Therapeutic Anticoagulation with Heparin in Noncritically Ill Patients with Covid-19

Tenecteplase With Concomitant Anticoagulation for Acute Respiratory Failure in Patients With COVID-19: A Randomized Controlled Trial

Background Pulmonary thrombosis and thromboembolism play a significant role in the physiologic derangements seen in COVID-19 acute respiratory failure. The effect of thrombolysis with tenecteplase on patient outcomes is unknown. Methods We conducted a randomized, controlled, double-blind, phase II trial comparing tenecteplase versus placebo in patients with COVID-19 acute respiratory failure (NCT04505592). Patients with COVID-19 acute respiratory failure were randomized to tenecteplase 0.25 mg/kg or placebo in a 2:1 proportion. Both groups received therapeutic heparin for at least 72 hours. Results Thirteen patients were included in the trial. Eight patients were randomized to tenecteplase and five were randomized to placebo. At 28 days, 63% (n = 5) of patients assigned to the treatment group were alive and free from respiratory failure compared to 40% (n = 2) in the placebo arm (p = 0.43). Mortality at 28 days was 25% (n = 2) in the treatment arm and 20% (n = 1) in the control arm (p = 1.0). No patients in the treatment arm developed renal failure by 28 days compared to 60% (n = 3) in the placebo arm (p = 0.07). Major bleeding occurred in 25% (n = 2) of the treatment arm and 20% (n = 1) in the placebo arm; however, no patients in either arm experienced intracranial hemorrhage. Conclusions Tenecteplase with concomitant heparin may improve patient outcomes in patients with COVID-19 respiratory failure. As this study was limited by a small sample size, larger confirmatory studies are needed.

Which are the optimal thromboprophylaxis strategies for hospitalized patients with COVID-19? current controversies

Novel coronavirus 2019 (COVID-19) represents a significant risk factor for the development of venous thromboembolism (VTE) in hospitalized with both moderate and severe/critical COVID-19. Herein, we present a brief updated review on emerging robust data on diverse thromboprophylaxis strategies used to mitigate VTE complications, as well as a personal point of view of current controversies in regards the use of therapeutic and prophylactic anticoagulation strategies, particularly in the moderately-ill subgroup of patients with COVID-19.

Effect of antiplatelet therapy after COVID-19 diagnosis: A systematic review with meta-analysis and trial sequential analysis

BACKGROUND

Coronavirus disease 2019 (COVID-19) may predispose patients to thrombotic disease in the venous and arterial circulations.

METHODS

Based on the current debate on antiplatelet therapy in COVID-19 patients, we performed a systematic review and meta-analysis to investigate the effect of antiplatelet treatments. We searched PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and Web of Science on February 1, 2023, and only included Randomized clinical trials. The study followed PRISMA guidelines and used Random-effects models to estimate the pooled percentage and its 95% CI.

RESULTS

Five unique eligible studies were included, covering 17,950 patients with COVID-19. The result showed no statistically significant difference in the relative risk of all-cause death in antiplatelet therapy versus non-antiplatelet therapy (RR 0.94, 95% CI, 0.83-1.05, P = 0.26, I2 = 32%). Compared to no antiplatelet therapy, patients who received antiplatelet therapy had a significantly increased relative risk of major bleeding (RR 1.81, 95%CI 1.09-3.00, P = 0.02, I2 = 16%). The sequential analysis suggests that more RCTs are needed to draw more accurate conclusions. This systematic review and meta-analysis revealed that the use of antiplatelet agents exhibited no significant benefit on all-cause death, and the upper bound of the confidence interval on all-cause death (RR 95% CI, 0.83-1.05) suggested that it was unlikely to be a substantiated harm risk associated with this treatment. However, evidence from all RCTs suggested a high risk of major bleeding in antiplatelet agent treatments.

CONCLUSION

According to the results of our sequential analysis, there is not enough evidence available to support or negate the use of antiplatelet agents in COVID-19 cases. The results of ongoing and future well-designed, large, randomized clinical trials are needed.

Treatments for COVID-19

The treatment for COVID-19 has evolved rapidly since the start of the pandemic and now consists mainly of antiviral and immunomodulatory agents. Antivirals, such as remdesivir and nirmatrelvir-ritonavir, have proved to be most useful earlier in illness (e.g., as outpatient therapy) and for less severe disease. Immunomodulatory therapies, such as dexamethasone and interleukin-6 or Janus kinase inhibitors, are most useful in severe disease or critical illness. The role of anti-SARS-CoV-2 monoclonal antibodies has diminished because of the emergence of viral variants that are not anticipated to be susceptible to these treatments, and there still is not a consensus on the use of convalescent plasma. COVID-19 has been associated with increased rates of venous thromboembolism, but the role of antithrombotic therapy is limited. Multiple investigational agents continue to be studied, which will alter current treatment paradigms as new data are released.

Risk factors for thromboembolic events in patients hospitalized for COVID-19 pneumonia in a general ward and requiring treatment with oxygen

PURPOSE

To assess risk factors for arterial and venous thromboses (AVT) in patients hospitalized in general wards for COVID-19 pneumonia and requiring oxygen therapy.

METHODS

Our study was based on three randomized studies conducted as part of the CORIMUNO-19 platform in France between 27 March and 26 April 2020. Adult inpatients with COVID-19 pneumonia requiring at least 3 l/min of oxygen but not ventilation were randomized to receive standard care alone or standard care plus biologics. Patients were followed up for 3 months, and adverse events were documented. Risk factor for AVT and bleeding was identified by analyzing clinical, laboratory, and treatment data at baseline among the 315 patients with complete datasets. A Fine and Gray model was used to take account of competing events.

RESULTS

During the 3-month follow-up period, 39 AVT occurred in 38 (10%) of the 388 patients: 26 deep vein thromboses and/or pulmonary embolisms in 25 (6%) patients, and 14 arterial thrombotic events in 13 (3%) patients. A history of diabetes at inclusion [sHR (95% CI) = 2.65 (1.19-5.91), P = .017] and the C-reactive protein (CRP) level (sHR = 1 [1-1.01], P = .049) were significantly associated with an elevated risk of thrombosis. Obesity was not associated with a higher risk of thrombosis (sHR = 1.01 [0.4-2.57], P = .98). The CRP level and diabetes were not risk factors for hemorrhage.

CONCLUSION

Among patients hospitalized in general wards for COVID-19 pneumonia during the first wave of the epidemic, diabetes (but not obesity) and a high CRP level were risk factors for AVT. The use of higher doses of anticoagulant in these high-risk patients could be considered.

Choice and Duration of Anticoagulation for Venous Thromboembolism

Venous thromboembolism (VTE) is a prevalent medical condition with high morbidity, mortality, and associated costs. Anticoagulation remains the main treatment for VTE, though the decision on when, how, and for how long to administer anticoagulants is increasingly complex. This review highlights the different phases of VTE management, with special circumstances for consideration such as antiphospholipid syndrome, coronary artery disease, cancer-associated thrombus, COVID-19, and future anticoagulation options. Anticoagulation management will continue to be a complex decision, applying evidence-based medicine to individual patients with the hope of maximizing effectiveness while minimizing risks.

Thromboinflammation in acute injury: infections, heatstroke, and trauma

Tissue microcirculation is essential for the maintenance of organ homeostasis. Following acute infections, activation of coagulation and inflammation, which are critical interconnected responses, lead to thromboinflammation and microthrombosis, thereby contributing to multiorgan dysfunction. Sepsis is the most common underlying disease and has been extensively studied. However, the COVID-19 pandemic further illustrated the pathomechanisms of diseases in which thromboinflammation plays a critical role. During thromboinflammation, injury to monocytes, neutrophils, platelets, and endothelial cells, along with coagulation and complement activation, was further characterized. Thrombin is pivotal in orchestrating thrombosis and inflammation and has long been considered a potential therapeutic target in sepsis. Although thromboprophylaxis for venous thromboembolism with heparins is part of standard management for COVID-19, it also potentially attenuates organ dysfunction due to thrombotic sequela. In contrast, the effectiveness of anticoagulation with heparin, antithrombin, or thrombomodulin to reduce mortality has not conclusively been proven in sepsis. Nonetheless, thromboinflammation has also been reported as an important pathophysiologic mechanism in other critical illnesses, including heatstroke, trauma, and ischemia/reperfusion injury, and may provide a potential therapeutic target for future clinical studies.

