External validation of the IMPROVE-DD risk assessment model for venous thromboembolism among inpatients with COVID-19

Universal clinical decision support tool for thromboprophylaxis in hospitalized COVID-19 patients: post hoc analysis of the IMPROVE-DD cluster randomized trial

BACKGROUND

Inpatient and extended postdischarge thromboprophylaxis of COVID-19 patients remains suboptimal despite antithrombotic guidelines.

OBJECTIVES

To determine whether a novel electronic health record-agnostic clinical decision support (CDS) tool incorporating the International Medical Prevention Registry on Venous Thromboembolism plus D-dimer (IMPROVE-DD) venous thromboembolism (VTE) scores increases appropriate inpatient and extended postdischarge thromboprophylaxis and improves outcomes in COVID-19 inpatients.

METHODS

This post hoc analysis of the IMPROVE-DD cluster randomized trial evaluated thromboprophylaxis CDS among COVID-19 inpatients at 4 New York hospitals between December 21, 2020, and January 21, 2022. Hospitals were randomized 1:1 to CDS (intervention, n = 2) vs no CDS (usual care, n = 2). The primary outcome was rate of appropriate thromboprophylaxis. Secondary outcomes included rates of major thromboembolism, all-cause and VTE-related readmissions and death, major bleeding (MB), and all-cause mortality 30 days after discharge.

RESULTS

Two thousand four hundred fifty-two COVID-19 inpatients were analyzed (CDS, 1355; no CDS, 1097). Mean age was 73.7 ± 9.37 years; 50.1% of participants were male. CDS adoption was 96.8% (intervention group). CDS was associated with increased appropriate at-discharge extended thromboprophylaxis (42.6% vs 28.8%; odds ratio [OR], 1.83; 95% CI, 1.39-2.41; P < .001). CDS was associated with reduced VTE (OR, 0.54; 95% CI, 0.39-0.75; P < .001), arterial thromboembolism (OR, 0.10; 95% CI, 0.01-0.81; P = .01), total thromboembolism (OR, 0.50; 95% CI, 0.36-0.69; P < .001), and 30-day all-cause readmission/death (OR, 0.78; 95% CI, 0.62-0.99; P = .04). There were no differences in MB, VTE-related readmissions/death, or all-cause mortality.

CONCLUSION

Electronic health record-agnostic CDS incorporating IMPROVE-DD VTE scores had high adoption, was associated with increased appropriate at-discharge extended thromboprophylaxis, and reduced thromboembolism and all-cause readmission/death without increasing MB in COVID-19 inpatients.

Prevention of Venous Thromboembolism in Medical Patients with Thrombocytopenia or with Platelet Dysfunction: The Last 10 Years

Current guideline recommendations for primary prophylaxis of venous thromboembolism (VTE) are based on randomized clinical trials that usually exclude subjects at a potentially high risk of bleeding complications. For this reason, no specific guideline is available for thromboprophylaxis in hospitalized patients with thrombocytopenia and/or platelet dysfunction. However, except in patients with absolute contraindications to anticoagulant drugs, antithrombotic prophylaxis should always be considered, for example, in hospitalized cancer patients with thrombocytopenia, especially in those with multiple VTE risk factors. Low platelet number, platelet dysfunction, and clotting abnormalities are also very common in patients with liver cirrhosis, but these patients have a high incidence of portal venous thrombosis, implying that cirrhotic coagulopathy does not fully protect against thrombosis. These patients may benefit from antithrombotic prophylaxis during hospitalization. Patients hospitalized for COVID-19 need prophylaxis, but frequently experience thrombocytopenia or coagulopathy. In patients with antiphospholipid antibodies, a high thrombotic risk is usually present, even in the presence of thrombocytopenia. VTE prophylaxis in high-risk conditions is thus suggested in these patients. At variance with severe thrombocytopenia (< 50,000/mm3), mild/moderate thrombocytopenia (≥ 50,000/mm3) should not interfere with VTE prevention decisions. In patients with severe thrombocytopenia, pharmacological prophylaxis should be considered on an individual basis. Aspirin is not as effective as heparins in lowering the risk of VTE. Studies in patients with ischemic stroke demonstrated that thromboprophylaxis with heparins is safe in these patients also during antiplatelet treatment. The use of direct oral anticoagulants in the prophylaxis of VTE in internal medicine patients has been recently evaluated, but no specific recommendation exists for patients with thrombocytopenia. The need for VTE prophylaxis in patients on chronic treatment with antiplatelet agents should be evaluated after assessing the individual risk of bleeding complications. Finally, the selection of patients who require post-discharge pharmacological prophylaxis remains debated. New molecules currently under development (such as the inhibitors of factor XI) may contribute to improve the risk/benefit ratio of VTE primary prevention in this setting of patients.

