"Unpatients" in haemostasis and thrombosis. A yardstick of current paths in healthy carriers of a genetic susceptibility.

Abdominoplasty in patients with obesity carries a heightened risk of venous thromboembolism (VTE) due to a proinflammatory and hypercoagulable baseline. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are increasingly used for weight loss and have demonstrated anti-inflammatory and antithrombotic properties, but their role in aesthetic surgery remains unexplored. We conducted a prospective, monocentric, observational study of 60 female patients (BMI ≥30 kg/m2 before weight loss) undergoing standardized abdominoplasty with rectus plication. Two cohorts were compared: (1) 30 patients treated with GLP-1 RAs (semaglutide or tirzepatide) for ≥12 weeks preoperatively, and (2) 30 patients achieving comparable weight loss through structured lifestyle intervention. Perioperative management, including VTE prophylaxis, was identical. Biomarkers (CRP, IL-6, fibrinogen, D-dimer, PAI-1) were measured at baseline and on postoperative days (POD) 1, 3, and 7. VTE incidence was assessed clinically and by routine Doppler ultrasound on POD7. Weight loss and preoperative metabolic profiles were comparable between groups. Postoperatively, biomarker increases were significantly attenuated in the GLP-1 RA group: CRP (+18 vs. +28 mg/L, p<0.01), IL-6 (+12 vs. +20 pg/mL, p<0.01), fibrinogen (+40 vs. +65 mg/dL, p=0.02), D-dimer (+0.8 vs. +1.3 µg/mL, p<0.01), and PAI-1 (+5 vs. +9 ng/mL, p<0.05). No symptomatic VTE occurred in the GLP-1 group versus two cases (6.7%) in controls; subclinical DVT occurred in 1 (3.3%) versus 3 (10%), respectively. Hospital stay was shorter with GLP-1 therapy (1.8 vs. 2.2 days, p=0.04). Preoperative GLP-1 RA therapy was associated with reduced perioperative thromboinflammatory response and a favorable trend toward fewer VTE events and complications, despite equivalent weight loss. GLP-1 RAs may provide dual benefits-metabolic optimization and risk modulation-in high-BMI abdominoplasty candidates. Larger randomized trials are warranted. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Antithrombotic evaluation of postpartum venous thromboembolism (VTE) after anticoagulant therapy is challenging because of the lack of high-quality clinical evidence. To identify and validate a machine learning model to predict thrombus regression in postpartum VTE patients. This study constructed three cohorts of postpartum VTE patients receiving low-molecular-weight heparin (LMWH): retrospective (n = 200), prospective (n = 50), and external (n = 29) cohorts. The main endpoint was imaging-based thrombus regression. Based on clinical guidelines and literature, we screened 16 potential predictors. The retrospective dataset was analyzed using eight machine learning models to predict thrombus regression after anticoagulant therapy. The performance of the model was evaluated by the area under the receiver operating characteristic curve (AUC-ROC), residual analysis, accuracy, sensitivity and specificity. The optimal model was selected based on its comprehensive performance and further validated on the prospective and external cohorts. Model interpretability was analyzed using variable importance and partial dependence plots. Thrombus regression was significantly associated with anti-Xa activity (p = 0.009), antithrombin III levels (p = 0.028), and D-dimer levels (p = 0.024). Of the eight models, the random forest (RF) model demonstrated the best predictive performance, with the AUC-ROC value of 0.831(95%CI 0.696-0.967), accuracy of 0.77, sensitivity of 0.45, specificity of 0.89, and the highest accuracy in predicting thrombus regression events in the prospective (94.29%) and external (90.00%) postpartum VTE datasets. The key predictive variables were anti-Xa activity, antithrombin III levels, D-dimer levels, and body mass index (BMI). Based on data from the three cohorts of patients with postpartum VTE, the RF model was identified as the optimal model for predicting thrombus regression events, with anti-Xa activity, antithrombin III levels, D-dimer levels, and BMI serving as key predictors. This study may help assess changes in the thrombotic state of postpartum VTE patients and guide clinical precision medication.

