Prospective study of symptomatic atherothrombotic intracranial stenoses: The GESICA Study

Comparison of the safety and efficacy of Neuroform Atlas stent deployed via Gateway balloon catheter and microcatheter for the treatment of intracranial stenosis

OBJECTIVE

This study aimed to compare the safety and efficacy of the Atlas stent released by the Gateway catheter and microcatheter in the treatment of intracranial stenosis (IS).

METHODS

The primary efficacy and safety outcomes were the in-stent restenosis (ISR) rate and post-procedural stroke or death within one month.

RESULTS

Atlas stents were deployed using the Gateway catheter and microcatheter in 19 (57.6 %) and 14 (42.4 %) procedures, respectively. Follow-up imaging data were available for 26 patients; the incidence of ISR was 15.4 %, and the ISR rate was higher, though not significantly, in the microcatheter group than in the Gateway group (30.0% vs. 6.25 %, P = .39). Clinical follow-up data were available for 30 patients; the post-procedural stroke rate was 3.3 % within one month and 13.3 % from one month to one year. The post-procedural stroke rate within one month was higher, though not significantly, in the microcatheter group than in the Gateway group (7.7% vs. 0 %, P = .43). The Gateway group had a significantly lower rate of post-procedural stroke in the same territory than that of the microcatheter group (0% vs. 30.8 %, P = .026). A higher incidence of residual stenosis <30 % was found in the non-ISR group than in the ISR group (72.2% vs. 0 %, P = .014).

CONCLUSIONS

This study provides preliminary evidence that the Atlas stent is safe and effective for IS treatment. The use of the Gateway catheter to deliver the Atlas stent appears to be safer than using microcatheter. The incidence of ISR may be related to the degree of the residual stenosis.

Balloon-mounting stent versus balloon angioplasty for intracranial arterial stenosis: A systematic review and meta-analysis

BACKGROUND

Intracranial artery atherosclerotic stenosis (ICAS) is a major cause of stroke, especially in Asian countries. Current treatment options, including balloon-mounted stent (BMS) and balloon angioplasty (BA), lack sufficient evidence to determine a preferred approach. This systematic review and meta-analysis aimed to compare the efficacy and safety of BMS and BA in treating ICAS.

METHODS

Following PRISMA 2020 guidelines, we conducted a comprehensive search in PubMed, Web of Science, and Scopus up to December 1, 2023. Eligible studies compared BMS with BA in patients diagnosed with ICAS. Primary outcomes included the success rate and occurrence of stroke (ischemic or hemorrhagic). Secondary outcomes were perforator occlusion, in-stent thrombosis, death, and restenosis. Statistical analysis was conducted using R software version 4.3.1, employing a random-effects model.

RESULTS

Five high-quality studies involving 707 patients (515 males, 192 females) were included. BMS had a significantly higher success rate compared to BA (Risk Ratio [RR]: 1.13; CI: 1.03 to 1.24, p < 0.01; I2 = 14 %). The overall risk for stroke (ischemic and hemorrhagic) was significantly higher in BMS (RR: 2.97; CI: 1.32 to 6.67, p < 0.01; I2 = 0 %). However, no significant difference was found between BMS and BA regarding ischemic stroke (RR: 2.33; CI: 0.80 to 6.74, p = 0.12; I2 = 0 %). Additionally, no significant differences were observed in terms of perforator occlusion, in-stent thrombosis, dissection, minor and major strokes, and mortality rates. BMS was associated with a lower risk of restenosis (RR: 0.31; 95 % CI: 0.12 to 0.83, p = 0.02; I2 = 0 %).

CONCLUSION

Our results indicate that BMS might be associated with higher success and lower restenosis rates than BA in the treatment of ICAS but with an increased overall risk of stroke. No significant differences were observed in ischemic stroke, perforator occlusion, in-stent thrombosis, dissection, minor and major strokes, and mortality rates. The choice of treatment should consider these findings, alongside the technical challenges and desired angiographic outcomes. Future randomized controlled trials are necessary to further elucidate these results.

Association of plaque characteristics with long-term stroke recurrence in patients with intracranial atherosclerotic disease: a 3D high-resolution MRI-based cohort study

OBJECTIVES

To evaluate the predictive ability of plaque characteristics for long-term stroke recurrence among patients with symptomatic intracranial atherosclerotic disease (ICAD).

METHODS

This cohort study included 132 patients with acute ischemic stroke (AIS) attributed to ICAD who were recruited between July 2017 and December 2020 and followed until stroke recurrence or December 2021. Plaque surface irregularity, degree of stenosis, plaque burden, remodeling ratio, enhancement ratio, and intraplaque hemorrhage were assessed with 3-dimensional high-resolution magnetic resonance vessel wall imaging (3D HR-MRI). Data were analyzed using Cox models, receiver operating characteristic (ROC) curves, and Kaplan-Meier survival analysis.

RESULTS

Of the 132 patients, during a median follow-up of 2.8 years, stroke recurrence occurred in 35 patients. The multivariable-adjusted hazard ratio (95% confidence interval) of stroke recurrence was 3.15 (1.34-7.42) per 10% increase in plaque burden and 2.17 (1.27-3.70) for enhancement ratio. The area under the curve (AUC) to predict stroke recurrence was 0.725 (95% CI 0.629-0.822) for plaque burden, 0.692 (95% CI 0.593-0.792) for enhancement ratio, and only 0.595 (95% CI 0.492-0.699) for the Essen stroke risk score. The Kaplan-Meier survival analysis further demonstrated significant differences in survival of free recurrent stroke between patients with plaque burden or enhancement ratio below and above the optimum cut-offs (both p < 0.001).

CONCLUSION

Higher plaque burden and enhancement ratio are independent risk factors for long-term stroke recurrence among patients with symptomatic ICAD, and valuable imaging markers for predicting and stratifying risk of stroke recurrence.

CLINICAL RELEVANCE STATEMENT

In patients with symptomatic ICAD, the results of this high-resolution magnetic resonance vessel wall imaging study have potential implications for optimal management of intracranial plaques and secondary prevention of stroke recurrence based on plaque burden and enhancement ratio.

KEY POINTS

• Identification of intracranial plaque characteristics responsible for stroke recurrence is essential to preventing stroke recurrence in patients with symptomatic intracranial atherosclerotic disease. • Higher plaque burden and enhancement ratio are independent risk factors for stroke recurrence. • Plaque burden and enhancement ratio are valuable imaging markers in the prediction and stratification of the risk of stroke recurrence.

Intracranial atherosclerosis update for neurointerventionalists

The management of intracranial atherosclerotic disease (ICAD) has been evolving with advanced imaging, refinements of best medical treatment, and the development of endovascular options. There has been a significant increase in the use of endovascular therapy for symptomatic ICAD in the USA over the past 6 years. The rationale for this review is to update neurointerventionalists in these areas so that evidence-based decisions can be considered when counseling potential patients regarding their risks, benefits, and potential complications. The landmark SAMMPRIS trial demonstrated superiority of aggressive medical management (AMM) over intracranial stenting as an initial treatment. However, the risk of disabling or fatal stroke remains high in patients presenting with stroke treated with AMM. Recent studies showed a significantly lower rate of periprocedural complications from intracranial stenting. Patients who have failed medical treatment may therefore benefit from intracranial stenting, particularly in those with hemodynamic compromise and large vessel embolic stroke. Drug coated angioplasty balloons and drug eluting stents may potentially reduce the risk of in-stent re-stenosis. Large vessel occlusion (LVO) due to underlying ICAD is seen in a subset of thrombectomy-eligible patients. The use of stenting as a rescue therapy in LVO thrombectomy has also shown promising early results.

Remote ischemic conditioning after stroke: Research progress in clinical study

BACKGROUND AND PURPOSE

Stroke is a leading cause of global morbidity and mortality, indicating the necessity and urgency of effective prevention and treatment. Remote ischemic conditioning (RIC) is a convenient, simple, non-intrusive, and effective method that can be easily added to the treatment regime of stroke patients. Animal experiments and clinical trials have proved the neuroprotective effects of RIC on brain injury including (examples of neuroprotective effects). This neuroprotection is achieved by raising brain tolerance to ischemia, increasing local cerebral blood perfusion, promoting collateral circulations, neural regeneration, and reducing the incidence of hematomas in brain tissue. This current paper will summarize the studies within the last 2 years for the comprehensive understanding of the use of RIC in the treatment of stroke.

METHODS

This paper summarizes the clinical research progress of RIC on stroke (ischemic stroke and hemorrhagic stroke (HS)). This paper is a systematic review of research published on registered clinical trials using RIC in stroke from inception through November 2022. Four major databases (PUBMED, WEB OF SCIENCE, EMBASE, and ClinicalTrials.gov) were searched.

RESULTS

Forty-eight studies were identified meeting our criteria. Of these studies, 14 were in patients with acute ischemic stroke with onset times ranging from 6 h to 14 days, seven were in patients with intravenous thrombolysis or endovascular thrombectomy, 10 were in patients with intracranial atherosclerotic stenosis, six on patients with vascular cognitive impairment, three on patients with moyamoya disease, and eight on patients with HS. Of the 48 studies, 42 were completed and six are ongoing.

CONCLUSIONS

RIC is safe, feasible, and effective in the treatment of stroke. Large-scale research is still required to explore the optimal treatment options and mechanisms of RIC in the future to develop a breakthrough in stroke prevention and treatment.

STENOSIS: Long-term single versus dual antiplatelet therapy in patients with ischaemic stroke due to intracranial atherosclerotic disease - a randomised trial

Rationale

Intracranial atherosclerotic disease (ICAD) is a pathological process that causes progressive stenosis and cerebral hypoperfusion, leading to stroke occurrence and recurrence around the world. The exact duration of dual antiplatelet therapy (DAPT) for ICAD is unclear in view of long-term risk of bleeding complications.

