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

Controversies in the Management of Acute Pulmonary Embolism in the Emergency Department

BACKGROUND

Acute pulmonary embolism (PE) is frequently diagnosed in the Emergency Department (ED), and the management approach can be nuanced.

OBJECTIVE

In this narrative review, we synthesize the literature in selected areas of ongoing controversy regarding the diagnostic and management approaches for acute PE in the ED, and provide evidence-based recommendations to empower emergency physicians (EPs) to provide optimal care in these situations.

DISCUSSION

d-Dimer is used to clinically exclude the diagnosis of PE patients who are stratified as low risk. However by utilizing likelihood ratio and with certain scoring tools, patient historically considered moderate or high risk for PE may safely be able to have the diagnosis excluded with a negative d-dimer. Traditional risk stratification and management strategies can be cautiously applied to patients with concomitant Coronavirus-19 infection while awaiting more definitive studies. There is an increasing trend in the diagnosis of isolated subsegmental PE, and many patients receiving this diagnosis may be treated without anticoagulation provided that they have no evidence of associated deep vein thrombosis (DVT) and can be closely followed as an outpatient. There is a persistent hesitancy to discharge patients with newly diagnosed acute PE, and existing well-supported risk stratification tools and clinical decision frameworks can support the EP's decision to safely discharge low-risk patients.

CONCLUSION

tThis review of the literature empowers emergency clinicians to manage challenging PE cases in the ED.

Interest of D-dimer level, severity of COVID-19 and cost of management in Gabon

BACKGROUND

Coronavirus disease 2019 (COVID-19) is strongly associated with an increased risk of thrombotic events, including severe outcomes such as pulmonary embolism. Elevated D-dimer levels are a critical biomarker for assessing this risk. In Gabon, early implementation of anticoagulation therapy and D-dimer testing has been crucial in managing COVID-19. This study hypothesizes that elevated D-dimer levels are linked to increased COVID-19 severity.

AIM

To determine the impact of D-dimer levels on COVID-19 severity and their role in guiding clinical decisions.

METHODS

This retrospective study analyzed COVID-19 patients admitted to two hospitals in Gabon between March 2020 and December 2023. The study included patients with confirmed COVID-19 diagnoses and available D-dimer measurements at admission. Data on demographics, clinical outcomes, D-dimer levels, and healthcare costs were collected. COVID-19 severity was classified as non-severe (outpatients) or severe (inpatients). A multivariable logistic regression model was used to assess the relationship between D-dimer levels and disease severity, with adjusted odds ratios (OR) and 95%CI.

RESULTS

A total of 3004 patients were included, with a mean age of 50.17 years, and the majority were female (53.43%). Elevated D-dimer levels were found in 65.81% of patients, and 57.21% of these experienced severe COVID-19. Univariate analysis showed that patients with elevated D-dimer levels had 3.33 times higher odds of severe COVID-19 (OR = 3.33, 95%CI: 2.84-3.92, P < 0.001), and this association remained significant in the multivariable analysis, adjusted for age, sex, and year of collection. The financial analysis revealed a substantial burden, particularly for uninsured patients.

CONCLUSION

D-dimer predicts COVID-19 severity and guides treatment, but the high cost of anticoagulant therapy highlights the need for policies ensuring affordable access in resource-limited settings like Gabon.

Serial biomarker measurements may be helpful to predict the successful application of high flow nasal cannula in COVID-19 pneumonia patients

High flow nasal cannula (HFNC) can reduce the need for intubation in patients with coronavirus disease-19 (COVID-19) pneumonia induced acute hypoxemic respiratory failure (AHRF), but predictors of HFNC success could be characterized better. C-reactive protein (CRP) and D-dimer are associated with COVID-19 severity and progression. However, no one has evaluated the use of serial CRP and D-dimer ratios to predict HFNC success. We retrospectively studied 194 HFNC-treated patients admitted between August 2020 and October 2022. CRP and D-dimer levels relative to baseline at HFNC initiation were calculated up to three days thereafter. Intubated and non-intubated patient comparisons were assessed by the Kruskal-Wallis rank sum test and t-test. Ninety-two patients were intubated and 102 were not. Median CRP ratios were lower in non-intubated versus intubated patients (0.69 v. 0.96, p = 0.050 for Day 1; 0.49 v. 0.61, p = 0.028 for Day 2; 0.33 v. 0.64, p = 0.008 for Day 3). D-dimer ratios did not change. CRP ratio monitoring in patients with AHRF due to COVID-19 within the first three days of HFNC application can serve as an objective adjunctive clinical tool to identify individuals who can continue to be supported with HFNC without escalating to invasive mechanical ventilation.

