Development Of Venous Thromboembolism Research Articles

Exploring the Two-Way Link between Migraines and Venous Thromboembolism: A Bidirectional Two-Sample Mendelian Randomization Study.

The objective of this study is to utilize Mendelian randomization to scrutinize the mutual causality between migraine and venous thromboembolism (VTE) thereby addressing the heterogeneity and inconsistency that were observed in prior observational studies concerning the potential interrelation of the two conditions. Employing a bidirectional Mendelian randomization approach, the study explored the link between migraine and VTE, incorporating participants of European descent from a large-scale meta-analysis. An inverse-variance weighted (IVW) regression model, with random-effects, leveraging single nucleotide polymorphisms (SNPs) as instrumental variables was utilized to endorse the mutual causality between migraine and VTE. SNP heterogeneity was evaluated using Cochran's Q-test and to account for multiple testing, correction was implemented using the intercept of the MR-Egger method, and a leave-one-out analysis. The IVW model unveiled a statistically considerable causal link between migraine and the development of VTE (odds ratio [OR] = 96.155, 95% confidence interval [CI]: 4.342-2129.458, p = 0.004), implying that migraine poses a strong risk factor for VTE development. Conversely, both IVW and simple model outcomes indicated that VTE poses as a weaker risk factor for migraine (IVW OR = 1.002, 95% CI: 1.000-1.004, p = 0.016). The MR-Egger regression analysis denoted absence of evidence for genetic pleiotropy among the SNPs while the durability of our Mendelian randomization results was vouched by the leave-one-out sensitivity analysis. The findings of this Mendelian randomization assessment provide substantiation for a reciprocal causative association between migraine and VTE within the European population.

The role of green tea intake in thromboprophylaxis of venous thromboembolism in patients with cancer.

Green tea intake has been reported to improve the clinical outcomes of patients with cardiovascular diseases or cancer. It may have a certain role in the development of venous thromboembolism (VTE) among cancer patients. The current study aimed to address this issue, which has been understudied. We carried out a retrospective study to explore the role of green tea intake in cancer patients. Patients with and without green tea intake were enrolled in a 1:1 ratio by using propensity scoring matching. The primary and secondary outcomes were VTE development and mortality 1 year after cancer diagnosis, respectively. The cancer patients with green tea intake (n = 425) had less VTE development (10 [2.4%] vs. 23 [5.4%], p = 0.021), VTE-related death (7 [1.6%] vs. 18 [4.2%], p = 0.026), and fatal pulmonary embolism (PE) (3 [0.7%] vs. 12 [2.8%], p = 0.019), compared with those without green tea intake (n = 425). No intake of green tea was correlated with an increase in VTE development (multivariate hazard ratio (HR) 1.758 [1.476-2.040], p < 0.001) and VTE-related mortality (HR 1.618 [1.242-1.994], p = 0.001), compared with green tea intake. Patients with green tea intake less than 525 mL per day had increased VTE development (area under the curve (AUC) 0.888 [0.829-0.947], p < 0.001; HR1.737 [1.286-2.188], p = 0.001) and VTE-related mortality (AUC 0.887 [0.819-0.954], p < 0.001; HR 1.561 [1.232-1.890], p = 0.016) than those with green tea intake more than 525 mL per day. Green tea intake caused a decrease in platelet (p < 0.001) instead of D-dimer (p = 0.297). The all-cause mortality rates were similar between green tea (39 [9.2%]) and non-green tea (48 [11.3%]) intake groups (p = 0.308), whereas the VTE-related mortality rate in the green tea intake group (7 [1.6%]) was lower than that of the non-green tea intake group (18 [4.2%]) (p = 0.026). The incidences of adverse events were similar between the green tea and non-green tea intake groups. In conclusion, the current study suggests that green tea intake reduces VTE development and VTE-related mortality in cancer patients, most likely through antiplatelet mechanisms. Drinking green tea provides the efficacy of thromboprophylaxis for cancer patients.

Association between migraine and venous thromboembolism: a Mendelian randomization and genetic correlation study.

Previous observational studies have reported an increased risk of venous thromboembolism (VTE) among individuals with migraine. This study aimed to investigate the causal effect of migraine on the development of VTE, as well as explore the genetic correlation between them. We conducted a two-sample Mendelian randomization (MR) study using publicly available summary statistics from large-scale genome-wide association studies for migraine and VTE. Linkage disequilibrium score regression analysis was performed to estimate the genetic correlation between migraine and VTE. There were several shared risk variants (p-value < 5 × 10-8) between migraine and VTE. Linkage disequilibrium score regression analysis found a significant positive genetic correlation between migraine and VTE. The genetic correlations based on two migraine datasets were 0.208 (se = 0.031, p-value = 2.91 × 10-11) and 0.264 (se = 0.040, p-value = 4.82 × 10-11), respectively. Although main MR analysis showed that migraine was associated with an increased risk of VTE (odds ratio = 1.069, 95% confidence interval = 1.022-1.118, p-value = 0.004), the association attenuated to non-significance when using several other MR methods and using another set of genetic instruments. In addition, evidence of heterogeneity was found. Reverse MR analysis showed VTE was associated with increased risk of migraine with aura (odds ratio = 1.137, 95% confidence interval = 1.062-1.218, p-value = 2.47 × 10-4) with no evidence of pleiotropy and heterogeneity. We showed suggestive evidence indicating an association between migraine and increased risk of VTE. Additionally, we found robust evidence suggesting that VTE is associated with an increased risk of migraine. The positive genetic correlation indicates that migraine and VTE has shared genetic basis. Further investigations will be necessary to address potential sex-specific effects in the analysis.

