Risk Factors For Venous Thromboembolism Research Articles

Case Report: Branch retinal vein occlusion following COVID-19 vaccination and SARS-CoV-2 infection while taking oral contraceptives

Oral contraceptive use, vaccination for Coronavirus disease 2019 (COVID-19), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are risk factors for venous thromboembolism. Branch retinal vein occlusion (BRVO) generally develops mid-60s patients. Herein, we present a case of BRVO caused by the above mentioned risk factors in a young woman. To the best of our knowledge, this is the first report about BRVO associated with oral contraceptives, COVID-19 vaccination, and SARS-CoV-2. A 21-year-old woman presented with loss of visual acuity in her right eye for 10 days. She had been receiving oral contraceptives for 2 years for oligomenorrhea before noticing ophthalmological symptoms. Despite having received two doses of an mRNA COVID-19 vaccine, she contracted COVID-19 and developed fever, sore throat, cough, low back pain, and general malaise about 40 days before the initial visit. However, only cough persisted for more than a month. The right eye showed BRVO with macular edema (ME). She did not smoke nor had diabetes or hypertension. Blood test results, including cardiolipin antibody IgG, were normal. She was treated with an intravitreal aflibercept injection. ME in the fundus showed rapid improvement and resolution. Although more than 20 months have passed since the first injection, there has been no relapse of ME. The combination of oral contraceptive use, COVID-19 vaccination, and subsequent SARS-CoV-2 infection could induce the development of venous thromboembolism, thereby leading to BRVO. Given that cases of COVID-19 have increased globally, patients with retinal vein occlusion who use oral contraceptives are likely to be encountered more frequently.

Non-Invasive Ventilation Support during Hospitalization for SARS-CoV-2 and the Risk of Venous Thromboembolism

Background/Objectives: Although SARS-CoV-2 infection is a significant risk factor for venous thromboembolism (VTE), data on the impact of the use of non-invasive ventilation support (NIVS) to mitigate the risk of VTE during hospitalization are scarce. Methods: Data for 1471 SARS-CoV-2 patients, hospitalized in a single hub during the first pandemic wave, were collected from clinical records, including symptom duration and type, information on lung abnormalities on chest computed tomography (CT), laboratory parameters and the use of NIVS. Determining VTE occurrence during hospital stays was the main endpoint. Results: Patients with VTE (1.8%) had an increased prevalence of obesity (26% vs. 11%), diabetes (41% vs. 21%), higher CHA2DS2VASC score (4, IQR 2–5 vs. 3, IQR 1–4, age- and sex-adjusted, p = 0.021) and cough (65% vs. 44%) and experienced significantly higher rates of NIVS (44% vs. 8%). Using a stepwise multivariate logistic regression model, the prevalence of electrocardiogram abnormalities (odds ratio (OR) 2.722, 95% confidence interval (CI) 1.039–7.133, p = 0.042), cough (OR 3.019, 95% CI 1.265–7.202, p = 0.013), CHA2DS2-VASC score > 3 (OR 3.404, 95% CI 1.362–8.513, p = 0.009) and the use of NIVS (OR 15.530, 95% CI 6.244–38.627, p < 0.001) were independently associated with a risk of VTE during hospitalization. NIVS remained an independent risk factor for VTE even after adjustment for the period of admission within the pandemic wave. Conclusions: Our study suggests that NIVS is a risk factor for VTE during hospitalization in SARS-CoV-2 patients. Future studies should assess the optimal prophylactic strategy against VTE in patients with a SARS-CoV-2 infection candidate to non-invasive ventilatory support.