The association between mortality due to COVID-19 and coagulative parameters: a systematic review and meta-analysis study

AIMS AND OBJECTIVES

This systematic review and meta-analysis study evaluated the association between mortality due to COVID-19 and coagulative factors.

METHODS

A systematic search was conducted on electronic databases including PubMed, Scopus, and the Web of Science from the beginning of the pandemic until October 2024 to identify relevant studies on COVID-19 patients and their laboratory findings related to coagulation markers and mortality outcome. Eligibility criteria were defined based on the PICO framework, and data extraction was performed by two authors independently using a standardized sheet. Statistical analysis was accomplished using the random effects model, and heterogeneity among studies was assessed using the I2 test. R and RStudio were used for statistical analysis and visualization.

RESULTS

Our systematic literature search yielded 6969 studies, with 48 studies meeting the inclusion criteria for our meta-analysis. The mean platelet count was significantly lower in deceased COVID-19 patients compared to survivors (20.58), while activated partial thromboplastin time (aPTT) and fibrinogen levels did not show significant differences. The pooled mean difference of D-Dimer, International Normalized Ratio (INR), and prothrombin time (PT) were significantly lower in survived patients (-2.45, -0.10, and -0.84, respectively). These findings suggest that platelet count, D-Dimer, INR, and PT may serve as potential indicators of mortality in COVID-19 patients.

CONCLUSION

The results of our systematic review and meta-analysis revealed a significant reduction in the pooled platelet count among deceased individuals when compared to survivors. However, no significant distinctions were observed in the pooled mean activated aPTT and fibrinogen levels between the deceased and survivor groups. On the other hand, there were noticeable variations in the pooled estimated mean of INR, PT, and D-Dimer levels, with significantly higher values in the deceased group compared to those who survived.

mRNA vaccination reduces the thrombotic possibility in COVID-19: Inflammation risk estimates

Thrombosis is a common clinical feature associated with morbidity and mortality in coronavirus disease-2019 (COVID-19) patients. Cytokine storm in COVID-19 increases patients' systemic inflammation, which can cause multiple health consequences. In this work, we aimed to indicate the effect of Pfizer-BioNTech vaccination on the modulation of monocyte chemoattractant protein-3 (MCP-3), matrix metalloproteinase 1 (MMP-1), and tumor necrosis factor-alpha (TNF-α) levels, and other systemic inflammatory biomarkers that associates with COVID-19 severity in patients who suffers from thrombosis consequences. For this purpose, ninety people were collected from Ibn Al-Nafees Hospital and divided into three groups each of which contained 30 people, 15 of them were venous thromboembolism (VTE) positive and the other were VTE negative. The three groups were non-vaccinated COVID-19, vaccinated COVID-19, and control. The levels of MCP-3 and TNF-α were significantly (p < 0.05) increased in vaccinated and non-vaccinated COVID-19 patients regardless of their thrombosis condition, while MMP-1 level was non-significantly (p > 0.05) higher in vaccinated patients compared to control. MCP-3 and TNF-α were correlated positively with D-dimer (r = 0.544 and r = 0.513, respectively) in non-vaccinated patients, while MMP-1 and TNF-α were correlated positively with D-dimer (r = 0.624 and r = 0.575, respectively) in vaccinated patients. The odds ratio of MCP-3 (2.252), MMP-1 (1.062), and TNF-α (1.360) were reduced in vaccinated patients (2.093, 1.022, and 1.301 for MCP-3, MMP-1, and TNF-α respectively). Thus, MCP-3 plays a vital role in COVID-19 pathophysiology, and vaccination can reduce the risk of developing VTE in COVID-19 patients, and improve the inflammatory condition of patients.

