Statin treatment and risk of recurrent venous thromboembolism: a nationwide cohort study

Statins during Anticoagulation for Emergency Life-Threatening Venous Thromboembolism: A Review

Venous thromboembolism (VTE) is the leading cause of morbidity and death worldwide, after cancer and cardiovascular diseases. VTE is defined to include pulmonary embolism (PE) and/or deep vein thrombosis (DVT). Approximately 25% of PE patients experience sudden death as an initial symptom of VTE, and between 10% and 30% of patients die within the first month after diagnosis. Currently, the only drugs approved for the treatment of both acute and chronic VTE are vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs). However, their effectiveness is limited due to their associated risk of bleeding. Ideally, therapy should be able to treat VTE and limit the risk of VTE recurrence without increasing the risk of bleeding. Several studies have shown that the use of statins during anticoagulation for VTE reduces the risk of death and VTE recurrence. However, to date, there are conflicting data on the impact of statins during anticoagulation for VTE. A biological protective function of statins during anticoagulation has also been reported. Statins affect D-dimer levels; tissue factor (TF) gene expression; and VIII, VII, and Von Willebrand clotting factors-the major clotting factors they are able to affect. However, the usefulness of statins for the treatment and prevention of VTE is currently under debate, and they should not be substituted for guideline-recommended VTE prophylaxis or anticoagulation treatment. In this review of the literature, we illustrate the advances on this topic, including data on the role of statins in primary VTE prevention and secondary VTE prevention, related biological mechanisms, the risk of bleeding during their use, and their ability to reduce the risk of death.

Statins Effects on Blood Clotting: A Review

Statins are powerful lipid-lowering drugs that inhibit cholesterol biosynthesis via downregulation of hydroxymethylglutaryl coenzyme-A reductase, which are largely used in patients with or at risk of cardiovascular disease. Available data on thromboembolic disease include primary and secondary prevention as well as bleeding and mortality rates in statin users during anticoagulation for VTE. Experimental studies indicate that statins alter blood clotting at various levels. Statins produce anticoagulant effects via downregulation of tissue factor expression and enhanced endothelial thrombomodulin expression resulting in reduced thrombin generation. Statins impair fibrinogen cleavage and reduce thrombin generation. A reduction of factor V and factor XIII activation has been observed in patients treated with statins. It is postulated that the mechanisms involved are downregulation of factor V and activated factor V, modulation of the protein C pathway and alteration of the tissue factor pathway inhibitor. Clinical and experimental studies have shown that statins exert antiplatelet effects through early and delayed inhibition of platelet activation, adhesion and aggregation. It has been postulated that statin-induced anticoagulant effects can explain, at least partially, a reduction in primary and secondary VTE and death. Evidence supporting the use of statins for prevention of arterial thrombosis-related cardiovascular events is robust, but their role in VTE remains to be further elucidated. In this review, we present biological evidence and experimental data supporting the ability of statins to directly interfere with the clotting system.

Statin use and 30-day mortality in patients with acute symptomatic pulmonary embolism

BACKGROUND

Statins possess antithrombotic and profibrinolytic properties. The association between statin use and short-term outcomes in patients with acute pulmonary embolism (PE) remains unknown.

METHODS

We used the data from the Registro Informatizado de Pacientes con Enfermedad TromboEmbólica registry to compare the 30-day all-cause mortality in patients with acute PE according to the use of statins. Secondary outcome was fatal PE. We used cancer-related mortality as a falsification endpoint.

RESULTS

From January 2009 to April 2021, 31 169 patients with PE were recruited. Of these, 5520 (18%) were using statins at baseline: low intensity: 829, moderate: 3636, high intensity: 1055. Statin users were older and had a higher frequency of diabetes, hypertension, or atherosclerotic disease than non-users (P <0.001 for all comparisons). During the first 30 days, 1475 patients died (fatal PE, 255). On multivariable analysis, statin users had a lower risk of all-cause death (odds ratio [OR]: 0.65; 95% confidence interval [CI]: 0.56-0.76) and fatal PE (OR: 0.42; 95% CI: 0.28-0.62) than non-users. The risk for death was lower in patients using either low- (OR: 0.51; 95% CI: 0.34-0.77), moderate- (OR: 0.68; 95% CI: 0.57-0.81), or high-intensity statins (OR: 0.68; 95% CI: 0.51-0.92). Results did not change in mixed effects logistic regression models with hospitals as a random effect. Statins were not associated with a significant chance in cancer mortality (falsification endpoint).

