332 research outputs found
Does the routine availability of CT–Derived FFR influence management of patients with stable chest pain compared to CT angiography alone? The FFRCT RIPCORD Study.
No full textOBJECTIVES: This study sought to determine the effect of adding computed tomography–derived fractional flow reserve (FFRCT) data to computed tomography angiographic (CTA) data alone for assessment of lesion severity and patient management in 200 patients with chest pain.BACKGROUND: Invasive and noninvasive tests used in the assessment of patients with angina all have disadvantages. The ideal screening test for patients presenting for the first time with chest pain would describe both coronary anatomy and the presence of ischemia and would be readily accessible, low cost, and noninvasive.METHODS: Two hundred patients with stable chest pain underwent CTA for clinical reasons, and FFRCT was calculated. Three experienced interventional cardiologists assessed the CTA result for each patient and by consensus developed a management plan (optimal medical therapy, percutaneous coronary intervention, coronary artery bypass graft surgery, or more information required). FFRCT data for each vessel were then revealed, and the interventional cardiologists made a second plan by consensus, using the same 4 options. The primary endpoint for the study was the difference between the 2 strategies.RESULTS: Overall, after disclosure of FFRCT data there was a change in the allocated management category on the basis of CTA alone in 72 cases (36%). This difference is explained by a discordance between the CTA- and FFRCT-derived assessments of lesion severity. For example, FFRCT was >0.80 in 13 of 44 vessels (29.5%) graded as having a stenosis>90%. In contrast, FFRCT was #0.80 in 17 of 366 vessels (4.6%) graded as having stenosis #50%.CONCLUSIONS: This study demonstrates proof of concept that the availability of FFRCT results has a substantial effect on the labeling of significant coronary artery disease and therefore on the management of patients compared to CTA alone. Further studies are needed to determine whether FFRCT has potential as a noninvasive diagnostic and management screening tool for patients with stable chest pain
Combination thrombolytic therapy and percutaneous coronary intervention: the future for revascularisation for acute myocardial infarction?
No full textIt seems theoretically sound to consider rescue percutaneous coronary intervention (PCI) in patients with failed thrombolysis. However, randomised controlled data in this setting are limited. In this brief review we will present those trials analysing the role of rescue PCI in patients with acute myocardial infarction and failed thrombolysis, and consider appropriate management strategies in this setting.Stephen G. Worthley, H. M. Omar Farouque, Azfar G. Zaman, and Ian T. Meredit
Progression and regression of atherosclerotic lesions: monitoring with serial noninvasive magnetic resonance imaging
No full text© 2002 American Heart Association, Inc.BackgroundModification or stabilization of atherosclerotic plaques has been proposed as the mechanism responsible for the beneficial clinical effect of lipid-lowering therapies. An imaging modality able to quantify atherosclerotic plaque composition could potentially allow not only the identification of these vulnerable atherosclerotic lesions, but also monitoring of the effects of therapeutic interventions on plaque composition. Our aim was to monitor changes in burden and composition of atherosclerotic plaques in a rabbit model of complex atherosclerosis using serial noninvasive magnetic resonance imaging (MRI).Methods and resultsAortic atherosclerotic lesions were induced in rabbits and the animals randomized to continue an atherogenic diet (atherosclerosis progression) or resume normal chow (atherosclerosis regression) for 6 months. MRI of the aorta was performed at 3 time points in each rabbit, as follows: baseline, after atherosclerosis induction (9 months old), and after atherosclerosis regression or progression (15 months old). Histopathologic correlation with MRI was performed. There was a significant (PConclusionsThese findings indicate that serial noninvasive MRI can monitor changes in atherosclerotic plaque composition under conditions of atherosclerotic progression and regression.Gérard Helft, Stephen G. Worthley, Valentin Fuster, Zahi A. Fayad, Azfar G. Zaman, Roberto Corti, John T. Fallon, and Juan J. Badimo
Atherosclerotic aortic component quantification by noninvasive magnetic resonance imaging: an in vivo study in rabbits
