Selective Enhancement of Viewing Angle Characteristics and Light Extraction Efficiency of Blue Thermally Activated Delayed Fluorescence Organic Light-Emitting Diodes through an Easily Tailorable Si3N4 Nanofiber Structure.

We selectively improved the viewing angle characteristics and light extraction efficiency of blue thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs) by tailoring a nanofiber-shaped Si3N4 layer, which was used as an internal scattering layer. The diameter of the polymer nanofibers changed according to the mass ratio of polyacrylonitrile (PAN) and poly(methyl methacrylate) (PMMA) in the polymer solution for electrospinning. The Si3N4 nanofiber (SNF) structure was fabricated by etching an Si3N4 film using the PAN/PMMA nanofiber as a mask, making it easier to adjust parameters, such as the diameter, open ratio, and height, even though the SNF structure was randomly shaped. The SNF structures exhibited lower transmittance and higher haze with increasing diameter, showing little correlation with their height. However, all the structures demonstrated a total transmittance of over 80%. Finally, by applying the SNF structures to the blue TADF OLEDs, the external quantum efficiency was increased by 15.6%. In addition, the current and power efficiencies were enhanced by 23.0% and 25.6%, respectively. The internal light-extracting SNF structure also exhibited a synergistic effect with the external light-extracting structure. Furthermore, when the viewing angle changed from 0° to 60°, the peak wavelength and CIE coordinate shift decreased from 20 to 6 nm and from 0.0561 to 0.0243, respectively. These trends were explained by the application of Snell's law to the light path and were ultimately validated through finite-difference time-domain simulations.

Trends in Dual Antiplatelet Therapy of Aspirin and Clopidogrel and Outcomes in Ischemic Stroke Patients Noneligible for POINT/CHANCE Trial Treatment.

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<0.001). From 2011 to 2022, clinical outcomes nonsignificantly improved, with an average relative risk reduction of 2%/y for the composite of stroke, myocardial infarction, and all-cause mortality, both among patients treated with DAPT-AC and patients treated with other antiplatelets. CONCLUSIONS: Use of DAPT-AC in stroke patients with stroke ineligible for recent DAPT clinical trials increased markedly and steadily after CHANCE publication in 2013, reaching deployment in nearly 4 of every 5 patients by 2022. The secondary prevention in patients with ischemic stroke seems to be gradually improving, possibly due to the enhancement of risk factor control.

Regional Disparities in Prehospital Delay of Acute Ischemic Stroke: The Korean Stroke Registry.

BACKGROUND: Late hospital arrival keeps patients with stroke from receiving recanalization therapy and is associated with poor outcomes. This study used a nationwide acute stroke registry to investigate the trends and regional disparities in prehospital delay and analyze the significant factors associated with late arrivals. METHODS: Patients with acute ischemic stroke or transient ischemic attack between January 2012 and December 2021 were included. The prehospital delay was identified, and its regional disparity was evaluated using the Gini coefficient for nine administrative regions. Multivariate models were used to identify factors significantly associated with prehospital delays of >4.5 h. RESULTS: A total of 144,014 patients from 61 hospitals were included. The median prehospital delay was 460 min (interquartile range, 116-1912), and only 36.8% of patients arrived at hospitals within 4.5 h. Long prehospital delays and high regional inequality (Gini coefficient > 0.3) persisted throughout the observation period. After adjusting for confounders, age > 65 years old (adjusted odds ratio [aOR] = 1.23; 95% confidence interval [CI], 1.19-1.27), female sex (aOR = 1.09; 95% CI, 1.05-1.13), hypertension (aOR = 1.12; 95% CI, 1.08-1.16), diabetes mellitus (aOR = 1.38; 95% CI, 1.33-1.43), smoking (aOR = 1.15, 95% CI, 1.11-1.20), premorbid disability (aOR = 1.44; 95% CI, 1.37-1.52), and mild stroke severity (aOR = 1.55; 95% CI, 1.50-1.61) were found to independently predict prehospital delays of >4.5 h. CONCLUSION: Prehospital delays were lengthy and had not improved in Korea, and there was a high regional disparity. To overcome these inequalities, a deeper understanding of regional characteristics and further research is warranted to address the vulnerabilities identified.

Use of a commercial artificial intelligence-based mammography analysis software for improving breast ultrasound interpretations.