Thrombo-inflammatory response in hospitalised patients with COVID-19: a single institution experience

BACKGROUND

Severe COVID-19 causes acute inflammation, which is complicated by venous thromboembolism events (VTE). However, it is unclear if VTE risk has evolved over time since the COVID-19 outbreak.

AIMS

To determine markers of thrombo-inflammation and rates of symptomatic VTE in patients hospitalised for COVID-19 in a metropolitan hospital in Sydney, Australia.

METHODS

A retrospective, single-centre, cohort study was performed by reviewing electronic medical records of consecutive patients admitted to Royal Prince Alfred Hospital between March 2020 and September 2021. This period included three waves of COVID-19 outbreaks in Australia with the ancestral, alpha and delta variants. Standard coagulation assays and inflammatory markers were recorded over 4 weeks.

RESULTS

A total of 205 patients were consecutively admitted during the study period. Activated partial thromboplastin time, neutrophil count and C-reactive protein (CRP) were significantly increased in patients hospitalised in the intensive care unit (ICU) compared with non-ICU patients. The use of anti-inflammatory medication increased in 2021 compared with 2020. The mortality rate was 7.3% in our cohort. Ninety-four per cent of patients received anticoagulation with 6.3% of patients developing VTE.

CONCLUSION

We observed lower rates of VTE compared to the internationally reported rate for the same period. We conclude that in the setting of controlled hospital admission rate and standard anticoagulation guidelines, COVID-19 resulted in similar thrombo-inflammatory response and VTE rates over the first 1.5 years of the pandemic.

Coronavirus Disease 2019 (COVID-19) and Venous Thromboembolism During Pregnancy and Postpartum

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with increased risk for macro- and micro-thrombi. Consensus guidelines recommend use of thromboprophylaxis in nonobstetric patients with SARS-CoV-2 infection admitted to the hospital. National-level studies evaluating venous thromboembolism (VTE) among pregnant and postpartum individuals with and without SARS-CoV-2 infection have not been completed. We performed a retrospective cohort study of individuals aged 18 years or older delivering at more than 20 weeks of gestation with data in the MarketScan Commercial Insurance Database from 2016 through 2020. Of 811,008 deliveries, SARS-CoV-2 infection during pregnancy or through 6 weeks postpartum was associated with increased risk for VTE compared with no infection (1.0% vs 0.5%, adjusted hazard ratio 2.62, 95% CI 1.60-4.29). Findings support further consideration of thromboprophylaxis in the obstetric population with SARS-CoV-2 infection.

COVID-19 thromboprophylaxis. New evidence

Recent publications have questioned the efficacy of using therapeutic or intermediate doses of low molecular weight heparin (LMWH) in COVID-19 patients, especially in the most severe patients. In order to update these recommendations, a non-systematic review has been carried out in the main medical databases. A total of 14 randomized clinical trials, 14 meta-analyses and the recommendations of 12 scientific societies were selected, stratified according to the type of patient (outpatient, hospitalized, admitted to critical care or post-discharge). The efficacy of LMWH and other therapeutic approaches (rivaroxaban, apixaban, sulodexide, acetylsalicylic acid and P2Y12 inhibitors) has been analyzed. The findings recommend using standard doses of LMWH as thromboprophylaxis in critically hospitalized COVID-19 patients and therapeutic doses in non-critically hospitalized patients if the risk of bleeding is low. In outpatients and those discharged from the hospital, LMWH could be used at a prophylactic dose if there are thrombotic risk factors, and the bleeding risk is low. It is not recommended to associate antiplatelet agents with LMWH unless previously indicated.

Design and Execution of Clinical Trials in the Cardiac Intensive Care Unit

Clinical practice in the contemporary cardiac intensive care unit (CICU) has evolved significantly over the last several decades. With more frequent multisystem organ failure, increasing use of advanced respiratory support, and the advent of new mechanical circulatory support platforms, clinicians in the CICU are increasingly managing patients with complex comorbid disease in addition to their high-acuity cardiovascular illnesses. Here, the authors discuss challenges associated with traditional trial design in the CICU setting and review novel clinical trial designs that may facilitate better evidence generation in the CICU.

Low-molecular-weight heparin for the prevention of clinical worsening in severe non-critically ill COVID-19 patients: a joint analysis of two randomized controlled trials

Coronavirus disease 2019 (COVID-19) carries a high risk of vascular thrombosis. However, whether a specific anticoagulation intensity strategy may prevent clinical worsening in severe COVID-19 patients is still debated. We conducted a joint analysis of two randomized controlled trials, COVID-19 HD (NCT044082359) and EMOS-COVID (NCT04646655), to assess the efficacy and safety of two anticoagulant regimens in hospitalized severe COVID-19 patients. Subjects with COVID-19-associated respiratory compromise and/or coagulopathy were randomly assigned to low (4000 IU qd) or high (70 IU Kg-1 every 12 h) enoxaparin dose. The primary efficacy endpoint was clinical worsening within 30 days, defined as the occurrence of at least one of the following events, whichever came first: in-hospital death, evidence of arterial or venous thromboembolism, acute myocardial infarction, need for either continuous positive airway pressure (CPAP) or non-invasive ventilation (NIV) in patients receiving standard oxygen therapy or none at randomization, and need for mechanical ventilation in any patient. The safety endpoint was major bleeding. We estimated the relative risk (RR) and its 95% confidence interval (CI) for the outcomes. Among 283 patients included in the study (144 in the low-dose and 139 in the high-dose group), 118 (41.7%) were on NIV or CPAP at randomization. 23/139 (16.5%) patients in the high-dose group reached the primary endpoint compared to 33/144 (22.9%) in the low-dose group (RR 0.72, 95% CI 0.45-1.17). No major bleeding was observed. No significant differences were found in the clinical worsening of hospitalized COVID-19 patients treated with high versus low doses of enoxaparin.

Thromboembolic complications after COVID-19 in kidney transplant recipients

AIM

Increased venous thrombosis and arterial embolism rates are observed in the general population during or after COVID-19. Data regarding the kidney transplant population are scarce. In this study, we aim to investigate the thrombotic complications and risk factors associated with thrombotic complications in kidney transplant patients.

METHODS

This retrospective observational study included adult kidney transplant recipients diagnosed with COVID-19 between March 2020 and June 2022. The endpoint was the occurrence of thromboembolic events.

RESULTS

Four hundred and sixty-nine patients were followed for a median of 10.8 months after COVID-19. Forty patients (8.5%) died. Thromboembolic complications developed in 51 (11.9%) of the surviving patients. Twenty-four patients with thromboembolic events were receiving prophylactic anticoagulation before the event. The patients with mild, moderate, and severe COVID-19 were 292, 129, and 48, respectively. Patients with moderate COVID-19 had a significantly higher percentage of thromboembolic complications than patients with mild COVID-19. Older age, prior heart disease, and moderate COVID-19 were significantly associated with thromboembolic events. The incidence of thromboembolic events after COVID-19 is 10.9 per 100 patient-year.

CONCLUSION

Thromboembolic complications were observed at increased rates in kidney transplant recipients after COVID-19. Therefore, prospective and cohort studies for post-COVID-19 complications regarding the treatment modalities are urgently needed.

