Learning together for better health using an evidence-based Learning Health System framework: a case study in stroke.

BACKGROUND: In the context of expanding digital health tools, the health system is ready for Learning Health System (LHS) models. These models, with proper governance and stakeholder engagement, enable the integration of digital infrastructure to provide feedback to all relevant parties including clinicians and consumers on performance against best practice standards, as well as fostering innovation and aligning healthcare with patient needs. The LHS literature primarily includes opinion or consensus-based frameworks and lacks validation or evidence of benefit. Our aim was to outline a rigorously codesigned, evidence-based LHS framework and present a national case study of an LHS-aligned national stroke program that has delivered clinical benefit. MAIN TEXT: Current core components of a LHS involve capturing evidence from communities and stakeholders (quadrant 1), integrating evidence from research findings (quadrant 2), leveraging evidence from data and practice (quadrant 3), and generating evidence from implementation (quadrant 4) for iterative system-level improvement. The Australian Stroke program was selected as the case study as it provides an exemplar of how an iterative LHS works in practice at a national level encompassing and integrating evidence from all four LHS quadrants. Using this case study, we demonstrate how to apply evidence-based processes to healthcare improvement and embed real-world research for optimising healthcare improvement. We emphasize the transition from research as an endpoint, to research as an enabler and a solution for impact in healthcare improvement. CONCLUSIONS: The Australian Stroke program has nationally improved stroke care since 2007, showcasing the value of integrated LHS-aligned approaches for tangible impact on outcomes. This LHS case study is a practical example for other health conditions and settings to follow suit.

Role of cardiac computed tomography in hyperacute stroke assessment.

BACKGROUND: Incorporating cardiac CT with hyperacute stroke imaging may increase the yield for cardioembolic sources. It is not clarified whether stroke severity influences on rates of intracardiac thrombus. We aimed to investigate a National Institutes of Health Stroke Scale (NIHSS) threshold below which acute cardiac CT was unnecessary. METHODS: Consecutive patients with suspected stroke who underwent multimodal brain imaging and concurrent non-gated cardiac CT with delayed timing were prospectively recruited from 1st December 2020 to 30th November 2021. We performed receiver operating characteristics analysis of the NIHSS and intracardiac thrombus on hyperacute cardiac CT. RESULTS: A total of 314 patients were assessed (median age 69 years, 61% male). Final diagnoses were ischemic stroke (n=205; 132 etiology-confirmed stroke, independent of cardiac CT and 73 cryptogenic), transient ischemic attack (TIA) (n=21) and stroke-mimic syndromes (n=88). The total yield of cardiac CT was 8 intracardiac thrombus and 1 dissection. Cardiac CT identified an intracardiac thrombus in 6 (4.5%) with etiology-confirmed stroke, 2 (2.7%) with cryptogenic stroke, and none in patients with TIA or stroke-mimic. All of those with intracardiac thrombus had NIHSS ≥4 and this was the threshold below which hyperacute cardiac CT was not justified (sensitivity 100%, specificity 38%, positive predictive value 4.0%, negative predictive value 100%). CONCLUSIONS: A cutoff NIHSS ≥4 may be useful to stratify patients for cardiac CT in the hyperacute stroke setting to optimize its diagnostic yield and reduce additional radiation exposure.

Management of Poststroke Hyperglycemia: Results of the TEXAIS Randomized Clinical Trial.

BACKGROUND: Hyperglycemia in acute ischemic stroke reduces the efficacy of stroke thrombolysis and thrombectomy, with worse clinical outcomes. Insulin-based therapies are difficult to implement and may cause hypoglycemia. We investigated whether exenatide, a GLP-1 (glucagon-like peptide-1) receptor agonist, would improve stroke outcomes, and control poststroke hyperglycemia with minimal hypoglycemia. METHODS: The TEXAIS trial (Treatment With Exenatide in Acute Ischemic Stroke) was an international, multicenter, phase 2 prospective randomized clinical trial (PROBE [Prospective Randomized Open Blinded End-Point] design) enrolling adult patients with acute ischemic stroke ≤9 hours of stroke onset to receive exenatide (5 µg BID subcutaneous injection) or standard care for 5 days, or until hospital discharge (whichever sooner). The primary outcome (intention to treat) was the proportion of patients with ≥8-point improvement in National Institutes of Health Stroke Scale score (or National Institutes of Health Stroke Scale scores 0-1) at 7 days poststroke. Safety outcomes included death, episodes of hyperglycemia, hypoglycemia, and adverse event. RESULTS: From April 2016 to June 2021, 350 patients were randomized (exenatide, n=177, standard care, n=173). Median age, 71 years (interquartile range, 62-79), median National Institutes of Health Stroke Scale score, 4 (interquartile range, 2-8). Planned recruitment (n=528) was stopped early due to COVID-19 disruptions and funding constraints. The primary outcome was achieved in 97 of 171 (56.7%) in the standard care group versus 104 of 170 (61.2%) in the exenatide group (adjusted odds ratio, 1.22 [95% CI, 0.79-1.88]; P=0.38). No differences in secondary outcomes were observed. The per-patient mean daily frequency of hyperglycemia was significantly less in the exenatide group across all quartiles. No episodes of hypoglycemia were recorded over the treatment period. Adverse events of mild nausea and vomiting occurred in 6 (3.5%) exenatide patients versus 0 (0%) standard care with no withdrawal. CONCLUSIONS: Treatment with exenatide did not reduce neurological impairment at 7 days in patients with acute ischemic stroke. Exenatide did significantly reduce the frequency of hyperglycemic events, without hypoglycemia, and was safe to use. Larger acute stroke trials using GLP-1 agonists such as exenatide should be considered. REGISTRATION: URL: www.australianclinicaltrials.gov.au; Unique identifier: ACTRN12617000409370. URL: https://www.clinicaltrials.gov; Unique identifier: NCT03287076.

