Ninety-Day Stroke Recurrence in Minor Stroke: Systematic Review and Meta-Analysis of Trials and Observational Studies

BACKGROUND

Risk of recurrence after minor ischemic stroke is usually reported with transient ischemic attack. No previous meta-analysis has focused on minor ischemic stroke alone. The objective was to evaluate the pooled proportion of 90-day stroke recurrence for minor ischemic stroke, defined as a National Institutes of Health Stroke Scale severity score of ≤5.

METHODS AND RESULTS

Published papers found on PubMed from 2000 to January 12, 2021, reference lists of relevant articles, and experts in the field were involved in identifying relevant studies. Randomized controlled trials and observational studies describing minor stroke cohort with reported 90-day stroke recurrence were selected by 2 independent reviewers. Altogether 14 of 432 (3.2%) studies met inclusion criteria. Multilevel random-effects meta-analysis was performed. A total of 6 randomized controlled trials and 8 observational studies totaling 45 462 patients were included. The pooled 90-day stroke recurrence was 8.6% (95% CI, 6.5-10.7), reducing by 0.60% (95% CI, 0.09-1.1; P=0.02) with each subsequent year of publication. Recurrence was lowest in dual antiplatelet trial arms (6.3%, 95% CI, 4.5-8.0) when compared with non-dual antiplatelet trial arms (7.2%, 95% CI, 4.7-9.6) and observational studies 10.6% (95% CI, 7.0-14.2). Age, hypertension, diabetes, ischemic heart disease, or known atrial fibrillation had no significant association with outcome. Defining minor stroke with a lower National Institutes of Health Stroke Scale threshold made no difference - score ≤3: 8.6% (95% CI, 6.0-11.1), score ≤4: 8.4% (95% CI, 6.1-10.6), as did excluding studies with n<500%-7.3% (95% CI, 5.5-9.0).

CONCLUSIONS

The risk of recurrence after minor ischemic stroke is declining over time but remains important.

A Randomized Controlled Trial of Tenecteplase Versus Standard of Care for Minor Ischemic Stroke With Proven Occlusion (TEMPO-2): Rational and design of a multicenter, randomized open-label clinical trial

BACKGROUND

Almost half of acute ischemic stroke patients present with mild symptoms and there are large practice variations in their treatment globally. Individuals with an intracranial occlusion who present with minor stroke are at an increased risk of early neurological deterioration and poor outcomes. Individual patient data meta-analysis in the subgroup of patients with minor deficits showed benefit of alteplase in improving outcomes, however, this benefit has not been seen with intravenous alteplase in published randomized trials.

DESIGN

TEMPO-2 (A Randomized Controlled Trial of tenecteplase Versus Standard of Care for Minor Ischemic Stroke With Proven Occlusion) is a prospective, open label with blinded outcome assessment, randomized controlled trial, designed to test the superiority of intravenous tenecteplase (0.25mg/kg) over non thrombolytic standard of care, with an estimated sample size of 1274 patients. Adult patients presenting with acute ischemic stroke with NIHSS <5 and visible arterial occlusion or perfusion deficit within 12 hours of onset are randomized to receive either tenecteplase (0.25 mg/kg) or standard of care. The primary outcome is return to baseline neurological functioning, measured by the modified Rankin Scale (mRS) at 90 days. Safety outcomes include death and symptomatic hemorrhage (intra or extra-cranial). Other secondary outcomes include mRS 0-1, mRS 0-2, ordinal shift analysis of the mRS, partial and full recanalization on follow up CT Angiogram.

CONCLUSION

Results of this trial will aid in determining whether there is benefit of using tenecteplase (0.25mg/kg) in treating patients presenting with minor stroke who are at high risk of developing poor outcomes due to presence of an intracranial occlusion.

TRIAL REGISTRY NAME

A Randomized Controlled Trial of tenecteplase Versus Standard of Care for Minor Ischemic Stroke With Proven Occlusion, Registration number: NCT02398656; URL: https://clinicaltrials.gov/study/NCT02398656.

Magnetic Resonance Imaging Assists With Determining Etiology After Transient Ischemic Attack or Minor Stroke

BACKGROUND

Magnetic resonance imaging infarct topography may assist with determining stroke etiology. The influence of diffusion-weighted imaging (DWI)-positive lesions on etiology determination in patients with transient ischemic attack or minor stroke is not well studied.

METHODS AND RESULTS

We prospectively enrolled patients between 2010 and 2017 in 2 studies; participants with a final diagnosis of probable or definite transient ischemic attack or stroke were pooled for analysis. The primary outcome was the adjudicated ischemic etiology. We compared proportion of each etiology (cardioembolic, large-vessel, small-vessel disease, other) in patients who had DWI positivity compared with DWI negativity. We used logistic regression to determine the adjusted odds ratio (OR) for each etiology compared with undetermined by DWI positivity. The final analysis included 1498 patients: 832 (55.5%) were DWI-positive. DWI-positive patients were more likely to be diagnosed with small-vessel disease (19.1% versus 5.3%) and less likely with undetermined etiology (36.9% versus 53.0%; P<0.001). After adjustment, the presence of any DWI lesion was associated with increased odds of assigning any etiology (OR, 1.8 [95% CI, 1.3-2.5]). A single DWI lesion was associated with increased odds of small-vessel disease diagnosis (OR, 9.5 [95% CI, 6.4-14.0]), and multiple DWI lesions with reduced odds of small-vessel disease (OR, 0.2 [95% CI, 0.1-0.4]) but increased odds of all other etiologies compared with undetermined etiology.

CONCLUSIONS

Any DWI-positive lesion after suspected transient ischemic attack or minor stroke was associated with increased odds of assigning a etiology. Presence and topography of DWI lesions on magnetic resonance imaging may assist with etiology determination and may impact stroke prevention therapies.

Safety and efficacy of tenecteplase versus alteplase in stroke patients with carotid tandem lesions: Results from the AcT trial

BACKGROUND

Carotid tandem lesions ((TL) ⩾70% stenosis or occlusion) account for 15-20% of acute stroke with large vessel occlusion.

AIMS

We investigated the safety and efficacy of intravenous tenecteplase (0.25 mg/kg) versus intravenous alteplase (0.9 mg/kg) in patients with carotid TL.

METHODS

This is a substudy of the alteplase compared with the tenecteplase trial. Patients with ⩾70% stenosis of the extracranial internal carotid artery (ICA) and concomitant occlusion of the intracranial ICA, M1 or M2 segments of the middle cerebral artery on baseline computed tomography angiography (CTA) were included. Primary outcome was 90-day-modified Rankin Scale (mRS) 0-1. Secondary outcomes were mRS 0-2, mortality, and symptomatic ICH (sICH). Angiographic outcomes were successful recanalization (revised Arterial Occlusive Lesion (rAOL) 2b-3) on first and successful reperfusion (eTICI 2b-3) on final angiographic acquisitions. Multivariable mixed-effects logistic regression was performed.

RESULTS

Among 1577 alteplase versus tenecteplase randomized controlled trial (AcT) patients, 128 (18.8%) had carotid TL. Of these, 93 (72.7%) underwent intravenous thrombolysis plus endovascular thrombectomy (IVT + EVT), while 35 (27.3%) were treated with IVT alone. In the IVT + EVT group, tenecteplase was associated with higher odds of 90-day-mRS 0-1 (46.0% vs. 32.6%, adjusted OR (aOR) 3.21; 95% CI = 1.06-9.71) compared with alteplase. No statistically significant differences in rates of mRS 0-2 (aOR 1.53; 95% CI = 0.51-4.55), initial rAOL 2b-3 (16.3% vs. 28.6%), final eTICI 2b-3 (83.7% vs. 85.7%), and mortality (18.0% vs. 16.3%) were found. SICH only occurred in one patient. There were no differences in outcomes between thrombolytic agents in the IVT-only group.

CONCLUSION

In patients with carotid TL treated with EVT, intravenous tenecteplase may be associated with similar or better clinical outcomes, similar angiographic reperfusion rates, and safety outcomes as compared with alteplase.

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.

Rapid outpatient transient ischemic attack clinic and stroke service activity during the SARS-CoV-2 pandemic: a multicenter time series analysis

Background and aim

Rapid outpatient evaluation and treatment of TIA in structured clinics have been shown to reduce stroke recurrence. It is unclear whether short-term downtrends in TIA incidence and admissions have had enduring impact on TIA clinic activity. This study aims to measure the impact of the pandemic on hospitals with rapid TIA clinics.

Methods

Relevant services were identified by literature search and contacted. Three years of monthly data were requested - a baseline pre-COVID period (April 2018 to March 2020) and an intra-COVID period (April 2020 to March 2021). TIA presentations, ischemic stroke presentations, and reperfusion trends inclusive of IV thrombolysis (IVT) and endovascular thrombectomy (EVT) were recorded. Pandemic impact was measured with interrupted time series analysis, a segmented regression approach to test an effect of an intervention on a time-dependent outcome using a defined impact model.

Results

Six centers provided data for a total of 6,231 TIA and 13,191 ischemic stroke presentations from Australia (52.1%), Canada (35.0%), Italy (7.6%), and England (5.4%). TIA clinic volumes remained constant during the pandemic (2.9, 95% CI -1.8 to 7.6, p = 0.24), as did ischemic stroke (2.9, 95% CI -7.8 to 1.9, p = 0.25), IVT (-14.3, 95% CI -36.7, 6.1, p < 0.01), and EVT (0, 95% CI -16.9 to 16.9, p = 0.98) counts. Proportion of ischemic strokes requiring IVT decreased from 13.2 to 11.4% (p < 0.05), but those requiring EVT did not change (16.0 to 16.7%, p = 0.33).

Conclusion

This suggests that the pandemic has not had an enduring effect on TIA clinic or stroke service activity for these centers. Furthermore, the disproportionate decrease in IVT suggests that patients may be presenting outside the IVT window during the pandemic - delays in seeking treatment in this group could be the target for public health intervention.

Sex-Based Analysis of Workflow and Outcomes in Acute Ischemic Stroke Patients Treated With Alteplase Versus Tenecteplase

BACKGROUND

Understanding sex differences in stroke care is important in reducing potential disparities. Our objective was to explore sex differences in workflow efficiency, treatment efficacy, and safety in the AcT trial (Alteplase Compared to Tenecteplase).

METHODS

AcT was a multicenter, registry-linked randomized noninferiority trial comparing tenecteplase (0.25 mg/kg) with alteplase (0.9 mg/kg) in acute ischemic stroke within 4.5 hours of onset. In this post hoc analysis, baseline characteristics, workflow times, successful reperfusion (extended Thrombolysis in Cerebral Infarction score ≥2b), symptomatic intracerebral hemorrhage, 90-day functional independence (modified Rankin Scale score, 0-1), and 90-day mortality were compared by sex. Mixed-effects regression analysis was used adjusting for age, stroke severity, and occlusion site for outcomes.

