Multiple Risk Factors For Venous Thromboembolism Research Articles

Prevalence of risk factors for venous thromboembolism and aspirin resistance in Australian patients undergoing total hip and knee arthroplasty.

Aspirin is used for venous thromboembolism (VTE) prophylaxis after total hip and knee arthroplasty (THA/TKA). However, its efficacy is unclear in patients with multiple VTE risk factors and at risk of aspirin resistance (AR). To determine the prevalence of risk factors for VTE and AR in patients after THA/TKA and to determine the relationship between risk factors and drugs prescribed for thromboprophylaxis. A retrospective cohort study of elective-THA/TKA in six Australian hospitals over a 1-year period. Medical records were manually reviewed to determine demographics, thromboprophylaxis regimen and presence of risk factors. The relationship between individual and cumulative risk factors with the thromboprophylaxis regimen was determined. In total, 1011 patients were included with a mean (SD) age of 65.9 (±11.0) years, and 56.4% were female. The five most prevalent risk factors were obesity (59.1%), age ≥65 years (58.2%), hypertension (45.3%), dyslipidaemia (35.9%) and diabetes (19.7%). Most patients had ≥1 risk factor for VTE (93.6%) and AR (93.6%), with 49.0% and 35.0% having ≥3 concurrent VTE and AR risk factors, respectively. The only significant relationship between risk factors and drugs was diabetes (P < 0.01). Rivaroxaban was more commonly used as the number of concurrent VTE risk factors increased (P < 0.05). Patients had a high prevalence of VTE and AR risk factors, suggesting aspirin may not be beneficial in many patients. Only diabetes was linked to the selection of thromboprophylaxis. Patients who received rivaroxaban had a greater average number of VTE risk factors. Guidelines should promote individualised prescribing in higher-risk patients.

Concordance between risk scales for venous thromboembolism in patients treated in emergency departments.

To evaluate agreement between risk-assessment models for venous thromboembolism (VTE) in patients hospitalized for medical conditions and to analyze variables associated with the decision to prescribe pharmacological thromboprophylaxis in hospital emergency departments (EDs). Conclusions. Prospective observational multicenter cohort study. We included adults attended in 15 hospital EDs who were hospitalized for medical conditions, calculating VTE risk according to the International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) score, the Padua Prediction Score (PPS), and the National Institute for Health and Care Excellence (NICE) score. In addition to assessing interscore concordance, we analyzed variables associated with the prescription of thromboprophylaxis in the ED. A total of 1203 patients were included. The PADUA, IMPROVE, and NICE scales assigned high risk scores for 68.7%, 47.4%, and 69.5% of the patients, respectively. The κ statistic for agreement between the PADUA and NICE scores was 0.80 (95% CI, 0.76-0.84); 102 patients (8.5%) had discordant scores. The κ statistics for agreement between the IMPROVE score and the PADUA and NICE classifications were 0.47 (95% CI, 0.43-0.52) and 0.37 (95% CI, 0.33-0.42), respectively; 322 (26.8%) and 384 patients (31.9%), respectively, had discordant scores. Variables associated with starting thromboprophylaxis in the ED were a diagnosis of acute myocardial infarction or stroke (adjusted odds ratio [aOR], 4.26), immobility in the last 2 months (aOR, 2.19), chronic obstructive pulmonary disease (aOR, 1.97), ischemic heart disease (aOR, 1.51), reduced mobility of 3 days or longer (aOR, 1.14), body mass index (aOR, 1.04), age (aOR, 1.02), recent trauma or surgery (aOR, 0.40), and risk for bleeding (aOR, 0.56). There is disagreement among the recommended models for predicting risk for VTE in patients hospitalized for medical conditions. The basis for emergency physicians' clinical judgment regarding thromboprophylaxis extends beyond risk scales to include multiple risk factors for VTE and bleeding.

Prevention of Venous Thromboembolism in Medical Patients with Thrombocytopenia or with Platelet Dysfunction: The Last 10 Years.

