Intracranial atherosclerotic disease

Detectability of intracranial vessel wall atherosclerosis using black-blood spectral CT: a phantom and clinical study

BACKGROUND

Computed tomography (CT) is the usual modality for diagnosing stroke, but conventional CT angiography reconstructions have limitations.

METHODS

A phantom with tubes of known diameters and wall thickness was scanned for wall detectability, wall thickness, and contrast-to-noise ratio (CNR) on conventional and spectral black-blood (SBB) images. The clinical study included 34 stroke patients. Diagnostic certainty and conspicuity of normal/abnormal intracranial vessels using SBB were compared to conventional. Sensitivity/specificity/accuracy of SBB and conventional were compared for plaque detectability. CNR of the wall/lumen and quantitative comparison of remodeling index, plaque burden, and eccentricity were obtained for SBB imaging and high-resolution magnetic resonance imaging (hrMRI).

RESULTS

The phantom study showed improved detectability of tube walls using SBB (108/108, 100% versus conventional 81/108, 75%, p < 0.001). CNRs were 75.9 ± 62.6 (mean ± standard deviation) for wall/lumen and 22.0 ± 17.1 for wall/water using SBB and 26.4 ± 15.3 and 101.6 ± 62.5 using conventional. Clinical study demonstrated (i) improved certainty and conspicuity of the vessels using SBB versus conventional (certainty, median score 3 versus 0; conspicuity, median score 3 versus 1 (p < 0.001)), (ii) improved sensitivity/specificity/accuracy of plaque (≥ 1.0 mm) detectability (0.944/0.981/0.962 versus 0.239/0.743/0.495) (p < 0.001), (iii) higher wall/lumen CNR of SBB of (78.3 ± 50.4/79.3 ± 96.7) versus hrMRI (18.9 ± 8.4/24.1 ± 14.1) (p < 0.001), and (iv) excellent reproducibility of remodeling index, plaque burden, and eccentricity using SBB versus hrMRI (intraclass correlation coefficient 0.85-0.94).

CONCLUSIONS

SBB can enhance the detectability of intracranial plaques with an accuracy similar to that of hrMRI.

RELEVANCE STATEMENT

This new spectral black-blood technique for the detection and characterization of intracranial vessel atherosclerotic disease could be a time-saving and cost-effective diagnostic step for clinical stroke patients. It may also facilitate prevention strategies for atherosclerosis.

KEY POINTS

• Blooming artifacts can blur vessel wall morphology on conventional CT angiography. • Spectral black-blood (SBB) images are generated from material decomposition from spectral CT. • SBB images reduce blooming artifacts and noise and accurately detect small plaques.

Epidemiology, Pathophysiology, and Imaging of Atherosclerotic Intracranial Disease

Intracranial atherosclerotic disease (ICAD) is one of the most common causes of stroke worldwide. Among people with stroke, those of East Asia descent and non-White populations in the United States have a higher burden of ICAD-related stroke compared with Whites of European descent. Disparities in the prevalence of asymptomatic ICAD are less marked than with symptomatic ICAD. In addition to stroke, ICAD increases the risk of dementia and cognitive decline, magnifying ICAD societal burden. The risk of stroke recurrence among patients with ICAD-related stroke is the highest among those with confirmed stroke and stenosis ≥70%. In fact, the 1-year recurrent stroke rate of >20% among those with stenosis >70% is one of the highest rates among common causes of stroke. The mechanisms by which ICAD causes stroke include plaque rupture with in situ thrombosis and occlusion or artery-to-artery embolization, hemodynamic injury, and branch occlusive disease. The risk of stroke recurrence varies by the presumed underlying mechanism of stroke, but whether techniques such as quantitative magnetic resonance angiography, computed tomographic angiography, magnetic resonance perfusion, or transcranial Doppler can help with risk stratification beyond the degree of stenosis is less clear. The diagnosis of ICAD is heavily reliant on lumen-based studies, such as computed tomographic angiography, magnetic resonance angiography, or digital subtraction angiography, but newer technologies, such as high-resolution vessel wall magnetic resonance imaging, can help distinguish ICAD from stenosing arteriopathies.

Multimodal imaging approach for the diagnosis of intracranial atherosclerotic disease (ICAD): Basic principles, current and future perspectives

PURPOSE

To review the different imaging modalities utilized in the diagnosis of Intracranial Atherosclerotic Disease (ICAD) including their latest development and relevance in management of ICAD.

METHODS

A review of the literature was conducted through a search in google scholar, PubMed/Medline, EMBASE, Scopus, clinical trials.gov and the Cochrane Library. Search terms included, "imaging modalities in ICAD," "ICAD diagnostic," "Neuroimaging of ICAD," "Evaluation of ICAD". A summary and comparison of each modality's basic principles, advantages and disadvantages were included.

RESULTS

A total of 144 articles were identified and reviewed. The most common imaging used in ICAD diagnoses were DSA, CTA, MRA and TCD. They all had proven accuracy, their own benefits, and limitations. Newer modalities such as VWI, IVUS, OCT, PWI and CFD provide more detailed information regarding the vessel walls, plaque characteristics, and flow dynamics, which play a tremendous role in treatment guidance. In certain clinical scenarios, using more than one modality has been shown to be helpful in ICAD identification. The rapidly evolving software related to imaging studies, such as virtual histology, are very promising for the diagnostic and management of ICAD.

CONCLUSIONS

ICAD is a common cause of recurrent ischemic stroke. Its management can be both medical and/or procedural. Many different imaging modalities are used in its diagnosis. In certain clinical scenario, a combination of two more modalities can be critical in the management of ICAD. We expect that continuous development of imaging technique will lead to individualized and less invasive management with adequate outcome.

The value of coordinated analysis of multimodal atherosclerotic plaque imaging in the assessment of cardiovascular and cerebrovascular events

Background

Although atherosclerosis (AS) can affect multiple vascular beds, previous studies have focused on the analysis of single-site AS plaques.

Objective

The aim of this study is to explore the differences or similarities in the characteristics of atherosclerotic plaque found in the internal carotid artery, cerebral artery, and coronary artery between patients with atherosclerotic cardiovascular disease (ASCVD) and those without events.

Methods

Patients aged ≥ 18 years who underwent both high-resolution vessel wall imaging (HR-VWI) and coronary computed tomography angiography (CCTA) were retrospectively collected and categorized into the ASCVD group and the non-event group. The plaques were then categorized into culprit plaques, non-culprit plaques, and non-event plaques. Plaque morphological data such as stenosis, stenosis grades, plaque length (PL), plaque volume (PV), minimal lumen area (MLA), enhancement grade, and plaque composition data such as calcified plaque volume (CPV), fibrotic plaque volume (FPV), fibro-lipid plaque volume (FLPV), lipid plaque volume (LPV), calcified plaque volume ratio (CPR), fibrotic plaque volume ratio (FPR), fibro-lipid plaque ratio (FLPR), lipid plaque volume ratio (LPR), intraplaque hemorrhage volume (IPHV), and intraplaque hemorrhage volume ratio (IPHR)were recorded and analyzed.

