Acute Mesenteric Ischemia in COVID-19 While Receiving Prophylactic Enoxaparin.

COVID-19 infection is known to cause thromboembolic complications. This is why patients hospitalized with COVID-19 are put on prophylactic anticoagulation. We present the case of a Caucasian woman, aged 71 years, with risk factors of class 1 obesity, hyperlipidemia, and hypertension, initially admitted for COVID-19 pneumonia, and later developed acute mesenteric ischemia followed by pulmonary embolism. These incidents occurred while the patient was receiving high-dose prophylactic enoxaparin (40 mg twice daily). COVID-19 associated acute mesenteric ischemia is a complication with high mortality. Therefore, high suspicion, early recognition, and surgical management is necessary. Apart from that, this case emphasizes the question of whether there is a need for proactively administering therapeutic anticoagulation for high thrombotic risk COVID-19 patients to prevent deadly complications.

Clinical evaluation of the safety and efficacy of enoxaparin in patients with COVID-19.

BACKGROUND: Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), increases thrombotic risk in hospitalised patients. The rate of thrombosis in patients with COVID-19 is unclear. The role of heparin, frequently used in the management of hospitalised patients, also needs to be clarified. In this study, we investigated the efficacy and safety of enoxaparin given at prophylactic or therapeutic dose in hospitalised patients with COVID-19, and evaluated its role in the development of disease in terms of mortality, and incidence of thrombotic and bleeding events. MATERIAL AND METHODS: We included 141 patients with SARS-CoV-2 infection, admitted to five different wards (one intensive care unit, 2 sub-intensive care units, and 2 general infectious disease units) of Cotugno Hospital, a tertiary care hospital in Naples, Italy, between March and May 2020. RESULTS: Over a median time of 17 days (IQR 11-25), enoxaparin was given to 90/141 patients (63.8%) of whom 65 took a prophylactic and 25 a therapeutic dose. We documented 14 episodes of thrombosis (9.9%); almost all were cases of pulmonary embolism. No significant difference in terms of thromboembolic prevention was found between those patients not receiving anticoagulants and those on prophylactic or therapeutic dose of enoxaparin. Five episodes of major bleeding occurred (3.5%); therapeutic dose of enoxaparin was associated with a greater bleeding risk than prophylactic dose (p=0.002). During follow-up, 31 patients (22%) died; these were mostly elderly men with two or more comorbidities at admission. No advantages of enoxaparin, either as prophylaxis or at high doses, in terms of mortality were observed. At multivariate analysis, low estimated glomerular filtration rate, and high total bilirubin and fasting hyperglycemia were independently associated with a higher mortality. DISCUSSION: We did not observe advantages in terms of either thromboembolic prevention or mortality of enoxaparin, which however was more frequently used in patients with more severe disease. Prophylactic enoxaparin was not seen to be associated with bleeding risk.

Thromboprophylaxis and clinical outcomes in moderate COVID-19 patients: A comparative study.

BACKGROUND: Many thrombotic complications are linked to coronavirus disease 2019 (COVID-19). Antithrombotic treatments are important for prophylaxis against these thrombotic events. OBJECTIVES: This study was designed to compare enoxaparin and rivaroxaban as prophylactic anticoagulants in moderate cases of COVID-19 in terms of efficacy, safety, and clinical outcomes. METHODS: The study involved 124 patients with moderate COVID-19 (pneumonia without hypoxia) divided into two groups. The first group (G1) comprised 66 patients who received enoxaparin subcutaneously at a dose of 0.5 mg/kg every 12 h until discharge from the hospital. The second group (G2) comprised 58 patients who received oral rivaroxaban at a dose of 10 mg once daily until discharge from the hospital. The outcomes evaluated in this study were as follows: intermediate care unit (IMCU) duration, the number of patients transferred from the IMCU to the intensive care unit (ICU), ICU duration, the total length of hospital stay, in-hospital mortality, and thrombotic and bleeding complications. RESULTS: No significant differences in IMCU duration (p = 0.39), ICU duration (p = 0.96), and total length of hospital stay (p = 0.73) were observed between the two groups. The percentage of patients requiring ICU admission after hospitalization was 21.2% in G1 and 22.4% in G2 (p = 0.87). The mortality rate was 12.1% in G1 and 10.3% in G2 (p = 0.76). The proportion of patients who had thrombotic complications was 9.1% in G1 and 12.1% in G2 (p = 0.59). The incidence of mild bleeding was 3% in G1 and 1.7% in G2 (p = 0.64). CONCLUSION: Either enoxaparin or rivaroxaban may be used as thromboprophylaxis agents in managing patients with moderate COVID-19. Either medication has no clear advantage over the other.

Enoxaparin for primary thromboprophylaxis in symptomatic outpatients with COVID-19 (OVID): a randomised, open-label, parallel-group, multicentre, phase 3 trial.

