Chronic anticoagulation is not associated with a reduced risk of acute kidney injury in hospitalised Covid-19 patients.

BACKGROUND: Coronavirus-19 (COVID-19) has been declared a global pandemic by the World Health Organisation. Severe disease typically presents with respiratory failure but Acute Kidney Injury (AKI) and a hypercoagulable state can also occur. Early reports suggest that thrombosis may be linked with AKI. We studied the development of AKI and outcomes of patients with COVID-19 taking chronic anticoagulation therapy. METHODS: Electronic records were reviewed for all adult patients admitted to Manchester University Foundation Trust Hospitals between March 10 and April 302,020 with a diagnosis of COVID-19. Patients with end-stage kidney disease were excluded. AKI was classified as per KDIGO criteria. RESULTS: Of the 1032 patients with COVID-19 studied,164 (15.9%) were taking anticoagulant therapy prior to admission. There were similar rates of AKI between those on anticoagulants and those not anticoagulated (23.8% versus 19.7%) with no difference in the severity of AKI or requirement of renal replacement therapy between groups (1.2% versus 3.5%). Risk factors for AKI included hypertension, pre-existing renal disease and male sex. There was a higher mortality in those taking anticoagulant therapy (40.2% versus 30%). Patients taking anticoagulants were less likely to be admitted to the Intensive Care Unit (8.5% versus 17.4%) and to receive mechanical ventilation (42.9% versus 78.1%). CONCLUSION: Patients on chronic anticoagulant therapy did not have a reduced incidence or severity of AKI suggesting that AKI is unlikely to be thrombotic in nature. Therapeutic anticoagulation is currently still under investigation in randomised controlled studies to determine whether it has a potential role in COVID-19 treatment.

Von Willebrand factor and ADAMTS13 activity as clinical severity markers in patients with COVID-19.

The coronavirus disease 2019 (COVID-19) increases thrombotic risk. The mechanisms that lead to this prothrombotic state are not well established. The main aim was to evaluate the von Willebrand factor (VWF) antigen and plasma ADAMTS13 activity as endothelial injury markers in COVID-19. We present a prospective study in COVID-19 patients recruited in our institution. VWF antigen, ADAMTS13 activity, D-dimer, and fibrinogen were measured during the first week once COVID-19 was diagnosed. Fifty COVID-19 inpatients [44% in the intensive care unit (ICU)] and 102 COVID-19 outpatients were enrolled. Thirty age and gender matched non-COVID-19 ward inpatients and 30 non-COVID-19 healthy individuals were recruited. The COVID-19 inpatients had higher D-dimer, fibrinogen, and VWF antigen levels and a lower ADAMTS13 activity compared with the COVID-19 outpatients (p < 0.05). ICU patients had higher D-dimer and VWF antigen levels compared with the ward patients and the lowest ADAMTS13 activity (p < 0.05). An imbalance in VWF antigen/ADAMTS13 ratio was observed in COVID-19, reaching the highest in ICU patients. In contrast to other ward non-COVID-19 inpatients, a significative reduction in ADAMTS13 activity was observed in all COVID-19 patients. There is an increase in VWF antigen and an ADAMTS13 activity reduction in COVID-19 related to disease severity and could predict poor clinical outcomes. The ADAMTS13 activity reduction could be a marker associated with COVID-19 compared to other non-critical medical conditions.

SARS-CoV-2 interacts with platelets and megakaryocytes via ACE2-independent mechanism.

Evidence suggests that platelets may directly interact with SARS-CoV-2, raising the concern whether ACE2 receptor plays a role in this interaction. The current study showed that SARS-CoV-2 interacts with both platelets and megakaryocytes despite the limited efficiency. Abundance of the conventional receptor ACE2 and alternative receptors or co-factors for SARS-CoV-2 entry was characterized in platelets from COVID-19 patients and healthy persons as well as human megakaryocytes based on laboratory tests or previously reported RNA-seq data. The results suggest that SARS-CoV-2 interacts with platelets and megakaryocytes via ACE2-independent mechanism and may regulate alternative receptor expression associated with COVID-19 coagulation dysfunction.

