Epidemiology of the post-thrombotic syndrome

Epidemiology of deep vein thrombosis

Deep vein thrombosis (DVT) is a cause of considerable morbidity worldwide. It is a common clinical disease in the daily practice of several medical disciplines including general medicine, angiology, and internal medicine, as well as of interest to public health because of its preventability and its sensitivity to secular changes in the distribution of population risk factors. In this review we present a comprehensive overview of the epidemiological features of DVT, including incidence and risk factors. Additionally, we give an overview of the burden that DVT poses on modern health care systems.

Advancements in the interventional therapy and nursing care on deep vein thrombosis in the lower extremities

This review examines recent advancements in interventional treatments and nursing care for lower extremity deep vein thrombosis (DVT), highlighting significant innovations and their clinical applications. It discusses the transition to novel anticoagulants such as Direct Oral Anticoagulants, which offer a safer profile and simplified management compared to traditional therapies. Mechanical interventions, including balloon angioplasty and venous stenting, are detailed for their roles in improving immediate and long-term vascular function in acute DVT cases. Furthermore, the use of image-guided techniques is presented as essential for enhancing the accuracy and safety of DVT interventions. Additionally, this study outlines advances in nursing care strategies, emphasizing comprehensive preoperative and postoperative evaluations to optimize patient outcomes. These evaluations facilitate tailored treatment plans, crucial for managing the complex needs of DVT patients. Long-term care strategies are also discussed, with a focus on patient education to ensure adherence to treatment protocols and to prevent recurrence. The synthesis aims to inform healthcare professionals about cutting-edge practices in DVT management, promoting a deeper understanding of how these advancements can be integrated into clinical practice. It also underscores the necessity for ongoing research to address challenges such as cost-effectiveness and patient compliance, ensuring that future treatments are both accessible and effective.

Directional Femoral Ultrasound-Guided Compression Technique Using in Percutaneous Mechanical Thrombectomy for Acute Deep Vein Thrombosis: A Retrospective Cohort Study

OBJECTIVE

The study aimed to investigate the early results of directional femoral ultrasound-guided compression technique (UCT) using in percutaneous mechanical thrombectomy (PMT) for acute deep vein thrombosis (DVT).

METHODS

Consecutive single-center patients with acute iliofemoral DVT who underwent PMT from January 2020 to December 2021 were included. Directional femoral UCT was used to adjust the PMT catheter into the residual thrombus in the inguinal region by ultrasound compression to improve the thrombus clearance rate. Patients were retrospectively analyzed and divided into 2 groups based on PMT with or without directional femoral UCT. The primary efficacy outcome was the incidence of post-thrombotic syndrome (PTS) at 24-month follow-up. The secondary efficacy outcomes included common femoral venous thrombus removal grade, total thrombus removal grade, venous primary patency rate, and incidence of moderate-to-severe PTS at 24-month follow-up. The safety outcomes included complications, major bleeding events, and death at 24-month follow-up.

RESULTS

A total of 96 patients were included in the study: 42 patients underwent PMT with directional femoral UCT and 54 patients underwent PMT without UCT. There was no significant difference in baseline characteristics between the 2 groups. The percentages of patients achieved common femoral venous thrombus removal grade 3 and total thrombus removal grade 3 were significantly higher in the PMT with UCT group than those in the PMT without UCT group (p<0.001). The 24-month primary patency rate was significantly higher in the PMT with UCT group than that in the PMT without UCT group (90.0% vs 71.2%, p=0.027). The incidence of PTS was significantly lower in the PMT with UCT group (10.0%) than that in the PMT without UCT group (28.8%) (p=0.027).

CONCLUSION

PMT with directional femoral UCT could improve the thrombus clearance rate and primary patency rate of acute iliofemoral DVT and might decrease the incidence of PTS compared to traditional PMT treatment without UCT.

CLINICAL IMPACT

Residual thrombus in common femoral vein is a difficult problem associated with higher incidence of PTS. Few studies have focused on common femoral venous thrombus clearance. PMT with directional femoral UCT could improve the thrombus clearance rate and primary patency rate of acute iliofemoral DVT, and might decrease the incidence of PTS compared to traditional PMT treatment without UCT. Directional femoral UCT is recommended in PMT treatment of acute iliofemoral DVT.

Development and validation of a risk prediction model and prediction tools for post-thrombotic syndrome in patients with lower limb deep vein thrombosis

PURPOSE

Our research aims to compare the predictive performance of decision tree algorithms (DT) and logistic regression analysis (LR) in constructing models, and develop a Post-Thrombotic Syndrome (PTS) risk stratification tool.

METHODS

We retrospectively collected and analyzed relevant case information of 618 patients diagnosed with DVT from January 2012 to December 2021 in three different tertiary hospitals in Jiangxi Province as the modeling group. Additionally, we used the case information of 212 patients diagnosed with DVT from January 2022 to January 2023 in two tertiary hospitals in Hubei Province and Guangdong Province as the validation group. We extracted electronic medical record information including general patient data, medical history, laboratory test indicators, and treatment data for analysis. We established DT and LR models and compared their predictive performance using receiver operating characteristic (ROC) curves and confusion matrices. Internal and external validations were conducted. Additionally, we utilized LR to generate nomogram charts, calibration curves, and decision curves analysis (DCA) to assess its predictive accuracy.

RESULTS

Both DT and LR models indicate that Year, Residence, Cancer, Varicose Vein Operation History, DM, and Chronic VTE are risk factors for PTS occurrence. In internal validation, DT outperforms LR (0.962 vs 0.925, z = 3.379, P < 0.001). However, in external validation, there is no significant difference in the area under the ROC curve between the two models (0.963 vs 0.949, z = 0.412, P = 0.680). The validation results of calibration curves and DCA demonstrate that LR exhibits good predictive accuracy and clinical effectiveness. A web-based calculator software of nomogram (https://sunxiaoxuan.shinyapps.io/dynnomapp/) was utilized to visualize the logistic regression model.

CONCLUSIONS

The combination of decision tree and logistic regression models, along with the web-based calculator software of nomogram, can assist healthcare professionals in accurately assessing the risk of PTS occurrence in individual patients with lower limb DVT.

Quality of Life after Venous Stenting for Post-thrombotic Syndrome and the Effect of Inflow Disease

OBJECTIVE

Patients with PTS experience an impaired quality of life (QoL). We aimed to study QoL in patients stented for post thrombotic syndrome (PTS) and analyze the influence of different parameters.

METHODS

Patients stented for PTS after iliofemoral deep vein thrombosis were asked to complete the Chronic Venous Disease Quality of Life Questionnaire (CIVIQ-20) and the Short Form Health Survey (SF-36) in this cross-sectional study. All other data were collected retrospectively. Primary endpoints were median CIVIQ-20 and physical (PCS) and mental (MCS) component summary SF-36 scores. The influence of age, sex, and years between the procedure and completion of questionnaire were investigated using a multivariate linear regression model. Wilcoxon signed rank test compared the PCS and MCS with the normative. Effects of inflow from the deep femoral vein (DFV) and/or the femoral vein (FV) on QoL was analyzed in patients with patent stents.

RESULTS

The response rate was 70.3% (n = 45/64). Time period (median) from stenting to questionnaire completion was 6.6 years (IQR: 8.0). Most stents were placed unilateral left-sided (73.3%). For patients with patent stents (n = 42) median CIVIQ-20 was 35.5 (IQR: 17.3), higher than the minimum of 20.0 (P < .001). Median PCS of 44.7 (IQR: 14.2) was lower (P < .001), and MCS of 55.9 (IQR: 7.1) higher (P = .001) than the normative (50.0). Time since stenting and sex were not associated with QoL. Age was a significant predictor [standardized coefficient ß = .36, P = .04] for QoL using the CIVIQ-20, but not for the SF-36. Inflow disease did not impact QoL, but patients with occluded stents (n = 3) had poor functioning levels.

CONCLUSION

Quality of life is impaired after venous stenting for PTS, particularly physical functioning, among patients with an open stent, but was similar between patients with good and impaired inflow. Patients with a permanent stent occlusion had the lowest QoL.

Healthcare utilization and expenditures among patients with venous thromboembolism following gastrointestinal cancer surgery

BACKGROUND

We sought to assess healthcare utilization and expenditures among patients who developed venous thromboembolism (VTE) after gastrointestinal cancer surgery.

METHODS

Patients who underwent surgery for esophageal, gastric, hepatic, biliary duct, pancreatic, and colorectal cancer between 2013 and 2020 were identified using the MarketScan database. Entropy balancing was performed to obtain a cohort that was well balanced relative to different clinical covariates. Generalized linear models were used to compare 1-year postdischarge costs among patients who did and did not develop a postoperative VTE.

