The Incidence of Pulmonary Embolism in Hospitalized Non-ICU Patients with COVID-19 during the First Wave: A Multicenter Retrospective Cohort Study in the Netherlands

INTRODUCTION

During the first COVID-19 outbreak in 2020 in the Netherlands, the incidence of pulmonary embolism (PE) appeared to be high in COVID-19 patients admitted to the intensive care unit (ICU). This study was performed to evaluate the incidence of PE during hospital stay in COVID-19 patients not admitted to the ICU.

METHODS

Data were retrospectively collected from 8 hospitals in the Netherlands. Patients admitted between February 27, 2020, and July 31, 2020, were included. Data extracted comprised clinical characteristics, medication use, first onset of COVID-19-related symptoms, admission date due to COVID-19, and date of PE diagnosis. Only polymerase chain reaction (PCR)-positive patients were included. All PEs were diagnosed with computed tomography pulmonary angiography (CTPA).

RESULTS

Data from 1,852 patients who were admitted to the hospital ward were collected. Forty patients (2.2%) were diagnosed with PE within 28 days following hospital admission. The median time to PE since admission was 4.5 days (IQR 0.0-9.0). In all 40 patients, PE was diagnosed within the first 2 weeks after hospital admission and for 22 (55%) patients within 2 weeks after onset of symptoms. Patient characteristics, pre-existing comorbidities, anticoagulant use, and laboratory parameters at admission were not related to the development of PE.

CONCLUSION

In this retrospective multicenter cohort study of 1,852 COVID-19 patients only admitted to the non-ICU wards, the incidence of CTPA-confirmed PE was 2.2% during the first 4 weeks after onset of symptoms and occurred exclusively within 2 weeks after hospital admission.

Tailored anticoagulant treatment after a first venous thromboembolism: protocol of the Leiden Thrombosis Recurrence Risk Prevention (L-TRRiP) study - cohort-based randomised controlled trial

INTRODUCTION

Patients with a first venous thromboembolism (VTE) are at risk of recurrence. Recurrent VTE (rVTE) can be prevented by extended anticoagulant therapy, but this comes at the cost of an increased risk of bleeding. It is still uncertain whether patients with an intermediate recurrence risk or with a high recurrence and high bleeding risk will benefit from extended anticoagulant treatment, and whether a strategy where anticoagulant duration is tailored on the predicted risks of rVTE and bleeding can improve outcomes. The aim of the Leiden Thrombosis Recurrence Risk Prevention (L-TRRiP) study is to evaluate the outcomes of tailored duration of long-term anticoagulant treatment based on individualised assessment of rVTE and major bleeding risks.

METHODS AND ANALYSIS

The L-TRRiP study is a multicentre, open-label, cohort-based, randomised controlled trial, including patients with a first VTE. We classify the risk of rVTE and major bleeding using the L-TRRiP and VTE-BLEED scores, respectively. After 3 months of anticoagulant therapy, patients with a low rVTE risk will discontinue anticoagulant treatment, patients with a high rVTE and low bleeding risk will continue anticoagulant treatment, whereas all other patients will be randomised to continue or discontinue anticoagulant treatment. All patients will be followed up for at least 2 years. Inclusion will continue until the randomised group consists of 608 patients; we estimate to include 1600 patients in total. The primary outcome is the combined incidence of rVTE and major bleeding in the randomised group after 2 years of follow-up. Secondary outcomes include the incidence of rVTE and major bleeding, functional outcomes, quality of life and cost-effectiveness in all patients.

ETHICS AND DISSEMINATION

The protocol was approved by the Medical Research Ethics Committee Leiden-Den Haag-Delft. Results are expected in 2028 and will be disseminated through peer-reviewed journals and during (inter)national conferences.

TRIAL REGISTRATION NUMBER

NCT06087952.

Optimizing antithrombotic therapy in patients with coexisting cardiovascular and gastrointestinal disease

Balancing the safety and efficacy of antithrombotic agents in patients with gastrointestinal disorders is challenging because of the potential for interference with the absorption of antithrombotic drugs and for an increased risk of bleeding. In this Review, we address considerations for enteral antithrombotic therapy in patients with cardiovascular disease and gastrointestinal comorbidities. For those with gastrointestinal bleeding (GIB), we summarize a general scheme for risk stratification and clinical evidence on risk reduction approaches, such as limiting the use of concomitant medications that increase the risk of GIB and the potential utility of gastrointestinal protection strategies (such as proton pump inhibitors or histamine type 2 receptor antagonists). Furthermore, we summarize the best available evidence and potential gaps in our knowledge on tailoring antithrombotic therapy in patients with active or recent GIB and in those at high risk of GIB but without active or recent GIB. Finally, we review the recommendations provided by major medical societies, highlighting the crucial role of teamwork and multidisciplinary discussions to customize the antithrombotic regimen in patients with coexisting cardiovascular and gastrointestinal diseases.

2023 ISTH update of the 2022 ISTH guidelines for antithrombotic treatment in COVID-19

Based on emerging evidence from the COVID-19 pandemic, the International Society on Thrombosis and Haemostasis (ISTH) guidelines for antithrombotic treatment in COVID-19 were published in 2022. Since then, at least 16 new randomized controlled trials have contributed additional evidence, which necessitated a modification of most of the previous recommendations. We used again the American College of Cardiology Foundation/American Heart Association methodology for assessment of level of evidence (LOE) and class of recommendation (COR). Five recommendations had the LOE upgraded to A and 2 new recommendations on antithrombotic treatment for patients with COVID-19 were added. Furthermore, a section was added to answer questions about COVID-19 vaccination and vaccine-induced immune thrombotic thrombocytopenia (VITT), for which studies have provided some evidence. We only included recommendations with LOE A or B. Panelists agreed on 19 recommendations, 4 for nonhospitalized, 5 for noncritically ill hospitalized, 3 for critically ill hospitalized, and 2 for postdischarge patients, as well as 5 for vaccination and VITT. A strong recommendation (COR 1) was given for (a) use of prophylactic dose of low-molecular-weight heparin or unfractionated heparin in noncritically ill patients hospitalized for COVID-19, (b) for select patients in this group, use of therapeutic-dose low-molecular-weight heparin/unfractionated heparin in preference to prophylactic dose, and (c) for use of antiplatelet factor 4 enzyme immunoassays for diagnosing VITT. A strong recommendation was given against (COR 3) the addition of an antiplatelet agent in hospitalized, noncritically ill patients. These international guidelines provide recommendations for countries with diverse healthcare resources and COVID-19 vaccine availability.

VTE Risk Assessment and Prevention in Pregnancy

Venous thromboembolism (VTE) remains the leading cause of maternal mortality in pregnancy and the postpartum period. In addition to the higher pregnancy-associated baseline VTE risk, there are several well-established risk factors that can further increase the risk of VTE. At present, a thorough interrogation of these risk factors remains our only tool for estimating which pregnant people may be at an increased risk of VTE, and thus potentially benefit from thromboprophylaxis. However, an important knowledge gap still exists surrounding the duration of increased risk and the interaction of risk factors with each other. Furthermore, up to now, once significant risk has been established, prevention strategies have been largely based on expert opinion rather than high-quality data. Recent trials have successfully bridged a proportion of this knowledge gap; however, the challenge of conducting high-quality clinical trials with pregnant people remains. In this article, we provide an update on the recent evidence surrounding VTE risk factors in pregnancy while concurrently outlining knowledge gaps and current approaches to VTE prevention.

When Direct Oral Anticoagulants Should Not Be Standard Treatment: JACC State-of-the-Art Review

For most patients, direct oral anticoagulants (DOACs) are preferred over vitamin K antagonists for stroke prevention in atrial fibrillation and for venous thromboembolism treatment. However, randomized controlled trials suggest that DOACs may not be as efficacious or as safe as the current standard of care in conditions such as mechanical heart valves, thrombotic antiphospholipid syndrome, and atrial fibrillation associated with rheumatic heart disease. DOACs do not provide a net benefit in conditions such as embolic stroke of undetermined source. Their efficacy is uncertain for conditions such as left ventricular thrombus, catheter-associated deep vein thrombosis, cerebral venous sinus thrombosis, and for patients with atrial fibrillation or venous thrombosis who have end-stage renal disease. This paper provides an evidence-based review of randomized controlled trials on DOACs, detailing when they have demonstrated efficacy and safety, when DOACs should not be the standard of care, where their safety and efficacy are uncertain, and areas requiring further research.

Developmental or Procedural Vena Cava Interruption and Venous Thromboembolism: A Review

The inferior vena cava (IVC) and superior vena cava are the main conduits of the systemic venous circulation into the right atrium. Developmental or procedural interruptions of vena cava might predispose to stasis and deep vein thrombosis (DVT) distal to the anomaly and may impact the subsequent rate of pulmonary embolism (PE). This study aimed to review the various etiologies of developmental or procedural vena cava interruption and their impact on venous thromboembolism. A systematic search was performed in PubMed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines per each clinical question. For management questions with no high-quality evidence and no mutual agreements between authors, Delphi methods were used. IVC agenesis is the most common form of congenital vena cava interruption, is associated with an increased risk of DVT, and should be suspected in young patients with unexpected extensive bilateral DVT. Surgical techniques for vena cava interruption (ligation, clipping, and plication) to prevent PE have been largely abandoned due to short-term procedural risks and long-term complications, although survivors of prior procedures are occasionally encountered. Vena cava filters are now the most commonly used method of procedural interruption, frequently placed in the infrarenal IVC. The most agreed-upon indication for vena cava filters is for patients with acute venous thromboembolism and coexisting contraindications to anticoagulation. Familiarity with different forms of vena cava interruption and their local and systemic adverse effects is important to minimize complications and thrombotic events.

