Differential effects of short-term lipid lowering with ezetimibe and statins on endothelial function in patients with CAD: clinical evidence for 'pleiotropic' functions of statin therapy

Enhancing the human health and lifespan: a targeted strategy emphasizing statins

There has been substantial research interest in finding activities/agents that slow the onset and reduce the severity of numerous age-related diseases/conditions. This assessment indicates that the most studied agent intended to promote health in human population investigations for a broad spectrum of diseases are the statins, with large-scale epidemiological studies addressing numerous health endpoints. The key findings are that statin treatment consistently reduces the occurrence and attenuates the course of numerous non-communicable and contagious pathologies and numerous types of cancer with high mortality rates by about 20-50%. That one agent could affect such a broad based and consistently positive trends in epidemiological studies is unexpected and impressive, along with consistent cell and animal model research. Underlying mechanisms have been proposed that significantly contribute to the spectrum of salutary effects of statins, especially the capacity to activate Nrf2 showing hormetic dose responses in multiple organs and cell types, due to its bioavailability and broad tissue distribution. The widespread use of statins, which has the capacity to enhance human health span, should be considered for experimental exploration as a novel public health strategy that includes practical approaches for reduction of the most common adverse effects of this class of drugs including myalgia/myopathy and transaminitis.

Understanding the molecular mechanisms of statin pleiotropic effects

Statins represent the cornerstone of pharmacotherapy for the prevention of atherosclerotic cardiovascular disease. These medications not only reduce low-density lipoprotein cholesterol (LDL-C) via inhibition of 3-hydroxy-3-methylglutarate attached to CoA reductase, the key rate-limiting step in the cholesterol biosynthetic pathway, but also upregulate expression of the low-density lipoprotein receptor, improving serum clearance. Given LDL-C is a causal risk factor for the development of atherosclerosis, these complementary mechanisms largely explain why statin therapy leads to reductions in major adverse cardiovascular events. However, decades of basic and clinical research have suggested that statins may exert other effects independent of LDL-C lowering, termed pleiotropic effects, which have become a topic of debate among the scientific community. While some literature suggests statins may improve plaque stability, reduce inflammation and thrombosis, decrease oxidative stress, and improve endothelial function and vascular tone, other studies have suggested potential harmful pleiotropic effects related to increased risk of muscle-related side effects, diabetes, hemorrhagic stroke, and cognitive decline. Furthermore, the introduction of newer, non-statin LDL-C lowering therapies, including ezetimibe, proprotein convertase subtilisin/Kexin Type 9, and bempedoic acid, have challenged the statin pleiotropy theory. This review aims to provide a historical background on the development of statins, explore the mechanistic underpinnings of statin pleiotropy, review the available literature, and provide up to date examples that suggest statins may exert effects outside of LDL-C lowering and the cardiovascular system.

Endothelial Function in Dyslipidemia: Roles of LDL-Cholesterol, HDL-Cholesterol and Triglycerides

Dyslipidemia is associated with endothelial dysfunction. Endothelial dysfunction is the initial step for atherosclerosis, resulting in cardiovascular complications. It is clinically important to break the process of endothelial dysfunction to cardiovascular complications in patients with dyslipidemia. Lipid-lowering therapy enables the improvement of endothelial function in patients with dyslipidemia. It is likely that the relationships of components of a lipid profile such as low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides with endothelial function are not simple. In this review, we focus on the roles of components of a lipid profile in endothelial function.

Anti-Inflammatory Effects of Lipid-Lowering Drugs and Supplements-A Narrative Review

Cardiovascular diseases (CVD) are the leading cause of death worldwide. Since the establishment of the "lipid hypothesis", according to which, cholesterol level is directly correlated to the risk of CVD, many different lipid-lowering agents have been introduced in clinical practice. A majority of these drugs, in addition to their lipid-lowering properties, may also exhibit some anti-inflammatory and immunomodulatory activities. This hypothesis was based on the observation that a decrease in lipid levels occurs along with a decrease in inflammation. Insufficient reduction in the inflammation during treatment with lipid-lowering drugs could be one of the explanations for treatment failure and recurrent CVD events. Thus, the aim of this narrative review was to evaluate the anti-inflammatory properties of currently available lipid-lowering medications including statins, ezetimibe, bile acid sequestrants (BAS), proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, fibrates, omega-3 fatty acids, and niacin, as well as dietary supplements and novel drugs used in modern times.

Effect of Atorvastatin on Microcirculation Evaluated by Vascular Occlusion Test with Peripheral Near-Infrared Spectroscopy

The vascular occlusion test (VOT) with peripheral near-infrared spectroscopy (NIRS) is a non-invasive method to evaluate peripheral microcirculation. Statin therapy is widely used for patients with dyslipidaemia and contributes to reducing low-density lipoprotein cholesterol (LDL-C) levels and adverse cardiovascular events. However, it is not yet clear whether statin treatment improves peripheral microcirculation assessed by VOT with NIRS. In the present study, using VOT with NIRS, we evaluated the effect of statin therapy on peripheral microcirculation in patients with dyslipidaemia before and after statin therapy.

METHODS

A total of six consecutive patients with dyslipidaemia who had not received statin therapy (6 males, mean age 71.8 ± 7.4 years) were enrolled. All patients were administered atorvastatin and their peripheral microcirculation assessed using VOT with NIRS (NIRO-200NX, Hamamatsu Photonics K.K., Japan) before and after statin therapy. The NIRS probe was attached to the right thenar eminence and brachial artery blood flow was blocked for 3 min at 50 mmHg above the resting systolic blood pressure. Maximum and minimum values of NIRS parameters after the VOT were used to determine concentration changes for total haemoglobin (ΔcHb), oxyhaemoglobin (ΔO2Hb), deoxyhaemoglobin (ΔHHb), and tissue oxygenation index (ΔTOI).

RESULTS

During the follow-up period (mean 30.3 ± 6.5 days), LDL-C level decreased from 129.7 ± 26.3 to 67.5 ± 20.2 mg/dL (p-value = 0.031), ΔTOI increased from 24.0 ± 5.3 to 33.7 ± 6.3% (p-value = 0.023), and ΔO2Hb increased from 16.4 ± 5.3 to 20.0 ± 6.6 μmol/L (p-value = 0.007). ΔcHb and ΔHHb did not change significantly.

CONCLUSION

ΔO2Hb and ΔTOI were significantly increased during the follow-up period. These findings suggest that ΔO2Hb and ΔTOI could assess the improvement of peripheral microcirculation by statin therapy. Compared to ΔTOI, ΔO2Hb seems to be a more useful parameter to evaluate peripheral microcirculation.

Rivaroxaban compared with low-dose aspirin in individuals with type 2 diabetes and high cardiovascular risk: a randomised trial to assess effects on endothelial function, platelet activation and vascular biomarkers

AIMS/HYPOTHESIS

Individuals with type 2 diabetes mellitus and subclinical inflammation have stimulated coagulation, activated platelets and endothelial dysfunction. Recent studies with the direct factor Xa inhibitor rivaroxaban in combination with low-dose aspirin demonstrated a significant reduction of major cardiovascular events, especially in individuals with type 2 diabetes and proven cardiovascular disease. Therefore, we asked the question of whether treatment with rivaroxaban could influence endothelial function, arterial stiffness and platelet activation.

METHODS

We conducted a multi-centre, prospective, randomised, open-label trial in 179 participants with type 2 diabetes (duration 2-20 years), subclinical inflammation (high-sensitivity C-reactive protein 2-10 mg/l) and at least two traits of the metabolic syndrome to compare the effects of the direct factor Xa inhibitor rivaroxaban (5 mg twice daily) vs aspirin (100 mg every day) on endothelial function (assessed by forearm occlusion plethysmography), skin blood flow (assessed by laser-Doppler fluxmetry), arterial stiffness (assessed by pulse wave velocity) and serum biomarkers of endothelial function and inflammation. Furthermore, we investigated phosphorylation of vasodilator-stimulated phosphoprotein (VASP) in platelets, the concentration of platelet-derived microparticles (PMPs) and the effects of isolated PMPs on HUVEC proliferation in vitro.

