Interhospital Transfer for Endovascular Stroke Treatment in Canada: Results From the OPTIMISE Registry.

BACKGROUND: Interhospital transfer for patients with stroke due to large vessel occlusion for endovascular thrombectomy (EVT) has been associated with treatment delays. METHODS: We analyzed data from Optimizing Patient Treatment in Major Ischemic Stroke With EVT, a quality improvement registry to support EVT implementation in Canada. We assessed for unadjusted differences in baseline characteristics, time metrics, and procedural outcomes between patients with large vessel occlusion transferred for EVT and those directly admitted to an EVT-capable center. RESULTS: Between January 1, 2018, and December 31, 2021, a total of 6803 patients received EVT at 20 participating centers (median age, 73 years; 50% women; and 50% treated with intravenous thrombolysis). Patients transferred for EVT (n=3376) had lower rates of M2 occlusion (22% versus 27%) and higher rates of basilar occlusion (9% versus 5%) compared with those patients presenting directly at an EVT-capable center (n=3373). Door-to-needle times were shorter in patients receiving intravenous thrombolysis before transfer compared with those presenting directly to an EVT center (32 versus 36 minutes). Patients transferred for EVT had shorter door-to-arterial access times (37 versus 87 minutes) but longer last seen normal-to-arterial access times (322 versus 181 minutes) compared with those presenting directly to an EVT-capable center. No differences in arterial access-to-reperfusion times, successful reperfusion rates (85% versus 86%), or adverse periprocedural events were found between the 2 groups. Patients transferred to EVT centers had a similar likelihood for good functional outcome (modified Rankin Scale score, 0-2; 41% versus 43%; risk ratio, 0.95 [95% CI, 0.88-1.01]; adjusted risk ratio, 0.98 [95% CI, 0.91-1.05]) and a higher risk for all-cause mortality at 90 days (29% versus 25%; risk ratio, 1.15 [95% CI, 1.05-1.27]; adjusted risk ratio, 1.14 [95% CI, 1.03-1.28]) compared with patients presenting directly to an EVT center. CONCLUSIONS: Patients transferred for EVT experience significant delays from the time they were last seen normal to the initiation of EVT.

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.

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.

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.

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.

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.

Early vascular imaging and key system strategies expedite carotid revascularization after transient ischemic attack and stroke.

BACKGROUND: International guidelines recommend carotid revascularization within 14 days for patients with a symptomatic transient ischemic attack (TIA) or stroke event. However, significant delays in care persist, with only 9% of outpatients and 36% of inpatients in Ontario meeting this target. The study objective was to explore the influence of health system factors on carotid revascularization timelines. METHODS: We conducted a retrospective chart review of all symptomatic TIA/stroke patients undergoing carotid endarterectomy or stenting at The Ottawa Hospital (2015-2016). The primary outcome was time from TIA/stroke to carotid revascularization. Health system variables of interest included location and timing of patient presentation, timelines to vascular imaging, and same-day collaboration between key services such as emergency, neurology, and surgery. Descriptive statistics and univariate analysis were used to determine statistically significant differences between groups. RESULTS: A total of 228 records met the inclusion criteria. The median time from TIA/stroke to carotid revascularization was 10 days, with 58% of patients meeting the 14-day guideline. Prompt patient presentation to emergency demonstrated significantly shorter timelines to surgery (7 days; P < .001). Early vascular imaging was strongly correlated with early revascularization (4-5 days; P < .001). In addition, collaboration from two or more care services enhanced timelines to surgery ranging from 2.0 to 6.5 days (P < .001-.008). CONCLUSIONS: Early/emergency response to stroke symptoms was pivotal in achieving best practice recommendations for rapid carotid revascularization, emphasizing the need for ongoing public awareness. Emergency and ambulatory strategies to facilitate urgent vascular imaging, as well as mechanisms for same-day communication between teams require optimization to promote early revascularization.

Early Dabigatran Treatment After Transient Ischemic Attack and Minor Ischemic Stroke Does Not Result in Hemorrhagic Transformation.

