Rate Of Venous Thromboembolism In Patients Research Articles

The Use of Aspirin for Venous Thromboembolism Prophylaxis in Patients Who Have Morbid Obesity Undergoing Primary and Revision Total Joint Arthroplasty

BackgroundVenous thromboembolism (VTE) poses a major clinical concern due to its life-threatening nature, and obese and morbidly obese patients are thought to be at an increased risk for VTE. The aims of this study were twofold; first, to explore VTE rates in patients who have a body mass index (BMI) > 40 undergoing primary and revision total joint arthroplasty, and second, to investigate aspirin (ASA) efficacy and safety. MethodsWe identified all patients (n = 4,672) who had a BMI > 40 who underwent primary and revision total joint arthroplasty from 2016 to 2022 at a single academic tertiary care center. Patients were stratified by BMI groups: 40 to 44.9 (n = 3,462), 45 to 49.9 (n = 935), and 50+ (n = 275). The primary outcome was any VTE event within 90 days postoperatively. The secondary outcome consisted of wound complications within 90 days postoperatively. ResultsThe total VTE rate was 0.4% (n = 21) and did not differ statistically between the BMI groups (0.4 versus 0.4 versus 0.7%, P = .669). The VTEs consisted of 6 deep venous thromboses (DVTs), 14 pulmonary embolisms, and one concomitant deep venous thrombosis and pulmonary embolism. The VTE rates were not statistically different between patients who received aspirin 325 mg 0.5% (n = 9), aspirin 81 mg 0.2% (n = 1), aspirin + anticoagulant (AC) 0.5% (n = 6), and AC alone 0.4% (n = 5) (P = .954). In addition, wound complications did not differ significantly between patients who received ASA 325 mg, ASA 81mg, ASA + AC, or AC alone (1.6 versus 1.0 versus 1.8 versus 1.1%, P = .351). ConclusionsThe use of aspirin 325 and 81 mg was found to have similar VTE rates as aspirin + ACs and ACs alone, with no significant increase in wound complications. In patients who have a BMI > 40, the use of aspirin is a safe option for VTE prophylaxis and should be prescribed in the context of the patient who has other risk factors for VTE.

Venous thromboembolism in Cushing syndrome: results from an EuRRECa and Endo-ERN survey.

Patients with Cushing syndrome (CS) are at increased risk of venous thromboembolism (VTE). The aim was to evaluate the current management of new cases of CS with a focus on VTE and thromboprophylaxis. A survey was conducted within those that report in the electronic reporting tool (e-REC) of the European Registries for Rare Endocrine Conditions (EuRRECa) and the involved main thematic groups (MTG's) of the European Reference Networks for Rare Endocrine Disorders (Endo-ERN) on new patients with CS from January 2021 to July 2022. Of 222 patients (mean age 44 years, 165 females), 141 patients had Cushing disease (64%), 69 adrenal CS (31%), and 12 patients with ectopic CS (5.4%). The mean follow-up period post-CS diagnosis was 15 months (range 3-30). Cortisol-lowering medications were initiated in 38% of patients. One hundred fifty-four patients (69%) received thromboprophylaxis (including patients on chronic anticoagulant treatment), of which low-molecular-weight heparins were used in 96% of cases. VTE was reported in six patients (2.7%), of which one was fatal: two long before CS diagnosis, two between diagnosis and surgery, and two postoperatively. Three patients were using thromboprophylaxis at time of the VTE diagnosis. The incidence rate of VTE in patients after Cushing syndrome diagnosis in our study cohort was 14.6 (95% CI 5.5; 38.6) per 1000 person-years. Thirty percent of patients with CS did not receive preoperative thromboprophylaxis during their active disease stage, and half of the VTE cases even occurred during this stage despite thromboprophylaxis. Prospective trials to establish the optimal thromboprophylaxis strategy in CS patients are highly needed. The incidence rate of venous thromboembolism in our study cohort was 14.6 (95% CI 5.5; 38.6) per 1000 person-years. Notably, this survey showed that there is great heterogeneity regarding time of initiation and duration of thromboprophylaxis in expert centers throughout Europe.

Padua prediction score may be inappropriate for VTE risk assessment in hospitalized patients with acute respiratory conditions: A Chinese single-center cohort study

BackgroundThe Padua Prediction Score (PPS) recommended by the guidelines lacks effective external validation in a Chinese cohort. This study sought to assess the accuracy of the PPS to predict venous thromboembolism (VTE) risk in medical inpatients with acute respiratory conditions. MethodsThis consecutive cohort study included 1,574 inpatients from January to August 2019. The occurrence rate of VTE in patients classified at high-risk and low-risk groups according to PPS and Caprini risk assessment model (RAM) was compared. The discriminatory capability of the RAMs was evaluated in all the patients and the subgroup without pharmacological prophylaxis. Reclassification parameters were also used to assess the clinical utility. Results170 (10.8%) patients were objectively confirmed as having VTE during hospitalization. The incidence rate of VTE in low-risk patients was 6.3% by PPS, which was significantly higher than that by Caprini RAM (2.6%, p < 0.001). The area under the curve (AUC) for PPS and Caprini RAM was 0.714 (95%CI, 0.672–0.756) and 0.760 (95%CI, 0.724–0.797), respectively (p = 0.003). The AUC of Caprini RAM was larger than PPS even in subgroups without pharmacological prophylaxis (0.774 vs 0.709, p = 0.002). Compared with Caprini RAM, the net reclassification index was estimated at 0.037 (p = 0.436), and integrated discrimination improvement was 0.015 (p = 0.495) by PPS. ConclusionsAccording to our cohort study, PPS may not be appropriate to predict VTE risk in hospitalized patients with acute respiratory conditions. An accurate, widely applicable, validated RAM needs to be further constructed in Chinese medical inpatients.