Updated review on malignancy-associated venous thromboembolism: Pathogenesis and comparison between various therapeutic modalities

Venous thromboembolism (VTE) is one of the life-threatening complications in cancer patients, the incidence of which is affected by the patient and malignancy-related variables. Location, type, therapeutic route, stage, grade, and non-supportive treatment of the cancer are the most important VTE risk factors. Patient age, ethnicity, and concomitant genetic or acquired comorbidities or thrombophilias are known risk factors for VTE in cancer. All high-risk cancer patients admitted to hospitals or treated as outpatients should receive VTE prophylaxis. Low molecular weight heparin is the main treatment for active malignant VTE. Vitamin K antagonists and non-Vitamin K-dependent oral anticoagulants are used in stable, non-bleeding cancer patients. Anticoagulation should be continued until the cancer is treated or at least controlled. Over the past two decades, randomized clinical and observational trials have improved the pathogenesis and therapeutic knowledge of VTE, but many challenges remain. The lack of an optimal primary prophylaxis method for inpatients and outpatients in oncology and the care of cancer-associated VTE in standard and high-bleeding risk groups are examples for which more clinical research on cancer-associated thrombosis is necessary to address these issues. In this review, we describe the pathogenesis, factors that increase the risk of VTE, and the comparison between the effectiveness of available anticoagulants in the treatment and prevention of VTE in cancer patients.

Evaluation of a Risk Screening Checklist for Venous Thromboembolism Prophylaxis in a Women and Newborn Hospital

ABSTRACT Introduction The venous thromboembolism (VTE) risk screening forms were developed to allow for recording identified risk factors for VTE including thrombophilia, history of VTE, postpartum hemorrhage, and cesarean delivery, and documentation of specific actions taken to mitigate these risks and reduce complications due to VTE. Methods Compliance with hospital guidelines in assessing VTE risk and appropriate prescribing of thromboprophylaxis was evaluated prior to the introduction of VTE risk screening forms (March 2022). Efficacy of the new VTE risk screening forms was also assessed (April 2023). Patient discharge summaries and patient medical records including medication charts were used to review the documentation of VTE risk assessments and details of thromboprophylaxis prescribing. Results Of 74 postnatal patients, 37.8% had VTE risk assessment documented prior to the introduction of VTE risk screening forms. Of 37 patients identified to be at moderate to high risk of VTE requiring pharmacological prophylaxis, 70.3% (n = 26) were appropriately prescribed pharmacological prophylaxis. After the risk screening forms were introduced, a total of 67 antenatal, postnatal, and gynecologic patients were studied. Of these, 32.8% (n = 22) of patients had all required fields completed appropriately. When using the forms, 26.9% (n = 7) of postnatal and 88% (n = 22) of gynecological patients were rated as medium or high risk, and all received medical review within 24 hours. Pharmacological prophylaxis was indicated in 88% (n = 22) of gynecological, 43.8% (n = 7) of antenatal, and 38.5% (n = 10) of postnatal patients, and all were appropriately prescribed. Conclusion The guideline review and introduction of VTE risk screening forms was valuable to provide guidance in the risk assessment for VTE and to identify patients requiring prophylaxis.

Two-sample Mendelian randomization analysis reveals causal relationships between blood lipids and venous thromboembolism.

Venous Thromboembolism (VTE) is a complex disease that can be classified into two subtypes: Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE). Previous observational studies have shown associations between lipids and VTE, but causality remains unclear. Hence, by utilizing 241 lipid-related traits as exposures and data from the FinnGen consortium on VTE, DVT, and PE as outcomes, we conducted two-sample Mendelian randomization (MR) analysis to investigate causal relationships between lipids and VTE, DVT and PE. The MR results identified that fatty acid (FA) unsaturation traits (Ratio of bis-allylic bonds to double bonds in lipids, and Ratio of bis-allylic bonds to total fatty acids in lipids) were associated with VTE (OR [95% CI]: 1.21 [1.15-1.27]; 1.21 [1.13-1.30]), DVT (OR [95%CI]: 1.24 [1.16-1.33]; 1.26 [1.16-1.36]) and PE (OR [95%CI]: 1.18 [1.08-1.29]; 1.18 [1.09-1.27]). Phosphatidylcholines exhibit potential causal effects on VTE and PE. Phosphatidylcholine acyl-alkyl C40:4 (PC ae C40:4) was negatively associated with VTE (OR [95% CI]: 0.79 [0.73-0.86]), while phosphatidylcholine diacyl C42:6 (PC aa C42:6) and phosphatidylcholine acyl-alkyl C36:4 (PC ae C36:4) were positively associated with PE (OR [95%CI]: 1.44 [1.20-1.72]; 1.22 [1.10-1.35]). Additionally, we found that medium LDL had a protective effect on VTE. Our study indicates that higher FA unsaturation may increase the risk of VTE, DVT, and PE. Different types of phosphatidylcholine have either promotive or inhibitory effects on VTE and PE, contributing to a better understanding of the risk factors for VTE.

