembolic event were also more likely to have IHD (13.0% vs 0%, p = 0.003), diabetes (24% vs 13.0%, p = 0.025) and CL (10.9% vs 2.2%, p = 0.03) as precipitating factors when compared those without thromboembolic events.According to the outcome, 19 examinees had thrombotic events: 11 (24%) patients had admitted to non ICU inpatient ward, 2 (43%) had admitted to ICU and remaining 6 (13%) patients had dead. There was significant statistical difference in the proportion of examinees with thrombotic and non-thrombotic events in relation to outcome (p = 0.000).

Conclusion

The incidence of thromboembolic complications among COVID19 infected patients were associated with elder (>65years), IHD, diabetes and CLD.

Risk factors of pulmonary embolism in the elderly patients: a retrospective study

AIM

We aimed to summarize the clinical feature and risk factors of patients suffering from pulmonary embolism (PE) in the elderly patients, and explore the change in D-dimer after anti-coagulant therapy.

METHODS

A total of 426 patients with PE admitted from August 2012 to January 2019 in the Cangzhou Central Hospital were analyzed in this retrospective study. A comparison of clinical features and risk factors was conducted between the elderly group and non-elderly groups. Blood levels of D-dimer, C-reactive protein (CRP), tumor necrosis factor-α and interferon-γ were measured before and 3 days after anti-coagulant therapy in two groups.

RESULTS

The most important risk factor for the elderly patients was stroke, while for non-elderly patients was deep vein thrombosis (DVT). After anti-coagulant therapy, the decreasing level of D-dimer and CRP showed statistically significant differences between the two groups. Between the elderly and non-elderly groups, the main clinical manifestations were similar. The risk factors of elderly patients were chronic obstructive pulmonary disease, malignant tumor, DVT and stroke. After anti-coagulant therapy, the content of D-dimer was lower than 3 days ago.

CONCLUSION

Blood levels of D-dimer and CRP may be potent screening markers for PE especially among elderly patients.

Risk of venous thromboembolism in children and adolescents with inflammatory bowel disease: A systematic review and meta-analysis

BACKGROUND

A two- to three-fold increased risk of venous thrombotic events (VTE) has been demonstrated in patients with inflammatory bowel disease (IBD) compared to the general population, but less is known about the risk of VTE in child- and pediatric-onset IBD. In recent years, several studies have reported the rising incidence rate of VTE in juvenile patients with IBD, and the related risk factors have been explored.

AIM

To evaluate the risk of VTE in children and adolescents with IBD.

METHODS

Articles published up to April 2021 were retrieved from PubMed, Embase, Cochrane Library, Web of Science, SinoMed, CNKI, and WANFANG. Data from observational studies and clinical work were extracted. The outcome was the occurrence of VTE according to the type of IBD. The available odds ratio (OR) and the corresponding 95% confidence interval (CI) were extracted to compare the outcomes. Effect size (P), odds ratio (OR), and 95%CI were used to assess the association between VTE risk and IBD disease. Subgroup analyses stratified by subtypes of VTE and IBD were performed.

RESULTS

Twelve studies (7450272 IBD patients) were included in the meta-analysis. Child and adolescent IBD patients showed increased VTE risk (P = 0.02, 95%CI: 0.01-0.03). Subgroup analyses stratified by IBD (ulcerative colitis (UC): P = 0.05, 95%CI: 0.03-0.06; Crohn's disease (CD): P = 0.02, 95%CI: 0.00-0.04) and VTE subtypes (portal vein thrombosis: P = 0.04, 95%CI: 0.02-0.06; deep vein thrombosis: P = 0.03, 95%CI: 0.01-0.05; central venous catheter-related thrombosis: P = 0.23, 95%CI: 0.00-0.46; thromboembolic events: P = 0.02, 95%CI: 0.01-0.03) revealed a significant correlation between VTE risk and IBD. Patients with IBD were more susceptible to VTE risk than those without IBD (OR = 2.99, 95%CI: 1.45-6.18). The funnel plot was asymmetric, suggesting the presence of significant publication bias. Pediatric and adolescent IBD patients have an increased VTE risk. UC and CD patients exhibited a high risk of VTE. The risk of VTE subtypes was increased in IBD patients.

CONCLUSION

The current meta-analysis showed that the incidence and risk of VTE are significantly increased in pediatric and adolescent IBD patients. Thus, IBD might be a risk factor for VTE in children and young adults. High-quality prospective cohort studies are necessary to confirm these findings.

Egg and cholesterol intake, apolipoprotein E4 phenotype and risk of venous thromboembolism: findings from a prospective cohort study

The impact of egg consumption, a major source of dietary cholesterol, with the risk of atherosclerotic cardiovascular diseases (ASCVDs) is controversial. Venous thromboembolism (VTE) is a CVD which shares common risk factors and mechanistic pathways with ASCVD. However, there is no data on the relationship between egg or cholesterol intake and VTE risk. Therefore, we evaluated the prospective associations of egg and cholesterol intakes with VTE risk and whether the apolipoprotein E4 (apoE4) phenotype, which influences cholesterol metabolism, could modify the associations. Data involving 1,852 men aged 42-61 years at baseline without a history of VTE or coronary heart disease in the population-based Kuopio Ischaemic Heart Disease Risk Factor Study were analysed. Dietary intakes were assessed with 4-day food records. Incident VTE events were identified by record linkage to hospital discharge registries. Hazard ratios (95% confidence intervals [CIs]) for incident VTE were estimated using Cox regression. During a median follow-up of 28.8 years, 132 VTE events occurred. Comparing the top (>38 g/d) versus bottom (<20 g/d) tertiles of egg consumption, the HR (95% CI) for VTE was 0.99 (0.64-1.53) in analysis adjusted for several established risk factors and other dietary factors. There was also no evidence of an association between cholesterol intake and VTE risk. Imputed results were consistent with the observed results. The apoE4 phenotype did not modify the associations. In middle-aged and older Finnish men, egg or cholesterol intakes were not associated with future VTE risk. Other large-scale prospective studies are needed to confirm or refute these findings.

Early warning prevention and control strategies to reduce perioperative venous thromboembolism in patients with gastrointestinal cancer

BACKGROUND

Venous thromboembolism (VTE) is a major cause of unexpected and perioperative in-hospital deaths. It is characterized by high morbidity, high mortality, high misdiagnosis rate, and high missed diagnosis rates. VTE is a common postoperative complication in cancer patients. VTE is preventable, and early identification of risk factors leading to VTE and appropriate early preventive actions can reduce its occurrence and mortality. Presently, there is no uniform standard for the prevention and control of VTE in clinical practice, and hospitals in China lack mature and effective protocols for the assessment, prevention, and treatment of VTE.

AIM

To explore whether an early warning program could influence the occurrence of deep vein thrombosis (DVT) postoperatively.

METHODS

This is a comparative retrospective cohort study, which enrolled patients who underwent laparotomic or laparoscopic gastrointestinal tumor resection for gastrointestinal cancer between January 2016 and December 2019. Patients were divided into a control group and an early warning group depending on whether or not the early warning program was implemented. A venous thromboembolism prevention and control team was established. The outcomes included the occurrence of DVT, the correct rate of VTE assessment, the coagulation indicators, and the mastery of VTE knowledge by the nurses.