CONCLUSIONS

PE patients using statins at baseline had a significantly lower risk of dying within the first 30 days than non-users. Randomized trials are needed to confirm these data.

Association between cardiovascular risk factors and venous thromboembolism in the elderly

BACKGROUND

The preponderance of the evidence supports no association between traditional cardiovascular risk factors and venous thromboembolism (VTE), other than obesity. There are limited data in older people.

OBJECTIVES

To investigate whether cardiovascular risk factors (body mass index, smoking, alcohol intake, hypertension, and diabetes) are associated with the risk of VTE in elderly and to assess the combined effect between cardiovascular risk factors and genetic risk factors for VTE (factor V Leiden/prothrombin 20210A, positive family history of VTE, and non-O blood group).

METHODS

The Age and Thrombosis, Acquired and Genetic risk factors in the Elderly study is a multicenter case-control study performed in Vermont, USA and Leiden, the Netherlands, comprising 401 cases with first VTE and 431 control subjects, all aged ≥70 years. To assess the risk of VTE, odds ratios (OR) with 95% confidence intervals (CIs) were calculated, adjusting for potential confounders.

RESULTS

Both height and weight were positively associated with VTE risk: the ORs were 2.2 (95% CI, 1.2-3.9) and 1.5 (95% CI, 1.0-2.4) in the top quartile for height and weight separately. This risk was more pronounced for unprovoked VTE. Smoking, alcohol intake, and diabetes were not associated with VTE. Higher systolic and diastolic blood pressure and hypertension were associated with a decreased risk of VTE. In the presence of a genetic predisposition, height and weight further increased the risk of VTE.

CONCLUSIONS

In the elderly, height and weight are positively associated with the risk of VTE. With genetic predisposition, higher levels of height and weight further increase the risk of VTE.

Association of statin use and the risk of recurrent pulmonary embolism in real-world Chinese population

Background

Previous studies have suggested that statins exert protective effects against venous thromboembolism. However, few randomized studies have explicitly concentrated on patients with pulmonary embolism. Thus far, evidence of the effect of statins on the pulmonary embolism recurrence in China remains lacking.

Methods

A retrospective analysis was conducted utilizing our University database. Patients with an International Coding of Diseases-defined diagnosis of pulmonary embolism from 1 January 2017 to 31 December 2019 were included. The patients were divided into two groups, namely, with statin or without statin treatment. Propensity score matching was applied to balance the covariates between the comparison groups. Univariate analysis and multivariable logistic regression were performed to analyze the association between statin use and pulmonary embolism recurrence.

Results

A total of 365 patients diagnosed with pulmonary embolism were included in the research. Pulmonary embolism recurrence accounted for 15.1% of the patients and was observed during the entire study period. In the initial population, no significant difference in recurrence was observed between the groups with and without statins treatment (statin 15.6% vs. non-statin 14.9%, p = 0.860). After propensity score matching, multivariate logistic regression analysis revealed that the odds ratio of pulmonary embolism recurrence in the statin users was 0.489 (95% confidence interval 0.190–1.258, p = 0.138).

Conclusions

Our study provides no support for the use of statins as an adjunctive therapy in patients with pulmonary embolism at the initiated time of diagnosis or as a prophylactical plan when anticoagulation is discontinued attempting to reduce the risk of recurrence.

Effect of statins on the risk of recurrent venous thromboembolism: A systematic review and meta-analysis

BACKGROUND

Recent studies have suggested that statins may be associated with a lower risk of recurrent venous thromboembolism (VTE).

METHODS

We systematically searched PubMed, Web of Science and Cochrane Library from inception until May 2020 to identify any eligible studies that reported the association between statin use and the risk of recurrent VTE, and conducted a comprehensive systematic review and meta-analysis (PROSPERO registration number: CRD42020190169) on this matter.