Current guideline recommendations for primary prophylaxis of venous thromboembolism (VTE) are based on randomized clinical trials that usually exclude subjects at a potentially high risk of bleeding complications. For this reason, no specific guideline is available for thromboprophylaxis in hospitalized patients with thrombocytopenia and/or platelet dysfunction. However, except in patients with absolute contraindications to anticoagulant drugs, antithrombotic prophylaxis should always be considered, for example, in hospitalized cancer patients with thrombocytopenia, especially in those with multiple VTE risk factors. Low platelet number, platelet dysfunction, and clotting abnormalities are also very common in patients with liver cirrhosis, but these patients have a high incidence of portal venous thrombosis, implying that cirrhotic coagulopathy does not fully protect against thrombosis. These patients may benefit from antithrombotic prophylaxis during hospitalization. Patients hospitalized for COVID-19 need prophylaxis, but frequently experience thrombocytopenia or coagulopathy. In patients with antiphospholipid antibodies, a high thrombotic risk is usually present, even in the presence of thrombocytopenia. VTE prophylaxis in high-risk conditions is thus suggested in these patients. At variance with severe thrombocytopenia (< 50,000/mm3), mild/moderate thrombocytopenia (≥ 50,000/mm3) should not interfere with VTE prevention decisions. In patients with severe thrombocytopenia, pharmacological prophylaxis should be considered on an individual basis. Aspirin is not as effective as heparins in lowering the risk of VTE. Studies in patients with ischemic stroke demonstrated that thromboprophylaxis with heparins is safe in these patients also during antiplatelet treatment. The use of direct oral anticoagulants in the prophylaxis of VTE in internal medicine patients has been recently evaluated, but no specific recommendation exists for patients with thrombocytopenia. The need for VTE prophylaxis in patients on chronic treatment with antiplatelet agents should be evaluated after assessing the individual risk of bleeding complications. Finally, the selection of patients who require post-discharge pharmacological prophylaxis remains debated. New molecules currently under development (such as the inhibitors of factor XI) may contribute to improve the risk/benefit ratio of VTE primary prevention in this setting of patients.

Venous thromboembolism in metastatic pancreatic cancer.

Pancreatic cancer (PC) carries a high risk of venous thromboembolism (VTE). Several risk assessment models (RAMs) predict benefit of thromboprophylaxis in solid tumors; however, none are verified in metastatic pancreatic cancer (mPC). A retrospective mPC cohort treated at an academic cancer center from 2010 to 2016 was investigated for VTE incidence (VTEmets). Multivariable regression analysis was used to assess multiple VTE risk factors. Overall survival (OS) was compared between mPC groups with and without VTE. Survival was analyzed using Kaplan-Meier survival plots and Cox proportional hazards regressions. 400 mPC patients (median age 66; 52% males) were included. 87% had performance status of ECOG 0-1; 70% had advanced stage at PC diagnosis. Incidence of VTEmets was 17.5%; median time of occurrence 3.48 months after mPC diagnosis. Survival analysis started at median VTE occurrence. Median OS was 10.5 months in VTEmets vs. 13.4 in non-VTE group. Only advanced stage (OR 3.7, p = .001) correlated with increased VTE risk. The results suggest mPC carries a significant VTE burden. VTE predicts poor outcomes from the point of median VTE occurrence. Advanced stage disease is the strongest risk factor. Future studies are needed to define risk stratification, survival benefit, and choice of thromboprophylaxis.

Chemoprophylaxis and Management of Venous Thromboembolism in Microvascular Surgery.

This review aims to highlight the common pharmacological and nonpharmacological interventions utilized for thromboprophylaxis as well as flap salvage in microsurgery. A literature review was conducted in PubMed/National Center for Biotechnology Information, Scopus, Web of Science, and MEDLINE databases. Articles with a focus on thromboprophylaxis in microsurgical procedures spanning head and neck surgery, breast and extremity microvascular reconstruction, deep venous thrombosis/pulmonary embolus in microvascular surgery, and flap thrombosis and salvage were included in this review. The majority of available evidence supports mechanical venous thromboembolism (VTE) prophylaxis in all patients undergoing microsurgery given the presence of multiple risk factors for VTE within this particular patient population. Based on the literature review, addition of VTE chemoprophylactic agents is beneficial and an algorithmic approach to thromboprophylaxis in microsurgery patients and management of patients with thrombosis based on literature review and senior authors' experience is recommended and outlined.