RESULTS

A total of 264 patients were included in this study, with 128 patients in the control group and 136 patients in the early warning group. The occurrence rate of DVT in the early warning group was 6.6% (9/136), compared with 14.1% (18/128) in the control group (P < 0.05). The correct rates of VTE risk assessment by the nurses and standard implementation rate of VTE preventive measures were 86.8% vs 65.6% and 80.2% vs 57.8% in early warning and control groups, respectively (all P < 0.001). The independent factors associated with postoperative DVT occurrence were age (OR = 1.083, 95%CI: 1.070-3.265, P = 0.032), Hyperlipidemia (OR = 1.127, 95%CI: 1.139-2.564, P = 0.042), preoperative high VTE risk (OR = 2.131, 95%CI: 1.085-5.178, P = 0.001), time of operation (OR = 2.268, 95%CI: 2.005-5.546, P = 0.026) and not adoption of early warning prevention (OR = 3.747, 95%CI: 1.523-6.956, P = 0.017).

CONCLUSION

The early warning strategy was independently associated with the decreasing occurrence of VTE, and it might be suitable for protection from VTE in patients undergoing gastrointestinal cancer surgery.

Trends and risk factors for omission of early thromboprophylaxis in Australian and New Zealand ICUs between 2009 and 2020

Purpose

Venous thromboembolism (VTE) prophylaxis is effective in reducing VTE events; however, it is underutilized in critically ill patients. We examined trends and risk factors for omission of early thromboprophylaxis within the first 24 h after admission in Australian and New Zealand intensive care units (ICUs) between 2009 and 2020.

Methods

Retrospective analysis of data from the Australian New Zealand Intensive Care Society Adult Patient Database. Data were obtained for 1,465,020 adult admissions between 2009 and 2020. Mixed effects logistic regression modeling (accounting for the random effects of the contributing ICUs) was used to identify factors associated with omission of early thromboprophylaxis.

Results

A total of 107,486 (7.3%) ICU patients did not receive any form of thromboprophylaxis within the first 24 h after ICU admission without obvious reasons. Omission of early thromboprophylaxis declined from 13.7% in 2009 to 4% in 2020 (by 70.8%) (P < 0.001). Younger patients were more like to miss out on VTE prophylaxis (odds ratios (OR)_{per 10-year increase} 0.94, 95% CI 0.95–0.99). A documented process for monitoring VTE prophylaxis (ORs 0.90, 95% CI 0.87–0.93) and having a medical lead, dedicated for coordinating ICU quality (OR_{per 0.1 increase in full-time equivalent} 0.97, 95% CI 0.93–0.99), are associated with less omission of VTE prophylaxis.

Conclusion

Omission of thromboprophylaxis within the first 24 h after ICU admission has declined steadily over the past decade. Documented process for monitoring VTE prophylaxis and having a medical lead for coordinating quality of ICU care could be potential targets for sustaining the improvement in VTE prophylaxis use.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-022-06672-7.

A Fibrin Site-Specific Nanoprobe for Imaging Fibrin-Rich Thrombi and Preventing Thrombus Formation in Venous Vessels

Venous thromboembolism (VTE) is a prevalent public health issue worldwide. Before treatment, spatiotemporally accurate thrombus detection is essential. However, with the currently available imaging technologies, this is challenging. Herein, the development of a novel fibrin-specific nanoprobe (NP) based on the conjugation of poly(lactic-co-glycolic acid) with the pentapeptide Cys-Arg-Glu-Lys-Ala (CREKA) for selective and semiquantitative imaging in vivo is presented. By integrating Fe₃ O₄ and NIR fluorochrome (IR780), the NP can function as a highly sensitive sensor for the direct analysis of thrombi in vivo. The fibrin-specific NP distinguishes fibrin-rich thrombi from collagen-rich or erythrocyte-rich thrombi, which can be beneficial for future individually tailored therapeutic strategy. Furthermore, loading NPs with the ketotifen fumarate results in mast cell degranulation inhibition, and hence, NPs can prevent thrombosis without the risk of excessive bleeding. Thus, the use of fibrin-specific NPs may serve as a safe alternative approach for the detection and prevention of VTEs in susceptible populations in the future.

Endovascular Intervention for May-Thurner Syndrome in a Pregnant Patient with a Patent Foramen Ovale and Paradoxical Embolism

May-Thurner syndrome (MTS) is a known structural risk factor for deep vein thrombosis (DVT) and embolism. In patients with a patent foramen ovale (PFO), emboli originating from the deep veins are able to paradoxically reach the systemic circulation via the PFO, consequently resulting in transient ischemic attacks (TIA) or stroke.We report the case of a 31-year-old pregnant woman, with a recent history of TIA, who presented with chronic bilateral numbness, pain, and swelling in the lower extremities. On imaging, she was found to have a PFO and MTS. Her pregnancy was subsequently terminated. This decision was made independently by the patient. Her care team did not advise her to terminate her pregnancy as there was no specific medical reason to do so. However, the patient was in significant physical pain and distress and ultimately was not comfortable continuing with the pregnancy. This highlights the complex, multifactorial decision-making process that pregnant patients with comorbid health conditions undertake. The patient then underwent transcatheter PFO closure and stents were placed bilaterally in the left and right common iliac veins. Following the stent procedure, lower extremity symptoms swiftly resolved, allowing the patient to significantly improve her ability to ambulate. There have been no signs of TIA since her procedures, and her venous symptoms have been stable.In patients with TIA or stroke from a paradoxical embolism, MTS should be considered as a potential etiology. Endovascular intervention to treat the underlying MTS should also be considered to decrease the risk of recurrent DVT and embolism.

Tenecteplase in Pulmonary Embolism Patients: A Meta-Analysis and Systematic Review

Objective

To assess the efficacy and safety of tenecteplase in patients with pulmonary embolism (PE).

Methods

We completed the literature search on May 31, 2021 using PubMed, EMBASE and the Web of Science. Analyses were conducted according to PE risk stratification, study design and duration of follow-up. The pooled risk ratios (RRs) and its 95% confident intervals (CIs) for death and major bleeding were calculated using a random-effect model.

Results

A total of six studies, with four randomized controlled trials (RCTs) and two cohort studies, were included in this study out of the 160 studies retrieved. For patients with high-risk PE, tenecteplase increased 30-day survival rate (16% vs 6%; P = 0.005) and did not increase the incidence of bleeding (6% vs 5%; P = 0.73). For patients with intermediate-risk PE, four RCTs suggested that tenecteplase reduced right ventricular insufficiency at 24h early in the onset and the incidence of hemodynamic failure without affecting mortality in a short/long-term [<30 days RR = 0.83, 95% CI (0.47, 1.46);≥30 days RR = 1.04, 95% CI (0.88, 1.22)]. However, tenecteplase was associated with high bleeding risk [<30 days RR = 1.79, 95% CI (1.61, 2.00); ≥30 days RR = 1.28, 95% CI (0.62, 2.64)].

