Use of Artificial Intelligence in Improving Outcomes in Heart Disease: A Scientific Statement From the American Heart Association.

A major focus of academia, industry, and global governmental agencies is to develop and apply artificial intelligence and other advanced analytical tools to transform health care delivery. The American Heart Association supports the creation of tools and services that would further the science and practice of precision medicine by enabling more precise approaches to cardiovascular and stroke research, prevention, and care of individuals and populations. Nevertheless, several challenges exist, and few artificial intelligence tools have been shown to improve cardiovascular and stroke care sufficiently to be widely adopted. This scientific statement outlines the current state of the art on the use of artificial intelligence algorithms and data science in the diagnosis, classification, and treatment of cardiovascular disease. It also sets out to advance this mission, focusing on how digital tools and, in particular, artificial intelligence may provide clinical and mechanistic insights, address bias in clinical studies, and facilitate education and implementation science to improve cardiovascular and stroke outcomes. Last, a key objective of this scientific statement is to further the field by identifying best practices, gaps, and challenges for interested stakeholders.

Tenecteplase versus standard of care for minor ischaemic stroke with proven occlusion (TEMPO-2): a randomised, open label, phase 3 superiority trial.

BACKGROUND: Individuals with minor ischaemic stroke and intracranial occlusion are at increased risk of poor outcomes. Intravenous thrombolysis with tenecteplase might improve outcomes in this population. We aimed to test the superiority of intravenous tenecteplase over non-thrombolytic standard of care in patients with minor ischaemic stroke and intracranial occlusion or focal perfusion abnormality. METHODS: In this multicentre, prospective, parallel group, open label with blinded outcome assessment, randomised controlled trial, adult patients (aged ≥18 years) were included at 48 hospitals in Australia, Austria, Brazil, Canada, Finland, Ireland, New Zealand, Singapore, Spain, and the UK. Eligible patients with minor acute ischaemic stroke (National Institutes of Health Stroke Scale score 0-5) and intracranial occlusion or focal perfusion abnormality were enrolled within 12 h from stroke onset. Participants were randomly assigned (1:1), using a minimal sufficient balance algorithm to intravenous tenecteplase (0·25 mg/kg) or non-thrombolytic standard of care (control). Primary outcome was a return to baseline functioning on pre-morbid modified Rankin Scale score in the intention-to-treat (ITT) population (all patients randomly assigned to a treatment group and who did not withdraw consent to participate) assessed at 90 days. Safety outcomes were reported in the ITT population and included symptomatic intracranial haemorrhage and death. This trial is registered with ClinicalTrials.gov, NCT02398656, and is closed to accrual. FINDINGS: The trial was stopped early for futility. Between April 27, 2015, and Jan 19, 2024, 886 patients were enrolled; 369 (42%) were female and 517 (58%) were male. 454 (51%) were assigned to control and 432 (49%) to intravenous tenecteplase. The primary outcome occurred in 338 (75%) of 452 patients in the control group and 309 (72%) of 432 in the tenecteplase group (risk ratio [RR] 0·96, 95% CI 0·88-1·04, p=0·29). More patients died in the tenecteplase group (20 deaths [5%]) than in the control group (five deaths [1%]; adjusted hazard ratio 3·8; 95% CI 1·4-10·2, p=0·0085). There were eight (2%) symptomatic intracranial haemorrhages in the tenecteplase group versus two (<1%) in the control group (RR 4·2; 95% CI 0·9-19·7, p=0·059). INTERPRETATION: There was no benefit and possible harm from treatment with intravenous tenecteplase. Patients with minor stroke and intracranial occlusion should not be routinely treated with intravenous thrombolysis. FUNDING: Heart and Stroke Foundation of Canada, Canadian Institutes of Health Research, and the British Heart Foundation.

Combining Early Ischemic Change and Collateral Extent for Functional Outcomes After Endovascular Therapy: An Analysis From AcT Trial.

BACKGROUND: Early ischemic change and collateral extent are colinear with ischemic core volume (ICV). We investigated the relationship between a combined score using the Alberta Stroke Program Early Computed Tomography Score and multiphase computed tomography angiography (mCTA) collateral extent, named mCTA-ACE score, on functional outcomes in endovascular therapy-treated patients. METHODS: We performed a post hoc analysis of a subset of endovascular therapy-treated patients from the Alteplase Compared to Tenecteplase trial which was conducted between December 2019 and January 2022 at 22 centers across Canada. Ten-point mCTA collateral corresponding to M2 to M6 regions of the Alberta Stroke Program Early Computed Tomography Score grid was evaluated as 0 (poor), 1 (moderate), or 2 (normal) and additively combined with the 10-point Alberta Stroke Program Early Computed Tomography Score to produce a 20-point mCTA-ACE score. We investigated the association of mCTA-ACE score with modified Rankin Scale score ≤2 and return to prestroke level of function at 90 to 120 days using mixed-effects logistic regression. In the subset of patients who underwent baseline computed tomography perfusion imaging, we compared the mCTA-ACE score and ICV for outcome prediction. RESULTS: Among 1577 intention-to-treat population in the trial, 368 (23%; 179 men; median age, 73 years) were included, with Alberta Stroke Program Early Computed Tomography Score, mCTA collateral, and combination of both (mCTA-ACE score: median [interquartile range], 8 [7-10], 9 [8-10], and 17 [16-19], respectively). The probability of modified Rankin Scale score ≤2 and return to prestroke level of function increased for each 1-point increase in mCTA-ACE score (odds ratio, 1.16 [95% CI, 1.06-1.28] and 1.22 [95% CI, 1.06-1.40], respectively). Among 173 patients in whom computed tomography perfusion data was assessable, the mCTA-ACE score was inversely correlated with ICV (ρ=-0.46; P<0.01). The mCTA-ACE score was comparable to ICV to predict a modified Rankin Scale score ≤2 and return to prestroke level of function (C statistics 0.71 versus 0.69 and 0.68 versus 0.64, respectively). CONCLUSIONS: The mCTA-ACE score had a significant positive association with functional outcomes after endovascular therapy and had a similar predictive performance as ICV.

