Venous thromboembolism and atherosclerosis: common denominators or different diseases?

The Caprini Risk Score for Early Prediction of Mortality in Patients With Acute Coronary Syndrome

BACKGROUND

The Caprini Risk Score (CRS) is a validated predictive instrument for venous thrombosis. Previous investigators have shown that a high CRS is associated with a higher risk of mortality from thrombotic diseases.

OBJECTIVE

The aim of this study was to assess the association between the CRS and prognosis of patients with acute coronary syndrome (ACS).

METHODS

Secondary analysis of data from a retrospective cohort study was conducted. Patients were classified into 3 CRS-based categories (CRS ≤ 2, CRS = 3-4, and CRS ≥ 5, indicating low, medium, and high, respectively). Kaplan-Meier curves and Cox regression models were used to assess the prognosis of patients with ACS. All-cause mortality and cardiac mortality were the end points.

RESULTS

Two hundred fifty-four patients (12.8%) died during follow-up. Multivariate Cox regression models identified CRS as an independent risk factor for all-cause mortality among patients with ACS (CRS = 3-4 vs CRS ≤ 2, hazard ratio: 3.268, 95% confidence interval: 1.396-7.647, P = .006; CRS ≥ 5 vs CRS ≤ 2, hazard ratio: 4.099, 95% confidence interval: 1.708-9.841, P = .002). Pearson correlation analysis showed a positive correlation between CRS and fibrinogen level ( r = 0.486, R2 = 0.765, P < .001) as well as D-dimer level ( r = 0.480, R2 = 0.465, P < .001).

CONCLUSION

The CRS is a useful prognostic assessment instrument for patients with ACS, and the risk stratification of patients with ACS can be achieved based on their CRS at admission.

Impact of venous thromboembolism on incidence of arterial thromboembolism - An analysis of German outpatient claims data

BACKGROUND

Venous thromboembolism (VTE) and arterial thromboembolism (ATE) are considered as two separate disease-entities. In recent years, studies have reported clear associations between VTE and atherosclerosis. We aimed to evaluate the long-term risk of ATE in VTE patients in comparison to controls without VTE.

METHODS

Nationwide outpatient claims data of all inhabitants with statutory health insurance in Germany were used for secondary data analysis between the years 2011 and 2020. Patients treated in 2013 were stratified by VTE event, and groups were 1:2-matched by age and sex. The hazard for an ATE event in a 5-year follow-up period between patients with and without VTE was calculated with multivariable Cox regression adjusted for age, sex, cardiovascular risk factors, and comorbidities.

RESULTS

Of 69,699,277 individuals treated in the year 2013 by German physicians in outpatient care, in total 686,382 individuals (age 59.8 ± 17.5 years, 65.4 % females) were included comprising 228,794 patients with VTE and 457,588 controls without VTE. VTE patients more often had cardiovascular risk factors (81.6 % vs. 62.2 %) and traditional VTE risk factors. The occurrence of ATE events during follow-up was 1.8 %-points higher in VTE patients in comparison to the controls (9.7 % vs. 7.9 %). VTE events were independently associated with increased occurrence of ATE events within follow-up (HR_adjusted 1.19 [99%CI 1.16-1.23], p < 0.0001).

CONCLUSIONS

Patients with a VTE event have an increased long-term risk for subsequent arterial cardiovascular events. Large prospective cohorts are needed to identify patient subgroups with a very high ATE risk after VTE.

Exploring the Causal Relationship Between Arterial and Venous Thromboembolism: A Case Series With Review of Literature

Venous thromboembolism (VTE) occurs due to venous stasis or low flow state within the blood vessels, resulting in subsequent fibrin and platelet aggregation leading to thrombosis. Arterial thrombosis affects various arteries including coronaries and is primarily due to platelet aggregation with little fibrin deposition leading to thrombosis. Although both arterial and venous thrombosis are considered as separate entities, some studies have suggested an association between them despite having distinctive causative factors. We retrospectively reviewed patients at our institution who were admitted with acute coronary syndrome (ACS) and underwent cardiac catheterization over a decade between 2009 and 2020 to look for patients who had both venous thromboembolic events and ACS. Here, we report a case series of three such patients who were found to have both VTE and coronary arterial thrombosis. However, it is unclear if having one of venous vs arterial clot increases the risk of having other vascular conditions, and further studies are needed to evaluate this hypothesis in the near future.

Clinical features and metabolic reprogramming of atherosclerotic lesions in patients with chronic thromboembolic pulmonary hypertension

Background

Chronic thromboembolic pulmonary hypertension (CTEPH) patients may present with atherosclerotic lesions in their pulmonary arteries, but their clinical characteristics remain unclear. The metabolic pathways associated with the atherosclerotic lesions may explain their occurrence and have implications for interventions, but they have not been investigated.

Methods

We collected pulmonary endarterectomy (PEA) samples of CTEPH patients from December 2016 to August 2021. Following a detailed pathological examination of the PEA specimen, the patients were divided into those with and without lesions, and age- and sex matching were performed subsequently using propensity score matching (n = 25 each). Metabolomic profiling was used to investigate the metabolites of the proximal lesions in the PEA specimens.

Results

In our study population, 27.2% of all PEA specimens were found to contain atherosclerotic lesions. CTEPH patients with atherosclerotic lesions were more likely to have a history of symptomatic embolism and had a longer timespan between embolism and surgery, whereas the classic risk factors of systemic and coronary circulation could not distinguish CTEPH patients with or without atherosclerotic lesions. Metabolomic profiling revealed that the formation of atherosclerotic lesions in CTEPH was closely related to altered glycine, serine, and threonine metabolic axes, possibly involved in cellular senescence, energy metabolism, and a proinflammatory microenvironment.

Conclusion

The occurrence of atherosclerotic lesions in the pulmonary arteries of CTEPH was associated with symptomatic thromboembolic history and prolonged disease duration. The results revealed a new link between atherosclerotic lesions and aberrant amino acid metabolism in the context of CTEPH for the first time. This study has characterized the clinical and metabolic profiles of this distinct group of CTEPH patients, providing new insights into disease pathogenesis and potential interventions.

Incidence and impact of venous thromboembolism in hospitalized patients with Crohn's disease

BACKGROUND

Crohn's disease (CD) is associated with an increased risk for venous thromboembolism (VTE). Beside higher VTE risk, data on impact of VTE on survival and risk factors for the occurrence of VTE in CD are sparse.

METHODS

The German nationwide inpatient sample was screened for patients admitted due to CD (ICD-code K50). CD hospitalizations were stratified for VTE and risk-factors for VTE and impact of VTE on in-hospital case-fatality rate were investigated.

RESULTS

Overall, 333,975 hospitalizations of patients due to CD were counted in Germany (median age 38.0 [IQR 24.0-52.0] years, 56.0 % females) during the observational period 2005-2018. VTE rate increased slightly from 0.6 % (2005) to 0.7 % (2018) (β 0.000097 [95%CI 0.000027 to 0.000167], P = 0.007) 2005-2018 and with age-decade (β 0.0017 [95%CI 0.0016 to 0.0019], P < 0.001). In total, 0.7 % (2295) of the CD inpatients had a VTE event. Patients with VTE were in median 12 years older (49.0 [34.0-62.0] vs. 37.0 [24.0-52.0] years, P < 0.001) and colon-involvement was in those patients more prevalent (32.0 % vs.27.7 %, P < 0.001). Age ≥ 70 years, obesity, colon-involvement, cancer, surgery, thrombophilia, and heart failure were strongly associated with higher risk of VTE in CD patients. In-hospital death occurred 15-times more often in CD with VTE than without (4.5 % vs. 0.3 %, P < 0.001). VTE was independently associated with increased in-hospital case-fatality rate (OR 9.31 [95%CI 7.54-11.50], P < 0.001).