OBJECTIVES: The optimal timing of anticoagulation after ischemic stroke in atrial fibrillation (AF) patients is unknown. Our aim was to demonstrate the feasibility and safety of initiating dabigatran therapy within 14 days of transient ischemic attack (TIA) or minor stroke in AF patients. PATIENTS AND METHODS: A prospective, multi-center registry (NCT02415855) in patients with AF treated with dabigatran within 14 days of acute ischemic stroke/TIA (National Institutes of Health Stroke Scale (NIHSS) ≤ 3) onset. Baseline and follow-up computed tomography (CT) scans were assessed for hemorrhagic transformation (HT) and graded by using European Cooperative Acute Stroke Study criteria. RESULTS: One hundred and one patients, with a mean age of 72.4 ± 11.5 years, were enrolled. Median infarct volume was 0 ml. Median time from index event onset to dabigatran initiation was 2 days, and median baseline NIHSS was 1. Pre-treatment HT was present in seven patients. No patients developed symptomatic HT. On the day 7 CT scan, HT was present in six patients (one progressing from baseline hemorrhagic infarction type 1). Infarct volume was a predictor of incident HT (odds ratio = 1.063 [1.020-1.107], p < 0.003). All six (100%) patients with new/progressive HT were functionally independent (modified Rankin Scale (mRS) = 0-2) at 30 days, which was similar to those without HT (90%, p = 0.422). Recurrent ischemic events occurred within 30 days in four patients, two of which were associated with severe disability and death (mRS 5 and 6, respectively). CONCLUSION: Early dabigatran treatment did not precipitate symptomatic HT after minor stroke. Asymptomatic HT was associated with larger baseline infarct volumes. Early recurrent ischemic events may be clinically more important.

Neuroscience Intermediate-Level Care Units Staffed by Intensivists: Clinical Outcomes and Cost Analysis.

INTRODUCTION:: With an aging population and increasing numbers of intensive care unit admissions, novel ways of providing quality care at reduced cost are required. Closed neurointensive care units improve outcomes for patients with critical neurological conditions, including decreased mortality and length of stay (LOS). Small studies have demonstrated the safety of intermediate-level units for selected patient populations. However, few studies analyze both cost and safety outcomes of these units. This retrospective study assessed clinical and cost-related outcomes in an intermediate-level neurosciences acute care unit (NACU) before and after the addition of an intensivist to the unit's care team. METHODS:: Starting in October 2011, an intensivist-led model was adopted in a 16-bed NACU unit, including daytime coverage by a dedicated intensivist. Data were obtained from all patients admitted 1 year prior to and 2 years after this intervention. Primary outcomes were LOS and hospital costs. Safety outcomes included mortality and readmissions. Descriptive and analytic statistics were calculated. Individual and total patient costs were calculated based on per-day NACU and ward cost estimates and significance measured using bootstrapping. RESULTS:: A total of 2931 patients were included over the study period. Patients were on average 59.5 years and 53% male. The most common reasons for admission were central nervous system (CNS) tumor (27.6%), ischemic stroke (27%), and subarachnoid hemorrhage (11%). Following the introduction of an intensivist, there was a significant reduction in NACU and hospital LOS, by 1 day and 3 days, respectively. There were no differences in readmissions or mortality. Adding an intensivist produced an individual cost savings of US$963 in NACU and US$2687 per patient total hospital stay. CONCLUSION:: An intensivist-led model of intermediate-level neurointensive care staffed by intensivists is safe, decreases LOS, and produces cost savings in a system increasingly strained to provide quality neurocritical care.

Early cerebral small vessel disease and brain volume, cognition, and gait.

