Multicenter exploration of tenecteplase transition factors: A quantitative analysis.

BACKGROUND: Tenecteplase (TNK) is gaining recognition as a novel therapy for acute ischemic stroke (AIS). Despite TNK offering a longer half-life, time and cost saving benefits and comparable treatment and safety profiles to Alteplase (ALT), the adoption of TNK as a treatment for AIS presents challenges for hospital systems. OBJECTIVE: Identify barriers and facilitators of TNK implementation at acute care hospitals in Texas. METHODS: This prospective survey used open-ended questions and Likert statements generated from content experts and informed by qualitative research. Stroke clinicians and nurses working at 40 different hospitals in Texas were surveyed using a virtual platform. RESULTS: The 40 hospitals had a median of 34 (IQR 24.5-49) emergency department beds and 42.5 (IQR 23.5-64.5) inpatient stroke beds with 506.5 (IQR 350-797.5) annual stroke admissions. Fifty percent of the hospitals were Comprehensive Stroke Centers, and 18 (45 %) were solely using ALT for treatment of eligible AIS patients. Primary facilitators to TNK transition were team buy-in and a willingness of stroke physicians, nurses, and pharmacists to adopt TNK. Leading barriers were lack of clinical evidence supporting TNK safety profile inadequate evidence supporting TNK use and a lack of American Heart Association guidelines support for TNK administration in all AIS cases. CONCLUSION: Understanding common barriers and facilitators to TNK adoption can assist acute care hospitals deciding to implement TNK as a treatment for AIS. These findings will be used to design a TNK adoption Toolkit, utilizing implementation science techniques, to address identified obstacles and to leverage facilitators.

A qualitative study of barriers and facilitators to using tenecteplase to treat acute ischemic stroke.

BACKGROUND: Tenecteplase (TNK) is emerging as an alternative to alteplase (ALT) for thrombolytic treatment of acute ischemic stroke (AIS). Compared to ALT, TNK has a longer half-life, shorter administration time, lower cost, and similarly high efficacy in treating large vessel occlusion. Nevertheless, there are barriers to adopting TNK as a treatment for AIS. This study aimed to identify thematic barriers and facilitators to adopting TNK as an alternative to ALT as a thrombolytic for eligible AIS patients. METHODS: Qualitative research methodology using hermeneutic cycling and purposive sampling was used to interview four stroke clinicians in Texas. Interviews were recorded and transcribed verbatim. Enrollment was complete when saturation was reached. All members of the research team participated in content analysis during each cycle and in thematic analysis after saturation. RESULTS: Interviews were conducted between November 2022 and February 2023 with stroke center representatives from centers that either had successfully adopted TNK, or had not yet adopted TNK. Three themes and eight sub-themes were identified. The theme "Evidence" had three sub-themes: Pro-Con Balance, Fundamental Knowledge, and Pharmacotherapeutics. The theme "Process Flow" had four subthemes: Proactive, Reflective self-doubt, Change Process Barriers, and Parameter Barriers. The theme "Consensus" had one sub-theme: Getting Buy-In. CONCLUSION: Clinicians experience remarkably similar barriers and facilitators to adopting TNK. The results lead to a hypothesis that providing evidence to support a practice change, and identifying key change processes, will help clinicians achieve consensus across teams that need to 'buy in' to adopting TNK for AIS treatment.

White Matter Integrity and Chronic Poststroke Upper Limb Function: An ENIGMA Stroke Recovery Analysis.