CONCLUSIONS

VTE is a life-threatening event in hospitalized CD patients associated with 9.3-fold increased case-fatality rate. Older age, obesity, colon involvement, cancer, surgery, thrombophilia and heart failure were strong risk factors for VTE in CD.

Venous Thromboembolism and Risk of Cancer in Users of Low-Dose Aspirin: A Danish Population-Based Cohort Study

Background  Aspirin may reduce the risk of cancer, particularly gastrointestinal cancer, and venous thromboembolism (VTE). VTE can be the first symptom of occult cancer, but whether it is also a marker of occult cancer in aspirin users remains unknown. Therefore, we investigated the risk of cancer subsequent to VTE among users of low-dose aspirin.

Methods  We conducted a population-based cohort study using data from Danish health registries for the years 2001 to 2018. We identified all patients with a first-time diagnosis of VTE who also redeemed a prescription for low-dose aspirin (75–150mg) within 90 days prior to the first-time VTE. We categorized aspirin users by the number of prescriptions filled as new users (<5 prescriptions), short-term users (5–19 prescriptions), and long-term users (>19 prescriptions). We computed the absolute cancer risks and standardized incidence ratios (SIRs) for cancer using national cancer incidence rates.

Results  We followed-up 11,759 users of low-dose aspirin with VTE. Long-term users comprised 50% of aspirin users. The 1-year absolute risk of cancer was 6.0% for new users and 6.7% for short-term and long-term users, with corresponding SIRs of 3.3 (95% confidence interval [CI]: 2.8–4.0), 3.2 (95% CI: 2.9–3.7), and 2.8 (95% CI: 2.6–3.2), respectively. After the first year of follow-up, the SIR decreased to 1.2 (95% CI: 1.1–1.4) for new users, 1.1 (95% CI: 1.1–1.3) for short-term users, and 1.1 (95% CI: 1.0–1.2) for long-term users.

Conclusion  VTE may be a harbinger of cancer, even in users of low-dose aspirin, regardless of duration of use.

Impact of Systemic Atherosclerosis on Clinical Characteristics and Short-term Outcomes in Patients with Deep Venous Thrombosis or Thrombophlebitis

BACKGROUND

Venous thromboembolism (VTE) and atherosclerosis are accompanied by substantial cardiovascular mortality; links between both disease entities were reported. We aimed to investigate the impact of systemic atherosclerosis on adverse outcomes in patients with deep venous thrombosis or thrombophlebitis (DVT) and to identify differences in DVT patients with and without systemic atherosclerosis.

METHODS

The German nationwide inpatient sample was used for this analysis. Patients admitted for DVT were included in this study and stratified by systemic atherosclerosis (composite of coronary artery disease, myocardial infarction, ischemic stroke, and/or atherosclerotic arterial diseases). We compared DVT patients with (DVT+Athero) and without (DVT-Athero) systemic atherosclerosis and analysed the impact of systemic atherosclerosis on adverse outcomes.

RESULTS

Overall, 489,679 patients with DVT (55.7% females) were included in this analysis. Among these, 53,309 (10.9%) were coded with concomitant systemic atherosclerosis with age-dependent incline. Concomitant PE (4.1% vs.3.8%, P=0.001) was more frequently in DVT-Athero and risk for PE in DVT patients was independently associated with absence of systemic atherosclerosis (OR 0.87 [95%CI 0.83-0.91], P<0.001). In-hospital mortality (3.4% vs.1.4%, P<0.001) and adverse in-hospital events (2.2% vs.0.8%,P<0.001) were more prevalent in DVT+Athero compared to DVT-Athero; both, in-hospital mortality (OR 1.52 [95%CI 1.41-1.63], P<0.001) and adverse in-hospital events (OR 1.49 [95%CI 1.40-1.58], P<0.001) were affected independently of sex, age and comorbidities by systemic atherosclerosis.

CONCLUSIONS

Systemic atherosclerosis in DVT patients was accompanied by poorer outcomes. Systemic atherosclerosis was associated with higher bleeding rate and with isolated DVT (without concomitant PE).

Venous thromboembolism in patients hospitalized for knee joint replacement surgery

Patients undergoing knee joint replacement (KJR) are at high risk of postoperative venous thromboembolism (VTE), but data on the time trends of VTE rate in this population are sparse. In this analysis of the German nationwide inpatient sample, we included all hospitalizations for elective primary KJR in Germany 2005-2016. Overall, 1,804,496 hospitalized patients with elective primary KJR (65.1% women, 70.0 years [IQR 63.0-76.0]) were included in the analysis. During hospitalization, VTE was documented in 23,297 (1.3%) patients. Total numbers of primary KJR increased from 129,832 in 2005 to 167,881 in 2016 (β-(slope)-estimate 1,978 [95% CI 1,951 to 2,004], P < 0.001). In-hospital VTE decreased from 2,429 (1.9% of all hospitalizations for KJR) to 1,548 (0.9%) cases (β-estimate - 0.77 [95% CI - 0.81 to - 0.72], P < 0.001), and in-hospital death rate from 0.14% (184 deaths) to 0.09% (146 deaths) (β-estimate - 0.44 deaths per year [95% CI - 0.59 to - 0.30], P < 0.001). Infections during hospitalization were associated with a higher VTE risk. VTE events were independently associated with in-hospital death (OR 20.86 [95% CI 18.78-23.15], P < 0.001). Annual number of KJR performed in Germany increased by almost 30% between 2005 and 2016. In parallel, in-hospital VTE rates decreased from 1.9 to 0.9%. Perioperative infections were associated with higher risk for VTE. Patients who developed VTE had a 21-fold increased risk of in-hospital death.

Venous thromboembolism in patients hospitalized for hip joint replacement surgery

BACKGROUND

Venous thromboembolism (VTE) is a potentially life-threatening disease. Major transient risk factors include trauma, surgery, and immobilization. Patients undergoing hip joint replacement (HJR) are characterized by a high risk of postoperative VTE, but data on the time trends of VTE rates in this population are sparse.

METHODS

In an analysis of the German nationwide inpatient sample, we included all hospitalizations for elective primary HJR in Germany from 2005 to 2016. Time trends of the surgical procedure, overall death rates, and VTE rates were analysed, and predictors of VTE identified.

RESULTS

Overall, 1,885,839 inpatients with elective primary HJR (59.1% women, 51.4% ≥70 years) were included in the analysis. During hospitalization, VTE was documented in 11,554 (0.6%) patients. While total numbers of primary HJR increased from 145,223 in 2005 to 171,421 in 2016 (β-(slope)-estimate 1818 [95%CI 1083 to 2553], P < 0.001), in-hospital VTE decreased from 1288 (0.9%) to 843 (0.5%) cases (β-estimate -0.71 [95%CI -0.77 to -0.65], P < 0.001), and in-hospital death rate from 0.33% (476 deaths) to 0.29% (498 deaths) (β-estimate -0.11 [95%CI -0.20 to -0.02], P = 0.018). Infections during hospitalization were associated with higher VTE risk than cancer and cardiovascular events. VTE events were independently associated with an increased death risk (OR 15.19 [95%CI 14.19-16.86], P < 0.001).

