Long-term treatment of venous thromboembolism

The "flipped visit": an innovative method to improve medical student self-efficacy through a structured approach in clinic

BACKGROUND

Specialty clinics can be challenging for students on the internal medicine clerkship. They often lack the specialized knowledge necessary to fully engage in the clinic and may be pushed into an observational role, rather than being afforded meaningful opportunities. These peripheral roles undermine self-efficacy, and, therefore, education and interest. We sought to improve self-efficacy of students attending non-malignant hematology clinic, as well as to enhance interest in hematology and internal medicine.

METHODS

We developed a flipped visit model analogous to the flipped classroom. Students each received pre-readings accompanied and pre-assigned cases with delineated reasons for referral and learning objectives. This model allowed students to prepare the hematology content for visits prior to arrival and then focus their time in clinic on executing visits. Participating students completed pre- and post-clinic surveys. These surveys covered core concepts in self-efficacy and interest in hematology and internal medicine on a five-point Likert scale.

RESULTS

Of 103 students attending hematology clinic, 38 students (37%) opted to participate. Two of the 38 did not complete the post-clinic survey. Students had a statistically significant increase in four of six measures of self-efficacy: evaluation of research relevant to patient care and practicing cost-effective care (p = 0.008 and 0.001, respectively); and creation of a differential diagnosis and treatment plan specific to hematology (both p < 0.001). While pre-clinic student responses expressed interest in more exposure to hematology or a possible career in hematology or internal medicine, this was not changed post-clinic. When comparing their experience to other clinics, 75% and 71% students rated hematology clinic slightly or much better than other medicine clinics and non-medicine clinics, respectively. The flipped visit improved self-efficacy both specific to hematology and more generally. While students rated the experience more highly than other clinics, there was no impact on career interest in hematology or internal medicine.

CONCLUSION

A flipped visit approach to incorporating medical students into hematology clinic that included pre-assigned cases and readings improved self-efficacy and was preferred by students. They may be adopted easily in other ambulatory education settings.

miR-483-5p-Containing exosomes treatment ameliorated deep vein thrombosis‑induced inflammatory response

Peripheral vascular condition, known as deep vein thrombosis (DVT), is a common ailment that may lead to deadly pulmonary embolism. Inflammation is closely connected to venous thrombosis, which results in blood stasis, leading to ischemia and hypoxia, as indicated by research. The objective of this research was to investigate the mechanism by which exosomes derived from adipose stem cells (ADSCs) prevent deep vein thrombosis. Our data showed that Exo-483 effectively reduced the thrombus weight in DVT rats by intravenous injection. Exo-483 decreased the expression of tissue factor (TF) protein, the influx of inflammatory cells into the thrombosed vein wall, and the levels of cytokines in the serum. Furthermore, Exo-483 suppressed the expression of Mitogen-activated protein kinase 1 (MAPK1) and decreased the expression of NLRP3 inflammasomes. In an oxygen-glucose deprivation (OGD) cell model, the tube-forming and migratory abilities of primary human umbilical vein endothelial cells (HUVEC) and EA.hy926 cells were suppressed by Exo-483 pretreatment.Exo-483 is also linked to regulating Dynamin-related protein 1 (DRP1) production downstream of MAPK1.By decreasing the mitochondrial localization and phosphorylation at the S616 site of DRP1, it diminishes the expression of NLRP3 inflammasomes. Moreover, according to Bioinformatics analysis, miR-483-5p was anticipated to target MAPK1. The research conducted by our team revealed that the miR-483-5p exosome derived from ADSCs exhibited anti-inflammatory properties through the modulation of downstream DRP1-NLRP3 expression by targeting MAPK1.The findings of this research propose that miR-483-5p may be regarded as an innovative treatment target for DVT.

Risk assessment tools for bleeding in patients with unprovoked venous thromboembolism: an analysis of the PLATO-VTE study

BACKGROUND

Guidelines suggest indefinite anticoagulation after unprovoked venous thromboembolism (VTE) unless the bleeding risk is high, yet there is no consistent guidance on assessing bleeding risk.

OBJECTIVES

This study aimed to evaluate the performance of 5 bleeding risk tools (RIETE, VTE-BLEED, CHAP, VTE-PREDICT, and ABC-Bleeding).

METHODS

PLATO-VTE, a prospective cohort study, included patients aged ≥40 years with a first unprovoked VTE. Risk estimates were calculated at VTE diagnosis and after 3 months of treatment. Primary outcome was clinically relevant bleeding, as per International Society on Thrombosis and Haemostasis criteria, during 24-month follow-up. Discrimination was assessed by the area under the receiver operating characteristic curve (AUROC). Patients were classified as having a "high risk" and "non-high risk" of bleeding according to predefined thresholds; bleeding risk in both groups was compared by hazard ratios (HRs).

RESULTS

Of 514 patients, 38 (7.4%) had an on-treatment bleeding. AUROCs were 0.58 (95% CI, 0.48-0.68) for ABC-Bleeding, 0.56 (95% CI, 0.46-0.66) for RIETE, 0.53 (95% CI, 0.43-0.64) for CHAP, 0.50 (95% CI, 0.41-0.59) for VTE-BLEED, and 0.50 (95% CI, 0.40-0.60) for VTE-PREDICT. The proportion of high-risk patients ranged from 1.4% with RIETE to 36.9% with VTE-BLEED. The bleeding incidence in the high-risk groups ranged from 0% with RIETE to 13.0% with ABC-Bleeding, and in the non-high-risk groups, it varied from 7.7% with ABC-Bleeding to 9.6% with RIETE. HRs ranged from 0.93 (95% CI, 0.46-1.9) for VTE-BLEED to 1.67 (95% CI, 0.86-3.2) for ABC-Bleeding. Recalibration at 3-month follow-up did not alter the results.

CONCLUSION

In this cohort, discrimination of currently available bleeding risk tools was poor. These data do not support their use in patients with unprovoked VTE.

Discovery of crucial cytokines associated with deep vein thrombus formation by protein array analysis

BACKGROUND

Expanding the number of biomarkers is imperative for studying the etiology and improving venous thromboembolism prediction. In this study, we aimed to identify promising biomarkers or targeted therapies to improve the detection accuracy of early-stage deep vein thrombosis (DVT) or reduce complications.

METHODS

Quantibody Human Cytokine Antibody Array 440 (QAH-CAA-440) was used to screen novel serum-based biomarkers for DVT/non-lower extremity DVT (NDVT). Differentially expressed proteins in DVT were analyzed using bioinformatics methods and validated using a customized array. Diagnostic accuracy was calculated using receiver operating characteristics, and machine learning was applied to establish a biomarker model for evaluating the identified targets. Twelve targets were selected for validation.

RESULTS

Cytokine profiling was conducted using a QAH-CAA-440 (RayBiotech, USA) quantimeter array. Cross-tabulation analysis with Venn diagrams identified common differential factors, leading to the selection of 12 cytokines for validation based on their clinical significance. These 12 biomarkers were consistent with the results of previous array analysis: FGF-6 (AUC = 0.956), Galectin-3 (AUC = 0.942), EDA-A2 (AUC = 0.933), CHI3L1 (AUC = 0.911), IL-1 F9 (AUC = 0.898), Dkk-4 (AUC = 0.88), IG-H3 (AUC = 0.876), IGFBP (AUC = 0.858), Gas-1 (AUC = 0.858), Layilin (AUC = 0.849), ULBP-2 (AUC = 0.813)and FGF-9 (AUC = 0.773). These cytokines are expected to serve as biomarkers, targets, or therapeutic targets to differentiate DVT from NDVT.