RESULTS

A total of 14 observational studies were included for qualitative review and 12 of them qualified for meta-analyses. The main meta-analysis found that statin use was associated with a lower risk of disease recurrence among patients with VTE (pooled adjusted HR: 0.76, 95% CI: 0.69-0.83), which was robust in sensitivity analyses and free of significant publication bias. Additionally, such association was present when restricting to periods after anticoagulation withdrawal (pooled adjusted HR: 0.78, 95% CI: 0.70-0.88) and when separately analyzing recurrent deep vein thrombosis (pooled adjusted HR: 0.71, 95% CI: 0.62-0.81) and recurrent pulmonary embolism (pooled adjusted HR: 0.80, 95% CI: 0.66-0.97; P = 0.027). Furthermore, statin use in patients with VTE was also found to be associated with a lower risk of all-cause mortality (adjusted HR: 0.65, 95% CI: 0.56-0.77), and possibly an even lower risk of bleeding (adjusted HR: 0.88, 95% CI: 0.73-1.07), albeit not statistically significant.

CONCLUSION

Statins have the potential to reduce recurrent events among patient with VTE. Randomized clinical trials to better explore the effect of statins in secondary prevention of VTE are warranted.

Statin Use is Associated with Reduced Risk of Recurrence in Patients with Venous Thromboembolism

BACKGROUND

Statin therapy appears to reduce incidence of venous thromboembolism in secondary analyses of non-venous thromboembolism trials, but no evidence has shown effect of statins in large population samples. The objective of this study was to examine the magnitude of the effect of statin therapy on venous thromboembolism recurrence across a large statewide population.

METHODS

This was a retrospective analysis of the Indiana Network for Patient Care database. All patients with an International Classification of Diseases-defined diagnosis of either deep vein thrombosis or pulmonary embolism from 2004-2017 were included. We collected Generic Product Identifier codes to determine whether patients had been prescribed a statin medication and divided patients into 2 groups: + or - statin. We then performed a propensity-matching analysis to balance covariates and created a final logistic regression model with statin use as the predictor variable and venous thromboembolism recurrence as the dependent variable.

RESULTS

This study included a total of 192,908 patients with documented statin use in 13.5%. Venous thromboembolism recurrence occurred in 16% of all patients over the study period. After propensity matching, patients not on a statin were found to have significantly higher rates of venous thromboembolism recurrence (20% vs 16%, P < .0001). Logistic regression yielded an odds ratio of 0.75 (95% confidence interval, 0.72-0.79) for venous thromboembolism recurrence for those on statin therapy.

CONCLUSIONS

We found that a statin prescription reduced risk of venous thromboembolism recurrence by approximately 25% after adjusting for risk factors, supporting the adjunctive role of statins in the prevention of venous thromboembolism recurrence.

Dissolution of metastatic thymic carcinoma-associated right atrial thrombus with rivaroxaban

Thymic carcinoma typically exhibits more clinically aggressive behavior and portends a worse prognosis as compared to thymoma. Venous thromboembolism is a significant cause of morbidity and mortality in oncologic patients. Traditionally, the standard-of-care management of cancer-associated venous thromboembolism has been therapeutic anticoagulation with low molecular weight heparins; however, with the advent of direct oral anticoagulants, there is an ongoing paradigm shift to transition to these novel agents in an attempt to attenuate cancer-associated venous thromboembolism events. We describe an exceedingly rare case of metastatic thymic carcinoma-associated right atrial thrombus with high-risk embolic features, which subsequently underwent near-complete dissolution with rivaroxaban after 3 months.

Arterial and venous thrombosis: What's the link? A narrative review

Arterial thrombosis and venous thromboembolism (VTE) are traditionally considered two different entities. However, patients with unprovoked VTE are at higher risk of developing subclinical and overt atherosclerosis compared to healthy controls challenging these distinctions. Obesity may explain the association between arterial and venous disease: overweight/obese patients are prone to stasis in lower limbs veins, chronic inflammation, dyslipidemia, hypertension, and diabetes mellitus; all of which result in a hypercoagulability, VTE, and atherosclerosis. Novel therapeutic approaches combining and re-purposing traditional arterial therapies (antiplatelets and statins) and venous thrombosis therapies (anticoagulants) are emerging for the management of patients with vascular disease.

