The effect and mechanism of low-molecular-weight heparin on the decidualization of stromal cells in early pregnancy

OBJECTIVE

This study aimed to analyze the effect of low-molecular-weight heparin (LMWH) on the decidualization of stromal cells in early pregnancy and explore the effect of LMWH on pregnancy outcomes.

METHODS

Recurrent spontaneous abortion (RSA) mouse model (CBA/J × DBA/2) and normal pregnant mouse model (CBA/J × BALB/c) were established. The female mice were checked for a mucus plug twice daily to identify a potential pregnancy. When a mucus plug was found, conception was considered to have occurred 12 h previously. The pregnant mice were divided randomly into a normal pregnancy control group, an RSA model group, and an RSA + LMWH experimental group (n = 10 mice in each group). Halfway through the 12th day of pregnancy, the embryonic loss of the mice was observed; a real-time quantitative polymerase chain reaction was used to detect the messenger ribonucleic acid (mRNA) expressions of prolactin (PRL) and insulin-like growth factor-binding protein 1 (IGFBP1) in the decidua of the mice. Additionally, the decidual tissues of patients with RSA and those of normal women in early pregnancy who required artificial abortion were collected and divided into an RSA group and a control group. Decidual stromal cells were isolated and cultured to compare cell proliferation between the two groups, and cellular migration and invasion were detected by membrane stromal cells. Western blotting was used to detect the protein expressions of proliferating cell nuclear antigen (PCNA), cyclin D1, matrix metalloproteinase- (MMP) 2, and MMP-7 in stromal cells treated with LMWH.

RESULTS

Compared with the RSA group, LMWH significantly reduced the pregnancy loss rate in the RSA mice (p < 0.05). Compared with the RSA group, the LMWH + RSA group had significantly higher expression levels of PRL and IGFBP1 mRNA (p < 0.01). LMWH promoted the proliferation, migration, and invasion of human decidual stromal cells; compared with the control group, the expression levels of MMP-2, MMP-7, cyclin D1, and PCNA proteins in the decidual stromal cells of the LMWH group increased (p < 0.05).

CONCLUSIONS

The use of LMWH can improve pregnancy outcomes by enhancing the proliferation and migration of stromal cells in early pregnancy and the decidualization of stromal cells.

Aspirin versus low-molecular-weight heparin for thromboprophylaxis after orthopaedic surgery: a systematic review and meta-analysis

The article aimed to compare the efficiency and safety of aspirin with low-molecular-weight heparin (LMWH) for thromboprophylaxis in orthopaedic surgery patients. According to the inclusion and exclusion criteria, PubMed, Embase and Cochrane Library database were searched for studies comparing aspirin and LMWH in venous thromboembolism (VTE) prophylaxis until 25 April 2023. The outcome measures included deep venous thrombosis(DVT)/Pulmonary embolism(PE) events, major bleeding events, wound complications, wound infection and death. Six studies met the requirements of our meta-analysis, including 12 470 patients in the aspirin group and 10 857 patients in the LMWH group. The meta-analysis showed that results showed that LMWH was superior to aspirin in preventing VTE events (odds ratio (OR) 1.44, 95% CI 1.24-1.68, P  < 0.00001), whereas there was no significant difference between them in bleeding events (OR 0.95, 95% CI 0.86-1.05, P  = 0.33), wound complication (OR 0.58, 95% CI 0.28-1.17, P  = 0.13), wound infection (OR 1.12, 95% CI 0.86-1.47, P  = 0.39) and mortality (OR 1.04, 95% CI 0.70-1.55, P  = 0.83). In addition, subgroup analysis showed that compared with aspirin, LMWH was more likely to reduce the incidence of DVT events in orthopaedic surgery patients (OR 1.59, 95% CI 1.33-1.91, P  < 0.00001), whereas there was no advantage in reducing the incidence of PE events (OR 1.22, 95% CI 0.62-2.40, P  = 0.56). Despite the similar safety profiles, this meta-analysis showed that LMWH was significantly superior to aspirin in thromboprophylaxis after orthopaedic surgery. LMWH was still the first-line drug for thrombosis prevention in patients who underwent major orthopaedic surgeries.

The Role of Direct Oral Anticoagulants in the Treatment of Cancer-Associated Venous Thromboembolism: Review by Middle East and North African Experts

Venous thromboembolism is a leading cause of morbidity and mortality in patients with active cancer who require anticoagulation treatment. Choice of anticoagulant is based on careful balancing of the risks and benefits of available classes of treatment: vitamin K antagonists, low-molecular-weight heparin (LMWH), and direct oral anticoagulants (DOACs). Results from randomized controlled trials have shown the consistent efficacy of DOACs versus LMWH in the treatment of cancer-associated venous thromboembolism (VTE). However, increased major gastrointestinal bleeding was observed for edoxaban and rivaroxaban, but not apixaban, compared with LMWH dalteparin. Most guidelines recommend DOACs for the treatment of cancer-associated VTE in patients without gastrointestinal or genitourinary cancer, and with considerations for renal impairment and drug-drug interactions. These updates represent a major paradigm shift for clinicians in the Middle East and North Africa. The decision to prescribe a DOAC for a patient with cancer is not always straightforward, particularly in challenging subgroups of patients with an increased risk of bleeding. In patients with gastrointestinal malignancies who are at high risk of major gastrointestinal bleeds, apixaban may be the preferred DOAC; however, caution should be exercised if patients have upper or unresected lower gastrointestinal tumors. In patients with gastrointestinal malignancies and upper or unresected lower gastrointestinal tumors, LMWH may be preferred. Vitamin K antagonists should be used only when DOACs and LMWH are unavailable or unsuitable. In this review, we discuss the overall evidence for DOACs in the treatment of cancer-associated VTE and provide treatment suggestions for challenging subgroups of patients with cancer associated VTE.

Characterization of the Benefits and Risks of Therapeutic Anticoagulation in Patients Admitted with Severe COVID-19 (CRITAC)

Background

Severe COVID-19 is associated with increased rates of thrombotic complications. Recent provincial recommendations in British Columbia have suggested providing thromboprophylaxis with therapeutic anticoagulation for hospital inpatients with severe COVID-19 who do not have a high risk of bleeding.

Objectives

To characterize the rates of major bleeding, thrombotic events, complications from COVID-19, and adverse effects among patients with severe COVID-19 treated with therapeutic anticoagulation.

Methods

This retrospective chart review involved patients with laboratory-confirmed COVID-19 who were admitted to 3 sites within a local health authority between April 1 and December 31, 2021, and received therapeutic anticoagulation for thromboprophylaxis.

Results

After screening of 1036 patients, 72 patients were included in the study. The mean age of participants was 54 years, 63% (n = 45) were male, and 92% (n = 66) were receiving supplemental oxygen by nasal prongs on admission. The primary outcome, major bleeding, was experienced by 1 patient (1%). Increasing oxygen requirements resulting in progression to high-flow nasal cannula occurred in 11 patients (15%), and 5 patients (7%) required admission to the intensive care unit. One patient (1%) experienced a thrombotic event, and 1 patient (1%) had a minor bleed. The mean duration of hospitalization was 10 (standard deviation 10.8) days. One death occurred during the study period, and no cases of heparin-induced thrombocytopenia were observed.

Conclusions

In this study of hospital inpatients with severe COVID-19 who were deemed to be at low risk of bleeding and who received therapeutic anticoagulation, there were low rates of both major bleeding and thrombotic events.

Effect of low-molecular-weight heparin on placenta-mediated fetal growth restriction in a tertiary referral hospital: A 7-year retrospective cohort study

OBJECTIVE

To investigate the effect of low-molecular-weight heparin (LMWH) on placenta-mediated fetal growth restriction (FGR).

METHODS

A cohort of 570 pregnant women diagnosed with placenta-mediated FGR were enrolled from January 1, 2015 through to December 31, 2021. A birth database, including demographic data, antenatal complications, and detailed delivery and newborn data, was created to collect variables from the Hospital Information System (HIS) Database. The unique personal registration number, assigned to each patient on first registration with HIS in the West China Second University Hospital, was used to link these patients. LMWH use was defined as at least 1-week prescription from diagnosis of placenta-mediated FGR. Pregnant women received LMWH (Enoxaparin 4000 IU/day) by self-administered subcutaneous injection only when they agreed and signed informed consent. Primary outcome was intrauterine fetal death after 20 weeks of pregnancy. Secondary outcomes included preterm birth (PB), Apgar score less than 7 at 1 min, admission to neonatal intensive care unit (NICU), and birth weight. Logistic regression analysis was conducted to compute adjusted odds ratio (aOR) with 95% confidence intervals (CI) for outcomes.

RESULTS

After controlling for confounders, LMWH use was associated with a decreased risk of intrauterine fetal death (aOR 2.49, 95% CI 1.35-4.57, P = 0.003), PB before 37 weeks of pregnancy (aOR 3.35, 95% CI 2.14-5.23, P < 0.001), PB before 34 weeks of pregnancy (aOR 2.25, 95% CI 1.36-3.74, P = 0.002), Apgar score less than 7 at 1 min (aOR 2.25, 95% CI 1.36-3.74, P = 0.002), NICU admission (aOR 2.29, 95% CI 1.48-3.55, P < 0.001). Using LMWH increased the mean birth weight in PB before 32 weeks of pregnancy (mean ± standard deviation [SD] 1126.4 ± 520.0 g, P = 0.020), PB before 37 weeks of pregnancy (mean ± SD 1563.9 ± 502.7 g, P = 0.019), early-onset FGR (mean ± SD 2125.2 ± 665.7 g, P < 0.001), late-onset FGR (mean ± SD 2343.4 ± 507.9, P < 0.001), and non-severe FGR (mean ± SD 2231.1 ± 607.2 g, P < 0.001).

CONCLUSION

Use of LMWH can significantly improve the fetal and neonatal outcomes among pregnant women with placenta-mediated FGR, particularly reducing the risk of intrauterine fetal death.

Incidence of Symptomatic Venous Thromboembolisms in Stroke Patients

Venous thromboembolism (VTE) is a common but preventable complication observed in critically ill patients. Deep vein thrombosis (DVT) is the most common type of VTE, with clinical significance based on location and symptoms. There is an increased incidence of DVT and pulmonary embolism (PE) in ischemic stroke patients using unfractionated heparin (UFH) for VTE prophylaxis compared with those using enoxaparin. However, UFH is still used in some patients due to its perceived safety, despite conflicting literature suggesting that enoxaparin may have a protective effect. The current study aimed to determine the incidence of VTEs in patients with acute ischemic strokes on UFH versus enoxaparin for VTE prophylaxis, subclassifying the VTEs depending on their location and symptoms. It also aimed to examine the safety profile of both drugs. A total of 909 patients admitted to the Neuro-ICU with the diagnosis of acute ischemic stroke were identified, and 634 patients were enrolled in the study-170 in the enoxaparin group and 464 in the UFH group-after applying the exclusion criteria. Nineteen patients in the UFH group (4.1%) and 3 patients in the enoxaparin group (1.8%) had a VTE. The incidence of DVT in the UFH group was 12 (2.6%), all of which were symptomatic, compared with 3 (1.8%) in the enoxaparin group, wherein one case was symptomatic. Nine patients (1.9%) in the UFH group developed a PE during the study period, and all of them were symptomatic. No patients in the enoxaparin group developed PE. No statistically significant difference was found between both groups. However, 18 patients in the UFH group (3.9%) experienced intracranial hemorrhage compared with none in the enoxaparin group, and this difference was statistically significant. Enoxaparin was found to be as effective as and potentially safer than UFH when used for VTE prophylaxis in stroke patients.