RESULTS

Among 20,253 individuals in the analytical cohort (esophagus [n = 518 {2.6%}], stomach [n = 970 {4.8%}], liver [n = 608 {3.0%}], bile duct [n = 294 {1.5%}], pancreas [n = 1511 {7.5%}], colon [n = 12,222 {60.3%}], and rectum [n = 4130 {20.4%}]), 894 (4.4%) developed VTE. Overall, most patients were male (n = 10,656 [52.6%]), aged between 55 and 64 years (n = 10,372 [51.2%]), and were employed full time (n = 11,408 [56.3%]). On multivariable analysis, VTE was associated with higher inpatient (mean difference [MD], $17,547; 95% CI, $15,141-$19,952), outpatient (MD, $8769; 95% CI, $7045-$10,491), and pharmacy (MD, $2811; 95% CI, $2509-$3113) expenditures (all P < .001). Furthermore, patients who developed VTE had higher out-of-pocket costs for inpatient (MD, $159; 95% CI, $66-$253) and pharmacy (MD, $122; 95% CI, $109-$136) services (all P < .001).

CONCLUSION

Among privately insured patients aged <65 years, VTE was associated with increased healthcare utilization and expenditures during the first year after discharge.

Diagnosis of post-thrombotic syndrome: International union of phlebology (UIP) survey of medical specialists

OBJECTIVE

To review the current approaches to the diagnosis of Post-Thrombotic Syndrome (PTS) and to evaluate the potential need for a diagnostic tool.

METHOD

Medical specialists were invited to participate in an online survey of their current approaches to the diagnosis and management of PTS, including the use of scoring systems, diagnostic imaging techniques and the extent the practitioner reviews the patient's venous history.

RESULTS

502 participants completed the survey. Over 80% obtained imaging reports to confirm a history of deep vein thrombosis (DVT). 72% of participants always obtained an up-to-date duplex ultrasound for PTS diagnosis. Over 50% did not use a scoring system for either PTS diagnosis or management. 65% of the participants agreed that a new system for PTS diagnosis should be devised.

CONCLUSION

Heterogeneity was observed in methods of diagnosing PTS by medical practitioners with frequent use of medical imaging studies and moderate use of scoring systems. Development of a new diagnostic tool for PTS should be considered for future studies.

Exploration on the effect of anserine on the alleviation of DVT and its molecular mechanism

Background

This study aimed to explore the regulatory effect of anserine on HUVEC cell injury and thrombosis in deep venous thrombosis (DVT) rats, and to elucidate the underlying molecular mechanisms.

Methods

Non-targeted metabolomics data analyses were conducted using an ultra-performance liquid chromatography system Vanquish UHPLC and mass spectrometer to detect plasma metabolism profiles. The transcriptome sequencing and gene intervention experiments were performed to verify the regulatory effect. Further in vivo and in vitro experiments were performed. Enzyme-linked immunosorbent assay was used to detect the levels of P-selectin, E-selectin, and vWF, hematoxylin-eosin (HE) staining was performed to observe thrombotic and inflammatory cell infiltration, flow cytometry and TUNEL assays were performed to detect apoptosis, and qPCR and WB assays were conducted to determine the gene and protein expression.

Results

Anserine alleviated HUVECs injury, reduced adhesion molecule expression, and inflammation. It decreased P-selectin, E-selectin, vWF, THBD, TFPI levels, and apoptosis while promoting NOS3, ET-1, and NO release in HUVECs. In DVT rats, anserine reduced P-selectin, E-selectin, vWF, thrombosis, cell infiltration, apoptosis, and promoted NO release. Transcriptome sequencing and gene intervention confirmed anserine's regulation of the PI3K-Akt pathway and coagulation via MYB. CARNMT1, a regulatory enzyme for anserine metabolism, increased anserine content, inhibiting coagulation, thrombosis, cell infiltration, and promoting NO release in rats.

Conclusion

This study confirmed anserine could alleviate DVT by improving the inflammatory response, inhibiting blood agglutination, and promoting vasodilation, providing new potential therapeutic targets, important scientific evidence for the development of DVT management, and new clues for an in-depth understanding of its molecular mechanisms.

A pharmacoepidemiological nested case-control study of risk factors for venous thromboembolism with the focus on diabetes, cancer, socioeconomic group, medications, and comorbidities

OBJECTIVES

A pharmacoepidemiological study to assess VTE risk factors in a diabetes-rich population.

METHODS

The study comprised 299,590 individuals. We observed 3450 VTEs and matched them with 15,875 controls using a nested case-control approach and collected data on comorbidities and prescriptions. By multivariable conditional logistic regression, we calculated ORs with 95%CIs for comorbidities and medications to evaluate their associations with VTE.

RESULTS

Diabetes (aOR 2.16; 95%CI 1.99-2.34), inflammatory bowel disease (1.84; 1.27-2.66), and severe psychiatric disorders (1.72; 1.43-2.05) had the strongest associations among the non-cancer comorbidities. Pancreatic (12.32; 7.11-21.36), stomach (8.57; 4.07-18.03), lung and bronchus (6.26; 4.16-9.43), and ovarian (6.72; 2.95-15.10) cancers were ranked as high-risk for VTE. Corticosteroids, gabapentinoids, psychotropic drugs, risedronic acid, and pramipexole were most strongly associated (aOR exceeding 1.5) with VTE. Insulin (3.86; 3.33-4.47) and sulphonylureas (2.62; 2.18-3.16) had stronger associations than metformin (1.65; 1.49-1.83). Statins and lercanidipine (0.78; 0.62-0.98) were associated with a lowered risk of VTE.

CONCLUSIONS

In this cohort, with 50% diabetes prevalence, pancreatic, stomach, lung and bronchus, and ovarian cancers were strongly associated with VTE. Corticosteroids, gabapentinoids, and psychotropic medications had the strongest associations with VTE among medications. This may be valuable for generating hypotheses for the further research. Lercanidipine may be a novel protective medication against VTE.

To Compare the Effectiveness of Low-Molecular-Weight Heparin and Unfractionated Heparin in Reducing Lower Limb Girth in Deep Vein Thrombosis

INTRODUCTION

Treating deep vein thrombosis (DVT) using a once-daily dose of enoxaparin offers greater convenience and the possibility of home-based care for certain patients, as opposed to a continuous infusion of unfractionated heparin (UFH). The study aimed to determine the most cost-effective thromboprophylaxis between low-molecular-weight heparin (LMWH) and UFH for hospitalized patients.

MATERIALS AND METHODS

After obtaining clearance from the institutional ethical committee, the study was conducted in the Department of General Surgery, Sri Devaraj Urs Medical College, over a period of six months. Informed consent was obtained from all 46 patients included in this study. The participants were divided into two groups: group A received LMWH and group B received UFH.

RESULTS

The mean age in group A was 59.8 + 10.6 years and in group B was 54.9 + 12.3 years. There was no significant difference in the girth of the lower limb between the groups during the follow-up period (p > 0.05). In group A, there was a highly significant reduction in lower limb girth from day one to day five (p < 0.0001), day five to day 10 (p < 0.0001), and day one to day 10 (p < 0.0001). In group B, there was no significant reduction from day one to day five (p = 0.06), but there was a significant reduction from day five to day 10 (p = 0.001) and day one to day 10 (p = 0.001).

CONCLUSION

Treatment with LMWH as an anticoagulant significantly reduced the lower extremity girth and thrombus thickness in cases of DVT when compared to UFH.

A meta-analysis of the medium- to long-term outcomes in patients with chronic deep venous disease treated with dedicated venous stents

OBJECTIVE

This review summarizes the safety profile, stent patency, and clinical effectiveness of dedicated venous stents for the treatment of chronic deep venous disease. The approaches to stenting and post-procedural management of different vascular units are also explored.

METHODS

The MEDLINE and Embase databases were searched for pertinent literature published from January 2010 to January 2023. Outcomes related to post-stenting symptoms and health-related quality of life were described narratively. A meta analysis was conducted to evaluate stent patency, ulcer healing, bleeding, and 30-day stent thrombosis, and these outcomes were presented as proportion event rates.

RESULTS

Seventeen studies were identified comprising of 2218 patients. 62.7% of individuals had post-thrombotic stenosis or occlusion. The majority of patients (78.6%) were noted to have complete occlusions of their deep veins before stenting. Eleven different dedicated venous stents were deployed. At 12 months, the primary patency rate was 83% (95% confidence interval [CI]: 76%-90%), the primary-assisted patency rate was 90% (95% CI: 85%-96%), and the secondary patency rate was 95% (95% CI: 92%-98%). A significant improvement in health-related quality of life was demonstrated after intervention. In total, 68.8% (95% CI: 52.0%-83.7%) of ulcers healed at the last follow-up. The remaining symptomatic changes were described narratively; improvements in pain, venous claudication, and edema after stenting were observed. Seventeen deaths occurred, but none were linked to the stenting procedures. A total of 159 cases (7.2% of patients) of in-stent stenosis were observed, whereas 110 stents (5.0% of patients) were occluded. The incidence of major and minor bleeding was 1.7% (95% CI: 1.0%-2.5%) and 3.2% (95% CI: 1.3%-5.6%), respectively, more commonly seen in patients undergoing hybrid intervention.

CONCLUSIONS

Deep venous stenting using dedicated venous stents is a safe technique to treat chronic deep venous stenosis and/or occlusion. Within the limitations of this study, deep venous stenting is associated with good patency rates and symptomatic improvement.

