Diederik F. van Wijk

Mycophenolate mofetil attenuates plaque inflammation in patients with symptomatic carotid artery stenosis

Atherosclerosis as well as the subsequent progression towards cardiovascular events are considered to, at least partially, be a consequence of chronic inflammatory activity. Therefore, we decided to evaluate the impact of short-term immunosuppressive treatment on plaque characteristics in patients with symptomatic carotid artery stenosis. Twenty-one patients were randomized to receive either 1000 mg. Mycophenolate mofetil (MMF) BD or placebo for at least 2 weeks prior to undergoing carotid endarterectomy (CEA). The serial sections of the CEA specimens were immunostained for activated T-cells (CD3+CD69+), regulatory T-cells (CD3+FOXP3+) and macrophages (CD68). In addition, gene expression profiling was performed by Illumina gene-array. Immunostaining revealed a reduction of activated T-cells in nine MMF-treated patients compared to 11 placebo-treated control patients (19.7% vs. 28.1%; p<0.05) as well as an increase of regulatory T-cells (3.8% vs. 1.8%; p=0.05). Microarray analyses confirmed beneficial changes to plaque phenotype, showing reduced expression of pro-inflammatory genes. Significantly reduced expression of metalloproteinases and osteopontin was observed in three out of nine MMF-treated patients compared to nil out of 11 in the placebo group. In the present study we show that immunosuppressive treatment for two-and-a-half weeks prior to CEA elicits changes in the plaque phenotype of symptomatic patients. These changes include reduced inflammatory cell presence with a concomitant decrease in pro-inflammatory gene expression.

Nonpharmacological Lipoprotein Apheresis Reduces Arterial Inflammation in Familial Hypercholesterolemia

BACKGROUND Patients with familial hypercholesterolemia (FH) are characterized by elevated atherogenic lipoprotein particles, predominantly low-density lipoprotein cholesterol (LDL-C), which is associated with accelerated atherogenesis and increased cardiovascular risk. OBJECTIVES This study used (18)F-fluorodeoxyglucose positron emission tomography ((18)FDG-PET) to investigate whether arterial inflammation is higher in patients with FH and, moreover, whether lipoprotein apheresis attenuates arterial wall inflammation in FH patients. METHODS In total, 38 subjects were recruited: 24 FH patients and 14 normolipidemic controls. All subjects underwent FDG-PET imaging at baseline. Twelve FH patients who met the criteria for lipoprotein apheresis underwent apheresis procedures followed by a second FDG-PET imaging 3 days (range 1 to 4 days) after apheresis. Subsequently, the target-to-background ratio (TBR) of FDG uptake within the arterial wall was assessed. RESULTS In FH patients, the mean arterial TBR was higher compared with healthy controls (2.12 ± 0.27 vs. 1.92 ± 0.19; p = 0.03). A significant correlation was observed between baseline arterial TBR and LDL-C (R = 0.37; p = 0.03) that remained significant after adjusting for statin use (β = 0.001; p = 0.02) and atherosclerosis risk factors (β = 0.001; p = 0.03). LDL-C levels were significantly reduced after lipoprotein apheresis (284 ± 118 mg/dl vs. 127 ± 50 mg/dl; p < 0.001). There was a significant reduction of arterial inflammation after lipoprotein apheresis (TBR: 2.05 ± 0.31 vs. 1.91 ± 0.33; p < 0.02). CONCLUSIONS The arterial wall of FH patients is characterized by increased inflammation, which is markedly reduced after lipoprotein apheresis. This lends support to a causal role of apoprotein B-containing lipoproteins in arterial wall inflammation and supports the concept that lipoprotein-lowering therapies may impart anti-inflammatory effects by reducing atherogenic lipoproteins.

ABCA1 mutation carriers with low high-density lipoprotein cholesterol are characterized by a larger atherosclerotic burden.

