Tenecteplase for Ischemic Stroke at 4.5 to 24 Hours without Thrombectomy.

BACKGROUND: Tenecteplase is an effective thrombolytic agent for eligible patients with stroke who are treated within 4.5 hours after the onset of stroke. However, data regarding the effectiveness of tenecteplase beyond 4.5 hours are limited. METHODS: In a trial conducted in China, we randomly assigned patients with large-vessel occlusion of the middle cerebral artery or internal carotid artery who had salvageable brain tissue as identified on perfusion imaging and who did not have access to endovascular thrombectomy to receive tenecteplase (at a dose of 0.25 mg per kilogram of body weight; maximum dose, 25 mg) or standard medical treatment 4.5 to 24 hours after the time that the patient was last known to be well (including after stroke on awakening and unwitnessed stroke). The primary outcome was the absence of disability, which was defined as a score of 0 or 1 on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability), at day 90. The key safety outcomes were symptomatic intracranial hemorrhage and death. RESULTS: A total of 516 patients were enrolled; 264 were randomly assigned to receive tenecteplase and 252 to receive standard medical treatment. Less than 2% of the patients (4 in the tenecteplase group and 5 in the standard-treatment group) underwent rescue endovascular thrombectomy. Treatment with tenecteplase resulted in a higher percentage of patients with a modified Rankin scale score of 0 or 1 at 90 days than standard medical treatment (33.0% vs. 24.2%; relative rate, 1.37; 95% confidence interval, 1.04 to 1.81; P = 0.03). Mortality at 90 days was 13.3% with tenecteplase and 13.1% with standard medical treatment, and the incidence of symptomatic intracranial hemorrhage within 36 hours after treatment was 3.0% and 0.8%, respectively. CONCLUSIONS: In this trial involving Chinese patients with ischemic stroke due to large-vessel occlusion, most of whom did not undergo endovascular thrombectomy, treatment with tenecteplase administered 4.5 to 24 hours after stroke onset resulted in less disability and similar survival as compared with standard medical treatment, and the incidence of symptomatic intracranial hemorrhage appeared to be higher. (Funded by the National Natural Science Foundation of China and others; TRACE-III ClinicalTrials.gov number, NCT05141305.).

Trial of Endovascular Thrombectomy for Large Ischemic Strokes.

BACKGROUND: Trials of the efficacy and safety of endovascular thrombectomy in patients with large ischemic strokes have been carried out in limited populations. METHODS: We performed a prospective, randomized, open-label, adaptive, international trial involving patients with stroke due to occlusion of the internal carotid artery or the first segment of the middle cerebral artery to assess endovascular thrombectomy within 24 hours after onset. Patients had a large ischemic-core volume, defined as an Alberta Stroke Program Early Computed Tomography Score of 3 to 5 (range, 0 to 10, with lower scores indicating larger infarction) or a core volume of at least 50 ml on computed tomography perfusion or diffusion-weighted magnetic resonance imaging. Patients were assigned in a 1:1 ratio to endovascular thrombectomy plus medical care or to medical care alone. The primary outcome was the modified Rankin scale score at 90 days (range, 0 to 6, with higher scores indicating greater disability). Functional independence was a secondary outcome. RESULTS: The trial was stopped early for efficacy; 178 patients had been assigned to the thrombectomy group and 174 to the medical-care group. The generalized odds ratio for a shift in the distribution of modified Rankin scale scores toward better outcomes in favor of thrombectomy was 1.51 (95% confidence interval [CI], 1.20 to 1.89; P<0.001). A total of 20% of the patients in the thrombectomy group and 7% in the medical-care group had functional independence (relative risk, 2.97; 95% CI, 1.60 to 5.51). Mortality was similar in the two groups. In the thrombectomy group, arterial access-site complications occurred in 5 patients, dissection in 10, cerebral-vessel perforation in 7, and transient vasospasm in 11. Symptomatic intracranial hemorrhage occurred in 1 patient in the thrombectomy group and in 2 in the medical-care group. CONCLUSIONS: Among patients with large ischemic strokes, endovascular thrombectomy resulted in better functional outcomes than medical care but was associated with vascular complications. Cerebral hemorrhages were infrequent in both groups. (Funded by Stryker Neurovascular; SELECT2 ClinicalTrials.gov number, NCT03876457.).

Endovascular thrombectomy plus medical care versus medical care alone for large ischaemic stroke: 1-year outcomes of the SELECT2 trial.

