Efficacy and Safety of Therapeutic-Dose Heparin vs Standard Prophylactic or Intermediate-Dose Heparins for Thromboprophylaxis in High-risk Hospitalized Patients With COVID-19: The HEP-COVID Randomized Clinical Trial

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.

Pulmonary thrombosis associated with COVID-19 pneumonia: Beyond classical pulmonary thromboembolism

BACKGROUND

Classical pulmonary thromboembolism (TE) and local pulmonary thrombosis (PT) have been suggested as mechanisms of thrombosis in COVID-19. However, robust evidence is still lacking because this was mainly based on retrospective studies, in which patients were included when TE was suspected.

METHODS

All patients with COVID-19 pneumonia underwent computed tomography and pulmonary angiography in a prospective study. The main objective was to determine the number and percentage of thrombi surrounded by lung opacification (TSO) in each patient, as well as their relationship with percentage of lung involvement (TLI), to distinguish classical TE (with a random location of thrombi that should correspond to a percentage of TSO equivalent to the TLI) from PT. We determined TLI by artificial intelligence. Analyses at patient level (TLI and percentage of TSO) and at thrombi level (TLI and TSO) were performed.

RESULTS

We diagnosed TE in 70 out of 184 patients. Three (2-8) thrombi/patient were detected. The percentage of TSO was 100% (75-100) per patient, and TLI was 19.9% (4.6-35.2). Sixty-five patients (92.9%) were above the random scenario with higher percentage of TSO than TLI. Most thrombi were TSO (n = 299, 75.1%). When evaluating by TLI (<10%, 10%-20%, 20%-30% and >30%), percentage of TSO was higher in most groups. Thrombi were mainly in subsegmental/segmental arteries, and percentage of TSO was higher in all locations.

CONCLUSIONS

Thrombi in COVID-19 were found within lung opacities in a higher percentage than lung involvement, regardless of TLI and clot location, supporting the hypothesis of local PT rather than "classic TE".

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.

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.

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.

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.

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.

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.

[COVID-19 in the intensive care unit]

The acute respiratory failure as well as ARDS (acute respiratory distress syndrome) have challenged clinicians since the initial description over 50 years ago. Various causes can lead to ARDS and therapeutic approaches for ARDS/ARF are limited to the support or replacement of organ functions and the prevention of therapy-induced consequences. In recent years, triggered by the SARS-CoV-2 pathogen, numerous cases of acute lung failure (C-ARDS) have emerged. The pathophysiological processes of classical ARDS and C-ARDS are essentially similar. In their final stages of inflammation, both lead to a disruption of the blood-air barrier. Treatment strategies for C-ARDS, like classical ARDS, focus on supporting or replacing organ functions and preventing consequential damage. This article summarizes the treatment strategies in the intensive care unit.

Chronic Anticoagulation in Patients with Atrial Fibrillation and COVID-19: A Systematic Review and Meta-Analysis

BACKGROUND

Coronavirus disease 2019 (COVID-19) is associated with hypercoagulability. It remains uncertain whether ongoing anticoagulation for atrial fibrillation (AF) in patients who later contract COVID-19 improves clinical outcomes.

OBJECTIVES

To compare chronic oral anticoagulation with no previous anticoagulation in patients with AF who contracted a COVID-19 infection concerning the outcomes of all-cause mortality, COVID-19 mortality, intensive care unit (ICU) admission, and hospitalization.

METHODS

We systematically searched PubMed, Embase, and Cochrane Library for eligible studies from inception to December 2022. We included studies comparing COVID-19 outcomes in patients with versus without prior chronic anticoagulation for AF. Risk ratios (RR) with 95% confidence intervals (CI) were pooled with a random-effects model. The level of significance was set at p < 0.05. Quality assessment and risk of bias were performed according to Cochrane recommendations.

