Given the existing uncertainty regarding the effectiveness and safety of switching from low-molecular-weight heparin (LMWH) to direct oral anticoagulants (DOACs) in patients with cancer-associated venous thrombosis (CAT), we conducted a comprehensive population-based cohort study utilizing electronic health database in Hong Kong. A total of 4356 patients with CAT between 2010 and 2022 were included, with 1700 (39.0%) patients switching to DOAC treatment. Compared to continuous LMWH treatment, switching to DOACs was associated with a significantly lower risk of hospitalization due to venous thromboembolism (HR: 0.49 [95% CI = 0.35-0.68]) and all-cause mortality (HR: 0.67 [95% CI = 0.61-0.74]), with no significant difference in major bleeding (HR: 1.04 [95% CI = 0.83-1.31]) within six months. These findings provide reassurance regarding the effectiveness and safety of switching from LMWH to DOACs among patients with CAT, including vulnerable patient groups.

Obstetric antiphospholipid syndrome (OAPS) is an autoimmune disorder associated with various pathological pregnancies, such as recurrent miscarriage, stillbirth, severe pre-eclampsia and severe placental insufficiency. The persistent presence of antiphospholipid antibodies (aPLs) is the most important laboratory characteristic of OAPS. OAPS severely affects the reproductive health of women of childbearing age in China. Reports indicate that approximately 9.6% stillbirths, 11.5% severe pre-eclampsia, and 54% recurrent miscarriages are associated with OAPS or aPLs. However, the pathogenesis of OAPS remains unclear. Previously, thrombosis at the maternal-fetal interface (MFI) was considered the main mechanism of OAPS-related pathological pregnancies. Consequently, the use of low molecular weight heparin and aspirin throughout pregnancy was recommended to improve outcomes in OAPS patient. In recent years, many studies have found that thrombosis in MFI is uncommon, but various inflammatory factors are significantly increased in the MFI of OAPS patients. Based on these findings, some clinicians have started using anti-inflammatory treatments for OAPS, which have preliminarily improved the pregnancy outcomes. Nevertheless, there is no consensus on these second-line treatments of OAPS. Another troubling issue is the clinical diagnosis of OAPS. Similar to other autoimmune diseases, there are only classification criteria for OAPS, and clinical diagnosis of OAPS depends on the clinicians\' experience. The present classification criteria of OAPS were established for clinical and basic research purposes, not for patient clinical management. In clinical practice, many patients with both positive aPLs and pathological pregnancy histories do not meet the strict OAPS criteria. This has led to widespread issues of incorrect diagnosis and treatment. Timely and accurate diagnosis of OAPS is crucial for effective treatment. In this article, we reviewed the epidemiological research progress on OAPS and summarized its classification principles, including: 1) the persistent presence of aPLs in circulation; 2) manifestations of OAPS, excluding other possible causes. For the first point, accurate assessment of aPLs is crucial; for the latter, previous studies regarded only placenta-related pregnancy complications as characteristic manifestations of OAPS. However, recent studies have indicated that adverse pregnancy outcomes related to trophoblast damage, such as recurrent miscarriage and stillbirth, also need to be considered in OAPS. We also discussed several key issues in the diagnosis and treatment of OAPS. First, we addressed the definition of non-standard OAPS and offered our opinion on defining non-standard OAPS within the framework of the 2023 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) APS criteria. Then, we discussed the advantages and disadvantages of different aPL testing methods, emphasizing that harmonizing results across platforms and establishing specific reference values are keys to resolving controversies in aPL testing results. We also introduced the application of non-criteria aPLs, especially anti-phosphatidylserine/prothrombin antibody (aPS/PT) and anti-β2 glycoprotein Ⅰ domain Ⅰ antibody (aβ2GPⅠDⅠ). Additionally, we discussed aPL-based OAPS risk classification strategies. Finally, we proposed potential treatment methods for refractory OAPS. The goal is to provide a reference for the clinical management of OAPS.

Unfractionated heparin (UFH) and its low-molecular-weight fragments (LMWH) are widely used as anticoagulants for surgical procedures and extracorporeal blood purification therapies such as cardiovascular surgery and dialysis. The anticoagulant effect of heparin is essential for the optimal execution of extracorporeal blood circulation. However, at the end of these procedures, to avoid the risk of bleeding, it is necessary to neutralize it. Currently, the only antidote for heparin neutralization is protamine sulphate, a highly basic protein which constitutes a further source of serious side events and is ineffective in neutralizing LMWH. Furthermore, dialysis patients, due to the routine administration of heparin, often experience serious adverse effects, among which HIT (heparin-induced thrombocytopenia) is one of the most severe. For this reason, the finding of new heparin antagonists or alternative methods for heparin removal from blood is of great interest. Here, we describe the synthesis and characterization of a set of biocompatible macroporous cryogels based on poly(2-hydroxyethyl methacrylate) (pHEMA) and L-lysine with strong filtering capability and remarkable neutralization performance with regard to UFH and LMWH. These properties could enable the design and creation of a filtering device to rapidly reverse heparin, protecting patients from the harmful consequences of the anticoagulant.