Under the dual effect of inflammation and pulmonary fibrosis, CTD-ILD patients possess a greater susceptibility to VTE

As an autoimmune disease, the persistent systemic inflammatory response associated with connective tissue disease (CTD) is involved in the development of venous thromboembolism (VTE). However, clinical data showed that the risk of VTE in patients differed between subtypes of CTD, suggesting that different subtypes may have independent mechanisms to promote the development of VTE, but the specific mechanism lacks sufficient research at present. The development of pulmonary fibrosis also contributes to the development of VTE, and therefore, patients with CTD-associated interstitial lung disease (CTD-ILD) may be at higher risk of VTE than patients with CTD alone or patients with ILD alone. In addition, the activation of the coagulation cascade response will drive further progression of the patient's pre-existing pulmonary fibrosis, which will continue to increase the patient's risk of VTE and adversely affect prognosis. Currently, the treatment for CTD-ILD is mainly immunosuppressive and antirheumatic therapy, such as the use of glucocorticoids and janus kinase-inhibitors (JAKis), but, paradoxically, these drugs are also involved in the formation of patients' coagulation tendency, making the clinical treatment of CTD-ILD patients with a higher risk of developing VTE challenging. In this article, we review the potential risk factors and related mechanisms for the development of VTE in CTD-ILD patients to provide a reference for clinical treatment and prevention.

Genetic associations of protein-coding variants in venous thromboembolism

Previous genetic studies of venous thromboembolism (VTE) have been largely limited to common variants, leaving the genetic determinants relatively incomplete. We performed an exome-wide association study of VTE among 14,723 cases and 334,315 controls. Fourteen known and four novel genes (SRSF6, PHPT1, CGN, and MAP3K2) were identified through protein-coding variants, with broad replication in the FinnGen cohort. Most genes we discovered exhibited the potential to predict future VTE events in longitudinal analysis. Notably, we provide evidence for the additive contribution of rare coding variants to known genome-wide polygenic risk in shaping VTE risk. The identified genes were enriched in pathways affecting coagulation and platelet activation, along with liver-specific expression. The pleiotropic effects of these genes indicated the potential involvement of coagulation factors, blood cell traits, liver function, and immunometabolic processes in VTE pathogenesis. In conclusion, our study unveils the valuable contribution of protein-coding variants in VTE etiology and sheds new light on its risk stratification.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

A systematic review and meta-analysis of risk prediction models for post-thrombotic syndrome in patients with deep vein thrombosis

Objective

This systematic review and meta-analysis aimed to systematically evaluate the prediction models for the risk of post-thrombotic syndrome (PTS) in deep vein thrombosis (DVT) patients.

Methods

This systematic review and meta-analysis was guided by the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). A systematic search on the following electronic database: PubMed/MEDLINE, EMBASE, and Cochrane Library, and Chinese databases such as WANFANG and CNKI was conducted to look for relevant articles based on the research question. The risk of bias for each studies included was carried out based on Prediction Model Risk of Bias Assessment Tool (PROBAST).

Results

We identified 10 studies that developed a total of 13 clinical prediction models for PTS risk in DVT patients, 3 models were externally validated, 2 models were temporally validated. The top 5 predictors were: BMI (N = 9), Varicose vein (N = 6), Baseline Villalta Score (N = 6), Iliofemoral thrombosis (N = 5), and Age (N = 4). The high risk of bias was from the analysis domain, which the number of participants and selection of predictors often did not meet the requirements of PROBAST. A random-effects meta-analysis of C-statistics was conducted, the pooled discrimination was C-statistic 0.75, 95%CI (0.69, 0.81).

Conclusion

Among the 13 PTS risk prediction models reported in this study, no prediction model has been applied to clinical practice due to the lack of external validation. In the development of prediction models, most models were not standardized in data analysis. It is recommended that future studies on the design and implementation of prediction models refer to Transparent reporting of a multivariable prediction model for individual prognosis or diagnosis (TRIPOD) and PROBAST.

Immune cell-mediated venous thrombus resolution

Herein, we review the current processes that govern experimental deep vein thrombus (DVT) resolution. How the human DVT resolves at the molecular and cellular level is not well known due to limited specimen availability. Experimentally, the thrombus resolution resembles wound healing, with early neutrophil-mediated actions followed by monocyte/macrophage-mediated events, including neovascularization, fibrinolysis, and eventually collagen replacement. Potential therapeutic targets are described, and coupling with site-directed approaches to mitigate off-target effects is the long-term goal. Similarly, timing of adjunctive agents to accelerate DVT resolution is an area that is only starting to be considered. There is much critical research that is needed in this area.

TILE pilot trial study protocol: Tinzaparin Lead-in to Prevent the Post-Thrombotic syndrome study protocol

INTRODUCTION

The post-thrombotic syndrome (PTS) is a form of chronic venous insufficiency due to a prior ipsilateral deep venous thrombosis (DVT). This is a frequent complication that develops in 20%-50% of patients after a proximal DVT and is associated with significant healthcare, economic and societal consequences. In the absence of effective and well-tolerated treatment options for established PTS, effective preventative measures are needed. Anticoagulation itself reduces the risk of PTS, and low-molecular-weight heparin may reduce this further through anti-inflammatory properties targeting the initial acute inflammatory phase of DVT.

METHODS AND ANALYSIS

The Tinzaparin Lead-In to Prevent the Post-Thrombotic syndrome pilot trial is an investigator-initiated, multicentre, open-label assessor-blinded trial that will randomise patients with first acute symptomatic common femoral or iliac DVT to receive either a 3-week lead-in course of tinzaparin, followed by rivaroxaban (experimental arm) or rivaroxaban alone (control arm). Its primary objectives are to assess: (1) proportion of PTS at 6 months using the Villalta scale and (2) study feasibility, which consists of (a) the proportion of screened patients eligible for the study, (2) the proportion of eligible patients recruited and (c) the proportion of recruited patients adherent to treatment (defined as at least 80% of drug taken). This study will determine the feasibility of a subsequent larger definitive trial. Secondary outcomes include change of quality of life scores, PTS severity, global improvement, patient satisfaction, bleeding, recurrent venous thromboembolism, leg pain, death and lost to follow-up. Target recruitment will be a total of 60 participants, recruited at 5-6 centres.

ETHICS AND DISSEMINATION

Primary ethics approval was received from the Sunnybrook Health Sciences Center Research Ethics Board (approval ID 3315). Results of the study will be disseminated via peer-reviewed presentation at scientific conferences and open access publication.

TRIAL REGISTRATION NUMBER

NCT04794569.

A systematic evaluation and meta-analysis of early prediction of post-thrombotic syndrome

Objective

Post-thrombotic syndrome (PTS) is the most common long-term complication in patients with deep venous thrombosis, and the prevention of PTS remains a major challenge in clinical practice. Some studies have explored early predictors and constructed corresponding prediction models, whereas their specific application and predictive value are controversial. Therefore, we conducted this systematic evaluation and meta-analysis to investigate the incidence of PTS and the feasibility of early prediction.

Methods

We systematically searched databases of PubMed, Embase, Cochrane and Web of Science up to April 7, 2023. Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of the included articles, and the OR values of the predictors in multi-factor logistic regression were pooled to assess whether they could be used as effective independent predictors.

Results

We systematically included 20 articles involving 8,512 subjects, with a predominant onset of PTS between 6 and 72 months, with a 2-year incidence of 37.5% (95% CI: 27.8-47.7%). The results for the early predictors were as follows: old age OR = 1.840 (95% CI: 1.410-2.402), obesity or overweight OR = 1.721 (95% CI: 1.245-2.378), proximal deep vein thrombosis OR = 2.335 (95% CI: 1.855-2.938), history of venous thromboembolism OR = 3.593 (95% CI: 1.738-7.240), history of smoking OR = 2.051 (95% CI: 1.305-3.224), varicose veins OR = 2.405 (95% CI: 1.344-4.304), and baseline Villalta score OR = 1.095(95% CI: 1.056-1.135). Meanwhile, gender, unprovoked DVT and insufficient anticoagulation were not independent predictors. Seven studies constructed risk prediction models. In the training set, the c-index of the prediction models was 0.77 (95% CI: 0.74-0.80) with a sensitivity of 0.75 (95% CI: 0.68-0.81) and specificity of 0.69 (95% CI: 0.60-0.77). In the validation set, the c-index, sensitivity and specificity of the prediction models were 0.74(95% CI: 0.69-0.79), 0.71(95% CI: 0.64-0.78) and 0.72(95% CI: 0.67-0.76), respectively.

Conclusions

With a high incidence after venous thrombosis, PTS is a complication that cannot be ignored in patients with venous thrombosis. Risk prediction scoring based on early model construction is a feasible option, which helps to identify the patient's condition and develop an individualized prevention program to reduce the risk of PTS.

Systematic Review and Meta-analysis of the Additional Benefit of Pharmacological Thromboprophylaxis for Endovenous Varicose Vein Interventions

OBJECTIVE

The primary objective of this systematic review and meta-analysis was to elucidate the rate of venous thromboembolism (VTE) after endovenous interventions for varicose veins in the presence of pharmacological and mechanical thromboprophylaxis versus mechanical thromboprophylaxis alone.