CONCLUSIONS

While total numbers of HJR increased significantly in Germany between 2005 and 2016, in-hospital rates of VTE decreased from 0.9% to 0.5%. Patients with perioperative VTE had a 15-fold increase of in-hospital death. Cancer, cardiovascular disease and perioperative infections were associated with higher risk for VTE.

Ginkgo biloba Induces Thrombomodulin Expression and Tissue-Type Plasminogen Activator Secretion via the Activation of Krüppel-Like Factor 2 within Endothelial Cells

The effects of thrombo-prevention, such as antiplatelet and anticoagulant activity, have been reported with the usage of Ginkgo biloba extract (GbE); however, the detailed mechanism has not yet been fully investigated, especially the role of Krüppel-like factor 2 (KLF2). This study aimed to investigate whether GbE can activate KLF2 and then induce thrombomodulin (TM) and tissue-type plasminogen activator (t-PA) secretion to enhance the effects of thrombo-prevention. Different concentrations of GbE were incubated with human umbilical vein endothelial cells (HUVECs) to evaluate its effect on endothelial cells. We found that KLF2 expression is correlated to the risk of atherosclerosis and venous thromboembolism in clinical practice. In the HUVEC cell model, GbE stimulated the expression of KLF2 in a dose-dependent manner. Moreover, TM and t-PA secretion increased when the cells were cultured with GbE. Both the expressions and activities of TM and t-PA in the GbE-treated cells declined after KLF2 was blocked by shKLF2. In sum, with GbE treatment, KLF2 expression in human endothelial cells was significantly activated, which in turn induced an increase in the protein expression and activity of TM and t-PA. After shRNA inhibited the KLF2 expression, GbE stopped inducing the expression and activity of TM and t-PA. These findings suggest that GbE exerts an antithrombotic effect on endothelial cells by increasing the TM expression and t-PA secretion; further, KLF2 is a key factor in this mechanism.

Statins and risk of thromboembolism: A meta-regression to disentangle the efficacy-to-effectiveness gap using observational and trial evidence

BACKGROUND AND AIMS

Meta-analyses of randomised controlled trials (RCTs) and observational studies indicate a lower risk of venous thromboembolism (VTE) associated with statin treatment. We aimed to compare the effect of statin therapy in these two settings and to identify and quantify potential factors to explain statin efficacy and effectiveness.

METHODS AND RESULTS

We electronically searched on December 11th, 2018, articles reporting on first VTE events in RCTs (statin vs placebo) and in observational studies (participants exposed vs non-exposed to statin). We performed Knapp-Hartung random-effect meta-analyses to calculate pooled relative risks (RRs) of VTE events associated with statin treatment, separately for RCTs and observational studies; and estimated the ratio of the relative risk (RRR) comparing RCTs and observational studies using meta-regressions, progressively adjusted for study-level characteristics. Twenty-one RCTs (115,107 participants; 959 events) and 8 observational studies (2,898,096 participants; 19,671 events) were included. Pooled RRs for RCTs and observational studies were 0.82 (95% confidence interval (CI): 0.67-1.00; I² 19.2%) and 0.60 (95% CI: 0.42-0.86; I² 86.3%), respectively. In meta-regressions, the unadjusted RRR indicated a nonsignificant 23% smaller benefit in RCTs (RRR 0.77; 95% CI: 0.52-1.13); accounting for age, sex, geographical region, and duration of follow-up, there was a sensible change of the RRR which resulted 0.30 (95% CI: 0.13-0.68).

CONCLUSION

Differences in the characteristics between patients included in RCTs and those in observational studies may account for the differential effect of statins in preventing VTE in the two settings.

Rate and impact of venous thromboembolism in patients with ST-segment elevation myocardial infarction: Analysis of the Nationwide Inpatient Sample database 2003–2013

Venous thromboembolism (VTE) and coronary artery disease are major health issues that cause substantial morbidity and mortality. New data have emerged suggesting that these two conditions could have a close relationship. Thus, we sought to determine the trends in annual rate of VTE occurrence in patients with ST-segment elevation myocardial infarction (STEMI) and measure its impact on in-hospital mortality, bleeding complications, and cost and length of hospitalization. We queried the 2003–2013 Nationwide Inpatient Sample databases to identify adults with primary diagnosis of STEMI. VTE events were then allocated. Inpatient outcomes of patients with VTE were compared to those without VTE. Out of 2,495,757 hospitalizations for STEMI, VTE was diagnosed in 25,149 (1%) hospitalizations. Patients who experienced VTE were older (mean age: 67.5 vs 64.8, p < 0.01) and had a higher proportion of black patients (10.1% vs 7.7%, p < 0.001) and females (40.1% vs 35%, p < 0.001) compared to patients without VTE. There was an increasing trend in the rate of VTE during the study period (2003: 0.8% vs 2013: 1.0%, p < 0.001). Patients with VTE had a prolonged hospitalization (median: 9 vs 3 days, p < 0.001), increased cost, higher risk of gastrointestinal bleeding (OR: 2.13, p < 0.001), intracranial hemorrhage (OR: 2.14, p < 0.001), blood transfusions (OR: 1.94, p < 0.001), and mortality (OR: 1.39, p < 0.001). The rate of VTE occurrence in patients with STEMI in our study was 10 per 1000 admissions. VTE was associated with more bleeding complications, longer hospital stays, higher costs, and mortality. These findings suggest that a more aggressive approach for VTE prophylaxis may be warranted in this population.

ACVIM consensus statement on the treatment of immune-mediated hemolytic anemia in dogs

Immune‐mediated hemolytic anemia (IMHA) causes severe anemia in dogs and is associated with considerable morbidity and mortality. Treatment with various immunosuppressive and antithrombotic drugs has been described anecdotally and in previous studies, but little consensus exists among veterinarians as to the optimal regimen to employ and maintain after diagnosis of the disease. To address this inconsistency and provide evidence‐based guidelines for treatment of IMHA in dogs, we identified and extracted data from studies published in the veterinary literature. We developed a novel tool for evaluation of evidence quality, using it to assess study design, diagnostic criteria, explanation of treatment regimens, and validity of statistical methods. In combination with our clinical experience and comparable guidelines for humans afflicted with autoimmune hemolytic anemia, we used the conclusions of this process to make a set of clinical recommendations regarding treatment of IMHA in dogs, which we refined subsequently by conducting several iterations of Delphi review. Additionally, we considered emerging treatments for IMHA in dogs and highlighted areas deserving of future research. Comments were solicited from several professional bodies to maximize clinical applicability before the recommendations were submitted for publication. The resulting document is intended to provide clinical guidelines for management of IMHA in dogs. These guidelines should be implemented pragmatically, with consideration of animal, owner, and veterinary factors that may vary among cases.

Consensus on the Rational Use of Antithrombotics in Veterinary Critical Care (CURATIVE): Domain 2-Defining rational therapeutic usage

OBJECTIVES

To systematically review available evidence to determine when small animals at risk of thrombosis should be treated with antiplatelet agents and anticoagulants, which antiplatelet and anticoagulant agents are most effective, and when multimodal therapy is indicated.

DESIGN

Standardized, systematic evaluation of the literature, categorization of relevant articles according to level of evidence (LOE) and quality (Good, Fair, or Poor), and development of consensus on conclusions via a Delphi-style survey for application of the concepts to clinical practice. Draft recommendations were presented at 2 international veterinary conferences and made available for community assessment, review, and comment prior to final revisions and publication.

SETTINGS

Academic and referral veterinary medical centers.

