Randomized trials of therapeutic heparin for COVID-19: A meta-analysis

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.

The 2023 Belgian clinical guidance on anticoagulation management in hospitalized and ambulatory COVID-19 patients

COVID-19 is associated with an increased risk for thrombotic complications. The trials investigating the optimal thromboprophylactic dose are performed in challenging times and seemingly produce conflicting evidence. The burdensome circumstances, divergent endpoints, and different analytical approaches hamper comparison and extrapolation of available evidence. Most importantly, clinicians should provide thromboprophylaxis in hospitalized COVID-19 patients while (re)assessing bleeding and thrombotic risk frequently. The COVID-19 Thromboprophylaxis Working Group of the BSTH updated its guidance document. It aims to summarize the available evidence critically and to guide clinicians in providing the best possible thromboprophylaxis.

Estrogen-based hormonal therapy and the risk of thrombosis in COVID-19 patients

OBJECTIVE

Estrogen-containing contraceptives and hormone replacement therapy are used commonly, however, the risks of venous and arterial thrombosis imparted by such medications during COVID-19 infection or other similar viral infections remain undescribed.

METHODS

To assess the risk of venous and arterial thrombosis in patients receiving oral estrogen-containing therapy (ECT) with COVID-19 as compared to those receiving non-estrogen-based hormonal therapy, we conducted a multicenter cohort study of 991 patients with confirmed COVID-19 infection, 466 receiving estrogen-containing hormonal therapy, and 525 receiving progestin-only or topical therapy.

RESULTS

The use of estrogen-containing therapy was found to significantly increase the risk of venous thromboembolism (VTE) following COVID-19 diagnosis after controlling for age (HR 5.46 [95% CI 1.12-26.7, p = .036]). This risk was highest in patients over age 50, with 8.6% of patients receiving estrogen-containing therapy diagnosed with VTE compared to 0.9% of those receiving non-estrogen-based therapies (p = .026). The risk of arterial thrombosis was not significantly associated with oral estrogen use.

CONCLUSIONS

These results suggest that estrogen-containing therapy is associated with a significantly increased risk of VTE in COVID-19 patients, especially in older individuals. These findings may guide provider counseling and management of patients with COVID-19 on estrogen-containing therapy.

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

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

Enoxaparin for symptomatic COVID-19 managed in the ambulatory setting: An individual patient level analysis of the OVID and ETHIC trials

BACKGROUND

Antithrombotic treatment may improve the disease course in non-critically ill, symptomatic COVID-19 outpatients.

METHODS

We performed an individual patient-level analysis of the OVID and ETHIC randomized controlled trials, which compared enoxaparin thromboprophylaxis for either 14 (OVID) or 21 days (ETHIC) vs. no thromboprophylaxis for outpatients with symptomatic COVID-19 and at least one additional risk factor. The primary efficacy outcome included all-cause hospitalization and all-cause death within 30 days from randomization. Both studies were prematurely stopped for futility. Secondary efficacy outcomes were major symptomatic venous thromboembolic events, arterial cardiovascular events, or their composite occurring within 30 days from randomization. The same outcomes were assessed over a 90-day follow-up. The primary safety outcome was major bleeding (ISTH criteria).

RESULTS

A total of 691 patients were randomized: 339 to receive enoxaparin and 352 to the control group. Over 30-day follow-up, the primary efficacy outcome occurred in 6.0 % of patients in the enoxaparin group vs. 5.8 % of controls for a risk ratio (RR) of 1.05 (95%CI 0.57-1.92). The incidence of major symptomatic venous thromboembolic events and arterial cardiovascular events was 0.9 % vs. 1.8 %, respectively (RR 0.52; 95%CI 0.13-2.06). Most cardiovascular thromboembolic events were represented by symptomatic venous thromboembolic events, occurring in 0.6 % vs. 1.5 % of patients, respectively. A similar distribution of outcomes between the treatment groups was observed over 90 days. No major bleeding occurred in the enoxaparin group vs. one (0.3 %) in the control group.

CONCLUSIONS

We found no evidence for the clinical benefit of early administration of enoxaparin thromboprophylaxis in outpatients with symptomatic COVID-19. These results should be interpreted taking into consideration the relatively low occurrence of events.

Therapeutic-dose anticoagulation or thromboprophylaxis with low-molecular-weight heparin for moderate Covid-19: meta-analysis of randomized controlled trials

BACKGROUND

We carried out a meta-analysis since there is not enough evidence to recommend for or against therapeutic-dose anticoagulation compared with thromboprophylaxis in noncritically ill patients hospitalized with Covid-19.

