Biomarkers for the prediction of venous thromboembolism in critically ill COVID-19 patients

Vitamin D level in COVID-19 patients has positive correlations with autophagy and negative correlations with disease severity

Background and Objectives

There is still incomplete understanding of the pathogenesis of COVID-19. Calcitriol, the main form of vitamin D in serum, regulates immune responses and increases resistance to pathogens, but the mechanism by which it protects against COVID-19 is uncertain. Autophagy has antiviral effects and helps to maintain homeostasis, but its specific role in COVID-19 is also uncertain. Both vitamin D and autophagy have important functions in the lung microenvironment. This study examined the relationship of serum vitamin D and autophagy-related proteins in patients with COVID-19 and evaluated their potential use as biomarkers.

Methods

Blood samples from COVID-19 patients at the Second Hospital of Jilin University were collected. The levels of vitamin D, autophagy-related proteins (Becline 1 [BECN1] and autophagy-related 7 [ATG7]), and inflammatory markers (TNF-α and IL-1β) were measured using enzyme-linked immunosorbent assays.

Results

We examined 25 patients with mild/moderate COVID-19 and 27 patients with severe/critical COVID-19. The group with severe/critical COVID-19 had more abnormalities in many laboratory indicators, including lower levels of autophagy markers (BECN1 and ATG7) and vitamin D, and higher levels of inflammatory markers (TNF-α and IL-1β). Partial correlation analysis showed that vitamin D had strong positive correlations with ATG7 (r = 0.819, p < 0.001) and BECN1 (r = 0.900, p < 0.001).

Conclusion

Our results demonstrated that the vitamin D level had significant negative correlations with COVID-19 severity and strong positive correlations with autophagy. These findings enhance our understanding of the pathogenesis of COVID-19, and provide a theoretical basis for clinical interventions that target autophagy and vitamin D.

TIME-DEPENDENT CHANGES IN PROINFLAMMATORY MEDIATORS ARE ASSOCIATED WITH TRAUMA-RELATED VENOUS THROMBOEMBOLISM

ABSTRACT

Background: Tissue trauma and hemorrhage result in pronounced activation of the innate immune system. Given known crosstalk between inflammation and coagulation, soluble inflammatory mediators could be associated with venous thromboembolisms (VTEs) after major trauma. Objectives : This study aimed to identify plasma inflammatory mediators that are independent predictors of VTE risk in trauma patients. Methods: We performed a secondary analysis of the Pragmatic Randomized Optimal Platelets and Plasma Ratios (PROPPR) study. Plasma levels of 27 cytokines/chemokines were measured by Bio-Plex at admission and 2, 4, 6, 12, 24, 48, and 72 h later. Patients who died from exsanguination or within 24 h were excluded. Mann-Whitney tests were performed to assess no-VTE and VTE groups at each time point. Multivariable logistic regression was used to determine the adjusted effects of inflammatory mediators on VTE risk. Results: Eighty-six of the 575 patients (15%) included developed VTE. Interleukin (IL)-1ra, IL-6, IL-8, IL-10, eotaxin, granulocyte colony-stimulating factor, interferon-γ-inducible protein, monocyte chemoattractant protein 1 (MCP-1), and chemokine ligand 5 (regulated on activation, normal T cell expressed and secreted) were all significantly increased among VTE patients. Multivariable analyses demonstrated that IL-6, IL-8, interferon-γ-inducible protein, and MCP-1 were independently associated with VTE. Cox proportional hazards modeling identified IL-6, IL-8, and MCP-1 as independent predictors of accelerated VTE development. We identified significant correlations between inflammation and markers of coagulation and endothelial activation. Conclusion: Sustained systemic inflammation is a key driver of VTE risk after major trauma. Therapeutics targeting innate immune activation should be considered for development of future multimodal strategies to augment current VTE prophylaxis.

NLRP3 inflammasome and interleukin-1 contributions to COVID-19-associated coagulopathy and immunothrombosis

Immunothrombosis-immune-mediated activation of coagulation-is protective against pathogens, but excessive immunothrombosis can result in pathological thrombosis and multiorgan damage, as in severe coronavirus disease 2019 (COVID-19). The NACHT-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome produces major proinflammatory cytokines of the interleukin (IL)-1 family, IL-1β and IL-18, and induces pyroptotic cell death. Activation of the NLRP3 inflammasome pathway also promotes immunothrombotic programs including release of neutrophil extracellular traps and tissue factor by leukocytes, and prothrombotic responses by platelets and the vascular endothelium. NLRP3 inflammasome activation occurs in patients with COVID-19 pneumonia. In preclinical models, NLRP3 inflammasome pathway blockade restrains COVID-19-like hyperinflammation and pathology. Anakinra, recombinant human IL-1 receptor antagonist, showed safety and efficacy and is approved for the treatment of hypoxaemic COVID-19 patients with early signs of hyperinflammation. The non-selective NLRP3 inhibitor colchicine reduced hospitalization and death in a subgroup of COVID-19 outpatients but is not approved for the treatment of COVID-19. Additional COVID-19 trials testing NLRP3 inflammasome pathway blockers are inconclusive or ongoing. We herein outline the contribution of immunothrombosis to COVID-19-associated coagulopathy, and review preclinical and clinical evidence suggesting an engagement of the NLRP3 inflammasome pathway in the immunothrombotic pathogenesis of COVID-19. We also summarize current efforts to target the NLRP3 inflammasome pathway in COVID-19, and discuss challenges, unmet gaps, and the therapeutic potential that inflammasome-targeted strategies may provide for inflammation-driven thrombotic disorders including COVID-19.

Temporal evolution of laboratory characteristics in patients critically ill with COVID‑19 admitted to the intensive care unit (Review)

In the context of coronavirus disease 2019 (COVID-19), laboratory medicine has played a crucial role in both diagnosis and severity assessment. Although the importance of baseline laboratory findings has been extensively reported, data regarding their evolution over the clinical course are limited. The aim of the present narrative review was to provide the dynamic changes of the routine laboratory variables reported in patients with severe COVID-19 over the course of their critical illness. A search was made of the literature for articles providing data on the time-course of routine laboratory tests in patients with severe COVID-19 during their stay in the intensive care unit (ICU). White blood cell, neutrophil and lymphocyte counts, neutrophil to lymphocyte ratio, platelet counts, as well as D-dimer, fibrinogen, C-reactive protein, lactate dehydrogenase and serum albumin levels were selected as disease characteristics and routine laboratory parameters. A total of 25 research articles reporting dynamic trends in the aforementioned laboratory parameters over the clinical course of severe COVID-19 were identified. During the follow-up period provided by each study, the majority of the laboratory values remained persistently abnormal in both survivors and non-survivors. Furthermore, in the majority of studies, the temporal trends of laboratory values distinctly differentiated patients between survivors and non-survivors. In conclusion, there are distinct temporal trends in selected routine laboratory parameters between survivors and non-survivors with severe COVID-19 admitted to the ICU, indicating their importance in the prognosis of clinical outcome.

Predictors of pulmonary embolism in hospitalized patients with COVID-19

BACKGROUND

High venous thromboembolism (VTE) rates have been described in critically ill patients with COVID-19. We hypothesized that specific clinical characteristics may help differentiate hypoxic COVID-19 patients with and without a diagnosed pulmonary embolism (PE).

METHODS

We performed a retrospective observational case-control study of 158 consecutive patients hospitalized in one of four Mount Sinai Hospitals with COVID-19 between March 1 and May 8, 2020, who received a Chest CT Pulmonary Angiogram (CTA) to diagnose a PE. We analyzed demographic, clinical, laboratory, radiological, treatment characteristics, and outcomes in COVID-19 patients with and without PE.

RESULTS

92 patients were negative (CTA-), and 66 patients were positive for PE (CTA+). CTA + had a longer time from symptom onset to admission (7 days vs. 4 days, p = 0.05), higher admission biomarkers, notably D-dimer (6.87 vs. 1.59, p < 0.0001), troponin (0.015 vs. 0.01, p = 0.01), and peak D-dimer (9.26 vs. 3.8, p = 0.0008). Predictors of PE included time from symptom onset to admission (OR = 1.11, 95% CI 1.03-1.20, p = 0.008), and PESI score at the time of CTA (OR = 1.02, 95% CI 1.01-1.04, p = 0.008). Predictors of mortality included age (HR 1.13, 95% CI 1.04-1.22, p = 0.006), chronic anticoagulation (13.81, 95% CI 1.24-154, p = 0.03), and admission ferritin (1.001, 95% CI 1-1.001, p = 0.01).

