Plaque in superficial femoral arteries indicates generalized atherosclerosis and vulnerability to coronary death: An autopsy study

ObjectivesRisk factors for atherosclerosis have limited ability to identify persons at high risk of coronary heart disease. Assessment of subclinical atherosclerosis in peripheral arteries might improve this limitation. We studied the relationship between atherosclerotic plaques in peripheral arteries, coronary plaques, and coronary death.MethodsPredefined segments from the left anterior descending coronary artery, the right coronary artery, bilateral carotid, and superficial femoral arteries (SFA) were obtained from 100 autopsies (20-82 years, 30 females, 27 coronary deaths). Based on microscopic examination of 4756 sections, the extension of atherosclerosis (plaque burden) and the largest plaque area in each segment were quantified.ResultsPlaque burden in all arteries increased with age and was larger in coronary death (P < .05). SFA plaques occurred later than coronary and carotid plaques. When SFA plaque had developed, coronary plaque was also present. SFA plaque (odds ratio, 95% confidence interval: 7.07 [2.40-20.81]), but not carotid plaque, was significantly associated with coronary death, also after age and gender adjustment (21.25 [5.02-89.97]). The area under the receiver operating characteristic curves for the identification of coronary death individuals was 0.72 (95% confidence interval: 0.62-0.83) for coronary plaque, and 0.80 (0.72-0.89) for SFA plaque (age and gender adjusted).ConclusionsAtherosclerosis develops slower in SFA compared with coronary and carotid arteries. In persons with plaque in the SFA, plaque is always present in the coronary arteries. In younger persons, the presence of SFA plaque indicates a generalized susceptibility to atherosclerosis and vulnerability to coronary death

In vivo heating of pacemaker leads during magnetic resonance imaging

Aims Magnetic resonance imaging (MRI) is well established as an important diagnostic tool in medicine. However, the presence of a cardiac pacemaker is usually regarded as a contraindication for MRI due to safety reasons. In this study, heating effects at the myocardium-pacemaker lead tip interface have been investigated in a chronic animal model during MRI at 1.5 Tesla. Methods and results Pacemaker leads with additional thermocouple wires as temperature sensors were implanted in nine animals. Temperature increases of up to 20°C were measured during MRI of the heart. Significant impedance and minor stimulation threshold changes could be seen. However, pathology and histology could not clearly demonstrate heat-induced damage. Conclusions MRI may produce considerable heating at the lead tip. Changes of pacing parameters due to MRI could be seen in chronic experiments. Potential risk of tissue damage cannot be excluded even though no reproducible alterations at the histological level could be foun

Spatial orientation of cross-sectional images of coronary arteries: point of view in intracoronary imaging

<p>Abstract</p> <p>Background</p> <p>In studies where cross-sectional images of coronary arteries obtained with different imaging modalities are compared, the importance of correct co-localization and matching of images along the coronary artery longitudinal axis is obvious. However, it appears neglected that correct spatial orientation of the cross-sectional plane may not be obtainable just by rotating the images to ensure co-localization of identifiable landmarks such as sidebranches. A cross-section has two sides, one facing proximally and the other distally, and pairs of images reconstructed corresponding to these opposite points of view are mirror images of each other and not superimposable. This may be difficult if not impossible to recognize and unrecognized it will give rise to flawed results in the development and validation of imaging technologies aimed at plaque characterization (tissue mapping). We determined the imagined point of view for three commercially available intracoronary imaging systems used by invasive cardiologists and illustrate its importance in imaging modality validation.</p> <p>Methods and Results</p> <p>We made an asymmetric phantom and investigated it with two different intravascular ultrasound (IVUS) systems and one optical coherence tomography (OCT) system. The asymmetry of the phantom allowed determination of the spatial orientation of the cross-sectional images. On all tested systems, an observer should imagine herself/himself standing proximal to the cross-section when looking at the intravascular images.</p> <p>Conclusions</p> <p>The tested intracoronary imaging modalities displayed cross-sectional images with a spatial orientation corresponding to a proximal point of view. Knowledge of the spatial orientation is mandatory when comparing and validating different imaging modalities aimed at plaque characterization.</p

18Fluorodeoxyglucose Accumulation in Arterial Tissues Determined by PET Signal Analysis

