0000000000187971

AUTHOR

Nico Abegunewardene

Elevated monocyte chemoattractant protein-1 serum levels in patients at risk for coronary artery disease.

Background Monocyte chemoattractant protein-1 (MCP-1) is involved in the recruitment of monocytes into the arterial vessel wall as one of the major events leading to atherosclerotic vascular diseases, such as coronary artery disease (CAD). Methods and Results The study group comprised 263 volunteers aged between 18 and 85 years who were admitted to hospital or clinic for scheduled invasive and non-invasive diagnostic procedures. MCP-1 serum levels were determined using a sandwich-enzyme-linked immunosorbent assay. In each patient, the coronary risk factors (CRF), such as hypertension, high cholesterol, diabetes mellitus, obesity, positive family history, and smoking were evaluated. Low-dens…

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Area at Risk and Viability after Myocardial Ischemia and Reperfusion Can Be Determined by Contrast-Enhanced Cardiac Magnetic Resonance Imaging

<i>Background/Aims:</i> Clinical differentiation between infarcted and viable myocardium in the ischemic area at risk is controversial. We investigated the potential of contrast-enhanced cardiac magnetic resonance imaging (ceCMRI) in determining the area at risk 24 h after ischemia. <i>Methods:</i> Myocardial ischemia was induced by percutaneous coronary intervention of the left anterior descending coronary artery in pigs. Coronary occlusion time was 30 min in group A, which caused little myocardial infarction and 45 min in group B, which led to irreversible damage. 24 h after reperfusion ceCMRI was performed at 2 and 15 min after administration of gadolinium-diethyl…

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Resistance of the internal mammary artery to restenosis: a histomorphologic study of various porcine arteries.

<i>Background/Aims:</i> Restenosis after percutaneous transluminal angioplasty (PTA) of the internal mammary artery (IMA) grafts is much less pronounced than in other arteries and venous grafts. The aim of the study was to test whether various arteries respond differently to dilatation. <i>Methods:</i> PTA of the IMA, carotid, renal and circumflex coronary (RCx) arteries was performed in 9 pigs (balloon to artery ratio of 1:1.5). After 8 weeks, angiography was repeated and vessels prepared for histological analysis. Immunohistochemical staining was done to examine proliferative activity (Ki67) and to identify the vasa vasorum of the adventitia (F VIII-RA). <i>R…

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Local transient myocardial liposomal gene transfer of inducible nitric oxide synthase does not aggravate myocardial function and fibrosis and leads to moderate neovascularization in chronic myocardial ischemia in pigs.

Microcirculation (2010) 17, 69–78. doi: 10.1111/j.1549-8719.2010.00002.x Abstract Background:  This study was designed to explore the effect of transient inducible nitric oxide synthase (iNOS) overexpression via cationic liposome-mediated gene transfer on cardiac function, fibrosis, and microvascular perfusion in a porcine model of chronic ischemia. Methods and Results:  Chronic myocardial ischemia was induced using a minimally invasive model in 23 landrace pigs. Upon demonstration of heart failure, 10 animals were treated with liposome-mediated iNOS-gene-transfer by local intramyocardial injection and 13 animals received a sham procedure to serve as control. The efficacy of this iNOS-gene-…

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Comparison of the quantitative first pass myocardial perfusion MRI with and without prospective slice tracking: Comparison between breath-hold and free-breathing condition

Physiologic motion of the heart is one of the major problems of myocardial blood flow quantification using first pass perfusion-MRI method. To overcome these problems, a perfusion pulse sequence with prospective slice tracking was developed. Cardiac motion was monitored by a navigator directly positioned at heart's basis to overcome no additional underlying model calculations connecting diaphragm and cardiac motion. Additional prescans were used before the perfusion measurement to detect slice displacements caused by remaining cardiac motion between navigator and the perfusion slice readout. The pulse sequence and subsequent quantification of myocardial blood flow was tested in healthy pigs…

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Serial assessments of microvascular obstruction by contrast-enhanced magnetic resonance predict contractile recovery and clinical outcome after reperfused acute myocardial infarction.

