Statins, inflammation and deep vein thrombosis: a systematic review

Statins for the primary prevention of venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) involves the formation of a blood clot in a vein, and includes deep venous thrombosis (DVT) or pulmonary embolism (PE). The annual incidence for VTE varies from 0.75 to 2.69 per 1000 individuals, with about 40 million people worldwide impacted by VTE. Statins, 3-hydroxy-3-methylglutaryl (HMG)-coenzyme A (CoA) reductase inhibitors, inhibit cholesterol biosynthesis and display several vascular-protective effects, including antithrombotic properties. However, the potential role of statins in the primary prevention of VTE is still not clear.

OBJECTIVES

To evaluate the benefits and risks of statins in preventing venous thromboembolism (VTE) in individuals with no prior history of VTE.

SEARCH METHODS

We used standard Cochrane search methods. The search was last updated on 13 March 2023.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) comparing statins with any control intervention (including placebo and usual care) in healthy individuals or participants with conditions other than VTE. There were no restrictions on the dose, duration, route, or timing of statins.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were VTE, DVT, and PE. Our secondary outcomes were serious adverse events, adverse events, and mortality. We used the trial sequential analysis (TSA) method to judge whether the evidence was sufficient, and we used the GRADE approach to assess the certainty of the evidence for each outcome.

MAIN RESULTS

We included 27 RCTs involving 122,601 adults (aged 18 years and above) who were healthy, had various medical conditions (e.g. hypercholesterolemia), or were at risk for cardiovascular disease. Both males and females were included in all studies. Two studies focused solely on participants over 60 years of age. We deemed four studies to have a low risk of bias overall, while 19 were at high risk of bias, and four were unclear. The 27 studies compared use of statins versus placebo or usual care in individuals who had never experienced VTE. The statins used in the studies were atorvastatin, rosuvastatin, pravastatin, lovastatin, fluvastatin, and simvastatin. Twenty-three studies followed up participants for over a year, with six of those extending follow-ups for over five years. Twenty-five studies were based in hospitals, and 24 studies were funded by industry. Only one study used VTE as a primary endpoint. The median incidence of VTE in the statins group was 0.72% (ranging from 0% to 10.53%), and in the control group it was 0.89% (ranging from 0% to 6.83%). Our pooled analysis of the 27 studies showed that, relative to control groups, statins may slightly reduce the overall incidence of VTE (odds ratio (OR) 0.86, 95% confidence intervals (CI) 0.76 to 0.98; 27 studies, 122,601 participants; low-certainty evidence). Of the statins we evaluated, only rosuvastatin seemed to be associated with a reduced incidence of VTE, albeit the reduction in incidence was very small. The evidence did not clearly indicate a difference between groups in the incidence of DVT (OR 0.70, 95% CI 0.41 to 1.18; six studies, 40,305 participants; low-certainty evidence), PE (OR 0.83, 95% CI 0.46 to 1.52; five studies, 28,427 participants; low-certainty evidence), or myopathy (OR 1.10, 95% CI 0.83 to 1.45; 10 studies, 75,551 participants; low-certainty evidence). Nonetheless, statin use might slightly decrease the incidence of any serious adverse event (OR 0.95, 95% CI 0.91 to 0.99; 13 studies, 67,020 participants; low-certainty evidence) and any death (OR 0.90, 95% CI 0.86 to 0.95; 24 studies, 116,761 participants; low-certainty evidence), compared to control.

AUTHORS' CONCLUSIONS

Using statins for the primary prevention of VTE may slightly reduce the incidence of VTE and all-cause mortality. However, this effect is likely too weak to be considered significant. Statin use may not decrease the occurrence of DVT and PE. The current evidence is insufficient to draw strong conclusions because of the risk of bias in the studies, imprecision in the effect estimates, and potential publication bias. More evidence from well conducted and fully reported RCTs is needed to assess the preventive effects of different types of statins, as well as the effects of different dosages and treatment durations in various populations.

Risk of Venous Thromboembolism in Statin Users Compared to Fibrate Users in the United Kingdom Clinical Practice Research Datalink (UK CPRD) GOLD

Background

A substantial proportion of adults receive statins for treatment of hypercholesterolemia and cardiovascular risk, and statins have been found to improve outcomes in this patient population. However, studies have not consistently demonstrated the potential benefits of statins in preventing venous thromboembolism (VTE). Therefore, we conducted this study to investigate this association.

Methods

We conducted a cohort analysis in a study sample comprised of 40-79-year-old patients with hyperlipidemia who received at least one fibrate or statin prescription between January 1995 and December 2018 in the United Kingdom Clinical Practice Research Datalink (CPRD) GOLD. We evaluated the association between statin use and incident unprovoked VTE, compared to fibrate use, an active comparator, using Kaplan-Meier (KM) analysis, Poisson regression (with and without propensity score matching), and inverse probability of treatment weights (IPTW) marginal structural models (MSM).

Results

In this cohort of 166,292 patients with hyperlipidemia, 0.81% (N=1,353) developed incident unprovoked VTE. In analyses using the KM method, patients who received statins had a slightly lower risk of VTE compared to those who received fibrates (Log rank test: p=0.0524). The adjusted incident rate ratio (95% CI) for VTE, calculated using Poisson regression, controlling for serum cholesterol and other baseline covariates, in patients prescribed statins compared to fibrates was 0.77 (0.45-1.33) in the full cohort, 0.74 (0.38-1.45) in the propensity score matched analysis, and 0.51 (95% conservative CI: 0.34-0.76) in the IPTW MSM analysis.

Conclusion

While the magnitude of effect varied across the different analytic methods, there is consistent evidence for a protective effect of statin use on the occurrence of unprovoked VTE.

Dispensed prescription medications and short-term risk of pulmonary embolism in Norway and Sweden

Scandinavian electronic health-care registers provide a unique setting to investigate potential unidentified side effects of drugs. We analysed the association between prescription drugs dispensed in Norway and Sweden and the short-term risk of developing pulmonary embolism. A total of 12,104 pulmonary embolism cases were identified from patient- and cause-of-death registries in Norway (2004-2014) and 36,088 in Sweden (2005-2014). A case-crossover design was used to compare individual drugs dispensed 1-30 days before the date of pulmonary embolism diagnosis with dispensation in a 61-90 day time-window, while controlling for the receipt of other drugs. A BOLASSO approach was used to select drugs that were associated with short-term risk of pulmonary embolism. Thirty-eight drugs were associated with pulmonary embolism in the combined analysis of the Norwegian and Swedish data. Drugs associated with increased risk of pulmonary embolism included certain proton-pump inhibitors, antibiotics, antithrombotics, vasodilators, furosemide, anti-varicose medications, corticosteroids, immunostimulants (pegfilgrastim), opioids, analgesics, anxiolytics, antidepressants, antiprotozoals, and drugs for cough and colds. Mineral supplements, hydrochlorothiazide and potassium-sparing agents, beta-blockers, angiotensin 2 receptor blockers, statins, and methotrexate were associated with lower risk. Most associations persisted, and several additional drugs were associated, with pulmonary embolism when using a longer time window of 90 days instead of 30 days. These results provide exploratory, pharmacopeia-wide evidence of medications that may increase or decrease the risk of pulmonary embolism. Some of these findings were expected based on the drugs' indications, while others are novel and require further study as potentially modifiable precipitants of pulmonary embolism.

Predictive factors of postoperative complications related to free flap reconstruction in head and neck cancer patients admitted to intensive care unit: a retrospective cohort study

BACKGROUND

The epidemiology and risk factors for postoperative complications related to free flap reconstruction in head and neck cancer patients admitted to the Intensive Care Unit (ICU) are unknown.

METHODS

We performed a retrospective cohort study of patients with free flap reconstruction of head and neck cancer between September 2015 and April 2023 admitted to the ICU of Beijing Tongren Hospital. The univariate and multivariate analyses were used to explore the risk factors for postoperative complications related to free flap reconstruction admitted to ICU, including flap necrosis, bleeding, fistula, and infection.

RESULTS

A total of 239 patients were included in this study, and 38 (15.9%) patients had postoperative complications related to free flap reconstruction. The median length of ICU stay was 1 day (interquartile range, 1-2 days). Multivariate analysis found that low BMI (P < 0.001), high postoperative CRP (P = 0.005), low hemoglobin (P = 0.012), and inadequate fluid intake (P < 0.05) were independent risk factors for complications.

CONCLUSIONS

Postoperative complications related to free flap reconstruction were common in this ICU population. Careful fluid management and monitoring of CRP and hemoglobin levels may reduce complications.

Association between the use of statins and in-hospital mortality risk in patients with sepsis-induced coagulopathy during ICU stays: a study based on medical information mart for intensive care database

BACKGROUND

The objective of this study was to explore the correlation between statin administration in the intensive care unit (ICU) setting and the in-hospital mortality risk of patients suffering from sepsis-induced coagulopathy (SIC).

METHODS

Utilizing a retrospective cohort study design, this investigation collected data from the Medical Information Mart for Intensive Care (MIMIC)-IV spanning 2008 to 2019. The diagnosis of SIC was established based on a SIC score of 4 or above. Statin usage during the ICU period was extracted from the prescription records based on the keywords of statin medications. The primary endpoint analyzed was the in-hospital mortality within the ICU, characterized by any death occurring during the ICU admission.

