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VTE
Kinds of VTE Terms modified by VTE Selected AbstractsGrowth, etching morphology and spectra of LiAlO2 crystalCRYSTAL RESEARCH AND TECHNOLOGY, Issue 8 2008Taohua Huang Abstract ,-LiAlO2 single crystal was successfully grown by Czochralski method. The crystal quality was characterized by X-ray rocking curve and chemical etching. The effects of air-annealing and vapor transport equilibration (VTE) on the crystal quality, etch pits and absorption spectra of LiAlO2 were also investigated in detail. The results show that the as-grown crystal has very high quality with the full width at half maximum (FWHM) of 17.7-22.6 arcsec. Dislocation density in the middle part of the crystal is as low as about 3.0×103 cm,2. The VTE-treated slice has larger FWHM value, etch pits density and absorption coefficient as compared with those of untreated and air-annealed slices, which indicates that the crystal quality became inferior after VTE treatment. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Current concepts for the prevention of venous thromboembolismEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 2005P. Bramlage Abstract Venous thromboembolism (VTE) is a major cause of morbidity and mortality worldwide and the annual incidence of VTE is 1 per 1000. The individual risk for venous thromboembolism may be substantially higher and is determined by expositional and dispositional factors. Unfractionated heparin and warfarin have been the mainstays for the prevention of VTE until the early 1980s. Bleeding complications and side effects limited the use of these agents and subsequently low molecular weight heparins (LMWH) were introduced into clinical practice. These are most commonly used for the prophylaxis and treatment of VTE today. In the last decade, the pace of development of further anticoagulants has accelerated with the introduction of new treatment regimens and new substances. In this context, novel drugs directed against clotting factor Xa (such as fondaparinux) and direct thrombin inhibitors (such as melagatran/ximelagatran) have been developed. Fondaparinux shows a favourable efficacy/safety profile and has been documented to be cost-effective compared to enoxaparin in the US and the UK. [source] Rivaroxaban , an oral, direct Factor Xa inhibitor , lessons from a broad clinical study programmeEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 5 2009Sylvia Haas Abstract Anticoagulants are recommended for the prevention and treatment of venous thromboembolism (VTE), prevention of stroke in patients with atrial fibrillation (AF) and secondary prevention in patients with acute coronary syndrome (ACS). There is a clinical need for novel anticoagulants offering improvements over current standard of care, such as fixed oral dosing and no need for routine monitoring. Rivaroxaban, an oral, once-daily, direct Factor Xa inhibitor, has recently completed the RECORD phase III programme for the prevention of VTE in patients undergoing total hip or knee replacement (THR or TKR), an indication for which it is approved in Europe and Canada. It is being investigated in large-scale phase III studies for VTE treatment and prevention of stroke in patients with AF, and phase III studies will soon commence for secondary prevention in patients with ACS. Phase I studies demonstrated that no routine anticoagulation monitoring was required, while phase II studies suggested that fixed daily doses had a wide therapeutic window. The four RECORD studies consistently showed that rivaroxaban was significantly more effective than enoxaparin in the prevention of VTE after THR and TKR, with a similar safety profile. This review describes the development of this novel anticoagulant, from bench to bedside. [source] Prolonged seated immobility at work is a common risk factor for venous thromboembolism leading to hospital admissionINTERNAL MEDICINE JOURNAL, Issue 2 2008S. Aldington Abstract The role of seated immobility at work in the pathogenesis of venous thromboembolism (VTE) is uncertain. In this case series, 61 patients aged <65 years with a recent admission for deep venous thrombosis and/or pulmonary embolism completed an interviewer-administered questionnaire to obtain information regarding risk factors. Prolonged seated immobility at work in the 4 weeks before the VTE event was defined as being seated at least 8 h in a 24-h period and at least 3 h at a time without getting up, at least 10 h in a 24-h period and at least 2 h at a time without getting up or at least 12 h in a 24-h period and at least 1 h at a time without getting up. The most commonly identified risk factors were family history of VTE (21 of 61, 34%), seated immobility at work (21 of 61, 34%) and a thrombophilic state (19 of 61, 31%). We conclude that prolonged seated immobility at work may represent a common and important risk factor for VTE. [source] A need for a simplified approach to venous thromboembolism prophylaxis in acute medical inpatientsINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 2 2007D. P. J. Howard Summary Venous thromboembolism (VTE) is a major cause of morbidity and mortality in the UK. Studies have shown that pulmonary embolism causes or contributes to approximately 1 in 10 hospital deaths of medical patients admitted to general hospitals in the UK (Lindblad B, Sternby NH, Bergqvist D. BMJ 1991; 302: 709,11), with pulmonary embolus being the most common preventable cause of hospital death. Thromboprophylaxis is safe, highly effective and cost effective, but despite various current clinical guidelines, physicians fail to prescribe prophylaxis for the majority of medical inpatients at risk of VTE. This article outlines the current evidence for VTE prophylaxis in medical patients and discusses the reasons behind the insufficient use of prophylaxis in the acute medical setting. [source] Venous thromboembolism in the medically ill patient: a call to actionINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 5 2005J.