A Deep Learning Approach to Predict Recanalization First-Pass Effect following Mechanical Thrombectomy in Patients with Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Following endovascular thrombectomy in patients with large-vessel occlusion stroke, successful recanalization from 1 attempt, known as the first-pass effect, has correlated favorably with long-term outcomes. Pretreatment imaging may contain information that can be used to predict the first-pass effect. Recently, applications of machine learning models have shown promising results in predicting recanalization outcomes, albeit requiring manual segmentation. In this study, we sought to construct completely automated methods using deep learning to predict the first-pass effect from pretreatment CT and MR imaging. MATERIALS AND METHODS: Our models were developed and evaluated using a cohort of 326 patients who underwent endovascular thrombectomy at UCLA Ronald Reagan Medical Center from 2014 to 2021. We designed a hybrid transformer model with nonlocal and cross-attention modules to predict the first-pass effect on MR imaging and CT series. RESULTS: The proposed method achieved a mean 0.8506 (SD, 0.0712) for cross-validation receiver operating characteristic area under the curve (ROC-AUC) on MR imaging and 0.8719 (SD, 0.0831) for cross-validation ROC-AUC on CT. When evaluated on the prospective test sets, our proposed model achieved a mean ROC-AUC of 0.7967 (SD, 0.0335) with a mean sensitivity of 0.7286 (SD, 0.1849) and specificity of 0.8462 (SD, 0.1216) for MR imaging and a mean ROC-AUC of 0.8051 (SD, 0.0377) with a mean sensitivity of 0.8615 (SD, 0.1131) and specificity 0.7500 (SD, 0.1054) for CT, respectively, representing the first classification of the first-pass effect from MR imaging alone and the first automated first-pass effect classification method in CT. CONCLUSIONS: Results illustrate that both nonperfusion MR imaging and CT from admission contain signals that can predict a successful first-pass effect following endovascular thrombectomy using our deep learning methods without requiring time-intensive manual segmentation.

Water content for clot composition prediction in acute ischemic stroke.

BACKGROUND: Mechanical thrombectomy (MT) has become the gold standard care for treating acute ischemic stroke (AIS) due to large vessel occlusion. Emerging evidence suggests that understanding the composition of clots prior to intervention could be useful for the selection of neuroendovascular techniques, potentially improving the efficacy of treatments. However, current imaging modalities lack the ability to distinguish clot composition accurately and reliably. Since water content can influence signal intensity on CT and MRI scans, its assessment may provide indirect clues about clot composition. This study aimed to elucidate the correlation between water content and clot composition using human clots retrieved from stroke patients and experimentally generated ovine clots. MATERIALS AND METHODS: This study involved an analysis of ten clots retrieved from patients with AIS undergoing MT. Additionally, we created ten red blood cells (RBC)-rich and ten fibrin-rich ovine blood clots, which were placed in a human intracranial vascular model under realistic flow conditions. The water content and compositions of these clots were evaluated, and linear regression analyses were performed to determine the relationship between clot composition and water content. RESULTS: The regression analysis in human stroke clots revealed a significant negative association between RBC concentration and water content. We also observed a positive correlation between water content and both fibrin and platelets in ovine blood clots. Conclusion.

Circadian variation in stroke onset: Differences between ischemic and hemorrhagic stroke and weekdays versus weekends.

OBJECTIVES: To delineate diurnal variation onset distinguishing ischemic from hemorrhagic stroke, wake from sleep onset, and weekdays from weekends/holidays. MATERIALS AND METHODS: We analyzed patients enrolled in the FAST-MAG trial of field-initiated neuroprotective agent in patients with hyperacute stroke within 2h of symptoms onset. Stroke onset times were analyzed in 1h, 4h, and 12h time blocks throughout the 24h day-night cycle. Patient demographic, clinical features, stroke severity, and prehospital workflow were evaluated for association with onset times. RESULTS: Among 1615 acute cerebrovascular disease patients, final diagnoses were acute cerebral ischemia in 76.5% and Intracerebral hemorrhage in 23.5%. Considering all acute cerebrovascular disease patients, frequency of wake onset times showed a bimodal pattern, with peaks on onsets at 09:00-13:59 and 17:00-18:59 and early morning (00:00-05:59) onset in only 3.8%. Circadian rhythmicity differed among stroke subtypes: in acute cerebral ischemia, a single broad plateau of elevated incidences was seen from 10:00-21:59; in Intracerebral hemorrhage, bimodal peaks occurred at 09:00 and 19:00. The ratio of Intracerebral hemorrhage to acute cerebral ischemia occurrence was highest in early morning, 02:00-06:59. Marked weekday vs weekends pattern variation was noted for acute cerebral ischemia, with a broad plateau between 09:00 and 21:59 on weekdays but a unimodal peak at 14:00-15:59 on weekends. CONCLUSIONS: Wake onset of acute cerebrovascular disease showed a marked circadian variation, with distinctive patterns of a broad elevated plateau among acute cerebral ischemia patients; a bimodal peak among intracerebral hemorrhage patients; and a weekend change in acute cerebral ischemia pattern to a unimodal peak.

