Neurological Improvement by One-Thirds Is Associated With Early Recanalization in Stroke With Large Vessel Occlusion.

BACKGROUND: A proportion of large vessel occlusion strokes demonstrate early recanalization, obviating the initial intention to proceed to endovascular thrombectomy. Neurological improvement is a possible surrogate marker for reperfusion. We aimed to determine the optimal threshold of neurological improvement, as defined by the National Institutes of Health Stroke Scale (NIHSS), which best associates with early recanalization. METHODS: We retrospectively analyzed consecutive patients with large vessel occlusion transferred from primary stroke centers to a tertiary comprehensive stroke center in Melbourne, Australia, for possible endovascular thrombectomy from January 2018 to December 2022. Absolute and percentage changes in NIHSS between transfer, as well as other definitions of neurological improvement, were compared using receiver operating characteristic curve analysis for association with recanalization as defined by the absence of occlusion in the internal carotid artery, middle cerebral artery (M1 or M2 segments), or basilar artery on repeat vascular imaging. RESULTS: Six hundred and fifty-four transferred patients with large vessel occlusion were included in the analysis: mean age was 68.8±14.0 years, 301 (46.0%) were women, and 338 (52%) received intravenous thrombolytics. The proportion of extracranial internal carotid artery, intracranial internal carotid artery, M1, proximal M2, and basilar artery occlusion was 18.8%, 13.6%, 48.3%, 15.0%, and 4.3%, respectively, on initial computed tomography angiogram. Median NIHSSprimary stroke center and NIHSScomprehensive stroke center scores were 15 (interquartile range, 9-18) and 13 (interquartile range, 8-19), respectively. Early recanalization occurred in 82 (13%) patients. NIHSS reduction of ≥33% was the best tradeoff between sensitivity (64%) and specificity (83%) for identifying recanalization. NIHSS reduction of ≥33% had the highest discriminative ability to predict recanalization (area under the curve, 0.735) in comparison with other definitions of neurological improvement. CONCLUSIONS: One-third neurological improvement between the primary hospital and tertiary center was the best predictor of early recanalization.

Atrial fibrillation is associated with higher first pass effect following thrombectomy for large vessel occlusion.

BACKGROUND: First pass effect (FPE), defined as single-pass complete or near complete reperfusion during endovascular thrombectomy (EVT) for large vessel occlusion (LVO) strokes, is a critical performance metric. Atrial fibrillation (AF)-related strokes have different clot composition compared with non-AF strokes, which may impact thrombectomy reperfusion results. We compared FPE rates in AF and non-AF stroke patients to evaluate if AF-related strokes had higher FPE rates. METHODS: We conducted a post-hoc analysis of the DIRECT-SAFE trial data, including patients with retrievable clots on the initial angiographic run. Patients were categorized into AF and non-AF groups. The primary outcome was the presence or absence of FPE (single-pass, single-device resulting in complete/near complete reperfusion) in AF and non-AF groups. We used multivariable logistic regression to examine the association between FPE and AF, adjusting for thrombolysis pre-thrombectomy and clot location. RESULTS: We included 253 patients (67 with AF, 186 without AF). AF patients were older (mean age: 74 years vs 67.5 years, p=0.001), had a higher proportion of females (55% vs 40%, p=0.044), and experienced more severe strokes (median National Institutes of Health Stroke Scale (NIHSS) score: 17 vs 14, p=0.009) than non-AF patients. No differences were observed in thrombolytic agent usage, time metrics, or clot location. AF patients achieved a higher proportion of FPE compared with non-AF patients (55.22% vs 37.3%, adjusted odds ratio 2.00 (95% CI 1.13 to 3.55), p=0.017). CONCLUSIONS: AF-related strokes in LVO patients treated with EVT were associated with FPE. This highlights the need for preparedness for multiple passes and potential adjuvant/rescue therapy in non-AF-related strokes.

Value of intravenous thrombolysis in endovascular treatment for large-vessel anterior circulation stroke: individual participant data meta-analysis of six randomised trials.

