Evaluation of a prehospital endovascular therapy stroke bypass program.

INTRODUCTION: Prehospital stroke endovascular therapy bypass transports patients with suspected large vessel occlusion directly to an endovascular therapy capable center. Our objective was to determine if an endovascular therapy bypass protocol improved access to stroke treatments. Secondary objectives were to determine safety, effectiveness, and rate of subsequent interfacility transfers. METHODS: Endovascular therapy bypass in 2018 was implemented in Eastern Ontario, for patients with a Los-Angeles-Motor-Scale ≥ 4 (positive large vessel occlusion screen) with a 90-min transport time if < 6 h from last seen well. A before-after health record review was conducted from Dec 1, 2017 to Nov 30, 2019. A piloted data form was used to extract demographics, times, primary outcomes (endovascular therapy and intravenous (IV) tissue plasminogen activator (tPA) rate), and secondary outcomes (redirect to closer hospital, airway intervention, and subsequent interfacility transfer). We present descriptive statistics and odds ratios (OR) with 95% confidence intervals (CI) from multivariable logistic regression. RESULTS: We included 379 stroke patients (165 pre and 214 post-implementation). The endovascular therapy rate between groups was similar (14.1% vs 15.1%). The bypass had an OR of 0.98 (95% CI 0.54-1.78) for receiving endovascular therapy. IV tPA was given to 25.4% of patients pre vs 27.4% post-implementation (OR 1.06, 95% CI 0.65-1.74). No patients became unstable during transport, only one patient had an intubation attempt. The inappropriate bypass (false positive) rate was 12.7% pre vs 12.8% post-implementation (positive predictive value 87%). The bypass protocol had an OR of 1.06 (95% CI 0.58-1.95) for subsequent interfacility transfer with a mean of 2.7 h at the community site before transfer. CONCLUSIONS: Endovascular therapy stroke bypass with 90-min transport radius and Los-Angeles-Motor-Scale ≥ 4 was safe and well executed by paramedics. Our study did not show any difference in endovascular therapy rate from its implementation. The IV tPA rate was similar between groups despite potentially bypassing thrombolysis capable centers.

ABSTRAIT: INTRODUCTION: Le pontage de la thérapie endovasculaire pré-hospitalière transporte les patients présentant une occlusion suspectée de gros vaisseaux directement vers un centre capable de thérapie endovasculaire. Notre objectif était de déterminer si un protocole de pontage endovasculaire améliore l'accès aux traitements d'AVC. Les objectifs secondaires étaient de déterminer l'innocuité, l'efficacité et le taux des transferts d'interfacilité subséquents. MéTHODES: Le pontage par thérapie endovasculaire en 2018 a été mis en œuvre dans l'Est de l'Ontario, pour les patients ayant un test Los-Angeles-Motor-Scale 4 (test positif d'occlusion des gros vaisseaux) avec un temps de transport de 90 minutes si < 6 heures après la dernière observation. Un examen du dossier de santé avant-après a été effectué du 1er décembre 2017 au 30 novembre 2019. Un formulaire de données pilote a été utilisé pour extraire les données démographiques, les heures, les résultats primaires (traitement endovasculaire et taux d'activation du plasminogène par voie intraveineuse (IV) et les résultats secondaires (réorientation vers un hôpital plus proche, intervention sur les voies respiratoires et transfert d'interfacilité subséquent). Nous présentons des statistiques descriptives et des rapports de cotes (RC) avec des intervalles de confiance (IC) à 95 % à partir d'une régression logistique multivariée. RéSULTATS: Nous avons inclus 379 AVC (165 avant et 214 après la mise en œuvre). Le taux de traitement endovasculaire entre les groupes était similaire (14,1 % vs 15,1 %). Le pontage avait un RC de 0,98 (IC à 95 %, 0,54-1,78) pour le traitement endovasculaire. Le tPA IV a été administré à 25,4% des patients avant vs 27,4% après la mise en œuvre (OR 1,06, 95%CI 0,65-1,74). Aucun patient n'est devenu instable pendant le transport, seulement 1 patient a eu une tentative d'intubation. Le taux de pontage inapproprié (faux positif) était de 12,7 % avant et de 12,8 % après la mise en œuvre (valeur prédictive positive de 87 %). Le protocole de contournement avait un RC de 1,06 (IC à 95 % 0,58-1,95) pour le transfert d'interfacilité ultérieur avec une moyenne de 2,7 heures sur le site de la communauté avant le transfert. CONCLUSIONS: Le pontage d'AVC de thérapie endovasculaire avec un rayon de transport de 90 minutes et Los-Angeles-Motor-Scale 4 était sûr et bien exécuté par les ambulanciers. Notre étude n'a montré aucune différence dans le taux de thérapie endovasculaire par rapport à sa mise en œuvre. Le taux de tPA IV était similaire entre les groupes malgré le fait que les centres capables de contourner la thrombolyse étaient potentiellement contournés.

Clinical uncertainty in large vessel occlusion ischemic stroke: does automated perfusion imaging make a difference? An intra-rater and inter-rater agreement study.

