Prevalence of Systemic Atherosclerosis Burdens and Overlapping Stroke Etiologies and Their Associations With Long-term Vascular Prognosis in Stroke With Intracranial Atherosclerotic Disease

Concurrent intracranial and extracranial artery stenosis and the prognosis of transient ischaemic symptoms or imaging-negative ischaemic stroke

BACKGROUND AND PURPOSE

Transient ischaemic attack (TIA), transient symptoms with infarction (TSI) and diffusion-weighted imaging (DWI)-negative acute ischaemic stroke (AIS) share similar aetiologies but are considered to have a rather benign prognosis. We intended to investigate the association between intracranial atherosclerotic stenosis (ICAS), extracranial atherosclerotic stenosis (ECAS) and the prognosis of patients with TIA, TSI and DWI-negative AIS.

METHODS

Clinical and imaging data of eligible participants were derived from the Chinese Intracranial Atherosclerosis study, according to symptom duration, acute infarction on DWI and discharge diagnosis. Based on the severity and location of arterial atherosclerosis, we categorised the study population into four groups: no or <50% ICAS and no ECAS; ≥50% ICAS but no ECAS; no or <50% ICAS with ECAS; and concurrent ≥50% ICAS and ECAS. Using multivariable Cox regression models, we analysed the relationship between the severity and distribution of large artery atherosclerosis and the prognosis of TIA, TSI and DWI-negative AIS.

RESULTS

A total of 806 patients were included, 67.3% of whom were male. The median age of the study participants was 63 years. Patients in the concurrent ≥50% ICAS and ECAS subgroup had both a significantly higher 1-year recurrence rate (adjusted HR 3.4 (95% CI 1.15 to 10.04), p=0.027) and a higher risk of composite vascular events (adjusted HR 3.82 (95% CI 1.50 to 9.72), p=0.005).

CONCLUSIONS

Concurrent ICAS and ECAS is associated with a higher possibility of 1-year recurrent stroke or composite vascular events. Large artery evaluation is necessary to assess patients with transient ischaemic symptoms or DWI-negative AIS. Progress in shortening the time interval between symptom onset and large vessel evaluation is needed.

Prognosis of Asymptomatic Intracranial Stenosis in Patients With Transient Ischemic Attack and Minor Stroke

Importance

Asymptomatic intracranial stenosis (ICS) is a frequent finding on imaging results, particularly in the assessment of acute stroke. Although the management of symptomatic ICS is informed by randomized trials, to our knowledge there are few data on the prevalence and prognosis of asymptomatic ICS in patients with stroke and transient ischemic attack (TIA).

Objective

To study the age-specific prevalence and prognosis of asymptomatic ICS in a population-based cohort of patients with TIA and minor stroke.

Design, Setting, and Participants

All patients (predominantly white) recruited to the Oxford Vascular Study (Oxfordshire, England) between March 1, 2011, and March 1, 2018, with TIA and minor ischemic stroke (National Institutes of Health Stroke Scale score, ≤3), irrespective of age, were included (n = 1579). We determined the age-specific prevalence of 50% or more asymptomatic ICS and the associated stroke risk by face-to-face follow-up to 2018 on standard medical treatment without stenting.

Exposures

Patients underwent magnetic resonance angiography of the intracranial and cervicocranial arteries, computed tomography angiography if magnetic resonance angiography was contraindicated, or carotid/transcranial Doppler ultrasonography if computed tomography angiography was contraindicated.

Main Outcomes and Measures

The primary outcomes were the prevalence and prognosis of asymptomatic ICS.