CONCLUSIONS

In 158 hospitalized COVID-19 patients with respiratory failure evaluated for suspected PE, 40.8% patients had a positive CTA. We identified clinical predictors of PE and mortality from PE, which may help with early identification and reduction of PE-related mortality in patients with COVID-19.

Assessment and Monitoring of Coagulation in Patients with COVID-19: A Review of Current Literature

Coagulation abnormalities are common in patients with COVID-19 and associated with high morbidity and mortality. It became a daily challenge to navigate through these abnormal laboratory findings and deliver the best possible treatment to the patients. The unique character of COVID-19-induced coagulopathy necessitates not only a dynamic follow-up of the patients in terms of hemostatic findings but also the introduction of new diagnostic methods to determine the overall function of the coagulation system in real time. After the recognition of the high risk of thromboembolism in COVID-19, several professional societies published their recommendations regarding anticoagulation in patients with COVID-19. This review summarizes common hemostatic findings in COVID-19 patients and presents the societal recommendations regarding the use of coagulation laboratory findings in clinical decision-making. Although several studies have investigated coagulation parameters in patients with COVID-19, the methodological shortcomings of published studies as well as the differences in employed anticoagulation regimens that have changed over time, depending on national and international guidelines, limit the applicability of these findings in other clinical settings. Accordingly, evidence-based recommendations for diagnostics during acute COVID-19 infection are still lacking. Future studies should verify the role of coagulation parameters as well as viscoelastic methods in the management of patients with COVID-19.

Approach to Thromboprophylaxis for Prevention of Venous Thromboembolism in COVID-19: Global Updates and Clinical Insights from India

Venous thromboembolism (VTE) frequently occurs in patients with coronavirus disease-19 (COVID-19) and is associated with increased mortality. Several global guidelines recommended prophylactic-intensity anticoagulation rather than intermediate-intensity or therapeutic-intensity anticoagulation for patients with COVID-19-related acute or critical illness without suspected or confirmed VTE. Even though standard doses of thromboprophylaxis are received, many cases of thrombotic complications are reported; hence, appropriate and adequate thromboprophylaxis is critical for the prevention of VTE in COVID-19. In spite of an increased prevalence of VTE in Indian patients, sufficient data on patient characteristics, diagnosis, and therapeutic approach for VTE in COVID is lacking. In this article, we review the available global literature (search conducted up to 31 May 2021) and provide clinical insights into our approach towards managing VTE in patients with COVID-19. Furthermore, in this review, we summarize the incidence and risk factors for VTE with emphasis on the thromboprophylaxis approach in hospitalized patients and special populations with COVID-19 and assess clinical implications in the Indian context.

C-reactive protein, immunothrombosis and venous thromboembolism

C-reactive protein (CRP) is a member of the highly conserved pentraxin superfamily of proteins and is often used in clinical practice as a marker of infection and inflammation. There is now increasing evidence that CRP is not only a marker of inflammation, but also that destabilized isoforms of CRP possess pro-inflammatory and pro-thrombotic properties. CRP circulates as a functionally inert pentameric form (pCRP), which relaxes its conformation to pCRP* after binding to phosphocholine-enriched membranes and then dissociates to monomeric CRP (mCRP). with the latter two being destabilized isoforms possessing highly pro-inflammatory features. pCRP* and mCRP have significant biological effects in regulating many of the aspects central to pathogenesis of atherothrombosis and venous thromboembolism (VTE), by directly activating platelets and triggering the classical complement pathway. Importantly, it is now well appreciated that VTE is a consequence of thromboinflammation. Accordingly, acute VTE is known to be associated with classical inflammatory responses and elevations of CRP, and indeed VTE risk is elevated in conditions associated with inflammation, such as inflammatory bowel disease, COVID-19 and sepsis. Although the clinical data regarding the utility of CRP as a biomarker in predicting VTE remains modest, and in some cases conflicting, the clinical utility of CRP appears to be improved in subsets of the population such as in predicting VTE recurrence, in cancer-associated thrombosis and in those with COVID-19. Therefore, given the known biological function of CRP in amplifying inflammation and tissue damage, this raises the prospect that CRP may play a role in promoting VTE formation in the context of concurrent inflammation. However, further investigation is required to unravel whether CRP plays a direct role in the pathogenesis of VTE, the utility of which will be in developing novel prophylactic or therapeutic strategies to target thromboinflammation.

Clinical utility of circulating calprotectin to assist prediction and monitoring of COVID-19 severity: An Italian study

BACKGROUND

Calprotectin (S100A8/A9) has been identified as a biomarker that can aid in predicting the severity of disease in COVID-19 patients. This study aims to evaluate the correlation between levels of circulating calprotectin (cCP) and the severity of COVID-19.

METHODS

Sera from 245 COVID-19 patients and 110 apparently healthy individuals were tested for calprotectin levels using a chemiluminescent immunoassay (Inova Diagnostics). Intensive care unit (ICU) admission and type of respiratory support administered were used as indicators of disease severity, and their correlation with calprotectin levels was assessed.

RESULTS

Samples from patients in the ICU had a median calprotectin concentration of 11.6 µg/ml as compared to 3.5 µg/ml from COVID-19 patients who were not in the ICU. The median calprotectin concentration in a cohort of healthy individuals collected before the COVID-19 pandemic was 3.0 µg/ml (95% CI: 2.820-2.969 µg/ml). Patients requiring a Venturi mask, continuous positive airway pressure, or orotracheal intubation all had significantly higher values of calprotectin than controls, with the increase of cCP levels proportional to the increasing need of respiratory support.

CONCLUSION

Calprotectin levels in serum correlate well with disease severity and represent a promising serological biomarker for the risk assessment of COVID-19 patients.

Soluble urokinase Plasminogen Activator Receptor (suPAR) levels are predictive of COVID-19 severity: An Italian experience

Background

The soluble urokinase Plasminogen Activator Receptor (suPAR) has been identified as a reliable marker of COVID-19 severity, helping in personalizing COVID-19 therapy. This study aims to evaluate the correlation between suPAR levels and COVID-19 severity, in relation to the traditional inflammatory markers.

Methods

Sera from 71 COVID-19 patients were tested for suPAR levels using Chorus suPAR assay (Diesse Diagnostica Senese SpA, Italy). suPAR levels were compared with other inflammatory markers: IL-1β, IL-6, TNF-α, circulating calprotectin, neutrophil and lymphocyte counts, and Neutrophil/Lymphocytes Ratio (NLR). Respiratory failure, expressed as P/F ratio, and mortality rate were used as indicators of disease severity.

Results

A positive correlation of suPAR levels with IL-6 (r = 0.479, p = 0.000), TNF-α (r = 0.348, p = 0.003), circulating calprotectin (r = 0.369, p = 0.002), neutrophil counts (r = 0.447, p = 0.001), NLR (r = 0.492, p = 0.001) has been shown. Stratifying COVID-19 population by suPAR concentration above and below 6 ng/mL, we observed higher levels of circulating calprotectin (10.1 μg/mL, SD 7.9 versus 6.4 μg/mL, SD 7.5, p < 0.001), higher levels of P/F ratio (207.5 IQR 188.3 vs 312.0 IQR 127.8, p = 0.013) and higher mortality rate. Median levels of suPAR were increased in all COVID-19 patients requiring additional respiratory support (Nasal Cannula, Venturi Mask, BPAP and CPAP) (6.5 IQR = 4.9) compared to the group at room air (4.6 IQR = 4.2).

Conclusion

suPAR levels correlate with disease severity and survival rate of COVID-19 patients, representing a promising prognostic biomarker for the risk assessment of the disease.

Rotational thromboelastometry in critically ill COVID-19 patients does not predict thrombosis

Background

Critically ill COVID‐19 patients are in a hypercoagulable state with increased risk of thrombotic complications. Rotational thromboelastometry (ROTEM) is a viscoelastic test with the potential to reflect COVID‐19‐associated hypercoagulability and may therefore be useful to predict thrombotic complications.

Objective

To investigate the potential of ROTEM profiles to predict thrombotic complications in critically ill COVID‐19 patients.

