Jae-Kwan Cha

Dong-A University, Tsau-liang-hai, Busan, South Korea

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Publications (51)105.97 Total impact

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    ABSTRACT: Experimental studies suggest that pre-stroke statin treatment has a dual effect of neuroprotection during ischemia and neurorestoration after ischemic injury. The aim of this study was to evaluate the effect of pre-stroke statin use on initial stroke severity and early clinical outcome. We used a prospective database enrolling patients with acute ischemic stroke from 12 hospitals in Korea between April 2008 and January 2012. Primary endpoint was the initial stroke severity as measured by the National Institutes of Health Stroke Scale (NIHSS) score. Secondary endpoints were good outcome (modified Rankin Scale [mRS], 0-2) and overall mRS distribution at discharge. Multivariable regression model and propensity score (PS) matching were used for statistical analyses. Among the 8340 patients included in this study, 964 patients (11.6 %) were pre-stroke statin users. The initial NIHSS score (mean [95 % CI]) was lower among pre-stroke statin users vs. non-users in multivariable analysis (5.7 [5.2-6.3] versus 6.4 [5.9-6.9], p = 0.002) and PS analysis (5.2 [4.7-5.7] versus 5.7 [5.4-6.0], p = 0.043). Pre-stroke statin use was associated with increased achievement of mRS 0-2 outcome (multivariable analysis: OR [95 % CI], 1.55 [1.25-1.92], p < 0.001; PS matching: OR [95 % CI], 1.47 [1.16-1.88]; p = 0.002) and favorable shift on the overall mRS distribution (multivariable analysis: OR [95 % CI], 1.29 [1.12-1.51], p = 0.001; PS matching: OR [95 % CI], 1.31 [1.11-1.54]; p = 0.001). Pre-stroke statin use was independently associated with lesser stroke severity at presentation and better early functional recovery in patients with acute ischemic stroke.
    BMC Neurology 07/2015; 15(1):120. DOI:10.1186/s12883-015-0376-3 · 2.49 Impact Factor
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    ABSTRACT: Higher reperfusion rates have been established with endovascular treatment for acute ischemic stroke patients. There are limited data on the comparative performance of mechanical thrombectomy devices. This study aimed to analyse the efficacy and safety of the stent retriever device (Solitaire stent) by comparing procedure time, angiographic outcome, complication rate and long term clinical outcome with previous chemical thrombolysis and mechanical thrombectomy using penumbra system. A retrospective single-center analysis was undertaken of all consecutive patients who underwent chemical thrombolysis and mechanical thrombectomy using Penumbra or Solitaire stent retriever from March 2009 to March 2014. Baseline characteristics, rate of successful recanalization (modified Thrombolysis in Cerebral Infarction score 2b-3), symptomatic intracerebral hemorrhage, procedure time, mortality and independent functional outcomes (mRS ≤2) at 3 month were compared across the three method. Our cohort included 164 patients, mechanical thrombectomy using stent retriever device had a significant impact on recanalization rate and functional independence at 3 months. In unadjusted analysis mechanical thrombectomy using Solitaire stent retriever showed higher recanalization rate than Penumbra system and chemical thrombolysis (75% vs. 64.2% vs. 49.4%, p=0.03) and higher rate of functional independence at 3 month (53.1% vs. 37.7% vs. 35.4%, p=0.213). In view of the interrelationships between all predictors of variables associated with a good clinical outcome, when the chemical thrombolysis was used as a reference, in multiple logistic regression analysis, the use of Solitaire stent retriever showed higher odds of independent functional outcome [odds ratio (OR) 2.62, 95% confidence interval (CI) 0.96-7.17; p=0.061] in comparison with penumbra system (OR 1.57, 95% CI 0.63-3.90; p=0.331). Our initial data suggest that mechanical thrombectomy using stent retriever is superior to the mechanical thrombectomy using penumbra system and conventional chemical thrombolysis in achieving higher rates of reperfusion and better outcomes. Randomized clinical trials are needed to establish the actual benefit to specific patient populations.