A nomogram to predict the risk of venous thromboembolism in patients with colon cancer in China.

To create a nomogram for predicting the likelihood of venous thromboembolism (VTE) in colon cancer patients from China. The data of colon cancer patients from Chongqing University Cancer Hospital between 2019 and 2022 were analyzed. Patients were divided into training set and internal validation set by random split-sample method in a split ratio of 7:3. The univariable and multivariable logistic analysis gradually identified the independent risk factors for VTE. A nomogram was created using all the variables that had a significance level of p < 0.05 in the multivariable logistic analysis and those with clinical significance. Calibration curves and clinical decision curve analysis (DCA) were used to assess model's fitting performance and clinical value. Harrell's C-index (concordance statistic) and the area under the receiver operating characteristic curves (AUC) were used to evaluate the predictive effectiveness of models. A total of 1996 patients were ultimately included. There were 1398 patients in the training set and 598 patients in the internal validation set. The nomogram included age, chemotherapy, targeted therapy, hypertension, activated partial thromboplastin time, prothrombin time, platelet, absolute lymphocyte count, and D-dimer. The C-index of nomogram and Khorana score were 0.754 (95% CI 0.711-0.798), 0.520 (95% CI 0.477-0.563) in the training cohort and 0.713 (95% CI 0.643-0.784), 0.542 (95% CI 0.473-0.612) in the internal validation cohort. We have established and validated a nomogram to predict the VTE risk of colon cancer patients in China, which encompasses a diverse age range, a significant population size, and various clinical factors. It facilitates the identification of high-risk groups and may enable the implementation of targeted preventive measures.

Thrombin generation profile using ST-Genesia after PEG-asparaginase in pediatric patients with acute lymphoblastic leukemia.

Venous thromboembolism (VTE) etiology in children with acute lymphoblastic leukemia (ALL) is multifactorial. The use of global assays of hemostasis as thrombin generation test (TGT) is useful to individualize VTE risk in adult patients. The aim of this prospective cohort study was to evaluate the usefulness of an automated TGT to evaluate VTE risk during ALL treatment in children. TGT (automated analyzer ST Genesia; ThromboScreen) and pro and anticoagulant plasma proteins were analyzed during ALL treatment in pediatric patients following LAL-SEHOP-PETHEMA-2013 guidelines. Results were compared with a series of pediatric normal controls and evaluated according to pegylated asparaginase PEG-ASP administration and to VTE risk factors. The study included 67 patients: males n=35, B-ALL (n=60). None had a VTE during the evaluated period. Compared to healthy controls, normalized endogenous thrombin potential (N-ETP) ratio in patients was higher and ETP inhibition (ETP-inh) was lower, especially after PEG-ASP administration. Plasmatic protein C and protein S levels decreased after PEG-ASP administration, but antithrombin mean level did not. A bivariant analysis showed that ETP-inh was lower in patients >10-year-old (p=0.05) and in those with non-O blood type (p=0.005). A linear mixed model also showed a higher TGT prothrombotic profile in patients with inherited thrombophilia. TGT could be a biomarker of a high VTE risk in ALL pediatric patients. Patients > 10 years, of non-O blood group and with inherited thrombophilia were associated with a significantly higher thrombotic profile, and an increased profile was also observed after administration of PEG-ASP.

Venous Thromboembolism Characteristics and Outcomes Among RIETE Patients Tested & Untested for Inherited Thrombophilia

