Effect of statins on venous thromboembolic events: a meta-analysis of published and unpublished evidence from randomised controlled trials

Lipid lowering for prevention of venous thromboembolism: a network meta-analysis

BACKGROUND AND AIMS

Studies have suggested that statins may be associated with reduced risk of venous thromboembolism (VTE). The aim of the current study was to assess the evidence regarding the comparative effect of all lipid-lowering therapies (LLT) in primary VTE prevention.

METHODS

After a systematic search of PubMed, CENTRAL, and Web of Science up until 2 November 2022, randomized controlled trials (RCT) of statins (high- or low-/moderate-intensity), ezetimibe, or proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) were selected. An additive component network meta-analysis to compare VTE risk during long-term follow-up across different combinations of LLT was performed.

RESULTS

Forty-five RCTs (n = 254 933 patients) were identified, reporting a total of 2084 VTE events. Compared with placebo, the combination of PCSK9i with high-intensity statin was associated with the largest reduction in VTE risk (risk ratio [RR] 0.59; 95% confidence interval [CI] 0.43-0.80), while there was a trend towards reduction for high-intensity (0.84; 0.70-1.02) and low-/moderate-intensity (0.89; 0.79-1.00) statin monotherapy. Ezetimibe monotherapy did not affect the VTE risk (1.04; 0.83-1.30). There was a gradual increase in the summary effect of VTE reduction with increasing intensity of the LLT. When compared with low-/moderate-intensity statin monotherapy, the combination of PCSK9i and high-intensity statin was significantly more likely to reduce VTE risk (0.66; 0.49-0.89).

CONCLUSIONS

The present meta-analysis of RCTs suggests that LLT may have a potential for VTE prevention, particularly in high-intensity dosing and in combination therapy.

A pharmacoepidemiological nested case-control study of risk factors for venous thromboembolism with the focus on diabetes, cancer, socioeconomic group, medications, and comorbidities

OBJECTIVES

A pharmacoepidemiological study to assess VTE risk factors in a diabetes-rich population.

METHODS

The study comprised 299,590 individuals. We observed 3450 VTEs and matched them with 15,875 controls using a nested case-control approach and collected data on comorbidities and prescriptions. By multivariable conditional logistic regression, we calculated ORs with 95%CIs for comorbidities and medications to evaluate their associations with VTE.

RESULTS

Diabetes (aOR 2.16; 95%CI 1.99-2.34), inflammatory bowel disease (1.84; 1.27-2.66), and severe psychiatric disorders (1.72; 1.43-2.05) had the strongest associations among the non-cancer comorbidities. Pancreatic (12.32; 7.11-21.36), stomach (8.57; 4.07-18.03), lung and bronchus (6.26; 4.16-9.43), and ovarian (6.72; 2.95-15.10) cancers were ranked as high-risk for VTE. Corticosteroids, gabapentinoids, psychotropic drugs, risedronic acid, and pramipexole were most strongly associated (aOR exceeding 1.5) with VTE. Insulin (3.86; 3.33-4.47) and sulphonylureas (2.62; 2.18-3.16) had stronger associations than metformin (1.65; 1.49-1.83). Statins and lercanidipine (0.78; 0.62-0.98) were associated with a lowered risk of VTE.

CONCLUSIONS

In this cohort, with 50% diabetes prevalence, pancreatic, stomach, lung and bronchus, and ovarian cancers were strongly associated with VTE. Corticosteroids, gabapentinoids, and psychotropic medications had the strongest associations with VTE among medications. This may be valuable for generating hypotheses for the further research. Lercanidipine may be a novel protective medication against VTE.

Statin use in cirrhosis and its association with incidence of portal vein thrombosis

BACKGROUND AND AIM

Statin use has shown a reduction in hepatic decompensation and portal hypertension. Its association with portal vein thrombosis (PVT) incidence is unknown. We aim to compare the incidence of PVT in patients with and without statin use.

METHODS

We excluded patients with a history of hepatocellular cancer, liver transplants, Budd-Chiari syndrome, and intra-abdominal malignancies. Patients with cirrhosis were followed from their first hepatologist clinical encounter (January 1, 2016, to January 31, 2021) for 180 days to determine PVT incidence. We tested the association of statin use with PVT using 1:1 propensity score (PS) matching and Cox proportional hazard regression.

RESULTS

We analyzed 2785 patients with cirrhosis (mean age:61.0 ± 12.3 years, 44.3% female, 63.8% White, mean MELD-Na score:11.7 ± 6.1, and statin use:23.1%). A total of 89 patients developed PVT during the follow-up, which was lower in patients with statin use as compared to no statin use (1.3% vs 3.8%, P = 0.001, unadjusted HR:0.28, 95% CI: 0.13-0.62, P = 0.001). After matching for demographics, comorbidities, and hepatic decompensation events, patients with statin use had a lower risk of developing PVT in 180-day follow-up as compared to those without statin use (HR:0.24, 95% CI: 0.10-0.55, P = 0.001). Subgroup analysis showed that statin use was associated with lower PVT incidence in non-NASH (HR: 0.20, 95% CI: 0.07-0.54, P = 0.002) and decompensated cirrhosis (HR: 0.12, 95% CI:0.03-0.53, P = 0.005) than no statin use.