Results

Of 1368 eligible patients (mean [SD] age, 69.2 [13.9] years; 700 men [51.2%]) with intracranial vascular imaging, 426 ICS were identified in 260 patients (19.0%): 58 (4.2%) with only symptomatic ICS, 155 (11.3%) with only asymptomatic ICS, and 47 (3.4%) with both. The prevalence of any asymptomatic ICS increased from 4.8% for patients younger than 70 years to 34.6% for patients 90 years or older (P for trend < .001; odds ratio per decade, 1.96; 95% CI, 1.69-2.27) and was greater than that of 50% or more asymptomatic carotid bifurcation stenosis (202 [14.8%] vs 105 patients [7.2%]; relative risk, 2.04; 95% CI, 1.63-2.55, P < .001). However, the 155 patients with only asymptomatic ICS had no increase in risk of ischemic stroke compared with those with no ICS (unadjusted HR, 1.03, 95% CI, 0.49-2.17), with 8 first recurrent events (5.2%) during 506 patient-years of follow-up and 3 in the territory of the ICS (annualized risk, 0.59%; 95% CI, 0.12-1.73).

Conclusions and Relevance

The prevalence of asymptomatic ICS increases with age in white patients with TIA and minor stroke and is greater than that of asymptomatic carotid stenosis, but asymptomatic ICS does not increase the short- or medium-term risk of distal recurrent ischemic stroke for patients receiving standard medical treatment.

Genetic Risk Factors of Intracranial Atherosclerosis

PURPOSE OF REVIEW

Intracranial atherosclerosis (ICAS) is the most common cause of stroke throughout the world. It also increases the risk of recurrent stroke and dementia. As a complex and multifactorial disease, ICAS is influenced by multiple genetic, biological, and environmental factors. This review summarizes the candidate gene and genome-wide studies aimed at discovering genetic risk factors of ICAS.

RECENT FINDINGS

Numerous studies have focused on the association between single-nucleotide polymorphisms (SNPs) of atherosclerosis-related genes and the risk of ICAS. Variants in adiponectin Q (ADIPOQ), ring finger protein 213 (RNF213), apolipoprotein E (APOE), phosphodiesterase 4D (PDE4D), methylenetetrahydrofolate reductase (MTHFR), lipoprotein lipase (LPL), α-adducin (ADD1) genes, angiotensin-converting enzyme (ACE), and other genes related to renin-angiotensin-aldosterone system have been associated with ICAS. We review the available evidences on the candidate genes and SNPs associated with genetic susceptibility to ICAS, and point out future developments of this field. Genetic discoveries could have clinical implications for intracranial atherosclerotic disease.

Validation of Risk Prediction Models to Detect Asymptomatic Carotid Stenosis

Background Significant asymptomatic carotid stenosis (ACS) is associated with higher risk of strokes. While the prevalence of moderate and severe ACS is low in the general population, prediction models may allow identification of individuals at increased risk, thereby enabling targeted screening. We identified established prediction models for ACS and externally validated them in a large screening population. Methods and Results Prediction models for prevalent cases with ≥50% ACS were identified in a systematic review (975 studies reviewed and 6 prediction models identified [3 for moderate and 3 for severe ACS]) and then validated using data from 596 469 individuals who attended commercial vascular screening clinics in the United States and United Kingdom. We assessed discrimination and calibration. In the validation cohort, 11 178 (1.87%) participants had ≥50% ACS and 2033 (0.34%) had ≥70% ACS. The best model included age, sex, smoking, hypertension, hypercholesterolemia, diabetes mellitus, vascular and cerebrovascular disease, measured blood pressure, and blood lipids. The area under the receiver operating characteristic curve for this model was 0.75 (95% CI, 0.74-0.75) for ≥50% ACS and 0.78 (95% CI, 0.77-0.79) for ≥70% ACS. The prevalence of ≥50% ACS in the highest decile of risk was 6.51%, and 1.42% for ≥70% ACS. Targeted screening of the 10% highest risk identified 35% of cases with ≥50% ACS and 42% of cases with ≥70% ACS. Conclusions Individuals at high risk of significant ACS can be selected reliably using a prediction model. The best-performing prediction models identified over one third of all cases by targeted screening of individuals in the highest decile of risk only.

