Trial of Thrombectomy for Stroke with a Large Infarct of Unrestricted Size.

BACKGROUND: The use of thrombectomy in patients with acute stroke and a large infarct of unrestricted size has not been well studied. METHODS: We assigned, in a 1:1 ratio, patients with proximal cerebral vessel occlusion in the anterior circulation and a large infarct (as defined by an Alberta Stroke Program Early Computed Tomographic Score of ≤5; values range from 0 to 10) detected on magnetic resonance imaging or computed tomography within 6.5 hours after symptom onset to undergo endovascular thrombectomy and receive medical care (thrombectomy group) or to receive medical care alone (control group). The primary outcome was the score on the modified Rankin scale at 90 days (scores range from 0 to 6, with higher scores indicating greater disability). The primary safety outcome was death from any cause at 90 days, and an ancillary safety outcome was symptomatic intracerebral hemorrhage. RESULTS: A total of 333 patients were assigned to either the thrombectomy group (166 patients) or the control group (167 patients); 9 were excluded from the analysis because of consent withdrawal or legal reasons. The trial was stopped early because results of similar trials favored thrombectomy. Approximately 35% of the patients received thrombolysis therapy. The median modified Rankin scale score at 90 days was 4 in the thrombectomy group and 6 in the control group (generalized odds ratio, 1.63; 95% confidence interval [CI], 1.29 to 2.06; P<0.001). Death from any cause at 90 days occurred in 36.1% of the patients in the thrombectomy group and in 55.5% of those in the control group (adjusted relative risk, 0.65; 95% CI, 0.50 to 0.84), and the percentage of patients with symptomatic intracerebral hemorrhage was 9.6% and 5.7%, respectively (adjusted relative risk, 1.73; 95% CI, 0.78 to 4.68). Eleven procedure-related complications occurred in the thrombectomy group. CONCLUSIONS: In patients with acute stroke and a large infarct of unrestricted size, thrombectomy plus medical care resulted in better functional outcomes and lower mortality than medical care alone but led to a higher incidence of symptomatic intracerebral hemorrhage. (Funded by Montpellier University Hospital; LASTE ClinicalTrials.gov number, NCT03811769.).

Long-term clinical and ultrasound follow-up after transient perivascular inflammation of the carotid artery (TIPIC) syndrome: a multicenter study.

BACKGROUND: The present study aimed to describe the clinical and ultrasound (US) long-term follow-up of patients with transient perivascular inflammation of the carotid artery (TIPIC) syndrome and the risk of recurrence. METHODS: We enrolled patients with a definitive diagnosis of TIPIC syndrome who were included in a retrospective multicenter study. These patients were recontacted at least six months after the first TIPIC episode for a clinical and imaging follow-up. Each patient underwent a clinical evaluation through a tailored questionnaire as well as US imaging. RESULTS: Twenty-eight patients were enrolled with a median follow-up of 58.7 months (interquartile range = 8-121). Nineteen out of the 28 patients (67.8%) had residual pain, eight (28.6%) had experienced a clinical recurrence and 12 (42.9%) had a thickening of the carotid wall on US. No patients had neurological complication or other associated diseases. CONCLUSIONS: Patients with TIPIC syndrome have often residual pain and recurrence in about one quarter of cases but the long-term follow-up is in favor a benign self-limited pathology.Trial registration: ClinicalTrials.gov (identifier NCT03804112).

Dual-layer carotid stenting for symptomatic carotid web: Results from the Caroweb study.