Statin and all-cause mortality in patients receiving anticoagulant therapy for venous thromboembolism. Data from the RIETE registry

BACKGROUND

The clinical outcomes during the course of anticoagulation in patients with venous thromboembolism (VTE) using statins remain controversial.

METHODS

We used the RIETE (Registro Informatizado Enfermedad TromboEmbólica) registry to compare the risk for VTE recurrences, major bleeding or death during anticoagulation, according to the use of statins at baseline. We used propensity score-matching (PSM) to adjust for confounding variables.

RESULTS

From February 2009 to January 2018, 32,062 VTE patients were included. Of these, 7,085 (22%) were using statins. Statin users were 10 years older (73±11 vs. 63±19 years, respectively) and more likely to have comorbidities or to be using antiplatelets or corticosteroids at baseline than non-users. During the course of anticoagulation (median, 177 days), 694 patients developed VTE recurrences, 848 bled and 3,169 died (fatal pulmonary embolism 176, fatal bleeding 121). Statin users had a similar rate of VTE recurrences (hazard ratio [HR]: 0.98; 95%CI: 0.82-1.17), a higher rate of major bleeding (HR: 1.29; 95%CI: 1.11-1.50) and a similar mortality rate (HR: 1.01; 95%CI: 0.93-1.10) than non-users. On PSM analysis, statin users had a significantly lower risk for death (HR: 0.62; 95%CI: 0.48-0.79) and a similar risk for VTE recurrences (HR: 0.98; 95%CI: 0.61-1.57) or major bleeding (HR: 0.85; 95%CI: 0.59-1.21) than non-users.

CONCLUSIONS

During anticoagulation for VTE, patients using statins at baseline had a lower risk to die than non-users.

D-Dimer Predicts Long-Term Cause-Specific Mortality, Cardiovascular Events, and Cancer in Patients With Stable Coronary Heart Disease: LIPID Study

BACKGROUND

D-dimer, a degradation product of cross-linked fibrin, is a marker for hypercoagulability and thrombotic events. Moderately elevated levels of D-dimer are associated with the risk of venous and arterial events in patients with vascular disease. We assessed the role of D-dimer levels in predicting long-term vascular outcomes, cause-specific mortality, and new cancers in the LIPID trial (Long-Term Intervention with Pravastatin in Ischaemic Disease) in the context of other risk factors.

METHODS

LIPID randomized patients to placebo or pravastatin 40 mg/d 5 to 38 months after myocardial infarction or unstable angina. D-dimer levels were measured at baseline and at 1 year. Median follow-up was 6.0 years during the trial and 16 years in total.

RESULTS

Baseline D-dimer levels for 7863 patients were grouped by quartile (≤112, 112-173, 173-273, >273 ng/mL). Higher levels were associated with older age, female sex, history of hypertension, poor renal function, and elevated levels of B-natriuretic peptide, high-sensitivity C-reactive protein, and sensitive troponin I (each P<0.001). During the first 6 years, after adjustment for up to 30 additional risk factors, higher D-dimer was associated with a significantly increased risk of a major coronary event (quartile 4 versus 1: hazard ratio [HR], 1.45; 95% confidence interval, 1.21-1.74), major cardiovascular disease (CVD) event (HR, 1.45; 95% confidence interval, 1.23-1.71) and venous thromboembolism (HR, 4.03; 95% confidence interval, 2.31-7.03; each P<0.001). During the 16 years overall, higher D-dimer was an independent predictor of all-cause mortality (HR, 1.59), CVD mortality (HR, 1.61), cancer mortality (HR, 1.54), and non-CVD noncancer mortality (HR, 1.57; each P<0.001), remaining significant for deaths resulting from each cause occurring beyond 10 years of follow-up (each P≤0.01). Higher D-dimer also independently predicted an increase in cancer incidence (HR, 1.16; P=0.02).The D-dimer level increased the net reclassification index for all-cause mortality by 4.0 and venous thromboembolism by 13.6.