Exceedingly High Rate of Venous Thromboembolism after Laparoscopic Splenectomy Warrants a Chemoprevention Guideline

INTRODUCTION: Venous thromboembolism (VTE) after elective laparoscopic splenectomy (LS) historically ranges from 0.8% to 3%, which is higher than other types of elective noncardiac procedures. These patients often have multiple risk factors for VTE. However, no guideline exists to aid surgeons in minimizing VTE. The purpose of this study is to define the associated risk and rate of VTE after LS. METHODS: The American College of Surgeons NSQIP database was queried from 2005 to 2020. Patients were identified based on the CPT code 38120. Patients were further excluded if they were coded as emergent or being transported to the hospital from any location other than home. Analysis of the data was performed with RStudio and Microsoft Excel. RESULTS: A total of 5,176 patients underwent LS with a VTE rate of 3.6% and average Caprini score of 4. Among these, 67% had surgical indication or a postoperative diagnosis that confers increased risk of VTE, such as active malignancy or autoimmune disease. 100% of patients had full data available for all relevant outcomes except for postoperative diagnosis, in which 97% of patients had this information recorded (Table),TableCONCLUSION: LS patients are very high risk for VTE, even more so than patients undergoing bariatric or total joint surgery. These patients should be strongly considered for both preoperative and postoperative VTE chemoprophylaxis. Additional research should be performed investigating the role of prolonged postoperative VTE chemoprophylaxis after discharge.

Incidence of venous thromboembolic events not related to vascular catheters in a prospective cohort of critically ill children

The risk for venous thromboembolism (VTE) is considered to be low in the general paediatric intensive care unit (PICU) population, and pharmacological thromboprophylaxis is not routinely used. PICU patients considered at high-risk of VTE could possibly benefit from pharmacological thromboprophylaxis, but the incidence of VTE in this group of patients is unclear. This was an observational, prospective study at a tertiary multi-disciplinary paediatric hospital. We used comprehensive ultrasonography screening for VTE in critically ill children with multiple risk factors for VTE. Patients admitted to PICU ≥ 72 h and with ≥ two risk factors for VTE were included. Patients receiving pharmacological thromboprophylaxis during their entire PICU stay were excluded. The primary outcome of the study was VTEs not related to the use of a CVC. Ultrasonography screening of the great veins was performed at PICU discharge. Seventy patients with median (interquartile range) 3 (2–4) risk factors for VTE were evaluated. Median age was 0.3 years (0.03–4.3) and median PICU length of stay 9 days (5–17). Regarding the primary outcome, no symptomatic VTEs occurred and no asymptomatic VTEs were found on ultrasonography screening, resulting in an incidence of VTEs not related to a vascular catheter of 0% (95% CI: 0–5.1%).Conclusion: Our results indicate that VTEs not related to a vascular catheter are a rare event even in a selected group of severely ill small children considered to be at high risk of VTE.What is Known:• Children in the PICU often have several risk factors for venous thromboembolism (VTE).• The incidence of VTE in PICU patients is highly uncertain, and there are no evidence-based guidelines regarding VTE prophylaxis.What is New:• This study found an incidence of VTEs not related to a vascular catheter of 0% (95% CI: 0–5.1%).• This indicates that such VTE events are rare even in PICU patients with multiple risk factors for VTE.

Provider Practices Regarding Prophylactic Anticoagulation in Children with Leukemia