BACKGROUND: Multiple randomised trials have shown efficacy and safety of endovascular thrombectomy in patients with large ischaemic stroke. The aim of this study was to evaluate long-term (ie, at 1 year) evidence of benefit of thrombectomy for these patients. METHODS: SELECT2 was a phase 3, open-label, international, randomised controlled trial with blinded endpoint assessment, conducted at 31 hospitals in the USA, Canada, Spain, Switzerland, Australia, and New Zealand. Patients aged 18-85 years with ischaemic stroke due to proximal occlusion of the internal carotid artery or of the first segment of the middle cerebral artery, showing large ischaemic core on non-contrast CT (Alberta Stroke Program Early Computed Tomographic Score of 3-5 [range 0-10, with lower values indicating larger infarctions]) or measuring 50 mL or more on CT perfusion and MRI, were randomly assigned, within 24 h of ischaemic stroke onset, to thrombectomy plus medical care or to medical care alone. The primary outcome for this analysis was the ordinal modified Rankin Scale (range 0-6, with higher scores indicating greater disability) at 1-year follow-up in an intention-to-treat population. The trial is registered at ClinicalTrials.gov (NCT03876457) and is completed. FINDINGS: The trial was terminated early for efficacy at the 90-day follow-up after 352 patients had been randomly assigned (178 to thrombectomy and 174 to medical care only) between Oct 11, 2019, and Sept 9, 2022. Thrombectomy significantly improved the 1-year modified Rankin Scale score distribution versus medical care alone (Wilcoxon-Mann-Whitney probability of superiority 0·59 [95% CI 0·53-0·64]; p=0·0019; generalised odds ratio 1·43 [95% CI 1·14-1·78]). At the 1-year follow-up, 77 (45%) of 170 patients receiving thrombectomy had died, compared with 83 (52%) of 159 patients receiving medical care only (1-year mortality relative risk 0·89 [95% CI 0·71-1·11]). INTERPRETATION: In patients with ischaemic stroke due to a proximal occlusion and large core, thrombectomy plus medical care provided a significant functional outcome benefit compared with medical care alone at 1-year follow-up. FUNDING: Stryker Neurovascular.

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.

Comparison of Perfusion Imaging Definitions of the No-Reflow Phenomenon after Thrombectomy-What Is the Best Perfusion Imaging Definition?

The no-reflow phenomenon is a potential contributor to poor outcome despite successful thrombectomy. There are multiple proposed imaging-based definitions of no-reflow leading to wide variations in reported prevalence. We investigated the agreement between existing imaging definitions and compared the characteristics and outcomes of patients identified as having no-reflow. METHODS: We performed an external validation of 4 existing published definitions of no-reflow in thrombectomy patients with extended Thrombolysis in Cerebral Infarction scale 2c to 3 (eTICI2c-3) angiographic reperfusion who underwent 24-hour perfusion imaging from 2 international randomized controlled trials (EXTEND-IA TNK part-1 and 2) and a multicenter prospective observational study. Receiver-operating-characteristic and Bayesian-information-criterion (BIC) analyses were performed with the outcome variable being dependent-or-dead at 90-days (modified Rankin Score [mRS] ≥3). RESULTS: Of 131 patients analyzed, the prevalence of no-reflow significantly varied between definitions (0.8-22.1%; p < 0.001). There was poor agreement between definitions (kappa 5/6 comparisons <0.212). Among patients with no-reflow according to at least 1 definition, there were significant differences between definitions in the intralesional interside differences in cerebral blood flow (CBF) (p = 0.006), cerebral blood volume (CBV) (p < 0.001), and mean-transit-time (MTT) (p = 0.005). No-reflow defined by 3 definitions was associated with mRS ≥3 at 90 days. The definition of >15% CBV or CBF asymmetry was the only definition that improved model fit on BIC analysis (ΔBIC = -8.105) and demonstrated an association between no-reflow and clinical outcome among patients with eTICI3 reperfusion. CONCLUSIONS: Existing imaging definitions of no-reflow varied significantly in prevalence and post-treatment perfusion imaging profile, potentially explaining the variable prevalence of no-reflow reported in literature. The definition of >15% CBV or CBF asymmetry best discriminated for functional outcome at 90 days, including patients with eTICI3 reperfusion. ANN NEUROL 2024.

Tenecteplase versus alteplase in acute ischaemic cerebrovascular events (TRACE-2): a phase 3, multicentre, open-label, randomised controlled, non-inferiority trial.

BACKGROUND: There is increasing interest in replacing alteplase with tenecteplase as the preferred thrombolytic treatment for patients with acute ischaemic stroke. We aimed to establish the non-inferiority of tenecteplase to alteplase for these patients. METHODS: In this multicentre, prospective, open-label, blinded-endpoint, randomised controlled, non-inferiority trial, adults with an acute ischaemic stroke who were eligible for standard intravenous thrombolysis but ineligible for endovascular thrombectomy were enrolled from 53 centres in China and randomly assigned (1:1) to receive intravenous tenecteplase (0·25 mg/kg, maximum dose of 25 mg) or intravenous alteplase (0·9 mg/kg, maximum dose of 90 mg). Participants had to be able to receive treatment within 4·5 h of stroke, have a modified Rankin Scale (mRS) score of no more than 1 before enrolment, and have a National Institutes of Health Stroke Scale score of 5-25. Patients and treating clinicians were not masked to group assignment; clinicians evaluating outcomes were masked to treatment type. The primary efficacy outcome was the proportion of participants who had a mRS score of 0-1 at 90 days, assessed in the modified intention-to-treat population (all randomly assigned participants who received the allocated thrombolytic), with a non-inferiority margin of 0·937 for the risk ratio (RR). The primary safety outcome was symptomatic intracranial haemorrhage within 36 h, assessed in all participants who received study drug and had a safety assessment available. The trial is registered with ClinicalTrials.gov, NCT04797013, and has been completed. FINDINGS: Between June 12, 2021, and May 29, 2022, 1430 participants were enrolled and randomly assigned to tenecteplase (n=716) or alteplase (n=714). Six patients assigned to tenecteplase and seven to alteplase did not receive study product, and five participants in the tenecteplase group and 11 in the alteplase group were lost to follow-up at 90 days. The primary outcome in the modified intention-to-treat population occurred in 439 (62%) of 705 in the tenecteplase group versus 405 (58%) of 696 in the alteplase group (RR 1·07, 95% CI 0·98-1·16). The lower limit of the RR's 95% CI was greater than the non-inferiority margin. Symptomatic intracranial haemorrhage within 36 h was observed in 15 (2%) of 711 in the tenecteplase group and 13 (2%) of 706 in the alteplase group (RR 1·18, 95% CI 0·56-2·50). Mortality within 90 days occurred in 46 (7%) individuals in the tenecteplase group versus 35 (5%) in the alteplase group (RR 1·31, 95% CI 0·86-2·01). INTERPRETATION: Tenecteplase was non-inferior to alteplase in people with ischaemic stroke who were eligible for standard intravenous thrombolytic but ineligible for or refused endovascular thrombectomy. FUNDING: National Science and Technology Major Project, Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences, National Natural Science Foundation of China, and China Shijiazhuang Pharmaceutical Company Recomgen Pharmaceutical (Guangzhou).