RESULTS

Of 1577 patients treated with intravenous thrombolysis (2019-2022), 755 (47.9%) were women. Women were older (median, 77 [68-86] years in women versus 70 [59-79] years in men) and had a higher proportion of severe strokes (National Institutes of Health Stroke Scale score >15; 32.4% versus 24.9%) and large vessel occlusions (28.7% versus 21.5%) compared with men. All workflow times were comparable between sexes. Women were less likely to achieve functional independence (31.7% versus 39.8%; unadjusted relative risk, 0.80 [95% CI, 0.70-0.91]) and had higher mortality (17.7% versus 13.3%; unadjusted relative risk, 1.33 [95% CI, 1.06-1.69]). Adjusted analysis showed no difference in outcomes between sexes.

CONCLUSIONS

Differences in prognostic factors of age, stroke severity, and occlusion site largely accounted for higher functional dependence and mortality in women. No sex disparities were apparent in workflow quality indicators. Given the integration of the AcT trial into clinical practice, these results provide reassurance that no major sex biases are apparent in acute stroke management throughout participating Canadian centers.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03889249.

Apixaban for Stroke Prevention in Subclinical Atrial Fibrillation

BACKGROUND

Subclinical atrial fibrillation is short-lasting and asymptomatic and can usually be detected only by long-term continuous monitoring with pacemakers or defibrillators. Subclinical atrial fibrillation is associated with an increased risk of stroke by a factor of 2.5; however, treatment with oral anticoagulation is of uncertain benefit.

METHODS

We conducted a trial involving patients with subclinical atrial fibrillation lasting 6 minutes to 24 hours. Patients were randomly assigned in a double-blind, double-dummy design to receive apixaban at a dose of 5 mg twice daily (2.5 mg twice daily when indicated) or aspirin at a dose of 81 mg daily. The trial medication was discontinued and anticoagulation started if subclinical atrial fibrillation lasting more than 24 hours or clinical atrial fibrillation developed. The primary efficacy outcome, stroke or systemic embolism, was assessed in the intention-to-treat population (all the patients who had undergone randomization); the primary safety outcome, major bleeding, was assessed in the on-treatment population (all the patients who had undergone randomization and received at least one dose of the assigned trial drug, with follow-up censored 5 days after permanent discontinuation of trial medication for any reason).

RESULTS

We included 4012 patients with a mean (±SD) age of 76.8±7.6 years and a mean CHA2DS2-VASc score of 3.9±1.1 (scores range from 0 to 9, with higher scores indicating a higher risk of stroke); 36.1% of the patients were women. After a mean follow-up of 3.5±1.8 years, stroke or systemic embolism occurred in 55 patients in the apixaban group (0.78% per patient-year) and in 86 patients in the aspirin group (1.24% per patient-year) (hazard ratio, 0.63; 95% confidence interval [CI], 0.45 to 0.88; P = 0.007). In the on-treatment population, the rate of major bleeding was 1.71% per patient-year in the apixaban group and 0.94% per patient-year in the aspirin group (hazard ratio, 1.80; 95% CI, 1.26 to 2.57; P = 0.001). Fatal bleeding occurred in 5 patients in the apixaban group and 8 patients in the aspirin group.

CONCLUSIONS

Among patients with subclinical atrial fibrillation, apixaban resulted in a lower risk of stroke or systemic embolism than aspirin but a higher risk of major bleeding. (Funded by the Canadian Institutes of Health Research and others; ARTESIA ClinicalTrials.gov number, NCT01938248.).

Presenting Symptoms and Diffusion-Weighted MRI Positivity by Time After Transient Neurologic Events: A Pooled Analysis of 3 Cohort Studies

BACKGROUND AND OBJECTIVE

The association between focal vs nonfocal presenting symptom and diffusion-weighted imaging (DWI) positivity in relation to onset-to-imaging time in patients with transient neurologic events remains unclear. We hypothesize that episodes consisting of focal symptoms would have proportionally higher DWI-positive imaging at later onset-to-imaging times.

METHODS

Patients with transient neurologic symptoms and a normal neurologic examination who had DWI in the combined data set of 3 cohort studies were included. We used logistic regression models to evaluate the association between each type of presenting symptom (motor weakness, speech impairment, sensory symptoms, vision loss, diplopia, gait instability, dizziness, headache, presyncope, and amnesia) and DWI positivity after adjusting for clinical variables (age, sex, history of stroke, dyslipidemia, coronary artery disease, atrial fibrillation, symptoms duration [<10, 10-59, ≥60 minutes, or unclear], and study source). We stratified the results by onset-to-imaging time categories (<6 hours, 6-23 hours, and ≥24 hours).

RESULTS

Of the total 2,411 patients (1,345 male, median age 68 years), DWI-positive lesions were detected in 598 patients (24.8%). The prevalence of DWI positivity was highest in those with motor weakness (34.7%), followed by speech impairment (33.5%). In a multivariable analysis, the presence of motor weakness, speech impairment, and sensory symptoms was associated with DWI positivity, while vision loss and headache were associated with lower odds of DWI positivity, but nevertheless had 13.6% and 15.3% frequency of DWI positive. The odds of being DWI positive varied by onset-to-imaging time categories for motor weakness, with greater odds of being DWI positive at later imaging time (<6 hours: odds ratio [OR] 1.25, 95% confidence interval [CI] 0.84-1.87; 6-23 hours: OR 2.24, 95% CI 1.47-3.42; and ≥24 hours: OR 2.42, 95% CI 1.74-3.36; interaction p = 0.033). Associations of other symptoms with DWI positivity did not vary significantly by time categories.

DISCUSSION

We found that onset-to-imaging time influences the relationship between motor weakness and DWI positivity in patients with transient neurologic events. Compared with motor, speech, and sensory symptoms, visual or nonfocal symptoms carry a lower but still a substantive association with DWI positivity.

Effect of Time to Thrombolysis on Clinical Outcomes in Patients With Acute Ischemic Stroke Treated With Tenecteplase Compared to Alteplase: Analysis From the AcT Randomized Controlled Trial

BACKGROUND

The AcT (Alteplase Compared to Tenecteplase) randomized controlled trial showed that tenecteplase is noninferior to alteplase in treating patients with acute ischemic stroke within 4.5 hours of symptom onset. The effect of time to treatment on clinical outcomes with alteplase is well known; however, the nature of this relationship is yet to be described with tenecteplase. We assessed whether the association of time to thrombolysis treatment with clinical outcomes in patients with acute ischemic stroke differs by whether they receive intravenous tenecteplase versus alteplase.

METHODS

Patients included were from AcT, a pragmatic, registry-linked, phase 3 randomized controlled trial comparing intravenous tenecteplase to alteplase in patients with acute ischemic stroke. Eligible patients were >18 years old, with disabling neurological deficits, presenting within 4.5 hours of symptom onset, and eligible for thrombolysis. Primary outcome was modified Rankin Scale score 0 to 1 at 90 days. Safety outcomes included 24-hour symptomatic intracerebral hemorrhage and 90-day mortality rates. Mixed-effects logistic regression was used to assess the following: (a) the association of stroke symptom onset to needle time; (b) door (hospital arrival) to needle time with outcomes; and (c) if these associations were modified by type of thrombolytic administered (tenecteplase versus alteplase), after adjusting for age, sex, baseline stroke severity, and site of intracranial occlusion.

RESULTS

Of the 1538 patients included in this analysis, 1146 (74.5%; 591 tenecteplase and 555 alteplase) presented within 3 hours versus 392 (25.5%; 196: TNK and 196 alteplase) who presented within 3 to 4.5 hours of symptom onset. Baseline patient characteristics in the 0 to 3 hours versus 3- to 4.5-hour time window were similar, except patients in the 3- to 4.5-hour window had lower median baseline National Institutes of Health Stroke Severity Scale (10 versus 7, respectively) and lower proportion of patients with large vessel occlusion on baseline CT angiography (26.9% versus 18.7%, respectively). Type of thrombolytic agent (tenecteplase versus alteplase) did not modify the association between continuous onset to needle time (Pinteraction=0.161) or door-to-needle time (Pinteraction=0.972) and primary clinical outcome. Irrespective of the thrombolytic agent used, each 30-minute reduction in onset to needle time was associated with a 1.8% increase while every 10 minutes reduction in door-to-needle time was associated with a 0.2% increase in the probability of achieving 90-day modified Rankin Scale score 0 to 1, respectively.

CONCLUSIONS

The effect of time to tenecteplase administration on clinical outcomes is like that of alteplase, with faster administration resulting in better clinical outcomes.

REGISTRATION

URL: https://classic.

CLINICALTRIALS

gov; Unique identifier: NCT03889249.

Exploring sex differences for acute ischemic stroke clinical, imaging and thrombus characteristics in the INTERRSeCT study

Women, especially following menopause, are known to have worse outcomes following acute ischemic stroke. One primary postulated biological mechanism for worse outcomes in older women is a reduction in the vasculoprotective effects of estrogen. Using the INTERRseCT cohort, a multicentre international observational cohort studying recanalization in acute ischemic stroke, we explored the effects of sex, and modifying effects of age, on neuroradiological predictors of recanalization including robustness of leptomeningeal collaterals, thrombus burden and thrombus permeability. Ordinal regression analyses were used to examine the relationship between sex and each of the neuroradiological markers. Further, we explored both multiplicative and additive interactions between age and sex. All patients (n = 575) from INTERRseCT were included. Mean age was 70.2 years (SD: 13.1) and 48.5% were women. In the unadjusted model, female sex was associated with better collaterals (OR 1.37, 95% CIs: 1.01-1.85), however this relationship was not significant after adjusting for age and relevant comorbidities. There were no significant interactions between age and sex. In a large prospective international cohort, we found no association between sex and radiological predictors of recanalization including leptomeningeal collaterals, thrombus permeability and thrombus burden.

Safety and Efficacy of Tenecteplase Compared With Alteplase in Patients With Large Vessel Occlusion Stroke: A Prespecified Secondary Analysis of the ACT Randomized Clinical Trial

Importance

It is unknown whether intravenous thrombolysis using tenecteplase is noninferior or preferable compared with alteplase for patients with acute ischemic stroke.

Objective

To examine the safety and efficacy of tenecteplase compared to alteplase among patients with large vessel occlusion (LVO) stroke.