Results

A total of 44 patients (mean age 66 years, SD 9 years, 28 men) were included. In cervicocephalic plaques, the ASCVD group had more severe stenosis grades (p = 0.030) and demonstrated significant differences in LPV, LPR, and CPV (p = 0.044, 0.030, 0.020) compared with the non-event group. In coronary plaques, the ASCVD group had plaques with greater stenosis (p < 0.001), more severe stenosis grades (p < 0.001), larger volumes (p = 0.001), longer length (p = 0.008), larger FLPV (p = 0.012), larger FPV (p = 0.002), and higher FPR (p = 0.043) compared with the non-event group. There were significant differences observed in stenosis (HR-VWI, CCTA: p < 0.001, p < 0.001), stenosis grades (HR-VWI, CCTA: p < 0.001, p < 0.001), plaque length (HR-VWI, CCTA: p = 0.028, p < 0.001), and plaque volume (HR-VWI, CCTA: p = 0.013, p = 0.018) between the non-event plaque, non-culprit plaque, and culprit plaque. In the image analysis of HR-VWI, there were differences observed between IPHR (p < 0.001), LPR (p = 0.001), FPV (p = 0.011), and CPV (p = 0.015) among the three groups of plaques. FLPV and FPV were significantly different among the three different plaque types from the coronary artery (p = 0.043, p = 0.022).

Conclusion

There is a consistent pattern of change in plaque characteristics between the cervicocephalic and coronary arteries in the same patient.

Investigating the relationship between intracranial atherosclerotic plaque remodelling and diabetes using high-resolution vessel wall imaging

BACKGROUND

Intracranial atherosclerosis, a leading cause of stroke, involves arterial plaque formation. This study explores the link between plaque remodelling patterns and diabetes using high-resolution vessel wall imaging (HR-VWI).

AIM

To investigate the factors of intracranial atherosclerotic remodelling patterns and the relationship between intracranial atherosclerotic remodelling and diabetes mellitus using HR-VWI.

METHODS

Ninety-four patients diagnosed with middle cerebral artery or basilar artery atherosclerosis were enrolled. Their basic clinical data were collected, and HR-VWI was performed. The vascular area at the plaque (VAMLN) and normal reference vessel (VAreference) were delineated and measured using image postprocessing software, and the Remodelling index (RI) was calculated. According to the value of the RI, the patients were divided into a positive remodelling (PR) group, intermediate remodelling (IR) group, negative remodelling (NR) group, PR group and non-PR (N-PR) group.

RESULTS

The PR group exhibited a higher prevalence of diabetes and serum cholesterol levels than the IR and NR groups [45.2%, 4.54 (4.16, 5.93) vs 25%, 4.80 ± 1.22 and 16.4%, 4.14 (3.53, 4.75), respectively, P < 0.05]. The diabetes incidence was also significantly greater in the PR group than in the N-PR group (45.2% vs 17.5%, P < 0.05). Furthermore, the PR group displayed elevated serum triglyceride and cholesterol levels compared to the N-PR group [1.64 (1.23, 2.33) and 4.54 (4.16, 5.93) vs 4.54 (4.16, 5.93) and 4.24 (3.53, 4.89), P < 0.05]. Logistic regression analysis revealed diabetes mellitus as an independent influencing factor in plaque-PR [odds ratio (95% confidence interval): 3.718 (1.207-11.454), P < 0.05].

CONCLUSION

HR-VWI can clearly show the morphology and signal characteristics of intracranial vascular walls and plaques. Intracranial atherosclerotic plaques in diabetic patients are more likely to show PR, suggesting poor plaque stability and a greater risk of stroke.

Multimodal MRI study of the relationship between plaque characteristics and hypoperfusion in patients with transient ischemic attack

Objective

Transient ischemic attack is a significant risk factor for acute cerebral infarction. Previous studies have demonstrated that hypoperfusion in patients with transient ischemic attack was associated with the recurrence of transient ischemic attack, stroke, and persistent worsening of neurological symptoms. Moreover, transient ischemic attack patients classified as high-risk group according to the ABCD2 score have a higher incidence of stroke. Therefore, the objective of this study was to investigate the plaque characteristics of transient ischemic attack patients with concomitant cerebral hypoperfusion using multimodal MRI, as well as hemodynamic changes in the high-risk group with transient ischemic attack patients.

Materials and methods

A total of 151 patients with transient ischemic attack were prospectively recruited for this study. All enrolled patients underwent multimodal MRI, including DWI, TOF-MRA, HR-VWI, and DSC-PWI. Finally, 56 patients met the inclusion criteria. Based on DSC-PWI images, patients were divided into two groups: hypoperfusion (n = 41) and non-hypoperfusion (n = 15). Clinical baseline characteristics and plaque characteristics were analyzed between the two groups. Furthermore, within the hypoperfusion group, patients were further classified into low-risk (n = 11) and high-risk (n = 30) subgroups based on the ABCD2 score. Hemodynamic differences between these subgroups were also analyzed.

Results

Compared with the non-hypoperfusion group, the hypoperfusion group had a significantly higher prevalence of hypertension (68.3% vs. 33.3%, p = 0.019) and hyperhomocysteinemia (65.9% vs. 33.3%, p = 0.029). Moreover, the hypoperfusion group exhibited more significant luminal stenosis degree [41.79 ± 31.36 vs. 17.62± 13.62, p = 0.006] and greater NWI (57.1%± 20.47% vs. 40.21%± 21.56%, p = 0.009) compared to the non-hypoperfusion group. In addition, the high-risk group identified by the ABCD2 score had a higher rMTT [117.6(109.31-128.14) vs. 108.36(100.67-119.92), p = 0.037].

Conclusion

Transient ischemic attack patients with hypoperfusion exhibited a higher prevalence of hypertension and hyperhomocysteinemia, as well as higher luminal stenosis degree, and greater NWI. Furthermore, Transient ischemic attack patients in the high-risk group demonstrated higher MTT.

Association between glycated hemoglobin and functional outcomes in patients with intracranial large artery atherosclerotic disease-related acute ischemic stroke: identifying the magic number

Objective

This study aimed to investigate the effect of the glycated hemoglobin A1c (HbA1c) level on the functional outcome (FOC) in patients with intracranial large artery atherosclerotic disease (ICLAD)-related acute ischemic stroke (AIS).

Methods

This retrospective study enrolled patients with ICLAD-related AIS who were admitted to King Fahd University Hospital between January 2017 and September 2021. Patients were divided into two groups based on the optimal cutoff HbA1c level determined using receiver operating characteristic curve analysis-those with HbA1c ≤6.9% and those with HbA1c >6.9%. Demographic and other clinical characteristics were compared between the two groups using chi-square tests. The association between HbA1c and 90-day FOC was assessed using the chi-square test and odds ratios (ORs). Multivariate analysis was performed to adjust for confounding factors.

Results

A total of 140 patients were included in the analysis. A significant association was observed between the HbA1c level and FOC. Compared to patients with HbA1c ≤6.9%, patients with HbA1c >6.9% were more likely to have an unfavorable FOC [p = <0.001, OR = 2.05, 95% confidence interval (CI) = 1.33-3.14]. The association between HbA1c >6.9% and unfavorable FOC was sustained even after adjusting for confounding factors (p = 0.008) and atherosclerosis risk factors (p = 0.01). HbA1c >6.9% was also associated with higher ORs for in-hospital complications (p = 0.06, OR = 1.34, 95% CI = 1.02-1.77) and mortality (p = 0.07, OR = 1.42, 95% CI = 1.06-1.92) although these associations did not attain significant p-values.