AIMS The purpose of the study was to investigate, using cardiac magnetic resonance (CMR), the presence and time course of microvascular obstruction (MO) in patients with acute myocardial infarction (AMI), and to test its relationship with cardiac remodeling and clinical outcomes. METHODS AND RESULTS 53 patients with AMI and successful percutaneous reperfusion underwent CMR examination at four separate timepoints: within the first 48 hours, at 10 days, at six and twelve months after infarction. MO was quantified immediately (early imaging) and 10 minutes (late imaging) after contrast administration in each session. The extent of MO decreased from early to late imaging at both the first and t…

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Gene therapy with iNOS enhances regional contractility and reduces delayed contrast enhancement in a model of postischemic congestive heart failure

Aims: The purpose of this study was to evaluate the effect of transient local myocardial gene transfer of iNOS on cardiac function in a large mammal animal model of heart failure induced by chronic ischemia. Methods: Chronic myocardial ischemia was induced using a minimally invasive model in 16 landrace pigs. Upon demonstration of heart failure, eight animals were treated with liposome-mediated iNOS-gene-transfer by local intramyocardial injection; eight animals received a sham procedure to serve as control. Results: The transmurality of late enhancement (control: 46.4%, iNOS: 35.9%; p < 0.05) was significantly decreased in the ischemic area in the iNOS-treated group. Wall thickness at end-…

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Quantification of resting myocardial blood flow in a pig model of acute ischemia based on first-pass MRI

Qualitative and semiquantitative contrast-enhanced (CE) dynamic perfusion MRI techniques are established as noninvasive diagnostic means of assessing coronary artery disease. However, to date quantification of myocardial blood flow (MBF) has not reached the same acceptance as MBF quantification with nuclear techniques. To validate quantification of MBF at rest using the extracellular contrast agent (CA) Gd-DTPA, we performed an animal study in a pig model of acute myocardial ischemia. We quantified MBF from MRI data with a mathematical model (MMID4) of the underlying vasculature. These MBF results were subsequently compared with the results from fluorescent microspheres. The study showed a …

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914 Contrast enhanced live 3D echo in acute myocardial infarction determines accurate left ventricular wall motion and volumes compared to cardiac MR imaging

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Critical single proximal left arterial descending coronary artery stenosis to mimic chronic myocardial ischemia: a new model induced by minimal invasive technology.

&lt;i&gt;Background/Aims:&lt;/i&gt; The present report examines a new pig model for progressive induction of high-grade stenosis, for the study of chronic myocardial ischemia and the dynamics of collateral vessel growth. &lt;i&gt;Methods:&lt;/i&gt; Thirty-nine Landrace pigs were instrumented with a novel experimental stent (GVD stent) in the left anterior descending coronary artery. Eight animals underwent transthoracic echocardiography at rest and under low-dose dobutamine. Seven animals were examined by nuclear PET and SPECT analysis. Epi-, mid- and endocardial fibrosis and the numbers of arterial vessels were examined by histology. &lt;i&gt;Results:&lt;/i&gt; Functional analysis showed a…

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Influence of contrast agent dose and image acquisition timing on the quantitative determination of nonviable myocardial tissue using delayed contrast-enhanced magnetic resonance imaging.

BACKGROUND: Delayed contrast-enhanced magnetic resonance imaging (ceMRI) has been shown to identify areas of irreversible myocardial injury due to infarction (MI) with high spatial resolution, allowing precise quantification of nonviable (hyperenhanced) myocardium. The aim of our study was to investigate the size of nonviable myocardium quantitatively as a function of time post-contrast when inversion time is held constant in patients post-myocardial infarction using two contrast agent (CA) doses. METHODS: Nine patients with chronic MI underwent two MR scans on a 1.5 Tesla system. Contrast-enhanced MRI data in two short-axis (SA) slices were continuously acquired until 40 minutes after CA i…

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