Cargando…

Advanced ultrasound methods in assessment of carotid plaque instability: a prospective multimodal study

BACKGROUND: A significant proportion of ischemic strokes are caused by emboli from atherosclerotic, unstable carotid artery plaques. The selection of patients for endarterectomy in current clinical practice is primarily based on the degree of carotid artery stenosis and clinical symptoms. However, t...

Descripción completa

Detalles Bibliográficos
Autores principales: Zamani, M., Skagen, K., Scott, H., Russell, D., Skjelland, M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6990506/
https://www.ncbi.nlm.nih.gov/pubmed/31996153
http://dx.doi.org/10.1186/s12883-020-1620-z
_version_ 1783492514949365760
author Zamani, M.
Skagen, K.
Scott, H.
Russell, D.
Skjelland, M.
author_facet Zamani, M.
Skagen, K.
Scott, H.
Russell, D.
Skjelland, M.
author_sort Zamani, M.
collection PubMed
description BACKGROUND: A significant proportion of ischemic strokes are caused by emboli from atherosclerotic, unstable carotid artery plaques. The selection of patients for endarterectomy in current clinical practice is primarily based on the degree of carotid artery stenosis and clinical symptoms. However, the content of the plaque is known to be more important for stroke risk. Intraplaque neovascularization (IPN) has recently emerged as a possible surrogate marker for plaque instability. Neo-microvessels from the adventitial vasa vasorum grow into the full thickness of the vessel wall in an adaptive response to hypoxia, causing subsequent intraplaque haemorrhage and plaque rupture. Conventional ultrasound cannot detect IPN. Contrast-enhanced ultrasound and Superb Microvascular Imaging (SMI), have, however, shown promise in IPN assessment. Recent research using Shear Wave Elastography (SWE) has also reported reduced tissue stiffness in the artery wall (reduced mean Young’s modulus) in unstable compared to stable plaques. The purpose of this study is to identify unstable carotid artery plaques at risk of rupture and future ischemic stroke risk using multimodal assessments. METHODS: Forty five symptomatic and 45 asymptomatic patients > 18 years, with > 50% carotid stenosis referred to Oslo University Hospital ultrasound lab will be included in this on-going project. Patients will undergo contrast enhanced ultrasound, SMI, carotid-MRI and PET-((18)F-FDG). Contrast enhanced ultrasound will be analyzed semi-quantitatively (5-levels visual classification) and quantitatively by plotting time-intensity curve analyses to obtain plaque peak contrast enhancement intensity. Plaques removed at carotid endarterectomy will be assessed histologically and the number of microvessels, areas of inflammation, granulation, calcification, lipid and fibrosis will be measured. DISCUSSION: This multimodality study will primarily provide information on the clinical value of advanced ultrasound methods (SMI, SWE) for the detection of unstable carotid artery plaque in comparison with other methods including contrast-enhanced ultrasound, carotid-MRI and PET-((18)F-FDG) using histology as the gold standard. Secondly, findings from the methods mentioned above will be related to cerebrovascular symptoms, blood tests (leukocytes, CRP, ESR, lipoproteins and inflammatory markers) and cardiovascular risk factors at inclusion and at 1-year follow-up. The overall aim is to optimize detection of plaque instability which can lead to better preventive decisions and reduced stroke rate.
format Online
Article
Text
id pubmed-6990506
institution National Center for Biotechnology Information
language English
publishDate 2020
publisher BioMed Central
record_format MEDLINE/PubMed