CONCLUSION

PVT incidence was lower in decompensated cirrhosis patients with statin use than in those with no statin use. However, this finding needs to be further tested in randomized control trials.

Risk of Venous Thromboembolism with Statins: Evidence Gathered via a Network Meta-analysis

Background

Anticoagulants are the mainstay of treatment for venous thromboembolism (VTE). Studies have shown conflicting results regarding statins ability to reduce the incidence of VTE.

Aims

To perform a network meta-analysis to determine which lipid-lowering agent was more efficacious in and had more evidence regarding reducing the VTE risk.

Study Design

Network meta-analysis of the randomized controlled trials (RCTs).

Methods

RCTs that assessed the effectiveness and safety of statins or fibrates and compared them to a placebo or another statin were eligible for the study. The outcomes examined in the study were deep vein thrombosis, pulmonary embolism, and/or VTE. We conducted a comprehensive search of the Medline database from 1966 to February 2017, using specific search terms related to VTE and statins. Additionally, we screened, and cross-checked relevant systematic reviews and meta-analyses. We performed a network meta-analysis to compare the different lipid-lowering agents to each other and the placebo and their effectiveness.

Results

Twenty-seven RCTs were included in the network meta-analysis (n = 137,940). Pairwise meta-analysis revealed a statistically significant lower incidence of VTE with statins than with placebos (0.79% vs 0.99%, respectively; risk ratios: 0.87, 0.77-0.98; p = 0.022). Rosuvastatin had the most favorable effect in reducing VTE risk than the other statins, fenofibrate, and placebo. Fenofibrate was ranked the worst drug choice, because it increased risk of VTE when compared with the other statins. Rosuvastatin was the best choice for reducing the VTE risk when compared with the placebo (OR: 0.56, 0.42-0.75), atorvastatin (OR: 0.64, 0.44-0.95), pravastatin (OR: 0.50, 0.34-0.74), simvastatin (OR: 0.60, 0.42-0.86) and fenofibrate (OR: 0.37, 0.25-0.56). Compared with a placebo, rosuvastatin reduced the VTE risk by around 45% and fenofibrate increased the risk by 65%.

Conclusion

Rosuvastatin is significantly reduces the risk of VTE when compared with a placebo, other statin subtypes, and fibrate. Furthermore, fenofibrate increased the VTE risk when compared with a placebo and statins.

Blood pressure and risk of venous thromboembolism: a cohort analysis of 5.5 million UK adults and Mendelian randomization studies

AIMS

Evidence for the effect of elevated blood pressure (BP) on the risk of venous thromboembolism (VTE) has been conflicting. We sought to assess the association between systolic BP and the risk of VTE.

METHODS AND RESULTS

Three complementary studies comprising an observational cohort analysis, a one-sample and two-sample Mendelian randomization were conducted using data from 5 588 280 patients registered in the Clinical Practice Research Datalink (CPRD) dataset and 432 173 UK Biobank participants with valid genetic data. Summary statistics of International Network on Venous Thrombosis genome-wide association meta-analysis was used for two-sample Mendelian randomization. The primary outcome was the first occurrence of VTE event, identified from hospital discharge reports, death registers, and/or primary care records. In the CPRD cohort, 104 017(1.9%) patients had a first diagnosis of VTE during the 9.6-year follow-up. Each 20 mmHg increase in systolic BP was associated with a 7% lower risk of VTE [hazard ratio: 0.93, 95% confidence interval (CI): (0.92-0.94)]. Statistically significant interactions were found for sex and body mass index, but not for age and subtype of VTE (pulmonary embolism and deep venous thrombosis). Mendelian randomization studies provided strong evidence for the association between systolic BP and VTE, both in the one-sample [odds ratio (OR): 0.69, (95% CI: 0.57-0.83)] and two-sample analyses [OR: 0.80, 95% CI: (0.70-0.92)].

CONCLUSION

We found an increased risk of VTE with lower BP, and this association was independently confirmed in two Mendelian randomization analyses. The benefits of BP reduction are likely to outweigh the harms in most patient groups, but in people with predisposing factors for VTE, further BP reduction should be made cautiously.

Postoperative statin therapy is not associated with reduced incidence of venous thromboembolic events following kidney transplantation

BACKGROUND

The pleiotropic effects of statin therapy on inflammation and coagulation may reduce the risk of venous thromboembolism. This study evaluated whether statin therapy is associated with decreased venous thromboembolic (VTE) events following kidney transplantation.

METHODS

We performed a retrospective analysis of all primary kidney transplants performed between January 2014 and December 2019 at Mayo Clinic Arizona. Patients were divided into two groups depending on sustained statin therapy during the first year following transplantation. Recipient and donor clinical and demographic data were collected. The primary outcome was admission for symptomatic VTE events (deep vein thrombosis [DVT] or pulmonary embolism [PE]).

RESULTS

Sustained statin therapy in the first year following transplant was observed in 16.1% (n = 223) of 1384 kidney transplants. The overall incidence of VTE events in the year following kidney transplant was 3.8%. VTE occurred in 4.1% of recipients treated with statins and 3.8% of the controls - (hazard ratio [HR] .92, 95% confidence interval [95% CI] .39, 2.21, p = .86). However, there were significant differences between the groups in terms of age, sex, race/ethnicity, body mass index, indication for transplant, diagnosis of diabetes and discharge antiplatelet or anticoagulant therapy. Following sensitivity analysis in which cohort matching was performed to account for these differences, there was no difference in VTE event-free survival (HR .89, 95% CI .41, 1.96, p = .78) or overall survival (HR .54, 95% CI .15, 1.94, p = .35) between patients treated with statins compared to controls.