RESULTS

Ten studies comprising 1,177,858 patients with COVID-19 and AF were identified, of whom 893,772 (75.9%) were on prior chronic anticoagulation for AF. In patients with COVID-19, being on chronic anticoagulation for AF significantly reduced all-cause mortality (RR 0.75; 95% CI 0.57 to 0.99; p = 0.048; I2 = 89%) and COVID-19-related mortality (RR 0.76; 95% CI 0.72 to 0.79; p < 0.001; I2 = 0%) when compared with no prior anticoagulation. In contrast, there was no difference between groups regarding hospitalization (RR 1.08; 95% CI 0.82 to 1.41; p = 0.587; I2 = 95%) or ICU admission (RR 0.86; 95% CI 0.68 to 1.09; p = 0.216; I2 = 69%).

CONCLUSIONS

In this meta-analysis, chronic anticoagulation for patients with AF who contracted COVID-19 was associated with significantly lower rates of all-cause mortality and COVID-19-related mortality as compared with no previous anticoagulation.

Lessons we learned during the past four challenging years in the COVID-19 era: pharmacotherapy, long COVID complications, and vaccine development

About four years have passed since the detection of the first cases of COVID-19 in China. During this lethal pandemic, millions of people have lost their lives around the world. Since the first waves of COVID-19 infection, various pharmacotherapeutic agents have been examined in the management of COVID-19. Despite all these efforts in pharmacotherapy, drug repurposing, and design and development of new drugs, multiple organ involvement and various complications occurred during COVID-19. Some of these complications became chronic and long-lasting which led to the "long COVID" syndrome appearance. Therefore, the best way to eradicate this pandemic is prophylaxis through mass vaccination. In this regard, various vaccine platforms including inactivated vaccines, nucleic acid-based vaccines (mRNA and DNA vaccines), adenovirus-vectored vaccines, and protein-based subunit vaccines have been designed and developed to prevent or reduce COVID-19 infection, hospitalization, and mortality rates. In this focused review, at first, the most commonly reported clinical presentations of COVID-19 during these four years have been summarized. In addition, different therapeutic regimens and their latest status in COVID-19 management have been listed. Furthermore, the "long COVID" and related signs, symptoms, and complications have been mentioned. At the end, the effectiveness of available COVID-19 vaccines with different platforms against early SARS-CoV-2 variants and currently circulating variants of interest (VOI) and the necessity of booster vaccine shots have been summarized and discussed in more detail.

Overall haemostatic potential assay for prediction of outcomes in venous and arterial thrombosis and thrombo-inflammatory diseases

Thromboembolic diseases including arterial and venous thrombosis are common causes of morbidity and mortality globally. Thrombosis frequently recurs and can also complicate many inflammatory conditions through the process of 'thrombo-inflammation,' as evidenced during the COVID-19 pandemic. Current candidate biomarkers for thrombosis prediction, such as D-dimer, have poor predictive efficacy. This limits our capacity to tailor anticoagulation duration individually and may expose lower risk individuals to undue bleeding risk. Global coagulation assays, such as the Overall Haemostatic Potential (OHP) assay, that investigate fibrin generation and fibrinolysis, may provide a more accurate and functional assessment of hypercoagulability. We present a review of fibrin's critical role as a central modulator of thrombotic risk. The results of our studies demonstrating the OHP assay as a predictive biomarker in venous thromboembolism, chronic renal disease, diabetes mellitus, post-thrombotic syndrome, and COVID-19 are discussed. As a comprehensive and global measurement of fibrin generation and fibrinolytic capacity, the OHP assay may be a valuable addition to future multi-modal predictive tools in thrombosis.

Characterization of the Benefits and Risks of Therapeutic Anticoagulation in Patients Admitted with Severe COVID-19 (CRITAC)

Background

Severe COVID-19 is associated with increased rates of thrombotic complications. Recent provincial recommendations in British Columbia have suggested providing thromboprophylaxis with therapeutic anticoagulation for hospital inpatients with severe COVID-19 who do not have a high risk of bleeding.

Objectives

To characterize the rates of major bleeding, thrombotic events, complications from COVID-19, and adverse effects among patients with severe COVID-19 treated with therapeutic anticoagulation.

