Dose-related effect of statins in venous thrombosis risk reduction

A two-sample Mendelian randomization study of circulating lipids and deep venous thrombosis

In view of the current debate about the relationship between lipids and deep venous thrombosis (DVT) in clinical studies, a two-sample Mendelian randomization (MR) study was conducted to clarify the effects of five circulating lipids (apolipoprotein A1, apolipoprotein B, low-density lipoprotein, high-density lipoprotein and triglycerides) on DVT from the perspective of genetic inheritance. Five lipids (exposure) were analysed by MR with DVT (outcome) from two different data sources. For the analysis, we used inverse variance weighting and a weighted mode, weighted median, simple mode and MR-Egger regression to analyse the effect of circulating lipids on DVT. In addition, we used the MR-Egger intercept test, Cochran's Q test and "leave-one-out" sensitivity analysis to evaluate horizontal multiplicity, heterogeneity and stability, respectively, in the analysis. In the analysis, the two-sample Mendelian randomization analysis of five common circulating lipids and DVT showed that common circulating lipids had no causal effect on DVT, which is somewhat inconsistent with the findings of many published observational studies. Based on our results, our two-sample MR analysis failed to detect a statistically significant causal relationship between five common circulating lipids and DVT.

Lipophilic vs. hydrophilic statins and psychiatric hospitalizations and emergency room visits in US Veterans with schizophrenia and bipolar disorder

Objective –

Psychiatric hospitalizations and emergency department (ED) visits are costly, stigmatizing, and often ineffective. Given the immune and kynurenine activation in bipolar disorder (BD) and schizophrenia, as well as the immune-modulatory effects of statins, we aimed to compare the relative risk (RRs) of psychiatric hospitalizations and ED visits between individuals prescribed lipophilic vs. hydrophilic statins vs. no statins. We hypothesized (a) reduced rates of hospitalization and ER utilization with statins versus no statins and (b) differences in outcomes between statins, as lipophilia increases the capability to penetrate the blood–brain barrier with potentially beneficial neuroimmune, antioxidant, neuroprotective, neurotrophic, and endothelial stabilizing effects, and, in contrast, potentially detrimental decreases in brain cholesterol concentrations leading to serotoninergic dysfunction, changes in membrane lipid composition, thus affecting ion channels and receptors.

Methods –

We used VA service utilization data from October 1, 2010 to September 30, 2015. The RRs for psychiatric hospitalization and ED visits, were estimated using robust Poisson regression analyses. The number of individuals analyzed was 683,129.

Results –

Individuals with schizophrenia and BD who received prescriptions for either lipophilic or hydrophilic statins had a lower RR of psychiatric hospitalization or ED visits relative to nonstatin controls. Hydrophilic statins were significantly associated with lower RRs of psychiatric hospitalization but not of ED visits, compared to lipophilic statins.

Conclusion –

The reduction in psychiatric hospitalizations in statin users (vs. nonusers) should be interpreted cautiously, as it carries a high risk of confounding by indication. While the lower RR of psychiatric hospitalizations in hydrophilic statins relative to the lipophilic statins is relatively bias free, the finding bears replication in a specifically designed study. If replicated, important clinical implications for personalizing statin treatment in patients with mental illness, investigating add-on statins for improved therapeutic control, and mechanistic exploration for identifying new treatment targets are natural next steps.

Statins can benefit patients with primary membranous nephropathy on venous thromboembolism

Objective

The aim of this study was to investigate the role of prophylactic use of statin in venous thromboembolism (VTE) in patients with primary membranous nephropathy (PMN).

Methods

A total of 734 patients with PMN were consecutively enrolled in this retrospective study. 564 patients had received statins prescription, while 170 patients did not. Kaplan–Meier methods were used for cumulative incidence plots of thromboembolic events and Cox proportional hazards regression models were used to assess risk factors. Finally, the effects of different potency of statins were evaluated.

Results

In the cohort, 37 patients (5.0%) experienced VTE. In a univariate Cox proportional hazard model, the hazard ratio (HR) for VTE in statin users versus statin non-users was 0.5 (95% CI 0.3–0.8, p = .03). Multivariable model proportional-hazards analysis corrected for co-medications and risk factors revealed that adjusted HR was 0.4 (95% CI 0.1–0.7, p = .03). According to the type and dose, statin users were assigned into 3 groups: high-intensity group (n = 278), moderate-intensity group (n = 186), and low-intensity group (n = 49). In comparison, incidences of VTEs in the three groups were similar (2.9% vs 4.8% vs 2.0%, p = .45).

Conclusions

The prophylactic use of statins could effectively decrease the occurrence of VTE in patients with PMN, and the benefits have no difference in different potency of statins.