BACKGROUND: COVID-19 is a viral prothrombotic respiratory infection. Heparins exert antithrombotic and anti-inflammatory effects, and might have antiviral properties. We aimed to investigate whether thromboprophylaxis with enoxaparin would prevent untoward hospitalisation and death in symptomatic, but clinically stable outpatients with COVID-19. METHODS: OVID was a randomised, open-label, parallel-group, investigator-initiated, phase 3 trial and was done at eight centres in Switzerland and Germany. Outpatients aged 50 years or older with acute COVID-19 were eligible if they presented with respiratory symptoms or body temperature higher than 37·5°C. Eligible participants underwent block-stratified randomisation (by age group 50-70 vs >70 years and by study centre) in a 1:1 ratio to receive either subcutaneous enoxaparin 40 mg once daily for 14 days versus standard of care (no thromboprophylaxis). The primary outcome was a composite of any untoward hospitalisation and all-cause death within 30 days of randomisation. Analysis of the efficacy outcomes was done in the intention-to-treat population. The primary safety outcome was major bleeding. The study was registered in ClinicalTrials.gov (NCT04400799) and has been completed. FINDINGS: At the predefined formal interim analysis for efficacy (50% of total study population), the independent Data Safety Monitoring Board recommended early termination of the trial on the basis of predefined statistical criteria having considered the very low probability of showing superiority of thromboprophylaxis with enoxaparin for the primary outcome under the initial study design assumptions. Between Aug 15, 2020, and Jan 14, 2022, from 3319 participants prescreened, 472 were included in the intention-to-treat population and randomly assigned to receive enoxaparin (n=234) or standard of care (n=238). The median age was 57 years (IQR 53-62) and 217 (46%) were women. The 30-day risk of the primary outcome was similar in participants allocated to receive enoxaparin and in controls (8 [3%] of 234 vs 8 [3%] of 238; adjusted relative risk 0·98; 95% CI 0·37-2·56; p=0·96). All hospitalisations were related to COVID-19. No deaths were reported during the study. No major bleeding events were recorded. Eight serious adverse events were recorded in the enoxaparin group versus nine in the control group. INTERPRETATION: These findings suggest thromboprophylaxis with enoxaparin does not reduce early hospitalisations and deaths among outpatients with symptomatic COVID-19. Futility of the treatment under the initial study design assumptions could not be conclusively assessed owing to under-representation of older patients and consequent low event rates. FUNDING: SNSF (National Research Programme COVID-19 NRP78: 198352), University Hospital Zurich, University of Zurich, Dr-Ing Georg Pollert (Berlin), Johanna Dürmüller-Bol Foundation.

Thromboprophylactic low-molecular-weight heparin versus standard of care in unvaccinated, at-risk outpatients with COVID-19 (ETHIC): an open-label, multicentre, randomised, controlled, phase 3b trial.

BACKGROUND: COVID-19 is associated with inflammation and an increased risk of thromboembolic complications. Prophylactic doses of low-molecular-weight heparin have been used in hospitalised and non-critically ill patients with COVID-19. We aimed to evaluate the efficacy and safety of prophylactic low-molecular-weight heparin (enoxaparin) versus standard of care (no enoxaparin) in at-risk outpatients with COVID-19. METHODS: This open-label, multicentre, randomised, controlled, phase 3b trial (ETHIC) was done at 15 centres in six countries (Belgium, Brazil, India, South Africa, Spain, and the UK). We consecutively enrolled participants aged at least 30 years who had not received a COVID-19 vaccine and had symptomatic, confirmed COVID-19 in the outpatient setting plus at least one risk factor for severe disease. Within 9 days of symptom onset and by use of a web-based random block design (block size either 2 or 4), eligible participants were randomly assigned (1:1) to receive either subcutaneous enoxaparin for 21 days (40 mg once daily if they weighed <100 kg and 40 mg twice daily if they weighed ≥100 kg) or standard of care (without enoxaparin). The primary efficacy endpoint was the composite of all-cause hospitalisation and all-cause mortality at 21 days after randomisation and, in our main analysis, was analysed in the intention-to-treat population, which comprised all patients who were randomly assigned. Safety was also analysed in the intention-to-treat population for our main analysis. This trial is registered with ClinicalTrials.gov, NCT04492254, and is complete. FINDINGS: Following the advice of the Data and Safety Monitoring Board, this study was terminated early due to slow enrolment and a lower-than-expected event rate. Between Oct 27, 2020, and Nov 8, 2021, 230 patients with COVID-19 were assessed for eligibility, of whom 219 were enrolled and randomly assigned to receive standard of care (n=114) or enoxaparin (n=105). 96 (44%) patients were women, 122 (56%) were men, and one patient had missing sex data. 141 (65%) of 218 participants with data on race and ethnicity were White, 60 (28%) were Asian, and 16 (7%) were Black, mixed race, or Arab or Middle Eastern. Median follow-up in both groups was 21 days (IQR 21-21). There was no difference in the composite of all-cause mortality and hospitalisation at 21 days between the enoxaparin group (12 [11%] of 105 patients) and the standard-of-care group (12 [11%] of 114 patients; unadjusted hazard ratio 1·09 [95% CI 0·49-2·43]; log-rank p=0·83). At 21 days, two (2%) of 105 patients in the enoxaparin group (one minor bleed and one bleed of unknown severity) and one (1%) of 114 patients in the standard-of-care group (major abnormal uterine bleeding) had a bleeding event. 22 (21%) patients in the enoxaparin group and 13 (11%) patients in the standard-of-care group had adverse events. The most common adverse event in both groups was COVID-19-related pneumonia (six [6%] patients in the enoxaparin group and five [4%] patients in the standard-of-care group). One patient in the enoxaparin group died and their cause of death was unknown. INTERPRETATION: The ETHIC trial results suggest that prophylaxis with low-molecular-weight heparin had no benefit for at-risk outpatients with COVID-19. Although the trial was terminated early, our data, combined with data from similar studies, provide further insights to inform international guidelines and influence clinical practice. FUNDING: The Thrombosis Research Institute and Sanofi UK.