HERMES-24 Score Derivation and Validation for Simple and Robust Outcome Prediction After Large Vessel Occlusion Treatment.

BACKGROUND: Clinicians need simple and highly predictive prognostic scores to assist practical decision-making. We aimed to develop a simple outcome prediction score applied 24 hours after anterior circulation acute ischemic stroke treatment with endovascular thrombectomy and validate it in patients treated both with and without endovascular thrombectomy. METHODS: Using the HERMES (Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials) collaboration data set (n=1764), patients in the endovascular thrombectomy arm were divided randomly into a derivation cohort (n=430) and a validation cohort (n=441). From a set of candidate predictors, logistic regression modeling using forward variable selection was used to select a model that was both parsimonious and highly predictive for modified Rankin Scale (mRS) ≤2 at 90 days. The score was validated in validation cohort, control arm (n=893), and external validation cohorts from the ESCAPE-NA1 (Efficacy and Safety of Nerinetide for the Treatment of Acute Ischaemic Stroke; n=1066) and INTERRSeCT (Identifying New Approaches to Optimize Thrombus Characterization for Predicting Early Recanalization and Reperfusion With IV Alteplase and Other Treatments Using Serial CT Angiography; n=614). RESULTS: In the derivation cohort, we selected 2 significant predictors of mRS ≤2 (National Institutes of Health Stroke Scale score at 24 hours and age [ß-coefficient, 0.34 and 0.06]) and derived the HERMES-24 score: age (years)/10+National Institutes of Health Stroke Scale score at 24 hours. The HERMES-24 score was highly predictive for mRS ≤2 (c-statistic 0.907 [95% CI, 0.879-0.935]) in the derivation cohort. In the validation cohort and the control arm, the HERMES-24 score predicts mRS ≤2 (c-statistic, 0.914 [95% CI, 0.886-0.944] and 0.909 [95% CI, 0.887-0.930]). Observed provability of mRS ≤2 ranged between 3.1% and 3.4% when HERMES-24 score ≥25, while it ranged between 90.6% and 93.0% when HERMES-24 score <10 in the derivation cohort, validation cohort, and control arm. The HERMES-24 score also showed c-statistics of 0.894 and 0.889 for mRS ≤2 in the ESCAPE-NA1 and INTERRSeCT populations. CONCLUSIONS: The post-treatment HERMES-24 score is a simple validated score that predicts a 3-month outcome after anterior circulation large vessel occlusion stroke regardless of intervention, which helps prognostic discussion with families on day 2.

Mechanical Thrombectomy Access Score: A Systematic Review and Modified Delphi of Global Barriers to Endovascular Therapy.

BACKGROUND: The availability of mechanical thrombectomy (MT) for acute ischemic stroke is limited, and vast disparities exist between countries. We aim to create a MT access score to measure the drivers of access to help quantify and accelerate treatment worldwide. METHODS: We used a systematic review complemented by a modified Delphi method. In the first of 3 rounds, 4 independent investigators performed a systematic literature review using key search terms that drive MT access, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. In the second round, a panel of 6 anonymous international experts selected key attributes needed for scoring. In the final round, a total of 12 attributes were selected on consensus, each given a score on a 0 to 3 scale. An ultimate MT access score (range, 0-36) was proposed as a new tool to use in identifying barriers to MT access and assist in providing an initial framework for public health interventions. RESULTS: Of 2864 abstracts screened, 121 studies were included in the final systematic review. A total of 34 attributes that potentially drive MT access were initially identified. In the final round, 12 attributes were selected by the expert panel: public awareness, emergency medical services transportation, prehospital large vessel occlusion screening, interhospital transfer policy, emergency department protocols, stroke imaging protocols, emergency department stroke expertise or telestroke availability, interventionalists, MT-capable centers, device availability, and insurance coverage. These attributes were weighted as part of the final score of 0 to 36. CONCLUSIONS: The MT access score represents the first tool to quantify barriers to global MT access. Its implementation stands not just as an academic achievement but as a beacon of hope for improving stroke care and outcomes worldwide, bringing us a step closer to bridging the gap in stroke treatment disparities.

