American Society of Hematology 2018 guidelines for management of venous thromboembolism: prophylaxis for hospitalized and nonhospitalized medical patients

Incidence of venous thromboembolism in hospitalized patients with COVID-19

BACKGROUND

Coronavirus disease 2019 (COVID-19) can lead to systemic coagulation activation and thrombotic complications.

OBJECTIVES

To investigate the incidence of objectively confirmed venous thromboembolism (VTE) in hospitalized patients with COVID-19.

METHODS

Single-center cohort study of 198 hospitalized patients with COVID-19.

RESULTS

Seventy-five patients (38%) were admitted to the intensive care unit (ICU). At time of data collection, 16 (8%) were still hospitalized and 19% had died. During a median follow-up of 7 days (IQR, 3-13), 39 patients (20%) were diagnosed with VTE of whom 25 (13%) had symptomatic VTE, despite routine thrombosis prophylaxis. The cumulative incidences of VTE at 7, 14 and 21 days were 16% (95% CI, 10-22), 33% (95% CI, 23-43) and 42% (95% CI 30-54) respectively. For symptomatic VTE, these were 10% (95% CI, 5.8-16), 21% (95% CI, 14-30) and 25% (95% CI 16-36). VTE appeared to be associated with death (adjusted HR, 2.4; 95% CI, 1.02-5.5). The cumulative incidence of VTE was higher in the ICU (26% (95% CI, 17-37), 47% (95% CI, 34-58), and 59% (95% CI, 42-72) at 7, 14 and 21 days) than on the wards (any VTE and symptomatic VTE 5.8% (95% CI, 1.4-15), 9.2% (95% CI, 2.6-21), and 9.2% (2.6-21) at 7, 14, and 21 days).

CONCLUSIONS

The observed risk for VTE in COVID-19 is high, particularly in ICU patients, which should lead to a high level of clinical suspicion and low threshold for diagnostic imaging for DVT or PE. Future research should focus on optimal diagnostic and prophylactic strategies to prevent VTE and potentially improve survival.

JAK Inhibitors Safety in Ulcerative Colitis: Practical Implications

Janus kinase inhibitors [JAKi] are a new class of small molecule drugs that modulate inflammatory pathways by blocking one or more JAK receptors, and are increasingly being used in the treatment of immune-mediated diseases. Tofacitinib, a non-selective JAKi, is now approved for moderate-to-severe ulcerative colitis [UC] that is refractory or intolerant to tumour necrosis factor inhibitors [TNFi]. Whereas tofacitinib is associated with the advantages of oral administration, rapid onset of action, and lack of immunogenicity over TNFi, there are many safety considerations to take into account such as the risk of thromboembolism, infections, and hyperlipidaemia: each with specific nuances pertaining to prevention and monitoring strategies. Considerations such as pregnancy, breastfeeding, and history of malignancy also are to be navigated with utmost caution, given that very few data are available for guidance. With the use of JAKi in the real world progressively over time, safety implications will become more lucid, including caveats pertaining to JAK selectivity and gut-selective JAKi, as well as mechanistic data pertaining to adverse effects. This Viewpoint serves as a practical guide for clinicians managing inflammatory bowel disease [IBD] patients to navigate safety concerns around JAKi, including preventive and monitoring strategies.

Thromboembolic events and Covid-19

The novel Corona virus infection (Covid-19) first identified in China in December 2019 has rapidly progressed in pandemic leading to significant mortality and unprecedented challenge for healthcare systems. Although the clinical spectrum of Covid-19 is variable, acute respiratory failure and systemic coagulopathy are common in severe Covid-19 patients. Lung is an important target of the SARS-CoV-2 virus causing eventually acute respiratory distress syndrome associated to a thromboinflammatory state. The cytokinic storm, thromboinflammation and pulmonary tropism are the bedrock of tissue lesions responsible for acute respiratory failure and for prolonged infection that may lead to multiple organ failure and death. The thrombogenicity of this infectious disease is illustrated by the high frequency of thromboembolic events observed even in Covid-19 patients treated with anticoagulation. Increased D-Dimers, a biomarker reflecting activation of hemostasis and fibrinolysis, and low platelet count (thrombocytopenia) are associated with higher mortality in Covid-19 patients. In this review, we will summarize our current knowledge on the thromboembolic manifestations, the disturbed hemostatic parameters, and the thromboinflammatory conditions associated to Covid-19 and we will discuss the modalities of anticoagulant treatment or other potential antithrombotic options.

Prevention of Venous Thromboembolism in 2020 and Beyond

Venous thromboembolism (VTE) is the third most common cause of vascular mortality worldwide and comprises deep-vein thrombosis (DVT) and pulmonary embolism (PE). In this review, we discuss how an understanding of VTE epidemiology and the results of thromboprophylaxis trials have shaped the current approach to VTE prevention. We will discuss modern thromboprophylaxis as it pertains to genetic risk factors, exogenous hormonal therapies, pregnancy, surgery, medical hospitalization, cancer, and what is known thus far about VTE in COVID-19 infection.

Low venous thromboembolism incidence in high risk medical patients in an Israeli hospital. Can risk assessment be extrapolated to different populations?

BACKGROUND

Guidelines recommend venous thromboembolism (VTE) prophylaxis in hospitalized medical patients with Padua prediction score (PPS) ≥4 points. This recommendation is based on the high risk of symptomatic VTE observed among these patients in the Italian PPS derivation study, and the fivefold risk reduction with VTE-prophylaxis. This study aims to assess the incidence of VTE in high risk medical patients in a medium sized hospital in Israel.

METHOD

In this retrospective cohort study, data was collected of all medical patients hospitalized between January and June 2014. Patients were classified into low and high risk groups according to their PPS score, and according to whether they received anticoagulant thromboprophylaxis for VTE. Patients were further randomly selected to compare high risk patients that did or did not receive anticoagulant thromboprophylaxis. We further compared VTE incidence in high and low risk patients not treated with thromboprophylaxis. A search was conducted for diagnoses of venous thromboembolism and death during hospitalization and the following 90 days.

RESULTS

568 high risk patients (PPS ≥4 points) were included, 284 treated with prophylactic anticoagulation and 284 not. There were no VTE events in either group. There was no difference in mortality. A total of 642 non anticoagulated patients were randomly selected, 474 low risk and 168 high risk. There were no VTE events in either group.

CONCLUSIONS

The risk of VTE appears to be very low in our study, suggesting that among medical patients with PPS ≥4, the risk of VTE may differ dramatically between populations.

Predicting postdischarge hospital-associated venous thromboembolism among medical patients using a validated mortality risk score derived from common biomarkers

BACKGROUND

Discharged medical patients are at risk for venous thromboembolism (VTE). It is difficult to identify which discharged patients would benefit from extended duration thromboprophylaxis. The Intermountain Risk Score is a prediction score derived from discrete components of the complete blood cell count and basic metabolic panel and is highly predictive of 1-year mortality. We sought to ascertain if the Intermountain Risk Score might also be predictive of 90-day postdischarge hospital-associated VTE (HA-VTE).

