Comparing Low- or Standard-Dose Alteplase in Endovascular Thrombectomy: Insights From a Nationwide Registry.

BACKGROUND: Timely intravenous thrombolysis and endovascular thrombectomy are the standard reperfusion treatments for large vessel occlusion stroke. Currently, it is unknown whether a low-dose thrombolytic agent (0.6 mg/kg alteplase) can offer similar efficacy to the standard dose (0.9 mg/kg alteplase). METHODS: We enrolled consecutive patients in the multicenter Taiwan Registry of Endovascular Thrombectomy for Acute Ischemic Stroke who had received combined thrombolysis (within 4.5 hours of onset) and thrombectomy treatment from January 2019 to April 2023. The choice of low- or standard-dose alteplase was based on the physician's discretion. The outcomes included successful reperfusion (modified Thrombolysis in Cerebral Infarction score, 2b-3), symptomatic intracerebral hemorrhage, 90-day modified Rankin Scale score, and 90-day mortality. The outcomes between the 2 groups were compared using multivariable logistic regression and inverse probability of treatment weighting-adjusted analysis. RESULTS: Among the 2242 patients in the Taiwan Registry of Endovascular Thrombectomy for Acute Ischemic Stroke, 734 (33%) received intravenous alteplase. Patients in the low-dose group (n=360) were older, had more women, more atrial fibrillation, and longer onset-to-needle time compared with the standard-dose group (n=374). In comparison to low-dose alteplase, standard-dose alteplase was associated with a lower rate of successful reperfusion (81% versus 87%; adjusted odds ratio, 0.63 [95% CI, 0.40-0.98]), a numerically higher incidence of symptomatic intracerebral hemorrhage (6.7% versus 3.9%; adjusted odds ratio, 1.81 [95% CI, 0.88-3.69]), but better 90-day modified Rankin Scale score (functional independence [modified Rankin Scale score, 0-2], 47% versus 31%; adjusted odds ratio, 1.91 [95% CI, 1.28-2.86]), and a numerically lower mortality rate (9% versus 15%; adjusted odds ratio, 0.73 [95% CI, 0.43-1.25]) after adjusting for covariates. Similar results were observed in the inverse probability of treatment weighting-adjusted models. The results were consistent across predefined subgroups and age strata. CONCLUSIONS: Despite the lower rate of successful reperfusion and higher risk of symptomatic intracerebral hemorrhage with standard-dose alteplase, standard-dose alteplase was associated with a better functional outcome in patients receiving combined thrombolysis and thrombectomy.

Monogenic Causes in Familial Stroke Across Intracerebral Hemorrhage and Ischemic Stroke Subtypes Identified by Whole-Exome Sequencing.

Whole exome sequencing (WES) has been used to detect rare causative variants in neurological diseases. However, the efficacy of WES in genetic diagnosis of clinically heterogeneous familial stroke remains inconclusive. We prospectively searched for disease-causing variants in unrelated probands with defined familial stroke by candidate gene/hotspot screening and/or WES, depending on stroke subtypes and neuroimaging features at a referral center. The clinical significance of each variant was determined according to the American College of Medical Genetics guidelines. Among 161 probands (mean age at onset 53.2 ± 13.7 years; male 63.4%), 33 participants (20.5%) had been identified with 19 pathogenic/likely pathogenic variants (PVs; WES applied 152/161 = 94.4%). Across subtypes, the highest hit rate (HR) was intracerebral hemorrhage (ICH, 7/18 = 38.9%), particularly with the etiological subtype of structural vasculopathy (4/4 = 100%, PVs in ENG, KRIT1, PKD1, RNF213); followed by ischemic small vessel disease (SVD, 15/48 = 31.3%; PVs in NOTCH3, HTRA1, HBB). In contrast, large artery atherosclerosis (LAA, 4/44 = 9.1%) and cardioembolism (0/11 = 0%) had the lowest HR. NOTCH3 was the most common causative gene (16/161 = 9.9%), presenting with multiple subtypes of SVD (n = 13), ICH (n = 2), or LAA (n = 1). Importantly, we disclosed two previously unreported PVs, KRIT1 p.E379* in a familial cerebral cavernous malformation, and F2 p.F382L in a familial cerebral venous sinus thrombosis. The contribution of monogenic etiologies was particularly high in familial ICH and SVD subtypes in our Taiwanese cohort. Utilizing subtype-guided hotspot screening and/or subsequent WES, we unraveled monogenic causes in 20.5% familial stroke probands, including 1.2% novel PVs. Genetic diagnosis may enable early diagnosis, management and lifestyle modification. Among 161 familial stroke probands, 33 (20.5%) had been identified pathogenic or likely pathogenic monogenic variants related to stroke. The positive hit rate among all subtypes was high in intracerebral hemorrhage (ICH) and ischemic small vessel disease (SVD). Notably, two previously unreported variants, KRIT1 p.E379* in a familial cerebral cavernous malformation and F2 p.F382L in familial cerebral venous sinus thrombosis, were disclosed. CVT cerebral venous thrombosis; HTN Hypertensive subtype; LAA large artery atherosclerosis; SV structural vasculopathy; U Undetermined.