Sex-Based Analysis of Workflow and Outcomes in Acute Ischemic Stroke Patients Treated With Alteplase Versus Tenecteplase.

BACKGROUND: Understanding sex differences in stroke care is important in reducing potential disparities. Our objective was to explore sex differences in workflow efficiency, treatment efficacy, and safety in the AcT trial (Alteplase Compared to Tenecteplase). METHODS: AcT was a multicenter, registry-linked randomized noninferiority trial comparing tenecteplase (0.25 mg/kg) with alteplase (0.9 mg/kg) in acute ischemic stroke within 4.5 hours of onset. In this post hoc analysis, baseline characteristics, workflow times, successful reperfusion (extended Thrombolysis in Cerebral Infarction score ≥2b), symptomatic intracerebral hemorrhage, 90-day functional independence (modified Rankin Scale score, 0-1), and 90-day mortality were compared by sex. Mixed-effects regression analysis was used adjusting for age, stroke severity, and occlusion site for outcomes. RESULTS: Of 1577 patients treated with intravenous thrombolysis (2019-2022), 755 (47.9%) were women. Women were older (median, 77 [68-86] years in women versus 70 [59-79] years in men) and had a higher proportion of severe strokes (National Institutes of Health Stroke Scale score >15; 32.4% versus 24.9%) and large vessel occlusions (28.7% versus 21.5%) compared with men. All workflow times were comparable between sexes. Women were less likely to achieve functional independence (31.7% versus 39.8%; unadjusted relative risk, 0.80 [95% CI, 0.70-0.91]) and had higher mortality (17.7% versus 13.3%; unadjusted relative risk, 1.33 [95% CI, 1.06-1.69]). Adjusted analysis showed no difference in outcomes between sexes. CONCLUSIONS: Differences in prognostic factors of age, stroke severity, and occlusion site largely accounted for higher functional dependence and mortality in women. No sex disparities were apparent in workflow quality indicators. Given the integration of the AcT trial into clinical practice, these results provide reassurance that no major sex biases are apparent in acute stroke management throughout participating Canadian centers. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03889249.

Effect of Needle-To-Puncture Time on Reperfusion Outcome in Acute Ischemic Stroke.

INTRODUCTION: The aim of the study was to investigate the impact of time interval between start of intravenous thrombolysis (IVT) to start of endovascular thrombectomy (EVT) on stroke outcomes. METHODS: Data from the Quality Improvement and Clinical Research (QuICR) provincial stroke registry from Alberta, Canada, were used to identify stroke patients who received IVT and EVT from January 2015 to December 2019. We assessed the impact of the time interval between IVT bolus to EVT puncture (needle-to-puncture times [NPT]) on outcomes. Radiological outcomes included successful initial recanalization (revised Arterial Occlusive Lesion 2b-3), successful initial and final reperfusion (modified thrombolysis in cerebral infarction 2b-3). Clinical outcomes were 90-day modified Rankin Scale (mRS) and mortality. RESULTS: Of the 680 patients, 233 patients (median age: 73, 41% females) received IVT + EVT. Median NPT was 38 min (IQR, 24-60). Arrival during working hours was independently associated with shorter NPT (p < 0.001). Successful initial recanalization and initial and final reperfusion were observed in 12%, 10%, and 83% of patients, respectively. NPT was not associated with initial successful recanalization (OR 0.97 for every 10-min increase of NPT, 95% CI: 0.91-1.04), initial successful reperfusion (OR 1.01, 95% CI: 0.96-1.07), or final successful reperfusion (OR: 1.03, 95% CI: 0.97-1.08). Every 10-min delay in NPT was associated with lower odds of functional independence at 90 days (mRS ≤2; OR: 0.93; 95% CI, 0.88-0.97). Patients with shorter NPT (≤38 min) had lower 90-day mRS scores (median 1 vs. 3; OR: 0.54 [0.31-0.91]) and had lower mortality (6.1% vs. 21.2%; OR, 0.23 [0.10-0.57]) than the longer NPT group. CONCLUSION: Shorter NPT did not impact reperfusion outcomes but was associated with better clinical outcome.

Physician Approaches to Antithrombotic Therapies for Recently Symptomatic Carotid Stenosis.

