Recurrence and mortality after first venous thromboembolism in a large population-based cohort

Risk of incident venous thromboembolism in patients with atopic dermatitis: systematic analysis of the literature and meta-analysis

Atopic dermatitis (AD) is a prevalent chronic inflammatory skin disease. While various inflammatory conditions have been linked to venous thromboembolism (VTE), the risk of VTE among patients with AD remains unclear. We sought to systematically review and meta-analyze population-based studies to determine the association between AD and incident VTE. A systematic review was performed of published studies in PubMed, Web of Science, Embase and Cochrane library from their inception to 27 May 2024. At least two reviewers conducted title/abstract, full-text review and data extraction. Cohort studies examining the association of AD with incident VTE were included. Quality of evidence was assessed using the Newcastle-Ottawa Scale. Six cohort studies, encompassing a total of 10,186,861 participants, were included. The meta-analysis revealed a significantly increased risk for incident VTE among AD patients (pooled hazard ratio (HR), 1.10; 95% CI, 1.00-1.21), with an incidence rate of VTE at 3.35 events per 1000 patient-years. Individual outcome analyses suggested that AD was associated with higher risks of deep vein thrombosis (pooled HR, 1.15; 95% CI, 1.04-1.27) but not pulmonary embolism (pooled HR, 0.99; 95% CI, 0.87-1.13). This systematic review and meta-analysis indicated an increased risk of incident VTE among patients with AD. Future studies are necessary to elucidate the underlying pathophysiology of the association between AD and VTE.

Statins use and recurrent venous thromboembolism in the direct oral anticoagulant era: insight from the COMMAND VTE Registry-2

Statins were reported to have a potential effect of primary prevention of venous thromboembolism (VTE), although that of secondary prevention remains uncertain. To investigate the association between statins use and recurrent VTE in the current era. The COMMAND VTE Registry-2 is a multicenter registry enrolling 5,197 consecutive VTE patients among 31 centers in Japan between January 2015 and August 2020. We divided the entire cohort into 2 groups according to statins use at the time of discharge; the statins (N = 865) and no statins groups (N = 4332). The statins group was older (72.9 vs. 66.7 years, P < 0.001), and less often had active cancer (22.0% vs. 30.4%, P < 0.001). The cumulative incidence of discontinuation of anticoagulation was significantly lower in the statins group (60.3% vs. 52.6%, Log-rank P < 0.001). The cumulative 5-year incidence of recurrent VTE was significantly lower in the statins group (6.8% vs. 10.1%, Log-rank P = 0.01). Even after adjusting for the confounders, the lower risk of the statins group relative to the no statins group remained significant for recurrent VTE (HR 0.65, 95% CI 0.45-0.91, P = 0.01). The cumulative 5-year incidence of major bleeding was significantly lower in the statins group (12.2% vs. 14.1%, Log-rank P = 0.04), although, after adjusting for the confounders, the risk of the statins group relative to the no statins group turned to be insignificant (HR 0.77, 95% CI 0.59-1.00, P = 0.054). In this large real-world VTE registry, statins use was significantly associated with a lower risk for the recurrent VTE in the current era.

Thrombotic microenvironment responsive crosslinking cyclodextrin metal-organic framework nanocarriers for precise targeting and thrombolysis

Global public health is seriously threatened by thrombotic disorders because of their high rates of mortality and disability. Most thrombolytic agents, especially protein-based pharmaceuticals, have a short half-life in circulation, reducing their effectiveness in thrombolysis. The creation of an intelligent drug delivery system that delivers medication precisely and releases it under regulated conditions at nearby thrombus sites is essential for effective thrombolysis. In this article, we present a unique medication delivery system (MCRUA) that selectively targets platelets and releases drugs by stimulation from the thrombus' microenvironment. The thrombolytic enzyme urokinase-type plasminogen-activator (uPA) and the anti-inflammatory medication Aspirin (acetylsalicylic acid, ASA) are both loaded onto pH-sensitive CaCO3/cyclodextrin crosslinking metal-organic frameworks (MC) that make up the MCRUA system. c(RGD) is functionalized on the surface of MC, which is functionalized by RGD to an esterification reaction. Additionally, the thrombus site's acidic microenvironment causes MCRUA to disintegrate to release uPA for thrombolysis and aiding in vessel recanalization. Moreover, cyclodextrin-encapsulated ASA enables the treatment of the inflammatory environment within the thrombus, enhancing the antiplatelet aggregation effects and promoting cooperative thrombolysis therapy. When used for thrombotic disorders, our drug delivery system (MCRUA) promotes thrombolysis, suppresses rethrombosis, and enhances biosafety with fewer hemorrhagic side effects.

Circulating Blood Biomarkers and Risk of Venous Thromboembolism in Cancer Patients: A Systematic Review and Meta-Analysis

BACKGROUND

 Cancer patients have an increased risk of venous thromboembolism (VTE). Currently, the availability of highly discriminatory prediction models for VTE in cancer patients is limited. The implementation of biomarkers in prediction models might lead to refined VTE risk prediction. In this systematic review and meta-analysis, we aimed to evaluate candidate biomarkers and their association with cancer-associated VTE.

METHODS

 We searched Medline, EMBASE, and Cochrane Central for studies that evaluated biomarkers in adult cancer patients from inception to September 2022. We included studies reporting on VTE after a cancer diagnosis with biomarker measurements performed at a defined time point. Median/mean differences (for continuous measures) and odds ratios (for dichotomous measures) with 95% confidence intervals were estimated and pooled using random-effects models.

RESULTS

 We included 113 studies in the systematic review. Of these, 50 studies were included in the meta-analysis. We identified two biomarkers at cancer diagnosis (factor VIII and time to peak thrombin), three biomarkers pre-chemotherapy (D-dimer, fibrinogen, and mean platelet volume), and one biomarker preoperatively (platelet count) that had significant median or mean differences. Additionally, we found that hemoglobin <100 g/L and white blood count >11 × 109/L were significantly associated with future VTE risk only when measured at cancer diagnosis. Pre-chemotherapy neutrophil-to-lymphocyte ratio ≥3 and preoperative platelet count ≥400 × 109/L were also found to be associated with future VTE risk.

CONCLUSION

 In conclusion, this study identified nine candidate blood biomarkers that may help in optimizing VTE prediction in cancer patients that should be further explored in future studies.

Circulating Cytokines and Venous Thromboembolism: A Bidirectional Two-Sample Mendelian Randomization Study

BACKGROUND

 Epidemiological evidence has linked circulating cytokines to venous thromboembolism (VTE). However, it remains uncertain whether these associations are causal due to confounding factors or reverse causality. We aim to explore the causality between circulating cytokines and VTE, encompassing deep vein thrombosis (DVT) and pulmonary embolism (PE).

METHODS

 In the current bidirectional Mendelian randomization (MR) study, instrumental variables of 41 circulating cytokines were obtained from the genome-wide association study meta-analyses (8,293 individuals). Summary statistics for the association of VTE (17,048 cases and 325,451 controls), DVT (8,077 cases and 295,014 controls), and PE (8,170 cases and 333,487 controls) were extracted from the FinnGen Study. A multivariable MR study was conducted to adjust for potential confounders. The inverse-variance weighted method was employed as the main analysis, and comprehensive sensitivity analyses were conducted in the supplementary analyses.

RESULTS

 The MR analysis indicated stromal cell-derived factor-1α was suggestively associated with a reduced risk of VTE (odds ratio [OR]: 0.90; 95% confidence interval [CI]: 0.81-0.99; p = 0.033) and DVT (OR: 0.85; 95% CI: 0.75-0.97; p = 0.015). In addition, suggestive association of granulocyte colony-stimulating factor with PE (OR: 1.20; 95% CI: 1.06-1.37; p = 0.005) was observed. Multivariable MR analysis showed that the effect of cytokines on VTE was partly mediated through hemoglobin A1c and systolic blood pressure. Reverse MR analysis revealed that VTE was linked to decreased levels of several cytokines.

CONCLUSION

 We provide suggestive genetic evidence supporting the bidirectional causal effect between circulating cytokines and VTE, highlighting the importance of targeting circulating cytokines to reduce the incidence of VTE.