The 2020 Taiwan Stroke Society guidelines for blood pressure control at the acute stage of ischemic stroke.

The 2020 Taiwan Stroke Society (TSS) guidelines for blood pressure (BP) control related to ischemic stroke update the 2015 TSS BP guidelines. The early management of acute ischemic stroke has evolved rapidly in the previous two decades. Since the publication of the previous version of the TSS BP guidelines, many studies have addressed BP management in ischemic stroke. Particularly, several successful endovascular thrombectomy (EVT) trials published in 2015 led to a new era of acute treatment for ischemic stroke. With the ever-increasing use of EVT, evidence-based guidelines for ideal BP management during and after EVT are urgently needed. Consequently, the 2020 guidelines are updating and providing recommendations on BP control for the treatment and prevention of ischemic stroke based on new evidence. The present study encompasses the most important chapter of the 2020 Taiwan BP guidelines: BP control at the acute stage of ischemic stroke. We incorporated the most updated evidence regarding BP control at the acute stage of ischemic stroke in patients receiving or not receiving acute reperfusion therapy and provided specific recommendations for different treatment subgroups accordingly.

Long-term cognitive and multimodal imaging outcomes after carotid artery stenting vs intensive medication alone for severe asymptomatic carotid stenosis.

BACKGROUND: Severe carotid stenosis is associated with cognitive impairment, which may be attributed to asymptomatic microembolism and/or chronic hypoperfusion. We aim to evaluate the long-term cognitive and brain connectivity outcomes of carotid artery stenting (CAS) for asymptomatic ≥70% stenosis of the extracranial internal carotid artery (ICA). METHODS: We conducted a non-randomized controlled study to compare intensive medical therapy alone (Med) or in combination with carotid artery stenting for the composite vascular events, neuropsychological, and multimodal magnetic resonance perfusion imaging and diffusion tensor imaging outcomes. RESULTS: Sixty-nine patients were followed for a mean of 2.3 years (31 Med, 38 CAS) and 11 patients had composite vascular events of all-cause death, ischemic stroke, or myocardial infarction (6 Med vs 5 CAS). Forty-six asymptomatic subjects completed neuropsychological and multimodality imaging follow-ups (23 Med, 23 CAS). Compared to the Med group, the CAS group had a modest improvement of 12-item delayed verbal memory (8.9 ± 2.4 to 9.8 ± 2.7 vs 9.0 ± 2.1 to 8.9 ± 2.3, p = 0.04), but not in global cognition, attention or executive function, which was associated with increased structural connectivity of fractional anisotropy at the ipsilateral deep white matter. Importantly, the memory improvement was correlated with the perfusion increment at the ipsilateral middle cerebral artery territory. CONCLUSION: For asymptomatic extracranial carotid steno-occlusion, successful carotid revascularization in addition to intensive medical treatment may potentially benefit cognitive reserve and connectivity strength which are partly attributed to restoration of non-critical hypoperfusion.

Neurophysiological signatures of hand motor response to dual-transcranial direct current stimulation in subacute stroke: a TMS and MEG study.

BACKGROUND: Dual transcranial direct current stimulation (tDCS) to the bilateral primary motor cortices (M1s) has potential benefits in chronic stroke, but its effects in subacute stroke, when behavioural effects might be expected to be greater, have been relatively unexplored. Here, we examined the neurophysiological effects and the factors influencing responsiveness of dual-tDCS in subacute stroke survivors. METHODS: We conducted a randomized sham-controlled crossover study in 18 survivors with first-ever, unilateral subcortical ischaemic stroke 2-4 weeks after stroke onset and 14 matched healthy controls. Participants had real dual-tDCS (with an ipsilesional [right for controls] M1 anode and a contralesional M1 [left for controls] cathode; 2 mA for 20mins) and sham dual-tDCS on separate days, with concurrent paretic [left for controls] hand exercise. Using transcranial magnetic stimulation (TMS) and magnetoencephalography (MEG), we recorded motor evoked potentials (MEPs), the ipsilateral silent period (iSP), short-interval intracortical inhibition, and finger movement-related cortical oscillations before and immediately after tDCS. RESULTS: Stroke survivors had decreased excitability in ipsilesional M1 with a relatively excessive transcallosal inhibition from the contralesional to ipsilesional hemisphere at baseline compared with controls, as quantified by decreased MEPs and increased iSP duration. Dual-tDCS led to increased MEPs and decreased iSP duration in ipsilesional M1. The magnitude of the tDCS-induced MEP increase in stroke survivors was predicted by baseline contralesional-to-ipsilesional transcallosal inhibition (iSP) ratio. Baseline post-movement synchronization in α-band activity in ipsilesional M1 was decreased after stroke compared with controls, and its tDCS-induced increase correlated with upper limb score in stroke survivors. No significant adverse effects were observed during or after dual-tDCS. CONCLUSIONS: Task-concurrent dual-tDCS in subacute stroke can safely and effectively modulate bilateral M1 excitability and inter-hemispheric imbalance and also movement-related α-activity.