BACKGROUND: Whereas the beneficial effect of antiplatelet therapy for recurrent stroke prevention has been well established, uncertainties remain regarding the optimal antithrombotic regimen for recently symptomatic carotid stenosis. We sought to explore the approaches of stroke physicians to antithrombotic management of patients with symptomatic carotid stenosis. METHODS: We employed a qualitative descriptive methodology to explore the decision-making approaches and opinions of physicians regarding antithrombotic regimens for symptomatic carotid stenosis. We conducted semi-structured interviews with a purposive sample of 22 stroke physicians (11 neurologists, 3 geriatricians, 5 interventional-neuroradiologists, and 3 neurosurgeons) from 16 centers on four continents to discuss symptomatic carotid stenosis management. We then conducted thematic analysis on the transcripts. RESULTS: Important themes revealed from our analysis included limitations of existing clinical trial evidence, competing surgeon versus neurologist/internist preferences, and the choice of antiplatelet therapy while awaiting revascularization. There was a greater concern for adverse events while using multiple antiplatelet agents (e.g., dual-antiplatelet therapy (DAPT)) in patients undergoing carotid endarterectomy compared to carotid artery stenting. Regional variations included more frequent use of single antiplatelet agents among European participants. Areas of uncertainty included antithrombotic management if already on an antiplatelet agent, implications of nonstenotic features of carotid disease, the role of newer antiplatelet agents or anticoagulants, platelet aggregation testing, and timing of DAPT. CONCLUSION: Our qualitative findings can help physicians critically examine the rationale underlying their own antithrombotic approaches to symptomatic carotid stenosis. Future clinical trials may wish to accommodate identified variations in practice patterns and areas of uncertainty to better inform clinical practice.

Workflow and Outcome of Thrombectomy in Late Time Window: A Pooled Multicenter Analysis.

BACKGROUND: We investigated the impact of workflow times on the outcomes of patients treated with endovascular thrombectomy (EVT) in the late time window. METHODS: Individual patients' data who underwent EVT in the late time window (onset to imaging >6 hours) were pooled from seven registries and randomized clinical trials. Multiple time intervals were analyzed. Mixed-effects logistic regression was used to estimate the likelihood of functional independence at 90 days (modified Rankin Scale 0-2). Mixed-effects negative binomial regression was used to evaluate the relationship between patient characteristics and workflow time intervals. RESULTS: 608 patients were included. The median age was 70 years (IQR: 58-71), 307 (50.5%) were female, and 310 (53.2%) had wake-up strokes. Successful reperfusion was achieved in 493 (81.2%) patients, and 262 (44.9%) achieved 90-day mRS 0-2. The estimated odds of functional independence decreased by 13% for every 30 minute delay from emergency department (ED) arrival to imaging time and by 7% from ED arrival to the end of EVT in the entire cohort. Also, the estimated odds of functional independence decreased by 33% for every 30 minute delay in the interval from arterial puncture to end of EVT, 16% in the interval from arrival in ED to end of EVT and 6% in the interval from stroke onset to end of EVT among patients who had a wake-up stroke. CONCLUSION: Faster workflow from ED arrival to end of EVT is associated with improved functional independence among stroke patients treated in the late window.

De novo formation of a carotid web in an adult: A longitudinal observation.

BACKGROUND: Carotid web is a thin shelf-like fibrointimal membrane arising from the posterior or posterolateral wall of the carotid bulb. Webs cause stroke, especially in younger adults with high risk of recurrence. METHODS: To report the first case of de-novo formation of an asymptomatic carotid web and describe longitudinal clinical-angiographic follow-up. RESULTS: A previously healthy 50-year-old White female presented with acute vestibular syndrome. Brain MRI showed no brain infarction. An arch-to-vertex CT angiogram showed normal posterior circulation, however, the left internal carotid artery bulb had a thin shelf-like projection into the lumen arising from the posterior wall of the artery - an incidental carotid web. A CT angiogram performed seven years earlier showed normal carotid arteries. The three-year angiographic follow-up showed an unchanged angiographic appearance of the carotid web. The patient preferred staying on aspirin and suffered no retinal or cerebral ischemic event during the 5-year clinic follow-up. CONCLUSION: Our case suggests de novo (acquired) formation of a carotid web in an adult. This challenges the prevailing theory that carotid web is a congenital/developmental lesion.

Cytoprotective agents in stroke: Still uncertainty in the next frontier.

INTRODUCTION: Despite substantial improvement of acute ischemic stroke (AIS) care with the advent of extended time windows for intravenous thrombolysis (IVT) and endovascular thrombectomy (EVT), a substantial portion of patients still suffer poor outcomes. Additional adjuvant therapies are needed but pharmacologic interactions among therapies may dictate how they could be used. We conducted a survey to determine physician decision-making regarding the use of cytoprotective agents in patients presenting with AIS. METHODS: The survey was structured, web-based, anonymous, and invite-only among physicians across the world treating patients presenting with AIS. Respondents were asked about the use of a hypothetical cytoprotective agent (that provided an added 10% benefit) in the context of a treatment interaction with IVT or its timing in relation to IVT. RESULTS: A total of 282 stroke physicians (74.9% males, mean age 46 years) participated in the survey. When the respondent could give both the cytoprotective agent and IVT with no treatment interaction, 177 (78.0%) chose to administer both. In the presence of treatment interaction, 88 (38.3%) would withhold IVT, 83 (36.1%) would withhold the cytoprotective agent and 56 (24.4%) were uncertain. Lastly, 111 (48.9%) were willing to administer the cytoprotective agent if it meant a necessary 10-minute delay in IVT administration. CONCLUSIONS: Pharmacologic interactions result in major uncertainty about cytoprotective treatment choices.

Distal Embolization in Relation to Radiological Thrombus Characteristics, Treatment Details, and Functional Outcome.

