Single LDL apheresis improves endothelium-dependent vasodilatation in hypercholesterolemic humans

Impaired endothelial nitric oxide bioavailability: a common link between aging, hypertension, and atherogenesis?

Endothelial-derived nitric oxide (NO) is responsible for maintaining continuous vasodilator tone and for regulating local perfusion and systemic blood pressure. It also has significant antiproliferative effects on vascular smooth muscle and platelet anti-aggregatory effects. Impaired endothelial-dependent (NO mediated) vasorelaxation is observed in most animal and human models of healthy aging. It also occurs in age-associated conditions such as atherosclerosis and hypertension. Such "endotheliopathy" increases vascular risk in older adults. Studies have indicated that pharmacotherapeutic intervention with angiotensin-converting enzyme inhibitors and 3-hydroxy-3-methyl-glutaryl coenzyme-A reductase inhibitors may improve NO-mediated vasomotor function. This review, evaluates the association between impaired endothelial NO bioavailability, accelerated vascular aging, and the age-associated conditions hypertension and atherogenesis. This is important, because pharmacotherapy aimed at improving endothelial NO bioavailability could modify age-related vascular disease and transform age into a potentially modifiable vascular risk factor, at least in a subpopulation of older adults.

Improvement of endothelial dysfunction in acromegaly after transsphenoidal surgery

Flow-mediated vasodilatation (FMD) is a vascular functional test to detect endothelial dysfunction at the early stage of cardiovascular diseases. Patients with active acromegaly have higher morbidity and mortality due to cardiovascular events. To determine whether active acromegaly is associated with endothelial dysfunction, we studied 17 patients with active acromegaly for measurements of FMD, carotid intima-media thickness (IMT) and brachial-ankle pulse wave velocity (baPWV), and other biochemical parameters before and 3 months after transsphenoidal surgery (TSS). Baseline %FMD in patients with active acromegaly was significantly lower than that in age- and sex-matched control subjects. After TSS, the mean %FMD in acromegaly significantly increased from 5.3% to 7.4%; 12 patients had increased %FMD (responders), whereas 5 patients had decreased or unchanged %FMD (non-responders). However, neither carotid IMT nor baPWV changed after TSS. Serum levels of GH, insulin-like growth factor (IGF)-1, total cholesterol, low-density lipoprotein cholesterol (LDL-C), hemoglobin HA(1C), fasting plasma glucose and insulin levels, and homeostasis model assessment (HOMA)-R significantly decreased, whereas high-density lipoprotein cholesterol significantly increased. Responders had significantly lower baseline %FMD than did non-responders and both insulin levels and HOMA-R significantly decreased in responders, but not in non-responders after TSS. Simple regression analysis revealed that the change of %FMD showed a significant negative correlation with that of LDL-C, but not of IGF-1 or GH, in responders. In conclusion, it is suggested that endothelial dysfunction associated with active acromegaly improves soon after TSS, which is related to LDL-C and/or insulin resistance, but not to excess GH and/or IGF-1 itself.

Effect of OS-0544, a selective estrogen receptor modulator, on endothelial function and increased sympathetic activity in ovariectomized rats

Estrogens are known to contribute to endothelial function and sympathetic activity, both of which are strongly associated with the pathogenesis of ischemic heart disease. In addition, estrogens improve impaired lipid profile, a risk factor of endothelial dysfunction. In this study, we investigated the effects of OS-0544, a structurally new selective estrogen receptor modulator (SERM), on endothelial function, sympathetic activity, and plasma cholesterol level in ovariectomized (OVX) rats. Female Sprague-Dawley rats were ovariectomized and orally treated with OS-0544 (or OS-0689, the (R)-enantiomer of OS-0544), or 17beta-estradiol (E2) for 4 weeks, starting the next days after ovariectomy or for 1 week, starting 6 weeks after ovariectomy. Ovariectomy significantly increased vasopressin-induced mean blood pressure (AVP-MBP) (57+/-3.3 mm Hg vs. 46+/-3.5 mm Hg, P<0.05) and decreased acetylcholine (Ach)-induced maximum vasorelaxation response (69+/-5.6% vs. 81+/-4.0%, P<0.05). OS-0544 significantly inhibited AVP-MBP elevation (46+/-3.5 mm Hg vs. 57+/-3.3 mm Hg, P<0.05) and decreased Ach-induced maximum vasorelaxation response (90+/-3.3% vs. 69+/-5.6%, P<0.05) in OVX rats. In addition, OS-0689 as well as E2 significantly reduced (up to 67%) the increase in sympathetic activity in OVX rats. Moreover, like E2, OS-0544 significantly decreased plasma cholesterol level in OVX rats. These results demonstrate that OS-0544 has vascular protective effect on vascular function after ovariectomy. It is therefore believed that OS-0544 has vascular protective effect in postmenopausal woman.

New and emerging risk factors for CVD

Morphological and immunocytochemical studies have elucidated the complex processes involved in atherogenesis. The notion of plaque instability has emerged from this work and underscored the importance of inflammation in determining clinical complications associated with atherosclerosis, such as acute coronary syndrome. Cells of the immune system have been detected within atherosclerotic lesions and auto-antibodies directed against modified LDL and heat-shock proteins have been identified in the blood of individuals with atherosclerosis. The use of risk 'engines', e.g. the Framingham coronary risk score, has facilitated the identification of individuals at high risk, but the constituent classical risk factors used in these algorithms do not adequately differentiate individuals at moderate risk. As age is a major component of the equations used in these algorithms they are not particularly useful in young adults, and their applicability to non-Caucasian populations has been questioned. Biomarkers of early disease and plaque instability have therefore both been sought. Although some of these markers have been shown individually to be associated with a significant hazard ratio, no substantial improvement in discrimination has been demonstrated when they are incorporated into a risk 'engine'. The latter has generally been assessed by receiver operator characteristic curve analysis, although this approach has been criticised. Other modalities, including imaging and functional assessments of vascular function, are now being developed for clinical use.

Antioxidative effects of statins

HMG CoA reductase inhibitors (statins) have been shown to be effective lipid lowering agents and are beneficial in the primary and secondary prevention of coronary heart disease. However, the overall benefits observed with statins appear to be greater than what might be expected from changes in lipid levels alone and the positive effects have only partially been reproduced with other lipid lowering drugs, suggesting effects in addition to cholesterol lowering. In experimental models, many of the cholesterol-independent effects of statins are mediated by inhibition of isoprenoids, which serve as lipid attachments for intracellular signalling molecules such as small Rho guanosine triphosphate-binding proteins, whose membrane localization and function are dependent on isoprenylation. This review summarizes the effects of statins on endothelial function and oxidative stress.

Cholesterol lowering is more important than pleiotropic effects of statins for endothelial function in patients with dysglycaemia and coronary artery disease

AIMS

The importance of pleiotropic effects of statins on endothelial function and inflammatory markers was investigated in patients with dysglycaemia and coronary artery disease (CAD).

