Physician and patient perceptions of the route of administration of venous thromboembolism prophylaxis: results from an international survey

Introduction

Acceptability of a prescribed treatment regimen is crucial to its clinical success, and the route of drug administration can play an important role in determining acceptability. This international survey explored physician and patient perceptions of injectable and oral treatments, and how these perceptions affect acceptability of treatments. Findings are discussed in the context of patient acceptance of treatments for venous thromboembolism (VTE) management.

Methods

Physicians who are regular prescribers of VTE prophylaxis and a randomly selected patient population were recruited to take part in a questionnaire. Patients had to answer 23 questions and physicians gave their predictions of patients’ responses.

Results

In total, 568 physicians and 825 patients from 5 countries took part in the survey. More patients considered injectable treatments effective than considered oral treatments effective (87% versus 76%, respectively). This trend was well predicted by the physicians (98% and 61%, respectively). Additionally, 46% of patients would accept an injectable treatment program lasting > 2 months (rising to 67% for life-threatening diseases), a figure underestimated by physicians (11% and 46%, respectively). Overall, 73% of patients stated they would never miss an injection, where as 54% of physicians expected patients to miss one injection in a month of therapy.

Conclusions

Physicians who are regular prescribers of VTE prophylaxis underestimate patients’ ability to accept injectable treatments as an alternative to oral therapy. This survey suggests that injectable treatments may be an acceptable, and often preferred, option over oral administration of therapeutic and preventive medicines.     

Increased adhesive properties of neutrophils and inflammatory markers in venous thromboembolism patients with residual vein occlusion and high D-dimer levels

Background

Venous thromboembolism (VTE) develops via a multicellular process on the endothelial surface. Although widely recognized, the relationship between inflammation and thrombosis, this relationship has been mostly explored in clinical studies by measuring circulating levels of inflammatory cytokines. However, the role of inflammatory cells, such as neutrophils, in the pathogenesis of VTE is not clear in humans.

Aims

To evaluate the adhesive properties of neutrophils, erythrocytes and platelets in VTE patients and to correlate findings with inflammatory and hypercoagulability marker levels.

Methods

Study group consisted of twenty-nine VTE patients and controls matched according to age, gender and ethnic background. Adhesive properties of neutrophils, erythrocytes and platelets were determined using a static adhesion assay. Neutrophil adhesion molecules expressions were evaluated by flow cytometry. Inflammatory and hypercoagulability marker levels were evaluated by standard methods. Residual vein occlusion (RVO) was evaluated by Doppler ultrasound.

Results

No significant difference could be observed in platelet and erythrocyte adhesion between VTE patients and controls. Interestingly, VTE patients with high levels of D-dimer and RVO, demonstrated a significant increase in neutrophil adhesion, compared to controls and remaining patients. Inflammatory markers (IL-6, IL-8, TNF-α) were also significantly elevated in this subgroup, compared to other VTE patients. Adhesive properties of neutrophils correlated with IL-6 and D-dimer levels. Neutrophils adhesion molecules (CD11a, CD11b and CD18) were not altered in any of the groups.

Conclusion

These findings not only support the hypothesis of an association between inflammation and hypercoagulability, but more importantly, highlight the role of neutrophils in this process.     

Abnormally high prevalence of major components of the metabolic syndrome in subjects with early-onset idiopathic venous thromboembolism

Background

Although patients with idiopathic VTE are at higher than normal risk of asymptomatic atherosclerosis and of cardiovascular events, the impact of cardiovascular risk factors on VTE is poorly understood.

Objective

To assess the prevalence of the metabolic syndrome and of its components in patients with early-onset idiopathic VTE.

Methods

As many as 323 patients referred to our Thrombosis Ward for a recent (< 6-months) early-onset idiopathic venous thromboembolism (VTE), were compared with 868 gender- and age-matched subjects, in whom a history of venous thrombosis had been excluded, referred during the same period time to our Ward. All had undergone a clinical assessment for smoking habits and for the presence of the components of the metabolic syndrome.

