Pulmonary embolism: A complication of COVID 19 infection

Before and after COVID-19: Changes in symptoms and diagnoses in 13,033 adults

BACKGROUND

Most patients with COVID-19 report experiencing one or more symptoms after acute infection subsides, known as post-acute sequelae of SARS-CoV-2 infection (PASC). Though research has examined PASC after acute COVID-19, few studies have examined PASC over a longer follow-up duration or accounted for rates of symptoms and diagnoses before COVID-19 infection, and included those not actively seeking treatment for PASC. To determine what symptoms and diagnoses are occurring at higher rates after acute COVID-19 infection from a more inclusive sample, we extracted electronic hospital records (EHR) data from 13,033 adults with previously known diagnoses and symptoms.

METHODS

The sample was comprised of patients who had a positive PCR test for SARS-CoV-2 between March 1, 2020, and December 31, 2020, and follow-up was conducted through November 29, 2021. All patients in the sample had medical appointments ≥4 weeks before and ≥4 weeks after their positive PCR test. At these appointments, all ICD-10 codes recorded in the EHR were classified into 21 categories based on the literature and expert review. Conditional logistic regression models were used to quantify the odds of these symptoms and diagnostic categories following COVID-19 infection relative to visits occurring before infection. The sample was comprised of 28.0% adults over 65 and was 57.0% female. After the positive PCR test, the most recorded diagnoses and symptoms were dyspnea and respiratory failure, myositis, musculoskeletal pain/stiffness, anxiety, and depression.

RESULTS

Results from regression analyses showed increased odds of diagnosis for 15 of the 21 categories following positive PCR. Relative to pre-COVID, the diagnoses and symptoms with the greatest odds after a positive PCR test were loss of smell or taste [OR (95% CI) = 6.20 (3.18-12.09)], pulmonary fibrosis [3.50 (1.59-7.68)], and dyspnea/respiratory failure [2.14 (1.92-2.40)]. Stratification of these analyses by age, gender, race, and ethnicity showed similar results.

CONCLUSION

The increased symptoms and diagnoses detected in the current study match prior analyses of PASC diagnosis and treatment-seeking patients. The current research expands upon the literature by showing that these symptoms are more frequently detected following acute COVID-19 than before COVID-19. Further, our analyses provide a broad snapshot of the population as we were able to describe PASC among all patients who tested positive for COVID-19.

Extensive Iliocaval Deep Vein Thrombosis Provoked by Coronavirus Disease 2019 (COVID-19) in the Setting of an Inferior Vena Cava Filter

Thrombotic events are well-known complications of coronavirus disease 2019 (COVID-19). Inferior vena cava filters (IVCF) are devices used to prevent pulmonary embolism (PE) and also increase the risk of thrombotic complications. Here, we describe the case of a 38-year-old female with extensive bilateral lower extremity deep vein thrombosis (DVT) and thrombosis of the infrarenal inferior vena cava (IVC) in the setting of an IVCF and symptomatic COVID-19. The IVCF had been placed a few months prior for a left femoral DVT and PE after spinal surgery. This patient was treated with pharmacomechanical thrombectomy and ultrasound-assisted thrombolysis followed by angioplasty and anticoagulation. The IVCF was retrieved after confirming there was no residual DVT when the patient recovered from COVID-19 infection. This case of a rare combination of IVCF-related thrombosis secondary to COVID-19 highlights the potential pitfalls of IVCF in this situation.

CTPA ordering trends in local emergency departments: are they increasing and did they increase as a result of COVID-19?

PURPOSE

Ordering trends for computed tomographic pulmonary angiogram (CTPA) studies by local emergency departments were assessed, along with the impact of the COVID-19 pandemic on these ordering trends and CTPA positivity rates.

METHODS

A retrospective quantitative analysis was performed on all CTPA studies ordered between February 2018 - January 2022 by three local tertiary care emergency rooms to investigate for pulmonary embolism. Data collected from the first two years of the COVID-19 pandemic was compared to the two years prior to the pandemic to assess for significant changes in ordering trends and positivity rates.

