Synthesis of bioengineered heparin chemically and biologically similar to porcine-derived products and convertible to low MW heparin.

Heparins have been invaluable therapeutic anticoagulant polysaccharides for over a century, whether used as unfractionated heparin or as low molecular weight heparin (LMWH) derivatives. However, heparin production by extraction from animal tissues presents multiple challenges, including the risk of adulteration, contamination, prion and viral impurities, limited supply, insecure supply chain, and significant batch-to-batch variability. The use of animal-derived heparin also raises ethical and religious concerns, as well as carries the risk of transmitting zoonotic diseases. Chemoenzymatic synthesis of animal-free heparin products would offer several advantages, including reliable and scalable production processes, improved purity and consistency, and the ability to produce heparin polysaccharides with molecular weight, structural, and functional properties equivalent to those of the United States Pharmacopeia (USP) heparin, currently only sourced from porcine intestinal mucosa. We report a scalable process for the production of bioengineered heparin that is biologically and compositionally similar to USP heparin. This process relies on enzymes from the heparin biosynthetic pathway, immobilized on an inert support and requires a tailored N-sulfoheparosan with N-sulfo levels similar to those of porcine heparins. We also report the conversion of our bioengineered heparin into a LMWH that is biologically and compositionally similar to USP enoxaparin. Ultimately, we demonstrate major advances to a process to provide a potential clinical and sustainable alternative to porcine-derived heparin products.

Aspirin or Low-Molecular-Weight Heparin for Thromboprophylaxis after a Fracture.

BACKGROUND: Clinical guidelines recommend low-molecular-weight heparin for thromboprophylaxis in patients with fractures, but trials of its effectiveness as compared with aspirin are lacking. METHODS: In this pragmatic, multicenter, randomized, noninferiority trial, we enrolled patients 18 years of age or older who had a fracture of an extremity (anywhere from hip to midfoot or shoulder to wrist) that had been treated operatively or who had any pelvic or acetabular fracture. Patients were randomly assigned to receive low-molecular-weight heparin (enoxaparin) at a dose of 30 mg twice daily or aspirin at a dose of 81 mg twice daily while they were in the hospital. After hospital discharge, the patients continued to receive thromboprophylaxis according to the clinical protocols of each hospital. The primary outcome was death from any cause at 90 days. Secondary outcomes were nonfatal pulmonary embolism, deep-vein thrombosis, and bleeding complications. RESULTS: A total of 12,211 patients were randomly assigned to receive aspirin (6101 patients) or low-molecular-weight heparin (6110 patients). Patients had a mean (±SD) age of 44.6±17.8 years, 0.7% had a history of venous thromboembolism, and 2.5% had a history of cancer. Patients received a mean of 8.8±10.6 in-hospital thromboprophylaxis doses and were prescribed a median 21-day supply of thromboprophylaxis at discharge. Death occurred in 47 patients (0.78%) in the aspirin group and in 45 patients (0.73%) in the low-molecular-weight-heparin group (difference, 0.05 percentage points; 96.2% confidence interval, -0.27 to 0.38; P<0.001 for a noninferiority margin of 0.75 percentage points). Deep-vein thrombosis occurred in 2.51% of patients in the aspirin group and 1.71% in the low-molecular-weight-heparin group (difference, 0.80 percentage points; 95% CI, 0.28 to 1.31). The incidence of pulmonary embolism (1.49% in each group), bleeding complications, and other serious adverse events were similar in the two groups. CONCLUSIONS: In patients with extremity fractures that had been treated operatively or with any pelvic or acetabular fracture, thromboprophylaxis with aspirin was noninferior to low-molecular-weight heparin in preventing death and was associated with low incidences of deep-vein thrombosis and pulmonary embolism and low 90-day mortality. (Funded by the Patient-Centered Outcomes Research Institute; PREVENT CLOT ClinicalTrials.gov number, NCT02984384.).

Pharmacology of Heparin and Related Drugs: An Update.

