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Background: The long-term risk for recurrent venous thromboembolism (VTE) during extended anticoagulation for a first unprovoked VTE is uncertain. Objectives: To determine the incidence of recurrent VTE during extended anticoagulation of up to 5years in patients with a first unprovoked VTE. Methods: MEDLINE, EMBASE, and the Cochrane CENTRAL were searched to identify randomized trials and prospective cohort studies reporting recurrent VTE among patients with a first unprovoked VTE who were to receive anticoagulation for a minimum of six additional months after completing ≥3months of initial treatment. Unpublished data on number of recurrent VTE and person-years, obtained from authors of included studies, were used to calculate study-level incidence rate, and random-effects meta-analysis was used to pool results. Results: Twenty-six studies and 15603 patients were included in the analysis. During 11631 person-years of follow-up, the incidence of recurrent VTE and fatal pulmonary embolism per 100 person-years was 1.41 (95% CI, 1.03–1.84) and 0.09 (0.04–0.16), with 5-year cumulative incidences of 7.1% (3.0%–13.2%) and 1.2% (0.4%–4.6%), respectively. The incidence of recurrent VTE was 1.08 (95% CI, 0.77–1.44) with direct oral anticoagulants and 1.55 (1.01–2.20) with vitamin K antagonists. The case-fatality rate of recurrent VTE was 4.9% (95% CI, 2.2%–8.7%). Conclusions: In patients with a first unprovoked VTE, the long-term risk of recurrent VTE during extended anticoagulation is low but not negligible. Thus, clinicians and patients should be aware of this risk and take appropriate and timely action in case of suspicion of recurrent VTE. Estimates from this study can be used to advise patients on what to expect while receiving extended anticoagulation, and estimate the net clinical benefit of extended treatment to guide long-term management of unprovoked VTE. © 2021 International Society on Thrombosis and Haemostasis.

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).

BACKGROUND: Randomised control trials have assessed the efficacy and safety of direct oral anticoagulants in the prophylaxis and treatment of venous thromboembolism (VTE). Positive but limited results have been reported in patients with inherited thrombophilia. Using an Italian, multicentre, prospective registry of consecutive patients presenting with symptomatic, acute VTE, we aimed to assess which factors are involved in making the choice of the drug that best fits the patient's risk profile in a large real-world setting of VTE patients. MATERIALS AND METHODS: We investigated 4,866 VTE patients who took oral anticoagulants in the period between 2012 and April 2018 to prevent a new thromboembolic episode. RESULTS: The large majority of patients who underwent thrombophilic screening, regardless of the results obtained, were prescribed direct oral anticoagulants rather than conventional anticoagulant therapy (p

Background Thrombocytopenia is associated with increased mortality in the general population, but few data exist in patients with atrial fibrillation ( AF ) taking oral anticoagulants. We investigated factor determinants of thrombocytopenia in a large cohort of patients affected by AF and its association with total mortality. Methods and Results Multicenter prospective cohort study, including 5215 patients with AF from the START (Survey on Anticoagulated Patients Register) registry, 3877 (74.3%) and 1338 (25.7%) on vitamin K or non–vitamin K antagonist oral anticoagulants, respectively. Thrombocytopenia was defined by a platelet count 9 /L. Determinants of thrombocytopenia were investigated, and all‐cause mortality was the primary survival end point of the study. Thrombocytopenia was present in 592 patients (11.4%). At multivariable logistic regression analysis, chronic kidney disease (odds ratio [ OR], 1.257; P =0.030), active cancer ( OR, 2.065; P =0.001), liver cirrhosis ( OR, 7.635; P OR, 1.234; P =0.046) were positively associated with thrombocytopenia, whereas female sex ( OR, 0.387; P OR, 0.787; P =0.032) were negatively associated. During a median follow‐up of 19.2 months (9942 patient‐years), 391 deaths occurred (rate, 3.93%/year). Mortality rate increased from 3.8%/year to 9.9%/year in patients with normal platelet count and in those with moderate‐severe thrombocytopenia, respectively (log‐rank test, P =0.009). The association between moderate‐severe thrombocytopenia and mortality persisted after adjustment for CHA 2 DS 2 VAS c score (hazard ratio, 2.431; 95% CI, 1.254–4.713; P =0.009), but not in the fully adjusted multivariable Cox regression analysis model. Conclusions Thrombocytopenia is common in patients with AF . Despite an increased incidence of mortality, thrombocytopenia was not associated with mortality at multivariable analysis. Thrombocytopenia may reflect the presence of comorbidities associated with poor survival in AF .

Although below-knee compression elastic stockings (CES) are effective for the prevention of the postthrombotic syndrome (PTS), a substantial number of patients with deep venous thrombosis still develop PTS. In the present open-label, randomized clinical trial, we compared thigh-length with below-knee CES for the prevention of PTS. A total of 267 patients with the first episode of proximal deep venous thrombosis were randomized to wear either thigh-length or below-knee CES for 2 years. After 3, 6, 12, 18, 24, and 36 months, they were assessed for PTS manifestations according to the Villalta scale. PTS developed in 44 (32.6%) of the 135 patients randomized to thigh-length CES and in 47 (35.6%) of the 132 allocated to below-knee CES, for an adjusted hazard ratio of 0.93 (95% confidence interval, 0.62-1.41). Severe PTS developed in 3 patients in each group. CES-related side effects developed in 55 (40.7%) of the 135 patients allocated to thigh-length CES and in 36 (27.3%) of those randomized to the below-knee group (P = .017), and led to premature discontinuation of their use in 29 (21.5%) and 18 (13.6%) patients, respectively. We conclude that thigh-length CES do not offer a better protection against PTS than below-knee CES and are less well tolerated. This study is registered as Clinical Trial number NCT00426075.

Immobility is a well-recognized risk factor for deep vein thrombosis (DVT) in surgical patients, whereas the level of DVT risk conferred by immobility is less defined in patients on medical wards. The aim of this study was to establish whether immobility and its duration are associated with the risk of DVT in acutely ill medical inpatients. We conducted a cohort study in acutely ill medical inpatients. Patients underwent whole leg ultrasound for suspected lower extremity DVT and were divided into two groups according to presence or absence of immobility, defined as total bed rest or sedentary without bathroom privileges. The endpoint was the detection of proximal DVT or isolated distal DVT (IDDVT). Among the 252 acutely ill medical inpatients with immobility (age 82.6 ± 10.3 years, female 63.9%), ultrasound showed 36 (14.3%) proximal DVTs and 39 (15.5%) IDDVTs, while there were 11 (4.4%) proximal DVTs and 26 (10.5%) IDDVTs among the 248 inpatients without immobility (age 73.6 ± 14.2 years, female 54.8%). The risk of proximal DVT was higher in immobile than in mobile patients (OR 3.59, 95% CI: 1.78–7.23, p = 0.0001), whereas the risk of IDDVT was similar between the two groups (OR 1.56, 95% CI: 0.92–2.66, p = 0.111). During the first 3 days of hospitalization, the frequency of all DVTs was similar in patients with and without immobility, but it was 0.26 ± 0.03 vs 0.18 ± 0.03, respectively, after 4 days. In conclusion, immobility for more than 3 days is a risk factor for proximal DVT in acutely ill medical inpatients. © The Author(s) 2021.