Tenecteplase Improves Reperfusion across Time in Large Vessel Stroke.

OBJECTIVE: Tenecteplase improves reperfusion compared to alteplase in patients with large vessel occlusions. To determine whether this improvement varies across the spectrum of thrombolytic agent to reperfusion assessment times, we performed a comparative analysis of tenecteplase and alteplase reperfusion rates. METHODS: Patients with large vessel occlusion and treatment with thrombolysis were pooled from the Melbourne Stroke Registry, and the EXTEND-IA and EXTEND-IA TNK trials. The primary outcome, thrombolytic-induced reperfusion, was defined as the absence of retrievable thrombus or >50% reperfusion at imaging reassessment. We compared the treatment effect of tenecteplase and alteplase, accounting for thrombolytic to assessment exposure times, via Poisson modeling. We compared 90-day outcomes of patients who achieved reperfusion with a thrombolytic to patients who achieved reperfusion via endovascular therapy using ordinal logistic regression. RESULTS: Among 893 patients included in the primary analysis, thrombolytic-induced reperfusion was observed in 184 (21%) patients. Tenecteplase was associated with higher rates of reperfusion (adjusted incidence rate ratio [aIRR] = 1.50, 95% confidence interval [CI] = 1.09-2.07, p = 0.01). Findings were consistent in patient subgroups with first segment (aIRR = 1.41, 95% CI = 0.93-2.14) and second segment (aIRR = 2.07, 95% CI = 0.98-4.37) middle cerebral artery occlusions. Increased thrombolytic to reperfusion assessment times were associated with reperfusion (tenecteplase: adjusted risk ratio [aRR] = 1.08 per 15 minutes, 95% CI = 1.04-1.13 vs alteplase: aRR = 1.06 per 15 minutes, 95% CI = 1.00-1.13). No significant treatment-by-time interaction was observed (p = 0.87). Reperfusion via thrombolysis was associated with improved 90-day modified Rankin Scale scores (adjusted common odds ratio = 2.15, 95% CI = 1.54-3.01) compared to patients who achieved reperfusion following endovascular therapy. INTERPRETATION: Tenecteplase, compared to alteplase, increases prethrombectomy reperfusion, regardless of the time from administration to reperfusion assessment. Prethrombectomy reperfusion is associated with better clinical outcomes. ANN NEUROL 2023;93:489-499.

Iron changes within infarct tissue in ischemic stroke patients after successful reperfusion quantified using QSM.

PURPOSE: For nearly half of patients who undergo Endovascular Thrombectomy following ischemic stroke, successful recanalisation does not guarantee a good outcome. Understanding the underlying tissue changes in the infarct tissue with the help of biomarkers specific to ischemic stroke could offer valuable insights for better treatment and patient management decisions. Using quantitative susceptibility mapping (QSM) MRI to measure cerebral iron concentration, this study aims to track the progression of iron within the infarct lesion after successful reperfusion. METHODS: In a prospective study of 87 ischemic stroke patients, successfully reperfused patients underwent MRI scans at 24-to-72 h and 3 months after reperfusion. QSM maps were generated from gradient-echo MRI images. QSM values, measured in parts per billion (ppb), were extracted from ROIs defining the infarct and mirror homolog in the contralateral hemisphere and were compared cross-sectionally and longitudinally. RESULTS: QSM values in the infarct ROIs matched those of the contralateral ROIs at 24-to-72 h, expressed as median (interquartile range) ppb [0.71(-7.67-10.09) vs. 2.20(-10.50-14.05) ppb, p = 0.55], but were higher at 3 months [10.68(-2.30-21.10) vs. -1.27(-12.98-9.82) ppb, p < 0.001]. The infarct QSM values at 3 months were significantly higher than those at 24-to-72 h [10.41(-2.50-18.27) ppb vs. 1.68(-10.36-12.25) ppb, p < 0.001]. Infarct QSM at 24-to-72 h and patient outcome measured at three months did not demonstrate a significant association. CONCLUSION: Following successful endovascular reperfusion, iron concentration in infarct tissue, as measured by QSM increases over time compared to that in healthy tissue. However, its significance warrants further investigation.

Endovascular Thrombectomy for Large Ischemic Stroke Across Ischemic Injury and Penumbra Profiles.