Sex differences in cerebral venous sinus thrombosis after adenoviral vaccination against COVID-19

INTRODUCTION

Cerebral venous sinus thrombosis associated with vaccine-induced immune thrombotic thrombocytopenia (CVST-VITT) is a severe disease with high mortality. There are few data on sex differences in CVST-VITT. The aim of our study was to investigate the differences in presentation, treatment, clinical course, complications, and outcome of CVST-VITT between women and men.

PATIENTS AND METHODS

We used data from an ongoing international registry on CVST-VITT. VITT was diagnosed according to the Pavord criteria. We compared the characteristics of CVST-VITT in women and men.

RESULTS

Of 133 patients with possible, probable, or definite CVST-VITT, 102 (77%) were women. Women were slightly younger [median age 42 (IQR 28-54) vs 45 (28-56)], presented more often with coma (26% vs 10%) and had a lower platelet count at presentation [median (IQR) 50x109/L (28-79) vs 68 (30-125)] than men. The nadir platelet count was lower in women [median (IQR) 34 (19-62) vs 53 (20-92)]. More women received endovascular treatment than men (15% vs 6%). Rates of treatment with intravenous immunoglobulins were similar (63% vs 66%), as were new venous thromboembolic events (14% vs 14%) and major bleeding complications (30% vs 20%). Rates of good functional outcome (modified Rankin Scale 0-2, 42% vs 45%) and in-hospital death (39% vs 41%) did not differ.

DISCUSSION AND CONCLUSIONS

Three quarters of CVST-VITT patients in this study were women. Women were more severely affected at presentation, but clinical course and outcome did not differ between women and men. VITT-specific treatments were overall similar, but more women received endovascular treatment.

American Society of Hematology 2023 guidelines for management of venous thromboembolism: thrombophilia testing

Hereditary and acquired thrombophilia are risk factors for venous thromboembolism (VTE). Whether testing helps guide management decisions is controversial. These evidence-based guidelines from the American Society of Hematology (ASH) intend to support decision making about thrombophilia testing. ASH formed a multidisciplinary guideline panel covering clinical and methodological expertise and minimizing bias from conflicts of interest. The McMaster University GRADE Centre provided logistical support, performed systematic reviews, and created evidence profiles and evidence-to-decision tables. The Grading of Recommendations Assessment, Development, and Evaluation approach (GRADE) was used. Recommendations were subject to public comment. The panel agreed on 23 recommendations regarding thrombophilia testing and associated management. Nearly all recommendations are based on very low certainty in the evidence due to modeling assumptions. The panel issued a strong recommendation against testing the general population before starting combined oral contraceptives (COCs) and conditional recommendations for thrombophilia testing in the following scenarios: (a) patients with VTE associated with nonsurgical major transient or hormonal risk factors; (b) patients with cerebral or splanchnic venous thrombosis, in settings where anticoagulation would otherwise be discontinued; (c) individuals with a family history of antithrombin, protein C, or protein S deficiency when considering thromboprophylaxis for minor provoking risk factors and for guidance to avoid COCs/hormone replacement therapy; (d) pregnant women with a family history of high-risk thrombophilia types; and (e) patients with cancer at low or intermediate risk of thrombosis and with a family history of VTE. For all other questions, the panel provided conditional recommendations against testing for thrombophilia.

Performance of the 4-Level Pulmonary Embolism Clinical Probability Score (4PEPS) in the diagnostic management of pulmonary embolism: An external validation study

BACKGROUND

The recently published 4-level Pulmonary Embolism Clinical Probability Score (4PEPS) integrates different aspects from currently available diagnostic strategies to further reduce imaging testing in patients with clinically suspected pulmonary embolism (PE).

AIM

To externally validate the performance of 4PEPS in an independent cohort.

METHODS

In this post-hoc analysis of the prospective diagnostic management YEARS study, the primary outcome measures were discrimination, calibration, efficiency (proportion of imaging tests potentially avoided), and failure rate (venous thromboembolism (VTE) diagnosis at baseline or follow-up in patients with a negative 4PEPS algorithm). Multiple imputation was used for missing 4PEPS items. Based on 4PEPS, PE was considered ruled out in patients with a very low clinical pre-test probability (CPTP) without D-dimer testing, in patients with a low CPTP and D-dimer <1000 μg/L, and in patients with a moderate CPP and D-dimer below the age-adjusted threshold.

RESULTS

Of the 3465 patients, 474 (14 %) were diagnosed with VTE at baseline or during 3-month follow-up. Discriminatory performance of the 4PEPS items was good (area under ROC-curve, 0.82; 95%CI, 0.80-0.84) as was calibration. Based on 4PEPS, PE could be considered ruled out without imaging in 58 % (95%CI 57-60) of patients (efficiency), for an overall failure rate of 1.3 % (95%CI 0.86-1.9).

CONCLUSION

In this retrospective external validation, 4PEPS appeared to safely rule out PE with a high efficiency. Nevertheless, although not exceeding the failure rate margin by ISTH standards, the observed failure rate in our analysis appeared to be higher than in the original 4PEPS derivation and validation study. This highlights the importance of a prospective outcome study.

Venous thromboembolism among physically active young adult females

Background

Young adult females are at risk of venous thromboembolism (VTE) due to various acquired and transient factors. In recent years, a growing number of females have engaged in strenuous physical activity, but its role as a risk factor for VTE is uncertain.

Objectives

To determine the incidence of VTE in young adult females engaged in strenuous physical activity.

Methods

A large national cohort of female individuals enlisted in the Israeli Defense Forces between 2012 and 2019 was analyzed. The study group consisted of participants undergoing strenuous physical training during their military service, while the control group maintained regular activity levels. We compared the incidence of VTE between the groups and adjusted for potential risk factors using a multivariate Cox analysis.

Results

The cohort included 160,718 female individuals aged 18 to 21years, of whom 11,745 engaged in strenuous physical activity and 148,973 served as controls. During a mean follow-up of 1.7 years, VTE occurred in 5 individuals (0.04%) in the strenuous activity group and 47 individuals (0.03%) in the control group. The incidence per 10,000 person-years was 2.41 (95% CI, 0.78-5.62) for the strenuous activity group and 1.82 (95% CI, 1.34-2.42) for the controls. Strenuous activity did not increase the risk for VTE in univariate or multivariate regression, with a hazard ratio (HR) of 1.27 (95% CI, 0.49-4.22). Use of oral contraceptives was the only significant risk factor, demonstrating dose effect; HR 1.95 (95% CI, 1.06-3.57) for low dose and HR 3.62 (95% CI, 1.40-9.37) for medium estrogen dose contraceptives.

Conclusion

Strenuous physical activity did not increase the risk for VTE among a large cohort of young adult female individuals.

Direct oral anticoagulants for the treatment of cerebral venous thrombosis - a protocol of an international phase IV study

Introduction

Current guidelines recommend that patients with cerebral venous thrombosis (CVT) should be treated with vitamin K antagonists (VKAs) for 3-12 months. Direct oral anticoagulants (DOACs), however, are increasingly used in clinical practice. An exploratory randomized controlled trial including 120 patients with CVT suggested that the efficacy and safety profile of dabigatran (a DOAC) is similar to VKAs for the treatment of CVT, but large-scale prospective studies from a real-world setting are lacking.

Methods

DOAC-CVT is an international, prospective, observational cohort study comparing DOACs to VKAs for the prevention of recurrent venous thrombotic events after acute CVT. Patients are eligible if they are 18 years or older, have a radiologically confirmed CVT, and have started oral anticoagulant treatment (DOAC or VKA) within 30 days of CVT diagnosis. Patients with an absolute contra-indication for DOACs, such as pregnancy or severe renal insufficiency, are excluded from the study. We aim to recruit at least 500 patients within a three-year recruitment period. The primary endpoint is a composite of recurrent venous thrombosis and major bleeding at 6 months of follow-up. We will calculate an adjusted odds ratio for the primary endpoint using propensity score inverse probability treatment weighting.

Discussion

DOAC-CVT will provide real-world data on the comparative efficacy and safety of DOACs versus VKAs for the treatment of CVT.

Clinical trial registration

ClinicalTrials.gov, NCT04660747.

Prevalence and Predictors of Nonadherence to Direct Oral Anticoagulant Treatment in Patients with Atrial Fibrillation

Background  For most patients with newly diagnosed atrial fibrillation (AF), direct oral anticoagulants (DOACs) are preferred over vitamin K antagonists. However, there is concern that the lack of monitoring may impair therapy adherence and therefore the anticoagulant effect. Objective  To assess 1-year DOAC nonadherence in patients with AF and a treatment indication of at least 1 year in the Dutch health care setting, and to identify predictors of nonadherence. Methods  We performed a near-nationwide historical cohort study in patients with a novel DOAC indication for AF. Data were obtained from a pharmacy database, covering 65% of all outpatient prescriptions dispensed in the Netherlands. The 1-year nonadherence was assessed by the proportion of days covered; the threshold was set at <80%. Robust Poisson regression analyses were performed to identify predictors of nonadherence. Results  A total of 46,211 patients were included and the 1-year nonadherence was 6.5%. We identified male sex (risk ratio [RR] 1.23, 95% confidence interval [CI]: 1.15-1.33), younger age (age ≥60 to <70 years: RR: 1.15, 95% CI: 1.00-1.33, age <60 years: RR: 2.22, 95% CI: 1.92-2.57; reference age ≥85 years), a reduced DOAC dose (RR: 1.10, 95% CI: 1.00-1.22), a twice-daily dosing regimen (RR: 1.21, 95% CI: 1.12-1.30), and treatment with apixaban (RR: 1.16, 95% CI: 1.06-1.26, reference rivaroxaban) or dabigatran (RR: 1.25, 95% CI: 1.14-1.37) as independent predictors of 1-year nonadherence. Conclusion  One-year nonadherence to DOACs was low yet relevant in patients with AF newly prescribed a DOAC. Understanding the predictors for nonadherence may help identify patients at risk.