RESULTS

During the follow-up, which had a median duration of approximately 7.28 days, 18.19% of the 4,777 SIC patients died in the ICU. Statin was linked with a decrease in the risk of in-hospital mortality for SIC patients in the ICU [hazard ratio (HR): 0.73, 95% confidence interval (CI): 0.60-0.89, P = 0.002]. Relative to rosuvastatin, the use of atorvastatin (HR: 0.54, 95% CI: 0.34-0.85, P = 0.008) or simvastatin (HR: 0.55, 95% CI: 0.33-0.92, P = 0.024), as well as combinations of multiple statins (HR: 0.36, 95% CI: 0.15-0.86, P = 0.022), was associated with a reduction in ICU in-hospital mortality risk. Subgroup analysis also suggested that the use of atorvastatin, simvastatin, or a combination of statins had an advantage over rosuvastatin in reducing ICU in-hospital mortality in SIC patients older than 65 years of age or SIC patients with respiratory failure or cardiogenic shock (all P < 0.05).

CONCLUSION

The present study supports the potential benefits of statin use in mortality in SIC patients during ICU stays. The study encourages clinicians to consider the benefits of statins and supports the ongoing exploration of statins for enhanced outcomes in critical care settings.

Acute Pulmonary Embolism and Immunity in Animal Models

Venous thromboembolism, encompassing acute pulmonary embolism (APE) and deep vein thrombosis (DVT), is a potentially fatal disease with complex pathophysiology. Traditionally, the Virchow triad provided a framework for understanding the pathogenic contributors to thrombus formation, which include endothelial dysfunction, alterations in blood flow and blood hypercoagulability. In the last years, it has become apparent that immunity plays a central role in thrombosis, interacting with classical prothrombotic mechanisms, oxidative stress and vascular factors. Thrombosis amplifies inflammation, and exaggerated inflammatory processes can trigger thrombosis mainly due to the activation of leukocytes, platelets, and endothelial cells. APE-related endothelium injury is a major trigger for immune system activation. Endothelium is also a key component mediating inflammatory reaction and it is relevant to maintain vascular permeability. Exaggerated right ventricular wall stress and overload, with coexisting systemic hypotension and hypoxemia, result in myocardial injury and necrosis. Hypoxia, tissue factor activation and cytokine storm are engaged in the thrombo-inflammatory processes. Thrombus development is characterized by inflammatory state vascular wall caused mainly by an early extravasation of leukocytes and intense selectins and cytokines production. Nevertheless, immunity of DVT is well described, little is known about potential chemokine and cellular differences between thrombus that develops in the vein and thrombus that detaches and lodges in the pulmonary circulation being a cause of APE. There is a paucity of data considering inflammatory state in the pulmonary artery wall during an acute episode of pulmonary embolism. The main aim of this review is to summarize the knowledge of immunity in acute phase of pulmonary embolism in experimental models.

Statins and Venous Thromboembolic Disease - Where are we Now?

Classical risk factors for atherosclerosis also play a role in the pathogenesis of venous thromboembolism (VTE). Low-density lipoprotein cholesterol has prothrombotic and endothelium- deteriorating effects which are not limited to the arterial system. The association between hypercholesterolemia and VTE has been established, but the benefits of statins in the prevention of VTE assessed by observation studies seemed equivocal. The large, randomized trial Justification for the Use of Statins in Prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER) recorded the occurrence of VTE as a protocol-specified endpoint and reported a reduced incidence of VTE among subjects taking 20 mg of rosuvastatin daily vs placebo (hazard ratio 0.57; 95% confidence interval 0.37-0.86; p=0.007). Similar results were confirmed by meta-analyses of observation studies and randomized trials. Recently, a Mendelian randomization study that took the presence of gene variants coding for less efficient hydroxymethyl-glutaryl coenzyme A reductase activity as a proxy for statin treatment, confirmed a small, but significant negative association between the score of selected genetic polymorphisms and the incidence of VTE. However, since the protective effects of statins are limited, they should not be substituted for guideline-recommended VTE prophylaxis or anticoagulation treatment.

SNP (A > G - rs13057211) but not GT(n) polymorphism in HMOX-1 promotor gene is associated with COVID-19 mortality

INTRODUCTION

COVID-19 causes severe inflammatory respiratory distress syndrome. The global pandemic caused millions of cases of morbidity and mortality worldwide. Patients may present with variable symptoms including dyspnea, fever, and GIT manifestations. The HMOX-1 gene is located on the long (q) arm of chromosome 22 at position 12.3. HMOX-1 is expressed in all mammalian tissues at basal levels and is considered as a stress response enzyme. HMOX-1 has a specific polymorphic site with variable GT(n) repeats at the promotor region. Several authors evaluated the HMOX-1 GT(n) promoter polymorphism in different inflammatory conditions. We evaluated HMOX-1 promoter polymorphism in relation to serum Hemoxygenase level and inflammatory makers (CRP, Ferritin, PCT, IL-6 and D-dimer) in patients affected by SARS-COV-2 disease.

SUBJECTS AND METHODS

Ninety patients confirmed to be infected with COVID-19 were followed up till the study end point (recovery and discharge or death). HMOX-1 promotor GT(n) polymorphism was evaluated using Sanger sequencing. HMOX-1 enzyme serum level was measured by ELISA and the level of different inflammatory markers was assessed by available commercial kits.

RESULTS

A novel Single nucleotide polymorphism (SNP) (A > G) - rs13057211 in the GT(n) region of HMOX-1 promoter gene was found in 40 (61.5%) COVID-19 patients out of the studied 65 patients. This (A > G) SNP was associated with higher mortality rate in COVID-19 as it was detected in 27 patients (75% of the patients who succumbed to the disease) (p = 0.021, Odds ratio = 3.7; 95% CI:1.29-10.56). Serum IL-6 (Interleuken-6) was positively correlated the length of Hospital Stay (LOHS) and procalcitonin (PCT); (p = 0.014, r: 0.651 and p < 0.001, r:0.997) respectively while negatively correlated with levels of HMOX-1 enzyme serum level (p = 0.013, r: -0.61). CRP correlated positively with LOHS (p = 0.021, r = 0.4), PCT (p = 0.044, r = 0.425) and age (p < 0.001, r = 0.685). Higher levels of D-Dimer and PCT were observed in patients with the long repeat. There was no significant difference between patients who recovered and those who died from COVID-19 as regards HMOX-1 level and GT(n) polymorphism.

CONCLUSION

We report a novel SNP (A > G, rs13057211) in the GT(n) region of HMOX-1 promoter gene that was associated with mortality in COVID-19 patients, however no significant difference was found in HMOX-1 serum level or HMOX-1 (GT)n repeats within the studied groups.

Elderly hip fracture patients with isolated calf muscle vein thrombosis are more likely to have suffered an intertrochanteric fracture and be hypertensive

PURPOSE

This study aimed to characterize the preoperative deep venous thrombosis (DVT) of lower extremity by locations and evaluate the diagnostic ability of plasma D-dimer level in elderly patients with hip fracture.

METHOD

This retrospective study reviewed the elderly patients presenting with a hip fracture definitely undergoing surgical treatment and identified those who had preoperative DVT. Data on demographics, lifestyle habits, comorbidities and laboratory indexes were extracted and collected. Four groups were divided by presence and locations of thrombi: non-DVT (controls), isolated calf muscle vein thrombosis (CMVT), deep calf vein thrombosis (DCVT) and proximal DVT group. The comparisons were conducted between either DVT group or the non-DVT group. Receiver operating characteristic (ROC) curve and the area under the curve (AUC) were used for determining the diagnostic ability of D-dimer for each group.

RESULTS

Among 951 eligible patients included, 298 (31.3%) were found have preoperative DVT. Compared to non-DVT group, patients with CMVT had significantly lower albumin and hemoglobin concentration, more likely an intertrochanteric fracture and a higher prevalence of hypertension (P = 0.001, 0.006, 0.002 and 0.024, respectively); DCVT group was not observed to be significantly different in terms of any variables (all P > 0.05); and proximal DVT group had older age and more patients ≥ 80 years, lower albumin and hemoglobin concentration, higher prevalence of hypertension, more likely an intertrochanteric fracture, extended time from injury to imaging examination and higher age-adjusted Charlson comorbidity index (ACCI) (all P < 0.05). D-dimer demonstrated nonsignificant diagnostic ability for CMVT and DCVT, and a significant but poor ability for proximal DVT (AUC, 0.621; 95% CI 0.542-0.710; P = 0.011).

CONCLUSION

Varying characteristics were found among preoperative DVT stratified by locations after elderly hip fractures, and D-dimer level demonstrated no or poor diagnostic ability for DVTs by locations. Level of evidence level III, diagnostic. Trial registration statement Not applicable.

