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Background: Persistent inflammation has been proposed to contribute to various stages in the pathogenesis of cardiovascular disease. Interleukin-6 receptor (IL6R) signalling propagates downstream inflammation cascades. To assess whether this pathway is causally relevant to coronary heart disease, we studied a functional genetic variant known to affect IL6R signalling., Methods: In a collaborative meta-analysis, we studied Asp358Ala (rs2228145) in IL6R in relation to a panel of conventional risk factors and inflammation biomarkers in 125,222 participants. We also compared the frequency of Asp358Ala in 51,441 patients with coronary heart disease and in 136,226 controls. To gain insight into possible mechanisms, we assessed Asp358Ala in relation to localised gene expression and to postlipopolysaccharide stimulation of interleukin 6., Findings: The minor allele frequency of Asp358Ala was 39%. Asp358Ala was not associated with lipid concentrations, blood pressure, adiposity, dysglycaemia, or smoking (p value for association per minor allele ≥0·04 for each). By contrast, for every copy of 358Ala inherited, mean concentration of IL6R increased by 34·3% (95% CI 30·4-38·2) and of interleukin 6 by 14·6% (10·7-18·4), and mean concentration of C-reactive protein was reduced by 7·5% (5·9-9·1) and of fibrinogen by 1·0% (0·7-1·3). For every copy of 358Ala inherited, risk of coronary heart disease was reduced by 3·4% (1·8-5·0). Asp358Ala was not related to IL6R mRNA levels or interleukin-6 production in monocytes., Interpretation: Large-scale human genetic and biomarker data are consistent with a causal association between IL6R-related pathways and coronary heart disease., Funding: British Heart Foundation; UK Medical Research Council; UK National Institute of Health Research, Cambridge Biomedical Research Centre; BUPA Foundation., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Background: MPO, an enzyme of the innate immune system, exhibits pro-atherogenic effects. These include oxidative damage to LDL- and HDL-cholesterol, and promotion of endothelial dysfunction. Recent studies revealed that MPO independently predicts adverse outcomes in patients with chest pain or suspected acute coronary syndrome. We evaluated whether plasma myeloperoxidase (MPO) levels are associated with scintigraphic myocardial perfusion abnormalities, in type 2 diabetic patients with mild anginal complaints., Methods: MPO was measured in plasma samples of 267 patients with diabetes mellitus type 2 and stable angina pectoris complaints (Canadian Cardiovascular Society class I-II/IV) prior to myocardial perfusion scintigraphy (MPS)., Results: The median plasma level of MPO was 141 pmol/L (IQR 115-171 pmol/L). One-hundred-ninety patients (71%) had perfusion abnormalities on MPS and of these, 138 patients had myocardial ischemia. No relation was found between plasma MPO levels and the scintigraphic myocardial perfusion abnormalities. Even in combination with known other cardiovascular risk factors MPO failed to predict scintigraphic myocardial perfusion abnormalities., Conclusions: MPO levels are not associated with scintigraphic myocardial perfusion abnormalities in type 2 diabetic patients with mild anginal complaints. Therefore, in type 2 diabetic patients MPO is not a useful biomarker to predict hemodynamically significant coronary artery disease., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Within the healthy population, there is substantial, heritable, and interindividual variability in the platelet response. We explored whether a proportion of this variability could be accounted for by interindividual variation in gene expression. Through a correlative analysis of genome-wide platelet RNA expression data from 37 subjects representing the normal range of platelet responsiveness within a cohort of 500 subjects, we identified 63 genes in which transcript levels correlated with variation in the platelet response to adenosine diphosphate and/or the collagen-mimetic peptide, cross-linked collagen-related peptide. Many of these encode proteins with no reported function in platelets. An association study of 6 of the 63 genes in 4235 cases and 6379 controls showed a putative association with myocardial infarction for COMMD7 (COMM domain-containing protein 7) and a major deviation from the null hypo thesis for LRRFIP1 [leucine-rich repeat (in FLII) interacting protein 1]. Morpholino-based silencing in Danio rerio identified a modest role for commd7 and a significant effect for lrrfip1 as positive regulators of thrombus formation. Proteomic analysis of human platelet LRRFIP1-interacting proteins indicated that LRRFIP1 functions as a component of the platelet cytoskeleton, where it interacts with the actin-remodeling proteins Flightless-1 and Drebrin. Taken together, these data reveal novel proteins regulating the platelet response.