METHODS AND RESULTS

Thirty-nine patients were randomized to simvastatin 80 mg daily (S80; n = 20) or ezetimibe 10 mg and simvastatin 10 mg daily (E10/S10; n = 19) for 6 weeks, aiming at similar cholesterol reduction. Endothelial function, evaluated by brachial artery flow-mediated vasodilatation (FMD) and the effect of endothelin receptor blockade, serum lipids, and inflammatory markers were evaluated at baseline and follow-up. At follow-up, low-density lipoprotein cholesterol decreased from 3.1 (2.8-3.4) (median and quartiles) to 1.5 mmol/L (1.4-1.7) and from 3.0 (2.5-3.4) to 1.3 mmol/L (1.1-1.8), in the S80 and E10/S10 groups, respectively. In the entire study group, FMD increased from 4.3% (3.4-6.1) at baseline to 5.5% (3.4-6.6) at follow-up, while C-reactive protein decreased from 3.1 (1.7-7.6) to 2.3 mg/L (0.9-6.5). The changes in FMD and C-reactive protein from baseline to follow-up were not significantly different between patients on S80 and E10/S10 groups. Endothelin blockade enhanced endothelium-dependent vasodilatation both at baseline and follow-up.

CONCLUSION

Lipid lowering is more important than pleiotropic effects of statins for improvement in endothelial function and inflammatory markers in patients with dysglycaemia and CAD.

Protein adsorption during LDL-apheresis: proteomic analysis

BACKGROUND

The aim of our study was to investigate the clearance of functional proteins by different low-density lipoprotein-apheresis (LDL-A) methods with the help of proteomic analyses.

METHODS

Proteins were eluated from the different LDL-A columns and investigated with 2D electrophoresis combined with mass spectrometry methods. In parallel, we quantified the plasma protein loss from patients treated with double-filtration plasmapheresis (DFPP; n = 9), direct adsorption of lipoproteins (DALI; n = 5) or heparin-induced extracorporeal LDL precipitation (HELP; n = 7) with routine laboratory methods and western blots.

RESULTS

Proteomic analyses of the column-bound proteins revealed a column-type-dependent loss with the highest number of protein spots in DALI-treated patients (1001 +/- 36), followed by HELP (881 +/- 25) and DFPP (535 +/- 20). More than 70 functional proteins were identified. These proteins are involved in the coagulation pathway (e.g. kininogen1) and have adhesive (e.g. fibronectin), rheological (e.g. fibrinogen) and immunological/inflammatory properties (e.g. complement components). Quantification with western blot analyses demonstrated a significant depletion (P < 0.01) of these proteins comparing serum samples before and after the column with a systemic lowering in patients' serum.

CONCLUSIONS

These data reveal strong interaction between column and serum proteins during LDL-A. The clearance of proteins with adhesive, rheological, and inflammatory characteristics may have beneficial effects on microcirculation and reduce chronic inflammation but may also concomitantly induce side effects such as an increased bleeding risk.

Ezetimibe potently reduces vascular inflammation and arteriosclerosis in eNOS-deficient ApoE ko mice

OBJECTIVE

Hypercholesterolemia is associated with decreased vascular nitric oxide bioavailability and deletion of endothelial nitric oxide synthase (eNOS) markedly accelerates atherosclerosis development in apolipoprotein E knockout (apoE ko) mice. The current study tests whether atheroprotection provided by a lipid lowering therapy with Ezetimibe depends on eNOS.

METHODS/RESULTS

ApoE ko and apoE/eNOS double ko (dko) mice received a high fat diet with or without 0.05% Ezetimibe. Ezetimibe significantly reduced plasma cholesterol concentrations and atherogenic lipoproteins in both genotypes to a similar extent. Moreover, the drug reduced vascular inflammation, as it significantly reduced vascular cell adhesion molecule-1 (VCAM-1) expression and vascular CD14 expression, a marker for mononuclear cell infiltration, in both genotypes. Neither NOS protein expression nor vascular reactivity of aortic rings was changed in apoE ko mice following Ezetimibe treatment. Significant lesion reduction was seen in Ezetimibe-treated male and female apoE ko and apoE/eNOS dko animals (p<or=0.05). Interestingly, the drug-mediated additional atheroprotection in male apoE ko, compared to male eNOS dko mice, suggesting that lipid lowering does provide additional eNOS-dependent atheroprotection in this experimental group.

CONCLUSION

Lipid lowering with Ezetimibe potently reduces atherosclerosis and vascular inflammation independent of eNOS. Moreover, Ezetimibe did not exert any effects on eNOS protein expression or enzyme activity. However, additional atheroprotection by Ezetimibe was observed in eNOS competent apoE ko mice, suggesting that some of the drug's anti-atherosclerotic effects are mediated by the eNOS pathway.

Endothelial dysfunction in diabetes mellitus

Diabetes mellitus is associated with an increased risk of cardiovascular disease, even in the presence of intensive glycemic control. Substantial clinical and experimental evidence suggest that both diabetes and insulin resistance cause a combination of endothelial dysfunctions, which may diminish the anti-atherogenic role of the vascular endothelium. Both insulin resistance and endothelial dysfunction appear to precede the development of overt hyperglycemia in patients with type 2 diabetes. Therefore, in patients with diabetes or insulin resistance, endothelial dysfunction may be a critical early target for preventing atherosclerosis and cardiovascular disease. Microalbuminuria is now considered to be an atherosclerotic risk factor and predicts future cardiovascular disease risk in diabetic patients, in elderly patients, as well as in the general population. It has been implicated as an independent risk factor for cardiovascular disease and premature cardiovascular mortality for patients with type 1 and type 2 diabetes mellitus, as well as for patients with essential hypertension. A complete biochemical understanding of the mechanisms by which hyperglycemia causes vascular functional and structural changes associated with the diabetic milieu still eludes us. In recent years, the numerous biochemical and metabolic pathways postulated to have a causal role in the pathogenesis of diabetic vascular disease have been distilled into several unifying hypotheses. The role of chronic hyperglycemia in the development of diabetic microvascular complications and in neuropathy has been clearly established. However, the biochemical or cellular links between elevated blood glucose levels, and the vascular lesions remain incompletely understood. A number of trials have demonstrated that statins therapy as well as angiotensin converting enzyme inhibitors is associated with improvements in endothelial function in diabetes. Although antioxidants provide short-term improvement of endothelial function in humans, all studies of the effectiveness of preventive antioxidant therapy have been disappointing. Control of hyperglycemia thus remains the best way to improve endothelial function and to prevent atherosclerosis and other cardiovascular complications of diabetes. In the present review we provide the up to date details on this subject.