RESULTS

The overall number of CTPA studies ordered increased from 534 studies in 2018-2019 to 657 in 2021-2022 and the rate of positive diagnosis of acute pulmonary embolism varied between 15.8% to 19.5% over the four years studied. There was no statistically significant difference in the number of CTPA studies ordered when comparing the first two years of the COVID-19 pandemic to the two years immediately prior; however, the positivity rate was significantly higher during the first two years of the pandemic.

CONCLUSION

Over the studied period from 2018-2022, the overall number of CTPA studies ordered by local emergency departments has increased, in line with literature reports from other locations. There was also a correlation between the onset of the COVID-19 pandemic and CTPA positivity rates, possibly secondary to the prothrombotic nature of this infection or the increase in sedentary lifestyles during lockdown periods.

Tracheostomy insertion in COVID-19: insertion practice and factors leading to unplanned tube exchange

Background

Tracheostomy insertion in patients with coronavirus disease 2019 (COVID-19) presents unique challenges. Patients frequently have high ventilatory requirements, and as an aerosol generating procedure, tracheostomy insertion creates the potential for staff transmission. Problems with tracheostomies contribute to morbidity and mortality, and tracheostomy changes may increase risks of staff transmission. We sought to quantify the incidence of clinically necessitated tracheostomy changes, establish the indications for change and investigate the incidence of staff transmission.

Methods

We conducted a single institution, retrospective, observational cohort study of all intensive care unit (ICU) patients with COVID-19 who had a tracheostomy between March 2020 and April 2021. The institution is a large tertiary referral centre in Ireland.

Results

Forty-three patients had a tracheostomy during the study period. All were a Shiley™ Flexible Adult Taperguard or Shiley™ XLT Tracheostomy. 14 patients (33%) required a tracheostomy change, with the majority (57%) involving a change from a standard size to an extended length tracheostomy. Persistent leak was the most common indication for change (71.6%). Other indications included patient-ventilator dyssynchrony, persistent cough and accidental decannulation. No staff transmission of COVID-19 occurred during this study.

Conclusions

The incidence of tracheostomy change was 33%, highlighting the importance of selecting the right tracheostomy for each patient. We discuss how key characteristics of tracheostomies such as type, size, length and inner diameter may impact flow, resistance and work of breathing, leading to unplanned tracheostomy change. No staff transmission occurred arising from tracheostomy insertion, adding to increasing evidence that tracheostomy insertion in COVID-19 appears safe with adherence to guidelines describing the correct use of personal protective equipment.

Cardiovascular implications of the COVID-19: Management of complications and drug safety concerns

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, has rapidly spread worldwide and has been infected more than 219 million individuals with 4.55 million deaths worldwide as of September 2021, causing a pandemic. Preexisting cardiovascular (CV) comorbidities such as hypertension, diabetes, and coronary artery disease seem to be associated with greater severity of infection, worse prognosis, and higher mortality. Moreover, COVID-19 can contribute to CV complications, including acute myocardial injury, arrhythmia, acute coronary syndrome, and venous thromboembolism, emphasizing the importance of precocious detection and implementation of optimal therapeutic strategies. This review provides an overview of evidence-based data of CV complications of COVID-19, focusing on their management strategies, as well as potential cardiac adverse effects and drug interactions, due to off-label and investigational drugs used for the treatment of COVID-19.

Circulating cell clusters aggravate the hemorheological abnormalities in COVID-19