Methods

This retrospective chart review involved patients with laboratory-confirmed COVID-19 who were admitted to 3 sites within a local health authority between April 1 and December 31, 2021, and received therapeutic anticoagulation for thromboprophylaxis.

Results

After screening of 1036 patients, 72 patients were included in the study. The mean age of participants was 54 years, 63% (n = 45) were male, and 92% (n = 66) were receiving supplemental oxygen by nasal prongs on admission. The primary outcome, major bleeding, was experienced by 1 patient (1%). Increasing oxygen requirements resulting in progression to high-flow nasal cannula occurred in 11 patients (15%), and 5 patients (7%) required admission to the intensive care unit. One patient (1%) experienced a thrombotic event, and 1 patient (1%) had a minor bleed. The mean duration of hospitalization was 10 (standard deviation 10.8) days. One death occurred during the study period, and no cases of heparin-induced thrombocytopenia were observed.

Conclusions

In this study of hospital inpatients with severe COVID-19 who were deemed to be at low risk of bleeding and who received therapeutic anticoagulation, there were low rates of both major bleeding and thrombotic events.

Effect of anticoagulation on the incidence of venous thromboembolism, major bleeding, and mortality among hospitalized COVID-19 patients: an updated meta-analysis

Objective

Anticoagulation is crucial for patients hospitalized with coronavirus disease 2019 (COVID-19) due to the high risk of venous thromboembolism (VTE). However, the optimal anticoagulation regimen needs further exploration. Therefore, we evaluated the efficacy and safety of diverse anticoagulation dosage dosages for COVID-19.

Methods

An updated meta-analysis was performed to assess the effect of thromboprophylaxis (standard, intermediate, and therapeutic dose) on the incidence of VTE, mortality and major bleeding among COVID-19 patients. Literature was searched via PubMed, EMBASE, Web of Science, and China National Knowledge Infrastructure (CNKI) database. The odds ratio (OR) and 95% confidence interval (CI) were calculated for effect estimates.

Results

Nineteen studies involving 25,289 participants without VTE history were included. The mean age of patients was 59.3 years old. About 50.96% were admitted to the intensive care unit. In the pooled analysis, both therapeutic-dose and intermediate-dose anticoagulation did not have a significant advantage in reducing VTE risk over standard dosage (OR = 1.09, 95% CI: 0.58-2.02, and OR = 0.89, 95% CI: 0.70-1.12, respectively). Similarly, all-cause mortality was not further decreased in either therapeutic-dose group (OR = 1.12, 95% CI: 0.75-1.67) or intermediate-dose group (OR = 1.34, 95% CI: 0.83-2.17). While the major bleeding risk was significantly elevated in the therapeutic-dose group (OR = 2.59, 95%CI: 1.87-3.57) as compared with the standard-dose regimen. Compared with intermediate dosage, therapeutic anticoagulation did not reduce consequent VTE risk (OR = 0.85, 95% CI: 0.52-1.38) and all-cause mortality (OR = 0.84, 95% CI: 0.60-1.17), but significantly increased major bleeding rate (OR = 2.42, 95% CI: 1.58-3.70). In subgroup analysis of patients older than 65 years, therapeutic anticoagulation significantly lowered the incidence of VTE in comparation comparison with standard thromboprophylaxis, however, at the cost of elevated risk of major bleeding.

Conclusion

Our results indicated that for most hospitalized patients with COVID-19, standard-dose prophylactic anticoagulation might be the optimal choice. For elderly patients at low risk of bleeding, therapeutic-dose anticoagulation could further reduce VTE risk and should be considered especially when there were other strong risk factors of VTE during hospital stay.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO, identifier, CRD42023388429.

Impact of the pandemic and concomitant COVID-19 on the management and outcomes of middle cerebral artery strokes: a nationwide registry-based study

OBJECTIVES

To investigate the impact of the COVID-19 pandemic as well as concomitant COVID-19 itself on stroke care, focusing on middle cerebral artery (MCA) territory infarctions.