Heterogeneity between proximal and distal aspects of occlusive thrombi on pretreatment imaging in acute ischemic stroke.

BACKGROUND: The potential heterogeneity in occlusive thrombi caused by in situ propagation by secondary thrombosis after embolic occlusion could obscure the characteristics of original thrombi, preventing the clarification of a specific thrombus signature for the etiology of ischemic stroke. We aimed to investigate the heterogeneity of occlusive thrombi by pretreatment imaging. METHODS: Among consecutive stroke patients with acute embolic anterior circulation large vessel occlusion treated with thrombectomy, we retrospectively reviewed 104 patients with visible occlusive thrombi on pretreatment non-contrast computed tomography admitted from January 2015 to December 2018. A region of interest was set on the whole thrombus on non-contrast computed tomography under the guidance of computed tomography angiography. The region of interest was divided equally into the proximal and distal segments and the difference in Hounsfield unit densities between the two segments was calculated. RESULTS: Hounsfield unit density in the proximal segment was higher than that in the distal segment (mean difference 4.45; p < 0.001), regardless of stroke subtypes. On multivariate analysis, thrombus length was positively correlated (ß = 0.25; p < 0.001) and time from last-known-well to imaging was inversely correlated (ß = -0.0041; p = 0.002) with the difference in Hounsfield unit densities between the proximal and distal segments. CONCLUSIONS: The difference in density between the proximal and distal segments increased as thrombi became longer and decreased as thrombi became older after embolic occlusion. This time/length-dependent thrombus heterogeneity between the two segments is suggestive of secondary thrombosis initially occurring on the proximal side of the occlusion.

Frequency, Determinants, and Outcomes of Emboli to Distal and New Territories Related to Mechanical Thrombectomy for Acute Ischemic Stroke.

Background and Purpose: Clot fragmentation and distal embolization during endovascular thrombectomy for acute ischemic stroke may produce emboli downstream of the target occlusion or in previously uninvolved territories. Susceptibility-weighted magnetic resonance imaging can identify both emboli to distal territories (EDT) and new territories (ENT) as new susceptibility vessel signs (SVS). Diffusion-weighted imaging (DWI) can identify infarcts in new territories (INT). Methods: We studied consecutive acute ischemic stroke patients undergoing magnetic resonance imaging before and after thrombectomy. Frequency, predictors, and outcomes of EDT and ENT detected on gradient-recalled echo imaging (EDT-SVS and ENT-SVS) and INT detected on DWI (INT-DWI) were analyzed. Results: Among 50 thrombectomy-treated acute ischemic stroke patients meeting study criteria, mean age was 70 (±16) years, 44% were women, and presenting National Institutes of Health Stroke Scale score 15 (interquartile range, 8­19). Overall, 21 of 50 (42%) patients showed periprocedural embolic events, including 10 of 50 (20%) with new EDT-SVS, 10 of 50 (20%) with INT-DWI, and 1 of 50 (2%) with both. No patient showed ENT-SVS. On multivariate analysis, model-selected predictors of EDT-SVS were lower initial diastolic blood pressure (odds ratio, 1.09 [95% CI, 1.02­1.16]), alteplase pretreatment (odds ratio, 5.54 [95% CI, 0.94­32.49]), and atrial fibrillation (odds ratio, 7.38 [95% CI, 1.02­53.32]). Classification tree analysis identified pretreatment target occlusion SVS as an additional predictor. On univariate analysis, INT-DWI was less common with internal carotid artery (5%), intermediate with middle cerebral artery (25%), and highest with vertebrobasilar (57%) target occlusions (P=0.02). EDT-SVS was not associated with imaging/functional outcomes, but INT-DWI was associated with reduced radiological hemorrhagic transformation (0% versus 54%; P<0.01). Conclusions: Among acute ischemic stroke patients treated with thrombectomy, imaging evidence of distal emboli, including EDT-SVS beyond the target occlusion and INT-DWI in novel territories, occur in about 2 in every 5 cases. Predictors of EDT-SVS are pretreatment intravenous fibrinolysis, potentially disrupting thrombus structural integrity; atrial fibrillation, possibly reflecting larger target thrombus burden; lower diastolic blood pressure, suggestive of impaired embolic washout; and pretreatment target occlusion SVS sign, indicating erythrocyte-rich, friable target thrombus.

Effect of a Coordinated Community and Chronic Care Model Team Intervention vs Usual Care on Systolic Blood Pressure in Patients With Stroke or Transient Ischemic Attack: The SUCCEED Randomized Clinical Trial.