Results

The metabolic syndrome was detected in 76/323 cases (23.5%) and in 81/868 controls (9.3%) (p < 0.001; OR:2.990; 95%C.I.:2.119-4.217). Smoking was more common in patients with idiopathic VTE than in controls. In addition to the metabolic syndrome as a whole, its major individual determinants (arterial hypertension, impaired fasting glucose plasma levels, abdominal obesity, hypertriglyceridemia, low HDL-cholesterol) significantly correlated with idiopathic VTE (p always < 0.05). The prevalence of thrombotic events was lower in females than in males (p = 0.000; OR:2.217), the latter being most often hypertensives, smokers, hypertriglyceridemics, carriers of a metabolic syndrome and of impaired fasting glucose than females. In a multivariate analysis, arterial hypertension, impaired fasting glucose, abdominal obesity, and hypercholesterolemia independently predicted idiopathic venous events.

Conclusions

Both metabolic syndrome as a whole and its major components individually considered, independently predict early-onset idiopathic VTE.     

The MASTER registry on venous thromboembolism: description of the study cohort

INTRODUCTION: Information on the epidemiology and long-term clinical outcome of venous thromboembolism (VTE) is mainly based on data from clinical trials and thus may be not representative of the full spectrum of VTE patients. The aim of this multicenter registry (MASTER) was to prospectively collect data on the epidemiology and long-term clinical outcome of VTE in an unselected cohort of patients. MATERIALS AND METHODS: In symptomatic patients with objectively confirmed acute VTE, information about clinical presentation, diagnostic methods, temporary and permanent risk factors, pre-event prophylaxis and treatment were captured by an electronic data network at the time of the index event. A 24-month follow-up is currently ongoing. RESULTS: From January 2002 to October 2004, 2119 patients were included in the MASTER registry in 25 Italian centers. At entry, the mean patient age was 59.3+/-18.1 years (range 18-99 years). 1541 patients (72.7%) were affected by deep vein thrombosis, 206 patients (9.7%) by pulmonary embolism and 372 patients (17.5%) by both deep vein thrombosis and pulmonary embolism. 676 patients (31.9%) received home-treatment. 899 patients (42.4%) had one or more temporary risk factors. 381 patients (18.0%) had a known cancer at the time of the index event and in 50 patients (2.4%) a new cancer was discovered at the time of the index event. 311 patients (14.7%) had a previous VTE. CONCLUSIONS: Following a real world approach, our registry describes the clinical presentation, risk factors, diagnosis and treatment procedures in a large cohort of unselected patients with VTE.     

Multicenter evaluation of the use of venous thromboembolism prophylaxis in acutely ill medical patients in Canada

BACKGROUND: Venous thromboembolism (VTE) prophylaxis in acutely ill medical patients has been shown to be safe and effective. Underutilization of this patient safety practice may result in avoidable mortality and morbidity. OBJECTIVES: We aimed to determine the proportion of hospitalized, acutely ill medical patients across Canada who were eligible to receive thromboprophylaxis and to evaluate the frequency, determinants and appropriateness of its use. PATIENTS/METHODS: CURVE is a national, multicenter chart audit of 29 Canadian hospitals. Data were collected on consecutive patients admitted to hospital for an acute medical illness during a defined 3-week study period. Information on demographic and clinical characteristics, risk factors for VTE and bleeding and use of VTE prophylaxis were recorded. The indications for and appropriateness of VTE prophylaxis were assessed using pre-specified criteria based on international consensus guidelines. Multivariable analyses were performed to identify determinants of prophylaxis use. RESULTS: Of the 4124 medical admissions screened over the study period, 1894 patients (46%) were eligible for study inclusion. The most common specified admitting diagnoses were severe infection (28%), COPD exacerbation or respiratory failure (12%), malignancy (9%) and congestive heart failure (8%). Thromboprophylaxis was indicated in 1702 (90%) study patients. Overall, some form of prophylaxis was administered to 23% of all patients. However, only 16% received appropriate thromboprophylaxis. Factors independently associated with greater use of prophylaxis included internist (vs. other specialty) as attending physician (OR 1.33, 95% confidence interval (CI) [1.03, 1.71]), university-associated (vs. community) hospital (OR 1.46, 95% CI [1.03, 2.07]), immobilization (per day) (OR 1.60, 95% CI [1.45, 1.77]), presence of >or=1 VTE risk factors (OR=1.78, 95% CI [1.35, 2.34]) and duration of hospitalization (per day of stay) (OR 1.05, 95% CI [1.03, 1.07]), however, use of prophylaxis was unacceptably low in all groups. Patients with cancer had a significantly reduced likelihood of receiving prophylaxis (OR=0.40, 95% CI [0.24, 0.68]). Presence of risk factors for bleeding did not influence the use or choice of prophylaxis. CONCLUSION: Most patients hospitalized for medical illness had indications for thromboprophylaxis, yet only 16% received appropriate prophylaxis. Efforts should be made to elucidate the reasons that underlie the very low rate of thromboprophylaxis in medical patients and to develop and test strategies to improve implementation of this patient safety practice.     