BACKGROUND: Limited research exists regarding the impact of neuroimaging on endovascular thrombectomy (EVT) decisions for late-window cases of large vessel occlusion (LVO) stroke. OBJECTIVE: T0 assess whether perfusion CT imaging: (1) alters the proportion of recommendations for EVT, and (2) enhances the reliability of EVT decision-making compared with non-contrast CT and CT angiography. METHODS: We conducted a survey using 30 patients drawn from an institutional database of 3144 acute stroke cases. These were presented to 29 Canadian physicians with and without perfusion imaging. We used non-overlapping 95% confidence intervals and difference in agreement classification as criteria to suggest a difference between the Gwet AC1 statistics (κG). RESULTS: The percentage of EVT recommendations differed by 1.1% with or without perfusion imaging. Individual decisions changed in 21.4% of cases (11.3% against EVT and 10.1% in favor). Inter-rater agreement (κG) among the 29 raters was similar between non-perfusion and perfusion CT neuroimaging (κG=0.487; 95% CI 0.327 to 0.647 and κG=0.552; 95% CI 0.430 to 0.675). The 95% CIs overlapped with moderate agreement in both. Intra-rater agreement exhibited overlapping 95% CIs for all 28 raters. κG was either substantial or excellent (0.81-1) for 71.4% (20/28) of raters in both groups. CONCLUSIONS: Despite the minimal difference in overall EVT recommendations with either neuroimaging protocol one in five decisions changed with perfusion imaging. Regarding agreement we found that the use of automated CT perfusion images does not significantly impact the reliability of EVT decisions for patients with late-window LVO.

Synthetic data in cancer and cerebrovascular disease research: A novel approach to big data.

OBJECTIVES: Synthetic datasets are artificially manufactured based on real health systems data but do not contain real patient information. We sought to validate the use of synthetic data in stroke and cancer research by conducting a comparison study of cancer patients with ischemic stroke to non-cancer patients with ischemic stroke. DESIGN: retrospective cohort study. SETTING: We used synthetic data generated by MDClone and compared it to its original source data (i.e. real patient data from the Ottawa Hospital Data Warehouse). OUTCOME MEASURES: We compared key differences in demographics, treatment characteristics, length of stay, and costs between cancer patients with ischemic stroke and non-cancer patients with ischemic stroke. We used a binary, multivariable logistic regression model to identify risk factors for recurrent stroke in the cancer population. RESULTS: Using synthetic data, we found cancer patients with ischemic stroke had a lower prevalence of hypertension (52.0% in the cancer cohort vs 57.7% in the non-cancer cohort, p<0.0001), and a higher prevalence of chronic obstructive pulmonary disease (COPD: 8.5% vs 4.7%, p<0.0001), prior ischemic stroke (1.7% vs 0.1%, p<0.001), and prior venous thromboembolism (VTE: 8.2% vs 1.5%, p<0.0001). They also had a longer length of stay (8 days [IQR 3-16] vs 6 days [IQR 3-13], p = 0.011), and higher costs associated with their stroke encounters: $11,498 (IQR $4,440 -$20,668) in the cancer cohort vs $8,084 (IQR $3,947 -$16,706) in the non-cancer cohort (p = 0.0061). A multivariable logistic regression model identified 5 predictors for recurrent ischemic stroke in the cancer cohort using synthetic data; 3 of the same predictors identified using real patient data with similar effect measures. Summary statistics between synthetic and original datasets did not significantly differ, other than slight differences in the distributions of frequencies for numeric data. CONCLUSION: We demonstrated the utility of synthetic data in stroke and cancer research and provided key differences between cancer and non-cancer patients with ischemic stroke. Synthetic data is a powerful tool that can allow researchers to easily explore hypothesis generation, enable data sharing without privacy breaches, and ensure broad access to big data in a rapid, safe, and reliable fashion.

Quality of Life After Intravenous Thrombolysis for Acute Ischemic Stroke: Results From the AcT Randomized Controlled Trial.

BACKGROUND: Recent evidence from thrombolysis trials indicates the noninferiority of intravenous tenecteplase to intravenous alteplase with respect to good functional outcomes in patients with acute stroke. We examined whether the health-related quality of life (HRQOL) of patients with acute stroke differs by the type of thrombolysis treatment received. In addition, we examined the association between the modified Rankin Scale score 0 to 1 and HRQOL and patient-reported return to prebaseline stroke functioning at 90 days. METHODS: Data were from all patients included in the AcT trial (Alteplase Compared to Tenecteplase), a pragmatic, registry-linked randomized trial comparing tenecteplase with alteplase. HRQOL at 90-day post-randomization was assessed using the 5-item EuroQOL questionnaire (EQ5D), which consists of 5 items and a visual analog scale (VAS). EQ5D index values were estimated from the EQ5D items using the time tradeoff approach based on Canadian norms. Tobit regression and quantile regression models were used to evaluate the adjusted effect of tenecteplase versus alteplase treatment on the EQ5D index values and VAS score, respectively. The association between return to prebaseline stroke functioning and the modified Rankin Scale score 0 to 1 and HRQOL was quantified using correlation coefficient (r) with 95% CI. RESULTS: Of 1577 included in the intention-to-treat analysis patients, 1503 (95.3%) had complete data on the EQ5D. Of this, 769 (51.2%) were administered tenecteplase and 717 (47.7%) were female. The mean EQ5D VAS score and EQ5D index values were not significantly higher for those who received intravenous tenecteplase compared with those who received intravenous alteplase (P=0.10). Older age (P<0.01), more severe stroke assessed using the National Institutes of Health Stroke Scale (P<0.01), and longer stroke onset-to-needle time (P=0.004) were associated with lower EQ5D index and VAS scores. There was a strong association (r, 0.85 [95% CI, 0.81-0.89]) between patient-reported return to prebaseline functioning and modified Rankin Scale score 0 to 1 Similarly, there was a moderate association between return to prebaseline functioning and EQ5D index (r, 0.45 [95% CI, 0.40-0.49]) and EQ5D VAS scores (r, 0.42 [95% CI, 0.37-0.46]). CONCLUSIONS: Although there is no differential effect of thrombolysis type on patient-reported global HRQOL and EQ 5D-5L index values in patients with acute stroke, sex- and age-related differences in HRQOL were noted in this study. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03889249.