RESULTS

Rivaroxaban treatment for 20 weeks (n = 89) resulted in a significant improvement of post-ischaemic forearm blood flow (3.6 ± 4.7 vs 1.0 ± 5.2 ml/100 ml, p = 0.004), a numerically increased skin blood flow and reduced soluble P-Selectin plasma level vs aspirin. We did not find significant differences of arterial stiffness or further biomarkers. Neither rivaroxaban nor aspirin influenced VASP phosphorylation of platelets. The number of PMPs increased significantly with both rivaroxaban (365.2 ± 372.1 vs 237.4 ± 157.1 μl^-1, p = 0.005) and aspirin (266.0 ± 212.7 vs 201.7 ± 162.7 μl^-1, p = 0.021). PMPs of rivaroxaban-treated participants stimulated HUVEC proliferation in vitro compared with aspirin. Rivaroxaban was associated with a higher number of bleeding events.

CONCLUSIONS/INTERPRETATION

Our findings indicate that the direct factor Xa inhibitor rivaroxaban improved endothelial function in participants with type 2 diabetes and subclinical inflammation but also increased the risk of bleeding.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02164578.

FUNDING

The study was supported by a research grant from Bayer Vital AG, Germany.

Similar major cardiovascular outcomes between pure statin and ezetimibe-statin in comparable intensity for type 2 diabetes with extremely atherosclerotic risks

Atorvastatin 40 mg (ATOR 40) and ezetimibe 10 mg/simvastatin 20 mg (EZ-SIM 20) have similar reductions of low-density lipoprotein cholesterol (LDL-C) but cardiovascular (CV) outcomes between these two therapies are unclear. Our real-world cohort study is to test the hypothesis of pleiotropic effects of purely higher dose statin on CV outcomes beyond similar reductions of LDL-C, especially for extremely CV risk patients. Between January 1, 2007 and December 31, 2013, a total of 3,372 patients with type 2 diabetes mellitus (T2DM) admitted due to acute coronary syndrome (ACS) or acute ischemic stroke (AIS) were selected as the study cohort from the Taiwan National Health Insurance Research Database. Clinical outcomes were evaluated by ATOR 40 group (n = 1686) matched with EZ-SIM 20 group (n = 1686). Primary composite outcome includes CV death, non-fatal myocardial infarction, and non-fatal stroke. Secondary composite outcome includes hospitalization for unstable angina (HUA), percutaneous coronary intervention (PCI), and coronary artery bypass grafting (CABG). With a mean follow-up of 2.4 years, no significant difference of primary composite outcome was observed between ATOR 40 and EZ-SIM 20 groups (subdistribution hazard ratio [SHR], 1.09; 95% confidence interval [CI], 0.95–1.25). Nevertheless, ATOR 40 group had lower risks of HUA (SHR, 0.50; 95% CI, 0.35–0.72), PCI (SHR, 0.82; 95% CI, 0.69–0.97) and CABG (SHR, 0.62; 95% CI, 0.40–0.97) than EZ-SIM 20 group. For T2DM patients after ACS or AIS, ATOR 40 and EZ-SIM 20 had similar major CV outcomes, which still supported the main driver for CV risk reductions is LDL-C lowering.

Statins as a Medical Adjunct in the Surgical Management of Chronic Subdural Hematomas

BACKGROUND

By stabilizing immature leaky vessel formation in neomembranes, statin drugs have been suggested as a nonsurgical treatment option for chronic subdural hematomas (cSDH). Statin therapy seems to reduce conservatively managed cSDH volume. However, the usefulness of these medications in supplementing surgical treatment is unknown.

OBJECTIVE

To investigate the effect of concurrent statin therapy on outcomes after surgical treatment of cSDH.

METHODS

A retrospective single-institution cohort study of surgically managed patients with convexity cSDH between 2009 and 2019 was conducted. Patients receiving this diagnosis who underwent surgical decompression were included, and those without follow-up scans were excluded. Demographic, clinical, and radiographic variables were collected. cSDH size was defined as maximum radial thickness in millimeters on axial computed tomography of the head. Multivariable linear regression was performed to identify factors (including statin use) that were associated with preoperative to follow-up cSDH size change.

RESULTS

Overall, 111 patients, including 36 patients taking statins on admission, were evaluated. Median time to follow-up postoperative imaging was 30 days (interquartile range, 17-42 days). Patients on statins were older (median, 75 years, range, 68-78.25 years vs. 69 years, range, 59-7 years; P = 0.006) and reported more antiplatelet use (67% vs. 28%; P < 0.001). Median change in follow-up size was 13 mm in both statin and nonstatin groups. Adjusting for other clinical covariates, statin use was associated with greater reduction in cSDH size (CE = -6.72 mm, 95% confidence interval, -13.18 to -0.26 mm; P = 0.042).

CONCLUSIONS

Statin use is associated with improved cSDH size postoperatively. Statin drugs might represent a low-cost and low-risk supplement to the surgical management for patients with cSDH.

Atorvastatin pleiotropically decreases intraplaque angiogenesis and intraplaque haemorrhage by inhibiting ANGPT2 release and VE-Cadherin internalization

OBJECTIVE

Statins pleiotropically provide additional benefits in reducing atherosclerosis, but their effects on intraplaque angiogenesis (IPA) and hemorrhage (IPH) remain unclear. Therefore, we discriminated statin's lipid-lowering dependent and independent effects on IPA and IPH.

APPROACH AND RESULTS

ApoE3*Leiden mice are statin-responsive due to ApoE and LDLR presence, but also allow to titrate plasma cholesterol levels by diet. Therefore, ApoE3*Leiden mice were fed a high-cholesterol-inducing-diet (HCD) with or without atorvastatin (A) or a moderate-cholesterol-inducing-diet (MCD). Mice underwent vein graft surgery to induce lesions with IPA and IPH. Cholesterol levels were significantly reduced in MCD (56%) and HCD + A (39%) compared to HCD with no significant differences between MCD and HCD + A. Both MCD and HCD + A have a similar reduction in vessel remodeling and inflammation comparing to HCD. IPA was significantly decreased by 30% in HCD + A compared to HCD or MCD. Atorvastatin treatment reduced the presence of immature vessels by 34% vs. HCD and by 25% vs. MCD, resulting in a significant reduction of IPH. Atorvastatin's anti-angiogenic capacity was further illustrated by a dose-dependent reduction of ECs proliferation and migration. Cultured mouse aortic-segments lost sprouting capacity upon atorvastatin treatment and became 30% richer in VE-Cadherin expression and pericyte coverage. Moreover, Atorvastatin inhibited ANGPT2 release and decreased VE-Cadherin(Y685)-phosphorylation in ECs.

CONCLUSIONS

Atorvastatin has beneficial effects on vessel remodeling due to its lipid-lowering capacity. Atorvastatin has strong pleiotropic effects on IPA by decreasing the number of neovessels and on IPH by increasing vessel maturation. Atorvastatin improves vessel maturation by inhibiting ANGPT2 release and phospho(Y658)-mediated VE-Cadherin internalization.

Coronary and peripheral artery plaques: do differences in plaque characteristics translate to differences in lipid management?

Optimal medical management of patients with peripheral arterial disease (PAD) includes statin therapy, which has been shown to decrease the risk of major cardiovascular events. However, the relationship between low-density lipoprotein (LDL) lowering, PAD progression and limb outcomes remains controversial. Although prevention of coronary and cerebrovascular events is a priority, limb outcomes are still important determinants of quality of life and healthcare spending. This review will highlight differences between coronary artery disease (CAD) and PAD, and in particular, the more prevalent role of lipids and LDL cholesterol in CAD versus calcification in PAD. This difference may contribute to the differential impact of LDL cholesterol levels on coronary events and outcomes versus limb outcomes. Beyond LDL lowering, immune modulators have emerged as another agent to treat atherosclerosis in CAD, however similar data in PAD are lacking. Small studies have suggested that other lipids besides LDL cholesterol, such as triglycerides or small dense LDL, may have a greater impact on limb outcomes in patients with PAD. Although statin therapy is central in the management of patients with PAD, current understanding of the distinctions between PAD and CAD suggest that there may be other non-LDL targets for risk reduction that require further study.