This study aims to perform a systematic literature review (SLR) concerning the safety of synthetic and biological disease-modifying antirheumatic drugs (DMARDs) for the 2025 update of European Alliance of Associations for Rheumatology (EULAR) recommendations for the management of rheumatoid arthritis (RA). Medline, Embase, Cochrane CENTRAL, and Web of Science were searched for observational and randomised controlled trials with a primary endpoint of DMARD safety on the conventional synthetic (cs-), biological (b-), and targeted synthetic-DMARDs, as well as glucocorticoids, published between January 14, 2022, and January 22, 2025. Separate searches on DMARD monitoring were conducted from database inception to January 22, 2025. A comparator group was required for inclusion. All safety outcomes were included. A total of 3837 articles were identified, with 321 selected for full-text review; 71 articles were included. Across the evidence base, infections were the most frequently assessed outcome: 13 studies examined serious or hospitalised infections, usually as composite endpoints of bacterial, opportunistic, and herpes zoster infection, while 1 addressed nonserious infections. Serious infections were more common with bDMARDs than csDMARDs. Janus kinase inhibitors (JAKis) showed a higher herpes zoster risk than bDMARDs. Tuberculosis risk was not increased with JAKis compared with bDMARDs, but was higher with infliximab and adalimumab compared with etanercept. Fifteen studies evaluated malignancy, split evenly between analyses of any malignancy and those excluding nonmelanoma skin cancer (NMSC); 2 focused on melanoma and 2 on NMSC. Increased NMSC was noted in patients with RA using DMARDs compared with the general population, with no link to a specific DMARD. Cardiovascular and thromboembolic events were reported in 20 studies. No consistent evidence of increased major adverse cardiovascular events risk with JAKis compared with bDMARDs was identified. Venous thromboembolism risk appeared elevated with JAKis compared with bDMARDs, driven mainly by pulmonary embolism. Fourteen studies reported retention and adverse event-related withdrawals, and 8 assessed other specific adverse events. Gastrointestinal perforation and demyelinating disease were each reported in 3 studies. No eligible articles were identified in searches on DMARD monitoring. There has been a notable increase in studies evaluating safety outcomes, with the majority of these being observational studies focusing primarily on malignancy, thromboembolic, and cardiovascular events, with most studies pertaining to JAKi safety. A substantial proportion of studies in this SLR relied on claims databases to evaluate safety outcomes, a practice that carries important methodological limitations for safety research. Surprisingly, not many studies looked into glucocorticoid safety outcomes over the past 3 years. This SLR, along with the SLR on efficacy of DMARDs, informed the 2025 update of the EULAR recommendations for management of RA with synthetic and biological DMARDs.

Despite strong evidence and guidelines supporting prophylactic anticoagulation for ambulatory patients with cancer starting systemic cancer-directed therapy who are at high risk of venous thromboembolism (VTE), uptake in practice is limited. We evaluated the real-world impact of prophylactic anticoagulation in such patients receiving guideline-based care. We conducted an observational cohort study of patients assessed as part of a multidisciplinary VTE prevention program (the Vermont model) from 2016 to 2021. For this study, we included outpatients at high risk of VTE based on a Khorana risk score or Protecht risk score of ≥3. Based on the individualized decision making, patients either received or did not receive prophylactic anticoagulation. The primary outcome was VTE at 6 months after risk assessment. The secondary outcome was all-cause mortality at 6 months. Of 573 high-risk patients assessed during the study period, 340 (59%) received thromboprophylaxis and 233 (41%) did not. Eleven (3.2%) on thromboprophylaxis developed a VTE within 6 months, compared with 18 (7.7%) not on thromboprophylaxis. After adjusting for age, sex, BMI, cancer stage, chemotherapy, immunotherapy, distance from center, and history of VTE, thromboprophylaxis reduced VTE (adjusted odds ratio [OR], 0.36 [95% CI, 0.16 to 0.80]) compared with no thromboprophylaxis. Of deaths within 6 months, 57 (16.8%) occurred in the thromboprophylaxis group versus 73 (31.3%) in the no thromboprophylaxis group (adjusted OR, 0.46 [95% CI, 0.30 to 0.71]). Ambulatory patients with cancer at high risk of VTE who received prophylactic anticoagulation had improved clinical outcomes with fewer VTE events and less mortality. Our real-world data support available clinical trial data and underscore the importance of the provision of guideline-directed care in the cancer outpatient setting.

