Is there a role for tissue plasminogen activator as a novel treatment for refractory COVID-19 associated acute respiratory distress syndrome?

All tangled up: interactions of the fibrinolytic and innate immune systems

The hemostatic and innate immune system are intertwined processes. Inflammation within the vasculature promotes thrombus development, whilst fibrin forms part of the innate immune response to trap invading pathogens. The awareness of these interlinked process has resulted in the coining of the terms "thromboinflammation" and "immunothrombosis." Once a thrombus is formed it is up to the fibrinolytic system to resolve these clots and remove them from the vasculature. Immune cells contain an arsenal of fibrinolytic regulators and plasmin, the central fibrinolytic enzyme. The fibrinolytic proteins in turn have diverse roles in immunoregulation. Here, the intricate relationship between the fibrinolytic and innate immune system will be discussed.

Venovenous extracorporeal membrane oxygenation support in patients with COVID-19 respiratory failure: A multicenter study

Objective

The COVID-19 pandemic presents a high mortality rate amongst patients who develop severe acute respiratory distress syndrome (ARDS). The purpose of this study was to evaluate the outcomes of venovenous extracorporeal membrane oxygenation (VV-ECMO) in COVID-19-related ARDS and identify the patients who benefit the most from this procedure.

Methods

Adult patients with COVID-19 and severe ARDS requiring VV-ECMO support at 4 academic institutions between March and October 2020 were included. Data were collected through retrospective chart reviews. Bivariate and multivariable analyses were performed with the primary outcome of in-hospital mortality.

Results

Fifty-one consecutive patients underwent VV-ECMO with a mean age of 50.4 years; 64.7% were men. Survival to hospital discharge was 62.8%. Median intensive care unit and hospitalization duration were 27.4 days (interquartile range [IQR], 17-37 days) and 34.5 days (IQR, 23-43 days), respectively. Survivors and nonsurvivors had a median ECMO cannulation time of 11 days (IQR, 8-18) and 17 days (IQR, 12-25 days). The average postdecannulation length of stay was 17.5 days (IQR, 12.4-25 days) for survivors and 0 days for nonsurvivors (IQR, 0-6 days). Only 1 nonsurvivor was able to be decannulated. Clinical characteristics associated with mortality between nonsurviors and survivors included increasing age (P = .0048), hemorrhagic stroke (P = .0014), and postoperative dialysis (P = .0013) were associated with mortality in a bivariate model and retained statistical significance in a multivariable model.

Conclusions

This multicenter study confirms the effectiveness of VV-ECMO in selected critically ill patients with COVID-19-related severe ARDS. The survival of these patients is comparable to non-COVID-19-related ARDS.

Immuno-Thrombotic Complications of COVID-19: Implications for Timing of Surgery and Anticoagulation

Early in the coronavirus disease 2019 (COVID-19) pandemic, global governing bodies prioritized transmissibility-based precautions and hospital capacity as the foundation for delay of elective procedures. As elective surgical volumes increased, convalescent COVID-19 patients faced increased postoperative morbidity and mortality and clinicians had limited evidence for stratifying individual risk in this population. Clear evidence now demonstrates that those recovering from COVID-19 have increased postoperative morbidity and mortality. These data-in conjunction with the recent American Society of Anesthesiologists guidelines-offer the evidence necessary to expand the early pandemic guidelines and guide the surgeon's preoperative risk assessment. Here, we argue elective surgeries should still be delayed on a personalized basis to maximize postoperative outcomes. We outline a framework for stratifying the individual COVID-19 patient's fitness for surgery based on the symptoms and severity of acute or convalescent COVID-19 illness, coagulopathy assessment, and acuity of the surgical procedure. Although the most common manifestation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is COVID-19 pneumonitis, every system in the body is potentially afflicted by an endotheliitis. This endothelial derangement most often manifests as a hypercoagulable state on admission with associated occult and symptomatic venous and arterial thromboembolisms. The delicate balance between hyper and hypocoagulable states is defined by the local immune-thrombotic crosstalk that results commonly in a hemostatic derangement known as fibrinolytic shutdown. In tandem, the hemostatic derangements that occur during acute COVID-19 infection affect not only the timing of surgical procedures, but also the incidence of postoperative hemostatic complications related to COVID-19-associated coagulopathy (CAC). Traditional methods of thromboprophylaxis and treatment of thromboses after surgery require a tailored approach guided by an understanding of the pathophysiologic underpinnings of the COVID-19 patient. Likewise, a prolonged period of risk for developing hemostatic complications following hospitalization due to COVID-19 has resulted in guidelines from differing societies that recommend varying periods of delay following SARS-CoV-2 infection. In conclusion, we propose the perioperative, personalized assessment of COVID-19 patients' CAC using viscoelastic hemostatic assays and fluorescent microclot analysis.

MUlticenter STudy of tissue plasminogen activator (alteplase) use in COVID‐19 severe respiratory failure (MUST COVID): A retrospective cohort study

Background

Few therapies exist to treat severe COVID‐19 respiratory failure once it develops. Given known diffuse pulmonary microthrombi on autopsy studies of COVID‐19 patients, we hypothesized that tissue plasminogen activator (tPA) may improve pulmonary function in COVID‐19 respiratory failure.

Methods

A multicenter, retrospective, observational study of patients with confirmed COVID‐19 and severe respiratory failure who received systemic tPA (alteplase) was performed. Seventy‐nine adults from seven medical centers were included in the final analysis after institutional review boards' approval; 23 were excluded from analysis because tPA was administered for pulmonary macroembolism or deep venous thrombosis. The primary outcome was improvement in the PaO₂/FiO₂ ratio from baseline to 48 h after tPA. Linear mixed modeling was used for analysis.

Results

tPA was associated with significant PaO₂/FiO₂ improvement at 48 h (estimated paired difference = 23.1 ± 6.7), which was sustained at 72 h (interaction term p < 0.00). tPA administration was also associated with improved National Early Warning Score 2 scores at 24, 48, and 72 h after receiving tPA (interaction term p = 0.00). D‐dimer was significantly elevated immediately after tPA, consistent with lysis of formed clot. Patients with declining respiratory status preceding tPA administration had more marked improvement in PaO₂/FiO₂ ratios than those who had poor but stable (not declining) respiratory status. There was one intracranial hemorrhage, which occurred within 24 h following tPA administration.

Conclusions

These data suggest tPA is associated with significant improvement in pulmonary function in severe COVID‐19 respiratory failure, especially in patients whose pulmonary function is in decline, and has an acceptable safety profile in this patient population.

COVID-19 and thrombotic complications-the role of anticoagulants, antiplatelets and thrombolytics

Coronavirus disease 2019 (COVID-19) is a global pandemic the world is dealing with currently. Clinical evidences suggest that the patients are predisposed to both venous and arterial thrombotic complications. This is because of severe inflammatory responses, injury to endothelium and activation of platelets leading to increased coagulation. Additionally, individuals who are already receiving antithrombotic drug therapy for various cardiovascular diseases and complications might contract the disease in which case, attention should be given to the choice and duration of the therapy besides close monitoring of biochemical blood parameters. Herein, we review the incidences of thrombotic complications and their outcomes in COVID-19 patients as reported till date, while understanding the prophylactic and therapeutic roles of anticoagulants, antiplatelets and thrombolytics in the management of this severe viral respiratory illness.

