Association of Growth Differentiation Factor 15 with Arterial Stiffness and Endothelial Function in Subpopulations of Patients with Coronary Artery Disease: A Proof-of-Concept Study.

BACKGROUND: Growth-differentiation factor-15 (GDF-15) is a biomarker belonging to the transforming growth factor-beta cytokine superfamily, which is linked to many pathological conditions, including inflammation and myocardial injury. Pulse wave velocity (cfPWV) and augmentation index (AIx) are indices of arterial stiffness, which are associated with the severity of coronary artery disease (CAD). Flow-mediated dilatation (FMD) is a well-studied surrogate marker of endothelial-dependent dysfunction and systemic inflammation. OBJECTIVE: In this proof-of-concept study, we aimed to investigate the relationship between circulating GDF-15, endothelial dysfunction, and indices of arterial stiffness in different settings of coronary artery disease and myocardial injury. METHODS: In this cross-sectional single-center study, we enrolled patients (n = 22) after interventional treatment for acute myocardial infarction (AMI), patients (n = 11) admitted with chest pain and elevated cardiac enzymes but without evidence of obstructing CAD (MI-NOCAD) in percutaneous coronary angiography (CAG), and patients (n = 20) who underwent CAG according to indications without evident obstructive CAD in CAG (NOCAD). FMD was assessed at the brachial artery. AIx of the central aortic pressure and cfPWV were estimated by applanation tonometry at the radial and carotid-femoral site, respectively, with a validated acquisition system (Sphygmo- Cor, AtCor Medical, Sydney (NSW), Australia). ELISA was used to determine circulating GDF- 15 serum levels (R&D Systems, Minneapolis, MN). Clinical and demographic data and values of routine biochemical biomarkers were obtained. The highest high-sensitive cardiac Troponin I (hsTpnI) value during hospitalization was also recorded. Left ventricular ejection fraction (LVEF) was assessed with a transthoracic echocardiogram. RESULTS: Patients with AMI were older, had worse LVEF, higher values of hsTpnI and increased circulating GDF-15 levels. Importantly, AMI patients had increased cfPWV values, deteriorated AIx values, blunted FMD and worse serum creatinine levels compared to MI-NOCAD and NOCAD patients, respectively, whereas MI-NOCAD and NOCAD did not differ from each other significantly on these biomarkers. Both AMI and MI-NOCAD patients presented a higher but comparable white blood cell count than NOCAD patients. A strong linear correlation between GDF-15 and cfPWV, hsTpnI, AIx, white blood cell count and creatinine but not with FMD was demonstrated in the general study population. CONCLUSION: This proof-of-concept study showed that higher circulating levels of GDF-15, an inflammatory biomarker, were associated significantly with increased arterial stiffness only in AMI patients, whereas elevated GDF-15 demonstrated a linear relationship with the severity of the myocardial injury.

Atrial Fibrillation: Biomarkers Determining Prognosis.

Atrial fibrillation (AF) is a common cardiac arrhythmia known to incite increased thromboembolic and mortality risks, especially among patients not under anticoagulant therapy when indicated. Several routine scores exist to help stratify AF patients, such as the CHAD2DS2-VASc score and upon which physicians are based to decide whether to administer anticoagulant therapy. Being that anticoagulant regimen is a double- edged situation with both benefits and risks, decision-making process demands a definite and reliable, evidence-based set of data to rely on. Blood-based biological elements known as biomarkers are measurable indices that can provide crucial insights concerning not only underlying disease mechanisms but also prognostic and risk stratifying information. As AF is constituted by an overwhelming range of pathophysiological aspects such as inflammation, fibrosis, hypercoagulable states and myocardial damage, identifying and assessing relevant biomarkers will evidently support the clinician's prognostication efforts. The current reviewpresents studied biomarkers with proven prognostic potential in AF as well as possible enhancement of risk-scores when incorporated to them.

Prognostic significance of arterial stiffness and osteoprotegerin in patients with stable coronary artery disease.

