Atherosclerosis

Editorial Board

2012-05-01

Adenosine improves post-procedural coronary flow but not clinical outcomes in patients with acute coronary syndrome: A meta-analysis of randomized trials

2011-12-07

Abstract: Aims: Adjunctive therapy with adenosine has been shown to improve coronary flow in patients with acute coronary syndromes (ACS); it is unclear, however, whether adenosine can effectively reduce adverse clinical events. The aim of our study was to perform a meta-analysis of all randomized controlled trials (RCTs) investigating angiographic and clinical outcomes in ACS patients undergoing PCI or thrombolysis and receiving adjunctive adenosine therapy vs. placebo.Methods: Medline/CENTRAL/EMBASE and Google Scholar database were scanned. The meta-analysis included ten RCTs (N=3821). All-cause mortality was chosen as primary endpoint. Secondary endpoints were re-infarction (MI), heart failure (HF) symptoms (NYHA class III/IV), no-reflow (defined as TIMI 0 flow) and >50% ST-resolution.Results: Adenosine compared to placebo was associated with a significant reduction of post-procedural no-reflow (OR [95% CI]=0.25 [0.08–0.73], p=0.01); however, at a median follow-up of 6 months, prior treatment with adenosine did not confer significant benefits in terms of reduction of mortality (ORFixed [95% CI]=0.87 [0.69–1.09], p=0.23), as well as re-MI (p=0.80), HF symptoms (p=0.44) and ST-resolution (p=0.09). Separate analyses conducted in the subgroups of ST-elevation MI patients treated with either PCI or thrombolysis confirmed the findings found in the overall population.Conclusions: This meta-analysis shows that adenosine adjunctive therapy does not improve survival nor reduce the rates of re-MI and HF symptoms in patients with ACS treated with PCI or thrombolysis. The beneficial effect on post-procedural coronary flow was not associated with consistent advantages on clinical outcomes.

The urokinase system in the pathogenesis of atherosclerosis

Bianca Fuhrman — 2011-12-05

Abstract: Atherogenesis refers to the development of atheromatous plaques in the inner lining of the arteries. These atherosclerotic lesions are characterized by accumulation of monocyte-derived macrophage-foam cells loaded with cholesterol, which eventually undergo apoptotic death, leading finally to formation of the necrotic core of the plaque. Atheroma formation also involves the recruitment of smooth muscle cells (SMC) from the media into the intima, where they proliferate and form the neointima in a process called “remodeling”. Cells in the advanced atherosclerotic plaques express high levels of the serine protease urokinase-type plasminogen activator (uPA) and its receptor (uPAR). uPA is a multi-functional multi-domain protein that is not only a regulator of fibrinolysis, but it is also associated with several acute and chronic pathologic conditions. uPA mediate the extracellular matrix (ECM) degradation, and plays a pivotal role in cell adhesion, migration and proliferation, during tissue remodeling. On cell surface uPA binds to the high affinity urokinase receptor, providing a strictly localized proteolysis of ECM proteins. The uPA/uPAR complex also activates intracellular signaling, thus regulating cellular function. An imbalance in the uPA/uPAR system leads to dis-orders in tissue structure and function. This review summarizes recent progress in understanding the role and mechanisms of the uPA/uPAR system in atherogenesis.

Statins as a possible cause of inflammatory and necrotizing myopathies

Santosh Padala, Paul D. Thompson — 2011-12-12

Abstract: Background: Hydroxy-methyl-glutaryl Co-A reductase (HMGCR) inhibitors or statins are a well recognized cause of a variety of skeletal myopathic effects which generally resolve on stopping the medication. Recent reports, however, suggest that statins are associated with a unique autoimmune myopathy wherein symptoms persist or even progress after statin discontinuation and require immunosuppressive therapy. We performed a systematic review to examine the association of statins with inflammatory (dermatomyositis/polymyositis) and necrotizing myopathies.Methods: We searched PubMed, Ovid and Scopus for English language articles addressing statin associated inflammatory and necrotizing myopathies. Given the paucity of cases, we extended the search to include articles in all languages.Results: The search yielded 14 articles reporting a possible association of statins with inflammatory myopathies describing 10 cases of polymyositis and 14 cases of dermatomyositis, and 4 articles reporting a possible association of statins with necrotizing myopathies describing 63 cases. One study identified a unique antibody directed against HMGCR in patients with necrotizing myopathy. Systemic immunosuppressive therapy was required in majority of these cases for resolution of symptoms.Conclusion: Statins have recently been associated with a variety of inflammatory myopathies including polymyositis, dermatomyositis, and a necrotizing myopathy. The association of statins with necrotizing myopathy is strengthened by the discovery that the serum of some of these patients contains an anti-HMGCR antibody. This suggests that statins can cause or unmask an immune mediated myopathy.

The growing interest of fibrin imaging in atherosclerosis

Gisèle Clofent-Sanchez, Marie-Josée Jacobin-Valat, Jeanny Laroche-Traineau — 2012-03-06

Atherosclerosis is a systemic, chronic and progressive inflammatory disease that is characterised by the build-up of lipid-rich plaques within the walls of large arteries. Atherosclerotic lesions (atheroma) consist not only of lipids but also of cells, connective-tissue elements, and debris. Atherosclerosis is a disease involving endothelial dysfunction, oxidative stress, immunity, inflammation, and thrombosis . The current opinion is that atherosclerosis is an immune/inflammatory response of the intima to endothelial injury initiated by blood flow shear stress typical in increased blood pressure, chronic inflammation or hyperlipidaemia, leading to lipid accumulation and transport of oxidized low-density lipoprotein (Ox-LDL) across the endothelium . Another important initial event is platelet interaction with the dysfunctional endothelium in a well-controlled process involving selectins and integrins which trigger monocyte and lymphocyte recruitment . Monocytes further differentiate into activated macrophages expressing scavenger receptors which then bind different forms of OxLDL . These lipid-laden foam cells are the main components of the early stages of atheroma. Thereafter, as the process continues, other blood cells, including B and T cells involved in adaptive immunity as well as platelets may play important roles in the self-perpetuating inflammatory process of atherosclerosis. The pathogenic immune/inflammatory response may then convert early atheroma to more advanced lipid-rich plaques with necrotic core enlargement . The stability and vulnerability of lipid-rich plaques are mainly determined by the overlying fibromuscular cap composed of smooth muscle cells and extracellular matrix . Thinning and rupture of the cap underlie the majority of cardiovascular diseases, including acute coronary syndromes and stroke, with the formation and release of thrombi that may ultimately occlude vessels.

Endogenous hyperinsulinaemia and exogenous insulin: A common theme between atherosclerosis, increased cancer risk and other morbidities

Sarah E. Holden, Craig J. Currie — 2012-03-05

Insulin is the oldest treatment for hyperglycaemia, and its value in type 1 diabetes is indisputable. However, although the goal of reducing microvascular and macrovascular complications remains the same, type 2 diabetes differs from type 1 diabetes as it is characterised by insulin resistance. Yet despite its high prevalence with approximately 311 million people suffering from type 2 diabetes worldwide , there are no straightforward randomised controlled trials (RCTs) comparing insulin to alternative oral drugs in type 2 diabetes. However, even without the evidence of direct head-to-head comparisons from randomised trials, it has been estimated that the volume of insulin prescribed to patients with type 2 diabetes has doubled from 2000 to 2009 . Furthermore, the ADA and EASD currently support the early initiation of insulin when escalation of treatment is necessary in order to maintain the recommended levels of glycaemic control (HbA1c<7%) . Considering the number of people affected by type 2 diabetes and the expense of insulin, any concern surrounding the safety of insulin in type 2 diabetes could represent a major public health issue.

Dual effects of statins therapy in systemic lupus erythematosus and SLE-related atherosclerosis: The potential role for regulatory T cells

2012-03-14

Abstract: Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease associated with accelerated atherosclerosis independent of traditional risk factors. Statins, the 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase inhibitors, have been widely prescribed for hyperlipidemia, which could slow the atherosclerosis progression, and reduce cardiovascular disease events. Nonetheless, accumulated evidences suggested that statins exert immunomodulatory and anti-inflammatory functions independent of their lipid-lowering effects. By the virtue of pleiotropic immunomodulatory property, statins may be applied for the treatment of both autoimmunity and atherosclerosis in patients with SLE. Interestingly, it has been well documented that regulatory T cells (Tregs) are involved in the pathogenesis of SLE as well as atherosclerosis. Meanwhile, studies have shown that statins could induce augmented number of Tregs with increased functional inhibitory properties. Thus, we hypothesized that the effect of statins ameliorating lupus disease manifestations and lupus-mediated atherogenesis might be mediated, at least partly, via the activation of Tregs.To our knowledge, this is the first hypothesis focused on that Tregs might be involved in the immunomodulatory effect of statins on SLE and SLE-related atherosclerosis.

Leonurine protects against tumor necrosis factor-α-mediated inflammation in human umbilical vein endothelial cells

Xinhua Liu, Lilong Pan, Xianli Wang, Qihai Gong, Yi Zhun Zhu — 2012-02-13

Abstract: Objective: Leonurine, a bioactive alkaloid compound in Herba leonuri, has various pharmacological activities, including antioxidant and anti-apoptotic capacities. This study was conducted to test the hypothesis that leonurine was able to attenuate tumor necrosis factor (TNF)-α-induced human umbilical vein endothelial cells (HUVEC) activation and the underlying molecular mechanisms.Methods: Mitogen-activated protein kinases (MAPK) activation, nuclear factor-κB (NF-κB) activation, and inflammatory mediators expression were detected by Western blot or enzyme-liked immunosorbent assay, intracellular reactive oxygen species (ROS) and NF-κB p65 translocation were measured by immunofluorescence, endothelial cell–monocyte interaction was detected by microscope.Results: Leonurine inhibited U937 cells adhesion to TNF-α-activated HUVEC in a concentration dependent manner. Treatment with leonurine blocked TNF-α-induced mRNA and protein expression of adhesion molecules (intercellular adhesion molecule-1 and vascular cell adhesion molecule-1), cyclooxygenase-2, and monocyte chemoattractant protein-1 in endothelial cells. In addition, leonurine attenuated TNF-α-induced intracellular ROS production in HUVEC. Furthermore, leonurine also suppressed the TNF-α-activated p38 phosphorylation and IκBα degradation. Subsequently, reduced NF-κB p65 phosphorylation, nuclear translocation, and DNA-binding activity were also observed.Conclusions: Our results demonstrated for the first time that the anti-inflammatory properties of leonurine in endothelial cells, at least in part, through suppression of NF-κB activation, which may have a potential therapeutic use for inflammatory vascular diseases.