Enoxaparin Thromboprophylaxis in Children Hospitalized for COVID-19: A Phase 2 Trial.

BACKGROUND: Evidence regarding the safety and efficacy of anticoagulant thromboprophylaxis among pediatric patients hospitalized for coronavirus disease 2019 (COVID-19) is limited. We sought to evaluate safety, dose-finding, and preliminary efficacy of twice-daily enoxaparin as primary thromboprophylaxis among children hospitalized for symptomatic COVID-19, including primary respiratory infection and multisystem inflammatory syndrome in children (MISC). METHODS: We performed a phase 2, multicenter, prospective, open-label, single-arm clinical trial of twice-daily enoxaparin (initial dose: 0.5mg/kg per dose; max: 60mg; target anti-Xa activity: 0.20-0.49IU/mL) as primary thromboprophylaxis for children <18 years of age hospitalized for symptomatic COVID-19. Study endpoints included: cumulative incidence of International Society of Thrombosis and Haemostasis-defined clinically relevant bleeding; enoxaparin dose-requirements; and cumulative incidence of venous thromboembolism within 30-days of hospital discharge. Descriptive statistics summarized endpoint estimates that were further evaluated by participant age (±12 years) and clinical presentation. RESULTS: Forty children were enrolled and 38 met analyses criteria. None experienced clinically relevant bleeding. Median (interquartile range) dose to achieve target anti-Xa levels was 0.5 mg/kg (0.48-0.54). Dose-requirement did not differ by age (0.5 [0.46-0.52] mg/kg for age ≥12 years versus 0.52 [0.49-0.55] mg/kg for age <12 years, P = .51) but was greater for participants with MISC (0.52 [0.5-0.61] mg/kg) as compared with primary COVID-19 (0.48 [0.39-0.51] mg/kg, P = .010). Two children (5.3%) developed central-venous catheter-related venous thromboembolism. No serious adverse events were related to trial intervention. CONCLUSIONS: Among children hospitalized for COVID-19, thromboprophylaxis with twice-daily enoxaparin appears safe and warrants further investigation to assess efficacy.

Retroperitoneal hematoma in COVID-19 patients - case series.

COVID-19 patients, particularly those with severe pulmonary involvement, are at an increased thromboembolic risk related, among various causes, to the cytokine storm and excessive activation of the coagulation cascade and platelets. Different intensity of anticoagulation for them is proposed, mainly with low molecular weight heparins (LMWHs); in a confirmed pulmonary embolism (PE) the therapeutic dose of LMWH is routinely used. Some authors suggest that hemorrhagic complications in COVID-19 patients are rare. At the same time, one can find reports on internal bleeding, including retroperitoneal hematoma (RPH) and other abdominal hematomas. CASE REPORTS: The authors describe 5 cases (3 of those aged more than 80 years) with giant RPHs and with moderate/severe COVID-19 pneumonia, treated before RPH diagnosis with different enoxaparin doses. The therapeutic dose was given to the male with verified PE limited to the segmental/subsegmental pulmonary arteries and initially to the female in whom echocardiography was strongly suggestive of PE, yet this diagnosis was excluded on CT angiography. In one patient, the enoxaparin dose was escalated from 40 mg bd to 60 mg bd after the D-dimer increase. Two patients had bleeding complications despite the enoxaparin dose restricted to 40 mg/daily or bd. Two males had a coexistent psoas hematoma while in only one female there was a coexistent femoral hematoma. RPHs occurred between day 4 and 14 of hospitalization and all were treated conservatively. Three patients who died were particularly charged, so their deaths were not merely directly associated with RPH, which was closely analyzed in one autopsy performed. The authors underline that the choice of anticoagulation intensity in patients with COVID-19 pneumonia without venous thromboembolism seems sometimes difficult but recent publications indicate the low prophylactic enoxaparin dose as an optimal option. Anticoagulation dose escalation based only on the D-dimer level may not be appropriate for certain patients; moreover, the D-dimer increase is commonly observed during internal bleeding.