Importance: Few stroke survivors meet recommended cardiovascular goals, particularly among racial/ethnic minority populations, such as Black or Hispanic individuals, or socioeconomically disadvantaged populations. Objective: To determine if a chronic care model-based, community health worker (CHW), advanced practice clinician (APC; including nurse practitioners or physician assistants), and physician team intervention improves risk factor control after stroke in a safety-net setting (ie, health care setting where all individuals receive care, regardless of health insurance status or ability to pay). Design, Setting, and Participants: This randomized clinical trial included participants recruited from 5 hospitals serving low-income populations in Los Angeles County, California, as part of the Secondary Stroke Prevention by Uniting Community and Chronic Care Model Teams Early to End Disparities (SUCCEED) clinical trial. Inclusion criteria were age 40 years or older; experience of ischemic or hemorrhagic stroke or transient ischemic attack (TIA) no more than 90 days prior; systolic blood pressure (BP) of 130 mm Hg or greater or 120 to 130 mm Hg with history of hypertension or using hypertensive medications; and English or Spanish language proficiency. The exclusion criterion was inability to consent. Among 887 individuals screened for eligibility, 542 individuals were eligible, and 487 individuals were enrolled and randomized, stratified by stroke type (ischemic or TIA vs hemorrhagic), language (English vs Spanish), and site to usual care vs intervention in a 1:1 fashion. The study was conducted from February 2014 to September 2018, and data were analyzed from October 2018 to November 2020. Interventions: Participants randomized to intervention were offered a multimodal coordinated care intervention, including hypothesized core components (ie, ≥3 APC clinic visits, ≥3 CHW home visits, and Chronic Disease Self-Management Program workshops), and additional telephone visits, protocol-driven risk factor management, culturally and linguistically tailored education materials, and self-management tools. Participants randomized to the control group received usual care, which varied by site but frequently included a free BP monitor, self-management tools, and linguistically tailored information materials. Main Outcomes and Measures: The primary outcome was change in systolic BP at 12 months. Secondary outcomes were non-high density lipoprotein cholesterol, hemoglobin A1c, and C-reactive protein (CRP) levels, body mass index, antithrombotic adherence, physical activity level, diet, and smoking status at 12 months. Potential mediators assessed included access to care, health and stroke literacy, self-efficacy, perceptions of care, and BP monitor use. Results: Among 487 participants included, the mean (SD) age was 57.1 (8.9) years; 317 (65.1%) were men, and 347 participants (71.3%) were Hispanic, 87 participants (18.3%) were Black, and 30 participants (6.3%) were Asian. A total of 246 participants were randomized to usual care, and 241 participants were randomized to the intervention. Mean (SD) systolic BP improved from 143 (17) mm Hg at baseline to 133 (20) mm Hg at 12 months in the intervention group and from 146 (19) mm Hg at baseline to 137 (22) mm Hg at 12 months in the usual care group, with no significant differences in the change between groups. Compared with the control group, participants in the intervention group had greater improvements in self-reported salt intake (difference, 15.4 [95% CI, 4.4 to 26.0]; P = .004) and serum CRP level (difference in log CRP, -0.4 [95% CI, -0.7 to -0.1] mg/dL; P = .003); there were no differences in other secondary outcomes. Although 216 participants (89.6%) in the intervention group received some of the 3 core components, only 35 participants (14.5%) received the intended full dose. Conclusions and Relevance: This randomized clinical trial of a complex multilevel, multimodal intervention did not find vascular risk factor improvements beyond that of usual care; however, further studies may consider testing the SUCCEED intervention with modifications to enhance implementation and participant engagement. Trial Registration: ClinicalTrials.gov Identifier: NCT01763203.

Impact of eloquent motor cortex-tissue reperfusion beyond the traditional thrombolysis in cerebral infarction (TICI) scoring after thrombectomy.

BACKGROUND: Targeted eloquence-based tissue reperfusion within the primary motor cortex may have a differential effect on disability as compared with traditional volume-based (thrombolysis in cerebral infarction, TICI) reperfusion after endovascular thrombectomy (EVT) in the setting of acute ischemic stroke (AIS). METHODS: We explored the impact of eloquent reperfusion (ER) within primary motor cortex (PMC) on clinical outcome (modified Rankin Scale, mRS) in AIS patients undergoing EVT. ER-PMC was defined as presence of flow on final digital subtraction angiography (DSA) within four main cortical branches, supplying the PMC (middle cerebral artery (MCA) - precentral, central, postcentral; anterior cerebral artery (ACA) - medial frontal branch arising from callosomarginal or pericallosal arteries) and graded as absent (0), partial (1), and complete (2). Prospectively collected data from two centers were analyzed. Multivariate analysis was conducted to assess the impact of ER-PMC on 90-day disability (mRS) among patients with anterior circulation occlusion who achieved partial reperfusion (TICI 2a and 2b). RESULTS: Among the 125 patients who met the study criteria, ER-PMC distribution was: absent (0) in 19/125 (15.2%); partial (1) in 52/125 (41.6%), and complete (2) in 54/125 (43.2%). TICI 2b was achieved in 102/125 (81.6%) and ER-PMC was substantially higher in those patients (P<0.001). In multivariate analysis, in addition to age and symptomatic intracranial hemorrhage, ER-PMC had a profound independent impact on 90-day disability (OR 6.10, P=0.001 for ER-PMC 1 vs 0 and OR 9.87, P<0.001 for ER-PMC 2 vs 0), while the extent of total partial reperfusion (TICI 2b vs 2a) was not related to 90-day mRS. CONCLUSIONS: Eloquent PMC-tissue reperfusion is a key determinant of functional outcome, with a greater impact than volume-based (TICI) degree of partial reperfusion alone. PMC-targeted revascularization among patients with partial reperfusion may further diminish post-stroke disability after EVT.

