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

Extended thromboprophylaxis in heart failure patients; the unmet need

Heart failure (HF) is considered one of a leading cause of cardiovascular morbidity and mortality worldwide. The association between HF and venous thromboembolism (VTE) has been reported in several studies owing to many physiological and thromboembolic risk factors. Thus, the need for extended thromboprophylaxis during the post-discharge period in HF patients has been evaluated. Most guidelines do not recommend extended thromboprophylaxis because of its uncertain benefits and increased risk of bleeding. However, recent evidence in HF patients revealed no increased risk of bleeding with extended thromboprophylaxis, which highlights the importance of identifying ideal candidates who might benefit from extended thromboprophylaxis. Several risk assessment models (RAMs) have been developed to identify patients at a high risk of VTE who would benefit from in-hospital and post-discharge prophylactic anticoagulation therapy based on the risk-benefit principle. However, their accuracy in predicting VTE is questionable, and none have a standardized approach for evaluating the risk of VTE in HF patients. In this review, we provided an overview of the incidence and pathophysiology of VTE in HF patients, a summary of guideline recommendations for VTE prevention, and a summary of studies evaluating the use of extended thromboprophylaxis, with a focus on subgroup or post-hoc analyses of HF patients. We also discussed the need to design an ideal RAM that can identify candidate patients for extended thromboprophylaxis by stratifying the risk of VTE and identifying the key risk factors for bleeding in medically ill patients, including those with HF.

Rivaroxaban for Prevention of Thrombotic Events, Hospitalization, and Death in Outpatients With COVID-19: A Randomized Clinical Trial

BACKGROUND

COVID-19 (coronavirus disease 2019) is associated with heightened risks of venous and arterial thrombosis and hospitalization due to respiratory failure. To assess whether prophylactic anticoagulation can safely reduce the frequency of venous and arterial thrombosis, hospitalization, and death in nonhospitalized patients with symptomatic COVID-19 and at least one thrombosis risk factor, we conducted the PREVENT-HD double-blind, placebo-controlled randomized trial (A Study of Rivaroxaban to Reduce the Risk of Major Venous and Arterial Thrombotic Events, Hospitalization and Death in Medically Ill Outpatients With Acute, Symptomatic COVID-19] Infection).

METHODS

PREVENT-HD was conducted between August 2020 and April 2022 at 14 US integrated health care delivery networks. A virtual trial design used remote informed consent and clinical monitoring and facilitated data collection through electronic health record integration with a cloud-based research platform. Nonhospitalized patients with symptomatic COVID-19 and at least one thrombosis risk factor were enrolled and randomly assigned to either 10 mg of oral rivaroxaban or placebo daily for 35 days. The primary efficacy outcome was time to first occurrence of a composite of symptomatic venous thromboembolism, myocardial infarction, ischemic stroke, acute limb ischemia, non-central nervous system systemic arterial embolism, hospitalization, or death through day 35. The principal safety end point was International Society on Thrombosis and Hemostasis critical-site or fatal bleeding. The last study visit was on day 49.

RESULTS

The study was terminated prematurely because of enrollment challenges and a lower-than-expected blinded pooled event rate. A total of 1284 patients underwent randomization with complete accrual of primary events through May 2022. No patients were lost to follow-up. The primary efficacy outcome occurred in 22 of 641 in the rivaroxaban group and 19 of 643 in the placebo group (3.4% versus 3.0%; hazard ratio, 1.16 [95% CI, 0.63-2.15]; P=0.63). No patient in either group experienced critical-site or fatal bleeding. One patient receiving rivaroxaban had a major bleed.

CONCLUSIONS

The study was terminated prematurely after enrollment of 32% of planned accrual because of recruitment challenges and lower-than-expected event rate. Rivaroxaban prescribed for 35 days in nonhospitalized patients with symptomatic COVID-19 at risk for thrombosis did not appear to reduce a composite end point of venous and arterial thrombotic events, hospitalization, and death.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04508023.

Current and emerging drug strategies for the prevention of venous thromboembolism in acutely ill medical inpatients

INTRODUCTION

Venous thromboembolism (VTE) is a common complication in patients hospitalized for acute medical illnesses. Therefore, medical inpatients require a careful VTE and bleeding risk assessment to drive optimal strategies for VTE prevention. Low molecular weight heparin and fondaparinux have long been used for inhospital prophylaxis for patients at increased risk of VTE. The selection of patients who require post-discharge prophylaxis, and the role of direct oral anticoagulants remain debated. New molecules currently under development may contribute to improve the risk benefit of VTE prevention in this setting.

AREAS COVERED

This text summarizes the evidence on approved treatments and on other drugs for the prevention of VTE in acutely ill medical patients. The main focus is on their pharmacological proprieties, clinical efficacy and safety, and the current license approved by the FDA (Food and Drug Administration) and EMA (European Medicines Agency), giving the readers a way to compare available drugs to date. The trials presented consider both inhospital and extended prophylaxis.

EXPERT OPINION

Thanks to the potentially favorable safety profile, factor XI inhibitors may play a role in the prevention of VTE in this setting. The expert opinion section discusses pharmacological properties, prophylaxis trials, and potential clinical applications of this novel class of drugs.

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.

In-hospital venous thromboembolism: are glucocorticoids a prime suspect?

The objective of the study was to determine whether glucocorticoid use is associated with an increased incidence of in-hospital VTE. We conducted a case-control study of patients with an in-hospital VTE from October 2015 to December 2019. Adult patient cases were identified by ICD-10 codes for acute venous thromboembolism. Controls were selected from all patients without a VTE diagnosis and matched by hospital length of stay and admission type (medical/surgical). Patients were excluded if they had a history of VTE, received therapeutic anticoagulation, or were pregnant. All patients were evaluated to determine the presence or absence of glucocorticoid exposure. Glucocorticoid dose, duration, and route of administration were assessed for patients with steroid exposure. Overall, 78 patients with VTE and 234 controls were included. Receipt of glucocorticoids within the preceding 90 days was similar between the VTE cases and controls (39.7 vs. 38.9%, P  = 0.89). No differences were noted with regard to oral (21.8 vs. 19.2%, P = 0.62), intravenous (30.8 vs. 29.1%. P = 0.774), or inhaled (6.4 vs. 10.3%, P = 0.31) routes of administration between VTE case and control patients. Cumulative prednisone equivalent doses were similar between cases and controls (877 ± 1366 vs. 697 ± 1963 mg, P = 0.435). The risk of in-hospital venous thromboembolism was not influenced by glucocorticoid exposure within the past 90 days. These results were consistent across all routes of administration, exposure time, and steroid dose. Blood Coagul Fibrinolysis 33:000-000 Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.