Risk of venous thromboembolism in pregnant patients with active malignancy: A systematic review and meta-analysis.

Cancer currently occurs in about 1 in 1000 pregnancies. Both active malignancy and pregnancy are individual risk factors for venous thromboembolism (VTE). The purpose of this systematic review/meta-analysis was to evaluate the rate of VTE in pregnant patients with active malignancy compared with pregnant patients without malignancy. Embase, Medline/PubMed, Cochrane Database, and clinicaltrial.gov were search by a trained librarian from inception until June 2021, and limited to English and French language human studies using keywords related to pregnancy, neoplasm, and thrombosis. This study was prospectively registered with PROSPERO (CRD42021245886). Title, abstract, and full-text review was performed using the Covidence data management system. Two authors reviewed the studies independently. Of the 3821 articles screened, seven cohort studies were included that reported VTE rate in patients with active malignancy in pregnancy. A total of 5928 individuals had active malignancy and pregnancy. Active malignancy in pregnancy significantly increased the odds of a VTE (odds ratio [OR] 6.8, 95% confidence interval [CI] 3.8-12.1). Specifically, patients with thyroid (OR 2.7, 95% CI 1.3-6.3), cervix (OR 6.6, 95% CI 2.4-18.0), or other gynecological (OR 10.6, 95% CI 4.4-25.8) cancers; Hodgkin's lymphoma (OR 8.7, 95% CI 3.3-23.4); or acute leukemia (OR 17.1, 95% CI 10.9-26.8) all had increased odds, whereas those with brain cancer (OR 6.1, 95% CI 0.4-98.2), breast cancer (OR 2.5, 95% CI 0.3-17.4), malignant melanoma (OR 5.5, 95% CI 0.3-88.1), or non-Hodgkin's lymphoma (OR 3.2, 95% CI 0.8-12.9) malignancies did not have statistically significant increased odds for VTE. No studies reported whether prophylactic anticoagulation was used during pregnancy in this population; nor did they report timing in pregnancy of the VTE. The absolute risk for VTE in those with active malignancy was 0.9% compared with 0.2% in those without active malignancy in pregnancy. Pregnancy with active malignancy confers a significant increased risk for VTE compared with pregnancy alone. Given this finding, prophylactic anticoagulation during pregnancy and postpartum could be considered in this patient population. Data are underpowered to make firm recommendations per cancer type.

Implementation of routine venous thromboembolism prophylaxis during neoadjuvant chemotherapy for patients with ovarian cancer

ObjectiveTo compare the venous thromboembolism (VTE) rate in patients with ovarian cancer undergoing neoadjuvant chemotherapy before and after implementing routine thromboprophylaxis. MethodsThis is a quasi-experimental pre-post study evaluating the VTE rate in patients with ovarian cancer who received neoadjuvant chemotherapy following a quality improvement initiative of routine thromboprophylaxis within a single healthcare system that started in January 2017. Patients were excluded if VTE was diagnosed before initiating chemotherapy. Patient factors and perioperative variables of interest were investigated for their association with VTE through univariate and multivariate models. ResultsOf the 136 patients in the pre-implementation group, 3.7% (n = 5) received thromboprophylaxis. Of the 154 patients in the post-implementation group, 65.6% (n = 101) received thromboprophylaxis. Provider compliance varied from 51% in 2019 to 79.3% in 2021. The overall rate of VTE, from the start of chemotherapy to the end of treatment, was 21.3% (n = 29) pre- and 8.4% (n = 13) in the post-implementation group (p < 0.01). There was no difference in major bleeding events between groups (0% vs. 0.68%, p = 0.63). On univariate analysis, thromboprophylaxis (OR 0.19; 95% CI 0.07–0.52) and post-implementation period (OR 0.34; 95% CI 0.17–0.69) were associated with a decreased risk of any VTE during primary treatment. On multivariate analysis, only thromboprophylaxis remained significantly associated with reduced VTE rates (aOR 0.19; 95% CI 0.07–0.53). ConclusionRoutine thromboprophylaxis during neoadjuvant chemotherapy is associated with reduced risk of VTE throughout primary treatment and is not associated with increased bleeding events.