Heparin for women with recurrent miscarriage and inherited thrombophilia (ALIFE2): an international open-label, randomised controlled trial

BACKGROUND

Anticoagulant therapy might reduce the number of miscarriages and adverse pregnancy outcomes in women with recurrent pregnancy loss and inherited thrombophilia. We aimed to assess use of low-molecular-weight heparin (LMWH) versus standard care in this population.

METHODS

The ALIFE2 trial was an international open-label, randomised controlled trial undertaken in hospitals in the UK (n=26), the Netherlands (n=10), the USA (n=2), Belgium (n=1), and Slovenia (n=1). Women aged 18-42 years who had two or more pregnancy losses and confirmed inherited thrombophilia, and who were trying to conceive or were already pregnant (≤7 weeks' gestation), were eligible for inclusion. Women were randomly assigned (1:1) to use low-dose LMWH or not (alongside standard care in both groups) once they had a positive urine pregnancy test. LMWH was started at or before 7 weeks' gestation and continued until the end of pregnancy. The primary outcome measure was livebirth rate, assessed in all women with available data. Safety outcomes included bleeding episodes, thrombocytopenia, and skin reactions, and were assessed in all randomly assigned women who reported a safety event. The trial was registered within the Dutch Trial Register (NTR3361) and EudraCT (UK: 2015-002357-35).

FINDINGS

Between Aug 1, 2012, and Jan 30, 2021, 10 625 women were assessed for eligibility, 428 were registered, and 326 conceived and were randomly assigned (164 to LMWH and 162 to standard care). 116 (72%) of 162 women with primary outcome data in the LMWH group and 112 (71%) of 158 in the standard care group had livebirths (adjusted odds ratio 1·08, 95% CI 0·65 to 1·78; absolute risk difference, 0·7%, 95% CI -9·2% to 10·6%). 39 (24%) of 164 women in the LMWH group and 37 (23%) of 162 women in the standard care group reported adverse events.

INTERPRETATION

LMWH did not result in higher livebirth rates in women who had two or more pregnancy losses and confirmed inherited thrombophilia. We do not advise use of LMWH in women with recurrent pregnancy loss and inherited thrombophilia, and we advise against screening for inherited thrombophilia in women with recurrent pregnancy loss.

FUNDING

National Institute for Health and Care Research and the Netherlands Organization for Health Research and Development.

Incidence and prognosis of superficial vein thrombosis during pregnancy and the post-partum period: a Danish nationwide cohort study

BACKGROUND

The incidence of superficial vein thrombosis (SVT) of the legs and the subsequent risk of venous thromboembolism during pregnancy and the post-partum period is unknown. To better understand the clinical course of SVT during these times, we aimed to estimate the incidence rate of SVT during pregnancy and in the post-partum period, as well as the risk of subsequent venous thromboembolism.

METHODS

In this nationwide cohort study, we collected data on all pregnant women who delivered between Jan 1, 1997, and Dec 31, 2017, in Denmark were extracted from the Danish Medical Birth Register, the Danish National Patient Registry, and the Danish National Prescription Registry. Data on ethnicity were not available. Incidence rates per 1000 person-years were calculated for each trimester and the antepartum and post-partum period. Among women with a pregnancy-related SVT, risk of subsequent venous thromboembolism within the same pregnancy or post-partum period were calculated and compared with a matched cohort of pregnant women without SVT using Cox proportional hazards analysis.

FINDINGS

During 1 276 046 deliveries, 710 diagnoses of lower extremity SVT occurred from conception up to 12 weeks postpartum (0·6 per 1000 person-years [95% CI 0·5-0·6]). The incidence rates of SVT per 1000 person-years were 0·1 (95% CI 0·1-0·2) during the during the first trimester, 0·2 (0·2-0·3) during the second trimester, and 0·5 (0·5-0·6) during the third trimester. The incidence rate was 1·6 per 1000 person-years (95% CI 1·4-1·7) during the post-partum period. Of the 211 women with antepartum SVT included in the analysis, 22 (10·4%) were diagnosed with venous thromboembolism, compared with 25 (0·1%) in women without SVT (hazard ratio 83·3 [95% CI 46·3-149·7]).

INTERPRETATION

The incidence rate of SVT during pregnancy and the post-partum period was low. However, if SVT during pregnancy was diagnosed, the risk of developing venous thromboembolism during the same pregnancy was high. These results might help physicians and patients to make decisions about anticoagulant management of pregnancy-related SVT.

FUNDING

None.

[Venous thromboembolism and antiphospholipid syndrome - considerations on diagnosis and treatment]

Antiphospholipid syndrome (APS) is an auto-immune syndrome defined by thrombosis and/or pregnancy morbidity in the persistent presence of antiphospholipid antibodies. Antiphospholipid antibodies are a group of antibodies predominantly directed at phospholipid-bound plasma proteins. The more antibodies a patient has the higher the risk of thrombosis. The origin of the antibodies and the precise prothrombotic mechanism are incompletely understood. A diagnosis of APS can in certain clinical scenarios implicate a longer treatment with anticoagulants after a venous thromboembolism. High level evidence is absent. In addition, APS patients with a high risk antibody profile had a higher risk of arterial thrombosis in randomized trials when treated with direct oral anticoagulants compared to vitamin K antagonists. The number needed to screen in light of these possible consequences of an APS diagnosis for treatment, appears to high to justify routine screening. In this review we suggest indications for APS testing in the context of venous thromboembolism.

Noninvasive diagnostic work-up for suspected acute pulmonary embolism during pregnancy: a systematic review and meta-analysis of individual patient data

BACKGROUND

Few studies evaluated the performance of noninvasive diagnostic strategies for suspected acute pulmonary embolism (PE) in pregnant women.

OBJECTIVES

The aim of this study was to establish the safety and efficiency of the Wells rule with fixed and adapted D-dimer threshold, and the YEARS algorithm, combined with compression ultrasonography (CUS), in pregnant women with suspected PE in an individual patient data meta-analysis.

METHODS

We performed a systematic review to identify prospective diagnostic management studies in pregnant women with suspected PE. Primary outcomes were safety, defined as the failure rate, ie, the 3-month venous thromboembolism (VTE) incidence after excluding PE without chest imaging, and efficiency, defined as the proportion of patients in whom chest imaging could be avoided.

RESULTS

We identified 2 relevant studies, of which individual patient-level data were analyzed in a fixed-effect meta-analysis, totaling 893 pregnant women. The Wells rule with fixed and adapted D-dimer threshold as well as the YEARS algorithm could safely rule out acute PE (failure rate, 0·37%-1·4%), but efficiency improved considerably when applying pretest probability-adapted D-dimer thresholds. The efficiency of bilateral CUS was limited (2·3% overall; number needed to test 43), especially in patients without symptoms of deep-vein thrombosis (efficiency 0·79%; number needed to test 127).

CONCLUSION

This study supports the latest guideline recommendations (European Society of Cardiology 2019) to apply pretest probability assessment and D-dimer tests to rule out PE in pregnant women. From an efficiency perspective, the use of a strategy with pretest probability-adapted D-dimer threshold is preferred. The yield of CUS was very limited in patients without concomitant symptoms of deep-vein thrombosis.

Redefining clinical venous thromboembolism phenotypes: a novel approach using latent class analysis

BACKGROUND

Patients with venous thromboembolism (VTE) are commonly classified by the presence or absence of provoking factors at the time of VTE to guide treatment decisions. This approach may not capture the heterogeneity of the disease and its prognosis.

OBJECTIVES

To evaluate clinically important novel phenotypic clusters among patients with VTE without cancer and to explore their association with anticoagulant treatment and clinical outcomes.

METHODS

Latent class analysis was performed with 18 baseline clinical variables in 3062 adult patients with VTE without active cancer participating in PREFER in VTE, a noninterventional disease registry. The derived latent classes were externally validated in a post hoc analysis of Hokusai-VTE (n = 6593), a randomized trial comparing edoxaban with warfarin. The associations between cluster membership and anticoagulant treatment, recurrent VTE, bleeding, and mortality after initial treatment were studied.

RESULTS

The following 5 clusters were identified: young men cluster (n = 1126, 37%), young women cluster (n = 215, 7%), older people cluster (n = 1106, 36%), comorbidity cluster (n = 447, 15%), and history of venous thromboembolism cluster (n = 168, 5%). Patient characteristics varied by age, sex, medical history, and treatment patterns. Consistent clusters were evident on external validation. In Cox proportional hazard models, recurrence risk was lower in the young women cluster (hazard ratio [HR], 0.27; 95% CI, 0.12-0.61) compared with the comorbidity cluster, after adjusting for extended anticoagulation. The risk of bleeding was lower in young men, young women, and older people clusters (HR, 0.50; 95% CI, 0.38-0.66; HR, 0.23; 95% CI, 0.11-0.46; and HR, 0.55; 95% CI 0.41-0.73, respectively).

CONCLUSION

The heterogeneity of VTE cases extends beyond the distinction between provoked and unprovoked VTE.

Final Study Report of Andexanet Alfa for Major Bleeding With Factor Xa Inhibitors

BACKGROUND

Andexanet alfa is a modified recombinant inactive factor Xa (FXa) designed to reverse FXa inhibitors. ANNEXA-4 (Andexanet Alfa, a Novel Antidote to the Anticoagulation Effects of Factor Xa Inhibitors) was a multicenter, prospective, phase-3b/4, single-group cohort study that evaluated andexanet alfa in patients with acute major bleeding. The results of the final analyses are presented.