OBJECTIVES: To evaluate the use of a commercial artificial intelligence (AI)-based mammography analysis software for improving the interpretations of breast ultrasound (US)-detected lesions. METHODS: A retrospective analysis was performed on 1109 breasts that underwent both mammography and US-guided breast biopsy. The AI software processed mammograms and provided an AI score ranging from 0 to 100 for each breast, indicating the likelihood of malignancy. The performance of the AI score in differentiating mammograms with benign outcomes from those revealing cancers following US-guided breast biopsy was evaluated. In addition, prediction models for benign outcomes were constructed based on clinical and imaging characteristics with and without AI scores, using logistic regression analysis. RESULTS: The AI software had an area under the receiver operating characteristics curve (AUROC) of 0.79 (95% CI, 0.79-0.82) in differentiating between benign and cancer cases. The prediction models that did not include AI scores (non-AI model), only used AI scores (AI-only model), and included AI scores (integrated model) had AUROCs of 0.79 (95% CI, 0.75-0.83), 0.78 (95% CI, 0.74-0.82), and 0.85 (95% CI, 0.81-0.88) in the development cohort, and 0.75 (95% CI, 0.68-0.81), 0.82 (95% CI, 0.76-0.88), and 0.84 (95% CI, 0.79-0.90) in the validation cohort, respectively. The integrated model outperformed the non-AI model in the development and validation cohorts (p < 0.001 for both). CONCLUSION: The commercial AI-based mammography analysis software could be a valuable adjunct to clinical decision-making for managing US-detected breast lesions. CLINICAL RELEVANCE STATEMENT: The commercial AI-based mammography analysis software could potentially reduce unnecessary biopsies and improve patient outcomes. KEY POINTS: • Breast US has high rates of false-positive interpretations. • A commercial AI-based mammography analysis software could distinguish mammograms having benign outcomes from those revealing cancers after US-guided breast biopsy. • A commercial AI-based mammography analysis software may improve interpretations for breast US-detected lesions.

Risk of cardiovascular disease with high-dose versus low-dose use of non-steroidal anti-inflammatory drugs in ankylosing spondylitis.

OBJECTIVE: To investigate the risk of cardiovascular disease (CVD) associated with increasing dose of a non-steroidal anti-inflammatory drug (NSAID) in patients with ankylosing spondylitis (AS). METHODS: Using the Korean National Health Insurance database, patients newly diagnosed with AS without prior CVD between 2010 and 2018 were included in this nationwide cohort study. The primary outcome was CVD, a composite outcome of ischaemic heart disease, stroke or congestive heart failure. Exposure to NSAIDs was evaluated using a time-varying approach. The dose of NSAIDs was considered in each exposure period. Cox proportional hazard regression was used to investigate the risk of CVD associated with NSAID use. RESULTS: Of the 19 775 patients (mean age, 36 years; 75% were male), 19 706 received NSAID treatment. During follow-up period of 98 290 person-years, 1663 cases of CVD occurred including 1157 cases of ischaemic heart disease, 301 cases of stroke and 613 cases of congestive heart failure. Increasing dose of NSAIDs was associated with incident CVD after adjusting for confounders (adjusted HR (aHR) 1.10; 95% CI 1.08 to 1.13). Specifically, increasing dose of NSAIDs was associated with incident ischaemic heart disease (aHR 1.08; 95% CI 1.05 to 1.11), stroke (aHR 1.09; 95% CI 1.04 to 1.15) and congestive heart failure (aHR 1.12; 95% CI 1.08 to 1.16). The association between NSAID dose and higher CVD risk was consistent in different subgroups. CONCLUSION: In a real-world AS cohort, higher dose of NSAID treatment was associated with a higher risk of CVD, including ischaemic heart disease, stroke and congestive heart failure.

Network analysis of stroke systems of care in Korea.

Background: The landscape of stroke care has shifted from stand-alone hospitals to cooperative networks among hospitals. Despite the importance of these networks, limited information exists on their characteristics and functional attributes. Methods: We extracted patient-level data on acute stroke care and hospital connectivity by integrating national stroke audit data with reimbursement claims data. We then used this information to transform interhospital transfers into a network framework, where hospitals were designated as nodes and transfers as edges. Using the Louvain algorithm, we grouped densely connected hospitals into distinct stroke care communities. The quality and characteristics in given stroke communities were analysed, and their distinct types were derived using network parameters. The clinical implications of this network model were also explored. Results: Over 6 months, 19 113 patients with acute ischaemic stroke initially presented to 1009 hospitals, with 3114 (16.3%) transferred to 246 stroke care hospitals. These connected hospitals formed 93 communities, with a median of 9 hospitals treating a median of 201 patients. Derived communities demonstrated a modularity of 0.904, indicating a strong community structure, highly centralised around one or two hubs. Three distinct types of structures were identified: single-hub (n=60), double-hub (n=22) and hubless systems (n=11). The endovascular treatment rate was highest in double-hub systems, followed by single-hub systems, and was almost zero in hubless systems. The hubless communities were characterised by lower patient volumes, fewer hospitals, no hub hospital and no stroke unit. Conclusions: This network analysis could quantify the national stroke care system and point out areas where the organisation and functionality of acute stroke care could be improved.