Microthrombi and circulating cell clusters are common microscopic findings in patients with coronavirus disease 2019 (COVID-19) at different stages in the disease course, implying that they may function as the primary drivers in disease progression. Inspired by a recent flow imaging cytometry study of the blood samples from patients with COVID-19, we perform computational simulations to investigate the dynamics of different types of circulating cell clusters, namely white blood cell (WBC) clusters, platelet clusters, and red blood cell clusters, over a range of shear flows and quantify their impact on the viscosity of the blood. Our simulation results indicate that the increased level of fibrinogen in patients with COVID-19 can promote the formation of red blood cell clusters at relatively low shear rates, thereby elevating the blood viscosity, a mechanism that also leads to an increase in viscosity in other blood diseases, such as sickle cell disease and type 2 diabetes mellitus. We further discover that the presence of WBC clusters could also aggravate the abnormalities of local blood rheology. In particular, the extent of elevation of the local blood viscosity is enlarged as the size of the WBC clusters grows. On the other hand, the impact of platelet clusters on the local rheology is found to be negligible, which is likely due to the smaller size of the platelets. The difference in the impact of WBC and platelet clusters on local hemorheology provides a compelling explanation for the clinical finding that the number of WBC clusters is significantly correlated with thrombotic events in COVID-19 whereas platelet clusters are not. Overall, our study demonstrates that our computational models based on dissipative particle dynamics can serve as a powerful tool to conduct quantitative investigation of the mechanism causing the pathological alterations of hemorheology and explore their connections to the clinical manifestations in COVID-19.

Venous thromboembolism in COVID-19: A meta-summary of cases

OBJECTIVES

To summarize cases of venous thromboembolism (VTE), including pulmonary embolism (PE) and deep vein thrombosis (DVT) among coronavirus disease (COVID-19) patients and discuss their symptoms, diagnostic method, clinical features, and prognosis.

METHODS

All major databases were searched for relevant studies published between December 1, 2019 and May 5, 2021.

RESULTS

A total of 233 articles were identified, 22 describing 48 patients were included. A total of 79.1% had PE and 20.9% had DVT. Most patients were men, with a mean age of 56 years. Comorbidities were present in 70.8%, and 85.4% had at least one risk factor of VTE. 56.3% had received anticoagulation therapy. Most patients were treated in the general ward. Complications occurred in 27.1% of the patients, and recovery was achieved in 80.4%.

CONCLUSION

Venous thromboembolism must be suspected even in patients who had received prior anticoagulant regimens or in stable cases, especially in males, the elderly, and patients with comorbidities and high D-dimer levels.

Hereditary Thrombophilia in the Era of COVID-19

Thrombophilia, also called hypercoagulability or prothrombotic condition, usually reflects a certain imbalance that occurs either in the coagulation cascade or in the anticoagulation/fibrinolytic system. A similar imbalance may be induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Thrombotic complications are associated with multiorgan failure and increased mortality. In this context, activation of coagulation and thrombocytopenia appeared as prognostic markers in COVID-19. Our work provides a structured and updated analysis of inherited thrombophilia and its involvement in COVID-19, emphasizing the importance of diagnosing and initiating thromboprophylaxis. Since the state of hypercoagulation is directly correlated with COVID-19, we consider that studies on the genetic profiles of proteins involved in thrombophilia in patients who have had COVID-19 and thrombotic events are of great importance, both in treating and in preventing deaths due to COVID-19.

Role of LL-37 in thrombotic complications in patients with COVID-19

Blood clot formation induced by dysfunctional coagulation is a frequent complication of coronavirus disease 2019 (COVID-19) and a high-risk factor for severe illness and death. Neutrophil extracellular traps (NETs) are implicated in COVID-19-induced immunothrombosis. Furthermore, human cathelicidin, a NET component, can perturb the interaction between the SARS-CoV-2 spike protein and its ACE2 receptor, which mediates viral entry into cells. At present, however, the levels of cathelicidin antimicrobial peptides after SARS-CoV-2 infection and their role in COVID-19 thrombosis formation remain unclear. In the current study, we analyzed coagulation function and found a decrease in thrombin time but an increase in fibrinogen level, prothrombin time, and activated partial thromboplastin time in COVID-19 patients. In addition, the cathelicidin antimicrobial peptide LL-37 was upregulated by the spike protein and significantly elevated in the plasma of patients. Furthermore, LL-37 levels were negatively correlated with thrombin time but positively correlated with fibrinogen level. In addition to platelet activation, cathelicidin peptides enhanced the activity of coagulation factors, such as factor Xa (FXa) and thrombin, which may induce hypercoagulation in diseases with high cathelicidin peptide levels. Injection of cathelicidin peptides promoted the formation of thrombosis, whereas deletion of cathelicidin inhibited thrombosis in vivo. These results suggest that cathelicidin antimicrobial peptide LL-37 is elevated during SARS-CoV-2 infection, which may induce hypercoagulation in COVID-19 patients by activating coagulation factors.