BACKGROUND: Distal embolization (DE) is a common complication of endovascular treatment (EVT). We investigated the association of radiological thrombus characteristics and treatment details with DE. METHODS: Patients with thin-slice (≤2.5 mm) baseline noncontrast computed tomography and computed tomography angiography from the ESCAPE-NA1 trial (Efficacy and Safety of Nerinetide for the Treatment of Acute Ischemic Stroke) were included. Thrombus annotation was performed manually on coregistered scans by experienced readers. We assessed thrombus location, distance from internal carotid artery terminus, length, perviousness, absolute attenuation, and hyperdense artery sign. In addition, we evaluated balloon guide catheter use during EVT, first-line EVT approach, the number of thrombectomy passes, and prior intravenous thrombolysis administration. DE was defined as the occurrence of emboli distal to the target artery or in new territories during EVT. The association between thrombus characteristics, treatment details, and DE was evaluated using descriptive statistics and multivariable mixed-effects logistic regression, resulting in adjusted odds ratios (aOR) with 95% CI. Interaction between IVT and radiological thrombus characteristics was assessed by adding interaction terms in separate models. RESULTS: In total, 496 out of 1105 (44.9%) ESCAPE-NA1 patients were included. DE was detected in 251 out of 496 patients (50.6%). Patients with DE had longer thrombi (median, 28.5 [interquartile range, 20.8-42.3] mm versus 24.4 [interquartile range, 17.1-32.4] mm; P<0.01). There were no statistically significant differences in the other thrombus characteristics. Factors associated with DE were thrombus length (aOR, 1.02 [95% CI, 1.01-1.04]), balloon guide catheter use (aOR, 0.49 [95% CI, 0.29-0.85]), and number of passes (aOR, 1.24 [95% CI, 1.04-1.47]). In patients with hyperdense artery sign, IVT was associated with reduced odds of DE (aOR, 0.55 [95% CI, 0.31-0.97]), P for interaction=0.04. CONCLUSIONS: DE was associated with longer thrombi, no balloon guide catheter use, and more EVT passes. IVT was associated with a reduced risk of DE in patients with hyperdense artery sign. These findings may support treatment decisions on IVT and EVT approaches.

Effect of Time to Thrombolysis on Clinical Outcomes in Patients With Acute Ischemic Stroke Treated With Tenecteplase Compared to Alteplase: Analysis From the AcT Randomized Controlled Trial.

BACKGROUND: The AcT (Alteplase Compared to Tenecteplase) randomized controlled trial showed that tenecteplase is noninferior to alteplase in treating patients with acute ischemic stroke within 4.5 hours of symptom onset. The effect of time to treatment on clinical outcomes with alteplase is well known; however, the nature of this relationship is yet to be described with tenecteplase. We assessed whether the association of time to thrombolysis treatment with clinical outcomes in patients with acute ischemic stroke differs by whether they receive intravenous tenecteplase versus alteplase. METHODS: Patients included were from AcT, a pragmatic, registry-linked, phase 3 randomized controlled trial comparing intravenous tenecteplase to alteplase in patients with acute ischemic stroke. Eligible patients were >18 years old, with disabling neurological deficits, presenting within 4.5 hours of symptom onset, and eligible for thrombolysis. Primary outcome was modified Rankin Scale score 0 to 1 at 90 days. Safety outcomes included 24-hour symptomatic intracerebral hemorrhage and 90-day mortality rates. Mixed-effects logistic regression was used to assess the following: (a) the association of stroke symptom onset to needle time; (b) door (hospital arrival) to needle time with outcomes; and (c) if these associations were modified by type of thrombolytic administered (tenecteplase versus alteplase), after adjusting for age, sex, baseline stroke severity, and site of intracranial occlusion. RESULTS: Of the 1538 patients included in this analysis, 1146 (74.5%; 591 tenecteplase and 555 alteplase) presented within 3 hours versus 392 (25.5%; 196: TNK and 196 alteplase) who presented within 3 to 4.5 hours of symptom onset. Baseline patient characteristics in the 0 to 3 hours versus 3- to 4.5-hour time window were similar, except patients in the 3- to 4.5-hour window had lower median baseline National Institutes of Health Stroke Severity Scale (10 versus 7, respectively) and lower proportion of patients with large vessel occlusion on baseline CT angiography (26.9% versus 18.7%, respectively). Type of thrombolytic agent (tenecteplase versus alteplase) did not modify the association between continuous onset to needle time (Pinteraction=0.161) or door-to-needle time (Pinteraction=0.972) and primary clinical outcome. Irrespective of the thrombolytic agent used, each 30-minute reduction in onset to needle time was associated with a 1.8% increase while every 10 minutes reduction in door-to-needle time was associated with a 0.2% increase in the probability of achieving 90-day modified Rankin Scale score 0 to 1, respectively. CONCLUSIONS: The effect of time to tenecteplase administration on clinical outcomes is like that of alteplase, with faster administration resulting in better clinical outcomes. REGISTRATION: URL: https://classic. CLINICALTRIALS: gov; Unique identifier: NCT03889249.