Venous thromboembolism (VTE) is a known complication in children with leukemia, with prevalence in acute lymphoblastic leukemia (ALL) reported as high as 37% (Mitchell, et al, Cancer, 2003). Indwelling catheters, hyperviscosity, mediastinal masses, and medications such as asparaginase, can all contribute to increased VTE risk. In addition to national interest in preventing VTE in hospitalized children, decreasing risk of VTE in children with cancer is of great importance to pediatric hematologist/oncologists. The International Society of Hemostasis and Thrombosis released a guidance statement (Tullius, et al, JTH, 2017) that suggested considering thromboprophylaxis on a case-by-case basis for children with cancer and multiple VTE risk factors, and suggested discontinuing anticoagulant prophylaxis when predisposing conditions resolve. Children with leukemia certainly may have multiple risk factors and therefore deserve consideration for prophylaxis. The Children's Oncology Group is currently conducting a clinical trial studying thromboprophylaxis during induction for ALL. Given the importance of reducing VTE and the interest in thromboprophylaxis, we sought to assess practitioners' practices regarding thromboprophylaxis in children with leukemia. We performed a cross sectional, anonymous survey of pediatric members of VENUS (the VTE Network of the Hemostasis and Thrombosis Research Society) and ASH (the American Society of Hematology) using Qualtrics, a secure online survey tool. Responses were excluded if physicians answered no to either of 2 screening questions (related to clinical practice and board certification/eligibility), or if no questions were answered after screening. A gift card incentive was offered anonymously. Institutional IRBs approved this study. 870 surveys were distributed, with a response rate of 17.7%; after exclusions, a total of 142 surveys were included. Demographics were well balanced regarding size of program and years in practice. When asked about which anticoagulant agents may be used for thromboprophylaxis (n=36), 92% of those responding reported using enoxaparin (Table 1). In addition, 36% use Apixaban and 14% use Rivaroxaban. When asked if they ever provide primary VTE prophylaxis to children with leukemia (n=127), 71% said no, while 29% answered yes (Table 1). When asked in what scenarios primary prophylaxis was used, the most common answer was in leukemia patients with a known inherited thrombophilia (57%). Also common were children with mediastinal masses with vessel compression, and children enrolled on the COG prophylaxis study. Some additional scenarios offered were AYA patients, and those with additional risk factors, such as obesity and immobility. When asked about duration of primary prophylaxis (n=36), the most common times for discontinuing therapy were resolution of mediastinal mass and/or vessel compression (58%), end of all asparaginase therapy (50%), and until the central line is removed (42%). A smaller number of physicians (22%) would consider continuing anticoagulant prophylaxis until the end of all cancer chemotherapy. When questioned about secondary prophylaxis following VTE (n=127), 8% of respondents never provide post-VTE prophylaxis, 11% always give post-VTE prophylaxis, and 81% used post-VTE prophylaxis in certain cases (Table 1.) The most common stopping point for secondary prophylaxis (n=116) was after central line removal (55%), followed by completion of all asparaginase therapy (41%). Our study is limited by a low response rate. Due to technical issues, we had missing data for many questions and could not obtain free-text answers for some of the prophylaxis questions, limiting full data acquisition. Despite these issues, our results provide some insights into current practices of pediatric hematologist/oncologists. This study shows that many physicians are not utilizing primary anticoagulant prophylaxis in their pediatric leukemia patients, despite the high-risk nature of these patients, possibly trying to balance bleeding risk due to thrombocytopenia. Duration of anticoagulant therapy varies, and it is likely that there are no clear definitions regarding resolution of predisposing factors. Given their unique set of risk factors, and the potential morbidity associated with VTE, further study of VTE prophylaxis is essential for development of pediatric leukemia-specific guidelines. Disclosures Cooley: off-label: Other: drug use. Acharya:Bayer Pharmaceuticals, LLC: Research Funding; Novonordisk: Membership on an entity's Board of Directors or advisory committees; BioProducts Laboratory: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: We surveyed physicians on which anticoagulants they use in their pediatric leukemia patients and the majority of drugs offered as answer choices are technically off-label.

Venous Thromboembolic Prophylaxis Following Treatment Initiation for Multiple Myeloma