Ultra-Long Transfers for Endovascular Thrombectomy-Mission Impossible?: The Australia-New Zealand Experience.

BACKGROUND: Endovascular thrombectomy (EVT) access in remote areas is limited. Preliminary data suggest that long distance transfers for EVT may be beneficial; however, the magnitude and best imaging strategy at the referring center remains uncertain. We hypothesized that patients transferred >300 miles would benefit from EVT, achieving rates of functional independence (modified Rankin Scale [mRS] score of 0-2) at 3 months similar to those patients treated at the comprehensive stroke center in the randomized EVT extended window trials and that the selection of patients with computed tomography perfusion (CTP) at the referring site would be associated with ordinal shift toward better outcomes on the mRS. METHODS: This is a retrospective analysis of patients transferred from 31 referring hospitals >300 miles (measured by the most direct road distance) to 9 comprehensive stroke centers in Australia and New Zealand for EVT consideration (April 2016 through May 2021). RESULTS: There were 131 patients; the median age was 64 [53-74] years and the median baseline National Institutes of Health Stroke Scale score was 16 [12-22]. At baseline, 79 patients (60.3%) had noncontrast CT+CT angiography, 52 (39.7%) also had CTP. At the comprehensive stroke center, 114 (87%) patients underwent cerebral angiography, and 96 (73.3%) proceeded to EVT. At 3 months, 62 patients (48.4%) had an mRS score of 0 to 2 and 81 (63.3%) mRS score of 0 to 3. CTP selection at the referring site was not associated with better ordinal scores on the mRS at 3 months (mRS median of 2 [1-3] versus 3 [1-6] in the patients selected with noncontrast CT+CT angiography, P=0.1). Nevertheless, patients selected with CTP were less likely to have an mRS score of 5 to 6 (odds ratio 0.03 [0.01-0.19]; P<0.01). CONCLUSIONS: In selected patients transferred >300 miles, there was a benefit for EVT, with outcomes similar to those treated in the comprehensive stroke center in the EVT extended window trials. Remote hospital CTP selection was not associated with ordinal mRS improvement, but was associated with fewer very poor 3-month outcomes.

The relevance of rich club regions for functional outcome post-stroke is enhanced in women.

This study aimed to investigate the influence of stroke lesions in predefined highly interconnected (rich-club) brain regions on functional outcome post-stroke, determine their spatial specificity and explore the effects of biological sex on their relevance. We analyzed MRI data recorded at index stroke and ~3-months modified Rankin Scale (mRS) data from patients with acute ischemic stroke enrolled in the multisite MRI-GENIE study. Spatially normalized structural stroke lesions were parcellated into 108 atlas-defined bilateral (sub)cortical brain regions. Unfavorable outcome (mRS > 2) was modeled in a Bayesian logistic regression framework. Effects of individual brain regions were captured as two compound effects for (i) six bilateral rich club and (ii) all further non-rich club regions. In spatial specificity analyses, we randomized the split into "rich club" and "non-rich club" regions and compared the effect of the actual rich club regions to the distribution of effects from 1000 combinations of six random regions. In sex-specific analyses, we introduced an additional hierarchical level in our model structure to compare male and female-specific rich club effects. A total of 822 patients (age: 64.7[15.0], 39% women) were analyzed. Rich club regions had substantial relevance in explaining unfavorable functional outcome (mean of posterior distribution: 0.08, area under the curve: 0.8). In particular, the rich club-combination had a higher relevance than 98.4% of random constellations. Rich club regions were substantially more important in explaining long-term outcome in women than in men. All in all, lesions in rich club regions were associated with increased odds of unfavorable outcome. These effects were spatially specific and more pronounced in women.

Endovascular Thrombectomy Versus Medical Management in Isolated M2 Occlusions: Pooled Patient-Level Analysis from the EXTEND-IA Trials, INSPIRE, and SELECT Studies.

