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Coronary Artery Disease: HELP
Articles by Roderic I. Pettigrew
Based on 15 articles published since 2008
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Between 2008 and 2019, Roderic Pettigrew wrote the following 15 articles about Coronary Artery Disease.
 
+ Citations + Abstracts
1 Review Biomechanics of atherosclerotic coronary plaque: site, stability and in vivo elasticity modeling. 2014

Ohayon, Jacques / Finet, Gérard / Le Floc'h, Simon / Cloutier, Guy / Gharib, Ahmed M / Heroux, Julie / Pettigrew, Roderic I. ·Laboratory TIMC-IMAG/DyCTiM, UJF, CNRS UMR 5525, In3S, Grenoble, France. ·Ann Biomed Eng · Pubmed #24043605.

ABSTRACT: Coronary atheroma develop in local sites that are widely variable among patients and are considerably variable in their vulnerability for rupture. This article summarizes studies conducted by our collaborative laboratories on predictive biomechanical modeling of coronary plaques. It aims to give insights into the role of biomechanics in the development and localization of atherosclerosis, the morphologic features that determine vulnerable plaque stability, and emerging in vivo imaging techniques that may detect and characterize vulnerable plaque. Composite biomechanical and hemodynamic factors that influence the actual site of development of plaques have been studied. Plaque vulnerability, in vivo, is more challenging to assess. Important steps have been made in defining the biomechanical factors that are predictive of plaque rupture and the likelihood of this occurring if characteristic features are known. A critical key in defining plaque vulnerability is the accurate quantification of both the morphology and the mechanical properties of the diseased arteries. Recently, an early IVUS based palpography technique developed to assess local strain, elasticity and mechanical instabilities has been successfully revisited and improved to account for complex plaque geometries. This is based on an initial best estimation of the plaque components' contours, allowing subsequent iteration for elastic modulus assessment as a basis for plaque stability determination. The improved method has also been preliminarily evaluated in patients with successful histologic correlation. Further clinical evaluation and refinement are on the horizon.

2 Review Detection of high-risk atherosclerotic plaque: report of the NHLBI Working Group on current status and future directions. 2012

Fleg, Jerome L / Stone, Gregg W / Fayad, Zahi A / Granada, Juan F / Hatsukami, Thomas S / Kolodgie, Frank D / Ohayon, Jacques / Pettigrew, Roderic / Sabatine, Marc S / Tearney, Guillermo J / Waxman, Sergio / Domanski, Michael J / Srinivas, Pothur R / Narula, Jagat. ·Division of Cardiovascular Sciences, National Heart, Lung and Blood Institute, Bethesda, Maryland 20892, USA. flegj@nhlbi.nih.gov ·JACC Cardiovasc Imaging · Pubmed #22974808.

ABSTRACT: The leading cause of major morbidity and mortality in most countries around the world is atherosclerotic cardiovascular disease, most commonly caused by thrombotic occlusion of a high-risk coronary plaque resulting in myocardial infarction or cardiac death, or embolization from a high-risk carotid plaque resulting in stroke. The lesions prone to result in such clinical events are termed vulnerable or high-risk plaques, and their identification may lead to the development of pharmacological and mechanical intervention strategies to prevent such events. Autopsy studies from patients dying of acute myocardial infarction or sudden death have shown that such events typically arise from specific types of atherosclerotic plaques, most commonly the thin-cap fibroatheroma. However, the search in human beings for vulnerable plaques before their becoming symptomatic has been elusive. Recently, the PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree) study demonstrated that coronary plaques that are likely to cause future cardiac events, regardless of angiographic severity, are characterized by large plaque burden and small lumen area and/or are thin-cap fibroatheromas verified by radiofrequency intravascular ultrasound imaging. This study opened the door to identifying additional invasive and noninvasive imaging modalities that may improve detection of high-risk atherosclerotic lesions and patients. Beyond classic risk factors, novel biomarkers and genetic profiling may identify those patients in whom noninvasive imaging for vulnerable plaque screening, followed by invasive imaging for risk confirmation is warranted, and in whom future pharmacological and/or device-based focal or regional therapies may be applied to improve long-term prognosis.