Venous Thromboembolism After Abdominal and Minimally Invasive Large Specimen Hysterectomy

To investigatethe incidence of venous thromboembolism (VTE) in patients undergoing large specimen hysterectomy for benign indications. To evaluate the impact of route of surgery and operative time in the development of VTE in this population. Retrospective cohort study (Canadian Task Force Classification II2) of targeted hysterectomy data prospectively collected from the American College of Surgeons National Surgical Quality Improvement Program involving over 500 hospitals across the United States SETTING: National Surgical Quality Improvement Program Database PATIENTS: Women aged 18 years or older undergoing hysterectomy for benign indications between 2014 and 2019. Patients were further classified into four groups according to uterine weight: <100g, 100-249g, 250g-499g, and specimens ≥500g. Current Procedural Terminology codes were used to identify cases. Variables including age, ethnicity, body mass index, smoking status, diabetes, hypertension, blood transfusion, and American Society of Anesthesiologists classification system scores were collected. Cases were stratified by route of surgery, operative time, and uterine weight. A total of 122,418 hysterectomies occurring between 2014-2019 were included in our study, of which 28,407 (23.2%) patients underwent abdominal, 75,490 (61.7%) laparoscopic, and 18,521 (15.1%) vaginal hysterectomy. The overall rate of VTE in patients with large specimen hysterectomies (≥500g) was 0.64%. After multivariable adjustment, there was no significant difference in the odds of VTE between uterine weight groups. Only 30% of the surgeries with uterine weight above 500g were performed with minimally invasive surgical routes. Patients who underwent minimally invasive hysterectomy had lower odds of VTE via laparoscopic (aOR 0.62; CI:0.48-0.81) and vaginal (aOR 0.46; CI:0.31-0.69) routes compared to laparotomy. Prolonged operative time (>120 min) was associated with an increased odds of VTE (aOR 1.86; CI:1.51-2.29). The occurrence of VTE after benign large specimen hysterectomy is rare. The odds of VTE is higher with longer operative times and lower with minimally invasive approaches even for markedly enlarged uteri.

Low-Dose Heparin Infusion as Venous Thromboembolism Chemoprophylaxis in Patients With Blunt Cerebrovascular Injury

IntroductionBlunt cerebrovascular injury (BCVI) can result in devastating stroke. Because of operative inaccessibility, the most common treatment for BCVI is aspirin or a low-dose systemic heparin infusion. While it is assumed that low dose heparin infusion imparts venous thromboembolism (VTE) prophylaxis, this has not been evaluated in the BCVI population. The purpose of this study was to evaluate VTE rates in patients receiving low-dose heparin infusion as treatment for BCVI. MethodsPatients diagnosed with BCVI between 2014 and 2018 were reviewed for initiation of low-dose systemic heparin treatment. VTE was defined as a deep vein thrombosis or pulmonary embolism. BCVI patients without systemic heparin treatment were compared to BCVI patients with heparin treatment for overall VTE rates. Comparisons were also made to injured patients without a BCVI in our Trauma Activation Protocol (TAP) database. ResultsDuring the 5-year study period, 265 patients were identified with a BCVI. The majority (61%) were men with a median injury severity score (ISS) 22 (interquartile range [IQR]:14-33). Of these patients, 146 (55.1%) received a heparin infusion to treat BCVI. VTE was identified in eight of these patients (5.5%). Compared to TAP patients (n = 1020) who received standard dosing of VTE chemoprophylaxis, there was no difference in VTE rates compared to BCVI patients who were started on a low dose heparin infusion (3% versus 5.5%, P = 0.16). Area under the receiver operating characteristics (AUROC) was used to evaluate the predictive power of time to initiation of heparin infusion (AUC = 0.64 95% CI 0.42-0.85, P = 0.2) and time to reaching PTT goal (AUC = 0.52 95% CI 0.27-0.77, P = 0.83) as a predictor VTE events. ConclusionsLow dose heparin infusion is frequently used as an initial treatment of BCVI. In injured patients with BCVI, a low dose heparin infusion is associated with a low rate of VTE, comparable to injured patients without BCVI that received standard VTE chemoprophylaxis.

Are IBD Patients Underscored when Determining Postoperative VTE Risk?

BackgroundPatients with inflammatory bowel disease (IBD) have an increased risk of venous thromboembolism (VTE) following colorectal surgery and there is currently no consensus on post-surgical VTE prevention or specific VTE risk assessment tools. We sought to evaluate VTE risk after colorectal surgery and determine if known risk factors used in risk assessment tools adequate correlate with VTE risk in IBD patients. MethodsRetrospective cohort study using the National Surgical Quality Improvement Project (NSQIP) Participant User File from 2010 to 2018. ResultsA total of 27,679 patients were included; 19,015 (68.7%) had Crohn’s disease (CD) and 8664 (31.3%) ulcerative colitis (UC). Of these, 16,749 (60.5%) underwent abdominopelvic procedures, 10,178 (36.8%) complex pelvic procedures, and 752 (2.7%) small bowel operations. The overall VTE rate was 2.3%. The VTE rate in patients with CD and UC was 1.8% and 3.6% (p < 0.001) respectively. Overall median time to VTE was 9 days after surgery. VTE rate was highest in patients who underwent complex pelvic procedures (3.6%; 361/10,178). A risk score was calculated using 16/40 available variables from the Caprini VTE Risk Assessment tool; risk score ranged from 3 to 12 points. Most patients that developed a VTE had a score between 3 and 5 points (75.6%), and only 24.5% had a score of 6 or higher. Patients with higher risk scores did not have a higher VTE incidence. ConclusionPost-surgical VTE rates are high in IBD patients. Over half of the events occurred following discharge and in patients with an apparent low-risk score. Additional studies are warranted to define a recommended postoperative VTE prophylaxis regimen for patients with IBD.