BACKGROUND & PURPOSE: Carotid Web (CaW) is a growingly recognized cause of ischemic stroke, associated with a high recurrence risk. Several therapeutic strategies have been proposed as a tertiary prevention including carotid stenting, endarterectomy and antithrombotic medications. Among these, carotid stenting with dual-layer stent may be promising to adequately cover the focal arterial dysplasia. Our aim was to investigate the safety and efficacy of the Casper stent in the treatment of symptomatic CaW. METHODS: We conducted a retrospective analysis of consecutive patients presenting with a symptomatic CaW and included in the ongoing prospective observational multicenter CAROWEB registry. The study period was January 2015 to December 2021. Inclusion criteria were CaW treated with dual-layer Casper stent. Patients treated with other types of carotid stent, endarterectomy or antithrombotic medication were excluded. Clinical and radiological initial data and outcomes were recorded. RESULTS: twenty-seven patients (with 28 caw) were included. median age was 52 (iqr: 46-68). median delay between index cerebrovascular event and cervical stenting was 9 days (IQR: 6-101). In all cases, the cervical carotid stenting was successfully performed. No major perioperative complication was recorded. No recurrent stroke or transient ischemic attack was observed during a median follow-up time of 272 days (IQR: 114-635). Long-term imaging follow-up was available in 25/28 (89.3%) stented CaW with a median imaging follow-up of 183 days (IQR: 107-676; range: 90-1542). No in-stent occlusion or stenosis was detected. CONCLUSION: In this study, carotid stenting with dual-layer Casper stent in the treatment of symptomatic CaW was effective regarding stroke recurrence prevention and safe, without procedural nor delayed detected adverse event. However, the optimal therapeutic approach of symptomatic CaW still needs to be explored through randomized trials.

Should Patients With Acute Minor Ischemic Stroke With Isolated Internal Carotid Artery Occlusion Be Thrombolysed?

BACKGROUND: We recently reported a worrying 30% rate of early neurological deterioration (END) occurring within 24 hours following intravenous thrombolysis (IVT) in minor stroke with isolated internal carotid artery occlusion (ie, without additional intracranial occlusion), mainly due to artery-to-artery embolism. Here, we hypothesize that in this setting IVT-as compared to no-IVT-may foster END, in particular by favoring artery-to-artery embolism from thrombus fragmentation. METHODS: From a large multicenter retrospective database, we compared minor stroke (National Institutes of Health Stroke Scale score <6) isolated internal carotid artery occlusion patients treated within 4.5 hours of symptoms onset with either IVT or antithrombotic therapy between 2006 and 2020 (inclusion date varied among centers). Primary outcome was END within 24 hours (≥4 National Institutes of Health Stroke Scale points increase within 24 hours), and secondary outcomes were END within 7 days (END7d) and 3-month modified Rankin Scale score 0 to 1. RESULTS: Overall, 189 patients were included (IVT=95; antithrombotics=94 [antiplatelets, n=58, anticoagulants, n=36]) from 34 centers. END within 24 hours and END7d occurred in 46 (24%) and 60 (32%) patients, respectively. Baseline clinical and radiological variables were similar between the 2 groups, except significantly higher National Institutes of Health Stroke Scale (median 3 versus 2) and shorter onset-to-imaging (124 versus 149min) in the IVT group. END within 24 hours was more frequent following IVT (33% versus 16%, adjusted hazard ratio, 2.01 [95% CI, 1.07-3.92]; P=0.03), driven by higher odds of artery-to-artery embolism (20% versus 9%, P=0.09). However, END7d and 3-month modified Rankin Scale score of 0 to 1 did not significantly differ between the 2 groups (END7d: adjusted hazard ratio, 1.29 [95% CI, 0.75-2.23]; P=0.37; modified Rankin Scale score of 0-1: adjusted odds ratio, 1.1 [95% CI, 0.6-2.2]; P=0.71). END7d occurred earlier in the IVT group: median imaging-to-END 2.6 hours (interquartile range, 1.9-10.1) versus 20.4 hours (interquartile range, 7.8-34.4), respectively, P<0.01. CONCLUSIONS: In our population of minor strokes with iICAO, although END rate at 7 days and 3-month outcome were similar between the 2 groups, END-particularly END due to artery-to-artery embolism-occurred earlier following IVT. Prospective studies are warranted to further clarify the benefit/risk profile of IVT in this population.

Leptomeningeal enhancement on post-contrast FLAIR images for early diagnosis of Susac syndrome.

