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Background: Data on the frequency and outcome of mechanical thrombectomy (MT) for large vessel occlusion (LVO) in patients with COVID-19 is limited. Addressing this subject, we report our multicenter experience., Methods: A retrospective cohort study was performed of consecutive acute stroke patients with COVID-19 infection treated with MT at 26 tertiary care centers between January 2020 and November 2021. Baseline demographics, angiographic outcome and clinical outcome evaluated by the modified Rankin Scale (mRS) at discharge and 90 days were noted., Results: We identified 111 out of 11 365 (1%) patients with acute or subsided COVID-19 infection who underwent MT due to LVO. Cardioembolic events were the most common etiology for LVO (38.7%). Median baseline National Institutes of Health Stroke Scale score and Alberta Stroke Program Early CT Score were 16 (IQR 11.5-20) and 9 (IQR 7-10), respectively. Successful reperfusion (mTICI ≥2b) was achieved in 97/111 (87.4%) patients and 46/111 (41.4%) patients were reperfused completely. The procedure-related complication rate was 12.6% (14/111). Functional independence was achieved in 20/108 (18.5%) patients at discharge and 14/66 (21.2%) at 90 days follow-up. The in-hospital mortality rate was 30.6% (33/108). In the subgroup analysis, patients with severe acute COVID-19 infection requiring intubation had a mortality rate twice as high as patients with mild or moderate acute COVID-19 infection. Acute respiratory failure requiring ventilation and time interval from symptom onset to groin puncture were independent predictors for an unfavorable outcome in a logistic regression analysis., Conclusion: Our study showed a poor clinical outcome and high mortality, especially in patients with severe acute COVID-19 infection undergoing MT due to LVO., Competing Interests: Competing interests: MM: Grants or contracts from Balt, Medtronic, MircroVention and Stryker. FD: Consultant for Balt, Cerus Endovascular, Phenox and Cerenovus, honoraria for lectures from Cerenovus, Acandis and Asahi, support for attending meetings from MicroVention, Acandis and Cerus Endovascular, advisory board member for Cerenovus/Johnson & Johnson, associate editor for Journal of NeuroInterventional Surgery. MG: Grants or contracts from Else Kröner Fresenius Stiftung, payment of honoraria for lectures from Phenox, proctoring contract with MircroVention, participation on clinical event committee from MicroVention, chair of ESMINT Examination Committee, received stents from Phenox for research purposes. DK: Grants or contracts from Else Kröner Fresenius Center of Digital Health and Joachim Herz Foundation, spokesman of the “Junge Neuroradiologie” in the German Society of Neuroradiology. CL: Consulting fees, payment of honoraria for lectures and support for attending meetings from Phenox, Penumbra and Acandis. MW: Grants from ab medica, Acandis, Bracco Imaging, Cerenovus, Kaneka Pharmaceuticals, Medtronic, Mentice AB, Microvention, Phenox, Siemens Healthcare and Stryker Neurovascular; Consulting fees from Stryker Healthcare; Payment honoraria for lectures from Stryker Neurovascular. The other authors declare no specific conflict of interest., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The degree of reperfusion is the most important modifiable predictor of 3 month functional outcome and mortality in ischemic stroke patients treated with mechanical thrombectomy. Whether the beneficial effect of reperfusion also leads to a reduction in long term mortality is unknown., Methods: Patients undergoing mechanical thrombectomy between January 2010 and December 2018 were included. The post-thrombectomy degree of reperfusion and emboli in new territories were core laboratory adjudicated. Reperfusion was evaluated according to the expanded Thrombolysis in Cerebral Infarction (eTICI) scale. Vital status was obtained from the Swiss population register. Adjusted hazard ratios (aHRs) using time split Cox regression models were calculated. Subgroup analyses