Supraprophylactic Anti-Factor Xa Levels Are Associated with Major Bleeding in Neurosurgery Patients Receiving Prophylactic Enoxaparin.

BACKGROUND: Prior studies demonstrated reduced risk for venous thromboembolism (VTE) in neurosurgical patients secondary to prophylaxis with both heparin and low-molecular-weight heparin. The ability to monitor low-molecular-weight heparin by obtaining anti-factor Xa (anti-Xa) serum levels provides an opportunity to evaluate safety and efficacy. The aim of this study was to describe characteristics of patients who have anti-Xa levels outside of the goal range (0.2-0.4/0.5 IU/mL) and investigate incidence of major bleeding and VTE. METHODS: A single-center, retrospective, observational study was conducted on neurosurgical patients receiving enoxaparin for VTE prophylaxis between August 2019 and December 2020. Significance testing was conducted via Fisher exact test and independent samples t test. RESULTS: The study included 85 patients. Patients were less likely to have an anti-Xa level in the goal range if they were male, had a higher weight, or were morbidly obese. Three neuroendovascular patients (3.5%) experienced a major bleed. Serum anti-Xa levels were significantly higher in patients who experienced major bleeds compared with patients who did not (0.45 ± 0.16 IU/mL vs. 0.28 ± 0.09 IU/mL, P = 0.003). Patients with a supraprophylactic anti-Xa level (>0.5 IU/mL) were more likely to experience a major bleed (P = 0.005). One VTE event occurred: the patient experienced a pulmonary embolism with anti-Xa level at goal. CONCLUSIONS: Anti-Xa-guided enoxaparin dosing for VTE prophylaxis in neurosurgical patients may help prevent major bleeding. These data suggest that a higher anti-Xa level may predispose patients to major bleeding. Further evaluation is needed to identify the goal anti-Xa level for VTE prophylaxis in this population.

Postoperative fever secondary to enoxaparin usage with pork allergy.

Postoperative fevers are common in hospitalised patients and warrant workup beyond the early post-op period. A 50-year-old man was admitted after sustaining a tibial plateau fracture. Fevers began 3 days after external fixation and persisted through a second surgery despite initial negative workup. Careful review of medications revealed enoxaparin as the instigating agent of a febrile drug reaction, and the fevers resolved after discontinuing the drug. On further questioning, it was discovered the patient had an allergy to pork, from which the main components of enoxaparin are typically derived. To our knowledge, this is the first reported enoxaparin-induced fever in the setting of a pork allergy. Enoxaparin-induced fevers should be considered in patients with unexplained post-op fever. Our case demonstrates the importance of analysing newly administered medications. Simple detailed history may significantly reduce patient morbidity and help to broaden differentials during investigation.

Enoxaparin dose impacts blood cell phenotypes during mild SARS-CoV-2 infection: the observational single-center study.

Coronavirus disease 2019 (COVID-19) is associated with various hemostatic abnormalities requiring constant search for better delicate antithrombotic management in these high-risk patients. The choice and the optimal dose of anticoagulant is important, but unclear, especially for mild COVID-19. Enoxaparin has been tested in several COVID trials with mixed results regarding hard clinical outcomes including mortality. We analyzed clinical, laboratory data and changes in platelets, erythrocytes and leukocytes by scanning electron microscopy on admission and at hospital discharge in patients with confirmed COVID-19 treated with enoxaparin (n = 31) and matched healthy controls (n = 32) in a retrospective observational study. The data were triaged by enoxaparin dose comparing 40 mg/daily prophylactic enoxaparin dose (PED) with 80 mg/daily therapeutic (TED) regimens. All patients experienced mild disease, none required pulmonary support, and all survived. The impact of enoxaparin dose was prominent for platelets and erythrocytes, but less evident for leukocytes. PED was associated with significant platelet activation, diminished numbers of silent nonactive discoid cells, and increased number and size of platelet microaggregates with leukocyte involvement. In contrast, TED did not cause extra platelet activation, while circulating platelet microaggregates were smaller and lacking leukocytes in their construction. PED caused significant increase of erythrocyte-platelet aggregates formation, and numerically higher proportion of circulating echinocytes. TED was associated with significant decrease of rouleaux sludge formation compared to only some trend after PED. Changes in leukocytes were less dependent on enoxaparin dose. However, PED has been associated with enhanced aggregate formation in 7 out of 10 patients, while trap net formation has been decreased in 17 out of 21 TED patients. We conclude that over hospital stay TED was superior to PED in patients with mild COVID-19. The inability of PED to adequately protect major circulating blood cells is probably due to enhanced clearance or/and diminished bioavailability of enoxaparin during COVID. These retrospective observational small sample size data may be relevant to better understanding of the mixed results in controlled outcome-driven trials exploring optimal COVID-19 anticoagulant strategies.

