3D Superclusters with Hybrid Bioinks for Early Detection in Breast Cancer.

The surface-enhanced Raman scattering (SERS) technique has garnered significant interest due to its ultrahigh sensitivity, making it suitable for addressing the growing demand for disease diagnosis. In addition to its sensitivity and uniformity, an ideal SERS platform should possess characteristics such as simplicity in manufacturing and low analyte consumption, enabling practical applications in complex diagnoses including cancer. Furthermore, the integration of machine learning algorithms with SERS can enhance the practical usability of sensing devices by effectively classifying the subtle vibrational fingerprints produced by molecules such as those found in human blood. In this study, we demonstrate an approach for early detection of breast cancer using a bottom-up strategy to construct a flexible and simple three-dimensional (3D) plasmonic cluster SERS platform integrated with a deep learning algorithm. With these advantages of the 3D plasmonic cluster, we demonstrate that the 3D plasmonic cluster (3D-PC) exhibits a significantly enhanced Raman intensity through detection limit down to 10-6 M (femtomole-(10-17 mol)) for p-nitrophenol (PNP) molecules. Afterward, the plasma of cancer subjects and healthy subjects was used to fabricate the bioink to build 3D-PC structures. The collected SERS successfully classified into two clusters of cancer subjects and healthy subjects with high accuracy of up to 93%. These results highlight the potential of the 3D plasmonic cluster SERS platform for early breast cancer detection and open promising avenues for future research in this field.

Mapping the Supratentorial Cerebral Arterial Territories Using 1160 Large Artery Infarcts.

Importance: Cerebral vascular territories are of key clinical importance in patients with stroke, but available maps are highly variable and based on prior studies with small sample sizes. Objective: To update and improve the state of knowledge on the supratentorial vascular supply to the brain by using the natural experiment of large artery infarcts and to map out the variable anatomy of the anterior, middle, and posterior cerebral artery (ACA, MCA, and PCA) territories. Design, Setting, and Participants: In this cross-sectional study, digital maps of supratentorial infarcts were generated using diffusion-weighted magnetic resonance imaging (MRI) of 1160 patients with acute (<1-week) stroke recruited (May 2011 to February 2013) consecutively from 11 Korean stroke centers. All had supratentorial infarction associated with significant stenosis or occlusion of 1 of 3 large supratentorial cerebral arteries but with patent intracranial or extracranial carotid arteries. Data were analyzed between February 2016 and August 2017. Main Outcomes and Measures: The 3 vascular territories were mapped individually by affected vessel, generating 3 data sets for which infarct frequency is defined for each voxel in the data set. By mapping these 3 vascular territories collectively, we generated data sets showing the Certainty Index (CI) to reflect the likelihood of a voxel being a member of a specific vascular territory, calculated as either ACA, MCA, or PCA infarct frequency divided by total infarct frequency in that voxel. Results: Of the 1160 patients (mean [SD] age, 67.0 [13.3] years old), 623 were men (53.7%). When the cutoff CI was set as 90%, the volume of the MCA territory (approximately 54% of the supratentorial parenchymal brain volume) was about 4-fold bigger than the volumes of the ACA and PCA territories (each approximately 13%). Quantitative studies showed that the medial frontal gyrus, superior frontal gyrus, and anterior cingulate were involved mostly in ACA infarcts, whereas the middle frontal gyrus and caudate were involved mostly by MCA infarcts. The PCA infarct territory was smaller and narrower than traditionally shown. Border-zone maps could be defined by using either relative infarct frequencies or CI differences. Conclusions and Relevance: We have generated statistically rigorous maps to delineate territorial border zones and lines. The new topographic brain atlas can be used in clinical care and in research to objectively define the supratentorial arterial territories and their borders.

Statistical analysis on finger replacement schemes for RAKE receivers in the soft handover region with multiple BSs over i.n.d. fading channels.

A new finger replacement technique which is applicable for RAKE receivers in the soft handover region has been proposed and studied under the ideal assumption that the fading is both independent and identically distributed from path to path. To supplement our previous work, we present a general comprehensive framework for the performance assessment of the proposed finger replacement schemes operating over independent but non-identically distributed (i.n.d.) faded paths. To accomplish this object, we derive new closed-form expressions for the target key statistics which are composed of i.n.d. exponential random variables. With these new expressions, the performance analysis of various wireless communication systems over more practical channel environments can be possible.