Patients/Methods

Retrospective multicenter cohort study in 113 adult patients with confirmed COVID‐19 infection admitted to the intensive care unit (ICU) of two large teaching hospitals in the United States and in the Netherlands. ROTEM profiles of the EXTEM, INTEM, and FIBTEM tracings were measured within 72 h of ICU admission. Thrombotic complications encompass both arterial and venous thromboembolic complications, diagnosed with electrocardiogram, ultrasound, or computed tomography. ROTEM profiles were compared between patients with and without thrombosis. Univariable logistic regression followed by receiver operating characteristic (ROC) curves analysis was performed to identify ROTEM parameters associated with thrombosis.

Results and Conclusions

Of 113 patients, 27 (23.9%) developed a thrombotic event. In the univariable analysis, EXTEM clot amplitude at 10 min (CA10) and EXTEM maximum clot formation (MCF) were associated with thrombosis with a p < 0.2 (p = 0.07 and p = 0.05, respectively). In ROC curve analysis, EXTEM CA10 had an area under the curve (AUC) of 0.58 (95% CI 0.47–0.70) and EXTEM MCF had an AUC of 0.60 (95% CI 0.49–0.71). Thereby, ROTEM profiles at ICU admission did not have the potential to differentiate between patients with a high and low risk for thrombotic complications.

Thromboprophylaxis for children hospitalized with COVID-19 and MIS-C

Background

Limited data exist about effective regimens for pharmacological thromboprophylaxis in children with acute coronavirus disease 2019 (COVID‐19) and multisystem inflammatory syndrome in children (MIS‐C).

Objectives

Study the outcomes of institutional thromboprophylaxis protocol for primary venous thromboembolism (VTE) prevention in children hospitalized with acute COVID‐19/MIS‐C.

Methods

This single‐center retrospective cohort study included consecutive children (aged less than 21 years) with COVID‐19/MIS‐C who received tailored intensity thromboprophylaxis, primarily with low‐molecular‐weight heparin, from April 2020 through October 2021. Thromboprophylaxis was given to those with moderate to severe disease based on the World Health Organization scale and exposure to two or more VTE risk factors. Therapeutic intensity was considered for severe illness. Clinical recovery along with D‐dimer improvement determined thromboprophylaxis duration. Outcomes were incident VTEs, bleeding, and mortality.

Results

Among 211 hospitalizations, 45 (21.3%) received thromboprophylaxis (COVID‐19, 16; MIS‐C, 29). Median age was 14.8 years (interquartile range [IQR], 8.9–16.1). Among 35 (77.8%) with severe illness, 27 (60.0%) required respiratory support, and 19 (42.2%) required an intensive care unit stay. Median hospitalization was 6 days (IQR, 5.0–10.5). Median thromboprophylaxis duration was 19 days (IQR, 6.0–31.0) with therapeutic intensity in 24 (53.3%) and prophylactic in 21 (46.7%). Outcomes were as follows: VTE, 1 (2.2%); death, 1 (2.2%, unrelated to bleeding/thrombosis); major/clinically relevant nonmajor bleeding, 0; and minor bleeding, 7 (15.5%). D‐dimer was elevated in a majority at diagnosis (median, 2.3; IQR, 1.2–3.3 mg/ml fibrinogen‐equivalent units) and was noninformative in assessing disease severity. D‐dimer normalized at thromboprophylaxis discontinuation.

Conclusions

Our experience of using clinically directed thromboprophylaxis with tailored intensity approach for children hospitalized with COVID‐19 and MIS‐C favors its inclusion in current standard of care. The role of D‐dimer in directing thromboprophylaxis management deserves further evaluation.

Biomarker derived risk scores predict venous thromboembolism and major bleeding among patients with COVID-19

Background

Venous thromboembolism (VTE) risk is increased in patients with COVID‐19 infection. Understanding which patients are likely to develop VTE may inform pharmacologic VTE prophylaxis decision making. The hospital‐associated venous thromboembolism–Intermountain Risk Score (HA‐VTE IMRS) and the hospital‐associated major bleeding–Intermountain Risk Score (HA‐MB IMRS) are risk scores predictive of VTE and bleeding that were derived from only patient age and data found in the complete blood count (CBC) and basic metabolic panel (BMP).

Objectives

We assessed the HA‐VTE IMRS and HA‐MB IMRS for predictiveness of 90‐day VTE and major bleeding, respectively, among patients diagnosed with COVID‐19, and further investigated if adding D‐dimer improved these predictions. We also reported 30‐day outcomes.

Patients/Methods

We identified 5047 sequential patients with a laboratory confirmed diagnosis of COVID‐19 and a CBC and BMP between 2 days before and 7 days following the diagnosis of COVID‐19 from March 12, 2020, to February 28, 2021. We calculated the HA‐VTE IMRS and the HA‐MB IMRS for all patients. We assessed the added predictiveness of D‐dimer obtained within 48 hours of the COVID test.

Results

The HA‐VTE IMRS yielded a c‐statistic of 0.70 for predicting 90‐day VTE and adding D‐dimer improved the c‐statistic to 0.764 with the corollary sensitivity/specificity/positive/negative predictive values of 49.4%/75.7%/6.7%/97.7% and 58.8%/76.2%/10.9%/97.4%, respectively. Among hospitalized and ambulatory patients separately, the HA‐VTE IMRS performed similarly. The HA‐MB IMRS predictiveness for 90‐day major bleeding yielded a c‐statistic of 0.64.

Conclusion

The HA‐VTE IMRS and HA‐MB IMRS predict 90‐ and 30‐day VTE and major bleeding among COVID‐19 patients. Adding D‐dimer improved the predictiveness of the HA‐VTE IMRS for VTE.

Blockchain Assisted Disease Identification of COVID-19 Patients with the Help of IDA-DNN Classifier

Globally, millions of people were affected by the Corona-virus disease-2019 (COVID-19) causing loads of deaths. Most COVID-19 affected people recover in a few spans of weeks. However, certain people even those with a milder variant of the disease persist in experiencing symptoms subsequent to their initial recuperation. Here, a novel Block-Chain (BC)-assisted optimized deep learning algorithm, explicitly improved dragonfly algorithm based Deep Neural Network (IDA-DNN), is proposed for detecting the different diseases of the COVID-19 patients. Initially, the input data of the COVID-19 recovered patients are gathered centered on their post symptoms and their data is amassed as a BC for rendering security to the patient's data. After that, the disease identification of the patient's data is performed with the aid of system training. The training includes '4' disparate datasets for data collection, and then, performs preprocessing, Feature Extraction (FE), Feature Reduction (FR), along with classification utilizing ID-DNN on the gathered inputted data. The IDA-DNN classifies '2' classes (presence of disease and absence of disease) for every type of data. The proposed method's outcomes are examined as well as contrasted with the other prevailing techniques to corroborate that the proposed IDA-DNN detects the COVID-19 more efficiently.

The Role of Biomarkers in Hospitalized COVID-19 Patients With Systemic Manifestations

The following article aims to review COVID-19 biomarkers used in hospital practice. It is apparent that COVID-19 is not simply a pulmonary disease but has systemic manifestations. For this reason, biomarkers must be used in the management of diagnosed patients to provide holistic care. Patients with COVID-19 have been shown to have pulmonary, hepatobiliary, cardiovascular, neurologic, and renal injury, along with coagulopathy and a distinct cytokine storm. Biomarkers can effectively inform clinicians of systemic organ injury due to COVID-19. Furthermore, biomarkers can be used in predictive models for severe COVID-19 in admitted patients. The utility of doing so is to allow for risk stratification and utilization of proper treatment protocols. In addition, COVID-19 biomarkers in the pediatric population are discussed, specifically in predicting Multisystem Inflammatory Syndrome. Ultimately, biomarkers can be used as predictive tools to allow clinicians to identify and adequately manage patients at increased risk for worse outcomes from COVID-19. Both literature review and anecdotal evidence has shown that severe COVID-19 is a systemic disease, and understanding associated biomarkers are crucial for hospitalized patients’ proper clinical decision-making. For example, the cytokine storm releases inflammatory markers in different organ systems such as the pulmonary, hepatobiliary, hematological, cardiac, neurological, and renal systems. This review summarizes the latest research of COVID-19 that can help inform healthcare professionals how to better mitigate morbidity and mortality associated with this disease and provides information about certain systemic biomarkers that can be incorporated into hospital practice to provide more comprehensive care for hospitalized COIVD-19 patients.