Acute respiratory distress syndrome in COVID-19: possible mechanisms and therapeutic management

COVID-19 pandemic is a serious concern in the new era. Acute respiratory distress syndrome (ARDS), and lung failure are the main lung diseases in COVID-19 patients. Even though COVID-19 vaccinations are available now, there is still an urgent need to find potential treatments to ease the effects of COVID-19 on already sick patients. Multiple experimental drugs have been approved by the FDA with unknown efficacy and possible adverse effects. Probably the increasing number of studies worldwide examining the potential COVID-19 related therapies will help to identification of effective ARDS treatment. In this review article, we first provide a summary on immunopathology of ARDS next we will give an overview of management of patients with COVID-19 requiring intensive care unit (ICU), while focusing on the current treatment strategies being evaluated in the clinical trials in COVID-19-induced ARDS patients.

Current trends in diagnosis and treatment strategies of COVID-19 infection

Coronaviruses are terrifically precise and adapted towards specialized respiratory epithelial cells, observed in organ culture and human volunteers both. This virus is found to possess an unpredictable anti-viral T-cell response which in turn results in T-cell activation and finally apoptosis, leading to cytokine storm and collapse of the whole immune system. The present review provides comprehensive information regarding SARS-CoV-2 infection, mutant strains, and the impact of SARS-COV-2 on vital organs, the pathophysiology of the disease, diagnostic tests available, and possible treatments. It also includes all the vaccines developed so far throughout the world to control this pandemic. Until now, 18 vaccines have been approved by the WHO and further 22 vaccines are in the third trial. This study also provides up-to-date information regarding the drugs repurposed in clinical trials and the recent status of allopathic drugs along with its result. Although vaccines are available, specific treatment is not available for the disease. Furthermore, the effect of vaccines on new variants is a new area of research at this time. Therefore, a preventive attitude is the best approach to fight against this virus.

Study of Alteplase for Respiratory Failure in SARS-CoV-2 COVID-19: A Vanguard Multicenter, Rapidly Adaptive, Pragmatic, Randomized Controlled Trial

Background

Pulmonary vascular microthrombi are a proposed mechanism of COVID-19 respiratory failure. We hypothesized that early administration of tissue plasminogen activator (tPA) followed by therapeutic heparin would improve pulmonary function in these patients.

Research Question

Does tPA improve pulmonary function in severe COVID-19 respiratory failure, and is it safe?

Study Design and Methods

Adults with COVID-19-induced respiratory failure were randomized from May14, 2020 through March 3, 2021, in two phases. Phase 1 (n = 36) comprised a control group (standard-of-care treatment) vs a tPA bolus (50-mg tPA IV bolus followed by 7 days of heparin; goal activated partial thromboplastin time [aPTT], 60-80 s) group. Phase 2 (n = 14) comprised a control group vs a tPA drip (50-mg tPA IV bolus, followed by tPA drip 2 mg/h plus heparin 500 units/h over 24 h, then heparin to maintain aPTT of 60-80 s for 7 days) group. Patients were excluded from enrollment if they had not undergone a neurologic examination or cross-sectional brain imaging within the previous 4.5 h to rule out stroke and potential for hemorrhagic conversion. The primary outcome was Pao₂ to Fio₂ ratio improvement from baseline at 48 h after randomization. Secondary outcomes included Pao₂ to Fio₂ ratio improvement of > 50% or Pao₂ to Fio₂ ratio of ≥ 200 at 48 h (composite outcome), ventilator-free days (VFD), and mortality.

Results

Fifty patients were randomized: 17 in the control group and 19 in the tPA bolus group in phase 1 and eight in the control group and six in the tPA drip group in phase 2. No severe bleeding events occurred. In the tPA bolus group, the Pao₂ to Fio₂ ratio values were significantly (P < .017) higher than baseline at 6 through 168 h after randomization; the control group showed no significant improvements. Among patients receiving a tPA bolus, the percent change of Pao₂ to Fio₂ ratio at 48 h (16.9% control [interquartile range (IQR), –8.3% to 36.8%] vs 29.8% tPA bolus [IQR, 4.5%-88.7%]; P = .11), the composite outcome (11.8% vs 47.4%; P = .03), VFD (0.0 [IQR, 0.0-9.0] vs 12.0 [IQR, 0.0-19.0]; P = .11), and in-hospital mortality (41.2% vs 21.1%; P = .19) did not reach statistically significant differences when compared with those of control participants. The patients who received a tPA drip did not experience benefit.

Interpretation

The combination of tPA bolus plus heparin is safe in severe COVID-19 respiratory failure. A phase 3 study is warranted given the improvements in oxygenation and promising observations in VFD and mortality.

Trial Registry

ClinicalTrials.gov; No.: NCT04357730; URL: www.clinicaltrials.gov

Viscoelastic testing in benign hematologic disorders: Clinical perspectives and future implications of point-of-care testing to assess hemostatic competence

Viscoelastic tests (VETs) have been used routinely for liver transplantation, cardiac surgery, and trauma, but only recently have found clinical utility in benign hematologic disorders. Therefore, guidelines for diagnosis and treatment of these disorders based on viscoelastic variables have been adapted from the existing transplant, cardiothoracic surgery, and trauma resuscitation literature. As a result, diagnostic and therapeutic strategies for benign hematologic disorders utilizing VETs are not uniform. Accordingly, even though there has been a recent increase in the utilization of VET for the diagnosis and treatment of such disorders, the literature is still in its early stages. Analysis of point-of-care viscoelastic tracings from benign hematologic disorders has the potential to allow prompt recognition of disease and to guide patient-specific intervention. Here we present a review describing the application of VETs to benign hematologic disorders.

Use of Exogenous Enzymes in Human Therapy: Approved Drugs and Potential Applications

The development of safe and efficacious enzyme-based human therapies has increased greatly in the last decades, thanks to remarkable advances in the understanding of the molecular mechanisms responsible for different diseases, and the characterization of the catalytic activity of relevant exogenous enzymes that may play a remedial effect in the treatment of such pathologies. Several enzyme-based biotherapeutics have been approved by FDA (the U.S. Food and Drug Administration) and EMA (the European Medicines Agency) and many are undergoing clinical trials. Apart from enzyme replacement therapy in human genetic diseases, which is not discussed in this review, approved enzymes for human therapy find applications in several fields, from cancer therapy to thrombolysis and the treatment, e.g., of clotting disorders, cystic fibrosis, lactose intolerance and collagen-based disorders. The majority of therapeutic enzymes are of microbial origin, the most convenient source due to fast, simple and cost-effective production and manipulation. The use of microbial recombinant enzymes has broadened prospects for human therapy but some hurdles such as high immunogenicity, protein instability, short half-life and low substrate affinity, still need to be tackled. Alternative sources of enzymes, with reduced side effects and improved activity, as well as genetic modification of the enzymes and novel delivery systems are constantly searched. Chemical modification strategies, targeted- and/or nanocarrier-mediated delivery, directed evolution and site-specific mutagenesis, fusion proteins generated by genetic manipulation are the most explored tools to reduce toxicity and improve bioavailability and cellular targeting. This review provides a description of exogenous enzymes that are presently employed for the therapeutic management of human diseases with their current FDA/EMA-approved status, along with those already experimented at the clinical level and potential promising candidates.

Use of Antioxidants for the Neuro-Therapeutic Management of COVID-19

Coronavirus Disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), is an emergent infectious disease that has caused millions of deaths throughout the world. COVID-19 infection's main symptoms are fever, cough, fatigue, and neurological manifestations such as headache, myalgias, anosmia, ageusia, impaired consciousness, seizures, and even neuromuscular junctions' disorders. In addition, it is known that this disease causes a series of systemic complications such as adverse respiratory distress syndrome, cardiac injury, acute kidney injury, and liver dysfunction. Due to the neurological symptoms associated with COVID-19, damage in the central nervous system has been suggested as well as the neuroinvasive potential of SARS-CoV-2. It is known that CoV infections are associated with an inflammation process related to the imbalance of the antioxidant system; cellular changes caused by oxidative stress contribute to brain tissue damage. Although anti-COVID-19 vaccines are under development, there is no specific treatment for COVID-19 and its clinical manifestations and complications; only supportive treatments with immunomodulators, anti-vascular endothelial growth factors, modulating drugs, statins, or nutritional supplements have been used. In the present work, we analyzed the potential of antioxidants as adjuvants for the treatment of COVID-19 and specifically their possible role in preventing or decreasing the neurological manifestations and neurological complications present in the disease.