AIMS Low HDL-C is a potent risk factor for cardiovascular disease (CVD). Yet, mutations in ABCA1, a major determinant of circulating HDL-C levels, were previously not associated with CVD risk in cohort studies. To study the consequences of low plasma levels of high-density lipoprotein cholesterol (HDL-C) due to ATP-binding cassette transporter A1 (ABCA1) dysfunction for atherosclerotic vascular disease in the carotid arteries. METHODS AND RESULTS We performed 3.0 Tesla magnetic resonance imaging (MRI) measurements of the carotid arteries in 36 carriers of high impact functional ABCA1 mutations and 36 normolipidemic controls. Carriers presented with 42% lower HDL-C levels (P < 0.001), a larger mean wall area (18.6 ± 6.0 vs. 15.8 ± 4.3 mm(2); P = 0.02), a larger mean wall thickness (0.82 ± 0.21 vs. 0.70 ± 0.14 mm; P = 0.005), and a higher normalized wall index (0.37 ± 0.06 vs. 0.33 ± 0.04; P = 0.005) compared with controls, retaining significance after adjustment for smoking, alcohol consumption, systolic blood pressure, diabetes, body mass index, history of CVD, LDL-C, and statin use (P = 0.002). CONCLUSION Carriers of loss of function ABCA1 mutations display a larger atherosclerotic burden compared with age and sex-matched controls, implying a higher risk for CVD. Further studies are needed to elucidate the full function of ABCA1 in the protection against atherosclerosis. These data support the development of strategies to up-regulate ABCA1 in patients with established CVD.

Novel anti-inflammatory strategies in atherosclerosis.

Purpose of review Inflammation has been widely acknowledged to contribute throughout all stages of atherogenesis. However, these recent advances in our understanding have not been translated into clinical practice in which the mainstay of treatment is still lipid-targeted therapy. This review provides an overview of promising anti-inflammatory therapies in atherosclerosis, and discusses potential drawbacks and clinical benefits. Recent findings Immunosuppressive drugs are likely to beneficially affect atherogenesis. Several novel anti-inflammatory targets have been scrutinized, of which some have reached clinical development stage, such as cytokine targets interleukin-1 and interleukin-6, CCR2 antagonist, selective phospholipase, and leukotriene inhibitors. Novel imaging modalities such as MRI and PET-computed tomography provide valuable surrogate inflammatory endpoints for risk stratification and testing anti-inflammatory agents in cardiovascular randomized trials. Summary Anti-inflammatory therapies hold great promise in cardiovascular prevention regimens; however, atherosclerosis is a chronic disease, and systemic long-term use of anti-inflammatory agents carries the risk of complications arising from immunosuppression. In order to successfully add immunosuppressive drugs to our routine armament, we need to identify high-risk patients who benefit from anti-inflammatory treatment, increase our insight into the inflammatory pathogenesis of atherogenesis, and find safe and effective compounds capable of directly suppressing plaque inflammation.

C-Reactive Protein, Fatal and Nonfatal Coronary Artery Disease, Stroke, and Peripheral Artery Disease in the Prospective EPIC-Norfolk Cohort Study

Objective—Circulating levels of C-reactive protein (CRP) are associated with an increased risk of coronary artery disease (CAD), stroke, and peripheral artery disease (PAD). Observational and experimental evidence suggest that CRP might differentially predict fatal and nonfatal cardiovascular events. Here, we sought to determine the predictive value of CRP for fatal and nonfatal CAD, stroke, or PAD. Approach and Results—CRP levels were measured in 18 450 apparently healthy participants in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk cohort. Cox proportional hazards models were used to quantify the association between CRP levels and fatal and nonfatal CAD events, strokes, and PAD events. Bootstrapping was applied to test for significant differences between the risk of fatal and nonfatal events. During 208 485 person-years at risk, 2915 CAD events, 361 strokes, and 657 PAD events occurred. CRP was associated with fatal and nonfatal CAD events and nonfatal PAD events. When adding CRP to predictive risk models for fatal and nonfatal events corrected for known cardiovascular risk factors, the net reclassification index was 2.1% for fatal and 1.9% for nonfatal events. Multivariate adjusted hazard ratios for fatal CAD events (hazard ratio, 1.36; 95% confidence interval, 1.27–1.46) differed significantly (mean difference, 13%; 95% confidence interval, 5.1%–21.9%; P<0.001) from the multivariate adjusted hazard ratio for nonfatal CAD events (hazard ratio, 1.21; 95% confidence interval, 1.15–1.26). Conclusions—In the EPIC-Norfolk cohort, CRP was associated with fatal and nonfatal CAD events, as well as nonfatal PAD events. Adding CRP to risk stratification models resulted in a small improvement in classification for both fatal and nonfatal events. Importantly, CRP was significantly more strongly associated with fatal CAD events than with nonfatal CAD events.

