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Abstract Background Endovascular therapy (EVT) is the treatment of choice for acute ischemic stroke (AIS) with large vessel occlusion. However, in many patients, successful EVT recanalization does not correspond to a clinical improvement, called futile recanalization (FR). We aimed to identify stroke risk factors and patient characteristics associated with FR in AIS with large core infarct (LCI). Methods A total of 137 patients with AIS with LCI treated by EVT at a single stroke center were retrospectively included from January 2016 to June 2023. LCI was defined by Diffusion-Weighted Imaging-Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECT)

Abstract This study aimed to investigate the association between non-traditional lipid profiles and the risk of 1-year vascular events in patients who were already using statins before stroke and had admission LDL-C

Abstract It is uncertain whether the prognostic power of white matter hyperintensity (WMH) on post-stroke outcomes is modulated as a function of initial neurological severity, a critical determinant of outcome after stroke. This multi-center MRI study tested if higher WMH quintiles were associated with 3-month poor functional outcome (modified Rankin Scale ≥ 3) for mild versus moderate-to-severe ischemic stroke. Mild and moderate-to-severe stroke were defined as admission National Institute of Health Stroke Scale scores of 1–4 and ≥ 5, respectively. Mean age of the enrolled patients (n = 8918) was 67.2 ± 12.6 years and 60.1% male. The association between WMH quintiles and poor functional outcome was modified by stroke severity (p-for-interaction = 0.008). In mild stroke (n = 4994), WMH quintiles associated with the 3-month outcome in a dose-dependent manner for the 2nd to 5th quintile versus the 1st quintile, with adjusted-odds-ratios (aOR [95% confidence interval]) being 1.29 [0.96–1.73], 1.37 [1.02–1.82], 1.60 [1.19–2.13], and 1.89 [1.41–2.53], respectively. In moderate-to-severe stroke (n = 3924), however, there seemed to be a threshold effect: only the highest versus the lowest WMH quintile was significantly associated with poor functional outcome (aOR 1.69 [1.29–2.21]). WMH burden aggravates 3-month functional outcome after mild stroke, but has a lesser modulatory effect for moderate-to-severe stroke, likely due to saturation effects.

Background Perfusion imaging (PI) serves as a valuable tool for triaging patients with acute ischemic stroke for endovascular treatment (EVT). This study aims to investigate trends in PI use and its impacts on EVT rates and clinical outcomes, particularly focusing on variations across different time windows. Methods Data from a prospective, nationwide, acute stroke registry in South Korea were analyzed retrospectively. PI was regarded as treatment‐decision imaging when conducted either (1) prior to EVT, or (2) within 3 hours from hospital arrival in patients not receiving EVT. The study spanned 3 epochs: 2011–2014, 2015–2017, and 2018–2021. Based on the time from onset to arrival, patients were categorized into 2 time windows: early (0–6 hours) and late (6–24 hours). We evaluated EVT rates and clinical outcomes in patients with anterior large vessel occlusion. Results From 2011 to 2021 among 49 449 patients with acute ischemic stroke presenting within 24 hours of onset, PI use rates declined from 36.9% to 30.1%. In the early window, rates dropped from 48.4% to 32.4%, whereas in the late window, they increased from 23.5% to 27.8%. Factors such as older age, atrial fibrillation, anterior large vessel occlusion, and severe stroke were associated with higher rates in the late window. Conversely, younger age and male sex were associated with higher rates in the early window. For patients with anterior large vessel occlusion, PI use increased the likelihood of receiving EVT in the late window and minimized the risk of symptomatic intracranial hemorrhage in the early window. However, 3‐month functional outcomes and mortality were. unaffected. Conclusion The study revealed distinct trends in PI use across early and late time windows, indicating varying roles of PI in these time frames. However, the definitive value and necessity of PI in guiding EVT decision‐making remain unclear, underscoring the need for further research

Background Multiple randomized trials could not establish the noninferiority of endovascular thrombectomy (EVT) alone without preceding intravenous thrombolysis (IVT) or superiority of IVT followed by EVT in anterior circulation large‐vessel occlusion stroke. The role of prior IVT in posterior circulation large‐vessel occlusion remains controversial. Methods In this multicenter, retrospective study, patients with stroke with large‐vessel occlusion in the posterior circulation who received EVT alone or with IVT were selected from the stroke thrombectomy and aneurysm registry between 2013 and 2022. Effects of IVT followed by thrombectomy on favorable functional outcome (defined as modified Rankin scale≤3 at 90 days) and safety were investigated using multivariable logistic and linear regression models. Results Of the 588 included patients, 67% (n = 394) were treated with EVT alone and 29% (n = 170) with EVT after IVT, and 4% (n = 24) have missing values on this variable. Controlling for multiple confounding factors, IVT was not associated with a higher likelihood of favorable functional outcome at 90 days (odds ratio, 1.04 [95% CI, 0.52–2.09; P = 0.901). Thrombectomy alone did not show any safety advantages compared with those receiving IVT. Conclusion Similar functional outcomes and complication rates were seen in patients with posterior circulation large‐vessel occlusion treated with EVT alone versus EVT after IVT. Further prospective studies are required to determine the utility of IVT in posterior circulation stroke, especially in patients being directly admitted to thrombectomy centers.

Background and Purpose Accurate classification of ischemic stroke subtype is important for effective secondary prevention of stroke. We used diffusion-weighted image (DWI) and atrial fibrillation (AF) data to train a deep learning algorithm to classify stroke subtype. Methods Model development was done in 2,988 patients with ischemic stroke from three centers by using U-net for infarct segmentation and EfficientNetV2 for subtype classification. Experienced neurologists (n=5) determined subtypes for external test datasets, while establishing a consensus for clinical trial datasets. Automatically segmented infarcts were fed into the model (DWI-only algorithm). Subsequently, another model was trained, with AF included as a categorical variable (DWI+AF algorithm). These models were tested: (1) internally against the opinion of the labeling experts, (2) against fresh external DWI data, and (3) against clinical trial dataset. Results In the training-and-validation datasets, the mean (±standard deviation) age was 68.0±12.5 (61.1% male). In internal testing, compared with the experts, the DWI-only and the DWI+AF algorithms respectively achieved moderate (65.3%) and near-strong (79.1%) agreement. In external testing, both algorithms again showed good agreements (59.3%–60.7% and 73.7%–74.0%, respectively). In the clinical trial dataset, compared with the expert consensus, percentage agreements and Cohen’s kappa were respectively 58.1% and 0.34 for the DWI-only vs. 72.9% and 0.57 for the DWI+AF algorithms. The corresponding values between experts were comparable (76.0% and 0.61) to the DWI+AF algorithm. Conclusion Our model trained on a large dataset of DWI (both with or without AF information) was able to classify ischemic stroke subtypes comparable to a consensus of stroke experts.

