Predictors of Early Infarct Recurrence in Patients With Symptomatic Intracranial Atherosclerotic Disease

Long-term outcome followed for more than 5 years after revascularization surgery for the treatment of atherosclerotic steno-occlusive disease: poor outcome prediction using machine learning and analysis of the results

Cerebral revascularization for the treatment of atherosclerotic steno-occlusive disease (ASOD) was found to have no benefit compared with medical treatment. However, there is also criticism that with sufficiently long-term follow-up, a crossover might emerge demonstrating the advantages of surgery. Therefore, we examined the long-term outcome of cerebral revascularization performed on patients with carefully selected ASOD at our center. Patients undergoing bypass surgery for non-moyamoya ischemic disease were retrospectively identified. The inclusion criteria were symptomatic ASOD with hemodynamic insufficiency, follow-up of more than 5 years, and stroke or surgical complications during follow-up. The clinical course and radiological findings were investigated. Poor outcomes were predicted using machine learning (ML) models, and Shapley additive explanation (SHAP) values and feature importance of each model were analyzed. A total of 109 patients were included from 2007 to 2018. The 30-day risk of any stroke or death was 6.4% (7/109). The risk of ipsilateral ischemic stroke during median follow-up of 116 months was 7.3% (8/109). The SHAP values showed that previously and empirically known stroke risk factors exert a relatively consistent effect on the prediction of models. The number of lesions with stenosis > 50% (odds ratio [OR] 5.77), age (OR 1.13), and coronary artery disease (OR 5.73) were consistent risk factors for poor outcome. We demonstrated an acceptable long-term outcome of cerebral revascularization surgery for patients with hemodynamically insufficient and symptomatic ASOD. Multicenter studies are encouraged to predict poor outcomes and suitable patients with large numbers of quantitative and qualitative data.

Hemodynamic Impairment of Blood Pressure and Stroke Mechanisms in Symptomatic Intracranial Atherosclerotic Stenosis

BACKGROUND

Hemodynamic impairment of blood pressure may play a crucial role in determining the mechanisms of stroke in symptomatic intracranial atherosclerotic stenosis). We aimed to elucidate this issue and assess the impacts of modifications to blood pressure on hemodynamic impairment.

METHODS

From the Third China National Stroke Registry III, computed fluid dynamics modeling was performed using the Newton-Krylov-Schwarz method in 339 patients with symptomatic intracranial atherosclerotic stenosis during 2015 to 2018. The major exposures were translesional systolic blood pressure (SBP) drop and poststenotic mean arterial pressure (MAP), and the major study outcomes were cortex-involved infarcts and borderzone-involved infarcts, respectively. Multivariate logistic regression models and the bootstrap resampling method were utilized, adjusting for demographics and medical histories.

RESULTS

In all, 184 (54.3%) cortex-involved infarcts and 70 (20.6%) borderzone-involved infarcts were identified. In multivariate logistic model, the upper quartile of SBP drop correlated with increased cortex-involved infarcts (odds ratio, 1.92 [95% CI, 1.03-3.57]; bootstrap analysis odds ratio, 2.07 [95% CI, 1.09-3.93]), and the lower quartile of poststenotic MAP may correlate with increased borderzone-involved infarcts (odds ratio, 2.07 [95% CI, 0.95-4.51]; bootstrap analysis odds ratio, 2.38 [95% CI, 1.04-5.45]). Restricted cubic spline analysis revealed a consistent upward trajectory of the relationship between translesional SBP drop and cortex-involved infarcts, while a downward trajectory between poststenotic MAP and borderzone-involved infarcts. SBP drop correlated with poststenotic MAP negatively (rs=-0.765; P<0.001). In generating hemodynamic impairment, simulating blood pressure modifications suggested that ensuring adequate blood pressure to maintain sufficient poststenotic MAP appears preferable to the reverse approach, due to the prolonged plateau period in the association between the translesional SBP drop and cortex-involved infarcts and the relatively short plateau period characterizing the correlation between poststenotic MAP and borderzone-involved infarcts.

CONCLUSIONS

This research elucidates the role of hemodynamic impairment of blood pressure in symptomatic intracranial atherosclerotic stenosis-related stroke mechanisms, underscoring the necessity to conduct hemodynamic assessments when managing blood pressure in symptomatic intracranial atherosclerotic stenosis.

Differences in intracranial atherosclerosis plaque between posterior circulation and anterior circulation on high-resolution magnetic resonance imaging: A systematic review and meta-analysis

OBJECTIVE

The clinical characteristics and mechanisms of stroke caused by anterior circulation atherosclerotic plaques (ACAPs) and posterior circulation atherosclerotic plaques (PCAPs) are distinct. We aimed to compare the differences in vulnerability, morphology, and distribution between ACAPs and PCAPs based on hign-resolution magnetic resonance imaging (HR-MRI).