BACKGROUND: Integrity of the corticospinal tract (CST) is an important biomarker for upper limb motor function following stroke. However, when structurally compromised, other tracts may become relevant for compensation or recovery of function. METHODS: We used the ENIGMA Stroke Recovery data set, a multicenter, retrospective, and cross-sectional collection of patients with upper limb impairment during the chronic phase of stroke to test the relevance of tracts in individuals with less and more severe (laterality index of CST fractional anisotropy ≥0.25) CST damage in an observational study design. White matter integrity was quantified using fractional anisotropy for the CST, the superior longitudinal fascicle, and the callosal fibers interconnecting the primary motor cortices between hemispheres. Optic radiations served as a control tract as they have no a priori relevance for the motor system. Pearson correlation was used for testing correlation with upper limb motor function (Fugl-Meyer upper extremity). RESULTS: From 1235 available data sets, 166 were selected (by imaging, Fugl-Meyer upper extremity, covariates, stroke location, and stage) for analyses. Only individuals with severe CST damage showed a positive association of fractional anisotropy in both callosal fibers interconnecting the primary motor cortices (r[21]=0.49; P=0.025) and superior longitudinal fascicle (r[21]=0.51; P=0.018) with Fugl-Meyer upper extremity. CONCLUSIONS: Our data support the notion that individuals with more severe damage of the CST depend on residual pathways for achieving better upper limb outcome than those with less affected CST.

Evolving Thrombolytics: from Alteplase to Tenecteplase.

Alteplase has been the primary thrombolytic used in the treatment of acute ischemic stroke since thrombolysis was first established as an effective treatment of acute ischemic stroke in 1995. Tenecteplase, a genetically modified tissue plasminogen activator, has gained attention as an attractive alternative to alteplase given its practical workflow advantages and possible superior efficacy in large vessel recanalization. As more data is analyzed both from randomized trials and non-randomized patient registries, there is mounting support that tenecteplase appears to be at least equally, if not more, safe and potentially more effective than alteplase in the treatment of acute ischemic stroke. Randomized trials investigating tenecteplase in the delayed treatment window and with thrombectomy are ongoing, and their results are eagerly awaited. This paper provides an overview of completed and ongoing randomized trials and nonrandomized studies analyzing tenecteplase in the treatment of acute ischemic stroke. Results reviewed support the safe use of tenecteplase in clinical practice.

Symptomatic Intracranial Hemorrhage With Tenecteplase vs Alteplase in Patients With Acute Ischemic Stroke: The Comparative Effectiveness of Routine Tenecteplase vs Alteplase in Acute Ischemic Stroke (CERTAIN) Collaboration.

Importance: Symptomatic intracranial hemorrhage (sICH) is a serious complication of stroke thrombolytic therapy. Many stroke centers have adopted 0.25-mg/kg tenecteplase instead of alteplase for stroke thrombolysis based on evidence from randomized comparisons to alteplase as well as for its practical advantages. There have been no significant differences in symptomatic intracranial hemorrhage (sICH) reported from randomized clinical trials or published case series for the 0.25-mg/Kg dose. Objective: To assess the risk of sICH following ischemic stroke in patients treated with tenecteplase compared to those treated with alteplase. Design, Setting, and Participants: This was a retrospective observational study using data from the large multicenter international Comparative Effectiveness of Routine Tenecteplase vs Alteplase in Acute Ischemic Stroke (CERTAIN) collaboration comprising deidentified data on patients with ischemic stroke treated with intravenous thrombolysis. Data from more than 100 hospitals in New Zealand, Australia, and the US that used alteplase or tenecteplase for patients treated between July 1, 2018, and June 30, 2021, were included for analysis. Participating centers included a mix of nonthrombectomy- and thrombectomy-capacity comprehensive stroke centers. Standardized data were abstracted and harmonized from local or regional clinical registries. Consecutive patients with acute ischemic stroke who were considered eligible and received thrombolysis at the participating stroke registries during the study period were included. All 9238 patients who received thrombolysis were included in this retrospective analysis. Main Outcomes and Measures: sICH was defined as clinical worsening of at least 4 points on the National Institutes of Health Stroke Scale (NIHSS), attributed to parenchymal hematoma, subarachnoid, or intraventricular hemorrhage. Differences between tenecteplase and alteplase in the risk of sICH were assessed using logistic regression, adjusted for age, sex, NIHSS score, and thrombectomy. Results: Of the 9238 patients included in the analysis, the median (IQR) age was 71 (59-80) years, and 4449 patients (48%) were female. Tenecteplase was administered to 1925 patients. The tenecteplase group was older (median [IQR], 73 [61-81] years vs 70 [58-80] years; P < .001), more likely to be male (1034 of 7313 [54%] vs 3755 of 1925 [51%]; P < .01), had higher NIHSS scores (median [IQR], 9 [5-17] vs 7 [4-14]; P < .001), and more frequently underwent endovascular thrombectomy (38% vs 20%; P < .001). The proportion of patients with sICH was 1.8% for tenecteplase and 3.6% for alteplase (P < .001), with an adjusted odds ratio (aOR) of 0.42 (95% CI, 0.30-0.58; P < .01). Similar results were observed in both thrombectomy and nonthrombectomy subgroups. Conclusions and Relevance: In this large study, ischemic stroke treatment with 0.25-mg/kg tenecteplase was associated with lower odds of sICH than treatment with alteplase. The results provide evidence supporting the safety of tenecteplase for stroke thrombolysis in real-world clinical practice.

