1,721,040 research outputs found
Comparative study at computed tomography angiography and intravascular ultrasound of coronary atherosclerotic plaques
Full text linkAim. The aim of my doctoral thesis was to estimate the accuracy of coronary computed tomography angiography (CTA) in quantifying calcified and non-calcified coronary artery atherosclerotic plaques in comparison with intravascular ultrasound (IVUS). Moreover, the ability of coronary CTA in predicting the IVUS-derived plaque tissue characterization ("virtual histology", IVUS-VH) was assessed.
Background. Coronary CTA proved to be reliable in detecting and quantifying non-calcified coronary plaques. However, calcified plaques are still challenging its diagnostic accuracy, due to the partial volume averaging effect, leading to overrepresentation of high attenuation objects. Intravascular ultrasound-VH uses spectral analysis of IVUS radiofrequency data to construct tissue maps that classify plaques into four major components: a) fibrous, b) fibro-fatty, c) necrotic core, and d) calcium. It is one of the most promising tools developed for in vivo plaque tissue characterization and correlates well with histology. Computed tomography plaque characterization demonstrated to be a feasible but challenging task. Currently, there are no published studies comparing coronary CTA plaque analysis with IVUS-VH.
Methods. Forty-four patients with stable angina pectoris who underwent 64-multi-detector CTA, invasive coronary angiography, and IVUS have been enrolled. The coronary tree segments under investigation at coronary CTA after comparison with invasive angiography and IVUS, based on landmark branches detected with all these three techniques have been selected. Coronary CTA images with a dedicated workstation in multiplanar reformatted reconstructions on a plane perpendicular to the vessel longitudinal axis were analyzed, blinded to invasive angiography and IVUS results. For comparison with IVUS, the plaque area, as well as the lumen and vessel cross sectional area (CSA) at 3 mm intervals in the segments under investigation were investigated. Atherosclerotic plaques were characterized based on CT attenuation values (HU) and their components classified as necrotic core (HU 0-29), fibro-fatty (HU 30-79), fibrous (HU 80-129), and calcified (HU ? 130). .
Results. Coronary CTA was considered of diagnostic quality in 39 patients, 42 vessels. Intravascular ultrasound-determined mean vessel CSA, mean lumen CSA, mean atherosclerotic plaque area and burden were predicted by coronary CTA: R2 0.6 (p <0.0001), 0.5 (p <0.0001), 0.3 (p <0.0001), and 0.2 (p = 0.04), respectively. After selecting the sections with a calcified plaque component, coronary CTA was still able to predict IVUS-derived vessel CSA, mean lumen CSA, mean atherosclerotic plaque area and burden: R2 0.5 (p <0.0001), 0.6 (p <0.0001), 0.2 (p = 0.02), and 0.2 (p = 0.04), respectively. Finally, coronary CTA plaque tissue characterization was able to predict IVUS-VH-derived atherosclerotic plaque components: R2 0.8 for necrotic core (p = 0.02), 0.5 for fibro-fatty (p = 0.04), 0.5 for fibrous (p = 0.04), 0.7 for calcified (p = 0.02).
Conclusions. Coronary CTA is a robust tool in measuring vessel and lumen CSA in presence of calcified and non-calcified atherosclerotic coronary plaques. "Virtual histology" is feasible with coronary CTA and its plaque characterization predicts IVUS-VH results
Effect of the Asp298 variant of endothelial nitric oxide synthase on survival for patients with congestive heart failure
No full text-786C and G894T variants of the Endothelial Nitric Oxide Synthase Gene and training-induced correction of endothelial dysfunction in coronary artery disease patients.
No full textTo reconsider (limit) the use of phosphate based food and beverages additives. A real need for health preservation.
No full textThe sympathetic nervous system and catecholamines metabolism in obstructive sleep apnoea
Full text linkObstructive sleep apnoea (OSA) is the most common sleep disorder of breathing in middle-aged and overweight subjects. It features recurrent episodes of upper airway total (apnoea) o partial (hypopnea) collapse during sleep, which are associated with a reduction in blood oxygen saturation and with arousal from sleep to re-establish airway patency. An association of OSA with dysregulation of the autonomous nervous system (ANS) and altered catecholamines (CAs) metabolism has been contended for years. However, the pathophysiology mechanisms underlying these alterations remain to be fully clarified. Nonetheless, these alterations are deemed to play a key pathogenic role in the established association of OSA with several conditions besides arterial hypertension (HT), including coronary artery disease, stroke, and, more in general, with increased risk of cardiovascular (CV) events. Hence, in this review we will analyse the relationship between the sleep disturbances associated with OSA and the altered function of the ANS, including CAs metabolism
The Molecular Basis of the Interplay between Endothelin-1 and Nitric Oxide and its Relevance for Atherosclerosis and Arterial and Pulmonary Hypertension.
No full textThe Time has Come for Systematic Screening for Primary Aldosteronism in All Hypertensives
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MINERALOCORTICOID RECEPTOR ANTAGONISTS THERAPY IN RESISTANT HYPERTENSION: TIME TO IMPLEMENT NEW GUIDELINES?
Full text linkDespite the availability of anti-hypertensive medications with increasing efficacy up to 50% of hypertensive patients have blood pressure levels (BP) not at the goals set by international societies. Some of these patients are either not optimally treated or are non adherent to the prescribed drugs, however, a relevant proportion, despite adequate treatment, have resistant hypertension (RH), which represents an important problem in that is associated to an excess risk of cardiovascular events. Notwithstanding a complex pathogenesis, an abundance of data suggests a key contribution for the mineralocorticoid receptor in RH, thus fostering a potential role for its antagonists in this field. Based on these premises randomized clinical trials have been completed aimed at testing the efficacy of mineralocorticoid receptor antagonists (MRA)s in RH patients and demonstrated their efficacy in reducing BP and markers of target organ damage, such as microalbuminuria, compared to either placebo or other drugs. In summary, owing to the role of the mineralocorticoid receptors in the pathogenesis of RH and on their efficacy proved by randomized clinical trials we advocate the inclusion of MRAs as a forth line therapy in patients with RH
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