Influence of additional prophylactic oral antibiotics during mechanical bowel preparation on surgical site infection in patients receiving colorectal surgery.

BACKGROUND: Prophylactic antibiotics (PAs) are standard for preventing surgical site infections (SSIs) post-colorectal surgery. This study aims to compare the effect of additional empiric oral antibiotics (OAs) alongside routine PAs to identify SSI risk factors. METHODS: A retrospective observatory analysis was conducted from January 2019 to December 2022 at Asan Medical Center, Seoul, Korea. The cohort was divided into two groups: PA given 1 h before surgery and discontinued within 24 h, and OA administered empiric OAs during mechanical bowel preparation in addition to PA. RESULTS: From a total of 6736 patients, 3482 were in the PA group and 3254 in the OA group. SSI incidence showed no significant intergroup difference (p = 0.374) even after propensity score matching (p = 0.338). The multivariable analysis revealed male sex [odds ratio (OR): 2.153, 95% confidence interval (CI): 1.626-2.852, and p = 0.001], open surgery (OR: 3.335, 95% CI: 2.456-4.528, and p = 0.001), dirty wound (OR: 2.171, 95% CI: 1.256-3.754, and p = 0.006), and an operation time of more than 145 min (OR: 2.110, 95% CI: 1.324-3.365, and p = 0.002) as SSI risk factors. In rectal surgery subgroup, OA demonstrated a protective effect against SSI (OR: 0.613, 95% CI: 0.408-0.922, and p = 0.019) and in laparoscopic approach (OR: 0.626, 95% CI: 0.412-0.952, and p = 0.028). CONCLUSIONS: OA did not affect SSI incidence in colorectal surgeries. Male sex, open surgery, dirty wounds, and longer operation time were risk factors for SSI. However, for rectal and laparoscopic surgery, OA was a protective factor for SSI.

Quantitative Coronary Angiography vs Intravascular Ultrasonography to Guide Drug-Eluting Stent Implantation: A Randomized Clinical Trial.

Importance: Although intravascular ultrasonography (IVUS) guidance promotes favorable outcomes after percutaneous coronary intervention (PCI), many catheterization laboratories worldwide lack access. Objective: To investigate whether systematic implementation of quantitative coronary angiography (QCA) to assist angiography-guided PCI could be an alternative strategy to IVUS guidance during stent implantation. Design, Setting, and Participants: This randomized, open-label, noninferiority clinical trial enrolled adults (aged ≥18 years) with chronic or acute coronary syndrome and angiographically confirmed native coronary artery stenosis requiring PCI. Patients were enrolled in 6 cardiac centers in Korea from February 23, 2017, to August 23, 2021, and follow-up occurred through August 25, 2022. All principal analyses were performed according to the intention-to-treat principle. Interventions: After successful guidewire crossing of the first target lesion, patients were randomized in a 1:1 ratio to receive either QCA- or IVUS-guided PCI. Main Outcomes and Measures: The primary outcome was target lesion failure at 12 months, defined as a composite of cardiac death, target vessel myocardial infarction, or ischemia-driven target lesion revascularization. The trial was designed assuming an event rate of 8%, with the upper limit of the 1-sided 97.5% CI of the absolute difference in 12-month target lesion failure (QCA-guided PCI minus IVUS-guided PCI) to be less than 3.5 percentage points for noninferiority. Results: The trial included 1528 patients who underwent PCI with QCA guidance (763; mean [SD] age, 64.1 [9.9] years; 574 males [75.2%]) or IVUS guidance (765; mean [SD] age, 64.6 [9.5] years; 622 males [81.3%]). The post-PCI mean (SD) minimum lumen diameter was similar between the QCA- and IVUS-guided PCI groups (2.57 [0.55] vs 2.60 [0.58] mm, P = .26). Target lesion failure at 12 months occurred in 29 of 763 patients (3.81%) in the QCA-guided PCI group and 29 of 765 patients (3.80%) in the IVUS-guided PCI group (absolute risk difference, 0.01 percentage points [95% CI, -1.91 to 1.93 percentage points]; hazard ratio, 1.00 [95% CI, 0.60-1.68]; P = .99). There was no difference in the rates of stent edge dissection (1.2% vs 0.7%, P = .25), coronary perforation (0.2% vs 0.4%, P = .41), or stent thrombosis (0.53% vs 0.66%, P = .74) between the QCA- and IVUS-guided PCI groups. The risk of the primary end point was consistent regardless of subgroup, with no significant interaction. Conclusions and Relevance: Findings of this randomized clinical trial indicate that QCA and IVUS guidance during PCI showed similar rates of target lesion failure at 12 months. However, due to the lower-than-expected rates of target lesion failure in this trial, the findings should be interpreted with caution. Trial Registration: ClinicalTrials.gov Identifier: NCT02978456.