Predicting thrombotic cardiovascular outcomes induced by waterpipe-associated chemicals using comparative toxicogenomic database: Genes, phenotypes, and pathways

Hookah, or waterpipe, is a tobacco smoking device that has gained popularity in the United States. A growing body of evidence demonstrates that waterpipe smoke (WPS) is associated with various adverse effects on human health, including infectious diseases, cancer, and cardiovascular diseases (CVDs), particularly thrombotic events. However, the molecular mechanisms through which WPS contributes to disease development remain unclear. In this study, we utilized an analytical approach based on the Comparative Toxicogenomics Database (CTD) to integrate chemical, gene, phenotype, and disease data to predict potential molecular mechanisms underlying the effects of WPS, based on its chemical and toxicant profile. Our analysis revealed that CVDs were among the top disease categories with regard to the number of curated interactions with WPS chemicals. We identified 5674 genes common between those modulated by WPS chemicals and traditional tobacco smoking. The CVDs with the most curated interactions with WPS chemicals were hypertension, atherosclerosis, and myocardial infarction, whereas "particulate matter", "heavy metals", and "nicotine" showed the highest number of curated interactions with CVDs. Our analysis predicted that the potential mechanisms underlying WPS-induced thrombotic diseases involve common phenotypes, such as inflammation, apoptosis, and cell proliferation, which are shared across all thrombotic diseases and the three aforementioned chemicals. In terms of enriched signaling pathways, we identified several, including chemokine and MAPK signaling, with particulate matter exhibiting the most statistically significant association with all 12 significant signaling pathways related to WPS chemicals. Collectively, our predictive comprehensive analysis provides evidence that WPS negatively impacts health and offers insights into the potential mechanisms through which it exerts these effects. This information should guide further research to explore and better understand the WPS and other tobacco product-related health consequences.

The effectiveness of atorvastatin for the prevention of deep vein thrombosis in cancer patients undergoing chemotherapy : A randomised controlled trial: open label

BACKGROUND

Deep vein thrombosis (DVT) is a common complication in cancer. Although thromboprophylaxis in cancer patients is recommended by the guidelines, clinicians' use of thromboprophylaxis remains limited due to cost, bleeding complications, and reluctance to give injectable anticoagulants. Inflammation plays essential roles in the pathogenesis of cancer-associated thrombosis. Owing to its ability to decrease proinflammatory cytokines, statins have anti-inflammatory properties. Thus, statins can be possibly utilized as thromboprophylaxis therapy in cancer patients undergoing chemotherapy.

OBJECTIVE

To compare the effectiveness of atorvastatin and rivaroxaban for DVT prevention in high-risk thrombosis patients with cancer undergoing chemotherapy.

METHODS

Double-blind, randomized controlled trial involving cancer patients with high-risk of thrombosis undergoing chemotherapy. We randomly assigned patients without deep-vein thrombosis at screening to receive atorvastatin 20 mg or rivaroxaban 10 mg daily for up to 90 days. Doppler ultrasonography was performed 90 days following chemotherapy to diagnose DVT. Average cost-effectiveness analysis was performed to analyze the cost of atorvastatin compared to rivaroxaban.

RESULTS

Of the eighty six patients who underwent randomization, primary efficacy end point was observed in 1 of 42 patients (2.3%) in the atorvastatin group and in 1 of 44 (2.2%) in the rivaroxaban group (Odds Ratio [OR], 0.953; 95% confidence interval [CI], 0.240 to 3.971; p = 1.000). There was a significant difference in the incidence of major bleeding, 2 of 42 patients (4.8%) in the atorvastatin group and 12 of 44 (27.3%) in the rivaroxaban group (OR, 0.257; 95% CI, 0.07 to 0.94; p = 0.007). The average cost-effectiveness ratio of using atorvastatin was lower than that of rivaroxaban.

CONCLUSION

Atorvastatin did not differ significantly from rivaroxaban in reducing the incidence of DVT, lower bleeding risk, and cost-effectiveness for thromboprophylaxis in high-risk thrombosis patients with cancer undergoing chemotherapy. The presence of limited statistical power and wide confidence intervals in this study needs further study to strengthen the efficacy of atorvastatin as DVT prophylaxis in cancer patients.

TRIAL REGISTRATION

ISRCTN71891829, Registration Date: 17/12/2020.

Statins and risk of venous thromboembolic diseases: A two-sample mendelian randomization study

BACKGROUND AND AIMS

In observational studies, statins have been suggested to have protective effects on venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE). To this aim, we performed a two-sample mendelian randomization (MR) analysis to determine whether these associations were causal.

METHODS AND RESULTS

Data on the single nucleotide polymorphisms (SNPs) related to statin medication were obtained from the FinnGen study, and data for VTE, PE and DVT of lower extremities (LEDVT) were from the UK Biobank study, respectively. Inverse variance weighted (IVW) method was used as the principal analysis of MR, and sensitivity analysis was performed to detect horizontal pleiotropy and heterogeneity. MR estimates showed an inverse causal association between statin medication and the risk of VTE (odds ratio [OR]: 0.999, 95% CI: 0.998-1.000, P = 0.004), PE (OR: 0.999, 95% CI: 0.999-1.000, P = 0.011) and LEDVT (OR: 0.999, 95% CI: 0.999-1.000, P = 0.008).

CONCLUSION

Our findings provide direct evidence that statins might decrease the risk of VTE, PE and LEDVT in agreement with observational studies. The specific mechanism of statin therapy for venous thromboembolism needs to be further studied.

Biological Actions, Implications, and Cautions of Statins Therapy in COVID-19

The Coronavirus Disease 2019 (COVID-19) showed worse prognosis and higher mortality in individuals with obesity. Dyslipidemia is a major link between obesity and COVID-19 severity. Statins as the most common lipid regulating drugs have shown favorable effects in various pathophysiological states. Importantly, accumulating observational studies have suggested that statin use is associated with reduced risk of progressing to severe illness and in-hospital death in COVID-19 patients. Possible explanations underlie these protective impacts include their abilities of reducing cholesterol, suppressing viral entry and replication, anti-inflammation and immunomodulatory effects, as well as anti-thrombosis and anti-oxidative properties. Despite these benefits, statin therapies have side effects that should be considered, such as elevated creatinine kinase, liver enzyme and serum glucose levels, which are already elevated in severe COVID-19. Concerns are also raised whether statins interfere with the efficacy of COVID-19 vaccines. Randomized controlled trials are being conducted worldwide to confirm the values of statin use for COVID-19 treatment. Generally, the results suggest no necessity to discontinue statin use, and no evidence suggesting interference between statins and COVID-19 vaccines. However, concomitant administration of statins and COVID-19 antiviral drug Paxlovid may increase statin exposure and the risk of adverse effects, because most statins are metabolized mainly through CYP3A4 which is potently inhibited by ritonavir, a major component of Paxlovid. Therefore, more clinical/preclinical studies are still warranted to understand the benefits, harms and mechanisms of statin use in the context of COVID-19.

Association of Gonadotropin-Releasing Hormone Therapies With Venous Thromboembolic Events in Patients With Prostate Cancer: A National Cohort Study

Although androgen deprivation therapy (ADT) has been proposed to be associated with a higher risk of venous thromboembolisms (VTEs), whether gonadotropin-releasing hormones (GnRHs), such as both agonists and antagonists, are also associated with VTEs remain unclear. Using the Taiwan Cancer Registry (TCR) linked with the National Health Insurance Research Database, we identified patients diagnosed with prostate cancer from 2008 to 2015. Patients who received GnRH were 1:1 propensity score matched with non-GnRH users by age and cancer stage at diagnosis and clinical stage. Cox regression analysis was applied to estimate the incidences of VTEs with death as a competing event at the 5-year follow-up. The VTE incidence among GnRH users was 1.13% compared with 0.98% among non-users. After adjusting with potential confounding factors, the risk of VTEs showed borderline statistical significance among GnRH users and non-users. Notably, in the subgroup analysis among patients receiving GnRH therapy, those younger than 70 years old or at an earlier stage (stage I/II) were at a higher risk of VTEs. Different from previous studies, our findings highlighted critical concerns regarding the cardiac safety of GnRH therapies in prostate cancer patients at a relatively younger age or at an earlier stage.

In Vivo Porcine Aged Deep Vein Thrombosis Model for Testing Ultrasound-based Thrombolysis Techniques

As blood clots age, many thrombolytic techniques become less effective. To fully evaluate these techniques for potential clinical use, a large animal aged-clot model is needed. Previous minimally invasive attempts to allow clots to age in an in vivo large animal model were unsuccessful because of the clot clearance associated with relatively high level of cardiac health of readily available research pigs. Prior models have thus subsequently used invasive surgical techniques with the associated morbidity, animal stress and cost. We propose a method for forming sub-acute venous blood clots in an in-vivo porcine model. The age of the clots can be controlled and varied. By using an intravenous scaffold to anchor the clot to the vessel wall during the aging process, we can show that sub-acute clots can consistently be formed with a minimally invasive, percutaneous approach. The clot formed in this study remained intact for at least 1 wk in all subjects. Therefore, we established a new minimally invasive, large animal aged-clot model for evaluation of thrombolytic techniques.