CONCLUSIONS

EDA-A2, FGF-6, Dkk-4, IL-1 F9, Galentin-3, Layilin, Big-h3, CHI3L1, ULBP-2, Gas-1, IGFBP-5, and FGF-9 are promising targets for DVT diagnosis and treatment.

How I treat the co-occurrence of venous and arterial thromboembolism: anticoagulation, antiplatelet therapy, or both?

ABSTRACT

Arterial and venous thromboses are classically considered distinct disease states, with arterial thrombosis mediated predominantly by platelets and therefore, treated with antiplatelet therapy, and venous thrombosis mediated by the plasmatic coagulation system and treated with anticoagulation. However, co-occurrence of arterial and venous events is common, and there is increasing evidence of shared risk factors and pathophysiologic overlap. This presents a management challenge: does the patient with venous and arterial thrombosis, require anticoagulation, antiplatelet therapy, or both? Herein, we present a structured approach to the evaluation and management of patients with venous thrombosis who are also at risk for or have a history of an arterial thromboembolic event. We emphasize the importance of defining the indications for antithrombotic therapy, as well as the evaluation of factors that influence both thrombotic and bleeding risk, including disorder-specific and patient-specific factors, as well as the inherent risk balance of antithrombotic therapy regimens. We illustrate this approach in 4 cases, discussing the unique considerations and recent updates in the management of venous thrombosis, acute noncardioembolic ischemic stroke, coronary artery disease and acute myocardial infarction, and peripheral artery disease after revascularization.

Efficacy of Mechanical Thrombectomy in Preventing Post-Thrombotic Syndrome in Acute DVT: A Retrospective Study

Background  Lower limb deep vein thrombosis (DVT) is associated with significant morbidity and death. DVT can result in complications such as postphlebitic syndrome, pulmonary embolism, and death. Combining pretest probability, D-dimer testing, and compression ultrasound imaging enables a safe and convenient study of suspected lower-extremity thrombosis. This study aimed to assess the expanding body of research supporting thrombectomy as a form of DVT therapy. Materials and Methods  A retrospective study was performed on individuals with venous Doppler-confirmed DVT and occlusive thrombus. Four-hundred fifty-one consecutive patients were selected for the study based on the inclusion and exclusion criteria. In this investigation, thrombectomy was the preferred therapeutic approach. Results  The study reports a male predominance of 56.1%. Most patients (25.7%) were between the age of 51 and 60, with 84.7% reporting pain and lower-extremity swelling as the two most common clinical symptoms. The femoral vein was noted as the most frequent site of thrombus in the current research (51.0%), with acute DVT accounting for most cases (85.1%). Most of the patients (97.3%) were primarily asymptomatic after one year of follow-up. Conclusion  Thrombectomy is a reliable treatment modality for DVT patients in regaining venous patency, preventing DVT recurrence, treating post-thrombotic syndrome, and preventing pulmonary embolism.

Graduated elastic compression stockings in the prevention of post-thrombotic syndrome: A systematic review and meta-analysis

BACKGROUND

The effect of graduated elastic compression stockings (ECS) in the prevention of post-thrombotic syndrome (PTS) has been questioned since a large randomized trial found no prophylactic effect of ECS.

OBJECTIVE

To assess the effect of the wearing time of ECS on the incidence of post-thrombotic syndrome (PTS) after proximal deep venous thrombosis, we performed a meta-analysis of the incidence of PTS across randomized and observational studies.

METHOD

PubMed, Embase and Cochrane databases were searched until 12 June 2023 for studies on the effect of ECS on PTS. References of eligible studies were also screened in order to identify other potential studies that might have been missed during the search.

RESULTS

Four studies comprising a total of 1467 patients met our inclusion criteria for early initiation and consistent use of ECS in patients with acute proximal DVT. ECS significantly reduced the incidence of mild-moderate PTS (OR: 0.48; 95% CI: 0.36-0.63) as well as severe PTS (OR: 0.44; 95% CI: 0.28-0.58).

Research progress on venous thrombosis development in patients with malignant tumors

The coexistence of venous thromboembolism (VTE) within patients with cancer, known as cancer-associated thrombosis (CAT), stands as a prominent cause of mortality in this population. Over recent years, the incidence of VTE has demonstrated a steady increase across diverse tumor types, influenced by several factors such as patient management, tumor-specific risks, and treatment-related aspects. Furthermore, mutations in specific genes have been identified as potential contributors to increased CAT occurrence in particular cancer subtypes. We conducted an extensive review encompassing pivotal historical and ongoing studies on CAT. This review elucidates the risks, mechanisms, reliable markers, and risk assessment methodologies that can significantly guide effective interventions in clinical practice.

Management of Deep Vein Thrombosis: An Update Based on the Revised AWMF S2k Guideline

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are the most common manifestations of venous thromboembolism (VTE). Most DVTs affect the lower-extremity veins. Since the symptoms of DVT are non-specific, a prompt and standardised diagnostic work-up is essential to minimise the risk of PE in the acute phase and to prevent thrombosis progression, post-thrombotic syndrome and VTE recurrence in the long-term. Only recently, the AWMF S2k guidelines on Diagnostics and Therapy of Venous Thrombosis and Pulmonary Embolism have been revised. In the present article, we summarize current evidence and guideline recommendations focusing on lower-extremity DVT (LEDVT). Depending on whether the diagnostic work-up is performed by a specialist in vascular medicine or by a primary care physician, different diagnostic algorithms are presented that combine clinical probability, D-dimer testing and diagnostic imaging. The diagnosis of ipsilateral recurrent DVT poses a particular challenge and is presented in a separate algorithm. Anticoagulant therapy is an essential part of therapy, with current guidelines clearly favouring regimens based on direct oral anticoagulants over the traditional sequential therapy of parenteral anticoagulants and vitamin K antagonists. For most DVTs, a duration of therapeutic-dose anticoagulation of at least 3 to 6 months is considered sufficient, and this raises the question of the risk of VTE recurrence after discontinuation of anticoagulation and the need for secondary prophylaxis in the long-term. Depending on the circumstances and trigger factors that have contributed to the occurrence of DVT, management strategies are presented that allow decision-making taking into account the individual bleeding risk and patient's preferences.

Thrombosis recurrence and major bleeding in non-anticoagulated thrombotic antiphospholipid syndrome patients: Prospective study from antiphospholipid syndrome alliance for clinical trials and international networking (APS ACTION) clinical database and repository ("Registry")

BACKGROUND

Long-term anticoagulant therapy is generally recommended for thrombotic antiphospholipid syndrome (TAPS) patients, however it may be withdrawn or not introduced in routine practice.

OBJECTIVES

To prospectively evaluate the risk of thrombosis recurrence and major bleeding in non-anticoagulated TAPS patients, compared to anticoagulated TAPS, and secondly, to identify different features between those two groups.

PATIENTS/METHODS

Using an international registry, we identified non-anticoagulated TAPS patients at baseline, and matched them with anticoagulated TAPS patients based on gender, age, type of previous thrombosis, and associated autoimmune disease. Thrombosis recurrence and major bleeding were prospectively analyzed using Kaplan-Meier method and compared using a marginal Cox's regression model.

