Carotid Plaque Imaging in Acute Stroke (CAPIAS)

• Frequency and characteristics of vulnerable plaques (VP) in the carotid artery ipsilateral to an acute ischemic stroke (AIS) or TIA in the territory of the carotid artery in patients with a cryptogenic stroke [ Time Frame: Baseline ] [ Designated as safety issue: No ]

  For the primary outcome definition of a VP will be based on non-invasive high-resolution magnetic resonance imaging (MRI). Vulnerable plaques are defined as American Heart Association (AHA) class VI plaques (Cai et al. Circulation 2002; Saam et al.)

  Comparisons will include:

  • a comparison of the frequency and characteristics of VP ipsilateral vs. contralateral to the AIS or TIA
  • a comparison of the frequency and characteristics of ipsilateral VP in patients with cryptogenic stroke as compared to patients with cardioembolic stroke or small vessel stroke
  
  

• Pattern of acute ischemic lesions on brain MRI associated with VP in the carotid artery [ Time Frame: Baseline ] [ Designated as safety issue: No ]
  
• Recurrence rates of AIS or TIA in patients with VP in the carotid artery [ Time Frame: 12 Months ] [ Designated as safety issue: No ]
  
• Rate of new ischemic lesions on FLAIR MRI at 12 month follow-up in patients with VP in the carotid artery [ Time Frame: 12 Months ] [ Designated as safety issue: No ]
  
• Association between VP in the carotid artery and atherosclerotic plaques in the aortic arch as determined by transoesophageal ultrasound [ Time Frame: Baseline ] [ Designated as safety issue: No ]
  
• Biomarkers associated with vulnerable carotid artery plaques [ Time Frame: Baseline ] [ Designated as safety issue: No ]
  

Even with extensive diagnostic workup the underlying etiology remains unidentified in about 25% of patients with acute ischemic stroke (AIS) or transient ischemic attack (TIA). Non-invasive high-resolution magnetic resonance imaging (HR-MRI) of the carotid artery allows detecting vulnerable plaques (VP) and quantifying single plaque components. The hypotheses behind this study are that i) a substantial proportion of cases of AIS and TIA within the anterior circulation and no identified cause (cryptogenic AIS or TIA) are caused by VP in the carotid artery; ii) that these patients are at a high risk of developing a recurrent stroke, TIA, or clinically silent lesions detectable by brain MRI; and iii) that VP in the carotid artery are associated with specific infarct patterns as detected by diffusion-weighted MR imaging. Finally, the investigators will search for biomarkers associated with vulnerable carotid artery plaques. Motivating this study are the following considerations: i) data on the frequency and characteristics of VP in patients with cryptogenic AIS or TIA will provide valuable insights into stroke mechanisms; ii) depending on the results this study may have implications for diagnostic decision making and provide the basis for the planning of targeted interventional studies.