Ninety-Day Stroke or Transient Ischemic Attack Recurrence in Patients Prescribed Anticoagulation in the Emergency Department With Atrial Fibrillation and a New Transient Ischemic Attack or Minor Stroke.

Background For patients with atrial fibrillation seen in the emergency department (ED) following a transient ischemic attack (TIA) or minor stroke, the impact of initiating oral anticoagulation immediately rather than deferring the decision to outpatient follow-up is unknown. Methods and Results We conducted a planned secondary data analysis of a prospective cohort of 11 507 adults in 13 Canadian EDs between 2006 and 2018. Patients were eligible if they were aged 18 years or older, with a final diagnosis of TIA or minor stroke with previously documented or newly diagnosed atrial fibrillation. The primary outcome was subsequent stroke, recurrent TIA, or all-cause mortality within 90 days of the index TIA diagnosis. Secondary outcomes included stroke, recurrent TIA, or death and rates of major bleeding. Of 11 507 subjects with TIA/minor stroke, atrial fibrillation was identified in 11.2% (1286, mean age, 77.3 [SD 11.1] years, 52.4% male). Over half (699; 54.4%) were already taking anticoagulation, 89 (6.9%) were newly prescribed anticoagulation in the ED. By 90 days, 4.0% of the atrial fibrillation cohort had experienced a subsequent stroke, 6.5% subsequent TIA, and 2.6% died. Results of a multivariable logistic regression indicate no association between prescribed anticoagulation in the ED and these 90-day outcomes (composite odds ratio, 1.37 [95% CI, 0.74-2.52]). Major bleeding was found in 5 patients, none of whom were in the ED-initiated anticoagulation group. Conclusions Initiating oral anticoagulation in the ED following new TIA was not associated with lower recurrence rates of neurovascular events or all-cause mortality in patients with atrial fibrillation.

Prospective Validation of Computed Tomography to Identify Patients at High Risk for Stroke After Transient Ischemic Attack or Minor Stroke.

BACKGROUND: Computed tomography (CT) findings of acute and chronic ischemia are associated with subsequent stroke risk in patients with transient ischemic attack. We sought to validate these associations in a large prospective cohort of patients with transient ischemic attack or minor stroke. METHODS: This prospective cohort study enrolled emergency department patients from 13 hospitals with transient ischemic attack who had CT imaging. Primary outcome was stroke within 90 days. Secondary outcomes were stroke within 2 or 7 days. CT findings were abstracted from radiology reports and classified for the presence of acute ischemia, chronic ischemia, or microangiopathy. Multivariable logistic regression was used to test associations with primary and secondary end points. RESULTS: From 8670 prospectively enrolled patients between May 2010 and May 2017, 8382 had a CT within 24 hours. From this total population, 4547 (54%) patients had evidence of acute ischemia, chronic ischemia, or microangiopathy on CT, of whom 175 had a subsequent stroke within 90 days (3.8% subsequent stroke rate; adjusted odds ratio [aOR], 2.33 [95% CI, 1.62-3.36]). This was in comparison to those with CT imaging without ischemia. Findings associated with an increased risk of stroke at 90 days were isolated acute ischemia (6.0%; aOR, 2.42 [95% CI, 1.03-5.66]), acute ischemia with microangiopathy (10.7%; aOR, 3.34 [95% CI, 1.57-7.14]), chronic ischemia with microangiopathy (5.2%; aOR, 1.83 [95% CI, 1.34-2.50]), and acute ischemia with chronic ischemia and microangiopathy (10.9%; aOR, 3.49 [95% CI, 1.54-7.91]). Acute ischemia with chronic ischemia and microangiopathy were most strongly associated with subsequent stroke within 2 days (aOR, 4.36 [95% CI, 1.31-14.54]) and 7 days (aOR, 4.50 [95% CI, 1.73-11.69]). CONCLUSIONS: In patients with transient ischemic attack or minor stroke, CT evidence of acute ischemia with chronic ischemia or microangiopathy significantly increases the risk of subsequent stroke within 90 days of index visit. The combination of all 3 findings results in the greatest early risk.