466 Development of Machine Learning Algorithms to Predict Symptomatic VTE at Time of Admission and Time of Discharge after Severe Traumatic Injury

OBJECTIVES/GOALS: Clinical indicators predictive of venous thromboembolism (VTE) in trauma patients at multiple time points are not well outlined, particularly at time of discharge. We aimed to describe and predict inpatient and post-discharge risk factors of VTE after trauma using a multi-variate regression model and best of class machine learning (ML) models. METHODS/STUDY POPULATION: In a prospective, case-cohort study, all trauma patients (pts) who arrived as level 1 or 2 trauma activations, from June 2018 to February 2020 were considered for study inclusion. A subset of pts who developed incident, first time, VTE and those who did not develop VTE within 90 days of discharge were identified. VTE were confirmed either by imaging or at autopsy during inpatient stay or post-discharge. Outcomes were defined as the development of symptomatic VTE (DVT and/or PE) within 90 days of discharge.A multi-variate Cox regression model and a best in class of a set of 5 different ML models (support-vector machine, random-forest, naives Bayes, logistic regression, neural network]) were used to predict VTE using models applied a) at 24 hours of injury date or b) on day of patient discharge. RESULTS/ANTICIPATED RESULTS: Among 393 trauma pts (ISS=12.0, hospital LOS=4.0 days, age=48 years, 71% male, 96% with blunt mechanism, mortality 2.8%), 36 developed inpatient VTE and 36 developed VTE after discharge. In a weighted, multivariate Cox model, any type of surgery by day 1, increased age per 10 years, and BMI per 5 points were predictors of overall symptomatic VTE (C-stat 0.738). Prophylactic IVC filter placement (4.40), increased patient age per 10 years, and BMI per 5 points were predictors of post-discharge symptomatic VTE (C-stat= 0.698). A neural network ML model predicted VTE by day 1 with accuracy and AUC of 0.82 and 0.76, with performance exceeding those of a Cox model. A naīve Bayesian ML model predicted VTE at discharge, with accuracy and AUC of 0.81 and 0.77 at time of discharge, with performance exceeding those of a Cox model. DISCUSSION/SIGNIFICANCE: The rate of inpatient and post-discharge VTEs remain high. Limitations: single institution study, limited number of patients, internal validation only, with the use of limited number of ML models. We developed and internally validated a ML based tool.Future work will focus on external validation and expansion of ML techniques.

Diagnosis and treatment of venous thromboembolism during pregnancy relate to genetic polymorphism.

Previous research had shown that age, a positive family history, comorbidities, major surgical operations, gestation, and use of several medications could increase the incidence of venous thromboembolism (VTE). With the development of medical and clinical individualized treatment, many people exposed to above risk factors did not develop VTE, suggested that genetic factors are also involved in the development of VTE. In this review, we aim to summarize VTE diagnosis and treatment in pregnancy women related to gene polymorphism. A comprehensive electronic search using PubMed, MEDLINE, EMBASE and Web of Science was conducted to find relevant journal articles with key search terms including: "pregnancy OR pregnant," "venous thromboembolism OR VTE," "deep vein thrombosis OR DVT," "pulmonary embolism OR PE," and "genetic OR gene." Prominent publications from establishment of database till present were analysed to achieve a deeper understanding of VTE during pregnancy relate to genetic polymorphism, and the information was then collated to form this review. The literature review revealed that inherited thrombophilia significantly associated with the development of VTE, especially the factor V Leiden (FVL) and prothrombin gene mutation (PGM). Furthermore, the role of methylenetetrahydrofolate reductase (MTHFR) gene mutation in the development of pregnancy-related VTE remains controversial, further study is required. In the present study, Marburg I polymorphism (G511E), c.1538G>A and c.1601G>A in Factor V (FV), JAK2V617F mutation were reported as an independent risk factor for VTE, there is no sufficient evidence to confirm the gene mutation is related to VTE during pregnancy, these factors appearing as another promising potential diagnostic marker of VTE during pregnancy. Besides, the dosages of heparin in the treatment of VTE during pregnancy need be adjusted according to gene polymorphism of these population, particularly FVL or PGM carriers, and this area is not studied deeply, it is worth further study. Inherited thrombophilia significantly associated with the development of VTE, especially the FVL and PGM, however the relation between MTHFR gene mutation and pregnancy-related VTE remains controversial, further study is needed. In addition, the dosages of heparin in the treatment of VTE during pregnancy suggested to adjusted based on gene polymorphism in FVL and PGM, and establish better prediction models is a direction of future research.

Predictive accuracy of boosted regression model in estimating risk of venous thromboembolism following minimally invasive radical surgery in pharmacological prophylaxis-naïve men with prostate cancer.

Venous thromboembolism (VTE) is a potentially life-threatening but preventable complication after urological surgery. Physicians are faced with the challenges of weighing the risks and benefits of thromboprophylaxis given scanty evidence for or against and practice variation worldwide. The primary objective of the study was to explore the possibility of a risk-stratified approach for thromboembolism prophylaxis following radical prostatectomy. A prospective database was accessed to cross-link venous thromboembolism events in 522 men who underwent minimally invasive prostatectomy between February 2010 and October 2021. A deterministic data linkage method was used to record events through electronic systems. Community Health Index (CHI) numbers were used to identify patients via electronic health records. Patient demographics and clinical characteristics such as age, comorbidities, Gleason staging, and readmission details accrued. VTE within 90days and development of a risk-stratified scoring system. All statistical analysis was performed using R-Statistical Software and the risk of VTE within 90days of surgery was estimated via gradient-boosting decision trees (BRT) model. 1.1% (6/522) of patients developed deep vein thrombosis or pulmonary embolism within 3months post-minimally invasive prostatectomy. Statistical analysis demonstrated a significant difference in the body mass index (p = 0.016), duration of hospital stay (p < 0.001), and number of readmissions (p = 0.036) between patients who developed VTE versus patients who did not develop VTE. BRT analysis found 8 variables that demonstrated relative importance in predicting VTE. The receiver operating curves (ROC) were constructed to assess the discrimination power of a new model. The model showed an AUC of 0.97 (95% confidence intervals [CI]: 0.945,0.999). For predicting VTE, a single-center study is a limitation. The incidence of VTE post-minimally invasive prostatectomy in men who did not receive prophylaxis with low molecular weight heparin is low (1.1%). The proposed risk-scoring system may aid in the identification of higher-risk patients for thromboprophylaxis. In this report, we looked at the outcomes of venous thromboembolism following minimally invasive radical prostatectomy for prostate cancer in consecutive men. We developed a new scoring system using advanced statistical analysis. We conclude that the VTE risk is very low and our model, if applied, can risk stratify men for the development of VTE following radical surgery for prostate cancer.

