Reporting of D-dimer data in COVID-19: some confusion and potential for misinformation

The performance of quantitative D-dimer assays in Chinese clinical laboratories by analyzing data from National External quality Assessment Scheme

BACKGROUND AND AIMS

To investigate performance of D-dimer assays in China and address analytical quality issues.

MATERIALS AND METHODS

D-dimer assays data were collected from China National External Quality Assessment Scheme (China NEQAS) from 2014 to 2022. We analyzed reagents, assay results, reporting unit and cutoffs in 2022 China NEQAS. Interlaboratory coefficient variations (CVs) and influence of modified/unmodified test systems on CVs were investigated over 9 years.

RESULTS

There were 82 reagent brands in China NEQAS, but 55 reagent instructions did not indicate expression unit (DDU or FEU). Up to 7-fold of the ratio of max-to-min mean results was shown among different assays with same unit on the same sample. A prevalence of FEU (63.4%) over DDU (17.1%) was observed. Although 669 laboratories (37.9%) among 1766 laboratories used reagents without VTE exclusion claim, they also reported cutoffs. The CVs of only two assays were decreasing over years. CVs of modified test systems were higher than those of unmodified systems before improvement.

CONCLUSIONS

Expression unit should be required to label in package inserts by regulatory authority. Laboratory professionals should follow instructions for use and prefer unmodified test systems for clinical safely application. Harmonization of reporting units through collaborative efforts is the promising step.

D-dimer Levels for the exclusion of pulmonary embolism: making sense of international guideline recommendations

Several international guidelines provide recommendations around the use of D-dimer testing for exclusion of pulmonary embolism, including the appropriate D-dimer threshold (or cutoff), but there is no consensus among them. We briefly discuss guideline variation, performance characteristics, and limitations of commercially available D-dimer assays in this setting, referencing the Clinical and Laboratory Standards Institute guidelines that recommend immunoassays with high sensitivity (≥97%) and negative predictive value (≥98%). While age-adjusted D-dimer and pretest-adjusted D-dimer are considered a safe strategy across predefined patient subgroups, clinicians need to recognize the different performance characteristics of D-dimer assays to enable safe clinical decisions for their patients. Importantly, D-dimer values must be correlated not only to clinical findings but also interpreted within the context of the accuracy and precision of the specific testing modality, adhering to manufacturer specifications that are approved by regulatory authorities.

Variable Performance of D-dimer Testing by Hemostasis Laboratories: The Australasian/Asia-Pacific Experience

D-dimers represent the breakdown products of fibrin. Thus, elevated plasma D-dimers will arise following a thrombotic event, such as a deep vein thrombosis or a pulmonary embolism, and therefore, a nonelevated D-dimer is used to effectively exclude such events. D-dimers are also elevated in a range of other conditions, for example, during disseminated intravascular coagulation. D-dimer levels may also be associated with prognostic value. For example, highly raised D-dimer levels can be associated with worsening clinical features in coronavirus disease 2019. Thus, D-dimer testing represents a commonly requested hemostasis test, often performed in 24/7 laboratories. Unfortunately, D-dimer testing is neither standardized nor harmonized across manufacturers or laboratories. Indeed, considering reporting units and the magnitude of units, up to 28 different combinations may be reported by laboratories. We provide updated findings for D-dimer testing in our geographic region, using recent data from the Royal College of Pathologists of Australasia Quality Assurance Programs, an international external quality assessment program, currently with over 450 participants in the D-dimer module. Data show a wide variety of assays in use and variable outcomes in reported numerical values when assessing proficiency samples. D-dimer testing mostly comprised reagents from three main manufacturing suppliers, with a small number of users of reagents from other manufacturers. Reported results showed important differences in numerical values for the same homogeneous tested samples when normalized to a single reporting unit (e.g., mg/L). Nevertheless, despite using different test reagents and reporting, most participants uniformly identified D-dimer values as below or above a "detection" cut-off for samples that were constructed to be below or above most cut-off values. As expected, mixed findings were reported for samples containing levels around expected cut-off values. We hope that our findings, reflecting on the heterogeneity of test reagents and test data, help improve diagnostic testing for D-dimer testing and facilitate harmonization and standardization, in the future.

Machine learning algorithms in sepsis

Sepsis remains a significant global health challenge due to its high mortality and morbidity, compounded by the difficulty of early detection given its variable clinical manifestations. The integration of machine learning (ML) into laboratory medicine for timely sepsis identification and outcome forecasting is an emerging field of interest. This comprehensive review assesses the current body of research on ML applications for sepsis within the realm of laboratory diagnostics, detailing both their strengths and shortcomings. An extensive literature search was performed by two independent investigators across PubMed and Scopus databases, employing the keywords "Sepsis," "Machine Learning," and "Laboratory" without publication date limitations, culminating in January 2023. Each selected study was meticulously evaluated for various aspects, including its design, intent (diagnostic or prognostic), clinical environment, demographics, sepsis criteria, data gathering period, and the scope and nature of features, in addition to the ML methodologies and their validation procedures. Out of 135 articles reviewed, 39 fulfilled the criteria for inclusion. Among these, the majority (30 studies) were focused on devising ML algorithms for diagnosis, fewer (8 studies) on prognosis, and one study addressed both aspects. The dissemination of these studies across an array of journals reflects the interdisciplinary engagement in the development of ML algorithms for sepsis. This analysis highlights the promising role of ML in the early diagnosis of sepsis while drawing attention to the need for uniformity in validating models and defining features, crucial steps for ensuring the reliability and practicality of ML in clinical setting.

D-dimer diagnostics: can I use any D-dimer assay? Bridging the knowledge-to-action gap

A State of the Art lecture titled "D-dimer Diagnostics: Can I use any D-dimer assay? Bridging the Knowledge-to-Action gap" was presented at the International Society on Thrombosis and Haemostasis Congress in 2023, included in the session on the clinical impact of variability in commonly used coagulation assays. Here, we review the role of D-dimer, primarily in the outpatient diagnosis of patients with venous thromboembolism (VTE) when combined with clinical decision rules. We focus on the recent large management trials that have studied adjustments of VTE exclusion thresholds for D-dimer based on either prior clinical probability of VTE or patient age, and the resultant benefit of reduced imaging for VTE and improved diagnostic efficiency. In this context, we report on the significant variability between D-dimer results and the multiple D-dimer assays in use worldwide using data from international external quality assurance programs. This variability is particularly high at typical VTE exclusion thresholds. We discuss the potential clinical impact of D-dimer assay substitution on accuracy of diagnosis and risk stratification of patients with VTE. Finally, we summarize relevant new data on this topic presented during the 2023 International Society on Thrombosis and Haemostasis Congress and outline future priorities urgently needed to harmonize D-dimer results and reporting that will require international collaboration among multiple stakeholders with an overall goal to close this knowledge-to-action gap.

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

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

C-reactive protein and clinical outcome in COVID-19 patients: the importance of harmonized measurements

C-reactive protein (CRP) is a cytokine-mediated acute phase reactant with a recognized role in inflammatory conditions and infectious disease. In coronavirus disease 2019 (COVID-19), elevated CRP concentrations in serum were frequently detected and significantly associated with poor outcome in terms of disease severity, need for intensive care, and in-hospital death. For these reasons, the marker was proposed as a powerful test for prognostic classification of COVID-19 patients. In most of available publications, there was however confounding information about how interpretative criteria for CRP in COVID-19 should be derived, including quality of employed assays and optimal cut-off definition. Assuring result harmonization and controlling measurement uncertainty in terms of performance specifications are fundamental to allow worldwide application of clinical information according to specific CRP thresholds and to avoid risk of patient misclassification.