Risk Scores in Venous Thromboembolism Guidelines of ESC, ACCP, and ASH: An Updated Review

Venous thromboembolism (VTE) is associated with high morbidity and mortality. Risk scores associated with VTE have been widely used in clinical practice. Among numerous scores published, those included in guidelines are usually typical risk scores which have been extensively validated and globally recognized. This review provides an updated overview of the risk scores associated with VTE endorsed by 3 guidelines which are highly recognized in the field of VTE including the European Society of Cardiology, American College of Chest Physicians, and American Society of Hematology, focusing on the development, modification, validation, and comparison of these scores, to provide a comprehensive and updated understanding of all the classic risk scores associated with VTE to medical readers including but not limited to cardiologists, pulmonologists, hematologists, intensivists, physicians, surgeons, and researchers. Although each score recommended by these guidelines was more or less validated, there may still be room for further improvement. It may still be necessary to seek simpler, more practical, and more universally applicable VTE-related risk scores in the future.

Pulmonary embolism post-Covid-19 infection: physiopathological mechanisms and vascular damage biomarkers

Covid-19 infection is characterized by several acute complications, as well long-term sequelae, mostly sustained by endothelial dysfunction; several studies show that complications as pulmonary embolism (PE) are described both in the acute phase and after negativization. Aim of research was to evaluate anthropometric, bio-humoral, instrumental parameters in a group of patients affected by PE after recent Covid-19 infection compared to PE patients without previous Covid-19 infection. We enrolled 72 consecutive patients (35M, 37F) with acute PE, distinguished in relation to previous acute Covid-19 infection: 54 pts without previous acute Covid-19 infection and 18 pts with previous Covid-19 infection within negativity at least 2 months before PE diagnosis; 44 healthy subjects (21M, 23F) were recruited as control group. Patients who had previously developed Covid-19 needed hospitalization in high percentage (84%); this group showed significantly higher prevalence of diabetes mellitus than Covid-19-free PE patients, reduced serum levels of C-reactive protein, sST2 and PESI score. In post-Covid-19 PE group, we observed higher mean IMPROVE risk score, whereas in Covid-19-free group lower P/F ratio, higher radiological severity, and worse PESI score and severity index. Covid-19 infection affects not just the lung parenchyma but also other organs; endothelial damage plays pivotal role in long-term alterations; in high thrombotic risk group (recent hospitalization due to acute Covid-19 infection), we have described thrombotic complications characterized by persistent prothrombotic state after recovery, highlighted by well-known markers as PCR and D-Dimer as well as novel vascular marker (sST2).

COVID-19-Associated Pulmonary Embolism: Review of the Pathophysiology, Epidemiology, Prevention, Diagnosis, and Treatment

COVID-19 is associated with endothelial activation in the setting of a potent inflammatory reaction and a hypercoagulable state. The end result of this thromboinflammatory state is an excess in thrombotic events, in particular venous thromboembolism. Pulmonary embolism (PE) has been of special interest in patients with COVID-19 given its association with respiratory deterioration, increased risk of intensive care unit admission, and prolonged hospital stay. The pathophysiology and clinical characteristics of COVID-19-associated PE may differ from the conventional non-COVID-19-associated PE. In addition to embolic events from deep vein thrombi, in situ pulmonary thrombosis, particularly in smaller vascular beds, may be relevant in patients with COVID-19. Appropriate prevention of thrombotic events in COVID-19 has therefore become of critical interest. Several changes in viral biology, vaccination, and treatment management during the pandemic may have resulted in changes in incidence trends. This review provides an overview of the pathophysiology, epidemiology, clinical characteristics, and risk factors of COVID-19-associated PE. Furthermore, we briefly summarize the results from randomized controlled trials of preventive antithrombotic therapies in COVID-19, focusing on their findings related to PE. We discuss the acute treatment of COVID-19-associated PE, which is substantially similar to the management of conventional non-COVID-19 PE. Ultimately, we comment on the current knowledge gaps in the evidence and the future directions in the treatment and follow-up of COVID-19-associated PE, including long-term management, and its possible association with long-COVID.