Prevention of venous thromboembolism in surgical patients: A proposal for a protocol based on the reality of a university hospital

Introduction: Venous thromboembolism (VTE) results from the formation of thrombi in the endothelial space, following factors related to endothelial injury, venous stasis and coagulation disorders. This scenario can result in deep vein thrombosis (DVT) and pulmonary thromboembolism (PTE), which is the third leading cause of cardiovascular death worldwide. Given the possibility of preventing VTE in the majority of in-hospital cases, it is recommended that every hospital has a formal strategy for VTE prevention, including in patients undergoing elective surgery. To this end, it is possible to use risk stratification scales, both for the development of VTE and the baseline risk of bleeding in post-operative patients. Objective: To provide an institutional protocol that is systematized and updated according to the main national and international literature on the prevention of venous thromboembolism in elective surgeries at the Júlio Muller University Hospital (HUJM/ UFMT). Materials and Methods: A protocol was drawn up based on a systematic analysis of up-to-date scientific evidence on thromboprophylaxis in elective surgeries, adapted to the routine of the Júlio Muller University Hospital (HUJM/UFMT), using the UpToDate, Pubmed and Cochrane Library platforms, as well as the Guidelines of the Brazilian Society of Angiology and Vascular Surgery (SBACV) and the American College of Chest Physicians (ACCP). Conclusion: The patient's risk of developing VTE is largely due to avoidable or predictable risk factors, depending on the type of surgery, mobilization time and risk of bleeding. The use of a protocol for the prevention of venous thromboembolism through risk stratification will allow greater individualization of the patient in relation to established prophylaxis, based on scientific evidence. Further studies on the subject are still needed, especially in the setting of elective surgery.

Incidence and Predictors of Venous Thromboembolism and Mortality in Saudi Lung Cancer Patients: A Retrospective Two-center Cohort Study

BACKGROUND: Venous thromboembolism (VTE) frequently occurs among individuals with cancer, and lung cancer (LC) is among the malignancies associated with the highest rate of VTE development. PURPOSE: The study’s objective was to ascertain the incidence rates of VTE and evaluate predictors of both VTE occurrence and mortality in LC patients. METHODS: This two-center retrospective study involved 497 Saudi Arabian patients diagnosed with LC aged ≥ 18 years. In this study, we calculated VTE incidence and mortality rates. We conducted Cox regression analyses (both univariate and multivariate) to explore the relationship between patient characteristics, VTE, and mortality using a 95% confidence interval (CI) and hazard ratios (HRs). RESULTS: Among 497 LC patients, 98 developed VTE, resulting in a prevalence rate of 9.8 per 100 person-years (PYs) with a 95% CI of 8.0–11.8. Furthermore, 280 patients passed away, resulting in a mortality rate of 26.5 per 100 PY with a 95% CI of 23.9–29.3. Low albumin levels, diagnosis of nonsmall cell LC (NSCLC), and high Eastern Cooperative Oncology Group (ECOG) performance status were all independent risk factors for VTE. Patients with VTE had notably higher mortality risk (HR: 3.10; 95% CI, 2.53–3.91; P &lt; 0.001) than non-VTE patients. The Kaplan–Meier analyses showed that the predicted median time of VTE occurrence was significantly higher in small cell LC (SCLC) (33.7 months) (P = 0.002 by the log-rank test) compared to NSCLC (28.7 months) patients. Furthermore, the estimated median time of survival for NSCLC patients (23.8 months) was significantly lower than in SCLC (29.7 months) (P &lt; 0.001 by the log-rank test). CONCLUSION: The study findings indicated that the VTE occurrence in LC patients was 9.8 per 100 PY, with a corresponding mortality rate of 26.5 per 100 PY. Reduced levels of albumin, ECOG performance status, and NSCLC emerged as significant risk factors of VTE. Patients who experienced VTE had a 3.10-fold higher mortality risk than non-VTE LC patients.

Incidence of thromboembolism and associated factors in multiple myeloma patients treated with immunomodulatory drugs: a retrospective analysis in Belo Horizonte, Brazil.

The use of immunomodulators in the treatment of multiple myeloma (MM) patients has been associated with venous thromboembolism (VTE). Due to the increase in mortality of cancer patients, venous thromboembolism is an important concern for newly diagnosed multiple myeloma (NDMM) patients. The aim of this study was to determine the incidence of thromboembolic events and evaluate associated risk factors among Brazilian NDMM patients using immunomodulators. Real-life retrospective cohort study in two Brazilian institutions with newly diagnosed multiple myeloma (NDMM) patients treated with immunomodulators from January 2009 to December 2019. Data was collected from patients' medical records for the period of 1 year, and Cox regression was performed to identify risk factors on the development of VTE. We included 131 patients of which there was a mean age of 61.5 years (SD 11.3), 51.9% female, and predominantly using thalidomide (97.7%) as immunomodulator. We found 9 VTE episodes among our patients, with a 12-month cumulative incidence of 6.97% (95% CI 3.41-12.24). Associated factors after multivariate analysis were recent sepsis, recent traumatic injury, previous VTE, and thromboprophylaxis. Our real-life retrospective cohort presented a low incidence of VTE among Brazilian NDMM patients treated with immunomodulators.

10091-COT-12 ELUCIDATING THE PATHOPHYSIOLOGY OF POST-OPERATIVE VENOUS THROMBOEMBOLISM IN IDH-WILDTYPE MALIGNANT GLIOMAS

Abstract BACKGROUND We have previously reported elevated expression of podoplanin and high incidence of post-operative venous thromboembolism (VTE) in IDH-wildtype gliomas (Watanabe et al., World Neurosurgery, 2019). Podoplanin binds to C-type lectin-like receptor-2 (CLEC-2) on the surface of platelets and induces platelet aggregation, potentially leading to the development of VTE. In the present report, we monitor serum podoplanin and CLEC-2 after surgery in malignant glioma patients to directly determine if this is the cause of post-operative VTE. METHODS Fourty-four malignant glioma patients undergoing surgery at the Department of Neurosurgery, Niigata University Hospital between April, 2018 and August, 2020 were assessed. Platelet counts as well as serum D-dimer, podoplanin, soluble CLEC-2, and C2PAC index (soluble CLEC-2 divided by platelet count) were measured within 10 days after surgery. Serum podoplanin and soluble CLEC-2 were assessed by enzyme-linked immunosorbent assay (ELISA). Values for IDH-wildtype glioma patients and IDH-mutant glioma patients were compared to patients undergoing microvascular decompression (MVD) and healthy volunteers (HV). RESULTS Post-operative VTE was observed in 8 out of 35 (23%) IDH-wildtype glioma patients, compared to 1 out of 9 (11%) IDH-mutant glioma patients. Serum soluble CLEC-2 levels (p = 0.0004) and C2PAC index (p = 0.0002) were significantly elevated in IDH-wildtype glioma patients compared to IDH-mutant glioma, MVD and HV groups. A C2PAC index threshold of 3.7 provide an 87.5% sensitivity and 51.9% specificity to predict post-operative VTE in IDH-wildtype gliomas. We serially monitored podoplanin and soluble CLEC-2 in select patients, and found that podoplanin is transiently elevated, followed by soluble CLEC-2 after surgery. CONCLUSION Platelet aggregation due to the activation of podoplanin-CLEC2 axis leads to post-operative VTE in IDH-wildtype malignant glioma patients. The C2PAC index is a potential biomarker for the early detection of VTE after surgery in these patients.