OBJECTIVE: Decline in cognitive function begins by the 40s, and may be related to future dementia risk. We used data from a community-representative study to determine whether there are age-related differences in simple cognitive and gait tests by the 40s, and whether these differences were associated with covert cerebrovascular disease on magnetic resonance imaging (MRI). METHODS: Between 2010 and 2012, 803 participants aged 40 to 75 years in the Prospective Urban Rural Epidemiological (PURE) study, recruited from prespecified postal code regions centered on 4 Canadian cities, underwent brain MRI and simple tests of cognition and gait as part of a substudy (PURE-MIND). RESULTS: Mean age was 58 ± 8 years. Linear decreases in performance on the Montreal Cognitive Assessment, Digit Symbol Substitution Test (DSST), and Timed Up and Go test of gait were seen with each age decade from the 40s to the 70s. Silent brain infarcts were observed in 3% of 40- to 49-year-olds, with increasing prevalence up to 18.9% in 70-year-olds. Silent brain infarcts were associated with slower timed gait and lower volume of supratentorial white matter. Higher volume of supratentorial MRI white matter hyperintensity was associated with slower timed gait and worse performance on DSST, and lower volumes of the supratentorial cortex and white matter, and cerebellum. INTERPRETATION: Covert cerebrovascular disease and its consequences on cognitive and gait performance and brain atrophy are manifest in some clinically asymptomatic persons as early as the 5th decade of life.

Fast-Track Systems Improve Timely Carotid Endarterectomy in Stroke Prevention Outpatients.

BACKGROUND: For optimal stroke prevention, best practices guidelines recommend carotid endarterectomy (CEA) for symptomatic patients within two weeks; however, 2013 Ontario data indicated that only 9% of eligible patients from outpatient Stroke Prevention Clinics (SPCs) achieved this target. The goal of our study was to identify modifiable system factors that could enhance the quality and timeliness of care among patients needing urgent CEA. METHODS: We conducted a retrospective chart review of transient ischemic attack/stroke patients assessed in Champlain Local Health Integrated Network SPCs between 2011 and 2014 who subsequently underwent CEA. Descriptive statistics were used to define patient characteristics, timelines from symptom onset to CEA, and system factors that contributed to delays or improvements in care. Multivariate analysis was used to determine statistically significant variations between groups. RESULTS: Seventy-five records were eligible for study inclusion. Median time from initial symptoms to CEA was 31 days, with 21.3% of patients undergoing surgery within 2 weeks. Significant delays were common in patient presentation and assessment following symptom onset, wait times for vascular imaging and neurological assessment, and time from surgical assessment to CEA completion. Rapid testing and triage, coupled with collaborative initiatives among SPC, surgical, and radiology teams were associated with significantly improved timelines. CONCLUSIONS: Success factors for rapid CEA are multifaceted, including system changes that address public awareness of stroke and 911 response, improvements in vascular imaging access, and redesign of clinical services to promote collaboration and fast-tracking of care. Implementation of performance measures to monitor and guide clinical innovations is recommended.

Mechanical Thrombectomy in Acute Ischemic Stroke: A Systematic Review.

Although intravenous thrombolysis increases the probability of a good functional outcome in carefully selected patients with acute ischemic stroke, a substantial proportion of patients who receive thrombolysis do not have a good outcome. Several recent trials of mechanical thrombectomy appear to indicate that this treatment may be superior to thrombolysis. We therefore conducted a systematic review and meta-analysis to evaluate the clinical effectiveness and safety of new-generation mechanical thrombectomy devices with intravenous thrombolysis (if eligible) compared with intravenous thrombolysis (if eligible) in patients with acute ischemic stroke caused by a proximal intracranial occlusion. We systematically searched seven databases for randomized controlled trials published between January 2005 and March 2015 comparing stent retrievers or thromboaspiration devices with best medical therapy (with or without intravenous thrombolysis) in adults with acute ischemic stroke. We assessed risk of bias and overall quality of the included trials. We combined the data using a fixed or random effects meta-analysis, where appropriate. We identified 1579 studies; of these, we evaluated 122 full-text papers and included five randomized control trials (n=1287). Compared with patients treated medically, patients who received mechanical thrombectomy were more likely to be functionally independent as measured by a modified Rankin score of 0-2 (odds ratio, 2.39; 95% confidence interval, 1.88-3.04; I2=0%). This finding was robust to subgroup analysis. Mortality and symptomatic intracerebral hemorrhage were not significantly different between the two groups. Mechanical thrombectomy significantly improves functional independence in appropriately selected patients with acute ischemic stroke.