METHODS

Patients with acute major bleeding within 18 hours of FXa inhibitor administration were enrolled. Co-primary end points were anti-FXa activity change from baseline during andexanet alfa treatment and excellent or good hemostatic efficacy, defined by a scale used in previous reversal studies, at 12 hours. The efficacy population included patients with baseline anti-FXa activity levels above predefined thresholds (≥75 ng/mL for apixaban and rivaroxaban, ≥40 ng/mL for edoxaban, and ≥0.25 IU/mL for enoxaparin; reported in the same units used for calibrators) who were adjudicated as meeting major bleeding criteria (modified International Society of Thrombosis and Haemostasis definition). The safety population included all patients. Major bleeding criteria, hemostatic efficacy, thrombotic events (stratified by occurring before or after restart of either prophylactic [ie, a lower dose, for prevention rather than treatment] or full-dose oral anticoagulation), and deaths were assessed by an independent adjudication committee. Median endogenous thrombin potential at baseline and across the follow-up period was a secondary outcome.

RESULTS

There were 479 patients enrolled (mean age, 78 years; 54% male, 86% White; 81% anticoagulated for atrial fibrillation at a median time of 11.4 hours since last dose, with 245 (51%) on apixaban, 176 (37%) on rivaroxaban, 36 (8%) on edoxaban, and 22 (5%) on enoxaparin. Bleeding was predominantly intracranial (n=331 [69%]) or gastrointestinal (n=109 [23%]). In evaluable apixaban patients (n=172), median anti-FXa activity decreased from 146.9 ng/mL to 10.0 ng/mL (reduction, 93% [95% CI, 94-93]); in rivaroxaban patients (n=132), it decreased from 214.6 ng/mL to 10.8 ng/mL (94% [95% CI, 95-93]); in edoxaban patients (n=28), it decreased from 121.1 ng/mL to 24.4 ng/mL (71% [95% CI, 82-65); and in enoxaparin patients (n=17), it decreased from 0.48 IU/mL to 0.11 IU/mL (75% [95% CI, 79-67]). Excellent or good hemostasis occurred in 274 of 342 evaluable patients (80% [95% CI, 75-84]). In the safety population, thrombotic events occurred in 50 patients (10%); in 16 patients, this occurred during treatment with prophylactic anticoagulation that began after the bleeding event. No thrombotic episodes occurred after oral anticoagulation restart. Specific to certain populations, reduction of anti-FXa activity from baseline to nadir significantly predicted hemostatic efficacy in patients with intracranial hemorrhage (area under the receiver operating characteristic curve, 0.62 [95% CI, 0.54-0.70]) and correlated with lower mortality in patients <75 years of age (adjusted P=0.022; unadjusted P=0.003). Median endogenous thrombin potential was within the normal range by the end of andexanet alfa bolus through 24 hours for all FXa inhibitors.

CONCLUSIONS

In patients with major bleeding associated with the use of FXa inhibitors, treatment with andexanet alfa reduced anti-FXa activity and was associated with good or excellent hemostatic efficacy in 80% of patients.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02329327.

Decompressive surgery in cerebral venous sinus thrombosis due to vaccine-induced immune thrombotic thrombocytopenia

BACKGROUND AND PURPOSE

Cerebral venous sinus thrombosis due to vaccine-induced immune thrombotic thrombocytopenia (CVST-VITT) is an adverse drug reaction occurring after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. CVST-VITT patients often present with large intracerebral haemorrhages and a high proportion undergoes decompressive surgery. Clinical characteristics, therapeutic management and outcomes of CVST-VITT patients who underwent decompressive surgery are described and predictors of in-hospital mortality in these patients are explored.

METHODS

Data from an ongoing international registry of patients who developed CVST within 28 days of SARS-CoV-2 vaccination, reported between 29 March 2021 and 10 May 2022, were used. Definite, probable and possible VITT cases, as defined by Pavord et al. (N Engl J Med 2021; 385: 1680-1689), were included.

RESULTS

Decompressive surgery was performed in 34/128 (27%) patients with CVST-VITT. In-hospital mortality was 22/34 (65%) in the surgical and 27/94 (29%) in the non-surgical group (p < 0.001). In all surgical cases, the cause of death was brain herniation. The highest mortality rates were found amongst patients with preoperative coma (17/18, 94% vs. 4/14, 29% in the non-comatose; p < 0.001) and bilaterally absent pupillary reflexes (7/7, 100% vs. 6/9, 67% with unilaterally reactive pupil, and 4/11, 36% with bilaterally reactive pupils; p = 0.023). Postoperative imaging revealed worsening of index haemorrhagic lesion in 19 (70%) patients and new haemorrhagic lesions in 16 (59%) patients. At a median follow-up of 6 months, 8/10 of surgical CVST-VITT who survived admission were functionally independent.

CONCLUSIONS

Almost two-thirds of surgical CVST-VITT patients died during hospital admission. Preoperative coma and bilateral absence of pupillary responses were associated with higher mortality rates. Survivors often achieved functional independence.

Risk of venous thromboembolism and bleeding after major surgery for ovarian cancer: standard in-hospital versus extended duration of thromboprophylaxis

BACKGROUND

Venous thromboembolism (VTE) is a frequent complication in patients with ovarian cancer after major surgery. Based on limited data, international guidelines recommend extended thromboprophylaxis for up to 28 days.

OBJECTIVES

To assess the incidence of VTE and bleeding within 30 days following major surgery in patients with ovarian cancer and to evaluate the association between VTE and thromboprophylaxis duration.

METHODS

This was a single-center, retrospective, "before-after" cohort study in patients with ovarian cancer undergoing major surgery. Before July 2019, the local protocol mandated a standard course of thromboprophylaxis during hospital stay only. From July 2019 onward, patients received extended thromboprophylaxis for 28 days. The cumulative incidences of VTE and major bleeding within 30 days after surgery were estimated using the Kaplan-Meier method, with 95% confidence intervals (CIs). Cox regression analysis was performed to evaluate the association between thromboprophylaxis duration and VTE incidence.

RESULTS

Between January 2018 and December 2020, 250 women were included, of which 118 (47.2%) received extended and 132 (52.8%) standard thromboprophylaxis. During follow-up, 12 patients developed VTE (cumulative incidence, 4.8%; 95% CI, 2.1-7.4) and 2 major bleeding (cumulative incidence 0.8%; 95% CI, 0.0-1.9). Compared with standard thromboprophylaxis, VTE incidence was numerically lower with extended duration of thromboprophylaxis (5/118 [4.2%] vs 7/132 [5.3%]) but not significantly different (hazard ratio, 0.80; 95% CI, 0.25-2.52). The risk of major bleeding was similar in both groups (1/118 [0.8%] vs 1/132 [0.8%]; hazard ratio, 1.12; 95% CI, 0.07-17.89).

CONCLUSIONS

The cumulative VTE incidence in patients with ovarian cancer following major surgery was considerable. Extended thromboprophylaxis was safe and associated with a numerically lower risk of VTE but not significantly different.

Recurrent venous thromboembolism and bleeding with extended anticoagulation: the VTE-PREDICT risk score

AIMS

Deciding to stop or continue anticoagulation for venous thromboembolism (VTE) after initial treatment is challenging, as individual risks of recurrence and bleeding are heterogeneous. The present study aimed to develop and externally validate models for predicting 5-year risks of recurrence and bleeding in patients with VTE without cancer who completed at least 3 months of initial treatment, which can be used to estimate individual absolute benefits and harms of extended anticoagulation.

METHODS AND RESULTS

Competing risk-adjusted models were derived to predict recurrent VTE and clinically relevant bleeding (non-major and major) using 14 readily available patient characteristics. The models were derived from combined individual patient data from the Bleeding Risk Study, Hokusai-VTE, PREFER-VTE, RE-MEDY, and RE-SONATE (n = 15,141, 220 recurrences, 189 bleeding events). External validity was assessed in the Danish VTE cohort, EINSTEIN-CHOICE, GARFIELD-VTE, MEGA, and Tromsø studies (n = 59 257, 2283 recurrences, 3335 bleeding events). Absolute treatment effects were estimated by combining the models with hazard ratios from trials and meta-analyses. External validation in different settings showed agreement between predicted and observed risks up to 5 years, with C-statistics ranging from 0.48-0.71 (recurrence) and 0.61-0.68 (bleeding). In the Danish VTE cohort, 5-year risks ranged from 4% to 19% for recurrent VTE and 1% -19% for bleeding.

CONCLUSION

The VTE-PREDICT risk score can be applied to estimate the effect of extended anticoagulant treatment for individual patients with VTE and to support shared decision-making.

Direct Oral Anticoagulants vs Vitamin K Antagonists in Patients With Antiphospholipid Syndromes: Meta-Analysis of Randomized Trials

BACKGROUND

The efficacy and safety of direct oral anticoagulants (DOACs) for patients with thrombotic antiphospholipid syndrome remain controversial.

OBJECTIVES

The authors performed a systematic review and meta-analysis of randomized controlled trials that compared DOACs with vitamin K antagonists (VKAs).

METHODS

We searched PubMed, EMBASE, and Cochrane Central Register of Controlled Trials through April 9, 2022. The 2 main efficacy outcomes were a composite of arterial thrombotic events and venous thromboembolic events (VTEs). The main safety outcome was major bleeding. Random effects models with inverse variance were used.