were performed in patients with borderline indications., Results: Our study included 1264 patients (median follow-up per patient 2.5 years). Patients with successful reperfusion had longer survival times, attributable to a lower hazard of death within 0-90 days and for >90 days to 2 years (aHR 0.34, 95% CI 0.26 to 0.46; aHR 0.37, 95% CI 0.22 to 0.62). This association was homogeneous across all predefined subgroups (p for interaction >0.05). Among patients with successful reperfusion, a significant difference in the hazard of death was observed between eTICI2b50 and eTICI3 (aHR 0.51, 95% CI 0.33 to 0.79). Emboli in new territories were present in 5% of patients, and were associated with increased mortality (aHR 2.3, 95% CI 1.11 to 4.86)., Conclusion: Successful, and ideally complete, reperfusion without emboli in new territories is associated with a reduction in long term mortality in patients treated with mechanical thrombectomy, and this was evident across several subgroups., Competing Interests: Competing interests: UF reports grants during the conduct of the study from Medtronic, Stryker, and CSL Behring, unrelated to the submitted work. JG is a global principal investigator of STAR (Solitaire FR Thrombectomy for Acute Revascularisation), Clinical Event Committee member of the PROMISE study (Prospective, Multicenter, Observational, Single-Arm European Registry on the ACE Reperfusion Catheters and the Penumbra System in the Treatment of Acute Ischemic Stroke; Penumbra), and a principal investigator and consultant for the SWIFT DIRECT study (Solitaire With the Intention for Thrombectomy Plus Intravenous tPA Versus DIRECT Solitaire Stent-Retriever Thrombectomy in Acute Anterior Circulation Stroke; Medtronic) and receives Swiss National Science Foundation grants for magnetic resonance imaging in stroke. JK reports grants from the Swiss Academy of Medical Sciences/Bangerter Foundation, Swiss Stroke Society, and Clinical Trials Unit Bern during the conduct of the study. MA reports personal fees from Bayer, Bristol-Myers Squibb, Medtronic, Amgen, Daiichi Sankyo, Nestlé Health Sciences, Boehringer Ingelheim, and Covidien during the conduct of the study. TRM reports research support from the Bangerter Rhyner Foundation, Swiss National Foundation, and the Swiss Heart Foundation. MRH reports research support from the Bangerter Foundation, scientific advisory board honoraria from Amgen, and personal fees from Bayer., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Achieving the best possible reperfusion is a key determinant of clinical outcome after mechanical thrombectomy (MT). However, data on the safety and efficacy of intra-arterial (IA) fibrinolytics as an adjunct to MT with the intention to improve reperfusion are sparse., Methods: We performed a PROSPERO-registered (CRD42020149124) systematic review and meta-analysis accessing MEDLINE, PubMed, and Embase from January 1, 2000 to January 1, 2020. A random-effect estimate (Mantel-Haenszel) was computed and summary OR with 95% CI were used as a measure of added IA fibrinolytics versus control on the risk of symptomatic intracranial hemorrhage (sICH) and secondary endpoints (modified Rankin Scale ≤2, mortality at 90 days)., Results: The search identified six observational cohort studies and three observational datasets of MT randomized-controlled trial data reporting on IA fibrinolytics with MT as compared with MT alone, including 2797 patients (405 with additional IA fibrinolytics (100 urokinase (uPA), 305 tissue plasminogen activator (tPA)) and 2392 patients without IA fibrinolytics). Of 405 MT patients treated with additional IA fibrinolytics, 209 (51.6%) received prior intravenous tPA. We did not observe an increased risk of sICH after administration of IA fibrinolytics as adjunct to MT (OR 1.06, 95% CI 0.64 to 1.76), nor excess mortality (0.81, 95% CI 0.60 to 1.08). Although the mode of reporting was heterogeneous, some studies observed improved reperfusion after IA fibrinolytics., Conclusion: The quality of evidence regarding peri-interventional