Heparin has been used extensively as an antithrombotic and anticoagulant for close to 100 years. This anticoagulant activity is attributed mainly to the pentasaccharide sequence, which potentiates the inhibitory action of antithrombin, a major inhibitor of the coagulation cascade. More recently it has been elucidated that heparin exhibits anti-inflammatory effect via interference of the formation of neutrophil extracellular traps and this may also contribute to heparin's antithrombotic activity. This illustrates that heparin interacts with a broad range of biomolecules, exerting both anticoagulant and nonanticoagulant actions. Since our previous review, there has been an increased interest in these nonanticoagulant effects of heparin, with the beneficial role in patients infected with SARS2-coronavirus a highly topical example. This article provides an update on our previous review with more recent developments and observations made for these novel uses of heparin and an overview of the development status of heparin-based drugs. SIGNIFICANCE STATEMENT: This state-of-the-art review covers recent developments in the use of heparin and heparin-like materials as anticoagulant, now including immunothrombosis observations, and as nonanticoagulant including a role in the treatment of SARS-coronavirus and inflammatory conditions.

Low molecular weight heparin promotes the PPAR pathway by protecting the glycocalyx of cells to delay the progression of diabetic nephropathy.

Diabetic nephropathy (DN) is one of the most important comorbidities for diabetic patients, which is the main factor leading to end-stage renal disease. Heparin analogs can delay the progression of DN, but the mechanism is not fully understood. In this study, we found that low molecular weight heparin therapy significantly upregulated some downstream proteins of the peroxisome proliferator-activated receptor (PPAR) signaling pathway by label-free quantification of the mouse kidney proteome. Through cell model verification, low molecular weight heparin can protect the heparan sulfate of renal tubular epithelial cells from being degraded by heparanase that is highly expressed in a high-glucose environment, enhance the endocytic recruitment of fatty acid-binding protein 1, a coactivator of the PPAR pathway, and then regulate the activation level of intracellular PPAR. In addition, we have elucidated for the first time the molecular mechanism of heparan sulfate and fatty acid-binding protein 1 interaction. These findings provide new insights into understanding the role of heparin in the pathogenesis of DN and developing corresponding treatments.

Infection and transmission of SARS-CoV-2 depend on heparan sulfate proteoglycans.

The current pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and outbreaks of new variants highlight the need for preventive treatments. Here, we identified heparan sulfate proteoglycans as attachment receptors for SARS-CoV-2. Notably, neutralizing antibodies against SARS-CoV-2 isolated from COVID-19 patients interfered with SARS-CoV-2 binding to heparan sulfate proteoglycans, which might be an additional mechanism of antibodies to neutralize infection. SARS-CoV-2 binding to and infection of epithelial cells was blocked by low molecular weight heparins (LMWH). Although dendritic cells (DCs) and mucosal Langerhans cells (LCs) were not infected by SARS-CoV-2, both DC subsets efficiently captured SARS-CoV-2 via heparan sulfate proteoglycans and transmitted the virus to ACE2-positive cells. Notably, human primary nasal cells were infected by SARS-CoV-2, and infection was blocked by pre-treatment with LMWH. These data strongly suggest that heparan sulfate proteoglycans are important attachment receptors facilitating infection and transmission, and support the use of LMWH as prophylaxis against SARS-CoV-2 infection.

Extended Pharmacologic Prophylaxis for Venous Thromboembolism After Colon Cancer Surgery Is Associated With Improved Long-term Survival: A Natural Experiment in the Chemotherapeutic Benefit of Heparin Derivatives.