Aim

The current study aims to study the efficacy and safety of long-term DAPT (up to 12 months) in patients with ICAD.

Sample size

Using 80% power and an alpha error of 5 %, presuming a 10%-15% drop-out rate, a total of 2200 patients will be recruited for the study.

Methodology

This is a prospective, randomised, double-blind, placebo controlled trial.

Study outcomes

The primary outcomes include recurrent ischaemic stroke (IS) or transient ischaemic attack and any intracranial haemorrhage (ICH), major or minor systemic bleeding at the end of 12 months. Secondary outcomes include composite of any stroke, myocardial infarction or death at the end of 12 months. The safety outcomes include any ICH, major or minor bleeding as defined using GUSTO (Global Use of Streptokinase and tPA for occluded Coronary Arteries) classification at the end of 12 months and 1 month after completion of the drug treatment phase.

Discussion

The study will provide level I evidence on the duration of DAPT among patients with IS due to ICAD of more than or equal to 50%.

A bibliometric analysis of the 100 most-cited clinical articles in the research of intracranial artery stenosis and intracranial atherosclerosis

Background

Intracranial arterial stenosis (ICAS), caused by intracranial atherosclerosis, is one of the major causes of ischemic stroke. This study identified the top 100 most-cited publications on ICAS through a bibliometric analysis.

Methods

Two independent authors conducted a search in the Web of Science database for clinical articles on ICAS published between 1993 and 2022. The top 100 most-cited articles were then extracted. For each article, the analysis covered the title, author, country of origin/affiliation, journal, total number of citations, number of citations per year, and type of study.

Results

The top 100 most-cited papers in the ICAS were authored by 565 authors from 12 countries and published in 29 journals. In terms of the 5-year trend, the largest number of papers were published between 2003 and 2007 (n = 31). The median number of citations for the 100 papers was 161 (range 109-1,115). The journal with the highest proportion of the 100 most published articles was Stroke, accounting for 41% of articles and 37% of the citations. According to country of origin, the United States of America accounted for the largest number of articles, followed by China, Japan, and South Korea, with these four countries together accounting for 81% of the total number of articles and 88% of the citations. Trends in the past five years included the use of terms such as acute ischemic stroke and mechanical thrombectomy.

Conclusion

The findings of this study provide novel insight into this field and will facilitate future research endeavors.

Detection of moderate to severe middle cerebral artery atherosclerotic stenosis in stroke patients: Transcranial color-coded duplex sonography versus computed tomography angiography

Background

Intracranial atherosclerotic stenosis is a common cause of ischemic cerebrovascular events and is associated with a high risk of stroke recurrence. This study aimed to assess the diagnostic accuracy of transcranial color-coded duplex sonography for moderate-to-severe middle cerebral artery stenosis in stroke patients.

Methods

A retrospective analysis was carried out, including 31 patients aged ⩾18 years hospitalized for ischemic cerebrovascular event in whom middle cerebral artery stenosis ⩾30% was identified on computed tomography angiography. Transcranial color-coded duplex sonography findings were compared to the degree of stenosis blindly identified on the computed tomography angiography used as the reference method.

Results

Overall, 27 patients had M1 stenosis and the other 4 had M2 stenosis. To detect M2 stenosis ⩾ 50% and ⩾ 70%, stenotic to pre-stenotic ratio ⩾ 2 and ⩾ 3 had a sensitivity of 100%, respectively. To detect M1 stenosis ⩾ 70%, peak systolic velocity ⩾ 300 cm/s had a sensitivity of 53.8% and specificity of 85.7% with area under the receiver-operating characteristic curve of 0.753 (95% confidence interval: 0.568-0.938; p = 0.026), and stenotic to pre-stenotic ratio ⩾ 3 had a sensitivity of 84.6% and a specificity of 78.6% (area under the curve = 0.854; 95% confidence interval: 0.707-1; p = 0.002). Middle cerebral artery/anterior cerebral artery velocity ratio < 0.7 had a sensitivity of 57.1% and specificity of 90% to detect dampened pre-stenotic flow in middle cerebral artery secondary to downstream M1 stenosis ⩾ 70% (area under the curve = 0.800; 95% confidence interval: 0.584-1; p = 0.040).

Conclusion

This study showed that stenotic to pre-stenotic ratio ⩾ 3 was more sensitive than peak systolic velocity ⩾ 300 cm/s to screen M1 stenosis ⩾ 70%. Middle cerebral artery/anterior cerebral artery ratio < 0.7 was a good indirect sign to detect dampened pre-stenotic flow due to M1 stenosis ⩾ 70%.

Association of culprit plaque enhancement ratio, hypoperfusion and HbA1c with recurrent ischemic stroke in patients with atherosclerotic stenosis of the middle cerebral artery

PURPOSE

To investigate the differences in intracranial culprit plaque characteristics of the middle cerebral artery (MCA), collateral circulation and hypoperfusion in patients with and without recurrent ischemic stroke and to identify the association with the recurrent ischemic cerebrovascular events.

METHOD

Eighty-six patients with acute/subacute ischemic stroke caused by atherosclerotic plaques of the MCA were retrospectively enrolled and grouped into patients with recurrence (n = 36) and without recurrence (n = 50). All patients underwent high-resolution vessel wall imaging and dynamic susceptibility contrast-enhanced perfusion weighted imaging. The differences in culprit plaque characteristics, collateral circulation and hypoperfusion in the territory of the stenotic MCA were assessed between the two groups. The relationship between plaque characteristics and hypoperfusion was evaluated. The independent factors of recurrent ischemic stroke were identified by logistic regression analyses.

RESULTS

Higher HbA1c, culprit plaque enhancement grade, culprit plaque enhancement ratio, and lower time to peak map based on the Alberta Stroke Program Early CT score (TTP-ASPECTS) were observed in the recurrence group(all p < 0.050). Both plaque enhancement grade and enhancement ratio were significantly associated with TTP-ASPECTS (p = 0.030 and 0.039, respectively). HbA1c, culprit plaque enhancement ratio and TTP-ASPECTS were independent factors of the recurrence of ischemic stroke (all p < 0.050). The area under the curve of the combination including the above factors (AUC = 0.819) was significantly higher than that of any variable alone after adjustment (all p < 0.050).

CONCLUSIONS

Culprit plaque enhancement ratio, TTP-ASPECTS and HbA1c were independent factors of recurrent ischemic stroke. Their combination improved the accuracy in identifying the risk of recurrent ischemic stroke.

Role of Advanced Hemodynamic Ultrasound Evaluation in the Differential Diagnosis of Middle Cerebral Artery Stenosis: Introducing Morphological Criteria

OBJECTIVE

The aim of the work described here was to determine the possible impact of the new technique advanced hemodynamic ultrasound evaluation (AHUSE) in identification of severe intracranial stenosis. Transcranial Doppler (TCD) and transcranial color-coded Doppler (TCCD) provide reliable velocimetric data, the indirect analysis of which allows us to obtain information on the patency of vessels and assumed stenosis range. However, very tight stenoses (>95%) cannot be detected with velocimetric criteria because of spectrum drops and the absence of high velocities, so that the right curve of the Spencer equation cannot be solved. Likewise, high velocities are not detected when analyzing morphologically long stenosis. Furthermore, the current classifications based on velocimetric criteria do not provide any categorization on stenoses with multiple acceleration points (MAPs).

METHODS

With this Technical Note we aim to introduce, in addition to velocimetric criteria, more morphological criteria based on TCCD with the algorithm of AHUSE to optimize the characterization of intracranial stenosis (IS). TCCD-AHUSE relies on intensity-based next-generation techniques and can be used to identify IS with MAPs and simultaneously perform a morphological assessment of the stenosis length.

RESULTS

We introduce a new technical ultrasound (U) approach that we tested in a sample of four different types of stenoses combining velocimetric data and AHUSE using Esaote Microvascularization (MicroV) technique to the M1 tract of the middle cerebral artery (MCA).

CONCLUSION

The authors believe that a multiparametric evaluation is more sensitive and supports the clinician by introducing the morphological concept, not just the velocimetric concept, to differentiate the IS pattern of MCA. The potential for developing a diagnostic/prognostic algorithm is discussed.

Use of the neuroform atlas for stenting of intracranial atherosclerotic disease: Clinical and angiographic outcomes

BACKGROUND

Intracranial atherosclerotic disease (ICAD) is a potential cause of ischemic stroke. Treatment of ICAD can include intracranial stenting. There are specifically designed stents for this use-case; however, less is known about the off-label use of the Neuroform Atlas stent. In this study, we describe the outcomes of the Neuroform Atlas stent for treatment of ICAD.

METHODS

Adult patients with symptomatic ICAD failing best medical treatment undergoing elective intracranial stenting using the Neuroform Atlas stent between November 2018 and March 2021 were included. Patient demographics, procedure-related details and clinical and imaging outcomes were analyzed.

RESULTS

Eighteen patients met the inclusion criteria, with a mean follow-up duration of 9.6 ± 6.8 (standard deviation) months. There were two procedure-related mortalities (one massive intracranial hemorrhage and one groin site complication with sepsis). Fifteen patients were alive at the 6-month follow-up, all with satisfactory stent patency on follow-up imaging without any new ischemic events. Modified Rankin Scale at latest follow-up was 1.9 (interquartile range 5).

CONCLUSION

In this single-center consecutive series, intracranial stenting with the Neuroform Atlas stent was a safe and effective treatment for symptomatic ICAD patients failing best medical management.