Premature Atrial Contractions and Their Association with Stroke Features and Outcome.

BACKGROUND: Frequent premature atrial contractions (PACs) are associated with atrial fibrillation, stroke, and mortality. However, the cut-off value for PAC counts that could identify patients with different stroke features is unclear, and the association of PACs to outcome is not determined. METHODS: The study retrospectively included patients with acute ischemic stroke who had underwent both a 24 h Holter recording and a brain MRI in Taipei Veterans General Hospital from January 2015 to May 2016. Patients were categorized into four groups according to their PAC frequencies on 24 h Holter recording. We compared the clinical severity, neuroimage features, stroke subtypes, and functional outcome among the four groups of patients. RESULTS: Among the 278 patients, the lower, middle, and upper quartiles of the PAC counts were 23, 74, and 459.5, respectively. In contrast to the 1st quartile of patients, the 3rd (PAC 75-459/24 h) and the 4th (PAC ≥460/24 h) quartiles of patients had higher NIH Stroke Scale (NIHSS) at admission (p = 0.014 and p = 0.002, respectively). The frequencies of cryptogenic stroke were not different among the 4 quartiles of the patients, but cryptogenic stroke patients with ≥ 75PACs/24hours had higher stroke severity compared to those with PACs < 75counts/24 h (NIHSS 9.1 vs. 5.2, p = 0.043). There was an increased trend in infarcts of multiple vascular territories and in mortality at 1 year among the four groups of patients with increased PAC frequency (p = 0.045 and p = 0.002, respectively). The 4th PAC quartile was associated with poor functional outcome (modified Rankin Scale ≥ 4) at 3 months in univariate analysis (OR: 5.66, CI: 2.69-11.91, p < 0.001), but was not an independent predictor after controlling for initial stroke severity. CONCLUSIONS: PACs ≥ 75 counts/24 h was associated with higher clinical severity in patients with acute ischemic stroke.

Noninferiority Margins in Trials of Thrombectomy Devices for Acute Ischemic Stroke: Is the Bar Being Set Too Low?

Background and Purpose- Novel endovascular thrombectomy (EVT) devices for acute ischemic stroke are often cleared by regulatory agencies on the basis of noninferiority trials. The relation between the noninferiority margins used in trials and the minimal clinically important differences (MCIDs) determined by experts have not been systematically investigated. Methods- Systematic searches were performed to identify (1) all noninferiority design or noninferiority-presented stroke-EVT trials for acute ischemic stroke, (2) all studies determining the MCIDs for the same outcomes, and (3) all noninferiority coronary revascularization trials. Stroke-EVT trial results were reanalyzed using the broad noninferiority margins originally used and narrower noninferiority margins derived from formal MCID studies. Results- We identified 7 noninferiority-designed or noninferiority-interpreted stroke-EVT controlled trials, enrolling 1766 patients, variously comparing coil retrievers, first- and second-generation stent retrievers, and aspiration devices. In 6 trials, the primary outcome was achievement of reperfusion, using noninferiority margins of 15% (3 trials), 10% (2 trials), and 8% (1 trial). In contrast, a stroke expert survey identified the MCID for reperfusion as 3.1% to 5%, and cardiac trials used noninferiority margins of 3.5% to 4.4%. In one stroke-EVT trial, the primary outcome was functional independence, using a noninferiority margin of 15%. However, 2 stroke expert survey studies identified MCIDs for functional independence as having lower values, 5% and 1% to 1.5%. For both reperfusion and functional independence outcomes, all 7 trials demonstrated noninferiority with the broadest noninferiority margin, but only 4 and 3 trials demonstrated noninferiority with actual expert-derived margins for reperfusion and functional independence, respectively. Conclusions- Noninferiority margins used in EVT device trials have regularly exceeded the MCIDs determined by stroke experts, as well as margins used for cardiac devices. New approaches, such as the use of reasonably adequate performance margins, rather than noninferiority margins, are needed to optimize stroke-EVT trial design integrity and trial performance feasibility.

