Contemporary Statistics of Acute Ischemic Stroke and Transient Ischemic Attack in 2021: Insights From the CRCS-K-NIH Registry.

This report presents the latest statistics on the stroke population in South Korea, sourced from the Clinical Research Collaborations for Stroke in Korea-National Institute for Health (CRCS-K-NIH), a comprehensive, nationwide, multicenter stroke registry. The Korean cohort, unlike western populations, shows a male-to-female ratio of 1.5, attributed to lower risk factors in Korean women. The average ages for men and women are 67 and 73 years, respectively. Hypertension is the most common risk factor (67%), consistent with global trends, but there is a higher prevalence of diabetes (35%) and smoking (21%). The prevalence of atrial fibrillation (19%) is lower than in western populations, suggesting effective prevention strategies in the general population. A high incidence of large artery atherosclerosis (38%) is observed, likely due to prevalent intracranial arterial disease in East Asians and advanced imaging techniques. There has been a decrease in intravenous thrombolysis rates, from 12% in 2017-2019 to 10% in 2021, with no improvements in door-to-needle and door-to-puncture times, worsened by the coronavirus disease 2019 pandemic. While the use of aspirin plus clopidogrel for non-cardioembolic stroke and direct oral anticoagulants for atrial fibrillation is well-established, the application of direct oral anticoagulants for non-atrial fibrillation cardioembolic strokes in the acute phase requires further research. The incidence of early neurological deterioration (13%) and the cumulative incidence of recurrent stroke at 3 months (3%) align with global figures. Favorable outcomes at 3 months (63%) are comparable internationally, yet the lack of improvement in dependency at 3 months highlights the need for advancements in acute stroke care.

Body mass index and waist circumference as predictors of recurrent vascular events after a recent ischemic stroke.

OBJECTIVES: Although elevated body mass index (BMI) is a risk factor for stroke, it appears to protect against recurrent vascular events. We tried to evaluate BMI and waist circumference (WC) as predictors of recurrent stroke and vascular events in a cohort of stroke survivors who were followed for 12 months. MATERIALS AND METHODS: We analyzed the stroke registry database of 6 hospitals and recruited patients with a first-ever stroke who were admitted from January 2011 to November 2019 and had their BMI and WC measured. Cox proportional hazards models were used to compare risks of recurrent stroke and major vascular events (a composite of stroke, myocardial infarction, or vascular death) between different BMI and WC quintiles. Reference categories were patients in the lowest quintiles. RESULTS: A total of 14 781 patients were analyzed. Patients in the second quintile of BMI had the lowest risk of recurrent stroke (adjusted hazard ratio (HR) 0.72; 95% confidence interval (CI) 0.58-0.91); patients in the highest quintile had the lowest risk or a major vascular event (adjusted HR 0.71; 95% CI 0.58-0.86). Patients in the fourth quintile of WC had the lowest risk of recurrent stroke (adjusted HR 0.73; 95% CI 0.59-0.91) and a major vascular event (adjusted HR 0.72; 95 % CI 0.60-0.86). CONCLUSIONS: Our results show favorable effects of excess body weight and intra-abdominal fat on avoidance of vascular events after stroke and a favorable effect of intra-abdominal fat on avoidance of recurrent stroke.

Association of ischemic stroke onset time with presenting severity, acute progression, and long-term outcome: A cohort study.

BACKGROUND: Preclinical 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 FINDINGS: In 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. CONCLUSIONS: Night-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.

Relation of Pre-Stroke Aspirin Use With Cerebral Infarct Volume and Functional Outcomes.