Morphology of middle cerebral artery using computed tomography angiographic study in a tertiary care hospital

Increased tortuosity of vessel is associated with high incidence of plaque formation leading to atherosclerosis. Surgical procedures are done after analyzing morphology of middle cerebral artery (MCA). However, literature describing MCA morphology using computed tomography angiography (CTA) is limited, so this study was planned to determine its incidence in Indian population. Datasets of CTA from 289 patients (180 males and 109 females), average age: 49.29±16.16 years (range: 11 to 85 years), from a tertiary care hospital were systematically reviewed for morphology of MCA. Cases involving aneurysms and infarcts were excluded. Four shapes of MCA were recognized: straight, U, inverted U, and S-shaped. MCA was straight in 44% (254/578), U-shaped in 37% (215/578), S shaped in 15% (89/578) and inverted U-shaped in 3% (20/578) cases. In males, MCA was straight in 46% (166/360), U-shaped in 37% (134/360), S-shaped in 16% (58/360) and inverted U-shaped in 4% (14/360) cases. In females, MCA was straight in 42% cases (92/218), U-shaped in 37% (81/218), S-shaped in 17% (36/218) and inverted U-shaped in 4% (9/218). On comparing shape with various age groups using chi square test, U shaped (P≤0.001) and S-shaped (P=0.003) MCA were found to be statistically significant. The incidence of straight shape was higher in advanced age group (>60 years). Knowledge of MCA shape will be useful for clinicians and surgeons in successful endovascular recanalization. Also, this data would help surgeons during neurointerventional procedures.

Extracranial-Intracranial Cerebral Revascularization for Atherosclerotic Vessel Occlusion: An Updated Systematic Review of the Literature

BACKGROUND

Atherosclerotic steno-occlusive cerebrovascular disease includes extracranial carotid occlusive and intracranial atherosclerotic disease. Despite the negative findings in Carotid Occlusion Surgery Study (COSS), many large centers continue to report favorable results for revascularization surgery in select groups of patients. The aim of our study was to perform an updated systematic review to investigate the role of revascularization surgery for atherosclerotic steno-occlusive patients in the modern era.

METHODS

Five independent reviewers performed Preferred Reporting Items for Systematic Reviews and Meta-Analyses-guided literature searches in October 2022 to identify articles reporting clinical outcomes in adult patients undergoing bypass for atherosclerotic steno-occlusive disease. Primary endpoints used were perioperative and long-term ischemic strokes, intracerebral hemorrhage, bypass patency, and favorable clinical outcomes. Study quality was evaluated with Newcastle-Ottawa, JADAD, and the Oxford Center for Evidence-Based Medicine scales.

RESULTS

A total of 6709 articles were identified in the initial search. Of these articles, 50 met the inclusion criteria and were included in the systematic review. A notable increase in the proportion of articles published over the past 10 years was observed. There were 6046 total patients with 4447 bypasses performed over the period from 1978 to 2022. The average length of follow-up was 2.75 ± 2.71 years. The average Newcastle-Ottawa was 6.23 out of 9 stars. There was a significant difference in perioperative stroke (odds ratio [OR], 0.65 [0.48-0.87]; P = 0.004), long-term ischemia (OR, 0.32 [0.23-0.44]; P < 0.0001), overall ischemia (OR, 0.36 [0.28-0.44]; P < 0.0001), and favorable outcomes (OR, 3.63 [2.84-4.64]; P < 0.0001) when comparing pre-COSS to post-COSS time frames in favor of post-COSS.

CONCLUSIONS

Based on a systematic review of 50 articles, the existing literature indicates that long-term stroke rates and favorable outcomes for surgical revascularization for steno-occlusive disease have improved over time and are lower than previously reported. Improved patient selection, perioperative care, and surgical techniques may contribute to improved outcomes.

High-Resolution Vessel Wall MRI in Assessing Postoperative Restenosis of Intracranial Atherosclerotic Disease Before Drug-Coated Balloon Treatment: An Outcome Prediction Study

BACKGROUND

Postoperative restenosis frequently occurs in intracranial atherosclerotic disease (ICAD) patients after drug-coated balloon (DCB) treatment. However, high-risk plaques associated with postoperative restenosis remain to be explored.

PURPOSE

To assess whether high-resolution vessel wall MRI (HR-VWI) contributes to the identification of high-risk plaques associated with postoperative restenosis before DCB treatment.

STUDY TYPE

Retrospective.

SUBJECTS

A total of 70 patients with ICAD who underwent DCB treatment.

FIELD STRENGTH/SEQUENCE

3.0 T; magnetic resonance angiography, HR-VWI.

ASSESSMENT

All patients underwent HR-VWI examination prior to DCB treatment. Digital subtraction angiography (DSA) measurement was assessed 6 months (±1 month) after operation to determine the vessel restenosis, classifying patients into three groups of no stenosis, mild stenosis (<50%), and restenosis (>50%). Clinical factors and HR-VWI characteristics, including vessel and lumen area at maximal lumen narrowing (MLN), plaque area and length, degree of stenosis, plaque burden, remodeling index, and enhancement amplitude, were compared among three groups. Clinical factors and HR-VWI characteristics were separately evaluated for the association with postoperative restenosis.

STATISTICAL TESTS

Kolmogorov-Smirnov test, intra-class correlation coefficient, Kruskal Wallis H test, Mann-Whitney U test, receiver operating characteristic (ROC) curve, multivariable linear regression analysis. P-values <0.05 was considered statistically significant.

RESULTS

During the follow-up DSA measurement, 13 lesions (18.5%) showed restenosis. With HR-VWI, significant differences among three groups were observed in plaque length, lumen area of MLN, degree of stenosis, enhancement amplitude, and plaque burden. In ROC analysis, plaque length (area under the curve [AUC] = 0.809), and enhancement amplitude (AUC = 0.880) provided higher efficacy in identification of high-risk plaques associated with postoperative restenosis than degree of stenosis (AUC = 0.746) and plaque burden (AUC = 0.759). Multivariable linear regression analysis showed that plaque length and enhancement amplitude were independent prognostic factors of postoperative restenosis.

DATA CONCLUSION

HR-VWI has the potential to identify high-risk plaques in ICAD patients before DCB treatment.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY: Stage 2.

Verifynow P2Y12 PRU-Guided Modification of Clopidogrel for Prevention of Recurrent Ischemic Stroke: A Real-World Prospective Cohort Study

INTRODUCTION

Clopidogrel resistance causes recurrent stroke. However, outcomes of modified antiplatelet medications to prevent recurrent ischemic stroke are not well known.

METHODS

Patients who received clopidogrel with and without modification as initial treatment for stroke were recruited and compared. The primary outcome was ischemic stroke and myocardial infarction at the 1-year follow-up. The secondary outcome was bleeding complications.

RESULTS

Overall, 206 patients treated with clopidogrel were enrolled and were divided into the modification (n = 39) and no modification (n = 167) groups. There was a significant difference in the incidence of severe cerebral arterial stenosis between the two groups (modification group, 16/39, 41.03%; no modification group, 36/167, 21.56%, P = 0.012) at baseline. The loss to follow-up rate was 12.14% (25/206). After adjustment for severe cerebral artery stenosis, antiplatelet modification based on the platelet reactivity unit (PRU) value significantly improved in the per protocol set (odds ratio 0.142, 95% confidential interval 0.022-0.898, P = 0.038). The area under the curve of the different PRU cutoff values were 0.630, 0.605, and 0.591 (P = 0.016, 0.051, and 0.092) for PRU 190, 208, and 235, respectively.

CONCLUSION

Verifynow P2Y₁₂ PRU-guided modification of clopidogrel for ischemic stroke significantly improved or prevented recurrence at the 1-year follow-up. Our findings suggest that clopidogrel therapy based on the PRU cutoff value of 190 should be considered to improve outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02618265 (December 1, 2015).

Collateral Flow in Magnetic Resonance Angiography: Prognostic Value for Vertebrobasilar Stenosis With Stroke Recurrence

Background and Purpose

Intracranial vertebrobasilar atherosclerotic stenosis (IVBAS) is a major cause of posterior circulation stroke. Some patients suffer from stroke recurrence despite receiving medical treatment. This study aimed to determine the prognostic value of a new score for the posterior communicating artery and the P1 segment of the posterior cerebral artery (PCoA-P1) for predicting stroke recurrence in IVBAS.

Methods

We retrospectively enrolled patients with severe IVBAS (70%–99%). According to the number of stroke recurrences, patients were divided into no-recurrence, single-recurrence, and multiple-recurrences groups. We developed a new 5-point grading scale, with the PCoA-P1 score ranging from 0 to 4 based on magnetic resonance angiography, in which primary collaterals were dichotomized into good (2–4 points) and poor (0 or 1 point). Stroke recurrences after the index stroke were recorded. Patients who did not experience stroke recurrence were compared with those who experienced single or multiple stroke recurrences.

Results

From January 2012 to December 2019, 176 patients were enrolled, of which 116 (65.9%) had no stroke recurrence, 35 (19.9%) had a single stroke recurrence, and 25 (14.2%) had multiple stroke recurrences. Patients with single stroke recurrence (odds ratio [OR]=4.134, 95% confidence interval [CI]=1.822–9.380, p=0.001) and multiple stroke recurrences (OR=6.894, 95% CI=2.489–19.092, p<0.001) were more likely to have poor primary collaterals than those with no stroke recurrence.

Conclusions

The new PCoA-P1 score appears to provide improve predictions of stroke recurrence in patients with IVBAS.