Not Just Arterial Damage: Increased Incidence of Venous Thromboembolic Events in Cardiovascular Patients With Elevated Plasma Levels of Apolipoprotein CIII

Background

Apolipoprotein CIII (apo CIII) is a crucial player in triglyceride‐rich lipoprotein metabolism, but may also act pleiotropically, provoking inflammatory responses and stimulating coagulation. Elevated apoCIII plasma levels have been associated with increased activity of coagulation factors. Since these features of prothrombotic diathesis are linked with venous thromboembolism (VTE), we hypothesized that apo CIII plays a role in VTE.

Methods and Results

We recorded nonfatal VTE events in 1020 patients (age 63.3±11.4 years; 29.1% women) with or without coronary artery disease (79.1% with coronary artery disease and 20.9% without coronary artery disease) during a long follow‐up. Complete plasma lipid and apolipoproteins were available for all patients. Forty‐five patients (4.4%) experienced nonfatal VTE events during a median follow‐up period of 144 months. Apo CIII plasma concentration at enrollment was higher in patients with VTE compared with patients without VTE (12.2 [95% CI, 11.10–13.5] mg/dL vs 10.6 [95% CI, 10.4–10.9] mg/dL, respectively; P=0.011). Patients with apo CIII levels above the median value (10.6 mg/dL) exhibited an increased risk of VTE (incidence rate, 6.0 [95% CI, 4.0–8.0] vs 1.8 [95% CI, 0.7–2.9] VTE events/1000 person‐years; unadjusted hazard ratio [HR], 3.42 [95% CI, 1.73–6.75]; P<0.001). This association was confirmed after adjustment for sex, age, coronary artery disease diagnosis, body mass index, hypertension, and anticoagulant treatment at enrollment (HR, 2.66; 95% CI, 1.31–5.37 [P=0.007]), with inclusion of lipid parameters in the Cox model (HR, 3.74; 95% CI, 1.24–11.33 [P=0.019]), and even with exclusion of patients who died at follow‐up (HR, 3.92; 95% CI, 1.68–9.14 [P=0.002]) or patients taking anticoagulants (HR, 3.39; 95% CI, 1.72–6.69 [P<0.001]).

Conclusions

Our results suggest that high plasma apo CIII concentrations may predict an increased risk of VTE in patients with cardiovascular disease.

Statins and Inflammation: New Therapeutic Opportunities in Psychiatry

Statins, which are widely used to treat hypercholesterolemia, have anti-inflammatory and anti-oxidant effects. These are thought to be responsible for the potential effects of statins on various psychiatric disorders. In this study, we comprehensively review the literature to investigate the effects of statins on various psychiatric disorders including depression, schizophrenia, and dementia. In addition, we review adverse effects and drug interactions of statins to give clinically useful information guiding statin use in the psychiatric field. Statins seem useful in reducing depression, particularly in patients with physical disorders such as cardiovascular disease. In patients with schizophrenia, negative symptoms may be reduced by adjuvant statin therapy. Studies on cohorts at risk for dementia have generally shown protective effects of statins, while those on treatment for dementia show inconsistent results. In conclusion, statins used in combination with conventional psychotropic medications may be effective for various psychiatric disorders including depression, schizophrenia, and dementia. Further study is required to determine optimal doses and duration of statin use for the treatment of psychiatric disorders.

Urokinase Attenuates Pulmonary Thromboembolism in an Animal Model by Inhibition of Inflammatory Response

Inflammatory response is an important determining factor for the mortality of patients with pulmonary thromboembolism. Inflammatory mediators can promote thrombus formation and increase hemodynamic instability. Urokinase is a commonly used drug for the treatment of PTE. The effect of urokinase on inflammatory reaction in PTE is still unclear. Our study was aimed at evaluating the effects of the intervention of urokinase and urokinase combined with aspirin in PTE rats. Results revealed that a large amount of infiltrated inflammatory cells surrounding the bronchus, vessels, and pulmonary mesenchyme, and even pulmonary abscess were observed in the PTE rats. CX3CL1/CX3CR1 coexpression, CX3CL1/NF-κB coexpression, and TXA2 were significantly higher. After treatment with urokinase, pulmonary embolism was partially dissolved and inflammatory cell infiltration was significantly reduced. The expression of TNNI3, BNP, D2D, PASP, PADP, PAMP, and TXA2, as well as CX3CL1/CX3CR1 coexpression and CX3CL1/NF-κB coexpression were significantly lowered. Aspirin showed no synergistic action. Therefore, these findings suggested the occurrence of inflammation during the process of PTE in rats. Urokinase treatment reduced the inflammatory response.

Statins, haemostatic factors and thrombotic risk

PURPOSE OF REVIEW

Statins reduce cholesterol synthesis and promote low-density lipoprotein clearance from circulation. Beyond their cholesterol-lowering action, statins may interfere with haemostasis. This review aims to provide an update on the impact of statin treatment on markers of haemostasis and platelet function and on thrombosis-related outcomes.