Prospective Observational Cohort Study of Tenecteplase Versus Alteplase in Routine Clinical Practice.

BACKGROUND: A 10-hospital regional network transitioned to tenecteplase as the standard of care stroke thrombolytic in September 2019 because of potential workflow advantages and reported noninferior clinical outcomes relative to alteplase in meta-analyses of randomized trials. We assessed whether tenecteplase use in routine clinical practice reduced thrombolytic workflow times with noninferior clinical outcomes. METHODS: We designed a prospective registry-based observational, sequential cohort comparison of tenecteplase- (n=234) to alteplase-treated (n=354) stroke patients. We hypothesized: (1) an increase in the proportion of patients meeting target times for target door-to-needle time and transfer door-in-door-out time, and (2) noninferior favorable (discharge to home with independent ambulation) and unfavorable (symptomatic intracranial hemorrhage, in-hospital mortality or discharge to hospice) in the tenecteplase group. Total hospital cost associated with each treatment was also compared. RESULTS: Target door-to-needle time within 45 minutes for all patients was superior for tenecteplase, 41% versus 29%; adjusted odds ratio, 1.85 (95% CI, 1.27-2.71); P=0.001; 58% versus 41% by Get With The Guidelines criteria. Target door-in-door-out time within 90 minutes was superior for tenecteplase 37% (15/43) versus 14% (9/65); adjusted odds ratio, 3.62 (95% CI, 1.30-10.74); P=0.02. Favorable outcome for tenecteplase fell within the 6.5% noninferiority margin; adjusted odds ratio, 1.26 (95% CI, 0.89-1.80). Unfavorable outcome was less for tenecteplase, 7.3% versus 11.9%, adjusted odds ratio, 0.77 (95% CI, 0.42-1.37) but did not fall within the prespecified 1% noninferior boundary. Net benefit (%favorable-%unfavorable) was greater for the tenecteplase sample: 37% versus 27%. P=0.02. Median cost per hospital encounter was less for tenecteplase cases ($13 382 versus $15 841; P<0.001). CONCLUSIONS: Switching to tenecteplase in routine clinical practice in a 10-hospital network was associated with shorter door-to-needle time and door-in-door-out times, noninferior favorable clinical outcomes at discharge, and reduced hospital costs. Evaluation in larger, multicenter cohorts is recommended to determine if these observations generalize.

Use of deep artificial neural networks to identify stroke during triage via subtle changes in circulating cell counts.

BACKGROUND: The development of tools that could help emergency department clinicians recognize stroke during triage could reduce treatment delays and improve patient outcomes. Growing evidence suggests that stroke is associated with several changes in circulating cell counts. The aim of this study was to determine whether machine-learning can be used to identify stroke in the emergency department using data available from a routine complete blood count with differential. METHODS: Red blood cell, platelet, neutrophil, lymphocyte, monocyte, eosinophil, and basophil counts were assessed in admission blood samples collected from 160 stroke patients and 116 stroke mimics recruited from three geographically distinct clinical sites, and an ensemble artificial neural network model was developed and tested for its ability to discriminate between groups. RESULTS: Several modest but statistically significant differences were observed in cell counts between stroke patients and stroke mimics. The counts of no single cell population alone were adequate to discriminate between groups with high levels of accuracy; however, combined classification using the neural network model resulted in a dramatic and statistically significant improvement in diagnostic performance according to receiver-operating characteristic analysis. Furthermore, the neural network model displayed superior performance as a triage decision making tool compared to symptom-based tools such as the Cincinnati Prehospital Stroke Scale (CPSS) and the National Institutes of Health Stroke Scale (NIHSS) when assessed using decision curve analysis. CONCLUSIONS: Our results suggest that algorithmic analysis of commonly collected hematology data using machine-learning could potentially be used to help emergency department clinicians make better-informed triage decisions in situations where advanced imaging techniques or neurological expertise are not immediately available, or even to electronically flag patients in which stroke should be considered as a diagnosis as part of an automated stroke alert system.