Inherited thrombophilia (IT) workup is commonly pursued in venous thromboembolism (VTE) patients. Recent American Society of Hematology (ASH) guidelines recommend a selective approach to IT testing, nevertheless, evidence on whether thrombophilia testing can actually improve patient-important outcomes through tailored management is limited. Data from the large prospective RIETE registry was analyzed to compare VTE risk factors, management and outcomes between patients who were tested for IT and untested patients, during anticoagulant treatment and following its discontinuation. Among 103,818 patients enrolled in RIETE, 21,089 (20.3%) were tested for IT, 8,422 (8.1%) tested positive, and 82,729 (79.7%) were not tested. IT testing was more frequent in patients with VTE provoked by minor risk factors, and less common in those with major risk factors like surgery or active cancer. Choices of anticoagulant treatment did not differ based on IT testing results. Untested patients exhibited inferior outcomes across all VTE categories, with higher rates of VTE recurrence, major bleeding, mortality, and notably, cancer-related mortality. After treatment discontinuation, IT-negative patients with surgically provoked VTE showed lower recurrence rates. For immobilization-related VTE as well as in estrogen-related VTE, no significant differences in recurrence rates were observed between IT-negative and IT-positive patients. However IT-negative patients with pregnancy or postpartum-related VTE, had significantly lower recurrence rates. Patients with unprovoked VTE, particularly those testing positive for IT, had high recurrence rates post-treatment. These findings underscore the complex role of IT testing in managing VTE, supporting personalized treatment strategies that consider VTE risk factors and comorbidities.

P126 Use of oral contraceptives in females with rheumatoid arthritis is not associated with an increased risk of venous thromboembolism: United Kingdom-population based study

Abstract Background/Aims While the use of oral contraceptives in females with immune-mediated inflammatory diseases such as rheumatoid arthritis (RA) is acknowledged as a risk factor for venous thromboembolism (VTE), the interaction between oral contraceptive use and RA is poorly understood. In a large population-based study, we aimed to estimate RA-attributable VTE risk in females using oestrogen contraceptives and/or on hormone replacement therapy (HRT). Methods Females registered with a general practice from January 1999 to December 2018 were identified from the Royal College of General Practitioners Research (RCGP) and Surveillance Centre (RSC) database. Female RA patients and VTE outcome (composite of pulmonary embolism and deep vein thrombosis) were determined using previously-validated algorithms. Female unaffected controls (UCs) were matched 4:1 with RA patients by current age (per year), calendar time, and years since practice registration using nearest neighbour matching, with replacement. Absolute VTE rates over 20 years were compared in RA patients versus matched UCs, overall and in two different subgroups defined by the use of oestrogen contraceptives or HRT. Relative VTE risk over the same period was estimated using Cox proportional hazards models adjusted for sociodemographic and clinical features and established VTE risk factors (BMI [body-mass index], smoking status, alcohol use, evidence of reduced mobility, thrombophilia, fracture of the lower limb and family history of VTE). Results A total of 82,082 female adults were included in this study, of whom 16,634 were RA patients and 65,448 were UCs. Average study follow-up was 8.3 years (standard deviation [SD]=6.2 years). Female RA patients (mean age 58.3, SD 16.5; mean BMI 27.0, SD 5.9) were similar to matched UCs in their clinical characteristics. Compared to UCs, females with RA were less likely to receive oral contraceptives (RA n = 545 [3.3%], UCs n = 2,542 [3.9], p &amp;lt; 0.001) but more likely to receive HRT (RA n = 752 [4.5%], UCs n = 2,460 [3.8], p &amp;lt; 0.001). Unadjusted VTE events rates were consistently higher in females with RA compared to UCs (430.2 per 100,000 person-years [py], 95% confidence interval [CI]: 396.1, 466.3; UC: 260.5 per 100,000 py, 95%CI: 247.1, 274.4) and in those receiving and not receiving oral contraceptives and HRT. Overall, relative risk of VTE was 52% higher in females with RA compared UCs (adjusted hazard ratio [aHR]= 1.52, 95%CI: 1.36, 1.71, p &amp;lt; 0.001). Compared to UCs, relative risk increases were not statistically significant for females with RA receiving oral contraceptives (aHR 1.43; 95%CI 0.60, 3.63, p = 0.46) and HRT (aHR 2.32; 95%CI 0.92, 5.85, p = 0.08). Conclusion UK data suggest that all women with RA are at a similarly increased risk of VTE irrespective of the use of oestrogen contraceptives or HRT, although larger studies are needed to confirm this finding. It is therefore advisable to conduct routine VTE risk factor assessments for all females with RA. Disclosure J. Galloway: Honoraria; JG has received honoraria from Abbvie, Biovitrum, BMS, Celgene, Chugai, Gilead, Janssen, Lilly, Novartis, Pfizer, Roche, Sanofi, Sobi and UC. V. Basey: Corporate appointments; Pfizer employee. A. Barkaway: Corporate appointments; Pfizer employee. S. de Lusignan: Grants/research support; SdeL has received funding through his universities from Eli Lilly, GSK, Astra Zeneca, MSD, Sanofi, Seqirus, Takeda and Moderna. Other; Director of the RCGP RSC. M.H. Buch: Consultancies; M.H.B. has provided expert advice and received/paid to employer consultant fees from AbbVie, Eli Lilly, EMD serono, Gilead, Pfizer and Sanofi. Grants/research support; .H.B. has received research grants paid to her employer from Gilead Ltd, Pfizer Ltd, Roche and UCB.