High microRNA-145 plasma levels are associated with decreased risk of future incident venous thromboembolism: the HUNT study

ABSTRACT

MicroRNA-145 (miR-145) has been reported to downregulate the expression of tissue factor and factor XI in vitro and decrease venous thrombus formation in animal models. However, the association between miR-145 and risk of future venous thromboembolism (VTE) in the general population remains unknown. We investigated the association between plasma levels of miR-145 and risk of future VTE in a case-cohort study. Incident VTE cases (n = 510) and a subcohort (n = 1890) were derived from the third survey of the Trøndelag Health Study (HUNT3), a population-based cohort. The expression levels of miR-145 were measured in plasma samples obtained at baseline. The study population was divided into quartiles based on miR-145 levels in participants in the subcohort, and weighted Cox regression was used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs). Plasma levels of miR-145 were inversely associated with VTE risk. Participants with miR-145 levels in the highest quartile had a 49% lower risk of VTE (HR, 0.51; 95% CI, 0.38-0.68) than those with miR-145 in the lowest quartile in age- and sex-adjusted analysis, and the inverse association was most pronounced for unprovoked VTE (HR, 0.39; 95% CI, 0.25-0.61). Risk estimates remained virtually the same after further adjustment for body mass index, and cancer and arterial cardiovascular disease at baseline. In conclusion, elevated expression levels of miR-145 in plasma were associated with decreased risk of future incident VTE. The protective role of miR-145 against VTE is consistent with previous experimental data and suggests that miR-145 has the potential to be a target for VTE prevention.

RNA methylation patterns, immune characteristics, and autophagy-related mechanisms mediated by N6-methyladenosine (m6A) regulatory factors in venous thromboembolism

Recent studies have found a link between deep vein thrombosis and inflammatory reactions. N6-methyladenosine (m6A), a crucial element in immunological regulation, is believed to contribute to the pathophysiology of venous thromboembolism (VTE). However, how the m6A-modified immune microenvironment is involved in VTE remains unclear. In the present study, we identified a relationship between VTE and the expression of several m6A regulatory elements by analyzing peripheral blood samples from 177 patients with VTE and 88 healthy controls from public GEO databases GSE19151 and GSE48000. We used machine learning to identify essential genes and constructed a diagnostic model for VTE using multivariate logistic regression. Unsupervised cluster analysis revealed a marked difference between m6A modification patterns in terms of immune cell infiltration, inflammatory reactivity, and autophagy. We identified two m6A-related autophagy genes (i.e., CHMP2B and SIRT1) and the crucial m6A regulator YTHDF3 using bioinformatics. We also examined two potential mechanisms through which YTHDF3 may affect VTE. m6A modification, immunity, and autophagy are closely linked in VTE, offering novel mechanistic and therapeutic insights.

Risk of Venous Thromboembolism by Cancer Type: A Network Meta-Analysis

Patients with cancer have an increased risk of venous thromboembolism (VTE). Comparing tumor-specific VTE risk is complicated by factors such as surgery, disease stage, and chemotherapy. Network meta-analysis (NMA) using cancer types as network nodes enabled us to estimate VTE rates by leveraging comparisons across cancer types while adjusting for baseline VTE risk in individual studies. This study was conducted to estimate the risk of VTE by cancer type and factors influencing VTE risk. The Embase, MEDLINE, and Cochrane Library repositories were systematically searched to identify clinical trials and observational studies published from 2005 to 2022 that assessed the risk of primary cancer-related VTE among two or more distinct cancer types. Studies with similar cancer populations and study methods reporting VTE occurring within 1 year of diagnosis were included in the NMA. Relative VTE rates across cancer types were estimated with random-effects Bayesian NMAs. Absolute VTE rates were calculated from these estimates using the average VTE incidence in lung cancer (the most frequently reported type) as the "anchor." From 2,603 records reviewed, 30 studies were included in this NMA. The general network described 3,948,752 patients and 18 cancer types: 3.1% experienced VTE within 1 year of diagnosis, with cancer-specific rates ranging from 0.7 to 7.4%. Consistent with existing VTE risk prediction tools, pancreatic cancer was associated with higher-than-average VTE risk. Other cancer types with high VTE risk were brain and ovarian cancers. The relative rankings of VTE risk for certain cancers changed based on disease stage and/or receipt of chemotherapy or surgery.

Inherited thrombophilia gene mutations and risk of venous thromboembolism in patients with cancer: A systematic review and meta-analysis

In the general population, individuals with an inherited thrombophilia have a higher risk of thrombosis, but the effect of inherited thrombophilia on the risk of cancer-associated venous thromboembolism (VTE) remains controversial. Our objective was to determine the risk of VTE in cancer patients with inherited thrombophilia. We conducted a systematic review and meta-analysis of studies reporting on VTE after a cancer diagnosis in adult patients who were tested for inherited thrombophilia. In September 2022, we searched Medline, EMBASE, and Cochrane Central. Two reviewers screened the abstracts/full texts and assessed study quality using the Quality in Prognostic Studies tool. We used Mantel-Haenszel random-effects models to estimate pooled odds ratios (OR) of VTE and 95% confidence intervals (95%CI). We included 37 and 28 studies in the systematic review and meta-analysis, respectively. Most studies focused on specific cancer types and hematologic malignancies were rare. The risk of VTE was significantly higher in cancer patients with non-O (compared with O) blood types (OR: 1.56 [95% CI: 1.28-1.90]), Factor V Leiden, and Prothrombin Factor II G20210A mutations compared with wild types (OR: 2.28 [95% CI: 1.51-3.48] and 2.14 [95% CI: 1.14-4.03], respectively). Additionally, heterozygous and homozygous methylenetetrahydrofolate reductase C677T had ORs of 1.50 (95% CI: 1.00-2.24) and 1.38 (95% CI: 0.87-2.22), respectively. Among those with Plasminogen-Activator Inhibitor-1 4G/5G, Vascular Endothelial Growth Factor (VEGF) A C634G, and VEGF C2578A mutations, there was no significant association with VTE. In conclusion, this meta-analysis provided evidence that non-O blood types, Factor V Leiden, and Prothrombin Factor II G20210A mutations are important genetic risk factors for VTE in cancer patients.

Effects of gender affirming hormone therapy with testosterone on coagulation and hematological parameters in transgender people assigned female at birth: A systematic review and meta-analysis

BACKGROUND

Hormone replacement therapy is associated with an increased thromboembolic risk. The effects of testosterone (T) on coagulation markers in people assigned female at birth (AFAB) under gender affirming hormone therapy (GAHT) are not well described.

METHODS

Systematic review and meta-analysis on English-language articles retrieved from PubMed, Scopus and Cochrane Library up to April 2023 investigating T therapy in AFAB people. Coagulation parameters included international normalized ratio (INR), fibrinogen, activated partial thromboplastin clotting time (aPTT), plasminogen activator inhibitor-1 (PAI-1); hematological variables included hemoglobin (Hb) and hematocrit (HCT). We also reported the rate of thromboembolic events. Data were combined as mean differences (MD) with a 95 % confidence interval (CI) of pre- vs post-follow-up values, using random-effects models.

RESULTS

We included 7 studies (6 prospective and 1 retrospective) providing information on 312 subjects (mean age: 23 to 30 years) who underwent GAHT with variable T preparation. T therapy was associated with a significant increase in INR values [MD: 0.02, 95 % confidence interval (CI): 0.01-0.03; p = 0.0001], with negligible heterogeneity (I2 = 4 %). T therapy was associated with increased Hb (MD: 1.48 g/dL, 95%CI: 1.17 to 1.78; I2 = 9 %) and HCT (4.39 %, 95%CI: 3.52 to 5.26; I2 = 23 %) values. No effect on fibrinogen, aPTT and PAI-1 was found. None of the study reported thromboembolic events during the follow-up.

CONCLUSION

Therapy with T increased blood viscosity in AFAB men. A slight increase in INR values was also found, but the clinical relevance and mechanism(s) of this finding needs to be clarified.

Causes of death after first time venous thromboembolism

BACKGROUND

Causes of death after first time community-acquired venous thromboembolism (VTE) diagnosed in unselected patients at the emergency department (ED) was investigated.

MATERIALS AND METHODS

The study consists of all patients > 18 years of age who had a visit for any medical reason to any of 5 different ED in Stockholm County, Sweden from 1st January 2016 to 31st December 2017. We have identified all patients with a first registered incident VTE; deep vein thrombosis (DVT) and/or pulmonary embolism (PE) during the study period. Cox regression models were used to estimate hazards ratios (HR) with 95% confidence intervals (CIs) for all-cause mortality and cause-specific death in patients with DVT or PE using all other patients as the reference group.

RESULTS

In total, 359,884 patients had an ED visit during the study period of whom about 2.1% were diagnosed with VTE (DVT = 4,384, PE = 3,212). The patients with VTE were older compared to the control group. During a mean follow up of 2.1 years, 1567 (21%) and 23,741(6.7%) patients died within the VTE and reference group, respectively. The adjusted risk of all-cause mortality was nearly double in patients with DVT (HR 1.7; 95% CI, 1.5-1.8) and more than 3-fold in patients with PE (HR 3.4; 95% CI, 3.1-3.6). While the risk of cancer related death was nearly 3-fold in patient with DVT (HR 2.7; 95% CI, 2.4-3.1), and 5-fold in PE (HR 5.4; 95% CI, 4.9-6.0 respectively). The diagnosis of PE during the ED visit was associated with a significantly higher risk of cardiovascular death (HR 2.2; 95% CI, 1.9-2.6).