Circulating microparticles and risk of venous thromboembolism

Introduction

Circulating microparticles (MPs) may trigger a hypercoagulable state, leading to thrombotic complications. Data on their association with venous thromboembolism (VTE) are few and inconsistent.

Materials and methods

To investigate whether or not high levels of MPs are associated with an increased risk of VTE, we carried out a case-control study on 186 patients with a first, objectively diagnosed, episode of VTE and 418 healthy controls. Plasma levels of circulating MPs were measured by flow cytometry.

Results

Patients had higher median plasma levels of total MPs than controls (2184 per μL vs 1769 per μL, p < 0.0001). The risk of VTE increased progressively with increasing MPs, with a linear dose-response effect in the log odds. Individuals with MPs above the 90th percentile of the controls’ distribution (P₉₀ = 3263 per μL) had a 5-fold increased risk of VTE than those with MPs below the 10th percentile of controls (P₁₀ = 913 per μL), independently of sex, age, body mass index, thrombophilia, and plasma factor VIII levels [adjusted odds ratio: 5.30 (95%CI: 2.05-13.7)]. Using the 95th percentile of controls as cut-off (P₉₅ = 4120 per μL), the adjusted odds ratio was 2.20 (1.01-4.79) for individuals with MPs > P₉₅ compared with those having MPs ≤ P₉₅. After exclusion of individuals with antiphospholipid antibodies and hyperhomocysteinemia, the interaction between MPs > P₉₅ and thrombophilia increased the VTE risk from 1.63 (0.60-4.50) to 6.09 (1.03-36.1).

Conclusions

High levels of circulating MPs are a possible independent risk factor for VTE.     

Increased venous versus arterial thrombosis in the Factor V Leiden mouse

BACKGROUND: Deep vein thrombosis (DVT) occurs with high prevalence in association with the Factor V Leiden (R506Q) mutation, whereas most evidence suggests no correlation with clinical arterial thrombosis. OBJECTIVE: This study compared arterial to venous thrombosis in the mutationally analogous Factor V Leiden mouse. METHODS: Three separate vascular thrombosis models were evaluated in Fv(+/+) (wild-type), Fv(Q/+) (heterozygous) and Fv(Q/Q) (homozygous) Factor V Leiden mice. RESULTS: In a FeCl(3)-induced arterial thrombosis model, no statistical differences among the three genotypes were found in the time to thrombotic occlusion. In contrast, Fv(Q/+) and Fv(Q/Q) mice demonstrated larger femoral vein thrombi at 30 and 60 min compared to wild-types, with Fv(Q/Q) mice having statistically larger thrombi than both wild-type and Fv(Q/+) mice at 10 and 60 min and 24 h (p<0.05). In a model of thrombotic occlusion following arterial and venous anastomotic repair, both Fv(Q/+) and Fv(Q/Q) mice had higher rates of venous thrombosis than wild-types, but only Fv(Q/Q) homozygotes showed a statistically greater arterial occlusion rate than wild-types. CONCLUSION: The Factor V Leiden mouse demonstrated a greater propensity for venous vs. arterial thrombosis, paralleling clinical epidemiologic findings and supporting its use for research on deep vein thrombosis.     

Aneurysmal remodeling in the circle of Willis after carotid occlusion in an experimental model

Carotid occlusions are associated with de novo intracranial aneurysm formation in clinical case reports, but this phenomenon is not widely studied. We performed bilateral carotid ligation (n=9) in rabbits to simulate carotid occlusion, and sham surgery (n=3) for control. Upon euthanasia (n=3 at 5 days, n=6 at 6 months post ligation, and n=3 at 5 days after sham operation), vascular corrosion casts of the circle of Willis (CoW) were created. Using scanning electron microscopy, we quantified gross morphologic, macroscopic, and microscopic changes on the endocasts and compared findings with histologic data. At 5 days, CoW arteries of ligated animals increased caliber. The posterior communicating artery (PCom) increased length and tortuosity, and the ophthalmic artery (OA) origin presented preaneurysmal bulges. At 6 months, calibers were unchanged from 5 days, PComs further increased tortuosity while presenting segmental dilations, and the OA origin and basilar terminus presented preaneurysmal bulges. This exploratory study provides evidence that flow increase after carotid occlusion produces both compensatory arterial augmentation and pathologic remodeling such as tortuosity and saccular/fusiform aneurysm. Our findings may have considerable clinical implications, as these lesser-known consequences should be considered when managing patients with carotid artery disease or choosing carotid ligation as a therapeutic option.     

