Assessment of smoking care by stroke specialists in patients with recent TIA and minor stroke: an international prospective registry-based cohort study.

OBJECTIVES: The objectives are to assess smoking abstinence and its effects on vascular risk and to report tobacco-cessation counselling and pharmacotherapy use in patients who had a recent minor stroke or transient ischaemic attack (TIA). DESIGN AND SETTING: The TIA registry.org project is a prospective, observational registry of patients with TIA and minor stroke that occurred in the previous 7 days with a 5-year follow-up, involving 61 sites with stroke specialists in 21 countries (Europe, Asia, Latin America and Middle East). Of those, 42 sites had 5-year follow-up data on more than 50% of their patients and were included in the present study. PARTICIPANTS: From June 2009 through December 2011, 3847 patients were eligible for the study (80% of the initial cohort). OUTCOMES: Tobacco counselling and smoking-cessation pharmacotherapy use in smoking patients were reported at discharge. Association between 3-month smoking status and risk of a major cardiovascular event (MACE) was analysed with multivariable Cox regression model. RESULTS: Among 3801 patients included, 835 (22%) were smokers. At discharge, only 35.2% have been advised to quit and 12.5% had smoking-cessation pharmacotherapy prescription. At 3 months, 383/835 (46.9%) baseline smokers were continuers. Living alone and alcohol abuse were associated with persistent smoking; high level of education, aphasia and dyslipidaemia with quitting. The adjusted HRs for MACE at 5 years were 1.13 (95% CI 0.90 to 1.43) in former smokers, 1.31 (95% CI 0.93 to 1.84) in quitters and 1.31 (95% CI 0.94 to 1.83) in continuers. Using time-varying analysis, current smoking at the time of MACE non-significantly increased the risk of MACE (HR 1.31 (95% CI 0.97 to 1.78); p=0.080). CONCLUSION: In the TIAregistry.org, smoking-cessation intervention was used in a minority of patients. Surprisingly, in this population in which, at 5 years, other vascular risk factors were well controlled and antithrombotic treatment maintained, smoking cessation non-significantly decreased the risk of MACE.

Neurological outcomes for patients meeting radiographic criteria for DEFUSE 3 and SELECT2.

BACKGROUND: The DEFUSE 3 and SELECT2 thrombectomy trials included some patients with similar radiographic profiles, although the rates of good functional outcomes differed widely between the studies. OBJECTIVE: To report neurological outcomes for patients who meet CT and CT perfusion (CTP) inclusion criteria common to both DEFUSE 3 and SELECT2. METHODS: Retrospective study of thrombectomy patients, presenting between November 2016 and December 2023 to a large health system, with Alberta Stroke Program Early CT score ≥6, core infarction 50-69 mL, mismatch ratio ≥1.8, and mismatch volume ≥15 mL. The primary outcome was 90-day modified Rankin Scale score 0-2. A logistic regression analysis was performed to identify independent predictors of the primary outcome. RESULTS: 85 patients, with mean age 64.6 (16.6) years and median National Institutes of Health Stroke Scale score 18 (15-23), were included. Thirty-eight of 85 patients (44.7%) were functionally independent at 90 days. Predictors of functional independence included age (OR=0.943, 95% CI 0.908 to 0.980; P=0.003), initial glucose (OR=0.989, 95% CI 0.978 to 1.000; P=0.044), and time last known well to skin puncture (OR=0.997, 95% CI 0.994 to 1.000; P=0.028). The area under the curve for the multivariable model predicting the primary outcome was 0.82 (95% CI 0.73 to 0.92). CONCLUSION: Nearly half of patients meeting radiographic criteria common to DEFUSE 3 and SELECT2 are functionally independent at 90 days, similar to rates reported for the treated DEFUSE 3 cohort. This might be due to their moderate core volumes and large ischemic penumbra.

Acute myocardial infarction and ischaemic stroke: differences and similarities in reperfusion therapies-a review.