Predicting Stroke Outcomes Using Ankle-Brachial Index and Inter-Ankle Blood Pressure Difference

Background: This study investigated the association of high ankle-brachial index difference (ABID) and systolic inter-ankle blood pressure difference (IAND) with short- and long-term outcomes in acute ischemic stroke patients without peripheral artery disease (PAD). Methods: Consecutive patients with acute ischemic stroke who underwent ankle-brachial index (ABI) measurement were enrolled. ABID was calculated as |right ABI-left ABI|. IAND and systolic inter-arm blood pressure difference (IAD) were calculated as |right systolic blood pressure – left systolic blood pressure|. Poor functional outcome was defined as modified Rankin Scale score ≥3 at 3 months. Major adverse cardiovascular events (MACEs) were defined as stroke recurrence, myocardial infarction, or death. Results: A total of 2901 patients were enrolled and followed up for a median of 3.1 (interquartile range, 1.6–4.7) years. Among them, 2643 (84.9%) patients did not have PAD. In the logistic regression analysis, ABID ≥ 0.15 and IAND ≥ 15 mmHg were independently associated with poor functional outcome (odds ratio (OR), 1.970, 95% confidence interval (CI), 1.175‒3.302; OR, 1.665, 95% CI, 1.188‒2.334, respectively). In Cox regression analysis, ABID ≥0.15 and IAND ≥ 15 mmHg were independently associated with MACEs (hazard ratio (HR), 1.514, 95% CI, 1.058‒2.166; HR, 1.343, 95% CI, 1.051‒1.716, respectively) and all-cause mortality (HR, 1.524, 95% CI, 1.039‒2.235; HR, 1.516, 95% CI, 1.164‒1.973, respectively) in patients without PAD. Conclusion: High ABID and IAND are associated with poor short-term outcomes, long-term MACE occurrence, and all-cause mortality in acute ischemic stroke without PAD.

Carotid Intima-Media Thickness and the Risk of First Stroke in Patients With Hypertension

Background and Purpose—

This study aimed to investigate the association between mean carotid intima-media thickness (cIMT) and the risk of first stroke and examine any possible effect modifiers in patients with hypertension.

Methods—

A total of 11 547 hypertensive participants without history of stroke from the CSPPT (China Stroke Primary Prevention Trial) were included in this analysis. The primary outcome was first stroke.

Results—

Over a median follow-up of 4.4 years, 726 first strokes were identified, of which 631 were ischemic, and 90 were hemorrhagic. A per SD increase in mean cIMT was positively associated with the risk of first stroke (hazard ratio [HR], 1.11 [95% CI, 1.03–1.20]), and first ischemic stroke (HR, 1.10 [95% CI, 1.01–1.20]). Moreover, when cIMT was categorized in quartiles, the higher risks of first stroke (HR, 1.31 [95% CI, 1.06–1.61]) and first hemorrhagic stroke (HR, 2.25 [95% CI, 1.11–4.58]) were found in participants in quartile 2 to 4 (≥0.66 mm), compared with those in quartile 1 (<0.66 mm). More importantly, the cIMT-first stroke association was significantly stronger in participants with higher mean arterial pressure (≥109.3 [quintile 5] versus <109.3 mm Hg, P -interaction=0.024) or diastolic blood pressure levels (≥90.7 [quintile 5] versus <90.7 mm Hg, P -interaction=0.009).

Conclusions—

There was a significant positive association between baseline cIMT and the risk of first stroke in patients with hypertension. This association was even stronger among those with higher mean arterial pressure or diastolic blood pressure levels.

Geometry of the Carotid Artery and Its Association With Pathologic Changes in a Chinese Population

Objectives

Carotid artery geometry influences blood flow disturbances and is thus an important risk factor for carotid atherosclerosis. Extracellular matrix (ECM) and yes-associated protein (YAP) expression may play essential roles in the pathophysiology of carotid artery stenosis, but the effect of blood flow disturbances of carotid bifurcation location on the ECM is unknown. We hypothesized that carotid artery anatomy and geometry are independently associated with the ECM and YAP expression.

Methods

In this cross-sectional study, 193 patients were divided into two groups: an asymptomatic group (n = 111) and a symptomatic group (n = 82), symptomatic patients presenting with ischemic attack, amaurosis fugax, or minor non-disabling stroke. For all subjects before surgery, carotid bifurcation angle and internal artery angle were measured with computed tomography angiography (CTA), and laminar shear stress was measured with ultrasonography. After surgery, pathology of all plaque specimens was analyzed using hematoxylin and eosin (HE) staining and Movat special staining. Immunohistochemistry was performed to detect expression of YAP in a subset of 30 specimens.