OBJECTIVE: The objective of this study was to evaluate functional and safety outcomes of endovascular thrombectomy (EVT) versus medical management (MM) in patients with M2 occlusion and examine their association with perfusion imaging mismatch and stroke severity. METHODS: In a pooled, patient-level analysis of 3 randomized controlled trials (EXTEND-IA, EXTEND-and IA-TNK parts 1 and 2) and 2 prospective nonrandomized studies (INSPIRE and SELECT), we evaluated EVT association with 90-day functional independence (modified Rankin Scale [mRS] = 0-2) in isolated M2 occlusions as compared to medical management overall and in subgroups by mismatch profile status and stroke severity. RESULTS: We included 517 patients (EVT = 195 and MM = 322), baseline median (interquartile range [IQR]) National Institutes of Health Stroke Scale (NIHSS) was 13 (8-19) in EVT versus 10 (6-15) in MM, p < 0.001. Pretreatment ischemic core did not differ (EVT = 10 [0-24] ml vs MM = 9 [3-21] ml, p = 0.59). Compared to MM, EVT was more frequently associated with functional independence (68.3 vs 61.6%, adjusted odds ratio [aOR] = 2.42, 95% confidence interval [CI] = 1.25-4.67, p = 0.008, inverse probability of treatment weights [IPTW]-OR = 1.75, 95% CI = 1.00-3.75, p = 0.05) with a shift toward better mRS outcomes (adjusted cOR = 2.02, 95% CI:1.23-3.29, p = 0.005), and lower mortality (5 vs 10%, aOR = 0.32, 95% CI = 0.12-0.87, p = 0.025). EVT was associated with higher functional independence in patients with a perfusion mismatch profile (EVT = 70.7% vs MM = 61.3%, aOR = 2.29, 95% CI = 1.09-4.79, p = 0.029, IPTW-OR = 2.02, 1.08-3.78, p = 0.029), whereas no difference was found in those without mismatch (EVT = 43.8% vs MM = 62.7%, p = 0.17, IPTW-OR: 0.71, 95% CI = 0.18-2.78, p = 0.62). Functional independence was more frequent with EVT in patients with moderate or severe strokes, as defined by baseline NIHSS above any thresholds from 6 to 10, whereas there was no difference between groups with milder strokes below these thresholds. INTERPRETATION: In patients with M2 occlusion, EVT was associated with improved clinical outcomes when compared to MM. This association was primarily observed in patients with a mismatch profile and those with higher stroke severity. ANN NEUROL 2022;91:629-639.

Modelling the Long-Term Health Outcome and Costs of Thrombectomy in Treating Stroke Patients with Large Ischaemic Core: Comparison between Clinical Trials and Real-World Data.

INTRODUCTION: We aimed to assess the long-term health outcomes and costs of endovascular thrombectomy (EVT) using clinical trials and real-world evidence in patients with large ischaemic core. METHODS: Both clinical trials and the INternational Stroke Perfusion Imaging REgistry (INSPIRE) were used. Patients with acute computed tomography perfusion scan with an ischaemic core of ≥70 mL were included. A Markov model was constructed to simulate the long-term costs and health outcomes (quality-adjusted life year) post-index stroke. Effectiveness of EVT (modified Rankin scale score at 3 months) was derived from the trials and INSPIRE registry (compared to matched patients not treated with EVT), respectively. RESULTS: Based on the trial and real-world data, the overall results revealed varied health benefits and costs due to EVT, with reduced health benefits and increased costs from EVT treatment in everyday practice. The long-term simulation estimated that offering EVT to large vessel occlusion stroke patients with large ischaemic core was associated with greater benefits (1.12 vs. 0.25 quality-adjusted life year gains) and lower (-A$19,320) or higher costs (A$11,278), using trial and real-world data, respectively. The incremental cost of the EVT procedure (i.e., A$14,356) could be primarily offset to a different extent by the reduction in costs related to the nursing home care (-$31,986 vs. -A$1,874) in the clinical trial and real-world practice. CONCLUSIONS: Our results highlight the potential gaps when implementing an effective intervention in the real world and the importance of the rigorous selection of large infarct core patients for EVT.

Rural versus metropolitan comparison of processes of care in the community-based management of TIA and minor stroke in Australia (an analysis from the INSIST study).