Hip Replacement Surgery and Anticoagulation; A Mortality, Transfusion Need and Venous Thromboembolism Rate Analysis with Trinetx

Introduction: Hip replacement surgery is usually performed in elderly patients and may lead to complications such as major bleeding and venous thromboembolism (VTE). Also, there is a higher proportion of anticoagulated patients within the elderly. Classically, vitamin K antagonists (VKA) have been associated with higher risk of bleeding and with other perioperative and post-operative complications. The aim of this study is to analyse and compare the mortality, the blood transfusion needs and the VTE rate in patients anticoagulated with VKA and in patients treated with direct oral anticoagulants (DOACs) who went through hip replacement surgery. Methods: TriNetX is the global federated health research network providing access to electronic medical records across large healthcare organizations (HCO), with a database of more than 80 million patients. This report was run on the set of HCOs grouped into a network called Global - Anonymous. This network included 113 HCOs. This analysis compared the outcomes of two cohorts; Cohort A: hip replacement + DOACs, and Cohort B: hip replacement + VKA, in the last 2 years. Propensity score matching was performed in both cohorts, so the main difference between them was the type of anticoagulant therapy. Demographic and comorbidities data, 90-days mortality, blood transfusion need and thrombotic events until 90 days after discharge were analysed. Results: A total of 8,270 patients were included in cohort A and 11,750 in cohort B. After propensity score matching was performed, both cohorts included 7,940 patients. The main characteristics are shown in table 1, no significant differences were found. There were more deaths in the cohort B than in the cohort A, specifically in cohort B there were 950 deaths while in cohort B there were 780 (HR 1.11, CI95% 1.008, 1.221, p= 0.001). The patients who received DOACs as anticoagulant treatment showed a significantly lower need of blood transfusion than patients treated with VKA; 970 patients needed transfusion in cohort A while 1,210 had need of transfusion in cohort B (OR: 0.77 95%CI: 0.7-0.84). Regarding VTE, there were no significant differences between both cohorts. 1,640 patients suffered thromboembolic events in cohort A while in cohort B there were 1,580 (OR: 1.05 95%CI: 0.97-1.13). Conclusions: According to the results of this study, in the context of hip replacement surgery, anticoagulation with DOACs is associated with a lower 90-days mortality and with a lower need of blood transfusion, with no difference in the VTE rate in the post-operative. So, it is of great importance to individualize the thrombotic risk and the haemorrhagic risk before the hip replacement surgery in order to do a correct management of the anticoagulation, including the bridging therapy especially in those patients anticoagulated with VKA, in order to prevent perioperative complications. DOACs are a safer option than VKA as an anticoagulant treatment, especially in the elderly, who might need more surgical treatments. The use of DOACs as anticoagulant treatment should be extended as their security profile is safer than VKA, since they associate a lower mortality and can prevent blood transfusions.

Does Synchronous Liver Intervention Increase Risk of Venous Thromboembolism in Patients with Metastatic Small-Bowel and Pancreatic Neuroendocrine Tumors?

INTRODUCTION: Previous literature suggests a higher incidence of venous thromboembolism (VTE) in patients with pancreatic neuroendocrine tumor (PNET) but no other gastrointestinal NET. In this study, we analyze the incidence of VTE in patients with metastatic small-bowel neuroendocrine tumors (SBNETs) and PNET undergoing synchronous liver procedures to determine whether these patients require extended VTE prophylaxis. METHODS: The American College of Surgeons NSQIP database was queried from 2008 to 2019 for patients undergoing operation for SBNET, PNET, benign small bowel, and pancreatic pathology. Patients with SBNET and PNET were stratified by additional operative procedures for liver metastasis (LM). The rate of 30-day postoperative VTE (pulmonary embolism [PE] and/or deep vein thrombosis [DVT]) was compared. Pearson’s chi-square and ANOVA tests were used for analysis. RESULTS: A total of 89,054 patients met inclusion criteria (63,396 benign small bowel, 3,073 SBNET, including 918 with LM, 18,724 benign pancreas, 3,861 PNET including 949 with LM). There was no statistically significant difference in the rate of VTE in patients with small-bowel disease with or without LM. Patients in the PNET with LM group had a significantly higher rate of PE but not DVT than those undergoing pancreatic operation for benign pathology (2.4% vs 1.1%; p < 0.001). Total operation time (odds ratio [OR] 1.002; p = 0.002), length of hospital stay (OR 1.027; p < 0.001), and preoperative dialysis (OR 3.779; p = 0.004) were independently associated with VTE. However, synchronous liver intervention was not an independent factor associated with VTE or PE in patients with PNET (Table 1). Table 1. - Rates of DVT and PE in Patients with PNETs and SBNETs Undergoing Synchronous Liver Procedures Group Total Rate of DVT Rate of PE Benign small-bowel procedures 63,396 987 (1.6%) 398 (0.6%) Procedures for SBNETs 2,155 26 (1.2%) 11 (0.5%) SBNETs with synchronous liver procedures 918 12 (1.3%) 9 (1.0%) Benign pancreas procedures 18,724 400 (2.1%) 203 (1.1%) Procedures for PNETs 2,912 59 (2.0%) 44 (1.5%) PNETs with synchronous liver procedures 949 18 (1.9%) 23 (2.4%) CONCLUSION: Synchronous liver intervention does not increase the risk of VTE in patients with metastatic SBNET or PNET.