Results

Symptomatic patients had increased carotid bifurcation angle and laminar shear stress compared to asymptomatic patients (P < 0.05), although asymptomatic patients had increased internal carotid angle compared to symptomatic patients (P < 0.001). Relative higher bifurcation angles were correlated with increased carotid bifurcation, decreased internal angle, and decreased laminar shear stress. For each change in intervertebral space or one-third of vertebral body height, carotid bifurcation angle changed 4.76°, internal carotid angle changed 6.91°, and laminar shear stress changed 0.57 dynes/cm². Pathology showed that average fibrous cap thickness and average narrowest fibrous cap thickness were greater in asymptomatic patients than symptomatic patients (P < 0.05). Expression of proteoglycan and YAP protein in symptomatic patients was higher than in asymptomatic patients (P < 0.001), while collagen expression was lower in symptomatic patients than asymptomatic patients (P < 0.05).

Conclusion

Geometry of the carotid artery and position relative to cervical spine might be associated with ECM and YAP protein expression, which could contribute to carotid artery stenosis.

Co-existing cerebrovascular atherosclerosis predicts subsequent vascular event: a multi-contrast cardiovascular magnetic resonance imaging study

BACKGROUND

It is still unknown that whether co-existing intracranial stenosis and extracranial carotid vulnerable plaques have higher predictive value for subsequent vascular events. This study aimed to determine the relationship between co-existing extracranial carotid vulnerable plaques and intracranial stenosis and subsequent vascular events utilizing cardiovascular magnetic resonance (CMR) vessel wall imaging.

METHODS

Patients who had recent cerebrovascular symptoms in anterior circulation (< 2 weeks) were consecutively enrolled and underwent multi-contrast CMR vessel wall imaging for extracranial carotid arteries and 3D time-of flight CMR angiography for intracranial arteries at baseline. After baseline examination, all patients were followed-up for at least 1 year to determined recurrence of vascular events. The co-existing cerebrovascular atherosclerosis was defined as presence of both intracranial artery stenosis and at least one the following measures of extracranial artery atherosclerosis: plaque, calcification, lipid-rich necrotic core (LRNC), or intraplaque hemorrhage. Univariate and multivariate Cox regressions were used to calculate the hazard ratio (HR) and corresponding 95% confidence interval (CI) of co-existing plaques in predicting subsequent vascular events.

RESULTS

In total, 150 patients (mean age: 61.8 ± 11.9 years; 109 males) were recruited. During the median follow-up time of 12.1 months, 41 (27.3%) patients experienced vascular events. Co-existing intracranial artery stenosis and extracranial carotid plaque (HR, 3.57; 95% CI, 1.63-7.82; P = 0.001) and co-existing intracranial artery stenosis and extracranial carotid LRNC (HR, 4.47; 95% CI, 2.15-9.27; P < 0.001) were significantly associated with subsequent vascular events, respectively. After adjusted for confounding factors and carotid stenosis, these associations remained statistically significant (HR, 5.12; 95% CI, 1.36-19.24; P = 0.016 and HR, 8.12; 95% CI, 2.41-27.31; P = 0.001, respectively).

CONCLUSIONS

The co-existing cerebrovascular atherosclerotic diseases, particularly co-existing carotid lipid-rich necrotic core and intracranial stenosis, are independent predictors for subsequent vascular events.

The ASCOD Phenotyping of Embolic Strokes of Undetermined Source

BACKGROUND AND PURPOSE

Various pathogenesis are presumed to be involved in the etiology of embolic stroke of undetermined source (ESUS), which has a high recurrence rate, and much remains unknown about the clinical subtype of recurrent stroke. The purpose of this study was to clarify the pathogenesis of ESUS using the ASCOD classification for ESUS patients and to examine the factors involved in the recurrence of ischemic stroke.