MATERIALS AND METHODS

The PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), and Wanfang database were retrieved from inception through May 2023. Meta-analysis was performed by R 4.2.1 software. The quality of the literature was assessed by the Agency for Healthcare Research and Quality (AHRQ). Subgroup analysis was conducted to explore the heterogeneity of the pooled results.

RESULTS

There were a total of 13 articles, including 1194 ACAPs and 1037 PCAPs. The pooled estimates demonstrated that the incidence of intraplaque hemorrhage in the PCAPs was higher (OR 1.72, 95%CI 1.35-2.18). The plaque length (SMD 0.23, 95%CI 0.06-0.39) and remodeling index (SMD 0.29, 95%CI 0.14-0.44) of PCAPs were larger than those in ACAPs. However, there were no evident differences in significant enhancement or stenosis degree between the two groups.

CONCLUSION

There were more unstable features in PCAPs, highlighting an elevated risk of recurrent ischemic stroke in the posterior circulation. Furthermore, PCAPs were prone to developing penetrating artery disease due to their wider distribution. Nevertheless, posterior circulation arteries exhibited a greater propensity for outward remodeling, which may lead treatment team to miss the optimal intervention stage by being overlooked on angiographic detection.

Research progress in the relationship between gut microbiota metabolite trimethylamine N-oxide and ischemic stroke

Ischemic stroke (IS) is a severe cerebrovascular disease that seriously endangers human health. Gut microbiota plays a key role as an intermediate mediator in bidirectional regulation between the brain and the intestine. In recent years, trimethylamine N-oxide (TMAO) as a gut microbiota metabolite has received widespread attention in cardiovascular diseases. Elevated levels of TMAO may increase the risk of IS by affecting IS risk factors such as atherosclerosis, atrial fibrillation, hypertension, and type 2 diabetes. TMAO exacerbates neurological damage in IS patients, increases the risk of IS recurrence, and is an independent predictor of post-stroke cognitive impairment (PSCI) in patients. Current research suggests that the mechanisms of TMAO action include endothelial dysfunction, promoting of foam cell formation, influence on cholesterol metabolism, and enhancement of platelet reactivity. Lowering plasma TMAO levels through the rational use of traditional Chinese medicine, dietary management, vitamins, and probiotics can prevent and treat IS.

Future of Endovascular and Surgical Treatments of Atherosclerotic Intracranial Stenosis

Intracranial atherosclerotic disease and resultant intracranial stenosis is a global leading cause of stroke, and poses an ongoing treatment challenge. Among patients with intracranial stenosis, those with hemodynamic compromise are at high risk for recurrent stroke despite medical therapy and risk factor modification. Revascularization of the hypoperfused territory is the most plausible treatment strategy for these high-risk patients, yet surgical and endovascular therapies have not yet shown to be sufficiently safe and effective in randomized controlled trials. Advances in diagnostic and therapeutic technologies have led to a resurgence of interest in surgical and endovascular treatment strategies, with a growing body of evidence to support their further evaluation in the treatment of select patient populations. This review outlines the current and emerging endovascular and surgical treatments and highlights promising future management strategies.

Optimal Medical Management of Atherosclerotic Intracranial Stenosis

Reducing the high risk of recurrent stroke in patients with symptomatic intracranial atherosclerotic stenosis (sICAS) has proven to be challenging, but aggressive medical management, with intensive risk factor control and antithrombotic therapy, has been shown to be beneficial. High-intensity statins are recommended for patients with atherosclerotic stroke, including sICAS. Ezetimibe and PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitors are beneficial for those who fail to reach low-density lipoprotein targets or those with statin intolerance. The treatment target for sICAS is low-density lipoprotein <70 mg/dL. In neurologically stable patients, blood pressure should be treated to goal <140/90 mm Hg with the use of thiazide diuretics, angiotensin-converting enzyme inhibitors, or angiotensin II receptor blockers preferentially. For those with diabetes, treat to goal hemoglobin A1C ≤7% for most patients through combination of diet, insulin, and hypoglycemic drugs. Some degree of physical activity (eg, walking, stationary biking with arms or legs, etc) should be encouraged in all patients with sICAS who are not severely disabled. A minimum of 10 minutes of moderate-intensity aerobic activity 4 times a week is recommended for patients who are capable of exercise. For all patients with severe sICAS (70%-99% stenosis), dual antiplatelet therapy for up to 90 days followed by single antiplatelet agent is recommended.

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.

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.

Different patterns of multiple acute infarctions and long-term prognosis in minor posterior circulation stroke

OBJECTIVES

Different classification of multiple acute infarctions (MAIs) existed in minor posterior circulation stroke (PCS). We aimed to explore the association between different patterns of MAIs and long-term prognosis in minor PCS.