IntroductionWe developed and externally validated a fully automated algorithm using deep learning to detect large vessel occlusion (LVO) in computed tomography angiography (CTA).MethodA total of 2,045 patients with acute ischemic stroke who underwent CTA were included in the development of our model. We validated the algorithm using two separate external datasets: one with 64 patients (external 1) and another with 313 patients (external 2), with ischemic stroke. In the context of current clinical practice, thrombectomy amenable vessel occlusion (TAVO) was defined as an occlusion in the intracranial internal carotid artery (ICA), or in the M1 or M2 segment of the middle cerebral artery (MCA). We employed the U-Net for vessel segmentation on the maximum intensity projection images, followed by the application of the EfficientNetV2 to predict TAVO. The algorithm’s diagnostic performance was evaluated by calculating the area under the receiver operating characteristics curve (AUC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).ResultsThe mean age in the training and validation dataset was 68.7 ± 12.6; 56.3% of participants were men, and 18.0% had TAVO. The algorithm achieved AUC of 0.950 (95% CI, 0.915–0.971) in the internal test. For the external datasets 1 and 2, the AUCs were 0.970 (0.897–0.997) and 0.971 (0.924–0.990), respectively. With a fixed sensitivity of 0.900, the specificities and PPVs for the internal test, external test 1, and external test 2 were 0.891, 0.796, and 0.930, and 0.665, 0.583, and 0.667, respectively. The algorithm demonstrated a sensitivity and specificity of approximately 0.95 in both internal and external datasets, specifically for cases involving intracranial ICA or M1-MCA occlusion. However, the diagnostic performance was somewhat reduced for isolated M2-MCA occlusion; the AUC for the internal and combined external datasets were 0.903 (0.812–0.944) and 0.916 (0.816–0.963), respectively.ConclusionWe developed and externally validated a fully automated algorithm that identifies TAVO. Further research is needed to evaluate its effectiveness in real-world clinical settings. This validated algorithm has the potential to assist early-career physicians, thereby streamlining the treatment process for patients who can benefit from endovascular treatment.

Background and Purpose Outcomes following mechanical thrombectomy (MT) are strongly correlated with successful recanalization, traditionally defined as modified Thrombolysis in Cerebral Infarction (mTICI) ≥2b. This retrospective cohort study aimed to compare the outcomes of patients with low Alberta Stroke Program Early Computed Tomography Score (ASPECTS; 2–5) who achieved mTICI 2b versus those who achieved mTICI 2c/3 after MT. Methods This study utilized data from the Stroke Thrombectomy and Aneurysm Registry (STAR), which combined databases from 32 thrombectomy-capable stroke centers between 2013 and 2023. The study included only patients with low ASPECTS who achieved mTICI 2b, 2c, or 3 after MT for internal carotid artery or middle cerebral artery (M1) stroke. Results Of the 10,229 patients who underwent MT, 234 met the inclusion criteria. Of those, 98 (41.9%) achieved mTICI 2b, and 136 (58.1%) achieved mTICI 2c/3. There were no significant differences in baseline characteristics between the two groups. The 90-day favorable outcome (modified Rankin Scale score: 0–3) was significantly better in the mTICI 2c/3 group than in the mTICI 2b group (adjusted odds ratio 2.35; 95% confidence interval [CI] 1.18–4.81; P=0.02). Binomial logistic regression revealed that achieving mTICI 2c/3 was significantly associated with higher odds of a favorable 90-day outcome (odds ratio 2.14; 95% CI 1.07–4.41; P=0.04). Conclusion In patients with low ASPECTS, achieving an mTICI 2c/3 score after MT is associated with a more favorable 90-day outcome. These findings suggest that mTICI 2c/3 is a better target for MT than mTICI 2b in patients with low ASPECTS.

Background Recent clinical trials established the benefit of dual antiplatelet therapy with aspirin and clopidogrel (DAPT‐AC) in early‐presenting patients with minor ischemic stroke. However, the impact of these trials over time on the use and outcomes of DAPT‐AC among the patients with nonminor or late‐presenting stroke who do not meet the eligibility criteria of these trials has not been delineated. Methods and Results In a multicenter stroke registry, this study examined yearly changes from April 2008 to August 2022 in DAPT‐AC use for stroke patients ineligible for CHANCE/POINT (Clopidogrel in High‐Risk Patients with Acute Nondisabling Cerebrovascular Events/Platelet‐Oriented Inhibition in New TIA and Minor Ischemic Stroke) clinical trials due to National Institutes of Health Stroke Scale >4 or late arrival beyond 24 hours of onset. A total of 32 118 patients (age, 68.1±13.1 years; male, 58.5%) with National Institutes of Health Stroke Scale of 4 (interquartile range, 1–7) were analyzed. In 2008, DAPT‐AC was used in 33.0%, other antiplatelets in 62.7%, and no antiplatelet in 4.3%. The frequency of DAPT‐AC was relatively unchanged through 2013, when the CHANCE trial was published, and then increased steadily, reaching 78% in 2022, while other antiplatelets decreased to 17.8% in 2022 (Ptrend

Abstract We hypothesized that the association between BP and endovascular treatment (EVT) outcomes would differ by baseline perfusion and recanalization status. We identified 388 ICA or M1 occlusion patients who underwent EVT ≤ 24 h from onset with successful recanalization (TICI ≥ 2b). BP was measured at 5-min intervals from arrival and during the procedure. Systolic BPs (SBP) were summarized as dropmax (the maximal decrease over two consecutive measurements), incmax (the maximal increase), mean, coefficient of variation (cv), and standard deviation. Adequate baseline perfusion was defined as hypoperfusion intensity ratio (HIR) ≤ 0.5; infarct proportion as the volume ratio of final infarcts within the Tmax > 6 s region. In the adequate perfusion group, infarct proportion was closely associated with SBPdropmax (β ± SE (P-value); 1.22 ± 0.48, (

Background As the number of thrombectomy passes increases during endovascular therapy (EVT) for acute stroke, neurointerventionalists must weigh the risks of potential complications against the risk of failing to recanalize the affected vessel. Thus, we investigated the effectiveness and safety of EVT for patients with acute stroke in which ≥5 EVT passes were performed. Methods This retrospective cohort study from January 2013 to December 2022 included 31 thrombectomy‐capable centers. Patients in whom ≥5 EVT passes were made were included in the analysis. The patients with successful recanalization defined as modified Thrombolysis in Cerebral Infarction ≥2b at 5, 6, 7, or more passes were compared with unsuccessful recanalization. We also compared procedure time, separated by 30 minutes. Primary outcome was a favorable 90‐day outcome (modified Rankin scale score of 0–2). Secondary outcomes were intracranial hemorrhage and death. Results A total of 407 patients met the inclusion criteria, of which 175 were women (43.1%); the mean age was 67.3 years. In 265 (65.1%) patients, successful recanalization was achieved: 134 patients with 5 passes, 67 patients with 6 passes, and 64 with ≥7 passes. Intravenous recombinant tissue plasminogen activator administration was more common in the unsuccessful recanalization group (successful recanalization with 5, 6, and ≥7 EVT passes and unsuccessful recanalization: 35.3%, 30.3%, 18.8%, and 45.4%, respectively). Successful recanalization with 5, 6, and ≥7 EVT passes was associated with favorable outcome compared with unsuccessful recanalization group (adjusted odds ratio successful recanalization with 5, 6, and ≥7 EVT passes to unsuccessful recanalization [95% CIs]: 8.29 [2.13–32.3]; 14.0 [3.27–60.3]; and 5.26 [1.12–24.8], respectively). However, symptomatic intracranial hemorrhage was not significantly different between the groups. Regarding procedure time, favorable outcome was not significantly different in each group, while symptomatic intracranial hemorrhage occurred more frequently in the 60 to 89 minutes group compared with the

Objectives Age-related hearing loss (ARHL), or presbycusis, is caused by disorders of sensory hair cells and auditory neurons. Many studies have suggested that the accumulation of mitochondrial DNA damage, the production of reactive oxygen species, noise, inflammation, and decreased antioxidant function are associated with subsequent cochlear senescence in response to aging stress. Long non-coding RNA (lncRNA) has been reported to play important roles in various diseases. However, the function of lncRNA in ARHL remains unclear. In this study, we analyzed the common expression profiles of messenger RNA (mRNA) and lncRNA through ARHL-related RNA-sequencing datasets. Methods We selected and downloaded three different sets of RNA-sequencing data for ARHL. We performed differential expression analysis to find common mRNA and lncRNA profiles in the cochleae of aged mice compared to young mice. Gene Ontology (GO) analysis was used for functional exploration. Real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was performed to validate mRNAs and lncRNAs. In addition, we performed trans target prediction analysis with differentially expressed mRNAs and lncRNAs to understand the function of these mRNAs and lncRNAs in ARHL. Results We identified 112 common mRNAs and 10 common lncRNAs in the cochleae of aged mice compared to young mice. GO analysis showed that the 112 upregulated mRNAs were enriched in the defense response pathway. When we performed qRT-PCR with 1 mM H2O2-treated House Ear Institute-Organ of Corti 1 (HEI-OC1) cells, the qRT-PCR results were consistent with the RNA-sequencing analysis data. lncRNA-mRNA networks were constructed using the 10 common lncRNAs and 112 common mRNAs in ARHL. Conclusion Our study provides a comprehensive understanding of the common mRNA and lncRNA expression profiles in ARHL. Knowledge of ARHL-associated mRNAs and lncRNAs could be useful for better understanding ARHL and these mRNAs and lncRNAs might be a potential therapeutic target for preventing ARHL.