3 Article The Imaging Modulography Technique Revisited for High-Definition Intravascular Ultrasound: Theoretical Framework. 2016

Tacheau, Antoine / Le Floc'h, Simon / Finet, Gérard / Doyley, Marvin M / Pettigrew, Roderic I / Cloutier, Guy / Ohayon, Jacques. ·Laboratory TIMC-IMAG/DyCTiM, UJF, CNRS UMR 5525, Grenoble, France. · Laboratory LMGC, CNRS UMR 5508, University of Montpellier II, Montpellier, France. · Department of Hemodynamics and Interventional Cardiology, Hospices Civils de Lyon and Claude Bernard University Lyon, INSERM Unit 886, Lyon, France. · Department of Electrical and Computer Engineering, University of Rochester, Rochester, New York, USA. · Laboratory of Integrative Cardiovascular Imaging Science, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA. · Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center (CRCHUM), Montréal, Québec, Canada. · Laboratory TIMC-IMAG/DyCTiM, UJF, CNRS UMR 5525, Grenoble, France; University Grenoble-Alpes, Polytech Annecy-Chambéry, Le Bourget du Lac, France. Electronic address: jacques.ohayon@imag.fr. ·Ultrasound Med Biol · Pubmed #26738628.

ABSTRACT: Mechanical characterization of atherosclerotic lesions remains an essential step for the detection of vulnerable plaques (VPs). Recently, an intravascular ultrasound (IVUS) elasticity reconstruction method (iMOD) has been tested in vivo by our group. The major limitation of iMOD is the need to estimate the strain field in the entire VP despite attenuated depth penetration signals when using high-definition (HD) IVUS systems. Therefore, an extended iMOD approach (E-iMOD) was designed and applied to coronary lesions of patients imaged in vivo with IVUS. The E-iMOD method (i) quantified necrotic core areas with a mean absolute relative error of 3.5 ± 3.5% and (ii) identified Young's moduli of the necrotic cores and fibrous regions with mean values of 5.7 ± 0.8 kPa and 794.5 ± 22.0 kPa instead of 5 kPa and 800 kPa, respectively. This study demonstrates the potential of the improved HD-IVUS modulography technique E-iMOD to characterize coronary VPs.

4 Article The intravascular ultrasound elasticity-palpography technique revisited: a reliable tool for the in vivo detection of vulnerable coronary atherosclerotic plaques. 2013

Deleaval, Flavien / Bouvier, Adeline / Finet, Gérard / Cloutier, Guy / Yazdani, Saami K / Le Floc'h, Simon / Clarysse, Patrick / Pettigrew, Roderic I / Ohayon, Jacques. ·Laboratory TIMC-IMAG/DyCTiM, UJF, CNRS UMR 5525, In(3)S, Grenoble, France. ·Ultrasound Med Biol · Pubmed #23727295.

ABSTRACT: Critical to the detection of vulnerable plaques (VPs) is quantification of their mechanical properties. On the basis of intravascular ultrasound (IVUS) echograms and strain images, E. I. Céspedes, C. L. de Korte CL and A. F. van der Steen (Ultrasound Med Biol 2000;26:385-396) proposed an elasticity-palpography technique (E-PT) to estimate the apparent stress-strain modulus palpogram of the thick endoluminal layer of the arterial wall. However, this approach suffers from major limitations because it was developed for homogeneous, circular and concentric VPs. The present study was therefore designed to improve the E-PT by considering the anatomic shape of the VP. This improved E-PT was successfully applied to six coronary lesions of patients imaged in vivo with IVUS. Our results indicate that the mean relative error of the stress-strain modulus decreased from 61.02 ± 9.01% to 15.12 ± 12.57% when the IE-PT was used instead of the E-PT. The accuracy of the stress-strain modulus palpograms computed using the improved theoretical framework was also investigated with respect to noise, which may affect prediction of plaque vulnerability.

5 Article Feasibility of coronary artery wall thickening assessment in asymptomatic coronary artery disease using phase-sensitive dual-inversion recovery MRI at 3T. 2013

Gharib, Ahmed M / Zahiri, Homeira / Matta, Jatin / Pettigrew, Roderic I / Abd-Elmoniem, Khaled Z. ·Biomedical and Metabolic Imaging Branch, The National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA. ·Magn Reson Imaging · Pubmed #23642801.