RESULTS

As of June 2022, 94 (14 %) of the 662 TAPS patients were not anticoagulated; and 93 of them were matched with 181 anticoagulated TAPS patients (median follow-up 5 years [interquartile range 3 to 8]). The 5-year thrombosis recurrence and major bleeding rates were 12 % versus 10 %, and 6 % versus 7 %, respectively (hazard ratio [HR] 1.38, 95 % confidence interval [CI] 0.53 to 3.56, p = 0.50 and HR 0.53; 95 % CI 0.15 to 1.86; p = 0.32, respectively). Non-anticoagulated patients were more likely to receive antiplatelet therapy (p < 0.001), and less likely to have more than one previous thrombosis (p < 0.001) and lupus anticoagulant positivity (p = 0.01).

CONCLUSION

Fourteen percent of the TAPS patients were not anticoagulated at recruitment. Their recurrent thrombosis risk did not differ compared to matched anticoagulated TAPS patients, supporting the pressing need for risk-stratified secondary thrombosis prevention trials in APS investigating strategies other than anticoagulation.

Bionanoengineered 2D monoelemental selenene for piezothrombolysis

Thrombosis-related diseases represent the leading causes of disability or death worldwide. However, conventional thrombolytic therapies are subjected to narrow therapeutic window, short circulation half-life and bleeding. Herein, we rationally design and develop a safe and efficient nonpharmaceutical thrombolysis strategy based on a specific piezocatalytic effect arising from platelet membrane (PM)-conjugated two-dimensional (2D) piezoelectric selenene, Se-PM nanosheets (NSs). The 2D selenene is fabricated from nonlayered bulk selenium powder by a facile liquid-phase exfoliation method, and the PM conjugation confers selenene with the distinct thrombus-homing feature. Under ultrasonic activation, the piezoelectric characteristic of selenene triggers electrons and holes separation, resulting in generation of reactive oxygen species (ROS) by reacting with surrounding H2O and O2 in the thrombosis microenvironment for thrombolysis. Both systematic in vitro and in vivo assessments demonstrate that the biocompatible Se-PM NSs efficiently degrade erythrocytes, fibrin and artificial blood clots under ultrasound irradiation. Compared to the clinical thrombolytic drug urokinase plasminogen activator, the engineered Se-PM NSs possess excellent thrombolytic efficacy by single treatment in the tail thrombosis animal model without bleeding risk. The engineered Se-PM nanoplatform marks an exciting jumping-off point for research into the application of piezocatalysis in clinical treatment of thrombosis.

Non-coding RNAs regulating endothelial progenitor cells for venous thrombosis: promising therapy and innovation

Venous thromboembolism, which includes deep venous thrombosis (DVT) and pulmonary embolism, is the third most common vascular disease in the world and seriously threatens the lives of patients. Currently, the effect of conventional treatments on DVT is limited. Endothelial progenitor cells (EPCs) play an important role in the resolution and recanalization of DVT, but an unfavorable microenvironment reduces EPC function. Non-coding RNAs, especially long non-coding RNAs and microRNAs, play a crucial role in improving the biological function of EPCs. Non-coding RNAs have become clinical biomarkers of diseases and are expected to serve as new targets for disease intervention. A theoretical and experimental basis for the development of new methods for preventing and treating DVT in the clinic will be provided by studies on the role and molecular mechanism of non-coding RNAs regulating EPC function in the occurrence and development of DVT. To summarize, the characteristics of venous thrombosis, the regulatory role of EPCs in venous thrombosis, and the effect of non-coding RNAs regulating EPCs on venous thrombosis are reviewed. This summary serves as a useful reference and theoretical basis for research into the diagnosis, prevention, treatment, and prognosis of venous thrombosis.

Development and validation of a clinical prediction model for 90-day venous thromboembolism risk following total hip and total knee arthroplasty: a multinational study

BACKGROUND

The risk of venous thromboembolism (VTE) following total hip arthroplasty (THA) and total knee arthroplasty (TKA) is 1.0% to 1.5%, despite uniform thromboprophylaxis.

OBJECTIVES

To develop and validate a prediction model for 90-day VTE risk.

METHODS

A multinational cohort study was performed. For model development, records were used from the Oxford Royal College of General Practitioners Research and Surveillance Centre linked to Hospital Episode Statistics and Office of National Statistics UK routine data. For external validation, data were used from the Danish Hip and Knee Arthroplasty Registry, the National Patient Registry, and the National Prescription Registry. Binary multivariable logistic regression techniques were used for development.

RESULTS

In the UK data set, 64 032 THA/TKA procedures were performed and 1.4% developed VTE. The prediction model consisted of age, body mass index, sex, cystitis within 1 year before surgery, history of phlebitis, history of VTE, presence of varicose veins, presence of asthma, history of transient ischemic attack, history of myocardial infarction, presence of hypertension and THA or TKA. The area under the curve of the model was 0.65 (95% CI, 0.63-0.67). Furthermore, 36 169 procedures were performed in the Danish cohort, of whom 1.0% developed VTE. Here, the area under the curve was 0.64 (95% CI, 0.61-0.67). The calibration slope was 0.92 in the validation study and 1.00 in the development study.

CONCLUSION

This clinical prediction model for 90-day VTE risk following THA and TKA performed well in both development and validation data. This model can be used to estimate an individual's risk for VTE following THA/TKA.

International Normalized Ratio Predicts Recurrence and Bleeding in Patients With Acute Venous Thromboembolism Who Undergo Direct Oral Anticoagulants

Prothrombin time/international normalized ratio (PT/INR) is related to both antithrombotic effect and risk of bleeding. Its role in the prediction of venous thromboembolism (VTE) recurrence and bleeding for patients with acute VTE who undergo direct oral anticoagulants (DOACs) treatment is unclear, despite previous studies revealed some association between them. The predictive efficiency of INR for VTE recurrence and bleeding were analyzed in a retrospective cohort with VTE patients who underwent DOACs treatment. Then its predictive efficiency for VTE recurrence and bleeding were validated in a prospective cohort with the acquired cutoffs range, and compared with anti-Xa level, DASH and VTE-BLEED scores. In the retrospective cohort (n = 1083), the sensitivity and specificity of INR for the prediction of VTE recurrence were 79.4% and 92.8%, respectively. The area under the curve (AUC) was 0.881 (0.803-0.960)(P = .025). The cutoff value of INR was 0.9. The sensitivity and specificity of INR for the prediction of bleeding were 85.7% and 77.9%, respectively. The AUC was 0.876 (0.786-0.967)(P < .001). The cutoff value of INR was 2.1. In the prospective cohort (n = 202), the calibration showed that there were 4 (50%) patients with VTE recurrence, 156 (97.5%) patients with non-recurrence and bleeding (non-R&B), and 20 (58.8%) patients with bleeding in the low (INR < 0.9)(n = 8), intermediate (0.9 ≤ INR ≤ 2.1)(n = 160), and high (INR > 2.1)(n = 34) groups, respectively. The baseline PT/INR value at the initiation of DOACs treatment is an independent predictor for VTE recurrence and bleeding in patients with acute VTE who undergo DOACs treatment.

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.

Machine learning algorithms to predict intraoperative hemorrhage in surgical patients: a modeling study of real-world data in Shanghai, China

BACKGROUND

Prediction tools for various intraoperative bleeding events remain scarce. We aim to develop machine learning-based models and identify the most important predictors by real-world data from electronic medical records (EMRs).