    Journal of Korean Neurosurgical Society 05/2015; 57(5):342-9. DOI:10.3340/jkns.2015.57.5.342 · 0.52 Impact Factor
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    ABSTRACT: We hypothesized that the relative cerebral blood volume (rCBV) ratio on perfusion-weighted imaging (PWI) using MRI might serve as a predictor of early recanalization (ER) after intravenous tissue plasminogen activator (IV t-PA) administration for acute ischemic stroke. Patients with acute middle cerebral artery (MCA) ischemic stroke (IS) were enrolled in the study. They were evaluated by MRI, including PWI and diffusion-weighted imaging, before administration of IV t-PA and underwent digital subtraction angiography (DSA) of the brain within 2 h after t-PA administration. We compared the rCBV ratio on PWI between patients with and without ER on DSA and investigated the proportion of patients with an excellent outcome at 90 days after t-PA administration (modified Rankin Scale score 0-1) among those with and without ER. 85 patients with acute MCA IS were included; 16 patients (18.8%) experienced ER on DSA after IV t-PA administration. Patients with ER more frequently had an excellent outcome at 90 days than those without ER. The rCBV ratio on PWI was higher in the ER group (1.01±0.21, p<0.01) than in the non-ER group (0.82±0.18). After adjusting for the presence of atrial fibrillation and the serum glucose level, the rCBV ratio on PWI (OR 1.07; 95% CI 1.02 to 1.12; p<0.01) was a significant independent indicator of ER. The results of this study suggest that the rCBV ratio on PWI might serve as a useful indicator of ER after IV t-PA administration. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
    Journal of Neurointerventional Surgery 01/2015; DOI:10.1136/neurintsurg-2014-011501 · 2.77 Impact Factor
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    ABSTRACT: 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.
    01/2015; 17(1):38-53. DOI:10.5853/jos.2015.17.1.38
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    ABSTRACT: Background: A stroke code can shorten time intervals until intravenous tissue plasminogen activator (IV t-PA) treatment in acute ischemic stroke (AIS). Recently, several reports demonstrated that magnetic resonance imaging (MRI)-based thrombolysis had reduced complications and improved outcomes in AIS despite longer processing compared with computed tomography (CT)-based thrombolysis. Methods: In January 2009, we implemented CODE RED, a computerized stroke code, at our hospital with the aim of achieving rapid stroke assessment and treatment. We included patients with thrombolysis from January 2007 to December 2008 (prestroke code period) and from January 2009 to May 2013 (poststroke code period). The IV t-PA time intervals and 90-day modified Rankin Scale (mRS) scores were collected. Results: During the observation period, 252 patients used IV t-PA under the CODE RED (MRI based: 208; CT based: 44). The remaining 71 patients (MRI based: 53; CT based: 18) received it before the implementation of our stroke code. After implementation of CODE RED, door-to-image time, door-to-needle time, and the onset-to-needle time were significantly reduced by 11, 18, and 22 minutes in MRI-based thrombolysis. Particularly, the proportion of favorable outcome (mRS score 0-2) was significantly increased (from 41.5% to 60.1%, P = .02) in poststroke than in prestroke code period in MRI-based thrombolysis. However, in ordinal regression, the presence of stroke code showed just a trend for favorable outcome (odds ratio, .99-2.87; P = .059) at 90 days of using IV t-PA after correction of age, sex, and National Institutes of Health Stroke Scale. Conclusions: In this study, we demonstrated that a systemized stroke code shortened time intervals for using IV t-PA under MRI screening. Also, our results showed a possibility that a systemized stroke code might enhance the efficacy of MRI-based thrombolysis. In the future, we need to carry out a more detailed prospective study about this notion.
    Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 12/2014; 359(2). DOI:10.1016/j.jstrokecerebrovasdis.2014.09.020 · 1.99 Impact Factor
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    ABSTRACT: We aimed to generate rigorous graphical and statistical reference data based on volumetric measurements for assessing the relative severity of white matter hyperintensities (WMHs) in patients with stroke.
    Stroke 11/2014; 45(12). DOI:10.1161/STROKEAHA.114.006662 · 6.02 Impact Factor
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    ABSTRACT: This study aimed to estimate the population-attributable risks (PARs) of 9 major risk factors for stroke in Korea through a case-control study and to test the feasibility and validity of internet-based control recruitment. Methods: From April 2008 to September 2009, controls were enrolled via internet after providing consent for participation through a web-based survey. The cases included patients who were admitted to the participating centers due to acute stroke or transient ischemic attack within 7 days of onset during the study period. Each control was age- and sex-matched with 2 cases. Adjusted odd ratios, age-standardized prevalence, and PARs were estimated for the 9 major risk factors using the prevalence of risk factors in the control group and the age and sex characteristics from Korea's national census data. Results: In total, 1041 controls were matched to 2082 stroke cases. Because of a shortage of elderly controls in the internet-based recruitment, 248 controls were recruited off-line. The PARs were 23.44%, 10.95%, 51.32%, and 6.35% for hypertension, diabetes, smoking, and stroke history, respectively. Hypercholesterolemia, atrial fibrillation, obesity, coronary heart disease, and a family history of stroke were not associated with stroke. Comparison with education and religion of the control group with that mentioned in the national census data showed a notable difference. Conclusions: The study results imply that internet-based control recruitment for a case-control study requires careful selection of risk factors with high self-awareness and effective strategies to facilitate the recruitment of elderly participants.
    Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 09/2014; 23(10). DOI:10.1016/j.jstrokecerebrovasdis.2014.05.026 · 1.99 Impact Factor
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    ABSTRACT: Background and Purpose In order to improve inter-rater reliability and minimize diagnosis of undetermined etiology for stroke subtype classification, using a stroke registry, we developed and implemented a magnetic resonance imaging (MRI)-based algorithm for acute ischemic stroke subtype classification (MAGIC). Methods We enrolled patients who experienced an acute ischemic stroke, were hospitalized in the 14 participating centers within 7 days of onset, and had relevant lesions on MR-diffusion weighted imaging (DWI). MAGIC was designed to reflect recent advances in stroke imaging and thrombolytic therapy. The inter-rater reliability was compared with and without MAGIC to classify the Trial of Org 10172 in Acute Stroke Treatment (TOAST) of each stroke patient. MAGIC was then applied to all stroke patients hospitalized since July 2011, and information about stroke subtypes, other clinical characteristics, and stroke recurrence was collected via a web-based registry database. Results The overall intra-class correlation coefficient (ICC) value was 0.43 (95% CI, 0.31-0.57) for MAGIC and 0.28 (95% CI, 0.18-0.42) for TOAST. Large artery atherosclerosis (LAA) was the most common cause of acute ischemic stroke (38.3%), followed by cardioembolism (CE, 22.8%), undetermined cause (UD, 22.2%), and small-vessel occlusion (SVO, 14.6%). One-year stroke recurrence rates were the highest for two or more UDs (11.80%), followed by LAA (7.30%), CE (5.60%), and SVO (2.50%). Conclusions Despite several limitations, this study shows that the MAGIC system is feasible and may be helpful to classify stroke subtype in the clinic.
    09/2014; 16(3):161-72. DOI:10.5853/jos.2014.16.3.161
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    ABSTRACT: Background Anticoagulation effectively prevents cardioembolic stroke in atrial fibrillation (AF) patients, whereas it is less effective than antiplatelet therapy (AT) in noncardioembolic stroke prevention. We hypothesized that the ischemic lesion pattern and vascular patency would differ according to the antithrombotic treatment status in AF patients. Methods The medical records of 1078 acute ischemic stroke patients with AF were retrospectively reviewed. Patients were classified according to medication at stroke onset: (1) optimal anticoagulation (OAC; international normalized ratio [INR] 1.7-3.0; n = 36); (2) suboptimal anticoagulation (SOAC; INR ≤1.7; n = 134); (3) AT (n = 285); and (4) control (no antithrombotic medication; n = 623). Imaging and clinical variables of each group were compared with that of controls. Results Small cortical or single subcortical infarctions were more common in the OAC group than in controls (6% vs. 1% and 22% vs. 8%, respectively; standardized residual, 2.4 and 2.8). Multicirculatory infarctions were less common in the OAC group than in controls (0% vs. 11%; standardized residual, −2.0). Obstruction of the corresponding artery was less common in the OAC group than in controls (26.5% vs. 46.5%, P = .02). Initial neurologic severity was lower in the OAC and AT groups than in controls (P = .01 and .03, respectively). OAC and AT were independently associated with favorable functional outcome at 3-months (P = .015 and <.001, respectively). Conclusions Ischemic stroke can occur during OAC in AF patients. Small cortical or single subcortical lesions were more common than typical cardioembolic lesion patterns. OAC and AT were protective against severe neurologic deficit and independently associated with favorable outcome, but SOAC was not.
    Journal of Stroke and Cerebrovascular Diseases 09/2014; 23(8). DOI:10.1016/j.jstrokecerebrovasdis.2014.03.011 · 1.99 Impact Factor
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    ABSTRACT: Referral from other hospitals is one of the primary causes of delayed thrombolysis therapy after acute ischemic stroke (AIS). We aimed to evaluate whether direct access to a hospital offering intravenous thrombolysis therapy was associated with good functional outcome in AIS patients treated with thrombolysis. We enrolled patients who received intravenous thrombolysis within 3 hours of symptom onset at our stroke center. We divided these patients into two groups: those with a direct admission to our stroke center and those with indirect admission by referral from other community hospitals. We investigated onset-to-door time and onset-to-recombinant tissue plasminogen activator (rtPA) time according to admission mode. We then assessed the association between a direct admission and favorable outcome at 90 days. A total of 232 patients (mean age of 66.6 years, median National Institutes of Health Stroke Scale score of 10) were included. A total of 48.7% of AIS patients treated with intravenous thrombolytic therapy were transferred from other hospitals. Patients who were directly admitted to our stroke center had a shorter onset-to-door time (61 versus 120 minutes, p < 0.001) and onset-to-rtPA time (103 versus 155 minutes, p < 0.001) than those referred from other hospitals. Direct admission was associated with a good outcome with an odds ratio of 2.03 (95% confidence interval 1.051–3.917, p = 0.035), after adjusting for baseline variables. Thrombolysis after direct admission to a hospital offering intravenous thrombolysis therapy could shorten onset-to-rtPA time and improve stroke outcome in patients with AIS.