No full text© 2001 by the American College of Cardiology. Published by Elsevier Science Inc.ObjectivesWe sought to demonstrate the ability that noninvasive in vivo magnetic resonance imaging (MRI) has to quantify the different components within atherosclerotic plaque.BackgroundAtherosclerotic plaque composition plays a critical role in both lesion stability and subsequent thrombogenicity. Noninvasive MRI is a promising tool for the characterization of plaque composition.MethodThoracic and abdominal aortic atherosclerotic lesions were induced in rabbits (n = 5). Nine months later, MRI was performed in a 1.5T system. Fast spin-echo sequences (proton density-weighted and T2-weighted [T2W] images) were obtained (in-plane resolution: 350 x 350 microns, slice thickness: 3 mm). Magnetic resonance images were correlated with matched histopathological sections (n = 108).ResultsA significant correlation (p ConclusionsIn vivo noninvasive high resolution MRI accurately quantifies fibrotic and lipidic components of atherosclerosis in this model. This may permit the serial analysis of therapeutic strategies on atherosclerotic plaque stabilization.Gérard Helft, Stephen G. Worthley, Valentin Fuster, Azfar G. Zaman, Clyde Schechter, Julio I. Osende, Oswaldo J. Rodriguez, Zahi A. Fayad, John T. Fallon and Juan J. Badimo
Thyroid Hormones and Cardiovascular Function and Diseases
No full textThyroid hormone (TH) receptors are present in the myocardium and vascular tissue, and minor alterations in TH
concentration can affect cardiovascular (CV) physiology. The potential mechanisms that link CV disease with thyroid
dysfunction are endothelial dysfunction, changes in blood pressure, myocardial systolic and diastolic dysfunction,
and dyslipidemia. In addition, cardiac disease itself may lead to alterations in TH concentrations (notably, low
triiodothyronine syndrome) that are associated with higher morbidity and mortality. Experimental data and small
clinical trials have suggested a beneficial role of TH in ameliorating CV disease. The aim of this review is to provide
clinicians dealing with CV conditions with an overview of the current knowledge of TH perturbations in CV disease
In vivo non-invasive serial monitoring of FDG-PET progression and regression in a rabbit model of atherosclerosis
No full textWe investigated the ability of fluorodeoxyglucose positron emission tomography (FDG PET) imaging to serially monitor macrophage content in a rabbit model of atherosclerosis. Atherosclerosis was induced in rabbits (n = 8) by a combination of atherogenic diet and balloon denudation of the aorta. At the end of nine months, the rabbits were randomized to a further six months of the same atherogenic diet (progression group) or normal diet (regression group). In vivo uptake of FDG by the thoracic aorta was measured using aortic uptake-to-blood radioactivity ratios at the start and end of the randomized period. A significant increase in FDG uptake of the progression group after continued cholesterol feeding (aortic uptake-to-blood radioactivity: 0.57 ± 0.02 to 0.68 ± 0.02, P = 0.001), and a corresponding fall in FDG uptake of the regression group after returning to a normal chow diet (aortic uptake-to-blood radioactivity ratios: 0.67 ± 0.02 to 0.53 ± 0.02, P < 0.0001). FDG PET can quantify in vivo macrophage content and serially monitor changes in FDG activity in this rabbit model.Stephen G. Worthley, Zhuang Y. Zhang, Josef Machac, Gérard Helft, Cheuk Tang, Gary Y. H. Liew, Azfar G. Zaman, Matthew I. Worthley, Zahi A. Fayad, Monte S. Buchsbaum, Valentin Fuster and Juan J. Badimo
Ghayat al-amani and the life and times of al-Hadi Yahya b. al-Husayn: an introduction, newly edited text and translation with detailed annotation
No full textThe thesis is anchored upon a text extracted from an important 11th / 17th century Yemeni historical work. This text deals primarily with al-Hādī ilā 'I-Haqq, the founder of the Zaydī Imamate in the Yemen that lasted well over a thousand years. AI-Hādīs imamate, of considerable significance in itself, also coincides with one of the most turbulent periods of early Yemeni mediaeval history. The- edited Arabic text, with its accompanying apparatus criticus. Is to be found at the opposite end of this volume. The Introduction considers various aspects of Imam al-Hadī’s life, religious ideas and aspirations and matters directly connected with the edited text and the work of which it forms a part. Among the most important subjects discussed are the MSS used in the production of the edited text, the problem concerning the authorship of Ghāyat al-amānī and the relationship of the latter work to Anbā' al-zaman. A short biography of al-Hādī is provided, together with a treatment of the historical background to ai-Hādīs imamate. The introduction also describes the editorial method followed with regard to the text, and certain key personal names and toponyms are dealt with there. The method employed by the author of the Ghāyat is to record the events of any one year by Itself. I have translated one year at a time and then followed it by the annotations appertaining to it. It is hoped that by means of these annotations. (some of which through necessity are quite detailed ), the text will be better understood. The numerous personages, tribal names and toponyms are considered, as well as problems concerning points of chronology and various matters of historical and religious significance. Specific comment is made upon certain interesting terms or any unusual or striking vocabulary. The thesis concludes with maps, genealogical tables and a comprehensive bibliography