OBJECTIVES: To compare processes of care and clinical outcomes of community-based management of TIAs and minor strokes (TIAMS) between rural and metropolitan Australia. DESIGN: Inception cohort study between 2012 and 2016 with 12-month follow-up after index event (sub-study of INSIST). SETTING: Hunter and Manning valley regions of New South Wales, within the referral territory of the John Hunter Hospital Acute Neurovascular Clinic (JHHANC). PARTICIPANTS: Consecutive patients of 16 participating general practices, presenting with possible TIAMS to either primary or secondary care. MAIN OUTCOME MEASURES: Processes of care (referrals, key management processes, time-based metrics) and clinical outcomes. RESULTS: Of 613 participants with possible TIAMS who completed the baseline interview, 298 were adjudicated as having TIAMS (119 from rural, 179 from metropolitan). Mean age was 72.3 years (SD, 10.7) and 127 (43%) were women. Rural participants were more likely to be managed solely by a general practitioner (GP) than metropolitan participants (34% v 20%) and less likely to be referred to a JHHANC specialist (13% v 38%) or have brain magnetic resonance imaging (MRI) [24% v 51%]. Those rural participants who were referred, also waited longer (both p < 0.001). Recurrent stroke, myocardial infarction and death at 12 months were not significantly different between rural and metropolitan participants. CONCLUSIONS: Although TIAMS prognosis in rural settings where solely GP care is common is very good, the processes of care in such areas are inferior to metropolitan. This suggests there is further scope to support rural GPs to optimise care of TIAMS patients.

Associations of Early Systolic Blood Pressure Control and Outcome After Thrombolysis-Eligible Acute Ischemic Stroke: Results From the ENCHANTED Study.

BACKGROUND AND PURPOSE: In thrombolysis-eligible patients with acute ischemic stroke, there is uncertainty over the most appropriate systolic blood pressure (SBP) lowering profile that provides an optimal balance of potential benefit (functional recovery) and harm (intracranial hemorrhage). We aimed to determine relationships of SBP parameters and outcomes in thrombolyzed acute ischemic stroke patients. METHODS: Post hoc analyzes of the ENCHANTED (Enhanced Control of Hypertension and Thrombolysis Stroke Study), a partial-factorial trial of thrombolysis-eligible and treated acute ischemic stroke patients with high SBP (150-180 mm Hg) assigned to low-dose (0.6 mg/kg) or standard-dose (0.9 mg/kg) alteplase and intensive (target SBP, 130-140 mm Hg) or guideline-recommended (target SBP <180 mm Hg) treatment. All patients were followed up for functional status and serious adverse events to 90 days. Logistic regression models were used to analyze 3 SBP summary measures postrandomization: attained (mean), variability (SD) in 1-24 hours, and magnitude of reduction in 1 hour. The primary outcome was a favorable shift on the modified Rankin Scale. The key safety outcome was any intracranial hemorrhage. RESULTS: Among 4511 included participants (mean age 67 years, 38% female, 65% Asian) lower attained SBP and smaller SBP variability were associated with favorable shift on the modified Rankin Scale (per 10 mm Hg increase: odds ratio, 0.76 [95% CI, 0.71-0.82]; P<0.001 and 0.86 [95% CI, 0.76-0.98]; P=0.025) respectively, but not for magnitude of SBP reduction (0.98, [0.93-1.04]; P=0.564). Odds of intracranial hemorrhage was associated with higher attained SBP and greater SBP variability (1.18 [1.06-1.31]; P=0.002 and 1.34 [1.11-1.62]; P=0.002) but not with magnitude of SBP reduction (1.05 [0.98-1.14]; P=0.184). CONCLUSIONS: Attaining early and consistent low levels in SBP <140 mm Hg, even as low as 110 to 120 mm Hg, over 24 hours is associated with better outcomes in thrombolyzed acute ischemic stroke patients. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01422616.

Thrombolysis Guided by Perfusion Imaging up to 9 Hours after Onset of Stroke.

BACKGROUND: The time to initiate intravenous thrombolysis for acute ischemic stroke is generally limited to within 4.5 hours after the onset of symptoms. Some trials have suggested that the treatment window may be extended in patients who are shown to have ischemic but not yet infarcted brain tissue on imaging. METHODS: We conducted a multicenter, randomized, placebo-controlled trial involving patients with ischemic stroke who had hypoperfused but salvageable regions of brain detected on automated perfusion imaging. The patients were randomly assigned to receive intravenous alteplase or placebo between 4.5 and 9.0 hours after the onset of stroke or on awakening with stroke (if within 9 hours from the midpoint of sleep). The primary outcome was a score of 0 or 1 on the modified Rankin scale, on which scores range from 0 (no symptoms) to 6 (death), at 90 days. The risk ratio for the primary outcome was adjusted for age and clinical severity at baseline. RESULTS: After 225 of the planned 310 patients had been enrolled, the trial was terminated because of a loss of equipoise after the publication of positive results from a previous trial. A total of 113 patients were randomly assigned to the alteplase group and 112 to the placebo group. The primary outcome occurred in 40 patients (35.4%) in the alteplase group and in 33 patients (29.5%) in the placebo group (adjusted risk ratio, 1.44; 95% confidence interval [CI], 1.01 to 2.06; P = 0.04). Symptomatic intracerebral hemorrhage occurred in 7 patients (6.2%) in the alteplase group and in 1 patient (0.9%) in the placebo group (adjusted risk ratio, 7.22; 95% CI, 0.97 to 53.5; P = 0.05). A secondary ordinal analysis of the distribution of scores on the modified Rankin scale did not show a significant between-group difference in functional improvement at 90 days. CONCLUSIONS: Among the patients in this trial who had ischemic stroke and salvageable brain tissue, the use of alteplase between 4.5 and 9.0 hours after stroke onset or at the time the patient awoke with stroke symptoms resulted in a higher percentage of patients with no or minor neurologic deficits than the use of placebo. There were more cases of symptomatic cerebral hemorrhage in the alteplase group than in the placebo group. (Funded by the Australian National Health and Medical Research Council and others; EXTEND ClinicalTrials.gov numbers, NCT00887328 and NCT01580839.).