BACKGROUND: Leptomeningeal enhancement (LME) is a key feature of Susac syndrome (SuS) but is only occasionally depicted on post-contrast T1-weighted images (T1-WI). OBJECTIVE: As post-contrast fluid-attenuated inversion recovery (FLAIR) may be more sensitive, our aim was to assess LME in SuS on this sequence. METHODS: From 2010 to 2020, 20 patients with definite SuS diagnosis were retrospectively enrolled in this multicentre study. Two radiologists independently assessed the number of LME on post-contrast FLAIR and T1-WI acquisitions performed before any treatment. A chi-square test was used to compare both sequences and the interrater agreement was calculated. RESULTS: Thirty-five magnetic resonance imagings (MRIs) were performed before treatment, including 19 post-contrast FLAIR images in 17 patients and 25 post-contrast T1-WI in 19 patients. In terms of patients, LME was observed on all post-contrast FLAIR, contrary to post-contrast T1-WI (17/17 (100%) vs. 15/19 (79%), p < 0.05). In terms of sequences, LME was observed on all post-contrast FLAIR, contrary to post-contrast T1-WI (19/19 (100%) vs. 16/25 (64%), p < 0.005). LME was disseminated at both supratentorial (19/19) and infratentorial (18/19) levels on post-contrast FLAIR, contrary to post-contrast T1-WI (3/25 and 9/25, respectively). Interrater agreement was excellent for post-contrast FLAIR (κ = 0.95) but only moderate for post-contrast T1-WI (κ = 0.61). CONCLUSION: LME was always observed and easily visible on post-contrast FLAIR images prior to SuS treatment. In association with other MRI features, it is highly indicative of SuS.

Transient perivascular inflammation of the carotid artery (TIPIC) syndrome.

Background: The Transient Perivascular Inflammation of the Carotid artery (TIPIC) syndrome is presumably a very rare disease characterized by a local transient inflammation of the tissue around the carotid artery. Its pathophysiology remains unknown. We performed an updated study of TIPIC syndrome cases in the setting of a multinational collaborative study. Methods: This study was conducted as an observational multinational retrospective individual patient level cohort study. Information from all known cases diagnosed with TIPIC syndrome in the literature (2005-2020) was collected after a semi-structured literature search of PubMed and Web of Science. We also collected unpublished information of patients from French, Swiss, and Italian vascular medicine or radiology departments. Results: A total of 72 patients were included and served for data analysis: 42 (58.3%) were women; the mean age was 47.9 (SD=11.4) years. Symptoms were unilateral in 92% of patients and 81.4% required pain killers. At baseline, irrespective of the imaging method used, the median thickness of the carotid lesions was 5 (Q1-Q3: 4-7; range: 2-11) mm and the median length of the lesion was 20 (Q1-Q3: 10-30; range: 3-50) mm. We found a positive linear correlation between thickness and length. At follow-up, the thickness of the carotid lesions decreased to a median of 2 (Q1-Q3: 1-3; range: 0-6) mm; the length decreased to a median 10 (Q1-Q3: 5-15; range: 0-41) mm. A linear correlation between baseline and follow-up values was observed for both thickness and length measurements. Symptoms disappeared after a median of 14 (Q1-Q3: 10-15) days. Thirteen patients experienced a recurrence after a median follow-up of 6 (Q1-Q3: 2-12) months. Conclusions: The present analysis elucidates clinical and sonographic characteristics of TIPIC syndrome, indicating the benign nature of this condition. A future international registry will study the long-term course of the disease.

Cardiac involvement in Wilson disease: Review of the literature and description of three cases of sudden death.