Abstract INTRODUCTION: Multiple myeloma (MM) induces a hypercoagulable state with increased risk of venous thromboembolism (VTE) due to higher blood viscosity, circulating immunoglobin, inflammatory cytokines, procoagulant monoclonal protein and cytotoxic therapies. Thromboprophylaxis is typically indicated for immunomodulator-based treatment or if a patient has multiple VTE risk factors, though evidence on the patterns and effectiveness of antithrombotic medications in this setting is lacking. Our objective was to describe VTE prophylaxis interventions in patients with MM in a large commercially-insured U.S. population. METHODS: We performed a retrospective cohort study of patients with incident MM initiating first-line treatment between 2009 and 2015 using medical and pharmacy administrative claims data from the Truven Health MarketScan Research Database. Patients were required to have continuous enrollment for at least 12 months prior to MM diagnosis and 6 months following treatment initiation (unless died). Information on MM treatments including immunomodulatory drugs (IMiDs: thalidomide, lenalidomide, pomalidomide), proteasome inhibitors (PIs: bortezomib) and other oral and intravenous chemotherapy agents was collected. Baseline characteristics related to risk of VTE were documented, including medical conditions, procedure-related risk factors, other medications associated with increased VTE risk and MM-treatment related risk factors defined by the International Myeloma Working Group. Medications used for VTE prophylaxis following MM treatment initiation (and prior to the occurrence of a subsequent VTE event) included antiplatelet agents, low molecular weight heparin (LMWH), warfarin and direct oral anticoagulants (DOAC). We used multivariable logistic and polytomous regression models to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI) associated with receipt of VTE prophylaxis and specific antithrombotic medications used respectively. RESULTS: Among 7405 MM patients, the mean age was 64.9 years (standard deviation: 11.6), 43% were female, and more than half of patients received IMiD-based treatment (52%). Overall, 20% of patients in the cohort received VTE prophylaxis with any agent [antiplatelet agent (5%), LMWH (6%), warfarin (7%) and DOAC (2%)]. Patients treated with IMiDs had fewer VTE risk factors at baseline compared with MM patients receiving non-IMiD based treatment (2 or more risk factors: 24% vs. 38%, p&lt;0.01); however, a higher proportion of patients receiving IMiDs received VTE prophylaxis with any agent (25% vs. 14%, p&lt;0.01). The median number of days receiving VTE prophylaxis was between 92 and 109 days for antiplatelet, warfarin and DOAC therapies and 23 days for LMWH. Having 2 or more VTE risk factors at baseline was associated with higher odds of receiving VTE prophylaxis (OR 1.58, 95% CI 1.40-1.79). MM treatments associated with receipt of any VTE prophylaxis included thalidomide (OR 3.17, 95% CI 2.51-4.00), lenalidomide (OR 2.14, 95% CI 1.87-2.46) and doxorubicin-including chemotherapy (OR 3.48, 95% CI 2.36-5.13) but not pomalidomide (OR 0.97, 95% CI 0.55-1.70) or bortezomib (OR 0.91, 95% CI 0.79-1.05). VTE prophylaxis with antiplatelet agents was associated with history of atrial fibrillation (OR 2.01, 95% CI 1.50-2.70) and recent central venous catheter use (OR 1.58, 95% CI 1.25-2.00); whereas prophylaxis with LMWH, warfarin or DOAC was associated with history of a VTE event in the prior 12 months (OR 3.59, 95% CI 2.74-4.69), chronic kidney disease (OR 4.48, 95% CI 3.67-5.47), recent hip fracture (OR 1.68, 95% CI 1.12-2.52) and recent hospitalization (OR 1.27, 95% CI 1.08-1.49). CONCLUSIONS: VTE prophylaxis is generally recommended with the presence of 2 or more VTE risk factors or when initiating IMiD therapy in patients with multiple myeloma. In our cohort, half of newly diagnosed MM patients initiated IMiD-based first-line therapy; of which; one in four IMiD initiators also received prophylaxis with antithrombotic or anticoagulant medications. Comprehensive evidence on the comparative effectiveness of VTE prophylaxis strategies in multiple myeloma is needed to guide prevention of this serious adverse outcome. Disclosures Patel: Celgene: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Janssen: Honoraria.

The identification of risk factors for venous thromboembolism in gastrointestinal oncologic surgery

BackgroundThe aim of this study was to examine the incidence and factors associated with occurrence of venous thromboembolism (VTE) in patients undergoing major gastrointestinal (GI) surgery for malignancy. MethodsThe American College of Surgeon's National Surgical Quality Improvement Program, Participant User File database was queried from 2005 to 2012 to study major GI operations performed for cancer. Predictors of VTE and their relation to survival were studied. ResultsIn 79,300 patients, the incidence of deep venous thrombosis was 1.7%, and pulmonary embolism was 0.9% during the 30-d postoperative period. The highest rate of VTE occurred after esophagectomy (5.9%) followed by pancreatectomy (3.2%), hepatectomy (3.2%), gastrectomy (2.5%), enterectomy (2.3%), colectomy, and proctectomy (2.0%). On multivariate analysis, disseminated cancer, age ≥ 80 y, body mass index > 35 kg/m2, functional status, post operative sepsis, pulmonary dysfunction, and longer operative time were associated with occurrence of VTE. Occurrence of VTE was associated with mortality on multivariate analysis (odds ratio 2.4, 95% confidence interval 2.0-3.0, P < 0.001). ConclusionsAbsolute incidence of VTE after major GI surgery is low but is associated with significant mortality and postoperative complications. Disseminated cancer, post operative sepsis, longer operative time, and increased body mass index >35 kg/m2 further increased the risk of VTE in patients undergoing surgery for malignancy. Surveillance strategies should be implemented for those cancer patients who have multiple risk factors for VTE.

Risk Factors for Venous Thromboembolism following Thoracolumbar Surgery: Analysis of 43,777 Patients from the American College of Surgeons National Surgical Quality Improvement Program 2005 to 2012.