COVID-19 Pneumonia and Cytokine Storm Syndrome

Virus-associated cytokine storm syndrome (CSS) has been recognized for a long time and the classic viruses associated are the herpes viruses EBV, CMV, and HHV-8 as described in chapters IVa,b. In addition, pandemic viruses such as influenza, SARS, and MERS can result in severe CSS that might ultimately lead to severe acute respiratory distress syndrome (ARDS) and death [1-3]. A new pandemic caused by SARS-CoV-2 that started in 2019 has defined another chapter in the virus-associated CSS. The clinical spectrum of SARS-CoV-2 infection has many faces. In most people, it will be asymptomatic, but it can also result in severe COVID-19 pneumonia, ARDS, and multiorgan failure depending on age, comorbidities, and immune status [4]. In addition, this pandemic has known many different stages and developed in a unique way in the first 2 years. It started in a setting where there was no immunity to the virus and after a year, highly effective vaccines were introduced and herd immunity built up over time. However, vaccine effectiveness was waning over time depending on multiple factors, and novel variant strains of the virus circulated across different areas in the world. Antiviral therapy was developed and introduced, and treatment changed from giving no immunomodulatory treatment, followed by the introduction of corticosteroids [5], and later the addition of more targeted strategies such as JAK inhibitors [6] and blocking IL-6 signaling [7]. Therefore, the scientific literature published on COVID-19 must be seen in the context of a highly dynamic and rapidly changing pandemic, making it difficult to compare results from early studies to more recent reports even within 2 years. Still, a lot has been learned over a very short period. It has become apparent that severe COVID-19 is predominantly a disease of immune dysregulation with components that can be defined as CSS. It has unique features and overlapping characteristics with other CSSs, and immunological treatment addressing the CSS has been extensively explored, which will be described here.

Clinical trials of pharmacological interventions for SARS-CoV-2 published in leading medical journals report adherence but not how it was assessed

AIMS

Adherence to pharmacological interventions in clinical trials is crucial for accurate identification of beneficial and adverse outcomes. The ways in which adherence to interventions should be reported in trial publications are described in the Template for Intervention Description and Replication (TIDieR), a 12-item extension of the Consolidated Standards of Reporting Trials reporting guidelines. The objective of this study was to assess compliance with TIDieR Items 11 and 12 of randomized controlled trials (RCTs) of interventions in SARS-CoV-2 infection published in 5 selected journals during 2021.

METHODS

We assessed pharmacological interventions for SARS-CoV-2 infection reported in RCTs published in 2021 in the Annals of Internal Medicine, The BMJ, JAMA, The Lancet and The New England Journal for Medicine for compliance with TIDieR items addressing intervention adherence (Items 11 and 12). We calculated proportional adherence for pharmacological and comparator interventions where available.

RESULTS

We found 75 eligible RCTs. Twenty-eight (37%) reported results of SARS-CoV-2 vaccinations. Compliance with Items 11 and 12 could be assessed in 71 of these 75. Of the 71 RCTs, 37 (52%) reported how adherence was assessed (Item 11), and 70 reported adherence rates (Item 12). Only 1 of the 71 RCTs (1.4%, 0-7.6%) fully complied with TIDieR Items 11 and 12.

CONCLUSION

Half of RCTs of SARS-CoV-2 pharmacological interventions published in leading medical journals in 2021 complied with reporting of how adherence assessments were made and almost none complied with both TIDieR Items 11 and 12. The implications for interpretation, application and replication of findings based on these publications warrant consideration.

Factors related to serum levels of intercellular adhesion molecule-1 in probable COVID-19 patients in surgical treatment: an observational study

Introduction

COVID-19 causes a systemic inflammatory response, involving dysregulation and misexpression of many inflammatory cytokines. The recruitment and activation of inflammatory cells depend on the expression of many classes of inflammatory mediators, with increased expression of endothelial cell adhesion molecules being related to COVID-19 disease severity. With the World Health Organization having recently updated case definitions to suspect, probable, and confirmed, this study aimed to measure the mean value of intercellular adhesion molecule 1 (ICAM-1) and its relation to suspected COVID-19.

Methods

all suspected patients (n=20) were hospitalized and treated following the Indonesian National Guidelines for COVID-19 management. ICAM-1 levels were measured on days 1 and 7, demographic data were recorded, and routine blood count values were measured and additionally considered.

Results

the results showed that the levels of ICAM-1 in the 1st-day group (mean 271.3 ng/ml) were higher than those in the 7th-day group (mean 253.9 ng/ml). This difference was statistically significant (p = 0.00, p ≤ 0.05). All of the patients with suspected COVID-19 were included in this study and tested for COVID-19 by reverse transcription polymerase chain reaction (RT-PCR) testing. A total of 10 patients were confirmed positive with a COVID-19 infection, with elevated ICAM-1 levels compared to the confirmed negative patients (with a mean 1st day 296.8 versus a mean 7th day 279.0 ng/ml). ICAM-1 levels of all patients decreased by the seventh day.

Conclusion

the mean value of ICAM-1 levels for patients with confirmed positive COVID-19 cases was higher than those with suspected COVID-19 cases.

Rethinking coagulation: from enzymatic cascade and cell-based reactions to a convergent model involving innate immune activation

ABSTRACT

Advancements in the conceptual thinking of hemostasis and thrombosis have been catalyzed by major developments within health research over several decades. The cascade model of coagulation was first described in the 1960s, when biochemistry gained prominence through innovative experimentation and technical developments. This was followed by the cell-based model, which integrated cellular coordination to the enzymology of clot formation and was conceptualized during the growth period in cell biology at the turn of the millennium. Each step forward has heralded a revolution in clinical therapeutics, both in procoagulant and anticoagulant treatments to improve patient care. In current times, the COVID-19 pandemic may also prove to be a catalyst: thrombotic challenges including the mixed responses to anticoagulant treatment and the vaccine-induced immune thrombotic thrombocytopenia have exposed limitations in our preexisting concepts while simultaneously demanding novel therapeutic approaches. It is increasingly clear that innate immune activation as part of the host response to injury is not separate but integrated into adaptive clot formation. Our review summarizes current understanding of the major molecules facilitating such a cross talk between immunity, inflammation and coagulation. We demonstrate how such effects can be layered upon the cascade and cell-based models to evolve conceptual understanding of the physiology of immunohemostasis and the pathology of immunothrombosis.

Simvastatin in Critically Ill Patients with Covid-19

BACKGROUND

The efficacy of simvastatin in critically ill patients with coronavirus disease 2019 (Covid-19) is unclear.

METHODS

In an ongoing international, multifactorial, adaptive platform, randomized, controlled trial, we evaluated simvastatin (80 mg daily) as compared with no statin (control) in critically ill patients with Covid-19 who were not receiving statins at baseline. The primary outcome was respiratory and cardiovascular organ support-free days, assessed on an ordinal scale combining in-hospital death (assigned a value of -1) and days free of organ support through day 21 in survivors; the analyis used a Bayesian hierarchical ordinal model. The adaptive design included prespecified statistical stopping criteria for superiority (>99% posterior probability that the odds ratio was >1) and futility (>95% posterior probability that the odds ratio was <1.2).

RESULTS

Enrollment began on October 28, 2020. On January 8, 2023, enrollment was closed on the basis of a low anticipated likelihood that prespecified stopping criteria would be met as Covid-19 cases decreased. The final analysis included 2684 critically ill patients. The median number of organ support-free days was 11 (interquartile range, -1 to 17) in the simvastatin group and 7 (interquartile range, -1 to 16) in the control group; the posterior median adjusted odds ratio was 1.15 (95% credible interval, 0.98 to 1.34) for simvastatin as compared with control, yielding a 95.9% posterior probability of superiority. At 90 days, the hazard ratio for survival was 1.12 (95% credible interval, 0.95 to 1.32), yielding a 91.9% posterior probability of superiority of simvastatin. The results of secondary analyses were consistent with those of the primary analysis. Serious adverse events, such as elevated levels of liver enzymes and creatine kinase, were reported more frequently with simvastatin than with control.

CONCLUSIONS

Although recruitment was stopped because cases had decreased, among critically ill patients with Covid-19, simvastatin did not meet the prespecified criteria for superiority to control. (REMAP-CAP ClinicalTrials.gov number, NCT02735707.).