ABSTRACT: OBJECTIVES: The purpose of this study was to (a) investigate the image quality of phase-sensitive dual-inversion recovery (PS-DIR) coronary wall imaging in healthy subjects and in subjects with known coronary artery disease (CAD) and to (b) investigate the utilization of PS-DIR at 3T in the assessment of coronary artery thickening in subjects with asymptomatic but variable degrees of CAD. MATERIALS AND METHODS: A total of 37 subjects participated in this institutional review board-approved and HIPAA-compliant study. These included 21 subjects with known CAD as identified on multidetector computed tomography angiography (MDCT). Sixteen healthy subjects without known history of CAD were included. All subjects were scanned using free-breathing PS-DIR magnetic resonance imaging (MRI) for the assessment of coronary wall thickness at 3T. Lumen-tissue contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR) and quantitative vessel parameters including lumen area and wall thickness were measured. Statistical analyses were performed. RESULTS: PS-DIR was successfully completed in 76% of patients and in 88% of the healthy subjects. Phase-sensitive signed-magnitude reconstruction, compared to modulus-magnitude images, significantly improved lumen-tissue CNR in healthy subjects (26.73±11.95 vs. 14.65±9.57, P<.001) and in patients (21.45±7.61 vs. 16.65±5.85, P<.001). There was no difference in image CNR and SNR between groups. In arterial segments free of plaques, coronary wall was thicker in patients in comparison to healthy subjects (1.74±0.27 mm vs. 1.17±0.14 mm, P<.001), without a change in lumen area (4.51±2.42 mm2 vs. 5.71±3.11mm2, P=.25). CONCLUSIONS: This is the first study to demonstrate the feasibility of successfully obtaining vessel wall images at 3T using PS-DIR in asymptomatic patients with known variable degrees of CAD as detected by MDCT. This was achieved with a fixed subject-invariant planning of blood signal nulling. With that limitation alleviated, PS-DIR coronary wall MRI is capable of detecting arterial thickening and positive arterial remodeling at 3T in asymptomatic CAD.

6 Article Hypercortisolism is associated with increased coronary arterial atherosclerosis: analysis of noninvasive coronary angiography using multidetector computerized tomography. 2013

Neary, Nicola M / Booker, O Julian / Abel, Brent S / Matta, Jatin R / Muldoon, Nancy / Sinaii, Ninet / Pettigrew, Roderic I / Nieman, Lynnette K / Gharib, Ahmed M. ·Program in Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA. ·J Clin Endocrinol Metab · Pubmed #23559084.

ABSTRACT: BACKGROUND: Observational studies show that glucocorticoid therapy and the endogenous hypercortisolism of Cushing's syndrome (CS) are associated with increased rates of cardiovascular morbidity and mortality. However, the causes of these findings remain largely unknown. OBJECTIVE: To determine whether CS patients have increased coronary atherosclerosis. DESIGN: A prospective case-control study was performed. SETTING: Subjects were evaulated in a clinical research center. SUBJECTS: Fifteen consecutive patients with ACTH-dependent CS, 14 due to an ectopic source and 1 due to pituitary Cushing's disease were recruited. Eleven patients were studied when hypercortisolemic; 4 patients were eucortisolemic due to medication (3) or cyclic hypercortisolism (1). Fifteen control subjects with at least one risk factor for cardiac disease were matched 1:1 for age, sex, and body mass index. PRIMARY OUTCOME VARIABLES: Agatston score a measure of calcified plaque and non-calcified coronary plaque volume were quantified using a multidetector CT (MDCT) coronary angiogram scan. Additional variables included fasting lipids, blood pressure, history of hypertension or diabetes, and 24-hour urine free cortisol excretion. RESULTS: CS patients had significantly greater noncalcified plaque volume and Agatston score (noncalcified plaque volume [mm(3)] median [interquartile ranges]: CS 49.5 [31.4, 102.5], controls 17.9 [2.6, 25.3], P < .001; Agatston score: CS 70.6 [0, 253.1], controls 0 [0, 7.6]; P < .05). CS patients had higher systolic and diastolic blood pressures than controls (systolic: CS 143 mm Hg [135, 173]; controls, 134 [123, 136], P < .02; diastolic CS: 86 [80, 99], controls, 76 [72, 84], P < .05). CONCLUSIONS: Increased coronary calcifications and noncalcified coronary plaque volumes are present in patients with active or previous hypercortisolism. Increased atherosclerosis may contribute to the increased rates of cardiovascular morbidity and mortality in patients with glucocorticoid excess.