Assessment of BMI and Venous Thromboembolism Rates in Patients on Standard Chemoprophylaxis Regimens After Undergoing Free Tissue Transfer to the Head and Neck

Venous thromboembolism (VTE) is a severe complication after free tissue transfer to the head and neck (H&N). Enoxaparin 30 mg twice daily (BID) is a common regimen for chemoprophylaxis. However, differences in enoxaparin metabolism based on body weight may influence its efficacy and safety profile. To assess the association between BMI and postoperative VTE and hematoma rates in patients treated with prophylactic enoxaparin 30 mg BID. This was a retrospective review of a prospectively collected cohort from 2012 to 2022. Postoperative VTE, hematoma, and free flap pedicle thrombosis were recorded within 30 days of index surgery. The setting was a tertiary academic referral center. Participants included patients undergoing H&N reconstruction with free flaps that received fixed-dose subcutaneous enoxaparin 30 mg BID postoperatively. Statistical analysis was conducted from April to May 2022. Outcomes include incidence of VTE, hematoma, and flap pedicle thrombosis events within 30 days of the surgery. Univariate and multivariable regression models were used to evaluate associations between BMI and other patient factors with these outcomes. Among the 765 patients included, 262 (34.24%) were female; mean (SD) age was 60.85 (12.64) years; and mean (SD) BMI was 26.36 (6.29). The rates of VTE and hematoma in the cohort were 3.92% (30 patients) and 5.09% (39 patients), respectively. After adjusting for patient factors, BMI was the only factor associated with VTE (OR, 1.07; 95% CI, 1.015-1.129). Obesity (BMI >30) was associated with increased odds of VTE (OR, 2.782; 95% CI, 1.197-6.564). Hematoma was not associated with BMI (OR, 0.988; 95% CI, 0.937-1.041). Caprini score of at least 9 was not associated with VTE (OR, 1.259; 95% CI, 0.428-3.701). This cohort study found that obesity was associated with an increased risk of VTE in patients after microvascular H&N reconstruction and while on standard postoperative chemoprophylaxis regimens. This association may suggest insufficient VTE prophylaxis in this group and a potential indication for weight-based dosing.

Venous Thromboembolism in Foot and Ankle Surgery: How Common is It?

Category: Other; Ankle; Ankle Arthritis; Bunion; Sports Introduction/Purpose: Venous thromboembolism (VTE) is a feared complication following orthopaedic surgery. The limited research exploring the rate of VTE following different types of foot and ankle surgery makes it difficult to establish clear guidelines for prescribing VTE prophylaxis. Therefore, the purpose of this study was to determine the rate of VTE in patients undergoing various types of foot and ankle procedures. Methods: A large online retrospective database that utilizes ICD and CTP codes was queried to determine the rate of VTE that occurred within 1-month of surgery in common foot and ankle procedures. Surgeries investigated included: Arthrodesis, Total Ankle Arthroplasty, Bunionectomy, Hammer Toe Correction, Watson-Jones, and Achilles repair. Only patients that did not receive postoperative anticoagulation or antiplatelet agents were included in the analysis. Demographic data was also collected. Results: From 2011 to 2022, 27,872 patients underwent Arthrodesis, 1,513 had a Total Ankle Arthroplasty, 31,808 had a Bunionectomy, 26,828 had Hammer Toe correction, 7,545 had a Watson-Jones procedure, and 8,770 had an Achilles repair. Of these procedures, Achilles repair had the highest rate of postoperative VTE (1.32%), followed by Watson-Jones (1.21%), Arthrodesis (0.89%), Ankle Arthroplasty (0.86%), Hammer Toe (0.76%) and Bunionectomy (0.65%). The overall rate of VTE in all procedures was found to be 0.84% (880/104,336). Conclusion: Venous thromboembolism is a serious complication following foot and ankle surgery. The unknown incidence of VTE in common foot and ankle surgeries may contribute to the lack of clear guidelines for prescribing VTE prophylaxis. This study helps to define rates of VTE in patients not receiving prophylaxis that underwent Arthrodesis, Ankle Arthroplasty, Bunionectomy, Hammer Toe, Watson-Jones, and Achilles repair. More studies are needed to help establish clear guidelines for foot and ankle surgeons to follow.

Correlation of Statins Use with the Incidence of Venous Thromboembolism in Patients with Ankle Fracture