METHODS

We performed a systematic literature search using PubMed, Embase, Cochrane Library, and MedRxiv for randomized trials that included therapeutic-dose with low-molecular-weight heparin (LMW) or thromboprophylaxis with LMW heparin in noncritically ill patients admitted to the hospital with Covid-19. We identified five open-label studies for analysis with a total of 3220 patients. Two independent researchers selected, assessed, and extracted the data in duplicate. The outcomes evaluated were all-cause mortality, progression to invasive mechanical ventilation, incidence of venous thromboembolism, and major bleeding. The studies did not show risk for selection, detection, attrition, or reporting bias.

RESULTS

Therapeutic-dose anticoagulation with LMW heparin compared with thromboprophylaxis with LMW heparin had no significant effect of all-cause death (risk ratio [RR] 0.85; 95% confidence interval [CI] 0.67-1.07; P = 0.16; I2 = 48%), or progression to invasive mechanical ventilation (RR 0.89; CI 0.73-1.08; P = 0.24; I2: 0%). Therapeutic-dose anticoagulation significantly reduced the risk of venous thromboembolic disease (RR 0.42; 95% CI 0.28-0.62; P = 0.0001; I2 = 0%) [Number needed to treat = 37]. Major bleeding occurred in 1.79% of the patients receiving therapeutic-dose anticoagulation and in 0.97% of those receiving thromboprophylaxis [Number needed to harm 125].

CONCLUSION

Therapeutic-dose anticoagulation in noncritically ill patients with Covid-19 could be indicated for patients at high risk of venous thromboembolic disease and low risk of bleeding.

Cerebrovascular Disease in COVID-19

Not in the history of transmissible illnesses has there been an infection as strongly associated with acute cerebrovascular disease as the novel human coronavirus SARS-CoV-2. While the risk of stroke has known associations with other viral infections, such as influenza and human immunodeficiency virus, the risk of ischemic and hemorrhagic stroke related to SARS-CoV-2 is unprecedented. Furthermore, the coronavirus disease 2019 (COVID-19) pandemic has so profoundly impacted psychosocial behaviors and modern medical care that we have witnessed shifts in epidemiology and have adapted our treatment practices to reduce transmission, address delayed diagnoses, and mitigate gaps in healthcare. In this narrative review, we summarize the history and impact of the COVID-19 pandemic on cerebrovascular disease, and lessons learned regarding the management of patients as we endure this period of human history.

Optimal dosing of heparin for prophylactic anticoagulation in critically ill COVID-19 patients a systematic review and meta-analysis of randomized controlled trials

PURPOSE

The optimal amount of anticoagulation for critically ill COVID-19 patients is controversial. Therefore, we aimed to evaluate the efficacy and safety of escalated doses of anticoagulation in critically ill patients with severe COVID-19.

MATERIALS AND METHODS

We conducted a systematic search of three major databases, including PubMed, Cochrane Library, and Embase, from inception to May 2022. Randomized controlled trials (RCTs) were included comparing therapeutic or intermediate doses to standard prophylactic doses of anticoagulants in critically ill COVID-19 patients, with heparins as the only anticoagulation therapy considered.

RESULTS

Out of the six RCTs, 2130 patients were administered escalated dose anticoagulation (50.2%) and standard thromboprophylaxis therapy (49.8%). The escalated dose showed no significant impact on mortality (RR, 1.01; 95% CI, 0.90-1.13). Although there was no significant difference in DVT (RR, 0.81; 95% CI, 0.61-1.08), the risk of PE was significantly reduced in patients receiving escalated dose anticoagulation (RR, 0.35; 95% CI, 0.21-0.60), with an increased risk of bleeding events (RR, 1.65; 95% CI, 1.08-2.53).

CONCLUSION

This systematic review and meta-analysis fail to support escalated anticoagulation doses to reduce mortality in critically ill COVID-19 patients. However, higher doses of anticoagulants appear to reduce thrombotic events while increasing the risk of bleeding effectively.

Antithrombotic therapy in the management of hospitalised patients with COVID-19

Hospitalised patients with coronavirus disease 2019 (COVID-19) are at a significantly higher risk of having thromboembolic events while in hospital and in the immediate post-hospital discharge period. Based on early data from observational studies, multiple high quality randomised controlled trials have been conducted worldwide to evaluate optimal thromboprophylaxis regimens to reduce thromboembolism and other COVID-19-related adverse outcomes in hospitalised patients. The International Society on Thrombosis and Haemostasis has published evidence-based guideline recommendations using established methodology for the management of antithrombotic therapy of COVID-19 patients, both in-hospital and in the immediate post-hospital discharge period. A good clinical practice statement supplemented these guidelines based on topics for which there was no or limited high-quality evidence. This review summarises the main recommendations of these documents to serve as a quick access tool for hospital doctors to use in their everyday practice when treating COVID-19 patients.