BackgroundEffective patient education is crucial in preventing venous thromboembolism (VTE), improving patient outcomes, and reducing health care costs. However, traditional educational methods often lack engagement and fail to address individual patient needs comprehensively.ObjectiveThis study aimed to develop and preliminarily validate an immersive, large language model–based patient education system for VTE designed to promote patient engagement and care adherence by delivering highly relevant, actionable, and patient-centered information.MethodsWe developed ChatVTE, an interactive, intelligent patient education platform, by integrating a retrieval-augmented large language model (Qwen1.5-7B) with text-to-speech and lip-synch technologies. The system’s performance was initially assessed through a comparative evaluation against ChatGPT. This involved using a standardized set of VTE-related questions, administered from December 10 to 31, 2024, with responses rigorously evaluated by 4 VTE domain experts using a 5-point Likert scale for accuracy, completeness, consistency, and safety. Subsequently, we consecutively enrolled a prospective cohort of 25 adult inpatients with VTE from the Departments of Pulmonary Vascular and Thrombotic Diseases and General Surgery at the Sixth Medical Center of the Chinese People’s Liberation Army General Hospital between March 1 and May 31, 2025. These participants engaged with the ChatVTE system throughout their inpatient stay and completed postintervention assessments upon discharge.ResultsExpert evaluation demonstrated that ChatVTE significantly outperformed ChatGPT in accuracy, completeness, consistency (all P<.001, r>0.5), and safety (P=.01, r=0.327). Among the 25 enrolled patients (age: mean 55.4, SD 13.2 years), ChatVTE achieved high average scores (mean score >4.0/5.0) in 8 of the 9 experience dimensions evaluated but received a notably lower score in the emotional support domain (1.92/5.0).ConclusionsThis study validates the feasibility of ChatVTE in the management of patients with VTE, demonstrating its potential to enhance the quality of patient–health care provider interaction and the efficacy of knowledge dissemination. These preliminary findings suggest that ChatVTE could be a valuable tool for improving patient education and facilitating shared clinical decision-making.

Pancreatic cancer demonstrates the greatest prevalence of thrombosis linked to malignancy in solid tumors, accompanied by a markedly heightened risk of venous thromboembolism (VTE). Early occurrence of VTE in cancer serves as a crucial predictor of adverse prognosis, jeopardizing patient survival and quality of life. The hypercoagulable condition triggered by the tumor microenvironment, integrated with host genetic predisposition and treatment-associated hazards, collaboratively escalates VTE susceptibility. This review methodically outlines the pathophysiology and elevated risk elements for lower extremity deep vein thrombosis (DVT) in pancreatic cancer, while appraising the efficacy of present preventive approaches, seeking to establish a theoretical groundwork for refining clinical management.

