Research on intracranial atherosclerosis from the East and west: why are the results different?

Endovascular treatment for proximal middle cerebral artery occlusion due to underlying intracranial atherosclerotic disease: A retrospective single-center case series

OBJECTIVE

To compare treatment outcomes between patients who received a front-line stent-retriever thrombectomy (SRT) or first stenting without retrieval (FRESH) for treating proximal M1 occlusion due to underlying intracranial atherosclerotic disease (ICAD).

METHODS

We retrospectively reviewed consecutive acute ischemic stroke (AIS) patients with intracranial large vessel occlusion (LVO) in the anterior circulation who underwent endovascular treatment (EVT) between January 2017 and August 2021 at Yeungnam University Medical Center. LVO in the anterior circulation was classified according to etiology as follows: Embolic group and ICAD group. Occlusion of the proximal M1 due to ICAD were enrolled in this study. The ICAD group was divided into SRT and FRESH groups according to the treatment method.

RESULTS

Among the 72 patients in the ICAD group, 55 patients had occlusion of the M1, and 27 had occlusion of the proximal M1 (27/55, 49.1 %). Among the 27 patients, 11 (40.7 %) underwent SRT and 16 (59.3 %) underwent FRESH. The puncture-to-recanalization time was significantly shorter in the FRESH group (28 min vs. 52 min, p = 0.023). Symptomatic ICH tended to occur more frequently in the SRT group than in the FRESH group (27.3 % vs. 0.0 %, p=0.056). There was a nonsignificant trend towards a good functional outcome in the FRESH group compared to the SRT group (81.3 % vs. 45.5 %, p=0.097).

CONCLUSION

In the FRESH group, the puncture-to-recanalization time was significantly shorter, symptomatic ICH tended to occur less frequently, and good functional outcomes were more common.

Small vessel disease burden and prognosis of recent subcortical ischaemic stroke differ by parent artery atherosclerosis

BACKGROUND AND PURPOSE

Parent artery atherosclerosis is an important aetiology of recent subcortical ischaemic stroke (RSIS). However, comparisons of RSIS with different degrees of parent artery atherosclerosis are lacking.

METHODS

Prospectively collected data from our multicentre cohort (all were tertiary centres) of the Stroke Imaging Package Study between 2015 and 2017 were retrospectively reviewed. The patients with RSIS defined as a single clinically relevant diffusion-weighted imaging positive lesion in the territory of lenticulostriate arteries were categorized into three subgroups: (1) normal middle cerebral artery (MCA) on magnetic resonance angiography and high-resolution magnetic resonance imaging (HR-MRI); (2) low-grade MCA atherosclerosis (normal or <50% stenosis on magnetic resonance angiography and with MCA plaques on HR-MRI); (3) steno-occlusive MCA atherosclerosis (stenosis ≥50% or occlusion). The primary outcome was 90-day functional dependence (modified Rankin Scale score >2). The clinical and imaging findings were compared between subgroups.

RESULTS

A total of 239 patients (median age 60.0 [52.0-67.0] years, 72% male) were enrolled, including 140 with normal MCA, 64 with low-grade MCA atherosclerosis and 35 with steno-occlusive MCA atherosclerosis. Patients with steno-occlusive MCA atherosclerosis had the largest infarct volume. Low-grade MCA atherosclerosis was independently associated with cerebral microbleeding, more severe perivascular spaces in basal ganglia and higher total cerebral small vessel disease burden. Low-grade MCA atherosclerosis was an independent determinant of 90-day functional dependence (odds ratio 3.897; 95% confidence interval 1.309-11.604).

CONCLUSIONS

Our study suggested RSIS with varying severity of parent artery atherosclerosis exhibits distinctive clinical and neuroimaging characteristics, with low-grade MCA atherosclerosis associating with higher cerebral small vessel disease burden and worse prognosis.

Contemporary Statistics of Acute Ischemic Stroke and Transient Ischemic Attack in 2021: Insights From the CRCS-K-NIH Registry

This report presents the latest statistics on the stroke population in South Korea, sourced from the Clinical Research Collaborations for Stroke in Korea-National Institute for Health (CRCS-K-NIH), a comprehensive, nationwide, multicenter stroke registry. The Korean cohort, unlike western populations, shows a male-to-female ratio of 1.5, attributed to lower risk factors in Korean women. The average ages for men and women are 67 and 73 years, respectively. Hypertension is the most common risk factor (67%), consistent with global trends, but there is a higher prevalence of diabetes (35%) and smoking (21%). The prevalence of atrial fibrillation (19%) is lower than in western populations, suggesting effective prevention strategies in the general population. A high incidence of large artery atherosclerosis (38%) is observed, likely due to prevalent intracranial arterial disease in East Asians and advanced imaging techniques. There has been a decrease in intravenous thrombolysis rates, from 12% in 2017-2019 to 10% in 2021, with no improvements in door-to-needle and door-to-puncture times, worsened by the coronavirus disease 2019 pandemic. While the use of aspirin plus clopidogrel for non-cardioembolic stroke and direct oral anticoagulants for atrial fibrillation is well-established, the application of direct oral anticoagulants for non-atrial fibrillation cardioembolic strokes in the acute phase requires further research. The incidence of early neurological deterioration (13%) and the cumulative incidence of recurrent stroke at 3 months (3%) align with global figures. Favorable outcomes at 3 months (63%) are comparable internationally, yet the lack of improvement in dependency at 3 months highlights the need for advancements in acute stroke care.

Automated identification of thrombectomy amenable vessel occlusion on computed tomography angiography using deep learning

Introduction

We developed and externally validated a fully automated algorithm using deep learning to detect large vessel occlusion (LVO) in computed tomography angiography (CTA).

Method

A total of 2,045 patients with acute ischemic stroke who underwent CTA were included in the development of our model. We validated the algorithm using two separate external datasets: one with 64 patients (external 1) and another with 313 patients (external 2), with ischemic stroke. In the context of current clinical practice, thrombectomy amenable vessel occlusion (TAVO) was defined as an occlusion in the intracranial internal carotid artery (ICA), or in the M1 or M2 segment of the middle cerebral artery (MCA). We employed the U-Net for vessel segmentation on the maximum intensity projection images, followed by the application of the EfficientNetV2 to predict TAVO. The algorithm's diagnostic performance was evaluated by calculating the area under the receiver operating characteristics curve (AUC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

Results

The mean age in the training and validation dataset was 68.7 ± 12.6; 56.3% of participants were men, and 18.0% had TAVO. The algorithm achieved AUC of 0.950 (95% CI, 0.915-0.971) in the internal test. For the external datasets 1 and 2, the AUCs were 0.970 (0.897-0.997) and 0.971 (0.924-0.990), respectively. With a fixed sensitivity of 0.900, the specificities and PPVs for the internal test, external test 1, and external test 2 were 0.891, 0.796, and 0.930, and 0.665, 0.583, and 0.667, respectively. The algorithm demonstrated a sensitivity and specificity of approximately 0.95 in both internal and external datasets, specifically for cases involving intracranial ICA or M1-MCA occlusion. However, the diagnostic performance was somewhat reduced for isolated M2-MCA occlusion; the AUC for the internal and combined external datasets were 0.903 (0.812-0.944) and 0.916 (0.816-0.963), respectively.

Conclusion

We developed and externally validated a fully automated algorithm that identifies TAVO. Further research is needed to evaluate its effectiveness in real-world clinical settings. This validated algorithm has the potential to assist early-career physicians, thereby streamlining the treatment process for patients who can benefit from endovascular treatment.

Clot patterns determined by DSA and CTA can help predict intracranial atherosclerotic stenosis in acute ischemic stroke patients

Background

This study examines whether clot patterns at large artery occlusion sites, as observed using digital subtraction angiography (DSA) and computed tomography angiography (CTA), can reliably indicate intracranial atherosclerotic stenosis (ICAS) in acute ischemic stroke (AIS) patients.

Methods

We conducted a retrospective analysis of patients treated with stent retriever thrombectomy for intracranial occlusions at our institute since 2017, with follow-up assessments conducted at 3 months. The patients were grouped based on the initial angiography clot topographies (i.e., cut-off or tapered signs). We assessed the potential of these topographies in predicting ICAS, including a clinical outcome analysis based on clot pattern, age, Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification, and onset-to-door time.

Results

Among 131 patients (with a mean age of 66.6 years), the clot pattern emerged as a significant predictor of ICAS. The DSA-based model had a predictive area under the curve (AUC) of 0.745, with 55.1% sensitivity and 94.0% specificity. A multivariate model including age, onset-to-door time, TOAST classification as large artery atherosclerosis (LAA), and the presence of the tapered sign in clot patterns had an AUC of 0.916. In patients over 65 years of age with an onset-to-door time of >5 h and exhibiting a tapered sign in the clot pattern, the AUC reached 0.897. The predictive ability of the tapered sign was similar in DSA and CTA, showing 73.4% agreement between modalities.

Conclusion

The clot pattern with the tapered sign as observed using DSA is significantly associated with ICAS. Incorporating this clot pattern with age, TOAST classification as LAA, and onset-to-door time enhances the prediction of ICAS. The clot pattern identified by CTA is also a reliable predictor, highlighting the importance of assessing clot patterns in ICAS identification.