Objective: We investigated the effectiveness of statins in daily practice in reducing the arterial wall thicknesses by comparing the carotid intima-media thickness (cIMT) between statin-treated familial hypercholesterolemia (FH) patients and their unaffected spouses., Methods: FH subjects treated with LDL-c lowering medication for at least 5 years and their unaffected spouses were included in this observational study. Clinical data and carotid intima-media thickness (cIMT) as surrogate marker for atherosclerosis were acquired., Results: In total 40 FH patients, age 48.4±4.2 years, and their 40 unaffected spouses, age 47.4±3.9 years, were included. Pre-treatment total cholesterol levels of FH patients were on average 9.3±2.0 mmol/L. Treated FH patients and unaffected spouses exhibited similar LDL-c (3.8±1.5 vs. 3.5±1.1 mmol/L; p=0.25) and total cholesterol levels (5.8±1.6 vs. 5.6±1.1 mmol/L; p=0.56). Also, in a multivariate model cIMT adjusted for age and sex did not differ between affected and spouses (95% CI: -0.032 to 0.092 mm; p=0.34)., Conclusion: Long-term statin treatment normalizes cIMT in severe FH patients and therefore it is likely that the extreme risk of cardiovascular disease in FH patients is significantly reduced by this therapy., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

To investigate the impact of mipomersen, an apolipoprotein B-100 (apoB) synthesis inhibitor, on intra-hepatic triglyceride content (IHTG content), we conducted a randomized, double-blind, placebo-controlled study in 21 patients with familial hypercholesterolemia (FH). Subjects received a weekly subcutaneous dose of 200 mg mipomersen or placebo for 13 weeks while continuing conventional lipid lowering therapy. The primary endpoint was change in IHTG content from week 0 to week 15 as measured by localized proton magnetic resonance spectroscopy (1H-MRS). Thirteen weeks of mipomersen administration reduced LDL-cholesterol by 22.0 (17.8) % and apoB by 19.9 (17.4) % (both P < 0.01). One of 10 patients (10%) in the mipomersen-treated group developed mild hepatic steatosis at week 15, which was reversible following mipomersen discontinuation. For the group, there was a trend toward an increase in IHTG content [placebo; baseline: 1.2% and week 15: 1.1%; change -0.1 (0.9). Mipomersen; baseline: 1.2% and week 15: 2.1%; change 0.8 (1.7) (P = 0.0513)]. Mipomersen administration for 13 weeks to subjects with FH is associated with a trend toward an increase in IHTG content. Future studies evaluating the effects of long-term use of mipomersen reaching more profound reductions in apoB are required prior to broader use of this compound.

Introduction: Myeloperoxidase (MPO), an antimicrobial enzyme of the innate immune system, has been proposed to exert a wide array of pro-atherogenic effects throughout all stages of the atherosclerotic process. In view of the potent anti-inflammatory effects of statins in vitro, we evaluated the impact of statin therapy on plasma MPO levels in patients with heterozygous familial hypercholesterolemia (FH), treated with either intensive or conventional lipid-lowering therapy. Furthermore, we evaluated the relation between MPO levels and atherosclerosis progression, as determined by intima media thickness (IMT)., Methods: We measured plasma MPO levels, lipoprotein profiles, high sensitivity-C-reactive protein (hs-CRP) as well as IMT of carotid artery segments in 122 FH patients at baseline and after 2-year treatment with atorvastatin 80 mg or simvastatin 40 mg QD., Results: Baseline median MPO values were 147pM (interquartile range (IQR) 122-217) and 144pM (IQR 118-216) and these increased significantly to 221pM (IQR 144-290) and 255pM (IQR 152-324) during 2-year follow-up in both the atorvastatin 80 mg and simvastatin 40 mg group, respectively. There was no correlation between MPO levels and IMT progression, change in lipoproteins or hs-CRP., Conclusion: In FH patients, statins do not prevent an increase in MPO levels during follow-up. Moreover, MPO levels are not associated with atherosclerosis progression in these patients.