MATERIALS AND METHODS

We derived data from Chinese Intracranial Atherosclerosis (CICAS) study. We analyzed the clinical features and outcomes in MAIs among anterior circulation stroke (ACS) and PCS. The patterns of MAIs in PCS were further classified into multiple infarcts, multilevel infarcts, or multiterritorial infarcts. The long-term prognosis included ischemic events recurrence and poor functional outcome (modified Rankin Scale, mRS=2-6) in 1 year. Multivariable Cox and logistic regression were adopted respectively to evaluate the correlation of different patterns of MAIs with recurrence and poor functional outcome.

RESULTS

We totally enrolled 802 patients with minor stroke in CICAS study, including 484 ACS and 318 PCS. In univariate analysis, MAIs were significantly associated with recurrence in ACS (P<0.01), but were significantly correlated with poor functional outcome in PCS (P=0.044). Among the PCS patients, there were 90 patients with multiple infarcts, 32 patients with multilevel infarcts and 36 patients with multiterritorial infarcts. Multivariable Cox regression showed that multiterritorial infarcts were independently associated with ischemic events recurrence (HR, 3.083; 95 % CI, 1.078-8.813). In multivariable logistic regression, significant correlation with poor functional outcome in 1 year was revealed in multilevel infarcts (OR, 2.788; 95 % CI, 1.144-6.797).

CONCLUSIONS

Different patterns of MAIs provide different predictive performances for PCS prognosis. It is imperative to perform more detailed image interpretation of MAIs in PCS.

The Predictive Value of Essen and SPI-II on the Risk of 5-Year Recurrence in Chinese Patients with Acute Ischemic Stroke

Background

The risk prediction score for stroke recurrence is an important tool for stratifying patients based on the risk of cerebrovascular events and selecting potential preventive treatments.

Objective

The study aimed to validate the Essen Stroke Risk Score (ESRS) and Stroke Prognosis Instrument II (SPI-II) for predicting long-term risk of stroke recurrence and combined vascular events in Chinese patients with acute ischemic stroke (AIS).

Methods

A total of 876 consecutive patients with non-atrial fibrillation AIS were recruited. The Kaplan-Meier (KM) method was used to estimate the cumulative incidence of stroke recurrence and combined vascular events in different subgroups stratified by the ESRS and SPI-II scores. The area under the receiver operating characteristic curve (AUC) was calculated to evaluate the predictive value of the two scores for stroke recurrence and combined vascular events.

Results

The KM estimate for 5-year cumulative incidence of stroke recurrence and combined vascular events was 28.7% (95% confidence interval [CI], 25.4-32.0) and 35.6% (95% CI, 32.3-38.9), respectively, in Chinese AIS patients. The risk of stroke recurrence and combined vascular events were increased significantly with increasing ESRS and SPI-II scores. The ESRS and SPI-II scores had similar predictive accuracy for stroke recurrence (AUC 0.57 [95% CI 0.52-0.64] vs 0.59 [95% CI 0.55-0.64]) and combined vascular events (AUC 0.59 [95% CI 0.55-0.63] vs 0.62 [95% CI 0.58-0.66]) at 5 years.

Conclusion

In Chinese patients with AIS, both ESRS and SPI-II scores were able to stratify the risk of 5-year recurrent stroke and combined vascular events. The predictive power of the two scores were modest and a prediction model suitable for Chinese IS populations is needed.

Association between vertebrobasilar artery geometry and vertebrobasilar stenosis, recurrence, and death in posterior circulation stroke and transient ischemic attack

BACKGROUND

Intracranial atherosclerosis is one of the primary causes of posterior circulation stroke and transient ischemic attack (TIA), particularly in people of South and East Asian heritage. Focal vessel geometry may play a role in atherosclerosis progression. Thus, we investigated the relevance of vertebrobasilar artery (VBA) geometry and vertebrobasilar atherosclerotic stenosis, recurrence, and death in posterior circulation stroke and TIA.

METHODS

Four hundred and twenty patients with posterior circulation ischemic stroke or TIA were included. The VBA geometric features, comprising the geometric configurations (Tuning fork, Walking, Lambda, and No confluence), vascular bends (multi-bending and oligo-bending), and VBA stenosis degrees, were defined based on computed tomography angiography (CTA) images. Recurrence of stroke or TIA and death were assessed through a 1-year follow-up. Additionally, the relationship between VBA geometric features, VBA stenosis, and prognosis were analyzed.

RESULTS

Walking type and vascular multi-bending showed significant associations with more severe VBA stenosis and distribution, and these were also more frequently observed in patients with large-artery atherosclerosis (LAA) stroke (all P < 0.05). Sixty-four patients exhibited recurrent stroke or TIA, and 31 died during the 1-year follow-up. In the binary logistic regression analysis, Walking type (P = 0.018), Lambda type (P = 0.021), and multi-bending type (P = 0.004) were found to be independently associated with stroke recurrence, while No confluence type was independently associated with death (P = 0.010).