OBJECTIVE: This large database study assessed whether extended pharmacologic prophylaxis for venous thromboembolism after colon cancer resection was associated with improved oncologic survival. BACKGROUND: Heparin derivatives may confer an antineoplastic effect via a variety of mechanisms (eg, inhibiting angiogenesis in the tumor microenvironment). Studies evaluating the oncologic benefit of heparin and its derivatives have been limited in postsurgical patients. Multiple society guidelines recommend consideration of 30-day treatment with low molecular weight heparin to reduce venous thromboembolism risk after abdominopelvic cancer surgery. However, utilization of extended prophylaxis remains low. METHODS: Surveillance, Epidemiology, and End Results-Medicare data were used to identify patients (age 65+) undergoing resection for nonmetastatic colon cancer from 2016 to 2017. The primary outcomes were overall and cancer-specific survival. Log-rank testing and multivariable Cox regression compared survival in patients who received extended prophylaxis versus those who did not in an inverse propensity treatment weighted cohort. RESULTS: A total of 20,102 patients were included in propensity-weighting and analyzed. Eight hundred (3.98%) received extended pharmacologic prophylaxis. Overall survival and cancer-specific survival were significantly higher in patients receiving prophylaxis on log-rank tests ( P =0.0017 overall, P =0.0200 cancer-specific). Multivariable Cox regression showed improved overall survival [adjusted hazard ratio 0.66 (0.56-0.78)] and cancer-specific survival [adjusted hazard ratio 0.56 (0.39-0.81)] with prophylaxis after controlling for patient, treatment, and hospital factors. CONCLUSIONS: Extended pharmacologic prophylaxis after colon cancer resection was independently associated with improved overall and cancer-specific survival. These results suggest a potential antineoplastic effect from heparin derivatives when used in the context of preventing postsurgical venous thromboembolism.

Heparin for women with recurrent miscarriage and inherited thrombophilia (ALIFE2): an international open-label, randomised controlled trial.

BACKGROUND: Anticoagulant therapy might reduce the number of miscarriages and adverse pregnancy outcomes in women with recurrent pregnancy loss and inherited thrombophilia. We aimed to assess use of low-molecular-weight heparin (LMWH) versus standard care in this population. METHODS: The ALIFE2 trial was an international open-label, randomised controlled trial undertaken in hospitals in the UK (n=26), the Netherlands (n=10), the USA (n=2), Belgium (n=1), and Slovenia (n=1). Women aged 18-42 years who had two or more pregnancy losses and confirmed inherited thrombophilia, and who were trying to conceive or were already pregnant (≤7 weeks' gestation), were eligible for inclusion. Women were randomly assigned (1:1) to use low-dose LMWH or not (alongside standard care in both groups) once they had a positive urine pregnancy test. LMWH was started at or before 7 weeks' gestation and continued until the end of pregnancy. The primary outcome measure was livebirth rate, assessed in all women with available data. Safety outcomes included bleeding episodes, thrombocytopenia, and skin reactions, and were assessed in all randomly assigned women who reported a safety event. The trial was registered within the Dutch Trial Register (NTR3361) and EudraCT (UK: 2015-002357-35). FINDINGS: Between Aug 1, 2012, and Jan 30, 2021, 10 625 women were assessed for eligibility, 428 were registered, and 326 conceived and were randomly assigned (164 to LMWH and 162 to standard care). 116 (72%) of 162 women with primary outcome data in the LMWH group and 112 (71%) of 158 in the standard care group had livebirths (adjusted odds ratio 1·08, 95% CI 0·65 to 1·78; absolute risk difference, 0·7%, 95% CI -9·2% to 10·6%). 39 (24%) of 164 women in the LMWH group and 37 (23%) of 162 women in the standard care group reported adverse events. INTERPRETATION: LMWH did not result in higher livebirth rates in women who had two or more pregnancy losses and confirmed inherited thrombophilia. We do not advise use of LMWH in women with recurrent pregnancy loss and inherited thrombophilia, and we advise against screening for inherited thrombophilia in women with recurrent pregnancy loss. FUNDING: National Institute for Health and Care Research and the Netherlands Organization for Health Research and Development.

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.).

Impact of perioperative low-molecular-weight heparin therapy on clinical events of elderly patients with prior coronary stents implanted > 12 months undergoing non-cardiac surgery: a randomized, placebo-controlled trial.