Antiphospholipid syndrome in patients with retinal venous occlusion

INTRODUCTION: We conducted a prospective study to determine the prevalence and the prognosis of antiphospholipid syndrome (APS) in patients with retinal venous occlusion (RVO). PATIENTS: Consecutive patients presenting with retinal vein occlusion were screened for vascular risk factors (diabetes mellitus, hypertension, hyperlipidemia) and for antiphospholipid antibodies (aPL): anticardiolipin (aCL), anti-beta2-glycoprotein I, and lupus anticoagulant. Patients with a serum sample positive for aPL returned at least 6 weeks later for a new screening to determine the prevalence of antiphospholipid syndrome. All patients were followed to determine the outcome. RESULTS: Sixty-eight patients presented with RVO, 16 had vascular risk factors for RVO. After two screenings for aPL, nine cases of antiphospholipid syndrome associated with RVO were diagnosed (13.2%). Eight patients were over age 50 years and none had a previous thrombotic event before RVO. All patients were treated with aspirin (160 mg/day). With a mean follow-up of 26.1+/-8.2 months (range, 16-36 months), there were no recurrences. CONCLUSION: Retinal venous occlusion is multifactorial in origin. In patients aged 50 years and older, without previous thrombotic event, aPL might not be predictive of recurrences and treatment with aspirin might be sufficient. In such patients, the routine screening for aPL does not appear warranted, but a randomized study should be conducted to really ascertain the pathogenic role of aPL and the most appropriate treatment in RVO.     

Hypercoagulability after trauma: Hemostatic changes and relationship to venous thromboembolism

Background

Major trauma induces a hypercoagulable state, which is frequently complicated by pathological thrombosis. However the sequential changes in coagulation markers and their relationship to clinical thrombosis have been poorly characterized.

Methods

We measured several markers of in vivo coagulation and fibrinolysis and their regulation serially for 2 weeks after multi-system trauma in a prospective cohort of patients who received no anticoagulant prophylaxis. Asymptomatic deep vein thrombosis (DVT) was assessed by routine bilateral venography between day 12 and 14. Clinically suspected DVT and pulmonary embolism (PE) were investigated in a standardized manner.

Results

Among the 135 cohort patients the overall venous thromboembolism (VTE) rate was 59%. Markers of thrombin generation were markedly increased within 24 hours of injury, remained persistently elevated for about 5 days and then decreased by day 14. No early compensatory increase in Tissue Factor Pathway Inhibitor (TFPI) or the complex of Factor Xa and TFPI (FXa-TFPI) was seen; FXa-TFPI remained depressed throughout the study. There was no inverse relationship demonstrated between markers of thrombin generation and thrombin regulation. Acquired APC resistance and hypofibrinolysis did not appear to be important contributors to hypercoagulability after trauma. None of the coagulation markers were independently predictive of VTE. Increasing age was the only significant, independent predictor of VTE.

Conclusion

Major trauma leads to significantly increased and persistent thrombin generation with disruption of its regulation. Coagulation markers do not appear to add independent predictive value in detecting VTE. Increasing age is the most important clinical predictor of VTE after trauma.     

Characterization of blood flow in the mouse dorsal spinal venous system before and after dorsal spinal vein occlusion

The availability of transgenic strains has made the laboratory mouse a popular model for the study of healthy and diseased state spinal cord (SC). Essential to identifying physiologic and pathologic events is an understanding of the microvascular network and flow patterns of the SC. Using 2-photon excited fluorescence (2PEF) microscopy we performed in vivo measurements of blood flow in the lower thoracic portion of the mouse dorsal spinal vein (dSV) and in the first upstream branches supplying it, denoted as dorsal ascending venules (dAVs). We found that the dSV had large radiculomedullary veins (RMVs) exiting the SC, and that flow in the dSV between pairs of RMVs was bidirectional. Volumetric flow increased in each direction away from the point of bifurcation. Flow in the upstream dAVs varied with diameter in a manner consistent with a constant distal pressure source. By performing ex vivo 2PEF microscopy of fluorescent-gel perfused tissue, we created a 3-D map of the dorsal spinal vasculature. From these data, we constructed a simple model that predicted changes in the flow of upstream branches after occlusion of the dSV in different locations. Using an atraumatic model of dSV occlusion, we confirmed the predictions of this model in vivo.     