Acute ST-elevation myocardial infarction (STEMI) and acute ischaemic stroke (AIS) share a number of similarities. However, important differences in pathophysiology demand a disease-tailored approach. In both conditions, fast treatment plays a crucial role as ischaemia and eventually infarction develop rapidly. Furthermore, in both fields, the introduction of fibrinolytic treatments historically preceded the implementation of endovascular techniques. However, in contrast to STEMI, only a minority of AIS patients will eventually be considered eligible for reperfusion treatment. Non-invasive cerebral imaging always precedes cerebral angiography and thrombectomy, whereas coronary angiography is not routinely preceded by non-invasive cardiac imaging in patients with STEMI. In the late or unknown time window, the presence of specific patterns on brain imaging may help identify AIS patients who benefit most from reperfusion treatment. For STEMI, a uniform time window for reperfusion up to 12 h after symptom onset, based on old placebo-controlled trials, is still recommended in guidelines and generally applied. Bridging fibrinolysis preceding endovascular treatment still remains the mainstay of reperfusion treatment in AIS, while primary percutaneous coronary intervention is the strategy of choice in STEMI. Shortening ischaemic times by fine-tuning collaboration networks between ambulances, community hospitals, and tertiary care hospitals, optimizing bridging fibrinolysis, and reducing ischaemia-reperfusion injury are important topics for further research. The aim of this review is to provide insights into the common as well as diverging pathophysiology behind current reperfusion strategies and to explore new ways to enhance their clinical benefit.

Predictors of Futile Recanalization in Ischemic Stroke Patients with low baseline NIHSS.

BACKGROUND: There is yet no randomized controlled evidence that mechanical thrombectomy (MT) is superior to best medical treatment in patients with large vessel occlusion but minor stroke symptoms (National Institutes of Health Stroke Scale [NIHSS] <6). Prior studies of patients with admission NIHSS scores >6 observed unfavorable functional outcomes despite successful recanalization, commonly termed as futile recanalization (FR), in up to 50% of cases. AIM: The aim of this study is to determine the prevalence of FR in patients with minor stroke and identify associated patient-specific risk factors. METHODS: Our multicenter cohort study screened all patients prospectively enrolled in the German Stroke Registry Endovascular Treatment from 2015 to 2021 (n=13082). Included were patients who underwent MT for anterior circulation vessel occlusion with a baseline NIHSS score of <6 and successful recanalization (modified Thrombolysis in Cerebral Infarction [mTICI] score of 2b-3). FR was defined by a modified Rankin Scale (mRS) score of 2-6 at 90 days. Multivariable logistic regression analysis was conducted to explore factors associated with FR. RESULTS: A total of 674 patients met the inclusion criteria. FR occurred in 268 (40%) patients. Multivariable logistic regression analysis indicates that higher age (adjusted odds ratio: 1.04 [95% confidence interval: 1.02-1.06]), pre-stroke mRS 1 (aOR: 2.70 [1.51-4.84]), transfer from admission hospital to comprehensive stroke center (aOR: 1.67 [1.08-2.56]), longer time from symptom onset/last seen well to admission (aOR: 1.02 [1.00-1.04]), MT under general anesthesia (aOR: 1.78 [1.13-2.82]), higher NIHSS after 24 hours (aOR: 1.09 [1.05-1.14]), and symptomatic intracranial hemorrhage (aOR: 16.88 [2.03-140.14]) increased the odds of FR. There was no significant difference in primary outcome between achieving mTICI 2b or 3. CONCLUSIONS: Unfavorable functional outcomes despite successful vessel recanalization were frequent in acute ischemic stroke patients with low NIHSS scores on admission. We provide patient-specific risk factors that indicate an increased risk of FR and should be considered when treating patients with minor stroke. DATA ACCESS STATEMENT: The data that support the findings of our study are available on reasonable request after approval of the GSR steering committee.

Projections of Endovascular Therapy-Eligible Patients With Stroke for the US Population.

