Risk Factors For Thromboembolism Research Articles

Risk of first venous thrombosis by comparing different thrombin generation assay conditions: results from the MEGA case-control study.

Background: Hypercoagulability is a risk factor for venous thromboembolism (VTE). Thrombin generation (TG) is a global coagulation assay that measures an individual’s clotting tendency. We hypothesise that slow onset TG (achieved by using a low procoagulant stimulus or an inhibitor of coagulation) is optimal responsive to detect hypercoagulability. Objectives: To compare different TG assay conditions with respect to VTE risk and to assess the risk of first VTE. Methods: Basal TG at low tissue factor (TF) concentration and high TF concentration in the presence and absence of activated protein C (APC) were measured in plasma samples from 2,081 patients with first VTE and 2,908 healthy controls from the MEGA study. TG parameters and nAPCsr were categorised into quartiles as measured in the controls. We calculated odds ratios (ORs) with 95% confidence intervals of a first VTE for different TG categories. Results: Under all assay conditions the thrombin peak height was associated with VTE risk: peak height > 75th percentile, at low TF odds ratio (OR) 6.8 (95% confidence interval (CI) 5.5 – 8.3), at high TF, odds ratio 3.0 (95% CI 2.5 – 3.6) and at high TF + APC, OR 3.8 (95% CI 3.2 - 4.5), all compared with a peak height < 25th percentile obtained in controls. An increased nAPCsr (higher resistance to APC) was also associated with VTE risk, odds ratio 3.4 (95% CI 2.8 – 4.1). Conclusions: increased TG is associated with the risk of first VTE, particularly when triggered with a low procoagulant stimulus.

Risk Factors for Venous Thromboembolism (VTE) Following Anterior Cruciate Ligament (ACL) Reconstruction: A Systematic Review and Meta-Analysis.

Thromboembolism (VTE) is an uncommon, but potentially serious complication in patients who undergo anterior cruciate ligament (ACL) reconstruction. PubMed, EMBASE, and Cochrane databases were searched for relevant studies published until July 16, 2023. Eligible studies were those investigating patients who were undergoing ACL reconstruction, with the primary focus on factors associated with VTE including age, sex, body mass index (BMI), hypertension, smoking, type of surgical setting (outpatient vs. inpatient), and tourniquet time. Six studies consisted of a total of 47,886 patients underwent ACL reconstruction were included. The VTE rate ranged between 0.4% and 11.0%, and the mean patient age ranged from 26.8 to 33.25 years. The meta-analysis revealed no significant association between VTE risk and sex (pooled adjusted odds ratio [aOR] = 1.28, 95% confidence interval [CI]: 0.88-1.85). Furthermore, the meta-analysis showed a significantly higher risk of VTE in smokers compared to non-smokers, favoring non-smokers (pooled aOR = 1.71, 95% CI: 1.16-2.54). The systematic review identified several other potential factors, including older age, BMI, hypertension, smoking, surgical setting, and tourniquet time, which were documented in at least 2 included studies. However, while some of these factors showed reported significance, the number of studies was insufficient to generate a pooled result. According to our meta-analysis, sex does not appear to be a significant risk factor for VTE in patients undergoing ACL reconstruction. However, more evidence is needed to determine whether factors such as older age, BMI, hypertension, outpatient vs. inpatient surgery, and tourniquet time are associated with increased VTE risk. Caution is still advised when managing patients with these risk factors in the context of ACL reconstruction. A future meta-analysis is warranted once a sufficient number of studies are available to draw more definitive conclusions. IV.

Glucagon-Like Peptide 1 Receptor Agonists and Venous Thromboembolism in Type 2 Diabetes: A Target Trial Emulation.

Glucagon-like peptide 1 receptor agonists (GLP1-RA) are anti-diabetes agents recently approved for weight loss. Obesity is an established risk factor for venous thromboembolism (VTE). Moreover, preclinical studies have shown that GLP1-RA may attenuate thromboxaneinduced platelet activation. Therefore, we hypothesized that GLP1-RA use may reduce the risk of VTE. We performed a target trial emulation using a population-based database of electronic health records to evaluate whether GLP1-RA use is associated with a reduction in VTE in patients with type 2 diabetes mellitus (T2DM) compared with dipeptidyl peptidas e-4 inhibitors (DPP4i). Patients who were newly initiated on GLP1-RA were propensity scorematched to patients who were newly initiated on DPP4i. We evaluated the primary outcome, composite VTE, identified using ICD-10 codes, within 12 months of the initiation of GLP1-RA or DPP4i. The study cohort comprised 540,258 patients with 270,129 individuals receiving either GLP1-RA or DPP4i. Over 12 months of follow-up, patients who received GLP1-RA had a lower incidence of VTE compared with patients who received DPP4i (6.1 vs. 7.6 events per 1000 patient-years, hazard ratio [HR], 0.78 [95% CI: 0.73-0.83]). This was similar for PE (2.9 vs. 3.8 events per 1000 patient-years, HR, 0.74 [95% CI: 0.68-0.82]) and DVT (3.9 vs. 4.7 events per 1000 patient-years, HR, 0.81 [95% CI: 0.75-0.88]). In this propensity scorematched, target trial emulation study, patients with T2DM who received a GLP1-RA had a lower risk of VTE at one year compared with patients who received DPP4i.