Thrombectomy for anterior circulation stroke beyond 6 h from time last known well (AURORA): a systematic review and individual patient data meta-analysis.

BACKGROUND: Trials examining the benefit of thrombectomy in anterior circulation proximal large vessel occlusion stroke have enrolled patients considered to have salvageable brain tissue, who were randomly assigned beyond 6 h and (depending on study protocol) up to 24 h from time last seen well. We aimed to estimate the benefit of thrombectomy overall and in prespecified subgroups through individual patient data meta-analysis. METHODS: We did a systematic review and individual patient data meta-analysis between Jan 1, 2010, and March 1, 2021, of randomised controlled trials of endovascular stroke therapy. In the Analysis Of Pooled Data From Randomized Studies Of Thrombectomy More Than 6 Hours After Last Known Well (AURORA) collaboration, the primary outcome was disability on the modified Rankin Scale (mRS) at 90 days, analysed by ordinal logistic regression. Key safety outcomes were symptomatic intracerebral haemorrhage and mortality within 90 days. FINDINGS: Patient level data from 505 individuals (n=266 intervention, n=239 control; mean age 68·6 years [SD 13·7], 259 [51·3%] women) were included from six trials that met inclusion criteria of 17 screened published randomised trials. Primary outcome analysis showed a benefit of thrombectomy with an unadjusted common odds ratio (OR) of 2·42 (95% CI 1·76-3·33; p<0·0001) and an adjusted common OR (for age, gender, baseline stroke severity, extent of infarction on baseline head CT, and time from onset to random assignment) of 2·54 (1·83-3·54; p<0·0001). Thrombectomy was associated with higher rates of independence in activities of daily living (mRS 0-2) than best medical therapy alone (122 [45·9%] of 266 vs 46 [19·3%] of 238; p<0·0001). No significant difference between intervention and control groups was found when analysing either 90-day mortality (44 [16·5%] of 266 vs 46 [19·3%] of 238) or symptomatic intracerebral haemorrhage (14 [5·3%] of 266 vs eight [3·3%] of 239). No heterogeneity of treatment effect was noted across subgroups defined by age, gender, baseline stroke severity, vessel occlusion site, baseline Alberta Stroke Program Early CT Score, and mode of presentation; treatment effect was stronger in patients randomly assigned within 12-24 h (common OR 5·86 [95% CI 3·14-10·94]) than those randomly assigned within 6-12 h (1·76 [1·18-2·62]; pinteraction=0·0087). INTERPRETATION: These findings strengthen the evidence for benefit of endovascular thrombectomy in patients with evidence of reversible cerebral ischaemia across the 6-24 h time window and are relevant to clinical practice. Our findings suggest that in these patients, thrombectomy should not be withheld on the basis of mode of presentation or of the point in time of presentation within the 6-24 h time window. FUNDING: Stryker Neurovascular.

Intravenous tenecteplase compared with alteplase for acute ischaemic stroke in Canada (AcT): a pragmatic, multicentre, open-label, registry-linked, randomised, controlled, non-inferiority trial.

BACKGROUND: Intravenous thrombolysis with alteplase bolus followed by infusion is a global standard of care for patients with acute ischaemic stroke. We aimed to determine whether tenecteplase given as a single bolus might increase reperfusion compared with this standard of care. METHODS: In this multicentre, open-label, parallel-group, registry-linked, randomised, controlled trial (AcT), patients were enrolled from 22 primary and comprehensive stroke centres across Canada. Patients were eligible for inclusion if they were aged 18 years or older, with a diagnosis of ischaemic stroke causing disabling neurological deficit, presenting within 4·5 h of symptom onset, and eligible for thrombolysis per Canadian guidelines. Eligible patients were randomly assigned (1:1), using a previously validated minimal sufficient balance algorithm to balance allocation by site and a secure real-time web-based server, to either intravenous tenecteplase (0·25 mg/kg to a maximum of 25 mg) or alteplase (0·9 mg/kg to a maximum of 90mg; 0·09 mg/kg as a bolus and then a 60 min infusion of the remaining 0·81 mg/kg). The primary outcome was the proportion of patients who had a modified Rankin Scale (mRS) score of 0-1 at 90-120 days after treatment, assessed via blinded review in the intention-to-treat (ITT) population (ie, all patients randomly assigned to treatment who did not withdraw consent). Non-inferiority was met if the lower 95% CI of the difference in the proportion of patients who met the primary outcome between the tenecteplase and alteplase groups was more than -5%. Safety was assessed in all patients who received any of either thrombolytic agent and who were reported as treated. The trial is registered with ClinicalTrials.gov, NCT03889249, and is closed to accrual. FINDINGS: Between Dec 10, 2019, and Jan 25, 2022, 1600 patients were enrolled and randomly assigned to tenecteplase (n=816) or alteplase (n=784), of whom 1577 were included in the ITT population (n=806 tenecteplase; n=771 alteplase). The median age was 74 years (IQR 63-83), 755 (47·9%) of 1577 patients were female and 822 (52·1%) were male. As of data cutoff (Jan 21, 2022), 296 (36·9%) of 802 patients in the tenecteplase group and 266 (34·8%) of 765 in the alteplase group had an mRS score of 0-1 at 90-120 days (unadjusted risk difference 2·1% [95% CI - 2·6 to 6·9], meeting the prespecified non-inferiority threshold). In safety analyses, 27 (3·4%) of 800 patients in the tenecteplase group and 24 (3·2%) of 763 in the alteplase group had 24 h symptomatic intracerebral haemorrhage and 122 (15·3%) of 796 and 117 (15·4%) of 763 died within 90 days of starting treatment INTERPRETATION: Intravenous tenecteplase (0·25 mg/kg) is a reasonable alternative to alteplase for all patients presenting with acute ischaemic stroke who meet standard criteria for thrombolysis. FUNDING: Canadian Institutes of Health Research, Alberta Strategy for Patient Oriented Research Support Unit.