Racial Disparity in Mechanical Thrombectomy Utilization: Multicenter Registry Results From 2016 to 2020.

Background Previous studies on racial disparity in mechanical thrombectomy (MT) treatment of acute large vessel occlusion stroke lack individual patient data that influence treatment decision-making. We assessed patient-level data in a large US health care system from 2016 to 2020 for racial disparities in MT utilization and eligibility. Methods and Results A retrospective study was performed of 34 596 patients admitted to 43 hospitals from January 2016 to September 2020. Data included patient age, sex, race, residential zip code median income and population density, presenting hospital stroke certification, baseline ambulation, and National Institutes of Health stroke scale. The cohort included 26 640 White, non-Hispanic (77.0%), and 7956 African American/Black (23.0%) patients. In multivariable logistic regression, Black patients were less likely to undergo MT (adjusted odds ratio [OR], 0.65; 95% CI, 0.54-0.76), arrive within 5 hours of "last known well" (adjusted OR, 0.73; 95% CI, 0.69-0.78), and have documented anterior circulation large vessel occlusion (adjusted OR, 0.78; 95% CI, 0.64-0.96). Race was not associated with MT rate among patients arriving within 5 hours of last known well with documented acute large vessel occlusion. Conclusions Black patients with stroke underwent MT less frequently than White patients, likely in part because of longer times from last known well to hospital arrival and a lower rate of documented acute large vessel occlusion. Further studies are needed to assess whether extending the MT time window and more aggressive large vessel occlusion screening protocols mitigate this disparity.

Patient Characteristics and Outcomes Associated with Decline in Stroke Volumes During the Early COVID-19 Pandemic.

BACKGROUND AND PURPOSE: Delayed evaluation of stroke may contribute to COVID-19 pandemic-related morbidity and mortality. This study evaluated patient characteristics, process measures and outcomes associated with the decline in stroke presentation during the early pandemic. METHODS: Volumes of stroke presentations, intravenous thrombolytic administrations, and mechanical thrombectomies from 52 hospitals from January 1-June 30, 2020 were analyzed with piecewise linear regression and linear spline models. Univariate analysis compared pandemic (case) and pre-pandemic (control) groups defined in relation to the nadir of daily strokes during the study period. Significantly different patient characteristics were further evaluated with logistic regression, and significantly different process measures and outcomes were re-analyzed after propensity score matching. RESULTS: Analysis of 7,389 patients found daily stroke volumes decreased 0.91/day from March 12-26 (p < 0.0001), reaching a nadir 35.0% less than expected, and increased 0.15 strokes/day from March 27-June 23, 2020 (p < 0.0001). Intravenous thrombolytic administrations decreased 3.3/week from February 19-March 31 (p = 0.0023), reaching a nadir 33.4% less than expected, and increased 1.4 administrations/week from April 1-June 23 (p < 0.0001). Mechanical thrombectomy volumes decreased by 1.5/week from February 19-March 31, 2020 (p = 0.0039), reaching a nadir 11.3% less than expected. The pandemic group was more likely to ambulate independently at baseline (p = 0.02, OR = 1.60, 95% CI = 1.08-2.42), and less likely to present with mild stroke symptoms (NIH Stroke Scale ≤ 5; p = 0.04, OR = 1.01, 95% CI = 1.00-1.02). Process measures and outcomes of each group did not differ, including door-to-needle time, door-to-puncture time, and successful mechanical thrombectomy rate. CONCLUSION: Stroke presentations and acute interventions decreased during the early COVID-19 pandemic, at least in part due to patients with lower baseline functional status and milder symptoms not seeking medical care. Public health messaging and initiatives should target these populations.