Conclusion

HbA1c >6.9% was significantly associated with unfavorable FOC in ICLAD-related AIS. However, further studies with larger sample sizes are required to verify whether HbA1c is an independent predictor of poor FOC. Nevertheless, targeting HbA1c <7% should be the goal of physicians when managing patients at high risk of ICLAD.

Thirty-Day Outcomes of Resolute Onyx Stent for Symptomatic Intracranial Stenosis: A Multicenter Propensity Score-Matched Comparison With Stenting Versus Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis Trial

BACKGROUND

Symptomatic intracranial atherosclerotic disease (sICAD) is estimated to cause 10% of strokes annually in the United States. However, treatment remains a challenge with several different stenting options studied in the past with unfavorable results.

OBJECTIVE

To report the 30-day stroke and/or death rate associated with intracranial stent placement for sICAD using Resolute Onyx Zotarolimus-Eluting Stent (RO-ZES) and provide a comparison with the results of Stenting Versus Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial.

METHODS

Prospectively maintained databases across 8 stroke centers were used to identify adult patients treated with RO-ZES for sICAD between January 2019 and December 2021. Primary end point was composite of 30-day stroke, intracerebral hemorrhage, and/or death. Propensity score matching was performed using age, hypertension, lipid disorder, cigarette smoking, and symptomatic target vessel to create a matched group for comparison between RO-ZES and the SAMMPRIS medical management and treatment groups (SAMMPRIS percutaneous angioplasty and stenting [S-PTAS]).

RESULTS

A total of 132 patients met the inclusion criteria for analysis (mean age: 64.2 years). Mean severity of stenosis was 81.4% (±11.4%). A total of 4 (3.03%) stroke and/or deaths were reported within 30 days of treatment in the RO-ZES group compared with 6.6% in the SAMMPRIS medical management group (OR [odds ratio] 2.26, 95% CI 0.7-9.56, P = .22) and 15.6% in the S-PTAS group (OR 5.9, 95% CI 2.04-23.4, P < .001). Propensity score match analysis of 115 patients in each group demonstrated 30-day stroke and/or death rate of 2.6% in the RO-ZES group and 15.6% in the S-PTAS group (OR 6.88, 95% CI 1.92-37.54, P < .001).

CONCLUSION

Patients treated with RO-ZES had a relatively low 30-day stroke and/or death rate compared with the S-PTAS group. Further large-scale prospective studies are warranted to evaluate the safety and efficacy of RO-ZES for the treatment of sICAD.

Association between carotid atherosclerosis and presence of intracranial atherosclerosis using three-dimensional high-resolution vessel wall magnetic resonance imaging in asymptomatic patients with type 2 diabetes

AIMS

Carotid atherosclerosis (CAS) is associated with a high risk of cardiovascular diseases. We aimed to investigate whether CAS is associated with the presence of intracranial atherosclerosis (ICAS).

METHODS

A total of 69 asymptomatic patients with type 2 diabetes (36 with CAS and 33 without CAS) who were free of cerebrovascular disease were enrolled in this case-control study. CAS was defined as a mean carotid intima-media thickness ≥ 1.0 mm or carotid plaque. The presence of ICAS was identified using three-dimensional high-resolution vessel wall magnetic resonance imaging.

RESULTS

There was no difference between the case and control groups in baseline characteristics, such as age, the proportion of men, duration of diabetes, and other cardiometabolic risk factors. The prevalence of ICAS was significantly higher in patients with CAS than those without CAS (72.2 % vs 48.5 %, P = 0.044). CAS was significantly associated with the presence of ICAS, even after adjusting other covariates (odds ratio [OR], 3.19; 95 % confidence interval [CI] 1.09-9.33, P = 0.034). In addition, CAS was significantly associated with the presence of multiple ICAS lesions (OR, 5.57; 95 % CI 1.75-17.78, P = 0.004).

CONCLUSIONS

CAS is significantly and independently associated with the presence and extent of ICAS in asymptomatic patients with type 2 diabetes.

Prevalence of Intracranial Atherosclerotic Disease in Patients with Low-Risk Transient or Persistent Neurologic Events

BACKGROUND AND PURPOSE

There are limited data on the prevalence and outcome of intracranial atherosclerotic disease in patients with low-risk transient or persistent minor neurologic events. We sought to determine the prevalence and risk factors associated with intracranial atherosclerotic disease in patients with low-risk transient or persistent neurologic events.

MATERIALS AND METHODS

Participants with available intracranial vascular imaging from the Diagnosis of Uncertain-Origin Benign Transient Neurologic Symptoms (DOUBT) study, a large prospective multicenter cohort study, were included in this post hoc analysis. The prevalence of intracranial atherosclerotic disease of ≥50% was determined, and the association with baseline characteristics and DWI lesions was evaluated using logistic regression.

RESULTS

We included 661 patients with a median age of 62 years (interquartile range, 53-70 years), of whom 53% were women. Intracranial atherosclerotic disease was found in 81 (12.3%) patients; asymptomatic intracranial atherosclerotic disease alone, in 65 (9.8%); and symptomatic intracranial atherosclerotic disease, in 16 (2.4%). The most frequent location was in the posterior cerebral artery (29%). Age was the only factor associated with any intracranial atherosclerotic disease (adjusted OR, 1.9 for 10 years increase; 95% CI, 1.6-2.5). Multivariable logistic regression showed a strong association between intracranial atherosclerotic disease and the presence of acute infarct on MR imaging (adjusted OR, 3.47; 95% CI, 1.91-6.25).

CONCLUSIONS

Intracranial atherosclerotic disease is not rare in patients with transient or persistent minor neurologic events and is independently associated with the presence of MR imaging-proved ischemia in this context. Evaluation of the intracranial arteries could be valuable in establishing the etiology of such low-risk events.

The feasibility of non-contrast-enhanced zero echo time magnetic resonance angiography for characterization of intracranial atherosclerotic disease

Background

Accurate and non-invasive assessment of intracranial atherosclerotic disease (ICAD) is important because of its effect on treatment planning. The aim of this study is to investigate if zero echo time (zTE) magnetic resonance angiography (zTE-MRA) is feasible in the characterization of ICAD.

Methods

A total of 175 patients with ICAD were recruited. ZTE-MRA and time-of-flight (TOF)-MRA sequences were conducted for all participants using a 3T clinical MR system. Forty-one patients also underwent digital subtraction angiography (DSA), and were confirmed to have intracranial arterial stenosis (ICAS). Weighted kappa (κ) statistics were used to assess the inter-observer agreement and diagnostic consistency of both zTE- and TOF-MRA, using DSA as a reference. The Wilcoxon signed-rank test was used to evaluate differences in image quality between zTE- and TOF-MRA images. The nonparametric test of multiple paired samples was used to compare the results of vascular stenosis diagnosis between zTE-, TOF-MRA and DSA.

Results

Supported by high inter-observer agreement (weighted κ=0.78), zTE-MRA generated significantly higher scores than TOF-MRA for susceptibility artifact signal (mean: 3.03±0.98 vs. 2.72±1.09; P=0.017) and flow signal in parent artery (mean: 3.63±0.49 vs. 3.07±0.82; P<0.001). Additionally, zTE-MRA showed more robust diagnostic performance than TOF-MRA for patients with ICAD and degree of vascular stenosis (P<0.05), and was highly consistent with reference DSA images (weighted κ=0.80).