Effects of Standard-Dose Prophylactic, High-Dose Prophylactic, and Therapeutic Anticoagulation in Patients With Hypoxemic COVID-19 Pneumonia: The ANTICOVID Randomized Clinical Trial

Importance

Given the high risk of thrombosis and anticoagulation-related bleeding in patients with hypoxemic COVID-19 pneumonia, identifying the lowest effective dose of anticoagulation therapy for these patients is imperative.

Objectives

To determine whether therapeutic anticoagulation (TA) or high-dose prophylactic anticoagulation (HD-PA) decreases mortality and/or disease duration compared with standard-dose prophylactic anticoagulation (SD-PA), and whether TA outperforms HD-PA; and to compare the net clinical outcomes among the 3 strategies.

Design, Settings, and Participants

The ANTICOVID randomized clinical open-label trial included patients with hypoxemic COVID-19 pneumonia requiring supplemental oxygen and having no initial thrombosis on chest computer tomography with pulmonary angiogram at 23 health centers in France from April 14 to December 13, 2021. Of 339 patients randomized, 334 were included in the primary analysis-114 patients in the SD-PA group, 110 in the HD-PA, and 110 in the TA. At randomization, 90% of the patients were in the intensive care unit. Data analyses were performed from April 13, 2022, to January 3, 2023.

Interventions

Patients were randomly assigned (1:1:1) to receive either SD-PA, HD-PA, or TA with low-molecular-weight or unfractionated heparin for 14 days.

Main Outcomes and Measures

A hierarchical criterion of all-cause mortality followed by time to clinical improvement at day 28. Main secondary outcome was net clinical outcome at day 28 (composite of thrombosis, major bleeding, and all-cause death).

Results

Among the study population of 334 individuals (mean [SD] age, 58.3 [13.0] years; 226 [67.7%] men and 108 [32.3%] women), use of HD-PA and SD-PA had similar probabilities of favorable outcome (47.3% [95% CI, 39.9% to 54.8%] vs 52.7% [95% CI, 45.2% to 60.1%]; P = .48), as did TA compared with SD-PA (50.9% [95% CI, 43.4% to 58.3%] vs 49.1% [95% CI, 41.7% to 56.6%]; P = .82) and TA compared with HD-PA (53.5% [95% CI 45.8% to 60.9%] vs 46.5% [95% CI, 39.1% to 54.2%]; P = .37). Net clinical outcome was met in 29.8% of patients receiving SD-PA (20.2% thrombosis, 2.6% bleeding, 14.0% death), 16.4% receiving HD-PA (5.5% thrombosis, 3.6% bleeding, 11.8% death), and 20.0% receiving TA (5.5% thrombosis, 3.6% bleeding, 12.7% death). Moreover, HD-PA and TA use significantly reduced thrombosis compared with SD-PA (absolute difference, -14.7 [95% CI -6.2 to -23.2] and -14.7 [95% CI -6.2 to -23.2], respectively). Use of HD-PA significantly reduced net clinical outcome compared with SD-PA (absolute difference, -13.5; 95% CI -2.6 to -24.3).

Conclusions and Relevance

This randomized clinical trial found that compared with SD-PA, neither HD-PA nor TA use improved the primary hierarchical outcome of all-cause mortality or time to clinical improvement in patients with hypoxemic COVID-19 pneumonia; however, HD-PA resulted in significantly better net clinical outcome by decreasing the risk of de novo thrombosis.

Trial Registration

ClinicalTrials.gov Identifier: NCT04808882.

In silico analysis of dietary polyphenols and their gut microbial metabolites suggest inhibition of SARS-CoV-2 infection, replication, and host inflammatory mediators

The outcome of SARS-CoV-2 infection ranges from asymptomatic to severe COVID-19 and death resulting from an exaggerated immune response termed cytokine storm. Epidemiological data have associated consumption of a high-quality plant-based diet with decreased incidence and severity of COVID-19. Dietary polyphenols and their microbial metabolites (MMs) have anti-viral and anti-inflammatory activities. Autodock Vina and Yasara were used in molecular docking and dynamics studies to investigate potential interactions of 7 parent polyphenols (PPs) and 11 MMs with the α- and Omicron variants of the SARS-CoV-2 spike glycoprotein (SGP), papain-like pro-tease (PLpro) and 3 chymotrypsin-like protease (3CLpro), as well as host inflammatory mediators including complement component 5a (C5a), C5a receptor (C5aR), and C-C chemokine receptor type 5 (CCR5). PPs and MMs interacted to varying degrees with residues on target viral and host inflammatory proteins showing potential as competitive inhibitors. Based on these in silico findings, PPs and MMs may inhibit SARS-CoV-2 infection, replication, and/or modulate host immunity in the gut or periphery. Such inhibition may explain why people that consume a high-quality plant-based diet have less incidence and severity of COVID-19.Communicated by Ramaswamy H. Sarma.