BACKGROUND: Little is known about the safety and efficacy of discontinuing antiplatelet therapy via LMWH bridging therapy in elderly patients with coronary stents implanted for > 12 months undergoing non-cardiac surgery. This randomized trial was designed to compare the clinical benefits and risks of antiplatelet drug discontinuation via LMWH bridging therapy. METHODS: Patients were randomized 1:1 to receive subcutaneous injections of either dalteparin sodium or placebo. The primary efficacy endpoint was cardiac or cerebrovascular events. The primary safety endpoint was major bleeding. RESULTS: Among 2476 randomized patients, the variables (sex, age, body mass index, comorbidities, medications, and procedural characteristics) and percutaneous coronary intervention information were not significantly different between the bridging and non-bridging groups. During the follow-up period, the rate of the combined endpoint in the bridging group was significantly lower than in the non-bridging group (5.79% vs. 8.42%, p = 0.012). The incidence of myocardial injury in the bridging group was significantly lower than in the non-bridging group (3.14% vs. 5.19%, p = 0.011). Deep vein thrombosis occurred more frequently in the non-bridging group (1.21% vs. 0.4%, p = 0.024), and there was a trend toward a higher rate of pulmonary embolism (0.32% vs. 0.08%, p = 0.177). There was no significant difference between the groups in the rates of acute myocardial infarction (0.81% vs. 1.38%), cardiac death (0.24% vs. 0.41%), stroke (0.16% vs. 0.24%), or major bleeding (1.22% vs. 1.45%). Multivariable analysis showed that LMWH bridging, creatinine clearance < 30 mL/min, preoperative hemoglobin < 10 g/dL, and diabetes mellitus were independent predictors of ischemic events. LMWH bridging and a preoperative platelet count of < 70 × 109/L were independent predictors of minor bleeding events. CONCLUSIONS: This study showed the safety and efficacy of perioperative LMWH bridging therapy in elderly patients with coronary stents implanted > 12 months undergoing non-cardiac surgery. An alternative approach might be the use of bridging therapy with half-dose LMWH. TRIAL REGISTRATION: ISRCTN65203415.

Combination anticoagulation strategy in pregnancy with mechanical valves: The KYBELE study.

BACKGROUND: Optimal first-trimester anticoagulation is still challenging in pregnant women with mechanical heart valves (MHVs) requiring high-dose warfarin. This multicenter prospective study aims to determine the optimal anticoagulation regimens for pregnant patients with MHVs. METHODS: All women were allocated to one of three treatment options during first trimester including lone low-molecular-weight heparin (LMWH), combination of LMWH + 2.5 mg warfarin, and LMWH+4 mg warfarin. Primary maternal outcome included a combination of death, thromboembolism, severe bleeding, and need for treatment of mechanical valve thrombosis (MVT). Any fetal loss was determined as primary fetal outcome. RESULTS: The study included 78 pregnancies in 65 women with MHVs. Primary maternal outcome rate was 44%, 12.5%, 3.5%, respectively. The rates of primary maternal outcome (44 vs 3.5%, P < .001), obstructive MVT (16 vs 0%, P = .04), MVT requiring treatment (28 vs 0%, P = .003), and cerebral embolism (24 vs 3.4%, P = .041) were found to be significantly higher in lone LMWH group compared to LMWH + 4 mg warfarin group. Moreover, the rates of primary maternal outcome (12.5 vs 44%, P = .015) and treatment for MHV thrombus (4.2 vs 28%, P = .049) were significantly lower in LMWH + 2.5 mg warfarin group compared to lone LMWH group. The incidences of fetal loss were 8 (32%) in the lone LMWH group, 8 (33.3%) in LMWH + 2.5 mg warfarin group, and 11 (37.9%) in LMWH + 4 mg warfarin group (P = .890 for 3-group).Warfarin related-embryopathy was not observed in any case. CONCLUSIONS: The combined anticoagulation strategy of LMWH plus low-dose warfarin during the first trimester of pregnancy may result in less maternal complications with comparable fetal outcomes in patients with MHVs. CONDENSED ABSTRACT: Low-molecular-weight heparin (LMWH) is thought to be safer for the fetus, however it is suspected to be less protective for the mother. To solve this dilemma, the authors suggested a novel anticoagulation strategy in pregnant women with prosthetic valves. Seventy-eight pregnancies of 65 women (median age 32 [27-35] years) were included in the study. A combination of LMWH and a reduced dose warfarin were associated with low rates of thrombus-related complications in pregnant patients with mechanical heart valves.

Being precise with anticoagulation to reduce adverse drug reactions: are we there yet?

