Carotid plaque surface echogenicity predicts cerebrovascular events: An Echographic Multicentric Swiss Study.

BACKGROUND AND PURPOSE: To determine the prognostic value for ischemic stroke or transitory ischemic attack (TIA) of plaque surface echogenicity alone or combined to degree of stenosis in a Swiss multicenter cohort METHODS: Patients with ≥60% asymptomatic or ≥50% symptomatic carotid stenosis were included. Grey-scale based colour mapping was obtained of the whole plaque and of its surface defined as the regions between the lumen and respectively 0-0.5, 0-1, 0-1.5, and 0-2 mm of the outer border of the plaque. Red, yellow and green colour represented low, intermediate or high echogenicity. Proportion of red color on surface (PRCS) reflecting low echogenictiy was considered alone or combined to degree of stenosis (Risk index, RI). RESULTS: We included 205 asymptomatic and 54 symptomatic patients. During follow-up (median/mean 24/27.7 months) 27 patients experienced stroke or TIA. In the asymptomatic group, RI ≥0.25 and PRCS ≥79% predicted stroke or TIA with a hazard ratio (HR) of respectively 8.7 p = 0.0001 and 10.2 p < 0.0001. In the symptomatic group RI ≥0.25 and PRCS ≥81% predicted stroke or TIA occurrence with a HR of respectively 6.1 p = 0.006 and 8.9 p = 0.001. The best surface parameter was located at 0-0.5mm. Among variables including age, sex, degree of stenosis, stenosis progression, RI, PRCS, grey median scale values and clinical baseline status, only PRCS independently prognosticated stroke (p = 0.005). CONCLUSION: In this pilot study including patients with at least moderate degree of carotid stenosis, PRCS (0-0.5mm) alone or combined to degree of stenosis strongly predicted occurrence of subsequent cerebrovascular events.

Embolic and Hemodynamic Transcranial Doppler Characteristics in Patients with Acute Ischemic Stroke due to Carotid Occlusive Disease: Contribution to the Different Infarct Patterns on MRI.

BACKGROUND AND PURPOSE: Whether hemodynamic and/or embolic transcranial Doppler (TCD) features of internal carotid artery (ICA) stenosis contribute to the classification of stroke patterns on MRI. PATIENTS AND METHODS: Consecutive patients presenting symptomatic ≥50% ICA stenosis were included. Microembolic signals (MES) detection and measurement of cerebral vasoreactivity (VR) were performed by TCD. Only acute MRI lesions, territorial (TT) and/or borderzone (BZ) were considered. RESULTS: A total of 72 ICA stenoses, 27 (38%) moderate (50-69%), and 45 (62%) high grade (70-99%) were included. MRI lesions showed 32 (44%) pure TT, 20 (28%) pure BZ, and 20 (28%) mixed TT and BZ. Impaired VR was found more frequently among patients with higher degrees of stenoses (P < .001) whereas MES were similarly encountered in both groups (P = NS). Impaired VR was more common in the BZ (10/20, 50%) than in the TT group (9/32, 28%, P < .1) while MES were present in 47% (15/32) of patients with TT and in 30% (6/20, P < .1) of those with BZ lesions, in particular in cortical BZ infarcts (P < .02). CONCLUSION: Our findings suggest that TCD characteristics of the ICA stenosis contribute to better define stroke patterns on MRI in about one-third of the patients presenting with pure TT or BZ lesions.

Accuracy of a novel risk index combining degree of stenosis of the carotid artery and plaque surface echogenicity.

BACKGROUND AND PURPOSE: The purpose of this study was to determine the accuracy of a risk index in symptomatic or asymptomatic carotid stenoses. METHODS: Consecutive patients presenting 50% to 99% carotid stenoses were included. A semiautomated gray scale-based color mapping (red, yellow, and green) of the whole plaque and of its surface was achieved. Surface was defined as the region located between the lumen (Level 0) and, respectively, 0.5, 1, 1.5, and 2 mm. Risk index was based on a combination of degree of stenosis and the proportion of the red color (reflecting low echogenicity) on the surface or on the whole plaque. RESULTS: There were 67 (36%) symptomatic and 117 (64%) asymptomatic carotid stenoses. Risk index values were higher among symptomatic stenoses (0.46 mean versus 0.29; P<0.0001); on receiver operating characteristic curves, risk index presented a stronger predictive power compared with degree of stenosis or surface echogenicity alone. Also, in a regression model including age, gender, degree of stenosis, surface echogenicity, gray median scale of the whole plaque, and risk index, risk index measured within the surface region located at 0.5 mm from the lumen was the only parameter significantly associated with the presence of symptoms (OR, 4.89; 95% CI, 2.7-8.7; P=0.0000002). The best criterion to differentiate between symptomatic and asymptomatic stenoses was a risk index value >0.36 (sensitivity and specificity of 78% and 65%, respectively). CONCLUSIONS: Risk index was significantly higher in the presence of symptoms and could therefore be a valuable tool to assess the clinical risk of a carotid plaque.