BACKGROUND: Intravenous thrombolysis is recommended before endovascular treatment, but its value has been questioned in patients who are admitted directly to centres capable of endovascular treatment. Existing randomised controlled trials have indicated non-inferiority of endovascular treatment alone or have been statistically inconclusive. We formed the Improving Reperfusion Strategies in Acute Ischaemic Stroke collaboration to assess non-inferiority of endovascular treatment alone versus intravenous thrombolysis plus endovascular treatment. METHODS: We conducted a systematic review and individual participant data meta-analysis to establish non-inferiority of endovascular treatment alone versus intravenous thrombolysis plus endovascular treatment. We searched PubMed and MEDLINE with the terms "stroke", "endovascular treatment", "intravenous thrombolysis", and synonyms for articles published from database inception to March 9, 2023. We included randomised controlled trials on the topic of interest, without language restrictions. Authors of the identified trials agreed to take part, and individual participant data were provided by the principal investigators of the respective trials and collated centrally by the collaborators. Our primary outcome was the 90-day modified Rankin Scale (mRS) score. Non-inferiority of endovascular treatment alone was assessed using a lower boundary of 0·82 for the 95% CI around the adjusted common odds ratio (acOR) for shift towards improved outcome (analogous to 5% absolute difference in functional independence) with ordinal regression. We used mixed-effects models for all analyses. This study is registered with PROSPERO, CRD42023411986. FINDINGS: We identified 1081 studies, and six studies (n=2313; 1153 participants randomly assigned to receive endovascular treatment alone and 1160 randomly assigned to receive intravenous thrombolysis and endovascular treatment) were eligible for analysis. The risk of bias of the included studies was low to moderate. Variability between studies was small, and mainly related to the choice and dose of the thrombolytic drug and country of execution. The median mRS score at 90 days was 3 (IQR 1-5) for participants who received endovascular treatment alone and 2 (1-4) for participants who received intravenous thrombolysis plus endovascular treatment (acOR 0·89, 95% CI 0·76-1·04). Any intracranial haemorrhage (0·82, 0·68-0·99) occurred less frequently with endovascular treatment alone than with intravenous thrombolysis plus endovascular treatment. Symptomatic intracranial haemorrhage and mortality rates did not differ significantly. INTERPRETATION: We did not establish non-inferiority of endovascular treatment alone compared with intravenous thrombolysis plus endovascular treatment in patients presenting directly at endovascular treatment centres. Further research could focus on cost-effectiveness analysis and on individualised decisions when patient characteristics, medication shortages, or delays are expected to offset a potential benefit of administering intravenous thrombolysis before endovascular treatment. FUNDING: Stryker and Amsterdam University Medical Centers, University of Amsterdam.

Occult contrast retention post-thrombectomy on 24-h follow-up dual-energy CT: Associations and impact on imaging analysis.

BACKGROUND: Following reperfusion treatment in ischemic stroke, computed tomography (CT) imaging at 24 h is widely used to assess radiological outcomes. Even without visible hyperattenuation, occult angiographic contrast may persist in the brain and confound Hounsfield unit-based imaging metrics, such as net water uptake (NWU). AIMS: We aimed to assess the presence and factors associated with retained contrast post-thrombectomy on 24-h imaging using dual-energy CT (DECT), and its impact on the accuracy of NWU as a measure of cerebral edema. METHODS: Consecutive patients with anterior circulation large vessel occlusion who had post-thrombectomy DECT performed 24-h post-treatment from two thrombectomy stroke centers were retrospectively studied. NWU was calculated by interside comparison of HUs of the infarct lesion and its mirror homolog. Retained contrast was quantified by the difference in NWU values with and without adjustment for iodine. Patients with visible hyperdensities from hemorrhagic transformation or visible contrast retention and bilateral infarcts were excluded. Cerebral edema was measured by relative hemispheric volume (rHV) and midline shift (MLS). RESULTS: Of 125 patients analyzed (median age 71 (IQR = 61-80), baseline National Institutes of Health Stroke Scale (NIHSS) 16 (IQR = 9.75-21)), reperfusion (defined as extended-Thrombolysis-In-Cerebral-Infarction 2b-3) was achieved in 113 patients (90.4%). Iodine-subtracted NWU was significantly higher than unadjusted NWU (17.1% vs 10.8%, p < 0.001). In multivariable median regression analysis, increased age (p = 0.024), number of passes (p = 0.006), final infarct volume (p = 0.023), and study site (p = 0.021) were independently associated with amount of retained contrast. Iodine-subtracted NWU correlated with rHV (rho = 0.154, p = 0.043) and MLS (rho = 0.165, p = 0.033) but unadjusted NWU did not (rHV rho = -0.035, p = 0.35; MLS rho = 0.035, p = 0.347). CONCLUSIONS: Angiographic iodine contrast is retained in brain parenchyma 24-h post-thrombectomy, even without visually obvious hyperdensities on CT, and significantly affects NWU measurements. Adjustment for retained iodine using DECT is required for accurate NWU measurements post-thrombectomy. Future quantitative studies analyzing CT after thrombectomy should consider occult contrast retention.

Functional recovery continues beyond 3 months post-basilar artery thrombectomy: A retrospective cohort study.