Non-invasive imaging of atherosclerotic plaque macrophage in a rabbit model with F-18 FDG PET: a histopathological correlation
No full textBackground: Coronary atherosclerosis and its thrombotic complications are the major cause of mortality and morbidity throughout the industrialized world. Thrombosis on disrupted atherosclerotic plaques plays a key role in the onset of acute coronary syndromes. Macrophages density is one of the most critical compositions of plaque in both plaque vulnerability and thrombogenicity upon rupture. It has been shown that macrophages have a high uptake of 18F-FDG (FDG). We studied the correlation of FDG uptake with histopathological macrophage accumulation in atherosclerotic plaques in a rabbit model. Methods: Atherosclerosis was induced in rabbits (n = 6) by a combination of atherogenic diet and balloon denudation of the aorta. PET imaging was performed at baseline and 2 months after atherogenic diet and coregistered with magnetic resonance (MR) imaging. Normal (n = 3) rabbits served as controls. FDG uptake by the thoracic aorta was expressed as concentration (μCi/ml) and the ratio of aortic uptake-to-blood radioactivity. FDG uptake and RAM-11 antibody positive areas were analyzed in descending aorta. Results: Atherosclerotic aortas showed significantly higher uptake of FDG than normal aortas. The correlation of aortic FDG uptake with macrophage areas assessed by histopathology was statistically significant although it was not high (r = 0.48, p < 0.0001). When uptake was expressed as the ratio of aortic uptake-to-blood activity, it correlated better (r = 0.80, p < 0.0001) with the macrophage areas, due to the correction for residual blood FDG activity. Conclusion: PET FDG activity correlated with macrophage content within aortic atherosclerosis. This imaging approach might serve as a useful non-invasive imaging technique and potentially permit monitoring of relative changes in inflammation within the atherosclerotic lesion.Zhuangyu Zhang, Josef Machac, Gerard Helft, Stephen G Worthley, Cheuk Tang, Azfar G Zaman, Oswaldo J Rodriguez, Monte S Buchsbaum, Valentin Fuster and Juan J Badimo
Cardiac gated breath-hold black blood MRI of the coronary artery wall: an in vivo and ex vivo comparison
No full textThe original publication is available at www.springerlink.comBackground: High resolution magnetic resonance (MR) imaging of the coronary artery wall in vivo has been limited by the cardiac and respiratory motion, flow artifacts as well as the relatively small size of the coronary arteries. We sought to validate in vivo black blood MR imaging of the coronary artery wall using a double inversion recovery fast spin echo MR imaging sequence with limited breath-holding and cardiac gating for suppression of motion artifacts by comparison with ex vivo MR imaging. Methods: Yorkshire albino swine (n = 6) were used in this study and coronary lesions were induced with balloon angioplasty. Four weeks after balloon injury of the coronary arteries MR imaging of the coronary artery lesions was performed. High resolution in vivo and ex vivo images of the coronary artery wall and lesions were obtained using a double inversion recovery fast spin echo sequence in a 1.5 T MR system. There was a statistically significant agreement (p < 0.0001) between measurements of vessel wall area (r = 0.87, slope = 0.87) and maximal wall thickness (r = 0.84, slope = 0.88) from in vivo and ex vivo MR images of the coronary arteries. The mean differences between in vivo and ex vivo measurements were 0.56 ± 1.98 mm2 for vessel wall area and 0.02 ± 0.36 mm for maximal wall thickness. Conclusions: Using breath-holding and cardiac gating, it is possible to perform high resolution MR imaging of the coronary artery wall in vivo with good suppression of motion artifacts with a double inversion recovery fast spin echo black blood imaging sequence.Stephen G. Worthley, Gérard Helft, Zahi A. Fayad, Valentin Fuster, Oswaldo J. Rodriguez, Azfar G. Zaman and Juan J. Badimo
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