The Pleiotropic Effects of Statins - From Coronary Artery Disease and Stroke to Atrial Fibrillation and Ventricular Tachyarrhythmia

Statins, 3-hydroxy-methylglutaryl coenzyme A reductase inhibitors, have been used for decades for the prevention of coronary artery disease and stroke. They act primarily by lowering serum cholesterol through the inhibition of cholesterol synthesis in the liver, which results in the upregulation of low-density lipoprotein receptors in the liver. This results in the removal of low-density lipoproteincholesterol. Studies have suggested that statins may demonstrate additional effects that are independent of their effects on low-density lipoprotein-cholesterol. These have been termed "pleiotropic" effects. Pleiotropic effects may be due to the inhibition of isoprenoid intermediates by statins. Isoprenoid inhibition has effects on the small guanosine triphosphate binding proteins Rac and Rho which in turn effects nicotinamide adenine dinucleotide phosphate oxidases. Therefore, there are changes in endothelial nitric oxide synthase expression, atherosclerotic plaque stability, pro-inflammatory cytokines and reactive oxygen species production, platelet reactivity, and cardiac fibrosis and hypetrophy development. Recently, statins have been compared to the ezetimibe and the recently published outcomes data on the proprotein convertase subtilisin kexin type 9 inhibitors has allowed for a reexamination of statin pleiotropy. As a result of these diverse effects, it has been suggested that statins also have anti-arrhythmic effects. This review focuses on the mechanisms of statin pleiotropy and discusses evidence from the statin clinical trials as well as examining the possible anti-arrhythmic effects atrial fibrillation and ventricular tachyarrhythmias.

Role of endothelial dysfunction in determining angina after percutaneous coronary intervention: Learning from pathophysiology to optimize treatment

Endothelial dysfunction (EnD) is a hallmark feature of coronary artery disease (CAD), representing the key early step of atherosclerotic plaque development and progression. Percutaneous coronary intervention (PCI) is performed daily worldwide to treat symptomatic CAD, however a consistent proportion of patients remain symptomatic for angina despite otherwise successful revascularization. EnD plays a central role in the mechanisms of post-PCI angina, as it is strictly associated with both structural and functional abnormalities in the coronary arteries that may persist, or even accentuate, following PCI. The assessment of endothelial function in patients undergoing PCI might help to identify those patients at higher risk of future cardiovascular events and recurrent/persistent angina who might therefore benefit more from an intensive treatment. In this review, we address the role of EnD in determining angina after PCI, discussing its pathophysiological mechanisms, diagnostic approaches and therapeutic perspectives.

Atorvastatin upregulates apolipoprotein M expression via attenuating LXRα expression in hyperlipidemic apoE-deficient mice

Apolipoprotein M (apoM) is a recently identified human apolipoprotein that is associated with the formation of high-density lipoprotein (HDL). Studies have demonstrated that statins may affect the expression of apoM; however, the regulatory effects of statins on apoM are controversial. Furthermore, the underlying mechanisms by which statins regulate apoM remain unclear. In the present study, in vivo and in vitro models were used to investigate whether the anti-atherosclerotic effects of statins are associated with its apoM-regulating effects and the underlying mechanism. Hyperlipidemia was induced by in apolipoprotein E-deficient mice by providing a high-fat diet. Atorvastatin was administered to hyperlipidemic mice and HepG2 cells to investigate its effect on apoM expression. The liver X receptor α (LXRα) agonist T0901317 was also administered together with atorvastatin to hyperlipidemic mice and HepG2 cells. The results revealed that atorvastatin increased apoM expression, which was accompanied with decreased expression of LXRα in the liver of hyperlipidemic apolipoprotein E-deficient mice and HepG2 cells. Additionally, apoM upregulation was inhibited following treatment with T0901317. In summary, atorvastatin exhibited anti-atherosclerotic effects by upregulating apoM expression in hyperlipidemic mice, which may be mediated by the inhibition of LXRα.

Lipid lowering drugs and inflammatory changes: an impact on cardiovascular outcomes?

Inflammatory changes are responsible for maintenance of the atherosclerotic process and may underlie some of the most feared vascular complications. Among the multiple mechanisms of inflammation, the arterial deposition of lipids and particularly of cholesterol crystals is the one responsible for the activation of inflammasome NLRP3, followed by the rise of circulating markers, mainly C-reactive protein (CRP). Elevation of lipoproteins, LDL but also VLDL and remnants, associates with increased inflammatory changes and coronary risk. Lipid lowering medications can reduce cholesterolemia and CRP: patients with elevations of both are at greatest cardiovascular (CV) risk and receive maximum benefit from therapy. Evaluation of the major drug series indicates that statins exert the largest LDL and CRP reduction, accompanied by reduced CV events. Other drugs, mainly active on the triglyceride/HDL axis, for example, PPAR agonists, may improve CRP and the lipid pattern, especially in patients with metabolic syndrome. PCSK9 antagonists, the newest most potent medications, do not induce significant changes in inflammatory markers, but patients with the highest baseline CRP levels show the best CV risk reduction. Parallel evaluation of lipids and inflammatory changes clearly indicates a significant link, both guiding to patients at highest risk, and to the best pharmacological approach. Key messages Lipid lowering agents with "pleiotropic" effects provide a more effective approach to CV prevention In CANTOS study, patients achieving on-treatment hsCRP concentrations ≤2 mg/L had a higher benefit in terms of reduction in major CV events The anti-inflammatory activity of PCSK9 antagonists appears to be of a minimal extent.

Statin Effects on Metabolic Profiles: Data From the PREVEND IT (Prevention of Renal and Vascular End-stage Disease Intervention Trial)

BACKGROUND

Statins lower cholesterol by inhibiting HMG-CoA reductase, the rate-limiting enzyme of the metabolic pathway that produces cholesterol and other isoprenoids. Little is known about their effects on metabolite and lipoprotein subclass profiles. We, therefore, investigated the molecular changes associated with pravastatin treatment compared with placebo administration using a nuclear magnetic resonance-based metabolomics platform.

METHODS AND RESULTS

We performed metabolic profiling of 231 lipoprotein and metabolite measures in the PREVEND IT (Prevention of Renal and Vascular End-stage Disease Intervention Trial) study, a placebo-controlled randomized clinical trial designed to test the effects of pravastatin (40 mg once daily) on cardiovascular risk. Metabolic profiles were assessed at baseline and after 3 months of treatment. Pravastatin lowered low-density lipoprotein cholesterol (change in SD units [95% confidence interval]: -1.01 [-1.14, -0.88]), remnant cholesterol (change in SD units [95% confidence interval]: -1.03 [-1.17, -0.89]), and apolipoprotein B (change in SD units [95% confidence interval]: -0.98 [-1.11, -0.86]) with similar effect magnitudes. In addition, pravastatin globally lowered levels of lipoprotein subclasses, with the exception of high-density lipoprotein subclasses, which displayed a more heterogeneous response pattern. The lipid-lowering effect of pravastatin was accompanied by selective changes in lipid composition, particularly in the cholesterol content of very-low-density lipoproteinparticles. In addition, pravastatin reduced levels of several fatty acids but had limited effects on fatty acid ratios.

CONCLUSIONS

These randomized clinical trial data demonstrate the widespread effects of pravastatin treatment on lipoprotein subclass profiles and fatty acids.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT03073018.

Vascular inflammation and low-density lipoproteins: is cholesterol the link? A lesson from the clinical trials

For long time, the role of LDL and inflammation in the pathogenesis of atherosclerosis have been studied independently from each other and only more recently a common platform has been suggested. Accumulation of excess cholesterol due to the presence of increased circulating LDL promotes endothelium dysfunction and activation, which is associated with increased production of pro-inflammatory cytokines, overexpression of adhesion molecules, chemokines and C-reactive protein (CRP), increased generation of reactive oxygen species and reduction of nitric oxide levels and bioavailability. All these processes favour the progressive infiltration of inflammatory cells within the arterial wall where cholesterol accumulates, both extracellularly and intracellularly, and promotes vascular inflammation. According to this, lipid-lowering therapies should improve inflammation and, indeed, statins decrease circulating inflammatory markers such as CRP and improve endothelial function and plaque burden. Pleiotropic activities have been proposed to explain this effect. However, mendelian randomization studies ruled out a direct role for CRP on coronary artery disease and studies with other lipid lowering drugs, such as ezetimibe showed that the beneficial effect of LDL-cholesterol-lowering therapies on systemic inflammatory status, as monitored by changes in CRP plasma levels, could be achieved, independently of the mechanism of action, only in patients presenting with baseline inflamed conditions. These observations strengthen the direct link between cholesterol and inflammation and indicate that decreasing LDL levels is one of the key goals for improving cardiovascular outcome.