Repurposing metformin for covid-19 complications in patients with type 2 diabetes and insulin resistance

Understanding the exact role of current drugs in Covid-19 disease is essential in the era of global pandemics. Metformin which prescribed as the first-line treatment of type 2 diabetes has beneficial effects on Sars-cov2 infection. These effects are including regulation of immune system, Renin-Angiotensin System and Dipeptidyl Peptidase 4 function in Covid-19 infection. It also activates ACE2, the main receptor of Sars-cov2, in the epithelial cells of respiratory tissue through AMPK signaling and subsequently decreases the rate of viral adhesion. Metformin also declines the adherence of Sars-cov2 to DPP4 (the other receptor of the virus) on T cells. Hence, regulatory effects of metformin on membranous ACE2, and DPP4 can modulate immune reaction against Sars-cov2. Also, immunometabolic effects of metformin on inflammatory cells impair hyper-reactive immune response against the virus through reduction of glycolysis and propagation of mitochondrial oxidation. Metformin also decreases platelet aggravation and risk of thrombosis. In this article, we argue that metformin has beneficial effects on Covid-19 infection in patients with type 2 diabetes and insulin resistance. This opinion should be investigated in future clinical trials.

Can Yogic Breathing Techniques Like Simha Kriya and Isha Kriya Regulate COVID-19-Related Stress?

The global impact of Coronavirus Disease 2019 (COVID-19) is tremendous on human life, not only affecting the physical and mental health of population but also impacting the economic system of countries and individual itself. The present situation demands prompt response toward COVID-19 by equipping the humans with strategies to overcome the infection and stress associated with it. These strategies must not only be limited to preventive and therapeutic measures, but also aim at improving immunity and mental health. This can be achieved by yogic breathing techniques. In this perspective, we emphasize the importance of yogic breathing, Simha Kriya and Isha kriya, the simple yet effective breathing techniques.

Rhabdomyolysis in Severe COVID-19: Male Sex, High Body Mass Index, and Prone Positioning Confer High Risk

BACKGROUND

Bedside experience and studies of critically ill patients with coronavirus disease 2019 (COVID-19) indicate COVID-19 to be a devastating multisystem disease. We aim to describe the incidence, associated variables, and outcomes of rhabdomyolysis in critically ill COVID-19 patients.

MATERIALS AND METHODS

Data for all critically ill adult patients (≥18 years old) admitted to the ICU at a large academic medical center with confirmed COVID-19 between March 13, 2020 and April 18, 2020 were prospectively collected. Patients with serum creatine kinase (CK) concentrations greater than 1000 U/L were diagnosed with rhabdomyolysis. Patients were further stratified as having moderate (serum CK concentration 1000-4999 U/L) or severe (serum CK concentration ≥5000 U/L) rhabdomyolysis. Univariate and multivariate analyses were performed to identify outcomes and variables associated with the development of rhabdomyolysis.

RESULTS

Of 235 critically ill COVID-19 patients, 114 (48.5%) met diagnostic criteria for rhabdomyolysis. Patients with rhabdomyolysis more often required mechanical ventilation (P < 0.001), prone positioning (P < 0.001), pharmacological paralysis (P < 0.001), renal replacement therapy (P = 0.010), and extracorporeal membrane oxygenation (ECMO) (P = 0.025). They also had longer median ICU length of stay (LOS) (P < 0.001) and hospital LOS (P < 0.001). No difference in mortality was observed. Male sex, patients with morbid obesity, SOFA score, and prone positioning were independently associated with rhabdomyolysis.

CONCLUSIONS

Nearly half of critically ill COVID-19 patients in our cohort met diagnostic criteria for rhabdomyolysis. Male sex, morbid obesity, SOFA score, and prone position were independently associated with rhabdomyolysis.

Impact of a clinical pharmacist on ultrasound-guided venous thromboembolism screening in hospitalized COVID-19 patients: a pilot prospective study

Background

The recognition, prevention and treatment of venous thromboembolism (VTE) remains a major challenge in the face of the recent COVID-19 pandemic which has been associated with significant cardiovascular, renal, respiratory and hematologic complications related to hypercoagulability. There has been little literature thus far on the utility of screening ultrasound and the role of the clinical pharmacist in treating these patients.

Methods

We present a prospective pilot program of thirty-one consecutive COVID-19 patients who were provided four extremity screening ultrasounds for VTE on admission. This was coordinated by a clinical pharmacist as part of a multidisciplinary approach. Quantitative and qualitative data were recorded with the goal of describing the utility of the clinical pharmacist in ultrasound screening. Data collected include demographics, information on clinical symptoms or signs at presentation, and laboratory and radiologic results during the hospitalization from each individual electronic medical record.

Results

Nine of the thirty-one patients presented with VTE. Of the nine patients, there were twenty-two total clotted vessels, all of which were asymptomatic. The clinical pharmacist, as the coordinator for a multidisciplinary COVID-19 associated coagulopathy management team, drafted a screening and treatment protocol for anticoagulation prophylaxis and therapy of VTE after ultrasound findings.

Conclusion

VTE screening of hospitalized COVID-19 patients reveals a significant number of asymptomatic VTEs and justifies diagnostic, prophylactic, and treatment measures coordinated by a clinical pharmacist.

Fibrinolysis Shutdown in COVID-19: Clinical Manifestations, Molecular Mechanisms, and Therapeutic Implications

The COVID-19 pandemic has introduced a global public health threat unparalleled in our history. The most severe cases are marked by ARDS attributed to microvascular thrombosis. Hypercoagulability, resulting in a profoundly prothrombotic state, is a distinct feature of COVID-19 and is accentuated by a high incidence of fibrinolysis shutdown. The aims of this review were to describe the manifestations of fibrinolysis shutdown in COVID-19 and its associated outcomes, review the molecular mechanisms of dysregulated fibrinolysis associated with COVID-19, and discuss potential implications and therapeutic targets for patients with severe COVID-19.

Potential therapeutic and pharmacological strategies for SARS-CoV2

BACKGROUND

At the end of 2019, the new Coronavirus disease 2019 (COVID-19) strain causing severe acute respiratory syndrome swept the world. From November 2019 till February 2021, this virus infected nearly 104 million, with more than two million deaths and about 25 million active cases. This has prompted scientists to discover effective drugs to combat this pandemic.

AREA COVERED

Drug repurposing is the magic bullet for treating severe acute respiratory syndrome coronavirus 2 (SARS-CoV2). Therefore, several drugs have been investigated in silico, in vitro, as well as through human trials such as anti-SARS-CoV2 agents, or to prevent the complications resulting from the virus. In this review, the mechanisms of action of different therapeutic strategies are summarized. According to the WHO, different classes of drugs can be used, including anti-malarial, antiviral, anti-inflammatory, and anti-coagulant drugs, as well as angiotensin-converting enzyme inhibitors, antibiotics, vitamins, zinc, neutralizing antibodies, and convalescent plasma therapy. Recently, there are some vaccines which are approved against SARS-CoV2.

EXPERT OPINION

A complete understanding of the structure and function of all viral proteins that play a fundamental role in viral infection, which contribute to the therapeutic intervention and the development of vaccine in order to reduce the mortality rate.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40005-021-00520-4.