Clinical outcomes associated with anti-Xa-monitored enoxaparin for venous thromboembolism prophylaxis

STUDY OBJECTIVE

The objective of the study was to assess clinical outcomes (composite of any venous thromboembolism [VTE], any bleeding, and mortality) associated with anti-Xa monitoring in the 30 days following enoxaparin initiation for VTE prophylaxis.

DESIGN

Retrospective cohort study.

SETTING

Hospital within an academic healthcare system.

PATIENTS

Propensity score-matched hospitalized adults receiving enoxaparin for VTE prophylaxis.

INTERVENTION

Low-molecular-weight heparin anti-Xa monitoring.

MEASUREMENTS AND MAIN RESULTS

During the 13-month study period, a total of 6611 patients received enoxaparin for VTE prophylaxis, 301 in the anti-Xa monitored group and 6310 in the unmonitored group (4.6% received monitoring). The mean age was 52.9 years and 52% of patients were male. The mean body mass index was 31 kg/m2 and the mean creatinine clearance was 109 mL/min. Twenty percent of patients had active cancer. The most common indication for enoxaparin prophylaxis was hospitalization for medical illness (52%) followed by nonorthopedic surgery (37%). The adjusted odds ratio for the primary outcome comparing monitored to unmonitored patients was 1.26 (95% confidence interval, 0.75-2.11). None of the between-group differences in the individual components of the composite outcome were statistically significant.

CONCLUSIONS

Thirty-day clinical outcomes in patients receiving enoxaparin for VTE prophylaxis were not improved by anti-Xa monitoring. Our results support current evidence-based guideline recommendations against anti-Xa monitoring for patients receiving enoxaparin for VTE prophylaxis.

The effect of heparins on plasma concentration of heparin-binding protein: a pilot study

Background

Neutrophil-derived heparin-binding protein (HBP) plays a role in the pathophysiology of impaired endothelial dysfunction during inflammation. HBP has been suggested as a predictor of organ dysfunction and disease progression in sepsis. We investigated the effects of heparins on plasma concentrations of HBP in patients undergoing surgery.

Methods

We studied three groups of patients receiving heparins during or after surgery. The vascular surgery group received 3000-7500 U, whereas the cardiac surgery group received 27 500-40 000 U. After major general surgery, the third group received 5000 U of low-molecular-weight heparin (LMWH) subcutaneously. Serial plasma HBP concentrations were measured after these treatments with two different methods: Axis-Shield ELISA and Joinstar FIC-Q100. In addition, plasma myeloperoxidase and syndecan-1 were measured in the cardiac surgery group.

Results

During vascular surgery, heparin induced a six-fold increase in HBP within 2 min, from 3.6 (2.4-5.4) to 21.4 (9.0-35.4) ng ml-1 (P<0.001). During cardiac surgery, the higher dose of heparin elevated HBP concentrations from 5.3 (2.7-6.1) to 48.7 (38.4-70.1) ng ml-1 (P<0.0001) within 3 min. Patients receiving LMWH showed an increase from a baseline of 5.7 (3.7-12.1) ng ml-1 to a peak HBP concentration of 14.8 (9.5-18.1) ng ml-1 (P<0.0001) after 3 h. Plasma concentrations of myeloperoxidase, but not syndecan-1, also responded with a rapid increase after heparin. There was a strong correlation between the two methods for HBP analysis (r=0.94).

Conclusions

Plasma concentrations of HBP increased rapidly and dose-dependently after heparin administration. Subcutaneous administration of LMWH increases plasma HBP, but to a lesser degree.

Clinical trial registration

ClinicalTrials.gov identifier: NCT04146493.

Periprocedural Bridging Therapy in Patients With Mechanical Heart Valves

Mechanical heart valves (MHVs) are thrombogenic and require lifelong anticoagulation with vitamin K antagonists (VKAs) such as warfarin. Periprocedural bridging with unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH) aims to reduce the risk of thromboembolic events in patients. Currently, there are no definitive class I recommendations for anticoagulation management in patients with MHVs. In this report, we present the case of a 77-year-old female who was perioperatively bridged with enoxaparin and subsequently developed an acute thrombus.

Challenges in Treating Extensive Deep Vein Thrombosis with Severe Thrombocytopenia in Patients with Antiphospholipid Syndrome-A Follow-up of 2 Years

Thrombocytopenia is one of the most common manifestations of antiphospholipid syndrome (APS). There is little evidence or definitive guidelines regarding the treatment of APS with thrombocytopenia. We describe a patient with APS and moderate-to-severe thrombocytopenia and the challenges of balancing anticoagulation with thrombocytopenia. A 19-year-old male patient presented with right lower limb swelling to the emergency department with a history of gradually worsening right leg swelling for 1 week and was diagnosed with right leg proximal deep vein thrombosis. Ultrasound Doppler of the right lower limb revealed complete venous thrombosis from the level of the popliteal vein to the distal superficial femoral vein. Subsequently, he was found to have triple-positive APS and moderate-to-severe immune thrombocytopenia, with a platelet count nadir of 31 × 10 to the ninth power/L. He was started on anticoagulation with warfarin. The severe thrombocytopenia was not treated with immunosuppressants and the platelets fluctuated in the range of moderate-to-severe thrombocytopenia but did not develop any rethrombotic or bleeding events. His platelets varied from 31 × 10 to the ninth power/L to 106 × 10 to the ninth power/L. This case report demonstrates that it may be safe to hold off treatment for thrombocytopenia in APS, even in cases of severe thrombocytopenia. Treatment with immunosuppressants may be instituted only when platelet levels fall below 20 × 10 to the ninth power/L or when there is clinically significant bleeding, as in primary immune thrombocytopenia.

Low-molecular-weight heparin is associated with lower venous thromboembolism events than factor Xa inhibitors in patients with severe blunt trauma: a cohort study from the Trauma Quality Improvement Program

BACKGROUND

Venous thromboembolism (VTE), including deep venous thrombosis (DVT) and pulmonary embolism (PE), is a common complication of major trauma. Pharmacological VTE prophylactics are widely used, and low-molecular-weight heparin (LMWH) is recommended. Factor Xa inhibitors are increasingly being used for VTE prophylaxis in both medical and surgical patients. Evidence comparing LMWH and factor Xa inhibitors as VTE prophylactics for severe blunt trauma is lacking. This study aims to compare the efficacy and safety of factor Xa inhibitors and LMHW in VTE prophylaxis.

MATERIALS AND METHODS

Patients with severe blunt trauma who received LMWH or a factor Xa inhibitor for VTE prophylaxis in the Trauma Quality Improvement Program between 2017 and 2019 were included. The comparison was performed after using propensity score matching. The outcomes included mortality and incidence of DVT, PE, post-prophylactics haemorrhage control procedures and length of stay.

RESULTS

After 2:1 propensity score matching, 1128 patients ( n =752, LMHW group; n =376, factor Xa inhibitor group) were included in the analysis. Patients in the LMWH group had fewer VTE events than those in the factor Xa inhibitor group (DVT, 3.7% vs. 7.2%, P =0.013; PE, 0.4% vs. 3.2%, P <0.001). VTE risk was higher in the factor Xa group (DVT: odds ratio, 1.97; 95% CI, 1.12-3.44; P =0.018 and PE: odds ratio, 9.65; 95% CI, 2.91-44.12; P =0.001). The mortality rate was higher in the LMWH group; however, there was no significant difference (4.0% vs. 1.9%; P =0.075). The difference in the risk of undergoing haemorrhage control surgery after VTE prophylaxis between both groups was insignificant (0.3% vs. 0.0%; P =0.333).

CONCLUSIONS

LMWH was associated with a lower risk of VTE than factor Xa inhibitors in patients with severe blunt trauma. The mortality rate was higher in the LMWH group; however, there was no statistically significant difference observed.

Projected impact of guidelines on incidence of venous thromboembolism after cesarean delivery in the United States

BACKGROUND

There is large variation in recommended for postcesarean delivery venous thromboembolism (VTE) prophylaxis among commonly used guidelines.

OBJECTIVES

The aim of the study is to estimate implications of adoption of VTE prevention guidelines for rates of receipt of VTE prophylactic therapy and VTE following cesarean delivery (CD).

METHODS

We used administrative data from the 2015-2019 Nationalwide Readmissions Database to identify cesarean deliveries and rates of VTE stratified by risk factors, leading to different prophylactic strategies based on several national guidelines. We used input parameters from the literature to construct a hybrid decision tree/Markov model to project the implications of guideline adoption on VTE rates for the first 6 weeks following delivery.

RESULTS

Adoption of either the 2011 American College of Obstetricians and Gynecologists or the 2018 American Society for Hematology guidelines would avert a relatively small proportion (5%) of VTE cases, albeit with little low-molecular-weight heparin (LMWH) use (87-115 doses per 1000 CD patients). The 2012 American College of Chest Physicians guidelines were predicted to be more effective at averting VTE (21.2% reduction) with more LMWH usage (570 doses per 1000 deliveries). The 2015 Royal College of Obstetricians and Gynaecologists guidelines and universal use of 6 weeks of LMWH would avert an even larger proportion of cases (37.4% and 57.6%, respectively), at the cost of much higher rates of LMWH utilization (7233 doses per 1000 patients and 38 648 doses per 1000 patients).

CONCLUSIONS

Adoption of different guidelines would have notably varying implications for clinical practice and potential for alteration of the national rate of VTE following CD.

Efficacy and Safety Study of Low-Molecular-Weight Heparin and Fondaparinux Sodium After Hip Arthroplasty: A Retrospective Cohort Study

Background

Low molecular heparin(LMWH) and sodium sulfadiazine heparin(FPX) are commonly used to prevent deep vein thrombosis(DVT) after total hip arthroplasty(THA). In this study, we compared the role of these drugs in preventing DVT after THA.

Methods

Patients who underwent unilateral THA at the Sixth Affiliated Hospital of Xinjiang Medical University from April 2020 to December 2022 were retrospectively analyzed for inclusion in this study. According to the anticoagulant drugs used, the patients were divided into LMWH group (n=106) and FPX group (n=97). Changes in perioperative coagulation-related indices, hemoglobin, blood loss And the postoperative complications.