Diagnostic Accuracy of Liquid Biomarkers in Airway Diseases: Toward Point-of-Care Applications

Background

Liquid biomarkers have shown increasing utility in the clinical management of airway diseases. Salivary and blood samples are particularly amenable to point-of-care (POC) testing due to simple specimen collection and processing. However, very few POC tests have successfully progressed to clinical application due to the uncertainty and unpredictability surrounding their diagnostic accuracy.

Objective

To review liquid biomarkers of airway diseases with well-established diagnostic accuracies and discuss their prospects for future POC applications.

Methodology

A literature review of publications indexed in Medline or Embase was performed to evaluate the diagnostic accuracy of liquid biomarkers for chronic obstructive pulmonary disease (COPD), asthma, laryngopharyngeal reflux (LPR), and COVID-19.

Results

Of 3,628 studies, 71 fulfilled the inclusion criteria. Sputum and blood eosinophils were the most frequently investigated biomarkers for the management of asthma and COPD. Salivary pepsin was the only biomarker with a well-documented accuracy for the diagnosis of LPR. Inflammatory blood biomarkers (e.g., CRP, D-dimers, ferritin) were found to be useful to predict the severity, complications, and mortality related to COVID-19 infection.

Conclusion

Multiple liquid biomarkers have well-established diagnostic accuracies and are thus amenable to POC testing in clinical settings.

Venous thromboembolism in COVID-19 patients and prediction model: a multicenter cohort study

Background

Patients with COVID-19 infection are commonly reported to have an increased risk of venous thrombosis. The choice of anti-thrombotic agents and doses are currently being studied in randomized controlled trials and retrospective studies. There exists a need for individualized risk stratification of venous thromboembolism (VTE) to assist clinicians in decision-making on anticoagulation. We sought to identify the risk factors of VTE in COVID-19 patients, which could help physicians in the prevention, early identification, and management of VTE in hospitalized COVID-19 patients and improve clinical outcomes in these patients.

Method

This is a multicenter, retrospective database of four main health systems in Southeast Michigan, United States. We compiled comprehensive data for adult COVID-19 patients who were admitted between 1st March 2020 and 31st December 2020. Four models, including the random forest, multiple logistic regression, multilinear regression, and decision trees, were built on the primary outcome of in-hospital acute deep vein thrombosis (DVT) and pulmonary embolism (PE) and tested for performance. The study also reported hospital length of stay (LOS) and intensive care unit (ICU) LOS in the VTE and the non-VTE patients. Four models were assessed using the area under the receiver operating characteristic curve and confusion matrix.

Results

The cohort included 3531 admissions, 3526 had discharge diagnoses, and 6.68% of patients developed acute VTE (N = 236). VTE group had a longer hospital and ICU LOS than the non-VTE group (hospital LOS 12.2 days vs. 8.8 days, p < 0.001; ICU LOS 3.8 days vs. 1.9 days, p < 0.001). 9.8% of patients in the VTE group required more advanced oxygen support, compared to 2.7% of patients in the non-VTE group (p < 0.001). Among all four models, the random forest model had the best performance. The model suggested that blood pressure, electrolytes, renal function, hepatic enzymes, and inflammatory markers were predictors for in-hospital VTE in COVID-19 patients.

Conclusions

Patients with COVID-19 have a high risk for VTE, and patients who developed VTE had a prolonged hospital and ICU stay. This random forest prediction model for VTE in COVID-19 patients identifies predictors which could aid physicians in making a clinical judgment on empirical dosages of anticoagulation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07421-3.

Plasma D-dimer value corrected by inflammatory markers in patients with SARS-CoV-2 infection: Its prognostic value in the diagnosis of venous thromboembolism

INTRODUCTION

D-dimer levels are elevated in COVID 19 and they correlate to the levels of other inflammatory markers such us ferritin, fibrinogen and C-reactive protein. It may be possible to correct D-dimer value in function of inflammatory markers, thus identifying patients at higher risk of venous thromboembolism (VTE). Our objectives are estimating a corrected value of plasma D-dimer as a linear function of ferritin, C-reactive protein and fibrinogen and stablishing a cut-off point of high probability of VTE.

PATIENTS AND METHODS

Age and sex matched case-control study of all patients diagnosed with COVID 19 and VTE between March and May 2020 in a tertiary hospital in Madrid (Spain). Using linear regression, the best predictive model will be estimated and residual D-dimer values will be obtained and analyzed using ROC curves to determine its discriminative performance.

RESULTS

Thirty-eight cases and seventy-six controls were included. There was 63.2% of men and mean age was 68.2. D-dimer was best predicted by a linear model including fibrinogen, ferritin and C-reactive protein. Using residual values, the optimal cutoff point was 2165ng/mL, with a sensitivity of 57.9% and specificity of 98.7%.

CONCLUSION

It is possible to estimate a D-dimer corrected value in function of ferritin, C-reactive protein and fibrinogen. Using the observed and estimated value we can obtain a residual value that performs well as a screening method to detect patients who would benefit for further VTE diagnostic testing.

Plasma D-dimer value corrected by inflammatory markers in patients with SARS-CoV-2 infection: Its prognostic value in the diagnosis of venous thromboembolism

Introduction

D-dimer levels are elevated in COVID 19 and they correlate to the levels of other inflammatory markers such us ferritin, fibrinogen and C-reactive protein. It may be possible to correct D-dimer value in function of inflammatory markers, thus identifying patients at higher risk of venous thromboembolism (VTE). Our objectives are estimating a corrected value of plasma D-dimer as a linear function of ferritin, C-reactive protein and fibrinogen and stablishing a cut-off point of high probability of VTE.

Patients and methods

Age and sex matched case-control study of all patients diagnosed with COVID 19 and VTE between March and May 2020 in a tertiary hospital in Madrid (Spain). Using linear regression, the best predictive model will be estimated and residual D-dimer values will be obtained and analyzed using ROC curves to determine its discriminative performance.

Results

Thirty-eight cases and seventy-six controls were included. There was 63.2% of men and mean age was 68.2. D-dimer was best predicted by a linear model including fibrinogen, ferritin and C-reactive protein. Using residual values, the optimal cutoff point was 2165 ng/mL, with a sensitivity of 57.9% and specificity of 98.7%.

Conclusion

It is possible to estimate a D-dimer corrected value in function of ferritin, C-reactive protein and fibrinogen. Using the observed and estimated value we can obtain a residual value that performs well as a screening method to detect patients who would benefit for further VTE diagnostic testing.

Association of the Intermountain Risk Score with major adverse health events in patients positive for COVID-19: an observational evaluation of a US cohort

OBJECTIVES

The Intermountain Risk Score (IMRS), composed using published sex-specific weightings of parameters in the complete blood count (CBC) and basic metabolic profile (BMP), is a validated predictor of mortality. We hypothesised that IMRS calculated from prepandemic CBC and BMP predicts COVID-19 outcomes and that IMRS using laboratory results tested at COVID-19 diagnosis is also predictive.

DESIGN

Prospective observational cohort study.

SETTING

Primary, secondary, urgent and emergent care, and drive-through testing locations across Utah and in sections of adjacent US states. Viral RNA testing for SARS-CoV-2 was conducted from 3 March to 2 November 2020.

PARTICIPANTS

Patients aged ≥18 years were evaluated if they had CBC and BMP measured in 2019 and tested positive for COVID-19 in 2020.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was a composite of hospitalisation or mortality, with secondary outcomes being hospitalisation and mortality separately.

RESULTS

Among 3883 patients, 8.2% were hospitalised and 1.6% died. Subjects with low, mild, moderate and high-risk IMRS had the composite endpoint in 3.5% (52/1502), 8.6% (108/1256), 15.5% (152/979) and 28.1% (41/146) of patients, respectively. Compared with low-risk, subjects in mild-risk, moderate-risk and high-risk groups had HR=2.33 (95% CI 1.67 to 3.24), HR=4.01 (95% CI 2.93 to 5.50) and HR=8.34 (95% CI 5.54 to 12.57), respectively. Subjects aged <60 years had HR=3.06 (95% CI 2.01 to 4.65) and HR=7.38 (95% CI 3.14 to 17.34) for moderate and high risks versus low risk, respectively; those ≥60 years had HR=1.95 (95% CI 0.99 to 3.86) and HR=3.40 (95% CI 1.63 to 7.07). In multivariable analyses, IMRS was independently predictive and was shown to capture substantial risk variation of comorbidities.