Non-O Blood Group and Pretreatment Risk of Venous Thromboembolism in Patients with Diffuse Large B-Cell Lymphoma

Introduction: Diffuse large B-cell lymphoma (DLBCL) is the most frequent aggressive non-Hodgkin lymphoma (NHL). It has been extensively documented that the risk of venous thromboembolism (VTE) is augmented in patients with aggressive lymphomas. The timing of VTE occurrence in this group of patients is highly variable and depends on diverse risk factors. Lately, it has been observed that ABO blood group type can have a prognostic impact on both thrombosis development and survival outcomes in patients with cancer. Therefore, the study aimed to examine the ABO blood group as a risk factor for VTE development in patients with DLBCL, to examine the relation between ABO blood groups and the timing of VTE development, and to investigate the association between ABO group type and treatment and survival outcomes. Methods: A total of 340 patients with DLBCL (newly diagnosed and relapsed) have been included in the study and all of them have been treated at the Lymphoma Center, Clinic for Hematology, University Clinical Center of Serbia. Data regarding VTE events were collected for all the patients included in the study, from the time of diagnosis to 3 months after the last cycle of therapy. ABO blood group has been determined before the treatment initialization. VTE was diagnosed objectively based on clinical examination, laboratory evaluation, and radiographic studies. Results: The median patients' age was 60 years (range, 19-89 years) and 52.9% were males. Newly diagnosed patients were dominant in the study population (94.4%). The majority of patients had advanced stage (stage III Ann Arbor 22.3% and stage IV 30.7%, respectively) of the disease. The median international prognostic index (IPI) was 2 (range, 0-5). Complete remission (CR) and partial remission (PR) were most commonly recorded (51.7% and 28.8%, respectively). The rate of VTE was 12.6% (43 patients), with the highest frequency of lower and upper extremity deep vein thrombosis (12 patients each). VTE was diagnosed before the initiation of specific hematological treatment in 54.5% of DLBCL patients, whilst 45.5% of DLBCL patients have been diagnosed with VTE following the hematological treatment initiation. The following distribution of ABO blood groups among DLBCL patients was detected: A blood group 39.4%, B blood group 17.6%, AB blood group 9.1%, and O blood group 33.8%. No significant association between VTE development and ABO group type was found (p=0.706) nor between VTE development and time of VTE development (p=0.895). The rate of VTE in DLBCL patients with A blood type was 4.7%, in B 2.1%, in AB 1.8%, and in O 4.1%, respectively (p=0.706). DLBCL patients with the non-O blood group developed VTE significantly more frequently prior to the hematological treatment commencement than after the treatment initiation (6.2% vs. 2.6%, p=0.003). Univariate logistic regression analysis showed that non-O blood type in DLBCL patients is a prognostic factor for VTE development prior to hematological treatment initiation (odds ratio (OR)=8.56, 95% confidence interval (CI): 1.92-38.21, p=0.005). Multivariate logistic regression model demonstrated that non-O blood type is an independent predictor of pretreatment VTE development in DLBCL patients (OR=18.33, 95% CI: 1.51-222.87, p=0.022). Therapy response of DLBCL patients was significantly associated with the ABO blood group (p=0.012) in the way that A and AB blood types were associated with unsatisfactory treatment response (no statistically significant association was found between ABO blood type and DLBCL patients' Ann Arbor stage, mediastinal involvement, bulky disease, extranodal disease, IPI, central nervous system involvement). Univariate regression analysis showed that A blood type is a predictor of unsatisfactory therapy response in patients with DLBCL (OR=1.85, 95% CI: 1.04-3.29, p=0.035). However, in multivariate regression model, this finding lost statistical significance. No significant association was observed regarding ABO blood type, progression-free survival, and overall survival in patients with DLBCL (p=0.398 and p=0.593, respectively). Conclusion: In DLBCL patients, non-O blood group is an independent predictor of VTE occurrence prior to initiation of a specific hematologic treatment. DLBCL patients with A blood group could be at risk of insufficient treatment response.

External Validation of PRISM Score in Multiple Myeloma Patients in a Community Setting: A Retrospective Cohort Study

Background: Newly diagnosed Multiple Myeloma (MM) patients have a 10 to 20 times higher risk of developing venous thromboembolism (VTE) than the general population. The pathogenesis may involve several factors such as activation of procoagulant factors, acquired activated protein C resistance, and inflammation. In addition to the general risk factors for venous thromboembolism such as older age, immobility, and surgery, some MM treatment-related factors such as the use of immunomodulatory drug therapy and abnormal cytogenetics contribute to the increased risk. The PRISM score (Prior VTE, Race, IMiD, Surgery, Metaphase Cytogenetics) is a risk prediction tool for VTE in MM and was published in 2022. The score ranges from 0 to 18 and patients were stratified into three groups: low (0), intermediate (1-6), and high risk (≥ 7). Our primary objective was to assess the external validity of the PRISM score in our community hospital setting. Methods: All consecutive newly diagnosed MM treated at Saint Vincent Hospital from 1/1/2008 to 12/22/2022 were included in our analysis. Patients receiving therapeutic anticoagulation for other indications or a diagnosis of VTE within 6 months preceding the MM diagnosis were excluded. Variables were collected through a retrospective chart review during MM treatment initiation. Model discrimination was assessed by calculating the area under the receiver operating characteristic curve (AUROC). Logistic regression was used to calculate the odds ratio (OR) of VTE occurrence in the risk prediction model. Results: A total of 214 patients with newly diagnosed MM and available data on VTE occurrence were included. The median age of our cohort at treatment initiation was 74 years (range 31- 96). The median BMI was 27.8. 56% were male, and 44% were female. The mean PRISM score was 2.9, and 73% of MM were IgG/IgA subtype. IMiD-based induction regimen was used in 63 % of patients. A total of 24 patients (11.2%) were diagnosed with VTE after treatment initiation, of which 8 (3.7%) patients had a previous history of VTE. Prophylactic aspirin was used in 53.8% and abnormal metaphase cytogenetics was identified in 13% of MM cases. The median time to VTE from induction therapy was 4.8 months. The PRISM score was low in 116 patients, intermediate in 89, and high in 9 patients. The AUROC of the model was 0.759 (95% CI, 0.644-0.874) (1). The cumulative incidence of VTE at 6 months, 12 months, and more than 1 year was 6%, 7%, and 11.2% of the patients respectively. Each 1-point increase in the score was associated with a significantly higher chance of VTE occurrence in the model [ HR= 1.53, 95% CI (1.27-1.85), P&amp;lt;0.001]. Among the parameters, patients with a history of VTE [ HR= 1.55, 95% CI (1.26-1.91), P&amp;lt;0.001] and with abnormal metaphase cytogenetics [HR= 2.35, 95% CI (1.37-4.05), P&amp;lt;0.001] had a higher strength of association with the development of VTE after induction (2). Furthermore, among 9 patients with a high-risk PRISM score (≥ 7), 7 (77%) developed VTE within the first 6 months after treatment initiation. Conclusions: Our findings suggest that PRISM [AUROC=0.75, 95% CI (0.644-0.874), P&amp;lt;0.001] score could statistically predict VTE outcomes in our patient population. Abnormal metaphase cytogenetics was a significant predictor of VTE in the validation cohort. Abnormal cytogenetics has been well established to be an indicator of aggressive tumor biology and proliferation in stroma-independent MM. It has been established to be a predictor of VTE in acute myeloid leukemia as well. Also, high-risk scores were predictive of earlier development of VTE after treatment induction. Our study strengthens the evidence of using PRISM as a predictive tool. Further studies are needed to enhance the sensitivity of our existing tool.