P052 Rheumatoid arthritis associated risk of venous thromboembolism is not dependent on disease duration: United Kingdom-based population study

Abstract Background/Aims Risk of venous thromboembolism (VTE) is higher in patients with rheumatoid arthritis (RA) compared to the general population; however, whether this risk changes with RA disease duration remains poorly understood. Acknowledging potential heterogeneity in risk by RA duration could support more tailored screening and effective preventive approaches. In a large population-based study, we aimed to characterise the RA-attributable VTE risk in patients with varying disease durations. Methods Adults registered with a general practice from January 1999 to December 2018 were identified from the Royal College of General Practitioners Research (RCGP) and Surveillance Centre (RSC) primary care database. RA patients (diagnosed prior to and during the study period), VTE outcome (as a composite of pulmonary embolism [PE] or deep vein thrombosis [DVT]) and individual PE and DVT outcomes were determined using previously validated algorithms. RA-unaffected controls (UCs) were matched 4:1 with RA patients by current age, sex, calendar time, and years since practice registration using nearest neighbour matching with replacement. Absolute VTE, PE and DVT rates over 20 years were compared in RA patients versus matched UC across four subgroups defined by disease duration (0-2, 2-5, 5-10 and ≥10 years since diagnosis). Across the same subgroups, relative risks over the same period were estimated using Cox proportional hazards models adjusted for sociodemographic and clinical features and established VTE risk factors (body-mass index [BMI], smoking status, alcohol use, evidence of reduced mobility, thrombophilia, fracture of the lower limb and family history of VTE). Results 117,050 individuals were included, of whom 93,640 were UCs and 23,410 were RA patients. Among those with RA, 63.9% were included at or within two years of diagnosis, 7.8% within two to five years of diagnosis, 9.8% within five to ten years of diagnosis, and 18.5% more than 10 years after diagnosis. Average study follow-up for the primary outcome (VTE) was 8.2 years (standard deviation [SD]=6.6 years). RA patients (mean age 59.0, SD 15.5; 28.9% male [n = 6776]; mean BMI 27.1, SD 5.6) were similar to matched UCs in clinical characteristics. Unadjusted VTE events rates were consistently higher in RA patients compared to UCs across all subgroups. Relative risk of VTE was similarly increased in RA patients compared to the general population regardless of the time elapsed since RA diagnosis (adjusted hazard ratios [aHR] range: 1.49-1.63, all p &amp;lt; 0.001). The results obtained when PE (aHR range 1.46-2.02, all p &amp;lt; 0.001) and DVT (aHR range 1.43-1.89, all p &amp;lt; 0.001) were analysed separately were similar to those observed in the composite outcome. Conclusion Healthcare professionals should recognize that individuals with RA face a consistently elevated VTE risk compared to the general population, irrespective of disease duration. This highlights the need for vigilant monitoring and assessment of VTE risk factors even in early-stage cases. Disclosure J. Galloway: Honoraria; JG has received honoraria from Abbvie, Biovitrum, BMS, Celgene, Chugai, Gilead, Janssen, Lilly, Novartis, Pfizer, Roche, Sanofi, Sobi and UC. V. Basey: Corporate appointments; Pfizer employee. S. Rana: Corporate appointments; Pfizer employee. S. de Lusignan: Grants/research support; SdeL has received funding through his universities from Eli Lilly, GSK, Astra Zeneca, MSD, Sanofi, Seqirus, Takeda and Moderna. Other; Director of the RCGP RSC. M.H. Buch: Consultancies; M.H.B. has provided expert advice and received/paid to employer consultant fees from AbbVie, Eli Lilly, EMD serono, Gilead, Pfizer and Sanofi. Grants/research support; M.H.B. has received research grants paid to her employer from Gilead Ltd, Pfizer Ltd, Roche and UCB.