Preceding Intravenous Thrombolysis in Patients Receiving Endovascular Therapy.

BACKGROUND: The beneficial effects of endovascular therapy (EVT) in acute ischemic stroke have been demonstrated in recent clinical trials using new-generation thrombectomy devices. However, the comparative effectiveness and safety of preceding intravenous thrombolysis (IVT) in this population has rarely been evaluated. METHODS: From a prospective multicenter stroke registry database in Korea, we identified patients with acute ischemic stroke who were treated with EVT within 8 h of onset and admitted to 14 participating centers during 2008-2013. The primary outcome was a modified Rankin Scale (mRS) score at 3 months. Major secondary outcomes were successful recanalization defined as a modified Treatment in Cerebral Ischemia score of 2b-3, functional independence (mRS score 0-2), mortality at 3 months, and symptomatic hemorrhagic transformation (SHT) during hospitalization. Multivariable logistic regression analyses using generalized linear mixed models were performed to estimate the adjusted odds ratios (ORs) of preceding IVT. RESULTS: Of the 639 patients (male, 61%; age 69 ± 12; National Institutes of Health Stroke Scale score of 15 [11-19]) who met the eligibility criteria, 458 received preceding IVT. These patients showed lower mRS scores (adjusted common OR, 1.38 [95% CI 0.98-1.96]). Preceding IVT was associated with successful recanalization (1.96 [1.23-3.11]) and reduced 3-month mortality (0.58 [0.35-0.97]) but not with SHT (0.96 [0.48-1.93]). CONCLUSION: In patients treated with EVT within 8 of acute ischemic stroke onset, preceding IVT may enhance survival and successful recanalization without additional risk of SHT, and mitigate disability at 3 months.

Stroke outcomes are worse with larger leukoaraiosis volumes.

Leukoaraiosis or white matter hyperintensities are frequently observed on magnetic resonance imaging of stroke patients. We investigated how white matter hyperintensity volumes affect stroke outcomes, generally and by subtype. In total, 5035 acute ischaemic stroke patients were enrolled. Strokes were classified as large artery atherosclerosis, small vessel occlusion, or cardioembolism. White matter hyperintensity volumes were stratified into quintiles. Mean age (± standard deviation) was 66.3 ± 12.8, 59.6% male. Median (interquartile range) modified Rankin Scale score was 2 (1-3) at discharge and 1 (0-3) at 3 months; 16.5% experienced early neurological deterioration, and 3.3% recurrent stroke. The Cochran-Mantel-Haenszel test with adjustment for age, stroke severity, sex, and thrombolysis status showed that the distributions of 3-month modified Rankin Scale scores differed across white matter hyperintensity quintiles (P < 0.001). Multiple ordinal logistic regression analysis showed that higher white matter hyperintensity quintiles were independently associated with worse 3-month modified Rankin Scale scores; adjusted odds ratios (95% confidence interval) for the second to fifth quintiles versus the first quintile were 1.29 (1.10-1.52), 1.40 (1.18-1.66), 1.69 (1.42-2.02) and 2.03 (1.69-2.43), respectively. For large artery atherosclerosis (39.0%), outcomes varied by white matter hyperintensity volume (P = 0.01, Cochran-Mantel-Haenszel test), and the upper three white matter hyperintensity quintiles (versus the first quintile) had worse 3-month modified Rankin Scale scores; adjusted odds ratios were 1.45 (1.10-1.90), 1.86 (1.41-2.47), and 1.89 (1.41-2.54), respectively. Patients with large artery atherosclerosis were vulnerable to early neurological deterioration (19.4%), and the top two white matter hyperintensity quintiles were more vulnerable still: 23.5% and 22.3%. Moreover, higher white matter hyperintensities were associated with poor modified Rankin Scale improvement: adjusted odds ratios for the upper two quintiles versus the first quintile were 0.66 (0.47-0.94) and 0.62 (0.43-0.89), respectively. For small vessel occlusion (17.8%), outcomes tended to vary by white matter hyperintensitiy volume (P = 0.10, Cochran-Mantel-Haenszel test), and the highest quintile was associated with worse 3-month modified Rankin Scale scores: adjusted odds ratio for the fifth quintile versus first quintile, 1.98 (1.23-3.18). In this subtype, worse white matter hyperintensities were associated with worse National Institute of Health Stroke Scale scores at presentation. For cardioembolism (20.6%), outcomes did not vary significantly by white matter hyperintensity volume (P = 0.19, Cochran-Mantel-Haenszel test); however, the adjusted odds ratio for the highest versus lowest quintiles was 1.62 (1.09-2.40). Regardless of stroke subtype, white matter hyperintensities were not associated with stroke recurrence within 3 months of follow-up. In conclusion, white matter hyperintensity volume independently correlates with stroke outcomes in acute ischaemic stroke. There are some suggestions that stroke outcomes may be affected by leukoaraiosis differentially depending on stroke subtypes, to be confirmed in future investigations.