Derivation of a Risk Prediction Model for Venous Thromboembolism in Adult Patients with Acute Myeloid Leukemia

Background: Venous thromboembolism (VTE) is a well-established complication of malignancy associated with high morbidity. Many validated scoring systems exist to predict risk of VTE in patients with solid tumors. However, there are no models that can prospectively identify patients at high risk for the development of VTE in acute myeloid leukemia (AML). The purpose of this study was to determine risk factors for the development of VTE in a large cohort of AML patients and to develop a risk stratification model to predict VTE risk in this patient population. Methods: Adult patients presenting to the University of Wisconsin-Madison with newly-diagnosed AML from 1/1/2010 through 12/31/2021 were included in this retrospective cohort study. The primary end point was VTE within one year of diagnosis. Univariate logistic regression models were used to assess the association of each variable with development of VTE. Multivariate analysis was then completed using 16 candidate variables including demographics (sex, race, age at diagnosis), comorbidities (hypertension, diabetes, coronary artery disease, asthma/COPD), body mass index (BMI), Eastern Cooperative Oncology Group performance status (ECOG PS), history of solid organ or hematologic malignancy, smoking status, indwelling venous catheter, history of VTE, and baseline laboratory values (white blood cell count, hemoglobin, platelet count). Non-normally distributed continuous candidates were log10-transformed, then stepwise selection was used on a training set to choose predictive variables to construct a risk score to predict VTE within one year of AML diagnosis. Results: 326 patients with AML were included in the analysis. The median age at diagnosis was 60 years (range 19-92 years), 55% of the study population was male, and 94% were Caucasian race. 59 patients (18%) experienced VTE within one year of diagnosis. Age at diagnosis (OR 0.98, 95% CI, 0.963-0.998, p=0.033), BMI (OR 1.058, 95% CI, 1.02-1.10, p=0.005), hypertension (OR 0.522, 95% CI, 0.29-0.96, p=0.035) and platelets (OR 3.16, 95% CI, 1.44-6.94, p = 0.004) were individually associated with VTE. In a subgroup analysis of 278 patients with next generation sequencing data available, mutations in DNA methylation genes (DNMT3A, DNMT1, IDH1, IDH2, TET2) were associated with an increased risk of VTE (OR 1.911, 95% CI 1.017-3.591, p=0.0442, Table 1). A multivariate logistic regression model identified six independent predictors of VTE including platelet count &amp;gt;150,000 (OR 1.64, 95% CI 0.65-4.14, p=0.2953), BMI &amp;gt;25 (OR 3.10, 95% CI 1.22-7.86, p=0.0173), hypertension (OR 2.17, 95% CI 1.03-4.55, p=0.0410), history of other cancer (OR 1.72, 95% CI, 0.74-4.01, p=0.2109), diabetes (OR 2.05, 95% CI 0.73-5.73, p=0.1718), and ECOG PS (OR 1.33, 95% CI, 0.66-2.65, p=0.4263). Subsequently, a risk score was constructed from the multivariable model (3*platelets&amp;gt;150 + 8*BMI&amp;gt;25 + 5*NoHTN + 3*NoOtherCancer + 4*Diabetes + 1*ECOG0). Patients were categorized into three groups: low (score&amp;lt;9), moderate (9score&amp;lt;12), and high (score) risk of developing VTE (Table 2). Rates of VTE within one year of AML diagnosis were 3.2%, 16.4%, and 23.6% in the low, moderate, and high risk groups respectively. The model had an external AUC=0.704 when applied to our test set. Conclusions: Our study demonstrates a high rate of early VTE in patients with AML at 18%, highlighting the importance of identifying those at higher risk which would allow for early screening, patient education, and consideration of thromboprophylaxis. On multivariable analysis, we found that normal or elevated platelet count &amp;gt;150, BMI 25, and diabetes were associated with an increased risk of early VTE. Surprisingly, higher ECOG PS, history of malignancy, and hypertension were associated with a decreased risk of early VTE in our cohort. A risk prediction model incorporating these findings was able to identify patients with low, moderate, and high risk of VTE. This model may help with clinical decision making, such as the consideration of thromboprophylaxis for patients with a moderate or high risk score. However, prospective validation of this model in a larger cohort of patients is needed. In summary, we propose a risk prediction model for the development of VTE in AML that can now be validated in order to provide optimal supportive care for this patient population.