Category: Ankle; Other Introduction/Purpose: Finding factors that can exacerbate or ameliorate the incidence of Venous thromboembolism (VTE) can affect the process of making decision on whether to start prophylaxis or not, especially when on the verge of whether to-give or not-to-give prophylaxis. Among each patient's profile, medications are of the most important factors influencing surgeon's decision on the prophylactic methods in VTE-vulnerable patients. Among medications, Statins were shown to reduce the incidence of VTE in patients who were receiving them for hyperlipidemia and cardiovascular conditions. However, none of the current VTE prediction methods, particularly in orthopaedic practice, have considered statins protective. Herein we aimed to determine any correlations between statin consumption and the incidence of VTE in ankle fractures and whether to include statins in prediction models of VTE. Methods: In this case-control machine learning-based study, approved by the Institutional Review Board (IRB), the ICD and CPT codes were used to identify the patients who were diagnosed with ankle fracture in the Mass General Brigham database from 2004 to end of May 2021. After screening approximately 16,421 patients with ankle fractures, a total of 1,176 patients who were suspect VTE according to their signs and symptoms were recruited, 239 had confirmed VTE (case group) and 937 did not have VTE (controls). Forty-nine cases and 396 controls were statin users. Using a semi-automated machine learning-based algorithm, patients' demographics, past medical and surgical history, fracture characteristics and weber classification, and statin consumption status were obtained, and values were organized in a numerical analyzable manner in the dataset. We used chi-squared and Pearson correlation tests where applicable, and outcomes were displayed and interpreted using p-value (p&lt;0.05 considered significant) and odds ratio (OR). Results: The mean age and BMI in our case group were 55.1+-17.0 y/o and 30.0+-6.0, respectively; age and BMI in the controls were 69.4+-13.2 (p=0.09 vs. cases) and 29.2+-6.6 (p=0.12 vs. cases), respectively. Gender distribution is depicted in table 1. In addition, we found that in our population, a total of 239 patients had VTE, from which 49 (21%) were taking Statins and 190 (79%) were not. Out of the 937 patients who did not develop VTE, 396 (42%) were taking Statins whereas 541 (58%) were not. We found that patients taking statins had lower incidence of VTE after their ankle fracture, compared with patients not taking statins (OR=0.36, p &lt;0.001). The distribution of statin users/non-users among cases and controls is shown in table 2. Moreover, using our machine learning algorithm, conditions that would necessitate the use of statins including cardiovascular diseases and hyperlipidemia showed negative significant correlation with VTE (p&lt;=0.02). Conclusion: Several studies have suggested that hyperlipidemic blood is prone to a greater generation of thrombin, endothelial dysfunction, and higher platelet activity. By disturbing these mechanisms, statins play a protective role against VTE. Herein, using machine learning algorithms together with statistical analysis, we found that Statins were significantly associated with a lower rate of VTE in patients with an ankle fracture. These findings can be considered in future prediction models that are built based on patient-specific factors. Knowing the protective effect of statins can also help clinicians with deciding on prophylaxis administration in at VTE-risk patients.fig

P144. The effect of operative duration on postoperative VTE rates in spinal surgery

<h3>BACKGROUND CONTEXT</h3> The relationship between operative duration and its effect on postoperative venous thromboembolism (VTE) remains unclear in spine surgery. Previous studies have been limited in cohort size or have lacked adequate variability of surgical duration to determine the extent of effect surgery length has on VTE rates. Information regarding patient demographics and the effect of surgical durations on VTE are critical to establish appropriate guidelines for determining which patients could benefit from postoperative chemoprophylaxis. <h3>PURPOSE</h3> To determine the effect of operative duration on postoperative VTE rates in patients undergoing elective thoracolumbar spinal procedures. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort study. <h3>PATIENT SAMPLE</h3> Patients >18 years of age who underwent thoracolumbar spinal fusion between 2007-2021 were retrospectively identified. A 10:1 propensity match incorporating patient demographics and surgical characteristics was conducted to match and compare patients for postoperative VTE events. <h3>OUTCOME MEASURES</h3> Postoperative VTE events, cut-to-close duration, prior history of clots, Oswestry Disability Index (ODI), Mental (MCS-12) and Physical (PCS-12) Component Summary of the Short-Form 12, visual analog scale (VAS) Back, VAS Leg. <h3>METHODS</h3> A structured query language (SQL) search was used to identify patients who underwent a thoracolumbar surgery and had a postoperative VTE. Only patients with deep VTEs were included. Demographics, surgical characteristics and patient reported outcome measures (PROMs) were collected from the electronic medical record. Patients were categorized into a VTE and non-VTE group. Categorical comparisons were analyzed using Pearson chi-square analysis or Fisher's Exact test. Continuous variables were analyzed using independent samples t-test or Mann-Whitney U test. A binary logistic regression was then performed to determine if cut-to-close duration was a predictor of increased postoperative VTE events—controlling for demographics and a history of clots. A receiver operating characteristic (ROC) curve using Youden's index was created to determine a "cutoff" time for predicting increased likelihood of a VTE based on surgical duration. <h3>RESULTS</h3> A total of 1,456 patients (122 VTE, 1,334 non-VTE) were included. The VTE group was younger (61.5 vs 65.5, p<0.001), predominantly male (60.8% vs 44.5%, p=0.001), experienced a previous VTE (15.6% vs 2.92%, p<0.001) and had higher cut-to-close time (304 mins vs 209 mins, p<0.001). However, there was no difference in CCI between groups (1.08 vs 0.66, p=0.119). When evaluating PROMs, the VTE group had worse 1-year postoperative minus preoperative (∆) ODI (-11.79 vs -21.99, p=0.039), ∆PCS-12 (4.30 vs 8.52, p=0.045), and ∆VAS Leg (-1.41 vs -4.08, p=0.001). Operative duration was an independent predictor of increased postoperative VTE rates on bivariate regression analysis (β=0.01, p<0.001). When evaluating the ROC, a cutoff time of 245 mins was identified (AUC [95% CI] = 0.672 [0.615 – 0.728]) as an optimal predictor of increased risk for a VTE. <h3>CONCLUSIONS</h3> A history of a prior VTE was associated with greater VTE rates during elective thoracolumbar surgery. Patients with a VTE had worse 1-year ∆ODI, ∆PCS-12, and ∆VAS Leg indicating that patients have worse overall improvement after VTE development, even after the VTE has been treated. Additionally, a higher operative duration is an independent risk factor for postoperative VTE. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Rivaroxaban and Risk of Venous Thromboembolism in Patients With Symptomatic Peripheral Artery Disease After Lower Extremity Revascularization