The Effect of Heparin Full-Dose Anticoagulation on Survival of Hospitalized, Non-critically Ill COVID-19 Patients: A Meta-analysis of High Quality Studies

BACKGROUND

International COVID-19 guidelines recommend thromboprophylaxis for non-critically ill inpatients to prevent thrombotic complications. It is still debated whether full-dose thromboprophylaxis reduces all-cause mortality. The main aim of this updated systematic review and meta-analysis is to evaluate the effect of full-dose heparin-based thromboprophylaxis on survival in hospitalized non-critically ill COVID-19 patients.

METHODS

A systematic review was performed across Pubmed/Medline, EMBASE, Cochrane Central Register of clinical trials, Clinicaltrials.gov, and medRxiv.org from inception to November 2022. We conducted a meta-analysis of randomized clinical trials (RCTs) comparing full-dose heparin-based anticoagulation to prophylactic or intermediate dose anticoagulation or standard treatment in hospitalized non-critically ill COVID-19 patients. The risk of bias was assessed using the Cochrane risk-of-bias tool for randomized trials and Grading of Recommendations Assessment, Development and Evaluation was applied. The primary outcome was all-cause mortality at the longest follow-up available.

RESULTS

We identified 6 multicenter RCTs involving 3297 patients from 13 countries across 4 continents. The rate of all-cause mortality was 6.2% (103/1662) in the full-dose group vs 7.7% (126/1635) in the prophylactic or intermediate dose group (Risk Ratio [RR] = 0.76; 95% confidence interval [CI] = 0.59-0.98; P = 0.037). The probabilities of any mortality difference and of NNT ≤ 100 were estimated at 98.2% and 84.5%, respectively. The risk of bias was low for all included RCTs and the strength of the evidence was "moderate."

CONCLUSION

Our meta-analysis of high-quality multicenter RCTs suggests that full-dose anticoagulation with heparin or low molecular weight heparin reduces all-cause mortality in hospitalized non-critically ill COVID-19 patients.

STUDY REGISTRATION

PROSPERO, review no. CRD42022348993.

The Conundrum of Anticoagulation for Hospitalized Patients with Covid-19

Thrombosis in patients with coronavirus disease 2019 (Covid-19) is driven by complex interactions between immune, complement, fibrinolytic, endothelial, and coagulation systems.1 In addition to venous thromboembolism (VTE), microthrombi have also been implicated in contributing to end-organ damage, such as acute respiratory distress syndrome and kidney dysfunction, as well as to overall mortality.1 As available therapies, variants, and vaccines have evolved, so have reported rates of VTE attributable to Covid-19.

Evaluation of a fast-and-frugal clinical decision algorithm ('pathways') on clinical outcomes in hospitalised patients with COVID-19 treated with anticoagulants

RATIONALE, AIMS AND OBJECTIVES

Critics have charged that evidence-based medicine (EBM) overemphasises algorithmic rules over unstructured clinical experience and intuition, but the role of structured decision support systems in improving health outcomes remains uncertain. We aim to assess if delivery of anticoagulant prophylaxis in hospitalised patients with COVID-19 according to an algorithm based on evidence-based clinical practice guideline (CPG) improved clinical outcomes compared with administration of anticoagulant treatment given at individual practitioners' discretion.

METHODS

An observational design consisting of the analysis of all acutely ill, consecutive patients (n = 1783) with confirmed COVID-19 diagnosis admitted between 10 March 2020 to 11 January 2022 to an US academic center. American Society of Haematology CPG for anticoagulant prophylaxis in hospitalised patients with COVID-19 was converted into a clinical pathway and translated into fast-and-frugal decision (FFT) tree ('algorithm'). We compared delivery of anticoagulant prophylaxis in hospitalised patients with COVID-19 according to the FFT algorithm with administration of anticoagulant treatment given at individual practitioners' discretion.

RESULTS

In an adjusted analysis, using combination of Lasso (least absolute shrinkage and selection operator) and propensity score based weighting [augmented inverse-probability weighting] statistical techniques controlling for cluster data, the algorithm did not reduce death, venous thromboembolism, or major bleeding, but helped avoid longer hospital stay [number of patients needed to be treated (NNT) = 40 (95% CI: 23-143), indicating that for every 40 patients (23-143) managed on FFT algorithm, one avoided staying in hospital longer than 10 days] and averted admission to intensive-care unit (ICU) [NNT = 19 (95% CI: 13-40)]. All model's selected covariates were well balanced. The results remained robust to sensitivity analyses used to test the stability of the findings.