OBJECTIVE: We investigated (1) the associations of pre-stroke aspirin use with thrombus burden, infarct volume, hemorrhagic transformation, early neurological deterioration (END), and functional outcome, and (2) whether stroke subtypes modify these associations in first-ever ischemic stroke. METHODS: This multicenter magnetic resonance imaging (MRI)-based study included 5,700 consecutive patients with acute first-ever ischemic stroke, who did not undergo intravenous thrombolysis or endovascular thrombectomy, from May 2011 through February 2014. Propensity score-based augmented inverse probability weighting was performed to estimate adjusted effects of pre-stroke aspirin use. RESULTS: The mean age was 67 years (41% women), and 15.9% (n = 907) were taking aspirin before stroke. Pre-stroke aspirin use (vs nonuse) was significantly related to a reduced infarct volume (by 30%), particularly in large artery atherosclerosis stroke (by 45%). In cardioembolic stroke, pre-stroke aspirin use was associated with a ~50% lower incidence of END (adjusted difference = -5.4%, 95% confidence interval [CI] = -8.9 to -1.9). Thus, pre-stroke aspirin use was associated with ~30% higher likelihood of favorable outcome (3-month modified Rankin Scale score < 3), particularly in large artery atherosclerosis stroke and cardioembolic stroke (adjusted difference = 7.2%, 95% CI = 1.8 to 12.5 and adjusted difference = 6.4%, 95% CI = 1.7 to 11.1, respectively). Pre-stroke aspirin use (vs nonuse) was associated with 85% less frequent cerebral thrombus-related susceptibility vessel sign (SVS) in large artery atherosclerosis stroke (adjusted difference = -1.4%, 95% CI = -2.1 to -0.8, p < 0.001) and was associated with ~40% lower SVS volumes, particularly in cardioembolic stroke (adjusted difference = -0.16 cm3 , 95% CI = -0.29 to -0.02, p = 0.03). Moreover, pre-stroke aspirin use was not significantly associated with hemorrhagic transformation (adjusted difference = -1.1%, p = 0.09). INTERPRETATION: Pre-stroke aspirin use associates with improved functional independence in patients with first-ever ischemic large arterial stroke by reducing infarct volume and/or END, likely by decreasing thrombus burden, without increased risk of hemorrhagic transformation. ANN NEUROL 2021;90:763-776.

Effect of Heart Rate on Stroke Recurrence and Mortality in Acute Ischemic Stroke With Atrial Fibrillation.

Background and Purpose- There is a paucity of information about the role of resting heart rate in the prediction of outcome events in patients with ischemic stroke with atrial fibrillation. We aimed to investigate the relationships between the level and variability of heart rate in the acute stroke period and stroke recurrence and mortality after acute ischemic stroke in patients with atrial fibrillation. Methods- Acute patients with ischemic stroke who had atrial fibrillation and were hospitalized within 48 hours of stroke onset were identified from a multicenter prospective stroke registry database. The acute stroke period was divided into early (within 24 hours of hospitalization) and late (72 hours to 7 days from onset) stages, and data on heart rate in both stages were collected. Moreover, the level and variability of heart rate were assessed using mean values and coefficients of variation. Outcome events were prospectively monitored up to 1 year after the index stroke. Results- Among 2046 patients eligible for the early acute stage analysis, 102 (5.0%) had a stroke recurrence, and 440 (21.5%) died during the first year after stroke. A statistically significant nonlinear J-shaped association was observed between mean heart rate and mortality (P<0.04 for quadratic and overall effect) but not between mean heart rate and stroke recurrence (P>0.1 for quadratic and overall effect). The nonlinear and overall effects of the coefficients of variation of heart rate were not significant for all outcome variables. The same results were observed in the late acute stage analysis (n=1576). Conclusions- In patients with atrial fibrillation hospitalized for acute ischemic stroke, the mean heart rate during the acute stroke period was not associated with stroke recurrence but was associated with mortality (nonlinear, J-shaped association). The relationships between heart rate and outcomes were not observed with respect to heart rate variability.

Comparative Effectiveness of Dual Antiplatelet Therapy With Aspirin and Clopidogrel Versus Aspirin Monotherapy in Acute, Nonminor Stroke: A Nationwide, Multicenter Registry-Based Study.

Background and Purpose- This study aimed to compare the effectiveness of dual antiplatelet therapy with clopidogrel plus aspirin (DAPT) with that of aspirin monotherapy (AM) in patients with acute, nonminor, and noncardioembolic stroke. Methods- Using a prospective, nationwide, multicenter stroke registry database, acute (within 24 hours of onset), nonminor (baseline National Institutes of Health Stroke Scale score, 4-15), and noncardioembolic stroke patients were identified. Propensity scores using inverse probability of treatment weighting were used to adjust baseline imbalances between the DAPT and AM groups. A primary outcome measure was a composite of all types of stroke (ischemic and hemorrhagic), myocardial infarction, and all-cause mortality within 3 months of stroke onset. Results- Among the 4461 patients meeting the eligibility criteria (age, 69±13 years; men, 57.7%), 52.5% (n=2340) received AM, and 47.5% (n=2121) received DAPT. The primary outcome event was not significantly different between the DAPT group and the AM group (20.9% versus 22.6%, P=0.13). The event rates of all types of stroke were also not different between the 2 groups (19.3% versus 20.1%, P=0.35), while all-cause mortality was significantly lower in the DAPT group than in the AM group (3.4% versus 4.9%, P=0.02). In the propensity-weighted Cox proportional hazards models with robust estimation, DAPT did not reduce the risk of the primary outcome event (hazards ratio, 0.91; 95% CI, 0.79-1.04) but did reduce the risk of all-cause mortality (0.69; 0.49-0.97). There was no treatment heterogeneity among the predefined subgroups, although the potential benefits of DAPT were suggested in subpopulations of moderate-to-severe relevant arterial stenosis and relatively severe deficits (National Institutes of Health Stroke Scale score, 12-15). Conclusions- Compared to AM, clopidogrel plus aspirin did not reduce the risk of the primary outcome event during the first 3 months after a nonminor, noncardioembolic, ischemic stroke.