Design, Setting, and Participants

This was a prespecified analysis of the Intravenous Tenecteplase Compared With Alteplase for Acute Ischaemic Stroke in Canada (ACT) randomized clinical trial that enrolled patients from 22 primary and comprehensive stroke centers across Canada between December 10, 2019, and January 25, 2022. Patients 18 years and older with a disabling ischemic stroke within 4.5 hours of symptom onset were randomly assigned (1:1) to either intravenous tenecteplase or alteplase and were monitored for up to 120 days. Patients with baseline intracranial internal carotid artery (ICA), M1-middle cerebral artery (MCA), M2-MCA, and basilar occlusions were included in this analysis. A total of 1600 patients were enrolled, and 23 withdrew consent.

Exposures

Intravenous tenecteplase (0.25 mg/kg) vs intravenous alteplase (0.9 mg/kg).

Main Outcomes and Measures

The primary outcome was the proportion of modified Rankin scale (mRS) score 0-1 at 90 days. Secondary outcomes were an mRS score from 0 to 2, mortality, and symptomatic intracerebral hemorrhage. Angiographic outcomes were successful reperfusion (extended Thrombolysis in Cerebral Infarction scale score 2b-3) on first and final angiographic acquisitions. Multivariable analyses (adjusting for age, sex, National Institute of Health Stroke Scale score, onset-to-needle time, and occlusion location) were carried out.

Results

Among 1577 patients, 520 (33.0%) had LVO (median [IQR] age, 74 [64-83] years; 283 [54.4%] women): 135 (26.0%) with ICA occlusion, 237 (45.6%) with M1-MCA, 117 (22.5%) with M2-MCA, and 31 (6.0%) with basilar occlusions. The primary outcome (mRS score 0-1) was achieved in 86 participants (32.7%) in the tenecteplase group vs 76 (29.6%) in the alteplase group. Rates of mRS 0-2 (129 [49.0%] vs 131 [51.0%]), symptomatic intracerebral hemorrhage (16 [6.1%] vs 11 [4.3%]), and mortality (19.9% vs 18.1%) were similar in the tenecteplase and alteplase groups, respectively. No difference was noted in successful reperfusion rates in the first (19 [9.2%] vs 21 [10.5%]) and final angiogram (174 [84.5%] vs 177 [88.9%]) among 405 patients who underwent thrombectomy.

Conclusions and Relevance

The findings in this study indicate that intravenous tenecteplase conferred similar reperfusion, safety, and functional outcomes compared to alteplase among patients with LVO.

Impact of Cerebral Microbleeds in Stroke Patients with Atrial Fibrillation

OBJECTIVES

Cerebral microbleeds are associated with the risks of ischemic stroke and intracranial hemorrhage, causing clinical dilemmas for antithrombotic treatment decisions. We aimed to evaluate the risks of intracranial hemorrhage and ischemic stroke associated with microbleeds in patients with atrial fibrillation treated with vitamin K antagonists, direct oral anticoagulants, antiplatelets, and combination therapy (i.e. concurrent oral anticoagulant and antiplatelet).

METHODS

We included patients with documented atrial fibrillation from the pooled individual patient data analysis by the Microbleeds International Collaborative Network. Risks of subsequent intracranial hemorrhage and ischemic stroke were compared between patients with and without microbleeds, stratified by antithrombotic use.

RESULTS

A total of 7,839 patients were included. The presence of microbleeds was associated with an increased relative risk of intracranial hemorrhage (adjusted hazard ratio [aHR] = 2.74, 95% confidence interval = 1.76-4.26) and ischemic stroke (aHR = 1.29, 95% confidence interval = 1.04-1.59). For the entire cohort, the absolute incidence of ischemic stroke was higher than intracranial hemorrhage regardless of microbleed burden. However, for the subgroup of patients taking combination of anticoagulant and antiplatelet therapy, the absolute risk of intracranial hemorrhage exceeded that of ischemic stroke in those with 2 to 4 microbleeds (25 vs 12 per 1,000 patient-years) and ≥ 11 microbleeds (94 vs 48 per 1,000 patient-years).

INTERPRETATION

Patients with atrial fibrillation and high burden of microbleeds receiving combination therapy have a tendency of higher rate of intracranial hemorrhage than ischemic stroke, with potential for net harm. Further studies are needed to help optimize stroke preventive strategies in this high-risk group. ANN NEUROL 2023;94:61-74.

Endovascular thrombectomy for basilar artery occlusion: translating research findings into clinical practice

BACKGROUND

Basilar artery occlusion is a rare and severe condition. The effectiveness of endovascular thrombectomy in patients with basilar artery occlusion was unclear until recently, because these patients were excluded from most trials of endovascular thrombectomy for large-vessel occlusion ischaemic stroke.

RECENT DEVELOPMENTS

The Basilar Artery International Cooperation Study (BASICS) and the Basilar Artery Occlusion Endovascular Intervention versus Standard Medical Treatment (BEST) trials, specifically designed to investigate the benefit of thrombectomy in patients with basilar artery occlusion, did not find significant evidence of a benefit of endovascular thrombectomy in terms of disability outcomes at 3 months after stroke. However, these trials suggested a potential benefit of endovascular thrombectomy in patients presenting with moderate-to-severe symptoms. Subsequently, the Endovascular Treatment for Acute Basilar Artery Occlusion (ATTENTION) and the Basilar Artery Occlusion Chinese Endovascular (BAOCHE) trials, which compared endovascular thrombectomy versus medical therapy within 24 h of onset, showed clear benefit of endovascular thrombectomy in reducing disability and mortality, particularly in patients with moderate-to-severe symptoms. The risk of intracranial haemorrhage with endovascular thrombectomy was similar to the risk in anterior circulation stroke. Thrombectomy was beneficial regardless of age, baseline characteristics, the presence of intracranial atherosclerotic disease, and time from symptom onset to randomisation. Therefore, the question of whether endovascular thrombectomy is beneficial in basilar artery occlusion now appears to be settled in patients with moderate-to-severe symptoms, and endovascular thrombectomy should be offered to eligible patients. WHERE NEXT?: Key outstanding issues are the potential benefits of endovascular thrombectomy in patients with mild symptoms, the use of intravenous thrombolysis in an extended time window (ie, after 4·5 h of symptom onset), and the optimal endovascular technique for thrombectomy. Dedicated training programmes and automated software to assist with the assessment of imaging prognostic markers could be useful in the selection of patients who might benefit from endovascular thrombectomy. Large international research networks should be built to address knowledge gaps in this field and allow the conduct of clinical trials with fast and consecutive enrolment and a diverse ethnic representation.

Effects of a Province-wide Triaging System for TIA: The ASPIRE Intervention

BACKGROUND

Urgent transient ischemic attack (TIA) management to reduce stroke recurrence is challenging, particularly in rural and remote areas. In Alberta, Canada despite an organized stroke system, data from 1999-2000 suggested that stroke recurrence after TIA was as high as 9.5% at 90 days. Our objective was to determine if a multi-faceted population based intervention resulted in a reduction in recurrent stroke following TIA.

METHODS

In this quasi-experimental health services research intervention study we implemented a TIA management algorithm across the entire province, centered around a 24-hour physician's TIA Hotline as well as public and health provider education on TIA. From administrative databases we linked emergency department discharge abstracts to hospital discharge abstracts to identify incident TIAs and recurrent strokes at 90 days across a single payer system with validation of recurrent stroke events. The primary outcome was recurrent stroke; with a secondary composite outcome of recurrent stroke, acute coronary syndrome, and all cause death. We used an interrupted time series regression analysis of age and sex-adjusted stroke recurrence rates after TIA incorporating a two-year pre-implementation period (2007-2009), a 15 month implementation period, and a two-year post-implementation period (2010-2012). Logistic regression was used to examine outcomes that did not fit the time series model.

RESULTS

We assessed 6 715 patients pre- and 6 956 patients post-implementation. The 90-day stroke recurrence rate in the pre-ASPIRE period was 4.5% compared to 5.3% during the post-ASPIRE period. There was neither a step change (estimate 0.38; p=0.65) nor slope change (parameter estimate 0.30; p=0.12) in recurrent stroke rates associated with the ASPIRE intervention implementation period. Adjusted all-cause mortality (OR 0.71 95%CI [0.56, 0.89]) was significantly lower following the ASPIRE intervention.

CONCLUSIONS

The ASPIRE TIA triaging and management interventions did not further reduce stroke recurrence in the context of an organized stroke system. The apparent lower mortality post intervention may be related to improved surveillance following events identified as TIAs but secular trends cannot be excluded.

Stroke Risk and Antithrombotic Treatment During Follow-up of Patients With Ischemic Stroke and Cortical Superficial Siderosis

BACKGROUND AND OBJECTIVES

In patients with ischemic stroke (IS) or transient ischemic attack (TIA) and cortical superficial siderosis (cSS), there are few data regarding the risk of future cerebrovascular events and also about the benefits and safety of antithrombotic drugs for secondary prevention. We investigated the associations of cSS and stroke risk in patients with recent IS or TIA.

METHODS

We retrospectively analyzed the Microbleeds International Collaborative Network (MICON) database. We selected patients with IS or TIA from cohorts who had MRI-assessed cSS, available data on antithrombotic treatments, recurrent cerebrovascular events (intracranial hemorrhage [ICrH], IS, or any stroke [ICrH or IS]), and mortality. We calculated incidence rates (IRs) and performed univariable and multivariable Cox regression analyses.

RESULTS

Of 12,669 patients (mean age 70.4 ± 12.3 years, 57.3% men), cSS was detected in 273 (2.2%) patients. During a mean follow-up of 24 ± 17 months, IS was more frequent than ICrH in both cSS (IR 57.1 vs 14.6 per 1,000 patient-years) and non-cSS (33.7 vs 6.3 per 1,000 patient-years) groups. Compared with the non-cSS group, cSS was associated with any stroke on multivariable analysis {IR 83 vs 42 per 1,000 patient-years, adjusted hazard ratio [HR] for cSS 1.62 (95% CI: 1.14-2.28; p = 0.006)}. This association was not significant in subgroups of patients treated with antiplatelet drugs (n = 6,554) or with anticoagulants (n = 4,044). Patients with cSS who were treated with both antiplatelet drugs and anticoagulants (n = 1,569) had a higher incidence of ICrH (IR 107.5 vs 4.9 per 1,000 patient-years, adjusted HR 13.26; 95% CI: 2.90-60.63; p = 0.001) and of any stroke (IR 198.8 vs 34.7 per 1,000 patient-years, adjusted HR 5.03; 95% CI: 2.03-12.44; p < 0.001) compared with the non-cSS group.