Anticoagulants are potent therapeutics widely used in medical and surgical settings, and the amount spent on anticoagulation is rising. Although warfarin remains a widely prescribed oral anticoagulant, prescriptions of direct oral anticoagulants (DOACs) have increased rapidly. Heparin-based parenteral anticoagulants include both unfractionated and low molecular weight heparins (LMWHs). In clinical practice, anticoagulants are generally well tolerated, although interindividual variability in response is apparent. This variability in anticoagulant response can lead to serious incident thrombosis, haemorrhage and off-target adverse reactions such as heparin-induced thrombocytopaenia (HIT). This review seeks to highlight the genetic, environmental and clinical factors associated with variability in anticoagulant response, and review the current evidence base for tailoring the drug, dose, and/or monitoring decisions to identified patient subgroups to improve anticoagulant safety. Areas that would benefit from further research are also identified. Validated variants in VKORC1, CYP2C9 and CYP4F2 constitute biomarkers for differential warfarin response and genotype-informed warfarin dosing has been shown to reduce adverse clinical events. Polymorphisms in CES1 appear relevant to dabigatran exposure but the genetic studies focusing on clinical outcomes such as bleeding are sparse. The influence of body weight on LMWH response merits further attention, as does the relationship between anti-Xa levels and clinical outcomes. Ultimately, safe and effective anticoagulation requires both a deeper parsing of factors contributing to variable response, and further prospective studies to determine optimal therapeutic strategies in identified higher risk subgroups.

Pleiotropic Effects of Heparin and its Monitoring in the Clinical Practice.

Unfractionated heparin (UFH) was uncovered in 1916, has been used as an anticoagulant since 1935, and has been listed in the World Health Organization's Model List of Essential Medicines. Despite the availability of many other anticoagulants, the use of heparin (either low molecular weight heparin [LMWH] or UFH) is still substantial. Heparin has pleotropic effects including anticoagulant and several nonanticoagulant properties such as antiproliferative, anti-inflammatory activity, and anticomplement effects. Although UFH has been widely replaced by LMWH, UFH is still the preferred anticoagulant of choice for patients undergoing cardiopulmonary bypass surgery, extracorporeal membrane oxygenation, and patients with high-risk mechanical cardiac valves requiring temporary bridging with a parenteral anticoagulant. UFH is a highly negatively charged molecule and binds many positively charged molecules, hence has unpredictable pharmacokinetics, and variable anticoagulant effect on an individual patient basis. Therefore, anticoagulant effects of UFH may not be proportional to the dose of UFH given to any individual patient. In this review, we discuss the anticoagulant and nonanticoagulant activities of UFH, differences between UFH and LMWH, when to use UFH, different methods of monitoring the anticoagulant effects of UFH (including activated partial thromboplastin time, heparin anti-Xa activity level, and activated clotting time), while discussing pros and cons related to each method and comparison of clinical outcomes in patients treated with UFH monitored with different methods based on available evidence.

How I treat and prevent venous thrombotic complications in patients with lymphoma.

Venous thromboembolism (VTE) is a common complication occurring in 5% to 10% of patients with lymphoma. As the complexity of lymphoma management has increased with novel therapies, so too has the treatment of VTE. Therapeutic options for the treatment of cancer-associated VTE have expanded from only warfarin and low-molecular-weight heparins (LMWHs) to include the direct oral anticoagulants (DOACs) apixaban, edoxaban and rivaroxaban. There have been no head-to-head trials comparing different DOACs in this setting, and randomized trials comparing a DOAC with LMWH dalteparin differ in trial design and results. Drug-drug interactions, drug-specific side effects, and patient selection are important considerations when prescribing anticoagulant therapy. In all patients, the relative risks of thrombosis and bleeding, the availability of the anticoagulant, and the life expectancy of the patient are vital elements in selecting the most appropriate anticoagulant (which can vary over time) for the individual patient. We describe the intricacies and challenges of treating thrombotic complications in patients with lymphoma with an emphasis on evidence and guideline-based care.

Low molecular weight heparin decreases pro-coagulant activity in clinical MSC products.