administration of IA fibrinolytics in MT is low and limited to observational data. In highly selected patients, no increase in sICH was observed, but there is large uncertainty., Competing Interests: Competing interests: Related: UF and JG are global PIs for the SWIFT DIRECT study (Solitaire With the Intention for Thrombectomy Plus Intravenous t-PA Versus DIRECT Solitaire Stent-Retriever Thrombectomy in Acute Anterior Circulation Stroke) supported by Medtronic. Unrelated: JG is a global PI of STAR (Solitaire FR Thrombectomy for Acute Revascularisation Observational study), Clinical Event Committee member of the PROMISE study (European Registry on the ACE Reperfusion Catheters and the Penumbra System in the Treatment of Acute Ischemic Stroke; Penumbra), Consultancy, and receives Swiss National Science Foundation (SNSF) grants for MRI in stroke. UF receives research grants from SNSF and serves as a consultant for Medtronic and Stryker. MA received speaker honoraria from Bayer, Boehringer Ingelheim, and Covidien; advisory board honoraria from Amgen Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Pfizer, Covidien, Daichy Sankyo and Nestlé Health Science; research grant provided by the Swiss Heart Foundation. JK reports grants from SAMW / Bangerter Foundation, the Swiss Stroke Society and non-financial support from Stryker and Pfizer outside the submitted work. DWJD reports funding from the Dutch Heart Foundation, Brain Foundation Netherlands, The Netherlands Organisation for Health Research and Development, Health Holland Top Sector Life Sciences & Health, and unrestricted grants from AngioCare BV, Covidien/EV3®, MEDAC Gmbh/LAMEPRO, Penumbra Inc., Top Medical/Concentric, Stryker, Stryker European Operations BV, Medtronic, Thrombolytic Science, LLC and Cerenovus for research, all paid to institution. MG reports licensing agreement for systems of acute stroke diagnosis for GE Healthcare and Consultancy for Medtronic, Stryker, MicroVention and Mentice as well as unrestricted research grant by Stryker for the UNMASK-EVT study. MDH has a patent Systems and Methods for Assisting in Decision-Making and Triaging for Acute Stroke Patients pending to US patent office number 62/086077 and owns stock in Calgary Scientific, Inc—a company that focuses on medical imaging software., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background and Purpose: Current demographic changes indicate that more people will be care-dependent due to increasing life expectancy. Little is known about impact of preexisting dependency on stroke outcome after endovascular treatment (EVT)., Methods: We compared prospectively collected baseline and outcome data of previously dependent vs. independent stroke patients (prestroke modified Rankin Scale score of 3-5 vs. 0-2) treated with EVT. Outcome measures were favorable 3-month outcome (mRS ≤ 3 for previously dependent and mRS ≤ 2 for independent patients, respectively), death and symptomatic intracranial hemorrhage (sICH)., Results: Among 1247 patients, 84 (6.7%) were dependent before stroke. They were older (81 vs. 72 years of age), more often female (61.9% vs. 46%), had a higher stroke severity at baseline (NIHSS 18 vs. 15 points), more often history of previous stroke (32.9% vs. 9.1%) and more vascular risk factors than independent patients. Favorable outcome and mortality were to the disadvantage of independent patients (26.2% vs. 44.4% and 46.4% vs. 25.5%, respectively), whereas sICH was comparable in both cohorts (4.9% vs. 5%). However, preexisting dependency was not associated with clinical outcome and mortality after adjusting for outcome predictors (OR 1.076, 95% CI 0.612-1.891; p = 0.799 and OR 1.267, 95% CI 0.758-2.119; p = 0.367, respectively)., Conclusion: Our study underscores the need for careful selection of care-dependent stroke patients when considering EVT, given a less favorable outcome observed in this cohort. Nonetheless, EVT should not systematically be withheld in patients with preexisting disability, since prior dependency does not significantly influence outcome.