RESULTS

Databases searched included Medline via PubMed and CAB abstracts. Twelve Population Intervention Comparison Outcome questions were devised and generated corresponding worksheets investigating indications for use of antithrombotic drugs in small animals. Seventy-eight studies were reviewed in detail. Most studies assessed were experimentally controlled laboratory studies in companion animals (56 LOE 3) with smaller numbers of LOE 2 (1), LOE 4 (5), LOE 5 (6), and LOE 6 (4) studies assessed. Only 5 randomized controlled clinical trials were identified (LOE 1, Good-Fair). The 12 worksheets generated 21 guidelines with 17 guideline statements that were refined during 3 rounds of Delphi surveys. A high degree of consensus was reached across all guideline recommendations during the Delphi process.

CONCLUSIONS

Overall, systematic evidence evaluations generated 2 strong recommendations, 19 weak recommendations (formulated as suggestions), 9 situations where the evidence was insufficient to make strong recommendations, and 8 situations where no relevant evidence was retrieved to aid guideline generation. Numerous significant knowledge gaps were highlighted by the evidence reviews undertaken, indicating the need for substantial additional research in this field.

Impact of symptomatic atherosclerosis in patients with pulmonary embolism

BACKGROUND

Atherosclerosis is associated with increased cardiovascular mortality. Associations between venous thromboembolism and atherosclerosis were recently reported. We aimed to investigate the impact of symptomatic atherosclerosis on adverse outcomes in patients with pulmonary embolism (PE) and to identify significant differences among patients with PE stratified by symptomatic atherosclerosis.

METHODS

Patients were selected by screening the nationwide inpatients sample for PE (ICD-code I26) stratified by symptomatic atherosclerosis (composite of coronary artery disease [ICD-code I25], myocardial infarction [ICD-code I21], ischemic stroke [ICD-code I63], and/or atherosclerotic arterial diseases [ICD-code I70]). We compared PE patients with (PE + Athero) and without (PE - Athero) symptomatic atherosclerosis and analysed the impact of symptomatic atherosclerosis on adverse outcomes.

RESULTS

Overall, 213,995 patients with PE (54.2% females) were included in this analysis. Of these, 30,157 (14.1%) had symptomatic atherosclerosis with age-dependent incline. Deep vein thrombosis or thrombophlebitis (45.1% vs. 36.9%, P < 0.001) was more commonly observed in the PE - Athero group (Odds Ratio (OR) 0.713 [95% CI 0.695-0.731], P < 0.001). In-hospital mortality (12.1% vs. 9.6%, P < 0.001) and adverse in-hospital events (16.8% vs. 12.6%, P < 0.001) were affected by symptomatic atherosclerosis; both in-hospital mortality (OR 1.107 [95% CI 1.061-1.155], P < 0.001) and adverse in-hospital outcomes (OR 1.143 [95%CI 1.102-1.186], P < 0.001) were affected independently of age, gender, comorbidities, and reperfusion treatments.

CONCLUSIONS

Symptomatic atherosclerosis in patients with PE increased with age and was associated with a poorer outcome. Cardiovascular-atherosclerotic diseases might play a major role in thrombus formation in isolated PE.

Genome-Wide Association and Functional Studies Identify SCML4 and THSD7A as Novel Susceptibility Genes for Coronary Artery Disease

OBJECTIVE

The genetic contribution to coronary artery disease (CAD) remains largely unclear. We combined genetic screening with functional characterizations to identify novel loci and candidate genes for CAD.

APPROACH AND RESULTS

We performed genome-wide screening followed by multicenter validation in 8 cohorts consisting of 21 828 participants of Han ethnicity and identified 3 novel intragenic SNPs (single nucleotide polymorphisms), rs9486729 (SCML4 [Scm polycomb group protein-like 4]; odds ratio, 1.25; 95% CI, 1.17-1.34; P=3.51×10^-11), rs17165136 (THSD7A [thrombospondin type 1 domain-containing 7A]; odds ratio 1.28; 95% CI, 1.21-1.35; P<1.00×10^-25), and rs852787 (DAB1 [disabled-1]; odds ratio, 1.29; 95% CI, 1.21-1.38; P=2.02×10^-14), associated with CAD with genome-wide significance. The risk allele of rs9486729 and protective allele of rs17165136 were associated with the decreased expression of their host genes, SCML4 and THSD7A, respectively, whereas rs852787 did not have transcriptional effects on any gene. Knockdown of SCML4 activated endothelial cells by increasing the expression of IL-6, E-selectin, and ICAM and weakened their antiapoptotic activity, whereas the knockdown of THSD7A had little effect on these endothelial cell functions but attenuated monocyte adhesion via decreasing the expression of ICAM, L-selectin, and ITGB2. We further showed that inhibiting the expression of SCML4 exacerbated endothelial dysfunction and vascular remodeling in a rat model with partial carotid ligation.

CONCLUSIONS

We identify 3 novel loci associated with CAD and show that 2 genes, SCML4 and THSD7A, make functional contributions to atherosclerosis. How rs852787 and its host gene DAB1 are linked to CAD needs further studies.

Epidemiology and pathophysiology of venous thromboembolism: similarities with atherothrombosis and the role of inflammation

Venous thromboembolism (VTE) is a multifactorial disease. Major provoking factors (e. g. surgery, cancer, major trauma, and immobilisation) are identified in 50–60 % of patients, while the remaining cases are classified as unprovoked. However, minor predisposing conditions may be detectable in these patients, possibly concurring to the pathophysiology of the disease, especially when co-existing. In recent years, the role of chronic inflammatory disorders, infectious diseases and traditional cardiovascular risk factors has been extensively investigated. Inflammation, with its underlying prothrombotic state, could be the potential link between these risk factors, as well as the explanation for the reported association between arterial and venous thromboembolic events.

Hemostasis in Hypothyroidism and Autoimmune Thyroid Disorders

CONTEXT

There are contradictory results on the effect of hypothyroidism on the changes in hemostasis. Inadequate population-based studies limited their clinical implications, mainly on the risk of venous thromboembolism (VTE). This paper reviews the studies on laboratory and population-based findings regarding hemostatic changes and risk of VTE in hypothyroidism and autoimmune thyroid disorders.

EVIDENCE ACQUISITION

A comprehensive literature search was conducted employing MEDLINE database. The following words were used for the search: Hypothyroidism; thyroiditis, autoimmune; blood coagulation factors; blood coagulation tests; hemostasis, blood coagulation disorders; thyroid hormones; myxedema; venous thromboembolism; fibrinolysis, receptors thyroid hormone. The papers that were related to hypothyroidism and autoimmune thyroid disorder and hemostasis are used in this review.

RESULTS

Overt hypothyroidism is more associated with a hypocoagulable state. Decreased platelet count, aggregation and agglutination, von Willebrand factor antigen and activity, several coagulation factors such as factor VIII, IX, XI, VII, and plasminogen activator-1 are detected in overt hypothyrodism. Increased fibrinogen has been detected in subclinical hypothyroidism and autoimmune thyroid disease rendering a tendency towards a hypercoagulability state. Increased factor VII and its activity, and plasminogen activator inhibitor-1 are among several findings contributing to a prothrombotic state in subclinical hypothyroidism.

CONCLUSIONS

Overt hypothyroidism is associated with a hypocoagulable state and subclinical hypothyroidism and autoimmune thyroid disorders may induce a prothrombotic state. However, there are contradictory findings for the abovementioned thyroid disorders. Prospective studies on the risk of VTE in various levels of hypofunctioning of the thyroid and autoimmune thyroid disorders are warranted.