BACKGROUND

The VTE rate after endovenous procedures for varicose veins is higher than other day-case procedures and could be reduced with pharmacological thromboprophylaxis.

METHODS

The review followed Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines with a registered protocol (PROSPERO: CRD42021274963). Studies of endovenous intervention for superficial venous incompetence reporting the predefined outcomes with at least 30 patients were eligible. Data were pooled with a fixed effects model.

RESULTS

There were 221 trials included in the review (47 randomized trial arms, 105 prospective cohort studies, and 69 retrospective studies). In randomized trial arms, the rate of deep venous thrombosis with additional pharmacological thromboprophylaxis was 0.52% (95% CI, 0.23%-1.19%) (9 studies, 1095 patients, 2 events) versus 2.26% (95% CI, 1.81%-2.82%) (38 studies, 6951 patients, 69 events) with mechanical thromboprophylaxis alone. The rate of pulmonary embolism in randomized trial arms with additional pharmacological thromboprophylaxis was 0.45% (95% CI, 0.09-2.35) (5 studies, 460 participants, 1 event) versus 0.23% (95% CI, 0.1%-0.52%) (28 studies, 4834 participants, 3 events) for mechanical measures alone. The rate of EHIT grade III to IV was 0.35% (95% CI, 0.09-1.40) versus 0.88% (95% CI, 0.28%-2.70%). There was 1 VTE-related mortality and 1 instance of major bleeding, with low rates of minor bleeding.

CONCLUSIONS

There is a significant reduction in the rate of DVT with additional pharmacological thromboprophylaxis and routine prescription of anticoagulation after endovenous varicose vein intervention should be considered. VTE risk for individual study participants is heterogeneous and risk stratification in future randomized interventional studies is critical to establish the clinical effectiveness and safety of additional pharmacological thromboprophylaxis.

Evaluation of safety and performance of a new prototype self-expandable nitinol venous stent in an ovine model

Objective

Our study was a prospective in vivo study performed on an animal model to evaluate the safety and performance of a novel venous stent designed specifically for venous applications.

Methods

The novel stents were implanted in the inferior vena cava of nine sheep. The stents were deployed with different distances between the closed cell rings to test for if the segments might migrate after being deployed at maximal distance. Three different total lengths were 9, 11, and 13 cm. After 1, 3, and 6 months, vascular injury, thrombus, neointima coverage, and stent migration were evaluated through computed tomography venography and histopathology. Imaging, histology, and integration data were analyzed for each group.

Results

All stents were deployed successfully, and all sheep survived until the time of harvesting. In all cases, the native blood vessel sections were intact. The segmented stent parts showed a differently pronounced tissue coverage, depending on the duration of the implantation.

Conclusions

The new nitinol stent is safe and feasible to implant in the venous system with a rapid surface coverage. Alteration of stent length did not affect the development of neointimal formation and did not cause migration.

Epidemiology and prevention of venous thromboembolism

Venous thromboembolism, that consists of the interrelated conditions deep-vein thrombosis and pulmonary embolism, is an under-appreciated vascular disease. In Western regions, approximately 1 in 12 individuals will be diagnosed with venous thromboembolism in their lifetime. Rates of venous thromboembolism are lower in Asia, but data from other regions are sparse. Numerous risk factors for venous thromboembolism have been identified, which can be classified as acute or subacute triggers (provoking factors that increase the risk of venous thromboembolism) and basal or acquired risk factors (which can be modifiable or static). Approximately 20% of individuals who have a venous thromboembolism event die within 1 year (although often from the provoking condition), and complications are common among survivors. Fortunately, opportunities exist for primordial prevention (prevention of the development of underlying risk factors), primary prevention (management of risk factors among individuals at high risk of the condition) and secondary prevention (prevention of recurrent events) of venous thromboembolism. In this Review, we describe the epidemiology of venous thromboembolism, including the incidence, risk factors, outcomes and opportunities for prevention. Meaningful health disparities exist in both the incidence and outcomes of venous thromboembolism. We also discuss these disparities as well as opportunities to reduce them.

Incidence and Significance of Deep Venous Reflux in Patients Treated with Saphenous Vein Ablation

BACKGROUND

Venous ablation (VA) of the saphenous vein is the most common procedure performed for venous insufficiency. The incidence of concomitant deep venous reflux (DVR) in patients undergoing VA is unknown. Our hypothesis is that patients undergoing saphenous VA with concomitant DVR exhibit a higher clinical, etiology, anatomy, and pathophysiology (CEAP) stage and less relief after VA compared to patients without DVR.

METHODS

Electronic medical records of patients treated with saphenous VA at a tertiary care center from March 2012 to June 2016 were reviewed. Patients were divided into 2 groups based on presence or absence of DVR on initial ultrasound (US) before saphenous VA. Patient characteristics and outcomes were compared. A telephone survey was conducted to assess long-term symptomatic relief, compliance with compression, and pain medication use. Subgroup analysis of patients with post-thrombotic versus primary DVR was performed.

RESULTS

362 patients underwent 497 ablations, and the incidence of DVR (>1 sec) was 20% (N = 71). Patients with DVR were significantly more likely to be male (46.4% vs. 32.1%, P = 0.021) and of Black race (21.2% vs. 5.5%, P = 0.0001) compared to patients without DVR. Patients with DVR were more likely to have a history of deep vein thrombosis (DVT) (15.1% vs. 7.9%, P = 0.045), but there was no difference in other comorbidities. There was no significant difference in presenting symptoms, CEAP stage, or symptom severity based on numeric rating scale (NRS) (0-10) for pain and swelling. Clinical success of saphenous VA was comparable between the 2 groups, but patients with DVR were more likely to develop endovenous heat-induced thrombosis (EHIT) II-IV (6% vs. 1%, P = 0.002). After a mean follow-up of 26 months, there was still no difference in pain or swelling scores, but patients with DVR were more likely to use compression stockings and used them more frequently. Only 11 of 71 patients with DVR had a history of DVT. Patients with post-thrombotic DVR were significantly older than patients with primary DVR (67.3 vs. 57.2, P = 0.038) and exhibited a trend toward more advanced venous disease (C4-C6: 45.4% vs. 33.3%, P = 0.439).

CONCLUSIONS

In this study, 20% of patients undergoing saphenous VA demonstrated DVR, which was more common in Black men. Presence of DVR is associated with increased risk of EHIT after saphenous VA but does not seem to impact disease severity or clinical relief after ablation. Larger studies are needed to understand outcome differences between post-thrombotic and primary DVR.

Heart Disease and Stroke Statistics-2023 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2023 Statistical Update is the product of a full year's worth of effort in 2022 by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. The American Heart Association strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional COVID-19 (coronavirus disease 2019) publications, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Systematic Review and Meta-Analysis of the Pooled Rate of Post-Thrombotic Syndrome After Isolated Distal Deep Venous Thrombosis

OBJECTIVE

To identify the rate of post-thrombotic syndrome (PTS) after isolated distal deep venous thrombosis (IDDVT) by performing a meta-analysis of the rate of PTS across randomised and observational studies.

DATA SOURCES

MEDLINE, Embase, the Cochrane Controlled Trials Register, Clinicaltrials.gov, European Union Clinical Trials, International Standard Randomised Controlled Trial Number, and the Australian and New-Zealand Trials Registries.

REVIEW METHODS

This review followed PRISMA guidelines using a registered protocol (CRD42021282136). Databases were searched up to December 2021 and prospective studies reporting the development of post-thrombotic syndrome were included; these were pooled with the meta-analysis.

RESULTS

The results showed a post-thrombotic rate of 17% (95% CI 11 - 26%) (seven studies, 217 cases, 1 105 participants). Heterogeneity was high (I2 = 89%). On meta-regression, the rate of post-thrombotic syndrome was not correlated with the length of follow up (p = .71). Three studies (302 participants) reported the severity of post-thrombotic syndrome: 78% were mild (Villalta score 5 - 9); 11% were moderate (Villalta score 10 - 14), and 11% were severe (Villalta score ≥ 15).

CONCLUSION

The risk of post-thrombotic syndrome after IDDVT was one in five and the risk of severe clinical manifestations, including ulceration, was one in 50. There was significant clinical, methodological, and statistical heterogeneity between studies and a substantial risk of bias from pooled studies. Randomised trials to support interventions for prevention of post-thrombotic syndrome are urgently needed.

A vein wall cell atlas of murine venous thrombosis determined by single-cell RNA sequencing

Deep vein thrombosis (DVT) is a common clinical problem, but its cellular and molecular mechanisms remain incompletely understood. In this study, we performed single-cell RNA sequencing on mouse inferior vena cava (IVC) 24 h after thrombus-inducing IVC ligation or sham operation. 9 cell types composed of multiple subpopulations were identified. Notable transcriptomic changes induced by DVT included a marked inflammatory response, elevated hypoxia, and globally reduced myogenesis. Analysis of individual cell populations revealed increased inflammation and reduced extracellular matrix production across smooth muscle cells and fibroblasts, juxtaposed against an early phenotypic shift in smooth muscle cell populations away from a contractile state. By characterizing the transcriptomic changes in the vein wall during acute venous thrombosis at the single-cell level, this work provides novel insights into early pathological events in the vein wall that may potentiate thrombus formation and result in long term adverse venous remodeling.