CONCLUSION

Patients with VTE have an elevated risk of all-cause mortality, including cardiovascular death.

Factors Associated with Hospital Length of Stay among VTE Cases: Insights from the i-RegVed Registry

INTRODUCTION

Venous thromboembolism (VTE) is a multifactorial condition and one of the leading causes of mortality and disability. The present study explores the factors associated with hospitalization duration among different types of venous thromboembolism diagnoses, such as deep vein thrombosis (DVT), pulmonary embolism (PE), and other forms of thrombosis.

METHODS

The data included participants with VTE admitted to 13 hospitals within pan-India from June 2022 to December 2023 to the i-RegVed registry, where socio-demographic data, clinical history, and various factors associated with hospital length of stay (LOS) were included for analyses. Multilinear regression was performed to explore the factors associated with hospital LOS among VTE conditions such as DVT, PE, forms of thrombosis other than PE and DVT, and all VTE diagnoses.

RESULTS

A total of 633 participants were included in the study, with 55% being males, and 28.9% being homemakers. Longer hospital LOS was significantly associated with age (β = -.09, P < .05), sex (β = 3.21, P < .05), and non-communicable diseases (β = 3.51, P < .05) among participants with DVT and among participants with at least one of the VTE diagnoses, age (β = -.12, P < .001) and anticoagulant use (β = -2.49, P < .05) was significantly associated.

CONCLUSION

The findings provide insights into the factors influencing hospital outcomes among participants with different types of VTE, highlighting the importance of age and comorbidities in predicting the hospital LOS.

Cancer-associated thrombosis: What about microRNAs targeting the tissue factor coagulation pathway?

Cancer patients are often diagnosed with venous thromboembolism (VTE), a cardiovascular disease that substantially decreases their quality of life and survival rate. Haemostasis in these patients is deregulated, which is reflected in the common presentation of a blood hypercoagulation state. Despite the inconsistent results, existing evidence suggests that the expression of microRNAs (miRNAs) is deregulated in the context of venous thrombogenesis in the general population. However, few miRNAs are known to be linked to cancer-associated VTE due to the lack of studies with oncological patients. Parallelly, coagulation factor III, also known as tissue factor (TF), tissue factor pathway inhibitor 1 (TFPI1) and tissue factor pathway inhibitor 2 (TFPI2) have been proposed to have a central role in cancer-associated VTE and tumour progression. Yet, contrary to what was expected, the role of miRNAs targeting the TF coagulation pathway (or extrinsic coagulation pathway) is poorly explored in cancer-induced thrombogenesis. In this review, in addition to miRNAs implicated in VTE, TF and TFPI1/2-targeting miRNAs were revised. Future studies should clarify the implications of these non-coding RNAs in tumour coagulome.

Venous thromboembolism mortality and trends in older US adults, 2011-2019

Venous thromboembolism (VTE) affects 1.2 million people per year in the United States. With several clinical changes in diagnosis and treatment approaches in the past decade, we evaluated contemporary post-VTE mortality risk profiles and trends. Incident VTE cases were identified from the 2011-2019 Medicare 20% Sample, which is representative of nearly all Americans aged 65 and older. The social deprivation index was linked from public data; race/ethnicity and sex were self-reported. The all-cause mortality risk 30 days and 1 year after incident VTE was calculated in demographic subgroups and by prevalent cancer diagnosis status using model-based standardization. Risks for major cancer types, risk differences by age, sex, race/ethnicity, and socio-economic status (SES), and trends over time are also reported. The all-cause mortality risk among older US adults following incident VTE was 3.1% (95% CI 3.0-3.2) at 30 days and 19.6% (95% CI 19.2-20.1) at 1 year. For cancer-related VTE events, the age-sex-race-standardized risk was 6.0% at 30 days and 34.7% at 1 year. The standardized 30-day and 1-year risks were higher among non-White beneficiaries and among those with low SES. One-year mortality risk decreased 0.28 percentage points per year (95% CI 0.16-0.40) on average across the study period, with no trend observed for 30-day mortality risk. In sum, all-cause mortality risk following incident VTE has decreased slightly in the last decade, but racial and socio-economic disparities persist. Understanding patterns of mortality among demographic subgroups and in cancer-associated events is important for targeting efforts to improve VTE management.

Development and validation of a facile rapid assessment scale for perinatal venous thromboembolism in puerperium in Chinese women

BACKGROUND

It is still urgent and challenge to develop a simple risk assessment scale for venous thromboembolism (VTE) in puerperium in Chinese women.

METHODS

The study, a retrospective case-control study, was conducted in 12 hospitals in different cities in China. A total of 1152 pregnant women were selected, including 384 cases with VTE and 768 cases without VTE. A logistic regression method was conducted to determine the risk factors of VTE.

RESULTS

Age, BMI before delivery, gestational diabetes mellitus, family history (thrombosis, diabetes, cardiovascular disease), and assisted reproductive technology were independent risk factors (P<0.05). The difference between the high-risk group and the low-risk group was statistically significant(P<0.001) with a sensitivity of 0.578, specificity of 0.756, Yuden index o.334, and area under the ROC curve of 0.878.

CONCLUSIONS

The age (≥ 35 years), BMI before delivery (≥ 30 kg/m2), gestational diabetes mellitus, family history of related diseases and assisted reproductive technology are more likely to cause VTE after full-time delivery. The simple and rapid assessment scale of VTE in women after full-term delivery has perfect discrimination (P < 0.001), which can be applied to predict the risk of VTE in Chinese full-term postpartum women.

Hand grip strength in venous thromboembolism: risk of recurrence and mortality

Background

There is limited information on the relationship between muscle strength and recurrence and mortality after incident venous thromboembolism (VTE).

Objectives

To investigate whether weak hand grip strength (HGS) was associated with risk of recurrence and mortality in patients with VTE recruited from the general population.

Methods

Participants from the Tromsø Study with a first-time VTE (n = 545) were included, and all VTE recurrences and deaths among the participants were recorded in the period 1994 to 2020. Weak HGS was defined as lowest 25th percentile of the general population, and incidence rates for VTE recurrence and mortality according to weak vs normal (>25th percentile) HGS, with 95% CIs, were estimated.

Results

There were 90 recurrences and 350 deaths during a median of 3.7 years of follow-up. The fully adjusted hazard ratio (HR) for overall VTE recurrence for those with weak HGS vs those with normal HGS was 2.02 (95% CI, 1.23-3.30). The corresponding HRs for recurrence were 2.22 (95% CI, 1.18-4.17) in patients with a first deep vein thrombosis and 1.60 (95% CI, 0.72-3.57) in patients with a first pulmonary embolism. The cumulative 1-year survival was 74.9% and 77.8% in those with weak and normal HGS, respectively. For overall mortality after incident VTE, the fully adjusted HR for those with weak HGS was 1.34 (95% CI, 1.04-1.72).

Conclusion

Weak HGS was associated with an increased risk of recurrent VTE, and the association appeared to be particularly pronounced after incident deep vein thrombosis. There was a slightly lower survival probability among those with weak HGS than among those with normal HGS.

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.

Predicting the Safety and Effectiveness of Inferior Vena Cava Filters (PRESERVE): Outcomes at 12 months

OBJECTIVE

To determine the safety and effectiveness of vena cava filters (VCFs).

METHODS

A total of 1429 participants (62.7 ± 14.7 years old; 762 [53.3% male]) consented to enroll in this prospective, nonrandomized study at 54 sites in the United States between October 10, 2015, and March 31, 2019. They were evaluated at baseline and at 3, 6, 12, 18, and 24 months following VCF implantation. Participants whose VCFs were removed were followed for 1 month after retrieval. Follow-up was performed at 3, 12, and 24 months. Predetermined composite primary safety (freedom from perioperative serious adverse events [AEs] and from clinically significant perforation, VCF embolization, caval thrombotic occlusion, and/or new deep vein thrombosis [DVT] within 12-months) and effectiveness (composite comprising procedural and technical success and freedom from new symptomatic pulmonary embolism [PE] confirmed by imaging at 12-months in situ or 1 month postretrieval) end points were assessed.