Wilson disease (WD) is a rare genetic condition that results from a build-up of copper in the body. It requires life-long treatment and is mainly characterized by hepatic and neurological features. Copper accumulation has been reported to be related to the occurrence of heart disease, although little is known regarding this association. We have conducted a systematic review of the literature to document the association between WD and cardiac involvement. Thirty-two articles were retained. We also described three cases of sudden death. Cardiac manifestations in WD include cardiomyopathy (mainly left ventricular (LV) remodeling, hypertrophy, and LV diastolic dysfunction, and less frequently LV systolic dysfunction), increased levels of troponin, and/or brain natriuretic peptide, electrocardiogram (ECG) abnormalities, and rhythm or conduction abnormalities, which can be life-threatening. Dysautonomia has also been reported. The mechanism of cardiac damage in WD has not been elucidated. It may be the result of copper accumulation in the heart, and/or it could be due to a toxic effect of copper, resulting in the release of free oxygen radicals. Patients with signs and/or symptoms of cardiac involvement or who have cardiovascular risk factors should be examined by a cardiologist in addition to being assessed by their interdisciplinary treating team. Furthermore, ECG, cardiac biomarkers, echocardiography, and 24-hours or more of Holter monitoring at the diagnosis and/or during the follow-up of patients with WD need to be evaluated. Cardiac magnetic resonance imaging, although not always available, could also be a useful diagnostic tool, allowing assessment of the risk of ventricular arrhythmias and further guidance of the cardiac workup.

Vascular origin in acute transient visual disturbance: A prospective study.

BACKGROUND AND PURPOSE: This study was undertaken to validate a clinical score of vascular origin in patients with acute transient visual disturbances (TVDs) without diplopia. METHODS: We conducted a prospective study in an ophthalmology emergency department and a transient ischemic attack (TIA) clinic. Patients underwent clinical evaluation including a tailored questionnaire, brain, vascular, and ophthalmologic investigations, and 3-month follow-up. TVDs were classified according to vascular or nonvascular origin by three independent experts based on all clinical, cerebrovascular, and ophthalmologic investigations, but blind to the questionnaire results. A clinical score was derived based on clinical variables independently associated with a vascular origin, and was externally validated in an independent cohort. RESULTS: An ischemic origin of TVD was found in 45% (67/149) of patients in the derivation cohort. Age and six questions were independently associated with an ischemic origin. A nine-point score (≥70 years old = 2; monocular visual loss = 2; black or white vision = 1; single episode = 1; lack of headache = 2; diffuse, constricted, altitudinal, or lateralized visual loss pattern on drawings = 1) showed good discriminative power in identifying ischemic origin (c-statistic = 0.82) and was replicated in the validation cohort (n = 130, 25% of ischemic origin, c-statistic = 0.75). With a score ≥ 4, sensitivity was 85% (95% confidence interval = 68-95) and specificity was 52% (95% confidence interval = 41-62). In both cohorts, ophthalmologic evaluation found a vascular cause in 4% and was noncontributive in 85%. After 3 months, no patients had a stroke, TIA, or retinal infarct. CONCLUSIONS: Our score may assist in predicting a vascular origin of TVD. Ophthalmologic evaluation, when not readily available, should not delay the neurovascular evaluation.

Clinical Outcome of Acute Ischemic Strokes in Patients with COVID-19.

INTRODUCTION: Acute ischemic stroke (AIS) and thrombotic events (TEs) were reported in patients with COVID-19. Clinical outcome of AIS in the course of COVID-19 remains unknown. We compared early clinical outcome and mortality of COVID-positive (+) patients admitted for AIS with COVID-negative (-) ones. We hypothesized that COVID+ patients would have poorer clinical outcomes and present a higher rate of TEs and mortality compared with COVID- ones. METHODS: In this multicentric observational retrospective study, we enrolled patients over 18 years old admitted for AIS in 3 stroke units of the Parisian region during lockdown from March 17, 2020, to May 2, 2020. COVID-19 status as well as demographic, clinical, biological, and imaging data was collected retrospectively from medical records. Poor outcome was defined as modified Rankin score (mRS) 3-6 (3-6) at discharge. We also compared TE frequency and mortality rate through a composite criterion in both groups. RESULTS: Two hundred and sixteen patients were enrolled; mean age was 68 years old, and 63% were male. Forty patients were CO-VID+ (18.5%) and 176 were COVID-. Obesity was statistically more frequent in the COVID+ group (36 vs. 13% p < 0.01). The percentage of patients with mRS (3-6) at discharge was higher in the COVID+ group compared with the COVID- group (60 vs. 41%, p = 0.034). The main predictor of presenting a mRS (3-6) at discharge was high NIHSS score at admission (OR, CI 95%: 1.325, 1.22-1.43). Mortality rate was higher in the COVID+ group (12 vs. 3.4%, p = 0.033) as well as TE frequency (15 vs. 2.8%, p < 0.01). CONCLUSION: In this study, patients with AIS infected by SARS-CoV-2 showed a poorer early outcome than COVID- ones. However, when compared to other factors, COVID-19 was not a significant predictor of poor outcome. Vascular morbidity and mortality rates were significantly higher in the COVID+ group compared with the COVID- group.