Background It is unclear whether statin treatment could reduce the risk of early vascular events when baseline low‐density lipoprotein cholesterol (LDL‐C) levels are already low, at

Background Approximately 10% of patients with acute ischemic stroke with large‐vessel occlusion (LVO) have mild neurological deficits. Although leptomeningeal collaterals (LMCs) are the major determinant of clinical outcomes for patients with acute ischemic stroke with LVO, the contribution of baseline LMC status to subsequent infarct progression in patients with mild stroke with LVO is poorly defined. Methods This observational study included patients with acute anterior circulation LVO and mild stroke symptoms (National Institutes of Health Stroke Scale < 6) from a prospectively collected, multicenter, national stroke registry. The Alberta Stroke Program Early Computed Tomography Score was quantified on the initial and follow‐up images. An infarct progression, defined as any Alberta Stroke Program Early Computed Tomography Score decrease between the initial versus follow‐up scans, was categorized as either 0/1/2+. The LMCs on the baseline images were graded as good, fair, or poor. Results Of the 623 included patients (mean age, 67.6±13.4 years; 380 [61.0%] men; 186 [29.9%] with reperfusion treatment), the baseline LMC was graded as good in 331 (53.1%), fair in 219 (35.2%), and poor in 73 (11.7%). The Alberta Stroke Program Early Computed Tomography Score decrement was noted as 0 in 288 (46%) patients, 1 in 154 (24%), and 2+ in 181 (29%). A poor LMC was associated with an infarct progression (adjusted odds ratio, 2.05 [95% CI, 1.22–3.47]). Conclusions Poor collateral blood flow was associated with infarct progression in patients with acute ischemic stroke with LVO and mild symptoms. In this selective population, early assessment of collateral blood flow status can help in early detection of patients susceptible to infarct progression.

Abstract This study aimed to elucidate whether low-density lipoprotein cholesterol (LDL-C) levels differentially affect functional outcomes after intravenous thrombolysis (IVT) depending on prestroke statin use. Patients with acute ischemic stroke treated with IVT were categorized into low, intermediate, and high LDL-C groups based on LDL-C levels at admission ( 130 mg/dl, respectively). Multivariable logistic regression analyses were performed to explore the relationships between LDL-C and clinical outcomes (good outcomes at 3 months, modified Rankin Scale scores 0–2). The interaction between LDL-C levels and prestroke statin use regarding functional outcomes was investigated. Among the 4711 patients (age, 67 ± 12 years; males, 62.1%) who met the eligibility criteria, compared with the high LDL-C group, the low and intermediate LDL-C groups were not associated with good outcomes at 3 months according to the multivariable analysis. A potential interaction between the LDL-C group and prestroke statin use on good outcomes at 3 months was observed (P interaction = 0.07). Among patients with prestroke statin use, low (aOR 1.84 [1.04–3.26]) and intermediate (aOR 2.31 [1.20–4.47]) LDL-C groups were independently associated with a greater likelihood of having a 3-month good outcome. Our study showed that LDL-C was not associated with a 3-month good outcome, but prestroke statin use could modify the influence of LDL-C levels on functional outcomes after IVT.

Abstract Clustering stroke patients with similar characteristics to predict subsequent vascular outcome events is critical. This study aimed to compare several clustering methods, particularly a deep neural network-based model, and identify the best clustering method with a maximally distinct 1-year outcome in patients with ischemic stroke. Prospective stroke registry data from a comprehensive stroke center from January 2011 to July 2018 were retrospectively analyzed. Patients with acute ischemic stroke within 7 days of onset were included. The primary outcomes were the composite of all strokes (either hemorrhagic or ischemic), myocardial infarction, and all-cause mortality within one year. Neural network-based clustering models (deep lifetime clustering) were compared with other clustering models (k-prototype and semi-supervised clustering, SSC) and a conventional risk score (Stroke Prognostic Instrument-II, SPI-II) to obtain a distinct distribution of 1-year vascular events. Ultimately, 7,650 patients were included, and the 1-year primary outcome event occurred in 13.1%. The DLC-Kuiper UB model had a significantly higher C-index (0.674), log-rank score (153.1), and Brier score (0.08) than the other cluster models (SSC and DLC-MMD) and the SPI-II score. There were significant differences in primary outcome events among the 3 clusters (41.7%, 13.4%, and 6.5% in clusters 0, 1, and 2, respectively) when the DLC-Kuiper UB model was used. A neural network-based clustering model, the DLC-Kuiper UB model, can improve the clustering of stroke patients with a maximally distinct distribution of 1-year vascular outcomes among each cluster. Further studies are warranted to validate this deep neural network-based clustering model in ischemic stroke.

Background Mechanical thrombectomy of middle cerebral artery M2 segment occlusion of the middle cerebral artery has reported safety and efficacy in recent post‐hoc and observational studies. However, there is no known benefit of mechanical thrombectomy for patients with M2 segment occlusions in the delayed time window (>6 hours). Methods The Stroke Thrombectomy and Aneurysm Registry (STAR) is a prospective, multicenter, nonrandomized observational study registry for acute ischemic stroke thrombectomy and aneurysm treatment. We analyzed all patients who underwent mechanical thrombectomy within the late time window (>6 hours from symptom onset) involving isolated M2 occlusions. We used propensity score matching to select a comparison group of patients who underwent mechanical thrombectomy for M1 occlusion in the same time window. Results Of 1083 consecutive patients analyzed, propensity matching yielded 180 well matched M1 and M2 pairs. Baseline demographics were well balanced between the groups (M1 and M2). Alberta stroke program early CT score (7.6±1.7 versus 8.3±1.5; P

Antithrombotic therapy is a cornerstone of acute ischemic stroke (AIS) management and secondary stroke prevention. Since the first version of the Korean Clinical Practice Guideline (CPG) for stroke was issued in 2009, significant progress has been made in antithrombotic therapy for patients with AIS, including dual antiplatelet therapy in acute minor ischemic stroke or high-risk transient ischemic stroke and early oral anticoagulation in AIS with atrial fibrillation. The evidence is widely accepted by stroke experts and has changed clinical practice. Accordingly, the CPG Committee of the Korean Stroke Society (KSS) decided to update the Korean Stroke CPG for antithrombotic therapy for AIS. The writing members of the CPG committee of the KSS reviewed recent evidence, including clinical trials and relevant literature, and revised recommendations. A total of 35 experts were invited from the KSS to reach a consensus on the revised recommendations. The current guideline update aims to assist healthcare providers in making well-informed decisions and improving the quality of acute stroke care. However, the ultimate treatment decision should be made using a holistic approach, considering the specific medical conditions of individual patients.