Cardiopulmonary Resuscitation Outcomes of Patients with COVID-19; a One-Year Survey

INTRODUCTION

Assessing cardiopulmonary resuscitation (CPR) outcomes of patients with COVID-19 and employing effective strategies for their improvement are essential. This study is designed in this regard.

METHODS

This cross-sectional study was conducted between January 20, 2020 and January 20, 2021 in the emergency departments of two hospitals in Hamadan and Kermanshah, Iran. Participants were 487 patients with confirmed COVID-19 and cardiac arrest (CA) who had undergone CPR during the study period. Data were collected using the available CPR documentation forms developed based on the Utstein Style and analyses were performed using Chi-square, Fisher's exact, and Mann-Whitney U tests and the logistic regression analysis.

RESULTS

Participants' mean age was 69.31±14.73 years and most of them were male (61.8%) and suffered from at least one underlying disease (58.1%). The rate of total and in-hospital CA was 9.67% and 9.39%, respectively. The most prevalent first documented rhythm was asystole (67.9%) and the highest responsivity to CPR was for shockable rhythms. The rate of the return of spontaneous circulation (ROSC) was 9% and the rate of survival to hospital discharge was 2%. The significant predictors of CPR success were age (p = 0.035), epinephrine administration time interval (p = 0.00), CPR duration (p = 0.00), and First documented rhythm (p = 0.009).

CONCLUSION

The rate of in-hospital CA among studied COVID-19 cases was 9.39% with 9% ROSC and 2% survival to hospital discharge rates after CPR. Primary CPR success among patients with COVID-19 was poor, particularly among those with asystole and bradycardia. It seems that old age and improper doses of epinephrine can reduce CPR success.

Incidence of thrombotic complications in COVID-19 : On behalf of ICODE: The International COVID-19 Thrombosis Biomarkers Colloquium

A high incidence of thrombosis in hospitalised patients with COVID-19 was identified early during the pandemic. Accurately quantifying thrombotic risk may assist prognosis and guide appropriate thromboprophylaxis. Observational studies have estimated the rate of thrombosis in both hospitalised and non-hospitalised patients with COVID-19, and how this corresponds to the severity of illness. In this review, we provide an overview of the incidence and prevalence of arterial and venous thrombotic events in patients with COVID-19 and highlight the limitations in the studies to date. Asymptomatic individuals with COVID-19 and those with mild symptoms are at very low risk of thrombotic complications. However, rates of thrombosis are substantially increased in hospitalised patients, and are strikingly high in those patients who are critically-ill requiring treatment on the intensive care unit and especially those requiring extracorporeal membrane oxygenation. Clinicians managing such patients need to be aware of these risks and take appropriate steps with respect to thromboprophylaxis and heightened clinical vigilance. Large prospective observational studies will more accurately quantify thrombotic rate, and randomized controlled trials are currently investigating optimal thromboprophylactic strategies.

Mechanisms of Immunothrombosis by SARS-CoV-2

SARS-CoV-2 contains certain molecules that are related to the presence of immunothrombosis. Here, we review the pathogen and damage-associated molecular patterns. We also study the imbalance of different molecules participating in immunothrombosis, such as tissue factor, factors of the contact system, histones, and the role of cells, such as endothelial cells, platelets, and neutrophil extracellular traps. Regarding the pathogenetic mechanism, we discuss clinical trials, case-control studies, comparative and translational studies, and observational studies of regulatory or inhibitory molecules, more specifically, extracellular DNA and RNA, histones, sensors for RNA and DNA, as well as heparin and heparinoids. Overall, it appears that a network of cells and molecules identified in this axis is simultaneously but differentially affecting patients at different stages of COVID-19, and this is characterized by endothelial damage, microthrombosis, and inflammation.