Zirconium dioxide as electrochemiluminescence emitter for D-dimer determination based on dual-quenching sensing strategy

The ECL emission of simple and stable zirconium dioxide nanomaterials has always been a blank slate in the ECL sensors field. In this work, zirconium dioxide (ZrO₂)-titanium dioxide (TiO₂)-gold nanoparticle (AuNPs) composite (ZT-Au), a novel self-enhanced ECL emitter, was introduced the system of dual-quenching ECL immunosensor. The anodic luminescence of ZrO₂ in the system of tripropylamine (TPrA) as a co-reagent was first reported and explored. Meanwhile, TiO₂ was designed into the ECL scheme as a co-reaction accelerator to form the ZrO₂/TPrA/TiO₂ ternary system, which can efficiently amplify the ECL signal of the emitter. In addition, cuprous oxide-triaminophenol (Cu₂O-APF) as the quencher was devoted to the dual-quenching sensing strategy. The dual-quenching mechanism that effectively boosted the immunosensor sensitivity was adequately investigated and conjectured in this paper. The sensing model based on the luminophor ZT-Au and the quencher Cu₂O-APF was utilized for the detection of D-dimer, a reliable marker for the diagnosis and evaluation of thrombotic diseases. The short peptide ligands NARKFYKGC (NFC) with efficient biological affinity were used to site-directionally capture antibodies for adequately protecting the activity of antigen binding sites during the construction of the immunosensor. The implemented immunosensor was equipped with a broad linear range of 0.01-500 ng/mL and a low detection limit of 3.6 pg/mL. The original methodology opens up the field of vision for the detection of additional biomarkers.

Hemostasis and Thrombosis: An Overview Focusing on Associated Laboratory Testing to Diagnose and Help Manage Related Disorders

Hemostasis is a complex but balanced process that permit normal blood flow, without adverse events. Disruption of the balance may lead to bleeding or thrombotic events, and clinical interventions may be required. Hemostasis laboratories typically offer an array of tests, including routine coagulation and specialized hemostasis assays used to guide clinicians for diagnosing and managing patients. Routine assays may be used to screen patients for hemostasis-related disturbances but may also be used for drug monitoring, measuring efficacy of replacement or adjunctive therapy, and other indications, which may then be used to guide further patient management. Similarly, "specialized" assays are used for diagnostic purposes or may be used to monitor or measure efficacy of a given therapy. This chapter provides an overview of hemostasis and thrombosis, with a focus on laboratory testing that may be used to diagnose and help manage patients suspected of hemostasis- and thrombosis-related disorders.

Post-analytical Issues in Hemostasis and Thrombosis Testing: An Update

There are typically three phases identified as contributing to the total testing process. The preanalytical phase starts with the clinician and the patient, when laboratory testing is being considered. This phase also includes decisions about which tests to order (or not), patient identification, blood collection, blood transport, sample processing, and storage to name a few. There are many potential failures that may occur in this preanalytical phase, and these are the topic of another chapter in this book. The second phase, the analytical phase, represents the performance of the test, which is essentially covered in various protocols in this book and the previous edition. The third is the post-analytical phase, which is what occurs after sample testing, and is the topic of the current chapter. Post-analytical issues are generally related to reporting and interpretation of test results. This chapter provides a brief description of these events, as well as guidance for preventing or minimizing post-analytical issues. In particular, there are several strategies for improved post-analytical reporting of hemostasis assays, with this providing the final opportunity to prevent serious clinical errors in patient diagnosis or management.

The harmonization issue in laboratory medicine: the commitment of CCLM

The analytical quality of the clinical laboratory results has shown a significant improvement over the past decades, thanks to the joint efforts of different stakeholders, while the comparability among the results produced by different laboratories and methods still presents some critical issues. During these years, Clinical Chemistry and Laboratory Medicine (CCLM) published several papers on the harmonization issue over all steps in the Total Testing Process, training an important number of laboratory professionals in evaluating and monitoring all the criticisms inherent to the pre-analytical, as well as analytical and post analytical phases: from the consensus statement on the most informative testing in emergency setting, to the prevention and detection of hemolysis or to patients identification and tube labeling procedures, as far as to different approaches to harmonize hormones measurements or to describe new reference methods or to harmonize the laboratory report. During these years the commitment of the journal, devoted to the harmonization processes has allowed to improve the awareness on the topic and to provide specific instruments to monitor the rate of errors and to improve patients safety.

Recent advances in laboratory hematology reflected by a decade of CCLM publications

On the occasion of the 60th anniversary of Clinical Chemistry and Laboratory Medicine (CCLM) we present a review of recent developments in the discipline of laboratory hematology as these are reflected by papers published in CCLM in the period 2012–2022. Since data on CCLM publications from 1963 to 2012 are also available, we were able to make a comparison between the two periods. This interestingly revealed that the share of laboratory hematology papers has steadily increased and reached now 16% of all papers published in CCLM. It also became evident that blood coagulation and fibrinolysis, erythrocytes, platelets and instrument and method evaluation constituted the ‘hottest’ topics with regard to number of publications. Some traditional, characteristic CCLM categories like reference intervals, standardization and harmonization, were more stable and probably will remain so in the future. With the advent of important newer topics, like new coagulation assays and drugs and cell population data generated by hematology analyzers, laboratory hematology is anticipated to remain a significant discipline in CCLM publications.

Neutrophil count multiplied by D-dimer combined with pneumonia may better predict short-term outcomes in patients with acute ischemic stroke

Objective

To investigate the predictive value of neutrophil, D-dimer and diseases associated with stroke for short-term outcomes of acute ischemic stroke (AIS).

Methods

By collecting the subitems of laboratory data especially routine blood and coagulation test in AIS patients, and recording their clinical status, the correlation, regression and predictive value of each subitem with the short-term outcomes of AIS were analyzed. The predict model was constructed.

Results

The neutrophil count multiplied by D-dimer (NDM) had the best predictive value among the subitems, and the area under the receiver operating characteristic (ROC) curve reached 0.804. When clinical information was not considered, the Youden index of NDM was calculated to be 0.48, corresponding to an NDM value of 7.78, a diagnostic sensitivity of 0.79, specificity of 0.69, negative predictive value of 96%. NDM were divided into 5 quintiles, the five grade of NDM (quintile) were < = 1.82, 1.83–2.41, 2.42–3.27, 3.28–4.49, 4.95+, respectively. The multivariate regression analysis was conducted between NDM (quintile), Babinski+, pneumonia, cardiac disease and poor outcomes of AIS. Compared with the first grade of NDM (quintile), the second grade of NDM (quintile) was not significant, but the third grade of NDM (quintile) showed 7.061 times, the fourth grade of NDM (quintile) showed 11.776 times, the fifth grade of NDM (quintile) showed 23.394 times in short-term poor outcomes occurrence. Babinski sign + showed 1.512 times, pneumonia showed 2.995 times, cardiac disease showed 1.936 times in short-term poor outcomes occurrence compared with those negative patients.

Conclusions

NDM combined with pneumonia may better predict short-term outcomes in patients with AIS. Early prevention, regular examination and timely intervention should be emphasized for patients, which may reduce the risk of short-term poor outcomes.

Predictors of venous thromboembolism in COVID-19 patients: results of the COVID-19 Brazilian Registry

Previous studies that assessed risk factors for venous thromboembolism (VTE) in COVID-19 patients have shown inconsistent results. Our aim was to investigate VTE predictors by both logistic regression (LR) and machine learning (ML) approaches, due to their potential complementarity. This cohort study of a large Brazilian COVID-19 Registry included 4120 COVID-19 adult patients from 16 hospitals. Symptomatic VTE was confirmed by objective imaging. LR analysis, tree-based boosting, and bagging were used to investigate the association of variables upon hospital presentation with VTE. Among 4,120 patients (55.5% men, 39.3% critical patients), VTE was confirmed in 6.7%. In multivariate LR analysis, obesity (OR 1.50, 95% CI 1.11-2.02); being an ex-smoker (OR 1.44, 95% CI 1.03-2.01); surgery ≤ 90 days (OR 2.20, 95% CI 1.14-4.23); axillary temperature (OR 1.41, 95% CI 1.22-1.63); D-dimer ≥ 4 times above the upper limit of reference value (OR 2.16, 95% CI 1.26-3.67), lactate (OR 1.10, 95% CI 1.02-1.19), C-reactive protein levels (CRP, OR 1.09, 95% CI 1.01-1.18); and neutrophil count (OR 1.04, 95% CI 1.005-1.075) were independent predictors of VTE. Atrial fibrillation, peripheral oxygen saturation/inspired oxygen fraction (SF) ratio and prophylactic use of anticoagulants were protective. Temperature at admission, SF ratio, neutrophil count, D-dimer, CRP and lactate levels were also identified as predictors by ML methods. By using ML and LR analyses, we showed that D-dimer, axillary temperature, neutrophil count, CRP and lactate levels are risk factors for VTE in COVID-19 patients.