Consumption of plant sterols and treatment with ezetimibe both reduce cholesterol absorption in the intestine. However, the mechanism of action differs between the two treatments, and the consequences of combination treatment are unknown. Therefore, we performed a double-blind, placebo-controlled, crossover study for the plant sterol component with open-label ezetimibe treatment. Forty mildly hypercholesterolemic subjects were randomized to the following treatments for 4 weeks each: 10 mg/day ezetimibe combined with 25 g/day control spread; 10 mg/day ezetimibe combined with 25 g/day spread containing 2.0 g of plant sterols; 25 g/day spread containing 2.0 g of plant sterols; and placebo treatment consisting of 25 g/day control spread. Combination treatment of plant sterols and ezetimibe reduced low density lipoprotein cholesterol (LDL-C) by 1.06 mmol/l (25.2%; P < 0.001) compared with 0.23 mmol/l (4.7%; P = 0.006) with plant sterols and 0.94 mmol/l (22.2%; P < 0.001) with ezetimibe monotherapy. LDL-C reduction conferred by the combination treatment did not differ significantly from ezetimibe monotherapy (-0.12 mmol/l or -3.5%; P = 0.13). Additionally, the plasma lathosterol-to-cholesterol ratio increased with all treatments. Sitosterol and campesterol ratios increased after plant sterol treatment and decreased upon ezetimibe and combination therapy. Our results indicate that the combination of plant sterols and ezetimibe has no therapeutic benefit over ezetimibe monotherapy in subjects with mild hypercholesterolemia.

Background: Pseudoxanthoma elasticum (PXE) is an inherited disorder of elastic tissue. We recently found that heterozygosity for the frequent (0.8% prevalence in Dutch population) R1141X mutation in the PXE gene coding for the ABCC6 transporter, is associated with a fourfold risk of premature coronary artery disease. Yet, it is not clear whether or not heterozygosity for this mutation results in a mild PXE phenotype. The objective of our study was to determine if skin and/or eye abnormalities related to a PXE phenotype could be found in patients with premature coronary artery disease, with and without the R1141X mutation., Methods: R1141X mutation carriers with premature coronary artery disease (cases) and patients with premature coronary artery disease with no-or not known-mutation (controls) were studied. Cases and controls were examined for PXE-like skin changes and retinal angioid streaks, peau d'orange or pigment epithelium changes., Results: 7 cases and 31 controls were analysed. In both the mutation-positive and the control group, skin inspection and eye fundus examination did not reveal any dermatological or ocular signs of PXE., Conclusions: Carriers for the ABCC6 R1141X mutation, which is frequent and confers a high risk of premature coronary artery disease, do not commonly have skin or eye abnormalities consistent with a mild PXE phenotype.

Background: High sensitivity C-reactive protein (hs-CRP) has emerged as the best studied and most promising marker of inflammation in atherosclerotic vascular disease., Materials and Methods: The ASAP (effects of Atorvastatin vs. Simvastatin on Atherosclerosis Progression) study was a 2-year randomised, double-blind trial with 325 familial hypercholesterolemia patients, treated with torvastatin 80 mg or imvastatin 40 mg. Intima media thickness (IMT) of carotid artery segments and hs-CRP levels were determined at baseline, 1 and 2 years., Results: Baseline median hs-CRP values were 2.1 mg/l (interquartile range (IQR) 0.9-5.2) and 2.0 mg/l (IQR 0.8-3.0) and after 2 years these levels decreased to 1.1 mg/l (IQR 0.6-2.4) and 1.5 mg/l (IQR 0.6-3.0) in the atorvastatin 80 mg and simvastatin 40 mg group, respectively. These changes were significant within as well as between the two groups. No correlations were observed between change in hs-CRP after 2 years and change in lipids. A significant correlation was found in univariate analysis between the decrease of hs-CRP and the reduction of IMT., Conclusions: Our results show that atorvastatin 80 mg reduces hs-CRP levels to a greater extent than simvastatin 40 mg. Furthermore, we show that the extent of hs-CRP reduction is associated with the progression rate of the atherosclerotic process as measured by IMT.