INTRODUCTION: Untreated basilar artery occlusion (BAO) carries 70% mortality. Guidelines recommend thrombectomy with or without thrombolysis. AIM: We compared Modified Rankin Scores (mRS) at 3 and 12 months post thrombectomy to determine benefit of long-term follow up. METHODS: Retrospective, single centre analysis of BAO thrombectomies between 2015 and 2019. Inclusion criteria were symptomatic BAO on CT angiography, absent early ischemic changes, premorbid independence and intervention within 24 h. All received stroke ward care. Results were analysed with simple statistics and binary logistic regression as appropriate. RESULTS: Of 82 patients: most were male (61%, 50/82) with median age 68 years (IQR 17 years) and median NIHSS 14 (IQR 15). Median door-to-puncture time was 42 min (IQR 72 min). Total deaths were 34.1% (28/82) at 3 months, and 37.8% (31/82) at 12 months. Of 51 patients alive at 12 months: 41% (21/51) had improved mRS, 16% (8/51) had worse mRS and 43% (22/51) had unchanged mRS, compared to 3 months. Improvements to mRS were: one point in 57.1% (14/21), two points in 28.9% (6/21) and three points in 4.8% (1/21). Nursing home admission was avoided in 11.8% (6/51) who improved from mRS4. Increased age was associated with decreased likelihood of reaching the primary outcome OR 0.87, 95% CI 0.76-0.99 (p value = 0.03). CONCLUSION: Over a quarter of patients improved beyond 3 months. Future studies should adopt long-term follow up as primary outcome.

Assessment of Safety of a Fully Implanted Endovascular Brain-Computer Interface for Severe Paralysis in 4 Patients: The Stentrode With Thought-Controlled Digital Switch (SWITCH) Study.

Importance: Brain-computer interface (BCI) implants have previously required craniotomy to deliver penetrating or surface electrodes to the brain. Whether a minimally invasive endovascular technique to deliver recording electrodes through the jugular vein to superior sagittal sinus is safe and feasible is unknown. Objective: To assess the safety of an endovascular BCI and feasibility of using the system to control a computer by thought. Design, Setting, and Participants: The Stentrode With Thought-Controlled Digital Switch (SWITCH) study, a single-center, prospective, first in-human study, evaluated 5 patients with severe bilateral upper-limb paralysis, with a follow-up of 12 months. From a referred sample, 4 patients with amyotrophic lateral sclerosis and 1 with primary lateral sclerosis met inclusion criteria and were enrolled in the study. Surgical procedures and follow-up visits were performed at the Royal Melbourne Hospital, Parkville, Australia. Training sessions were performed at patients' homes and at a university clinic. The study start date was May 27, 2019, and final follow-up was completed January 9, 2022. Interventions: Recording devices were delivered via catheter and connected to subcutaneous electronic units. Devices communicated wirelessly to an external device for personal computer control. Main Outcomes and Measures: The primary safety end point was device-related serious adverse events resulting in death or permanent increased disability. Secondary end points were blood vessel occlusion and device migration. Exploratory end points were signal fidelity and stability over 12 months, number of distinct commands created by neuronal activity, and use of system for digital device control. Results: Of 4 patients included in analyses, all were male, and the mean (SD) age was 61 (17) years. Patients with preserved motor cortex activity and suitable venous anatomy were implanted. Each completed 12-month follow-up with no serious adverse events and no vessel occlusion or device migration. Mean (SD) signal bandwidth was 233 (16) Hz and was stable throughout study in all 4 patients (SD range across all sessions, 7-32 Hz). At least 5 attempted movement types were decoded offline, and each patient successfully controlled a computer with the BCI. Conclusions and Relevance: Endovascular access to the sensorimotor cortex is an alternative to placing BCI electrodes in or on the dura by open-brain surgery. These final safety and feasibility data from the first in-human SWITCH study indicate that it is possible to record neural signals from a blood vessel. The favorable safety profile could promote wider and more rapid translation of BCI to people with paralysis. Trial Registration: ClinicalTrials.gov Identifier: NCT03834857.

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.

Comparison of Computed Tomography Perfusion and Multiphase Computed Tomography Angiogram in Predicting Clinical Outcomes in Endovascular Thrombectomy.