In vivo assessment of intraplaque and endothelial fibrin in ApoE−/− mice by molecular MRI

2012-01-30

Highlights: ► A fibrin-targeted contrast agent (FTCA) allows in vivo imaging of atherosclerosis. ► Late stage plaques show the strongest signal enhancement after FTCA administration. ► FTCA enables the assessment of response to therapy.Abstract: Objective: Molecular magnetic resonance imaging (MRI) has emerged as a promising non-invasive modality to characterize atherosclerotic vessel wall changes on a morphological and molecular level. Intraplaque and endothelial fibrin has recently been recognized to play an important role in the progression of atherosclerosis. This study aimed to investigate the feasibility of intraplaque and endothelial fibrin detection using a fibrin-targeted contrast-agent, FTCA (EPIX Pharmaceuticals, Lexington, MA), in a mouse model of atherosclerosis.Methods: Male apolipoproteinE-knockout mice (ApoE−/−) were fed a high fat diet (HFD) for one to three months. MRI of the brachiocephalic artery was performed prior to and 90min after the administration of FTCA (n=8 per group). Contrast to noise ratios (CNR) and longitudinal relaxation rates (R1) of plaques were determined and compared to ex vivo fibrin density measurements on immunohistological sections stained with a fibrin-specific antibody and gadolinium concentrations measured by inductively coupled mass spectroscopy (ICP-MS).Results: Molecular MRI after FTCA administration demonstrated a significant increase (p<0.05) in contrast agent uptake in brachiocephalic artery plaques. In vivo CNR measurements were in good agreement with ex vivo fibrin density measurements on immunohistochemistry (y=2.4x+11.3, R2=0.82) and ICP-MS (y=0.95x+7.1, R2=0.70). Late stage atherosclerotic plaques displayed the strongest increase in CNR, R1, ex vivo fibrin staining and gadolinium concentration (p<0.05).Conclusion: This study demonstrated the feasibility of intraplaque and endothelial fibrin imaging using FTCA. Direct in vivo fibrin detection and quantification could be useful for characterization and staging of coronary and carotid atherosclerotic lesions, which may aid diagnosis and intervention.

Coptisine exert cardioprotective effect through anti-oxidative and inhibition of RhoA/Rho kinase pathway on isoproterenol-induced myocardial infarction in rats

2012-03-05

Highlights: ► Using isoproterenol induced myocardial infarction rat models to elucidate the effect of coptisine and investigate its potential mechanism. ► Coptisine has strong antioxidant activity. ► Coptisine significantly inhibit RhoA/ROCK expression induced by isoproterenol.Abstract: Objective: Because myocardial infarction is a major cause of morbidity and mortality worldwide, protecting the heart from the ischemia is the focus of intense research. Coptisine is an isoquinoline alkaloid extracted form Coptidis Rhizoma. This study aims to elucidate if coptisine is responsible for cardioprotection using myocardial infarction (MI) rat models and investigate its potential mechanism of action.Methods: Myocardial infarction was produced in rats with 85mgkg−1 isoproterenol administered subcutaneously twice at an interval of 24h. The rats were randomized into 7 groups: (I) Normal; (II) ISO; (III) ISO+fasudil; (IV) ISO+isosorbide dinitrate (ISDN) and (V–VII) ISO+coptisine (25, 50 and 100mgkg−1). Cardiac function and markers of cardiac ischemic were assessed after MI.Results: Rats pretreated with coptisine (25, 50 and 100mgkg−1) for 21 days and received subcutaneously injected with ISO (85mgkg−1) on the 20th and 21st day at an interval of 24h. The results suggested that coptisine has strong antioxidant activity, and it can maintain cell membrane integrity, ameliorate mitochondrial respiratory dysfunction, reduce myocardial cells apoptosis, inhibit RhoA/ROCK expression induced by high-dose isoproterenol administration.Conclusions: Coptisine provided cardioprotection in a model of myocardial infarction, and therefore should be considered as a novel adjunctive therapy for attenuating myocardial damage.

A combination of secondhand cigarette smoke and Chlamydia pneumoniae accelerates atherosclerosis

2012-03-14

Highlights: ► We model the effect on atherosclerosis following exposure to smoke and Chlamydia. ► In combination, the two insults enhance atherosclerosis in ApoE knockout mice. ► They promote inflammation, defective phagocytosis and accrual of apoptotic cells. ► Ultimately, atherosclerotic plaques show advancement in growth and maturation.Abstract: Objective: Secondhand smoke (SS) induces chronic infection of endothelial cells by Chlamydia pneumoniae (Cpn) in vitro. We investigated the in vivo effect on atherosclerosis following exposure to SS and infection with Cpn both independently and in combination in ApoE−/− mice.Methods and results: Plaques were largest in the combined SS+Cpn-exposed mice with 12–57% greater cross-sectional area compared with all other groups (P<0.03). Quantitative RT-PCR (qRT-PCR) from aortic roots revealed a synergistic upregulation of both OX40L (CD134L) and MyD88 in SS+Cpn mice (P<0.05). This upregulation occurred despite decreased numbers of macrophage, dendritic cell, CD4 T cell and smooth-muscle-cell infiltrates as determined by quantitative IHC and qRT-PCR. To elucidate whether enhanced apoptosis correlated with reduced plaque cellularity, area of Tdt-mediated dUTP nick labeling positive (TUNEL+) cells and expression of key bridging molecules necessary for efferocytosis (Mertk, Tgm2, FasL and C1qa) were examined. In SS+Cpn mice, there was an increase of the area of TUNEL+ cells in plaque cores (P<0.001) and a downregulation of efferocytosis gene expression (P<0.05). Systemic expression of cytokines in sera (Luminex) showed no differences between groups, suggesting that focal disease mechanisms within the plaque predominated.Conclusions: The combination of SS exposure and Cpn infection enhanced atherosclerosis more than either variable did independently by activating inflammatory cells and by promoting growth and maturation of lesions via defective phagocytic clearance and accumulation of apoptotic cells.

Increased expression of T cell immunoglobulin- and mucin domain-containing molecule-3 on natural killer cells in atherogenesis

2012-03-05

Highlights: ► Expression of Tim-3 increase on NK cells, but not T cells, in AS patients. ► Augmented expression of Tim-3 on NK cells correlates with risk factors of AS. ► Augmented expression of Tim-3 inhibits NK cells survival in vitro. ► Blockade of Tim-3 protects NK cells from TNF-α-induced cell death. ► Augmented Tim-3 expression on NK cells plays an important role in NK cell loss in atherosclerosis.Abstract: Objective: Atherosclerosis (AS) has many features of a chronic inflammatory disease in which both adaptive and innate immune cells play roles. Increasing evidence has demonstrated the impairment of circulating natural killer (NK) cells in atherosclerosis. However, the mechanisms of this impairment remain unclear. We previously reported the suppression of NK cell functions by T cell immunoglobulin- and mucin domain-containing molecule (Tim)-3. Here, we investigated the expression of Tim-3 on NK cells and assessed its possible roles in NK loss during atherogenesis.Methods and results: Flow cytometry analysis showed increased Tim-3 expression on peripheral NK cells from patients with AS. This increased expression of Tim-3 was significantly related to the levels of serum lipids and inflammation markers, C-reactive protein (CRP) and tumor necrosis factor (TNF)-α, which are risk factors for atherogenesis. We detected decreased peripheral NK cell number in patients with AS. The NK cell number showed significant inverse correlations with Tim-3 expression levels on NK cells and the level of serum TNF-α. Consistently, Tim-3 overexpression reduced NK92 cell number. Blockade of Tim-3 protected NK92 cells from TNF-α-induced cell death. Similar results were obtained with peripheral NK cells from patients with AS.Conclusions: To the best of our knowledge, for the first time, the data from our study provide evidence that augmented Tim-3 expression on NK cells plays an important role in NK cell loss in atherosclerosis. The augmented Tim-3 expression on NK cells might be used as an indicator for disease progression.

Lysophosphatidic acid causes endothelial dysfunction in porcine coronary arteries and human coronary artery endothelial cells

2012-03-19

Highlights: ► Lysophosphatidic acid reduces endothelium-dependent vasorelaxation in porcine coronary arteries. ► Lysophosphatidic acid decreases the expression of endothelial nitric oxide synthase in both porcine coronary arteries and human coronary artery endothelial cells. ► Lysophosphatidic acid increases oxidative stress in both porcine coronary arteries and human coronary artery endothelial cells.Abstract: Aim: The objective of this study was to determine the effects of lysophosphatidic acid (LPA) on endothelial functions and molecular alternations in both porcine coronary arteries and human coronary artery endothelial cells (HCAECs).Methods and results: The vessel rings and HCAECs were treated with clinically relevant concentrations of LPA for different times. Vasomotor reactivity was studied with a myograph tension system. LPA (10 and 50μM) treatment for the vessel rings significantly reduced endothelium-dependent vasorelaxation in response to bradykinin (×10−5M) by 32% and 49%, respectively, compared with the control (P<0.05). LPA decreased endothelial nitric oxide synthase (eNOS) mRNA and immunoreactivity levels in the vessel rings. In HCAECs, LPA reduced eNOS mRNA, phospho-eNOS and total eNOS protein levels. In addition, superoxide anion levels in LPA-treated vessel rings and HCAECs were significantly increased by lucegenin-enhanced chemiluminescence assay and dihydroethidium staining, respectively. Mitochondrial membrane potential and ATP content in LPA-treated HCAECs were substantially decreased. The mRNA levels of reactive oxygen species generating enzymes NOX4 and p40phox were increased, while endogenous antioxidant enzyme superoxide dismutase 1 was decreased in response to LPA treatment in HCAECs. Furthermore, exogenous antioxidant molecule selenomethionine (SeMet) effectively reversed these LPA-induced effects in both porcine coronary arteries and HCAECs.Conclusions: LPA causes endothelial dysfunction by a mechanism associated with decreased eNOS expression and increased oxidative stress in porcine coronary arteries and HCAECs.

Enhancer of polycomb1 lessens neointima formation by potentiation of myocardin-induced smooth muscle differentiation

2012-03-09

Highlights: ► Enhancer of polycomb1 (Epc1) attenuates VSMC proliferation. ► Epc1 induces VSMC differentiation. ► Epc1 interact with myocardin to activate smooth muscle 22α promoter activity. ► Epc1 gene delivery reduces neointima formation induced by balloon injury.Abstract: Objective: Previously, we reported that enhancer of polycomb1 (Epc1) induces skeletal muscle differentiation through the serum response factor (SRF). Considering that SRF plays a critical role in vascular smooth muscle cell (VSMC) differentiation, we expected that Epc1 also works in VSMCs. Here we examined the effect of Epc1 on neointima formation after arterial balloon injury and the underlying mechanism.Methods: Epc1 expression was examined in carotid artery injury or VSMC models. Interaction with myocardin (Myocd), a master regulator of smooth muscle differentiation, was examined by immunoprecipitation or promoter analysis with smooth muscle (SM) 22α promoter. Finally, we investigated whether local delivery of Epc1 regulated neointimal formation after injury.Results: Epc1 expression was down-regulated during proliferation induced by platelet-derived growth factor BB, whereas it was upregulated during differentiation in VSMCs. Forced expression of Epc1 induced VSMC differentiation. Epc1 physically interacted with Myocd to synergistically activate SM22α promoter activity. Transient transfection of Epc1 enhanced the physical interaction between Myocd and SRF, whereas that interaction was reduced when A10 cells were treated with siRNA for Epc1. Local delivery of Epc1 significantly reduced neointima formation induced by balloon injury.Conclusions: Our results indicate that Epc1 induces VSMC differentiation by interacting with Myocd to induce SRF-dependent smooth muscle genes. We propose that Epc1 acts as a novel negative regulator of neointima formation after carotid injury.

