Carotid plaque hemorrhage on magnetic resonance imaging strongly predicts recurrent ischemia and stroke

Abstract

ObjectiveThere is a recognized need to improve selection of patients with carotid artery stenosis for carotid endarterectomy (CEA). We assessed the value of magnetic resonance imaging (MRI)-defined carotid plaque hemorrhage (MRIPH) to predict recurrent ipsilateral cerebral ischemic events, and stroke in symptomatic carotid stenosis.MethodsOne hundred seventy-nine symptomatic patients with ≥50% stenosis were prospectively recruited, underwent carotid MRI, and were clinically followed up until CEA, death, or ischemic event. MRIPH was diagnosed if the plaque signal intensity was >150% that of the adjacent muscle. Event-free survival analysis was done using Kaplan–Meier plots and Cox regression models controlling for known vascular risk factors. We also undertook a meta-analysis of reported data on MRIPH and recurrent events.ResultsOne hundred fourteen patients (63.7%) showed MRIPH, suffering 92% (57 of 62) of all recurrent ipsilateral events and all but 1 (25 of 26) future strokes. Patients without MRIPH had an estimated annual absolute stroke risk of only 0.6%. Cox multivariate regression analysis proved MRIPH as a strong predictor of recurrent ischemic events (hazard ratio [HR] = 12.0, 95% confidence interval [CI] = 4.8–30.1, p < 0.001) and stroke alone (HR = 35.0, 95% CI = 4.7–261.6, p = 0.001). Meta-analysis of published data confirmed this association between MRIPH and recurrent cerebral ischemic events in symptomatic carotid artery stenosis (odds ratio = 12.2, 95% CI = 5.5–27.1, p < 0.00001).InterpretationMRIPH independently and strongly predicts recurrent ipsilateral ischemic events, and stroke alone, in symptomatic ≥50% carotid artery stenosis. The very low stroke risk in patients without MRIPH puts into question current risk–benefit assessment for CEA in this subgroup. ANN NEUROL 2013;73:774–784

CT Angiographic Features of Symptom-Producing Plaque in Moderate-Grade Carotid Artery Stenosis

“…Moreover, although carotid atherosclerosis is a dynamic process, prospective evidence supports high-risk markers of plaque, such as intraplaque hemorrhage, as being relatively stable with time and conferring increased stroke risk for at least 5 years after their detection. 5 An additional recent study 27 also showed that high-risk elements such as intraplaque hemorrhage, fibrous cap abnormalities, and lipid cores were generally not significantly changed during a 1-year follow-up period. Therefore, although further investigation is needed, it is reasonable to hypothesize that our results could translate into a prospective CTA-based stroke prediction tool in carotid artery disease.…”

“…The 2 main pathophysiologic mechanisms underlying stroke risk in carotid artery disease are the propensity of plaque to locally embolize 4,5 and downstream hemodynamic compromise (low flow). 4,6,7 Although hypoperfusion and resultant slow flow from carotid disease likely play a role in a subset of strokes occurring in carotid stenosis, plaque instability causing distal embolus may be a relatively more influential etiologic factor for stroke in carotid disease in general.…”

7.0 T MRI Detection of Cerebral Microinfarcts in Patients with a Symptomatic High-Grade Carotid artery Stenosis

“…1,2 Recent literature confirms that plaque characteristics may contribute to specify subgroups with an increased risk of (recurrent) ischemic cerebral events. [3][4][5] Moreover, the presence of infarcts in the brain parenchyma that downstream to these lesions may be important for accurate risk stratification. Patients with infarcts and cerebral symptoms were found to profit more from carotid endarterectomy (CEA), compared with patients with just ocular symptoms.…”

Intraplaque High-Intensity Signal on 3D Time-of-Flight MR Angiography Is Strongly Associated with Symptomatic Carotid Artery Stenosis

“…[4][5][6] One such component of carotid plaque that has been identified as a component of advanced atherosclerotic lesions is intraplaque hemorrhage (IPH). When present in carotid atherosclerotic plaque, IPH has been associated with previous 7,8 and future 9 stroke and has been proposed as a possible marker of not only plaque inflammation 10 but also of generalized cardiovascular risk.…”

“…4 However, a significant barrier to the widespread use of IPH assessment as a measure of embolic stroke risk has been that most studies have relied on high-resolution imaging by using specialized, dedicated MR imaging surface carotid coils 12 or black-blood coronal T1-weighted fat-suppressed MR imaging techniques. 9 Neither of these techniques are part of the standard sequences routinely obtained in MRA examinations, which rely on TOF techniques to assess luminal diameter stenosis. Recent reports have suggested that routinely performed MRA techniques used to measure stenosis, including 3D-TOF imaging, 13,14 can accurately predict IPH compared with histopathologic studies by the detection of intraplaque high-intensity signal (IHIS) relative to adjacent skeletal muscle.…”