Project description:BackgroundUnprovoked venous thromboembolism (VTE) is rare in pediatrics. Current recommendations for anticoagulation duration after unprovoked VTE differ for pediatric and adult populations.ObjectivesThis single-center, retrospective cohort study aimed to determine the incidence rate of recurrent VTE in children and adolescents with unprovoked VTE, evaluate the potential risk factors for recurrence, and describe the anticoagulation regimens and bleeding in this population.MethodsChildren with an index, unprovoked VTE at the age of 1 to <21 years between 2003 and 2021 were included. The time to recurrent VTE and anticoagulation duration were summarized using Kaplan-Meier estimators. Clinical covariates were assessed for association with recurrence using stratified Kaplan-Meier curves and univariate Cox proportional hazards regression.ResultsEighty-five children met the inclusion criteria, and there were 26 recurrent events in 250 person-years of follow-up (incidence rate = 104 [95% CI, 71-153] per 1000 person-years). An age of ≥12 years at index VTE (hazard ratio [HR], 7.56; 95% CI, 1.60-35.83) and inherited thrombophilia (HR, 2.28; 95% CI, 1.05-4.95) were significantly associated with recurrent VTE. Female sex had a nonstatistically significant decreased hazard of recurrence (HR, 0.56; 95% CI, 0.25-1.27). Duration of anticoagulation was variable, with a median duration of 274 days (IQR, 101-2357) for outpatient therapeutic anticoagulation. Twelve of the 26 (46%) recurrent events occurred while anticoagulation was prescribed.ConclusionThe incidence rate of recurrent VTE in pediatric patients with a prior unprovoked VTE is high, particularly for adolescents and those with inherited thrombophilia. Therefore, future research should focus on the efficacy of prolonged anticoagulation for this population.
Project description:ObjectiveVenous thromboembolism (VTE) is reported to occur in up to 33% of patients undergoing major vascular surgery. Despite this high incidence, patients inconsistently receive timely VTE chemoprophylaxis. The true incidence of VTE among patients receiving delayed VTE chemoprophylaxis is unknown. We sought to identify the association of VTE chemoprophylaxis timing on VTE risk, postoperative transfusion rates, and 30-day mortality and morbidity in patients undergoing major open vascular surgery.MethodsPatients undergoing major open vascular surgery (open abdominal aortic aneurysm [oAAA] repair, aortofemoral bypass, and lower extremity infrainguinal bypass [LEB]) were identified using the Michigan Surgical Quality Collaborative (MSQC) between July 2012 and June 2015. The VTE rate was compared between patients receiving early versus delayed VTE chemoprophylaxis. VTE chemoprophylaxis delay was defined as therapy initiation more than 24 hours after surgery. The risk-adjusted association of the chemoprophylaxis timing and VTE development was determined using multivariable logistic regression. Blood transfusion rates, 30-day mortality, and postoperative complications were compared across groups.ResultsA total of 2421 patients underwent major open vascular surgery, including 196 oAAA repair, 259 aortofemoral bypass, and 1966 LEB. The overall incidence of 30-day VTE was 1.40%, ranging from 1.12% for LEB to 3.57% for oAAA repair. Among patients receiving early VTE chemoprophylaxis, the rate of VTE was 0.78% versus 2.26% among those with a delay in VTE chemoprophylaxis (P = .002). When accounting for the preoperative risk of VTE, delayed chemoprophylaxis was associated with a significantly higher risk of VTE (odds ratio, 2.38; 95% confidence interval, 1.12-5.06; P = .024). The early VTE chemoprophylaxis group was associated with a significantly decreased risk of bleeding compared with those with a delay (14.31% vs 18.90%; P = .002). Overall 30-day mortality and postoperative complications were similar with the exception of an associated higher rate of infectious complications in the delayed VTE chemoprophylaxis group, including superficial surgical site infection (6.00% vs 4.06%; P = .028), pneumonia (3.25% vs 1.85%; P = .028), urinary tract infection (2.95% vs 1.57%; P = .020), and severe sepsis (3.05% vs 1.71%; P = .029).ConclusionsAlthough patients undergoing major open vascular surgery have a low risk of VTE at baseline, there is a significantly greater risk of developing VTE among patients who have a delay in the administration of VTE chemoprophylaxis. Postoperative transfusion rates were significantly lower among patients receiving early chemoprophylaxis. There were no differences in the 30-day mortality and postoperative complications, except for infectious complications. Given these findings, surgeons should consider early chemoprophylaxis in the postoperative setting after major open vascular surgery without contraindication.