RESULTS

Our search retrieved 253 studies. Four open-label randomized controlled trials involving 472 patients were included (mean control-arm time-in-therapeutic-range 60%). All had proper random sequence generation and adequate allocation concealment. Overall, the use of DOACs compared with VKAs was associated with increased odds of subsequent arterial thrombotic events (OR: 5.43; 95% CI: 1.87-15.75; P < 0.001, I2 = 0%), especially stroke, and the composite of arterial thrombotic events or VTE (OR: 4.46; 95% CI: 1.12-17.84; P = 0.03, I2 = 0%). The odds of subsequent VTE (OR: 1.20; 95% CI: 0.31-4.55; P = 0.79, I2 = 0%), or major bleeding (OR: 1.02; 95% CI: 0.42-2.47; P = 0.97; I2 = 0%) were not significantly different between the 2 groups. Most findings were consistent within subgroups.

CONCLUSIONS

Patients with thrombotic antiphospholipid syndrome randomized to DOACs compared with VKAs appear to have increased risk for arterial thrombosis. No significant differences were observed between patients randomized to DOACs vs VKAs in the risk of subsequent VTE or major bleeding.

ESHRE guideline: recurrent pregnancy loss: an update in 2022

STUDY QUESTION

What are the updates for the recommended management of women with recurrent pregnancy loss (RPL) based on the best available evidence in the literature from 2017 to 2022?

SUMMARY ANSWER

The guideline development group (GDG) updated 11 existing recommendations on investigations and treatments for RPL, and how care should be organized, and added one new recommendation on adenomyosis investigation in women with RPL.

WHAT IS KNOWN ALREADY

A previous ESHRE guideline on RPL was published in 2017 and needs to be updated.

STUDY DESIGN SIZE DURATION

The guideline was developed and updated according to the structured methodology for development and update of ESHRE guidelines. The literature searches were updated, and assessments of relevant new evidence were performed. Relevant papers published between 31 March 2017 and 28 February 2022 and written in English were included. Cumulative live birth rate, live birth rate, and pregnancy loss rate (or miscarriage rate) were considered the critical outcomes.

PARTICIPANTS/MATERIALS SETTING METHODS

Based on the collected evidence, recommendations were updated and discussed until consensus was reached within the GDG. A stakeholder review was organized after the updated draft was finalized. The final version was approved by the GDG and the ESHRE Executive Committee.

MAIN RESULTS AND THE ROLE OF CHANCE

The new version of the guideline provides 39 recommendations on risk factors, prevention, and investigation in couples with RPL, and 38 recommendations on treatments. These includes 62 evidence-based recommendations-of which 33 were formulated as strong recommendations and 29 as conditional-and 15 good practice points. Of the evidence-based recommendations, 12 (19.4%) were supported by moderate-quality evidence. The remaining recommendations were supported by low (34 recommendations; 54.8%), or very low-quality evidence (16 recommendations; 25.8%). Owing to the lack of evidence-based investigations and treatments in RPL care, the guideline also clearly mentions those investigations and treatments that should not be used for couples with RPL.

LIMITATIONS REASONS FOR CAUTION

The guidelines have been updated; however, several investigations and treatments currently offered to couples with RPL have not been well studied; for most of these investigations and treatments, a recommendation against using the intervention or treatment was formulated based on insufficient evidence. Future studies may require these recommendations to be revised.

WIDER IMPLICATIONS OF THE FINDINGS

The guideline provides clinicians with clear advice on best practice in RPL, based on the best and most recent evidence available. In addition, a list of research recommendations is provided to stimulate further studies in RPL. Still, the absence of a unified definition of RPL is one of the most critical consequences of the limited scientific evidence in the field.

STUDY FUNDING/COMPETING INTERESTS

The guideline was developed and funded by ESHRE, covering expenses associated with the guideline meetings, with the literature searches and with the dissemination of the guideline. The guideline group members did not receive payment.O.B.C. reports being a member of the executive board of the European Society for Reproductive Immunology and has received payment for honoraria for giving lectures about RPL in Australia in 2020. M.G. reports unconditional research and educational grant received by the Centre for Reproductive Medicine, Amsterdam UMC from Guerbet, Merck and Ferring, not related to the presented work. S.L. reports position funding from EXAMENLAB Ltd. and ownership interest by stock or partnership of EXAMENLAB Ltd (CEO). S.Q. reports being a deputy director of Tommy's National centre for miscarriage research, with payment received by the institution for research, staff time, and consumables for research. H.S.N. reports grants with payment to institution from Freya Biosciences ApS, Ferring Pharmaceuticals, BioInnovation Institute, the Danish ministry of Education, Novo Nordic Foundation, Augustinus Fonden, Oda og Hans Svenningsens Fond, Demant Fonden, Ole Kirks Fond, and Independent Research Fund Denmark and speakers' fees for lectures from Ferring Pharmaceuticals, Merck A/S, Astra Zeneca, IBSA Nordic and Cook Medical. She also reports to be an unpaid founder and chairman of a maternity foundation. M.-L.v.d.H. received small honoraria for lectures on RPL care. The other authors have no conflicts of interest to declare.

DISCLAIMER

This guideline represents the views of ESHRE, which were achieved after careful consideration of the scientific evidence available at the time of preparation. In the absence of scientific evidence on certain aspects, a consensus between the relevant ESHRE stakeholders has been obtained.Adherence to these clinical practice guidelines does not guarantee a successful or specific outcome, nor does it establish a standard of care. Clinical practice guidelines do not replace the need for application of clinical judgment to each individual presentation, nor variations based on locality and facility type.ESHRE makes no warranty, express or implied, regarding the clinical practice guidelines and specifically excludes any warranties of merchantability and fitness for a particular use or purpose. (Full disclaimer available at www.eshre.eu/guidelines.).

Use of the National Early Warning Score for predicting deterioration of patients with acute pulmonary embolism: a post-hoc analysis of the YEARS Study

BACKGROUND

The Pulmonary Embolism Severity Index (PESI) and the simplified PESI (sPESI) are validated scores for mortality prediction in patients with pulmonary embolism (PE). National Early Warning Score (NEWS) is a general prognostic risk score for multiple clinical settings. We investigated whether the NEWS had a comparable performance with the PESI and sPESI, for predicting intensive care unit (ICU) admission and death in patients with acute PE.

METHODS

In haemodynamically stable patients with confirmed PE from the YEARS Study (2013-2015), we evaluated the performance of the NEWS, PESI and sPESI for predicting 7-day ICU admission and 30-day mortality. Receiver operating characteristic curves were plotted and the area under the curve (AUC) was calculated.

RESULTS

Of 352 patients, 12 (3.4%) were admitted to the ICU and 5 (1.4%) died. The AUC of the NEWS for ICU admission was 0.80 (95% CI 0.66 to 0.94) and 0.92 (95% CI 0.82 to 1.00) for 30-day mortality. At a threshold of 3 points, NEWS yielded a sensitivity and specificity of 92% and 53% for ICU admission and 100% and 52% for 30-day mortality. The AUC of the PESI was 0.64 (95% CI 0.48 to 0.79) for ICU admission and 0.94 (95% CI 0.87 to 1.00) for mortality. At a threshold of 66 points, PESI yielded a sensitivity of 75% and a specificity of 38% for ICU admission. For mortality, these were 100% and 37%, respectively. The performance of the sPESI was similar to that of PESI.

CONCLUSION

In comparison with PESI and sPESI, NEWS adequately predicted 7-day ICU admission as well as 30-day mortality, supporting its potential relevance for clinical practice.

Onset of labor and use of analgesia in women using thromboprophylaxis with 2 doses of low-molecular-weight heparin: insights from the Highlow study

BACKGROUND

Peripartum management of women using low-molecular-weight heparin (LMWH) varies widely. Minimum time intervals are required between LMWH injection and neuraxial procedure, and they differ by dose.

OBJECTIVES

The objective of this study was to describe the onset of labor and use of analgesia in women using LMWH and to compare practices between intermediate-dose and low-dose LMWH.

METHODS

In the Highlow study (NCT01828697), 1110 women were randomized to intermediate-dose or low-dose LMWH and were instructed to discontinue LMWH when labor commenced unplanned or 24 hours prior to planned delivery. The required time interval since last injection to receive a neuraxial procedure was ≥24 hours for intermediate-dose LMWH or ≥12 hours for low-dose LMWH.

RESULTS

In total, 1018 women had an ongoing pregnancy for ≥24 weeks. Onset of labor was spontaneous in 198 of 509 (39%) women on intermediate-dose LMWH and in 246 of 509 (49%) on low-dose LMWH. With unplanned onset, a neuraxial procedure was performed in 37% on intermediate-dose and in 48% on low-dose LMWH (risk difference -11%, 95% CI -20% to -2%). Based on time interval, 61% on intermediate-dose and 82% on low-dose LMWH were eligible for a neuraxial procedure. With planned onset, 68% on intermediate-dose and 66% on low-dose LMWH received a neuraxial procedure, whereas 81% and 93%, respectively, were eligible for a neuraxial procedure (risk difference -13%, 95% CI -18% to -8%).

CONCLUSION

With spontaneous onset of labor, neuraxial procedures were performed less often in women using intermediate-dose LMWH. Irrespective of onset, fewer women on intermediate-dose LMWH than those on low-dose LMWH were eligible for neuraxial procedures based on required time intervals since the last LMWH injection.

The upper extremity postthrombotic syndrome score: an international Delphi consensus study to determine the score's functional disability component

Background

In upper extremity thrombosis research, the occurrence of upper extremity postthrombotic syndrome (UE-PTS) is commonly used as the main outcome parameter. However, there is currently no reporting standard or a validated method to assess UE-PTS presence and severity. In a recent Delphi study, consensus was reached on a preliminary UE-PTS score, combining 5 symptoms, 3 signs, and the inclusion of a functional disability score. However, no consensus was reached on which functional disability score to be included.