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.

Determinants of Increased Fibrinogen in COVID-19 Patients With and Without Diabetes and Impaired Fasting Glucose.

BACKGROUND: To investigate the factors associated with elevated fibrinogen (Fbg) levels in COVID-19 patients with and without diabetes (DM) and impaired fasting glucose (IFG). METHODS: According to whether or not their glucose metabolism was impaired, COVID-19 patients were subdivided into 2 groups: 1) with DM and IFG, 2) control group. Their demographic data, medical history, signs and symptoms, laboratory results, and final clinical results were analyzed retrospectively. RESULTS: 28 patients (16.3%) died during hospitalization, including 21 (29.2%) in group 1 and 7 (7.0%) in group 2 (P < 0.001). Fbg levels in groups 1 and 2 were higher than the normal range, at 5.6 g/L (IQR 4.5-7.2 g/L) and 5.0 g/L (IQR 4.0-6.1 g/L), respectively (P = 0.009). Serum ferritin levels, C-reactive protein (CRP), interleukin-6 (IL-6), IL-8, tumor necrosis factor-α (TNF-α), triglycerides (TG) were significantly increased in group 1 compared to those in the control. TG levels were 1.3 mmol/L in the control, while that in group 1 was 1.8 mmol/L. Multiple linear regression showed that the predicting factors of Fbg in the control group were serum ferritin and CRP, R2 = 0.295; in group 1, serum ferritin, CRP, and TG, R2 = 0.473. CONCLUSIONS: Fbg in all COVID-19 patients is related to serum ferritin and CRP involved in inflammation. Furthermore, in COVID-19 patients with insulin resistance, Fbg is linearly positively correlated with TG. This suggests that regulation of TG, insulin resistance, and inflammation may reduce hypercoagulability in COVID-19 patients, especially those with insulin resistance.

Association of D-dimer and Fibrinogen With Hypercoagulability in COVID-19 Requiring Extracorporeal Membrane Oxygenation.

BACKGROUND: D-dimer concentration has been used by institutions to identify candidates for intensified anticoagulant treatment for venous thromboembolism prevention and for the mitigation of the microthrombotic complications associated with COVID-19. Thromboelastography (TEG) maximum amplitude (MA) has been validated as a marker of hypercoagulability and MA ≥68 mm has been utilized as a marker of hypercoagulability in other conditions. METHODS: The goal of this study was to evaluate the relationship between coagulation, inflammatory, and TEG parameters in patients with COVID-19 on extracorporeal membrane oxygenation (ECMO). We performed a single-center retrospective analysis of consecutive patients that received ECMO for the treatment of COVID-19. TEG, inflammatory, and coagulation markers were compared in patients with and without a thrombotic complication. Correlation tests were performed to identify the coagulation and inflammatory markers that best predict hypercoagulability as defined by an elevated TEG MA. RESULTS: A total of 168 TEGs were available in 24 patients. C-reactive protein and fibrinogen were significantly higher in patients that developed a thrombotic event versus those that did not (P = 0.04 and P = 0.04 respectively). D-dimer was negatively correlated with TEG MA (P < 0.01), while fibrinogen was positively correlated (P < 0.01). A fibrinogen >441 mg/dL was found to have a sensitivity of 91.2% and specificity of 85.7% for the detection of MA ≥68 mm. CONCLUSIONS: In critically ill patients with COVID-19 treated with ECMO, D-dimer concentration had an inverse relationship with degree of hypercoagulability as measured by TEG MA. D-dimer elevation may potentially reflect hemostatic perturbation in patients on ECMO or the severity of COVID-19 related sepsis rather than designate patients likely to benefit from anticoagulation. Fibrinogen concentration may represent a more useful marker of hypercoagulability in this population.