The impact of statin treatment duration on the risk of new-onset diabetes mellitus and recurrent vascular events in ischemic stroke patients: a linked data analysis.

INTRODUCTION: Although statin therapy reduces cardiovascular events, statin use is associated with the risk of new-onset diabetes mellitus (NODM). Using a linked dataset, we evaluated the effect of statin treatment on vascular outcomes and NODM development in patients with ischemic stroke. METHODS: From the dataset, we identified 20,250 patients with acute ischemic stroke who had neither a prior history of DM nor a previous history of statin use before the index stroke. Patients were divided into statin users and non-users. The outcomes were NODM and vascular outcomes, including recurrent ischemic stroke and acute myocardial infarction (AMI). RESULTS: Of the 20,250 patients, 13,706 (67.7%) received statin treatment after the index stroke. For the risk of NODM, a time-response relationship was observed between the use of statins and NODM; a longer post-stroke follow-up duration substantially increased the risk of NODM. Among those with ischemic stroke exceeding 3 years, statin users had an approximately 1.7-fold greater risk of NODM than statin non-users. Statin therapy significantly reduced the risk of recurrent ischemic stroke by 54% (HR 0.46, 95% CI, 0.43-0.50, P < 0.001) across all stroke subtypes. CONCLUSION: Statin therapy following ischemic stroke increased the occurrence of NODM in patients over a period of 3 years. Despite the increased risk of NODM, statin therapy shows a beneficial effect in reducing major cardiovascular events such as recurrent ischemic stroke and AMI in patients with ischemic stroke.

Efficacy of Endovascular Thrombectomy in Acute Basilar Artery Occlusion with Low PC-ASPECTS: A Nationwide Prospective Registry-Based Study.

OBJECTIVE: We evaluated the efficacy of endovascular thrombectomy (EVT) on the functional outcome of patients with acute basilar artery occlusion and low posterior circulation acute stroke prognosis early computed tomography score (PC-ASPECTS). METHODS: We identified patients with acute ischemic stroke due to basilar artery occlusion and PC-ASPECTS of 6 or less, presenting within 24 h between August 2008 and April 2022. The primary outcome was a favorable functional outcome, defined as a modified Rankin Scale (mRS) score of 0-3 at 90 days. The secondary outcomes included an mRS score of 0-2, a favorable shift in the ordinal mRS scale, the occurrence of symptomatic intracranial hemorrhage (sICH), and mortality at 90 days. We compared the outcome of patients treated with EVT and those without EVT, using the inverse probability of treatment weighting methods. RESULTS: Out of 566 patients, 55.5% received EVT. In the EVT group, 106 (33.8%) achieved favorable outcomes, compared to 56 patients (22.2%) in the conservative group. EVT significantly increased the likelihood of achieving a favorable outcome compared to conservative treatment (relative risk [RR] 1.39, 95% confidence interval [CI], 1.11-1.74, p = 0.004). EVT was associated with a favorable shift in the mRS (RR 1.85, 95% CI, 1.49-2.29, p < 0.001) and reduced mortality without an increase in the risk of sICH. It did not have an impact on achieving an mRS score of 0-2. INTERPRETATION: Patients with acute basilar artery occlusion and a PC-ASPECTS of 6 or less might benefit from EVT without an increasing sICH. ANN NEUROL 2024;95:788-799.

Secular Trends in Outcomes and Impact of Novel Oral Anticoagulants in Atrial Fibrillation-Related Acute Ischemic Stroke.