Importance: Whether endovascular thrombectomy (EVT) efficacy for patients with acute ischemic stroke and large cores varies depending on the extent of ischemic injury is uncertain. Objective: To describe the relationship between imaging estimates of irreversibly injured brain (core) and at-risk regions (mismatch) and clinical outcomes and EVT treatment effect. Design, Setting, and Participants: An exploratory analysis of the SELECT2 trial, which randomized 352 adults (18-85 years) with acute ischemic stroke due to occlusion of the internal carotid or middle cerebral artery (M1 segment) and large ischemic core to EVT vs medical management (MM), across 31 global centers between October 2019 and September 2022. Intervention: EVT vs MM. Main Outcomes and Measures: Primary outcome was functional outcome-90-day mRS score (0, no symptoms, to 6, death) assessed by adjusted generalized OR (aGenOR; values >1 represent more favorable outcomes). Benefit of EVT vs MM was assessed across levels of ischemic injury defined by noncontrast CT using ASPECTS score and by the volume of brain with severely reduced blood flow on CT perfusion or restricted diffusion on MRI. Results: Among 352 patients randomized, 336 were analyzed (median age, 67 years; 139 [41.4%] female); of these, 168 (50%) were randomized to EVT, and 2 additional crossover MM patients received EVT. In an ordinal analysis of mRS at 90 days, EVT improved functional outcomes compared with MM within ASPECTS categories of 3 (aGenOR, 1.71 [95% CI, 1.04-2.81]), 4 (aGenOR, 2.01 [95% CI, 1.19-3.40]), and 5 (aGenOR, 1.85 [95% CI, 1.22-2.79]). Across strata for CT perfusion/MRI ischemic core volumes, aGenOR for EVT vs MM was 1.63 (95% CI, 1.23-2.16) for volumes ≥70 mL, 1.41 (95% CI, 0.99-2.02) for ≥100 mL, and 1.47 (95% CI, 0.84-2.56) for ≥150 mL. In the EVT group, outcomes worsened as ASPECTS decreased (aGenOR, 0.91 [95% CI, 0.82-1.00] per 1-point decrease) and as CT perfusion/MRI ischemic core volume increased (aGenOR, 0.92 [95% CI, 0.89-0.95] per 10-mL increase). No heterogeneity of EVT treatment effect was observed with or without mismatch, although few patients without mismatch were enrolled. Conclusion and Relevance: In this exploratory analysis of a randomized clinical trial of patients with extensive ischemic stroke, EVT improved clinical outcomes across a wide spectrum of infarct volumes, although enrollment of patients with minimal penumbra volume was low. In EVT-treated patients, clinical outcomes worsened as presenting ischemic injury estimates increased. Trial Registration: ClinicalTrials.gov Identifier: NCT03876457.

Role of cardiac computed tomography in hyperacute stroke assessment.

BACKGROUND: Incorporating cardiac CT with hyperacute stroke imaging may increase the yield for cardioembolic sources. It is not clarified whether stroke severity influences on rates of intracardiac thrombus. We aimed to investigate a National Institutes of Health Stroke Scale (NIHSS) threshold below which acute cardiac CT was unnecessary. METHODS: Consecutive patients with suspected stroke who underwent multimodal brain imaging and concurrent non-gated cardiac CT with delayed timing were prospectively recruited from 1st December 2020 to 30th November 2021. We performed receiver operating characteristics analysis of the NIHSS and intracardiac thrombus on hyperacute cardiac CT. RESULTS: A total of 314 patients were assessed (median age 69 years, 61% male). Final diagnoses were ischemic stroke (n=205; 132 etiology-confirmed stroke, independent of cardiac CT and 73 cryptogenic), transient ischemic attack (TIA) (n=21) and stroke-mimic syndromes (n=88). The total yield of cardiac CT was 8 intracardiac thrombus and 1 dissection. Cardiac CT identified an intracardiac thrombus in 6 (4.5%) with etiology-confirmed stroke, 2 (2.7%) with cryptogenic stroke, and none in patients with TIA or stroke-mimic. All of those with intracardiac thrombus had NIHSS ≥4 and this was the threshold below which hyperacute cardiac CT was not justified (sensitivity 100%, specificity 38%, positive predictive value 4.0%, negative predictive value 100%). CONCLUSIONS: A cutoff NIHSS ≥4 may be useful to stratify patients for cardiac CT in the hyperacute stroke setting to optimize its diagnostic yield and reduce additional radiation exposure.

Tenecteplase Treatment and Thrombus Characteristics Associated With Early Reperfusion: An EXTEND-IA TNK Trials Analysis.