Spontaneous Recanalization of Internal Carotid Artery Occlusion: A Case Report.

INTRODUCTION: Spontaneous recanalization of an occluded internal carotid artery (ICA) is thought to be unlikely. However, there has been a growing number of reports describing this phenomenon. Despite this, the frequency, time course, and mechanism of spontaneous recanalization remain unknown. In this paper, we describe a patient with a symptomatic recanalization of an occluded left ICA. CASE REPORT: A 70-year-old woman presented with transient speech arrest and right upper extremity weakness related to an occluded ICA. After 3 days, her weakness and aphasia reappeared and worsened transiently. A repeat computed tomography angiography revealed recanalization of the occluded ICA, as well as new ischemic changes in the previously hypoperfused left insular region. This finding changed the management from medical management to revascularization with a stent, after which the patient was discharged home with acetylsalicylic acid and clopidogrel. CONCLUSIONS: Although previously thought to be a rare occurrence, spontaneous recanalization is not uncommon. Further research into this phenomenon as proper identification and characterization of this phenomenon can influence follow-up and management.

Aetiology of extracranial carotid free-floating thrombus in a prospective multicentre cohort.

BACKGROUND: Carotid free-floating thrombi (FFT) in patients with acute transient ischaemic attack (TIA)/stroke have a high risk of early recurrent stroke. Management depends on aetiology, which can include local plaque rupture, dissection, coagulopathy, malignancy and cardioembolism. Our objectives were to classify the underlying aetiology of FFT and to estimate the proportion of patients with underlying stenosis requiring revascularisation. METHODS: We prospectively enrolled consecutive patients presenting to three comprehensive stroke centres with acute TIA/stroke and ipsilateral internal carotid artery FFT. The aetiology of FFT was classified as: carotid atherosclerotic disease, carotid dissection, cardioembolism, both carotid atherosclerosis and cardioembolism, or embolic stroke of uncertain source (ESUS). Patients with carotid atherosclerosis were further subclassified as having ≥50% or <50% stenosis. RESULTS: We enrolled 83 patients with confirmed FFT. Aetiological assessments revealed 66/83 (79.5%) had carotid atherosclerotic plaque, 4/83 (4.8%) had a carotid dissection, 10/83 (12%) had both atrial fibrillation and carotid atherosclerotic plaque and 3/83 (3.6%) were classified as ESUS. Of the 76 patients with atherosclerotic plaque (including those with atrial fibrillation), 40 (52.6%) had ≥50% ipsilateral stenosis. CONCLUSIONS: The majority of symptomatic carotid artery FFT are likely caused by local plaque rupture, more than half of which are associated with moderate to severe carotid stenosis requiring revascularisation. However, a significant number of FFTs are caused by non-atherosclerotic mechanisms warranting additional investigations.

Risk of stroke is low after transient ischemic attack presentation with isolated dizziness.

OBJECTIVE: Stroke presenting as dizziness is a diagnostic challenge in frontline settings, given the multitude of benign conditions that present similarly. The risk of stroke after episodic dizziness is unknown, leading to divergent guidance on optimal workup and management. Prior TIA risk scores have shown a history of dizziness is a negative predictor of subsequent stroke. Our objective was to assess the subsequent stroke risk within 90 days following emergency department assessment (ED) for isolated dizziness diagnosed as TIA during the index visit. METHODS: We conducted prospective, multicenter cohort studies at 13 Canadian EDs over 11 years. We enrolled patients diagnosed with TIA and compared patients with isolated dizziness to those with other neurological deficits. Our primary outcome was subsequent stroke within 90 days. Secondary outcomes were subsequent stroke within 2, 7, and 30 days, respectively, as well as subsequent TIA within 90 days. RESULTS: Only 4/483 (0.8%) patients with isolated dizziness had a stroke within 90 days compared to 320/11024 (2.9%) of those with any focal neurological sign or symptom (RR 0.29, 95% CI 0.11-0.76). Over the first 90 days, the two groups differ significantly in their probability of stroke (p = 0.007). Subsequent TIA was also significantly less common in the isolated dizziness group (1.7% vs. 5.6%, p = 0.001) with a relative risk of 0.30 (95% CI 0.15-0.60). CONCLUSION: The risk of subsequent stroke following ED presentation for TIA is low when the presenting symptoms are isolated dizziness.