Cancer and COVID-19 are both well-established risk factors predisposing to thrombosis. Both disease entities are correlated with increased incidence of venous thrombotic events through multifaceted pathogenic mechanisms involving the interaction of cancer cells or SARS-CoV2 on the one hand and the coagulation system and endothelial cells on the other hand. Thromboprophylaxis is recommended for hospitalized patients with active cancer and high-risk outpatients with cancer receiving anticancer treatment. Universal thromboprophylaxis with a high prophylactic dose of low molecular weight heparins (LMWH) or therapeutic dose in select patients, is currentlyindicated for hospitalized patients with COVID-19. Also, prophylactic anticoagulation is recommended for outpatients with COVID-19 at high risk for thrombosis or disease worsening. However, whether there is an additive risk of thrombosis when a patient with cancer is infected with SARS-CoV2 remains unclear In the current review, we summarize and critically discuss the literature regarding the epidemiology of thrombotic events in patients with cancer and concomitant COVID-19, the thrombotic risk assessment, and the recommendations on thromboprophylaxis for this subgroup of patients. Current data do not support an additive thrombotic risk for patients with cancer and COVID-19. Of note, patients with cancer have less access to intensive care unit care, a setting associated with high thrombotic risk. Based on current evidence, patients with cancer and COVID-19 should be assessed with well-established risk assessment models for medically ill patients and receive thromboprophylaxis, preferentially with LMWH, according to existing recommendations. Prospective trials on well-characterized populations do not exist.

A current goal of the Italian Society for Thrombosis and Haemostasis (SISET) is the production of guidelines for clinical conditions related to haemostasis and thrombosis. In 2006, the Executive Committee of SISET adopted a new program for the production of methodologically and scientifically sound guidelines aimed at both addressing clinical practice and stimulating new research. The first major step for this program was to train methodologists to manage working groups that compose the guidelines, and to create a reference document that describes the development of the program. The aim of the present paper is to report a short version of this methodological document, for those who wish to follow SISET guidelines. We start by giving a brief outline of the SISET mission, then present the SISET guideline development process, which includes: project funding, selection of guidelines topics, multidisciplinary group composition, definition of clinical questions, literature search, evidence appraisal, grading recommendations, guideline implementation, external peer review, and guideline updating.

ImportanceThe post-thrombotic syndrome (PTS) is the most common long-term complication of deep vein thrombosis (DVT), occurring in up to 40–50% of cases. There are limited evidence-based approaches for PTS clinical management.ObjectiveTo provide an expert consensus for PTS diagnosis, prevention, and treatment.Evidence-ReviewMEDLINE, Cochrane Database review, and GOOGLE SCHOLAR were searched with the terms “post-thrombotic syndrome” and “post-phlebitic syndrome” used in titles and abstracts up to September 2020.Filters WereEnglish, Controlled Clinical Trial / Systematic Review / Meta-Analysis / Guideline. The relevant literature regarding PTS diagnosis, prevention and treatment was reviewed and summarized by the evidence synthesis team. On the basis of this review, a panel of 15 practicing angiology/vascular medicine specialists assessed the appropriateness of several items regarding PTS management on a Likert-9 point scale, according to the RAND/UCLA method, with a two-round modified Delphi method.FindingsThe panelists rated the following as appropriate for diagnosis: 1-the Villalta scale; 2- pre-existing venous insufficiency evaluation; 3-assessment 3–6 months after diagnosis of iliofemoral or femoro-popliteal DVT, and afterwards periodically, according to a personalized schedule depending on the presence or absence of clinically relevant PTS. The items rated as appropriate for symptom relief and prevention were: 1- graduated compression stockings (GCS) or elastic bandages for symptomatic relief in acute DVT, either iliofemoral, popliteal or calf; 2-thigh-length GCS (30–40 mmHg at the ankle) after ilio-femoral DVT; 3- knee-length GCS (30–40 mmHg at the ankle) after popliteal DVT; 4-GCS for different length of times according to the severity of periodically assessed PTS; 5-catheter-directed thrombolysis, with or without mechanical thrombectomy, in patients with iliofemoral obstruction, severe symptoms, and low risk of bleeding. The items rated as appropriate for treatment were: 1- thigh-length GCS (30–40 mmHg at the ankle) after iliofemoral DVT; 2-compression therapy for ulcer treatment; 3- exercise training. The role of endovascular treatment (angioplasty and/or stenting) was rated as uncertain, but it could be considered for severe PTS only in case of stenosis or occlusion above the inguinal ligament, followed by oral anticoagulation.Conclusions and RelevanceThis position paper can help practicing clinicians in PTS management.

Background - Even though it rarely influences venous thromboembolism (VTE) treatment and the fact that it is generally discouraged, thrombophilia testing is still largely prescribed. We assessed: 1) whether/how frequently Italian thrombosis centres requested thrombophilia testing; 2) what results were obtained; and 3) if the results affected treatment and clinical results. Materials and methods - We examined data from 4,826 VTE patients enrolled by 19 clinical centres participating in the START 2-Register. Results - 57.2% of patients were tested. Numbers varied widely among centres (2.9-99.7%). Thrombophilic alterations were recorded in 18.2% of patients and the percentage of positive results was inversely correlated with that of patients tested. Significantly less patients with deep vein thrombosis (DVT) were tested, whereas more were tested when the event was idiopathic, presenting as isolated pulmonary embolism (PE), or in unusual sites. Patients with thrombophilic alterations were younger, more frequently treated with direct oral anticoagulants (DOACs), with lower mortality and less frequently discontinued anticoagulation. DOACs were more frequently prescribed in patients with heterozygous Factor V (FV) Leiden or prothrombin mutations, whereas vitamin K antagonists were preferred in patients with inhibitor deficiencies, combined alterations or antiphospholipid syndrome (APLS). There was no difference in duration of treatment among those with or without alterations, though more APLS patients received an extended treatment course. Bleeding and thrombotic complications occurred with a similar and fairly low incidence in patients with or without thrombophilic alterations. Discussion - Although general testing for thrombophilia in VTE patients is currently discouraged, more than half of the VTE patients included in the START2-Register were tested. However, there were marked differences in practice between Italian thrombosis centres. About 60% of all patients with alterations were treated with DOACs, confirming that DOACs can be a useful option for treatment of thrombophilic VTE patients, with the exclusion of those with APLS. IMTIPRO Sr © SIMTIPRO Srl

Background: Few data are available on long-term atherothrombotic events after percutaneous transluminal angioplasty (PTA) for peripheral arterial disease (PAD). Restenosis after PTA may be a marker of a more aggressive atherothrombosis. Aim: To ascertain whether restenosis detected by duplex sonography (DUS) after PTA for iliac and femoro-popliteal disease is associated with a higher risk of cardiovascular events. Methods: We conducted a prospective cohort study of patients undergoing iliac or femoro-popliteal PTA for PAD. Patients were seen at one month, six months, one year and every year thereafter after PTA. At each visit, DUS was performed and accordingly restenosis was stratified into two categories (absent/present). The outcome was the composite of major adverse cardiovascular events (MACE). Results: Two hundred and fifty patients (aged 69 ± 11 years, male 59.2%) were enrolled. During a mean follow-up of 1207 ± 904 days, 102 (40.8%) patients developed restenosis. Restenosis was more frequent in patients with diabetes and critical limb ischaemia. MACEs (n = 76) were more frequent in the patients that developed restenosis vs. those that did not (40.2 vs. 23.6%, p =.005). Predictors of MACEs were diabetes (HR 2.02, 95%CI: 1.19–3.41, p =.009), presence of coronary heart disease at enrolment (HR 2.84, 95%CI: 1.78–4.53, p =.001) and restenosis (HR 1.87, 95%CI: 1.16–3.00, p =.010). Conclusion: Restenosis at DUS, diabetes, and coronary heart disease in patients who underwent iliac or femoro-popliteal PTA for PAD are associated with increased risk of arterial thrombotic event. Intervention trials are required to show the benefit of different therapeutic approaches in such patients at high risk of clinical deterioration.