Efficacy and Safety Considerations With Dose-Reduced Direct Oral Anticoagulants: A Review

Importance

Dose-reduced regimens of direct oral anticoagulants (DOACs) may be used for 2 main purposes: dose-adjusted treatment intended as full-intensity anticoagulation (eg, for stroke prevention in atrial fibrillation [AF] in patients requiring dose reduction) or low-intensity treatment (eg, extended-duration treatment of venous thromboembolism [VTE]). We reviewed randomized clinical trials (RCTs) to understand the scenarios in which dose-adjusted or low-intensity DOACs were tested and reviewed the labeled indications by regulatory authorities, using data from large registries to assess whether the use of dose-reduced DOACs in routine practice aligned with the findings of RCTs.

Observations

Among 4191 screened publications, 35 RCTs that used dose-adjusted DOACs were identified for dabigatran, apixaban, rivaroxaban, and edoxaban. Of these 35 RCTs, 29 were related to stroke prevention in AF. Efficacy and safety results for dose-adjusted DOACs in large RCTs of AF were similar to those found for full-dose DOACs. To our knowledge, dabigatran, apixaban, and rivaroxaban have not been studied as dose-adjusted therapy for acute VTE treatment. Low-intensity DOACs were identified in 37 RCTs. Low-intensity DOACs may be used for extended-duration treatment of VTE (apixaban and rivaroxaban), primary prevention in orthopedic surgeries (dabigatran, apixaban, and rivaroxaban), primary prevention in ambulatory high-risk cancer patients (apixaban and rivaroxaban) or (postdischarge) high-risk medical patients (rivaroxaban), in stable atherosclerotic vascular disease, or after a recent revascularization for peripheral artery disease in conjunction with aspirin (rivaroxaban). Minor variations exist between regulatory authorities in different regions regarding criteria for dose adjustment of DOACs. Data from large registries indicated that dose-reduced DOACs were used occasionally with doses or for clinical scenarios different from those studied in RCTs or recommended by regulatory authorities.

Conclusions and Relevance

Dose adjustment and low-intensity treatment are 2 different forms of dose-reduced DOACs. Dose adjustment is mostly relevant for AF and should be done based on the approved criteria. Dose adjustment of DOACs should not be used for acute VTE treatment in most cases. In contrast, low-intensity DOACs may be used for primary or secondary VTE prevention for studied and approved indications. Attention should be given to routine practice patterns to align the daily clinical practice with existing evidence of safety and efficacy.

Thromboembolic prevention and anticoagulant therapy during the COVID-19 pandemic: updated clinical guidance from the anticoagulation forum

Thromboembolism is a common and deadly consequence of COVID-19 infection for hospitalized patients. Based on clinical evidence pre-dating the COVID-19 pandemic and early observational reports, expert consensus and guidance documents have strongly encouraged the use of prophylactic anticoagulation for patients hospitalized for COVID-19 infection. More recently, multiple clinical trials and larger observational studies have provided evidence for tailoring the approach to thromboprophylaxis for patients with COVID-19. This document provides updated guidance for the use of anticoagulant therapies in patients with COVID-19 from the Anticoagulation Forum, the leading North American organization of anticoagulation providers. We discuss ambulatory, in-hospital, and post-hospital thromboprophylaxis strategies as well as provide guidance for patients with thrombotic conditions who are considering COVID-19 vaccination.

Association of Bleeding Severity with Mortality in Extended Thromboprophylaxis of Medically Ill Patients in the MAGELLAN and MARINER Trials

Background: Extended thromboprophylaxis has not been widely implemented in acutely ill medical patients due to bleeding concerns. The MAGELLAN and MARINER trials evaluated whether rivaroxaban compared with enoxaparin or placebo could prevent venous thromboembolism (VTE) without increased bleeding. We hypothesized that patients with major bleeding (MB) but not those with non-major clinically relevant bleeding (NMCRB), would be at an increased risk of all-cause mortality (ACM). Methods: We evaluated all bleeding events in patients taking at least one dose of study drug and their association with ACM in 4 mutually exclusive groups: (1) no bleeding, or first event was (2) NMCRB, (3) MB, or (4) trivial bleeding. Using a Cox proportional hazards model adjusted for differences in baseline characteristics associated with ACM, we assessed the risk of ACM after such events. Results: Compared to patients with no bleeding, the risk of ACM for patients with NMCRB was not increased in MARINER (HR 0.43, p=0.235) but was increased in MAGELLAN (HR 1.74 p=0.021). MB was associated with a higher incidence of ACM in both studies, while trivial bleeding was not associated with ACM in either study. Conclusions: Patients with MB had an increased risk of ACM, while NMCRB was not consistently associated with an increased risk of death. These results inform the risk-benefit calculus of extended thromboprophylaxis in medically ill patients.

State-of-the-art-mini review: Dual pathway inhibition to reduce arterial and venous thromboembolism

Venous thromboembolism (VTE) and arterial thromboembolism (ATE) are linked by the common mechanism of thrombin generation. Historically these entities have been treated as separate pathophysiologic processes requiring different treatments: VTE, as the formation of fibrin-/coagulation-factor-derived thrombus in low flow vasculature, requiring anticoagulants; versus ATE, as largely platelet-derived thrombus in high flow vasculature, requiring antiplatelet agents. Observational studies have elucidated shared risk factors and co-morbidities predisposing individuals with VTE to ATE, and vice versa, and have bolstered the strategy of dual pathway inhibition (DPI) – the combination of low dose anticoagulants with antiplatelet agents – to reduce thrombotic outcomes on both sides of the vasculature. Randomized clinical trials have evaluated the efficacy and safety of such regimens - mostly rivaroxaban and aspirin - in high-risk groups of patients, including those with recent acute or chronic coronary syndrome, as well as those with peripheral artery disease with or without revascularization. Studies of extended VTE prophylaxis in acutely ill medical patients have also contributed to the evidence evaluating DPI. The totality of available data supports the concept that DPI can reduce major and fatal thromboembolic outcomes, including stroke, myocardial infarction, VTE, and cardiovascular death in key patient cohorts, with acceptable risk of bleeding. Further data are needed to refine which patients derive the best net clinical benefit from such an approach. At the same time, other novel agents such as contact pathway inhibitors that reduce thrombin generation without affecting hemostasis - and thus maximize safety - should be assessed in appropriate populations.