Predictors of long-term outcomes after catheter-directed thrombolysis combined with stent implantation in acute deep vein thrombosis secondary to iliac vein compression

The purpose of this study is to analyze predictive factors for long-term clinical outcomes after catheter-directed thrombolysis (CDT) combined with stent implantation for acute deep vein thrombosis (DVT) secondary to iliac vein compression (IVC). A retrospective analysis was performed to review clinical data and follow-up information on 52 patients who underwent CDT combined with stent implantation for acute DVT secondary to IVC from June 2015 to March 2020. Clinical outcomes including stent patency and incidence of postthrombotic syndrome (PTS) were investigated using Kaplan-Meier analysis. All included patients were categorized into 2 groups according to the presence of PTS. Potential risk factors, including age, gender, degree of iliac vein stenosis, time from onset to treatment, dosage of thrombolytic agent, stent extending below the inguinal ligament, and duration of anticoagulation for PTS were evaluated using multivariate logistic regression analysis. Over a median follow-up of 24 months, 4 individuals underwent reintervention due to in-stent stenosis or stent compression. Primary stent patency was 98.1% at 1 month, 94.2% at 6 months, 90.4% at 12 months, and 88.5% at 24 months. Freedom from PTS was 98.1% at 6 months, 84.6% at 12 months, and 75% at 24 months. No treatment-related mortality or morbidity was observed. Based on the development of PTS, 13 patients with PTS were classified into group A and 39 patients without PTS were regarded as group B. Upon multivariate logistic regression analysis, key prognostic factors for PTS were degree of iliac vein stenosis and time from onset to treatment. CDT combined with stent implantation is safe and effective for acute DVT secondary to IVC in the long-term perspective. Severe iliac vein stenosis and longer period from onset to treatment may be associated with a higher risk of PTS.

A systematic approach to venous thromboembolism prevention: a focus on UK experience

Venous thromboembolism (VTE) remains a leading cause of preventable morbidity and mortality associated with hospitalization. Despite evidence that providing appropriate thromboprophylaxis to those at risk of VTE in hospital, recent data suggest that the delivery of thromboprophylaxis remains suboptimal across the globe, with a lack of standardization in approach to VTE prevention. This review considers the role of VTE risk assessment and interventions to improve the implementation of the VTE prevention pathway and highlights the systematic approach to VTE prevention adopted in England and its impact. Finally, the critical areas for further research and the emerging data presented during the 2022 ISTH annual congress in London, UK, are summarized.

The association between iliac vein compression degree and characteristics of first diagnosed left lower extremity deep vein thrombosis

Objective

This study aimed to investigate the association between the left common iliac vein (CIV) compression degree and characteristics of first diagnosed left lower extremity deep vein thrombosis (DVT).

Patients and methods

This was a single-center retrospective observational study. Between January 2015 and June 2022, first diagnosed left lower extremity DVT patients with enhanced computed tomography of lower extremities were included. Patient demographics, comorbidities, risk factors, DVT characteristics, and CIV compression degree were collected and analyzed. Logistic regressions were performed to evaluate the odds ratio (OR) with a 95% confidence interval (CI) of iliofemoral or mixed DVT vs. compression percentage. The association between compression percentage and iliofemoral or mixed DVT was evaluated on a continuous scale with restricted cubic splines (RCS). The association between compression percentage and thrombus burden was evaluated using the Spearman test.

Results

A total of 196 (mean age, 61.8 ± 16.1 years; 86 males) patients were included. The median CIV compression percentage in iliofemoral or mixed DVT patients was significantly greater than in non-iliofemoral or non-mixed DVT, respectively (64.4 vs. 46.6%, p < 0.001; 67.8 vs. 54.8%, p = 0.004). CIV compression >50% was associated with significantly increased morbidity of iliofemoral DVT (adjusted OR, 2.96; 95% CI, 1.58-5.52; p = 0.001) or mixed DVT (adjusted OR, 2.39; 95% CI, 1.19-4.81; p = 0.014). RCS showed that a greater compression percentage was associated with a continuously increased OR of iliofemoral DVT (overall p = 0.003, non-linear p = 0.577) or mixed DVT (overall p = 0.020, non-linear p = 0.771). CIV compression percentage had a positive correlation with thrombus burden (rs = 0.284, p < 0.001).

Conclusion

A greater left CIV compression percentage may be associated with increasing likelihood of more proximal location and severe clot extent in first diagnosed left lower extremity DVT.

A prospective marker for the prediction of postoperative deep venous thrombosis: Neutrophil extracellular traps

Deep venous thrombosis (DVT) is a common medical complication in patients with lumbar fractures. The current study aimed to investigate the predictive value of neutrophil extracellular traps (NETs) in postoperative DVT formation in patients with lumbar fractures and to develop a nomogram relating clinical admission information for prediction. Patients who underwent open reduction and pedicle screw internal fixation in the treatment of single-segment lumbar fracture in the Department of Spine Surgery, the First Affiliated Hospital of Nanjing Medical University, from December 2020 to June 2022 were enrolled in this study. Baseline data and laboratory results were collected from enrollees, and the primary study endpoint event was the occurrence of DVT in patients after surgery. Multivariable logistic regression analysis was used to identify risk factors associated with higher odds of DVT after surgery. A nomogram was constructed using the results of the multivariable model. The calibration plot and receiver operating characteristics (ROC) curve were used to show the satisfactory predictive capacity of the model. Of these 393 patients who did not have DVT preoperatively, 79 patients developed it postoperatively, and 314 did not, respectively. Multivariate analysis showed that higher body mass index (BMI) (BMI between 24 and 28: RR = 1.661, 95% CI = 0.891-3.094; BMI ≤28: RR = 5.625, 95% CI = 2.590-12.217; reference: BMI <24), neutrophils (RR = 1.157, 95% CI 1.042-1.285), D-dimer (RR = 1.098, 95% CI 1.000-1.206), and citrullinated histone H3 (CitH3) (RR = 1.043, 95% CI 1.026-1.060) were independent risk factors for postoperative DVT. Using the multivariable analysis, we then constructed a nomogram to predict DVT, which was found to have an area under the curve of 0.757 (95% CI = 0.693-0.820). Calibration plots also showed the satisfied discrimination and calibration of the nomogram. In conclusion, patients with lumbar fractures with postoperative DVT had higher levels of NETs in the circulation preoperatively compared to those without postoperative DVT. Furthermore, based on BMI, D-dimer, neutrophils, and CitH3, we developed a predictive model to predict postoperative DVT incidence in these patients.

Investigating the role of receptor interacting protein kinase 3 in venous thrombosis

Objective

Venous thromboembolism is a disease that encompasses both deep vein thrombosis and pulmonary embolism. Recent investigations have shown that receptor interacting protein kinase 3 (RIPK3), a protein known for its role in the programmed form of cell death necroptosis, may play a role in thrombosis. Specifically, RIPK3 has been shown to promote platelet activation in arterial thrombosis and mixed lineage kinase domain-like pseudokinase (MLKL), a protein downstream of RIPK3 in the necroptosis pathway, has been shown to promote neutrophil extracellular trap formation in deep vein thrombosis. This investigation sought to comprehensively investigate the role of RIPK3 in deep vein thrombogenesis.

Methods

The inferior vena cava ligation and stenosis models of deep vein thrombosis were used in C57BL/6J, RIPK3 wild-type (Ripk3 ^+/+ ) and RIPK3-deficient (Ripk3 ^-/- ) mice. Downstream tissue analyses included measurement of thrombus weight and histological and Western blot analysis of tissues for markers of necroptosis and cell death. A subset of C57BL/6J mice were treated with a RIPK3 inhibitor to determine the effect on venous thrombosis.

Results

C57BL/6J mice showed significant increases in thrombus weight from 6 to 48 hours. During the same time frame, RIPK3 progressively accumulated in the vein wall (a 35-fold increase from 0 to 48 hours). RIPK3 was present in the thrombus; however, it decreased with time. Although present in the thrombus, MLKL was nearly undetectable in the vein wall by Western blot at any timepoint. Immunostaining confirmed the high accumulation of RIPK3 in the vein wall, primarily colocalized to endothelial and smooth muscle cells. Phosphorylated MLKL, the active form of MLKL and executioner of necroptotic cell death, was detectable by immunostaining in the thrombus, but was present at low to undetectable levels in the vein wall. Propidium iodide and terminal deoxynucleotidyl transferase dUTP nick end labeling staining revealed a high burden of necrotic and apoptotic cells within the thrombus at 48 hours, but a relatively lower burden within the vein wall. Despite robust accumulation of RIPK3 within the vessel wall and the thrombus, knockout and inhibition of RIPK3 failed to impact thrombus incident or weight at 48 hours after inferior vena cava ligation. Neutrophil extracellular trap burden did not differ between Ripk3 ^+/+ and Ripk3 ^-/- mice.