Systemic inflammation in COVID‐19 patients may induce various types of venous and arterial thrombosis: A systematic review

COVID‐19 is a global pandemic with a daily increasing number of affected individuals. Thrombosis is a severe complication of COVID‐19 that leads to a worse clinical course with higher rates of mortality. Multiple lines of evidence suggest that hyperinflammation plays a crucial role in disease progression. This review compiles clinical data of COVID‐19 patients who developed thrombotic complications to investigate the possible role of hyperinflammation in inducing hypercoagulation. A systematic literature search was performed using PubMed, Embase, Medline and Scopus to identify relevant clinical studies that investigated thrombotic manifestations and reported inflammatory and coagulation biomarkers in COVID‐19 patients. Only 54 studies met our inclusion criteria, the majority of which demonstrated significantly elevated inflammatory markers. In the cohort studies with control, D‐dimer was significantly higher in COVID‐19 patients with thrombosis as compared to the control. Pulmonary embolism, deep vein thrombosis and strokes were frequently reported which could be attributed to the hyperinflammatory response associated with COVID‐19 and/or to the direct viral activation of platelets and endothelial cells, two mechanisms that are discussed in this review. It is recommended that all admitted COVID‐19 patients should be assessed for hypercoagulation. Furthermore, several studies have suggested that anticoagulation may be beneficial, especially in hospitalized non‐ICU patients. Although vaccines against SARS‐CoV‐2 have been approved and distributed in several countries, research should continue in the field of prevention and treatment of COVID‐19 and its severe complications including thrombosis due to the emergence of new variants against which the efficacy of the vaccines is not yet clear.

Case Report: An Unusual Case of Biventricular Thrombosis in a COVID-19 Patient With Ischemic Dilated Cardiomyopathy: Assessment of Mass Mobility and Embolic Risk by Tissue Doppler Imaging

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein binds to angiotensin-converting enzyme 2 (ACE2) receptor on vascular cells. As a consequence, patients with COVID-19 have an increased incidence of thromboembolic complications of the SARS-CoV-2 infection and subsequent endothelial cell damage with consequence of development of systemic vasculitis and diffuse intravascular coagulation. The present case describes a COVID-19 female patient with ischemic dilated cardiomyopathy, who presented with congestive heart failure and echocardiographic evidence of biventricular apical thrombi. The peak antegrade longitudinal velocity (Va) of each thrombotic mass was measured by pulsed wave tissue Doppler imaging (PW-TDI). Both left ventricular and right ventricular apical thrombi were found with a TDI-derived mass peak Va < 10 cm/s. There was no clinical evidence of neither systemic nor pulmonary embolization, probably due to the hypomobility of both left and right ventricular masses.

Thromboembolic Complications of SARS-CoV-2 and Metabolic Derangements: Suggestions from Clinical Practice Evidence to Causative Agents

Severe Acute Respiratory Syndrome (SARS) Coronavirus (CoV)-2 is a recently identified positive sense single-strand RNA (ssRNA) β-coronavirus. The viral spike proteins infect human hosts by binding to the cellular receptor angiotensin-converting enzyme 2 (ACE2). The infection causes a systemic illness involving cell metabolism. This widespread involvement is implicated in the pathophysiology of the illness which ranges from mild to severe, requiring multi organ support, ranging from oxygen supplementation to full cardiovascular and respiratory support. Patients with multiple co-existing comorbidities are also at a higher risk. The aim of this review is to explore the exact mechanisms by which COVID-19 affects patients systemically with a primary focus on the bleeding and thrombotic complications linked with the disease. Issues surrounding the thrombotic complications following administration of the ChAdOx1 nCoV-19 (Astra-Zeneca-Oxford) vaccine have also been illustrated. Risk stratification and treatment options in these patients should be tailored according to clinical severity with input from a multidisciplinary team.

The Impact of COVID-19 on Vascular Surgery Practice: A Systematic Review

BACKGROUND

COVID-19 is characterized by a pulmonary interstitial compromise which can require intensive care unit (ICU) and mechanical ventilation. Covid patients develop a wide range of pathologies. This study aims to identify the impact of COVID-19 in diseases commonly treated by vascular surgeons.