BACKGROUND: Intracranial occlusion site, contrast permeability, and clot burden are thrombus characteristics that influence alteplase-associated reperfusion. In this study, we assessed the reperfusion efficacy of tenecteplase and alteplase in subgroups based on these characteristics in a pooled analysis of the EXTEND-IA TNK trial (Tenecteplase Versus Alteplase Before Endovascular Therapy for Ischemic Stroke). METHODS: Patients with large vessel occlusion were randomized to treatment with tenecteplase (0.25 or 0.4 mg/kg) or alteplase before thrombectomy in hospitals across Australia and New Zealand (2015-2019). The primary outcome, early reperfusion, was defined as the absence of retrievable thrombus or >50% reperfusion on first-pass angiogram. We compared the effect of tenecteplase versus alteplase overall, and in subgroups, based on the following measured with computed tomography angiography: intracranial occlusion site, contrast permeability (measured via residual flow grades), and clot burden (measured via clot burden scores). We adjusted for covariates using mixed effects logistic regression models. RESULTS: Tenecteplase was associated with higher odds of early reperfusion (75/369 [20%] versus alteplase: 9/96 [9%], adjusted odds ratio [aOR], 2.18 [95% CI, 1.03-4.63]). The difference between thrombolytics was notable in occlusions with low clot burden (tenecteplase: 66/261 [25%] versus alteplase: 5/67 [7%], aOR, 3.93 [95% CI, 1.50-10.33]) when compared to high clot burden lesions (tenecteplase: 9/108 [8%] versus alteplase: 4/29 [14%], aOR, 0.58 [95% CI, 0.16-2.06]; Pinteraction=0.01). We did not observe an association between contrast permeability and tenecteplase treatment effect (permeability present: aOR, 2.83 [95% CI, 1.00-8.05] versus absent: aOR, 1.98 [95% CI, 0.65-6.03]; Pinteraction=0.62). Tenecteplase treatment effect was superior with distal M1 or M2 occlusions (53/176 [30%] versus alteplase: 4/42 [10%], aOR, 3.73 [95% CI, 1.25-11.11]), but both thrombolytics had limited efficacy with internal carotid artery occlusions (tenecteplase 1/73 [1%] versus alteplase 1/19 [5%], aOR, 0.22 [95% CI, 0.01-3.83]; Pinteraction=0.16). CONCLUSIONS: Tenecteplase demonstrates superior early reperfusion versus alteplase in lesions with low clot burden. Reperfusion efficacy remains limited in internal carotid artery occlusions and lesions with high clot burden. Further innovation in thrombolytic therapies are required.

Management of Poststroke Hyperglycemia: Results of the TEXAIS Randomized Clinical Trial.

BACKGROUND: Hyperglycemia in acute ischemic stroke reduces the efficacy of stroke thrombolysis and thrombectomy, with worse clinical outcomes. Insulin-based therapies are difficult to implement and may cause hypoglycemia. We investigated whether exenatide, a GLP-1 (glucagon-like peptide-1) receptor agonist, would improve stroke outcomes, and control poststroke hyperglycemia with minimal hypoglycemia. METHODS: The TEXAIS trial (Treatment With Exenatide in Acute Ischemic Stroke) was an international, multicenter, phase 2 prospective randomized clinical trial (PROBE [Prospective Randomized Open Blinded End-Point] design) enrolling adult patients with acute ischemic stroke ≤9 hours of stroke onset to receive exenatide (5 µg BID subcutaneous injection) or standard care for 5 days, or until hospital discharge (whichever sooner). The primary outcome (intention to treat) was the proportion of patients with ≥8-point improvement in National Institutes of Health Stroke Scale score (or National Institutes of Health Stroke Scale scores 0-1) at 7 days poststroke. Safety outcomes included death, episodes of hyperglycemia, hypoglycemia, and adverse event. RESULTS: From April 2016 to June 2021, 350 patients were randomized (exenatide, n=177, standard care, n=173). Median age, 71 years (interquartile range, 62-79), median National Institutes of Health Stroke Scale score, 4 (interquartile range, 2-8). Planned recruitment (n=528) was stopped early due to COVID-19 disruptions and funding constraints. The primary outcome was achieved in 97 of 171 (56.7%) in the standard care group versus 104 of 170 (61.2%) in the exenatide group (adjusted odds ratio, 1.22 [95% CI, 0.79-1.88]; P=0.38). No differences in secondary outcomes were observed. The per-patient mean daily frequency of hyperglycemia was significantly less in the exenatide group across all quartiles. No episodes of hypoglycemia were recorded over the treatment period. Adverse events of mild nausea and vomiting occurred in 6 (3.5%) exenatide patients versus 0 (0%) standard care with no withdrawal. CONCLUSIONS: Treatment with exenatide did not reduce neurological impairment at 7 days in patients with acute ischemic stroke. Exenatide did significantly reduce the frequency of hyperglycemic events, without hypoglycemia, and was safe to use. Larger acute stroke trials using GLP-1 agonists such as exenatide should be considered. REGISTRATION: URL: www.australianclinicaltrials.gov.au; Unique identifier: ACTRN12617000409370. URL: https://www.clinicaltrials.gov; Unique identifier: NCT03287076.

Ultra-Long Transfers for Endovascular Thrombectomy-Mission Impossible?: The Australia-New Zealand Experience.

BACKGROUND: Endovascular thrombectomy (EVT) access in remote areas is limited. Preliminary data suggest that long distance transfers for EVT may be beneficial; however, the magnitude and best imaging strategy at the referring center remains uncertain. We hypothesized that patients transferred >300 miles would benefit from EVT, achieving rates of functional independence (modified Rankin Scale [mRS] score of 0-2) at 3 months similar to those patients treated at the comprehensive stroke center in the randomized EVT extended window trials and that the selection of patients with computed tomography perfusion (CTP) at the referring site would be associated with ordinal shift toward better outcomes on the mRS. METHODS: This is a retrospective analysis of patients transferred from 31 referring hospitals >300 miles (measured by the most direct road distance) to 9 comprehensive stroke centers in Australia and New Zealand for EVT consideration (April 2016 through May 2021). RESULTS: There were 131 patients; the median age was 64 [53-74] years and the median baseline National Institutes of Health Stroke Scale score was 16 [12-22]. At baseline, 79 patients (60.3%) had noncontrast CT+CT angiography, 52 (39.7%) also had CTP. At the comprehensive stroke center, 114 (87%) patients underwent cerebral angiography, and 96 (73.3%) proceeded to EVT. At 3 months, 62 patients (48.4%) had an mRS score of 0 to 2 and 81 (63.3%) mRS score of 0 to 3. CTP selection at the referring site was not associated with better ordinal scores on the mRS at 3 months (mRS median of 2 [1-3] versus 3 [1-6] in the patients selected with noncontrast CT+CT angiography, P=0.1). Nevertheless, patients selected with CTP were less likely to have an mRS score of 5 to 6 (odds ratio 0.03 [0.01-0.19]; P<0.01). CONCLUSIONS: In selected patients transferred >300 miles, there was a benefit for EVT, with outcomes similar to those treated in the comprehensive stroke center in the EVT extended window trials. Remote hospital CTP selection was not associated with ordinal mRS improvement, but was associated with fewer very poor 3-month outcomes.