Predictors and Timing of Venous Thromboembolism in Lymphoma

Introduction Cancer associated thrombosis (CAT) is common in lymphoma, but the risk is not well characterized. While prophylactic anticoagulation is recommended in certain solid tumors, routine prophylaxis is not practiced in hematologic malignancies. The Kohrana CAT risk score considers lymphoma a single entity. We aimed to identify the incidence rate of venous thromboembolism (VTE) and risk factors in lymphoma patients at our institution. Methods Patients diagnosed with lymphoma between 2018 and 2022 were identified through our institution's tumor registry. Using automated text search from our electronic medical record (EPIC®) combined with natural language processing review, VTE events were identified from 90 days before and up to one year(y) after initiation of chemotherapy initiation, or diagnosis date if no chemotherapy was administered. VTE events included lower extremity deep vein thrombosis (DVT) or pulmonary embolism (PE). Events were reviewed and adjudicated manually by us. We report time to event analysis and survival analysis using Kaplan-Meier curve. The study was censored at one year. Univariate and multivariate analyses were performed using COX-regression model. We evaluated the effect of indolent versus aggressive lymphoma, stage, age, sex, race, ethnicity, white blood cell count, hemoglobin, and platelet count. Results We identified 879 patients(pts) with lymphoma; of those, 378 pts had indolent lymphoma (I-Lym) and 501 pts had aggressive lymphoma (A-Lym). Median age was 61y. 464 pts (52.8%) were above 60 y, 477 pts (54.3%) were males, and 325 pts (37.0%) were Hispanic. Race was distributed as follows: 89.5% white, 9.1% Black, and 1.4% other. 56.9% had advanced stage lymphoma. VTE occurred in 4.9% (n=43) of the overall population within 12 months. The incidence was higher in A-Lym (7.2%, n=36) compared with I-Lym (1.9%, n=7), p&amp;lt;0.001. For both A-Lym and I-Lym, 32.6% of the VTE events occurred prior to diagnosis or initiation of chemotherapy. Among patients who developed thrombosis after the chemotherapy start date, the median time to thrombosis was 39 days. In a univariate analysis (Table 1) for thrombosis-free survival, age&amp;gt;60, receiving chemotherapy and A-Lym, were all associated with higher risk of thrombosis (p&amp;lt;0.05). In the multivariate analysis, only, age&amp;gt;60, and A-Lym remained significant in predicting thrombosis (HR: 3.48, 95%CI: 1.41, 8.61, p=0.007). Hemoglobin &amp;lt;10, platelet count &amp;gt;350, white blood cell count &amp;gt;11, advanced stage, and chemotherapy administration were not significant risks of thrombosis. In multivariate analysis for overall survival (Table 2), development of VTE was associated with increased risk of mortality (HR: 2.59, 95%CI: 1.38, 4.87, p=0.003). This relationship of VTE and mortality was observed independently in both I-Lym and A-Lym. As expected, A-Lym, age&amp;gt;60, male sex, and advanced stage all predicted worse survival in our lymphoma population (p&amp;lt;0.05 for all). Of note, hemoglobin &amp;lt;10 and white blood cell count &amp;gt;11, did not predict VTE in lymphoma but did predict poor OS. Conclusion Lymphoma is associated with a clinically relevant rate of CAT, but incidence is significantly higher in A-Lym compared with I-Lym with a third of events occurring prior to chemotherapy. The hematologic parameters of the Khorana Score (WBC, Hgb, platelet count) did not correlate with incidence of CAT in lymphoma, neither did chemotherapy. Development of CAT during therapy, in multivariate analysis for both A-Lym and I-Lym, was associated with a marked reduction in OS. These points suggest that the thrombotic risk is an inherent property of lymphoma biology in at least some cases, leading to an increased risk of CAT as well as reduced OS. We do not propose that CAT-related mortality is driving the reduced OS, but more likely a marker of poorer prognosis. Limitations: This was a single center/ single dataset and these findings should be considered a derivation cohort, and should be verified with independent additional datasets. If our findings are verified, prospective studies to assess benefit of prophylactic anticoagulation in aggressive lymphoma may be warranted.

Risks for Venous Thromboembolism with Immune Checkpoint Inhibitor Therapy

Background: Immune checkpoint inhibitor therapy (ICI) has been variably associated with increased risk of VTE, with some reports suggesting increased risk and others suggesting risk is not different from the baseline venous thromboembolism (VTE) risk in unselected ambulatory patients with cancer. Methods: Patients treated with ICI at our institution between 2009 and 2022 were retrospectively identified. Standard baseline characteristics (age, sex, race/ethnicity, BMI), cancer type and stage, type of ICI, KS risk score variables not already captured including white cell count, hemoglobin, and platelet count at time of initiating ICI therapy, as well as other patient and treatment characteristics were collected. Those with history of VTE prior to start of ICI were removed from the analysis population; anticoagulation after starting ICI was a time dependent factor. Cumulative incidence of VTE with death as a competing risk was determined using Fine and Gray technique. Univariate analysis for baseline characteristics was completed. Characteristics that were statistically significant at the 0.1-level or less were carried forward as candidate predictors in multivariable, competing risks models of VTE. Results are presented as hazard ratios with 95% confidence intervals adjusted for multiple comparisons against a reference group. Results: Of 12,007 patients starting ICI therapy, 10,638 were analyzed with median follow-up of 25.1 months. The majority of tumor types included lung (30.3%), skin (15.8%; melanoma, squamous cell), gastrointestinal (11.7%), and genitourinary (11.6%). The most frequently used ICI agents were the anti-PD-1 monoclonal antibodies pembrolizumab (49.7%) and nivolumab (31.8%). The overall cumulative incidence estimates of VTE are summarized in Figure 1. The estimate at six months was 7.6% (95% CI: 7.1 to 8.1%); at one year: 11.1% (95% CI: 10.5 to 11.8%); and at two years 13.8% (95% CI: 13.0 to 14.5%). Among the 1,328 patients who developed VTE, the median time after starting ICI therapy was 5.4 months [IQR: 1.8 to 12.0 months]. Univariate comparison findings carried forward as candidate predictors in the multivariable analyses included sex, age, BMI, race, history of prior anticoagulant therapy (before ICI start), cancer type, disease stage, ICI therapy (by drug), KS, and platelets. The first multivariable model using all predictors identified gender, Khorana risk score, and race as no longer significant. The second model examined the inter-relationships between remaining predictors and the incidence of VTE; as the KS is partially comprised of cancer type, BMI, and platelets, having these as separate predictors removed the influence of the Khorana score since they would provide similar information. Predictors of VTE identified in this model included type of ICI with the use of ipilumumab associated with the highest risk with HR of 1.90 (95% CI: 1.33-2.71) and durvalumab the lowest HR 0.59 (95% CI:0.36-0.96), when compared with pembrolizumab. Type of cancer, stage of cancer, BMI, and high platelet count were also predictive. Starting anticoagulation at the time of or after beginning ICI but not for treatment of VTE was associated with approximately a 40% reduced hazard of VTE compared to patients who had not yet or never started anticoagulation. (HR: 0.59, 95% adj. CI: 0.48 to 0.73). (Table 1) Conclusion In this large sample of patients, the use of ICI in VTE naïve patients was associated with an increased risk of VTE, with a cumulative incidence of 7.6% at 6 months compared with a baseline 3-4% risk in general ambulatory patients with cancer. Type of ICI treatment was associated with VTE risk, as was stage of cancer. The individual KS risk predictors of cancer type and BMI were predictive but only elevated platelet count was associated with increased VTE risk-hemoglobin and white cell count were not. Importantly, those that started anticoagulation for reasons other than development of VTE had a significant reduction in VTE risk, suggesting that anticoagulant prophylaxis may be indicated in those patients with multiple risk factors in the setting of ICI treatment. Further analysis of these data will help identify at risk patients starting treatment with ICI who will benefit from VTE prophylaxis.

