Atherosclerosis is a chronic, systemic and progressive disease affecting different arterial blood vessels in the body. Atherosclerotic lesions silently progress from small plaques to severe stenosis and may remain asymptomatic for years. Unstable plaques and stenosis (also called vulnerable plaques), however, are prone to rupture leading to myocardial infarction, or stroke. The proliferation of the small arteries that are distributed to the outer and middle coats of the larger blood vessels (vasa vasorum) and within the atherosclerotic plaques (neovascularization) are inherently linked with the atherosclerotic plaque development, plaque inflammation and vulnerability. By injecting ultrasound contrast agents (microbubbles) into the blood stream, it is possible to detect this microcirculation of the vessel wall and the neovascularization within the atherosclerotic plaque using a contrast-enhanced ultrasound (CEUS) imaging technique. Particularly, CEUS of the carotid artery has been introduced as a non-invasive technique to improve detection of carotid atherosclerosis and to evaluate the presence of carotid plaque neovascularization which has emerged as a new marker for plaque vulnerability. The project investigates the predictive value of the detection of carotid plaque neovascularization on CEUS imaging in patients with asymptomatic carotid artery stenosis regarding the progression of the carotid atherosclerotic lesion and future vascular events including myocardial infarction, stroke or vascular intervention. The investigators hypothesize that neovascularization within the carotid lesion will significantly be more pronounced in patients with progressive carotid lesions and in patients suffering future vascular events during. The project will support the concept that intraplaque neovascularization is associated with plaque instability and vulnerability and therefore, the use of CEUS may provide an additional non-invasive, simple, safe, and reliable imaging modality to risk stratify individuals. The identification of vulnerable that are at increased risk of rupture by identification of intraplaque neovascularization is expected to improve the prediction of future vascular events and thus allow for better treatment selection. It will help the clinician to further risk stratify carotid stenosis. Particularly, it will help to identify unstable carotid stenosis that may already benefit from invasive therapy as carotid thromboendarterectomy and stenting.
Patients age > 18 years
Asymptomatic (no history of cerebrovascular event in the corresponding vessel territory) ≥30% carotid stenosis on standard carotid ultrasound
History of previous carotid endarterectomy or carotid stenting.
Heart failure (HYHA III or IV)
Myocardial infarction (<7d)
Severe pulmonal-arterial hypertension (pulmonal arterial pressure >90mmHg) based on clinical information (history of pulmonal arterial pressure, dyspnea on exertion New York Heart Association (NYHA) III and NYHA IV)
In-and out-patients referred to our ultrasound laboratory for carotid ultrasound for a clinical indication (preoperative, carotid murmur, known carotid lesion) will be ask to participate in this clinical study and will be asked to undergo study carotid ultrasound including CEUS.
Cohort
Prospective
Contrast enhanced carotid ultrasound
Diagnostic testVascular event or vascular intervention
The endpoint assessed will be the occurrence of any vascular event or vascular intervention. This composite end point includes any death of presumed vascular origin (fatal stroke, fatal myocardial infarction, sudden death, other vascular death), nonfatal stroke and TIA, nonfatal myocardial infarction, and any arterial vascular intervention that had not already been planned at the time of inclusion (eg, carotid surgery or angioplasty/stenting, coronary bypass, percutaneous coronary intervention, peripheral vascular surgery or angioplasty/stenting). All events and vascular interventions should be confirmed by hospital discharge report and medical files.
Progression of carotid stenosis over time
progression of carotid stenosis over time (progression in the lesion area, lesion volume, and degree of stenosis) assessed by yearly repeated standard carotid ultrasound study. Based on the yearly repeated standard carotid ultrasound studies progression rate of the lesion area and the lesion volume can be quantified for each stenosis and specify as continuous variable in cm2/year (area progression/year) and in cm3/year (volume progression/year). Additionally, the progression of the grade of stenosis will be quantified as categorical variable by determining the change of the stenosis category over time (30-49%, 50-69%, 70-99%, 100%) (Stable stenosis or increase in 1, 2, or 3 categories over 5 years).
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University Hospital, Basel, Switzerland
Lead sponsor
Swiss National Science Foundation
Collaborator