Objectives

The aim of the current Delphi consensus study was to determine the specific type of functional disability score to finalize UE-PTS score.

Methods

This Delphi project was designed as a three-round study using open text questions, statements with 7-point Likert scales, and multiple-choice questions. The CREDES recommendations for Delphi studies were applied. In this context, a systematic review was conducted before the start of the Delphi rounds to identify the available functional disability scores as available in the literature and present these to the expert panel.

Results

Thirty-five of 47 initially invited international experts from multiple disciplines completed all the Delphi rounds. In the second round, consensus was reached on the incorporation of the quick disabilities of the arm, shoulder, and hand (QuickDASH) in the UE-PTS score, rendering the third round obsolete.

Conclusion

Consensus was reached that the QuickDASH should be incorporated in the UE-PTS score. The UE-PTS score will need to be validated in a large cohort of patients with upper extremity thrombosis before it can be used in clinical practice and future research.

[Factor XI inhibitors: the holy grail of anticoagulant therapy?]

Direct-acting oral anticoagulants (DOAC's) have surpassed vitamin K antagonists (VKAs) as the preferred anticoagulant therapy in patients with non-valvular atrial fibrillation or venous thromboembolism. In most patients, the benefits of anticoagulant therapy, i.e. prevention of thromboembolism including stroke risk outweigh the risks of bleeding complications. However, in older and frail patients, uptake of DOAC's is limited by concerns of bleeding. Recent developments, with therapeutics that specifically target factor XI, carry a promise to be a game changer. Activated factor XI is thought to contribute to clot progression and thrombosis, but has only a minor effect on clot consolidation during hemostasis. In this paper we will discuss the latest findings of clinical studies on factor XI inhibitors and speculate on future perspectives, including the proposal to use consistent terminology for this emerging class of DOAC's.

The role of the intestinal microbiome in antiphospholipid syndrome

The antiphospholipid syndrome (APS) is a thrombotic autoimmune disease in which the origin of the disease-characterizing autoantibodies is unknown. Increased research effort into the role of the intestinal microbiome in autoimmunity has produced new insights in this field. This scoping review focusses on the gut microbiome in its relation to APS. EMBASE and MEDLINE were searched for original studies with relevance to the relation between the gut microbiome and APS. Thirty studies were included. Work on systemic lupus erythematosus, which strongly overlaps with APS, has shown that patients often display an altered gut microbiome composition, that the disease is transferable with the microbiome, and that microbiome manipulation affects disease activity in murine lupus models. The latter has also been shown for APS, although data on microbiome composition is less consistent. APS patients do display an altered intestinal IgA response. Evidence has accrued for molecular mimicry as an explanatory mechanism for these observations in APS and other autoimmune diseases. Specific gut microbes express proteins with homology to immunodominant APS autoantigens. The disease phenotype appears to be dependent on these mimicking proteins in an APS mouse model, and human APS B- and T-cells indeed cross-react with these mimics. Pre-clinical evidence furthermore suggests that diet may influence autoimmunity through the microbiome, as may microbial short chain fatty acid production, though this has not been studied in APS. Lastly, the microbiome has been shown to affect key drivers of thrombosis, and may thus affect APS severity through non-immunological mechanisms. Overall, these observations demonstrate the impact of the intestinal microbiome on autoimmunity and the importance of understanding its role in APS.

Intermediate-dose versus low-dose low-molecular-weight heparin in pregnant and post-partum women with a history of venous thromboembolism (Highlow study): an open-label, multicentre, randomised, controlled trial

BACKGROUND

Pregnancy-related venous thromboembolism is a leading cause of maternal morbidity and mortality, and thromboprophylaxis is indicated in pregnant and post-partum women with a history of venous thromboembolism. The optimal dose of low-molecular-weight heparin to prevent recurrent venous thromboembolism in pregnancy and the post-partum period is uncertain.

METHODS

In this open-label, randomised, controlled trial (Highlow), pregnant women with a history of venous thromboembolism were recruited from 70 hospitals in nine countries (the Netherlands, France, Ireland, Belgium, Norway, Denmark, Canada, the USA, and Russia). Women were eligible if they were aged 18 years or older with a history of objectively confirmed venous thromboembolism, and with a gestational age of 14 weeks or less. Eligible women were randomly assigned (1:1), before 14 weeks of gestational age, using a web-based system and permuted block randomisation (block size of six), stratified by centre, to either weight-adjusted intermediate-dose or fixed low-dose low-molecular-weight heparin subcutaneously once daily until 6 weeks post partum. The primary efficacy outcome was objectively confirmed venous thromboembolism (ie, deep-vein thrombosis, pulmonary embolism, or unusual site venous thrombosis), as determined by an independent central adjudication committee, in the intention-to-treat (ITT) population (ie, all women randomly assigned to treatment). The primary safety outcome was major bleeding which included antepartum, early post-partum (within 24 h after delivery), and late post-partum major bleeding (24 h or longer after delivery until 6 weeks post partum), assessed in all women who received at least one dose of assigned treatment and had a known end of treatment date. This study is registered with ClinicalTrials.gov, NCT01828697, and is now complete.

FINDINGS

Between April 24, 2013, and Oct 31, 2020, 1339 pregnant women were screened for eligibility, of whom 1110 were randomly assigned to weight-adjusted intermediate-dose (n=555) or fixed low-dose (n=555) low-molecular-weight heparin (ITT population). Venous thromboembolism occurred in 11 (2%) of 555 women in the weight-adjusted intermediate-dose group and in 16 (3%) of 555 in the fixed low-dose group (relative risk [RR] 0·69 [95% CI 0·32-1·47]; p=0·33). Venous thromboembolism occurred antepartum in five (1%) women in the intermediate-dose group and in five (1%) women in the low-dose group, and post partum in six (1%) women and 11 (2%) women. On-treatment major bleeding in the safety population (N=1045) occurred in 23 (4%) of 520 women in the intermediate-dose group and in 20 (4%) of 525 in the low-dose group (RR 1·16 [95% CI 0·65-2·09]).

INTERPRETATION

In women with a history of venous thromboembolism, weight-adjusted intermediate-dose low-molecular-weight heparin during the combined antepartum and post-partum periods was not associated with a lower risk of recurrence than fixed low-dose low-molecular-weight heparin. These results indicate that low-dose low-molecular-weight heparin for thromboprophylaxis during pregnancy is the appropriate dose for the prevention of pregnancy-related recurrent venous thromboembolism.

FUNDING

French Ministry of Health, Health Research Board Ireland, GSK/Aspen, and Pfizer.

Transgender Medicine and Risk of Venous Thromboembolism

Gender dysphoria refers to psychological distress that results from an incongruence between gender identity and sex assigned at birth. Administration of sex hormones is most often used as a first step to develop and maintain physical characteristics consistent with gender identity. Gender-affirming hormone treatment is considered beneficial for the quality of life and reduction of depression. However, estrogen and androgen-lowering hormone therapies used in transwomen are in particular associated with increased risk of venous thromboembolism. In this review, introduced by a clinical case, we provide an overview of the currently available medical therapies in transgender medicine, and put the associated increased risk of venous thromboembolism into perspective.

ISTH guidelines for antithrombotic treatment in COVID-19

Antithrombotic agents reduce risk of thromboembolism in severely ill patients. Patients with coronavirus disease 2019 (COVID-19) may realize additional benefits from heparins. Optimal dosing and timing of these treatments and benefits of other antithrombotic agents remain unclear. In October 2021, ISTH assembled an international panel of content experts, patient representatives, and a methodologist to develop recommendations on anticoagulants and antiplatelet agents for patients with COVID-19 in different clinical settings. We used the American College of Cardiology Foundation/American Heart Association methodology to assess level of evidence (LOE) and class of recommendation (COR). Only recommendations with LOE A or B were included. Panelists agreed on 12 recommendations: three for non-hospitalized, five for non-critically ill hospitalized, three for critically ill hospitalized, and one for post-discharge patients. Two recommendations were based on high-quality evidence, the remainder on moderate-quality evidence. Among non-critically ill patients hospitalized for COVID-19, the panel gave a strong recommendation (a) for use of prophylactic dose of low molecular weight heparin or unfractionated heparin (LMWH/UFH) (COR 1); (b) for select patients in this group, use of therapeutic dose LMWH/UFH in preference to prophylactic dose (COR 1); but (c) against the addition of an antiplatelet agent (COR 3). Weak recommendations favored (a) sulodexide in non-hospitalized patients, (b) adding an antiplatelet agent to prophylactic LMWH/UFH in select critically ill, and (c) prophylactic rivaroxaban for select patients after discharge (all COR 2b). Recommendations in this guideline are based on high-/moderate-quality evidence available through March 2022. Focused updates will incorporate future evidence supporting changes to these recommendations.

A short review of ciraparantag in perspective of the currently available anticoagulant reversal agents

Despite the improved safety-profile of direct oral anticoagulants (DOACs), bleeding complications remain an important side effect of anticoagulant treatment. Although anticoagulant-specific antidotes are available, an universal anticoagulant reversal agent in case of life-threatening bleeding or emergency surgery is not yet available. Ciraparantag, a synthetic small molecule that inactivates heparins and DOAC, is a promising new reversal agent that has been investigated in phase 2 trials. In this short review we provide an overview of the preclinical and clinical evidence of ciraparantag, and compare strengths and weaknesses of ciraparantag and the currently available anticoagulant reversal strategies.

Outcomes of Cerebral Venous Thrombosis due to Vaccine-Induced Immune Thrombotic Thrombocytopenia After the Acute Phase

BACKGROUND

Cerebral venous thrombosis (CVT) due to vaccine-induced immune thrombotic thrombocytopenia (VITT) is a severe condition, with high in-hospital mortality rates. Here, we report clinical outcomes of patients with CVT-VITT after SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) vaccination who survived initial hospitalization.