DISCUSSION

Patients with IS or TIA with cSS are at increased risk of stroke (ICrH or IS) during follow-up; the risk of IS exceeds that of ICrH for patients receiving antiplatelet or anticoagulant treatment alone, but the risk of ICrH exceeds that of IS in patients receiving both treatments. The findings suggest that either antiplatelet or anticoagulant treatment alone should not be avoided in patients with cSS, but combined antithrombotic therapy might be hazardous. Our findings need to be confirmed by randomized clinical trials.

Risk of Hemorrhagic Transformation with Early Use of Direct Oral Anticoagulants after Acute Ischemic Stroke: A Pooled Analysis of Prospective Studies and Randomized Trials

INTRODUCTION

Precise risk of hemorrhagic transformation (HT) in acute ischemic stroke (AIS) remains unknown, leading to delays in anticoagulation initiation for secondary stroke prevention. We sought to assess the rate of HT associated with direct oral anticoagulant (DOAC) initiation within and beyond 48 hours post-AIS.

METHODS

A pooled analysis of DOAC initiation within 14 days of AIS or transient ischemic attack (TIA) was conducted with 6 studies (4 prospective open label treatment, blinded outcome studies and 2 randomized trials; NCT02295826 and NCT02283294). The primary endpoint was incident radiographic HT on follow-up imaging (day 7-30). Secondary endpoints included symptomatic HT, new parenchymal hemorrhage, recurrent ischemic events, extracranial hemorrhage, study-period mortality, and follow-up modified Rankin Scale score. The results were reported as odds ratio (OR) or hazard ratio (HR) with 95% confidence interval (CI).

RESULTS

We evaluated 509 patients; median infarct volume was 1.5 (0.1-7.8) ml, and median National Institutes of Health Stroke Scale was 2 (0-3). Incident radiographic HT was seen on follow-up scan in 34 (6.8%) patients. DOAC initiation within 48 hours from index event was not associated with incident HT (adjusted OR 0.67, [0.30 - 1.50] P=0.32). No patients developed symptomatic HT. Conversely, 31 (6.1%) patients developed recurrent ischemic events, 64% of which occurred within 14 days. Initiating a DOAC within 48 hours of onset was associated with similar recurrent ischemic event rates compared to those in which treatment was delayed (HR 0.42, [0.17 - 1.008] P=0.052). In contrast to HT, recurrent ischemic events were associated with poor functional outcomes (OR=6.8, [2.84 - 16.24], p<0.001).

CONCLUSIONS

In this pooled analysis, initiation of DOAC within 48 hours post-stroke was not associated with increased incident risk of HT, and none developed symptomatic HT. The analysis was underpowered to determine the effect of early DOAC use upon recurrent ischemic events.

Association Between Duration of Transient Neurological Events and Diffusion-Weighted Brain Lesions

Background The relationship between duration of transient neurological events and presence of diffusion-weighted lesions by symptom type is unclear. Methods and Results This was a substudy of SpecTRA (Spectrometry for Transient Ischemic Attack Rapid Assessment), a multicenter prospective cohort of patients with minor ischemic cerebrovascular events or stroke mimics at academic emergency departments in Canada. For this study we included patients with resolved symptoms and determined the presence of diffusion-weighted imaging (DWI) lesion on magnetic resonance imaging within 7 days. Using logistic regression, we evaluated the association between symptom duration and DWI lesion, assessing for interaction with symptom type (focal only versus nonfocal/mixed), and adjusting for age, sex, education, comorbidities, and systolic blood pressure. Of 658 patients included, a DWI lesion was present in 232 (35.1%). There was a significant interaction between symptom duration and symptom type. For those with focal-only symptoms, there was a continuous increase in DWI probability up to 24 hours in duration (ranging from ≈40% to 80% probability). In stratified analyses, the increase in probability of DWI lesion with increased duration of focal symptoms was seen in women but not men. For those with nonfocal or mixed symptoms, predicted probability of DWI lesion was ≈35% and was greater in men, but did not increase with longer duration. Conclusions Increased duration of neurological deficits is associated with greater probability of DWI lesion in those with focal symptoms only. For individuals with nonfocal or mixed symptoms, about one-third had DWI lesions, but the probability did not increase with duration. These results may be important to improve risk stratification of transient neurological events.

Outcomes of Cerebral Venous Thrombosis due to Vaccine-Induced Immune Thrombotic Thrombocytopenia After the Acute Phase

BACKGROUND

Cerebral venous thrombosis (CVT) due to vaccine-induced immune thrombotic thrombocytopenia (VITT) is a severe condition, with high in-hospital mortality rates. Here, we report clinical outcomes of patients with CVT-VITT after SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) vaccination who survived initial hospitalization.

METHODS

We used data from an international registry of patients who developed CVT within 28 days of SARS-CoV-2 vaccination, collected until February 10, 2022. VITT diagnosis was classified based on the Pavord criteria. Outcomes were mortality, functional independence (modified Rankin Scale score 0-2), VITT relapse, new thrombosis, and bleeding events (all after discharge from initial hospitalization).

RESULTS

Of 107 CVT-VITT cases, 43 (40%) died during initial hospitalization. Of the remaining 64 patients, follow-up data were available for 60 (94%) patients (37 definite VITT, 9 probable VITT, and 14 possible VITT). Median age was 40 years and 45/60 (75%) patients were women. Median follow-up time was 150 days (interquartile range, 94-194). Two patients died during follow-up (3% [95% CI, 1%-11%). Functional independence was achieved by 53/60 (88% [95% CI, 78%-94%]) patients. No new venous or arterial thrombotic events were reported. One patient developed a major bleeding during follow-up (fatal intracerebral bleed).

CONCLUSIONS

In contrast to the high mortality of CVT-VITT in the acute phase, mortality among patients who survived the initial hospitalization was low, new thrombotic events did not occur, and bleeding events were rare. Approximately 9 out of 10 CVT-VITT patients who survived the acute phase were functionally independent at follow-up.

Alteplase or tenecteplase for thrombolysis in ischemic stroke: An illustrated review

Intravenous thrombolysis is a standard of care treatment for patients with acute ischemic stroke. Tissue plasminogen activator (tPA) has been the main thrombolytic agent used since the publication of the seminal National Institutes of Neurological Disorders and Stroke trial in 1995. There is now mounting evidence to support the routine use of Tenecteplase (TNK) to treat acute ischemic stroke. TNK is a genetically modified tPA with higher fibrin specificity, longer half‐life, and reduced systemic coagulopathy. In this illustrated review, we compare the indications, doses, mechanisms of action, efficacy and safety of TNK and tPA. We provide an overview of published clinical trials studying TNK in acute ischemic stroke, including dose‐escalation studies and head‐to‐head comparisons with tPA. Finally, we summarize current acute stroke guideline recommendations and suggest treatment algorithms to manage the two main complications of intravenous thrombolysis: symptomatic intracerebral hemorrhage and angioedema.

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.

Management of Cerebral Venous Thrombosis Due to Adenoviral COVID-19 Vaccination

Objective

Cerebral venous thrombosis (CVT) caused by vaccine‐induced immune thrombotic thrombocytopenia (VITT) is a rare adverse effect of adenovirus‐based severe acute respiratory syndrome‐coronavirus 2 (SARS‐CoV‐2) vaccines. In March 2021, after autoimmune pathogenesis of VITT was discovered, treatment recommendations were developed. These comprised immunomodulation, non‐heparin anticoagulants, and avoidance of platelet transfusion. The aim of this study was to evaluate adherence to these recommendations and its association with mortality.

Methods

We used data from an international prospective registry of patients with CVT after the adenovirus‐based SARS‐CoV‐2 vaccination. We analyzed possible, probable, or definite VITT‐CVT cases included until January 18, 2022. Immunomodulation entailed administration of intravenous immunoglobulins and/or plasmapheresis.

Results

Ninety‐nine patients with VITT‐CVT from 71 hospitals in 17 countries were analyzed. Five of 38 (13%), 11 of 24 (46%), and 28 of 37 (76%) of the patients diagnosed in March, April, and from May onward, respectively, were treated in‐line with VITT recommendations (p < 0.001). Overall, treatment according to recommendations had no statistically significant influence on mortality (14/44 [32%] vs 29/55 [52%], adjusted odds ratio [OR] = 0.43, 95% confidence interval [CI] = 0.16–1.19). However, patients who received immunomodulation had lower mortality (19/65 [29%] vs 24/34 [70%], adjusted OR = 0.19, 95% CI = 0.06–0.58). Treatment with non‐heparin anticoagulants instead of heparins was not associated with lower mortality (17/51 [33%] vs 13/35 [37%], adjusted OR = 0.70, 95% CI = 0.24–2.04). Mortality was also not significantly influenced by platelet transfusion (17/27 [63%] vs 26/72 [36%], adjusted OR = 2.19, 95% CI = 0.74–6.54).

Conclusions

In patients with VITT‐CVT, adherence to VITT treatment recommendations improved over time. Immunomodulation seems crucial for reducing mortality of VITT‐CVT. ANN NEUROL 2022;92:562–573

Ethical Justification for Deferral of Consent in the AcT Trial for Acute Ischemic Stroke

The AcT trial (Alteplase Compared to Tenecteplase) compares alteplase or tenecteplase for patients with acute ischemic stroke. All eligible patients are enrolled by deferral of consent. Although the use of deferral of consent in the AcT trial meets the requirements of Canadian policy, we sought to provide a more explicit and rigorous approach to the justification of deferral of consent organized around 3 questions. Ultimately, the approach we outline here could become the foundation for a general justification for deferral of consent.

Evaluating Rates of Recurrent Ischemic Stroke Among Young Adults With Embolic Stroke of Undetermined Source: The Young ESUS Longitudinal Cohort Study

Importance

Cryptogenic strokes constitute approximately 40% of ischemic strokes in young adults, and most meet criteria for the embolic stroke of undetermined source (ESUS). Two randomized clinical trials, NAVIGATE ESUS and RESPECT ESUS, showed a high rate of stroke recurrence in older adults with ESUS but the prognosis and prognostic factors among younger individuals with ESUS is uncertain.

Objective

To determine rates of and factors associated with recurrent ischemic stroke and death and new-onset atrial fibrillation (AF) among young adults.

Design, Setting, and Participants

This multicenter longitudinal cohort study with enrollment from October 2017 to October 2019 and a mean follow-up period of 12 months ending in October 2020 included 41 stroke research centers in 13 countries. Consecutive patients 50 years and younger with a diagnosis of ESUS were included. Of 576 screened, 535 participants were enrolled after 1 withdrew consent, 41 were found to be ineligible, and 2 were excluded for other reasons. The final follow-up visit was completed by 520 patients.

Main Outcomes and Measures

Recurrent ischemic stroke and/or death, recurrent ischemic stroke, and prevalence of patent foramen ovale (PFO).