CONCLUSION

Statin therapy in the year following successful kidney transplant was not associated with a reduction in risk of VTE.

Rosuvastatin treatment decreases plasma procoagulant phospholipid activity after a VTE: A randomized controlled trial

BACKGROUND

Venous thromboembolism (VTE) is a frequent cardiovascular disease with severe complications, including recurrence and death. There is a great need for alternative prophylactic treatment options as anticoagulation is accompanied by increased bleeding risk. Statins are reported to reduce the risk of incident and recurrent VTE, but the mechanisms are elusive. Procoagulant phospholipids (PPL), and phosphatidylserine in particular, are crucial for efficient coagulation activation, but no studies have investigated the effect of statin treatment on plasma PPL activity.

OBJECTIVES

To investigate the impact of rosuvastatin treatment on plasma PPL activity and levels of extracellular vesicles (EVs).

PATIENTS/METHODS

Patients with a history of VTE (≥18 years) allowed to stop anticoagulant treatment were randomized to either 20 mg/day of rosuvastatin treatment or no treatment for 28 days in the Statins Reduce Thrombophilia (NCT01613794) trial. Plasma samples were collected at baseline and study end. PPL activity was measured in samples from 245 participants using a factor Xa-dependent clotting assay and EV levels by flow cytometry.

RESULTS

Rosuvastatin treatment yielded an overall 22% (95% confidence interval [CI] -38.2 to -5.8) reduction in PPL activity, and 37% (95% CI -62.9 to -11.2) reduction in PPL activity in participants with a history of pulmonary embolism. The effect of rosuvastatin on plasma PPL activity was not explained by changes in total cholesterol nor change in levels of total- or platelet-derived EVs.

CONCLUSIONS

Rosuvastatin treatment caused a substantial decrease in plasma PPL activity, suggesting that a PPL-dependent attenuation of coagulation activation may contribute to a reduced VTE risk following statin treatment.

Serum Albumin and Circulating Metabolites and Risk of Venous Thromboembolism: A Two-Sample Mendelian Randomization Study

Background and Aim: Previous observational studies indicated that the serum albumin levels and circulating metabolites are associated with a high risk of venous thromboembolism (VTE). However, whether these observations reflect causality remained unclear. Hence, we conducted a two-sample Mendelian randomization (MR) analysis to evaluate the causal associations of serum albumin and circulating metabolites with the risk of VTE.

Methods and Results: Summary statistics of genetic instruments proxying serum albumin, total protein, and common circulating metabolites were extracted from genome-wide association studies in the European ancestry. Summary-level results of age- and sex-adjusted estimates for associations of the instruments with VTE were derived from the FinnGen consortium. We used the inverse-variance weighted (IVW) method as the primary analysis for univariable MR. Sensitivity analyses were performed to detect horizontal pleiotropy and outliers. Genetically proxied high-serum albumin and total protein levels were suggestive protective factor of VTE, with odds ratio (OR) = 0.69 (CI 0.54–0.89, p = 4.7 × 10⁻³) and 0.76 (CI 0.61–0.95, p = 0.015), respectively. Genetically proxied low-monounsaturated fatty acids and the ratio of monounsaturated fatty acid to total fatty acid are causally associated with increased risk of VTE, with ORs = 0.89 (CI 0.80–0.99, p = 0.031) and 0.85 (CI 0.78–0.94, p = 9.92 × 10⁻⁴), respectively. There is no indication of causal associations between other circulating metabolites and the risk of VTE.

Conclusions: Genetically liability to low-serum albumin and total protein levels, low proxied monounsaturated fatty acids (MUFAs) and the ratio of MUFAs to total fatty acids are associated with the higher risk of VTE.

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.

Statin Therapy and the Incidence of Thromboembolism and Vascular Events Following Liver Transplantation

Statin therapy may reduce the risk of venous thromboembolism (VTE), which may impact solid organ transplant outcomes. We evaluated the incidence of VTE and other complications after liver transplantation stratified by hyperlipidemia status and statin use using a retrospective cohort study approach. We reviewed all primary orthotopic liver transplantation (OLT) records from January 2014 to December 2019 from our center. Intraoperative deaths were excluded. Recipient, donor clinical and demographic data were collected. We developed risk-adjusted models to assess the effect of statin use on the occurrence of VTE, hepatic artery complications (HACs), graft failure, and death, accounting for clinical covariates and competing risks. A total of 672 OLT recipients were included in the analysis. Of this cohort, 11.9% (n = 80) received statin therapy. A total of 47 patients (7.0%) had VTE events. HACs occurred in 40 patients (6.0%). A total of 42 (6.1%) patients experienced graft loss, whereas 9.1% (n = 61) of the cohort died during the study interval. Eighty OLT recipients (29.8%) were treated with statins. In the statin treated group, 0% of patients had VTE versus 7.9% of those not on statins (P = 0.02). HACs were identified in 1.2% of the statin group and 6.8% of the nonstatin group. Untreated hyperlipidemia was associated with a 2.1-fold higher risk of HACs versus patients with no hyperlipidemia status (P = 0.05). Statin therapy was associated with significantly better risk-adjusted thromboembolic event-free survival (absence of VTE, cerebrovascular accident, myocardial infarction, HACs, and death); hazard ratio, 2.7; P = 0.01. These data indicate that statin therapy is correlated with a lower rate of VTE and HACs after liver transplantation.