-F. Bergmann Summary The risk of venous thromboembolism (VTE) in medical patients is generally underestimated. However, recent studies including two large double-blind placebo-controlled trials, the Prospective Evaluation of Dalteparin Efficacy for Prevention of VTE in Immobilised Patients trial (PREVENT) and prophylaxis in MEDical patients with ENOXaparin, study show that low-molecular-weight heparins (LMWHs) provide effective thromboprophylaxis for medical patients at risk from VTE without increasing the risk of bleeding. In PREVENT the significant 45%, reduction in VTE among patients receiving dalteparin 5000 IU once daily for 14 days was attributed entirely to a reduction in clinically relevant VTE. The recently published guidelines for the prevention and treatment of VTE, issued by the American College of Chest Physicians, recommend prophylaxis with LMWHs (or low-dose unfractionated heparin) in acutely ill medical patients with risk factors for VTE (grade 1A). Current evidence should encourage the more widespread adoption of thromboprophylaxis in at-risk medical patients, and thus reduce the number of preventable deaths and complications due to VTE. [source] Current perspectives on the treatment of venous thromboembolism: need for effective, safe and convenient new antithrombotic drugsINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 3 2004D.F. O'Shaughnessy Summary Treatment of venous thromboembolism (VTE) has evolved significantly over the last decade. Low-molecular-weight heparins have largely replaced unfractionated heparin in the treatment of deep-vein thrombosis (DVT) but the majority of patients with pulmonary embolism (PE) continue to be treated with unfractionated heparin. Fondaparinux is the first synthetic selective inhibitor of factor Xa. It has recently been proved to be more effective than, and as safe as, a low-molecular-weight heparin for the prevention of VTE after major orthopaedic surgery. The two large randomised MATISSE trials demonstrated that fondaparinux was at least as effective and as safe as previous reference heparin therapies in the treatment of VTE. Fondaparinux should further simplify the treatment of this frequent disease since a single once-daily fixed dosage regimen may effectively and safely treat both DVT and PE, an important point especially considering the frequent though clinically silent concomitance of these two thrombotic events. [source] The use of thrombelastography to determine coagulation status in severe anorexia nervosa: A case seriesINTERNATIONAL JOURNAL OF EATING DISORDERS, Issue 4 2010Jennifer L. Gaudiani MD Abstract Objective: Hospitalized patients with severe anorexia nervosa (AN) frequently have a complex coagulation profile, with elements of hypocoagulability-thrombocytopenia and elevated international normalized ratio (INR) and elements of hypercoagulability-usually manifested as immobility, which is either due to their marked weakness or from enforced degrees of bed rest to minimize energy expenditure. Hospitalized medical patients have been shown to have appropriate prophylaxis for venous thromboembolic (VTE) disease in only 40% of cases. Method: A simple test that could evaluate the overall coagulation profile of these patients would help guide appropriate VTE prophylaxis. The thrombelastogram is a blood test that evaluates the full dynamic process of hemostasis. Results: The study of patients did not reveal evidence of being hypocoagulable and thus should be considered for VTE prophylaxis. Discussion: We report on three cases of young women with severe AN and weakness, hospitalized for closely monitored refeeding, in whom the thromboelastogram was used to evaluate the coagulation status of the patient and assist in guiding therapy. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2010 [source] ORIGINAL ARTICLE: Comparison of a point of care device against current laboratory methodology using citrated and EDTA samples for the determination of D-dimers in the exclusion of proximal deep vein thrombosisINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 5 2010P. M. BAKER Summary D-dimer estimation is a routine part of diagnostic algorithms for the exclusion of venous thromboembolism (VTE). We evaluated a point of care device, Biosite Triage (Inverness Medical UK, Cheshire, UK) for the estimation of D-dimers in both samples taken into citrate and EDTA against our routine laboratory D-dimer (Liatest D-dimer, Diagnostica Stago, Reading, UK) performed on the STA-R Evolution. With informed consent, 102 consecutive patients presenting with possible deep vein thrombosis (DVT) were enrolled and D-dimers along with Wells scores and compression ultrasonography (CUS) were recorded. Using the manufacturers' recommended cut offs of 500 ,g/l fibrinogen equivalent units and 400 ,g/l for the Stago and Triage, respectively, sensitivity, specificity, positive and negative predictive values were calculated. These were 1.00, 0.42, 0.17, and 1.00 for the Triage machine using citrate samples, 1.00, 0.32, 0.14, and 1.00 using EDTA samples and 1.00, 0.29, 0.16, and 1.00 for the Stago Liatest assay, respectively. Three patients had significantly higher results for the Stago Liatest D-dimer assay compared with the Biosite Triage device although ultrasound scans were negative. Conclusion: The Biosite Triage D-dimer assay performed on either citrate or EDTA samples is comparable with the Stago Liatest laboratory D-dimer assay when used in conjunction with clinical pretest probability scoring and CUS for the exclusion of DVT. [source] Accuracy of Very Low Pretest Probability Estimates for Pulmonary Embolism Using the Method of Attribute Matching Compared with the Wells ScoreACADEMIC EMERGENCY MEDICINE, Issue 2 2010Jeffrey A. Kline MD Abstract Objectives:, Attribute matching matches an explicit clinical profile of a patient to a reference database to estimate the numeric value for the pretest probability of an acute disease. The authors tested the accuracy of this method for forecasting a very low probability of venous thromboembolism (VTE) in symptomatic emergency department (ED) patients. Methods:, The authors performed a secondary analysis of five data sets from 15 hospitals in three countries. All patients had data collected at the time of clinical evaluation for suspected pulmonary embolism (PE). The criterion standard to exclude VTE required no evidence of PE or deep venous thrombosis (DVT) within 45 days of enrollment. To estimate pretest probabilities, a computer program selected, from a large reference database of patients previously evaluated for PE, patients who matched 10 predictor variables recorded for each current test patient. The authors compared the outcome frequency of having VTE [VTE(+)] in patients with a pretest probability estimate of <2.5% by attribute matching, compared with a value of 0 from the Wells score. Results:, The five data sets included 