Results

The mean (SD) age of participants was 40.4 (7.3) years, and 297 (56%) participants were male. The most frequent vascular risk factors were tobacco use (240 patients [45%]), hypertension (118 patients [22%]), and dyslipidemia (109 patients [20%]). PFO was detected in 177 participants (50%) who had transthoracic echocardiograms with bubble studies. Following initial ESUS, 468 participants (88%) were receiving antiplatelet therapy, and 52 (10%) received anticoagulation. The recurrent ischemic stroke and death rate was 2.19 per 100 patient-years, and the ischemic stroke recurrence rate was 1.9 per 100 patient-years. Of the recurrent strokes, 9 (64%) were ESUS, 2 (14%) were cardioembolic, and 3 (21%) were of other determined cause. AF was detected in 15 participants (2.8%; 95% CI, 1.6-4.6). In multivariate analysis, the following were associated with recurrent ischemic stroke: history of stroke or transient ischemic attack (hazard ratio, 5.3; 95% CI, 1.8-15), presence of diabetes (hazard ratio, 4.4; 95% CI, 1.5-13), and history of coronary artery disease (hazard ratio, 10; 95% CI, 4.8-22).

Conclusions and Relevance

In this large cohort of young adult patients with ESUS, there was a relatively low rate of subsequent ischemic stroke and a low frequency of new-onset AF. Most recurrent strokes also met the criteria for ESUS, suggesting the need for future studies to improve our understanding of the underlying stroke mechanism in this population.

Association of Plaque Inflammation With Stroke Recurrence in Patients With Unproven Benefit From Carotid Revascularization

BACKGROUND AND OBJECTIVES

In pooled analyses of endarterectomy trials for symptomatic carotid stenosis, several subgroups experienced no net benefit from revascularization. The validated SCAIL score includes stenosis severity and inflammation measured by Positron-Emission Tomography (PET) and improves the identification of patients with recurrent stroke compared with lumen-stenosis alone. We investigated if the SCAIL score improves the identification of recurrent stroke in subgroups with uncertain benefit from revascularization in endarterectomy trials.

METHODS

We did an individual-participant data pooled analysis of three prospective cohort studies (DUCASS, 2008-2011; BIOVASC, 2014-2018; Barcelona Plaque Study, 2015-2018). Eligible patients had a recent non-severe (modified Rankin Score≤3) anterior circulation ischaemic stroke/TIA and either: ipsilateral mild carotid stenosis (<50%); ipsilateral moderate carotid stenosis (50-69%) plus at least one of female sex, age <65 years, diabetes mellitus, TIA, or delay >14 days to revascularization; or monocular loss of vision. Patients underwent co-registered carotid ¹⁸F-FDG PET/CT angiography (≤7 days from inclusion). The primary outcome was 90-day ipsilateral ischaemic stroke. Multivariable Cox regression modelling was performed.

RESULTS

We included 135 patients. All patients started optimal modern-era medical treatment at admission and 62 (45.9%) underwent carotid revascularization (36 within the first 14 days and 26 beyond). At 90 days, 18 (13.3%) patients had experienced at least one stroke recurrence. The risk of recurrence increased progressively according to the SCAIL score (0.0% in patients scoring 0-1, 15.1% scoring 2-3 and 26.7% scoring 4-5; p=0.04). The adjusted (age, smoking, hypertension, diabetes mellitus, carotid revascularization, antiplatelets and statins) Hazard Ratio for ipsilateral recurrent stroke per 1-point SCAIL increase was 2.16 (95% CI 1.32-3.53; p=0.002). A score ≥2 had a sensitivity of 100% for recurrence.

DISCUSSION

The SCAIL score improved the identification of early recurrent stroke in subgroups that did not experience benefit in endarterectomy trials. Randomized trials are needed to test if a combined stenosis-inflammation strategy will improve selection for carotid revascularization where benefit is currently uncertain.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that in patients with recent anterior circulation ischemic stroke who do not benefit from carotid revascularization, the SCAIL score accurately distinguishes those at risk for recurrent ipsilateral ischemic stroke.

Abstract TP197: Early Direct Oral Anticoagulants Therapy After Ischemic Stroke In Patients With And Without Atrial Fibrillation:A Pooled Analysis Of Five Studies

Introduction: Early anticoagulation after acute ischemic stroke is usually avoided due to the risk of hemorrhagic transformation (HT). We aimed to assess the rate of radiological HT associated with direct oral anticoagulant (DOAC) initiation within 48 hours vs. > 48 hours in the post-stroke period.

Methods: A pooled analysis of five studies of DOAC initiation within 14 days of ischemic stroke onset was conducted. The primary endpoint was incident radiographic HT on follow-up imaging. Secondary endpoints included symptomatic HT, new parenchymal hemorrhage (PH1 or asymptomatic PH2), recurrent systemic events, systemic hemorrhagic complications, mortality within the study period, final modified Rankin Scale score. The results were reported as odds ratio (OR) with 95% confidence interval (CI).

Results: A total of 468 patients were enrolled. Median infarct volume was 1.35 (0-7.5) ml, and National Institutes of Health Stroke Scale was 1 (0-3). Incident radiographic HT was seen on follow-up scan in 29 patients. DOAC initiation within 48 hours from index event onset was not associated with incident HT (adjusted OR 0.67, [0.31 - 1.50] P =0.34). No patients developed symptomatic HT. Conversely, 25 patients developed recurrent ischemic events, 64% of which occurred within 14 days. Initiating DOAC within 48 hours of onset was not associated with a reduction in the risk of recurrent ischemic events (OR 0.47, [0.19 - 1.20] P =0.12). In contrast to HT, recurrent ischemic events were associated with poor functional outcomes (OR=6.8, [2.95 - 15.63], p<0.0001).

Conclusions: Early DOAC initiation after stroke was not associated with increased incident HT risk. Recurrent ischemic events were common and associated with poor outcomes. These data may be useful for estimating outcome rates and sample size calculations in future trials of early versus late DOAC initiation after AF-related stroke.

Radiographic Characteristics of Mild Ischemic Stroke Patients With Visible Intracranial Occlusion: The INTERRSeCT Study

BACKGROUND AND PURPOSE

Early neurological deterioration occurs in one-third of mild strokes primarily due to the presence of a relevant intracranial occlusion. We studied vascular occlusive patterns, thrombus characteristics, and recanalization rates in these patients.

METHODS

Among patients enrolled in INTERRSeCT (Identifying New Approaches to Optimize Thrombus Characterization for Predicting Early Recanalization and Reperfusion With IV Alteplase and Other Treatments Using Serial CT Angiography), a multicenter prospective study of acute ischemic strokes with a visible intracranial occlusion, we compared characteristics of mild (National Institutes of Health Stroke Scale score, ≤5) to moderate/severe strokes.

RESULTS

Among 575 patients, 12.9% had a National Institutes of Health Stroke Scale score ≤5 (median age, 70.5 [63-79]; 58% male; median National Institutes of Health Stroke Scale score, 4 [2-4]). Demographics and vascular risk factors were similar between the two groups. As compared with those with a National Institutes of Health Stroke Scale score >5, mild patients had longer symptom onset to assessment times (onset to computed tomography [240 versus 167 minutes] and computed tomography angiography [246 versus 172 minutes]), more distal occlusions (M3, anterior cerebral artery and posterior cerebral artery; 22% versus 6%), higher clot burden score (median, 9 [6-9] versus 6 [4-9]), similar favorable thrombus permeability (residual flow grades I-II, 21% versus 19%), higher collateral flow (9.1 versus 7.6), and lower intravenous alteplase treatment rates (55% versus 85%). Mild patients were more likely to recanalize (revised arterial occlusion scale score 2b/3, 45%; 49% with alteplase) compared with moderate/severe strokes (26%; 29% with alteplase). In an adjusted model for sex, alteplase, residual flow, and time between the two vessel imagings, intravenous alteplase use (odds ratio, 3.80 [95% CI, 1.11-13.00]) and residual flow grade (odds ratio, 8.70 [95% CI, 1.26-60.13]) were associated with successful recanalization among mild patients.

CONCLUSIONS

Mild strokes with visible intracranial occlusions have different vascular occlusive patterns but similar thrombus permeability compared with moderate/severe strokes. Higher thrombus permeability and alteplase use were associated with successful recanalization, although the majority do not recanalize. Randomized controlled trials are needed to assess the efficacy of new thrombolytics and endovascular therapy in this population.

Frequency and Patterns of Brain Infarction in Patients With Embolic Stroke of Undetermined Source: NAVIGATE ESUS Trial

BACKGROUND AND PURPOSE

The spectrum of brain infarction in patients with embolic stroke of undetermined source (ESUS) has not been well characterized. Our objective was to define the frequency and pattern of brain infarcts detected by magnetic resonance imaging (MRI) among patients with recent ESUS participating in a clinical trial.

METHODS

In the NAVIGATE ESUS trial (New Approach Rivaroxaban Inhibition of Factor Xa in a Global Trial Versus ASA to Prevent Embolism in Embolic Stroke of Undetermined Source), an MRI substudy was carried out at 87 sites in 15 countries. Participants underwent an MRI using a specified protocol near randomization. Images were interpreted centrally by those unaware of clinical characteristics.

RESULTS

Among the 918 substudy cohort participants, the mean age was 67 years and 60% were men with a median (interquartile range) of 64 (26-115) days between the qualifying ischemic stroke and MRI. On MRI, 855 (93%) had recent or chronic brain infarcts that were multiple in 646 (70%) and involved multiple arterial territories in 62% (401/646). Multiple brain infarcts were present in 68% (510/755) of those without a history of stroke or transient ischemic attack before the qualifying ESUS. Prior stroke/transient ischemic attack (P<0.001), modified Rankin Scale score >0 (P<0.001), and current tobacco use (P=0.01) were associated with multiple infarcts. Topographically, large and/or cortical infarcts were present in 89% (757/855) of patients with infarcts, while in 11% (98/855) infarcts were exclusively small and subcortical. Among those with multiple large and/or cortical infarcts, 57% (251/437) had one or more involving a different vascular territory from the qualifying ESUS.

CONCLUSIONS

Most patients with ESUS, including those without prior clinical stroke or transient ischemic attack, had multiple large and/or cortical brain infarcts detected by MRI, reflecting a substantial burden of clinical stroke and covert brain infarction. Infarcts most frequently involved multiple vascular territories.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02313909.

Effect of Implantable vs Prolonged External Electrocardiographic Monitoring on Atrial Fibrillation Detection in Patients With Ischemic Stroke: The PER DIEM Randomized Clinical Trial

IMPORTANCE

The relative rates of detection of atrial fibrillation (AF) or atrial flutter from evaluating patients with prolonged electrocardiographic monitoring with an external loop recorder or implantable loop recorder after an ischemic stroke are unknown.