Encephaloduroarteriosynangiosis (EDAS) revascularization for symptomatic intracranial atherosclerotic steno-occlusive (ERSIAS) Phase-II objective performance criterion trial.

BACKGROUND: Intracranial atherosclerotic disease (ICAD) is one of the most challenging stroke etiologies, with frequent recurrences despite optimized medical management. Encephaloduroarteriosynangiosis (EDAS) is an indirect revascularization method that produces extra-cranial collaterals to intracranial vessels. We present the results of a phase-II trial of EDAS in intracranial atherosclerotic disease patients. AIMS: To evaluate the feasibility, safety, and preliminary efficacy of EDAS in intracranial atherosclerotic disease patients. METHODS: ERSIAS was a prospective objective-performance-criterion trial of EDAS plus intensive medical management (IMM) in intracranial atherosclerotic disease (ICAD) patients failing medical treatment. Primary endpoint was any stroke/death within 30-days post-surgery or stroke in the territory of the qualifying artery beyond 30 days. The primary analysis compared event rates through one year with an objective-performance-criterion based on a 10% reduction from the 20% rate in the intensive medical management arm of the stenting versus aggressive medical management for preventing recurrent stroke in intracranial stenosis trial (SAMMPRIS) in patients with poor collaterals. Event rates through two years were compared with propensity-score-matched (PSM) medically treated patients from SAMMPRIS and the carotid occlusion surgery study (COSS). RESULTS: During a median follow-up of 24.5 months, 5 (9.6%) of 52 patients had a primary endpoint event. The primary endpoint rate at one year met the threshold for nonfutility and advancement to phase III (<10%). In the sensitivity analysis, primary endpoint event rate at two years was lower than in PSM controls, 9.6% versus 21.2% (p < 0.07). Overall, 86% of EDAS-plus-intensive medical management patients were functionally independent at last follow-up and 89% demonstrated neovascularization. There were two (3.8%) surgical complications and no intracranial hemorrhages. CONCLUSION: ERSIAS phase II provides evidence of safety and strong signals of efficacy of EDAS-plus-intensive medical management, supporting advancement to a seamless phase-IIb/III trial. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov.NCT01819597.

Efficient Multimodal MRI Evaluation for Endovascular Thrombectomy of Anterior Circulation Large Vessel Occlusion.

BACKGROUND: MRI and CT modalities are both current standard-of-care options for initial imaging in patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO). MR provides greater lesion conspicuity and spatial resolution, but few series have demonstrated multimodal MR may be performed efficiently. METHODS: In a prospective comprehensive stroke center registry, we analyzed all anterior circulation LVO thrombectomy patients between 2012-2017 who: (1) arrived directly by EMS from the field, and (2) had initial NIHSS ≥6. Center imaging policy was multimodal MRI (including DWI/GRE/MRA w/wo PWI) as the initial evaluation in all patients without contraindications, and multimodal CT (including CT with CTA, w/wo CTP) in the remainder. RESULTS: Among 106 EMS-arriving endovascular thrombectomy patients, initial imaging was MRI 62.3%, CT in 37.7%. MRI and CT patients were similar in age (72.5 vs 71.3), severity (NIHSS 16.4 v 18.2), and medical history, though MRI patients had longer onset-to-door times. Overall, door-to-needle (DTN) and door-to-puncture (DTP) times did not differ among MR and CT patients, and were faster for both modalities in 2015-2017 versus 2012-2014. In the 2015-2017 period, for MR-imaged patients, the median DTN 42m (IQR 34-55) surpassed standard (60m) and advanced (45m) national targets and the median DTP 86m (IQR 71-106) surpassed the standard national target (90m). CONCLUSIONS: AIS-LVO patients can be evaluated by multimodal MR imaging with care speeds faster than national recommendations for door-to-needle and door-to-puncture times. With its more sensitive lesion identification and spatial resolution, MRI remains a highly viable primary imaging strategy in acute ischemic stroke patients, though further workflow efficiency improvements are desirable.