Comparison of four D-dimer assays in the context of venous thromboembolism in the emergency department

INTRODUCTION

This observational study conducted across seven emergency care units compares the efficacy of four D-dimer detection methods, namely HemosIL D-dimer HS (HS), HemosIL D-dimer HS-500 (HS-500), VIDAS D-dimer (VIDAS), and HemosIL AcuStar D-dimer (ACUSTAR). The primary focus is on patients with a clinical suspicion of deep venous thrombosis (DVT) or pulmonary embolism (PE).

METHODS

A total of 149 samples were collected from patients with suspected DVT or PE. The confirmation of DVT/PE was based on calf ultrasound or computed tomography-Angiography. Direct comparisons were made between the different detection methods, considering both their analytical performance and clinical utility. Additionally, the impact of an age-adjusted cut-off on the diagnostic accuracy of each method was assessed.

RESULTS

The results revealed comparable negative predictive value, sensitivity, and specificity across the methods, with a notable exception of increased specificity for HS compared with HS-500 (50.8% vs. 41.5%, p = 0.03). Further analysis incorporating an age-adjusted cut-off demonstrated a significant improvement in specificity for HS. When using the age-adjusted cut-off, HS exhibited a substantial increase in specificity compared with HS-500 (63.1% vs. 49.2%, p = 0.004) and demonstrated significantly higher specificity compared with VIDAS (63.1% vs. 53.8%, p = 0.04).

CONCLUSION

The study emphasizes the nonuniversal effect of an age-adjusted cut-off and discusses the potential necessity for different cut-off values, particularly in the case of HS-500. These findings contribute to the understanding of D-dimer detection methods in the context of DVT and PE, providing insights into their relative performances and the potential optimization through age-adjusted cut-offs.

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.

Cardiovascular Comorbidities in COVID-19: Comprehensive Analysis of Key Topics

BACKGROUND

The interrelation between COVID-19 and various cardiovascular and metabolic disorders has been a critical area of study. There is a growing need to understand how comorbidities such as cardiovascular diseases (CVDs) and metabolic disorders affect the risk and severity of COVID-19.

OBJECTIVE

The objective of this study is to systematically analyze the association between COVID-19 and cardiovascular and metabolic disorders. The focus is on comorbidity, examining the roles of CVDs such as embolism, thrombosis, hypertension, and heart failure, as well as metabolic disorders such as disorders of glucose and iron metabolism.

METHODS

Our study involved a systematic search in PubMed for literature published from 2000 to 2022. We established 2 databases: one for COVID-19-related articles and another for CVD-related articles, ensuring all were peer-reviewed. In terms of data analysis, statistical methods were applied to compare the frequency and relevance of MeSH (Medical Subject Headings) terms between the 2 databases. This involved analyzing the differences and ratios in the usage of these terms and employing statistical tests to determine their significance in relation to key CVDs within the COVID-19 research context.

RESULTS

The study revealed that "Cardiovascular Diseases" and "Nutritional and Metabolic Diseases" were highly relevant as level 1 Medical Subject Headings descriptors in COVID-19 comorbidity research. Detailed analysis at level 2 and level 3 showed "Vascular Disease" and "Heart Disease" as prominent descriptors under CVDs. Significantly, "Glucose Metabolism Disorders" were frequently associated with COVID-19 comorbidities such as embolism, thrombosis, and heart failure. Furthermore, iron deficiency (ID) was notably different in its occurrence between COVID-19 and CVD articles, underlining its significance in the context of COVID-19 comorbidities. Statistical analysis underscored these differences, highlighting the importance of both glucose and iron metabolism disorders in COVID-19 research.

CONCLUSIONS

This work lays the foundation for future research that utilizes a knowledge-based approach to elucidate the intricate relationships between these conditions, aiming to develop more effective health care strategies and interventions in the face of ongoing pandemic challenges.