Risk factors for venous thromboembolism after hip arthroscopy: a systematic review and meta-analysis.

Postoperative venous thromboembolism (VTE) following hip arthroscopy is associated with increased hospital readmissions and significant medical costs. However, the risk factors for postoperative VTE after hip arthroscopy remain a topic of debate. In this study, we aimed to quantitatively and comprehensively identify risk factors for postoperative VTE after hip arthroscopy, providing evidence for the development of clinical prevention strategies. A systematic search was conducted using PubMed, Embase, Web of Science, Scopus, and the Cochrane Library databases from their inception to December 10, 2024. The search was limited to English-language articles that evaluated risk factors for postoperative VTE after hip arthroscopy. The quality of the included studies was assessed using the Newcastle-Ottawa Scale. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the relationship between various risk factors and the incidence of postoperative VTE after hip arthroscopy. This protocol was registered with PROSPERO (registration number: CRD42024601636). Five studies, encompassing 71,815 patients who underwent hip arthroscopy, were included in the meta-analysis. The analysis identified obesity (OR: 1.41, 95% CI: 1.23-1.61), smoking (OR: 1.23, 95% CI: 1.04-1.45), and age > 45 years (OR: 1.49, 95% CI: 1.03-2.15) as significant risk factors for postoperative VTE. Obesity, smoking, and age > 45 years are found to be significant risk factors for postoperative VTE after hip arthroscopy.

Clinical Characteristics and Risk Factors of Patients with Lung Cancer Complicated with Pulmonary Embolism: A Case Control Study.

The purpose of this study was to investigate the clinical characteristics and risk factors for patients with lung cancer complicated by pulmonary embolism and to provide a reference for the early clinical identification of these patients. Eighty patients with lung cancer complicated with pulmonary embolism who were treated at Bethune Hospital of Shanxi from October 2018 to October 2025 were compared with 80 patients with lung cancer without pulmonary embolism. The clinical data of the two groups of patients were collected and analysed. Compared with that in patients in the LC group, the proportion of patients with pulmonary interstitial fibrosis in the LP group was significantly greater (p < 0.05). The incidence of dyspnoea in the LP group was significantly greater than that in the LC group (p < 0.05). Compared with that in the LC group, the proportion of pulmonary artery compression in the LP group was significantly greater, and the difference was statistically significant (p < 0.05). In terms of pathological type, the proportion of adenocarcinoma patients in the LP group was significantly greater than that in the LC group (p < 0.05). In terms of tumor stage, the proportion of patients with stage III/IV disease in the LP group was significantly greater than that in the LC group, while the proportion of patients with stage I/II disease was significantly lower than that in the LC group, and the difference was statistically significant (p < 0.05). The neutrophil [NEUT (%)], prothrombin time (PT), white blood cell (WBC), carcinoma embryonic antigen (CEA) and D-dimer (DD) levels were significantly greater in the LP group than in the LC group (p < 0.05). In terms of treatment, the proportion of patients receiving systemic chemotherapy in the LP group was significantly greater than that in the LC group (p < 0.05). Logistic regression analysis revealed that adenocarcinoma, systemic chemotherapy and tumor stage III-IV were independent risk factors for lung cancer complicated with pulmonary embolism. (1) Tumor stage (III/IV), systemic chemotherapy, and adenocarcinoma were independent risk factors for pulmonary thromboembolism in patients with lung cancer. (2) In addition, patients with LP were more likely to have pulmonary interstitial fibrosis, dyspnoea, compression of the pulmonary artery by the tumor location, biological targeted therapy, and abnormal increases in D-dimer, WBC, NEUT (%), CEA and PT levels as laboratory indicators. (3) Pulmonary thromboembolism should be considered in lung cancer patients with a combination of the factors described above.

Risk factors for venous thromboembolism in patients undergoing neoadjuvant chemotherapy as treatment for ovarian cancer.