Global intracranial arterial tortuosity is associated with intracranial atherosclerotic burden

The effect of arterial tortuosity on intracranial atherosclerosis (ICAS) is not well understood. This study aimed to evaluate the effect of global intracranial arterial tortuosity on intracranial atherosclerotic burden in patients with ischemic stroke. We included patients with acute ischemic stroke who underwent magnetic resonance angiography (MRA) and classified them into three groups according to the ICAS burden. Global tortuosity index (GTI) was defined as the standardized mean curvature of the entire intracranial arteries, measured by in-house vessel analysis software. Of the 516 patients included, 274 patients had no ICAS, 140 patients had a low ICAS burden, and 102 patients had a high ICAS burden. GTI increased with higher ICAS burden. After adjustment for age, sex, vascular risk factors, and standardized mean arterial area, GTI was independently associated with ICAS burden (adjusted odds ratio [adjusted OR] 1.33; 95% confidence interval [CI] 1.09-1.62). The degree of association increased when the arterial tortuosity was analyzed limited to the basal arteries (adjusted OR 1.48; 95% CI 1.22-1.81). We demonstrated that GTI is associated with ICAS burden in patients with ischemic stroke, suggesting a role for global arterial tortuosity in ICAS.

Dyslipidemia Treatment and Cerebrovascular Disease: Evidence Regarding the Mechanism of Stroke

Dyslipidemia stands as a significant risk factor for stroke, on par with the impact of hypertension, diabetes, and smoking. While the role of dyslipidemia is firmly established in the context of coronary artery disease, its influence on strokes remains somewhat enigmatic. This complexity likely arises from the diverse mechanisms underpinning strokes, which encompass a heterogeneous spectrum (hemorrhagic and ischemic; large artery atherosclerosis, small vessel occlusion, cardioembolism, and etc.). The extent to which lipid-lowering treatments affect stroke outcomes may vary depending on the specific stroke subtype. For instance, in cases of large artery atherosclerosis (LAA), the optimal target level of low-density lipoprotein cholesterol (LDL-C) is relatively clear. However, when dealing with other stroke subtypes like small vessel occlusion or cardioembolism, the appropriate LDL-C target remains uncertain. Furthermore, reperfusion therapy has emerged as the foremost treatment for acute ischemic stroke. Nevertheless, the precise relationship between LDL-C levels and outcomes in patients undergoing reperfusion therapy remains shrouded in uncertainty. Consequently, we have undertaken an in-depth exploration of the existing evidence supporting the utilization of lipid-lowering medications such as statins, ezetimibe, and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors. Our objective is to elucidate their role in secondary stroke prevention and the management of dyslipidemia across the various stroke subtypes.

Triglyceride-Related Parameters and Symptomatic Atherosclerotic Lesions in Patients With Ischemic Stroke

Objective

Recently, evidence has suggested that the pathophysiology and risk factors of intracranial atherosclerosis (ICAS) differs from those of extracranial atherosclerosis (ECAS). In addition, novel parameters reflecting metabolic conditions, such as insulin resistance or atherogenic dyslipidemia, based on triglycerides (TG) and other biomarkers, have emerged. In this study, we evaluated the association between TG-related parameters and symptomatic cerebral atherosclerosis in patients with acute ischemic stroke resulting from large artery atherosclerosis (LAA).

Methods

We assessed consecutive acute LAA-stroke patients between January 2010 and December 2020. Based on the radiological findings, we classified the relevant symptomatic arteries that caused the index stroke into LAA-ICAS and LAA-ECAS. As TG-related parameters, the atherogenic index of plasma (AIP) and TG-glucose (TyG) index were calculated according to the following formulas: AIP = log10 (TG Level/High-density Lipoprotein Cholesterol Level), TyG Index = Ln (TG Level × Glucose Level/2).

Results

A total of 519 patients with LAA-stroke were evaluated. In multivariable logistic regression analysis to identify predictors of LAA-ICAS, AIP was significantly associated with LAA-ICAS (adjusted odds ratio [aOR], 3.60; 95% confidence interval [CI], 1.60-8.06). TyG index also showed a statistically significant relationship with LAA-ICAS (aOR, 1.60; 95% CI, 1.11-2.32). However, TG per se did not show a statistical association with LAA-ECAS.

Conclusion

TG-related parameters were more closely associated with stroke by ICAS than by ECAS. The metabolic conditions reflected by the AIP or TyG index, rather than hypertriglyceridemia itself, may play a greater role in determining the relevant vessel causally involved in a stroke.

The impact of pre-stroke aspirin exposure on radiographic appearance and disability outcomes: A post-hoc analysis of the SPS3 trial: Aspirin Use and Small Subcortical Stroke

OBJECTIVES

The effect of pre-stroke use of aspirin on small subcortical infarct dimensions or outcomes is not well described. We aimed to bridge this knowledge gap amongst a well-described and heterogeneous patient population.

MATERIALS AND METHODS

We performed a post-hoc analysis of the Secondary Prevention of Small Subcortical Stroke (SPS3) trial. The primary exposure was aspirin use ≤7 days of index stroke. The primary outcomes were infarct dimensions. Functional outcomes by modified Rankin Scale (mRS) was a secondary outcome. Age restricted (≥55 years) subgroup analyses were performed as a sensitivity analysis. Descriptive statistical and regression modeling were performed for data analysis.

RESULTS

We included 1423 participants of which 453(31.8 %) used aspirin. Aspirin use was associated with more cardiovascular risk diagnoses. Maximal infarct diameter did not differ with pre-stroke aspirin use (11.3±4.2 mm versus 11.8±4.1 mm, p=0.057) however infarct area was smaller with exposure (126.4±90.0 mm2 versus 137.4±97.0 mm2, p=0.037) regardless of aspirin strength. Participants ≥55 years had smaller infarct diameters (11.1±4.2 mm versus 11.9±4.4 mm, p=0.019) and area (123.4±87.1 mm2 versus 130.6±93.2 mm2, p=0.037) with aspirin use. mRS did not significantly differ in our analyses.

CONCLUSIONS

In this post-hoc analysis of the SPS3 trial, pre-stroke aspirin use was associated with a smaller infarct area regardless of aspirin strength and without impact on functional outcomes. These findings were more pronounced in participants ≥55 years.

REGISTRATION

https://clinicaltrials.gov/study/NCT00059306?term= %22sps3 %22&rank=1.

Superficial Temporal Artery-to-Middle Cerebral Artery Bypass in Ischemic Stroke With Blood Pressure-Dependent Symptoms

The efficacy of extracranial-intracranial (EC-IC) bypass in preventing ischemic stroke progression and recurrence is controversial. As per the current hypothesis, EC-IC bypass is most beneficial for patients with persistent hemodynamic insufficiency. Hence, various approaches have been used to evaluate hemodynamic insufficiency, including repeated single photon emission CT (SPECT) imaging or continuous monitoring of cerebral flow with transcranial Doppler ultrasound (TCD). However, both modalities are time- and resource-intensive. In this report, we discuss how EC-IC bypass turned out to be beneficial for a patient presenting with blood pressure-dependent severe aphasia and right hemiparesis due to middle cerebral artery (MCA) occlusion that failed thrombectomy. CT perfusion (CTP) scan at admission demonstrated a persistent volume of delayed perfusion without core infarct. Following the superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass, the patient's National Institute of Health Stroke Scale (NIHSS) score improved from 12 to 1. Ischemic penumbra, as seen on CTP imaging, also improved after the STA-MCA bypass. Our case suggests that persistent volume of delayed perfusion and blood pressure-dependent neurological deficits can be used in tandem as selection criteria for EC-IC bypass.

Intracranial arteriosclerosis and the risk of dementia: A population-based cohort study

BACKGROUND

The impact of intracranial arteriosclerosis on dementia remains largely unclear.

METHODS

In 2339 stroke-free and dementia-free participants (52.2% women, mean age 69.5 years) from the general population, we assessed intracranial carotid artery calcification (ICAC) and vertebrobasilar artery calcification (VBAC) as proxy for arteriosclerosis. Associations with dementia were assessed using Cox models. In addition, indirect effects through cerebral small vessel disease (cSVD) and subcortical brain structure volumes were assessed using causal mediation analyses.

RESULTS

During a median of 13.4 years (25th-75th percentiles 9.9-14.5) of follow-up, 282 participants developed dementia. Both ICAC presence (hazard ratio [HR]: 1.53, 95% confidence interval [CI]: 1.00-2.32]) and volume (HR per standard deviation: 1.19, 95% CI: 1.01-1.40) increased dementia risk. For VBAC, severe calcifications increased dementia risk (HR for third vs first volume tertile: 1.89, 95% CI: 1.00-3.59). These effects were mediated partly through increased cSVD (percentage mediated for ICAC: 13% and VBAC: 24%).

DISCUSSION

Intracranial arteriosclerosis increases the risk of dementia.

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.