Conclusions

Tenecteplase may represent a promising candidate for patients with high risk PE. However, tenecteplase is not recommended for patients with intermediate-risk PE because of high bleeding risk. More large-scale studies focused on tenecteplase are still needed for PE patients.

Association of Metformin Use With Risk of Venous Thromboembolism in Adults With Type 2 Diabetes: A General-Population-Based Cohort Study

Metformin is hypothesized to protect against the risk of venous thromboembolism (VTE); however, there is a paucity of data supporting this hypothesis. Among individuals aged 40-90 years with a diagnosis of type 2 diabetes in the Health Improvement Network database (2000-2019), we compared the risks of incident VTE, pulmonary embolism, and deep vein thrombosis among metformin initiators with those among sulfonylurea initiators. Individuals were followed from their first prescription refill to an incident VTE, drug discontinuation, switching or augmenting, plan disenrollment, or the end of the study, whichever occurred first. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using the Cox model, adjusting for confounders using inverse probability of treatment weighting. Among 117,472 initiators of metformin and 13,835 initiators of sulfonylureas, 555 (1.3/1,000 person-years) and 75 (2.1/1,000 person-years) VTE cases occurred in each group, respectively. The multivariable-adjusted HR was 0.65 (95% CI: 0.51, 0.84). The corresponding risks for pulmonary embolism (adjusted HR = 0.71, 95% CI: 0.50, 1.01) and deep vein thrombosis (adjusted HR = 0.64, 95% CI: 0.48, 0.87) were also lower in metformin initiators than in sulfonylurea initiators. Our study provided empirical evidence to support a lower risk of VTE after initiation of metformin as compared with sulfonylureas among patients with type 2 diabetes.

Evaluation of the modified Wells score in predicting venous thromboembolic disease in patients with tuberculosis or HIV in a South African setting

Background

There is paucity of data on the modified Wells score (MWS) utility on patients with venous thromboembolism (VTE) in a South African setting where there is a high burden of HIV and tuberculosis (TB). This study analyses the performance of this score in HIV/TB-infected patients compared with non-infected patients.

Objectives

To assess the performance of the MWS as an additional risk factor for VTE in hospitalised patients with a high burden of HIV/TB infections.

Method

This study was a retrospective cross-sectional cohort analysis of the utility of the MWS in 156 HIV/TB-infected and non-infected adult patients diagnosed with VTE on compression ultrasonography (CUS) or computed tomography pulmonary angiography (CTPA) in a medical inpatient setting over six months. Patients with HIV and/or TB were assessed as having an additional risk factor (1 point for each), and this was compared with the MWS. A McNeymar’s paired sample chi-squared test was used to compare the sensitivity of this score against the MWS.

Results

Of the 156 patients with VTE who were enrolled, HIV was the commonest risk factor (42.31%) with TB accounting for 10.90% of cases. When the MWS adjusted for HIV/TB was used, the sensitivity increased from 25% to 100% for the HIV–/TB+ category, it increased from 77.36% to 98.11% in the HIV+/TB– category and it increased from 84.62% to 92.95% in the HIV+/TB+ category. These differences were statistically significant at P < 0.05 in all categories.

Conclusion

The MWS performs better when the infectivity of HIV/TB is included as an additional risk factor in the score.

Nanocarrier-Based Management of Venous and Arterial Thrombosis

Cardiovascular diseases represent the leading cause of mortality worldwide, with recent epidemiological studies revealing an increasing trend of prevalence and incidence globally. Among cardiovascular disorders, both arterial and venous thrombosis and particularly their acute life-threating complications such as ischemic stroke, acute myocardial infarction, deep venous thrombosis and pulmonary embolism are responsible for more than 25% of all deaths worldwide. The modern approach following progresses in anticoagulant, thrombolytic and antiaggregant therapies has significantly improved the prognoses of these conditions in the last past decades. However, several challenges still remain such as achieving the optimal drug concentration at the injured site, reducing the shortcomings of drug resistance and the incidence of life-threatening hemorrhages. Nanomedicine is a well-known field of medicine in which atomic and molecular structures ranging between 0.1–100 nm are used in various domains due to their specific mechanical, electrical, thermal and magnetic properties. Recent experimental and clinical evidence have shown that nanotechnology could be a safe, effective and an appealing approach for various non-cardiovascular and cardiovascular diseases such as thromboembolic conditions. In this review, we have described the most promising nanotechnology-based approaches not only for the diagnosis, but also for the treatment of vascular thrombotic diseases.

Anti-coagulation and anti-hyperplasia coating for retrievable vena cava filters by electrospraying and their performance in vivo

A novel drug eluting retrievable vena cava filter (RVCF) with a heparin-modified poly(ε-caprolactone) (hPCL) coating containing rapamycin was prepared by electrospraying. The in vitro drug release pattern showed that the encapsulated rapamycin in the coating can be sustainably released within one month, whereas activated partial thromboplastin time (APTT) and in vitro cell culture showed that the drug eluting RVCF can effectively extend blood clotting time and inhibit smooth muscle cell (SMC) and endothelial cell (EC) proliferation, respectively. The as-prepared drug eluting RVCF and corresponding commercial RVCF were implanted into the vena cava of sheep. The retrieval operation at a predetermined time point showed that the drug eluting RVCF had a much higher retrieval rate than the commercial RVCF. Comprehensive investigations, including histological, immunohistological and immunofluorescence analyses, on explanted veins were carried out. The results demonstrated that the as-prepared RVCF possessed excellent antihyperplasia properties in vivo, significantly improving the retrieval rate and extending the in vivo dwelling time in sheep. Consequently, the drug eluting RVCF has promising potential for application in the clinic to improve RVCF retrieval rates.

Upregulated miR-206 Aggravates Deep Vein Thrombosis by Regulating GJA1-Mediated Autophagy of Endothelial Progenitor Cells

Background

Deep vein thrombosis (DVT) is the third most prevalent vascular disease worldwide. MicroRNAs (miRNAs) play regulatory roles in functions of endothelial progenitor cells (EPCs), which is becoming a promising therapeutic choice for thrombus resolution. Nevertheless, the role of miR-206 in EPCs is unclear.

Methods

EPCs were isolated from the peripheral blood of patients with DVT. In DVT mouse models, DVT was induced by stenosis of the inferior vena cava (IVC). The levels of miR-206 and gap junction protein alpha 1 (GJA1) in EPCs and vascular tissues of DVT mice were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The proliferation, migration, apoptosis, and angiogenesis were tested by cell counting kit-8 (CCK-8) assay, Transwell assay, flow cytometry analysis, and in vitro tube formation assay. The levels of autophagy-related proteins as well as the level of GJA1 in EPCs and vascular tissues were evaluated by western blotting. DVT formation in vivo was observed through hematoxylin-eosin (HE) staining. The expression of thrombus resolution markers, CD34 molecule (CD34) and matrix metallopeptidase 2 (MMP2), in the thrombi was measured by immunofluorescence staining.