Background: High LDL-cholesterol is a risk factor for atherosclerosis. We aimed to determine whether aggressive cholesterol lowering with statins was more effective than conventional statin treatment in this disease. We investigated the effect of high-dose atorvastatin on carotid atherosclerosis progression., Method: We did a randomised, double-blind clinical trial in 325 patients with familial hypercholesterolaemia. Patients were given either atorvastatin 80 mg (n=160) or simvastatin 40 mg (n=165) daily, on an intent-to-treat basis. The primary endpoint was the change of carotid intima media thickness (IMT), as measured by quantitative B-mode ultrasound, over 2 years., Findings: The overall baseline IMT, combining the measurements of the common and internal carotid artery and the carotid bifurcation on both sides, was 0.93 mm (SD 0.22) and 0.92 mm (0.21) in the atorvastatin and simvastatin groups, respectively. After treatment with atorvastatin for 2 years, IMT decreased (-0.031 mm [95% CI -0.007 to -0.055]; p=0.0017), whereas in the simvastatin group it increased (0.036 [0.014-0.058]; p=0.0005). The change in thickness differed significantly between the two groups (p=0.0001). Atorvastatin showed greater reductions in cholesterol concentrations than did simvastatin. HDL-cholesterol concentrations increased in both groups. Both drugs were equally well tolerated., Interpretation: Our results show that aggressive LDL-cholesterol reduction by atorvastatin was accompanied by regression of carotid intima media thickness in patients with familial hypercholesterolaemia, whereas conventional LDL lowering was not.

It is unknown whether the variation in severity of cardiovascular disease (CVD), seen in patients with familial hypercholesterolemia (FH), is reflected in the intima-media thickness (IMT) of carotid and femoral arteries. We measured IMT in both these arteries in 248 consecutive patients with FH, attending our Lipid Clinic. One hundred and six patients were classified as having CVD, while the remaining FH subjects had no clinical evidence of CVD. IMT measurements of 20 prespecified carotid and femoral arterial wall segments of the FH groups with and without CVD were compared. All IMTs in both groups were severely thickened with respect to normal controls. Furthermore, the highest IMTs and the largest absolute differences were observed in the common femoral artery (1.23 +/- 0.46 mm vs 1.10 +/- 0.51 mm; P = 0.006). In subjects with CVD, the distributions of IMT within tertiles for both arterial segments were opposite to those found in FH patients without CVD, (P < 0.05, for both segments). The mean IMT of, in particular, the common femoral artery is thicker in FH individuals with CVD compared with those without. Some FH patients have abnormal IMT of the femoral artery, whereas in others the carotid artery is more affected. Therefore, in FH patients, combined assessment of the carotid and femoral arterial walls provides a more accurate estimation of total atherosclerotic burden in FH.

An increased total plasma homocysteine level is an established risk factor for atherosclerotic vascular disease. The plasma level of homocysteine is influenced by both environmental and genetic factors. An important genetic determinant of plasma homocysteine is a common amino acid dimorphism (Ala222Val) in the methylenetetrahydrofolate reductase (MTHFR) gene. Individuals homozygous for the Val allele have significantly higher homocysteine levels than those with an Ala/Val or Ala/Ala genotype. Moreover, the Val/Val genotype has been claimed to be a strong genetic risk factor for atherosclerosis. The aim of the present study is: (1) to determine the risk associated with the MTHFR dimorphism by comparing the genotype distribution in patients with premature atherosclerosis with that in a group of healthy controls; and (2) to investigate the relationship between the MTHFR genotype and parameters of homocysteine metabolism. The patient group consisted of 257 consecutive referred individuals with angiographically proven premature ( <50 years of age) arterial disease (coronary, and/or peripheral vascular disease). A total of 272 healthy hospital workers without a history of vascular disease were selected as a control group. The MTHFR-genotype was determined by PCR and gel-electrophoresis. A methionine-loading test was performed on 245 patients, and, in addition to homocysteine, levels of folate and vitamin B12 were measured. We found a strong correlation between MTHFR genotype and plasma homocysteine levels both before and after methionine loading. In addition, the MTHFR genotype seems important for the inverse relationship between homocysteine and folate and vitamin B12 levels. Lastly, the MTHFR genotype distribution was not different between patient and control groups. MTHFR genotype is a strong determinant of plasma homocysteine levels. Moreover, the plasma level of folate, which by itself influences homocysteine levels, is also dependent on the MTHFR genotype. In Val/Val genotypes, low levels of both folate and B12 lead to a relatively large increase in homocysteine levels. Nevertheless, the MTHFR genotype does not increase the risk for premature coronary artery disease.