BACKGROUND: In patients with acute stroke who undergo endovascular thrombectomy, the relative prognostic power of computed tomography perfusion (CTP) parameters compared with multiphase CT angiogram (mCTA) is unknown. We aimed to compare the predictive accuracy of mCTA and CTP parameters on clinical outcomes. METHODS: We included patients with acute ischemic stroke who had anterior circulation large vessel occlusion within 24 hours of onset in Melbourne Brain Centre at the Royal Melbourne Hospital. All patients underwent CTP for endovascular thrombectomy, and the mCTA collateral score was determined using CTP-reconstructed mCTA images. The primary outcome was 90-day functional outcomes defined by modified Rankin Scale. Multivariable logistic regression models analyzed associations between mCTA and CTP parameters and 90-day functional outcomes. The ability to discriminate 90 days-functional outcomes was compared between mCTA collateral score and CTP parameters using receiver operating curve analysis and C statistics. RESULTS: One hundred and twenty patients were included. The median age was 69 years (interquartile range, 60-79), the median baseline National Institutes of Health Stroke Scale score was 14 (interquartile range, 9-19). The baseline ischemic core volume, defined by CTP-based relative cerebral blood flow <30%, was associated with excellent functional outcome (modified Rankin Scale score 0-1; odds ratio, 0.942 [-0.897 to -0.989]; P=0.015) and poor functional outcome (modified Rankin Scale score 5-6; odds ratio, 1.032 [1.007-1.056]; P=0.010) at 90 days in the analysis of multivariable regression. There was no significant association between the mCTA score and excellent functional outcome (P=0.58) or poor functional outcome (P=0.155). The relative cerebral blood flow <30%-based regression model best fit the data for the 90-day poor functional outcome (C statistic, 0.834). CONCLUSIONS: The CTP-based ischemic core volume may provide better discrimination for 90-day functional outcomes for patients with acute stroke undergoing endovascular thrombectomy than the mCTA collateral score.

DIRECT-SAFE: A Randomized Controlled Trial of DIRECT Endovascular Clot Retrieval versus Standard Bridging Therapy.

BACKGROUND AND PURPOSE: The benefit regarding co-treatment with intravenous (IV) thrombolysis before mechanical thrombectomy in acute ischemic stroke with large vessel occlusion remains unclear. To test the hypothesis that clinical outcome of ischemic stroke patients with intracranial internal carotid artery, middle cerebral artery or basilar artery occlusion treated with direct endovascular thrombectomy within 4.5 hours will be non-inferior compared with that of standard bridging IV thrombolysis followed by endovascular thrombectomy. METHODS: To randomize 780 patients 1:1 to direct thrombectomy or bridging IV thrombolysis with thrombectomy. An international-multicenter prospective randomized open label blinded endpoint trial (PROBE) (ClincalTrials.gov identifier: NCT03494920). RESULTS: Primary endpoint is functional independence defined as modified Rankin Scale (mRS) 0-2 or return to baseline at 90 days. Secondary end points include ordinal mRS analysis, good angiographic reperfusion (modified Thrombolysis in Cerebral Infarction score [mTICI] 2b-3), safety endpoints include symptomatic intracerebral hemorrhage and death. CONCLUSION: s DIRECT-SAFE will provide unique information regarding the impact of direct thrombectomy in patients with large vessel occlusion, including patients with basilar artery occlusion, with comparison across different ethnic groups.

Optimal Tissue Reperfusion Estimation by Computed Tomography Perfusion Post-Thrombectomy in Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Modified Thrombolysis in Cerebral Infarction score (mTICI) ≥2b is defined as successful reperfusion. However, mTICI has rarely been correlated with dynamic perfusion imaging postendovascular therapy for acute stroke. We aimed to study the proportion of tissue optimal reperfusion (TOR) postendovascular therapy across different grades of mTICI. METHODS: We conducted a single-center retrospective analysis of patients with acute ischemic strokes who had endovascular therapy between 2018 and 2019. Computer tomography perfusion or magnetic resonance perfusion was performed before and after endovascular therapy. Tmax+6 volume reduction of >90% was defined as TOR. Comparisons of proportions of TOR in different grades of mTICI were performed. In the present study, the requirement for informed consents was waived. RESULTS: Eighty-two patients were included. The difference in the proportion of TOR for TICI categories was statistically significant (mTICI score 0, 0%, mTICI score 2A, 0%, mTICI score 2b, 50.0%, mTICI score 2c, 80.0%, mTICI score 3, 81.3%, χ2=14.035, P=0.003). Multivariable logistic regression showed that lower age (odds ratio, 0.932, P=0.017), onset-to-tissue-type plasminogen activator time (odds ratio, 0.980, P=0.005) and TOR (odds ratio, 8.764, P=0.031) were associated with favorable functional outcome. CONCLUSIONS: The proportion of TOR achieved by mTICI score of 2b was significantly lower than mTICI score of 2c and mTICI score of 3. TOR was associated with favorable functional outcome, and the degree of reperfusion was more strongly correlated with outcomes than the mTICI scores.

Intrinsic hospital factors: overlooked cause for variations in delay to transfer for endovascular thrombectomy.