Air Pollution Is Associated With Ischemic Stroke via Cardiogenic Embolism.

BACKGROUND AND PURPOSE: The aim of the study was to assessed the impact of short-term exposure to air pollution on ischemic stroke subtype, while focusing on stroke caused via cardioembolism. METHODS: From a nationwide, multicenter, prospective, stroke registry database, 13 535 patients with acute ischemic stroke hospitalized to 12 participating centers were enrolled in this study. Data on the hourly concentrations of particulate matter <10 µm, nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and carbon monoxide (CO) were collected from 181 nationwide air pollution surveillance stations. The average values of these air pollutants over the 7 days before stroke onset from nearest air quality monitoring station in each patient were used to determine association with stroke subtype. The primary outcome was stroke subtype, including large artery atherosclerosis, small-vessel occlusion, cardioembolism, and stroke of other or undetermined cause. RESULTS: Particulate matter <10 µm and SO2 concentrations were independently associated with an increased risk of cardioembolic stroke, as compared with large artery atherosclerosis and noncardioembolic stroke. In stratified analyses, the proportion of cases of cardioembolic stroke was positively correlated with the particulate matter <10 µm, NO2, and SO2 quintiles. Moreover, seasonal and geographic factors were related to an increased proportion of cardioembolic stroke, which may be attributed to the high levels of air pollution. CONCLUSIONS: Our findings suggest that the short-term exposure to air pollutants is associated with cardioembolic stroke, and greater care should be taken for those susceptible to cerebral embolism during peak pollution periods. Public and environmental health policies to reduce air pollution could help slow down global increasing trends of cardioembolic stroke.

Clinical Outcomes of Posterior Versus Anterior Circulation Infarction With Low National Institutes of Health Stroke Scale Scores.

BACKGROUND AND PURPOSE: We compared baseline characteristics and outcomes at 3 months between patients with minor anterior circulation infarction (ACI) versus minor posterior circulation infarction (PCI), including the influence of large vessel disease on outcomes. METHODS: This study is an analysis of a prospective multicenter registry database in South Korea. Eligibility criteria were patients with ischemic stroke admitted within 7 days of stroke onset, lesions in either anterior or posterior circulation, and National Institutes of Health Stroke Scale score of ≤4 at baseline. Patients were divided into 4 groups for further analysis: minor ACI with and without internal carotid artery/middle cerebral artery large vessel disease and minor PCI with and without vertebrobasilar large vessel disease. RESULTS: A total of 7178 patients (65.2±12.6 years) were analyzed in this study, and 2233 patients (31.1%) had disability (modified Rankin Scale score 2-6) at 3 months. Disability was 32.3% in minor PCI and 30.3% in minor ACI (P=0.07), and death was 1.3% and 1.5%, respectively (P=0.82). In a multivariable logistic regression analysis, minor PCI was significantly associated with disability at 3 months when compared with minor ACI (odds ratio, 1.23; 95% confidence interval, 1.09-1.37; P<0.001). In pairwise comparisons, minor PCI with vertebrobasilar large vessel disease was independently associated with disability at 3 months, compared with the other 3 groups. CONCLUSIONS: Our study showed that minor PCI exhibited more frequent disability at 3 months than minor ACI. Especially, the presence of vertebrobasilar large vessel disease in minor PCI had a substantially higher risk of disability. Our results suggest that minor PCI with vertebrobasilar large vessel disease could require more meticulous care and are important targets for further study.