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.

Differential effect of statin use on coagulation markers: an active comparative analysis in the NEO study

Background

Statins are a potential treatment for venous thromboembolism (VTE) prophylaxis complementary to conventional anticoagulants without associated bleeding complications. This study aimed to compare pro-thrombotic activities of different classes of lipid-lowering drugs in an active comparator design and determine whether there is a relation between statin versus fibrate/niacin use and pro-coagulant factor outcomes.

Methods

This is a cross-sectional analysis of participants from the Netherlands Epidemiology of Obesity study using any class of lipid-lowering drugs, including any types of statins, niacin, and fibrates. We performed linear regression analyses to determine fibrinogen, factor (F) VIII, FIX, and FXI activity in statins versus fibrate/niacin users and adjusted for age, sex, tobacco smoking, body mass index (BMI), hypertension, diabetes, and prevalent cardiovascular disease.

Results

Among 1043 participants, the mean age was 58.4 ± 5.2 years, 61% were men, and the mean BMI was 31.3 ± 4.5 kg/m². Clinical characteristics were balanced between statin and fibrate/niacin users. Statin users had lower mean FXI (18.3 IU/dL, 95% confidence interval (CI) 9.4 to 27.3) levels compared to fibrate/niacin users. The level of FVIII (15.8 IU/dL, 95% CI − 0.003 to 31.6), and FIX (11.3 IU/dL, 95% CI − 0.4 to 23.2) were lower in statin users than fibrate/niacin users with marginal statistical significance.

Conclusion

Current statin use was associated with lower plasma levels of FXI than fibrate/niacin use. The effects on coagulation factors may, in part, explain the benefit of statin therapy rendered in primary and secondary prevention of VTE.

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 Effect of PCSK9 (Proprotein Convertase Subtilisin/Kexin Type 9) Inhibition on the Risk of Venous Thromboembolism

BACKGROUND

The relationship between cholesterol levels and risk of venous thromboembolism (VTE) is uncertain. We set out to determine the effect of PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibition on the risk of VTE, explore potential mechanisms, and examine the efficacy in subgroups with clinically and genetically defined risk.

METHODS

We performed a post hoc analysis of the FOURIER trial (Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Subjects With Elevated Risk) testing whether evolocumab reduces the risk of VTE events (deep venous thrombosis or pulmonary embolism). Data from FOURIER and ODYSSEY OUTCOMES (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment with Alirocumab) were then combined in a meta-analysis to assess the class effect of PCSK9 inhibition on the risk of VTE. We also analyzed baseline lipids in FOURIER to investigate potential mechanisms explaining the reduction in VTE with evolocumab. Last, an exploratory genetic analysis was performed in FOURIER to determine whether a VTE polygenic risk score could identify high-risk patients who would derive the greatest VTE reduction from evolocumab.

RESULTS

In FOURIER, the hazard ratio (HR) for VTE with evolocumab was 0.71 (95% CI, 0.50-1.00; P=0.05), with no effect in the 1st year (HR, 0.96 [95% CI, 0.57-1.62]) but a 46% reduction (HR, 0.54 [95% CI, 0.33-0.88]; P=0.014) beyond 1 year. A meta-analysis of FOURIER and ODYSSEY OUTCOMES demonstrated a 31% relative risk reduction in VTE with PCSK9 inhibition (HR, 0.69 [95% CI, 0.53-0.90]; P=0.007). There was no relation between baseline low-density lipoprotein cholesterol levels and magnitude of VTE risk reduction. In contrast, in patients with higher baseline lipoprotein(a) (Lp[a]) levels, evolocumab reduced Lp(a) by 33 nmol/L and risk of VTE by 48% (HR, 0.52 [95% CI, 0.30-0.89]; P=0.017), whereas, in patients with lower baseline Lp(a) levels, evolocumab reduced Lp(a) by only 7 nmol/L and had no effect on VTE risk (Pinteraction 0.087 for HR; Pheterogeneity 0.037 for absolute risk reduction). Modeled as a continuous variable, there was a significant interaction between baseline Lp(a) concentration and magnitude of VTE risk reduction (Pinteraction=0.04). A polygenic risk score identified patients who were at >2-fold increased risk for VTE and who derived greater relative (Pinteraction=0.04) and absolute VTE reduction (Pheterogeneity=0.009) in comparison with those without high genetic risk.

CONCLUSIONS

PCSK9 inhibition significantly reduces the risk of VTE. Lp(a) reduction may be an important mediator of this effect, a finding of particular interest given the ongoing development of potent Lp(a) inhibitors.

Rosuvastatin use improves measures of coagulation in patients with venous thrombosis

Aims

Observational studies indicate that statins reduce the risk of recurrent venous thrombosis (VT). However, trials have not been performed and the mechanism is unknown. We aimed to determine whether statin therapy improves the coagulation profile in patients with prior VT.