RECENT FINDINGS

Different coagulation factors are modulated by statins, leading to inhibition of coagulation and increased fibrinolysis. Also, an impact of statins on platelet function has been documented. From a clinical perspective, several observational studies have revealed a reduced incidence of venous thromboembolism in patients receiving statins, which has been argued in some available studies and meta-analyses. Furthermore, a beneficial effect of early statin initiation following acute coronary syndrome for short-term prevention of thrombosis-related events has been documented, but the available data are still not consistent.

SUMMARY

Although statins influence the levels of a multitude of haemostatic factors in an antithrombotic direction, data supporting their use for venous thromboembolism prevention are not consistent, and the impact of statins on early vascular events following acute coronary syndrome is still debated. Whether the robust long-term beneficial effects of statins in reducing cardiovascular risk may be also explained by persistent changes in haemostatic factors needs further exploration.

Statins as a preventative therapy for venous thromboembolism

The anti-inflammatory effects of statins have likely not been used to their fullest extent, particularly in reducing venous thromboembolic events. Current therapy for thrombotic events hinges on anticoagulation via heparin, warfarin or new oral anticoagulants. Interventional procedures with thrombectomy may also play a critical role. Unfortunately, thrombotic events can occur and recur despite meticulous anticoagulation therapy. Venous thromboembolism (VTE) includes both deep vein thrombosis (DVT) and pulmonary embolism (PE), two complicated and prevalent diseases that can cause chronic disease states such as post-thrombotic syndrome (PTS). In 2009 the JUPITER trial demonstrated that rosuvastatin may be effective when dealing with vascular inflammation by providing an anti-inflammatory effect. Multiple subsequent studies have looked at this association with some promising findings. The mechanism of action for statins is not entirely understood but there has been a variety of proposals and subsequent testing of inflammatory biomarkers. Additional prospective trials are needed to confirm the possible benefit of VTE reduction through an anti-inflammatory effect, but if this can be shown then statins may become a safe adjunctive therapy for VTE prevention.

Statin use and venous thromboembolism in cancer: A large, active comparator, propensity score matched cohort study

BACKGROUND

Statins have been shown to have a protective effect for venous thromboembolism (VTE) in the general population. This study sought to assess the association between statins and the risk for cancer-associated deep vein thrombosis (DVT) and pulmonary embolism (PE).

METHODS

Patients with newly diagnosed cancer were followed for up to one year in a healthcare claims database (2010-2013). Three treatment groups included statin users, non-statin cholesterol lowering medication users, and an untreated group with pre-existing indications for statin therapy (hyperlipidemia, diabetes, or heart disease). Propensity score matched groups were compared using competing risks survival models for DVT and PE outcomes reporting the hazard ratios (HR) between the treatment groups. Sensitivity analyses assessed the influence of age and individual medications.

RESULTS

The total cohort included 170,459 patients, which, after matching, were similar on baseline characteristics. The overall model showed a statistically significant protective effect for statins compared to no treatment attributed only to leukemia for DVT (HR=0.77, 95% CI 0.61-0.99) and colorectal cancers for PE (HR=0.80, 95% CI 0.64-0.99) in stratified analyses. There were generally no differences in outcomes between statins and non-statins and no individual statin use showed results different from the class effect.

CONCLUSIONS

In this propensity score matched sample of patients with cancer, statins were shown to have a small protective effect in some cancers for DVT or PE compared to no treatment and little difference compared to an active control group. The lack of effect was consistent across statins and was also not found for any of the sensitivity analyses included.

New insights into the mechanisms of action of aspirin and its use in the prevention and treatment of arterial and venous thromboembolism

The antithrombotic action of aspirin has long been recognized. Aspirin inhibits platelet function through irreversible inhibition of cyclooxygenase (COX) activity. Until recently, aspirin has been mainly used for primary and secondary prevention of arterial antithrombotic events. The aim of this study was to review the literature with regard to the various mechanisms of the newly discovered effects of aspirin in the prevention of the initiation and development of venous thrombosis. For this purpose, we used relevant data from the latest numerous scientific studies, including review articles, original research articles, double-blinded randomized controlled trials, a prospective combined analysis, a meta-analysis of randomized trials, evidence-based clinical practice guidelines, and multicenter studies. Aspirin is used in the prevention of venous thromboembolism (VTE), especially the prevention of recurrent VTE in patients with unprovoked VTE who were treated with vitamin K antagonists (VKAs) or with non-vitamin K antagonist oral anticoagulants (NOACs). Numerous studies have shown that aspirin reduces the rate of recurrent VTE in patients, following cessation of VKAs or NOACs. Furthermore, low doses of aspirin are suitable for long-term therapy in patients recovering from orthopedic or other surgeries. Aspirin is indicated for the primary and secondary prevention as well as the treatment of cardiovascular diseases, including acute coronary syndrome, myocardial infarction, peripheral artery disease, acute ischemic stroke, and transient ischemic attack (especially in atrial fibrillation or mechanical heart valves). Aspirin can prevent or treat recurrent unprovoked VTEs as well as VTEs occurring after various surgeries or in patients with malignant disease. Recent trials have suggested that the long-term use of low-dose aspirin is effective not only in the prevention and treatment of arterial thrombosis but also in the prevention and treatment of VTE. Compared with VKAs and NOACs, aspirin has a reduced risk of bleeding.