BACKGROUND: Arterial stiffness and vascular calcification significantly contribute to coronary atherosclerosis progression. The prognostic value of increased arterial stiffness and vascular calcification in subjects with stable coronary artery disease (CAD) after percutaneous coronary intervention(PCI) is currently under question. MATERIALS AND METHODS: We randomly enrolled 262 patients with stable CAD 1 month after successful PCI. Carotid-femoral pulse wave velocity (PWV) was measured as a well-established index of central aortic stiffness. Osteoprotegerin (OPG) plasma levels were measured as a biomarker of vascular calcification. Patients were followed up prospectively up to 52 months. The primary endpoint was the composite of death from cardiovascular causes, myocardial infarction, stroke or hospitalization for cardiovascular causes. RESULTS: During the follow-up period, 48 patients presented the primary composite endpoint. Subjects who presented the primary endpoint, compared to subjects free of cardiovascular events, had significantly increased PWV (9.45 ± 2.19 m/s vs 8.73 ± 2.07 m/s, P = .04) and OPG levels (4.21 ± 2.19 pmol/L vs 3.18 ± 1.74 pmol/L, P = .003). Survival analysis indicated that PWV predicted adverse cardiac events MACE (Hazard ratio = 1.29 95%CI: 1.07-1.57, P = .008) independently from confounders such as age, sex, smoking habits, ejection fraction, extent of coronary artery disease, hypertension and diabetes mellitus. Interestingly, for every increase in pulse wave velocity by 1 m/s, there is an anticipated increase in the risk of major adverse cardiovascular event (MACE) by 29%. CONCLUSIONS: These findings extend the current knowledge concerning the role of arterial stiffness as powerful biomarkers in cardiovascular disease. Measurement of PWV might have a role in ascertaining prognosis and managing treatment in patients with stable CAD after PCI.

Western Dietary Pattern Is Associated With Severe Coronary Artery Disease.

The independent predictive value of an unhealthy diet on the severity of coronary artery disease (CAD) requires further investigation. We assessed the impact of dietary pattern on CAD severity. In this cohort study, we included 188 symptomatic stable patients with CAD. Patients were categorized as having severe CAD or nonsevere CAD by coronary angiography. Among several demographics and clinical characteristics, all patients were tested using a semiquantitative food frequency questionnaire. Concerning baseline demographic characteristics, there was no difference between patients with severe CAD and nonsevere CAD. Principal component analysis revealed 8 distinct dietary patterns. The first component Western dietary pattern (increased intake of fat, red meat, and carbohydrates and minimal consumption of fruits and green leafy vegetables) was predictive of severe CAD (area under the curve: 0.73, 95% confidence intervals: 0.64-0.83, P < .001). In conclusion, an unhealthy Western type of diet is associated with the severity of coronary artery lesions in patients with stable CAD. These findings highlight the role of dietary patterns when estimating cardiovascular risk for the management of patients with CAD.

Genotyping, Platelet Activation, and Cardiovascular Outcome in Patients after Percutaneous Coronary Intervention: Two Pieces of the Puzzle of Clopidogrel Resistance.

OBJECTIVES: Individual platelet responses to antiplatelet therapy depend on genetic, cellular, and clinical factors. CYP2C19 and P2Y12 receptor polymorphisms are implicated in platelet responses to antiplatelet treatment. We aimed to evaluate the impact of CYP2C19 and C34T P2Y12 genotyping on platelet reactivity and cardiovascular outcome in patients after percutaneous coronary intervention (PCI) on clopidogrel treatment. METHODS: We enrolled 408 patients with stable coronary artery disease (CAD) receiving aspirin and clopidogrel (75 mg/day) 1 month after PCI. High on-treatment platelet reactivity was evaluated using the VerifyNow Assay in a subset of patients. CYP2C19*2 and C34T P2Y12 genotyping was performed by real-time polymerase chain reaction. The primary end point was the composite of death or hospitalization for cardiovascular causes, and patients were followed for a median time of 13 months. RESULTS: In the total study population, 37% were carriers of at least 1 CYP2C19*2 loss-of-function allele, and 53% were carriers of at least 1 C34T loss-of-function allele. Interestingly, homozygotes of the CYP2C19*2 loss-of-function allele had significantly increased P2Y12 reaction units (PRU) (p = 0.007). However, PRU did not differ between carriers and noncarriers of the C34T loss-of-function allele (p = 0.41). Moreover, carriers of CYP2C19*2 had an increased hazard ratio (HR) for the occurrence of the primary end point (for carriers HR = 1.96, 95% CI 1.05-3.66, p = 0.03), whereas the C34T polymorphism had no impact on the cardiovascular outcome (p = 0.17). Finally, PRU was associated with cardiovascular outcome even after adjustment for the presence of any reduced function allele polymorphism. CONCLUSIONS: We documented a different effect of CYP2C19 and P2Y12 receptor polymorphisms on platelet reactivity and cardiovascular outcome in CAD patients after PCI on clopidogrel treatment. Importantly, increased platelet reactivity adversely affects the cardiovascular outcome independently of the studied polymorphisms.

