Predictors of bleeding and thrombotic events among patients admitted to the hospital with COVID-19 and elevated D-dimer: insights from the ACTION randomized clinical trial.

Therapeutic anticoagulation showed inconsistent results in hospitalized patients with COVID-19 and selection of the best patients to use this strategy still a challenge balancing the risk of thrombotic and hemorrhagic outcomes. The present post-hoc analysis of the ACTION trial evaluated the variables independently associated with both bleeding events (major bleeding or clinically relevant non-major bleeding) and the composite outcomes thrombotic events (venous thromboembolism, myocardial infarction, stroke, systemic embolism, or major adverse limb events). Variables were assessed one by one with independent logistic regressions and final models were chosen based on Akaike information criteria. The model for bleeding events showed an area under the curve of 0.63 (95% confidence interval [CI] 0.53 to 0.73), while the model for thrombotic events had an area under the curve of 0.72 (95% CI 0.65 to 0.79). Non-invasive respiratory support was associated with thrombotic but not bleeding events, while invasive ventilation was associated with both outcomes (Odds Ratio of 7.03 [95 CI% 1.95 to 25.18] for thrombotic and 3.14 [95% CI 1.11 to 8.84] for bleeding events). Beyond respiratory support, creatinine level (Odds Ratio [OR] 1.01 95% CI 1.00 to 1.02 for every 1.0 mg/dL) and history of coronary disease (OR 3.67; 95% CI 1.32 to 10.29) were also independently associated to the risk of thrombotic events. Non-invasive respiratory support, history of coronary disease, and creatinine level may help to identify hospitalized COVID-19 patients at higher risk of thrombotic complications.ClinicalTrials.gov: NCT04394377.

Rivaroxaban versus no anticoagulation for post-discharge thromboprophylaxis after hospitalisation for COVID-19 (MICHELLE): an open-label, multicentre, randomised, controlled trial.

BACKGROUND: Patients hospitalised with COVID-19 are at risk for thrombotic events after discharge; the role of extended thromboprophylaxis in this population is unknown. METHODS: In this open-label, multicentre, randomised trial conducted at 14 centres in Brazil, patients hospitalised with COVID-19 at increased risk for venous thromboembolism (International Medical Prevention Registry on Venous Thromboembolism [IMPROVE] venous thromboembolism [VTE] score of ≥4 or 2-3 with a D-dimer >500 ng/mL) were randomly assigned (1:1) to receive, at hospital discharge, rivaroxaban 10 mg/day or no anticoagulation for 35 days. The primary efficacy outcome in an intention-to-treat analysis was a composite of symptomatic or fatal venous thromboembolism, asymptomatic venous thromboembolism on bilateral lower-limb venous ultrasound and CT pulmonary angiogram, symptomatic arterial thromboembolism, and cardiovascular death at day 35. Adjudication was blinded. The primary safety outcome was major bleeding. The primary and safety analyses were carried out in the intention-to-treat population. This trial is registered at ClinicalTrials.gov, NCT04662684. FINDINGS: From Oct 8, 2020, to June 29, 2021, 997 patients were screened. Of these patients, 677 did not meet eligibility criteria; the remaining 320 patients were enrolled and randomly assigned to receive rivaroxaban (n=160 [50%]) or no anticoagulation (n=160 [50%]). All patients received thromboprophylaxis with standard doses of heparin during hospitalisation. 165 (52%) patients were in the intensive care unit while hospitalised. 197 (62%) patients had an IMPROVE score of 2-3 and elevated D-dimer levels and 121 (38%) had a score of 4 or more. Two patients (one in each group) were lost to follow-up due to withdrawal of consent and not included in the intention-to-treat primary analysis. The primary efficacy outcome occurred in five (3%) of 159 patients assigned to rivaroxaban and 15 (9%) of 159 patients assigned to no anticoagulation (relative risk 0·33, 95% CI 0·12-0·90; p=0·0293). No major bleeding occurred in either study group. Allergic reactions occurred in two (1%) patients in the rivaroxaban group. INTERPRETATION: In patients at high risk discharged after hospitalisation due to COVID-19, thromboprophylaxis with rivaroxaban 10 mg/day for 35 days improved clinical outcomes compared with no extended thromboprophylaxis. FUNDING: Bayer.