Enoxaparin improves COVID-19 by reducing Neutrophils Extracellular Traps (NETs) production

BACKGROUND

COVID-19 causes consequences such as imbalance of the immune system and thrombotic events. During the infection process, NETs in excess induce a pro-inflammatory response and disseminated intravascular coagulation. We evaluated the role of enoxaparin as a potential inhibitor of NETs.

METHODS

K18-hACE2 animals infected with the SARS-CoV-2 virus and a group of 23 individuals admitted to the hospital with COVID-19 treated with enoxaparin or without treatment and controls without the disease were included.

RESULTS

Enoxaparin decreased the levels of NETs, reduced the signs of the disease and mitigated lung damage in the animals infected with SARS-CoV-2. These effects were partially associated with prevention of SARS-CoV-2 entry and NETs synthesis. Clinical data revealed that treatment with enoxaparin decreased the levels of inflammatory markers, the levels of NETs in isolated neutrophils and the organ dysfunction.

CONCLUSION

This study provides evidence for the beneficial effects of enoxaparin in COVID-19 in addition to its anticoagulant role.

It's in the blood: a review of the hematological system in SARS-CoV-2-associated COVID-19

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to an unprecedented global healthcare crisis. While SARS-CoV-2-associated COVID-19 affects primarily the respiratory system, patients with COVID-19 frequently develop extrapulmonary manifestations. Notably, changes in the hematological system, including lymphocytopenia, neutrophilia and significant abnormalities of hemostatic markers, were observed early in the pandemic. Hematological manifestations have since been recognized as important parameters in the pathophysiology of SARS-CoV-2 and in the management of patients with COVID-19. In this narrative review, we summarize the state-of-the-art regarding the hematological and hemostatic abnormalities observed in patients with SARS-CoV-2-associated COVID-19, as well as the current understanding of the hematological system in the pathophysiology of acute and chronic SARS-CoV-2-associated COVID-19.

Antithrombotic Therapy in Arterial Thrombosis and Thromboembolism in COVID-19: An American College of Chest Physicians Expert Panel Report

BACKGROUND

Evidence increasingly shows that the risk of thrombotic complications in COVID-19 is associated with a hypercoagulable state. Several organizations have released guidelines for the management of COVID-19-related coagulopathy and prevention of VTE. However, an urgent need exists for practical guidance on the management of arterial thrombosis and thromboembolism in this setting.

RESEARCH QUESTION

What is the current available evidence informing the prevention and management of arterial thrombosis and thromboembolism in patients with COVID-19?

STUDY DESIGN AND METHODS

A group of approved panelists developed key clinical questions by using the Population, Intervention, Comparator, and Outcome (PICO) format that address urgent clinical questions regarding prevention and management of arterial thrombosis and thromboembolism in patients with COVID-19. Using MEDLINE via PubMed, a literature search was conducted and references were screened for inclusion. Data from included studies were summarized and reviewed by the panel. Consensus for the direction and strength of recommendations was achieved using a modified Delphi survey.

RESULTS

The review and analysis of the literature based on 11 PICO questions resulted in 11 recommendations. Overall, a low quality of evidence specific to the population with COVID-19 was found. Consequently, many of the recommendations were based on indirect evidence and prior guidelines in similar populations without COVID-19.

INTERPRETATION

The existing evidence and panel consensus do not suggest a major departure from the management of arterial thrombosis according to recommendations predating the COVID-19 pandemic. Data on the optimal strategies for prevention and management of arterial thrombosis and thromboembolism in patients with COVID-19 are sparse. More high-quality evidence is needed to inform management strategies in these patients.

Platelet Factor 4 Antibodies and Severe AKI

Key Points

Patients testing positive for platelet factor 4 antibodies have a >50% higher odds of developing severe AKI compared with those who test negative. The relationship between platelet factor 4 antibodies and severe AKI was independent of demographics, comorbidities, laboratory values, and severity-of-illness characteristics.

Background

Heparin-induced thrombocytopenia, which results from production of antibodies that bind to heparin-platelet factor 4 (PF4) complexes, is a hypercoagulable state associated with considerable morbidity and mortality due to thrombotic complications. We investigated whether PF4 antibodies are associated with an increased risk of AKI.

Methods

We conducted a cohort study of hospitalized adults who underwent testing for PF4 antibodies at two large medical centers in Boston between 2015 and 2021. The primary exposure was PF4 test positivity. The primary outcome was severe AKI, defined by Kidney Disease: Improving Global Outcomes stage 3 as a ≥3-fold increase in serum creatinine or receipt of KRT within 7 days after the PF4 test. We used multivariable logistic regression to adjust for potential confounders.

Results

A total of 4224 patients were included in our analysis, 469 (11.1%) of whom had a positive PF4 test. Severe AKI occurred in 50 of 469 patients (10.7%) with a positive PF4 test and in 235 of 3755 patients (6.3%) with a negative test (unadjusted odds ratio, 1.79 [95% confidence interval, 1.30 to 2.47]). In multivariable analyses adjusted for demographics, comorbidities, laboratory values, and severity-of-illness characteristics, PF4 test positivity remained associated with a higher risk of severe AKI (adjusted odds ratio, 1.56 [95% confidence interval, 1.10 to 2.20]).

Conclusions

Among hospitalized adults, the presence of PF4 antibodies is independently associated with a 56% higher odds of developing severe AKI. Additional studies are needed to investigate potential mechanisms that may underlie these findings, such as pathogenic effects of PF4 antibodies on the microvasculature of the kidneys.

Subgroup analyses in venous thromboembolism trials reporting pharmacological interventions: A systematic review

INTRODUCTION

Randomized controlled trials (RCTs) that conduct subgroup analyses have the potential to provide information on treatment decisions in specific groups of patients from heterogeneous populations. Although we understand several factors can modify the incidence of venous thromboembolism (VTE) and the benefit/risk ratio of anticoagulation treatments, further evidence is warranted to show the heterogeneity of treatment effects in different subgroups of patients.

AIMS

The primary purpose was to evaluate the appropriateness and interpretation of subgroup analysis performed on VTE RCTs reporting pharmacological interventions.

MATERIALS AND METHODS

A systematic review of RCTs published between January 2017 and January 2022 was conducted. Claims of subgroup effects were evaluated with predefined criteria. High-quality claims of subgroup effect were further analyzed and discussed.

RESULTS

Overall, 28 RCTs with a generally low bias risk were included. The purposes of the treatments included pharmacologic thromboprophylaxis (17), therapeutic dose anticoagulation (9), and catheter-directed pharmacologic thrombolysis (2). The evaluated subgroup analyses generally presented: a high number of subgroup analyses reported, a lack of prespecification, and a lack of usage of statistical tests for interaction. The authors reported 13 claims of subgroup effect; only two were considered potentially reliable to represent heterogeneity in the direction or magnitude of treatment effect.

CONCLUSIONS

Subgroup analyses of VTE RCTs reporting pharmacologic interventions are generally methodologically poor. Most claims of subgroup effect did not meet critical criteria and lacked credibility. Clinicians in this field may proceed with scepticism when assessing claims of subgroup effects due to methodological concerns and misleading interpretations.

COVID-19 and the Concept of Thrombo-Inflammation: Review of the Relationship between Immune Response, Endothelium and Coagulation

COVID-19, caused by the SARS-CoV-2 virus, has revealed a complex interplay between inflammation and coagulation, leading to the emergence of the concept of thrombo-inflammation. This concept recognizes that COVID-19 is not solely a respiratory illness, but a systemic disease with significant vascular and hematological components. COVID-19 is associated with an unusual prothrombotic state, with intense endothelial activation leading to vasculopathy, cytokine storm, complement system activation and a hypercoagulability state (the activation of platelets and the coagulation cascade, impaired fibrinolysis). The aim of this review is to discuss the different pathological pathways described in COVID-19 that lead to thromboembolic events. Widespread vaccination and post-COVID-19 immunization allows control over the severity of this pandemic. A better understanding of the pathophysiology of COVID-19 can improve the management of frail patients who are hospitalized in intensive care units.