Universal EHRs Clinical Decision Support for Thromboprophylaxis in Medical Inpatients: A Cluster Randomized Trial

Background

Thromboprophylaxis for medically ill patients during hospitalization and postdischarge remains underutilized. Clinical decision support (CDS) may address this need if embedded within workflow, interchangeable among electronic health records (EHRs), and anchored on a validated model.

Objectives

The purpose of this study was to assess the clinical impact of a universal EHR-integrated CDS tool based on the International Medical Prevention Registry on Venous Thromboembolism plus D-Dimer venous thromboembolism model.

Methods

This was a cluster randomized trial of 4 tertiary academic hospitals from December 21, 2020 to January 21, 2022. Inpatients over age 60 with key medical illnesses were eligible. We embedded CDS at admission and discharge. Hospitals were randomized to intervention (CDS; n = 2) vs usual care (n = 2) groups. The primary outcome was rate of appropriate thromboprophylaxis. Secondary outcomes included venous, arterial, and total thromboembolism, major bleeding, and all-cause mortality through 30 days postdischarge.

Results

After exclusions, 10,699 of 19,823 patients were analyzed. Intervention group tool adoption was 77.8%. Appropriate thromboprophylaxis was increased at intervention hospitals, both inpatient (80.1% vs 72.5%, OR: 1.52, 95% CI: 1.39-1.67) and at discharge (13.6% vs 7.5%, OR: 1.93, 95% CI: 1.60-2.33). There were fewer venous (2.7% vs 3.3%, OR: 0.80, 95% CI: 0.64-1.00), arterial (0.25% vs 0.70%, OR: 0.35, 95% CI: 0.19-0.67), and total thromboembolisms (2.9% vs 4.0%, OR: 0.71, 95% CI: 0.58-0.88) at intervention hospitals. Major bleeding was rare and did not differ between groups. Mortality was higher at intervention hospitals (9.1% vs 7.0%, OR: 1.32, 95% CI: 1.15-1.53).

Conclusions

EHR-embedded CDS increased appropriate thromboprophylaxis and reduced thromboembolism without increasing major bleeding in medically ill inpatients. Mortality was higher at intervention hospitals.

A systematic review on post-discharge venous thromboembolism prophylaxis in patients with COVID-19

BACKGROUND

Coronavirus disease of 2019 (COVID-19) is associated with venous thromboembolism (VTE), not only during hospitalization but also after discharge, raising concerns about anticoagulant (AC) use for post-discharge COVID-19 patients. We aimed to systematically review the current literature on the possible benefits or risks regarding extended thromboprophylaxis.

MAIN BODY

We searched related databases from December 1, 2019, to October 6, 2022, including studies on the necessity, duration, and selection of the ideal AC regarding extended thromboprophylaxis for post-discharge COVID-19 patients. The screening of the selected databases led to 18 studies and 19 reviews and guidelines. Studies included 52,927 hospitalized COVID-19 patients, with 19.25% receiving extended thromboprophylaxis. VTE events ranging from 0 to 8.19% (median of 0.7%) occurred in a median follow-up of 49.5 days. All included studies and guidelines, except four studies, recommended post-discharge prophylaxis after an individual risk assessment indicating high thrombotic and low bleeding risk. Studies used risk assessment models (RAMs), clinical evaluation, and laboratory data to identify COVID-19 patients with a high risk of VTE. IMPROVE-DD was the most recommended RAM. Direct oral anticoagulants (DOACs) and low molecular weight heparins (LMWHs) were the most used AC classes.