METHODS

An established database of surgical inpatients in Shanghai was utilized for analysis. A total of 51,173 inpatients were assessed for eligibility. 48,543 inpatients were obtained in the dataset and patients were divided into haemorrhage (N = 9728) and without-haemorrhage (N = 38,815) groups according to their bleeding during the procedure. Candidate predictors were selected from 27 variables, including sex (N = 48,543), age (N = 48,543), BMI (N = 48,543), renal disease (N = 26), heart disease (N = 1309), hypertension (N = 9579), diabetes (N = 4165), coagulopathy (N = 47), and other features. The models were constructed by 7 machine learning algorithms, i.e., light gradient boosting (LGB), extreme gradient boosting (XGB), cathepsin B (CatB), Ada-boosting of decision tree (AdaB), logistic regression (LR), long short-term memory (LSTM), and multilayer perception (MLP). An area under the receiver operating characteristic curve (AUC) was used to evaluate the model performance.

RESULTS

The mean age of the inpatients was 53 ± 17 years, and 57.5% were male. LGB showed the best predictive performance for intraoperative bleeding combining multiple indicators (AUC = 0.933, sensitivity = 0.87, specificity = 0.85, accuracy = 0.87) compared with XGB, CatB, AdaB, LR, MLP and LSTM. The three most important predictors identified by LGB were operative time, D-dimer (DD), and age.

CONCLUSIONS

We proposed LGB as the best Gradient Boosting Decision Tree (GBDT) algorithm for the evaluation of intraoperative bleeding. It is considered a simple and useful tool for predicting intraoperative bleeding in clinical settings. Operative time, DD, and age should receive attention.

Comparison of Presentation, Treatment, and Outcomes of Venous Thromboembolism in Long-Term Immobile Patients Based on Age

BACKGROUND

Chronic immobility is prevalent, especially as people age. However, little is known about venous thromboembolism (VTE) outcomes in this population.

OBJECTIVE

To compare the presentation, treatment, and outcomes in chronically immobile (>8 weeks) patients older vs. younger than 75 who presented with VTE.

DESIGN

An observational international registry of patients with VTE.

PARTICIPANTS

Patients with acute VTE from the "Registro Informatizado Enfermedad TromboEmbolica" (RIETE) registry who were chronically immobile.

MAIN MEASURES

Baseline characteristics, presenting signs and symptoms, treatment and outcomes including major bleeding, recurrent VTE, and mortality.

KEY RESULTS

Among 4612 immobile patients (mean age 75.7 years, 34% male), 2127 (46%) presented with pulmonary embolism (PE). Patients >75 years presented more often with dyspnea (44% vs. 38%) or altered mental status (23% vs. 8.1%) and less often with chest pain (13% vs. 18%). The median duration of anticoagulation was shorter in older compared with younger patients [126 vs. 169 days]. During the first 90 days of anticoagulation, major bleeding (4.0% vs. 2.2%), PE-related death (2.5% vs. 1.1%), and bleeding-related death (0.78% vs. 0.26%) occurred more frequently among older patients. In 3550 patients who received anticoagulation beyond 90 days, older patients had more major bleeding [4.23 vs. 2.21 events per 100 patient years]. After anticoagulation discontinuation, recurrent VTE and major bleeding occurred in 11.8 and 9.25 and 1.49 and 0.69 events per 100 patient years, respectively, both in similar rates in both groups. In multivariable analysis, after stopping anticoagulation, VTE recurrence was inversely associated with long-term facility residence [OR 0.51 (0.28-0.92)], anemia [OR 0.63 (0.42-0.95)], and anticoagulation duration < 90 days [OR 0.38 (0.27-0.54)].

CONCLUSIONS

Chronically immobilized patients older than 75 years presenting with VTE experience a high rate of adverse events including major bleeding and recurrent VTE. When considering treatment beyond 90 days, we should account for bleeding, recurrence risk, and associated mortality.

Bleeding and thrombotic events in bevacizumab-treated patients with colorectal cancer on novel oral anticoagulants and antiplatelet medications

Background

Bevacizumab is a humanized monoclonal anti-VEGF antibody often given in combination with fluorouracil-based chemotherapy as therapy for metastatic colorectal cancer (mCRC). The bleeding and thrombotic event rates in the setting of concurrent novel oral anticoagulants with and without aspirin and bevacizumab treatment in patients with mCRC remain unclear.

Methods

462 patients with mCRC at Barnes-Jewish Hospital were identified between December 1, 2016 and December 1, 2021 and screened for concurrent treatment with bevacizumab and anticoagulant or antiplatelet therapy. Demographic and clinical information was extracted by electronic chart review.

Results

21 patients were identified who received bevacizumab and either apixaban or rivaroxaban for mCRC treatment. Aspirin was prescribed in some of these patients within three years of starting apixaban or rivaroxaban. Of the 13 patients without aspirin prescription, nine were given apixaban, and four were given rivaroxaban while on bevacizumab. Four out of nine of the patients who received apixaban had epistaxis, and only one case resulted in any treatment discontinuation. Three out of four of the patients who received rivaroxaban experienced bleeding, and one of these three patients discontinued bevacizumab. We also looked at eight patients who had received aspirin. Two out of seven patients who received apixaban/bevacizumab/aspirin experienced bleeding and discontinued a medication. The patient who received rivaroxaban/bevacizumab/aspirin experienced bleeding and discontinued bevacizumab. No patient experienced adverse thrombotic events.

Conclusions

Patients with mCRC treated with bevacizumab and apixaban with no history of aspirin use within three years have a relatively low risk of bleeding that warrants treatment discontinuation.

Protocol for a modelling study to assess the clinical and cost-effectiveness of indefinite anticoagulant therapy for first unprovoked venous thromboembolism

INTRODUCTION

Deciding whether to stop or extend anticoagulant therapy indefinitely after completing at least 3 months of initial treatment for a first unprovoked venous thromboembolism (VTE) remains a challenge for clinicians, patients and policy makers. Guidelines suggest an indefinite duration of anticoagulant therapy in these patients, yet its benefits, harms and costs have not been formally assessed. The aim of this proposed modelling study is to assess the differences in clinical benefits, harms and costs of stopping versus continuing anticoagulant therapy indefinitely for a first unprovoked VTE.

METHODS AND ANALYSIS

We will develop a probabilistic Markov model, adopting a 1-month cycle length and a lifetime horizon, to estimate life-years, quality-adjusted life-years, costs and the incremental cost-effectiveness ratios for a simulated population of patients with a first unprovoked VTE who will receive indefinite duration of anticoagulant therapy versus a population who will not receive extended treatment after completing 3 months of initial anticoagulant therapy. The economic evaluation will adopt a third-party payer perspective relating to a Canadian publicly funded healthcare system. Estimates for the probability of relevant clinical events will be informed by systematic reviews and meta-analyses, while costs and utility values will be obtained from published Canadian sources. Stratified analyses based on sex, age and site of initial VTE will also be performed to identify subgroups of patients with a first unprovoked VTE in whom continuing anticoagulant therapy indefinitely might prove to be clinically beneficial and cost-effective over stopping treatment. We will also conduct sensitivity and scenario analyses to assess robustness of study findings to changes in individual or groups of key parameters.