Therapeutic versus prophylactic anticoagulation for patients admitted to hospital with COVID-19 and elevated D-dimer concentration (ACTION): an open-label, multicentre, randomised, controlled trial.

BACKGROUND: COVID-19 is associated with a prothrombotic state leading to adverse clinical outcomes. Whether therapeutic anticoagulation improves outcomes in patients hospitalised with COVID-19 is unknown. We aimed to compare the efficacy and safety of therapeutic versus prophylactic anticoagulation in this population. METHODS: We did a pragmatic, open-label (with blinded adjudication), multicentre, randomised, controlled trial, at 31 sites in Brazil. Patients (aged ≥18 years) hospitalised with COVID-19 and elevated D-dimer concentration, and who had COVID-19 symptoms for up to 14 days before randomisation, were randomly assigned (1:1) to receive either therapeutic or prophylactic anticoagulation. Therapeutic anticoagulation was in-hospital oral rivaroxaban (20 mg or 15 mg daily) for stable patients, or initial subcutaneous enoxaparin (1 mg/kg twice per day) or intravenous unfractionated heparin (to achieve a 0·3-0·7 IU/mL anti-Xa concentration) for clinically unstable patients, followed by rivaroxaban to day 30. Prophylactic anticoagulation was standard in-hospital enoxaparin or unfractionated heparin. The primary efficacy outcome was a hierarchical analysis of time to death, duration of hospitalisation, or duration of supplemental oxygen to day 30, analysed with the win ratio method (a ratio >1 reflects a better outcome in the therapeutic anticoagulation group) in the intention-to-treat population. The primary safety outcome was major or clinically relevant non-major bleeding through 30 days. This study is registered with ClinicalTrials.gov (NCT04394377) and is completed. FINDINGS: From June 24, 2020, to Feb 26, 2021, 3331 patients were screened and 615 were randomly allocated (311 [50%] to the therapeutic anticoagulation group and 304 [50%] to the prophylactic anticoagulation group). 576 (94%) were clinically stable and 39 (6%) clinically unstable. One patient, in the therapeutic group, was lost to follow-up because of withdrawal of consent and was not included in the primary analysis. The primary efficacy outcome was not different between patients assigned therapeutic or prophylactic anticoagulation, with 28 899 (34·8%) wins in the therapeutic group and 34 288 (41·3%) in the prophylactic group (win ratio 0·86 [95% CI 0·59-1·22], p=0·40). Consistent results were seen in clinically stable and clinically unstable patients. The primary safety outcome of major or clinically relevant non-major bleeding occurred in 26 (8%) patients assigned therapeutic anticoagulation and seven (2%) assigned prophylactic anticoagulation (relative risk 3·64 [95% CI 1·61-8·27], p=0·0010). Allergic reaction to the study medication occurred in two (1%) patients in the therapeutic anticoagulation group and three (1%) in the prophylactic anticoagulation group. INTERPRETATION: In patients hospitalised with COVID-19 and elevated D-dimer concentration, in-hospital therapeutic anticoagulation with rivaroxaban or enoxaparin followed by rivaroxaban to day 30 did not improve clinical outcomes and increased bleeding compared with prophylactic anticoagulation. Therefore, use of therapeutic-dose rivaroxaban, and other direct oral anticoagulants, should be avoided in these patients in the absence of an evidence-based indication for oral anticoagulation. FUNDING: Coalition COVID-19 Brazil, Bayer SA.

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.

Medically Ill hospitalized Patients for COVID-19 THrombosis Extended ProphyLaxis with rivaroxaban ThErapy: Rationale and Design of the MICHELLE Trial.