Time From Symptoms to Carotid Endarterectomy or Stenting and Perioperative Risk.

BACKGROUND AND PURPOSE: Prior meta-analysis showed that carotid endarterectomy benefits decline with increasing surgical delay following symptoms. For symptomatic patients in the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST), we assessed if differences in time between symptoms and carotid endarterectomy or carotid artery stenting are associated with differences in risk of periprocedural stroke or death. METHODS: We analyzed the 1180 symptomatic patients in CREST who received their assigned procedure and had clearly defined timing of symptoms. Patients were classified into 3 groups based on time from symptoms to procedure: <15, 15 to 60, and >60 days. RESULTS: For carotid endarterectomy, risk of periprocedural stroke or death was not significantly different for the 2 later time periods relative to the earliest time period (hazard ratio, 0.74; 95% confidence interval, 0.22-2.49 for 15-60 days and hazard ratio, 0.91; 95% confidence interval, 0.25-3.33 for >60 days; P=0.89). For carotid artery stenting, risk of periprocedural stroke or death was also not significantly different for later time periods relative to the earliest time period (hazard ratio, 1.12; 95% confidence interval, 0.53-2.40 for 15-60 days and hazard ratio, 1.15; 95% confidence interval, 0.48-2.75 for >60 days; P=0.93). CONCLUSIONS: Time from symptoms to carotid endarterectomy or carotid artery stenting did not alter periprocedural safety, supporting early revascularization regardless of modality. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00004732.

Computed tomography identifies patients at high risk for stroke after transient ischemic attack/nondisabling stroke: prospective, multicenter cohort study.

BACKGROUND AND PURPOSE: Ischemia on computed tomography (CT) is associated with subsequent stroke after transient ischemic attack. This study assessed CT findings of acute ischemia, chronic ischemia, or microangiopathy for predicting subsequent stroke after transient ischemic attack. METHODS: This prospective cohort study enrolled patients with transient ischemic attack or nondisabling stroke that had CT scanning within 24 hours. Primary outcome was subsequent stroke within 90 days. Secondary outcomes were stroke at ≤2 or >2 days. CT findings were classified as ischemia present or absent and acute or chronic or microangiopathy. Analysis used Fisher exact test and multivariate logistic regression. RESULTS: A total of 2028 patients were included; 814 had ischemic changes on CT. Subsequent stroke rate was 3.4% at 90 days and 1.5% at ≤2 days. Stroke risk was greater if baseline CT showed acute ischemia alone (10.6%; P=0.002), acute+chronic ischemia (17.4%; P=0.007), acute ischemia+microangiopathy (17.6%; P=0.019), or acute+chronic ischemia+microangiopathy (25.0%; P=0.029). Logistic regression found acute ischemia alone (odds ratio [OR], 2.61; 95% confidence interval [CI[, 1.22-5.57), acute+chronic ischemia (OR, 5.35; 95% CI, 1.71-16.70), acute ischemia+microangiopathy (OR, 4.90; 95% CI, 1.33-18.07), or acute+chronic ischemia+microangiopathy (OR, 8.04; 95% CI, 1.52-42.63) was associated with a greater risk at 90 days, whereas acute+chronic ischemia (OR, 10.78; 95% CI, 2.93-36.68), acute ischemia+microangiopathy (OR, 8.90; 95% CI, 1.90-41.60), and acute+chronic ischemia+microangiopathy (OR, 23.66; 95% CI, 4.34-129.03) had greater risk at ≤2 days. Only acute ischemia (OR, 2.70; 95% CI, 1.01-7.18; P=0.047) was associated with a greater risk at >2 days. CONCLUSIONS: In patients with transient ischemic attack/nondisabling stroke, CT evidence of acute ischemia alone or acute ischemia with chronic ischemia or microangiopathy was associated with increased subsequent stroke risk within 90 days.