Paraoxonase1 deficiency in mice is associated with hypotension and increased levels of 5,6-epoxyeicosatrienoic acid

2012-02-27

Highlights: ► Studying the role of PON1 in blood pressure (BP) regulation, using paraoxonase1 knockout (PON1KO) mice. ► Reduced BP observed in PON1KO is RAAS- and NO-independent. ► A direct, causal relation between PON1 and BP was observed. ► BP is inversely related to 5,6-EET which is regulated by PON1. ► Endothelial-derived hyperpolarization-like response is probably involved in the reduced BP in PON1KO mice.Abstract: Aim: Serum paraoxonase 1 (PON1) is an HDL-associated lipolactonase and its association with hypertension is controversial. We studied the possible role of PON1 in blood pressure (BP) regulation, by using PON1 knockout (PON1KO) mice.Methods and results: Both, systolic and diastolic BPs were lower in PON1KO compared to WT mice. Hypotension detected in PON1KO is probably neither related to nitric oxide/guanylate cyclase-mediated vasodilation nor to angiotensin II or aldosterone-mediated vasoconstriction. Surprisingly, when challenged by high-salt diet, BP was further reduced in PON1KO mice. The later, pointed to a possible involvement of transient receptor potential vanilloid 4 (TRPV4), and indeed, administration of ruthenium red, a TRPV4 blocker, resulted in a sharp rise in BP. The protein levels of TRPV4 in kidneys of PON1KO were not higher than in WT. However, the renal level of 5,6-epoxyeicosatrienoic acid (5,6-EET), a TRPV4 specific agonist, was significantly higher in PON1KO compared with WT mice. 5,6-EET levels were further elevated under high-salt diet or administration of arachidonic acid. Injection of inhibitor of CYP450 epoxygenase resulted in increased BP in PON1KO mice. Injection of recombinant human PON1 resulted in elevation of BP and a concomitant reduction in renal content of 5,6-EET. PON1, in vitro, metabolized 5,6-EET, but not other EETs, to its corresponding diol. Vasodilation, blocked by excess of dietary K+ but not reversed by depletion of cellular Ca2+ stores, point to endothelial-derived hyperpolarization-like response.Conclusion: The present study shows causal, direct relationship between PON1 and blood pressure which is mediated, at least in part, by the regulation of 5,6-EET.

Effect of an oral astaxanthin prodrug (CDX-085) on lipoprotein levels and progression of atherosclerosis in LDLR−/− and ApoE−/− mice

2012-03-14

Highlights: ► Oxidative stress and inflammation are key promoters of atherosclerosis and myocardial damage. ► The xanthophyll antioxidant protects LDL from oxidation and reduces primary thrombosis. ► Astaxanthin prodrug CDX-085 is significantly more bioavailable than pure astaxanthin. ► CDX-085 prodrug reduces plasma lipoprotein levels. ► CDX-085 reduces progression of atherosclerosis in LDLR−/− mice.Abstract: Oxidative stress and inflammation are key promoters of atherosclerosis and myocardial damage. When orally administered, the novel astaxanthin prodrug CDX-085 delivers high levels of the xanthophyll antioxidant astaxanthin that protects LDL from oxidation and reduces primary thrombosis. In this study, we analyzed whether delivery of astaxanthin from administration of the CDX-085 prodrug reduces plasma lipoprotein levels and the progression of atherosclerosis in low-density lipoprotein receptor negative (LDLR−/−) and apolipoprotein E deficient (ApoE−/−) mice.Methods: Relative circulating levels of astaxanthin derived from CDX-085 administration compared to administration of pure astaxanthin was initially evaluated in a canine model. In mouse Study #1, 16 wild-type and 16 LDLR−/− mice on 0.5% cholesterol diet supplemented with either 0.0%, 0.08%, 0.2% and 0.4% CDX-085 were used to assess plasma levels and lipoprotein biodistribution measured by FPLC after 4 weeks treatment. In Study #2, 36 male LDLR−/− mice were randomized to a 0.5% cholesterol chow diet (CHOW group, n=12) or 0.5% cholesterol chow fortified with 0.08% CDX-085 (n=12) or 0.5% cholesterol chow with 0.4% CDX-085 (n=12) for 12 weeks. In Study #3, 34 male ApoE−/− mice were randomized in the same fashion as the Study #2 and fed similar diets for 9 weeks.Results: CDX-085 administration was shown to result in significantly higher levels of circulating astaxanthin (p<0.001 ANOVA) over a 72h period compared to pure, non-esterified astaxanthin in a single-dose pharmacokinetic study in beagles. In Study #1, plasma astaxanthin levels were 5–9-fold higher in LDLR−/− mice compared to wild-type mice. Astaxanthin was highly distributed among all lipoprotein fractions, generally reflecting cholesterol content of lipoproteins. In Study #2, administration of CDX-085 resulted in significantly lower total cholesterol levels (528±68mg/dL vs. 550±67mg/dL vs. 602±80mg/dL, p=0.047) and aortic arch atherosclerosis (9.0±4.2% vs. 9.8±3.5% vs. 13.2±3.6%, p=0.023) in the 0.4% CDX-085 group compared to the 0.08% CDX-085 and CHOW groups, respectively. In ApoE−/− mice, a 72% reduction in triglycerides in the 0.4% CDX-085 group and 50% reduction in the 0.08% CDX-085 groups was noted compared to CHOW group (final levels 17±11mg/dL vs. 30±15mg/dL vs. 60±32mg/dL, respectively, p=0.001).Conclusion: Oral administration of the novel astaxanthin prodrug CDX-085 shows that it distributes among lipoproteins. CDX-085 lowers total cholesterol and aortic arch atherosclerosis in LDLR−/− mice and triglyceride levels in ApoE−/− mice and shows promise for further evaluation in human studies.

Characteristics of earlier atherosclerotic involvement in adolescent patients with Kawasaki disease and coronary artery lesions: Significance of gray scale median on B-mode ultrasound

2012-02-29

Abstract: Objective: To test the hypothesis that textural changes in the carotid intima–media complex (IMC) detected by B-mode ultrasound are associated with the difference of remodeling process in earlier atherosclerotic involvement in patients with Kawasaki disease (KD) and coronary artery lesions (CALs).Methods: Eighteen patients with KD and CALs (mean age 17.2 years), 17 patients with heterozygous familial hypercholesterolemia (FH) (mean age 16.9 years) and 15 age-matched healthy controls (Cont) were assessed and compared for carotid intima–media thickness (CIMT), elastic property (Ep), and first- and second-order statistics.Results: KD showed significantly higher gray scale median (GSM) than FH and Cont. KD and FH showed significantly higher CIMT, entropy and lower angular second moment than Cont, but no significant difference was found between KD and FH.Conclusion: Higher GSM in KD may indicate alteration of tissue components and heterogeneity of IMC, suggesting the development of arteriosclerotic vascular remodeling after vasculitis. This is distinct from that of atherosclerosis with lower GSM often observed in FH.

Electrocardiographic abnormalities improve classification of coronary heart disease risk in women: Tehran Lipid and Glucose Study

2012-03-02

Highlights: ► We examined the added value of ECG abnormalities in risk stratification for coronary heart disease beyond the Framingham risk score. ► Among women, only in intermediate risk group, the ECG abnormalities were independently associated with increased risk of developing coronary heart disease. ► Addition of the ECG abnormalities to the Framingham risk improved the classification of coronary heart disease risk, especially among intermediate risk group.Abstract: Objectives: To examine the added value of electrocardiogram (ECG) abnormalities beyond the Framingham risk score (FRS) in risk stratification for coronary heart disease (CHD) in a population of Middle Eastern women.Methods: The study population consisted of 2568 women aged ≥30 years, free from CHD symptoms and with no major Q or QS wave or complete left-bundle branch block in their baseline ECG. ECG abnormalities included ST depression (Minnesota codes 4.1–4.2), or T-wave items (Minnesota codes 5.1–5.2). Participants were categorized into 3 groups, according to their FRS. Cox regression analysis was used to estimate the hazard ratios (HR) of CHD events for ECG abnormalities among each FRS group. Net Reclassification Index (NRI) was used as the measure of predictive ability added to the FRS by ECG abnormalities.Results: During 9.3 years, 127 CHD events occurred. In the FRS adjusted analysis, the HRs (95%CI) of CHD events were 3.69 (0.87–15.68), 3.82 (2.01–7.23) and 1.39 (0.47–4.16) for ECG abnormalities in each FRS category (i.e. 0–4.9%, 5–19.9 and ≥20%, respectively). Addition of ECG abnormalities to FRS did not significantly increase the C-statistics (0.838), but improved the predictive ability of the FRS by 20.8 (95% CIs 5.0–38.9) using the cut point free NRI.Conclusion: Among women, only in the intermediate risk group, ECG abnormalities were independently associated with increased risk of developing CHD. Addition of the ECG abnormalities to the FRS improved the classification of coronary heart disease risk, especially in this group.

High-sensitive Troponin I in acute cardiac conditions: Implications of baseline and sequential measurements for diagnosis of myocardial infarction

2012-03-09

Highlights: ► Baseline and sequential hsTnI was assessed in patients with acute cardiac condition and catheterization. ► hsTnI is a sensitive, albeit unspecific marker of myocardial infarction. ► Relevant elevations of hsTnI also occur in patients with non-ischemic cardiac disease. ► Serial assessment and higher cutpoints increase sensitivity/specificity of hsTnI for NSTEMI. ► A clinical algorithm and concentration intervals for hsTnI are proposed which improve predictive values of hsTnI.Abstract: Background: High-sensitive Troponin I (hsTnI) facilitates the early diagnosis of myocardial infarction (MI). However, since hsTnI has not been well characterized in non-ischemic cardiac conditions, the predictive value of hsTnI for MI remains unclear.Methods: hsTnI (ADVIA Centaur, Siemens) on admission was analyzed in 929 patients with acute cardiac condition and invasive ascertainment of coronary status by catheterization.Results: Hs-TnI upon presentation was higher in patients with STEMI (median 1.27ng/mL, IQR 0.13–14.5ng/mL) as compared to patients with Non-STEMI (0.66ng/mL, IQR 0.10–4.0ng/mL, p<0.001) whereas it did not differ from STEMI in Tako-Tsubo cardiomyopathy (2.57ng/mL, IQR 0.17–8.4ng/mL) and myocarditis (9.76ng/mL, IQR 2.0–27.0ng/mL). In patients with resuscitation of non-ischemic cause (0.31ng/mL, IQR 0.06–1.3ng/mL), acute heart failure (0.088ng/mL, IQR 0.035–0.30ng/mL) and hypertensive emergency (0.066ng/mL, IQR 0.032–0.34ng/mL), hs-TnI was elevated above the recommended threshold of 0.04ng/mL. At this cutpoint of 0.04ng/mL, hsTnI indicated acute MI (STEMI or Non-STEMI) with a sensitivity of 88% and a specificity of 45% (ROC–AUC 0.748). When patients with STEMI were excluded, hsTnI indicated Non-STEMI with a sensitivity of 87% and a specificity of 45% (ROC–AUC 0.725). When sequential measurements were taken into account in a restricted cohort, a maximum hsTnI of ≥0.40ng/mL provided a sensitivity of 89% and a specificity of 85% (ROC–AUC 0.909) for Non-STEMI.Conclusions: HsTnI is a sensitive, albeit unspecific marker of MI. In patients with mildly elevated hsTnI and without evidence for STEMI, we suggest serial assessment of hsTnI and a 10-fold higher cutpoint of 0.40ng/mL before Non-STEMI is assumed.