BACKGROUND: The devastating Coronavirus disease (COVID-19) pandemic is associated with a high prothrombotic state. It is unclear if the coagulation abnormalities occur because of the direct effect of SARS-CoV-2 or indirectly by the cytokine storm and endothelial damage or by a combination of mechanisms. There is a clear indication of in-hospital pharmacological thromboprophylaxis for every patient with COVID-19 after bleed risk assessment. However, there is much debate regarding the best dosage regimen, and there is no consensus on the role of extended thromboprophylaxis. DESIGN: This study aims to evaluate the safety and efficacy of rivaroxaban 10 mg once daily for 35 ± 4 days versus no intervention after hospital discharge in COVID-19 patients who were at increased risk for VTE and have received standard parenteral VTE prophylaxis during hospitalization. The composite efficacy endpoint is a combination of symptomatic VTE, VTE-related death, VTE detected by bilateral lower limbs venous duplex scan and computed tomography pulmonary angiogram on day 35 ± 4 posthospital discharge and symptomatic arterial thromboembolism (myocardial infarction, nonhemorrhagic stroke, major adverse limb events, and cardiovascular death) up to day 35 ± 4 posthospital discharge. The key safety outcome is the incidence of major bleeding according to ISTH criteria. SUMMARY: The MICHELLE trial is expected to provide high-quality evidence around the role of extended thromboprophylaxis in COVID-19 and will help guide medical decisions in clinical practice.1.

Rationale and design for the study Apixaban versus ClopidoGRel on a background of aspirin in patient undergoing InfraPoPliteal angioplasty for critical limb ischemia: AGRIPPA trial.

BACKGROUND: New antithrombotic strategies that reduce primary thrombosis and restenosis might improve vascular outcomes in patients with peripheral artery disease (PAD) undergoing arterial angioplasty. The study objective is to evaluate the potential benefit of apixaban plus aspirin compared with standard of care dual antiplatelet therapy (DAPT) in reducing thrombotic restenosis and artery re-occlusion in patients undergoing endovascular infrapopliteal revascularization. STUDY DESIGN: This multicenter, parallel-group, prospective, randomized, open-label, blinded-endpoint adjudication, proof-of-concept, exploratory trial aims to randomize 200 patients 72 hours after successful infrapopliteal angioplasty for critical limb ischemia (CLI). Patients will be randomly assigned in a 1:1 ratio to receive oral apixaban (2.5 mg twice daily) plus aspirin (100 mg once daily) for 12 months or clopidogrel (75 mg daily) for at least 3 months on a background of aspirin (100 mg once daily) for 12 months. The primary endpoint is the composite of target lesion revascularization (TLR), major amputation, or restenosis/occlusion (RAS) in addition to major adverse cardiovascular events - MACE (myocardial infarction, stroke or cardiovascular death) at 12 months. The primary safety endpoint is the composite of major bleeding or clinically relevant non-major bleeding at 12 months. SUMMARY: This study will evaluate the efficacy and safety of apixaban 2.5 mg twice daily plus aspirin compared with DAPT (clopidogrel plus aspirin) in patients with CLI undergoing endovascular infrapopliteal revascularization and might prove the concept of an alternative antithrombotic regimen for these patients to be tested in a future large randomized clinical trial.

Apixaban Versus Warfarin for Mechanical Heart Valve Thromboprophylaxis in a Swine Aortic Heterotopic Valve Model.

OBJECTIVE: Warfarin is the current standard for oral anticoagulation therapy in patients with mechanical heart valves, yet optimal therapy to maximize anticoagulation and minimize bleeding complications requires routine coagulation monitoring, possible dietary restrictions, and drug interaction monitoring. As alternatives to warfarin, oral direct acting factor Xa inhibitors are currently approved for the prophylaxis and treatment of venous thromboembolism and reduction of stroke and systemic embolization. However, no in vivo preclinical or clinical studies have been performed directly comparing oral factor Xa inhibitors such as apixaban to warfarin, the current standard of therapy. APPROACH AND RESULTS: A well-documented heterotopic aortic valve porcine model was used to test the hypothesis that apixaban has comparable efficacy to warfarin for thromboprophylaxis of mechanical heart valves. Sixteen swine were implanted with a bileaflet mechanical aortic valve that bypassed the ligated descending thoracic aorta. Animals were randomized to 4 groups: control (no anticoagulation; n=4), apixaban oral 1 mg/kg twice a day (n=5), warfarin oral 0.04 to 0.08 mg/kg daily (international normalized ratio 2-3; n=3), and apixaban infusion (n=4). Postmortem valve thrombus was measured 30 days post-surgery for control-oral groups and 14 days post-surgery for the apixaban infusion group. Control thrombus weight (mean) was significantly different (1422.9 mg) compared with apixaban oral (357.5 mg), warfarin (247.1 mg), and apixiban 14-day infusion (61.1 mg; P<0.05). CONCLUSIONS: Apixaban is a promising candidate and may be a useful alternative to warfarin for thromboprophylaxis of mechanical heart valves. Unlike warfarin, no adverse bleeding events were observed in any apixaban groups.