Complex and prolonged hypercoagulability in coronavirus disease 2019 intensive care unit patients: A thromboelastographic study.

BACKGROUND: A high number of thrombotic complications have been reported in critically ill patients with coronavirus disease 2019 (COVID-19) and appear to be related to a hypercoagulable state. Evidence regarding detection, management, and monitoring of COVID-19-associated coagulopathy is still missing. We propose to describe the thrombus viscoelastic properties to investigate the mechanisms of hypercoagulability in patients with COVID-19. METHODS: Thromboelastography (TEG) was performed in 24 consecutive patients admitted to a single intensive care unit for COVID-19 pneumonia, and 10 had a second TEG before being discharged alive from the intensive care unit. RESULTS: Compared with a group of 20 healthy participants, patients with COVID-19 had significantly decreased values of reaction time, coagulation time, and lysis index and increased values of α angle, maximum amplitude, clot strength, and coagulation index. Velocity curves were consistent with increased generation of thrombin. These values persisted in surviving patients despite their good clinical course. DISCUSSION: In patients with COVID-19, TEG demonstrates a complex and prolonged hypercoagulable state including fast initiation of coagulation and clot reinforcement, low fibrinolysis, high potential of thrombin generation, and high fibrinogen and platelet contribution. The antithrombotic strategy in patients with COVID-19 during intensive care hospitalisation and after discharge should be investigated in further studies.

Is Mesenteric Ischemia In COVID-19 Patients A Surprise?

Aim. The disease caused by the 2019 novel coronavirus is known predominantly for its respiratory outcomes; a subset of critically ill patients demonstrates clinically remarkable hypercoagulability in which thrombotic events range from acute pulmonary embolism in patients with COVID-19 pneumonia to extremity ischemia. Our observational study aimed to describe the incidence and characteristics, as well as clinical outcomes, of patients presenting and treated for mesenteric ischemia during the COVID-19 pandemic. Material and Methods. Between March 13 and May 13, 2020, 60 patients operated for emergency reasons were analyzed, and it was noticed that 5 of the 6 COVID-positive patients were operated due to mesenteric ischemia. Results. Five of sixty patients (83.3%) applied to our emergency clinic with COVID-19 positive and acute abdomen. Two of them (40%) did not have any comorbidities. All of them (%100) were male. There were no complications and only 1 death (20%). Mean leukocyte, neutrophil, and platelet levels were within the normal range, while the lymphocyte level was near the lower limit. C-Reactive Protein was above the limit in all patients. The mean levels of International Normalized Ratio, Platelet, and Activated Partial Thromboplastin Time were above the limits. While D-dimer levels were close to the upper limit; fibrinogen levels were above the normal limit for each patient. Conclusion. The presence of hypercoagulation status in critical COVID-19 patients should be observed closely, and anticoagulation therapy can be considered in selected patients. More clinical data are needed to examine the role of anticoagulation in COVID-19 treatment.

COVID-19 associated coagulopathy in critically ill patients: A hypercoagulable state demonstrated by parameters of haemostasis and clot waveform analysis.