METHODS

The subjects of this study were 236 of these patients who fulfilled the criteria for ESUS. The rate of stroke recurrent, subtype of recurrent ischemic stroke, and new-onset atrial fibrillation (AF) in these patients were surveyed retrospectively, and each patient was graded for the A, S, and C categories of the ASCOD classification.

RESULTS

Ischemic stroke recurred in 32 patients during the follow-up period (7 days to 12.9 years [median 54.3 months]), and new-onset AF was seen in 44 (18.6%) patients. The most subtype of recurrent ischemic stroke was ESUS again (19 patients). Multivariate analysis with a Cox proportional hazards model, the S score (hazard ratio 5.21; 95% confidence interval (CI) 2.38-11.42; P < .001) and the number of A, S, C categories (hazard ratio 1.90; 95% CI 1.14-3.10; P = .013) were factors significantly related to recurrent ischemic stroke.

CONCLUSIONS

Assessment of comorbid conditions in ESUS patients based on the ASCOD classification may be useful in predicting the likelihood of recurrence of ischemic stroke.

Coronary Artery Disease in Patients with Ischemic Stroke and TIA

BACKGROUND AND OBJECTIVES

Ischemic stroke (IS) and coronary artery disease (CAD) share common risk factors and one may be the harbinger of the other. We aimed to study prevalence of symptomatic and asymptomatic CAD in a cohort of consecutive patients with IS and assess its relationship with intracranial and extracranial large artery cerebrovascular disease (LAD).

METHODS

All consecutive eligible IS and Transient Ischemic Attack (TIA) patients were recruited into the study. Both clinically suspected and asymptomatic patients (N = 259) underwent myocardial Stress-rest Gated Technetium-99m (Tc99m) MIBI Myocardial Perfusion SPECT scan performed on a dual head SPECT-CT to estimate evidence of myocardial ischemia.

RESULTS

Three hundred patients completed the study. Forty one patients were previously diagnosed cases of definitive CAD. Twelve patients were clinically suspected to have CAD and 247 patients were asymptomatic. Among these, 12 patients (4.81%) had a positive SPECT. The overall prevalence of CAD was 17.67% (n = 53). Presence of diabetes was an independent predictor of CAD (OR 1.98, 95% CI 1.07-3.67. P .02). No significant association was found between the presence of LAD and CAD in all subgroup comparisons. However, there was a suggestion of higher LAD among patients with known CAD compared with others.

CONCLUSIONS

CAD is prevalent in patients with ischemic stroke. No definitive relationship was found between CAD and intracranial or extracranial LAD. Population based stratification tools are needed to further assess the need to detect subclinical CAD in patients with stroke.

The Clinical Importance of the Plasma Atherogenic Index, Other Lipid Indexes, and Urinary Sodium and Potassium Excretion in Patients with Stroke

Objective

Cardiovascular complications are still the primary reason for high mortality rates worldwide. The determination of risk factors is important to prevent stroke. The aim of the present study was to analyze the importance of serum lipid indexes and urinary sodium (Na)/potassium (K) excretion in patients with stroke together with sex differences.

Materials and Methods

A total of 50 (28 male and 22 female, mean age 65.9±14.6 years) patients with acute stroke were included in the study group, and 32 body mass index-matched healthy subjects were included in the control group. Lipid profiles [(cholesterol, triglyceride, very low-density lipoprotein, low-density lipoprotein, and high-density lipoprotein (HDL)], serum creatinine (Cre), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and Na, K, and Cre excretion in spot urine samples of the patients were recorded.

Results

Systolic blood pressure (p=0.021), ESR (p=0.044), and CRP (p=0.042) were significantly higher in all patients in the stroke group; urinary Tanaka (K) (p=0.033), Kawazaki (K) (p=0.028), urinary spot Cre (p=0.012), and Na excretion (p=0.036) levels were found to be significantly lower in only male patients with stroke. The mean plasma atherogenic indexes were 0.57±0.24 in the study (stroke) group and 0.54±0.22 in the control group (p=0.61). Other lipid indexes, such as Castelli's risk index (CRI)-I (p=0.29), CRI-II (p=0.24), atherogenic coefficient (p=0.29), and non-HDL cholesterol (p=0.69), were not statistically different from the controls.