During the treatment of ovarian cancer, the risk of venous thromboembolism (VTE) post operatively is well established, however, patients may be at even greater risk during neoadjuvant chemotherapy (NACT). This study aimed to determine the incidence and timing of VTE amongst patients undergoing NACT, whether there was an association with survival, and examine risk factors associated with the development of VTE. This was a retrospective cohort study of patients diagnosed with ovarian, fallopian tube and primary peritoneal cancer receiving neoadjuvant chemotherapy betweenApril 2011 and April 2022 at a gynaecological cancer centre in England. Clinical factors examined included: age at diagnosis, Body Mass Index (BMI), presence of inflammatory co-morbidity, tumour morphology, stage of disease, pelvic mass,ascites,retroperitoneal lymphadenopathy, Khorana score, serum albumin levels, chemotherapy regime, bevacizumab administration and Ca 125 levels. Of 304 patients analysed, 73 (24%) patients developed venous thromboembolism. Of the patients who developed VTE, fifty-five patients developed pulmonary embolism (75%) and the stage of treatment at which most VTEs were diagnosed was neoadjuvant chemotherapy (32%). There was no correlation observed, between the incidence of VTE and any risk factors, including Khorana score, with the exception of low albumin (<35g/L)(odds ratio (OR):2.1(95%CI 1.1-3.9; p=0.06) and patients who did not receive paclitaxel chemotherapy (OR:2.04(95%CI 1.02-4.05; p=0.08). There was no difference in survival rates between the VTE group and the non-VTE group. This study demonstrates high rates of VTE, especially pulmonary embolism, in ovarian cancer patients undergoing NACT. The present study, amongst others in the literature also suggest that the risk of VTE in ovarian cancer patients undergoing NACT is underestimated by current risk stratification models. Therefore, prospective trials dedicated to ovarian cancer patients specifically, and a development of a risk model that takes into account factors established by higher levels of evidence, are strongly recommended.

Incidence and risk of arterial thromboembolism in cancer patients from a safety-net healthcare system.

The incidence of and risk factors for arterial thromboembolism (ATE) in patients with cancer, particularly in those with low socioeconomic status, remains understudied. We aim to report the association between cancer-related and cardiovascular (CV) risk factors and the development of ATE. We performed a retrospective cohort study for patients with newly diagnosed invasive cancer from 2011 to 2021 at a safety-net hospital system. We ascertained ATE outcomes using validated inpatient billing diagnosis codes for myocardial infarction (MI) and ischemic stroke (iCVD). We examined the incidence of ATE after cancer diagnosis using the cumulative incidence competing risk method to account for early mortality and estimated sub-distribution hazard ratios for ATE using multivariable Fine-Gray models. Among 17,236 patients (45.4% male, median 56 years), the ATE incidence was 1.5% (1.3%-1.6%) at 1-year and 2.8% (2.5%-3.0%) at 5-year after cancer diagnosis. In unadjusted analysis, the 5-year ATE incidence was highest in hematologic malignancies such as multiple myeloma (8.6%) and acute leukemia (7.8%), among patients receiving immune checkpoint inhibitors (8.3% vs 2.7%), those with poor Eastern Cooperative Oncology Group performance status (PS) (5.4% PS 4 vs 2.2% PS 0), and advanced stage (3.1% IV vs 1.9% I). After multivariable adjustment, only cancer type remained significantly associated with ATE along with known CV risk factors including advanced age, smoking, diabetes, hypertension, history of MI, and history of iCVD. Both cancer type and traditional CV risk factors are independently associated with the development of ATE in patients with cancer.

Pharmacological prophylaxis of venous thromboembolism in surgical patients

Venous thromboembolism is the third most common cardiovascular disease after myocardial infarction and stroke, affecting a significant percentage of the population. Surgery is a well-known risk factor for venous thromboembolism, and the more serious the surgical procedure, the higher the risk of developing it. This review provides an analysis of the main risk factors for venous thromboembolism in operated patients, the role of optimizing the balance of thromboembolism/bleeding risk in determining the individual risks of surgical patients, and a comparative analysis of therapy for venous thromboembolism using drugs with antiplatelet and anticoagulant activity. A summary of the data available in the scientific literature shows that, despite the existing variety of antiplatelet and anticoagulant drugs, the second-generation low-molecular-weight heparins, with bemiparin as A prominent representative, are currently the first-line drugs for the pharmacoprophylaxis of venous thromboembolism in the context of major surgical interventions, which has been confirmed by numerous clinical trials conducted around the world. Special clinical studies have confirmed the equivalence of efficacy and safety, and in some cases, also certain advantages of second-generation drugs (for example, bemiparin) in comparison with enoxaparin, the most common first-generation drug currently used in clinical practice in surgical/oncological patients. The duration of bleeding prophylaxis with bemiparin and other low-molecular-weight heparins in surgical/oncological patients, according to the data of most clinical trials with an appropriate level of evidence, may range from 1–2 weeks up to 35 days, depending on the individually assessed balance of thromboembolism/bleeding risks.

P1103 Thromboembolic and cardiovascular risk profiles in ulcerative colitis patients initiating advanced therapies: a single-center study