ETHICS AND DISSEMINATION

Ethical approval is not applicable for this study. The results will be disseminated through presentations at relevant conferences and in a manuscript that will be submitted to a peer-reviewed journal.

Overall haemostatic potential (OHP) assay can risk stratify for venous thromboembolism recurrence in anticoagulated patients

Assessing the risk of recurrent venous thromboembolism (VTE), particularly when patients are anticoagulated, remains a major challenge largely due to the lack of biomarkers. Blood was sampled from adult VTE patients recruited between January 2018 and September 2020, while receiving therapeutic anticoagulation. Results were compared to 144 healthy subjects (34.7% male, median age 42 years). Overall haemostatic potential (OHP) assay, a spectrophotometric assay, was performed on platelet-poor plasma, in which fibrin formation (triggered by small amounts of thrombin (overall coagulation potential, OCP)) and fibrinolysis (by the addition of thrombin and tissue plasminogen activator (OHP)) are simultaneously measured. Results were obtained from 196 patients (52.6% male, mean age 57.1 years). Compared to healthy subjects, VTE patients displayed significantly higher OCP (39.6 vs 34.5 units, p < 0.001) and OHP (9.3 vs 6.4 units, p < 0.001) as well as lower overall fibrinolytic potential (75.6 v s81.1%, p < 0.001). All 16 VTE recurrences, including 11 unprovoked, occurred above an OCP cut-off of 40^th percentile (recurrence rate 4.32/100 patient-years (100PY), 95% confidence interval (CI) 2.39-7.80, p = 0.002). Of 97 patients who subsequently discontinued anticoagulation, all unprovoked VTE recurrences (n = 9) occurred above the 40^th OCP percentile (recurrence rate 9.10/100PY, 95% CI 4.74-17.49, p = 0.005) and the 40^th OHP percentile (recurrence rate 8.46/100PY, 95% CI 4.40-16.25, p = 0.009). Our pilot study demonstrates that the OHP assay can detect a hypercoagulable and hypofibrinolytic state in anticoagulated VTE patients and may be able to risk stratify VTE recurrence, allowing for more individualised decision on long-term anticoagulation. Further larger prospective studies are required.

Protocols for D-Dimer Measurements for Aid to Diagnosis or Exclusion of Venous Thromboembolism

Measuring D-dimer is commonly used as a surrogate to indicate a clot-forming process, with subsequent lysis. This test has two primary intended uses: (1) as aid to diagnosis of various conditions and (2) venous thromboembolism (VTE) exclusion. If the manufacturer cites a VTE exclusion claim, the D-dimer test must only be used in evaluating patients with a non-high or unlikely pretest probability for pulmonary embolism and deep vein thrombosis. D-dimer kits with only aid to diagnosis claim should not be used for VTE exclusion. The intended use of the D-dimer may vary by region, and readership should consult manufacturer instructions for use to assure proper use of the assay. In this chapter, several methods for measuring D-dimer will be described.

D-dimer, a predictor of bad outcome in gastric cancer patients undergoing radical resection

As a marker of hypercoagulability, plasma D-dimer is associated with progression of many cancers but remains controversial in gastric cancer (GC). We aim to investigate the predictive value of D-dimer for postoperative outcomes after radical gastrectomy of GC patients. We enrolled 903 consecutive patients with GC who underwent radical gastrectomy and the clinicopathological characteristics were compared. Risk factors for overall survival (OS) and disease-free survival (DFS) were determined using multivariate cox regression analysis. We also compared the survival difference based on Kaplan-Meier method after a one-to-one propensity score matching (PSM). Patients with elevated D-dimer had older age (p < 0.001), advanced TNM stage (p < 0.001), larger tumor size (p = 0.005), lower 5-year OS rate (32.8% vs 62.6%, p < 0.001) and DFS (29% vs 59.6%, p < 0.001). In multivariate analysis, elevated D-dimer was independently associated with shorter OS [hazard ratio (HR): 1.633, 95% confidence interval (CI) 1.178-2.264, p = 0.003] and DFS (HR: 1.58, 95% CI 1.151-2.169, P = 0.005). After PSM, the 5-year OS rate of patients with elevated D-dimer was still significantly lower than matched group (32.8% vs 40.6%, p = 0.005), so was DFS (29% vs 36.6%, p = 0.008). Preoperative elevated D-dimer is an independent risk factor for GC patients undergoing curative gastrectomy.

C-reactive protein, immunothrombosis and venous thromboembolism

C-reactive protein (CRP) is a member of the highly conserved pentraxin superfamily of proteins and is often used in clinical practice as a marker of infection and inflammation. There is now increasing evidence that CRP is not only a marker of inflammation, but also that destabilized isoforms of CRP possess pro-inflammatory and pro-thrombotic properties. CRP circulates as a functionally inert pentameric form (pCRP), which relaxes its conformation to pCRP* after binding to phosphocholine-enriched membranes and then dissociates to monomeric CRP (mCRP). with the latter two being destabilized isoforms possessing highly pro-inflammatory features. pCRP* and mCRP have significant biological effects in regulating many of the aspects central to pathogenesis of atherothrombosis and venous thromboembolism (VTE), by directly activating platelets and triggering the classical complement pathway. Importantly, it is now well appreciated that VTE is a consequence of thromboinflammation. Accordingly, acute VTE is known to be associated with classical inflammatory responses and elevations of CRP, and indeed VTE risk is elevated in conditions associated with inflammation, such as inflammatory bowel disease, COVID-19 and sepsis. Although the clinical data regarding the utility of CRP as a biomarker in predicting VTE remains modest, and in some cases conflicting, the clinical utility of CRP appears to be improved in subsets of the population such as in predicting VTE recurrence, in cancer-associated thrombosis and in those with COVID-19. Therefore, given the known biological function of CRP in amplifying inflammation and tissue damage, this raises the prospect that CRP may play a role in promoting VTE formation in the context of concurrent inflammation. However, further investigation is required to unravel whether CRP plays a direct role in the pathogenesis of VTE, the utility of which will be in developing novel prophylactic or therapeutic strategies to target thromboinflammation.

Predicting major bleeding during extended anticoagulation for unprovoked or weakly provoked venous thromboembolism

No clinical prediction model has been specifically developed or validated to identify patients with unprovoked venous thromboembolism (VTE) who are at high risk of major bleeding during extended anticoagulation. In a prospective multinational cohort study of patients with unprovoked VTE receiving extended anticoagulation after completing ≥3 months of initial treatment, we derived a new clinical prediction model using a multivariable Cox regression model based on 22 prespecified candidate predictors for the primary outcome of major bleeding. This model was then compared with modified versions of 5 existing clinical scores. A total of 118 major bleeding events occurred in 2516 patients (annual risk, 1.7%; 95% confidence interval [CI], 1.4-2.1). The incidences of major bleeding events per 100 person-years in high-risk and non–high-risk patients, respectively, were 3.9 (95% CI, 3.0-5.1) and 1.1 (0.8-1.4) using the newly derived creatinine, hemoglobin, age, and use of antiplatelet agent (CHAP) model; 3.3 (2.6-4.1) and 1.0 (0.7-1.3) using modified ACCP score, 5.3 (0.6-19.2) and 1.7 (1.4-2.0) using modified RIETE score, 3.1 (2.3-3.9) and 1.1 (0.9-1.5) using modified VTE-BLEED score, 5.2 (3.3-7.8) and 1.5 (1.2-1.8) using modified HAS-BLED score, and 4.8 (1.3-12.4) and 1.7 (1.4-2.0) using modified outpatient bleeding index score. Modified versions of the ACCP, VTE-BLEED, and HAS-BLED scores help identify patients with unprovoked VTE who are at high risk of major bleeding and should be considered for discontinuation of anticoagulation after 3 to 6 months of initial treatment. The CHAP model may further improve estimation of bleeding risk by using continuous predictor variables, but external validation is required before its implementation in clinical practice.