DESIGN

Registry-based study.

SETTING

We used the National Inpatient Sample (NIS) database, which covers a wide range of hospitals within the USA.

PARTICIPANTS

The NIS was queried for patients with MCA strokes between 2016 and 2020. In total, 35 231 patients were included.

OUTCOME MEASURES

Outcome measures were postprocedural complications, length of stays (LOSs), in-hospital mortality and non-routine discharge. Propensity score matching using all available baseline variables was performed to reduce confounders when comparing patients with and without concomitant COVID-19.

RESULTS

Mechanical thrombectomy (MT) was performed in 48.4%, intravenous thrombolysis (IVT) in 38.2%, and both MT and IVT (MT+IVT) in 13.4% of patients. A gradual increase in the use of MT and an opposite decrease in the use of IVT (p<0.001) was detected during the study period. Overall, 25.0% of all patients were admitted for MCA strokes during the pandemic period (2020), of these 209 (2.4%) were concomitantly diagnosed with COVID-19. Patients with MCA strokes and concomitant COVID-19 were significantly younger (64.9 vs 70.0; p<0.001), had significantly worse NIH Stroke Severity scores, and worse outcomes in terms of LOS (12.3 vs 8.2; p<0.001), in-hospital mortality (26.3% vs 9.8%; p<0.001) and non-routine discharge (84.2% vs 76.9%; p=0.013), as compared with those without COVID-19. After matching, only in-hospital mortality rates remained significantly higher in patients with COVID-19 (26.7% vs 8.5%; p<0.001). Additionally, patients with COVID-19 had higher rates of thromboembolic (12.3% vs 7.6%; p=0.035) and respiratory (11.3% vs 6.6%; p=0.029) complications.

CONCLUSIONS

Among patients with MCA stroke, those with concomitant COVID-19 were significantly younger and had higher stroke severity scores. They were more likely to experience thromboembolic and respiratory complications and in-hospital mortality compared with matched controls.

COVID-19 and the brain: understanding the pathogenesis and consequences of neurological damage

SARS-CoV-2 has been known remarkably since December 2019 as a strain of pathogenic coronavirus. Starting from the earlier stages of the COVID-19 pandemic until now, we have witnessed many cases of neurological damage caused by SARS-CoV-2. There are many studies and research conducted on COVID-19-positive-patients that have found brain-related abnormalities with clear neurological symptoms, ranging from simple headaches to life-threatening strokes. For treating neurological damage, knowing the actual pathway or mechanism of causing brain damage via SARS-CoV-2 is very important. For this reason, we have tried to explain the possible pathways of brain damage due to SARS-CoV-2 with mechanisms and illustrations. The SARS-CoV-2 virus enters the human body by binding to specific ACE2 receptors in the targeted cells, which are present in the glial cells and CNS neurons of the human brain. It is found that direct and indirect infections with SARS-CoV-2 in the brain result in endothelial cell death, which alters the BBB tight junctions. These probable alterations can be the reason for the excessive transmission and pathogenicity of SARS-CoV-2 in the human brain. In this precise review, we have tried to demonstrate the neurological symptoms in the case of COVID-19-positive-patients and the possible mechanisms of neurological damage, along with the treatment options for brain-related abnormalities. Knowing the transmission mechanism of SARS-CoV-2 in the human brain can assist us in generating novel treatments associated with neuroinflammation in other brain diseases.