spelling pubmed-69905062020-02-03 Advanced ultrasound methods in assessment of carotid plaque instability: a prospective multimodal study Zamani, M. Skagen, K. Scott, H. Russell, D. Skjelland, M. BMC Neurol Study Protocol BACKGROUND: A significant proportion of ischemic strokes are caused by emboli from atherosclerotic, unstable carotid artery plaques. The selection of patients for endarterectomy in current clinical practice is primarily based on the degree of carotid artery stenosis and clinical symptoms. However, the content of the plaque is known to be more important for stroke risk. Intraplaque neovascularization (IPN) has recently emerged as a possible surrogate marker for plaque instability. Neo-microvessels from the adventitial vasa vasorum grow into the full thickness of the vessel wall in an adaptive response to hypoxia, causing subsequent intraplaque haemorrhage and plaque rupture. Conventional ultrasound cannot detect IPN. Contrast-enhanced ultrasound and Superb Microvascular Imaging (SMI), have, however, shown promise in IPN assessment. Recent research using Shear Wave Elastography (SWE) has also reported reduced tissue stiffness in the artery wall (reduced mean Young’s modulus) in unstable compared to stable plaques. The purpose of this study is to identify unstable carotid artery plaques at risk of rupture and future ischemic stroke risk using multimodal assessments. METHODS: Forty five symptomatic and 45 asymptomatic patients > 18 years, with > 50% carotid stenosis referred to Oslo University Hospital ultrasound lab will be included in this on-going project. Patients will undergo contrast enhanced ultrasound, SMI, carotid-MRI and PET-((18)F-FDG). Contrast enhanced ultrasound will be analyzed semi-quantitatively (5-levels visual classification) and quantitatively by plotting time-intensity curve analyses to obtain plaque peak contrast enhancement intensity. Plaques removed at carotid endarterectomy will be assessed histologically and the number of microvessels, areas of inflammation, granulation, calcification, lipid and fibrosis will be measured. DISCUSSION: This multimodality study will primarily provide information on the clinical value of advanced ultrasound methods (SMI, SWE) for the detection of unstable carotid artery plaque in comparison with other methods including contrast-enhanced ultrasound, carotid-MRI and PET-((18)F-FDG) using histology as the gold standard. Secondly, findings from the methods mentioned above will be related to cerebrovascular symptoms, blood tests (leukocytes, CRP, ESR, lipoproteins and inflammatory markers) and cardiovascular risk factors at inclusion and at 1-year follow-up. The overall aim is to optimize detection of plaque instability which can lead to better preventive decisions and reduced stroke rate. BioMed Central 2020-01-29 /pmc/articles/PMC6990506/ /pubmed/31996153 http://dx.doi.org/10.1186/s12883-020-1620-z Text en © The Author(s). 2020 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Study Protocol
Zamani, M.
Skagen, K.
Scott, H.
Russell, D.
Skjelland, M.
Advanced ultrasound methods in assessment of carotid plaque instability: a prospective multimodal study
title Advanced ultrasound methods in assessment of carotid plaque instability: a prospective multimodal study
title_full Advanced ultrasound methods in assessment of carotid plaque instability: a prospective multimodal study
title_fullStr Advanced ultrasound methods in assessment of carotid plaque instability: a prospective multimodal study
title_full_unstemmed Advanced ultrasound methods in assessment of carotid plaque instability: a prospective multimodal study
title_short Advanced ultrasound methods in assessment of carotid plaque instability: a prospective multimodal study
title_sort advanced ultrasound methods in assessment of carotid plaque instability: a prospective multimodal study
topic Study Protocol
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6990506/
https://www.ncbi.nlm.nih.gov/pubmed/31996153
http://dx.doi.org/10.1186/s12883-020-1620-z
work_keys_str_mv AT zamanim advancedultrasoundmethodsinassessmentofcarotidplaqueinstabilityaprospectivemultimodalstudy
AT skagenk advancedultrasoundmethodsinassessmentofcarotidplaqueinstabilityaprospectivemultimodalstudy
AT scotth advancedultrasoundmethodsinassessmentofcarotidplaqueinstabilityaprospectivemultimodalstudy
AT russelld advancedultrasoundmethodsinassessmentofcarotidplaqueinstabilityaprospectivemultimodalstudy
AT skjellandm advancedultrasoundmethodsinassessmentofcarotidplaqueinstabilityaprospectivemultimodalstudy