Antiplatelet Therapy During Emergent Extracranial Internal Carotid Artery Stenting: Comparison of Three Intravenous Antiplatelet Perioperative Strategies.

INTRODUCTION: Guidelines for antiplatelet therapy administration, during emergent stenting for extra-cranial internal carotid artery (EC-ICA) occlusion in the setting of acute ischemic stroke (AIS) are lacking. Different antiplatelet regimen are used in association to endovascular therapy (EVT) for the treatment of EC-ICA lesions. We aimed to compare the clinical and radiological effects of three intravenous antiplatelet agents used during emergent EC-ICA stenting. MATERIAL AND METHODS: Clinical data were collected from January 2015 to December 2019 in a monocentric prospective registry of AIS patients treated by EVT. All patients who underwent emergent EC-ICA stenting were sorted regarding the intravenous antiplatelet agent used during the procedure. RESULTS: Among 218 patients treated by EVT for an EC-ICA occlusion of the anterior circulation during the study period, 70 underwent an emergent stenting of the EC-ICA. 60 were included in the present study, 9 received intravenous (IV) Cangrelor, 8 IV abciximab and 43 Aspirin. The rate of favorable neurological outcome, defined as modified Rankin Scale (mRS) ≤ 2 at three months were better in the Cangrelor and Aspirin groups (66,7% and 58,1%, respectively) than in the Abciximab group (37,5%), as well as, the rate of any intracranial ICH (22,2% and 37,2% vs 62,5%). The rate of acute stent reocclusion was similar between groups. CONCLUSION: When used as a rescue treatment during emergent stenting of EC-ICA, Cangrelor and Aspirin present a better safety profile than Abciximab, with less intracranial hemorrhages and a higher rate of good clinical outcome. Additional studies are needed to confirm these findings.

Improved detection and characterization of arterial occlusion in acute ischemic stroke using contrast enhanced MRA.

BACKGROUND AND PURPOSE: To compare the accuracy and utility of contrast enhanced magnetic resonance angiography (MRA) (CEMRA) to Time of Flight MRA (TOF MRA) during detection and evaluation of occlusions on patients diagnosed with acute ischemic stroke (AIS). METHODS: This single-center study was approved by our local institutional research ethics board. From August 2014 to July 2016, 131 consecutive adult patients with confirmed AIS were included. Detection of an arterial occlusion and its characterization were evaluated independently with CEMRA or TOF MRA by two blinded neuroradiologists, then by consensus using all available MR sequences. A Cohen's Kappa coefficient (κ) and intra-class correlation coefficients (ICC) were used to compare the two techniques. RESULTS: There was substantial concordance in the detection of arterial occlusion between CEMRA and TOF MRA (κ = 0.75). TOF MRA was more likely to show an arterial occlusion than CEMRA (63 versus 52 patients respectively). There were 13 and 1 false positive arterial occlusion with TOF MRA and CEMRA respectively, and 1 false negative with TOF MRA. There was excellent concordance between the location of arterial occlusions and CEMRA and TOF MRA [κ = 0.89 (0.72-0.97)]. CEMRA was significantly more likely to allow measurement of the thrombus than was TOF MRA [38 (75%) versus 14 (22%)] (P < 0.0001). CONCLUSIONS: Our study showed that CEMRA imaging detected arterial occlusions better than TOF MRA in AIS patients and more precisely such that thrombus length and location could be known, which improves the patient's management and care.

Thrombus Length Predicts Lack of Post-Thrombolysis Early Recanalization in Minor Stroke With Large Vessel Occlusion.

