The aim of the Part I of Stroke Statistics in Korea is to summarize nationally representative data of the epidemiology and risk factors of stroke in a single document. Every year, approximately 105,000 people experience a new or recurrent stroke and more than 26,000 die of stroke, which indicates that every 5 minutes stroke attacks someone and every 20 minutes stroke kills someone in Korea. Stroke accounts for roughly 1 of every 10 deaths. The estimated stroke prevalence is about 795,000 in people aged ≥30 years. The nationwide total cost for stroke care was 3,737 billion Korean won (US$3.3 billion) in 2005. Fortunately, the annual stroke mortality rate decreased substantially by 28.3% during the first decade of the 21th century (53.2/100,000 in 2010). Among OECD countries, Korea had the lowest in-hospital 30-day case-fatality rate for ischemic stroke and ranked third lowest for hemorrhagic stroke in 2009. The proportion of ischemic stroke has steadily increased and accounted for 76% of all strokes in 2009. According to hospital registry studies, the 90-day mortality rate was 3-7% for ischemic stroke and 17% for intracerebral hemorrhage. For risk factors, among Korean adults ≥30 years of age, one in 3-4 has hypertension, one in 10 diabetes, and one in 7 hypercholesterolemia. One in 3 Korean adults ≥19 years of age is obese. Over the last 10 years, the prevalence of hypertension slightly decreased, but the prevalence of diabetes, hypercholesterolemia, and obesity increased. Smoking prevalence in men has decreased, but is still as high as 48%. This report could be a valuable resource for establishing health care policy and guiding future research directions.

Characteristics of stroke cases, acute stroke care, and outcomes after stroke differ according to geographical and cultural background. To provide epidemiological and clinical data on stroke care in South Korea, we analyzed a prospective multicenter clinical stroke registry, the Clinical Research Center for Stroke-Fifth Division (CRCS-5). Patients were 58% male with a mean age of 67.2±12.9 years and median National Institutes of Health Stroke Scale score of 3 [1-8] points. Over the 6 years of operation, temporal trends were documented including increasing utilization of recanalization treatment with shorter onset-to-arrival delay and decremental length of stay. Acute recanalization treatment was performed in 12.7% of cases with endovascular treatment utilized in 36%, but the proportion of endovascular recanalization varied across centers. Door-to-IV alteplase delay had a median of 45 [33-68] min. The rate of symptomatic hemorrhagic transformation (HT) was 7%, and that of any HT was 27% among recanalization-treated cases. Early neurological deterioration occurred in 15% of cases and were associated with longer length of stay and poorer 3-month outcomes. The proportion of mRS scores of 0-1 was 42% on discharge, 50% at 3 months, and 55% at 1 year after the index stroke. Recurrent stroke up to 1 year occurred in 4.5% of patients; the rate was higher among older individuals and those with neurologically severe deficits. The above findings will be compared with other Asian and US registry data in this article.

Background: Post-stroke cognitive impairment (PSCI) occurs in approximately half of ischemic stroke survivors. Infarct location is a potential determinant of PSCI, but a comprehensive map of strategic infarct locations is lacking. In this large-scale multicenter lesion-symptom mapping study, we aimed to identify infarct locations most strongly predictive of PSCI, and use this information to develop a prediction model. Methods:We harmonized individual patient data from twelve cohorts through the Meta-VCI-Map consortium. Patients with acute symptomatic infarcts on CT/MRI and cognitive assessment <1 year poststroke were eligible. PSCI was defined as impairment in ≥1 cognitive domains on neuropsychological assessment or impairment on the Montreal Cognitive Assessment. Voxel-based lesion-symptom mapping (VLSM) was used to calculate voxel-wise odds ratios for PSCI. For the prediction model, a "location impact score" on a five-point scale was derived from the VLSM results. Combined internal-external validation was performed using leave-one-cohort-out cross-validation for all twelve cohorts. Findings:In our combined sample of 2950 patients (age 67±12 years, 39% female), 44% had PSCI. We achieved almost complete lesion coverage of the brain in our analyses (87%). Infarcts in the left frontotemporal lobes, left thalamus, and right parietal lobe were strongly associated with PSCI (False Discovery Rate corrected q<0•01; voxel-wise odds ratios >20). These strategic regions were mapped onto a three-dimensional brain template to visualize PSCI risk per brain region. The location impact score showed good correspondence between predicted and observed risk across cohorts after adjusting for cohortspecific PSCI occurrence. Interpretation:This study provides the first comprehensive map of strategic infarct locations associated with risk of PSCI. A location impact score was derived from this map that robustly predicted PSCI across cohorts and can be applied by clinicians to identify individual patients at risk of PSCI.