CONCLUSIONS

D-dimer levels predict long-term risk of arterial and venous events, CVD mortality, and non-CVD noncancer mortality independent of other risk factors. D-dimer is also a significant predictor of cancer incidence and mortality. These results support an association of D-dimer with fatal events across multiple diseases and demonstrate that this link extends beyond 10 years' follow-up.

Identification of Chinese Hospitalized Patients' Risk Profile for Venous Thromboembolism (DissolVE1): A Study Protocol of a Non-Interventional Registry Study

INTRODUCTION

Venous thromboembolism (VTE) is a frequent cause of hospitalization, mortality, and long-term adverse consequence among medical and surgical inpatients. The current study is performed to identify the prophylaxis of patients with VTE risk within the 6 weeks prior to the diagnosis of VTE, and the treatment pattern during 3 months after VTE diagnosis in Chinese patients hospitalized for surgeries or medical illness.

METHODS

This multicenter, non-interventional, observational registry plans to enroll 1200 patients from 40 centers in China. The study will retrospectively collect data from patients' hospitalization record within 6 weeks of VTE diagnosis and prospectively follow-up patients for 3 months (in four visits). The primary outcome is to determine the percentage of patients receiving adequate prophylaxis in patients hospitalized within 6 weeks before VTE diagnosis and treatment pattern within 3 months after VTE diagnosis. Important secondary endpoints include determining patients with risk of VTE in the hospital setting, risk factors for VTE, and cost analysis of VTE treatment.

EXPECTED OUTCOMES

The findings will determine the characteristics of VTE, its treatment practices, cost of treatment, and quality of life in patients; this information may help in building diagnostic and prophylaxis strategies for VTE in China.

TRIAL REGISTRATION

The study is registered in the Venous Thromboembolism Registry in China with study number DIREGL07581.

FUNDING

Sanofi China.

The secondary prevention of venous thromboembolism: Towards an individual therapeutic strategy

After the anticoagulant withdrawal, a substantial proportion of patients with venous thromboembolism will develop recurrent events. Whether to consider an extended treatment depends on the risk of recurrence and bleeding risk. The assessment of the individual risk profile remains a difficult task. Several basal and post-basal factors modulate the risk of recurrence and may help clinicians to select patients who can benefit from the extended therapy. During the year 2017, new evidence regarding the post-basal factors was provided by the Morgagni and Scope studies. Another interesting novelty was the VTE-BLEED score, the first bleeding risk score that obtained the external validation in venous thromboembolism setting. In secondary prevention, the use of direct oral anticoagulants is growing instead of vitamin K antagonist. Even at lower doses, direct oral anticoagulants showed to be effective and safe, to reduce all-cause mortality and seemed to be superior to placebo for the composite outcome of fatal bleeding and fatal recurrence. After the recently published Einstein-Choice trial, the role of aspirin has become truly marginal as rivaroxaban 10 mg showed a bleeding risk similar to aspirin 100 mg but a greater effectiveness reducing the relative risk of recurrence by about 70%. Another option for secondary prevention could be sulodexide, with a lower protective effect than direct oral anticoagulants but an interesting safety profile. In conclusion, in our opinion, an individual strategy taking into account the risk of recurrence, bleeding risk, therapeutic options and patient preferences is the most appropriate approach to secondary prevention of venous thromboembolism.

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.

Statin use and risk of recurrent venous thrombosis: results from the MEGA follow-up study

INTRODUCTION

Whether statin use after first venous thrombosis reduces the risk of recurrence is uncertain. Therefore, we aimed to examine the risk of recurrent venous thrombosis in statin users vs non-users.

METHODS

Patients with a first venous thrombosis were recruited from the MEGA follow-up study. Information on statin use was obtained by linkage to the Dutch Foundation for Pharmaceutical Statistics register. Linkage was successful in 54% of all patients (n = 2,547). Cox-regression models with statin-exposure as a time-dependent co-variate were used to estimate hazard ratios (HR) with 95% confidence intervals (CI 95) for recurrence.