METHODS

We applied the Intermountain Risk Score to 60 064 medical patients who survived 90 days after discharge and report predictiveness for HA-VTE. Area under the receiver operating curve analyses were performed. We then assessed whether the Intermountain Risk Score improved prediction of 2 existing VTE risk assessment models.

RESULTS

The Intermountain Risk Score poorly predicted HA-VTE (area under the curve = 0.58; 95% confidence interval [CI], 0.56-0.60). Each clinical risk assessment model was superior to the Intermountain Risk Score (UTAH area under the curve, 0.63; Kucher area under the curve, 0.62; Intermountain Risk Score area under the curve, 0.58; P < .001 for each comparison). Adding the Intermountain Risk Score to these scores did not substantially improve the performance of either risk assessment model (UTAH + Intermountain Risk Score, 0.65; Kucher + Intermountain Risk Score, 0.64).

CONCLUSION

The Intermountain Risk Score demonstrated poor predictiveness for HA-VTE when compared to existing risk assessment models. Adding the Intermountain Risk Score to existing risk assessment models did not improve upon either risk assessment model alone to justify the added complexity.

Management of Cardiovascular Disease Patients With Confirmed or Suspected COVID-19 in Limited Resource Settings

In this paper, we provide recommendations on the management of cardiovascular disease (CVD) among patients with confirmed or suspected coronavirus disease (COVID-19) to facilitate the decision making of healthcare professionals in low resource settings. The emergence of novel coronavirus disease, also known as Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2), has presented an unprecedented global challenge for the healthcare community. The ability of SARS-CoV-2 to get transmitted during the asymptomatic phase and its high infectivity have led to the rapid transmission of COVID-19 beyond geographic regions, leading to a pandemic. There is concern that COVID-19 is cardiotropic, and it interacts with the cardiovascular system on multiple levels. Individuals with established CVD are more susceptible to severe COVID-19. Through a consensus approach involving an international group this WHF statement summarizes the links between cardiovascular disease and COVID-19 and present some practical recommendations for the management of hypertension and diabetes, acute coronary syndrome, heart failure, rheumatic heart disease, Chagas disease, and myocardial injury for patients with COVID-19 in low-resource settings. This document is not a clinical guideline and it is not intended to replace national clinical guidelines or recommendations. Given the rapidly growing burden posed by COVID-19 illness and the associated severe prognostic implication of CVD involvement, further research is required to understand the potential mechanisms linking COVID-19 and CVD, clinical presentation, and outcomes of various cardiovascular manifestations in COVID-19 patients.

Venous thromboembolism research priorities: A scientific statement from the American Heart Association and the International Society on Thrombosis and Haemostasis

Venous thromboembolism (VTE) is a major cause of morbidity and mortality. The impact of the Surgeon General's Call to Action in 2008 has been lower than expected given the public health impact of this disease. This scientific statement highlights future research priorities in VTE, developed by experts and a crowdsourcing survey across 16 scientific organizations. At the fundamental research level (T0), researchers need to identify pathobiologic causative mechanisms for the 50% of patients with unprovoked VTE and better understand mechanisms that differentiate hemostasis from thrombosis. At the human level (T1), new methods for diagnosing, treating, and preventing VTE will allow tailoring of diagnostic and therapeutic approaches to individuals. At the patient level (T2), research efforts are required to understand how foundational evidence impacts care of patients (eg, biomarkers). New treatments, such as catheter-based therapies, require further testing to identify which patients are most likely to experience benefit. At the practice level (T3), translating evidence into practice remains challenging. Areas of overuse and underuse will require evidence-based tools to improve care delivery. At the community and population level (T4), public awareness campaigns need thorough impact assessment. Large population-based cohort studies can elucidate the biologic and environmental underpinings of VTE and its complications. To achieve these goals, funding agencies and training programs must support a new generation of scientists and clinicians who work in multidisciplinary teams to solve the pressing public health problem of VTE.

Venous thromboembolism in SARS-CoV-2 patients: only a problem in ventilated ICU patients, or is there more to it?

Venous thromboembolism (VTE) is a well-known complication in hospitalised patients [1–5]. Risk factors include older age, obesity, immobilisation, active malignancy, systemic inflammatory response syndrome (SIRS), (major) surgery, thrombophilia and a history of thromboembolism [2, 5]. In 1884, Rudolph Virchow first described the underlying pathophysiological mechanisms, which consist of endothelial cell dysfunction/inflammation, low blood flow and blood hypercoagulability. Current guidelines recommend the use of thromboprophylaxis in acutely ill medical patients who are at high risk for VTE (Padua score ≥4, IMPROVE (International Medical Prevention Registry on Venous Thromboembolism) score ≥2) [6]. However, in medical practice, less than half of the patients at risk receive adequate thromboprophylaxis [4].

Insidious venous thromboembolism (VTE) is mainly a problem in ICU-ventilated SARS-CoV-2 patients, while patients in the general ward, treated with thromboprophylaxis (0.5 mg·kg−1), had a low incidence of insidious VTE https://bit.ly/2Yl8jft

Thromboembolism and anticoagulant therapy during the COVID-19 pandemic: interim clinical guidance from the anticoagulation forum

Coronavirus disease 2019 (COVID-19) is a viral infection that can, in severe cases, result in cytokine storm, systemic inflammatory response and coagulopathy that is prognostic of poor outcomes. While some, but not all, laboratory findings appear similar to sepsis-associated disseminated intravascular coagulopathy (DIC), COVID-19- induced coagulopathy (CIC) appears to be more prothrombotic than hemorrhagic. It has been postulated that CIC may be an uncontrolled immunothrombotic response to COVID-19, and there is growing evidence of venous and arterial thromboembolic events in these critically ill patients. Clinicians around the globe are challenged with rapidly identifying reasonable diagnostic, monitoring and anticoagulant strategies to safely and effectively manage these patients. Thoughtful use of proven, evidence-based approaches must be carefully balanced with integration of rapidly emerging evidence and growing experience. The goal of this document is to provide guidance from the Anticoagulation Forum, a North American organization of anticoagulation providers, regarding use of anticoagulant therapies in patients with COVID-19. We discuss in-hospital and post-discharge venous thromboembolism (VTE) prevention, treatment of suspected but unconfirmed VTE, laboratory monitoring of COVID-19, associated anticoagulant therapies, and essential elements for optimized transitions of care specific to patients with COVID-19.