Abstract Background IBD, especially during flare periods, seems to be associated with an increased risk of thromboembolic and cardiovascular(CV) events[1]. After the results of the ORAL Surveillance study[2] enrolling patients with rheumatoid arthritis, several concerns have also been raised on the intrinsic risk of Janus kinase inhibitors (JAK-i), though the population enrolled was predominantly &amp;gt;50 years old and had several CV risk factors (CVRF). Accordingly, regulatory agencies recommend that JAK-i should be used only if no suitable treatment alternatives are available in patients at increased CV risk for all indications [3]. However, the real prevalence of CVRF and the risk related to JAK-i seem to be lower for patients with UC. The aim of our study is to explore the prevalence of thromboembolic and CV risks factors in a large cohort of UC patients suitable for advanced therapies. Methods We conducted a single-centre study including all consecutive adult patients with UC who initiated advanced therapies between Jun-20 and Dec-23. To assess thrombosis and CV risk, we collected all anamnestic, clinical and laboratory data from the medical records. In addition, we used an online questionnaire to collect all other information that were not available in routine clinical records. To assess CV risk, we calculated the 10-year CV risk score using the American College of Cardiology ASCVD Risk Estimator[4]. Results Out of 305 patients surveyed, we had a 100% response rate: 53.5% male, with a median age of 44 years. Overall, 39.0% were biologic-naïve, and 21.6% started a Janus kinase inhibitor (JAK-i). Baseline patients’ characteristics and variables collected are shown in Table 1 and Table 2, respectively. Cumulatively, 184 patients (60.3%) had 0-1 thromboembolic risk factors, 73 patients (23.93%) had 2 risk factors, 34 patients (11.2%) had 3 risk factors, 8 patients(2.6%) had 4, and 6 patients(1.9%) had 5 or 6 thromboembolic risk factors. Complete cholesterol data were available for 171 patients, but ASCVD score has been calculated only for 153 patients(median age 49 years) with LDL-C levels &amp;gt;70 mg/dL. Among them, 67.3% were classified as low risk, 6.5% as borderline risk, 20.9% as intermediate risk, and 5.2% as high risk. When CV risk was stratified by age, 66.7% of elderly patients (aged 65 years or older) were classified as intermediate risk, while 20.8% were high risk. In contrast, 79.1% of non-elderly were categorized as low risk, 12.4% at intermediate risk and 2.3% at high risk. Conclusion Our study confirms the prevalence of thrombotic and CVRF among patients affected by UC is quite low and mostly related to age. Accordingly, the concerns regarding the use of JAK-i observed in rheumatological cohorts may not be fully applicable for patients with UC.

Liver Injury as a Risk Factor for Post-Traumatic Venous Thromboembolism.

Venous thromboembolism (VTE) remains a major source of morbidity and mortality in severely injured patients despite current methods of risk stratification and prophylaxis, suggesting incomplete understanding of VTE risk factors. Given the liver's role in coagulation, we hypothesized that liver injury (LI) is associated with increased rates of VTE in severely injured patients. The American College of Surgeons Trauma Quality Improvement Project database (TQIP) 2017-2021 was retrospectively reviewed for patients with a maximum abdominal Abbreviated Injury Score (AIS) ≥ 4 with or without LI. Transfers, burns, all deaths, and patients < 18 years of age were excluded. Logistic regression was performed to assess the independent effect of LI on development of pulmonary embolism (PE) and deep venous thrombosis (DVT) while controlling for potential confounding variables. In 44,506 patients, there were 1,736 (3.9%) 890 (2.0%), and 18,642 patients (41.9%) with DVT, PE, and LI, respectively. After controlling for potential confounders, LI was independently associated with PE (aOR 1.279 [95% CI 1.088-1.504]) but was not associated with DVT (aOR 1.011 [95% CI 0.897-1.140]). In severely injured patients, LI is an independent predictor of PE, but not DVT, suggesting LI is the source of either emboli or a more complex locally prothrombotic focus leading to downstream thrombi in the lung without causing upstream systemic venous thrombi. Further work should focus on elucidation of mechanisms including the portal venous blood coagulation profile, endothelial injury in the liver, and the potential for stasis of venous blood traversing an injured liver as well as the role for including LI in VTE risk stratification.

P1155 Safety of Venous Thromboembolism Pharmacological Prophylaxis in Hospitalized Patients with Inflammatory Bowel Disease; A Single Center Retrospective Study (VISCOUS)

