Venous thromboembolism prophylaxis practices for patients with sickle cell disease prior to and during the COVID-19 pandemic.

Patients with sickle cell disease (SCD) are predisposed to a hypercoagulable state due to alterations in the coagulation system. Despite concern for the development of venous thromboembolism (VTE) in this population, there are no standardized guidelines for routine thromboprophylaxis. The objective of this study was to assess thromboprophylaxis practices of adult and pediatric treaters of SCD before and during the coronavirus disease of 2019 (COVID-19) pandemic. A cross-sectional electronic survey was distributed to pediatric and adult hematology oncology practitioners through seven SCD-specific interest groups between May 29, 2020, and July 13, 2020. Of 93 total responses, 14% ( N  = 13) reported they only treat patients more than 21 years old; 38.7% ( N  = 36) only treat patients 0-21 years old and 47.3% ( N  = 44) reported they treat both. Our study showed that before the COVID-19 pandemic, 96% of adult practitioners would recommend pharmacologic thromboprophylaxis, mechanical thromboprophylaxis or both for hospitalized adults with thromboprophylaxis, but only 76% of pediatric treaters would recommend any thromboprophylaxis in hospitalized children ( P  < 0.0001), with 24% of pediatric treaters choosing no thromboprophylaxis at all. During the COVID-19 pandemic, pharmacologic thromboprophylaxis specifically was recommended for adults by 94% of treaters and for pediatric patients by 76% of treaters. These findings suggest that despite the lack of evidence-based thromboprophylaxis guidelines in adults and children with thromboprophylaxis, subspecialty treaters routinely provide pharmacologic thromboprophylaxis in their adult patients and will modify their practice in pediatric patients who are considered at a high risk for VTE.

Identifying Neutrophil Extracellular Traps (NETs) in Blood Samples Using Peripheral Smear Autoanalyzers.

Neutrophil Extracellular Traps (NETs) are large neutrophil-derived structures composed of decondensed chromatin, cytosolic, and granule proteins. NETs play an important role in fighting infection, inflammation, thrombosis, and tumor progression processes, yet their fast and reliable identification has been challenging. Smudge cells (SCs) are a subcategory of white cells identified by CellaVision®, a hematology autoanalyzer routinely used in clinical practice that uses digital imaging to generate "manual" differentials of peripheral blood smears. We hypothesize that a proportion of cells identified in the SC category by CellaVision® Hematology Autoanalyzers are actually NETs. We demonstrate that NET-like SCs are not present in normal blood samples, nor are they an artifact of smear preparation. NET-like SCs stain positive for neutrophil markers such as myeloperoxidase, leukocyte alkaline phosphatase, and neutrophil elastase. On flow cytometry, cells from samples with high percent NET-like SCs that are positive for surface DNA are also positive for CD45, myeloperoxidase and markers of neutrophil activation and CD66b. Samples with NET-like SCs have a strong side fluorescent (SFL) signal on the white count and nucleated red cells (WNR) scattergram, representing cells with high nucleic acid content. When compared to patients with low percent SCs, those with a high percentage of SCs have a significantly higher incidence of documented bacterial and viral infections. The current methodology of NET identification is time-consuming, complicated, and cumbersome. In this study, we present data supporting identification of NETs by CellaVision®, allowing for easy, fast, cost-effective, and high throughput identification of NETs that is available in real time and may serve as a positive marker for a bacterial or viral infections.

Outcomes With Direct and Indirect Thrombin Inhibition During Extracorporeal Membrane Oxygenation for COVID-19.