Conclusion

Urinary Na, K, and Cre excretion was significantly lower in male patients with stroke, and acute phase reactants were significantly higher in the entire stroke group than in controls. These parameters can be used as auxiliary biomarkers in the risk assessment of stroke.

Patients with Acute Ischemic Cerebrovascular Disease with Coronary Artery Stenosis Have More Diffused Cervicocephalic Atherosclerosis

Aims: Coronary artery stenosis (CAS) ≥ 50% frequently coexists in patients with acute ischemic cerebrovascular disease (AICVD), which portends unfavorable outcomes. We sought to examine whether patients with AICVD with CAS had more severe and more diffused cervicocephalic atherosclerosis (CA).

Methods: Patients with AICVD were consecutively enrolled and underwent simultaneous computed tomography angiography (CTA) of the coronary and cervicocephalic arteries. A total of 140 patients were divided into “AICVD + CAS” and “AICVD only” groups according to whether CTA showed stenosis of ≥ 50% in at least one coronary arterial segment. The relationship of the presence of CAS with the severity and extent of CA were examined.

Results: The CA severity characteristics, including the presence of stenosis ≥ 50% and the grade of the most severe stenotic segment, were not significantly different between the two groups. Regarding the extent of CA, the presence of stenosis ≥ 50% in both sides (adjusted odds ratio [OR]: 4.29, 95% confidence interval [CI]: 1.67–10.98), both extracranial and intracranial (adjusted OR: 5.26, 95% CI: 2.24–12.35), both anterior and posterior circulation (adjusted OR: 5.29, 95% CI: 2.22–12.64), and the number of stenotic segments ≥ 50% in cervicocephalic arteries (adjusted OR: 1.58, 95% CI: 1.28–1.96) were associated with CAS in patients with AICVD, independently of clinical demographics and CA severity characteristics.

Conclusion: CA was similarly severe in patients with AICVD with and without CAS, but those with CAS had significantly more diffused CA. The extent of CA and CAS were mutual indicators in patients with AICVD, irrespective of CA severity.

The Barcelona-Asymptomatic Intracranial Atherosclerosis study: Subclinical intracranial atherosclerosis as predictor of long-term vascular events

BACKGROUND AND AIMS

Symptomatic intracranial atherosclerosis (ICAS) is associated with a high risk of stroke recurrence and occurrence of other vascular events. However, ICAS has been poorly studied from its asymptomatic stage. The objective of our study was to determine if subclinical intracranial atherosclerosis is associated with long-term incident vascular events in Caucasians.

METHODS

The Barcelona-Asymptomatic Intracranial Atherosclerosis (AsIA) Study is a population-based study that enrolled 933 subjects with a moderate-high vascular risk and without history of stroke or coronary disease, and determined the prevalence of asymptomatic ICAS and associated risk factors. At baseline visit, carotid atherosclerosis and ICAS were screened by color-coded duplex ultrasound, and moderate-severe stenosis was confirmed by magnetic resonance angiography. At baseline, 8.9% of subjects had asymptomatic ICAS, of whom 3.3% were moderate-severe. In the longitudinal phase, subjects were prospectively followed-up to assess the incidence of a combined primary endpoint of vascular events (stroke, acute coronary syndrome and/or vascular death).

RESULTS

After 7.17 years of follow-up, there were 51 incident cerebrovascular events (16 transient ischemic attacks, 27 ischemic, 8 hemorrhagic strokes), 63 incident coronary events and 23 vascular deaths. After multivariate Cox regression analyses adjusted by age, sex, vascular risk and presence of carotid plaques, ICAS was an independent predictor for overall vascular events (HR 1.83 [1.10-3.03], p = 0.020), and moderate-severe intracranial stenosis was also an independent predictor for cerebrovascular events (HR 2.66 [1.02-6.94], p = 0.046).

CONCLUSIONS

Asymptomatic ICAS is independently associated with the incidence of future vascular events in our population. These findings might have implications for the development of primary prevention strategies.