Enoxaparin-induced Wunderlich syndrome in a young patient with anti-GAD 65-associated opsoclonus and limbic encephalitis: a rare complication in a rare disease.

Wunderlich syndrome is a rare condition characterised by acute spontaneous non-traumatic renal haemorrhage into the subcapsular and perirenal spaces. Our case of anti-GAD65-associated autoimmune encephalitis (AE), aged 30 years, developed this complication following use of enoxaparin and was managed by selective glue embolisation of subsegmental branches of right renal cortical arteries. Our case had opsoclonus as one of the clinical manifestations, which has till now been described in only two patients of this AE. This patient received all forms of induction therapies (steroids, plasmapheresis, intravenous immunoglobulin and rituximab) following which she had good improvement in her clinical condition. The good response to immunotherapy is also a point of discussion as this has been rarely associated with anti-GAD65 AE.

Abelacimab for Prevention of Venous Thromboembolism.

BACKGROUND: The role of factor XI in the pathogenesis of postoperative venous thromboembolism is uncertain. Abelacimab is a monoclonal antibody that binds to factor XI and locks it in the zymogen (inactive precursor) conformation. METHODS: In this open-label, parallel-group trial, we randomly assigned 412 patients who were undergoing total knee arthroplasty to receive one of three regimens of abelacimab (30 mg, 75 mg, or 150 mg) administered postoperatively in a single intravenous dose or to receive 40 mg of enoxaparin administered subcutaneously once daily. The primary efficacy outcome was venous thromboembolism, detected by mandatory venography of the leg involved in the operation or objective confirmation of symptomatic events. The principal safety outcome was a composite of major or clinically relevant nonmajor bleeding up to 30 days after surgery. RESULTS: Venous thromboembolism occurred in 13 of 102 patients (13%) in the 30-mg abelacimab group, 5 of 99 patients (5%) in the 75-mg abelacimab group, and 4 of 98 patients (4%) in the 150-mg abelacimab group, as compared with 22 of 101 patients (22%) in the enoxaparin group. The 30-mg abelacimab regimen was noninferior to enoxaparin, and the 75-mg and 150-mg abelacimab regimens were superior to enoxaparin (P<0.001). Bleeding occurred in 2%, 2%, and none of the patients in the 30-mg, 75-mg, and 150-mg abelacimab groups, respectively, and in none of the patients in the enoxaparin group. CONCLUSIONS: This trial showed that factor XI is important for the development of postoperative venous thromboembolism. Factor XI inhibition with a single intravenous dose of abelacimab after total knee arthroplasty was effective for the prevention of venous thromboembolism and was associated with a low risk of bleeding. (Funded by Anthos Therapeutics; ANT-005 TKA EudraCT number, 2019-003756-37.).

Randomized clinical trial to evaluate a routine full anticoagulation Strategy in Patients with Coronavirus Infection (SARS-CoV2) admitted to hospital: Rationale and design of the ACTION (AntiCoagulaTlon cOroNavirus)-Coalition IV trial.

BACKGROUND: Observational studies have suggested a higher risk of thrombotic events in patients with coronavirus disease 2019 (COVID-19). Moreover, elevated D-dimer levels have been identified as an important prognostic marker in COVID-19 directly associated with disease severity and progression. Prophylactic anticoagulation for hospitalized COVID-19 patients might not be enough to prevent thrombotic events; therefore, therapeutic anticoagulation regimens deserve clinical investigation. DESIGN: ACTION is an academic-led, pragmatic, multicenter, open-label, randomized, phase IV clinical trial that aims to enroll around 600 patients at 40 sites participating in the Coalition COVID-19 Brazil initiative. Eligible patients with a confirmed diagnosis of COVID-19 with symptoms up to 14 days and elevated D-dimer levels will be randomized to a strategy of full-dose anticoagulation for 30 days with rivaroxaban 20 mg once daily (or full-dose heparin if oral administration is not feasible) vs standard of care with any approved venous thromboembolism prophylaxis regimen during hospitalization. A confirmation of COVID-19 was mandatory for study entry, based on specific tests used in clinical practice (RT-PCR, antigen test, IgM test) collected before randomization, regardless of in the outpatient setting or not. Randomization will be stratified by clinical stability at presentation. The primary outcome is a hierarchical analysis of mortality, length of hospital stay, or duration of oxygen therapy at the end of 30 days. Secondary outcomes include the World Health Organization's 8-point ordinal scale at 30 days and the following efficacy outcomes: incidence of venous thromboembolism , acute myocardial infarction, stroke, systemic embolism, major adverse limb events, duration of oxygen therapy, disease progression, and biomarkers. The primary safety outcomes are major or clinically relevant non-major bleeding according to the International Society on Thrombosis and Haemostasis criteria. SUMMARY: The ACTION trial will evaluate whether in-hospital therapeutic anticoagulation with rivaroxaban for stable patients, or enoxaparin for unstable patients, followed by rivaroxaban through 30 days compared with standard prophylactic anticoagulation improves clinical outcomes in hospitalized patients with COVID-19 and elevated D-dimer levels.