Prognostic value of reverse left ventricular remodeling after primary angioplasty for STEMI

2012-03-16

Highlights: ► Reverse left ventricular remodeling after STEMI has not been fully evaluated. ► Reverse LV remodeling occurred in 49% of STEMI when primary PCI is systematically applied. ► Reverse LV remodeling is expression of effective myocardial salvage by primary PCI. ► Reverse LV remodeling is an important predictor of favorable long-term outcome.Abstract: Aims: Thus far, the prognostic value of reverse left ventricular (LV) remodeling after ST-elevation acute myocardial infarction (STEMI) has not been fully evaluated. We sought to investigate the incidence, major determinants, and long-term clinical significance of reverse LV remodeling in a large series of STEMI patients successfully treated with primary percutaneous coronary intervention (P-PCI).Methods and results: Serial complete 2D-echocardiograms were obtained within 24h after P-PCI, and at 1 and 6 months in 512 consecutive reperfused STEMI patients. Reverse remodeling was defined as a reduction >10% in LV end-systolic volume (LVESV) at 6 month follow-up. Reverse LV remodeling occurred in 49% of study population. At follow-up (41.6±23 months), late heart failure (HF) rate was significantly higher among patients without reverse LV remodeling as compared with those with it (32% vs. 11%, P<0.0001). At multivariate analysis, independent predictors of reverse LV remodeling were a small infarct size measured as peak creatine kinase value (P<0.0001), a small functional myocardial damage measured as wall motion score index within the infarct zone (P=0.018) and baseline LVESV (P<0.0001). After adjustment for several clinical, echographic and angiographic variables, Cox analysis identified reverse LV remodeling as the only beneficial independent predictor of long-term heart failure-free survival (HR: 0.44, 95% CI: 0.275–0.722).Conclusions: Reverse LV remodeling occurred in half of successfully reperfused STEMI patients. Small structural and functional myocardial damages within the infarct zone are the major determinants of reverse LV remodeling. As expression of effective myocardial salvage by P-PCI, the reverse remodeling is an important predictor of favorable long-term outcome.

Association of pericardial fat and coronary high-risk lesions as determined by cardiac CT

2012-03-14

Highlights: ► Pericardial fat is associated with coronary high-risk lesions by cardiac CT. ► Association is statistically independent of traditional risk factors including BMI. ► Pericardial fat discriminates between patients with and without high-risk lesions.Abstract: Objective: Pericardial adipose tissue (PAT) is a pathogenic fat depot associated with coronary atherosclerosis and cardiovascular events. We hypothesized that higher PAT is associated with coronary high-risk lesions as determined by cardiac CT.Methods: We included 358 patients (38% female; median age 51 years) who were admitted to the ED with acute chest pain and underwent 64-slice CT angiography. The cardiac CT data sets were assessed for presence and morphology of CAD and PAT. Coronary high-risk lesions were defined as >50% luminal narrowing and at least two of the following characteristics: positive remodeling, low-density plaque, and spotty calcification. PAT was defined as any pixel with CT attenuation of −190 to −30HU within the pericardial sac.Results: Based on cardiac CT, 50% of the patients (n=180) had no CAD, 46% (n=165) had CAD without high-risk lesions, and 13 patients had CAD with high-risk lesions. The median PAT in patients with high-risk lesions was significantly higher compared to patients without high-risk lesions and without any CAD (151.9 [109.0–179.4]cm3 vs. 110.0 [81.5–137.4]cm3, vs. 74.8 [58.2–111.7]cm3, respectively p=0.04 and p<0.0001). These differences remained significant after adjusting for traditional risk factors including BMI (all p<0.05). The area under the ROC curve for the identification of high-risk lesions was 0.756 in a logistic regression model with PAT as a continuous predictor.Conclusion: PAT volume is nearly twice as high in patients with high-risk coronary lesions as compared to those without CAD. PAT volume is significantly associated with high risk coronary lesion morphology independent of clinical characteristics and general obesity.

The 9p21 genetic variant is additive to carotid intima media thickness and plaque in improving coronary heart disease risk prediction in white participants of the Atherosclerosis Risk in Communities (ARIC) Study

2012-02-20

Highlights: ► CIMT/plaque and 9p21 SNP are known to be associated with CHD. ► CIMT/plaque and 9p21 SNP can improve CHD risk prediction. ► We now show that combining CIMT/plaque, 9p21 further marginally improves CHD risk prediction. ► Improvements in CHD risk prediction conferred by adding CIMT/plaque were greater than 9p21.Abstract: Objective: We evaluated whether the addition of carotid intima media thickness and plaque (CIMT-P), and a single nucleotide polymorphism on chromosome 9p21 (9p21) together improve coronary heart disease (CHD) risk prediction in the ARIC study.Methods: Ten year CHD risk was estimated using the ARIC coronary risk score (ACRS) alone and in combination with CIMT-P and 9p21 individually and together in White participants (n=9338). Area under the receiver operating characteristic curve (AUC), model calibration, net reclassification index (NRI), integrated discrimination index (IDI) and number of individuals reclassified were estimated.Results: The AUC of the ACRS, ACRS+9p21, ACRS+CIMT-P and ACRS+CIMT-P+9p21 models were 0.748, 0.751, 0.763 and 0.766 respectively. The percentage of individuals reclassified, model calibration, NRI and IDI improved when CIMT-P and 9p21 were added to the ACRS only model (see manuscript).Conclusion: Addition of 9p21 allele information to CIMT-P minimally improves CHD risk prediction in whites in the ARIC study.

Genetic determinants of the ankle-brachial index: A meta-analysis of a cardiovascular candidate gene 50K SNP panel in the candidate gene association resource (CARe) consortium

2012-02-23

Highlights: ► Examined association of genetic variants with ankle brachial index (ABI). ► Studies were ethnically diverse, African-American and European ancestry. ► Variants in TCF7L2 and SYTL3 associated with ABI in European ancestry participants. ► However, the associations failed replication in further studies. ► New and more powerful approaches to PAD gene discovery are sorely needed.Abstract: Background: Candidate gene association studies for peripheral artery disease (PAD), including subclinical disease assessed with the ankle-brachial index (ABI), have been limited by the modest number of genes examined. We conducted a two stage meta-analysis of ∼50,000 SNPs across ∼2100 candidate genes to identify genetic variants for ABI.Methods and results: We studied subjects of European ancestry from 8 studies (n=21,547, 55% women, mean age 44–73 years) and African American ancestry from 5 studies (n=7267, 60% women, mean age 41–73 years) involved in the candidate gene association resource (CARe) consortium. In each ethnic group, additive genetic models were used (with each additional copy of the minor allele corresponding to the given beta) to test each SNP for association with continuous ABI (excluding ABI>1.40) and PAD (defined as ABI<0.90) using linear or logistic regression with adjustment for known PAD risk factors and population stratification. We then conducted a fixed-effects inverse-variance weighted meta-analyses considering a p<2×10−6 to denote statistical significance.Results: In the European ancestry discovery meta-analyses, rs2171209 in SYTL3 (β=−0.007, p=6.02×10−7) and rs290481 in TCF7L2 (β=−0.008, p=7.01×10−7) were significantly associated with ABI. None of the SNP associations for PAD were significant, though a SNP in CYP2B6 (p=4.99×10−5) was among the strongest associations. These 3 genes are linked to key PAD risk factors (lipoprotein(a), type 2 diabetes, and smoking behavior, respectively). We sought replication in 6 population-based and 3 clinical samples (n=15,440) for rs290481 and rs2171209. However, in the replication stage (rs2171209, p=0.75; rs290481, p=0.19) and in the combined discovery and replication analysis the SNP–ABI associations were no longer significant (rs2171209, p=1.14×10−3; rs290481, p=8.88×10−5). In African Americans, none of the SNP associations for ABI or PAD achieved an experiment-wide level of significance.Conclusions: Genetic determinants of ABI and PAD remain elusive. Follow-up of these preliminary findings may uncover important biology given the known gene-risk factor associations. New and more powerful approaches to PAD gene discovery are warranted.

Lack of association between connexin40 polymorphisms and coronary artery disease

2012-03-09

Highlights: ► Human Cx40 is expressed under its promoter A in endothelial cells. ► Cx40 promoter A polymorphisms are not associated with coronary artery disease. ► Reduction of Cx40 expression by half may not be sufficient to promote atherosclerosis.Abstract: Objective: Cx40 is a gap junction protein important for cell-cell communication in the endothelium. Polymorphisms in the promoter region of the human Cx40 gene, −44G>A and +71A>G, were shown to reduce Cx40 transcription by half. As mice with an endothelial-specific deletion of Cx40 are more susceptible to atherosclerosis, this study was designed to discover a correlation between these polymorphisms and atherosclerosis in European populations.Methods and results: 803 patients referred to the Geneva University Hospitals for elective coronary angiography were divided according to the number of significantly stenosed vessels (from 0 to 3) and were genotyped for the Cx40 polymorphisms. Genotype distribution in the control group was −44GG/+71AA=59.8%, −44AG/+71AG=35.1% and −44AA/+71GG=5.2%. Surprisingly, this distribution was similar in the CAD group, with −44GG/+71AA=58.5%, −44AG/+71AG=37.6% and −44AA/+71GG=3.8% (p=0.67). Moreover, no significant association between histological carotid plaque composition of culprit lesions and Cx40 polymorphisms could be detected in 583 Dutch patients of the Athero-Express study.Conclusions: Despite a clear antiatherogenic role of Cx40 in mice, our study could not detect an association of Cx40 promoter polymorphisms and CAD in human. Moreover, a correlation with atherosclerotic plaque stability or hypertension could not be demonstrated either. Connexin polymorphisms affecting channel function may be of greater importance for cardiovascular disease than polymorphisms affecting the expression level of the protein.

