Thrombotic Events in COVID-19 Are Associated With a Lower Use of Prophylactic Anticoagulation Before Hospitalization and Followed by Decreases in Platelet Reactivity

Background: Coronavirus disease of 2019 (COVID-19) is associated with a prothrombotic state and a high incidence of thrombotic event(s) (TE). Objectives: To study platelet reactivity in hospitalized COVID-19 patients and determine a possible association with the clinical outcomes thrombosis and all-cause mortality. Methods: Seventy nine hospitalized COVID-19 patients were enrolled in this retrospective cohort study and provided blood samples in which platelet reactivity in response to stimulation with ADP and TRAP-6 was determined using flow cytometry. Clinical outcomes included thrombotic events, and all-cause mortality. Results: The incidence of TE in this study was 28% and all-cause mortality 16%. Patients that developed a TE were younger than patients that did not develop a TE [median age of 55 vs. 70 years; adjusted odds ratio (AOR) = 0.96 per 1 year of age, 95% confidence interval (CI) 0.92–1.00; p = 0.041]. Furthermore, patients using preexisting thromboprophylaxis were less likely to develop a thrombotic complication than patients that were not (18 vs. 54%; AOR = 0.19, 95% CI 0.04–0.84; p = 0.029). Conversely, having asthma strongly increased the risk on TE development (AOR = 6.2, 95% CI 1.15–33.7; p = 0.034). No significant differences in baseline P-selectin expression or platelet reactivity were observed between the COVID-19 positive patients (n = 79) and COVID-19 negative hospitalized control patients (n = 21), nor between COVID-19 positive survivors or non-survivors. However, patients showed decreased platelet reactivity in response to TRAP-6 following TE development. Conclusion: We observed an association between the use of preexisting thromboprophylaxis and a decreased risk of TE during COVID-19. This suggests that these therapies are beneficial for coping with COVID-19 associated hypercoagulability. This highlights the importance of patient therapy adherence. We observed lowered platelet reactivity after the development of TE, which might be attributed to platelet desensitization during thromboinflammation

Lupus anticoagulant associates with thrombosis in patients with COVID-19 admitted to intensive care units: A retrospective cohort study

Background: Thrombosis is a frequent and severe complication in patients with coronavirus disease 2019 (COVID-19) admitted to the intensive care unit (ICU). Lupus anticoagulant (LA) is a strong acquired risk factor for thrombosis in various diseases and is frequently observed in patients with COVID-19. Whether LA is associated with thrombosis in patients with severe COVID-19 is currently unclear. Objective: To investigate if LA is associated with thrombosis in critically ill patients with COVID-19. Patients/Methods: The presence of LA and other antiphospholipid antibodies was assessed in patients with COVID-19 admitted to the ICU. LA was determined with dilute Russell's viper venom time (dRVVT) and LA-sensitive activated partial thromboplastin time (aPTT) reagents. Results: Of 169 patients with COVID-19, 116 (69%) tested positive for at least one antiphospholipid antibody upon admission to the ICU. Forty (24%) patients tested positive for LA; of whom 29 (17%) tested positive with a dRVVT, 19 (11%) tested positive with an LA-sensitive aPTT, and 8 (5%) tested positive on both tests. Fifty-eight (34%) patients developed thrombosis after ICU admission. The odds ratio (OR) for thrombosis in patients with LA based on a dRVVT was 2.5 (95% confidence interval [CI], 1.1-5.7), which increased to 4.5 (95% CI, 1.4-14.3) in patients at or below the median age in this study (64 years). LA positivity based on a dRVVT or LA-sensitive aPTT was only associated with thrombosis in patients aged less than 65 years (OR, 3.8; 95% CI, 1.3-11.4) and disappeared after adjustment for C-reactive protein. Conclusion: Lupus anticoagulant on admission is strongly associated with thrombosis in critically ill patients with COVID-19, especially in patients aged less than 65 years

Caging the dragon: Research approach to COVID-19-related thrombosis

The incidence of venous thrombosis, mostly pulmonary embolism (PE), ranging from local immunothrombosis to central emboli, but also deep vein thrombosis (DVT) in people with coronavirus disease 2019 (COVID-19) is reported to be remarkably high. The relevance of better understanding, predicting, treating, and preventing COVID-19-associated venous thrombosis meets broad support, as can be concluded from the high number of research, review, and guideline papers that have been published on this topic. The Dutch COVID & Thrombosis Coalition (DCTC) is a multidisciplinary team involving a large number of Dutch experts in the broad area of venous thrombosis and hemostasis research, combined with experts on virology, critically ill patients, pulmonary diseases, and community medicine, across all university hospitals and many community hospitals in the Netherlands. Within the consortium, clinical data of at least 5000 admitted COVID-19-infected individuals are available, including substantial collections of biobanked materials in an estimated 3000 people. In addition to considerable experience in preclinical and clinical thrombosis research, the consortium embeds virology-hemostasis research models within unique biosafety facilities to address fundamental questions on the interaction of virus with epithelial and vascular cells, in relation to the coagulation and inflammatory system. The DCTC has initiated a comprehensive research program to answer many of the current questions on the pathophysiology and best anticoagulant treatment of COVID-19-associated thrombotic complications. The research program was funded by grants of the Netherlands Thrombosis Foundation and the Netherlands Organization for Health Research and Development. Here, we summarize the design and main aims of the research program