Comparison of Standard Versus Intermediate Prophylaxis Dose for Venous Thromboembolism Prophylaxis in Patients Hospitalized With COVID-19 Infection

Background: COVID-19 infection is associated with a high risk of venous thromboembolism (VTE) events. VTE prophylaxis reduces the risk of these events. The optimal dose of VTE prophylaxis however remains uncertain. Objectives: To compare the incidence of VTE in patients treated with either standard dose VTE versus intermediate dose VTE prophylaxis. Methods: In this retrospective cohort study, we analyzed data from 1786 adult patients admitted into the hospital with polymerase chain reaction confirmed COVID-19 infection between April 2020 to September 2021. For analysis, patients were divided into 2 cohorts: either standard dose prophylaxis treatment group (patients who received either unfractionated heparin 5000units 3 times a day or enoxaparin 30-40 mg daily subcutaneously) or intermediate dose VTE prophylaxis group (patients received either unfractionated heparin 7500 units 3 times daily or enoxaparin 30-40 mg twice a day subcutaneously). The primary outcome was incidence of VTE events described as either deep vein thrombosis (DVT) or pulmonary embolism (PE). Secondary outcome was bleeding events. Results: During the study period, 398 (22%) patients were primarily treated with standard dose VTE prophylaxis, whereas 1388 (78%) patients were treated with intermediate dose VTE prophylaxis. There was a significantly higher incidence of venous thromboembolism events noted in the standard dose prophylaxis treatment group when compared with the intermediate dose prophylaxis group (25/398 (6.3%) vs 35/1388 (2.5%) P < .001, [Odds Ratio 2.6197, 95% confidence interval = 1.5482-4.4327]). Multivariable-adjusted logistic regression, adjusting for age, obesity, and smoking, with the intermediate dose prophylaxis treatment group as the referent category revealed higher odds for incident venous thromboembolism events in the standard dose prophylaxis group. There was no statistically significant difference in bleeding events between the 2 treatment groups (9 (2.3%) for standard dose prophylaxis group vs 46 (3.3%) for intermediate dose prophylaxis group P = .26). Conclusions: Among patients hospitalized with COVID-19 infection, patients receiving intermediate dose VTE prophylaxis experienced lower incident rates of venous thromboembolism events compared to those receiving standard dose VTE prophylaxis without a statistically significant increase in the risk of bleeding events.

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.

Presence of procoagulant peripheral blood mononuclear cells in severe COVID-19 patients relate to ventilation perfusion mismatch and precede pulmonary embolism

PURPOSE

Pulmonary emboli (PE) contribute substantially to coronavirus disease 2019 (COVID-19) related mortality and morbidity. Immune cell-mediated hyperinflammation drives the procoagulant state in COVID-19 patients, resulting in immunothrombosis. To study the role of peripheral blood mononuclear cells (PBMC) in the procoagulant state of COVID-19 patients, we performed a functional bioassay and related outcomes to the occurrence of PE. Secondary aims were to relate this functional assay to plasma D-dimer levels, ventilation perfusion mismatch and TF expression on monocyte subsets.

METHODS

PBMC from an ICU biobank were obtained from 20 patients with a computed tomography angiograph (CTA) proven PE and compared to 15 COVID-19 controls without a proven PE. Functional procoagulant properties of PBMC were measured using a modified fibrin generation time (MC-FGT) assay. Tissue factor (TF) expression on monocyte subsets were measured by flow cytometry. Additional clinical data were obtained from patient records including end-tidal to arterial carbon dioxide gradient.

RESULTS

MC-FGT levels were highest in the samples taken closest to the PE detection, similar to the end-tidal to arterial carbon dioxide gradient (ETCO2 - PaCO2), a measurement to quantify ventilation-perfusion mismatch. In patients without proven PE, peak MC-FGT relates to an increase in end-tidal to arterial carbon dioxide gradient. We identified non-classical, CD16 positive monocytes as the subset with increased TF expression.

CONCLUSION

We show that the procoagulant state of PBMC could aid in early detection of PE in COVID-19 ICU patients. Combined with end-tidal to ETCO2 - PaCO2 gradient, these tests could improve early detection of PE on the ICU.

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.