Warfarin Discontinuation in Patients With Unprovoked Venous Thromboembolism: A Large US Insurance Database Analysis.

This study examined warfarin therapy discontinuation and its risk factors among patients with unprovoked venous thromboembolism (VTE) in the US clinical practice setting. Adult patients with unprovoked VTE were identified from the MarketScan claims database from January 1, 2006 to December 31, 2012. The index date was defined as the date of first VTE diagnosis. Patients were required to have no VTE diagnosis in the 6 months before index date and continuous health plan enrollment for 6 months before and 12 months after the index date. Warfarin discontinuation rates and adjusted hazard ratios (HRs) were reported. Of 21,163 eligible patients, 15,463 were diagnosed with deep vein thrombosis (DVT) only (73.1%), 5027 with pulmonary embolism (PE) only (23.7%), and 673 with DVT and PE (3.2%). The average duration of warfarin therapy was 5.2 months (SD = 3.0). During 1-year follow-up, 21.4% patients discontinued therapy within 3 months, 42.8% within 6 months, and 70.1% within 12 months. PE versus DVT [HR = 0.77, 95% confidence interval (CI) = 0.74-0.80], comorbid atrial fibrillation (HR = 0.73, 95% CI = 0.66-0.81), thrombophilia (HR = 0.62, 95% CI = 0.54-0.71), and age >40 years (41-65 years: HR = 0.86, 95% CI = 0.81-0.91; >65 years: HR = 0.82, 95% CI = 0.77-0.87) were significantly associated with reduced risk of warfarin discontinuation. Alcohol abuse/dependence (HR = 1.36, 95% CI = 1.20-1.55), cancer history (HR = 1.13, 95% CI = 1.07-1.19), bleeding (HR = 1.07, 95% CI = 1.01-1.15), and catheter ablation (HR = 1.10, 95% CI = 1.00-1.20) in the 6 months before index date were significantly associated with increased risk for warfarin discontinuation. In conclusion, nearly 1 of 4 patients with unprovoked VTE discontinued warfarin within 3 months. Three of 4 patients discontinued therapy within 1 year. Younger age and multiple clinical factors are associated with warfarin therapy discontinuation.

Pharmacological Prophylaxis for Venous Thromboembolism Among Hospitalized Patients With Acute Medical Illness: An Electronic Medical Records Study.

Patients hospitalized with acute medical illness have an elevated risk of venous thromboembolism (VTE). American College of Chest Physicians guidelines list various chronic illnesses, sepsis, advanced age, history of VTE, and immobility as risk factors and recommend prophylactic anticoagulation using fondaparinux, low-molecular weight heparin, or low-dose unfractionated heparin. The objectives of this study were to examine pharmacological prophylaxis against VTE among hospitalized medically ill patients and to assess demographic and clinical correlates related to VTE prophylaxis. A retrospective (1999-2010) electronic medical records study included patients aged 40 years and older hospitalized for at least 3 days, with significant medical illness or with a VTE hospitalization 30-365 days before admission. Each patient's first qualifying hospitalization was analyzed. Exclusions were if VTE treatment was started within 1 day of admission, or if warfarin (and not heparin or enoxaparin) was used. Prophylaxis was defined if the first inpatient dose of subcutaneous heparin or enoxaparin was at prophylaxis levels (lower than treatment levels). Multivariable logistic regression was used to examine factors associated with VTE prophylaxis. Among 12,980 patients, 22.1% received prophylaxis (11.8% with enoxaparin, 10.3% with heparin). VTE prophylaxis was positively associated with year of hospitalization, subcutaneous heparin in the month before admission, aspirin, self-pay status, age, and sepsis. VTE prophylaxis was negatively associated with smoking, alcohol, warfarin in the past 30 days, and primary diagnoses of stroke, infectious disease, or inflammatory bowel disease. Pharmacological VTE prophylaxis has increased significantly over the past 12 years but is still largely underused in patients hospitalized with acute medical illness. Multiple demographic, behavioral, and clinical factors are associated with inpatient VTE prophylaxis.

