Six-week low-molecular-weight heparin versus 12-week warfarin for calf deep vein thrombosis: A randomized, prospective, open-label study.

Current guidelines suggest a 3-month anticoagulant treatment course for isolated distal deep vein thrombosis (IDDVT), but shorter durations of treatment are frequently prescribed in clinical practice. We investigated whether a 6-week treatment with low-molecular-weight heparin (LMWH) at intermediate dosage can be an effective and safe alternative to vitamin K antagonists (VKA) in patients with IDDVT (non-inferiority trial). In a multicenter, open-label, randomized trial, 260 outpatients with symptomatic IDDVT were randomly assigned to receive either LMWH followed by VKA for 12 weeks or LMWH 1 mg/kg subcutaneously twice a day for 2 weeks followed by 1 mg/kg subcutaneously once a day for 4 weeks. The follow-up was 6 months and the primary endpoint was the composite measure of recurrent venous thromboembolism (VTE) defined as: recurrence or extension of IDDVT, proximal DVT, and pulmonary embolism (PE). The study was stopped prematurely due to slow recruiting rates. The primary efficacy outcome occurred in 14 patients receiving LMWH (10.8%) and in five patients receiving VKA (3.8%); risk difference was 0.069 (95% CI: 0.006-0.132), hazard ratio 2.8 (95% CI: 1.04-7.55). There was one PE in the VKA group and one proximal DVT in the LMWH group. IDDVT recurrence was 10.0% in the LMWH group versus 3.1% in the VKA group (p = .024). Two patients had clinically relevant bleedings (1.6%) in the LMWH group versus one (0.8%) in VKA group (p = .56). In conclusion, VKA for 12 weeks seems superior to LMWH for 6 weeks in reducing the risk of VTE recurrences in our cohort of outpatients with IDDVT.

Incidence and predictors of post-thrombotic syndrome in patients with proximal DVT in a real-world setting: findings from the GARFIELD-VTE registry.

Although substantial progress has been made in the pathophysiology and management of the post-thrombotic syndrome (PTS), several aspects still need clarification. Among them, the incidence and severity of PTS in the real world, the risk factors for its development, the value of patient's self-evaluation, and the ability to identify patients at risk for severe PTS. Eligible participants (n = 1107) with proximal deep-vein thrombosis (DVT) from the global GARFIELD-VTE registry underwent conventional physician's evaluation for PTS 36 months after diagnosis of their DVT using the Villalta score. In addition, 856 patients completed a Villalta questionnaire at 24 months. Variable selection was performed using stepwise algorithm, and predictors of severe PTS were incorporated into a multivariable risk model. The optimistic adjusted c-index was calculated using bootstrapping techniques. Over 36-months, 27.8% of patients developed incident PTS (mild in 18.7%, moderate in 5.7%, severe in 3.4%). Patients with incident PTS were older, had a lower prevalence of transient risk factors of DVT and a higher prevalence of persistent risk factors of DVT. Self-assessment of overall PTS at 24 months showed an agreement of 63.4% with respect to physician's evaluations at 36 months. The severe PTS multivariable model provided an optimistic adjusted c-index of 0.68 (95% CI 0.59-0.77). Approximately a quarter of DVT patients experienced PTS over 36 months after VTE diagnosis. Patient's self-assessment after 24 months provided added value for estimating incident PTS over 36 months. Multivariable risk analysis allowed good discrimination for severe PTS.

The clinical application of venous ultrasound in diagnosis and follow-up of lower extremity deep vein thrombosis (DVT): a case-based discussion.