Brain computerized tomography reading in suspected acute ischemic stroke patients: what are essentials for medical students?

BACKGROUND: Few systematic methods prioritize the image education in medical students (MS). We hope to develop a checklist of brain computerized tomography (CT) reading in patients with suspected acute ischemic stroke (AIS) for MS and primary care (PC) physicians. METHODS: Our pilot group generated the items indicating specific structures or signs for the checklist of brain CT reading in suspected AIS patients for MS and PC physicians. These items were used in a modified web-based Delphi process using the online software "SurveyMonkey". In total 15 panelists including neurologists, neurosurgeons, neuroradiologists, and emergency department physicians participated in the modified Delphi process. Each panelist was encouraged to express feedback, agreement or disagreement on the inclusion of each item using a 9-point Likert scale. Items with median scores of 7-9 were included in our final checklist. RESULTS: Fifty-two items were initially provided for the first round of the Delphi process. Of these, 35 achieved general agreement of being an essential item for the MS and PC physicians. The other 17 of the 52 items in this round and another two added items suggested by the panelists were further rated in the next round. Finally, 38 items were included in the essential checklist items of brain CT reading in suspected AIS patients for MS and PC physicians. CONCLUSIONS: We established a reference regarding the essential items of brain CT reading in suspected AIS patients. We hope this helps to minimize malpractice and a delayed diagnosis, and to improve competency-based medical education for MS and PC physicians.

Territory-Related Functional Connectivity Changes Associated with Verbal Memory Decline in Patients with Unilateral Asymptomatic Internal Carotid Stenosis.

BACKGROUND AND PURPOSE: Verbal memory decline is a common complaint of patients with severe asymptomatic stenosis of the internal carotid artery (aICS). Previous publications explored the associations between verbal memory decline and altered functional connectivity (FC) after aICS. Patients with severe aICS may show reduced perfusion in the ipsilateral territory and redistribution of cerebral blood flow to compensate for the deficient regions, including expansion of the posterior and contralateral ICA territories via the circle of Willis. However, aICS-related FC changes in anterior and posterior territories and the impact of the sides of stenosis were less explored. This study aims to investigate the altered FC in anterior and posterior circulation territories of patients with left or right unilateral aICS and its association with verbal memory decline. MATERIALS AND METHODS: We enrolled 15 healthy controls (HCs), 22 patients with left aICS (aICSL), and 33 patients with right aICS (aICSR) to receive fMRI, Mini-Mental State Examination (MMSE), the Digit Span Test (DST), and the 12-item Chinese version of Verbal Learning Tests. We selected brain regions associated with verbal memory within anterior and posterior circulation territories. Territory-related FC alterations and verbal memory decline were identified by comparing the aICSL and aICSR groups with HC groups (P < .05, corrected for multiple comparisons), respectively. Furthermore, the association between altered FC and verbal memory decline was tested with the Pearson correlation analysis. RESULTS: Compared with HCs, patients with aICSL or aICSR had significant impairment in delayed recall of verbal memory. Decline in delayed recall of verbal memory was significantly associated with altered FC between the right cerebellum and right middle temporal pole in the posterior circulation territory (r = 0.40, P = .03) in the aICSR group and was significantly associated with altered FC between the right superior medial frontal gyrus and left lingual gyrus in the anterior circulation territory (r = 0.56, P = .01) in the aICSL group. CONCLUSIONS: Patients with aICSL and aICSR showed different patterns of FC alterations in both anterior and posterior circulation territories, which suggests that the side of aICS influences the compensatory mechanism for decline in delayed recall of verbal memory.

Associations of diabetes status and glucose measures with outcomes after endovascular therapy in patients with acute ischemic stroke: an analysis of the nationwide TREAT-AIS registry.