Recurrent stroke risk in intracranial atherosclerotic disease

Recurrent stroke risk secondary to intracranial atherosclerotic disease remains high despite aggressive medical treatment. This risk is further amplified in subgroups possessing biomarkers of hemodynamic insufficiency and potential for embolization, which have been shown to be independently and synergistically predictive of recurrent stroke. Luminal stenosis was predominantly used as entry criteria in major treatment trials, discounting the potential role of hemodynamics from primary analyses, limiting the strength of evidence and conclusions of these biomarkers to post-hoc analyses and other natural history studies. Future treatment trials should consider stratifying patients using a combination of these high-risk biomarkers. In the absence of trials, risk stratifying patients based on the presence of these markers may lend to more individualized clinical decisions. We aimed to summarize the studies that have investigated the relationship between biomarkers and their role in predicting recurrent stroke risk in intracranial atherosclerotic disease.

The MRI enhancement ratio and plaque steepness may be more accurate for predicting recurrent ischemic cerebrovascular events in patients with intracranial atherosclerosis

OBJECTIVES

To assess the complementary value of high-resolution multi-contrast MRI (hrMRI) in identifying symptomatic patients with intracranial atherosclerosis (ICAS) who are likely to experience recurrent ischemic cerebrovascular events.

METHODS

In this retrospective cohort study, eighty patients with acute ischemic events attributed to ICAS who underwent hrMRI examination between January 2015 and January 2019 were included. Median follow-up for all patients was 30 months (range: 1 to 52 months) and recurrent ischemic cerebrovascular events were recorded. Cox regression analysis and time-dependent ROC were performed to quantify the association between the plaque characteristics and recurrent events.

RESULTS

During the follow-up, 14 patients experienced recurrent ischemic cerebrovascular events. Young males and those with diabetes and poor medication persistence were more likely to experience recurrent events. ICAS in patients with recurrence had significantly higher enhancement ratio and steepness which is defined as the ratio between the plaque height and length than those without (p < 0.001 and p = 0.015, respectively). After adjustment of clinical factors, enhancement ratio (HR, 13.13 [95% CI, 3.58-48.20], p < 0.001) and plaque steepness (HR, 110.27 [95% CI, 4.75-2560.91], p = 0.003) were independent imaging biomarkers associated with recurrent events. Time-dependent ROC indicated that integrated high enhancement ratio and steepness into clinical risk factors improved discrimination power with the ROC increased from 0.79 to 0.94 (p = 0.008).

CONCLUSIONS

The enhancement ratio and plaque steepness improved the accuracy over traditional clinical risk factors in predicting recurrent ischemic cerebrovascular events for patients with ICAS.

KEY POINTS

• High-resolution magnetic resonance imaging helps clinicians to evaluate high-risk Intracranial plaque. • The higher enhancement ratio and plaque steepness (= height/length) were the primary biomarkers associated with future ischemic cerebrovascular events. • High-resolution magnetic resonance imaging combined with clinical characteristics showed a higher accuracy for the prediction of recurrent events in patients with intracranial atherosclerosis.

Radiomics Nomogram for Predicting Stroke Recurrence in Symptomatic Intracranial Atherosclerotic Stenosis

Objective

To develop and validate a radiomics nomogram for predicting stroke recurrence in symptomatic intracranial atherosclerotic stenosis (SICAS).

Methods

The data of 156 patients with SICAS were obtained from the hospital database. Those with and without stroke recurrence were identified. The 156 patients were separated into a training cohort (n = 110) and a validation cohort (n = 46). Baseline clinical data were collected from our medical records, and plaque radiological features were extracted from vascular wall high-resolution imaging (VW-HRMRI). The imaging sequences included 3D-T1WI-VISTA, T2WI, and 3D-T1WI-VISTA-enhanced imaging. Least absolute shrinkage and selection operator (LASSO) analysis were used to select the radiomics features associated with stroke recurrence. Then, multiple logistic regression analysis of clinical risk factors, radiological features, and radiomics signatures were performed, and a predictive nomogram was constructed to predict the probability of stroke recurrence in SICAS. The performance of the nomogram was evaluated.

Results

Diabetes mellitus, plaque burden, and enhancement ratio were independent risk factors for stroke recurrence [odds ratio (OR) = 1.24, 95% confidence interval (CI): 1.04–3.79, p = 0.018; OR = 1.76, per 10% increase, 95% CI, 1.28–2.41, p < 0.001; and OR = 1.94, 95% CI: 1.27–3.09, p < 0.001]. Five features of 3D-T1WI-VISTA, six features of T2WI, and nine features of 3D-T1WI-VISTA-enhanced images were associated with stroke recurrence. The radiomics signature in 3D-T1WI-VISTA-enhanced images was superior to the radiomics signature of the other two sequences for predicting stroke recurrence in both the training cohort [area under the curve (AUC), 0.790, 95% CI: 0.669–0.894] and the validation cohort (AUC, 0.779, 95% CI: 0.620–0.853). The combination of clinical risk factors, radiological features, and radiomics signature had the best predictive value (AUC, 0.899, 95% CI: 0.844–0.936 in the training cohort; AUC, 0.803, 95% CI: 0.761–0.897 in the validation cohort). The C-index of the nomogram was 0.880 (95% CI: 0.805–0.934) and 0.817 (95% CI: 0.795–0.948), respectively, in the training and validation cohorts. The decision curve analysis further confirmed that the radiomics nomogram had good clinical applicability with a net benefit of 0.458.

Conclusion

The radiomics features were helpful to predict stroke recurrence in patients with SICAS. The nomogram constructed by combining clinical high-risk factors, plaque radiological features, and radiomics features is a reliable tool for the individualized risk assessment of predicting the recurrence of SICAS stroke.

ATHEROMATOSIS OF THE BRAIN-SUPPLYING ARTERIES: CIRCLE OF WILLIS, BASILAR, VERTEBRAL AND THEIR BRANCHES

PURPOSE

Atherosclerotic plaques in the brain-supplying arteries are slowly-developing alterations of vascular structures that can lead to neurological impairment due to stenosis and insufficient oxygenation of eloquent brain areas. The aim of this study is to provide detailed demographic information related to the incidence of atherosclerotic plaques in the cerebral arteries.

MATERIAL AND METHODS

Forty-eight circles of Willis (21 men, 21 women, mean age: 70.26, six samples unknown) were macroscopically analyzed for length, diameter, and presence of atherosclerotic plaques. Statistical analysis was used to identify potential differences in the locations and frequencies of atherosclerotic plaques in relation to age and sex.

RESULTS

The study sample revealed 261 atherosclerotic plaques. The key findings were significant correlations between plaque development and age and between plaque location and age; however, there was no significant sex difference.

CONCLUSION

The upper and lower branches of the middle cerebral artery (MCA) were novel locations predisposing to plaque development. A cut-off value at 60 years revealed a significant difference in plaque development and distribution. There were no significant sex differences in the occurrence of atherosclerotic plaques.

Effects of Early-Stage Blood Pressure Variability on the Functional Outcome in Acute Ischemic Stroke Patients With Symptomatic Intracranial Artery Stenosis or Occlusion Receiving Intravenous Thrombolysis

Background

Studies exploring the relationship between blood pressure (BP) fluctuations and outcome in acute ischemic stroke (AIS) patients treated with intravenous thrombolysis (IVT) are limited. We aimed to investigate the influence of blood pressure variability (BPV) during the first 24 h after IVT on early neurological deterioration (END) and 3-month outcome after IVT in terms of different stroke subtypes.

Methods

Clinical data from consecutive AIS patients who received IVT were retrospectively analyzed. The hourly systolic BP of all patients were recorded during the first 24 h following IVT. We calculated three systolic BPV parameters, including coefficient of variability (CV), standard deviation of mean BP (SD) and successive variation (SV), within the first 6, 12, and 24 h after IVT. END was defined as neurological deterioration with an increase in the National Institutes of Health Stroke Scale (NIHSS) score ≥ 4 points within the first 72 h after admission. Follow-up was performed at 90 days after onset, and favorable and poor outcomes were defined as a modified Rankin Scale scores (mRS) of ≤1 or ≥2, respectively.

Results

A total of 339 patients, which were divided into those with (intracranial artery stenosis or occlusion group, SIASO group) and without (non-SIASO group) SIASO, were included. Among them, 110 patients (32.4%) were with SIASO. Patients in SIASO group had higher NIHSS on admission and difference in term of mRS at 90 days compared with non-SIASO group (P < 0.001). In SIASO group, patients in favorable outcome group were younger and had lower NIHSS on admission, lower SV-24 h (14.5 ± 4.3 vs. 11.8 ± 3.2, respectively) and lower SD-24 h (12.7 ± 3.8 vs. 10.9 ± 3.3, respectively), compared with patients with poor outcome (all P < 0.05). In the multivariable logistic regression analysis, compared with the lowest SV (SV < 25% quartile), SV_50−75% [odds ratio (OR) = 4.449, 95% confidence interval (CI) = 1.231–16.075, P = 0.023] and SV_>75% (OR = 8.676, 95% CI = 1.892–39.775, P = 0.005) were significantly associated with poor outcome at 3 months in patients with SIASO, adjusted for age, NIHSS on admission and atrial fibrillation. No BPV parameters were associated with END in SIASO group. In non-SIASO group, there were no significant association between BPV patterns and END or 90-day outcome.

Conclusions

SV-24 h had a negative relationship with 3-month outcome in AIS patients with SIASO treated with IVT, indicating that BPV may affect the outcome of AIS.

Drug-Coated Balloon-Oriented Angioplasty for Severe Symptomatic Atherosclerotic MCA Stenosis in Young Adults

Purpose

The clinical significance of endovascular therapy in young patients with symptomatic intracranial atherosclerotic stenosis is not clear. We aimed to report our preliminary findings on the safety and effectiveness of a new endovascular treatment strategy, drug-coated balloon (DCB)-oriented angioplasty for young adults with severe symptomatic atherosclerotic middle cerebral artery (MCA) stenosis.