Conclusions

In mice, the vein wall responded to deep vein thrombosis induction with elevation of RIPK3 without showing markers of necroptosis and apoptosis. Studies using genetic or pharmacological inhibition of RIPK3 suggest that this cell death mediator may not have a major role in the acute phase of venous thrombogenesis. Further investigation is needed to determine if RIPK3 plays a potentially non-necroptotic role within the vein wall during later stages of thrombus resolution and vein wall remodeling.

Derivation, validation and assessment of a novel nomogram-based risk assessment model for venous thromboembolism in hospitalized patients with lung cancer: A retrospective case control study

Purpose

This study aimed to develop and validate a specific risk-stratification nomogram model for the prediction of venous thromboembolism(VTE) in hospitalized patients with lung cancer using readily obtainable demographic, clinical and therapeutic characteristics, thus guiding the individualized decision-making on thromboprophylaxis on the basis of VTE risk levels.

Methods

We performed a retrospective case–control study among newly diagnosed lung cancer patients hospitalized between January 2016 and December 2021. Included in the cohort were 234 patients who developed PTE and 936 non-VTE patients. The patients were randomly divided into the derivation group (70%, 165 VTE patients and 654 non-VTE patients) and the validation group (30%, 69 VTE patients and 282 non-VTE patients). Cut off values were established using a Youden´s Index. Univariate and multivariate regression analyses were used to determine independent risk factors associated with VTE. Variance Inflation Factor(VIF) was used for collinearity diagnosis of the covariates in the model. The model was validated by the consistency index (C-index), receiver operating characteristic curves(ROC) and the calibration plot with the Hosmer-Lemeshow goodness-of-fit test. The clinical utility of the model was assessed through decision curve analysis(DCA). Further, the comparison of nomogram model with current models(Khorana, Caprini, Padua and COMPASS-CAT) was performed by comparing ROC curves using the DeLong’s test.

Results

The predictive nomogram modle comprised eleven variables: overweight(24-28) defined by body mass index (BMI): [odds ratio (OR): 1.90, 95% confidence interval (CI): 1.19-3.07], adenocarcinoma(OR:3.00, 95% CI: 1.88-4.87), stageIII-IV(OR:2.75, 95%CI: 1.58-4.96), Central venous catheters(CVCs) (OR:4.64, 95%CI: 2.86-7.62), D-dimer levels≥2.06mg/L(OR:5.58, 95%CI:3.54-8.94), PT levels≥11.45sec(OR:2.15, 95% CI:1.32-3.54), Fbg levels≥3.33 g/L(OR:1.76, 95%CI:1.12-2.78), TG levels≥1.37mmol/L (OR:1.88, 95%CI:1.19-2.99), ROS1 rearrangement(OR:2.87, 95%CI:1.74-4.75), chemotherapy history(OR:1.66, 95%CI:1.01-2.70) and radiotherapy history(OR:1.96, 95%CI:1.17-3.29). Collinearity analysis with demonstrated no collinearity among the variables. The resulting model showed good predictive performance in the derivation group (AUC 0.865, 95% CI: 0.832-0.897) and in the validation group(AUC 0.904,95%CI:0.869-0.939). The calibration curve and DCA showed that the risk-stratification nomogram had good consistency and clinical utility. Futher, the area under the ROC curve for the specific VTE risk-stratification nomogram model (0.904; 95% CI:0.869-0.939) was significantly higher than those of the KRS, Caprini, Padua and COMPASS-CAT models(Z=12.087, 11.851, 9.442, 5.340, all P<0.001, respectively).

Conclusion

A high-performance nomogram model incorporated available clinical parameters, genetic and therapeutic factors was established, which can accurately predict the risk of VTE in hospitalized patients with lung cancer and to guide individualized decision-making on thromboprophylaxis. Notably, the novel nomogram model was significantly more effective than the existing well-accepted models in routine clinical practice in stratifying the risk of VTE in those patients. Future community-based prospective studies and studies from multiple clinical centers are required for external validation.

Machine learning-based prediction of the post-thrombotic syndrome: Model development and validation study

Background

Prevention is highly involved in reducing the incidence of post-thrombotic syndrome (PTS). We aimed to develop accurate models with machine learning (ML) algorithms to predict whether PTS would occur within 24 months.

Materials and methods

The clinical data used for model building were obtained from the Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis study and the external validation cohort was acquired from the Sun Yat-sen Memorial Hospital in China. The main outcome was defined as the occurrence of PTS events (Villalta score ≥5). Twenty-three clinical variables were included, and four ML algorithms were applied to build the models. For discrimination and calibration, F scores were used to evaluate the prediction ability of the models. The external validation cohort was divided into ten groups based on the risk estimate deciles to identify the hazard threshold.

Results

In total, 555 patients with deep vein thrombosis (DVT) were included to build models using ML algorithms, and the models were further validated in a Chinese cohort comprising 117 patients. When predicting PTS within 2 years after acute DVT, logistic regression based on gradient descent and L1 regularization got the highest area under the curve (AUC) of 0.83 (95% CI:0.76–0.89) in external validation. When considering model performance in both the derivation and external validation cohorts, the eXtreme gradient boosting and gradient boosting decision tree models had similar results and presented better stability and generalization. The external validation cohort was divided into low, intermediate, and high-risk groups with the prediction probability of 0.3 and 0.4 as critical points.

Conclusion

Machine learning models built for PTS had accurate prediction ability and stable generalization, which can further facilitate clinical decision-making, with potentially important implications for selecting patients who will benefit from endovascular surgery.

Extended Anticoagulation After Pulmonary Embolism: A Multicenter Observational Cohort Analysis

Background Pulmonary embolism (PE) has a long-term risk of adverse events, which can be prevented by extended anticoagulation. We compared clinical characteristics and outcomes between patients treated with 2-year extended anticoagulation and those who were not, in a population who had completed an initial phase of 3 to 6 months of anticoagulant therapy after acute PE. Methods and Results Observational cohort analysis of patients with PE who survived an initial phase of 3 to 6 months anticoagulation. Primary efficacy outcome was all-cause death or recurrent venous thromboembolism. Primary safety outcome was major bleeding. In total, 858 (71.5%) patients were treated with and 341 (28.5%) were treated without extended anticoagulant therapy during the active study period. Age <65 years, intermediate-high or high-risk index PE, normal platelet count, and the absence of concomitant antiplatelet treatment were independently associated with the prescription of extended anticoagulation. The mean duration of the active phase was 2.1±0.3 years. The adjusted rate of the primary efficacy outcome was 2.1% in the extended group and 7.7% in the nonextended group (P<0.001) for patients treated with extended anticoagulant therapy. Rate of bleeding were similar between the extended anticoagulant group and the nonextended group. Conclusions Extended oral anticoagulation over 2 and a half years after index PE seems to provide a net clinical benefit compared with no anticoagulation in patients with PE selected to receive extended anticoagulation. Randomized clinical trials are warranted to explore the potential benefit of extended anticoagulation in patients with PE, especially those with transient provoking factors but residual risk.

Successful endovascular treatment with a stent graft for chronic deep vein thrombosis with multiple arteriovenous fistulas: a case report

Background

Deep vein thrombosis with arteriovenous fistulas is rare, with few therapeutic options available for chronic-phase deep vein thrombosis. Moreover, the effectiveness of endovascular treatment for chronic-phase deep vein thrombosis with arteriovenous fistulas has not been established. We describe herein a case of successful endovascular treatment for chronic deep vein thrombosis with multiple arteriovenous fistulas.

Case presentation

We describe the case of a 72-year-old Asian woman who had begun experiencing left leg swelling and intermittent claudication 2 years prior. Enhanced computed tomography revealed left common iliac vein occlusion with vein-to-vein collateral formation and several arteriovenous fistulas. Angiography and ultrasound showed the arteriovenous fistulas to run from the common and internal iliac arteries to the external iliac and superficial femoral veins. We opted against surgical repair for the arteriovenous fistulas due to their complex nature and complicated morphology. Since her condition was progressive, endovascular treatment with a stent graft was performed for the deep vein thrombosis, after which her symptoms gradually improved. Four months following the procedure, enhanced computed tomography confirmed remarkable reduction of the vein-to-vein collaterals and arteriovenous fistulas.

Conclusions

In the present case, enhanced computed tomography with a stent graft was effective in improving symptoms. This strategy may therefore be a treatment option for intractable chronic deep vein thrombosis with arteriovenous fistulas.

Postthrombotic syndrome and quality of life after deep vein thrombosis in patients treated with edoxaban versus warfarin

Background

Postthrombotic syndrome (PTS) is a long-term complication after deep vein thrombosis (DVT) and can affect quality of life (QoL). Pathogenesis is not fully understood but inadequate anticoagulant therapy with vitamin K antagonists is a known risk factor for the development of PTS.

Objectives

To compare the prevalence of PTS after acute DVT and the long-term QoL following DVT between patients treated with edoxaban or warfarin.