D-dimer: old dogmas, new (COVID-19) tricks

D-dimer is a fibrin degradation product encompassing multiple cross-linked D domains and/or E domains present in the original fibrinogen molecule, whose generation is only theoretically possible when hemostasis and fibrinolysis pathways are concomitantly activated. D-dimer measurement has now become a pillar in the diagnosis/exclusion and prognostication of venous thromboembolism (VTE) and disseminated intravascular coagulation (DIC), when incorporated into validated clinical algorithms and especially using age-adjusted diagnostic thresholds. Although emerging evidence is also supporting its use for predicting the duration of anticoagulant therapy in certain categories of patients, the spectrum of clinical applications is constantly expanding beyond traditional thrombotic pathologies to the diagnosis of acute aortic dissection, acute intestinal ischemia and cerebral venous thrombosis among others, embracing also clinical management of coronavirus disease 2019 (COVID-19). Recent findings attest that D-dimer elevations are commonplace in patients with severe acute respiratory syndrome (SARS-CoV-2) infection (especially in those with thrombosis), its value predicts the clinical severity (up to death) of COVID-19 and remains more frequently increased in COVID-19 patients with post-discharge clinical sequelae. Further, D-dimer-based anticoagulant escalation may be associated with a lower risk of death in patients with severe SARS-CoV-2 infection and, finally, D-dimer elevation post-COVID-19 vaccination mirrors an increased risk of developing vaccine-induced thrombocytopenia and thrombosis (VITT).

D-dimers-"Normal" Levels versus Elevated Levels Due to a Range of Conditions, Including "D-dimeritis," Inflammation, Thromboembolism, Disseminated Intravascular Coagulation, and COVID-19

D-dimers reflect a breakdown product of fibrin. The current narrative review outlines how D-dimers can arise in normal individuals, as well as in patients suffering from a wide range of disease states. D-dimers in normal individuals without evident thrombosis can arise from background fibrinolytic activity in various tissues, including kidney, mammary and salivary glands, which ensures smooth flow of arising fluids where any blood contamination could be immediately lysed. In addition, healthy individuals can also regularly sustain minor injuries, often unbeknown to them, and wound healing follows clot formation in these situations. D-dimers can also arise in anxiety and following exercise, and are also markers of inflammation. Lung inflammation (triggered by microbes or foreign particles) is perhaps also particularly relevant, since the hemostasis system and fibrinolysis help to trap and remove such debris. Lung inflammation in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may contribute to D-dimer levels additive to thrombosis in patients with COVID-19 (coronavirus disease 2019). Indeed, severe COVID-19 can lead to multiple activation events, including inflammation, primary and secondary hemostasis, and fibrinolysis, all of which may contribute to cumulative D-dimer development. Finally, D-dimer testing has also found a role in the diagnosis and triaging of the so-called (COVID-19) vaccine-induced thrombotic thrombocytopenia.

A Prospective Study Evaluating Cumulative Incidence and a Specific Prediction Rule in Pulmonary Embolism in COVID-19

Rationale

Abnormal values of hypercoagulability biomarkers, such as D-dimer, have been described in Coronavirus Disease 2019 (COVID-19), which has also been associated with disease severity and in-hospital mortality. COVID-19 patients with pneumonia are at greater risk of pulmonary embolism (PE). However, the real incidence of PE is not yet clear, since studies have been limited in size, mostly retrospective, and PE diagnostic procedures were only performed when PE was clinically suspected.

Objectives

(1) To determine the incidence, clinical, radiological, and biological characteristics, and clinical outcomes of PE among patients hospitalized for COVID-19 pneumonia with D-dimer > 1,000 ng/mL. (2) To develop a prognostic model to predict PE in these patients.

Methods

Single-center prospective cohort study. Consecutive confirmed cases of COVID-19 pneumonia with D-dimer > 1,000 ng/mL underwent computed tomography pulmonary angiography (CTPA). Demographic and laboratory data, comorbidities, CTPA scores, treatments administered, and clinical outcomes were analyzed and compared between patients with and without PE. A risk score was constructed from all these variables.

Results

Between 6 April 2020 and 2 February 2021, 179 consecutive patients were included. The overall incidence of PE was 39.7% (71 patients) (CI 95%, 32–47%). In patients with PE, emboli were located mainly in segmental/subsegmental arteries (67%). Patients with PE did not differ from the non-PE group in sex, age, or risk factors for thromboembolic disease. Higher urea, D-Dimer, D-dimer-to-ferritin and D-dimer-to-lactate dehydrogenase (LDH) ratios, platelet distribution width (PDW), and neutrophil-to-lymphocyte ratio (NLR) values were found in patients with PE when compared to patients with non-PE. Besides, lymphocyte counts turned out to be lower in patients with PE. A score for PE prediction was constructed with excellent overall performance [area under the ROC curve-receiver operating characteristic (AUC-ROC) 0.81 (95% CI: 0.73–0.89)]. The PATCOM score stands for Pulmonary Artery Thrombosis in COVID-19 Mallorca and includes platelet count, PDW, urea concentration, and D-dimer-to-ferritin ratio.

Conclusion

COVID-19 patients with pneumonia and D-dimer values > 1,000 ng/mL were presented with a very high incidence of PE, regardless of clinical suspicion. Significant differences in urea, D-dimer, PDW, NLR, and lymphocyte count were found between patients with PE and non-PE. The PATCOM score is presented in this study as a promising PE prediction rule, although validation in further studies is required.

Pathophysiology of COVID-19: Critical Role of Hemostasis

The COVID-19 pandemic, caused by SARS-CoV-2, had its first cases identified in late 2019 and was considered a clinical pandemic in March 2020. In March 2022, more than 500 million people were infected and 6,2 million died as a result of this disease, increasingly associated with changes in human hemostasis, such as hypercoagulation. Numerous factors contribute to the hypercoagulable state, and endothelial dysfunction is the main one, since the activation of these cells can strongly activate platelets and the coagulation system. In addition, there is a dysregulation of the renin-angiotensin system due to the SARS-CoV-2 takeover of the angiotensin converting enzyme 2, resulting in a strong immune response that could further damage the endothelium. Thrombus formation in the pulmonary microvasculature structure in patients with COVID-19 is an important factor to determine the severity of the clinical picture and the outcome of this disease. This review describes the hemostatic changes that occur in SARS-CoV-2 infection, to further improve our understanding of pathogenic mechanisms and the interaction between endothelium dysfunction, kallikrein-kinins, renin angiotensin, and the Coagulation/fibrinolysis systems as underlying COVID-19 effectors. This knowledge is crucial for the development of new effective therapeutic approaches, attenuating the severity of SARS-CoV-2's infection and to reduce the deaths.