Results

The preoperative indexes of the two groups of patients, the difference was not statistically significant (P>0.05); the indexes of Intraoperative blood loss, Visible blood loss, Hidden blood loss, and Total blood loss of the two groups of patients were compared, and the difference was not significant (P>0.05); PT activity and INR in the LMWH group were significantly lower than those in the FPX group on the 1st and 5th postoperative days, and the differences were significant (P<0.05); Platelets, Hemoglobin, Hematocrit, D-dimer, and Fibrinogen were compared between the two groups on the 1st and 5th postoperative days, and the differences were not significant (P<0.05). The differences were not significant (P>0.05). The differences in blood transfusion rate and blood volume between the two groups were not significant (P>0.05); the total hospitalization cost of the LMWH group was significantly lower than that of the FPX group, and the difference was significant (P<0.05); and the differences in the incidence of postoperative complications between the two groups were not significant (P>0.05).

Conclusion

In this study, we found that the efficacy and safety of FPX and LMWH in preventing VTE after THA were basically the same, and the total cost of hospitalization in the LMWH group was significantly lower than that in the FPX group; however, due to the limited inclusion of the sample size, high-quality, large-sample, long-term follow-up clinical studies are necessary.

Low-molecular-weight heparin in thrombophilic women receiving in vitro fertilization/intracytoplasmic sperm injection: A meta-analysis

INTRODUCTION

This meta-analysis aimed to evaluate the efficacy and safety of low-molecular-weight heparin (LMWH) on pregnancy outcomes in thrombophilic women receiving in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI).

MATERIAL AND METHODS

A systematic literature search of PubMed, EMBASE, the Cochrane Library, and China National Knowledge Infrastructure was performed to identify randomized controlled trials (RCTs) comparing LMWH with no treatment or placebo published from database inception until February 19, 2023. Primary outcomes were the clinical pregnancy rate and implantation rate, and secondary outcomes were the live birth rate, miscarriage rate, and the risk of bleeding events. The certainty of the evidence was rated using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system. Meta-analysis was conducted using STATA 14.0.

RESULTS

Five RCTs involving 1094 thrombophilic women receiving IVF/ICSI were finally included. Administration of LMWH was associated with statistically higher clinical pregnancy rate (4 RCTs, risk ratio [RR] 1.50, 95% confidence interval [CI] 1.23-1.82, p < 0.001, low certainty evidence), implantation rate (5 RCTs, RR 1.49, 95% CI 1.25-1.78, p < 0.001, very low certainty evidence), and live birth rate (2 RCTs, RR 2.15, 95% CI 1.60-2.89, p < 0.001, very low certainty evidence), but with statistically lower miscarriage rate (2 RCTs, RR 0.36, 95% CI 0.15-0.86, p = 0.021, very low certainty evidence). However, using LMWH was linked to a higher risk of bleeding events (2 RCTs, RR 2.36, 95% CI 1.49-3.74, p < 0.001, very low certainty evidence).

CONCLUSIONS

Very low certainty evidence suggests that administration of LMWH may benefit pregnancy outcomes in thrombophilic women receiving IVF/ICSI treatment, although it may also increase the risk of bleeding events. However, before putting our findings into practice, healthcare professionals should conduct an in-depth evaluation of the available evidence and specific patient situations. Furthermore, due to the low methodological quality of the included studies, more high-quality studies are needed to validate our findings in the future.

Management of an unintentional enoxaparin overdose: A case report and literature review

PURPOSE

The aim of this article is to describe a case in which protamine was used for a low-molecular-weight heparin (LMWH) overdose and present an up-to-date review of the literature on the management of LMWH overdose in adults.

SUMMARY

An unintentional administration of enoxaparin 900 mg occurred in a 73-year-old man with coronavirus disease 2019-related pulmonary embolism. Management of the overdose included a protamine bolus followed by an infusion. Anti-factor Xa levels and activated partial thromboplastin time were monitored. Anti-factor Xa levels declined in a linear fashion irrespective of protamine administration. No bleeding or further thrombotic complications occurred in the patient. A review of the literature revealed that the optimal strategy to treat an LMWH overdose is unknown, with treatment of overdoses ranging from clinical observation to aggressive protamine dosing in reported cases. Although protamine effectively neutralizes unfractionated heparin, it is unable to completely reverse LMWH activity and has variable effects on laboratory measures of LMWH anticoagulant activity.

CONCLUSION

The current case report provides additional data to previous literature suggesting that protamine may have a limited effect in decreasing anti-factor Xa levels in LMWH overdose. Continued reporting on the management of LMWH overdoses is warranted to clarify the optimal treatment strategy.

Safety and comparative efficacy of initiating low-molecular-weight heparin within 24 hours of injury or surgery for venous thromboembolism prophylaxis in patients with spinal cord injury: a prospective TRACK-SCI registry study

OBJECTIVE

Venous thromboembolism (VTE) following traumatic spinal cord injury (SCI) is a significant clinical concern. This study sought to determine the incidence of VTE and hemorrhagic complications among patients with SCI who received low-molecular-weight heparin (LMWH) within 24 hours of injury or surgery and identify variables that predict VTE using the prospective Transforming Research and Clinical Knowledge in SCI (TRACK-SCI) database.

METHODS

The TRACK-SCI database was queried for individuals with traumatic SCI from 2015 to 2022. Primary outcomes of interest included rates of VTE (including deep vein thrombosis [DVT] and pulmonary embolism [PE]) and in-hospital hemorrhagic complications that occurred after LWMH administration. Secondary outcomes included intensive care unit and hospital length of stay, discharge location type, and in-hospital mortality.

RESULTS

The study cohort consisted of 162 patients with SCI. Fifteen of the 162 patients withdrew from the study, leading to loss of data for certain variables for these patients. One hundred thirty patients (87.8%) underwent decompression and/or fusion surgery for SCI. DVT occurred in 11 (7.4%) of 148 patients, PE in 9 (6.1%) of 148, and any VTE in 18 (12.2%) of 148 patients. The analysis showed that admission lower-extremity motor score (p = 0.0408), injury at the thoracic level (p = 0.0086), admission American Spinal Injury Association grade (p = 0.0070), and younger age (p = 0.0372) were significantly associated with VTE. There were 3 instances of postoperative spine surgery-related bleeding (2.4%) in the 127 patients who had spine surgery with bleeding complication data available, with one requiring return to surgery (0.8%). Thirteen (8.8%) of 147 patients had a bleeding complication not related to spine surgery. There were 2 gastrointestinal bleeds associated with nasogastric tube placement, 3 cases of postoperative non-spine-related surgery bleeding, and 8 cases of other bleeding complications (5.4%) not related to any surgery.

CONCLUSIONS

Initiation of LMWH within 24 hours was associated with a low rate of spine surgery-related bleeding. Bleeding complications unrelated to SCI surgery still occur with LMWH administration. Because neurosurgical intervention is typically the limiting factor in initializing chemical DVT prophylaxis, many of these bleeding complications would have likely occurred regardless of the protocol.

Heparin-induced thrombocytopenia associated with low-molecular-weight heparin: clinical feature analysis of cases and pharmacovigilance assessment of the FAERS database

Background: Unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH) are commonly used anticoagulants for the management of arterial and venous thromboses. However, it is crucial to be aware that LMWH can, in rare cases, lead to a dangerous complication known as heparin-induced thrombocytopenia (HIT). The objective of this study was to evaluate the pharmacovigilance and clinical features of HIT associated with LMWH, as well as identify treatment strategies and risk factors to facilitate prompt management. Methods: We extracted adverse event report data from the FDA Adverse Event Reporting System (FAERS) database for pharmacovigilance assessment. Case reports on LMWH-induced thrombocytopenia dated up to 20 March 2023 were collected for retrospective analysis. Results: Significantly elevated reporting rates of HIT were shown in adverse event (AE) data of LMWHs in the FAERS database, while tinzaparin had a higher proportional reporting ratio (PRR) and reporting odds ratio (ROR) than other LMWHs, indicating a greater likelihood of HIT. Case report analysis indicated that a total of 43 patients showed evidence of LMWH-induced thrombocytopenia with a median onset time of 8 days. Almost half of the events were caused by enoxaparin. LMWHs were mainly prescribed for the treatment of embolism and thromboprophylaxis of joint operation. Patients with a history of diabetes or surgery appeared to be more susceptible to HIT. Clinical symptoms were mostly presented as thrombus, skin lesion, and dyspnea. Almost 90% of the patients experienced a platelet reduction of more than 50% and had a Warkentin 4T score of more than 6, indicating a high likelihood of HIT. In all patients, LMWHs that were determined to be the cause were promptly withdrawn. Following the discontinuation of LMWHs, almost all patients were given alternative anticoagulants and eventually achieved recovery. Conclusion: LMWH-induced thrombocytopenia is rare but serious, with increased risk in patients with diabetes or a surgical history. Prompt recognition and management are crucial for the safe use of LMWHs.

Update on Anticoagulation Strategies in Patients with ECMO-A Narrative Review

The use of extracorporeal membrane oxygenation (ECMO) has recently increased exponentially. ECMO has become the preferred mode of organ support in refractory respiratory or circulatory failure. The fragile balance of haemostasis physiology is massively altered by the patient's critical condition and specifically the aetiology of the underlying disease. Furthermore, an application of ECMO conveys another disturbance of haemostasis due to blood-circuit interaction and the presence of an oxygenator. The purpose of this review is to summarise current knowledge on the anticoagulation management in patients undergoing ECMO therapy. The unfractionated heparin modality with monitoring of activated partial thromboplastin tests is considered to be a gold standard for anticoagulation in this specific subgroup of intensive care patients. However, alternative modalities with other agents are comprehensively discussed. Furthermore, other ways of monitoring can represent the actual state of coagulation in a more complex fashion, such as thromboelastometric/graphic methods, and might become more frequent. In conclusion, the coagulation system of patients with ECMO is altered by multiple variables, and there is a significant lack of evidence in this area. Therefore, a highly individualised approach is the best solution today.

A Successful Pregnancy Outcome After Continued Surveillance of Lupus Anticoagulant Antibodies in a Patient With Recurrent Pregnancy Loss: A Case Report and Literature Review

Recurrent pregnancy loss (RPL) can be a devastating experience for individuals trying to have children. Various potential causes contribute to the multifactorial pathogenesis of RPL, including chromosomal anomalies, endocrine conditions, autoimmunity, thrombophilias, and infectious agents. Antinuclear antibodies (ANAs) offer an unspecific clue to the underlying autoimmune pathogenic etiology of RPL. This case details a 40-year-old female with a history of RPL, fibromyalgia, and ANA positivity, who spontaneously developed lupus anticoagulant antibodies during her second trimester of pregnancy. Although the recommended American Society of Reproductive Medicine (ASRM) diagnostic criteria for initiating a thrombophilia evaluation was not formally met, the patient's maintenance of low-molecular-weight heparin (LMWH) throughout her pregnancy may have contributed to the success of the pregnancy. When treating a patient with RPL, consideration of the comprehensive clinical picture should precede the need to strictly adhere to published criteria for using non-proven clinical interventions. A risk-benefit analysis ought to be considered when offering patients additional medications that may come with some risks but could significantly improve the chances of a successful clinical outcome, such as live birth. We aim to provide evidence to promote greater flexibility in guidelines so that a patient's unique autoimmune etiologies of RPL are not overlooked.