Background: Hyperglycemia affects the outcomes of endovascular therapy (EVT) for acute ischemic stroke (AIS). This study compares the predictive ability of diabetes status and glucose measures on EVT outcomes using nationwide registry data. Methods: The study included 1,097 AIS patients who underwent EVT from the Taiwan Registry of Endovascular Thrombectomy for Acute Ischemic Stroke. The variables analyzed included diabetes status, admission glucose, glycated hemoglobin (HbA1c), admission glucose-to-HbA1c ratio (GAR), and outcomes such as 90-day poor functional outcome (modified Rankin Scale score ≥ 2) and symptomatic intracranial hemorrhage (SICH). Multivariable analyses investigated the independent effects of diabetes status and glucose measures on outcomes. A receiver operating characteristic (ROC) analysis was performed to compare their predictive abilities. Results: The multivariable analysis showed that individuals with known diabetes had a higher likelihood of poor functional outcomes (odds ratios [ORs] 2.10 to 2.58) and SICH (ORs 3.28 to 4.30) compared to those without diabetes. Higher quartiles of admission glucose and GAR were associated with poor functional outcomes and SICH. Higher quartiles of HbA1c were significantly associated with poor functional outcomes. However, patients in the second HbA1c quartile (5.6-5.8%) showed a non-significant tendency toward good functional outcomes compared to those in the lowest quartile (<5.6%). The ROC analysis indicated that diabetes status and admission glucose had higher predictive abilities for poor functional outcomes, while admission glucose and GAR were better predictors for SICH. Conclusion: In AIS patients undergoing EVT, diabetes status, admission glucose, and GAR were associated with 90-day poor functional outcomes and SICH. Admission glucose was likely the most suitable glucose measure for predicting outcomes after EVT.

Baseline P2Y12 reactivity, kidney function, and CYP2C19 genotype determine clopidogrel responsiveness in acute stroke.

Clopidogrel is the most-widely used platelet P2Y12-inhibitor for secondary-prevention of ischemic stroke. Platelet P2Y12 reactivity before and after inhibitors can be measured with blood sampling by commercialized system. We aimed to evaluate (1) whether high-on-clopidogrel platelet P2Y12 reactivity (HCPR) is associated with short-term vascular events and (2) the predictors of HCPR in acute stroke. The inclusion criterion was patients with acute stroke who received clopidogrel within 12-48 h after the onset. Platelet reactivity was assayed at baseline and after clopidogrel treatment using the VerifyNow system. The primary endpoint was recurrent ischemic events within 21 days after stroke. Among 190 patients, 32(16.9%) had recurrent ischemic stroke. Multivariate analyses showed that HCPR was significantly associated with the short-term events with an odds-ratio of 2.5 (95% CI 1.1-5.7, p = 0.027). Patients with HCPR had significantly higher frequencies of high baseline platelet P2Y12 reactivity, impaired kidney function, and carrying one or two CYP2C19 loss-of-function alleles. A poor clopidogrel response score combining these factors was developed. Ten percent of patients with score 0, 20.3% of those with score 1, 38.3% of those with score 2, and 66.7% of those with score 3 had HCPR (χ2-test, p < 0.001). Multivariate analyses showed that, compared with the score-0 group, the score-2 and -3 groups had higher risks of HCPR with hazard-ratios of 5.4 (95% CI 1.5-20.3, p = 0.012) and 17.4 (95% CI 3.4-88.9, p = 0.001) for developing recurrent ischemic strokes. The study emphasized the role of HCPR in ischemic stroke. We also developed an HCPR risk score, which could be used in clinical practice or trials, potentially with more precision, to weigh the clinical benefit of a tailored antiplatelet-strategy for patients with stroke.

Evaluation of the timing of using direct oral anticoagulants after ischemic stroke for patients with atrial fibrillation.

Background and objective: Patients with atrial fibrillation (AF) are prescribed oral anticoagulants for stroke prevention; however, no evidence indicates that the use of direct oral anticoagulants (DOACs) in the first few days after ischemic stroke (IS) would result in favorable outcomes. This study evaluated the association between the timing of using DOACs after IS and their effectiveness and safety to determine the optimal timing. Methods: In this retrospective cohort study, we reviewed the electronic medical records of Taipei Veterans General Hospital. The 1-year outcomes of patients after DOAC initiation were evaluated. Different initiation time windows were compared (initiation time ≤3 days and >3 days in primary analysis). The primary composite outcome was stroke, transient ischemic attack, systemic embolism, or death due to IS. The primary safety outcome was major bleeding or clinically relevant nonmajor bleeding. The secondary composite outcome was all-cause mortality, thromboembolic event, or acute myocardial infarction/hemorrhagic events. Results: This study included 570 patients. The median initiation time of DOACs after IS in the patients with AF was 14 days. Compared the patients in whom DOACs were initiated after >3 days with those DOACs were initiated after ≤3 days, the adjusted hazard ratios (aHRs) of the primary composite outcome was 0.73 (95% confidence interval [CI]: 0.23-1.79), the aHR of primary safety outcome was 0.87 (95% CI: 0.34-1.90), and the aHR of secondary composite outcome was 0.65 (95% CI: 0.32-1.19). All the results were not statistically significant. In secondary analysis, we tested multiple time points of initiating DOACs. Compared with DOAC initiation after >14 days, the primary composite outcomes in the patients in whom DOACs were initiated ≤3, 4-7, and 8-14 days after IS were the same as the findings of the main analysis. After separating patients into different stroke severity groups, the results were similar to those in the main analysis. Conclusion: No significant association was observed between the timing of using DOACs and ischemic or hemorrhagic outcomes. The findings did not differ among different time points. Although we do not recommend avoiding the initiation of DOACs in the first few days after IS, we should consider that the early initiation of DOACs (≤3 days) would be appropriate only for patients who tend to experience thromboembolic events and have a low risk of bleeding. The optimal timing of initiation still must be confirmed by randomized controlled trials.