CONCLUSIONS

The geometric characteristics of the VBA are associated with vertebrobasilar stenosis, LAA stroke, 1-year recurrence, and death in posterior circulation stroke and TIA. VBA geometry may be used to stratify the risk of stroke and TIA in the posterior circulation.

Asymmetry of Lacunae between Brain Hemispheres Is Associated with Atherosclerotic Occlusions of Middle Cerebral Artery

Cerebral small vessel disease (CSVD) commonly coexists with intracranial atherosclerotic stenosis (ICAS). Previous studies have tried to evaluate the relationship between ICAS and CSVD; however, they have yielded varied conclusions. Furthermore, the methodology of these studies is not very rigorous, as they have evaluated the association between ICAS and CSVD of bilateral hemispheres rather than the affected hemisphere. Unilateral middle cerebral artery atherosclerotic occlusion (uni-MCAO) is a favorable model to solve this problem.

MATERIAL AND METHODS

Patients with uni-MCAO were retrospectively observed. Imaging characteristics, including lacunae, white matter hyperintensities (WMH), enlarged perivascular spaces (EPVS), and cerebral microbleeds (CMBs), were compared between the hemisphere ipsilateral to the MCAO and the contralateral hemisphere.

RESULTS

A total of 219 patients (median age 57 years; 156 males) were enrolled. Compared with the contralateral side, increased quality of lacunae (median, IQR, 0, 2 vs. 0, 1; p < 0.001) and elevated CSVD score (median, IQR, 0, 1 vs. 0, 1; p = 0.004) were found in the occluded hemisphere. No significant differences were shown for WMH, EPVS, and CMBs.

CONCLUSIONS

Uni-MCAO has a higher prevalence of lacunae in the ipsilateral hemisphere. However, no interhemispheric differences in WMH, EPVS, or CMBs were found.

Large Vessel Occlusion Stroke due to Intracranial Atherosclerotic Disease: Identification, Medical and Interventional Treatment, and Outcomes

Large vessel occlusion stroke due to underlying intracranial atherosclerotic disease (ICAD-LVO) is prevalent in 10 to 30% of LVOs depending on patient factors such as vascular risk factors, race and ethnicity, and age. Patients with ICAD-LVO derive similar functional outcome benefit from endovascular thrombectomy as other mechanisms of LVO, but up to half of ICAD-LVO patients reocclude after revascularization. Therefore, early identification and treatment planning for ICAD-LVO are important given the unique considerations before, during, and after endovascular thrombectomy. In this review of ICAD-LVO, we propose a multistep approach to ICAD-LVO identification, pretreatment and endovascular thrombectomy considerations, adjunctive medications, and medical management. There have been no large-scale randomized controlled trials dedicated to studying ICAD-LVO, therefore this review focuses on observational studies.

Borderzone Infarcts and Recurrent Cerebrovascular Events in Symptomatic Intracranial Arterial Stenosis: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

Intracranial arterial stenosis (ICAS)-related stroke occurs due to three primary mechanisms with distinct infarct patterns: (1) borderzone infarcts (BZI) due to impaired distal perfusion, (2) territorial infarcts due to distal plaque/thrombus embolization, and (3) plaque progression occluding perforators. The objective of the systematic review is to determine whether BZI secondary to ICAS is associated with a higher risk of recurrent stroke or neurological deterioration.

METHODS

As part of this registered systematic review (CRD42021265230), a comprehensive search was performed to identify relevant papers and conference abstracts (with ≥20 patients) reporting initial infarct patterns and recurrence rates in patients with symptomatic ICAS. Subgroup analyses were performed for studies including any BZI versus isolated BZI and those excluding posterior circulation stroke. The study outcome included neurological deterioration or recurrent stroke during follow-up. For all outcome events, corresponding risk ratios (RRs) and 95% confidence intervals (95% CI) were calculated.

RESULTS

A literature search yielded 4,478 records with 32 selected during the title/abstract triage for full text; 11 met inclusion criteria and 8 studies were included in the analysis (n=1,219 patients; 341 with BZI). The meta-analysis demonstrated that the RR of outcome in the BZI group compared to the no BZI group was 2.10 (95% CI 1.52-2.90). Limiting the analysis to studies including any BZI, the RR was 2.10 (95% CI 1.38-3.18). For isolated BZI, RR was 2.59 (95% CI 1.24-5.41). RR was 2.96 (95% CI 1.71-5.12) for studies only including anterior circulation stroke patients.

CONCLUSION

This systematic review and meta-analysis suggests that the presence of BZI secondary to ICAS may be an imaging biomarker that predicts neurological deterioration and/or stroke recurrence.