How is test laboratory data used and characterised by machine learning models? A systematic review of diagnostic and prognostic models developed for COVID-19 patients using only laboratory data

The current gold standard for COVID-19 diagnosis, the rRT-PCR test, is hampered by long turnaround times, probable reagent shortages, high false-negative rates and high prices. As a result, machine learning (ML) methods have recently piqued interest, particularly when applied to digital imagery (X-rays and CT scans). In this review, the literature on ML-based diagnostic and prognostic studies grounded on hematochemical parameters has been considered. By doing so, a gap in the current literature was addressed concerning the application of machine learning to laboratory medicine. Sixty-eight articles have been included that were extracted from the Scopus and PubMed indexes. These studies were marked by a great deal of heterogeneity in terms of the examined laboratory test and clinical parameters, sample size, reference populations, ML algorithms, and validation approaches. The majority of research was found to be hampered by reporting and replicability issues: only four of the surveyed studies provided complete information on analytic procedures (units of measure, analyzing equipment), while 29 provided no information at all. Only 16 studies included independent external validation. In light of these findings, we discuss the importance of closer collaboration between data scientists and medical laboratory professionals in order to correctly characterise the relevant population, select the most appropriate statistical and analytical methods, ensure reproducibility, enable the proper interpretation of the results, and gain actual utility by using machine learning methods in clinical practice.

Pressure Injury Development, Mitigation, and Outcomes of Patients Proned for Acute Respiratory Distress Syndrome

OBJECTIVE

To describe trends and risk factors for pressure injuries (PIs) in adult critical care patients proned to alleviate acute respiratory distress syndrome secondary to COVID-19 and examine the effectiveness of products and strategies used to mitigate PIs.

METHODS

The authors conducted a retrospective chart review between April 9 and June 8, 2020. Demographic data were analyzed using descriptive statistics. Differences between groups with and without PIs were analyzed.

RESULTS

Among 147 patients, significant PI risk factors included male sex (P = .019), high body mass index (>40 kg/m2; P = .020), low Braden Scale score (<12; P = .018), and low-dose vasopressor therapy (P = .020). Taping endotracheal tubes (ETTs) caused significantly fewer facial PIs than commercial ETT holders (P < .0001). Maximum prone duration/session was a significant risk factor for anterior PIs (P = .016), which dropped 71% with newer pressure redistribution products. d-Dimer greater than 3,200 μg/mL (P = .042) was a significant risk factor for sacrococcygeal PIs while supine. Mortality was 30%; significant risk factors included age older than 60 years (P = .005), Sequential Organ Failure Assessment score greater than 11 (P = .003), and comorbid congestive heart failure (P = .016).

CONCLUSIONS

Taping the ETT, limiting the maximum duration of prone positioning to less than 32 hours, and frequent repositioning while supine may reduce the number of modifiable risk factors for PIs. Standardized methods for testing products for PI prevention will inform individualized patient care.

Predictive factors of six-week mortality in critically ill patients with SARS-CoV-2: A multicenter prospective study

OBJECTIVE

The objective of the study is to identify the risk factors associated with mortality at six weeks, especially by analyzing the role of antivirals and munomodulators.

DESIGN

Prospective descriptive multicenter cohort study.

SETTING

26 Intensive care units (ICU) from Andalusian region in Spain.

PATIENTS OR PARTICIPANTS

Consecutive critically ill patients with confirmed SARS-CoV-2 infection were included from March 8 to May 30.

INTERVENTIONS

None.

VARIABLES

Variables analyzed were demographic, severity scores and clinical condition. Support therapy, drug and mortality were analyzed. An univariate followed by multivariate Cox regression with propensity score analysis was applied.

RESULTS

495 patients were enrolled, but 73 of them were excluded for incomplete data. Thus, 422 patients were included in the final analysis. Median age was 63 years and 305 (72.3%) were men. ICU mortality: 144/422 34%; 14 days mortality: 81/422 (19.2%); 28 days mortality: 121/422 (28.7%); 6-week mortality 152/422 36.5%. By multivariable Cox proportional analysis, factors independently associated with 42-day mortality were age, APACHE II score, SOFA score at ICU admission >6, Lactate dehydrogenase at ICU admission >470U/L, Use of vasopressors, extrarenal depuration, %lymphocytes 72h post-ICU admission <6.5%, and thrombocytopenia whereas the use of lopinavir/ritonavir was a protective factor.

CONCLUSION

Age, APACHE II, SOFA>value of 6 points, along with vasopressor requirements or renal replacement therapy have been identified as predictor factors of mortality at six weeks. Administration of corticosteroids showed no benefits in mortality, as did treatment with tocilizumab. Lopinavir/ritonavir administration is identified as a protective factor.

Meta-Analysis and Systematic Review of Coagulation Disbalances in COVID-19: 41 Studies and 17,601 Patients

Introduction

Coagulation parameters are important determinants for COVID-19 infection. We conducted meta-analysis to assess the association between early hemostatic parameters and infection severity.

Methods

Electronic search was made for papers that addressed clinical characteristics of COVID-19 patients and disease severity. Results were filtered using exclusion and inclusion criteria and then pooled into a meta-analysis to estimate the standardized mean difference (SMD) with 95% confidence interval (CI) for D-dimers, fibrinogen, prothrombin time, platelet count (PLT), activated partial thromboplastin time. To explore the heterogeneity and robustness of our fundings, sensitivity and subgroup analyses were conducted. Publication bias was assessed with contour-enhanced funnel plots and Egger's test by linear regression. Coagulation parameters data from retrospective cohort study of 451 patients with COVID-19 at National Research Center for Cardiac Surgery were included in meta-analysis of published studies.

Results

Overall, 41 original studies (17,601 patients) on SARS-CoV-2 were included. For the two groups of patients, stratified by severity, we identified that D-dimers, fibrinogen, activated partial thromboplastin time, and prothrombin time were significantly higher in the severe group [SMD 0.6985 with 95%CI (0.5155; 0.8815); SMD 0.661 with 95%CI (0.3387; 0.9833); SMD 0.2683 with 95%CI (0.1357; 0.4009); SMD 0.284 with 95%CI (0.1472; 0.4208)]. In contrast, PLT was significantly lower in patients with more severe cases of COVID-19 [SMD -0.1684 with 95%CI (-0.2826; -0.0542)]. Neither the analysis by the leave-one-out method nor the influence diagnostic have identified studies that solely cause significant change in the effect size estimates. Subgroup analysis showed no significant difference between articles originated from different countries but revealed that severity assessment criteria might have influence over estimated effect sizes for platelets and D-dimers. Contour-enhanced funnel plots and the Egger's test for D-dimers and fibrinogen revealed significant asymmetry that might be a sign of publication bias.

Conclusions

The hemostatic laboratory parameters, with exception of platelets, are significantly elevated in patients with severe COVID-19. The two variables with strongest association to disease severity were D-dimers and fibrinogen levels. Future research should aim outside conventional coagulation tests and include analysis of clotting formation and platelet/platelet progenitors characteristics.

Insight into prognostics, diagnostics, and management strategies for SARS CoV-2

The foremost challenge in countering infectious diseases is the shortage of effective therapeutics. The emergence of coronavirus disease (COVID-19) outbreak has posed a great menace to the public health system globally, prompting unprecedented endeavors to contain the virus. Many countries have organized research programs for therapeutics and management development. However, the longstanding process has forced authorities to implement widespread infrastructures for detailed prognostic and diagnostics study of severe acute respiratory syndrome (SARS CoV-2). This review discussed nearly all the globally developed diagnostic methodologies reported for SARS CoV-2 detection. We have highlighted in detail the approaches for evaluating COVID-19 biomarkers along with the most employed nucleic acid- and protein-based detection methodologies and the causes of their severe downfall and rejection. As the variable variants of SARS CoV-2 came into the picture, we captured the breadth of newly integrated digital sensing prototypes comprised of plasmonic and field-effect transistor-based sensors along with commercially available food and drug administration (FDA) approved detection kits. However, more efforts are required to exploit the available resources to manufacture cheap and robust diagnostic methodologies. Likewise, the visualization and characterization tools along with the current challenges associated with waste-water surveillance, food security, contact tracing, and their role during this intense period of the pandemic have also been discussed. We expect that the integrated data will be supportive and aid in the evaluation of sensing technologies not only in current but also future pandemics.