Prior studies have observed an association between the burden of atherosclerotic vascular disease and the risk of venous thromboembolism (VTE). The association is not well described in peripheral artery disease (PAD) after lower extremity revascularization (LER). To describe the risk of, factors associated with, and outcomes after VTE, as well as the association of low-dose rivaroxaban plus antiplatelet therapy with VTE after LER. This global, multicenter cohort study used data from the Vascular Outcomes Study of ASA (acetylsalicylic acid) Along With Rivaroxaban in Endovascular or Surgical Limb Revascularization for PAD (VOYAGER PAD) randomized clinical trial, which enrolled patients from 2015 to 2018 with median follow-up of 28 months. Participants included patients with PAD undergoing LER. Patients with an indication for therapeutic anticoagulation were excluded. Data were analyzed from September 2020 to September 2021. Randomization to rivaroxaban 2.5 mg twice daily or placebo on a background of aspirin 100 mg daily; short-term clopidogrel was used at the discretion of the treating physician. Symptomatic VTE was a prespecified secondary outcome and prospectively collected. Among 6564 patients (median [IQR] age, 67 [61-73] years; 4860 [74.0%] men), 66 patients had at least 1 VTE. The 3-year rate of VTE in patients receiving placebo was 1.7%, and the pattern of risk was linear (year 1: 0.5%; year 2: 1.1%). After multivariable modeling, weight (hazard ratio [HR], 3.04; 95% CI, 1.09-8.43), hypertension (HR, 2.11; 95% CI, 0.91-4.89), prior amputation (HR, 2.07; 95% CI, 0.95-4.53), and older age (HR, 1.81; 95% CI, 1.06-3.11) were associated with increased risk of VTE. VTE was associated with risk of subsequent mortality (HR, 7.22; 95% CI, 4.66-11.19). Compared with aspirin alone, rivaroxaban plus aspirin was associated with lower VTE risk (HR, 0.61; 95% CI, 0.37-0.998; P = .047), with benefit apparent early and sustained over time. This association was not modified by use of clopidogrel at randomization (without clopidogrel: HR, 0.55; 95% CI, 0.29-1.07; with clopidogrel: HR, 0.69; 95% CI, 0.32-1.48; P for interaction = .67). In this cohort study, there was continuous risk for VTE after LER in patients with PAD, with greater risk in patients who were older and had obesity and those with more severe PAD, as reflected by prior amputation. Low-dose rivaroxaban plus aspirin was associated with lower VTE risk compared with aspirin alone, with benefits apparent early and continued over time. The spectrum of venous and arterial thrombotic events and overall benefits of more potent antithrombotic strategies for prevention should be considered after LER for PAD.

Venous thromboembolism in pediatric patients with acute lymphoblastic leukemia under chemotherapy treatment. Risk factors and usefulness of thromboprophylaxis. Results of LAL‐SEHOP‐PETHEMA‐2013

IntroductionSymptomatic venous thromboembolism (VTE) is diagnosed in 3%–14% of patients during pediatric acute lymphoblastic leukemia (ALL) therapy. There are well‐known risk factors, but the role of others as inherited thrombophilia is still controversial. Prophylaxis with low molecular weight heparin (LMWH) has been described, but its use is not globally accepted. MethodsA retrospective multicentric study in ALL patients 1–18 years old following SEHOP‐PETHEMA‐2013 treatment guideline was performed to evaluate VTE rate, anticoagulant treatment, outcome, risk factors, and safety and usefulness of LMWH administration as primary thromboprophylaxis in children with inherited thrombophilia. ResultsA total of 652 patients were included in the study. VTE incidence was 8.7%. Most of the cases occurred during induction therapy associated with central venous catheter. Univariant analysis showed that family history of thrombosis, presence of mediastinal mass, high‐risk treatment group, and inherited thrombophilia were statistically significant risk factors. LMWH administration seemed to decrease VTE rate in patients with inherited thrombophilia and those with T‐cell ALL phenotype. ConclusionMost of the VTE cases occurred in patients without inherited thrombophilia, but when it is present, the VTE risk is higher. LMWH administration was useful to decrease VTE in these patients.

The association of timing of pharmacological prophylaxis and venous thromboembolism in patients with moderate-to-severe traumatic brain injury: A retrospective cohort study.

OBJECTIVES:Patients with traumatic brain injury (TBI) have an increased risk for venous thromboembolism (VTE). The current guidelines recommend pharmacologic prophylaxis, but its timing remains unclear.METHODS:In this retrospective cohort study, patients with moderate-to-severe TBI admitted to a tertiary care intensive care unit between 2016 and 2019 were categorized into two groups according to the timing of pharmacologic prophylaxis: early if prophylaxis was given within 72 h from hospital admission and late if after 72 h.RESULTS:Of the 322 patients in the cohort, 46 (14.3%) did not receive pharmacological prophylaxis, mainly due to early brain death; 152 (47.2%) received early pharmacologic prophylaxis and 124 (38.5%) received late prophylaxis. Predictors of late pharmacologic prophylaxis were lower body mass index, intracerebral hemorrhage (odds ratio [OR], 3.361; 95% confidence interval [CI], 1.269–8.904), hemorrhagic contusion (OR, 3.469; 95% CI, 1.039–11.576), and lower platelet count. VTE was diagnosed in 43 patients on a median of 10 days after trauma (Q1, Q3: 5, 15): 6.6% of the early prophylaxis group and 26.6% of the late group (P < 0.001). On multivariable logistic regression analysis, the predictors of VTE were Acute Physiology and Chronic Health Evaluation II score, subarachnoid hemorrhage, and late versus early pharmacologic prophylaxis (OR, 3.858; 95% CI, 1.687–8.825). The late prophylaxis group had higher rate of tracheostomy, longer duration of mechanical ventilation and stay in the hospital, lower discharge Glasgow coma scale, but similar survival, compared with the early group.CONCLUSIONS:Late prophylaxis (>72 h) was associated with higher VTE rate in patients with moderate-to-severe TBI, but not with higher mortality.