Whole blood viscosity is associated with baseline cerebral perfusion in acute ischemic stroke.

Whole blood viscosity (WBV) is the intrinsic resistance to flow developed due to the frictional force between adjacent layers of flowing blood. Elevated WBV is an independent risk factor for stroke. Poor microcirculation due to elevated WBV can prevent adequate perfusion of the brain and might act as an important secondary factor for hypoperfusion in acute ischaemic stroke. In the present study, we examined the association of WBV with basal cerebral perfusion assessed by CT perfusion in acute ischaemic stroke. Confirmed acute ischemic stroke patients (n = 82) presenting in hours were recruited from the single centre. Patients underwent baseline multimodal CT (non-contrast CT, CT angiography and CT perfusion). Where clinically warranted, patients also underwent follow-up DWI. WBV was measured in duplicate within 2 h after sampling from 5-mL EDTA blood sample. WBV was significantly correlated with CT perfusion parameters such as perfusion lesion volume, ischemic core volume and mismatch ratio; DWI volume and baseline NIHSS. In a multivariate linear regression model, WBV significantly predicted acute perfusion lesion volume, core volume and mismatch ratio after adjusting for the effect of occlusion site and collateral status. Association of WBV with hypoperfusion (increased perfusion lesion volume, ischaemic core volume and mismatch ratio) suggest the role of erythrocyte rheology in cerebral haemodynamic of acute ischemic stroke. The present findings open new possibilities for therapeutic strategies targeting erythrocyte rheology to improve cerebral microcirculation in stroke.

Transition in Incidence Rate of Hospitalised Stroke and Case Fatality Rate in the Hunter Region, Australia, 2001-2019: A Prospective Hospital-Based Study.

INTRODUCTION: Continuous surveillance of stroke admissions has been conducted in the Hunter region, Australia, over the past two decades. We aimed to describe the trends in incidence rates of hospitalised stroke and case-fatality rates in this region, 2001-2019. METHODS: From a hospital-based stroke registry, data for admitted adult stroke patients residing in the Hunter region were collected using ICD-10 codes for ischemic and haemorrhagic stroke. Negative binomial regression and logistic regression analysis were used to analyse trends for age-standardised and age-specific incidence rates of hospitalised stroke and 28-day case-fatality rates. RESULTS: A total of 14,662 hospitalisations for stroke in 13,242 individuals were registered. The age-standardised incidence rate declined from 123 per 100,000 population in the 2001-2005 epoch to 96 in the 2016-2019 epoch (mean annual change -2.0%, incidence rate ratio (IRR) = 0.980 [95%CI: 0.976-0.984]). Age-specific analyses identified significant reduction in the group aged 75-84 (1039 per 100,000 population in 2001-2005 to 633 in 2016-2019, annual change -3.5%, IRR= 0.965 [95%CI: 0.960-0.970]). The 28-day case-fatality rates fluctuated over time (18.5% in 2001-2005, 20.8% in 2010-2015, and 17.8% in 2016-2019).  Projected population aging suggests annual volume of patients with new stroke will increase by 77% by 2041 if incidence rates remain unchanged at the 2016-2019 level. CONCLUSION: Although age-standardised hospitalised stroke incidence rates have declined in the Hunter region, the health system will face an increase in stroke hospitalisations related to the aging population.

The Hospitalization Rate of Cerebral Venous Sinus Thrombosis before and during COVID-19 Pandemic Era: A Single-Center Retrospective Cohort Study.