Comparative Effectiveness of Aspirin and Clopidogrel Versus Aspirin in Acute Minor Stroke or Transient Ischemic Attack.

Background and Purpose- This study aimed to compare the effectiveness of dual antiplatelet therapy with clopidogrel-aspirin to that of aspirin monotherapy in patients with acute minor cerebral ischemia using a prospective, nationwide, multicenter, stroke registry database in South Korea. Methods- CHANCE trial (Clopidogrel in High-Risk Patients With Acute Nondisabling Cerebrovascular Events)-like patients who met eligibility criteria modeled on the CHANCE trial eligibility criteria, including (1) acute minor ischemic stroke defined as National Institutes of Health Stroke Scale score ≤3 or lesion positive transient ischemic attack within 24 hours of onset and (2) noncardioembolic stroke mechanism. Propensity scores using the inverse probability of treatment weighting was used to adjust for baseline imbalances. The primary outcome was the composite of all stroke (ischemic and hemorrhagic), myocardial infarction, and vascular death by 3 months. Results- Among 5590 patients meeting the eligibility criteria, age was 64±13 year and 62.6% were male. Aspirin and combination of clopidogrel-aspirin were administered in 66.1% and 33.9% of patients, respectively. In unadjusted analysis, rates of the 3-month primary vascular event outcome were lower with clopidogrel-aspirin versus aspirin, 9.9% versus 12.2% (hazard ratio, 0.79 [0.67-0.95]). In propensity-weighted Cox proportional hazards regression with robust estimation, clopidogrel-aspirin was associated with a lower risk of the primary vascular event outcome (hazard ratio, 0.76 [0.63-0.92]) and all stroke events (hazard ratio, 0.74 [0.61-0.90]). Among 6 predefined subgroup analyses, 3 showed potential modification of treatment effect, with lesser benefit associated with the absence of prior antiplatelet use (Pinteraction=0.01) and younger age (<75 years, Pinteraction=0.07), and absence of benefit associated with small vessel occlusion subtype (Pinteraction=0.08). Conclusions- Dual antiplatelet therapy with aspirin and clopidogrel was associated with reduced stroke, myocardial infarction, and vascular death in the 3 months following a presenting minor, noncardioembolic ischemic stroke. Benefits may be particularly magnified in patients with a history of prior antiplatelet therapy, older age, and nonsmall vessel disease stroke mechanism.

Magnetic Resonance Imaging Versus Computed Tomography Angiography Based Selection for Endovascular Therapy in Patients With Acute Ischemic Stroke.

Background and Purpose- Randomized trials comparing the use of multimodal magnetic resonance imaging (MRI) to multimodal computed tomography (CT)/ CT angiography (CTA) for selecting candidates for endovascular therapy (EVT) have not been reported. This study aimed to elucidate whether MRI-based selection for EVT is safe and effective within and after a 6-hour time window compared with conventional CTA-based selection. Methods- Data from a prospective, nationwide, multicenter stroke registry were analyzed. Workflow timelines were compared between patients selected for EVT based on MRI (the MRI group) and CTA (the CTA group). Multivariable ordinal and binary logistic regression analyses were performed to explore the relationships between decision imaging for EVT and clinical outcomes, including good and excellent outcomes (modified Rankin Scale scores of 0-2 and 0-1, respectively) at 3-month, modified Rankin Scale score distributions and safety outcomes (symptomatic intracranial hemorrhage [SICH] and mortality). Results- Ultimately, 1265 patients (age, 69±12 yrs; men, 55%) were enrolled in this study. The median National Institutes of Health Stroke Scale score was 15 (11-19). All workflow time metrics were significantly delayed in the MRI group compared with the CTA group. There was no difference in good 3-month outcomes in patients arriving within 6 hours of onset between the MRI and CTA groups (38.1% versus 38.5%), but SICH and mortality rates were lower in the MRI group than the CTA group (3.8% versus 7.7%, P=0.01 for SICH; 15.4% versus 20.9%, P=0.04 for mortality). In the multivariable analysis, decision imaging was not significantly associated with 3-month functional outcomes (all P>0.1) or mortality ( P=0.051); however, the MRI group was less likely to develop SICH than the CTA group ( P=0.01; odds ratio, 0.34 [95% CI, 0.17-0.77]). Conclusions- Our study found MRI-based selection for EVT was not associated with improving functional outcome compared with CT-based selection, but may be better at reducing the risk of SICH, despite the delays in all workflow time metrics.