Characteristics and evaluation of atherosclerotic plaques: an overview of state-of-the-art techniques

Atherosclerosis is an important cause of cerebrovascular and cardiovascular disease (CVD). Lipid infiltration, inflammation, and altered vascular stress are the critical mechanisms that cause atherosclerotic plaque formation. The hallmarks of the progression of atherosclerosis include plaque ulceration, rupture, neovascularization, and intraplaque hemorrhage, all of which are closely associated with the occurrence of CVD. Assessing the severity of atherosclerosis and plaque vulnerability is crucial for the prevention and treatment of CVD. Integrating imaging techniques for evaluating the characteristics of atherosclerotic plaques with computer simulations yields insights into plaque inflammation levels, spatial morphology, and intravascular stress distribution, resulting in a more realistic and accurate estimation of plaque state. Here, we review the characteristics and advancing techniques used to analyze intracranial and extracranial atherosclerotic plaques to provide a comprehensive understanding of atheroma.

Outcomes of Endovascular Treatment versus Standard Medical Treatment for Acute Ischemic Stroke with Basilar Artery Occlusion: A Systematic Review and Meta-Analysis

BACKGROUND

Although endovascular treatment (EVT) is beneficial for large vessel occlusion in anterior circulation stroke, whether these benefits exist for basilar artery occlusion (BAO) remains unclear. This systematic review and meta-analysis compared the outcomes of patients with BAO undergoing EVT and standard medical treatment (SMT).

METHODS

The PubMed, Embase, and Cochrane Library databases were searched for eligible randomized control trials (RCTs) and non-RCTs involving patients with acute ischemic stroke and BAO undergoing EVT or SMT. The following outcomes were assessed: 90-day functional outcomes (favorable outcome and functional independence: modified Rankin scale [mRS] score of 0-3 or 0-2, respectively), mortality, and symptomatic intracranial hemorrhage (sICH) incidence. The summary effect sizes were determined as risk ratios (RRs) through the Mantel-Haenszel method with a random-effects model.

RESULTS

Four RCTs and four non-RCTs were included. Compared with SMT, EVT resulted in a higher proportion of patients with 90-day mRS scores of 0-3 (RR: 1.54 [1.16-2.06] in RCTs and 1.88 [1.11-3.19] in non-RCTs), a higher proportion of patients achieving functional independence (90-day mRS score of 0-2; RR: 1.83 [1.07-3.12] and 1.84 [0.97-3.48], respectively), a lower risk of mortality (RR: 0.76 [0.65-0.89] and 0.72 [0.62-0.83], respectively), and a higher sICH risk (RR: 5.98 [2.11-16.97] and 4.95 [2.40-10.23], respectively). Severe neurological deficits, intravenous thrombolysis, and higher posterior circulation Acute Stroke Prognosis Early Computed Tomography Score (pc-ASPECTS) were associated with EVT benefits.

CONCLUSION

In patients with BAO, EVT results in superior functional outcomes, lower mortality risk, and higher sICH risk than does SMT, independent of age and sex. Higher National Institutes of Health Stroke Scale scores, intravenous thrombolysis, and higher pc-ASPECTSs before treatment are associated with greater benefits from EVT.

Lipidomic Approaches in Common and Rare Cerebrovascular Diseases: The Discovery of Unconventional Lipids as Novel Biomarkers

Stroke remains a major cause of death and disability worldwide. Identifying new circulating biomarkers able to distinguish and monitor common and rare cerebrovascular diseases that lead to stroke is of great importance. Biomarkers provide complementary information that may improve diagnosis, prognosis and prediction of progression as well. Furthermore, biomarkers can contribute to filling the gap in knowledge concerning the underlying disease mechanisms by pointing out novel potential therapeutic targets for personalized medicine. If many "conventional" lipid biomarkers are already known to exert a relevant role in cerebrovascular diseases, the aim of our study is to review novel "unconventional" lipid biomarkers that have been recently identified in common and rare cerebrovascular disorders using novel, cutting-edge lipidomic approaches.

Tmax Mismatch Ratio to Identify Intracranial Atherosclerotic Stenosis-Related Large-Vessel Occlusion Before Endovascular Therapy

Background We aimed to clarify which time-to-maximum of the tissue residue function (Tmax) mismatch ratio is useful in predicting anterior intracranial atherosclerotic stenosis (ICAS)-related large-vessel occlusion (LVO) before endovascular therapy. Methods and Results Patients with ischemic stroke who underwent perfusion-weighted imaging before endovascular therapy for anterior intracranial LVO were divided into those with ICAS-related LVO and those with embolic LVO. Tmax ratios of >10 s/>8 s, >10 s/>6 s, >10 s/>4 s, >8 s/>6 s, >8 s/>4 s, and >6 s/>4 s were considered Tmax mismatch ratios. Binominal logistic regression was used to identify ICAS-related LVO, and the adjusted odds ratio (aOR) and 95% CI for each Tmax mismatch ratio increase of 0.1 were calculated. A similar analysis was performed for ICAS-related LVO with and without embolic sources, using embolic LVO as the reference. Of 213 patients (90 women [42.0%]; median age, 79 years), 39 (18.3%) had ICAS-related LVO. The aOR (95% CI) per 0.1 increase in Tmax mismatch ratio in ICAS-related LVO with embolic LVO as reference was lowest with Tmax mismatch ratio >10 s/>6 s (0.56 [0.43-0.73]). Multinomial logistic regression analysis also showed the lowest aOR (95% CI) per 0.1 increase in Tmax mismatch ratio with Tmax >10 s/>6 s (ICAS-related LVO without embolic source: 0.60 [0.42-0.85]; ICAS-related LVO with embolic source: 0.55 [0.38-0.79]). Conclusions A Tmax mismatch ratio of >10 s/>6 s was the optimal predictor of ICAS-related LVO compared with other Tmax profiles, with or without an embolic source before endovascular therapy. Registration clinicaltrials.gov. Identifier NCT02251665.

Evaluation of safety and efficacy of rapamycin-eluting balloon in patients with intracranial atherosclerotic stenosis: a cohort study

OBJECTIVE

The safety and efficacy of drug-eluting balloon on the treatment of intracranial atherosclerotic stenosis (ICAS) remain unclear. Here, we present our observation in a cohort study on the safety and efficacy of rapamycin-eluting balloon for patients with ICAS.

METHODS

A total of 80 ICAS patients with stenosis degree of 70-99% were included. All patients were treated with rapamycin-eluting balloon and were followed up for 12 months after operation.

RESULTS

All patients were successfully treated, where the mean stenosis severity reduced from 85.1 ± 7.6 to 6 ± 4.9%. 8 patients experienced immediate post-operational complications. Two patients passed away during the first month of the follow-up period. Recurrent ischemic syndrome and angiographic restenosis only appeared 7 days after operation. During later follow-up period, none of the patients had clinical angiographic restenosis or needed target vessel revascularization.

CONCLUSION

Our data suggest that intracranial stenting with rapamycin-eluting balloon seems to be safe and effective, although more clinical data are needed to support this notion.

Angioplasty, stenting, or both - rescue maneuvers and reperfusion after endovascular therapy for intracranial atherosclerosis-related occlusion

PURPOSE

Data concerning reperfusion strategies of intracranial atherosclerosis-related occlusion (ICARO) and clinico-angiographic outcomes remain scarce, particularly in Caucasians. We aim to compare the reperfusion rate and functional outcome between reperfusion strategies in the setting of the ICARO.

METHODS

Retrospective analysis of prospectively maintained endovascular thrombectomy (EVT) registries at three high-volume stroke centers were retrospectively analyzed for consecutive ICARO patients from January 2015 to December 2019. We defined ICARO as any fixed high-degree (> 70%) focal narrowing or stenosis of any degree with a perpetual tendency for reocclusion. We categorized reperfusion strategies into four groups: EVT [group 1], balloon angioplasty [(BAp), group 2], placement of self-expandable stents [(SES), group 3], and BAp combined with implantation of SES; or direct placement of balloon mounted stents (BMS) [(BAp-SES/BMS), group 4]. We evaluated the association with the successful reperfusion [mTICI 2b - 3] and favorable outcome [mRS 0-2] with logistic regression analysis.

RESULTS

Out of 2550 EVT, 124 patients (median age, 70 (61-80) years; 76 men) with ICARO and 130 reperfusion attempts [36 EVT, 38 BAp, 17 SES, and 39 BAp + SES/BMS] were analyzed. SES implantation showed the highest frequency of post-procedural symptomatic intracranial hemorrhage [(18%, 3/17), p = .03]; however, we observed no significant differences in the mortality rate. Overall, we achieved successful reperfusion in 71% (92/130) and favorable outcomes in 42% (52/124) of the patients. BAp + SES/BMS was the only independent predictor of the final successful reperfusion [aOR, 4.488 (95% CI, 1.364-14.773); p = .01], which was significantly associated with the 90-day favorable outcome [aOR, 10.837 (95% CI, 3.609-32.541); p =  < .001] after adjustment for confounding variables between the reperfusion strategies.

CONCLUSION

Among patients with ICARO, the rescue angioplasty stenting effectively contributed to higher odds of successful reperfusion with no increased risk for intracranial hemorrhage.