BACKGROUND: As stroke endovascular thrombectomy (EVT) treatment indications expand, understanding population-based EVT eligibility becomes critical for resource planning. We aimed to project current and future population-based EVT eligibility in the United States. METHODS: We conducted a post hoc analysis of the physician-adjudicated GCNKSS (Greater Cincinnati Northern Kentucky Stroke Study; 2015 epoch), a population-based, cross sectional, observational study of stroke incidence, treatment, and outcomes across a 5-county region. All hospitalized patients ≥18 years of age with acute ischemic stroke were ascertained using the International Classification of Diseases, Ninth Revision codes 430-436 and Tenth Revision codes I60-I67 and G45-G46 and extrapolated to the US adult census 2020. We determined the rate of EVT eligibility within the GCNKSS population using time from last known well to presentation (0-5 versus 5-23 hours), presenting National Institutes of Health Stroke Scale, and prestroke modified Rankin Scale. Both conservative and liberal estimates of prevalence of large vessel occlusion and large core were then applied based on literature review (unavailable within the 2015 GCNKSS). This eligibility was then extrapolated to the 2020 US population. RESULTS: Of the 1 057 183 adults within GCNKSS in 2015, 2741 had an ischemic stroke and 2176 had data available for analysis. We calculated that 8659 to 17 219 patients (conservative to liberal) meet the current guideline-recommended EVT criteria (nonlarge core, no prestroke disability, and National Institutes of Health Stroke Scale score ≥6) in the United States. Estimates (conservative to liberal) for expanded EVT eligibility subpopulations include (1) 5316 to 10 635 by large core; (2) 10 635 to 21 270 by mild presenting deficits with low National Institutes of Health Stroke Scale score; (3) 13 572 to 27 089 by higher prestroke disability; and (4) 7039 to 14 180 by >1 criteria. These expanded eligibility subpopulations amount to 36 562 to 73 174 patients. CONCLUSIONS: An estimated 8659 to 17 219 adult patients in the United States met strict EVT eligibility criteria in 2020. A 4-fold increase in population-based EVT eligibility can be anticipated with incremental adoption of recent or future positive trials. US stroke systems need to be rapidly optimized to handle all EVT-eligible patients with stroke.

Lower admission stroke severity is associated with good collateral status in distal medium vessel occlusion stroke.

BACKGROUND AND PURPOSE: Distal medium vessel occlusions (DMVOs) are a significant contributor to acute ischemic stroke (AIS), with collateral status (CS) playing a pivotal role in modulating ischemic damage progression. We aimed to explore baseline characteristics associated with CS in AIS-DMVO. METHODS: This retrospective analysis of a prospectively collected database enrolled 130 AIS-DMVO patients from two comprehensive stroke centers. Baseline characteristics, including patient demographics, admission National Institutes of Health Stroke Scale (NIHSS) score, admission Los Angeles Motor Scale (LAMS) score, and co-morbidities, including hypertension, hyperlipidemia, diabetes, coronary artery disease, atrial fibrillation, and history of transient ischemic attack or stroke, were collected. The analysis was dichotomized to good CS, reflected by hypoperfusion index ratio (HIR) <.3, versus poor CS, reflected by HIR ≥.3. RESULTS: Good CS was observed in 34% of the patients. As to the occluded location, 43.8% occurred in proximal M2, 16.9% in mid M2, 35.4% in more distal middle cerebral artery, and 3.8% in distal anterior cerebral artery. In multivariate logistic analysis, a lower NIHSS score and a lower LAMS score were both independently associated with a good CS (odds ratio [OR]: 0.88, 95% confidence interval [CI]: 0.82-0.95, p < .001 and OR: 0.77, 95% CI: 0.62-0.96, p = .018, respectively). Patients with poor CS were more likely to manifest as moderate to severe stroke (29.1% vs. 4.5%, p < .001), while patients with good CS had a significantly higher chance of having a minor stroke clinically (40.9% vs. 12.8%, p < .001). CONCLUSIONS: CS remains an important determinant in the severity of AIS-DMVO. Collateral enhancement strategies may be a worthwhile pursuit in AIS-DMVO patients with more severe initial stroke presentation, which can be swiftly identified by the concise LAMS and serves as a proxy for underlying poor CS.

Arterial Recanalization During Interhospital Transfer for Thrombectomy.