CONCLUSIONS

Post-discharge prophylaxis for COVID-19 patients is recommended after an individual assessment. The IMPROVE-DD model can help predict VTE risk. After distinguishing patients who need post-discharge AC therapy, DOACs for 30-35 days and LMWHs for 40-45 days can be the drug of choice. Further studies, particularly the results of the ongoing randomized controlled trials (RCTs), are required. Also, to properly handle such patients, every physician should consider lifestyle modification in addition to pharmacological treatment for post-discharge VTE prophylaxis.

Cost-effectiveness analysis of extended thromboprophylaxis with rivaroxaban versus no prophylaxis in high-risk patients after hospitalisation for COVID-19: an economic modelling study

Background

In patients at high risk of thromboembolism who were discharged after hospitalisation due to COVID-19, thromboprophylaxis with rivaroxaban 10 mg/day for 35 days significantly improved clinical outcomes, reducing thrombotic events compared with no post-discharge anticoagulation. The present study aimed to estimate the cost-effectiveness of this anticoagulation strategy.

Methods

Using the database of the MICHELLE trial, we developed a decision tree to estimate the cost-effectiveness of thromboprophylaxis with rivaroxaban 10 mg/day for 35 days versus no thromboprophylaxis in high-risk post-discharge patients for COVID-19 through an incremental cost-effectiveness analysis.

Findings

318 patients in 14 centres in Brazil were enrolled in the primary MICHELLE trial. The mean age was 57.1 years (SD 15.2), 127 (40%) were women, 191 (60%) were men, and the mean body-mass index was 29.7 kg/m2 (SD 5.6). Rivaroxaban 10 mg per day orally for 35 days after discharge decreased the risk of events defined by the primary efficacy outcome by 67% (relative risk 0.33, 95% CI 0.12-0.90; p = 0.03). The mean cost for thromboprophylaxis with rivaroxaban was $53.37/patient, and no prophylaxis was $34.22/patient, with an incremental cost difference of $19.15. The effectiveness means obtained in the intervention group was 0.1457, while in the control group was 0.1421, determining an incremental QALY difference of 0.0036. The estimated incremental cost-effectiveness ratio (ICER) was $5385.52/QALY.

Interpretation

Extended treatment with Rivaroxaban as thromboprophylaxis after hospital discharge for high-risk patients with COVID-19 is a cost-effective treatment option.

Funding

Modest funding was provided by Science Valley Research Institute, São Paulo, Brazil.

Good practice statements for antithrombotic therapy in the management of COVID-19: Guidance from the SSC of the ISTH

Despite the emergence of high quality randomized trial data with the use of antithrombotic agents to reduce the risk of thromboembolism, end-organ failure, and possibly mortality in patients with coronavirus disease 2019 (COVID-19), questions still remain as to optimal patient selection for these strategies, the use of antithrombotics in outpatient settings and in-hospital settings (including critical care units), thromboprophylaxis in special patient populations, and the management of acute thrombosis in hospitalized COVID-19 patients. In October 2021, the International Society on Thrombosis and Haemostasis (ISTH) formed a multidisciplinary and international panel of content experts, two patient representatives, and a methodologist to develop recommendations on treatment with anticoagulants and antiplatelet agents for COVID-19 patients. The ISTH Guideline panel discussed additional topics to be well suited to a non-Grading of Recommendations Assessment, Development, and Evaluation (GRADE) for Good Practice Statements (GPS) to support good clinical care in the antithrombotic management of COVID-19 patients in various clinical settings. The GPS panel agreed on 17 GPS: 3 in the outpatient (pre-hospital) setting, 12 in the hospital setting both in non-critical care (ward) as well as intensive care unit settings, and 2 in the immediate post-hospital discharge setting based on limited evidence or expert opinion that supports net clinical benefit in enacting the statements provided. The antithrombotic therapies discussed in these GPS should be available in low- and middle-income countries.

Association of D-dimer with short-term risk of venous thromboembolism in acutely ill medical patients: A systematic review and meta-analysis

BACKGROUND

D-dimer, a marker of ongoing procoagulant activity, has been widely used for the diagnosis of venous thromboembolism (VTE). The prognostic significance of D-dimer in stratifying VTE risk for acutely ill medical patients has not been well-established.