The impact of dietary flavonoid supplementation on smoking-induced inflammatory process and fibrinolytic impairment.

BACKGROUND AND AIMS: Smoking is associated with increased inflammatory process and impairment of fibrinolytic status. Concord grape juice (CGJ), a rich source of flavonoids, can modify cardiovascular risk factors. We aimed to evaluate the impact of CGJ on smoking-induced impairment of inflammatory and fibrinolytic status in healthy smokers. METHODS: We studied the effect of a 2-week oral treatment with CGJ in 26 healthy smokers on three occasions (day 0: baseline, day 7 and day 14) in a randomized, placebo-controlled, double-blind, cross-over design. Measurements were carried out before (pSm) and 20 min after (Sm20) cigarette smoking. Serum levels of intercellular adhesion molecule-1 (sICAM-1) and plasminogen activator inhibitor 1 (PAI-1) were measured as markers of inflammatory and fibrinolytic status, respectively. RESULTS: Treatment with CGJ reduced pSm sICAM-1 levels (p < 0.001), while placebo had no impact on ICAM-1 levels (p = 0.31). Moreover, treatment with CGJ decreased pSm values of PAI-1 (p < 0.001) while placebo had no impact on PAI-1 levels (p = 0.89). Smoking induced an elevation in PAI-1 levels after smoking compared to pro-smoking levels in all study days and in both arms (CGJ and placebo) of the study (p < 0.001 for all). Interestingly, CGJ compared to placebo, attenuated the acute smoking increase in sICAM-1 and PAI-1 levels (p < 0.001 and p = 0.005 respectively). CONCLUSIONS: CGJ consumption improved inflammatory and fibrinolytic status in healthy smokers and attenuated acute smoking induced increase in ICAM-1 and PAI-1 levels. These findings shed further light on the favorable effects of flavonoids in cardiovascular health.

Education status determines 10-year (2002-2012) survival from cardiovascular disease in Athens metropolitan area: the ATTICA study, Greece.

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality worldwide, and educational level seems to be an important determinant of the disease occurrence. The aim of this work was to investigate the association between education status and 10-year incidence of CVD, controlling for various socio-demographic lifestyle and clinical factors. From May 2001 to December 2002, 1514 men and 1528 women (>18 years) without any clinical evidence of CVD or any other chronic disease, at baseline, living in greater Athens area, Greece, were enrolled. In 2011-2012, the 10-year follow-up was performed in 2583 participants (15% of the participants were lost to follow-up). Incidence of fatal or non-fatal CVD was defined according to WHO-ICD-10 criteria. Education status was measured in years of schooling. The 10-year incidence of CVD was 15.7% [95% confidence intervals (CI) 14.1%-17.4%], 19.7% in men and 11.7% in women (Pgender < 0.001). Age-and gender-adjusted analyses revealed that those with low education (<9 years of schooling) were 1.52 times more likely (95% CI 1.03-2.23%) to have CVD compared with those with high education (>12 years of schooling). People in the low education group had higher prevalence of hypertension, diabetes and dyslipidaemias, were more likely to be smokers and sedentary, had less healthy dietary habits, as compared with those in the high education group. When controlling for participants' medical history, smoking, dietary and lifestyle habits, low education was no longer significantly associated with CVD, illustrating the mediating effect of clinical and behavioural factors in the link between education and disease. It was of interest that low education status interacted with alcohol drinking, enhancing the adverse effect of low education on CVD risk (relative risk 1.44, 95% CI 0.94%-2.20%), after various adjustments made. In this study, it was concluded that low educational level was associated with increased CVD risk. This was mainly explained by the intermediate association of low education with unhealthy choices that consequently worsen clinical status.