Association of TLR8 Variants in Sex-Based Clinical Differences in Patients with COVID-19

The host immune response might confer differential vulnerability to SARS-CoV-2 infection. The Toll-like receptor 8 (TLR8), could participated for severe COVID-19 outcomes. To investigated the relationship of TLR8 rs3764879-C/G, rs3764880-A/G, and rs3761624-A/G with COVID-19 outcomes and with biochemical parameters. A cross-sectional study of 830 laboratory-confirmed COVID-19 patients was performed, and classified into mild, severe, critical, and deceased outcomes. The TLR8 rs3764879-C/G, rs3764880-A/G, and rs3761624-A/G polymorphisms were genotyped. A logistic regression analysis was performed to determinate the association with COVID-19. A stratified analysis was by alleles was done with clinical and metabolic markets. In all outcomes, men presented the highest ferritin levels compared to women (P < 0.001). LDH levels were significantly different between sex in mild (P = 0.003), severe (P < 0.001) and deceased (P = 0.01) COVID-19 outcomes. The GGG haplotype showed an Odds Ratio of 1.55 (Interval Confidence 95% 1.05-2.32; P = 0.03) in men. Among patients with severe outcome, we observed that the carriers of the GGG haplotype had lower Ferritin, C-reactive protein and LDH levels than the CAA carriers (P < 0.01). After further stratified by sex, these associations were also seen in the male patients, except for D-dimer. Interestingly, among men patients, we could observe associations between TLR8 haplotypes and Ferritin (P < 0.001), D-dimer (P = 0.04), C-reactive protein, and Lactate dehydrogenase in mild (P = 0.04) group. Our results suggest that even though TLR8 haplotypes show a significant association with COVID-19 outcomes, they are associated with clinical markers in COVID-19 severity.

Clinical disease activity is a major determinant of plasma D-dimer elevation in outpatients with rheumatoid arthritis: A hospital-based cross-sectional study

OBJECTIVES

To identify factors associated with plasma D-dimer levels in outpatients with rheumatoid arthritis (RA).

METHODS

We consecutively recruited 460 RA patients who visited our hospital for routine follow-ups between June and October 2021. Plasma D-dimer, RA-related characteristics, comorbidities, and cardiovascular and venous thromboembolism (VTE) risk factors were examined at enrolment. Patients with elevated D-dimer levels underwent whole-leg venous ultrasonography to diagnose deep vein thrombosis (DVT).

RESULTS

Participants had no DVT signs or symptoms. Among them, 252 (54.8%) were positive for plasma D-dimer (≥0.5 μg/ml) and 40 (8.7%) had high D-dimer levels (≥3 μg/ml). The mean was 1.07 μg/ml. After adjustments, age [odds ratio (OR) 1.88 per additional 10 years, P = .003], high and moderate clinical disease activity index (OR 8.79, P < .001), and the presence of comorbidities or cardiovascular/VTE risk factors (OR 2.94, P = .017) were identified as the factors independently associated with high D-dimer levels. Among patients with D-dimer levels ≥3 μg/ml, 10 (25%) had DVT in their lower limbs, and D-dimer levels were significantly higher in patients with DVT compared with those without it (mean 6.0  vs. 4.1 μg/ml, P < .001).

CONCLUSIONS

Clinical disease activity is a major contributor to plasma D-dimer elevation in RA outpatients.

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

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

How artificial intelligence during the pandemic modified the role of a biomarker as d-dimer

Artificial intelligence (AI) was introduced in medicine to make some difficult decision-making regarding diagnostics and/or treatments easy. Its application derives from the improvement of information obtained with computer sciences and informatics, in particular with information derived by algorithms obtained with special informatics support as machine learning. The scenario of hospital changes induced by the COVID-19 pandemic makes easy the application of AI for some clinical updates. Being lung failure with pulmonary embolism is the most common cause of death for inpatients with COVID-19, some biomarkers such as the d-dimer are constantly used associated with other clinical features in order to improve medical assistance. For this reason, d-dimer during the pandemic changed its traditional use for predictive negative value in patients with suspected pulmonary embolism and took relevance for its values giving the chance to change the intensity of anticoagulation for several inpatients. In most cases, according to data reported from several cohorts, these changes improved the morbidity and mortality of a significant percentage of inpatients with COVID-19. The International medical prevention registry on venous thromboembolism and d-dimer and modified sepsis-induced coagulopathy scores were the most used scores derived from AI and dedicated to these clinical aspects in inpatients with COVID-19. Therefore, this review was dedicated to flexible changes that we can use after d-dimer values in different clinical scenarios that vary from disseminated intravascular coagulation to pulmonary embolism to COVID-19.

