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

Comparison of Bayesian and frequentist monitoring boundaries motivated by the Multiplatform Randomized Clinical Trial

BACKGROUND

The coronavirus disease 2019 pandemic highlighted the need to conduct efficient randomized clinical trials with interim monitoring guidelines for efficacy and futility. Several randomized coronavirus disease 2019 trials, including the Multiplatform Randomized Clinical Trial (mpRCT), used Bayesian guidelines with the belief that they would lead to quicker efficacy or futility decisions than traditional "frequentist" guidelines, such as spending functions and conditional power. We explore this belief using an intuitive interpretation of Bayesian methods as translating prior opinion about the treatment effect into imaginary prior data. These imaginary observations are then combined with actual observations from the trial to make conclusions. Using this approach, we show that the Bayesian efficacy boundary used in mpRCT is actually quite similar to the frequentist Pocock boundary.

METHODS

The mpRCT's efficacy monitoring guideline considered stopping if, given the observed data, there was greater than 99% probability that the treatment was effective (odds ratio greater than 1). The mpRCT's futility monitoring guideline considered stopping if, given the observed data, there was greater than 95% probability that the treatment was less than 20% effective (odds ratio less than 1.2). The mpRCT used a normal prior distribution that can be thought of as supplementing the actual patients' data with imaginary patients' data. We explore the effects of varying probability thresholds and the prior-to-actual patient ratio in the mpRCT and compare the resulting Bayesian efficacy monitoring guidelines to the well-known frequentist Pocock and O'Brien-Fleming efficacy guidelines. We also contrast Bayesian futility guidelines with a more traditional 20% conditional power futility guideline.

RESULTS

A Bayesian efficacy and futility monitoring boundary using a neutral, weakly informative prior distribution and a fixed probability threshold at all interim analyses is more aggressive than the commonly used O'Brien-Fleming efficacy boundary coupled with a 20% conditional power threshold for futility. The trade-off is that more aggressive boundaries tend to stop trials earlier, but incur a loss of power. Interestingly, the Bayesian efficacy boundary with 99% probability threshold is very similar to the classic Pocock efficacy boundary.

CONCLUSIONS

In a pandemic where quickly weeding out ineffective treatments and identifying effective treatments is paramount, aggressive monitoring may be preferred to conservative approaches, such as the O'Brien-Fleming boundary. This can be accomplished with either Bayesian or frequentist methods.

A Dynamic, D-dimer-based Thromboprophylaxis Strategy in Patients with COVID-19

Background

COVID-19 pandemics increases venous thromboembolism (VTE) risk during hospitalization, despite prophylactic anticoagulation. Limited radiological diagnosis in pandemic requires a guided protocol for anticoagulant adjustment.

Methods

This retrospective cohort study was conducted at a single center as part of a quality improvement program evaluating the efficacy and safety of anticoagulation protocols. The study focused on implementing a guideline for anticoagulant dosing protocol based on dynamic changes in D-dimer levels in COVID-19 hospitalized patients. The dosing guideline allowed for dose escalation from standard prophylactic levels to escalated prophylactic or therapeutic levels, depending on the patient's risk profile for VTE. The primary endpoints included in-hospital survival comparing between fix and dynamic adjustment treatment groups. Secondary endpoints encompassed major and clinically relevant non-major bleeding (CRNMB) events, incidence of breakthrough thrombosis, length of hospitalization and ICU stay, days of mechanical ventilator use, and survival duration.

Findings

Among the 260 COVID-19-infected patients hospitalized between March 15th and June 15th, 2020. The patients received fixed anticoagulant dosage in 188, 72.3%) patients, while 72 (27.7%) were up-titrated according to the protocol. In-hospital survival at 30 days demonstrated superiority among patients whose anticoagulation was up-titrated to either escalated prophylactic or therapeutic (80.2%) compared to receiving fixed anticoagulant dosage (51.3%) (p=0.01). Bleeding events were significantly higher in up-titrate group (12.5%) compared to fixed anticoagulant dosage group (2.13%). Most of them are CRNMB.

Conclusion

A dynamic, D-dimer-based dose escalation of anticoagulation for hospitalized patients with COVID-19 holds promise in improving in-hospital mortality rates without a significant increase in fatal bleeding events.

Prevalence and risk factors of hospital acquired venous thromboembolism

OBJECTIVES

To investigate the prevalence, clinical characteristics and risk factors of hospital acquired venous thromboembolism (HA-VTE) in a Chinese Hospital.

METHODS

Retrospective analysis of patients diagnosed as HA-VTE in a single institution from January 2016 to December 2022 was performed. Patients with VTE prior to admission or within 48 h after admission were excluded. Demographic data of patients was retrieved from the electronic medical database, and parameters affecting the occurrence of HA-VTE were analyzed.

RESULTS

4,022 patients from 321,997 episodes of medical admissions were diagnosed as VTE. Among these, 952 (23.7%) fulfilled the criteria of HA-VTE, corresponding to an incidence of 0.296%. 76% of patients presented with HA-deep vein thrombosis (DVT) alone, 13% presented with isolated HA-pulmonary embolism (PE), and 11% presented with concomitant HA- DVT and PE. Risk factor analyses showed statistically higher incidence in patients with elder age (67.5 ± 15.5 vs 48.3 ± 17.2 years, p < .001), male gender (0.346% vs 0.262%, p < .001), malignancy (0.513% vs 0.252%, p < .001), trauma (0.659% vs 0.28%, p < .001), emergency admission (0.664% vs 0.186%, p < .001), ICU stay (2.981% vs 0.226%, p < .001), and patients undergoing major surgery (0.702% vs 0.176%, p < .001). Patients with HA-VTE had longer hospital stay (22.5 ± 26.6 vs 7.21 ± 9.23 days, p < .001) and higher mortality rate (8.51% vs 1.01%, p < .001). The crude incidence rate of HA-VTE increased annually from 0.75 per 1,000 patients in 2016 to 5.89 per 1,000 patients in 2022. The subspecialties with the highest incidence rate of HA-VTE were cardiovascular surgery (1.40%), neurosurgery (1.10%), and respiratory medicine (0.72%).

CONCLUSION

This is one of the few large scale studies to show that HA-VTE, accounting for nearly one quarter of all VTE events, occurs in 0.296% of adult hospitalizations. Patients with elder age, malignancy, ICU stay, and undergoing major surgery require more intensive HA-VTE surveillance and prevention.

Lessons Learned from National Heart, Lung, and Blood Institute Covid-19 Clinical Trials

AbstractIn response to the Covid-19 pandemic, the National Heart, Lung, and Blood Institute launched five multisite clinical trials testing candidate host tissue-directed medical interventions to hasten recovery, improve function, and reduce morbidity and mortality. Speed, flexibility, and collaboration were essential. This article from the Steering and Executive committees describes the Collaborating Network of Networks for Evaluating Covid-19 and Therapeutic Strategies (CONNECTS) research program that enrolled 6690 participants and evaluated 18 intervention strategies using 10 molecular agents across the care continuum (outpatient, inpatient, and post discharge), and reports lessons learned from this initiative. Successes include rapid trial execution through collaboration and adaptive platform designs. Challenges that impeded efficiency included time required to execute subcontracts, constraints on clinical research workforce, and limited research infrastructure in nonacademic settings.

D-dimer-An International Assessment of the Quality of Laboratory Testing: Implications for D-dimer Use in the Real World

D-dimer assessment has several established roles in venous thromboembolism (VTE) and disseminated intravascular coagulation diagnosis, and recently the risk stratification of coronavirus disease 2019 (COVID-19). D-dimer assays are neither standardized nor harmonized, use varying methodologies, and use different reporting units, all resulting in a lack of interchangeability and generalizability of assays. Using large multiyear datasets from an international laboratory quality assurance program, we assessed (1) common D-dimer assays in use worldwide, (2) differences in analytical performance between different methods, and (3) interlaboratory variability between positive samples. External proficiency testing results from laboratories participating in the External Quality Control for Assays and Tests (ECAT) Foundation were analyzed from 2017 to 2023. Annually, between 578 and 690 laboratories participated in the D-dimer sample surveys with response rates ranging from 88 to 97%. The three most common assays in use in 2023 were the Siemens Innovance D-dimer (42%), the IL HemosIL D-dimer HS 500 (20%), and the Diagnostica Stago (Stago) Liatest D-dimer Plus (10%)-all these are automated, quantitative, latex immunoassays expressed in fibrinogen equivalent units (FEU). The highest interlaboratory variability was observed around the typical VTE exclusion threshold of 0.5 mg/L FEU. Lower interlaboratory variability was observed at values above 0.8 mg/L FEU. Our study provides recent, international performance data on currently used D-dimer assays and describes the significant variability between assays and across D-dimer concentrations. We demonstrate that assays are not interchangeable and that using them interchangeably has the potential to result in clinically important errors. There is an urgent need to educate users about these issues and to work towards harmonizing D-dimer units and reporting.