Inflammation in venous thromboembolism: Cause or consequence?

Venous thromboembolism (VTE) which includes deep vein thrombosis (DVT) and pulmonary thromboembolism (PTE) is a moderately common disease especially in elderly population with high rate of recurrence and complications. Evidence is accumulating that VTE is not restricted to coagulation system and immune system appears to be involved in formation and resolution of thrombus. The present study was aimed at reviewing current evidences on immune system abnormalities such as alterations in cytokines, chemokines and immune cells. Also, current evidences suggest that; a, inflammation in general functions as a double-edged sword, b, inflammation can be both a cause and a consequence of VTE, and c, current anti-coagulation therapies are not well-equipped with the capacity to selectively inhibit inflammatory cells and pathways. Applying such inferences for selective pharmacological targeting of immune mediators in VTE and thereby for adoption of higher effective anti-thromboinflammatory strategies, either therapeutic or prophylactic, is henceforth to be considered as the line of research for future.

Combination of factor Xa inhibition and antiplatelet therapy after stenting in patients with iliofemoral post-thrombotic venous obstruction

OBJECTIVES

Studies addressing optimal postprocedural pharmacological management after endovascular stenting of iliofemoral post-thrombotic venous obstruction are lacking. We report our early clinical experience with a combination of rivaroxaban and clopidogrel in patients after iliofemoral post-thrombotic venous obstruction stenting.

METHODS

Demographic, procedural, and follow-up data of nine patients (seven women; mean age of 32 ± 11 years) undergoing 10 procedures for iliofemoral post-thrombotic venous obstruction performed between August 2012 and January 2014 were retrospectively reviewed. After endovascular intervention, all patients were administered 20 mg rivaroxaban once daily (s.i.d.) and 75 mg clopidogrel s.i.d. or every second day depending on the individual drug responsiveness for at least six months. The adenosine diphosphate-induced platelet aggregation (platelet aggregation, in aggregation units × min) was assessed on a Multiplate analyzer. Patency was verified venographically at procedure end and was evaluated with duplex ultrasound in regular follow-ups.

RESULTS

Iliofemoral venous flow was successfully re-established by percutaneous endovascular angioplasty and stent implantation in nine left-sided and one bilateral iliofemoral post-thrombotic venous obstruction. Under dual treatment strategy of rivaroxaban and clopidogrel with platelet aggregation control (median (range): 285 aggregation units × min (192; 402)), none of the patients experienced restenosis or stent thrombosis, respectively. After a median follow-up of 14 months (range: 6-26 months), the primary patency rate was 100% and no in-stent restenosis, stent occlusion or relevant minor or major bleeding occurred.

CONCLUSION

Combined factor Xa inhibition and tailored antiplatelet therapy after stenting of iliofemoral post-thrombotic venous obstruction were safe and performed favorably in terms of vessel patency.

Concurrent use of statins and hormone therapy and risk of venous thromboembolism in postmenopausal women: a population-based case-control study

OBJECTIVE

Statins and hormone therapy (HT), often used concurrently in postmenopausal women, have antagonist effects on the risk of venous thromboembolism (VTE). This study aims to determine whether statins attenuate the increased VTE risk associated with HT.

METHODS

We conducted a nested case-control study within a population-based cohort of women aged 50 to 79 years between January 1, 1987 and March 1, 2008, who were identified from the UK General Practice Research Database. Cases of VTE occurring during follow-up were identified and each matched with up to 10 controls from the cohort. Odds ratios (ORs) for the effects of concurrent HT and statin use on the risk of VTE were estimated using conditional logistic regression with interaction terms.

RESULTS

The cohort included 955,582 postmenopausal women, with 23,505 cases of VTE matched with 231,562 controls. Regardless of any HT use, current use of statins was associated with a decreased risk of VTE (OR, 0.83; 95% CI, 0.78-0.87). The interaction between statin use and HT use was of borderline significance (P = 0.053). Consequently, among nonusers of statins, the risk of VTE was elevated with current use of oral estrogen and progestogen combinations (OR, 1.55; 95% CI, 1.45-1.66) but this risk was not elevated among users of statins (OR, 0.98; 95% CI, 0.56-1.73). There was no such modification of the OR with statins and other HT types and formulations.

CONCLUSIONS

Statins could potentially attenuate the increased risk associated with HT combinations of oral estrogens and progestogens. This observation needs further confirmation in other large cohorts.