Untreated hypertension and prognosis paradox in acute ischemic stroke

INTRODUCTION

This study is to explore the long-term functional outcome of antihypertensive medication-naïve, untreated hypertension (HTN) patients with acute ischemic stroke compared to those with no prior HTN and those with treated HTN.

PATIENTS AND METHODS

We analyzed a prospectively collected stroke registry of all patients with acute ischemic stroke consecutively admitted to Incheon St. Mary's Hospital. Patients who received reperfusion therapy were excluded. Long-term functional outcomes were assessed at a 3-month follow-up visit using the modified Rankin Scale.

RESULTS

A total of 1044 patients was enrolled. Compared to patients with no or treated HTN, those with untreated HTN had higher odds for more favorable outcomes (adjusted odds ratio (OR): 1.7 [95% CI: 1.0-2.7, p = 0.050*] and 1.7 [95% CI: 1.0-2.8, p = 0.047*], respectively) when the stroke was large vessel atherosclerosis (LAA)/cardioembolic (CE) with large vessel occlusion/stenosis. However, no such association was observed when there was no large vessel occlusion or stenosis, in total patients, or if the index stroke was related to SVO. In untreated HTN patients with LAA/CE and large vessel occlusion/stenosis compared to patients in the lowest mean arterial pressure quartile (< 96.7 mmHg), patients in the second and third highest quartiles had higher odds of favorable outcomes.

CONCLUSIONS

Patients with untreated HTN had significantly more favorable outcomes at 3 months after ischemic stroke compared to those with no or treated HTN when the stroke was LAA/CE with large vessel occlusion/stenosis. Untreated HTN patients also showed an association between higher MAP and favorable outcomes.

Research progress on risk factors related to intracranial artery, carotid artery, and coronary artery stenosis

In recent decades, with the rapid development of economy, the acceleration of social aging and urbanization, and the prevalence of unhealthy lifestyles, the number of patients with cardiovascular and cerebrovascular diseases has shown an increasing trend year by year. It has also become one of the important causes of disability and death in all ages and groups. Atherosclerosis is the main pathological change of ischemic cardiovascular and cerebrovascular diseases, which mainly invades the large and medium arteries of the body circulation. In particular, cerebral artery and coronary artery lesions have the most significant impact on life. There is the same pathogenic mechanism between intracranial and extracranial arteries and coronary atherosclerosis, so there is a certain relationship between the degree of atherosclerosis. In this paper, the risk factors related to intracranial and extracranial arteries and coronary artery stenosis were reviewed. It provides a theoretical basis for early detection, early diagnosis and early treatment of intracranial and extracranial artery and coronary artery stenosis to reduce the occurrence and development of cardiovascular and cerebrovascular diseases.

Movement Disorders Associated With Cerebral Artery Stenosis: A Nationwide Study

Background

Studies of secondary movement disorder (MD) caused by cerebrovascular diseases have primarily focused on post-stroke MD. However, MD can also result from cerebral artery stenosis (CAS) without clinical manifestations of stroke. In this study, we aimed to investigate the clinical characteristics of MD associated with CAS.

Materials and Methods

A nationwide multicenter retrospective analysis was performed based on the data from patients with CAS-associated MDs from 16 MD specialized clinics in South Korea, available between January 1999 and September 2019. CAS was defined as the >50% luminal stenosis of the major cerebral arteries. The association between MD and CAS was determined by MD specialists using pre-defined clinical criteria. The collected clinical information included baseline demographics, features of MD, characteristics of CAS, treatment, and MD outcomes. Statistical analyses were performed to identify factors associated with the MD outcomes.

Results

The data from a total of 81 patients with CAS-associated MD were analyzed. The mean age of MD onset was 60.5 ± 19.7 years. Chorea was the most common MD (57%), followed by tremor/limb-shaking, myoclonus, and dystonia. Atherosclerosis was the most common etiology of CAS (78%), with the remaining cases attributed to moyamoya disease (MMD). Relative to patients with atherosclerosis, those with MMD developed MD at a younger age (p < 0.001) and had a more chronic mode of onset (p = 0.001) and less acute ischemic lesion (p = 0.021). Eight patients who underwent surgical treatment for CAS showed positive outcomes. Patients with acute MD onset had a better outcome than those with subacute-to-chronic MD onset (p = 0.008).

Conclusions

This study highlights the spectrum of CAS-associated with MD across the country. A progressive, age-dependent functional neuronal modulation in the basal ganglia due to CAS may underlie this condition.

Clinical Manifestation and Radiologic Patterns of Spontaneous Cervicocephalic Dissection According to the Anatomic Location: A Single-Center Analysis in Korean Patients

PURPOSE

Spontaneous cervicocephalic dissection (SCAD) is an important cause of stroke and shows various lesion locations and clinical features. The purpose of this study was to analyze the location of SCAD and its clinical and radiologic patterns in Korean patients.

MATERIALS AND METHODS

Patients with SCAD who were evaluated between 2013 and 2018 at a tertiary center in Korea were reviewed. We classified and compared the morphological (aneurysm or steno-occlusion) and presenting (hemorrhage or infarction) patterns according to the lesion locations (anterior circulation [AC] vs. posterior circulation [PC]; intradural [ID] vs. extradural [ED]).

RESULTS

A total of 166 patients were included in this study. The SCAD most commonly occurred in the PC-ID location (65.1%), followed by AC-ID (13.3%), AC-ED (13.3%), and PC-ED (8.4%). Aneurysm and steno-occlusion patterns were observed in 66.9% and 57.8% of the cases, respectively. The aneurysm pattern was significantly more common in the PC-ID location (78.7%) than in other locations. As for the presenting pattern, cerebral infarction was the most common pattern (39.8%), and intracranial hemorrhage was observed only in the ID location (7.2%).

CONCLUSION

In Korean patients, PC-ID, especially ID vertebral artery, was the most common location of SCAD, and most cases were accompanied by an aneurysm. It also suggested that these location trends differ by population or ethnicity.

Number of cerebral microbleeds after intracranial/extracranial stenting and dual antiplatelet therapy

BACKGROUND

Cerebral microbleeds (CMBs) are small (<1 cm) perivascular hemosiderin depositions. They may be visible in T2* or susceptibility-weighted magnetic resonance imaging (MRI) sequences. CMBs may indicate an increased risk of intracerebral hemorrhage (ICH) or vascular disease. Cerebral white matter changes indicate small vessel disease (SVD), which is also related to CMBs. In cerebral vascular treatment, dual antiplatelet therapy (DAPT) is routinely used after stenting. We surveyed our cerebral stenting case series for changes in the number of CMBs.

METHODS

Patients receiving extracranial or intracranial stenting between 2018 and 2020 were included. All patients received DAPT after stenting. Changes in CMBs, SVD degree, and other findings from pretreatment to follow-up MRI were recorded. Differences between stented artery supplying territory and other territories were compared.

RESULTS

The average age of the 75 enrolled patients was 65.37 years ± 11.53 (50 male and 25 female patients); 84 extracranial or intracranial stentings were performed. The average Fazekas scale score was 1.32 ± 0.77. Significantly more CMBs developed in the initial ≥6 CMB group than in the initial 0 and 1-5 CMB groups (7 ± 3.6 vs 0.56 ± 1.06, 1.45 ± 3.32, p < 0.001). No significant difference in increased CMBs was observed between the initial 0 and 1-5 CMB groups. Significantly more CMBs developed in the stented artery supplying territory than elsewhere (0.6 ± 0.13 vs 0.44 ± 0.17, p < 0.05). No ICH was noted in our case series.

CONCLUSION

Preexisting CMB was a risk factor for the onset of new CMBs after stenting and DAPT. Poststenting and DAPT statistically increased CMBs in stented artery supplying territories at short-term follow-up.

Silent brain infarction is associated with carotid siphon calcification in ischemic stroke patients

BACKGROUND

Silent brain infarction (SBI) had a higher prevalence in ischemic stroke patients than healthy population. Intracranial artery calcification, as the important component of atherosclerosis, is a known risk factor of ischemic stroke. Whether it is also the risk factor of SBI is uncertain. We aimed to assess the association between SBI and carotid siphon calcification (CSC) in ischemic stroke patients.

METHODS

We retrospectively collected consecutive data of acute ischemic stroke patients with and without SBI by Magnetic Resonance Imaging (MRI) and calcification using non-contrast Computerized Tomography (NCCT). We used a histopathologically validated method to score the circularity, thickness, and morphology of calcification. Clinical characteristics, prevalence and pattern (intimal and medial) of CSC were compared between patients with and without SBI. The association of CSC and SBI was investigated by logistic regression analysis.

RESULTS

Totally, 303 acute ischemic stroke patients were enrolled, of whom 260 (85.8%) had CSC. Patients with SBI were older (64.5 ± 10.4 years vs. 61.3 ± 12.1 years, P = 0.032), had a higher proportion of hypertension (77.5% vs. 65.7%, P = 0.035). Of the 260 CSC patients, there's no significant difference except for hyperlipidemia between patients with SBI and without SBI. The prevalence of intimal pattern of CSC was higher in those with SBI (adjusted odds ratio 2.42, 95% CI 1.219-4.794).