Tenecteplase Thrombolysis for Acute Ischemic Stroke.

Tenecteplase is a fibrinolytic drug with higher fibrin specificity and longer half-life than the standard stroke thrombolytic, alteplase, permitting the convenience of single bolus administration. Tenecteplase, at 0.5 mg/kg, has regulatory approval to treat ST-segment-elevation myocardial infarction, for which it has equivalent 30-day mortality and fewer systemic hemorrhages. Investigated as a thrombolytic for ischemic stroke over the past 15 years, tenecteplase is currently being studied in several phase 3 trials. Based on a systematic literature search, we provide a qualitative synthesis of published stroke clinical trials of tenecteplase that (1) performed randomized comparisons with alteplase, (2) compared different doses of tenecteplase, or (3) provided unique quantitative meta-analyses. Four phase 2 and one phase 3 study performed randomized comparisons with alteplase. These and other phase 2 studies compared different tenecteplase doses and effects on early outcomes of recanalization, reperfusion, and substantial neurological improvement, as well as symptomatic intracranial hemorrhage and 3-month disability on the modified Rankin Scale. Although no single trial prospectively demonstrated superiority or noninferiority of tenecteplase on clinical outcome, meta-analyses of these trials (1585 patients randomized) point to tenecteplase superiority in recanalization of large vessel occlusions and noninferiority in disability-free 3-month outcome, without increases in symptomatic intracranial hemorrhage or mortality. Doses of 0.25 and 0.4 mg/kg have been tested, but no advantage of the higher dose has been suggested by the results. Current clinical practice guidelines for stroke include intravenous tenecteplase at either dose as a second-tier option, with the 0.25 mg/kg dose recommended for large vessel occlusions, based on a phase 2 trial that demonstrated superior recanalization and improved 3-month outcome relative to alteplase. Ongoing randomized phase 3 trials may better define the comparative risks and benefits of tenecteplase and alteplase for stroke thrombolysis and answer questions of tenecteplase efficacy in the >4.5-hour time window, in wake-up stroke, and in combination with endovascular thrombectomy.

Quantitative Analysis of the Cerebral Vasculature on Magnetic Resonance Angiography.

The arterial connections in the Circle of Willis are a central source of collateral blood flow and play an important role in pathologies such as stroke and mental illness. Analysis of the Circle of Willis and its variants can shed light on optimal methods of diagnosis, treatment planning, surgery, and quantification of outcomes. We developed an automated, standardized, objective, and high-throughput approach for categorizing and quantifying the Circle of Willis vascular anatomy using magnetic resonance angiography images. This automated algorithm for processing of MRA images isolates and automatically identifies key features of the cerebral vasculature such as branching of the internal intracranial internal carotid artery and the basilar artery. Subsequently, physical features of the segments of the anterior cerebral artery were acquired on a sample and intra-patient comparisons were made. We demonstrate the feasibility of using our approach to automatically classify important structures of the Circle of Willis and extract biomarkers from cerebrovasculature. Automated image analysis can provide clinically-relevant vascular features such as aplastic arteries, stenosis, aneurysms, and vessel caliper for endovascular procedures. The developed algorithm could facilitate clinical studies by supporting high-throughput automated analysis of the cerebral vasculature.

Neuroimaging in Ischemic Stroke Is Different Between Men and Women in the DEFUSE 3 Cohort.