Endovascular Treatment in Patients with Persistent Internal Carotid Artery Occlusion after Intravenous Tissue Plasminogen Activator: A Clinical Effectiveness Study.

BACKGROUND: There has been no large-scale trial comparing endovascular treatment (add-on EVT) after intravenous tissue plasminogen activator (IV tPA) and IV tPA alone in acute ischemic stroke (AIS) caused by internal carotid artery occlusion (ICAO). We aimed at investigating the effectiveness and safety of add-on EVT after IV tPA in AIS patients with ICAO. METHODS: Between March 2010 and March 2013, 3,689 consecutive ischemic stroke patients who were hospitalized within 4.5 h of onset were identified using a prospective stroke registry at 11 centers in Korea. Among them, patients with persistent ICAO after receiving IV tPA and whose 3-month modified Rankin Scale (mRS) was available were finally enrolled. A propensity score analysis with inverse-probability of treatment weighting was used to eliminate baseline imbalances between those receiving add-on EVT and IV tPA alone. RESULTS: Among 264 patients enrolled in this study (mean age 71.4; male 56.4%; median National Institute of Health Stroke Scale score 15), 117 (44.3%) received add-on EVT. The add-on EVT group had a higher frequency of favorable outcome on the mRS ≤2 (35.0 vs. 18.4%; adjusted OR (aOR) 2.79; 95% CI 1.66-4.67) and lower mortality (17.9 vs. 35.4%; aOR 0.24; 95% CI 0.13-0.42) at 3 months, when compared to the IV tPA-alone group. Add-on EVT did not significantly increase the risk of symptomatic hemorrhage (5.1 vs. 4.1%; aOR 1.01; 95% CI 0.37-2.70). The rate of successful recanalization (thrombolysis in cerebral infarction grade ≥2b) in the add-on EVT group was 69.2%. CONCLUSIONS: Compared to an IV tPA alone, add-on EVT can improve clinical outcomes in patients with symptomatic ICAO within 4.5 h of onset without a significant increase of symptomatic hemorrhage.

Family History and Risk of Recurrent Stroke.

BACKGROUND AND PURPOSE: The association between family history of stroke and stroke recurrence remains unclear. METHODS: Using a web-based multicenter stroke registry database, information on history of stroke in first-degree relatives was collected prospectively for acute ischemic stroke patients who were hospitalized within 7 days of onset. The collected information was categorized as follows: type of the affected relative(s) with stroke (paternal, maternal, sibling, or 2 or more) and age of the relative's stroke onset (<50, 50-59, 60-69, and ≥70 years). Stroke recurrence was captured prospectively using a predetermined protocol. Subgroup analyses were performed according to the patient's age at the index stroke. RESULTS: Among 7642 patients, 937 (12.3%) had a history of stroke in their first-degree relatives and 475 (6.2%: 201 within and 274 after 3 weeks from index stroke) experienced stroke recurrence (median follow-up, 365 days). In multivariable Cox proportional hazard models, overall family history was not associated with stroke recurrence (hazard ratio, 1.08; 95% confidence interval, 0.81-1.43). However, the details of their family histories, including relative's age at stroke onset (<50 years: hazard ratio, 2.14; 95% confidence interval, 1.004-4.54) and stroke history in a sibling (hazard ratio, 1.67; 95% confidence interval, 1.09-2.58), were independently associated with stroke recurrence after adjusting for potential confounders. The associations appeared to be stronger in young adults with stroke (age, <55 years) than in older stroke patients. CONCLUSIONS: This study suggests that elevated risks of recurrent stroke are associated with having relatives with early-onset stroke and siblings with stroke histories, implying that additional precautions may be needed in such populations.

Should we exclude acute stroke patients with previous intracerebral hemorrhage from receiving intravenous thrombolysis?