Ezetimibe's effect on platelet aggregation and LDL tendency to peroxidation in hypercholesterolaemia as monotherapy or in addition to simvastatin

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Statins demonstrate a pleiotropic effect which contributes beyond the hypocholesterolaemic effect to prevent atherosclerosis.

WHAT THIS STUDY ADDS

Ezetimibe has an antioxidative effect when given as monotherapy or as an add-on to the statin, simvastatin. AIMS To investigate the effect of lowering low-density lipoprotein-cholesterol (LDL-C) on platelet aggregation and LDL tendency to peroxidation by ezetimibe alone or with simvastatin in hypercholesterolaemia.

METHODS

Sixteen patients with LDL-C >3.4 mmol l(-1) received ezetimibe for 3 months (Part I). Twenty-two patients on fixed simvastatin dose with LDL-C >2.6 mmol l(-1) were enrolled (Part II). Part II patients continued simvastatin treatment 20 mg day(-1) for 6 weeks, then received 20 mg day(-1) simvastatin combined with ezetimibe 10 mg day(-1) for another 6 weeks. The tendency of LDL to peroxidation measured by lag time in minutes required for initiation of LDL oxidation and by LDL oxidation at maximal point (plateau) was measured before and after ezetimibe treatment.

RESULTS

Part I: Ezetimibe 10 mg daily for 3 months decreased plasma LDL-C level 16% (P = 0.002), prolonged lag time to LDL oxidation from 144 +/- 18 min to 195 +/- 16 min (P < 0.001), decreasing maximal aggregation from 83 +/- 15% to 60 +/- 36% (P = 0.04). Part II: Serum level LDL-C decreased 23% (P = 0.02) and lag time in minutes to LDL oxidation was prolonged from 55.9 +/- 16.5 to 82.7 +/- 11.6 (P < 0.0001) using combined simvastatin-ezetimibe therapy. There were no differences in platelet aggregation.

CONCLUSIONS

Ezetimibe was associated with decreased platelet aggregation and LDL tendency to peroxidation. Treatment with ezetimibe in addition to simvastatin has an additive antioxidative effect on LDL.

Applications of LDL-apheresis in nephrology

LDL-apheresis (LA) was originally used for familial hyperlipidemia, and then in Japan extended to use for the treatment of patients with peripheral arterial disease (PAD) and nephrotic syndrome due to steroid-resistant focal glomerular sclerosis (FGS). The reason why this treatment is applicable for these disorders is due to the fact that LA exerts its favorable effects beyond the lipid-lowering effect. The main underlying mechanisms, for example, in the case of LA application in patients with PAD are: (1) improvement of hemorheology, (2) improvement of endothelial dysfunction, (3) elevations of serum levels of NO and bradykinin, (4) increase in serum levels of vascular endothelial growth factor, and (5) reduction of adhesion molecules on monocytes. Furthermore, we have reported that LA could have anti-inflammatory effects because LA reduces serum levels of P-selectin, which is known to play an important role in the development of atherosclerosis as well as a reduction of serum C-reactive protein levels as standard biomarker of atherosclerosis. Massive proteinuria is also an important challenge in nephrology. The possible mechanisms besides removal of toxic lipids are the reduction of the vasoconstrictive prostanoid and thromboxane A2 (TXA2) and an improvement in macrophage function evidenced by a significant amelioration of interleukin-8 production by lipopolysaccharide-stimulated peripheral blood mononuclear cells. It is intriguing to note that in terms of pharmacodynamics, LA improves steroid and cyclosporine uptake into lymphocytes. Although there are no randomized controlled trials, it is clear that LA has various effects beyond lowering lipids. Making the device more concise and changing it into a whole blood adsorption type, we need to collect more clinical cases and to study the underlying mechanisms further.

Long-term effects of pravastatin and fosinopril on peripheral endothelial function in albuminuric subjects

The purpose of this double-blind, randomized, placebo-controlled trial was to determine the long-term effects of pravastatin and fosinopril treatment on peripheral endothelial function in subjects with albuminuria. Subjects (mean age 51 years, 63% male) were randomized to pravastatin 40 mg or matching placebo and to fosinopril 20mg or matching placebo. Using high resolution ultrasound, flow-mediated dilation (FMD) and nitroglycerin-induced dilation (NID) was assessed at baseline and after 4 years of treatment in a total of 276 subjects. At baseline, mean+/-standard error FMD was 4.73+/-0.49% and NID was 10.86+/-0.67%. Pravastatin significantly reduced total cholesterol and LDL cholesterol (p<0.01) and randomization to pravastatin was associated with a non-significant improvement of 18.9% in FMD (+0.80+/-0.95, p=0.09), without a significant change in NID. Interestingly, pravastatin significantly increased FMD by 34.9% in men (+1.23, p=0.04), but only 1.1% in women (+0.06, p=0.95). Fosinopril was not associated with a change in FMD or NID despite significantly decreasing urinary albumin excretion, systolic and diastolic blood pressure (all p<0.01). In conclusion, after 4 years of follow-up, pravastatin treatment tended to increase FMD and this effect was predominantly present in men. Fosinopril treatment did not modify FMD during long-term follow-up.

Pleiotropic effects of statin therapy: molecular mechanisms and clinical results

Statins inhibit the enzyme 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, which is required for cholesterol biosynthesis, and are beneficial in the primary and secondary prevention of cardiovascular disease. Most of the benefits of statin therapy are owing to the lowering of serum cholesterol levels. However, by inhibiting HMG-CoA reductase, statins can also inhibit the synthesis of isoprenoids, which are important lipid attachments for intracellular signaling molecules, such as Rho, Rac and Cdc42. Therefore, it is possible that statins might exert cholesterol-independent or 'pleiotropic' effects through direct inhibition of these small GTP-binding proteins. Recent studies have shown that statins might have important roles in diseases that are not mediated by cholesterol. Here, we review data from recent clinical trials that support the concept of statin pleiotropy and provide a rationale for their clinical importance.

Simultaneous assessment of endothelial function, nitric oxide synthase activity, nitric oxide-mediated signaling, and oxidative stress in individuals with and without hypercholesterolemia

BACKGROUND

Endothelial function is impaired in hypercholesterolemia and atherosclerosis. Based on mostly indirect evidence, this impairment is attributed to reduced synthesis or impaired biological activity of endothelium-derived nitric oxide (NO). It was the aim of this study to directly estimate and compare whole-body NO production in normo- and hypercholesterolemia by applying a nonradioactive stable isotope dilution technique in vivo.

METHODS

We enrolled 12 normocholesterolemic and 24 hypercholesterolemic volunteers who were all clinically healthy. To assess whole-body NO synthesis, we intravenously administered l-[guanidino-((15)N(2))]-arginine and determined the urinary excretion of (15)N-labeled nitrate, the specific end product of NO oxidation in humans, by use of gas chromatography-mass spectrometry. In addition, we measured flow-mediated vasodilation (FMD) of the brachial artery, expression of endothelial NOS (eNOS) in platelets, plasma concentration of the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA), and urinary excretion of 8-isoprostaglandin F(2alpha) (8-iso-PGF(2alpha)).

