Panagiotis Tourikis

MicroRNAs in Cardiovascular Therapeutics

Recent research reveals the crucial role microRNAs (miRNAs) in the pathogenesis and progression of many pathological conditions, including cardiovascular diseases. It is widely documented that miRNAs represent critical regulators of cardiovascular function and participate in almost all aspects of cardiovascular biology. In particular, they are involved in several pathophysiological pathways of various manifestations of cardiovascular disease, such as coronary artery disease, heart failure, stroke, diabetes mellitus, arterial hypertension and cardiac arrhythmias. In the present article we review the available literature regarding to the role of miRNAs in certain cardiovascular conditions. Moreover, we discuss the therapeutic potential of miRNAs for treating cardiovascular diseases and we attempt to highlight future directions.

Novel Biomarkers Assessing Renal Function in Heart Failure: Relation to Inflammatory Status and Cardiac Remodelling

BACKGROUND Patients with heart failure (HF) have a significant decline of renal function. We investigate the association between novel biomarkers of renal dysfunction and indices of inflammatory status and cardiac remodeling in patients with HF. METHODS We enrolled 79 consecutive patients with HF and 79 healthy subjects, adjusted for age and sex. Serum levels of neutrophil gelatinase-associated lipocalin (NGAL), cystatin-C, b-type natriuretic peptide (BNP), tumor necrosis factor alpha (TNFα) and matrix metalloproteinase-9 (MMP-9) were measured by ELISA. Creatinine clearance was estimated using Cockcroft-Gault formula (eCcl). Left ventricular ejection fraction was determined by echocardiography. RESULTS Patients with HF, compared to healthy subjects, had significantly higher NGAL (p=0.007) and cystatin-C levels (p=0.005). In HF patients, NGAL levels were positively correlated with Creatinine levels (r=0.40, p<0.001), TNFa levels (r=0.43, p<0.001), BNP levels (r=0.36, p=0.003), MMP-9 levels (r=0.37, p=0.02) and inversely correlated with left ventricle ejection fraction (r=-0.23, p=0.045). Interestingly, the association between NGAL and MMP-9 levels was independent from confounders such as age, gender, left ventricle ejection fraction, body mass index, TNFα levels, and BNP levels. Moreover, in HF patients, cystatin-C levels were inversely correlated with eCcl (r=-0.21, p=0.04). Cystatin-C levels were not correlated with TNFa, BNP, MMP-9 levels and with left ventricle ejection fraction (p=NS for all). CONCLUSIONS NGAL is associated with left ventricle ejection fraction, and biomarkers of inflammation and cardiac remodeling in patients with HF. These findings highlight a possible common pathogenetic mechanism of renal dysfunction, inflammatory process and cardiac dysfunction in HF.

Novel Risk Factors Related to Stable Angina

Stable angina (SA) pectoris is a common and disabling disorder in patients with coronary artery disease (CAD), with increasing epidemiology and is associated with myocardial infarction and increased mortality. However, within the population of SA patients, an individuals prognosis can vary considerably. Except from conventional risk factors a variety of biomarkers have been evaluated for their prognostic significance in the settings of SA. Novel biomarkers associated with inflammatory status, such as C reactive protein and tumor necrosis factor alpha, with myocardial performance, such as B-type natriuretic peptide, with extracellular matrix remodeling, with vascular calcification such as osteoprotogerin and osteopontin, with myocardial ischemia, such as ischemia modified albumin have been associated with the progression of CAD and with the prognosis of SA patients. Despite the multiplicity of novel biomarkers there is lack of a clinical useful, highly specific for CAD biomarker with the ability to guide treatment decisions. In the context of this evidence in this review article we summarize the so far acquired knowledge of the most promising biomarkers and we discuss the major clinical correlations of novel risk factors with SA physical history, their predictive value for future cardiovascular events and their use in the treatment monitoring of this population.

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.

Insight to the Pathophysiology of Stable Angina Pectoris

Atherosclerosis is a chronic disease which mainly represents an inflammatory response in the vessels. Myocardial ischemia manifested by angina pectoris can be either acute or chronic and usually is a result of imbalance between myocardial oxygen supply and myocardial oxygen demand. Chronic stable angina is chest discomfort attributed to myocardial ischemia without the presence of necrosis and is the most common symptom encountered by emergency room physicians. A growing amount of data has shown that endothelial dysfunction, is now considered an important early event in the development of atherosclerosis, while in the absence of angiographically obstructive coronary artery disease, anginal chest pain is often attributed to microvascular coronary dysfunction. Moreover, atheroma formation and in turn, atherosclerotic plaques seem to affect coronary flow, given that multivessel flow-limiting obstructions are observed in patients with chronic coronary syndrome. Morphological changes of diseased arteries related to significant atherosclerosis, such as vascular remodeling may also result in stable angina or claudication. However, several issues with respect to the comprehension of the pathophysiology of the chronic coronary syndrome have not been fully elucidated.

ACUTE EFFECTS OF DIFFERENT TYPES OF AEROBIC EXERCISE ON VASCULAR FUNCTION

Chronic exercise training improves endothelial function in individuals with cardiovascular diseases. Endothelial function and arterial stiffness are key players in the pathophysiology of atherosclerotic disease. We investigated the acute effects of continuous moderate-intensity aerobic exercise (CAE

ENDOTHELIAL FUNCTION AND CIRCULATING CD4 T CELLS IN PATIENTS WITH UNSTABLE ANGINA

Previous studies support the crucial role of immune responses in the development and progression of atherosclerosis. CD4+CD28null T cells and CD4+CD31- T cells represent two specific subsets of circulating CD4+ T cells that affect endothelium. However, their accurate role on endothelial function

IMPAIRED ENDOTHELIAL FUNCTION AND INCREASED ARTERIAL STIFFNESS IN PATIENTS WITH DIABETIC RETINOPATHY

Diabetes Mellitus is associated with endothelial dysfunction and arterial stiffness. Diabetic Retinopathy (DR) is a complication of diabetes mellitus and remains a leading cause of irreversible blindness. We investigated the possible association of DR with endothelial function, arterial stiffness