Background and Purpose- Whether bridging therapy, that is, intravenous thrombolysis [IVT] followed by mechanical thrombectomy, is beneficial as compared with IVT alone in minor stroke (National Institutes of Health Stroke Scale ≤5) with large vessel occlusion is unknown and should be tested in randomized trials. To help select the most appropriate candidates for such trials, we aimed to identify strong predictors of lack of post-IVT early recanalization (ER)-a surrogate marker of poor outcome. Methods- From a large multicenter French registry of patients with large vessel occlusion referred for thrombectomy immediately after IVT start between 2015 and 2017, we extracted 97 minor strokes with ER evaluated on first angiographic run or noninvasive imaging ≤3 hours from IVT start. Thrombus length was measured using the susceptibility vessel sign on T2* imaging. Results- Median National Institutes of Health Stroke Scale was 3 (interquartile range, 2-4), and occlusion sites were proximal (intracranial carotid or M1) and distal (M2) in 50% and 50% of patients, respectively. On pre-IVT MRI, median length of susceptibility vessel sign (visible in 90%) was 9.2 mm (interquartile range, 7.4-13.3). ER was present in 34% of patients, and susceptibility vessel sign length was the only clinical or radiological variable associated with no-ER after stepwise variable selection into a multivariable model (odds ratio, 1.53 per 1-mm increase; 95% CI, 1.21-1.92; P<0.001). The C statistic of susceptibility vessel sign length for no-ER prediction was 0.82 (95% CI, 0.73-0.92), and the optimal cutoff (Youden) was 9 mm. Sensitivity and specificity of this cutoff for no-ER were 67.8% (95% CI, 55.9-79.7) and 84.6% (95% CI, 70.7-98.5), respectively. Conclusions- ER was frequent in this cohort of IVT-treated minor stroke patients with large vessel occlusion considered for thrombectomy, and thrombus length was a powerful independent predictor of no-ER. These findings may help design randomized trials aiming to test bridging therapy versus IVT alone in this population.

Efficacy of Endovascular Therapy in Acute Ischemic Stroke Depends on Age and Clinical Severity.

BACKGROUND AND PURPOSE: Efficacy of endovascular treatment (EVT) for ischemic stroke because of large vessel occlusion may depend on patients' age and stroke severity; we, therefore, developed a prognosis score based on these variables and examined whether EVT efficacy differs between patients with good, intermediate, or poor prognostic score. METHODS: A total of 4079 patients with an acute ischemic stroke were identified from the Paris Stroke Consortium registry. We developed the stroke checkerboard (SC) score (SC score=1 point per decade ≥50 years of age and 2 points per 5 points on the National Institutes of Health Stroke Scale) to predict spontaneous outcome. The primary outcome was the adjusted common odds ratio for an improvement in the modified Rankin Scale at 90 days after EVT, in patients with low, intermediate, or high SC scores. To rule out potential selection biases, a nested case-control analysis, with individual matching for all major prognostic factors, was also performed, to compare patients with large vessel occlusion in the anterior circulation treated or not with EVT. RESULTS: In patients untreated with EVT, SC scores <8 were predictive of good outcomes (modified Rankin Scale score, 0-2; area under the curve, 0.87), whereas SC scores >12 were predictive of poor outcomes (modified Rankin Scale score, 4-6; area under the curve, 0.88). In the overall population, there was an interaction between EVT and prognosis group (P<0.001). EVT was associated with improved outcome in patients with SC scores >12 (common odds ratio, 1.70; 95% confidence interval, 1.13-2.56) and SC scores 8 to 12 (odds ratio, 1.37; 95% confidence interval, 1.11-1.69) but not in patients with SC scores <8 (odds ratio, 0.72; 95% confidence interval, 0.56-0.93). Similar results were obtained in the case-control analysis among 449 patients treated with EVT and 449 matched patients untreated with EVT. CONCLUSIONS: In patients stratified with the SC score, EVT was associated with improved functional outcome in older and more severe patients but not in younger and less severe patients.