7 Article A four-criterion selection procedure for atherosclerotic plaque elasticity reconstruction based on in vivo coronary intravascular ultrasound radial strain sequences. 2012

Le Floc'h, Simon / Cloutier, Guy / Saijo, Yoshifumi / Finet, Gérard / Yazdani, Saami K / Deleaval, Flavien / Rioufol, Gilles / Pettigrew, Roderic I / Ohayon, Jacques. ·Laboratory TIMC-IMAG/DyCTiM, UJF, CNRS UMR 5525, Grenoble, France. ·Ultrasound Med Biol · Pubmed #23196202.

ABSTRACT: Plaque elasticity (i.e., modulogram) and morphology are good predictors of plaque vulnerability. Recently, our group developed an intravascular ultrasound (IVUS) elasticity reconstruction method which was successfully implemented in vitro using vessel phantoms. In vivo IVUS modulography, however, remains a major challenge as the motion of the heart prevents accurate strain field estimation. We therefore designed a technique to extract accurate strain fields and modulograms from recorded IVUS sequences. We identified a set of four criteria based on tissue overlapping, RF-correlation coefficient between two successive frames, performance of the elasticity reconstruction method to recover the measured radial strain, and reproducibility of the computed modulograms over the cardiac cycle. This four-criterion selection procedure (4-CSP) was successfully tested on IVUS sequences obtained in twelve patients referred for a directional coronary atherectomy intervention. This study demonstrates the potential of the IVUS modulography technique based on the proposed 4-CSP to detect vulnerable plaques in vivo.

8 Article Coronary vessel wall 3-T MR imaging with time-resolved acquisition of phase-sensitive dual inversion-recovery (TRAPD) technique: initial results in patients with risk factors for coronary artery disease. 2012

Abd-Elmoniem, Khaled Z / Gharib, Ahmed M / Pettigrew, Roderic I. ·Biomedical and Metabolic Imaging Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 10 Center Dr, Bldg 10, Room 3-5340, Bethesda, MD 20892, USA. abdelmoniemkz@mail.nih.gov ·Radiology · Pubmed #23047838.

ABSTRACT: PURPOSE: To develop a technique for time-resolved acquisition of phase-sensitive dual-inversion recovery (TRAPD) coronary vessel wall magnetic resonance (MR) images, to investigate the success rate in coronary wall imaging compared with that of single-frame imaging, and to assess vessel wall thickness in healthy subjects and subjects with risk factors for coronary artery disease (CAD). MATERIALS AND METHODS: Thirty-eight subjects (12 healthy subjects, 26 subjects with at least one CAD risk factor) provided informed consent for participation in this institutional review board-approved and HIPAA-compliant study. The TRAPD coronary vessel wall imaging sequence was developed and validated with a flow phantom. Time-resolved coronary artery wall images at three to five cine phases were obtained in all subjects. Qualitative and quantitative comparisons were made between TRAPD and conventional single-image wall measurements. Measurement reproducibility also was assessed. Statistical analysis was performed for all comparisons. RESULTS: The TRAPD sequence successfully restored the negative polarity of lumen signal and enhanced lumen wall contrast on the cine images of the flow phantom and in all subjects. Use of three to five frames increased the success rate of acquiring at least one image of good to excellent quality from 76% in single-image acquisitions to 95% with the TRAPD sequence. The difference in vessel wall thickness between healthy subjects and subjects with CAD risk factors was significant (P < .05) with the TRAPD sequence (1.07 vs 1.46 mm, respectively; 36% increase) compared with single-frame dual inversion-recovery imaging (1.24 vs 1.55 mm, respectively; 25% increase). Intraobserver, interobserver, and interexamination agreement for wall thickness measurement were 0.98, 0.97, and 0.92, respectively. CONCLUSION: TRAPD imaging of coronary arteries improved arterial wall visualization and quantitative assessment by increasing the success rate of obtaining good- to excellent-quality images and sections orthogonal to the longitudinal axis of the vessel. This also resulted in vessel wall thickness measurements that show a more distinct difference between healthy subjects and those with CAD risk factors. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120068/-/DC1.