Absence of COVID-19-associated changes in plasma coagulation proteins and pulmonary thrombosis in the ferret model

BACKGROUND: Many patients who are diagnosed with coronavirus disease 2019 (COVID-19) suffer from venous thromboembolic complications despite the use of stringent anticoagulant prophylaxis. Studies on the exact mechanism(s) underlying thrombosis in COVID-19 are limited as animal models commonly used to study venous thrombosis pathophysiology (i.e. rats and mice) are naturally not susceptible to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Ferrets are susceptible to SARS-CoV-2 infection, successfully used to study virus transmission, and have been previously used to study activation of coagulation and thrombosis during influenza virus infection. OBJECTIVES: This study aimed to explore the use of (heat-inactivated) plasma and lung material from SARS-CoV-2-inoculated ferrets studying COVID-19-associated changes in coagulation and thrombosis. MATERIAL AND METHODS: Histology and longitudinal plasma profiling using mass spectrometry-based proteomics approach was performed. RESULTS: Lungs of ferrets inoculated intranasally with SARS-CoV-2 demonstrated alveolar septa that were mildly expanded by macrophages, and diffuse interstitial histiocytic pneumonia. However, no macroscopical or microscopical evidence of vascular thrombosis in the lungs of SARS-CoV-2-inoculated ferrets was found. Longitudinal plasma profiling revealed minor differences in plasma protein profiles in SARS-CoV-2-inoculated ferrets up to 2 weeks post-infection. The majority of plasma coagulation factors were stable and demonstrated a low coefficient of variation. CONCLUSIONS: We conclude that while ferrets are an essential and well-suited animal model to study SARS-CoV-2 transmission, their use to study SARS-CoV-2-related changes relevant to thrombotic disease is limited

Stability of vitamin K antagonist anticoagulation after COVID-19 diagnosis

Background: Coagulopathy has been reported in severely ill patients with coronavirus disease 2019 (COVID-19). It is unclear whether outpatients with COVID-19 who are treated with vitamin K antagonists (VKAs) have unstable anticoagulation.Objective: To assess the stability of VKA therapy in patients with COVID-19 through a case-crossover study.Methods: Between February and July 2020, we included patients who tested positive for COVID-19 from two anticoagulant clinics in the Netherlands. We collected international normalized ratios (INRs) determined between 26 weeks before infection and 12 weeks after. Time in therapeutic range (TTR) and the variance growth rate ( VGR) were calculated within patients.Results: Fifty-one patients with COVID-19 (mean age, 84 years) were included, of whom 15 (29%) were men. Mean TTR in the 26 weeks before COVID-19 was 80% (95% confidence interval [CI], 75-85) compared to 59% (95% CI, 51-68) in the 6 weeks after infection. Mean TTR difference was-23% (95% CI, -32 to -14) with a time above therapeutic range of 38% (95% CI, 30-47) in the 6 weeks after infection. The TTR rose again to 79% (95% CI, 69-89) between 6 and 12 weeks after infection. Also, VGR increased, with a mean increase of 4.8 (95% CI, 2.1-7.5) in the 6 weeks after infection. In the 26 weeks before infection, we registered 19 of 641 (3%) of INR >= 5.0 compared with 35 of 247 (14%) in the 6 weeks after (risk ratio, 4.4; 95% CI, 2.7-7.3).Conclusions: COVID-19 is associated with a strong decrease in TTR and in therapeutic stability in patients taking VKAs. Additional monitoring in these patients is advised to maximize therapeutic stability.Clinical epidemiolog