High prevalence of severe coronary artery disease in elderly patients with non-operable chronic thromboembolic pulmonary hypertension referred for balloon pulmonary angioplasty

INTRODUCTION

Balloon pulmonary angioplasty (BPA) is a new emerging catheter-based alternative treatment option for patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH).

AIM

To show that all elderly CTEPH patients referred for BPA are at higher risk of obstructive coronary artery disease and that, in daily practice, they should undergo invasive coronary angiography.

MATERIAL AND METHODS

Eleven patients at the age of at least 65 years (6 males, 5 females, 77.2 ±5.9 years) with confirmed non-operable type II or type III CTEPH, considered for BPA, underwent elective coronary angiography. Severe obstructive coronary artery disease (CAD) was diagnosed when stenosis of left main coronary artery ≥ 50% or stenosis of ≥ 70% of epicardial arteries was angiographically confirmed. We also screened for CAD consecutive age- and sex-matched 114 PE survivors (52 males, 62 females, 74.8 ±7.2 years) with excluded CTEPH.

RESULTS

Severe CAD was more frequent in elderly patients with non-operable type II or type III CTEPH candidates for BPA than in elderly acute PE survivors with excluded CTEPH (54.5% vs. 16.7%, p < 0.01), and therefore elderly CTEPH patients referred for BPA were at higher risk of CAD (OR = 5.9, 95% CI: 1.64-21.46, p = 0.007) when compared to elderly survivors after acute PE with excluded CTEPH.

CONCLUSIONS

All elderly CTEPH patients referred for BPA are at higher risk of severe CAD and should routinely undergo invasive coronary angiography before BPA.

Emerging anticoagulant strategies

Despite the introduction of direct oral anticoagulants (DOACs), the search for more effective and safer antithrombotic strategies continues. Better understanding of the pathogenesis of thrombosis has fostered 2 new approaches to achieving this goal. First, evidence that thrombin may be as important as platelets to thrombosis at sites of arterial injury and that platelets contribute to venous thrombosis has prompted trials comparing anticoagulants with aspirin for secondary prevention in arterial thrombosis and aspirin with anticoagulants for primary and secondary prevention of venous thrombosis. These studies will help identify novel treatment strategies. Second, emerging data that naturally occurring polyphosphates activate the contact system and that this system is critical for thrombus stabilization and growth have identified factor XII (FXII) and FXI as targets for new anticoagulants that may be even safer than the DOACs. Studies are needed to determine whether FXI or FXII is the better target and to compare the efficacy and safety of these new strategies with current standards of care for the prevention or treatment of thrombosis. Focusing on these advances, this article outlines how treatment strategies for thrombosis are evolving and describes the rationale and approaches to targeting FXII and FXI. These emerging anticoagulant strategies should address unmet needs and reduce the systemic underuse of anticoagulation because of the fear of bleeding.

Antithrombotic therapy in peripheral artery disease

Antiplatelet agents are recommended for the reduction of major adverse cardiovascular events among all patients with symptomatic peripheral artery disease. However, the optimal antiplatelet regimen and duration of therapy in peripheral artery disease (PAD) remains unclear, largely due to limited and conflicting data in this patient population. This article reviews current data on antithrombotic therapy in PAD and discusses the implications of this data for current practice and future research.

Older soft tissue sarcoma patients experience increased rates of venous thromboembolic events: a retrospective cohort study of SEER-Medicare data

BACKGROUND

Venous thromboembolic co-morbidities can have a significant impact on treatment response, treatment options, quality of life, and ultimately, survival from cancer. There is a dearth of published information on venous thromboembolic co-morbidity among older soft tissue sarcoma patients.

METHODS

SEER-Medicare linked data (1993-2005) was utilized for this retrospective cohort analysis (n = 3,480 soft tissue sarcoma patients). Non-cancer patients were frequency-matched by age to cancer patients at a ratio of 1:1; coverage and follow-up requirements were the same as for soft tissue sarcoma cases. Venous thromboembolic events were divided into three groups of interest: deep vein thrombosis, pulmonary embolism, and other thromboembolic events. Relative incidence rates of venous thromboembolic events in soft tissue sarcoma patients with a recent history of cardiovascular event or venous thromboembolic event (12 months before diagnosis) versus soft tissue sarcoma patients without such a recent history were calculated using the Cox proportional hazard models. The Cox proportional hazard model was used to build predictive models to identify important risk factors for each venous thromboembolic event of interest among soft tissue sarcoma patients. Relative incidence rate of VTEs in cancer patients (12 months after diagnosis) versus non-cancer cases (12 months after index date) was calculated using multivariable Cox proportional hazard models.

RESULTS

We observed that among older soft tissue sarcoma patients, 10.6% experienced a deep vein thrombosis, 3.0% experienced a pulmonary embolism, and 3.1% experienced other thromboembolic events in the 12 months after sarcoma diagnosis. On average, 60% of venous thromboembolic events occurred in the first 90 days after sarcoma diagnosis. The highest rates of deep vein thrombosis and pulmonary embolism after sarcoma diagnosis were seen in patients with sarcoma not otherwise specified (deep vein thrombosis: 204/1,000 p-y and pulmonary embolism: 50/1,000 p-y). Recent history of a venous thromboembolic event was the strongest predictor of a subsequent venous thromboembolic event after soft tissue sarcoma diagnosis.

CONCLUSION

Venous thromboembolic events are common and serious co-morbidities that should be closely monitored in older soft tissue sarcoma patients.

Are myocardial infarction and venous thromboembolism associated? Population-based case-control and cohort studies

INTRODUCTION

Because the association of myocardial infarction (MI) and venous thromboembolism (VTE) is uncertain, we tested MI as a VTE risk factor and VTE as a predictor of MI.

MATERIALS AND METHODS

Using Rochester Epidemiology Project resources, we identified all Olmsted County, MN residents with objectively-diagnosed incident VTE over the 13-year period, 1988-2000 (n=1311), one to two resident controls per VTE case (n=1511), and all residents with incident MI over the 31-year period, 1979-2010. For VTE cases and controls, we reviewed their complete medical records in the community for VTE and MI risk factors. Using conditional logistic regression we tested MI as a potential VTE risk factor, both unadjusted and after adjusting for VTE risk factors. We also followed VTE cases and controls without prior MI forward in time for incident MI through 12/31/2010, and using Cox proportional hazards modeling, tested VTE as a predictor of MI, both unadjusted and after adjusting for MI risk factors.

RESULTS

The number (%) of MI prior to VTE among cases and controls were 75 (5.7) and 51 (3.4), respectively, and the number (%) of MI after VTE among cases and controls were 58 (4.4) and 77 (5.1), respectively. In univariate analyses, MI was significantly associated with VTE but not after adjusting for VTE risk factors. In both univariate and multivariate analyses, VTE (overall or idiopathic) was not a predictor of MI.

CONCLUSIONS

MI is not an independent risk factor for VTE, and VTE is not a predictor of MI.

Older renal cell cancer patients experience increased rates of venous thromboembolic events: a retrospective cohort study of SEER-Medicare data

Background

Venous thromboembolic co-morbidities can have a significant impact on treatment response, treatment options, quality of life, and ultimately, survival from cancer. The extent of venous thromboembolic co-morbidity among older renal cell cancer patients is poorly described in the literature. It is important to understand the scope of venous thromboembolic events, before and after diagnosis, in order to offer renal cell cancer patients optimal care and improved quality of life.