Methods and results

Randomized clinical trial (NCT01613794). Patients were randomized to rosuvastatin 20 mg/day for 4 weeks or no intervention. Blood was drawn at baseline and at end of study. The primary outcome was factor (F) VIII:C. In total, five coagulation factors were measured: FVIII:C, von Willebrand factor:Ag, FVII:C, FXI:C, and D-dimer. Among 247 randomized participants, mean age was 58 years, 62% were women and 49% had unprovoked VT. For all tested coagulation factors, mean levels were clearly decreased at end of study in rosuvastatin users, whereas they hardly differed in non-statin users. Results were most consistent for FVIII:C where mean FVIII:C levels were 7.2 IU/dL [95% CI (confidence interval) 2.9-11.5] lower in rosuvastatin users, while among non-users, no change in FVIII:C was observed (mean difference -0.1; 95% CI -3.0 to 2.9). The mean age and sex adjusted difference in FVIII:C change was -6.7 IU/dL (95% CI -12.0 to -1.4) in rosuvastatin users vs. non-users. Subgroup analyses revealed that the decrease in coagulation factors by rosuvastatin was more pronounced in participants with unprovoked VT and in those with cardiovascular risk factors.

Conclusion

Rosuvastatin 20 mg/day substantially improved the coagulation profile among patients with prior VT. These results suggest that statin therapy might be beneficial in patients at risk of recurrent VT.

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.

Simvastatin protects photoreceptors from oxidative stress induced by all-trans-retinal, through the up-regulation of interphotoreceptor retinoid binding protein

BACKGROUND AND PURPOSE

Simvastatin is a 3-hydroxy-3-methylglutaryl CoA reductase inhibitor with multiple targets and effects. It protects neurons in the brain, but its protective effects on photoreceptors are unclear. In this study, we evaluated the neuroprotective effect of simvastatin on photoreceptors exposed to stress induced by all-trans-retinal (atRAL).

EXPERIMENTAL APPROACH

AlamarBlue and LDH assays were used to evaluate the viability and metabolic activity of Y79 cells (a retinoblastoma cell line) exposed to atRAL-induced stress with or without simvastatin pretreatment. Changes in cellular ROS were evaluated using flow cytometry and mitochondrial stress markers JC-1 and HSP60. Changes in levels of two photoreceptor-specific markers, cone-rod homeobox protein (CRX) and interphotoreceptor retinoid binding protein (IRBP), were evaluated with western blot. The results were validated in ex vivo human retinal explants and a mouse model of photoreceptor degeneration.

KEY RESULTS

Simvastatin improved mitochondrial function, alleviated oxidative stress and up-regulated the photoreceptor-specific markers IRBP and its upstream regulator CRX in Y79 cells and ex vivo human retinal explants under atRAL-induced stress. Simvastatin attenuated photoreceptor degeneration in association with up-regulation of IRBP and CRX expression after knockdown of IRBP in a murine model.

CONCLUSION AND IMPLICATIONS

Our findings suggest that simvastatin has a novel role in protecting photoreceptors from atRAL-induced stress. Simvastatin treatment resulted in up-regulation of IRBP and its upstream transcription factor CRX in Y79 cells, ex vivo human retinal explants, and murine retinas in vivo. Further studies of simvastatin to treat photoreceptor degeneration are warranted.

Investigating the stratified efficacy and safety of pharmacological blood pressure-lowering: an overall protocol for individual patient-level data meta-analyses of over 300 000 randomised participants in the new phase of the Blood Pressure Lowering Treatment Trialists' Collaboration (BPLTTC)

INTRODUCTION

Previous research from the Blood Pressure Lowering Treatment Trialists' Collaboration (BPLTTC) and others has shown that pharmacological blood pressure (BP)- lowering substantially reduces the risk of major cardiovascular events, including ischaemic heart disease, heart failure and stroke. In this new phase, the aim is to conduct individual patient-level data (IPD) meta-analyses involving eligible BP-lowering randomised controlled trials (RCTs) to address uncertainties relating to efficacy and safety of BP-lowering treatment.

METHODS AND ANALYSIS

RCTs investigating the effect of pharmacological BP-lowering, with a minimum of 1000 patient-years of follow-up in each trial arm, are eligible. Our systematic review identified 100 potentially eligible trials. We requested their investigators/sponsors to contribute baseline, follow-up and outcomes data. As of June 2018, the collaboration has obtained data from 49 trials (n=315 046 participants), with additional data currently in the process of being transferred from four RCTs (n=34 642 participants). In addition, data harmonisation has commenced. Scientific activities of the collaboration are overseen by the Steering Committee with input from all collaborators. Detailed protocols for individual meta-analyses will be developed and registered on public platforms.

ETHICS AND DISSEMINATION

Ethics approval has been obtained for this new and extended phase of the BPLTTC, the largest collaboration of de-identified IPD from RCTs. It offers an efficient and ethical manner of re-purposing existing data to answer clinically important questions relating to BP treatment as well as methodological questions relating to IPD meta-analyses. Among the immediate impacts will include reliable quantification of effects of treatment modifiers, such as baseline BP, age and prior disease, on both vascular and non-vascular outcomes. Analyses will further assess the impact of BP-lowering on important, but less well understood, outcomes, such as new-onset diabetes and renal disease. Findings will be published in peer-reviewed medical journals on behalf of the collaboration.