COVID-19 and cardiovascular disease in patients with chronic kidney disease

Millions of people worldwide have chronic kidney disease (CKD). Affected patients are at high risk for cardiovascular (CV) disease for several reasons. Among various comorbidities, CKD is associated with the more severe forms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This is particularly true for patients receiving dialysis or for kidney recipients. From the start of the SARS-CoV-2 pandemic, several CV complications have been observed in affected subjects, spanning acute inflammatory manifestations, CV events, thrombotic episodes and arrythmias. Several pathogenetic mechanisms have been hypothesized, including direct cytopathic viral effects on the myocardium, endothelial damage and hypercoagulability. This spectrum of disease can occur during the acute phase of the infection, but also months after recovery. This review is focussed on the CV complications of coronavirus disease 2019 (COVID-19) with particular interest in their implications for the CKD population.

Multisite spontaneous hematomas and bleeding in critically ill Chinese patients with COVID-19: two case reports and a literature review

BACKGROUND

Anticoagulation is recommended as a standardized therapy for COVID-19 patients according to the WHO guidelines. However, bleeding events have also been reported. Hemorrhage or hematoma was observed in sites including the retroperitoneum, brain, alimentary tract, muscles, and soft tissues. Reduction or suspension of anticoagulants is a common intervention. Transfusion, endoscopic hemostasis, and vascular interventional therapy have been used to improve the condition.

CASE PRESENTATION

In this article, we present two cases of concurrent multisite hematomas and bleeding at other sites in patients with SARS-CoV-2 infection. Both patients were treated with heparins and experienced bleeding after the anticoagulation therapy. Both patients were older with more than two comorbidities, and critical COVID-19. Laboratory tests revealed a considerable decrease in hemoglobin levels and alterations in the coagulation system. In the first patient, the main intervention was embolization using angiography. However, we only adjusted the anticoagulation strategy in the second case. The first patient recovered and was discharged; however, the second died of other causes. This study provides a retrospective review of typical hemorrhagic cases during anticoagulation in COVID-19 patients over the course of four years. A relatively comprehensive search was performed in Pubmed by constructing MeSH subject terms on limiting the search period and specific contents. It summarizes and synthesizes the research related to heparins and other novel anticoagulants in the context of COVID-19 from the onset of the pandemic to the present disseminated phase. This study aimed to offer valuable insights and reference points for developing anticoagulation treatment strategies for patients with COVID-19.

CONCLUSIONS

Anticoagulation is a crucial treatment option for patients with COVID-19. The difference in anticoagulant effects is related to the severity of COVID-19. Nafamostat can reduce thrombosis in the extracorporeal circuits in critically ill patients with COVID-19. The efficacy and safety of novel anticoagulants require further clinical data. Routine bedside assessments and real-time laboratory monitoring are essential for early identification of bleeding events during anticoagulant therapy and administering intervention.

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.

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.

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.

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..

Longitudinal analysis of chest Q-SPECT/CT in patients with severe COVID-19

INTRODUCTION

Patients with COVID-19 have an increased risk for microvascular lung thrombosis. In order to evaluate the type and prevalence of perfusion defects, we performed a longitudinal analysis of combined perfusion single-photon emission and low-dose computed tomography (Q-SPECT/CT scan) in patients with COVID-19 pneumonia.

METHODS

Consecutive patients with severe COVID-19 (B.1.1.7 variant SARS-CoV-2) and respiratory insufficiency underwent chest Q-SPECT/CT during hospitalization, and 3 months after discharge. At follow-up (FU), Q-SPECT/CT were analyzed and compared with pulmonary function tests (PFT), blood analysis (CRP, D-dimers, ferritin), modified Medical Research Council (mMRC) dyspnea scale, and high-resolution CT scans (HRCT). Patients with one or more segmental perfusion defects outside the area of inflammation (PDOI) were treated with anticoagulation until FU.

RESULTS

At baseline, PDOI were found in 50 of 105 patients (47.6 %). At FU, Q-SPECT/CT scans had improved significantly (p < 0.001) and PDOI were recorded in 14 of 77 (18.2 %) patients. There was a significant correlation between mMRC score and the number of segmental perfusion defects (r = 0.511, p < 0.001), and a weaker correlation with DLCO (r = -0.333, p = 0.002) and KCO (r = -0.373, p = 0.001) at FU. Neither corticosteroid therapy nor HRCT results showed an influence on Q-SPECT/CT changes (p = 0.94, p = 0.74). CRP, D-Dimers and ferritin improved but did not show any association with the FU Q-SPECT/CT results (p = 0.08).