RESULTS

After infusion of l-[guanidino-((15)N(2))]-arginine, cumulative excretion of (15)N-labeled-nitrate during 48 h was 40% [95% CI 15%-66%] lower in hypercholesterolemic than normocholesterolemic volunteers [mean 9.2 (SE 0.8) micromol vs 15.4 (2.3) micromol/l, P = 0.003]. FMD was on average 36% [4%-67%] lower in hypercholesterolemic than normocholesterolemic volunteers [6.3 (4.0)% vs 9.4 (4.6)%, P = 0.027]. Normalized expression of NOS protein in platelets was also significantly lower in hypercholesterolemic volunteers, whereas there were no significant differences in plasma ADMA concentration or urinary excretion of 8-iso-PGF(2alpha) between the 2 groups.

CONCLUSIONS

This study provides direct evidence for a decreased whole body NO synthesis rate in healthy people with hypercholesterolemia.

Statins and biomarkers of inflammation

Clinical and epidemiologic studies convincingly demonstrate that increased levels of low-density lipoprotein cholesterol promote premature atherosclerosis. Several large clinical trials have demonstrated that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) decrease cardiovascular events. The beneficial effects of statins may extend to mechanisms beyond cholesterol reduction. Evidence for the pleiotropic effects of statins is provided by recent clinical trials in which the benefit of statin drugs is manifest early in the course of lipid-lowering therapy, well before plaque regression could occur. Inflammation is pivotal in all stages of atherosclerosis, and C-reactive protein (CRP), the prototypic marker of inflammation, has emerged as a cardiovascular risk marker. Statins reduce CRP levels, and this reduction in most studies does not correlate to reduction in cholesterol. In addition, statins have beneficial effects on endothelial function, monocyte-macrophages, and platelets. In this review we discuss the role of inflammation in atherosclerosis, the role of CRP as a risk marker, the clinical evidence implicating the anti-inflammatory effects of statins, and the cellular and molecular basis underlying the anti-inflammatory effects of statins.

Blood Flow Analysis of the Head and Lower Limbs by the Laser Doppler Blood Flowmeter During LDL Apheresis

The presence of peripheral arterial disease substantially increases the risk for both morbidity and mortality among end-stage renal disease patients. Low-density lipoprotein (LDL) apheresis has been also applied for the treatment of peripheral arterial disease to reduce LDL levels, resulting in the improvement of the blood flow to the ischemic limbs. In this study, we investigated the continuous changes of the tissue blood flows in the lower limbs and head during LDL-apheresis treatment by a non-invasive method (the non-invasive continuous monitoring method (NICOMM) system). In this study, the tissue blood flow in both the head and lower limbs showed a significantly enhancement from before to after treatment. The tissue blood flow in the lower limbs showed a significantly larger improvement than that in the head. The short-term effects of LDL apheresis were confirmed by using the NICOMM system; thus, this system will be useful for the determination of the appropriate schedule of LDL apheresis for long-term effectiveness.

Efficacy of low-density lipoprotein apheresis in arteriosclerosis obliterans of the lower extremities: Two cases with marked alleviation of clinical symptoms

We have recognized marked effectiveness for intermittent claudication with low-density lipoprotein (LDL) apheresis in two cases of arteriosclerosis obliterans (ASO). The Case 1 was a 73-year-old man with intermittent claudication of both lower extremities (Fontaine class II), digital subtraction angiography (DSA) revealed complete obstruction of the left common iliac artery, formation of a collateral to the peripheral portion of the left common iliac artery, and diffuse stenosis of the peripheral portion of the right common iliac artery. Ten sessions of LDL apheresis (LDL-A) improved the walking distance from 100 m before to 600 m after LDL-A treatment. The Case 2 was a 61-year-old man with intermittent claudication of the left lower extremity (walking distance: 200 m) began at 59 years. DSA revealed diffuse stenosis of the peripheral portion of the left popliteal artery. Ten sessions of LDL-A improved the walking distance from 200 m before to 800 m after LDL-A. At one month after the end of LDL-A treatment, DSA revealed formation of collateral to the peripheral portion of the left popliteal artery. Our findings suggest that LDL-A combined with drug treatment is safe and useful for the treatment of ASO, especially walking distance improved with short term treatment.

Fibrinogen Apheresis in the Treatment of Peripheral Arterial Disease

BACKGROUND

Fibrinogen is mainly responsible for determining the viscosity of whole blood. In peripheral arterial disease (PAD) the fibrinogen concentration seems to affect the microcirculation flow.

AIM

To study the effects of an abrupt reduction of fibrinogen on the hemodynamics of the lower extremities and the clinical picture of patients with PAD.

METHODS

Ten patients affected by various stages of PAD underwent 1 session of fibrinogen apheresis (TheraSorb, Miltenyi Biotec, Germany). Laboratory parameters of endothelial activation were assessed before and after the session, as well as walking distance (WD), the ankle-brachial index and laser Doppler flowmetry.

RESULTS

A significant reduction in the laboratory parameters was observed: fibrinogen (50%), total cholesterol (18%), LDL cholesterol (24%), sE-selectin (23%), sICAM-1 (19%) and sVCAM-1 (10%). The procoagulant factors, factor VIII and von Willebrand factor, did not vary significantly. Both pain-free and total WD were significantly improved (p < 0.003 and p <0.006, respectively), the ankle-brachial index remained unchanged, and laser Doppler flowmetry showed a modest but not significant increase.

CONCLUSIONS

Fibrinogen apheresis allowed us to study the effects of an acute modification of fibrinogen in PAD, on both some aspects of the endothelial function and on the hemodynamics, demonstrating an improvement of WD and a minimal increase in the skin microcirculation.

Arterial stiffness or endothelial dysfunction as a surrogate marker of vascular risk

The understanding of the pathophysiology of atherosclerosis has advanced greatly in the past decade. Cardiovascular risk factors increase the likelihood of an adverse event by having a detrimental effect on the blood vessel wall. Abnormal interactions among cholesterol, inflammatory mediators, platelets and the vascular wall lead to atherogenesis and cardiac events. In an effort to better understand this process, develop surrogate end points for clinical trials and, ultimately, better risk stratify individuals, a variety of measures of arterial function have been studied. These include measures of endothelial health and arterial compliance. The current paper reviews the various techniques available for the study of vascular health. While not yet routinely used for clinical care, these measurements provide important insights into the pathophysiology and treatment of atherosclerosis.