CONCLUSIONS

When delivered using a structured FFT algorithm, CPG shortened the hospital stay and help avoided admission to ICU, but it did not affect other relevant outcomes.

The diverse role of heparan sulfate and other GAGs in SARS-CoV-2 infections and therapeutics

In December 2019, the global coronavirus disease 2019 (COVID-19) pandemic began in Wuhan, China. COVID-19 is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which infects host cells primarily through the angiotensin-converting enzyme 2 (ACE2) receptor. In addition to ACE2, several studies have shown the importance of heparan sulfate (HS) on the host cell surface as a co-receptor for SARS-CoV-2-binding. This insight has driven research into antiviral therapies, aimed at inhibiting the HS co-receptor-binding, e.g., by glycosaminoglycans (GAGs), a family of sulfated polysaccharides that includes HS. Several GAGs, such as heparin (a highly sulfated analog of HS), are used to treat various health indications, including COVID-19. This review is focused on current research on the involvement of HS in SARS-CoV-2 infection, implications of viral mutations, as well as the use of GAGs and other sulfated polysaccharides as antiviral agents.

Efficacy and safety of two heparin regimens for prevention of venous thromboembolism in hospitalized patients with COVID-19: a meta-analysis

Venous thromboembolism (VTE) is common in patients with coronavirus disease-2019 (COVID-19). The optimal heparin regimen remains unknown and should balance thromboembolic and bleeding risks. The aim of this study was to evaluate the efficacy and safety of standard or higher heparin regimens for the prevention of VTE in patients hospitalized due to COVID-19. We performed a systematic literature search; studies reporting on hospitalized patients with COVID-19 who received standard heparin prophylaxis vs. high (intermediate or therapeutic) heparin regimens were included if outcome events were reported by treatment group and more than 10 patients were included. Primary study outcome was in-hospital VTE. Secondary study outcomes were major bleeding (MB), all-cause death, fatal bleeding and fatal pulmonary embolism. Overall, 33 studies (11,387 patients) were included. Venous thromboembolic events occurred in 5.2% and in 8.2% of patients who received heparin prophylaxis with at high-dose or standard-dose, respectively (RR 0.71, 95% CI 0.55-0.90, I2 48.8%). MB was significantly higher in patients who received high- compared to the standard-dose (4.2% vs 2.2%, RR 1.94, 95% CI 1.47-2.56, I2 18.1%). Sub-analyses showed a slight benefit associated with high-dose heparin in patients admitted to non-intensive care unit (ICU) but not in those to ICU. No significant differences were observed for mortality outcomes. Heparin prophylaxis at high-dose reduces the risk of VTE, but increased the risk of MB compared to the standard-dose. No clinical benefit for heparin high-dose was observed for ICU setting, but its role in the non-ICU deserves further evaluation. PROSPERO registration number: CRD42021252550.

Dysregulated thrombospondin 1 and miRNA-29a-3p in severe COVID-19

Although nearly a fifth of symptomatic COVID-19 patients suffers from severe pulmonary inflammation, the mechanism of developing severe illness is not yet fully understood. To identify significantly altered genes in severe COVID-19, we generated messenger RNA and micro-RNA profiling data of peripheral blood mononuclear cells (PBMCs) from five COVID-19 patients (2 severe and 3 mild patients) and three healthy controls (HC). For further evaluation, two publicly available RNA-Seq datasets (GSE157103 and GSE152418) and one single-cell RNA-Seq dataset (GSE174072) were employed. Based on RNA-Seq datasets, thrombospondin 1 (THBS1) and interleukin-17 receptor A (IL17RA) were significantly upregulated in severe COVID-19 patients' blood. From single-cell RNA-sequencing data, IL17RA level is increased in monocytes and neutrophils, whereas THBS1 level is mainly increased in the platelets. Moreover, we identified three differentially expressed microRNAs in severe COVID-19 using micro-RNA sequencings. Intriguingly, hsa-miR-29a-3p significantly downregulated in severe COVID-19 was predicted to bind the 3'-untranslated regions of both IL17RA and THBS1 mRNAs. Further validation analysis of our cohort (8 HC, 7 severe and 8 mild patients) showed that THBS1, but not IL17RA, was significantly upregulated, whereas hsa-miR-29a-3p was downregulated, in PBMCs from severe patients. These findings strongly suggest that dysregulated expression of THBS1, IL17RA, and hsa-miR-29a-3p involves severe COVID-19.