Abstract Background Hospitalization secondary to inflammatory bowel disease flare is a significant risk factor for venous thromboembolism (VTE). International guidelines recommend the use of pharmacological VTE prophylaxis; however, the risk of bleeding is unknown. We therefore aimed to evaluate the safety of pharmacological thromboprophylaxis in hospitalized patients with IBD. Methods This was a retrospective cohort study. A chart review of patients’ electronic health records with IBD hospitalized between August 2017 to December 2023 was reviewed. Our primary outcome is evaluating the safety of pharmacological VTE prophylaxis. This was investigated by examining increased bleeding risks during admission, which included worsening bloody stool frequency, drop in hemoglobin (&amp;gt;1g/dL from baseline) and development of hemorrhagic shock after starting VTE prophylaxis. Worsening bloody stool frequency was defined as increased bloody stool frequency &amp;gt;1 from baseline before starting VTE prophylaxis. Finally, any major bleeding was also considered. Results Between August 2017 and December 2023, 1045 patient encounters were reviewed. 524 patients met the study inclusion and exclusion criteria, of which 98 had missing information and 73 were duplicates and could not be included. Finally, 353 patients were included in our study. Mean age 34.7 years, 205 (58%) were female males and mean duration of hospitalization was 9 days. Majority of patients were hospitalized with acute severe ulcerative colitis (ASUC) 213 (60.3%), and 140 (39.7%) had Crohn’s disease (CD) flare. Of the total cohort, 264 (75%) patients received enoxaparin 40 mg for VTE prophylaxis, and the 89 (25%) patients received 5000 units of unfractionated heparin twice a day (figure 1). Eighteen (%5) patients had a history of VTE, and 4 female patients had VTE during admission. None of our cohort had any bleeding events including worsening bloody stool frequency, drop in hemoglobin, major bleeding and development of hemorrhagic shock after starting VTE prophylaxis up to the period patients were discharged. Conclusion we found no increased risk of gastrointestinal bleeding in patients admitted with IBD on pharmacological VTE prophylaxis. Therefore, it is important to reassure healthcare providers about the safety of pharmacological VTE prophylaxis in IBD and adopt strategies that guarantee prophylaxis is administered during hospitalization. Although that a balance should be established between the benefits and risks. References -Pleet JL, Vaughn BP, Morris JA, et al. The use of pharmacological prophylaxis against venous thromboembolism in hospitalised patients with severe active ulcerative colitis. Aliment Pharmacol Ther [Internet]. 2014;39(9):940–948. -Dawwas GK, Cuker A, Schaubel DE, et al. Effectiveness and safety of prophylactic anticoagulation among hospitalized patients with inflammatory bowel disease. Blood Adv [Internet]. 2024;8(5):1272–1280. -Kaddourah O, Numan L, Jeepalyam S, et al. Venous thromboembolism prophylaxis in inflammatory bowel disease flare-ups. Ann Gastroenterol. 2019;32(6):578–583.

Factors associated with venous thromboembolism in tuberculosis patients in Burkina Faso: A case control study

The mortality caused by tuberculosis is partially explained by co-morbidities such as venous thromboembolic disease. Our study was aimed at identifying the factors associated with venous thromboembolism in tuberculosis patients. This was a case-control study of patients with pulmonary tuberculosis with or without venous thromboembolic disease. The study was conducted in the pneumology department of Yalgado Ouédraogo University Hospital from 1st January 2021 to 31st March 2024. All in all, 80 patients were included in the study. In univariate analysis, the factors significantly associated with venous thromboembolic disease were: prolonged bed rest (P=0.000), hyperleukocytosis (P=0.044), hemoglobin level less than 10g/dL (P=0.024), C-reactive protein level greater than or equal to 150mg/L (P=0.036), bronchial dilatation lesions (P=0.041), and extensive lung lesions (P=0.016). After adjustment, prolonged bed rest (OR=7.68; [1.52-38.74]), hemoptysis (OR=24.65; [1.84-328.77]), leukocytosis (OR=2.13; [1.33-26.51]), were significantly associated with venous thromboembolism. Venous thromboembolism remains a dreaded complication that should be investigated in any tuberculosis patient with thromboembolic risk factors.

Brisk Walking Pace Offsets Venous Thromboembolism Risk Equivalent to Established Monogenic Mutations.

Mendelian mutations in the Prothrombin gene (F2) and the factor V Leiden gene (F5) genes are established risk factors for venous thromboembolism (VTE). Walking pace is associated with the risk of coronary artery diseases, but no study has investigated its association with VTE. This study aimed to investigate the association and causality between walking pace and VTE, compare its population risk with established Mendelian mutations, and determine if blood biomarkers mediate its effect. We followed up 445,261 UK Biobank participants free of VTE at baseline. Self-reported walking pace was collected via touchscreen questionnaire at baseline. The carrier status of two Mendelian mutations in F2 and F5 genes was determined by the genotypes of rs1799963 (G20210A, c.*97 G > A) and rs6025 (p.R534Q), respectively. Cox proportional hazard model was used to estimate the effect of walking pace on incident VTE. We conducted a bidirectional Mendelian randomization (MR) analysis, by using 70 single-nucleotide polymorphisms (SNPs) from a walking pace genome-wide association studies (GWAS) and 93 SNPs from a VTE GWAS as instrumental variables. We used both individual-level data and GWAS summary statistics for mediation analysis. Over a median follow-up period of 12.8 years, 11,155 incident VTE cases were identified. The 10-year incidence rates for brisk and slow walking pace were 1.32% (confidence interval [CI]: 1.27-1.37%) and 3.90% (CI: 3.71-4.09%), respectively. For noncarriers, F2 and F5 carriers, the 10-year incidence rates were 1.70% (CI: 1.66-1.73%), 2.94% (CI: 2.66-3.22%), and 3.62% (CI: 3.39-3.84%), respectively. The overall risk of VTE for F5 mutation carriers with a brisk walking pace (2.65%) was smaller than that for noncarriers with a slow walking pace (3.66%). For F5 mutation carriers, brisk pace (but not steady pace) reduces the risk of VTE (p interaction < 0.05). MR analyses displayed a causal relationship (inverse variance weighted: p = 3.21 × 10-5) from walking pace to VTE incidence. Mediation analysis showed that serum albumin (ALB) and cystatin C (CYS) levels partially mediated the effect of brisk walking pace on the risk of VTE incidence, with mediation proportions of 8.7 to 11.7%, respectively. On the population scale, the protective effect of brisk walking pace offsets the risk of VTE caused by Mendelian mutations. We provided preliminary evidence that a brisk walking pace causally reduces the risk of VTE. Serum ALB and CYS partially mediate this effect.