Tmax Volumes Predict Final Infarct Size and Functional Outcome in Ischemic Stroke Patients Receiving Endovascular Treatment.

OBJECTIVE: The objective of this paper was to explore the utility of time to maximum concentration (Tmax )-based target mismatch on computed tomography perfusion (CTP) in predicting radiological and clinical outcomes in patients with acute ischemic stroke (AIS) with anterior circulation large vessel occlusion (LVO) selected for endovascular treatment (EVT). METHODS: Patients with AIS underwent CTP within 24 hours from onset followed by EVT. Critically hypoperfused tissue and ischemic core volumes were automatically calculated using Tmax thresholds >9.5 seconds and >16 seconds, respectively. The difference between Tmax > 9.5 seconds and Tmax > 16 seconds volumes and the ratio between Tmax > 9.5 seconds and Tmax > 16 seconds volumes were considered ischemic penumbra and Tmax mismatch ratio, respectively. Final infarct volume (FIV) was measured on follow-up non-contrast computed tomography (CT) at 24 hours. Favorable clinical outcome was defined as 90-day modified Rankin Scale 0 to 2. Predictors of FIV and outcome were assessed with multivariable logistic regression. Optimal Tmax volumes for identification of good outcome was defined using receiver operating curves. RESULTS: A total of 393 patients were included, of whom 298 (75.8%) achieved successful recanalization and 258 (65.5%) achieved good outcome. In multivariable analyses, all Tmax parameters were independent predictors of FIV and outcome. Tmax  > 16 seconds volume had the strongest association with FIV (beta coefficient = 0.596 p <0.001) and good outcome (odds ratio [OR] = 0.96 per 1 ml increase, 95% confidence interval [CI] = 0.95-0.97, p < 0.001). Tmax  > 16 seconds volume had the highest discriminative ability for good outcome (area under the curve [AUC] = 0.88, 95% CI = 0.842-0.909). A Tmax  > 16 seconds volume of ≤67 ml best identified subjects with favorable outcome (sensitivity = 0.91 and specificity = 0.73). INTERPRETATION: Tmax target mismatch predicts radiological and clinical outcomes in patients with AIS with LVO receiving EVT within 24 hours from onset. ANN NEUROL 2022;91:878-888.

Recanalization and Functional Outcome in Patients with Cervico-cephalic Arterial Dissections.

BACKGROUND: Cervico-cephalic arterial dissections (CeAD) are an important cause of stroke in young patients. This study aimed to determine the frequency and predictors of recanalization in spontaneous CeAD and to study the effect of recanalization on functional outcomes. METHODS: We identified patients presenting with acute ischemic stroke secondary to CeAD from the CT angiography (CTA) database of the Calgary Stroke Program. Dissections were diagnosed based on standard clinical and imaging findings. At the discretion of treating stroke Neurologists, the patients were either treated with single antiplatelet or dual antiplatelet or triple therapy. Follow-up imaging with CTA, magnetic resonance imaging, and DSA was completed, and a Modified Rankin scale (mRS) was performed to determine the outcome. RESULTS: Fifty-six patients with CeAdD were studied. Thirty-four patients (18 VAD; vertebral artery dissection and 16 CAD; carotid artery dissection) were followed up for recanalization. Complete recanalization was observed in 27 subjects; 13 patients with VAD recanalized in comparison to 14 with CAD (p = 0.40). All non-recanalized patients had hypertension. A good clinical outcome (mRS ≤ 2) was observed in 47 patients. Interestingly, the likelihood of a good neurological outcome was not influenced by recanalization status. There was no difference in clinical outcome for different sites in VAD, whereas patients with intracranial CAD had severe strokes (NIHSS > 21). CONCLUSIONS: CeAD has good recanalization rates and neurological outcomes, with recanalization seen even in vessels with initial complete occlusion. The presence of hypertension may influence recanalization. The efficacy of dual antiplatelets and heparin for early recanalization needs to be assessed in future clinical trials.

Vertebral to Basilar Thrombus Migration Post Intravenous Thrombolysis.