Standard prophylactic versus intermediate dose enoxaparin in adults with severe COVID-19: A multi-center, open-label, randomized controlled trial.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is associated with coagulopathy but the optimal prophylactic anticoagulation therapy remains uncertain and may depend on COVID-19 severity. OBJECTIVE: To compare outcomes in hospitalized adults with severe COVID-19 treated with standard prophylactic versus intermediate dose enoxaparin. METHODS: We conducted a multi-center, open-label, randomized controlled trial comparing standard prophylactic dose versus intermediate dose enoxaparin in adults who were hospitalized with COVID-19 and admitted to an intensive care unit (ICU) and/or had laboratory evidence of coagulopathy. Patients were randomly assigned in a 1:1 ratio to receive standard prophylactic dose enoxaparin or intermediate weight-adjusted dose enoxaparin. The primary outcome was all-cause mortality at 30 days. Secondary outcomes included arterial or venous thromboembolism and major bleeding. RESULTS: A total of 176 patients (99 males and 77 females) underwent randomization. In the intention-to-treat population, all-cause mortality at 30 days was 15% for intermediate dose enoxaparin and 21% for standard prophylactic dose enoxaparin (odds ratio, 0.66; 95% confidence interval, 0.30-1.45; P = .31 by Chi-square test). Unadjusted Cox proportional hazards modeling demonstrated no significant difference in mortality between intermediate and standard dose enoxaparin (hazard ratio, 0.67; 95% confidence interval, 0.33-1.37; P = .28). Arterial or venous thrombosis occurred in 13% of patients assigned to intermediate dose enoxaparin and 9% of patients assigned to standard dose enoxaparin. Major bleeding occurred in 2% of patients in each arm. CONCLUSION: In hospitalized adults with severe COVID-19, standard prophylactic dose and intermediate dose enoxaparin did not differ significantly in preventing death or thrombosis at 30 days.

Intermediate-Dose versus Standard-Dose Prophylactic Anticoagulation in Patients with COVID-19 Admitted to the Intensive Care Unit: 90-Day Results from the INSPIRATION Randomized Trial.

BACKGROUND: Thrombotic complications are considered among the main extrapulmonary manifestations of coronavirus disease 2019 (COVID-19). The optimal type and duration of prophylactic antithrombotic therapy in these patients remain unknown. METHODS: This article reports the final (90-day) results of the Intermediate versus Standard-dose Prophylactic anticoagulation In cRitically-ill pATIents with COVID-19: An opeN label randomized controlled trial (INSPIRATION) study. Patients with COVID-19 admitted to intensive care were randomized to intermediate-dose versus standard-dose prophylactic anticoagulation for 30 days, irrespective of hospital discharge status. The primary efficacy outcome was a composite of adjudicated venous or arterial thrombosis, treatment with extracorporeal membrane oxygenation (ECMO), or all-cause death. The main safety outcome was major bleeding. RESULTS: Of 600 randomized patients, 562 entered the modified intention-to-treat analysis (median age [Q1, Q3]: 62 [50, 71] years; 237 [42.2%] women), of whom 336 (59.8%) survived to hospital discharge. The primary outcome occurred in 132 (47.8%) of patients assigned to intermediate dose and 130 (45.4%) patients assigned to standard-dose prophylactic anticoagulation (hazard ratio [HR]: 1.21, 95% confidence interval [CI]: 0.95-1.55, p = 0.11). Findings were similar for other efficacy outcomes, and in the landmark analysis from days 31 to 90 (HR: 1.59, 95% CI: 0.45-5.06). There were 7 (2.5%) major bleeding events in the intermediate-dose group (including 3 fatal events) and 4 (1.4%) major bleeding events in the standard-dose group (none fatal) (HR: 1.82, 95% CI: 0.53-6.24). CONCLUSION: Intermediate-dose compared with standard-dose prophylactic anticoagulation did not reduce a composite of death, treatment with ECMO, or venous or arterial thrombosis at 90-day follow-up.