RESULTS

VCFs were implanted in 1421 patients. Of these, 1019 (71.7%) had current DVT and/or PE. Anticoagulation therapy was contraindicated or had failed in 1159 (81.6%). One hundred twenty-six (8.9%) VCFs were prophylactic. Mean and median follow-up for the entire population and for those whose VCFs were not removed was 243.5 ± 243.3 days and 138 days and 332.6 ± 290 days and 235 days, respectively. VCFs were removed from 632 (44.5%) patients at a mean of 101.5 ± 72.2 days and median 86.3 days following implantation. The primary safety end point and primary effectiveness end point were both achieved. Procedural AEs were uncommon and usually minor, but one patient died during attempted VCF removal. Excluding strut perforation greater than 5 mm, which was demonstrated on 31 of 201 (15.4%) patients' computed tomography scans available to the core laboratory, and of which only 3 (0.2%) were deemed clinically significant by the site investigators, VCF-related AEs were rare (7 of 1421, 0.5%). Postfilter, venous thromboembolic events (none fatal) occurred in 93 patients (6.5%), including DVT (80 events in 74 patients [5.2%]), PE (23 events in 23 patients [1.6%]), and/or caval thrombotic occlusions (15 events in 15 patients [1.1%]). No PE occurred in patients following prophylactic placement.

CONCLUSIONS

Implantation of VCFs in patients with venous thromboembolism was associated with few AEs and with a low incidence of clinically significant PEs.

Predicting the Safety and Effectiveness of Inferior Vena Cava Filters (PRESERVE): Outcomes at 12 months

OBJECTIVE

To determine the safety and effectiveness of vena cava filters (VCFs).

METHODS

A total of 1429 participants (62.7 ± 14.7 years old; 762 [53.3% male]) consented to enroll in this prospective, nonrandomized study at 54 sites in the United States between October 10, 2015, and March 31, 2019. They were evaluated at baseline and at 3, 6, 12, 18, and 24 months following VCF implantation. Participants whose VCFs were removed were followed for 1 month after retrieval. Follow-up was performed at 3, 12, and 24 months. Predetermined composite primary safety (freedom from perioperative serious adverse events [AEs] and from clinically significant perforation, VCF embolization, caval thrombotic occlusion, and/or new deep vein thrombosis [DVT] within 12-months) and effectiveness (composite comprising procedural and technical success and freedom from new symptomatic pulmonary embolism [PE] confirmed by imaging at 12-months in situ or 1 month postretrieval) end points were assessed.

RESULTS

VCFs were implanted in 1421 patients. Of these, 1019 (71.7%) had current DVT and/or PE. Anticoagulation therapy was contraindicated or had failed in 1159 (81.6%). One hundred twenty-six (8.9%) VCFs were prophylactic. Mean and median follow-up for the entire population and for those whose VCFs were not removed was 243.5 ± 243.3 days and 138 days and 332.6 ± 290 days and 235 days, respectively. VCFs were removed from 632 (44.5%) patients at a mean of 101.5 ± 72.2 days and median 86.3 days following implantation. The primary safety end point and primary effectiveness end point were both achieved. Procedural AEs were uncommon and usually minor, but one patient died during attempted VCF removal. Excluding strut perforation greater than 5 mm, which was demonstrated on 31 of 201 (15.4%) patients' computed tomography scans available to the core laboratory, and of which only 3 (0.2%) were deemed clinically significant by the site investigators, VCF-related AEs were rare (7 of 1421, 0.5%). Postfilter, venous thromboembolic events (none fatal) occurred in 93 patients (6.5%), including DVT (80 events in 74 patients [5.2%]), PE (23 events in 23 patients [1.6%]), and/or caval thrombotic occlusions (15 events in 15 patients [1.1%]). No PE occurred in patients following prophylactic placement.

CONCLUSIONS

Implantation of VCFs in patients with venous thromboembolism was associated with few AEs and with a low incidence of clinically significant PEs.

Causal relationship between moderate to vigorous physical activity and venous thromboembolism

Previous studies have shown conflicting results about the impact of moderate to vigorous physical activity on the risk of venous thromboembolism (VTE).  Using Mendelian randomization, we assessed whether moderate to vigorous physical activity causally affects VTE from genetic level. Genetic instruments associated with moderate to vigorous physical activity at the genome-wide significance level (P < 5×10^- 8) were selected from the UK Biobank. Summary-level data for VTE were obtained from the FinnGen consortium. Univariable and multivariable Mendelian randomization analyses were conducted. Genetically predicted moderate to vigorous physical activity had no effect on VTE [odds ratio (OR) = 1.08; 95% confidence interval (CI) 0.66-1.78; P = 0.75] under a multiplicative random-effects inverse-variance weighted model. MR-Egger (OR = 0.20; 95% CI 0.01-4.70; P = 0.33), weighted median (OR = 1.08; 95% CI 0.52-2.25; P = 0.84), simple mode (OR = 2.53; 95% CI 0.59-10.92; P = 0.23), weighted mode (OR = 2.21; 95% CI 0.50-9.74; P = 0.31), and multivariable Mendelian randomization (OR = 0.74; 95% CI 0.46-1.19; P = 0.22) also yielded no significant association. The overall estimate was not influenced by individual single nucleotide polymorphism. No evidence of heterogeneity or horizontal pleiotropy was observed. Therefore, moderate to vigorous physical activity had no causal association with VTE in the general population.

Incidence and Predictors of Recurrence and Mortality Following First Venous Thromboembolism Among the Saudi Population: Single-Center Cohort Study

Background

Little is written about recurrence and mortality rates after a first episode of venous thromboembolism (VTE) among Saudi population.

Aim

Determine incidence rates and assess predictors of recurrence and mortality following the first VTE event.

Patients and Methods

A total of 1124 patients aged ≥18 years with symptomatic VTE confirmed by imaging tests were evaluated. The incidence of VTE recurrence and mortality were assessed. The association between patient characteristics, and VTE recurrence and mortality was explored by estimating the hazard ratio (HR) and 95% confidence interval (CI). The difference between cancer-related, provoked and unprovoked VTE in terms of recurrence and mortality was explored using Kaplan–Meier curves.

Results

The annual incidence rate of the first VTE was 1.7 per 1000 patients. Of 1124 patients with first VTE, 214 (19%) developed recurrent VTE, and 192 (17%) died with overall incidence rates of 15.8 per 100 person-years (95% CI, 13.8–18.0) and 10.0 per 100 person-years (95% CI, 8.7–11.5). Intensive care unit (ICU) admission (HR, 2.15; 95% CI, 1.67–3.10), presence of active cancer (HR, 2.97; 95% CI, 1.87–3.95), immobilization (HR, 2.52; 95% CI, 1.79–3.67), infection (HR, 2.32; 95% CI, 1.94–3.45), and pulmonary embolism ± deep venous thrombosis (HR, 2.22; 95% CI, 1.56–3.16) were found to be independent predictors of recurrent VTE. Recurrence carries a high hazard of mortality (HR, 5.21; 95% CI, 3.61–7.51). The estimated median time to VTE recurrence was lower in cancer-related VTE (18.7 months) compared with provoked (29.0 months) and unprovoked VTE (28.4 months). The estimated survival median time was lower in cancer-related VTE (21.8 months) compared with provoked (30.5 months) and unprovoked VTE (29.8 months).

Conclusion

Immobilization and presence of active cancer, infection, and PE ± DVT were significant predictors of recurrent VTE. Patients who developed recurrent VTE had a 5.2-fold higher hazard of mortality compared with patients with no VTE recurrence.

The venous thrombosis registry in Østfold Hospital (TROLL registry) - design and cohort description

Purpose

The incidence of venous thromboembolism (VTE) is expected to increase over the next decades, further increasing its substantial impact on patients and health care resources. Registries have the benefit of reporting real-world data without excluding clinically important subgroups. Our aim was to describe a Norwegian VTE registry and to provide descriptive data on the population and management.

Registry Population

The Venous Thrombosis Registry in Østfold Hospital (TROLL) is an ongoing registry of consecutive patients diagnosed with, treated, and/or followed up for VTE at Østfold Hospital, Norway, since 2005. Baseline and follow-up data, including demographics, clinical features, risk factors, diagnostic procedures, classification of VTE, and treatment were collected during hospitalization, and at scheduled outpatient visits.

Findings to Date

From January 2005 to June 2021, 5037 patients were eligible for research in TROLL. Median age was 67 years (interquartile range, 55-77), and 2622 (52.1%) were male. Of these, 2736 (54.3%) had pulmonary embolism (PE), 2034 (40.4%) had deep vein thrombosis (DVT), and 265 (5.3%) had upper-extremity DVT or splanchnic or cerebral sinus vein thrombosis. In total, 2330 (46.3%) were classified as unprovoked VTE, and 1131 (22.5%) had cancer. Direct oral anticoagulants were the most frequent therapeutic agents (39.3%) followed by low-molecular-weight heparins (30.4%) and vitamin K antagonists (30.3%). Outpatient treatment for PE increased from 4% in 2005 to 23% in 2019.

Future Plans

TROLL is a population-based ongoing registry that represents a valuable source of real-world data that will be used for future research on the management and outcomes of VTE.