CONCLUSIONS

IMRS, a simple risk score using very basic laboratory results, predicted COVID-19 hospitalisation and mortality. This included important abilities to identify risk in younger adults with few diagnosed comorbidities and to predict risk prior to SARS-CoV-2 infection.

Thromboembolic complications during and after hospitalization for COVID-19: Incidence, risk factors and thromboprophylaxis

Introduction

The incidence of thromboembolism during COVID-19 and the use of thromboprophylaxis vary greatly between studies. Only a few studies have investigated the rate of thromboembolism post-discharge. This study determined the 90-day incidence of venous and arterial thromboembolic complications, risk factors for venous thromboembolic events and characterized the use of thromboprophylaxis during and after hospitalization.

Materials and methods

We retrospectively reviewed medical records for adult patients hospitalized for >24 h for COVID-19 before May 15, 2020, in ten Norwegian hospitals. We extracted data on demographics, thromboembolic complications, thromboembolic risk factors, and the use of thromboprophylaxis. Cox proportional hazards regression was used to determine risk factors for VTE.

Results

550 patients were included. The 90-day incidence of arterial and venous thromboembolism in hospitalized patients was 6.9% (95% CI: 5.1-9.3) overall and 13.8% in the ICU. Male sex (hazard ratio (HR) 7.44, 95% CI 1.73-32.02, p = 0.007) and previous VTE (HR 6.11, 95% CI: 1.74-21.39, p = 0.005) were associated with risk of VTE in multivariable analysis. Thromboprophylaxis was started in 334 patients (61%) with a median duration of 7 days (25th-75th percentile 3-13); in the VTE population 10/23 (43%) started thromboprophylaxis prior to diagnosis. After discharge 20/223 patients received extended thromboprophylaxis and 2/223 (0.7%, 95% CI: 0.3-1.9) had a thromboembolism.

Conclusions

The 90-day incidence of thromboembolism in COVID-19 patients was 7%, but <1% after discharge. Risk factors were male sex and previous VTE. Most patients received thromboprophylaxis during hospitalization, but only <10% after discharge.

Bronchial Aspirate-Based Profiling Identifies MicroRNA Signatures Associated With COVID-19 and Fatal Disease in Critically Ill Patients

Background

The pathophysiology of COVID-19-related critical illness is not completely understood. Here, we analyzed the microRNA (miRNA) profile of bronchial aspirate (BAS) samples from COVID-19 and non-COVID-19 patients admitted to the ICU to identify prognostic biomarkers of fatal outcomes and to define molecular pathways involved in the disease and adverse events.

Methods

Two patient populations were included (n = 89): (i) a study population composed of critically ill COVID-19 and non-COVID-19 patients; (ii) a prospective study cohort composed of COVID-19 survivors and non-survivors among patients assisted by invasive mechanical ventilation (IMV). BAS samples were obtained by bronchoaspiration during the ICU stay. The miRNA profile was analyzed using RT-qPCR. Detailed biomarker and bioinformatics analyses were performed.

Results

The deregulation in five miRNA ratios (miR-122-5p/miR-199a-5p, miR-125a-5p/miR-133a-3p, miR-155-5p/miR-486-5p, miR-214-3p/miR-222-3p, and miR-221-3p/miR-27a-3p) was observed when COVID-19 and non-COVID-19 patients were compared. In addition, five miRNA ratios segregated between ICU survivors and nonsurvivors (miR-1-3p/miR-124-3p, miR-125b-5p/miR-34a-5p, miR-126-3p/miR-16-5p, miR-199a-5p/miR-9-5p, and miR-221-3p/miR-491-5p). Through multivariable analysis, we constructed a miRNA ratio-based prediction model for ICU mortality that optimized the best combination of miRNA ratios (miR-125b-5p/miR-34a-5p, miR-199a-5p/miR-9-5p, and miR-221-3p/miR-491-5p). The model (AUC 0.85) and the miR-199a-5p/miR-9-5p ratio (AUC 0.80) showed an optimal discrimination value and outperformed the best clinical predictor for ICU mortality (days from first symptoms to IMV initiation, AUC 0.73). The survival analysis confirmed the usefulness of the miRNA ratio model and the individual ratio to identify patients at high risk of fatal outcomes following IMV initiation. Functional enrichment analyses identified pathological mechanisms implicated in fibrosis, coagulation, viral infections, immune responses and inflammation.

Conclusions

COVID-19 induces a specific miRNA signature in BAS from critically ill patients. In addition, specific miRNA ratios in BAS samples hold individual and collective potential to improve risk-based patient stratification following IMV initiation in COVID-19-related critical illness. The biological role of the host miRNA profiles may allow a better understanding of the different pathological axes of the disease.

COVID-19 and venous thromboembolism: A narrative review

COVID-19 (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) is associated with coagulopathy through numerous mechanisms. The reported incidence of venous thromboembolism (VTE) in hospitalized patients with COVID-19 has varied widely, and several meta-analyses have been performed to assess the overall prevalence of VTE. The novelty of this coronavirus strain along with its unique mechanisms for microvascular and macrovascular thrombosis has led to uncertainty as to how to diagnose, prevent, and treat thrombosis in patients affected by this virus. This review discusses the epidemiology and pathophysiology of thrombosis in the setting of SARS-CoV-2 infection along with an updated review on the preventative and treatment strategies for VTE associated with SARS-CoV-2 infection.

Risk Factors for Venous Thromboembolism in Severe COVID-19: A Study-Level Meta-Analysis of 21 Studies

Venous thromboembolism (VTE) in patients with COVID-19 in intensive care units (ICU) is frequent, but risk factors (RF) remain unidentified. In this meta-analysis (CRD42020188764) we searched for observational studies from ICUs reporting the association between VTE and RF in Medline/Embase up to 15 April 2021. Reviewers independently extracted data in duplicate and assessed the certainty of the evidence using the GRADE approach. Analyses were conducted using the random-effects model and produced a non-adjusted odds ratio (OR). We analysed 83 RF from 21 studies (5296 patients). We found moderate-certainty evidence for an association between VTE and the D-dimer peak (OR 5.83, 95%CI 3.18–10.70), and length of hospitalization (OR 7.09, 95%CI 3.41–14.73) and intubation (OR 2.61, 95%CI 1.94–3.51). We identified low-certainty evidence for an association between VTE and CRP (OR 1.83, 95% CI 1.32–2.53), D-dimer (OR 4.58, 95% CI 2.52–8.50), troponin T (OR 8.64, 95% CI 3.25–22.97), and the requirement for inotropic drugs (OR 1.67, 95% CI 1.15–2.43). Traditional VTE RF (i.e., history of cancer, previous VTE events, obesity) were not found to be associated to VTE in COVID-19. Anticoagulation was not associated with a decreased VTE risk. VTE RF in severe COVID-19 correspond to individual illness severity, and inflammatory and coagulation parameters.

The Year in Cardiothoracic and Vascular Anesthesia: Selected Highlights from 2021

This special article is the fourteenth in an annual series for the Journal of Cardiothoracic and Vascular Anesthesia. The authors thank the Editor-in-Chief, Dr. Kaplan, and the editorial board for the opportunity to continue this series; namely, the research highlights of the past year in the specialty of cardiothoracic and vascular anesthesiology. The major themes selected for 2021 are outlined in this introduction, and each highlight is reviewed in detail in the main body of the article. The literature highlights in the specialty for 2021 begin with an update on structural heart disease, with a focus on updates in arrhythmia and aortic valve disorders. The second major theme is an update on coronary artery disease, with discussion of both medical and procedural management. The third major theme is focused on the perioperative management of patients with COVID-19, with the authors highlighting literature discussing the impact of the disease on the right ventricle and thromboembolic events. The fourth and final theme is an update in heart failure, with discussion of diverse aspects of this area. The themes selected for this fourteenth special article are only a few of the diverse advances in the specialty during 2021. These highlights will inform the reader of key updates on a variety of topics, leading to improvement of perioperative outcomes for patients with cardiothoracic and vascular disease.