Desafios da profilaxia estendida do tromboembolismo venoso em pacientes clínicos e cirúrgicos

Patients hospitalized for acute medical and surgical illnesses are at risk of developing venous thromboembolism (VTE) during hospitalization and after discharge. Extended pharmacological prophylaxis beyond the hospital stay is recommended for patients undergoing surgeries at high risk for VTE and for selected groups of hospitalized medical patients. This practice involves several challenges, from identification of at-risk populations eligible for extended prophylaxis to choice of the most appropriate anticoagulant and definition of the ideal duration of use. This review will present the main VTE risk assessment models for hospitalized medical and surgical patients, the current recommendations for use of extended prophylaxis, and its limitations and benefits.

Challenges of extended venous thromboembolism prophylaxis in medical and surgical patients

Abstract Patients hospitalized for acute medical and surgical illnesses are at risk of developing venous thromboembolism (VTE) during hospitalization and after discharge. Extended pharmacological prophylaxis beyond the hospital stay is recommended for patients undergoing surgeries at high risk for VTE and for selected groups of hospitalized medical patients. This practice involves several challenges, from identification of at-risk populations eligible for extended prophylaxis to choice of the most appropriate anticoagulant and definition of the ideal duration of use. This review will present the main VTE risk assessment models for hospitalized medical and surgical patients, the current recommendations for use of extended prophylaxis, and its limitations and benefits.

Medically Ill hospitalized Patients for COVID-19 THrombosis Extended ProphyLaxis with rivaroxaban ThErapy: Rationale and Design of the MICHELLE Trial

BACKGROUND

The devastating Coronavirus disease (COVID-19) pandemic is associated with a high prothrombotic state. It is unclear if the coagulation abnormalities occur because of the direct effect of SARS-CoV-2 or indirectly by the cytokine storm and endothelial damage or by a combination of mechanisms. There is a clear indication of in-hospital pharmacological thromboprophylaxis for every patient with COVID-19 after bleed risk assessment. However, there is much debate regarding the best dosage regimen, and there is no consensus on the role of extended thromboprophylaxis.

DESIGN

This study aims to evaluate the safety and efficacy of rivaroxaban 10 mg once daily for 35 ± 4 days versus no intervention after hospital discharge in COVID-19 patients who were at increased risk for VTE and have received standard parenteral VTE prophylaxis during hospitalization. The composite efficacy endpoint is a combination of symptomatic VTE, VTE-related death, VTE detected by bilateral lower limbs venous duplex scan and computed tomography pulmonary angiogram on day 35 ± 4 posthospital discharge and symptomatic arterial thromboembolism (myocardial infarction, nonhemorrhagic stroke, major adverse limb events, and cardiovascular death) up to day 35 ± 4 posthospital discharge. The key safety outcome is the incidence of major bleeding according to ISTH criteria.

SUMMARY

The MICHELLE trial is expected to provide high-quality evidence around the role of extended thromboprophylaxis in COVID-19 and will help guide medical decisions in clinical practice.1.

Risk of Severe Bleeding With Extended Rivaroxaban to Prevent Venous Thromboembolism in Acute Medically Ill Patients With Bronchiectasis

Background: Bronchiectasis is a chronic inflammation of the bronchi with recurrent infections and hemoptysis. The MAGELLAN study compared oral rivaroxaban, 10 mg once daily (QD), for 35 ± 4 days with subcutaneous enoxaparin 40 mg QD for 10 ± 4 days followed by placebo for 25 ± 4 days to prevent venous thromboembolism in patients hospitalized with an acute medical illness. MAGELLAN included a subset of patients with bronchiectasis. In a post hoc analysis, we evaluated the incidence and severity of pulmonary bleeding in patients with bronchiectasis who were hospitalized for an acute medical illness. This analysis included MAGELLAN patients diagnosed with bronchiectasis at baseline. Patients were evaluated by treatment group for International Society on Thrombosis and Haemostasis major bleeding, non-major clinically relevant (NMCR) bleeding, and the composite of the 2 (ie, clinically relevant bleeding). Results: Medically ill patients with bronchiectasis were randomized to rivaroxaban (n = 60) or enoxaparin/placebo (n = 61). There were 2 fatal pulmonary bleeds and 1 fatal gastrointestinal bleed in the rivaroxaban arm and no fatal or major bleeding in the enoxaparin/placebo arm. The incidence of major bleeding was 5% in the rivaroxaban arm. One NMCR bleed occurred in the rivaroxaban arm and 2 NMCR bleeds occurred in the enoxaparin/placebo arm. The incidence of clinically relevant bleeding was 6.7% versus 3.3% in the rivaroxaban and enoxaparin/placebo groups, respectively (relative risk = 2.06 [95% confidence interval: 0.351-12.046]). Conclusion: In-patients hospitalized with bronchiectasis and an acute medical illness, clinically relevant bleeding, including fatal pulmonary hemorrhage, occurs more frequently with extended rivaroxaban thromboprophylaxis than with enoxaparin followed by placebo.

Peripheral artery disease, the 'lost syndrome' during lockdown for COVID-19: A report of three cases

The recent coronavirus disease 2019 (COVID-19) pandemic has significantly increased the burden placed on healthcare systems worldwide. This health emergency has led to changes being implemented in the organization of health institutions and has shifted the focus on pandemic management. This has led to marked changes being made in the treatment of patients without COVID-19, and has resulted in more difficult access to healthcare, with ensuing delays in diagnosis and treatment. Vascular diseases, including peripheral artery disease (PAD), require prompt treatment in the majority of cases in order to save affected limbs. Moreover, COVID-19 may result in acute arterial and venous complications, which need to be promptly recognized and treated. The present study describes three paradigmatic clinical cases of hospitalized patients, which are representative of the different forms of the 'lost syndrome' caused by either the direct effect of COVID-19 or by the effects of COVID-19 on the healthcare system and lifestyle factors. Prophylaxis against arterial and venous thrombotic events is crucial in patients with COVID-19, particularly those with a marked inflammatory state. On the other hand, the COVID-19 pandemic has diminished the access to healthcare system for patients with other chronic pathologies, with potential severe consequences for vulnerable patient groups, such as those with PAD and cardiovascular diseases. For these patients, the authors' experience over the last few months suggests that more suitable measures need to be adopted to avoid additional severe consequences on public health. In addition, it is necessary to identify pathways that will allow these patients to have rapid access to treatment with marked improvements in outcome.