Methods

We retrospectively retrieved the data of seven young patients aged 21–32 years old with severe symptomatic atherosclerotic MCA stenosis treated with DCB-oriented angioplasty from January 2018 to October 2020. We collected clinical presentations, perioperative complications, and clinical and radiological outcomes.

Results

The DCB was successfully dilated at the lesions in all seven patients and good antegrade perfusion was achieved in five. The other two patients underwent remedial stent implantation due to residual stenosis >50% and unstable antegrade perfusion after DCB dilatation. However, none of the patients had perioperative complications. There were no recurrent ischemic symptoms after a mean clinical follow-up period of 15.4 ± 6.9 months. Repeat vascular images of the patients showed no restenosis at 3- or 6-month imaging follow-up periods. High-resolution MRI (HRMRI) was completed in all the patients before the angioplasty procedure and at follow-up. Focal eccentric wall thickening was present at the site of stenosis preoperatively; however, the plaques had disappeared by the time of follow-up for all patients.

Conclusion

DCB-oriented angioplasty may be safe and effective for young patients with severe symptomatic atherosclerotic MCA stenosis.

Morphological Subtypes of Intracranial Internal Carotid Artery Arteriosclerosis and the Risk of Stroke

BACKGROUND AND PURPOSE

Accumulating evidence highlights the existence of distinct morphological subtypes of intracranial carotid arteriosclerosis. So far, little is known on the prevalence of these subtypes and subsequent stroke risk in the general population. We determined the prevalence of morphological subtypes of intracranial arteriosclerosis and assessed the risk of stroke associated with these subtypes.

METHODS

Between 2003 and 2006, 2391 stroke-free participants (mean age 69.6, 51.7% women) from the population-based Rotterdam Study underwent noncontrast computed tomography to visualize calcification in the intracranial carotid arteries as a proxy for intracranial arteriosclerosis. Calcification morphology was evaluated according to a validated grading scale and categorized into intimal, internal elastic lamina (IEL), or mixed subtype. Follow-up for stroke was complete until January 1, 2016. We used multivariable Cox regression to assess associations of each subtype with incident stroke.

RESULTS

The prevalence of calcification was 82% of which 39% had the intimal subtype, 48% IEL subtype, and 13% a mixed subtype. During a median follow-up of 10.4 years, 155 participants had a stroke. All 3 subtypes were associated with a higher risk of stroke (adjusted hazard ratio [95% CI] for intimal: 2.11 [1.07-4.13], IEL: 2.66 [1.39-5.11], and mixed subtype 2.57 [1.18-5.61]). The association of the IEL subtype with stroke was strongest among older participants. The association of the intimal subtype with stroke was noticeably stronger in women than in men.

CONCLUSIONS

Calcification of the IEL was the most prevalent subtype of intracranial arteriosclerosis. All 3 subtypes were associated with an increased risk of stroke, with noticeable age and sex-specific differences.

Preventive effects of ginseng against atherosclerosis and subsequent ischemic stroke: A randomized controlled trial (PEGASUS trial)

Background

Korean Red Ginseng (KRG) extract has been shown to have beneficial effects in patients with atherosclerosis, suggesting that KRG extract may be effective in preventing subsequent ischemic stroke in patients with severe atherosclerosis.

Methods

This double-blind, placebo-controlled trial randomized patients with severe atherosclerosis in major intracranial arteries or extracranial carotid artery, to ginseng group and placebo group. They were given two 500-mg KRG tablets or identical placebo tablets twice daily for 12 months according to randomization. The primary endpoint was the composite of cerebral ischemic stroke and transient ischemic attack during 12 months after randomization. The secondary endpoints were change in volumetric blood flow of the intracranial vessels and the incidence of newly developed asymptomatic ischemic lesions. Any adverse events were monitored.

Results

Fifty-eight patients were randomized from June 2016 to June 2017, 29 to ginseng and 29 to placebo, and 52 (28 and 24, respectively) completed the study. One patient in the placebo group, but none in the ginseng group, experienced ischemic symptoms (p = 0.46). Changes in volumetric blood flow and the presence of ischemic brain lesions did not differ significantly in the two groups, and none of these patients experienced adverse drug reactions.

Conclusion

Ginseng was well tolerated by patients with severe atherosclerosis, with these patients showing good compliance with ginseng dosing. Ginseng did not show significant effects compared with placebo, although none of the ginseng-treated patients experienced ischemic events. Long-term studies in larger patient populations are required to test the effect of ginseng.

Safety and effect of Neuroform Atlas stent in the treatment of symptomatic intracranial stenosis: A single-center experience

Background

Vascular intracranial stenosis (IS) is a significant cause of acute ischemic stroke (AIS). This single-center study aims to show that symptomatic IS treatment by using the Neuroform Atlas stent (Stryker neurovascular, Kalamazoo, MI, USA) could be effective in reducing vessel stenosis.

Methods

Ten patients affected by AIS or TIA, in the vascular territory of high-grade intracranial atherosclerotic lesions (>70% of vessel stenosis), older than 18-year-old, were treated by implanting a Neuroform Atlas stent (diameter of 4.5mm in 80% and 4mm in 20%). 70% of the patients underwent pre-stenting intracranial angioplasty.

Results

Patients were between 54.8 and 83 years old (mean 68.46y ± 8.44y), 70% males and 30% females. At admission, 50% of all patients had an AIS and 50% a TIA. Restoration of the stenotic lumen was obtained after the endovascular procedure. The percentage mean of vascular stenosis was 83.7% ± 6.09% before treatment (t0), 52.2% ± 10.42% at the end of treatment (t1) and 46.2% ± 8.28% at the follow-up (t2). The IS percentage mean reduction between t0 and t1 was 31.5% ± 7.31%, and between t1 and t2 was 6% ± 5.47%, t0 and t2 of 37.5% ± 7.38%. Percentage reduction of IS was highly significant between time t0 and t1 (p = 0.005), and t0 and t2 (p = 0.005), also with a significant reduction between t1 and t2 (p = 0.012). No patient had experienced an increase of the ischemic area in the vascular territory of the target vessel at 3 months from the initial assessment. 10% of patients experienced a 3-months negative outcome (mRS = 5), 90% experienced a favorable outcome (mRS ≤2).

Conclusions

Intracranial stenosis endovascular treatment with Neuroform Atlas stent provides encouraging results, with a statistically significant association between the vascular caliber improvement and the endovascular treatment.

Therapeutic Potential of Remote Ischemic Conditioning in Vascular Cognitive Impairment

Vascular cognitive impairment (VCI) is a heterogeneous disease caused by a variety of cerebrovascular diseases. Patients with VCI often present with slower cognitive processing speed and poor executive function, which affects their independence in daily life, thus increasing social burden. Remote ischemic conditioning (RIC) is a non-invasive and efficient intervention that triggers endogenous protective mechanisms to generate neuroprotection. Over the past decades, evidence from basic and clinical research has shown that RIC is promising for the treatment of VCI. To further our understanding of RIC and improve the management of VCI, we summarize the evidence on the therapeutic potential of RIC in relation to the risk factors and pathobiologies of VCI, including reducing the risk of recurrent stroke, decreasing high blood pressure, improving cerebral blood flow, restoring white matter integrity, protecting the neurovascular unit, attenuating oxidative stress, and inhibiting the inflammatory response.

Intracranial Atherosclerotic Plaque Characteristics and Burden Associated With Recurrent Acute Stroke: A 3D Quantitative Vessel Wall MRI Study

Background: Intracranial atherosclerotic disease (ICAD) tends to affect multiple arterial segments, and previous studies rarely performed a comprehensive plaque analysis of the entire circle of Willis for the evaluation of recurrent stroke risk. We aimed to investigate the features of circle of Willis ICAD on 3D magnetic resonance vessel wall imaging (MR-VWI) and their relationships with recurrent acute stroke. Methods: Patients with either acute ischemic stroke (within 4 weeks after stroke) or chronic ischemic stroke (after 3 months of stroke) due to intracranial atherosclerotic plaque underwent 3D contrast-enhanced MR-VWI covering major cerebral arteries. Participants were divided into three groups: first-time acute stroke, recurrent acute stroke, and chronic stroke. Culprit plaque (defined as the only lesion or the most stenotic lesion when multiple plaques were present within the same vascular territory of the stroke) and non-culprit plaque characteristics, including total plaque number, plaque thickness, plaque area, plaque burden (calculated as plaque area divided by outer wall area), enhancement ratio (ER), eccentricity, and stenosis, were measured and compared across the three groups. Associations between plaque characteristics and recurrent acute stroke were investigated by multivariate analysis. Results: A total of 176 participants (aged 61 ± 10 years, 109 men) with 702 intracranial plaques were included in this study. There were 80 patients with first-time acute stroke, 42 patients with recurrent acute stroke, and 54 patients with chronic stroke. More intracranial plaques were found per patient in the recurrent acute stroke group than in the first-time acute stroke or chronic stroke group (5.19 ± 1.90 vs. 3.71 ± 1.96 and 3.46 ± 1.33, p < 0.001). Patients in the recurrent acute stroke group had greater culprit plaque burden (p < 0.001) and higher culprit ER (p < 0.001) than the other two groups. After adjustment of clinical demographic factors, in multivariate analysis, coronary artery disease (CAD) (odds ratio, OR = 4.61; p = 0.035), total plaque number (OR = 1.54; p = 0.003), culprit plaque ER (OR = 2.50; p = 0.036), and culprit plaque burden (OR per 10% increment = 2.44; p = 0.010) were all independently associated with recurrent acute stroke compared to the first-time acute stroke. Conclusion: Increased intracranial atherosclerotic plaque number, higher culprit plaque ER, greater culprit plaque burden, and CAD are independently associated with recurrent acute stroke.