OBJECTIVE

To determine, in patients with a recent ischemic stroke, whether 12 months of implantable loop recorder monitoring detects more occurrences of AF compared with conventional external loop recorder monitoring for 30 days.

DESIGN, SETTING, AND PARTICIPANTS

Investigator-initiated, open-label, randomized clinical trial conducted at 2 university hospitals and 1 community hospital in Alberta, Canada, including 300 patients within 6 months of ischemic stroke and without known AF from May 2015 through November 2017; final follow-up was in December 2018.

INTERVENTIONS

Participants were randomly assigned 1:1 to prolonged electrocardiographic monitoring with either an implantable loop recorder (n = 150) or an external loop recorder (n = 150) with follow-up visits at 30 days, 6 months, and 12 months.

MAIN OUTCOMES AND MEASURES

The primary outcome was the development of definite AF or highly probable AF (adjudicated new AF lasting ≥2 minutes within 12 months of randomization). There were 8 prespecified secondary outcomes including time to event analysis of new AF, recurrent ischemic stroke, intracerebral hemorrhage, death, and device-related serious adverse events within 12 months.

RESULTS

Among the 300 patients who were randomized (median age, 64.1 years [interquartile range, 56.1 to 73.7 years]; 121 were women [40.3%]; and 66.3% had a stroke of undetermined etiology with a median CHA2DS2-VASc [congestive heart failure, hypertension, age ≥75 years, diabetes, stroke or transient ischemic attack, vascular disease, age 65 to 74 years, sex category] score of 4 [interquartile range, 3 to 5]), 273 (91.0%) completed cardiac monitoring lasting 24 hours or longer and 259 (86.3%) completed both the assigned monitoring and 12-month follow-up visit. The primary outcome was observed in 15.3% (23/150) of patients in the implantable loop recorder group and 4.7% (7/150) of patients in the external loop recorder group (between-group difference, 10.7% [95% CI, 4.0% to 17.3%]; risk ratio, 3.29 [95% CI, 1.45 to 7.42]; P = .003). Of the 8 specified secondary outcomes, 6 were not significantly different. There were 5 patients (3.3%) in the implantable loop recorder group who had recurrent ischemic stroke vs 8 patients (5.3%) in the external loop recorder group (between-group difference, -2.0% [95% CI, -6.6% to 2.6%]), 1 (0.7%) vs 1 (0.7%), respectively, who had intracerebral hemorrhage (between-group difference, 0% [95% CI, -1.8% to 1.8%]), 3 (2.0%) vs 3 (2.0%) who died (between-group difference, 0% [95% CI, -3.2% to 3.2%]), and 1 (0.7%) vs 0 (0%) who had device-related serious adverse events.

CONCLUSIONS AND RELEVANCE

Among patients with ischemic stroke and no prior evidence of AF, implantable electrocardiographic monitoring for 12 months, compared with prolonged external monitoring for 30 days, resulted in a significantly greater proportion of patients with AF detected over 12 months. Further research is needed to compare clinical outcomes associated with these monitoring strategies and relative cost-effectiveness.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02428140.

A Detailed Analysis of Infarct Patterns and Volumes at 24-hour Noncontrast CT and Diffusion-weighted MRI in Acute Ischemic Stroke Due to Large Vessel Occlusion: Results from the ESCAPE-NA1 Trial

Background The effect of infarct pattern on functional outcome in acute ischemic stroke is incompletely understood. Purpose To investigate the association of qualitative and quantitative infarct variables at 24-hour follow-up noncontrast CT and diffusion-weighted MRI with 90-day clinical outcome. Materials and Methods The Safety and Efficacy of Nerinetide in Subjects Undergoing Endovascular Thrombectomy for Stroke, or ESCAPE-NA1, randomized controlled trial enrolled patients with large-vessel-occlusion stroke undergoing mechanical thrombectomy from March 1, 2017, to August 12, 2019. In this post hoc analysis of the trial, qualitative infarct variables (predominantly gray [vs gray and white] matter involvement, corticospinal tract involvement, infarct structure [scattered vs territorial]) and total infarct volume were assessed at 24-hour follow-up noncontrast CT or diffusion-weighted MRI. White and gray matter infarct volumes were assessed in patients by using follow-up diffusion-weighted MRI. Infarct variables were compared between patients with and those without good outcome, defined as a modified Rankin Scale score of 0-2 at 90 days. The association of infarct variables with good outcome was determined with use of multivariable logistic regression. Separate regression models were used to report effect size estimates with adjustment for total infarct volume. Results Qualitative infarct variables were assessed in 1026 patients (mean age ± standard deviation, 69 years ± 13; 522 men) and quantitative infarct variables were assessed in a subgroup of 358 of 1026 patients (mean age, 67 years ± 13; 190 women). Patients with gray and white matter involvement (odds ratio [OR] after multivariable adjustment, 0.19; 95% CI: 0.14, 0.25; P < .001), corticospinal tract involvement (OR after multivariable adjustment, 0.06; 95% CI: 0.04, 0.10; P < .001), and territorial infarcts (OR after multivariable adjustment, 0.22; 95% CI: 0.14, 0.32; P < .001) were less likely to achieve good outcome, independent of total infarct volume. Conclusion Infarct confinement to the gray matter, corticospinal tract sparing, and scattered infarct structure at 24-hour noncontrast CT and diffusion-weighted MRI were highly predictive of good 90-day clinical outcome, independent of total infarct volume. Clinical trial registration no. NCT02930018 © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Mossa-Basha in this issue.

Development of imaging-based risk scores for prediction of intracranial haemorrhage and ischaemic stroke in patients taking antithrombotic therapy after ischaemic stroke or transient ischaemic attack: a pooled analysis of individual patient data from cohort studies

BACKGROUND

Balancing the risks of recurrent ischaemic stroke and intracranial haemorrhage is important for patients treated with antithrombotic therapy after ischaemic stroke or transient ischaemic attack. However, existing predictive models offer insufficient performance, particularly for assessing the risk of intracranial haemorrhage. We aimed to develop new risk scores incorporating clinical variables and cerebral microbleeds, an MRI biomarker of intracranial haemorrhage and ischaemic stroke risk.

METHODS

We did a pooled analysis of individual-patient data from the Microbleeds International Collaborative Network (MICON), which includes 38 hospital-based prospective cohort studies from 18 countries. All studies recruited participants with previous ischaemic stroke or transient ischaemic attack, acquired baseline MRI allowing quantification of cerebral microbleeds, and followed-up participants for ischaemic stroke and intracranial haemorrhage. Participants not taking antithrombotic drugs were excluded. We developed Cox regression models to predict the 5-year risks of intracranial haemorrhage and ischaemic stroke, selecting candidate predictors on biological relevance and simplifying models using backward elimination. We derived integer risk scores for clinical use. We assessed model performance in internal validation, adjusted for optimism using bootstrapping. The study is registered on PROSPERO, CRD42016036602.

FINDINGS

The included studies recruited participants between Aug 28, 2001, and Feb 4, 2018. 15 766 participants had follow-up for intracranial haemorrhage, and 15 784 for ischaemic stroke. Over a median follow-up of 2 years, 184 intracranial haemorrhages and 1048 ischaemic strokes were reported. The risk models we developed included cerebral microbleed burden and simple clinical variables. Optimism-adjusted c indices were 0·73 (95% CI 0·69-0·77) with a calibration slope of 0·94 (0·81-1·06) for the intracranial haemorrhage model and 0·63 (0·62-0·65) with a calibration slope of 0·97 (0·87-1·07) for the ischaemic stroke model. There was good agreement between predicted and observed risk for both models.

INTERPRETATION

The MICON risk scores, incorporating clinical variables and cerebral microbleeds, offer predictive value for the long-term risks of intracranial haemorrhage and ischaemic stroke in patients prescribed antithrombotic therapy for secondary stroke prevention; external validation is warranted.

FUNDING

British Heart Foundation and Stroke Association.

Rate and Prognosis of Brain Ischemia in Patients With Lower-Risk Transient or Persistent Minor Neurologic Events

Importance

Early treatment of patients with transient ischemic attack (TIA) reduces the risk of stroke. However, many patients present with symptoms that have an uncertain diagnosis. Patients with motor, speech, or prolonged symptoms are at the highest risk for recurrent stroke and the most likely to undergo comprehensive investigations. Lower-risk patients are much more likely to be cursorily investigated.

Objective

To establish the frequency of acute infarct defined by diffusion restriction detected on diffusion-weighted imaging (DWI) magnetic resonance imaging (MRI) scan (DWI positive).

Design, Setting, and Participants

The Diagnosis of Uncertain-Origin Benign Transient Neurological Symptoms (DOUBT) study was a prospective, observational, international, multicenter cohort study of 1028 patients with low-risk transient or minor symptoms referred to neurology within 8 days of symptom onset. Patients were enrolled between June 1, 2010, and October 31, 2016. Included patients were 40 years or older and had experienced nonmotor or nonspeech minor focal neurologic events of any duration or motor or speech symptoms of short duration (≤5 minutes), with no previous stroke.

Exposures

Patients underwent a detailed neurologic assessment prior to undergoing a brain MRI within 8 days of symptom onset.

Main Outcomes and Measures

The primary outcome was restricted diffusion on a brain MRI scan (acute stroke).

Results

A total of 1028 patients (522 women and 506 men; mean [SD] age, 63.0 [11.6] years) were enrolled. A total of 139 patients (13.5%) had an acute stroke as defined by diffusion restriction detected on MRI scans (DWI positive). The final diagnosis was revised in 308 patients (30.0%) after undergoing brain MRI. There were 7 (0.7%) recurrent strokes at 1 year. A DWI-positive brain MRI scan was associated with an increased risk of recurrent stroke (relative risk, 6.4; 95% CI, 2.4-16.8) at 1 year. Absence of a DWI-positive lesion on a brain MRI scan had a 99.8% negative predictive value for recurrent stroke. Factors associated with MRI evidence of stroke in multivariable modeling were older age (odds ratio [OR], 1.02; 95% CI, 1.00-1.04), male sex (OR, 2.03; 95% CI, 1.39-2.96), motor or speech symptoms (OR, 2.12; 95% CI, 1.37-3.29), ongoing symptoms at assessment (OR, 1.97; 95% CI, 1.29-3.02), no prior identical symptomatic event (OR, 1.87; 95% CI, 1.12-3.11), and abnormal results of initial neurologic examination (OR, 1.71; 95% CI, 1.11-2.65).