Background and Purpose: Post hoc analyses of randomized controlled clinical trials evaluating mechanical thrombectomy have suggested that admission-to-groin-puncture (ATG) delays are associated with reduced reperfusion rates. Purpose of this analysis was to validate this association in a real-world cohort and to find associated factors and confounders for prolonged ATG intervals., Methods: Patients included into the BEYOND-SWIFT cohort (Bernese-European Registry for Ischemic Stroke Patients Treated Outside Current Guidelines With Neurothrombectomy Devices Using the Solitaire FR With the Intention for Thrombectomy; https://www.clinicaltrials.gov; Unique identifier: NCT03496064) were analyzed (n=2386). Association between baseline characteristics and ATG was evaluated using mixed linear regression analysis. The effect of increasing symptom-onset-to-admission and ATG intervals on successful reperfusion (defined as Thrombolysis in Cerebral Infarction [TICI] 2b-3) was evaluated using logistic regression analysis adjusting for potential confounders., Results: Median ATG was 73 minutes. Prolonged ATG intervals were associated with the use of magnetic resonance imaging (+19.1 [95% CI, +9.1 to +29.1] minutes), general anesthesia (+12.1 [95% CI, +3.7 to +20.4] minutes), and borderline indication criteria, such as lower National Institutes of Health Stroke Scale, late presentations, or not meeting top-tier early time window eligibility criteria (+13.8 [95% CI, +6.1 to +21.6] minutes). There was a 13% relative odds reduction for TICI 2b-3 (adjusted odds ratio [aOR], 0.87 [95% CI, 0.79-0.96]) and TICI 2c/3 (aOR, 0.87 [95% CI, 0.79-0.95]) per hour ATG delay, while the reduction of TICI 2b-3 per hour increase symptom-onset-to-admission was minor (aOR, 0.97 [95% CI, 0.94-0.99]) and inconsistent regarding TICI 2c/3 (aOR, 0.99 [95% CI, 0.97-1.02]). After adjusting for identified factors associated with prolonged ATG intervals, the association of ATG delay and lower rates of TICI 2b-3 remained tangible (aOR, 0.87 [95% CI, 0.76-0.99])., Conclusions: There is a great potential to reduce ATG, and potential targets for improvement can be deduced from observational data. The association between in-hospital delay and reduced reperfusion rates is evident in real-world clinical data, underscoring the need to optimize in-hospital workflows. Given the only minor association between symptom-onset-to-admission intervals and reperfusion rates, the causal relationship of this association warrants further research. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03496064.

Background and Purpose: Mechanical thrombectomy is an effective recanalization technique in acute ischemic stroke patients with large vessel occlusions; however, it is unclear to what extent stent retriever thrombectomy may be applicable to occlusions of smaller peripheral cerebral vessels. The outcome of patients with isolated M2 occlusions treated with the Mindframe Capture low profile (LP) stent retriever was reviewed., Material and Methods: A retrospective review of prospectively collected data on all consecutive patients treated for isolated M2 occlusions between June 2013 and December 2017 using the Mindframe Capture LP was performed. Technical aspects of the recanalization procedure, recanalization rate, complication rate, and clinical outcome were analyzed., Results: Mechanical thrombectomy with the Mindframe Capture LP was performed in 38 patients (median age 79 years) with an isolated M2 occlusion. The median National Institutes of Health Stroke Scale (NIHSS) score on admission was 7.5 (interquartile range, IQR 5-12) and successful reperfusion modified Thrombolysis in Cerebral Infarction (mTICI 2b or 3) was achieved in 28 patients (74%). A compensated/adjusted modified Rankin Scale (mRS) 0-2 at 3 months was observed in 65% when taking pre-stroke disability into account. Symptomatic intracranial hemorrhage (sICH) occurred in 1 patient (2.6%). Asymptomatic intracranial hemorrhage (aICH) was noted in 8 patients (21%) and a small subarachnoid hemorrhage (SAH) in the immediate vicinity of the target vessel was apparent in 8 patients (21%)., Conclusion: The Mindframe Capture LP is a technically effective thrombectomy device for the treatment of isolated M2 occlusions. The lower profile of the device is advantageous when targeting peripheral intracranial occlusions.