OA38 Venous thromboembolism risk is consistently increased in people with rheumatoid arthritis across different ages, sexes and obesity status: United Kingdom population-based study

Abstract Background/Aims Risk of venous thromboembolism (VTE) is increased in people with rheumatoid arthritis (RA) when compared to the general population, but the variation of this risk among patients is not well understood. Acknowledging the heterogeneity in RA-attributable VTE risk could support tailoring of treatment plans and screening protocols based on an individual’s specific risk profile. In a large population-based study, we aimed to evaluate for variation in RA-attributable VTE risk by age, sex and body-mass index (BMI). Methods Adults registered with a general practice from January 1999 to December 2018 were identified from the Royal College of General Practitioners Research (RCGP) and Surveillance Centre (RSC) primary care database. RA patients and VTE outcome (composite of pulmonary embolism and deep vein thrombosis) were determined using previously validated algorithms. RA-unaffected controls (UCs) were matched 4:1 with RA patients by current age, sex, calendar time, and years since practice registration using nearest neighbour matching with replacement. Absolute VTE rates over 20 years were compared in RA patients versus matched UCs, overall and by age category (18-49, 50-69, ≥70), sex, and BMI category (BMI &amp;lt;25, 25-29.9, ≥30). Across the same subgroups, relative VTE risk over the same period was estimated using Cox proportional hazards models adjusted for sociodemographic and clinical features and established VTE risk factors (BMI, smoking status, alcohol use, evidence of reduced mobility, thrombophilia, fracture of the lower limb and family history of VTE). Results 117,050 individuals were included, of whom 23,410 were RA patients and 93,640 were UCs. Average follow-up was 8.2 years (standard deviation [SD]=6.6 years). RA patients (mean age 59.0, SD 15.5; 28.9% male [n = 6776]; mean BMI 27.1, SD 5.6) were similar to matched UCs in clinical characteristics. Unadjusted VTE events rates were consistently higher in RA patients compared to UCs overall and across all subgroups (overall rates RA: 442.4 per 100,000 person-years [py], 95% confidence interval [CI]: 413.0, 473.2; UC: 262.2 per 100,000 py, 95%CI: 251.9, 273.9); subgroup rates). Similarly, overall relative VTE risk was 46% higher in people with RA compared to UCs (adjusted hazard ratio [aHR]= 1.46, 95%CI: 1.36, 1.56; p &amp;lt; 0.001), and was consistently higher across age-, sex- and BMI-defined subgroups (aHR range: 1.34-2.13, all p &amp;lt; 0.001). Although relative risk was highest in RA patients under 50 years (aHR= 2.13, 95%CI: 1.62-2.79; p &amp;lt; 0.001), this patient subgroup had the lowest absolute risk of VTE (approximately 2.2- and 3.4-fold lower than that observed in those aged 50-69 and ≥70, respectively). Conclusion Clinicians should be aware that risk of VTE is consistently higher in people with RA compared to the general population, regardless of age, sex and BMI. Findings suggest close monitoring and assessment of VTE risk factors is required even in younger individuals with RA. Disclosure J. Galloway: Honoraria; JG has received honoraria from Abbvie, Biovitrum, BMS, Celgene, Chugai, Gilead, Janssen, Lilly, Novartis, Pfizer, Roche, Sanofi, Sobi and UC. V. Basey: Corporate appointments; Pfizer employee. M. Mclean: Corporate appointments; Pfizer employee. S. de Lusignan: Grants/research support; SdeL has received funding through his universities from Eli Lilly, GSK, Astra Zeneca, MSD, Sanofi, Seqirus, Takeda and Moderna. Other; Director of the RCGP RSC. M.H. Buch: Consultancies; M.H.B. has provided expert advice and received/paid to employer consultant fees from AbbVie, Eli Lilly, EMD serono, Gilead, Pfizer and Sanofi. Grants/research support; M.H.B. has received research grants paid to her employer from Gilead Ltd, Pfizer Ltd, Roche and UCB.