10,734 patients, and 747 (7.0%, 95% confidence interval [CI] = 6.5% to 7.5%) were VTE(+) within 45 days. The pretest probability estimate for PE was <2.5% in 2,975 of 10,734 (27.7%) patients, and within this subset, the observed frequency of VTE(+) was 48 of 2,975 (1.6%, 95% CI = 1.2% to 2.1%). The lowest possible Wells score (0) was observed in 3,412 (31.7%) patients, and within this subset, the observed frequency of VTE(+) was 79 of 3,412 (2.3%, 95% CI = 1.8% to 2.9%) patients. Conclusions:, Attribute matching categorizes over one-quarter of patients tested for PE as having a pretest probability of <2.5%, and the observed rate of VTE within 45 days in this subset was <2.5%. ACADEMIC EMERGENCY MEDICINE 2010; 17:133,141 © 2010 by the Society for Academic Emergency Medicine [source] Thromboprophylaxis for hospitalized medical patients: A Multicenter Qualitative study,,JOURNAL OF HOSPITAL MEDICINE, Issue 5 2009Deborah Cook MD Abstract BACKGROUND: Observational studies have documented that medical patients infrequently receive venous thromboembolism (VTE) prevention. OBJECTIVE: To understand the barriers to, and facilitators of, optimal thromboprophylaxis. PATIENTS: Hospitalized medical patients. DESIGN: We conducted in-depth interviews with 15 nurses, 6 pharmacists, 12 physicians with both clinical and managerial experience, and 3 hospital administrators. SETTING: One university-affiliated and 2 community hospitals. INTERVENTION: Interviews were audiotaped and transcribed verbatim. Transcripts were reviewed and interpreted independently in duplicate. MEASUREMENT: Analysis was conducted using grounded theory. RESULTS: Physicians and pharmacists affirmed that evidence supporting heparin is strong and understood. Clinicians, particularly nurses, reported that mobilization was important, but were uncertain about how much mobilization was enough. Participants believed that depending on individual physicians for VTE prevention is insufficient. The central finding was that multidisciplinary care was also perceived as a barrier to effective VTE prevention because it can lead to unclear accountability by role confusion. Participants believed that a comprehensive, systems approach was necessary. Suggestions included screening and risk-stratifying all patients, preprinted orders at hospital admission that are regularly reevaluated, and audit and feedback programs. Patient or family-mediated reminders, and administrative interventions, such as hiring more physiotherapists and profiling thromboprophylaxis in hospital accreditation, were also endorsed. CONCLUSIONS: Universal consideration of thromboprophylaxis finds common ground in multidisciplinary care. However, results of this qualitative study challenge the conviction that either individual physician efforts or multidisciplinary care are sufficient for optimal prevention. To ensure exemplary medical thromboprophylaxis, clinicians regarded coordinated, systemwide processes, aimed at patients, providers, and administrators as essential. Journal of Hospital Medicine 2009;4:269,275. © 2009 Society of Hospital Medicine. [source] Curriculum development: The venous thromboembolism quality improvement resource roomJOURNAL OF HOSPITAL MEDICINE, Issue 2 2006Sylvia McKean MD Abstract BACKGROUND The role of the hospitalist has evolved over the last decade, with hospitalists increasingly being asked to lead systems-based initiatives to improve the quality of inpatient care. The educational strategy of the Society of Hospital Medicine (SHM) includes development of practice-based resources to support hospitalist-led improvement in clinically important measures of hospital care quality. OBJECTIVE To develop a resource at the SHM Web site to present quality improvement (QI) principles for systems-based care in the hospital and to help individual hospitalists improve specific patient outcomes. DESIGN The SHM defined the role of the hospitalist in QI, performed an assessment of the educational needs of hospitalists, and executed a Web-based educational strategy to address these needs. The organization identified the most common cause of preventable inpatient deaths, hospital-acquired venous thromboembolism (VTE), and prioritized the need to improve prophylaxis. RESULTS This new resource at the SHM Web site presents principles for conducting QI in the hospital. To enable learning that is practice based, the VTE Quality Improvement Resource Room (QI RR) features Ask the Expert, an interactive discussion community, and an original Improvement Workbook, a downloadable project outline and tutorial that hospitalists can use to guide and document steps in an effort aimed at reducing hospital-acquired VTE. CONCLUSIONS This QI resource serves as a template for the development of subsequent hospital-based resources. User feedback will refine the QI RR and its format so that similar offerings can target other significant inpatient problems. Additional research is needed to evaluate learning and the clinical impact of this quality improvement resource on hospital performance measures and patient outcomes. Journal of Hospital Medicine 2006;1:124,132. © 2006 Society of Hospital Medicine. [source] Do anticoagulants improve survival in patients presenting with venous thromboembolism?JOURNAL OF INTERNAL MEDICINE, Issue 6 2003J. Kelly Abstract. Anticoagulants have been available since around 1940 and have become the standard of treatment for venous thromboembolism (VTE) for over four decades. However, as with other treatments which became established before the evidence-based era, there is a paucity of evidence from randomized controlled trials validating their effectiveness in preventing the most feared complication of VTE, recurrent fatal pulmonary embolism (PE). Only two such trials have been performed, the results of which conflict. The bulk of data supporting their use are derived from three sources. First, studies of thromboprophylaxis, and comparisons of shorter and longer courses of anticoagulants in high-risk patients with established VTE have clearly demonstrated their effectiveness in primary and late secondary prevention. Given that heparin has an immediate onset of action, anticoagulants should therefore also be effective in early secondary prevention, the proposed mechanism of action in the acute treatment of VTE. Secondly, studies of inadequately treated patients have consistently shown higher recurrence rates than in those adequately treated. Finally, comparisons