title: Risk factors associated with cerebrovascular recurrence in symptomatic carotid disease: a comparative study of carotid plaque morphology, microemboli assessment and the European Carotid Surgery Trial risk model.
abstract: BACKGROUND
  The European Carotid Surgery Trial (ECST) risk model is a validated tool for predicting cerebrovascular risk in patients with symptomatic carotid disease. Carotid plaque hemorrhage as detected by MRI (MRIPH) and microembolic signals (MES) detected by transcranial Doppler (TCD) are 2 emerging modalities in assessing instability of the carotid plaque. The aim of this study was to assess the strength of association of MES and MRIPH with cerebrovascular recurrence in patients with symptomatic carotid artery disease in comparison with the ECST risk prediction model.
  
  
  RESULTS
  One hundred and thirty-four prospectively recruited patients (mean [SD]: age 72 [9.8] years, 33% female) with symptomatic severe (50% to 99%) carotid stenosis underwent preoperative TCD, MRI of the carotid arteries to assess MES, PH, and the ECST risk model. Patients were followed up until carotid endarterectomy, recurrent cerebral event, death, or study end. Event-free survival analysis was done using backward conditional Cox regression analysis.Of the 123 patients who had both TCD and MRI, 82 (66.7%) demonstrated PH and 46 (37.4%) had MES. 37 (30.1%) cerebrovascular events (21 transient ischemic attacks, 6 amaurosis fugax, and 10 strokes) were observed. Both carotid PH (HR=8.68; 95% CI 2.66 to 28.40, P<0.001) as well as MES (HR=3.28; 95% CI 1.68 to 6.42, P=0.001) were associated with cerebrovascular event recurrence. Combining MES and MRIPH improved the strength of association (HR=0.74, 95% CI 0.65 to 0.83; P<0.001). The ECST risk model was not associated with recurrence (HR=0.86; 95% CI 0.45 to 1.65; P=0.65).
  
  
  CONCLUSIONS
  The presence of carotid plaque hemorrhage is better associated with recurrent cerebrovascular events in patients with symptomatic severe carotid stenosis than the presence of microembolic signals; combining MES and MRIPH, further improves the association while the ECST risk score was insignificant.
authors.affiliation: Radiological Sciences, Division of Clinical Neurosciences, University of Nottingham, Nottingham, UK (N.A., N.K., A.H., D.A.) Department of Vascular and Endovascular Surgery, Queen's Medical Centre, Nottingham, UK (N.A., N.K., S.M.S.).
authors.forename: Nishath
authors.initials: N
authors.lastname: Altaf
authors.affiliation: Radiological Sciences, Division of Clinical Neurosciences, University of Nottingham, Nottingham, UK (N.A., N.K., A.H., D.A.) Department of Vascular and Endovascular Surgery, Queen's Medical Centre, Nottingham, UK (N.A., N.K., S.M.S.).
authors.forename: Neghal
authors.initials: N
authors.lastname: Kandiyil
authors.affiliation: Radiological Sciences, Division of Clinical Neurosciences, University of Nottingham, Nottingham, UK (N.A., N.K., A.H., D.A.).
authors.forename: Akram
authors.initials: A
authors.lastname: Hosseini
authors.affiliation: Medical Statistician, NIHR RDS for the East Midlands, Nottingham Health Science Partners, Queen's Medical Centre, University of Nottingham, Nottingham, UK (R.M.).
authors.forename: Rajnikant
authors.initials: R
authors.lastname: Mehta
authors.affiliation: Department of Vascular and Endovascular Surgery, Queen's Medical Centre, Nottingham, UK (N.A., N.K., S.M.S.).
authors.forename: Shane
authors.initials: S
authors.lastname: MacSweeney
authors.affiliation: Radiological Sciences, Division of Clinical Neurosciences, University of Nottingham, Nottingham, UK (N.A., N.K., A.H., D.A.).
authors.forename: Dorothee
authors.initials: D
authors.lastname: Auer
mesh_terms: D000368:Aged; D015415:Biomarkers; D016893:Carotid Stenosis / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D020766:Intracranial Embolism / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology; D020300:Intracranial Hemorrhages / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology; D053208:Kaplan-Meier Estimate; D018810:Magnetic Resonance Angiography; D008297:Male; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D020521:Stroke / Q000175:diagnosis / Q000209:etiology / Q000473:pathology; D017585:Ultrasonography, Doppler, Transcranial
chemical_list: D015415:Biomarkers
keywords: carotid arteries; cerebrovascular embolism; magnetic resonance imaging; relative risk; stroke