Plaque at RISK (PARISK): Prospective Multicenter Study to Improve Diagnosis of High-Risk Carotid Plaques

BACKGROUND: Patients with symptomatic carotid artery stenosis are at high risk for recurrent stroke. To date, the decision to perform carotid endarterectomy in patients with a recent cerebrovascular event is mainly based on degree of stenosis of the ipsilateral carotid artery. However, additional atherosclerotic plaque characteristics might be better predictors of stroke, allowing for more precise selection of patients for carotid endarterectomy. AIMS AND HYPOTHESIS: We investigate the hypothesis that the assessment of carotid plaque characteristics with magnetic resonance imaging, multidetector-row computed tomography angiography, ultrasonography, and transcranial Doppler, either alone or in combination, may improve identification of a subgroup of patients with < 70% carotid artery stenosis with an increased risk of recurrent stroke. METHODS: The Plaque At RISK (PARISK) study is a prospective multicenter cohort study of patients with recent (<3 months) neurological symptoms due to ischemia in the territory of the carotid artery and < 70% ipsilateral carotid artery stenosis who are not scheduled for carotid endarterectomy or stenting. At baseline, 300 patients will undergo magnetic resonance imaging, multidetector-row computed tomography angiography, and ultrasonography examination of the carotid arteries. In addition, magnetic resonance imaging of the brain, ambulatory transcranial Doppler recording of the middle cerebral artery and blood withdrawal will be performed. After two-years, imaging will be repeated in 150 patients. All patients undergo a follow-up brain magnetic resonance imaging, and there will be regular clinical follow-up until the end of the study. STUDY OUTCOMES: The combined primary end-point contains ipsilateral recurrent ischemic stroke or transient ischemic attack or new ipsilateral ischemic brain lesions on follow-up brain magnetic resonance imaging.