Introduction: Co-administration of enoxaparin and a direct oral factor Xa inhibitor (xabans: apixaban, edoxaban, rivaroxaban) could give rise to the problem of overlapping the anti-Xa activity when measuring direct oral anticoagulant (DOAC) levels. We aimed to evaluate in vitro the degree of the interference of increasing enoxaparin concentrations on xaban plasma levels measured by different chromogenic anti-Xa assays with drug-specific calibrators and controls. Methods: Seven plasma samples were spiked with apixaban, edoxaban, or rivaroxaban at fixed concentration, and enoxaparin at increasing concentrations (0, 0.125, 0.250, 0.50, 1.0, 1.50, and 2.0IU/mL). The evaluated chromogenic assays were as follows: Biophen DiXaI and Biophen Heparin LRT (Hyphen BioMed), Berichrom Heparin and Innovance Heparin (Siemens), STA-Liquid Anti-Xa (Stago Diagnostics), Technochrom anti-Xa (Technoclone), and HemosIL Liquid Anti-Xa (Werfen). Results: The presence of enoxaparin caused increased DOAC levels, with over-estimation depending on the anti-Xa assay and on the heparin concentration in the sample. The smallest over-estimation was in the sample with enoxaparin 0.125IU/mL and the greatest in the sample with enoxaparin 2.0IU/mL (0%, 3.1%, and 7.4% vs 583.8%, 526.1%, and 415.2% for apixaban, edoxaban, and rivaroxaban, respectively). Biophen DiXaI showed lower interference compared to other methods (maximum over-estimation in the presence of enoxaparin 2.0IU/mL: 56.4% dosing rivaroxaban by Biophen DIXaI vs 583.8% dosing apixaban by Berichrom Heparin). Conclusion: The presence of enoxaparin interferes with xabans measurement by chromogenic anti-Xa assays causing falsely elevated DOAC levels, the over-estimation being dependent on the anti-Xa assay and on the heparin concentration in the sample.

Heparin-induced thrombocytopenia (HIT) has not been included as a possible cause of thrombocytopenia in Coronavirus Disease 2019 (COVID-19) patients. We report a case of HIT in a patient with COVID-19 treated with heparin. A 78-year-old man was admitted to our hospital for acute respiratory failure and acute renal failure due to SARS-CoV-2 infection; in intensive care unit, one 5000IU heparin dose (day 0, platelet count 305000/μL). On day 2, haemoglobin started to decrease and heparin was stopped. On day 10, platelet count was 153000/μL and 5000IU calcium heparin subcutaneously twice daily was started. The platelet further decreased, reaching 49000/μL on day 17, and the patient was investigated for suspected HIT: an IgG specific chemiluminescence test for heparin-PF4 antibodies was positive and a femoral DVT was found at ultrasound. Argatroban was started, platelet count increased without any bleeding and thrombosis complication. Our experience shows that HIT may develop in heparin treated COVID-19 patients and should be included among the possible cause of thrombocytopenia in such patients. © the Author(s), 2021.

Background: Venous thromboembolism (VTE) is a frequent and serious disease that requires immediate and long-term anticoagulant treatment, which is inevitably associated with a risk of bleeding complications. Some studies, though not all, reported a higher risk of bleeding in female patients treated with either old anticoagulants [vitamin k antagonists (VKAs)] or recent anticoagulants [direct oral anticoagulants (DOACs)]. Furthermore, analyses of clinical trials reported an abnormal vaginal bleeding in women of reproductive age treated with DOACs. This study aimed at comparing the risk of bleeding in an inception cohort of VTE women and men included in a prospective observational registry. Methods: Baseline characteristics and bleeding events occurring during anticoagulation in patients of both sexes, included in the START-Register after a first VTE, were analyzed. Results: In all, 1298 women were compared with 1290 men. Women were older and more often had renal diseases; their index events were often provoked (often by hormonal contraception and pregnancy), and more frequently presented as isolated pulmonary embolism (PE). The rate of bleeding was similar in women (2.9% patient-years) and men (2.1% patient-years), though it was higher when uterine bleeds were included (3.5% patient-years, p = 0.0141). More bleeds occurred in VKA- than DOAC-treated patients (6.4% versus 2.6%, respectively; p = 0.0013). At multivariate analysis, age ⩾ 75 years was associated with higher prevalence of bleeds. Conclusion: The occurrence of bleeding was not different between women and men during anticoagulation after VTE. Only after inclusion of vaginal/uterine bleeds, the rate of bleeding was higher in women. The incidence of bleeding was higher in women treated with VKAs. Plain Language Summary The risk of bleeding in women anticoagulated for deep vein thrombosis or pulmonary embolism is not higher than that in men, except for vaginal bleeding Background: The occurrence of a venous thromboembolic event (VTE, including deep vein thrombosis and pulmonary embolism) necessarily requires a period of at least 3–6 months of treatment with anticoagulant drugs [either vitamin k antagonists (VKA) or, more recently, direct oral anticoagulants (DOACs)]. Anticoagulation therapy, however, is associated with a risk of bleeding that is influenced by several factors. Sex is one of these factors as some authors have hypothesized that women are at higher risk than men. Furthermore, some studies have recently found more vaginal bleeding in VTE women treated with a DOAC compared with those who received VKAs. Methods: The present study aimed to compare the frequency of bleeds occurring in women and in men who were treated with DOACs or VKAs for a first VTE event and followed in real-life conditions. Since the beginning of their anticoagulant treatment, the patients were included in a prospective, multicenter, observational registry (the START-Register), and bleeding events were recorded. Results: A total of 1298 women were compared with 1290 men. Women were older and more often were affected by renal diseases; their VTE events were often associated with risk factors (especially hormonal contraception and pregnancy) and presented as isolated pulmonary embolism. The rate of all bleeding events (including major, non-major but clinically relevant, and minor bleeds) was higher in women (3.5% patient-years) than in men (2.1% patient-years, p = 0.0141); however, the difference was no longer statistically significant after exclusion of uterine bleeds (2.9% patient years). More bleeding occurred in women receiving VKA as anticoagulant drug compared with those treated with a DOAC (6.4% versus 2.6%, respectively; p = 0.0013). At multivariate analysis, age ⩾ 75 years was associated with higher prevalence of bleeds. Conclusion: In conclusion, we found that in real-life conditions, the rate of bleeding events occurring during anticoagulation after a VTE episode is not higher in women than in men. Only after inclusion of vaginal bleeds, the rate of bleeding was higher in women. More bleeds (including vaginal bleeding) occurred in women treated with VKA than DOACs.