9 Article The feasibility of 350 μm spatial resolution coronary magnetic resonance angiography at 3 T in humans. 2012

Gharib, Ahmed M / Abd-Elmoniem, Khaled Z / Ho, Vincent B / Födi, Eszter / Herzka, Daniel A / Ohayon, Jacques / Stuber, Matthias / Pettigrew, Roderic I. ·National Institutes of Health, NIDDK, Bethesda, MD 20892, USA. agharib@mail.nih.gov ·Invest Radiol · Pubmed #22551651.

ABSTRACT: PURPOSE: The purposes of this study were to (1) develop a high-resolution 3-T magnetic resonance angiography (MRA) technique with an in-plane resolution approximate to that of multidetector coronary computed tomography (MDCT) and a voxel size of 0.35 × 0.35 × 1.5 mm³ and to (2) investigate the image quality of this technique in healthy participants and preliminarily in patients with known coronary artery disease (CAD). MATERIALS AND METHODS: A 3-T coronary MRA technique optimized for an image acquisition voxel as small as 0.35 × 0.35 × 1.5 mm³ (high-resolution coronary MRA [HRC]) was implemented and the coronary arteries of 22 participants were imaged. These included 11 healthy participants (average age, 28.5 years; 5 men) and 11 participants with CAD (average age, 52.9 years; 5 women) as identified on MDCT. In addition, the 11 healthy participants were imaged using a method with a more common spatial resolution of 0.7 × 1 × 3 mm³ (regular-resolution coronary MRA [RRC]). Qualitative and quantitative comparisons were made between the 2 MRA techniques. RESULTS: Normal vessels and CAD lesions were successfully depicted at 350 × 350 μm² in-plane resolution with adequate signal-to-noise ratio (SNR) and contrast-to-noise ratio. The CAD findings were consistent among MDCT and HRC. The HRC showed a 47% improvement in sharpness despite a reduction in SNR (by 72%) and in contrast-to-noise ratio (by 86%) compared with the regular-resolution coronary MRA. CONCLUSION: This study, as a first step toward substantial improvement in the resolution of coronary MRA, demonstrates the feasibility of obtaining at 3 T a spatial resolution that approximates that of MDCT. The acquisition in-plane pixel dimensions are as small as 350 × 350 μm² with a 1.5-mm slice thickness. Although SNR is lower, the images have improved sharpness, resulting in image quality that allows qualitative identification of disease sites on MRA consistent with MDCT.

10 Article Noninvasive coronary imaging for atherosclerosis in human immunodeficiency virus infection. 2011

Gharib, Ahmed M / Abd-Elmoniem, Khaled Z / Pettigrew, Roderic I / Hadigan, Colleen. ·Biomedical and Metabolic Imaging Branch, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD. agharib@mail.nih.gov ·Curr Probl Diagn Radiol · Pubmed #21939819.

ABSTRACT: Coronary artery disease is increasingly recognized as an important contributor to morbidity and mortality among persons living with human immunodeficiency virus (HIV) infection. Traditional cardiovascular disease risk factors as well as aspects of HIV infection and its therapy contribute to the increased coronary artery disease observed in HIV. Advances in noninvasive imaging methodologies in both computed tomography and magnetic resonance imaging provide opportunities to evaluate coronary artery atherosclerosis in ways not possible by conventional invasive x-ray angiography. Application of these techniques may prove very useful in the study of atherosclerosis in many diseases, such as HIV.

11 Article Is arterial wall-strain stiffening an additional process responsible for atherosclerosis in coronary bifurcations?: an in vivo study based on dynamic CT and MRI. 2011

Ohayon, Jacques / Gharib, Ahmed M / Garcia, Alberto / Heroux, Julie / Yazdani, Saami K / Malvè, Mauro / Tracqui, Philippe / Martinez, Miguel-Angel / Doblare, Manuel / Finet, Gérard / Pettigrew, Roderic I. ·Laboratory of Integrative Cardiovascular Imaging Science, National Institute of Diabetes Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA. jacques.ohayon@imag.fr ·Am J Physiol Heart Circ Physiol · Pubmed #21685261.