Drug-Coated Balloons for the Treatment of Symptomatic Intracranial High-Grade Stenosis: A Review of the Current Rationale

Symptomatic intracranial atherosclerotic disease (sICAD) remains a challenging disorder in the neurovascular field. Despite best medical treatment, the recurrence rate for stroke remains high in patients with intracranial high-grade stenosis (>70–99%). Furthermore, two large randomized trials (SAMMPRIS and VISSIT) failed to prove the efficacy of percutaneous transluminal angioplasty and stenting in patients with sICAD. Drug-coated balloon percutaneous transluminal angioplasty (DCB-PTA) represents an alternative treatment modality with therapeutic benefits for interventional cardiology. However, there are very few articles in the existing literature that relate to the use of DCB-PTA in sICAD patients. Here, we aimed to review the rationale underlying the use of DCB-PTA in sICAD patients and summarize recent developments in the neurovascular field.

Association between coexisting intracranial artery and extracranial carotid artery atherosclerotic diseases and ipsilateral cerebral infarction: a Chinese Atherosclerosis Risk Evaluation (CARE-II) study

BACKGROUND

To evaluate the association between coexisting intracranial and extracranial carotid artery atherosclerotic diseases and ipsilateral acute cerebral infarct (ACI) in symptomatic patients by using magnetic resonance (MR) vessel wall imaging.

METHODS

Symptomatic patients were recruited from a cross-sectional, multicentre study of Chinese Atherosclerosis Risk Evaluation (CARE-II). All patients underwent MR imaging for extracranial carotid arterial wall, intracranial artery and brain. Coexisting intracranial stenosis ≥50% and extracranial carotid artery mean wall thickness (MWT) ≥1 mm and plaque compositions at the same side were evaluated and the ipsilateral ACI was identified. The association between coexisting atherosclerotic diseases and ACI was evaluated using logistic regression.

RESULTS

351 patients were recruited. Patients with ipsilateral ACI had significantly greater prevalence of coexisting intracranial stenosis ≥50% and carotid MWT ≥1 mm (20.5% vs 4.9%, p<0.001), calcification (15.1% vs 4.4%, p=0.001) and lipid-rich necrotic core (LRNC) (19.2% vs 7.8%, p=0.002) compared with those without. Coexisting intracranial artery stenosis ≥50% and carotid MWT ≥1 mm (OR 5.043, 95% CI 2.378 to 10.694; p<0.001), calcification (OR 3.864, 95% CI 1.723 to 8.664; p=0.001) and LRNC (OR 2.803, 95% CI 1.455 to 5.401; p=0.002) were significantly associated with ipsilateral ACI. After adjusting for confounding factors, the aforementioned associations remained statistically significant (intracranial stenosis ≥50% coexisting with carotid MWT ≥1 mm: OR 4.313, 95% CI 1.937 to 9.601, p<0.001; calcification: OR 3.606, 95% CI 1.513 to 8.593, p=0.004; LRNC: OR 2.358, 95% CI 1.166 to 4.769, p=0.017).

CONCLUSIONS

Coexistence of intracranial artery severe stenosis and extracranial carotid artery large burden and intraplaque components of calcification and LRNC are independently associated with ipsilateral ACI.

TRIAL REGISTRATION NUMBER

https://www.clinicaltrials.gov/. Unique identifier: NCT02017756.

Progression of Plaque Burden of Intracranial Atherosclerotic Plaque Predicts Recurrent Stroke/Transient Ischemic Attack: A Pilot Follow-Up Study Using Higher-Resolution MRI

BACKGROUND

Patients with intracranial atherosclerotic disease (ICAD) have a high frequency of stroke recurrence. However, there has been little investigation into the prognostic value of higher-resolution magnetic resonance imaging (HR-MRI).

PURPOSE

To investigate the use of intracranial atherosclerotic plaques features in predicting risk of recurrent cerebrovascular ischemic events using HR-MRI.

STUDY TYPE

Prospective.

POPULATION

Fifty-eight patients with acute/subacute stroke (N = 46) or transient ischemic attack (N = 12).

FIELD STRENGTH/SEQUENCE

A 3.0 T, 3D time-of-flight gradient echo sequence and T1- and T2-weighted fast spin echo sequences with 0.31 x 0.39 mm² in-plane resolution, twice (with >3 months between scans) following the initial event.

ASSESSMENT

Patients were also followed clinically for recurrent ischemic events for up to 48 months or until a subsequent event occurred. The degree of stenosis, plaque burden (PB), minimal lumen area (MLA), and contrast enhancement ratio were assessed at each scanning session and the percentage change of each over time was calculated.

STATISTICAL TESTS

Univariable and multivariable Cox regression analyses were used to calculate the hazard ratio (HR) and 95% confidence interval (CI) for predicting recurrent events.

RESULTS

The mean time interval between baseline and follow-up MRI scans was 6.2 ± 4.1 months. After the second MRI scan, 20.7% of patients (N = 12) had experienced ipsilateral recurrent TIA/stroke within 10.9 ± 9.2 months. Univariable analyses showed that baseline triglyceride, percentage change of PB, and progression of PB were significantly associated with recurrent events (all P < 0.05). Multivariable Cox regression indicated that progression of PB (HR, 6.293; 95% CI, 1.620-24.444; P < 0.05) was a significant independent imaging feature for recurrent ischemic events.

DATA CONCLUSION

Progression of PB was independently associated with recurrent ischemic cerebrovascular events. HR-MRI may help risk stratification of patients at risk of recurrent stroke.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 4.

Cerebral autoregulation is heterogeneous in different stroke mechanism of ischemic stroke caused by intracranial atherosclerotic stenosis

BACKGROUND AND PURPOSE

Intracranial atherosclerotic stenosis (ICAS) is the most common cause of ischemic stroke (IS) and is associated with stroke recurrence. It results in IS due to a variety of mechanisms. However, the influence of brain reserve mechanism on different stroke mechanism is still unclear. Cerebral autoregulation (CA) is an important brain reserve mechanism and is impaired after IS. This study aimed to explore the impaired pattern of CA and assess the association between CA and stroke risk factors in different stroke mechanism caused by ICAS.

METHODS

IS patients with ICAS (50%-99% stenosis/occlusion) in middle cerebral artery (MCA) or internal carotid artery were enrolled to receive CA examinations within 7 days after onset. Healthy volunteers were also recruited as controls. CA was recorded from spontaneous fluctuations of blood pressure and MCA flow velocity. Transfer function analysis was used to derive CA parameters, including phase difference (PD) and coherence in the low-frequency range (0.06-0.12 Hz).

RESULTS

A total of 89 IS patients and 90 healthy controls were included. Compared with controls, CA was impaired ipsilaterally in patients with parent artery atherosclerosis occluding penetrating artery (POPA) while CA was bilaterally impaired in other stroke mechanisms. And CA on ipsilateral hemisphere was correlated with hypertension/hyperlipidemia in patients with POPA (r = -0.481, p = .008; r = -0.484, p = .008). While CA on ipsilateral hemisphere was correlated with perfusion parameter including the arterial spin-labeling (ASL) parameter cerebral blood flow (CBF) (r = 0.893, p = .007) and collateral circulation status the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) (r = 0.610, p = .021) in patients with hypoperfusion mechanism.

CONCLUSION

In IS patients, CA was impaired heterogeneously and was correlated with different risk factors in varied stroke mechanism. CA can be as an informative determinant of stroke risk in patients with ICAS and to help improving individualized treatment strategies in the presence of ischemic stroke caused by ICAS.

Risk of Recurrence of Symptomatic Intracranial Atherosclerosis in Posterior Circulation Seen to Be Higher Than That in Anterior Circulation in Long-Term Follow-Up

Background: Intracranial atherosclerotic stenosis (ICAS) is an important cause of ischemic stroke. In Asians, intracranial atherosclerotic disease leads to 33-50% of ischemic events. At present, treatment with medication vs. endovascular therapy (EVT) for symptomatic ICAS (sICAS) patients is still debatable. The clinical prognosis of patients who are not completely free of stroke symptoms despite regular medication and are not eligible for EVT for various reasons, is not yet investigated. Aim: To report the long-term recurrence rate of stroke in a cohort of symptomatic ICAS patients who intended to undergo EVT upon admission but could not for various reasons after digital subtraction angiography (DSA) evaluation. Method: This is a retrospective analysis of consecutive sICAS patients in a single center from January 1, 2016 to August 31, 2017 who underwent DSA assessment alone and were not eligible for further EVT. Demographic information, risk factors related to cerebrovascular disease, clinical comorbidities, medication, imaging data, and long-term outcomes were reported. Results: A total of 218 patients were included in the study; 42 (19.2%) patients had recurrence of stroke/transient ischemic attack (TIA) at the 1-year follow up. Patients were divided into two groups according to lesions in anterior circulation (n = 120) or posterior circulation (n = 98). There was a higher stroke/TIA recurrence rate in the posterior circulation than anterior circulation group (25.5 vs. 14.2%, p = 0.035). Given the advanced age, higher prevalence of coronary heart disease, larger stenosis length, and poorer collateral circulation, the posterior circulation group showed a higher risk of recurrent stroke/TIA and death than the anterior circulation group [HR = 3.092, 95% CI (1.335-7.164), p = 0.0084], after adjusting for all confounding factors in the COX regression model. Kaplan-Meier analysis showed that sICAS recurrence and mortality risk in the posterior circulation group was consistently higher than that in the anterior circulation group (log-rank-test, p = 0.033). Conclusions: Patients with posterior circulation sICAS have higher recurrence risk than those with anterior circulation managed with medication alone. Further, posterior circulation lesion is an independent risk factor for recurrence in sICAS patients.