Introduction: A new generation of carotid artery stents that use a dual micromesh layer to reduce embolic events during carotid artery stenting has recently been introduced. We aimed to analyze the effectiveness and safety of the new Casper-RX stent in patients experiencing acute ischemic stroke with large vessel intracranial occlusion associated with a tandem lesion (another carotid occlusion or severe stenosis)., Methods: We retrospectively analyzed all consecutive patients treated with carotid Casper-RX stents from our stroke registry. We analyzed clinical, angiographic, and neuroimaging data. Endpoints included acute intra-stent thrombus formation, stent occlusion prior to hospital discharge, 3 month modified Rankin Scale score (mRS), and symptomatic intracranial hemorrhage., Results: 21 patients were included: 10 patients had tandem carotid occlusions and 11 patients had severe carotid stenosis, 8 of whom had a hemodynamically significant stenosis. We observed acute in-stent thrombus formation in 11 patients. No stent occlusion occurred prior to hospital discharge. We report no stroke recurrence at 3 months but symptomatic intracranial hemorrhage in two patients. mRS score at 3 months was 0-2 (favorable) for 15 patients (71%), 3-5 for 3 patients, and 6 for 3 patients., Conclusions: In the present series, we frequently observed clot formation during the procedure with Casper-RX stents, which required periprocedural intravenous infusion of anticoagulant and antiplatelet treatment. This motivated us, in the absence of a prospective randomized controlled study demonstrating the non-inferiority of micromesh dual layer stents compared with the single layer design, to discontinue using this stent type in acute stroke requiring carotid angioplasty., Competing Interests: Competing interests: PM: speaker and consulting fees from Medtronic, Steering committee of PROMISE (Penumbra). All this support goes to the institution and is used for stroke education and research. The other authors report no conflicts., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: International dose reference levels are lacking for mechanical thrombectomy in acute ischemic stroke patients with large vessel occlusions. We studied whether radiation dose-reduction systems (RDS) could effectively reduce exposure and propose achievable levels., Materials and Methods: We retrospectively included consecutive patients treated with thrombectomy on a biplane angiography system (BP) in five international, high-volume centers between January 2014 and May 2017. Institutional Review Board approvals were obtained. Technical, procedural, and clinical characteristics were assessed. Efficacy, safety, radiation dose, and contrast load were compared between angiography systems with and without RDS. Multivariate analyses were adjusted according to Bonferroni's correction. Proposed international achievable cutoff levels were set at the 75th percentile., Results: Out of the 1096 thrombectomized patients, 520 (47%) were treated on a BP equipped with RDS. After multivariate analysis, RDS significantly reduced dose-area product (DAP) (91 vs 140 Gy cm 2 , relative effect 0.74 (CI 0.66; 0.83), 35% decrease, p < 0.001) and air kerma (0.46 vs 0.97 Gy, relative effect 0.63 (CI 0.56; 0.71), 53% decrease, p < 0.001) with 75th percentile levels of 148 Gy cm 2 and 0.73 Gy, respectively. There was no difference in contrast load, rates of successful recanalization, complications, or clinical outcome., Conclusion: Radiation dose-reduction systems can reduce DAP and air kerma by a third and a half, respectively, without affecting thrombectomy efficacy or safety. The respective thresholds of 148 Gy cm 2 and 0.73 Gy represent achievable levels that may serve to optimize current and future radiation exposure in the setting of acute ischemic stroke treatment. As technology evolves, we expect these values to decrease., Key Points: • Internationally validated achievable levels may help caregivers and health authorities better assess and reduce radiation exposure of both ischemic stroke patients and treating staff during thrombectomy procedures. • Radiation dose-reduction systems can reduce DAP and air kerma by a third and a half, respectively, without affecting thrombectomy efficacy or safety in the setting of acute ischemic stroke due to large vessel occlusion.