Conclusions

ZTE-MRA has potential for use as a routine clinical method for patients with ICAD.

Molecular Biomarkers Associated with Early-Onset Symptomatic Intracranial Atherosclerosis

Purpose

Previous studies have shown a rising incidence of early-onset symptomatic intracranial atherosclerosis (sICAS), which has brought a severe economic burden to social development. This study aimed to evaluate the molecular biomarkers associated with early-onset sICAS and to seek possible intervention strategies for early prevention.

Patients and Methods

We consecutively recruited patients with sICAS and divided them into two groups based on age: early-onset sICAS group as age ≤60 years old and late-onset sICAS group as age >60 years old. We collected and compared the demographic data and laboratory results of each group. A bivariate logistic regression model was applied to evaluate the independent molecular biomarkers of early-onset sICAS.

Results

A total of 1007 subjects with sICAS were enrolled in this study, comprising 519 patients in the early-onset sICAS group and 488 patients in the late-onset sICAS group. Bivariate logistic regression analysis demonstrated an increased level of white blood cell, platelet, albumin globulin ratio, free triiodothyronine, and a decreased level of total bile acid, urea nitrogen, high-density lipoprotein, homocysteine, and fibrinogen in the early-onset sICAS group when compared to the late-onset group.

Conclusion

Our study showed the relevance between early sICAS and circulating levels of different molecular biomarkers. Detection of these related molecular biomarkers may provide a simple way for early sICAS preventions in the future.

Imaging Parameters Predict Recurrence After Transient Ischemic Attack or Minor Stroke Stratified by ABCD2 Score

BACKGROUND AND PURPOSE

Whether imaging parameters would independently predict stroke recurrence in low-risk minor ischemic stroke (MIS) or transient ischemic attack (TIA) according to traditional score system (such as ABCD² score, which was termed on the basis of the initials of the five factors: age, blood pressure, clinical features, duration, diabetes) remains unclear. We sought to evaluate the association between imaging parameters and 1-year stroke recurrence in patients with TIA or MIS in different risk stratum stratified by ABCD² score.

METHODS

We included patients with TIA and MIS (National Institutes of Health Stroke Scale score ≤3) with complete baseline vessel and brain imaging data from the Third China National Stroke Registry III. Patients were categorized into different risk groups based on ABCD² score (low risk, 0-3; moderate risk, 4-5; and high risk, 6-7). The primary outcome was stroke recurrence within 1 year. Multivariable Cox proportional-hazards regression models were used to assess whether imaging parameters (large artery stenosis, infarction number) were independently associated with stroke recurrence.

RESULTS

Of the 7140 patients included, 584 patients experienced stroke recurrence within 1 year. According to the ABCD² score, large artery stenosis was associated with higher stroke recurrence in both low-risk (adjusted hazard ratio, 1.746 [95% CI, 1.200-2.540]) and moderate-risk group (adjusted hazard ratio, 1.326 [95% CI, 1.042-1.687]) but not in the high-risk group (P>0.05). Patients with multiple acute infarctions or single acute infarction had a higher risk of recurrent stroke than those with no infarction in both low- and moderate-risk groups, but not in the high-risk group.

CONCLUSIONS

Large artery stenosis and infarction number were independent predictors of 1-year stroke recurrence in low-moderate risk but not in high-risk patients with TIA or MIS stratified by ABCD² score. This finding emphasizes the importance of early brain and vascular imaging evaluation for risk stratification in patients with TIA or MIS.

Acute ischemic stroke versus transient ischemic attack: Differential plaque morphological features in symptomatic intracranial atherosclerotic lesions

BACKGROUND AND AIMS

Intracranial atherosclerotic disease (ICAD) is a major etiologic cause for acute ischemic stroke (AIS) and transient ischemic attack (TIA). The study was designed to investigate if differential morphological features exist in symptomatic atherosclerotic lesions between AIS and TIA patients.

METHODS

The culprit plaques from 45 AIS patients and 42 TIA patients were analyzed for the degree of stenosis, vessel wall irregularity, normalized wall index (NWI), remodeling index, plaque-wall contrast ratio (CR), high signal intensity on T1-weighted images, plaque enhancement ratio and enhancement grade. These plaque features along with clinical characteristics were compared between AIS and TIA groups as well as between their stenosis degree-matched subgroups.

RESULTS

Overall, grade 2 enhancement (OR 3.85, 95%CI 1.42-10.46, p = 0.006) and hyperlipidemia (OR 3.04, 95%CI 1.13-8.22, p = 0.025) were independent indicators for AIS, whereas high NWI (OR 1.47, 95%CI 0.76-2.86, p = 0.004) was associated with TIA. In the comparison between the subgroups with moderate (30%-69%) stenosis, high plaque-wall CR (OR 5.38, 95%CI 1.39-20.75, p = 0.008) was associated with AIS, whereas high NWI (OR 2.50, 95%CI 0.61-10.00, p = 0.006) was associated with TIA.

CONCLUSIONS

Our study reveals differential morphological features in symptomatic ICAD lesions between AIS and TIA patients. Probing these features with MR vessel wall imaging may provide insights into the prognosis of patients with ICAD.

Transcranial Doppler and magnetic resonance angiography assessment of intracranial stenosis: An analysis of screening modalities

BACKGROUND:

Time-of-flight (TOF) magnetic resonance angiography (MRA) of the head and transcranial Doppler (TCD) are used to diagnose intracranial stenosis, an important cause of ischemic stroke. We aimed to compare TCD findings with TOF-MRA results in a population of patients with symptoms of cerebrovascular disease in whom both tests were done within a short intervening period of each other.

METHODS:

This is a retrospective, single-center study. Among adult patients referred for symptoms of cerebrovascular disease in both outpatient and inpatient settings, those who received a TCD with adequate insonation of all intracranial arteries and underwent MRA within 3 months intervals of TCD were included in this study. We evaluated the agreement between the results of these two modalities, and also assessed sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of TCD through receiver-operating characteristic (ROC) curve analysis, while MRA considered as a comparator.

RESULTS:

Among eighty included patients, 720 arteries were examined. An overall significant agreement of 96.5% was observed between TCD and MRA (Kappa = 0.377, P < 0.001). Compared to MRA, TCD had sensitivity of 42.1%, specificity of 99.6%, PPV of 72.7%, and NPV of 98.4% (ROC area: 0.708 [0.594–0.822]). TCD is specifically accurate in evaluating middle cerebral artery (MCA) (ROC area = 0.83).

CONCLUSIONS:

The high NPV of TCD in our study indicates the utility of TCD as a diagnostic test to exclude the presence of intracranial stenosis. This study supports TCD as a convenient, safe, and reproducible imaging modality applicable in the screening of intracranial stenosis, especially to evaluate MCA.

Kongcun Town Asymptomatic Intracranial Artery Stenosis study in Shandong, China: cohort profile

PURPOSE

The population-based Kongcun Town Asymptomatic Intracranial Artery Stenosis (KT-aICAS) study aims to investigate the prevalence of aICAS and major cardiovascular risk factors (CRFs) or biomarkers related to the development and prognosis of aICAS.