Stroke severity and residual flow determined by transcranial colour-coded ultrasound (TCCD) predict recanalization and clinical outcome during thrombolysis.

OBJECTIVE: To determine clinical, neuroradiological or ultrasonographic parameters associated with early recanalization and clinical outcome in patients treated with intravenous (IVT) or combined intravenous-intra-arterial (IVT-IAT) thrombolysis. METHODS: From 2004 to 2007, all consecutive ischemic stroke patients admitted within a 3-hour window and who underwent thrombolytic therapy were reviewed. Degree of occlusion and recanalization during IVT was assessed by transcranial color-coded ultrasound (TCCD) using Thrombolysis In Brain Ischemia (TIBI) classification. According to our protocol, in case of recanalization (modification of TIBI grade > or = 1) after 30 min of IVT, the procedure was maintained over 1h. When TIBI grade failed to improve after 30 min, IVT was discontinued and IAT performed using the remaining tPA dose. The study endpoints were early recanalization defined as achievement of TIBI > or = 3 grade at 30 min (for this endpoint all patients presenting a TIBI grade 3 at admission were excluded from the model) and clinical outcome at 3 months assessed by the modified Rankin scale. RESULTS: Seventy-one patients underwent either IVT (n=41) or IVT-IAT (n=30). Among all the variables, NIHSS and TIBI grades assessed at baseline were the only independent factors associated with early recanalization and clinical outcome. Furthermore, the combination of these two parameters was superior in predicting early recanalization and outcome to either one of them taken separately. An inverse correlation between NIHSS, TIBI grades and early recanalization was found: the lower the TIBI grade, the lower the probability to recanalize for any given NIHSS. CONCLUSION: Baseline NIHSS and TIBI grades were the only independent factors associated with early recanalization and clinical outcome. The combination of these two parameters was superior to each single variable in predicting the study endpoints and could therefore be used to improve the selection of patients for IVT or more aggressive therapies.

Intravenous versus combined (intravenous and intra-arterial) thrombolysis in acute ischemic stroke: a transcranial color-coded duplex sonography--guided pilot study.

BACKGROUND AND PURPOSE: Determine feasibility and safety of intravenous (IV) versus combined (IV-IA [intra-arterial]) thrombolysis guided by transcranial color-coded duplex sonography (TCCD). METHODS: Thirty-three patients eligible for IV thrombolysis, within 3 hours of onset of symptoms, with occlusion in middle cerebral artery territory (TCCD monitoring, thrombolysis in brain ischemia [TIBI] flow grade [0-3]), underwent IV thrombolysis (tissue plasminogen activator, 0.9 mg/kg). In case of recanalization (modification of TIBI score > or =1) after 30 minutes IV thrombolysis was continued over 1 hour; otherwise, it was discontinued, with subsequent IA thrombolysis. Recanalization was determined by TIBI (TCCD) and angiographically by thrombolysis in myocardial infarction (TIMI) flow grades. Clinical outcome measures were assessed at baseline, 24 hours (NIHSS) and 3 months (modified Rankin Scale). RESULTS: In the IV group, 10/17 patients (59%) with complete or partial recanalization after 30 minutes had a favorable outcome at 3 months (modified Rankin Scale 0 to 2). TIBI flow grades 3 to 5 after 30 minutes of IV thrombolysis predicted a good prognosis compared with TIBI grades 1 to 2 (P<0.05). In the combined IV/IA therapy group (no recanalization after 30 minutes), 9/16 patients (56%) had a favorable outcome at 3 months. One symptomatic intracerebral hemorrhage occurred in each group. CONCLUSIONS: Combined IV-IA versus IV thrombolysis guided by TCCD was feasible and safe. Recanalization after 30 minutes of IV thrombolysis led to a favorable outcome in 59% of the patients, provided TIBI flow grades were of 3 to 5. In the absence of early recanalization during IV thrombolysis, there was clinical benefit to proceed to IA therapy for a significative proportion of patients (56%).