Benchmark dataset for clot detection in ischemic stroke vessel-based imaging: CODEC-IV.

We present an annotated dataset for the purposes of creating a benchmark in Artificial Intelligence for automated clot detection. While there are commercial tools available for automated clot detection on computed tomographic (CT) angiographs, they have not been compared in a standardized manner whereby accuracy is reported on a publicly available benchmark dataset. Furthermore, there are known difficulties in automated clot detection - namely, cases where there is robust collateral flow, or residual flow and occlusions of the smaller vessels - and it is necessary to drive an initiative to overcome these challenges. Our dataset contains 159 multiphase CTA patient datasets, derived from CTP and annotated by expert stroke neurologists. In addition to images where the clot is marked, the expert neurologists have provided information about clot location, hemisphere and the degree of collateral flow. The data is available on request by researchers via an online form, and we will host a leaderboard where the results of clot detection algorithms on the dataset will be displayed. Participants are invited to submit an algorithm to us for evaluation using the evaluation tool, which is made available at together with the form at https://github.com/MBC-Neuroimaging/ClotDetectEval.

Endovascular thrombectomy versus standard bridging thrombolytic with endovascular thrombectomy within 4·5 h of stroke onset: an open-label, blinded-endpoint, randomised non-inferiority trial.

BACKGROUND: The benefit of combined treatment with intravenous thrombolysis before endovascular thrombectomy in patients with acute ischaemic stroke caused by large vessel occlusion remains unclear. We hypothesised that the clinical outcomes of patients with stroke with large vessel occlusion treated with direct endovascular thrombectomy within 4·5 h would be non-inferior compared with the outcomes of those treated with standard bridging therapy (intravenous thrombolysis before endovascular thrombectomy). METHODS: DIRECT-SAFE was an international, multicentre, prospective, randomised, open-label, blinded-endpoint trial. Adult patients with stroke and large vessel occlusion in the intracranial internal carotid artery, middle cerebral artery (M1 or M2), or basilar artery, confirmed by non-contrast CT and vascular imaging, and who presented within 4·5 h of stroke onset were recruited from 25 acute-care hospitals in Australia, New Zealand, China, and Vietnam. Eligible patients were randomly assigned (1:1) via a web-based, computer-generated randomisation procedure stratified by site of baseline arterial occlusion and by geographic region to direct endovascular thrombectomy or bridging therapy. Patients assigned to bridging therapy received intravenous thrombolytic (alteplase or tenecteplase) as per standard care at each site; endovascular thrombectomy was also per standard of care, using the Trevo device (Stryker Neurovascular, Fremont, CA, USA) as first-line intervention. Personnel assessing outcomes were masked to group allocation; patients and treating physicians were not. The primary efficacy endpoint was functional independence defined as modified Rankin Scale score 0-2 or return to baseline at 90 days, with a non-inferiority margin of -0·1, analysed by intention to treat (including all randomly assigned and consenting patients) and per protocol. The intention-to-treat population was included in the safety analyses. The trial is registered with ClinicalTrials.gov, NCT03494920, and is closed to new participants. FINDINGS: Between June 2, 2018, and July 8, 2021, 295 patients were randomly assigned to direct endovascular thrombectomy (n=148) or bridging therapy (n=147). Functional independence occurred in 80 (55%) of 146 patients in the direct thrombectomy group and 89 (61%) of 147 patients in the bridging therapy group (intention-to-treat risk difference -0·051, two-sided 95% CI -0·160 to 0·059; per-protocol risk difference -0·062, two-sided 95% CI -0·173 to 0·049). Safety outcomes were similar between groups, with symptomatic intracerebral haemorrhage occurring in two (1%) of 146 patients in the direct group and one (1%) of 147 patients in the bridging group (adjusted odds ratio 1·70, 95% CI 0·22-13·04) and death in 22 (15%) of 146 patients in the direct group and 24 (16%) of 147 patients in the bridging group (adjusted odds ratio 0·92, 95% CI 0·46-1·84). INTERPRETATION: We did not show non-inferiority of direct endovascular thrombectomy compared with bridging therapy. The additional information from our study should inform guidelines to recommend bridging therapy as standard treatment. FUNDING: Australian National Health and Medical Research Council and Stryker USA.

Thrombectomy versus Medical Management in Mild Strokes due to Large Vessel Occlusion: Exploratory Analysis from the EXTEND-IA Trials and a Pooled International Cohort.