Methods

We performed a long-term follow-up study in a subset of patients with DVT who participated in the Hokusai-VTE trial between 2010 and 2012 (NCT00986154). Primary outcome was the prevalence of PTS, defined by the Villalta score. The secondary outcome was QoL, assessed by validated disease-specific (VEINES-QOL) and generic health-related (SF-36) questionnaires.

Results

Between 2017 and 2020, 316 patients were enrolled in 26 centers in eight countries, of which 168 (53%) patients had been assigned to edoxaban and 148 (47%) to warfarin during the Hokusai-VTE trial. Clinical, demographic, and thrombus-specific characteristics were comparable for both groups. Mean (SD) time since randomization in the Hokusai-VTE trial was 7.0 (1.0) years. PTS was diagnosed in 85 (51%) patients treated with edoxaban and 62 (42%) patients treated with warfarin (adjusted odds ratio 1.6, 95% CI 1.0-2.6). Mean differences in QoL scores between treatment groups were not clinically relevant.

Conclusion

Contrary to our hypothesis, the prevalence of PTS tended to be higher in patients treated with edoxaban compared with warfarin. No differences in QoL were observed. Further research is warranted to unravel the role of anticoagulant therapy on development of PTS.

Fibrinogen and Factor XIII in Venous Thrombosis and Thrombus Stability

As the third most common vascular disease, venous thromboembolism is associated with significant mortality and morbidity. Pathogenesis underlying venous thrombosis is still not fully understood. Accumulating data suggest fibrin network structure and factor XIII-mediated crosslinking are major determinants of venous thrombus mass, composition, and stability. Understanding the cellular and molecular mechanisms mediating fibrin(ogen) and factor XIII production and function and their ability to influence venous thrombogenesis and resolution may inspire new anticoagulant strategies that target these proteins to reduce or prevent venous thrombosis in certain at-risk patients. This article summarizes fibrinogen and factor XIII biology and current knowledge of their function during venous thromboembolism.

British Lymphology Society's position paper for management of people with lymphoedema in presence of deep vein thrombosis: a summary

There is some confusion surrounding the management of people with lymphoedema in the presence of deep vein thrombosis (DVT). This may be in relation to the suitability of commencing compression therapy or regarding the continuation of compression therapy in those who develop DVT. The purpose of this British Lymphology Society position paper is to support evidence-based practice and debunk the myths surrounding the management of DVT and lymphoedema.

Heart Disease and Stroke Statistics-2022 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2022 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population and an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, and the global burden of cardiovascular disease and healthy life expectancy.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Cost-effectiveness Analysis of AngioJet and CDT for Lower Extremity Deep Vein Thrombosis Among Chinese Population

AngioJet has sufficient safety and efficacy in the treatment of acute and subacute lower extremity deep vein thrombosis (LEDVT). But the price of consumables used by AngioJet is relatively high and there is a lack of relevant research on health economics to measure the benefits to patients. Objective of this study is to estimate the cost effectiveness of AngioJet compared with catheter-directed thrombolysis (CDT) among Chinese population. Using a Markov decision model, we compared the 2 treatment strategies in patients with LEDVT. The model captured the development of post-thrombotic syndrome (PTS), recurrent venous thromboembolism, and treatment-related adverse events within a lifetime horizon and the perspective of a third-party payer. Model uncertainty was assessed with one-way and Monte Carl sensitivity analyses. The clinical inputs were obtained from the literature. Costs obtained from the hospital accounts and the literature are expressed in US dollars ($). Utilities were defined as quality adjusted life years (QALY). In cost-effectiveness analysis, AngioJet accumulated $1064.6445/QALY compared with $2080.1561/QALY after CDT treatment alone. AngioJet has higher long-term cost-effectiveness than CDT at a willingness to pay threshold of $11 233.52. One-way sensitivity analysis showed that the utilities of PTS and post-LEDVT state had significant influence on the results and the model maintained a strong stability under  ± 10% fluctuation of utilities. Monte Carl sensitivity analysis shows that AngioJet model has strong stability and AngioJet has higher long-term cost-effectiveness than CDT. AngioJet is likely to be a cost-effective alternative to the CDT for patients with LEDVT.

Impact of direct oral anticoagulants on evolution of post-thrombotic syndrome

BACKGROUND

The effect of direct oral anticoagulants (DOACs) on evolution of a post-thrombotic syndrome (PTS) is unknown.

METHODS AND RESULTS

This retrospective study included patients (n = 98) with a PTS occurring after a proximal deep-vein thrombosis (DVT). The PTS progression was assessed by the Villalta scale change over time from when patients were started on DOACs for the prevention of DVT recurrence according to current guidelines. The PTS evolution was compared between patients with good (n = 63) vs. poor (n = 35) DOACs adherence, defined by using a medication possession ratio cut point of 0.80. The mean follow-up was 41.7 ± 17.7 and 27.5 ± 10.5 months in patients with good or poor adherence, respectively. The primary endpoint of PTS improvement (defined when the Villalta score became <5 and/or decreased by ≥30% from baseline) was higher in patients with good vs. poor adherence (66.7% vs. 20%, p < 0.001). None of the patients in the good adherence group experienced at any time of follow-up the co-primary endpoint of PTS worsening (defined as the Villalta score increase ≥30%), which instead occurred in 12 (34.3%) of those with poor adherence (p < 0.001). All study-defined primary endpoints occurred within 2 years. The mean values of the Villalta partial scores related to the subjective symptoms (patient-rated) and to the potentially reversible physician-rated signs were significantly improved in the good adherence group, while they were unchanged among patients with poor adherence.

CONCLUSIONS

In this study a good vs. poor DOACs adherence was associated with a more favorable progression of PTS over a long-term follow-up. Larger studies are needed to explore the clinical efficacy of DOACs on PTS manifestations.

Extended-Duration Low-Intensity Apixaban to Prevent Recurrence in Patients with Provoked Venous Thromboembolism and Enduring Risk Factors: Rationale and Design of the HI-PRO Trial

Patients with acute venous thromboembolism (VTE) in the setting of transient provoking factors are typically treated with short-term anticoagulation. However, the risk of recurrence may be increased in the presence of enduring risk factors. In such patients, the optimal duration of treatment remains uncertain. HI-PRO is a single-center, double-blind randomized trial. Patients with deep vein thrombosis (DVT) or pulmonary embolism (PE) following a major provoking factor, including major surgery or major trauma, who completed at least 3 months of standard-dose therapeutic anticoagulation and have at least one enduring risk factor (such as obesity or heart failure) will be considered for inclusion. Patients will be randomized to apixaban 2.5 mg twice daily or placebo for 12 months. The primary efficacy outcome will be symptomatic recurrent VTE-a composite of DVT and/or PE at 12 months after randomization. Secondary efficacy outcomes include a composite of death due to cardiovascular causes, nonfatal myocardial infarction, stroke or systemic embolism, major adverse limb events, or coronary or peripheral ischemia requiring revascularization at 12 months, and individual components of these outcomes. The primary safety outcome is major bleeding according to the International Society on Thrombosis and Haemostasis definition. The study plans to enroll 600 patients (300 per arm) to have 80% power for detecting a 75% relative risk reduction in the primary outcome. Active recruitment began in March 2021. HI-PRO will provide clinically meaningful data on whether patients with provoked VTE and enduring risk factors have fewer adverse clinical outcomes if prescribed low-intensity extended-duration anticoagulation.

MUFFIN-PTS trial, Micronized Purified Flavonoid Fraction for the Treatment of Post-Thrombotic Syndrome: protocol of a randomised controlled trial

INTRODUCTION

After deep vein thrombosis, up to 50% of patients develop post-thrombotic syndrome (PTS). PTS is a chronic condition that reduces quality of life (QOL). Cornerstones of PTS treatment include the use of elastic compression stockings but this treatment is usually incompletely effective and is burdensome. Venoactive drugs have been reported to be effective to treat chronic venous insufficiency (CVI). However, the level of evidence supporting their use in CVI in general and in PTS in particular is low.

METHODS AND ANALYSIS

The MUFFIN-PTS trial is an academic, publically funded, multicentre randomised placebo-controlled trial assessing the efficacy of micronised purified flavonoid fraction (MPFF, Venixxa), a venoactive drug, to treat PTS. Eighty-six patients with PTS (Villalta score (VS) ≥5) and experiencing at least two of the following PTS manifestations among daily leg heaviness, cramps, pain or oedema will be randomised to receive 1000 mg of oral MPFF or a similar appearing placebo for 6 months, in addition to their usual PTS treatment. Total study follow-up will be 9 months, with visits at inclusion/baseline, 3, 6 and 9 months. Primary outcome is the proportion of patients with improvement in VS in each group, where improvement is defined as a decrease of at least 30% in VS or a VS <5 in the PTS-affected leg. Main secondary outcomes include QOL and patient satisfaction.

ETHICS AND DISSEMINATION

Primary ethics approval was received from Centre intégré universitaire de santé et de services sociaux (CIUSSS) West-Central Montreal Research Ethics Board. Results of the study will be disseminated via peer-reviewed publications and presentations at scientific conferences.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT03833024); Pre-results.