METHODS

Four conditions were selected: venous thromboembolism (VTE), pulmonary embolism (PE), peripheral arterial disease (PAD), and microangiopathy. A systematic review of the literature using PRISMA guidelines was.

RESULTS

Out of 1195 papers reviewed for conditions in COVID-19 patients relevant to routine vascular surgery practice, 43 papers were included and analyzed. Venous thrombosis was found to be the most common COVID-19 associated pathology with a cumulative incidence of 25% at 7 days and 48% at 14 days. Additionally, D-dimer levels proved to be a good predictor, even in the early stages of the disease with a sensitivity of 85%, specificity of 88.5% and a negative predictive value of 94.7%. Patients in the ICU demonstrated a significantly higher risk of developing VTE, even when receiving pharmacologic thromboprophylaxis. Although evidence of arterial thrombosis was less common (1% to 16.3%), its consequences were typically more serious, including limb loss and death even in young individuals (OR = 25, 95% CI). Finally, microangiopathy has a wide spectrum of clinical presentations from retinal microangiopathy to other more severe manifestations such as myocardial injury, pulmonary compromise and potential multiple organ dysfunction syndrome.

CONCLUSIONS

Although the pathophysiological pathway by which COVID-19 produces thrombosis is not completely clear, the incidence of both arterial and venous thrombosis is increased. D-dimer screening should be done in all COVID-19 patients, as a predictor of thrombotic complications.

A Review of Venous Thromboembolism Phenomena in COVID-19 Patients

With the outbreak of the second peak of COVID-19 in many countries of the world, the symptoms and complications of this disease has received a great deal of attention. One of the most important known complications of severe acute respiratory syndrome coronavirus 2 is the occurrence of venous thromboembolic events, especially in critically ill patients who are hospitalized in the intensive care unit. The pathology of this event is complex and multifactorial, but the main problem now is the timely diagnosis of these phenomena, which can reduce the mortality and morbidity of patients. Deterioration of clinical condition in patients with severe acute respiratory syndrome coronavirus 2 infection along with increased coagulation markers can increase clinical suspicion of venous thromboembolic events. Imaging techniques, especially computed tomography pulmonary angiography, can well solve this puzzle and lead to timely treatment of these patients.

Unexpected high frequency of early mortality in COVID-19: a single-centre experience during the first wave of the pandemic

We report the high frequency of early mortality in COVID‐19 patients (48.6% of 72 deaths). Early deaths were not explained by differences in age, sex and comorbidities, but they had a more severe disease at hospital admission compared with late deaths. These data highlight the importance of outpatient monitoring for the early identification of COVID‐19 patients who require hospital admission.

Incidence of symptomatic venous thromboembolism following hospitalization for coronavirus disease 2019: Prospective results from a multi-center study

BACKGROUND

Thrombosis and pulmonary embolism appear to be major causes of mortality in hospitalized coronavirus disease 2019 (COVID-19) patients. However, few studies have focused on the incidence of venous thromboembolism (VTE) after hospitalization for COVID-19.

METHODS

In this multi-center study, we followed 1529 COVID-19 patients for at least 45 days after hospital discharge, who underwent routine telephone follow-up. In case of signs or symptoms of pulmonary embolism (PE) or deep vein thrombosis (DVT), they were invited for an in-hospital visit with a pulmonologist. The primary outcome was symptomatic VTE within 45 days of hospital discharge.

RESULTS

Of 1529 COVID-19 patients discharged from hospital, a total of 228 (14.9%) reported potential signs or symptoms of PE or DVT and were seen for an in-hospital visit. Of these, 13 and 12 received Doppler ultrasounds or pulmonary CT angiography, respectively, of whom only one patient was diagnosed with symptomatic PE. Of 51 (3.3%) patients who died after discharge, two deaths were attributed to VTE corresponding to a 45-day cumulative rate of symptomatic VTE of 0.2% (95%CI 0.1%-0.6%; n = 3). There was no evidence of acute respiratory distress syndrome (ARDS) in these patients. Other deaths after hospital discharge included myocardial infarction (n = 13), heart failure (n = 9), and stroke (n = 9).