Recurrence risk in symptomatic intracranial stenosis treated medically in the real world

BACKGROUND

The risk of early recurrence in medically treated patients with intracranial atherosclerotic stenosis (ICAS) may differ in clinical trials versus real-world settings. Delayed enrollment may contribute to lower event rates in ICAS trials. We aim to determine the 30-day recurrence risk in a real-world setting of symptomatic ICAS.

METHODS

We used a comprehensive stroke center stroke registry to identify hospitalized patients with acute ischemic stroke or TIA due to symptomatic 50-99% ICAS. The outcome was recurrent stroke within 30 days. We used adjusted Cox regression models to identify factors associated with increased recurrence risk. We also performed a comparison of 30-day recurrent stroke rates in real world cohorts and clinical trials.

RESULTS

Among 131 hospitalizations with symptomatic 50-99% ICAS over 3 years, 80 hospitalizations of 74 patients (mean age 71.6 years, 55.41% men) met the inclusion criteria. Over 30 days, 20.6 % had recurrent stroke; 61.5% (8/13) occurred within first 7 days. The risk was higher in patients not receiving dual antiplatelet therapy (HR 3.92 95% CI 1.30-11.84, p = 0.015) and hypoperfusion mismatch volume >3.5 mL at a T max>6 s threshold (HR 6.55 95% CI 1.60-26.88, p < 0.001). The recurrence risk was similar to another real world ICAD cohort (20.2%), and higher than that seen in clinical trials (2.2%-5.7%), even in those treated with maximal medical treatment or meeting inclusion criteria for trials.

CONCLUSIONS

In patients with symptomatic ICAS, the real-world recurrence of ischemic events is higher than that seen in clinical trials, even in subgroups receiving the same pharmacological treatment strategies.

Association between basilar artery stenosis features, vertebral artery stenosis and perforator stroke after stenting

BACKGROUND AND PURPOSE

We investigated the relationship between basilar artery (BA) atherosclerotic stenosis features and vertebral artery (VA) stenosis and explored whether BA stenosis features are associated with perforator stroke after stenting.

METHODS

Patients with BA stenosis who underwent HRMRI and DSA were recruited. Patients were divided into proximal BA stenosis and middle-or-distal BA stenosis groups, and then subgroup analyses were performed based on whether they had VA stenosis. BA plaque features were evaluated by HRMRI. Artery stenosis was measured by DSA. The incidence of perforator stroke after BA stenting was recorded, and the potential association between BA stenosis features and perforator stroke was analyzed.

RESULTS

One hundred and seventy-four patients were consecutively enrolled. Patients with proximal BA stenosis had a higher proportion of severe stenosis than those with middle-or-distal BA stenosis (P = 0.027). In the subgroup analysis, this difference mainly existed in patients complicated with VA stenosis (P = 0.023). Patients with proximal BA stenosis had a higher proportion of strong plaque enhancement than those with middle-or-distal BA stenosis (P < 0.001), especially in those with vertebrobasilar junction (VBJ) stenosis (P < 0.001). Perforator stroke after BA stenting occurred in five patients, of whom four had lateral wall BA plaques, four had plaque enhancement and four had proximal BA stenosis.

CONCLUSION

Patients with proximal BA stenosis had a higher proportion of severe stenosis and strong plaque enhancement, particularly in patients complicated with VA stenosis and VBJ stenosis. Perforator stroke after BA stenting may be related to distribution, burden and characteristics of BA lesions.

Necessity and timing of angioplasty in acute large-vessel occlusion strokes due to intracranial atherosclerotic disease: A cohort analysis with data from the angel-ACT registry

Background

The effects of angioplasty on intracranial atherosclerotic disease (ICAD)-related acute large-vessel occlusion stroke (LVOS) are unknown. We analyzed the efficacy and safety of angioplasty or stenting for ICAD-related LVOS and the optimal treatment duration.

Methods

Patients with ICAD-related LVOS from a prospective cohort of the Endovascular Treatment Key Technique and Emergency Work Flow Improvement of Acute Ischemia Stroke registry were classified as follows: the early intraprocedural angioplasty and/or stenting (EAS) group was defined as the strategy using angioplasty or stenting without mechanical thrombectomy (MT) or one attempt of MT; the non-angioplasty and/or stenting (NAS) group, MT procedure without any angioplasty; and the late intraprocedural angioplasty and/or stenting (LAS) group, using same angioplasty techniques following two or more passes of MT. The primary endpoint was the modified Rankin Scale (mRS) score at 90 days. Other efficacy outcomes included mRS scores 0–1, mRS 0–2, and successful recanalization. Death within 90 days, and symptomatic ICH were safety endpoints. We use propensity score method to diminish the effect of treatment-selection bias. The odds ratio of recanalization rate and mRS score among EAS, NAS, and LAS groups were examined by unadjusted and adjusted logistic regression analysis among unweighted samples and inverse probability of treatment weighting (IPTW) samples.