Trajectory Groups of 24-Hour Systolic Blood Pressure After Acute Ischemic Stroke and Recurrent Vascular Events.

Background and Purpose- Blood pressure dynamics in patients with acute ischemic stroke may serve as an important modifiable and prognostic factor. Methods- A total of 8376 patients with acute ischemic stroke were studied from a prospective multicenter registry. Patients were eligible if they had been admitted within 24 hours of symptom onset and had ≥5 systolic blood pressure (SBP) measurements during the first 24 hours of hospitalization. SBP trajectory groups in the first 24 hours were identified using the TRAJ procedure in SAS software with delta-Bayesian Information Criterion and prespecified modeling parameters. Vascular events, including recurrent stroke, myocardial infarction, and death, were prospectively collected. The risk of having vascular events was calculated using the frailty model to adjust for clustering by hospital. Results- The group-based trajectory model classified patients with acute ischemic stroke into 5 SBP trajectory groups: low (22.3%), moderate (40.8%), rapidly stabilized (11.9%), acutely elevated (18.5%), and persistently high (6.4%) SBP. The risk of having vascular events was increased in the acutely elevated (hazard ratio, 1.28 [95% confidence interval, 1.12-1.47]) and the persistently high SBP groups (hazard ratio, 1.67 [95% confidence interval, 1.37-2.04]) but not in the rapidly stabilized group (hazard ratio, 1.13 [95% confidence interval, 0.95-1.34]), when compared with the moderate SBP group. Conclusions- SBP during the first 24 hours after acute ischemic stroke may be categorized into distinct trajectory groups, which differ in relation to stroke characteristics and frequency of subsequent recurrent vascular event risks. The findings may help to recognize potential candidates for future blood pressure control trials.

Predictive Value of Pulse Pressure in Acute Ischemic Stroke for Future Major Vascular Events.

BACKGROUND AND PURPOSE: This study aimed to investigate whether pulse pressure (PP) obtained during the acute stage of ischemic stroke can be used as a predictor for future major vascular events. METHODS: Using a multicenter prospective stroke registry database, patients who were hospitalized for ischemic stroke within 48 hours of onset were enrolled in this study. We analyzed blood pressure (BP) data measured during the first 3 days from onset. Primary and secondary outcomes were time to a composite of stroke recurrence, myocardial infarction, all-cause death, and time to stroke recurrence, respectively. RESULTS: Of 9840 patients, 4.3% experienced stroke recurrence, 0.2% myocardial infarction, and 7.3% death during a 1-year follow-up period. In Cox proportional hazards models including both linear and quadratic terms of PP, PP had a nonlinear J-shaped relationship with primary (for a quadratic term of PP, P=0.004) and secondary (P<0.001) outcomes. The overall effects of PP and other BP parameters on primary and secondary outcomes were also significant (P<0.05). When predictive power of BP parameters was compared using a statistic of -2 log-likelihood differences, PP was a stronger predictor than systolic BP (8.49 versus 5.91; 6.32 versus 4.56), diastolic BP (11.42 versus 11.05; 10.07 versus 4.56), and mean atrial pressure (8.75 versus 5.91; 7.03 versus 4.56) for the primary and secondary outcomes, respectively. CONCLUSIONS: Our study shows that PP when measured in the acute period of ischemic stroke has nonlinear J-shaped relationships with major vascular events and stroke recurrence, and may have a stronger predictive power than other commonly used BP parameters.

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.

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.

One-Year Outcomes After Minor Stroke or High-Risk Transient Ischemic Attack: Korean Multicenter Stroke Registry Analysis.