Thromboembolism and anticoagulant therapy during the COVID-19 pandemic: interim clinical guidance from the anticoagulation forum

Coronavirus disease 2019 (COVID-19) is a viral infection that can, in severe cases, result in cytokine storm, systemic inflammatory response and coagulopathy that is prognostic of poor outcomes. While some, but not all, laboratory findings appear similar to sepsis-associated disseminated intravascular coagulopathy (DIC), COVID-19- induced coagulopathy (CIC) appears to be more prothrombotic than hemorrhagic. It has been postulated that CIC may be an uncontrolled immunothrombotic response to COVID-19, and there is growing evidence of venous and arterial thromboembolic events in these critically ill patients. Clinicians around the globe are challenged with rapidly identifying reasonable diagnostic, monitoring and anticoagulant strategies to safely and effectively manage these patients. Thoughtful use of proven, evidence-based approaches must be carefully balanced with integration of rapidly emerging evidence and growing experience. The goal of this document is to provide guidance from the Anticoagulation Forum, a North American organization of anticoagulation providers, regarding use of anticoagulant therapies in patients with COVID-19. We discuss in-hospital and post-discharge venous thromboembolism (VTE) prevention, treatment of suspected but unconfirmed VTE, laboratory monitoring of COVID-19, associated anticoagulant therapies, and essential elements for optimized transitions of care specific to patients with COVID-19.

International recommendations on the diagnosis and treatment of acquired hemophilia A

Acquired hemophilia A (AHA), a rare bleeding disorder caused by neutralizing autoantibodies against coagulation factor VIII (FVIII), occurs in both men and women without a previous history of bleeding. Patients typically present with an isolated prolonged activated partial thromboplastin time due to FVIII deficiency. Neutralizing antibodies (inhibitors) are detected using the Nijmegen-modified Bethesda assay. Approximately 10% of patients do not present with bleeding and, therefore, a prolonged activated partial thromboplastin time should never be ignored prior to invasive procedures. Control of acute bleeding and prevention of injuries that may provoke bleeding are top priorities in patients with AHA. We recommend treatment with bypassing agents, including recombinant activated factor VII, activated prothrombin complex concentrate, or recombinant porcine FVIII in bleeding patients. Autoantibody eradication can be achieved with immunosuppressive therapy, including corticosteroids, cyclophosphamide and rituximab, or combinations thereof. The median time to remission is 5 weeks, with considerable interindividual variation. FVIII activity at presentation, inhibitor titer and autoantibody isotype are prognostic markers for remission and survival. Comparative clinical studies to support treatment recommendations for AHA do not exist; therefore, we provide practical consensus guidance based on recent registry findings and the authors' clinical experience in treating patients with AHA.

Caring for Critically Ill Adults With Coronavirus Disease 2019 in a PICU: Recommendations by Dual Trained Intensivists

OBJECTIVE

In the midst of the severe acute respiratory syndrome coronavirus 2 pandemic, which causes coronavirus disease 2019, there is a recognized need to expand critical care services and beds beyond the traditional boundaries. There is considerable concern that widespread infection will result in a surge of critically ill patients that will overwhelm our present adult ICU capacity. In this setting, one proposal to add "surge capacity" has been the use of PICU beds and physicians to care for these critically ill adults.

DESIGN

Narrative review/perspective.

SETTING

Not applicable.

PATIENTS

Not applicable.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The virus's high infectivity and prolonged asymptomatic shedding have resulted in an exponential growth in the number of cases in the United States within the past weeks with many (up to 6%) developing acute respiratory distress syndrome mandating critical care services. Coronavirus disease 2019 critical illness appears to be primarily occurring in adults. Although pediatric intensivists are well versed in the care of acute respiratory distress syndrome from viral pneumonia, the care of differing aged adult populations presents some unique challenges. In this statement, a team of adult and pediatric-trained critical care physicians provides guidance on common "adult" issues that may be encountered in the care of these patients and how they can best be managed in a PICU.

CONCLUSIONS

This concise scientific statement includes references to the most recent and relevant guidelines and clinical trials that shape management decisions. The intention is to assist PICUs and intensivists in rapidly preparing for care of adult coronavirus disease 2019 patients should the need arise.

Prevention of thrombotic risk in hospitalized patients with COVID-19 and hemostasis monitoring

COVID-19 is an infection induced by the SARS-CoV-2 coronavirus, and severe forms can lead to acute respiratory distress syndrome (ARDS) requiring intensive care unit (ICU) management. Severe forms are associated with coagulation changes, mainly characterized by an increase in D-dimer and fibrinogen levels, with a higher risk of thrombosis, particularly pulmonary embolism. The impact of obesity in severe COVID-19 has also been highlighted.In this context, standard doses of low molecular weight heparin (LMWH) may be inadequate in ICU patients, with obesity, major inflammation, and hypercoagulability. We therefore urgently developed proposals on the prevention of thromboembolism and monitoring of hemostasis in hospitalized patients with COVID-19.Four levels of thromboembolic risk were defined according to the severity of COVID-19 reflected by oxygen requirement and treatment, the body mass index, and other risk factors. Monitoring of hemostasis (including fibrinogen and D-dimer levels) every 48 h is proposed. Standard doses of LMWH (e.g., enoxaparin 4000 IU/24 h SC) are proposed in case of intermediate thrombotic risk (BMI < 30 kg/m2, no other risk factors and no ARDS). In all obese patients (high thrombotic risk), adjusted prophylaxis with intermediate doses of LMWH (e.g., enoxaparin 4000 IU/12 h SC or 6000 IU/12 h SC if weight > 120 kg), or unfractionated heparin (UFH) if renal insufficiency (200 IU/kg/24 h, IV), is proposed. The thrombotic risk was defined as very high in obese patients with ARDS and added risk factors for thromboembolism, and also in case of extracorporeal membrane oxygenation (ECMO), unexplained catheter thrombosis, dialysis filter thrombosis, or marked inflammatory syndrome and/or hypercoagulability (e.g., fibrinogen > 8 g/l and/or D-dimers > 3 μg/ml). In ICU patients, it is sometimes difficult to confirm a diagnosis of thrombosis, and curative anticoagulant treatment may also be discussed on a probabilistic basis. In all these situations, therapeutic doses of LMWH, or UFH in case of renal insufficiency with monitoring of anti-Xa activity, are proposed.In conclusion, intensification of heparin treatment should be considered in the context of COVID-19 on the basis of clinical and biological criteria of severity, especially in severely ill ventilated patients, for whom the diagnosis of pulmonary embolism cannot be easily confirmed.