Rosuvastatin use reduces thrombin generation potential in patients with venous thromboembolism: a randomized controlled trial

Essentials The role of statins in hemostasis and venous thromboembolism (VTE) prophylaxis is not clear. This trial assessed whether rosuvastatin use affects thrombin generation in patients with VTE. Endogenous thrombin potential and peak were decreased by 10% and 5% with rosuvastatin therapy. These results provide basis for trials on the efficacy of statins in reducing recurrent VTE risk. SUMMARY: Background Statin therapy could form an alternative prophylactic treatment for venous thromboembolism (VTE) if statins are proven to downregulate hemostasis and prevent recurrent VTE, without increasing bleeding risk. Objectives The STAtins Reduce Thrombophilia (START) trial investigated whether statin affects coagulation in patients with prior VTE. Patients/methods After anticoagulation withdrawal, patients were randomized to rosuvastatin 20 mg day-1 for 4 weeks or no intervention. Plasma samples taken at baseline and at the end of the study were analyzed employing thrombin generation assay. Results and conclusions The study comprised 126 rosuvastatin users and 119 non-users. Mean age was 58 years, 61% were men, 49% had unprovoked VTE and 75% had cardiovascular (CV) risk factors. Endogenous thrombin potential (ETP) increased from baseline to end of study in non-statin users (mean 97.22 nm*min; 95% CI, 40.92-153.53) and decreased in rosuvastatin users (mean -24.94 nm*min; 95% CI, -71.81 to 21.93). The mean difference in ETP change between treatments was -120.24 nm*min (95% CI, -192.97 to -47.51), yielding a 10.4% ETP reduction by rosuvastatin. The thrombin peak increased in both non-statin (mean 20.69 nm; 95% CI, 9.80-31.58) and rosuvastatin users (mean 8.41 nm; 95% CI -0.86 to 17.69). The mean difference in peak change between treatments was -11.88 nm (95% CI, -26.11 to 2.35), yielding a 5% peak reduction by rosuvastatin. Other thrombin generation parameters did not change substantially. The reduction in ETP and peak by rosuvastatin was more pronounced in the subgroups of participants with CV risk factors and with unprovoked VTE. We conclude that rosuvastatin reduces thrombin generation potential in patients who had VTE.

Statins, haemostatic factors and thrombotic risk

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Usefulness of Statins for Prevention of Venous Thromboembolism

Venous thromboembolism (VTE), including deep venous thrombosis and pulmonary embolism, is common with an annual incidence of 1 to 5 per 1,000, resulting in major morbidity, mortality, and increased health care costs. It is more common in the elderly, obese, those with cancer, those undergoing surgery, and those with previous VTE. Strategy to reduce its occurrence has important public health implications. Pleotropic effects of statins may have beneficial effects on a number of potential targets associated with VTE. Statins have excellent safety profile and seem to be associated with beneficial effects in VTE in case-control studies, large observational studies, meta-analyses, and a randomized trial. In conclusion, after critically reviewing the clinical data supporting statin use in the prevention of VTE, we presented clinical recommendations for the use of statins in reducing VTE occurrence, especially in high-risk situations.

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.

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.

Search for unpublished data by systematic reviewers: an audit

OBJECTIVES

We audited a selection of systematic reviews published in 2013 and reported on the proportion of reviews that researched for unpublished data, included unpublished data in analysis and assessed for publication bias.

DESIGN

Audit of systematic reviews.

DATA SOURCES

We searched PubMed and Ovid MEDLINE In-Process & Other Non-Indexed Citations between 1 January 2013 and 31 December 2013 for the following journals: Journal of the American Medical Association, The British Medical Journal, Lancet, Annals of Internal Medicine and the Cochrane Database of Systematic Reviews. We also searched the Cochrane Library and included 100 randomly selected Cochrane reviews.

ELIGIBILITY CRITERIA

Systematic reviews published in 2013 in the selected journals were included. Methodological reviews were excluded.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently reviewed each included systematic review. The following data were extracted: whether the review searched for grey literature or unpublished data, the sources searched, whether unpublished data were included in analysis, whether publication bias was assessed and whether there was evidence of publication bias.

MAIN FINDINGS

203 reviews were included for analysis. 36% (73/203) of studies did not describe any attempt to obtain unpublished studies or to search grey literature. 89% (116/130) of studies that sought unpublished data found them. 33% (68/203) of studies included an assessment of publication bias, and 40% (27/68) of these found evidence of publication bias.

CONCLUSION

A significant fraction of systematic reviews included in our study did not search for unpublished data. Publication bias may be present in almost half the published systematic reviews that assessed for it. Exclusion of unpublished data may lead to biased estimates of efficacy or safety in systematic reviews.

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.