Anticoagulation during extracorporeal membrane oxygenation (ECMO) for Coronovirus Disease 2019 (COVID-19) can be performed by direct or indirect thrombin inhibitors but differences in outcomes with these agents are uncertain. A retrospective, multicenter study was conducted. All consecutive adult patients with COVID-19 placed on ECMO between March 1, 2020 and April 30, 2021 in participating centers, were included. Patients were divided in groups receiving either a direct thrombin inhibitor (DTI) or an indirect thrombin inhibitor such as unfractionated heparin (UFH). Overall, 455 patients with COVID-19 from 17 centers were placed on ECMO during the study period. Forty-four patients did not receive anticoagulation. Of the remaining 411 patients, DTI was used in 160 (39%) whereas 251 (61%) received UFH. At 90-days, in-hospital mortality was 50% (DTI) and 61% (UFH), adjusted hazard ratio: 0.81, 95% confidence interval (CI): 0.49-1.32. Deep vein thrombosis [adjusted odds ratio (aOR): 2.60, 95% CI: 0.90-6.65], ischemic (aOR: 1.58, 95% CI: 0.18-14.0), and hemorrhagic (aOR:1.22, 95% CI: 0.39-3.87) stroke were similar with DTI in comparison to UFH. Bleeding requiring transfusion was lower in patients receiving DTI (aOR: 0.40, 95% CI: 0.18-0.87). Anticoagulants that directly inhibit thrombin are associated with similar in-hospital mortality, stroke, and venous thrombosis and do not confer a higher risk of clinical bleeding in comparison to conventional heparin during ECMO for COVID-19.

Corrected cerebral blood flow and reduced cerebral inflammation in berk sickle mice with higher fetal hemoglobin.

Fetal hemoglobin (HbF) is known to lessen the severity of sickle cell disease (SCD), through reductions in peripheral vaso-occlusive disease and reduced risk for cerebrovascular events. However, the influence of HbF on oxygen delivery to high metabolism tissues like the brain, or its influence on cerebral perfusion, metabolism, inflammation or function have not been widely studied. We employed a Berkley mouse model (BERK) of SCD with gamma transgenes q3 expressing exclusively human α- and ßS-globins with varying levels of γ globin expression to investigate the effect of HbF expression on the brain using magnetic resonance imaging (MRI), MRI diffusion tensor imaging (DTI) and spectroscopy (MRS) and hematological parameters. Hematological parameters improved with increasing γ level expression, as did markers for brain metabolism, perfusion and inflammation. Brain microstructure assessed by DTI fractional anisotropy improved, while myo-inositol levels increased, suggesting improved microstructural integrity and reduced cell loss. Our results suggest that increasing γ levels not only improves sickle peripheral disease, but also improves brain perfusion and oxygen delivery while reducing brain inflammation while protecting brain microstructural integrity.

Increased Incidence of Thrombosis in a Cohort of Cancer Patients with COVID-19.

BACKGROUND: Increased rates of thromboembolism (TE) have been reported in patients with COVID-19, even without prior predisposition to thrombosis. Cancer patients are already predisposed to a hypercoagulable state. This study was designed to assess the TE incidence in COVID-19+ patients with active cancer and its impact on survival. METHODS: Data from cancer patients with documented COVID-19 during the dates March 15th-April 10th, 2020, were retrospectively reviewed. Active cancer was defined as disease treated within the past year. Diagnosis and evaluation of thrombosis were done at the clinicians' discretion. All imaging studies' reports within 30 days of the COVID-19 positive test were reviewed for identification of new arterial and/or venous TE. Patients were followed for 30 days from the date of COVID-19+ test for development of TE, hospital length of stay (LOS), and mortality. RESULTS: Of 90 patients, 11 (12.2%) were found to have 13 new TE within 30 days of COVID-19+ test: 8 (8.9%) arterial and 5 (5.6%) venous. Arterial TE was primarily new strokes and/or microvascular cerebral disease (7) with 1 splenic infarct. Venous TE was superficial (1) and deep (3) venous thromboses with 1 pulmonary embolism. Peak D-dimer (DD) values were numerically higher in the TE group versus those with no TE, median peak DD, 7.7 versus 3.2 µg/mL, p = 0.25. Kidney disease was more frequent among patients with TE (72.7%) versus those without TE (31.6%), p = 0.02. Prophylactic or therapeutic anticoagulation (AC) in the inpatient setting was more common among those without TE, any AC, TE versus no TE, 9.1% versus 79.0%, p < 0.0001. Only 1 patient on enoxaparin prophylaxis developed TE. Mortality was higher in the TE group than in those without TE (hazard ratio: 2.6; 95% CI [1.2-5.6], p = 0.009). Cancer type, presence of metastases, administration of prior chemotherapy, patient setting (inpatient, intensive care unit, outpatient, emergency department visit), LOS, and ventilation did not correlate with increased incidence of TE. CONCLUSION: Cancer patients with COVID-19 have high overall TE rates with a significant incidence of arterial events. TE was associated with worse survival outcomes.