Abnormal uterine bleeding in anticoagulated patients by drug class: outcomes and management

BACKGROUND

Although abnormal uterine bleeding is a known adverse effect of anticoagulant drugs, true rates have not been widely studied. Society-backed recommendations and guidelines do not yet exist for prevention and management of abnormal uterine bleeding among anticoagulated patients.

OBJECTIVE

This study aimed to describe the incidence of new-onset abnormal uterine bleeding among patients receiving therapeutic anticoagulation by anticoagulant class, and to evaluate gynecologic treatment patterns.

STUDY DESIGN

We conducted an institutional review board-waived retrospective chart review of female patients aged 18 to 55 years and prescribed therapeutic anticoagulants, including vitamin-K antagonists, low-molecular-weight heparins, and direct oral anticoagulants, in an urban hospital network from January 2015 through January 2020. We excluded patients with antecedent abnormal uterine bleeding and menopause. Associations between abnormal uterine bleeding, anticoagulant class, and other covariates were evaluated with Pearson chi-square and analysis-of-variance tests. The primary outcome, abnormal uterine bleeding odds by anticoagulant class, was modeled with logistic regression. Age, antiplatelet therapy, body mass index, and race were included in our multivariable model. Secondary outcomes included emergency department visits and treatment patterns.

RESULTS

Of the 2479 patients who met the inclusion criteria, 645 were diagnosed with abnormal uterine bleeding after initiating therapeutic anticoagulation. After adjusting for age, race, body mass index, and concurrent use of antiplatelet therapy, those receiving all 3 classes of anticoagulants had higher odds of experiencing abnormal uterine bleeding (adjusted odds ratio, 2.63; confidence interval, 1.70-4.08; P<.001), whereas those taking only direct oral anticoagulants had the lowest odds (adjusted odds ratio, 0.70; confidence interval, 0.51-0.97; P=.032), with vitamin-K antagonists as the reference group. Race other than White was associated with higher odds of abnormal uterine bleeding, as was lower age. The most common hormone therapies used among patients with abnormal uterine bleeding were levonorgestrel intrauterine devices (7.6%; 49/645) and oral progestins (7.6%; 49/645). Sixty-eight patients (10.5%; 68/645) had an emergency department visit for abnormal uterine bleeding; 29.5% (190/645) of patients received a blood transfusion; 12.2% (79/645) began any pharmacologic therapy for bleeding; and 18.8% (121/645) underwent any gynecologic procedure.

CONCLUSION

Abnormal uterine bleeding occurs frequently among patients on therapeutic anticoagulation. Incidence in this sample varied considerably by anticoagulant class and race; use of single-agent direct oral anticoagulation carried the lowest risk. Important sequelae such as bleeding-related emergency department visits, blood transfusions, and gynecologic procedures were common. Balancing bleeding and clotting risk in patients on therapeutic anticoagulation requires a nuanced approach and should involve collaborative management between hematologists and gynecologists.

Aspirin versus LMWH for VTE prophylaxis after orthopedic surgery

Low molecular weight heparin (LMWH) is often used to prevent perioperative venous thrombosis after surgery, but aspirin is also recommended by academics. Studies were searched in electronic databases until February 24, 2023. We performed a meta-analysis to evaluate the safety and efficacy of aspirin and LMWH for venous thromboembolism (VTE) prophylaxis in patients after orthopedic surgery. The outcomes were death from any causes, deep vein thrombosis (DVT), pulmonary embolism (PE), etc. This study was registered with INPLASY, number 202320117. Six randomized controlled trials enrolled 13,851 patients with postoperative joint surgery. The risk of DVT was comparable between the two groups when aspirin was combined with mechanical devices (RR 0.61 [95% CI 0.27-1.39], I² = 62%, P = 0.24). No significant differences in all cause death, PE, wound infection, and wound complication were found between the aspirin and LMWH groups. In this meta-analysis, the mortality rate was comparable between the aspirin and LMWH groups. However, aspirin alone had a higher risk of DVT than LMWH. Based on the results of this meta-analysis, we suggest aspirin combined with mechanical devices for VTE prophylaxis in patients after orthopedic surgery.

Treatment of Cancer-Associated Thrombosis: Recent Advances, Unmet Needs, and Future Direction

Cancer-associated thrombosis, with the incidence rising over the years, is associated with significant morbidity and mortality in patients with cancer. Recent advances in the treatment of cancer-associated venous thromboembolism (VTE) include the introduction of direct oral anticoagulants (DOACs), which provide a more convenient and effective option than low-molecular-weight heparin (LMWH). Nonetheless, important unmet needs remain including an increased risk of bleeding in certain patient subgroups such as those with gastroesophageal cancer, concerns about drug-drug interactions, and management of patients with severe renal impairment. Although DOACs are more convenient than LMWH, persistence can decline over time. Factor XI inhibitors have potential safety advantages over DOACs because factor XI appears to be essential for thrombosis but not hemostasis. In phase II trials, some factor XI inhibitors were superior to enoxaparin for the prevention of VTE after knee replacement surgery without increasing the risk of bleeding. Ongoing trials are assessing the efficacy and safety of factor XI inhibitors for the treatment of cancer-associated VTE.

Low-molecular-weight heparin therapy reduces 28-day mortality in patients with sepsis-3 by improving inflammation and coagulopathy

Background and aim

Sepsis is a syndromic response to infection and is associated with high mortality, thus imposing a significant global burden of disease. Although low-molecular-weight heparin (LMWH) has been recommended to prevent venous thromboembolism, its anticoagulant and anti-inflammatory effects in sepsis remain controversial. Owing to the modification of the Sepsis-3 definition and diagnostic criteria, further evaluation of the efficacy and benefit population of LMWH is required.

Methods

We performed a retrospective cohort study to assess whether LMWH improved the inflammation, coagulopathy, and clinical outcomes against Sepsis-3 and to identify the target patients. All patients diagnosed with sepsis at the First Affiliated Hospital of Xi'an Jiaotong University (the largest general hospital in northwest China) from January 2016 to December 2020 were recruited and re-evaluated using Sepsis-3 criteria.

Results

After 1:1 propensity score matching, 88 pairs of patients were categorized into the treatment and control groups based on subcutaneous LMWH administration. Compared with the control group, a significantly lower 28-day mortality was observed in the LMWH group (26.1 vs. 42.0%, p = 0.026) with a comparable incidence of major bleeding events (6.8 vs. 8.0%, p = 0.773). Cox regression analysis showed that LMWH administration was the independent protective factor for septic patients (aHR, 0.48; 95% CI, 0.29-0.81; p = 0.006). Correspondingly, the LMWH treatment group showed a significant improvement in inflammation and coagulopathy. Further subgroup analysis showed that LMWH therapy was associated with favorable outcomes in patients younger than 60 years and diagnosed with sepsis-induced coagulopathy (SIC), ISTH overt DIC, non-septic shock, or non-diabetics and in patients included in the moderate-risk group (APACHE II score 20-35 or SOFA score 8-12).

Conclusion

Our study results showed that LMWH improves 28-day mortality by improving inflammatory response and coagulopathy in patients meeting Sepsis-3 criteria. The SIC and ISTH overt DIC scoring systems can better identify septic patients who are likely to benefit more from LMWH administration.

Maternal and perinatal outcomes of low-dose aspirin plus low-molecular-weight heparin therapy on antiphospholipid antibody-positive pregnant women with chronic hypertension

Objectives

Positive antiphospholipid antibodies (aPLs) and chronic hypertension (CH) in pregnancy are important causes of maternal and neonatal morbidity and mortality. However, there are no relevant studies on the treatment of aPL-positive pregnant women with CH. This study aimed to determine the effect of low-dose aspirin (LDA) plus low-molecular-weight heparin (LMWH) on maternal and perinatal outcomes in persistently aPL-positive pregnant women with CH.

Methods

This study was performed at the First Affiliated Hospital of Dalian Medical University in Liaoning, China, from January 2018 to December 2021. Pregnant women diagnosed CH and persistently positive aPL who had no autoimmune disease such as systemic lupus erythematosus, antiphospholipid syndrome were recruited and divided into control group (LDA and LWMH were not used), LDA group (LDA was used) and LDA plus LMWH group (both LDA and LMWH were used) according to whether they use LDA and/or LMWH. A total of 81 patients were enrolled, including 40 patients in the control group, 19 patients in the LDA group, and 22 patients in the LDA plus LMWH group. The maternal and perinatal outcomes of LDA plus LMWH therapy were analysed.

Results

Compared with control group, the rate of severe preeclampsia in LDA group (65.00% vs. 31.58%, p = 0.016) and LDA plus LMWH group (65.00% vs. 36.36%, p = 0.030) had a statistically significant reduction. Compared with control group, the rate of fetal loss in LDA group (35.00% vs. 10.53%, p = 0.014) and LDA plus LMWH group (35.00% vs. 0.00%, p = 0.002) had a statistically significant reduction. Compared with control group, the rate of live birth in LDA group (65.00% vs. 89.74%, p = 0.048) and LDA plus LMWH group (65.00% vs. 100.00%, p = 0.002) had a statistically significant increased. Compared withcontrol group, the incidence of early-onset preeclampsia (47.50% vs. 36.84%, p = 0.008) and early-onset severe preeclampsia (47.50% vs. 13.64%, p = 0.001) in the LDA plus LMWH group decreased and were statistically different. Furthermore, we also found that LDA or LDA plus LMWH hadn't increase the rate of blood loss and placental abruption.

Conclusion

Both LDA and LDA combined with LMWH could decrease the incidence of severe preeclampsia, decrease the rate of foetal loss, increase the rate of live birth. However, LDA plus LWMH could reduce and delay the onset of severe preeclampsia, prolong the gestational age and increase the rate of full-term delivery, improve the maternal and perinatal outcomes.

The right time to measure anti-Xa activity in critical illness: pharmacokinetics of therapeutic dose nadroparin

Background

Peak anti-Xa activity of low-molecular-weight heparin nadroparin is measured 3 to 5 hours after subcutaneous injection. In critically ill patients, physiological changes and medical therapies may result in peak activities before or after this interval, possibly impacting dosing.