Intravenous Vitamin C for Patients Hospitalized With COVID-19: Two Harmonized Randomized Clinical Trials

Importance

The efficacy of vitamin C for hospitalized patients with COVID-19 is uncertain.

Objective

To determine whether vitamin C improves outcomes for patients with COVID-19.

Design, Setting, and Participants

Two prospectively harmonized randomized clinical trials enrolled critically ill patients receiving organ support in intensive care units (90 sites) and patients who were not critically ill (40 sites) between July 23, 2020, and July 15, 2022, on 4 continents.

Interventions

Patients were randomized to receive vitamin C administered intravenously or control (placebo or no vitamin C) every 6 hours for 96 hours (maximum of 16 doses).

Main Outcomes and Measures

The primary outcome was a composite of organ support-free days defined as days alive and free of respiratory and cardiovascular organ support in the intensive care unit up to day 21 and survival to hospital discharge. Values ranged from -1 organ support-free days for patients experiencing in-hospital death to 22 organ support-free days for those who survived without needing organ support. The primary analysis used a bayesian cumulative logistic model. An odds ratio (OR) greater than 1 represented efficacy (improved survival, more organ support-free days, or both), an OR less than 1 represented harm, and an OR less than 1.2 represented futility.

Results

Enrollment was terminated after statistical triggers for harm and futility were met. The trials had primary outcome data for 1568 critically ill patients (1037 in the vitamin C group and 531 in the control group; median age, 60 years [IQR, 50-70 years]; 35.9% were female) and 1022 patients who were not critically ill (456 in the vitamin C group and 566 in the control group; median age, 62 years [IQR, 51-72 years]; 39.6% were female). Among critically ill patients, the median number of organ support-free days was 7 (IQR, -1 to 17 days) for the vitamin C group vs 10 (IQR, -1 to 17 days) for the control group (adjusted proportional OR, 0.88 [95% credible interval {CrI}, 0.73 to 1.06]) and the posterior probabilities were 8.6% (efficacy), 91.4% (harm), and 99.9% (futility). Among patients who were not critically ill, the median number of organ support-free days was 22 (IQR, 18 to 22 days) for the vitamin C group vs 22 (IQR, 21 to 22 days) for the control group (adjusted proportional OR, 0.80 [95% CrI, 0.60 to 1.01]) and the posterior probabilities were 2.9% (efficacy), 97.1% (harm), and greater than 99.9% (futility). Among critically ill patients, survival to hospital discharge was 61.9% (642/1037) for the vitamin C group vs 64.6% (343/531) for the control group (adjusted OR, 0.92 [95% CrI, 0.73 to 1.17]) and the posterior probability was 24.0% for efficacy. Among patients who were not critically ill, survival to hospital discharge was 85.1% (388/456) for the vitamin C group vs 86.6% (490/566) for the control group (adjusted OR, 0.86 [95% CrI, 0.61 to 1.17]) and the posterior probability was 17.8% for efficacy.

Conclusions and Relevance

In hospitalized patients with COVID-19, vitamin C had low probability of improving the primary composite outcome of organ support-free days and hospital survival.

Trial Registration

ClinicalTrials.gov Identifiers: NCT04401150 (LOVIT-COVID) and NCT02735707 (REMAP-CAP).

Platelet aggregates detected using quantitative phase imaging associate with COVID-19 severity

BACKGROUND

The clinical spectrum of acute SARS-CoV-2 infection ranges from an asymptomatic to life-threatening disease. Considering the broad spectrum of severity, reliable biomarkers are required for early risk stratification and prediction of clinical outcomes. Despite numerous efforts, no COVID-19-specific biomarker has been established to guide further diagnostic or even therapeutic approaches, most likely due to insufficient validation, methodical complexity, or economic factors. COVID-19-associated coagulopathy is a hallmark of the disease and is mainly attributed to dysregulated immunothrombosis. This process describes an intricate interplay of platelets, innate immune cells, the coagulation cascade, and the vascular endothelium leading to both micro- and macrothrombotic complications. In this context, increased levels of immunothrombotic components, including platelet and platelet-leukocyte aggregates, have been described and linked to COVID-19 severity.

METHODS

Here, we describe a label-free quantitative phase imaging approach, allowing the identification of cell-aggregates and their components at single-cell resolution within 30 min, which prospectively qualifies the method as point-of-care (POC) testing.

RESULTS

We find a significant association between the severity of COVID-19 and the amount of platelet and platelet-leukocyte aggregates. Additionally, we observe a linkage between severity, aggregate composition, and size distribution of platelets in aggregates.

CONCLUSIONS

This study presents a POC-compatible method for rapid quantitative analysis of blood cell aggregates in patients with COVID-19.

Step up to the platelet: Role of platelets in inflammation and infection

Platelets are anucleated cells derived from megakaryocytes that are primarily responsible for hemostasis. However, in recent years, these cytoplasts have become increasingly recognized as immune cells, able to detect, interact with, and kill pathogens. As platelets are involved in both immunity and coagulation, they have a central role in immunothrombosis, a physiological process in which immune cells induce the formation of microthrombi to both prevent the spread of pathogens, and to help facilitate clearance. In this review, we will highlight the role of platelets as key players in the inflammatory and innate immune response against bacterial and viral infection, including direct and indirect interactions with pathogens and other immune cells.

Distribution of Aeration and Pulmonary Blood Volume in Healthy, ARDS and COVID-19 Lungs: A Dual-Energy Computed Tomography Retrospective Cohort Study

RATIONALE AND OBJECTIVES

Few reports have studied lung aeration and perfusion in normal lungs, COVID-19, and ARDS from other causes (NC-ARDS) using dual-energy computed tomography pulmonary angiograms (DE-CTPA). To describe lung aeration and blood-volume distribution using DE-CTPAs of patients with NC-ARDS, COVID-19, and controls with a normal DE-CTPA ("healthy lungs"). We hypothesized that each of these conditions has unique ranges of aeration and pulmonary blood volumes.

MATERIALS AND METHODS

This retrospective, single-center study of DE-CTPAs included patients with COVID-19, NC-ARDS (Berlin criteria), and controls. Patients with macroscopic pulmonary embolisms were excluded. The outcomes studied were the (1) lung blood-volume in areas with different aeration levels (normal, ground glass opacities [GGO], consolidated lung) and (2) aeration/blood-volume ratios.

RESULTS

Included were 20 patients with COVID-19 (10 milds, 10 moderate-severe), six with NC-ARDS, and 12 healthy-controls. Lung aeration was lowest in patients with severe COVID-19 24% (IQR13%-31%) followed by those with NC-ARDS 40%(IQR21%-46%). Blood-volume in GGO was lowest in patients with COVID-19 [moderate-severe:-28.6 (IQR-33.1-23.2); mild: -30.1 (IQR-33.3-23.4)] and highest in normally aerated areas in NC-ARDS -37.4 (IQR-52.5-30.2-) and moderate-severe COVID-19 -33.5(IQR-44.2-28.5). The median aeration/blood-volume ratio was lowest in severe COVID-19 but some values overlapped with those observed among patients with NC-ARDS.

CONCLUSION

Severe COVID-19 disease is associated with low total aerated lung volume and blood-volume in areas with GGO and overall aeration/blood volume ratios, and with high blood volume in normal lung areas. In this hypothesis-generating study, these findings were most pronounced in severe COVID disease. Larger studies are needed to confirm these preliminary findings.