Thrombosis in myeloproliferative neoplasms: Treatment outcomes of direct oral anticoagulants and vitamin K antagonists.

BACKGROUND: Patients with myeloproliferative neoplasms (MPNs), such as polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), are at an increased risk of recurrent thromboembolic events (TEs) and hemorrhagic complications. Anticoagulation with vitamin K antagonists (VKAs) had been the standard of care until the recent US Food and Drug Administration approval of direct oral anticoagulants (DOACs) for treatment of cancer-associated thrombosis. However, since patients with MPNs were underrepresented in large studies, the use of DOACs in patients with MPN-associated thrombosis remains understudied. OBJECTIVES: The primary objective of this study was to establish the incidence of recurrent TEs and hemorrhagic complications in patients with MPN-associated thrombosis treated with DOACs versus VKAs as first-line therapy. METHODS: Data from 30 patients ≥18 years old with established diagnoses of PV or ET who were treated with either DOACs or VKAs as the first-line anticoagulant for arterial and/or venous thrombosis were reviewed to determine the incidence of recurrent TEs as well as hemorrhagic complications. RESULTS: Nineteen patients were treated with DOACs, and 11 were treated with VKAs. Of those on DOACs, 1 had a recurrent thrombosis, and 4 had bleeding events. Of the 11 patients treated with VKAs, 1 had a recurrent thrombotic event, and 1 had a bleeding event. CONCLUSION: Our data did not demonstrate a significant difference in recurrent TEs or bleeding events in patients with MPN-associated thrombosis anticoagulated with either DOACs or VKAs.

Therapeutic Anticoagulation with Heparin in Critically Ill Patients with Covid-19.

BACKGROUND: Thrombosis and inflammation may contribute to morbidity and mortality among patients with coronavirus disease 2019 (Covid-19). We hypothesized that therapeutic-dose anticoagulation would improve outcomes in critically ill patients with Covid-19. METHODS: In an open-label, adaptive, multiplatform, randomized clinical trial, critically ill patients with severe Covid-19 were randomly assigned to a pragmatically defined regimen of either therapeutic-dose anticoagulation with heparin or pharmacologic thromboprophylaxis in accordance with local usual care. The primary outcome was organ support-free days, evaluated on an ordinal scale that combined in-hospital death (assigned a value of -1) and the number of days free of cardiovascular or respiratory organ support up to day 21 among patients who survived to hospital discharge. RESULTS: The trial was stopped when the prespecified criterion for futility was met for therapeutic-dose anticoagulation. Data on the primary outcome were available for 1098 patients (534 assigned to therapeutic-dose anticoagulation and 564 assigned to usual-care thromboprophylaxis). The median value for organ support-free days was 1 (interquartile range, -1 to 16) among the patients assigned to therapeutic-dose anticoagulation and was 4 (interquartile range, -1 to 16) among the patients assigned to usual-care thromboprophylaxis (adjusted proportional odds ratio, 0.83; 95% credible interval, 0.67 to 1.03; posterior probability of futility [defined as an odds ratio <1.2], 99.9%). The percentage of patients who survived to hospital discharge was similar in the two groups (62.7% and 64.5%, respectively; adjusted odds ratio, 0.84; 95% credible interval, 0.64 to 1.11). Major bleeding occurred in 3.8% of the patients assigned to therapeutic-dose anticoagulation and in 2.3% of those assigned to usual-care pharmacologic thromboprophylaxis. CONCLUSIONS: In critically ill patients with Covid-19, an initial strategy of therapeutic-dose anticoagulation with heparin did not result in a greater probability of survival to hospital discharge or a greater number of days free of cardiovascular or respiratory organ support than did usual-care pharmacologic thromboprophylaxis. (REMAP-CAP, ACTIV-4a, and ATTACC ClinicalTrials.gov numbers, NCT02735707, NCT04505774, NCT04359277, and NCT04372589.).