Coagulopathy in COVID-19

Hemostatic derangement is a hallmark in severe COVID-19. Markedly elevation of D-dimer and fibrinogen degradation product levels were observed in patients with severe COVID-19 higher and 71.4% of nonsurvivors met the International Society of Thrombosis and Haemostasis criteria of disseminated intravascular coagulation (DIC). Although the clinical and epidemiological features of COVID-19 have been well-described, the underlying mechanism influencing disease severity remains to be elucidated. Herein, the aim of this review article is to evaluate hemostasis in the pathogenesis of COVID-19 and its role in the management of this unprecedented pandemic.

Fibrinolysis Shutdown and Thrombosis in a COVID-19 ICU

ABSTRACT

The coronavirus disease (COVID-19) pandemic has threatened millions of lives worldwide with severe systemic inflammation, organ dysfunction, and thromboembolic disease. Within our institution, many critically ill COVID-19-positive patients suffered major thrombotic events, prompting our clinicians to evaluate hypercoagulability outside of traditional coagulation testing.We determined the prevalence of fibrinolysis shutdown via rotational thromboelastometry (ROTEM, Instrumentation Laboratories, Bedford, Mass) in patients admitted to the intensive care unit over a period of 3 weeks. In 25 patients who had a ROTEM test, we found that 11 (44%) met criteria for fibrinolysis shutdown. Eight of 9 (73%) of the VTE patients met criteria for fibrinolysis shutdown.Given the high rate of fibrinolysis shutdown in these patients, our data support using viscoelastic testing to evaluate for the presence of impaired fibrinolysis. This may help identify patient subsets who might benefit from the administration of fibrinolytics.

Neutrophil Extracellular Traps in Coronavirus Disease-19-Associated Ischemic Stroke: A Novel Avenue in Neuroscience

Ischemic stroke is one of the catastrophic neurological events that are being increasingly recognized among Coronavirus Disease (COVID)-19 patients. The recent studies have revealed about a possible connection among COVID-19, ischemic stroke, and excessive Neutrophil Extracellular Traps (NETs) formation. This paper establishes an overview of coronaviruses and NETs, NETs in pathogenesis of COVID-19 induced-ischemic stroke, and future directions using related recent literatures. NETs are normally functioned for a defense against pathogens, but in immoderate amount, they can trigger series of destructive events. Vasculopathy and neuroinflammation are the pathological mechanisms of NETs suggested to link COVID-19 and ischemic stroke. Based on newly discovered possible mechanisms, the potential clinical implications that could be applied consists of inhibition of NET formation, disrupting cholesterol synthesis, and interfering inflammatory pathway. A considerable number of scientific works are needed in order to complete the current understanding of the emerging relationship among COVID-19, NETs, and ischemic stroke. Although the exact mechanism is still unknown, these novel findings are a worthwhile contribution in defining future studies, suitable future frameworks, and therapeutic strategies.

Monitoring of COVID-19-Associated Coagulopathy and Anticoagulation with Thromboelastometry

Introduction

Thrombosis occurs frequently in COVID-19. While the exact mechanism is unclear, 3 processes seem to play important roles in sepsis-related thrombosis and mortality: tissue factor expression on circulating monocytes and microparticles, hypercoagulability (increased clot firmness), and hypofibrinolysis. Rotational thromboelastometry is a point-of-care viscoelastic technique that uses the viscoelastic properties of blood to monitor coagulation. Using various assays, viscoelastometry could monitor this triad of changes in severely ill, COVID-19-positive patients. Similarly, with the increased incidence of coagulopathy, many patients are placed on anticoagulants, making management more difficult depending on the agents utilized. Viscoelastometry might also be used in these settings to monitor anticoagulation status and guide therapy, as it has in other areas.

Case Presentation

We present a case series of 6 patients with different stages of disease and different management plans. These cases occurred at the height of the pandemic in New York City, which limited testing abilities. We first discuss the idea of using the NaHEPTEM test as a marker of tissue factor expression in COVID-19. We then present cases where patients are on different anticoagulants and review how viscoelastometry might be used in a patient on anticoagulation with COVID-19.

Conclusion

In a disease such as COVID-19, which has profound effects on hemostasis and coagulation, viscoelastometry may aid in patient triage, disease course monitoring, and anticoagulation management.

COVID-19 and Its Implications for Thrombosis and Anticoagulation

Venous thromboembolism, occlusion of dialysis catheters, circuit thrombosis in extracorporeal membrane oxygenation (ECMO) devices, acute limb ischemia, and isolated strokes, all in the face of prophylactic and even therapeutic anticoagulation, are features of novel coronavirus disease 2019 (COVID-19) coagulopathy. It seems well established at this time that a COVID-19 patient deemed sick enough to be hospitalized, should receive at least prophylactic dose anticoagulation. However, should some hospitalized patients have dosage escalation to intermediate dose? Should some be considered for full-dose anticoagulation without a measurable thromboembolic event and how should that anticoagulation be monitored? Should patients receive postdischarge anticoagulation and with what medication and for how long? What thrombotic issues are related to the various medications being used to treat this coagulopathy? Is antiphospholipid antibody part of this syndrome? What is the significance of isolated ischemic stroke and limb ischemia in this disorder and how does this interface with the rest of the clinical and laboratory features of this disorder? The aims of this article are to explore these questions and interpret the available data based on the current evidence.

Management and Prevention of Cerebrovascular Accidents in SARS-CoV-2-Positive Patients Recovering from COVID-19: a Case Report and Review of Literature

We discuss the current understanding of COVID-19’s neurological implications, their basis, and the evolving clinical consensus with a focus on cerebrovascular stroke. We further illustrate the potential significance of these implications with the aid of an accompanying case report outlining the disease course and treatment of a COVID-19 patient suffering from ischemic stroke and pulmonary embolism. The ever-growing strain on the global healthcare system due to the spread of the novel coronavirus SARS-CoV-2 requires focused attention on urgent care of independent, coexisting, and associated comorbidities, including cerebrovascular accidents. For illustration purposes, we outline the case of a 68-year-old female presenting with COVID-19 subsequently complicated by bilateral pulmonary embolism and a right-sided cerebrovascular accident. The patient was successfully managed pharmacologically and discharged without significant neurological deficit. The evidence for a hypercoagulable state in this patient along with discussion of mechanistic bases, corroborative evidence from the literature, along with relevant guidance on screening, treatment, and prophylaxis is offered. Greater study of the pathogenesis of COVID-19-related cerebrovascular complications and revisiting current guidelines on their management including potentially heightened levels of thromboprophylaxis are warranted.

Recombinant tissue plasminogen activator treatment for COVID-19 associated ARDS and acute cor pulmonale

Existing literature highlights the fact that patients with COVID-19 exhibit alterations in the coagulation process and are associated with respiratory and cardiovascular diseases, including acute respiratory distress syndrome and acute cor pulmonale. In this report, we describe the effects of systemic thrombolysis on acute cor pulmonale in a patient suffering from COVID-19. We demonstrated that systemic thrombolysis successfully improved the hemodynamics of our patient and resulted in a prominent reduction in hypercapnia, alveolar dead space, and ventilatory ratio.

Thrombosis and Haemostasis challenges in COVID-19 - Therapeutic perspectives of heparin and tissue-type plasminogen activator and potential toxicological reactions-a mini review

The coronavirus disease (COVID)-19 pandemic is a major challenge for the health systems worldwide. Acute respiratory distress syndrome (ARDS), is one of the most common complications of the COVID-19 infection. The activation of the coagulation system plays an important role in the pathogenesis of ARDS. The development of lung coagulopathy involves thrombin generation and fibrinolysis inhibition.