A central role for amyloid fibrin microclots in long COVID/PASC: origins and therapeutic implications

Post-acute sequelae of COVID (PASC), usually referred to as 'Long COVID' (a phenotype of COVID-19), is a relatively frequent consequence of SARS-CoV-2 infection, in which symptoms such as breathlessness, fatigue, 'brain fog', tissue damage, inflammation, and coagulopathies (dysfunctions of the blood coagulation system) persist long after the initial infection. It bears similarities to other post-viral syndromes, and to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Many regulatory health bodies still do not recognize this syndrome as a separate disease entity, and refer to it under the broad terminology of 'COVID', although its demographics are quite different from those of acute COVID-19. A few years ago, we discovered that fibrinogen in blood can clot into an anomalous 'amyloid' form of fibrin that (like other β-rich amyloids and prions) is relatively resistant to proteolysis (fibrinolysis). The result, as is strongly manifested in platelet-poor plasma (PPP) of individuals with Long COVID, is extensive fibrin amyloid microclots that can persist, can entrap other proteins, and that may lead to the production of various autoantibodies. These microclots are more-or-less easily measured in PPP with the stain thioflavin T and a simple fluorescence microscope. Although the symptoms of Long COVID are multifarious, we here argue that the ability of these fibrin amyloid microclots (fibrinaloids) to block up capillaries, and thus to limit the passage of red blood cells and hence O2 exchange, can actually underpin the majority of these symptoms. Consistent with this, in a preliminary report, it has been shown that suitable and closely monitored 'triple' anticoagulant therapy that leads to the removal of the microclots also removes the other symptoms. Fibrin amyloid microclots represent a novel and potentially important target for both the understanding and treatment of Long COVID and related disorders.

Harmonized D-dimer levels upon admission for prognosis of COVID-19 severity: Results from a Spanish multicenter registry (BIOCOVID-Spain study)

Coagulopathy is a key feature of COVID-19 and D-dimer has been reported as a predictor of severity. However, because D-dimer test results vary considerably among assays, resolving harmonization issues is fundamental to translate findings into clinical practice. In this retrospective multicenter study (BIOCOVID study), we aimed to analyze the value of harmonized D-dimer levels upon admission for the prediction of in-hospital mortality in COVID-19 patients. All-cause in-hospital mortality was defined as endpoint. For harmonization of D-dimer levels, we designed a model based on the transformation of method-specific regression lines to a reference regression line. The ability of D-dimer for prediction of death was explored by receiver operating characteristic curves analysis and the association with the endpoint by Cox regression analysis. Study population included 2663 patients. In-hospital mortality rate was 14.3%. Harmonized D-dimer upon admission yielded an area under the curve of 0.66, with an optimal cut-off value of 0.945 mg/L FEU. Patients with harmonized D-dimer ≥ 0.945 mg/L FEU had a higher mortality rate (22.4% vs. 9.2%; p < 0.001). D-dimer was an independent predictor of in-hospital mortality, with an adjusted hazard ratio of 1.709. This is the first study in which a harmonization approach was performed to assure comparability of D-dimer levels measured by different assays. Elevated D-dimer levels upon admission were associated with a greater risk of in-hospital mortality among COVID-19 patients, but had limited performance as prognostic test.

TEG®, Microclot and Platelet Mapping for Guiding Early Management of Severe COVID-19 Coagulopathy

An important component of severe COVID-19 disease is virus-induced endothelilitis. This leads to disruption of normal endothelial function, initiating a state of failing normal clotting physiology. Massively increased levels of von Willebrand Factor (VWF) lead to overwhelming platelet activation, as well as activation of the enzymatic (intrinsic) clotting pathway. In addition, there is an impaired fibrinolysis, caused by, amongst others, increased levels of alpha-(2) antiplasmin. The end result is hypercoagulation (proven by thromboelastography^® (TEG^®)) and reduced fibrinolysis, inevitably leading to a difficult-to-overcome hypercoagulated physiological state. Platelets in circulation also plays a significant role in clot formation, but they themselves may also drive hypercoagulation when they are overactivated due to the interactions of their receptors with the endothelium, immune cells or circulating inflammatory molecules. From the literature it is clear that the role of platelets in severely ill COVID-19 patients has been markedly underestimated or even ignored. We here highlight the value of early management of severe COVID-19 coagulopathy as guided by TEG^®, microclot and platelet mapping. We also argue that the failure of clinical trials, where the efficacy of prophylactic versus therapeutic clexane (low molecular weight heparin (LMWH)) were not always successful, which may be because the significant role of platelet activation was not taken into account during the planning of the trial. We conclude that, because of the overwhelming alteration of clotting, the outcome of any trial evaluating an any single anticoagulant, including thrombolytic, would be negative. Here we suggest the use of the degree of platelet dysfunction and presence of microclots in circulation, together with TEG^®, might be used as a guideline for disease severity. A multi-pronged approach, guided by TEG^® and platelet mapping, would be required to maintain normal clotting physiology in severe COVID-19 disease.

CHA2DS2-VASc score in patients with COVID-19 pneumonia and its relationship with biomarkers of thrombosis, inflammation and myocardial injury

CHA2DS2-VASc score associates with worse prognosis in coronavirus-disease-19 (COVID-19). This study investigated laboratory correlates of increasing CHA2DS2-VASc in patients with COVID-19. Patients with COVID-19 were stratified by CHA2DS2-VASc (Group 1: CHA2DS2-VASc 0-1; Group 2: CHA2DS2-VASc 2-3; Group 3: CHA2DS2-VASc ≥4). We found stepwise increase of D-dimer, hs-Troponin and in-hospital mortality across groups (all P < 0.01). D-dimer and hs-Troponin remained independently associated with CHA2DS2-VASc (B = 0.145, P = 0.03; B = 0.320, P < 0.001, respectively). We found significant correlations between D-dimer and C-reactive protein (CRP) in Group 1 and 2, not in Group3 (r2 = 0.103, P = 0.005; r2 = 0.226, P = 0.001; r2 = 0.021, P = 0.253 respectively), and between D-dimer and hs-Troponin in group 2 and 3, not in Group 1 (r2 = 0.122, P = 0.003; r2 = 0.120, P = 0.007; r2 = 0.006, P = 0.514 respectively). In our cohort, CHA2DS2-VASc was independently associated with D-dimer and hs-Troponin increase. Variable relationships of D-dimer with hs-Troponin and CRP within different CHA2DS2-VASc strata suggest multiple mechanisms to be responsible for D-dimer increase in COVID-19.

Prognostic value of D-dimer/fibrinogen ratio on in-hospital outcomes of patients with heart failure and COVID-19

Aim: In the present study, the relationship between D-dimer/fibrinogen ratio (DFR) and in-hospital outcomes was evaluated in patients with COVID-19 and a diagnosis of heart failure (HF). Materials & methods: In-hospital outcomes were compared in patients with high and low DFR values. Results: With regard to in-hospital outcomes, patients in the third tertile of DFR had a higher rate of mechanical ventilation, cardiogenic shock and death (p < 0.001). The length of ICU stay was longer in the third tertile group (p < 0.001). When evaluated together with infection markers, DFR was found to be an independent predictor of outcomes. Conclusion: DFR can be used as a prognostic marker in patients with COVID-19 with a diagnosis of HF, and perhaps more valuable than other infection markers.