Therapeutic Anticoagulation with Heparin in Noncritically Ill Patients with Covid-19.

BACKGROUND: Thrombosis and inflammation may contribute to the risk of death and complications among patients with coronavirus disease 2019 (Covid-19). We hypothesized that therapeutic-dose anticoagulation may improve outcomes in noncritically ill patients who are hospitalized with Covid-19. METHODS: In this open-label, adaptive, multiplatform, controlled trial, we randomly assigned patients who were hospitalized with Covid-19 and who were not critically ill (which was defined as an absence of critical care-level organ support at enrollment) to receive pragmatically defined regimens of either therapeutic-dose anticoagulation with heparin or usual-care pharmacologic thromboprophylaxis. The primary outcome was organ support-free days, evaluated on an ordinal scale that combined in-hospital death (assigned a value of -1) and the number of days free of cardiovascular or respiratory organ support up to day 21 among patients who survived to hospital discharge. This outcome was evaluated with the use of a Bayesian statistical model for all patients and according to the baseline d-dimer level. RESULTS: The trial was stopped when prespecified criteria for the superiority of therapeutic-dose anticoagulation were met. Among 2219 patients in the final analysis, the probability that therapeutic-dose anticoagulation increased organ support-free days as compared with usual-care thromboprophylaxis was 98.6% (adjusted odds ratio, 1.27; 95% credible interval, 1.03 to 1.58). The adjusted absolute between-group difference in survival until hospital discharge without organ support favoring therapeutic-dose anticoagulation was 4.0 percentage points (95% credible interval, 0.5 to 7.2). The final probability of the superiority of therapeutic-dose anticoagulation over usual-care thromboprophylaxis was 97.3% in the high d-dimer cohort, 92.9% in the low d-dimer cohort, and 97.3% in the unknown d-dimer cohort. Major bleeding occurred in 1.9% of the patients receiving therapeutic-dose anticoagulation and in 0.9% of those receiving thromboprophylaxis. CONCLUSIONS: In noncritically ill patients with Covid-19, an initial strategy of therapeutic-dose anticoagulation with heparin increased the probability of survival to hospital discharge with reduced use of cardiovascular or respiratory organ support as compared with usual-care thromboprophylaxis. (ATTACC, ACTIV-4a, and REMAP-CAP ClinicalTrials.gov numbers, NCT04372589, NCT04505774, NCT04359277, and NCT02735707.).

Saddle Pulmonary Embolism: Demographics, Clinical Presentation, and Outcomes.

Saddle pulmonary embolism is an uncommon type of venous thromboembolism that can lead to sudden hemodynamic collapse and death. Saddle pulmonary embolism can be difficult to recognize, and data on its presentation, clinical features, and associated complications are sparse. We sought to characterize patients with saddle pulmonary embolism. DESIGN: The Montage software (Nuance, Burlington, MA) was used to identify patients to create a retrospective cohort study. SETTING: Montefiore Medical Center from January 1, 2012, to December 31, 2018. PATIENTS: All subjects diagnosed with saddle pulmonary embolism in above time period. INTERVENTIONS: Charts were reviewed for demographics, diagnostics, laboratory data, presenting vital signs, inhospital mortality, 6-month survival, and prevalence of recurrent venous thromboembolism. MEASUREMENTS AND MAIN RESULTS: About 120 patients with saddle pulmonary embolism were identified. Median age was 61 years and 57.5% were women. Events were provoked by a transient risk factor in 43.3%. On presentation, median mean arterial pressures were normal (93 mm Hg). Only five of 120 of patients (4.2%) presented with vitals concerning for massive pulmonary embolism. We found a 9.2% inhospital mortality; an additional 8.6% died within 6 months of discharge. Inhospital mortality was higher in women (11.6%), compared with men (3.9%), but this was not significant (p = 0.28). In 10 patients, both ventilation/perfusion scans and computed tomography pulmonary angiogram were performed. None of the ventilation/perfusion scans diagnosed saddle pulmonary embolism. Thrombus was visualized in the right heart in eight of 105 (7.6%), and this group had a higher inhospital mortality (37.5%). Recurrent venous thromboembolism occurred in 13 of 85 of survivors (15.3%). CONCLUSIONS: Despite presenting without the accepted clinical criteria for massive pulmonary embolism, saddle pulmonary embolism has a very high inhospital mortality. Ventilation/perfusion scan is unable to diagnose saddle pulmonary embolism. Visualized right heart thrombi portend an even higher inhospital mortality.