Circulating Inflammatory Factor Levels in the Early Phase of COVID-19 are Associated with the Progression of Respiratory Failure: A Single-Center Retrospective Study

Purpose

To evaluate the potential relationships between serum interleukin (IL)-2, IL-4, IL-6, IL-10, IL-17, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α levels and occurrence of respiratory failure in patients with early-stage COVID-19 disease.

Patients and Methods

We analyzed clinical characteristics, laboratory parameters, and immunoinflammatory markers in 302 patients diagnosed with SARS-CoV-2 infection who required hospitalization at Changshu Hospital of Nantong University. IL-2, IL-4, IL-6, IL-10, IL-17, IFN-γ, and TNF-α levels in the peripheral blood of patients hospitalized five days after disease onset were measured using multiplex bead-based flow fluorescent immunoassay (MBFFI).

Results

Patients with respiratory failure had higher serum IL-4 [0 (0, 0.54) pg/mL], IL-6 [40.76 (12.33, 90.28) pg/mL], IL-10 [6.65 (4.12, 11.34) pg/mL], and IL-17 [9.48 (4.31, 12.13) pg/mL] levels than patients without respiratory failure (P=0.042, P<0.0001, P=0.012, and P=0.036, respectively). Serum IL-2, IFN-γ, and TNF-α levels were not significantly different between the two groups. The occurrence of respiratory failure was positively correlated with sex (R=0.122, P=0.034), lactic acid (R=0.193, P=0.007), white blood cell count (R=0.121, P=0.038), erythrocyte distribution width (R=0.131, P=0.024), thyrocalcitonin (R=0.280, P<0.0001), and D-dimer levels (R=0.214, P<0.0001) but negatively correlated with oxygen partial pressure (R=-0.208, P=0.004), oxygen saturation (R=-0.220, P=0.002), lymphocyte count (R=-0.129, P=0.026), and calcium (R=-0.152, P=0.042). Among the immunoinflammatory biomarkers, the occurrence of respiratory failure was positively correlated with IL-4 (R=-0.117, P=0.042), IL-6 (R=0.206, P<0.0001), IL-10 (R=0.145, P=0.012), and IL-17 (R=0.121, P=0.036) levels.

Conclusion

Serum levels of pro-inflammatory cytokines IL-6 and IL-17 and anti-inflammatory cytokines IL-4 and IL-10 were significantly elevated in patients with respiratory failure and weakly positively correlated with the occurrence of respiratory failure. Further studies are required to explore these key immune mechanisms to help clinicians better manage acute complications, long-term sequelae, and possible future COVID-19 variants and be flexible in managing future epidemics and similar public health threats.

Systematic review and meta-analysis of within-subject and between-subject biological variation data of coagulation and fibrinolytic measurands

OBJECTIVES

The diagnosis and monitoring of bleeding and thrombotic disorders depend on correct haemostatic measurements. The availability of high-quality biological variation (BV) data is important in this context. Many studies have reported BV data for these measurands, but results are varied. The present study aims to deliver global within-subject (CVI) and between-subject (CVG) BV estimates for haemostasis measurands by meta-analyses of eligible studies, by assessment with the Biological Variation Data Critical Appraisal Checklist (BIVAC).

METHODS

Relevant BV studies were graded by the BIVAC. Weighted estimates for CVI and CVG were obtained via meta-analysis of the BV data derived from BIVAC-compliant studies (graded A-C; whereby A represents optimal study design) performed in healthy adults.