Multiple Ischemic Strokes Associated with Childhood Progressive Radiation-Induced Occlusive Cerebral Vasculopathy

There is little knowledge on the pathophysiology of pediatric stroke associated with radiation-induced occlusive cerebral vasculopathy (RIOCV). Herein, we present an extremely rare case of a child with multiple ischemic strokes in association with progressive RIOCV. The possibility of hemodynamic compromise and artery-to-artery embolism as a cause of the ischemic events is discussed.

Improvement of Cerebrovascular Reserve by Percutaneous Transluminal Angioplasty for Symptomatic Middle Cerebral Artery Stenosis

Objective

The purpose of this study was to investigate the efficacy of percutaneous transluminal angioplasty (PTA) for symptomatic middle cerebral artery stenosis by analyzing cerebral blood flow (CBF).

Methods

Between January 2016 and December 2018, six patients with symptomatic middle cerebral artery stenosis underwent CBF analysis by single-photon emission computed tomography (SPECT) with acetazolamide challenge before and after PTA for stenosis. They were retrospectively reviewed, and the blood flow in the area of the affected middle cerebral artery before and after angioplasty was compared.

Results

The mean stenosis rate and length of lesion before angioplasty were 76.4 ± 5.4% and 6.5 ± 2.1 mm, respectively. Balloon angioplasty without stenting was performed on all patients. The mean residual stenosis rate just after angioplasty was 45.4 ± 9.3%. No periprocedual complications developed, and there were no notable cerebral ischemic events during the postprocedural follow-up period. One patient underwent repeat angioplasty for restenosis. Although there was only a mild decrease in blood flow at rest, the cerebrovascular reserve (CVR) in the area of the affected middle cerebral artery was markedly decreased before angioplasty (mean, 3.6 ± 4.3%). After angioplasty, the CVR was significantly improved (mean, 18.0 ± 4.7%, p <0.01).

Conclusions

PTA for symptomatic middle cerebral artery stenosis can be safely performed using appropriate interventional techniques for select patients. Reduced CVR due to stenosis can be improved after angioplasty, which may reduce the risk of cerebral ischemic events.

Classification of Intracranial Stenoses: Discrepancies between Transcranial Duplex Sonography and Computed Tomography Angiography

Transcranial color-coded duplex sonography (TCCS) and computed tomography angiography (CTA) are widely used to identify intracranial stenoses (ISs). We assessed concordance of IS grading between TCCS and CTA and proposed new TCCS criteria for severe IS ≥70%. One hundred two stroke patients (70 ± 13 y) with TCCS-identified IS were included. TCCS and CTA were performed within 24 h after admission. TCCS peak systolic velocity cutoffs for <50%/50%-69% stenoses were ≥155/≥220 cm/s (middle cerebral artery [MCA]-M1), ≥100/≥140 cm/s (MCA-M2), ≥120/≥155 cm/s (anterior cerebral artery [ACA]-A1), ≥100/≥145 cm/s (posterior cerebral artery [PCA]-P1 and PCA-P2), ≥90/≥120 cm/s (vertebral artery [VA]-V4) and ≥100/≥140 cm/s (basilar artery [BA]). Criteria for ≥70% stenoses were, despite variable flow velocities, post-stenotic flow alterations and/or leptomeningeal collateral flow. One hundred seventy-seven ISs were detected by TCCS. The number and grade (<50%/50%-69%/≥70%) of ISs were MCA 70 (39/19/12), BA 24 (9/11/4), ACA 21 (14/7/0), PCA 49 (29/15/5) and VA 13 (2/6/5). IS localization was confirmed by CTA in 84 of 177 cases (48%): MCA, 41/70 (59%); BA, 16/24 (67%); ACA 2/21, (10%); PCA, 17/49 (35%); VA, 8/13 (62%). Concordance between TCCS and CTA grading was (<50%/50%-69%/≥70%) 17%/19%/77%. TCCS and CTA exhibited substantial differences in the detection and grading of IS. Higher concordance rates for severe stenosis support our proposed TCCS criteria.

Prevalence, predictors, and prognosis of symptomatic intracranial stenosis in patients with transient ischaemic attack or minor stroke: a population-based cohort study

BACKGROUND

Symptomatic intracranial stenosis was perceived to convey a high risk of recurrent stroke, but two previous trials (SAMMPRIS and VISSIT) did not show superiority of intracranial stenosis stenting over intensive medical management alone. These findings were partly due to a lower than expected risk of recurrent stroke without stenting, possibly reflecting the young age of recruits (median age <60 years), and raise questions about generalisability to routine clinical practice. We therefore studied the age-specific prevalence, predictors, and prognosis of symptomatic intracranial stenosis in a population-based cohort of patients with transient ischaemic attack and minor stroke on intensive medical management.

METHODS

The Oxford Vascular Study (OXVASC) is a prospective incidence cohort study of all vascular events in a population of 92 728 people residing in Oxfordshire, UK. All patients, irrespective of age, with transient ischaemic attack and minor ischaemic stroke occurring between March 1, 2011, and March 1, 2018 (follow-up to Sept 28, 2018), were ascertained with multiple methods, including assessment in a dedicated daily emergency clinic and daily review of all hospital admissions. Imaging was by MR angiography of the intracranial and cervicocranial arteries, by CT angiography if MR angiography was contraindicated, and by transcranial Doppler and carotid ultrasound if CT angiography was contraindicated. All patients received intensive medical treatment without stenting, and those with intracranial vascular imaging were analysed in our study, which assessed the age-specific prevalence of 50-99% intracranial stenosis and the associated stroke risk of 50-99% and 70-99% stenosis (adjusted for age and vascular risk factors) during follow-up to Sept 28, 2018.

FINDINGS

Of 1368 eligible patients with intracranial vascular imaging, 241 (17·6%) had 385 50-99% symptomatic or asymptomatic intracranial stenosis. The prevalence of symptomatic 50-99% intracranial stenosis increased from 29 (4·9%) of 596 at younger than 70 years to 10 (19·6%) of 51 at 90 years or older (p_trend<0·0001). Of 94 patients with 50-99% symptomatic intracranial stenosis, 14 (14·9%) had recurrent strokes (12 ischaemic and two haemorrhagic) during a median follow-up of 2·8 years (IQR 1·5-4·6). Although symptomatic intracranial stenosis conveyed an increased risk of ischaemic stroke compared with no intracranial stenosis (adjusted hazard ratio 1·43, 95% CI 1·04-1·96), the risk of same-territory ischaemic stroke in patients with 70-99% symptomatic intracranial stenosis tended to be less than those reported in the non-stenting groups of the previous trials (1-year risk 5·6% [95% CI 0·0-13·0] vs 9·4% [3·1-20·7] in VISSIT; 2-year risk 5·6% [0·0-13·0] vs 14·1% [10·1-19·4] in SAMMPRIS).

INTERPRETATION

The prevalence of 50-99% symptomatic intracranial stenosis increases steeply with age in predominantly Caucasian patients with transient ischaemic attack and minor ischaemic stroke. However, the risk of recurrent stroke on intensive medical treatment of symptomatic intracranial stenosis is consistent with the two previous randomised controlled trials in younger cohorts, supporting the generalisability of the trial results to routine practice.

FUNDING

Wellcome Trust, Wolfson Foundation, British Heart Foundation, National Institute for Health Research, National Institute for Health Research Oxford Biomedical Research Centre, Association of British Neurologists.

Comparison of Risk Factors, Treatment, and Outcome in Patients with Symptomatic Intracranial Atherosclerotic Disease in India and the United States

BACKGROUND AND AIMS

Intracranial atherosclerotic disease (ICAD) is common in the Asian population, but less studied in South Asians compared to East Asians. We compared risk factors, treatments, and outcomes among consecutive patients with symptomatic ICAD from India with a mixed-ethnic cohort from Chicago, Illinois.

METHODS

Consecutive patients with symptomatic ICAD were enrolled at 2 academic medical centers in Kerala, India and Chicago, United States. Data on demographics, risk factors, initial stroke severity (National Institute of Health Stroke Scale score [NIHSS]), recurrent stroke, and 3-month functional outcome (modified Rankin Scale [mRS]) were prospectively collected. Recurrent stroke was defined as symptomatic recurrence of focal neurologic deficits associated with radiographic evidence of new cerebral infarction within 3 months of index admission.

RESULTS

329 patients (117 from Kerala, 212 from Chicago) were included. Indian patients were younger (61 vs. 68, P < 0.001), less frequently had prior stroke history (15.4 vs. 32.5%, P = 0.001) and coronary artery disease (11.1 vs. 22.2%, P = 0.013) but had higher initial NIHSS score (median 6 vs. 3, P < 0.001). Both groups received reperfusion therapy in similar proportions (8.5 vs. 7.1%, P = 0.630) but at discharge, 90.6% of Indian patients compared to 59.0% of Chicago patients were treated with dual antiplatelet therapy. More recurrent strokes occurred in Chicago patients (21.7 vs. 1.9%, P < 0.001) but functional outcome did not differ significantly.