BACKGROUND AND PURPOSE: Patients with minor ischemic stroke or transient ischemic attack are at high risk of recurrent stroke and vascular events, which are potentially disabling or fatal. This study aimed to evaluate contemporary subsequent vascular event risk after minor ischemic stroke or transient ischemic attack in Korea. METHODS: Patients with minor ischemic stroke or high-risk transient ischemic attack admitted within 7 days of symptom onset were identified from a Korean multicenter stroke registry database. We estimated 3-month and 1-year event rates of the primary outcome (composite of stroke recurrence, myocardial infarction, or all-cause death), stroke recurrence, a major vascular event (composite of stroke recurrence, myocardial infarction, or vascular death), and all-cause death and explored differences in clinical characteristics and event rates according to antithrombotic strategies at discharge. RESULTS: Of 9506 patients enrolled in this study, 93.8% underwent angiographic assessment and 72.7% underwent cardiac evaluations; 25.1% had symptomatic stenosis or occlusion of intracranial arteries. At discharge, 95.2% of patients received antithrombotics (antiplatelet polytherapy, 37.1%; anticoagulation, 15.3%) and 86.2% received statins. The 3-month cumulative event rate was 5.9% for the primary outcome, 4.3% for stroke recurrence, 4.6% for a major vascular event, and 2.0% for all-cause death. Corresponding values at 1 year were 9.3%, 6.1%, 6.7%, and 4.1%, respectively. Patients receiving nonaspirin antithrombotic strategies or no antithrombotic agent had higher baseline risk profiles and at least 1.5× higher event rates for clinical event outcomes than those with aspirin monotherapy. CONCLUSIONS: Contemporary secondary stroke prevention strategies based on thorough diagnostic evaluation may contribute to the low subsequent vascular event rates observed in real-world clinical practice in Korea.

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.

Utility of Items of Baseline National Institutes of Health Stroke Scale as Predictors of Functional Outcomes at Three Months after Mild Ischemic Stroke.

BACKGROUND: Predicting outcomes of acute stroke patients initially presenting with mild neurologic deficits is crucial in decision making regarding thrombolytic therapy. We examined the utility of individual National Institutes of Health Stroke Scale (NIHSS) score items or clusters of items as predictors of functional outcomes at 3 months after mild stroke. METHODS: Using a multicenter stroke registry database, we identified patients with acute ischemic stroke who presented within 4.5 hours of symptom onset and had baseline NIHSS scores less than or equal to 5. Functional outcomes at 3 months were dichotomized as favorable (modified RankinScale [mRS] score 0 or 1) or unfavorable (mRS 2-6). Individual NIHSS items, clusters of items, and the total score were tested for their ability to predict outcomes in multivariable models. Area under the receiver operating characteristic curve (AUC) was used to assess model performance. RESULTS: Of the 2209 patients who met eligibility criteria, 588 (26.6%) exhibited unfavorable functional outcomes at 3 months. Of the 15 items of the NIHSS, all except item 8 (sensory) and item 11 (extinction) were significantly associated with unfavorable functional outcomes in bivariate analysis (P's < .05). Among the multivariable models, the model with the total NIHSS score exhibited an AUC similar to that of the model with all NIHSS items in predicting functional outcomes (.758 [95% confidence interval .739-.775] versus .759 [.740-.776]; P = .75 for pairwise comparison). CONCLUSIONS: Simply using the total NIHSS score was as effective as using all individual items in predicting outcomes of mild stroke patients.

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.

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.

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.

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.

Development of a Swine Benign Biliary Stricture Model Using Endoscopic Biliary Radiofrequency Ablation.

The large animal model with benign biliary stricture (BBS) is essential to undergo experiment on developing new devices and endoscopic treatment. This study conducted to establish a clinically relevant porcine BBS model by means of endobiliary radiofrequency ablation (RFA). Endoscopic retrograde cholangiography (ERC) was performed on 12 swine. The animals were allocated to three groups (60, 80, and 100 W) according to the electrical power level of RFA electrode. Endobiliary RFA was applied to the common bile duct for 60 seconds using an RFA catheter that was endoscopically inserted. ERC was repeated two and four weeks, respectively, after the RFA to identify BBS. After the strictures were identified, histologic evaluations were performed. On the follow-up ERC two weeks after the procedure, a segmental bile duct stricture was observed in all animals. On microscopic examination, severe periductal fibrosis and luminal obliteration with transmural inflammation were demonstrated. Bile duct perforations occurred in two pigs (100 W, n = 1; 80 W, n = 1) but there were no major complications in the 60 W group. The application of endobiliary RFA with 60 W electrical power resulted in a safe and reproducible swine model of BBS.