As the demand for total shoulder arthroplasty (TSA) increases, it is imperative to optimize preoperative risk factors. While glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are used for glycemic control or weight management in patients with obesity or diabetes, the impact of preoperative use on postoperative TSA outcomes in non-obese patients is unknown. We sought to answer the question: Does preoperative use of GLP-1 RAs lead to increased risk of medical or surgical complications after TSA? We conducted a retrospective cohort study using data from the TriNetX Network to analyze non-obese patients (BMI <30 kg/m2) who underwent anatomic or reverse shoulder arthroplasty between 2013 (the inception of the network) and January 2024 and had at least 1 year of follow up. Patients were categorized by preoperative GLP-1 RA use and matched 1:1 using propensity scores to balance the cohorts based on demographic variables and comorbidities. Outcomes assessed at 90 days and 1 year included revision surgery, emergency department visits, readmission, venous thromboembolism, pulmonary embolism, acute kidney injury, prosthetic joint stiffness, postoperative rotator cuff tear, dislocation, periprosthetic fracture or joint infection, surgical site infection, aspiration, cardiac arrest, and blood transfusion. Among 108 352 non-obese patients, 845 used GLP-1 RAs preoperatively. After propensity score matching, 845 patients remained in each cohort with no significant baseline differences. In the 90 day postoperative period, there were no significant differences in any medical complications between the GLP-1 RA and control groups. Similarly, at 1 year, there were no significant differences in any medical or surgical complications between groups. This retrospective cohort study found that preoperative GLP-1 RA use in non-obese TSA patients was not associated with an increased rate of major postoperative medical or surgical complications. Level III: retrospective cohort study.

The aim of this paper is to synthesize current evidence regarding the efficacy, safety, and clinical implementation of anticoagulation in patients with PAD, evaluating the impact of different regimens on limb patency, cardiovascular mortality, and bleeding complications across various clinical settings. The review utilises 110 original studies with 2351292 total participants (topic deduplicated ΣN). The evidence map identifies low-dose rivaroxaban plus aspirin as the most consistent anticoagulation-related signal in PAD, with reported reductions of 24% in MACE and 43% to 47% in MALE, alongside a major bleeding increase with hazard ratios around 1.70 to 1.78. This pattern was most persuasive in symptomatic and post-revascularization PAD, where intensified therapy also appeared to reduce total thrombotic events and venous thromboembolism, supporting a practical role for dual pathway inhibition in carefully selected patients. At the same time, the broader evidence base indicates that full-dose or nonspecific anticoagulation strategies do not uniformly translate across PAD contexts, particularly after some endovascular procedures or in younger revascularized cohorts, where harm signals and treatment heterogeneity remain important concerns. In PAD patients with concomitant atrial fibrillation, the mapped literature also supports maintaining indicated oral anticoagulation and suggests DOAC-based strategies may be preferable to warfarin for overall vascular outcomes. Overall, the review supports a selective, risk-stratified approach that balances limb and cardiovascular protection against bleeding risk rather than a uniform escalation of anticoagulation in all PAD patients. Future research should prioritize indication-specific randomized and prospective comparative studies to define optimal regimens for post-intervention PAD, PAD-VTE overlap, and AF-PAD populations, while improving bleeding-risk stratification and real-world implementation.

Optimal timing of initiation of pharmacologic venous thromboembolism (VTE) prophylaxis following intracerebral hemorrhage is controversial. This study aims to assess the association between the timing of pharmacologic VTE prophylaxis initiation and the risk of VTE and hemorrhagic complications. This was a multicenter, retrospective cohort study completed at 7 community hospitals. This study included patients with nontraumatic intracerebral hemorrhage admitted from August 1, 2023, to July 31, 2024. A total of 111 patients were assessed and categorized based on the administration of early (≤48h) versus delayed (>48h) initiation of VTE prophylaxis. Findings showed no statistically significant difference in the primary outcome of the incidence of VTE with early versus delayed initiation of VTE prophylaxis (5% vs. 8%, P=0.713). Secondary outcomes included incidence of deep vein thrombosis (5% vs. 8%, P=0.713), pulmonary embolism (0% vs. 0%), hematoma enlargement (16% vs. 15%, P=0.623), median intensive care unit (ICU) length of stay (3 vs. 3.5d, P=0.670), hospital length of stay (7 vs. 8d, P=0.724), inpatient all-cause mortality (8% vs. 7%, P=1.000), and discharge disposition. Early pharmacologic VTE prophylaxis (≤48h from ICH onset) was not found to be statistically significant in lowering the incidence of VTE. This occurred with no statistically significant differences in hematoma enlargement, increased inpatient mortality, or increased length of ICU/hospital stay. Additional adequately powered studies are needed to determine if early pharmacologic VTE prophylaxis is associated with a lower incidence of VTE.