RéSUMé: OBJECTIF: Les accidents vasculaires cérébraux (AVC) se présentant sous forme de vertiges constituent un défi diagnostique en première ligne, étant donné la multitude d'affections bénignes qui se présentent de la même manière. Le risque d'accident vasculaire cérébral (AVC) après des vertiges épisodiques est inconnu, ce qui donne lieu à des conseils divergents sur le bilan et la prise en charge optimaux. Des scores de risque d'AIT antérieurs ont montré que des antécédents de vertiges sont un facteur prédictif négatif d'accident vasculaire cérébral ultérieur. Notre objectif était d'évaluer le risque ultérieur d'accident vasculaire cérébral (AVC) dans les 90 jours suivant l'évaluation aux urgences d'un étourdissement isolé diagnostiqué comme un AIT lors de la visite de référence. MéTHODES: Nous avons mené des études de cohorte prospectives multicentriques dans 13 services d'urgence canadiens pendant 11 ans. Nous avons recruté des patients ayant reçu un diagnostic d'AIT et avons comparé les patients présentant des vertiges isolés à ceux présentant d'autres déficits neurologiques. Nous avons inscrit des patients ayant reçu un diagnostic d'AIT et comparé des patients ayant des étourdissements isolés à ceux présentant d'autres déficits neurologiques. Notre résultat primaire était l'AVC subséquent dans les 90 jours. Les résultats secondaires étaient l'AVC subséquent dans les 2, 7 et 30 jours, respectivement, ainsi que l'AIT subséquent dans les 90 jours. RéSULTATS: Seuls 4/483 (0,8 %) des patients présentant des vertiges isolés ont eu un AVC dans les 90 jours, contre 320/11 024 (2,9 %) de ceux présentant un signe ou symptôme neurologique focal (RR 0,29, IC 95 % 0,11-0,76). Au cours des 90 premiers jours, les deux groupes diffèrent significativement en termes de probabilité d'AVC (p = 0,007). L'AIT ultérieur était également significativement moins fréquent dans le groupe des vertiges isolés (1,7 % contre 5,6 %, p = 0,001) avec un risque relatif de 0,30 (IC 95 % 0,15-0,60). CONCLUSIONS: Le risque d'AVC ultérieur après une présentation aux urgences pour un AIT est faible lorsque les symptômes présentés sont des étourdissements isolés.

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

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

Predictors of neurologists confirming or overturning emergency physicians' diagnosis of TIA or stroke.

BACKGROUND: Transient ischemic attack (TIA) and non-disabling stroke are common emergency department (ED) presentations. Currently, there are no prospective multicenter studies determining predictors of neurologists confirming a diagnosis of cerebral ischemia in patients discharged with a diagnosis of TIA or stroke. The objectives were to (1) calculate the concordance between emergency physicians and neurologists for the outcome of diagnosing TIA or stroke, and (2) identify characteristics associated with neurologists diagnosing a stroke mimic. METHODS: This was a planned sub-study of a prospective cohort study at 14 Canadian EDs enrolling patients diagnosed with TIA or non-disabling stroke from 2006 to 2017. Logistic regression was used to identify factors associated with neurologists' diagnosis of cerebral ischemia. Our primary outcome was the composite outcome of cerebral ischemia (TIA or non-disabling stroke) based on the neurologists' assessment. RESULTS: The diagnosis of cerebral ischemia was confirmed by neurologists in 5794 patients (55.4%). The most common identified stroke mimics were migraine (18%), peripheral vertigo (7%), syncope (4%), and seizure (3%). Over a third of patients (38.4%) ultimately had an undetermined aetiology for their symptoms. The strongest predictors of cerebral ischemia confirmation were infarct on CT (OR 1.83, 95% CI 1.65-2.02), advanced age (OR comparing 75th-25th percentiles 1.67, 1.55-1.80), language disturbance (OR 1.92, 1.75-2.10), and smoking (OR 1.67, 1.46-1.91). The strongest predictors of stroke mimics were syncope (OR 0.59, 0.48-0.72), vertigo (OR 0.52, 0.45-0.59), bilateral symptoms (OR 0.60, 0.50-0.72), and confusion (OR 0.50, 0.44-0.57). CONCLUSION: Physicians should have a high index of suspicion of cerebral ischemia in patients with advanced age, smoking history, language disturbance, or infarcts on CT. Physicians should discriminate in which patients to pursue stroke investigations on when deemed at minimal risk of cerebral ischemia, including those with isolated vertigo, syncope, or bilateral symptoms.

RéSUMé: CONTEXTE: L'accident ischémique transitoire (AIT) et l'accident vasculaire cérébral (AVC) non invalidant sont des présentations courantes dans les services d'urgence. Actuellement, il n'existe pas d'études prospectives multicentriques déterminant les facteurs prédictifs de la confirmation par les neurologues d'un diagnostic d'ischémie cérébrale chez les patients sortis de l'hôpital avec un diagnostic d'AIT ou d'AVC. Les objectifs étaient de (1) calculer la concordance entre les urgentistes et les neurologues pour le résultat du diagnostic de l'AIT ou de l'AVC, et (2) identifier les caractéristiques associées au diagnostic par les neurologues d'une imitation d'AVC. MéTHODES: Il s'agissait d'une sous-étude planifiée d'une étude de cohorte prospective dans 14 services d'urgence canadiens recrutant des patients diagnostiqués avec un AIT ou un AVC non invalidant de 2006 à 2017. Une régression logistique a été utilisée pour identifier les facteurs associés au diagnostic d'ischémie cérébrale par les neurologues. Notre résultat principal était le résultat composite de l'ischémie cérébrale (AIT ou accident vasculaire cérébral non invalidant) selon l'évaluation des neurologues. RéSULTATS: Le diagnostic d'ischémie cérébrale a été confirmé par des neurologues chez 5 794 patients (55,4 %). Les imitateurs d'AVC identifiés les plus courants étaient la migraine (18 %), le vertige périphérique (7 %), la syncope (4 %) et les convulsions (3 %). Plus d'un tiers des patients (38,4 %) avaient finalement une étiologie indéterminée pour leurs symptômes. Les prédicteurs les plus forts de la confirmation de l'ischémie cérébrale étaient l'infarctus au scanner (OR 1.83, IC 95 % 1.65­2.02), l'âge avancé (OR comparant les 75e et 25e percentiles 1.67, 1.55­1.80), les troubles du langage (OR 1.92, 1.75­2.10) et le tabagisme (OR 1.67, 1.46­1.91). Les prédicteurs les plus forts d'imitateurs d'AVC étaient la syncope (OR 0.59, 0.48­0.72), le vertige (OR 0.52, 0.45­0.59), les symptômes bilatéraux (OR 0.60, 0.50­0.72) et la confusion (OR 0.50, 0.44­0.57). CONCLUSION: Les médecins devraient avoir un indice élevé de suspicion d'ischémie cérébrale chez les patients ayant un âge avancé, des antécédents de tabagisme, des troubles du langage ou des infarctus au scanner. Les médecins doivent distinguer les patients sur lesquels poursuivre des investigations sur un AVC lorsqu'ils sont jugés à risque minimal d'ischémie cérébrale, y compris ceux présentant des vertiges isolés, une syncope ou des symptômes bilatéraux.