Distribution of Cervicocephalic Atherosclerotic Lesions and Their Correlation with Cardiovascular Risk Factors in a Population of Amerindians. The Atahualpa Project

BACKGROUND

No information is available on the distribution of cervicocephalic atherosclerosis in Amerindians. We aimed to assess the distribution of these lesions and their correlation with cardiovascular risk factors in Amerindians living in rural Ecuador.

METHODS

Atahualpa residents aged ≥40years underwent head CT for assessment of carotid siphon calcifications (CSC) and sonographic examination for measurement of the carotid intima media thickness (cIMT). CSC were used as a surrogate of intracranial atherosclerosis and the cIMT as a surrogate of extracranial atherosclerosis. Linear regression and multinomial logistic regression models were fitted to assess the association between cIMT and CSC, and to evaluate differences in risk factors across individuals with atherosclerosis involving both arterial beds when compared with those with extra- or intracranial atherosclerosis alone, or no atherosclerosis.

RESULTS

Of 590 participants, 145 had high calcium content in the carotid siphons and 87 had a cIMT >1mm (25% versus 15%, P < .001). Thirty-eight (7%) individuals had atherosclerosis at both vascular beds, 107 (18%) had intracranial atherosclerosis, and 49 (8%) had extracranial atherosclerosis alone. The cIMT and CSC were independently associated (P = .008). When compared with participants without atherosclerosis, those with atherosclerosis at both vascular beds were older, more often male, hypertensive and diabetic. Subjects with intracranial atherosclerosis alone were older, and those with extracranial atherosclerosis alone reported less physical activity than those without atherosclerosis.

CONCLUSION

Intracranial atherosclerosis is more common than extracranial atherosclerosis in Amerindians. Traditional risk factors only explain a minority of cases of cervicocephalic atherosclerosis in this population.

Differential Features of Culprit Intracranial Atherosclerotic Lesions: A Whole-Brain Vessel Wall Imaging Study in Patients With Acute Ischemic Stroke

Background

Intracranial atherosclerotic disease tends to affect multiple arterial segments. Using whole‐brain vessel wall imaging, we sought to study the differences in plaque features among various types of plaques in patients with a recent unilateral anterior circulation ischemic stroke.

Methods and Results

Sixty‐one patients with unilateral anterior circulation ischemic stroke were referred to undergo whole‐brain vessel wall imaging (before and after contrast) within 1 month of symptom onset for intracranial atherosclerotic disease evaluations. Each plaque was classified as a culprit, probably culprit, or nonculprit lesion, according to its likelihood of causing the stroke. The associations between plaque features (thickening pattern, plaque‐wall contrast ratio, high signal on T1‐weighted images, plaque contrast enhancement ratio, enhancement grade, and enhancement pattern) and culprit lesions were estimated using mixed multivariable logistic regression after adjustment for maximum wall thickness. In 52 patients without motion corruption in whole‐brain vessel wall imaging, a total of 178 intracranial plaques in the anterior circulation were identified, including 52 culprit lesions (29.2%), 51 probably culprit lesions (28.7%), and 75 nonculprit lesions (42.1%). High signal on T1‐weighted images (adjusted odds ratio, 9.1; 95% confidence interval, 1.9–44.1; P=0.006), grade 2 (enhancement ratio of plaque ≥ enhancement ratio of pituitary) contrast enhancement (adjusted odds ratio, 17.4; 95% confidence interval, 1.8–164.9; P=0.013), and type 2 (≥50% cross‐sectional wall involvement) enhancement pattern (adjusted odds ratio, 10.1; 95% confidence interval, 1.3–82.2; P=0.030) were independently associated with culprit lesions.

Conclusions

High signal on T1‐weighted images, grade 2 contrast enhancement, and type 2 enhancement pattern are associated with cerebrovascular ischemic events, which may provide valuable insights into risk stratification.