BackgroundIsolated (hemi)nodular strokes as underlying cause of acute dizziness are rare, thus there are still gaps of knowledge in the clinical presentation of affected patients. Clinical and experimental evidence has suggested that lesions involving the nodulus lead to various vestibulo-ocular deficits including prolonged velocity-storage, periodic-alternating nystagmus, positional nystagmus, abolished suppression of post-rotatory nystagmus by head-tilt and impaired verticality perception. At the bedside, the angular vestibulo-ocular reflex (aVOR), as assessed by the horizontal head-impulse test (HIT), has been reported to be normal, however quantitative assessments of all six semicircular canals are lacking.ObjectiveThe primary aim of this case series was to characterize the spectrum of clinical presentations in isolated (hemi)nodular strokes. Furthermore, based on preliminary observations, we hypothesized that the aVOR is within normal limits in isolated nodular strokes.MethodsWe retrospectively included patients with isolated (hemi)nodular stroke on diffusion-weighted MR-imaging from a prospective stroke-registry. All patients received a standardized bedside neuro-otological assessment and quantitative, video-based HIT (vHIT) of all six semicircular canals. Overall ratings of vHIT (normal vs. abnormal function) were performed independently by two reviewers and disagreements were resolved.ResultsBetween January 2015 and December 2021 six patients with isolated nodular (n = 1) or heminodular (n = 5) ischemic stroke were included. Clinical presentation met diagnostic criteria for acute vestibular syndrome (AVS) in 5/6 patients and for episodic vestibular syndrome (EVS) in 1/6 patients. Ocular motor abnormalities observed included the presence of spontaneous horizontal nystagmus (n = 2), positional nystagmus (5/6), head-shaking nystagmus (3/6), skew deviation (n = 1), and moderate or severe truncal ataxia (5/6). Bedside HIT was normal in all patients and no gaze-evoked or periodic alternating nystagmus was observed. aVOR-gains were within normal range in all patients and overall aVOR-function as assessed by vHIT was rated as normal in all six patients.ConclusionsUsing quantitative, video-based testing of the horizontal and vertical aVOR, preserved integrity of the aVOR in (hemi)nodular strokes was confirmed, extending preliminary findings at the bedside. Furthermore, widespread deficits of both ocular stability, postural control and volitional eye movements were observed in our study cohort, being consistent with findings reported in previous studies.

Abstract We aimed to develop a novel prediction model for early neurological deterioration (END) based on an interpretable machine learning (ML) algorithm for atrial fibrillation (AF)-related stroke and to evaluate the prediction accuracy and feature importance of ML models. Data from multicenter prospective stroke registries in South Korea were collected. After stepwise data preprocessing, we utilized logistic regression, support vector machine, extreme gradient boosting, light gradient boosting machine (LightGBM), and multilayer perceptron models. We used the Shapley additive explanation (SHAP) method to evaluate feature importance. Of the 3,213 stroke patients, the 2,363 who had arrived at the hospital within 24 h of symptom onset and had available information regarding END were included. Of these, 318 (13.5%) had END. The LightGBM model showed the highest area under the receiver operating characteristic curve (0.772; 95% confidence interval, 0.715–0.829). The feature importance analysis revealed that fasting glucose level and the National Institute of Health Stroke Scale score were the most influential factors. Among ML algorithms, the LightGBM model was particularly useful for predicting END, as it revealed new and diverse predictors. Additionally, the effects of the features on the predictive power of the model were individualized using the SHAP method.

Background Mechanical thrombectomy has become the first‐line treatment strategy for patients with large‐vessel occlusion strokes. Often >1 thrombectomy maneuver is necessary to achieve reperfusion. A first‐pass (FP) effect with improved functional outcomes after mechanical thrombectomy has been described. Aim of the present study is to investigate the FP effect in a large, international, multicenter stroke database. Methods Patients who underwent mechanical thrombectomy for large‐vessel occlusion stroke in the anterior cerebral circulation between January 2014 and January 2021 and achieved complete reperfusion were identified from the STAR (Stroke Thrombectomy and Aneurysm Registry). We compared functional outcomes of patients with FP (defined as modified treatment in cerebral ischemia score 3 after a single thrombectomy maneuver) versus multiple‐pass complete reperfusion (defined as modified treatment in cerebral ischemia 3 after ≥1 thrombectomy maneuver). Results A total of 1481 patients with anterior circulation large‐vessel occlusion stroke and successful recanalization were included in the analysis. FP complete recanalization was achieved in 778 patients versus 703 patients with multiple‐pass complete reperfusion. Patients with FP complete recanalization had higher Alberta Stroke Programme Early CT [Computed Tomography] Score at baseline (9 [7–10] versus 8 [7–10]; P=0.002), were less likely to be men (47% versus 51%; P=0.078) and to have intracranial internal carotid artery occlusions (14% versus 27%), as well as more likely to have M1/M2 occlusions (86% versus 73%; P

Background and purposeThere is much uncertainty in endovascular treatment (EVT) decisions in patients with acute large vessel occlusion (LVO) and mild neurological deficits.MethodsFrom a prospective, nationwide stroke registry, all patients with LVO and baseline NIHSS

Background In cases of failed recanalization despite modern mechanical thrombectomy (MT) techniques, intracranial rescue stenting (RS) may be beneficial. However, outcomes and complications of RS relative to the natural history of ongoing emergent large vessel occlusion are unknown. To evaluate whether RS for ongoing emergent large vessel occlusion after failed MT achieves superior outcomes to the natural history of persistent emergent large vessel occlusion. Methods Patients from the Stroke Thrombectomy and Aneurysm Registry who underwent RS after failed MT from 2014 to 2019 were analyzed. For outcome comparisons, patients were screened for inclusion/exclusion criteria of 3 major randomized, controlled MT trials. Results Over 5 years, 2827 patients underwent thrombectomy, of which 120 required RS for failed revascularization. RS resulted in reperfusion (Thrombolysis in Cerebral Infarction≥2B) in 85.8%. Good 90‐day clinical outcomes (modified Rankin scale 0–2) were achieved in 33.9% of patients. Inclusion/exclusion criteria was met in 50 patients for MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands), 64 patients for ESCAPE (Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke), and 45 patients for DAWN (DWI or CTP Assessment With Clinical Mismatch in the Triage of Wake‐Up and Late Presenting Strokes Undergoing Neurointervention). Of patients meeting trial criteria, 40.8% of the RS cohort achieved modified Rankin scale 0–2 versus 19% in the MR CLEAN medical arm (P

Abstract Serotonin (5-HT) plays an important role in cerebrovascular homeostasis and psychiatric disorders, including suicidality. Methylation of the serotonin transporter gene (SLC6A4) is associated with 5-HT expression. However, the prognostic roles of SLC6A4 methylation and suicidal ideation (SI) in long-term outcomes of stroke have not been evaluated. We investigated the independent and interactive effects of SLC6A4 methylation and SI immediately after stroke on long-term outcomes. Blood SLC6A4 methylation status and SI based on the suicide item of the Montgomery–Åsberg Depression Rating Scale were assessed in 278 patients at 2 weeks after stroke. After the index stroke, cerebro-cardiovascular events by SLC6A4 methylation status and SI were investigated over an 8–14-year follow-up period and using Cox regression models adjusted for a range of covariates. SLC6A4 hypermethylation and SI within 2 weeks of stroke both predicted worse long-term outcomes, independent of covariates. A significant interaction effect of SI and the methylation status of CpG 4 on long-term stroke outcomes was also identified. The association between SLC6A4 methylation and long-term adverse outcomes may be strengthened in the presence of SI within 2 weeks after stroke. Evaluation of methylation and SI status during the acute phase can be helpful when assessing stroke patients.