Randomized clinical trial to evaluate a routine full anticoagulation Strategy in Patients with Coronavirus Infection (SARS-CoV2) admitted to hospital: Rationale and design of the ACTION (AntiCoagulaTlon cOroNavirus)-Coalition IV trial

BACKGROUND

Observational studies have suggested a higher risk of thrombotic events in patients with coronavirus disease 2019 (COVID-19). Moreover, elevated D-dimer levels have been identified as an important prognostic marker in COVID-19 directly associated with disease severity and progression. Prophylactic anticoagulation for hospitalized COVID-19 patients might not be enough to prevent thrombotic events; therefore, therapeutic anticoagulation regimens deserve clinical investigation.

DESIGN

ACTION is an academic-led, pragmatic, multicenter, open-label, randomized, phase IV clinical trial that aims to enroll around 600 patients at 40 sites participating in the Coalition COVID-19 Brazil initiative. Eligible patients with a confirmed diagnosis of COVID-19 with symptoms up to 14 days and elevated D-dimer levels will be randomized to a strategy of full-dose anticoagulation for 30 days with rivaroxaban 20 mg once daily (or full-dose heparin if oral administration is not feasible) vs standard of care with any approved venous thromboembolism prophylaxis regimen during hospitalization. A confirmation of COVID-19 was mandatory for study entry, based on specific tests used in clinical practice (RT-PCR, antigen test, IgM test) collected before randomization, regardless of in the outpatient setting or not. Randomization will be stratified by clinical stability at presentation. The primary outcome is a hierarchical analysis of mortality, length of hospital stay, or duration of oxygen therapy at the end of 30 days. Secondary outcomes include the World Health Organization's 8-point ordinal scale at 30 days and the following efficacy outcomes: incidence of venous thromboembolism , acute myocardial infarction, stroke, systemic embolism, major adverse limb events, duration of oxygen therapy, disease progression, and biomarkers. The primary safety outcomes are major or clinically relevant non-major bleeding according to the International Society on Thrombosis and Haemostasis criteria.

SUMMARY

The ACTION trial will evaluate whether in-hospital therapeutic anticoagulation with rivaroxaban for stable patients, or enoxaparin for unstable patients, followed by rivaroxaban through 30 days compared with standard prophylactic anticoagulation improves clinical outcomes in hospitalized patients with COVID-19 and elevated D-dimer levels.

Chronic intracardiac thrombus, a long-term complication of COVID-19: Case reports

Inflammation and thrombogenic effects of coronavirus disease 2019 (COVID‐19) can lead to cardiovascular complications in patients even after recovery from COVID‐19. Intracardiac thrombus is life‐threatening and can cause sudden death. Our study describes two patients who recovered from COVID‐19 and presented with chronic intracardiac thrombus.

Post-discharge thrombosis and bleeding in medical patients: A novel risk score derived from ubiquitous biomarkers

BACKGROUND

Some hospitalized medical patients experience venous thromboembolism (VTE) following discharge. Prophylaxis extended beyond hospital discharge (extended duration thromboprophylaxis [EDT]) may reduce this risk. However, EDT is costly and can cause bleeding, so selecting appropriate patients is essential. We formerly reported the performance of a mortality risk prediction score (Intermountain Risk Score [IMRS]) that was minimally predictive of 90-day hospital-associated venous thromboembolism (HA-VTE) and major bleeding (HA-MB). We used the components of the IMRS to calculate de novo risk scores to predict 90-day HA-VTE (HA-VTE IMRS) and major bleeding (HA-MB IMRS).

METHODS

From 45 669 medical patients we randomly assigned 30 445 to derive the HA-VTE IMRS and the HA-MB IMRS. Backward stepwise regression and bootstrapping identified predictor covariates from the blood count and basic chemistry. These candidate variables were split into quintiles, and the referent quintile was that with the lowest event rate for HA-VTE and HA-MB; respectively. A clinically relevant rate of HA-VTE and HA-MB was used to inform outcome rates. Performance was assessed in the derivation set of 15 224 patients.

RESULTS

The HA-VTE IMRS and HA-MB IMRS area under the receiver operating curve (AUC) in the derivation set were 0.646, and 0.691, respectively. In the validation set, the HA-VTE IMRS and HA-MB IMRS AUCs were 0.60 and 0.643.

CONCLUSIONS

Risk scores derived from components of routine labs ubiquitous in clinical care identify patients that are at risk for 90-day postdischarge HA-VTE and major bleeding. This may identify a subset of patients with high HA-VTE risk and low HA-MB risk who may benefit from EDT.

A clinical focus on the use of extended-duration thromboprophylaxis in medically ill patients

PURPOSE

This review describes and analyzes literature to provide recommendations for use of extended-duration thromboprophylaxis (EDT) in medically ill patients.

SUMMARY

Guidelines recommend pharmacologic thromboprophylaxis for patients at increased thrombosis risk during hospitalization and recommend against extending thromboprophylaxis beyond hospitalization. Despite these recommendations, observational data demonstrate that venous thromboembolism (VTE) risk persists following hospital discharge. A MEDLINE literature search was performed to identify original research evaluating the safety and efficacy of EDT. Eight meta-analyses and 5 randomized controlled trials-each varying in the agents studied (enoxaparin, rivaroxaban, apixaban, and betrixaban)-were selected for inclusion. Collectively, the evaluated data demonstrates that EDT reduces the incidence of VTE at the expense of increasing the risk of major bleeding and without providing mortality reduction. Variations in enrollment criteria, differences in EDT strategies, and uncertainty regarding proper patient selection limit the applicability of EDT in practice. Rivaroxaban and betrixaban gained Food and Drug Administration (FDA) approval on the basis of results of the APEX and MARINER trials and a post hoc analysis of the MAGELLEN trial results. Although a number of agents are FDA approved for use in EDT, clinicians must carefully weigh the risks vs benefits of EDT with these agents until studies demonstrate a more favorable risk-benefit profile.

