National Repository of Grey Literature 6 records found  Search took 0.01 seconds. 
Impact of atherosclerotic plaque composition on the development of acute coronary syndrome
Kopřiva, Karel ; Kovárník, Tomáš (advisor) ; Kaňovský, Jan (referee) ; Toušek, Petr (referee)
Thin fibrous cap atheroma with a high lipid content is the most common morphological substrate for acute coronary syndrome. Lipid content can be reliably determined by near infrared spectroscopy (NIRS) imaging. Optical coherence tomography (OCT) is a commonly available morphological imaging method in the guidance of coronary interventions. In our study, we examined a single coronary lesion in patients with acute coronary syndrome using both OCT and NIRS. Based on OCT, we performed a detailed morphological analysis using semi-automated software. Using NIRS, we determined the lipid content of each lesion. In the first part of the study, we used noninvasive CT coronary angiography to detect the progression of atherosclerotic plaques between the first and second year after the initial examination and attempted to demonstrate that morphological characteristics and lipid content of plaques were risk factors for plaque progression. In the second part of the study, we assessed the ability of detailed morphological analysis based on OCT examination to identify the lipid content of plaques using NIRS as a reference method. We observed no significant linear correlation when assessing the relationship between morphological parameters and plaque volume progression. In the analysis of plaque lipid content,...
Biomarkers, intravascular ultrasound and near-infrared spectroscopy in the assessment of vulnerable atherosclerotic plaque
Štěchovský, Cyril ; Hájek, Petr (advisor) ; Krajina, Antonín (referee) ; Kaňovský, Jan (referee)
Biomarkers, Intravascular Ultrasound and Near-Infrared Spectroscopy in the Assessment of Vulnerable Atherosclerotic Plaque Abstract The thesis describes pathophysiology of a vulnerable atherosclerotic plaque, detection of the vulnerable plaque in the stenosis of the internal carotid artery (ICA), and optimalization of carotid stenting (CAS) with near-infrared spectroscopy (NIRS) and intravascular ultrasound (IVUS) imaging. NIRS detects lipid core of the vulnerable lipid rich plaque (LRP). We demonstrated safety of NIRS-IVUS imaging during CAS. LRP was detected in one third of ICAs before CAS. Lipid signal was not correlated with plaque morphology (IVUS), biomarkers or clinical variables. CAS caused significant decrease of the lipid signal. Angiography overestimated severity of stenosis of the ICA and vastly underestimated residual stenosis after CAS. Presence of the LRP in the stenosis was neither associated with periprocedural neurological complications of CAS nor long-term adverse cardiovascular events. IVUS identified planimetric features associated with long-term restenosis or stent occlusion. After a median follow-up of 31 months, repeated NIRS-IVUS of the implanted stents showed significant expansion of the stents, diffuse neointimal hyperplasia and further reduction of the lipid signal. We assume,...
Impact of atherosclerosis and polymorphism of selected genes (endothelial NO synthase and heme oxygenase-1) on coronary artery dilatation
Jeřábek, Štěpán ; Kovárník, Tomáš (advisor) ; Hájek, Petr (referee) ; Kaňovský, Jan (referee)
An essential part of an indication for coronary revascularization is recognition of the lesion causing the myocardial ischemia. Coronary angiography fails in the diagnosis of lesions causing ischemia, primarily in so-called "borderline" lesions (lesions with a 40%-70% reduction in the lumen diameter). This problem is overcome by measuring the pressure gradient across the stenosis. In contemporary practice, we use 2 methods to measure such gradients: fractional flow reserve (FFR), which measures the pressure gradient during hyperemia and across the entire cardiac cycle; and the so-called resting indices (the most well-known of which is instantaneous wave-free ratio - iFR), which measure the pressure gradient without drug- induced hyperemia during mid-diastole. Unfortunately, having both hyperemic and resting indices also opens new problems. Based on previous trials, it is known that the correlation between FFR and iFR is around 80% and that this correlation is much lower when we compare only measurements at or near cutoff points. Our trial was designed to analyze lesions and patients with discordant FFR and iFR findings using clinical, angiographic, and laboratory examinations. Moreover, one of the potential and so far untested reasons for the impaired reaction of endothelial cells to vasoactive...

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4 Kaňovský, Jiří
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