ABSTRACT: Coronary bifurcations represent specific regions of the arterial tree that are susceptible to atherosclerotic lesions. While the effects of vessel compliance, curvature, pulsatile blood flow, and cardiac motion on coronary endothelial shear stress have been widely explored, the effects of myocardial contraction on arterial wall stress/strain (WS/S) and vessel stiffness distributions remain unclear. Local increase of vessel stiffness resulting from wall-strain stiffening phenomenon (a local process due to the nonlinear mechanical properties of the arterial wall) may be critical in the development of atherosclerotic lesions. Therefore, the aim of this study was to quantify WS/S and stiffness in coronary bifurcations and to investigate correlations with plaque sites. Anatomic coronary geometry and cardiac motion were generated based on both computed tomography and MRI examinations of eight patients with minimal coronary disease. Computational structural analyses using the finite element method were subsequently performed, and spatial luminal arterial wall stretch (LW(Stretch)) and stiffness (LW(Stiff)) distributions in the left main coronary bifurcations were calculated. Our results show that all plaque sites were concomitantly subject to high LW(Stretch) and high LW(Stiff), with mean amplitudes of 34.7 ± 1.6% and 442.4 ± 113.0 kPa, respectively. The mean LW(Stiff) amplitude was found slightly greater at the plaque sites on the left main coronary artery (mean value: 482.2 ± 88.1 kPa) compared with those computed on the left anterior descending and left circumflex coronary arteries (416.3 ± 61.5 and 428.7 ± 181.8 kPa, respectively). These findings suggest that local wall stiffness plays a role in the initiation of atherosclerotic lesions.

12 Article Coronary artery abnormalities in Hyper-IgE syndrome. 2011

Freeman, Alexandra F / Avila, Elizabeth Mannino / Shaw, Pamela A / Davis, Joie / Hsu, Amy P / Welch, Pamela / Matta, Jatin R / Hadigan, Colleen / Pettigrew, Roderic I / Holland, Steven M / Gharib, Ahmed M. ·Immunopathogenesis Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases (NIAID), 10 Center Drive, Bethesda, MD 20892-1899, USA. freemaal@mail.nih.gov ·J Clin Immunol · Pubmed #21494893.

ABSTRACT: OBJECTIVE: Hyper-IgE syndrome (HIES) is a rare primary immunodeficiency caused by autosomal dominant STAT3 mutations resulting in recurrent infections and connective tissue abnormalities. Coronary artery abnormalities have been reported infrequently. We aimed to determine the frequency and characteristics of coronary artery abnormalities. DESIGN: STAT3-mutated HIES patients (n=38), ranging in age from 8 to 57 years, underwent coronary artery imaging by computed tomography or magnetic resonance imaging. Images were evaluated for tortuosity, dilation, and aneurysm. Charts were reviewed for cardiac risk factors. To allow blinded image interpretation, an age- and gender-matched non-HIES group was also evaluated (n=33). RESULTS: Coronary artery tortuosity or dilation occurred in 70% of HIES patients, with aneurysms present in 37%, incidences much higher than in the literature and in our non-HIES group, in which 21% had tortuosity or dilation and 3% had aneurysms. Hypertension was more common in the HIES group than in the general population and was associated with vessel abnormalities. Atherosclerosis was uncommon and mild. CONCLUSIONS: Coronary artery aneurysms and tortuosity are common in HIES, despite a paucity of atherosclerosis, suggesting that STAT3 plays an integral role in human vascular remodeling and atherosclerosis.

13 Article High rate of coronary artery abnormalities in adolescents and young adults infected with human immunodeficiency virus early in life. 2011

Mikhail, Irene J / Purdy, Julia B / Dimock, David S / Thomas, Vijaya M / Muldoon, Nancy A / Clauss, Sarah B / Cross, Russell R / Pettigrew, Roderic I / Hazra, Rohan / Hadigan, Colleen / Gharib, Ahmed M. ·National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD 20892-1662, USA. jacoubi@mail.nih.gov ·Pediatr Infect Dis J · Pubmed #21307818.