Effects of statins in primary and secondary prevention for venous thromboembolism events: A meta analysis

OBJECTIVE

The associations between statins use and incidence or recurrence of venous thromboembolism (VTE) are controversial. We aimed to conduct a meta-analysis to reconcile the conflicting results.

METHODS

We searched PubMed, Embase and Cochrane Library for studies published from database inception until May 31, 2021. Cohort studies and Randomized Controlled Trials that reported incidence or recurrence of VTE using statins compared with placebo or non-statins were included for meta-analysis.

RESULTS

A total of 43 studies comprising over 8.6 million participants were included for analysis. The median follow-up duration was 38.1 months. Compared with no statins treatment, statins appeared to have a protective effect in primary prevention of VTE (RR 0.78, 95% CI 0.72-0.85), but significant heterogeneity was found among included studies (I² = 81%). Statins was also associated with a 26% reduced risk of recurrent VTE (RR 0.74, 95% CI 0.70-0.78), even in patients receiving anticoagulant therapy (RR 0.77, 95% CI 0.65-0.92). In patients with a history of VTE, statins was associated with a reduced risk of bleeding and all cause mortality. The NNT of statins to prevent one case of VTE in the cancer population, and one case of recurrent VTE in patients with a history of VTE was 103.1 and 90.7 person-years respectively.

CONCLUSION

In high-risk patients, statins treatment may reduce the incidence of VTE. Statins can also reduce the risk of recurrent VTE and all-cause mortality in patients with a history of VTE.

Exact Association Between Preoperative Blood Viscosity and Postoperative Deep Venous Thrombosis Risk in Knee Osteoarthritis Patients: A 10-Year Retrospective Study

Several lines of evidence have suggested a sustainable relationship between blood viscosity (BV) and deep vein thrombosis (DVT). But there was a lack of data on the association of preoperative BV and postoperative acute DVT. For patients who accepted total knee arthroplasty (TKA) caused by primary knee osteoarthritis (KOA), this study tried to investigate whether preoperative BV relevant parameters might affect DVT risk following TKA. We reviewed a total of 750 consecutive KOA patients treated by unilateral TKA in our hospital from March 2010 to May 2020. All patients undergoing TKA were routinely examined by the color Doppler ultrasound on the third postoperative day and were assigned into DVT and non-DVT groups. Statistical comparisons of BV relevant parameters which mainly including whole BV (low, midst, and high shear rates), plasma viscosity, whole blood reductive viscosity (BRV; low, midst, and high shear rates) were made comprehensively. It could be found that low whole BRV (low shear rate) before TKA was significantly related to postoperative DVT risk in all patients, especially in female patients after stratifying by gender (p < .05). Our results implied that low whole BRV might be a remarkable risk factor of DVT in primary KOA patients after TKA. Timely and effective DVT prophylaxis for these patients is much required.

Expression and role of interleukin-1β and associated biomarkers in deep vein thrombosis

Lower extremity deep vein thrombosis (DVT) is a common peripheral vascular disease, in which inflammation plays an important role. The aim of the present study was to investigate the expression and role of inflammatory factors in DVT. A rat model of venous thrombosis of the lower extremities was established through venous ligation surgery. The rats were examined at 2, 8, 24, 48 and 72 h after the induction of inferior venous stenosis and compared with control and sham surgery groups. The serum levels of interleukin-1β (IL-1β), tissue factor (TF) and xanthine oxidase (XOD) were measured using ELISAs. The morphology of the DVT tissue was observed by hematoxylin and eosin staining. Circulating endothelial cells (CECs) in peripheral blood were counted by flow cytometry. Reverse transcription-quantitative PCR and western blotting were used to detect mRNA and protein expression, respectively. The serum levels of IL-1β, TF and XOD exhibited no significant differences between the control and sham surgery groups. However, those in the rat model of DVT presented an upward trend from 2 to 24 h and peaked at 24 h, with a significant difference from the respective levels in the control and sham surgery groups. The histopathological analysis revealed the presence of red and mixed thrombi in the rats 2-48 h following the induction of inferior venous stenosis group with inflammatory cell infiltration in the vascular wall. Thrombus formation was evident after 72 h. While significant difference was observed in the number of CECs in the peripheral blood between the control and sham surgery groups, the number of peripheral blood CECs in the rats with inferior venous stenosis group increased from 8 to 72 h, with significant differences among these groups. The mRNA levels of IL-1β, TF, XOD and NF-κB in the tissues peaked at 24 h, with significant differences compared with those in the control and sham surgery groups. In addition, the protein expression level of NF-κB increased from 2 to 72 h. In conclusion, these results suggest that the high expression of IL-1β, TF, XOD and NF-κB may promote thrombus formation.

Atorvastatin therapy in COVID-19 adult inpatients: A double-blind, randomized controlled trial

Introduction

Efficacious therapies are urgently required to tackle the coronavirus disease 2019 (COVID-19). This trial aims to evaluate the effects of atorvastatin in comparison with standard care for adults hospitalized with COVID-19.

Methods

We conducted a randomized controlled clinical trial on adults hospitalized with COVID-19. Patients were randomized into a treatment group receiving atorvastatin + lopinavir/ritonavir or a control group receiving lopinavir/ritonavir alone. The primary outcome of the trial was the duration of hospitalization. The secondary outcomes were the need for interferon or immunoglobulin, receipt of invasive mechanical ventilation, and O2 saturation (O2sat), and level of C-reactive protein (CRP) which were assessed at the onset of admission and on the 6th day of treatment.

Results

Forty patients were allocated and enrolled in the study with a 1 to 1 ratio in atorvastatin + lopinavir/ritonavir and lopinavir/ritonavir groups. Clinical and demographic characteristics were similar between the two groups. CRP level was significantly decreased in the lopinavir/ritonavir + atorvastatin group (P < 0.0001, Cohen’s d = 0.865) so that there was a significant difference in CRP level on the 6th day between the two groups (P = 0.01). Nevertheless, there was no significant difference in O2sat on day 6. Although the duration of hospitalization in the lopinavir/ritonavir + atorvastatin group was significantly reduced compared to the control group (P = 0.012), there was no significant difference in the invasive mechanical ventilation reception and the need for interferon and immunoglobulin.

Conclusion

Atorvastatin + lopinavir/ritonavir may be more effective than lopinavir/ritonavir in treating COVID-19 adult hospitalized patients.

Effects of aspirin and statin use on venous thromboembolism prophylaxis and survival in patients with endometrial cancer

INTRODUCTION

Acetylsalicylic acid (aspirin) and statins are commonly used to manage and prevent cardiovascular diseases. Recent studies have suggested the benefits of aspirin or statin use in venous thromboembolism (VTE) prophylaxis and survival outcome improvement in women with endometrial cancer.

AREAS COVERED

In this study, we reviewed the effects of aspirin or statin use on VTE prophylaxis and survival outcome in women with endometrial cancer.

EXPERT OPINION

Among women with endometrial cancer, aspirin use exerted a modest effect on VTE prophylaxis, whereas statin use was associated with a decreased prevalence of VTE, especially in women with obesity and type II cancer, compared with those in non-users. Aspirin use improved cause-specific survival in women with endometrial cancer, aged less than 60 years, who were obese and presented with type I cancer. Statin use was associated with better cause-specific survival in women with type II cancer. The combination of aspirin and statins may be the most effective strategy in improving on VTE prophylaxis and survival outcomes in obese women with type II cancer. Targeting of the appropriate population with endometrial cancer may enhance the efficacy of aspirin or statins on VTE prophylaxis and survival outcomes in women with endometrial cancer.

Usefulness of MCP-1 Chemokine in the Monitoring of Patients with Coronary Artery Disease Subjected to Intensive Dietary Intervention: A Pilot Study

Monocyte chemotactic protein-1 (MCP-1) plays an important role in the entire atherosclerotic process, from atherogenesis to destabilisation of the atherosclerotic plaque. The purpose of this study is to evaluate the effect of the dietary approaches to stop hypertension (DASH) diet in patients with coronary artery disease on the MCP-1 plasma concentration and to evaluate the potential usefulness of this chemokine as a marker of change in the volume and composition of coronary plaque. Material and method. As part of the dietary intervention to stop coronary atherosclerosis in computed tomography (DISCO-CT) study, patients were randomised to an intervention group (n = 40) in which the DASH diet was introduced, and to a control group (n = 39) with no dietary intervention. In the DASH group, dietary counselling was provided at all follow-up visits within 12 months of the follow-up period. MCP-1 plasma concentration was determined using enzyme-linked immunosorbent assay (ELISA). Coronary plaque analysis was performed using a semi-automated plaque analysis software system (QAngioCT, Medis, The Netherlands). Results. In the DASH group, MCP-1 plasma concentration significantly decreased by 34.1 pg/mL (p = 0.01), while in the control group, the change in MPC-1 was not significant. Significant inverse correlations were revealed for the change in MCP-1 plasma concentration and change in the consumption of vitamin C and dietary fibre both in the DASH (r = −0.519, p = 0.0005; r = −0.353, p = 0.025, respectively) and in the control group (r = −0.488 p = 0.001; r = −0.502, p = 0.001, respectively). In patients with the highest decrease in percent atheroma volume (PAV), a significant positive correlation was observed between the change in MCP-1 plasma concentration and changes in PAV (r = 0.428, p = 0.033) and calcified plaque component (r = 0.468, p = 0.018), while the change in noncalcified plaque component correlated inversely with change in MCP1 (r = −0.459, p = 0.021). Conclusion. Dietary intervention based on the DASH diet model reduces the MCP-1plasma concentration, mostly due to an increased intake of plant-derived, fibre-rich foods and antioxidants. The change in MCP-1 plasma concentration seems to reflect changes in the atheroma volume and proportions between the calcified and non-calcified plaque elements.