Results

miR-206 overexpression inhibited proliferation, migration, and angiogenesis and promoted apoptosis of EPCs, while miR-206 knockdown exerted an opposite effect on EPC phenotypes. Downregulation of GJA1, the target of miR-206, abolished the influence of miR-206 on EPC phenotypes. Furthermore, silencing of miR-206 suppressed the autophagy of EPCs via upregulating GJA1. miR-206 knockdown repressed thrombus formation, enhanced the homing ability of EPCs to the thrombosis site, and facilitated thrombus resolution in DVT mouse models. Additionally, miR-206 was upregulated while GJA1 was downregulated in vascular tissues of DVT mice. miR-206 knockdown elevated GJA1 expression in vascular tissues of DVT mice. The expression of miR-206 was negatively correlated with that of GJA1 in DVT mice.

Conclusion

miR-206 knockdown upregulates GJA1 to inhibit autophagy of EPCs and then promote EPC proliferation, migration, and angiogenesis, thereby enhancing EPC homing to thrombi and facilitating thrombus resolution.

Nurses’ Knowledge, Perceived Practice, and their Associated Factors regarding Deep Venous Thrombosis (DVT) Prevention in Amhara Region Comprehensive Specialized Hospitals, Northwest Ethiopia, 2021: A Cross-Sectional Study

Introduction

Deep venous thrombosis is a preventable and treatable cause of death among hospitalized patients. Nurses' knowledge and proper assessment can play a major role in improving deep venous thrombosis prevention care.

Objective

To assess the knowledge, practice, and associated factors towards deep venous thrombosis prevention among nurses working at Amhara region hospitals.

Methods

Institutional-based cross-sectional study was conducted among nurses working at Amhara region comprehensive specialized hospitals, Northwest, Ethiopia, from April 1 to 30, 2021. A simple random sampling technique was used to select 423 samples. A structured pretested self-administered questionnaire was used to collect data. Data were entered in epi-info version 7, analyzed using SPSS version 25, and presented by frequencies, percentages, and tables. Bivariable and multivariable logistic regression was computed, and P value < 0.05 was considered to identify statistically significant factors.

Result

Good knowledge and practice of nurses towards DVT prevention were 55.6% and 48.8%, respectively. Working at the medical ward [AOR 3.175, 95% CI (1.42, 7.11)], having a BSc degree [AOR = 3.248(1.245, 8.469)], Master's degree [AOR = 3.48, 95% CI (1.22, 9.89)], obtaining a formal training about deep venous thrombosis [AOR = 1.59; 95% CI (1.03, 2.47)], and working experience of ≥11 years [AOR = 2.11; 95% CI (1.07, 4.16)] were associated with good knowledge of nurses on the prevention of deep venous thrombosis. While having good knowledge about deep venous prevention AOR = 1.75; 95% CI (1.15, 2.65)] and working experience ≥11 years [AOR = 3.44; 95% CI (1.45, 8.13)] were significantly associated with nurses' practice about deep venous thrombosis prevention.

Conclusion

Knowledge and practice of the nurses regarding the prevention of deep venous thrombosis were found to be inadequate. Therefore, providing training, creating a conducive environment for sharing of experience, and upgrading the academic status of nurses are measures to scale up the knowledge and practice of nurses regarding deep venous thrombosis prevention.

Acute neurological deficit with submassive pulmonary emboli

Pulmonary embolism (PE) is frequently encountered in the emergency department. Syncope, often as a consequence of impending haemodynamic collapse, is associated with increased mortality. While loss of consciousness owing to cerebral hypoperfusion and reduced left ventricular preload is a common cause of collapse with large volume PE, other syndromes can also cause neurological deficit in thromboembolic disease. Here, we describe a case of a woman in her 60s, presenting to the emergency department with features of high-risk PE. During clinical examination, the patient collapsed and became unresponsive with a Glasgow Coma Scale of 4/15 despite normal haemodynamics. Neurological signs were noted and CT revealed evidence of a large territory cerebral infarction. Further cardiovascular investigations identified a grade 4 patent foramen ovale. We describe a challenging case of established venous thromboembolism complicated by paradoxical embolism, highlighting the importance of thorough clinical examination and investigation and discuss the current evidence base of treatments.

Automated detection of pulmonary embolism from CT-angiograms using deep learning

Background

The aim of this study was to develop and evaluate a deep neural network model in the automated detection of pulmonary embolism (PE) from computed tomography pulmonary angiograms (CTPAs) using only weakly labelled training data.

Methods

We developed a deep neural network model consisting of two parts: a convolutional neural network architecture called InceptionResNet V2 and a long-short term memory network to process whole CTPA stacks as sequences of slices. Two versions of the model were created using either chest X-rays (Model A) or natural images (Model B) as pre-training data. We retrospectively collected 600 CTPAs to use in training and validation and 200 CTPAs to use in testing. CTPAs were annotated only with binary labels on both stack- and slice-based levels. Performance of the models was evaluated with ROC and precision–recall curves, specificity, sensitivity, accuracy, as well as positive and negative predictive values.

Results

Both models performed well on both stack- and slice-based levels. On the stack-based level, Model A reached specificity and sensitivity of 93.5% and 86.6%, respectively, outperforming Model B slightly (specificity 90.7% and sensitivity 83.5%). However, the difference between their ROC AUC scores was not statistically significant (0.94 vs 0.91, p = 0.07).

Conclusions

We show that a deep learning model trained with a relatively small, weakly annotated dataset can achieve excellent performance results in detecting PE from CTPAs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12880-022-00763-z.

Prevalence of Pulmonary Embolism and Deep Venous Thromboembolism in Patients With Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

Background

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) increases the risk of pulmonary embolism (PE) and deep venous thrombosis (DVT). AECOPD combined with PE and DVT poses challenges for treatment and management. This necessitates prevention and management to estimate the overall prevalence of PE and DVT among patients with AECOPD and to identify the risk factors.

Methods

We searched the PubMed, Embase, and Cochrane Library databases from their inception to January 9, 2021 and extracted the data from the included studies. The risk of bias was assessed for each study. We separately calculated the prevalence of PE and DVT in patients with AECOPD. Subgroup analysis and meta-regression analyses were performed to determine the sources of heterogeneity. Furthermore, we assessed the publication bias.

Results

The meta-analysis included 20 studies involving 5,854 people. The overall prevalence of PE and DVT among patients with AECOPD was 11% (95% CI: 0.06–0.17) and 9% (95% CI: 0.06–0.12), respectively. Subgroup analysis demonstrated that the prevalence of PE among patients with AECOPD was 12, 2, 7, and 16% in the European, South-East Asia, Western Pacific, and Eastern Mediterranean regions, respectively, and the DVT was 10, 9, 9, and 4%, respectively. The prevalence of PE among patients with AECOPD aged ≥ 70 and <70 years old was 6 and 15%, respectively, and the DVT was 8 and 9%, respectively. The prevalence of PE among patients with AECOPD diagnosed within 48 h and other times (beyond 48 h or not mentioned) was 16 and 6%, respectively, and DVT was 10 and 7%, respectively.

Conclusion

The pooled prevalence of PE and DVT among patients with AECOPD was insignificantly different between the different age groups and the WHO regions. However, the early diagnosis was associated with a higher prevalence of PE. Clinicians and the public need to further improve the awareness of prevention and management for PE and DVT among patients with AECOPD.

Systematic Review Registration

PROSPERO, identifier CRD42021260827.