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.

American Society of Hematology living guidelines on the use of anticoagulation for thromboprophylaxis in patients with COVID-19: January 2022 update on the use of therapeutic-intensity anticoagulation in acutely ill patients

BACKGROUND

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

OBJECTIVE

These evidence-based guidelines from the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in making decisions about the use of anticoagulation in patients with COVID-19.

METHODS

ASH formed a multidisciplinary guideline panel that included patient representatives and applied strategies to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process and performed systematic evidence reviews (through November 2021). The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assess evidence and make recommendations, which were subject to public comment. This is an update to guidelines published in February 2021 as part of the living phase of these guidelines.

RESULTS

The panel made one additional recommendation. The panel issued a conditional recommendation in favor of therapeutic-intensity over prophylactic-intensity anticoagulation in patients with COVID-19-related acute illness who do not have suspected or confirmed VTE. The panel emphasized the need for an individualized assessment of risk of thrombosis and bleeding. The panel also noted that heparin (unfractionated or low molecular weight) may be preferred because of a preponderance of evidence with this class of anticoagulants.

CONCLUSION

This conditional recommendation was based on very low certainty in the evidence, underscoring the need for additional, high-quality, randomized controlled trials comparing different intensities of anticoagulation in patients with COVID-19-related acute illness.

The pharmacology of anticoagulant drug treatment options in COVID-19 patients: reviewing real-world evidence in clinical practice

INTRODUCTION

The optimal anticoagulation strategy for venous thromboembolism (VTE) prevention among COVID-19 patients, hospitalized or in the community setting, is still challenging and largely based on real-world evidence.

AREAS COVERED

We analyzed real-world data regarding the safety and effectiveness of anticoagulant treatment, both parenteral and oral, for VTE prevention or atrial fibrillation (AF)/VTE treatment among COVID-19 patients.

EXPERT OPINION

The efficacy of low-molecular-weight heparin (LMWH) doses for VTE prevention correlates with COVID-19 disease status. LMWH prophylactic dose may be useful in COVID-19 patients at the early stage of the disease. LMWH intermediate or therapeutic dose is recommended in COVID-19 patients with an advanced stage of the disease. COVID-19 patients on VKAs therapy for atrial fibrillation (AF) and VTE should switch to NOACs in the community setting or LMWH in the hospital setting. No definitive data on de-novo starting of NOACs or VKAs therapy for VTE prevention in COVID-19 outpatients are available. In patients at high risk discharged after hospitalization due to COVID-19, thromboprophylaxis with NOACs may be considered.

Anticoagulation in hospitalized patients with COVID-19

Coronavirus disease-19 (COVID-19) includes a thromboinflammatory syndrome that may manifest with microvascular and macrovascular thrombosis. Patients with COVID-19 have a higher incidence of venous thromboembolism than other hospitalized patients. Three randomized control trials suggesting benefit of therapeutic heparin in hospitalized noncritically ill patients with COVID-19 have led to conditional guideline recommendations for this treatment. By contrast, prophylactic-dose heparin is recommended for critically ill patients. Unprecedented collaboration and rapidly funded research have improved care of hospitalized patients with COVID-19.

Efficacy and safety of heparin full-dose anticoagulation in hospitalized non-critically ill COVID-19 patients: a meta-analysis of multicenter randomized controlled trials

Arterial and venous thrombotic events in COVID-19 cause significant morbidity and mortality among patients. Although international guidelines agree on the need for anticoagulation, it is unclear whether full-dose heparin anticoagulation confers additional benefits over prophylactic-dose anticoagulation. This systematic review and meta-analysis aimed to investigate the efficacy and safety of heparin full-dose anticoagulation in hospitalized non-critically ill COVID-19 patients. We searched Pubmed/Medline, EMBASE, Clinicaltrials.gov, medRxiv.org and Cochrane Central Register of clinical trials dated up to April 2022. Randomized controlled trials (RCTs) comparing full-dose heparin anticoagulation to prophylactic-dose anticoagulation or standard treatment in hospitalized non-critically ill COVID-19 patients were included in our pooled analysis. The primary endpoint was the rate of major thrombotic events and the co-primary endpoint was the rate of major bleeding events. We identified 4 studies, all of them multicenter, randomizing 2926 patients. Major thrombotic events were 23/1524 (1.5%) in full-dose heparin anticoagulation versus 57/1402 (4.0%) in prophylactic-dose [relative risk (RR) 0.39; 95% confidence interval (CI) 0.25–0.62; p˂0.01; I² = 0%]. Clinical relevant bleeding events occurred in 1.7% (26/1524) among patients treated with heparin full anticoagulation dose compared to 1.1% (15/1403) in prophylactic-dose group (RR 1.60; 95% CI 0.85–3.03; p = 0.15; I² = 20%). Mortality was 6.6% (101/1524) versus 8.6% (121/1402) (RR 0.63; 95% CI 0.33–1.19; p = 0.15). In this meta-analysis of high quality multicenter randomized trials, full-dose anticoagulation with heparin was associated with lower rate of major thrombotic events without differences in bleeding risk and mortality in hospitalized non critically ill COVID-19 patients.