RESULTS

In 26 studies BV data were reported for 35 haemostasis measurands. For 9 measurands, only one eligible publication was identified and meta-analysis could not be performed. 74% of the publications were graded as BIVAC C. The CVI and CVG varied extensively between the haemostasis measurands. The highest estimates were observed for PAI-1 antigen (CVI 48.6%; CVG 59.8%) and activity (CVI 34.9%; CVG 90.2%), while the lowest were observed for activated protein C resistance ratio (CVI 1.5%; CVG 4.5%).

CONCLUSIONS

This study provides updated BV estimates of CVI and CVG with 95% confidence intervals for a wide range of haemostasis measurands. These estimates can be used to form the basis for analytical performance specifications for haemostasis tests used in the diagnostic work-up required in bleeding- and thrombosis events and for risk assessment.

Aprotinin-Drug against Respiratory Diseases

Aprotinin (APR) was discovered in 1930. APR is an effective pan-protease inhibitor, a typical "magic shotgun". Until 2007, APR was widely used as an antithrombotic and anti-inflammatory drug in cardiac and noncardiac surgeries for reduction of bleeding and thus limiting the need for blood transfusion. The ability of APR to inhibit proteolytic activation of some viruses leads to its use as an antiviral drug for the prevention and treatment of acute respiratory virus infections. However, due to incompetent interpretation of several clinical trials followed by incredible controversy in the literature, the usage of APR was nearly stopped for a decade worldwide. In 2015-2020, after re-analysis of these clinical trials' data the restrictions in APR usage were lifted worldwide. This review discusses antiviral mechanisms of APR action and summarizes current knowledge and prospective regarding the use of APR treatment for diseases caused by RNA-containing viruses, including influenza and SARS-CoV-2 viruses, or as a part of combination antiviral treatment.

Coagulopathy and thromboembolic events a pathogenic mechanism of COVID-19 associated with mortality: An updated review

During 2019, the SARS-CoV-2 emerged from China, and during months, COVID-19 spread in many countries around the world. The expanding data about pathogenesis of this virus could elucidate the exact mechanism by which COVID-19 caused death in humans. One of the pathogenic mechanisms of this disease is coagulation. Coagulation disorders that affect both venous and arterial systems occur in patients with COVID-19. The possible mechanism involved in the coagulation could be excessive inflammation induced by SARS-CoV-2. However, it is not yet clear well how SARS-CoV-2 promotes coagulopathy. However, some factors, such as pulmonary endothelial cell damage and some anticoagulant system disorders, are assumed to have an important role. In this study, we assessed conducted studies about COVID-19-induced coagulopathy to obtain clearer vision of the wide range of manifestations and possible pathogenesis mechanisms.

Risk of Thrombosis during and after a SARS-CoV-2 Infection: Pathogenesis, Diagnostic Approach, and Management

Coronavirus disease 2019 (COVID-19) increases the risk of thromboembolic events, especially in patients with severe infections requiring intensive care and cardiorespiratory support. COVID-19 patients with thromboembolic complications have a higher risk of death, and if they survive, these complications are expected to negatively affect these patients’ quality of life. Moreover, recent data reported that the risk of thromboembolism remains high months after a COVID-19 infection. Therefore, understanding the pathogenesis of thrombosis in the setting of COVID-19 may facilitate the early prevention and treatment of COVID-19-associated thromboembolism to reduce concomitant morbidity, mortality, and disability. This review will first discuss the clinical characteristics of COVID-19 infections, particularly with regard to the underlying pathophysiology. Then, the pathogenesis of COVID-19-associated thrombosis at the molecular and cellular levels will be comprehensively reviewed. Next, the clinical manifestations of venous and arterial thromboembolism in COVID-19 as well as the potential benefits of several laboratory markers of thrombosis will be further discussed. Lastly, the preventive and therapeutic management of thromboembolism during and after COVID-19 will also be explained.

D-dimer trends elaborate the heterogeneity of risk in hospitalized patients with COVID-19: A multi-national case series from different waves

Introduction

Variable D-dimer trends during hospitalization reportedly result in distinct in-hospital mortality. In this multinational case series from the first and second waves, we show the universality of such D-dimer trends.