Blood coagulation and fibrinolysis in fertile women with previous thromboembolic complications and effects of venous occlusion

Blood coagulation and fibrinolysis were studied at rest in 35 fertile women with previous thromboembolic complications (TE) (group P) and in 20 healthy fertile women (group C). The effect of venous occlusion was studied in 23 and 15 individuals in each group. Before and after venous occlusion fibrinopeptide A (FPA) levels were higher and plasminogen activator (PLA) activity lower in group P. During venous occlusion factor VIII:C and fibrinogen increased in the stased blood in group P. FPA, factor VIIIR:Ag, antithrombin III (AT), PLA, ₂-antiplasmin and urokinase inhibitors increased in both groups. Decreased PLA activity was noted about twice as often among smokers as among non-smokers. No single variable suitable for screening was found but a combination of FPA, fibrinogen, factor VIII, AT and PLA maybe useful in diagnosing increased risk for TE. In some patients and a single control increased levels of inhibitors of the fibrinolytic system were found.     

Sturge-Weber syndrome: deep venous occlusion and the radiologic spectrum

Sturge-Weber syndrome is a neurocutaneous syndrome with a facial port-wine nevus and neurologic features, typically including seizures and hemiparesis. Glaucoma may also occur. MRI features include leptomeningeal angiomatosis, cortical and pial calcifications, and angiomatous change of the choroid plexus. We reviewed a subset of patients with Sturge-Weber syndrome with the rare finding of deep venous occlusion, and present such a case, unusual by comparison to previously reported cases of Sturge-Weber syndrome with deep venous occlusion. Six previously reported cases were reviewed. All cases presented with seizures; five of six had evidence of leptomeningeal angiomatosis; half had cerebral hemiatrophy. This report presents a unique case lacking clinical seizures, but with a port-wine stain and congenital glaucoma. This patient lacked the radiologic findings of leptomeningeal angiomatosis and hemicerebral atrophy, but demonstrated deep venous occlusion with frontal venous collaterals. There is a wide spectrum of findings in Sturge-Weber syndrome. The lack of seizures and angiomatosis in this case are likely "true-true" and related. The case illustrates the unusual finding of deep venous occlusion in Sturge-Weber syndrome occurring without leptomeningeal angiomatosis. Additionally, it demonstrates that although the initial evaluation is normal, patients may later manifest clinical characteristics of Sturge-Weber syndrome.     

Rivaroxaban attenuates leukocyte adhesion in the microvasculature and thrombus formation in an experimental mouse model of type 2 diabetes mellitus

Introduction

Thrombosis is a major complication in diabetes mellitus. Since Factor Xa inhibitors are not only inhibit the coagulation system but also attenuate the leukocyte-endothelial interaction in acute inflammation models, the purpose of this study is to confirm the similar effects of rivaroxaban in a mouse model of type 2 diabetes mellitus.

Materials and Methods

In the treatment groups, either 5 or 10 mg/kg of rivaroxaban dissolved in DMSO was orally given to KK-A^y mice for 7 weeks (n = 6 in each group). KK-A^y mice fed by chow containing DMSO without rivaroxaban for 7 weeks were served for the control group (n = 6). Following clamping of the mesenteric vein for 20 minutes, intravital microscopic observation of the intestinal microcirculation and the measurement of bleeding time after the needle puncture were carried-out. In another series, the calculation for blood cell counts and the measurement of blood fluidity using micro channel array flow analyzer (MC-FAN) were performed.

Results

The initial event in the microvasculature is the leukocyte adhesion on endothelium. Then, the leukocytes make clusters and the platelets are involved in. These leukocyte-platelet conjugates aggregate and form thrombus. The leukocyte adherence and the microthrombus formation was significantly suppressed with the treatment of 10 mg/kg of rivaroxaban compared to the control group (P < 0.05). While, the bleeding time was significantly extended with the treatment with 10 mg/kg of rivaroxaban (P < 0.01). The blood fluidity was maintained best with the treatment of 10 mg/kg rivaroxaban.