Conclusions and Relevance

This study suggested that patients with transient ischemic attack and symptoms traditionally considered low risk carry a substantive risk of acute stroke as defined by diffusion restriction (DWI positive) on a brain MRI scan. Early MRI is required to make a definitive diagnosis.

Sex Differences in Diagnosis and Diagnostic Revision of Suspected Minor Cerebral Ischemic Events

OBJECTIVE

To describe sex differences in the presentation, diagnosis, and revision of diagnosis after early brain MRI in patients who present with acute transient or minor neurologic events.

METHODS

We performed a secondary analysis of a prospective multicenter cohort study of patients referred to neurology between 2010 and 2016 with a possible cerebrovascular event and evaluated with brain MRI within 8 days of symptom onset. Investigators documented the characteristics of the event, initial diagnosis, and final diagnosis. We used multivariable logistic regression analyses to evaluate the association between sex and outcomes.

RESULTS

Among 1,028 patients (51% women, median age 63 years), more women than men reported headaches and fewer reported chest pain, but there were no sex differences in other accompanying symptoms. Women were more likely than men to be initially diagnosed with stroke mimic (54% of women vs 42% of men, adjusted odds ratio (OR) 1.60, 95% confidence interval [CI] 1.24-2.07), and women were overall less likely to have ischemia on MRI (10% vs 17%, OR 0.52, 95% CI 0.36-0.76). Among 496 patients initially diagnosed with mimic, women were less likely than men to have their diagnosis revised to minor stroke or TIA (13% vs 20%, OR 0.53, 95% CI 0.32-0.88) but were equally likely to have acute ischemia on MRI (5% vs 8%, OR 0.56, 95% CI 0.26-1.21).

CONCLUSIONS

Stroke mimic was more frequently diagnosed in women than men, but diagnostic revisions were common in both. Early brain MRI is a useful addition to clinical evaluation in diagnosing transient or minor neurologic events.

White matter tract microstructure and cognitive performance after transient ischemic attack

BACKGROUND AND PURPOSE

Patients with transient ischemic attack (TIA) show evidence of cognitive impairment but the reason is not clear. Measurement of microstructural changes in white matter (WM) using diffusion tensor imaging (DTI) may be a useful outcome measure. We report WM changes using DTI and the relationship with neuropsychological performance in a cohort of transient ischemic attack (TIA) and non-TIA subjects.

METHODS

Ninety-five TIA subjects and 51 non-TIA subjects were assessed using DTI and neuropsychological batteries. Fractional anisotropy (FA) and mean diffusivity (MD) maps were generated and measurements were collected from WM tracts. Adjusted mixed effects regression modelled the relationship between groups and DTI metrics.

RESULTS

Transient ischemic attack subjects had a mean age of 67.9 ± 9.4 years, and non-TIA subjects had a mean age 64.9 ± 9.9 years. The TIA group exhibited higher MD values in the fornix (0.36 units, P < 0.001) and lower FA in the superior longitudinal fasciculus (SLF) (-0.29 units, P = 0.001), genu (-0.22 units, P = 0.016), and uncinate fasciculus (UF) (-0.26 units, P = 0.004). Compared to non-TIA subjects, subjects with TIA scored lower on the Addenbrooke's Cognitive Assessment-Revised (median score 95 vs 91, P = 0.01) but showed no differences in scores on the Montreal Cognitive Assessment (median 27 vs 26) or the Mini-Mental State Examination (median 30). TIA subjects had lower scores in memory (median 44 vs 52, P < 0.01) and processing speed (median 45 vs 62, P < 0.01) but not executive function, when compared to non-TIA subjects. Lower FA and higher MD in the fornix, SLF, and UF were associated with poorer performance on tests of visual memory and executive function but not verbal memory. Lower FA in the UF and fornix were related to higher timed scores on the TMT-B (P < 0.01), and higher SLF MD was related to higher scores on TMT-B (P < 0.01), confirming worse executive performance in the TIA group.

CONCLUSIONS

DTI scans may be useful for detecting microstructural disease in TIA subjects before cognitive symptoms develop. DTI parameters, white matter hyperintensities, and vascular risk factors underly some of the altered neuropsychological measures in TIA subjects.

An International Report on the Adaptations of Rapid Transient Ischaemic Attack Pathways During the COVID-19 Pandemic

Background

This report aims to describe changes that centres providing transient ischaemic attack (TIA) pathway services have made to stay operational in response to the SARS-CoV-2 pandemic.

Methods

An international cross-sectional description of the adaptions of TIA pathways between 30^th March and 6^th May 2020. Experience was reported from 18 centres with rapid TIA pathways in seven countries (Australia, France, UK, Canada, USA, New Zealand, Italy, Canada) from three continents.

Results

All pathways remained active (n = 18). Sixteen (89%) had TIA clinics. Six of these clinics (38%) continued to provide in-person assessment while the majority (63%) used telehealth exclusively. Of these, three reported PPE use and three did not. Five centres with clinics (31%) had adopted a different vascular imaging strategy.

Conclusion

The COVID pandemic has led TIA clinics around the world to adapt and move to the use of telemedicine for outpatient clinic review and modified investigation pathways. Despite the pandemic, all have remained operational.

Recurrent Stroke With Rivaroxaban Compared With Aspirin According to Predictors of Atrial Fibrillation: Secondary Analysis of the NAVIGATE ESUS Randomized Clinical Trial

Importance

The NAVIGATE ESUS randomized clinical trial found that 15 mg of rivaroxaban per day does not reduce stroke compared with aspirin in patients with embolic stroke of undetermined source (ESUS); however, it substantially reduces stroke risk in patients with atrial fibrillation (AF).

Objective

To analyze whether rivaroxaban is associated with a reduction of recurrent stroke among patients with ESUS who have an increased risk of AF.

Design, Setting, and Participants

Participants were stratified by predictors of AF, including left atrial diameter, frequency of premature atrial contractions, and HAVOC score, a validated scheme using clinical features. Treatment interactions with these predictors were assessed. Participants were enrolled between December 2014 and September 2017, and analysis began March 2018.

Intervention

Rivaroxaban treatment vs aspirin.

Main Outcomes and Measures

Risk of ischemic stroke.

Results

Among 7112 patients with a mean (SD) age of 67 (9.8) years, the mean (SD) HAVOC score was 2.6 (1.8), the mean (SD) left atrial diameter was 3.8 (1.4) cm (n = 4022), and the median (interquartile range) daily frequency of premature atrial contractions was 48 (13-222). Detection of AF during follow-up increased for each tertile of HAVOC score: 2.3% (score, 0-2), 3.0% (score, 3), and 5.8% (score, >3); however, neither tertiles of the HAVOC score nor premature atrial contractions frequency impacted the association of rivaroxaban with recurrent ischemic stroke (P for interaction = .67 and .96, respectively). Atrial fibrillation annual incidence increased for each tertile of left atrial diameter (2.0%, 3.6%, and 5.2%) and for each tertile of premature atrial contractions frequency (1.3%, 2.9%, and 7.0%). Among the predefined subgroup of patients with a left atrial diameter of more than 4.6 cm (9% of overall population), the risk of ischemic stroke was lower among the rivaroxaban group (1.7% per year) compared with the aspirin group (6.5% per year) (hazard ratio, 0.26; 95% CI, 0.07-0.94; P for interaction = .02).

Conclusions and Relevance

The HAVOC score, left atrial diameter, and premature atrial contraction frequency predicted subsequent clinical AF. Rivaroxaban was associated with a reduced risk of recurrent stroke among patients with ESUS and moderate or severe left atrial enlargement; however, this needs to be independently confirmed before influencing clinical practice.

Regional Variation in Transient Ischemic Attack and Minor Stroke in Alberta Emergency Departments

Background and Purpose—

Multiple studies have shown the 90-day risk of stroke following an emergency department (ED) diagnosis of transient ischemic attack (TIA) or minor stroke is significant, with the greatest risk of recurrence being within the first 24 to 48 hours following initial symptom onset. This study explored regional differences in ED disposition, neuroimaging, and subsequent 90-day stroke risk of patients diagnosed with TIA or minor stroke in Alberta.

Methods—

We used administrative databases to identify ED visits, neuroimaging, and 90-day return visits for TIA or minor stroke in Alberta from April 2011 to March 2016 among adults ≥20 years of age and stratified them based on regions of presentation (Edmonton, Calgary, or nonmajor urban).

Results—

During the 5-year study period, 22 421 patients had index ED visits for TIA or minor stroke. All 3 regions had a similar number of ED visits for TIA/minor stroke; however, on index ED visit, Calgary had a higher proportion of computed tomographic angiography imaging (48.8%; P <0.0001) compared with Edmonton (6.7%) and nonmajor urban region (5.7%) and higher proportion of discharged patients (83%; P <0.0001) compared with Edmonton (77.7%) and nonmajor urban region (73.5%). The risk of admission for stroke within 90 days of discharge after index ED visit for TIA/minor stroke in Calgary (3.4%) was lower than Edmonton (4.5%) and the nonmajor urban region (4.6%; P =0.002).

Conclusions—

This study demonstrates regional variation in computed tomographic angiography for neurovascular imaging of patients presenting to the ED for TIA/minor stroke and a possible association with frequency of index visit admission and 90-day readmission for the same problem.

Prevalence of Ipsilateral Nonstenotic Carotid Plaques on Computed Tomography Angiography in Embolic Stroke of Undetermined Source

Background and Purpose- Embolic stroke of undetermined source (ESUS) constitutes a large proportion of acute ischemic stroke. It is crucial to identify possible stroke etiologies in this patient subgroup to individually tailor secondary stroke prevention strategies. This study aimed to assess the prevalence of carotid plaques causing <50% stenosis in ESUS patients on computed tomography angiography and the association of these plaques with ipsilateral strokes. Methods- Patients from INTERRSeCT-a multicenter prospective study of patients with acute ischemic stroke-were included in this study if their stroke etiology was not large artery atherosclerosis (>50% stenosis), and neck computed tomography angiography was obtained. Degree of stenosis (<30% versus 30%-50%), maximum plaque thickness, degree of plaque calcification (<50% versus ≥50%), plaque irregularity, ulceration, hypodensity, carotid web, and focal vessel outpouching were assessed for both carotid arteries on computed tomography angiography. Prevalence of carotid plaques with <50% stenosis (nonstenotic plaques), ipsilateral and contralateral to the stroke, in ESUS patients was determined and compared with non-ESUS patients. Features of these plaques with versus without ipsilateral stroke in ESUS patients were compared. Uni- and multivariable logistic regression was performed to determine associations between nonstenotic carotid plaque, plaque characteristics, and ipsilateral stroke in ESUS patients. Results- Four hundred forty-six patients were included in the study (median age, 73 years; 218 men), 138 of which were ESUS patients (median age, 70 years; 61 men). Nonstenotic carotid plaques (with <50% stenosis) were present in 54 of 138 (39.1%) ESUS patients. Twelve (8.7%) patients had bilateral carotid plaques. Forty (60.6%) of these plaques were ipsilateral and 26 (39.4%) contralateral to the side of the stroke (P=0.004). Nonstenotic carotid plaques were significantly associated with ipsilateral strokes (adjusted odds ratio, 1.83 [95% CI, 1.05-3.18]). Conclusions- In patients with ESUS, nonstenotic carotid plaques were significantly more common on the side of the ischemic stroke, suggesting that these plaques could be a potential stroke etiology in patients in whom the ischemic stroke is classified currently as ESUS.