COVID-19 Patients With Pulmonary Hypertension Hospitalized in the United States During the Early Pandemic: Analysis of In-Hospital Mortality, Clinical Outcomes, and Racial Disparities

Coronavirus Disease 2019 (COVID-19) has been linked to severe consequences among hospitalized patients diagnosed with pulmonary hypertension (PH), as evidenced by a limited number of studies. Our retrospective study employed the National Inpatient Sample (NIS) database to evaluate in-hospital mortality and various clinical outcomes in COVID-19 patients with and without PH. This study included all patients ages 18 years and above who were hospitalized in the United States from January 1,2020 to December 31, 2020 with a COVID-19 diagnosis. The patients were then divided into 2 cohorts based on their PH status. After multivariate adjustment, we discovered that COVID-19 patients with PH experienced considerably higher in-hospital mortality, longer hospital stays, and higher costs of hospitalization when compared to COVID-19 patients without PH. Moreover, we observed an increased dependence on invasive and noninvasive positive pressure ventilation among COVID-19 patients with PH, indicating more severe respiratory failure. Our findings suggest that COVID-19 patients with PH had a heightened risk of acute pulmonary embolism and myocardial infarction while hospitalized. Lastly, among COVID-19 patients with PH, Hispanic and Native American patients demonstrated a persistently higher risk of in-hospital mortality compared to other racial groups. To our knowledge, this is the most comprehensive study of outcomes for COVID-19 patients with PH. The observed inpatient mortality appears to be driven by in-hospital complications, particularly pulmonary embolism. Given the substantial mortality and complications associated with COVID-19 and PH, we advocate for SARS-CoV-2 vaccination and the implementation of aggressive nonpharmacological preventive measures.

Anticoagulant treatment and COVID-19 mortality among older adults living in nursing homes in Sweden

Background

Anticoagulants (AC) were introduced in March 2020 as standard of care in nursing home (NH) residents affected with COVID-19 in the Stockholm region, Sweden. ACs are proven to reduce the risk of complications and mortality from COVID-19 among patients of other ages and settings, but there is limited scientific evidence underpinning this practice in the NH setting.

Methods

This matched cohort study included 182 NH residents in the Stockholm Region diagnosed with COVID-19 in March-May 2020. The main exposure was any AC treatment. Exposed (n = 91), 49% prevalent (pre-COVID-19 diagnosis) AC and 51% incident AC were compared with unexposed controls (n = 91). The outcome was 28-days all-cause mortality after COVID-19 infection. The mortality odds ratios (OR) were assessed using logistic regression, adjusted for age, sex, multimorbidity, and mobility, also stratified by incident or prevalent AC-type, age group, and sex.

Results

Of the 182 individuals diagnosed with COVID-19 (median age 88 years, 68% women), 39% died within 28 days after diagnosis. Use of either incident or prevalent AC was associated with a reduced, adjusted 28-day mortality (OR[95% CI]: 0.31[0.16-0.62]). In stratified analyses, the association was significant in both age groups: 70-89 (OR: 0.37 [0.15-0.89]) and 90-99 years of age (OR: 0.22 [0.07-0.65]. In sex-stratified analysis, the AC-lowering effect was significant in women only (OR: 0.28[0.11-0.67]). In the analyses stratified by AC type, the mortality-lowering effect was observed for both prevalent AC (OR: 0.35[0.12-0.99]) and incident AC (OR: 0.29[0.11-0.76]).

Conclusions

Both prevalent and incident use of ACs in prophylactic dosing was associated with reduced 28-day mortality among older individuals with COVID-19 in a NH setting. The effect was seen across age-strata and in women. The findings present new insight in best practice for individuals diagnosed with COVID-19 in the NH setting.

Initial therapeutic anticoagulation with rivaroxaban compared to prophylactic therapy with heparins in moderate to severe COVID-19: results of the COVID-PREVENT randomized controlled trial

BACKGROUND

COVID-19 is associated with a prothrombotic state. Current guidelines recommend prophylactic anticoagulation upon hospitalization.

METHODS

COVID-PREVENT, an open-label, multicenter, randomized, clinical trial enrolled patients (≥ 18 years) with moderate to severe COVID-19 and age-adjusted D-dimers > 1.5 upper limit of normal (ULN). The participants were randomly assigned (1:1) to receive either therapeutic anticoagulation with rivaroxaban 20 mg once daily or thromboprophylaxis with a heparin (SOC) for at least 7 days followed by prophylactic anticoagulation with rivaroxaban 10 mg once daily for 28 days or no thromboprophylaxis. The primary efficacy outcome was the D-dimer level and the co-primary efficacy outcome the 7-category ordinal COVID-19 scale by WHO at 7 days post randomization. The secondary outcome was time to the composite event of either venous or arterial thromboembolism, new myocardial infarction, non-hemorrhagic stroke, all-cause death or progression to intubation and invasive ventilation up to 35 days post randomization.

RESULTS

The primary efficacy outcome D-dimer at 7 days was not different between patients assigned to therapeutic (n = 55) or prophylactic anticoagulation (n = 56) (1.21 mg/L [0.79, 1.86] vs 1.27 mg/L [0.79, 2.04], p = 0.78). In the whole study population D-dimer was significantly lower at 7 days compared to baseline (1.05 mg/L [0.75, 1.48] vs 1.57 mg/L [1.13, 2.19], p < 0.0001). Therapy with rivaroxaban compared to SOC was not associated an improvement on the WHO 7-category ordinal scale at 7 days (p = 0.085). Rivaroxaban improved the clinical outcome measured by the score in patients with a higher baseline D-dimer  > 2.0 ULN (exploratory analysis; 0.632 [0.516, 0.748], p = 0.026). The secondary endpoint occurred in 6 patients (10.9%) in the rivaroxaban group and in 12 (21.4%) in the SOC group (time-to-first occurrence of the components of the secondary outcome: HR 0.5; 95% CI 0.15-1.67; p = 0.264). There was no difference in fatal or non-fatal major or clinically relevant non-major bleeding between the groups.

CONCLUSIONS

Therapeutic anticoagulation with rivaroxaban compared to prophylactic anticoagulation with a heparin did not improve surrogates of clinical outcome in patients with moderate to severe COVID-19. Whether initial rivaroxaban at therapeutic doses might be superior to thromboprophylaxis in patients with COVID-19 and a high risk as defined by D-dimer  > 2 ULN needs confirmation in further studies.

COVID-19 Associated Micro-Anastomotic Thrombosis After Abdominal Free Tissue Transfer: A Case Report and Literature Review

The hypercoagulable state of COVID-19 infection presents a challenge to microsurgeons. While the American Society of Anesthesiologists recommends deferring surgery for 4-10 weeks for COVID-19-infected patients, little else is known regarding how to mitigate thrombotic complications for patients undergoing free tissue transfer. Here, we present a presumed COVID-19-induced hypercoagulable state in a patient undergoing abdominally based free tissue transfer for breast reconstruction as a brief review of the literature to guide clinical decision making.

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.

A Delphi consensus on the management of anticoagulation in the COVID-19 pandemic: the MONACO study

Background

During the COVID-19 pandemic, guideline documents on the management of anticoagulation were rapidly published. However, these documents did not follow a structured methodology, and significant differences existed between the guidelines. The aim of this expert consensus was to provide recommendations on the clinical management of oral anticoagulation in patients in the context of the COVID-19 pandemic.

Methods

A two-round Delphi study was conducted using an online survey. In the first round, panellists expressed their level of agreement with the items on a 9-point Likert scale. Items were selected if they received approval from ≥66.6% of panellists and if they were agreed by the scientific committee. In the second round, panellists revaluated those items that did not meet consensus in the first round.

Results

A total of 147 panellists completed the first round, and 144 of them completed the second round. Consensus was reached on 161 items included in five dimensions. These dimensions addressed: (I) management of anticoagulation in patients with atrial fibrillation (AF) without mechanical valves or moderate/severe mitral stenosis during COVID-19 infection; (II) thromboprophylaxis in patients hospitalised for COVID-19; (III) management of anticoagulation at hospital discharge/after COVID-19; (IV) anticoagulation monitoring in the COVID-19 pandemic setting; and (V) role of telemedicine in the management and follow-up of patients with AF in the COVID-19 pandemic setting.