Reconstituted High-Density Lipoprotein Shortens Cardiac Repolarization

OBJECTIVES We hypothesize that increasing high-density lipoprotein cholesterol (HDL-C) shortens cardiac repolarization. BACKGROUND HDL-C is inversely associated with sudden death. The relation between HDL-C and repolarization of the heart is unexplored. METHODS HDL-C was elevated with reconstituted high-density lipoprotein (rHDL). Cardiac repolarization was studied by recording cardiac transmembrane potentials with the patch clamp technique from isolated rabbit cardiomyocytes that were superfused with rHDL. Infusions with rHDL (40 mg/kg body weight) were performed in dyslipidemic patients and healthy volunteers. Electrocardiograms were recorded to assess cardiac repolarization before and 24 h after infusion with rHDL. RESULTS rHDL as well as purified human apolipoprotein AI shortened repolarization of isolated rabbit cardiomyocytes by ∼25% (p < 0.05). rHDL infusion shortened the heart rate-corrected QT interval on surface electrocardiograms in all participants (p < 0.001). CONCLUSIONS rHDL shortens cardiac repolarization. These data provide evidence for a novel mechanism of HDL infusion that may contribute to reduction of sudden cardiac death.

Chemokine Ligand 2 Genetic Variants, Serum Monocyte Chemoattractant Protein-1 Levels, and the Risk of Coronary Artery Disease

Objective—In humans, evidence about the association between levels of monocyte chemoattractant protein-1 (MCP-1), its coding gene chemokine (C-C motif) ligand 2 (CCL2), and risk of coronary artery disease (CAD) is contradictory. Methods and Results—We performed a nested case-control study in the prospective EPIC-Norfolk cohort investigating the relationship between CCL2 single-nucleotide polymorphisms (SNPs), MCP-1 concentrations, and the risk of future CAD. Cases (n=1138) were apparently healthy men and women aged 45 to 79 years who developed fatal or nonfatal CAD during a mean follow-up of 6 years. Controls (n=2237) were matched by age, sex, and enrollment time. Using linear regression analysis no association between CCL2 SNPs and MCP-1 serum concentrations became apparent, nor did we find a significant association between MCP-1 serum levels and risk of future CAD. Finally, Cox regression analysis showed no significant association between CCL2 SNPs and the future CAD risk. In addition, we did not find any robust associations between the CCL2 haplotypes and MCP-1 serum concentration or future CAD risk. Conclusion—Our data do not support previous publications indicating that MCP-1 is involved in the pathogenesis of CAD.

Reduction of monocyte chemoattractant protein 1 and macrophage migration inhibitory factor by a polyphenol-rich extract in subjects with clustered cardiometabolic risk factors.