Abstract We investigated a multicenter registry to identify estimated event rates according to CHA2DS2-VASc scores in patients with acute ischemic stroke (AIS) and atrial fibrillation (AF). The additional effectiveness of antiplatelets (APs) plus oral anticoagulants (OACs) compared with OACs alone considering the CHA2DS2-VASc scores was also explored. This study retrospectively analyzed a multicenter stroke registry between Jan 2011 and Nov 2017, identifying patients with acute ischemic stroke with AF. The primary outcome event was a composite of recurrent stroke, myocardial infarction, and all-cause mortality within 1 year. A total of 7395 patients (age, 73 ± 10 years; men, 54.2%) were analyzed. The primary outcome events at one year ranged from 5.99% (95% CI 3.21–8.77) for a CHA2DS2-VASc score of 0 points to 30.45% (95% CI 24.93–35.97) for 7 or more points. After adjustments for covariates, 1-point increases in the CHA2DS2-VASc score consistently increased the risk of primary outcome events (aHR 1.10 [1.06–1.15]) at 1-year. Among OAC-treated patients at discharge (n = 5500), those treated with OAC + AP (vs. OAC alone) were more likely to experience vascular events, though among patients with a CHA2DS2-VASc score of 5 or higher, the risk of primary outcome in the OAC + AP group was comparable to that in the OAC alone group (Pint = 0.01). Our study found that there were significant associations of increasing CHA2DS2-VASc scores with the increasing risk of vascular events at 1-year in AIS with AF. Further study would be warranted.

Background Unlike patients with stroke caused by other mechanisms, the effect of elevated plasma total homocysteine (tHcy) on the prognosis of patients with both ischemic stroke and atrial fibrillation (AF) is unknown. This study aimed to evaluate the association between tHcy level and the functional outcome of patients with AF‐related stroke. Methods and Results We included consecutive patients with AF‐related stroke between 2013 and 2015 from the registry of a real‐world prospective cohort from 11 large centers in South Korea. A 3‐month modified Rankin Scale score ≥3 was considered an unfavorable outcome. Since tHcy is strongly affected by renal function, we performed a subgroup analysis according to the presence of renal dysfunction. A total of 910 patients with AF‐related stroke were evaluated (mean age, 73 years; male sex, 56.0%). The mean tHcy level was 11.98±8.81 μmol/L. In multivariable analysis, the tHcy level (adjusted odds ratio, 1.04; 95% CI, 1.01–1.07, per 1 μmol/L) remained significantly associated with unfavorable outcomes. In the subgroup analysis based on renal function, tHcy values above the cutoff point (≥14.60 μmol/L) showed a close association with the unfavorable outcome only in the normal renal function group (adjusted odds ratio, 3.10; 95% CI, 1.60–6.01). In patients with renal dysfunction, tHcy was not significantly associated with the prognosis of AF‐related stroke. Conclusions A higher plasma tHcy level was associated with unfavorable outcomes in patients with AF‐related stroke. This positive association may vary according to renal function but needs to be verified in further studies.

Background Previous literature about the effect of heart rate on poststroke outcomes is limited. We attempted to elucidate (1) whether heart rate during the acute period of ischemic stroke predicts subsequent major clinical events, (2) which heart rate parameter is best for prediction, and (3) what is the estimated heart rate cutoff point for the primary outcome. Methods and Results Eight thousand thirty‐one patients with acute ischemic stroke who were hospitalized within 48 hours of onset were analyzed retrospectively. Heart rates between the 4th and 7th day after onset were collected and heart rate parameters including mean, time‐weighted average, maximum, and minimum heart rate were evaluated. The primary outcome was the composite of recurrent stroke, myocardial infarction, and mortality up to 1 year after stroke onset. All heart rate parameters were associated with the primary outcome (P’s

Background Although the effect of blood pressure on poststroke outcome is well recognized, the long‐term trajectory of blood pressure after acute ischemic stroke and its influence on outcomes have not been studied well. Methods and Results We analyzed systolic blood pressure (SBP) measurements in 5514 patients with acute ischemic stroke at ≥2 of 7 prespecified time points during the first year after stroke among those enrolled in a multicenter prospective registry. Longitudinal SBPs were categorized using a group‐based trajectory model. The primary outcome was a composite of stroke recurrence, myocardial infarction, and all‐cause mortality up to 1 year after stroke. The study subjects were categorized into 4 SBP trajectory groups: low (27.0%), moderate (59.5%), persistently high (1.2%), and slowly dropping (12.4%). In the first 3 groups, SBP decreased during the first 3 to 7 days and remained steady thereafter. In the slowly dropping SBP group, SBPs decreased from 182 to 135 mm Hg during the first 30 days, then paralleled the trajectory of the moderate SBP group. Compared with the reference, the moderate SBP group, the slowly dropping SBP group was at higher risk for the primary outcome (adjusted hazard ratio [HR], 1.32; 95% CI, 1.05‒1.65) and mortality (adjusted HR, 1.35; 95% CI, 1.03‒1.78). Primary outcome rates were similarly high in the persistently high SBP group. Conclusions Four 1‐year longitudinal SBP trajectories were identified in patients with acute ischemic stroke. Patients in the slowly dropping SBP and persistently high SBP trajectory groups were prone to adverse cardiovascular outcomes after stroke.

BackgroundPreclinical data suggest circadian variation in ischemic stroke progression, with more active cell death and infarct growth in rodent models with inactive phase (daytime) than active phase (nighttime) stroke onset. We aimed to examine the association of stroke onset time with presenting severity, early neurological deterioration (END), and long-term functional outcome in human ischemic stroke.Methods and findingsIn a Korean nationwide multicenter observational cohort study from May 2011 to July 2020, we assessed circadian effects on initial stroke severity (National Institutes of Health Stroke Scale [NIHSS] score at admission), END, and favorable functional outcome (3-month modified Rankin Scale [mRS] score 0 to 2 versus 3 to 6). We included 17,461 consecutive patients with witnessed ischemic stroke within 6 hours of onset. Stroke onset time was divided into 2 groups (day-onset [06:00 to 18:00] versus night-onset [18:00 to 06:00]) and into 6 groups by 4-hour intervals. We used mixed-effects ordered or logistic regression models while accounting for clustering by hospitals. Mean age was 66.9 (SD 13.4) years, and 6,900 (39.5%) were women. END occurred in 2,219 (12.7%) patients. After adjusting for covariates including age, sex, previous stroke, prestroke mRS score, admission NIHSS score, hypertension, diabetes, hyperlipidemia, smoking, atrial fibrillation, prestroke antiplatelet use, prestroke statin use, revascularization, season of stroke onset, and time from onset to hospital arrival, night-onset stroke was more prone to END (adjusted incidence 14.4% versus 12.8%, p = 0.006) and had a lower likelihood of favorable outcome (adjusted odds ratio, 0.88 [95% CI, 0.79 to 0.98]; p = 0.03) compared with day-onset stroke. When stroke onset times were grouped by 4-hour intervals, a monotonic gradient in presenting NIHSS score was noted, rising from a nadir in 06:00 to 10:00 to a peak in 02:00 to 06:00. The 18:00 to 22:00 and 22:00 to 02:00 onset stroke patients were more likely to experience END than the 06:00 to 10:00 onset stroke patients. At 3 months, there was a monotonic gradient in the rate of favorable functional outcome, falling from a peak at 06:00 to 10:00 to a nadir at 22:00 to 02:00. Study limitations include the lack of information on sleep disorders and patient work/activity schedules.ConclusionsNight-onset strokes, compared with day-onset strokes, are associated with higher presenting neurologic severity, more frequent END, and worse 3-month functional outcome. These findings suggest that circadian time of onset is an important additional variable for inclusion in epidemiologic natural history studies and in treatment trials of neuroprotective and reperfusion agents for acute ischemic stroke.