Effect of prophylactic doses of enoxaparin on antifactor Xa activity confirmed by rotational thromboelastometry in critically ill patients: a preliminary prospective cohort study.

Critically ill patients present multiple risk factors for venous thromboembolism (VTE). Underdosing of antithrombotic medications can result in VTE even as bleeding remains a significant concern for critically ill patients. On the other hand bleeding, remaining a significant concern for the critically ill, can be worsend by overdosing of antithrombotic medications. The present study aimed to assess the effects of prophylactic doses of enoxaparin on antifactor Xa activity (anti-Xa) and rotational thromboelastometry (ROTEM) parameters in critically ill patients. In this prospective single-center cohort study, the effects of enoxaparin were assessed via anti-Xa monitoring. Standard laboratory coagulation and ROTEM parameters were also determined using the same blood samples. A total of 61 patients (42.6% women) were enrolled in this study, whose median age was 59.0 (interquartile range: 43.0-70.0) years. Based on anti-Xa, the effects of enoxaparin were normal in 35 subjects (57.4%); in 17 patients (27.9%), the anti-Xa troughs and/or peaks were higher than the prophylactic range; in 9 patients (14.7%), the anti-Xa peak was lower than the prophylactic range. There were differences among the anti-Xa groups with respect to some ROTEM parameters. No VTE was detected among the study subjects. In 3 subjects (4.9%), there were signs of bleeding, and these patients presented with longer thrombin times. Anti-Xa values may be within the prophylactic range in slightly more than half of the critically ill patients receiving enoxaparin at prophylactic doses. The dosing of low-molecular-weight heparin (LMWH) in critically ill patients may require individualization based on anti-Xa. Further studies are therefore required to establish a universal anti-Xa prophylactic range for LMWH, the timing of anti-Xa determination, and management of LMWH dosing.

Low-dose aspirin versus placebo in postpartum venous thromboembolism: a multi-national, pilot, randomised, placebo-controlled trial.

Despite the morbidity and mortality of venous thromboembolism, there is little evidence to guide postpartum thromboprophylaxis in patients at moderate risk. We aimed to assess the feasibility of conducting a double-blind, randomised trial of aspirin versus placebo in postpartum individuals with two or more venous thromboembolism risk factors, mild-to-moderate thrombophilia, or both. The pilot PARTUM trial, a multi-national, randomised, double-blind, placebo-controlled trial, was conducted in seven centres across Canada, France, Ireland, and the Netherlands. Postpartum individuals aged 18 years or older with venous thromboembolism risk factors, including mild-moderate inherited thrombophilia, antepartum immobilisation, pre-pregnancy BMI of 30 kg/m2 or higher, pre-pregnancy smoking, previous superficial vein thrombosis, and other pregnancy-related conditions, were eligible. Participants were randomly assigned (1:1) within 48 h of delivery to aspirin 81 mg (80 mg in Europe) orally daily (low-dose aspirin group) or placebo orally once daily (placebo group) for 42 days. Follow-up visits occurred at 6 weeks and 90 days postpartum. The primary outcome was the mean recruitment rate (participants per site per month). Additional feasibility metrics were reported, and clinical outcomes were analysed by intention to treat. This study is registered with ClinicalTrials.gov, NCT04153760, and EudraCT, 2020-000619-58, and is completed. Between Nov 2, 2020, and June 19, 2023, 10 040 patients were assessed for eligibility and 808 met all eligibility criteria, of whom 257 (32%) provided consent and were enrolled. 127 were randomly assigned to the low-dose aspirin group and 130 to the placebo group. The median follow-up was 91 days (IQR 89-96). The median age was 34·0 years (IQR 30·0-37·0), and 161 (63%) of participants were White. The mean recruitment rate was 6·3 (95% CI 5·5 to 7·2) patients per site per month. No venous thromboembolism events occurred in the low-dose aspirin group, and one participant had distal deep vein thrombosis in the placebo group (-0·82 [95% CI -2·42 to 0·78]). No major bleeds occurred. Three (2%) participants in the low-dose aspirin group versus one (1%) in the placebo group had clinically relevant non-major bleeds (absolute risk difference 1·66 [95% CI -1·54 to 4·86]). Ten serious adverse events occurred in nine (4%) of 257 participants, and 11 serious adverse events occurred in ten (4%) of 271 infants of participants. No treatment-related death occurred. A global postpartum thromboprophylaxis trial evaluating low-dose aspirin is possible and needed to provide high-quality data. Canadian Institutes of Health Research and the INVENT-VTE Network.