Introduction: Cancer-associated thrombosis (CAT) refers to the most common thromboembolic complication of cancer which is venous thromboembolism (VTE). CAT primary prophylaxis, treatment, and secondary prevention are challenging for the complexity of cancer patients, who exhibit hypercoagulability with concomitant-heightened bleeding risk. Areas covered: In this review, the author examines the role of low molecular weight heparins (LMWH), which have been the standard of care for CAT treatment for many years. Direct oral anticoagulants (DOACS) have practical advantages over subcutaneous LMWH, especially for long-term therapy. The author then discusses the results of two RCTs which separately compared the direct oral factor Xa inhibitors, apixaban or rivaroxaban, with placebo for CAT prophylaxis in ambulatory high-risk cancer patients and found that DOACS reduced VTE but increased bleeding. Finally, the author discusses four RCTS separately comparing an oral direct factor Xa inhibitor (edoxaban, rivaroxaban, or apixaban) with LMWH for CAT treatment. DOACS showed non-inferior efficacy, although rivaroxaban and edoxaban showed higher bleeding rates, especially in gastrointestinal cancers. Expert opinion: DOACS have a convenient route of administration and do not require laboratory monitoring, although choice of anticoagulants for CAT depends on factors such as tumor type, bleeding risk, concomitant drugs, and comorbidities.

The impact of the COVID-19 pandemic has been dramatic worldwide, with China, Italy, and now US at its epicenter. Researchers and clinicians are studying and testing different approaches in the attempt to prevent the infection and minimize its severity. Major efforts are focused on optimizing mechanical ventilation, antiviral, and supportive treatment; however, the role of heparin and low molecular weight (LMW) heparin in this setting has been largely overlooked. This review summarizes the available evidence about the role of heparan sulfate as a key entry mechanism for SARS-CoV-2; the efficacy of heparin and LMW heparin in counteracting its entry into the cell, the recent experimental findings obtained in in vitro studies using the LMW heparin enoxaparin Inhixa®, the role of heparin and LMW heparin in modulating the cytokine storm, and the evidence for the use of LMW heparin in the prevention and treatment of the thromboembolic complications of COVID-19. The available evidence suggests that LMW heparin appears as a promising tool in the treatment of COVID-19. Whether its systematic use is associated with a reduction in complications and ultimately mortality of these patients is being tested in several studies starting worldwide.

Background Heparin administration in COVID-19 patients is recommended by expert consensus, although evidence about dosage, duration and efficacy are limited. We aim to investigate the association between different dosages of low molecular weight heparin (LMWH) and mortality among COVID-19 hospitalized patients. Methods and results Retrospective study of 450 laboratory-confirmed COVID-19 patients admitted to Sant'Orsola Bologna Hospital from March 01 to April 10, 2020. Clinical, laboratory and treatment data were collected and analyzed. The in-hospital mortality between COVID-19 patients treated with standard prophylactic LMWH dosage vs. intermediate LMWH dosage was compared. Out of 450 patients, 361 received standard deep vein thrombosis (DVT) prophylaxis enoxaparin treatment (40-60mg daily) and 89 patients received intermediate enoxaparin dosage (40-60 mg twice daily) for 7 days. No significant differences in the main demographic characteristics and laboratory testings at admission were observed in the two heparin regimen subgroups, except for older age and prevalence of hypertension in the group treated with "standard" prophylaxis LMWH dosage. The intermediate LMWH administration was associated with a lower in-hospital all-cause mortality compared to the "standard" prophylactic LMWH dosage (18.8% vs. 5.8%, p = 0.02). This difference remained significant after adjustment with the propensity score for variables that differed significantly between the dosage groups (OR= 0.260, 95% CI 0.089-0.758, p=0.014). Conclusions Intermediate LMWH dosage seems to be associated with lower incidence of mortality compared to standard DVT prophylaxys in hospitalized COVID-19 patients. Our study paves the way to further pathophysiological investigations and controlled studies of anticoagulation therapy in Covid-19 disease.

Introduction: To measure direct factor Xa inhibitor (apixaban, edoxaban, rivaroxaban) concentrations, dedicated chromogenic anti-Xa assays are recommended as suitable methods to provide rapid drug quantification. Moreover, the high-performance liquid chromatography with ultraviolet detection (HPLC-UV) is reported as a reliable quantitative technique. We investigated seven anti-Xa assays and an HPLC-UV method for measurement of apixaban and rivaroxaban levels in patients enrolled in the START-Register. Methods: A total of 127 apixaban and 124 rivaroxaban samples were tested by HPLC-UV and the following anti-Xa assays: Biophen DiXaI and Heparin LRT (Hyphen BioMed), Berichrom and Innovance Heparin (Siemens), STA-Liquid Anti-Xa (Stago Diagnostics), Technochrom anti-Xa (Technoclone), and HemosIL Liquid Anti-Xa (Werfen). Each method was performed in one of the participating laboratories: Bologna, Cremona, Florence, and Padua. Results: Our data confirmed the overestimation of apixaban and rivaroxaban levels by the antithrombin-supplemented anti-Xa method (Berichrom). Performances and reproducibility of the six anti-Xa assays not supplemented with antithrombin and the HPLC-UV method were good, with limits of quantification from 8-39ng/mL (apixaban) and 15-33ng/mL (rivaroxaban). The six chromogenic methods showed good concordances with the quantitative HPLC-UV [bias: −26.9-22.3ng/mL (apixaban), −11.3-18.7ng/mL (rivaroxaban)]. Higher bias and wider range between limits of agreement were observed at higher concentrations [200ng/mL: bias −42.2-36.8ng/mL (apixaban) and −20.1-68.9ng/mL (rivaroxaban)]. Conclusion: Overall, the anti-Xa assays not supplemented with antithrombin and the HPLC-UV method proved to be suitable for apixaban and rivaroxaban quantification.

The post-thrombotic syndrome (PTS) is a long-term complication of deep vein thrombosis (DVT) of the lower limbs occurring in 40–50% of patients (1). Impaired thrombus resolution with persistent obstruction is involved in the pathogenesis of PTS, similarly to chronic thromboembolic pulmonary hypertension (CTEPH), which however develops only in a small minority of subjects after pulmonary embolism (PE)(2). Both PTS and CTEPH are associated with substantial morbidity and high healthcare expenses (2). PTS epidemiology reflects that of venous thromboembolism (VTE), which is estimated to affect 104–183 subjects per 100,000 person-years among Caucasians (3, 4), encompassing PE and DVT, with an incidence ranging from 29 to 78 and 45 to 117, per 100,000 person-years, respectively (5, 6). PTS can occur in severe forms in 10% and with the development of leg ulcers in 1–3% of patients (1). Leg ulcers …

The post-thrombotic syndrome (PTS) is a long-term complication of deep vein thrombosis (DVT) of the lower limbs occurring in 40–50% of patients (1). Impaired thrombus resolution with persistent obstruction is involved in the pathogenesis of PTS, similarly to chronic thromboembolic pulmonary hypertension (CTEPH), which however develops only in a small minority of subjects after pulmonary embolism (PE) (2).