METHODS

We used data from an international registry of patients who developed CVT within 28 days of SARS-CoV-2 vaccination, collected until February 10, 2022. VITT diagnosis was classified based on the Pavord criteria. Outcomes were mortality, functional independence (modified Rankin Scale score 0-2), VITT relapse, new thrombosis, and bleeding events (all after discharge from initial hospitalization).

RESULTS

Of 107 CVT-VITT cases, 43 (40%) died during initial hospitalization. Of the remaining 64 patients, follow-up data were available for 60 (94%) patients (37 definite VITT, 9 probable VITT, and 14 possible VITT). Median age was 40 years and 45/60 (75%) patients were women. Median follow-up time was 150 days (interquartile range, 94-194). Two patients died during follow-up (3% [95% CI, 1%-11%). Functional independence was achieved by 53/60 (88% [95% CI, 78%-94%]) patients. No new venous or arterial thrombotic events were reported. One patient developed a major bleeding during follow-up (fatal intracerebral bleed).

CONCLUSIONS

In contrast to the high mortality of CVT-VITT in the acute phase, mortality among patients who survived the initial hospitalization was low, new thrombotic events did not occur, and bleeding events were rare. Approximately 9 out of 10 CVT-VITT patients who survived the acute phase were functionally independent at follow-up.

Diagnostic efficacy of ECG-derived ventricular gradient for the detection of chronic thromboembolic pulmonary hypertension in patients with acute pulmonary embolism

INTRODUCTION

Application of the chronic thromboembolic pulmonary hypertension (CTEPH) rule out criteria (manual electrocardiogram [ECG] reading and N-terminal pro-brain natriuretic peptide [NTproBNP] test) can rule out CTEPH in pulmonary embolism (PE) patients with persistent dyspnea (InShape II algorithm). Increased pulmonary pressure may also be identified using automated ECG-derived ventricular gradient optimized for right ventricular pressure overload (VG-RVPO).

METHOD

A predefined analysis of the InShape II study was performed. The diagnostic performance of the VG-RVPO for the detection of CTEPH and the incremental diagnostic value of the VG-RVPO as new rule-out criteria in the InShape II algorithm were evaluated.

RESULTS

60 patients were included; 5 (8.3%) were ultimately diagnosed with CTEPH. The mean baseline VG-RVPO (at time of PE diagnosis) was -18.12 mV·ms for CTEPH patients and - 21.57 mV·ms for non-CTEPH patients (mean difference 3.46 mV·ms [95%CI -29.03 to 35.94]). The VG-RVPO (after 3-6 months follow-up) normalized in patients with and without CTEPH, without a clear between-group difference (mean Δ VG-RVPO of -8.68 and - 8.42 mV·ms respectively; mean difference of -0.25 mV·ms, [95%CI -12.94 to 12.44]). The overall predictive accuracy of baseline VG-RVPO, follow-up RVPO and Δ VG-RVPO for CTEPH was moderate to poor (ROC AUC 0.611, 0.514 and 0.539, respectively). Up to 76% of the required echocardiograms could have been avoided with VG-RVPO criteria replacing the InShape II rule-out criteria, however at cost of missing up to 80% of the CTEPH diagnoses.

CONCLUSION

We could not demonstrate (additional) diagnostic value of VG-RVPO as standalone test or as on top of the InShape II algorithm.

Post-thrombotic syndrome after upper extremity deep vein thrombosis: An international Delphi consensus study

OBJECTIVES

Primary deep vein thrombosis of the upper extremity (UEDVT) is a rare condition but up to 60% of patients may develop post-thrombotic syndrome in the upper extremity (UE-PTS) with significant morbidity and decreased quality of life. However, there is no universally accepted method to diagnose and classify UE-PTS, hampering scientific research on UEDVT treatment. Through this international Delphi consensus study we aimed to determine what a clinical score for diagnosing UE-PTS should entail.

METHODS

An online focus group survey among 20 patients treated for UEDVT was performed to provide clinical parameters before the start of a four round electronic Delphi consensus study among 25 international experts. The CREDES recommendations on Conducting and Reporting Delphi Studies were applied. Open text questions, multiple selection questions, and 9-point Likert scales were used. Consensus was set at 70% agreement.

RESULTS

After four rounds, agreement was reached on a composite score of five symptoms and three clinical signs, combined with a functional disability score. The signs and symptom will each be scored on a severity scale of 0-3 and the total score expressed as an ordinal variable; no/mild/moderate/or severe PTS. The functional disability portion measures the impact of the signs and symptoms on the functionality of the patient's arm.

CONCLUSION

Consensus was reached on a composite score of signs and symptoms of UE-PTS combined with a functional disability score. Clinical validation of the UE-PTS score in a large patient cohort is mandatory to facilitate application in future research.

Postthrombotic syndrome and quality of life after deep vein thrombosis in patients treated with edoxaban versus warfarin

Background

Postthrombotic syndrome (PTS) is a long-term complication after deep vein thrombosis (DVT) and can affect quality of life (QoL). Pathogenesis is not fully understood but inadequate anticoagulant therapy with vitamin K antagonists is a known risk factor for the development of PTS.

Objectives

To compare the prevalence of PTS after acute DVT and the long-term QoL following DVT between patients treated with edoxaban or warfarin.

Methods

We performed a long-term follow-up study in a subset of patients with DVT who participated in the Hokusai-VTE trial between 2010 and 2012 (NCT00986154). Primary outcome was the prevalence of PTS, defined by the Villalta score. The secondary outcome was QoL, assessed by validated disease-specific (VEINES-QOL) and generic health-related (SF-36) questionnaires.

Results

Between 2017 and 2020, 316 patients were enrolled in 26 centers in eight countries, of which 168 (53%) patients had been assigned to edoxaban and 148 (47%) to warfarin during the Hokusai-VTE trial. Clinical, demographic, and thrombus-specific characteristics were comparable for both groups. Mean (SD) time since randomization in the Hokusai-VTE trial was 7.0 (1.0) years. PTS was diagnosed in 85 (51%) patients treated with edoxaban and 62 (42%) patients treated with warfarin (adjusted odds ratio 1.6, 95% CI 1.0-2.6). Mean differences in QoL scores between treatment groups were not clinically relevant.

Conclusion

Contrary to our hypothesis, the prevalence of PTS tended to be higher in patients treated with edoxaban compared with warfarin. No differences in QoL were observed. Further research is warranted to unravel the role of anticoagulant therapy on development of PTS.

Management of Cerebral Venous Thrombosis Due to Adenoviral COVID-19 Vaccination

Objective

Cerebral venous thrombosis (CVT) caused by vaccine‐induced immune thrombotic thrombocytopenia (VITT) is a rare adverse effect of adenovirus‐based severe acute respiratory syndrome‐coronavirus 2 (SARS‐CoV‐2) vaccines. In March 2021, after autoimmune pathogenesis of VITT was discovered, treatment recommendations were developed. These comprised immunomodulation, non‐heparin anticoagulants, and avoidance of platelet transfusion. The aim of this study was to evaluate adherence to these recommendations and its association with mortality.

Methods

We used data from an international prospective registry of patients with CVT after the adenovirus‐based SARS‐CoV‐2 vaccination. We analyzed possible, probable, or definite VITT‐CVT cases included until January 18, 2022. Immunomodulation entailed administration of intravenous immunoglobulins and/or plasmapheresis.

Results

Ninety‐nine patients with VITT‐CVT from 71 hospitals in 17 countries were analyzed. Five of 38 (13%), 11 of 24 (46%), and 28 of 37 (76%) of the patients diagnosed in March, April, and from May onward, respectively, were treated in‐line with VITT recommendations (p < 0.001). Overall, treatment according to recommendations had no statistically significant influence on mortality (14/44 [32%] vs 29/55 [52%], adjusted odds ratio [OR] = 0.43, 95% confidence interval [CI] = 0.16–1.19). However, patients who received immunomodulation had lower mortality (19/65 [29%] vs 24/34 [70%], adjusted OR = 0.19, 95% CI = 0.06–0.58). Treatment with non‐heparin anticoagulants instead of heparins was not associated with lower mortality (17/51 [33%] vs 13/35 [37%], adjusted OR = 0.70, 95% CI = 0.24–2.04). Mortality was also not significantly influenced by platelet transfusion (17/27 [63%] vs 26/72 [36%], adjusted OR = 2.19, 95% CI = 0.74–6.54).

Conclusions

In patients with VITT‐CVT, adherence to VITT treatment recommendations improved over time. Immunomodulation seems crucial for reducing mortality of VITT‐CVT. ANN NEUROL 2022;92:562–573

Ultra-low-dose CT versus chest X-ray for patients suspected of pulmonary disease at the emergency department: a multicentre randomised clinical trial

BACKGROUND

Chest CT displays chest pathology better than chest X-ray (CXR). We evaluated the effects on health outcomes of replacing CXR by ultra-low-dose chest-CT (ULDCT) in the diagnostic work-up of patients suspected of non-traumatic pulmonary disease at the emergency department.

METHODS

Pragmatic, multicentre, non-inferiority randomised clinical trial in patients suspected of non-traumatic pulmonary disease at the emergency department. Between 31 January 2017 and 31 May 2018, every month, participating centres were randomly allocated to using ULDCT or CXR. Primary outcome was functional health at 28 days, measured by the Short Form (SF)-12 physical component summary scale score (PCS score), non-inferiority margin was set at 1 point. Secondary outcomes included hospital admission, hospital length of stay (LOS) and patients in follow-up because of incidental findings.