Results

We divided 475 cases into three groups. Functional outcomes at 90 days were better in the EAS group than in the NAS and LAS groups. The proportion of mRS 0–1, mRS 0–2, and successful recanalization cases were the highest in the EAS group. However, after IPTW, mortality rate among the three groups were similar (EAS vs. NAS vs. LAS: 19.0 vs. 18.1 vs. 18.7%, p = 0.98) as well as symptomatic intracranial hemorrhage within 24 h however, mortality rate and symptomatic intracranial hemorrhage among the three groups were similar. Logistic regression analysis in unweighted samples and IPTW samples both showed that EAS group had better outcomes. IPTW-adjusted logistic regression analysis demonstrated that the EAS group had better outcomes (mRS 0–1) than the NAS group (adjusted odds ratio [aOR], 0.55; 95% confidence interval [CI]: 0.34–0.88, p = 0.01) and LAS (aOR, 0.39; 95% CI: 0.22–0.68, p = 0.001).

Conclusions

Angioplasty and/or stenting should be performed at an early stage for ICAD-related acute LVOS.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03370939.

Functional evaluation of intracranial atherosclerotic stenosis by pressure ratio measurements

Background

Fractional flow reserve is widely used for the functional evaluation of coronary artery stenosis. Some studies have similarly used the translesional pressure ratio measurements for the functional evaluation of intracranial atherosclerotic stenosis. In this paper, we aimed to investigate the relationship between pressure ratio and cerebral tissue perfusion by MR perfusion imaging and provided a non-invasive method for evaluating the functional significance of intracranial atherosclerotic stenosis.

Methods

A total of 18 consecutive patients with intracranial atherosclerotic stenosis patients including 19 stenotic vessels were recruited. The pressure was measured using a pressure guidewire, the pressure ratio before and after the endovascular intervention was calculated and compared with the severity of diameter stenosis and perfusion-derived MR (the time to maximum tissure residue function (Tmax)). Moreover, the DSA-derived pressure ratio was computed using a novel computational fluid dynamics-based model, termed CFD-PR, and was compared with the actual pressure ratio to assess its diagnostic accuracy.

Results

The pressure ratio increased after percutaneous transluminal angioplasty or stenting, while the correlation between pressure ratio and diameter stenosis was not significant. The pressure ratio was negatively correlated with Tmax (r = -0.73, P < 0.01), and a 95% confidence interval for the cutoff value of pressure ratio = 0.67 (95% confidence interval: 0.58-0.76) was suggested. There was a good correlation (mean = 0.02, Spearman's correlation coefficient r = 0.908, P < 0.001) and agreement (limits of agreement: -0.157 to 0.196, P = 0.954) between CFD-PR and the actual pressure ratio.

Conclusions

This exploratory study indicates the pressure ratio may correlate with the perfusion status. The pressure ratio can be calculated through a non-invasive method using a computational fluid dynamics-based method.

Borderzone infarction and recurrent stroke in intracranial atherosclerosis

BACKGROUND

Intracranial stenosis (ICAS) is a common cause of stroke worldwide and patients with symptomatic ICAS exhibit a high rate of recurrence, particularly in the early period after the initial event. In this study, we aimed to study the association between borderzone infarct and recurrent ischemic stroke in patients hospitalized with symptomatic ICAS.

METHODS

This is a retrospective single center study that included patients hospitalized with acute ischemic stroke in the setting of intracranial stenosis (50% or more and an acute ischemic stroke in the territory supplied by the stenosed artery) over a 32-month period. We excluded patients who did not receive a brain MRI or did not have an infarct on brain imaging. The primary predictor is infarct pattern (any borderzone vs. no borderzone infarct) and the primary outcome was recurrent cerebrovascular events (RCVE) within 90 days. We used unadjusted, and age and sex adjusted logistic regression models to determine associations between infarct pattern and RCVE at 90-days.

RESULTS

Among 99 patients who met the inclusion criteria (4 tandem), the mean age was 70.1 ± 11.2 years and 41.4% were women; 43 had borderzone infarcts and 19 had RCVE. In adjusted binary logistic regression analysis, borderzone infarct was associated with increased risk of RCVE (adjusted OR 4.00 95% CI 1.33-11.99, p=0.013). The association between borderzone infarction and RCVE was not different among anterior circulation ICAD (adjusted HR 2.85 95% CI 0.64-12.76, p=0.172) vs. posterior circulation ICAD (adjusted HR 6.69 95% CI 1.06-42.11, p=0.043), p-value for interaction = 0.592.