RESULTS

Statin therapy was continued in 153 (6.0%) patients and initiated in 233 (9.1%) patients during a median follow-up of 5.7 years. There were 367 recurrent venous thrombotic events, of which 32 occurred among statin users. Incident statin use was associated with 22% reduced risk of recurrence after multivariable adjustments (HR 0.78, CI 95: 0.46-1.31), and 13% reduced risk after propensity score adjustment (HR 0.87, CI 95: 0.52-1.47). Statin use seemed not to have an effect on recurrence in patients with an unprovoked first event (multivariable HR 1.03, CI 95: 0.54-1.98), but the statistical power was low due to few events and the results must be interpreted with caution. In general, the risk estimates were slightly attenuated when prevalent users were included in the analyses.

CONCLUSION

Our findings suggest that statins may have a modest decreasing effect on the risk of recurrent venous thrombosis. While we took care to minimize bias and confounding, the causality of the association is still unsettled.

Statins and secondary prevention of venous thromboembolism: pooled analysis of published observational cohort studies

AIMS

There have been suggestions that statins may have a potential role in secondary prevention of venous thromboembolism (VTE) [which includes deep vein thrombosis (DVT) and pulmonary embolism (PE)], but the evidence is inconsistent. We aimed to evaluate the association between statin use and risk of recurrent VTE.

METHODS AND RESULTS

We conducted a systematic review and meta-analysis of observational cohort studies. All relevant studies which reported associations between statin use and recurrent VTE outcomes were identified from MEDLINE, EMBASE, Web of Science, and manual search of bibliographies from inception to January 2017. Study specific relative risks (RRs) with 95% confidence intervals were aggregated using random effects models. Eight eligible studies comprising of 103 576 participants and 13 168 recurrent VTE outcomes were included in the pooled analysis. In pooled analysis of 7 studies, the RR for recurrent VTE was 0.73 (0.68-0.79) when comparing statin use with no use. There was no evidence of heterogeneity between contributing studies (I2=0%, 0-71%; P = 0.93). The RRs for recurrent PE (three studies) and DVT (two studies) comparing statin use with no statin use were 0.75 (95% CI: 0.58-0.96) and 0.66 (95% CI: 0.60-0.71) respectively.

CONCLUSION

Available evidence from observational cohort studies suggests a beneficial effect of statin use on VTE recurrence. Well-designed intervention studies are needed to corroborate these findings.

Long-Term Effects of Unprovoked Venous Thromboembolism on Mortality and Major Cardiovascular Events

Background

Patients with unprovoked venous thromboembolism (VTE) are at an increased risk of mortality, but whether their cardiovascular risks also increase remains to be determined. We aimed to investigate the factors associated with overall mortality and major adverse cardiovascular events in patients with unprovoked VTE.

Methods and Results

We identified 2154 patients newly diagnosed with unprovoked VTE from Taiwan's National Health Insurance Database between 2000 and 2013, excluding those with reversible etiologies, underlying cancer, or autoimmune diseases. These patients with VTE were compared with an age‐, sex‐, and cardiovascular risk‐matched cohort of 4308 controls. The risk of mortality and major adverse cardiovascular events in patients with VTE was 2.23 (CI, 1.93–2.57; P<0.0001) and 1.86 (CI, 1.65–2.09; P<0.0001) times, respectively, higher than that of the conditions in controls. These events mostly occurred during the first year after the diagnosis of unprovoked VTE. Among patients with VTE, advanced age, male sex, and comorbid diabetes mellitus indicated a higher incidence of mortality and major adverse cardiovascular events. Conversely, comorbid hyperlipidemia attenuated these risks.

Conclusions

This nation‐wide cohort study revealed that patients with unprovoked VTE, particularly older males with diabetes mellitus, had an elevated risk of both mortality and cardiovascular events. Risk of mortality and major adverse cardiovascular events were highest within the first year after diagnosis and persisted during the 10 years of follow‐up.