Andexanet Alfa Neutralizes the Anticoagulant Effects of Unfractionated Heparin of Bovine, Ovine and Porcine Origin Almost as Protamine Sulfate.

INTRODUCTION: Andexanet alfa (AA) - zhzo, recombinant coagulation factor Xa, is an approved antidote for oral Xa inhibitors (apixaban and rivaroxaban). Unfractionated heparin (UFH) is commonly used for therapeutic, interventional, and surgical indications. Protamine sulfate (PrSO4) is frequently used to neutralize UFH. This study aimed to investigate the comparative neutralization profiles of AA and PrSO4 for heparins of bovine, ovine, and porcine origin. MATERIALS AND METHODS: The neutralization effect of PrSO4 at 25 µg/ml and AA at 100 µg/ml was studied on an approximate surgical/interventional concentration of heparin by supplementing whole blood with each of the heparins at 25 µg/ml. For the clotting profile (activated partial thromboplastin time: aPTT), amidolytic (anti-Xa and anti-IIa), and thrombin generation assay each of the heparin were supplemented from -10-0.62 µg/ml. RESULTS: In the whole blood ACT studies, all three heparins produced strong anti-coagulant effects (400-450 seconds) compared to saline (130-150 seconds). Both AA and PrSO4 almost fully neutralized the anti-coagulant effects of heparins (140-160 seconds). Both antidotes completely reversed the anticoagulant effects of all three heparins in the aPTT and thrombin generation assay. However, PrSO4 was more effective in neutralizing the anti-Xa, and anti-IIa effects than AA, which only partially neutralized these effects. CONCLUSION: Andexanet alfa at 100 µg/ml effectively neutralizes the therapeutic and surgical/interventional concentrations of heparins in in-vitro settings. While differences in the anti-Xa, and anti-IIa effects between heparins were noted, anti-coagulant effect of these agents in the aPTT assay were comparable. A similar neutralization profile was observed in the ACT and thrombin generation assays by both agents.

Rivaroxaban for Patients with Intermittent Claudication.

BACKGROUND: The combination of rivaroxaban plus aspirin compared with aspirin alone reduces the risk of major adverse cardiovascular and limb events for high-risk patients with peripheral artery disease. It is unknown whether rivaroxaban plus aspirin improves intermittent claudication for adults with lower-risk peripheral arterial disease. METHODS: In this randomized, open-label, multicenter, 24-week clinical trial, we randomly assigned patients with peripheral artery disease and intermittent claudication to receive either 2.5 mg of rivaroxaban twice daily plus 100 mg of aspirin once daily or 100 mg of aspirin once daily. The primary outcome was a 24-week change in total walking distance, measured by the 6-minute walking test. The primary safety outcome was the incidence of major bleeding or clinically relevant nonmajor bleeding. RESULTS: Eighty-eight patients were randomly assigned to either rivaroxaban plus aspirin (n=46) or aspirin alone (n=42). The mean age was 67 years, and 54% were female. The total walking distance measured by 6-minute walk test improved by 89 ± 18 m (mean±standard error) in the rivaroxaban-plus-aspirin group versus 21 ± 16 m in the aspirin-alone group. This corresponded to an absolute difference of 68 ± 24 m (95% confidence interval [CI], 19 to 116 m; P=0.007) and a relative improvement over the aspirin-alone group of 327% (95% CI, 94 to 560%). No major bleeding events were observed in either group. CONCLUSIONS: In patients with peripheral artery disease and intermittent claudication, 2.5 mg of rivaroxaban twice daily plus 100 mg of aspirin daily improved the total walking distance by a 6-minute walking test compared with 100 mg of aspirin daily alone. (Funded by Bayer S.A.; Clinicaltrials.gov number, NCT04853719.).

Biomarkers Profile in Provoked Versus Unprovoked Deep Venous Thrombosis.