BACKGROUND: Patients with acute ischemic stroke harboring a large vessel occlusion admitted to nonendovascular-capable centers often require interhospital transfer for thrombectomy. We evaluated the incidence and predictors of arterial recanalization during transfer, as well as the relationship between interhospital recanalization and clinical outcomes. METHODS: We analyzed data from 2 cohorts of patients with an anterior circulation large vessel occlusion transferred for consideration of thrombectomy to a comprehensive center, with arterial imaging at the referring hospital and on comprehensive stroke center arrival. Interhospital recanalization was determined by comparison of the baseline and posttransfer arterial imaging and was defined as revised arterial occlusive lesion (rAOL) score 2b to 3. Pretransfer variables independently associated with interhospital recanalization were studied using multivariable logistic regression analysis. RESULTS: Of the 520 included patients (Montpellier, France, n=237; Stanford, United States, n=283), 111 (21%) experienced interhospital recanalization (partial [rAOL=2b] in 77% and complete [rAOL=3] in 23%). Pretransfer variables independently associated with recanalization were intravenous thrombolysis (adjusted odds ratio, 6.8 [95% CI, 4.0-11.6]), more distal occlusions (intracranial carotid occlusion as reference: adjusted odds ratio, 2.0 [95% CI, 0.9-4.5] for proximal first segment of the middle cerebral artery, 5.1 [95% CI, 2.3-11.5] for distal first segment of the middle cerebral artery, and 5.0 [95% CI, 2.1-11.8] for second segment of the middle cerebral artery), and smaller clot burden (clot burden score 0-4 as reference: adjusted odds ratio, 3.4 [95% CI, 1.5-7.6] for 5-7 and 5.6 [95% CI, 2.4-12.7] for 8-9). Recanalization on arrival at the comprehensive center was associated with less interhospital infarct growth (rAOL, 0-2a: 11.6 mL; rAOL, 2b: 2.2 mL; rAOL, 3: 0.6 mL; Ptrend<0.001) and greater interhospital National Institutes of Health Stroke Scale score improvement (0 versus -5 versus -6; Ptrend<0.001). Interhospital recanalization was associated with reduced 3-month disability (adjusted common odds ratio, 2.51 [95% CI, 1.68-3.77]) with greater benefit from complete than partial recanalization. CONCLUSIONS: Recanalization is frequently observed during interhospital transfer for thrombectomy and is strongly associated with favorable outcomes, even when partial. Broadening thrombolysis indications in primary centers, and developing therapies that increase recanalization during transfer, will likely improve clinical outcomes.

Clinical change during inter-hospital transfer for thrombectomy: Incidence, associated factors, and relationship with outcome.

BACKGROUND: Patients with acute ischemic stroke with a large vessel occlusion (LVO) admitted to non endovascular-capable centers often require inter-hospital transfer for thrombectomy. We aimed to describe the incidence of substantial clinical change during transfer, the factors associated with clinical change, and its relationship with 3-month outcome. METHODS: We analyzed data from two cohorts of acute stroke patients transferred for thrombectomy to a comprehensive center (Stanford, USA, November 2019 to January 2023; Montpellier, France, January 2015 to January 2017), regardless of whether thrombectomy was eventually attempted. Patients were included if they had evidence of an LVO at the referring hospital and had a National Institute of Health Stroke Scale (NIHSS) score documented before and immediately after transfer. Inter-hospital clinical change was categorized as improvement (⩾4 points and ⩾25% decrease between the NIHSS score in the referring hospital and upon comprehensive center arrival), deterioration (⩾4 points and ⩾25% increase), or stability (neither improvement nor deterioration). The stable group was considered as the reference and was compared to the improvement or deterioration groups separately. RESULTS: A total of 504 patients were included, of whom 22% experienced inter-hospital improvement, 14% deterioration, and 64% were stable. Pre-transfer variables independently associated with clinical improvement were intravenous thrombolysis use, more distal occlusions, and lower serum glucose; variables associated with deterioration included more proximal occlusions and higher serum glucose. On post-transfer imaging, clinical improvement was associated with arterial recanalization and smaller infarct growth and deterioration with larger infarct growth. As compared to stable patients, those with clinical improvement had better 3-month functional outcome (adjusted common odds ratio (cOR) = 2.43; 95% confidence interval (CI) = 1.59-3.71; p < 0.001), while those with deterioration had worse outcome (adjusted cOR = 0.60; 95% CI = 0.37-0.98; p = 0.044). CONCLUSION: Substantial inter-hospital clinical changes are frequently observed in LVO-related ischemic strokes, with significant impact on functional outcome. There is a need to develop treatments that improves the clinical status during transfer. DATA ACCESS STATEMENT: The data that support the findings of this study are available upon reasonable request.