Mechanisms of long COVID and the path toward therapeutics

Long COVID, a type of post-acute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (PASC) defined by medically unexplained symptoms following infection with SARS-CoV-2, is a newly recognized infection-associated chronic condition that causes disability in some people. Substantial progress has been made in defining its epidemiology, biology, and pathophysiology. However, there is no cure for the tens of millions of people believed to be experiencing long COVID, and industry engagement in developing therapeutics has been limited. Here, we review the current state of knowledge regarding the biology and pathophysiology of long COVID, focusing on how the proposed mechanisms explain the physiology of the syndrome and how they provide a rationale for the implementation of a broad experimental medicine and clinical trials agenda. Progress toward preventing and curing long COVID and other infection-associated chronic conditions will require deep and sustained investment by funders and industry.

National Institutes of Health COVID-19 Treatment Guidelines Panel: Perspectives and Lessons Learned

DESCRIPTION

In March 2020, the White House Coronavirus Task Force determined that clinicians in the United States needed expert treatment guidelines to optimally manage patients with COVID-19, a potentially life-threatening disease caused by a new pathogen for which no specific treatments were known to be effective.

METHODS

The U.S. Department of Health and Human Services requested that the National Institutes of Health (NIH) take the lead in expeditiously convening a panel of experts to create "living" guidelines that would be widely accessible and capable of frequent updating as important new information became available.

RECOMMENDATIONS

The purpose of this article is to expand on the experiences of the NIH COVID-19 Treatment Guidelines Panel (the Panel) over the past 4 years, summarize the Panel's final recommendations for COVID-19, highlight some challenges and unanswered questions about COVID-19 management, and inform future responses to public health emergencies. The Panel was formed in March 2020, and the first iteration of the guidelines was released in April 2020. Now that the public health emergency has ended, the NIH COVID-19 Treatment Guidelines have sunsetted. This role will now fall to professional societies and organizations, such as the American College of Physicians, the Infectious Diseases Society of America, the Pediatric Infectious Diseases Society, and the World Health Organization, all of which have been active in this area.

Effect of sodium-glucose co-transporter-2 inhibitors on survival free of organ support in patients hospitalised for COVID-19 (ACTIV-4a): a pragmatic, multicentre, open-label, randomised, controlled, platform trial

BACKGROUND

Patients hospitalised for COVID-19 are at risk for multiorgan failure and death. Sodium-glucose co-transporter-2 (SGLT2) inhibitors provide cardiovascular and kidney protection in patients with cardiometabolic conditions and could provide organ protection during COVID-19. We aimed to investigate whether SGLT2 inhibitors can reduce the need for organ support in patients hospitalised for COVID-19.

METHODS

This pragmatic, multicentre, open-label, randomised, controlled, platform trial was conducted across 63 sites in the USA, Spain, Brazil, Italy, and Mexico. Patients aged at least 18 years hospitalised for COVID-19 (moderate or severe illness) were randomly assigned (1:1), via an interactive voice system or web-response system, to receive locally available SGLT2 inhibitor (administered orally, once daily) plus standard-of-care or standard-of-care for 30 days. The primary outcome was organ support-free days evaluated through 21 days, assessed using intention-to-treat approach. This trial is registered on ClinicalTrials.gov, NCT04505774.

FINDINGS

The first patient was randomly assigned to the SGLT2 inhibitor domain on Dec 3, 2021. On March 31, 2023, at the recommendation of the data and safety monitoring board, enrolment in the SGLT2 inhibitor domain for both moderately and severely ill hospitalised patients was stopped prematurely for futility due to a low likelihood of finding a treatment benefit. The final randomised population consisted of 575 patients (mean age 72 years [SD 13], 242 (42%) female and 154 (27%) Hispanic; 504 in the moderate illness group and 71 in the severe illness group). 573 patients had a known 21-day outcome; 215 (75%) of 285 patients in the SGLT2 inhibitor plus standard-of-care group did not require respiratory or cardiovascular organ support versus 231 (80%) of 288 patients in the standard-of-care group. The adjusted odds ratio (OR) for an SGLT2 inhibitor effect on organ support-free days was 0·74 (95% Credible Interval [CrI] 0·48-1·13; where OR higher than 1 indicated treatment benefit, yielding a posterior probability of futility P(OR <1·2) of 99% and a posterior probability of inferiority P(OR<1·0) of 91%). There were 37 deaths (13%) in the SGLT2 inhibitor plus standard-of-care group and 42 deaths (15%) in the standard-of-care group at 90 days (hazard ratio 0·91 [95% CrI 0·58-1·43], probability of hazard ratio <1 of 66%). No safety concerns were observed with SGLT2 inhibitors, including no cases of ketoacidosis.

INTERPRETATION

SGLT2 inhibitors did not significantly increase days free of organ support or reduce mortality in patients hospitalised with COVID-19. SGLT2 inhibitors were well tolerated with no observed safety concerns. Overall, these findings do not support the use of SGLT2 inhibitors as standard care in patients hospitalised with COVID-19.

FUNDING

National Institutes of Health.

What are the clinical and research lessons learned from immunomodulators and other therapies during the COVID-19 pandemic?

PURPOSE OF REVIEW

The development and use of immunomodulators and other therapies during the coronavirus disease 2019 (COVID-19) pandemic provided several lessons with respect to these therapies, and to how medical researchers and clinicians should approach the next pandemic.

RECENT FINDINGS

New or repurposed therapies, particularly immunomodulator treatments, for the treatment of an infectious disease will always be associated with inherent patient risk and this was the case during the COVID-19 pandemic. The concomitant development and use of effective antimicrobial therapies along with close monitoring for secondary infections is paramount for patient safety and treatment success. The development of immunomodulators and other therapies during the COVID-19 pandemic further highlighted the importance of maintaining high standards for medical research for all potential treatment with large double-blind placebo-controlled trials and peer review being the best mode of disseminating medical results rather than social media outlets.

SUMMARY

The next new and emerging pandemic will undoubtedly share many of the same challenges posed by COVID-19. It is important that researchers and clinicians learn from this experience, adhere to tried and true clinical care, all the while conducting high quality research aimed at developing definitive treatments.

The first five years of SARS-CoV-2: inpatient treatment updates and future directions

INTRODUCTION

In December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first identified in adults with pneumonia in Wuhan, China.

AREAS COVERED

It is now believed that several billion humans have been infected with SARS-CoV-2 and more than ten million have died from coronavirus disease 2019 (COVID-19), the disease caused by SARS-CoV-2.

EXPERT OPINION

The first five years of the SARS-CoV-2 pandemic have been marked by unfathomable suffering as well as remarkable scientific progress. This manuscript examines what has been learned about the treatment of inpatients with COVID-19 and explores how the therapeutic approach may evolve in the years ahead.

Statistical Power and Performance of Strategies to Analyze Composites of Survival and Duration of Ventilation in Clinical Trials

BACKGROUND

Patients with acute hypoxemic respiratory failure are at high risk of death and prolonged time on the ventilator. Interventions often aim to reduce both mortality and time on the ventilator. Many methods have been proposed for analyzing these endpoints as a single composite outcome (days alive and free of ventilation), but it is unclear which analytical method provides the best performance. Thus, we aimed to determine the analysis method with the highest statistical power for use in clinical trials.

METHODS

Using statistical simulation, we compared multiple methods for analyzing days alive and free of ventilation: the t, Wilcoxon rank-sum, and Kryger Jensen and Lange tests, as well as the proportional odds, hurdle-Poisson, and competing risk models. We compared 14 scenarios relating to: 1) varying baseline distributions of mortality and duration of ventilation, which were based on data from a registry of patients with acute hypoxemic respiratory failure and 2) the varying effects of treatment on mortality and duration of ventilation.

RESULTS AND CONCLUSIONS

All methods have good control of type 1 error rates (i.e., avoid false positive findings). When data are simulated using a proportional odds model, the t test and ordinal models have the highest relative power (92% and 90%, respectively), followed by competing risk models. When the data are simulated using survival models, the competing risk models have the highest power (100% and 92%), followed by the t test and a ten-category ordinal model. All models struggled to detect the effect of the intervention when the treatment only affected one of mortality and duration of ventilation. Overall, the best performing analytical strategy depends on the respective effects of treatment on survival and duration of ventilation and the underlying distribution of the outcomes. The evaluated models each provide a different interpretation for the treatment effect, which must be considered alongside the statistical power when selecting analysis models.