Project description:BackgroundModern diagnostic strategies for venous thromboembolism (VTE) incorporate pretest probability (PTP; prevalence) assessment. The ability of diagnostic tests to correctly identify or exclude VTE is influenced by VTE prevalence and test accuracy characteristics.ObjectiveThese evidence-based guidelines are intended to support patients, clinicians, and health care professionals in VTE diagnosis. Diagnostic strategies were evaluated for pulmonary embolism (PE), deep vein thrombosis (DVT) of the lower and upper extremity, and recurrent VTE.MethodsThe American Society of Hematology (ASH) formed a multidisciplinary panel including patient representatives. The McMaster University GRADE Centre completed systematic reviews up to 1 October 2017. The panel prioritized questions and outcomes and used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assess evidence and make recommendations. Test accuracy estimates and VTE population prevalence were used to model expected outcomes in diagnostic pathways. Where modeling was not feasible, management and accuracy studies were used to formulate recommendations.ResultsTen recommendations are presented, by PTP for patients with suspected PE and lower extremity DVT, and for recurrent VTE and upper extremity DVT.ConclusionsFor patients at low (unlikely) VTE risk, using D-dimer as the initial test reduces the need for diagnostic imaging. For patients at high (likely) VTE risk, imaging is warranted. For PE diagnosis, ventilation-perfusion scanning and computed tomography pulmonary angiography are the most validated tests, whereas lower or upper extremity DVT diagnosis uses ultrasonography. Research is needed on new diagnostic modalities and to validate clinical decision rules for patients with suspected recurrent VTE.
Project description:The association between inflammation, infection, and venous thrombosis has long been recognized; yet, only in the last decades have we begun to understand the mechanisms through which the immune and coagulation systems interact and reciprocally regulate one another. These interconnected networks mount an effective response to injury and pathogen invasion, but if unregulated can result in pathological thrombosis and organ damage. Neutrophils, monocytes, and platelets interact with each other and the endothelium in host defense and also play critical roles in the formation of venous thromboembolism. This knowledge has advanced our understanding of both human physiology and pathophysiology, as well as identified mechanisms of anticoagulant resistance and novel therapeutic targets for the prevention and treatment of thrombosis. In this review, we discuss the contributions of inflammation and infection to venous thromboembolism.
Project description:Venous thromboembolism, comprising deep vein thrombosis and pulmonary embolism, is a common disorder with at least 250 000 new events occurring each year in the United States alone. Treatment of venous thromboembolism includes anticoagulation, which is achieved initially with the use of a parenterally administered agent followed by a more prolonged course of treatment with an oral vitamin K antagonist. The duration of treatment depends on the clinical assessment of the benefit-to-risk ratio of prolonged anticoagulation versus the risk of recurrent events. In this review, we discuss some of the issues that we believe are among the most critical unanswered questions in the management of venous thromboembolism in the present era.
Project description:Venous thromboembolism (VTE; deep vein thrombosis and/or pulmonary embolism) is a well-established cause of morbidity and mortality in the medical and surgical patient populations. Clinical research in the prevention and treatment of VTE has been a dynamic field of study, with investigations into various treatment modalities ranging from mechanical prophylaxis to the direct oral anticoagulants. Aspirin has long been an inexpensive cornerstone of arterial vascular disease therapy, but its role in the primary or secondary prophylaxis of VTE has been debated. Risk-benefit tradeoffs between aspirin and anticoagulants have changed, in part due to advances in surgical technique and postoperative care, and in part due to the development of safe, easy-to-use oral anticoagulants. We review the proposed mechanisms in which aspirin may act on venous thrombosis, the evidence for aspirin use in the primary and secondary prophylaxis of VTE, and the risk of bleeding with aspirin as compared with anticoagulation.