Objectives

The primary objective was to determine the percentage of critically ill patients with adequately estimated peak activities drawn 3 to 5 hours after subcutaneous administration of a therapeutic dose of nadroparin. Adequate was defined as a peak activity of ≥80% of the actual peak anti-Xa activity. If ≥80% of patients had adequately estimated peak activities in the 3- to 5-hour interval, measurement in this interval was regarded as acceptable. The secondary objective was to determine the pharmacokinetic profile of nadroparin.

Methods

In this single-center, prospective study, we evaluated anti-Xa activities in patients admitted to a general intensive care unit. After ≥4 equal doses of nadroparin, anti-Xa activity was measured according to a 12- to 24-hour sampling scheme.

Results

In 25 patients, anti-Xa activities drawn between 3 and 5 hours after administration ranged 80% to 100% of the actual peak activity. Compared to the threshold level of an adequate estimation in at least 20 patients (≥80%), measuring anti-Xa activities in the 3- to 5-hour interval is an acceptable method (1-tailed binomial test; P < .02). We found a large interindividual variability for nadroparin exposure (mean ± SD area-under-the-curve_0-12h, 10.3 ± 4.8 IU·h/mL) and delayed elimination (t_1/2 range, 4.0-120.9 hours) despite adequate renal function.

Conclusion

In critically ill patients, measuring anti-Xa activity in a 3- to 5-hour interval after subcutaneous injection of therapeutic nadroparin is an acceptable method to estimate the actual peak anti-Xa activity.

Perturbations in kinetics of the thrombin generation assay identify women at risk of preeclampsia in the first trimester and provide the rationale for a preventive approach

BACKGROUND

Activation of the coagulation system and increased thrombin generation have been implicated in the pathophysiology of preeclampsia, and this rationale supports the administration of low-molecular-weight heparin to prevent this syndrome in patients at risk. Yet, randomized trials of this prophylactic measure have yielded contradictory results. A possible explanation is that only a subset of patients with preeclampsia have excessive thrombin generation and would benefit from the administration of low-molecular-weight heparin. Therefore, the key questions are whether and when patients who subsequently develop preeclampsia present evidence of abnormal thrombin generation.

OBJECTIVE

This study aimed to determine (1) the kinetics of thrombin generation throughout gestation in women with a normal pregnancy and in those with early and late preeclampsia, and (2) the diagnostic performance of in vivo thrombin generation parameters to predict the development of preeclampsia.

STUDY DESIGN

This retrospective, nested case-control study was based on a prospective longitudinal cohort of singleton gestations. Cases comprised women who developed preeclampsia (n=49), and controls consisted of patients with a normal pregnancy (n=45). Preeclampsia was classified into early-onset (n=24) and late-onset (n=25). Longitudinal changes in the parameters of the thrombin generation assay (lag time, time to peak thrombin concentration, peak thrombin concentration, endogenous thrombin generation, and velocity index) throughout gestation were compared between the study groups, and normal pregnancy percentiles were derived from the control group. We tested whether a single parameter or a combination of parameters, derived from the kinetics of thrombin generation, could identify patients who subsequently developed preeclampsia. Time-related parameters <10th percentile were considered short, and concentration-related parameters >90th percentile were considered high.

RESULTS

(1) Patients who developed preeclampsia (early- and late-onset) had abnormal thrombin generation kinetics as early as 8 to 16 weeks of pregnancy; (2) patients with a combination of a short lag time and high peak thrombin concentration at 8 to 16 weeks of pregnancy had an odds ratio of 43.87 for the subsequent development of preeclampsia (area under the curve, 0.79; sensitivity, 56.8%; specificity, 92.7%; positive likelihood ratio, 7.76); (3) at 16 to 22 weeks of gestation, patients with a combination of a short lag time and a high velocity index had an odds ratio of 16 for the subsequent development of preeclampsia (area under the curve, 0.78; sensitivity, 62.2%; specificity, 92.5%; positive likelihood ratio, 8.29).

CONCLUSION

During early pregnancy, the thrombin generation assay can identify the subset of patients at a greater risk for the development of preeclampsia owing to accelerated and enhanced production of thrombin. This observation provides a rationale for testing the efficacy of low-molecular-weight heparin in this subset of patients. We propose that future research on the efficacy of low-molecular-weight heparin and other interventions targeting the coagulation system to prevent preeclampsia should be focused on patients with abnormal kinetics of thrombin generation.

Obesity as a Risk Factor in the Appearance of Haematomas Caused by Low-Molecular-Weight Heparin: A Cross-Sectional Study

Thromboembolic disease (TED) is an important health problem in Europe due to its high morbimortality. Pharmacological prevention is achieved with low-molecular-weight heparin (LMWH), among other strategies, which are supported by a high degree of evidence in the scientific literature. According to its safety data sheet, this injection produces local injuries at a rate of 0.1-1% after administration; however, these percentages are much lower than others reported in several studies focusing on LMWH (44-88%). This high incidence of injuries might be associated with procedural or individual variables. (1) Background: Among the most frequent side effects after the administration of LMWH are pain and haematomas (HMTs), which are influenced by obesity. We aimed to determine the relationship between abdominal skinfold (ASF) value and incidence of HMTs. In addition, I sought to determine how the risk of HMT changed with each mm increase in ASF. (2) Methods: A cross-sectional descriptive study developed in the hospital unit of orthopaedic and trauma surgery was conducted over one year. All participants in the sample were classified based on their ASF and the appearance and area of HMTs were assessed after the administration of enoxaparin. The STROBE checklist was used to evaluate the study. Descriptive statistical analysis and analysis of variance of non-parametric factors were carried out. (3) Results: In a sample of 202 participants (808 Clexane injections), more than 80% presented HMTs. More than 70% of the sample was overweight and more than 50% had an ASF > 36 millimetres (mm). (4) Conclusions: An ASF over 36 mm confers a higher risk of developing HMTs: with each mm increase in the ASF, the risk increases by 4%. Participants who are overweight or obese also present a higher risk of HMT, and these conditions correlate positively with the area of the HMTs. Providing education for the self-administration of the drug after discharge and information about the probability of suffering from local injuries in a more individualised way will lead to fewer primary care nursing consultations, more adherence to the antithrombotic treatment, and, as a consequence, a decrease in TED and health costs.

Anti-Factor Xa Level Monitoring for Enoxaparin Prophylaxis and Treatment in High-Risk Patient Groups

Description Monitoring anti-factor Xa levels is a controversial topic in the inpatient setting due to resource utilization and unclear conditional guideline recommendations regarding this practice. Enoxaparin dosing in certain high-risk patient populations such as those with low body weight, obesity, renal insufficiency, and pregnancy has not been determined. The objective of this review was to assess the safety and efficacy of enoxaparin monitoring via anti-factor Xa levels in high-risk patient populations. The PubMed database was searched for articles related to low-molecular-weight heparin monitoring. Randomized controlled trials and meta-analyses that evaluated the safety and efficacy of enoxaparin prophylaxis and treatment in patients with extremes of weight, renal insufficiency, and pregnancy were selected. Fourteen studies representing four high-risk population patient groups were included. Patients with extremes of weight or who were pregnant were found to have subtherapeutic anti-factor Xa levels due to the weight-based dosing of enoxaparin. Those with renal insufficiency were found to be accumulating enoxaparin, indicating the need for a lower dose. Studies have shown that monitoring may be required in specific high-risk patient groups. Dose adjustments based on anti-factor Xa levels can prevent adverse events associated with enoxaparin. Further research involving larger patient populations would be necessary to determine the clinical efficacy of enoxaparin monitoring with anti-factor Xa levels.

Practice Patterns of Antithrombotic Therapy during the Early Postoperative Course of Cardiac Surgery

BACKGROUND

The current practices regarding the management of antithrombotic therapy during the early postoperative course of cardiac surgery are not well described.

METHODS

An online survey with multiple-choice questions was sent to cardiac anesthesiologists and intensivists from France.

RESULTS

The response rate was 27% (n = 149), with 2/3 of the respondents having less than 10 years of experience. A total of 83% of the respondents reported using an institutional protocol for antithrombotic management. A total of 85% (n = 123) of the respondents regularly used low-molecular-weight heparin (LMWH) during the immediate postoperative course. For 23%, 38%, 9%, and 22% of the physicians, LMWH administration was initiated between the 4th and 6th hour, between the 6th and 12th hour, between the 12th and 24th hour, and on postoperative day 1, respectively. The main reasons for not using LMWH (n = 23) were a perceived increased risk of perioperative bleeding (22%), poor reversal compared with unfractionated heparin (74%), local habits and the refusal of surgeons (57%), and its overly complex management (35%). The modalities of LMWH use were widely varied among the physicians. Chest drains were mostly removed within 3 days of surgery with an unchanged dose of antithrombotic therapy. Regarding temporary epicardial pacing wire removal anticoagulation, 54%, 30%, and 17% of the respondents left the dose unchanged, suspended the anticoagulation, or lowered the anticoagulation dose, respectively.

CONCLUSION

LMWH was inconsistently used after cardiac surgery. Further research is warranted to provide high-quality evidence regarding the benefits and safety of LMWH use early after cardiac surgery.

The effects of heparin, aspirin, and maternal clinical factors on the rate of nonreportable cell-free DNA results: a retrospective cohort study

BACKGROUND

Technological advances in the analysis of cell-free DNA in maternal serum have allowed expanded prenatal screening possibilities for fetal aneuploidies. The sensitivity and positive predictive value of the assay are partly dependent on the amount of cell-free DNA present in maternal circulation. Thus, it is important to know what fetal and maternal factors influence the level of cell-free DNA in maternal circulation. Maternal heparin use has been associated with an increase in nonreportable cell-free DNA results because of a low fetal fraction in some, but not all, previous studies. In addition, there are likely additional factors that affect cell-free DNA that remain uncharacterized.

OBJECTIVE

This study aimed to determine whether heparins, low-dose aspirin, and maternal clinical factors affect the rate of nonreportable cell-free DNA testing results.

STUDY DESIGN

A retrospective cohort study was conducted using pregnant people receiving cell-free fetal DNA testing from January 1, 2014, to June 30, 2018. Data were collected on patient demographics, medical comorbidities, medication use, and cell-free DNA test results. Univariate and multivariate analyses were performed to determine which factors were independently associated with the rate of nonreportable results.

RESULTS

From an original sample of 1117 pregnant people, 743 met the inclusion criteria. Maternal weight (odds ratio, 1.02), heparin use (odds ratio, 12.06), aspirin use (odds ratio, 4.70), chronic hypertension (odds ratio, 5.26), pregestational diabetes mellitus (odds ratio, 2.46), and autoimmune disease (odds ratio, 3.59) were significantly associated with an increased rate of nonreportable results in the univariate analysis. Moreover, the association was present for maternal weight (odds ratio, 1.02), heparin use (odds ratio, 21.87),and aspirin use (odds ratio, 2.85) in the multivariate analysis.