CONCLUSIONS

Patients with SBI at acute phase of ischemic stroke have more risk factors than mentioned previously. SBI associated with the intimal pattern of CSC which relate to the atherosclerosis process in symptomatic ischemic stroke patients.

Isolated pontine infarction versus pontine plus infarction: prevalence, pathogenic mechanism, and outcomes

BACKGROUND

Pontine infarctions are often associated with extrapontine infarcts. We aimed to elucidate differences in clinical characteristics, mechanisms, and functional outcomes between isolated pontine infarction (IPI) and pontine plus infarction (PPI).

METHODS

We studied patients with acute pontine infarction between January 2019 and August 2021 and divided them into IPI and PPI according to diffusion-weighted magnetic resonance image. Vertical locations were classified into rostral, middle, and caudal, and horizontal locations were categorized as basal/tegmental and unilateral/bilateral. Factors associated with poor 90-day outcome (modified Rankin scale 3-6) were analyzed.

RESULTS

Among 241 patients, 170 (70.5%) had IPI and 71 (29.5%) had PPI. The most frequently observed extrapontine areas were cerebellar (59.1%), followed by posterior cerebral artery territory (45.1%). Mental status changes, sensory changes, and ataxia were more common, and motor dysfunction was less common in PPI patients. The PPI patients more often had rostral (P < 0.001), bilateral lesions (P < 0.001), and moderate/severe vascular stenosis and atrial fibrillation; therefore, large artery disease (LAD) and cardioembolism were more common stroke mechanisms (P < 0.001). In IPI patients, high initial National Institutes of Health Stroke Scale (NIHSS) (adjusted Odds ratio (OR) = 1.38; P = 0.001) and old age (aOR = 1.05; P = 0.049) were associated with poor functional outcome, whereas moderate/severe stenosis (Reference: no stenosis, aOR = 7.17; P = 0.014) and high initial NIHSS (aOR = 1.39; P = 0.006) were related to unfavorable outcomes in PPI patients.

CONCLUSIONS

PPI patients more often had extensive pontine lesions, LAD and cardioembolism, and their outcome was more often influenced by underlying severe vascular diseases. These differences need to be considered in the prevention and therapeutic strategies.

Application of drug-coated balloons for intracranial atherosclerosis disease: a systematic review

BACKGROUND

Although percutaneous transluminal angioplasty and stenting (PTAS) was an effective and safe alternative treatment for severe intracranial atherosclerosis disease (ICAD), the high rate of restenosis remained a major issue for this endovascular procedure. Recently, the application of drug-coated balloons (DCB) in ICAD was developed to reduce restenosis. This systematic review aimed to evaluate the efficacy and safety of DCB angioplasty for ICAD.

METHODS

We searched relevant databases for eligible studies enrolling ICAD patients treated with DCB. The event rates of restenosis and periprocedural complications in the follow-up period were pooled with random-/fixed-effect models using Freeman-Tukey double arcsine transformation. Heterogeneity tests and publication bias tests were performed.

RESULTS

Two hundred and twenty-four ICAD patients treated with DCB from 9 eligible studies were included. Rate of stenosis in the DCB arm before treatment was ranged from 62% to 90% and reported median follow-up was ranged from 3 to 10.7 months. The pooled incidence of restenosis were 5.7% (95% confidence interval [CI] 2.6%-9.7%; I² = 0%, p = 0.516) and 5.9% for periprocedural complications (95% CI: 2.5-10.3%; I² = 0%, p = 0.649) in follow-up term.

CONCLUSION

With the limitation of the low quality of the available evidence, angioplasty with DCB appears to be effective and safe in severe ICAD. Further larger randomized trials are needed to provide more definitive evidence and to address the ideal clinical context for their application.

A clinical study of 288 patients with anterior cerebral artery infarction

OBJECTIVE

Acute ischemic stroke in the territory of anterior cerebral artery (ACA) is uncommon. Therefore, large population studies evaluating ACA infarction are scarce. We sought to evaluate epidemiological and etiological characteristics of ACA infarction compared to other territorial infarctions.

METHODS

We analyzed a prospectively collected stroke registry of all acute ischemic stroke patients for 19 years at two tertiary hospitals. We included patients with acute ischemic stroke caused by large vessel stenosis or occlusion including ACA, middle cerebral artery (MCA), posterior cerebral artery (PCA), and vertebrobasilar artery (VBA).

RESULTS

A total of 4171 patients were enrolled. Patients with ACA infarction (N = 288) were significantly older with more females than those with MCA, PCA, or VBA infarction. There were more patients with history of prior ischemic stroke in the ACA infarction group than in other groups. The etiology of the ACA infarction was similar to those of the MCA, PCA and also the total population (66.7-71.8% of LAA and 17.9-20.9% of CE). When patients had prior ischemic stroke history, ACA infarction was more likely to be caused by LAA than MCA or PCA infarction (OR = 6.2, 95% CI 2.0-19.2, p = 0.002 and OR = 4.0, 95% CI 1.1-14.6, p = 0.038, respectively).

CONCLUSIONS

Patients with ACA infarction had significantly more prior ischemic stroke than those with MCA, PCA, or VBA infarction. The etiology of ACA infarction in patients with prior ischemic stroke showed significantly more LAA than that of MCA or PCA infarction.

Preprocedural Imaging : A Review of Different Radiological Factors Affecting the Outcome of Thrombectomy

BACKGROUND

Endovascular treatment (EVT) has strong evidence for its effectiveness in treatment of acute ischemic stroke (AIS); however, up to half of the patients who undergo EVT still do not have good functional outcomes. Various prethrombectomy radiological factors have been shown to be associated with good clinical outcomes and may be the key to better functional outcomes, reduced complications, and reduced mortality. In this paper, we reviewed the current literature on these imaging parameters so they can be employed to better estimate the probability of procedural success, therefore allowing for more effective preprocedural planning of EVT strategies. We reviewed articles in the literature related to imaging factors which have been shown to be associated with EVT success. The factors which are reviewed in this paper included: anatomical factors such as 1) the type of aortic arch and its characteristics, 2) the characteristics of the thrombus such as length, clot burden, permeability, location, 3) the middle cerebral artery features including the tortuosity and underlying intracranial stenosis, 4) perfusion scans estimating the volume of infarct and the penumbra and 5) the effect of collaterals on the procedure. The prognostic effect of each factor on the successful outcome of EVT is described. The identification of preprocedural thrombectomy imaging factors can help to improve the chances of recanalization, functional outcomes, and mortality. It allows the interventionist to make time-sensitive decisions in the treatment of acute ischemic stroke.

Prevalence, prognosis, and treatment of atherosclerotic intracranial stenosis in Caucasians

BACKGROUND

Intracranial atherosclerotic stenosis is a highly prevalent cause of stroke worldwide with important ethnic disparities. Widely considered to be a common cause of stroke in Asian and Afro-Caribbean populations, relatively less is known about the burden and significance of intracranial atherosclerotic stenosis in Caucasians.

AIMS

We aim to highlight recent insights and advances into the prevalence, prognosis, and treatment of symptomatic and asymptomatic atherosclerotic intracranial atherosclerotic stenosis in Caucasian patients.

SUMMARY OF REVIEW

We identified 48 articles studying intracranial atherosclerotic stenosis in Caucasian patients with ischemic stroke or transient ischemic attack. Most studies were on hospital-based cohorts of consecutive patients and half were graded as "fair" quality. There was significant variation between studies in the definition of intracranial atherosclerotic stenosis and in the imaging modalities used to detect intracranial atherosclerotic stenosis. Overall, 12.1% of Caucasian patients were found to have any intracranial atherosclerotic stenosis, 6.4% symptomatic intracranial atherosclerotic stenosis and 11.1% asymptomatic intracranial atherosclerotic stenosis, with higher rates at older ages. In studies reporting prognosis, there were 61 and 10 same-territory ischemic strokes in 1000 person-years in patients with symptomatic and asymptomatic intracranial atherosclerotic stenosis, respectively. Percutaneous stenting and angioplasty have not proven superior to intensive medical management in patients with symptomatic intracranial atherosclerotic stenosis.

CONCLUSIONS

Intracranial atherosclerotic stenosis has previously been neglected as a cause of stroke in Caucasians but is highly prevalent at older ages and frequently discovered with the growing use of noninvasive angiography. Intensive medical therapy is the treatment of choice, but there is a need to develop novel treatments or therapeutic approaches to lower the risk of stroke in higher risk patients.

Risk of Stroke in Systemic Necrotizing Vasculitis: A Nationwide Study Using the National Claims Database

Objective

Evidences indicate that the risk of stroke is increased in autoimmune rheumatic diseases. This study aimed to investigate the incidence of stroke in patients with systemic necrotizing vasculitis (SNV) using the national health database.