The association of statin therapy with the risk of recurrent venous thrombosis

Essentials A lowered risk of recurrent venous thrombosis (VT) with statin treatment is controversial. Among observational inception cohort of 2,798 adults with incident VT, 457 had recurrent VT. Time-to-event models with time-varying statin use and adjustment for potential confounders was used for analysis. Compared to nonuse, current statin use was associated with 26% lower risk of recurrent VT. Click to hear Prof. Büller's perspective on Anticoagulant Therapy in the Treatment of Venous Thromboembolism

SUMMARY

Background Meta-analyses of randomized controlled trials suggest that treatment with hydroxymethylglutaryl-coenzyme A reductase inhibitors (statins) lowers the risk of incident venous thrombosis (VT), particularly among those without prevalent clinical cardiovascular disease (CVD). Whether this is true for the prevention of recurrent VT is debated. We used an observational inception cohort to estimate the association of current statin use with the risk of recurrent VT. Methods and Results The study setting was a large healthcare organization with detailed medical record and pharmacy information at cohort entry and throughout follow-up. We followed 2798 subjects 18-89 years of age who experienced a validated incident VT between January 1, 2002, and December 31, 2010, for a first recurrent VT, validated by medical record review. During follow-up, 457 (16%) developed a first recurrent VT. In time-to-event models incorporating time-varying statin use and adjusting for potential confounders, current statin use was associated with a 26% lower risk of recurrent VT: hazard ratio 0.74, 95% confidence interval 0.59-0.94. Among cohort members free of CVD (n = 2134), current statin use was also associated with a lower risk (38%) of recurrent VT: hazard ratio 0.62, 95% confidence interval 0.45-0.85. We found similar results when restricting to new users of statins and in subgroups of different statin types and doses. Conclusions In a population-based cohort of subjects who had experienced an incident VT, statin use, compared with nonuse, was associated with a clinically relevant lower risk of recurrent VT. These findings suggest a potential secondary benefit of statins among patients who have experienced an incident VT.

Venous and Arterial Thrombosis: Is There a Link?

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

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.

Is lipid lowering therapy an independent risk factor for venous thromboembolism? A population-based case-control study

INTRODUCTION

The independent effect of lipid lowering therapy (LLT) on venous thromboembolism (VTE) risk is uncertain.

OBJECTIVE

To test statin and non-statin LLT as potential VTE risk factors.

METHODS

Using Rochester Epidemiology Project resources, we identified all Olmsted County, MN residents with objectively diagnosed incident VTE (cases) over the 13-year period, 1988-2000 (n=1340), and one to two matched controls (n=1538). We reviewed their complete medical records for baseline characteristics previously identified as independent VTE risk factors, and for statin and non-statin LLT. Using conditional logistic regression, we tested the overall effect of LLT on VTE risk and also separately explored the role of statin versus that of non-statin LLT, adjusting for other baseline characteristics.

RESULTS

Among cases and controls, 74 and 111 received statin LLT, and 32 and 50 received non-statin LLT, respectively. Univariately, and after individually controlling for other potential VTE risk factors (i.e., BMI, trauma/fracture, leg paresis, hospitalization for surgery or medical illness, nursing home residence, active cancer, central venous catheter, varicose veins, prior superficial vein thrombosis, diabetes, congestive heart failure, angina/myocardial infarction, stroke, peripheral vascular disease, smoking, anticoagulation), LLT was associated with decreased odds of VTE (unadjusted OR=0.73; p=0.03). When considered separately, statin and non-statin LLT were each associated with moderate, non-significant lower odds of VTE. After adjusting for angina/myocardial infarction, each was significantly associated with decreased odds of VTE (OR=0.63, p<0.01 and OR=0.61, p=0.04, respectively).

CONCLUSIONS

LLT is associated with decreased VTE risk after adjusting for known risk factors.

Influence of statin use on the incidence of recurrent venous thromboembolism and major bleeding in patients receiving rivaroxaban or standard anticoagulant therapy

Background

Statins may reduce the risk of first and recurrent venous thromboembolism (VTE). No data are available on their potential benefit in patients treated with the oral anticoagulant rivaroxaban.