Background: In acute ischemic stroke (AIS) collaterals correlate with infarct size, recanalization rate and clinical outcome. We aimed to identify factors associated with better collateral status in a large series of AIS patients with middle cerebral artery (MCA) occlusion., Methods: In the Acute STroke Registry and Analysis of Lausanne (ASTRAL) from 2003 to 2016, we identified all consecutive AIS with proximal MCA occlusion on CT-angiography performed < 24 h. Collaterals were scored from 0 (absent) to 3 (≥ 100%) and related to multiple demographic, clinical, metabolic and radiological variables in a multivariate regression analysis (MVA)., Results: The 857 included patients had a median age of 72.3 years, 48.4% were female and median admission NIHSS was 16. Better collaterals were associated with younger age (OR 0.99; 95% CI 0.98-1.00), hemineglect (OR 1.35; 95% CI 1.03-1.76), absence of visual field defects (OR 0.64; 95% CI 0.46-0.90), eye deviation (OR 0.58; 95% CI 0.43-0.79) and decreased vigilance (OR 0.62; 95% CI 0.44-0.88). Better collaterals were also associated with dyslipidemia (OR 1.57; 95% CI 1.16-2.13), no previous statin use (OR 0.69; 95% CI 0.50-0.95), and lower creatinine levels (OR 0.99; 95% CI 0.99-1.00). On neuroimaging, better collaterals related to higher ASPECTS score (OR 1.27; 95% CI 1.20-1.35) and higher clot burden score (OR 1.09; 95% CI 1.03-1.14)., Conclusions: Younger age, dyslipidemia and lower creatinine levels were predictors of better collaterals in AIS patients from proximal MCA occlusions. Greater degree of collaterals related to lower stroke severity on admission. On neuroimaging, better collaterals were independently associated with minor early ischemic changes and lower clot burden. These data may add knowledge on pathophysiology of collaterals development and may help to identify patients with better collaterals for late or aggressive recanalization treatments.

Background and Purpose- Sustained successful reperfusion is an important prognostic factor for good clinical outcome in acute ischemic stroke. We aimed to identify the prevalence, clinical impact, and predictors of early reocclusion after initially successful thrombectomies within a prospective cohort. Methods- A total of 711 stroke patients with successful reperfusion (modified Thrombolysis in Cerebral Infarction, 2b/3) followed with magnetic resonance or computed tomographic angiography at 24 to 48 hours were included. Multivariable logistic regression analysis was used to evaluate associated factors and clinical impact. Results are displayed as adjusted odds ratio (aOR) and 95% CI. Improvement in accuracy of additional imaging findings on angiography control runs after the intervention was evaluated by area under the curve. Results- Early reocclusion was observed in 16 of 711 successfully reperfused patients (2.3%; 95% CI, 1.1-3.3; median delay: 20 hours). Suggestive predictors were higher platelets on admission (aOR, 1.01; 95% CI, 1.01-1.02), prestroke functional dependence (aOR, 7.12; 95% CI, 1.49-34.03), and stroke of undetermined or other specified pathogenesis in the TOAST classification (aOR, 7.19; 95% CI, 1.10-47.05 and aOR, 36.50; 95% CI, 4.47-298.11, respectively). When implementing residual embolic fragments or stenosis at the thrombectomy site into the logistic regression model, discrimination between patients with and without reocclusion improved significantly (area under the curve, 0.955 versus 0.854; P=0.023). Early reocclusion was an independent predictor of unfavorable outcome at 90 days (aOR for modified Rankin Scale ≤2, 0.13; 95% CI, 0.03-0.57). Conclusions- Early reocclusion within 48 hours after successful mechanical thrombectomy is rare but associated with poor outcome. Patients with high platelets on admission and residual embolic fragments or stenosis at the thrombectomy site are at high risk for reocclusion, which may be prevented or corrected after carefully re-evaluating the last angiographic run.