Conclusions

Rivaroxaban attenuates the leukocyte-platelet-endothelial interaction, which leads to the attenuation of microthrombus formation in a mouse model of diabetes mellitus.     

Association of blood transfusion and venous thromboembolism after colorectal cancer resection

Introduction

Red blood cell (RBC) transfusion is a common event in the perioperative course of patients undergoing surgery. Transfused blood can disrupt the balance of coagulation factors and modulates the inflammatory cascade. Since inflammation and coagulation are tightly coupled, we postulated that RBC transfusion may be associated with the development of venous thromboembolic phenomena. We queried the American College of Surgeons’ National Surgical Quality Improvement Program (ACS NSQIP) database to examine the relationship between intraoperative blood transfusion and development of venous thromboembolism (VTE) in patients undergoing colorectal resection for cancer.

Materials and Methods

We analyzed the data from 2005 to 2009 for patients undergoing colorectal resections for cancer based on the primary procedure CPT-4 code and operative ICD-9 diagnosis code. The primary outcome was 30-day deep vein thrombosis (DVT) and/or pulmonary embolism (PE). Intraoperative transfusion of RBC's was categorized as: none, 1-2 units, 3-5 units and 6 units or more. DVT/PE occurrences were analyzed by multivariable forward stepwise regression (p for entry < .05, for exit > .10) to identify independent predictors of DVT.

Results

The database contained 21943 colorectal cancer resections. The DVT rate was 1.4% (306/21943) and the PE rate was 0.8% (180/21943). Patients were diagnosed with both only 40 times and the combined DVT or PE rate (VTE) was 2.0% (446/21943). After adjusting for age, gender, race, ASA (American Society of Anesthesiologists) class, emergency procedure, operative duration and complexity of the procedure (based on Relative Value Units, RVU's), along with six clinical risk factors, intraoperative blood transfusion was a significant risk factor for the development of VTE and the risk increased with increasing number of units transfused. Preoperative hematocrit did not enter the multivariable model as an independent predictor of VTE, nor did open versus laparoscopic resection or wound class.

Conclusion

In this study of 21943 patients undergoing colorectal resection for cancer, blood transfusion is associated with increased risk of VTE. Malignancy and surgery are known prothrombotic stimuli, the subset of patients receiving intraoperative RBC transfusion are even more at risk for VTE, emphasizing the need for sensible use of transfusions and rigorous thromboprophylaxis regimens.     

Caprini风险评估模型对住院脑卒中患者静脉血栓栓塞症的预测价值

目的 探讨Caprini风险评估模型对住院脑卒中患者静脉血栓栓塞症(VTE)的预测价值。方法 采用回顾性病例对照研究设计,选取2018年1月1日至2020年6月30日在该院神经内科住院的脑卒中患者中确诊为VTE的患者（75例）为VTE组;依据患者的ID号,采用机械抽样法随机抽取同期在该院神经内科住院的非VTE脑卒中患者（75例）为对照组。采用Caprini风险评估模型对两组患者进行风险评分,比较两组患者Caprini风险评分及危险度分级的差异;分析脑卒中患者并发VTE的危险因素;评价 Caprini评估模型对脑卒中并发VTE的预测价值。结果 VTE组与对照组患者风险评分及危险度分级构成无差异(P>0.05)。Caprini风险评估模型中危险因素的多因素前进法Logistic回归分析显示,年龄、肺炎、有无瘫痪是脑卒中并发VTE的危险因素。Caprini风险评估模型的曲线下面积为(0.768±0.039),灵敏度为81.3%、特异度为61.3%。以9分为极高危危险度分级界值对住院脑卒中患者并发VTE风险的预测价值最优。结论 Caprini风险评估模型对住院脑卒中患者VTE风险评估特异度低,临床使用建议以9分作为脑卒中极高危患者风险分级界值。     