Incidence of deep venous thrombosis in COVID-19 critically ill patients treated with intermediate-dose of heparin for thromboprophylaxis: The COVIDOP-DVT observational study

INTRODUCTION

The high prevalence of deep vein thrombosis (DVT) in patients admitted to intensive care unit (ICU) for COVID-19-related acute respiratory distress syndrome (ARDS) would justify systematic screening of these patients or higher therapeutic dose of heparin for thromboprophylaxis.

MATERIAL AND METHOD

We performed a systematic echo-Doppler of the lower limb proximal veins during the first 48 h (visit 1) and from 7 to 9 days after visit 1 (visit 2) in consecutive patients admitted to the ICU of a university-affiliated tertiary hospital for severe proven COVID-19 during the second wave. All patients received intermediate-dose heparin (IDH). The primary objective was to determine DVT incidence on venous Doppler ultrasound. Secondary objectives were to determine whether the presence of DVT modifies the anticoagulation regimen, the incidence of major bleeding according to International Society on Thrombosis and Haemostasis (ISTH) criteria, and the mortality rate of patients with and without DVT.

RESULTS

We included 48 patients (30 [62.5%] men) with a median age of 63 years [IQR, 54-70]. The prevalence of proximal deep vein thrombosis was 4.2% (2/48). In these two patients, after DVT diagnosis, anticoagulation was changed from intermediate to curative dose. Two patients (4.2%) had a major bleeding complication according to ISTH criteria. Among the 48 patients, 9 (18.8%) died before hospital discharge. No DVT or pulmonary embolism was diagnosed in these deceased patients during their hospital stay.

CONCLUSION

In critically ill patients with COVID-19, management with IDH results in a low incidence of DVT. Although our study is not designed to demonstrate any difference in outcome, our results do not suggest any signal of harm when using intermediate-dose heparin (IDH) COVID-19 with a frequency of major bleeding complications less than 5%.

Effect of amubarvimab-romlusevimab for treatment of severe COVID-19 in intensive care units: A retrospective cohort study

Amubarvimab-romlusevimab is a commonly recommended antiviral treatment in China for adult patients with mild or moderate SARS-CoV-2 infections, especially for patients with a high risk factor for progression to severe COVID-19. However, its exact efficacy in patients with severe Covid-19 is not yet known.This is a single-center retrospective cohort study, in which we collected the general data, laboratory tests, radiological characteristics, viral conversion status, and prognosis of the disease from patients with COVID-19 hospitalized, from December 2022 to March 2023 in the Department of Critical Care Medicine. The amubarvimab-romlusevimab therapy can reduce the 28-day mortality (29.79 % vs 51.35 %, p = 0.02), and ICU mortality (29.79 % vs 55.41 %, p = 0.006) of severe COVID-19.A 1:1 PSM (Propensity Score Matching) was performed to reduce bias, in order to ensure the two groups were balanced and comparable. In the matched population (n = 47), there were no statistically significant differences between the mAbs (monoclonal antibody)group and the Non-antiviral group in 28-day, and thromboembolic events in COVID-19 patients. The 40-day survival analysis shows that mAbs therapy can improve patient prognosis (HR = 0.45, 95%CI = 0.26-0.76, p = 0.008). However, no significant intergroup difference in the 40-day cumulative viral conversion rate. In a univariate Cox regression analysis, The Amubarvimab - romlusevimab therapy(HR:0.464; CI:[0.252-0.853]; p:0.013) is a protective factor and CRP, PCT, PLT, Lactate, PT, PT-INR, and pt% level at admission were risk factors for clinical prognosis. After including the above covariates, Multifactorial COX regression shows that the Amubarvimab - romlusevimab therapy(HR:0.392; CI:[0.211-0.729]; p:0.003), CRP, Lactate and PT-INR at admission are independent factors for mortality of severe COVID-19. Based on the current data, we conclude that amubarvimab-romlusevimab therapy is beneficial for patients with severe COVID-19.

Using real-world data to accelerate the search for long COVID therapies

Long COVID, a spectrum of symptoms and syndromes that can develop after SARS-COV-2 infection, can significantly affect patients' health, quality of life and impact their ability to productively function in society. There is currently no approved therapy for Long COVID and there is an urgent need for rigorous clinical trials to find such treatments. Although research into the pathophysiology of Long COVID is advancing, investigations into treatment for patients remain underfunded and, as a result, understudied. Owing to the urgency of the Long COVID pandemic and as a research collaborative across a diversity of biomedical innovation value propositions, we are calling for a new approach that parallelizes pathophysiologic and therapeutic research into this condition, leveraging patient-centered research and real-world data to generate hypotheses to assess the effectiveness of existing FDA approved drugs. Accelerated discovery of therapeutics for Long COVID can then be confirmed through efficient and cost-effective adaptive platform clinical trials.

Bayesian statistics for clinical research

Frequentist and Bayesian statistics represent two differing paradigms for the analysis of data. Frequentism became the dominant mode of statistical thinking in medical practice during the 20th century. The advent of modern computing has made Bayesian analysis increasingly accessible, enabling growing use of Bayesian methods in a range of disciplines, including medical research. Rather than conceiving of probability as the expected frequency of an event (purported to be measurable and objective), Bayesian thinking conceives of probability as a measure of strength of belief (an explicitly subjective concept). Bayesian analysis combines previous information (represented by a mathematical probability distribution, the prior) with information from the study (the likelihood function) to generate an updated probability distribution (the posterior) representing the information available for clinical decision making. Owing to its fundamentally different conception of probability, Bayesian statistics offers an intuitive, flexible, and informative approach that facilitates the design, analysis, and interpretation of clinical trials. In this Review, we provide a brief account of the philosophical and methodological differences between Bayesian and frequentist approaches and survey the use of Bayesian methods for the design and analysis of clinical research.

Guidelines on deep vein thrombosis of the Brazilian Society of Angiology and Vascular Surgery

Deep vein thrombosis is one of the main causes of inpatient and outpatient morbidity, both in medical and surgical patients, significantly impacting mortality statistics and requiring prompt diagnosis so that treatment can be initiated immediately. This document was prepared and reviewed by 11 specialists certified by the Brazilian Society of Angiology and Vascular Surgery, who searched the main databases for the best evidence on the diagnostic (physical examination, imaging) and therapeutic approaches (heparin, coumarins, direct oral anticoagulants, fibrinolytics) to the disease.

Understanding the Evolving Pathophysiology of Coronavirus Disease 2019 and Adult Nursing Management

Coronavirus disease 2019 (COVID-19) was first identified in December 2019 and quickly became a global pandemic. The understanding of the pathophysiology, treatment, and management of the disease has evolved since the beginning of the pandemic in 2020. COVID-19 can be complicated by immune system dysfunction, lung injury with hypoxemia, acute kidney injury, and coagulopathy. The treatment and management of COVID-19 is based on the severity of illness, ranging from asymptomatic to severe and often life-threatening disease. The 3 main recommended medication classes include antivirals, immunomodulators, and anticoagulants. Other supportive therapies include ensuring adequate oxygenation, mechanical ventilation, and prone positioning.

Efficacy of unfractionated heparin in patients with moderate sepsis-induced coagulopathy: An observational study

INTRODUCTION

The 2021 Surviving Sepsis Campaign guidelines recommend low-molecular-weight heparin for the prevention of venous thromboembolism in sepsis. However, observational studies suggest that anticoagulants as a whole may benefit severely ill sepsis patients with coagulopathy, but the optimal targets of unfractionated heparin remain unclear. This study investigated which sepsis patients could most benefit from unfractionated heparin.

MATERIALS AND METHODS

In this retrospective observational study, we identified adult sepsis patients requiring urgent hospitalization from 2006 to 2019 using a large-scale Japanese medical database. Patients were divided into two groups: those receiving unfractionated heparin within 72 h of admission and those who did not. We compared in-hospital mortality, major bleeding complications, and thromboembolic events between these groups using a multivariate logistic regression model adjusted for patient and treatment variables. Additionally, we assessed the association between heparin administration and in-hospital mortality across various subgroups.

RESULTS

Among 30,342 sepsis patients, 2520 received early heparin administration, and 27,822 did not. Multivariate logistic regression revealed a significant association between heparin and reduced in-hospital mortality (adjusted OR: 0.735, 95 % CI: 0.596-0.903) but no significant association with major bleeding and thromboembolic risk (adjusted OR: 1.137, 1.243; 95 % CI: 0.926-1.391, 0.853-1.788, respectively). Subgroup analyses suggested significant survival benefits associated with heparin only in the sepsis patients with moderate coagulopathy and sepsis-induced coagulopathy scores of 3 or 4 (adjusted OR: 0.452, 0.625; 95 % CI: 0.265-0.751, 0.410-0.940, respectively).