CONCLUSION

Evidence to support EDT in medically ill patients is inconclusive and has highlighted the need for an individualized approach. The reviewed evidence supports guideline recommendations from both the American College of Chest Physicians and the American Society of Hematology that recommend against routine use of EDT in the majority of medically ill patients. Future studies are needed to optimize the risk-benefit profile of EDT and to ensure proper patient selection.

Efficacy, Safety, and Exposure of Apixaban in Patients with High Body Weight or Obesity and Venous Thromboembolism: Insights from AMPLIFY

Introduction

As a result of limited clinical data, guidelines do not recommend the use of non-vitamin K antagonist oral anticoagulants in patients who weigh > 120 kg or have a body mass index (BMI) > 40 kg/m².

Methods

This post hoc analysis of the AMPLIFY trial evaluated the efficacy (venous thromboembolism [VTE]/VTE-related death), safety (major and composite of major and clinically relevant non-major [CRNM] bleeding), and exposure of apixaban compared with enoxaparin followed by warfarin for the treatment of VTE by body weight (≤ 60, > 60 to < 100, ≥ 100 to < 120, ≥ 120 kg) and BMI (≤ 25, > 25 to 30, > 30 to 35, > 35 to 40, > 40 kg/m²).

Results

Among the AMPLIFY safety population, 5384 and 5359 patients had recorded body weight (range 28.9 to 222.0 kg; ≥ 120 kg, n = 290) and BMI (range 12.5–71.8 kg/m²; > 40 kg/m², n = 263), respectively. The rates of recurrent VTE/VTE-related death for apixaban versus enoxaparin/warfarin were similar across body weight subgroups: relative risks (RR; 95% confidence intervals [CI]) were 0.63 (0.23, 1.72), 0.99 (0.65, 1.50), 0.77 (0.34, 1.72), and 0.20 (0.02, 1.72) for the ≤ 60, > 60 to < 100, ≥ 100 to < 120, and ≥ 120 kg groups, respectively (P_interaction = 0.44). The rates of major bleeding were lower with apixaban versus enoxaparin/warfarin; RRs (95% CI) were 0.15 (0.02, 1.15), 0.41 (0.21, 0.77), not estimable, and 0.34 (0.04, 3.22), respectively (P_interaction = not estimable). The rates of major/CRNM bleeding were significantly lower for apixaban versus enoxaparin/warfarin; RRs (95% CI) were 0.46 (0.24, 0.89), 0.49 (0.38, 0.63), 0.30 (0.16, 0.58), and 0.28 (0.12, 0.66), respectively (P_interaction = 0.36). Similar trends were seen in the BMI subgroups. There was a modest, not clinically meaningful, decrease (< 30%) in the median predicted exposure with increasing body weight (n = 281).

Conclusions

The findings of this post hoc analysis support the use of apixaban in patients with body weight ≥ 120 kg or BMI > 40 kg/m².

Trial Registration Number

NCT00643201

Graphic Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-01716-8.

Current Opinion on the use of Direct Oral Anticoagulants for the Prophylaxis of Venous Thromboembolism among Medical Inpatients

Venous thromboembolism (VTE) is a known cause of morbidity and mortality, especially among acutely ill medical patients. Although VTE prophylaxis is part of post-discharge clinical care in surgical patients, there is controversy regarding its use in acutely ill medical patients and the current guideline statements suggest against its routine use. Recent clinical trials (APEX, MAGELLAN and MARINER) compared the safety and efficacy of direct oral anticoagulants (including betrixaban and rivaroxaban) with the standard of the care, enoxaparin, to identify the risk–benefit tradeoff. In this review, we summarized the key findings from these trials and substudies and recent updates in society guidelines regarding VTE prevention. In addition, we discussed the potential barriers, cost-effectiveness, and COVID-19 with respect to the implementation of extended-duration or post-discharge usage of direct oral anticoagulants.

Thromboembolic Complications of SARS-CoV-2 and Metabolic Derangements: Suggestions from Clinical Practice Evidence to Causative Agents

Severe Acute Respiratory Syndrome (SARS) Coronavirus (CoV)-2 is a recently identified positive sense single-strand RNA (ssRNA) β-coronavirus. The viral spike proteins infect human hosts by binding to the cellular receptor angiotensin-converting enzyme 2 (ACE2). The infection causes a systemic illness involving cell metabolism. This widespread involvement is implicated in the pathophysiology of the illness which ranges from mild to severe, requiring multi organ support, ranging from oxygen supplementation to full cardiovascular and respiratory support. Patients with multiple co-existing comorbidities are also at a higher risk. The aim of this review is to explore the exact mechanisms by which COVID-19 affects patients systemically with a primary focus on the bleeding and thrombotic complications linked with the disease. Issues surrounding the thrombotic complications following administration of the ChAdOx1 nCoV-19 (Astra-Zeneca-Oxford) vaccine have also been illustrated. Risk stratification and treatment options in these patients should be tailored according to clinical severity with input from a multidisciplinary team.

Rationale and design for the study of rivaroxaban to reduce thrombotic events, hospitalization and death in outpatients with COVID-19: The PREVENT-HD study

BACKGROUND

COVID-19 is associated with both venous and arterial thrombotic complications. While prophylactic anticoagulation is now widely recommended for hospitalized patients with COVID-19, the effectiveness and safety of thromboprophylaxis in outpatients with COVID-19 has not been established.

STUDY DESIGN

PREVENT-HD is a double-blind, placebo-controlled, pragmatic, event-driven phase 3 trial to evaluate the efficacy and safety of rivaroxaban in symptomatic outpatients with laboratory-confirmed COVID-19 at risk for thrombotic events, hospitalization, and death. Several challenges posed by the pandemic have necessitated innovative approaches to clinical trial design, start-up, and conduct. Participants are randomized in a 1:1 ratio, stratified by time from COVID-19 confirmation, to either rivaroxaban 10 mg once daily or placebo for 35 days. The primary efficacy end point is a composite of symptomatic venous thromboembolism, myocardial infarction, ischemic stroke, acute limb ischemia, non-central nervous system systemic embolization, all-cause hospitalization, and all-cause mortality. The primary safety end point is fatal and critical site bleeding according to the International Society on Thrombosis and Haemostasis definition. Enrollment began in August 2020 and is expected to enroll approximately 4,000 participants to yield the required number of end point events.