Effects of CYP2C19 Polymorphism on Endothelial Function, Arterial Stiffness and Inflammation in Coronary Artery Disease Patients Under Clopidogrel Treatment.

BACKGROUND: Clopidogrel's ability to inhibit platelet function determined its clinical usefulness. The role of CYP2C19*2 genotype on antiplatelet treatment is recently under question. Arterial wall properties and inflammation are key players in atherosclerosis development. Hence, we evaluated the impact of CYP2C19*2 genetic polymorphism on endothelial function, arterial stiffness and inflammation in coronary artery disease (CAD) patients receiving clopidogrel treatment. METHODS AND RESULTS: In this study we enrolled 408 consecutive patients with stable CAD under dual antiplatelet therapy (clopidogrel 75mg/day, aspirin 100mg/day), 30 days after percutaneous coronary intervention. Measurement of flow-mediated dilation (FMD) of the brachial artery was used to evaluate endothelial function. Carotid-femoral pulse wave velocity (PWV) and augmentation index (AIx) was measured to estimate arterial stiffness. Real time polymerase chain reaction was used for the genotyping of CYP2C19*2. Levels of tumor necrosis factor alpha (TNF-a) and interleukin 6 (IL-6) were measured with ELISA. We found no difference in basic clinical and demographic characteristics nor in FMD, PWV, AIx and inflammatory status (p=NS for all) between CYP2C19 homozygotes for the wild type; carriers of reduced function allele and homozygotes for the reduced function allele. CONCLUSION: CYP2C19*2 loss of action polymorphism causes no impact on vascular function and inflammatory status in stable CAD patients receiving clopidogrel treatment.

Clopidogrel response variability is associated with endothelial dysfunction in coronary artery disease patients receiving dual antiplatelet therapy.

OBJECTIVES: Dual antiplatelet therapy with aspirin and a platelet P2Y12 ADP receptor antagonist is the cornerstone of treatment following percutaneous coronary intervention (PCI). Several clinical and genetic factors can cause suboptimal clopidogrel response. We examined the impact of endothelial dysfunction on clopidogrel response variability in subjects with stable coronary artery disease (CAD) after PCI. METHODS: We consecutively enrolled 198 patients with stable CAD one month after successful PCI. All patients were receiving dual antiplatelet therapy (clopidogrel 75 mg and aspirin 100 mg/day). Platelet reactivity was measured by VerifyNow P2Y12 assay (Accumetrics, San Diego, CA). VerifyNow reports its results in P2Y12 reaction units (PRU) and the diagnostic cut-off value is 230. Endothelial function was evaluated by flow mediated dilation (FMD). RESULTS: Patients with high on treatment platelet reactivity (32% of the study population), compared to subjects with low on treatment platelet reactivity, presented decreased FMD values (4.35 ± 2.22% vs. 5.74 ± 3.29%, p = 0.01). Moreover, an inverse association between endothelial function measurement and platelet reactivity (r = -0.24, p = 0.001) was found. Importantly, multivariate analysis after adjustment for age, gender and confounders revealed by the univariate analysis (left ventricle ejection fraction, body mass index, diabetes, dyslipidemia, coronary lesion number) showed that for every decrease in FMD by 1% there is an anticipated increased in the odds of patients to have HPR by 1.66 (95% CI 1.03-2.57, p = 0.037). CONCLUSIONS: Endothelial dysfunction is associated with clopidogrel response variability in patients after PCI receiving dual antiplatelet therapy. These findings shed some light on the mechanisms affecting individual platelet response to antiplatelet therapy and may explain the non-straight forward association between clopidogrel dose, platelet inhibition and cardiovascular outcome.

The Role and Predictive Value of Cytokines in Atherosclerosis and Coronary Artery Disease.