Background: Ischemic stroke with atrial fibrillation (AF) may recur despite appropriate treatment. It may be AF-related or AF-unrelated. We compared the factors associated with AF-related and AF-unrelated recurrences among ischemic stroke patients with AF.Methods: Patients with ischemic stroke and AF were enrolled from 11 centers in Korea. Ischemic stroke recurrence was classified as AF-related if the lesion pattern was compatible with cardioembolism without significant stenosis or as AF-unrelated if the lesion was more likely due to small vessel disease or arterial stenosis. Factors associated with stroke recurrence (AF-related and AF-unrelated) were investigated.Results: Among the 2,239 patients, 115 (5.1%) experienced recurrence (75 AF-related and 40 AF-unrelated). Factors independently associated with any stroke recurrence included AF diagnosed before stroke, small subcortical infarctions, and small scattered lesions in a single vascular territory. Type of AF was associated with the type of stroke recurrence, with persistent AF being associated with AF-related stroke [hazard ratio (HR) = 2.94, 95% confidence interval (CI) 1.69–5.26; p < 0.001]. By contrast, paroxysmal AF (HR = 3.76, 95% CI 1.56–9.04; p = 0.003), AF diagnosed before stroke (HR = 2.38, 95% CI 1.19–4.55; p = 0.014), small scattered lesions in a single vascular territory (reference: corticosubcortical lesion, HR = 3.19, 95% CI 1.18–8.63; p = 0.022), and the use of antiplatelet agents (HR = 2.11, 95% CI 1.11–4.03; p = 0.024) were independently associated with AF-unrelated stroke.Conclusion: Persistent AF was more associated with AF-related stroke recurrence, whereas paroxysmal AF was more associated with AF-unrelated stroke recurrence. A scattered lesion in a single vascular territory may predict AF-unrelated stroke recurrence.

Background: Although chest radiographs have not been utilised well for classifying stroke subtypes, they could provide a plethora of information on cardioembolic stroke.This study aimed to develop a deep convolutional neural network that could diagnose cardioembolic stroke based on chest radiographs.Methods: Overall, 4,064 chest radiographs of consecutive patients with acute ischaemic stroke were collected from a prospectively maintained stroke registry. Chest radiographs were randomly partitioned into training/validation (n = 3,255) and internal test (n = 809) datasets in an 8:2 ratio. A densely connected convolutional network (ASTRO-X) was trained to diagnose cardioembolic stroke based on chest radiographs. The performance of ASTRO-X was evaluated using the area under the receiver operating characteristic curve. Gradient-weighted class activation mapping was used to evaluate the region of focus of ASTRO-X. External testing was performed with 750 chest radiographs of patients with acute ischaemic stroke from 7 hospitals.Findings: The areas under the receiver operating characteristic curve of ASTRO-X were 0.86 (95% confidence interval [CI], 0.83–0.89) and 0.82 (95% CI, 0.79–0.85) during the internal and multicentre external testing, respectively. The gradient-weighted class activation map demonstrated that ASTRO-X was focused on the area where the left atrium was located. Compared with cases predicted as non-cardioembolism by ASTRO-X, cases predicted as cardioembolism by ASTRO-X had higher left atrial volume index and lower left ventricular ejection fraction in echocardiography.Interpretation: ASTRO-X, a deep neural network developed to diagnose cardioembolic stroke based on chest radiographs, demonstrated good classification performance and biological plausibility.

Background Some emergent large vessel occlusions (ELVOs) are refractory to reperfusion because of underlying intracranial atherosclerosis (ICAS), often requiring rescue therapy (RT) with balloon angioplasty, stenting, or both. In this study, we investigate the safety, efficacy, and long‐term outcomes of RT in the setting of mechanical thrombectomy for ICAS‐related ELVO. Methods and Results We queried the databases of 10 thrombectomy‐capable centers in North America and Europe included in STAR (Stroke Thrombectomy and Aneurysm Registry). Patients with ELVO who underwent ICAS‐related RT were included. A matched sample was produced for variables of age, admission National Institute of Health Stroke Scale, Alberta Stroke Program Early CT Score, onset to groin puncture time, occlusion site, and final recanalization. Out of 3025 patients with MT, 182 (6%) patients required RT because of underlying ICAS. Balloon angioplasty was performed on 122 patients, and 117 patients had intracranial stenting. In the matched analysis, 141 patients who received RT matched to a similar number of controls. The number of thrombectomy passes was higher (3 versus 1, P

Background and Purpose Thrombectomy within 24 hours can improve outcomes in selected patients with a clinical-infarct mismatch. We devised an easy-to-use visual estimation tool that allows infarct volume estimation in centers with limited resources. Methods We identified 1,031 patients with cardioembolic or large-artery atherosclerosis infarction on diffusion-weighted images (DWIs) obtained before recanalization therapy and within 24 hours of onset, and occlusion of the internal carotid or middle cerebral artery. Acute DWIs were mapped onto a standard template and used to create visual reference maps with known lesion volumes, which were then used in a validation study (with 130 cases) against software estimates of infarct volume. Results The DWI reference map chart comprises 144 maps corresponding to 12 different infarct volumes (0.5, 1, 2, 3, 5, 7, 9, 11, 13, 15, 17, and 19 mL) in each of 12 template slices (Montreal Neurological Institute z-axis –15 to 51 mm). Infarct volume in a patient is estimated by selecting a slice with a similar infarct size at the corresponding z-axis level on the reference maps and then adding up over all slices. The method yielded good correlations to software volumetrics and was easily learned by both experienced and junior physicians, with approximately 1 to 2 minutes spent per case. The sensitivity, specificity, and accuracy for detecting threshold infarct volumes (90%). Conclusions We developed easy-to-use reference maps that allow prompt and reliable visual estimation of infarct volumes for triaging patients to thrombectomy in acute stroke.

Abstract Background Futile reperfusion (poor functional status despite successful reperfusion) was observed in up to 67% of patients enrolled in recent endovascular treatment (EVT) clinical trials. We investigated the impact of baseline stroke severity on both futile reperfusion and therapeutic benefit of successful EVT. Methods Using a prospective multicenter stroke registry, we identified consecutive ischemic stroke patients with anterior circulation large artery occlusion, who were reperfused successfully by EVT (Thrombolysis in Cerebral Infarction grade 2b–3). The rate of futile reperfusion was assessed across the initial National Institutes of Health Stroke Scale (NIHSS) scores. The frequency of poor outcomes (modified Rankin scale [mRS] 3–6) according to NIHSS scores was compared between patients revascularized successfully by EVT and those who did not receive EVT, after standardizing for age. Results Among 21,591 patients with ischemic stroke, 972 (4.5%) received EVT within 12 h of onset, including 440 who met study eligibility criteria. Futile reperfusion was observed in 226 of the 440 study-eligible patients (51.4%) and was associated with stroke severity: 20.9% in NIHSS scores ≤5, 34.6% in 6–10, 58.9% in 11–20, and 63.8% in > 20 (p 20. Conclusions EVT is more beneficial with increasing stroke severity, although futile reperfusion also increases with higher stroke severity.