BACKGROUND: Intrinsic hospital factors leading to time delay to inter-hospital transfer for endovascular thrombectomy (EVT) have not been adequately investigated, leading to uncertainty in generalizability of hub and spoke EVT services. We investigated the contribution of intrinsic hospital factors to variations in time delay in a multicenter, retrospective study. METHODS: The setting was a hub and spoke EVT state-wide system for a population of 6.3 million and 34 spoke hospitals. We collected data on acute large vessel occlusion strokes transferred from spoke to hub for consideration of EVT between January 2016 and December 2018. The primary endpoint was the proportion of variability in delay-time in transfer cases contributed to by intrinsic hospital factors estimated through variance component analysis implemented as a mixed-effect linear regression model with hospitals as random effects. RESULTS: We included 434 patients. The median age was 72 years (IQR 62-79), 44% were female, and the median baseline National Institutes of Health Stroke Scale (NIHSS) was 16 (IQR 11-20). The median onset to CT time was 100 mins (IQR 69-157) at the spoke hospitals and CT acquisition at the spoke hospital to time of transfer was 93 min (IQR 70-132). 53% of the observed variability in time from CT acquisition at the spoke hospital to transfer to the EVT center was explained by intrinsic hospital factors, as opposed to patient-related factors. CONCLUSIONS: Intrinsic hospital factors explained more than half of the observed variability in time from CT acquisition at the spoke hospital to departure for transfer. We recommend that the design of hub and spoke EVT services should account for intrinsic hospital factors to minimize hospital transfer delay.

Tenecteplase vs Alteplase Before Endovascular Therapy in Basilar Artery Occlusion.

OBJECTIVE: To investigate the efficacy of tenecteplase (TNK), a genetically modified variant of alteplase with greater fibrin specificity and longer half-life than alteplase, prior to endovascular thrombectomy (EVT) in patients with basilar artery occlusion (BAO). METHODS: To determine whether TNK is associated with better reperfusion rates than alteplase prior to EVT in BAO, clinical and procedural data of consecutive patients with BAO from the Basilar Artery Treatment and Management (BATMAN) registry and the Tenecteplase vs Alteplase before Endovascular Therapy for Ischemic Stroke (EXTEND-IA TNK) trial were retrospectively analyzed. Reperfusion >50% or absence of retrievable thrombus at the time of the initial angiogram was evaluated. RESULTS: We included 110 patients with BAO treated with IV thrombolysis prior to EVT (mean age 69 [SD 14] years; median NIH Stroke Scale score 16 [interquartile range (IQR) 7-32]). Nineteen patients were thrombolysed with TNK (0.25 mg/kg or 0.40 mg/kg) and 91 with alteplase (0.9 mg/kg). Reperfusion >50% occurred in 26% (n = 5/19) of patients thrombolysed with TNK vs 7% (n = 6/91) thrombolysed with alteplase (risk ratio 4.0, 95% confidence interval 1.3-12; p = 0.02), despite shorter thrombolysis to arterial puncture time in the TNK-treated patients (48 [IQR 40-71] minutes) vs alteplase-treated patients (110 [IQR 51-185] minutes; p = 0.004). No difference in symptomatic intracranial hemorrhage was observed (0/19 [0%] TNK, 1/91 [1%] alteplase; p = 0.9). CONCLUSIONS: TNK may be associated with an increased rate of reperfusion in comparison with alteplase before EVT in BAO. Randomized controlled trials to compare TNK with alteplase in patients with BAO are warranted. CLINICALTRIALSGOV IDENTIFIERS: NCT02388061 and NCT03340493. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that TNK leads to higher reperfusion rates in comparison with alteplase prior to EVT in patients with BAO.

Association between CYP2C9 polymorphisms and ischemic stroke following endovascular neurointervention.

OBJECTIVE: Polymorphisms in the CYP2C9 gene may be associated with adverse vascular events following endovascular procedures independent of antiplatelet therapy. We aimed to investigate the impact of CYP2C9 loss-of-function polymorphisms on adverse vascular events following neurointervention. PATIENTS AND METHODS: Consecutive patients undergoing neurointervention were prospectively recruited between 2010 and 2016. Patients were genotyped for the CYP2C9*2 and *3 loss-of-function polymorphisms. On the basis of possible genetic influence on antiplatelet response, ex vivo clopidogrel response was measured using the VerifyNow® P2Y12 Assay. The primary endpoint was the 90-day incidence of adverse vascular events including ischemic stroke. RESULTS: A total of 229 patients were included. The median age was 57 years (IQR: 49-64), and 158 (69.00%) were female. Eighty-one (35.37%) patients carried at least one CYP2C9 loss-of-function (LOF) allele. After adjustment for stroke risk factors, the 90-day incidence of ischemic stroke was significantly lower in the LOF group compared to the wild type group (1.23% vs 10.14%; ORadj = 0.16, 95% CI: 0.03-0.91; p = 0.04). CONCLUSIONS: Our results suggest protection against ischemic stroke in carriers of CYP2C9*2 or *3 polymorphisms undergoing neurointervention. Our findings warrant further studies to investigate the mechanisms by which CYP2C9 may influence the risk of ischemic stroke.

Effect of Intravenous Tenecteplase Dose on Cerebral Reperfusion Before Thrombectomy in Patients With Large Vessel Occlusion Ischemic Stroke: The EXTEND-IA TNK Part 2 Randomized Clinical Trial.