Distinct risk profiles for short-term surgical complications and venous thromboembolism exist among extensor mechanism repair procedures.

Extensor mechanism injuries, which comprise patella fractures, patella tendon tearsand quadriceps tendon tears, are severely debilitating injuries and a common cause of traumatic knee pathology that requires surgical intervention. Risk factors for short-term surgical complications and venous thromboembolism (VTE) in this population have not been well characterised. The aim of this study was to identify perioperative risk factors associated with these short-term complications. The National Surgical Quality Improvement Program database was used to identify patients who underwent an isolated, primary extensor mechanism repair from 2015 to 2020. Patients were stratified by injury type. Demographic data were collected and compared. A multivariate logistic regression was used to control for demographic and comorbid factors while assessing risk factors for developing short-term complications. A total of 8355 patients were identified for inclusion in this study. Overall, 3% of patients sustained short-term surgical complications and 1% were diagnosed with VTE within 30 days of surgery. Patella fracture fixation had a nearly twofold higher risk for surgical complications compared to quadriceps tendon repair (p = 0.004). Patella tendon repair had a twofold higher risk for VTE (p = 0.045), specifically deep vein thrombosis (p = 0.020), compared to patella fracture fixation. Increasing age, smokingand American Society of Anesthesiologists Classifications 3 and 4 were also found to be risk factors for surgical complications (p = 0.012, p = 0.004, p = 0.011 and p = 0.032, respectively). This study used a nationally representative, widely validated, peer-reviewed database to provide valuable insights into risk factors for short-term postoperative complications associated with extensor mechanism repair procedures, revealing notable differences in risk profiles among distinct surgical procedures. The results of this study will inform surgeons and patients in enhancing risk assessment, guiding procedure-specific decision-making, optimising preoperative care, improving postoperative monitoringand contributing to future research of extensor mechanism injuries. Level III.

754 Venous Thromboembolism Incidence and Risk Factors in Burn Patients

754 Venous Thromboembolism Incidence and Risk Factors in Burn Patients

Association between Homocysteine and Vitamin D Levels in Asymptomatic Korean Adults.

An increased homocysteine level is a risk factor for cardiovascular disease, venous thromboembolism, cerebrovascular disease, and chronic kidney disease. In addition, vitamin D deficiency is associated with coronary artery disease and metabolic disorders. The present study included data from 1375 adults (895 men and 480 women) with a mean age of 52.62 ± 9.94 years who visited the Health Promotion Center of the University Hospital in Gyeonggi-do, Republic of Korea from January 2018 to December 2022 for routine checkups that included assessments of their homocysteine and vitamin D levels. Homocysteine levels were positively associated with age, a history of hypertension, a history of diabetes, current smoking habits, and levels of low-density lipoprotein cholesterol, creatinine, uric acid, and high-sensitivity C-reactive protein. By contrast, vitamin D levels were negatively associated with serum levels of homocysteine after adjusting for covariates (β = -0.033, p < 0.001). Additional long-term prospective studies are needed to elucidate the presence of a causal relationship between vitamin D status and serum levels of homocysteine in asymptomatic Korean adults. An intervention trial is warranted to determine whether the administration of vitamin D is helpful for the primary prevention of cardiovascular disease by lowering the homocysteine level in this population.