OBJECTIVES: There are several reports of the association between SARS-CoV-2 infection (COVID-19) and cerebral venous sinus thrombosis (CVST). In this study, we aimed to compare the hospitalization rate of CVST before and during the COVID-19 pandemic (before vaccination program). MATERIALS AND METHODS: In this retrospective cohort study, the hospitalization rate of adult CVST patients in Namazi hospital, a tertiary referral center in the south of Iran, was compared in two periods of time. We defined March 2018 to March 2019 as the pre-COVID-19 period and March 2020 to March 2021 as the COVID-19 period. RESULTS: 50 and 77 adult CVST patients were hospitalized in the pre-COVID-19 and COVID-19 periods, respectively. The crude CVST hospitalization rate increased from 14.33 in the pre-COVID-19 period to 21.7 per million in the COVID-19 era (P = 0.021). However, after age and sex adjustment, the incremental trend in hospitalization rate was not significant (95% CrI: -2.2, 5.14). Patients > 50-year-old were more often hospitalized in the COVID-19 period (P = 0.042). SARS-CoV-2 PCR test was done in 49.3% out of all COVID-19 period patients, which were positive in 6.5%. Modified Rankin Scale (mRS) score ≥3 at three-month follow-up was associated with age (P = 0.015) and malignancy (P = 0.014) in pre-COVID period; and was associated with age (P = 0.025), altered mental status on admission time (P<0.001), malignancy (P = 0.041) and COVID-19 infection (P = 0.008) in COVID-19 period. CONCLUSION: Since there was a more dismal outcome in COVID-19 associated CVST, a high index of suspicion for CVST among COVID-19 positive is recommended.

Impact of an outpatient telestroke clinic on management of rural stroke patients.

OBJECTIVE: Report on feasibility, use and effects on investigations and treatment of a neurologist-supported stroke clinic in rural Australia. DESIGN: Data were collected prospectively for consecutive patients referred to atelehealth stroke clinic from November 2018 to August 2021. SETTINGS, PARTICIPANTS AND INTERVENTIONS: Patients attended the local hospital, with a rural stroke care coordinator, and were assessed by stroke neurologist over videoconference. MAIN OUTCOME MEASURES: The following feasibility outcomes on the first appointments were analysed: (1) utility (a) change in medication, (b) request of additional investigations, (c) enrolment/offering clinical trials or d) other; (2) acceptability (attendance rate); and (3) process of care (waiting time to first appointment, distance travelled). RESULTS: During the study period, 173 appointments were made; 125 (73.5%) were first appointments. The median age was 70 [63-79] years, and 69 patients were male. A diagnosis of stroke or transient ischemic attack was made by the neurologist in 106 patients. A change in diagnosis was made in 23 (18.4%) patients. Of the first appointments, 102 (81.6%) resulted in at least one intervention: medication was changed in 67 (53.6%) patients, additional investigations requested in 72 (57.6%), 15 patients (12%) were referred to a clinical trial, and other interventions were made in 23 patients. The overall attendance rate of booked appointments was high. The median waiting time and distance travelled (round-trip) for a first appointment were 38 [24-53] days and 60.8 [25.6-76.6] km respectively. CONCLUSION: The telestroke clinic was very well attended, and it led to high volume of interventions in rural stroke patients.

Role of Computed Tomography Perfusion in Identification of Acute Lacunar Stroke Syndromes.

BACKGROUND AND PURPOSE: Lacunar syndromes correlate with a lacunar stroke on imaging in 50% to 60% of cases. Computed tomography perfusion (CTP) is becoming the preferred imaging modality for acute stroke triage. We aimed to estimate the sensitivity, specificity, and predictive values for noncontrast computed tomography and CTP in lacunar syndromes, and for cortical, subcortical, and posterior fossa regions. METHODS: A retrospective analysis of confirmed ischemic stroke patients who underwent acute CTP and follow-up magnetic resonance imaging between 2010 and 2018 was performed. Brain noncontrast computed tomography and CTP were assessed independently by 2 stroke neurologists. Receiver operating characteristic curve analysis was performed to estimate sensitivity, specificity, and area under the curve (AUC) for the detection of strokes in patients with lacunar syndromes using different CTP maps. RESULTS: We found 106 clinical lacunar syndromes, but on diffusion-weighted imaging, these consisted of 59 lacunar, 33 cortical, and 14 posterior fossa strokes. The discrimination of ischemia identification was very poor using noncontrast computed tomography in all 3 regions, but good for cortical (AUC, 0.82) and poor for subcortical and posterior regions (AUCs, 0.55 and 0.66) using automated core-penumbra maps. The addition of delay time and mean transient time maps substantially increased subcortical (AUC, 0.80) and slightly posterior stroke detection (AUC, 0.69). CONCLUSIONS: Analysis of mean transient time and delay time maps in combination with core-penumbra maps improves detection of subcortical and posterior strokes.

Stroke Patients With Faster Core Growth Have Greater Benefit From Endovascular Therapy.