BACKGROUND: Novel oral anticoagulants (NOACs) are currently recommended for the secondary prevention of stroke in patients with acute ischemic stroke (AIS) accompanied by atrial fibrillation (AF). However, the impact of NOACs on clinical outcomes in real-world practice remains ambiguous. This study analyzes the trend of clinical events in patients with AF-related AIS and determines how much the introduction of NOACs has mediated this trend. METHODS: We identified patients with AIS and AF between January 2011 and December 2019 using a multicenter stroke registry. Annual rates of NOAC prescriptions and clinical events within 1 year were evaluated. The primary outcome was a composite of recurrent stroke, myocardial infarction, and all-cause mortality. To assess the mediation effect of NOACs on the relationship between the calendar year and these outcomes, we used natural effect models and conducted exposure-mediator, exposure-outcome, and mediator-outcome analyses using multivariable regression models or accelerated failure time models, adjusting for potential confounders. RESULTS: Among the 12 977 patients with AF-related AIS, 12 500 (average age: 74.4 years; 51.3% male) were analyzed after excluding cases of valvular AF. Between 2011 and 2019, there was a significant decrease in the 1-year incidence of the primary composite outcome from 28.3% to 21.7%, while the NOAC prescription rate increased from 0% to 75.6%. A 1-year increase in the calendar year was independently associated with delayed occurrence of the primary outcome (adjusted time ratio, 1.10 [95% CI, 1.07-1.14]) and increased NOAC prescription (adjusted odds ratio, 2.20 [95% CI, 2.14-2.27]). Increased NOAC prescription was associated with delayed occurrence of the primary outcome (adjusted time ratio, 3.82 [95% CI, 3.17 to 4.61]). Upon controlling for NOAC prescription (mediator), the calendar year no longer influenced the primary outcome (adjusted time ratio, 0.97 [95% CI, 0.94-1.00]). This suggests that NOAC prescription mediates the association between the calendar year and the primary outcome. CONCLUSIONS: Our study highlights a temporal reduction in major clinical events or death in Korean patients with AF-related AIS, mediated by increased NOAC prescription, emphasizing NOAC use in this population.

Brain Frailty and Outcomes of Acute Minor Ischemic Stroke With Large-Vessel Occlusion.

BACKGROUND AND PURPOSE: The influence of imaging features of brain frailty on outcomes were investigated in acute ischemic stroke patients with minor symptoms and large-vessel occlusion (LVO). METHODS: This was a retrospective analysis of a prospective, multicenter, nationwide registry of consecutive patients with acute (within 24 h) minor (National Institutes of Health Stroke Scale score=0-5) ischemic stroke with anterior circulation LVO (acute minor LVO). Brain frailty was stratified according to the presence of an advanced white-matter hyperintensity (WMH) (Fazekas grade 2 or 3), silent/old brain infarct, or cerebral microbleeds. The primary outcome was a composite of stroke, myocardial infarction, and all-cause mortality within 1 year. RESULTS: In total, 1,067 patients (age=67.2±13.1 years [mean±SD], 61.3% males) were analyzed. The proportions of patients according to the numbers of brain frailty burdens were as follows: no burden in 49.2%, one burden in 30.0%, two burdens in 17.3%, and three burdens in 3.5%. In the Cox proportional-hazards analysis, the presence of more brain frailty burdens was associated with a higher risk of 1-year primary outcomes, but after adjusting for clinically relevant variables there were no significant associations between burdens of brain frailty and 1-year vascular outcomes. For individual components of brain frailty, an advanced WMH was independently associated with an increased risk of 1-year primary outcomes (adjusted hazard ratio [aHR]=1.33, 95% confidence interval [CI]=1.03-1.71) and stroke (aHR=1.32, 95% CI=1.00-1.75). CONCLUSIONS: The baseline imaging markers of brain frailty were common in acute minor ischemic stroke patients with LVO. An advanced WMH was the only frailty marker associated with an increased risk of vascular events. Further research is needed into the association between brain frailty and prognosis in patients with acute minor LVO.

Association between Rapid Ventricular Response and Stroke Outcomes in Atrial Fibrillation-Related Cardiac Embolic Stroke.