LINKED ARTICLES

This article is part of a themed section on Targeting Inflammation to Reduce Cardiovascular Disease Risk. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.22/issuetoc and http://onlinelibrary.wiley.com/doi/10.1111/bcp.v82.4/issuetoc.

Optimal Target Level of Low-density Lipoprotein Cholesterol for Vascular Function in Statin Naïve Individuals

We investigated (1) the relationship between low-density lipoprotein cholesterol (LDL-C) and vascular function in patients receiving and those not receiving statin therapy and (2) optimal level of LDL-C for maintenance of vascular function. Flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation (NID) were inversely correlated with LDL-C in the 957 statin naïve subjects but not in the 392 subjects receiving statin therapy. In statin naïve subjects, non-high LDL-C (≤100 mg/dL) was independently associated with a decrease in adjusted odds ratio of the low tertile of FMD (OR: 0.62, 95% CI: 0.45–0.85; P = 0.003) and NID (OR: 0.69, 95% CI: 0.50–0.96; P = 0.03). Adjusted odds ratio of the low tertile of FMD was significantly lower in the low LDL-C group (≤70 mg/dL) (OR: 0.47, 95% CI, 0.27–0.81; P = 0.006) and in the moderate LDL-C group (70.1–100 mg/dL) (OR: 0.66, 95% CI, 0.48–0.94; P = 0.02) than in the high LDL-C group (>100 mg/dL). There was no significant difference in FMD between the low LDL-C group and moderate LDL-C group. There were significant relationships of FMD and NID with LDL-C levels in statin naïve subjects. In a general population, LDL-C of ≤100 mg/dL may be the optimal target level for maintenance of endothelial function.

Pleiotropic Effects of Statins on the Cardiovascular System

The statins have been used for 30 years to prevent coronary artery disease and stroke. Their primary mechanism of action is the lowering of serum cholesterol through inhibiting hepatic cholesterol biosynthesis thereby upregulating the hepatic low-density lipoprotein (LDL) receptors and increasing the clearance of LDL-cholesterol. Statins may exert cardiovascular protective effects that are independent of LDL-cholesterol lowering called pleiotropic effects. Because statins inhibit the production of isoprenoid intermediates in the cholesterol biosynthetic pathway, the post-translational prenylation of small GTP-binding proteins such as Rho and Rac, and their downstream effectors such as Rho kinase and nicotinamide adenine dinucleotide phosphate oxidases are also inhibited. In cell culture and animal studies, these effects alter the expression of endothelial nitric oxide synthase, the stability of atherosclerotic plaques, the production of proinflammatory cytokines and reactive oxygen species, the reactivity of platelets, and the development of cardiac hypertrophy and fibrosis. The relative contributions of statin pleiotropy to clinical outcomes, however, remain a matter of debate and are hard to quantify because the degree of isoprenoid inhibition by statins correlates to some extent with the amount of LDL-cholesterol reduction. This review examines some of the currently proposed molecular mechanisms for statin pleiotropy and discusses whether they could have any clinical relevance in cardiovascular disease.

Endothelial dysfunction and vascular disease - a 30th anniversary update

The endothelium can evoke relaxations of the underlying vascular smooth muscle, by releasing vasodilator substances. The best-characterized endothelium-derived relaxing factor (EDRF) is nitric oxide (NO) which activates soluble guanylyl cyclase in the vascular smooth muscle cells, with the production of cyclic guanosine monophosphate (cGMP) initiating relaxation. The endothelial cells also evoke hyperpolarization of the cell membrane of vascular smooth muscle (endothelium-dependent hyperpolarizations, EDH-mediated responses). As regards the latter, hydrogen peroxide (H₂ O₂ ) now appears to play a dominant role. Endothelium-dependent relaxations involve both pertussis toxin-sensitive G_i (e.g. responses to α₂ -adrenergic agonists, serotonin, and thrombin) and pertussis toxin-insensitive G_q (e.g. adenosine diphosphate and bradykinin) coupling proteins. New stimulators (e.g. insulin, adiponectin) of the release of EDRFs have emerged. In recent years, evidence has also accumulated, confirming that the release of NO by the endothelial cell can chronically be upregulated (e.g. by oestrogens, exercise and dietary factors) and downregulated (e.g. oxidative stress, smoking, pollution and oxidized low-density lipoproteins) and that it is reduced with ageing and in the course of vascular disease (e.g. diabetes and hypertension). Arteries covered with regenerated endothelium (e.g. following angioplasty) selectively lose the pertussis toxin-sensitive pathway for NO release which favours vasospasm, thrombosis, penetration of macrophages, cellular growth and the inflammatory reaction leading to atherosclerosis. In addition to the release of NO (and EDH, in particular those due to H₂ O₂ ), endothelial cells also can evoke contraction of the underlying vascular smooth muscle cells by releasing endothelium-derived contracting factors. Recent evidence confirms that most endothelium-dependent acute increases in contractile force are due to the formation of vasoconstrictor prostanoids (endoperoxides and prostacyclin) which activate TP receptors of the vascular smooth muscle cells and that prostacyclin plays a key role in such responses. Endothelium-dependent contractions are exacerbated when the production of nitric oxide is impaired (e.g. by oxidative stress, ageing, spontaneous hypertension and diabetes). They contribute to the blunting of endothelium-dependent vasodilatations in aged subjects and essential hypertensive and diabetic patients. In addition, recent data confirm that the release of endothelin-1 can contribute to endothelial dysfunction and that the peptide appears to be an important contributor to vascular dysfunction. Finally, it has become clear that nitric oxide itself, under certain conditions (e.g. hypoxia), can cause biased activation of soluble guanylyl cyclase leading to the production of cyclic inosine monophosphate (cIMP) rather than cGMP and hence causes contraction rather than relaxation of the underlying vascular smooth muscle.

Perioperative Statin Treatment: Can it Decrease Postsurgical Cardiac Event Risk in Noncardiac Surgery?

Cardiac events are an important cause of postsurgical morbidity and mortality. Statin drugs have been studied as potentially risk-modifying agents in perioperative medicine. They have been shown to confer a protective benefit in cardiac surgery, but the evidence available in noncardiac surgery patient populations remains less conclusive. We hypothesized that perioperative statin treatment would be associated with lower incidence of postsurgical cardiac events (PSCEs) after major noncardiac surgery. A retrospective cohort study included 21,637 major noncardiac surgeries. Statin treatment was the exposure of interest and PSCE was the primary outcome measure. Data collection included patient age, body mass index, smoking status, diabetic status, cardiac event history, statin treatment history, and PSCE diagnoses. Perioperative statin treatment occurred in 4176 cases (19.3%). PSCEs occurred in 50 cases (0.23%), 29 in the untreated control group (0.17%) and 21 in the statin treatment group (0.50%). Relative risk in the untreated group was 0.3303 (95% confidence interval = 0.1886, 0.5786). This implied that statin-treated patients had higher risk than the untreated group. However, a logistic regression model that accounted for observed cardiac disease risk factors showed statin treatment not to be a significant predictor of PSCE in this sample. Analysis repeated in high-risk subsets of the cohort yielded similar results. A propensity score matching method that minimized differences between study groups also failed to demonstrate a significant association between statin treatment and PSCE risk. Our study did not demonstrate a significant association between perioperative statin treatment and PSCEs after major noncardiac surgery.

SmgGDS as a Crucial Mediator of the Inhibitory Effects of Statins on Cardiac Hypertrophy and Fibrosis: Novel Mechanism of the Pleiotropic Effects of Statins

The detailed molecular mechanisms of the pleiotropic effects of statins remain to be fully elucidated. Here, we hypothesized that cardioprotective effects of statins are mediated by small GTP-binding protein GDP dissociation stimulator (SmgGDS). SmgGDS(+/-) and wild-type (WT) mice were treated with continuous infusion of angiotensin II (Ang II) for 2 weeks with and without oral treatment with atorvastatin or pravastatin. At 2 weeks, the extents of Ang II-induced cardiac hypertrophy and fibrosis were comparable between the 2 genotypes. However, statins significantly attenuated cardiomyocyte hypertrophy and fibrosis in WT mice, but not in SmgGDS(+/-) mice. In SmgGDS(+/-) cardiac fibroblasts (CFs), Rac1 expression, extracellular signal-regulated kinases 1/2 activity, Rho-kinase activity, and inflammatory cytokines secretion in response to Ang II were significantly increased when compared with WT CFs. Atorvastatin significantly reduced Rac1 expression and oxidative stress in WT CFs, but not in SmgGDS(+/-) CFs. Furthermore, Bio-plex analysis revealed significant upregulations of inflammatory cytokines/chemokines and growth factors in SmgGDS(+/-) CFs when compared with WT CFs. Importantly, conditioned medium from SmgGDS(+/-) CFs increased B-type natriuretic peptide expression in rat cardiomyocytes to a greater extent than that from WT CFs. Furthermore, atorvastatin significantly increased SmgGDS secretion from mouse CFs. Finally, treatment with recombinant SmgGDS significantly reduced Rac1 expression in SmgGDS(+/-) CFs. These results indicate that both intracellular and extracellular SmgGDS play crucial roles in the inhibitory effects of statins on cardiac hypertrophy and fibrosis, partly through inhibition of Rac1, Rho kinase, and extracellular signal-regulated kinase 1/2 pathways, demonstrating the novel mechanism of the pleiotropic effects of statins.