BACKGROUND AIMS: Mesenchymal stromal cells (MSCs) are multipotent adult cells that can be isolated from tissues including bone marrow [MSC(BM)], adipose [MSC(AT)] and umbilical cord [MSC(CT)]. Previous studies have linked expression of tissue factor (TF) on MSC surfaces to a procoagulant effect. Venous thromboembolism (VTE), immediate blood-mediated inflammatory reaction (IBMIR) and microvascular thrombosis remain a risk with intravascular MSC therapy. We examined the effect of low molecular weight heparin (LMWH) on clinical-grade MSCs using calibrated automated thrombography (CAT). METHODS: Clinical grade MSC(BM)s, MSC(AT)s and MSC(CT)s harvested at passage 4 were added to normal pooled plasma (NPP) to a final concentration of either 400 000 or 50 000 cells/mL. LMWH was added to plasma in increments of 0.1 U/mL. Thrombin generation (TG) was measured using CAT. Flow cytometry was conducted on the cells to measure MSC phenotype and TF load. RESULTS: Presence of MSCs decreased lag time and increased peak TG. All cell lines demonstrated a dose response to LMWH, with MSC(AT) demonstrating the least thrombogenicity and most sensitivity to LMWH. TG was significantly reduced in all cell lines at doses of 0.2 U/mL LMWH and higher. DISCUSSION: All MSC types and concentrations had a decrease in peak thrombin and TG with increasing amounts of LMWH. While this in vitro study cannot determine optimal dosing, it suggests that LMWH can be effectively used to lower the risk of VTE associated with intravascular administration of MSCs. Future in vivo work can be done to determine optimal dosing and effect on IBMIR and VTE.

Discussion on the evaluation of the therapeutic efficacy of uterine artery blood flow parameters and serum PLGF and sFlt-1 in patients with recurrent spontaneous abortion.

OBJECTIVE: To investigate the effects of different drug treatments on uterine artery blood flow parameters, serum placental growth factor (PLGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and sFlt-1/PLGF in patients with recurrent spontaneous abortion and to explore the predictive value of uterine artery blood flow parameters, serum PLGF, sFlt-1, and sFlt-1/PLGF for pregnancy outcomes. METHODS: This retrospective cohort study included 173 patients who experienced recurrent spontaneous abortion and 100 control patients. Patients with recurrent spontaneous abortion were divided into an aspirin group (75 patients), aspirin combined with low molecular weight heparin (LMWH) group (68 patients), and non-drug group (30 patients) based on different drug treatments. Uterine artery blood flow parameters at gestational weeks 30-31+6 were monitored for the four groups, and serum samples were collected at gestational weeks 30-31+6 to measure the levels of serum PLGF and sFlt-1 and calculate the sFlt-1/PLGF ratio. RESULTS: 1. Uterine artery blood flow parameters at gestational weeks 30-31+6 were significantly greater in the non-drug group than in the aspirin group, combined drug group, and control group (p<0.05). 2. Serum PLGF levels and the sFlt-1/PLGF ratio at gestational weeks 30-31+6 were significantly lower in the non-drug group than in the aspirin group, combined drug group, and control group, while serum sFlt-1 levels were significantly greater in the non-drug group than in the aspirin group, combined drug group, and control group (p<0.05). 3. Serum PLGF, sFlt-1, and sFlt-1/PLGF had lower diagnostic efficiency for predicting hypertensive disorders during pregnancy than the combined diagnostic efficiency of serum PLGF, sFlt-1, and sFlt-1/PLGF with uterine artery blood flow parameters at gestational weeks 30-31+6. CONCLUSION: Aspirin and aspirin combined with LMWH can upregulate serum PLGF and decrease serum sFlt-1 levels in patients with recurrent spontaneous abortion, reduce the miscarriage rate, and significantly improve pregnancy outcomes. The combination of serum PLGF, sFlt-1, sFlt-1/PLGF, and uterine artery blood flow parameters can effectively predict hypertensive disorders during pregnancy.

Effectiveness and Safety of Extended Treatment Apixaban Versus Low-Molecular-Weight Heparin in Cancer-Associated Venous Thromboembolism.