CONCLUSIONS

Early heparin administration upon admission is associated with lower in-hospital mortality, especially in moderate sepsis-induced coagulopathy, and no significant increase in complications.

The Preventive and Therapeutic Effects of Acute and Severe Inflammatory Disorders with Heparin and Heparinoid

Systematic inflammatory response syndrome (SIRS) and the accompanying sepsis pose a huge threat to human health worldwide. Heparin is a part of the standard supportive care for the disease. However, the molecular mechanism is not fully understood yet, and the potential signaling pathways that play key roles have not yet been elucidated. In this paper, the main findings regarding the molecular mechanisms associated with the beneficial effects of heparin, including inhibiting HMGB-1-driven inflammation reactions, histone-induced toxicity, thrombo-inflammatory response control and the new emerging mechanisms are concluded. To set up the link between the preclinical research and the clinical effects, the outcomes of the clinical trials are summarized. Then, the structure and function relationship of heparin is discussed. By providing an updated analysis of the above results, the paper highlights the feasibility of heparin as a possible alternative for sepsis prophylaxis and therapy.

The COVID-19 thrombus: distinguishing pathological, mechanistic, and phenotypic features and management

A heightened risk for thrombosis is a hallmark of COVID-19. Expansive clinical experience and medical literature have characterized small (micro) and large (macro) vessel involvement of the venous and arterial circulatory systems. Most events occur in patients with serious or critical illness in the hyperacute (first 1-2 weeks) or acute phases (2-4 weeks) of SARS-CoV-2 infection. However, thrombosis involving the venous, arterial, and microcirculatory systems has been reported in the subacute (4-8 weeks), convalescent (> 8-12 weeks) and chronic phases (> 12 weeks) among patients with mild-to-moderate illness. The purpose of the current focused review is to highlight the distinguishing clinical features, pathological components, and potential mechanisms of venous, arterial, and microvascular thrombosis in patients with COVID-19. The overarching objective is to better understand the proclivity for thrombosis, laying a solid foundation for screening and surveillance modalities, preventive strategies, and optimal patient management.

Diagnostic potential of blood plasma longitudinal viscosity measured using Brillouin light scattering

Blood plasma viscosity (PV) is an established biomarker for numerous diseases. Measurement of the shear PV using conventional rheological techniques is, however, time consuming and requires significant plasma volumes. Here, we show that Brillouin light scattering (BLS) and angle-resolved spectroscopy measurements of the longitudinal PV from microliter-sized plasma volumes can serve as a proxy for the shear PV measured using conventional viscometers. This is not trivial given the distinct frequency regime probed and the longitudinal viscosity, a combination of the shear and bulk viscosity, representing a unique material property on account of the latter. We demonstrate this for plasma from healthy persons and patients suffering from different severities of COVID-19 (CoV), which has been associated with an increased shear PV. We further show that the additional information contained in the BLS-measured effective longitudinal PV and its temperature scaling can provide unique insight into the chemical constituents and physical properties of plasma that can be of diagnostic value. In particular, we find that changes in the effective longitudinal viscosity are consistent with an increased suspension concentration in CoV patient samples at elevated temperatures that is correlated with disease severity and progression. This is supported by results from rapid BLS spatial-mapping, angle-resolved BLS measurements, changes in the elastic scattering, and anomalies in the temperature scaling of the shear viscosity. Finally, we introduce a compact BLS probe to rapidly perform measurements in plastic transport tubes. Our results open a broad avenue for PV diagnostics based on the high-frequency effective longitudinal PV and show that BLS can provide a means for its implementation.

Step-Based Dosing of Anticoagulants in COVID-19 Treatment

BACKGROUND

Step-based dosing of anticoagulants has been widely implemented for the treatment of coronavirus disease 2019 (COVID-19), but no studies have comprehensively evaluated the effectiveness and safety of this approach. We aimed to investigate whether step-based dosing of anticoagulants was associated with clinical outcomes in patients with COVID-19 compared with standard prophylactic dosing.

METHOD

We conducted a retrospective cohort study on adults hospitalized with moderate-to-severe COVID-19. The exposure was step-based dosing of anticoagulants, including prophylactic anticoagulants (PrA), prophylactic-switching-to-therapeutic anticoagulants (Pr-to-ThA), therapeutic anticoagulants (ThA), and therapeutic-switching-to-prophylactic anticoagulants (Th-to-PrA). The primary effectiveness outcome was a composite of all-cause mortality, admission to an intensive care unit (ICU admission), stroke, and venous thromboembolism (VTE). The primary safety outcome was a composite of major and minor/clinically relevant non-major (CRNM) bleeding.

RESULTS

Among 1,081 records for analysis (mean age 59.9, 49.9% being female), during a median follow-up of 15 days, the primary effectiveness outcome occurred in 333 patients (33.5% in the PrA group, 24.6% in the Pr-to-ThA group, 23.7% in the Th-to-PrA group, and 38.0% in the ThA group). Compared with the PrA group, patients receiving Pr-to-ThA had a lower risk of the primary effectiveness outcome (adjusted odds ratio (OR) 0.64, 95% CI: 0.45 to 0.90, Dunnett-adjusted p = 0.01), while those in the Th-to-PrA and ThA were more likely to experience the primary safety outcome (Th-to-PrA, aOR = 3.00, 95% CI: 1.53 to 5.89; ThA, aOR = 3.05, 95% CI: 1.61 to 5.79).

CONCLUSION

In adults hospitalized with moderate-to-severe COVID-19, compared with standard PrA, the step-based dose-increasing therapy was associated with a lower composite risk of all-cause mortality, ICU admission, stroke, or VTE without evidence of a higher risk of bleeding. ThA dosing was associated with an increase in the bleeding risk, primarily minor and CRNM bleeding.

Predictors of bleeding and thrombotic events among patients admitted to the hospital with COVID-19 and elevated D-dimer: insights from the ACTION randomized clinical trial

Therapeutic anticoagulation showed inconsistent results in hospitalized patients with COVID-19 and selection of the best patients to use this strategy still a challenge balancing the risk of thrombotic and hemorrhagic outcomes. The present post-hoc analysis of the ACTION trial evaluated the variables independently associated with both bleeding events (major bleeding or clinically relevant non-major bleeding) and the composite outcomes thrombotic events (venous thromboembolism, myocardial infarction, stroke, systemic embolism, or major adverse limb events). Variables were assessed one by one with independent logistic regressions and final models were chosen based on Akaike information criteria. The model for bleeding events showed an area under the curve of 0.63 (95% confidence interval [CI] 0.53 to 0.73), while the model for thrombotic events had an area under the curve of 0.72 (95% CI 0.65 to 0.79). Non-invasive respiratory support was associated with thrombotic but not bleeding events, while invasive ventilation was associated with both outcomes (Odds Ratio of 7.03 [95 CI% 1.95 to 25.18] for thrombotic and 3.14 [95% CI 1.11 to 8.84] for bleeding events). Beyond respiratory support, creatinine level (Odds Ratio [OR] 1.01 95% CI 1.00 to 1.02 for every 1.0 mg/dL) and history of coronary disease (OR 3.67; 95% CI 1.32 to 10.29) were also independently associated to the risk of thrombotic events. Non-invasive respiratory support, history of coronary disease, and creatinine level may help to identify hospitalized COVID-19 patients at higher risk of thrombotic complications.ClinicalTrials.gov: NCT04394377.

Exploration of alive-and-ventilator free days as an outcome measure for clinical trials of Resuscitative interventions

BACKGROUND

Outcome selection is a critically important aspect of clinical trial design. Alive-and-ventilator free days is an outcome measure commonly used in critical care clinical trials, but has not been fully explored in resuscitation science.

METHODS

A simulation study was performed to explore approaches to the definition and analysis of alive-and-ventilator free days in cardiac arrest populations. Data from an in-hospital cardiac arrest observational cohort and from the Pragmatic Airway Resuscitation Trial were used to inform and conduct the simulations and validate approaches to alive-and-ventilator free days measurement and analysis.

FINDINGS

Alive-and-ventilator-free days is a flexible outcome measure in cardiac arrest populations. An approach to alive-and-ventilator free days that assigns -1 days when return of spontaneous circulation is not achieved provides a wider distribution of the outcome and improves statistical power. The optimal approach to the analysis of alive-and-ventilator free days varies based on the expected impact of the intervention under study on rates of return of spontaneous circulation, survival, and ventilator-free survival.

CONCLUSIONS

Alive-and-ventilator free days adds to the armamentarium of clinical trialists in the field of resuscitation science.