Associations between coagulation factor XII, coagulation factor XI, and stability of venous thromboembolism: A case-control study

BACKGROUND

Pulmonary embolism (PE) is a fatal clinical syndrome that is generally caused by an embolus from unstable deep venous thrombosis (DVT). However, clinical and biochemical factors that are related to the stability of DVT are not fully understood.

AIM

To evaluate the relationships between plasma antigen levels of factor XII (FXII:Ag) and factor XI (FXI:Ag) with the stability of DVT.

METHODS

Patients with DVT and no PE, DVT and PE, and controls with no DVT or PE that matched for age, gender, and comorbidities were included in this study. FXII:Ag and FXI:Ag in peripheral venous blood were measured using enzyme-linked immunosorbent assays.

RESULTS

Using the 95^th percentile of FXI:Ag in patients with DVT and PE as the cut-off, a higher FXI:Ag was associated with a higher risk of unstable DVT (odds ratio: 3.15, 95% confidence interval: 1.18-8.43, P = 0.019). Stratified analyses showed consistent results in patients ≤ 60 years (P = 0.020), but not in those > 60 years (P = 0.346).

CONCLUSION

Higher plasma FXI:Ag might be a marker for unstable DVT, which might be associated with PE in these patients.

Associations between coagulation factor XII, coagulation factor XI, and stability of venous thromboembolism: A case-control study

BACKGROUND

Pulmonary embolism (PE) is a fatal clinical syndrome that is generally caused by an embolus from unstable deep venous thrombosis (DVT). However, clinical and biochemical factors that are related to the stability of DVT are not fully understood.

AIM

To evaluate the relationships between plasma antigen levels of factor XII (FXII:Ag) and factor XI (FXI:Ag) with the stability of DVT.

METHODS

Patients with DVT and no PE, DVT and PE, and controls with no DVT or PE that matched for age, gender, and comorbidities were included in this study. FXII:Ag and FXI:Ag in peripheral venous blood were measured using enzyme-linked immunosorbent assays.

RESULTS

Using the 95^th percentile of FXI:Ag in patients with DVT and PE as the cut-off, a higher FXI:Ag was associated with a higher risk of unstable DVT (odds ratio: 3.15, 95% confidence interval: 1.18-8.43, P = 0.019). Stratified analyses showed consistent results in patients ≤ 60 years (P = 0.020), but not in those > 60 years (P = 0.346).

CONCLUSION

Higher plasma FXI:Ag might be a marker for unstable DVT, which might be associated with PE in these patients.

Pathogenesis of Two Faces of DVT: New Identity of Venous Thromboembolism as Combined Micro-Macrothrombosis via Unifying Mechanism Based on "Two-Path Unifying Theory" of Hemostasis and "Two-Activation Theory of the Endothelium"

Venous thrombosis includes deep venous thrombosis (DVT), venous thromboembolism (VTE), venous microthrombosis and others. Still, the pathogenesis of each venous thrombosis is not clearly established. Currently, isolated distal DVT and multiple proximal/central DVT are considered to be the same macrothrombotic disease affecting the venous system but with varying degree of clinical expression related to its localization and severity. The genesis of two phenotypes of DVT differing in clinical features and prognostic outcome can be identified by their unique hemostatic mechanisms. Two recently proposed hemostatic theories in vivo have clearly defined the character between "microthrombi" and "macrothrombus" in the vascular system. Phenotypic expression of thrombosis depends upon two major variables: (1) depth of vascular wall damage and (2) extent of the injury affecting the vascular tree system. Vascular wall injury limited to endothelial cells (ECs) in sepsis produces "disseminated" microthrombi, but intravascular injury due to trauma extending from ECs to subendothelial tissue (SET) produces "local" macrothrombus. Pathogen-induced sepsis activates the complement system leading to generalized endotheliopathy, which releases ultra large von Willebrand factor (ULVWF) multimers from ECs and promotes ULVWF path of hemostasis. In the venous system, the activated ULVWF path initiates microthrombogenesis to form platelet-ULVWF complexes, which become "microthrombi strings" that produce venous endotheliopathy-associated vascular microthrombotic disease (vEA-VMTD) and immune thrombocytopenic purpura (ITP)-like syndrome. In the arterial system, endotheliopathy produces arterial EA-VMTD (aEA-VMTD) with "life-threatening" thrombotic thrombocytopenic purpura (TTP)-like syndrome. Typically, vEA-VMTD is "silent" unless complicated by additional local venous vascular injury. A local venous vessel trauma without sepsis produces localized macrothrombosis due to activated ULVWF and tissue factor (TF) paths from damaged ECs and SET, which causes distal DVT with good prognosis. However, if a septic patient with "silent" vEA-VMTD is complicated by additional vascular injury from in-hospital vascular accesses, "venous combined micro-macrothrombosis" may develop as VTE via the unifying mechanism of the "two-path unifying theory" of hemostasis. This paradigm shifting pathogenetic difference between distal DVT and proximal/central DVT calls for a reassessment of current therapeutic approaches.

Unprovoked or provoked venous thromboembolism: not the prevalent criterion to decide on anticoagulation extension in clinical practice of various countries-the prospective, international, observational WHITE study

The decision on treatment after a first venous thromboembolism (VTE) to prevent recurrences may be influenced by many factors. The prospective, observational, WHITE study aimed to analyze how this issue was tackled in every-day clinical practice in various countries, which have sensibly different socio-economic conditions and healthcare systems. Doctors active in 79 Internal or Vascular clinical centers in 7 countries (China, Czechia, Poland, Portugal, Russia, Slovakia, and Tunisia) enrolled VTE patients after the maintenance treatment phase. The present report analyzed information, collected in the central database, regarding the baseline characteristics, index events, type and duration of anticoagulant therapy and decision on post-maintenance treatment. From April 2018 to December 2020, 1240 patients were enrolled, 58% with an unprovoked index event. Direct oral anticoagulants (DOACs) were used in > 85% of all cases in China, Poland, Portugal, Russia and Czechia, in 52% in Slovakia and in no patient in Tunisia. The maintenance anticoagulation lasted in average approximately 6 months. Altogether, anticoagulation was stopped in 20%, extended in about 50%, regardless of whether the event was unprovoked or provoked and shifted to antithrombotics (mainly sulodexide or aspirin) in the remaining patients. In conclusion, some differences in VTE patient management were found between countries. The provoked/unprovoked nature of the index event, instead, was not the prevalent criterion to drive the decision on extension of anticoagulation, without large variations between countries. DOACs were the most widely used anticoagulant drugs, whereas > 25% of patients received antithrombotic drugs instead of anticoagulants as extended treatment.