CONCLUSIONS

PREVENT-HD is a pragmatic trial evaluating the efficacy and safety of the direct oral anticoagulant rivaroxaban in the outpatient setting to reduce major venous and arterial thrombotic events, hospitalization, and mortality associated with COVID-19.

Prognostic Value of Venous Thromboembolism Risk Assessment Models in Patients with Severe COVID-19

Introduction  Severe novel corona virus disease 2019 (COVID-19) causes dysregulation of the coagulation system with arterial and venous thromboembolism (VTE). We hypothesize that validated VTE risk scores would have prognostic ability in this population. Methods  Retrospective observational cohort with severe COVID-19 performed in NorthShore University Health System. Patients were >18 years of age and met criteria for inpatient or intensive care unit (ICU) care. The International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) and Caprini scores were calculated and patients were stratified. Results  This study includes 184 patients, mostly men (63.6%), Caucasian (54.3%), 63 years old (interquartile range [IQR]: 24-101), and 57.1% of them required ICU care. Twenty-seven (14.7%) thrombotic events occurred: 12 (6.5%) cases of disseminated intravascular coagulation (DIC), 9 (4.9%) of pulmonary embolism, 5 (2.7%) of deep vein thrombosis, and 1 (0.5%) stroke. Among them, 86 patients (46.7%) died, 95 (51.6%) were discharged, and 3 (1.6%) were still hospitalized. "Moderate risk for VTE" and "High risk for VTE" by IMPROVE score had significant mortality association: (hazard ratio [HR]: 5.68; 95% confidence interval [CI]: 2.93-11.03; p  < 0.001) and (HR = 6.22; 95% CI: 3.04-12.71; p  < 0.001), respectively, with 87% sensitivity and 63% specificity (area under the curve [AUC] = 0.752, p  < 0.001). "High Risk for VTE" by Caprini score had significant mortality association (HR = 17.6; 95% CI: 5.56-55.96; p  < 0.001) with 96% sensitivity and 55% specificity (AUC = 0.843, p  < 0.001). Both scores were associated with thrombotic events when classified as "High risk for VTE" by IMPROVE (HR = 6.50; 95% CI: 2.72-15.53; p  < 0.001) and Caprini scores (HR = 11.507; 95% CI: 2.697-49.104; p  = 0.001). Conclusion  The IMPROVE and Caprini risk scores were independent predictors of mortality and thrombotic events in severe COVID-19. With larger validation, this can be useful prognostic information.

Extended Thromboprophylaxis With Betrixaban or Rivaroxaban for Acutely Ill Hospitalized Medical Patients: Meta-Analysis of Prespecified Subgroups

BACKGROUND

Betrixaban and rivaroxaban are the direct anticoagulants approved in the United States for extended venous thromboembolism (VTE) prophylaxis among acutely ill medical patients. The efficacy and safety in specific subgroups remain unclear.

METHODS

A meta-analysis of 3 randomized trials involving extended thromboprophylaxis with betrixaban or rivaroxaban versus enoxaparin for medically ill patients was performed to compare VTE (composite of asymptomatic proximal and symptomatic deep vein thrombosis, pulmonary embolism, or VTE-related death) and major bleeding in subgroups by baseline D-dimer, age, sex, and major medical illness on hospitalization. Risk difference (RD) was computed with the Mantel-Haenszel method by fitting a fixed-effect model. Heterogeneity of treatment effect across subgroups was examined using the nominal thresholds of P < 0.05 and I2 > 75%.

RESULTS

Compared with enoxaparin, extended betrixaban or rivaroxaban reduced VTE (RD = -1.51% [95% CI, -2.32% to -0.69%]; P = 0.0003) without excess major bleeding (RD = 0.12% [-0.05% to 0.29%]; P = 0.16). A significant effect modification was observed in the subgroups by D-dimer (P = 0.004) and age (P = 0.04). Patients with D-dimer >2× upper limit of normal (ULN) experienced a greater VTE reduction (RD = -2.39% [-3.57% to -1.21%]; P < 0.0001) than those with ≤2×ULN (RD = -0.26% [-1.08% to 0.56%]; P = 0.53). Similarly, patients aged ≥75 years had a greater VTE reduction (RD = -2.29% [-3.49% to -1.09%]; P = 0.0002) than those aged <75 years (RD = -0.63% [-1.70% to 0.44%]; P = 0.25). Treatment effect was consistent across the remaining subgroups.

CONCLUSIONS

A more favorable efficacy and comparable safety outcome associated with extended betrixaban or rivaroxaban were observed among medical inpatients with D-dimer >2×ULN or aged ≥75 years. D-dimer and advanced age may assist in decision-making on pharmacological thromboprophylaxis for hospitalized medical patients.

Post-hospital discharge venous thromboembolism prophylaxis in medically ill patients

There is a widely expressed concern about an unmet need for post hospitalization venous thromboembolism (VTE) prophylaxis in medically ill patients, however, physicians and hospitals have been slow to implement this measure. Recommendations against extended VTE prophylaxis in medical patients from the American Society of Hematology (ASH) in 2018 and the withholding of approval of betrixiban by the European Medicines Agency also in 2018 may have been influential in this regard. Furthermore, rivaroxaban the other drug approved for this indication in the U.S has not yet been approved in Europe. In addition, hospital administrators, those monitoring expenses in the U.S, have been reluctant to support a treatment which will mostly involve outpatients. Internal medicine physicians, hospitalists and nursing home physicians have not shared the fervor for post hospital VTE prophylaxis, whether with anticoagulants or aspirin, that their orthopedic surgery colleagues have, particularly in hip and knee arthroplasty. This is despite an increased risk of post hospital discharge thrombosis in both groups of patients. Enter hospitalized patients with COVID-19, a potentially severe medical illness with high hospitalization related thrombosis risk, and questions arise as to whether these medical patients, who are clearly more hypercoagulable during hospitalization than those in previous studies, should warrant post hospital discharge prophylaxis.