Methods

The main goal of this study was to estimate and describe the incidence of venous thromboembolic events before and after renal cell cancer diagnosis. SEER-Medicare linked data (1991–2003) was utilized for this retrospective cohort analysis (n = 11,950) of older renal cell cancer patients (≥ 65 years). Incidence rates and proportions in addition to multivariable Cox proportional hazard and logistic regression models were utilized to describe the incidence and relative risk of venous thromboembolic events.

Results

We observed that in the 12 months after diagnosis, 8.3% of renal cell cancer patients experienced a deep venous thrombosis, 2.4% experienced a pulmonary embolism, and 3.9% experienced other thromboembolic events. Nearly 70% of venous thromboembolic events occurred in the first 90 days after renal cell cancer diagnosis. Renal cell cancer patients were 2–4 times more likely to have a venous thromboembolic event in the 12 months after cancer diagnosis than non-cancer patients followed during the same time frame. Recent history of a venous event substantially increased the risk of that same event in the 12 months after diagnosis (HR = 5.2-18.8).

Conclusion

Venous thromboembolic events are common and serious co-morbidities that should be closely monitored in older renal cell cancer patients, particularly during the first 3 months following diagnosis and among those with a recent history of a venous thromboembolic event.

Genetic determinants of 5-lipoxygenase pathway in a Spanish population and their relationship with cardiovascular risk

OBJECTIVE

Leukotrienes (LT) play a role in inflammation, cardiovascular diseases, and cancer. Although some studies suggest that there are genes that determine variability of some LT-related phenotypes, the genetic influence on these phenotypes has not been evaluated.

METHODS

The relative contributions of genetic and environmental influences to the 5-lipoxygenase pathway-related phenotypes (5-Lipoxygenase, five lipoxygenase activating protein (FLAP), LTA(4)-hydrolase and LTC(4)-synthase expression, and LTB(4)-plasma concentration and LTB(4) production by stimulated whole blood) were assessed in a sample of 934 individuals in 35 extended families. Our design is based on extended families recruited through a probands with idiopathic thrombophilia. This strategy allows us the analysis of the effects of measured covariates (such as sex, age and smoking), genes, and environmental variables shared by members of a household.

RESULTS

All of these phenotypes showed significant genetic contributions, with heritabilities ranging from 0.33 to 0.51 for enzyme expression and from 0.25 to 0.50 for LTB(4) production of the residual phenotypic variance. Significant phenotypic and genetic correlation among the LT-related traits was found. More importantly, FLAP and LTA(4)-hydrolase expression exhibit significant genetic correlations with arterial thrombosis, indicating that some of the genes that influence quantitative variation in these phenotypes also influence the risk of thrombosis.

CONCLUSION

This is the first study that quantifies the genetic component of 5-Lipoxygenase pathway phenotypes. The high heritability of these traits and the significant genetic correlations between arterial thrombosis and some of these phenotypes suggest that the exploitation of correlated quantitative phenotypes will aid the search for susceptibility genes.

Association between venous and arterial thrombosis: clinical implications

Venous and arterial thromboses have traditionally been regarded as separate diseases with different causes. However, recent epidemiological studies have documented an association between these vascular complications, probably due to the presence of more overlapping risk factors than previously recognized. This narrative review first focuses on the risk factors associated with both arterial and venous thrombotic events. In addition, it summarizes the more recent data on the risk of incident venous thromboembolism in patients with asymptomatic atherosclerosis or clinical manifestations of atherothrombosis, as well as on the risk of incident atherothrombotic events in patients with previous manifestation of venous thromboembolism. The potential clinical implications are also discussed.

Idiopathic deep venous thrombosis and arterial endothelial dysfunction in the elderly

Arterial and venous thrombosis have always been regarded as different pathologies and epidemiological studies have examined the association between venous thrombosis and indicators of atherosclerosis and/or arterial thromboembolic events. We measured the flow-mediated dilation (FMD), a well-known marker of arterial endothelial dysfunction, in young-middle-aged and old-aged patients with and without unprovoked deep venous thrombosis (DVT). The aim of this study was to investigate whether DVT was a significant predictor for impaired FMD, considering all the patients and young-middle-aged (age < 65 years) and old-aged (age ≥ 65 years) patients separately. FMD was measured in the brachial artery on a population of 120 subjects with the same atherosclerosis risk factors, 68 male and 52 female, 70 young-middle-aged subjects (mean age ± SD 49.5 ± 10.5 years) and 50 old-aged subjects (76.2 ± 7.7 years). Patients with DVT showed a significant decrease of FMD compared to patients without DVT (6.8 ± 5.5% vs. 10.9 ± 3.5%, p < 0.001). Moreover, old-aged patients showed a significant decrease of FMD compared to the young-middle-aged subjects (7.4 ± 4.1% vs. 9.8 ± 5.3%, p = 0.005). In the whole study population, DVT was strongly associated with FMD (risk factors adjusted β = -4.14, p < 0.001). A significant interaction between age and the presence of DVT on predicting FMD was found (p = 0.003) suggesting a differential behavior of DVT as predictor of FMD. In young-middle-aged group, multivariate model confirmed that DVT was the most significant predictor of continuous FMD (β = -6.06, p < 0.001). On the contrary, DVT was no more a predictor of FMD in the old age group (β = -0.73, p = 0.556). Furthermore, old-aged patients without DVT showed a statistically significant decrease of FMD compared to the young-middle-aged subjects without DVT (8.2 ± 2.1% vs. 12.6 ± 2.7%, p<0.001) and old-aged patients with DVT showed a not statistically significant decrease of the FMD compared to the young-middle-aged patients with DVT (6.7 ± 5.3% vs. 6.8 ± 5.7%, p = 0.932). In conclusion, young-middle-aged patients with spontaneous DVT show an impaired FMD, whereas this impairment in old-aged subjects is evident independently from the presence or absence of DVT. Aging per se may be associated with physiologic abnormalities in the systemic arteries and with endothelial dysfunction.

Venous thromboembolism does not share strong familial susceptibility with ischemic stroke: a nationwide family study in Sweden

BACKGROUND

Coagulation allelic variants associated with venous thromboembolism (VTE) have been suggested to be involved in the pathogenesis of ischemic stroke. This nationwide study aimed at determining whether VTE shares familial susceptibility with ischemic stroke.

METHOD AND RESULTS

The Swedish Multigeneration Register of 0- to 75-year-old subjects was linked to the Swedish Hospital Discharge Register and the Cause of Death Register for the period 1987 to 2007. Odds ratios (ORs) for VTE and ischemic stroke were determined in 2 ways: odds of ischemic stroke in offspring whose parents had been diagnosed with VTE, and odds of VTE in offspring whose parents had been diagnosed with ischemic stroke. The analyses were repeated for siblings and spouses. Offspring of parents with VTE (n=25,929) were at increased risk for ischemic stroke (n=5595): OR, 1.10 (95% confidence interval [CI], 1.06-1.14). Siblings of probands with VTE (n=45,132) had no increased risk of ischemic stroke (n=1716): OR, 1.05 (95% CI, 1.00-1.11). Spouses of probands with VTE (n=24,106) were at increased risk for ischemic stroke (n=940): OR, 1.18 (95% CI, 1.10-1.27). The risks for VTE in relatives of probands with ischemic stroke were OR, 1.15; 95% CI, 1.10-1.21 (offspring); OR, 1.07; 95% CI, 1.02-1.12 (siblings); and OR, 1.21; 95% CI, 1.11-1.32 (spouses).

CONCLUSIONS

VTE does not share strong familial susceptibility with ischemic stroke in the Swedish population. Moreover, familial nongenetic factors contribute to the observed weak familial associations. The present study suggests that it is unlikely that strong shared disease-causing mutations exist to a large extent in the Swedish population.