颅内静脉窦血栓不同时期血栓性质动态变化

目的研究上矢状窦血栓形成后不同时期血栓的病理性质。方法用改良法建立SD大鼠上矢状窦血栓模型,将大鼠随机分为4组,每组20只。模型成功后于1、2、3、4周行核磁共振扫描观察上矢状窦闭塞和血流再通情况,并处死大鼠取上矢状窦和血栓标本,进行光镜病理学研究和透射电镜观察各组内皮细胞超微结构改变。结果核磁共振检查自发再通率8.75%。随着血栓形成时间延长,血栓逐渐出现机化和钙化,2周和1周组的血栓机化率无统计学意义(X2=0.1441,P=0.230),2周和3周组机化率有统计学差异(X2=16.942,P0.01),3周和4周组机化率无统计学差异(X2=0.784,P=0.376);2周和3周组钙化率没有统计学差异(X2=2.053,P=0.487),3周和4周组比较差异有统计学意义(X2=6.144,P=0.013)。透射电镜观察3周、4周组可见血栓机化和内皮细胞损伤。结论大鼠上矢状窦血栓形成后血栓可发生机化和钙化,机化和钙化率随时间延长而增高。     

Incidental venous thromboembolism detected by PET-CT in patients with cancer: Prevalence and impact on survival rate

Introduction

People with cancer are at increased risk of incidental venous thromboembolism (VTE) and PET-CT imaging is commonly used in this population. However, the prevalence of incidental VTE detected by PET-CT in patients with cancer and its impact on survival are unknown.

Materials and Methods

This retrospective study was approved by the local Institutional Review Board. 1331 consecutive adult patients with cancer who underwent PET-CT examination between 2009 and 2012 were included in the study (mean age: 57 ± 15 years). PET-CT reports were reviewed to identify patients with incidental VTE at the time of examination. Survival rates were assessed with Kaplan-Meier curves. The Cox proportional hazards model was used to determine the association between incidental VTE and overall survival, after controlling for clinical variables.

Results

Incidental VTE was detected in 19 patients (1.4%). Patients with genitourinary malignancies, colorectal cancer and lung cancer had the highest rates of incidental VTE at PET-CT. At multivariate analysis, incidental VTE detected by PET-CT was associated with worse overall survival independently of patient age, hospitalization status at time of PET-CT examination, and the presence of metastatic disease (Hazard ratio = 2.03; 95% confidence interval = 1.08-3.81, p = 0.028).

Conclusion

Incidental VTE was detected in 1.4% of adult patients with cancer undergoing PET-CT imaging. Diagnosis of incidental VTE at PET-CT imaging was associated with worse overall survival in this population.     

The metabolic syndrome and the risk of arterial and venous thrombosis

The metabolic syndrome is a cluster of cardiometabolic risk abnormalities related to atherosclerosis. It represents a public health problem as it affects nearly 20–30% of the general population in various countries. While the metabolic syndrome is a well recognized risk factor for cardiovascular diseases, there is little evidence about its association with venous thromboembolism. In this review, we will summarize the current knowledge on the relationship between the metabolic syndrome and arterial and venous thrombosis from a pathogenic and clinical point of view.     

Incidence, risk factors and clinical features of venous thromboembolism in newly diagnosed lymphoma patients: Results from a prospective cohort study with Asian population

Introduction

Venous thromboembolism (VTE) may be associated with treatment failure rate and quality of life deterioration in lymphoma patients. However, the majority of data regarding VTE has come from retrospective studies done in Western countries.

Materials and methods

We analyzed VTE, including pulmonary embolism and deep vein thrombosis, from Asian patients enrolled a prospective cohort study. All patients were newly diagnosed Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL).

Results

A total of 686 patients were analyzed, and the median follow-up duration was 21.8 months. There were 54 cases of VTE including deep vein thrombosis alone (33/54, 61.1%) and pulmonary embolism (21/54, 38.9%). The median time to VTE was 1.97 months, and the one-year actuarial incidence was 7.9%. The global incidence of VTE was higher in patients with NHL (51/641, 8.0%) than HL (3/45, 6.7%). All cases of VTE occurred in patients receiving chemotherapy whereas no VTE in patients without chemotherapy. VTE was also independently associated with age older than 60 years and primary central nervous system (CNS) lymphoma. No VTE-related deaths were reported among all cases of VTE. Thus, overall survival was not different between patients with and without VTE. The subgroup analysis of patients with diffuse large B-cell lymphoma showed 8.9% of one-year actuarial incidence, but the occurrence of VTE did not influence its overall survival, either.

Conclusions

The incidence of VTE in our study population was comparable to that of Western countries, and VTE was associated with chemotherapy, brain involvement and old age.