Liver disorders in COVID-19, nutritional approaches and the use of phytochemicals

Coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), has affected millions of people globally. It was declared a pandemic by the World Health Organization in March 2020. The hyperinflammatory response to the entry of SARS-CoV-2 into the host through angiotensin-converting enzyme 2 is the result of a "cytokine storm" and the high oxidative stress responsible for the associated symptomatology. Not only respiratory symptoms are reported, but gastrointestinal symptoms (diarrhea, vomiting, and nausea) and liver abnormalities (high levels of aspartate aminotransferase, alanine aminotransferase transaminases, and bilirubin) are observed in at least 30% of patients. Reduced food intake and a delay in medical services may lead to malnutrition, which increases mortality and poor outcomes. This review provides some strategies to identify malnutrition and establishes nutritional approaches for the management of COVID-19 and liver injury, taking energy and nutrient requirements and their impact on the immune response into account. The roles of certain phytochemicals in the prevention of the disease or as promising target drugs in the treatment of this disease are also considered.

D-dimer as a biomarker for assessment of COVID-19 prognosis: D-dimer levels on admission and its role in predicting disease outcome in hospitalized patients with COVID-19

Introduction

Coronavirus Disease 2019 is a primarily respiratory illness that can cause thrombotic disorders. Elevation of D-dimer is a potential biomarker for poor prognosis in COVID-19, though optimal cutoff value for D-dimer to predict mortality has not yet been established. This study aims to assess the accuracy of admission D-dimer in the prognosis of COVID-19 and to establish the optimal cutoff D-dimer value to predict hospital mortality.

Methods

Clinical and laboratory parameters and outcomes of confirmed COVID-19 cases admitted to four hospitals in Kathmandu were retrospectively analyzed. Admitted COVID-19 cases with recorded D-dimer and definitive outcomes were included consecutively. D-dimer was measured using immunofluorescence assay and reported in Fibrinogen Equivalent Unit (μg/ml). The receiver operating characteristic curve was used to determine the accuracy of D-dimer in predicting mortality, and to calculate the optimal cutoff value, based on which patients were divided into two groups and predictive value of D-dimer for mortality was measured.

Results

182 patients were included in the study out of which 34(18.7%) died during the hospital stay. The mean admission D-dimer among surviving patients was 1.067 μg/ml (±1.705 μg/ml), whereas that among patients who died was 3.208 μg/ml (±2.613 μg/ml). ROC curve for D-dimer and mortality gave an area under the curve of 0.807 (95% CI 0.728–0.886, p<0.001). Optimal cutoff value for D-dimer was 1.5 μg/ml (sensitivity 70.6%, specificity 78.4%). On Cox proportional hazards regression analysis, the unadjusted hazard ratio for high D-dimer was 6.809 (95% CI 3.249–14.268, p<0.001), and 5.862 (95% CI 2.751–12.489, p<0.001) when adjusted for age.

Conclusion

D-dimer value on admission is an accurate biomarker for predicting mortality in patients with COVID-19. 1.5 μg/ml is the optimal cutoff value of admission D-dimer for predicting mortality in COVID-19 patients.

Elevated Plasma Fibrinogen Is Associated With Excessive Inflammation and Disease Severity in COVID-19 Patients

Background

The coronavirus disease-19 (COVID-19) is characterized with intense inflammatory response, cardiac involvement, and coagulopathy. Fibrinogen, as a biomarker for inflammation, cardiovascular disease, and coagulation, has not been fully investigated yet. The aim of this study was to assess the clinical application of fibrinogen in COVID-19 patients.

Methods

We retrospectively analyzed the demographic and laboratory characteristics of 119 COVID-19 patients in the University of Alabama of Birmingham Medical Center. Correlations of fibrinogen on admission with intensive care unit (ICU) admission, disease severity, and laboratory parameters were analyzed.

Results

Among the 119 COVID-19 patients, 77.3% (92/119) had severe disease, and 59.5% (71/119) patients were admitted to the ICU. Elevated fibrinogen was detected in 67.2% (80/119) of the patients. Fibrinogen levels were significantly associated with inflammatory markers and disease severity, but not with cardiac injury biomarker high sensitivity troponin I. Patients with severe disease had increased fibrinogen levels upon admission compared to patients with non-severe disease (P = 0.001). Fibrinogen level at 528.0 mg/dl was the optimal cutoff to predict disease severity, with a sensitivity and specificity of 66.7% and 70.3% (area undty -60er the curve [AUC] 0.72, P = 0.0006).

Conclusions

Fibrinogen is commonly elevated in COVID-19 patients, especially in those with severe disease. Elevated fibrinogen correlates with excessive inflammation, disease severity, and ICU admission in COVID-19 patients.

Hematologic and coagulopathy parameter as a survival predictor among moderate to severe COVID-19 patients in non- ICU ward: a single-center study at the main referral hospital in Surabaya, East Java, Indonesia

Background : This research aimed to examine and analyze risk factors for death, hematologic parameters and coagulation in COVID-19 patients at RSUD Dr. Soetomo Surabaya, one of the referral centers for probable COVID-19 patient cases in East Java. Method : This was a retrospective analytical study by taking secondary data on patients with probable COVID-19 cases who were treated in hospital isolation rooms from May to September, 2020. Result : Of 538 probable COVID-19 patients, 217  tested positive, with an average age of 52.11±13.12 years, and there were 38 death cases. Hematologic parameters, such as white blood cell, neutrophil and lymphocyte counts, were significantly different in the deceased group. On the other hand, coagulation parameters, consisting of D-dimer, CRP, PT, and aPTT showed significantly similar value in the deceased group. Univatiate analysis concluded that chronic kidney disease, diabetes mellitus, coronary heart disease, WBC, NLR, and PPT counts could predict the mortality, while multivariate analysis revealed that coronary heart disease was the only significant independent predictor of mortality. Conclusion : This research shows that hematologic and coagulation parameters were increased in the majority of COVID-19 patients and the deceased group. While the number of neutrophils and WBC increases, the number of lymphocytes decreases significantly with increasing disease severity. Coronary heart disease is an independent predictor of mortality.

Hematologic and coagulopathy parameter as a survival predictor among moderate to severe COVID-19 patients in non- ICU ward: a single-center study at the main referral hospital in Surabaya, East Java, Indonesia

Background : This research aimed to examine and analyze risk factors for death, hematologic parameters and coagulation in COVID-19 patients at RSUD Dr. Soetomo Surabaya, one of the referral centers for probable COVID-19 patient cases in East Java. Method : This was a retrospective analytical study by taking secondary data on patients with probable COVID-19 cases who were treated in hospital isolation rooms from May to September, 2020. Result : Of 538 probable COVID-19 patients, 217  tested positive, with an average age of 52.11±13.12 years, and there were 38 death cases. Hematologic parameters, such as white blood cell, neutrophil and lymphocyte counts, were significantly different in the deceased group. On the other hand, coagulation parameters, consisting of D-dimer, CRP, PT, and aPTT showed significantly similar value in the deceased group. Univatiate analysis concluded that chronic kidney disease, diabetes mellitus, coronary heart disease, WBC, NLR, and PPT counts could predict the mortality, while multivariate analysis revealed that coronary heart disease was the only significant independent predictor of mortality. Conclusion : This research shows that hematologic and coagulation parameters were increased in the majority of COVID-19 patients and the deceased group. While the number of neutrophils and WBC increases, the number of lymphocytes decreases significantly with increasing disease severity. Coronary heart disease is an independent predictor of mortality.

Hematologic and coagulopathy parameter as a survival predictor among moderate to severe COVID-19 patients in non- ICU ward: a single-center study at the main referral hospital in Surabaya, East Java, Indonesia

Background : This research aimed to examine and analyze risk factors for death, hematologic parameters and coagulation in COVID-19 patients at RSUD Dr. Soetomo Surabaya, one of the referral centers for probable COVID-19 patient cases in East Java. Method : This was a retrospective analytical study by taking secondary data on patients with probable COVID-19 cases who were treated in hospital isolation rooms from May to September, 2020. Result : Of 538 probable COVID-19 patients, 217 were tested positive, with an average age of 52.11±13.12 years, and there were 38 death cases. Hematologic parameters, such as white blood cell, neutrophil and lymphocyte counts, showed significantly different result in the deceased group. On the other hand, coagulation parameters, consisting of D-dimer, CRP, PT, and aPTT showed significantly similar value in the deceased group. Univariate analysis concluded that chronic kidney disease, diabetes mellitus, coronary heart disease, WBC, NLR, and PPT counts could predict the mortality, while multivariate analysis revealed that coronary heart disease was the only significant independent predictor of mortality. Conclusion : This research shows that hematologic and coagulation parameters increased in the majority of COVID-19 patients and the deceased group.  While the number of neutrophils and WBC increases, the number of lymphocytes decreases significantly as the disease gets more severe.. Coronary heart disease is an independent predictor of mortality.