Lipid levels and risk of venous thrombosis: results from the MEGA-study

The relationship between lipid levels and risk of venous thrombosis is not well established. We aimed to assess the association between several lipids and risk of venous thrombosis using data from a population-based case-control study, and to evaluate the underlying mechanism, considering confounding by common risk factors and mediation via hemostatic factors and C-reactive protein. From the Multiple Environmental and Genetic Assessment of risk factors for venous thrombosis (MEGA) study, 2234 patients with a first venous thrombosis and 2873 controls were included. Percentile categories of total/low-density lipoprotein/high-density lipoprotein cholesterol, triglycerides, and apolipoproteins B and A1 were established in controls (<10th, 10th-25th, 25th-75th [reference], 75th-90th, >90th percentile). In age- and sex-adjusted models, decreasing levels of apolipoproteins B and A1 were dose-dependently associated with increased thrombosis risk, with odds ratios of 1.35 (95% confidence interval 1.12-1.62) and 1.50 (95% confidence interval 1.25-1.79) for the lowest category versus the reference category, respectively. The dose-response relation remained with further adjustment for body mass index, estrogen use, statin use, and diabetes. Although apolipoproteins B and A1 were associated with several hemostatic factors and C-reactive protein, none explained the increased risk in mediation analyses. The other lipids were not associated with venous thrombosis risk. In conclusion, decreasing levels of apolipoproteins B and A1 were associated with increased risk of venous thrombosis. Our findings are consistent with experimental data on the anticoagulant properties of apolipoproteins B and A1. These findings need to be confirmed and the underlying mechanism further investigated.

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.

Interpretation of the evidence for the efficacy and safety of statin therapy

This Review is intended to help clinicians, patients, and the public make informed decisions about statin therapy for the prevention of heart attacks and strokes. It explains how the evidence that is available from randomised controlled trials yields reliable information about both the efficacy and safety of statin therapy. In addition, it discusses how claims that statins commonly cause adverse effects reflect a failure to recognise the limitations of other sources of evidence about the effects of treatment. Large-scale evidence from randomised trials shows that statin therapy reduces the risk of major vascular events (ie, coronary deaths or myocardial infarctions, strokes, and coronary revascularisation procedures) by about one-quarter for each mmol/L reduction in LDL cholesterol during each year (after the first) that it continues to be taken. The absolute benefits of statin therapy depend on an individual's absolute risk of occlusive vascular events and the absolute reduction in LDL cholesterol that is achieved. For example, lowering LDL cholesterol by 2 mmol/L (77 mg/dL) with an effective low-cost statin regimen (eg, atorvastatin 40 mg daily, costing about £2 per month) for 5 years in 10 000 patients would typically prevent major vascular events from occurring in about 1000 patients (ie, 10% absolute benefit) with pre-existing occlusive vascular disease (secondary prevention) and in 500 patients (ie, 5% absolute benefit) who are at increased risk but have not yet had a vascular event (primary prevention). Statin therapy has been shown to reduce vascular disease risk during each year it continues to be taken, so larger absolute benefits would accrue with more prolonged therapy, and these benefits persist long term. The only serious adverse events that have been shown to be caused by long-term statin therapy-ie, adverse effects of the statin-are myopathy (defined as muscle pain or weakness combined with large increases in blood concentrations of creatine kinase), new-onset diabetes mellitus, and, probably, haemorrhagic stroke. Typically, treatment of 10 000 patients for 5 years with an effective regimen (eg, atorvastatin 40 mg daily) would cause about 5 cases of myopathy (one of which might progress, if the statin therapy is not stopped, to the more severe condition of rhabdomyolysis), 50-100 new cases of diabetes, and 5-10 haemorrhagic strokes. However, any adverse impact of these side-effects on major vascular events has already been taken into account in the estimates of the absolute benefits. Statin therapy may cause symptomatic adverse events (eg, muscle pain or weakness) in up to about 50-100 patients (ie, 0·5-1·0% absolute harm) per 10 000 treated for 5 years. However, placebo-controlled randomised trials have shown definitively that almost all of the symptomatic adverse events that are attributed to statin therapy in routine practice are not actually caused by it (ie, they represent misattribution). The large-scale evidence available from randomised trials also indicates that it is unlikely that large absolute excesses in other serious adverse events still await discovery. Consequently, any further findings that emerge about the effects of statin therapy would not be expected to alter materially the balance of benefits and harms. It is, therefore, of concern that exaggerated claims about side-effect rates with statin therapy may be responsible for its under-use among individuals at increased risk of cardiovascular events. For, whereas the rare cases of myopathy and any muscle-related symptoms that are attributed to statin therapy generally resolve rapidly when treatment is stopped, the heart attacks or strokes that may occur if statin therapy is stopped unnecessarily can be devastating.

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.

Platelet reactivity in patients with venous thrombosis who use rosuvastatin: a randomized controlled clinical trial

Essentials Statins, especially rosuvastatin, may reduce venous thrombosis risk, but the mechanism is unclear. We performed a randomized trial investigating the effect of rosuvastatin on platelet reactivity. Thromboxane-A2 mediated platelet aggregation was measured before and after rosuvastatin therapy. Rosuvastatin did not inhibit thromboxane-mediated platelet aggregation in venous thrombosis patients.