of outcomes in untreated and treated historical series, and of untreated historical series to treated series in the modern era have shown substantially lower rates of fatal PE in anticoagulated patients. Because these differences are so marked, harmonize with our current understanding of the mechanism of action of anticoagulants and are supported by other evidence, it is much more likely that they at least partly reflect the effectiveness of anticoagulants as opposed to being explicable purely in terms of accumulated biases and a changing distribution of disease severity. [source] Li-Deficient, Off-Congruent MgO:LiNbO3 Crystals Prepared by Postgrown Li-Poor Vapor Transport Equilibration for Integrated OpticsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2010De-Long Zhang Li-deficient, off-congruent Z -cut MgO:LiNbO3 (MgO:LN) crystals for integrated optics were prepared by carrying out postgrown Li-poor vapor transport equilibration (VTE) treatments on congruently grown MgO (5 mol% in melt):LiNbO3 plates at 1100°C for durations ranging from 40 to 395 h. Secondary ion mass spectrometry analysis, surface ordinary refractive index measurement, and neutron activation analysis were carried out on the VTE crystals to verify that the Mg and Nb ions did not diffuse out of the crystal during the VTE procedure and their distributions over the whole plate retain its homogeneity. The VTE duration dependence of the Li2O content reduction was determined using gravimetric method, and the crystalline phase was by powder X-ray diffraction. The results show that the Li2O content decreases with a prolonged VTE and the Li2O content reduction in the saturation regime is about 2.9 mol%. All of the VTE crystals still retain the LN phase, and Li-vacancy and NbLi are the major defects in the VTE crystal. OH absorption study reveals that the doped MgO concentration is below the photorefractive threshold for all VTE crystals. The optical absorption edge (OAE) of the VTE-treated MgO:LN was also measured as a function of the VTE duration. On the basis of the known Li2O content and measured OAE, the photon-energy fit reported previously, valid for the evaluation of Li2O content in a pure LN, is corrected for the Li-poor VTE-treated MgO:LNs. Finally, the applicability of the Li-deficient off-congruent MgO:LN crystals prepared by the Li-poor VTE method is demonstrated by characterizing the optical damage and Er diffusion properties of a single-mode Ti:MgO:Er:LiNbO3 strip waveguide fabricated on an Li-poor VTE-prepared MgO:LN crystal. [source] Patients with a first symptomatic unprovoked deep vein thrombosis are at higher risk of recurrent venous thromboembolism than patients with a first unprovoked pulmonary embolismJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 9 2010M. J. KOVACS Summary.,Background:,Previous studies are mixed as to whether patients with unprovoked pulmonary embolism (PE) have a higher rate of venous thromboembolism (VTE) recurrence after anticoagulation is discontinued than patients with unprovoked deep vein thrombosis (DVT). Objectives:,To determine whether patients with unprovoked PE have a higher rate of VTE recurrence than patients with unprovoked DVT in a prospective multicenter cohort study. Patients/Methods:,Six hundred and forty-six patients with a first episode of symptomatic unprovoked VTE were treated with heparin and subsequent oral anticoagulation for 5,7 months, and were followed every 6 months for recurrent VTE after their anticoagulant therapy was discontinued. Results:,Of 646 patients, 194 had isolated PE, 339 had isolated DVT, and 113 had both DVT and PE. After a mean of 18 months of follow-up, there were 91 recurrent VTE events (9.5% annualized risk of recurrent VTE in the total population). The crude recurrent VTE rate for the isolated PE, isolated DVT and DVT and PE groups were 7.7%, 16.5% and 17.7%, respectively. The relative risk of recurrent VTE for isolated DVT vs. isolated PE was 2.1 (95% confidence interval 1.2,3.7). Conclusions:,This study has demonstrated that patients with a first episode of unprovoked isolated DVT are 2.1 times more likely to have a recurrent VTE episode than patients with a first episode of unprovoked isolated PE. These findings need to be considered when determining the optimal duration of anticoagulant therapy for patients with unprovoked VTE. [source] Sex, age and normal post-anticoagulation D-dimer as risk factors for recurrence after idiopathic venous thromboembolism in the Prolong study extensionJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 9 2010B. COSMI Summary.,Background:,The PROLONG randomized study showed that patients with an abnormal D-dimer after anticoagulation suspension for a first unprovoked episode of venous thromboembolism (VTE) benefited from anticoagulation resumption. Patients with normal D-dimer after anticoagulation suspension had a low recurrence rate (4.4% patient,years) but their anticoagulation optimal duration remained uncertain. Objectives:,To assess whether sex and age, in combination with normal D-dimer, are risk factors for VTE recurrence in patients enrolled in the PROLONG study extended follow-up. Methods:,D-dimer was measured at 1 month after anticoagulation suspension. Patients with a normal D-dimer did not resume anticoagulants, whereas patients with an abnormal D-dimer were randomized either to resume or not anticoagulants. Primary outcome was recurrent VTE. Results:,After excluding patients resuming anticoagulants for abnormal D-dimer, recurrences were higher in males than females [7.4% patient-years , 47/639 vs. 4.3% patient-years , 27/626; hazard ratio (HR) = 1.7; P = 0.027] and in patients aged 65 or older than in younger patients (8.4% patient-years , 50/598 vs. 3.6% patient-years , 24/667; HR = 2.1; P = 0.003). In patients with normal D-dimer and younger than 65, recurrences were higher in males than in females (5.1% vs. 0.4% patient,years; adjusted HR = 10.6; P = 0.023) and both females and males aged 65 years or older had more recurrences (6.6% and 8.1% patient-years, respectively, adjusted HR: 16.0; P = 0.008 and 16.0; P = 0.008, respectively) than females younger than 65. Conclusions:,In patients with idiopathic VTE and a normal D-dimer at 1 month after anticoagulation suspension, females younger than 65 had a very low risk of recurrence. [source] Recurrent venous thromboembolism after surgery-provoked versus unprovoked thromboembolismJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 