CONCLUSION

In real world post-SAMMPRIS medically treated patients with ICAD, the borderzone infarct pattern was associated with 90-day RCVE. Borderzone infarcts are likely a surrogate marker of impaired distal blood flow, highlighting the importance of targeting stroke mechanisms and developing alternative treatment strategies for high-risk cohorts.

The CASSISS Randomized Clinical Trial

The CASSISS trial (China Angioplasty & Stenting for Symptomatic Intracranial Severe Stenosis), recently published in JAMA, is the most recent of several randomized controlled trials that have failed to show a benefit of percutaneous angioplasty and stenting over medical therapy for the prevention of stroke due to intracranial atherosclerotic stenosis. Current practice guidelines recommended that percutaneous angioplasty and stenting should not be performed routinely as a treatment for stroke prevention in patients with intracranial atherosclerotic stenosis. The CASSISS trial reinforces those recommendations and will not change practice, but it may provide some important lessons for future trial design.

Association of periprocedural perfusion non-improvement with recurrent stroke after endovascular treatment for Intracranial Atherosclerotic Stenosis

Background

Predictors of recurrent stroke after endovascular treatment for symptomatic intracranial atherosclerotic stenosis (ICAS) remain uncertain.

Objectives

Among baseline characteristics, lesion features, and cerebral perfusion changes, we try to explore which factors are associated with the risk of recurrent stroke in symptomatic ICAS after endovascular treatment.

Design

Consecutive patients with symptomatic ICAS of 70-99% receiving endovascular treatment were enrolled. All patients underwent whole-brain computer tomography perfusion (CTP) within 3 days before and 3 days after the endovascular treatment. Baseline characteristics, lesion features, and cerebral perfusion changes were collected.

Methods

Cerebral perfusion changes were evaluated with RAPID software and calculated as preprocedural cerebral blood flow (CBF) < 30%, time to maximum of the residue function (Tmax) > 6 s, and Tmax > 4 s volumes minus postprocedural. Cerebral perfusion changes were divided into periprocedural perfusion improvement (>0 ml) and non-improvement (⩽ 0 ml). Recurrent stroke within 180 days was collected. The Cox proportional hazards analysis analyses were performed to evaluate factors associated with recurrent stroke.

Results

From March 2021 to December 2021, 107 patients with symptomatic ICAS were enrolled. Of the 107 enrolled patients, 30 (28.0%) patients underwent balloon angioplasty alone and 77 patients (72.0%) underwent stenting. The perioperative complications occurred in three patients. Among CBF < 30%, Tmax > 6 s, and Tmax > 4 s volumes, Tmax > 4 s volume was available to evaluate cerebral perfusion changes. Periprocedural perfusion improvement was found in 77 patients (72.0%) and non-improvement in 30 patients (28.0%). Nine patients (8.4%) suffered from recurrent stroke in 180-day follow-up. In Cox proportional hazards analysis adjusted for age and sex, perfusion non-improvement was associated with recurrent stroke [hazards ratio (HR): 4.472; 95% CI: 1.069-18.718; p = 0.040].

Conclusion

In patients with symptomatic ICAS treated with endovascular treatment, recurrent stroke may be related to periprocedural cerebral perfusion non-improvement.

Registration

http://www.chictr.org.cn. Unique identifier: ChiCTR2100052925.

Wall characteristics of atherosclerotic middle cerebral arteries in patients with single or multiple infarcts: A high-resolution MRI Study

Background and purpose

Understanding the stroke mechanism of middle cerebral artery (MCA) atherosclerosis may inform secondary prevention. The aim of this study was to explore the relationship between vascular wall characteristics and infarction patterns using high-resolution magnetic resonance imaging (HRMRI) and diffusion-weighted imaging (DWI).

Methods

From November 2018 to March 2021, patients with acute ischemic stroke due to MCA atherosclerotic disease were retrospectively analyzed. The wall characteristics of atherosclerotic MCA, including conventional characteristics and histogram-defined characteristics, were evaluated using HRMRI. Patients were divided into single-infarction and multiple-infarction groups based on DWI, and wall characteristics were compared between the two groups.

Results

Of 92 patients with MCA plaques, 59 patients (64.1%) had multiple infarcts, and 33 (35.9%) had single infarcts. The histogram-defined characteristics showed no differences between the single-infarction and multiple-infarction groups (P&gt;0.05). Plaque burden, degree of stenosis, and prevalence of intraplaque hemorrhage (IPH) were significantly greater in the multiple-infarction group than in the single-infarction group (plaque burden: P = 0.001; degree of stenosis: P = 0.010; IPH: P = 0.019). Multivariate analysis showed that plaque burden (odds ratio: 1.136; 95% confidence interval: 1.054–1.224, P = 0.001) and IPH (odds ratio: 5.248; 95% confidence interval: 1.573–17.512, P = 0.007) were independent predictors for multiple infarction.