Patients with COVID-19 are known to be at risk of developing both venous, arterial and microvascular thrombosis, due to an excessive immuno-thrombogenic response to the SARS-CoV-2 infection. Overlapping syndromes of COVID-19 associated coagulopathy with consumptive coagulopathy and microangiopathy can be seen in critically ill patients as well. Blood was collected from 12 Intensive Care Unit (ICU) patients with severe COVID-19 who were on either mechanical ventilation or on high flow oxygen with a PaO2/FiO2 ratio of <300 mmHg. Laboratory tests were performed for parameters of haemostasis, clot waveform analysis and anti-phospholipid antibodies. CWA parameters were raised with elevated aPTT median Min1 (clot velocity) 9.3%/s (IQR 7.1-9.9%/s), elevated PT median Min1 10.3%/s (IQR 7.1-11.1%/s), elevated aPTT median Min2 (clot acceleration) 1.5%/s2 (IQR 1.0-1.6%/s2), elevated PT median Min2 5.2%/s2 (3.6-5.7%/s2), elevated aPTT median Max2 (clot deceleration) 1.3%/s2 (IQR 0.8-1.4%/s2) elevated PT median Max2 3.8%/s2 (IQR 2.6-4.2%/s2), increased aPTT median Delta change (decreased light transmission due to increased clot formation) 87.8% (IQR 70.2-91.8%) and PT median Delta change 33.0%. This together with raised median Factor VIII levels of 262.5%, hyperfibrinogenemia (median fibrinogen levels 7.5 g/L), increased median von Willebrand factor antigen levels 320% and elevated median D-dimer levels 1.7 µg/dl support the diagnosis of COVID-19 associated coagulopathy. A lupus anticoagulant was present in 50% of patients. Our laboratory findings further support the view that severe SARS-CoV-2 infection is associated with a state of hypercoagulability.

Anticoagulant treatment in COVID-19: a narrative review.

The actual Coronavirus Disease (COVID 19) pandemic is due to Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a member of the coronavirus family. Besides the respiratory involvement, COVID 19 patients frequently develop a pro-coagulative state caused by virus-induced endothelial dysfunction, cytokine storm and complement cascade hyperactivation. It is common to observe diffuse microvascular thrombi in multiple organs, mostly in pulmonary microvessels. Thrombotic risk seems to be directly related to disease severity and worsens patients' prognosis. Therefore, the correct understanding of the mechanisms underlying COVID-19 induced prothrombotic state can lead to a thorough assessment of the possible management strategies. Hence, we review the pathogenesis and therapy of COVID 19-related thrombosis disease, focusing on the available evidence on the possible treatment strategies and proposing an algorithm for the anticoagulation strategy based on disease severity.

The haemostatic profile in critically ill COVID-19 patients receiving therapeutic anticoagulant therapy: An observational study.

Hypercoagulability and thrombosis remain a challenge in severe coronavirus disease 2019 (COVID-19) infections. Our aim is to investigate the hemostatic profile of critically ill COVID-19 patients on therapeutic anticoagulant treatment.Forty one patients were enrolled into the study. We recruited 11 consecutive, COVID-19, patients who received therapeutic anticoagulant treatment on intensive care unit (ICU) admission. Disease severity indexes, biochemical, hematological and haemostatic parameters, endogenous thrombin potential (ETP), plasminogen activator inhibitor-1 (PAI-1) activity and extrinsically activated rotational thromboelastometry assay (EXTEM) were recorded on days 1, 3, 7. We also enrolled 9 ICU non-COVID-19, 21 non-ICU COVID-19 patients and 20 healthy blood donors as control populations.Critically ill COVID-19 patients demonstrated a more hypercoagulable and hypofibrinolytic profile related to those with COVID-19 mild illness, based on EXTEM amplitude at 10 min (A10), maximum clot firmness (MCF) and lysis index at 60 min (LI60) variables (p = 0.020, 0.046 and 0.001, respectively). Similarly, a more hypercoagulable state was detected in COVID-19 ICU patients related to non-COVID-19 ICU patients based on A10 and MCF parameters (p = 0.03 and 0.04, respectively). On the contrary, ETP and EXTEM (clotting time) CT values were similar between patients with severe and mild form of the COVID-19 infection, probably due to anticoagulant treatment given.Critically ill COVID-19 patients showed a hypercoagulable profile despite the therapeutic anticoagulant doses given. Due to the small sample size and the study design, the prognostic role of the hypercoagulability in this clinical setting remains unknown and further research is required in order to be assessed.

COVID-19-Associated Coagulopathy: An Exacerbated Immunothrombosis Response.