Venous thromboembolism (VTE), including deep venous thrombosis (DVT) and pulmonary embolism (PE), represents a substantial healthcare challenge. Provoked and unprovoked DVT cases carry distinct risks and treatment considerations. Recognizing the limitations of this classification, molecular markers may enhance diagnostic precision and guide anticoagulation therapy duration relying on patient history and risk factors. This preliminary, open-label, prospective cohort study was conducted including 15 patients (10 provoked DVT and 5 unprovoked DVT) and a control group of healthy plasmatic subjects. Plasma levels of 9 biomarkers were measured at diagnosis (baseline, day 0, and D0) and after 30 days (day 30-D30). Patient demographics, clinical data, and biomarker concentrations were analyzed. Serum concentrations of D-dimer, von Willebrand factor, C-reactive protein, and Anti-Xa were elevated in DVT groups at D0 compared to controls. No significant differences were observed between the provoked and unprovoked groups on the day of diagnosis and 30 days later. Over 30 days, the provoked group exhibited significant biomarker changes related to temporal assessment. No significant differences were noted in the biomarker profile between provoked and unprovoked DVT groups. This study is indicative of the concept of individualized thrombosis assessment and subsequent treatment for VTE. Larger cohorts are warranted to validate these findings and further define the most appropriate use of the molecular markers.

2023 ISTH update of the 2022 ISTH guidelines for antithrombotic treatment in COVID-19.

Based on emerging evidence from the COVID-19 pandemic, the International Society on Thrombosis and Haemostasis (ISTH) guidelines for antithrombotic treatment in COVID-19 were published in 2022. Since then, at least 16 new randomized controlled trials have contributed additional evidence, which necessitated a modification of most of the previous recommendations. We used again the American College of Cardiology Foundation/American Heart Association methodology for assessment of level of evidence (LOE) and class of recommendation (COR). Five recommendations had the LOE upgraded to A and 2 new recommendations on antithrombotic treatment for patients with COVID-19 were added. Furthermore, a section was added to answer questions about COVID-19 vaccination and vaccine-induced immune thrombotic thrombocytopenia (VITT), for which studies have provided some evidence. We only included recommendations with LOE A or B. Panelists agreed on 19 recommendations, 4 for nonhospitalized, 5 for noncritically ill hospitalized, 3 for critically ill hospitalized, and 2 for postdischarge patients, as well as 5 for vaccination and VITT. A strong recommendation (COR 1) was given for (a) use of prophylactic dose of low-molecular-weight heparin or unfractionated heparin in noncritically ill patients hospitalized for COVID-19, (b) for select patients in this group, use of therapeutic-dose low-molecular-weight heparin/unfractionated heparin in preference to prophylactic dose, and (c) for use of antiplatelet factor 4 enzyme immunoassays for diagnosing VITT. A strong recommendation was given against (COR 3) the addition of an antiplatelet agent in hospitalized, noncritically ill patients. These international guidelines provide recommendations for countries with diverse healthcare resources and COVID-19 vaccine availability.

Primary results of the brazilian registry of atherothrombotic disease (NEAT).

There is limited contemporary prospective real-world evidence of patients with chronic arterial disease in Latin America. The Network to control atherothrombosis (NEAT) registry is a national prospective observational study of patients with known coronary (CAD) and/or peripheral arterial disease (PAD) in Brazil. A total of 2,005 patients were enrolled among 25 sites from September 2020 to March 2022. Patient characteristics, medications and laboratorial data were collected. Primary objective was to assess the proportion of patients who, at the initial visit, were in accordance with good medical practices (domains) for reducing cardiovascular risk in atherothrombotic disease. From the total of patients enrolled, 2 were excluded since they did not meet eligibility criteria. Among the 2,003 subjects included in the analysis, 55.6% had isolated CAD, 28.7% exclusive PAD and 15.7% had both diagnoses. Overall mean age was 66.3 (± 10.5) years and 65.7% were male patients. Regarding evidence-based therapies (EBTs), 4% were not using any antithrombotic drug and only 1.5% were using vascular dose of rivaroxaban (2.5 mg bid). Only 0.3% of the patients satisfied all the domains of secondary prevention, including prescription of EBTs and targets of body-mass index, blood pressure, LDL-cholesterol, and adherence of lifestyle recommendations. The main barrier for prescription of EBTs was medical judgement. Our findings highlight that the contemporary practice does not reflect a comprehensive approach for secondary prevention and had very low incorporation of new therapies in Brazil. Large-scale populational interventions addressing these gaps are warranted to improve the use of evidence-based therapies and reduce the burden of atherothrombotic disease.ClinicalTrials.gov NCT04677725.