JUPITER and satellites: Clinical implications of the JUPITER study and its secondary analyses

THE JUSTIFICATION FOR THE USE OF STATINS IN PREVENTION: an intervention trial evaluating rosuvastatin (JUPITER) study was a real breakthrough in primary cardiovascular disease prevention with statins, since it was conducted in apparently healthy individuals with normal levels of low-density lipoprotein cholesterol (LDL-C < 130 mg/dL) and increased inflammatory state, reflected by a high concentration of high-sensitivity C-reactive protein (hs-CRP ≥ 2 mg/L). These individuals would not have qualified for statin treatment according to current treatment guidelines. In JUPITER, rosuvastatin was associated with significant reductions in cardiovascular outcomes as well as in overall mortality compared with placebo. In this paper the most important secondary analyses of the JUPITER trial are discussed, by focusing on their novel findings regarding the role of statins in primary prevention. Also, the characteristics of otherwise healthy normocholesterolemic subjects who are anticipated to benefit more from statin treatment in the clinical setting are discussed. Subjects at "intermediate" or "high" 10-year risk according to the Framingham score, those who exhibit low post-treatment levels of both LDL-C (< 70 mg/dL) and hs-CRP (< 1 mg/L), who are 70 years of age or older, as well as those with moderate chronic kidney disease (estimated glomerular filtration rate < 60 mL/min every 1.73 m(2)) are anticipated to benefit more from statin treatment. Unlikely other statin primary prevention trials, JUPITER added to our knowledge that statins may be effective drugs in the primary prevention of cardiovascular disease in normocholesterolemic individuals at moderate-to-high risk. Also, statin treatment may reduce the risk of venous thromboembolism and preserve renal function. An increase in physician-reported diabetes represents a major safety concern associated with the use of the most potent statins.

Venous thromboembolism does not share strong familial susceptibility with coronary heart disease: a nationwide family study in Sweden

AIMS

This nationwide study aimed to determine whether venous thromboembolism (VTE) shares familial susceptibility with coronary heart disease (CHD).

METHODS AND RESULTS

Data from the Swedish Multigeneration Register for subjects aged 0-76 years old for the period 1964-2008 were linked to the Hospital Discharge Register and Cause of Death Register. Familial risks of VTE and CHD were examined in two ways: risk of CHD in offspring whose parents had been diagnosed with VTE, and risk of VTE in offspring whose parents had been diagnosed with CHD. The analyses were repeated separately for siblings and spouses. In total, 174 768 offspring had CHD and 56 302 VTE. No association between VTE and CHD was observed among siblings. Among offspring, a lower risk of CHD was observed in subjects whose parents had suffered from VTE [standardized incidence ratio (SIR) 0.94 (95% confidence interval (CI) 0.92-0.95)], while offspring of parents with CHD had an increased risk of VTE [SIR 1.03 (95% CI 1.01-1.04)]. In spouses of VTE patients, an increased risk of CHD was observed [SIR 1.02 (95% CI 1.01-1.03)]. Conversely, risk of VTE was increased among spouses of CHD patients [SIR 1.03 (95% CI 1.02-1.03)]. Subanalyses of cases of myocardial infarction and pulmonary embolism/deep venous thrombosis showed similar results.

CONCLUSION

The familial background of CHD is different from that of VTE. The present study suggests that it is unlikely that shared disease-causing mutations exist to a large extent in the population.

Vitamin B12 deficiency, hyperhomocysteinemia and thrombosis: a case and control study

This study aimed at assessing the relationship between thrombosis, hyperhomocysteinemia and vitamin B12 deficiency using a case-control study carried out in 326 patients with thrombosis (case group) and 351 patients from the same hospital (control group). Apart from the classic risk factors, a number of hematological variables were evaluated, including serum vitamin B12 (B12), red cell folate (RCF), and serum homocysteine (Hcy). An evaluation of serum methylmalonic acid (MMA) and a clinical study were carried out to investigate B12 pathology. Results of univariate analysis demonstrated decreased B12 levels in thrombosis (Student's t test, p < 0.0001). Vitamin B12 below 200 pmol/l (LB200) or below 150 pmol/l (LB150), and red cell folate below 600 nmol/l were found in 17.2, 8.6, and 2.2% of cases with thromboembolism, respectively. An increase in Hcy was detected in 86 cases with thrombosis (26.3%). An abnormality in vitamin B12 and/or renal function was found in 80% of cases with hyperHcy and thrombosis. The MMA increase demonstrated that vitamin B12 deficiency was present in these patients with low levels of vitamin B12 in serum, and the MMA levels were in concordance with Hcy levels. The clinical study revealed B12 malabsorption in most cases with LB200. Multivariate analysis showed that serum vitamin B12 (RR 0.998, CI 0.997-0.999) was moderately related to thromboembolism. The results indicated that vitamin B12 deficiency was common among patients with hyperhomocysteinemia and thrombosis. Moreover, HyperHcy was caused by vitamin B12 deficiency and/or chronic renal failure in most patients with thrombosis. As the main cause of vitamin B12 deficiency was vitamin malabsorption, parenteral vitamin B12 with or without folic acid should be administered for the treatment of this condition. However, it remains to be demonstrated whether this treatment approach prevents recurrent thromboses in patients with vitamin B12 deficiency and thrombosis, as suggested by some case reports.

Statin use and the prevention of venous thromboembolism: a meta-analysis

AIMS

Statins are thought to have antithrombotic properties and may attenuate patients' odds of developing venous thromboembolism (VTE), but clinical studies have yielded variable estimates of this effect. The aim was to conduct a meta-analysis to evaluate the effect of statin use on development of VTE.

METHODS

Randomised controlled trials (RCTs) and observational studies evaluating the effects of statins on the incidence of VTE were selected from MEDLINE (1996 to August 2009), Cochrane CENTRAL (second quarter, 2009), Cochrane Database of Systematic Reviews (second quarter, 2009) and a manual review of references. While no further restrictions were placed on RCTs, observational studies were only included if they reported adjusted effect sizes using appropriate methods. Development of deep vein thrombosis (DVT), pulmonary embolism (PE) and any VTE from RCTs and observational studies were pooled using traditional meta analytic techniques with a random-effects model.

RESULTS

Ten studies were identified and eligible for meta-analysis. Upon meta-analysis, statin use was associated with a statistically significant reduction in the odds of developing VTE (AOR 0.68, 95% CI 0.54-0.86), DVT (AOR 0.59, 95% CI 0.43-0.82) and PE (AOR 0.70, 95% CI 0.53-0.94).

DISCUSSION

Statin use is associated with significantly reduced odds of developing VTE, DVT or PE by 32%, 41% and 30% respectively. Our meta-analysis included one RCT, JUPITER, which alone provided statistically significant reduction in the odds of developing VTE and DVT (43% and 55% respectively), and a nonsignificant reduction on PE.

CONCLUSION

Currently available evidence suggests that statins can reduce patients' odds of developing VTE.

Polymeric Microspheres for Medical Applications

Synthetic polymeric microspheres find application in a wide range of medical applications. Among other applications, microspheres are being used as bulking agents, embolic- or drug-delivery particles. The exact composition of the spheres varies with the application and therefore a large array of materials has been used to produce microspheres. In this review, the relation between microsphere synthesis and application is discussed for a number of microspheres that are used for different treatment strategies.

Venous and arterial thrombosis: Two aspects of the same disease?