Incident thrombus location and predicting risk of recurrent venous thromboembolism

Background

Understanding venous thromboembolism (VTE) recurrence risk is central to determining the appropriate treatment course. Whether this risk varies after discontinuing anticoagulation or overall by type of incident event (pulmonary embolism [PE] vs deep vein thrombosis [DVT]) and by the detailed location of the DVT needs further clarification.

Methods

In this population-based inception cohort of incident VTE cases with follow-up by electronic health record review, incident DVT was categorized as distal, popliteal, or iliofemoral. We used the Fine-Gray regression model to describe the predictive association of the thrombus location with the risk of recurrence before death.

Results

Among 2766 participants with an incident event from 2002 to 2010, 1713 (62%) ceased anticoagulation and were followed for recurrent events; 301 events were observed during the 4.5 years of follow-up. Relative to participants with an incident thrombus in an iliofemoral location and no PE, those with a thrombus in a popliteal location and no PE had a similar risk of recurrence (adjusted subdistribution hazard ratio [aSHR], 0.82 [95% confidence interval (CI), 0.57-1.19]), while those with a thrombus in a distal location and no PE and those with a thrombus that included a PE had lower risk of recurrence: aSHR, 0.34 (95% CI, 0.20-0.57); and aSHR, 0.58 (95% CI 0.45-0.76), respectively.

Conclusions

The findings of this population-based inception cohort confirm that the risk of recurrent VTE after discontinuing anticoagulants is similar after iliofemoral and popliteal DVT but is lower after distal DVT. Recurrence may be lower after PE than proximal DVT.

The Interaction Effect between Comorbidity Burden and Venous Thromboembolism on Mortality: A Nationwide Cohort Study

BACKGROUND

Comorbidity influences venous thromboembolism (VTE) mortality, but it is unknown whether this is due to comorbidity alone or whether biological interaction exists.

OBJECTIVES

We examined whether comorbidity and VTE interact to increase VTE mortality beyond their individual effects.

METHODS

This nationwide population-based cohort study included all VTE patients ≥18 years during 2000 to 2016, and an age-, sex-, and comorbidity-matched comparison cohort of individuals without VTE. We computed age-standardized mortality rates and examined interaction on the additive scale using interaction contrasts (difference in rate differences).

RESULTS

After 30-day follow-up, the mortality rate per 1,000 person-years among individuals with no comorbidity was 419 (95% confidence interval [CI]: 391-447) in the VTE and 16 (95% CI: 13-18) in the comparison cohort (rate difference: 403). The corresponding mortality rate increased to 591 (95% CI: 539-643) in the VTE cohort and 38 (95% CI: 33-44) in the comparison cohort among individuals with low comorbidity (rate difference: 553). The interaction contrast (150) showed that 25% (150/591) of mortality was explained by the interaction in individuals with low comorbidity. This percentage increased to 56% for moderate and 63% for severe comorbidity. Interaction effects were largest within 30-day follow-up, for provoked VTE, in young individuals, and in individuals noncompliant to anticoagulant therapy. Dose-response patterns for interaction effects were also observed after 31-365-day and >1-5-year follow-up (p < 0.0001). Interaction effects varied between individual comorbidities.

CONCLUSION

Biological interaction between comorbidity and VTE explained a substantial proportion of VTE mortality. The interaction effect increased with comorbidity burden.

Risk stratification for predicting recurrent venous thromboembolism after discontinuation of anticoagulation: a post-hoc analysis of a French prospective multicenter study

BACKGROUND

We aimed to validate and to refine current recurrent venous thromboembolism (VTE) risk classification.

METHODS

We performed a post-hoc analysis of a multicentre cohort, including 1,881 patients with a first symptomatic VTE prospectively followed after anticoagulation discontinuation. The primary objective was to validate the International Society of Thrombosis and Haemostasis (ISTH) risk classification in predicting recurrence risk. Secondary objective was to evaluate a refined ISTH classification based on recurrence risk estimate for each individual risk factors.

RESULTS

During a 4.8-year median follow-up after anticoagulation discontinuation, symptomatic recurrent VTE occurred in 230 patients (12.2%). Based on ISTH classification, patients with unprovoked VTE or VTE with minor or major persistent risk factor had a 2-fold increased recurrence risk as compared to those with VTE and major transient risk factor. Recurrence risk was not increased in patients with minor transient factor (Hazard Ratio[HR] 1.31;95%CI0.84-2.06). Individual risk factors analysis identified hormone-related VTE (pregnancy: HR 0.26; 95%CI0.08-0.82; estrogens: HR 0.25; 95%CI0.14-0.47) and amyotrophic lateral sclerosis (HR 5.84; 95%CI1.82-18.70). After reclassification of these factors as major transient for the former and major persistent for the latter, refined ISTH classification allowed to accurately discriminate between patients at low-risk (i.e., with major transient risk factor) and those at high-risk of recurrence (i.e., without major transient risk factors).

CONCLUSIONS

Among patients who stopped anticoagulation after a first VTE, a refined ISTH classification based on recurrence risk intensity of individual factors allowed to discriminate between patients at low-recurrence risk, including hormonal exposure in women, and patients at high-recurrence risk.

Low Mean Platelet Volume is Associated with Deep Vein Thrombosis in Older Patients with Hip Fracture

This study aimed to explore the association between mean platelet volume (MPV) and preoperative deep vein thrombosis (DVT) in older patients with hip fracture. A total of 352 consecutive older patients with hip fracture were included from January 2014 to December 2020. MPV values were measured on admission, and color Doppler ultrasonography was performed for DVT screening before the planned surgery. The receiver operating characteristic (ROC) curve was used to establish the optimal cut-off value for the prediction of DVT. Univariate and multivariate logistic regression analysis were used to examine the association between factors and DVT. The overall prevalence of preoperative DVT was 15.1%, and patients with DVT had a lower value of MPV than non-DVT patients (11.6 ± 1.2 fL vs 12.3 ± 1.4 fL, P < .01). The cut-off point according to the ROC curve for MPV was 13.3 fL, and multivariate logistic regression analysis showed that MPV level < 13.3 fL was significantly associated with an increased risk of DVT (OR = 4.857, 95% CI: 1.091-21.617, P = .038), and with every 1.0 fL decrease in MPV, the risk increased by 27.7% (OR = 1.277, 95% CI: 1.001-1.629, P = .047). Our findings indicate that a low MPV level is associated with DVT in older patients with hip fracture. As MPV is a simple indicator that can be calculated from the blood routine test, it may be a potential biomarker of DVT with the combination of other tests, further studies are needed to confirm these results.

Identification of four hub genes in venous thromboembolism via weighted gene coexpression network analysis

Background

The pathogenic mechanisms of venous thromboembolism (VT) remain to be defined. This study aimed to identify differentially expressed genes (DEGs) that could serve as potential therapeutic targets for VT.

Methods

Two human datasets (GSE19151 and GSE48000) were analyzed by the robust rank aggregation method. Gene ontology and Kyoto encyclopedia of genes and genomes pathway enrichment analyses were conducted for the DEGs. To explore potential correlations between gene sets and clinical features and to identify hub genes, we utilized weighted gene coexpression network analysis (WGCNA) to build gene coexpression networks incorporating the DEGs. Then, the levels of the hub genes were analyzed in the GSE datasets. Based on the expression of the hub genes, the possible pathways were explored by gene set enrichment analysis and gene set variation analysis. Finally, the diagnostic value of the hub genes was assessed by receiver operating characteristic (ROC) analysis in the GEO database.

Results

In this study, we identified 54 upregulated and 10 downregulated genes that overlapped between normal and VT samples. After performing WGCNA, the magenta module was the module with the strongest negative correlation with the clinical characteristics. From the key module, FECH, GYPA, RPIA and XK were chosen for further validation. We found that these genes were upregulated in VT samples, and high expression levels were related to recurrent VT. Additionally, the four hub genes might be highly correlated with ribosomal and metabolic pathways. The ROC curves suggested a diagnostic value of the four genes for VT.

Conclusions

These results indicated that FECH, GYPA, RPIA and XK could be used as promising biomarkers for the prognosis and prediction of VT.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02409-4.