The 2023 Taiwan Stroke Society Guidelines for the management of patients with intracranial atherosclerotic disease.

Intracranial atherosclerotic disease (ICAD) is a major cause of ischemic stroke, especially in Asian populations, which has a high risk of recurrent stroke and cardiovascular comorbidities. The present guidelines aim to provide updated evidence-based recommendations for diagnosis and management of patients with ICAD. Taiwan Stroke Society guideline consensus group developed recommendations for management of patients with ICAD via consensus meetings based on updated evidences. Each proposed class of recommendation and level of evidence was approved by all members of the group. The guidelines cover six topics, including (1) epidemiology and diagnostic evaluation of ICAD, (2) nonpharmacological management of ICAD, (3) medical therapy for symptomatic ICAD, (4) endovascular thrombectomy and rescue therapy for acute ischemic stroke with underlying ICAD, (5) endovascular interventional therapy for postacute symptomatic intracranial arterial stenosis, and (6) surgical treatment of chronic symptomatic intracranial arterial stenosis. Intensive medical treatment including antiplatelet therapy, risk factor control, and life style modification are essential for patients with ICAD.

Impairments in cognitive function and brain connectivity in severe asymptomatic carotid stenosis.

BACKGROUND AND PURPOSE: Severe asymptomatic carotid stenosis has been associated with cognitive impairment, but it is unknown whether this association is attributable to effects on brain connectivity. We present cognitive network abnormalities in a group of patients at a presymptomatic stage. METHODS: Seventeen patients with ≥ 70% asymptomatic stenosis of unilateral internal carotid artery were compared with 26 healthy controls utilizing a comprehensive neuropsychological battery, the dizziness handicap inventory, and multimodality neuroimaging including diffusion tensor imaging and resting-state functional connectivity magnetic resonance imaging. Longitudinally, assessments were completed in a subgroup of 10 patients at 3 months after carotid artery stenting. RESULTS: Compared with the healthy controls, the patients had worse dizziness scores, poorer memory, complex visuo-spatial performances, and lower whole-brain mean fractional anisotropy. The Scheltens scores of leukoaraiosis/infarction were not different between groups. Their seed-based functional connectivity magnetic resonance imaging showed marked decrements of interhemispheric and intrahemispheric, ipsilaterally to carotid stenosis, functional connectivity in the frontoparietal network. In the default mode network, the intrahemispheric functional connectivity was bilaterally impaired. Importantly, the disrupted mean fractional anisotropy in the patients significantly correlated with the attention and verbal memory functions. After successful carotid artery stenting, small but measurable increments of the mean fractional anisotropy and little functional connectivity in the default mode network ipsilateral-to-carotid artery stenting were noted. CONCLUSIONS: We identified for the first time distinct patterns of network disruption that correlate with cognitive fragility in patients with asymptomatic carotid stenosis. Brain connectivity may provide early and useful biomarkers for brain ischemia and reperfusion.

Dual vs. mono antiplatelet therapy for acute ischemic stroke or transient ischemic attack with evidence of large artery atherosclerosis.

Background and purpose: Current pieces of evidence support the short-term use of dual antiplatelet (DAPT) in minor ischemic stroke or transient ischemic attack (TIA) based on the studies performed in patients with a broad range of non-cardioembolic stroke mechanisms. However, the efficacy and safety of DAPT use in ischemic stroke patients with large artery atherosclerosis (LAA) are still uncertain. We undertook a systemic search and formal meta-analysis to compare DAPT vs. mono-antiplatelet therapy (MAPT) in patients with etiology specifically presumed to be symptomatic LAA. Methods: We conducted a systemic online search for completed randomized controlled trials that (1) compared DAPT vs. MAPT in patients with acute ischemic stroke or TIA, and (2) were confined to or had available subgroup data regarding population with symptomatic extra- or intracranial artery stenosis. Study-level meta-analysis was performed for outcomes, including ischemic stroke (IS) recurrence, intracranial hemorrhage (ICH), and major bleeding with the Mantel-Haenszel method and random effect models, and was described as risk difference (RD) and 95% CI. Results: A total of 10 trials including 5,004 patients were pooled. Comparing to MAPT, DAPT significantly reduced IS recurrence (5.99 vs. 9.55%, RD: -3%, 95% CI: -5-0%). Across all agents, out of 100 treated patients, 3 fewer had a recurrent ischemic stroke with DAPT. The safety endpoints including ICH (0.28 vs. 0.32%, RD: 0%, 95% CI: -0-0%) and major bleeding (0.73 vs. 0.51%, RD: 0%, 95% CI: -0-0%) did not differ significantly. Conclusion: In patients with symptomatic large artery extracranial or intracranial atherosclerosis, DAPT was superior to MAPT in preventing IS recurrence without increasing bleeding risks. The optimal DAPT regimens and duration of treatment in this population need to be clarified in further studies.