PARTICIPANTS

The KT-aICAS study included 2311 rural residents who were aged ≥40 years and living in Kongcun Town, Shandong Province, China. Baseline examination was conducted from October 2017 to October 2018, during which information on demographics, socioeconomics, personal and family medical history, and lifestyle factors was collected through face-to-face interviews, physical examination and blood tests. aICAS was initially screened using transcranial Doppler examination and then diagnosed using magnetic resonance angiography. Atherosclerosis in carotid arteries was diagnosed via carotid ultrasonography. High-resolution MRI was further used to evaluate the vessel wall of aICAS. Neuropsychological assessments were performed in the participants diagnosed with aICAS and the age-matched and sex-matched controls.

FINDINGS TO DATE

Of the 2311 participants, 2027 (87.7%) completed the diagnostic procedure and aICAS was detected in 154 persons, resulting in an overall prevalence of 7.6%. The prevalence of aICAS increased with advancing age from 5.1% in participants aged 40-49 years to 12.7% in those aged ≥70 years (p<0.001). aICAS was detected in 305 intracranial arteries, including 221 (72.5%) in the anterior circulation and 84 (27.5%) in the posterior circulation (p<0.001). In addition, major CRFs were highly prevalent among middle-aged and elderly rural dwellers who were free of clinical stroke.

FUTURE PLANS

Follow-up examinations will be performed every 3 years following the baseline examination. This study will increase our knowledge about the natural history of aICAS and facilitate studies of aICAS-associated disorders among rural-dwelling Chinese adults, such as ischaemic stroke and vascular cognitive impairment.

TRIAL REGISTRATION NUMBER

ChiCTR1800017197.

Symptomatic and asymptomatic intracranial atherosclerotic stenosis: 3 years' prospective study

BACKGROUND

Intracranial stenoses can cause TIA/ischaemic stroke. The purpose of this study was to assess vascular risk factors, clinical and imaging findings and outcome in Caucasians with intracranial stenosis under best prevention management.

METHODS

In this prospective observational study (from 05/2012, to last follow-up 06/2017) we compared vascular risk factors, imaging findings and long-term outcome in Swiss patients with symptomatic versus asymptomatic intracranial atherosclerotic stenoses on best prevention management.

RESULTS

62 patients were included [35.5% women, median age 68.3 years], 33 (53.2%) with symptomatic intracranial stenoses. Vascular risk factors (p = 0.635) and frequency of anterior circulation stenoses (66.7% vs. 55.2%; p = 0.354) did not differ between symptomatic and asymptomatic patients, but CT/MR-perfusion deficits in the territory of the stenosis (81.8% vs. 51.7%; p = 0.011) were more common in symptomatic patients. Outcome in symptomatic and asymptomatic patients at last follow-up was similar (mRS 0-1:66.7% vs. 75%;_adjp = 0.937, mRS _adjp-shift = 0.354, survival:100% vs. 96.4%;_adjp = 0.979). However, during 59,417 patient follow-up days, symptomatic patients experienced more cerebrovascular events (ischaemic stroke or TIA) [37.5% vs. 7.1%;_adjHR 7.58;_adjp = 0.012], mainly in the territory of the stenosis [31.3% vs. 3.6%;_adjHR 12.69;_adjp = 0.019], more vascular events (i.e. ischaemic stroke/TIA/TNA and acute coronary/peripheral vascular events) [62.5% vs. 14.3%;_adjHR 6.37;_adjp = 0.001]) and more multiple vascular events (p-trend = 0.006; ≥ 2:37.5% vs. 10.7%;_adj OR 5.37;_adjp = 0.022) than asymptomatic patients.

CONCLUSIONS

Despite best prevention management, one in three patients with a symptomatic intracranial stenosis suffered a cerebrovascular event, three in five a vascular event and two in five ≥ 2 vascular events. There is an unmet need for more rigorous and effective preventive strategies in patients with symptomatic intracranial stenoses.

A cross-sectional feasibility study of neurovascular ultrasound in Malawian adults with acute stroke-like syndrome

Background

In sub-Saharan Africa, there is a dearth of epidemiologic data on the burden of cerebral atherosclerosis. This is explained by the limited availability and the high cost of standard vascular imaging techniques. Neurovascular ultrasound is portable, cheaper and non-invasive and could, therefore, represent a reasonable alternative to fill this knowledge gap. We explored the feasibility of neurovascular ultrasound in Malawian adults with acute stroke-like syndrome to inform the design of future large stroke studies comparing its diagnostic performance to that of gold standard vascular imaging techniques in sub-Saharan Africa.

Methods

We enrolled consecutive patients diagnosed with acute stroke-like syndrome based on the World Health Organization definition. Clinical and demographic data were recorded, and a comprehensive neurovascular ultrasound was performed. Fisher’s exact and Kruskal-Wallis tests were used to study the relationship between atherosclerosis and potential risk factors.

Results

Sixty-six patients were enrolled (mean age: 58.7 years). The frequency of extracranial atherosclerosis was 39.4% (n = 26, 95% CI: 28.6–52.2). There were 12 patients with abnormal carotid intima media thickness (18.2%, 95% CI: 9.8–29.6) and 14 patients with a carotid plaque (21.2%, 95% CI: 12.1–33.0). The frequency of intracranial atherosclerosis was 19.2% (95%CI: 6.6–39.4) in 26 patients with successful transcranial insonation. Hypertension (80.8 versus 52.5%, p = 0.03) and hypercholesterolemia (11.5 versus 0.0%, p = 0.05) were more prevalent in patients with extracranial atherosclerosis.

Conclusions

This study demonstrates the feasibility of neurovascular ultrasound to assess cervical arteries in adults with stroke-like syndrome in sub-Saharan Africa. There is a high rate of transcranial insonation failure in this setting, highlighting the need for echocontrast agents.

Antithrombotic Management of Ischemic Stroke

PURPOSE OF REVIEW

Ischemic stroke describes a condition in which inadequate blood flow leads to lack of oxygenation to the brain tissue and ensuing neuronal death. There are multiple causes of ischemic stroke, each of which may indicate different antithrombotic management strategies. The goal of this review is to provide information about antithrombotic therapies for secondary stroke prevention based on etiology of stroke.

RECENT FINDINGS

New studies of existing antiplatelet and antithrombotic therapies have demonstrated varied efficacies of treatments based on the underlying risk factor of ischemic stroke. Understanding the optimal therapies for secondary stroke prevention can enhance care of stroke patients and lower the incidence of recurrent cerebrovascular ischemia.

Assessing the performance of monocyte to high-density lipoprotein ratio for predicting ischemic stroke: insights from a population-based Chinese cohort

Background

Monocyte to high-density lipoprotein cholesterol ratio (MHR) is a recently emerged measure of inflammation and oxidative stress and has been used to predict multiple cardiovascular abnormalities, but data relative to ischemic stroke are lacking. The goal of this study was to estimate the associations of MHR and prevalent ischemic stroke among a large cohort of general Chinese population.

Method

The study analyzed 8148 individuals (mean age: 54.1 years; 45.7% males) enrolled in a cross-sectional population-based Northeast China Rural Cardiovascular Health Study (NCRCHS). We identified 194 patients admitted from January and August 2013 with ischemic stroke.