Differentiating Carotid Free-Floating Thrombus From Atheromatous Plaque Using Intraluminal Filling Defect Length on CTA: A Validation Study.

OBJECTIVE: To validate a previously proposed filling defect length threshold of >3.8 mm on CT angiography (CTA) to discriminate between free-floating thrombus (FFT) and plaque of atheroma. METHODS: This was a prospective multicenter observational study of 100 participants presenting with TIA/stroke symptoms and a carotid intraluminal filling defect on initial CTA. Follow-up CTA was obtained within 1 week and at weeks 2 and 4 if the intraluminal filling defect was unchanged in length. Resolution or decreased length was diagnostic of FFT, whereas its static appearance after 4 weeks was indicative of plaque. Diagnostic accuracy of FFT length was assessed by receiver operating characteristic analysis. RESULTS: Ninety-five participants (mean [SD] age 68 [13] years, 61 men, 83 participants with FFT, 12 participants with a plaque) were evaluated. The >3.8-mm threshold had a sensitivity of 88% (73 of 83) (95% confidence interval [CI] 78%-94%) and specificity of 83% (10 of 12) (95% CI 51%-97%) (area under the curve 0.91, p < 0.001) for the diagnosis of FFT. The optimal length threshold was >3.64 mm with a sensitivity of 89% (74 of 83) (95% CI 80%-95%) and specificity of 83% (10 of 12) (95% CI 51%-97%). Adjusted logistic regression showed that every 1-mm increase in intraluminal filling defect length is associated with an increase in odds of FFT of 4.6 (95% CI 1.9-11.1, p = 0.01). CONCLUSION: CTA enables accurate differentiation of FFT vs plaque using craniocaudal length thresholds. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov Identifier: NCT02405845. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that in patients with TIA/stroke symptoms, the presence of CTA-identified filling defects of lengths >3.8 mm accurately discriminates FFT from atheromatous plaque.

Clinical Utility and Cost of Inpatient Transthoracic Echocardiography Following Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: It is unclear whether it is clinically necessary or cost-effective to routinely obtain a transthoracic echocardiogram (TTE) during inpatient admission for ischemic stroke. METHODS: We assessed consecutive patients presenting with acute ischemic stroke at a comprehensive stroke center from 2015 to 2017 who underwent TTE. We assessed for findings on TTE that would warrant urgent intervention including cardiac thrombus, atrial myxoma, mitral stenosis, valve vegetation, valve dysfunction requiring surgery, and low ejection fraction. Subsequent changes in management included changes in anticoagulation, antibiotics, or valve surgery. We calculated in-hospital resource utilization and associated costs for inpatient TTE using individual direct cost details within a case-costing system. RESULTS: Of 695 patients admitted with acute ischemic stroke, 516 (74%) had a TTE and were included in our analysis. TTE findings were potentially clinically significant in 30 patients (5.8%) and changed management in 17 patients (3.3%). Inpatient admission was prolonged to expedite TTE in 24 patients, while TTE occurred after discharge in 76 patients. After correcting for the cost of TTE, the mean difference in cost to prolong an admission for TTE was $555.52 (USD), or $16 832 per change in management. CONCLUSIONS: Given the low clinical utility of inpatient TTE after acute ischemic stroke and the costs associated with prolonging admission, discharge from hospital should not be delayed solely to obtain TTE.

Prospective validation of Canadian TIA Score and comparison with ABCD2 and ABCD2i for subsequent stroke risk after transient ischaemic attack: multicentre prospective cohort study.