BACKGROUND: Limited real-world evidence is available comparing the safety and effectiveness of apixaban and low-molecular-weight heparins (LMWHs) for preventing recurrent venous thromboembolism (VTE) in patients with active cancer receiving anticoagulation in an extended treatment setting. This study evaluated the risk of bleeding and recurrent VTE in patients with cancer-associated VTE who were prescribed apixaban or LMWH for ≥3 months. METHODS: A US commercial claims database was used to identify adult patients with VTE and active cancer who initiated apixaban or LMWH 30 days following the first VTE diagnosis and had ≥3 months of continuous enrollment and 3 months of primary anticoagulation treatment. Patients were followed from the day after the end of primary anticoagulation treatment until the earliest of: date of disenrollment, discontinuation of index anticoagulant, switch to another anticoagulant, or end of the study period. Inverse-probability treatment weighting (IPTW) was used to balance treatment cohorts. Incidence rates (IRs) for the outcomes were calculated per 100 person-years (PY). Cox proportional hazard models were used to evaluate the adjusted risk of recurrent VTE, major bleeding (MB), and clinically relevant nonmajor bleeding (CRNMB). RESULTS: A total of 13,564 apixaban- and 2,808 LMWH-treated patients were analyzed. Post-IPTW, the treatment cohorts were balanced. Patients receiving apixaban had lower adjusted IRs for recurrent VTE (4.1 vs 9.6 per 100 PY), MB (6.3 vs 12.6), and CRNMB (26.1 vs 36.0) versus LMWH (P<.0001 for all comparisons) during the follow-up period. Patients on apixaban had a lower adjusted risk of recurrent VTE (hazard ratio [HR], 0.42; 95% CI, 0.34-0.53), MB (HR, 0.50; 95% CI, 0.41-0.61), and CRNMB (HR, 0.76; 95% CI, 0.68-0.85) versus LMWH. CONCLUSIONS: Extended anticoagulation treatment of ≥3 months with apixaban was associated with lower rates of recurrent VTE, MB, and CRNMB compared with LMWH in adults with cancer-associated VTE.

Six-week low-molecular-weight heparin versus 12-week warfarin for calf deep vein thrombosis: A randomized, prospective, open-label study.

Current guidelines suggest a 3-month anticoagulant treatment course for isolated distal deep vein thrombosis (IDDVT), but shorter durations of treatment are frequently prescribed in clinical practice. We investigated whether a 6-week treatment with low-molecular-weight heparin (LMWH) at intermediate dosage can be an effective and safe alternative to vitamin K antagonists (VKA) in patients with IDDVT (non-inferiority trial). In a multicenter, open-label, randomized trial, 260 outpatients with symptomatic IDDVT were randomly assigned to receive either LMWH followed by VKA for 12 weeks or LMWH 1 mg/kg subcutaneously twice a day for 2 weeks followed by 1 mg/kg subcutaneously once a day for 4 weeks. The follow-up was 6 months and the primary endpoint was the composite measure of recurrent venous thromboembolism (VTE) defined as: recurrence or extension of IDDVT, proximal DVT, and pulmonary embolism (PE). The study was stopped prematurely due to slow recruiting rates. The primary efficacy outcome occurred in 14 patients receiving LMWH (10.8%) and in five patients receiving VKA (3.8%); risk difference was 0.069 (95% CI: 0.006-0.132), hazard ratio 2.8 (95% CI: 1.04-7.55). There was one PE in the VKA group and one proximal DVT in the LMWH group. IDDVT recurrence was 10.0% in the LMWH group versus 3.1% in the VKA group (p = .024). Two patients had clinically relevant bleedings (1.6%) in the LMWH group versus one (0.8%) in VKA group (p = .56). In conclusion, VKA for 12 weeks seems superior to LMWH for 6 weeks in reducing the risk of VTE recurrences in our cohort of outpatients with IDDVT.

National Analysis of Outcomes for Adult Trauma Patients With Isolated Severe Blunt Traumatic Brain Injury Following Venous Thromboembolism Prophylaxis.