METHODS

A literature search was performed to collect studies that compared the incidence of short-term VTE between acutely ill medical patients with elevated or nonelevated D-dimer levels. The cutoff of D-dimer was 0.5 μg/mL or otherwise defined by included studies. The study endpoint was any occurrence of VTE (inclusive of deep vein thrombosis [DVT], pulmonary embolism, or VTE-related death) within 90 days of hospital presentation. A meta-analytic approach was employed to estimate the odds ratio (OR) with 95% CI by fitting random-effects models using the generic inverse variance weighted approach.

RESULTS

A total of 10 studies representing 31,119 acutely ill medical patients were included. Compared to those with nonelevated D-dimer levels, patients with elevated D-dimer had approximately threefold greater odds for short-term VTE within 90 days (OR, 3.28; 95% CI, 2.44 to 4.40; p < 0.0001). The association of elevated D-dimer with VTE composite (OR, 3.33; 95% CI, 2.20 to 5.02) and with DVT (OR, 3.26; 95% CI, 2.32 to 4.58) was comparable. The association was significant among patients who presented various acute medical illness (OR, 2.68; 95% CI, 2.01 to 3.58) and those who presented with acute stroke (OR, 3.25; 95% CI, 2.31 to 4.58).

CONCLUSION

Elevation of D-dimer was predictive of the occurrence of VTE within 90 days among acutely ill medical patients. PROSPERO Registration ID: CRD42021264555.

Venous Thromboembolism in Sepsis: From Bench to Bedside

Septic patients were commonly affected by coagulation disorders; thus, they are at high risk of thrombotic complications. In the last decades, novel knowledge has emerged about the interconnected and reciprocal influence of immune and coagulation systems. This phenomenon is called immunothrombosis, and it indicates an effective response whereby immune cells and the coagulation cascade cooperate to limit pathogen invasion and endothelial damage. When this network becomes dysregulated due to a systemic inflammatory activation, as occurs during sepsis, it can result in pathological thrombosis. Endothelium, platelets and neutrophils are the main characters involved in this process, together with the TF and coagulation cascade, playing a critical role in both the host defense and in thrombogenesis. A deeper understanding of this relationship may allow us to answer the growing need for clinical instruments to establish the thrombotic risk and treatments that consider more the connection between coagulation and inflammation. Heparin remains the principal therapeutical response to this phenomenon, although not sufficiently effective. To date, no other significant alternatives have been found yet. In this review, we discuss the role of sepsis-related inflammation in the development and resolution of venous thromboembolism and its clinical implications, from bench to bedside.

3D-PAST: Risk Assessment Model for Predicting Venous Thromboembolism in COVID-19

Hypercoagulability is a recognized feature in SARS-CoV-2 infection. There exists a need for a dedicated risk assessment model (RAM) that can risk-stratify hospitalized COVID-19 patients for venous thromboembolism (VTE) and guide anticoagulation. We aimed to build a simple clinical model to predict VTE in COVID-19 patients. This large-cohort, retrospective study included adult patients admitted to four hospitals with PCR-confirmed SARS-CoV-2 infection. Model training was performed on 3531 patients hospitalized between March and December 2020 and validated on 2508 patients hospitalized between January and September 2021. Diagnosis of VTE was defined as acute deep vein thrombosis (DVT) or pulmonary embolism (PE). The novel RAM was based on commonly available parameters at hospital admission. LASSO regression and logistic regression were performed, risk scores were assigned to the significant variables, and cutoffs were derived. Seven variables with assigned scores were delineated as: DVT History = 2; High D-Dimer (>500−2000 ng/mL) = 2; Very High D-Dimer (>2000 ng/mL) = 5; PE History = 2; Low Albumin (<3.5 g/dL) = 1; Systolic Blood Pressure <120 mmHg = 1, Tachycardia (heart rate >100 bpm) = 1. The model had a sensitivity of 83% and specificity of 53%. This simple, robust clinical tool can help individualize thromboprophylaxis for COVID-19 patients based on their VTE risk category.