Conclusion

IPH and plaque burden are independently associated with multiple infarcts. HRMRI may provide new insight into the mechanisms underlying the different MCA infarction patterns.

Diffusion-weighted imaging-based radiomics for predicting 1-year ischemic stroke recurrence

Purpose

To investigate radiomics based on DWI (diffusion-weighted imaging) for predicting 1-year ischemic stroke recurrence.

Methods

A total of 1,580 ischemic stroke patients were enrolled in this retrospective study conducted from January 2018 to April 2021. Demographic and clinical characteristics were compared between recurrence and non-recurrence groups. On DWI, lesions were segmented using a 2D U-Net automatic segmentation network. Further, radiomics feature extraction was done using the segmented mask matrix on DWI and the corresponding ADC map. Additionally, radiomics features were extracted. The study participants were divided into a training cohort (n = 157, 57 recurrence patients, and 100 non-recurrence patients) and a test cohort (n = 846, 28 recurrence patients, 818 non-recurrence patients). A sparse representation feature selection model was performed to select features. Further classification was accomplished using a recurrent neural network (RNN). The area under the receiver operating characteristic curve values was obtained for model performance.

Results

A total of 1,003 ischemic stroke patients (682 men and 321 women; mean age: 65.90 ± 12.44 years) were included in the final analysis. About 85 patients (8.5%) recurred in 1 year, and patients in the recurrence group were older than the non-recurrence group (P = 0.003). The stroke subtype was significantly different between recurrence and non-recurrence groups, and cardioembolic stroke (11.3%) and large artery atherosclerosis patients (10.3%) showed a higher recurrence percentage (P = 0.005). Secondary prevention after discharge (statins, antiplatelets, and anticoagulants) was found significantly different between the two groups (P = 0.004). The area under the curve (AUC) of clinical-based model and radiomics-based model were 0.675 (95% CI: 0.643–0.707) and 0.779 (95% CI: 0.750–0.807), respectively. With an AUC of 0.847 (95% CI: 0.821–0.870), the model that combined clinical and radiomic characteristics performed better.

Conclusion

DWI-based radiomics could help to predict 1-year ischemic stroke recurrence.

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.

Advances in Recurrent Stroke Prevention: Focus on Antithrombotic Therapies

The past decade has seen significant advances in stroke prevention. These advances include new antithrombotic agents, new options for dyslipidemia treatment, and novel techniques for surgical stroke prevention. In addition, there is greater recognition of the benefits of multifaceted interventions, including the role of physical activity and dietary modification. Despite these advances, the aging of the population and the high prevalence of key vascular risk factors pose challenges to reducing the burden of stroke. Using a cause-based framework, current approaches to prevention of cardioembolic, cryptogenic, atherosclerotic, and small vessel disease stroke are outlined in this paper. Special emphasis is given to recent trials of antithrombotic agents, including studies that have tested combination treatments and responses according to genetic factors.

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.

Lipid Levels and Short-Term Risk of Recurrent Brain Infarcts in Symptomatic Intracranial Stenosis

OBJECTIVES

Hyperlipidemia is a strong risk factor for intracranial atherosclerotic disease (ICAD) and clinical stroke recurrence. We explored the effect of serum lipid levels on subclinical infarct recurrence in the Mechanisms of earlY Recurrence in Intracranial Atherosclerotic Disease (MYRIAD) study.

MATERIALS AND METHODS

We included enrolled MYRIAD patients with lipid measurements and brain MRI at baseline and brain MRI at 6-8 weeks. Infarct recurrence was defined as new infarcts in the territory of the symptomatic artery on brain MRI at 6-8 weeks compared to baseline brain MRI. We assessed the association between baseline total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG) levels and recurrent infarct at 6-8 weeks using multivariable logistic regression.

RESULTS

Among 74 patients (mean age 64.2±12.9 years, 59.5% were white, 60.8% men), 20 (27.0%) had new or recurrent infarcts. Mean HDL-C (37.2 vs. 43.9 mg/dL, P=0.037) was lower and TG (113.5 vs. 91.3 mg/dL, P=0.008) was higher while TC (199.8 vs. 174.3 mg/dL, P=0.061) and LDL-C (124.3 vs. 101.2 mg/dL, P=0.053) were nominally higher among those with recurrent infarcts than those without. LDL-C (adj. OR 1.022, 95% CI 1.004-1.040, P=0.015) and TG (adj. OR 1.009, 95% CI 1.001-1.016, P=0.021) were predictors of recurrent infarct at 6-8 weeks adjusting for other clinical and imaging factors.

CONCLUSIONS

Baseline cholesterol markers can predict early infarct recurrence in patients with symptomatic ICAD. More intensive and rapid lipid lowering drugs may be required to reduce risk of early recurrence.