BACKGROUND: Arterial 18fluorodeoxyglucose (FDG) positron emission tomography (PET) is considered a measure of atherosclerotic plaque macrophages and is used for quantification of disease activity in clinical trials, but the distribution profile of FDG across macrophages and other arterial cells has not been fully clarified. OBJECTIVES: The purpose of this study was to analyze FDG uptake in different arterial tissues and their contribution to PET signal in normal and atherosclerotic arteries. METHODS: Wild-type and D374Y-PCSK9 transgenic Yucatan minipigs were fed a high-fat, high-cholesterol diet to induce atherosclerosis and subjected to a clinical FDG-PET and computed tomography scan protocol. Volumes of arterial media, intima/lesion, macrophage-rich, and hypoxic tissues were measured in serial histological sections. Distributions of FDG in macrophages and other arterial tissues were quantified using modeling of the in vivo PET signal. In separate transgenic minipigs, the intra-arterial localization of FDG was determined directly by autoradiography. RESULTS: Arterial FDG-PET signal appearance and intensity were similar to human imaging. The modeling approach showed high accuracy in describing the FDG-PET signal and revealed comparable FDG accumulation in macrophages and other arterial tissues, including medial smooth muscle cells. These findings were verified directly by autoradiography of normal and atherosclerotic arteries. CONCLUSIONS: FDG is taken up comparably in macrophage-rich and -poor arterial tissues in minipigs. This offers a mechanistic explanation to a growing number of observations in clinical imaging studies that have been difficult to reconcile with macrophage-selective FDG uptake.This study was supported by the Danish Council for Independent Research/Medical Sciences, Lundbeck Foundation, Danish Heart Foundation, and Aarhus University Research Foundation (AU IDEAS). The CNIC is supported by the Ministerio de Ciencia, Innovación y Universidades, and the Pro CNIC Foundation; and is a Severo Ochoa Center of Excellence (SEV-2015-0505). Dr. Bentzon has served as a consultant for Novo Nordisk A/S; and has within the last 5 years received an investigator-initiated preclinical research grant from Regeneron PharmaceuticalsS

The High-Risk Plaque Initiative: Primary Prevention of Atherothrombotic Events in the Asymptomatic Population

The High-Risk Plaque (HRP) Initiative is a research and development effort to advance the understanding, recognition, and management of asymptomatic individuals at risk for a near-term atherothrombotic event such as myocardial infarction or stroke. Clinical studies using the newest technologies have been initiated, including the BioImage Study in which novel approaches are tested in a typical health plan population. Asymptomatic at-risk individuals were enrolled, including a survey-only group (n = 865), a group undergoing traditional risk factor scoring (n = 718), and a group in which all were assessed for both risk factors and subclinical atherosclerosis (n = 6104). The latter two groups underwent baseline examination in a dedicated mobile facility equipped with advanced imaging tools suitable for noninvasive screening for subclinical atherosclerosis (coronary artery calcium by computed tomography [CT], carotid and aortic disease by ultrasound, and ankle-brachial index). Selected participants were offered advanced imaging (contrast-enhanced CT, magnetic resonance imaging, and positron emission tomography/CT). Plasma, PAXgene RNA, and DNA samples were obtained for biomarker discovery studies. All individuals will be followed until 600 major atherothrombotic events have occurred in those undergoing imaging

Non-coronary atherosclerosis

During the last decades, the clinical and research interest in atherosclerosis has been mostly focused on coronary arteries. After the publications of the European Society Guidelines and AHA/ACC Guidelines on Peripheral artery diseases, and of the Registry REduction in Atherothrombosis for Continued Health Registry, there has been an increased interest in atherosclerosis of the lower extremity arteries and its presence in multifocal disease. However, awareness in the general population and the medical community of non-coronary artery diseases, and of its major prognostic implications remain relatively low. The aim of this general review stemming out of an ESC Working Group on Peripheral Circulation meeting in 2011 is to enhance awareness of this complex disease highlighting the importance of the involvement of atherosclerosis at different levels with respect to clinical presentation, diagnosis, and co-existence of the disease in the distinct arterial territories. We also emphasize the need of an interdisciplinary approach to face the broad and complex spectrum of multifocal disease, and try to propose a series of tentative recommendations and measures to be implemented in non-coronary atherosclerosi