Application of low-intensity anticoagulation after On-X mechanical aortic valve replacement

ObjectiveTo explore the safety and efficacy of low-intensity anticoagulation in patients after On-X mechanical aortic valve replacement.MethodsA total of 104 patients undergoing aortic valve replacement in Cardiac Surgery Department of Sichuan Provincial People’s Hospital from December 2018 to December 2021 were randomly divided into low-intensity anticoagulant (INR:1.5-2.0) and high-intensity anticoagulant (INR:2.0-2.5) to compare the incidence of adverse events related to postoperative anticoagulation between the two groups.ResultsFifty-three patients were included in the low-intensity anticoagulation group (INR 1.5-2.0), and 51 patients were included in the high-intensity group (2.0-2.5). There was no significant difference in baseline data and surgical index between the two groups (P > 0.05); there were statistically significant differences in PT, INR and bleeding events (P < 0.05), but no significant difference in embolic events (P > 0.05).ConclusionFor patients requiring On-X mechanical aortic valve replacement who have no risk factors for thromboembolism, it is appropriate to control the INR in the target range 1.5-2.0, which can reduce the incidence of bleeding adverse events and significantly improve the quality of life, without increasing the risk of thromboembolic adverse events.

Clinical Outcomes and Healthcare Utilization in Pulmonary Embolism Patients With and Without Prothrombin G20210A Mutation: A National Retrospective Cohort Study.

Pulmonary embolism (PE) is a severe condition often linked to thromboembolic risk factors, such as the prothrombin gene (PGM) G20210A mutation. Although this mutation is a recognized risk factor for venous thromboembolism, little is known about how it affects the clinical course and healthcare utilization of PE patients. This new study will reveal the complete effect of PGM on clinical outcomes in patients treated for PE, such as hospital stay length, in-hospital death rates, healthcare costs, and associated health conditions. It will also examine how socioeconomic status and demographics impact these outcomes. This retrospective cohort study was conducted using data from the National Inpatient Sample (NIS) from 2016 to 2020. It included adults admitted with a primary diagnosis of PE aged 18 and older. The patients were divided into two groups: those with the PGM mutation and those without. There were two groups where the patients was divided based on their PGM use: those with and those without. Multivariate logistic regression assessed in-hospital mortality, while linear regression models evaluated length of stay (LOS) and healthcare charges. The models were adjusted for demographics, comorbidities (Charlson Comorbidity Index), and hospital characteristics. Among the 903,230 PE patients, 2,065 (0.2%) had PGM. Patients with the mutation had a significantly lower in-hospital mortality than those without the mutation (adjusted OR 0.13, 95% CI 0.02-0.92, p = 0.041). PGM carriers also had lower rates of atrial fibrillation (5.1% vs. 11.8%, p < 0.001), congestive heart failure (CHF) (5.9% vs. 16.0%, p < 0.001), and chronic obstructive pulmonary disease (COPD) (8.6% vs. 15.5%, p < 0.001), but higher rates of obesity (32.5% vs. 26.1%, p = 0.004) and hyperlipidemia (30.7% vs. 36.0%, p = 0.031). Despite a longer hospital stay in PGM patients (mean difference: 0.52 days, p = 0.005), the difference in total hospital charges was not statistically significant (mean difference: $6,295, p = 0.090). Patients with PE and the PGM had lower mortality rates in this national retrospective cohort than those without the mutation. Patients without the PGM presented with more serious comorbidities, including higher rates of atrial fibrillation, CHF, and COPD, which may have contributed to their worse outcomes.

Risk of venous thromboembolic complications in pregnant trauma patients: A matched cohort study.

Trauma and pregnancy are both risk factors for venous thromboembolism (VTE). We hypothesized that pregnant blunt trauma patients would have a higher incidence of VTE complications compared with matched nonpregnant females. We conducted a retrospective cohort study using National Trauma Data Bank data from 2017 to 2022. Female patients with blunt mechanism, age between 15 and 50years old, were eligible for inclusion. Patients who presented as transfers, hospitalized for less than 72h, discharged against medical advice, injury severity score <9, or abbreviated injury scale=6 of any region were excluded. Pregnant patients were matched 1:2 with nonpregnant female patients by age, injury characteristics, comorbidities, and type and timing of chemical VTE prophylaxis. The primary outcomes were the incidences of VTE, deep vein thrombosis (DVT), and pulmonary embolism (PE). Secondary outcomes included other complications and length of stay. We included 735 pregnant and 1470 matched nonpregnant controls. The median time to initiate chemical VTE prophylaxis was 33h in pregnant and 34h in nonpregnant patients (p=0.42). The incidence of VTE in pregnant blunt trauma patients was 27 (3.7%) versus 45 (3.1%) in matched controls (p=0.446). There were no significant differences in DVT, PE, or any other complication or mortality or in ICU or hospital length of stay. Unplanned admissions to the ICU were significantly more frequent in pregnant patients (3.8% vs. 2.2% and p=0.026). The incidence of VTE complications was similar in pregnant and matched nonpregnant female blunt trauma patients in this retrospective cohort study, supporting the safety of current VTE prophylaxis practices in pregnant patients.