Identification of genes affecting apolipoprotein B secretion following siRNA-mediated gene knockdown in primary human hepatocytes

2012-03-09

Highlights: ► siRNA-mediated gene knockdown in primary human hepatocytes was used to identify potential causal genes affecting lipid traits. ► Approximately 100 GWAS loci significantly affecting human plasma lipid levels were identified. ► A total of 191 genes from 74 loci were selected and subjected to siRNA-mediated gene knockdown. ► Four genes (PARP10, HP, FUT1, and LPAR2) were identified and verified as affecting ApoB secretion.Abstract: Objective: Genome-wide association studies (GWAS) are useful in studying the complex pathways underlying diseases such as atherosclerosis; however, additional testing is often necessary to identify the disease causal genes linked to GWAS loci. We used siRNA-mediated gene knockdown in primary human hepatocytes (PHuH) to identify potential GWAS causal genes affecting the hepatic secretion of apolipoprotein B (ApoB), ApoA1, and proprotein convertase subtilisin/kexin type 9.Materials and methods: Candidate causal genes within GWAS loci affecting human plasma levels of total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglycerides were identified from the literature; 191 genes were selected from 74 loci. A functional siRNA screen was performed using PHuH.Results: Four genes: poly (ADP-ribose) polymerases member 10, haptoglobin, fucosyltransferase 1, and lysophosphatidic acid receptor 2 were identified and confirmed. Knocking down these genes reduced cell-associated and secreted ApoB levels.Conclusion: Modification of these four genes may affect plasma lipids through modulation of ApoB secretion.

Effect of mutations in LDLR and PCSK9 genes on phenotypic variability in Tunisian familial hypercholesterolemia patients

2012-03-14

Highlights: ► Phenotypic expression in Tunisian familial hypercholesterolemia varied widely. ► We identified a new putative loss of function mutation in PCSK9 gene: p.P174S. ► Variants of PCSK9 and APOE genes explain a part of the phenotypic variability.Abstract: Background: Autosomal dominant hypercholesterolemia (ADH) is commonly caused by mutations in the low-density lipoprotein (LDL) receptor gene (LDLR), in the apolipoprotein B-100 gene (APOB), or in the proprotein convertase subtilisin kexine 9 gene (PCSK9). ADH subjects carrying a mutation in LDLR present highly variable plasma LDL-cholesterol (LDL-C). This variability might be due to environmental factors or the effect of some modifying genes such as PCSK9 and APOE.Aims: We investigated the molecular basis of thirteen Tunisian ADH families and attempted to determine the impact of PCSK9 and APOE gene variations on LDL-cholesterol levels and on the variable phenotypic expression of the disease.Methods and results: Fifty six subjects were screened for mutations in the LDLR gene through direct sequencing. The causative mutation was found to segregate with the disease in each family and a new frameshift mutation, p.Met767CysfsX21, was identified in one family. The distribution of total- and LDL-cholesterol levels, adjusted for age and gender, among homozygous and heterozygous ADH patients varied widely. Within seven families, nine subjects presented low LDL-cholesterol levels despite carrying a mutation in the LDLR gene. To identify the molecular actors underlying this phenotypic variability, the PCSK9 gene was screened using direct sequencing and/or enzymatic restriction analysis, and the apo E genotypes were determined. A new missense variation (p.Pro174Ser) in the PCSK9 gene was identified and characterized as a new putative loss-of-function mutation.Conclusion: Genetic variations in PCSK9 and APOE genes could explain only part of the variability observed in the phenotypic expression in Tunisian ADH patients carrying mutations in the LDLR gene. Other genetic variants and environmental factors very probably act to fully explain this phenotypic variability.

Vitamin D dependent effects of APOA5 polymorphisms on HDL cholesterol

2012-03-19

Highlights: ► A 25OHD receptor binding site modifying APOA5 promoter polymorphism was associated with lower HDL-C in 25OHD deficient individuals. ► Stronger interactions in subsamples evaluated in winter months suggest effects may be meaningful only at deficient levels of vitamin D. ► Gene–environment interactions with modifiable environmental components suggest potential strategies to improve cardiovascular risk.Abstract: Objectives: Vitamin D and serum lipid levels are risk factors for cardiovascular disease. We sought to determine if vitamin D (25OHD) interacts at established lipid loci potentially explaining additional variance in lipids.Methods: 1060 individuals from Utah families were used to screen 14 loci for SNPs potentially interacting with dietary 25OHD on lipid levels. Identified putative interactions were evaluated for (1) greater effect size in subsamples with winter measures, (2) replication in an independent sample, and (3) lack of gene–environment interaction for other correlated dietary factors. Maximum likelihood models were used to evaluate interactions. The replicate sample consisted of 2890 individuals from the Family Heart Study. Putative 25OHD receptor binding site modifying SNPs were identified and allele-specific, 25OHD-dependent APOA5 promoter activity examined using luciferase expression assays. An additional sample with serum 25OHD measures was analyzed.Results: An rs3135506–25OHD interaction influencing HDL-C was identified. The rs3135506 minor allele was more strongly associated with low HDL-C in individuals with low winter dietary 25OHD in initial and replicate samples (p=0.0003 Utah, p=0.002 Family Heart); correlated dietary factors did not explain the interaction. SNP rs10750097 was identified as a putative causative polymorphism, was associated with 25OHD-dependent changes in APOA5 promoter activity in HEP3B and HEK293 cells (p<0.01), and showed similar interactions to rs3135506 in family cohorts. Linear interactions were not significant in samples with serum 25OHD measures; however, genotype-specific differences were seen at deficient 25OHD levels.Conclusions: A 25OHD receptor binding site modifying APOA5 promoter polymorphism is associated with lower HDL-C in 25OHD deficient individuals.

Genetic predisposition to coronary heart disease and stroke using an additive genetic risk score: A population-based study in Greece

2012-03-19

Highlights: ► We constructed a genetic risk score based on 9 “CHD-specific” SNPs from GWAS. ► We examined whether this genetic risk score (GRS) predicts incident CHD and stroke. ► We have used resources generated in the Greek-EPIC cohort. ► The GRS was significantly associated with the incidence of CHD. ► This GRS was not found to be statistically significantly associated with incident stroke.Abstract: Objective: To determine the extent to which the risk for incident coronary heart disease (CHD) increases in relation to a genetic risk score (GRS) that additively integrates the influence of high-risk alleles in nine documented single nucleotide polymorphisms (SNPs) for CHD, and to examine whether this GRS also predicts incident stroke.Methods: Genotypes at nine CHD-relevant SNPs were determined in 494 cases of incident CHD, 320 cases of incident stroke and 1345 unaffected controls drawn from the population-based Greek component of the European Prospective Investigation into Cancer and nutrition (EPIC) cohort. An additive GRS was calculated for each study participant by adding one unit for the presence of each high-risk allele multiplied by the estimated effect size of that allele in the discovery samples. Statistical analysis was performed using logistic regression.Results: The GRS was significantly associated with the incidence of CHD where the odds of CHD incidence in the highest quintile of the GRS were 1.74 times higher (95% confidence interval [CI]=1.25–2.43, p for trend=0.0004), compared to the lowest quintile. With respect to stroke, a weaker and non-significant positive association with GRS was apparent as the odds of stroke incidence in the highest quintile of the GRS were 1.36 times higher (95% CI=0.90–2.06, p for trend=0.188), compared to the lowest quintile.Conclusion: A GRS relying on nine documented “CHD-specific” SNPs is significantly predictive of CHD but it was not found to be statistically significantly associated with incident stroke.

Genetic and environmental influences on total plasma homocysteine and its role in coronary artery disease risk

2012-03-19

Highlights: ► Hyperhomocysteinemia is associated with increased risk of overall stenosis in the Lebanese population. ► Hyperhomocysteinemia increases the risk of mild and severe occlusion in major arteries. ► Hyperhomocysteinemia and hypertension are highly correlated suggesting that hyperhomocysteinemia acts as a hypertensive agent leading to CAD. ► Diuretics and genetic polymorphisms in MTHFR and SLCO1B1 are associated with hyperhomocysteinemia.Abstract: Background: Elevated levels of total plasma homocysteine are a risk factor for atherosclerotic disease.Aims: The rationale behind this study is to explore the correlation between degree and site of coronary lesion and hyperhomocysteinemia in Lebanese CAD patients and assess environmental and genetic factors for elevated levels of total plasma homocysteine.Methods: A total of 2644 patients were analyzed for traditional CAD risk factors. Logistic regression was performed to determine the association of hyperhomocysteinemia with degree and site of coronary lesions controlling for risk factors. Environmental and genetic factors for hyperhomocysteinemia were analyzed by logistic regression using a candidate gene approach.Results: Traditional risk factors were correlated with stenosis. Hyperhomocysteinemia associated with increased risk of overall stenosis, and risk of mild and severe occlusion in major arteries. Hyperhomocysteinemia and hypertension were highly correlated suggesting that hyperhomocysteinemia acts as a hypertensive agent leading to CAD. Diuretics and genetic polymorphisms in MTHFR and SLCO1B1 were associated with hyperhomocysteinemia.Conclusions: Hyperhomocysteinemia is a medical indicator of specific vessel stenosis in the Lebanese population. Hypertension is a major link between hyperhomocysteinemia and CAD occurrence. Genetic polymorphisms and diuretics’ intake explain partly elevated homocysteine levels. This study has important implications in CAD risk prediction.

Single polymorphism nucleotide rs1333049 on chromosome 9p21 is associated with carotid plaques but not with common carotid intima-media thickness in older adults. A combined analysis of the Three-City and the EVA studies

2012-03-22

Highlights: ► We studied the link between rs1333049 and subclinical atherosclerosis in older adults. ► Carotid plaques and intima-media thickness were assessed by ultrasound examination. ► Common carotid intima-media thickness was precisely measured at a plaque-free site. ► The C allele of rs1333049 was associated with carotid plaques. ► Rs1333049 genotype was not associated with carotid intima-media thickness.Abstract: Objectives: To address the relationship of rs1333049, the 9p21 variant showing the strongest association with coronary heart disease (CHD), with carotid plaques and plaque-free common carotid artery intima-media thickness (CCA-IMT) in older adults from 2 French population-based cohorts.Methods: We genotyped for rs1333049, 4097 CHD-free participants including 3191 aged 65–86 years from the Three-City (3C) Study and 906 aged 59–71 years from the Vascular Aging Study (EVA). Plaque-free mean CCA-IMT and the presence of carotid plaques were assessed.Results: In multivariate analysis, each C allele copy of rs1333049 was associated with baseline carotid plaques (odds ratio (OR)=1.24; 95% confidence interval (CI)=1.13–1.36; p<0.001) but not with baseline CCA-IMT (p=0.19). Among the EVA participants, the C allele was associated with 4-year plaques progression (p=0.04) but not with CCA-IMT progression.Conclusion: The chromosome 9p21 locus might influence CHD risk through carotid plaques development.