The etiology of recurrent pregnancy loss (RPL) is complex and multifactorial and in half of patients it remains unexplained (U-RPL). Recently, low-molecular-weight heparin (LMWH) has gained increasing relevance for its therapeutic potential. On this regard, the aim of this systematic review and meta-analysis is to analyze the efficacy of low molecular weight heparin (LMWH) from the beginning of pregnancy in terms of live birth rates (LBR) in U-RPL. Registered randomized controlled trials (RCTs) were included. We stratified findings based on relevant clinical factors including number of previous miscarriages, treatment type and control type. Intervention or exposure was defined as the administration of LMWH alone or in combination with low-dose aspirin (LDA). A total of 6 studies involving 1016 patients were included. The meta-analysis results showed that LMWH used in the treatment of U-RPL was not associated with an increase in LBR with a pooled OR of 1.01, a medium heterogeneity (26.42%) and no publication bias. Results of other sub-analyses according to country, treatment type, and control type showed no significant effect of LMWH on LBR in all subgroups, with a high heterogeneity. The results highlight a non-significant effect of LMWH in U-RPL on LBR based on moderate quality evidence.Registration number: PROSPERO: ( https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022326433 ).

BACKGROUND This prospective study from a single center aimed to compare the perioperative blood loss (PBL) in 79 patients with intertrochanteric fractures (IF) treated with intramedullary nailing (IMN) using 3 regimens of combined tranexamic acid (TXA) and low molecular weight heparin (LMWH), proposing a novel therapy of 4-dose TXA. MATERIAL AND METHODS We recruited 79 patients and randomly divided them into 3 groups. The 4-dose TXA group (22 patients) received 1.0 g intravenous TXA 30 min before surgery and 1.0 g at intervals of 3, 6, and 9 h before surgery. The 1-dose TXA group (25 patients) received 1.0 g intravenous TXA 30 min before surgery, while the control group (32 patients) did not receive TXA. LMWH was applied 12 h after surgery in each group. The primary metrics evaluated included hidden blood loss (HBL), total blood loss (TBL), and the number and incidence rate of deep vein thrombosis (DVT). RESULTS Analysis of the HBL revealed that the 4-dose TXA group had the lowest average (583.13±318.08 ml), followed by the 1-dose TXA group (902.94±509.99 ml), and the control group showed the highest (1154.39±452.06 ml) (P<0.05). A similar result was observed for TBL (4-dose group: 640.86±337.22 ml, 1-dose group: 971.74±511.14 ml, control group: 1226.27±458.22 ml, P<0.05). Regarding DVT, the 4-dose TXA group had 5 cases (incidence rate 22.73%), the 1-dose TXA group had 6 cases (incidence rate 24.00%), and the control group had 8 cases (incidence rate 25.00%), with no significant difference among groups (P>0.05). CONCLUSIONS Treatment using 4-dose TXA and LMWH can effectively reduce PBL without increasing the DVT risk in IF patients with IMN.

OBJECTIVE: Free tissue transfer has an established place in oncologic head and neck surgery. However, the necessity and specific regimen of perioperative thromboprophylaxis remain controversial. Here, the risk of postoperative hemorrhage contrasts with vascular pedicle thrombosis and graft loss. This work compares three different heparin protocols (A-C) with regard to postoperative complications.
METHODS: A retrospective analysis of our free flap transplants between 2004 and 2023 was conducted. Inclusion criteria were thromboprophylaxis with (A) 500 IU/h unfractionated heparin (UFH), (B) low-molecular-weight heparin (LMWH) once daily, and (C) LMWH once daily with additional immediate preoperative administration. Primary endpoints were the incidence of postoperative bleeding and hematoma and the appearance of flap thrombosis.
RESULTS: We evaluated 355 cases, 87 in group A, 179 in group B, and in group C 89 patients. Overall, postoperative bleeding occurred in 8.7% of patients, and 83% underwent hemostasis under intubation anesthesia, with no significant difference between groups (p = 0.784). Hematoma formation requiring revision was found in 3.7% of patients (p = 0.660). We identified postoperative hematoma as a significant influencing factor for venous pedicle thrombosis (OR 3.602; p = 0.001). Venous and arterial flap thrombosis in the graft vessel showed no difference between the groups (p = 0.745 and p = 0.128).
CONCLUSIONS: The three anticoagulation regimens appear to be equivalent therapy for the prevention of thrombosis without significant differences in postoperative bleeding. The use of LMWH with additional preoperative administration can, therefore, be administered in free flap reconstruction.