BACKGROUND: Current guidelines have contraindicated history of intracerebral hemorrhage for intravenous recombinant tissue plasminogen activator. AIM: This study aimed to investigate the safety and effectiveness of intravenous recombinant tissue plasminogen activator for patients who had previous intracerebral hemorrhage on history or initial brain magnetic resonance imaging. METHODS: Using a prospective multicenter stroke registry database, we identified acute ischemic stroke patients treated with intravenous recombinant tissue plasminogen activator within 4.5 h of onset. Previous intracerebral hemorrhage was defined as having a clinical history or evidence of old intracerebral hemorrhage on initial brain magnetic resonance imaging. Associations of previous intracerebral hemorrhage with symptomatic hemorrhagic transformation during hospitalization and functional outcome and mortality at discharge and three months were analyzed. RESULTS: Among 1495 patients who were treated with intravenous recombinant tissue plasminogen activator, 73 (4.9%) had previous intracerebral hemorrhage; 9 on history only, 61 on magnetic resonance imaging only and 3 on both. Of those 1495 patients, 71 (4.7%) experienced symptomatic hemorrhagic transformation; 6.8% in patients with previous intracerebral hemorrhage and 4.6% in those without previous intracerebral hemorrhage. Multivariable logistic regression analysis showed that previous intracerebral hemorrhage did not significantly increase the risk of symptomatic hemorrhagic transformation (odds ratio 1.08, 95% confidence interval 0.39-2.96) mortality, and most of functional outcome measures CONCLUSIONS: Previous intracerebral hemorrhage may neither increase the risk of symptomatic hemorrhagic transformation nor alter major clinical outcomes in acute ischemic stroke patients receiving intravenous recombinant tissue plasminogen activator. This study suggests reconsideration of prior history of intracerebral hemorrhage as an exclusion criterion for intravenous recombinant tissue plasminogen activator administration in acute ischemic stroke.

Impact of Guidelines on Clinical Practice: Intravenous Heparin Use for Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Since its introduction, controversy has existed about the administration of intravenous heparin for the treatment of acute ischemic stroke. We studied trends in the intravenous heparin use during a 6-year time period and the potential influence of clinical guidelines in national language on intravenous heparin administration in Korea. METHODS: On the basis of a prospective nationwide multicenter stroke registry, we collected data on patients with acute ischemic stroke who arrived within 7 days of symptom onset during the time period 2008 to 2013. We studied patient demographics, prestroke medical history, stroke characteristics, and stroke treatment. Data from a total of 23 425 patients from 12 university hospitals or regional stroke centers were analyzed. RESULTS: The administration of intravenous heparin steadily decreased throughout the study period: 9.7% in 2008, 10.9% in 2009, 9.4% in 2010, 6.0% in 2011, 4.7% in 2012, and 4.3% in 2013 (P for trend <0.001). The reduced intravenous heparin use was associated with moderate stroke severity, atrial fibrillation, and stroke of cardioembolic, other-, and undetermined etiology. In a multivariable logistic model, increase of 1 calendar year (odds ratio, 0.89; 95% confidence interval, 0.84-0.95; P<0.001) and release of clinical practice guidelines in Korean (odd ratio, 0.74; 95% confidence interval, 0.59-0.91; P<0.01) were independent factors associated with reduction in the frequency of intravenous heparin use. CONCLUSIONS: Use of intravenous heparin for acute ischemic stroke treatment has decreased in Korea, and this change may be attributable to the spread and successful implementation of regional clinical practice guidelines.

Comparative Effectiveness of Prestroke Aspirin on Stroke Severity and Outcome.

OBJECTIVE: The effect of prestroke aspirin use on initial severity, hemorrhagic transformation, and functional outcome of ischemic stroke is uncertain. METHODS: Using a multicenter stroke registry database, patients with acute ischemic stroke of three subtypes (large artery atherosclerosis [LAA], small vessel occlusion [SVO], or cardioembolism [CE]) were identified. NIH stroke scale (NIHSS) and hemorrhagic transformation at presentation and discharge modified Rankin Scale (mRS) were compared between prestroke aspirin users and nonusers. RESULTS: Among the 10,433 patients, 1,914 (18.3%) reported prestroke aspirin use. On crude analysis, initial NIHSS scores of aspirin users were higher than nonusers (mean difference: 0.35; 95% confidence interval [CI]: 0.04-0.66). However, a multivariable analysis with an application of inverse probability of treatment weighting based on a propensity score of prestroke aspirin, having an interaction effect of prestroke aspirin use and stroke subtype in the model, showed less stroke severity for aspirin users in LAA, but not in SVO and CE than for nonusers; mean difference in NIHSS scores in LAA was -0.97 (95% CI: -1.45 to -0.49). With respect to hemorrhagic transformation and mRS, no significant interaction effects were found. Prestroke aspirin use increased the risk of hemorrhagic transformation (adjusted odd ratio: 1.34; 95% CI: 1.05-1.73), but decreased the odds of the higher discharge mRS (0.86; 0.76-0.96). INTERPRETATION: Prestroke aspirin use may reduce initial stroke severity in atherothrombotic stroke and can improve functional outcome at discharge despite an increase of hemorrhagic transformation irrespective of stroke subtype.