Despite the great socioeconomic burden of stroke, there have been few reports of stroke statistics in Korea. In this scenario, the Epidemiologic Research Council of the Korean Stroke Society launched the “Stroke Statistics in Korea” project, aimed at writing a contemporary, comprehensive, and representative report on stroke epidemiology in Korea. This report contains general statistics of stroke, prevalence of behavioral and vascular risk factors, stroke characteristics, pre-hospital system of care, hospital management, quality of stroke care, and outcomes. In this report, we analyzed the most up-to-date and nationally representative databases, rather than performing a systematic review of existing evidence. In summary, one in 40 adults are patients with stroke and 232 subjects per 100,000 experience a stroke event every year. Among the 100 patients with stroke in 2014, 76 had ischemic stroke, 15 had intracerebral hemorrhage, and nine had subarachnoid hemorrhage. Stroke mortality is gradually declining, but it remains as high as 30 deaths per 100,000 individuals, with regional disparities. As for stroke risk factors, the prevalence of smoking is decreasing in men but not in women, and the prevalence of alcohol drinking is increasing in women but not in men. Population-attributable risk factors vary with age. Smoking plays a role in young-aged individuals, hypertension and diabetes in middle-aged individuals, and atrial fibrillation in the elderly. About four out of 10 hospitalized patients with stroke are visiting an emergency room within 3 hours of symptom onset, and only half use an ambulance. Regarding acute management, the proportion of patients with ischemic stroke receiving intravenous thrombolysis and endovascular treatment was 10.7% and 3.6%, respectively. Decompressive surgery was performed in 1.4% of patients with ischemic stroke and in 28.1% of those with intracerebral hemorrhage. The cumulative incidence of bleeding and fracture at 1 year after stroke was 8.9% and 4.7%, respectively. The direct costs of stroke were about ₩1.68 trillion (KRW), of which ₩1.11 trillion were for ischemic stroke and ₩540 billion for hemorrhagic stroke. The great burden of stroke in Korea can be reduced through more concentrated efforts to control major attributable risk factors for age and sex, reorganize emergency medical service systems to give patients with stroke more opportunities for reperfusion therapy, disseminate stroke unit care, and reduce regional disparities. We hope that this report can contribute to achieving these tasks.

Background It remains unclear whether physicians' attitudes toward timely management of elevated blood pressure affect the risk of stroke recurrence. Methods and Results From a multicenter stroke registry database, we identified 2933 patients with acute ischemic stroke who were admitted to participating centers in 2011, survived at the 1‐year follow‐up period, and returned to outpatient clinics ≥2 times after discharge. As a surrogate measure of physicians' attitude, individual treatment intensification (TI) scores were calculated by dividing the difference between the frequencies of observed and expected medication changes by the frequency of clinic visits and categorizing them into 5 groups. The association between TI groups and the recurrence of stroke within 1 year was analyzed using hierarchical frailty models, with adjustment for clustering within each hospital and relevant covariates. Mean±SD of the TI score was −0.13±0.28. The TI score groups were significantly associated with increased risk of recurrent stroke compared with Group 3 (TI score range, −0.25 to 0); Group 1 (range, −1 to −0.5), adjusted hazard ratio (HR) 13.43 (95% CI, 5.95–30.35); Group 2 (range, −0.5 to −0.25), adjusted HR 4.59 (95% CI, 2.01–10.46); and Group 4 (TI score 0), adjusted HR 6.60 (95% CI, 3.02–14.45); but not with Group 5 (range, 0–1), adjusted HR 1.68 (95% CI, 0.62–4.56). This elevated risk in the lowest TI score groups persisted when confining analysis to those with hypertension, history of blood pressure‐lowering medication, no atrial fibrillation, and regular clinic visits and stratifying the subjects by functional capacity at discharge. Conclusions A low TI score, which implies physicians' therapeutic inertia in blood pressure management, was associated with a higher risk of recurrent stroke. The TI score may be a useful performance indicator in the outpatient clinic setting to prevent recurrent stroke.

Background The long‐term incidence of acute myocardial infarction (AMI) in patients with acute ischemic stroke (AIS) has not been well defined in large cohort studies of various race‐ethnic groups. Methods and Results A prospective cohort of patients with AIS who were registered in a multicenter nationwide stroke registry (CRCS‐K [Clinical Research Collaboration for Stroke in Korea] registry) was followed up for the occurrence of AMI through a linkage with the National Health Insurance Service claims database. The 5‐year cumulative incidence and annual risk were estimated according to predefined demographic subgroups, stroke subtypes, a history of coronary heart disease (CHD), and known risk factors of CHD. A total of 11 720 patients with AIS were studied. The 5‐year cumulative incidence of AMI was 2.0%. The annual risk was highest in the first year after the index event (1.1%), followed by a much lower annual risk in the second to fifth years (between 0.16% and 0.27%). Among subgroups, annual risk in the first year was highest in those with a history of CHD (4.1%) compared with those without a history of CHD (0.8%). The small‐vessel occlusion subtype had a much lower incidence (0.8%) compared with large‐vessel occlusion (2.2%) or cardioembolism (2.4%) subtypes. In the multivariable analysis, history of CHD (hazard ratio, 2.84; 95% CI, 2.01–3.93) was the strongest independent predictor of AMI after AIS. Conclusions The incidence of AMI after AIS in South Korea was relatively low and unexpectedly highest during the first year after stroke. CHD was the most substantial risk factor for AMI after stroke and conferred an approximate 5‐fold greater risk.

In this paper, a self-threshold voltage (Vth) compensated Radio Frequency to Direct Current (RF-DC) converter operating at 900 MHz and 2.4 GHz is proposed for RF energy harvesting applications. The threshold voltage of the rectifying devices is compensated by the bias voltage generated by the auxiliary transistors and output DC voltage. The auxiliary transistors compensate the threshold voltage (Vth) of the PMOS rectifying device while the threshold voltage (Vth) of the NMOS rectifying device is compensated by the output DC voltage. The proposed RF-DC converter was implemented in 180 nm Complementary Metal-Oxide Semiconductor (CMOS) technology. The experimental results show that the proposed design achieves better performance at both 900 MHz and 2.4 GHz frequencies in terms of PCE, output voltage, sensitivity, and effective area. The peak power conversion efficiency (PCE) of 38.5% at −12 dBm across a 1 MΩ load for 900 MHz frequency was achieved. Similarly, for 2.4 GHz frequency, the proposed circuit achieves a peak PCE of 26.5% at −6 dBm across a 1 MΩ load. The proposed RF-DC converter circuit shows a sensitivity of −20 dBm across a 1 MΩ load and produces a 1 V output DC voltage.

BACKGROUND:Identifying acute ischemic stroke (AIS) among potential stroke cases is crucial for stroke research based on claims data. However, the accuracy of using the diagnostic codes of the International Classification of Diseases 10th revision was less than expected. METHODS:From the National Health Insurance Service (NHIS) claims data, stroke cases admitted to the hospitals participating in the multicenter stroke registry (Clinical Research Collaboration for Stroke in Korea, CRCS-K) during the study period with principal or additional diagnosis codes of I60-I64 on the 10th revision of International Classification of Diseases were extracted. The datasets were randomly divided into development and validation sets with a ratio of 7:3. A stroke identification algorithm using the claims data was developed and validated through the linkage between the extracted datasets and the registry database. RESULTS:Altogether, 40,443 potential cases were extracted from the NHIS claims data, of which 31.7% were certified as AIS through linkage with the CRCS-K database. We selected 17 key identifiers from the claims data and developed 37 conditions through combinations of those key identifiers. The key identifiers comprised brain CT, MRI, use of tissue plasminogen activator, endovascular treatment, carotid endarterectomy or stenting, antithrombotics, anticoagulants, etc. The sensitivity, specificity, and diagnostic accuracy of the algorithm were 81.2%, 82.9%, and 82.4% in the development set, and 80.2%, 82.0%, and 81.4% in the validation set, respectively. CONCLUSIONS:Our stroke identification algorithm may be useful to grasp stroke burden in Korea. However, further efforts to refine the algorithm are necessary.