Methods

Data were obtained from the Korean National Claims database between 2010 and 2018 to identify incident SNV [anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) and polyarteritis nodosa (PAN)] cases. The standardized incidence ratio (SIR) and incidence rate ratio (IRR) were calculated to estimate the risk of stroke in patients with SNV compared to the general population and among disease subgroups. Time-dependent Cox's regression analysis was performed to identify risk factors for stroke.

Results

Among 2644 incident SNV cases, 159 patients (6.0%) were affected by stroke. The overall risk of stroke was significantly higher in patients with SNV compared to the general population (SIR 8.42). Stroke event rates were the highest within the first year of SNV diagnosis (67.3%). Among disease subgroups, patients with microscopic polyangiitis (MPA) exhibited higher IRR compared to PAN (adjusted IRR 1.98). In Cox's hazard analysis, older age and MPA were associated with higher risk of stroke [hazard ratio (HR) 1.05 and 1.88], whereas the administration of cyclophosphamide, azathioprine/mizoribine, methotrexate, and statins were protective in stroke (HR 0.26, 0.34, 0.49, and 0.50, respectively).

Conclusion

A considerable number of SNV patients experienced stroke, especially in the early phase of disease. Older age and MPA diagnosis were associated with elevated risk of stroke, while the administration of immunosuppressive agents and statins was beneficial in preventing stroke.

Direct Stenting of Intracranial Atherosclerosis-related Acute Large Vessel Occlusion

PURPOSE

Endovascular reperfusion therapy (ERT) in patients with intracranial atherosclerosis (ICAS)-related acute large vessel occlusion (ALVO) may require different strategies based on the underlying culprit plaque lesion. This study investigated the effectiveness and safety of direct stent placement in ICAS-related ALVO compared with initially attempted mechanical thrombectomy (MT) with or without rescue treatment.

METHODS

Direct stenting for ICAS-related ALVO was performed in 30 consecutive patients between January 1, 2012, and December 31, 2018. As a control for comparison, MT with or without rescue stenting for patients with ICAS-related ALVO was performed in 73 consecutive patients during the same period. Clinical outcomes were assessed by measuring modified Rankin Scale (mRS) at 90 days.

RESULTS

Patients who underwent direct stenting and those who underwent MT with or without rescue stenting showed no significant differences in baseline characteristics. There was a higher proportion of patients with mRS 0-2 at 90 days in the direct stenting group than in the MT with or without rescue stenting group [24 (80.0%) vs. 34 (46.6%); p = 0.004]. Successful recanalization to modified thrombolysis in cerebral infarction category 2b or 3 was achieved in 93.3% of patients who underwent direct stenting, and in 90.4% of patients who underwent MT with or without rescue stenting.

CONCLUSION

Direct stenting is an effective and safe option for ICAS-related ALVO. Further studies are needed to confirm that endovascular treatments are effective and safe in patients with ALVO and underlying ICAS.

Immediate effects of first-line thrombectomy devices for intracranial atherosclerosis-related occlusion: stent retriever versus contact aspiration

BACKGROUND

Although stent retriever (SR) is recommended as a frontline device of endovascular treatment (EVT) for embolic large artery occlusion causing acute ischemic stroke, contact aspiration (CA) device showed similar efficacy in the recent trials. However, the efficacy of the both devices as first-line therapy for intracranial atherosclerotic stenosis (ICAS)-related large vessel occlusion has not yet been established. Therefore, we compared the immediate effects and final outcomes of SR and CA as first-line devices for treating ICAS-related occlusions.

METHODS

We retrospectively analyzed the data of patients who underwent EVT for acute ischemic stroke from the registry of three Korean hospitals. Patients with ICAS-related occlusion who were treated within 24 h of onset of the symptoms were included. We investigated immediate reperfusion performance, immediate safety outcomes, and 3-month clinical outcomes for the two first-line devices.

RESULTS

Of the 720 registered patients, 111 were eligible for this study. Forty-nine patients (44.1%) used SR and 62 (55.9%) used CA as the first-line device. Achieving successful reperfusion immediately after first-line thrombectomy was more frequent in the SR group than that in the CA group (77.6% vs. 43.5%, p = 0.001), with fewer additional rescue treatments (12.2% vs. 59.7%, p < 0.001). The incidence of iatrogenic dissection or rupture was lower in the SR group than that in the CA group (8.2% vs. 29.0%, p = 0.012). After additional rescue treatments, however, the final successful reperfusion rate did not differ between the two groups (SR 87.8% vs. CA 77.4%, p = 0.247), and there was no significant difference in the 3-month good outcomes (modified Rankin Scale, p = 0.524).

CONCLUSIONS

First-line SR thrombectomy showed higher immediate reperfusion and less vessel injury for ICAS-related occlusions than CA. However, there was no significant difference in the final reperfusion status or 3-month outcomes from additional rescue treatments.

Importance of lipid ratios for predicting intracranial atherosclerotic stenosis

BACKGROUND

This study aims to investigate the association of lipid ratios with intracranial atherosclerotic stenosis (ICAS) in a Chinese population.

METHODS

This cross-sectional study included 658 consecutive patients with ischemic stroke. Intracranial and extracranial arteries were evaluated for atherosclerotic stenosis using digital subtraction angiography or computed tomography angiography. Lipid ratios [total cholesterol (TC)/high-density lipoprotein-cholesterol (HDL-C), triglycerides (TG)/HDL-C, low-density lipoprotein-cholesterol (LDL-C)/HDL-C, non-high-density lipoprotein-cholesterol (non-HDL-C)/HDL-C, remnant cholesterol (RC)/HDL-C, apolipoprotein B (apo B)/apolipoprotein A-I (apo A-I), and apo B/HDL-C] were calculated.

RESULTS

The TC/HDL-C, LDL-C/HDL-C, RC/HDL-C, non-HDL-C/HDL-C, apo B/HDL-C and apo B/apo A-I ratios (all P < 0.05) were significantly associated with ICAS but not with extracranial atherosclerotic stenosis after adjustment for confounding factors. Receiver operating characteristic (ROC) curves analysis revealed that the apo B/apo A-I ratio had the largest area under the ROC curve (AUC) among lipid levels alone and for lipid ratios (AUC = 0.588). Lipid ratios had higher AUC values than those for lipid levels alone for the identification of ICAS.

CONCLUSION

The TC/HDL-C, LDL-C/HDL-C, RC/HDL-C, non-HDL-C/HDL-C apo B/HDL-C, and apo B/apo A-I ratios were significantly related to ICAS risk. Compared with the other variables tested, the apo B/apo A-I ratio appeared to be a better discriminator for identifying ICAS risk in stroke patients.

Intracranial Atherosclerotic Stenoses: Pathophysiology, Epidemiology, Risk Factors and Current Therapy Options

Intracranial atherosclerotic stenoses (ICAS) are one of the most common causes of first and recurrent cerebrovascular ischaemic events worldwide, with highest prevalence in Asian, Hispanic and African populations. Clinical trials have improved the understanding of epidemiology, risk factors and imaging characteristics of patients with ICAS. Current therapeutic approaches concerning these patients include management of risk factors, best medical therapy, potentially endovascular and rarely surgical therapy. In our review, we elucidate the current epidemiology and evidence in evaluation of risk factors and therapeutic options for providing favourable outcome for patients with ICAS.

Stenting with Acclino (flex) for symptomatic intracranial stenosis as secondary stroke prevention

BACKGROUND AND PURPOSE

Stroke recurrence is high in patients with symptomatic intracranial stenosis despite best medical treatment. Based on evidence from past studies using previous stent generations, elective intracranial stenting (eICS) is considered in a minority of patients. This study aims to report on experience performing eICS with a novel device combination.

METHODS

We retrospectively reviewed data from three high volume stroke centers and analyzed patients that were treated with eICS for symptomatic intracranial stenosis using the Acclino (flex) stent and the NeuroSpeed balloon catheter (Acandis GmbH, Pforzheim, Germany). Study endpoints were periprocedural rates of stroke regardless of territory or death at discharge and at the time of follow-up after eICS. Safety evaluation included asymptomatic and symptomatic intracranial hemorrhage, serious adverse events related to the intervention, and evaluation of stent patency at the time of follow-up.

RESULTS

The median age of patients that met the inclusion criteria (n=76) was 69 years. Target vessels were located in the anterior circulation in 55.3% (42/76) of patients. The periprocedural stroke rate was 6.5% (fatal stroke 2.6%; non-fatal stroke 3.9%) at discharge after eICS. Asymptomatic intracranial hemorrhage was observed in 5.2% (4/76) of patients. Follow-up DSA revealed in-stent restenosis of 25% (15/60), and percutaneous transluminal angioplasty was performed again in 11.6% (7/60) of patients.

CONCLUSION

Stenting for symptomatic intracranial stenosis with the Acclino (flex)/NeuroSpeed balloon catheter seemed to be safe and reinforces eICS as an endovascular therapy option for secondary stroke prevention. Future studies are warranted to confirm these findings and investigate antithrombotic strategies and in-stent restenosis to minimize periprocedural complications and guarantee long term stent patency.