Conclusions

These areas of collective agreement could specially guide clinicians in making decisions regarding anticoagulation in patients with COVID-19 during hospitalisation and at discharge, where results from clinical trials are still limited and, in some cases, conflicting.

Predictive Model for Mortality in Severe COVID-19 Patients across the Six Pandemic Waves

The impact of SARS-CoV-2 infection remains substantial on a global scale, despite widespread vaccination efforts, early therapeutic interventions, and an enhanced understanding of the disease's underlying mechanisms. At the same time, a significant number of patients continue to develop severe COVID-19, necessitating admission to intensive care units (ICUs). This study aimed to provide evidence concerning the most influential predictors of mortality among critically ill patients with severe COVID-19, employing machine learning (ML) techniques. To accomplish this, we conducted a retrospective multicenter investigation involving 684 patients with severe COVID-19, spanning from 1 June 2020 to 31 March 2023, wherein we scrutinized sociodemographic, clinical, and analytical data. These data were extracted from electronic health records. Out of the six supervised ML methods scrutinized, the extreme gradient boosting (XGB) method exhibited the highest balanced accuracy at 96.61%. The variables that exerted the greatest influence on mortality prediction encompassed ferritin, fibrinogen, D-dimer, platelet count, C-reactive protein (CRP), prothrombin time (PT), invasive mechanical ventilation (IMV), PaFi (PaO2/FiO2), lactate dehydrogenase (LDH), lymphocyte levels, activated partial thromboplastin time (aPTT), body mass index (BMI), creatinine, and age. These findings underscore XGB as a robust candidate for accurately classifying patients with COVID-19.

Intermediate dose enoxaparin in hospitalized patients with moderate-severe COVID-19: a pilot phase II single-arm study, INHIXACOVID19

BACKGROUND

Randomized clinical trials in non-critically ill COVID-19 patients showed that therapeutic-dose heparin increased survival with reduced organ support as compared with usual-care thromboprophylaxis, albeit with increased bleeding risk. The purpose of the study is to assess the safety of intermediate dose enoxaparin in hospitalized patients with moderate to severe COVID-19.

METHODS

A phase II single-arm interventional prospective study including patients receiving intermediate dose enoxaparin once daily according to body weight: 60 mg for 45-60 kg, 80 mg for 61-100 kg or 100 mg for > 100 kg for 14 days, with dose adjustment according to anti-factor Xa activity (target range: 0.4-0.6 UI/ml); an observational cohort (OC) included patients receiving enoxaparin 40 mg day for comparison. Follow-up was 90 days. Primary outcome was major bleeding within 30 and 90 days after treatment onset. Secondary outcome was the composite of all-cause 30 and 90-day mortality rates, disease severity at the end of treatment, intensive care unit (ICU) admission and length of ICU stay, length of hospitalization. All outcomes were adjudicated by an independent committee and analyzed before and after propensity score matching (PSm).

RESULTS

Major bleeding was similar in IC (1/98 1.02%) and in the OC (none), with only one event observed in a patient receiving concomitantly anti-platelet therapy. The composite outcome was observed in 53/98 patients (54%) in the IC and 132/203 (65%) patients in the OC (p = 0.07) before PSm, while it was observed in 50/90 patients (55.6%) in the IC and in 56/90 patients (62.2%) in the OC after PSm (p = 0.45). Length of hospitalization was lower in the IC than in OC [median 13 (IQR 8-16) vs 14 (11-21) days, p = 0.001], however it lost statistical significance after PSm (p = 0.08). At 30 days, two patients had venous thrombosis and two pulmonary embolism in the OC. Time to first negative RT-PCR were similar in the two groups.

CONCLUSIONS

Weight adjusted intermediate dose heparin with anti-FXa monitoring is safe with potential positive impact on clinical course in COVID-19 non-critically ill patients.

TRIAL REGISTRATION

The study INHIXACOVID19 was registred on ClinicalTrials.gov with the trial registration number (TRN) NCT04427098 on 11/06/2020.

D-dimer trends predict COVID-19 patient's prognosis: A retrospective chart review study

This is a retrospective study of patients admitted to Jackson Hospital, Montgomery, Alabama, with a diagnosis of COVID-19 from January 1, 2021, to February 15, 2022. The independent variables used in the models were patient sex, age, race, BMI category, daily D-dimer categories, categories of anticoagulation doses, bleeding episodes, and vaccination status. The three different categories of anticoagulation doses were considered for the purpose of the study which were Enoxaparin 40 mg daily vs Enoxaparin 80 mg daily vs Enoxaparin 1 mg/kg or equivalent daily. The study reviewed a total of 100 hospitalized patients. Intermediate-dose anticoagulation was found to be the optimal dose as only 14% patients died compared to a 36 and 50% death rate among those treated with low-dose and high-dose anticoagulation, respectively. The multivariate linear regression model predicting patient oxygen requirements revealed D-dimer and bleeding status to be statistically significant predictors with a p value of <0.01. For the patients who had a D-dimer value ≥2 µg/mL, the oxygenation requirement was predicted to be 31 L higher than those with a D-dimer <2 µg/mL (99% CI; p < 0.01). When mean D-dimer and corresponding oxygen requirements were calculated per hospitalization days category, the D-dimer levels and oxygen requirements were noted to follow the same trends indicating that both values tended to increase and decrease simultaneously. The study concludes daily D-dimer trends can predict COVID-19 patient survival or daily oxygen requirements indicating that D-dimer can be the miracle molecule for COVID-19 prognosis.

SARS-CoV-2 infection of human lung epithelial cells induces TMPRSS-mediated acute fibrin deposition

Severe COVID-associated lung injury is a major confounding factor of hospitalizations and death with no effective treatments. Here, we describe a non-classical fibrin clotting mechanism mediated by SARS-CoV-2 infected primary lung but not other susceptible epithelial cells. This infection-induced fibrin formation is observed in all variants of SARS-CoV-2 infections, and requires thrombin but is independent of tissue factor and other classical plasma coagulation factors. While prothrombin and fibrinogen levels are elevated in acute COVID BALF samples, fibrin clotting occurs only with the presence of viral infected but not uninfected lung epithelial cells. We suggest a viral-induced coagulation mechanism, in which prothrombin is activated by infection-induced transmembrane serine proteases, such as ST14 and TMPRSS11D, on NHBE cells. Our finding reveals the inefficiency of current plasma targeted anticoagulation therapy and suggests the need to develop a viral-induced ARDS animal model for treating respiratory airways with thrombin inhibitors.

Bleeding Complications in COVID-19 Critically Ill ARDS Patients Receiving VV-ECMO Therapy

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) therapy is rapidly expanding worldwide, yet this therapy has a serious risk of bleeding. Whether coagulation-activating viral infections such as COVID-19 may have an impact on the risk of bleeding is largely unknown. This study conducted a monocentric investigation of severely affected COVID-19 patients receiving VV-ECMO therapy with regard to the occurrence and possible influences of minor and major bleeding and transfusion requirements. Among the 114 included study patients, we were able to assess more than 74,000 h of VV-ECMO therapy. In these, 103 major bleeding events and 2283 minor bleeding events were detected. In total, 1396 red blood concentrates (RBCs) were administered. A statistically significant correlation with the applied anticoagulation or demographic data of the patients was not observed. Contrary to the frequently observed thromboembolic complications among COVID-19 patients, patients with VV-ECMO therapy, even under low-dose anticoagulation, show a distinct bleeding profile, especially of minor bleeding, with a substantial need for blood transfusions. COVID-19 patients show a tendency to have frequent bleeding and require repeated RBC transfusions during VV-ECMO. This fact might not be solely explained by the mechanical alteration of ECMO or anticoagulation.

National Trends in Anticoagulation Therapy for COVID-19 Hospitalized Adults in the United States: Analyses of the National COVID Cohort Collaborative

BACKGROUND

Anticoagulation (AC) utilization patterns and their predictors among hospitalized coronavirus disease 2019 (COVID-19) patients have not been well described.