Coronary plaque rupture in patients with myocardial infarction after noncardiac surgery: Frequent and dangerous

2012-03-14

Highlights: ► Nearly 50% of patients with acute coronary syndromes (ACS) after noncardiac surgery have evidence of coronary plaque rupture. ► The only independent predictor of plaque rupture in coronary angiography was having the diagnosis of ACS. ► ACS after non-cardiac surgery and spontaneous ACS have similar pathophysiology.Abstract: Purpose: The pathophysiology of acute coronary syndromes (ACS) after noncardiac surgery is not established yet. Thrombosis over a vulnerable plaque or decreased oxygen supply secondary to anemia or hypotension may be involved. The purpose of this study was to investigate the pathophysiology of ACS complicating noncardiac surgery.Methods: Clinical and angiographic data were prospectively recorded into a database for 120 consecutive patients that had an ACS after noncardiac surgery (PACS), for 120 patients with spontaneous ACS (SACS), and 240 patients with stable coronary artery disease (CAD). Coronary lesions with obstructions greater than 50% were classified based on two criteria: Ambrose's classification and complex morphology. The presence of Ambrose's type II or complex lesions were compared between the three groups.Results: We analyzed 1470 lesions in 480 patients. In PACS group, 45% of patients had Ambrose's type II lesions vs. 56.7% in SACS group and 16.4% in stable CAD group (P<0.001). Both PACS and SACS patients had more complex lesions than patients in stable CAD group (56.7% vs. 79.2% vs. 31.8%, respectively; P<0.001). Overall, the independent predictors of plaque rupture were being in the group PACS (P<0.001, OR 2.86; CI, 1.82–4.52 for complex lesions and P<0.001, OR 3.43; CI, 2.1–5.6 for Ambrose's type II lesions) or SACS (P<0.001, OR 8.71; CI, 5.15–14.73 for complex lesions and P<0.001, OR 5.99; CI, 3.66–9.81 for Ambrose's type II lesions).Conclusions: Nearly 50% of patients with perioperative ACS have evidence of coronary plaque rupture, characterizing a type 1 myocardial infarction.

Periodontitis and diabetes associations with measures of atherosclerosis and CHD

2012-03-22

Highlights: ► Severe periodontal disease and diabetes is associated with increased prevalence of IMT≥1, acoustic shadowing, and CHD. ► Diabetes alone is associated with increased odds for IMT>1mm, but not shadowing or CHD. ► Periodontal disease increases the likelihood of subclinical atherosclerotic heart disease and CHD in diabetic patients. ► There is a need case definitions of periodontal disease that effectively capture systemic effects of sever forms of the disease. ► Further investigation is warranted to understand the interaction of diabetes and periodontal disease as it relates to increased prevalence of IMT, acoustic shadowing, and CHD.Abstract: Objective: Diabetes has been linked with more severe periodontal disease and with coronary heart disease (CHD). The purpose of this study was to determine if periodontal infection was a significant modifier in the risk that diabetes poses for increased carotid artery intimal–medial wall thickness (IMT) and more advanced atheroma lesions as reflected in atherosclerotic plaque calcification measured by acoustic shadowing.Methods and results: Comparisons for analyses of cardiovascular outcomes were performed based upon periodontitis and diabetes status. Periodontitis was measured using pocket depth and attachment loss at six sites per tooth. Cross-sectional data on 6048 persons aged 52–74 years were obtained from the Dental Atherosclerosis Risk in Communities Study. Participants without diabetes (n=5257) were compared to those with diabetes (n=791). Dependent variables were thick IMT (>1mm), presence of acoustic shadowing, and prevalent CHD. All models were adjusted for the following covariates: gender, age, race/center, LDL and HDL cholesterol, BMI, triglycerides, hypertension, smoking, income and education. For multivariate model building, all non-normally distributed variables were transformed and multivariable logistic regression analyses were performed to evaluate the relationship between periodontal infection, diabetes, and cardiovascular outcomes. Individuals with diabetes and with severe periodontitis were found to be significantly more likely to have IMT>1mm [OR=2.2, (1.4–3.5)], acoustic shadowing [OR=2.5, (1.3–4.6)], and CHD [OR=2.6, (1.6–4.2)] compared to those without diabetes or periodontal disease.Conclusion: Results from this study suggest that among people with diabetes, periodontal disease may increase the likelihood of subclinical atherosclerotic heart disease and CHD.

Correlates of endothelial function and the peak systolic blood pressure response to a graded maximal exercise test

2012-02-13

Highlights: ► BAR % change from baseline at 1min, fasting blood glucose, NOS3 −786 T>C, baseline NO, and age explain 24.1% of the peak SBP response to a GEST. ► Carriers of the NOS3 C minor/risk allele had an 11.1±5.0mmHg higher peak SBP response to a GEST than men with the NOS3 TT genotype. ► Clinical and biochemical markers and a genetic variant associated with impaired endothelial function appear to explain a clinically significant portion of the GEST peak SBP response.Abstract: Purpose: An elevated systolic blood pressure (SBP) response to a graded maximal exercise stress test (GEST) may be a predictor of endothelial dysfunction and hypertension. We examined relationships among the GEST peak SBP response and indicators of endothelial function.Methods: Men (n=48, 43.7±1.4yr) with high BP (145.1±1.5/85.5±1.1mmHg) completed a GEST. Peak SBP was the highest SBP achieved during the GEST. Blood samples were taken for fasting glucose and insulin, nitric oxide (NO), and DNA. Endothelial nitric oxide synthase (NOS3, rs2070744) −786 T>C genotyping was determined by PCR. NOS3 genotypes were combined using a dominant model [TT (n=24); TC/CC (n=24)]. Brachial artery reactivity (BAR) was determined via ultrasound before, 1min, and 3min post occlusion and calculated as % change. Analysis of variance (ANOVA) tested changes in the peak SBP GEST response by NOS3 genotype. Multiple variable regression analyses examined relationships among the GEST peak SBP response and measures of endothelial function.Results: %BAR change at 1min (r2=0.093, p=0.020), glucose (r2=0.062, p=0.014), NOS3 −786 T>C (r2=0.040, p=0.024), NO (r2=0.037, p=0.064), and age (r2=0.009, p=0.014) explained 24.1% of the GEST peak SBP response (p=0.043). The GEST peak SBP change from baseline was 11.1±5.0mmHg higher among those with the NOS3 C allele (92.4mmHg+3.8) than the NOS3 TT genotype (81.3mmHg+3.2) (p=0.03).Conclusion: Indicators of endothelial function appear to explain a clinically significant portion of the GEST peak SBP response. Further investigation is needed to unravel the mechanisms by which endothelial function influences the GEST peak SBP response.

Endothelial insulin receptor expression in human atherosclerotic plaques: Linking micro- and macrovascular disease in diabetes?

2012-02-16

Highlights: ► Insulin enhances capillary-like tube formation of human microvascular endothelial cells. ► Insulin receptors are highly expressed on endothelial cells of nascent microvessels within human atherosclerotic plaques. ► Type 2 diabetic patients who use insulin tend to have higher intra-plaque microvessel density than patients using oral glucose lowering agents. ► Together, these results imply that insulin may stimulate local angiogenesis within atherosclerotic plaques.Abstract: Objective: Exogenous insulin use in patients with type 2 diabetes (DM2) has been associated with an increased risk of cardiovascular events. Through which mechanisms insulin may increase atherosclerotic plaque vulnerability is currently unclear. Because insulin has been suggested to promote angiogenesis in diabetic retinopathy and tumors, we hypothesized that insulin enhances intra-plaque angiogenesis.Methods: An in vitro model of pathological angiogenesis was used to assess the potential of insulin to enhance capillary-like tube formation of human microvascular endothelial cells (hMVEC) into a three dimensional fibrin matrix. In addition, insulin receptor expression within atherosclerotic plaques was visualized in carotid endarterectomy specimens of 20 patients with carotid artery stenosis, using immunohistochemical techniques. Furthermore, microvessel density within atherosclerotic plaques was compared between 68 DM2 patients who received insulin therapy and 97 DM2 patients who had been treated with oral glucose lowering agents only.Results: Insulin, at a concentration of 10−8M, increased capillary-like tube formation of hMVEC 1.7-fold (p<0.01). Within human atherosclerotic plaques, we observed a specific distribution pattern for the insulin receptor: insulin receptor expression was consistently higher on the endothelial lining of small nascent microvessels compared to more mature microvessels. There was a trend towards an increased microvessel density by 20% in atherosclerotic plaques derived from patients using insulin compared to plaques derived from patients using oral glucose lowering agents only (p=0.05).Conclusion: Exogenous insulin use in DM2 patients may contribute to increased plaque vulnerability by stimulating local angiogenesis within atherosclerotic plaques.

NT-proBNP is associated with fibulin-1 in Africans: The SAfrEIC study

2012-02-20

Highlights: ► We explored NT-proBNP and fibulin-1 in Africans and Caucasians. ► A positive relationship exists between NT-proBNP and fibulin-1 in African men. ► This association remains independent of age, blood pressure and kidney function. ► Our results suggest possible early vascular changes present in this population. ► This was confirmed in younger African men, increasing their risk for cardiac damage.Abstract: Objectives: The N-terminal prohormone B-type natriuretic peptide (NT-proBNP) is involved in the regulation of volume load and secreted when systemic cardiac overload occurs. Fibulin-1 on the other hand is a component of many extracellular matrix proteins including those present in atherosclerotic lesions, expressed in elastin-containing fibres of blood vessels, and also in the heart. Due to an alarming prevalence of hypertensive heart disease in black South Africans, we investigated the associations of NT-proBNP with fibulin-1 and markers of arterial stiffness in Africans and Caucasians.Methods: We included 231 Africans and 238 Caucasians from South Africa aged 22–77 years. Serum NT-proBNP and fibulin-1 levels were determined, and arterial compliance and pulse wave velocity were measured.Results: Africans had significantly higher blood pressure and NT-proBNP levels than Caucasians and African men had higher fibulin-1 levels than Caucasian men. In single regression analysis, NT-proBNP was significantly associated with fibulin-1 in African men and Caucasian women. NT-proBNP correlated negatively with arterial compliance in all groups except Caucasian women. After partial adjustments, the association between NT-proBNP and fibulin-1 strengthened in African men only. After full adjustment in multiple regression analysis, the association of NT-proBNP with fibulin-1 was confirmed in African men (R2=0.41; β=0.26; p<0.01) and also in younger women (R2=0.34; β=0.251; p=0.012).Conclusions: Only Africans indicated a significant independent association between NT-proBNP and fibulin-1, suggesting that cardiovascular alterations are already present in this relatively young African population as opposed to Caucasians.