Since the onset of the global pandemic in early 2020, coronavirus disease 2019 (COVID-19) has posed a multitude of challenges to health care systems worldwide. In order to combat these challenges and devise appropriate therapeutic strategies, it becomes of paramount importance to elucidate the pathophysiology of this illness. Coronavirus disease 2019, caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV2), is characterized by a dysregulated immune system and hypercoagulability. COVID-associated coagulopathy (CAC) was recognized based on profound d-dimer elevations and evidence of microthrombi and macrothrombi, both in venous and arterial systems. The underlying mechanisms associated with CAC have been suggested, but not clearly defined. The model of immunothrombosis illustrates the elaborate crosstalk between the innate immune system and coagulation. The rendering of a procoagulant state in COVID-19 involves the interplay of many innate immune pathways. The SARS-CoV2 virus can directly infect immune and endothelial cells, leading to endothelial injury and dysregulation of the immune system. Activated leukocytes potentiate a procoagulant state via release of intravascular tissue factor, platelet activation, NETosis, and inhibition of anticoagulant mechanisms. Additional pathways of specific relevance in CAC include cytokine release and complement activation. All these mechanisms have recently been reported in COVID-19. Immunothrombosis provides a comprehensive perspective of the several synergistic pathways pertinent to the pathogenesis of CAC.

Current Overview on Hypercoagulability in COVID-19.

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has brought many unique pathologies, such as coagulopathy, prompting a desperate need for effective management. COVID-19-associated coagulopathy (CAC) can cause various thromboembolic complications, especially in critically ill patients. The pathogenesis is likely due to endothelial injury, immobilization, and an increase in circulating prothrombotic factors. Data on treatment are limited, although prophylactic anticoagulation is advised in all hospitalized patients. Herein, we have comprehensively reviewed the current literature available on CAC and highlight the pathogenesis, clinical features, and management of CAC.

Pathogenesis and Treatment Strategies of COVID-19-Related Hypercoagulant and Thrombotic Complications.

The new type of pneumonia caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is endemic worldwide, and many countries cannot be spared, becoming a global health concern. The disease was named COVID-19 by the World Health Organization (WHO) on January 30, 2020, when the WHO declared the Chinese outbreak of COVID-19 to be a public health emergency of international concern. The clinical features of COVID-19 include dry cough, fever, diarrhea, vomiting, and myalgia. Similar to SARS-CoV and MERS-CoV, nearly 20% of patients experienced various fatal complications, including acute kidney injury and acute respiratory distress syndrome caused by cytokine storm. Furthermore, systemic cytokine storm induced vascular endothelial injury, which extensively mediates hypercoagulability in blood vessels and disseminated intravascular coagulation. The autopsy pathology of COVID-19 confirmed the above. This article briefly summarizes the mechanism of hypercoagulability and thrombotic complications of severe COVID-19 and proposes that blood hypercoagulability and intravascular microthrombosis are the development nodes of severe COVID-19. Therefore, anticoagulation and anti-inflammatory therapy can be used as important treatment strategies for severe COVID-19.

Management of Respiratory Distress Syndrome due to COVID-19 infection.

The management of Acute Respiratory Distress Syndrome (ARDS) secondary to the novel Coronavirus Disease 2019 (COVID-19) proves to be challenging and controversial. Multiple studies have suggested the likelihood of an atypical pathophysiology to explain the spectrum of pulmonary and systemic manifestations caused by the virus. The principal paradox of COVID-19 pneumonia is the presence of severe hypoxemia with preserved pulmonary mechanics. Data derived from the experience of multiple centers around the world have demonstrated that initial clinical efforts should be focused into avoid intubation and mechanical ventilation in hypoxemic COVID-19 patients. On the other hand, COVID-19 patients progressing or presenting into frank ARDS with typical decreased pulmonary compliance, represents another clinical enigma to many clinicians, since routine therapeutic interventions for ARDS are still a subject of debate.