Epidemiology, Etiology, and Pathophysiology of Pulmonary Embolism

AbstractOver the last 20 years, there has been a progressive increase in the incidence of pulmonary embolism (PE) diagnosis in the United States, Europe, and Australia. Increased use of computed tomography pulmonary angiography has likely contributed in part to this rising incidence. However, it is pertinent to note that the burden of comorbidities associated with PE, such as malignancy, obesity, and advanced age, has also increased over the past 20 years. Time-trend analysis in North American, European, and Asian populations suggests that mortality rates associated with PE have been declining. The reported improved survival rates in PE over the past 20 years are likely, at least in part, to be the result of better adherence to guidelines, improved risk stratification, and enhanced treatment. Factors contributing to the development of venous thromboembolism (VTE) include stasis of blood, hypercoagulability, endothelial injury, and inflammation. In 70 to 80% of cases of PE, the thrombi embolizes from the proximal deep veins of the lower extremities and pelvis. Strong risk factors for VTE include lower extremity fractures and surgeries, major trauma, and hospitalization within the previous 3 months for acute myocardial infarction or heart failure with atrial fibrillation. Acute PE causes several pathophysiological responses including hypoxemia and right ventricle (RV) failure. The latter is a result of pulmonary artery occlusion and associated vasoconstriction. Hemodynamic compromise from RV failure is the principal cause of poor outcome in patients with acute PE.

(1018) - Incidence and Risk Factors of Venous Thromboembolism in Lung Transplant Recipients

(1018) - Incidence and Risk Factors of Venous Thromboembolism in Lung Transplant Recipients

The plasma miRNome and venous thromboembolism in high-grade glioma: miRNA Sequencing of a nested case-control cohort.

Patients with high-grade gliomas are at high risk of venous thromboembolism (VTE). MicroRNAs (miRNAs) are small non-coding RNAs with multiple roles in tumour biology, haemostasis and platelet function. Their association with VTE risk in high-grade glioma has not been comprehensively mapped so far. We thus conducted a nested case-control study within 152 patients with WHO grade IV glioma that had been part of a prospective cohort study on VTE risk factors. At inclusion a single blood draw was taken, and patients were thereafter followed for a maximum of 2 years. During that time, 24 patients (16%) developed VTE. Of the other 128 patients, we randomly selected 24 age- and sex-matched controls. After quality control, the final group size was 21 patients with VTE during follow-up and 23 without VTE. Small RNA next-generation sequencing of plasma was performed. We observed that hsa-miR-451a was globally the most abundant miRNA. Notably, 51% of all miRNAs showed a correlation with platelet count. The analysis of miRNAs differentially regulated in VTE patients-with and without platelet adjustment-identified potential VTE biomarker candidates such as has-miR-221-3p. Therewith, we here provide one of the largest and deepest peripheral blood miRNA datasets of high-grade glioma patients so far, in which we identified first VTE biomarker candidates that can serve as the starting point for future research.

A commentary on 'Risk factors for incident venous thromboembolism in patients with renal tumor and inferior vena cava tumor thrombus: A retrospective case-control study'.

A commentary on 'Risk factors for incident venous thromboembolism in patients with renal tumor and inferior vena cava tumor thrombus: A retrospective case-control study'.

An epidemiologic study comparing cancer- and noncancer-associated venous thromboembolism in a racially diverse Southeastern United States county

BackgroundCancer-associated venous thromboembolism (CA-VTE) represents a major cause of morbidity and mortality in patients with cancer. Despite poor outcomes, there is an ongoing knowledge gap in epidemiologic data related to this association. ObjectivesTo compare venous thromboembolism (VTE) characteristics, risk factors, and outcomes between patients with and without active cancer in a racially diverse population. MethodsOur surveillance project occurred at the 3 hospitals in Durham County, North Carolina, from April 2012 through March 2014. Electronic and manual methods were used to identify unique Durham County residents with VTE. ResultsWe identified 987 patients with VTE during the surveillance period. Of these, 189 patients had active cancer at the time of their VTE event. Patients with CA-VTE were older (median age: 69 years vs 60 years, P < .0001) and had a lower body mass index (median body mass index: 26.0 kg/m2 vs 28.4 kg/m2, P = .0001) than noncancer patients. The most common cancers in our cohort were gastrointestinal, breast, genitourinary, and lung. The proportion of VTE cases with pulmonary embolism (PE) was greater in the cancer cohort compared with that in the noncancer cohort (58.2% vs 44.0%, P = .0004). Overall survival was lower in the CA-VTE group than in patients without cancer (P < .0001). Black patients with CA-VTE had lower proportion of PE (52.3% vs 67.1%, P = .05) but had decreased survival (P < .0003) in comparison with White patients. ConclusionFuture studies may be needed to continue to evaluate local and national VTE data to improve VTE prevention strategies and CA-VTE outcomes.

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.