An increasing body of evidence suggests the likelihood of a link between venous and arterial thrombosis. The two vascular complications share several risk factors, such as age, obesity, diabetes mellitus, blood hypertension, hypertriglyceridemia, and metabolic syndrome. Moreover, there are many examples of conditions accounting for both venous and arterial thrombosis, such as the antiphospholipid antibody syndrome, hyperhomocysteinemia, malignancies, infections, and the use of hormonal treatment. Finally, several recent studies have consistently shown that patients with venous thromboembolism are at a higher risk of arterial thrombotic complications than matched control individuals. We, therefore, speculate the two vascular complications are simultaneously triggered by biological stimuli responsible for activating coagulation and inflammatory pathways in both the arterial and the venous system. Future studies are needed to clarify the nature of this association, to assess its extent, and to evaluate its implications for clinical practice.

A randomized trial of rosuvastatin in the prevention of venous thromboembolism

BACKGROUND

Controversy persists regarding the extent of shared pathways between arterial and venous thrombosis and whether treatments of known efficacy for one disease process have consistent benefits for the other. Observational studies have yielded variable estimates of the effect of statin therapy on the risk of venous thromboembolism, and evidence from randomized trials is lacking.

METHODS

We randomly assigned 17,802 apparently healthy men and women with both low-density lipoprotein (LDL) cholesterol levels of less than 130 mg per deciliter (3.4 mmol per liter) and high-sensitivity C-reactive protein levels of 2.0 mg per liter or higher to receive rosuvastatin, 20 mg per day, or placebo. We followed participants for the first occurrence of pulmonary embolism or deep-vein thrombosis and performed analyses of the data on an intention-to-treat basis.

RESULTS

During a median follow-up period of 1.9 years (maximum, 5.0), symptomatic venous thromboembolism occurred in 94 participants: 34 in the rosuvastatin group and 60 in the placebo group. The rates of venous thromboembolism were 0.18 and 0.32 event per 100 person-years of follow-up in the rosuvastatin and placebo groups, respectively (hazard ratio with rosuvastatin, 0.57; 95% confidence interval [CI], 0.37 to 0.86; P=0.007); the corresponding rates for unprovoked venous thromboembolism (i.e., occurring in the absence of a known malignant condition, trauma, hospitalization, or surgery) were 0.10 and 0.17 (hazard ratio, 0.61; 95% CI, 0.35 to 1.09; P=0.09) and for provoked venous thromboembolism (i.e., occurring in patients with cancer or during or shortly after trauma, hospitalization, or surgery), 0.08 and 0.16 (hazard ratio, 0.52; 95% CI, 0.28 to 0.96; P=0.03). The rates of pulmonary embolism were 0.09 in the rosuvastatin group and 0.12 in the placebo group (hazard ratio, 0.77; 95% CI, 0.41 to 1.45; P=0.42), whereas the rates of deep-vein thrombosis only were 0.09 and 0.20, respectively (hazard ratio, 0.45; 95% CI, 0.25 to 0.79; P=0.004). Consistent effects were observed in all the subgroups examined. No significant differences were seen between treatment groups in the rates of bleeding episodes.

CONCLUSIONS

In this trial of apparently healthy persons, rosuvastatin significantly reduced the occurrence of symptomatic venous thromboembolism. (ClinicalTrials.gov number, NCT00239681.)

Arterial cardiovascular events, statins, low-dose aspirin and subsequent risk of venous thromboembolism: a population-based case-control study

BACKGROUND

Atherosclerotic disease has been associated with the risk of venous thromboembolism, but the available data are conflicting. There are similar confusions regarding the association of the use of aspirin and statins with venous thromboembolism.

OBJECTIVES

To determine whether arterial cardiovascular events, use of statins and low-dose aspirin were associated with the risk of venous thromboembolism.

PATIENTS AND METHODS

In this population-based case-control study, we identified 5824 patients with venous thromboembolism and 58 240 population controls with a complete hospital and prescription history. We used logistic regression to estimate the relative risk of venous thromboembolism, adjusted for potentially confounding factors.

RESULTS

Patients with a history of arterial cardiovascular events had a clearly increased relative risk. An event within 3 months before the index date conferred large increases in risk [relative risk 4.22 (95% confidence interval (CI), 2.33-7.64) after myocardial infarction, 4.41 (95% CI, 2.92-6.65) after stroke]. Myocardial infarction more than 3 months before the index date was not significantly associated with risk, although there was a relative risk of 1.29 (95% CI, 1.05-1.57) for myocardial infarction more than 60 months previously. A history of stroke was associated with small increases in risk after 3 months. Current use of statins was associated with a reduced risk of venous thromboembolism [relative risk=0.74 (95% CI, 0.63-0.85)]. Aspirin use was not associated with risk.

CONCLUSIONS

Patients with cardiovascular events are at a short-term increased risk of venous thromboembolism. Statins might prevent venous thromboembolism but aspirin does not. However, as the study is non-randomized residual confounding cannot be excluded.

Venous and arterial thrombosis: different sides of the same coin?

Until recently venous and arterial thrombosis were considered mechanistically distinct entities. However, their separate nature has been challenged by several studies showing that these conditions share a number of risk factors such as age, obesity, infections and the metabolic syndrome. The existence of an association is further supported by the finding that patients with venous thromboembolism are at higher risk of arterial events and vice versa. This review article addresses the association between venous and arterial thrombosis and its clinical and therapeutic implications. We conclude that arterial and venous thrombosis are mechanistically different, but that common risk factors are more relevant and frequent than previously thought.

Deep vein thrombosis resolution is impaired in diet-induced type 2 diabetic mice

OBJECTIVE

Type 2 diabetes mellitus results in a procoagulant and thrombogenic state that could predispose diabetic individuals to develop venous thrombosis. We sought to determine whether diet-induced type 2 diabetes mellitus affects deep venous thrombosis (DVT) resolution in a murine model.

METHODS

C57Bl/6 mice were fed a low-fat or a high-fat diet (n = 10) for 10 weeks, after which DVT was created in the inferior vena cava (IVC) by a combination of low flow and endothelial damage. The IVC and thrombus were harvested at 1 and 2 weeks. Thrombus resolution and neovascularization were investigated through transfemoral angiography (n = 10), thrombus size (n = 4) and weight (n = 10), and nitric oxide synthase 3 immunoquantification (n = 4). Macrophage content was assessed by CD68 immunoreactivity (n = 4). The fibrinolytic system (urokinase plasminogen activator [uPA] and plasminogen activator inhibitor-1 [PAI-1]) was analyzed by Western immunoblotting (n = 6) and immunohistochemistry (n = 4). Total collagen was stained by Sirius red. Matrix metalloproteinases (MMP)-2 and MMP-9 activities were evaluated by zymography and their expressions by Western immunoblotting (n = 6) and immunohistochemistry (n = 4).

RESULTS

Diabetic mice had significantly larger and heavier thrombi at 1 and 2 weeks (P < .05), threefold less neovascularization (P < .05), and 35-fold increase in macrophage content (P < .01), than control mice 2 weeks after surgery. IVC recanalization was documented in 90% of 2-week control mice and in 10% of 2-week diabetic mice (P < .01). Increased vein wall collagen and less uPA and more PAI-1 expressions with a decreased uPA/PAI-1 ratio (31%, P < .01) were documented at 2 weeks in diabetic mice. MMP-2 and MMP-9 activities and expressions were significantly increased in diabetic mice at 1 and 2 weeks (P < .05) compared with control mice.

CONCLUSION

Diet-induced type 2 diabetes may impair DVT resolution through altered inflammatory, fibrinolytic, and MMP responses.