Recombinant tissue plasminogen activator improves outcomes in acute ischemic stroke. Alteplase may result in thrombus migration (TM) distally to a critical arterial supply that can worsen perfusion to eloquent brain tissue. Alteplase-related stroke recanalization and clot migration in vertebral artery (VA) occlusion whereby the clot migrates to the basilar artery (BA) may be harmful. We identified seven subjects with isolated symptomatic vertebral occlusion. Two cases suffered early neurologic deterioration due to TM from VA to BA following alteplase. Precautionary transfer to thrombectomy centers may be warranted in alteplase-treated symptomatic VA occlusions in case of migration to basilar occlusion.

Prevalence of high-risk aortic arch atherosclerosis features on computed tomography angiography in embolic stroke of undetermined source.

INTRODUCTION: Embolic stroke of undetermined source (ESUS) comprises a heterogenous group. There is a need to further identify etiologies within this group to guide management strategies. We examined the prevalence of aortic arch atherosclerosis (AAA) on CT angiography (CTA) in patients with embolic stroke of undetermined source (ESUS) to characterize high-risk plaque features. METHODS: All patients from two prospective multicenter acute ischemic stroke studies (INTERRSeCT and PRove-IT) were included if the CTA adequately imaged the proximal aortic arch and the stroke etiology was recorded. Three readers blinded to stroke etiology analyzed the following AAA plaque features on baseline CTA at the time of stroke: 1) thickness in millimetres (mm); 2) morphology (none, smooth, ulcerated, or protruding); 3) location within the aortic arch (proximal, transverse, or distal); and 4) calcification (none, single small, multiple small, single large, or diffuse extensive). RESULTS: We included 1063 patients, of which 293 (27.6%) had ESUS (mean age 67.5 years; 46.4% men; median NIHSS 12; 80.6% large vessel occlusion). Mean AAA thickness was significantly larger in ESUS patients (3.8 mm) compared to non-ESUS patients (3.0 mm; p<0.0001) and to a subgroup of patients with large artery atherosclerosis (2.9 mm; p=0.003). ESUS patients had a significantly higher proportion of ulcerated or protruding plaques (17.4% vs 10.3%; risk ratio 1.7, 95% C.I. 1.2-2.4, p=0.002). The location of AAA in the ESUS group was the ascending aorta in 37.9%, transverse arch in 42.3%, and descending aorta in 84.6%. Although AAA was mostly located in the distal aortic arch, ulcerated or protruding plaques were least common in the distal arch (p=0.002). There was no difference between ESUS and non-ESUS patients in plaque location (p=0.23) or calcification grade (p=0.092). CONCLUSION: ESUS patients in our study had thicker AAA and a higher prevalence of ulcerated or protruding plaques located more proximally within the aortic arch. High-risk plaque features may suggest a causal role of AAA in the ESUS population with visible intracranial occlusions.

Radiographic Characteristics of Mild Ischemic Stroke Patients With Visible Intracranial Occlusion: The INTERRSeCT Study.

BACKGROUND AND PURPOSE: Early neurological deterioration occurs in one-third of mild strokes primarily due to the presence of a relevant intracranial occlusion. We studied vascular occlusive patterns, thrombus characteristics, and recanalization rates in these patients. METHODS: Among patients enrolled in INTERRSeCT (Identifying New Approaches to Optimize Thrombus Characterization for Predicting Early Recanalization and Reperfusion With IV Alteplase and Other Treatments Using Serial CT Angiography), a multicenter prospective study of acute ischemic strokes with a visible intracranial occlusion, we compared characteristics of mild (National Institutes of Health Stroke Scale score, ≤5) to moderate/severe strokes. RESULTS: Among 575 patients, 12.9% had a National Institutes of Health Stroke Scale score ≤5 (median age, 70.5 [63-79]; 58% male; median National Institutes of Health Stroke Scale score, 4 [2-4]). Demographics and vascular risk factors were similar between the two groups. As compared with those with a National Institutes of Health Stroke Scale score >5, mild patients had longer symptom onset to assessment times (onset to computed tomography [240 versus 167 minutes] and computed tomography angiography [246 versus 172 minutes]), more distal occlusions (M3, anterior cerebral artery and posterior cerebral artery; 22% versus 6%), higher clot burden score (median, 9 [6-9] versus 6 [4-9]), similar favorable thrombus permeability (residual flow grades I-II, 21% versus 19%), higher collateral flow (9.1 versus 7.6), and lower intravenous alteplase treatment rates (55% versus 85%). Mild patients were more likely to recanalize (revised arterial occlusion scale score 2b/3, 45%; 49% with alteplase) compared with moderate/severe strokes (26%; 29% with alteplase). In an adjusted model for sex, alteplase, residual flow, and time between the two vessel imagings, intravenous alteplase use (odds ratio, 3.80 [95% CI, 1.11-13.00]) and residual flow grade (odds ratio, 8.70 [95% CI, 1.26-60.13]) were associated with successful recanalization among mild patients. CONCLUSIONS: Mild strokes with visible intracranial occlusions have different vascular occlusive patterns but similar thrombus permeability compared with moderate/severe strokes. Higher thrombus permeability and alteplase use were associated with successful recanalization, although the majority do not recanalize. Randomized controlled trials are needed to assess the efficacy of new thrombolytics and endovascular therapy in this population.