Current clinical practice guidelines lack explicit guidance on the indications and appropriate timing of venous ultrasound (US) in lower extremity deep vein thrombosis (DVT) follow-up. Moreover, abnormal findings reported on venous US in DVT follow-up or suspected recurrent DVT may be difficult for clinicians to interpret, which carries risk of harm from inappropriate use of anti- coagulation and increased healthcare resource utilization. Due to the above factors, over-use of ultrasound in diagnosis and follow-up of lower extremity DVT has been reported in western health systems. We have undertaken a case-based discussion and a scoping review of existing guidelines on the use of venousUS following prior diagnosis of DVT, to guide appropriate interpretation of commonly reported US abnormalities and provide our suggestions in the light of best available evidence on appropriate timing to perform follow-up US in management of lower extremity DVT.

Common Practice in the Treatment of Superficial Vein Thrombosis Involving the Sapheno-Femoral Junction: Results from a National Survey of the Italian Society of Angiology and Vascular Medicine (SIAPAV).

Background and Objectives: Prophylactic doses of low-molecular-weight heparins or fondaparinux showed their efficacy and safety for treatment of all superficial vein thrombosis (SVT) of the lower limbs, yet not for those extended to the last 3 cm of the great saphenous vein, close to the sapheno-femoral junction, or considered as a deep-vein thrombosis. Some experts suggest that these patients should be managed with full anticoagulant doses but evidence to support this recommendation is lacking, suggesting the need for a properly designed trial. Materials and Methods: Before starting a new trial, the Italian Society of Angiology and Vascular Medicine (SIAPAV) decided to verify the common therapeutic approaches for patients with an SVT in Italian vascular centers based on a hypothetical significant variation in each daily clinical practice. A standardized questionnaire of 10 questions was administered to all SIAPAV affiliates by means of the official Society website. Results: From 1 December 2022 to 20 January 2023 a total of 191 members (31.8%) answered the questionnaire, showing a detailed and a substantial heterogeneity in the therapeutic approach to SVT patients among experienced vascular physicians and angiologists. Detailed results are reported in the relative section. Conclusions: The therapeutic approach of SVT extended to the iuxta-femoral segment of the great saphenous vein is still a matter of debate, and data to support therapeutic strategies are lacking. The wide heterogeneity in the management of SVT patients, including those with more extended thrombosis, confirmed that a randomized controlled clinical trial investigating the efficacy and the safety of a tailored therapeutic regimen in this particular subgroup of patients is strongly warranted.

Evolving Knowledge on Primary and Secondary Prevention of Venous Thromboembolism in Carriers of Hereditary Thrombophilia: A Narrative Review.

The association between heritability of venous thromboembolism (VTE) and thrombophilia was first reported clinically in 1956, later followed by the first description of a congenital cause of hypercoagulability-antithrombin deficiency-in 1965. Since then, our knowledge of hereditary causes of hypercoagulability, which may predispose carriers to VTE has improved greatly. Novel genetic defects responsible for severe thrombophilia have been recently identified and we have learned that a wide range of interactions between thrombophilia and other genetic and acquired risk factors are important determinants of the overall individual risk of developing VTE. Furthermore, therapeutic strategies in thrombophilic patients have benefited significantly from the introduction of direct oral anticoagulants. The present review is an overview of the current knowledge on the mechanisms underlying inherited thrombophilia, with a particular focus on the latest achievements in anticoagulation protocols and prevention strategies for thrombosis in carriers of this prothrombotic condition.

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).

Venous Thromboembolism in Cancer Patients Undergoing Chemotherapy: Risk Factors and Prevention.

Ambulatory cancer patients undergoing chemotherapy are at a substantial risk for venous thromboembolism (VTE) over the course of therapy and beyond it. Factors accounting for this risk include the activation of extrinsic and intrinsic coagulation pathways, platelet activation, impaired fibrinolysis, use of catheters, infusion of blood products, and thrombogenic potential of several chemotherapeutic drugs. A few stratification models can help identify patients at a higher risk of chemotherapy-associated VTE, who may benefit from preventive strategies. Although low-molecular-weight heparins (LMWHs) effectively reduce the risk of VTE, current guidelines recommend against their routine use. Based on the results of recent randomized controlled clinical trials, the administration of prophylactic doses of the novel direct oral anticoagulants (DOACs) to ambulatory cancer patients undergoing chemotherapy has the potential to offer an effective and safe protection against VTE, obviating the inconveniences of heparins. Except for patients in whom the novel drugs are unsuitable or are contraindicated, in all other patients LMWHs should be replaced by low-dose DOACs.