BACKGROUND AND PURPOSE: This study aimed to explore whether the therapeutic benefit of endovascular thrombectomy (EVT) was mediated by core growth rate. METHODS: This retrospective cohort study identified acute ischemic stroke patients with large vessel occlusion and receiving reperfusion treatment, either EVT or intravenous thrombolysis (IVT), within 4.5 hours of stroke onset. Patients were divided into 2 groups: EVT versus IVT only patients (who had no access to EVT). Core growth rate was estimated by the acute core volume on perfusion computed tomography divided by the time from stroke onset to perfusion computed tomography. The primary clinical outcome was good outcome defined by 3-month modified Rankin Scale score of 0-2. Tissue outcome was the final infarction volume. RESULTS: A total of 806 patients were included, 429 in the EVT group (recanalization rate of 61.6%) and 377 in the IVT only group (recanalization rate of 44.7%). The treatment effect of EVT versus IVT only was mediated by core growth rate, showing a significant interaction between EVT treatment and core growth rate in predicting good clinical outcome (interaction odds ratio=1.03 [1.01-1.05], P=0.007) and final infarct volume (interaction odds ratio=-0.44 [-0.87 to -0.01], P=0.047). For patients with fast core growth of >25 mL/h, EVT treatment (compared with IVT only) increased the odds of good clinical outcome (adjusted odds ratio=3.62 [1.21-10.76], P=0.021) and resulted in smaller final infarction volume (37.5 versus 73.9 mL, P=0.012). For patients with slow core growth of <15 mL/h, there were no significant differences between the EVT and the IVT only group in either good clinical outcome (adjusted odds ratio=1.44 [0.97-2.14], P=0.070) or final infarction volume (22.6 versus 21.9 mL, P=0.551). CONCLUSIONS: Fast core growth was associated with greater benefit from EVT compared with IVT in the early <4.5-hour time window.

Intravenous alteplase for stroke with unknown time of onset guided by advanced imaging: systematic review and meta-analysis of individual patient data.

BACKGROUND: Patients who have had a stroke with unknown time of onset have been previously excluded from thrombolysis. We aimed to establish whether intravenous alteplase is safe and effective in such patients when salvageable tissue has been identified with imaging biomarkers. METHODS: We did a systematic review and meta-analysis of individual patient data for trials published before Sept 21, 2020. Randomised trials of intravenous alteplase versus standard of care or placebo in adults with stroke with unknown time of onset with perfusion-diffusion MRI, perfusion CT, or MRI with diffusion weighted imaging-fluid attenuated inversion recovery (DWI-FLAIR) mismatch were eligible. The primary outcome was favourable functional outcome (score of 0-1 on the modified Rankin Scale [mRS]) at 90 days indicating no disability using an unconditional mixed-effect logistic-regression model fitted to estimate the treatment effect. Secondary outcomes were mRS shift towards a better functional outcome and independent outcome (mRS 0-2) at 90 days. Safety outcomes included death, severe disability or death (mRS score 4-6), and symptomatic intracranial haemorrhage. This study is registered with PROSPERO, CRD42020166903. FINDINGS: Of 249 identified abstracts, four trials met our eligibility criteria for inclusion: WAKE-UP, EXTEND, THAWS, and ECASS-4. The four trials provided individual patient data for 843 individuals, of whom 429 (51%) were assigned to alteplase and 414 (49%) to placebo or standard care. A favourable outcome occurred in 199 (47%) of 420 patients with alteplase and in 160 (39%) of 409 patients among controls (adjusted odds ratio [OR] 1·49 [95% CI 1·10-2·03]; p=0·011), with low heterogeneity across studies (I2=27%). Alteplase was associated with a significant shift towards better functional outcome (adjusted common OR 1·38 [95% CI 1·05-1·80]; p=0·019), and a higher odds of independent outcome (adjusted OR 1·50 [1·06-2·12]; p=0·022). In the alteplase group, 90 (21%) patients were severely disabled or died (mRS score 4-6), compared with 102 (25%) patients in the control group (adjusted OR 0·76 [0·52-1·11]; p=0·15). 27 (6%) patients died in the alteplase group and 14 (3%) patients died among controls (adjusted OR 2·06 [1·03-4·09]; p=0·040). The prevalence of symptomatic intracranial haemorrhage was higher in the alteplase group than among controls (11 [3%] vs two [<1%], adjusted OR 5·58 [1·22-25·50]; p=0·024). INTERPRETATION: In patients who have had a stroke with unknown time of onset with a DWI-FLAIR or perfusion mismatch, intravenous alteplase resulted in better functional outcome at 90 days than placebo or standard care. A net benefit was observed for all functional outcomes despite an increased risk of symptomatic intracranial haemorrhage. Although there were more deaths with alteplase than placebo, there were fewer cases of severe disability or death. FUNDING: None.

Tenecteplase versus Alteplase before Thrombectomy for Ischemic Stroke.