Importance: Intravenous thrombolysis with tenecteplase improves reperfusion prior to endovascular thrombectomy for ischemic stroke compared with alteplase. Objective: To determine whether 0.40 mg/kg of tenecteplase safely improves reperfusion before endovascular thrombectomy vs 0.25 mg/kg of tenecteplase in patients with large vessel occlusion ischemic stroke. Design, Setting, and Participants: Randomized clinical trial at 27 hospitals in Australia and 1 in New Zealand using open-label treatment and blinded assessment of radiological and clinical outcomes. Patients were enrolled from December 2017 to July 2019 with follow-up until October 2019. Adult patients (N = 300) with ischemic stroke due to occlusion of the intracranial internal carotid, \basilar, or middle cerebral artery were included less than 4.5 hours after symptom onset using standard intravenous thrombolysis eligibility criteria. Interventions: Open-label tenecteplase at 0.40 mg/kg (maximum, 40 mg; n = 150) or 0.25 mg/kg (maximum, 25 mg; n = 150) given as a bolus before endovascular thrombectomy. Main Outcomes and Measures: The primary outcome was reperfusion of greater than 50% of the involved ischemic territory prior to thrombectomy, assessed by consensus of 2 blinded neuroradiologists. Prespecified secondary outcomes were level of disability at day 90 (modified Rankin Scale [mRS] score; range, 0-6); mRS score of 0 to 1 (freedom from disability) or no change from baseline at 90 days; mRS score of 0 to 2 (functional independence) or no change from baseline at 90 days; substantial neurological improvement at 3 days; symptomatic intracranial hemorrhage within 36 hours; and all-cause death. Results: All 300 patients who were randomized (mean age, 72.7 years; 141 [47%] women) completed the trial. The number of participants with greater than 50% reperfusion of the previously occluded vascular territory was 29 of 150 (19.3%) in the 0.40 mg/kg group vs 29 of 150 (19.3%) in the 0.25 mg/kg group (unadjusted risk difference, 0.0% [95% CI, -8.9% to -8.9%]; adjusted risk ratio, 1.03 [95% CI, 0.66-1.61]; P = .89). Among the 6 secondary outcomes, there were no significant differences in any of the 4 functional outcomes between the 0.40 mg/kg and 0.25 mg/kg groups nor in all-cause deaths (26 [17%] vs 22 [15%]; unadjusted risk difference, 2.7% [95% CI, -5.6% to 11.0%]) or symptomatic intracranial hemorrhage (7 [4.7%] vs 2 [1.3%]; unadjusted risk difference, 3.3% [95% CI, -0.5% to 7.2%]). Conclusions and Relevance: Among patients with large vessel occlusion ischemic stroke, a dose of 0.40 mg/kg, compared with 0.25 mg/kg, of tenecteplase did not significantly improve cerebral reperfusion prior to endovascular thrombectomy. The findings suggest that the 0.40-mg/kg dose of tenecteplase does not confer an advantage over the 0.25-mg/kg dose in patients with large vessel occlusion ischemic stroke in whom endovascular thrombectomy is planned. Trial Registration: ClinicalTrials.gov Identifier: NCT03340493.

Congenital pulmonary airway malformation associated with mosaic Klinefelter syndrome.

A 26-year-old female, G4 P2012 presented for an anatomy scan at 18 weeks. Multiple macrocysts were seen in the left fetal lung, which lead to a diagnosis of congenital pulmonary airway malformation (CPAM) type II. A fetal MRI examination performed at 24 weeks of gestation confirmed the diagnosis of CPAM type II. A genetic amniocentesis was done to rule out a fetal chromosomal abnormality and the fetus was found to have mosaic Klinefelter syndrome. Fetal CPAM is not usually associated with chromosomal abnormalities unless there are other fetal malformations present. This is the first known case where a fetus with CPAM and no other malformation was found to have mosaic Klinefelter syndrome. Therefore, we believe it is prudent to offer prenatal diagnostic testing whenever a fetus with CPAM is identified with ultrasound.

Response to Late-Window Endovascular Revascularization Is Associated With Collateral Status in Basilar Artery Occlusion.