Evaluation of Deep Vein Thrombosis Risk Factors After Arthroscopic Posterior Cruciate Ligament Reconstruction: A Retrospective Observational Study

We evaluated the risk factors of deep venous thrombosis (DVT) after knee arthroscopic posterior cruciate ligament (PCL) reconstruction in patients with only PCL injury. From August 2014 to December 2020, a total of 172 patients who had accepted knee arthroscopic PCL reconstruction underwent the color Doppler ultrasound of bilateral lower-extremities deep veins on 3 days postoperatively. Based on the inspection results, patients were divided into DVT group (18 males and 8 females, mean age 43.62 years) and non-DVT group (108 males and 38 females, mean age 33.96 years). The potential associations of DVT risk and age, gender, body mass index (BMI), diabetes, hypertension, smoking and other factors were analyzed. An old age (OR = 1.090; 95% CI = 1.025-1.158; P = 0.006), a high BMI (OR = 1.509; 95% CI = 1.181-1.929; P = 0.001) and an increased post-surgery D-dimer (OR = 5.034; 95% CI = 2.091-12,117; P ≤ 0.001) value were significantly associated with an elevated DVT risk after knee arthroscopic PCL reconstruction. Increased age, BMI, and postoperative D-dimer were risk factors of DVT following knee arthroscopic PCL reconstruction in patients with only PCL injury.

Metabolic Syndrome Increases Risk of Venous Thromboembolism Recurrence after Acute Pulmonary Embolism

Rationale: Metabolic syndrome (MetS), the clinical clustering of hypertension, dyslipidemia, insulin resistance, and abdominal obesity, has been associated with a prothrombotic and hypofibrinolytic state, although data linking MetS with venous thromboembolism (VTE) remain limited.Objectives: The aim of this study was to measure the prevalence of MetS in patients with pulmonary embolism (PE) across a large population and to examine its impact on VTE recurrence.Methods: This was a retrospective, population-based analysis using deidentified information from a large statewide database, the Indiana Network for Patient Care. All patients with an International Classification of Diseases-defined diagnosis of PE from 2004 to 2017 were included. We measured the frequency with which patients with PE carried a comorbid diagnosis of each MetS component. Multiple logistic regression analysis was performed with VTE recurrence as the dependent variable to test the independent effect of MetS diagnosis, with a statistical model using a directed acyclic graph to account for potential confounders and mediators. Kaplan-Meier curves were constructed to compare rates of VTE recurrence over time based on the presence or absence of MetS and its individual components.Results: A total of 72,936 patients were included in this analysis. The most common MetS component was hypertension with a prevalence of 59%, followed by hyperlipidemia (41%), diabetes mellitus (24%), and obesity (22%). Of these patients, 69% had at least one comorbid component of MetS. The overall incidence of VTE recurrence was 17%, increasing stepwise with each additional MetS component and ranging from 6% in patients with zero components to 37% in those with all four. Logistic regression analysis yielded an adjusted odds ratio of 3.03 (95% CI, 2.90-3.16) for the effect of composite diagnosis requiring at least three of the four components of MetS diagnosis on VTE recurrence.Conclusions: The presence of comorbid MetS in patients with PE is associated with significantly higher rates of VTE recurrence, supporting the importance of recognizing these risk factors and initiating appropriate therapies to reduce recurrence risk.

Metabolic syndrome increases risk of venous thromboembolism recurrence after acute deep vein thrombosis

An improved understanding of which patients are at higher risk of recurrent venous thromboembolism (VTE) is important to designing interventions to reduce degraded quality of life after VTE. Although metabolic syndrome (MetS), the clustering of hypertension, hyperlipidemia, diabetes mellitus, and obesity has been associated with a hypofibrinolytic state, data linking VTE recurrence with MetS remain limited. The purpose of this study was to measure the prevalence of MetS in patients with deep vein thrombosis (DVT) across a large population and determine its effect on VTE recurrence. This was a retrospective analysis of a large statewide database from 2004 to 2017. We measured the frequency with which patients with DVT carried a comorbid International Coding of Diseases diagnosis of MetS components. Association of MetS with VTE recurrence was tested with a multiple logistic regression model and VTE recurrence as the dependent variable. Risk of VTE recurrence conferred by each MetS component was assessed by Kaplan-Meier curves with the log-rank statistic. A total of 151 054 patients with DVT were included in this analysis. Recurrence of VTE occurred in 17% overall and increased stepwise with each criterion for MetS. All 4 components of MetS had significant adjusted odds ratios (OR) for VTE recurrence, with hyperlipidemia having the largest (OR, 1.8), representing the 4 largest ORs of all possible explanatory variables. All 4 MetS variables were significant on Kaplan-Meier analysis for recurrence of VTE. These data imply a role for appropriate therapies to reduce the effects of MetS as a way to reduce risk of VTE recurrence.

Antithrombotics and new interventions for venous thromboembolism: Exploring possibilities beyond factor IIa and factor Xa inhibition

Direct oral anti-activated factor X and antithrombin agents have largely replaced vitamin K antagonists as the standard of care in treatment of venous thromboembolism. However, gaps in efficacy and safety persist, notably in end-stage renal disease, implantable heart valves or assist devices, extracorporeal support of the circulation, and antiphospholipid syndrome. Inhibition of coagulation factor XI (FXI) emerges as a promising new therapeutic target. Antisense oligonucleotides offer potential advantages as a prophylactic or therapeutic modality, with one dose-finding trial in orthopedic surgery already published. In addition, monoclonal antibodies blocking activation and/or activity of activated factor XI are investigated, as are small-molecule inhibitors with rapid offset of action. Further potential targets include upstream components of the contact pathway such as factor XII, polyphosphates, or kallikrein. Finally, catheter-directed, pharmacomechanical antithrombotic strategies have been developed for high- and intermediate-risk pulmonary embolism, and large randomized trials aiming to validate their efficacy, safety, and prognostic impact are about to start.

Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Imaging Predicts Vein Wall Scarring and Statin Benefit in Murine Venous Thrombosis

BACKGROUND

The postthrombotic syndrome is a common, often morbid sequela of venous thrombosis (VT) that arises from thrombus persistence and inflammatory scarring of juxtaposed vein walls and valves. Noninvasive ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging can measure neutrophil inflammation in VT. Here, we hypothesized (1) early fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) VT inflammation can predict subsequent vein wall scarring (VWS) and (2) statin therapy can reduce FDG-PET VT inflammation and subsequent VWS.

METHODS

C57BL/6J mice (n=75) underwent induction of stasis-induced VT of the inferior vena cava or jugular vein. Inferior vena cava VT mice (n=44) were randomized to daily oral rosuvastatin 5 mg/kg or saline starting at day -1. Subgroups of mice then underwent FDG-PET/CT 2 days after VT induction. On day 14, a subset of mice was euthanized, and VWS was assessed via histology. In vitro studies were further performed on bone marrow-derived neutrophils.

RESULTS

Statin therapy reduced early day 2 FDG-PET VT inflammation, thrombus neutrophil influx, and plasma IL (interleukin)-6 levels. At day 14, statin therapy reduced VWS but did not affect day 2 thrombus mass, cholesterol, or white blood counts, nor reduce day 2 glucose transporter 1 or myeloperoxidase expression in thrombus or in isolated neutrophils. In survival studies, the day 2 FDG-PET VT inflammation signal as measured by mean and maximum standardized uptake values predicted the extent of day 14 VWS (area under the receiver operating characteristic curve =0.82) with a strong correlation coefficient (r) of r=0.73 and r=0.74, respectively. Mediation analyses revealed that 40% of the statin-induced VWS reduction was mediated by reductions in VT inflammation as quantified by FDG-PET.

CONCLUSIONS

Early noninvasive FDG-PET/CT imaging of VT inflammation predicts the magnitude of subsequent VWS and may provide a new translatable approach to identify individuals at risk for postthrombotic syndrome and to assess anti-inflammatory postthrombotic syndrome therapies, such as statins.

Rosuvastatin for the prevention of venous thromboembolism: a pooled analysis of the HOPE-3 and JUPITER randomized controlled trials

AIMS

To examine the association between rosuvastatin and VTE risk, and whether effects vary in different subpopulations stratified by key demographic, cardiovascular disease (CVD) risk factors and other risk factors associated with VTE.