COVID-19 Coagulopathy

Coronavirus disease of 2019 (COVID-19) is the respiratory viral infection caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Despite being a primary respiratory illness, it is commonly complicated by systemic involvement of the vasculature leading to arterial and venous thrombosis. In this review, we will focus on the association between COVID-19 and thrombosis. We will highlight the pathophysiology of COVID-19 coagulopathy. The clinical manifestations of COVID-19 vasculopathy will be discussed with a focus on venous and arterial thromboembolic events. COVID-19 vasculopathy and disseminated intravascular coagulation (DIC) are distinguished within, as well as areas of controversy, such as "long COVID". Finally, the current professional guidelines on prevention and treatment of thrombosis associated with SARS-CoV-2 infection will be discussed.

Anti-Xa activity below range is related to thrombosis in patients with severe COVID-19

OBJECTIVE

We aimed to anlayse the relationship between anti-Xa activity below range and thomboembolic events.

DESIGN

Single center prospective observational longitudinal cohort study (February-November 2021).

SETTING

Patients admitted to the ICU of a University Hospital.

PARTICIPANTS

Patients with severe COVID-19 pneumoniae.

INTERVENTIONS

Enoxaparin was used for prophylactic and therapeutic anticoagulation. Enoxaparin dosing and dose adjustment were based on anti-Xa activity according to the hospital protocol.

MAIN VARIABLES OF INTEREST

Target: thomboembolic events.

PREDICTORS

demographics, pharmacotherapy, anti-Xa measurements, clinical data, and laboratory results. Logistic regression was used to identify independent risk factors for thomboembolic events.

RESULTS

Data were available for 896 serum anti-Xa measurements from 228 subjects. Overall, 71.9% were male, with a median age of 62. Most patients needed invasive mechanical ventilation (87.7%) and mortality was 24.1%. A total of 28.9% new thomboembolic events were diagnosed. There were 27.1% anti-Xa measesurements below range. When multivariable logistic regression analysis was performed anti-Xa activity below range (RR, 4.2; p = 0.000), C-reactive protein (25 mg/L increase) (RR, 1.14; p = 0.005) and D-dimer (1000 ng/L increase) (RR, 1.06; p = 0.002) were the independent factors related to new thomboembolic events in patients with severe COVID-19.

CONCLUSIONS

Anti-Xa activity below range, C-reactive protein and D-dimer were the independent factors related to thomboembolic events in patients with severe COVID-19. Purposely designed clinical trials should be carried out to confirm the benefit of an anti-Xa monitoring.

The association of antiplatelet agents with mortality among patients with non-COVID-19 community-acquired pneumonia: a systematic review and meta-analysis

Background

Community-acquired pneumonia (CAP) triggers inflammatory and thrombotic host responses driving morbidity and mortality. Antiplatelet agents may favorably modulate these pathways; however, their role in non-COVID-19 CAP remains uncertain.

Objectives

To evaluate the association of antiplatelet agents with mortality in hospitalized patients with non-COVID-19 CAP.

Methods

We conducted a systematic review and meta-analysis of observational studies and randomized controlled trials (RCTs) of adult patients hospitalized for non-COVID-19 CAP exposed to antiplatelet agents (acetylsalicylic acid or P2Y12 inhibitors). We searched MEDLINE, Embase, and CENTRAL from inception to August 2023. Our primary outcome was all-cause mortality: meta-analyzed (random-effects models) separately for observational studies and RCTs. For observational studies, we used adjusted mortality estimates.

Results

We included 13 observational studies (123,012 patients; 6 reported adjusted mortality estimates) and 2 RCTs (225 patients; both high risk of bias). In observational studies reporting hazard ratio, antiplatelet agents were associated with lower mortality (hazard ratio, 0.65; 95% CI, 0.46-0.91; I 2  = 85%; 4 studies, 91,430 patients). In studies reporting adjusted odds ratio, antiplatelet agent exposure was associated with reduced odds of mortality (odds ratio, 0.67; 95% CI, 0.45-1.00; I 2  = 0%; 2 studies, 24,889 patients). Among RCTs, there was a nonsignificant association with mortality (risk ratio, 0.66; 95% CI, 0.20-2.25; I 2  = 54%; 2 studies, 225 patients). By the Grading of Recommendations, Assessment, Development, and Evaluation criteria, the certainty of the evidence was low, primarily due to risk of bias.

Conclusion

In hospitalized patients with non-COVID-19 CAP, antiplatelet agents may be associated with reduced mortality compared with usual care or placebo, but the certainty of evidence is low.

Extreme γ' fibrinogen levels in COVID-19 patients

COVID-19 disease progression can be accompanied by a "cytokine storm" that leads to secondary sequelae such as acute respiratory distress syndrome. Several inflammatory cytokines have been associated with COVID-19 disease progression, but have high daily intra-individual variability. In contrast, we have shown that the inflammatory biomarker γ' fibrinogen (GPF) has a 6-fold lower coefficient of variability compared to other inflammatory markers such as hs-CRP. The aims of the study were to measure GPF in serial blood samples from COVID-19 patients at a tertiary care medical center in order to investigate its association with clinical measures of disease progression. COVID-19 patients were retrospectively enrolled between 3/16/2020 and 8/1/2020. GPF was measured using a commercial ELISA. We found that COVID-19 patients can develop extraordinarily high levels of GPF. Our results showed that ten out of the eighteen patients with COVID-19 had the highest levels of GPF ever recorded. The previous highest GPF level of 80.3 mg/dL was found in a study of 10,601 participants in the ARIC study. GPF levels were significantly associated with the need for ECMO and mortality. These findings have potential implications regarding prophylactic anticoagulation of COVID-19 patients.

Clinician Prediction of Survival vs Calculated Prediction Scores in Patients Requiring Extracorporeal Membrane Oxygenation

BACKGROUND

Determining appropriate extracorporeal membrane oxygenation (ECMO) candidacy ensures appropriate utilization of this costly resource. The current ECMO survival prediction scores do not consider clinician assessment of patient viability. This study compared clinician prediction of survival to hospital discharge versus prediction scores.

OBJECTIVES

The aim of this study was to compare clinician prediction of patients' survival to hospital discharge versus prognostic prediction scores (Respiratory ECMO Survival Prediction [RESP] or Survival After Veno-Arterial ECMO [SAVE] score) to actual survival.

METHODS

This was an observational descriptive study from January 2020 to November 2021 conducted with interviews of nurses, perfusionists, and physicians who were involved during the initiation of ECMO within the first 24 hours of cannulation. Data were retrieved from the medical record to determine prediction scores and survival outcomes at hospital discharge. Accuracy of clinician prediction of survival was compared to the RESP or SAVE prediction scores and actual survival to hospital discharge.

RESULTS

Accurate prediction of survival to hospital discharge for veno-venous ECMO by nurses was 47%, 64% by perfusionists, 45% by physicians, and 45% by the RESP score. Accurate predictions of patients on veno-arterial ECMO were correct in 54% of nurses, 77% of physicians, and 14% by the SAVE score. Physicians were more accurate than the SAVE score, P = .021, and perfusionists were significantly more accurate than the RESP score, P = .044. There was no relationship between ECMO specialists' years of experience and accuracy of predications.

CONCLUSION

Extracorporeal membrane oxygenation clinicians may have better predictions of survival to hospital discharge than the prediction scores. Further research is needed to develop accurate prediction tools to help determine ECMO eligibility.

Critical Illness Outside the Intensive Care Unit: Research Challenges in Emergency and Prehospital Settings

Patients with acute critical illness require prompt interventions, yet high-quality evidence supporting many investigations and treatments is lacking. Clinical research in this setting is challenging due to the need for immediate treatment and the inability of patients to provide informed consent. Attempts to obtain consent from surrogate decision-makers can be intrusive and lead to unacceptable delays to treatment. These problems may be overcome by pragmatic approaches to study design and the use of supervised waivers of consent, which is ethical and appropriate in situations where there is high risk of poor outcome and a paucity of proven effective treatment.

The response of Canada's clinical health research ecosystem to the COVID-19 pandemic

BACKGROUND

The response of Canada's research community to the COVID-19 pandemic provides a unique opportunity to examine the country's clinical health research ecosystem. We sought to describe patterns of enrolment across Canadian Institutes of Health Research (CIHR)-funded studies on COVID-19.

METHODS

We identified COVID-19 studies funded by the CIHR and that enrolled participants from Canadian acute care hospitals between January 2020 and April 2023. We collected information on study-and site-level variables from study leads, site investigators, and public domain sources. We described and evaluated factors associated with cumulative enrolment.