Predictors and Functional Outcomes of Fast, Intermediate, and Slow Progression Among Patients With Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: We aimed to delineate the determinants of the initial speed of infarct progression and the association of speed of infarct progression (SIP) with procedural and functional outcomes. METHODS: From a prospectively maintained stroke center registry, consecutive anterior circulation ischemic stroke patients with large artery occlusion, National Institutes of Health Stroke Scale score ≥4, and multimodal vessel, ischemic core, and tissue-at-risk imaging within 24 hours of onset were included. Initial SIP was calculated as ischemic core volume at first imaging divided by the time from stroke onset to imaging. RESULTS: Among the 88 patients, SIP was median 2.2 cc/h (interquartile range, 0-8.7), ranging most widely within the first 6 hours after onset. Faster SIP was positively independently associated with a low collateral score (odds ratio [OR], 3.30 [95% CI, 1.25-10.49]) and arrival by emergency medical services (OR, 3.34 [95% CI, 1.06-10.49]) and negatively associated with prior ischemic stroke (OR, 0.12 [95% CI, 0.03-0.50]) and coronary artery disease (OR, 0.32 [95% CI, 0.10-1.00]). Among the 67 patients who underwent endovascular thrombectomy, slower SIP was associated with a shift to reduced levels of disability at discharge (OR, 3.26 [95% CI, 1.02-10.45]), increased substantial reperfusion by thrombectomy (OR, 8.30 [95% CI, 0.97-70.87]), and reduced radiological hemorrhagic transformation (OR, 0.34 [95% CI, 0.12-0.94]). CONCLUSIONS: Slower SIP is associated with a high collateral score, prior ischemic stroke, and coronary artery disease, supporting roles for both collateral robustness and ischemic preconditioning in fostering tissue resilience to ischemia. Among patients undergoing endovascular thrombectomy, the speed of infarct progression is a major determinant of clinical outcome.

Selective middle cerebral artery occlusion in the rabbit: Technique and characterization with pathologic findings and multimodal MRI.

BACKGROUND: A reliable animal model of ischemic stroke is vital for pre-clinical evaluation of stroke therapies. We describe a reproducible middle cerebral artery (MCA) embolic occlusion in the French Lop rabbit characterized with multimodal MRI and histopathologic tissue analysis. NEW METHOD: Fluoroscopic-guided microcatheter placement was performed in five consecutive subjects with angiographic confirmation of MCA occlusion with autologous clot. Multimodal MRI was obtained prior to occlusion and up to six hours post after which repeat angiography confirmed sustained occlusion. The brain was harvested for histopathologic examination. RESULTS: Angiography confirmed successful MCA catheterization and durable (>6 h) MCA occlusion in all animals. There was increase of ADC volume over time and variable final core volume presumably related to individual variation in collateral flow. FLAIR hyperintensity indicative of cytotoxic edema and parenchymal contrast enhancement reflective of blood brain barrier disruption was observed over time. Tissue staining of the ischemic brain showed edema and structural alterations consistent with infarction. COMPARISON WITH EXISTING METHODS: This study describes a technique of selective catheterization and embolic occlusion of the MCA in the rabbit with MRI characterization of evolution of ischemia in the model. CONCLUSIONS: We demonstrate the feasibility of a rabbit model of embolic MCA occlusion with angiographic documentation. Serial MR imaging demonstrated changes comparable to those observed in human ischemic stroke, confirmed histopathologically.

The Frequency of Substantial Salvageable Penumbra in Thrombectomy-ineligible Patients with Acute Stroke.

BACKGROUND AND PURPOSE: Endovascular therapy (ET) has become the standard of care for selected patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO). However, many LVO or medium vessel occlusion (MVO) patients are ineligible for ET, including some who harbor salvageable tissues. To develop complementary therapies for these patients, it is important to delineate their prevalence, clinical features, and outcomes. METHODS: In a prospectively maintained database, we reviewed consecutive AIS patients between December 2015 and September 2016. Based on the first multimodal computed tomography or magnetic resonance imaging, patients were categorized as having substantial penumbra if perfusion lesion volume (Tmax >6 seconds) exceeded ischemic core volume (relative cerebral blood flow <30% on CT perfusion or apparent diffusion coefficient <620 on diffusion weighted image) by ≥20%. RESULTS: Among 174 consecutive AIS patients presenting within 24 hours of last known well time, 29 (17%) had LVO or MVO and substantial penumbra, but were deemed ET ineligible. Among these patients, mean age was 81 (±13), 45% were female, and median National Institute of Health Stroke Scale score was 11 (interquartile range [IQR]: 5-19). The most common reasons for not pursuing ET were: distal occlusion (28%), mild neurologic deficit (16%), and temporally advanced core injury (16%). Ischemic core volume was 20 mL (±31), penumbral volume was 54 mL (±63), and mismatch ratio median was 5.6 (IQR: 2-infinite). Severe disability or death at discharge (modified Rankin scale: 4-6) occurred in 72% of the patients. CONCLUSION: Even in the modern stent retriever era, 1 in 6 AIS patients presents with substantial penumbra judged not appropriate for ET. This population may benefit from the development of alternative therapies, including collateral enhancement, neuroprotection, and thrombectomy devices deployable in distal arteries.