Current Opinion on Endovascular Therapy for Emergent Large Vessel Occlusion Due to Underlying Intracranial Atherosclerotic Stenosis

For recanalization of emergent large vessel occlusions (ELVOs), endovascular therapy (EVT) using newer devices, such as a stent retriever and large-bore catheter, has shown better patient outcomes compared with intravenous recombinant tissue plasminogen activator only. Intracranial atherosclerotic stenosis (ICAS) is a major cause of acute ischemic stroke, the incidence of which is rising worldwide. Thus, it is not rare to encounter underlying ICAS during EVT procedures, particularly in Asian countries. ELVO due to underlying ICAS is often related to EVT procedure failure or complications, which can lead to poor functional recovery. However, information regarding EVT for this type of stroke is lacking because large clinical trials have been largely based on Western populations. In this review, we discuss the unique pathologic basis of ELVO with underlying ICAS, which may complicate EVT procedures. Moreover, we review EVT data for patients with ELVO due to underlying ICAS and suggest an optimal endovascular recanalization strategy based on the existing literature. Finally, we present future perspectives on this subject.

Design of stroke imaging package study of intracranial atherosclerosis: a multicenter, prospective, cohort study

Background

Intracranial atherosclerosis (ICAS) is a major cause of stroke worldwide. However, much remains unknown regarding its underlying pathophysiology. High-resolution magnetic resonance imaging (HR-MRI) can clearly display intracranial vessel wall lesions in vivo. The aim of stroke imaging package study of ICAS (SIPS-ICAS) study is to explore the stroke mechanisms of symptomatic ICAS, the dynamic changes under aggressive medical treatment and their associations with clinical events using conventional MRI sequences plus HR-MRI.

Methods

This is a multicenter, prospective, cohort study recruiting first-ever acute ischemic stroke patients attributed to intracranial large artery stenosis (>50% or occlusion). Subjects undergo a pre-designed stroke imaging packages at baseline and are recommended to receive aggressive medical treatments. Participants will be followed up for functional outcome, stroke recurrence, and death events at 3, 6 and 12 months and retake HR-MRI imaging at 6 months.

Results

Enrollment began in November 2018 and 96 patients have been enrolled as of September 2019.

Conclusions

The SIPS-ICAS study will provide insights into the pathophysiology of ICAS and identify specific imaging markers for risk stratification and prognosis prediction. At the same time, the feasibility and validity of the new stroke imaging package including HR-MRI will be assessed, which is promising for clinical routine use.

Intracranial Stenting: Is It Still an Option for Treatment of Patients With Intracranial Atherosclerosis?

Intracranial atherosclerotic disease (ICAD) is considered a major cause of recurrent cerebrovascular events. ICAD continues to be a disease without an effective method of reducing the risk of recurrent stroke and death, even with aggressive, highly monitored medical treatment. We reviewed data from three randomized controlled studies that published data comparing intracranial stenting vs. medical treatment for symptomatic severe-ICAD. Ethnic, demographic, clinical, and procedural differences were observed among the data from these trials that might influence their results. Future research should aim at establishing refined selection criteria that can identify high-risk ICAD patients who may benefit from intracranial stenting.

Association between time to treatment and functional outcomes according to the Diffusion-Weighted Imaging Alberta Stroke Program Early Computed Tomography Score in endovascular stroke therapy

BACKGROUND AND PURPOSE

The rate at which the chance of a good outcome of endovascular stroke therapy (EVT) decays with time when eligible patients are selected by baseline diffusion-weighted magnetic resonance imaging (DWI-MRI) and whether ischaemic core size affects this rate remain to be investigated.

METHODS

This study analyses a prospective multicentre registry of stroke patients treated with EVT based on pretreatment DWI-MRI that was categorized into three groups: small [Diffusion-Weighted Imaging Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS)] (8-10), moderate (5-7) and large (<5) cores. The main outcome was a good outcome at 90 days (modified Rankin Scale 0-2). The interaction between onset-to-groin puncture time (OTP) and DWI-ASPECTS categories regarding functional outcomes was investigated.

RESULTS

Ultimately, 985 patients (age 69 ± 11 years; male 55%) were analysed. Potential interaction effects between the DWI-ASPECTS categories and OTP on a good outcome at 90 days were observed (P_interaction  = 0.06). Every 60-min delay in OTP was associated with a 16% reduced likelihood of a good outcome at 90 days amongst patients with large cores, although no associations were observed amongst patients with small to moderate cores. Interestingly, the adjusted rates of a good outcome at 90 days steeply declined between 65 and 213 min of OTP and then remained smooth throughout 24 h of OTP (P_nonlinearity  = 0.15).

CONCLUSIONS

Our study showed that the probability of a good outcome after EVT nonlinearly decreased, with a steeper decline at earlier OTP than at later OTP. Discrepant effects of OTP on functional outcomes by baseline DWI-ASPECTS categories were observed. Thus, different strategies for EVT based on time and ischaemic core size are warranted.

Hemodynamics and stroke risk in intracranial atherosclerotic disease

OBJECTIVE

To investigate whether hemodynamic features of symptomatic intracranial atherosclerotic stenosis (sICAS) might correlate with the risk of stroke relapse, using a computational fluid dynamics (CFD) model.

METHODS

In a cohort study, we recruited patients with acute ischemic stroke attributed to 50 to 99% ICAS confirmed by computed tomographic angiography (CTA). With CTA-based CFD models, translesional pressure ratio (PR = pressure_poststenotic /pressure_prestenotic ) and translesional wall shear stress ratio (WSSR = WSS_{stenotic - throat} /WSS_prestenotic ) were obtained in each sICAS lesion. Translesional PR ≤ median was defined as low PR and WSSR ≥4th quartile as high WSSR. All patients received standard medical treatment. The primary outcome was recurrent ischemic stroke in the same territory (SIT) within 1 year.

RESULTS

Overall, 245 patients (median age = 61 years, 63.7% males) were analyzed. Median translesional PR was 0.94 (interquartile range [IQR] = 0.87-0.97); median translesional WSSR was 13.3 (IQR = 7.0-26.7). SIT occurred in 20 (8.2%) patients, mostly with multiple infarcts in the border zone and/or cortical regions. In multivariate Cox regression, low PR (adjusted hazard ratio [HR] = 3.16, p = 0.026) and high WSSR (adjusted HR = 3.05, p = 0.014) were independently associated with SIT. Patients with both low PR and high WSSR had significantly higher risk of SIT than those with normal PR and WSSR (risk = 17.5% vs 3.0%, adjusted HR = 7.52, p = 0.004).

INTERPRETATION

This work represents a step forward in utilizing computational flow simulation techniques in studying intracranial atherosclerotic disease. It reveals a hemodynamic pattern of sICAS that is more prone to stroke relapse, and supports hypoperfusion and artery-to-artery embolism as common mechanisms of ischemic stroke in such patients. Ann Neurol 2019;85:752-764.

Comparative Effectiveness of Aspirin and Clopidogrel Versus Aspirin in Acute Minor Stroke or Transient Ischemic Attack

Background and Purpose- This study aimed to compare the effectiveness of dual antiplatelet therapy with clopidogrel-aspirin to that of aspirin monotherapy in patients with acute minor cerebral ischemia using a prospective, nationwide, multicenter, stroke registry database in South Korea. Methods- CHANCE trial (Clopidogrel in High-Risk Patients With Acute Nondisabling Cerebrovascular Events)-like patients who met eligibility criteria modeled on the CHANCE trial eligibility criteria, including (1) acute minor ischemic stroke defined as National Institutes of Health Stroke Scale score ≤3 or lesion positive transient ischemic attack within 24 hours of onset and (2) noncardioembolic stroke mechanism. Propensity scores using the inverse probability of treatment weighting was used to adjust for baseline imbalances. The primary outcome was the composite of all stroke (ischemic and hemorrhagic), myocardial infarction, and vascular death by 3 months. Results- Among 5590 patients meeting the eligibility criteria, age was 64±13 year and 62.6% were male. Aspirin and combination of clopidogrel-aspirin were administered in 66.1% and 33.9% of patients, respectively. In unadjusted analysis, rates of the 3-month primary vascular event outcome were lower with clopidogrel-aspirin versus aspirin, 9.9% versus 12.2% (hazard ratio, 0.79 [0.67-0.95]). In propensity-weighted Cox proportional hazards regression with robust estimation, clopidogrel-aspirin was associated with a lower risk of the primary vascular event outcome (hazard ratio, 0.76 [0.63-0.92]) and all stroke events (hazard ratio, 0.74 [0.61-0.90]). Among 6 predefined subgroup analyses, 3 showed potential modification of treatment effect, with lesser benefit associated with the absence of prior antiplatelet use (Pinteraction=0.01) and younger age (<75 years, Pinteraction=0.07), and absence of benefit associated with small vessel occlusion subtype (Pinteraction=0.08). Conclusions- Dual antiplatelet therapy with aspirin and clopidogrel was associated with reduced stroke, myocardial infarction, and vascular death in the 3 months following a presenting minor, noncardioembolic ischemic stroke. Benefits may be particularly magnified in patients with a history of prior antiplatelet therapy, older age, and nonsmall vessel disease stroke mechanism.