RESULTS

We obtained information for 23 out of 26 (88%) eligible CIHR-funded studies (16 randomized controlled trials [RCTs] and 7 cohort studies). The 23 studies were managed by 12 Canadian and 3 international coordinating centres. Of 419 Canadian hospitals, 97 (23%) enrolled a total of 28 973 participants - 3876 in RCTs across 78 hospitals (median cumulative enrolment per hospital 30, interquartile range [IQR] 10-61), and 25 097 in cohort studies across 62 hospitals (median cumulative enrolment per hospital 158, IQR 6-348). Of 78 hospitals recruiting participants in RCTs, 13 (17%) enrolled 50% of all RCT participants, whereas 6 of 62 hospitals (9.7%) recruited 54% of participants in cohort studies.

INTERPRETATION

A minority of Canadian hospitals enrolled the majority of participants in CIHR-funded studies on COVID-19. This analysis sheds light on the Canadian health research ecosystem and provides information for multiple key partners to consider ways to realize the full research potential of Canada's health systems.

Anticoagulation in COVID-19 patients - An updated systematic review and meta-analysis

BACKGROUND

Thromboembolic events are common complications of COVID-19. Clinical study results on safety and efficacy of anticoagulation in COVID-19 are controversial.

MATERIAL AND METHODS

This report is the second update of our systematic review with meta-analysis on randomized controlled trials (RCTs) comparing standard thromboprophylaxis, intermediate or therapeutic dose anticoagulation or no anticoagulation in COVID-19 in- and outpatients. We searched eligible studies up to 5 October 2023. Certainty of evidence was assessed using GRADE.

RESULTS

For this update we included fourteen new RCTs and a total of 27 RCTs with 16,789 patients. Certainty of evidence ranged from very low to high depending on outcome and comparison. Standard thromboprophylaxis with low dose anticoagulation may have little or no effect for COVID-19 outpatients compared to no anticoagulation. In inpatients with moderate or severe COVID-19, intermediate dose anticoagulation may decrease any thrombotic events or death, but may increase major bleeding compared to standard thromboprophylaxis. Therapeutic dose anticoagulation decreases thrombotic events or deaths in inpatients with moderate COVID-19, but probably has little or no effect in patients with severe COVID-19 compared to standard thromboprophylaxis with low or intermediate dose anticoagulation. With therapeutic dose anticoagulation, the risk of major bleeding probably increases regardless of COVID-19 severity. We are uncertain on the effect of thromboprophylaxis with low dose anticoagulation compared to no anticoagulation in the post-discharge setting.

CONCLUSIONS

Hospitalized, moderately-ill COVID-19 patients may benefit from intermediate or therapeutic dose anticoagulation, while critically ill patients may not. Risk of major bleeding must be considered.

Four years into the pandemic, managing COVID-19 patients with acute coagulopathy: what have we learned?

Coagulopathy alongside micro- and macrovascular thrombotic events were frequent characteristics of patients presenting with acute COVID-19 during the initial stages of the pandemic. However, over the past 4 years, the incidence and manifestations of COVID-19-associated coagulopathy have changed due to immunity from natural infection and vaccination and the appearance of new SARS-CoV-2 variants. Diagnostic criteria and management strategies based on early experience and studies for COVID-19-associated coagulopathy thus require reevaluation. As many other infectious disease states are also associated with hemostatic dysfunction, the coagulopathy associated with COVID-19 may be compounded, especially throughout the winter months, in patients with diverse etiologies of COVID-19 and other infections. This commentary examines what we have learned about COVID-19-associated coagulopathy throughout the pandemic and how we might best prepare to mitigate the hemostatic consequences of emerging infection agents.

An Autopsy Case of Severe COVID-19 Pneumonia Complicated by Intrapulmonary Thrombosis in Myelodysplastic/Myeloproliferative Neoplasm With Ring Sideroblasts and Thrombocytosis

Patients with coronavirus disease 2019 (COVID-19) pneumonia are prone to intrapulmonary thrombosis owing to excessive inflammation and platelet activation. Myelodysplastic/myeloproliferative neoplasm (MDS/MPN) with ring sideroblasts and thrombocytosis (RS-T) is a rare disease in MDS/MPN overlap entities. Patients with MDS/MPN RS-T are known to be at a high risk of thrombosis, and platelet count control with drug therapy does not necessarily reduce this risk. Here, we report the autopsy case of an older male patient with MDS/MPN RS-T and severe COVID-19 pneumonia complicated by intrapulmonary thrombosis. His platelet count had been controlled in the normal range after treatment with hydroxyurea and 5-aza-2'-deoxycytidine. On admission day, he rapidly developed respiratory distress and tested positive on a polymerase chain reaction test for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). After admission, he received supplemental oxygen and was administered remdesivir and dexamethasone; however, his respiratory and circulatory status did not improve. The patient died on day 4 of illness. Autopsy findings revealed massive thrombi within blood vessels and diffuse alveolar damage in both lungs, which were determined to be the cause of death. In patients with MDS/MPN RS-T combined with COVID-19 pneumonia, clinicians may need to pay close attention to the risk of pulmonary thrombosis.

Appropriate thromboprophylaxis strategy for COVID-19 patients on dosage, antiplatelet therapy, outpatient, and postdischarge prophylaxis: a meta-analysis of randomized controlled trials

BACKGROUND

There was controversy surrounding the optimal thromboprophylaxis strategy for coronavirus disease 2019 (COVID-19) patients. This included debates on the dosage of anticoagulants for thromboembolism prophylaxis, the requirement for additional antiplatelet therapy, and the necessity of prophylaxis for outpatients and postdischarge. To explore this, the authors performed a meta-analysis of randomized controlled trials.

METHODS

PubMed, Cochrane Library, Embase, and Web of Science were last searched on 26 July 2023 for studies comparing the effect of different dose of anticoagulation, additional antiplatelet, and postdischarge prophylaxis for COVID-19 patients. The results of eligible studies were analyzed in terms of thromboembolism events, major bleeding and all-cause mortality during follow-up.

RESULTS

Our study included a total of 25 randomized controlled trials, involving 17 911 patients. Our results revealed that, compared to prophylactic dose, therapeutic dose showed lower thrombotic risk (RR, 0.66; 95% CI: 0.45-0.96) but had similar major bleeding risk for critically ill patients with COVID-19. On the other hand, intermediate dose and prophylactic dose demonstrated similar thromboembolism risk and major bleeding risk. For noncritically ill patients with COVID-19, therapeutic dose of anticoagulants was associated with lower thrombotic risk (RR, 0.50; 95% CI: 0.34-0.72) but, at the same time, increased the risk of major bleeding (RR, 2.01; 95% CI: 1.22-3.33). However, intermediate dose showed lower thromboembolism risk (RR, 0.38; 95% CI: 0.21-0.69) while maintaining a similar major bleeding risk. In critically ill patients, additional antiplatelet therapy showed similar thromboembolism, major bleeding risk, and mortality when compared to no treatment. For outpatients, additional prophylactic anticoagulation showed similar thromboembolism, major bleeding risk, and mortality when compared to no treatment. For postdischarge patients, postdischarge prophylaxis reduced thromboembolism risk (RR, 0.49; 95% CI: 0.31-0.76) but increased major bleeding risk (RR, 2.63; 95% CI: 1.13-6.14).

CONCLUSION

For noncritically ill patients, therapeutic dose prophylactic anticoagulation significantly reduced venous thromboembolism but increases major bleeding risk. Intermediate dose effectively lowered venous thromboembolism without raising major bleeding risk. The optimal dose and need for additional antiplatelet therapy in critically ill patients, as well as the necessity of prophylactic anticoagulation in outpatient and postdischarge patients, required further investigation and confirmation through rigorous evidence studies.

Promising Drug Fondaparinux for the Treatment of COVID-19: an In Silico Analysis of Low Molecular Weight Heparin, Direct Oral Anticoagulant, and Antiplatelet Drug Interactions with Host Protease Furin

PURPOSE

As of July 2022, the COVID-19 pandemic has affected over 555 million worldwide confirmed cases and caused more than 6.3 million deaths. The studies showed that the D-dimer levels were increased in non-survivors compared to survivors and heparin treatment has begun to be administered to the patients in severe clinics. As we knew that the entrance of SARS-CoV-2 to the host cell needs to be facilitated by host proteases; we published our hypothesis that heparin as a serine protease inhibitor may block the interaction between spike protein receptor-binding domain and host proteases. In our study, we aimed to investigate the interactions between not only heparins but also other antiplatelet and anticoagulant drugs including fondaparinux.

METHODS

In this study, docking studies were carried out to evaluate the interactions between low molecular weight heparins (LMWHs) (enoxaparin, dalteparin, tinzaparin), direct oral anticoagulant, and antiplatelet drugs with host proteases. Molecular docking studies were performed by using Schrödinger molecular modeling software. 3D structures of the ligands were obtained from the 2D structures by assigning the OPLS-2005 force field using the Maestro 12.7. The 3D crystal structure of the furin complexed with an inhibitor, 2,5-dideoksistreptamin derivative, was extracted from the Protein Data Bank (PDB ID: 5MIM). Docking studies were carried out using the Grid-based Ligand Docking with Energetics module of the Schrödinger Software.