INTRODUCTION: Patients with atrial fibrillation-related stroke (AF-stroke) are prone to developing rapid ventricular response (RVR). We investigated whether RVR is associated with initial stroke severity, early neurological deterioration (END) and poor outcome at 3 months. METHODS: We reviewed patients who had AF-stroke between January 2017 and March 2022. RVR was defined as having heart rate >100 beats per minute on initial electrocardiogram. Neurological deficit was evaluated with National Institutes of Health Stroke Scale (NIHSS) score at admission. END was defined as increase of ≥2 in total NIHSS score or ≥1 in motor NIHSS score within first 72 h. Functional outcome was score on modified Rankin Scale at 3 months. Mediation analysis was performed to examine potential causal chain in which initial stroke severity may mediate relationship between RVR and functional outcome. RESULTS: We studied 568 AF-stroke patients, among whom 86 (15.1%) had RVR. Patients with RVR had higher initial NIHSS score (p < 0.001) and poor outcome at 3 months (p = 0.004) than those without RVR. The presence of RVR [adjusted odds ratio (aOR) = 2.13; p = 0.013] was associated with initial stroke severity, but not with END and functional outcome. Otherwise, initial stroke severity [aOR = 1.27; p = <0.001] was significantly associated with functional outcome. Initial stroke severity as a mediator explained 58% of relationship between RVR and poor outcome at 3 months. CONCLUSION: In patients with AF-stroke, RVR was independently associated with initial stroke severity but not with END and functional outcome. Initial stroke severity mediated considerable proportion of association between RVR and functional outcome.

Impact of Collateral Circulation on Futile Endovascular Thrombectomy in Acute Anterior Circulation Ischemic Stroke.

OBJECTIVE: Collateral circulation is associated with the differential treatment effect of endovascular thrombectomy (EVT) in acute ischemic stroke. We aimed to verify the ability of the collateral map to predict futile EVT in patients with acute anterior circulation ischemic stroke. METHODS: This secondary analysis of a prospective observational study included data from participants underwent EVT for acute ischemic stroke due to occlusion of the internal carotid artery and/or the middle cerebral artery within 8 hours of symptom onset. Multiple logistic regression analyses were conducted to identify independent predictors of futile recanalization (modified Rankin scale score at 90 days of 4-6 despite of successful reperfusion). RESULTS: In a total of 214 participants, older age (odds ratio [OR], 2.40; 95% confidence interval [CI], 1.56 to 3.67; p<0.001), higher baseline National Institutes of Health Stroke Scale (NIHSS) scores (OR, 1.12; 95% CI, 1.04 to 1.21; p=0.004), very poor collateral perfusion grade (OR, 35.09; 95% CI, 3.50 to 351.33; p=0.002), longer door-to-puncture time (OR, 1.08; 95% CI, 1.02 to 1.14; p=0.009), and failed reperfusion (OR, 3.73; 95% CI, 1.30 to 10.76; p=0.015) were associated with unfavorable functional outcomes. In 184 participants who achieved successful reperfusion, older age (OR, 2.30; 95% CI, 1.44 to 3.67; p<0.001), higher baseline NIHSS scores (OR, 1.12; 95% CI, 1.03 to 1.22; p=0.006), very poor collateral perfusion grade (OR, 4.96; 95% CI, 1.42 to 17.37; p=0.012), and longer door-to-reperfusion time (OR, 1.09; 95% CI, 1.03 to 1.15; p=0.003) were associated with unfavorable functional outcomes. CONCLUSION: The assessment of collateral perfusion status using the collateral map can predict futile EVT, which may help select ineligible patients for EVT, thereby potentially reducing the rate of futile EVT.

The collateral map: prediction of lesion growth and penumbra after acute anterior circulation ischemic stroke.

OBJECTIVES: This study evaluated the collateral map's ability to predict lesion growth and penumbra after acute anterior circulation ischemic strokes. METHODS: This was a retrospective analysis of selected data from a prospectively collected database. The lesion growth ratio was the ratio of the follow-up lesion volume to the baseline lesion volume on diffusion-weighted imaging (DWI). The time-to-maximum (Tmax)/DWI ratio was the ratio of the baseline Tmax > 6 s volume to the baseline lesion volume. The collateral ratio was the ratio of the hypoperfused lesion volume of the phase_FU (phase with the hypoperfused lesions most approximate to the follow-up DWI lesion) to the hypoperfused lesion volume of the phase_baseline of the collateral map. Multiple logistic regression analyses were conducted to identify independent predictors of lesion growth. The concordance correlation coefficients of Tmax/DWI ratio and collateral ratio for lesion growth ratio were analyzed. RESULTS: Fifty-two patients, including twenty-six males (mean age, 74 years), were included. Intermediate (OR, 1234.5; p < 0.001) and poor collateral perfusion grades (OR, 664.7; p = 0.006) were independently associated with lesion growth. Phase_FUs were immediately preceded phases of the phase_baselines in intermediate or poor collateral perfusion grades. The concordance correlation coefficients of the Tmax/DWI ratio and collateral ratio for the lesion growth ratio were 0.28 (95% CI, 0.17-0.38) and 0.88 (95% CI, 0.82-0.92), respectively. CONCLUSION: Precise prediction of lesion growth and penumbra can be possible using collateral maps, allowing for personalized application of recanalization treatments. Further studies are needed to generalize the findings of this study. CLINICAL RELEVANCE STATEMENT: Precise prediction of lesion growth and penumbra can be possible using collateral maps, allowing for personalized application of recanalization treatments. KEY POINTS: • Cell viability in cerebral ischemia due to proximal arterial steno-occlusion mainly depends on the collateral circulation. • The collateral map shows salvageable brain extent, which can survive by recanalization treatments after acute anterior circulation ischemic stroke. • Precise estimation of salvageable brain makes it possible to make patient-specific treatment decision.