Solitaire Thrombectomy for Acute Stroke Due to Intracranial Atherosclerosis-Related Occlusion: ROSE ASSIST Study

Background: Solitaire, a representative stent retriever, has shown high performance in removing embolic clots. However, its reperfusion potential in intracranial atherosclerotic stenosis (ICAS)-related occlusions has rarely been reported. In this ROSE ASSIST study, we hypothesized that Solitaire device is as effective and safe for removing in situ thrombi in ICAS-related occlusions as it is for removal of embolic occlusions.

Methods: Data from ASIAN KR, an observational multicenter registry (n = 720) enrolling patients who have undergone endovascular treatment for acute cervicocephalic artery occlusions, were retrospectively reviewed. Through blinded evaluations, occlusions were classified as ICAS-related (significant fixed focal stenosis observed at the occlusion site during endovascular treatment) or embolic (no or minimal stenosis observed). Among patients treated within 720 min after stroke onset, those who undertook Solitaire thrombectomy and whose underlying etiology was ICAS-related or embolic were included. The primary endpoint was immediate successful reperfusion (modified Treatment In Cerebral Ischemia 2b−3) after Solitaire stent retrieval. The safety endpoint included intracerebral hemorrhagic transformation and subarachnoid hemorrhage. Comparative analyses were performed between embolic and ICAS-related occlusions with 2:1 propensity score matching.

Results: In total, 303 patients (embolic, 228; ICAS-related, 75) were included in the analyses. As for the primary endpoint, the immediate successful reperfusion rate following Solitaire thrombectomy did not differ between the two etiologic groups after propensity score matching (73.1% embolic vs. 65.8% ICAS-related, p = 0.261). The final successful reperfusion grade was also similar in the two groups (79.3 vs. 72.0%, p = 0.219). The grades and frequencies of intracerebral hemorrhagic transformation and subarachnoid hemorrhage did not differ between groups (p = 0.134 and p = 0.269, respectively).

Conclusions: The immediate reperfusion performance in terms of thrombus removal of Solitaire thrombectomy for ICAS-related occlusions was similar to that for embolic occlusions.

Current state of acute stroke care in Southeast Asian countries

Acute stroke care systems in Southeast Asian countries are at various stages of development, with disparate treatment availability and practice in terms of intravenous thrombolysis and endovascular therapy. With the advent of successful endovascular therapy stroke trials over the past decade, the pressure to revise and advance acute stroke management has greatly intensified. Southeast Asian patients exhibit unique stroke features, such as increased susceptibility to intracranial atherosclerosis and higher prevalence of intracranial haemorrhage, likely secondary to modified vascular risk factors from differing dietary and lifestyle habits. Accordingly, the practice of acute endovascular stroke interventions needs to take into account these considerations. Acute stroke care systems in Southeast Asia also face a unique challenge of huge stroke burden against a background of ageing population, differing political landscape and healthcare systems in these countries. Building on existing published data, further complemented by multi-national interaction and collaboration over the past few years, the current state of acute stroke care systems with existing endovascular therapy services in Southeast Asian countries are consolidated and analysed in this review. The challenges facing acute stroke care strategies in this region are discussed.

Feasibility of Permanent Stenting with Solitaire FR as a Rescue Treatment for the Reperfusion of Acute Intracranial Artery Occlusion

BACKGROUND AND PURPOSE

The Solitaire FR can be used not only as a tool for mechanical thrombectomy but also as a detachable permanent stent. Our aim was to assess the feasibility and safety of permanent stent placement with the Solitaire FR compared with other self-expanding stents for intracranial artery recanalization for acute ischemic stroke.

MATERIALS AND METHODS

From January 2011 through January 2016, we retrospectively selected 2979 patients with acute ischemic stroke. Among them, 27 patients who underwent permanent stent placement (13 patients with the Solitaire FR [Solitaire group] and 14 patients with other self-expanding stents [other stent group]) were enrolled. The postprocedural modified TICI grade and angiographic and clinical outcomes were assessed. The safety and efficacy of permanent stent placement of the Solitaire FR for acute large-artery occlusion were evaluated.

RESULTS

Stent placement was successful in all cases. Modified TICI 2b-3 reperfusion was noted in 84.6% of the Solitaire group and in 78.6% of the other stent group. Procedural time was significantly shorter in the Solitaire group than in the other stent group (P = .022). Shorter procedural time was correlated with favorable outcome (ρ = 0.46, P = .035). No significant differences were found in the modified TICI grade, NIHSS score, mRS, and hemorrhagic transformation rate between the 2 groups. The acute in-stent thrombosis rate at discharge was significantly lower when a glycoprotein IIb/IIIa inhibitor was injected during the procedure (P = .013).

CONCLUSIONS

Permanent stent placement with the Solitaire FR compared with other self-expanding stents appears to be feasible and safe as a rescue tool for refractory intra-arterial therapy.

Low-Dose Tirofiban Improves Functional Outcome in Acute Ischemic Stroke Patients Treated With Endovascular Thrombectomy

BACKGROUND AND PURPOSE

Chinese patients largely experience acute ischemic stroke (AIS) because of large artery atherosclerosis rather than cardioembolism, and whether tirofiban is safe and effective in these patients treated with endovascular thrombectomy (ET) is unknown. This study evaluated the safety and efficacy of tirofiban in Chinese patients with AIS treated with ET.

METHODS

This observational study is based on a single-center prospective registry study. Patients with AIS undergoing ET with second-generation stent retrievers from January 2013 to February 2017 were treated with ET alone or ET plus low dose of tirofiban. The primary outcome was symptomatic intracerebral hemorrhage (sICH). The secondary outcomes included rate of early reocclusion, any ICH, fatal ICH, and 3-month and long-term functional outcomes.

RESULTS

One hundred eighty AIS subjects were included in the analysis, including 90 subjects treated with tirofiban and 90 subjects without tirofiban. Sixty-three subjects (35%) had any ICH, 19 of them (11%) were sICH, and 9 of them (5%) were fatal ICH. Ten subjects (11%) treated with tirofiban experienced sICH and 9 subjects (10%) not given tirofiban experienced sICH, not a significant difference (P=0.808). Early reocclusion happened in 4 of 90 subjects (4.4%) treated with tirofiban and 8 of 90 subjects (8.9%) not treated with tirofiban (P=0.370). One hundred sixty-one subjects (89%) completed long-term follow-up, subjects treated tirofiban were associated with lower odds of death (23% versus 44%, P=0.005) when compared with those who were not treated. Additionally, tirofiban was associated with better odds of long-term functional independence (adjusted odds ratio, 4.37; 95% confidence interval, 1.13-16.97; P=0.033).

CONCLUSIONS

In patients with AIS undergoing ET, tirofiban is not associated with higher sICH, it seems to lead to lower odds of deaths and better odds of long-term functional independence. Further investigations are needed to determine the efficacy of tirofiban in preventing early reocclusion, the underlying mechanisms, and its optimal treatment protocol.

Medical Treatment of Intracranial Atherosclerosis: An Update

For patients with symptomatic intracranial atherosclerosis (ICAS), antithrombotic agents are the mainstay of therapy. Anticoagulation (warfarin) is not widely used since it is not more effective than aspirin and carries a high risk of bleeding. New oral anticoagulants are showing promise, but their use has not been investigated in appropriate clinical trials. Since the recurrent stroke risk is high with aspirin monotherapy, dual antiplatelets are considered in the early stage of symptomatic ICAS. Based on the Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events (CHANCE) and Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) results, aspirin plus clopidogrel has been recommended. However, this combination was not superior to aspirin monotherapy in patients with ICAS in the CHANCE substudy. Progression of ICAS is common, and it is associated with recurrent strokes. In the Trial of Cilostazol in Symptomatic Intracranial Arterial Stenosis (TOSS) study, aspirin plus cilostazol was more effective than aspirin monotherapy in preventing progression. The TOSS II trial showed that the overall change in stenosis was better with aspirin plus cilostazol than with aspirin plus clopidogrel. Aside from antithrombotic therapy, risk factor management is critical for secondary prevention, and high blood pressure is clearly linked to recurrent stroke. However, blood pressure may have to be cautiously managed in the early stage of stroke. Considering that ICAS is the major cause of stroke worldwide, further investigations are needed to establish optimal management strategies for patients with ICAS.

Intracranial Atherosclerosis: From Microscopy to High-Resolution Magnetic Resonance Imaging

Intracranial atherosclerosis is one of the leading causes of ischemic stroke and occurs more commonly in patients of Asian, African or Hispanic origin than in Caucasians. Although the histopathology of intracranial atherosclerotic disease resembles extracranial atherosclerosis, there are some notable differences in the onset and severity of atherosclerosis. Current understanding of intracranial atherosclerotic disease has been advanced by the high-resolution magnetic resonance imaging (HRMRI), a novel emerging imaging technique that can directly visualize the vessel wall pathology. However, the pathological validation of HRMRI signal characteristics remains a key step to depict the plaque components and vulnerability in intracranial atherosclerotic lesions. The purpose of this review is to describe the histological features of intracranial atherosclerosis and to state current evidences regarding the validation of MR vessel wall imaging with histopathology.