COVID-19 and Thrombotic or Thromboembolic Disease: Implications for Prevention, Antithrombotic Therapy, and Follow-Up: JACC State-of-the-Art Review

Coronavirus disease-2019 (COVID-19), a viral respiratory illness caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), may predispose patients to thrombotic disease, both in the venous and arterial circulations, because of excessive inflammation, platelet activation, endothelial dysfunction, and stasis. In addition, many patients receiving antithrombotic therapy for thrombotic disease may develop COVID-19, which can have implications for choice, dosing, and laboratory monitoring of antithrombotic therapy. Moreover, during a time with much focus on COVID-19, it is critical to consider how to optimize the available technology to care for patients without COVID-19 who have thrombotic disease. Herein, the authors review the current understanding of the pathogenesis, epidemiology, management, and outcomes of patients with COVID-19 who develop venous or arterial thrombosis, of those with pre-existing thrombotic disease who develop COVID-19, or those who need prevention or care for their thrombotic disease during the COVID-19 pandemic.

COVID-19 and Thrombotic or Thromboembolic Disease: Implications for Prevention, Antithrombotic Therapy, and Follow-Up: JACC State-of-the-Art Review

Coronavirus disease-2019 (COVID-19), a viral respiratory illness caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), may predispose patients to thrombotic disease, both in the venous and arterial circulations, because of excessive inflammation, platelet activation, endothelial dysfunction, and stasis. In addition, many patients receiving antithrombotic therapy for thrombotic disease may develop COVID-19, which can have implications for choice, dosing, and laboratory monitoring of antithrombotic therapy. Moreover, during a time with much focus on COVID-19, it is critical to consider how to optimize the available technology to care for patients without COVID-19 who have thrombotic disease. Herein, the authors review the current understanding of the pathogenesis, epidemiology, management, and outcomes of patients with COVID-19 who develop venous or arterial thrombosis, of those with pre-existing thrombotic disease who develop COVID-19, or those who need prevention or care for their thrombotic disease during the COVID-19 pandemic.

Antithrombotic Therapy in Hereditary Hemorrhagic Telangiectasia: Real-World Data from the Gemelli Hospital HHT Registry

Although Hereditary Hemorrhagic Telangiectasia (HHT) is characterized by an overwhelming bleeding propensity, patients with this disease may also present medical conditions that require antithrombotic therapy (AT). However, precise information on indications, dosage, duration, effectiveness, and safety of AT in HHT patients is lacking. We performed a retrospective analysis of the HHT Registry of our University Hospital and found 26 patients who received AT for a total of 30 courses (19 courses of anticoagulant therapy and 11 courses of antiplatelet therapy). Indications to treatments included: atrial fibrillation, venous thrombosis and pulmonary embolism, heart valve replacement, retinal artery occlusion, secondary prevention after either stroke or myocardial infarction, and thromboprophylaxis for surgery. The total time of exposure to antiplatelet therapy was 385 months and to anticoagulant therapy 169 months. AT was generally well tolerated, with no fatal bleedings and no significant changes in hemoglobin levels. However, we found three major bleedings, with an incidence rate of 6.5 per 100 patients per year. When only patients treated with anticoagulants were considered, the incidence rate of major bleedings increased to 21.6 per 100 patients per year. Our study indicates that major bleeding may occur in HHT patients receiving AT, with a substantially increased rate in those treated with anticoagulants. Further studies are needed to fully estimate the tolerability of antithrombotic drugs in HHT.

How to Build the Plane While Flying: VTE/PE Thromboprophylaxis Clinical Guidelines for COVID-19 Patients

Over the years, the practice of medicine has evolved from authority-based to experience-based to evidence-based with the introduction of the scientific process, clinical trials, and outcomes-based data analysis (Tebala GD. Int J Med Sci. 2018;15(12):1397-1405). The time required to perform the necessary randomized controlled trials, a systematic literature review, and meta-analysis of these trials to then create, accept, promulgate, and educate the practicing clinicians to use the evidence-based clinical guidelines is typically measured in years. When the severe acute respiratory syndrome novel coronavirus-2 (SARS-nCoV-2) pandemic commenced in Wuhan, China at the end of 2019, there were few available clinical guidelines to deploy, let alone adapt and adopt to treat the surge of coronavirus disease 2019 (COVID-19) patients. The aim of this study is to first explain how clinical guidelines, on which bedside clinicians have grown accustomed, can be created in the midst of a pandemic, with an evolving scientific understanding of the pathophysiology of the hypercoagulable state. The second is to adapt and adopt current venous thromboembolism diagnostic and treatment guidelines, while relying on the limited available observational reporting of COVID-19 patients to create a comprehensive clinical guideline to treat COVID-19 patients.

Validation of risk assessment models predicting venous thromboembolism in acutely ill medical inpatients: A cohort study

BACKGROUND

Because hospital-acquired venous thromboembolism (VTE) represents a frequent cause of preventable deaths in medical inpatients, identifying at-risk patients requiring thromboprophylaxis is critical. We aimed to externally assess the Caprini, IMPROVE, and Padua VTE risk scores and to compare their performance to advanced age as a stand-alone predictor.

METHODS

We performed a retrospective analysis of patients prospectively enrolled in the PREVENU trial. Patients aged 40 years and older, hospitalized for at least 2 days on a medical ward were consecutively enrolled and followed for 3 months. Critical ill patients were not recruited. Patients diagnosed with VTE within 48 hours from admission, or receiving full dose anticoagulant treatment or who underwent surgery were excluded. All suspected VTE and deaths occurring during the 3-month follow-up were adjudicated by an independent committee. The three scores were retrospectively assessed. Body mass index, needed for the Padua and Caprini scores, was missing in 44% of patients.

RESULTS

Among 14 910 eligible patients, 14 660 were evaluable, of which 1.8% experienced symptomatic VTE or sudden unexplained death during the 3-month follow-up. The area under the receiver operating characteristic curves (AUC) were 0.60 (95% confidence interval [CI] 0.57-0.63), 0.63 (95% CI 0.60-0.66) and 0.64 (95% CI 0.61-0.67) for Caprini, IMPROVE, and Padua scores, respectively. None of these scores performed significantly better than advanced age as a single predictor (AUC 0.61, 95% CI 0.58-0.64).

CONCLUSION

In our study, Caprini, IMPROVE, and Padua VTE risk scores have poor discriminative ability to identify not critically ill medical inpatients at risk of VTE, and do not perform better than a risk evaluation based on patient's age alone.

Safety and Efficacy of High-Dose Unfractionated Heparin Versus High-Dose Enoxaparin for Venous Thromboembolism Prevention in Morbidly Obese Hospitalized Patients

BACKGROUND

Venous thromboembolism is a cause of morbidity and mortality in hospitalized patients, and morbid obesity increases this risk. Various prophylaxis dosing strategies have been investigated. However, it is unclear if high-fixed dose enoxaparin or high-fixed dose unfractionated heparin thromboprophylaxis is optimal for minimizing the incidence of major bleeding and reducing hospital-acquired venous thromboembolism.