© 2018 European Federation of Internal Medicine Despite recent advances in the treatment of Deep Vein Thrombosis (DVT) provided by Direct Oral Anticoagulants (DOAC), a substantial proportion of lower limb DVT patients will develop some degree of post-thrombotic syndrome (PTS) within 2 years. Systemic thrombolysis, although effective in reducing the risk of PTS and leg ulceration, is associated with a high risk of major bleeding, making it unsuitable for the vast majority of patients. A local approach, aimed at delivering the fibrinolytic drug directly into, or near to, the thrombus surface, is attractive because of the possibility of lowering of the administered drug dose, thus reducing the bleeding risks. However, even after the recent publication of the ATTRACT trial, only weak evidence is available about the efficacy and safety of Catheter Directed Thrombolysis (CDT), either alone (pharmacological technique) or in combination with additional endovascular approaches (pharmacomechanical technique, PMT) including percutaneous mechanical thrombectomy, angioplasty with or without stenting and ultrasound-assisted CDT. The present review is aimed at providing the physicians with a comprehensive evaluation of the current evidence about this relevant topic, in order to build a reliable conceptual framework for a more appropriate use of this resource.

Deep vein thrombosis (DVT) is an important cause of morbidity and mortality in hospitalized patients. The Wells score for DVT pretest probability (PTP) was validated in outpatients, but its utility for inpatients is unclear. The aim of this study was to establish the prevalence of inpatient proximal and distal DVT and the Wells score performance in inpatients. A single-center cross-sectional study was conducted in a university hospital. During 183days, all inpatients with suspected lower-extremity DVT were evaluated with the Wells score and whole-leg ultrasound. Among 634 inpatients (age 77.5 ± 13.8 years, males 39.3%), 507 (80.0%) were from medical wards and 127 (20.0%) from surgical wards. During the study period, there were 11,662 hospital admissions in the surgical/medical services. Whole-leg ultrasound detected 128 DVTs (20.2%); 51 (39.8%) were proximal and 77 (60.1%) were isolated distal DVTs. Estimated DVT prevalence in hospital setting was 1.09% (95% CI 0.93–1.31), and isolated distal DVT prevalence was 0.66% (95% CI 0.53–0.82). DVT frequency in low-, moderate-, and high-PTP groups was 9.8%, 24.3%, and 41.5%, respectively (p = 0.001). The area under the receiver operating characteristic curve for the Wells score was 0.67 ± 0.03 for all DVTs and 0.75 ± 0.04 for only proximal DVTs. A high PTP had a sensitivity of 24% (95% CI 14–37%) and a specificity of 93% (95% CI 91–95%) for proximal DVT diagnosis. In hospitalized patients, isolated distal DVT has a higher incidence than expected, and the Wells score accuracy for proximal DVT is similar to that found in outpatients.

BackgroundD-dimer levels measured during and after vitamin K antagonist withdrawal may be used in clinical practice to assess the individual risk of recurrent venous thromboembolism. Currently, direct oral anticoagulants (DOACs) are frequently used in venous thromboembolism treatment; however, their pharmacokinetics and pharmacodynamics characteristics are completely different than vitamin K antagonists. The present study aimed at comparing the results of D-dimer levels during and after anticoagulation withdrawal in patients with venous thromboembolism treated with DOACs or warfarin.Material and methodsD-dimer levels were measured in 527 patients ("cases") during DOACs treatment (T0) and after 15 (T15), 30 (T30), 60 (T60) and 90 (T90) days after their discontinuation and in 527 patients ("controls") enrolled in the DULCIS study (all treated with warfarin), matched for sex, age (+/-3 y), type of D-dimer assay and site of venous thromboembolism. Both cases and controls received anticoagulant treatment after a first venous thromboembolism event that was unprovoked or associated with weak risk factors.ResultsThe rate of positive D-dimer results was significantly higher in cases than in controls at T0 (10.8% vs 5.1%, p = 0.002) and at T30 (18.8% vs 11.8%, p = 0.019), as well as at the other time-points, though not statistically significant.ConclusionD-dimer levels during and after stopping an anticoagulant treatment for a venous thromboembolism episode differ between patients treated with a DOAC than in those treated with warfarin. Specifically designed prospective studies are warranted to reassess the use of D-dimer as predictor of the risk of recurrent venous thromboembolism in patients treated with DOACs.

Essentials Currently, DOACs are given at fixed doses and do not require laboratory monitoring. Direct oral anticoagulant-specific measurements were performed at trough and peak. Patients who developed bleeding events showed higher DOAC plasma levels at peak. This study suggests the need of a more accurate DOAC dose assessment. Background: Direct oral anticoagulants (DOACs) are administered at fixed dose. The aim of the study was to evaluate the relationship between DOAC C-trough or C-peak plasma levels and bleeding complications in patients with non-valvular atrial fibrillation (NVAF). Methods: Five hundred sixty five consecutive naive NVAF patients were enrolled. The DOAC measurements at C-trough and at C-peak (available in 411 patients) were performed at steady state, within the first month of treatment. Major bleeding (MB), clinically relevant non-major bleeding (CRNMB), and minor bleeding (MinB), occurring during 1year of follow-up after blood sampling, were recorded. For each DOAC, interval of C-trough and C-peak levels was subdivided into four equal classes and results were attributed to these classes; the median values of results were also calculated. Results: Two hundred eight patients were on apixaban, 185 on dabigatran, and 172 on rivaroxaban. For 1-[qqqdeletezzz]year follow up for all patients, we observed: 19 MB (3.36%), 6 CRNMB (1.06%), and 47 MinB (8.31%). The prevalence of bleeding patients with anticoagulant levels in the upper classes of C-peak activity (II + III + IV) was higher than that in the lowest class. Normalized results of C-peak levels were higher in patients with bleeding than in those without bleeding. Conclusions: Bleeding complications during DOAC treatment were more frequent among atrial fibrillation (AF) patients with higher C-peak anticoagulant levels. In addition to a previous study that showed an increased risk of thrombotic complications in the patients with low C-trough levels, this study seems to indicate that patients with NVAF on DOACs would need a more accurate definition of their optimal therapeutic window.

Essentials Few data exist on outcome of upper extremity deep and superficial vein thrombosis (UEDVT and UESVT). We followed 102 and 55 patients with UEDVT or UESVT, respectively, for a median of 3.5 years. Risk of recurrent venous thromboembolism was low in both diseases, and the mortality high. Postthrombotic symptoms were infrequent and cancer patients had a higher risk of recurrent VTE. Background There is scant information on the optimal management and clinical outcome of deep and superficial vein thrombosis of the upper extremity (UEDVT and UESVT). Objectives To explore treatment strategies and the incidence of recurrent venous thromboembolism (VTE), mortality, postthrombotic symptoms, and bleeding in patients with UEDVT and UESVT and to assess the prognosis of cancer patients with UEDVT. Patients/methods Follow-up of patients with UEDVT or UESVT, who were enrolled previously in a diagnostic management study. Results We followed 102 and 55 patients with UEDVT and UESVT, respectively, both for a median of 3.5 years. Anticoagulant treatment was started in 100 patients with UEDVT (98%) and in 40 (73%) with UESVT. Nine patients with UEDVT (9%) developed recurrent VTE, 26 (26%) died, 6 (8%) of 72 patients had moderate postthrombotic symptoms, and 5 (5%) experienced major bleeding. One patient with UESVT had a recurrent VTE, 18 (33%) died, none had moderate postthrombotic symptoms, and none had major bleeding. Of the cancer patients with UEDVT, 18% had recurrent VTE vs. 7.5% in non-cancer patients (adjusted hazard ratio 2.2, 95%CI 0.6-8.2). The survival rate was 50% in cancer patients with UEDVT vs. 60% in those without (adjusted HR 0.8, 95%CI 0.4-1.4). Conclusions The risk of recurrent VTE was low in patients with UEDVT, and negligible for UESVT. Mortality was high for both diseases. Postthrombotic symptoms were infrequent and mild. Anticoagulant therapy of UEDVT carried a substantial risk of major bleeding. Cancer patients had a significant risk of recurrent VTE