Current Trends in the Duration of Anticoagulant Therapy for Venous Thromboembolism: A Systematic Review

Anticoagulation therapy is the first line and drug of choice for both the treatment and prophylaxis of venous thromboembolism (deep vein thrombosis and/or pulmonary embolism). Anticoagulation drugs, ranging from different preparations of heparin, warfarin, and newer direct oral drugs such as rivaroxaban and dabigatran, work mainly by inhibiting important factors and enzymes in the coagulation cascade by preventing fibrin formation, platelet aggregation, and clot assembly. With recurrent thrombosis and embolisms being a feared complication for many physicians treating such cases, anticoagulation is often extended beyond the initial three- to six-month acute phase after an incident of venous thromboembolism. For some groups of patients, anticoagulation needs to be offered indefinitely to decrease the risk of a recurrent thrombosis. However, this concomitantly increases obvious and dangerous adverse effects such as increased risk of hemorrhage, as the ability to clot is hindered. This tradeoff between recurrent venous thromboembolism and bleeding is what underscores the controversy of the clinical question: for how long should anticoagulation be administered for venous thromboembolism? This review analyzes the use of anticoagulants in different types of venous thromboembolism and remarks on current consensus and trends on the length of anticoagulation treatment. We are doing so while acknowledging that venous thromboembolism management is an active area of research that is rapidly evolving. A literature search was performed looking at recent studies on anticoagulant administration for the treatment of venous thromboembolism with a focus on varying durations and patient populations. Factors that affect clinical decisions of duration are also elucidated. The most clinically relevant anticoagulants were discussed and their effects on the risk of recurrent thrombosis and embolism, and the risk of bleeding in relation to other drugs were analyzed. Ultimately, this article discussed patterns of anticoagulant treatments duration and which patient groups are likely to benefit the most from certain durations, shedding light on the ambiguity in how physicians should approach administering anticoagulation therapy over time for a broad range of presentations of venous thromboembolism.

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.

Long-Term Risk for Major Bleeding During Extended Oral Anticoagulant Therapy for First Unprovoked Venous Thromboembolism : A Systematic Review and Meta-analysis

BACKGROUND

The long-term risk for major bleeding in patients receiving extended (beyond the initial 3 to 6 months) anticoagulant therapy for a first unprovoked venous thromboembolism (VTE) is uncertain.

PURPOSE

To determine the incidence of major bleeding during extended anticoagulation of up to 5 years among patients with a first unprovoked VTE, overall, and in clinically important subgroups.

DATA SOURCES

MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials from inception to 23 July 2021.

STUDY SELECTION

Randomized controlled trials (RCTs) and prospective cohort studies reporting major bleeding among patients with a first unprovoked VTE who were to receive oral anticoagulation for a minimum of 6 additional months after completing at least 3 months of initial anticoagulant treatment.

DATA EXTRACTION

Two reviewers independently abstracted data and assessed study quality. Unpublished data required for analyses were obtained from authors of included studies.

DATA SYNTHESIS

Among the 14 RCTs and 13 cohort studies included in the analysis, 9982 patients received a vitamin K antagonist (VKA) and 7220 received a direct oral anticoagulant (DOAC). The incidence of major bleeding per 100 person-years was 1.74 events (95% CI, 1.34 to 2.20 events) with VKAs and 1.12 events (CI, 0.72 to 1.62 events) with DOACs. The 5-year cumulative incidence of major bleeding with VKAs was 6.3% (CI, 3.6% to 10.0%). Among patients receiving either a VKA or a DOAC, the incidence of major bleeding was statistically significantly higher among those who were older than 65 years or had creatinine clearance less than 50 mL/min, a history of bleeding, concomitant use of antiplatelet therapy, or a hemoglobin level less than 100 g/L. The case-fatality rate of major bleeding was 8.3% (CI, 5.1% to 12.2%) with VKAs and 9.7% (CI, 3.2% to 19.2%) with DOACs.

LIMITATION

Data were insufficient to estimate incidence of major bleeding beyond 1 year of extended anticoagulation with DOACs.

CONCLUSION

In patients with a first unprovoked VTE, the long-term risks and consequences of anticoagulant-related major bleeding are considerable. This information will help inform patient prognosis and guide decision making about treatment duration for unprovoked VTE.

PRIMARY FUNDING SOURCE

Canadian Institutes of Health Research. (PROSPERO: CRD42019128597).

Management and Outcomes of Isolated Distal Deep Vein Thromboses: A Questionable Trend toward Long-Lasting Anticoagulation Treatment. Results from the START-Register

Background  Isolated distal deep vein thromboses (IDDVT) are frequently diagnosed; however, their natural history and real risk of complications are still uncertain. Though treatment is still not well standardized, international guidelines recommend no more than 3 months of anticoagulation therapy. We investigated how Italian clinicians treat IDDVT patients in their real life in our country.

Methods  Baseline characteristics and clinical history of the patients enrolled in the prospective, observational, multicenter START-Register for a first IDDVT or proximal DVT (PDVT) were analyzed.

Results  Overall, 412 IDDVT patients were significantly younger, with better renal function, and more frequent major transient risk factors, when compared with 1,173 PDVT patients. The anticoagulation duration was >180 days in 52.7% of IDDVT patients (70.7% in PDVT). During treatment, bleeding occurred in 5.6 and 2.8% patient-years in IDDVT and PDVT, respectively ( p  = 0082). Bleeding was more frequent in IDDVT than PDVT patients treated with warfarin (6.8 vs. 3.2 patient-years, p  = 0.0228, respectively). Thrombotic complications occurred in 1.1 and 2.4% patient-years in IDDVT and PDVT patients, respectively. Analyzing together the two groups, 66.1% of bleeds and 86.1% thrombotic complications occurred after 90 days anticoagulation treatment.

Conclusion  The large majority of IDDVT patients received anticoagulation for more than 3 months. Most bleeding and thrombotic complications occurred after the first 90 days of anticoagulation therapy. These results indicate that an extended anticoagulation beyond 90 days in IDDVT patients is associated with increased risk of complications. Whether an extended treatment may lower recurrences after anticoagulation withdrawal should be assessed by specifically designed studies.

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.

[Tranexamic acid for bleeding prophylaxis in orthopedic surgery and trauma-standard or customized therapy?]

The use of tranexamic acid (TXA) is established in the treatment of bleeding, especially of bleeding due to hyperfibrinolysis. In recent years the prophylactic use of TXA in trauma and orthopedic surgery has increased leading to open questions regarding potentially associated risks and a possible classification as off label use. The available literature provides a sound basis for the recommendation that TXA can be used in these indications provided that an individual risk assessment is done in patients with increased risks for thromboembolic complications. Although the prophylactic use of TXA in orthopedic surgery and trauma is not explicitly listed in the product characteristics, it should not be regarded as an off label use.

Use of Glucocorticoids and Risk of Venous Thromboembolism: A Narrative Review

Glucocorticoids are potent anti-inflammatory agents that are widely used for the treatment of many inflammatory, autoimmune, and neoplastic disorders. However, their beneficial effect is associated with several side effects, including an increased risk of cardiovascular complications, such as myocardial infarction and stroke. Whether their use also contributes to a procoagulant state, and therefore increases the risk of venous thromboembolism (VTE), is still a matter of debate. As an increased risk of venous thrombotic events is described in patients with Cushing's syndrome, which is characterized by endogenous hypercortisolism, it is reasonable to speculate that the chronic administration of glucocorticoids may induce a hypercoagulable state. However, it seems virtually impossible to separate the role of the drug from the underlying condition, which itself predisposes to the development of VTE. Actually, some evidence suggests that the use of exogenous glucocorticoids for the treatment of underlying disease and its exacerbations may further amplify the risk of VTE. Moreover, a procoagulant state has also been reported in healthy participants receiving oral glucocorticoids versus placebo. We have performed a concise narrative review on available data on the influence of exogenous glucocorticoids on hemostasis and their clinical impact on the risk of VTE.