ABSTRACTBackground and AimsPatients undergoing pancreatectomy and hepatectomy are at high risk of venous thromboembolism (VTE) and bleeding. Mechanical prophylaxis effectively prevents VTE, yet optimal management strategies remain debated. This study compared two mechanical prophylaxis regimens in these surgical populations.MethodsThis retrospective study (January 2017–December 2022) included patients managed under distinct protocols: those admitted during 2017–2018 received the Assessment‐Prophylaxis (AP) regimen (n = 176), while those admitted during 2019–2022 received the Assessment‐Screening‐Prophylaxis‐Evaluation (ASPE) regimen (n = 627). Univariate analysis (chi‐square test) and multivariate logistic regression were performed to assess hospital‐associated VTE (HA‐VTE) outcomes.ResultsThe ASPE group demonstrated higher VTE risk assessment rates at admission (94.4% vs. 46.0%, p < 0.001), ultrasound screening rates (45.3% vs. 1.2%, p < 0.001), and postoperative mechanical prophylaxis rates (98.4% vs. 92.8%, p = 0.001). However, HA‐VTE incidence did not differ significantly between groups (1.9% vs. 1.1%, p = 0.486). Multivariate analysis identified prolonged hospitalization (OR = 1.057, 95% CI: 1.024–1.090, p = 0.001) and admission VTE risk assessment (OR = 9.347, 95% CI: 1.089–80.214, p = 0.042) as independent risk factors for HA‐VTE, while postoperative mechanical prophylaxis reduced HA‐VTE risk (OR = 0.081, 95% CI: 0.016–0.408, p = 0.002).ConclusionsThe ASPE regimen improved compliance with VTE prevention protocols. Postoperative mechanical prophylaxis significantly reduced HA‐VTE incidence, supporting its clinical adoption.

Venous thromboembolism (VTE) is a common complication among patients with cancer. While randomized clinical trials have established the safety and efficacy of direct oral anticoagulants (DOACs) and low-molecular-weight heparin (LMWH) relative to warfarin for the treatment of cancer-associated thrombosis, emerging evidence suggests that warfarin may be associated with improved overall survival in patients with malignancy. To evaluate survival outcomes among patients with cancer and VTE treated with warfarin compared with other anticoagulants within the Veterans Affairs (VA) Health Care System and analyze the association of international normalized ratio (INR) exposure and overall survival. Among 12 298 propensity-matched patients (mean age 69 years; 97% men), warfarin use was associated with a 16% lower risk of mortality compared with other anticoagulants (hazard ratio [HR], 0.84; (95% CI, 0.80-0.88); P < .001). Median survival was 1457 days in the warfarin group vs 1045 days in the non-warfarin group. Survival benefits were consistent across subgroups defined by tumor type, stage, and demographic characteristics. In landmark analyses the greatest benefit was observed with extended periods in the INR range of 2.5 to 3.0 (HR, 0.81; 95% CI, 0.75-0.87). In this population-based cohort study of patients with cancer and VTE, warfarin use was associated with improved survival compared with other anticoagulants. The greatest benefit was observed among patients who maintained an INR between 2.5 and 3.0.