CONCLUSIONS

We did not observe a high rate of symptomatic VTE in COVID-19 patients after hospital discharge. Routine extended thromboprophylaxis after hospitalization for COVID-19 may not have a net clinical benefit. Randomized trials may be warranted.

Coagulopathy and Thrombosis as a Result of Severe COVID-19 Infection: A Microvascular Focus

Coronavirus disease of 2019 (COVID-19) is the clinical manifestation of the respiratory infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While primarily recognized as a respiratory disease, it is clear that COVID-19 is systemic illness impacting multiple organ systems. One defining clinical feature of COVID-19 has been the high incidence of thrombotic events. The underlying processes and risk factors for the occurrence of thrombotic events in COVID-19 remain inadequately understood. While severe bacterial, viral, or fungal infections are well recognized to activate the coagulation system, COVID-19-associated coagulopathy is likely to have unique mechanistic features. Inflammatory-driven processes are likely primary drivers of coagulopathy in COVID-19, but the exact mechanisms linking inflammation to dysregulated hemostasis and thrombosis are yet to be delineated. Cumulative findings of microvascular thrombosis has raised question if the endothelium and microvasculature should be a point of investigative focus. von Willebrand factor (VWF) and its protease, a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS-13), play important role in the maintenance of microvascular hemostasis. In inflammatory conditions, imbalanced VWF-ADAMTS-13 characterized by elevated VWF levels and inhibited and/or reduced activity of ADAMTS-13 has been reported. Also, an imbalance between ADAMTS-13 activity and VWF antigen is associated with organ dysfunction and death in patients with systemic inflammation. A thorough understanding of VWF-ADAMTS-13 interactions during early and advanced phases of COVID-19 could help better define the pathophysiology, guide thromboprophylaxis and treatment, and improve clinical prognosis.

COVID-19, thromboembolic risk, and Virchow's triad: Lesson from the past

COronavirus Infectious Disease which started in 2019 (COVID-19) usually presents with the signs and symptoms of pneumonia. However, a growing number of recent reports highlight the fact that the infection may be by far more than only a respiratory disease. There is evidence of an increased thromboembolic risk in COVID-19 patients, with a variety of manifestations in terms of ischemic stroke, deep vein thrombosis, acute pulmonary embolism, acute myocardial infarction, systemic arterial embolism, and placental thrombosis. The German physician Rudolph Virchow, about two centuries ago, described three pivotal factors contributing together to thromboembolic risk: endothelial injury, hypercoagulability, and blood stasis. COVID-19-associated hypercoagulability is unique and distinctive, and has its own features involving the immune system. Many of the drugs proposed and currently undergoing evaluation for the treatment of COVID-19 have one or more of the Virchow's triad elements as a target. The three factors outlined by Virchow are still able to explain the venous and arterial hypercoagulable state in the dramatic COVID-19 setting. Nowadays, we have decidedly more sophisticated diagnostic tools than Virchow had, but many of the challenges that we are facing are the same as Virchow faced in the 19th century.

Development of pulmonary embolism in a nonhospitalized patient with COVID-19 who did not receive venous thromboembolism prophylaxis

PURPOSE

Coronavirus disease 2019 (COVID-19) has been associated with thrombotic complications such as stroke and venous thromboembolism (VTE), and VTE prophylaxis for hospitalized patients with COVID-19 is recommended. However, extended postdischarge VTE prophylaxis and VTE prophylaxis for nonhospitalized patients with COVID-19 are not routinely recommended due to uncertain benefit in these populations.

SUMMARY

Here we report development of a pulmonary embolism (PE) in a young patient without other VTE risk factors who was treated for COVID-19 in an emergency department (ED) and discharged home without VTE prophylaxis, which was consistent with current recommendations. The patient presented to the ED 12 days later with complaints of chest pain for 1 day and was found to have a PE within the segmental and subsegmental branches of the left lower lobe.

CONCLUSION

This case suggests that nonhospitalized patients with COVID-19 may be at higher risk for VTE than patients with other medical illnesses and warrants further research into the risk of VTE in outpatients with COVID-19.