Study registration PROSPERO, review no. CRD42022301874.

Enoxaparin for primary thromboprophylaxis in symptomatic outpatients with COVID-19 (OVID): a randomised, open-label, parallel-group, multicentre, phase 3 trial

Background

COVID-19 is a viral prothrombotic respiratory infection. Heparins exert antithrombotic and anti-inflammatory effects, and might have antiviral properties. We aimed to investigate whether thromboprophylaxis with enoxaparin would prevent untoward hospitalisation and death in symptomatic, but clinically stable outpatients with COVID-19.

Methods

OVID was a randomised, open-label, parallel-group, investigator-initiated, phase 3 trial and was done at eight centres in Switzerland and Germany. Outpatients aged 50 years or older with acute COVID-19 were eligible if they presented with respiratory symptoms or body temperature higher than 37·5°C. Eligible participants underwent block-stratified randomisation (by age group 50–70 vs >70 years and by study centre) in a 1:1 ratio to receive either subcutaneous enoxaparin 40 mg once daily for 14 days versus standard of care (no thromboprophylaxis). The primary outcome was a composite of any untoward hospitalisation and all-cause death within 30 days of randomisation. Analysis of the efficacy outcomes was done in the intention-to-treat population. The primary safety outcome was major bleeding. The study was registered in ClinicalTrials.gov (NCT04400799) and has been completed.

Findings

At the predefined formal interim analysis for efficacy (50% of total study population), the independent Data Safety Monitoring Board recommended early termination of the trial on the basis of predefined statistical criteria having considered the very low probability of showing superiority of thromboprophylaxis with enoxaparin for the primary outcome under the initial study design assumptions. Between Aug 15, 2020, and Jan 14, 2022, from 3319 participants prescreened, 472 were included in the intention-to-treat population and randomly assigned to receive enoxaparin (n=234) or standard of care (n=238). The median age was 57 years (IQR 53–62) and 217 (46%) were women. The 30-day risk of the primary outcome was similar in participants allocated to receive enoxaparin and in controls (8 [3%] of 234 vs 8 [3%] of 238; adjusted relative risk 0·98; 95% CI 0·37–2·56; p=0·96). All hospitalisations were related to COVID-19. No deaths were reported during the study. No major bleeding events were recorded. Eight serious adverse events were recorded in the enoxaparin group versus nine in the control group.

Interpretation

These findings suggest thromboprophylaxis with enoxaparin does not reduce early hospitalisations and deaths among outpatients with symptomatic COVID-19. Futility of the treatment under the initial study design assumptions could not be conclusively assessed owing to under-representation of older patients and consequent low event rates.

Funding

SNSF (National Research Programme COVID-19 NRP78: 198352), University Hospital Zurich, University of Zurich, Dr-Ing Georg Pollert (Berlin), Johanna Dürmüller-Bol Foundation.

Current Effective Therapeutics in Management of COVID-19

The current pandemic due to the SARS-CoV-2 virus has caused irreparable damage globally. High importance is placed on defining current therapeutics for Coronavirus Disease 2019 (COVID-19). In this review, we discuss the evidence from pivotal trials that led to the approval of effective therapeutics in the treatment and prevention of COVID-19. We categorize them as effective outpatient and inpatient management strategies The review also attempts to contextualize the efficacy of therapeutics to the emerging variants. Vaccines, which remain the most effective prevention against hospitalization and deaths is not included in this review.

D‐dimer testing in clinical practice in the era of COVID‐19

D‐dimer is a fragment of crosslinked fibrin resulting from plasmin cleavage of fibrin clots and hence an indirect biomarker of the hemostatic system activation. Early in the coronavirus disease 2019 (COVID‐19) pandemic, several studies described coagulation disorders in affected patients, including high D‐dimer levels. Consequently, D‐dimer has been widely used in not‐yet‐approved indications. Ruling out pulmonary embolism and deep vein thrombosis in patients with low or intermediate clinical suspicion is the main application of D‐dimer. D‐dimer is also used to estimate the risk of venous thromboembolism recurrence and is included in the ISTH algorithm for the diagnosis of disseminated intravascular coagulation. Finally, numerous studies identified high D‐dimer levels as a biomarker of poor prognosis in hospitalized patients with COVID‐19. This report focuses on validated applications of D‐dimer testing in patients with and without COVID‐19.