SUMMARY

Background Statins may exert a protective effect against the risk of venous thrombosis (VT), but the mechanism is unclear. Objectives In this open-label, randomized clinical trial (www.clinicaltrials.gov NCT01613794), we aimed to determine the ex vivo effect of rosuvastatin on platelet reactivity in patients with a history of VT. Methods Platelet reactivity, in platelet reaction units (PRUs), was measured at baseline and after 28 days with VerifyNow, which uses arachidonic acid to determine thromboxane-mediated platelet aggregation, in 50 consecutive patients included in our study (25 receiving rosuvastatin and 25 without intervention). Results Forty-seven of 50 (94.0%) consecutively enrolled patients had two valid PRU measurements. The mean PRUs in rosuvastatin users were 609 at baseline and 613 at the end of the study (mean change 5; 95% confidence interval [CI] - 18 to 27). The mean PRUs in non-users were 620 at baseline and 618 at the end of the study (mean change - 2; 95% CI - 15 to 12). The mean difference in PRU change between users and non-users was 6 (95% CI - 20 to 33). After exclusion of patients who used antiplatelet medication, or had thrombocytopenia, similar results were obtained, i.e. no apparent effect of rosuvastatin on PRUs, with a mean difference in PRU change between users and non-users of - 1 (95% CI - 20 to 19). Conclusions Rosuvastatin does not affect platelet reactivity when arachidonic acid is used as an agonist in patients with a history of VT.

Inhibition of Rab prenylation by statins induces cellular glycosphingolipid remodeling

Statins, which specifically inhibit HMG Co-A reductase, the rate-limiting step of cholesterol biosynthesis, are widely prescribed to reduce serum cholesterol and cardiac risk, but many other effects are seen. We now show an effect of these drugs to induce profound changes in the step-wise synthesis of glycosphingolipids (GSLs) in the Golgi. Glucosylceramide (GlcCer) was increased several-fold in all cell lines tested, demonstrating a widespread effect. Additionally, de novo or elevated lactotriaosylceramide (Lc3Cer; GlcNAcβ1-3Galβ1-4GlcCer) synthesis was observed in 70%. Western blot showed that GlcCer synthase (GCS) was elevated by statins, and GCS and Lc3Cer synthase (Lc3S) activities were increased; however, transcript was elevated for Lc3S only. Supplementation with the isoprenoid precursor, geranylgeranyl pyrophosphate (GGPP), a downstream product of HMG Co-A reductase, reversed statin-induced glycosyltransferase and GSL elevation. The Rab geranylgeranyl transferase inhibitor 3-PEHPC, but not specific inhibitors of farnesyl transferase, or geranylgeranyl transferase I, was sufficient to replicate statin-induced GlcCer and Lc3Cer synthesis, supporting a Rab prenylation-dependent mechanism. While total cholesterol was unaffected, the trans-Golgi network (TGN) cholesterol pool was dissipated and medial Golgi GCS partially relocated by statins. GSL-dependent vesicular retrograde transport of Verotoxin and cholera toxin to the Golgi/endoplasmic reticulum were blocked after statin or 3-PEHPC treatment, suggesting aberrant, prenylation-dependent vesicular traffic as a basis of glycosyltransferase increase and GSL remodeling. These in vitro studies indicate a previously unreported link between Rab prenylation and regulation of GCS activity and GlcCer metabolism.

Use of statins and reduced risk of recurrence of VTE in an older population. A population-based cohort study

We aimed to determine whether statin use is associated with a decreased risk of recurrent venous thromboembolism (VTE) in older patients. We used a pre-assembled cohort of patients at least 65 years of age diagnosed with incident VTE between January 1, 1994 and December 31, 2004 in the province of Québec, Canada and followed until December 31, 2005. Time-dependent Cox proportional hazards models were used to estimate adjusted hazard ratios (HRs) and 95 % confidence intervals (CIs) of recurrent VTE associated with current and past use of statins, compared with non-use. The cohort included 25,681 patients with incident VTE. During a mean follow-up of 3.0 years, there were 2343 recurrent VTE events (rate: 3.1 per 100 person-years). Compared with non-use, current use of statins was associated with a decreased risk of VTE recurrence (rates: 1.55 vs 3.47 per 100 per year, respectively; HR: 0.74, 95 % CI: 0.61-0.89), while no association was observed with past use (HR: 0.98, 95 % CI: 0.76-1.25). In a secondary analysis, longer durations of statin use were associated with greater risk reductions (0-6 months, HR 0.82, 95 % CI: 0.67-1.01; 6-12 months, HR 0.62, 95 % CI: 0.43-0.90; ≥ 12 months, HR: 0.50, 95 % CI: 0.33-0.74; p-value for trend ≤ 0.001). The use of statin was associated with a decreased risk of recurrent VTE in older patients. This study supports the need for randomised controlled trials to assess the efficacy and safety of statins in the long-term treatment of VTE.

Does the use of statins improve outcomes in coronary artery bypass graft surgery?

Statins (3-hydroxy-3-methylglutaryl CoA reductase inhibitors) are one of the most frequently prescribed medications throughout the world with beneficial effects that extend beyond their lipid-lowering activity. It has been suggested that statins may offer a simple and cost-effective strategy to reduce some of the complications that occur in association with coronary artery bypass graft (CABG) surgery. Limited existing randomized trial evidence in the setting of cardiac surgery suggests that statins may reduce the incidence of postoperative atrial fibrillation. However, any effect of statins on other outcomes is less clear. The clinical significance of specific statin agent and dose, acute statin withdrawal and the potential benefits associated with statin reloading remain important yet currently unresolved issues. Despite limited high-quality evidence, class I recommendations have been made that all patients undergoing coronary artery bypass graft surgery should receive statin therapy unless contraindicated.