Effect of Intermediate-Dose vs Standard-Dose Prophylactic Anticoagulation on Thrombotic Events, Extracorporeal Membrane Oxygenation Treatment, or Mortality Among Patients With COVID-19 Admitted to the Intensive Care Unit: The INSPIRATION Randomized Clinical Trial.

Importance: Thrombotic events are commonly reported in critically ill patients with COVID-19. Limited data exist to guide the intensity of antithrombotic prophylaxis. Objective: To evaluate the effects of intermediate-dose vs standard-dose prophylactic anticoagulation among patients with COVID-19 admitted to the intensive care unit (ICU). Design, Setting, and Participants: Multicenter randomized trial with a 2 × 2 factorial design performed in 10 academic centers in Iran comparing intermediate-dose vs standard-dose prophylactic anticoagulation (first hypothesis) and statin therapy vs matching placebo (second hypothesis; not reported in this article) among adult patients admitted to the ICU with COVID-19. Patients were recruited between July 29, 2020, and November 19, 2020. The final follow-up date for the 30-day primary outcome was December 19, 2020. Interventions: Intermediate-dose (enoxaparin, 1 mg/kg daily) (n = 276) vs standard prophylactic anticoagulation (enoxaparin, 40 mg daily) (n = 286), with modification according to body weight and creatinine clearance. The assigned treatments were planned to be continued until completion of 30-day follow-up. Main Outcomes and Measures: The primary efficacy outcome was a composite of venous or arterial thrombosis, treatment with extracorporeal membrane oxygenation, or mortality within 30 days, assessed in randomized patients who met the eligibility criteria and received at least 1 dose of the assigned treatment. Prespecified safety outcomes included major bleeding according to the Bleeding Academic Research Consortium (type 3 or 5 definition), powered for noninferiority (a noninferiority margin of 1.8 based on odds ratio), and severe thrombocytopenia (platelet count <20 ×103/µL). All outcomes were blindly adjudicated. Results: Among 600 randomized patients, 562 (93.7%) were included in the primary analysis (median [interquartile range] age, 62 [50-71] years; 237 [42.2%] women). The primary efficacy outcome occurred in 126 patients (45.7%) in the intermediate-dose group and 126 patients (44.1%) in the standard-dose prophylaxis group (absolute risk difference, 1.5% [95% CI, -6.6% to 9.8%]; odds ratio, 1.06 [95% CI, 0.76-1.48]; P = .70). Major bleeding occurred in 7 patients (2.5%) in the intermediate-dose group and 4 patients (1.4%) in the standard-dose prophylaxis group (risk difference, 1.1% [1-sided 97.5% CI, -∞ to 3.4%]; odds ratio, 1.83 [1-sided 97.5% CI, 0.00-5.93]), not meeting the noninferiority criteria (P for noninferiority >.99). Severe thrombocytopenia occurred only in patients assigned to the intermediate-dose group (6 vs 0 patients; risk difference, 2.2% [95% CI, 0.4%-3.8%]; P = .01). Conclusions and Relevance: Among patients admitted to the ICU with COVID-19, intermediate-dose prophylactic anticoagulation, compared with standard-dose prophylactic anticoagulation, did not result in a significant difference in the primary outcome of a composite of adjudicated venous or arterial thrombosis, treatment with extracorporeal membrane oxygenation, or mortality within 30 days. These results do not support the routine empirical use of intermediate-dose prophylactic anticoagulation in unselected patients admitted to the ICU with COVID-19. Trial Registration: ClinicalTrials.gov Identifier: NCT04486508.

Treatment-Dose LMWH versus Prophylactic/Intermediate Dose Heparins in High-Risk COVID-19 Inpatients: Rationale and Design of the HEP-COVID Trial.