Venous thromboembolism in patients with COVID-19 infection: risk factors, prevention, and management

Venous thromboembolic complications have emerged as serious sequelae in COVID-19 infections. This article summarizes the most current information regarding pathophysiology, risk factors and hematologic markers, incidence and timing of events, atypical venous thromboembolic complications, prophylaxis recommendations, and therapeutic recommendations. Data will likely to continue to rapidly evolve as more knowledge is gained regarding venous events in COVID-19 patients.

A systematic review and meta-analysis of incidence, prognosis, and laboratory indicators of venous thromboembolism in hospitalized patients with coronavirus disease 2019

OBJECTIVE

We have summarized the incidence, anticoagulation panels, laboratory characteristics, and mortality of venous thromboembolism (VTE) in hospitalized patients with coronavirus disease 2019 (COVID-19).

METHODS

After systematically searching PubMed, Embase, the Cochrane Library, MedRxiv, and BioRxiv, a systematic review and meta-analysis of 18 retrospective, 6 prospective observational, and 2 cross-sectional studies was performed according to the guidelines of the PRISMA (preferred reporting items for systematic reviews and meta-analyses) statement.

RESULTS

Overall, 4382 hospitalized patients with COVID-19 were included. Men accounted for significantly more patients than did women (odds ratio [OR], 1.59; 95% confidence interval [CI], 1.25-2.02; P < .001). The total incidence of VTE among the patients with COVID-19 was 28.3% (95% CI, 21.6%-35.4%), with an incidence of 38.0% (95% CI, 29.1%-47.4%) and 17.2% (95% CI, 11.4%-23.8%) among those with severe and general COVID-19, respectively. The total incidence of deep vein thrombosis (DVT) of the lower extremities was 18.3% (95% CI, 10.8%-27.2%). The incidence of DVT was 22.1% (95% CI, 11.0%-35.5%) and 12.8% (95% CI, 5.0%-23.3%) in those with severe and general COVID-19, respectively. The total incidence of pulmonary embolism was 17.6% (95% CI, 12.3%-23.5%), with a rate of 21.7% (95% CI, 14.8%-29.3%) in severe cases and 12.5% (95% CI, 6.1%-23.5%) in general cases. When COVID-19 severity was unclassified, the mortality for the patients with VTE was not significantly greater (25.2%; 95% CI, 12.2%-40.5%) than that for those without VTE (10.2%; 95% CI, 3.4%-19.5%; OR, 1.88; 95% CI, 0.46-7.64; P = .377). However, among the patients with severe COVID-19, those who had developed VTE had significantly greater mortality compared with those without VTE (OR, 2.02; 95% CI, 1.15-3.53; P = .014). The patients with COVID-19 and VTE had significantly higher D-dimer levels than did similar patients without VTE in multiple studies.

CONCLUSIONS

The occurrence of VTE, DVT, and pulmonary embolism has been substantial among hospitalized patients with COVID-19, especially among those with severe COVID-19. Patients with severe COVID-19 and VTE had significantly greater mortality compared with similar patients without VTE. An increased D-dimer level might be an indicator of the occurrence of VTE in patients with COVID-19.

Usefulness of Easy-to-Use Risk Scoring Systems Rated in the Emergency Department to Predict Major Adverse Outcomes in Hospitalized COVID-19 Patients

Background: Several easy-to-use risk scoring systems have been built to identify patients at risk of developing complications associated with COVID-19. However, information about the ability of each score to early predict major adverse outcomes during hospitalization of severe COVID-19 patients is still scarce. Methods: Eight risk scoring systems were rated upon arrival at the Emergency Department, and the occurrence of thrombosis, need for mechanical ventilation, death, and a composite that included all major adverse outcomes were assessed during the hospital stay. The clinical performance of each risk scoring system was evaluated to predict each major outcome. Finally, the diagnostic characteristics of the risk scoring system that showed the best performance for each major outcome were obtained. Results: One hundred and fifty-seven adult patients (55 ± 12 years, 66% men) were assessed at admission to the Emergency Department and included in the study. A total of 96 patients (61%) had at least one major outcome during hospitalization; 32 had thrombosis (20%), 80 required mechanical ventilation (50%), and 52 eventually died (33%). Of all the scores, Obesity and Diabetes (based on a history of comorbid conditions) showed the best performance for predicting mechanical ventilation (area under the ROC curve (AUC), 0.96; positive likelihood ratio (LR+), 23.7), death (AUC, 0.86; LR+, 4.6), and the composite outcome (AUC, 0.89; LR+, 15.6). Meanwhile, the inflammation-based risk scoring system (including leukocyte count, albumin, and C-reactive protein levels) was the best at predicting thrombosis (AUC, 0.63; LR+, 2.0). Conclusions: Both the Obesity and Diabetes score and the inflammation-based risk scoring system appeared to be efficient enough to be integrated into the evaluation of COVID-19 patients upon arrival at the Emergency Department.

Venous thromboembolism in COVID-19: A systematic review and meta-analysis

Severe coronavirus disease 2019 (COVID-19) is associated with increased risk of venous thromboembolism events (VTE). This study performed a systematic review in PubMed/EMBASE of studies reporting the prevalence of VTE in patients with COVID-19 who were totally screened/assessed for deep vein thrombosis (DVT) and/or for pulmonary embolism (PE). Among 47 candidate studies (n = 6459; 33 in Europe), 17 studies (n = 3973; weighted age 63.0 years, males 60%, intensive care unit (ICU) 16%) reported the prevalence of PE with a pooled estimate of 32% (95% CI: 25, 40%), and 32 studies (n = 2552; weighted age 62.6 years, males 57%, ICU 49%) reported the prevalence of DVT with a pooled estimate of 27% (95% CI: 21, 34%). A total of 36 studies reported the use of at least prophylactic antithrombotic treatment in the majority of their patients. Meta-regression analysis showed that the prevalence of VTE was higher across studies with a higher percentage of ICU patients and higher study population mean D-dimer values, and lower in studies with mixed dosing of anticoagulation in ⩾ 50% of the population compared to studies with standard prophylactic dosing of anticoagulation in < 50% of the population. The pooled odds ratio for death in patients with COVID-19 and VTE versus those without VTE (17 studies, n = 2882) was 2.1 (95% CI: 1.2, 3.6). Hospitalized patients with severe COVID-19 are at high VTE risk despite prophylactic anticoagulation. Further research should investigate the individualized VTE risk of patients with COVID-19 and the optimal preventive antithrombotic therapy. PROSPERO Registration No.: CRD42020185543.

How we approach thrombosis risk in children with COVID-19 infection and MIS-C

Thrombosis within the microvasculature and medium to large vessels is a serious and common complication among critically ill individuals with coronavirus disease 2019 (COVID-19). While children are markedly less likely to develop severe disease than adults, they remain at risk for thrombosis during acute infection and with the post-acute inflammatory illness termed multisystem inflammatory syndrome in children. Significant knowledge deficits in understanding COVID-19-associated coagulopathy and thrombotic risk pose clinical challenges for pediatric providers who must incorporate expert opinion and personal experience to manage individual patients. We discuss clinical scenarios to provide framework for characterizing thrombosis risk and thromboprophylaxis in children with COVID-19.

Point of care ultrasound screening for deep vein thrombosis in critically ill COVID-19 patients, an observational study

BACKGROUND

Deep vein thrombosis (DVT) is common in critically ill patients with Coronavirus disease 2019 (COVID-19) and may cause fatal pulmonary embolism (PE) prior to diagnosis due to subtle clinical symptoms. The aim of this study was to explore the feasibility of bedside screening for DVT in critically ill COVID-19 patients performed by physicians with limited experience of venous ultrasound. We further aimed to compare inflammation, coagulation and organ dysfunction in patients with and without venous thromboembolism (VTE).

METHODS

This observational study included patients with COVID-19 admitted to the intensive care unit (ICU) of a tertiary hospital in Sweden and screened for DVT with proximal compression ultrasound of the lower extremities between April and July 2020. Screening was performed by ICU residents having received a short online education and one hands-on-session. Pathological screening ultrasound was confirmed by formal ultrasound whereas patients with negative screening underwent formal ultrasound on clinical suspicion. Clinical data, laboratory findings and follow-up were extracted from medical records.