In the D-dimer and ULtrasonography in Combination Italian Study (DULCIS), serial D-dimer measurement in combination with assessment of residual thrombosis (in patients with deep vein thrombosis (DVT)) identified patients who safely discontinued anticoagulation after an unprovoked venous thromboembolism (VTE).In this subgroup analysis, the value of D-dimer tests was assessed in patients with isolated pulmonary embolism (PE) compared with those with DVT, with or without PE (DVT/PE). The DULCIS database was reanalysed in relation to this target.26.8% of the DULCIS patients had isolated PE as the index event; this was more prevalent in females (34.1%) than in males (21.1%; pversus 3.8% ppy; nonsignificant) who stopped anticoagulation for negative D-dimer, but it was markedly high (11.2% ppy; pversus two (7.4%) out of 27; p=0.0085).Serial D-dimer assessment can inform on the risk of recurrent VTE and help determine the duration of anticoagulation in patients with isolated PE.

Direct oral anticoagulants are associated with rates of major bleeding which are not negligible, albeit lower than those associated with vitamin K antagonists. No specific reversal agent for factor Xa (FXa) direct inhibitors is currently available for clinical use. A modified activated human FXa decoy protein, andexanet alfa, is being developed that binds FXa direct inhibitors in their active site, thus reversing their anticoagulant effect. The purpose of this article is to review the design, development and clinical trials of andexanet alfa. Andexanet alfa was shown to reverse FXa inhibitors anticoagulant activity both in thrombosis animal models, healthy volunteers and patients with acute major bleeding. Andexanet alfa has been studied in double-blind, placebo-controlled phase II and III studies. A preliminary report of the phase III study showed that an effective hemostasis was obtained after andexanet alfa infusion in the majority of the patients with acute major bleeding associated with FXa inhibitors. Additional studies are ongoing and andexanet alfa is expected to be launched in the market in the near future.

Essentials Direct oral anticoagulants (DOACs) do not require laboratory monitoring currently. DOAC specific measurements were performed at trough in patients with atrial fibrillation. Patients who developed thromboembolic events showed lower DOAC plasma levels. This study supports the concept of measuring DOAC levels at steady state. Summary: Background Direct oral anticoagulants (DOACs) are administered at fixed doses without the need for dose adjustment according to laboratory testing. High interindividual variability in drug blood levels has been shown with all DOACs. To evaluate a possible relationship between DOAC C-trough anticoagulant levels and thromboembolic events, 565 consecutive naive patients with atrial fibrillation (AF) were enrolled in this study performed within the START Laboratory Registry. Methods DOAC-specific measurements (diluted thrombin time or anti-activated factor II calibrated for dabigatran; anti-activated FX calibrated for rivaroxaban or apixaban) at C-trough were performed locally at steady state within 15–25 days after the start of treatment. For each DOAC, the interval of C-trough levels, from the limit of quantification to the highest value, was subdivided into four equal classes, and results were attributed to these classes; the median values of results were also calculated. Thromboembolic complications occurring during 1 year of follow-up were recorded. Results Thromboembolic events (1.8%) occurred in 10 patients who had baseline C-trough levels in the lowest class of drug levels. The incidence of thromboembolic events among patients with DOAC C-trough levels in the lowest level class was 2.4%, and that in the remaining groups was 0%. The patients with thrombotic complications also had a higher mean CHA2DS2-VASc score than that of the total patient population: 5.3 (95% confidence interval [CI] 4.3–6.3 versus 3.0 (95% CI 2.9–3.1). Conclusion In this study cohort, thrombotic complications occurred only in DOAC-treated AF patients who had very low C-trough levels, with a relatively high CHA2DS2-VASc score. Larger studies are warranted to confirm these preliminary observations. © 2018 The Authors. Journal of Thrombosis and Haemostasis published by Wiley Periodicals, Inc. on behalf of International Society on Thrombosis and Haemostasis.

Introduction: Several specific assays are commercially available to determine dabigatran anticoagulant activity. Aims of this multicenter and multiplatform study were to compare five methods for dabigatran measurement and investigate their performances in the low concentration range. Methods: Dabigatran levels were analyzed in 295 plasma samples from patients enrolled in the START-Laboratory Register by the following methods using dedicated calibrators and controls: STA-ECA II (Diagnostica Stago), standard and low range Hemoclot Thrombin Inhibitors (Hyphen BioMed), Direct Thrombin Inhibitor Assay (Instrumentation Laboratory), Direct Thrombin Inhibitor Assay (Siemens), Technoclot DTI (Technoclone). Results: Methods showed variable agreement with the Hemoclot Thrombin Inhibitors assay used as reference test, with modest under- or overestimations (Bland-Altman bias from −17.3 to 4.0 ng/mL). Limits of detection and quantification varied depending on the assay (4-52 and 7-82 ng/mL, respectively). Between-run precision and accuracy were good for all methods for both quality control levels. Assay's repeatability assessed at very low dabigatran concentrations (from 10 to 60 ng/mL) was also acceptable, variability generally increased at lower drug levels. Conclusion: The five dabigatran-specific assays evaluated in this study provided reliable assessment of dabigatran plasma levels, although showing different performances. © 2018 The Authors. International Journal of Laboratory Hematology Published by John Wiley & Sons Ltd

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Essentials Predicting recurrences may guide therapy after unprovoked venous thromboembolism (VTE). We evaluated the DASH score in 827 patients with unprovoked VTE to verify prediction accuracy. A DASH score ≤ 1 had a cumulative recurrence risk at 1 year of 3.6%, as predicted by the model. The DASH score performed better in younger (< 65 years old) subjects. Summary: Background The DASH prediction model has been proposed as a guide to identify patients at low risk of recurrence of venous thromboembolism (VTE), but has never been validated in an independent cohort. Aims To validate the calibration and discrimination of the DASH prediction model, and to evaluate the DASH score in a predefined patient subgroup aged > 65 years. Methods Patients with a proximal unprovoked deep vein thrombosis (DVT) or pulmonary embolism (PE) who received a full course of vitamin K antagonist or direct oral anticoagulant (> 3 months) and had D-dimer measured after treatment withdrawal were eligible. The DASH score was computed on the basis of the D-dimer level after therapy withdrawal and personal characteristics at the time of the event. Recurrent VTE events were symptomatic proximal or distal DVT/PE, and were analyzed with a time-dependent analysis. Observed 12-month and 24-month recurrence rates were compared with recurrence rates predicted by the DASH model. Results We analyzed a total of 827 patients, of whom 100 (12.1%) had an objectively documented recurrence. As compared with the original DASH cohort, there was a greater proportion of subjects with a ‘low-risk’ (≤ 1) DASH score (66.3% versus 51.6%, P < 0.001). The slope of the observed versus expected cumulative incidence at 2 years was 0.71 (95% confidence interval 0.51–1.45). The c-statistic was lower for subjects aged > 65 years (0.54) than for younger subjects (0.72). Conclusions These results confirm the validity of DASH prediction model, particularly in young subjects. The recurrence risk in elderly patients (> 65 years) was, however, > 5% even in those with the lowest DASH scores.