ABSTRACT: We completed a cross-sectional study of individuals infected with human immunodeficiency virus in early childhood using cardiac magnetic resonance imaging and magnetic resonance angiography. Coronary artery abnormality (CAA) was defined by the presence of luminal narrowing and irregularity of the coronary vessel wall. More than 50% of participants (14/27) had evidence of CAA. Individuals had a high rate of CAA, suggesting possible early atherosclerosis.

14 Article Vulnerable atherosclerotic plaque elasticity reconstruction based on a segmentation-driven optimization procedure using strain measurements: theoretical framework. 2009

Le Floc'h, Simon / Ohayon, Jacques / Tracqui, Philippe / Finet, Gérard / Gharib, Ahmed M / Maurice, Roch L / Cloutier, Guy / Pettigrew, Roderic I. ·Laboratory TIMC, DynaCell, CNRSUMR 5525, Institut de l'Ingénierie et de l'Information de Santé (In3S), 38 706 Grenoble, France. ·IEEE Trans Med Imaging · Pubmed #19164080.

ABSTRACT: It is now recognized that prediction of the vulnerable coronary plaque rupture requires not only an accurate quantification of fibrous cap thickness and necrotic core morphology but also a precise knowledge of the mechanical properties of plaque components. Indeed, such knowledge would allow a precise evaluation of the peak cap-stress amplitude, which is known to be a good biomechanical predictor of plaque rupture. Several studies have been performed to reconstruct a Young's modulus map from strain elastograms. It seems that the main issue for improving such methods does not rely on the optimization algorithm itself, but rather on preconditioning requiring the best estimation of the plaque components' contours. The present theoretical study was therefore designed to develop: 1) a preconditioning model to extract the plaque morphology in order to initiate the optimization process, and 2) an approach combining a dynamic segmentation method with an optimization procedure to highlight the modulogram of the atherosclerotic plaque. This methodology, based on the continuum mechanics theory prescribing the strain field, was successfully applied to seven intravascular ultrasound coronary lesion morphologies. The reconstructed cap thickness, necrotic core area, calcium area, and the Young's moduli of the calcium, necrotic core, and fibrosis were obtained with mean relative errors of 12%, 4% and 1%, 43%, 32%, and 2%, respectively.

15 Article Necrotic core thickness and positive arterial remodeling index: emergent biomechanical factors for evaluating the risk of plaque rupture. 2008

Ohayon, Jacques / Finet, Gérard / Gharib, Ahmed M / Herzka, Daniel A / Tracqui, Philippe / Heroux, Julie / Rioufol, Gilles / Kotys, Melanie S / Elagha, Abdalla / Pettigrew, Roderic I. ·National Heart, Lung and Blood Institute, NIH, Bldg. 10, 10 Center Dr., Bethesda, MD 20892, USA. ohayonj2@mail.nih.gov ·Am J Physiol Heart Circ Physiol · Pubmed #18586893.

ABSTRACT: Fibrous cap thickness is often considered as diagnostic of the degree of plaque instability. Necrotic core area (Core(area)) and the arterial remodeling index (Remod(index)), on the other hand, are difficult to use as clinical morphological indexes: literature data show a wide dispersion of Core(area) thresholds above which plaque becomes unstable. Although histopathology shows a strong correlation between Core(area) and Remod(index), it remains unclear how these interact and affect peak cap stress (Cap(stress)), a known predictor of rupture. The aim of this study was to investigate the change in plaque vulnerability as a function of necrotic core size and plaque morphology. Cap(stress) value was calculated on 5,500 idealized atherosclerotic vessel models that had the original feature of mimicking the positive arterial remodeling process described by Glagov. Twenty-four nonruptured plaques acquired by intravascular ultrasound on patients were used to test the performance of the associated idealized morphological models. Taking advantage of the extensive simulations, we investigated the effects of anatomical plaque features on Cap(stress). It was found that: 1) at the early stages of positive remodeling, lesions were more prone to rupture, which could explain the progression and growth of clinically silent plaques and 2) in addition to cap thickness, necrotic core thickness, rather than area, was critical in determining plaque stability. This study demonstrates that plaque instability is to be viewed not as a consequence of fibrous cap thickness alone but rather as a combination of cap thickness, necrotic core thickness, and the arterial remodeling index.