Results

After adjustment for age, sex, and potential confounders, each standard deviation (SD) increment of MHR was predictive to a greater odd of ischemic stroke (odds ratio, 1.276; 95% confidence interval [CI], 1.082–1.504), with subjects in the highest quartile of MHR levels having a 1.6-fold higher risk of prevalent ischemic stroke (95% CI, 1.045–2.524) as compared with those in the lowest quartile. Moreover, smoothing curve showed a linear positive pattern of this association. The area under the curve (AUC) significantly increased (P = 0.042) to 0.808 (95% CI, 0.779–0.837) when the combined MHR was added to the baseline logistic regression model with ischemic stroke risk factors. Also, MHR (0.004) significantly improved integrated discrimination improvement when added to the baseline model.

Conclusions

The present study demonstrated for the first time a linear relation between MHR levels and the odds of ischemic stroke in a large community-based population. The MHR, a marker of high atherosclerotic burden, demonstrated incremental predictive value over traditional clinical risk factors, thus providing clinical utility in risk stratification in subjects presenting with ischemic stroke. These findings had implications for strategies aimed at lowering MHR to prevent adverse cardiovascular and cerebrovascular outcomes.

Cerebral Arterial Stiffness as A New Marker of Early Stage Atherosclerosis of The Cerebral Large Artery in Acute Stroke

Aim: Carotid–cer ebral pulse wave velocity (ccPWV) reflects the segment (C-M segment) stiffness between the common carotid artery and ipsilateral middle cerebral artery. C-M segment atherosclerosis (CMSA) is regarded the most frequent cause of anterior circulation ischemic stroke. We aimed to evaluate the association of ccPWV with early stage CMSA in this study.

Methods: Eighty-one acute ischemic stroke (AIS) patients with 154 C-M segments who were successfully evaluated with digital subtraction angiography, ccPWV, carotid intima–media thickness (cIMT), and brachial–ankle pulse wave velocity were enrolled into this study. Patient demographics and clinical data were retrieved from our AIS databases.

Results: Multivariate analyses showed that CMSA was independently associated with higher systolic BP, ccPWV, and cIMT. ccPWV and cIMT presented good diagnostic values for evaluating early stage CMSA in the receiver operating characteristic curve analyses. The areas under the curve (AUCs) of ccPWV were significantly higher than that of cIMT (Z = 2.204, P = 0.007). The AUC, sensitivity, specificity, Youden index, and cutoff of ccPWV for detecting early stage CMSA were 0.815 (P < 0.001), 86%, 70.7%, 0.567, and 5.4 m/s, respectively. Furthermore, ccPWV was significantly correlated with the stenosis of CMSA at the early stage in Spearman's correlation analyses (r = 0.877, P < 0.001) and fractional polynomial plot with 95% confidence intervals.

Conclusions: Cerebral arterial stiffness has the potential to be a new marker of early stage atherosclerosis of the cerebral large artery. This finding may help us prevent the occurrence of stroke and decrease the burden of society from stroke patients.

Association between Cerebral Arterial Stiffness and Large Artery Atherosclerosis in Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Carotid-cerebral pulse wave velocity (ccPWV) reflects the segment (C-M segment) stiffness between common carotid artery and ipsilateral middle cerebral artery. The C-M segment atherosclerosis (CMSA) is regarded as a most frequent cause of anterior circulation ischemic stroke. We therefore, attempted to investigate the relationship between cerebral arterial stiffness and CMSA, and provide reliable data for the early diagnosis of CMSA.

METHODS

Between June 2012 and August 2016, 81 acute ischemic stroke (AIS) patients with 154 C-M segments successfully evaluated with digital subtraction angiography and ccPWV were enrolled into this study. Patient demographics and clinical data were retrieved from our AIS databases.

RESULTS

Multivariate analyses showed that ccPWV was independently associated with CMSA (β = 39.6, P = .009) and Systolic blood pressure (β = 7.1, P < .001) in AIS patients. The values of ccPWV had a trend to be higher in the groups with more lesions (F = 45.9, P < .01) and severer stenosis (F = 102.6, P = .000), and was positively correlated with the number of lesions (r = .662, P = .000), and degree of stenosis (r = .858, P = .000) of CMSA. The fractional polynomial plots with 95% CIs also describe the close relationship between ccPWV and the number of lesions and degree of stenosis in CMSA.

CONCLUSIONS

Cerebral arterial stiffness is independently associated with the presence of CMSA, closely related to the vascular damage of C-M segment and reflects the vascular structure change of C-M segment in AIS patients. It may have the potential for assessment of CMSA in its initial stage.

Association between fasting Triglyceride levels and the Prevalence of Asymptomatic Intracranial Arterial Stenosis in a Chinese Community-based Study

The aim of this study was to assess the association between fasting triglyceride (FTG) levels and the prevalence of asymptomatic intracranial arterial stenosis (ICAS). The Asymptomatic Polyvascular Abnormalities Community (APAC) study is a sub-population of the Kailuan study which targeting on the epidemiology of asymptomatic polyvascular abnormalities in Chinese adults. A total number of 5345 participants, aged ≥40, and without history of stroke, transient ischemic attack, and coronary heart disease were enrolled in this study. Transcranial Doppler Ultrasonography was performed for the detection of ICAS presence. Out of 5345 participants, 698 subjects diagnosed ICAS (13.1%). In univariate analysis, the association between fasting TG (FTG) levels and asymptomatic ICAS didn't reach statistical significance (OR: 0.99, 95% CI: 0.89-1.09; P = 0.79), the same conclusion was reached in multivariate analysis, after adjustment for age, sex (OR: 1.05, 95% CI: 0.95-1.17) and age, sex, current smoking status, hypertension, diabetes, body mass index, estimated glomerular filtration rate, total cholesterol, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol (OR: 0.95, 95% CI: 0.84-1.06), respectively. FTG failed to show any statistical significance on ICAS presence in the APAC study, but the TG actually plays an important role in the progression of atherosclerosis as a biomarker.

Prevalence and risk factors of intracranial and extracranial artery stenosis in asymptomatic rural residents of 13 villages in China

Background

The present study aimed to investigate the prevalence and risk factors for extracranial carotid artery stenosis (ECAS) and intracranial carotid artery stenosis (ICAS) simultaneously in asymptomatic Chinese pure rural population.

Methods

We analyzed 2589 asymptomatic subjects aged over 30 yr. by ultrasonography and transcranial Doppler simultaneously in 13 isolated villages by door-to-door investigation. Both ECAS and ICAS were defined as more than 50% stenosis. Demographics, medical history documentation, and investigation of biochemical results were performed for each subject. Univariate and multivariate logistic regression analyses were employed to assess the risk factors associated with ECAS and ICAS, respectively.

Results

One hundred twenty-two (4.7%) residents with ICAS and 56 (2.2%) with ECAS were found in 2589 subjects. Three factors emerged as independent risk factors for ICAS: age (95% confidence interval [CI] = 1.01–1.04, odds ratio [OR] = 1.07), hypertension (95% CI = 1.98–4.37, OR = 2.94), and diabetes mellitus (95% CI = 1.72–4.38, OR = 2.75). As for ECAS, five factors presented as independent risk factors: age (95% CI = 1.09–1.11, OR = 1.10), male sex (95% CI = 1.01–1.02, OR = 1.01), diabetes mellitus (95% CI = 1.10–2.12, OR = 1.53), systolic blood pressure (95% CI = 1.95–2.88, OR = 2.37), and total cholesterol (95% CI = 1.00–1.13, OR = 1.06).