DWI-ASPECTS (Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Scores) and DWI-FLAIR (Diffusion-Weighted Imaging-Fluid Attenuated Inversion Recovery) Mismatch in Thrombectomy Candidates: An Intrarater and Interrater Agreement Study.

BACKGROUND AND PURPOSE: We aimed to study the intrarater and interrater agreement of clinicians attributing DWI-ASPECTS (Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Scores) and DWI-FLAIR (Diffusion-Weighted Imaging-Fluid Attenuated Inversion Recovery) mismatch in patients with acute ischemic stroke referred for mechanical thrombectomy. METHODS: Eighteen raters independently scored anonymized magnetic resonance imaging scans of 30 participants from a multicentre thrombectomy trial, in 2 different reading sessions. Agreement was measured using Fleiss κ and Cohen κ statistics. RESULTS: Interrater agreement for DWI-ASPECTS was slight (κ=0.17 [0.14-0.21]). Four raters (22.2%) had a substantial (or higher) intrarater agreement. Dichotomization of the DWI-ASPECTS (0-5 versus 6-10 or 0-6 versus 7-10) increased the interrater agreement to a substantial level (κ=0.62 [0.48-0.75] and 0.68 [0.55-0.79], respectively) and more raters reached a substantial (or higher) intrarater agreement (17/18 raters [94.4%]). Interrater agreement for DWI-FLAIR mismatch was moderate (κ=0.43 [0.33-0.57]); 11 raters (61.1%) reached a substantial (or higher) intrarater agreement. CONCLUSIONS: Agreement between clinicians assessing DWI-ASPECTS and DWI-FLAIR mismatch may not be sufficient to make repeatable clinical decisions in mechanical thrombectomy. The dichotomization of the DWI-ASPECTS (0-5 versus 0-6 or 0-6 versus 7-10) improved interrater and intrarater agreement, however, its relevance for patients selection for mechanical thrombectomy needs to be validated in a randomized trial.

Post-Thrombolysis Recanalization in Stroke Referrals for Thrombectomy: Incidence, Predictors, and Prediction Scores.

Background and Purpose­Whether all acute stroke patients with large vessel occlusion need to undergo intravenous thrombolysis before mechanical thrombectomy (MT) is debated as (1) the incidence of post-thrombolysis early recanalization (ER) is still unclear; (2) thrombolysis may be harmful in patients unlikely to recanalize; and, conversely, (3) transfer for MT may be unnecessary in patients highly likely to recanalize. Here, we determined the incidence and predictors of post-thrombolysis ER in patients referred for MT and derive ER prediction scores for trial design. Methods­Registries from 4 MT-capable centers gathering patients referred for MT and thrombolyzed either on site (mothership) or in a non MT-capable center (drip-and-ship) after magnetic resonance­ or computed tomography­based imaging between 2015 and 2017. ER was identified on either first angiographic run or noninvasive imaging. In the magnetic resonance imaging subsample, thrombus length was determined on T2*-based susceptibility vessel sign. Independent predictors of no- ER were identified using multivariable logistic regression models, and scores were developed according to the magnitude of regression coefficients. Similar registries from 4 additional MT-capable centers were used as validation cohort. Results­In the derivation cohort (N=633), ER incidence was ≈20%. In patients with susceptibility vessel sign (n=498), no-ER was independently predicted by long thrombus, proximal occlusion, and mothership paradigm. A 6-point score derived from these variables showed strong discriminative power for no-ER (C statistic, 0.854) and was replicated in the validation cohort (n=353; C statistic, 0.888). A second score derived from the whole sample (including negative T2* or computed tomography­based imaging) also showed good discriminative power and was similarly validated. Highest grades on both scores predicted no-ER with >90% specificity, whereas low grades did not reliably predict ER. Conclusions­The substantial ER rate underlines the benefits derived from thrombolysis in bridging populations. Both prediction scores afforded high specificity for no-ER, but not for ER, which has implications for trial design.

Magnetic resonance post-contrast vascular hyperintensities at 3 T: a new highly sensitive sign of vascular occlusion in acute ischaemic stroke.