Differential impacts of admission LDL-cholesterol on early vascular outcomes by ischemic stroke subtypes.

BACKGROUND: Because ischemic stroke is heterogeneous, the associations between low-density lipoprotein (LDL)-cholesterol levels and early vascular outcomes might be different according to the stroke subtype in acute ischemic stroke patients. METHODS: This study was an analysis of a prospective, multicenter, stroke registry. Acute ischemic stroke patients previously not treated with statins were included. Admission LDL-cholesterol levels were divided into 7 groups at 20 mg/dl intervals for comparison. The primary early vascular outcome was a composite of stroke, myocardial infarction (MI) and all-cause mortality within 3 months. RESULTS: A total of 38,531 patients (age, 68.5 ± 12.8 yrs; male, 59.6%) were analyzed for this study. The 3-month cumulative incidences of the composite of stroke, MI, and all-cause mortality significantly differed among the LDL-cholesterol level groups, with the highest event rate (11.11%) in the lowest LDL-cholesterol group (<70 mg/dl). After adjustment, the U-shaped associations of LDL-cholesterol levels with primary outcome and all-cause mortality were observed. For the stroke subtypes, there were substantial interactions between the LDL-cholesterol groups and stroke subtype and all-cause mortality (Pinteraction=0.07). Different patterns, with higher risks of all-cause mortality in the lower LDL-cholesterol in the large artery atherosclerosis subtype (adjusted hazard ratio [aHR] 1.29, 95% confidence interval [CI] 0.98-1.69), but in the higher LDL-cholesterol in the cardioembolism subtype (aHR 1.71 95% CI [1.28-2.29]), were observed among stroke subtypes. CONCLUSION: We found that there were differential associations of admission LDL-cholesterol levels with all-cause mortality within 3 months among stroke subtypes. These results suggest that admission LDL-cholesterol and early vascular outcomes had complex relationships in patients with ischemic stroke according to the stroke subtypes.

Association of high-estimated glomerular filtration rate with the severity of ischemic stroke during non-vitamin K antagonist oral anticoagulants therapy: a nationwide cohort study.

Aim: While the relationship between impaired kidney function and non-vitamin K antagonist oral anticoagulants (NOACs) is well established, there is limited research exploring the association between an elevated estimated glomerular filtration rate (eGFR) and the efficacy of NOACs, especially concerning the outcomes of acute ischemic stroke (AIS). This study aimed to examine the association between higher-than-normal eGFR and the severity of AIS during the use of NOACs using a nationwide multicenter stroke registry in Korea. Material and methods: This study utilized data from the Korean Stroke Registry (KSR) database, examining information from 2,379 patients with AIS, who had atrial fibrillation (AF) and a history of utilizing NOACs prior to hospitalization due to incident stroke occurring between 2016 and 2021. Patients with a history involving two or more types of anticoagulants or one or more forms of antiplatelet agents were excluded. Baseline characteristics, medical history, medication usage, CHADS2-VASc score, and the anticoagulation and risk factors in atrial fibrillation (ATRIA) score were evaluated. Renal function was assessed using eGFR levels and calculated with the Cockcroft-Gault equation. The severity of stroke was measured by the National Institutes of Health Stroke Scale as an outcome. For sensitivity analysis, further evaluation was performed using eGFR levels according to the modification of diet in renal disease (MDRD) study equation. Results: The mean age of subjects was 76.1 ± 8.9 years. The moderate-to-severe stroke severity group exhibited an elevation in creatinine levels. The eGFR of 60 to 89 mL/min/1.73 m2 group was associated with a decreased risk of moderate-to-severe stroke severity [hazard ratio (HR)] (0.77, 95% confidence interval (CI) [0.61, 0.98], p = 0.031) compared to the eGFR≥90 mL/min/1.73 m2 group. An increment of 10 units in eGFR was marginally associated with an increased risk of moderate-to-severe stroke severity (HR: 1.03, 95% CI [1.00, 1.07], p = 0.054). Conclusion: The study revealed that individuals with eGFR ≥ 90 mL/min/1.73 m2 had an association linked to an increased risk of moderate-to-severe stroke severity. Our study suggests that patients taking NOACs with higher-than-normal eGFR levels may have an increased severity of AIS.