Conclusions

ICAS and ECAS were relatively common among asymptomatic rural Chinese subjects. Although they shared similar risk factors, differences still existed between them.

Decreased Estimated Glomerular Filtration Rate (eGFR), Not Proteinuria, Is Associated with Asymptomatic Intracranial Arterial Stenosis in Chinese General Population

The relationship between chronic kidney disease (CKD), which is defined by declined estimated glomerular filtration rate (eGFR) and/or proteinuria, and asymptomatic intracranial arterial stenosis (ICAS) is largely unknown. We conducted a population-based, cross-sectional study by recruiting 5209 participants free of previous stroke, transient ischemic attack and coronary heart disease. eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula and proteinuria was estimated with urine dipstick. The presence of ICAS was assessed by transcranial color-coded Doppler (TCD). Out of the whole population, 684 (13.1%) participants suffered ICAS. After adjusting for the confounding factors, eGFR < 45 ml/min/m² was an independent risk factor of asymptomatic ICAS (odds ratio [OR], 3.29, 95% confidence interval [CI], 1.67–6.51), but the trend was different between the two groups stratified by the age of 60 (P = 0.01). However, the association between proteinuria and asymptomatic ICAS was not statistically significant. In conclusion, declined eGFR, not proteinuria, is associated with asymptomatic ICAS in Chinese general population, especially in people over 60 years old.

Thrombin generation and intracranial atherosclerotic disease in patients with a transient ischaemic attack

BACKGROUND

Intracranial atherosclerotic disease (ICAD) is responsible for at least 10% of transient ischaemic attacks (TIA). Thrombin generation has been shown to be associated with several atherosclerotic conditions and may be relevant in the pathogenesis of TIA from ICAD.

OBJECTIVE

To evaluate the association between thrombin generation and ICAD in patients with TIA.

MATERIALS AND METHODS

Consecutive patients with confirmed diagnosis of TIA by vascular neurologist were enrolled. Within 24h from diagnosis, all the patients underwent: blood samples including thrombin generation search, electrocardiography, brain CT scan, blood pressure (BP) measurement, supra-aortic echo-Doppler, transcranial Doppler (TCD) and standard echocardiogram. Thrombin generation was measured as endogenous thrombin potential (ETP) in platelet-rich plasma (PRP) and in platelet-poor plasma (PPP), in the presence and in the absence of thrombomodulin (TM).

RESULTS

120 patients (male 52.5%), aged 69±16years were enrolled. Ten patients on warfarin treatment had significantly lower ETP than the others. Among the remaining, ETP in the presence or absence of TM did not differ according to TOAST classification aetiology (large vessel vs. cardioembolic vs. lacunar vs. others). In PRP, ETP was similar in patients with ICAD and in those without (1748±160 vs. 1851±36nM·min, p=0.393), whereas, ETP measured in presence of thrombomodulin was higher in patients with than in those without ICAD (2045±99 vs. 1715±41nM·min, p=0.011). In PPP, ETP was similar in patients with ICAD and in those without, whereas thrombin peak was higher in patients with ICAD than in those without both in the presence (165±17 vs. 130±5nM, p=0.036) and in the absence of TM (178±19 vs. 142±5nM, p=0.037).

CONCLUSION

ETP measured in presence of TM is enhanced in patients with ICAD, supporting that thrombomodulin-protein C pathways is relevant in TIA from ICAD. These hypothesis-generating data suggest that thrombin generation may be relevant in cerebral ischaemia from intracranial disease, and justify larger studies.

Impact of MCA stenosis on the early outcome in acute ischemic stroke patients

Background

Asians have higher frequency of intracranial arterial stenosis. The present study aimed to compare the clinical features and outcomes of ischemic stroke patients with and without middle cerebral artery (MCA) stenosis, assessed by transcranial sonography (TCS), based on the Taiwan Stroke Registry (TSR).

Methods

Patients with acute ischemic stroke or transient ischemic attack registered in the TSR, and received both carotid duplex and TCS assessment were categorized into those with stenosis (≥50%) and without (<50%) in the extracranial internal carotid artery (ICA) and MCA, respectively. Logistic regression analysis, Kaplan-Meier method and Cox proportional hazard model were applied to assess relevant variables between groups.

Results

Of 6003 patients, 23.3% had MCA stenosis, 10.1% ICA stenosis, and 3.9% both MCA and ICA stenosis. Patients with MCA stenosis had greater initial NIHSS, higher likelihood of stroke-in-evolution, and more severe disability than those without (all p<0.001). Patients with MCA stenosis had higher prevalence of hypertension, diabetes and hypercholesterolemia. Patients with combined MCA and extracranial ICA stenosis had even higher NIHSS, worse functional outcome, higher risk of stroke recurrence or death (hazard ratio, 2.204; 95% confidence intervals, 1.440–3.374; p<0.001) at 3 months after stroke than those without MCA stenosis.

Conclusions

In conclusion, MCA stenosis was more prevalent than extracranial ICA stenosis in ischemic stroke patients in Taiwan. Patients with MCA stenosis, especially combined extracranial ICA stenosis, had more severe neurological deficit and worse outcome.

Decreased muscle mass in Korean subjects with intracranial arterial stenosis: The Kangbuk Samsung Health Study

BACKGROUNDS AND AIMS

Intracranial arterial stenosis (ICAS) is a common cause of ischemic stroke in Asians. Decreased muscle mass is one of the major causes of chronic disease in adults. The purpose of this study was to analyze the relationship between muscle mass and ICAS in Korean adults.

METHODS

For this study, we selected a total of 10,530 participants (mean age, 43.3 years; 8558 men) in a health screening program, for whom transcranial Doppler (TCD) ultrasound was used to detect >50% ICAS based on criteria modified from the stroke outcomes and neuroimaging of intracranial atherosclerosis trial. Body composition was evaluated by bioelectrical impedance analysis (BIA). Skeletal muscle index (SMI) was calculated with muscle mass/weight (kg) * 100.

RESULTS

Among the total patient population, 322 (3.1%) subjects had ICAS. Subjects with ICAS were older, and had higher mean values for fasting glucose, body mass index and blood pressure compared with those without ICAS. Subjects with ICAS had significantly lower muscle mass, SMI and higher percent body fat compared with those without ICAS. In logistic regression analysis, the subjects in the highest tertile of muscle mass had the lowest odds ratio for ICAS with the lowest tertile group of muscle mass as the reference group even after adjusting for age, systolic blood pressure, fasting blood glucose, sex, smoking and exercise (OR 0.650, 95% CI 0.442-0.955).

CONCLUSIONS

Subjects with ICAS had significantly decreased muscle mass compared with those without ICAS in Korean adults. The risk for ICAS was lower in subjects with higher muscle mass.

Stroke due to large vessel atherosclerosis: Five new things

Purpose of review

Extracranial (EC) and intracranial (IC) large vessel atherosclerosis account for about 20% of ischemic stroke cases. In recent years, new treatments have emerged for treatment of both EC and IC disease.