Background and Purpose- Clinical deficits from ischemic stroke are more severe in women, but the pathophysiological basis of this sex difference is unknown. Sex differences in core and penumbral volumes and their relation to outcome were assessed in this substudy of the DEFUSE 3 clinical trial (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke). Methods- DEFUSE 3 randomized patients to thrombectomy or medical management who presented 6 to 16 hours from last known well with proximal middle cerebral artery or internal carotid artery occlusion and had target core and perfusion mismatch volumes on computed tomography or magnetic resonance imaging. Using univariate and adjusted regression models, the effect of sex was assessed on prerandomization measures of core, perfusion, and mismatch volumes and hypoperfusion intensity ratio, and on core volume growth using 24-hour scans. Results- All patients were included in the analysis (n=182) with 90 men and 92 women. There was no sex difference in the site of baseline arterial occlusion. Adjusted by age, baseline National Institutes of Health Stroke Scale, baseline modified Rankin Scale score, time to randomization, and imaging modality, women had smaller core, hypoperfusion, and penumbral volumes than men. Median (interquartile range) volumes for core were 8.0 mL (1.9-18.4) in women versus 12.6 mL (2.7-29.6) in men, for Tmax>6 seconds 89.0 mL (63.8-131.7) versus 133.9 mL (87.0-175.4), and for mismatch 82.1mL (53.8-112.8) versus 108.2 (64.1-149.2). The hypoperfusion intensity ratio was lower in women, 0.31 (0.15-0.46) versus 0.39 (0.26-0.57), P=0.006, indicating better collateral circulation, which was consistent with the observed slower ischemic core growth than men within the medical group (P=0.003). Conclusions- In the large vessel ischemic stroke cohort selected for DEFUSE 3, women had imaging evidence of better collateral circulation, smaller baseline core volumes, and slower ischemic core growth. These observations suggest sex differences in hemodynamic and temporal features of anterior circulation large artery occlusions. Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT02586415.

Sex Differences in Outcome After Endovascular Stroke Therapy for Acute Ischemic Stroke.

Background and Purpose- We determined the effect of sex on outcome after endovascular stroke thrombectomy in acute ischemic stroke, including lifelong disability outcomes. Methods- We analyzed patients treated with the Solitaire stent retriever in the combined SWIFT (Solitaire FR With the Intention for Thrombectomy), STAR (Solitaire FR Thrombectomy for Acute Revascularization), and SWIFT PRIME (Solitaire FR With the Intention for Thrombectomy as Primary Endovascular Treatment) cohorts. Ordinal and logistic regression were used to examine known factors influencing outcome after endovascular stroke thrombectomy and study the effect of sex on the association between these factors and outcomes, including age and time to reperfusion. Years of optimal life after thrombectomy were defined as disability-adjusted life years and calculated by projecting disability through adjusted poststroke life expectancy by sex. Results- Among 389 patients treated with endovascular stroke thrombectomy, 55% were females, and median National Institutes of Health Stroke Scale was 17 (interquartile range, 8-28). There were no differences between females versus males in presenting deficit severity (National Institutes of Health Stroke Scale score, 17 versus 17, P=0.21), occlusion location (69% versus 64% M1, P=0.62), presenting infarct extent (Alberta Stroke Program Early CT Score 8 versus 8, P=0.24), rate of substantial reperfusion (Thrombolysis in Cerebral Infarction 2b/3, 87% versus 83%, P=0.37), onset to reperfusion time (294 versus 302 minutes, P=0.46). Despite older ages (69 versus 64, P<0.001) and higher rate of atrial fibrillation (45% versus 30%, P=0.002) for females compared with males, adjusted rates of functional independence at 90 days were similar (odds ratio, 1.0; 95% CI, 0.6-1.6). After adjusting for age at presentation and stroke severity, females had more years of optimal life (disability-adjusted life year) after endovascular stroke thrombectomy, 10.6 versus 8.5 years (P<0.001). Conclusions- Despite greater age and higher rate of atrial fibrillation, females experienced comparable functional outcomes and greater years of optimal life after intervention compared with males.

Optimal delay time to initiate anticoagulation after ischemic stroke in atrial fibrillation (START): Methodology of a pragmatic, response-adaptive, prospective randomized clinical trial.