RESULTS

The docking studies revealed that fondaparinux was the most relevant molecule to interact with furin with a docking score of - 12.74. It showed better interaction than the natural ligand of furin with an increased score compared to the docking score of - 8.155 of the natural ligand. AnaGA*IsA structure representing LMWH structure has shown a docking score of - 11.562 which was also better than the score of the natural ligand of furin.

CONCLUSION

Our findings have shown that LMWHs and fondaparinux can be used for their possible antiviral effects in COVID-19 patients. Our results have shown that in accordance with heparin and LMWH, fondaparinux can also be a candidate for "drug repurposing" in COVID-19 therapy, not only because of their anticoagulant but also possible antiviral effects.

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.

Venous thromboembolism in Black COVID-19 patients in a minority context compared to White, Asian and other racialized patients: A systematic review and meta-analysis

IMPORTANCE

COVID-19 has disproportionately affected racialized populations, with particular impact among individuals of Black individuals. However, it is unclear whether disparities in venous thromboembolic (VTE) complications exist between Black individuals and those belonging to other racial groups with confirmed SARS-CoV2 infections.

OBJECTIVE

To summarize the prevalence and moderators associated with VTE among Black COVID-19 patients in minoritized settings, and to compare this to White and Asian COVID-19 patients according to sex, age, and comorbid health conditions (heart failure, cancer, obesity, hypertension).

DESIGN SETTING, AND PARTICIPANTS

A systematic search of MEDLINE, Embase, CINAHL and CENTRAL for articles or reports published from inception to February 15, 2023.

STUDY SELECTION

Reports on VTE among Black individuals infected with SARS-CoV2, in countries where Black people are considered a minority population group.

DATA EXTRACTION AND SYNTHESIS

Study characteristics and results of eligible studies were independently extracted by 2 pairs of reviewers. VTE prevalence was extracted, and risk of bias was assessed. Prevalence estimates of VTE prevalence among Black individuals with COVID19 in each study were pooled. Where studies provided race-stratified VTE prevalence among COVID19 patients, odds ratios were generated using a random-effects model.

MAIN OUTCOMES AND MEASURES

Prevalence of VTE, comprising of deep vein thrombosis and pulmonary embolism.

RESULTS

Ten studies with 66,185 Black individuals reporting the prevalence of COVID-19 associated VTE were included. Weighted median age of included studies was 47.60. Pooled prevalence of COVID-19 associated VTE was 7.2 % (95 % CI, 3.8 % - 11.5 %) among Black individuals. Among individuals with SARS-CoV2 infections, Black population had higher risks of VTE compared to their White (OR = 1.79, [95 % CI 1.28-2.53], p < .001) or Asian (OR = 2.01, [95 % CI, 1.14-3.60], p = .017) counterparts, or patients with other racial identities (OR = 2.01, [95 % CI, 1.39, 2.92]; p < .001).

CONCLUSIONS AND RELEVANCE

Black individuals with COVID-19 had substantially higher risk of VTE compared to White or Asian individuals. Given racial disparities in thrombotic disease burden related to COVID-19, medical education, research, and health policy interventions are direly needed to ensure adequate disease awareness among Black individuals, to facilitate appropriate diagnosis and treatment among Black patients with suspected and confirmed VTE, and to advocate for culturally safe VTE prevention strategies, including pre-existing inequalities to the COVID-19 pandemic that persist after the crisis.

Automatic Population of the Case Report Forms for an International Multifactorial Adaptive Platform Trial Amid the COVID-19 Pandemic

OBJECTIVES

To automatically populate the case report forms (CRFs) for an international, pragmatic, multifactorial, response-adaptive, Bayesian COVID-19 platform trial.

METHODS

The locations of focus included 27 hospitals and 2 large electronic health record (EHR) instances (1 Cerner Millennium and 1 Epic) that are part of the same health system in the United States. This paper describes our efforts to use EHR data to automatically populate four of the trial's forms: baseline, daily, discharge, and response-adaptive randomization.

RESULTS

Between April 2020 and May 2022, 417 patients from the UPMC health system were enrolled in the trial. A MySQL-based extract, transform, and load pipeline automatically populated 499 of 526 CRF variables. The populated forms were statistically and manually reviewed and then reported to the trial's international data coordinating center.

CONCLUSIONS

We accomplished automatic population of CRFs in a large platform trial and made recommendations for improving this process for future trials.

A systematic review of thromboembolic complications and outcomes in hospitalised COVID-19 patients

Thromboembolic (TE) complications [myocardial infarction (MI), stroke, deep vein thrombosis (DVT), and pulmonary embolism (PE)] are common causes of mortality in hospitalised COVID-19 patients. Therefore, this review was undertaken to explore the incidence of TE complications and mortality associated with TE complications in hospitalised COVID-19 patients from different studies. A literature search was performed using ScienceDirect and PubMed databases using the MeSH term search strategy of "COVID-19", "thromboembolic complication", "venous thromboembolism", "arterial thromboembolism", "deep vein thrombosis", "pulmonary embolism", "myocardial infarction", "stroke", and "mortality". There were 33 studies included in this review. Studies have revealed that COVID-19 patients tend to develop venous thromboembolism (PE:1.0-40.0% and DVT:0.4-84%) compared to arterial thromboembolism (stroke:0.5-15.2% and MI:0.8-8.7%). Lastly, the all-cause mortality of COVID-19 patients ranged from 4.8 to 63%, whereas the incidence of mortality associated with TE complications was between 5% and 48%. A wide range of incidences of TE complications and mortality associated with TE complications can be seen among hospitalized COVID-19 patients. Therefore, every patient should be assessed for the risk of thromboembolic complications and provided with an appropriate thromboprophylaxis management plan tailored to their individual needs.

Protocol implementation during the COVID-19 pandemic: experiences from a randomized trial of stress ulcer prophylaxis

BACKGROUND

During the COVID-19 pandemic, many intensive care units (ICUs) halted research to focus on COVID-19-specific studies.

OBJECTIVE

To describe the conduct of an international randomized trial of stress ulcer prophylaxis (Re-Evaluating the Inhibition of Stress Erosions in the ICU [REVISE]) during the pandemic, addressing enrolment patterns, center engagement, informed consent processes, data collection, a COVID-specific substudy, patient transfers, and data monitoring.

METHODS

REVISE is a randomized trial among mechanically ventilated patients, comparing pantoprazole 40 mg IV to placebo on the primary efficacy outcome of clinically important upper gastrointestinal bleeding and the primary safety outcome of 90-day mortality. We documented protocol implementation status from March 11th 2020-August 30th 2022.

RESULTS

The Steering Committee did not change the scientific protocol. From the first enrolment on July 9th 2019 to March 10th 2020 (8 months preceding the pandemic), 267 patients were enrolled in 18 centers. From March 11th 2020-August 30th 2022 (30 months thereafter), 41 new centers joined; 59 were participating by August 30th 2022 which enrolled 2961 patients. During a total of 1235 enrolment-months in the pandemic phase, enrolment paused for 106 (8.6%) months in aggregate (median 3 months, interquartile range 2;6). Protocol implementation involved a shift from the a priori consent model pre-pandemic (188, 58.8%) to the consent to continue model (1615, 54.1%, p < 0.01). In one new center, an opt-out model was approved. The informed consent rate increased slightly (80.7% to 85.0%, p = 0.05). Telephone consent encounters increased (16.6% to 68.2%, p < 0.001). Surge capacity necessitated intra-institutional transfers; receiving centers continued protocol implementation whenever possible. We developed a nested COVID-19 substudy. The Methods Centers continued central statistical monitoring of trial metrics. Site monitoring was initially remote, then in-person when restrictions lifted.

CONCLUSION

Protocol implementation adaptations during the pandemic included a shift in the consent model, a sustained high consent rate, and launch of a COVID-19 substudy. Recruitment increased as new centers joined, patient transfers were optimized, and monitoring methods were adapted.

The effect of COVID-19 on the thromboembolic outcomes in atrial fibrillation patients in the long run

BACKGROUND

While there has been a wealth of reports concerning the acute effects of the coronavirus disease 2019 (COVID-19), further information is needed to see how things unfold in the long run. This research aimed to ascertain whether the COVID-19 pandemic has increased the probability of thromboembolic events in atrial fibrillation (AF) patients.