BACKGROUND: Patients with suspected deep vein thrombosis (DVT) are typically referred to the emergency department for immediate evaluation. To enhance efficiency, our hospital implemented a regional, general practitioner (GP)-driven DVT care pathway, deferring diagnostic evaluation to a scheduled outpatient DVT clinic appointment the following day. Patients receive a single dose anticoagulant from their GP to prevent thrombosis progression while awaiting diagnostic workup. This prospective study aimed to evaluate the safety and patient preferences regarding the DVT care pathway and the type of single dose anticoagulant (low-molecular-weight heparin (LMWH) vs. direct oral anticoagulant (DOAC)).
METHODS: Patients enrolled in the DVT care pathway between June 2021 and July 2023 were eligible. Until July 2022, LMWH was administered, and thereafter, the protocol recommended DOAC as the single dose anticoagulant. Patients completed questionnaires, incorporating patient-reported outcome and experience measures (PROMs/PREMs), during their DVT clinic visit and after five days. The primary endpoint was bleeding events within 72 h of receiving the single dose anticoagulant.
RESULTS: Of 460 included patients, 229 received LMWH and 231 received DOAC as the single dose anticoagulant. DVT was confirmed in 24.8 % of patients. No major or clinically relevant non-major bleeding were reported. LMWH was associated with more minor bleedings (22.3 % vs. DOAC 13.4 %), primarily attributed to injection site hematomas. Patients reported high satisfaction with the DVT care pathway (96.5 %) and generally preferred DOAC over LMWH.
CONCLUSIONS: Deferring diagnostic evaluation for DVT using a single dose of either LMWH or DOAC in a real-world population is deemed safe. Considering practical advantages, patient preferences, and fewer skin hematomas, we favor DOACs as the single dose anticoagulant in this care pathway.

The incidence and mortality of venous thromboembolism (VTE) are high in critically ill patients, and there is still a risk of VTE and bleeding after the use of fixed-dose low molecular weight heparin (LMWH) for prophylaxis. The level of anti-factor Xa is not up to standard after LMWH prophylaxis in patients with surgery or trauma. The condition of critically ill patients is complicated, and the proportion of patients with low antithrombin III is high, which can affect the prophylactic efficacy of LMWH and contribute to VTE occurrence. There is currently no consensus on whether adjusting LMWH dose according to anti-factor Xa levels can reduce VTE occurrence in critically ill patients. High-quality multicenter randomized controlled studies are needed in the future to establish new approaches for precise prevention of VTE in critically ill patients.

OBJECTIVE: Total hip arthroplasty (THA) is a highly successful and effective surgery for improving hip functions and relieving pain. However, the lower extremities are prone to deep vein thrombosis (DVT) and swelling after surgery, thereby delaying recovery. In this study, we investigated the preventive effects of fondaparinux sodium (FS) and low-molecular-weight heparin (LMWH) on DVT of the lower extremity after THA.
METHODS: Firstly, 60 patients who underwent THA at the First Affiliated Hospital of Wannan Medical College from March 2020 to December 2020 were included. Next, the patients were randomly divided into an LMWH group (n = 30) and an FS group (n = 30). Then, the indexes related to DVT were compared between both groups.
RESULTS: Specifically, the differences in baseline data, such as age, gender and body mass index (BMI), between the two groups were not statistically significant. The postoperative weight bearing time of patients in the FS group was much shorter than that in the LMWH group.
CONCLUSIONS: Subcutaneous injection of FS not only exhibits superior effects to LMWH in preventing DVT after THA but also has a correlation with reducing the risk of thrombosis and improving patient symptoms.

Low Molecular Weight Heparins (LMWHs) are well-established for use in the prevention and treatment of thrombotic diseases, and as a substitute for unfractionated heparin (UFH) due to their predictable pharmacokinetics and subcutaneous bioavailability. LMWHs are produced by various depolymerization methods from UFH, resulting in heterogeneous compounds with similar biochemical and pharmacological properties. However, the delicate supply chain of UFH and potential contamination from animal sources require new manufacturing approaches for LMWHs. Various LMWH preparation methods are emerging, such as chemical synthesis, enzymatic or chemical depolymerization and chemoenzymatic synthesis. To establish the sameness of active ingredients in both innovator and generic LMWH products, the Food and Drug Administration has implemented a stringent scientific method of equivalence based on physicochemical properties, heparin source material and depolymerization techniques, disaccharide composition and oligosaccharide mapping, biological and biochemical properties, and in vivo pharmacodynamic profiles. In this review, we discuss currently available LMWHs, potential manufacturing methods, and recent progress for manufacturing quality control of these LMWHs.