Comparative Study of Diagnostic Efficacy of Single Phase-Computed Tomography Pulmonary Angiography and Dual Phase-Computed Tomography Pulmonary Angiography in the Diagnosis of Pulmonary Embolism

Objective

We compared the efficacy of single phase-computed tomography pulmonary angiography (SP-CTPA) and dual phase-computed tomography pulmonary angiography (DP-CTPA) for the diagnosis of pulmonary embolism (PE).

Methods

We recruited 1,019 consecutive patients (359 with PE) who underwent DP-CTPA (phase I: pulmonary artery phase; phase II: aortic phase) for suspected PE between January and October 2021. Phase I of DP-CTPA was used as SP-CTPA, and the final clinical diagnosis (FCD) was used as the gold standard.

Results

Three hundred fifty-two cases of PE were detected by both methods, with the same sensitivity of 98.1% (99.6–99.5%). Using SP-CTPA, 142 cases [13 pulmonary insufficiency artifacts (PIA) and 129 systemic-pulmonary shunt artifacts (S-PSA)] were false-positive with specificity of 78.5% (75.3–81.6%). No false-positive was found with DP-CTPA, with specificity of 100%, positive predictive value of 1, and negative predictive value of 0.990 (Net Reclassification Improvement = 0.215; P < 0.05). According to FCD, the positive results of SP-CTPA were divided into PIA, S-PSA, and true-positive (TP_SP−CTPA) groups, and pairwise comparisons were performed. The bronchiectasis and hemoptysis rate in S-PSA group was higher than that in PIA and TP groups (P < 0.001), and the pulmonary hypertension (PH) rate in PIA group was higher than that in S-PSA and TP groups (P < 0.001).

Conclusion

The diagnostic efficiency of DP-CTPA for the diagnosis of PE was high. SP-CTPA may misdiagnose PIA (common in patients with PH) and S-PSA (common in patients with bronchiectasis and hemoptysis) as PE.

Chitosan/Alginate Nanoparticles for the Enhanced Oral Antithrombotic Activity of Clam Heparinoid from the Clam Coelomactra antiquata

Chitosan/alginate nanoparticles (DG1-NPs and DG1/Cur-NPs) aiming to enhance the oral antithrombotic activity of clam heparinoid DG1 were prepared by ionotropic pre-gelation. The influence of parameters, such as the concentration of sodium alginate (SA), chitosan (CTS), CaCl2, clam heparinoid DG1, and curcumin (Cur), on the characteristics of the nanoparticles, were investigated. Results indicate that chitosan and alginate can be used as polymer matrices to encapsulate DG1, and nanoparticle characteristics depend on the preparation parameters. Nano-particles should be prepared using 0.6 mg/mL SA, 0.33 mg/mL CaCl2, 0.6 mg/mL CTS, 7.2 mg/mL DG1, and 0.24 mg/mL Cur under vigorous stirring to produce DG1-NPS and DG1/Cur-NPS with small size, high encapsulation efficiency, high loading capacity, and negative zeta potential from approximately −20 to 30 mV. Data from scanning electron microscopy, Fourier-transform infrared spectrometry, and differential scanning calorimetry analyses showed no chemical reaction between DG1, Cur, and the polymers; only physical mixing. Moreover, the drug was loaded in the amorphous phase within the nanoparticle matrix. In the acute pulmonary embolism murine model, DG1-NPs enhanced the oral antithrombotic activity of DG1, but DG1/Cur-NPs did not exhibit higher antithrombotic activity than DG1-NPs. Therefore, the chitosan/alginate nanoparticles enhanced the oral antithrombotic activity of DG1, but curcumin did not further enhance this effect.

Neutrophil Extracellular Traps in Atherosclerosis and Thrombosis

Despite effective therapeutic and preventive strategies, atherosclerosis and its complications still represent a substantial health burden. Leukocytes and inflammatory mechanisms are increasingly recognized as drivers of atherosclerosis. Neutrophil granulocytes within the circulation were recently shown to undergo neutrophil extracellular trap (NET) formation, linking innate immunity with acute complications of atherosclerosis. In this chapter, we summarize mechanisms of NET formation, evidence for their involvement in atherosclerosis and thrombosis, and potential therapeutic regimens specifically targeting NET components.

Potential Adverse Events Reported With the Janus Kinase Inhibitors Approved for the Treatment of Rheumatoid Arthritis Using Spontaneous Reports and Online Patient Reviews

The aim of this study was to analyze the potential adverse events (AEs) caused by Janus kinase (JAK) inhibitors, including tofacitinib, baricitinib, and upadacitinib, used to treat rheumatoid arthritis using spontaneous AE reports from the FDA (FAERS) and interpreting them in correlation with those from Korea (KAERS) and an online patient review (WebMD). Potential AEs were identified based on a disproportionality analysis using the proportional reporting ratio (PRR), reporting odds ratio (ROR), and the information component (IC). A total of 23,720 reports were analyzed from FAERS database, of which 91.5% were reports on tofacitinib. Potentially important medical AEs related to infections were reported frequently, as well as thromboembolism-related AEs. The AEs, such as malignancy, interstitial lung diseases, myocardial infarction, and gastrointestinal disorder, also reported. In an online patient review report, the ineffectiveness of the drug and gastrointestinal AEs were frequently reported. Infection with baricitinib and symptoms related to pain or edema due to upadacitinib were the main discomfort experienced by patients. In conclusion, the results of this study highlight the possible safety issues associated with JAK inhibitors. Routine clinical observations and further research using various real-world databases are needed.

Investigating the Source of Fatal Pulmonary Thromboembolism in a Coronial Postmortem Population

ABSTRACT

The incidence of how often a deep vein thrombosis is found in the calves of the legs at coronial postmortem examination is unclear. This study retrospectively examined postmortem examination reports from Australian Coronial investigations of sudden death resulting from pulmonary thromboembolism to determine the likelihood of dissection of the deep veins of calves of the legs revealing the source of a pulmonary thromboembolism. From 450 cases taken from the National Coronial Information System (NCIS) for 2016, the postmortem reports of 327 cases were reviewed to provide demographic details of victims of sudden death from pulmonary thromboembolism. In 235 cases, it was possible to determine in 76.6% a thrombus had been found in the deep veins of the calves of the legs after dissection. In 141 cases, it was documented that both sides had been examined. From these, it was determined there was no statistically significant difference in the prevalence of thrombus in either side. However, it was shown that the presence of an abnormality of a lower limb (such as leg or hip infection, burns, surgery and nonoperated fractures, or a larger circumference) increased the likelihood that a deep vein thrombus would be found on that side.