Statins, aspirin and risk of venous thromboembolic events in breast cancer patients

Venous thromboembolic events (VTE's) are associated with decreased survival in breast cancer patients. Studies suggested that statins reduce the risk of VTE's in the general population. Low dose Aspirin reduces risk of VTE's in high risk populations. The Breast Cancer in Northern Israel Study is a case-control study of consecutive breast cancer cases diagnosed in northern Israel and matched controls. The present analysis was limited to cases with breast cancer enrolled in the study. Data was extracted from Clalit Health Services (CHS) database and from computerized pharmacy records. Out of 3,585 patients enrolled, 261 (7.3%) had a VTE during median follow up of 4.2 years. The 1 and 2 year cumulative incidence was 2.64 and 3.65%. 55.7% of patients used statins, predominantly simvastatin (75.8%). 44.5% used aspirin. In multivariate analysis neither statins nor aspirin use was associated with a reduced risk for a VTE. Unadjusted HR for statin and aspirin was 1.461 (1.018-2.096) and 1.293 (0.846-1.976), respectively, and the adjusted HR were 0.86 (0.648-1.14) and 1.013 (0.737-1.392). Results were similar when only simvastatin use was assessed. Metastatic disease, chemotherapy, age, BMI and presence of comorbidities were significantly associated with risk of VTE's. Our study is the first to look at the effect of statins and aspirin on the incidence of VTE's in patients with breast cancer. In our cohort, statin and aspirin use did not decrease the risk for a VTE. Our results might be explained by use of low potency statins (simvastatin and pravastatin) and by alternate mechanisms for VTE formation in patients with cancer.

Proatherogenic oxidized low-density lipoprotein/β2-glycoprotein I complexes in arterial and venous disease

OxLDL/β2GPI complexes have been implicated in the initiation and progression of atherosclerosis and associated with disease severity and adverse outcomes. We investigate the significance of anti-oxLDL/β2GPI antibodies and oxLDL/β2GPI complexes in patients with arterial and idiopathic venous disease. A cohort of 61 arterial disease patients, 32 idiopathic venous disease patients, and 53 healthy controls was studied. Because statins influence oxLDL/β2GPI, these complexes were analyzed on subjects not taking statins. Arterial and venous groups expressed higher levels of IgG anti-oxLDL/β2GPI antibodies than controls without any other significant clinical association. OxLDL/β2GPI complexes were significantly elevated in arterial (0.69 U/mL, P = 0.004) and venous disease (0.54 U/mL, P = 0.025) than controls (0.39 U/mL). Among arterial diseases, oxLDL/β2GPI was 0.85 U/mL for carotid artery disease, 0.72 U/mL for peripheral artery disease, and 0.52 U/mL for abdominal aortic aneurysm. There was a significant association with male gender, age, hypertension, and history of thrombosis. Subjects with oxLDL/β2GPI above the median (0.25 U/mL) were more likely to have arterial (OR 4.5, P = 0.004) or venous disease (OR 4.1, P = 0.008). Multivariate regression indicated that males (P = 0.021), high cholesterol (P = 0.011), and carotid disease (P = 0.023) were significant predictors of oxLDL/β2GPI. The coexistence of oxLDL/β2GPI in arterial and venous disease may suggest a common oxidative mechanism that independently predicts carotid artery disease.

Statins are associated with low risk of venous thromboembolism in patients with cancer: a prospective and observational cohort study

INTRODUCTION

Patients with cancer are at risk of venous thromboembolism (VTE). Statin-use has been shown to be associated with low risk of VTE in patients without cancer, but data in cancer patients is scarce. The objective of this study was to evaluate the association of statins with risk of VTE in cancer patients in a prospective observational cohort study.

MATERIALS AND METHODS

Patients with newly diagnosed cancer or progression of disease after remission were included and prospectively followed for a maximum of 2 years. Study endpoint was occurrence of symptomatic VTE.

RESULTS

Patients (n=1434) were followed over a median observation period of 729 days. VTE occurred in 107 (7.5%) patients. At study inclusion, 170 (11.9%) patients took statins. Simvastatin (n=96) and atorvastatin (n=48) were the most frequently prescribed statins. VTE occurred in 6 (3.5%) patients with statins. Patients with statins had a lower risk of VTE than patients without (subhazard ratio 0.43, 95% confidence interval 0.19 to 0.98; p=0.04). In competing risk analysis, the cumulative probability of VTE in patients with statins was 2.94% after 12 months and 3.54% after 24 months, compared to 7.13% and 8.13% in the group without statins (Gray's test: p=0.04).

CONCLUSION

This study provides observational evidence for an association between statin use and low risk of VTE in patients with cancer. The role of statins for prevention of cancer-associated VTE needs to be confirmed in randomized, controlled trials.

Effect of pitavastatin on vascular reactivity in hypercholesterolemic rabbits

Background

Pitavastatin is the newest statin available in Brazil and likely the one with fewer side effects. Thus, pitavastatin was evaluated in hypercholesterolemic rabbits in relation to its action on vascular reactivity.