    Journal of Clinical Neuroscience 08/2014; 21(8). DOI:10.1016/j.jocn.2014.03.014 · 1.32 Impact Factor
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    ABSTRACT: Background and Purpose-In 2008, the Ministry of Health and Welfare of South Korea initiated the Regional Comprehensive Stroke Center (CSC) program to decrease the incidence and mortality of stroke nationwide. We evaluated the performance of acute ischemic stroke management after the Regional CSC program was introduced. Methods-The Ministry of Health and Welfare established 9 Regional CSCs in different provinces from 2008 to 2010. All Regional CSCs have been able to execute the critical processes independently for stroke management since 2011. The Ministry of Health and Welfare was responsible for program development and financial support, the Regional CSC for program execution, and the Korea Centers for Disease Control and Prevention for auditing the execution. We analyzed prospectively collected data on the required indices from 2011 and repeated the analysis the following year for comparison. Results-After the Regional CSCs were established, the first brain image was taken within 1 hour from arrival at the emergency room for all patients with stroke; the length of hospital stay decreased from 14 to 12 days; for the rapid execution of thrombolysis, the first brain image was taken within 12 minutes; intravenous and intra-arterial thrombolysis were started within 40 and 110 minutes, respectively, after emergency room arrival; and the hospital stay of thrombolytic patients decreased from 19 to 15 days. Conclusions-The Regional CSC program has improved the performance of acute stroke management in South Korea and can be used as a model for rapidly improving stroke management.
    Stroke 07/2014; 45(8). DOI:10.1161/STROKEAHA.114.006134 · 6.02 Impact Factor
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    ABSTRACT: Objective: In this study, we evaluated the relationship between the rCBV (regional cerebral blood flow volume) ratio on perfusion-weighted imaging (PWI) and the extent of collateral flow on conventional angiography. Methods: We recruited 98 patients with AIS (within 24 h after ischemic events). All the patients were evaluated by MRI, including PWI and diffusion-weighted imaging (DWI), and underwent digital subtraction angiography (DSA) of the brain. We hypothesized that the rCBV ratio on PWI could reveal the extent of the blood flow and predict early neurological deterioration (END) within 7 days after AIS. Results: The rCBV ratio on PWI was significantly correlated with its extent on DSA (p < 0.01). During the observation period, 24 patients (24.5%) experienced END. The univariate analysis revealed that severe neurological deficit at admission (p < 0.01), the volume of the ischemic lesion on DWI (p < 0.01), poor blood flow on DSA (p < 0.01), the presence of DPM (p = 0.05) and a low rCBV ratio on PWI (p < 0.01) were related to END occurrence. The multivariate analysis showed that the presence of a low rCBV ratio on PWI was independently significant as a correlate of END (OR, 5.64; 95% CI, 1.68-18.90; p < 0.01). Conclusion: This study shows that the rCBV ratio on PWI may be a useful tool to reveal the status of blood flow after AIS. Moreover, the extent of collateral flow may be an important parameter that subtly influences the fate of DPM in AIS.