Anticoagulant Treatment in Severe ARDS COVID-19 Patients

Patients with COVID-19 may complicate their evolution with thromboembolic events. Incidence of thromboembolic complications are high and also, patients with the critically-ill disease showed evidence of microthrombi and microangiopathy in the lung probably due to endothelial damage by directly and indirectly injured endothelial and epithelial cells. Pulmonary embolism, deep venous thrombosis and arterial embolism were reported in patients with COVID-19, and several analytical abnormal coagulation parameters have been described as well. D-dimer, longer coagulation times and lower platelet counts have been associated with poor outcomes. The use of anticoagulation or high doses of prophylactic heparin is controversial. Despite the use of anticoagulation or high prophylactic dose of heparin have been associated with better outcomes in observational studies, only in patients with non-critically ill disease benefits for anticoagulation was observed. In critically-ill patient, anticoagulation was not associated with better outcomes. Other measures such as antiplatelet therapy, fibrinolytic therapy or nebulized anticoagulants are being studied in ongoing clinical trials.

Clinical features of thrombosis and bleeding in COVID-19

Infection with the SARS-CoV-2 virus, resulting in COVID-19 disease has presented a unique scenario associated with high thrombotic rates. The risk of venous thrombosis is some 3-6 fold higher than for patients admitted to hospital for other indications and for patients who have thrombosis, mortality appears increased. Thrombosis may be a presenting feature of COVID-19. Pulmonary thrombi are the most frequent events, some related to deep vein thrombosis, but also in situ micro- and macrovascular thrombosis. Other venous thromboses include catheter and circuit-associated in patients requiring haemofiltration and ECMO. Arterial thrombosis is less commonly documented, with 3% of ICU patients having major arterial strokes and up to 9% myocardial infarction, which is likely multifactorial. Risk factors for thrombosis above those already documented in hospital settings include duration of COVID-19 symptoms before admission to hospital. Laboratory parameters associated with higher thrombotic risk include higher D-dimer, low fibrinogen and low lymphocyte count, with higher FVIII and von Willebrand factor levels indicative of more severe COVID-19 infection. All patients should receive thromboprophylaxis when admitted with COVID-19 infection, but the dose and length of treatment still remain debated. Treatment for thrombosis remains as per standard VTE guidelines, but adjustments may be required depending on other factors relevant to the patient admission.

Thromboprophylaxis in COVID‐19: Weight and severity adjusted intensified dosing

Background

Aims

Methods

Results

Conclusion

Deaths related to pulmonary embolism and cardiovascular events before and during the 2020 COVID-19 pandemic: An epidemiological analysis of data from an Italian high-risk area

BACKGROUND

Pulmonary embolism is a known complication of coronavirus disease 2019 (COVID-19). Epidemiological population data focusing on pulmonary embolism-related mortality is limited.

METHODS

Veneto is a region in Northern Italy counting 4,879,133 inhabitants in 2020. All ICD-10 codes from death certificates (1st January 2018 to 31st December 2020) were examined. Comparisons were made between 2020 (COVID-19 outbreak) and the average of the two-year period 2018-2019. All-cause, COVID-19-related and the following cardiovascular deaths have been studied: pulmonary embolism, hypertensive disease, ischemic heart disease, atrial fibrillation/flutter, and cerebrovascular diseases.

RESULTS

In 2020, a total of 56,412 deaths were recorded, corresponding to a 16% (n = 7806) increase compared to the period 2018-2019. The relative percentage increase during the so-called first and second waves was 19% and 44%, respectively. Of 7806 excess deaths, COVID-19 codes were reported in 90% of death certificates. The percentage increase in pulmonary embolism-related deaths was 27% (95%CI 19-35%), 1018 deaths during the year 2020, compared to 804 mean annual deaths in the period 2018-2019. This was more evident among men, who experience an absolute increase of 147 deaths (+45%), than in women (+67 deaths; +14%). The increase was primarily driven by deaths recorded during the second wave (+91% in October-December). An excess of deaths, particularly among men and during the second wave, was also observed for other cardiovascular diseases, notably hypertensive disease, atrial fibrillation, cerebrovascular disease, and ischemic heart disease.

CONCLUSIONS

We observed a considerable increase of all-cause mortality during the year 2020. This was mainly driven by COVID-19 and its complications. The relative increase in the number of pulmonary embolism-related deaths was more prominent during the second wave, suggesting a possible underdiagnosis during the first wave.