Background The optimal long-term strategy for preventing recurrent venous thromboembolism (VTE) in patients with deep-vein thrombosis (DVT) is uncertain. Methods In 620 consecutive outpatients with a first proximal DVT who had completed at least three months of anticoagulation (unprovoked in 483, associated with minor risk factors in 137), the ultrasound presence of residual vein thrombosis (RVT) was assessed and defined as an incompressibility of at least 4 mm. In 517 patients without RVT and with negative D-dimer, anticoagulation was stopped and D-dimer was repeated after one and three months. Anticoagulation was resumed in 63 of the 72 patients in whom D-dimer reverted to positivity. Results During a mean follow-up of three years, recurrent VTE developed in 40 (7.7%) of the 517 patients, leading to an annual rate of 3.6% (95% CI, 2.6 to 4.9): 4.1% (95% CI, 2.9 to 5.7) in individuals with unprovoked DVT, and 2.2% (95% CI, 1.1 to 4.5) in those with DVT associated with minor risk factors. Of the 233 males with unprovoked DVT, 17 (7.3%) developed events in the first year of follow-up. Major bleeding complications occurred in 8 patients while on anticoagulation, leading to an annual rate of 1.2% (95% CI, 0.6 to 2.4). Conclusions Discontinuing anticoagulation in patients with a first episode of proximal DVT based on the assessment of RVT and serial D-dimer leads to an overall annual rate of recurrent VTE lower than 5.0%, which is the rate deemed as acceptable by the Subcommittee on Control of Anticoagulation of the ISTH. However, in males with unprovoked DVT there is room for further improving the long-term strategy of VTE prevention. ( ClinicalTrials.gov number, NCT01285661 ).

no abstract available

Calf deep vein thrombosis (CDVT) ultrasound diagnostic criteria are still debated. A clot >= 3.5 mm may be an appropriate threshold for CDVT diagnosis. Six week heparin treatment is associated with recanalization in half of patients with CDVT. Objective/Background: Calf deep vein thrombosis (CDVT) is frequently found in symptomatic outpatients, but CDVT ultrasound diagnostic criteria are still debated. It has been proposed that only clots with >= 5 mm maximum diameter can be considered as CDVT. Aims: To assess clot diameters and characteristics of CDVT, and to assess the recanalization rate of CDVT after anticoagulant treatment. Methods: In a prospective, multicenter cohort study symptomatic outpatients in whom CDVT was diagnosed by ultrasound were enrolled. Posterior tibial, fibular, medial and lateral gastrocnemius, and soleal veins were compressed transversally over their entire length. Clot diameter was measured during maximum compression and ultrasound was repeated after 6 weeks of low molecular weight heparin treatment. Results: In 172 patients (age 70 +/- 1 y, male 32%) CDVT was detected in 132 (76.7%) muscle veins only, and in 24 (14%) axial veins only, while 16 (9.3%) patients had both muscular and axial CDVT. A total of 212 clots were found with a diameter of 5.8 +/- 1.8 mm (IQR 4.5-6.8 mm) with the 10th percentile being >= 3.5 mm. A cut off value of >= 5 mm had a sensitivity of 0.76 (95% CI 0.69-0.82), whereas a value of >= 3.5 mm had a sensitivity of 0.94 (95% CI 0.89-0.97). Recanalization (i.e. residual vein obstruction = 5 mm is found in only 76% of CDVT patients and a clot diameter >= 3.5 mm may be more appropriate as a threshold for CDVT. After 6 weeks of anticoagulant treatment, half of CDVT patients had recanalization and recanalization was not correlated with clot characteristics at enrolment, but with mobility of the patients. (C) 2016 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

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Background The risk of heparin induced thrombocytopenia (HIT) associated with low molecular weight heparin (LMWH) for treatment of superficial vein thrombosis (SVT) is uncertain. As a result the necessity of platelet count monitoring is unclear in this setting. Aims To assess the risk of HIT in outpatients treated with LMWH for SVT. Methods In a prospective single centre study we included all symptomatic outpatients in whom a real-time B-mode and color Doppler ultrasonography examination revealed SVT without DVT. Patients treated with vitamin K antagonists or fondaparinux were excluded. Patients received full dose enoxaparin for 1 week followed by half therapeutic dose for 3 weeks or parnaparin 8500 UI aXa for 10 days followed by 6400 UI aXa once daily for 20 days. Platelet count was performed on the day of diagnosis (D0) and 7 (D7), and 14 (D14) days afterward. Primary outcomes were the rate of thromboembolic events and of HIT during a 3-month follow-up. Results 678 outpatients (age: 64.7 ± 16.2 years, male: 42.0%) were evaluated. During follow-up, 7 venous thrombo-embolic events were recorded (1.03% CI 95%: 0.50–2.11%), while no major bleeding was observed (0.0% CI 95%: 0.0–0.56%). Platelet count was 255 ± 93 × 109/L at D0, 245 ± 93 × 109/L at D7 (p = 0.204 vs. D0) and 261 ± 116 × 109/L at D14 (p = 0.405 vs. D0). No fall in platelet count > 50% and no case of HIT were recorded (HR 0.0% CI 95%: 0–0.56%). Conclusions A 4-week LMWH treatment for SVT is associated with an incidence of HIT lower than 0.6% and platelet count monitoring may be omitted in this setting.

Background The diagnosis and treatment of disseminated intravascular coagulation (DIC) remain extremely controversial. Purpose The Italian Society for Thrombosis and Haemostasis commissioned a project to develop clinical practice guidelines for the diagnosis and treatment of DIC. Methods Key questions about the diagnosis and treatment of DIC were formulated by a multidisciplinary working group consisting of experts in clinical medicine and research. After a systematic review and discussion of the literature, recommendations were formulated and graded according to the supporting evidence. In the absence of evidence, evidence of low quality, or contradictory evidence, a formal consensus method was used to issue clinical recommendations. Results and Conclusions In suspected DIC, we suggest the use of the diagnostic scores ISTH (grade C), JMHW (grade C) or JAAM (grade D) over stand alone tests. The cornerstone of the management of DIC remains the treatment of the underlying triggering disease. We do not suggest the use of antithrombin (grade D), dermatan sulphate (grade D), gabexate (grade D), recombinant factor VIIa (grade D), activated protein C (grade D), thrombomodulin (grade B). The use of unfractionated heparin or low-molecular-weight heparin is not suggested except for thromboembombolic prophylaxis in patients a high risk who do not have active bleeding (grade D). In patients with severe sepsis/septic shock and DIC we suggest the use of human recombinant activated protein C (grade D). In patients with DIC and active bleeding we suggest the use of transfusion therapy (platelets, plasma, cryoprecipitate) (grade D).