Study Design Retrospective clinical study of a prospectively collected, national database. Objective Determine the 30-day incidence, timing, and risk factors for venous thromboembolism (VTE) following thoracolumbar spine surgery. Methods The American College of Surgeons National Surgical Quality Improvement Program Participant Use File identified 43,777 patients who underwent thoracolumbar surgery from 2005 to 2012. Multiple patient characteristics were identified. The incidence and timing (in days) of deep vein thrombosis (DVT) and pulmonary embolus (PE) were determined. Multivariable regression analysis was performed to identify significant risk factors. Results Of the 43,777 patients identified as having had thoracolumbar surgery, 202 cases of PE (0.5%) and 311 cases of DVT (0.7%) were identified. VTE rates were highest in patients undergoing corpectomy, with a 1.7% PE rate and a 3.8% DVT rate. Independent risk factors for VTE included length of stay (LOS) ≥ 6 days (odds ratio [OR] 4.07), disseminated cancer (OR 1.77), white blood cell count > 12 (OR 1.76), paraplegia (OR 1.75), albumin < 3 (OR 1.73), American Society of Anesthesiologists class 4 or greater (OR 1.54), body mass index > 40 (OR 1.49), and operative time > 193 minutes (OR 1.43). LOS < 3 days was protective (OR 0.427). Conclusions We report an overall 30-day PE rate of 0.5% and DVT rate of 0.7% following thoracolumbar spine surgery. Patients undergoing corpectomy were at highest risk for VTE. Multiple VTE risk factors were identified. Further studies are needed to develop algorithms to stratify VTE risk and direct prophylaxis accordingly.

Commentary on: Doppler ultrasound imaging of plastic surgery patients for deep venous thrombosis detection: a prospective controlled study.

The author of the preceding article has done a creditable job of presenting a prospective cohort study of Doppler ultrasound screening for lower extremity deep venous thrombosis (DVT) of patients undergoing cosmetic outpatient surgery procedures.1 Not surprisingly, no cases of postoperative DVT were noted among the postoperative patients. While we may wonder about the cost implications of universal Doppler screening before and after cosmetic surgery, the investigator demonstrates that the modality was feasible in their practice, albeit it was offered free of charge. However, more troubling are a number of other assertions by the author that gloss over important issues surrounding postoperative venous thromboembolism (VTE) risk assessment and prevention in plastic surgery patients. Although they are rare events, VTEs do occur after outpatient operations. In an analysis of 259,231 outpatient surgeries over a 5-year period from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database, Pannucci and colleagues2 calculated an overall VTE rate of 0.15%, including cases of DVT and pulmonary embolus (PE). The investigators identified multiple risk factors for VTE, including age, body mass index (BMI), and length of surgery. A weighted risk index was calculated based on these factors. Using this index, a sub-population of high-risk patients was noted to have a 30-day VTE rate of 1.18%. While we would all like to believe that postoperative VTE poses little or no risk to our outpatients, the “never seen one” rationale does not justify ignoring preoperative VTE risk assessment or, in high-risk cases, failure to consider VTE prophylaxis. In the current article, the author asserts that “it remains impossible to accurately predict which patients will develop a postoperative deep venous thrombosis.” He goes on to dismiss the Caprini Risk Assessment Model (RAM) as lacking validity and maintains …

Inferior vena cava filters for prevention of venous thromboembolism in obese patients undergoing bariatric surgery: a systematic review.

The use of inferior vena cava (IVC) filters for prevention of venous thromboembolism (VTE) in bariatric surgery is a contentious issue. We aim to review the evidence for the use of IVC filters in bariatric surgical patients, describe trends in practice, and discuss challenges in developing evidence-based guidelines. The incidence of VTE in modern bariatric procedures with traditional methods of thromboprophylaxis, such as sequential calf compression devices and perioperative low molecular weight heparin, is approximately 2%. A systematic review of the literature was conducted according to PRISMA guidelines. We searched Medline up until July 2013 with the terms "bariatric filter" and "gastric bypass filter." Two investigators independently screened search results according to an agreed list of eligibility criteria. Eighteen studies were included. There were no randomized controlled trials. Data from controlled cohort studies suggest that those who undergo IVC filter insertion preoperatively may be at higher risk of developing deep vein thrombosis (DVT) and pulmonary embolism (PE). A small cohort of patients with multiple risk factors for VTE benefitted from reduced PE-related mortality after preoperative IVC filter insertion. Data from 12 case series reporting VTE outcomes from a total of 497 patients who underwent preoperative IVC filter insertion demonstrated DVT rates of 0% to 20.8% and PE rates ranging from 0% to 6.4%. Published data reporting the safety and efficacy of IVC filter use in bariatric surgical patients is highly heterogeneous. There is no evidence to suggest that the potential benefits of IVC filters outweigh the significant risks of therapy.