Potential Impact of COMT-rs4680 G > A Gene Polymorphism in Coronary Artery Disease

Purpose: Catechol-O-methyltransferase (COMT) plays a central role in DNA repair and estrogen-induced carcinogenesis. The nonsynonymous single nucleotide polymorphism (SNP) in exon 4 G > A or Val108 > 158Met or rs4680 G > A influences COMT enzyme activity. The three phenotypes of the COMT enzyme activities include COMT A/A with low enzyme activity, COMT A/G with medium enzyme activity and COMT G/G with high enzyme activity. The Met allele is associated with low enzymatic activity resulting in higher levels of prefrontal dopamine. Conversely, the Val allele is associated with high enzymatic activity and lower levels of prefrontal dopamine. The Met allele has been associated with several psychiatric disorders such as panic disorder. Many recent epidemiologic studies have investigated the association between the COMT Val158Met polymorphism and coronary artery diseases risk, but the results are inconclusive. Therefore our study was aimed to explore the association between COMT Val158Met polymorphism and the risk of coronary artery disease in India. Methology: This study was conducted on 100 clinically confirmed cases of coronary artery diseases and 100 healthy controls. COMT Val158Met genotyping was performed by allele-specific polymerase chain reaction (AS-PCR). Results: A significant correlation was observed in the COMT Val158Met genotype distribution between the coronary artery disease cases and healthy controls (p = 0.008). The frequencies of all three genotypes, GG, GA, AA, reported in the CAD patients were 10%, 70%, and 20%, and 30%, 60%, and 10% in the healthy controls respectively. An increased risk of coronary artery disease was observed in the codominant inheritance model for COMT-GA vs. GG genotype with an OR of 3.5, 95% CI (1.58–7.74) p = 0.002) and COMT-AA vs. GG genotype with an OR of 6.0 95% CI (2.11–17.3) p = 0.003). The higher risk of coronary artery disease was observed in the dominant inheritance model for COMT (GA + AA) vs. GG genotype (OR 3.85, 95% CI 1.76–8.4, p < 0.007), whereas a non-significant association was found in recessive model for COMT (GG + GA vs. AA) (OR = 2.01, 95% CI (0.86–4.7) p = 0.72). The results indicated that A allele significantly increased the risk of coronary artery disease compared to the G allele (OR = 1.8, 95% CI (1.20–2.67) p = 0.004). COMT Val158Met polymorphism leads to a 6.0, 3.5 and 1.8-fold increased risk of developing coronary artery disease in the Indian population and providing novel insights into the genetic etiology and underlying biology of coronary artery disease. Conclusions: It is concluded that COMT-AA genotype and A allele are significantly associated with an increased susceptibility to coronary artery disease in Indian population. A larger sample size can be the key to progress in establishing the genetic co-relationship of COMT polymorphism and cardiovascular disease.

Recent Advances in Primary and Secondary Prevention of Atherosclerotic Stroke

Atherosclerosis is a major cause of ischemic stroke that can be effectively prevented with appropriate lifestyle modifications and control of cardiovascular risk factors. Medical advances in recent years along with aggressive cardiovascular risk factor modifications have resulted in decreased recurrence rates of atherosclerotic stroke. Non-statin lipid-lowering molecules have recently shown clinical benefit and are recommended for very high-risk patients to reduce their risk of stroke. Aggressive hypertension treatment is crucial to reduce atherosclerotic stroke risk. Advances in antithrombotic treatments include combinations of antiplatelets and new antiplatelet agents in the acute phase post-stroke, which carries a high risk of recurrence. Intensive medical treatment has also limited the indications for carotid interventions, especially for asymptomatic disease. Intracranial atherosclerotic disease may provoke stroke through various mechanisms; it is increasingly recognized as a cause of ischemic stroke with advanced imaging and is best managed with lifestyle modifications and medical therapy. The diagnostic search for the vulnerable culprit atherosclerotic plaque is an area of intense research, from the level of the intracranial arteries to that of the aortic arch. Ultrasonography and novel magnetic resonance imaging techniques (high-resolution vessel-wall imaging) may assist in the identification of vulnerable atherosclerotic plaques as the underlying cause in cryptogenic or misdiagnosed non-atherosclerotic ischemic stroke. Vertebrobasilar atherosclerotic disease is less common than carotid artery disease; thus, high-quality data on effective prevention strategies are scarcer. However, aggressive medical treatment is also the gold standard to reduce cerebrovascular disease located in posterior circulation.