Xueshuantong Injection in Treating Deep Venous Thrombosis: A Systematic Review and Trial Sequential Analysis

AIMS

In recent years, the incidence of deep venous thrombosis (DVT) presents an increasing trend year by year. The current evidence regarding the efficacy and safety of Xueshuantong injection for DVT is controversial. This systematic review (SR) aimed to assess the efficacy and safety of Xueshuantong injection in the treatment of DVT systematically and provide an evidence-based reference for clinical treatment.

METHODS

Nine electronic databases were used to identify the literature consisting of randomized controlled trials (RCTs) with a date of search of 1 November 2020. Clinical effective rate and incidence rate of adverse events were investigated as primary outcomes. Patency rate of femoral vein, patency rate of popliteal vein, patency rate of posterior tibial vein, circumference difference, activated partial thromboplastin time (APTT), and D-dimer (D-D) were investigated as secondary outcomes. Revman 5.4.1 was used to analyze the results. Analysis of the power of evidence was performed with Trial Sequential Analysis (TSA).

RESULTS

A total of 12 articles including 1018 patients were included. The results of the meta-analysis showed that the clinical effective rate in the experimental group was higher than that in the control group, the incidence rate of adverse events in the experimental group was higher than that in the control group; after the operation, the patency rate of femoral vein, patency rate of popliteal vein, patency rate of posterior tibial vein, circumference difference, APTT, and D-D in the experimental group were significantly improved compared with those in the control group, and the difference between the groups was statistically significant. TSA suggested that the meta-analysis concerning the clinical effectiveness of Xueshuantong injection in the treatment of DVT was of adequate power to reach firm conclusions.

CONCLUSION

Based on the current analysis, Xueshuantong injection as an add-on treatment provided better treatment effect for DVT with adequate power but this benefit should be considered with caution because of the small number of studies included in the meta-analysis and the high or unclear risk of bias of the included trials, suggesting that further studies are needed.

Decision-Making in the Management of Venous Thromboembolism

Venous thromboembolism comprising deep venous thrombosis and pulmonary embolus is common. Patients with venous thromboembolism may present to a variety of health care providers, and while a significant proportion of patients begin treatment in the hospital, ambulatory management of both deep venous thrombosis and pulmonary embolus is feasible and becoming more common. Initial anticoagulant management, investigation of venous thromboembolism etiology, and decisions about extended anticoagulation require coordinated care by physicians from multiple specialties. Comprehensive management of venous thromboembolism requires coordinated care from the time of presentation in order to expedite diagnosis, initiate timely anticoagulant treatment, determine the need for extended anticoagulation based on risk of bleeding and recurrent thrombosis, and advise on thromboprophylaxis during future high-risk periods for venous thromboembolism. In this review we use case scenarios to provide an operational framework, based on current evidence-based recommendations, for informed decision-making about a number of clinical practice issues that are frequently encountered in the management of venous thromboembolism patients.

Individualised Risk Assessments for Recurrent Venous Thromboembolism: New Frontiers in the Era of Direct Oral Anticoagulants

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality and is associated with high recurrence rates. The introduction of direct oral anticoagulants (DOACs) in the 2010s has changed the landscape of VTE management. DOACs have become the preferred anticoagulant therapy for their ease of use, predictable pharmacokinetics, and improved safety profile. Increasingly, guidelines have recommended long term anticoagulation for some indications such as following first unprovoked major VTE, although an objective individualised risk assessment for VTE recurrence remains elusive. The balance of preventing VTE recurrence needs to be weighed against the not insignificant bleeding risk, which is cumulative with prolonged use. Hence, there is a need for an individualised, targeted approach for assessing the risk of VTE recurrence, especially in those patients in whom the balance between benefit and risk of long-term anticoagulation is not clear. Clinical factors alone do not provide the level of discrimination required on an individual level. Laboratory data from global coagulation assays and biomarkers may provide enhanced risk assessment ability and are an active area of research. A review of the prediction models and biomarkers for assessing VTE recurrence risk is provided, with an emphasis on contemporary developments in the era of DOACs and global coagulation assays.

Can we predict and prevent the postthrombotic syndrome?

Postthrombotic syndrome (PTS) remains one of the major late complications of deep vein thrombosis (DVT) with a reported prevalence from 10 to 50%. Many factors were found to be related with the development and severity of PTS such as ipsilateral recurrent DVT, advanced age, obesity, ilio-femoral DVT and primary chronic venous disease presence. Some PTS prediction models have been proposed based on risk factor weight. However, it is still difficult to predict which patient with DVT will develop PTS and thus, the clinical application of these models remains limited. Among the identified problems the heterogeneity of the DVT patient population together with the variety of PTS clinical presentations and difficulties concerning PTS severity assessment should be mentioned. Difficulties on the implementation of the specific and objective PTS identification method have also the significant influence on the research focusing on PTS prevention modalities including risk factor modification, compression treatment, anticoagulation and invasive DVT treatment. In this review, the current approach and knowledge on PTS prediction and prevention are presented, including the conservative and invasive DVT treatment possibilities.

Risk of venous thromboembolism in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune joint disease with persistent systemic inflammation. Patients with RA suffer from joint pain and physical disability, but have their prognosis mostly driven by cardiovascular events, including venous thromboembolism (VTE). The risk of VTE is more than double in patients with RA compared with the general population. The incidence rate in patients with RA is estimated around 4 cases per 1000 person-years. The etiology of thrombotic tendency in RA is linked to various mechanisms and causal factors (antiphsolpholid antibodies, hyperhomocyteinemia, inflammation…): vascular injury, hypercoagulation, and venous stasis, the three components of the Virchow's triad, are activated in patients with RA. In clinical practice, situations that put patients for VTE should be identified (e.g., surgery, first year after RA diagnosis, hospitalization for acute illness…). Patients with RA are exposed to reversible risk factors, such as major surgery (knee or hip surgery) or hospitalization with immobilization. Similarly, uncontrolled RA, which is defined by the necessity to switch a biological disease-modifying anti-rheumatic drugs (DMARD), increases the incidence of VTE in observational studies. Moreover, DMARDs may impact the risk of VTE, especially in the time window after first prescription. Several biological DMARDs like tofacitinib have been associated with an increased risk of VTE. Therefore, patients with RA may require specific measures in terms of VTE diagnosis and management. In this review, we provide current insights into the pathophysiology, epidemiology, clinical considerations, and treatment strategies of VTE highlighting gaps in evidence and perspectives in patients with RA.

Prediction and treatment of bleeding in patients under anticoagulant treatment

Major bleeding is a common complication of anticoagulant treatment. Risk assessment tools are relevant in the management of patients with atrial fibrillation and venous thromboembolism. The combination of clinical, biological and genetic markers is incorporated to build predictive scores to help in the decision process about intensity and duration of treatment. The optimal management of bleeding involves the application of predictive scores in combination with anticoagulant reversal strategies.