METHODS AND RESULTS

An individual participant data meta-analysis was conducted across two randomized controlled trials in 30,507 participants over a mean follow up of 3.62 years, Individuals had no prior history of vascular disease but were at intermediate CV risk. In both trials, participants were randomized to receive rosuvastatin or matching placebo. The primary outcome was VTE during follow-up, defined as either deep vein thrombosis or pulmonary embolism. Associations between rosuvastatin and VTE were examined in the overall pooled cohort, and subpopulations stratified by demographic risk factors (i.e. age, sex), CVD risk factors (i.e. obesity, smoking, lipid levels, blood pressure levels, C-reactive protein level), and a history of cancer.Mean age was 65.96 (SD 7.19) years of age, and 17,832 (58.45%) were male. 5,434 (17.82%) were smokers, median BMI was 27.6 (Interquartile range [IQR] 24.7 - 31.1) kg/m2, and median CRP level was 3.4 (IQR 2.1 - 6.0) mg/L. There were 139 VTE events. In the pooled cohort, rosuvastatin was associated with a large proportional reduction in the risk of VTE (hazard ratio 0.53, 95% CI 0.37 - 0.75). No significant interactions were observed between treatment with rosuvastatin and the risk of VTE across subpopulations stratified by demographic, CVD risk factors or a history of cancer (p-values for interactions >0.05 for all subgroups).

CONCLUSIONS

Rosuvastatin is associated with a 47% proportional reduction in the risk of VTE, and its effect is consistent both in the presence or absence of VTE related clinical risk factors.

TRANSLATIONAL PERSPECTIVE

In this individual participant data meta-analysis of two large randomized controlled trials comparing rosuvastatin to placebo, rosuvastatin was associated with a 47% proportional reduction in the risk of VTE. The effect of rosuvastatin was consistent across a broad range of demographic factors, cardiovascular risk factors, and a history of cancer. This study demonstrates that rosuvastatin is broadly affective at reducing the risk of VTE both in the presence or absence of VTE associated clinical risk factors. Results inform future research on the use of statins for this indication.

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.

The role of platelets in thrombus fibrosis and vessel wall remodeling after venous thrombosis

PURPOSE

Platelets are known to play an important role in venous thrombogenesis, but their role in thrombus maturation, resolution, and postthrombotic vein wall remodeling is unclear. The purpose of this study was to determine the role that circulating platelets play in the later phases of venous thrombosis.

METHODS

We used a murine inferior vena cava (IVC) stenosis model. Baseline studies in untreated mice were performed to determine an optimal postthrombotic time point for tissue harvest that would capture both thrombus maturation/resolution and postthrombotic vein wall remodeling. This time point was found to be postoperative day 10. After undergoing IVC ultrasound on day 2 to confirm venous thrombus formation, mice were treated with a daily injection of platelet-depleting antibody (anti-GP1bα) to maintain thrombocytopenia or with control IgG until postoperative day 10, at which time IVC and thrombi were harvested and thrombus length, volume, fibrosis, neovascularization, and smooth muscle cell invasion analyzed. Vein wall fibrosis and intimal thickening were also determined.

RESULTS

Mice that were made thrombocytopenic after venous thrombogenesis had thrombi that were less fibrotic, with fewer invading smooth muscle cells. Furthermore, thrombocytopenia in the setting of venous thrombosis resulted in less postthrombotic vein wall intimal thickening. Thrombus volume did not differ between thrombocytopenic mice and their control peers.

CONCLUSIONS

This work suggests that circulating platelets contribute to venous thrombus maturation, fibrosis, and adverse vein wall remodeling, and that that inhibition of platelet recruitment may decrease thrombus and vein wall fibrosis, thus helping thrombolysis and preventing postthrombotic syndrome.

Downregulation of interleukin-6 and C-reactive protein underlies a novel inhibitory role of microRNA-136-5p in acute lower extremity deep vein thrombosis

Deep vein thrombosis (DVT) comprises a critical and common health condition with high incidence, mortality, and long-term adverse sequelae. Several differentially expressed microRNAs (miRNAs) have emerged as promising prognostic markers in DVT. The present study intended to explore the functional relevance of miR-136-5p in acute lower extremity DVT (LEDVT). Rat models of acute LEDVT were established and miR-136-5p expression was altered by agomir or antagomir to assess its effects. In addition, in vitro gain- and loss-experiments, prior to exposure to CoCl₂, were performed to investigate effects of miR-136-5p on human umbilical vein endothelial cell (HUVEC) apoptosis and levels of interleukin-6 (IL-6) and C-reactive protein (CRP). miR-136-5p was downregulated, whereas IL-6 and CRP were elevated in acute LEDVT patients. Notably, miR-136-5p was confirmed to target both IL-6 and CRP. Overexpression of miR-136-5p led to reduced length, weight, and ratio of weight to length of the venous thrombus. Furthermore, overexpressed miR-136-5p downregulated the expression of IL-6 and CRP, consequently inhibiting HUVEC apoptosis. Conjointly, our data indicate that the overexpression of miR-136-5p has the potential to bind to the 3’-UTR in the mRNAs for IL-6 and CRP and mitigate acute LEDVT, which provides a basis for new therapeutic targets in acute LEDVT treatment.

Predictive value of preoperative erythrocyte electrophoresis exponent for acute deep vein thrombosis after total knee arthroplasty in patients with knee osteoarthritis

Background

Hemorheological parameters have been confirmed to be related with deep vein thrombosis (DVT). This study is aimed to verify whether preoperative erythrocyte electrophoresis exponent was associated with postoperative deep vein thrombosis (DVT) risk after total knee arthroplasty (TKA) in patients with primary knee osteoarthritis (KOA).

Methods

From March 2010 to May 2020, a total of 750 consecutive KOA patients who accepted unilateral TKA were enrolled. They were divided into DVT (176 patients) and non-DVT groups (574 patients) according to the examination results of the Doppler ultrasound of deep veins in both lower limbs on postoperative day 3. The Chi-square test, Student’s t test, and multivariate logistic regression analysis were performed to analyze the correlation of erythrocyte electrophoresis exponent and DVT risk in 2 groups. Receiver operating characteristic (ROC) analysis was used to assess predictive value of erythrocyte electrophoresis exponent for DVT.

Results

A low erythrocyte electrophoresis exponent was a significant risk factor for DVT in patients with primary KOA (p < 0.05), especially in females when stratified by gender (p < 0.05).

Conclusions

The findings suggest that lower erythrocyte electrophoresis before surgery may be independently associated with a higher post-surgery DVT risk in primary KOA patients. It is necessary to optimize prophylaxis strategies for DVT in these patients.

Prospective Analysis of the Mechanisms Underlying Ineffective Deep Vein Thrombosis Prophylaxis in Necrotizing Pancreatitis

BACKGROUND

Patients with necrotizing pancreatitis (NP) have the highest rate of venous thromboembolism (VTE) of any hospitalized patient (57%). We hypothesized that VTE prophylaxis might be inadequate in the setting of this profound inflammatory disease and that early detection of deep vein thrombosis would limit pulmonary embolism.

STUDY DESIGN

All patients with NP treated at a single center between August 2018 and December 2019 were enrolled in prospective, weekly VTE screening, including 4-extremity duplex ultrasound. Routine chemoprophylaxis included low-molecular-weight or unfractionated heparin. Peak serum anti-factor Xa concentration was measured during weekly screening (goal prophylaxis 0.2 to 0.4 IU/mL).

RESULTS

Eighty-five patients with NP underwent a total of 201 screening events (mean 2.4 per patient). VTE developed in 55 patients (65%), including splanchnic vein thrombosis in 41 patients (48%) and extremity deep vein thrombosis (eDVT) in 32 patients (38%). Extremity DVT was diagnosed a mean ± SD of 44 ± 30 days after NP onset. Symptomatic pulmonary embolism was prevented in all patients diagnosed with eDVT and no contraindication to anticoagulation (0 of 29). Prophylactic anti-factor Xa concentration was only achieved in 21% (12 of 57 screening events); no eDVTs developed in patients achieving prophylactic anti-factor Xa concentration.

CONCLUSIONS

In patients with NP, identification of eDVT by screening ultrasound permits early treatment and prevents symptomatic pulmonary embolism. Fixed dosing of chemical prophylaxis is inadequate in most patients with NP and likely contributes to the mechanism of increased VTE in NP.

Routine Venous Thromboembolism Prophylaxis May Be Inadequate in the Hypercoagulable State of Severe Coronavirus Disease 2019

OBJECTIVES

The aim of this study was to determine the frequency of venous thromboembolism in critically ill coronavirus disease 2019 patients and associate a degree of inflammatory marker elevation to venous thromboembolism development.

DESIGN

An observational study that identified patients with severe coronavirus disease 2019 between March 12, 2020, and March 31, 2020. Data reported are those available through May 6, 2020.

SETTING

A multicenter study including three Indianapolis area academic hospitals.

PATIENTS

Two-hundred forty consecutive patients with confirmed severe acute respiratory syndrome coronavirus 2 infection were admitted to one of three hospitals. One-hundred nine critically ill coronavirus disease 2019 patients admitted to the ICU were included in the analysis.

INTERVENTIONS

All patients received routine subcutaneous chemical venous thromboembolism prophylaxis.