5 2010R. H. WHITE Summary.,Background: The incidence of recurrent venous thromboembolism (VTE) varies depending on the nature of the initial provoking risk factor(s). Objectives: To compare the incidence and time course of recurrent VTE after unprovoked VTE vs. VTE provoked by nine different types of surgery. Methods: Retrospective analysis of linked California hospital and emergency department discharge records. Between 1997 and 2007, all surgery-provoked VTE cases had a first-time VTE event diagnosed within 60 days after undergoing a major operation. The incidence of recurrent VTE was compared during specified follow-up periods by matching each surgery-provoked case with three unprovoked cases based on age, race, gender, VTE event, calendar year and co-morbidity. Results: The 4-year Kaplan,Meier cumulative incidence of recurrent VTE was 14.7% (95%CI: 14.2,15.1) in the matched unprovoked VTE group vs. 7.6% (CI: 7.0,8.2) in 11 797 patients with surgery-provoked VTE (P < 0.001). The overall risk reduction was 48%, which ranged from 64% lower risk (P < 0.001) after coronary bypass surgery to 25% lower risk (P = 0.06) after disc surgery. The risk of recurrent VTE 1,5 years after the index event was significantly lower in the surgery group (HR = 0.47, CI: 0.41,0.53). Within the surgery-provoked group, the risk of recurrent VTE was similar in men and women (HR = 1.0, CI: 0.8,1.3). Conclusions: The risk of recurrent VTE after surgery-provoked VTE was approximately 50% lower than after unprovoked VTE, confirming the view that provoked VTE is associated with a lower risk of recurrent VTE. However, there was appreciable heterogeneity in the relative risk of recurrent VTE associated with different operations. [source] Air pollution and hospitalization for venous thromboembolic disease in ChileJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 4 2010R. E. DALES See also Mannucci PM. Fine particulate: it matters. This issue, pp 659,61; Bonzini M, Tripodi A, Artoni A, Tarantini L, Marinelli B, Bertazzi PA, Apostoli P, Baccarelli A. Effects of inhalable particulate matter on blood coagulation. This issue, pp 662,8. Summary.,Background:,Ambient air pollution is a risk factor for stroke and myocardial infarction, possibly because of alterations in coagulation that influence the arterial circulation. Whether air pollution influences diseases associated with peripheral venous thrombogenesis remains largely unknown. Objectives: To determine the association between air pollution and venous thromboembolic disease (VTE) in a sample of the general population. Methods: A time-series analysis was used to test the association between daily air pollution and VTE hospitalizations in Santiago between 2001 and 2005. Results were adjusted for long-term trends, day of the week and average daily humidex. Results: From a population of 5.4 million, there were, on average, 2.3 admissions for VTE per day. Pooled estimates of relative risk (RR) [95% confidence interval (CI)] of hospitalization for venous disease were: 1.07 (1.05, 1.09) for a 58.4 p.p.b. increase in ozone (O3); 1.06 (1.02, 1.09) for a 5.85 p.p.b. increase in sulphur dioxide (SO2); 1.08 (1.03, 1.12) for a 29.25 ,g/m3 increase in nitrogen dioxide (NO2); and 1.05 (1.03, 1.06) for a 20.02 ,g/m3 increase in particulate matter , 2.5 ,m in mean aerodynamic diameter (PM2.5). For pulmonary embolism (PE) results were: 1.10 (1.07, 1.13) for O3; 1.05 (1.02, 1.08) for SO2; 1.07 (1.04, 1.09) for NO2; and 1.05(1.03, 1.06) for PM2.5, respectively. Conclusion: Air pollution appears to be a risk factor for venous thrombosis and PE, a disease with a significant fatality rate. [source] Venous thromboembolism in malignant gliomasJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 2 2010E. O. JENKINS Summary., Malignant gliomas are associated with a very high risk of venous thromboembolism (VTE). While many clinical risk factors have previously been described in brain tumor patients, the risk of VTE associated with newer anti-angiogenic therapies such as bevacizumab in these patients remains unclear. When VTE occurs in this patient population, concern regarding the potential for intracranial hemorrhage complicates management decisions regarding anticoagulation, and these patients have a worse prognosis than their VTE-free counterparts. Risk stratification models identifying patients at high risk of developing VTE along with predictive plasma biomarkers may guide the selection of eligible patients for primary prevention with pharmacologic thromboprophylaxis. Recent studies exploring disordered coagulation, such as increased expression of tissue factor (TF), and tumorigenic molecular signaling may help to explain the increased risk of VTE in patients with malignant gliomas. [source] Physician compliance with advanced electronic alerts for preventing venous thromboembolism among hospitalized medical patientsJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 8 2009N. KUCHER Summary.,Background: Worldwide, more than half of the hospitalized medical patients at high risk do not receive venous thromboembolism (VTE) prophylaxis. Although VTE among hospitalized patients at risk is reduced with electronic alerts (eAlerts), the majority of eAlerts are being ignored by the responsible physician. Methods: We investigated physician compliance with an advanced eAlert system in 1027 (age 59 ± 17 years) hospitalized medical patients. A continuously flashing non-interruptive eAlert, visible to all healthcare professionals, was issued in the electronic patient chart 6 h after admission if the physician did not order prophylaxis. Results: The rate of appropriate prophylaxis increased from 44% before to 76% after the implementation of the eAlert system. Although the patients whose physicians cared for , 20 patients during the study period had a more frequent physician response to the eAlert than patients whose physicians cared for fewer patients (69% vs. 40%, P < 0.001), they received appropriate prophylaxis less often (72% vs. 81%, P = 0.016). After adjustment for significant patient predictors of appropriate prophylaxis, including cancer, age, duration of hospital stay, and thrombocytopenia, patients whose physicians cared for , 20 patients during the study period were less likely to receive appropriate prophylaxis (odds ratio 0.65, 95% confidence interval 0.44,0.96; P = 0.032) than patients whose physicians cared for fewer patients. Conclusions: The