CONCLUSION

The previously seen association between maternal heparin use and an increase in nonreportable cell-free DNA results was confirmed. Furthermore, there seems to be an increase in nonreportable results in pregnant people taking low-dose aspirin. Providers should consider the effect of these medications when counseling patients on prenatal genetic screening options.

Implementation of a pharmacological prophylaxis bundle to prevent obstetric-associated venous thromboembolism

PURPOSE

Venous thromboembolism (VTE) accounts for a significant proportion of pregnancy-related mortality. In response to a series of VTEs at our institution and in accordance with mounting medical evidence for increased assessment, we implemented a universal, standardized obstetric VTE risk assessment process during antepartum and postpartum admissions and corresponding pharmacological thromboprophylaxis, which extends into the postdischarge period to prevent pregnancy-associated VTE in our urban, safety-net population.

SUMMARY

This quality improvement (QI) project used the Institute for Healthcare Improvement's Model for Improvement. We analyzed data from chart audits, patient and pharmacy outreach, and electronic reports using statistical process control charts. A review of 407 charts showed an increase in the proportion of patients undergoing documented risk assessment from 0% to 80% (average of 61%) from July 2015 to June 2016. The average risk assessment rate increased from 61% to 98% from July 2016 through March 2021 after the screening was integrated into the electronic health record (EHR). Rate of receipt of recommended thromboprophylaxis during admission increased from an average of 85% before EHR integration to 94% after integration. The proportion of high-risk patients receiving prescriptions upon discharge increased from 7% before EHR integration to 87% after integration. We interviewed 117 patients by telephone, of whom 74% continued the medications at home.

CONCLUSION

An interprofessional team can achieve high rates of obstetric inpatient VTE risk assessment, pharmacological thromboprophylaxis initiation, and outpatient continuation using QI methodology.

Low Early Antifactor Xa Target Achievement Rate of Low-Molecular-Weight Heparin for Treating Venous Thromboembolism in Patients in Intensive Care

This study aimed to evaluate whether early antifactor Xa (anti-Xa) achieved the target range when venous thromboembolism (VTE) was treated with low-molecular-weight heparin (LMWH), based on body weight and renal function in patients treated in intensive care units (ICUs). Anti-Xa levels in patients treated with LMWH for VTE in ICU and medical wards between January 1, 2021, and June 30, 2022, were retrospectively assessed. The demographics, laboratory parameters, and early anti-Xa peak levels of patients were collected. All patients were followed up for 3 months to collect VTE recurrence/bleeding events. Univariate and multivariate linear regression analyses were used to identify the factors affecting anti-Xa levels. A total of 108 patients were enrolled in this study, including 70 patients in ICU and 38 patients on medical wards. The early anti-Xa level (0.36 vs 0.61 IU/mL, P < .001) and target achievement rate (21.4% vs 39.5%, P = .015) of patients in ICU were lower than those in medical wards. Multivariate linear regression showed that only antithrombin (AT) significantly affected anti-Xa levels in patients in ICU (β = 0.008, 95%CI 0.005 to 0.011, P < .001). There was no significant difference in VTE recurrence events (11.8% vs 7.5%, P = .628) and bleeding events (29.4% vs 17.0%, P = .304) between the early anti-Xa within-target group and the early anti-Xa below-target group. Low anti-Xa peak levels are common in patients in ICU. AT activity should be monitored when using LMWH in critically ill patients.

Evaluation of Low-Molecular-Weight Heparin for Treatment of Portal Vein Thrombosis in Liver Cirrhosis Patients

Background and Objectives: Even though low-molecular-weight heparin (LMWH), including dalteparin, has a critical role in portal vein thrombosis (PVT) treatment in liver cirrhosis (LC) patients, the predictive factors and the proper dose of dalteparin for PVT treatment and relapse have not yet been investigated. Materials and Methods: This retrospective study evaluated the records of LC patients receiving dalteparin from July 2013 to June 2019. The odds ratio (OR) and adjusted OR were calculated from univariate and multivariable analyses, respectively. Results: Among data from 121 patients, the overall recanalization rate of all patients was 66.1% (80 patients). No history of variceal bleeding (OR 4.6, 95% CI: 1.88-11.43) and the case of newly developed thrombus before dalteparin treatment (OR 3.2, 95% CI: 1.24-8.08) were predictive factors associated with increased treatment response. Relapse of PVT occurred in 32 out of 80 patients (40%) who showed a recanalization. The risk of relapse was 3.1-3.9 times higher in those who took more than three months or more than six months from the diagnosis of PVT to dalteparin treatment compared to those who took less than these durations, respectively. In the dosing regimen, patients with the kg-based dosing regimen showed 2.6 times better response than those with the fixed dosing regimen. However, no difference in bleeding complications was observed. Conclusion: In the dosing regimen, the kg-based regimen that was the same as the venous thromboembolism regimen was a better option for the efficacy and safety of dalteparin therapy. Additionally, when treating PVT in LC patients, careful monitoring is recommended for patients with predictive factors for treatment response and relapse of PVT.

Co-administration of tacrolimus and low molecular weight heparin in patients with a history of implantation failure and elevated peripheral blood natural killer cell proportion

AIM

To investigate the therapeutic effect of co-administration of tacrolimus (TAC) and low-molecular-weight heparin (LMWH) or LMWH only on pregnancy outcomes in the female with a history of implantation failure and elevated peripheral blood natural killer (pNK) cell proportion in frozen-thawed embryo transfer cycles.

METHODS

To evaluate the pregnancy parameters for 249 patients with ≥2 implantation failures and pNK cell proportion ≥12% by analyzing a retrospective observational cohort study. Sixty patients had received the co-administration TAC and LMWH (TAC & LMWH group), 85 others had only taken LMWH (LWMH group), and the rest did not take any particular drugs (control group).

RESULTS

The experimental finding indicated that the TAC & LMWH group and the LMWH group showed higher clinical pregnancy rates than the control group (p < 0.05), and TAC & LMWH group had a much higher live birth rate. According to the binary logistic regression analysis, the combination of TAC and LMWH was conducive to clinical pregnancy and live birth rate and reduced the possibility of miscarriage. It would not affect the result of spontaneous abortion and live birth, although the LMWH was only beneficial to clinical pregnancy. In addition, these findings were similar for these three groups' obstetrical and neonatal outcomes.

CONCLUSIONS

The combination of TAC and LMWH can improve clinical pregnancy and live birth rates and reduce the risk of spontaneous miscarriage in patients with a history of implantation failure and elevated pNK ratio. LMWH is also beneficial to clinical pregnancy.

Antithrombotic treatment for retinal vein occlusion: a systematic review and meta-analysis

BACKGROUND

Retinal vein occlusion (RVO) represents a common thrombotic disorder.

OBJECTIVES

In this meta-analysis, we evaluated the efficacy and safety of anticoagulant and antiplatelet therapy in RVO.

METHODS

MEDLINE and EMBASE were searched up to December 2021 for observational studies and randomized controlled trials including patients with RVO. Efficacy outcomes were best-corrected visual acuity improvement, recurrent RVO, fluorescein angiography improvement, cardiovascular events, and safety outcomes were major bleeding and intraocular bleeding.

RESULTS

A total of 1422 patients (15 studies) were included. Antiplatelet therapy was administered to 477 patients (13 studies), anticoagulant therapy to 312 patients (12 studies), and 609 (7 studies) patients received no antithrombotic treatment. The treatment duration ranged between 0.5 and 3 months. The median follow-up duration was 12 months. Best-corrected visual acuity improvement was reported in 58% of the patients (95% confidence interval [CI], 45%-69%) overall, 64% (95% CI, 58%-71%) in those on anticoagulant therapy, and 33% (95% CI, 21%-47%) in those on antiplatelet therapy. The rates of recurrent RVO was 11% (95% CI, 7%-17%), 7% (95% CI, 2%-19%), and 15% (95% CI, 8%-28%), respectively. The rate of recurrent RVO in untreated patients was 9% (95% CI, 6%-14%). The rate of major bleeding was 5% (95% CI, 3%-9%) overall, 4% (95% CI, 2%-9%) in those on anticoagulant therapy, and 7% (95% CI, 2%-23%) in those on antiplatelet therapy.

CONCLUSION

Anticoagulant therapy was associated with higher visual acuity improvement and fewer recurrent RVO events than antiplatelet therapy, at the cost of an acceptable proportion of bleeding complications.

Longitudinal D-Dimer Trajectories and the Risk of Mortality in Abdominal Trauma Patients: A Group-Based Trajectory Modeling Analysis

This study aimed to identify the long-term D-dimer trajectory patterns and their associations with in-hospital all-cause mortality in abdominal trauma patients. This is a retrospective cohort study of general adult abdominal trauma patients admitted to Jinling Hospital (Nanjing, China) between January 2010 and April 2020. Group-based trajectory modeling was applied to model D-dimer trajectories over the first 50 days post-trauma. A multivariable logistic regression was performed to estimate the associations between D-dimer trajectories and in-hospital all-cause mortality. A total of 309 patients were included. We identified four distinct D-dimer trajectories: group 1 (57.61%; "stable low"), group 2 (28.16%; "moderate-decline"), group 3 (8.41%; "high-rapid decline"), and group 4 (5.83%; "high-gradual decline"). The SOFA score (p = 0.005) and ISS (p = 0.001) were statistically higher in groups 3 and 4 than in groups 1 and 2. The LMWH and UFH did not differ between groups 3 and 4. Compared with the patients in group 1, only the patients in group 4 were at a higher risk of in-hospital all-cause mortality (OR = 6.94, 95% CI: 1.20-40.25). The long-term D-dimer trajectories post-trauma were heterogeneous and associated with mortality. An initially high and slowly-resolved D-dimer might function as the marker of disease deterioration, and specific interventions are needed.

Thromboprophylaxis in Pregnant Women with COVID-19: An Unsolved Issue

SARS-CoV-2 infection in pregnant women is of growing interest due to controversy over the use of antiplatelet and/or anticoagulant drugs during pregnancy and postpartum. Pregnant women are susceptible to develop severe forms of viral infections due to pregnancy-related immune alterations, changes in lung functions, and hypercoagulability. The association of pregnancy with SARS-CoV-2 infection can cause an increased incidence of thrombotic complications, especially in the case of patients with some genetic variants that favor inflammation and thrombosis. Compared to the general population, pregnant women may be at increased risk of thrombotic complications related to COVID-19. The lack of extensive clinical trials on thromboprophylaxis and extrapolating data from non-pregnant patients lead to major discrepancies in treating pregnant women with COVID-19. Currently, a multidisciplinary team should determine the dose and duration of prophylactic anticoagulant therapy for these patients, depending on the disease severity, the course of pregnancy, and the estimated due date. This narrative review aims to evaluate the protective effect of thromboprophylaxis in pregnant women with COVID-19. It is unknown at this time whether antiplatelet or anticoagulant therapy initiated at the beginning of pregnancy for various diseases (preeclampsia, intrauterine growth restriction, thrombophilia) offers a degree of protection. The optimal scheme for thromboprophylaxis in pregnant women with COVID-19 must be carefully established through an individualized decision concerning gestational age and the severity of the infection.