2021 Taiwan Stroke Society Guidelines of blood pressure control for ischemic stroke prevention.

BACKGROUND: Since the publication of the 2015 Taiwan Stroke Society Blood Pressure for Treatment and Prevention of Stroke Guideline (2015 TSS BP Guideline), several new clinical studies have addressed whether a stricter blood pressure (BP) target would be effective for stroke prevention. METHODS: TSS guideline consensus group provides recommendations on BP targets for stroke prevention based on updated evidences. RESULTS: The present guideline covers five topics: (1) diagnosis of hypertension; (2) BP control and primary prevention of ischemic stroke; (3) BP control and secondary prevention of ischemic stroke; (4) BP control and secondary prevention of large artery atherosclerosis ischemic stroke; and (5) BP control and secondary prevention of small vessel occlusion ischemic stroke. CONCLUSION: The BP target for most stroke patients with hypertension is <130/80 mm Hg.

Quantitative CT angiography predicts large artery occlusion types and successful thrombectomy in acute ischemic stroke.

BACKGROUND: Clinical and radiological outcomes of endovascular thrombectomy (EVT) are related to etiologies of large vessel occlusion (LVO) in acute stroke. However, preprocedural computed tomography angiography (CTA) or CT perfusion imaging can hardly distinguish embolic occlusion from atherosclerotic occlusion. We hypothesized that quantitative multiphase CTA (mCTA) of LVO may predict occlusion types and thrombectomy outcome. METHODS: We retrospectively evaluated the consecutive stroke patients who had undergone mCTA and EVT <6 hours of onset at two independent medical centers. The intra-arterial radiodensities of Hounsfield unit (HU) were measured to examine the HUdistal/proximal ratio using receiver operating characteristic curve analysis. The derived cut-off value was re-examined in an independent cohort. RESULTS: In the derivation cohort (n = 102), 81 patients (79.4%) were embolic occlusion without severe residual intracranial atherosclerotic stenosis (ICAS[-]) and 21 patients were atherosclerosis-related occlusion (ICAS[+]) based on digital subtraction angiography (DSA). The optimal cut-off to predict embolic occlusion was HU ratio <0.6 measured at 2 mm from the occlusion site (maximum area under the curve = 0.87; sensitivity 96%; specificity 81%). This cut-off also independently predicted successful recanalization using stent-retrievers and/or contact aspiration (modified Treatment in Cerebral Ischemia score ≥2b; p = 0.002) after adjusting for age, atrial fibrillation, and collateral circulation score, but not predicted favorable outcome at 3 months post stroke. Importantly, in the validation cohort (n = 95, 80% embolic occlusion), this HU ratio cut-off similarly predicted occlusion types and recanalization outcome, respectively. CONCLUSION: The mCTA-based quantitative radiodensities of acute LVO provides preprocedural predictive values of DSA-determined occlusion types and thrombectomy outcomes.

Etiology and risk factors of intracranial hemorrhage and ischemic stroke in young adults.

BACKGROUND: Young stroke incidence has increased worldwide with lifestyle changes. Etiology and risk factors for both ischemic and hemorrhagic stroke in young Asians remain underexplored. METHODS: We retrospectively reviewed consecutive acute stroke patients aged 16-45 years admitted to the Taipei Veterans General Hospital between 2009 and 2019 to analyze etiologic subtypes, risk factors, and serial modified Rankin Scale scores for 1 year and compare the age groups of 16-30 and 31-45 years. RESULTS: Among 670 young Taiwanese patients (mean age at onset 37.5 ± 7.0 years; male 65.1%), there were 366 nontraumatic spontaneous hemorrhagic stroke (including 259 intracerebral hemorrhage [ICH] and 107 subarachnoid hemorrhage, SAH), 292 ischemic stroke and 12 cerebral venous thromboses. Notably, ICH was more prevalent in patients aged 16-30 than in those aged 31-45 (54.8% vs 36.8%). Specifically, structural vasculopathy (e.g., arteriovenous malformation, cavernoma) was the most common etiologic subtype in patients aged 16-30 (p < 0.001), whereas hypertensive ICH was the most common subtype in patients aged 31-45 (p < 0.001). On the other hand, the top ischemic subtype for both age groups was other determined diseases (e.g., arterial dissection, autoimmune diseases, moyamoya disease, etc.) rather than large artery atherosclerosis. Hyperlipidemia, diabetes, and cigarette smoking were more common risk factors for infarction than ICH. Familial stroke patients whose first- or second-degree relatives had a stroke by age 80 (n = 104, 15.5%) had more infarctions than those without a familial stroke history. In multivariate analyses, initial stroke severity, and infarction type were important predictors of favorable outcomes after 3 months. At the 1-year follow-up, patients with ICH and SAH had worse functional outcomes and survival rates than those with infarction. CONCLUSION: An aggressive approach to elucidate the etiology of stroke is indicated because structural vasculopathy-induced ICH and other determined infarction are distinctively prevalent in young adults, particularly those aged 16-30.