Objective

To assess the lowest dose of pitavastatin necessary to reduce plasma lipids, cholesterol and tissue lipid peroxidation, as well as endothelial function in hypercholesterolemic rabbits.

Methods

Thirty rabbits divided into six groups (n = 5): G1 - standard chow diet; G2 - hypercholesterolemic diet for 30 days; G3 - hypercholesterolemic diet and after the 16^th day, diet supplemented with pitavastatin (0.1 mg); G4 - hypercholesterolemic diet supplemented with pitavastatin (0.25 mg); G5 - hypercholesterolemic diet supplemented with pitavastatin (0.5 mg); G6 - hypercholesterolemic diet supplemented with pitavastatin (1.0 mg). After 30 days, total cholesterol, HDL, triglycerides, glucose, creatine kinase (CK), aspartate aminotransferase (AST), alanine aminotransferase (ALT) were measured and LDL was calculated. In-depth anesthesia was performed with sodium thiopental and aortic segments were removed to study endothelial function, cholesterol and tissue lipid peroxidation. The significance level for statistical tests was 5%.

Results

Total cholesterol and LDL were significantly elevated in relation to G1. HDL was significantly reduced in G4, G5 and G6 when compared to G2. Triglycerides, CK, AST, ALT, cholesterol and tissue lipid peroxidation showed no statistical difference between G2 and G3-G6. Significantly endothelial dysfunction reversion was observed in G5 and G6 when compared to G2.

Conclusion

Pitavastatin starting at a 0.5 mg dose was effective in reverting endothelial dysfunction in hypercholesterolemic rabbits.

Statins and venous thromboembolic disease prophylaxis

Statins have dramatically improved the treatment of hyperlipidemia and cardiovascular disease through its inhibition of hydroxymethylglutaryl-coenzyme A reductase. Although its main effect has long been known, much is yet to be understood about the wide and varied pleiotropic properties of statins. Some studies have demonstrated that statins contain antiplatelet, antithrombotic, antiinflammatory, cardioprotective, and neuroprotective properties independent of their ability to lower plasma low-density lipoprotein cholesterol. More recently, statins have been used in novel ways in the treatment of Alzheimer disease, sepsis, pneumonia, and bacteremia. In 2000, it was first suggested that statins could decrease the incidence of venous thromboembolisms (VTEs). A recent publication showed that not only do statins lower the incidence of deep vein thrombosis and pulmonary embolism, but they do so in a dose-dependent manner. Although there is certainly strong evidence demonstrating that statins do indeed lower VTEs, the mechanism is not understood. Possible hypotheses include their antiinflammatory and antithrombotic properties. With only one randomized clinical trial available, further studies must be conducted before routinely recommending statins for prophylaxis of VTEs.

Statins, aspirin and risk of thromboembolic events in ovarian cancer patients

OBJECTIVES

Studies suggest that statins and low dose aspirin reduce risk of VTEs in the general population. We aimed to study the effect of these drugs on the incidence of VTEs in patients with ovarian cancer.

METHODS

Patients diagnosed with ovarian cancer between 2000 and 2011 were identified through the Clalit Health Services (CHS) chronic disease registry. Data were extracted from CHS database and from computerized pharmacy records. Use of medications was analyzed as a time dependent covariate in a Cox regression model.

RESULTS

Of 1746 patients 175 (10%) had a VTE during a median follow up of 3.13 years. 83 patients (5.6%) had a VTE within 2 years of diagnosis of ovarian cancer. Use of chemotherapy and stage 3 and 4 at presentation were associated with an increased risk for VTEs. Statins were used by 43.5% of the patients, and 32.3% used aspirin. Aspirin use was associated with a marginally significant reduction in incidence of VTEs within 2 years of diagnosis, HR 0.423 (95% CI 0.182-1.012, p-value 0.053). Statin use was not associated with risk of VTEs.

CONCLUSION

This is the first study looking at the effect of statins and aspirin on the incidence of VTEs in ovarian cancer patients. In our cohort, statins did not decrease the risk for a VTE and aspirin use was associated with a reduced risk which was marginally significant. Our results might be explained by use of low potency statins and by alternate mechanisms for VTE formation in cancer patients.

Antioxidant and antiplatelet effects of atorvastatin by Nox2 inhibition

In recent years, it became evident that reactive oxygen species (ROS) are implicated in the thrombotic process. Statins are lipid-lowering agents able to lower serum cholesterol levels and retard atherosclerotic complications and their clinical sequelae. There is evidence that, among statins, atorvastatin may exert antiplatelet effects by interfering with redox signaling. Recent studies demonstrated that atorvastatin possesses antiplatelet activity via inhibition of platelet formation of NADPH oxidase-derived ROS. This effect results in down-regulation of isoprostanes, which are pro-aggregating molecules, and up-regulation of nitric oxide, which is a platelet inhibitor; such changes occurred immediately after atorvastatin administration and were independent from lipid-lowering property. Experimental and clinical studies documented that statins possess antithrombotic effects, which may account for the reduction of thrombotic-related vascular outcomes. This has been evidenced in different cardiovascular clinical settings such as percutaneous coronary intervention (PCI), myocardial infarction (MI), and venous thrombosis. Future studies should be addressed to analyze if the antiplatelet effect of atorvastatin may preferentially occur at high dosage. Interestingly, the antiplatelet effects of statins could be useful in clinical settings where the clinical efficacy of aspirin and other antiplatelet drugs is still uncertain.

