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

BackgroundThe 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.Methods and ResultsOne 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).ConclusionsThe 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.

Age-Specific Sex Differences in Magnetic Resonance Imaging-Depicted Carotid Intraplaque Hemorrhage

“…9, 28–31 Since patients at our institution underwent imaging with neurovascular rather than surface coils, issues of coil sensitivity related to magnetic field inhomogeneity were not an issue. Experienced neuroradiologists (range of experience, 15 to 40 years) and a cardiothoracic radiologist with subspecialty and academic expertise in vascular biology imaging (A.R.M., experience, 27 years), routinely report the presence of IPH on the clinically acquired 3D T1-weighted GRE imaging acquisition.…”

Investigations of Carotid Stenosis to Identify Vulnerable Atherosclerotic Plaque and Determine Individual Stroke Risk

“…32 Results from the studies that included ≥50 patients are summarized in Table 3. [33][34][35][36][37][38] Although the hypothesis that MES denote solid emboli from a carotid plaque is physiologically plausible, it is not possible to prove this histologically, nor is it possible to know if an embolic signal originates from the carotid artery or from another embolic source, such as the aorta or the heart, unless one records simultaneously above and below the culprit plaque or multiple emboli are detected bilaterally, which makes a proximal source more likely. Nevertheless, if the presence of MES is a prognostic factor for ischemic stroke, TCD could be useful for identifying patients who are at increased risk.…”

Symptomatic Carotid Occlusion Is Frequently Associated With Microembolization

“…Among patients with carotid occlusion, emboli from the distal portion of the occluded vessel, 20 the proximal portion of the occlusion through external carotid artery collaterals (the original “stump emboli” hypothesis), 21 or from vasculature contralateral to the occlusion have all been reported. 22 Detection of MES has been associated with increased risk of future ischemia in both asymptomatic 23 and symptomatic 24, 25 carotid stenosis in some studies, highlighting the clinical importance of embolization and the validity of intracranial MES detection using TCD to identify debris or thrombus coming from more proximal carotid plaque. Clarifying the pathophysiology of cerebral ischemia in symptomatic carotid occlusion has the potential to guide treatment decisions.…”