Unfractionated heparin and its recently introduced counterpart low molecular weight heparin (LMWH), are widely used anticoagulants with a variety of clinical indications allowing for limited and manageable physio-toxicologic side effects while the use of protamine sulfate, heparin's effective antidote, has made their use even safer. Tissue-type plasminogen activator (tPA) is approved as intravenous thrombolytic treatment. The present narrative review discusses the use of heparin and tPA in the treatment of COVID-19-induced ARDS and their related potential physio-toxicologic side effects. The article is a quick review of articles on anticoagulation in COVID infection and the potential toxicologic reactions associated with these drugs.

Neurological and Neuropsychological Changes Associated with SARS-CoV-2 Infection: New Observations, New Mechanisms

SARS-CoV-2 infects cells through angiotensin-converting enzyme 2 (ACE2), a ubiquitous receptor that interacts with the virus' surface S glycoprotein. Recent reports show that the virus affects the central nervous system (CNS) with symptoms and complications that include dizziness, altered consciousness, encephalitis, and even stroke. These can immerge as indirect immune effects due to increased cytokine production or via direct viral entry into brain tissue. The latter is possible through neuronal access via the olfactory bulb, hematogenous access through immune cells or directly across the blood-brain barrier (BBB), and through the brain's circumventricular organs characterized by their extensive and highly permeable capillaries. Last, the COVID-19 pandemic increases stress, depression, and anxiety within infected individuals, those in isolation, and high-risk populations like children, the elderly, and health workers. This review surveys the recent updates of CNS manifestations post SARS-CoV-2 infection along with possible mechanisms that lead to them.

[Pathogenesis, diagnosis, prevention and treatment of disseminated intravascular coagulation syndrome in COVID-19 infection]

AIM

Clinical characteristics of disseminated intravascular coagulation (DIC) in COVID-19 infection and assessment of the effectiveness of complex therapy for this syndrome at the stages of prevention and treatment of various complications.

MATERIALS AND METHODS

The study of publications was carried out through search engines on the Internet using keywords. To diagnose the infection, the COVID-19 program was used on the MeDiCase platform, which is publicly available on www.medicase.pro, which suggests a diagnosis with a sensitivity of 89.47%. The study included 85 patients with acute COVID-19 with mild to moderate disease, aged 11 to 81 years. The presence of the pathogen was confirmed immunologically in 12% of patients; in other cases, the diagnosis was based on the results of an automated survey in the MeDiCase system. All patients, according to the MGNOT recommendations, were prescribed one of the oral direct anticoagulants - Eliquis at a dose of 5 mg 2 times a day, Ksarelto at a dose of 10 mg 2 times a day or Pradax at a dose of 110 mg 2 times a day for at least 2 weeks. All other drugs with antiviral, immunomodulatory effects, antibiotics were canceled.

RESULTS

The presence of DIC is substantiated by the morphological picture of changes in organs and tissues, clinical (hematoma-petechial type of bleeding in combination with thromboembolic syndrome and the presence of thrombovasculitis) and laboratory changes: an increase in the level of soluble fibrin-monomer complexes, D-dimer, hyperfibrinogenaemia, less often - thrombocytopenia, violation of fibrinolytic activity. The phenomenon of consumption of clotting factors and profuse bleeding are rare. Direct anticoagulants, fresh frozen plasma transfusions and plasmapheresis are used in the treatment of disseminated intravascular coagulation. The paper presents its own positive results of early prescription at the outpatient stage of direct oral anticoagulants in prophylactic doses (no case of disease progression), individual cases of the use of fresh frozen plasma and plasapheresis.

CONCLUSION

DIC syndrome with the development of thrombovasculitis is the most important pathogenetic mechanism for the development of microthrombotic and hemorrhagic disorders in organs during infection with COVID-19, leading to dysfunction of the lungs, brain and other nerve tissues, kidneys, thromboembolic complications, etc. Many symptoms of the disease may be associated with a violation of the nervous regulation of the functions of organs and systems. Prevention of thrombovasculitis is effective already at the stage of the first manifestation of the disease with the outpatient use of direct anticoagulants (oral, low molecular weight heparins). In case of more severe manifestations (complications) of the disease, additional use of freshly frozen plasma and plasmapheresis is effective.

Endothelial activation and dysfunction in COVID-19: from basic mechanisms to potential therapeutic approaches

On 12 March 2020, the outbreak of coronavirus disease 2019 (COVID-19) was declared a pandemic by the World Health Organization. As of 4 August 2020, more than 18 million confirmed infections had been reported globally. Most patients have mild symptoms, but some patients develop respiratory failure which is the leading cause of death among COVID-19 patients. Endothelial cells with high levels of angiotensin-converting enzyme 2 expression are major participants and regulators of inflammatory reactions and coagulation. Accumulating evidence suggests that endothelial activation and dysfunction participate in COVID-19 pathogenesis by altering the integrity of vessel barrier, promoting pro-coagulative state, inducing endothelial inflammation, and even mediating leukocyte infiltration. This review describes the proposed cellular and molecular mechanisms of endothelial activation and dysfunction during COVID-19 emphasizing the principal mediators and therapeutic implications.

A Systematic Review of the Cardiovascular Manifestations and Outcomes in the Setting of Coronavirus-19 Disease

The impact of coronavirus disease, 2019 (COVID-19), has been profound. Though COVID-19 primarily affects the respiratory system, it has also been associated with a wide range of cardiovascular (CV) manifestations portending extremely poor prognosis. The principal hypothesis for CV involvement is through direct myocardial infection and systemic inflammation. We conducted a systematic review of the current literature to provide a foundation for understanding the CV manifestations and outcomes of COVID-19. PubMed and EMBASE databases were electronically searched from the inception of the databases through 27 April 2020. A second literature review was conducted to include major trials and guidelines that were published after the initial search but before submission. The inclusion criteria for studies to be eligible were case reports, case series, and observation studies reporting CV outcomes among patients with COVID-19 infection. This review of the current COVID-19 disease and CV outcomes literature revealed a myriad of CV manifestations with potential avenues for treatment and prevention. Future studies are required to understand on a more mechanistic level the effect of COVID-19 on the myocardium and thus provide avenues to improve mortality and morbidity.

Possible Role of Adenosine in COVID-19 Pathogenesis and Therapeutic Opportunities

The outbreak of the novel coronavirus disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome CoronaVirus-2 (SARS-CoV-2) requires urgent clinical interventions. Crucial clinical needs are: 1) prevention of infection and spread of the virus within lung epithelia and between people, 2) attenuation of excessive lung injury in Advanced Respiratory Distress Syndrome, which develops during the end stage of the disease, and 3) prevention of thrombosis associated with SARS-CoV-2 infection. Adenosine and the key adenosine regulators adenosine deaminase (ADA), adenosine kinase (ADK), and equilibrative nucleoside transporter 1 may play a role in COVID-19 pathogenesis. Here, we highlight 1) the non-enzymatic role of ADA by which it might out-compete the virus (SARS-CoV-2) for binding to the CD26 receptor, 2) the enzymatic roles of ADK and ADA to increase adenosine levels and ameliorate Advanced Respiratory Distress Syndrome, and 3) inhibition of adenosine transporters to reduce platelet activation, thrombosis and improve COVID-19 outcomes. Depending on the stage of exposure to and infection by SARS-CoV-2, enhancing adenosine levels by targeting key adenosine regulators such as ADA, ADK and equilibrative nucleoside transporter 1 might find therapeutic use against COVID-19 and warrants further investigation.