Safety of Prophylactic Anticoagulation at a Pediatric Hospital

The importance of preventing venous thromboembolism (VTE) in hospitalized adults is well recognized. We recently developed and published our institutional guidelines for the prevention of VTE in high-risk hospitalized patients in a pediatric hospital. The objective of this prospective observational study was to evaluate the safety of anticoagulation after these guidelines were instituted. The primary outcome was major bleeding and secondary outcomes included minor bleeding and VTE. Eighty-nine patients were enrolled, with a mean age of 16.6 years. The most common risk factors for VTE were impaired mobility, lower extremity orthopedic surgery, and obesity. The majority of patients (63%) had 3 or more risk factors. There were 2 major bleeding events, and minor bleeding occurred in 5 patients, all in patients who had undergone major orthopedic surgery. Therefore the risk of major bleeding in orthopedic surgery patients was 4% (2/51), and 0% (0/38) in the remaining patients. No patient developed a non-catheter-related VTE, which was the primary intent of our guidelines. Although there remains much work to be done to optimize VTE strategies in pediatric patients, this study provides information regarding the risks of VTE prophylaxis using a pragmatic approach in hospitalized patients with multiple risk factors for VTE. More studies are needed to better define the risk:benefit ratio in this population.

Contraception-Related Venous Thromboembolism in a Pediatric Institution

Study ObjectiveTo define the thrombotic risk factors of young women presenting to a children's hospital with hormonal contraception-related venous thromboembolism (VTE). We hypothesized that the majority of patients would have additional risk factors for VTE. DesignClinical and laboratory data obtained retrospectively from electronic medical records concerning history of presentation, body mass index (BMI), medical and family history, medication profile, and relevant laboratory studies. SettingNationwide Children's Hospital in Columbus, Ohio, November 2008-May 2012. ParticipantsTwenty-six female patients, age 12-21 years, admitted for hormonal contraception-related VTE. ResultsFifty-seven VTE cases were reviewed, and 26 were identified as contraception-related VTE. 96% of patients had at least 1 additional risk factor for VTE, and 42% of patients had 2 or more additional risk factors. 50% patients had a BMI ≥25 kg/m2. 35% of patients had a positive family history of VTE in a first or second-degree relative. 27% of patients were subsequently diagnosed with an inherited thrombophilia, 5 of whom had a positive family history. ConclusionIn a small population of adolescents presenting to a children's hospital with contraception-related VTE, the majority of patients had multiple risk factors for VTE. Obesity was the most common additional risk factor (50%) identified in our study population. More research is needed regarding the impact of obesity on contraception-related VTE in young women, and whether the presence of obesity should influence thrombophilia screening practices prior to prescribing contraception.

Prevention of Venous Thromboembolism in Medical Patients with Thrombocytopenia or with Platelet Dysfunction: A Review of the Literature

Current guidelines for venous thromboembolism (VTE) primary prophylaxis are based on randomized clinical trials that exclude subjects at a potentially high bleeding risk. Thus no specific recommendation/algorithm for pharmacological prophylaxis in patients with thrombocytopenia and/or platelet dysfunction is available. Because at least 25% of subjects admitted to medical departments exhibit these conditions, information on this subject is provided here to optimize their VTE prophylaxis. Low platelet number/function and clotting abnormalities are common in patients with liver cirrhosis. However, these patients have a high incidence of portal and idiopathic venous thromboses, implying that cirrhotic coagulopathy does not protect against thrombosis. At variance with severe thrombocytopenia (< 50,000/μL), mild/moderate thrombocytopenia (> 50,000/μL) should not interfere with VTE prevention decisions. In severe thrombocytopenia, prophylaxis should be considered on an individual basis, however. In patients with antiphospholipid antibodies and thrombocytopenia, a thrombotic tendency is usually associated rather than a bleeding risk. VTE prophylaxis in high-risk conditions is thus suggested in these patients. Except in cases with contraindications to anticoagulation, antithrombotic prophylaxis should be always considered in hospitalized cancer patients with thrombocytopenia, especially in those with hematologic malignancies and multiple VTE risk factors. Aspirin treatment is not as effective as heparins in lowering the risk of VTE. Studies in stroke suggest that thromboprophylaxis with heparins is safe in patients with ischemic stroke undergoing aspirin treatment. The need for VTE prophylaxis in patients on chronic treatment with aspirin and/or clopidogrel should be evaluated after assessing the individual risk-benefit ratio.

Characteristics of Patients Experiencing Thromboembolic Events during Treatment for Multiple Myeloma: Aspirin May Not Be Adequate Thromboprophylaxis in Patients with Multiple Risk Factors.