Direct admission to stroke centers reduces treatment delay and improves clinical outcome after intravenous thrombolysis.

We aimed to examine whether direct access to hospitals offering intravenous thrombolysis is associated with functional outcomes in patients with acute ischemic stroke treated with intravenous thrombolysis. We enrolled patients who received intravenous thrombolysis within 4.5hours of symptom onset using a prospective multicenter registry database. Patients referred directly from the field to organized stroke centers were compared with those who were transferred from non-thrombolysis-capable hospitals in terms of clinical outcomes at 90days after intravenous recombinant tissue plasminogen activator treatment. We also investigated onset-to-door time and onset-to-needle time according to admission mode. A total of 820 patients (mean age of 67.3years and median National Institutes of Health Stroke Scale score of 9) were enrolled. Seventeen percent of patients with AIS who received intravenous thrombolytic therapy at 12 hospitals (n=142) were transferred from other hospitals. The direct admission group had a shorter median onset-to-admission time (63 versus 121minutes, P<0.001) and onset-to-needle time (110 versus 161minutes, P<0.001) as compared with the indirect admission group. Direct admission was associated with a good outcome with an odds ratio of 1.57 (95% confidence interval: 1.02-2.39, P=0.036) after adjustment for baseline variables. Direct admission to a hospital with intravenous thrombolysis facilities available at all times was associated with shorter onset-to-needle time and better outcome in patients with AIS undergoing thrombolytic therapy. Our findings support the implementation of regional stroke care programs transporting patients directly to stroke centers to promote faster treatment and to achieve better outcomes.

Recurrent Stroke, Myocardial Infarction, and Major Vascular Events during the First Year after Acute Ischemic Stroke: The Multicenter Prospective Observational Study about Recurrence and Its Determinants after Acute Ischemic Stroke I.

BACKGROUND: Patients with acute ischemic stroke (AIS) are at high risk of subsequent vascular events. The aim of this study was to estimate rates of recurrent stroke, myocardial infarction (MI), and major vascular events during the first year after AIS in Korea. METHODS: Through a multicenter stroke registry in Korea, 12,227 consecutive cases of AIS were identified between November 2010 and May 2013 and were followed up for recurrent stroke, MI, and major vascular events up to 1 year after stroke. RESULTS: Cumulative 30-day, 90-day and 1-year rates were 2.7%, 3.9%, and 5.7% for recurrent stroke; .1%, .3%, and .5% for MI; and 8.1%, 10.6%, and 13.7% for major vascular events, indicating that the early period is at high risk of recurrent stroke and major vascular events. The risk of recurrent stroke was substantially higher than the risk of MI: 13.0 times at 90 days and 11.4 times at 1 year. Compared to those with small-vessel occlusion (SVO), those with ischemic stroke subtypes other than SVO had a higher risk of recurrent stroke as well as major vascular events. Other common independent predictors for recurrent stroke and major vascular events were diabetes and prior stroke history. CONCLUSIONS: During the first year after AIS, one in 18 had recurrent stroke and one in 7 major vascular events. More than two thirds of recurrent stroke and three quarters of major vascular events developed within 90 days in a Korean cohort of stroke patients. Better prevention strategies are required for high-risk patients during this high-risk period.

Adherence to Guidelines for Antithrombotic Therapy in Patients with Atrial Fibrillation According to CHADS2 Score before and after Stroke: A Multicenter Observational Study from Korea.