Edoxaban Versus Low-Molecular-Weight Heparin in Hospitalized COVID-19 Patients With Atrial Fibrillation

OBJECTIVE

During the first wave of the SARS-CoV-2 pandemic, management of anticoagulation therapy in hospitalized patients with atrial fibrillation (AF) was simplified to low-molecular-weight heparin (LMWH) followed by oral anticoagulation, mainly owing to the risk of drug-drug interactions. However, not all oral anticoagulants carry the same risk.

METHODS

Observational, retrospective, and multicenter study that consecutively included hospitalized patients with AF anticoagulated with LMWH followed by oral anticoagulation or edoxaban concomitantly with empirical COVID-19 therapy. Time-to-event (mortality, total bleeds, and admissions to ICU) curves, using an unadjusted Kaplan-Meier method and Cox regression model adjusted for potential confounders were constructed.

RESULTS

A total of 232 patients were included (80.3 ± 7.7 years, 50.0% men, CHA₂DS₂-VASc 4.1 ± 1.4; HAS-BLED 2.6 ± 1.0). During hospitalization, patients were taking azithromycin (98.7%), hydroxychloroquine (89.7%), and ritonavir/lopinavir (81.5%). The mean length of hospital stay was 14.6 ± 7.2 days, and total follow-up was 31.6 ± 13.4 days; 12.9% of patients required admission to ICU, 18.5% died, and 9.9% had a bleeding complication (34.8% major bleeding). Length of hospital stay was longer in patients taking LMWH (16.0 ± 7.7 vs 13.3 ± 6.5 days; P = .005), but mortality and total bleeds were similar in patients treated with edoxaban and those treated with LMWH followed by oral anticoagulation.

CONCLUSIONS

Mortality rates, arterial and venous thromboembolic complications, and bleeds did not significantly differ between AF patients receiving anticoagulation therapy with edoxaban or LMWH followed by oral anticoagulation. However, the duration of hospitalization was significantly lower with edoxaban. Edoxaban had a similar therapeutic profile to LMWH followed by oral anticoagulation and may provide additional benefits.

Low-molecular-weight heparin in addition to low-dose aspirin for preventing preeclampsia and its complications: A systematic review and meta-analysis

Background

In this systematic review, we aimed to investigate the efficacy and safety of adding low-molecular-weight heparin (LMWH) or unfractionated heparin to low-dose aspirin (LDA) started ≤16 weeks'gestation in the prevention of preeclampsia (PE) in high-risk women.

Methods

PubMed, Cochrane Library, Embase, and ClinicalTrials.gov databases were searched from their inception to April 2022 for randomized controlled trials (RCTs) that to determine whether the combined treatment of LMWH and LDA is better than single anticoagulant drugs in preventing PE and improving live birth rate of fetus in high-risk women with pregnancy ≤16 weeks. We also searched Embase, OVID MEDLINE and OVID MEDLINE in-process using the OVID platform.

Results

14 RCTs involving 1,966 women were found. The LMWH (or unfractionated heparin) and LDA groups included 1,165 wemen, and the LDA group included 960 women. The meta-analysis showed that the addition of LMWH to LDA reduced the risk of PE (RR: 0.59, 95% CI: 0.44-0.79, P < 0.05), small-for-gestational age (SGA, RR: 0.71, 95% CI: 0.52-0.97, P = 0.03), fetal and neonatal death (RR: 0.45, 95% CI: 0.23-0.88, P = 0.02) and gestational hypertension (RR: 0.47, 95% CI: 0.25-0.90, P = 0.02). It is worth emphasizing that LMWH (or unfractionated heparin) combined with LDA did not increase the risk of bleeding.

Conclusions

LMWH combined with LDA can effectively improve the pregnancy outcome of women with high risk factors for PE and its complications. Although this study showed that combined medication also did not increase the risk of bleeding, but such results lack the support of large sample size studies. The clinical safety analysis of LMWH combined with LDA in patients with PE should be more carried out.

Thromboembolic Events in Patients Undergoing Neoadjuvant Chemotherapy and Radical Cystectomy for Muscle-Invasive Bladder Cancer: A Study of Renal Impairment in Relation to Potential Thromboprophylaxis

Recent studies on patients with muscle-invasive bladder cancer (MIBC) undergoing neoadjuvant chemotherapy (NAC) have shown an association between NAC and thromboembolic events (TEE) prior to radical cystectomy (RC). Recent studies suggest that central venous access catheters (CVAs) may induce TEEs, and low-molecular-weight heparin (LMWH) has been mentioned as possible prophylaxis. However, other studies have shown a high incidence of decreased renal function in these patients. The purpose of this study was to determine the portion of MIBC patients with NAC-induced TEEs who had decreased preoperative renal function for whom LMWH potentially would not be beneficial as prophylaxis. We identified 459 cystectomized MIBC patients from two Swedish medical centers from 2009 to 2021. The inclusion criterion of cT2-T4aN0M0 resulted in 220 eligible patients, who were further divided into NAC-administered (n = 187) and NAC-eligible (n = 33), the tentative control group. Values of renal function before, during, and after each NAC cycle were retrospectively collected from individual medical records. Amongst the NAC-administered patients with TEE (n = 29), 41% (95% CI 23.5-61.1%) of patients had decreased renal function. Thus, a substantial portion of NAC-administered patients who developed TEEs had reduced renal function and would have been less likely to have benefited from renal clearance-dependent LMWH prophylaxis.

The effect of low-molecular-weight heparin on live birth rate of patients with unexplained early recurrent pregnancy loss: A two-arm randomized clinical trial

BACKGROUND

The effect of anticoagulant medication in unexplained early recurrent pregnancy loss (RPL) patients is controversial. This clinical trial evaluated the effect of low-molecular-weight heparin (LMWH) on pregnancy outcomes in these patients.

MATERIALS AND METHODS

The study was performed as a single-blind randomized clinical trial between 2016 and 2018. Samples were selected from patients who were referred to Avicenna RPL clinic with a history of at least two previously happened early unexplained miscarriages. The eligibility was defined strictly to select unexplained RPL patients homogenously. One hundred and seventy-three patients who got pregnant recently were allocated randomly into two groups LMWH plus low-dose aspirin treatment (Group A = 85) and low-dose aspirin treatment only (Group B = 88)) and were followed up till their pregnancy termination (delivery/abortion). A per-protocol analysis was carried out and all statistical tests were two-sided with a P < 0.05 significance level.

RESULTS

The live birth rates (LBRs) in Groups A and B were 78% and 77.1%, respectively, which did not show any statistically significant difference between the two groups, neither in rates nor in time of abortion. In subgroup analysis for polycystic ovary syndrome (PCOS) patients, the odds ratio for study outcome (intervention/control) was 2.25 (95% confidence interval: 0.65-7.73). There was no major adverse event whereas minor bleeding was observed in 18% of patients in Group A.

CONCLUSION

LMWH does not improve the LBR in unexplained RPL patients, however, it is recommended to evaluate its effect separately in PCOS patients.

Antitumor Activity of the Zinc Oxide Nanoparticles Coated with Low-Molecular-Weight Heparin and Doxorubicin Complex In Vitro and In Vivo

Various metal oxide nanomaterials have been widely used as carriers to prepare pH-sensitive nanomedicines to respond to the acidic tumor microenvironment promoting antitumor efficiency. Herein, we used zinc oxide nanoparticles (ZnO NPs) as metal oxide nanomaterial coated with low-molecular-weight heparin (LMHP) and doxorubicin (DOX) complex (LMHP-DOX) to prepare ZnO-LD NPs for controllable pH-triggered DOX release on the targeted site. Our results indicated that the released DOX from ZnO-LD NPs was pH-sensitive. The oxygen produced by ZnO-LD NPs in H₂O₂ solution was observed in in vitro experiment. The ZnO-LD NPs entered into both PC-3M and 4T1 tumor cells via clathrin-mediated endocytosis and micropinocytosis pathway. The intracellular reactive oxygen species (ROS) generated by ZnO-LD NPs could significantly increase the caspase 3/7 level, leading to tumor cell apoptosis. The in vitro and in vivo antitumor activity was confirmed in PC-3M and 4T1 cell lines or tumor-bearing mice models. The in vivo and in vitro tumor images via second-order nonlinearity of ZnO-LD NPs indicated that ZnO-LD NPs could penetrate deep into the tumor tissues. Therefore, the ZnO-LD NPs developed in our study could provide an efficient approach for the preparation of pH-sensitive nano delivery systems suitable for tumor therapy and imaging.

A Review of the Past, Present and Future of Cancer-associated Thrombosis Management

Venous thromboembolism (VTE) can have a significant impact on the management, quality of life and mortality of patients with cancer. VTE occurs in 5-20% of patients with cancer, and malignancy is associated with up to 25% of all VTE. It is the second leading cause of death in ambulatory patients with cancer who are receiving chemotherapy. Increased rates of cancer-associated thrombosis are attributed to improved patient survival, increased awareness, surgery, antineoplastic treatments and the use of central venous access devices. Many factors influence cancer-associated thrombosis risk and are broadly categorized into patient-related, cancer-related and treatment-related risks. Direct-acting oral anticoagulants have shown themselves to be at least as effective in preventing recurrent VTE in patients with cancer with symptomatic and incidental VTE. This has led to a change in treatment paradigms so that direct-acting oral anticoagulants are now considered first-line agents in appropriately selected patients. In this article, we review the prior and recent landmark studies that have directed the treatment of cancer-associated thrombosis, and discuss specific factors that affect management as well as future treatment considerations.