Improvement in Delivery of Ischemic Stroke Treatments but Stagnation of Clinical Outcomes in Young Adults in South Korea.

BACKGROUND: There is limited information on the delivery of acute stroke therapies and secondary preventive measures and clinical outcomes over time in young adults with acute ischemic stroke. This study investigated whether advances in these treatments improved outcomes in this population. METHODS: Using a prospective multicenter stroke registry in Korea, young adults (aged 18-50 years) with acute ischemic stroke hospitalized between 2008 and 2019 were identified. The observation period was divided into 4 epochs: 2008 to 2010, 2011 to 2013, 2014 to 2016, and 2017 to 2019. Secular trends for patient characteristics, treatments, and outcomes were analyzed. RESULTS: A total of 7050 eligible patients (mean age, 43.1; men, 71.9%) were registered. The mean age decreased from 43.6 to 42.9 years (Ptrend=0.01). Current smoking decreased, whereas obesity increased. Other risk factors remained unchanged. Intravenous thrombolysis and mechanical thrombectomy rates increased over time from 2008 to 2010 to 2017 to 2019 (9.5%-13.8% and 3.2%-9.2%, respectively; Ptrend<0.01). Door-to-needle time improved (Ptrend <.001), but onset-to-door and door-to-puncture times remained constant. Secondary prevention, including dual antiplatelets for noncardioembolic minor stroke (26.7%-47.0%), direct oral anticoagulants for atrial fibrillation (0.0%-56.2%), and statins for large artery atherosclerosis (76.1%-95.3%) increased (Ptrend<0.01). Outcome data were available from 2011. One-year mortality (2.5% in 2011-2013 and 2.3% in 2017-2019) and 3-month modified Rankin Scale scores 0 to 1 (68.3%-69.1%) and 0 to 2 (87.6%-86.2%) remained unchanged. The 1-year stroke recurrence rate increased (4.1%-5.5%; Ptrend=0.04), although the difference was not significant after adjusting for sex and age. CONCLUSIONS: Improvements in the delivery of acute stroke treatments did not necessarily lead to better outcomes in young adults with acute ischemic stroke over the past decade, indicating a need for further progress.

Nonhypertensive White Matter Hyperintensities in Stroke: Risk Factors, Neuroimaging Characteristics, and Prognosis.

BACKGROUND: This study explored the risk factors, neuroimaging features, and prognostic implications of nonhypertensive white matter hyperintensity (WMH) in patients with acute ischemic stroke and transient ischemic attack. METHODS AND RESULTS: We included 2283 patients with hypertension and 1003 without from a pool of 10 602. Associations of moderate-to-severe WMH with known risk factors, functional outcome, and a composite of recurrent stroke, myocardial infarction, and all-cause mortality were evaluated. A subset of 351 patients without hypertension and age- and sex-matched pairs with hypertension and moderate-to-severe WMH was created for a detailed topographic examination of WMH, lacunes, and microbleeds. Approximately 35% of patients without hypertension and 65% of patients with hypertensive stroke exhibited moderate-to-severe WMH. WMH was associated with age, female sex, and previous stroke, irrespective of hypertension. In patients without hypertension, WMH was associated with initial systolic blood pressure and was more common in the anterior temporal region. In patients with hypertension, WMH was associated with small vessel occlusion as a stroke mechanism and was more frequent in the periventricular region near the posterior horn of the lateral ventricle. The higher prevalence of occipital microbleeds in patients without hypertension and deep subcortical lacunes in patients with hypertension were also observed. Associations of moderate-to-severe WMH with 3-month functional outcome and 1-year cumulative incidence of the composite outcome were significant (both P<0.01), although the latter lost significance after adjustments. The associations between WMH and outcomes were consistent across hypertensive status. CONCLUSIONS: One-third of patients without hypertension with stroke have moderate-to-severe WMH. The pathogenesis of WMH may differ between patients without and with hypertension, but its impact on outcome appears similar.