INTRODUCTION: We aim to evaluate the association of early versus late venous thromboembolism (VTE) prophylaxis on in-hospital mortality among patients with severe blunt isolated traumatic brain injuries. METHODS: Data from the American College of Surgeons Trauma Quality Program Participant Use File for 2017-2021 were analyzed. The target population included adult trauma patients with severe isolated traumatic brain injury (TBI). VTE prophylaxis types (low molecular weight heparin and unfractionated heparin) and their administration timing were analyzed in relation to in-hospital complications and mortality. RESULTS: The study comprised 3609 patients, predominantly Caucasian males, with an average age of 48.5 y. Early VTE prophylaxis recipients were younger (P < 0.01) and more likely to receive unfractionated heparin (P < 0.01). VTE prophylaxis later than 24 h was associated with a higher average injury severity score and longer intensive care unit stays (P < 0.01). Logistic regression revealed that VTE prophylaxis later than 24 h was associated with significant reduction of in-hospital mortality by 38% (odds ratio 0.62, 95% confidence interval 0.40-0.94, P = 0.02). Additionally, low molecular weight heparin use was associated with decreased mortality odds by 30% (odds ratio 0.70, 95% confidence interval 0.55-0.89, P < 0.01). CONCLUSIONS: VTE prophylaxis later than 24 h is associated with a reduced risk of in-hospital mortality in patients with severe isolated blunt TBI, as opposed to VTE prophylaxis within 24 h. These findings suggest the need for timely and appropriate VTE prophylaxis in TBI care, highlighting the critical need for a comprehensive assessment and further research concerning the safety and effectiveness of VTE prophylaxis in these patient populations.

The efficacy and safety of direct oral anticoagulants compared with low-molecular-weight heparin for venous thromboembolism prophylaxis after surgical resection of primary lower extremity bone or soft-tissue sarcoma.

INTRODUCTION: The incidence of postoperative venous thromboembolism (VTE) and wound complications is greater after sarcoma resection. We sought to identify differences in postoperative VTE and bleeding complications with direct oral anticoagulants (DOACs) versus low-molecular-weight heparin (LMWH) following resection of lower extremity primary bone or soft tissue sarcoma. METHODS: We retrospectively identified 2083 patients from the PearlDiver database who underwent resection of primary bone or soft tissue sarcoma of the lower extremity from January 2010 to October 2021 and prescribed LMWH or DOAC within 90-days postoperatively. The primary outcomes were comparison of postoperative incidence and odds of deep venous thrombosis (DVT), pulmonary embolism (PE), and bleeding complications within 90-days following resection. RESULTS: Patients prescribed DOACs had a greater odds of DVT (odds ratio [OR]: 1.60; 95% confidence interval [CI]: 1.06-2.41; p = 0.024) and PE (OR: 3.38; 95% CI: 1.96-5.86; p < 0.001) within 90-days following resection of bone sarcoma when compared with the LMWH cohort. Patients undergoing resection of soft tissue sarcomas also had greater odds DVT (OR: 1.65; 95% CI: 1.09-2.49; p = 0.016) and PE (OR: 2.62; 95% CI: 1.52-4.54; p < 0.001) in the DOAC cohort. There was no difference in the odds of bleeding complications. CONCLUSION: This study demonstrated an increased incidence and odds of VTE, but not bleeding complications, when using DOACs versus LMWH after primary bone or soft tissue sarcoma resection. LEVEL OF EVIDENCE: Level III.

Updates in the Incidence, Pathogenesis, and Management of Cancer and Venous Thromboembolism.

Patients with cancer are at higher risk of developing venous thromboembolism (VTE) compared with the general population. This elevated risk is due to several risk factors and multiple, overlapping thrombotic and hemostatic pathophysiological pathways that are specific to this patient population. Hence, the management of cancer-associated VTE can be challenging for clinicians. Patients with cancer-associated VTE are at higher risk of both recurrent events despite anticoagulation and bleeding complications due to the anticoagulant regimens. Direct oral anticoagulants have recently been shown to be effective, safe, and more convenient than parenteral low-molecular-weight heparin for the management of cancer-associated VTE. Despite these recent advances in anticoagulant therapy, many unmet needs remain in these patients (increased risk of bleeding with specific cancer types, drug-drug interactions, liver dysfunction). Factor XI inhibitors are currently being assessed for the management of cancer-associated VTE and may help clinicians address these important knowledge gaps.