Beating the clock: time delays to thrombolytic therapy with advanced imaging and impact of optimized workflow.

BACKGROUND: The effectiveness of intravenous tissue plasminogen activator in the management of acute ischemic strokes diminishes significantly with time. Advanced computed tomography (CT) imaging can be helpful to identify candidates for neurointerventional procedures. We have successfully used a 320-slice Toshiba volume CT scanner since mid-2008. Other centers have forgone advanced imaging because of concerns of time delay. This study is to assess the time delay while using this scanner compared with our 64-slice scanner. METHODS: Treatment times of patients scanned with advanced imaging (CT head, dynamic CT angiography, and whole brain perfusion-group A) and patients scanned in a 64-slice scanner (CT head and traditional CT angiogram-group B) were compared. Two groups of stroke patients from November-March 2009-2010 (group 1) and 2012-2013 (group 2) were audited to assess temporal improvement. Multiple timing variables were analyzed. RESULTS: One hundred fifty-three cases from 2009/10 and 192 cases from 2012/13 were analyzed. The median door-to-needle time (DNT) for group 1A and group 2A was 57 minutes and 47 minutes, respectively. The median DNT for group 1B and group 2B was 54 minutes and 49 minutes, respectively. Decrease in the overall DNT with group A can be attributed to the "streamlining" of the stroke code process. There was no difference in the DNT for patients who presented during working hours versus those who presented during nonworking hours. CONCLUSIONS: With adequate experience and training, advanced stroke imaging with whole brain perfusion/dynamic CT angiography can be performed with treatment times that are comparable with traditional CT scanning.

Evolution of computed tomography angiography spot sign is consistent with a site of active hemorrhage in acute intracerebral hemorrhage.

BACKGROUND AND PURPOSE: CT angiography spot sign predicts hematoma expansion in patients with acute intracerebral hemorrhage (ICH). The spot sign may represent a site of active extravasation, a locus of arrested hemorrhage forming fibrin globes, or represent associated epiphenomena such as hypertensive microaneurysms. We sought to describe the evolution of spot signs over 60 seconds in acute ICH using dynamic CT angiography and determine whether they grow and diffuse into the hematoma as would be expected with active extravasation. METHODS: We prospectively identified consecutive patients presenting with spontaneous ICH<6 hours from symptom onset that completed dynamic CT angiography imaging over a 60-second acquisition protocol. We determined spot positivity, quantified spot volumes, and then used repeated-measures ANOVA to assess changes in spot volume over time. RESULTS: We collected data on 35 patients; 13 of 35 (37%) patients were spot-positive. Spot-positive patients had larger median ICH volume compared with spot-negative patients (median 10.7 versus 49.2 mL; P=0.007). Maximal spot sign volumes ranged from 0.02 to 2.8 mL (median 0.17 mL). Spot sign volumes increased significantly with time (P<0.001) and seemed to disperse into the hematoma in all cases. Three of 13 (23%) spot-positive patients presented with 2 distinct spot signs, but the remaining patients either had only 1 spot sign or different contiguous components of an irregularly shaped spot sign. CONCLUSIONS: In this dynamic CT angiography study of ICH, spot signs evolve consistent with sites of active extravasation.

A prospective cohort study of patients with transient ischemic attack to identify high-risk clinical characteristics.