The Minimal Clinically Important Difference for Achievement of Substantial Reperfusion With Endovascular Thrombectomy Devices in Acute Ischemic Stroke Treatment.

Background and Purpose: Recent noninferiority clinical trials of novel endovascular thrombectomy devices for acute ischemic stroke have used substantial reperfusion as the primary outcome of achievement. Determining the minimal clinically important difference (MCID) is an essential step for the design of noninferiority clinical trials. Materials and Methods: We surveyed international neuro-interventionalist and noninterventional vascular neurologist investigators. The questionnaire included demographic characteristics, level of clinical experience, and their MCID clinical scenario-based judgment regarding the MCID for the outcome substantial reperfusion (thrombolysis in cerebral infarction score 2b-3) within 3 passes. Results: Survey responses were received from 58 of 200 experts. Among responders, 75.9% were neuro-interventionalists (most commonly interventional neuroradiologists and interventional neurologists, followed by endovascular neurosurgeons), and 24.1% were noninterventional vascular neurologists; 87.9% had been in practice for more than 5 years, and 67.3% devoted more than half of their practice to stroke care. Responder-nonresponder and continuum of resistance analysis indicated responders were representative of the full expert population. Among experts, the median MCID for substantial reperfusion was 3.1-5% (interquartile range 1.1-3% to 5.1-10%). MCID distributions did not differ among neuro-interventionalists and noninterventional vascular neurologists. Conclusions: Neuro-interventionl and noninterventional stroke experts judged that the minimal clinically important difference in comparing thrombectomy devices for achieving substantial reperfusion is 3.1-5%. This MCID, lower than noninferiority margins used in several recent clinical trials, can inform trial designs and clinical development.

Major bleeding risk with non-vitamin K antagonist oral anticoagulant vs. aspirin in heart failure: network meta-analysis.

AIMS: Relative bleeding risks of different antithrombotic agents in heart failure (HF) patients is an important consideration in treatment decision making, making detailed comparative analysis desirable. The aim of this study was to conduct a network meta-analysis to investigate the major bleeding risk for individual novel oral anticoagulants (NOACs) vs. aspirin among patients with HF. METHODS AND RESULTS: We searched Pubmed, EMBASE, Cochrane Collaboration Central Register of Controlled Clinical Trials, and Clinicaltrials.gov from 1966 to November 2019 to identify relevant randomized clinical trials. Studies comparing individual NOACs vs. aspirin were analysed using direct study-level meta-analysis. Studies comparing aspirin to warfarin and NOACs to warfarin were then additionally added using network (direct and indirect) study-level meta-analysis. Primary endpoint was major bleeding. Final analysis included nine trials with 34 367 participants, including one direct comparison trial (apixaban vs. aspirin) and eight indirect comparison trials against the shared warfarin comparator (four aspirin trials and one trial each of apixaban, dabigatran, rivaroxaban, and edoxaban). For apixaban, network meta-analysis combing direct and indirect comparison showed that major bleeding risk might not be different between apixaban and aspirin (odds ratio, 1.18 [95% confidence interval, 0.38 to 3.65]) in HF patients. In contrast, indirect-comparison meta-analysis showed dabigatran, rivaroxaban, and edoxaban compared with aspirin might be associated with a higher risk of major bleeding in HF patients. CONCLUSIONS: In network meta-analysis, apixaban might be associated with a comparable risk of major bleeding compared with aspirin in patients with HF, while other NOACs might be associated with a higher risk. However, such results were not strongly convincing because of lack of direct comparison in an original trial and small sample size of trials and participants. A clinical trial directly comparing apixaban vs. aspirin in patients with HF and sinus rhythm may be worth undertaking.