Inflammation is a hallmark of the metabolic syndrome, which also contributes to a pro-atherogenic state. NF-κB activation, a critical step in regulating inflammatory reactions, can be inhibited by polyphenol (PF) extracts, at least in vitro. In the present study, we set out to study whether a PF-rich extract could attenuate the chronic inflammatory state and/or an acute immune response in vivo in subjects with clustered metabolic risk factors. A commercially available, PF-rich extract (500 mg daily) or placebo was administered for 4 weeks to thirty-four subjects with two or more metabolic risk factors using a randomised, double-blind, cross-over design. During the final study visit, an acute inflammatory challenge (lipopolysaccharide (LPS) 1 ng/kg body weight) was administered to a random subgroup of subjects (PF-rich extract (n 12) and placebo (n 12)). The PF-rich extract modestly reduced the inflammatory chemokines monocyte chemoattractant protein 1 (MCP-1) and macrophage migration inhibitory factor (MIF) (MCP-1 - 6.5 % (PF, median 116 (interquartile range 97-136) pg/ml v. placebo, median 124 (interquartile range 105-153) pg/ml; P < 0.05); MIF - 10.8 % (PF, median 2512 (interquartile range 1898-3972) pg/ml v. placebo, median 2814.5 (interquartile range 2296-3852) pg/ml; P < 0.05); however, other measured markers of inflammation and cardiometabolic disease, such as C-reactive protein, IL-6, HDL-cholesterol, adiponectin and oxidised LDL, remained unaffected. Following the LPS challenge, we found a statistically significant 48 % reduction of MCP-1 production in the PF-rich extract group (n 12) v. placebo (n 12) over 6 h (PF 766 (sd 155) v. placebo 1466 (sd 989) ng/ml; P < 0.05, area under the curve). In conclusion, short-term oral administration of the PF-rich extract caused a modest anti-inflammatory effect in subjects with clustered metabolic risk factors. Further dose-ranging studies are needed to evaluate whether and to what extent PF-rich extracts can be used to reduce the pro-inflammatory state in subjects with metabolic diseases at increased cardiovascular risk.

C-Reactive Protein Identifies Low-Risk Metabolically Healthy Obese Persons: The European Prospective Investigation of Cancer-Norfolk Prospective Population Study.

Background Conflicting data exist about the cardiovascular risk of metabolically healthy obese persons. The prognostic value of C‐reactive protein (CRP) in this intriguing group is unknown. We assessed the association between CRP levels and the risk of coronary heart disease (CHD) in metabolically healthy persons with abdominal obesity. Methods and Results In the European Prospective Investigation of Cancer–Norfolk prospective cohort, CRP levels and information on metabolic syndrome criteria were available for 7279 participants, of whom 825 (11%) developed CHD during a follow‐up period of 10.9±1.8 years. There was a trend toward a higher multivariable‐adjusted hazard ratio for CHD in metabolically healthy obese participants with CRP levels >2 mg/L compared with <2 mg/L (hazard ratio 1.59, 95% CI 0.97–2.62, P=0.066). Metabolically unhealthy obese participants had significantly higher CHD risk compared with metabolically healthy obese participants with CRP levels <2 mg/L (hazard ratio 1.88, 95% CI 1.20–2.94, P=0.006). Most important, we found that the risk of CHD among metabolically healthy obese persons with CRP levels <2 mg/L was comparable to that of metabolically healthy nonobese persons (hazard ratio 0.91, 95% CI 0.60–1.39, P=0.674). Conclusions Among metabolically healthy obese persons, low CRP levels were associated with a CHD risk comparable to that of metabolically healthy nonobese persons. CRP appears to be an easy and widely available method for identifying a low‐risk subpopulation among metabolically healthy obese persons.

Lipid measures and cardiovascular disease prediction

Traditional lipid measures are the cornerstone of risk assessment and treatment goals in cardiovascular prevention. Whereas the association between total, LDL-, HDL-cholesterol and cardiovascular disease risk has been generally acknowledged, the rather poor capacity to distinguish between patients who will and those who will not develop cardiovascular disease has prompted the search for further refinement of these traditional measures. A thorough understanding of lipid metabolism is mandatory to understand recent developments in this area. After a brief overview of lipid metabolism we will discuss the epidemiological data of total, LDL- and HDL-cholesterol and focus on recent advances in measurements of these lipoproteins. In addition we will discuss the role of triglycerides and the apolipoprotein B–A-I ratio on the incidence of cardiovascular disease.