Follow-up infarct volume on fluid attenuated inversion recovery (FLAIR) imaging in distal medium vessel occlusions: the role of cerebral blood volume index.

BACKGROUND: Distal medium vessel occlusions (DMVOs) contribute substantially to the incidence of acute ischemic strokes (AIS) and pose distinct challenges in clinical management and prognosis. Neuroimaging techniques, such as Fluid Attenuation Inversion Recovery (FLAIR) imaging and cerebral blood volume (CBV) index derived from perfusion imaging, have significantly improved our ability to assess the impact of strokes and predict their outcomes. The primary objective of this study was to investigate relationship between follow-up infarct volume (FIV) as assessed by FLAIR imaging in patients with DMVOs. METHODS: This prospectively collected, retrospective reviewed cohort study included patients from two comprehensive stroke centers within the Johns Hopkins Medical Enterprise, spanning August 2018-October 2022. The cohort consisted of adults with AIS attributable to DMVO. Detailed imaging analyses were conducted, encompassing non-contrast CT, CT angiography (CTA), CT perfusion (CTP), and FLAIR imaging. Univariable and multivariable linear regression models were employed to assess the association between different factors and FIV. RESULTS: The study included 79 patients with DMVO stroke with a median age of 69 years (IQR, 62-77 years), and 57% (n = 45) were female. There was a negative correlation between the CBV index and FIV in a univariable linear regression analysis (Beta = - 16; 95% CI, - 23 to - 8.3; p < 0.001) and a multivariable linear regression model (Beta = - 9.1 per 0.1 change; 95% CI, - 15 to - 2.7; p = 0.006). Diabetes was independently associated with larger FIV (Beta = 46; 95% CI, 16 to 75; p = 0.003). Additionally, a higher baseline ASPECTS was associated with lower FIV (Beta = - 30; 95% CI, - 41 to - 20; p < 0.001). CONCLUSION: Our findings underscore the CBV index as an independent association with FIV in DMVOs, which highlights the critical role of collateral circulation in determining stroke outcomes in this patient population. In addition, our study confirms a negative association of ASPECTS with FLAIR FIV and identifies diabetes as independent factor associated with larger FIV. These insights pave the way for further large-scale, prospective studies to corroborate these findings, thereby refining the strategies for stroke prognostication and management.

Stroke in the Time of Circadian Medicine.

Time-of-day significantly influences the severity and incidence of stroke. Evidence has emerged not only for circadian governance over stroke risk factors, but also for important determinants of clinical outcome. In this review, we provide a comprehensive overview of the interplay between chronobiology and cerebrovascular disease. We discuss circadian regulation of pathophysiological mechanisms underlying stroke onset or tolerance as well as in vascular dementia. This includes cell death mechanisms, metabolism, mitochondrial function, and inflammation/immunity. Furthermore, we present clinical evidence supporting the link between disrupted circadian rhythms and increased susceptibility to stroke and dementia. We propose that circadian regulation of biochemical and physiological pathways in the brain increase susceptibility to damage after stroke in sleep and attenuate treatment effectiveness during the active phase. This review underscores the importance of considering circadian biology for understanding the pathology and treatment choice for stroke and vascular dementia and speculates that considering a patient's chronotype may be an important factor in developing precision treatment following stroke.

Prolonged venous transit on perfusion imaging is associated with higher odds of mortality in successfully reperfused patients with large vessel occlusion stroke.