Postprandial accumulation of chylomicrons and chylomicron remnants is determined by the clearance capacity

2012-02-27

Highlights: ► Accumulation of lipids in the blood after a meal predicts cardiovascular events. ► We tested the relation between fasting and non-fasting triglycerides levels. ► Secretion of triglycerides did not predict the extent of non-fasting levels. ► Clearance of triglycerides predicted non-fasting concentrations. ► Triglyceride clearance is a common factor determining fasting and non-fasting levels.Abstract: Objective: To better understand the postprandial clearance of triglyceride-rich lipoproteins (TRLs) and its relation to the fasting kinetics of TRLs.Methods: Two studies were performed on 30 male subjects: a fasting kinetic study to determine the fasting secretion and clearance rates of apolipoprotein B (apoB) 100 and triglycerides in the very low-density lipoprotein 1 and 2 (VLDL1 and VLDL2) fractions; and a postprandial study to determine the postprandial accumulation of apoB48, apoB100 and triglycerides in the chylomicron, VLDL1 and VLDL2 fractions. Results from these two studies were combined to characterize the postprandial clearance of TRLs in a physiologically relevant setting.Results: Our results show that postprandial accumulation of the apoB48-carrying chylomicrons can be predicted from the clearance capacity of the lipolytic pathway, determined in the fasting state. Furthermore, we show that chylomicrons and VLDL1 particles are not cleared equally by the lipoprotein lipase pathway, and that chylomicrons seem to be the preferred substrate. Subjects with a rapid fasting lipid metabolism accumulate lower levels of postprandial triglycerides with less accumulation of apoB100 in the VLDL1 fraction and a faster transfer of apoB100 into the VLDL2 fraction. In contrast, fasting VLDL1 secretion does not predict postprandial triglyceride accumulation.Conclusions: Non-fasting triglyceride levels have recently been identified as a major predictor of future cardiovascular events. Here we show that the capacity of the lipolytic pathway is a common determinant of both the fasting and non-fasting triglyceride levels and may thus play an important role in the development of dyslipemia and atherosclerosis.

FABP4 predicts atherogenic dyslipidemia development. The PREDIMED study

2012-03-15

Highlights: ► FABP4 was considered an emerging factor of metabolic risk. ► Individuals with atherogenic dyslipidemia have higher FABP4 plasma concentrations. ► We observed that elevated FABP4 plasma concentrations preceded atherogenic dyslipidemia. ► FABP4 could be considered a risk marker of metabolic derangement. ► FABP4 may predict the development of atherogenic dyslipidemia.Abstract: Objective: Atherogenic dyslipidemia (AD), characterized by high plasma triglycerides and low HDL particles, is considered one of the main effectors of vascular damage associated with obesity, metabolic syndrome (MS) and type 2 diabetes. Adipocyte fatty acid-binding protein (FABP4) plasma concentrations have been linked to metabolic alterations that are associated with adiposity. The aim of the present study was to prospectively analyze the predictive value of baseline FABP4 plasma concentrations for the development of AD.Methods: In the frame of the PREDIMED study, a multicenter dietary interventional trial, we prospectively measured the baseline plasma FABP4 levels and AD incidence over a six-year follow-up period (median 4 [IQR, 3–5years]) in 578 volunteers who visited their general practitioners because of their cardiovascular risk factors.Results: During follow-up, 103 participants developed AD. Baseline plasma FABP4 levels were associated with new onset AD over the follow-up period (OR 1.03 [95% IC: 1.00–1.05], p=0.020). This increased risk was observed in women but not in men. Among women, those in the highest tertile of FABP4 had a 2.54-fold increased relative risk of developing AD compared to the lowest tertile (HR 2.54 [95% CI, 1.31–4.93], p for trend=0.008).Conclusions: Elevated plasma FABP4 concentrations should be considered as a potential marker of metabolic derangement, which may predict the development of AD in women.

Salt intake determines retinal arteriolar structure in treatment resistant hypertension independent of blood pressure

2012-03-05

Highlights: ► We performed in vivo measurements of retinal arteriolars with scanning laser doppler flowmetry in patients with treatment resistant hypertension. ► Wall to lumen ratio, wall thickness and wall cross section area were strongly associated with urinary sodium excretion but not with 24h blood pressure. ► Urinary sodium excretion emerged as the only independent determinant of wall thickness and wall cross section area of retinal arteriolars. ► Salt intake influences the structure of retinal arterioles independent of blood pressure in treatment resistant hypertension.Abstract: Objective: Patients with treatment resistant hypertension are at increased risk of developing cardiovascular end organ damage. The role of sodium in end organ damage is gaining interest and an independent association of sodium and cardiovascular morbidity and mortality has been described.Methods: In an observational study including 40 patients with treatment resistant hypertension, we analysed retinal arteriolar structure in vivo as a determinant of remodelling of small resistant vessels (wall/lumen ratio, wall thickness, wall cross section area) using scanning laser Doppler flowmetry and automatic full-field perfusion imaging analysis. Urinary sodium excretion was determined by 24h urine sample and, in parallel 24h ambulatory blood pressure was measured. We analysed the association of the retinal arterial structure with urinary sodium excretion and blood pressure.Results: Wall to lumen ratio, wall thickness and wall cross section area were strongly associated with urinary sodium excretion but not with 24h blood pressure. In a multiple regression analysis including urinary sodium excretion, BMI, age and 24h blood pressure, urinary sodium excretion emerged as the only independent determinant of wall thickness (β=0.432, p=0.01), and wall cross section area (β=0.439, p=0.008).Conclusion: Our results clearly demonstrate that salt intake influences the structure of retinal arterioles independent of blood pressure in treatment resistant hypertension. Considering the morphologic relation of retinal arteriolar and cerebral vascular structure these results might prove to have important implications on risk stratification in patients with treatment resistant hypertension.

Associations between serum lipoprotein(a) levels and the severity of coronary and aortic atherosclerosis

2012-03-05

Abstract: To elucidate the associations between Lp(a) levels and coronary and aortic atherosclerosis, we performed aortic MRI in 143 patients undergoing coronary angiography. Severity of aortic atherosclerosis was represented as plaque scores. Of the 143 patients, 104 had coronary artery disease (CAD). Thoracic and abdominal aortic plaques were found in 89 and 131 patients. Lp(a) levels increased stepwise with the number of stenotic coronary vessels: 15.7 (CAD(−)), 21.2 (1-vessel), 21.4 (2-vessel), and 22.9mg/dl (3-vessel) (P<0.05). For aortic atherosclerosis, 143 patients were divided into quartiles by plaque scores. Lp(a) did not differ among quartiles of thoracic plaques: 17.1, 19.0, 23.5, and 21.2mg/dl (P=NS), whereas Lp(a) increased stepwise with quartiles of abdominal plaques: 17.1, 19.2, 19.1, and 24.0mg/dl (P<0.05). Lp(a) was an independent factor for CAD and abdominal aortic plaques, but not thoracic plaques. Thus, Lp(a) levels were associated with aortic atherosclerosis, especially in abdominal aorta, as well as coronary atherosclerosis.

Associations between alcohol consumption and selected cytokines in a Swiss population-based sample (CoLaus study)

2012-03-15

Highlights: ► Moderate alcohol consumption is associated with lower levels of interleukin 6 and tumor necrosis factor-α. ► This effect occurs irrespective of the type of alcohol consumed (wine, beer or spirits). ► Conversely, alcohol consumption appears to exert no effect on interleukin-1β levels.Abstract: Objective: To assess the associations between alcohol consumption and cytokine levels (interleukin-1beta – IL-1β; interleukin-6 – IL-6 and tumor necrosis factor-α – TNF-α) in a Caucasian population.Methods: Population sample of 2884 men and 3201 women aged 35–75. Alcohol consumption was categorized as nondrinkers, low (1–6 drinks/week), moderate (7–13/week) and high (14+/week).Results: No difference in IL-1β levels was found between alcohol consumption categories. Low and moderate alcohol consumption led to lower IL-6 levels: median (interquartile range) 1.47 (0.70–3.51), 1.41 (0.70–3.32), 1.42 (0.66–3.19) and 1.70 (0.83–4.39)pg/ml for nondrinkers, low, moderate and high drinkers, respectively, p<0.01, but this association was no longer significant after multivariate adjustment. Compared to nondrinkers, moderate drinkers had the lowest odds (Odds ratio=0.86 (0.71–1.03)) of being in the highest quartile of IL-6, with a significant (p<0.05) quadratic trend. Low and moderate alcohol consumption led to lower TNF-α levels: 2.92 (1.79–4.63), 2.83 (1.84–4.48), 2.82 (1.76–4.34) and 3.15 (1.91–4.73)pg/ml for nondrinkers, low, moderate and high drinkers, respectively, p<0.02, and this difference remained borderline significant (p=0.06) after multivariate adjustment. Moderate drinkers had a lower odds (0.81 [0.68–0.98]) of being in the highest quartile of TNF-α. No specific alcoholic beverage (wine, beer or spirits) effect was found.Conclusions: Moderate alcohol consumption is associated with lower levels of IL-6 and (to a lesser degree) of TNF-α, irrespective of the type of alcohol consumed. No association was found between IL-1β levels and alcohol consumption.

Premature myocardial infarction is associated with low serum levels of Wnt-1

2012-03-05

Highlights: ► Young myocardial infarction patients (≤40years) show decreased Wnt-1 levels. ► Premature CAD patients show elevated levels of the Wnt-1 antagonist Dkk-1. ► Low Wnt-1 levels are associated with features of the metabolic syndrome.Abstract: Objective: Besides its effects on glucose and lipid metabolism, the Wnt pathway has been increasingly implicated in the regulation of proliferation, migration and survival of vascular cells. In addition, defective Wnt signaling has been identified in a family with autosomal dominant early coronary artery disease. The aim of this study was to investigate whether premature coronary artery disease is associated with features of decreased Wnt signaling.Methods and results: We prospectively enrolled 100 consecutive young survivors of myocardial infarction (MI≤40years of age) from two high-volume cardiac catheterization centers and 100 sex and age matched hospital controls. We determined serum levels of Wnt-1 and its antagonist Dkk-1 by ELISA. MI patients showed significantly lower Wnt-1 levels as compared to controls (151ng/mL, IQR 38–473ng/mL vs. 233ng/mL, IQR 62–1756; p<0.005) whereas Dkk-1 was not different at baseline. Wnt-1 levels remained stable over time, whereas Dkk-1 significantly increased at one-year follow-up from 3557, IQR 2306–5810pg/mL to 4973, IQR 3293–7093pg/mL (p<0.001). In the stable phase of the disease, Wnt-1 levels were lower (p<0.005) and Dkk-1 levels were significantly higher (p<0.001) as compared to controls. Wnt-1 at follow-up was associated with glucose, HbA1c, non-HDL-, HDL-cholesterol and triglyceride levels but no other features of the metabolic syndrome.Conclusion: This study establishes an association between low Wnt-1 and high Dkk-1 serum levels and premature myocardial infarction. Wnt-1 is associated with markers of glucose and lipid metabolism. Further research elucidating the role of Wnt pathways in premature coronary artery disease and metabolic syndrome is warranted.