Pleiotropic effects of statins

Statins or 3-hydroxy-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors not only prevents the synthesis of cholesterol biosynthesis but also inhibits the synthesis of essential isoprenoid intermediates such as farnesyl pyrophosphate, geranylgeranyl pyrophosphate, isopentanyl adenosine, dolichols and polyisoprenoid side chains of ubiquinone, heme A, and nuclear lamins. These isoprenoid intermediates are required for activation of various intracellular/signaling proteins- small guanosine triphosphate bound protein Ras and Ras-like proteins like Rho, Rab, Rac, Ral, or Rap which plays an indispensible role in multiple cellular processes. Reduction of circulating isoprenoids intermediates as a result of HMG CoA reductase inhibition by statins prevents activation of these signalling proteins. Hence, the multiple effects of statins such as antiinflammatory effects, antioxidant effects, antiproliferative and immunomodulatory effects, plaque stability, normalization of sympathetic outflow, and prevention of platelet aggregation are due to reduction of circulating isoprenoids and hence inactivation of signalling proteins. These multiple lipid-independent effects of statins termed as statin pleiotropy would potentially open floodgates for research in multiple treatment domains catching attentions of researchers and clinician across the globe.

Cellular and molecular mechanisms of statins: an update on pleiotropic effects

Coronary artery disease (CAD) is the leading cause of death worldwide. The efficacy and safety of statins (3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors) in primary and secondary prevention of CAD are confirmed in several large studies. It is well known that statins have some pleiotropic, anti-atherosclerotic effects. We review the molecular mechanisms underlying the beneficial effects of statins revealed in recently published studies. Endothelial cell injury is regarded as the classic stimulus for the development of atherosclerotic lesions. In addition, the inflammatory process plays an important role in the aetiology of atherosclerosis. In particular, chronic inflammation plays a key role in coronary artery plaque instability and subsequent occlusive thrombosis. Our previous reports and others have demonstrated beneficial effects of statins on endothelial dysfunction and chronic inflammation in CAD. A better understanding of the molecular mechanism underlying the effectiveness of statins against atherosclerosis may provide a novel therapeutic agent for the treatment of coronary atherosclerosis. The present review summarizes the cellular and molecular mechanism of statins against coronary atherosclerosis.

A pilot study of ezetimibe vs. atorvastatin for improving peripheral microvascular endothelial function in stable patients with type 2 diabetes mellitus

BACKGROUND

Elevated cholesterol in type 2 diabetes mellitus (DM) can cause endothelial dysfunction. An effective clinical therapy to improve endothelial dysfunction remains to be established. Different cardiovascular actions between treatments for the inhibition of cholesterol absorption and the suppression of cholesterol synthesis for achieving improvement in endothelial function are unknown in DM.

METHODS

Stable patients with type 2 DM and mildly elevated low-density lipoprotein cholesterol were enrolled. We evaluated peripheral microvascular endothelial function using reactive hyperemia peripheral arterial tonometry (RH-PAT) examination and calculated a natural logarithmic transformed value for the RH-PAT index (LnRHI). We randomly assigned 33 patients to each monotherapy: cholesterol synthesis suppression using atorvastatin (5 mg/day, n=16) or cholesterol absorption inhibition using ezetimibe (10 mg/day, n=17). Patients were prospectively followed for 6 months. Serum lipids and LnRHI were repeatedly examined before and after each therapy.

RESULTS

LDL significantly decreased in both groups, but the percent changes of LDL showed a greater decrease in the atorvastatin group compared with the ezetimibe group (-34.5±7.8% vs. -21.9±9.6%, p<0.01). Serum levels of non-esterified free fatty acids (NEFA) significantly decreased in the ezetimibe group but not in the atorvastatin group (ezetimibe group: 561.1±236.8 to 429.7±195.9, p<0.01; atorvastatin group: 538.8±319.5 to 520.2±227.3, p=0.75). The percent decrease in NEFA was significantly greater in the ezetimibe group compared with the atorvastatin group (-19.9±27.4% vs. 11.3±44.1%, p<0.05). LnRHI showed a significant increase in the ezetimibe group but not in the atorvastatin group (ezetimibe group: 0.471±0.157 to 0.678±0.187, p<0.01; atorvastatin group: 0.552±0.084 to 0.558±0.202, p=0.64). The percent changes in LnRHI were significantly greater in the ezetimibe group compared with the atorvastatin group (63.3±89.2% vs. 7.4±41.2%, p<0.05).

CONCLUSIONS

In patients with type 2 DM, ezetimibe monotherapy significantly reduced LDL and NEFA, and improved peripheral microvascular endothelial dysfunction. Ezetimibe could potentially exhibit beneficial effects on lipid disorders and microvascular endothelial dysfunction in DM.

Impact of smoking on coronary microcirculatory resistance in patients with coronary artery disease

The aim of this study was to investigate the relationship between coronary microvascular function and smoking using the 3 parameters fractional flow reserve (FFR), coronary flow reserve (CFR(thermo)), and index of microcirculatory resistance (IMR) in patients with coronary artery disease (CAD). A total of 97 CAD patients with 148 intermediate stenotic lesions were divided into two groups: current and former smokers (Smokers: n = 54), and those who had never smoked (Non-smokers: n = 43). Coronary physiology measurements were made following coronary angiography at rest and during hyperemia induced with intravenous adenosine triphosphate. If a patient had several intermediate lesions, the lesion producing the largest IMR value and minimum FFR(myo) and CFR(thermo) value was selected. Averaged over all patients, the FFR(myo), CFR(thermo), and IMR values were 0.86 ± 0.10, 2.66 ± 1.50, and 20.8 ± 10.7, respectively. There was no significant correlation between FFR(myo) and IMR. There were no significant differences between smokers and non-smokers in FFR(myo) value (median: 0.85 [IQR: 0.74-0.90] versus 0.87 [IQR: 0.83-0.90], P = 0.15) and CFR(thermo) value (median: 1.90 [IQR: 1.56-3.16] versus 2.10 [IQR: 1.50-2.67] U, P = 0.95). The IMR value was significantly greater in smokers (median: 24.2 [IQR: 16.8-32.5] U versus 18.5 [IQR: 15.4-27.0] U, P = 0.04). In multivariate analysis, smoking was an independent predictor of increased IMR. Smoking appears to have a detrimental effect on coronary microvascular function as measured by IMR.

Short-term statin discontinuation increases endothelial progenitor cells without inflammatory rebound in type 2 diabetic patients

Type 2 diabetes (T2D) is characterized by impaired vascular regeneration owing to reduced endothelial progenitor cells (EPCs). While statins are known to increase EPCs, the effects of statin withdrawal on EPCs are unknown. Herein, we evaluated the effects of statin discontinuation on EPCs, inflammation and in vivo angiogenesis. Thirty-four T2D patients were randomized to 5-day discontinuation or continuation of statin treatment. At baseline and at day 5, we determined lipid profile, EPC levels, monocyte-macrophage polarization, and concentrations of hsCRP, VEGF, SDF-1α, and G-CSF. Angiogenesis by human circulating cells was assessed in vivo. At day 5, patients who stopped statins showed raised total and LDL cholesterol and EPCs compared to baseline, while no changes were observed in patients who continued statins. No changes were observed in hsCRP, VEGF, SDF-1α, G-CSF, M1 and M2 macrophages and classical, intermediate and nonclassical monocytes in both groups. In vivo angiogenesis by circulating cells was increased in patients who stopped statin treatment. In vitro, cholesterol supplementation stimulated mobilizing signals in human bone marrow mesenchymal stem cells. In conclusion, a brief statin withdrawal increases circulating EPCs and functional proangiogenic cells in T2D. These findings identify statin-sensitive pathways as reverse target mechanisms to stimulate vascular repair in diabetes.