BACKGROUND: Poor venous outflow (VO) profiles are associated with unfavorable outcomes in patients with acute ischemic stroke caused by large vessel occlusion (AIS-LVO), despite achieving successful reperfusion. The objective of this study is to assess the association between mortality and prolonged venous transit (PVT), a novel visual qualitative VO marker on CT perfusion (CTP) time to maximum (Tmax) maps. METHODS: We performed a retrospective analysis of prospectively collected data from consecutive adult patients with AIS-LVO with successful reperfusion (modified Thrombolysis in Cerebral Infarction 2b/2c/3). PVT+ was defined as Tmax ≥10 s timing on CTP Tmax maps in at least one of the following: superior sagittal sinus (proximal venous drainage) and/or torcula (deep venous drainage). PVT- was defined as lacking this in both regions. The primary outcome was mortality at 90 days. In a 1:1 propensity score-matched cohort, regressions were performed to determine the effect of PVT on 90-day mortality. RESULTS: In 127 patients of median (IQR) age 71 (64-81) years, mortality occurred in a significantly greater proportion of PVT+ patients than PVT- patients (32.5% vs 12.6%, P=0.01). This significant difference persisted after matching (P=0.03). PVT+ was associated with a significantly increased likelihood of 90-day mortality (OR 1.22 (95% CI 1.02 to 1.46), P=0.03) in the matched cohort. CONCLUSIONS: PVT+ was significantly associated with 90-day mortality despite successful reperfusion therapy in patients with AIS-LVO. PVT is a simple VO profile marker with potential as an adjunctive metric during acute evaluation of AIS-LVO patients. Future studies will expand our understanding of using PVT in the evaluation of patients with AIS-LVO.

Tenecteplase for Stroke at 4.5 to 24 Hours with Perfusion-Imaging Selection.

BACKGROUND: Thrombolytic agents, including tenecteplase, are generally used within 4.5 hours after the onset of stroke symptoms. Information on whether tenecteplase confers benefit beyond 4.5 hours is limited. METHODS: We conducted a multicenter, double-blind, randomized, placebo-controlled trial involving patients with ischemic stroke to compare tenecteplase (0.25 mg per kilogram of body weight, up to 25 mg) with placebo administered 4.5 to 24 hours after the time that the patient was last known to be well. Patients had to have evidence of occlusion of the middle cerebral artery or internal carotid artery and salvageable tissue as determined on perfusion imaging. The primary outcome was the ordinal score on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability and a score of 6 indicating death) at day 90. Safety outcomes included death and symptomatic intracranial hemorrhage. RESULTS: The trial enrolled 458 patients, 77.3% of whom subsequently underwent thrombectomy; 228 patients were assigned to receive tenecteplase, and 230 to receive placebo. The median time between the time the patient was last known to be well and randomization was approximately 12 hours in the tenecteplase group and approximately 13 hours in the placebo group. The median score on the modified Rankin scale at 90 days was 3 in each group. The adjusted common odds ratio for the distribution of scores on the modified Rankin scale at 90 days for tenecteplase as compared with placebo was 1.13 (95% confidence interval, 0.82 to 1.57; P = 0.45). In the safety population, mortality at 90 days was 19.7% in the tenecteplase group and 18.2% in the placebo group, and the incidence of symptomatic intracranial hemorrhage was 3.2% and 2.3%, respectively. CONCLUSIONS: Tenecteplase therapy that was initiated 4.5 to 24 hours after stroke onset in patients with occlusions of the middle cerebral artery or internal carotid artery, most of whom had undergone endovascular thrombectomy, did not result in better clinical outcomes than those with placebo. The incidence of symptomatic intracerebral hemorrhage was similar in the two groups. (Funded by Genentech; TIMELESS ClinicalTrials.gov number, NCT03785678.).

A Clinical and Imaging Fused Deep Learning Model Matches Expert Clinician Prediction of 90-Day Stroke Outcomes.