BACKGROUND AND PURPOSE: A substantial proportion of patients with atrial fibrillation (AF) are not treated optimally; however, the inappropriateness of drug therapy has never been evaluated before or after a stroke event. We investigated the adherence to guidelines for therapy in AF patients hospitalized with acute ischemic stroke (AIS) before stroke onset and at discharge, with the aim of identifying the factors associated with inappropriate therapy. METHODS: AIS patients with AF hospitalized within 7 days of onset were identified from a prospective nine-center stroke registry database. Two cohorts were defined: patients diagnosed with AF prior to the stroke event (admission cohort) and patients diagnosed with AF at discharge from hospital (discharge cohort). Any of the following conditions were regarded as nonadherence to guidelines in this study: use of anticoagulant or nonuse of antithrombotics with CHADS2 score=0, nonuse of antithrombotics with CHADS2 score=1, or nonuse of anticoagulant with CHADS2 score ≥2. RESULTS: Overall, 406 patients were enrolled in the admission cohort and 518 in the discharge cohort. The rates of nonadherence before a stroke event and at discharge were 77.8% and 33.3%, respectively. These rates varied widely for both cohorts, with interhospital differences being statistically significant. Multivariable analysis revealed that old age, stroke history, and congestive heart failure were associated with nonadherence before stroke. At discharge, males, coronary heart disease, inappropriate antithrombotic use before stroke, and functional disability at discharge were associated with nonadherence. CONCLUSIONS: This study shows that antithrombotic use in AIS patients with AF might be not optimal before and after stroke in Korea.

Different Antiplatelet Strategies in Patients With New Ischemic Stroke While Taking Aspirin.

BACKGROUND AND PURPOSE: Selecting among different antiplatelet strategies when patients experience a new ischemic stroke while taking aspirin is a common clinical challenge, currently addressed by a paucity of data. METHODS: This study is an analysis of a prospective multicenter stroke registry database from 14 hospitals in South Korea. Patients with acute noncardioembolic stroke, who were taking aspirin for prevention of ischemic events at the time of onset of stroke, were enrolled. Study subjects were divided into 3 groups according to the subsequent antiplatelet therapy strategy pursued; maintaining aspirin monotherapy (MA group), switching aspirin to nonaspirin antiplatelet agents (SA group), and adding another antiplatelet agent to aspirin (AA group). The primary study end point was the composite of stroke (ischemic and hemorrhagic), myocardial infarction, and vascular death up to 1 year after stroke onset. RESULTS: A total of 1172 patients were analyzed for this study. Antiplatelet strategies pursued in study patients were MA group in 212 (18.1%), SA group in 246 (21.0%), and AA group in 714 (60.9%). The Cox proportional hazards regression analysis showed that, compared with the MA group, there was a reduction in the composite vascular event primary end point in the SA group (hazard ratio, 0.50; 95% confidence interval, 0.27-0.92; P=0.03) and in the AA group (hazard ratio, 0.40; 95% confidence interval, 0.24-0.66; P<0.001). CONCLUSIONS: This study showed that, compared with maintaining aspirin, switching to or adding alternative antiplatelet agents may be better in preventing subsequent vascular events in patients who experienced a new ischemic stroke while taking aspirin.

Moderate alcohol intake reduces risk of ischemic stroke in Korea.

OBJECTIVE: We undertook a population-based, case-control study to examine a dose-response relationship between alcohol intake and risk of ischemic stroke in Koreans who had different alcoholic beverage type preferences than Western populations and to examine the effect modifications by sex and ischemic stroke subtypes. METHODS: Cases (n = 1,848) were recruited from patients aged 20 years or older with first-ever ischemic stroke. Stroke-free controls (n = 3,589) were from the fourth and fifth Korean National Health and Nutrition Examination Survey and were matched to the cases by age (±3 years), sex, and education level. All participants completed an interview using a structured questionnaire about alcohol intake. RESULTS: Light to moderate alcohol intake, 3 or 4 drinks (1 drink = 10 g ethanol) per day, was significantly associated with a lower odds of ischemic stroke after adjusting for potential confounders (no drinks: reference; <1 drink: odds ratio 0.38, 95% confidence interval 0.32-0.45; 1-2 drinks: 0.45, 0.36-0.57; and 3-4 drinks: 0.54, 0.39-0.74). The threshold of alcohol effect in women was slightly lower than that in men (up to 1-2 drinks in women vs up to 3-4 drinks in men), but this difference was not statistically significant. There was no statistical interaction between alcohol intake and the subtypes of ischemic stroke (p = 0.50). The most frequently used alcoholic beverage was one native to Korea, soju (78% of the cases), a distilled beverage with 20% ethanol by volume. CONCLUSIONS: Our findings suggest that light to moderate distilled alcohol consumption may reduce the risk of ischemic stroke in Koreans.