Enoxaparin versus Unfractionated Heparin for the Perioperative Anticoagulant Therapy in Patients with Mechanical Prosthetic Heart Valve Undergoing Non-Cardiac Surgery

Background and Objectives: Immediate postoperative anticoagulation regimens in patients with mechanical prosthetic valves undergoing non-cardiac surgery are clear only for unfractionated heparin (UH), whereas the few low-molecular-weight heparin (LMWH) trials available to date concern the use of Enoxaparin in general/orthopedic surgery. We performed a single-center real-world data study comparing the efficacy and safety of LMWH—Enoxaparin (E)— and UH during the perioperative period in non-cardiac surgical procedures in patients with mechanical prosthetic valve replacement in the mitral, aortic, or tricuspid positions. Materials and Methods: We enrolled 380 patients, who received E or UH together with oral anticoagulation with antivitamin K (acenocoumarol) until they achieved an optimal International Normalized Ratio (INR). Objective assessment of E efficacy included the following: normal value for all the parameters of ultrasound prosthetic functioning, no early thrombosis of the prosthesis, and rapid achievement of target INR with a decreased period of subcutaneous anticoagulation. Subjective assessment included the following: clinical improvement with decreased immobilization and in-hospital stay, fewer gluteal ulcerations, and fewer postoperative depression and anxiety episodes. Results: Comparing with UH, anticoagulation with E was more effective (p < 0.0001 and p = 0.02). The probability of death was smaller in the E group compared with the UH group. No major hemorrhagic event was reported. Mild bleeding episodes and thrombocytopenia were more common in the UH group. Patient’s compliance and quality of life were better with E due to shortened hospitalization, decreased need for testing of coagulation (every 6 h for UH), better dosing (SC every 12 h for E versus continuous infusion for UH), shortened immobilization during the immediate postoperative period with subsequent improvement in the psychological status, as well as due to lack of significant side effects. Conclusions: Taking into consideration the improved efficiency and safety, as well as all the supplementary advantages, such as no need for anticoagulation monitoring, the ease of administration, and reduced duration of hospitalization, E should be seen as an attractive alternative for anticoagulation which deserves further investigation.

Current Venous Thromboembolism Chemoprophylaxis Practices After Surgery for Inflammatory Bowel Diseases

Recent events shed light on the high risk of venous thromboembolism (VTE) in patients with inflammatory bowel disease and the importance of prophylaxis in such patients. Protocols within the electronic medical record help improve compliance with VTE prophylaxis.

Prevention of Deep Vein Thrombosis by Panax Notoginseng Saponins Combined with Low-Molecular-Weight Heparin in Surgical Patients

OBJECTIVE

To evaluate the efficacy of deep vein thrombosis (DVT) prevention among real-world surgical inpatients who received panax notoginseng saponins (PNS) combined with low-molecular-weight heparin (LMWH).

METHODS

A prospective cohort study was conducted among surgical patients between January 2016 and November 2018 in Xuanwu Hospital, Capital Medical University, Beijing, China. Participants received LMWH alone or PNS combined with LMWH for preventing DVT. The primary outcome was incidence of lower extremity DVT, which was screened once a week. Participants in the LMWH group were given LMWH (enoxaparin) via hypodermic injection, 4000-8000 AxalU once daily. Participants in the exposure group received PNS (Xuesaitong oral tablets, 100 mg, 3 times daily) combined with LMWH given the same as LMWH group.

RESULTS

Of the 325 patients screened for the study, 281 participants were included in the final analysis. The cohort was divided into PNS + LMWH group and LMWH group with 134 and 147 participants, respectively. There was a significant difference of DVT incidence between two groups (P=0.01), with 21 (15.7%) incident DVT in the PNS + LMWH group, and 41 (27.9%) incident DVT in the LMWH group. Compared with participants without DVT, the participants diagnosed with DVT were older and had higher D-dimer level. The multivariate logistic regression model showed a significant lower risk of incident DVT among participants in the PNS + LMWH group compared with the LMWH group (odds ratio 0.46, 95% confidence interval, 0.25-0.86). There were no significant differences in thromboelaslography values (including R, K, Angle, and MA) and differences in severe bleeding between two groups. No symptomatic pulmonary embolism occurred during the study.

CONCLUSION

Combined application of PNS and LMWH can effectively reduce the incidence of DVT among surgical inpatients compared with LMWH monotherapy, without increased risk of bleeding.

Investigations of the effectiveness of heparin variants as inhibitors of histones

BACKGROUND

Extracellular histones exert cytotoxic and procoagulant effects which contribute to immunothrombosis in vascular diseases such as sepsis. Heparin has been shown to neutralize the pathologic effects of histones in vitro and in animal models.

OBJECTIVES

To compare the effectiveness of unfractionated heparin (UFH), low-molecularweight heparin (LMWH), Vasoflux (lacks anticoagulant activity), and fondaparinux in neutralizing the cytotoxic and procoagulant activities of histones METHODS: Binding affinities between heparin variants and histone subunits were determined by Bio-layer Interferometry. The ability of heparin variants to diminish the cytotoxic and procoagulant effects of histones was studied by treating endothelial cells or monocytic THP-1 cells with histones ± heparin variants.

RESULTS

Unfractionated heparin, LMWH, and Vasoflux bind histone subunits with high affinities (Kd <1 pM-66.7 nM) whereas fondaparinux exhibited a low affinity (Kd of 3.06 µM-81.1 mM). UFH, LMWH, and Vasoflux neutralize histone-mediated cytotoxicity as well as monocytic procoagulant activity (as assessed by cell surface tissue factor and phosphatidylserine). In contrast, fondaparinux has no effect on these activities. All four heparin variants reverse histone-mediated impairment of APC generation in a dose-dependent manner.

CONCLUSIONS

The ability of heparin to neutralize the cytotoxic and procoagulant effects of histones require heparin fragments >1.7 kDa and is independent of the antithrombin-binding pentasaccharide. In contrast, the ability of heparin to neutralize histone-mediated impairment of APC generation is independent of size and anticoagulant activity. These findings suggest that heparin variants may have differential therapeutic potential in vascular diseases associated with elevated levels of histones.

Low-Molecular-Weight Heparin Versus Aspirin in Early Management of Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

Objectives

To evaluate the difference between low-molecular-weight heparin (LMWH) and aspirin in preventing early neurological deterioration (END) and recurrent ischemic stroke (RIS), post-recovery independence, and safety outcomes in acute ischemic stroke.

Materials and Methods

We performed systematic searches of the PubMed, Embase, Web of Science, and Cochrane Library databases for full-text articles of randomized controlled trials (RCTs) of LMWH vs. aspirin in the early management of acute ischemic stroke. Information on study design, eligibility criteria, baseline information, and outcomes was extracted. Synthesized relative risks (RRs) with 95% confidence intervals (CIs) are used to present the differences between the two treatments based on fixed-effects models.

Results

Five RCTs were retrieved from the online databases. The results showed no significant difference in efficacy outcomes between the two groups among unselected patients. Subgroup analysis showed that LMWH was significantly related to a lower incidence of END events [relative risk (RR): 0.44, 95% confidence interval (CI): 0.35-0.56] and reduced occurrence of RIS during treatment (OR: 0.34, 95% CI: 0.16-0.75) in non-cardioembolic stroke. LMWH significantly increased the number of patients with a modified Rankin scale (mRS) score of 0-1 at 6 months in patients with large-artery occlusive disease (LAOD) (RR: 0.50, 95% CI: 0.27-0.91). LMWH had a similar effect on symptomatic intracranial hemorrhage (sICH) and major extracranial hemorrhage during treatment to that of aspirin, except that LMWH was related to an increased likelihood of extracranial hemorrhage.

Conclusions

In patients with acute non-cardioembolic ischemic stroke, especially that with large-artery stenosis, LMWH treatment significantly reduced the incidence of END and RIS, and improved the likelihood of independence (mRS 0-1) at 6 months compared with those with aspirin treatment. LMWH was related to an increased likelihood of extracranial hemorrhage among all patients; however, the difference in major extracranial hemorrhage and sICH was not significant. Choosing the appropriate patients and paying attention to the start time and duration of treatment are very important in the use of anticoagulation.

Systematic Review Registration

http://www.crd.york.ac.uk/PROSPERO, identifier CRD42020185446.

Dipyridamole does not have any additive effect on the prevention of COVID-19 coagulopathy

OBJECTIVE

Severe acute respiratory syndrome (SARS) coronavirus 2 (SaRS-Cov-2) associated respiratory disease (COVID-19), announced as a pandemic, is a multisystem syndrome. SARS-CoV-2 directly infects and damages vascular endothelial cells, which leads to microvascular dysfunction and promotes a procoagulant state. Dipyridamole (DP) acts as a reversible phosphodiesterase inhibitor and is used mainly as an antiplatelet agent. It is hypothetised that it has possible activities in COVID-19.

DESIGN AND METHODOLOGY

We report our retrospective, real-world results of DP added to low-molecular weight heparin (LMWH) in the treatment of 462 clinically diagnosed and hospitalized COVID-19 patients. We compared anticoagulation with and without DP addition with no administration of anticoagulation in the same time frame. The primary outcome was proven or highly suspected coagulopathy within 30 days of hospitalization.

RESULTS

Definitive coagulopathy has been diagnosed in 3 (3.5%) of 85 LMWH administered patients and 7 (2.13%) of 328 DP + LMWH received patients (P=0.456). Five cases with definitive coagulopathy were not initiated any anticoagulation at the time of the event. The multivariate analysis showed that DP addition to the anticoagulant approach did not have any impact on the risk of demonstrated coagulopathy and highly-suspected coagulopathy.

CONCLUSION

We think that our clinical experience is valuable in showing the real-life results of DP + LMWH treatment in COVID-19. This approach did not affect the coagulopathy rate. Our data did also not document an additive effect of DP in the COVID-19 outcome. Prospective controlled trials would give more convincing results regarding the role of DP in COVID-19 endothelial dysfunction and clinical outcome.

Enhanced Recovery After Surgery in the Patients With Hepatocellular Carcinoma Undergoing Hemihepatectomy

BACKGROUND

This study aims to compare the effectiveness and safety of enhanced recovery after surgery (ERAS) in patients with hepatocellular carcinoma (HCC) undergoing hemihepatectomy.

METHODS

From January 2017 to June 2019, 54 and 56 patients were enrolled into the control and ERAS group, retrospectively. All the indicators related to operation, liver functions, and postoperative outcomes were included in the analysis. Propensity score matching (PSM) analysis identified 72 patients for further analysis.

RESULTS

The clinicopathological characteristics were well-matched after PSM, and there were no significant differences in the operative duration, blood loss, blood transfusion, hospital costs, and most postoperative indicators in these 2 groups. In the ERAS group, D-dimer and fibrin degradation product values were significantly reduced (3.57 (2.874.60) μg/ml vs 4.81 (3.948.29) μg/ml and 11.90 (10.0418.02) μg/ml vs 15.80 (11.5529.24) μg/ml; P = .002 and P = .023, respectively). The days that semiliquid diet was allowed after surgery (2.00 (2.003.00) days vs 5.00 (4.006.00) days, P < .001), abdominal drainage tube indwelling duration (5.00 (4.005.00) days vs 5.00 (4.756.25) days, P = .004), and hospital stay after surgery (6.00 (6.007.00) days vs 8.00 (7.0010.00) days, P < .001) were also significantly shorter. The proportion of patients requiring analgesic treatment was significantly lower in the postoperative day 2 and day 4 (P < .001 and P = .025, respectively). The morbidity was significantly less (36.11% vs 69.44%, P = .005).

CONCLUSIONS

ERAS programs are feasible and safe in HCC patients undergoing hemihepatectomy. Postoperative anticoagulant therapy may be one of the necessary steps.