Efficacy and safety of nerinetide for the treatment of acute ischaemic stroke (ESCAPE-NA1): a multicentre, double-blind, randomised controlled trial

BACKGROUND

Nerinetide, an eicosapeptide that interferes with post-synaptic density protein 95, is a neuroprotectant that is effective in preclinical stroke models of ischaemia-reperfusion. In this trial, we assessed the efficacy and safety of nerinetide in human ischaemia-reperfusion that occurs with rapid endovascular thrombectomy in patients who had an acute ischaemic stroke.

METHODS

For this multicentre, double-blind, randomised, placebo-controlled study done in 48 acute care hospitals in eight countries, we enrolled patients with acute ischaemic stroke due to large vessel occlusion within a 12 h treatment window. Eligible patients were aged 18 years or older with a disabling ischaemic stroke at the time of randomisation, had been functioning independently in the community before the stroke, had an Alberta Stroke Program Early CT Score (ASPECTS) greater than 4, and vascular imaging showing moderate-to-good collateral filling, as determined by multiphase CT angiography. Patients were randomly assigned (1:1) to receive intravenous nerinetide in a single dose of 2·6 mg/kg, up to a maximum dose of 270 mg, on the basis of estimated or actual weight (if known) or saline placebo by use of a real-time, dynamic, internet-based, stratified randomised minimisation procedure. Patients were stratified by intravenous alteplase treatment and declared endovascular device choice. All trial personnel and patients were masked to sequence and treatment allocation. All patients underwent endovascular thrombectomy and received alteplase in usual care when indicated. The primary outcome was a favourable functional outcome 90 days after randomisation, defined as a modified Rankin Scale (mRS) score of 0-2. Secondary outcomes were measures of neurological disability, functional independence in activities of daily living, excellent functional outcome (mRS 0-1), and mortality. The analysis was done in the intention-to-treat population and adjusted for age, sex, baseline National Institutes of Health Stroke Scale score, ASPECTS, occlusion location, site, alteplase use, and declared first device. The safety population included all patients who received any amount of study drug. This trial is registered with ClinicalTrials.gov, NCT02930018.

FINDINGS

Between March 1, 2017, and Aug 12, 2019, 1105 patients were randomly assigned to receive nerinetide (n=549) or placebo (n=556). 337 (61·4%) of 549 patients with nerinetide and 329 (59·2%) of 556 with placebo achieved an mRS score of 0-2 at 90 days (adjusted risk ratio 1·04, 95% CI 0·96-1·14; p=0·35). Secondary outcomes were similar between groups. We observed evidence of treatment effect modification resulting in inhibition of treatment effect in patients receiving alteplase. Serious adverse events occurred equally between groups.

INTERPRETATION

Nerinetide did not improve the proportion of patients achieving good clinical outcomes after endovascular thrombectomy compared with patients receiving placebo.

FUNDING

Canadian Institutes for Health Research, Alberta Innovates, and NoNO.

A Risk Score Including Carotid Plaque Inflammation and Stenosis Severity Improves Identification of Recurrent Stroke

Background and Purpose—

In randomized trials of symptomatic carotid endarterectomy, only modest benefit occurred in patients with moderate stenosis and important subgroups experienced no benefit. Carotid plaque 18 F-fluorodeoxyglucose uptake on positron emission tomography, reflecting inflammation, independently predicts recurrent stroke. We investigated if a risk score combining stenosis and plaque 18 F-fluorodeoxyglucose would improve the identification of early recurrent stroke.

Methods—

We derived the score in a prospective cohort study of recent (<30 days) non-severe (modified Rankin Scale score ≤3) stroke/transient ischemic attack. We derived the SCAIL (symptomatic carotid atheroma inflammation lumen-stenosis) score (range, 0–5) including 18 F-fluorodeoxyglucose standardized uptake values (SUV max <2 g/mL, 0 points; SUV max 2–2.99 g/mL, 1 point; SUV max 3–3.99 g/mL, 2 points; SUV max ≥4 g/mL, 3 points) and stenosis (<50%, 0 points; 50%–69%, 1 point; ≥70%, 2 points). We validated the score in an independent pooled cohort of 2 studies. In the pooled cohorts, we investigated the SCAIL score to discriminate recurrent stroke after the index stroke/transient ischemic attack, after positron emission tomography-imaging, and in mild or moderate stenosis.

Results—

In the derivation cohort (109 patients), recurrent stroke risk increased with increasing SCAIL score ( P =0.002, C statistic 0.71 [95% CI, 0.56–0.86]). The adjusted (age, sex, smoking, hypertension, diabetes mellitus, antiplatelets, and statins) hazard ratio per 1-point SCAIL increase was 2.4 (95% CI, 1.2–4.5, P =0.01). Findings were confirmed in the validation cohort (87 patients, adjusted hazard ratio, 2.9 [95% CI, 1.9–5], P <0.001; C statistic 0.77 [95% CI, 0.67–0.87]). The SCAIL score independently predicted recurrent stroke after positron emission tomography-imaging (adjusted hazard ratio, 4.52 [95% CI, 1.58–12.93], P =0.005). Compared with stenosis severity (C statistic, 0.63 [95% CI, 0.46–0.80]), prediction of post-positron emission tomography stroke recurrence was improved with the SCAIL score (C statistic, 0.82 [95% CI, 0.66–0.97], P =0.04). Findings were confirmed in mild or moderate stenosis (adjusted hazard ratio, 2.74 [95% CI, 1.39–5.39], P =0.004).

Conclusions—

The SCAIL score improved the identification of early recurrent stroke. Randomized trials are needed to test if a combined stenosis-inflammation strategy improves selection for carotid revascularization where benefit is currently uncertain.

Dabigatran Treatment of Acute Noncardioembolic Ischemic Stroke

Background and Purpose- Patients with transient ischemic attack (TIA) and minor ischemic stroke are at risk for early recurrent cerebral ischemia. Anticoagulants are associated with reduced recurrence but also increased hemorrhagic transformation (HT). The safety of the novel oral anticoagulant dabigatran in acute stroke has not been evaluated. Methods- DATAS II (Dabigatran Treatment of Acute Stroke II) was a phase II prospective, randomized open label, blinded end point trial. Patients with noncardioembolic stroke/transient ischemic attack (National Institutes of Health Stroke Scale score, ≤9; infarct volume, ≤25 mL) were randomized to dabigatran or aspirin. Magnetic resonance imaging was performed before randomization and repeated at day 30. Imaging end points were ascertained centrally by readers blinded to treatment. The primary end point was symptomatic HT within 37 days of randomization. Results- A total of 305 patients, mean age 66.59±13.21 years, were randomized to dabigatran or aspirin a mean of 42.00±17.31 hours after symptom onset. The qualifying event was a transient ischemic attack in 21%, and ischemic stroke in 79% of patients. Median National Institutes of Health Stroke Scale (interquartile range) was 1 (0-2), and mean infarct volume 3.2±6.5 mL. No symptomatic HT occurred. Asymptomatic petechial HT developed in 11/142 (7.8%) of dabigatran-assigned patients and 5/142 (3.5%) of aspirin-assigned patients (relative risk, 2.301 [95% CI, 0.778-6.802]). Baseline infarct volume predicted incident HT (odds ratio, 1.07 [95% CI, 1.03-1.12]; P=0.0026). Incident covert infarcts on day 30 imaging occurred in 9/142 (6.3%) of dabigatran-assigned and 14/142 (9.8%) of aspirin-assigned patients (relative risk, 0.62 [95% CI, 0.26, 1.48]). Conclusions- Dabigatran was associated with a risk of HT similar to aspirin in acute minor noncardioembolic ischemic stroke/transient ischemic attack. Registration- URL: https://www.clinicaltrials.gov; Unique identifier: NCT02295826.

Disability After Minor Stroke and Transient Ischemic Attack in the POINT Trial

Background and Purpose- While combination aspirin and clopidogrel reduces recurrent stroke compared with aspirin alone in patients with transient ischemic attack (TIA) or minor stroke, the effect on disability is uncertain. Methods- The POINT trial (Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke) randomized patients with TIA or minor stroke (National Institutes of Health Stroke Scale score ≤3) within 12 hours of onset to dual antiplatelet therapy (DAPT) with aspirin plus clopidogrel versus aspirin alone. The primary outcome measure was a composite of stroke, myocardial infarction, or vascular death. We performed a post hoc exploratory analysis to examine the effect of treatment on overall disability (defined as modified Rankin Scale score >1) at 90 days, as well as disability ascribed by the local investigator to index or recurrent stroke. We also evaluated predictors of disability. Results- At 90 days, 188 of 1964 (9.6%) of patients enrolled with TIA and 471 of 2586 (18.2%) of those enrolled with stroke were disabled. Overall disability was similar between patients assigned DAPT versus aspirin alone (14.7% versus 14.3%; odds ratio, 0.97 [95% CI, 0.82-1.14]; P=0.69). However, there were numerically fewer patients with disability in conjunction with a primary outcome event in the DAPT arm (3.0% versus 4.0%; odds ratio, 0.73 [95% CI, 0.53-1.01]; P=0.06) and significantly fewer patients in the DAPT arm with disability attributed by the investigators to either the index event or recurrent stroke (5.9% versus 7.4%; odds ratio, 0.78 [95% CI, 0.62-0.99]; P=0.04). Notably, disability attributed to the index event accounted for the majority of this difference (4.5% versus 6.0%; odds ratio, 0.74 [95% CI, 0.57-0.96]; P=0.02). In multivariate analysis, age, subsequent ischemic stroke, serious adverse events, and major bleeding were significantly associated with disability in TIA; for those with stroke, female sex, hypertension, or diabetes mellitus, National Institutes of Health Stroke Scale score, recurrent ischemic stroke, subsequent myocardial infarction, and serious adverse events were associated with disability. Conclusions- In addition to reducing recurrent stroke in patients with acute minor stroke and TIA, DAPT might reduce stroke-related disability. Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT00991029.