High Altitude is an Independent Risk Factor for Postoperative Venous Thromboembolism Following Primary Total Knee Arthroplasty: A Large Database Study.

High altitude may induce physiological changes that can predispose patients to venous thromboembolism (VTE), a relatively uncommon, but potentially fatal complication following total knee arthroplasty (TKA). The purpose of this study was to determine if high altitude is an independent risk factor for postoperative VTE following TKA. A large claims database was queried for patients who underwent TKA at high-altitude (≥ 1,219-meters) and low-altitude (≤ 30-meters) using Current Procedural Terminology codes, International Classification of Disease codes, and zip codes. High- and low-altitude cohorts were matched 1:3 by 5-year age range, sex, Charlson comorbidity index (CCI), diabetes mellitus, obesity (body mass index ≥ 30), hypertension, and tobacco use. There were 57,135 patients included in the high-altitude group and 171,322 in the low-altitude group. Outcome measures included 30- and 90-day incidence of VTE, deep venous thrombosis (DVT), and pulmonary embolism (PE). Chi-square was used to determine differences in demographics. Binomial logistic regression was used to determine postoperative rates of VTE, DVT, and PE. The incidence of VTE was significantly greater in the high-altitude versus the low-altitude group at 30-days (OR [odds ratio] 1.15 [95% CI (confidence interval) 1.02 to 1.30], P = 0.022) and 90-days (OR 1.20 [95% CI 1.08 to 1.34], P = 0.0007). The incidence of DVT was significantly higher for the high-altitude cohort at both 30- (OR 1.30 [95% CI 1.10 to 1.54], P = 0.002) and 90-days (OR 1.36 [95% CI 1.18 to 1.57], P < 0.0001). The incidence of PE within 30- and 90-days was not significantly different between groups. High altitude (> 1,219-meters) is an independent risk factor for VTE following TKA. Patients who undergo TKA at surgical centers greater than 1,219-meters in elevation are more likely to develop VTE and DVT within 30- and 90-days postoperatively. Surgeons may account for high altitude as a risk factor and determine the most suitable postoperative prophylaxis method for their patients.

Genetic correlation between genes targeted by lipid-lowering drugs and venous thromboembolism: A drug-target Mendelian randomization study.

Dyslipidemia has been established as a potential risk factor for venous thromboembolism (VTE) in several observational studies. Statins and novel lipid-modifying agents are being explored for their potential in VTE prevention, encompassing deep vein thrombosis (DVT), and pulmonary embolism (PE). Nonetheless, conclusive evidence supporting the effectiveness remains uncertain. Without definitive proof, the current recommendation of lipid-lowering drugs (LLDs) for preventing VTE, either primarily or secondarily, is not support. An investigation into the impact of 8 classes of LLDs on VTE was conducted using a drug-target Mendelian randomization approach. The drug categories examined included 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), apolipoprotein B, proprotein convertase subtilisin/kexin type 9, Niemann-Pick C1-like 1, lipoprotein lipase (LPL), angiopoietin-like 3, apolipoprotein C3 (APOC3), and peroxisome proliferator-activated receptor alpha. Leveraging genetic variants situated proximate to or within drug-target genes linked with low-density lipoprotein and triglycerides, we acted as proxies for LLDs. The UK Biobank study was the source of data on VTE, PE, and DVT of lower extremities (LEDVT). We employed the inverse-variance weighted method for the core analysis in Mendelian randomization, complemented by sensitivity analysis to investigate horizontal pleiotropy and heterogeneity. Employing genetic proxies to inhibit HMGCR revealed a notable correlation with reduced LEDVT risk (odds ratio [OR]: 0.995, 95% CI: 0.992-0.998, P = .002), VTE (OR: 0.994, 95% CI: 0.988-1.000, P = .033), but a no significant association with PE (OR: 1.000, 95% CI: 0.994-1.002, P = .246). The suppression of APOB was linked with an elevated risk of experiencing LEDVT (OR: 1.002, 95% CI: 1.001-1.004, P = .006), VTE (OR: 1.005, 95% CI: 1.002-1.007, P < .001), and PE (OR: 1.002, 95% CI: 1.000-1.004, P = .031). Similarly, the activation of LPL was associated with increased risks for VTE (OR: 1.003, 95% CI: 1.001-1.005, P = .003) and PE (OR: 1.003, 95% CI: 1.002-1.005, P < .001). Additionally, the inhibition of APOC3 was linked to a higher DVT risk (OR: 1.002, 95% CI: 1.000-1.004, P = .038). Research has shown that HMGCR, out of 8 lipid-lowering drug-targets evaluated, exhibited a significant correlation with VTE and LEDVT, highlighting its potential as an effective target for the treatment or prevention of these conditions. In contrast, APOB, LPL, and APOC3 each contribute to an increased risk of VTE, PE, and LEDVT in various degrees, pharmacovigilance for VTE, PE, and LEDVT risk among users of APOB inhibitors, LPL activation, and APOC3 inhibitors may be warranted.