Efficacy of low-density lipoprotein apheresis in patients with peripheral arterial occlusive disease undergoing hemodialysis treatment

BACKGROUND

Low-density lipoprotein (LDL) apheresis is effective in the treatment of peripheral arterial occlusive disease (PAOD). In the present study, we attempted to determine whether LDL apheresis is effective even for PAOD patients undergoing hemodialysis, who tend to be refractory to any treatment, and if so, to determine the mechanism of its efficacy.

METHODS

Serum levels of lipids and vascular growth factors, leg symptom, and endothelium-dependent vasodilation were investigated before and after 10 sessions of LDL apheresis in 11 PAOD patients undergoing hemodialysis.

RESULTS

Serum levels of total cholesterol, LDL cholesterol, and triglyceride exhibited drastic reduction, which completely disappeared 4 weeks after the final apheresis. Resting leg pain was improved in 6 cases even 4 weeks after final apheresis. Endothelium-dependent vasodilation was significantly increased 4 weeks after final apheresis (1.6 +/- 0.6 to 4.7 +/- 1.0%, p < 0.05). Levels of vascular growth factors, hepatocyte growth factor and vascular endothelial growth factor were not changed during treatment.

CONCLUSIONS

These findings suggested that LDL apheresis is effective even in PAOD patients undergoing hemodialysis. Our findings suggest that its mechanisms of efficacy include improvement of vascular endothelial dysfunction, in addition to drastic but acute reduction of lipid levels. Since PAOD patients undergoing hemodialysis tend to be resistant to any treatment and are at high risk for lower-extremity amputation, LDL apheresis could be a useful strategy for treatment of them.

Endothelial function, arterial stiffness and lipid lowering drugs

The endothelium is a dynamic organ that plays a pivotal role in cardiovascular homeostasis. Alteration in endothelial function precedes the development of atherosclerosis and contributes to its initiation, perpetuation and clinical manifestations. It has been suggested that the assessment of endothelial function could represent a barometer of vascular health that could be used to gauge cardiovascular risk. This review summarises the various methods used to assess endothelium-dependent vasodilatation and their potential prognostic implications. In addition, the techniques used to evaluate arterial stiffness are discussed. The latter is to some extent controlled by the endothelium and has been the subject of considerable research in recent years. This paper also discusses the effects of lipid lowering treatment on both endothelial function and arterial stiffness.

Ezetimibe and simvastatin reduce inflammation, disease activity, and aortic stiffness and improve endothelial function in rheumatoid arthritis

OBJECTIVES

The aim of this study was to investigate the effect of simvastatin and ezetimibe on inflammation, disease activity, endothelial dysfunction, and arterial stiffness in a cohort of rheumatoid arthritis (RA) patients.

BACKGROUND

Rheumatoid arthritis is a chronic inflammatory condition associated with increased cardiovascular risk. Statins reduce inflammation and disease activity in RA patients, but whether this is due to pleiotropism or cholesterol lowering per se is unclear.

METHODS

Twenty patients received 20 mg simvastatin or 10 mg ezetimibe each for 6 weeks in a randomized double-blind crossover study. Disease activity, blood pressure, aortic pulse wave velocity (PWV), brachial artery flow-mediated dilation (FMD), and serum inflammatory markers were measured before and after each treatment.

RESULTS

Both ezetimibe and simvastatin significantly reduced total cholesterol (-0.62 +/- 0.55 mmol/l and -1.28 +/- 0.49 mmol/l, respectively; p < 0.001), low-density lipoprotein cholesterol (-0.55 +/- 0.55 mmol/l and -1.28 +/- 0.49 mmol/l; p < 0.0001), and C-reactive protein (-5.35 +/- 9.25 mg/l and -5.05 +/- 6.30 mg/l; p < 0.001). Concomitantly, Disease Activity Score (-0.55 +/- 1.01 and -0.67 +/- 0.91; p = 0.002), aortic PWV (-0.69 +/- 1.15 m/s and -0.71 +/- 0.71 m/s; p = 0.001), and FMD (1.37 +/- 1.17% and 2.51 +/- 2.13%; p = 0.001) were significantly improved by both drugs.

CONCLUSIONS

This study demonstrates that both ezetimibe and simvastatin reduce disease activity and inflammatory markers to a similar extent in patients with RA. Therapy is also associated with a concomitant reduction in aortic PWV and improvement in endothelial function. This suggests that cholesterol lowering per se has anti-inflammatory effects and improves vascular function in RA.

The myocardial infarct size-limiting and antiarrhythmic effects of acyl-CoA:cholesterol acyltransferase inhibitor VULM 1457 protect the hearts of diabetic-hypercholesterolaemic rats against ischaemia/reperfusion injury both in vitro and in vivo

The study was designed to characterise the influence of a novel acyl-CoA:cholesterol acyltransferase inhibitor, VULM 1457, on the severity of myocardial ischaemia-reperfusion injury in a model of diabetes mellitus and hypercholesterolaemia induced by co-administration of streptozotocin and a high fat-cholesterol diet. We used Langendorff-perfused rat hearts to measure the size of myocardial infarction after 30 min of regional ischaemia, followed by a 2-h reperfusion period, and open-chest rats were exposed to 6 min of ischaemia and 10 min of reperfusion to analyse ventricular arrhythmias. In addition to the high fat-cholesterol diet, VULM 1457 was administered to the diabetic-hypercholesterolaemic rats for 5 days. Decreased plasma and liver cholesterol levels and a significantly reduced occurrence of ventricular fibrillation (29% vs. 100%, P<0.01), determined via the mean number and duration of episodes (0.6+/-0.4 and 2.1+/-1.4 s vs. 2.8+/-0.8 and 53.5+/-14.4 s in diabetic-hypercholesterolaemic rats, both P<0.01), were observed in these animals. Lethal ventricular fibrillation was suppressed, and arrhythmia severity was also significantly decreased in these animals as compared to the non-treated animals (2.9+/-0.6 vs. 4.9+/-0.2; P<0.05). A smaller infarct size, normalised to the size of area at risk, was observed in the treated diabetic-hypercholesterolaemic group as compared to the non-treated group (16.3+/-1.9% vs. 37.3+/-3.1%; P<0.01). Aside from remarkable hypolipidaemic activity, VULM 1457 improved the overall myocardial ischaemia-reperfusion injury outcomes in the diabetic-hypercholesterolaemic rats by suppressing arrhythmogenesis as well as by reducing myocardial necrosis.

Effect on carotid atherosclerosis of probucol plus levofloxacin for Chlamydia pneumoniae infection

To investigate the effect of levofloxacin on carotid atherosclerosis, patients with hypercholesterolemia whose carotid atherosclerosis was not improved by probucol therapy (500 mg/day) for 24 months were enrolled. All patients were seropositive for anti C. pneumoniae IgA and/or IgG. Carotid atherosclerosis was evaluated by ultrasonic measurement of the maximum intima-media thickness (Max-IMT). All subjects were prescribed three courses of levofloxacin (each course, 400 mg/day for 2 weeks, followed by 14 days off drug treatment). At 12 months after combined therapy with probucol and levofloxacin, Max-IMT was significantly decreased compared with the value before treatment (P < 0.01). These results suggest that the combination therapy was effective for improving carotid atherosclerosis in C. pneumoniae-seropositive patients.