Statin therapy and levels of hemostatic factors in a healthy population: the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

HMG-CoA reductase inhibitors (statins) reduce the risk of venous thromboembolism (VTE) in healthy people. Statins reduce levels of inflammation biomarkers; however, the mechanism for the reduction in VTE risk is unknown.

AIM

In a large cohort of healthy people, we studied associations of statin use with plasma hemostatic factors related to VTE risk.

METHODS

Cross-sectional analyses were performed in the Multi-Ethnic Study of Atherosclerosis (MESA), a cohort study of 6814 healthy men and women aged 45-84 years, free of clinical cardiovascular disease at baseline; 1001 were using statins at baseline. Twenty-three warfarin users were excluded. Age, race and sex-adjusted mean hemostatic factor levels were compared between statin users and non-users, and multivariable linear regression models were used to assess associations of statin use with hemostatic factors, adjusted for age, race/ethnicity, education, income, aspirin use, hormone replacement therapy (in women), and major cardiovascular risk factors.

RESULTS

Participants using statins had lower adjusted levels of D-dimer (- 9%), C-reactive protein (- 21%) and factor VIII (- 3%) than non-users (P < 0.05). Homocysteine and von Willebrand factor levels were non-significantly lower with statin use. Higher fibrinogen (2%) and plasminogen activator inhibitor-1 (22%) levels were observed among statin users than among non-users (P < 0.05). Further adjustment for LDL and triglyceride levels did not attenuate the observed differences in these factors with statin use.

CONCLUSIONS

Findings of lower D-dimer, FVIII and C-reactive protein levels with statin use suggest hypotheses for mechanisms whereby statins might lower VTE risk. A prospective study or clinical trial linking these biochemical differences to VTE outcomes in statin users and non-users is warranted.

Prophylaxis of Thromboembolic Events in Patients with Nephrotic Syndrome

OBJECTIVE

To review published literature regarding use of strategies to prevent thrombotic events in patients with nephrotic syndrome (NS).

DATA SOURCES

The MEDLINE/PubMed, EMBASE, and Cochrane databases were queried from 1980 to December 2012 for articles in English using the search terms nephrotic syndrome, thrombosis, thromboembolism, anticoagulation, warfarin, heparin, low-molecular-weight heparin, enoxaparin, dalteparin, tinzaparin, statin, atorvastatin, fluvastatin, lovastatin, pitavastatin, pravastatin, rosuvastatin, simvastatin, aspirin, direct thrombin inhibitor, rivaroxaban, argatroban, lepirudin, bivalirudin, dabigatran, factor Xa inhibitor, fondaparinux, rivaroxaban, clopidogrel, ticlopidine, and prasugrel.

STUDY SELECTION AND DATA EXTRACTION

All relevant original studies, meta-analyses, systematic reviews, guidelines, and review articles were assessed for inclusion. References from pertinent articles were examined for additional content not found during the initial search.

DATA SYNTHESIS

NS leads to multiple complications, including hypercoagulability. A small prospective cohort study used enoxaparin for primary prophylaxis and demonstrated successful prevention of thrombotic events with minimal adverse events. Additional information has come in the form of decision analyses, which show potential decreased morbidity and mortality when primary prophylaxis for thrombotic events is used; however, all data have numerous limitations. Other strategies for thrombus prevention, including statins and antiplatelet agents, also have been investigated.

CONCLUSIONS

When patients with NS are admitted to the hospital, develop an acute medical illness, or acquire an additional thrombotic events risk factor such as surgery, active malignancy, or pregnancy, consideration for primary pharmacologic prophylaxis with appropriately dosed low-molecular-weight heparin or other indicated anticoagulant should include the potential for increased thrombotic events risk in this patient population. Consideration may also be given to the use of primary pharmacologic prophylaxis with low-molecular-weight heparin or oral vitamin K antagonist in patients with membranous nephropathy once the albumin level drops below 2.0–2.5 g/dL. Short-term use of pharmacologic prophylaxis during the first 6 months following diagnosis warrants further investigation.