Influence of previous statin therapy on cholesterol-lowering effect of ezetimibe

BACKGROUND AND OBJECTIVES

The inhibition of cholesterol absorption by ezetimibe increases cholesterol synthesis. The effect of inhibition of cholesterol synthesis on cholesterol absorption is controversial. The influence of these interactions on cholesterol levels is unknown. We investigated on the extent to which cholesterol levels were affected by the reaction of one pathway to the inhibition of the other pathway.

SUBJECTS AND METHODS

This case-controlled study enrolled 198 patients who needed cholesterol-lowering drugs. Ezetimibe (10 mg) was administered to the patients with (n=58) and without on-going statin therapy (n=58). Simvastatin (20 mg) was administered to the patients treated with (n=41) and without ezetimibe (n=41).

RESULTS

Ezetimibe without statin lowered the total cholesterol by 13.3±8.8% (p<0.001) and the low density lipoprotein-cholesterol (LDL-C) by 18.7±15.3% (p<0.001). Ezetimibe added to statin decreased the total cholesterol by 21.1±7.7% (p<0.001) and the LDL-C by 29.9±12.6% (p<0.001). The total cholesterol and LDL-C were reduced more by ezetimibe in patients with statin therapy than in those without statin therapy (p<0.001 and p<0.001, respectively). The differences in the effect of simvastatin on total cholesterol and LDL-C between the patients with and without ezetimibe showed borderline significance (p=0.10 and p=0.055, respectively).

CONCLUSION

A prior inhibition of cholesterol synthesis by statin enhanced the effect of ezetimibe on total cholesterol and LDL-C by 7.8% and 11.2%, respectively. This finding suggests that ezetimibe increased cholesterol synthesis, resulting in a significant elevation of cholesterol levels.

Rationale and design of a randomized clinical study to investigate the effect of ezetimibe, a cholesterol absorption inhibitor, on the regression of intracoronary plaque evaluated by non-obstructive angioscopy and ultrasound: The ZIPANGU study

BACKGROUND AND PURPOSE

It is well recognized that low-density lipoprotein cholesterol (LDL-C)-lowering therapy is effective for primary and secondary prevention of cerebrovascular/cardiovascular disease. Ezetimibe, an inhibitor of the Niemann-Pick C1-Like 1 cholesterol transporter, is a relatively new drug for LDL-C-lowering therapy in addition to statins. However, comparison between an aggressive LDL-C-lowering therapy with a combination of statin and ezetimibe versus a standard LDL-C-lowering therapy with statin alone is still unclear in terms of their effects on stabilization and volume regression of coronary plaque. The ZIPANGU (Ezetimibe clinical investigation for the regression of intracoronary plaque evaluated by angioscopy and ultrasound) study is aimed at comparing these two types of therapy based on indices of plaque characteristics using non-obstructive coronary angioscopy and intravascular ultrasound.

METHODS

The study is a multi-center, prospective, randomized, open-label, blinded-endpoint trial. Through a centralized enrollment method, patients will be allocated to either monotherapy with atorvastatin alone or to combination therapy with atorvastatin (maximum: 20mg/day) and ezetimibe (10mg/day). The target LDL-C level will be <100mg/dL for the monotherapy group and <70mg/dL for the combination therapy group. At the baseline and the follow-up period of 9 months, non-obstructive coronary angioscopy and intravascular ultrasound will be performed to compare the changes in plaque color and volume between the two groups.

CONCLUSIONS

The ZIPANGU study will clarify whether combination therapy with statins and ezetimibe is better for stabilizing coronary plaque as secondary prevention than monotherapy by statins alone. The study will give new insights into lipid-lowering guidelines in Japan.

High-potency statin and ezetimibe use and mortality in survivors of an acute myocardial infarction: a population-based study

OBJECTIVE

To determine all-cause mortality in patients with a first myocardial infarct who were treated with simvastatin compared with high-potency statin and simvastatin/ezetimibe combination.

BACKGROUND

Despite statin use, residual cardiovascular risk remains. Therapeutic options include more potent statins or addition of ezetimibe. There is no clinical outcome data on the use of ezetimibe in such patients.

METHODS

Retrospective longitudinal study using the United Kingdom General Practice Research Database. Patients who had survived 30 days after their first acute myocardial infarct (AMI), had not received prior statin or ezetimibe therapy and were started on a statin within 30 days of AMI were included. Three groups were identified according to their follow-up: (i) simvastatin monotherapy; (ii) high-potency statin group (patients who started on simvastatin and switched to atorvastatin or rosuvastatin); and (iii) ezetimibe/statin combination group (patients who received ezetimibe in addition to statin).

RESULTS

9597 patients (57% male, mean age of 65 ± 13 years) matched study criteria: simvastatin (n=6990 (72.8%)); high-potency statin (n=1883, (19.6%)); and ezetimibe/statin combination (n=724 (7.5%)). During a mean follow-up of 3.2 years, there were 1134 (12%) deaths. In the multivariate proportional hazards model, the adjusted HR for high-potency statin and ezetimibe group were 0.72 (95% CI 0.59 to 0.88, p<0.001) and 0.96 (95% CI 0.64 to 1.43, p=0.85), respectively. A similar result was also obtained in the propensity score analysis that took into account covariates that predicted drug treatment groups.

CONCLUSIONS

Patients switched to a high-potency statin had a significantly reduced mortality compared with simvastatin monotherapy. There was no observed mortality benefit in the ezetimibe group.

High-dose statin monotherapy versus low-dose statin/ezetimibe combination on fasting and postprandial lipids and endothelial function in obese patients with the metabolic syndrome: The PANACEA study

BACKGROUND

Low-dose statin therapy in combination with ezetimibe, an inhibitor of intestinal cholesterol absorption, lowers plasma LDL-cholesterol levels to a similar degree as high-dose statin monotherapy. This study assessed whether similar LDL-cholesterol lowering with simvastatin/ezetimibe combination therapy improves fasting and postprandial arterial endothelial function compared to high-dose statin therapy alone.

METHODS

Multicenter, double-blind, crossover trial in 100 abdominally obese patients with the metabolic syndrome, randomized to 6 weeks' treatment with simvastatin 80 mg or simvastatin/ezetimibe 10/10 mg. Flow mediated dilatation (FMD) and peripheral arterial tonometry (EndoPAT) as well as plasma lipids were measured in the fasting state and after an oral lipid load at baseline and after both treatments.

RESULTS

Fasting LDL-cholesterol levels (3.57 mmol/L at baseline) were reduced to 1.79 mmol/L following treatment with simvastatin 80 mg and 1.81 mmol/L with simvastatin/ezetimibe 10/10 mg, respectively. Plasma lipids were similar at 4 h after an oral lipid load following both treatments for 6 weeks. Fasting endothelial function was also similar with both treatments when assessed by FMD (adjusted mean ± SE: 4.35 ± 0.19 vs. 4.43 ± 0.18; P = 0.777) and EndoPAT (2.12 ± 0.05 vs 2.20 ± 0.05; P = 0.304). After an oral fat load, changes in endothelial function were also comparable for both treatments as assessed by FMD (-0.34 ± 0.21 vs. -0.43 ± 0.20; P = 0.766) and EndoPAT (0.00 ± 0.07 vs. -0.04 ± 0.08; P = 0.712).

CONCLUSION

Treatment with simvastatin/ezetimibe 10/10 mg induced no difference in endothelial function in the fasting and postprandial state compared to simvastatin 80 mg while attaining similar LDL-c levels in obese patients with metabolic syndrome.