Simvastatin improves endothelial function in patents with subclinical hypothyroidism

Patients with subclinical hypothyroidism (SCH) have impaired endothelial function probably related to dyslipidemia. The present study compares the effects of simvastatin versus levothyroxine (LT-4) treatment on lipid profile and endothelial function in patients with SCH. Fifty-nine patients with newly diagnosed SCH were enrolled. Patients were randomized into 3 groups to receive no treatment (n = 19), LT-4 (n = 20), or simvastatin (n = 20). We measured endothelium-dependent vasodilation (EDV) and endothelium-independent vasodilation (EIV) at baseline and after 8 months. Serum total cholesterol, triglycerides and LDL-cholesterol were significantly lower following simvastatin. EDV increased significantly in simvastatin treatment group (7.5% +/- 3.3% vs 14.0% +/- 4.5% (P < 0.01). The improvement of EDV correlated with the percent decrease of LDL-cholesterol (rho = 0.68, P < 0.01). Although LT-4 therapy caused a trend towards an increase in EDV compared to baseline, statistical significance was not achieved. EIV remained unchanged in all three groups. Simvastatin but not LT-4 treatment significantly improves EDV of the brachial artery and dyslipidemia in patients with SCH. Improvement in brachial artery endothelial function may be related in part to a hypolipidemic effect of simvastatin treatment.

Nitric oxide mechanisms in the pathogenesis of global risk

Identification and management of cardiovascular risk factors, such as hypertension, diabetes mellitus, and dyslipidemia, is essential not only for prevention of cardiovascular disease, but also for slowing the progression of existing cardiovascular disease. A major underlying mechanism that links various cardiovascular risk factors and manifestations of cardiovascular disease is endothelial dysfunction, characterized by impaired nitric oxide bioactivity. Oxidative stress is an important cause of impaired nitric oxide bioactivity, and a major pathogenic mechanism of atherosclerosis. Several pharmacologic therapies, including angiotensin-converting enzyme inhibitors, calcium channel blockers, statins, and the vasodilating beta blocker nebivolol, have been shown to enhance nitric oxide bioactivity and improve endothelial function. This effect may help explain the cardioprotective benefits of these agents and may stimulate further use of nitric oxide modulation for the treatment of cardiovascular risk factors and manifestations of cardiovascular disease.

Improved coronary vasodilatatory capacity by H.E.L.P. apheresis: comparing initial and chronic treatment

Hypercholesterolemia impairs endothelial function and subsequently decreases coronary vasodilatatory capacity. We examined the quantitative effects of one single LDL apheresis on vasodilatatory capacity. Using N-13 ammonia as a tracer for dynamic quantitative positron emission tomography (PET), mean myocardial perfusion measurements were carried out before and 20 h later after LDL apheresis, both under resting conditions and after pharmacological vasodilatation with dipyridamole. LDL apheresis was carried out using the heparin induced extracorporeal LDL precipitation (H.E.L.P.) procedure. We examined 47 patients (12 women and 35 men), with angiographically-proven coronary artery disease. All of them suffered from hypercholesterolemia. Of the patients, 35 received a chronic weekly H.E.L.P. procedure (group A), while H.E.L.P. procedure treatment was started for the first time in 12 patients, who were subsequently enrolled in a chronic apheresis program (group B). H.E.L.P. apheresis was combined with cholesterol lowering drugs in all patients. Both groups underwent positron emission tomography twice (prior to LDL apheresis and 20 h later). In group A, LDL cholesterol levels decreased from 175 +/- 50 mg/dL to 60 +/- 21 mg/dL immediately after H.E.L.P. (77 +/- 25 mg/dL before the second PET). Corresponding values for fibrinogen levels were 287 +/- 75 mg/dL to 102 +/- 29 mg/dL (155 +/- 52 mg/dL), minimal coronary resistance dropped from 0.56 +/- 0.20 to 0.44 +/- 0.17 mm Hg x 100 g x min/mL (P < 0.0001). Plasma viscosity decreased by 7.8%. In group B, LDL cholesterol decreased from 187 +/- 45 mg/dL to 75 +/- 27 mg/dL (85 +/- 29 mg/dL) and fibrinogen from 348 +/- 65 mg/dL to 126 +/- 38 mg/dL (168 +/- 45 mg/dL). Minimal coronary resistance was reduced from 0.61 +/- 0.23 to 0.53 +/- 0.19 mm Hg x 100 g x min/mL (P < 0.01). Plasma viscosity was observed to decrease by 7.6%. The strong LDL drop in patients under chronic H.E.L.P. treatment has a significant impact on coronary vasodilatatory capacity within 20 h leading to an improved overall cardiac perfusion. Nearly the same effect can be seen in patients after their first H.E.L.P. treatment.

Measurement of plasma oxidized low-density lipoprotein and its clinical implications

Oxidized low-density lipoprotein (OxLDL) has been shown to exist in human circulating plasma. Several groups including ours have developed methods for immunologically measuring OxLDL, which have been applied to several clinical, both cross-sectional and prospective, studies. These data clearly show that OxLDL levels correlate well with the severity of cardiovascular diseases. In particular, recent observations suggest that plasma OxLDL levels could be a useful marker for predicting future cardiovascular events; however, substantial differences exist among the different methods of OxLDL measurement. To evaluate the clinical data on circulating OxLDL, a proper understanding of the similarity, differences, and limitation of the methods is needed. This paper summarizes the characteristics of the methods used and recent clinical findings.

LDL-apheresis reduces P-Selectin, CRP and fibrinogen -- possible important implications for improving atherosclerosis

Although it is known that LDL-apheresis improves coronary artery stenosis (CAS) as well as ischemic limbs seen in patients with peripheral arterial occlusive disease (PAOD), the underlying mechanisms remain still unknown. LDL-apheresis might exert its favorable action through anti-inflammatory effects. We studied whether or not serum or plasma levels of P-selectin, high sensitivity C-reactive protein (hsCRP), monocyte chemoattractant protein-1 (MCP-1) or fibrinogen could be reduced in patients with PAOD before and after 10 sessions of LDL-apheresis. Sixteen patients (12 patients with hemodialysis, HD) with PAOD were enrolled in the present study. LDL-apheresis was carried out 10 times (treated plasma of 3000 mL) over 5 weeks. Serum levels of P-selectin were significantly reduced from 516 +/- 153 to 290 +/- 52 ng/mL before and after 10-sessions of LDL-apheresis, respectively (P < 0.05). Likewise, serum levels of hsCRP decreased from 9.118 +/- 2.649 to 5.587 +/- 2.445 mg/L (P < 0.01); and plasma fibrinogen levels statistically decreased from 196 +/- 9.82 to 149 +/- 7.97 mg/dL (P < 0.01), whereas serum levels of MCP-1 were not significantly changed. The favorable actions of LDL-apheresis might include anti-inflammatory effects, which could lead to an improvement of CAS and PAOD. Moreover, this intervention might be applicable for patients with atherosclerotic cardiovascular disorders, particularly in patients with HD.