Atherosclerosis is currently regarded as a chronic inflammatory disease that is mediated by several types of cells and molecules. Emphasis has been placed on the role of cytokines and the way they act and interact to initiate and sustain inflammation in the microenvironment of an atherosclerotic plaque. Cytokines are invariably expressed by all cells involved in the pathogenesis of atherosclerosis, act on a variety of targets exerting multiple effects and are largely responsible for the crosstalk among endothelial, smooth muscle cells, leukocytes and other vascular residing cells. In the present paper our aim is to review current information on the role of the most commonly discussed cytokines in the process of atherogenesis and to discuss the prognostic significance of these cytokines in atherosclerosis and coronary artery disease.

Novel Inflammatory Biomarkers in Cardiovascular Therapeutics.

Inflammation has been established as an important determinant of cardiovascular disease progression. Currently, clinical examination, laboratory and imaging tests are invaluable for the diagnosis, prognosis and disease monitoring. Novel inflammatory biomarkers are also used to better restratify patients in risk groups but their potential to guide treatment decisions and management of patients has not been extensively evaluated. Therefore, in this review article we present the most recent data concerning the use of inflammatory biomarkers in cardiovascular therapeutics.

High platelet reactivity is associated with vascular function in patients after percutaneous coronary intervention receiving clopidogrel.

BACKGROUND: In the present study, we evaluated the association of platelet reactivity with vascular function in patients after percutaneous coronary intervention receiving clopidogrel treatment. METHODS: We enrolled 150 patients with stable CAD receiving clopidogrel regimen (75 mg/d), 1 month after percutaneous coronary intervention. Carotid-femoral pulse wave velocity (PWV) was measured as an index of aortic stiffness and augmentation index (AIx) as an index of arterial wave reflections. High on treatment platelet reactivity (HPR) was evaluated using VerifyNow Assay. VerifyNow reports its results in P2Y12 reaction units (PRU), and the diagnostic cutoff value is 230 PRU. Patients were evaluated prospectively up to 24 months. The primary end point was a composite of death from cardiovascular causes, nonfatal major cardiovascular events and hospitalization for cardiovascular causes. RESULTS: There was no difference in the basic clinical and demographic characteristics between subjects with HPR and non-HPR. Subjects with high on treatment platelet reactivity and PRU>230 had significantly increased PWV (8.81 ± 2.25 m/s vs. 7.69 ± 1.95 m/s, p = 0.001) and AIx (25.27 ± 8.67% vs. 20.87 ± 10.57%, p = 0.04) compared to subjects with PRU≤230. PWV was also associated with PRU (r = 0.23, p = 0.02). HPR was associated with significantly increased risk of primary end point [HR = 5.38, 95%CI:(1.15, 26.04), p = 0.03]. CONCLUSIONS: Increased platelet reactivity is associated with impaired arterial stiffness in patients after percutaneous coronary intervention receiving clopidogrel treatment, highlighting another clinical factor implicated in individual platelet response to antiplatelet therapy. Moreover, increased platelet reactivity is associated with adverse outcome in these patients.

Smoking and atherosclerosis: mechanisms of disease and new therapeutic approaches.

It has been clear that at least 1 billion adults worldwide are smokers and at least 700 million children are passive smokers at home. Smoking exerts a detrimental effect to many organ systems and is responsible for illnesses such as lung cancer, pneumonia, chronic obstructive pulmonary disease, cancer of head and neck, cancer of the urinary and gastrointestinal tract, periodontal disease, cataract and arthritis. Additionally, smoking is an important modifiable risk factor for the development of cardiovascular disease such as coronary artery disease, stable angina, acute coronary syndromes, sudden death, stroke, peripheral vascular disease, congestive heart failure, erectile dysfunction and aortic aneurysms via initiation and progression of atherosclerosis. A variety of studies has proved that cigarette smoking induces oxidative stress, vascular inflammation, platelet coagulation, vascular dysfunction and impairs serum lipid pro-file in both current and chronic smokers, active and passive smokers and results in detrimental effects on the cardiovascular system. The aim of this review is to depict the physical and biochemical properties of cigarette smoke and, furthermore, elucidate the main pathophysiological mechanisms of cigarette-induced atherosclerosis and overview the new therapeutic approaches for smoking cessation and augmentation of cardiovascular health.