OBJECTIVE: To validate the previously derived Canadian TIA Score to stratify subsequent stroke risk in a new cohort of emergency department patients with transient ischaemic attack. DESIGN: Prospective cohort study. SETTING: 13 Canadian emergency departments over five years. PARTICIPANTS: 7607 consecutively enrolled adult patients attending the emergency department with transient ischaemic attack or minor stroke. MAIN OUTCOME MEASURES: The primary outcome was subsequent stroke or carotid endarterectomy/carotid artery stenting within seven days. The secondary outcome was subsequent stroke within seven days (with or without carotid endarterectomy/carotid artery stenting). Telephone follow-up used the validated Questionnaire for Verifying Stroke Free Status at seven and 90 days. All outcomes were adjudicated by panels of three stroke experts, blinded to the index emergency department visit. RESULTS: Of the 7607 patients, 108 (1.4%) had a subsequent stroke within seven days, 83 (1.1%) had carotid endarterectomy/carotid artery stenting within seven days, and nine had both. The Canadian TIA Score stratified the risk of stroke, carotid endarterectomy/carotid artery stenting, or both within seven days as low (risk ≤0.5%; interval likelihood ratio 0.20, 95% confidence interval 0.09 to 0.44), medium (risk 2.3%; interval likelihood ratio 0.94, 0.85 to 1.04), and high (risk 5.9% interval likelihood ratio 2.56, 2.02 to 3.25) more accurately (area under the curve 0.70, 95% confidence interval 0.66 to 0.73) than did the ABCD2 (0.60, 0.55 to 0.64) or ABCD2i (0.64, 0.59 to 0.68). Results were similar for subsequent stroke regardless of carotid endarterectomy/carotid artery stenting within seven days. CONCLUSION: The Canadian TIA Score stratifies patients' seven day risk for stroke, with or without carotid endarterectomy/carotid artery stenting, and is now ready for clinical use. Incorporating this validated risk estimate into management plans should improve early decision making at the index emergency visit regarding benefits of hospital admission, timing of investigations, and prioritisation of specialist referral.

Decreased Stroke Presentation Rates at a Comprehensive Stroke Center during COVID-19.

We reviewed stroke care delivery during the COVID-19 pandemic at our stroke center and provincial telestroke system. We counted referrals to our prevention clinic, code strokes, thrombolysis, endovascular thrombectomies, and activations of a provincial telestroke system from February to April of 2017-2020. In April 2020, there was 28% reduction in prevention clinic referrals, 32% reduction in code strokes, and 26% reduction in telestroke activations compared to prior years. Thrombolysis and endovascular thrombectomy rates remained constant. Fewer patients received stroke services across the spectrum from prevention, acute care to telestroke care in Ontario, Canada, during the COVID-19 pandemic.

Prevalence and the predictive performance of the dynamic CT-angiography spot sign in an observational cohort with intracerebral hemorrhage.

The CT-angiography (CTA) spot sign is a predictor of hematoma expansion (HE). We have previously reported on the use of dynamic CTA (dCTA) to detect spot sign, and to study its formation over the acquisition period. In this study, we report the frequency of dCTA spot sign in acute intracerebral hemorrhage, its sensitivity and specificity to predict HE, and explore the rate of contrast extravasation in relation to hematoma growth.We enrolled consecutive patients presenting with primary intracerebral hemorrhage within 4.5 hours. All patients underwent a dCTA protocol acquired over 60 seconds following contrast injection. We calculated frequency of the dCTA spot sign, predictive performance, and rate of contrast extravasation. We compared extravasation rates to the dichotomous definition of significant HE (defined as 6 mL or 33% growth).In 78 eligible patients, dCTA spot sign frequency was 44.9%. In 61 patients available for expansion analysis, sensitivity and specificity of dCTA spot sign was 65.4% and 62.9%, respectively. Contrast extravasation rate did not significantly predict HE (Odds Ratio 15.6 for each mL/min [95% confidence interval 0.30-820.25], P = .17). Correlation between extravasation rate and HE was low (r = 0.297, P= .11). Patients with significant HE had a higher rate of extravasation as compared to those without (0.12 mL/min vs 0.04 mL/min, P = .03).Dynamic CTA results in a higher frequency of spot sign positivity, but with modest sensitivity and specificity to predict expansion. Extravasation rate is likely related to HE, but a single measurement may be insufficient to predict the magnitude of expansion.

Cohort Study of Features Used by Experts to Diagnose Transient Ischemic Attack.

BACKGROUND AND PURPOSE: The diagnosis of transient ischemic attack (TIA) is largely dependent on a process of clinical decision-making that remains poorly characterized in the absence of a validated and accessible biomarker or imaging test. We performed a retrospective chart review to identify variables associated with a final neurologist diagnosis of TIA/stroke. METHODS: Records for all patients seen in The Ottawa Hospital's Stroke Prevention Clinic in 2015 were analyzed for patient and referral characteristics, features of the presenting neurological event, and final diagnosis by a stroke neurologist (classified as definite, possible, or definite not TIA/stroke). Multinomial logistic regression analysis with backward elimination was used to identify variables associated with the final diagnosis. RESULTS: Our inclusion criteria were met by 1894 patients. After backward elimination, 23 potentially important variables were identified, including monocular vision loss (odds ratio [OR]: 30.4, 95% confidence interval [CI]: 14.6-63.3), symptoms of sudden onset (OR: 28.3, 95% CI: 14.2-56.2), unilateral weakness affecting 2 or 3 of face, arm, or leg (OR: 17.7, 95% CI: 9.8-31.7), and homonymous hemianopia (OR: 16.6, 95% CI: 8.1-34.0). CONCLUSIONS: Accurate diagnosis of TIA is essential to initiating appropriate secondary stroke prevention therapies. A focus on elements of the patient history most commonly associated with a final diagnosis of TIA/stroke may help to identify patients in greatest need of urgent SPC assessment and allow for the provision of effective and efficient stroke prevention services.