Conversion from dose-length product to effective dose in computed tomography venography of the lower extremities

For radiation dose assessment of computed tomography (CT), effective dose (ED) is often estimated by multiplying the dose-length product (DLP), provided automatically by the CT scanner, by a conversion factor. We investigated such conversion in CT venography of the lower extremities performed in conjunction with CT pulmonary angiography. The study subjects consisted of eight groups imaged using different scanners and different imaging conditions (five and three groups for the GE and Siemens scanners, respectively). Each group included ten men and ten women. The scan range was divided into four anatomical regions (trunk, proximal thigh, knee and distal leg), and DLP was calculated for each region (regional DLP). Regional DLP was multiplied by a conversion factor for the respective region, to convert it to ED. The sum of the ED values for the four regions was obtained as standard ED. Additionally, the sum of the four regional DLP values, an approximate of the scanner-derived DLP, was multiplied by the conversion factor for the trunk (0.015 mSv mGy cm^-1), as a simplified method to obtain ED. When using the simplified method, ED was overestimated by 32.3%-70.2% and 56.5%-66.2% for the GE and Siemens scanners, respectively. The degree of overestimation was positively and closely correlated with the contribution of the middle and distal portions of the lower extremities to total radiation exposure. ED/DLP averaged within each group, corresponding to the conversion factor, was 0.0089-0.0114 and 0.0091-0.0096 mSv mGy cm^-1for the GE and Siemens scanners, respectively. In CT venography of the lower extremities, ED is greatly overestimated by multiplying the scanner-derived DLP by the conversion factor for the trunk. The degree of overestimation varies widely depending on the imaging conditions. It is recommended to divide the scan range and calculate ED as a sum of regional ED values.

Comparison between Deep Learning and Conventional Machine Learning in Classifying Iliofemoral Deep Venous Thrombosis upon CT Venography

In this study, we aimed to investigate quantitative differences in performance in terms of comparing the automated classification of deep vein thrombosis (DVT) using two categories of artificial intelligence algorithms: deep learning based on convolutional neural networks (CNNs) and conventional machine learning. We retrospectively enrolled 659 participants (DVT patients, 282; normal controls, 377) who were evaluated using contrast-enhanced lower extremity computed tomography (CT) venography. Conventional machine learning consists of logistic regression (LR), support vector machines (SVM), random forests (RF), and extreme gradient boosts (XGB). Deep learning based on CNN included the VGG16, VGG19, Resnet50, and Resnet152 models. According to the mean generated AUC values, we found that the CNN-based VGG16 model showed a 0.007 higher performance (0.982 ± 0.014) as compared with the XGB model (0.975 ± 0.010), which showed the highest performance among the conventional machine learning models. In the conventional machine learning-based classifications, we found that the radiomic features presenting a statistically significant effect were median values and skewness. We found that the VGG16 model within the deep learning algorithm distinguished deep vein thrombosis on CT images most accurately, with slightly higher AUC values as compared with the other AI algorithms used in this study. Our results guide research directions and medical practice.

Development and validation of a prediction model to estimate risk of acute pulmonary embolism in deep vein thrombosis patients

Venous thromboembolism (VTE), clinically presenting as deep vein thrombosis (DVT) or pulmonary embolism (PE). Not all DVT patients carry the same risk of developing acute pulmonary embolism (APE). To develop and validate a prediction model to estimate risk of APE in DVT patients combined with past medical history, clinical symptoms, physical signs, and the sign of the electrocardiogram. We analyzed data from a retrospective cohort of patients who were diagnosed as symptomatic VTE from 2013 to 2018 (n = 1582). Among them, 122 patients were excluded. All enrolled patients confirmed by pulmonary angiography or computed tomography pulmonary angiography (CTPA) and compression venous ultrasonography. Using the LASSO and logistics regression, we derived a predictive model with 16 candidate variables to predict the risk of APE and completed internal validation. Overall, 52.9% patients had DVT + APE (773 vs 1460), 47.1% patients only had DVT (687 vs 1460). The APE risk prediction model included one pre-existing disease or condition (respiratory failure), one risk factors (infection), three symptoms (dyspnea, hemoptysis and syncope), five signs (skin cold clammy, tachycardia, diminished respiration, pulmonary rales and accentuation/splitting of P₂), and six ECG indicators (S_IQ_IIIT_III, right axis deviation, left axis deviation, S₁S₂S₃, T wave inversion and Q/q wave), of which all were positively associated with APE. The ROC curves of the model showed AUC of 0.79 (95% CI, 0.77–0.82) and 0.80 (95% CI, 0.76–0.84) in the training set and testing set. The model showed good predictive accuracy (calibration slope, 0.83 and Brier score, 0.18). Based on a retrospective single-center population study, we developed a novel prediction model to identify patients with different risks for APE in DVT patients, which may be useful for quickly estimating the probability of APE before obtaining definitive test results and speeding up emergency management processes.

Mapping Trends and Hotspots Regarding the Use of Ultrasound in Emergency Medicine: A Bibliometric Analysis of Global Research

Objective: Diagnostic tools in emergency medicine have been widely studied. As a non-invasive and quick tool, ultrasound plays a role in the field of emergency medicine. Thus, it is significant to understand the global scientific output of this topic. An analysis of publications on the use of ultrasound in emergency medicine over the past decade was performed and summarized to track the current hotspots and highlight future directions.

Methods: Globally relevant publications on ultrasound in emergency medicine from 2009 to 2020 were extracted from the Web of Science collection database. VOSviewer software and CiteSpace were employed to visualize and predict the trends in the research on the topic.

Results: The overall volume of global publications is on the rise; furthermore, the United States published the most publications in this field and had the most citations and H-index. University of California at San Francisco in the United States has most publications in terms of institutions. The American Journal of Emergency Medicine published the most papers related to ultrasound in emergency medicine in terms of journals. Pulmonary embolism was once the main research direction, and importantly, “point-of-care ultrasound” was determined to be a new research hotspot.

Conclusion: Altogether, the number of publications on ultrasound in emergency medicine will rise in the future. In addition, the findings reported here shed new light on the major progress on ultrasound in emergency medicine, which may be mutually cooperative in various fields. Moreover, this bibliometric study provides further indications for the topic of “point-of-care ultrasound”.

Comparison of Anti-factor Xa Levels in Female and Male Patients with Obesity After Enoxaparin Application for Thromboprophylaxis

Purpose

Venous thromboembolic events (VTEs) are common complications after bariatric surgery, and enoxaparin is commonly used to prevent VTEs. The risk for VTEs is sex-specific. Whether enoxaparin application results in similar anti-factor Xa activities (aFXa) in males and females with obesity remains to be determined. We investigated whether our dosage regimen of enoxaparin resulted in similar serum aFXa levels in female and male patients undergoing bariatric surgery.

Materials and Methods

We administered enoxaparin twice daily in patients undergoing bariatric surgery. Patients with a body mass index (BMI) > 60 kg/m² (n = 11) received 60 mg enoxaparin (group 2), and patients with lower BMI (n = 86) received 40 mg per dose (group 1). Peak aFXa levels were measured 3 days after surgery. The primary outcome was the aFXa level. As a secondary outcome, we detected VTEs and major bleeding events and explored the possible influencing factors of aFXa.

Results

Women had higher aFXa than men, but after matching for anthropometric values, the two groups were similar (females: 0.17 ± 0.08 U/ml; males: 0.18 ± 0.08 U/ml). Linear regression revealed a moderate relationship between weight and aFXa levels. The 3-month follow-up was attended by 94.9%, at which one patient had pulmonary embolism.

Conclusion

Individual enoxaparin dosage regimens for men and women do not seem to be required. Weight-based dosing regimen seems to be a more reasonable choice.