Vitamin D3, D2 and arterial wall properties in coronary artery disease.

OBJECTIVES: There are two major forms of vitamin D, vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). We studied the effect of the different vitamin D fractions (D3/D2) on arterial wall properties in coronary artery disease (CAD) patients. METHODS: We included 252 subjects with CAD. Endothelial function was evaluated by flow mediated dilation (FMD). Carotid femoral pulse wave velocity (PWV) was measured as an index of arterial stiffness and augmentation index (AI) as a measure of reflected waves. Measures for 25(OH)D2 and 25(OH)D3 were performed using Liquid Chromatography Mass Spectrometry technology. RESULTS: From the study population, 155(62%), 66(26%) and 31(12%) were categorized as having vitamin D deficiency, insufficiency and sufficiency respectively. There was no difference between subjects with vitamin D deficiency, insufficiency and sufficiency in FMD, AI and PWV (p=NS for all). Subjects with vitamin D insufficiency/deficiency had significantly higher D2 to D ratio compared to subjects with vitamin D sufficiency. Interestingly, FMD was positively associated with D2 to D ratio (rho=0.13, p=0.02) and subjects with D2 levels<0.3ng/ml had impaired FMD compared to those with increased D2 levels (p=0.048). CONCLUSION: Vitamin D insufficiency/deficiency is highly prevalent in CAD subjects. Vitamin D2 concentrations are positively associated with endothelial function. These findings may suggest a beneficial role of vitamin D2 levels in vascular health.

Novel biomarkers in heart failure: usefulness in clinical practice.

Biomarkers have become an increasingly important tool in clinical practice, helping to improve patient care. In heart failure (HF), brain natriuretic peptide and N-terminal prohormone of the brain natriuretic peptide have been widely applied in prognosis, clinical diagnosis and treatment. Recently, several novel biomarkers have been examined on their efficacy to improve diagnosis, determine the pathophysiologic state of HF, improve clinical decision making, clinical outcome, guide treatment and assess prognosis of HF patients. In this special report, the authors summarize the usefulness and significance of the most promising novel biomarkers in patients with HF.

Omega-3 PUFAs improved endothelial function and arterial stiffness with a parallel antiinflammatory effect in adults with metabolic syndrome.

OBJECTIVES: Metabolic syndrome (MetS) is associated with adverse cardiovascular events, and impaired vascular function. In this study we evaluated the effects of omega-3 polyunsaturated fatty acids (PUFAs) supplementation on vascular function, inflammatory and fibrinolytic process in subjects with MetS. METHODS: We studied the effect of a 12 weeks oral treatment with 2 g/day of omega-3 PUFAs in 29 (15 male) subjects (mean age 44 ± 12 years) with MetS on three occasions (day0: baseline, day 28 and day 84). The study was carried out on two separate arms (PUFAs and placebo), according to a randomized, placebo-controlled, double-blind, cross-over design. The diagnosis of MetS was based on the guidelines of Adult Treatment Panel III definition. Endothelial function was evaluated by flow-mediated dilation (FMD) of the brachial artery. Carotid-femoral pulse wave velocity (PWV) was measured as an index of aortic stiffness. Serum levels of interleukin-6(IL-6) and plasminogen activator inhibitor-1(PAI-1) were measured by ELISA. RESULTS: Treatment with PUFAs resulted in a significant improvement from day 0 to 28 and 84 in FMD and PWV (p < 0.001 for all). Nevertheless, treatment with placebo resulted in no significant changes in FMD (p = 0.63) and PWV (p = 0.17). Moreover, PUFAs treatment, compared to placebo, decreased IL-6 levels (p = 0.03) and increased PAI-1 levels (p = 0.03). Finally, treatment with PUFAs resulted in a significant decrease in fasting triglyceride levels from day 0 to 28 and 84 (p < 0.001) and in serum total cholesterol levels (p < 0.001). CONCLUSIONS: In subjects with MetS, treatment with omega-3 PUFAs improved endothelial function and arterial stiffness with a parallel antiinflammatory effect.