Ischemic Stroke in a Patient with Parry-Romberg Syndrome.

OBJECTIVE: This study aimed to discuss a case of a patient with a known diagnosis of Parry-Romberg syndrome (PRS) presenting with ischemic stroke, the second such reported case. BACKGROUND: PRS is a rare genetic disorder with progressive hemifacial atrophy, which usually presents within the first 2 decades of life. Neurologic manifestations include trigeminal neuralgia with associated deafness, hemifacial pain with associated migraine headaches, seizures, movement disorders, and neuropsychiatric symptoms. Many patients have elevated antinuclear antibody (ANA) titers. However, stroke is uncommon. CASE DESCRIPTION: A 34-year-old right-handed woman, diagnosed with PRS at age 15, presented with right-sided weakness on waking up. Brain magnetic resonance imaging revealed a small infarct of the posterior limb of the left internal capsule. Vessel imaging revealed an aberrant right subclavian artery. Atrophy of the right-sided muscles of mastication is consistent with her known diagnosis of right-sided PRS. Stroke workup revealed a patent foramen ovale; however, no evidence of deep venous thrombosis was found. Hypercoagulability workup revealed an elevated ANA. The cause of stroke in this patient with PRS remains unclear, as she has no known risk factors. CONCLUSION: It is possible that elevated inflammatory markers associated with PRS may cause a proinflammatory state and predispose patients to small-vessel vasculopathy. It is important to note the association between PRS and ischemic stroke.

ASPECTS-based reperfusion status on arterial spin labeling is associated with clinical outcome in acute ischemic stroke patients.

The purpose of this study was to develop and evaluate a scoring system for assessing reperfusion status based on arterial spin labeled (ASL) perfusion MRI in acute ischemic stroke (AIS) patients receiving thrombolysis and/or endovascular treatment. Pseudo-continuous ASL with background suppressed 3D GRASE was acquired along with DWI in 90 patients within 24 h post-treatment. An automatic reperfusion scoring system (auto-RPS) was devised based on the Alberta Stroke Program Early CT Score (ASPECTS) template, and compared with manual RPS and DWI-ASPECTS. TICI (thrombolysis in cerebral infarction) scores were graded in 48 patients who received endovascular treatment. Favorable outcomes were defined by a modified Rankin Scale score of 0-2 at three months. Auto-RPS was positively correlated with DWI-ASPECTS (ρ = 0.6, P < 0.001) and was on average 1 point lower than DWI-ASPECTS ( P < 0.001). The area under the receiver operating characteristic curve for discriminating poor functional outcome (n = 90) was 0.75 (95% CI, 0.64-0.86) for manual RPS, 0.85 (95% CI, 0.76-0.94) for auto-RPS, and 0.81 (95% CI, 0.71-0.90) for DWI-ASPECTS. Multiple logistic regression analysis in the TICI-graded patients (n = 48) showed that auto-RPS is highly associated with functional outcome (OR = 25.2, 95% CI 4.02-496, P < 0.01). Post treatment auto-RPS within 24 h provides a useful tool to predict functional outcome in AIS patients.

Peptide Composition of Stroke Causing Emboli Correlate with Serum Markers of Atherosclerosis and Inflammation.

INTRODUCTION: The specific protein composition of stroke-causing emboli is unknown. Because ischemic stroke has a varied etiology, it is possible that the composition of the thrombus from which an embolus originated will have distinctive molecular characteristics reflective of the underlying pathophysiology. We used mass spectrometry to evaluate the protein composition of retrieved emboli from patients with differing stroke etiologies and correlated the protein levels to serum predictors of atherosclerosis. METHODS: Emboli from 20 consecutive acute stroke patients were retrieved by thrombectomy during routine stroke care. Thrombus proteins were extracted, digested, and multidimensional fractionation of peptides was performed. Fractionated peptides underwent nano-liquid chromatography with tandem mass spectrometry. Spectra were searched using Mascot software in which results with p < 0.05 (95% confidence interval) were considered significant and indicating identity. The results were correlated to A1C, low-density lipoprotein (LDL), and erythrocyte sedimentation rate (ESR) taken on admission. RESULTS: Eleven patients had atrial fibrillation, four had significant proximal vessel atherosclerosis, two were cryptogenic, and three had other identified stroke risk factors (left ventricular thrombus, dissection, endocarditis). Eighty-one common proteins (e.g., hemoglobin, fibrin, actin) were found in all 20 emboli. Serum LDL levels correlated with Septin-2 (rs = 0.78, p = 0.028), Phosphoglycerate Kinase 1 (rs = 0.75, p = 0.036), Integrin Alpha-M (rs = 0.68, p = 0.033) and Glucose-6-phosphate dehydrogenase (rs = 0.63, p = 0.05). Septin-7 levels inversely correlated to ESR (rs = -0.84, p = 0.01). No significant protein correlations to A1C or tPA use were found. CONCLUSION: Our exploratory study presents mass spectrometry analysis of thrombi retrieved from acute stroke patients and correlates the thrombus proteome to clinical features of the patient. Notably, we found proteins associated with inflammation (e.g., Integrin Alpha-M) in emboli from patients with high LDL. Although these findings are tempered by a small sample size, we provide preliminary support for the feasibility of utilizing proteomic analysis of emboli to discover proteins that may be used as markers for stroke etiology.