MEASUREMENTS AND MAIN RESULTS

The primary outcome of this study was to determine the frequency of venous thromboembolism and the degree of inflammatory and coagulation marker elevation associated with venous thromboembolism development. Descriptive statistics outlined the frequency of venous thromboembolism at any time during severe coronavirus disease 2019. Clinical course and laboratory metrics were compared between patients that developed venous thromboembolism and patients that did not develop venous thromboembolism. Hypercoagulable thromboelastography was defined as two or more hypercoagulable parameters.

MAIN RESULTS

One-hundred nine patients developed severe coronavirus disease 2019 requiring ICU care. The mean (± SD) age was 61 ± 16 years and 57% were male. Seventy-five patients (69%) were discharged home, 7 patients (6%) remain in the hospital, and 27 patients (25%) died. Venous thromboembolism was diagnosed in 31 patients (28%) 8 ± 7 days after hospital admission, including two patients diagnosed with venous thromboembolism at presentation to the hospital. Elevated admission D-dimer and peak D-dimer were associated with venous thromboembolism development (p < 0.05). D-dimer greater than 2,600 ng/mL predicted venous thromboembolism with an area under the receiver operating characteristic curve of 0.760 (95% CI, 0.661-0.858; p < 0.0001), sensitivity of 89.7%, and specificity of 59.5%. Twelve patients (11%) had thromboelastography performed and 58% of these patients had a hypercoagulable study. The calculated coagulation index was hypercoagulable in 50% of patients with thromboelastography.

CONCLUSIONS

These data show that coronavirus disease 2019 results in a hypercoagulable state. Routine chemical venous thromboembolism prophylaxis may be inadequate in preventing venous thromboembolism in severe coronavirus disease 2019.

Effect of metabolic syndrome on mean pulmonary arterial pressures in patients with acute pulmonary embolism treated with catheter-directed thrombolysis

BACKGROUND

Metabolic syndrome (MetS) has been associated with a procoagulant and hypofibrinolytic state. Current data exploring the role of MetS in venous thromboembolism (VTE) are limited. The objective was to measure the prevalence of MetS in patients with acute PE receiving catheter-directed thrombolysis (CDT) and to investigate its effect on mean pulmonary arterial pressure and overall treatment success.

METHODS

We used a 3-year prospective registry of ED patients with acute PE with severity qualifying for activation of a PE response team (PERT). All patients had CDT with catheter-measured mPAP and angiography. The presence or absence of MetS components were extracted from chart review based on the following criteria: 1. body mass index (BMI) >30 kg/m²; 2. diagnosed hypertension; 3. diabetes mellitus (including HbA1c >6.5%) and; 4. dyslipidemia (including triglycerides >150 mg/dL or high-density lipoprotein <40 mg/dL).

RESULTS

Of the 134 patients, 85% met the criteria for at least one of four MetS components, with obesity being most common, present in 71%. Results demonstrated a positive concordance between the number of criteria for MetS and MPAP, both pre- and post-fibrinolysis, as pressures tended to increase with each additional MetS criterion. Multivariate regression analysis determined age (-), BMI (+) and hypertension (+) to be significant independent predictor variables for mPAP.

CONCLUSIONS

MetS was common in patients with more severe manifestations of PE and was associated with higher mPAP values both at diagnosis and following treatment with CDT.

Cholesterol Disturbances and the Role of Proper Nutrition in CKD Patients

Chronic kidney disease (CKD) is a widespread disease with increasing prevalence in the modern society. Lipid disturbances are common in this group of patients. In most patients with CKD atherogenic dyslipidemia is observed. Dyslipidemia in patients with renal diseases increases the risk of cardiovascular diseases and it accelerates the progression of chronic kidney disease to its end stage. The amelioration of dyslipidemia and the lowering of oxidative stress, inflammatory processes, insulin sensitivity and remnant lipoproteins levels may lead to the reduction in cardiovascular burden. Nutritional interventions can strengthen the beneficial effect of treatment and they play an important role in the preservation of overall well-being of the patients with CKD since the aim of appropriate diet is to reduce the risk of cardiovascular events, prevent malnutrition, and hamper the progression of kidney disease. The management of dyslipidemia, regardless of the presence of chronic kidney disease, should be initiated by the introduction of therapeutic lifestyle changes. The introduction of diet change was shown to exert beneficial effect on the lipid level lowering that reaches beyond pharmacological therapy. Currently available evidence give the impression that data on dietary interventions in CKD patients is not sufficient to make any clinical practice guidelines and is of low quality.

Associations of Serum Lipids and Deep Venous Thrombosis Risk After Total Knee Arthroplasty in Patients With Primary Knee Osteoarthritis

Deep venous thrombosis (DVT) of the lower extremities is a common complication after total knee arthroplasty (TKA). This study aimed to investigate the potential associations between serum lipids and the risk of DVT after TKA in patients with primary knee osteoarthritis (OA). A total of 431 patients who received TKA caused by primary knee OA were randomly enrolled. According to the results of the color Doppler ultrasound of bilateral lower extremities deep veins on the third day postoperatively, patients were divided into DVT and non-DVT groups. Comparisons of preoperative serum levels of triglycerides, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol (LDL-C), apolipoprotein A1, and apolipoprotein B were then performed by the Student’s t test, χ2 test, and multivariate logistic regression analysis. For females, DVT patients had a higher serum LDL-C level at baseline ( P = .043) compared with non-DVT patients. A higher LDL-C value was significantly associated with an elevated DVT risk following TKA in female patients ( P = .037). In female patients with primary knee OA, preoperative serum LDL-C level may have an association with DVT risk after TKA. The relatively small male sample size may limit the accuracy of the findings.

Development of Dual Drug Eluting Cardiovascular Stent with Ultrathin Flexible Poly(l-lactide-co-caprolactone) Coating

The pleiotropic effects of the atorvastatin-fenofibrate combination can be effectively harnessed for site-specific therapy to minimize stent-related complications. The present study aims to utilize the pleiotropic effects of these two drugs entrapped in a uniform and defect-free coating of poly(l-lactide-co-caprolactone) (PLCL) on a stainless steel stent to overcome stent-associated limitations. The stent coating parameters were optimized using ultrasonic spray coating technique to achieve a thin, smooth, and defect-free dual drug-loaded polymer coating on the stent. The dual drug-loaded polymer coated stent was characterized for surface morphology, thickness and coating integrity. In vitro drug release kinetics of the fabricated stent reveals a sustained release of both drugs for more than 60 days. Significant reduction of thrombus formation and adhesion of lipopolysaccharide-stimulated macrophages on the dual drug containing polymer-coated stent indicates that the drug combination possesses antithrombotic and anti-inflammatory effects. The combination did not adversely influence endothelialization but significantly retarded smooth muscle cell proliferation indicating its potential to overcome restenosis. No bacterial biofilm formation was observed on the stent due to the antibacterial activity of atorvastatin. A rat subcutaneous model was used to evaluate the biocompatibility of the coated stent and compared with the commercial stent. MicroCT, scanning electron microscopy, and morphometric analyses revealed that the coated stents exhibited excellent histocompatibility with no inflammatory response as evidenced from the cytokine levels measured 28 days postimplantation. Our data demonstrates for the first time that the combination of atorvastatin and fenofibrate can be successfully employed in cardiovascular stents to overcome the current limitations of conventional drug-eluting stents.

Effect of Simvastatin on Thrombopoiesis in Porcine Bone Marrow

INTRODUCTION

Statins are pharmacological agents commonly used to lower serum cholesterol level. The aim of the experiment was to investigate the effect of the statin simvastatin on thrombopoiesis in the porcine model because it is the closest to the human one regarding physiological and genetic similarities.

MATERIAL AND METHODS

The study was conducted on a group of 32 pigs randomly divided into two equal groups: control and experimental. The pigs were treated for 28 and 56 days with simvastatin in a dose of 40 mg per day per animal. Cytological evaluation of bone marrow smears was performed to assess the average number of all types of cells during thrombopoiesis as was analysis of haematological parameters to assess PLT and MPV.

RESULTS

During the course of the experiment statistically significant changes in the number of promegakaryocytes were observed. Other parameters also showed some fluctuations during the study. However, these changes were not statistically significant.

CONCLUSION

The obtained results clearly indicate a toxic influence of simvastatin on the process of thrombopoiesis and prove that statins reduce mean platelet volume, thus affecting the process of clot formation through the period of administration in a duration-dependent manner.

Association of statins, aspirin, and venous thromboembolism in women with endometrial cancer

OBJECTIVE

The anti-thrombogenic effects of statins and aspirin have been reported in various malignancies but have not been well examined in endometrial cancer. This study examined the association between statin and/or aspirin use and venous thromboembolism (VTE) risk in endometrial cancer.

METHODS

This is a multi-center retrospective study examining 2527 women with endometrial cancer between 2000 and 2015. Statin and aspirin use at diagnosis was correlated to VTE risk during follow-up on multivariable analysis.