Prevention of Venous Thromboembolism in Acutely Ill Medical Patients: A New Era

Venous thromboembolism (VTE) is the leading preventable cause of death in hospitalized patients and data consistently show that acutely ill medical patients remain at increased risk for VTE-related morbidity and mortality in the post-hospital discharge period. Prescribing extended thromboprophylaxis for up to 45 days following an acute hospitalization in key patient subgroups that include more than one-quarter of hospitalized medically-ill patients represents a paradigm shift in the way hospital-based physicians think about VTE prevention. Advances in the field of primary thromboprophylaxis in acutely-ill medical patients using validated VTE and bleeding risk assessment models have established key patient subgroups at high risk of VTE and low risk of bleeding that may benefit from both in-hospital and extended thromboprophylaxis. The direct oral anticoagulants betrixaban and rivaroxaban are now U.S. Food and Drug Administration-approved for in-hospital and extended thromboprophylaxis in medically ill patients and provide net clinical benefit in these key subgroups. Coronavirus disease-2019 may predispose patients to VTE due to excessive inflammation, platelet activation, endothelial dysfunction, and hemostasis. The optimum preventive strategy for these patients requires further investigation. This article aims to review the latest concepts in predicting and preventing VTE and discuss the new era of extended thromboprophylaxis in hospitalized medically ill patients.

Post-Discharge Prophylaxis With Rivaroxaban Reduces Fatal and Major Thromboembolic Events in Medically Ill Patients

Background

Hospitalized acutely ill medical patients are at risk for fatal and major thromboembolic events. Whether use of extended-duration primary thromboprophylaxis can prevent such events is unknown.

Objectives

The purpose of this study was to evaluate whether extended-duration rivaroxaban reduces the risk of venous and arterial fatal and major thromboembolic events without significantly increasing major bleeding in acutely ill medical patients after discharge.

Methods

MARINER (A Study of Rivaroxaban [JNJ-39039039] on the Venous Thromboembolic Risk in Post-Hospital Discharge Patients) studied acutely ill medical patients with additional risk factors for venous thromboembolism (VTE). Medically ill patients with a baseline creatinine clearance ≥50 ml/min were randomized in a double-blind fashion to rivaroxaban 10 mg or placebo daily at hospital discharge for 45 days. Exploratory efficacy analyses were performed with the intent-to-treat population including all data through day 45. Time-to-event curves were calculated using the Kaplan-Meier method. A blinded independent committee adjudicated all clinical events.

Results

In total, 4,909 patients were assigned to rivaroxaban and 4,913 patients to placebo. The mean age was 67.8 years, 55.5% were men, mean baseline creatinine clearance was 87.8 ml/min, and mean duration of hospitalization was 6.7 days. The pre-specified composite efficacy endpoint (symptomatic VTE, myocardial infarction, nonhemorrhagic stroke, and cardiovascular death) occurred in 1.28% and 1.77% of patients in the rivaroxaban and placebo groups, respectively (hazard ratio: 0.72; 95% confidence interval: 0.52 to 1.00; p = 0.049), whereas major bleeding occurred in 0.27% and 0.18% of patients in the rivaroxaban and placebo groups, respectively (hazard ratio: 1.44; 95% confidence interval: 0.62 to 3.37; p = 0.398).

Conclusions

Extended-duration rivaroxaban in hospitalized medically ill patients resulted in a 28% reduction in fatal and major thromboembolic events without a significant increase in major bleeding. (A Study of Rivaroxaban [JNJ-39039039] on the Venous Thromboembolic Risk in Post-Hospital Discharge Patients [MARINER]; NCT02111564)

Identification and Outcomes of Hospitalized Medically Ill Patients Who Are Candidates for Extended Duration Thromboprophylaxis

Background  Extended duration thromboprophylaxis (ET) for approximately 30 days can effectively and safely reduce venous thromboembolism (VTE) risk in appropriately selected medically ill patients. We sought to estimate the proportion of hospitalized medically ill patients potentially qualifying for ET and assess their post-discharge clinical and economic outcomes using a large claims database.

Methods  Using MarketScan claims from January 2012 to September 2018, we identified medically ill patients hospitalized with a primary diagnosis of heart failure, respiratory insufficiency, ischemic stroke, infection, or inflammatory disease and ≥1-additional risk factor for VTE. Patients < 40 years old, a length-of-stay < 3 or >30 days, receiving oral anticoagulation prior to index hospitalization or having an indication for full-dose anticoagulation were excluded, as were patients deemed high-risk for bleeding due to active, in-hospital treated cancer, gastroduodenal ulcer or bleeding within the prior 3 months, bronchiectasis, pulmonary cavitation or hemorrhage, or dual antiplatelet therapy use.

Results  We identified 2,782,988 patients ≥40 years of age and admitted for a high-risk medical illness. Of these, 724,531 patients (26.0%) were identified as ET candidates. Patients' VTE risk appeared highest in the first 30 days post-discharge (1,532/724,531, 0.2%). Adjusted post-index hospitalization costs (2018 US$) for patients with a VTE within 30 days were higher than those without VTE (Δ = $32,623 at 30 days, Δ = $43,325 at 90 days, Δ = $53,668 at 365 days; p  < 0.001 for all).

Conclusion  Post-discharge VTE in high-risk patients with medical illness is associated with substantially increased costs.

Coagulopathy, Venous Thromboembolism, and Anticoagulation in Patients with COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has led to a worldwide pandemic, and patients with the infection are referred to as having COVID‐19. Although COVID‐19 is commonly considered a respiratory disease, there is clearly a thrombotic potential that was not expected. The pathophysiology of the disease and subsequent coagulopathy produce an inflammatory, hypercoagulable, and hypofibrinolytic state. Several observational studies have demonstrated surprisingly high rates of venous thromboembolism (VTE) in both general ward and intensive care patients with COVID‐19. Many of these observational studies demonstrate high rates of VTE despite patients being on standard, or even higher intensity, pharmacologic VTE prophylaxis. Fibrinolytic therapy has also been used in patients with acute respiratory distress syndrome. Unfortunately, high quality randomized controlled trials are lacking. A literature search was performed to provide the most up‐to‐date information on the pathophysiology, coagulopathy, risk of VTE, and prevention and treatment of VTE in patients with COVID‐19. These topics are reviewed in detail, along with practical issues of anticoagulant selection and duration. Although many international organizations have produced guidelines or consensus statements, they do not all cover the same issues regarding anticoagulant therapy for patients with COVID‐19, and they do not all agree. These statements and the most recent literature are combined into a list of clinical considerations that clinicians can use for the prevention and treatment of VTE in patients with COVID‐19.