[No abstract available]

The rate of resolution of a first episode of pulmonary embolism (PE) is uncertain. A baseline test indicating any residual PE is pivotal in aiding a more accurate diagnosis of recurrent PE. This study aimed to assess the rate and risk factors of residual PE with either multidetector computed tomography imaging (MDCT) or lung perfusion scan (LPS) using a cross-sectional study in which consecutive patients were enrolled with a first objectively documented episode of symptomatic PE, and who were considered for possible treatment withdrawal after at least 3 months of anticoagulation. A first cohort of patients (n = 80) underwent MDCT, while the subsequent cohort (n = 93) underwent LPS. The two cohorts had similar characteristics, and 98.3% of patients had non high-risk index PE. MDCT detected residual PE in 15% of subjects (12/80, 95% CI 8-25%) after a mean of 9 months of anticoagulation. No clinical characteristics were significantly associated with residual PE at MDCT. LPS detected residual PE in 28% (26/93, 95% CI 19-38%) of patients after a period of a mean of 9 months of anticoagulation with a significant association with increasing age and known pulmonary disease. Resolution of PE was high after a first episode of non high-risk PE treated with heparin followed by at least 3 months of anticoagulation. Age and coexistent pulmonary disease influence the presence of residual PE detected by LPS, but not by MDCT. Further studies are warranted in which the presence of residual embolism is detected by repetition of the same test that had been initially carried out.

The WHO scheme for prothrombin time (PT) standardization has been limited in application, because of its difficulties in implementation, particularly the need for mandatory manual PT testing and for local provision of thromboplastin international reference preparations (IRP).The value of a new simpler procedure to derive international normalized ratio (INR), the PT/INR Line, based on only five European Concerted Action on Anticoagulation (ECAA) calibrant plasmas certified by experienced centres has been assessed in two independent exercises using a range of commercial thromboplastins and coagulometers. INRs were compared with manual certified values with thromboplastin IRP from expert centres and in the second study also with INRs from local ISI calibrations.In the first study with the PT/INR Line, 8.7% deviation from certified INRs was reduced to 1.1% with human reagents, and from 7.0% to 2.6% with rabbit reagents. In the second study, deviation was reduced from 11.2% to 0.4% with human reagents by both local ISI calibration and the PT/INR Line. With rabbit reagents, 10.4% deviation was reduced to 1.1% with both procedures; 4.9% deviation was reduced to 0.5% with bovine/combined reagents with local ISI calibrations and to 2.9% with the PT/INR Line. Mean INR dispersion was reduced with all thromboplastins and automated systems using the PT/INR Line.The procedure using the PT/INR Line provides reliable INR derivation without the need for WHO ISI calibration across the range of locally used commercial thromboplastins and automated PT systems included in two independent international studies.? 2010 International Society on Thrombosis and Haemostasis.

SummaryD-dimer and residual venous obstruction (RVO) have been separately shown to be risk factors for recurrent venous thromboembolism (VTE) after a first episode of unprovoked proximal deep-vein thrombosis (DVT). It was the objective of this study to assess the predictive value of D-dimer and residual vein obstruction (RVO), alone and in combination, for recurrence after provoked DVT of the lower limbs. A total of 296 consecutive patients with a first episode of symptomatic provoked proximal DVT were evaluated at a university hospital in Bologna, Italy. On the day of anticoagulation withdrawal (T0), RVO was determined by compression ultrasonography. D-dimer levels (cut-off: 500 ng/ml) were measured at T0 and after 30 ±10 days (T1). The main outcome was recurrent VTE during a two-year follow-up. D-dimer was abnormal in 11.6% (32/276) and 31% (85/276) of subjects at T0 and at T1, respectively. RVO was present in 44.8% (132/294) of patients. Recurrence rate was 5.1% (15/296; 95% confidence interval [CI]: 3–8%; 3% patient-years; 95% CI: 2–5 %). An abnormal D-dimer either at T0 or at T1 was associated with an adjusted hazard ratio (HR) for recurrence of 4.2 (95% CI:1.2–14.2; p=0.02) and 3.8 (95%CI: 1.2–12.1; p=0.02), respectively, when compared with normal D-dimer. The HR for recurrence associated with RVO was not significant, and RVO did not increase the recurrence risk associated with an abnormal D-dimer either at T0 or T1. In conclusion, an abnormal D-dimer during vitamin K antagonist (VKA) treatment or at one month after VKA withdrawal is a risk factor for recurrence in patients with provoked DVT, while RVO at the time of anticoagulation withdrawal is not.

Evaluation of the risk of recurrent venous thromboembolism (VTE) is required to determine the optimal duration of secondary prophylaxis. Application of global assays reflecting the pro- versus anti-coagulant balance in vivo would be desirable. We aimed at investigating the relationship between recurrent VTE and the Protac-induced coagulation inhibition (PICI) assay, which is based on tissue factor-induced thrombin generation measured by a chromogenic substrate. One-hundred-ninety patients were followed-up after a first episode of unprovoked, objectively documented VTE for 2.7 years after stopping treatment with vitamin K antagonists (VKA). PICI was measured 1 month after stopping treatment as the percentage of the OD values recorded without or with Protac. The lower the PICI%, the greater the pro- versus anti-coagulant imbalance. The study outcome was objectively-documented symptomatic recurrent VTE. Patients with PICI% ≤ 74% had crude hazard-ratios (HR) (95% CI) for recurrent VTE of 2.86 (1.01–8.12) as compared to those with PICI% > 87%. After adjustment for age, gender, type of index event, VKA duration and normal/abnormal D-Dimer, HR (95% CI) were substantially unchanged [2.91 (1.01–8.38)]. The corresponding values after further adjustment for the above variables plus the absence/presence of the most frequent thrombophilic alterations were 3.38 (1.16–9.84). These HR values compare favorably with those obtained in a previous study investigating the thrombin generation test performed in the presence of thrombomodulin. In conclusion, the measurement of PICI helps to identify patients at higher risk of VTE recurrence. Advantages of PICI over thrombin generation tests are easy performance in general clinical laboratories, easy standardization and no special equipment.

The PROLONG randomized trial showed that a normal D-dimer (D-d) 1 month after anticoagulation suspension for unprovoked venous thromboembolism (VTE) was associated with a low risk of late recurrences (4.4% patient years). However, it is unknown whether D-d changes subsequently. The aim of this prospective multicenter study was to assess D-d time course and its relation with late recurrences in patients with normal D-d 1 month after anticoagulation suspension for a first episode of unprovoked VTE. D-d was measured with a qualitative method (Clearview Simplify D-dimer; Inverness Medical Professional Diagnostics). Patients with a normal D-d 1 month after stopping anticoagulation repeated D-d testing every 2 months for 1 year. D-d was normal in 68% (243/355) of patients 1 month after anticoagulation suspension. Patients in whom D-d became abnormal at the third month and remained abnormal afterward had a higher risk of recurrence (7/31; 27% patient years; 95% confidence interval [CI]: 12-48) than patients in whom D-d remained normal at the third month and afterward (4/149; 2.9% patient years; 95% CI: 1-7; adjusted hazard ratio: 7.9; 95% CI: 2.1-30; P = .002). Repeated D-d testing after anticoagulation suspension for a first episode of unprovoked VTE could help tailor the duration of treatment. This trial is registered at http://clinicaltrials.gov as NCT00266045.