BACKGROUND: Intravenous infusion of alteplase is used for thrombolysis before endovascular thrombectomy for ischemic stroke. Tenecteplase, which is more fibrin-specific and has longer activity than alteplase, is given as a bolus and may increase the incidence of vascular reperfusion. METHODS: We randomly assigned patients with ischemic stroke who had occlusion of the internal carotid, basilar, or middle cerebral artery and who were eligible to undergo thrombectomy to receive tenecteplase (at a dose of 0.25 mg per kilogram of body weight; maximum dose, 25 mg) or alteplase (at a dose of 0.9 mg per kilogram; maximum dose, 90 mg) within 4.5 hours after symptom onset. The primary outcome was reperfusion of greater than 50% of the involved ischemic territory or an absence of retrievable thrombus at the time of the initial angiographic assessment. Noninferiority of tenecteplase was tested, followed by superiority. Secondary outcomes included the modified Rankin scale score (on a scale from 0 [no neurologic deficit] to 6 [death]) at 90 days. Safety outcomes were death and symptomatic intracerebral hemorrhage. RESULTS: Of 202 patients enrolled, 101 were assigned to receive tenecteplase and 101 to receive alteplase. The primary outcome occurred in 22% of the patients treated with tenecteplase versus 10% of those treated with alteplase (incidence difference, 12 percentage points; 95% confidence interval [CI], 2 to 21; incidence ratio, 2.2; 95% CI, 1.1 to 4.4; P=0.002 for noninferiority; P=0.03 for superiority). Tenecteplase resulted in a better 90-day functional outcome than alteplase (median modified Rankin scale score, 2 vs. 3; common odds ratio, 1.7; 95% CI, 1.0 to 2.8; P=0.04). Symptomatic intracerebral hemorrhage occurred in 1% of the patients in each group. CONCLUSIONS: Tenecteplase before thrombectomy was associated with a higher incidence of reperfusion and better functional outcome than alteplase among patients with ischemic stroke treated within 4.5 hours after symptom onset. (Funded by the National Health and Medical Research Council of Australia and others; EXTEND-IA TNK ClinicalTrials.gov number, NCT02388061 .).

Permeability Measures Predict Hemorrhagic Transformation after Ischemic Stroke.

OBJECTIVE: We sought to examine the diagnostic utility of existing predictors of any hemorrhagic transformation (HT) and compare them with new perfusion imaging permeability measures in ischemic stroke patients receiving alteplase only. METHODS: A pixel-based analysis of pretreatment CT perfusion (CTP) was undertaken to define the optimal CTP permeability thresholds to predict the likelihood of HT. We then compared previously proposed predictors of HT using regression analyses and receiver operating characteristic curve analysis to produce an area under the curve (AUC). We compared AUCs using χ2 analysis. RESULTS: From 5 centers, 1,407 patients were included in this study; of these, 282 had HT. The cohort was split into a derivation cohort (1,025, 70% patients) and a validation cohort (382 patients or 30%). The extraction fraction (E) permeability map at a threshold of 30% relative to contralateral had the highest AUC at predicting any HT (derivation AUC 0.85, 95% confidence interval [CI], 0.79-0.91; validation AUC 0.84, 95% CI 0.77-0.91). The AUC improved when permeability was assessed within the acute perfusion lesion for the E maps at a threshold of 30% (derivation AUC 0.91, 95% CI 0.86-0.95; validation AUC 0.89, 95% CI 0.86-0.95). Previously proposed associations with HT and parenchymal hematoma showed lower AUC values than the permeability measure. INTERPRETATION: In this large multicenter study, we have validated a highly accurate measure of HT prediction. This measure might be useful in clinical practice to predict hemorrhagic transformation in ischemic stroke patients before receiving alteplase alone. ANN NEUROL 2020;88:466-476.

Quality of Care and One-Year Outcomes in Patients with Diabetes Hospitalised for Stroke or TIA: A Linked Registry Study.

OBJECTIVES: To evaluate key quality indicators for acute care and one-year outcomes following acute ischaemic stroke (IS), intracerebral haemorrhage (ICH), or transient ischaemic attack (TIA) by diabetes status. MATERIALS AND METHODS: Observational cohort study (2009-2013) using linked data from the Australian Stroke Clinical Registry and hospital records. Diabetes was ascertained through review of hospital records. Multilevel regression models were used to evaluate the association between diabetes and outcomes, including discharge destination, and mortality and hospital readmissions within one-year of stroke/TIA. RESULTS: Among 14,132 patients (median age 76 years, 46% female), 22% had diabetes. Compared to patients without diabetes, those with diabetes were equally likely to receive stroke unit care, but were more often discharged on antihypertensive agents (79% vs. 68%) or with a care plan (50% vs. 47%). In patients with TIA, although 86% returned directly home after acute care, those with diabetes more often had a different discharge destination than those without diabetes. Diabetes was associated with greater all-cause mortality (hazard ratio 1.13, 95% CI 1.04-1.23) in patients with IS/ICH; and with both greater all-cause (1.81, CI 1.35-2.43) and CVD mortality (1.75, CI 1.06-2.91) in patients with TIA. Similarly, diabetes was associated with greater rates of all-cause readmission in both patients with IS/ICH and TIA. CONCLUSIONS: Despite good adherence to best care standards for acute stroke/TIA, patients with comorbid diabetes had worse outcomes at one-year than those without comorbid diabetes. Associations of diabetes with poorer outcomes were more pronounced in patients with TIA than those with IS/ICH.