Venous Thromboembolism Rate in Patients With Bladder Cancer According to the Type of Treatment: A Systematic Review.

Bladder cancer (BC) is classified as a high-risk tumour type for venous thromboembolism (VTE). VTE presents an extra challenge in the management of patients with cancer, given the increase in morbidity and mortality on having both conditions.To summarise the contemporary evidence on the VTE rate in patients with BC according to the stage, type of anti-cancer treatment and highlight VTE rate in the UK and other countries. A systematic review was carried out, and an electronic search for publications between January 2000 and November 2021 was done. Studies recording VTE in BC patients were included, whilst paediatric patients, case reports, studies reporting on a mix of arterial and venous thrombosis, studies reporting DVT or PE only and recorded hospitalised VTE only were excluded. The rate of VTE, country of origin, risk factors and thromboprophylaxis duration for VTE in BC patients were identified.A total of 38 papers met the search criteria. All publications were original research papers (cohort studies). The overall VTE rate in patients with BC was estimated at 1.9% to 4.7%. For those patients undergoing cystectomy, the VTE rate ranged from 3% to 17.6%; however, the VTE rate in the metastatic stage of BC patients ranged from 3.1% to 5.1%.The rates of VTE in BC patients are high, further increased by interventions such as surgery and chemotherapy. Thromboprophylaxis measures should be optimised. This review highlighted the fact that the VTE rate in BC varies between studies due to the heterogeneity of risk factors reported.

Multidisciplinary Bundle Approach in Venous Thromboembolism Prophylaxis in Patients with Non-Traumatic Subarachnoid Hemorrhage

BackgroundA venous thromboembolism (VTE) bundle was launched in 2016 at the University of Illinois Hospital aiming to reduce the rate of VTE in the neurosurgical ICU. Main elements of the bundle included correct and early use of intermittent pneumatic compression and subcutaneous heparin.MethodsPatients with SAH were retrospectively identified from 2014 until 2018. VTE events were diagnosed using twice weekly lower-extremity venous Duplex ultrasound and chest computerized tomography when appropriate.ResultsA total of 133 patients was included in each group. The incidence of VTE was not significantly different before and after the bundle (15% vs. 12%, p = 0.47). No difference was found regarding new episode of intracranial hemorrhage secondary to SQH (1.5% vs. 2.1%, p = 0.65). Multivariate analysis demonstrated that longer ICU LOS, higher Caprini score, and presence of baseline lung diseases were associated with VTE development.ConclusionsWith a median Caprini score of 9, our patient population was found to be at high risk for developing VTE. The implementation of the VTE bundle did not significantly reduce the rate of VTE in patients with non-traumatic SAH at UIH.

Extended thromboprophylaxis post gynaecological cancer surgery; the effect of weight adjusted and fixed dose LMWH (Tinzaparin)

ObjectiveGynaecological cancer surgery is associated with high rates of venous thromboembolism (VTE) despite recommended prophylaxis. We sought to investigate the impact of extended prophylaxis with fixed dose and weight based LMWH in patients undergoing gynaecological cancer surgery. MethodsVTE rates were recorded in patients who received LMWH prophylaxis (4500 IU Tinzaparin once daily) for the duration of hospital stay (2006–2012) (n = 610) and were compared with VTE rates in patients who underwent surgery after the introduction of extended prophylaxis (3500/4500 IU Tinzaparin for patients with BMI < 40kg/m2 and 75 IU/kg for BMI > 40 kg/m2) (2012–2017) (n = 651). Peak (4 h) anti-Xa levels in a subset of patients were also evaluated. Results73 (5.7%) cases of VTE were recorded during 1 year of follow-up. 20 cases occurred during hospital stay. There was no significant difference in the rate of VTE between the extended prophylaxis cohort and the standard prophylaxis cohort. 23/24 patients who developed VTE in the extended prophylaxis cohort received a fixed (4500 units) dose of Tinzaparin. 63% of patients who received a fixed LMWH dose had peak anti-Xa levels below the target range (0.2–0.4 IU/ml). Peak anti-Xa was lower in patients who subsequently developed VTE compared with those who received either fixed dose (P = 0.041) and weight adjusted Tinzaparin (P = 0.0006). ConclusionsExtended prophylaxis with Tinzaparin does not significantly reduce VTE rates in gynaecological cancer patients post surgery. Peak anti-Xa levels may be suboptimal in many patients receiving a fixed LMWH dose. Further studies are required to determine whether weight adjusted doses of Tinzaparin may provide more effective prophylaxis following gynaecological cancer surgery.