OBJECTIVE: This study was undertaken to evaluate functional and safety outcomes for endovascular thrombectomy (EVT) versus medical management (MM) in patients with large vessel occlusion (LVO) and mild neurological deficits, stratified by perfusion imaging mismatch. METHODS: The pooled cohort consisted of patients with National Institutes of Health Stroke Scale (NIHSS) < 6 and internal carotid artery (ICA), M1, or M2 occlusions from the Extending the Time for Thrombolysis in Emergecy Neurological Deficits - Intra-Arterial (EXTEND-IA) Trial,  Tenecteplase vs Alteplase before Endovascular Thrombectomy in Ischemic Stroke (EXTEND-IA TNK) trials Part I/II and prospective data from 15 EVT centers from October 2010 to April 2020. RAPID software estimated ischemic core and mismatch. Patients receiving primary EVT (EVTpri ) were compared to those who received primary MM (MMpri ), including those who deteriorated and received rescue EVT, in overall and propensity score (PS)-matched cohorts. Patients were stratified by target mismatch (mismatch ratio ≥ 1.8 and mismatch volume ≥ 15ml). Primary outcome was functional independence (90-day modified Rankin Scale = 0-2). Secondary outcomes included safety (symptomatic intracerebral hemorrhage [sICH], neurological worsening, and mortality). RESULTS: Of 540 patients, 286 (53%) received EVTpri and demonstrated larger critically hypoperfused tissue (Tmax > 6 seconds) volumes (median [IQR]: 64 [26-96] ml vs MMpri : 40 [14-76] ml, p < 0.001) and higher presentation NIHSS (median [IQR]: 4 [2-5] vs MMpri : 3 [2-4], p < 0.001). Functional independence was similar (EVTpri : 77.4% vs MMpri : 75.6%, adjusted odds ratio [aOR] = 1.29, 95% confidence interval [CI] = 0.82-2.03, p = 0.27). EVT had worse safety regarding sICH (EVTpri : 16.3% vs MMpri : 1.3%, p < 0.001) and neurological worsening (EVTpri : 19.6% vs MMpri : 6.7%, p < 0.001). In 414 subjects (76.7%) with target mismatch, EVT was associated with improved functional independence (EVTpri : 77.4% vs MMpri : 72.7%, aOR = 1.68, 95% CI = 1.01-2.81, p = 0.048), whereas there was a trend toward less favorable outcomes with primary EVT (EVTpri : 77.4% vs MMpri : 83.3%, aOR = 0.39, 95% CI = 0.12-1.34, p = 0.13) without target mismatch (pinteraction  = 0.06). Similar findings were observed in a propensity score-matched subpopulation. INTERPRETATION: Overall, EVT was not associated with improved clinical outcomes in mild strokes due to LVO, and sICH was increased. However, in patients with target mismatch profile, EVT was associated with increased functional independence. Perfusion imaging may be helpful to select mild stroke patients for EVT. ANN NEUROL 2022;92:364-378.

CT vascular territory mapping: a novel method to identify large vessel occlusion collateral.

INTRODUCTION: This descriptive study explores typical patterns of vascular territory mapping (VTM) in ischaemic stroke patients with proximal vessel occlusion. VTM is a novel process using CT perfusion that can identify the source and extent of collateral blood flow in patients with vessel occlusion. It functions by determining which vessel provides dominant blood flow to a brain voxel. METHODS: A total of 167 consecutive patients were analysed from INSPIRE (International Stroke Perfusion Imaging Registry) with their CT perfusion reprocessed through VTM software. We explored the typical territory maps generated by this software relating to common large vessel occlusion location sites (ACA/MCA/PCA). RESULTS/CONCLUSION: In the presence of occlusion, VTM demonstrated a reciprocal increase in collateral vessel territories.

Diagnostic Utility of Computed Tomography Perfusion in the Telestroke Setting.

BACKGROUND: Definitive diagnosis of acute ischemic stroke is challenging, particularly in telestroke settings. Although the prognostic utility of CT perfusion (CTP) has been questioned, its diagnostic value remains under-appreciated, especially in cases without an easily visible intracranial occlusion. We assessed the diagnostic accuracy of routine CTP in the acute telestroke setting. METHODS: Acute and follow-up data collected prospectively from consecutive suspected patients with stroke assessed by a state-wide telestroke service between March 2020 and August 2021 at 12 sites in Australia were analyzed. All patients in the final analysis had been assessed with multimodal CT, including CTP, which was post-processed with automated volumetric software. Diagnostic sensitivity and specificity were calculated for multimodal CT and each individual component (noncontrast CT [NCCT], CT angiogram [CTA], and CTP). Final diagnosis determined by consensus review of follow-up imaging and clinical data was used as the reference standard. RESULTS: During the study period, complete multimodal CT examination was obtained in 831 patients, 457 of whom were diagnosed with stroke. Diagnostic sensitivity for ischemic stroke increased by 19.5 percentage points when CTP was included with NCCT and CTA compared with NCCT and CTA alone (73.1% positive with NCCT+CTA+CTP [95% CI, 68.8-77.1] versus 53.6% positive with NCCT+CTA alone [95% CI, 48.9-58.3], P<0.001). No difference was observed between specificities of NCCT+CTA and NCCT+CTA+CTP (98.7% [95% CI, 98.5-100] versus 98.7% [95% CI, 96.9-99.6], P=0.13). Multimodal CT, including CTP, demonstrated the highest negative predictive value (75.0% [95% CI, 72.1-77.7]). Patients with stroke not evident on CTP had small volume infarcts on follow-up (1.2 mL, interquartile range 0.5-2.7mL). CONCLUSIONS: Acquisition of CTP as part of a telestroke imaging protocol permits definitive diagnosis of cerebral ischemia in 1 in 5 patients with normal NCCT and CTA.