CONCLUSION

Segmental mismatched perfusion defects are common in severe COVID-19 and are correlated with the degree of dyspnea. Longitudinal analyses of Q-SPECT/CT scans in severe COVID-19 may help understand possible mechanisms of long COVID and prolonged dyspnea.

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

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

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.

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.

Poly (ADP-ribose) polymerase 1 and neurodegenerative diseases: Past, present, and future

Poly (ADP-ribose) polymerase 1 (PARP1) is a first responder that recognizes DNA damage and facilitates its repair. Neurodegenerative diseases, characterized by progressive neuron loss driven by various risk factors, including DNA damage, have increasingly shed light on the pivotal involvement of PARP1. During the early phases of neurodegenerative diseases, PARP1 experiences controlled activation to swiftly address mild DNA damage, thereby contributing to maintain brain homeostasis. However, in late stages, exacerbated PARP1 activation precipitated by severe DNA damage exacerbates the disease condition. Consequently, inhibition of PARP1 overactivation emerges as a promising therapeutic approach for neurodegenerative diseases. In this review, we comprehensively synthesize and explore the multifaceted role of PARP1 in neurodegenerative diseases, with a particular emphasis on its over-activation in the aggregation of misfolded proteins, dysfunction of the autophagy-lysosome pathway, mitochondrial dysfunction, neuroinflammation, and blood-brain barrier (BBB) injury. Additionally, we encapsulate the therapeutic applications and limitations intrinsic of PARP1 inhibitors, mainly including limited specificity, intricate pathway dynamics, constrained clinical translation, and the heterogeneity of patient cohorts. We also explore and discuss the potential synergistic implementation of these inhibitors alongside other agents targeting DNA damage cascades within neurodegenerative diseases. Simultaneously, we propose several recommendations for the utilization of PARP1 inhibitors within the realm of neurodegenerative disorders, encompassing factors like the disease-specific roles of PARP1, combinatorial therapeutic strategies, and personalized medical interventions. Lastly, the encompassing review presents a forward-looking perspective along with strategic recommendations that could guide future research endeavors in this field.

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 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.

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.

Renal artery infarction in the SARS-Cov-2 era: A systematic review of case reports

AIM

Renal artery infarction (RI) is the presence of blood clot in the main renal artery or its branches causing complete or partial obstruction of the blood supply. Its etiology is either related with disorders of the renal vasculature or with cardiovascular diseases. Recently, the SARSCoV- 2 virus is an emerging cause of thromboembolic events and the incidence of RI is anticipated to increase after the pandemic.

METHODS

A systematic review based on COVID-19 associated RI was conducted.

PROTOCOL

A systematic review of the Medline/Pubmed and Scopus databases was conducted in accordance to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (the PRISMA statement). Search strategy and information sources: A hand-search was performed using the terms "SARS-Cov-2" OR "COVID-19" AND "renal thrombosis" OR "renal infarction" OR "renal "thromboembolism".

ELIGIBILITY CRITERIA

all types of publications (case reports, case series, letters to the editor, short communications) were evaluated for relevance. Inclusion criteria were: confirmed SARS-Cov-2 infection irrespectively of the age, diagnosis of RI during or after the onset of viral infection, and exclusion of other potential causes of thromboembolic event except of SARS-Cov-2. Patients with renal transplantation were also considered. Study criteria selection: after checking for relevance based on the title and the abstract, the full texts of the selected papers were retrieved and were further evaluated. Duplicated and irrelevant cases were excluded. Any disagreement was resolved by consensus with the involvement of a third reviewer. Quality of studies: The assessment of the quality case reports was based on four different domains: selection, ascertainment, casualty and reporting. Each paper was classified as "Good", "Moderate" and "Poor" for any of the four domains. Data extractions: Crucial data for the conduct of the study were extracted including: age, sex, time from SARS-Cov-2 infection till RI development, medical history, previous or current antithrombotic protection or treatment, laterality and degree of obstruction, other sites of thromboembolism, treatment for thromboembolism and SARS-Cov-2 and final outcome.