Extended post-discharge thromboprophylaxis in hospitalized COVID-19 patients

INTRODUCTION

Hospitalized COVID-19 patients, particularly those with high risk features, are at risk for venous and arterial thromboembolic events for approximately 30 days or more after hospital discharge. Extended post-hospital discharge thromboprophylaxis has potential to reduce this risk.

AREAS COVERED

Recent cohort, registry, and randomized trial data on the topic of extended post-discharge thromboprophylaxis in COVID-19 inpatients are reviewed, and key patient subgroups at high thrombotic risk are highlighted, with antithrombotic guidelines on the topic discussed.

EXPERT OPINION

COVID-19 inpatients with cardiovascular risk factors, advanced age, intensive care unit stay, or an IMPROVE VTE score of 4 or more or a score of 2 or 3 plus elevated D-dimers (> twice the upper limit of normal) or an IMPROVE-DD VTE score of ≥ 4 are at high thrombotic risk in the post-discharge period. These high risk patient subgroups benefit from extended post-discharge thromboprophylaxis, specifically with rivaroxaban 10mg daily for 35 days. Recent NIH and ISTH guidelines recommend or suggest this approach. Results from other clinical trials are pending.

Biomarker derived risk scores predict venous thromboembolism and major bleeding among patients with COVID-19

Background

Venous thromboembolism (VTE) risk is increased in patients with COVID-19 infection. Understanding which patients are likely to develop VTE may inform pharmacologic VTE prophylaxis decision making. The hospital-associated venous thromboembolism-Intermountain Risk Score (HA-VTE IMRS) and the hospital-associated major bleeding-Intermountain Risk Score (HA-MB IMRS) are risk scores predictive of VTE and bleeding that were derived from only patient age and data found in the complete blood count (CBC) and basic metabolic panel (BMP).

Objectives

We assessed the HA-VTE IMRS and HA-MB IMRS for predictiveness of 90-day VTE and major bleeding, respectively, among patients diagnosed with COVID-19, and further investigated if adding D-dimer improved these predictions. We also reported 30-day outcomes.

Patients/Methods

We identified 5047 sequential patients with a laboratory confirmed diagnosis of COVID-19 and a CBC and BMP between 2 days before and 7 days following the diagnosis of COVID-19 from March 12, 2020, to February 28, 2021. We calculated the HA-VTE IMRS and the HA-MB IMRS for all patients. We assessed the added predictiveness of D-dimer obtained within 48 hours of the COVID test.

Results

The HA-VTE IMRS yielded a c-statistic of 0.70 for predicting 90-day VTE and adding D-dimer improved the c-statistic to 0.764 with the corollary sensitivity/specificity/positive/negative predictive values of 49.4%/75.7%/6.7%/97.7% and 58.8%/76.2%/10.9%/97.4%, respectively. Among hospitalized and ambulatory patients separately, the HA-VTE IMRS performed similarly. The HA-MB IMRS predictiveness for 90-day major bleeding yielded a c-statistic of 0.64.

Conclusion

The HA-VTE IMRS and HA-MB IMRS predict 90- and 30-day VTE and major bleeding among COVID-19 patients. Adding D-dimer improved the predictiveness of the HA-VTE IMRS for VTE.

Use of Anticoagulants in COVID-19: A Review

BACKGROUND

Coronavirus disease 2019 (COVID-19) is associated with elevated rates of major and fatal thrombotic events, postulated to be the result of a hypercoagulable state mediated through inflammatory and immunomodulatory mechanisms. Early observational studies showed that disease severity and elevated serum D-dimer levels can predict thrombotic risk in patients hospitalized with COVID-19 and reported an alarming phenomenon of breakthrough thrombosis despite standard-of-care prophylaxis, suggesting the need for enhanced thromboprophylactic strategies.

AREAS OF UNCERTAINTY

Data on anticoagulant agent selection, dosing, and duration for COVID-19 inpatients are now poised to inform updated professional society guidance. However, there remains limited high-quality data regarding postdischarge and especially ambulatory patients with COVID-19.

DATA SOURCES

This review includes published, peer-reviewed, observational, and randomized controlled trial data and major professional society guidance informing thrombosis prevention and treatment in patients with COVID-19.