Patient: Female, 78-year-oldFinal Diagnosis: No bleedingSymptoms: No bleeding • no VTEClinical Procedure: —Specialty: Pharmacology and PharmacyObjective: Unusual or unexpected effect of treatmentBackgroundTotal knee arthroplasty (TKA) is associated with a significant risk of venous thromboembolism (VTE), making postoperative thromboprophylaxis essential. In patients with end-stage renal disease (ESRD) who are on hemodialysis, the choice of anticoagulant is complicated by altered drug metabolism. Although oral vitamin K antagonists (eg, warfarin) and unfractionated heparin are commonly used, there are some challenges that minimize their utilization. Direct oral anticoagulants such as apixaban can overcome these challenges, and pharmacokinetic data support their use in ESRD, but clinical evidence supporting the safety and efficacy of apixaban is limited.Case ReportWe describe the case of a 78-year-old woman with ESRD on regular hemodialysis who underwent elective right TKA. Her postoperative course was notable only for a hemoglobin drop consistent with expected surgical blood loss, and she remained stable with no signs of bleeding or infection. Initial prophylaxis was provided with unfractionated heparin during her hospital stay. Considering her advanced age, need for hemodialysis at another center, and the logistical challenges of warfarin monitoring, apixaban 2.5 mg twice daily was selected as an off-label discharge option for VTE prophylaxis. The patient tolerated apixaban well, with no reported bleeding or thromboembolic complications during follow-up or dialysis sessions.ConclusionsApixaban appears to be a safe alternative for VTE prophylaxis after TKA in selected dialysis patients; however, its use remains off-label. More robust data are needed to guide clinical decision-making.

Estrogen upregulates lactoferrin to induce hypercoagulability for hemostatic protection during pregnancy.

Our objective wasto automate the extraction of clinical diagnoses from diagnostic and nondiagnostic radiology reports using modern language models and structured electronic health record (EHR) data. We selected venous thromboembolism (VTE) as our use case for which imaging is the gold standard but is not always fully diagnostic. We extracted venous duplex, computed tomography, and ventilation-perfusion scan reports from the Cleveland Clinic EHR system for patients admitted 2011-2020. Report ground truths were positive, negative, or nondiagnostic. We compared multiple large language models (LLMs) and bidirectional encoder representations from transformers (BERT) models on multiclass classification in holdout evaluation sets. Error analysis guided iterative LLM prompt design and maximized the detection of nondiagnostic reports. ICD-10 codes and therapeutic anticoagulation data were used to adjudicate VTE diagnoses for patients with nondiagnostic reports. We identified 82,476 radiology reports among 213,724 patients. Across models, multiclass areas under the receiver operating characteristics and precision-recall curves ranged from 0.83 to 0.96 and 0.57 to 0.94. The most accurate model, Llama-3.3, detected 95% of VTE-positive reports with a precision of 99.6% and detected87% of nondiagnostic reports with a precision of 88%. The positive detection rate increased to 98% when we paired structured EHR variables with minimal chart review (0.7% of the evaluation set) to adjudicate diagnoses for patients with nondiagnostic reports. In summary,Llama-3.3 was highly sensitive and specific forpositive VTE diagnoses and nondiagnostic radiology reports. We integrated an LLM, structured EHR variables, and limited chart review for successful management of diagnostic uncertainty in automated information extraction from radiology reports.

Cerebral venous thrombosis is a rare stroke type that primarily affects younger women. Contemporary large international efforts have improved our understanding of the natural history and management of this rare disease, yet important evidence gaps persist across the disease continuum. Management of cerebral venous thrombosis can be conceptualized into multiple phases: acute management, primary therapy, secondary prevention, and chronic recovery. Acute treatment centers on anticoagulation, including in the presence of intracranial hemorrhage. Endovascular therapy and decompressive craniectomy are reserved for selected severe cases. Direct oral anticoagulants appear comparable to vitamin K antagonists for most patients during primary treatment, though optimal lead-in duration and treatment length remain uncertain. Decisions regarding extended anticoagulation for secondary prevention require individualized assessment of recurrence and bleeding risk. Patients with cancer, antiphospholipid antibody syndrome, prior venous thromboembolism, and idiopathic events are at the highest thromboembolic risk. Long-term sequelae, including fatigue, headache, cognitive and mood disturbances, epilepsy, and intracranial hypertension, contribute substantially to morbidity despite high rates of functional independence. Heavy menstrual bleeding may impact young women on anticoagulation. Recognition and management of these outcomes are essential for comprehensive care.