Bleeding risk in hospitalized patients with COVID-19 receiving intermediate- or therapeutic doses of thromboprophylaxis

INTRODUCTION

Some local protocols suggest using intermediate or therapeutic doses of anticoagulants for thromboprophylaxis in hospitalized patients with coronavirus disease 2019 (COVID-19). However, the incidence of bleeding, predictors of major bleeding, or the association between bleeding and mortality remain largely unknown.

METHODS

We performed a cohort study of patients hospitalized for COVID-19 that received intermediate or therapeutic doses of anticoagulants from March 25 to July 22, 2020, to identify those at increased risk for major bleeding. We used bivariate and multivariable logistic regression to explore the risk factors associated with major bleeding.

RESULTS

During the study period, 1965 patients were enrolled. Of them, 1347 (69%) received intermediate- and 618 (31%) therapeutic-dose anticoagulation, with a median duration of 12 days in both groups. During the hospital stay, 112 patients (5.7%) developed major bleeding and 132 (6.7%) had non-major bleeding. The 30-day all-cause mortality rate for major bleeding was 45% (95% confidence interval [CI]: 36%-54%) and for non-major bleeding 32% (95% CI: 24%-40%). Multivariable analysis showed increased risk for in-hospital major bleeding associated with D-dimer levels >10 times the upper normal range (hazard ratio [HR], 2.23; 95% CI, 1.38-3.59), ferritin levels >500 ng/ml (HR, 2.01; 95% CI, 1.02-3.95), critical illness (HR, 1.91; 95% CI, 1.14-3.18), and therapeutic-intensity anticoagulation (HR, 1.43; 95% CI, 1.01-1.97).

CONCLUSIONS

Among patients hospitalized with COVID-19 receiving intermediate- or therapeutic-intensity anticoagulation, a major bleeding event occurred in 5.7%. Use of therapeutic-intensity anticoagulation, critical illness, and elevated D-dimer or ferritin levels at admission were associated with increased risk for major bleeding.

Course of COVID-19 Based on Admission D-Dimer Levels and Its Influence on Thrombosis and Mortality

Background

Arterial and venous thrombosis is one of the major complications of coronavirus disease 2019 (COVID-19) infection. Studies have not assessed the difference in D-dimer levels between patients who develop thrombosis and those who do not.

Methods

Our study retrospectively assessed D-dimer levels in all virus confirmed hospitalized patients between May to September, 2020. Patients were divided into three groups: group 1 with normal D-dimer of < 0.5 µg/mL, group 2 with elevation up to six folds, and group 3 with more than six-fold elevation. Statistical analysis was done using SPSS software 23.0.

Results

Seven hundred twenty patients (group1 (n = 414), group 2 (n = 284) and group 3 (n = 22)) were studied. Eight thrombotic events were observed. Events were two with stroke, two non-ST elevation myocardial infarction and one each of ST elevation myocardial infarction, superior mesenteric artery thrombosis with bowel gangrene, arteriovenous fistula thrombus and unstable angina. No significant difference (P = 0.11) was observed between median D-dimer levels among patients who developed thrombosis (1.34) and those who did not develop thrombosis (0.91). Twenty-nine patients died. The adjusted odds of death among those with a six-fold or higher elevation in D-dimer was 128.4 (95% confidence interval (CI): 14.2 - 446.3, P < 0.001), while adjusted odds of developing clinical thrombosis was 1.96 (95% CI: 0.82 - 18.2, P = 0.18).

Conclusions

Our study observed a 1.1% in-hospital incidence of clinical thrombosis. While, a six-fold elevation in D-dimer was significantly associated with death; the same was not a strong predictor of thrombosis; an observation which implies that dose of anticoagulation should not be based on absolute D-dimer level.

ABC2-SPH risk score for in-hospital mortality in COVID-19 patients: development, external validation and comparison with other available scores

OBJECTIVES

The majority of available scores to assess mortality risk of coronavirus disease 2019 (COVID-19) patients in the emergency department have high risk of bias. Therefore, this cohort aimed to develop and validate a score at hospital admission for predicting in-hospital mortality in COVID-19 patients and to compare this score with other existing ones.

METHODS

Consecutive patients (≥ 18 years) with confirmed COVID-19 admitted to the participating hospitals were included. Logistic regression analysis was performed to develop a prediction model for in-hospital mortality, based on the 3978 patients admitted between March-July, 2020. The model was validated in the 1054 patients admitted during August-September, as well as in an external cohort of 474 Spanish patients.

RESULTS

Median (25-75th percentile) age of the model-derivation cohort was 60 (48-72) years, and in-hospital mortality was 20.3%. The validation cohorts had similar age distribution and in-hospital mortality. Seven significant variables were included in the risk score: age, blood urea nitrogen, number of comorbidities, C-reactive protein, SpO₂/FiO₂ ratio, platelet count, and heart rate. The model had high discriminatory value (AUROC 0.844, 95% CI 0.829-0.859), which was confirmed in the Brazilian (0.859 [95% CI 0.833-0.885]) and Spanish (0.894 [95% CI 0.870-0.919]) validation cohorts, and displayed better discrimination ability than other existing scores. It is implemented in a freely available online risk calculator (https://abc2sph.com/).

CONCLUSIONS

An easy-to-use rapid scoring system based on characteristics of COVID-19 patients commonly available at hospital presentation was designed and validated for early stratification of in-hospital mortality risk of patients with COVID-19.

Incidence, diagnosis, treatment methods, and outcomes of clinically suspected venous thromboembolic disease in patients with COVID-19 in a quaternary hospital in Brazil

BACKGROUND

Prothrombotic states have been associated with viral infections and the novel Sars-COV-2 infection has been associated with elevated D-dimer levels, although no causal relation has been clearly established.

OBJECTIVES

This study presents an epidemiological analysis of manifest VTE episodes in a group of patients hospitalized because of COVID-19.

METHODS

Medical records of patients who presented symptomatic deep vein thrombosis and/or pulmonary embolism in concomitance with confirmed COVID-19 were retrospectively studied. Demographic characteristics, prevalence of VTE, site of occurrence, D-dimer variation over time, management, and outcomes were analyzed.

RESULTS

During the study period, 484 confirmed cases of COVID-19 were admitted, 64 of which displayed VTE symptoms and 13 of which had confirmed symptomatic VTE(2.68% of total sample and 20.31% of symptomatic cases). Most cases (76.92%) occurred in intensive care. On the day attributed to VTE onset, D-dimer levels were over 3,000 ng/mL in 8 (80%) patients, a significant increase from baseline admission levels (p < 0.05). A significant decrease was also observed in D-dimer values at hospital discharge (p < 0.05). All patients received pharmacological thromboprophylaxis and/or anticoagulation as indicated. Two deaths occurred during the study, both patients with severe comorbidities. At the end of our study protocol, nine patients had been discharged and two remained hospitalized, but had no signs of VTE worsening.

CONCLUSIONS

VTE prevalence in hospitalized COVID-19 patients was 2.7%, and higher in intensive care units. Early institution of prophylaxis and immediate full anticoagulation when VTE is diagnosed should be the goals of those who treat this kind of patient.