Utilization of Statins Beyond the Initial Period After Stroke and 1-Year Risk of Recurrent Stroke.

BACKGROUND: In-hospital discontinuation of statins has been linked to poorer early stroke outcomes, but the consequences of postdischarge discontinuation or dose reduction of statin treatment are unknown. The objective of this study was to explore the effects of statin discontinuation or statin dose reduction on recurrent stroke risk. METHODS AND RESULTS: We conducted a nationwide cohort study using the data from the Taiwan National Health Insurance Research Database. Our source population comprised all patients who were prescribed a statin within 90 days of discharge after an ischemic stroke between 2001 and 2012. Patients were categorized into 3 groups: statin-discontinued, statin-reduced, and statin-maintained. Cox proportional hazard models were used to estimate the hazard ratios and 95%CIs of recurrent stroke during 1-year follow-up in the groups who discontinued statins or reduced statin dose compared with the group who maintained statins as the reference. Among the 45 151 ischemic stroke patients meeting criteria, during the day-90 to day-180 period, 7.0% were on reduced statin therapy, and 18.5% were not on any statin therapy. Compared with maintained-statin intensity therapy, discontinuation of statins was associated with an increased hazard of recurrent stroke (adjusted hazard ratio 1.42, 95%CI 1.28-1.57), whereas reduced-statin dose was not associated with an additional risk (adjusted hazard ratio 0.94, 95%CI 0.78-1.12). Propensity-matching analysis obtained similar results. CONCLUSIONS: Discontinuation of statin therapy between 3 and 6 months after an index ischemic stroke was associated with a higher risk of recurrent stroke within 1 year after statin discontinuation.

Antiplatelet Regimen for Patients With Breakthrough Strokes While on Aspirin: A Systematic Review and Meta-Analysis.

BACKGROUND AND PURPOSE: Optimal antiplatelet therapy after an ischemic stroke or transient ischemic attack while on aspirin is uncertain. We, therefore, conducted a systematic review and meta-analysis. METHODS: We searched PubMed (1966 to August 2016) and bibliographies of relevant published original studies to identify randomized trials and cohort studies reporting patients who were on aspirin at the time of an index ischemic stroke or transient ischemic attack and reported hazard ratio for major adverse cardiovascular events or recurrent stroke associated with a switch to or addition of another antiplatelet agent versus maintaining aspirin monotherapy. Estimates were combined using a random effects model. RESULTS: Five studies with 8723 patients with ischemic stroke or transient ischemic attack were identified. Clopidogrel was used in 4 cohorts, and ticagrelor was used in 1 cohort. Pooling results showed that addition of or a switch to another antiplatelet agent, versus aspirin monotherapy, was associated with reduced risks of major adverse cardiovascular events (hazard ratio, 0.68; 95% confidence interval, 0.54-0.85) and recurrent stroke (hazard ratio, 0.70; 95% confidence interval, 0.54-0.92). Each of the strategies of addition of and switching another antiplatelet agent showed benefit versus continued aspirin monotherapy, and studies with regimen initiation in the first days after index event showed more homogenous evidence of benefit. CONCLUSIONS: Among patients who experience an ischemic stroke or transient ischemic attack while on aspirin monotherapy, the addition of or a switch to another antiplatelet agent, especially in the first days after index event, is associated with fewer future vascular events, including stroke.

Effect of statin use on clinical outcomes in ischemic stroke patients with atrial fibrillation.

It remains unclear whether statin therapy should be applied to ischemic stroke patients with atrial fibrillation. The objective of this study was to clarify whether statin therapy can influence the prognosis in recent ischemic stroke patients with atrial fibrillation.We identified ischemic stroke patients with atrial fibrillation between 2001 and 2011 from Taiwan National Health Insurance Database. Patients not treated with statins during the first 90 days after the index stroke were matched to patients treated with statins in the first 90 days in a 2:1 ratio on the basis of age, sex, hypertension, diabetes mellitus, ischemic heart disease, heart failure, estimated National Institutes of Health Stroke Scale, use of anticoagulant, and year of their entry into the cohort. The primary outcome was the first event of recurrent stroke, and the secondary outcome was in-hospital death.A total of 1546 atrial fibrillation patients with statin therapy in the first 90 days poststroke and 3092 matched atrial fibrillation nonstatin controls were enrolled for this analysis. During the median 2.4-year follow-up, the risk of recurrent stroke was not different between subjects receiving versus not receiving statin therapy (hazard ratios = 1.01, 95% confidence interval 0.88 to 1.15). However, patients with atrial fibrillation receiving statin therapy had a reduced risk for death during any hospitalization throughout the long-term follow-up period (hazard ratios = 0.74, 95% confidence interval 0.61 to 0.89).Among ischemic stroke patients with atrial fibrillation, statin therapy initiated during the acute to subacute poststroke stage did not alter the rate of stroke recurrence but was associated with a decreased rate of in-hospital death.