RESULTS

Of 90 eligible patients, 56 were screened by seven ICU residents with no (n = 5) or limited (n = 2) previous experience of DVT ultrasound who performed a median of 4 (IQR 2-19) examinations. Four (7.1%) patients had pathological screening ultrasound of which three (5.6%) were confirmed by formal ultrasound. None of the 52 patients with negative screening ultrasound were diagnosed with DVT during follow-up. Six patients were diagnosed with PE of which four prior to negative screening and two following negative and positive screening respectively. Patients with VTE (n = 8) had higher median peak D-dimer (24.0 (IQR 14.2-50.5) vs. 2.8 (IQR 1.7-7.2) mg/L, p = 0.004), mean peak C-reactive protein (363 (SD 80) vs. 285 (SD 108) mg/L, p = 0.033) and median peak plasma creatinine (288 (IQR 131-328) vs. 94 (IQR 78-131) μmol/L, p = 0.009) compared to patients without VTE (n = 48). Five patients (63%) with VTE received continuous renal replacement therapy compared to six patients (13%) without VTE (p = 0.005).

CONCLUSION

ICU residents with no or limited experience could detect DVT with ultrasound in critically ill COVID-19 patients following a short education. VTE was associated with kidney dysfunction and features of hyperinflammation and hypercoagulation.

TRIAL REGISTRATION

ClinicalTrials ID: NCT04316884 . Registered 20 March 2020.

Serial markers of coagulation and inflammation and the occurrence of clinical pulmonary thromboembolism in mechanically ventilated patients with SARS-CoV-2 infection; the prospective Maastricht intensive care COVID cohort

Background

The incidence of pulmonary thromboembolism is high in SARS-CoV-2 patients admitted to the Intensive Care. Elevated biomarkers of coagulation (fibrinogen and D-dimer) and inflammation (c-reactive protein (CRP) and ferritin) are associated with poor outcome in SARS-CoV-2. Whether the time-course of fibrinogen, D-dimer, CRP and ferritin is associated with the occurrence of pulmonary thromboembolism in SARS-CoV-2 patients is unknown. We hypothesise that patients on mechanical ventilation with SARS-CoV-2 infection and clinical pulmonary thromboembolism have lower concentrations of fibrinogen and higher D-dimer, CRP, and ferritin concentrations over time compared to patients without a clinical pulmonary thromboembolism.

Methods

In a prospective study, fibrinogen, D-dimer, CRP and ferritin were measured daily. Clinical suspected pulmonary thromboembolism was either confirmed or excluded based on computed tomography pulmonary angiography (CTPA) or by transthoracic ultrasound (TTU) (i.e., right-sided cardiac thrombus). In addition, patients who received therapy with recombinant tissue plasminogen activator were included when clinical instability in suspected pulmonary thromboembolism did not allow CTPA. Serial data were analysed using a mixed-effects linear regression model, and models were adjusted for known risk factors (age, sex, APACHE-II score, body mass index), biomarkers of coagulation and inflammation, and anticoagulants.

Results

Thirty-one patients were considered to suffer from pulmonary thromboembolism ((positive CTPA (n = 27), TTU positive (n = 1), therapy with recombinant tissue plasminogen activator (n = 3)), and eight patients with negative CTPA were included. After adjustment for known risk factors and anticoagulants, patients with, compared to those without, clinical pulmonary thromboembolism had lower average fibrinogen concentration of − 0.9 g/L (95% CI: − 1.6 – − 0.1) and lower average ferritin concentration of − 1045 μg/L (95% CI: − 1983 – − 106) over time. D-dimer and CRP average concentration did not significantly differ, 561 μg/L (− 6212–7334) and 27 mg/L (− 32–86) respectively. Ferritin lost statistical significance, both in sensitivity analysis and after adjustment for fibrinogen and D-dimer.

Conclusion

Lower average concentrations of fibrinogen over time were associated with the presence of clinical pulmonary thromboembolism in patients at the Intensive Care, whereas D-dimer, CRP and ferritin were not. Lower concentrations over time may indicate the consumption of fibrinogen related to thrombus formation in the pulmonary vessels.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12959-021-00286-7.

Circulating Calprotectin as a Biomarker of COVID-19 Severity

INTRODUCTION

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Although demographic and clinical parameters such as sex, age, comorbidities, genetic background and various biomarkers have been identified as risk factors, there is an unmet need to predict the risk and onset of severe inflammatory disease leading to poor clinical outcomes. In addition, very few mechanistic biomarkers are available to inform targeted treatment of severe (auto)-inflammatory conditions associated with COVID-19. Calprotectin, also known as S100A8/S100A9, MRP8/14 (Myeloid-Related Protein) or L1, is a heterodimer involved in neutrophil-related inflammatory processes. In COVID-19 patients, calprotectin levels were reported to be associated with poor clinical outcomes such as significantly reduced survival time, especially in patients with severe pulmonary disease.

AREAS COVERED

Pubmed was searched using the following keywords: Calprotectin + COVID19, S100A8/A9 + COVID19, S100A8 + COVID-19, S100A9 + COVID-19, MRP8/14 + COVID19; L1 + COVID-19 between May 2020 and 8 March 2021. The results summarized in this review provide supporting evidence and propose future directions that define calprotectin as an important biomarker in COVID-19.

EXPERT OPINION

Calprotectin represents a promising serological biomarker for the risk assessment of COVID-19 patients.

Clinical characteristics and outcomes of venous thromboembolism in patients hospitalized for COVID-19: Systematic review and meta-analysis

Venous thromboembolism is prevalent in hospitalized COVID-19 patients. Through systematic review and meta-analysis, we have investigated the differences in clinical characteristics and outcome of hospitalized COVID-19 patients with (+) and without (-) venous thromboembolism (VTE). 45 studies with a total of 8859 patients were included in the qualitative synthesis. Subsequently, 38 studies with a total of 7847 patients, were quantitatively analyzed. There was no mortality difference between the VTE (-) and VTE (+) hospitalized COVID-19 patients (RR1.32 (0.97, 1.79); 0.07; I2 64%, p ​< ​0.001). Patients with VTE (+) were more likely to get admitted to the intensive care unit (RR1.77 (1.26, 2.50); p ​< ​0.001; I2 63%, p ​= ​0.03) and mechanically ventilated (RR 2.35 (1.22, 4.53); p ​= ​0.01; I2 88%, p ​< ​0.001). Moreover, male gender (RR 1.19 (1.14,1.24), p ​< ​0.001; I2 0%, p ​= ​0.68), increased the risk of VTE. Regarding patients lab values', VTE (+) was significantly associated with higher white blood cell, neutrophil count, D-Dimer, alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and C-reactive protein (CRP), along with prolonged prothrombin time. On the contrary, VTE (+) was associated with lower albumin and neutrophil-lymphocyte ratio (NLR). This findings provide the initial framework for risk stratification of hospitalized COVID-19 patients with VTE.

Risk of Clinically Relevant Venous Thromboembolism in Critically Ill Patients With COVID-19: A Systematic Review and Meta-Analysis

Background: Early during the course of the ongoing COVID-19 pandemic, reports suggested alarmingly high incidences for thromboembolic events in critically ill patients with COVID-19. However, the clinical relevance of these events was not reported in several studies. Additionally, more recent research showed contradictory results and suggested substantially lower rates of venous thromboembolism. Thus, the aim of the present study was to summarize evidence on the incidence of clinically relevant venous thromboembolism (VTE)—defined as VTE excluding isolated subsegmental pulmonary embolism (PE) and distal deep vein thrombosis (DVT)—in adult critically ill patients with COVID-19.

Methods: We performed a systematic review of studies reporting the incidence of clinically relevant PE and/or DVT in critically ill patients with COVID-19. Scientific reports published in the English language between January and October 2020 were included. We conducted a random-effects model meta-analysis to calculate incidence estimates of clinically relevant VTE and bleeding events. We also performed exploratory meta-regression and subgroup analyses of different diagnostic approaches and additional factors that possibly influenced the incidence of these outcomes.

Results: Fifty-four articles (5,400 patients) fulfilled the predefined inclusion criteria, of which 41 had a high risk of bias. The majority of included patients were male, > 60 years, and overweight. Twenty-one studies reported the use of prophylactic doses of heparin. Pooled incidences for clinically relevant PE were estimated at 8% (95% CI, 4–11%), for proximal DVT at 14% (95% CI, 9–20%), and—after exclusion of studies with a high risk of bias—for the composite outcome of VTE at 18% (95% CI, 13–24%). Clinically relevant bleeding occurred at a rate of 6% (95% CI, 2–9%).