Methods

The EINSTEIN DVT/PE and EINSTEIN Extension studies compared rivaroxaban with standard of care (n=8280) and placebo (n=1188), respectively. The incidences of recurrent VTE and major bleeding per 100 patient-years for exposure (or not) to statins were calculated. A Cox proportional hazards model was constructed, stratified by index event and intended treatment duration, with statin use as a time-dependent variable, for each treatment group (rivaroxaban vs enoxaparin/vitamin K antagonist or placebo) and adjusted for relevant variables.

Results

In EINSTEIN DVT/PE, 1509 (18.3%) patients used statins during the at-risk period, and 6731 (81.7%) did not. Overall, 2.6 recurrent VTEs occurred per 100 patient-years with statin use compared with 3.8 per 100 patient-years without statins (adjusted hazard ratio [HR] 0.76; 95% confidence interval [CI] 0.46–1.25). HRs for recurrent VTE were similar for concomitant use of rivaroxaban-statin and enoxaparin/VKA-statin. Major bleeding events occurred in 3.0 per 100 patient-years with statin use compared with 2.3 per 100 patient-years without statins (adjusted HR 0.77; 95% CI 0.46–1.29). Due to adjustments in the Cox regression model, the direction of this HR is in contrast to the crude comparison. In EINSTEIN Extension, no recurrent VTEs occurred with statin use in the rivaroxaban group compared with 1.6 per 100 patient-years without statins. In the placebo group, 12.2 recurrent VTEs occurred per 100 patient-years with statin use compared with 13.2 per 100 patient-years without (adjusted HR 0.81; 95% CI 0.35–1.86).

Conclusions

The effect of statins in this secondary analysis of the EINSTEIN VTE treatment program is consistent with other studies that suggest a reduced risk of recurrent VTE, but conclusive evidence of this benefit is lacking. Statins are simple to use, inexpensive, very safe and do not cause bleeding. Therefore, the potential effect on reducing recurrent VTE, which is in the range of that of acetylsalicylic acid, deserves evaluation in a large randomized trial.

Trial registration number

ClinicalTrials.gov: EINSTEIN PE, NCT00439777; EINSTEIN DVT, NCT00440193; EINSTEIN Extension, NCT00439725.

Statin use and venous thromboembolism recurrence: a combined nationwide cohort and nested case-control study

BACKGROUND

Data on statins' effect on venous thromboembolism (VTE) recurrence are conflicting.

OBJECTIVES

We examined whether statin use was associated with reduced risk of recurrent VTE in a nationwide population-based setting.

PATIENTS/METHODS

Using the Danish National Patient Registry, we identified first-time and recurrent VTEs between 1 July 2004 and 31 December 2012 (n = 27,862). VTE diagnoses were validated by medical record review of a subsample of patients. We ascertained nationwide prescription data and categorized statin use as current (further divided into new and long-term use), former and no use. We identified statin use at baseline (mimicking an intention-to-treat analysis) and in a time-varying manner during follow-up (mimicking per-protocol analysis) and computed hazard ratios (HRs) for recurrent VTE using Cox regression. In a supplementary nested case-control study, we identified statin use at time of VTE recurrence and computed odds ratios as unbiased estimates of the incidence rate ratios (IRRs) using conditional logistic regression. We adjusted for age, sex, year of diagnosis, provoking factors, co-morbidities and co-medications, including time-varying use of aspirin and anticoagulant drugs.

RESULTS

The adjusted HR comparing current use with no use was 0.72 (95% confidence interval [CI], 0.59-0.88) for recurrent VTE, with a stronger effect of high (0.40; 95% CI, 0.21-0.78) vs. low potency statins (0.77; 95% CI, 0.63-0.94). Consistently, the recurrence rate was reduced in both the time-varying analysis (HR=0.64; 95% CI, 0.54-0.77) and nested case-control analysis (IRR=0.55; 95% CI, 0.45-0.67). The effect was largest for recurrent deep venous thrombosis.

CONCLUSIONS

Statin use was associated with reduced VTE recurrence.