RESULTS

There were 132 VTE events with a 5-year cumulative incidence rate of 6.1%. There were 392 (15.5%) statin users and 219 (8.7%) aspirin users, respectively. On multivariable analysis, statin use was associated with an approximately 60% decreased risk of VTE when compared to non-users (5-year cumulative rates 2.5% versus 6.7%, adjusted-hazard ratio [HR] 0.42, 95% confidence interval [CI] 0.19-0.92, P = 0.030) whereas aspirin did not demonstrate statistical significance (2.0% versus 6.5%, adjusted-HR 0.54, 95%CI 0.19-1.51, P = 0.24). There was a trend of joint effect between statin and aspirin although it did not demonstrate statistical significance: VTE risks for dual statin/aspirin user (adjusted-HR 0.27, 95%CI 0.04-2.07), statin alone (adjusted-HR 0.40, 95%CI 0.18-0.93), and aspirin alone (adjusted-HR 0.51, 95%CI 0.16-1.64) compared to non-use after adjusting for patient characteristics, tumor factors, treatment types, and survival events (P-interaction = 0.090). When stratified by statin type, simvastatin demonstrated the largest reduction of VTE risk (5-year cumulative rates 1.1% versus 6.7%, adjusted-HR 0.17, 95%CI 0.02-1.30, P = 0.088). Obesity, absence of diabetes mellitus, type II histology, and recurrent disease were the factors associated with decreased VTE risk with statin use (all, P-interaction<0.05).

CONCLUSION

Our study suggests that statin use may be associated with decreased risk of VTE in women with endometrial cancer.

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.

Prevention of post-operative complications by using a HMG-CoA reductase inhibitor in patients undergoing one-lung ventilation for non-cardiac surgery: study protocol for a randomised controlled trial

Background

Postoperative pulmonary complications (PPC) and peri-operative myocardial infarction (MI) have a significant impact on the long-term mortality of surgical patients. Patients undergoing one-lung ventilation (OLV) for surgery are at a high risk of developing these complications. These complications could be associated with intensive care unit (ICU) admissions and longer hospital stay with associated resource and economic burden. Simvastatin, a HMG-CoA reductase enzyme inhibitor has been shown to have pleiotropic anti-inflammatory effects as well as being endothelial protective. The benefits of statins have been shown in various observational studies and in small proof-of-concept studies. There is an urgent need for a well-designed, large clinical trial powered to detect clinical outcomes. The Prevention HARP 2 trial will test the hypothesis ‘simvastatin 80 mg when compared to placebo will reduce cardiac and pulmonary complications in patients undergoing elective oesophagectomy, lobectomy or pneumonectomy’.

Methods/design

The Prevention HARP 2 trial is a UK multi-centre, randomised, double-blind, placebo-controlled trial. Adult patients undergoing elective oesophagectomy, lobectomy or pneumonectomy will be eligible. Patients who are already on statins will be excluded from this trial. Patients will be randomised to receive simvastatin 80 mg or matched placebo for 4 days pre surgery and for up to 7 days post surgery. The primary outcome is a composite outcome of PPC and MI within 7 days post surgery. Various secondary outcome measures including clinical outcomes, safety outcomes and health economic outcomes will be collected. The study aims to recruit 452 patients in total across 12 UK sites.

Discussion

The results of the Prevention HARP 2 trial should add to our understanding of the benefits of peri-operative statins and influence clinical decision-making. Analysis of blood and urine samples from the patients will provide insight into the mechanism of simvastatin action.

Trial registration

International Standard Randomised Controlled Trials registry, ID: ISRCTN48095567. Registered on 11 November 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-3078-5) contains supplementary material, which is available to authorized users.

Comparison of acute and convalescent biomarkers of inflammation in patients with acute pulmonary embolism treated with systemic fibrinolysis vs. placebo

: Previous studies have associated biomarkers indicative of acute inflammation with pulmonary embolism, which may amplify coagulation, inhibit fibrinolysis and increase risk of venous thromboembolism (VTE) recurrence. The aim of this study was to measure inflammatory and hemostatic biomarkers in acute submassive pulmonary embolism at diagnosis and 3-month follow-up and to test the impact of treatment with fibrinolysis. Secondary analysis of a multicenter, double-blinded, randomized controlled trial including patients with submassive pulmonary embolism. Blood samples were obtained within 24 h of diagnosis and prior to bolus-dose tenecteplase (TNK) or placebo; all patients received standard anticoagulation and blood was redrawn 3 months later. Plasma concentrations of inflammatory [Interleukin 6 (IL-6), C-reactive protein (CRP), myeloperoxidase (MPO)] and hemostatic [plasminogen activator inhibitor-1 (PAI-1), fibrinogen, thrombin-activatable fibrinolysis inhibitor and D-dimer] biomarkers were quantified. The median values of the biomarkers of inflammation (IL-6, CRP, MPO) were all significantly decreased at 3-month follow-up, ranging from a 60 to 91% reduction over this time period. Concentrations of PAI-1 and fibrinogen did not change significantly. D-dimer concentration at 3-month follow-up was lower in patients treated with fibrinolysis vs. placebo and appeared to have a trend toward significance (placebo 310 vs. TNK 220 ng/ml, P = 0.051). Acute pulmonary embolism causes marked but transient inflammation, as demonstrated by the significant elevation in the inflammatory biomarkers at diagnosis, followed by their reduction in more than 80% of patients at 3-month follow-up.

Cytokines, Adhesion Molecules, and Matrix Metalloproteases as Predisposing, Diagnostic, and Prognostic Factors in Venous Thrombosis

The inflammatory response is a well-established part of, and a prerequisite for, venous thrombosis. To better understand the pathophysiology of venous thrombosis and to identify improved diagnostic biomarkers, further studies of the relationship between inflammation and coagulation are needed. We review previous studies concerning inflammatory biomarkers in venous thromboembolism, in particular cytokines, soluble adhesion molecules and matrix metalloproteases as predisposing, diagnostic and prognostic factors in venous thrombosis. Elevated cytokines and genetic alterations coding for cytokines are found in several patient cohorts which indicate that cytokines are involved as predisposing factors in venous thrombosis development. Increased levels of pro-inflammatory cytokines are detected both in animal models and in patients with acute venous thrombosis and clinical trials, although currently without evident diagnostic value. Adhesion molecules are crucial in the development of venous thrombosis, especially P-selectin seems important in initiating leukocyte accumulation and adhesion to endothelium for subsequent platelet accumulation. Several studies have demonstrated increased soluble P-selectin levels in patients with venous thrombosis, emphasizing its potential role as diagnostic marker and also as a therapeutic target. Matrix metalloproteases are essential effectors during venous thrombosis resolution and may impact vessel wall fibrosis, and together with their natural occurring inhibitors are crucial in acute and chronic thrombosis pathophysiology. Furthermore, studies in animal models of venous thrombosis have demonstrated anti-inflammatory treatment to be effective in terms of thrombus resolution and reduction of vessel wall damage, without increase in bleeding risk during the course of treatment. Thus, soluble mediators should be further investigated both as possible biomarkers and therapeutic targets in venous thromboembolic disease.

Prevention and treatment of the post-thrombotic syndrome

Post thrombotic syndrome (PTS) is a common chronic complication of deep vein thrombosis of the leg (DVT). Treatment options are limited therefore emphasis is placed on its prevention. Several risk factors have been recognized, but were so far not used for risk stratification or translation into prediction models. Early interventions did not yet result in more successful preventive treatment strategies; for the acute phase of DVT there is equipoise on the value of elastic compression, as well as on catheter directed thrombolysis. There are no drugs specifically targeted at PTS prevention. The use of anticoagulant medication such as direct oral anticoagulants (DOACs) might decrease PTS incidence, but this needs to be corroborated. Both research into more effective treatment options as well as future PTS management may benefit from a uniform diagnostic strategy and the use of prediction rules to better allocate treatment and thereby increase treatment efficacy.

Preinjury statin use and thromboembolic events in trauma: a 10-year retrospective evaluation

BACKGROUND

Traumatic injury is well known to increase the risk of venous thromboembolic events (VTEs), occurring in up to 58% of trauma patients. Statin medications have significant anti-inflammatory properties and have been shown to reduce the risk of VTE. We hypothesized that trauma patients who received statin medication before injury would have a lower incidence of VTE after injury.

METHODS

A 10-y retrospective review identified all patients admitted to our trauma service with an injury severity score >9 and an intensive care unit stay of >3 d. This population was categorized as either "statin recipient" (SR) or "statin naïve," with subsequent categorical division by occurrence of VTE. Our primary outcome measure was the occurrence of documented VTE in both statin naïve and SR subjects.

RESULTS

A total of 2519 trauma patients were included with 97 (3.8%) developing VTE. Pretrauma statin use in males remained as an independent predictor of VTE (odds ratio = 2.25, 95% confidence interval = 1.25-4.04, P < 0.01). The median time to VTE onset was 3 d longer in SRs (10.0 d; confidence interval = 7.3-12.7, P < 0.05).

CONCLUSIONS

Pretrauma statin use does not appear to have a protective benefit of VTE prevention in trauma patients, as we have shown pretrauma SR male trauma patients to have a twofold increased incidence of VTE. However, when considering the 3 d longer median time to VTE onset found in SRs, we consider the protective benefit of statin use reported in the current literature as likely attributable to this observed delayed onset.