Neutrophil activation and circulating neutrophil extracellular traps are increased in venous thromboembolism patients for at least one year after the clinical event

Neutrophil activation and neutrophil extracellular traps (NETs) have been associated with the pathogenesis of venous thromboembolism (VTE). Considering VTE-associated chronic sequelae, which suggest that some pathological mechanisms remain after the acute episode, we investigated whether neutrophil activation is increased in patients with a prior VTE at least one year before this investigation. Thirty-seven patients with prior VTE and 37 individuals with no history of VTE were included. Neutrophil activity was evaluated by the expression of the adhesive molecule activation-specific epitopes LFA-1 (CD11a) and MAC-1 (CD11b), chemotaxis, reactive oxygen species (ROS) and by MPO-DNA complexes as markers of NETs. The adhesive molecules sICAM-1 and sVCAM-1, involved in the cross talk between neutrophil and endothelial cells, were also evaluated. Patient neutrophils presented increased CD11a expression before and after TNF-α stimulus, whereas increased CD11b expression was observed only after TNF-α stimulus, as compared to controls. Neutrophil chemotaxis on both, basal state and after IL-8 stimulus, on circulating levels of sICAM-1 and sVCAM-1, and on MPO-DNA complexes were also increased in VTE patients. ROS release was similar between patients and controls. This is, to our knowledge, the first study to investigate neutrophil inflammatory activity in VTE patients a long period after an acute event (approximately 2 years). The results showed altered neutrophil activation patterns in these patients. While activated neutrophils can cause endothelial activation and injury, the activated endothelium can induce the release of NETs with consequent endothelial cytotoxicity, creating a vicious cycle of activation between neutrophils and endothelium that can lead to thrombosis.

Elastic compression stockings to prevent post-thrombotic syndrome in proximal deep venous thrombosis patients without thrombus removal

OBJECTIVE

To evaluate the effectiveness of elastic compression stockings(ECS) in prevention of post-thrombotic syndrome(PTS) in patients suffering from proximal deep venous thrombosis (DVT) who did not receive thrombus removal procedures.

METHODS

In this randomized trial, patients with Iliofemoral venous thrombosis (IFDVT)and Femoral-popliteal venous thrombosis (Fem-pop DVT) who had not undergone thrombus removal procedures were screened at a single medical institution between December 2016 and June 2018. These patients were randomly assigned as an ECS group(wear ECS) and control group(not wear ECS). The primary endpoint was the incidence of PTS based on Villata scale at 24 months. The secondary endpoints included patients' quality of life and symptom severity based on the VEINES-QoL/Sym questionnaire. Recurrent DVT in the same limb, compliance with ECS use and other adverse events were also recorded. Logistic regression analysis was also performed to determine risk factors of PTS.

RESULTS

Two hundred and thirty two patients were included in this study.One hundred and thirteen patients were in the ECS group and 119 in the control group. The incidence of PTS was 42.0% in the ECS group and 57.8% in the control group at 24 months (risk ratio[RR] = 0.726, 95% CI 0.547-0.964; P = .024). VEINES-QoL score was 63.7 ± 4.6 in the ECS group, which was higher than in the control group(60.6 ± 6.9), P < .001. Moreover, VEINES-Sym scores revealed that patients in the ECS group reported better symptom relief than those in the control group (45.8 ± 5.1 vs. 43.8 ± 6.1, P = .014). According to Logistic regression analysis of the entire cohort, IFDVT was a risk factor for PTS (RR=2.253,95% CI 1.136-4.468)and high compliance with use of ECS was protect factor(RR=0.516, 95%CI 0.277-0.961).

CONCLUSIONS

The results suggest that ECS can prevent PTS in patients with IFDVT and Fem-pop DVT who do not receive thrombus removal procedures.

Predictive Ability of a Clinical-Genetic Risk Score for Venous Thromboembolism in Northern and Southern European Populations

Venous thromboembolism (VTE) is a complex, multifactorial problem, the development of which depends on a combination of genetic and acqfiguired risk factors. In a Spanish population, the Thrombo inCode score (or TiC score), which combines clinical and genetic risk components, was recently proven better at determining the risk of VTE than the commonly used model involving the analysis of two genetic variants associated with thrombophilia: the Factor V Leiden (F5 rs6025) and the G20210A prothrombin (F2 rs1799963). The aim of the present case-control study was to validate the VTE risk predictive capacity of the TiC score in a Northern European population (from Sweden). The study included 173 subjects with VTE and 196 controls. All were analyzed for the genetic risk variants included in the TiC gene panel. Standard measures -receiver operating characteristic (ROC) area under the curve (AUC), sensitivity, specificity, and odds ratio (OR)-were calculated. The TiC score returned an AUC value of 0.673, a sensitivity of 72.25%, a specificity of 60.62%, and an OR of 4.11. These AUC, sensitivity, and OR values are all greater than those associated with the currently used combination of genetic variants. A TiC version adjusted for the allelic frequencies of the Swedish population significantly improved its AUC value (0.783). In summary, the TiC score returned more reliable risk estimates for the studied Northern European population than did the analysis of the Factor V Leiden and the G20210A genetic variations in combination. Thus, the TiC score can be reliably used with European populations, despite differences in allelic frequencies.

Venous thromboembolism

Venous thromboembolism, comprising both deep vein thrombosis and pulmonary embolism, is a chronic illness that affects nearly 10 million people every year worldwide. Strong provoking risk factors for venous thromboembolism include major surgery and active cancer, but most events are unprovoked. Diagnosis requires a sequential work-up that combines assessment of clinical pretest probability for venous thromboembolism using a clinical score (eg, Wells score), D-dimer testing, and imaging. Venous thromboembolism can be considered excluded in patients with both a non-high clinical pretest probability and normal D-dimer concentrations. When required, ultrasonography should be done for a suspected deep vein thrombosis and CT or ventilation-perfusion scintigraphy for a suspected pulmonary embolism. Direct oral anticoagulants (DOACs) are the first-line treatment for almost all patients with venous thromboembolism (including those with cancer). After completing 3-6 months of initial treatment, anticoagulation can be discontinued in patients with venous thromboembolism provoked by a major transient risk factor. Patients whose long-term risk of recurrent venous thromboembolism outweighs the long-term risk of major bleeding, such as those with active cancer or men with unprovoked venous thromboembolism, should receive indefinite anticoagulant treatment. Pharmacological venous thromboembolism prophylaxis is generally warranted in patients undergoing major orthopaedic or cancer surgery. Ongoing research is focused on improving diagnostic strategies for suspected deep vein thrombosis, comparing different DOACs, developing safer anticoagulants, and further individualising approaches for the prevention and management of venous thromboembolism.

Prevention of Venous Thromboembolism in Gynecologic Surgery: ACOG Practice Bulletin, Number 232

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are collectively referred to as "venous thromboembolic events" (VTE). Despite advances in prophylaxis, diagnosis, and treatment, VTE remains a leading cause of cost, disability, and death in postoperative and hospitalized patients (1, 2). Beyond the acute sequelae of leg pain, edema, and respiratory distress, VTE may result in chronic conditions, including postthrombotic syndrome (3), venous insufficiency, and pulmonary hypertension. This Practice Bulletin has been revised to reflect updated literature on the prevention of VTE in patients undergoing gynecologic surgery and the current surgical thromboprophylaxis guidelines from the American College of Chest Physicians (4). Discussion of gynecologic surgery and chronic antithrombotic therapy is beyond the scope of this document.

Prevention of Venous Thromboembolism in Gynecologic Surgery: ACOG Practice Bulletin Summary, Number 232

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are collectively referred to as venous thromboembolic events (VTE). Despite advances in prophylaxis, diagnosis, and treatment, VTE remains a leading cause of cost, disability, and death in postoperative and hospitalized patients (1, 2). Beyond the acute sequelae of leg pain, edema, and respiratory distress, VTE may result in chronic conditions, including postthrombotic syndrome (3), venous insufficiency, and pulmonary hypertension. This Practice Bulletin has been revised to reflect updated literature on the prevention of VTE in patients undergoing gynecologic surgery and the current surgical thromboprophylaxis guidelines from the American College of Chest Physicians (4). Discussion of gynecologic surgery and chronic antithrombotic therapy is beyond the scope of this document.

Epidemiology and Genetics of Venous Thromboembolism and Chronic Venous Disease

Venous disease is a term that broadly covers both venous thromboembolic disease and chronic venous disease. The basic pathophysiology of venous thromboembolism and chronic venous disease differ as venous thromboembolism results from an imbalance of hemostasis and thrombosis while chronic venous disease occurs in the setting of tissue damage because of prolonged venous hypertension. Both diseases are common and account for significant mortality and morbidity, respectively, and collectively make up a large health care burden. Despite both diseases having well-characterized environmental components, it has been known for decades that family history is an important risk factor, implicating a genetic element to a patient's risk. Our understanding of the pathogenesis of these diseases has greatly benefited from an expansion of population genetic studies from pioneering familial studies to large genome-wide association studies; we now have multiple risk loci for each venous disease. In this review, we will highlight the current state of knowledge on the epidemiology and genetics of venous thromboembolism and chronic venous disease and directions for future research.