Downregulation of microRNA-200c-3p alleviates the aggravation of venous thromboembolism by targeting serpin family C member 1

Venous thromboembolism (VTE) is the third most prevalent cardiovascular complication. Increasing studies have demonstrated that some microRNAs (miRNAs) are aberrantly expressed in VTE and play crucial roles in mediating the development of VTE. Therefore, our study intends to explore the detailed function and molecular mechanism of miR-200c-3p in VTE progression. In our research, VTE rat models were first established via inferior vena cava (IVC) ligation and the time-dependent effects of IVC ligation on thrombus formation were discovered. The results of reverse transcription quantitative polymerase-chain reaction (RT-qPCR) and western blotting showed that serpin family C member 1 (SERPINC1) was downregulated in VTE rat models and showed an inverse correlation with thrombus load. MiRNA target prediction tools and luciferase reporter assay confirmed SERPINC1 as a target for miR-200c-3p. VTE rats were injected with miR-200c-3p inhibitor for 24 h to investigate whether miR-200c-3p knockdown influences thrombus formation in vivo. Histological examination through hematoxylin-eosin staining revealed that miR-200c-3p downregulation markedly inhibited the formation of thrombus in IVC of rats. Additionally, miR-200c-3p was upregulated while SERPINC1 was downregulated in serum and inferior vena cava of VTE rats as well as in plasma of patients with VTE. Linear regression analysis demonstrated that miR-200c-3p expression was negatively correlated to SERPINC1 expression in VTE rats and patients with VTE. Our study determines the previously unelucidated function of miR-200c-3p in VTE, which might provide a potential novel insight for the treatment of VTE.

Plasma procoagulant phospholipid clotting time and venous thromboembolism risk

BACKGROUND

Negatively charged procoagulant phospholipids, phosphatidylserine (PS) in particular, are vital to coagulation and expressed on the surface membrane of extracellular vesicles. No previous study has investigated the association between plasma procoagulant phospholipid clotting time (PPLCT) and future risk of venous thromboembolism (VTE).

OBJECTIVES

To investigate the association between plasma PPLCT and the risk of incident VTE in a nested case-control study.

METHODS

We conducted a nested case-control study in 296 VTE patients and 674 age- and sex-matched controls derived from a general population cohort (The Tromsø Study 1994-2007). PPLCT was measured in platelet-free plasma using a modified factor Xa-dependent clotting assay. Logistic regression was used to estimate odds ratio (OR) with 95% confidence intervals (CI) for VTE with PPLCT modelled as a continuous variable across quartiles and in dichotomized analyses.

RESULTS

There was a weak inverse association between plasma PPLCT and risk of VTE per 1 standard deviation increase of PPLCT (OR 0.93, 95% CI 0.80-1.07) and when comparing those with PPLCT in the highest quartile (OR 0.89, 95% CI 0.60-1.30) with those in the lowest quartile. Subjects with PPLCT >95th percentile had substantially lowered OR for VTE (OR 0.35, 95% CI 0.13-0.81). The inverse association was stronger when the analyses were restricted to samples taken shortly before the event. The risk estimates by categories of plasma PPLCT were similar for deep vein thrombosis and pulmonary embolism.

CONCLUSION

Our findings suggest that high plasma PPLCT is associated with reduced risk of VTE.

Pulmonary embolism and deep vein thrombosis: Similar but different

INTRODUCTION

Pulmonary embolism (PE) and deep vein thrombosis (DVT), the two clinical manifestations of venous thromboembolism (VTE), constitute a major global burden of cardiovascular disease. They are often referred to as one disease but several patient characteristics, risk factors, real-world treatment, and clinical outcomes may differ substantially between PE and DVT alone.

MATERIALS AND METHODS

We conducted a narrative review of the state-of-the-art literature on the topic of PE and DVT alone using PubMed, Google scholar, and MEDLINE databases and the most established international consensus statement guidelines for the management of VTE, focusing on the recommendations for diagnosis and treatment but also including epidemiological and clinical characteristics of VTE, highlighting similarities and differences between PE and DVT alone.

RESULTS

Several patient characteristics, risk factors, clinical manifestations, and outcomes differ substantially between PE versus DVT alone. Nevertheless, recommendations for both diagnosis and treatment are strikingly similar in the current guidelines for the management of DVT and PE, except for the indication for advanced reperfusion therapies.

CONCLUSIONS

The differences in risk factors, clinical manifestations, and clinical outcomes between patients with PE versus DVT alone are only marginally addressed in the current consensus guidelines. More data is needed allowing proposal of evidence-based adjustments in the diagnostic and therapeutic strategies for these two manifestations of VTE. Tailored risk stratification and individualized management strategies for patients with PE and DVT alone may lead to a better prognosis, less recurrence and complications, and possibly to a gain of quality-adjusted life years in patients with VTE.

Elevated plasma concentration of complement factor C5 is associated with risk of future venous thromboembolism

The role of complement in the pathogenesis of venous thromboembolism (VTE) is unclear. We aimed to (i) investigate whether plasma complement component C5 levels are influenced by genetic variants or chronic inflammation, and (ii) investigate the association between plasma C5 and risk of future VTE in a nested case-control study with 415 VTE patients and 848 age- and sex-matched controls derived from the Tromsø study. Plasma C5 levels were measured at inclusion. Odds ratios (ORs) with 95% confidence intervals (95% CI) for provoked and unprovoked VTE across tertiles of C5 concentrations were estimated using logistic regression. C-reactive protein (CRP) was adjusted for as a proxy for general inflammation. Whole exome sequencing and protein quantitative trait loci analyses were performed to assess genetic influence on C5 concentrations. There was no association between genome-wide or C5-related gene variants and C5 levels. The association between plasma C5 levels and VTE risk displayed a threshold effect, where subjects with C5 levels above the lowest tertile had increased VTE risk. Subjects in tertile 3 (highest C5 levels) had an age and sex-adjusted OR of 1.45 (95% CI 1.07-1.96) compared to tertile 1 (lowest). This was more pronounced for unprovoked VTE (OR 1.70, 95% CI 1.11-2.60). Adjustments for body mass index and CRP had minor impact on risk estimates. The ORs increased substantially with shorter time between blood sampling and VTE event. In conclusion, plasma C5 was associated with risk of future VTE. C5 levels were not genetically regulated and only slightly influenced by chronic inflammation.

Which patients are at high risk of recurrent venous thromboembolism (deep vein thrombosis and pulmonary embolism)?

Recurrent venous thromboembolism (VTE, or deep vein thrombosis and pulmonary embolism) is associated with mortality and long-term morbidity. The circumstances in which an index VTE event occurred are crucial when personalized VTE recurrence risk is assessed. Patients who experience a VTE event in the setting of a transient major risk factor (such as surgery associated with general anesthesia for >30 minutes) are predicted to have a low VTE recurrence risk following discontinuation of anticoagulation, and limited-duration anticoagulation is generally recommended. In contrast, those patients whose VTE event occurred in the absence of risk factors or who have persistent risk factors have a higher VTE recurrence risk. Here, we review the literature surrounding VTE recurrence risk in a range of clinical conditions. We describe gender-specific risks, including VTE recurrence risk following hormone- and pregnancy-associated VTE events. Finally, we discuss how the competing impacts of VTE recurrence and bleeding have shaped international guideline recommendations.

Plasma levels of von Willebrand factor and future risk of incident venous thromboembolism

Several case-control studies have reported elevated plasma von Willebrand factor (VWF) levels in patients with venous thromboembolism (VTE) compared with controls. However, because few studies have investigated the association in a prospective design, it is unclear whether elevated plasma VWF is a risk factor or a consequence of the VTE event. Therefore, we aimed to investigate the prospective association between plasma VWF levels and risk of VTE, as well as to perform subgroup analyses of deep vein thrombosis (DVT) and pulmonary embolism. We established a population-based nested case-control study of 414 VTE cases and 843 age- and sex-matched controls based on the Tromsø study cohort (1994-2007). Blood samples were collected at cohort baseline (1994-1995). Odds ratios (ORs) with 95% confidence intervals (CIs) for VTE were estimated across quartiles of VWF levels. We found that the risk of VTE increased linearly across quartiles of VWF levels (P for trend = .023). Participants with VWF in the highest quartile had an OR of 1.45 (95% CI, 1.03-2.03) for VTE compared with those in the lowest quartile. The association was strongest for unprovoked VTE (OR, 2.74; 95% CI, 1.66-4.54) and unprovoked DVT in particular (OR, 6.73; 95% CI, 3.07-14.76). Further adjustment for body mass index, C-reactive protein, hypertension, estrogen use, and smoking had a modest effect on the risk estimates. To conclude, we found a dose-dependent relationship between plasma VWF levels and future risk of incident VTE, and unprovoked events in particular. Our findings suggest that VWF may represent a promising biomarker for future risk of incident VTE.

Which patients are at high risk of recurrent venous thromboembolism (deep vein thrombosis and pulmonary embolism)?

Recurrent venous thromboembolism (VTE, or deep vein thrombosis and pulmonary embolism) is associated with mortality and long-term morbidity. The circumstances in which an index VTE event occurred are crucial when personalized VTE recurrence risk is assessed. Patients who experience a VTE event in the setting of a transient major risk factor (such as surgery associated with general anesthesia for >30 minutes) are predicted to have a low VTE recurrence risk following discontinuation of anticoagulation, and limited-duration anticoagulation is generally recommended. In contrast, those patients whose VTE event occurred in the absence of risk factors or who have persistent risk factors have a higher VTE recurrence risk. Here, we review the literature surrounding VTE recurrence risk in a range of clinical conditions. We describe gender-specific risks, including VTE recurrence risk following hormone- and pregnancy-associated VTE events. Finally, we discuss how the competing impacts of VTE recurrence and bleeding have shaped international guideline recommendations.