BACKGROUND AND PURPOSE:We hypothesized that admission insular infarcts could be associated with early neurological deterioration (END) in acute minor stroke with large vessel occlusion. METHODS:Using acute and follow-up diffusion-weighted imaging (DWI), we assessed insular involvement including the percent insular ribbon infarction (PIRI) scores and follow-up lesion patterns in acute minor stroke (NIHSS ≤5) with MCA/ICA occlusion. Follow-up lesion patterns were classified as swelling, new lesions, or infarct growth. END was defined as any increase in the NIHSS score. RESULTS:Among 166 patients (age: 66±12 y, 60.8% male), 82 (49.4%) had insular lesions on baseline DWI, and 64 (38.6%) had PIRI scores ≥2. On follow-up DWI, infarct growths, new lesions, and swelling were observed in 34.9%, 69.9%, and 29.5% of patients. Infarct growths were significantly more frequent in patients with insular infarcts (43.9%), especially those with a PIRI score of 2 (54.8%), than in patients without insular infarcts (p = 0.02). While END was not significantly different in patients with and without insular lesions, insular lesions were independently associated with infarct growths (OR 2.18, 95% CI 1.12-4.26, p = 0.02) and END due to infarct growth (OR 2.54, 95% CI 1.12-5.76, p = 0.03), particularly in those with PIRI scores ≥2. CONCLUSION:In acute minor stroke with MCA/ICA occlusion, insular lesions on admission DWI, especially in patients with PIRI scores ≥2, were more likely to exhibit infarct growth and END due to infarct growth. This finding may help identify patients with higher risks of clinical worsening following acute minor stroke with large vessel occlusion.

Background There is insufficient evidence on the effect of statins, particularly high‐intensity statins, in patients with acute ischemic stroke and atrial fibrillation. We investigated the impact of statins on the outcomes in these patients, including those who might be vulnerable to statin therapy and those without clinical atherosclerotic cardiovascular diseases. Methods and Results A total of 2153 patients with acute ischemic stroke and atrial fibrillation were enrolled in the present nationwide, multicenter, cohort study. The primary composite end point was the occurrence of net adverse clinical and cerebral events (NACCE; death from any cause, stroke, acute coronary syndrome, or major bleeding) over a 3‐year period based on statin intensity. NACCE rates were lower in patients receiving low‐ to moderate‐intensity (adjusted hazard ratio 0.64; 95% CI: 0.52‐0.78) and high‐intensity statins (hazard ratio 0.51; 95% CI 0.40‐0.66) than in those not receiving statin therapy. High‐intensity statins were associated with a lower risk for NACCE than low‐ to moderate‐intensity statins (hazard ratio 0.76; 95% CI 0.59‐0.96). Subgroup analyses showed that the differences in hazard ratio for 3‐year NACCE favored statin use across all subgroups, including older patients, those with low cholesterol levels, patients receiving anticoagulants, and patients without clinical atherosclerotic cardiovascular diseases. Magnified benefits of high‐intensity statins compared with low‐ to moderate‐intensity statins were observed in patients who underwent revascularization therapy and those under 75 years of age. Conclusions Statins, particularly high‐intensity statins, could reduce the risk for NACCE in patients with acute ischemic stroke and atrial fibrillation; this needs to be further explored in randomized controlled trials.

Background Off‐hour presentation can affect treatment delay and clinical outcomes in endovascular therapy (EVT) for acute ischemic stroke. We aimed to examine the treatment delays and clinical outcomes of EVT between on‐ and off‐hour admission and to evaluate the effect of hospital procedure volume and the number of neurointerventionalists on off‐hour EVT. Methods and Results From a multicenter registry, we identified patients who were treated with EVT within 12 hours of symptom. Annual hospital procedure volume was divided as low (60). The effect of the number of neurointerventionalists and annual hospital procedure volume on clinical outcome was estimated by the generalized estimation equation. Of the 31 133 stroke patients, 1564 patients met the eligibility criteria (mean age: 69±12 years; median baseline National Institutes of Health stroke scale score, 15 [interquartile range, 10–19]). Of 1564 patients, 893 (57.1%) arrived during off‐hour. The off‐hour patients had greater median door‐to‐puncture time (110 versus 95 minutes; P

Background and aims: Atrial fibrillation (AF) is a major cause of ischemic stroke; however, detailed clinical data and prognostic factors for stroke patients with AF are lacking in Korea. We aimed to investigate clinical information and factors associated with functional outcomes of stroke patients with AF from the Korean nationwide ATrial fibrillaTion EvaluatioN regisTry in Ischemic strOke patieNts (K-ATTENTION) database.Methods: From January 2013 to December 2015, consecutive clinical information from acute stroke patients with AF or history of AF was collected from 11 centers in Korea. Collected data included demographics, risk factors, pre-stroke medication, stroke severity, stroke subtypes, concomitant cerebral atherosclerosis, brain image findings, recanalization therapy, discharge medication, and functional outcome at 3 months after index stroke.Results: A total of 3,213 stroke patients (mean age, 73.6 ± 9.8 years; female, 48.6%) were included. The mean CHA2DS2-VASc score was 4.9. Among the 1,849 (57.5%) patients who had brain image and functional outcome data, poor outcome (modified Rankin scale > 2) was noted in 53.1% (981/1,849) of patients. After adjusting for age, sex, and variables that had a p < 0.05 in univariate analysis or well-known factors for functional outcome, presence of asymptomatic extracranial cerebral atherosclerosis [odd ratio (OR): 1.96, 95% confidence interval (CI): 1.36–2.82, p = 0.001] and less frequent prior stroke statin intake (OR: 0.69, 95% CI: 0.49–0.98, p = 0.038) were associated with poor functional outcome.Conclusion: Our results suggest that presence of non-relevant extracranial cerebral atherosclerosis may affect poor functional outcome and prior stroke statin therapy may be feasible in Korean stroke patients with AF.

Background and Purpose About 30%-40% of stroke patients are taking antiplatelet at the time of their strokes, which might increase the risk of symptomatic intracranial hemorrhage (SICH) with intravenous tissue plasminogen activator (IV-TPA) therapy. We aimed to assess the effect of prestroke antiplatelet on the SICH risk and functional outcome in Koreans treated with IV-TPA. Methods From a prospective stroke registry, we identified patients treated with IV-TPA between October 2009 and November 2014. Prestroke antiplatelet use was defined as taking antiplatelet within 7 days before the stroke onset. The primary outcome was SICH. Secondary outcomes were discharge modified Rankin Scale (mRS) score and in-hospital mortality. Results Of 1,715 patients treated with IV-TPA, 441 (25.7%) were on prestroke antiplatelet. Prestroke antiplatelet users versus non-users were more likely to be older, to have multiple vascular risk factors. Prestroke antiplatelet use was associated with an increased risk of SICH (5.9% vs. 3.0%; adjusted odds ratio [OR] 1.79 [1.05-3.04]). However, at discharge, the two groups did not differ in mRS distribution (adjusted OR 0.90 [0.72-1.14]), mRS 0-1 outcome (34.2% vs. 33.7%; adjusted OR 1.27 [0.94-1.72), mRS 0-2 outcome (52.4% vs. 52.9%; adjusted OR 1.21 [0.90-1.63]), and in-hospital mortality (6.1% vs. 4.2%; adjusted OR 1.19 [0.71-2.01]). Conclusions Despite an increased risk of SICH, prestroke antiplatelet users compared to non-users had comparable functional outcomes and in-hospital mortality with IV-TPA therapy. Our results support the use of IV-TPA in eligible patients taking antiplatelet therapy before their stroke onset.

Background White matter hyperintensities (WMHs) are commonly asymmetric between hemispheres but for unknown reasons. We investigated asymmetric WMHs associated with lacunar infarcts. Methods and Results A total of 267 consecutive patients with small first‐ever supratentorial infarcts (≤20 mm) were included. None had a relevant vascular stenosis. WMH asymmetry was measured based on the hemispheric difference of a modified Scheltens scale score (≥3 defined as asymmetric). We analyzed the association of the hemispheric WMH asymmetry with old silent lacunar infarcts or acute lacunar infarcts. We compared lesion frequency maps between groups and generated t‐statistics maps. The mean age of patients was 64 years, and 63% were men. Asymmetric WMH was more than 3‐fold as frequent (P