METHODS

Using the National COVID Cohort Collaborative, we conducted a retrospective cohort study (2020-2022) to assess AC use patterns and identify factors associated with therapeutic AC employing modified Poisson regression.

RESULTS

Among 162 842 hospitalized COVID-19 patients, 64% received AC and 24% received therapeutic AC. Therapeutic AC use declined from 32% in 2020 to 12% in 2022, especially after December 2021. Therapeutic AC predictors included age (relative risk [RR], 1.02; 95% confidence interval [CI], 1.02-1.02 per year), male (RR, 1.29; 95% CI, 1.27-1.32), non-Hispanic black (RR, 1.16; 95% CI, 1.13-1.18), obesity (RR, 1.48; 95% CI, 1.43-1.52), increased length of stay (RR, 1.01; 95% CI, 1.01-1.01 per day), and invasive ventilation (RR, 1.64; 95% CI, 1.59-1.69). Vaccination (RR, 0.88; 95% CI, 84-.92) and higher Charlson Comorbidity Index (CCI) (RR, 0.98; 95% CI, .97-.98) were associated with lower therapeutic AC.

CONCLUSIONS

Overall, two-thirds of hospitalized COVID-19 patients received any AC and a quarter received therapeutic dosing. Therapeutic AC declined after introduction of the Omicron variant. Predictors of therapeutic AC included demographics, obesity, length of stay, invasive ventilation, CCI, and vaccination, suggesting AC decisions driven by clinical factors including COVID-19 severity, bleeding risks, and comorbidities.

A retrospective multicenter cohort study of the association between anti-Factor Xa values and death, thromboembolism, and bleeding in patients with critical COVID-19

BACKGROUND

Patients with critical COVID-19 have a high risk of thromboembolism, but intensified thromboprophylaxis has not been proven beneficial. The activity of low-molecular-weight heparins can be monitored by measuring anti-Factor Xa. We aimed to study the association between anti-Factor Xa values and death, thromboembolism, and bleeding in patients with critical COVID-19.

METHOD

This retrospective cohort study included adult patients with critical COVID-19 admitted to an intensive care unit at three Swedish hospitals between March 2020 and May 2021 with at least one valid peak and/or trough anti-Factor Xa value. Within the peak and trough categories, patients' minimum, median, and maximum values were determined. Logistic regressions with splines were used to assess associations.

RESULTS

In total, 408 patients had at least one valid peak and/or trough anti-Factor Xa measurement, resulting in 153 patients with peak values and 300 patients with trough values. Lower peak values were associated with thromboembolism for patients' minimum (p = 0.01), median (p = 0.005) and maximum (p = 0.001) values. No association was seen between peak values and death or bleeding. Higher trough values were associated with death for median (p = 0.03) and maximum (p = 0.002) values and with both bleeding (p = 0.01) and major bleeding (p = 0.02) for maximum values, but there were no associations with thromboembolism.

CONCLUSIONS

Measuring anti-Factor Xa activity may be relevant for administrating low-molecular-weight heparin to patients with critical COVID-19. Lower peak values were associated with an increased risk of thromboembolism, and higher trough values were associated with an increased risk of death and bleeding. Prospective studies are needed to confirm the results.

TRIAL REGISTRATION

The study was retrospectively registered at Clinicaltrials.gov, NCT05256524, February 24, 2022.

Designing and Implementing "Living and Breathing" Clinical Trials: An Overview and Lessons Learned from the COVID-19 Pandemic

The practice of medicine is characterized by uncertainty, and the findings of randomized clinical trials (RCTs) are meant to help curb that uncertainty. Traditional RCTs, however, have many limitations. To overcome some of these limitations, new trial paradigms rooted in the origins of evidence-based medicine are beginning to disrupt the traditional mold. These new designs recognize uncertainty permeates medical decision making and aim to capitalize on modern health system infrastructure to integrate investigation as a component of care delivery. This article provides an overview of "living, breathing" trials, including current state, anticipated developments, and areas of controversy.

Effects of inflammation on thrombosis and outcomes in COVID-19: secondary analysis of the ATTACC/ACTIV-4a trial

Background

Patients hospitalized for COVID-19 are at high risk of thrombotic complications and organ failure, and often exhibit severe inflammation, which may contribute to hypercoagulability.

Objectives

To determine whether patients hospitalized for COVID-19 experience differing frequencies of thrombotic and organ failure complications and derive variable benefits from therapeutic-dose heparin dependent on the extent of systemic inflammation and whether observed benefit from therapeutic-dose anticoagulation varies depending on the degree of systemic inflammation.

Methods

We analyzed data from 1346 patients hospitalized for COVID-19 enrolled in the ATTACC and ACTIV-4a platforms who were randomized to therapeutic-dose heparin or usual care for whom levels of C-reactive protein (CRP) were reported at baseline.

Results

Increased CRP was associated with worse patient outcomes, including a >98% posterior probability of increased organ support requirement, hospital length of stay, risk of 28-day mortality, and incidence of major thrombotic events or death (patients with CRP 40-100 mg/L or ≥100 mg/L compared to patients with CRP <40 mg/L). Patients with CRP 40 to 100 mg/L experienced the greatest degree of benefit from treatment with therapeutic doses of unfractionated or low molecular weight heparin compared with usual-care prophylactic doses. This was most significant for an increase in organ support-free days (odds ratio: 1.63; 95% confidence interval, 1.09-2.40; 97.9% posterior probability of beneficial effect), with trends toward benefit for other evaluated outcomes.

Conclusion

Moderately ill patients hospitalized for COVID-19 with CRP between 40 mg/L and 100 mg/L derived the greatest benefit from treatment with therapeutic-dose heparin.

Anticoagulation Use as an Independent Predictor of Mortality and Major Adverse Cardiovascular Events in Hospitalized COVID-19 Patients: A Multicenter Retrospective Analysis

Background

Coronavirus disease 2019 (COVID-19) is associated with increased incidence of cardiac arrhythmias and thrombotic events. The adverse cardiovascular outcomes related to ambulatory anticoagulation (AC) therapy in COVID-19 patients are unknown. The goal of this study was to identify the effects of AC use in hospitalized COVID-19 patients.

Methods

This is a multicenter, retrospective study that identified 2,801 hospitalized COVID-19 polymerase chain reaction (PCR)-positive patients admitted between March 2020 and July 2021. Of these, 375 (13.4%) were ambulatory AC users. Data were collected from the electronic health records of hospitalized patients. Mortality included in-hospital death and hospice referral. Major adverse cardiovascular events (MACEs) included acute heart failure (HF), myocardial infarction (MI), myocarditis, pulmonary embolism (PE), deep venous thrombosis (DVT), pericardial effusion, pericarditis, stroke, shock, and cardiac tamponade. A Chi-square test was used to analyze categorical variables, and multivariate logistic regression analysis was performed to account for comorbidities.

Results

AC non-users exhibited a higher incidence of mortality than AC users (13.9% vs. 7.7%, P = 0.001). However, MACE incidence was higher in AC users than AC non-users (44.8% vs. 26.8%, P < 0.001). The higher MACE incidence was driven by higher rates of acute HF (8.3% vs. 2.5%, P < 0.001), MI (26.9% vs. 18.2%, P < 0.001), PE/DVT (16.3% vs. 2.7%, P < 0.001), pericardial effusion (1.6% vs. 0.5%, P = 0.025), and stroke (2.9% vs. 1.2%, P = 0.018). After multivariate logistic regression, MACE incidence remained higher (odds ratio (OR) = 1.61, 95% confidence interval (CI): 1.27 - 2.05, P < 0.001) and all-cause mortality rate lower (OR = 0.34, 95% CI: 0.23 - 0.52, P < 0.001) in AC users.

Conclusions

Ambulatory AC use is associated with increased MACEs but decreased all-cause mortality in patients hospitalized with COVID-19. This study will help physicians identify patients at risk of cardiovascular mortality and direct management based on the identified risk.