Background and Purpose- The benefit of endovascular therapy in extended time windows has been demonstrated in patients with anterior circulation large vessel occlusion ischemic stroke and favorable imaging profile. We evaluated whether collaterals and thrombus burden influence the associations between revascularization, time-to-treatment, and outcome in endovascular therapy-treated patients with basilar artery occlusion. Methods- We retrospectively analyzed clinical and imaging data of consecutive endovascular therapy-treated patients with basilar artery occlusion included in the multicenter Basilar Artery Treatment and Management Collaboration. The BATMAN (Basilar Artery on Computed Tomography Angiography score, which evaluates thrombus burden and collaterals) and the PC-CS (Posterior Circulation Collateral score, which evaluates collaterals) were assessed on computed tomography angiography, blinded to clinical outcome. Good outcome was defined as modified Rankin Scale score of ≤3 within 3 months; revascularization (successful reperfusion) as modified Thrombolysis in Cerebral Infarction 2b-3 (or TIMI [Thrombolysis in Myocardial Infarction] 2-3 in the BASICS [Basilar Artery International Cooperation Study] registry). Results- We included 172 patients with basilar artery occlusion treated with endovascular therapy (124 with mechanical thrombectomy): mean (SD) age 65 (13) years, median National Institutes of Health Stroke Scale 22 (interquartile range 12-30), 64 (37%) treated >6 hours. Revascularization (achieved in 79% of patients) was associated with good outcome (P=0.003). The use of new generation thrombectomy devices was associated with good outcome (P=0.03). In patients who achieved revascularization, 29/46 (63%) of patients with a favorable BATMAN score and 26/51 (51%) with favorable PC-CS had good outcomes. In logistic regression analysis (adjusted for age, National Institutes of Health Stroke Scale, and time-to-treatment ≤6/>6 hours), revascularization was associated with good outcome in patients with favorable BATMAN score (odds ratio, 15.8; 95% CI, 1.4-175; P=0.02) or PC-CS (odds ratio, 9.4; 95% CI, 1.4-64; P=0.02). In patients who achieved revascularization, early (time-to-treatment ≤6 hours) but not late treatment was associated with improved outcome in patients with unfavorable BATMAN score (18/52 [35%]; odds ratio, 15; 95% CI, 1.9-124; P=0.01) or PC-CS (16/44 [36%]; odds ratio, 5.5; 95% CI, 1.4-21; P=0.01). Conclusions- Revascularization is associated with good outcome in patients with basilar artery occlusion with good collaterals and less extensive occlusion, even >6 hours after onset.

Cerebral blood volume lesion extent predicts functional outcome in patients with vertebral and basilar artery occlusion.

BACKGROUND: CT perfusion may improve diagnostic accuracy in posterior circulation stroke. The posterior circulation Acute Stroke Prognosis Early CT score (pc-ASPECTS) on Computed Tomography Angiography source images (CTA-SI) predicts functional outcome in patients with basilar artery occlusion. AIMS: We assessed the prognostic value of pc-ASPECTS on CT perfusion in patients with vertebral and basilar artery occlusion (VBAO) in comparison with CTA-SI. METHODS: Whole-brain CT perfusion from consecutive stroke patients with VBAO at four stroke centers was retrospectively analyzed. pc-ASPECTS - a 10-point score assessing hypoattenuation on CTA-SI - was calculated from CT perfusion parameters as focally reduced cerebral blood flow or cerebral blood volume, focally increased time to peak of the deconvolved tissue residue function (Tmax) or mean transit time. Two investigators independently reviewed the images. Reliability was assessed with intraclass correlation coefficient. Good outcome was defined as modified Rankin scale ≤3 at three months. RESULTS: We included 60 patients with VBAO. After assessment of four CT perfusion maps simultaneously, area-under-ROC curve (AROC) was 0.83 (95%CI 0.72-0.93) for cerebral blood volume, 0.76 (95%CI 0.64-0.89) for cerebral blood flow, 0.77 (95%CI 0.64-0.89) for Tmax, 0.70 (95%CI 0.56-0.84) for mean transit time versus area-under-ROC curve 0.64 (95%CI 0.50-0.79) for CTA-SI. Cerebral blood volume had greater accuracy compared with CTA-SI for poor outcome (p = 0.04). In logistic regression analysis, cerebral blood volume pc-ASPECTS≤8 was independently associated with poor outcome (OR 9.3 95%CI 2.2-41; p = 0.003, adjusted for age and clinical severity). Inter-rater agreement was substantial for cerebral blood volume pc-ASPECTS (intraclass correlation coefficient 0.82 95%CI 0.71-0.90 versus 0.67 for CTA-SI 95%CI 0.43-0.81). CONCLUSIONS: Cerebral blood volume pc-ASPECTS may identify VBAO patients at higher risk of disability.

Endovascular clot retrieval in acute stroke with large ischaemic core is not always associated with poor outcomes.