Survival and quality of life after early discharge in low-risk pulmonary embolism

Introduction

Early discharge of patients with acute low-risk pulmonary embolism requires validation by prospective trials with clinical and quality-of-life outcomes.

Methods

The multinational Home Treatment of Patients with Low-Risk Pulmonary Embolism with the Oral Factor Xa Inhibitor Rivaroxaban (HoT-PE) single-arm management trial investigated early discharge followed by ambulatory treatment with rivaroxaban. The study was stopped for efficacy after the positive results of the predefined interim analysis at 50% of the planned population. The present analysis includes the entire trial population (576 patients). In addition to 3-month recurrence (primary outcome) and 1-year overall mortality, we analysed self-reported disease-specific (Pulmonary Embolism Quality of Life (PEmb-QoL) questionnaire) and generic (five-level five-dimension EuroQoL (EQ-5D-5L) scale) quality of life as well as treatment satisfaction (Anti-Clot Treatment Scale (ACTS)) after pulmonary embolism.

Results

The primary efficacy outcome occurred in three (0.5%, one-sided upper 95% CI 1.3%) patients. The 1-year mortality was 2.4%. The mean±sd PEmb-QoL decreased from 28.9±20.6% at 3 weeks to 19.9±15.4% at 3 months, a mean change (improvement) of −9.1% (p<0.0001). Improvement was consistent across all PEmb-QoL dimensions. The EQ-5D-5L was 0.89±0.12 at 3 weeks after enrolment and improved to 0.91±0.12 at 3 months (p<0.0001). Female sex and cardiopulmonary disease were associated with poorer disease-specific and generic quality of life; older age was associated with faster worsening of generic quality of life. The ACTS burden score improved from 40.5±6.6 points at 3 weeks to 42.5±5.9 points at 3 months (p<0.0001).

Conclusions

Our results further support early discharge and ambulatory oral anticoagulation for selected patients with low-risk pulmonary embolism. Targeted strategies may be necessary to further improve quality of life in specific patient subgroups.

Could venous thromboembolism and major bleeding be indicators of lung cancer mortality? A nationwide database study

Background

Venous thromboembolism (VTE) is highly prevalent in cancer patients and can cause severe morbidity. VTE treatment is essential, but anticoagulation increases the risk of major bleeding. The purpose was to evaluate the impact of VTE and major bleeding on survival and to identify significant risk factors for these events in lung cancer patients.

Methods

Data were extracted from a permanent sample of the French national health information system (including hospital and out-of-hospital care) from 2009 to 2016. All episodes of VTE and major bleeding events within one year after cancer diagnosis were identified. A Cox model was used to analyse the effect of VTE and major bleeding on the patients’ one-year survival. VTE and major bleeding risk factors were analysed with a Fine and Gray survival model.

Results

Among the 2553 included patients with lung cancer, 208 (8%) had a VTE episode in the year following diagnosis and 341 (13%) had major bleeding. Almost half of the patients died during follow-up. Fifty-six (60%) of the patients presenting with pulmonary embolism (PE) died, 48 (42%) of the patients presenting with deep vein thrombosis (DVT) alone died and 186 (55%) of those presenting with a major bleeding event died. The risk of death was significantly increased following PE and major bleeding events. VTE concomitant with cancer diagnosis was associated with an increased risk of VTE recurrence beyond 6 months after the first VTE event (sHR = 4.07 95% CI: 1.57–10.52). Most major bleeding events did not appear to be related to treatment.

Conclusion

VTE is frequent after a diagnosis of lung cancer, but so are major bleeding events. Both PE and major bleeding are associated with an increased risk of death and could be indicators of lung cancer mortality.

Role of microRNAs in Venous Thromboembolism

MicroRNAs (miRNAs) are non-coding RNAs that execute their function by targeted downregulation of gene expressions. There is growing evidence from epidemiological studies and animal models suggesting that the expression level of miRNAs is dysregulated in venous thromboembolism (VTE). In this review, we summarize the current knowledge on the role of miRNAs as biomarkers for VTE and provide general insight into research exploring the modulation of miRNA activity in animal models of venous thrombosis. Up to now, published studies have yielded inconsistent results on the role of miRNAs as biomarkers for VTE with most of the reports focused on diagnostic research. The limited statistical power of the individual studies, due to the small sample sizes, may substantially contribute to the poor reproducibility among studies. In animal models, over-expression or inhibition of some miRNAs appear to influence venous thrombus formation and resolution. However, there is an important gap in knowledge on the potential role of miRNAs as therapeutic targets in VTE. Future research involving large cohorts should be designed to clarify the clinical usefulness of miRNAs as biomarkers for VTE, and animal model studies should be pursued to unravel the role of miRNAs in the pathogenesis of VTE and their potential as therapeutic targets.

Resolution of Deep Venous Thrombosis: Proposed Immune Paradigms

Venous thromboembolism (VTE) is a pathology encompassing deep vein thrombosis (DVT) and pulmonary embolism (PE) associated with high morbidity and mortality. Because patients often present after a thrombus has already formed, the mechanisms that drive DVT resolution are being investigated in search of treatment. Herein, we review the current literature, including the molecular mechanisms of fibrinolysis and collagenolysis, as well as the critical cellular roles of macrophages, neutrophils, and endothelial cells. We propose two general models for the operation of the immune system in the context of venous thrombosis. In early thrombus resolution, neutrophil influx stabilizes the tissue through NETosis. Meanwhile, macrophages and intact neutrophils recognize the extracellular DNA by the TLR9 receptor and induce fibrosis, a complimentary stabilization method. At later stages of resolution, pro-inflammatory macrophages police the thrombus for pathogens, a role supported by both T-cells and mast cells. Once they verify sterility, these macrophages transform into their pro-resolving phenotype. Endothelial cells both coat the stabilized thrombus, a necessary early step, and can undergo an endothelial-mesenchymal transition, which impedes DVT resolution. Several of these interactions hold promise for future therapy.

Effect of Statins on Recurrent Venous Thromboembolism (from the COMMAND VTE Registry)

Statins, which are considered as essential for primary and secondary prevention of atherosclerotic diseases, were also reported to reduce first venous thromboembolism (VTE). However, the effect of statins on VTE recurrence remains conflicting. We aimed to examine the association between statin use and VTE recurrence in a large observational study in Japan. The COMMAND VTE Registry is a multicenter registry enrolling consecutive 3027 patients with acute symptomatic VTE in 29 centers in Japan between January 2010 and August 2014. In the current study, the entire cohort was divided into statin group (N = 437) and no-statin group (N = 2590) according to the status of statin use at baseline. The statin group as compared with the no-statin group was older (statin group 71.2 vs no-statin group 66.5 years, p <0.001), included more women (67% vs 60%, p = 0.008), and less frequently had active cancer (12% vs 25%, p <0.001). There was no significant difference in the clinical presentation of VTE (pulmonary embolism, 58% vs 56%, p = 0.44). The cumulative 3-year incidence of recurrent VTE was significantly lower in the statin group than the no-statin group (3.8% vs 8.8%, p <0.001). After adjusting for confounders including active cancer, statin use was associated with significantly lower risk for recurrent VTE (Hazard ratio 0.49, 95% confidence interval 0.29 to 0.78, p = 0.002). The results were consistent in a sensitivity sub-group analysis with and without active cancer. In conclusion, statin use was associated with significantly lower risk for the recurrent VTE in patients with VTE.

Cardiorespiratory fitness and future risk of venous thromboembolism

BACKGROUND

Cardiorespiratory fitness (CRF) is a strong predictor of future arterial cardiovascular disease and premature mortality. However, there are limited data on the association between CRF and the risk of incident venous thromboembolism (VTE).

OBJECTIVES

To investigate whether estimated CRF (eCRF) was associated with the risk of incident VTE in a cohort recruited from the general population.

METHODS

Participants (n = 10 393) from the sixth survey of the Tromsø Study (2007-08) were included, and incident VTEs were recorded up to 31 December 2016. CRF was estimated in sex-specific algorithms based on age, waist circumference, resting heart rate, and self-reported physical activity. Hazard ratios (HRs) with 95% confidence intervals (CIs) of VTE according to categories of eCRF were estimated in Cox regression models adjusted for sex with age as timescale. The impact of weight status was evaluated in analyses stratified by weight category.