Background and Purpose: Endovascular treatment (EVT) is a new standard of care for selected, large vessel occlusive strokes. We aimed to determine frequency of potentially eligible patients for intravenous thrombolysis (IVT) and EVT in comprehensive stroke centers. In addition, predictors of EVT eligibility were derived., Methods: Patients from a stroke center-based registry (2003-2014), admitted within 24 hours of last proof of usual health, were selected if they had all data to determine IVT and EVT eligibility according to American Heart Association/American Stroke Association (AHA/ASA) guidelines (class I-IIa recommendations). Moreover, less restrictive criteria adapted from randomized controlled trials and clinical practice were tested. Maximum onset-to-door time windows for IVT eligibility were 3.5 hours (allowing door-to-needle delay of ≤60 minutes) and 4.5 hours for EVT eligibility (door-to-groin delay ≤90 minutes). Demographic and clinical information were used in logistic regression analysis to derive variables associated with EVT eligibility., Results: A total of 2704 patients with acute ischemic stroke were included, of which 26.8% were transfers. Of all patients with stroke arriving at our comprehensive stroke center, a total proportion of 12.4% patients was eligible for IVT. Frequency of EVT eligibility differed between AHA/ASA guidelines and less restrictive approach: 2.9% versus 4.9%, respectively, of all patients with acute ischemic stroke and 10.5% versus 17.7%, respectively, of all patients arriving within <6 hours. Predictors for AHA-EVT eligibility were younger, shorter onset-to-admission delays, higher National Institutes of Health Stroke Scale (NIHSS), decreased vigilance, hemineglect, absent cerebellar signs, atrial fibrillation, smoking, and decreasing glucose levels (area under the curve=0.86)., Conclusions: Of patients arriving within 6 hours at a comprehensive stroke center, 10.5% are EVT eligible according to AHA/ASA criteria, 17.7% according to criteria resembling randomized controlled trials, and twice as many patients are IVT eligible (36.2%)., (© 2016 American Heart Association, Inc.)

Intravenous thrombolysis (IVT) as treatment in acute ischaemic strokes may be insufficient to achieve recanalisation in certain patients. Predicting probability of non-recanalisation after IVT may have the potential to influence patient selection to more aggressive management strategies. We aimed at deriving and internally validating a predictive score for post-thrombolytic non-recanalisation, using clinical and radiological variables. In thrombolysis registries from four Swiss academic stroke centres (Lausanne, Bern, Basel and Geneva), patients were selected with large arterial occlusion on acute imaging and with repeated arterial assessment at 24 hours. Based on a logistic regression analysis, an integer-based score for each covariate of the fitted multivariate model was generated. Performance of integer-based predictive model was assessed by bootstrapping available data and cross validation (delete-d method). In 599 thrombolysed strokes, five variables were identified as independent predictors of absence of recanalisation: Acute glucose > 7 mmol/l (A), significant extracranial vessel STenosis (ST), decreased Range of visual fields (R), large Arterial occlusion (A) and decreased Level of consciousness (L). All variables were weighted 1, except for (L) which obtained 2 points based on β-coefficients on the logistic scale. ASTRAL-R scores 0, 3 and 6 corresponded to non-recanalisation probabilities of 18, 44 and 74 % respectively. Predictive ability showed AUC of 0.66 (95 %CI, 0.61-0.70) when using bootstrap and 0.66 (0.63-0.68) when using delete-d cross validation. In conclusion, the 5-item ASTRAL-R score moderately predicts non-recanalisation at 24 hours in thrombolysed ischaemic strokes. If its performance can be confirmed by external validation and its clinical usefulness can be proven, the score may influence patient selection for more aggressive revascularisation strategies in routine clinical practice.