Methods

We reviewed 405 patients with COVID-19 during the first wave admitted to three institutions in the United States, Italy, and Colombia, and 111 patients admitted to the U.S. site during the second wave and 55 patients during the third wave. D-dimer was serially followed during hospitalization.

Results

During the first wave, 66 (15%) patients had a persistently-low pattern, 33 (8%) had early-peaking, 70 (16%) had mid-peaking, 94 (22%) had fluctuating, 30 (7%) had late-peaking, and 112 (26%) had a persistently-high pattern. During the second and third waves, similar patterns were observed. D-dimer patterns were significantly different in terms of in-hospital mortality similarly in all waves. Patterns were then classified into low-risk patterns (persistently-low and early-peaking), where no deaths were observed in both waves, high-risk patterns (mid-peaking and fluctuating), and malignant patterns (late-peaking and persistently-high). Overall, D-dimer trends were associated with an increased risk for in-hospital mortality in the first wave (overall: HR: 1.73) and stayed the same during the second (HR: 1.67, p &lt; 0.001) and the third (HR: 4.4, p = 0.001) waves.

Conclusion

D-dimer behavior during COVID-19 hospitalization yielded universal categories with distinct mortality risks that persisted throughout all studied waves of infection. Monitoring D-dimer behavior may be useful in the management of these patients.

Extracellular Vesicle-Based SARS-CoV-2 Vaccine

Messenger ribonucleic acid (RNA) vaccines are mainly used as SARS-CoV-2 vaccines. Despite several issues concerning storage, stability, effective period, and side effects, viral vector vaccines are widely used for the prevention and treatment of various diseases. Recently, viral vector-encapsulated extracellular vesicles (EVs) have been suggested as useful tools, owing to their safety and ability to escape from neutral antibodies. Herein, we summarize the possible cellular mechanisms underlying EV-based SARS-CoV-2 vaccines.

[Pulmonary embolism in neurosurgical patients]

Pulmonary embolism (PE) is a serious problem for neurosurgical patients because of high risk of mortality and the need to choose effective and safe anticoagulation.

OBJECTIVE

To analyze the patients with PE after neurosurgical interventions.

MATERIAL AND METHODS

A prospective study was performed at the Burdenko Neurosurgical Center between January 2021 and December 2022. Inclusion criteria were neurosurgical disease and PE.

RESULTS

In accordance with inclusion criteria, we analyzed 14 patients. Mean age was 63 [45.8; 70.0] years. Four patients died. PE was a direct cause of death in 1 case. PE occurred in 5.14±3.68 days after surgery. Anticoagulation was safely implemented in 3 patients with PE on the first day after craniotomy. In a patient with massive PE several hours after craniotomy, anticoagulation resulted hematoma with brain dislocation and death. Thromboextraction and thrombodestruction were used in 2 patients with massive PE and high risk of mortality.

CONCLUSION

Despite low incidence (0.1%), PE is a serious problem in neurosurgical patients due to the risk of intracranial hematoma under effective anticoagulant therapy. In our opinion, endovascular interventions with thromboextraction, thrombodestruction or local fibrinolysis are the safest in the treatment of PE after neurosurgery. Individual approach considering clinical, laboratory data, advantages and disadvantages of a particular anticoagulant drug is required when choosing the tactics of anticoagulation. Further analysis of a larger number of clinical cases is needed to develop the guidelines for the management of neurosurgical patients with PE.

D-dimer Testing in Pulmonary Embolism with a Focus on Potential Pitfalls: A Narrative Review

D-dimer is a multifaceted biomarker of concomitant activation of coagulation and fibrinolysis, which is routinely used for ruling out pulmonary embolism (PE) and/or deep vein thrombosis (DVT) combined with a clinical pretest probability assessment. The intended use of the tests depends largely on the assay used, and local guidance should be applied. D-dimer testing may suffer from diagnostic errors occurring throughout the pre-analytical, analytical, and post-analytical phases of the testing process. This review aims to provide an overview of D-dimer testing and its value in diagnosing PE and discusses the variables that may impact the quality of its laboratory assessment.