Conclusions: We summarized currently available data on the rate of clinically relevant VTE in critically ill patients with COVID-19. Pooled incidence estimates were lower than those reported by previous review articles. In the absence of evidence-based anticoagulation guidelines for critically ill patients with COVID-19, the results of our study provide clinically important information for an individual risk-benefit assessment in this context.

Registration: The study protocol was prospectively registered in PROSPERO on June 22, 2020 (CRD42020193353; https://www.crd.york.ac.uk/prospero).

Risk factors for severe and critically ill COVID-19 patients: A review

The pandemic of coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused an unprecedented global social and economic impact, and high numbers of deaths. Many risk factors have been identified in the progression of COVID-19 into a severe and critical stage, including old age, male gender, underlying comorbidities such as hypertension, diabetes, obesity, chronic lung diseases, heart, liver and kidney diseases, tumors, clinically apparent immunodeficiencies, local immunodeficiencies, such as early type I interferon secretion capacity, and pregnancy. Possible complications include acute kidney injury, coagulation disorders, thoromboembolism. The development of lymphopenia and eosinopenia are laboratory indicators of COVID-19. Laboratory parameters to monitor disease progression include lactate dehydrogenase, procalcitonin, high-sensitivity C-reactive protein, proinflammatory cytokines such as interleukin (IL)-6, IL-1β, Krebs von den Lungen-6 (KL-6), and ferritin. The development of a cytokine storm and extensive chest computed tomography imaging patterns are indicators of a severe disease. In addition, socioeconomic status, diet, lifestyle, geographical differences, ethnicity, exposed viral load, day of initiation of treatment, and quality of health care have been reported to influence individual outcomes. In this review, we highlight the scientific evidence on the risk factors of severity of COVID-19.

Prognostic Value of Antithrombin Levels in COVID-19 Patients and Impact of Fresh Frozen Plasma Treatment: A Retrospective Study

Objective:

The defective interplay between coagulation and inflammation may be the leading cause of intravascular coagulation and organ dysfunction in coronavirus disease-19 (COVID-19) patients. Abnormal coagulation profiles were reported to be associated with poor outcomes. In this study, we assessed the prognostic values of antithrombin (AT) activity levels and the impact of fresh frozen plasma (FFP) treatment on outcome.

Materials and Methods:

Conventional coagulation parameters as well as AT activity levels and outcomes of 104 consecutive critically ill acute respiratory distress syndrome (ARDS) patients with laboratory-confirmed COVID-19 disease were retrospectively analyzed. Patients with AT activity below 75% were treated with FFP. Maximum AT activity levels achieved in those patients were recorded.

Results:

AT activity levels at admission were significantly lower in nonsurvivors than survivors (73% vs. 81%). The cutoff level for admission AT activity was 79% and 58% was the lowest AT for survival. The outcome in those patients who had AT activity levels above 75% after FFP treatment was better than that of the nonresponding group. As well as AT, admission values of D-dimer, C-reactive protein, and procalcitonin were coagulation and inflammatory parameters among the mortality risk factors.

Conclusion:

AT activity could be used as a prognostic marker for survival and organ failure in COVID-19-associated ARDS patients. AT supplementation therapy with FFP in patients with COVID-19-induced hypercoagulopathy may improve thrombosis prophylaxis and thus have an impact on survival.

Hemostasis in Coronavirus Disease 2019-Lesson from Viscoelastic Methods: A Systematic Review

Hemostatic unbalance is often observed in patients with coronavirus disease 2019 (COVID-19), and patients with severe disease are at high risk of developing thromboembolic complications. Viscoelastic methods (VEMs), including thrombelastography (TEG) and thromboelastometry (TEM), provide data on the nature of hemostatic disturbance. In this systematic review, we assessed the performance of TEG and TEM in the assessment of blood coagulation and fibrinolysis in patients with COVID-19. PubMed, Scopus, Web of Science Core Collection, medRxiv, and bioRxiv were systematically searched for clinical studies evaluating TEG and/or TEM variables in COVID-19 individuals. Ten studies, with a total of 389 COVID-19 patients, were included, and VEMs were performed in 292 of these patients. Most patients (90%) presented severe COVID-19 and required mechanical ventilation. TEG and TEM variables showed that these patients displayed hypercoagulability and fibrinolysis shutdown, despite the use of appropriate thromboprophylaxis. However, the mechanism underlying these phenomena and their clinical significance in COVID-19 patients who developed thrombosis are still not clear. Further studies are warranted if VEMs might help to identify those at highest risk of thrombotic events and who therefore may derive the greatest benefit from antithrombotic therapy.

Prediction models for diagnosis and prognosis of covid-19: systematic review and critical appraisal

OBJECTIVE

To review and appraise the validity and usefulness of published and preprint reports of prediction models for diagnosing coronavirus disease 2019 (covid-19) in patients with suspected infection, for prognosis of patients with covid-19, and for detecting people in the general population at increased risk of covid-19 infection or being admitted to hospital with the disease.

DESIGN

Living systematic review and critical appraisal by the COVID-PRECISE (Precise Risk Estimation to optimise covid-19 Care for Infected or Suspected patients in diverse sEttings) group.

DATA SOURCES

PubMed and Embase through Ovid, up to 1 July 2020, supplemented with arXiv, medRxiv, and bioRxiv up to 5 May 2020.

STUDY SELECTION

Studies that developed or validated a multivariable covid-19 related prediction model.

DATA EXTRACTION

At least two authors independently extracted data using the CHARMS (critical appraisal and data extraction for systematic reviews of prediction modelling studies) checklist; risk of bias was assessed using PROBAST (prediction model risk of bias assessment tool).

RESULTS

37 421 titles were screened, and 169 studies describing 232 prediction models were included. The review identified seven models for identifying people at risk in the general population; 118 diagnostic models for detecting covid-19 (75 were based on medical imaging, 10 to diagnose disease severity); and 107 prognostic models for predicting mortality risk, progression to severe disease, intensive care unit admission, ventilation, intubation, or length of hospital stay. The most frequent types of predictors included in the covid-19 prediction models are vital signs, age, comorbidities, and image features. Flu-like symptoms are frequently predictive in diagnostic models, while sex, C reactive protein, and lymphocyte counts are frequent prognostic factors. Reported C index estimates from the strongest form of validation available per model ranged from 0.71 to 0.99 in prediction models for the general population, from 0.65 to more than 0.99 in diagnostic models, and from 0.54 to 0.99 in prognostic models. All models were rated at high or unclear risk of bias, mostly because of non-representative selection of control patients, exclusion of patients who had not experienced the event of interest by the end of the study, high risk of model overfitting, and unclear reporting. Many models did not include a description of the target population (n=27, 12%) or care setting (n=75, 32%), and only 11 (5%) were externally validated by a calibration plot. The Jehi diagnostic model and the 4C mortality score were identified as promising models.

CONCLUSION

Prediction models for covid-19 are quickly entering the academic literature to support medical decision making at a time when they are urgently needed. This review indicates that almost all pubished prediction models are poorly reported, and at high risk of bias such that their reported predictive performance is probably optimistic. However, we have identified two (one diagnostic and one prognostic) promising models that should soon be validated in multiple cohorts, preferably through collaborative efforts and data sharing to also allow an investigation of the stability and heterogeneity in their performance across populations and settings. Details on all reviewed models are publicly available at https://www.covprecise.org/. Methodological guidance as provided in this paper should be followed because unreliable predictions could cause more harm than benefit in guiding clinical decisions. Finally, prediction model authors should adhere to the TRIPOD (transparent reporting of a multivariable prediction model for individual prognosis or diagnosis) reporting guideline.

SYSTEMATIC REVIEW REGISTRATION

Protocol https://osf.io/ehc47/, registration https://osf.io/wy245.

READERS' NOTE

This article is a living systematic review that will be updated to reflect emerging evidence. Updates may occur for up to two years from the date of original publication. This version is update 3 of the original article published on 7 April 2020 (BMJ 2020;369:m1328). Previous updates can be found as data supplements (https://www.bmj.com/content/369/bmj.m1328/related#datasupp). When citing this paper please consider adding the update number and date of access for clarity.