An Experimental Model for Peri-conceptual COVID-19 Pregnancy Loss and Proposed Interventions to Optimize Outcomes

Reports appear to give reassurance that vertical transmission near term is unlikely, but risks of incidental SARS-CoV-2 infection during fertility treatments, at embryo implantation, or in the first trimester remain unknown. If early pregnancy sequela in the current COVID-19 pandemic are modeled from the 2004 Coronavirus outbreak data, then SARS-CoV-2 infection proximate to blastocyst nidation is likely to cause implantation failure or spontaneous abortion. Our model explains why this outcome is less attributable to virus-associated maternal pulmonary distress and instead derives from systemic inflammation and interference with trophectoderm-endometrium molecular signaling required for implantation. COVID-19 is often accompanied by high levels of IL-6, IL-8, TNF-alpha and other cytokines, a process implicated in pulmonary collapse and systemic organ failure. Yet when regarded in an early reproductive context, this "cytokine storm" of COVID-19 triggers a pro-coagulative state hostile to normal in utero blastocyst/fetal development. Evidence from obstetrics is accumulating to show that mothers with SARS-CoV-2 deliver placentas with abnormal interstitial villi fibrin deposits, diffuse infarcts, and hemangiomatous changes. This model classifies such lesions as permissive at term but catastrophic near embryo implantation or early first trimester pregnancy. Clinical experience with recurrent pregnancy loss offers workable interventions to address this challenge, but success will depend on prompt and accurate SARS-CoV-2 diagnosis. Although no professional guidelines currently exist for SARS-CoV-2 in early pregnancy, this model would warrant a high-risk designation for such cases; these patients should receive priority access to screening and treatment resources.

The Potential Role of Coagulation Factor Xa in the Pathophysiology of COVID-19: A Role for Anticoagulants as Multimodal Therapeutic Agents

SARS-CoV-2 infection (COVID-19) results in local and systemic activation of inflammation and coagulation. In this review article, we will discuss the potential role of coagulation factor Xa (FXa) in the pathophysiology of COVID-19. FXa, a serine protease, has been shown to play a role in the cleavage of SARS-CoV-1 spike protein (SP), with the inhibition of FXa resulting in the inhibition of viral infectivity. FX is known to be primarily produced in the liver, but it is also expressed by multiple cells types, including alveolar epithelium, cardiac myocytes, and macrophages. Considering that patients with preexisting conditions, including cardiopulmonary disease, are at an increased risk of severe COVID-19, we discuss the potential role of increased levels of FX in these patients, resulting in a potential increased propensity to have a higher infectious rate and viral load, increased activation of coagulation and inflammation, and development of fibrosis. With these observations in mind, we postulate as to the potential therapeutic role of FXa inhibitors as a prophylactic and therapeutic treatment for high-risk patients with COVID-19.

Anticoagulation outcomes in hospitalized Covid-19 patients: A systematic review and meta-analysis of case-control and cohort studies

Background: Coagulopathy and thromboembolic events are common in Covid‐19 patients and are poor prognostic factors. Controversy exists regarding the potential of anticoagulation (AC) to reduce mortality and incidence of thromboembolic events in Covid‐19 patients. The current systematic review and meta‐analysis investigated the association between anticoagulants and mortality in adult hospitalized COVID‐19 patients using the available published non‐randomized studies. Methods: Google Scholar, PubMed, Scopus, the Cochrane Library and Clinical Trials.gov were searched for relevant studies. A meta‐analysis of adjusted and unadjusted estimates was performed. The relative risk was used as a measure of effect. The random‐effects model was used to pool estimates using the generic inverse variance method. Results: Sixteen studies were included in the quantitative data synthesis. Results showed a statistically significant association between AC and mortality (RR = 0.56, 95% CI 0.36; 0.92, p = 0.02). Both therapeutic (Relative risk [RR] = 0.4, 95% CI 0.27; 0.57) and prophylactic AC (RR = 0.54, 95% CI 0.41; 0.71) were associated with lower risk of mortality. Pre‐admission AC was not associated with mortality (RR = 0.84, 95% CI 0.49; 1.43, p > 0.05) while prophylactic AC was associated with higher risk of mortality compared to therapeutic AC (RR = 1.58, 95% CI 1.34; 1.87, p < 0.001). Conclusion: Findings support the association of AC with mortality in Covid‐19 patients. The results, synthesized from mostly low‐quality studies, show that prophylactic and therapeutic AC might reduce mortality in Covid‐19 patients. Findings suggest that therapeutic doses might be associated with better survival compared to prophylactic doses.

Stroke and Novel Coronavirus Infection in Humans: A Systematic Review and Meta-Analysis

Background: As the world witnessed the devastation caused by the coronavirus disease 2019 (COVID-19) outbreak, a growing body of literature on COVID-19 is also becoming increasingly available. Stroke has increasingly been reported as a complication of COVID-19 infection. However, a systematic synthesis of the available data has not been conducted. Therefore, we performed a systematic review and meta-analysis of currently available epidemiological, clinical, and laboratory data related to both stroke and COVID-19 infection.

Methods: We systematically searched Medline, Cinahl, and PubMed for studies related to stroke and COVID-19 from inception up to June 4, 2020. We selected cohort studies, case series, and case reports that reported the occurrence of stroke in COVID-19 patients. A fixed-effects model was used to estimate the pooled frequency of stroke in COVID-19 patients with a 95% confidence interval (CI).

Results: Twenty-eight studies were included in the systematic review and seven studies for the meta-analysis. The pooled frequency of stroke in COVID-19 patients was 1.1% (95% CI: 0.8, 1.3). The heterogeneity was low (I² = 0.0%). Even though the frequency of stroke among patients having COVID-19 infection was low, those with concomitant COVID-19 infection and stroke suffered from a more severe infection and eventually had a poorer prognosis with a higher mortality rate (46.7%) than COVID-19 alone. Many COVID-19 patients shared the common traditional risk factors for stroke. We noted that ischemic stroke involving the anterior circulation with large vessels occlusion is the most common type of stroke with more strokes seen in multi-territorial regions, suggesting systemic thromboembolism. An elevated level of D-dimers, C-reactive protein, ferritin, lactic acid dehydrogenase, troponin, ESR, fibrinogen, and a positive antiphospholipid antibody were also noted in this review.

Conclusions: The occurrence of stroke in patients with COVID-19 infection is uncommon, but it may pose as an important prognostic marker and indicator of severity of infection, by causing large vessels occlusion and exhibiting a thrombo-inflammatory vascular picture. Physicians should be made aware and remain vigilant on the possible two-way relationship between stroke and COVID-19 infection. The rate of stroke among patients with COVID-19 infection may increase in the future as they share the common risk factors.

Observational study of the use of recombinant tissue-type plasminogen activator in COVID-19 shows a decrease in physiological dead space

In December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged as the causative agent for coronavirus disease 2019 (COVID-19), a clinical syndrome with high incidence of acute respiratory distress syndrome (ARDS). Part of the pathophysiology of COVID-19-induced ARDS is explained by increased dead space ventilation from pulmonary microthrombi; this is supported by the existence of alveolar capillary microthrombi found on autopsies [1, 2]. This has prompted the use of therapeutic anticoagulation and thrombolytics [3–5]. Thus far, no clinical trials have been completed to evaluate the use of recombinant tissue-type plasminogen activator (rt-PA) to treat COVID-19. The objective of this study was to determine whether rt-PA administration decreases dead space ventilation in patients with COVID-19.