Graphical abstract

Effectiveness and safety of oral anticoagulants in the treatment of acute venous thromboembolism: A nationwide comparative cohort study in France

INTRODUCTION

Data from clinical trials indicate that direct oral anticoagulants (DOACs) are non-inferior and safer than conventional therapy (low-molecular weight heparin followed by a vitamin K antagonist [VKA]) for treating venous thromboembolism (VTE), which includes deep vein thrombosis and pulmonary embolism (PE). This study compared the effectiveness and safety of DOACs and conventional therapy in a real-world setting.

MATERIALS AND METHODS

This observational study used French national claims data of adult, treatment-naïve patients diagnosed with VTE (majority PE) who were hospitalized and treated for VTE with a DOAC (apixaban or rivaroxaban) or VKAs during 2013-2018. Patients with active cancer were excluded. After propensity score matching for each DOAC-VKA comparison, risks of bleeding, recurrent VTE, and all-cause mortality were compared at 6 months. Cox proportional-hazards regression was used to estimate adjusted hazard ratios of the endpoints.

RESULTS

58137 patients were included (10775 VKAs, 10440 apixaban, 36922 rivaroxaban). Propensity score-matched cohort sizes were 7503 for apixaban and 9179 for rivaroxaban. The hazard ratio (95% confidence interval) was significantly lower for apixaban than VKAs for bleeding requiring hospitalization (0.43 [0.32-0.59]), all-cause death (0.61 [0.51-0.74]), and first-recurrent VTE (0.67 [0.52-0.85]). The hazard ratio was also significantly lower for rivaroxaban than VKAs for all-cause death (0.63 [0.53-0.74]) but not for bleeding requiring hospitalization (0.86 [0.69-1.07]) or first-recurrent VTE (0.91 [0.74-1.13]).

CONCLUSIONS

Apixaban was associated with superior safety and effectiveness than VKAs. All-cause mortality was lower in both DOACs than VKAs. Our results support recommendations to use DOACs over VKAs for the treatment of VTE.

The Correlation Between Preoperative Lower Extremity Deep Vein Thrombosis (DVT) and the Time from Injury to Surgery (TFITS)

Objective

To investigate the correlation between preoperative DVT and the time from injury to surgery (TFITS), and provide a clinical reference for the prevention of preoperative DVT.

Patients and methods

We collected the clinical data of patients with lower extremities fractures between September 1, 2014, and May 31, 2019. Doppler ultrasonography was used to diagnose DVT. Patients were divided into the 0-2d group, 3-4d group, 5-7d group, and >7d group according to TFITS. The correlation between TFITS and preoperative DVT was assessed using logistic regression according to the adjusted model.

Result

A total of 2831 patients were included in the study. The mean（+/-SD） TFITS was 6.11 ± 3.76 (0 to 21 d). A total of 821 (29.0%) cases had preoperative DVT, with the incidence of DVT being 8.0% in the 0-2d group, 23.8% in the 3-4d group, 32.0% in the 5-7d group, and 36.2% in the >7d group, with statistically significant differences(P＜0.05) among all the groups. The incidence of preoperative DVT increased with prolonged preoperative time. In the fully adjusted model, TFITS was positively correlated with the incidence of preoperative DVT (OR: 1.093; 95% CI: 1.068-1.118; P = 0.000), and the strength of the association increased with increasing time.

Conclusion

TFITS was an independent risk factor on the incidence of preoperative DVT. After excluding the effect of other factors, each 1d increases in TFITS was correlated with a 9.3% increase in the risk of preoperative DVT. The TFITS should be decreased to reduce the risk of preoperative DVT.

Formononetin regulates endothelial nitric oxide synthase to protect vascular endothelium in deep vein thrombosis rats

OBJECTIVE

Formononetin is a bioactive isoflavone that has numerous medicinal benefits. We explored the feasibility and its mechanism of formononetin on treating acute deep vein thrombosis (DVT) in rats.

MATERIALS AND METHODS

Inferior vena cava (IVC) stenosis was performed to establish the DVT rat model. First, different doses of formononetin were used to observe the feasibility of formononetin on treating DVT. In sham and DVT groups, rats were orally treated with vehicle. In the remaining groups, formononetin (10 mg/kg, 20 mg/kg, and 40 mg/kg) was orally treated once a day for 7 days at 24 h after IVC. After 7 days, the levels of thrombosis and inflammation related factors in plasma were measured. The expression of endothelial nitric oxide synthase (eNOS) was analyzed by western blot and immunofluorescence. Molecular docking was used to evaluate the interaction between the formononetin and eNOS. Further, the NOS inhibitor (L-NAME) was used to explore the mechanism of formononetin for DVT.

RESULT

After treatment with formononetin, the average weights of thrombosis were decreased, and the levels of thrombosis and inflammation related factors were also significantly decreased. Additionally, phosphorylation of eNOS was increased with the formononetin administration. There is a good activity of formononetin to eNOS (total score = -6.8). However, the effects of 40 mg/kg formononetin were concealed by the NOS inhibitor (L-NAME).

CONCLUSION

Formononetin reduces vascular endothelium injury induced by DVT through increasing eNOS in rats, which provides a potential drug for treatment of venous thrombosis.

Isoprostane-8 and GDF-15 as novel markers of post-PE syndrome: Relation with prothrombotic factors

BACKGROUND

Post-pulmonary embolism (PE) syndrome occurs in up to 50% of PE patients. The pathophysiology of this syndrome is obscure.

OBJECTIVE

We investigated whether enhanced oxidative stress and prothrombotic state may be involved in post-PE syndrome.

METHODS

We studied 101 normotensive noncancer PE patients (aged 56.5 ± 13.9 years) on admission, after 5-7 days and after a 3-month anticoagulation, mostly with rivaroxaban. A marker of oxidative stress, 8-isoprostane, endogenous thrombin potential, fibrinolysis proteins, clot lysis time (CLT) and fibrin clot permeability (K_s ), along with PE biomarkers, were determined.

RESULTS

Patients who developed the post-PE syndrome (n = 31, 30.7%) had at baseline 77.6% higher N-terminal brain natriuretic propeptide and 46.8% higher growth differentiation factor 15, along with 14.1% longer CLT associated with 34.4% higher plasminogen activator inhibitor-1 as compared to subjects without post-PE syndrome (all P < .05). After 5-7 days, only hypofibrinolysis was noted in post-PE syndrome patients. When measured at 3 months, prolonged CLT and reduced K_s were observed in post-PE syndrome patients, accompanied by 23.8% higher growth differentiation factor 15 and 35.8% higher plasminogen activator inhibitor-1 (all P < .05). 8-isoprostane levels ≥108 pg/ml (odds ratio=4.36; 95% confidence interval 1.63-12.27) and growth differentiation factor 15 ≥ 1529 pg/ml (odds ratio=3.89; 95% confidence interval 1.29-12.16) measured at 3 months were associated with higher risk of developing post-PE syndrome.

CONCLUSIONS

Enhanced oxidative stress and prothrombotic fibrin clot properties could be involved in the pathogenesis of the post-PE syndrome. Elevated growth differentiation factor 15 assessed at 3 months might be a new biomarker of this syndrome.