Patients (pts) with multiple myeloma (MM) have a high risk of venous thromboembolism (VTE) due to features of the disease or treatment, such as thalidomide (Thal), Lenalidomide (Len), steroids, and certain chemotherapeutic agents. Based on evidence showing the benefit of VTE pharmacological prophylaxis, it is recommended that VTE prophylaxis be prescribed for pts receiving these agents. However, the impact of these guidelines on patient outcomes is less well studied. The study aim was to evaluate the characteristics of MM pts with VTE in a comprehensive cancer center. This retrospective analysis included all MM pts diagnosed with deep vein thrombosis (DVT) or pulmonary embolism (PE) between July and December 2006. Medical records were examined for risk factors such as central venous catheter (CVC), functional status, history of VTE, MM treatment, and use of VTE prophylaxis. Twenty four VTE events (19 DVT, 3 PE, 2 DVT and PE concurrently) occurred in 21 pts, of whom 18 had a single event and 3 had 2 each. During 14 of the 24 events (58.3%), pts were receiving agents known to increase the risk of VTE, including 12 receiving Thal or Len + steroids. During 15 events, pts were anemic (Hgb ≤ 11gms/dL); 4 of these were on erythropoietic agents. Only 1 event occurred while the patient was receiving LMWH. Ten events occurred in pts on aspirin (3 at 81mg, 7 at 325mg). Fourteen events (58.3%) occurred in pts not receiving VTE prophylaxis; 7 occurred when platelet counts were between 18–76 × 103/mm3. The other 7 events were in pts on various myeloma regimens including 2 on melphalan/stem cell transplant and one each on bortezomib, Thal, dexamethasone (Dex), denosumab, and cyclophosphamide/Dex. None of the 3 with recurrent VTE were on anticoagulation at time of recurrence. All 3 were admitted and anticoagulation was held for thrombocytopenia (2) or renal failure (1). Of the 7 events occurring during treatment with Len + steroids occurred while on aspirin; 6 had additional risk factors. One was heterozygous for Factor V Leiden mutation; one had surgery prior to the event; four had neuropathy with 3 in wheelchairs. Of the nine pts with an upper extremity DVT, all but 2 were associated with a CVC (77.7%). Lower extremity DVT commonly occurred in pts with impaired mobility due to neuropathy or deconditioning (38%). In spite of increased awareness of the risk of thrombosis, VTE remains a significant cause of morbidity in MM pts. In this study, CVC, poor mobility, and treatment with Len/Dex were the most common risk factors. VTE events occurred during treatment with Len/Dex despite the concurrent use of aspirin. This suggests that aspirin alone may not be adequate as VTE prophylaxis in pts with MM and multiple risk factors for VTE. The role of aspirin and other interventions to prevent VTE deserve further investigation to optimize thromboprophylaxis in this population.

Approaches to risk-stratifying cancer patients for venous thromboembolism

Cancer patients are clearly at increased risk for venous thromboembolism (VTE). However, the risk is not equal for all cancer patients or even in the same patient over the course of the natural history of cancer. VTE prophylaxis has been shown to be beneficial in certain high-risk populations such as post-surgical or hospitalized cancer patients but data in the ambulatory setting are conflicting. A majority of solid tumor patients are currently treated in the ambulatory setting and studying risk factors for VTE and their interaction is essential to identifying a population of ambulatory cancer patients that could benefit from prophylaxis. In this review, we evaluate the literature on risk factors for cancer-associated VTE and discuss data from a large observational study of cancer patients receiving chemotherapy which has revealed novel risk factors for chemotherapy-associated VTE. Finally, we discuss model-based approaches to risk-stratifying cancer patients that incorporate the known multiple risk factors for VTE and can help identify high-risk subgroups in the cancer population.

Prospective study of fibrinolytic markers and venous thromboembolism

Prior research has conflicted on whether increased levels of plasma fibrinolytic factors may identify patients at risk of venous thromboembolism (VTE). We therefore performed a nested case–control study of VTE within two prospective population-based studies. In 308 participants who developed VTE and 640 controls, we measured PAI-1 antigen, tPA/PAI-1 complex, plasmin-α 2-antiplasmin (PAP), and the PAI-1 −675 4G/5G promoter polymorphism on pre-event blood samples. There was no overall association between any of these fibrinolytic variables and VTE, after adjustment for age or for multiple VTE risk factors. There was weak evidence for an interaction of PAP with elevated factor VIIIc and elevated D-dimer in augmenting VTE risk. We conclude that, for the most part, these fibrinolytic markers do not identify healthy subjects at risk for VTE.