Characteristics, laboratories, and prognosis of severe COVID-19 in the Tokyo metropolitan area: A retrospective case series

The impact of the COVID-19 pandemic has been immense, while the epidemiology and pathophysiology remain unclear. Despite many casualties in many countries, there have been less than 1,000 deaths in Japan as of end of June, 2020. In this study, we analyzed the cases of COVID-19 patients admitted to our institution located in the Tokyo metropolitan area where the survival rate is higher than those in other cities in the world. Medical records of COVID-19 patients that were admitted to a single Japanese tertiary university hospital in the Tokyo metropolitan area between March 10th and June 2nd, 2020 were retrospectively reviewed. The identified COVID-19 cases were subdivided into two groups (severe and mild) depending on the need for mechanical ventilation. Those in the severe group required mechanical ventilation as opposed to those in the mild group. The data were analyzed using nonparametric tests expressed by median [interquartile range (IQR)]. A total of 45 COVID-19 patients were included, consisting of 22 severe cases (Group S) and 23 mild cases (Group M). Male sex (Group S, 95.5% vs. Group M, 56.5%, p<0.01), high body mass index (Group S, 24.89 [22.44-27.15] vs. Group M, 21.43 [19.05-23.75], p<0.01), and hyperlipidemia (Group S, 36.4% vs. Group M, 0%, p<0.01) were more seen in Group S. Five (22.7%) cases in Group S underwent extracorporeal membranous oxygenation (ECMO). On admission, lymphopenia, decreased albumin, and elevated fibrinogen, lactate dehydrogenase, transaminases, creatine kinase, C-reactive protein, and procalcitonin were observed in Group S. The median ICU and hospital stay were 13.5 [10.3-22.3] days and 23.0 [16.3-30.5] days, respectively, in Group S. As of June 28th, 2020, in Group S, 19 (86.4%) patients have survived, of which 17 (77.3%) were discharged, and 2 are still in treatments. Three died of multiple organ failure. All 23 patients in Group M have recovered. Male sex, high body mass index, and hyperlipidemia can be risk factors for severe COVID-19 pneumonia, and its overall short-term survival rate was between 77.3% and 86.4% in this study.

The Spectrum of Histopathologic Findings in Lungs of Patients With Fatal Coronavirus Disease 2019 (COVID-19) Infection

Context.—

Respiratory failure appears to be the ultimate mechanism of death in most patients with severe coronavirus disease 2019 (COVID-19) infection. Studies of postmortem COVID-19 lungs largely report diffuse alveolar damage and capillary fibrin thrombi, but we have also observed other patterns.

Objective.—

To report demographic and radiographic features along with macroscopic, microscopic, and microbiologic postmortem lung findings in patients with COVID-19 infections.

Design.—

Patients with confirmed COVID-19 infection and postmortem examination (March 2020–May 2020) were included. Clinical findings were abstracted from medical records. Lungs were microscopically reviewed independently by 4 thoracic pathologists. Imaging studies were reviewed by a thoracic radiologist.

Results.—

Eight patients (7 men, 87.5%; median age, 79 years; range, 69–96 years) died within a median of 17 days (range, 6–100 days) from onset of symptoms. The median lung weight was 1220 g (range, 960–1760 g); consolidations were found in 5 patients (62.5%) and gross thromboemboli were noted in 1 patient (12.5%). Histologically, all patients had acute bronchopneumonia; 6 patients (75%) also had diffuse alveolar damage. Two patients (25%) had aspiration pneumonia in addition. Thromboemboli, usually scattered and rare, were identified in 5 patients (62.5%) in small vessels and in 2 of these patients also in pulmonary arteries. Four patients (50%) had perivascular chronic inflammation. Postmortem bacterial lung cultures were positive in 4 patients (50%). Imaging studies (available in 4 patients) were typical (n = 2, 50%), indeterminate (n = 1, 25%), or negative (n = 1, 25%) for COVID-19 infection.

Conclusions.—

Our study shows that patients infected with COVID-19 not only have diffuse alveolar damage but also commonly have acute bronchopneumonia and aspiration pneumonia. These findings are important for management of these patients.