Background and Purpose-An optimal strategy for management of symptomatic intracranial atherosclerotic stenosis (ICAS) has not yet been established. We compared the efficacy of 2 combinations of antiplatelets, aspirin plus cilostazol (cilostazol group) verus aspirin plus clopidogrel (clopidogrel group), on the progression of ICAS, which is known to be associated with clinical stroke recurrence. Methods-In this investigator-initiated double-blind trial, 457 patients with acute symptomatic stenosis in the M1 segment of the middle cerebral artery or the basilar artery were randomly allocated into either a cilostazol group or a clopidogrel group. After 7 months of treatment, follow-up MR angiogram and MRI were performed. The primary end point was the progression of ICAS in comparison with stenosis on the baseline MR angiogram. Secondary end points included the occurrence of new ischemic lesions on MRI, composite of cardiovascular events, and major bleeding complications. Results-Cardiovascular events occurred in 15 of 232 patients (6.4%) in the cilostazol group and 10 of 225 (4.4%) in the clopidogrel group (Pϭ0.312). Cilostazol did not reduce the progression of symptomatic ICAS (20 of 202) compared to clopidogrel (32 of 207) (odds ratio, 0.61; Pϭ0.092), although favorable changes in serum lipoproteins were observed in the cilostazol group. There were no significant differences between the 2 groups with respect to new ischemic lesions (18.7% versus 12.0%; Pϭ0.078) and major hemorrhagic complications (0.9% versus 2.6%; Pϭ0.163). Conclusions-This trial failed to show significant difference in preventing progression of ICAS and new ischemic lesions between the 2 combination antiplatelet therapies in the patients with symptomatic ICAS. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00130039.

Our results documented obesity paradox in stroke survivors, regardless of age and causes of death, and it became evident a sufficient time after stroke onset.

There are limited data on the utilization of diagnostics and the variation of treatments at the national level in acute stroke care. Clinical Research Center for Stroke--5th division stroke registry aimed to describe stroke statistics and quality of care in Korea and to implement quality indicators. Clinical Research Center for Stroke--5th division registry was established in April 2008 and covers pretreatment demographics, medical and stroke severity measures, diagnostic evaluation, hyperacute revascularization, in-hospital management, discharge disposition, quality indicators, and long-term functional outcomes. Consecutive stroke cases from 12 participating centers are registered to a web-based database. Meticulous data management and auditing policy were applied. A total of 14,792 ischemic stroke cases were enrolled from April 2008 to January 2012. The median National Institutes of Health Stroke Scale score was 4 at admission, with median delay of onset to arrival of 14 h. Rate of risk factor management before stroke exceeds more than 80% for hypertension and diabetes. Revascularization procedures were performed in 1736 subjects (12%), and 34% were endovascular (n = 598). Substantial variability was noted in the preferred modality of hyperacute revascularization (range of endovascular recanalization = 6-60%), use of computed tomography (30-93%), and perfusion imaging (2-96%). The Clinical Research Center for Stroke--5th division registry documented that the current practice of acute stroke care in South Korea largely met the standard of guidelines, but variability of practice still remains. The registry would provide an opportunity to evaluate the quality of stroke care across South Korea and compare it with that of other countries.

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 outcome...

Background and Purpose-The low-dose (0.6 mg/kg) alteplase strategy to treat acute ischemic stroke patients became widespread in East Asian countries, without rigorous testing against standard-dose (0.9 mg/kg) alteplase treatment.Our aim was to investigate the comparative effectiveness and safety of the low-dose versus standard-dose intravenous alteplase strategy. Methods-A total of 1526 acute ischemic stroke patients who qualified for intravenous alteplase and treated within 4.5 hours were identified from a prospective, multicenter, and nationwide stroke registry database. Primary outcomes were a modified Rankin scale score of 0 to 1 at 3 months after stroke and occurrence of symptomatic hemorrhagic transformation. Inverse probability of low-dose alteplase weighting by propensity scores was used to remove baseline imbalances between the 2 groups, and variation among centers were also accounted using generalized linear mixed models with a random intercept. Results-Low-dose intravenous alteplase was given to 450 patients (29.5%) and standard-dose intravenous alteplase to 1076 patients (70.5%). Low-dose alteplase treatment was comparable to standard-dose therapy according to the following adjusted outcomes and odds ratios (95% confidence intervals): modified Rankin scale score 0 to 1 at 3 months and 0.95 (0.68-1.32); modified Rankin scale 0 to 2 at 3 months and 0.84 (0.62-1.15); symptomatic hemorrhagic transformation and 1.05 (0.65-1.70); and 3-month mortality and 0.54 (0.35-0.83). The associations were unchanged when the analysis was limited to those without endovascular recanalization. Conclusions-The low-dose alteplase strategy was comparable to the standard-dose treatment in terms of the effectiveness and safety. Concern for hemorrhagic transformation and potentially higher biological activity of alteplase in Asian populations have led to use of lower-dose intravenous (IV) alteplase in this region.3 A series of single-arm trials conducted in Japan showed that the low-dose alteplase (0.6 mg/kg) was feasible and patients treated with it had similar outcomes to historical controls treated with standard-dose IV tissue-type plasminogen activator (0.9 mg/kg).4-7 The low-dose strategy spread rapidly among Asian countries and is estimated to be used in >40% of acute ischemic stroke thrombolysis cases. 8-12The efficacy of the low-dose alteplase strategy has been challenged, however, based on a lack of concomitant controls and 2 recent publications from Mainland China and Taiwan, suggesting contrary conclusions in relation to the efficacy of low-dose alteplase.13,14 Also, the advent of efficacious and safe endovascular devices and prior use of IV thrombolysis further highlights the need for a safe and effective alteplase strategy. [15][16][17] In the absence of a large-scale clinical trial, observational data from a large clinical registry can be useful for assessing alternative treatment strategies. 18 The aim of the current study is to evaluate the comparative effectiveness and safety of low-dose alteplase treatment fo...