Randomized controlled trial of a coordinated care intervention to improve risk factor control after stroke or transient ischemic attack in the safety net: Secondary stroke prevention by Uniting Community and Chronic care model teams Early to End Disparities (SUCCEED).

BACKGROUND: Recurrent strokes are preventable through awareness and control of risk factors such as hypertension, and through lifestyle changes such as healthier diets, greater physical activity, and smoking cessation. However, vascular risk factor control is frequently poor among stroke survivors, particularly among socio-economically disadvantaged blacks, Latinos and other people of color. The Chronic Care Model (CCM) is an effective framework for multi-component interventions aimed at improving care processes and outcomes for individuals with chronic disease. In addition, community health workers (CHWs) have played an integral role in reducing health disparities; however, their effectiveness in reducing vascular risk among stroke survivors remains unknown. Our objectives are to develop, test, and assess the economic value of a CCM-based intervention using an Advanced Practice Clinician (APC)-CHW team to improve risk factor control after stroke in an under-resourced, racially/ethnically diverse population. METHODS/DESIGN: In this single-blind randomized controlled trial, 516 adults (≥40 years) with an ischemic stroke, transient ischemic attack or intracerebral hemorrhage within the prior 90 days are being enrolled at five sites within the Los Angeles County safety-net setting and randomized 1:1 to intervention vs usual care. Participants are excluded if they do not speak English, Spanish, Cantonese, Mandarin, or Korean or if they are unable to consent. The intervention includes a minimum of three clinic visits in the healthcare setting, three home visits, and Chronic Disease Self-Management Program group workshops in community venues. The primary outcome is blood pressure (BP) control (systolic BP <130 mmHg) at 1 year. Secondary outcomes include: (1) mean change in systolic BP; (2) control of other vascular risk factors including lipids and hemoglobin A1c, (3) inflammation (C reactive protein [CRP]), (4) medication adherence, (5) lifestyle factors (smoking, diet, and physical activity), (6) estimated relative reduction in risk for recurrent stroke or myocardial infarction (MI), and (7) cost-effectiveness of the intervention versus usual care. DISCUSSION: If this multi-component interdisciplinary intervention is shown to be effective in improving risk factor control after stroke, it may serve as a model that can be used internationally to reduce race/ethnic and socioeconomic disparities in stroke in resource-constrained settings. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT01763203 .

Multi-delay ASL can identify leptomeningeal collateral perfusion in endovascular therapy of ischemic stroke.

BACKGROUND AND PURPOSE: Multi-delay arterial spin-labeling (ASL) perfusion imaging has been used as a promising modality to evaluate cerebral perfusion. Our aim was to assess the association of leptomeningeal collateral perfusion scores based on ASL parameters with outcome of endovascular treatment in patients with acute ischemic stroke (AIS) in the middle cerebral artery (MCA) territory. MATERIALS AND METHODS: ASL data at 4 post-labeling delay (PLD) times (PLD = 1.5, 2, 2.5, 3 s) were acquired during routine clinical magnetic resonance examination on AIS patients prior to endovascular treatment. A 3-point scale of leptomeningeal collateral perfusion grade on 10 anatomic regions was determined based on arterial transit times (ATT), cerebral blood flow (CBF), and arterial cerebral blood volume (CBV), estimated by the multi-delay ASL protocol. Based on a 90-day modified Rankin Scale (mRS), the patients were dichotomized to moderate/good (mRS 0-3) and poor outcome (mRS 4-6) and the regional collateral flow scores were compared. RESULTS: Fifty-five AIS patients with unilateral MCA stroke (mean 73.95±14.82 years) including 23 males were enrolled. Compared with poor outcome patients, patients with moderate to good outcomes had a significantly higher leptomeningeal collateral perfusion scores on CBV (3.01±2.11 vs. 1.82±1.51, p=0.024) but no differences on scores on CBF (2.31±1.61 vs. 1.66±1.32, p=0.231) and ATT (2.67±2.33 vs. 3.42±3.37, p=0.593). CONCLUSIONS: Higher leptomeningeal collateral perfusion scores on CBV images by ASL may be a specific marker of clinical outcome after endovascular treatment in patients with acute MCA ischemic stroke. Further study with larger sample size is warranted.