Treatment of catheter-related thrombosis in patients with hematologic malignancies: A Venous thromboEmbolism Network U.S. retrospective cohort study.

INTRODUCTION: Optimal treatment of catheter-related thrombosis (CRT) is uncertain in patients with hematologic malignancy. We aimed to evaluate the treatment strategies, outcomes, and predictors of recurrent venous thromboembolism (VTE) associated with catheter-related thrombosis (CRT) in patients with hematologic malignancy. METHODS: We performed a multicenter retrospective cohort study of eight institutions through the Venous thromboEmbolism Network US. Patients with hematologic malignancies with documented CRT were identified using ICD-9 and ICD-10 diagnostic codes. Semi-competing risks proportional hazard regression models were created. RESULTS AND CONCLUSIONS: Of the 663 patients in the cohort, 124 (19%) were treated with anticoagulation alone, 388 (58%) were treated with anticoagulation and catheter removal, 119 (18%) treated with catheter removal only, and 32 (5%) had neither catheter removal nor anticoagulation. 100 (15%) patients experienced a recurrent VTE event. In the 579 patients who had catheter removal, the most common reason for catheter removal was the CRT [392 (68%)]. For subjects who received any anticoagulation (n = 512), total anticoagulation duration was not associated with VTE recurrence [1.000 (0.999-1.002)]. After adjustment patients treated with catheter removal only had an increased risk of VTE recurrence [2.50 (1.24-5.07)] and death [4.96 (2.47-9.97)]. Patients with no treatment had increased risk of death [16.81 (6.22-45.38)] and death after VTE recurrence [27.29 (3.13-238.13)]. In this large, multicenter retrospective cohort, we found significant variability in the treatment of CRT in patients with hematologic malignancy. Treatment without anticoagulation was associated with recurrent VTE.

Correlation of Coagulation Parameters With Clinical Outcomes During the Coronavirus-19 Surge in New York: Observational Cohort.

IMPORTANCE: COVID-19 has caused a worldwide illness and New York became the epicenter of COVID-19 in the United States from Mid-March to May 2020. OBJECTIVE: To investigate the coagulopathic presentation of COVID and its natural course during the early stages of the COVID-19 surge in New York. To investigate whether hematologic and coagulation parameters can be used to assess illness severity and death. DESIGN: Retrospective case study of positive COVID inpatients between March 20, 2020-March 31, 2020. SETTING: Montefiore Health System main hospital, Moses, a large tertiary care center in the Bronx. PARTICIPANTS: Adult inpatients with positive COVID tests hospitalized at MHS. EXPOSURE FOR OBSERVATIONAL STUDIES: Datasets of participants were queried for demographic (age, sex, socioeconomic status, and self-reported race and/or ethnicity), clinical and laboratory data. MAIN OUTCOME AND MEASURES: Relationship and predictive value of measured parameters to mortality and illness severity. RESULTS: Of the 225 in this case review, 75 died during hospitalization while 150 were discharged home. Only the admission PT, absolute neutrophil count (ANC) and first D-Dimer could significantly differentiate those who were discharged alive and those who died. Logistic regression analysis shows increased odds ratio for mortality by first D-Dimer within 48 hrs. of admission. The optimal cut-point for the initial D-Dimer to predict mortality was found to be 2.1 µg/mL. 15% of discharged patients required readmission and more than a third of readmitted patients died (5% of all initially discharged). CONCLUSION: We describe here a comprehensive assessment of hematologic and coagulation parameters in COVID-19 and examine the relationship of these to mortality. We demonstrate that both initial and maximum D-Dimer values are biomarkers that can be used for survival assessments. Furthermore, D-Dimer may be useful to follow up discharged patients.

Approach to Cancer-Associated Thrombosis: Challenging Situations and Knowledge Gaps.