CONCLUSION

Compared to patients in US with symptomatic ICAD, Indian patients were younger and had more severe strokes. However, Indian patients had lower rates of recurrent stroke, perhaps due to greater use of dual antiplatelet therapy.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Device profile of different paclitaxel-coated balloons: Neuro Elutax SV, Elutax '3' Neuro and SeQuent Please NEO for the treatment of symptomatic intracranial high-grade stenosis: overview of their feasibility and safety

Introduction: Intracranial atherosclerotic disease (ICAD) is highly prevalent and probably the most common cause of stroke worldwide. Despite best medical treatment (BMT), the rate of recurrent stroke in symptomatic ICAD patients is elevated, especially in those with high-grade stenosis. Thus, alternative treatment options are needed. So far, endovascular ICAD treatment has been considered a second-line therapy. However, recent progress in the endovascular acute stroke treatment challenges this issue. Drug-coated balloon (DCB) - percutaneous transluminal angioplasty (PTA) represents a promising alternative to BMT alone.Areas covered: In this review, current clinical studies on paclitaxel-coated DCB-PTA in symptomatic high-grade ICAD patients will be presented and discussed. Furthermore, technical profile of the different paclitaxel-coated DCB, which has been used for intracranial use (Neuro Elutax SV, Elutax '3' Neuro, and SeQuent Please NEO) are being presented.Expert opinion: Despite limited data and its experimental (off-line) use, DCB-PTA has been demonstrated to be feasible and safe in selected ICAD patients with symptomatic high-grade stenosis. DCB-PTA offers several advantages compared to alternative endovascular therapy option as well as BMT alone. Consequently, DCP-PTA might be a promising candidate for the future armamentarium in ICAD treatment.

A novel technique for stenting in cases of refractory intracranial stenosis

Endovascular management of intracranial stenosis is one of the most controversial subjects in neurointervention. Previous level 1 evidence shows superiority of medical management but more recent studies have shown improved outcomes in selective patients. We describe a case demonstrating a new method for stenting of intracranial stenosis using a single system with Coyote angioplasty balloon (Boston Scientific) and the Atlas stent (Stryker).

Higher Plaque Burden of Middle Cerebral Artery Is Associated With Recurrent Ischemic Stroke: A Quantitative Magnetic Resonance Imaging Study

Background and Purpose- This study aims to investigate the association between the characteristics of atherosclerotic plaques of middle cerebral artery and recurrent ischemic stroke using magnetic resonance vessel wall imaging. Methods- One hundred and five patients with ischemic stroke attributed to middle cerebral artery plaque underwent high-resolution black-blood magnetic resonance vessel wall imaging. They were divided into group 1, with the first episode of acute stroke (imaging within 4 weeks of stroke, n=44); group 2, with recurrent acute stroke (n=29); and group 3, with chronic stroke (imaging after 3 months of stroke, n=32). Plaque characteristics including plaque area, plaque burden, contrast-enhancement ratio, eccentricity, and degree of stenosis were measured and compared across 3 groups. Association between plaque characteristics and recurrent strokes was investigated by multivariate analysis. Results- Plaque burden was significantly greater in recurrent stroke group than the other 2 groups (median: group 2, 82.7%, versus group 1, 76.3%, and group 3, 73.4%; P=0.001). Patients with acute stroke had higher enhancement ratio than patients with chronic stroke (median: group 1, 1.59, and group 2, 1.90, versus group 3, 1.33; P=0.014). Comparing to first-onset acute stroke patients, recurrent stroke patients were older, more likely with female sex and hypertension, and had higher plaque burden. After adjustment of clinical factors, plaque burden was the only independent imaging feature associated with recurrent stroke (odds ratio, 2.26, per 10% increase [95% CI, 1.03-4.96]; P=0.042). Conclusions- Higher plaque burden of middle cerebral artery identified on magnetic resonance vessel wall imaging is independently associated with recurrent ischemic stroke.

Hypoperfusion Symptoms Poorly Predict Hemodynamic Compromise and Stroke Risk in Vertebrobasilar Disease

Background and Purpose- Cerebral hypoperfusion symptoms (defined as symptoms related to change in position, effort or exertion, or recent change in antihypertensive medication) have been used in stroke studies as a surrogate for detecting hemodynamic compromise. However, the validity of these symptoms in identifying flow compromise in patients has not been well established. We examined whether hypoperfusion symptoms correlated with quantitative measurements of flow compromise in the prospective, observational VERiTAS study (Vertebrobasilar Flow Evaluation and Risk of Transient Ischemic Attack and Stroke). Methods- VERiTAS enrolled patients with recent vertebrobasilar transient ischemic attack or stroke and ≥50% atherosclerotic stenosis or occlusion in vertebral or basilar arteries. Hemodynamic status using vertebrobasilar large vessel flow was measured using quantitative magnetic resonance angiography, and patients were designated as low, borderline, or normal flow based on distal territory regional flow, incorporating collateral capacity. The presence of qualifying event hypoperfusion symptoms was assessed relative to the quantitatively determined flow status (normal versus borderline/low) and also examined as a predictor of subsequent stroke risk. Results- Of the 72 enrolled subjects, 66 had data on hypoperfusion symptoms available. On initial quantitative magnetic resonance angiography designation, 43 subjects were designated as normal flow versus 23 subjects designated as low flow (n=16) or borderline flow (n=7). Of these, 5 (11.6%) normal flow and 3 (13.0%) low/borderline flow subjects reported at least one qualifying event hypoperfusion symptom ( P=0.99, Fisher exact test). Hypoperfusion symptoms had a positive predictive value of 37.5% and negative predictive value of 65.5% for low/borderline flow status. Compared with flow status, which strongly predicted subsequent stroke risk, hypoperfusion symptoms were not associated with stroke outcome ( P=0.87, log-rank test). Conclusions- These results suggest that hypoperfusion symptoms alone correlate poorly with actual hemodynamic compromise as assessed by quantitative magnetic resonance angiography and subsequent stroke risk in vertebrobasilar disease, and are not a reliable surrogate for flow measurement. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT00590980.

On the Validation of a Multiple-Network Poroelastic Model Using Arterial Spin Labeling MRI Data

The Multiple-Network Poroelastic Theory (MPET) is a numerical model to characterize the transport of multiple fluid networks in the brain, which overcomes the problem of conducting separate analyses on individual fluid compartments and losing the interactions between tissue and fluids, in addition to the interaction between the different fluids themselves. In this paper, the blood perfusion results from MPET modeling are partially validated using cerebral blood flow (CBF) data obtained from arterial spin labeling (ASL) magnetic resonance imaging (MRI), which uses arterial blood water as an endogenous tracer to measure CBF. Two subjects—one healthy control and one patient with unilateral middle cerebral artery (MCA) stenosis are included in the validation test. The comparison shows several similarities between CBF data from ASL and blood perfusion results from MPET modeling, such as higher blood perfusion in the gray matter than in the white matter, higher perfusion in the periventricular region for both the healthy control and the patient, and asymmetric distribution of blood perfusion for the patient. Although the partial validation is mainly conducted in a qualitative way, it is one important step toward the full validation of the MPET model, which has the potential to be used as a testing bed for hypotheses and new theories in neuroscience research.

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

Importance

Patients who have experienced stroke with intracranial atherosclerotic disease (ICAD) may also have concomitant atherosclerosis in different arterial beds and other possible causes for ischemic stroke. However, little is known about the frequency and prognostic effect of such overlapping diseases.

Objectives

To describe the prevalence of systemic atherosclerotic burdens and overlapping stroke etiologies and their contributions to long-term prognoses among patients who have experienced stroke with ICAD.

Design, Setting, and Participants

The Asymptomatic Myocardial Ischemia in Stroke and Atherosclerotic Disease study is a single-center prospective study in which 405 patients with acute ischemic stroke within 10 days of onset were consecutively enrolled between June 2005 and December 2008 and followed up for 4 years. After excluding 2 patients because of incomplete investigations, 403 were included in this analysis.

Main Outcomes and Measures

Significant ICAD was defined as having 50% or greater stenosis/occlusion by contrast-enhanced/time-of-flight magnetic resonance angiography, computed tomography angiography, and/or transcranial Doppler ultrasonography. Systemic vascular investigations on atherosclerotic disease were performed with ultrasonography in carotid arteries, aorta and femoral arteries, and by angiography in coronary arteries. Coexistent stroke etiologies were assessed using the atherosclerosis, small-vessel disease, cardiac pathology, other cause, and dissection (ASCOD) grading system. We estimated the 4-year risk of major adverse cardiovascular events (MACE), including vascular death, nonfatal cardiac events, nonfatal stroke, and major peripheral arterial events.

Results

Of 403 participants, 298 (74%) were men and the mean (SD) age was 62.6 (13.1) years. Significant ICAD was found in 146 (36.2%). Patients with significant ICAD more often had aortic arch (70 [60.9%] vs 99 [49.0%]; P = .04) and coronary artery (103 [76.9%] vs 153 [63.2%]; P = .007) atherosclerosis than those without. Among patients with ICAD, concurrent stenosis in the extracranial carotid artery (24 [23.4%] vs 3 [9.0%]; P = .08; adjusted hazard ratio[aHR] = 2.12) and the coronary artery (19 [29.9%] vs 8 [12.8%]; P = .01; aHR = 1.90) increased the MACE risk. Furthermore, patients with ICAD who also had any cardiac pathology (ASCOD grade C1-3) were at a higher MACE risk than others (grade C0) (20 [28.2%] vs 7 [11.4%]; P = .01; aHR = 2.24). By contrast, patients with ICAD with any form of small vessel disease (grade S1-3) had a lower MACE risk than those without (grade S0) (20 [17.3%] vs 6 [34.6%]; P = .05; aHR = 0.23).

Conclusions and Relevance

Patients with ICAD often have coexisting systemic atherosclerosis and multiple potential stroke mechanisms that affect their prognosis, suggesting that extensive evaluations of overlapping diseases may allow better risk stratification.