introduction of an advanced eAlert system accompanied by continuing medical education for the prevention of VTE resulted in a substantial increase in the rate of appropriate prophylaxis among hospitalized medical patients. However, many eAlerts may cause decreased physician compliance owing to ,alert fatigue'. [source] Smoking and venous thromboembolism: a Danish follow-up studyJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 8 2009M. T. SEVERINSEN Summary.,Background: Large-scale prospective studies are needed to assess whether smoking is associated with venous thromboembolism (VTE) (i.e. deep venous thrombosis and pulmonary embolism) independently of established risk factors. Objective: To investigate the association between smoking and the risk of VTE among middle-aged men and women. Methods: From 1993 to 1997, 27 178 men and 29 875 women, aged 50,64 years and born in Denmark, were recruited into the Danish prospective study ,Diet, Cancer and Health'. During follow-up, VTE cases were identified in the Danish National Patient Registry. Medical records were reviewed and only verified VTE cases were included in the study. Baseline data on smoking and potential confounders were included in gender stratified Cox proportional hazard models to asses the association between smoking and the risk of VTE. The analyses were adjusted for alcohol intake, body mass index, physical activity, and in women also for use of hormone replacement therapy. Results: During follow-up, 641 incident cases of VTE were verified. We found a positive association between current smoking and VTE, with a hazard ratio of 1.52 (95% CI, 1.15,2.00) for smoking women and 1.32 (95% CI, 1.00,1.74) for smoking men, and a positive dose-response relationship. Former smokers had the same hazard as never smokers. Conclusions: Smoking was an independent risk factor for VTE among middle-aged men and women. Former smokers have the same risk of VTE as never smokers, indicating acute effects of smoking, and underscoring the potential benefits of smoking cessation. [source] Body mass index and mortality in patients with acute venous thromboembolism: findings from the RIETE registryJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 4 2008R. BARBA Summary.,Background:,There is little information on the influence of body mass index (BMI) on mortality in patients with acute venous thromboembolism (VTE). Patients and methods:,RIETE is an ongoing registry of consecutive patients with symptomatic, objectively confirmed, acute VTE. We examined the association between BMI and mortality during the first 3 months of therapy. Results:,Of the 10 114 patients enrolled as of March 2007: 153 (1.5%) were underweight (BMI < 18.5); 2882 (28%) had a normal weight (BMI 18.5,24.9); 4327 (43%) were overweight (BMI 25.0,30); and 2752 (27%) were obese (BMI > 30). The overweight and obese patients were significantly older, and were less likely to have had cancer, recent immobility or renal insufficiency. After 3 months of therapy their death rates were 28%, 12%, 6.2% and 4.2%, respectively. In multivariate analysis, the relative risks for death after adjusting for confounding variables including age, cancer, renal insufficiency or idiopathic VTE were: 2.1 (95% CI, 1.5,2.7); 1.0 (reference); 0.6 (95% CI, 0.5,0.7); and 0.5 (95% CI, 0.4,0.6), respectively. The rates of fatal pulmonary embolism (2.0%, 2.1%, 1.2% and 0.8%, respectively) also decreased with BMI. There were no differences in the rate of fatal bleeding, but patients who were underweight had an increased incidence of major bleeding complications (7.2% vs. 2.7%; odds ratio, 2.7; 95% CI, 1.4,5.1). Conclusions:,Obese patients with acute VTE have less than half the mortality rate when compared with normal BMI patients. This reduction in mortality rates was consistent among all subgroups and persisted after multivariate adjustment. [source] Partial factor IXa inhibition with TTP889 for prevention of venous thromboembolism: an exploratory studyJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 3 2008B. I. ERIKSSON Summary.,Background:,Inhibitors of factor (F) IXa show potent antithrombotic activity with a low risk of bleeding in preclinical models. We investigated the anticoagulant potential of oral TTP889, a small molecule that inhibits up to 90% of FIXa activity at therapeutic doses, using a clinical model of extended prophylaxis in hip fracture surgery (HFS). Methods:,In this multicenter, randomized, double-blind study, 261 patients received oral TTP889 (300 mg once daily) or placebo starting 6,10 days after HFS, and standard thromboprophylaxis for 5,9 days. Treatment was continued for 3 weeks and all patients then underwent mandatory bilateral venography. The primary efficacy outcome was venous thromboembolism (VTE; venographic or symptomatic deep vein thrombosis or pulmonary embolism) during treatment, and it was evaluated centrally by an independent adjudication panel. The main safety outcome was bleeding (major, clinically relevant non-major, and minor events). Results:,Two hundred and twelve patients with an evaluable venogram were included in the efficacy analysis. The primary efficacy outcome occurred in 32.1% (35/109) of patients who had been allocated TTP889, and 28.2% (29/103) of patients on placebo (P = 0.58). There were no major bleeding events, and only two clinically relevant non-major bleeding events with TTP889. Conclusion:,Partial FIXa inhibition with TTP889 300 mg daily was not effective for extended prevention of VTE after standard prophylaxis for up to 9 days. Coupled with the low incidence of bleeding episodes, this suggests a lack of antithrombotic potential. Further investigation of TTP889 in different clinical settings is needed. (Clinical trial registration information URL: http://www.clinicaltrials.gov. Unique identifier: NCT00119457) . [source] Thromboprophylaxis rates in US medical centers: success or failure?JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 8 2007A. AMIN Summary.,Background:,As hospitalized medical patients may be at risk of venous thromboembolism (VTE), evidence-based guidelines are available to help physicians assess patients' risk for VTE, and to recommend prophylaxis options. The rate of appropriate thromboprophylaxis use in at-risk medical inpatients was assessed in accordance with the 6th American College of Chest Physicians (ACCP) guidelines.Methods:,Hospital discharge information from the Premier PerspectiveÔ inpatient data