Novel therapies targeting vascular endothelium

Endothelial dysfunction has been identified as a major mechanism involved in all the stages of atherogenesis. Evaluation of endothelial function seems to have a predictive role in humans, and therapeutic interventions improving nitric oxide bioavailability in the vasculature may improve the long-term outcome in healthy individuals, high-risk subjects, or patients with advanced atherosclerosis. Several therapeutic strategies are now available, targeting both the synthesis and oxidative inactivation of nitric oxide (NO) in human vasculature. Statins seem to be currently the most powerful category of these agents, improving endothelial function and decreasing cardiovascular risk after long-term administration. Other cardiovascular agents improving endothelial function in humans are angiotensin-converting enzyme inhibitors/angiotensin receptors blockers, which increase NO bioavailability by modifying the rennin-angiotensin-aldosterone system. Newer therapeutic approaches targeting endothelial dysfunction in specific disease states include insulin sensitizers, L-arginine (the substrate for endothelial NO synthase [eNOS]) as well as substances that target eNOS "coupling," such as folates or tetrahydrobiopterin. Although there are a variety of strategies to improve NO bioavailability in human endothelium, it is still unclear whether they have any direct benefit at a clinical level.

Measures of Oxidative Stress

Development of in vivo markers of oxidative stress that are sensitive, specific, reliable, and accurate in reflecting underlying atherosclerotic disease states and prediction of cardiovascular risk and clinical events will be invaluable in the future in clinical medicine. Oxidized low-density lipoprotein (OxLDL) and isoprostanes are emerging plasma biomarkers that hold promise for cardiovascular risk prediction. This article describes the pathophysiology of OxLDL and isoprostanes as potential biomarkers, the rationale behind development of methods to measure OxLDL and isoprostanes, and a detailed description of current methodologies, including advantages and disadvantages of available assays. Clinical investigations consisting of epidemiological, case-control, and prospective studies are reviewed to elucidate the role of these biomarkers in reflecting pathophysiology and risk prediction.

Is the Efficacy of LDL Apheresis in Ischemic Optic Neuropathy Linked to a Reduction in Endothelial Activation Markers?

Endothelial dysfunction of the optic microcirculation is considered to be the main pathogenetic mechanism in nonarteritic ischemic optic neuropathy. The aim of the present work was to assess whether a clinical improvement is correlated with a reduction in the endothelial activation markers by means of LDL apheresis (LDLA). Three weekly sessions of LDLA were administered in 23 patients affected by nonarteritic ischemic optic neuropathy. Statistically significant reductions were achieved in all parameters: total cholesterol (44.6%), LDL cholesterol (54.6%), fibrinogen (60.9%), von Willebrand factor (38.6%), sE-Selectin (22.6%), sICAM-1 (14%) and sVCAM-1 (15.5%), each of which was correlated with an improvement in the mean deviation of the visual field, although statistical significance for the single parameters was not reached. However, analysis of variance between the mean deviation improvement and the set of parameters taken together yielded highly significant results (p < 0.0001). LDLA was effective in reducing the values of all evaluated endothelial activation markers, and this trend was correlated with an improvement in the visual field.

The olive constituent oleuropein exhibits anti-ischemic, antioxidative, and hypolipidemic effects in anesthetized rabbits

Thgoal of this study was to evaluate the efficacy of the antioxidant olive constituent, oleuropein, on infarct size, oxidative damage, and the metabolic profile in rabbits subjected to ischemia. Oleuropein, 10 or 20 mg/(kg x d), was administered to 8 groups that consumed a normal or hypercholesterolemic diet for 6 wk or only the higher dose for 3 wk. Circulating levels of malondialdehyde, protein carbonyl, nitrite+nitrate, cholesterol, triglycerides, SOD activity, and the metabolic profile were measured using 1H NMR spectra. In rabbits that consumed the normal diet, the infarct size (percentage of infarct to risk areas) was reduced by the administration of 10 mg oleuropein/(kg x d) (16.1 +/- 2.9%) or 20 mg oleuropein/(kg x d) for 3 wk (21.7 +/- 2.2%) or for 6 wk (24.3 +/- 1.3%) compared with the control group (48.05 +/- 2.0%, P < 0.05). Only the higher dose of 20 mg/(kg x d) reduced the infarct size in hypercholesterolemic rabbits (34.7 +/- 4.4% for 6 wk and 34.8 +/- 6.1% for 3 wk) compared with the cholesterol-fed control group (52.8 +/- 2.4%, P < 0.05). Oleuropein decreased the plasma lipid peroxidation product and protein carbonyl concentrations compared with the control groups, in which these factors increased relative to baseline due to ischemia and reperfusion. Furthermore, in rabbits administered oleuropein, RBC superoxide dismutase activity did not change during ischemia and reperfusion. This activity was significantly higher than in both control groups in which it was reduced by ischemia and reperfusion compared with baseline. Treatment for 6 wk with both doses of oleuropein reduced total cholesterol and triglyceride concentrations. 1H NMR spectra revealed a different profile of glycolysis metabolites in the oleuropein-treated groups compared with the controls. Oleuropein, for 3 or 6 wk, reduced the infarct size, conferred strong antioxidant protection and reduced the circulating lipids. This is the first experimental study in vivo that suggests the possibility of using an olive constituent in the treatment of ischemia.

LDL-apheresis therapy

Low-density lipoprotein (LDL)-apheresis is an effective means for acutely lowering plasma cholesterol (LDL reduction > 60%) and reducing cardiovascular events in patients with uncontrolled hypercholesterolemia who are genetically predisposed or resistant to standard therapy. Despite its known benefit, apheresis is performed in only a minority of qualified patients. In addition to reducing plasma cholesterol, apheresis can alter other markers of vascular disease (inflammation, rheology, thrombosis, and fibrinolysis). The acute and chronic changes to the vascular system may warrant LDL-apheresis use in other diseases.

Statins and the endothelium

Statins have been shown to have pleiotropic effects apart from serum lipid-lowering effect in human. One of the major target organs for the effects of statins is the vascular endothelium, which plays an important role in the development of atherosclerosis and angiogenesis. Recent numerous studies have shown that the statins' cholesterol-independent vascular effects appear to involve directly restoring or improving endothelial function by increasing NO production, promoting re-endothelialization after arterial injury, and inhibiting inflammatory responses within the vessel wall that are thought to contribute to atherosclerosis. This review provides an update of the unique effects of statins on endothelial cells including endothelial progenitor cells as well as highlighting the therapeutic potential of statins beyond their established lipid-lowering effects.