Coronavirus Historical Perspective, Disease Mechanisms, and Clinical Outcomes: JACC Focus Seminar

The emergence of a new coronavirus disease (coronavirus disease 2019 [COVID-19]) has raised global concerns regarding the health and safety of a vulnerable population. Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) incites a profound inflammatory response leading to tissue injury and organ failure. COVID-19 is characterized by the bidirectional relationship between inflammation and thrombosis. The clinical syndrome is propelled by inflammation producing acute lung injury, large-vessel thrombosis, and in situ microthrombi that may contribute to organ failure. Myocardial injury is common, but true myocarditis is rare. Elderly patients, those with established cardiovascular disease, and mechanically ventilated patients face the highest mortality risk. Therapies for COVID-19 are evolving. The antiviral drug remdesivir, dexamethasone, transfusion of convalescent plasma, and use of antithrombotic therapy are promising. Most require additional prospective studies. Although most patients recover, those who survive severe illness may experience persistent physical and psychological disabilities.

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Severe acute respiratory syndrome coronavirus 2 infection (COVID-19) is a global pandemic affecting millions of people worldwide.

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Clinical sequelae result largely from an intense inflammatory response triggering large-vessel and microvascular thrombosis.

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No therapy has been universally effective for COVID-19, but systemic anticoagulation, remdesivir, and corticosteroids hold promise.

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Long-term sequelae of COVID-19 are variable and incompletely defined, but physical and psychological disabilities can persist.

Venous thromboembolism in COVID-19 patients

COVID-19 is a potentially serious respiratory disease caused by the SARS-CoV-2 virus that involves an increased risk of venous thromboembolism (VTE). Its pathophysiology is apparently related to an exacerbated inflammatory process and coagulopathy, verified by an increase in D-dimer, fibrinogen, and fibrin degradation products. Occurrence must be monitored, prevented, and treated according to existing recommendations and guidelines. The increased risk of thrombosis, and the association between this phenomenon and the most severe forms of the disease and death have prompted some groups to propose a more aggressive prophylactic and therapeutic approach. However, the risk-benefit profile of this type of conduct has not been defined and cases must be assessed individually, with a multidisciplinary approach. In this study, we review the main studies and evidence available to date on diagnosis, prophylaxis, and treatment of venous thromboembolism in COVID-19 patients.

COVID-19 Related Arterial Coagulopathy

Coronavirus disease of 2019 (COVID-19) is a disease caused by the novel coronavirus SARS-CoV-2, which is characterized by a multitude of clinical abnormalities, including hypercoagulability. Although thrombosis is commonly observed in sepsis, the hypercoagulable state associated with COVID-19 is much more dramatic and may not be related to either the severity of the disease or the D-dimer levels. It may be due to a prothrombotic state induced by the disease itself. We report three cases of arterial thrombosis with a significant clot burden requiring urgent medical and surgical intervention. It is now a common practice to initiate anticoagulation for deep venous thrombosis (DVT) prophylaxis based on the D-dimer level in hospitalized patients with COVID-19. However, in our clinical experience, D-dimer levels did not correlate well with the clot burden or the risk for future thrombosis. 

Pharmacological Agents Targeting Thromboinflammation in COVID-19: Review and Implications for Future Research

Coronavirus disease 2019 (COVID-19), currently a worldwide pandemic, is a viral illness caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The suspected contribution of thrombotic events to morbidity and mortality in COVID-19 patients has prompted a search for novel potential options for preventing COVID-19-associated thrombotic disease. In this article by the Global COVID-19 Thrombosis Collaborative Group, we describe novel dosing approaches for commonly used antithrombotic agents (especially heparin-based regimens) and the potential use of less widely used antithrombotic drugs in the absence of confirmed thrombosis. Although these therapies may have direct antithrombotic effects, other mechanisms of action, including anti-inflammatory or antiviral effects, have been postulated. Based on survey results from this group of authors, we suggest research priorities for specific agents and subgroups of patients with COVID-19. Further, we review other agents, including immunomodulators, that may have antithrombotic properties. It is our hope that the present document will encourage and stimulate future prospective studies and randomized trials to study the safety, efficacy, and optimal use of these agents for prevention or management of thrombosis in COVID-19.

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

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

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

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

New Paradigms of Extended Thromboprophylaxis in Medically Ill Patients

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

Modified IMPROVE VTE Risk Score and Elevated D-Dimer Identify a High Venous Thromboembolism Risk in Acutely Ill Medical Population for Extended Thromboprophylaxis

An individualized approach to identify acutely ill medical patients at increased risk of venous thromboembolism (VTE) and a low risk of bleeding to optimize the benefit and risk of extended thromboprophylaxis (ET) is needed. The International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) VTE risk score has undergone extensive external validation in medically ill patients for in-hospital use and a modified model was used in the MARINER trial of ET also incorporating an elevated D-dimer. The MAGELLAN study demonstrated efficacy with rivaroxaban but had excess bleeding. This retrospective analysis investigated whether the modified IMPROVE VTE model with an elevated D-dimer could identify a high VTE risk subgroup of patients for ET from a subpopulation of the MAGELLAN study, which was previously identified as having a lower risk of bleeding. We incorporated the modified IMPROVE VTE score using a cutoff score of 4 or more or 2 and 3 with an elevated D-dimer (>2 times the upper limit of normal) to the MAGELLAN subpopulation. In total, 56% of the patients met the high-risk criteria. In the placebo group, the total VTE event rate at Day 35 was 7.94% in the high-risk group and 2.83% for patients in the lower-risk group. A reduction in VTE was observed with rivaroxaban in the high-risk group (relative risk [RR]: 0.68, 95% confidence interval [CI]: 0.51-0.91, p  = 0.008) and in the lower-risk group (RR: 0.69, 95% CI: 0.40 -1.20, p  = 0.187). The modified IMPROVE VTE score with an elevated D-dimer identified a nearly threefold higher VTE risk subpopulation of patients where a significant benefit exists for ET using rivaroxaban.