The Choice of Anticoagulant at First Recurrence Does Not Alter the Risk for the Second Recurrence

Introduction : Venous thromboembolism (VTE), encompassing deep venous thrombosis (DVT) and pulmonary embolism (PE), is a major public health hazard, with up to 30-50% of patients with unprovoked VTE experiencing a recurrent VTE event. These recurrent VTE events are associated with significant morbidity and mortality. However, transition strategies to second-line anticoagulation regimens following the first recurrence on anticoagulation have not been well studied. We sought to examine whether rates of the second VTE recurrence were different in those patients who changed their anticoagulation regimen from those who did not . Methods: With an IRB approval for the study, we created a database of all patients 18 years and older diagnosed with the first recurrent VTE at a large tertiary academic hospital between January 1, 2010, and December 31, 2019. The collected data was de-identified and compiled in a secure, standardized institutional database. We assessed the anticoagulation status at the time of and immediately following the first VTE recurrence, and identified patients who were switched to a different anticoagulant regimen. We used Fisher's exact test to evaluate proportions. Statistical significance was set at p&amp;lt;0.05. Results:We identified 138 patients with the first VTE recurrence. Of these patients, 114 (83%) developed DVT, 7 (5%) PE, and 17 (12%) both DVT and PE. Mean age was 63 years at the time of first VTE; 70 (51%) were female. Racial/ethnic representation was 84 (61%) White, 46 (33%) Black, and 133 (96%) non-Hispanic. The majority of patients had cardiovascular risk factors, including hypertension 80 (58%), hyperlipidemia 44 (32%), ordiabetes 40 (29%). Among 138 patients, 32 (23%) had active cancer, May-Thurner syndrome or inferior vena cava (IVC) atresia were reported in 13 (9%) of cases, and 21 (17%) underwent IVC filter placement at the time of the first VTE recurrence. The median follow-up time after diagnosis of a second VTE was 5 years. Following the first VTE recurrence, 19 (14%) of patients switched to a different anticoagulant agent, 7 (5%) had the dose of the anticoagulant adjusted, 1 (0.7%) was given a different INR target, and one had a change in the frequency of administration. The second VTE occurred in 49 (46%) patients who remained on the same anticoagulation regimen and in 3 (16%) who had the agent changed, in 5 who had dose of anticoagulant changed, in 1 (100%) each who had frequency or INR target changed. The association between unprovoked first VTE and the development of the second VTE was not significant (p= 0.85, Fisher's exact test). 49 (36%) of patients had at least one bleeding episode requiring the interruption of anticoagulation or hospitalization. Of those, 43 (88%) occurred while on an anticoagulant. Conclusion: The choice of an anticoagulant regimen after the first VTE recurrence does not impact the rate of the second recurrence.

Incidence of Venous Thromboembolism in Pediatric Cancer Patients with COVID-19: MD Anderson Cancer Center Experience

Background: Patients with COVID-19 are at increased risk of venous thromboembolism (VTE) due to a hypercoagulable state. Multisystem inflammatory syndrome in children (MIS-C) is a unique entity in the pediatric population affected by COVID-19 which also increases the risk of VTE. This has been described in the literature and guidelines have been established across different institutions regarding anticoagulation prophylaxis. It is well known that cancer increases the risk of VTE greater than four-fold to that of the general population and, for patients receiving active chemotherapy, the risk is up to 6.5 times greater. Studies have shown that adults patients with active cancer and COVID-19 infection had increased risk of mortality due to VTE associated complications. Contrary to that, some reports have shown that incidence of VTE does not appear to be increased in adults with cancer compared to non-cancer patients. Hence, the data is yet scarce as well as conflictive. Anecdotally, we observed a decreased number of cases of VTE associated with COVID-19 infection in our pediatric cancer patients. There are limited studies that evaluate COVID-19 infection with VTE incidents and complications in this population. In this study, we report a retrospective analysis of pediatric cancer patients at our center during a span of three years to determine the incidence of COVID-19 infection with VTE and related complications. Objectives: Primary objective: Investigate the incidence of VTE in pediatric cancer patients with COVID-19 infection. Secondary objectives: Investigate COVID-19 associated complications, comorbidities in pediatric cancer patients. Methods: This is a single center retrospective cohort study. Data was extracted from COVID-19 database established at MD Anderson Cancer Center since the start of the pandemic. Patients 0 to 18 years of age affected by COVID-19 infection who were seen at MD Anderson Cancer Center from March 2020 to March 2023 were included. VTE inclusion criteria was development of thrombosis event from 14 days prior up to three months after COVID-19 infection. All cancer types were included. ICD 10 codes for diagnosis of COVID-19 infection and VTE were used to search for patients meeting the above criteria. Foundry database software was used to analyze the data and validation was done by the software checks by two independent reviewers and accordingly modified our search terms. Results: Three cohorts ( figure 1) were identified; patients with COVID-19 infection with or without VTE (Group 1), patients with VTE with or without COVID-19 infection (Group 2), and patients with both COVID-19 infection and VTE (Group 3). From group 1 (pediatric cancer with COVID infection with and without VTE), a total of 235 cancer patients ranging between 0 to 18 years of age were found affected by COVID-19 infection (Mean = 11.1 years, median = 12 years). The majority of patients were Caucasians (57.4%). Fifty percent of patients were male. From group 2 (pediatric cancer patients with VTE with or without COVID-19 infection), 272 patients were identified who had developed VTE of which 55.5% were males, and 54% were Caucasians with similar age distribution (mean = 13.1 years, median =15 years). In our study population, we identified three patients with VTE events who had COVID-19 infection (group 3, see table 1). Conclusion: The incidence of VTE in pediatric cancer patients affected by COVID-19 infection was lower compared to COVID-19 negative pediatric cancer patients. Our findings suggest that COVID-19 infection does not appear to be an additional risk factor for the development of VTE in pediatric cancer patients. Further studies are currently ongoing to investigate co-morbidities and COVID-associated complications other than VTE.