Indications for platelet aggregation inhibitors after venous stents

Iliofemoral venous obstruction may arise from either primary compressive lesions or may be secondary to an episode of deep venous thrombosis. Regardless of aetiology, these lesions, either alone or in association with more distal reflux, may be responsible for lower extremity pain, swelling, and ulceration. Conventional surgical procedures for the treatment of iliofemoral venous obstruction have largely been supplanted by endovascular approaches relying on the deployment of venous stents. Large series have reported good technical and clinical results from venous stenting, particularly for primary lesions. However, early stent occlusions and late re-stenosis do occur. Although most of these appear related to technical factors, there is likely a role for pharmacological adjuncts in maintaining stent patency. The use of anticoagulants and antiplatelet agents is largely based on the underlying pathophysiology and extrapolation from arterial interventions, which likely are significantly different with respect to their pathophysiology and natural history. Although lacking substantial evidence demonstrating efficacy, the use of adjunctive antiplatelet agents in stents placed for primary lesions and consideration of anticoagulation for high-risk post-thrombotic lesions appears to be reasonable.

The statin-iron nexus: anti-inflammatory intervention for arterial disease prevention

OBJECTIVES

We postulated the existence of a statin-iron nexus by which statins improve cardiovascular disease outcomes at least partially by countering proinflammatory effects of excess iron stores.

METHODS

Using data from a clinical trial of iron (ferritin) reduction in advanced peripheral arterial disease, the Iron and Atherosclerosis Study, we compared effects of ferritin levels versus high-density lipoprotein to low-density lipoprotein ratios (both were randomization variables) on clinical outcomes in participants receiving and not receiving statins.

RESULTS

Statins increased high-density lipoprotein to low-density lipoprotein ratios and reduced ferritin levels by noninteracting mechanisms. Improved clinical outcomes were associated with lower ferritin levels but not with improved lipid status.

CONCLUSIONS

There are commonalities between the clinical benefits of statins and the maintenance of physiologic iron levels. Iron reduction may be a safe and low-cost alternative to statins.

Statins for the prevention of venous thromboembolism? a narrative review

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, is a substantial public health problem. The majority of VTE events are associated with transient periods of heightened risk, such as prolonged hospitalization, undergoing major surgery, experiencing trauma or lower extremity immobility, use of oral contraceptives, or having active cancer. Although pharmacologic thromboprophylaxis agents (eg, unfractionated heparin, low-molecular-weight heparins, warfarin, and novel oral anticoagulants) are effective, they remain underused, with concerns about increased bleeding risk often cited as a reason. The 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (ie, statins), although used primarily for lipid lowering and arterial thrombosis risk reduction, have pleiotrophic effects that affect coagulation and inflammation, and do not increase bleeding risk. There is emerging evidence to suggest that through these pleiotrophic effects, statins may be effective in reducing the incidence of VTE. This article summarizes the literature with regard to statins' effect on VTE and suggests that additional investigations are needed to assess a potential adjunctive role for primary VTE thromboprophylaxis.

Effect of statins on venous thromboembolic events: a meta-analysis of published and unpublished evidence from randomised controlled trials

BACKGROUND

It has been suggested that statins substantially reduce the risk of venous thromboembolic events. We sought to test this hypothesis by performing a meta-analysis of both published and unpublished results from randomised trials of statins.

METHODS AND FINDINGS

We searched MEDLINE, EMBASE, and Cochrane CENTRAL up to March 2012 for randomised controlled trials comparing statin with no statin, or comparing high dose versus standard dose statin, with 100 or more randomised participants and at least 6 months' follow-up. Investigators were contacted for unpublished information about venous thromboembolic events during follow-up. Twenty-two trials of statin versus control (105,759 participants) and seven trials of an intensive versus a standard dose statin regimen (40,594 participants) were included. In trials of statin versus control, allocation to statin therapy did not significantly reduce the risk of venous thromboembolic events (465 [0.9%] statin versus 521 [1.0%] control, odds ratio [OR] = 0.89, 95% CI 0.78-1.01, p = 0.08) with no evidence of heterogeneity between effects on deep vein thrombosis (266 versus 311, OR 0.85, 95% CI 0.72-1.01) and effects on pulmonary embolism (205 versus 222, OR 0.92, 95% CI 0.76-1.12). Exclusion of the trial result that provided the motivation for our meta-analysis (JUPITER) had little impact on the findings for venous thromboembolic events (431 [0.9%] versus 461 [1.0%], OR = 0.93 [95% CI 0.82-1.07], p = 0.32 among the other 21 trials). There was no evidence that higher dose statin therapy reduced the risk of venous thromboembolic events compared with standard dose statin therapy (198 [1.0%] versus 202 [1.0%], OR = 0.98, 95% CI 0.80-1.20, p = 0.87). Risk of bias overall was small but a certain degree of effect underestimation due to random error cannot be ruled out. Please see later in the article for the Editors' Summary.

CONCLUSIONS

The findings from this meta-analysis do not support the previous suggestion of a large protective effect of statins (or higher dose statins) on venous thromboembolic events. However, a more moderate reduction in risk up to about one-fifth cannot be ruled out.