METHODS

A single-center retrospective observational study was conducted in hospitalized patients who were morbidly obese (body mass index ≥40 kg/m²) and who received either high-fixed dose enoxaparin (40 mg every 12 hours) or unfractionated heparin (7500 units every 8 hours) for venous thromboembolism prophylaxis. Co-primary outcomes included incidence of major bleeding and venous thromboembolism diagnosed during hospitalization. Predictors of major bleeding were evaluated by multivariable regression.

RESULTS

In the 305 patients included (n = 190 unfractionated heparin, n = 115 enoxaparin), the incidence of major bleeding was significantly higher in the unfractionated heparin group (odds ratio [OR] 1.85, 95% confidence interval [CI] 1.07-3.13; P = 0.025), with no significant difference in the incidence of venous thromboembolism diagnosed during hospitalization. The only independent predictors of major bleeding were intensive care acuity (OR 3.32, 95% CI 1.91-5.78; P <0.001) and selection of unfractionated heparin rather than enoxaparin for venous thromboembolism prophylaxis (OR 2.16, 95% CI 1.22-3.82; P = 0.008).

CONCLUSION

High-fixed dose unfractionated heparin for venous thromboembolism prophylaxis may lead to a higher risk of major bleeding events compared with high-fixed dose enoxaparin in patients who are morbidly obese.

Dose-adjusted enoxaparin thromboprophylaxis in hospitalized cancer patients: a randomized, double-blinded multicenter phase 2 trial

Hospitalized patients with cancer are at an increased risk of developing venous thromboembolism (VTE). The recommendation for routine pharmacologic thromboprophylaxis in hospitalized patients with cancer to prevent VTE is based on extrapolation of results from noncancer cohorts. There are limited data to support the efficacy and safety of fixed-dose low-molecular-weight heparin (LMWH) regimens in high-risk hospitalized patients with cancer. We conducted a randomized, double-blinded, phase 2 trial in hospitalized patients with active cancer at high risk of developing VTE based on Padua risk score. Patients were randomly assigned to fixed-dose enoxaparin (40 mg daily) vs weight-adjusted enoxaparin (1 mg/kg daily) during hospitalization. The primary objectives were to evaluate the safety of dose-adjusted enoxaparin and evaluate the incidence of VTE with fixed-dose enoxaparin. Blinded clinical assessments were performed at day 14, and patients randomly assigned to fixed-dose enoxaparin subsequently underwent a bilateral lower extremity ultrasound. A total of 50 patients were enrolled and randomized. The median weight of patients enrolled in weight-adjusted enoxaparin arm was 76 kg (range, 60.9-124.5 kg). There were no major hemorrhages or symptomatic VTE in either arm. At time of completion of the blinded clinical assessment, there was only 1 incidentally identified pulmonary embolus that occurred in the weight-adjusted arm. In the group randomly assigned to fixed-dose enoxaparin who subsequently underwent surveillance ultrasound, the cumulative incidence of DVT was 22% (90% binomial confidence interval, 0%-51.3%). This phase 2 trial confirms a high incidence of asymptomatic VTE among high-risk hospitalized patients with cancer and that weight-adjusted LMWH thromboprophylaxis is feasible and well-tolerated. This trial was registered at www.clinicaltrials.gov as #NCT02706249.

Methodology for the American Society of Hematology VTE guidelines: current best practice, innovations, and experiences

BACKGROUND

Methods for the development of clinical guidelines have advanced dramatically over the past 2 decades to strive for trustworthiness, transparency, user-friendliness, and rigor. The American Society of Hematology (ASH) guidelines on venous thromboembolism (VTE) have followed these advances, together with application of methodological innovations.

OBJECTIVE

In this article, we describe methods and methodological innovations as a model to inform future guideline enterprises by ASH and others to achieve guideline standards. Methodological innovations introduced in the development of the guidelines aim to address current challenges in guideline development.

METHODS

We followed ASH policy for guideline development, which is based on the Guideline International Network (GIN)-McMaster Guideline Development Checklist and current best practices. Central coordination, specialist working groups, and expert panels were established for the development of 10 VTE guidelines. Methodological guidance resources were developed to guide the process across guidelines panels. A methods advisory group guided the development and implementation of methodological innovations to address emerging challenges and needs.

RESULTS

The complete set of VTE guidelines will include >250 recommendations. Methodological innovations include the use of health-outcome descriptors, online voting with guideline development software, modeling of pathways for diagnostic questions, application of expert evidence, and a template manuscript for publication of ASH guidelines. These methods advance guideline development standards and have already informed other ASH guideline projects.

CONCLUSIONS

The development of the ASH VTE guidelines followed rigorous methods and introduced methodological innovations during guideline development, striving for the highest possible level of trustworthiness, transparency, user-friendliness, and rigor.

Thromboembolism and anticoagulant therapy during the COVID-19 pandemic: interim clinical guidance from the anticoagulation forum

Coronavirus disease 2019 (COVID-19) is a viral infection that can, in severe cases, result in cytokine storm, systemic inflammatory response and coagulopathy that is prognostic of poor outcomes. While some, but not all, laboratory findings appear similar to sepsis-associated disseminated intravascular coagulopathy (DIC), COVID-19- induced coagulopathy (CIC) appears to be more prothrombotic than hemorrhagic. It has been postulated that CIC may be an uncontrolled immunothrombotic response to COVID-19, and there is growing evidence of venous and arterial thromboembolic events in these critically ill patients. Clinicians around the globe are challenged with rapidly identifying reasonable diagnostic, monitoring and anticoagulant strategies to safely and effectively manage these patients. Thoughtful use of proven, evidence-based approaches must be carefully balanced with integration of rapidly emerging evidence and growing experience. The goal of this document is to provide guidance from the Anticoagulation Forum, a North American organization of anticoagulation providers, regarding use of anticoagulant therapies in patients with COVID-19. We discuss in-hospital and post-discharge venous thromboembolism (VTE) prevention, treatment of suspected but unconfirmed VTE, laboratory monitoring of COVID-19, associated anticoagulant therapies, and essential elements for optimized transitions of care specific to patients with COVID-19.