Coronavirus disease-2019 (COVID-19) has been associated with significant risk of venous thromboembolism (VTE), arterial thromboembolism (ATE), and mortality particularly among hospitalized patients with critical illness and elevated D-dimer (Dd) levels. Conflicting data have yet to elucidate optimal thromboprophylaxis dosing. HEP-COVID (NCT04401293) is a phase 3, multicenter, pragmatic, prospective, randomized, pseudo-blinded, active control trial to evaluate efficacy and safety of therapeutic-dose low-molecular-weight heparin (LMWH) versus prophylactic-/intermediate-dose LMWH or unfractionated heparin (UFH) for prevention of a primary efficacy composite outcome of VTE, ATE, and all-cause mortality 30 ± 2 days post-enrollment. Eligible patients have COVID-19 diagnosis by nasal swab or serologic testing, requirement for supplemental oxygen per investigator judgment, and Dd >4 × upper limit of normal (ULN) or sepsis-induced coagulopathy score ≥4. Subjects are randomized to enoxaparin 1 mg/kg subcutaneous (SQ)/two times a day (BID) (creatinine clearance [CrCl] ≥ 30 mL/min) or 0.5 mg/kg (CrCl 15-30 mL/min) versus local institutional prophylactic regimens including (1) UFH up to 22,500 IU (international unit) daily (divided BID or three times a day), (2) enoxaparin 30 and 40 mg SQ QD (once daily) or BID, or (3) dalteparin 2,500 IU or 5,000 IU QD. The principal safety outcome is major bleeding. Events are adjudicated locally. Based on expected 40% relative risk reduction with treatment-dose compared with prophylactic-dose prophylaxis, 308 subjects will be enrolled (assuming 20% drop-out) to achieve 80% power. Distinguishing design features include an enriched population for the composite endpoint anchored on Dd >4 × ULN, stratification by intensive care unit (ICU) versus non-ICU, and the ability to capture asymptomatic proximal deep venous thrombosis via screening ultrasonography prior to discharge.

Healthcare disparities among anticoagulation therapies for severe COVID-19 patients in the multi-site VIRUS registry.

Here we analyze hospitalized andintensive care unit coronavirus disease 2019 (COVID-19) patient outcomes from the international VIRUS registry (https://clinicaltrials.gov/ct2/show/NCT04323787). We find that COVID-19 patients administered unfractionated heparin but not enoxaparin have a higher mortality-rate (390 of 1012 = 39%) compared to patients administered enoxaparin but not unfractionated heparin (270 of 1939 = 14%), presenting a risk ratio of 2.79 (95% confidence interval [CI]: [2.42, 3.16]; p = 4.45e-52). This difference persists even after balancing on a number of covariates including demographics, comorbidities, admission diagnoses, and method of oxygenation, with an increased mortality rate on discharge from the hospital of 37% (268 of 733) for unfractionated heparin versus 22% (154 of 711) for enoxaparin, presenting a risk ratio of 1.69 (95% CI: [1.42, 2.00]; p = 1.5e-8). In these balanced cohorts, a number of complications occurred at an elevated rate for patients administered unfractionated heparin compared to patients administered enoxaparin, including acute kidney injury, acute cardiac injury, septic shock, and anemia. Furthermore, a higher percentage of Black/African American COVID patients (414 of 1294 [32%]) were noted to receive unfractionated heparin compared to White/Caucasian COVID patients (671 of 2644 [25%]), risk ratio 1.26 (95% CI: [1.14, 1.40]; p = 7.5e-5). After balancing upon available clinical covariates, this difference in anticoagulant use remained statistically significant (311 of 1047 [30%] for Black/African American vs. 263 of 1047 [25%] for White/Caucasian, p = .02, risk ratio 1.18; 95% CI: [1.03, 1.36]). While retrospective studies cannot suggest any causality, these findings motivate the need for follow-up prospective research into the observed racial disparity in anticoagulant use and outcomes for severe COVID-19 patients.

Clinical outcome with different doses of low-molecular-weight heparin in patients hospitalized for COVID-19.

A pro-thrombotic milieu and a higher risk of thrombotic events were observed in patients with CoronaVirus disease-19 (COVID-19). Accordingly, recent data suggested a beneficial role of low molecular weight heparin (LMWH), but the optimal dosage of this treatment is unknown. We evaluated the association between prophylactic vs. intermediate-to-fully anticoagulant doses of enoxaparin and in-hospital adverse events in patients with COVID-19. We retrospectively included 436 consecutive patients admitted in three Italian hospitals. Outcome according to the use of prophylactic (4000 IU) vs. higher (> 4000 IU) daily dosage of enoxaparin was evaluated. The primary end-point was in-hospital death. Secondary outcome measures were in-hospital cardiovascular death, venous thromboembolism, new-onset acute respiratory distress syndrome (ARDS) and mechanical ventilation. A total of 287 patients (65.8%) were treated with the prophylactic enoxaparin regimen and 149 (34.2%) with a higher dosing regimen. The use of prophylactic enoxaparin dose was associated with a similar incidence of all-cause mortality (25.4% vs. 26.9% with the higher dose; OR at multivariable analysis, including the propensity score: 0.847, 95% CI 0.400-0.1.792; p = 0.664). In the prophylactic dose group, a significantly lower incidence of cardiovascular death (OR 0.165), venous thromboembolism (OR 0.067), new-onset ARDS (OR 0.454) and mechanical intubation (OR 0.150) was observed. In patients hospitalized for COVID-19, the use of a prophylactic dosage of enoxaparin appears to be associated with similar in-hospital overall mortality compared to higher doses. These findings require confirmation in a randomized, controlled study.