Post-thrombotic syndrome.

Post-thrombotic syndrome (PTS) is a chronic venous insufficiency manifestation following an episode of deep-vein thrombosis (DVT). It is an important and frequent long-term adverse event of proximal DVT affecting 20-50% of patients. This position paper integrates data guiding clinicians in deciding PTS diagnosis, treatment and follow-up.

Rivaroxaban or Aspirin for Extended Treatment of Venous Thromboembolism.

BACKGROUND: Although many patients with venous thromboembolism require extended treatment, it is uncertain whether it is better to use full- or lower-intensity anticoagulation therapy or aspirin. METHODS: In this randomized, double-blind, phase 3 study, we assigned 3396 patients with venous thromboembolism to receive either once-daily rivaroxaban (at doses of 20 mg or 10 mg) or 100 mg of aspirin. All the study patients had completed 6 to 12 months of anticoagulation therapy and were in equipoise regarding the need for continued anticoagulation. Study drugs were administered for up to 12 months. The primary efficacy outcome was symptomatic recurrent fatal or nonfatal venous thromboembolism, and the principal safety outcome was major bleeding. RESULTS: A total of 3365 patients were included in the intention-to-treat analyses (median treatment duration, 351 days). The primary efficacy outcome occurred in 17 of 1107 patients (1.5%) receiving 20 mg of rivaroxaban and in 13 of 1127 patients (1.2%) receiving 10 mg of rivaroxaban, as compared with 50 of 1131 patients (4.4%) receiving aspirin (hazard ratio for 20 mg of rivaroxaban vs. aspirin, 0.34; 95% confidence interval [CI], 0.20 to 0.59; hazard ratio for 10 mg of rivaroxaban vs. aspirin, 0.26; 95% CI, 0.14 to 0.47; P<0.001 for both comparisons). Rates of major bleeding were 0.5% in the group receiving 20 mg of rivaroxaban, 0.4% in the group receiving 10 mg of rivaroxaban, and 0.3% in the aspirin group; the rates of clinically relevant nonmajor bleeding were 2.7%, 2.0%, and 1.8%, respectively. The incidence of adverse events was similar in all three groups. CONCLUSIONS: Among patients with venous thromboembolism in equipoise for continued anticoagulation, the risk of a recurrent event was significantly lower with rivaroxaban at either a treatment dose (20 mg) or a prophylactic dose (10 mg) than with aspirin, without a significant increase in bleeding rates. (Funded by Bayer Pharmaceuticals; EINSTEIN CHOICE ClinicalTrials.gov number, NCT02064439 .).

Cancer associated thrombosis in everyday practice: perspectives from GARFIELD-VTE.

Venous thromboembolism (VTE) is common in cancer patients and is an important cause of morbidity and mortality. The Global Anticoagulant Registry in the FIELD (GARFIELD)-VTE (ClinicalTrials.gov: NCT02155491) is a prospective, observational study of 10,684 patients with objectively diagnosed VTE from 415 sites in 28 countries. We compared baseline characteristics, VTE treatment patterns, and 1-year outcomes (mortality, recurrent VTE and major bleeding) in 1075 patients with active cancer, 674 patients with a history of cancer, and 8935 patients without cancer. Patients with active cancer and history of cancer were older than cancer-free patients, with median ages of 64.8, 68.9, and 58.4 years, respectively. The most common sites of active cancer were lung (14.5%), colorectal (11.0%), breast (10.6%), and gynaecological (10.3%). Active cancer patients had a higher incidence of upper limb and vena cava thrombosis than cancer-free patients (9.0% vs 4.8% and 5.1% vs 1.4%, respectively), and were more likely to receive parenteral anticoagulation as monotherapy than cancer-free patients (57.8% vs 12.1%), and less likely to receive DOACs (14.2% vs 50.6%). Rates of death, recurrent VTE, and major bleeding were higher in active cancer patients than in cancer-free patients, with hazard ratios (95% confidence intervals) of 14.2 (12.1-16.6), 1.6 (1.2-2.0) and 3.8 (2.9-5.0), respectively. VTE was the second most common cause of death in patients with active cancer or history of cancer. In patients with VTE, those with active cancer are at higher risk of death, recurrence, and major bleeding than those without cancer.