Malignancy is a significant risk factor for venous thromboembolism (VTE). It is estimated that up to 20% of patients with cancer may develop VTE at some time in their cancer journey. Cancer-associated VTE can lead to hospitalizations, morbidity, delayed cancer treatment, and mortality. The optimal prevention and management of cancer-associated thrombosis (CAT) is of utmost importance. Direct oral anticoagulants have been recommended as first-line therapy for VTE treatment in the general population and their efficacy has recently been demonstrated in the cancer population, leading to increased use. However, patients with cancer have unique challenges and comorbidities that can lead to increased risks and concerns with anticoagulation. Herein we will discuss commonly encountered challenges in patients with CAT, review available literature, and provide practice suggestions. IMPLICATIONS FOR PRACTICE: This article aims to specifically address cancer-associated thrombosis issues for which there is limited or absent evidence to guide best practice, for circumstances that pose unique challenges for clinicians, and for directions when the literature is conflicting. It reviews pertinent data for each selected topic and provides guidance for patient management based on the best available evidence and experiences from the panel.

North American Physician Practice Patterns in the Management of Anticoagulation in Pregnancy.

Background: During pregnancy and in the postpartum period women are at increased risk of venous thromboembolism (VTE) owing to hypercoagulability and mechanical issues, as well as nonpregnancy conditions including inherited and acquired thrombophilia. Although guidelines exist for the use of thromboprophylaxis in this setting, there are differences in the specifics of the recommendations among expert societies. We assessed the current practice patterns of North American providers in the prevention of pregnancy-associated VTE in women with thrombophilia. Methods: A survey was created and distributed with case studies and questions addressing VTE prevention during the antepartum and postpartum periods. Results: Surveys were completed by 28% of adult providers queried, with broad geographic representation. There was consistent use of a prophylactic dose of low-molecular weight heparin (LMWH) ante- and postpartum for individuals with low-risk thrombophilia and past estrogen-provoked VTE but a lack of a consensus of anticoagulant (AC) use and dose in individuals with higher risk thrombophilia. There was variability in the dose selection and monitoring of AC when using induction versus spontaneous labor, with 47% of providers switching from LMWH to unfractionated heparin for those not having a scheduled delivery, and there were differences in the duration of postpartum prophylaxis based upon delivery mode. Conclusion: In this survey of North American experienced specialists' responses to a variety of commonly encountered scenarios of thrombophilia and pregnancy and the management of AC were not always consistent with published guidelines.

Anticoagulation in COVID-19: Effect of Enoxaparin, Heparin, and Apixaban on Mortality.

BACKGROUND: Mortality in coronavirus disease of 2019 (COVID-19) is associated with increases in prothrombotic parameters, particularly D-dimer levels. Anticoagulation has been proposed as therapy to decrease mortality, often adjusted for illness severity. OBJECTIVE: We wanted to investigate whether anticoagulation improves survival in COVID-19 and if this improvement in survival is associated with disease severity. METHODS: This is a cohort study simulating an intention-to-treat clinical trial, by analyzing the effect on mortality of anticoagulation therapy chosen in the first 48 hours of hospitalization. We analyzed 3,625 COVID-19+ inpatients, controlling for age, gender, glomerular filtration rate, oxygen saturation, ventilation requirement, intensive care unit admission, and time period, all determined during the first 48 hours. RESULTS: Adjusted logistic regression analyses demonstrated a significant decrease in mortality with prophylactic use of apixaban (odds ratio [OR] 0.46, p = 0.001) and enoxaparin (OR = 0.49, p = 0.001). Therapeutic apixaban was also associated with decreased mortality (OR 0.57, p = 0.006) but was not more beneficial than prophylactic use when analyzed over the entire cohort or within D-dimer stratified categories. Higher D-dimer levels were associated with increased mortality (p < 0.0001). When adjusted for these same comorbidities within D-dimer strata, patients with D-dimer levels < 1 µg/mL did not appear to benefit from anticoagulation while patients with D-dimer levels > 10 µg/mL derived the most benefit. There was no increase in transfusion requirement with any of the anticoagulants used. CONCLUSION: We conclude that COVID-19+ patients with moderate or severe illness benefit from anticoagulation and that apixaban has similar efficacy to enoxaparin in decreasing mortality in this disease.