Rapid transportation of neurosurgical patients, particularly those with acute spinal trauma, is critical due to the direct association between total prehospital time and mortality. While existing aeromedical guidelines focus primarily on helicopter (rotor-wing) transport, there is limited evidence consolidating the effects of fixed-wing aircraft transport, which exposes patients to unique physiological stressors due to higher operational altitudes. Using a recognised framework for scoping reviews, a European-based research team conducted biweekly discussions to ensure a comprehensive approach.This scoping review utilized a four-phase framework: identification, screening, data extraction, and contextualisation. A systematic literature search via OVID databases up to September 19, 2024, and manual searches of 15 journals identified studies involving fixed-wing aircraft transport for spinal pathology patients, excluding helicopter or animal studies.Additionally, a panel of experts in neurosurgery and aviation reflected on their experiences and transferable lessons. 12 studies were included, covering 105 spinal injury cases and 1 spinal tuberculosis case. Key physiological factors unique to fixed-wing transport include reduced atmospheric pressure, low humidity, extended transport duration, smoother acceleration/deceleration, and better medical accessibility compared to rotor-wing transport. Recommendations from the literature and expert experiences emphasise respiratory stability, humidification, oxygen supplementation, pressure injury prevention, bowel/bladder management, airway cuff pressure management, and venous thromboembolism prophylaxis. There is an urgent need for evidence-based recommendations tailored to fixed-wing transportation of spinal pathology patients, emphasizing altitude-induced physiological changes to optimize patient safety. Further targeted research is essential to develop comprehensive clinical protocols.

Prospectively Screening for Venous Thromboembolism in Patients with Esophagectomy for Cancer Improves Survival: The Complexity of Simplicity.

The epidemiology of venous thromboembolic events in a severe trauma cohort admitted to the intensive care unit of an Australian major trauma centre over a five-year period.

ASCO recommends extended venous thromboembolism (VTE) prophylaxis with low-molecular-weight heparin (LMWH) or direct oral anticoagulants (DOACs) following cancer surgery. However, these recommendations were based on trials using routine venography, which detects asymptomatic VTEs, and real-life efficacy is not well studied. We aimed to assess the association of extended VTE prophylaxis with the incidence of clinically significant VTE after elective cancer surgery. In this retrospective, population-based cohort study, we identified patients who underwent surgical resection for lung, breast, esophageal, gastric, pancreas, and colon cancer from 2010 to 2017 using the SEER-Medicare linked dataset. Patients were divided into 1 of 2 main groups for comparative analyses: those who received extended VTE prophylaxis after cancer surgery and those who did not. Patients who received extended VTE prophylaxis after cancer surgery were identified as those prescribed prophylactic doses of LMWH or a DOAC within 7 days of discharge, as captured in Medicare Part D files. A total of 113,739 Medicare beneficiaries were identified, of whom 1,570 (1.4%) received extended VTE prophylaxis. There was a year-over-year increase in the use of extended VTE prophylaxis during the study period, rising from 0.6% in 2010 to 3.3% in 2017. The overall incidence of VTE was 1.6% at 1 month, 4.3% at 6 months, 5.7% at 12 months, with significant differences observed across cancer types (P<.001). However, patients who received extended VTE prophylaxis had a higher 1-year cumulative incidence of postoperative VTE compared with those who did not (11.4% vs 5.3%; P<.001), an association that was consistent across cancer sites. In adjusted analyses, extended VTE prophylaxis was independently associated with an increased risk of VTE (hazard ratio, 1.6; 95% CI, 1.3-2.0; P<.001). Extended prophylaxis was also associated with a higher 1-year incidence of bleeding events compared with patients who did not receive prophylaxis (12.0% vs 8.5%; P<.001). The utilization of extended VTE prophylaxis after cancer surgery remains low, although it has increased every year. Paradoxically, patients who received extended VTE prophylaxis had higher incidences of clinically significant VTE and bleeding compared with those who did not, likely reflecting patient selection and surveillance bias after surgery. In light of these findings, national guidelines recommending postoperative extended VTE prophylaxis, and its use as a surrogate for quality of care, should continue to be re-examined.