BACKGROUND AND PURPOSE: Predicting long-term clinical outcome in acute ischemic stroke is beneficial for prognosis, clinical trial design, resource management, and patient expectations. This study used a deep learning-based predictive model (DLPD) to predict 90-day mRS outcomes and compared its predictions with those made by physicians. MATERIALS AND METHODS: A previously developed DLPD that incorporated DWI and clinical data from the acute period was used to predict 90-day mRS outcomes in 80 consecutive patients with acute ischemic stroke from a single-center registry. We assessed the predictions of the model alongside those of 5 physicians (2 stroke neurologists and 3 neuroradiologists provided with the same imaging and clinical information). The primary analysis was the agreement between the ordinal mRS predictions of the model or physician and the ground truth using the Gwet Agreement Coefficient. We also evaluated the ability to identify unfavorable outcomes (mRS >2) using the area under the curve, sensitivity, and specificity. Noninferiority analyses were undertaken using limits of 0.1 for the Gwet Agreement Coefficient and 0.05 for the area under the curve analysis. The accuracy of prediction was also assessed using the mean absolute error for prediction, percentage of predictions ±1 categories away from the ground truth (±1 accuracy [ACC]), and percentage of exact predictions (ACC). RESULTS: To predict the specific mRS score, the DLPD yielded a Gwet Agreement Coefficient score of 0.79 (95% CI, 0.71-0.86), surpassing the physicians' score of 0.76 (95% CI, 0.67-0.84), and was noninferior to the readers (P < .001). For identifying unfavorable outcome, the model achieved an area under the curve of 0.81 (95% CI, 0.72-0.89), again noninferior to the readers' area under the curve of 0.79 (95% CI, 0.69-0.87) (P < .005). The mean absolute error, ±1ACC, and ACC were 0.89, 81%, and 36% for the DLPD. CONCLUSIONS: A deep learning method using acute clinical and imaging data for long-term functional outcome prediction in patients with acute ischemic stroke, the DLPD, was noninferior to that of clinical readers.

Association between occlusion location, net water uptake and ischemic lesion growth in large vessel anterior circulation strokes.

Ischemic lesion net water uptake (NWU) represents a quantitative imaging biomarker for cerebral edema in acute ischemic stroke. Data on NWU for distinct occlusion locations remain scarce, but might help to improve the prognostic value of NWU. In this retrospective multicenter cohort study, we compared NWU between patients with proximal large vessel occlusion (pLVO; ICA or proximal M1) and distal large vessel occlusion (dLVO; distal M1 or M2). NWU was quantified by densitometric measurements of the early ischemic region. Arterial collateral status was assessed using the Maas scale. Regression analysis was used to investigate the relationship between occlusion location, NWU and ischemic lesion growth. A total of 685 patients met inclusion criteria. Early ischemic lesion NWU was higher in patients with pLVO compared with dLVO (7.7% vs 3.9%, P < .001). The relationship between occlusion location and NWU was partially mediated by arterial collateral status. NWU was associated with absolute ischemic lesion growth between admission and follow-up imaging (ß estimate, 5.50, 95% CI, 3.81-7.19, P < .001). This study establishes a framework for the relationship between occlusion location, arterial collateral status, early ischemic lesion NWU and ischemic lesion growth. Future prognostic thresholds for NWU might be optimized by adjusting for the occlusion location.

Stroke and high-risk TIA outcomes with reduction of treatment duration when treatment initiated in emergency rooms (SHORTER-study).

BACKGROUND: Following transient ischemic attack (TIA) and minor stroke, the risk of recurrent stroke can be significantly reduced with short-duration dual antiplatelet therapy (DAPT). We wish to investigate whether 10 days of DAPT is as effective as 21 days' treatment. STUDY DESIGN: This is an open-label, randomized, parallel-group study comparing whether 10 days of DAPT treatment (ASA + clopidogrel) is non-inferior to 21 days of DAPT in patients with acute ischemic stroke (AIS) or high-risk TIA. In both groups, DAPT is started within 24 hours of symptom onset. This study is being conducted in approximately 15 study sites in the Kingdom of Saudi Arabia. The planned sample size is 1932. OUTCOMES: Non-inferiority of 10 days compared to 21 days of DAPT in the prevention of the composite endpoint of stroke and death at 90 days in AIS/TIA patients. The primary safety outcome is major intra-cranial and systemic hemorrhage. STUDY PERIOD: Enrolment started in the second quarter of 2023, and the completion of the study is expected in the fourth quarter of 2025. DISCUSSION: The trial is expected to show that 10 days of DAPT is non-inferior for the prevention of early recurrence of vascular events in patients with high-risk TIAs and minor strokes.