BACKGROUND AND PURPOSE: The occurrence of a transient ischemic attack (TIA) increases an individual's risk for subsequent stroke. The objectives of this study were to determine clinical features of patients with TIA associated with impending (≤7 days) stroke and to develop a clinical prediction score for impending stroke. METHODS: We conducted a prospective cohort study at 8 Canadian emergency departments for 5 years. We enrolled patients with a new TIA. Our outcome was subsequent stroke within 7 days of TIA diagnosis. RESULTS: We prospectively enrolled 3906 patients, of which 86 (2.2%) experienced a stroke within 7 days. Clinical features strongly correlated with having an impending stroke included first-ever TIA, language disturbance, longer duration, weakness, gait disturbance, elevated blood pressure, atrial fibrillation on ECG, infarction on computed tomography, and elevated blood glucose. Variables less associated with having an impending stroke included vertigo, lightheadedness, and visual loss. From this cohort, we derived the Canadian TIA Score which identifies the risk of subsequent stroke≤7 days and consists of 13 variables. This model has good discrimination with a c-statistic of 0.77 (95% confidence interval, 0.73-0.82). CONCLUSIONS: Patients with TIA with their first TIA, language disturbance, duration of symptoms≥10 minutes, gait disturbance, atrial fibrillation, infarction on computed tomography, elevated platelets or glucose, unilateral weakness, history of carotid stenosis, and elevated diastolic blood pressure are at higher risk for an impending stroke. Patients with vertigo and no high-risk features are at low risk. The Canadian TIA Score quantifies the impending stroke risk following TIA.

Incidental magnetic resonance diffusion-weighted imaging-positive lesions are rare in neurologically asymptomatic community-dwelling adults.

BACKGROUND AND PURPOSE: Incidental magnetic resonance diffusion-weighted imaging (DWI)-positive lesions, considered to represent small acute infarcts, have been detected in patients with cerebral small vessel diseases or cognitive impairment, but the prevalence in the community population is unknown. METHODS: DWI sequences collected in 793 participants in the Prospective Urban Rural Epidemiological (PURE) study were reviewed for DWI lesions consistent with small acute infarcts. RESULTS: No DWI-positive lesions were detected (0%, 95% confidence interval, 0-0.5). CONCLUSIONS: DWI-positive lesions are rare in an asymptomatic community population. The prevalence of DWI-positive lesions in the community seems to be lower than in patients with cerebral amyloid angiopathy, intracerebral hemorrhage, or cognitive impairment.

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.

Safety of acute internal carotid artery stenting during endovascular thrombectomy in patients with acute ischemic stroke: a retrospective analysis of the OPTIMISE registry.

BACKGROUND: The optimal management of tandem carotid lesions during endovascular thrombectomy (EVT) remains uncertain. The safety and efficacy of acute carotid artery stenting (aCAS) are debated, including safety concerns such as procedural complications and symptomatic intracerebral hemorrhage (sICH). We aimed to assess aCAS safety among EVT-treated patients using a large Canadian registry. METHODS: We retrospectively analyzed the OPTIMISE registry and compared adult patients undergoing EVT and aCAS versus EVT only. The primary outcome was a composite of in-hospital death, long-term care facility destination at discharge, sICH, or any EVT-related procedural complications. Secondary outcomes included individual components of the primary outcome, EVT workflow times, final modified Thrombolysis in Cerebral Ischemia score and 90-day modified Rankin Scale score. Statistical significance was evaluated by a multivariate logistic regression model. RESULTS: 4205 patients were included (330 with EVT-aCAS and 3875 with EVT-only). Both groups were similar with regard to baseline National Institutes of Health Stroke Scale score, Alberta Stroke Program Early CT Score and use of IV thrombolysis, but differed in age (EVT-aCAS group 67.2±12.1 years vs EVT-only group 71.3±14.1 years, P<0.001), proportion of women (28.2% vs 53.3%, P<0.001), and occlusion location (internal carotid artery terminus 44% vs 16%, P<0.001). The EVT-aCAS group showed a non-significant increase in odds of composite safety outcomes (adjusted OR 1.35 (95% CI 0.97 to 1.84), P=0.06) with a significantly higher proportion of procedural complications (10.0% vs 6.2%, P=0.002). CONCLUSION: In a large national registry, EVT-aCAS was associated with a higher proportion of unfavorable safety outcomes, driven by more frequent procedural complications. Further research is needed to clarify the role of aCAS in tandem occlusion stroke.