Diagnosis of Transient Ischemic Attack: Sex-Specific Differences From a Retrospective Cohort Study.

BACKGROUND AND PURPOSE: Research suggests that women and men may present with different transient ischemic attack (TIA) and stroke symptoms. We aimed to explore symptoms and features associated with a definite TIA/stroke diagnosis and whether those associations differed by sex. METHODS: We completed a retrospective cohort study of patients referred to The Ottawa Hospital Stroke Prevention Clinic in 2015. Exploratory multinomial logistic regression was used to evaluate candidate variables associated with diagnosis and patient sex. Backwards elimination of the interaction terms with a significance level for staying in the model of 0.25 was used to arrive at a more parsimonious model. RESULTS: Based on 1770 complete patient records, sex-specific differences were noted in TIA/stroke diagnosis based on features such as duration of event, suddenness of symptom onset, unilateral sensory loss, and pain. CONCLUSIONS: This preliminary work identified sex-specific differences in the final diagnosis of TIA/stroke based on common presenting symptoms/features. More research is needed to understand if there are biases or sex-based differences in TIA/stroke manifestations and diagnosis.

Distribution and predictive performance of the temporal phase of dynamic spot sign appearance in acute intracerebral hemorrhage.

BACKGROUND: Dynamic CT angiography (dCTA) contrast extravasation, known as the "dynamic spot sign", can predict hematoma expansion (HE) in intracerebral hemorrhage (ICH). Recent reports suggest the phase of spot sign appearance is related to the magnitude of HE. We used dCTA to explore the association between the phase of spot sign appearance and HE, clinical outcome, and contrast extravasation rates. METHODS: We assessed consecutive patients who presented with primary ICH within 4.5 hours from symptom onset who underwent a standardized dCTA protocol and were spot sign positive. The independent variable was the phase of spot sign appearance. The primary outcome was significant HE (either 6 mL or 33% growth). Secondary outcomes included total absolute HE, mortality, and discharge mRS. Mann-Whitney U, Fisher's exact test, and logistic regression were used, as appropriate. RESULTS: Of the 35 patients with spot signs, 27/35 (77%) appeared in the arterial phase and 8/35 (23%) appeared in the venous phase. Thirty patients had follow-up CT scans. Significant HE was seen in 14/23 (60.87%) and 3/7 (42.86%) of arterial and venous cohorts, respectively (p = 0.67). The sensitivity and specificity in predicting significant HE were 82% and 31% for the arterial phase and 18% and 69% for the venous phase, respectively. There was a non-significant trend towards greater total HE, in-hospital mortality, and discharge mRS of 4-6 in the arterial spot sign cohort. Arterial spot signs demonstrated a higher median contrast extravasation rate (0.137 mL/min) compared to venous spot signs (0.109 mL/min). CONCLUSION: Our exploratory analyses suggest that spot sign appearance in the arterial phase may be more likely associated with HE and poorer prognosis in ICH. This may be related to higher extravasation rates of arterial phase spot signs. However, further studies with larger sample sizes are warranted to confirm the findings.

A Delayed Modified ICH Score Outperforms Baseline Scoring in Acute Intracerebral Hemorrhage.

The Modified Intracerebral Hemorrhage (MICH) score is a simple tool created to provide prognostication in basal ganglia hemorrhages. Current prognostic scores, including the MICH, are based on the assessment of baseline patient characteristics, failing to account for significant developments, such as intraventricular extension and clinical deterioration, which may occur over the first 72 hours. We propose to validate the MICH in all hemorrhage locations and hypothesize that its calculation at 72 hours will outperform its baseline counterpart with respect to predicting mortality and functional outcome. We performed a retrospective analysis of collated data from the Virtual International Stroke Trials Archive database. Primary outcome was 90-day mortality. Secondary outcome was poor outcome (modified Rankin Scale 4-6) at 90 days. Receiver operating characteristic curves were generated looking at the predictive ability of the MICH score for mortality and poor outcome, at baseline and at 72 hours. Competing curves were assessed with nonparametric methods. A total of 226 patients were included, with a 90-day mortality of 22.5%. The MICH scores calculated at 72 hours were more predictive of mortality than at baseline (area under the curve [AUC]: 0.89 [95% confidence interval [CI]: 0.83-0.94] vs 0.78 [95% CI: 0.70-0.85]), P < .01. The MICH scores at 72 hours similarly better predicted functional outcome (AUC: 0.78 [95% CI: 0.72-0.84] vs AUC: 0.72 [95% CI: 0.66-0.78]), P = .047. The MICH score has positive prognostic value for mortality and poor functional outcome in all hemorrhage locations. Delaying its calculation resulted in higher predictive values for both and suggests that delaying discussions around withdrawal of care may result in more accurate prognostication in acute intracerebral hemorrhage.