Circulating Tumor DNA and Risk of Venous Thromboembolism in Locally Advanced Rectal Cancer

Venous thromboembolism (VTE) is a common complication in cancer patients, which negatively affects treatment delivery and, consequently, prognosis. The pathophysiology of cancer-associated thrombosis (CAT) is extremely complex, relying on cytokine release in response to interactions between tumor cells and macrophages, thus leading to endothelial damage and activation of coagulation. Several risk factors may contribute to VTE risk, including tumor types, advanced stage, and anti-cancer treatments. Anti-angiogenic agents or combination of systemic chemotherapy and concomitant radiotherapy (CT-RT), for instance, are well-established risk factors across different malignancies. Colorectal cancer (CRC) is not listed as a high-risk VTE tumor according to pivotal risk assessment models, although retrospective studies showed a VTE rate of around 20%. Consequently, considering the high prevalence of the disease, VTE in CRC represents a main burden in terms of morbidity, increased healthcare costs, and mortality. Rectal cancer (RC) comprises approximately 30% of all CRC. The treatment of locally advanced disease (LARC) consists of a multimodal approach which includes chemotherapy, radiotherapy, and surgery. In the context of CRC management, circulating tumor DNA (ctDNA) is a fast-growing tool able to detect minimal residual disease, useful for improving patients' stratification and prognosis. Moreover, its determination at the time of diagnosis may represent a surrogate of tumor burden, potentially increasing the risk of VTE compared to ctDNA negative patients. Due to the paucity of prospective data of VTE in LARC, the aim of this analysis is to describe the rate of VTE and the potential association between ctDNA levels at baseline and VTE occurrence. We conducted a prospective observational study enrolling patients with LARC managed with neoadjuvant CT-RT (capecitabine 1650 mg/m2 concomitant with 50,4 Gy pelvic long course radiotherapy), surgery, plus/minus adjuvant chemotherapy at European Institute of Oncology (IEO) between November 2014 and November 2019. Blood samples for ctDNA were obtained at pre-planned timepoints: baseline (T0), end of CT-RT (T1), after surgery (T2), end of adjuvant chemotherapy (T3). ctDNA was extracted from plasma and mutations detected on tumor biopsy (KRAS, NRAS, BRAF, PIK3CA) were evaluated on ctDNA. Among other clinical information, VTE events were collected, including pulmonary embolism (PE), deep vein thrombosis (DVT) and visceral venous thrombosis (VVT). VTE was counted when occurred after or whitin 30 days before LARC diagnosis. The ctDNA value, defined as variant allele frequency (VAF) in a targeted mutation, was analyzed for correlation with clinical outcomes and VTE events. Median baseline ctDNA value was set as threshold to subdivide patients in VAF high and VAF low. We enrolled 111 patients. Sixty-one (55%) patients harboring tumoral tissue mutations underwent liquid biopsy. KRAS mutation was the most frequent one (42%), followed by NRAS (7%) and PIK3CA (5%). Fifty-one patients (83%) had a clinical node positive disease. Baseline Khorana Score (KS) was 0 in 54 patients (88%) and 1 in 7. Median ctDNA value at T0 was 0.11 ng/2ml (range: 0.00 - 17.40). After a median follow up of 82 months, 9 VTE events (15%) were diagnosed, 4 PE, 3 DVT and 2 VVT. The median time from diagnosis to VTE event was 14 months (IQR 6 - 51). VTE occurrence was associated with VAF high at baseline, even though not statistically significant (Hazard Ratio [HR]: 2.85; 95% CI: 0.71-11.4, p value = 0.14). Looking specifically at KRAS mutant patients, 6 VTE events were observed, all experienced by VAF high patients (HR not estimable, p value = 0.001). Considering the overall population, VTE rate was 14% and no statistical differences were observed for VTE development according to mutational profile. In our prospective study on LARC patients, VTE was associated with high levels of ctDNA at diagnosis, although not statistically significant. However, the association was significant in KRAS mutant tumors, which may represent a subset of patients with higher risk of thromboembolic complications. Prospective translational studies using deeper molecular techniques and wider populations are required to define the role of ctDNA as additional predictive tool to stratify VTE risk in cancer patients.

RNA-sequencing to discover genes and signaling pathways associated with venous thromboembolism in glioblastoma patients: A case-control study

BackgroundGlioblastoma patients are at high risk of developing venous thromboembolism (VTE). Tumor-intrinsic features are considered to play a role, but the underlying pathophysiological mechanisms remain incompletely understood. ObjectivesTo identify tumor-expressed genes and signaling pathways that associate with glioblastoma-related VTE by using next generation RNA-sequencing (RNA-Seq). MethodsThe tumor gene expression profile of 23 glioblastoma patients with VTE and 23 glioblastoma patients without VTE was compared using an unpaired analysis. Ingenuity Pathway Analysis (IPA) core analysis was performed on the top 50 differentially expressed genes to explore associated functions and pathways. Based on full RNA-Seq data, molecular glioblastoma subtypes were determined by performing cluster analysis. ResultsOf the 19,327 genes, 1246 (6.4 %) were differentially expressed between glioblastoma patients with and without VTE (unadjusted P < 0.05). The most highly overexpressed gene was GLI1, a classical target gene in the Sonic Hedgehog (Shh) signaling pathway (log2 fold change: 3.7; unadjusted P < 0.0001, adjusted P = 0.219). In line, Shh signaling was among the top canonical pathways and processes associated with VTE. The proportion of patients with the proneural/neural glioblastoma subtype was higher among those with VTE than controls. ConclusionShh signaling may be involved in the development of glioblastoma-related VTE.

Guidelines in Practice: Prevention of Venous Thromboembolism.

Venous thromboembolism (VTE), a condition involving deep vein thrombosis and embolism, can cause death when left untreated. Hospitalized patients and those who have recently undergone surgery or have a cancer diagnosis are at increased risk for VTE development. The updated AORN "Guideline for prevention of venous thromboembolism" provides perioperative nurses with a variety of evidence-based recommendations associated with the topic. This article provides an overview of the guideline and discusses recommendations for a VTE protocol, VTE and bleeding risk assessments, pharmacologic and mechanical VTE prophylaxis, postoperative ambulation, and patient and family education. It also includes a scenario that illustrates the importance of the VTE assessment and the use of mechanical prophylaxis for high-risk patients undergoing operative or other invasive procedures. Perioperative nurses should review the guideline in its entirety and implement recommendations in operative and procedural settings.