Project description:BackgroundData on the association between acute infections and venous thromboembolism (VTE) are sparse. We examined whether various hospital-diagnosed infections or infections treated in the community increase the risk of VTE.MethodsWe conducted this population-based case-control study in Northern Denmark (population 1.8 million) using medical databases. We identified all patients with a first hospital-diagnosed VTE during the period 1999-2009 (n = 15 009). For each case, we selected 10 controls from the general population matched for age, gender and county of residence (n = 150 074). We identified all hospital-diagnosed infections and community prescriptions for antibiotics 1 year predating VTE. We used odds ratios from a conditional logistic regression model to estimate incidence rate ratios (IRRs) of VTE within different time intervals of the first year after infection, controlling for confounding.ResultsRespiratory tract, urinary tract, skin, intra-abdominal and bacteraemic infections diagnosed in hospital or treated in the community were associated with a greater than equal to twofold increased VTE risk. The association was strongest within the first 2 weeks after infection onset, gradually declining thereafter. Compared with individuals without infection during the year before VTE, the IRR for VTE within the first 3 months after infection was 12.5 (95% confidence interval (CI): 11.3-13.9) for patients with hospital-diagnosed infection and 4.0 (95% CI: 3.8-4.1) for patients treated with antibiotics in the community. Adjustment for VTE risk factors reduced these IRRs to 3.3 (95% CI: 2.9-3.8) and 2.6 (95% CI: 2.5-2.8), respectively. Similar associations were found for unprovoked VTE and for deep venous thrombosis and pulmonary embolism individually.ConclusionsInfections are a risk factor for VTE.
Project description:Recurrent venous thromboembolism (VTE) occurs infrequently following a provoked event but occurs in up to 30% of individuals following an initial unprovoked event. We studied 134 patients with VTE separated into 3 groups: (1) ‘low-risk’ patients had ≥1 provoked VTE; (2) ‘moderate-risk’ patients had no more than 1 unprovoked VTE; (3) ‘high-risk’ patients had ≥2 unprovoked VTE. 44 individuals with no history of VTE were enrolled as healthy controls. Consented individuals were enrolled at 4 medical centers in the US. Total RNA from whole blood was isolated and hybridized to Illumina HT-12 V4 Beadchips to assay whole genome expression. Using class prediction analysis, we distinguished high-risk patients from healthy controls with good receiver operating curve characteristics (AUC=0.88). We also distinguished high-risk from low-risk individuals, moderate-risk individuals from healthy controls, and low-risk individuals from healthy controls with AUC’s of 0.72, 0.77 and 0.72, respectively. Using differential expression analysis, we identified genes relevant to coagulation, immune response and vascular biology, such as SELP and CD46, which were differentially expressed in at least two comparisons. Neither approach distinguished the moderate-risk patients from the high-risk or low-risk groups. Gene expression profiles may provide insights into biological mechanisms associated with patients at risk for recurrent VTE. Prospective studies are needed to validate these findings.
Project description:Recurrent venous thromboembolism (VTE) occurs infrequently following a provoked event but occurs in up to 30% of individuals following an initial unprovoked event. We studied 134 patients with VTE separated into 3 groups: (1) âlow-riskâ patients had â¥1 provoked VTE; (2) âmoderate-riskâ patients had no more than 1 unprovoked VTE; (3) âhigh-riskâ patients had â¥2 unprovoked VTE. 44 individuals with no history of VTE were enrolled as healthy controls. Consented individuals were enrolled at 4 medical centers in the US. Total RNA from whole blood was isolated and hybridized to Illumina HT-12 V4 Beadchips to assay whole genome expression. Using class prediction analysis, we distinguished high-risk patients from healthy controls with good receiver operating curve characteristics (AUC=0.88). We also distinguished high-risk from low-risk individuals, moderate-risk individuals from healthy controls, and low-risk individuals from healthy controls with AUCâs of 0.72, 0.77 and 0.72, respectively. Using differential expression analysis, we identified genes relevant to coagulation, immune response and vascular biology, such as SELP and CD46, which were differentially expressed in at least two comparisons. Neither approach distinguished the moderate-risk patients from the high-risk or low-risk groups. Gene expression profiles may provide insights into biological mechanisms associated with patients at risk for recurrent VTE. Prospective studies are needed to validate these findings. This study includes a total of 218 samples/individuals (in 5 groups; APS, high-risk VTE, moderate-risk VTE, low-risk VTE and healthy-controls). Samples in which the percent of probes present was 15% or less (n=51) were excluded leaving 167 samples. The data for these 167 samples were normalized together. However, this record represents the 132 individual samples in the following groups; high-risk (n=40); moderate-risk (n=33); low-risk (n=34); and healthy controls (n=25). The 35 samples in APS group are represented in GSE48001.