#COVID19-induced ARDS is partly explained by the presence of microthrombi, motivating the use of thrombolytics. This study shows that thrombolytics decrease dead space ventilation in COVID-19 ARDS patients.https://bit.ly/2GdM44a

The hypercoagulable state in COVID-19: Incidence, pathophysiology, and management

The 2019 coronavirus disease (COVID-19) presents with a large variety of clinical manifestations ranging from asymptomatic carrier state to severe respiratory distress, multiple organ dysfunction and death. While it was initially considered primarily a respiratory illness, rapidly accumulating data suggests that COVID-19 results in a unique, profoundly prothrombotic milieu leading to both arterial and venous thrombosis. Consistently, elevated D-dimer level has emerged as an independent risk factor for poor outcomes, including death. Several other laboratory markers and blood counts have also been associated with poor prognosis, possibly due to their connection to thrombosis. At present, the pathophysiology underlying the hypercoagulable state is poorly understood. However, a growing body of data suggests that the initial events occur in the lung. A severe inflammatory response, originating in the alveoli, triggers a dysfunctional cascade of inflammatory thrombosis in the pulmonary vasculature, leading to a state of local coagulopathy. This is followed, in patients with more severe disease, by a generalized hypercoagulable state that results in macro- and microvascular thrombosis. Of concern, is the observation that anticoagulation may be inadequate in many circumstances, highlighting the need for alternative or additional therapies. Numerous ongoing studies investigating the pathophysiology of the COVID-19 associated coagulopathy may provide mechanistic insights that can direct appropriate interventional strategies.

Increased Dead Space Ventilation and Refractory Hypercapnia in Patients With Coronavirus Disease 2019: A Potential Marker of Thrombosis in the Pulmonary Vasculature

Supplemental Digital Content is available in the text.

Objectives:

Mortality rates in intubated coronavirus disease 2019 patients remain markedly elevated. Some patients develop sudden refractory hypercapnia and hypoxemia not explained by worsening pulmonary parenchymal disease. This case series highlights clinical findings and management of coronavirus disease 2019 patients with refractory hypercapnia despite maximal/optimal ventilatory support. Hypercapnia could not be explained by worsening lung disease or other common factors, and thus, a pulmonary vascular etiology was suggested. The pillars of management were targeted to improve pulmonary vascular patency via aggressive anticoagulation and support right ventricular function.

Data Sources:

Four consecutive patients with confirmed coronavirus disease 2019 infection with sudden hypercapnia and hypoxemia were included.

Data Synthesis:

There was sequential development of: 1) severe hypercapnia attributable to marked elevation of dead space without radiographic changes; 2) concomitant coagulopathy manifest by an increase in d-dimer levels; 3) progressive shunt with consequent hypoxemia; and 4) right ventricular dysfunction. Management included extracorporeal Co₂ removal, direct thrombin inhibition, pulmonary vasodilators, and inotropic support. Marked improvement in Pao₂ allowed reduction in Fio₂ in all patients, extracorporeal Co₂ removal was discontinued in three patients over the ensuing 3 weeks, and one patient was discharged home.

Conclusions:

We speculate that thromboinflammation with pulmonary microvasculature occlusion leads to a sudden increase in dead space and shunt resulting in severe hypercapnia and hypoxemia in coronavirus disease 2019 patients. Early identification of these physiologic and clinical biomarkers could trigger the institution of therapies aiming to reverse the hypercoagulable state and support right ventricular function.

Antithrombotic Therapies in COVID-19 Disease: a Systematic Review

BACKGROUND

Infection with coronavirus SARS-CoV-2, causing COVID-19 disease, leads to inflammation and a prothrombotic state.

OBJECTIVE

This rapid systematic review aims to synthesize evidence on thromboembolism incidence and outcomes with antithrombotic therapies in COVID-19.

DATA SOURCES

We searched MEDLINE (Ovid), Cochrane Rapid Reviews, PROSPERO, and the WHO COVID-19 Database from January 1, 2003, to April 22, 2020, for studies meeting pre-specified inclusion criteria.

STUDY SELECTION, DATA EXTRACTION, AND SYNTHESIS

One investigator identified articles for inclusion, abstracted data, and performed quality assessment, with second reviewer checking.

RESULTS

Incidence of thromboembolism among hospitalized patients with COVID-19 ranged from 25 to 53% in 4 retrospective series. We identified 3 studies (1 retrospective cohort study, 1 prospective uncontrolled observational study, and 1 case series) examining outcomes among COVID-19 patients who received antithrombotic therapies. These studies all included different interventions (thromboprophylaxis with unfractionated heparin (UFH) or low molecular-weight heparin (LMWH); an intensive thromboprophylaxis protocol with LMWH, antithrombin, and clopidogrel; and salvage therapy with tissue plasminogen activator and heparin). These studies are overall poor quality due to methodological limitations including unclear patient selection protocols, lack of reporting or adjustment for patient baseline characteristics, inadequate duration of follow-up, and partial reporting of outcomes.

CONCLUSIONS

New evidence on thromboembolism in COVID-19 does not warrant a change in current guidance on thromboprophylaxis among hospitalized patients. Prospective trials of antithrombotic treatment strategies among patients with COVID-19 are urgently needed.

SARS-CoV-2 and cancer: Are they really partners in crime?

The outbreak of the SARS-CoV-2 pandemic has overwhelmed health care systems in many countries. The clinical presentation of the SARS-CoV-2 varies between a subclinical or flu-like syndrome to that of severe pneumonia with multi-organ failure and death. Initial reports have suggested that cancer patients may have a higher susceptibility to get infected by the SARS-CoV-2 virus but current evidence remains poor as it is biased by important confounders. Patients with ongoing or recent cancer treatment for advanced active disease, metastatic solid tumors and hematological malignancies are at higher risk of developing severe COVID-19 respiratory disease that requires hospitalization and have a poorer disease outcome compared to individuals without cancer. However it is not clear whether these are independent risk factors, or mainly driven by male gender, age, obesity, performance status, uncontrolled diabetes, cardiovascular disease and various other medical conditions. These often have a greater influence on the probability to die due to SARS-CoV-2 then cancer. Delayed diagnosis and suboptimal cancer management due to the pandemic results in disease upstaging and has considerable impact cancer on specific death rates. Surgery during the peak of the pandemic seems to increase mortality, but there is no convincing evidence that adjuvant systemic cancer therapy and radiotherapy are contraindicated, implicating that cancer treatment can be provided safely after individual risk/benefit assessment and some adaptive measures. Underlying immunosuppression, elevated cytokine levels, altered expression of the angiotensin converting enzyme (ACE-2) and TMPRSS2, and a prothrombotic status may fuel the effects of a SARS-CoV-2 in some cancer patients, but have the potential to be used as biomarkers for severe disease and therapeutic targets. The rapidly expanding literature on COVID-19 should be interpreted with care as it is often hampered by methodological and statistical flaws.

Coagulopathy of Coronavirus Disease 2019

OBJECTIVES

Recent studies have reported a high prevalence of thrombotic events in coronavirus disease 2019. However, the significance of thromboembolic complications has not been widely appreciated. The purpose of this review is to provide current knowledge of this serious problem.

DESIGN

Narrative review.

DATA SOURCES

Online search of published medical literature through PubMed using the term "COVID-19," "SARS," "acute respiratory distress syndrome," "coronavirus," "coagulopathy," "thrombus," and "anticoagulants."

STUDY SELECTION AND DATA EXTRACTION

Articles were chosen for inclusion based on their relevance to coagulopathy and thrombosis in coronavirus disease 2019, and anticoagulant therapy. Reference lists were reviewed to identify additional relevant articles.

DATA SYNTHESIS

Coronavirus disease 2019 is associated with a strikingly high prevalence of coagulopathy and venous thromboembolism that may contribute to respiratory deterioration. Monitoring coagulation variables is important, as abnormal coagulation tests are related to adverse outcomes and may necessitate adjuvant antithrombotic interventions. In the initial phase of the infection, D-dimer and fibrinogen levels are increased, while activated partial prothrombin time, prothrombin time, and platelet counts are often relatively normal. Increased D-dimer levels three times the upper limit of normal may trigger screening for venous thromboembolism. In all hospitalized patients, thromboprophylaxis using low-molecular-weight heparin is currently recommended. The etiology of the procoagulant responses is complex and thought to be a result of specific interactions between host defense mechanisms and the coagulation system. Although the coagulopathy is reminiscent of disseminated intravascular coagulation and thrombotic microangiopathy, it has features that are markedly distinct from these entities.