Caging the dragon: research approach to COVID-19-related thrombosis

The incidence of venous thrombosis, mostly pulmonary embolism (PE), ranging from local immunothrombosis to central emboli, but also deep vein thrombosis (DVT) in people with coronavirus disease 2019 (COVID-19) is reported to be remarkably high. The relevance of better understanding, predicting, treating, and preventing COVID-19-associated venous thrombosis meets broad support, as can be concluded from the high number of research, review, and guideline papers that have been published on this topic. The Dutch COVID & Thrombosis Coalition (DCTC) is a multidisciplinary team involving a large number of Dutch experts in the broad area of venous thrombosis and hemostasis research, combined with experts on virology, critically ill patients, pulmonary diseases, and community medicine, across all university hospitals and many community hospitals in the Netherlands. Within the consortium, clinical data of at least 5000 admitted COVID-19-infected individuals are available, including substantial collections of biobanked materials in an estimated 3000 people. In addition to considerable experience in preclinical and clinical thrombosis research, the consortium embeds virology-hemostasis research models within unique biosafety facilities to address fundamental questions on the interaction of virus with epithelial and vascular cells, in relation to the coagulation and inflammatory system. The DCTC has initiated a comprehensive research program to answer many of the current questions on the pathophysiology and best anticoagulant treatment of COVID-19-associated thrombotic complications. The research program was funded by grants of the Netherlands Thrombosis Foundation and the Netherlands Organization for Health Research and Development. Here, we summarize the design and main aims of the research program.Clinical epidemiolog

Early effects of unfractionated heparin on clinical and radiological signs and D-dimer levels in patients with COVID-19 associated pulmonary embolism: an observational cohort study

Perioperative Medicine: Efficacy, Safety and Outcome (Anesthesiology/Intensive Care

Risk of thrombotic complications in influenza versus COVID-19 hospitalized patients

Background: Whereas accumulating studies on patients with coronavirus disease 2019 (COVID-19) report high incidences of thrombotic complications, large studies on clinically relevant thrombosis in patients with other respiratory tract infections are lacking. How this high risk in COVID-19 patients compares to those observed in hospitalized patients with other viral pneumonias such as influenza is unknown.Objectives: To assess the incidence of venous and arterial thrombotic complications in hospitalized patients with influenza as opposed to that observed in hospitalized patients with COVID-19.Methods: This was a retrospective cohort study; we used data from Statistics Netherlands (study period: 2018) on thrombotic complications in hospitalized patients with influenza. In parallel, we assessed the cumulative incidence of thrombotic complications-adjusted for competing risk of death-in patients with COVID-19 in three Dutch hospitals (February 24 to April 26, 2020).Results: Of the 13 217 hospitalized patients with influenza, 437 (3.3%) were diagnosed with thrombotic complications, versus 66 (11%) of the 579 hospitalized patients with COVID-19. The 30-day cumulative incidence of any thrombotic complication in influenza was 11% (95% confidence interval [CI], 9.4-12) versus 25% (95% CI, 18-32) in COVID-19. For venous thrombotic (VTC) complications and arterial thrombotic complications alone, these numbers were, respectively, 3.6% (95% CI, 2.7-4.6) and 7.5% (95% CI, 6.3-8.8) in influenza versus 23% (95% CI, 16-29) and 4.4% (95% CI, 1.9-8.8) in COVID-19.Conclusions: The incidence of thrombotic complications in hospitalized patients with influenza was lower than in hospitalized patients with COVID-19. This difference was mainly driven by a high risk of VTC complications in the patients with COVID-19 admitted to the Intensive Care Unit. Remarkably, patients with influenza were more often diagnosed with arterial thrombotic complications.Perioperative Medicine: Efficacy, Safety and Outcome (Anesthesiology/Intensive Care

Caging the dragon:Research approach to COVID-19-related thrombosis

The incidence of venous thrombosis, mostly pulmonary embolism (PE), ranging from local immunothrombosis to central emboli, but also deep vein thrombosis (DVT) in people with coronavirus disease 2019 (COVID-19) is reported to be remarkably high. The relevance of better understanding, predicting, treating, and preventing COVID-19-associated venous thrombosis meets broad support, as can be concluded from the high number of research, review, and guideline papers that have been published on this topic. The Dutch COVID & Thrombosis Coalition (DCTC) is a multidisciplinary team involving a large number of Dutch experts in the broad area of venous thrombosis and hemostasis research, combined with experts on virology, critically ill patients, pulmonary diseases, and community medicine, across all university hospitals and many community hospitals in the Netherlands. Within the consortium, clinical data of at least 5000 admitted COVID-19-infected individuals are available, including substantial collections of biobanked materials in an estimated 3000 people. In addition to considerable experience in preclinical and clinical thrombosis research, the consortium embeds virology-hemostasis research models within unique biosafety facilities to address fundamental questions on the interaction of virus with epithelial and vascular cells, in relation to the coagulation and inflammatory system. The DCTC has initiated a comprehensive research program to answer many of the current questions on the pathophysiology and best anticoagulant treatment of COVID-19-associated thrombotic complications. The research program was funded by grants of the Netherlands Thrombosis Foundation and the Netherlands Organization for Health Research and Development. Here, we summarize the design and main aims of the research program.Clinical epidemiolog