Identifying Target Risk Factors Using Population Attributable Risks of Ischemic Stroke by Age and Sex.

BACKGROUND AND PURPOSE: Estimating age- and sex-specific population attributable risks (PARs) of major risk factors for stroke may be a useful strategy to identify risk factors for targeting preventive strategies. METHODS: For this case-control matched study, consecutive patients aged 18-90 years and admitted to nine nationwide hospitals with acute ischemic stroke between December 2008 and June 2010, were enrolled as cases. Controls, individually matched by age and sex, were chosen from the 4th Korean National Health & Nutrition Examination Survey (2008-2010). Based on odds ratios and prevalence, standardized according to the age and sex structure of the Korean population, PARs of major risk factors were estimated according to age (young, ≤ 45; middle-aged, 46-65; and elderly, ≥ 66 years) and sex subgroups. RESULTS: In 4,743 matched case-control sets, smoking (PAR, 45.1%) was the greatest contributing risk factor in young men, followed by hypertension (28.5%). In middle-aged men, the greatest contributing factors were smoking (37.4%), hypertension (22.7%), and diabetes (14.6%), whereas in women the greatest factors were hypertension (22.7%) and stroke history (10.6%). In the elderly, hypertension was the leading factor in men (23.7%) and women (23.4%). Other noticeable factors were stroke history (men, 19.7%; women, 17.3%) and diabetes (men, 12.5%; women, 15.1%). In young women, risk factors with a PAR greater than 10% were not found. CONCLUSIONS: Smoking cessation in young people and hypertension and diabetes control in older people may be effective in reducing the burden of stroke on the population. In the elderly, secondary prevention could also be emphasized.

Intravenous Tissue Plasminogen Activator Improves the Outcome in Very Elderly Korean Patients with Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: In a recent pooled analysis of randomized clinical trials (RCTs), intravenous tissue plasminogen activator (TPA) improves the outcome in patients aged ≥80 years. However, it is uncertain whether the findings are applicable to clinical practice in Asian populations. METHODS: From a multicenter stroke registry database of Korea, we identified patients with acute ischemic stroke who were aged ≥ 80 years. Using multivariable analysis and propensity score (PS)-matched analyses, we assessed the effectiveness and safety of intravenous TPA within 4.5 hours. RESULTS: Among 2,334 patients who met the eligible criteria, 236 were treated with intravenous TPA (mean age, 83±5; median NIHSS, 13 [IQR, 8-17]). At discharge, the TPA group compared to the no-TPA group had a favorable shift on the modified Rankin Scale (mRS) score (multivariable analysis, OR [95% CI], 1.51 [1.17-1.96], P=0.002; PS-matched analysis, 1.54 [1.17-2.04], P=0.002) and was more likely to achieve mRS 0-1 outcome (multivariable analysis, 2.00 [1.32-3.03], P=0.001; PS-matched analysis, 1.59 [1.04-2.42], P=0.032). TPA treatment was associated with an increased risk of symptomatic intracranial hemorrhage (multivariable analysis, 5.45 [2.80-10.59], P<0.001; PS-matched analysis, 4.52 [2.24-9.13], P<0.001), but did not increase the in-hospital mortality (multivariable analysis, 0.86 [0.50-1.48], P=0.58; PS-matched analysis, 0.88 [0.52-1.47], P=0.61). CONCLUSIONS: In the setting of clinical practice, intravenous TPA within 4.5 hours improved the functional outcome despite an increased risk of symptomatic intracranial hemorrhage in very elderly Korean patients. The findings, consistent with those from pooled analysis of RCTs, strongly support the use of TPA for this population.