Effects of oral beraprost sodium, a prostaglandin I2 analogue, on endothelium dependent vasodilatation in the forearm of patients with coronary artery disease

1. Previous clinical studies with prostaglandin I(2) (PGI(2)) analogue beraprost sodium suggested the potential effects on protection of cardiovascular events in patients with peripheral artery disease. Although the mechanism is not well known, experimental studies have shown protective effects of endothelial cells. This study was designed to examine the effects of beraprost sodium on vascular endothelial function in the forearm of patients with coronary artery disease. 2. Beraprost sodium (120 microg/day) was orally administered to 14 coronary artery disease patients for 4 weeks and then stopped for 4 weeks. Eleven control patients did not receive beraprost sodium treatment. Reactive hyperemia was induced in the forearm, endothelium-dependent vasodilatation was assessed by plethysmography, and urinary 8-iso-prostaglandin F(2alpha) (8-iso-PGF(2alpha)) was measured at baseline, 4 weeks and 8 weeks. 3. Both groups had similar reactive hyperemic responses at baseline. In the control group, reactive hyperemic response and urinary 8-iso-PGF(2alpha) remained unchanged for 8 weeks. In the beraprost group, maximum forearm blood flow increased significantly (P = 0.01) after 4 weeks of treatment and returned to baseline at 8 weeks. Duration of hyperemia increased significantly (P = 0.003) after 4 weeks, and remained greater than baseline at 8 weeks (P = 0.02). Urinary 8-iso-PGF(2alpha) decreased significantly (P = 0.03) after 4 weeks, and tended to be lower at 8 weeks (P = 0.07). Changes in reactive hyperemia correlated weakly but significantly with changes in 8-iso-PGF(2alpha) (P < 0.001). 4. Beraprost sodium decreased oxidative stress and improved forearm endothelium-dependent vasodilatation in coronary artery disease patients. The favorable effects on vascular endothelium could potentially lead to a decrease in vascular events.

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

AIMS

Statin therapy is associated with improved endothelial vasodilator function. The clinical availability of ezetimibe, a potent novel cholesterol absorption inhibitor, enables to differentiate lipid-lowering effects from potential non-lipid-lowering (pleiotropic) mechanisms of statins.

METHODS AND RESULTS

Forearm blood flow (FBF) responses to acetylcholine (ACH) and sodium nitroprusside (SNP) were measured by venous occlusion plethysmography in four prospectively defined groups of patients with stable coronary artery disease (CAD) before and after 4 weeks of lipid-lowering therapy. Group A (n=15): de novo monotherapy with 10 mg/day ezetimibe; Group B (n=15): 10 mg/day ezetimibe as an add-on to chronic simvastatin therapy with 20 mg/day; Group C (n=15): dose escalation from chronic 10 to 40 mg/day atorvastatin; and Group D (n=15): de novo monotherapy with 40 mg/day atorvastatin. After 4 weeks of therapy, LDL cholesterol levels were significantly reduced in all four groups. Neither ezetimibe monotherapy (Group A) nor ezetimibe combined with 20 mg simvastatin (Group B) was associated with an increase in ACH-mediated FBF responses after 4 weeks. In contrast, dose escalation of atorvastatin from 10 to 40 mg/day (Group C) or de novo therapy with 40 mg atorvastatin/day (Group D) was associated with a significant increase in ACH-mediated FBF responses (P<0.013).

CONCLUSION

Thus, both statins and ezetimibe effectively lower LDL-levels within 4 weeks of therapy. However, only statin therapy is associated with improved endothelial vasodilator function, disclosing the relevance of pleiotropic effects of statins during short-term treatment of patients with CAD.

C-Reactive Protein and Other Emerging Blood Biomarkers to Optimize Risk Stratification of Vulnerable Patients

Several emerging plasma biomarkers may ultimately prove useful in risk stratification and prognosis of cardiovascular disease. The clinical utility of these biomarkers will depend on their ability to provide a reflection of the underlying atherosclerotic burden or activity; the ability to provide reliable, accurate, and cost-effective information; and the ability to predict future events. High-sensitivity C-reactive protein (hs-CRP) fulfills many, if not all, of these criteria, and blood levels of hs-CRP are now commonly used in clinical practice to improve vascular risk prediction in primary and secondary prevention across all levels of low-density lipoprotein-cholesterol (LDL-C), all levels of the Framingham Risk Score, and all levels of metabolic syndrome. High-sensitivity C-reactive protein may also have clinical relevance as an adjunct to LDL-C for both the targeting and monitoring of statin therapy. Accumulating evidence suggests that several other selected emerging biomarkers may also potentially prove useful in the diagnosis and prognosis of cardiovascular disease. Specifically, data are accumulating on the potential clinical utility of lipoprotein-associated lipoprotein-associated phospholipase A2, myeloperoxidase, oxidized LDL, lipoprotein (a), isoprostanes, and small, dense LDL. This review focuses on hs-CRP and these emerging plasma biomarkers, and their potential diagnostic and prognostic utility in cardiovascular disease. Plasma biomarkers that reflect the clinical potential of atherothrombotic disease may allow more precise risk stratification and prognostication in high-risk populations, and perhaps earlier diagnosis and intervention in patients at risk for or with occult cardiovascular disease.

Plant stanols do not restore endothelial function in pre-pubertal children with familial hypercholesterolemia despite reduction of low-density lipoprotein cholesterol levels

OBJECTIVE

To examine the effect of plant stanols on lipids and endothelial function in pre-pubertal children with familial hypercholesterolemia (FH).

STUDY DESIGN

Children with FH (n=42), aged 7-12 years, were enrolled in a double-blind crossover trial, in which they consumed 500 mL of a low-fat yogurt enriched with 2.0 g of plant stanols and 500 mL of a low-fat placebo yogurt for 4 weeks, separated by a 6-week washout period. Lipid profiles and endothelial function were assessed after both consumption periods. Endothelial function was measured as flow-mediated dilation (FMD) of the brachial artery.

RESULTS

This daily intake of 2.0 g of stanols significantly decreased the levels of total cholesterol (TC) by 7.5% and low-density lipoprotein cholesterol (LDL-C) by 9.2% as compared with placebo. High-density lipoprotein cholesterol and triglyceride levels remained unaltered. The reduction of LDL-C levels did not improve FMD, which was 10.5%+/-5.1% after plant stanol consumption and 10.6%+/-5.0% after placebo consumption, respectively (P=.852).

CONCLUSION

This study demonstrates that plant stanols reduce LDL-C levels in children with FH without improving endothelial function.