DATA ANALYSIS

methods of descriptive statistics were implicated for analysis and presentation of the data.

RESULTS

The systematic review retrieved 35 cases in 33 reports. In most cases, RI was diagnosed within a month from the SARSCov- 2 infection albeit 17 out of 35 patients were receiving or had recently received thromboprophylaxis. Right, left, bilateral and allograft obstruction was diagnosed in 7, 15, 8 and 5 patients respectively. 17 cases experienced additional extrarenal thromboembolism primarily in aorta, spleen, brain and lower limbs. Low molecular weight heparins (LMWH) (usually 60-80 mg enoxaparine bid) was the primary treatment, followed by combinations of unfractionated heparin and salicylic acid, apixaban and rivaraxaban, warfarin, acenocoumarol or clopidogrel. Kidney replacement therapy was offered to five patients while invasive therapies with thrombus aspiration or catheter directed thrombolysis were performed in two. Regarding the outcomes, five of the patients died. The total renal function was preserved in 17 cases and renal impairment with or without hemodialysis was recorded in 5 patients, two of them having lost their kidney allografts.

LIMITATIONS

The majority of included studies are of moderate quality. The results and the conclusions are based on case-reports only and crucial data are dissimilarly presented or missing through the relevant publications.

CONCLUSIONS

Thromboprophylaxis may not offer adequate protection against SARS-Cov-2 induced thrombosis. Most patients could be effectively treated with conservative measures, while in more severe cases aggressive treatment could be recommended.

IMPLICATIONS OF KEY FINDINGS

Therapeutic doses of LMWH could be considered for protection against RI in SARS-Cov-2 cases. Interventional treatment could be offered in a minority of more severe cases after carful balancing the risks and benefits.

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.

From Emergence to Endemicity: A Comprehensive Review of COVID-19

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), later renamed coronavirus disease 2019 (COVID-19), was first identified in Wuhan, China, in early December 2019. Initially, the China office of the World Health Organization was informed of numerous cases of pneumonia of unidentified etiology in Wuhan, Hubei Province at the end of 2019. This would subsequently result in a global pandemic with millions of confirmed cases of COVID-19 and millions of deaths reported to the WHO. We have analyzed most of the data published since the beginning of the pandemic to compile this comprehensive review of SARS-CoV-2. We looked at the core ideas, such as the etiology, epidemiology, pathogenesis, clinical symptoms, diagnostics, histopathologic findings, consequences, therapies, and vaccines. We have also included the long-term effects and myths associated with some therapeutics of COVID-19. This study presents a comprehensive assessment of the SARS-CoV-2 virology, vaccines, medicines, and significant variants identified during the course of the pandemic. Our review article is intended to provide medical practitioners with a better understanding of the fundamental sciences, clinical treatment, and prevention of COVID-19. As of May 2023, this paper contains the most recent data made accessible.

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.

Uncertainties about the roles of anticoagulation and microclots in postacute sequelae of severe acute respiratory syndrome coronavirus 2 infection

Three years after the start of the pandemic, approaches to the prevention and treatment of acute COVID-19 have been established. However, postacute sequelae of SARS-CoV-2 infection (PASC) is now the focus of current investigations searching for the etiology of the symptoms and developing diagnostic and treatment strategies, as up to 10% of those with acute COVID-19 will go on to develop PASC, a significant public health burden. Some have suggested that ongoing microvascular thrombosis and microclots may play a role in the persistent sequelae of COVID-19 infection. Treatments are being given to address the presumed role of thrombosis in PASC, and some suggest that randomized controlled trials of anticoagulants in patients with PASC should be performed. In this Forum article, we focus on findings from patients with PASC that have led to the suggestion of using anticoagulants and discuss alternative considerations.