BACKGROUND: The benefits of endovascular clot retrieval (ECR) for anterior circulation stroke with large ischaemic cores remain uncertain. In spite of recent pooled analysis of randomised controlled studies, conclusions regarding the fate of large ischaemic cores cannot be reached given the small number of included patients. AIM: To evaluate outcomes of ECR in acute stroke with large ischaemic core. METHODS: This was a single centre retrospective study of patients treated with ECR in the period 2012-2017. The inclusion criteria were anterior circulation stroke with symptom onset less than 6 h, baseline computed tomography perfusion and a 90-day clinical follow up defined by the modified Rankin score. RESULTS: Two hundred and sixty-one patients were included. Median age of 72 (interquartile range: 61-78) and 59% were male. The mean ischaemic core volume was 27.6 mL (SD: 34.9 mL). There were 235 patients with an ischaemic core volume of <70 mL and 26 patients with an ischaemic core volume of ≥70 mL. There was no statistically significant difference; however, in a 90-day functional independence with 66% (154/235) in the <70 mL core group and 54% (14/26) in the ≥70 mL core group reaching a 90-day modified Rankin score ≤2. CONCLUSIONS: We found that patients selected for ECR with ischaemic core size ≥70 mL had clinical outcomes not significantly different compared with those with smaller ischaemic cores. We recommend that large ischaemic core size alone does not necessarily constitute an absolute contraindication for ECR. Randomised controlled studies are needed to define better the benefits for this group of patients.

Safety of Endovascular Thrombectomy for Acute Ischaemic Stroke in Anticoagulated Patients Ineligible for Intravenous Thrombolysis.

BACKGROUND/AIM: Endovascular thrombectomy may be performed in anticoagulated patients taking vitamin-K antagonists (VKA) or direct-acting oral anticoagulants (DOAC) in whom the use of intravenous tissue plasminogen activator (tPA) is contraindicated. We aimed to investigate the efficacy and safety of mechanical thrombectomy specifically in anticoagulated patients ineligible for thrombolysis. METHODS: We performed a retrospective analysis of a prospectively collected database of consecutive ischaemic stroke patients undergoing mechanical thrombectomy from January 2008 to June 2017. Patients receiving any dose of intravenous or intra-arterial thrombolysis were excluded. Patients taking oral anticoagulants (VKAs or DOACs) were compared with non-anticoagulated patients. Outcomes compared between groups included the rate of intracerebral haemorrhage (ICH) on follow-up imaging (ICHany), symptomatic ICH, functional independence at 90 days (modified Rankin scale score, 0-2), mortality, and post-treatment recanalization (Thrombolysis in Cerebral Infarction score ≥2b). RESULTS: In all, 102 patients undergoing mechanical thrombectomy without prior thrombolysis were included in the study. Sixty-six (64.7%) patients were not anticoagulated, 23 (22.5%) patients were taking VKAs, and 13 (12.7%) patients were taking DOACs. There were no significant differences in the rate of ICHany (11.1 vs. 13.6%, p = 0.93) or sICH (2.8 vs. 1.5%, p = 0.14) in anticoagulated patients compared to non-anticoagulated patients. No cases of sICH were observed among patients taking DOACs. After 90 days of follow-up, the rates of functional independence (50.0 vs. 43.1%) and mortality (27.8 vs. 25.8%) were also similar between the anticoagulation and the non-anticoagulation groups. CONCLUSION: Mechanical thrombectomy appears to be safe and effective in anticoagulated patients ineligible for thrombolysis, with observed haemorrhage rates similar to those of patients not on anticoagulant therapy. However, further multicentre prospective studies are needed, due to the rising number of patients on warfarin and DOACs worldwide.

Endovascular Clot Retrieval by Hub-and-Spoke Service Delivery is Feasible Compared with Direct-to-Mothership.

BACKGROUND: Endovascular clot retrieval (ECR) improves outcomes for acute ischaemic stroke with large artery occlusion. However, the provision of ECR requires resource-intensive comprehensive stroke centres (CSC), which are impractical to establish in regional hospitals. An alternative is a "hub-and-spoke" model, whereby ischaemic strokes are triaged at the regional primary centres and where eligible, transferred to a CSC. We aimed to compare the outcomes of patients directly admitted to a CSC with patients treated in the "hub-and-spoke" model. We hypothesize that there are no significant differences in clinical outcomes between the 2 systems. METHODS: We included patients undergoing ECR at a CSC. Patients were categorised into 2 groups; the first group included patients directly admitted to the CSC and the second group included patients in the "hub-and-spoke" model. Good clinical outcome was defined as modified Rankin Scale 0-2 and the difference between the 2 groups was tested by logistic regression. RESULTS: Of 178 patients, 50 (28%) presented directly to CSC and 128 (72%) were transferred from a referring hospital. The median age was 70 (interquartile range 58-77) and 61% were male. Thrombolysis in ischaemic cerebral-infarction 2b/3 recanalisation was achieved in 79% of patients. Of the direct group, 63% (95% CI 48-77%) achieved good clinical outcomes compared to 52% (95% CI 43-61%) in the "hub-and-spoke" group (p = 0.233). CONCLUSION: This state-wide service model demonstrates comparable clinical outcomes to that described in clinical trials. We found no significant difference in outcome between patients directly admitted to CSC and those with "hub-and-spoke" service delivery.