RATIONALE: An estimated 15% of all strokes are associated with untreated atrial fibrillation. Long-term secondary stroke prevention in atrial fibrillation is anticoagulation, increasingly with non-vitamin K oral anticoagulants. The optimal time to initiate anticoagulation following an atrial fibrillation-related stroke that balances hemorrhagic conversion with recurrent stroke is not yet known. AIMS: To determine if there is an optimal delay time to initiate anticoagulation after atrial fibrillation-related stroke that optimizes the composite outcome of hemorrhagic conversion and recurrent ischemic stroke. SAMPLE SIZE ESTIMATES: The study will enroll 1500 total subjects split between a mild to moderate stroke cohort (1000) and a severe stroke cohort (500). METHODS AND DESIGN: This study is a multi-center, prospective, randomized, pragmatic, adaptive trial that randomizes subjects to four arms of time to start of anticoagulation. The four arms for mild to moderate stroke are: Day 3, Day 6, Day 10, and Day 14. The time intervals for severe stroke are: Day 6, Day 10, Day 14, and Day 21. Allocation involves a response adaptive randomization via interim analyses to favor the arms that have a better risk-benefit profile. STUDY OUTCOMES: The primary outcome event is the composite occurrence of an ischemic or hemorrhagic event within 30 days of the index stroke. Secondary outcomes are also collected at 30 and 90 days. DISCUSSION: The optimal timing of direct oral anticoagulants post-ischemic stroke requires prospective randomized testing. A pragmatically designed trial with adaptive allocation and randomization to multiple time intervals such as the START trial is best suited to answer this question in order to directly inform current practice on this question.

Neuroimaging evolution of ischemia in men and women: an observational study.

Objective: We present an exploratory study for identification of sex differences in imaging biomarkers that could further refine selection of patients for acute reperfusion therapy and trials based on sex and imaging targets. Methods: The Lesion Evolution in Stroke and Ischemia On Neuroimaging (LESION) study included consecutive acute stroke patients who underwent MRI within 24 h of time from last known well and prior to therapy. Those demonstrating a potential therapeutic target on imaging were identified by presence of: (1) arterial occlusion on angiography, (2) focal ischemic region on perfusion maps, or (3) a mismatch of perfusion versus diffusion imaging lesion size. The prevalence of imaging targets within clinically relevant time intervals was calculated for each patient and examined. The relationship of time from stroke onset to probability of detection of imaging targets was evaluated. Results: Of 7007 patients screened, of which 86.7% were scanned with MRI, 1092 patients (477/615 men/women) were included in LESION. The probability of imaging target detection was significantly different between men and women, with women more likely to present with all assessed imaging targets, odds ratios between 1.36 and 1.59, P < 0.02, adjusted for NIHSS, age, and time from last known well to MRI scan. This trend held for the entire 24-h studied. Interpretation: Women present more often with treatable ischemic stroke than men. The greater probability of potentially viable and/or treatable imaging targets in women at all time points suggests that tissue injury is slower to evolve in women.

Blood-brain barrier leakage increases with small vessel disease in acute ischemic stroke.

OBJECTIVE: In patients with acute ischemic stroke, we aimed to investigate the relation between preexisting small vessel disease (SVD) and the amount of blood-brain barrier (BBB) leakage in ischemic and nonischemic area before IV thrombolysis. METHODS: We retrospectively accessed anonymous patient-level data from the Stroke Imaging Repository and the Virtual International Stroke Trials Archive resources and included patients treated with IV thrombolysis with pretreatment MRI. We rated SVD features using validated qualitative magnetic resonance (MR) scales. Leakage of BBB was assessed with postprocessing of perfusion-weighted images. We evaluated associations between SVD features (individually and summed in a global SVD score) and BBB leakage using linear regression analysis, adjusting for major clinical confounders. RESULTS: A total of 212 patients, mean age (±SD) 69.5 years (±16.1), 102 (48%) male, had available MR before IV thrombolysis. Evidence of BBB leakage was present in 175 (80%) and 205 (94%) patients in the ischemic and nonischemic area, respectively. Lacunar infarcts (ß = 0.17, p = 0.042) were associated with BBB leakage in the ischemic area, and brain atrophy was associated with BBB leakage in both ischemic (ß = 0.20, p = 0.026) and nonischemic (ß = 0.27, p = 0.001) areas. Increasing SVD grade was independently associated with BBB leakage in both ischemic (ß = 0.26, p = 0.007) and nonischemic (ß = 0.27, p = 0.003) area. CONCLUSIONS: Global SVD burden is associated with increased BBB leakage in both acutely ischemic and nonischemic area. Our results support that SVD score has construct validity, and confirm a relation between SVD and BBB disruption also in patients with acute stroke.