RESULTS

2418 consecutive patients (ULDCT: 1208 and CXR: 1210) were included. Mean SF-12 PCS score at 28 days was 37.0 for ULDCT and 35.9 for CXR (difference 1.1; 95% lower CI: 0.003). After ULDCT, 638/1208 (52.7%) patients were admitted (median LOS of 4.8 days; IQR 2.1-8.8) compared with 659/1210 (54.5%) patients after CXR (median LOS 4.6 days; IQR 2.1-8.8). More ULDCT patients were in follow-up because of incidental findings: 26 (2.2%) versus 4 (0.3%).

CONCLUSIONS

Short-term functional health was comparable between ULDCT and CXR, as were hospital admissions and LOS, but more incidental findings were found in the ULDCT group. Our trial does not support routine use of ULDCT in the work-up of patients suspected of non-traumatic pulmonary disease at the emergency department.

TRIAL REGISTRATION NUMBER

NTR6163.

Effect of polypharmacy on bleeding with rivaroxaban versus vitamin K antagonist for treatment of venous thromboembolism

BACKGROUND

Polypharmacy, including use of inhibitors of CYP3A4 and P-glycoprotein (P-gp), is common in patients with venous thromboembolism (VTE) and is associated with increased bleeding.

METHODS

In 8246 patients included in the EINSTEIN-VTE studies for acute VTE, we evaluated the effect of polypharmacy on bleeding and on the relative differences between rivaroxaban and enoxaparin/vitamin K antagonist (VKA). We assessed the incidence of clinically relevant bleeding (major and clinically relevant nonmajor bleeding) by number of comedications (none, 1-3, ≥4) at baseline, and by use of CYP3A4 and/or P-gp inhibitors. Interaction between rivaroxaban versus enoxaparin/VKA and comedication was assessed by Cox regression analysis with pinteraction estimates.

RESULTS

With increasing number of comedications, the incidence of clinically relevant bleeding rose from 5.7% to 13.3% in rivaroxaban recipients and from 9.1% to 11.1% in enoxaparin/VKA recipients. Whereas rivaroxaban was associated with a reduced bleeding risk compared with enoxaparin/VKA in patients without comedication (hazard ratio [HR] 0.6, 95% confidence interval [CI] 0.4-0.9), the risk was similar in patients with ≥4 comedications (HR 1.2, 95% CI 0.97-1.5, pinteraction .002). Use of CYP3A4 and/or P-gp inhibitors was associated with a doubled bleeding risk compared with no use, without a difference between rivaroxaban and enoxaparin/VKA.

CONCLUSION

We conclude that fixed-dose rivaroxaban as compared with enoxaparin followed by dose-adjusted VKA is not associated with an increased bleeding risk in patients with VTE administered polypharmacy in general and CYP3A4 and/or P-gp inhibitors specifically. This implies that the observed increased bleeding risks with polypharmacy and use of CYP3A4 and/or P-gp inhibitors are likely explained by comorbidities and frailty, and not by pharmacokinetic interactions.

Differences in thrombin and plasmin generation potential between East African and Western European adults: The role of genetic and non-genetic factors

BACKGROUND

Geographic variability in coagulation across populations and their determinants are poorly understood.

OBJECTIVE

To compare thrombin (TG) and plasmin (PG) generation parameters between healthy Tanzanian and Dutch individuals, and to study associations with inflammation and different genetic, host and environmental factors.

METHODS

TG and PG parameters were measured in 313 Tanzanians of African descent living in Tanzania and 392 Dutch of European descent living in the Netherlands and related to results of a dietary questionnaire, circulating inflammatory markers, genotyping, and plasma metabolomics.

RESULTS

Tanzanians exhibited an enhanced TG and PG capacity, compared to Dutch participants. A higher proportion of Tanzanians had a TG value in the upper quartile with a PG value in the lower/middle quartile, suggesting a relative pro-coagulant state. Tanzanians also displayed an increased normalized thrombomodulin sensitivity ratio, suggesting reduced sensitivity to protein C. In Tanzanians, PG parameters (lag time and TTP) were associated with seasonality and food-derived plasma metabolites. The Tanzanians had higher concentrations of pro-inflammatory cytokines, which correlated strongly with TG and PG parameters. There was limited overlap in genetic variation associated with TG and PG parameters between the two cohorts. Pathway analysis of genetic variants in the Tanzanian cohort revealed multiple immune pathways that were enriched with TG and PG traits, confirming the importance of co-regulation between coagulation and inflammation.

CONCLUSIONS

Tanzanians have an enhanced TG and PG potential compared to Dutch individuals, which may relate to differences in inflammation, genetics and diet. These observations highlight the importance of better understanding of the geographic variability in coagulation across populations.

Risk of recurrence in women with venous thromboembolism related to estrogen-containing contraceptives: Systematic review and meta-analysis

BACKGROUND

The risk of recurrence after a venous thromboembolism (VTE) related to estrogen-containing contraceptives is a key driver to guide anticoagulant treatment decisions.

OBJECTIVE

To estimate the incidence rate of recurrent VTE after discontinuation of anticoagulant treatment in women with a first episode of VTE related to estrogen-containing contraceptives.

METHODS

Embase, MEDLINE, and the CENTRAL were searched from 1 January 2008 to 27 May 2021 for prospective and retrospective studies reporting on recurrence after a first VTE related to estrogen-containing contraceptives. Risk of bias was assessed using QUIPS tool. Recurrence rates per 100 patient-years were pooled using Knapp-Hartung random-effects meta-analysis. Incidence rates were reported separately based on study follow-up duration (≤1 year, 1-5 years, and >5 years) and for several subgroups.

RESULTS

A total of 4,120 studies were identified, of which 14 were included. The pooled recurrence rate was 1.57 (95%-CI: 1.10-2.23; I2  = 82%) per 100 patient-years. Recurrence rates per 100 patient-years were 2.73 (95%-CI: 0.00-3643; I2  = 80%) for studies with ≤1 year follow-up, 1.35 (95%-CI: 0.68-2.68; I2  = 44%) for studies with 1-5 years follow-up, and 1.42 (95%-CI: 0.84-2.42; I2  = 78%) for studies with >5 years follow-up.

CONCLUSION

Among women with VTE associated with estrogen-containing contraceptives, the risk of recurrence after stopping anticoagulation is low, which favors short-term anticoagulation. Large prospective studies on VTE recurrence rates and risk factors after stopping short-term anticoagulants are needed.

Effect of Antiplatelet Therapy on Survival and Organ Support-Free Days in Critically Ill Patients With COVID-19: A Randomized Clinical Trial

Importance

The efficacy of antiplatelet therapy in critically ill patients with COVID-19 is uncertain.

Objective

To determine whether antiplatelet therapy improves outcomes for critically ill adults with COVID-19.

Design, Setting, and Participants

In an ongoing adaptive platform trial (REMAP-CAP) testing multiple interventions within multiple therapeutic domains, 1557 critically ill adult patients with COVID-19 were enrolled between October 30, 2020, and June 23, 2021, from 105 sites in 8 countries and followed up for 90 days (final follow-up date: July 26, 2021).

Interventions

Patients were randomized to receive either open-label aspirin (n = 565), a P2Y12 inhibitor (n = 455), or no antiplatelet therapy (control; n = 529). Interventions were continued in the hospital for a maximum of 14 days and were in addition to anticoagulation thromboprophylaxis.

Main Outcomes and Measures

The primary end point was organ support-free days (days alive and free of intensive care unit-based respiratory or cardiovascular organ support) within 21 days, ranging from -1 for any death in hospital (censored at 90 days) to 22 for survivors with no organ support. There were 13 secondary outcomes, including survival to discharge and major bleeding to 14 days. The primary analysis was a bayesian cumulative logistic model. An odds ratio (OR) greater than 1 represented improved survival, more organ support-free days, or both. Efficacy was defined as greater than 99% posterior probability of an OR greater than 1. Futility was defined as greater than 95% posterior probability of an OR less than 1.2 vs control. Intervention equivalence was defined as greater than 90% probability that the OR (compared with each other) was between 1/1.2 and 1.2 for 2 noncontrol interventions.

Results

The aspirin and P2Y12 inhibitor groups met the predefined criteria for equivalence at an adaptive analysis and were statistically pooled for further analysis. Enrollment was discontinued after the prespecified criterion for futility was met for the pooled antiplatelet group compared with control. Among the 1557 critically ill patients randomized, 8 patients withdrew consent and 1549 completed the trial (median age, 57 years; 521 [33.6%] female). The median for organ support-free days was 7 (IQR, -1 to 16) in both the antiplatelet and control groups (median-adjusted OR, 1.02 [95% credible interval {CrI}, 0.86-1.23]; 95.7% posterior probability of futility). The proportions of patients surviving to hospital discharge were 71.5% (723/1011) and 67.9% (354/521) in the antiplatelet and control groups, respectively (median-adjusted OR, 1.27 [95% CrI, 0.99-1.62]; adjusted absolute difference, 5% [95% CrI, -0.2% to 9.5%]; 97% posterior probability of efficacy). Among survivors, the median for organ support-free days was 14 in both groups. Major bleeding occurred in 2.1% and 0.4% of patients in the antiplatelet and control groups (adjusted OR, 2.97 [95% CrI, 1.23-8.28]; adjusted absolute risk increase, 0.8% [95% CrI, 0.1%-2.7%]; 99.4% probability of harm).

Conclusions and Relevance

Among critically ill patients with COVID-19, treatment with an antiplatelet agent, compared with no antiplatelet agent, had a low likelihood of providing improvement in the number of organ support-free days within 21 days.

Trial Registration

ClinicalTrials.gov Identifier: NCT02735707.