Venous thromboembolism (VTE) risk stratification in general medical patients at an academic medical center

Hospital-acquired venous thromboembolism (VTE) is still a concern for general medical patients. Pharmacologic prophylaxis can reduce VTE incidence, but there is the potential for adverse effects. Therefore, determining which patients should receive VTE prophylaxis via risk scoring tools is essential. Limited evidence exists for the ideal venous thromboembolism risk assessment model (RAM) in hospitalized medical patients, as compared to other hospitalized patient subgroups such as surgical patients. The primary objective was to investigate the utilization and appropriateness of our institution-based VTE RAM and comparison to the Padua Prediction Score (PPS). This would allow for a gauge of provider risk assessment accuracy as well as appropriate predictive potential of the PPS or whether an alternative to the PPS should be considered. A total of 330 adult general medicine patients were included in this retrospective chart review. When compared to our institution-based VTE RAM, providers predominately stratified patients at a higher VTE risk than the institution-based VTE RAM. VTE incidence was 0.3%, which was lower than predicted. Significant discordance exists between providers' VTE risk assessment and that predicted by RAMs. Our institution-based VTE RAM appears comparable to PPS; however, it was not being utilized by providers, resulting in potentially unnecessary use of pharmacologic prophylaxis. The most appropriate venous thromboembolism risk assessment model for general medicine patients is undetermined. Our providers generally assess patients as moderate or high VTE risk, despite our institution-based RAM which typically recommends a lower risk category than provider selection. Because of provider risk assessment, more patients received pharmacologic VTE prophylaxis than would have been recommended by the RAM, which might correlate to the low incidence of VTE which was < 0.5%, although bleeding complications were not assessed in this study. A prospective study utilizing the Padua Prediction Score (or similar RAM) in general medicine patients is warranted in order to decipher the best method of predicting VTE risk.

Health risk of travel for chronic kidney disease patients

The number of people with chronic kidney disease (CKD) has increased and so has their demand for travel. However, the health risk posed by travel in these patients is unclear. Few reports document the travel risk in CKD and dialysis patients. The aim of this study is to summarize the existing evidence of the influence of travel on risks in CKD patients. We aim to describe the association between the impact of travel risks and patients with CKD. A detailed review of recent literature was performed by reviewing PubMed, Google Scholar, and Ichushi Web from the Japan Medical Abstracts Society. Screened involved the following keywords: “traveler's thrombosis,” “venous thromboembolism,” “deep vein thrombosis,” “altitude sickness,” “traveler's diarrhea,” “jet lag syndrome,” “melatonin,” with “chronic kidney disease” only, or/and “dialysis.” We present a narrative review summary of the literature from these screenings. The increased prevalence of thrombosis among travelers with CKD is related to a decrease in the estimated glomerular filtration rate and an increase in urine protein levels. CKD patients who remain at high altitudes are at an increased risk for progression of CKD, altitude sickness, and pulmonary edema. Traveler's diarrhea can become increasingly serious in patients with CKD because of decreased immunity. Microbial substitution colitis is also common in CKD patients. Moreover, time differences and disturbances in the circadian rhythm increase cardiovascular disease events for CKD patients. The existing literature shows that travel-related conditions pose an increased risk for patients with CKD.

Call to Action to Prevent Venous Thromboembolism in Hospitalized Patients: A Policy Statement From the American Heart Association

Venous thromboembolism (VTE) is a major preventable disease that affects hospitalized inpatients. Risk stratification and prophylactic measures have good evidence supporting their use, but multiple reasons exist that prevent full adoption, compliance, and efficacy that may underlie the persistence of VTE over the past several decades. This policy statement provides a focused review of VTE, risk scoring systems, prophylaxis, and tracking methods. From this summary, 5 major areas of policy guidance are presented that the American Heart Association believes will lead to better implementation, tracking, and prevention of VTE events. They include performing VTE risk assessment and reporting the level of VTE risk in all hospitalized patients, integrating preventable VTE as a benchmark for hospital comparison and pay-for-performance programs, supporting appropriations to improve public awareness of VTE, tracking VTE nationwide with the use of standardized definitions, and developing a centralized data steward for data tracking on VTE risk assessment, prophylaxis, and rates.

Extended Venous Thromboembolism Prophylaxis in Medically Ill Patients: An NATF Anticoagulation Action Initiative

Hospitalized patients with acute medical illnesses are at risk for venous thromboembolism (VTE) during and after a hospital stay. Risk factors include physical immobilization and underlying pathophysiologic processes that activate the coagulation pathway and are still present after discharge. Strategies for optimal pharmacologic VTE thromboprophylaxis are evolving, and recommendations for VTE prophylaxis can be further refined to protect high-risk patients after hospital discharge. An early study of extended VTE prophylaxis with a parenteral agent in medically ill patients yielded inconclusive results with regard to efficacy and bleeding. In the Acute Medically Ill VTE Prevention with Extended Duration Betrixaban (APEX) trial, extended use of betrixaban halved symptomatic VTE, decreased hospital readmission, and reduced stroke and major adverse cardiovascular events compared with standard enoxaparin prophylaxis. Based on findings from APEX, the Food and Drug Administration approved betrixaban in 2017 for extended VTE prophylaxis in acute medically ill patients. In the Reducing Post-Discharge Venous Thrombo-Embolism Risk (MARINER) study, extended use of rivaroxaban halved symptomatic VTE in high-risk medical patients compared with placebo. In 2019, rivaroxaban was approved for extended thromboprophylaxis in high-risk medical patients, thus making available a new strategy for in-hospital and post-discharge VTE prevention. To address the critical unmet need for VTE prophylaxis in medically ill patients at the time of hospital discharge, the North American Thrombosis Forum (NATF) is launching the Anticoagulation Action Initiative, a comprehensive consensus document that provides practical guidance and straightforward, patient-centered recommendations for VTE prevention during hospitalization and after discharge.

Cancer-associated venous thromboembolism: Treatment and prevention with rivaroxaban

Cancer-associated venous thromboembolism (VTE) is a frequent, potentially life-threatening event that complicates cancer management. Anticoagulants are the cornerstone of therapy for the treatment and prevention of cancer-associated thrombosis (CAT); factor Xa-inhibiting direct oral anticoagulants (DOACs; apixaban, edoxaban, and rivaroxaban), which have long been recommended for the treatment of VTE in patients without cancer, have been investigated in this setting. The first randomized comparisons of DOACs against low-molecular-weight heparin for the treatment of CAT indicated that DOACs are efficacious in this setting, with findings reflected in recent updates to published guidance on CAT treatment. However, the higher risk of bleeding events (particularly in the gastrointestinal tract) with DOACs highlights the need for appropriate patient selection. Further insights will be gained from additional studies that are ongoing or awaiting publication. The efficacy and safety of DOAC thromboprophylaxis in ambulatory patients with cancer at a high risk of VTE have also been assessed in placebo-controlled randomized controlled trials of apixaban and rivaroxaban. Both studies showed efficacy benefits with DOACs, but both studies also showed a nonsignificant increase in major bleeding events while on treatment. This review summarizes the evidence base for rivaroxaban use in CAT, the patient profile potentially most suited to DOAC use, and ongoing controversies under investigation. We also describe ongoing studies from the CALLISTO (Cancer Associated thrombosis-expLoring soLutions for patients through Treatment and Prevention with RivarOxaban) program, which comprises several randomized clinical trials and real-world evidence studies, including investigator-initiated research.