Random expert sampling for deep learning segmentation of acute ischemic stroke on non-contrast CT.

BACKGROUND: Outlining acutely infarcted tissue on non-contrast CT is a challenging task for which human inter-reader agreement is limited. We explored two different methods for training a supervised deep learning algorithm: one that used a segmentation defined by majority vote among experts and another that trained randomly on separate individual expert segmentations. METHODS: The data set consisted of 260 non-contrast CT studies in 233 patients with acute ischemic stroke recruited from the multicenter DEFUSE 3 (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3) trial. Additional external validation was performed using 33 patients with matched stroke onset times from the University Hospital Lausanne. A benchmark U-Net was trained on the reference annotations of three experienced neuroradiologists to segment ischemic brain tissue using majority vote and random expert sampling training schemes. The median of volume, overlap, and distance segmentation metrics were determined for agreement in lesion segmentations between (1) three experts, (2) the majority model and each expert, and (3) the random model and each expert. The two sided Wilcoxon signed rank test was used to compare performances (1) to 2) and (1) to (3). We further compared volumes with the 24 hour follow-up diffusion weighted imaging (DWI, final infarct core) and correlations with clinical outcome (modified Rankin Scale (mRS) at 90 days) with the Spearman method. RESULTS: The random model outperformed the inter-expert agreement ((1) to (2)) and the majority model ((1) to (3)) (dice 0.51±0.04 vs 0.36±0.05 (P<0.0001) vs 0.45±0.05 (P<0.0001)). The random model predicted volume correlated with clinical outcome (0.19, P<0.05), whereas the median expert volume and majority model volume did not. There was no significant difference when comparing the volume correlations between random model, median expert volume, and majority model to 24 hour follow-up DWI volume (P>0.05, n=51). CONCLUSION: The random model for ischemic injury delineation on non-contrast CT surpassed the inter-expert agreement ((1) to (2)) and the performance of the majority model ((1) to (3)). We showed that the random model volumetric measures of the model were consistent with 24 hour follow-up DWI.

Pretreatment CT perfusion collateral parameters correlate with penumbra salvage in middle cerebral artery occlusion.

BACKGROUND AND PURPOSE: Acute ischemic stroke due to large vessel occlusion (AIS-LVO) is a major cause of functional dependence. Collateral status (CS) is an important determinant of functional outcomes. Pretreatment CT perfusion (CTP) parameters serve as reliable surrogates of CS. Penumbra Salvage Index (PSI) is another parameter predictive of functional outcomes in AIS-LVO. The aim of this study is to assess the relationship of pretreatment CTP parameters with PSI. METHODS: In this prospectively collected, retrospectively reviewed multicenter analysis, inclusion criteria were as follows: (1) CT angiography confirmed middle cerebral artery (MCA) M1-segment and proximal M2-segment occlusion from 9/1/2017 to 9/22/2022; (2) diagnostic CTP; and (3) available diagnostic Magnetic resonance Imaging (MRI) diffusion-weighted images. Pearson correlation analysis was performed to assess the association between cerebral blood volume (CBV) index and hypoperfusion intensity ratio (HIR) with PSI. p value ≤.05 was considered statistically significant. RESULTS: In total, 131 patients (n = 86, M1 and n = 45, proximal M2 occlusion) met our inclusion criteria. CBV index showed a modest positive correlation with PSI (r = 0.34, p<.001) in patients with proximal MCA occlusion. Similar trends were noted in subgroup analysis of patients with M1 occlusion, and proximal M2 occlusion. Whereas, HIR did not have a strong trend or correlation with PSI. CONCLUSION: CBV index correlates with PSI, whereas HIR does not. Future studies are needed to expand our understanding of the adjunct role of CBV index with other similar pretreatment CTP-based markers in clinical evaluation and decision-making in patients with MCA occlusion.