BACKGROUND: Magnetic resonance imaging (MRI) is the diagnostic cornerstone for precisely identifying acute ischaemic strokes and locating vascular occlusions, especially since mechanical thrombectomy has become a reference treatment. We observed that a post-contrast three-dimensional turbo-spin-echo T1-weighted sequence showed striking post-contrast vascular hyperintensities (PCVH) in ischaemic territories. We aimed to evaluate the prevalence and the meaning of this finding. METHODS: This retrospective single centre study included 130 consecutive patients admitted for acute ischaemic stroke with a 3-T MRI performed in the first 12 h of symptom onset from September 2014 through September 2016. Two neuroradiologists blinded to clinical data analysed the first MRI assessments. The association between PCVH and clinical, radiological and follow-up findings was assessed, as well as inter- and intra-observer agreements. RESULTS: Of 130 patients, 105 (81%) had PCVH in the ischaemic territory. PCVH were associated with the presence of thrombus on susceptibility weighted imaging (p < 0.0001) and vascular occlusions on MR angiography (p < 0.0001). All patients with a visible thrombus had PCVH closely surrounding the clot. PCVH were associated with higher initial (p < 0.01) and follow-up (p < 0.01) National Institutes of Health Stroke Scale score, and higher mRS score (p < 0.05). Thrombectomy was the reference treatment for all patients with arterial occlusions. Inter- and intra-observer agreements for the detection of PCVH were excellent (κ = 0.95 and κ = 0.91, respectively). CONCLUSIONS: PCVH during acute strokes are a striking sensitive and reproducible tool for diagnosing and locating vascular occlusions. It may help triage patients who can benefit from thrombectomy. KEY POINTS: • Post-contrast vascular hyperintensities (PCVH) are a sensitive MR finding in acute stroke • PCVH are strongly associated with the presence and location of arterial occlusions • Inter- and intra-observer agreements for the detection of PCVH are excellent • PCVH are visible even in the case of significant motion artefacts • PCVH may help triage patients who can benefit from mechanical thrombectomy.

Mechanical Thrombectomy for Minor and Mild Stroke Patients Harboring Large Vessel Occlusion in the Anterior Circulation: A Multicenter Cohort Study.

BACKGROUND AND PURPOSE: Proximal large vessel occlusion (LVO) is present in up to 30% of minor strokes. The effectiveness of mechanical thrombectomy (MT) in the subgroup of minor stroke with LVO in the anterior circulation is still open to debate. Data about MT in this subgroup of patients are sparse, and their optimal management has not yet been defined. The purpose of this multicenter cohort study was to evaluate the effectiveness of MT in patients experiencing acute ischemic stroke (AIS) because of LVO in the anterior circulation, presenting with minor-to-mild stroke symptoms (National Institutes of Health Stroke Scale score of <8). METHODS: Multicenter cohort study involving 4 comprehensive stroke centers having 2 therapeutic approaches (urgent thrombectomy associated with best medical treatment [BMT] versus BMT first and MT if worsening occurs) about management of patients with minor and mild acute ischemic stroke harboring LVO in the anterior circulation. An intention-to-treat analysis was conducted. The primary end point was the rate of excellent outcome defined as the achievement of a modified Rankin Scale score of 0 to 1 at 3 months. RESULTS: Three hundred one patients were included, 170 with urgent MT associated with BMT, and 131 with BMT alone as first-line treatment. Patients treated with MT were younger, more often received intravenous thrombolysis, and had shorter time to imaging. Twenty-four patients (18.0%) in the medical group had rescue MT because of neurological worsening. Overall, excellent outcome was achieved in 64.5% of patients, with no difference between the 2 groups. Stratified analysis according to key subgroups did not find heterogeneity in the treatment effect size. CONCLUSIONS: Minor-to-mild stroke patients with LVO achieved excellent and favorable functional outcomes at 3 months in similar proportions between urgent MT versus delayed MT associated with BMT. There is thus an urgent need for randomized trials to define the effectiveness of MT in this patient subgroup.