Venous thromboembolism prophylaxis and clinical consequences in medically ill patients.

The objective of this study was to examine venous thromboembolism (VTE) prophylaxis use, risk reduction, and readmission in medically ill patients during hospitalization and after discharge. This 5-year retrospective study linked outpatient files from MarketScan Commercial and Medicare Supplemental databases. Patients were categorized into prophylaxis and non-prophylaxis groups based on guideline-recommended anticoagulant use from the index date to 180 days posthospital discharge and before the first VTE event date. Outcome variables were VTE events and rehospitalization. Risk adjustment was conducted within the prophylaxis group and between the prophylaxis and non-prophylaxis groups using propensity score matching. Among 4467 patients, 28.99% of the patients (n = 1295) were admitted with cancer, 18.03% (n = 805) with pneumonia, 14.06% (n = 628) with heart failure, 11.06% (n = 494) with stroke, 11.11% (n = 496) with sepsis, 8.08% (n = 361) with infectious diseases, 5.6% (n = 250) with severe respiratory disorders, 1.81% (n = 81) with inflammatory bowel disease, 1.05% (n = 47) with obesity, 0.20% (n = 9) with neurologic disorders, and 0.02% (n = 1) with acute rheumatic fever. Among those with 180-day continuous enrollment after the index date (n = 3511), 51.81% (n = 1819) received anticoagulant therapy only, 2.48% (n = 87) received mechanical compression treatment only (stocking or pneumatic compression), and 4.41% (n = 155) received both during hospitalization. Anticoagulant therapy rates ranged from 88.64% (obesity) to 32.39% (inflammatory bowel disease). Among anticoagulant therapy patients, 740 patients (40.68%) received low-molecular weight heparin only and 806 patients (44.31%) received unfractionated heparin. After risk adjustment, compared with patients without VTE prophylaxis, anticoagulant prophylaxis patients had lower VTE (3.62% vs. 4.27%, P < 0.04) and readmission rates (24.22% vs. 27.95%, P < 0.02) during the 6 months post-index hospital admission. In conclusion anticoagulant prophylaxis is underutilized and is associated with reduced VTE risk and a decrease in rehospitalizations for medically ill patients.

A novel therapeutic vaccine targeting the soluble TNFα receptor II to limit the progression of cardiovascular disease: AtheroVax™.

The burden of atherosclerotic cardiovascular disease contributes to a large proportion of morbidity and mortality, globally. Vaccination against atherosclerosis has been proposed for over 20 years targeting different mediators of atherothrombosis; however, these have not been adequately evaluated in human clinical trials to assess safety and efficacy. Inflammation is a driver of atherosclerosis, but inflammatory mediators are essential components of the immune response. Only pathogenic forms of sTNFR2 are acted upon while preserving the membrane-bound (wild-type) TNFR2 contributions to a non-pathogenic immune response. We hypothesize that the inhibition of sTNRF2 will be more specific and offer long-term treatment options. Here we describe pre-clinical findings of an sTNFR2-targeting peptide vaccine (AtheroVax™) in a mouse model. The multiple pathways to synthesis of the soluble TNFRII receptor (sTNFRII) were identified as sTNFRII(PC), sTNFRII(Δ7), and sTNFRII(Δ7,9). The sTNFRII(Δ7) peptide, NH2-DFALPVEKPLCLQR-COOH is specific to sTNFR2 based on an mRNA splice-variant in which exon 6 is joined to exon 8. The role of sTNFRII(Δ7) as a mediator of prolonged TNFα activity by preventing degradation and clearance was investigated. Inflammation is a critical driver of onset, progression and expansion of atherosclerosis. The TNFα ligand represents a driver of inflammation that is mediated by a splice variant of TNFR2, referred to as sTNFRII(Δ7). The multiple forms of TNFRII, both membrane bound and soluble, are associated with distinctly different phenotypes. sTNFRII(PC) and sTNFRII(Δ7) are not equivalent to etanercept because they lack a clearance mechanism. The unique peptide associated with sTNFRII(Δ7) contains a linear B-cell epitope with amino acids from both exon 6 and exon 8 supporting the vaccine design. Animal studies to evaluate the vaccine are ongoing, and results will be forthcoming. We describe a peptide vaccine targeting sTNFR2 in limiting the progression of atherosclerosis. A therapeutic vaccine limiting the progression of atherosclerosis will greatly contribute to the reduction in morbidity and mortality from cardiovascular disease. It is likely the vaccine will be used in combination with the current standards of care and lifestyle modifications.