Deep Learning for Accurate Segmentation of Venous Thrombus from Black-Blood Magnetic Resonance Images: A Multicenter Study

Objective

Deep vein thrombosis (DVT) is the third-largest cardiovascular disease, and accurate segmentation of venous thrombus from the black-blood magnetic resonance (MR) images can provide additional information for personalized DVT treatment planning. Therefore, a deep learning network is proposed to automatically segment venous thrombus with high accuracy and reliability.

Methods

In order to train, test, and external test the developed network, total images of 110 subjects are obtained from three different centers with two different black-blood MR techniques (i.e., DANTE-SPACE and DANTE-FLASH). Two experienced radiologists manually contoured each venous thrombus, followed by reediting, to create the ground truth. 5-fold cross-validation strategy is applied for training and testing. The segmentation performance is measured on pixel and vessel segment levels. For the pixel level, the dice similarity coefficient (DSC), average Hausdorff distance (AHD), and absolute volume difference (AVD) of segmented thrombus are calculated. For the vessel segment level, the sensitivity (SE), specificity (SP), accuracy (ACC), and positive and negative predictive values (PPV and NPV) are used.

Results

The proposed network generates segmentation results in good agreement with the ground truth. Based on the pixel level, the proposed network achieves excellent results on testing and the other two external testing sets, DSC are 0.76, 0.76, and 0.73, AHD (mm) are 4.11, 6.45, and 6.49, and AVD are 0.16, 0.18, and 0.22. On the vessel segment level, SE are 0.95, 0.93, and 0.81, SP are 0.97, 0.92, and 0.97, ACC are 0.96, 0.94, and 0.95, PPV are 0.97, 0.82, and 0.96, and NPV are 0.97, 0.96, and 0.94.

Conclusions

The proposed deep learning network is effective and stable for fully automatic segmentation of venous thrombus on black blood MR images.

Effect of a Multidisciplinary Pulmonary Embolism Response Team on Patient Mortality

Multidisciplinary Pulmonary Embolism Response Teams (PERTs) may improve the care of patients with a high risk of pulmonary embolism (PE). The impact of a PERT on long-term mortality has never been evaluated. An observational analysis was conducted of 137 patients before PERT implementation (between 2014 and 2015) and 231 patients after PERT implementation (between 2016 and 2019), presenting to the emergency department of an academic medical center with submassive and massive PE. The primary outcome was 6-month mortality, evaluated by univariate and multivariate analyses. PERT was associated with a sustained reduction in mortality through 6 months (6-month mortality rates of 14% post-PERT vs 24% pre-PERT, unadjusted hazard ratio of 0.57, Relative Risk Reduction of 43%, p = 0.025). There was a reduced length of stay following PERT implementation (9.1 vs 6.5 days, p = 0.007). Time from triage to a diagnosis of PE was independently predictive of mortality, and the risk of mortality was reduced by 5% for each hour earlier that the diagnosis was made. In conclusion, this study is the first to demonstrate an association between PERT implementation and a sustained reduction in 6-month mortality for patients with high-risk PE.

Morphologic change in deep venous thrombosis in the lower extremity after therapeutic anticoagulation

Background

To evaluate the anticoagulant treatment response in venous thrombi with different morphologies (size, shape, and echogenicity) by measuring the change in thrombus thickness.

Materials and methods

This was a retrospective cohort study of 97 lower extremity DVT patients diagnosed by venous ultrasound between March 2014 and February 2018. The demographics, clinical risk factors, anticoagulant treatment, and ultrasound findings at the first diagnosis and 2–6 months after treatment were evaluated.

Results

The anticoagulant treatment with LMWH followed by VKAs showed a significant decrease in the mean maximum difference in lower extremity DVT thrombus thickness compared with VKAs alone (P-value < 0.001). After adjustment by treatment, the thrombi found in dilated veins showed a significant decrease in the thickness of such thrombi compared with those found in small veins: 4 mm vs. 0 mm (Coef. = 3, 95% CI: 1.9, 4.1 and P-value < 0.001). Anechoic and hypoechoic thrombi showed a significant decrease in the thickness compared with hyperechoic thrombi: 5 mm vs. 0 mm (Coef. = 4, 95% CI: 3.25, 4.74 and P-value < 0.001) and 3 mm vs. 0 mm (Coef. = 2, 95% CI: 1.34, 42.66 and P-value < 0.001), respectively. Concentric thrombi showed a significant decrease in thickness compared with eccentric thrombi: 4 mm vs. 0 mm (Coef. = 2, 95% CI: 1.45, 2.55 and P-value < 0.001).

Conclusion

The anticoagulant treatment with LMWH followed by VKAs shows a significant decrease in lower extremity DVT thrombus thickness compared with VKAs alone. After adjustment by treatment, the morphologic finding of acute thrombi shows a significantly decreased thickness compared with the morphologic finding of chronic thrombi.

Targeting the NLRP3 inflammasome in cardiovascular diseases

The NACHT, leucine-rich repeat (LRR), and pyrin domain (PYD)-containing protein 3 (NLRP3) inflammasome is an intracellular sensing protein complex that plays a major role in innate immunity. Following tissue injury, activation of the NLRP3 inflammasome results in cytokine production, primarily interleukin(IL)-1β and IL-18, and, eventually, inflammatory cell death - pyroptosis. While a balanced inflammatory response favors damage resolution and tissue healing, excessive NLRP3 activation causes detrimental effects. A key involvement of the NLRP3 inflammasome has been reported across a wide range of cardiovascular diseases (CVDs). Several pharmacological agents selectively targeting the NLRP3 inflammasome system have been developed and tested in animals and early phase human studies with overall promising results. While the NLRP3 inhibitors are in clinical development, multiple randomized trials have demonstrated the safety and efficacy of IL-1 blockade in atherothrombosis, heart failure and recurrent pericarditis. Furthermore, the non-selective NLRP3 inhibitor colchicine has been recently shown to significantly reduce cardiovascular events in patients with chronic coronary disease. In this review, we will outline the mechanisms driving NLRP3 assembly and activation, and discuss the pathogenetic role of the NLRP3 inflammasome in CVDs, providing an overview of the current and future therapeutic approaches targeting the NLRP3 inflammasome.

Vascular Thrombosis and Anti-PD-1 Therapy: A Series of Cases

Immune checkpoint inhibitors may cause unique immune-related adverse events. Vascular thrombosis, especially arterial thrombosis, is rare but life-threatening, and little is known about its relevance to immunotherapy. Here, we reported two cases of vascular thrombosis, including venous and arterial thrombosis in cancer patients receiving anti-PD-1 antibody in combination with chemotherapy. Systemic corticosteroids and anticoagulant treatment were administered immediately in two cases. In case 1, anti-PD-1 antibody was permanently discontinued, and recurrence of vascular thrombosis was not observed during the follow-up. In case 2, the patient continued anti-PD-1 immunotherapy and unfortunately died of cerebral infarction 2 months later. This case report provides a strong evidence for the association between PD-1 blockade and vascular thrombosis and offers some general guidelines on the management of the immune-related vascular thrombosis events induced by anti-PD-1 therapy.