base from January 2002 to September 2005 was used. Included patients were 40 years old or more, with a length of hospital stay of 6 days or more, and had no contraindications for anticoagulation. The appropriateness of VTE thromboprophylaxis was determined in seven groups with acute medical conditions by comparing the daily thromboprophylaxis usage, including type of thromboprophylaxis, dosage of anticoagulant and duration of thromboprophylaxis, with the ACCP recommendations.Results:,A total of 196 104 discharges from 227 hospitals met the inclusion criteria. The overall VTE thromboprophylaxis rate was 61.8%, although the appropriate thromboprophylaxis rate was only 33.9%. Of the 66.1% discharged patients who did not receive appropriate thromboprophylaxis, 38.4% received no prophylaxis, 4.7% received mechanical prophylaxis only, 6.3% received an inappropriate dosage, and 16.7% received an inappropriate prophylaxis duration based on ACCP recommendations.Conclusions:,This study highlights the low rates of appropriate thromboprophylaxis in US acute-care hospitals, with two-thirds of discharged patients not receiving prophylaxis in accordance with the 6th ACCP guidelines. More effort is required to improve the use of appropriate thromboprophylaxis in accordance with the ACCP recommendations. [source] A dose escalation study of YM150, an oral direct factor Xa inhibitor, in the prevention of venous thromboembolism in elective primary hip replacement surgeryJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 8 2007B. I. ERIKSSON Summary.,Background:,YM150, a new oral direct factor Xa inhibitor is used as prophylaxis for venous thromboembolism (VTE), a well-known risk after orthopaedic surgery. Objectives:,To assess the safety and efficacy of thromboprophylaxis with YM150 in a dose escalation study. Patients/methods:,Patients (174) undergoing hip replacement surgery were randomized per cohort to oral once daily YM150 or subcutaneous enoxaparin (40 mg daily) in a 4:1 ratio for 7,10 days treatment. The YM150 doses were 3, 10, 30 and 60 mg by sequential four-dose escalation cohorts. The primary endpoint was major and/or clinically relevant non-major bleeding. The incidence of VTE was defined as a composite of verified symptomatic events and/or positive findings at bilateral venography on the last treatment day. An independent adjudication committee evaluated blindly the outcomes of the open-label study. Results:,No major and three clinically relevant non-major bleeds were reported, 1 (2.9%; 95% CI, 0.1,15.1) in the 3 mg and 2 (5.7%; 95% CI, 1.0,18.8) in the 10 mg YM150 dose groups. Of 147 patients (84%) with an evaluable venogram, VTE was observed in 51.9% (95% CI, 31.9,71.4), 38.7% (95% CI, 22.6,57.0), 22.6% (95% CI, 9.7,39.4), and 18.5% (95% CI, 7.5,36.5) in the YM150 dose groups 3, 10, 30 and 60 mg, respectively. A significant YM150 dose-related trend in VTE incidence was found (P=0.006). VTE with enoxaparin was 38.7% (95% CI, 22.6,57.0). Conclusions:,YM150, 10,60 mg daily, starting 6,10 h after primary hip replacement, was shown to be safe, well tolerated and effective. [source] Association between asymptomatic deep vein thrombosis detected by venography and symptomatic venous thromboembolism in patients undergoing elective hip or knee surgeryJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 7 2007D. J. QUINLAN Summary.,Background:,Venography is commonly used to compare the efficacy of different thromboprophylaxis strategies for preventing deep vein thrombosis (DVT) in patients undergoing total hip replacement (THR) or total knee replacement (TKR). Methods:,We explored the relation between asymptomatic DVT and symptomatic venous thromboembolism (VTE) in patients undergoing THR or TKR treated with standard doses of enoxaparin (30 mg b.i.d. or 40 mg o.d.) by comparing the incidence of asymptomatic DVT in venographic studies with the incidence of symptomatic VTE in studies where venography was not performed. Results:,In 10 venographic studies involving 5796 patients, the incidence of asymptomatic DVT after THR was 13.2% [95% CI, 12.2,14.2%] and after TKR was 38.1% (95% CI, 35.5,40.8%). In two studies involving 3500 patients who did not undergo venography, the 90-day incidence of symptomatic VTE after THR was 2.7% (95% CI, 2.1,3.4%) and after TKR was 1.8% (95% CI, 0.9,2.7%). For every symptomatic VTE in THR studies where venography was not performed there were five asymptomatic DVTs in the venographic studies; for TKR, the ratio was 1:21. The incidence of asymptomatic DVT and the symptomatic VTE/asymptomatic DVT ratio was influenced by the venogram reading committee (Gothenburg vs. Hamilton: total DVT after THR, 19.5% vs. 8.7%, P < 0.0001; for TKR, 42.7% vs. 27.2%, P < 0.0001). Conclusions:,Comparisons across trials show a consistent relation between asymptomatic venographic DVT in patients undergoing elective THR or TKR surgery and symptomatic VTE in patients not undergoing venography. Differences exist in the strength of the relation depending on the type of surgery and the venogram reading committee. [source] High risk for venous thromboembolism in diabetics with hyperosmolar state: comparison with other acute medical illnessesJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 6 2007C. R. KEENAN Summary.,Background:,Diabetes mellitus is generally not recognized as an important risk factor for venous thromboembolism (VTE). However, clinical observations and case reports have suggested that patients with diabetes and hyperosmolarity may be at increased risk for VTE. Objectives:,To determine the risk of VTE in patients hospitalized for diabetes with hyperosmolar state compared to patients with other acute medical illnesses. Patients/methods:,The California Patient Discharge Data Set was used to determine the incidence of first-time VTE in all patients admitted between 1995 and 2000 for diabetes with hyperosmolarity and 11 other acute medical conditions. Proportional hazard modeling was used to adjust for age, race, gender, and prior hospitalization within 3 months. Results:,Among 2859 patients with diabetes and hyperosmolarity, 34 (1.2%) developed VTE during the hospitalization and 14 (0.5%) developed VTE within 91 days after discharge. In an adjusted multivariate model comparing the risk of VTE to cases with depression, patients with hyperosmolarity had a significantly higher risk of VTE [hazard ratio (HR) = 16.3; 95% confidence interval (CI): 10,25] comparable to the risk