CONCLUSIONS

Severe acute respiratory syndrome coronavirus 2/coronavirus disease 2019 frequently induces hypercoagulability with both microangiopathy and local thrombus formation, and a systemic coagulation defect that leads to large vessel thrombosis and major thromboembolic complications, including pulmonary embolism in critically ill hospitalized patients. D-dimers and fibrinogen levels should be monitored, and all hospitalized patients should undergo thromboembolism prophylaxis with an increase in therapeutic anticoagulation in certain clinical situations.

Role of Tissue Plasminogen Activator for Diffuse Pulmonary Microemboli in Coronavirus Disease 2019 Patient

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)–related hypercoagulability has been of great interest in the pathophysiology of coronavirus disease 2019 (COVID-19). Many patients have clinical findings of dead-space ventilation, similar to pulmonary embolism. Herein, a patient who presented with COVID-19 pneumonia and whose condition rapidly deteriorated to respiratory failure requiring intubation is described. Tissue plasminogen activator (tPA) was administered because of concern of pulmonary microemboli, with improvement of respiratory status and extubation within 24 hours. Patients with COVID-19 infection have an increased risk of thrombus formation,¹ and the administration of tPA may benefit these patients by immediately lysing diffuse thrombi and improving gas exchange.

The Role of Therapeutic Anticoagulation in COVID-19

Coagulopathy has proven to be a common complication of the novel coronavirus SARS-CoV-2, with evidence of elevated D-dimers and fibrin degradation products associated with an increased incidence of thromboembolism. Despite emerging evidence describing the coagulopathy and its clinical relevance in COVID-19, fewer studies have addressed the potential role of empiric therapeutic anticoagulation in this setting. We report the case of a patient admitted to our intensive care unit (ICU) with severe acute respiratory distress syndrome (ARDS) secondary to COVID-19 whose clinical trajectory improved dramatically after initiation of a therapeutic dose of LMWH. The patient showed progressive elevation of fibrinogen and D-dimers despite a prophylactic dose of LMWH during her ICU stay. This was met with a moderate increase of troponin T-hs, an escalating need for vasopressors, and a progressive decrease in her P/F ratio despite preserved lung static compliance. Her platelet count was normal and had an elevated fibrinogen during the first week of ICU stay. The ECG was normal, and a bedside transthoracic echocardiogram showed no evidence of pulmonary embolism and a preserved EF with no regional wall motion abnormalities (RMWA). The chest X-ray was not dissimilar to previous exams, and the ABG showed hypoxia with normal pCO2 values. The decision was made to commence empiric therapeutic enoxaparin. The patient did not experience bleeding complications, and her clinical trajectory appeared to change dramatically. She was successfully extubated three days later and proceeded to clinical recovery and eventual discharge from the ICU. The available evidence shows that there is undoubtedly coagulopathy associated with COVID-19 with various subsequent forms of clinical manifestation described in the literature. Evidence also shows the benefits of heparin as an anticoagulant. From the discussion of this case report, however, it can be concluded that despite the plausible theoretical rationale, studies pertaining to the role of empiric therapeutic anticoagulation in this setting fall short of providing compelling evidence. Subsequently the role of empiric therapeutic anticoagulation in COVID-19 remains unclear with a pressing call for further research.

Current Perspectives of Anticoagulation in Patients With COVID-19

Thromboembolism and myocardial injury is common in patients with COVID-19. Low-molecular-weight heparin appears to be associated with a good prognosis in patients with COVID-19 and has the ability to reduce coagulation and inflammation markers. Hospitalized patients with COVID-19 should be placed on thromboprophylaxis with the option of full therapeutic anticoagulation or tissue plasminogen activator in high-risk or mechanically ventilated patients. Thromboprophylaxis should also be considered at hospital discharge for high-risk patients. Clinical judgment should be used to evaluate the bleeding and safety risk of anticoagulation in patients with COVID-19 without confirmed data.

Study of alteplase for respiratory failure in severe acute respiratory syndrome coronavirus 2/COVID-19: Study design of the phase IIa STARS trial

Background

The coronavirus disease 2019 (COVID-19) pandemic has caused a large surge of acute respiratory distress syndrome (ARDS). Prior phase I trials (non-COVID-19) demonstrated improvement in pulmonary function in patients ARDS using fibrinolytic therapy. A follow-up trial using the widely available tissue-type plasminogen activator (t-PA) alteplase is now needed to assess optimal dosing and safety in this critically ill patient population.

Objective

To describe the design and rationale of a phase IIa trial to evaluate the safety and efficacy of alteplase treatment for moderate/severe COVID-19-induced ARDS.

Patients/Methods

A rapidly adaptive, pragmatic, open-label, randomized, controlled, phase IIa clinical trial will be conducted with 3 groups: intravenous alteplase 50 mg, intravenous alteplase 100 mg, and control (standard-of-care). Inclusion criteria are known/suspected COVID-19 infection with PaO2/FiO2 ratio <150 mm Hg for > 4 hours despite maximal mechanical ventilation management. Alteplase will be delivered through an initial bolus of 50 mg or 100 mg followed by heparin infusion for systemic anticoagulation, with alteplase redosing if there is a >20% PaO2/FiO2 improvement not sustained by 24 hours.

Results

The primary outcome is improvement in PaO2/FiO2 at 48 hours after randomization. Other outcomes include ventilator- and intensive care unit-free days, successful extubation (no reintubation ≤3 days after initial extubation), and mortality. Fifty eligible patients will be enrolled in a rapidly adaptive, modified stepped-wedge design with 4 looks at the data.

Conclusion

Findings will provide timely information on the safety, efficacy, and optimal dosing of t-PA to treat moderate/severe COVID-19-induced ARDS, which can be rapidly adapted to a phase III trial (NCT04357730; FDA IND 149634).

Viral Coagulopathy in Patients With COVID-19: Treatment and Care

COVID-19 has proven to be particularly challenging given the complex pathogenesis of SARS-CoV-2. Early data have demonstrated how the host response to this novel coronavirus leads to the proliferation of pro-inflammatory cytokines, massive endothelial damage, and generalized vascular manifestations. While SARS-CoV-2 primarily targets the upper and lower respiratory tract, other organ systems are also affected. SARS-CoV-2 relies on 2 host cell receptors for successful attachment: angiotensin-converting enzyme 2 and transmembrane protease serine 2. Clinicopathologic reports have demonstrated associations between severe COVID-19 and viral coagulopathy, resulting in pulmonary embolism; venous, arterial, and microvascular thrombosis; lung endothelial injury; and associated thrombotic complications leading to acute respiratory distress syndrome. Viral coagulopathy is not novel given similar observations with SARS classic, including the consumption of platelets, generation of thrombin, and increased fibrin degradation product exhibiting overt disseminated intravascular coagulation–like syndrome. The specific mechanism(s) behind the thrombotic complications in COVID-19 patients has yet to be fully understood. Parenteral anticoagulants, such as heparin and low-molecular-weights heparins, are widely used in the management of COVID-19 patients. Beyond the primary (anticoagulant) effects of these agents, they may exhibit antiviral, anti-inflammatory, and cytoprotective effects. Direct oral anticoagulants and antiplatelet agents are also useful in the management of these patients. Tissue plasminogen activator and other fibrinolytic modalities may also be helpful in the overall management. Catheter-directed thrombolysis can be used in patients developing pulmonary embolism. Further investigations are required to understand the molecular and cellular mechanisms involved in the pathogenesis of COVID-19-associated thrombotic complications.