Recent findings

The stroke rate in patients with carotid stenosis is decreasing with modern medical therapy. For patients with asymptomatic stenosis, the stroke rate is likely <1% per year. Some subsets of patients with symptomatic carotid disease benefit less from revascularization, and medical management can be considered in these patients. A second clinical trial has confirmed that aggressive medical management is the treatment of choice for IC atherosclerotic disease. Vessel wall imaging may be useful to define pathophysiology in patients with IC stenosis and could ultimately help tailor therapy, but further studies are needed. Medical therapy is preferred to stenting for patients with vertebral artery-origin stenosis.

Summary

Recent data and emerging concepts regarding large vessel atherosclerosis are provided.

A Prospective Study of Asymptomatic Intracranial Atherosclerotic Stenosis in Neurologically Normal Volunteers in a Japanese Cohort

Atherosclerotic stenosis of major intracranial arteries is a leading cause of ischemic stroke in Asia. However, the long-term prognosis of asymptomatic intracranial atherosclerotic stenosis (ICAS) in healthy volunteers has not been fully examined. Here, we conducted a longitudinal study to examine the prognosis of healthy volunteers with asymptomatic ICAS and to determine the risk factors for ICAS, including asymptomatic brain parenchymal lesions. We studied 2,807 healthy Japanese volunteers with no history of stroke (mean age, 62.0 years). They were followed for a mean interval of 64.5 months. The degree of ICAS and the presence of asymptomatic brain lesions were assessed by using magnetic resonance imaging. Asymptomatic ICAS was detected in 166 volunteers (5.9%) at the initial examination. Moderate and mild stenoses were observed in 1.5 and 4.4% of patients, respectively. Significant risk factors for ICAS were older age and a history of hypertension and/or dyslipidemia. During follow-up, ischemic stroke developed in 32 volunteers. Seven strokes occurred in the ICAS group, whose stroke incidence rate was higher than that in the non-ICAS group (0.78 vs. 0.18% per year). According to a Cox regression analysis, asymptomatic ICAS was an independent risk factor for future ischemic stroke after adjustment for age. Furthermore, after asymptomatic brain lesions were taken into account, ICAS was still a significant risk factor for stroke onset. In conclusion, even mild to moderate asymptomatic ICAS was a significant risk factor for future stroke, independent of asymptomatic brain lesions, in a healthy Japanese population. Mild to moderate ICAS might be a therapeutic target for stroke prevention.

Predictors of intracranial cerebral artery stenosis in patients before cardiac surgery and its impact on perioperative and long-term stroke risk

BACKGROUND

The aim of this prospective study was to determine the prevalence of stenosis within intracranial and extracranial arteries in patients before coronary artery bypass surgery (CABG), to evaluate the influence of intracranial artery stenosis on neurological outcome and to identify preoperative risk factors for these patients.

METHODS

One hundred and seventy-five patients (71% males, mean age=66.1) scheduled for CABG were enrolled for extracranial Doppler duplex sonography, transcranial color-coded duplex sonography (TCCS) and transcranial Doppler (TCD) examination.

RESULTS

Twenty-six patients (14.7%) had extracranial stenosis or occlusion and 13 patients (7.3%) intracranial vascular disease. Six patients (3.5%) had both extra- and intracranial artery disease. The presence of peripheral artery disease and diabetes mellitus was a strong risk factor for extracranial artery stenosis but not for intracranial artery stenosis, which occurred independently also of typical atherosclerotic risk factors like age >70, male sex, hypertension, hyperlipidemia, hyperhomocysteinemia, smoking habit, obesity (BMI>30) and waist to hip ratio >1. Functional neurological outcome of the patients with intracranial arterial disease evaluated 7 days after CABG was the same as the patients without extra- and intracranial stenosis. However, 12-months neurological follow-up revealed significantly more ischemic strokes in patients with intracranial artery stenosis compared to patients without intracranial stenosis (p=0.015).

CONCLUSION

The occurrence of intracranial artery stenosis in CABG patients cannot be predicted by well-known atherosclerotic risk factors and seems not to be associated with perioperative stroke.

Intracranial arterial stenosis in Ecuadorian Natives/Mestizos. A population-based study in older adults (The Atahualpa Project)

BACKGROUND

Intracranial arterial stenosis (IAS) is more prevalent among Asians, Blacks and Caribbean Hispanics than in Whites. However, there is no information on the importance of this common cause of stroke among Mestizo/Native populations of Latin America. We aimed to assess prevalence and correlates of IAS in an indigenous Ecuadorian population of older adults.

METHODS

Atahualpa residents aged ≥60 years were identified during door-to-door surveys and invited to undergo brain magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of intracranial vessels for identification of stroke lesions and arterial stenosis. Prevalence of IAS was assessed in patients with strokes as well as in stroke-free individuals. A logistic regression model was constructed with stroke as the outcome, IAS as the exposure, and confounders (demographics and cardiovascular risk factors) as independent variables.

RESULTS

Out of 267 participants (mean age 71 ± 8 years, 57% women), 15 (5.6%) had intracranial arterial stenosis, including 10 out of 52 (19.2%) persons with stroke and five out of 215 (2.3%) without. The multivariate logistic regression model showed significant association of IAS with stroke after adjusting for demographics and cardiovascular risk factors (OR: 7.9, 95% C.I.: 2.2-27.8, p=0.001). Mechanisms underlying stroke in patients with IAS included perforator occlusion, artery-to-artery embolism and hypoperfusion.

CONCLUSIONS

Prevalence of IAS in Ecuadorian Natives/Mestizos is similar to that in Asians. Individuals aged ≥60 years with IAS are almost eight times more likely to have a stroke after adjusting for confounding variables.

Increased risk for intracranial arterial stenosis in subjects with coronary artery calcification

BACKGROUND AND PURPOSE

Intracranial arterial stenosis (ICAS) is considered an important cause of stroke in Asians. Coronary artery calcification (CAC) is a surrogate marker for subclinical atherosclerosis. We aimed to analyze the association of ICAS assessed by transcranial Doppler ultrasonography and CAC in middle-aged Korean population.

METHODS

This study included 10 550 participants (81.3% men, mean age 43 years) from a health screening program, in whom transcranial Doppler ultrasonography was used to detect >50% intracranial stenosis based on criteria modified from the stroke outcomes and neuroimaging of intracranial atherosclerosis trial. Multidetector computed tomography was used to assess coronary artery calcium score (CACS). CAC grade (0, 1-100, and >100) was defined by CACS.

RESULTS

The subjects with CAC showed significantly higher proportion of subjects with ICAS compared with those without CAC (4.4% versus 2.8%; P<0.01). Conversely, the subjects with ICAS showed significantly higher proportion of subjects with CAC (24.8% versus 17.1%; P<0.01). When logistic regression analysis was performed with ICAS as the dependent variable, the presence of CAC showed significantly increased risk for ICAS after adjustment for confounding variables (odds ratio, 1.439; 95% confidence interval, 1.095-1.891). When CACS grade was included in the model, the odds ratio for ICAS was the highest in subjects with CACS >400 compared with those with CACS=0 (odds ratio, 2.754; 95% confidence interval, 1.205-2.936).

CONCLUSIONS

The risk for ICAS was significantly increased in middle-aged Korean subjects with CAC compared with that in those without CAC. These findings suggest the possibility of a separate undetected atherosclerotic focus in subjects with 1 atherosclerotic event.