Prevalence of Pulmonary Embolism among Patients Hospitalized for Syncope.

BACKGROUND: The prevalence of pulmonary embolism among patients hospitalized for syncope is not well documented, and current guidelines pay little attention to a diagnostic workup for pulmonary embolism in these patients. METHODS: We performed a systematic workup for pulmonary embolism in patients admitted to 11 hospitals in Italy for a first episode of syncope, regardless of whether there were alternative explanations for the syncope. The diagnosis of pulmonary embolism was ruled out in patients who had a low pretest clinical probability, which was defined according to the Wells score, in combination with a negative d-dimer assay. In all other patients, computed tomographic pulmonary angiography or ventilation-perfusion lung scanning was performed. RESULTS: A total of 560 patients (mean age, 76 years) were included in the study. A diagnosis of pulmonary embolism was ruled out in 330 of the 560 patients (58.9%) on the basis of the combination of a low pretest clinical probability of pulmonary embolism and negative d-dimer assay. Among the remaining 230 patients, pulmonary embolism was identified in 97 (42.2%). In the entire cohort, the prevalence of pulmonary embolism was 17.3% (95% confidence interval, 14.2 to 20.5). Evidence of an embolus in a main pulmonary or lobar artery or evidence of perfusion defects larger than 25% of the total area of both lungs was found in 61 patients. Pulmonary embolism was identified in 45 of the 355 patients (12.7%) who had an alternative explanation for syncope and in 52 of the 205 patients (25.4%) who did not. CONCLUSIONS: Pulmonary embolism was identified in nearly one of every six patients hospitalized for a first episode of syncope. (Funded by the University of Padua; PESIT ClinicalTrials.gov number, NCT01797289 .).

Screening for Occult Cancer in Patients With Unprovoked Venous Thromboembolism: A Systematic Review and Meta-analysis of Individual Patient Data.

BACKGROUND: Screening for cancer in patients with unprovoked venous thromboembolism (VTE) often is considered, but clinicians need precise data on cancer prevalence, risk factors, and the effect of different types of screening strategies. PURPOSE: To estimate the prevalence of occult cancer in patients with unprovoked VTE, including in subgroups of different ages or those that have had different types of screening. DATA SOURCES: MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials up to 19 January 2016. STUDY SELECTION: Prospective studies evaluating cancer screening strategies in adults with unprovoked VTE that began enrolling patients after 1 January 2000 and had at least 12 months of follow-up. DATA EXTRACTION: 2 investigators independently reviewed abstracts and full-text articles and independently assessed risk of bias. DATA SYNTHESIS: 10 eligible studies were identified. Individual data were obtained for all 2316 patients. Mean age was 60 years; 58% of patients received extensive screening. The 12-month period prevalence of cancer after VTE diagnosis was 5.2% (95% CI, 4.1% to 6.5%). The point prevalence of cancer was higher in patients who had extensive screening than in those who had more limited screening initially (odds ratio [OR], 2.0 [CI, 1.2 to 3.4]) but not at 12 months (OR, 1.4 [CI, 0.89 to 2.1]). Cancer prevalence increased linearly with age and was 7-fold higher in patients aged 50 years or older than in younger patients (OR, 7.1 [CI, 3.1 to 16]). LIMITATION: Variation in patient characteristics and extensive screening strategies; unavailability of long-term mortality data. CONCLUSION: Occult cancer is detected in 1 in 20 patients within a year of receiving a diagnosis of unprovoked VTE. Older age is associated with a higher cancer prevalence. Although an extensive screening strategy initially may detect more cancer cases than limited screening, whether this translates into improved patient outcomes remains unclear. PRIMARY FUNDING SOURCE: None. (PROSPERO: CRD42016033371).