Clinical Significance of Plasma D-Dimer in COVID-19 Mortality

It is not clear whether D-dimer can be an independent predictor of coronavirus disease 2019 (COVID-19) mortality, and the cut-off of D-dimer for clinical use remains to be determined. Therefore, a comprehensive analysis is still necessary to illuminate the clinical significance of plasma D-dimer in COVID-19 mortality. We searched PubMed, Embase, Cochrane Library, and Scopus databases until November 2020. STATA software was used for all the statistical analyses. The identifier of systematic review registration was PROSPERO CRD42020220927. A total of 66 studies involving 40,614 COVID-19 patients were included in our meta-analysis. Pooled data showed that patients in high D-dimer group had poor prognosis than those in low D-dimer group [OR = 4.52, 95% CI = (3.61, 5.67), P < 0.001; HR = 2.81, 95% CI = (1.85, 4.27), P < 0.001]. Sensitivity analysis, pooled data based on different effect models and the Duval and Tweedie trim-and-fill method did not change the conclusions. Subgroup analyses stratified by different countries, cutoffs, sample size, study design, and analysis of OR/HR still keep consistent conclusions. D-dimer was identified as an independent predictor for COVID-19 mortality. A series of values including 0.5 μg/ml, 1 μg/ml, and 2 μg/ml could be determined as cutoff of D-dimer for clinic use. Measurement and monitoring of D-dimer might assist clinicians to take immediate medical actions and predict the prognosis of COVID-19.

d-dimer and Death in Critically Ill Patients With Coronavirus Disease 2019

OBJECTIVES

Hypercoagulability may be a key mechanism for acute organ injury and death in patients with severe coronavirus disease 2019, but the relationship between elevated plasma levels of d-dimer, a biomarker of coagulation activation, and mortality has not been rigorously studied. We examined the independent association between d-dimer and death in critically ill patients with coronavirus disease 2019.

DESIGN

Multicenter cohort study.

SETTING

ICUs at 68 hospitals across the United States.

PATIENTS

Critically ill adults with coronavirus disease 2019 admitted to ICUs between March 4, 2020, and May 25, 2020, with a measured d-dimer concentration on ICU day 1 or 2.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The primary exposure was the highest normalized d-dimer level (assessed in four categories: < 2×, 2-3.9×, 4-7.9×, and ≥ 8× the upper limit of normal) on ICU day 1 or 2. The primary endpoint was 28-day mortality. Multivariable logistic regression was used to adjust for confounders. Among 3,418 patients (63.1% male; median age 62 yr [interquartile range, 52-71 yr]), 3,352 (93.6%) had a d-dimer concentration above the upper limit of normal. A total of 1,180 patients (34.5%) died within 28 days. Patients in the highest compared with lowest d-dimer category had a 3.11-fold higher odds of death (95% CI, 2.56-3.77) in univariate analyses, decreasing to a 1.81-fold increased odds of death (95% CI, 1.43-2.28) after multivariable adjustment for demographics, comorbidities, and illness severity. Further adjustment for therapeutic anticoagulation did not meaningfully attenuate this relationship (odds ratio, 1.73; 95% CI, 1.36-2.19).

CONCLUSIONS

In a large multicenter cohort study of critically ill patients with coronavirus disease 2019, higher d-dimer levels were independently associated with a greater risk of death.

Characteristics and laboratory findings on admission to the emergency department among 2873 hospitalized patients with COVID-19: the impact of adjusted laboratory tests in multicenter studies. A multicenter study in Spain (BIOCOVID-Spain study)

Identification of predictors for severe disease progression is key for risk stratification in COVID-19 patients. We aimed to describe the main characteristics and identify the early predictors for severe outcomes among hospitalized patients with COVID-19 in Spain. This was an observational, retrospective cohort study (BIOCOVID-Spain study) including COVID-19 patients admitted to 32 Spanish hospitals. Demographics, comorbidities and laboratory tests were collected. Outcome was in-hospital mortality. For analysis, laboratory tests values were previously adjusted to assure the comparability of results among participants. Cox regression was performed to identify predictors. Study population included 2873 hospitalized COVID-19 patients. Nine variables were independent predictors for in-hospital mortality, including creatinine (Hazard ratio [HR]:1.327; 95% Confidence Interval [CI]: 1.040-1.695, p = .023), troponin (HR: 2.150; 95% CI: 1.155-4.001; p = .016), platelet count (HR: 0.994; 95% CI: 0.989-0.998; p = .004) and C-reactive protein (HR: 1.037; 95% CI: 1.006-1.068; p = .019). This is the first multicenter study in which an effort was carried out to adjust the results of laboratory tests measured with different methodologies to guarantee their comparability. We reported a comprehensive information about characteristics in a large cohort of hospitalized COVID-19 patients, focusing on the analytical features. Our findings may help to identify patients early at a higher risk for an adverse outcome.

Similarities and perspectives on the two C's-Cancer and COVID-19

COVID-19 continues to dominate the health-care burden in the twenty-first century. While health-care professionals around the world try their best to minimize the mortality from this pandemic, we also continue to battle the high mortality from different types of cancer. For the hemostasis and thrombosis specialist, these two conditions present some unusual similarities including the high rate of thrombosis and marked elevation of D-dimers. In this forum article, we discuss these similarities and provide some considerations for future research and therapeutic trials.

Increased VWF and Decreased ADAMTS-13 in COVID-19: Creating a Milieu for (Micro)Thrombosis

von Willebrand factor (VWF) is a large adhesive multimeric protein involved in hemostasis. The larger the size (or number of VWF multimers), the greater the functionality of the protein. A deficiency or defect of VWF can lead to von Willebrand disease (VWD) and cause bleeding. Conversely, an increase in VWF may create an environment that promotes thrombosis. ADAMS-13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13), sometimes called VWF-cleaving protease, is primarily responsible for controlling the size of VWF. The most severe deficiency (<10% of normal levels) of ADAMTS-13 arises in thrombotic thrombocytopenic purpura, a condition characterized by the presence of ultralarge VWF and clinically resulting in enhanced risk of thrombosis. However, ADAMTS-13 deficiency may result from other pathological processes. Of relevance is the recent finding that COVID-19 (coronavirus disease 2019) is associated with both increased levels and activity of VWF as well as generally decreased (or occasionally normal) activity levels of ADAMTS-13. Thus, in COVID-19 there is an alteration in the VWF/ADAMTS-13 axis, most often described by increased VWF/ADAMTS-13 ratio (or reduced ADAMTS-13/VWF ratio). COVID-19 is also associated with high prothrombotic risk. Thus, the imbalance of VWF and ADAMTS-13 in COVID-19 may be providing a milieu that promotes (micro)thrombosis, in a clinical picture resembling a secondary thrombotic microangiopathy in some patients. This review therefore assesses the literature on VWF, ADAMTS-13, and COVID-19. Whenever reported in COVID-19, VWF has always been identified as raised (compared with normal reference ranges or control populations). Reports have included VWF level (i.e., VWF antigen) and in some cases one or more VWF "activity" (e.g., collagen binding; platelet glycoprotein Ib [GPIb] binding, using ristocetin cofactor or more modern versions including VWF:GPIbR [recombinant] and VWF:GPIbM [mutant]). Whenever reported, ADAMTS-13 has been reported as "normal" or reduced; however, it should be recognized that "normal" levels may still identify a relative reduction in individual cases. Some reports also discuss the raised VWF/ADAMTS-13 (or reduced ADAMTS-13/VWF) ratio, but very few provide actual numerical data.

International Council for Standardization in Haematology (ICSH) laboratory guidance for the verification of haemostasis analyser-reagent test systems. Part 2: Specialist tests and calibrated assays

Before a new method is used for clinical testing, it is essential that it is evaluated for suitability for its intended purpose. This document gives guidance for the performance, verification and implementation processes required by regulatory and accreditation bodies. It covers the planning and verification of specialist haemostatic tests, including factor assays, D-dimers, direct anticoagulants and thrombophilia testing.