Venous and arterial thromboembolic complications in COVID-19 patients admitted to an academic hospital in Milan, Italy

Background

Few data are available on the rate and characteristics of thromboembolic complications in hospitalized patients with COVID-19.

Methods

We studied consecutive symptomatic patients with laboratory-proven COVID-19 admitted to a university hospital in Milan, Italy (13.02.2020–10.04.2020). The primary outcome was any thromboembolic complication, including venous thromboembolism (VTE), ischemic stroke, and acute coronary syndrome (ACS)/myocardial infarction (MI). Secondary outcome was overt disseminated intravascular coagulation (DIC).

Results

We included 388 patients (median age 66 years, 68% men, 16% requiring intensive care [ICU]). Thromboprophylaxis was used in 100% of ICU patients and 75% of those on the general ward. Thromboembolic events occurred in 28 (7.7% of closed cases; 95%CI 5.4%–11.0%), corresponding to a cumulative rate of 21% (27.6% ICU, 6.6% general ward). Half of the thromboembolic events were diagnosed within 24 h of hospital admission. Forty-four patients underwent VTE imaging tests and VTE was confirmed in 16 (36%). Computed tomography pulmonary angiography (CTPA) was performed in 30 patients, corresponding to 7.7% of total, and pulmonary embolism was confirmed in 10 (33% of CTPA). The rate of ischemic stroke and ACS/MI was 2.5% and 1.1%, respectively. Overt DIC was present in 8 (2.2%) patients.

Conclusions

The high number of arterial and, in particular, venous thromboembolic events diagnosed within 24 h of admission and the high rate of positive VTE imaging tests among the few COVID-19 patients tested suggest that there is an urgent need to improve specific VTE diagnostic strategies and investigate the efficacy and safety of thromboprophylaxis in ambulatory COVID-19 patients.

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COVID-19 is characterized by coagulation activation and endothelial dysfunction. Few data are available on thromboembolic complications.

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We studied symptomatic patients with laboratory-proven COVID-19 admitted to a university hospital in Milan, Italy (13.02-10.04.2020).

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Venous and arterial thromboembolic events occurred in 8% of hospitalized patients (cumulative rate 21.0%) and 50% of events were diagnosed within 24 h of hospital admission.

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Forty-four (11% of total) patients underwent VTE imaging tests; 16 were positive (36% of tests), suggesting underestimation of thromboembolic complications.

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There is an urgent need to investigate VTE diagnostic strategies and the impact of thromboprophylaxis in ambulatory COVID-19 patients.

Prevention and Treatment of Venous Thromboembolism Associated with Coronavirus Disease 2019 Infection: A Consensus Statement before Guidelines

Coronavirus disease 2019 (COVID-19) has caused a global pandemic in just a few months, causing millions infected. Nearly 20% of COVID-19 patients present severe coagulation abnormalities, which may occur in almost all of the severe and critical ill COVID-19 cases. Concomitant venous thromboembolism (VTE), a potential cause of unexplained deaths, has been frequently reported in COVID-19 cases, but its management is still challenging due to the complexity between antithrombotic therapy and coagulation disorders. Based on frontline practical experience and comprehensive literature review, here a panel of experts and physicians from China and Europe developed an evidence and opinion-based consensus on the prophylaxis and management of VTE associated with COVID-19. This statement aims for clinicians treating COVID-19 and provides practical recommendations in detailed situations, for example, how to choose thromboprophylactic measures for patients with diverse severity of disease and bleeding risk, or which kind of anticoagulant should be prescribed. With limited experience on COVID19-associated VTE, this expert consensus statement should be helpful for clinicians worldwide with specific suggestions.

Should You Treat This Acutely Ill Medical Inpatient With Venous Thromboembolism Chemoprophylaxis?: Grand Rounds Discussion From Beth Israel Deaconess Medical Center

Venous thromboembolism (VTE), which includes both deep venous thrombosis and pulmonary embolism, is a common and potentially fatal condition. Medical inpatients are at high risk for VTE because of immobility as well as acute and chronic illness. Several randomized trials demonstrated that chemoprophylaxis, or low-dose anticoagulation, prevents VTE in selected medical inpatients. The 2018 American Society of Hematology clinical practice guideline on prophylaxis for hospitalized and nonhospitalized medical patients conditionally recommends chemoprophylaxis for non-critically ill medical inpatients, leaving much to the discretion of the treating physician. Here, 2 experts, a hematologist and a hospitalist, reflect on the care of a woman hospitalized with a rheumatologic disorder. They consider the risks and benefits of chemoprophylaxis, discuss VTE risk stratification, and recommend which patients should receive chemoprophylaxis and with which agents.

Improved Benefit Risk Profile of Rivaroxaban in a Subpopulation of the MAGELLAN Study

Acutely ill medical patients are at risk of venous thromboembolism (VTE) and VTE-related mortality during hospitalization and posthospital discharge, but widespread adoption of extended thromboprophylaxis has not occurred. We analyzed a subpopulation within the MAGELLAN study of extended thromboprophylaxis with rivaroxaban to reevaluate the benefit risk profile. We identified 5 risk factors for major and fatal bleeding after a clinical analysis of the MAGELLAN study and analyzed efficacy and safety with these patients excluded (n = 1551). Risk factors included: active cancer, dual antiplatelet therapy at baseline, bronchiectasis/pulmonary cavitation, gastroduodenal ulcer, or bleeding within 3 months before randomization. We evaluated efficacy, safety, and benefit risk using clinically comparable endpoints in the subpopulation. At day 10, rivaroxaban was noninferior to enoxaparin (relative risk [RR] = 0.82, 95% confidence interval [CI] = 0.58-1.15) and at day 35 rivaroxaban was significantly better than enoxaparin/placebo (RR = 0.68, 95% CI = 0.53-0.88) in reducing VTE and VTE-related death. Major bleeding was reduced at day 10 (RR = 2.18, 95% CI = 1.07-4.44 vs 1.19, 95% CI = 0.54-2.65) and at day 35 (2.87, 95% CI = 1.60-5.15 vs 1.48, 95% CI = 0.77-2.84) for MAGELLAN versus this subpopulation, respectively. The benefit risk profile was favorable in this subpopulation treated for 35 days, with the number needed to treat ranging from 55 to 481 and number needed to harm from 455 to 1067 for all pairwise evaluations. Five exclusionary criteria defined a subpopulation of acutely ill medical patients with a positive benefit risk profile for in-hospital and extended thromboprophylaxis with rivaroxaban.