Effects of long-pulsed 1064-nm Nd:YAG laser on telangiectasias and reticular veins: a human in-vivo histological study.

BACKGROUND: Telangiectasias and reticular veins are associated with aesthetic disorders. Sclerotherapy is the gold standard treatment, but long-pulsed 1064-nm Nd:YAG laser (LP1064 laser) is also used. No data on the human histological effects of these lasers are reported. The objective was to test different LP1064 laser parameters and their histological effects on the dermis, collagen, telangiectasias, and reticular veins. METHODS: This was a single-center, prospective, single-arm, case-control, human study. During surgery (dermolipectomy), the abdominal section of 10 female patients was irradiated with 6 different transdermal LP1064 laser parameters after anesthesia. Ten pieces with areas of varying irradiation were evaluated according to the characteristics of the vessels identified by area. In each piece, two irradiation areas were performed per group, totaling 12 irradiation areas per piece, with 120 regions later analyzed at the end of the ten samples. After removing the surgical product, histological sections were extracted, and the dermis, telangiectasias, and reticular veins were analyzed. RESULTS: Histological analysis showed that exposition to six different parameters from LP1064 laser led to significant dermal layer separation and collagen alterations. The effects were inconsistent on the loss of endothelial cells, intravascular thrombus formation, and fusion of vascular walls for both telangiectasias and reticular veins. In reticular veins, effects on intravascular thrombus formation and vascular wall fusion were not observed. CONCLUSIONS: The LP1064 laser in monotherapy with fixed settings did not lead to a consistent vascular lesion to promote immediate occlusion in telangiectasias and reticular veins. This strategy may not work as monotherapy for small vein treatment, but the possible late response to the LP1064 laser cannot be ruled out and require further investigation.

Cost-effectiveness analysis of extended thromboprophylaxis with rivaroxaban versus no prophylaxis in high-risk patients after hospitalisation for COVID-19: an economic modelling study.

Background: In patients at high risk of thromboembolism who were discharged after hospitalisation due to COVID-19, thromboprophylaxis with rivaroxaban 10 mg/day for 35 days significantly improved clinical outcomes, reducing thrombotic events compared with no post-discharge anticoagulation. The present study aimed to estimate the cost-effectiveness of this anticoagulation strategy. Methods: Using the database of the MICHELLE trial, we developed a decision tree to estimate the cost-effectiveness of thromboprophylaxis with rivaroxaban 10 mg/day for 35 days versus no thromboprophylaxis in high-risk post-discharge patients for COVID-19 through an incremental cost-effectiveness analysis. Findings: 318 patients in 14 centres in Brazil were enrolled in the primary MICHELLE trial. The mean age was 57.1 years (SD 15.2), 127 (40%) were women, 191 (60%) were men, and the mean body-mass index was 29.7 kg/m2 (SD 5.6). Rivaroxaban 10 mg per day orally for 35 days after discharge decreased the risk of events defined by the primary efficacy outcome by 67% (relative risk 0.33, 95% CI 0.12-0.90; p = 0.03). The mean cost for thromboprophylaxis with rivaroxaban was $53.37/patient, and no prophylaxis was $34.22/patient, with an incremental cost difference of $19.15. The effectiveness means obtained in the intervention group was 0.1457, while in the control group was 0.1421, determining an incremental QALY difference of 0.0036. The estimated incremental cost-effectiveness ratio (ICER) was $5385.52/QALY. Interpretation: Extended treatment with Rivaroxaban as thromboprophylaxis after hospital discharge for high-risk patients with COVID-19 is a cost-effective treatment option. Funding: Modest funding was provided by Science Valley Research Institute, São Paulo, Brazil.