Relation of total and free testosterone and sex hormone-binding globulin with cardiovascular risk factors in men aged 24–45 years. The Cardiovascular Risk in Young Finns Study

2012-03-15

Highlights: ► The study cohort consisted of 24–45-year-old Finnish men. ► We studied the relations of testosterone and SHBG with cardiovascular risk factors. ► Lower levels of testosterone and SHBG are associated with adverse CV risk profile.Abstract: Background: Total and free testosterone decrease gradually in men with advancing age but it is not completely known how lower levels of testosterone are related with various cardiovascular risk factors. We studied the levels of total testosterone, calculated free testosterone and sex hormone-binding globulin (SHBG), and their relations with cardiovascular risk factors in young Finnish men.Methods: The study cohort consisted of 24–45-year-old men participating the Cardiovascular Risk in Young Finns Study in the follow-up surveys performed in 2001 (N=1024) and 2007 (N=991). Levels of total testosterone, SHBG, lipids, glucose, insulin, blood pressure and anthropometric factors were measured and free testosterone was calculated.Results: In multivariable analyses adjusted for age, body mass index and life-style factors (alcohol consumption, smoking and physical activity), total and calculated free testosterone were inversely correlated with triglycerides (both P<0.0001), insulin (P=0.0004 and P=0.01), systolic blood pressure (P=0.007 and P=0.01), and directly with high-density lipoprotein (HDL) cholesterol (P<0.0001 and P=0.003). SHBG was inversely correlated with triglycerides and insulin, and directly with HDL-cholesterol (all P<0.001). In longitudinal analyses, lower levels of testosterone and SHBG were associated with higher levels of triglycerides and insulin six years later (all P<0.01). Baseline level of SHBG was directly associated with HDL-cholesterol (P<0.0001).Conclusion: In young and middle-aged men, higher levels of testosterone and SHBG are associated with favourable cardiovascular risk profile characterized by lower levels of triglycerides, insulin and systolic blood pressure, and higher levels of HDL-cholesterol.

Differential proteomic distribution of TTR (pre-albumin) forms in serum and HDL of patients with high cardiovascular risk

Judit Cubedo, Teresa Padró, Rodrigo Alonso, Juan Cinca, Pedro Mata, Lina Badimon — 2012-03-16

Highlights: ► TTR shows important changes in serum and HDL proteomes of AMI- and FH-patients. ► Inverse relationship between tTTR levels and cardiovascular risk factors after AMI. ► AMI-patients with diabetes and dyslipemia show significant lower tTTR levels. ► The HDL fraction transports the monomeric form of TTR. ► FH-patients with a previous cardiovascular episode have decreased levels of mTTR.Abstract: Inflammation is a common condition contributing to cardiovascular disease progression which leads to clinical manifestations such as acute myocardial infarction (AMI). By applying a proteomic expression profiling approach we have investigated changes in transthyretin (TTR) in AMI-patients and its distribution patterns in HDL samples of patients with high cardiovascular risk, such as those with familiar hypercholesterolemia (FH).Methods and results: The characterization by bidimensional electrophoresis (2-DE), followed by mass-spectrometry (MALDI-TOF) of serum samples revealed changes in the intensity of the TTR spot with a pI of 5.6 and a Mw of 42kDa (tTTR) between AMI-patients in association to diabetic dyslipemia. Serum TTR levels, determined by commercial ELISA, were significantly lower (p<0.0001) in AMI-patients (n=39) and FH-patients (n=100) than in healthy controls (n=60). Western blot and 2-DE analysis showed a differential distribution profile of TTR forms between serum, where 3 TTR forms of 42 (tTTR), 28 (dTTR), and 14kDa (mTTR) were detected, and HDL samples, where only mTTR was present.Conclusions: Our results demonstrate alterations in TTR proteomic profile in relation to the clustering of risk factors which seems to highlight the implication of TTR in cardiovascular risk. The significant differences in TTR between serum (tTTR) and HDL (mTTR) underscore the importance of TTR-forms in the circulation and deserve further investigation to understand their function.

Flavonols intake and the risk of coronary heart disease: a meta-analysis of cohort studies

2012-03-19

Abstract: Objective: Prospective cohort are inconsistent regarding the association between flavonols intake and the risk of coronary heart disease (CHD). The aim was to perform a meta-analysis to determine whether an association exists between them in observational studies.Methods: We searched PUBMED and EMBASE databases for studies conducted from 1966 through January 2012. Data were independently abstracted by 2 investigators using a standardized protocol. Study-specific risk estimates were combined by using a random-effects model.Results: A total of nine general population cohorts with 216,908 participants and more than 5249 CHD cases were included in the meta-analysis. The summary relative risk (RR) did not indicate a significant association between the highest flavonols intake and reduced risk of CHD (summary RR: 0.91; 95% CI: 0.83, 1.01). Furthermore, no significant association was found through the dose-response analysis (an increment of 20mg/day, summary RR: 0.96; 95% CI: 0.90, 1.03).Conclusions: Our results do not support a protective role of flavonols intake against CHD.

Atherosclerosis risk in HIV-infected patients: The influence of hepatitis C virus co-infection

2012-03-14

Abstract: Background: The influence of hepatitis C virus (HCV) infection on atherosclerosis risk in HIV-infected patients has not been adequately evaluated in real-life situations.Objectives and methods: We compared indexes of early atherosclerosis evaluated by echo-Doppler ultrasound (presence of plaque in carotid or femoral arteries) in 18 HCV–HIV co-infected patients versus 22 HIV mono-infected patients.Results: Prevalence of subclinical carotid plaque was significantly higher in HCV–HIV co-infected patients (p=0.04), despite of the fact LDL-cholesterol and blood pressure (BP) were lower in the co-infected patients (p=0.003). HCV chronic infection (OR=10; IC: 1.5–72; p=0.02) was an independent risk factor.Conclusion: This cross sectional study suggests that HCV infection might be an independent cardiovascular risk factor in HCV–HIV co-infected patients. HCV infection might be considered as not only a liver infection but also as a metabolic disease in HIV patients, justifying regular cardiovascular surveillance.

Inverse association between the existence of coronary artery disease and progression of abdominal aortic aneurysm

2012-03-19

Highlights: ► Retrospective cohort study in 665 Japanese patients undergone elective AAA repair was performed. ► An inverse association between the existence of CAD and progression of AAA was identified. ► Preoperative CAD was a significant determinant of the occurrence of cardiac events after elective AAA repair.Abstract: Objectives: A strong degree of co-existence between coronary artery disease (CAD) and abdominal aortic aneurysm (AAA) is widely acknowledged, however, it remains to be elucidated whether the existence of CAD is associated with an accelerated expansion rate of AAA. Also, the relationship between preoperative CAD and postoperative major adverse cardiovascular events (MACE) has not been examined in Japanese patients. The aim of this study was to investigate the deleterious effects of CAD on the progression of AAA and the onset of postoperative MACE after elective AAA repair.Methods and results: A retrospective cohort study of 665 consecutive Japanese patients who underwent elective surgical repair for infrarenal AAA at 2 high-volume Tokyo hospitals from 2003 through 2010 was performed. Preoperative CAD was shown to be a significant determinant of postoperative MACE (HR 2.29; 95%CI, 1.12–4.66; p=0.02). In the analysis of 510 patients for whom there were at least 2 follow-up CT scans of the size of their AAA before repair, the existence of CAD was shown to be inversely associated with the accelerated expansion rate of AAA.Conclusion: This study on the patients undergone elective repair for infrarenal AAA identified an inverse association between the existence of CAD and progression of AAA as well as the significant impact of preoperative CAD on the occurrence of postoperative MACE after elective AAA repair.

High sodium intake adversely affects oxidative-inflammatory response, cardiac remodelling and mortality after myocardial infarction

2012-03-21

Highlights: ► The effect of sodium intake on the outcome after myocardial infarction is unknown. ► High sodium intake favors inflammation and ventricular remodeling. ► High sodium intakers have higher short and long-term mortality after myocardial infarction.Abstract: Objective: Enhanced sodium intake increases volume overload, oxidative stress and production of proinflammatory cytokines. In animal models, increased sodium intake favours ventricular dysfunction after myocardial infarction (MI). The aim of this study was to investigate, in human subjects presenting with ST-segment elevation MI (STEMI), the impact of sodium intake prior the coronary event.Methods: Consecutive patients (n=372) admitted within the first 24h of STEMI were classified by a food intake questionnaire as having a chronic daily intake of sodium higher (HS) or lower (LS) than 1.2g in the last 90 days before MI. Plasma levels of 8-isoprostane, interleucin-2 (IL-2), tumour necrosis factor type α (TNF-α), C-reactive protein (CRP) and brain natriuretic peptide (BNP) were measured at admission and at the fifth day. Magnetic resonance imaging was performed immediately after discharge. Total mortality and recurrence of acute coronary events were investigated over 4 years of follow-up.Results: The decrease of 8-isoprostane was more prominent and the increase of IL-2, TNF-α and CRP less intense during the first 5 days in LS than in HS patients (p<0.05). Sodium intake correlated with change in plasma BNP between admission and fifth day (r=0.46; p<0.0001). End-diastolic volumes of left atrium and left ventricle were greater in HS than in LS patients (p<0.05). In the first 30 days after MI and up to 4 years afterwards, total mortality was higher in HS than in LS patients (p<0.05).Conclusion: Excessive sodium intake increases oxidative stress, inflammatory response, myocardial stretching and dilatation, and short and long-term mortality after STEMI.

High-dose rosiglitazone is pro-atherogenic in cholesterol-fed rabbits

2012-02-29

Rosiglitazone (Avendia) is an agonist of peroxisome proliferator activated receptor gamma (PPARγ) and has been widely used for the treatment of type 2 diabetes in US due to its effect of improving insulin sensitivity . Rosiglitazone can be used alone or in combination with metformin (Avandamet) or with glimepiride (Avandaryl). However, in recent years, several large-scale studies have revealed that treatment with rosiglitazone may increase the risk of cardiovascular disease and acute myocardial infarction although other study failed to demonstrate such side-effects . Regardless of these controversies, concerns have been raised whether rosiglitazone has any roles on the development of atherosclerosis. Until now, many studies have shown that administration of PPARγ agonists inhibits the development of atherosclerosis in both apoE and LDL-receptor knock-out mice . Furthermore, macrophage-specific PPARγ knockout mice increased atherosclerosis, suggesting that PPARγ has an anti-atherogenic role .

Low rate of detection of active cytomegalovirus (CMV) infection early following acute myocardial infarction

2012-03-15

Inflammation plays a crucial role in the development of cardiovascular diseases. Several lines of clinical, epidemiological and experimental evidences suggest a role for cytomegalovirus (CMV), whose pro-inflammatory properties have been consistently documented , in the pathogenesis atherosclerosis, coronary artery restenosis or thrombosis following angioplasty and cardiac allograft vasculopathy . Furthermore, it has been postulated that active CMV infection might be involved in the progression of coronary atherothrombosis and contribute to plaque destabilization, thus precipitating the development of acute myocardial infarction (AMI) . In this context, conflicting data have been published on the incidence of active CMV infection in the clinical setting of acute coronary syndrome . To shed light on this issue, we investigated the incidence of plasma CMV DNAemia early following AMI (within 3 days) by means of a highly sensitive real-time PCR assay.