The effects of daily consumption of grapefruit on body weight, lipids, and blood pressure in healthy, overweight adults

Folklore has suggested that consuming grapefruit may promote weight control. Sparse data exist to support this hypothesis, although there is some evidence of health promotion effects with regard to blood pressure control and modulation of circulating lipids. The aim of this randomized controlled trial was to prospectively evaluate the role of grapefruit in reducing body weight and blood pressure and in promoting improvements in the lipid profile in overweight adults (N = 74). Following a 3-week washout diet low in bioactive-rich fruits and vegetables, participants were randomized to either the control diet (n = 32) or daily grapefruit (n = 42) in the amount of one half of a fresh Rio-Red grapefruit with each meal (3× daily) for 6 weeks. No differences between group in weight, blood pressure, or lipids were demonstrated. Grapefruit consumption was associated with modest weight loss (-0.61 ± 2.23 kg, P = .097), a significant reduction in waist circumference (-2.45 ± 0.60 cm, P = .0002), and a significant reduction in systolic blood pressure (-3.21 ± 10.13 mm Hg, P = .03) compared with baseline values. Improvements were observed in circulating lipids of those consuming grapefruit, with total cholesterol and low-density lipoprotein significantly decreasing by -11.7 mg/dL (P = .002) and -18.7 mg/dL (P < .001), respectively, compared with baseline values. This study suggests that consumption of grapefruit daily for 6 weeks does not significantly decrease body weight, lipids, or blood pressure as compared with the control condition. However, the improvements in blood pressure and lipids demonstrated in the intervention group suggest that grapefruit should be further evaluated in the context of obesity and cardiovascular disease prevention.

Effect of High-Dose Statin Versus Low-Dose Statin Plus Ezetimibe on Endothelial Function

Background:

Combining low-dose statin and ezetimibe reduces the low-density lipoprotein cholesterol (LDL-C) similar to high-dose statin. However, whether there is a difference in the effect of these 2 lipid-lowering regimes on endothelial function is still controversial.

Methods:

We performed a systematic search of databases (MEDLINE [1950 to September 2011], EMBASE [1966 to September 2011]) and references of identified studies. Completely published randomized controlled trials comparing the effect of high-dose statin with low-dose stain plus ezetimibe on endothelial function (flow-mediated dilation [FMD] method) were included in this study.

Results:

Six trials with a total of 213 participants were included in the meta-analysis. The pooled weighted mean difference of FMD did not differ between the 2 lipid-lowering regimes (0.22%; 95% confidence interval [CI]: −0.85%-1.29%, P = .68). Furthermore, no significant reduction in LDL-C and C-reactive protein (CRP) occurred with high-dose statin versus low-dose statin plus ezetimibe (pooled weighted mean differences of LDL-C and CRP were −4.12 mg/dL, 95% CI: −9.54-1.12 mg/dL, P = .12, and −0.02 mg/L, 95% CI: −0.31-0.27 mg/L, P = .89, respectively).

Conclusions:

Based on the currently available evidence, combining a low-dose statin with ezetimibe may provide similar beneficial effects on endothelial function as high-dose statin.

Intestinal sterol transporters and cholesterol absorption inhibition

PURPOSE OF REVIEW

Statin therapy is the mainstay of lipid-lowering therapy; however, many patients, particularly those at high risk, do not achieve sufficient LDL-cholesterol (LDL-C) lowering. Thus, there remains an unmet medical need for more effective and well tolerated lipid-lowering agents. Guidelines recommend combining additional lipid-lowering agents with a complementary mode of action for these patients. One approach to complementing statin therapy is combination with inhibitors that block the intestinal absorption of dietary and biliary cholesterol. This review summarizes what is currently known about intestinal sterol transporters and cholesterol absorption inhibitors (CAIs).

RECENT FINDINGS

The only lipid-lowering agent currently available that specifically targets an intestinal sterol transporter (Niemann-Pick C1-like 1) is the CAI, ezetimibe. It is effective in lowering LDL-C, both when given alone and when combined with a statin. Clinical outcome data with ezetimibe combined with simvastatin have recently become available, and definitive evidence that the incremental LDL-C lowering attributable to the ezetimibe component reduces cardiovascular events beyond simvastatin alone is currently under study. Other novel CAIs have been evaluated based upon the structure and properties of ezetimibe, but none remain in development.

SUMMARY

Additional lipid-lowering agents are needed to fulfill an unmet medical need for those patients who do not achieve optimal LDL-C goals on statin monotherapy. The inhibition of cholesterol absorption is an important therapeutic strategy to reduce cholesterol levels. Based upon the demonstrated lipid-altering efficacy and safety of ezetimibe, several CAIs have been identified; all to date have been discontinued due to limited efficacy.

Short-term effect of atorvastatin on carotid artery elasticity: a pilot study

BACKGROUND AND PURPOSE

Few studies have examined the early effects of statins on carotid artery elasticity, a potential surrogate marker of cardiovascular risk. This study examined the short-term effects of atorvastatin 80 mg daily on carotid elasticity measured by high-resolution B-mode ultrasound.

METHODS

The study included 40 stroke-free and statin-naive subjects older than age 45 (mean age, 70±7 years; 55% men; 64% Caribbean-Hispanic). Outcome measures included carotid stiffness indices at 14 and 30 days after initiation of treatment. The systolic and diastolic diameters of the right common carotid artery were averaged from multiple B-mode imaging frames. Absolute and relative changes of strain [(systolic diameter-diastolic diameter)/diastolic diameter], stiffness (β) [ln (systolic/diastolic blood pressure)/strain], and distensibility (1/β adjusted for wall thickness) from baseline were compared by the repeated measures t test and were considered significant at α=0.05.

RESULTS

Baseline mean stiffness was 0.08 (95% confidence interval [CI], 0.06-0.10). It significantly decreased at day 30 to 0.05 (CI, 0.04-0.06; P<0.01). Mean baseline distensibility was 15.25 (CI, 13.18-17.32), increasing significantly at day 30 to 17.23 (CI, 14.01-20.45; P<0.05). An improvement in distensibility of ≥10% from baseline was observed in 29 (73%) subjects. Changes in stiffness and distensibility were maximal among subjects with baseline low-density lipoprotein levels<130 mg/dL.

CONCLUSIONS

Short-term treatment with high-dose atorvastatin was associated with improvement in the carotid elasticity metrics. Carotid artery elasticity measured by B-mode ultrasound is a simple noninvasive measure of arterial wall function and may be a useful surrogate end point in clinical trials targeting individuals at increased risk for atherosclerosis.

Where are we heading with noninvasive clinical vascular physiology? Why and how should we assess endothelial function?

There are several invasive and noninvasive methods available to the clinical researcher for the assessment of endothelial function. The first investigations in humans involved invasive pharmacological vascular function testing, which have been used to gain a detailed understanding of the mechanisms involved in the pathogenesis of endothelial dysfunction and atherosclerosis as well as novel targets for intervention. Techniques for endothelial function testing have evolved over time from these invasive methods, which, by their nature, are restricted to small studies in the research laboratory, to more standardized noninvasive methods, which are suitable for use in large prospective cohort studies and clinical trials. This paper describes currently available methods for assessment of endothelial function and their potential application in cardiovascular research and clinical practice.

Recent development in pleiotropic effects of statins on cardiovascular disease through regulation of transforming growth factor-beta superfamily

BACKGROUND

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, also known as statins, are a drug class that reduce the level of cholesterol in the blood. As a result, statins are used to suppress the progression of cardiovascular disease. Evidence points to another component of statins involving the non-lipid effects of the drug class in preventing cardiovascular disease. One specific mediator of this action is the transforming growth factor β (TGF-β) superfamily. The TGF-β superfamily consists of proteins that include TGF-β and bone morphogenetic proteins (BMPs). These proteins regulate cellular pathways to mediate effects including immunomodulation, cell cycling, and angiogenesis. One pathway that mediates these effects is Ras. Moreover, within this pathway, different functions are possible depending on the activation of the specific receptor subtype. This review discusses the recent development of the non-lipid effects of statins in preventing cardiovascular disease progression by regulating Ras pathway of the TGF-β superfamily, especially RhoA/ROCK pathway.

METHODS

A systematic PubMed database search of all English-language articles up to 2011 was conducted using the following terms: statin, TGF-β, Ras, ROCK, GGPP, inducible nitric oxide synthase, endothelial nitric oxide synthase, actin filament formation, PPARγ, MMP-2, and human trials.

CONCLUSION

With better understanding of the pathway, various mediators were identified; some of these mediators are important biomarkers producing more specific and accurate assessment of the pleiotropic effects of statins. The review of human trials also highlights that more specific biomarkers are employed in recent studies, and the non-lipid effects on human subjects are more accurately documented. Confirmation of the accuracy of these biomarkers by further large-scale studies and further development of new biomarkers may prove an important path leading to better patient selection for treatment, and thus better cost-effectiveness may be achieved.