associated with sepsis (HR = 19.3; 95% CI: 13,29) or acute connective tissue disease (HR = 21; 95% CI: 15,31). Compared to uncomplicated diabetes, patients with hyperosmolarity had a significantly higher risk of VTE (HR = 3.0; 95% CI: 2.1,4.5) whereas patients with ketoacidosis were not at higher risk (HR = 1.2; 95% CI: 0.8,1.7). Conclusions:,Patients hospitalized for diabetes with hyperosmolarity are at increased risk for developing VTE both during their inpatient stay and in the 3 months after discharge. Thromboprophylaxis in these patients appears warranted, and extended prophylaxis for after hospital discharge should be studied. [source] Frequency of renal impairment, advanced age, obesity and cancer in venous thromboembolism patients in clinical practiceJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 5 2007L. M. COOK Summary.,Background:,Low-molecular-weight heparin (LMWH) dosed by weight is recommended as first-line therapy for the initial treatment of venous thromboembolism (VTE) and as monotherapy for long-term treatment of cancer-related VTE. In ,special populations' such as those with renal impairment or the elderly, weight-based dosing may be excessive, and capping the dose in obese patients may lead to inadequate dosing. Objectives:,We determined the frequency of ,special population' characteristics (renal impairment, advanced age, obesity) and cancer among VTE patients in clinical practice, and assessed whether these characteristics appeared to influence the type and dose of anticoagulants prescribed. Methods:,During 2004,2005, among consecutive patients with VTE at two large Canadian hospitals, the proportions with the above characteristics were calculated and treatments prescribed were determined. Results:,Of 524 VTE patients, 31% were aged > 75 years. Moderate renal impairment [creatinine clearance (CrCl) 30,59 mL min,1] was present in 20% of patients, and severe renal impairment (CrCl < 30 mL min,1) in 5% of patients. LMWH was prescribed to 67% of patients with severe renal impairment and to 83% of patients with moderate renal impairment. Body weight was > 100 kg in 15% of patients. Underdosing of LMWH by > 10% was documented in 36% of such patients compared with 8% of patients < 100 kg (P < 0.001). Among 26% of patients with active cancer, only one-third were prescribed LMWH monotherapy. Conclusions:,In clinical practice, renal impairment, advanced age, obesity and cancer are frequently present in patients with VTE. A considerable proportion of these patients may not receive the optimal type or dose of medication to treat VTE. [source] Microparticle-associated tissue factor activity: a link between cancer and thrombosis?JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 3 2007M. E. T. TESSELAAR Summary. Background:,Cancer, in particular mucinous adenocarcinoma, is associated with venous thromboembolism (VTE). Tissue factor (TF), initiator of coagulation, plays a central role in the paradigm that clotting and tumor growth form a vicious circle, in which hypercoagulability facilitates the aggressive biology of cancer and vice versa. Expression of TF in tumors is associated with poor differentiation and poor prognosis. Patient/methods:,We investigated the association between clinically manifest VTE and procoagulant properties of circulating microparticles (MP) isolated from blood of unselected pancreatic and breast adenocarcinoma patients' consecutive subjects, who presented with ultrasound or CT-scan confirmed VTE, and healthy subjects. Results:,Patients with disseminated breast and pancreatic cancer had significantly increased levels of MP-associated TF activity compared with healthy controls, subjects with idiopathic acute VTE and non-metastatic cancer patients. Patients with both high MP-associated TF-activity and MP-associated epithelial mucin (MUC1) had a lower survival rate at 3,9 months follow-up than those with low TF-activity and no MUC1 expression: the likelihood of survival was 0.42 (95% CI: 0.19, 0.94) for an individual with these two predictor variables present, after adjustment for other factors (age cohort, type of cancer, VTE) in the Cox proportional hazards model. Conclusions:,Our results suggest an important role for MP-associated TF and MUC1 in the pathogenesis of thrombosis in disseminated mucinous adenocarcinoma patients. Future studies should reveal the mechanism underlying the observed associations. [source] Type and location of venous thromboembolism in patients with factor V Leiden or prothrombin G20210A and in those with no thrombophiliaJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 1 2007I. MARTINELLI Summary.,Background: Patients with factor (F) V Leiden or the prothrombin G20210A polymorphism are at increased risk of developing deep vein thrombosis (DVT). On the other hand, the risk of developing pulmonary embolism (PE) appears to be low in carriers of FV Leiden, perhaps because of a lower tendency to develop iliofemoral DVT than non-carriers. For prothrombin G20210A, data are scanty and controversial. Methods: The clinical manifestations (isolated DVT, DVT and PE, and isolated PE), the extension of DVT, and the presence of transient risk factors were retrospectively investigated in 115 patients with heterozygous FV Leiden, 87 with prothrombin G20210A and 200 with no thrombophilia marker. Results: Isolated symptomatic PE was less prevalent in patients with FV Leiden (6%) than in those with prothrombin G20210A (21%) and no thrombophilia (23%) (P > 0.0001). The rate of distal DVT was higher in patients with no thrombophilia (16% vs. 7% for FV Leiden and 6% for prothrombin G20210A) (P = 0.02). No difference in the incidence of PE from distal and proximal DVT, the extension of proximal DVT and the type of transient risk factors for venous thromboembolism (VTE) was found in the three groups. Patients with prothrombin G20210A had a younger age at their first VTE (24 years, P < 0.0001) and a higher rate of DVT accompanying PE (P = 0.04) than those with FV Leiden or no thrombophilia. Conclusions: Carriers of prothrombin G20210A, unlike those of FV Leiden, have an increased risk of developing isolated PE. This difference was not explained by a different rate of distal DVT, extension of proximal DVT, or distribution of transient risk factors in the two groups. Patients with prothrombin G20210A have more severe clinical manifestations than those with FV Leiden or no thrombophilia. [source] | |||||||||||||||||||||||||||||||