RESULTS

There were 176 incident VTEs during follow-up. Compared with individuals with eCRF < 85% of age-predicted, those with eCRF of 85% to 100% and >100% of age-predicted had 46% (HR 0.54; 95% CI 0.39-0.77) and 67% (HR 0.33; 95% CI 0.20-0.54) lower VTE risk, respectively. Compared with overweight/obese individuals with eCRF < 85% of age-predicted, overweight/obese individuals with eCRF ≥ 85% had 50% (HR 0.50, 95% CI 0.35-0.74) lower risk, and normal weight individuals with eCRF ≥ 85% had 55% (HR 0.45, 95% CI 0.30-0.68) lower risk.

CONCLUSIONS

Higher eCRF was associated with lower risk of incident VTE. The association was independent of weight categories, suggesting that higher eCRF may modify the association between obesity and VTE.

Prediction of recurrent venous thrombosis in all patients with a first venous thrombotic event: The Leiden Thrombosis Recurrence Risk Prediction model (L-TRRiP)

BACKGROUND

Recurrent venous thromboembolism (VTE) is common. Current guidelines suggest that patients with unprovoked VTE should continue anticoagulants unless they have a high bleeding risk, whereas all others can stop. Prediction models may refine this dichotomous distinction, but existing models apply only to patients with unprovoked first thrombosis. We aimed to develop a prediction model for all patients with first VTE, either provoked or unprovoked.

METHODS AND FINDINGS

Data were used from two population-based cohorts of patients with first VTE from the Netherlands (Multiple Environment and Genetic Assessment of Risk Factors for Venous Thrombosis [MEGA] follow-up study, performed from 1994 to 2009; model derivation; n = 3,750) and from Norway (Tromsø study, performed from 1999 to 2016; model validation; n = 663). Four versions of a VTE prediction model were developed: model A (clinical, laboratory, and genetic variables), model B (clinical variables and fewer laboratory markers), model C (clinical and genetic factors), and model D (clinical variables only). The outcome measure was recurrent VTE. To determine the discriminatory power, Harrell's C-statistic was calculated. A prognostic score was assessed for each patient. Kaplan-Meier plots for the observed recurrence risks were created in quintiles of the prognostic scores. For each patient, the 2-year predicted recurrence risk was calculated. Models C and D were validated in the Tromsø study. During 19,201 person-years of follow-up (median duration 5.7 years) in the MEGA study, 507 recurrences occurred. Model A had the highest predictive capability, with a C-statistic of 0.73 (95% CI 0.71-0.76). The discriminative performance was somewhat lower in the other models, with C-statistics of 0.72 for model B, 0.70 for model C, and 0.69 for model D. Internal validation showed a minimal degree of optimism bias. Models C and D were externally validated, with C-statistics of 0.64 (95% CI 0.62-0.66) and 0.65 (95% CI 0.63-0.66), respectively. According to model C, in 2,592 patients with provoked first events, 367 (15%) patients had a predicted 2-year risk of >10%, whereas in 1,082 patients whose first event was unprovoked, 484 (45%) had a predicted 2-year risk of <10%. A limitation of both cohorts is that laboratory measurements were missing in a substantial proportion of patients, which therefore were imputed.

CONCLUSIONS

The prediction model we propose applies to patients with provoked or unprovoked first VTE-except for patients with (a history of) cancer-allows refined risk stratification, and is easily usable. For optimal individualized treatment, a management study in which bleeding risks are also taken into account is necessary.

Physical activity and risk of recurrence and mortality after incident venous thromboembolism

BACKGROUND

Limited data exist on the relationship between physical activity and major complications after incident venous thromboembolism (VTE).

OBJECTIVES

To investigate whether physical activity was associated with risk of recurrence and mortality in patients with VTE recruited from the general population.

METHODS

Patients with incident VTE (n = 786) derived from the Tromsø Study surveys 4-6 (1994-1995, 2001-2002, and 2007-2008) were included, and data on physical activity were dichotomized according to the activity level reported in the survey preceding the incident VTE (inactive: <1 hour per week, active: ≥1 hour per week). Recurrent VTE and all-cause mortality were registered up to December 31, 2015. Hazard ratios (HRs) for recurrence and all-cause mortality were calculated using Cox regression models with the inactive group as reference.

RESULTS

There were 139 recurrences and 395 deaths during follow-up. Physical activity was not associated with the risk of recurrence in men (HR model 2: 1.48, 95% confidence interval [CI] 0.83-2.65) or in women (HR model 2: 0.95, 95% CI 0.52-1.74). In contrast, physical activity was associated with a 28% lower risk of mortality during 10 years of follow up (HR model 3: 0.72, 95% CI 0.57-0.91). The inverse association was stronger in patients with a first deep vein thrombosis ( HR model 2: 0.59, 95% CI 0.44-0.79) than a pulmonary embolism (HR model 3: 0.87, 95% CI 0.61-1.26).

CONCLUSION

Our results suggest that habitual physical activity prior to incident VTE does not influence the risk of recurrence. In contrast, active individuals were at lower risk of mortality, particularly following deep vein thrombosis.

Incidence of a first venous thrombotic event in people with HIV in the Netherlands: a retrospective cohort study

BACKGROUND

The risk of venous thrombotic events is elevated in people with HIV, but overall risk estimates and estimates specific to immune status and antiretroviral medication remain i mprecise. In this study, we aimed to estimate these parameters in a large cohort of people with HIV in the Netherlands.

METHODS

In this retrospective cohort study, we used the Dutch ATHENA cohort to estimate crude, age and sex standardised, and risk period-specific incidences of a first venous thrombotic event in people with HIV aged 18 years or older attending 12 HIV treatment centres in the Netherlands. Crude and standardised incidences were compared with European population-level studies of venous thrombotic events. We used time-updated Cox regression to estimate the risk of a first venous thrombotic event in association with HIV-specific factors (CD4 cell count, viral load, recent opportunistic infections, antiretroviral medication use) adjusted for traditional risk factors for venous thrombotic events.

FINDINGS

With data collected from Jan 1, 2003, to April 1, 2015, our study cohort included 14 389 people with HIV and 99 762 person-years of follow-up, with a median follow-up of 7·2 years (IQR 3·3-11·1). During this period, 232 first venous thrombotic events occurred, yielding a crude incidence of 2·33 events per 1000 person-years (95% CI 2·04-2·64) and an incidence standardised for age and sex of 2·50 events per 1000 (2·18-2·82). CD4 counts less than 200 cells per μL were independently associated with higher risk of a venous thrombotic event: adjusted hazard ratio (aHR) 3·40 (95% CI 2·28-5·08) relative to counts of 500 cells per μL. A high viral load (aHR 3·15, 95% CI 2·00-5·02; >100 000 copies per mL vs <50 copies per mL) and current or recent opportunistic adverse events (2·80, 1·77-4·44) were also independently associated with higher risk of a venous thrombotic event. There were no associations between any specific antiretroviral drugs and risk of a venous thrombotic event. Rates associated with pregnancy (9·4, 95% CI 4·6-17·3), malignancy (16·7, 10·6-25·1), and hospitalisation (24·4, 19·1-30·6) were lower than primary thromboprophylaxis thresholds suggested by the respective guidelines.

INTERPRETATION

Our findings support neither prescribing primary outpatient thromboprophylaxis nor avoiding any type of antiretroviral medication in people with HIV at high risk of a venous thrombotic event.

FUNDING

Dutch Ministry of Health, Welfare and Sport.

Management of cancer-associated venous thromboembolism - a case-based practical approach

In patients with solid tumours or haematological malignancies, venous thromboembolism (VTE) is a leading cause of death and significantly contributes to morbidity and healthcare resource utilization. Current practice guidelines recommend long-term anticoagulation with low-molecular-weight heparin (LMWH) as the treatment of choice for cancer-associated VTE, based on clinical trial data showing an overall improved safety and efficacy profile of LMWH compared to vitamin K antagonists. However, several open questions remain, e. g. with regard to the intensity and duration of LMWH therapy; moreover, recent real-world evidence indicates that adherence to parenteral anticoagulation with LMWH over the course of treatment is poor in clinical practice. In this regard, the direct oral factor Xa or thrombin inhibitors (DOACs) have emerged as potential alternatives in the management of patients with cancer-associated VTE, albeit findings from randomized controlled studies with a direct head-to-head comparison of DOACs with LMWH, the current standard of care, are still lacking. Based on the case of a lymphoma patient experiencing symptomatic pulmonary embolism during immunochemotherapy, this article aims at both highlighting the current state-of-the-art approach to cancer-associated VTE and pointing out some of the unresolved, controversial issues clinicians have to face when taking care of haematology and oncology patients with already established or with high risk of developing VTE. These issues include the management of patients with incidental pulmonary embolism or thrombocytopenia, the use of DOACs, and the initiation of pharmacological thromboprophylaxis in non-surgical cancer patients.