Impact of residual pulmonary obstruction on the long-term outcome of patients with pulmonary embolism.

The impact of residual pulmonary obstruction on the outcome of patients with pulmonary embolism is uncertain.We recruited 647 consecutive symptomatic patients with a first episode of pulmonary embolism, with or without concomitant deep venous thrombosis. They received conventional anticoagulation, were assessed for residual pulmonary obstruction through perfusion lung scanning after 6 months and then were followed up for up to 3 years. Recurrent venous thromboembolism and chronic thromboembolic pulmonary hypertension were assessed according to widely accepted criteria.Residual pulmonary obstruction was detected in 324 patients (50.1%, 95% CI 46.2-54.0%). Patients with residual pulmonary obstruction were more likely to be older and to have an unprovoked episode. After a 3-year follow-up, recurrent venous thromboembolism and/or chronic thromboembolic pulmonary hypertension developed in 34 out of the 324 patients (10.5%) with residual pulmonary obstruction and in 15 out of the 323 patients (4.6%) without residual pulmonary obstruction, leading to an adjusted hazard ratio of 2.26 (95% CI 1.23-4.16).Residual pulmonary obstruction, as detected with perfusion lung scanning at 6 months after a first episode of pulmonary embolism, is an independent predictor of recurrent venous thromboembolism and/or chronic thromboembolic pulmonary hypertension.

Scoring Systems for Estimating Risk of Venous Thromboembolism in Hospitalized Medical Patients.

Deep vein thrombosis and pulmonary embolism are associated with considerable morbidity and mortality in hospitalized patients, accounting for up to 10% of hospitalization-related deaths in both surgical and medical patients. Pharmacologic thromboprophylaxis has been demonstrated to be effective, safe, and cost-effective in preventing hospital-acquired venous thromboembolism (VTE) among medical inpatients, and clinician awareness of thrombotic risk promotes prescription of thromboprophylaxis. Guidelines recommend stratification of thrombotic risk for all patients and, unless contraindicated, administration of VTE prophylaxis. Based on several recognized predisposing and exposing risk factors for VTE, several scoring systems have been published in the past 15 years. Borrowing models developed in the surgical setting, recognized risk factors for VTE complications in medical inpatients have been combined in different weighted scores and derived and validated in heterogeneous medical populations. Although the perfect score, balancing thrombotic and hemorrhagic risk, has probably not yet been built, the adoption of an easy-to-use risk assessment model has the potential to support physicians in properly stratifying VTE risk in medical inpatients, tailoring thromboprophylaxis prescription.

Venous and Arterial Thrombosis: Is There a Link?

An increasing body of evidence suggests the likelihood of a link between venous and arterial thrombosis. The two vascular complications share several risk factors, such as age, obesity, smoking, diabetes mellitus, blood hypertension, hypertriglyceridemia, and metabolic syndrome. Moreover, there are many examples of conditions accounting for both venous and arterial thrombosis, such as the antiphospholipid antibody syndrome, hyperhomocysteinemia, malignancies, infections, and the use of hormonal treatment. Finally, several recent studies have consistently shown that patients with venous thromboembolism are at a higher risk of arterial thrombotic complications than matched control individuals. We, therefore, speculate the two vascular complications are simultaneously triggered by biological stimuli responsible for activating coagulation and inflammatory pathways in both the arterial and the venous system. Future studies are needed to clarify the nature of this association, to assess its extent, and to evaluate its implications for clinical practice.