METHODS

In this retrospective study, we scanned 952 AF patients and classified 643 eligible ones per their history of catching COVID-19. Two hundred thirty-nine of 643 patients had a history of COVID-19 (Group 1), and 404 did not (Group 2). We then compared two years of thromboembolic events between the groups.

RESULTS

Composite thromboembolic outcomes were seen in 76 (11.8%) patients. Of those, 32 (13.4%) were in Group 1, and 44 (10.8%) were in Group 2 (p = .03). 10 of 32 patients (31%) in Group 1 and 11 of 44 (25%) in Group 2 died because of thromboembolic events (p = .02). Histories of diabetes mellitus, chronic obstructive pulmonary disease, and COVID-19 independently predicted thromboembolic events in AF patients.

CONCLUSIONS

Having caught COVID-19 is likely to be associated with increased long-term thromboembolic outcomes in AF patients. Albeit the study design does not permit us to infer causality, our results question the necessity of more intensive anticoagulant therapy and closer follow-up in AF patients with past COVID-19.

The effect of current antithrombotic therapy on mortality in nursing home residents with COVID-19: a multicentre retrospective cohort study

BACKGROUND

The first wave of COVID led to an alarmingly high mortality rate among nursing home residents (NHRs). In hospitalised patients, the use of anticoagulants may be associated with a favourable prognosis. However, it is unknown whether the use of antithrombotic medication also protected NHRs from COVID-19-related mortality.

OBJECTIVES

To investigate the effect of current antithrombotic therapy in NHRs with COVID-19 on 30-day all-cause mortality during the first COVID-19 wave.

METHODS

We performed a retrospective cohort study linking electronic health records and pharmacy data in NHRs with COVID-19. A propensity score was used to match NHRs with current use of therapeutic dose anticoagulants to NHRs not using anticoagulant medication. The primary outcome was 30-day all-cause mortality, which was evaluated using a logistic regression model. In a secondary analysis, multivariable logistic regression was performed in the complete study group to compare NHRs with current use of therapeutic dose anticoagulants and those with current use of antiplatelet therapy to those without such medication.

RESULTS

We included 3521 NHRs with COVID-19 based on a positive RT-PCR for SARS-CoV-2 or with a well-defined clinical suspicion of COVID-19. In the matched propensity score analysis, NHRs with current use of therapeutic dose anticoagulants had a significantly lower all-cause mortality (OR = 0.73; 95% CI: 0.58-0.92) compared to NHRs who did not use therapeutic anticoagulants. In the secondary analysis, current use of therapeutic dose anticoagulants (OR: 0.62; 95% CI: 0.48-0.82) and current use of antiplatelet therapy (OR 0.80; 95% CI: 0.64-0.99) were both associated with decreased mortality.

CONCLUSIONS

During the first COVID-19 wave, therapeutic anticoagulation and antiplatelet use were associated with a reduced risk of all-cause mortality in NHRs. Whether these potentially protective effects are maintained in vaccinated patients or patients with other COVID-19 variants, remains unknown.

Advances and current research in primary thromboprophylaxis to prevent hospital-associated venous thromboembolism

Hospital-associated venous thromboembolism (VTE) is defined as any case of VTE occurring during hospital admission and for up to 90 days post discharge. It accounts for over 50% of all cases of VTE internationally; indeed, there are an estimated 10 million cases of hospital-associated VTE annually. Over the last decade, there has been increasing interest in improving VTE risk assessment and thromboprophylaxis. This review summarises all the recent and ongoing major research studies and future challenges in the different areas, including medical, surgical and obstetric patients, as well as special areas such as lower limb immobilisation. We include sections on both pharmacological and mechanical thromboprophylaxis.

Thrombotic Markers in Pregnant Patients with and without SARS-CoV-2 Infection

BACKGROUND

Coronavirus disease 2019 (COVID-19) is associated with coagulation abnormalities and increased risk for venous and arterial thrombi. This study aimed to evaluate D-dimer levels and lupus anticoagulant (LAC) positivity in pregnant individuals with and without Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

STUDY DESIGN

This was a prospective cohort study of pregnant individuals delivering at a single academic institution from April 2020 to March 2022. Individuals with a positive SARS-CoV-2 result during pregnancy were compared with a convenience sample of those without a positive SARS-CoV-2 result. For individuals with SARS-CoV-2 infection, severity was assessed based on the National Institutes of Health classification system. The primary outcome was D-dimer level measured during delivery admission. The secondary outcomes were LAC positivity and thromboembolic events. Outcomes were compared between individuals with and without a positive SARS-CoV-2 result, and further by disease severity.

RESULTS

Of 98 participants, 77 (78.6%) were SARS-CoV-2 positive during pregnancy. Among individuals with SARS-CoV-2 infection, severity was asymptomatic in 20 (26.0%), mild in 13 (16.9%), moderate in 4 (5.2%), severe in 38 (49.4%), and critical in 2 (2.6%). The D-dimer concentration at delivery did not significantly differ between those with a SARS-CoV-2 positive result compared with those without (mean 2.03 µg/mL [95% confidence interval {CI} 1.72-2.40] vs. 2.37 µg/mL [95% CI 1.65-3.40]; p = 0.43). Three individuals (4%) with SARS-CoV-2 infection and none (0%) without infection were LAC positive (p = 0.59). There were no clinically apparent thromboses in either group. D-dimer concentrations and LAC positive results did not differ by COVID-19 severity.

CONCLUSION

Thrombotic markers did not differ in pregnant individuals by SARS-CoV-2 infection; however, high rates of LAC positivity were detected.

KEY POINTS

· Thrombotic markers did not differ in pregnant individuals by SARS-CoV-2 infection.. · Higher than expected rates of LAC positivity were detected.. · There were no clinically apparent thromboses..

Monocyte-Mediated Thrombosis Linked to Circulating Tissue Factor and Immune Paralysis in COVID-19

BACKGROUND

SARS-CoV-2 infections cause COVID-19 and are associated with inflammation, coagulopathy, and high incidence of thrombosis. Myeloid cells help coordinate the initial immune response in COVID-19. Although we appreciate that myeloid cells lie at the nexus of inflammation and thrombosis, the mechanisms that unite the two in COVID-19 remain largely unknown.

METHODS

In this study, we used systems biology approaches including proteomics, transcriptomics, and mass cytometry to define the circulating proteome and circulating immune cell phenotypes in subjects with COVID-19.

RESULTS

In a cohort of subjects with COVID-19 (n=35), circulating markers of inflammation (CCL23 [C-C motif chemokine ligand 23] and IL [interleukin]-6) and vascular dysfunction (ACE2 [angiotensin-converting enzyme 2] and TF [tissue factor]) were elevated in subjects with severe compared with mild COVID-19. Additionally, although the total white blood cell counts were similar between COVID-19 groups, CD14+ (cluster of differentiation) monocytes from subjects with severe COVID-19 expressed more TF. At baseline, transcriptomics demonstrated increased IL-6, CCL3, ACOD1 (aconitate decarboxylase 1), C5AR1 (complement component 5a receptor), C5AR2, and TF in subjects with severe COVID-19 compared with controls. Using stress transcriptomics, we found that circulating immune cells from subjects with severe COVID-19 had evidence of profound immune paralysis with greatly reduced transcriptional activation and release of inflammatory markers in response to TLR (Toll-like receptor) activation. Finally, sera from subjects with severe (but not mild) COVID-19 activated human monocytes and induced TF expression.

CONCLUSIONS

Taken together, these observations further elucidate the pathological mechanisms that underlie immune dysfunction and coagulation abnormalities in COVID-19, contributing to our growing understanding of SARS-CoV-2 infections that could also be leveraged to develop novel diagnostic and therapeutic strategies.

Mechanisms of Pulmonary Vasculopathy in Acute and Long-Term COVID-19: A Review

Despite the end of the pandemic, coronavirus disease 2019 (COVID-19) remains a major public health concern. The first waves of the virus led to a better understanding of its pathogenesis, highlighting the fact that there is a specific pulmonary vascular disorder. Indeed, COVID-19 may predispose patients to thrombotic disease in both venous and arterial circulation, and many cases of severe acute pulmonary embolism have been reported. The demonstrated presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within the endothelial cells suggests that direct viral effects, in addition to indirect effects of perivascular inflammation and coagulopathy, may contribute to pulmonary vasculopathy in COVID-19. In this review, we discuss the pathological mechanisms leading to pulmonary vascular damage during acute infection, which appear to be mainly related to thromboembolic events, an impaired coagulation cascade, micro- and macrovascular thrombosis, endotheliitis and hypoxic pulmonary vasoconstriction. As many patients develop post-COVID symptoms, including dyspnea, we also discuss the hypothesis of pulmonary vascular damage and pulmonary hypertension as a sequela of the infection, which may be involved in the pathophysiology of long COVID.