THERAPEUTIC ADVANCES

There remains great variability in the approach to anticoagulation in COVID-19. This article will review pathogenesis of COVID-related thrombosis and the evidence guiding thromboprophylaxis particularly in inpatients, with attention to the INSPIRATION, ACTION, RAPID, HEP-COVID, and multiplatform trials. Emerging thromboprophylaxis data from the postdischarge setting (particularly the recently published MICHELLE trial), and the outpatient setting, will be examined. Finally, thrombosis treatment considerations will briefly be reviewed.

CONCLUSIONS

Substantial high-quality data support practice changes to COVID-19 thromboprophylaxis. Risk stratification by setting, disease severity, and biomarkers such as D-dimer is critical in considering choice, dose, and duration of anticoagulants.

An update on the global use of risk assessment models and thromboprophylaxis in hospitalized patients with medical illnesses from the World Thrombosis Day steering committee: Systematic review and meta-analysis

INTRODUCTION

Venous thromboembolism (VTE) is a leading cause of cardiovascular morbidity and mortality. The majority of VTE events are hospital-associated. In 2008, the Epidemiologic International Day for the Evaluation of Patients at Risk for Venous Thromboembolism in the Acute Hospital Care Setting (ENDORSE) multinational cross-sectional study reported that only approximately 40% of medical patients at risk of VTE received adequate thromboprophylaxis.

METHODS

In our systematic review and meta-analysis, we aimed at providing updated figures concerning the use of thromboprophylaxis globally. We focused on: (a) the frequency of patients with an indication to thromboprophylaxis according with individual models; (b) the use of adequate thromboprophylaxis; and (c) reported contraindications to thromboprophylaxis. Observational nonrandomized studies or surveys focusing on medically ill patients were considered eligible.

RESULTS

After screening, we included 27 studies from 20 countries for a total of 137 288 patients. Overall, 50.5% (95% confidence interval [CI]: 41.9-59.1, I2 99%) of patients had an indication to thromboprophylaxis: of these, 54.5% (95% CI: 46.2-62.6, I2 99%) received adequate thromboprophylaxis. The use of adequate thromboprophylaxis was 66.8% in Europe (95% CI: 50.7-81.1, I2 98%), 44.9% in Africa (95% CI: 31.8-58.4, I2 96%), 37.6% in Asia (95% CI: 25.7-50.3, I2 97%), 58.3% in South America (95% CI: 31.1-83.1, I2 99%), and 68.6% in North America (95% CI: 64.9-72.6, I2 96%). No major differences in adequate thromboprophylaxis use were found across risk assessment models. Bleeding, thrombocytopenia, and renal/hepatic failure were the most frequently reported contraindications to thromboprophylaxis.

CONCLUSIONS

The use of anticoagulants for VTE prevention has been proven effective and safe, but thromboprophylaxis prescriptions are still unsatisfactory among hospitalized medically ill patients around the globe with marked geographical differences.

American Society of Hematology living guidelines on the use of anticoagulation for thromboprophylaxis in patients with COVID-19: July 2021 update on post-discharge thromboprophylaxis

Background

COVID-19–related acute illness is associated with an increased risk of venous thromboembolism (VTE).

Objective

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in decisions about the use of anticoagulation for thromboprophylaxis in patients with COVID-19 who do not have confirmed or suspected VTE.

Methods

ASH formed a multidisciplinary guideline panel, including 3 patient representatives, and applied strategies to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including performing systematic evidence reviews (up to March 2021). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the grading of recommendations assessment, development, and evaluation (GRADE) approach to assess evidence and make recommendations, which were subject to public comment.

Results

The panel agreed on 1 additional recommendation. The panel issued a conditional recommendation against the use of outpatient anticoagulant prophylaxis in patients with COVID-19 who are discharged from the hospital and who do not have suspected or confirmed VTE or another indication for anticoagulation.

Conclusions

This recommendation was based on very low certainty in the evidence, underscoring the need for high-quality randomized controlled trials assessing the role of postdischarge thromboprophylaxis. Other key research priorities include better evidence on assessing risk of thrombosis and bleeding outcomes in patients with COVID-19 after hospital discharge.