New Paradigms of Extended Thromboprophylaxis in Medically Ill Patients

Extended thromboprophylaxis given to medically ill patients for up to 45 days following an acute hospitalization remains an emerging topic among many hospital-based health care providers. Recent advancements in the field of extended thromboprophylaxis using risk stratification and careful patient selection criteria have led to an improved safety profile of direct oral anticoagulants (DOACs) and established net clinical benefit when given to key patient subgroups at high risk of venous thromboembolism (VTE) and low risk of bleeding. The Food and Drug Administration (FDA) has now approved the DOACs betrixaban and rivaroxaban for both in-hospital and extended thromboprophylaxis in medically ill patients in these key subgroups, which represents more than one-quarter of hospitalized medically ill patients. This has potential to significantly reduce VTE-related morbidity and mortality for these patients. Emerging data also supports reductions in the risk of arterial thromboembolism in medically ill patients with extended thromboprophylaxis post-hospital discharge using DOACs. This article aims to review the most recent concepts of predicting and preventing VTE and to discuss emerging paradigms of extended thromboprophylaxis in hospitalized medically ill patients utilizing an individualized, risk-adapted approach.

Introduction and methods of the evidence-based guidelines for the diagnosis and management of autism spectrum disorder by the Italian National Institute of Health

Background

Autism Spectrum Disorder (ASD) is a neuro-developmental disorder that affects communication and behavior with a prevalence of approximately 1% worldwide. Health outcomes of interventions for ASD are largely Participant Reported Outcomes (PROs). Specific guidelines can help support the best care for people with ASD to optimize these health outcomes but they have to adhere to standards for their development to be trustworthy.

Objective

The goal of this article is to describe the new methodological standards of the Italian National Institute of Health and novel aspects of this guideline development process. This article will serve as a reference standard for future guideline development in the Italian setting.

Methods

We applied the new standards of the Italian National Institute of Health to the two guidelines on diagnosis and management of children/adolescents and adults with ASD, with a focus on the scoping, panel composition, management of conflict of interest, generation and prioritization of research questions, early stakeholders’ involvement, and PROs. Recommendations are based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Evidence-to-Decision frameworks.

Results

Following a public application process, the ISS established two multidisciplinary panels including people with ASD and/or their caregivers. Seventy-nine research questions were identified as potentially relevant for the guideline on children and adolescents with ASD and 31 for the one on adults with ASD. Questions deemed to have the highest priority were selected for inclusion in the guidelines. Other stakeholders valued their early involvement in the process which will largely focus on PROs. The panels then successfully piloted the development of recommendations using the methodological standards and process set by the ISS with a focus on PROs.

Conclusions

In this article, we describe the development of practice guidelines that focus on PROs for the diagnosis and management of ASD based on novel methods for question prioritization and stakeholder involvement. The recommendations allow for the adoption or adaptation to international settings.

Recommendations for VTE Prophylaxis in Medically Ill Patients

Venous thromboembolism (VTE) remains highly prevalent in medically ill patients, and often leads to increased mortality and cost burden during hospitalization and post-discharge. Nearly half of all VTEs occur during or after hospitalization, with pulmonary embolism accounting for 10% of inpatient mortality. Appropriate prophylaxis in high-risk medically ill patients has been shown to reduce risk of VTE and related mortality. Despite current evidence-based guidelines, VTE prophylaxis has been under-used. This owes greatly to ambiguity and concerns related to appropriate patient and prophylactic agent selection, and duration of prophylaxis. Because many acutely ill medical patients have multiple comorbidities, the risk of major bleeding must be considered when choosing to implement pharmacological VTE prophylaxis. Multiple risk assessment models have been developed and validated to help estimate VTE and bleeding risks in this population. While studies have shown that the risk for VTE often extends far beyond hospital discharge, there is no evidence to support extending prophylaxis after hospital discharge. The appropriate selection of VTE prophylaxis requires consideration for cost, availability, patient preference, compliance, and underlying comorbidities. Our paper reviews the current evidence and reasoning for appropriate selection of VTE prophylaxis in acutely medical ill patients, and highlights our own approach and recommendations.

The risk and prevention of venous thromboembolism in the pregnant traveller

BACKGROUND

The average risk of venous thromboembolism (VTE) in long haul travellers is approximately 2.8 per 1000 travellers, which is increased in the presence of other VTE risk factors. In pregnant long-haul travellers, little is known in terms of the absolute risk of VTE in these women and, therefore, there is limited consensus on appropriate thromboprophylaxis in this setting.

OBJECTIVE

This review will provide guidance to allow practitioners to safely minimize the risk of travel-related VTE in pregnant women. The suggestions provided are based on limited data, extrapolated risk estimates of VTE in pregnant travellers and recommendations from published guidelines.

RESULTS

We found that the absolute VTE risk per flight appears to be <1% for the average pregnant or postpartum traveller. In pregnant travellers with a prior history of VTE, a potent thrombophilia or strong antepartum risk factors (e.g. combination of obesity and immobility), the risk of VTE with travel appears to be >1%. Postpartum, the risk of VTE with travel may be >1% for women with thrombophilias (particularly in those with a family history) and other transient risk factors and in women with a prior VTE.

CONCLUSIONS

Based on our findings, we recommend simple measures be taken by all pregnant travellers, such as frequent ambulation, hydration and calf exercises. In those at an intermediate risk, we suggest a consideration of 20-30 mmHg compression stockings. In the highest risk group, we suggest careful consideration for low-molecular-weight heparin thromboprophylaxis. If there are specific concerns, we advise consultation with a thrombosis expert at the nearest local centre.

Patient values and preferences regarding VTE disease: a systematic review to inform American Society of Hematology guidelines

Values and preferences relate to the importance that patients place on health outcomes (eg, bleeding, having a deep venous thrombosis) and are essential when weighing benefits and harms in guideline recommendations. To inform the American Society of Hematology guidelines for management of venous thromboembolism (VTE) disease, we conducted a systematic review of patients' values and preferences related to VTE. We searched Medline, Embase, Cochrane Central Register of Controlled Trials, PsycINFO, and the Cumulative Index to Nursing and Allied Health Literature from inception to April of 2018 (PROSPERO-CRD42018094003). We included quantitative and qualitative studies. We followed Grading of Recommendations Assessment, Development and Evaluation (GRADE) guidance for rating the certainty and presenting findings for quantitative research about the relative importance of health outcomes and a grounded theory approach for qualitative thematic synthesis. We identified 14 quantitative studies (2465 participants) describing the relative importance of VTE-related health states in a widely diverse population of patients, showing overall small to important impact on patients' lives (certainty of the evidence from low to moderate). Additionally, evidence from 34 quantitative studies (6424 participants) and 15 qualitative studies (570 participants) revealed that patients put higher value on VTE risk reduction than on the potential harms of the treatment (certainty of evidence from low to moderate). Studies also suggested a clear preference for oral medication over subcutaneous medication (moderate certainty). The observed variability in health state values may be a result of differences in the approaches used to elicit them and the diversity of included populations rather than true variability in values. This finding highlights the necessity to explore the variability induced by different approaches to ascertain values.