Microvascular Dysfunction in Blood-Brain Barrier Disruption and Hypoperfusion Within the Infarct Posttreatment Are Associated With Cerebral Edema.

BACKGROUND: Factors contributing to cerebral edema in the post-hyperacute period of ischemic stroke (first 24-72 hours) are poorly understood. Blood-brain barrier (BBB) disruption and postischemic hyperperfusion reflect microvascular dysfunction and are associated with hemorrhagic transformation. We investigated the relationships between BBB integrity, cerebral blood flow, and space-occupying cerebral edema in patients who received acute reperfusion therapy. METHODS: We performed a pooled analysis of patients treated for anterior circulation large vessel occlusion in the EXTEND-IA TNK and EXTEND-IA TNK part 2 trials who had MRI with dynamic susceptibility contrast-enhanced perfusion-weighted imaging 24 hours after treatment. We investigated the associations between BBB disruption and cerebral blood flow within the infarct with cerebral edema assessed using 2 metrics: first midline shift (MLS) trichotomized as an ordinal scale of negligible (<1 mm), mild (≥1 to <5 mm), or severe (≥5 mm), and second relative hemispheric volume (rHV), defined as the ratio of the 3-dimensional volume of the ischemic hemisphere relative to the contralateral hemisphere. RESULTS: Of 238 patients analyzed, 133 (55.9%) had negligible, 93 (39.1%) mild, and 12 (5.0%) severe MLS at 24 hours. The associated median rHV was 1.01 (IQR, 1.00-1.028), 1.03 (IQR, 1.01-1.077), and 1.15 (IQR, 1.08-1.22), respectively. MLS and rHV were associated with poor functional outcome at 90 days (P<0.002). Increased BBB permeability was independently associated with more edema after adjusting for age, occlusion location, reperfusion, parenchymal hematoma, and thrombolytic agent used (MLS cOR, 1.12 [95% CI, 1.03-1.20], P=0.005; rHV ß, 0.39 [95% CI, 0.24-0.55], P<0.0001), as was reduced cerebral blood flow (MLS cOR, 0.25 [95% CI, 0.10-0.58], P=0.001; rHV ß, -2.95 [95% CI, -4.61 to -11.29], P=0.0006). In subgroup analysis of patients with successful reperfusion (extended Treatment in Cerebral Ischemia 2b-3, n=200), reduced cerebral blood flow remained significantly associated with edema (MLS cOR, 0.37 [95% CI, 0.14-0.98], P=0.045; rHV ß, -2.59 [95% CI, -4.32 to -0.86], P=0.004). CONCLUSIONS: BBB disruption and persistent hypoperfusion in the infarct after reperfusion treatment is associated with space-occupying cerebral edema. Further studies evaluating microvascular dysfunction during the post-hyperacute period as biomarkers of poststroke edema and potential therapeutic targets are warranted.

Reduced Severity of Tissue Injury Within the Infarct May Partially Mediate the Benefit of Reperfusion in Ischemic Stroke.

BACKGROUND: Emerging data suggest tissue within the infarct lesion is not homogenously damaged following ischemic stroke but has a gradient of injury. Using blood-brain-barrier (BBB) disruption as a marker of tissue injury, we tested whether therapeutic reperfusion improves clinical outcome by reducing the severity of tissue injury within the infarct in patients with ischemic stroke. METHODS: In a pooled analysis of patients treated for anterior circulation large vessel occlusion in the EXTEND-IA TNK (Tenecteplase Versus Alteplase Before Endovascular Therapy for Ischemic Stroke) and EXTEND-IA part-2 (Determining the Optimal Dose of Tenecteplase Before Endovascular Therapy for Ischaemic Stroke) trials, post-treatment BBB permeability at 24 hours was calculated based on the extent of T1-brightening by extravascular gadolinium on T2* perfusion-weighted imaging and measured within the diffusion-weighted-imaging lesion. First, to determine the clinical significance of BBB disruption as a marker of severity of tissue injury, we examined the association between post-treatment BBB permeability and functional outcome. Second, we performed an exploratory (reperfusion, BBB permeability, functional outcome) mediation analysis to estimate the proportion of the reperfusion-outcome relationship that is mediated by change in BBB permeability. RESULTS: In the 238 patients analyzed, an increased BBB permeability measured within the infarct at 24 hours was associated with a reduced likelihood of favorable outcome (90-day modified Rankin Scale score of ≤2) after adjusting for age, baseline National Institutes of Health Stroke Scale, premorbid modified Rankin Scale, infarct topography, laterality, thrombolytic agent, sex, parenchymal hematoma, and follow-up infarct volume (adjusted odds ratio, 0.86 [95% CI, 0.75-0.98]; P=0.023). Mediation analysis suggested reducing the severity of tissue injury (as estimated by BBB permeability) accounts for 18.2% of the association between reperfusion and favorable outcome, as indicated by a reduction in the regression coefficient of reperfusion after addition of BBB permeability as a covariate. CONCLUSIONS: In patients with ischemic stroke, reduced severity of tissue injury within the infarct, as determined by assessing the integrity of the BBB, is independently associated with improved functional outcome. In addition to reducing diffusion-weighted imaging-defined infarct volume, reperfusion may also improve clinical outcome by reducing tissue injury severity within the infarct.