Comparison of the effects of combination atorvastatin (40 mg) + ezetimibe (10 mg) versus atorvastatin (40 mg) alone on secretory phospholipase A2 activity in patients with stable coronary artery disease or coronary artery disease equivalent

Secretory phospholipase A2 (sPLA2) is an enzyme that plays an important role in the pathogenesis of atherosclerosis and of adverse cardiovascular events. It is currently the target of emerging therapeutic agents. Our study was designed to investigate the effect of aggressive lowering of low-density lipoprotein (LDL) cholesterol with ezetimibe and atorvastatin on sPLA2 activity. We randomized 100 patients with stable coronary artery disease (CAD) or CAD equivalent (diabetes, stroke, or peripheral vascular disease) to receive ezetimibe 10 mg/day in association with atorvastatin 40 mg/day (combination therapy group) versus atorvastatin 40 mg/day and placebo (monotherapy group). Patients on statin therapy before inclusion were allowed to enter the study as long as the potency of the statin was lower than atorvastatin 40 mg/day. Lipid profile, high-sensitivity C-reactive protein (hs-CRP), and sPLA activity were measured at baseline and after 8 weeks of therapy. The decrease in LDL cholesterol was more significant in the combination therapy group, but the decrease in hs-CRP was similar. sPLA2 activity significantly decreased in the ezetimibe/atorvastatin group from 29 U/ml (interquartile range 23 to 35) to 26 U/ml (23 to 29, p = 0.001) but remained similar in the placebo/atorvastatin group (23 U/ml, 19 to 32, vs 22 U/ml, 19 to 28, p = NS). In a multivariate stepwise linear regression model, change in sPLA2 correlated with change in hs-CRP (p <0.001), baseline LDL cholesterol level (p = 0.001), body mass index (p = 0.003), diabetes mellitus (p = 0.04) and combination therapy with ezetimibe/atorvastatin (p = 0.05). In conclusion, this study demonstrates that coadministration of ezetimibe and atorvastatin decreases sPLA2 activity.

Comparative efficacy of the addition of ezetimibe to statin vs statin titration in patients with hypercholesterolaemia: systematic review and meta-analysis

OBJECTIVE

To systematically review and analyse evidence for cholesterol-lowering efficacy of at least 4 weeks of add-on ezetimibe vs doubling statin dose, in adults with primary hypercholesterolaemia.

RESEARCH DESIGN AND METHODS

MEDLINE, EMBASE and Cochrane databases were searched to identify randomised controlled trials of ezetimibe-statin combination vs statin titration (January 1993 - March 2010). Studies were selected using predefined criteria. Two reviewers conducted screening of articles, critical appraisal and data extraction; a third reviewer resolved disagreements. The difference between treatments was analysed for four co-primary outcomes: mean percentage change from baseline in low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and total cholesterol (TC); and proportion of patients achieving LDL-C treatment goal. Data were combined by two sets of direct comparison fixed and random effects meta-analysis: (1) compared data in the same treatment period between groups; (2) compared the incremental change in lipid levels of add-on ezetimibe vs doubling statin dose. Heterogeneity was assessed using the I(2) statistic.

RESULTS

Thirteen studies including 5080 patients were included in the meta-analyses. Data on simvastatin, atorvastatin and rosuvastatin were analysed. Results for primary and secondary outcomes were in favour of the ezetimibe-statin combination. A significantly greater percentage reduction in LDL-C levels was achieved in patients treated with ezetimibe-statin vs statin monotherapy (weighted mean difference [WMD]: -14.1% [-16.1, -12.1], p < 0.001). Reduction in LDL-C levels attributed to add-on ezetimibe was significantly greater than that for statin dose doubling (WMD: -15.3% [-19.1, -11.4], p < 0.001). Achievement of LDL-C goal favoured add-on ezetimibe over statin titration and was statistically significant (odds ratio: LDL-C treatment goal 2.45 [1.95, 3.08], p = 0.007).

CONCLUSIONS

Meta-analyses were restricted by the limited number of studies with similar trial design and method of statin titration. Results indicate that add-on ezetimibe is significantly more effective in reducing LDL-C levels than doubling statin dose, enabling more patients to achieve LDL-C goal.

Effects of ezetimibe added to ongoing statin therapy on C-reactive protein levels in hypercholesterolemic patients

BACKGROUND AND OBJECTIVES

Ezetimibe alone does not decrease C-reactive protein (CRP) levels in hypercholesterolemic patients. However, several reports have suggested that ezetimibe might potentiate the effect of statin not only on cholesterol but also on CRP when administered together. We investigated the effect of ezetimibe on CRP levels in patients taking statins.

SUBJECTS AND METHODS

Patients who had not achieved recommended low density lipoprotein-cholesterol (LDL-C) goals with statin therapy were divided into two groups, the ezetimibe group (n=60) and the control group (n=60). A third group of hypercholesterolemic patients without statin therapy was treated with statin (n=59). Patients with CRP level 10 mg/L were excluded. Lipid and CRP levels were measured before therapy commenced, and after 2 months of therapy.

RESULTS

Ezetimibe decreased cholesterol and LDL-C levels by 20.2% (p=0.000) and 28.1% (p=0.000) respectively. However, ezetimibe did not reduce CRP levels (from 0.83±0.68 to 1.14±1.21 mg/dL, p=0.11). CRP levels remained unchanged in the control group (p=0.42). In contrast, statin lowered CRP levels (from 0.82±0.73 to 0.65±0.57 mg/dL, p=0.008). In patients taking statins, changes in CRP levels were not associated with changes in LDL-C (r=-0.02, p=0.87), but with baseline CRP levels (r=-0.38, p=0.000).

CONCLUSION

Ezetimibe failed to reduce CRP levels in hypercholesterolemic patients taking statins despite significant reduction of LDL-C. This finding suggests that the anti-inflammatory effect of statin may not be secondary to cholesterol reduction, but via other mechanisms.

Combination therapy of statin and ezetimibe for the treatment of familial hypercholesterolemia

High-dose potent statin therapy in combination with ezetimibe is now standard practice for the treatment of adult patients with heterozygous familial hypercholesterolemia (heFH), as the result of numerous studies in patients with primary hypercholesterolemia or heFH. These studies have shown the combination to be both effective and safe in the short to medium term. Recently, short-term ezetimibe therapy has also been shown to be effective and safe in combination with statin therapy for children and adolescents with heFH. Effective statin–ezetimibe combination therapy is capable of achieving near-normal lipid profiles in heFH patients, with expected improvement in risk for cardiovascular disease (CVD) and improved life expectancy resulting predominantly from reduction in levels of low-density lipoprotein cholesterol. There are few data to support a pleiotropic action of ezetimibe with regard to CVD benefit, unlike therapy with statins. No serious and unexpected clinical adverse effects of combination statin–ezetimibe therapy have emerged till date, although data are limited in children and adolescents, for whom longer-term studies are required. Recent data suggesting possible proatherogenic effects of ezetimibe require confirmation. One large long-term randomized controlled clinical outcomes trial is in progress in non-FH patients to determine the efficacy and safety of ezetimibe therapy; it is unlikely that such a trial will ever be performed in patients with FH.

Potential therapeutic uses for ezetimibe beyond lowering LDL-c to decrease cardiovascular events

Ezetimibe is a relatively new drug that inhibits the absorption of dietary cholesterol in the small intestine. It is a low density lipoprotein-cholesterol (LDL-C) lowering medication that acts directly on the intestine by inhibiting Niemann-Pick C1 Like1 (NPC1L1). Recently, results of the ARBITER 6-HALTS trial (Arterial Biology for the Investigation of the Treatment Effects of Reducing Cholesterol 6-HDL and LDL Treatment Strategies) and the ENHANCE trial (Ezetimibe and Simvastatin in Hypercholesterolemia Enhances Atherosclerosis Regression) showed that ezetimibe had no effect on atherosclerosis despite producing a marked decrease in LDL-C. Recent studies show a potential benefit of ezetimibe in treating insulin resistance, non-alcoholic fatty liver disease (NAFLD), gallstones and dyslipidaemia associated with chronic renal failure and organ transplantation. All of these conditions are known to be associated with an increase in risk of cardiovascular disease (CVD) and further studies are needed to assess the potential benefits of ezetimibe in these therapeutics areas.