    Clinical Neurology and Neurosurgery 07/2014; 122C:54-58. DOI:10.1016/j.clineuro.2014.04.001 · 1.25 Impact Factor
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    ABSTRACT: Background: The safety and efficacy of intravenous tissue plasminogen activator (IV-TPA) in the 3- to 4.5-hour window were largely driven from Western populations, but have not been systematically explored in Korean population. Methods: We compared outcomes of acute ischemic stroke patients treated in the 3- to 4.5-hour window versus those in the 0- to 3-hour window, using a prospective multicenter registry database. Safety outcomes included symptomatic intracranial hemorrhage (SICH) and 3-month mortality and efficacy outcomes were the proportions of modified Rankin Scale (mRS) 0-1 and mRS 0-2 and the overall mRS distribution at 3 months. Results: Among 723 patients consecutively treated with IV-TPA alone, 616 were treated within 3 hours and 107 treated between 3 and 4.5 hours. The median onset-to-treatment time was 115 minutes for 0- to 3-hour group and 217 minutes for 3- to 4.5-hour group. The SICH rate was higher in the 3- to 4.5-hour group than in the 0- to 3-hour group (4.7% vs. 3.1%), but the difference was not significant (adjusted odds ratio [OR] [95% confidence interval {CI}], .81 [.20-3.35]). There were no significant differences between the 3- to 4.5-hour and 0- to 3-hour groups in the 3-month mortality (19.6% vs. 12.0%), mRS 0-1 (39.3% vs. 42.9%), mRS 0-2 (48.6% vs. 55.7%), and the overall mRS distribution (adjusted proportional OR [95% CI], .94 [.63-1.41]) after adjusting for covariates. Conclusions: IV-TPA treatment can be safely and efficaciously administered to eligible Korean patients up to the extended time window of 4.5 hours. However, efforts to expedite the treatment should not be neglected.
    Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 06/2014; 23(7). DOI:10.1016/j.jstrokecerebrovasdis.2014.04.027 · 1.99 Impact Factor
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    ABSTRACT: Objective The T2*-weighted gradient echo image susceptibility vessel sign (GRE SVS) is a well-known indicator of intraluminal thrombi in acute cerebral infarction. The purpose of this study was to evaluate the relationships between thrombus size on GRE SVS and recanalization after intravenous administration of tissue plasminogen activator (IV-tPA). Materials and Methods Fifty five patients with GRE SVSs on the M1 were enrolled. Examination of magnetic resonance image (MRI), including diffusion weighted imaging and MR angiography, was performed within 20 minutes of admission. Thrombus size on GRE was calculated using the Picture Archiving and Communication System upon initial MRI. Recanalization was assessed with follow-up MRI or transfemoral cerebral angiography within 24 hours of treatment. Results The patient group consisted of 37 males and 18 females with an average age of 63.74 ± 10.28 years (range: 43 - 77 years). The median NIHSS score was 13. Fifteen of these patients achieved recanalization (27.3%). The average thrombus cross-sectional area in the recanalization group was 38.54 ± 20.27 mm2, and the corresponding size of the non-recanalization group was 53.38 ± 24.77 mm2 (p = 0.043). In the receiver operator characteristic curve for thrombus cross-sectional area in relation to recanalization, the cut-off point was 47.28 mm2. The sensitivity at this cut-off point was 73.3%, the specificity was 60%, and the area under the curve was 0.687. Conclusion Thrombus size on GRE is a simple diagnostic tool that can be easily measured, and thrombus size on GRE SVS was found to be associated with recanalization after IV-tPA.
    06/2014; 16(2):85-92. DOI:10.7461/jcen.2014.16.2.85
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    ABSTRACT: Symptomatic steno-occlusion (SYSO) in acute ischemic stroke has a significant impact on treatment options and prognosis. However, the prevalence, distribution, clinical characteristics, and outcome of SYSO are not well known. We retrospectively identified 3,451 patients hospitalized because of ischemic stroke within 24 hours of symptom onset at 9 stroke centers in South Korea. Patients who did not undergo magnetic resonance imaging were excluded. SYSO was defined as stenosis or occlusion of cerebral arteries with relevant ischemic lesions in the corresponding arterial territory. The number, location, and severity of SYSOs and their effects on functional outcome were analyzed. In total, 1,929 of 3,057 subjects (63.1%) had SYSO. The most frequently affected vessels were the middle cerebral artery (34.6%), extracranial internal carotid artery (14%), vertebral artery (12.4%), and basilar artery (8.7%). SYSO predicted poor outcome on the modified Rankin Scale 3-6 (odds ratio, 1.77; 95% confidence interval, 1.46-2.15) with adjustments. Involvement of 2 or more vessels was observed in 30.6% of patients with SYSO and independently increased the risk of poor outcome (odds ratio, 2.76; 95% confidence interval, 2.12-3.59). The severity of SYSO was associated with outcome and showed a significant dose-response trend (P<0.001). The effect of SYSO on outcome did not significantly differ by individual arterial location (P for contrast=0.21). Approximately 60% of patients with acute ischemic stroke had SYSO, and the severity and number were inversely correlated with outcome. The results suggest that SYSO could predict stroke outcome.
    01/2014; 16(1):36-43. DOI:10.5853/jos.2014.16.1.36
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    ABSTRACT: Objective In this study, we evaluated the relationship between the rCBV (regional cerebral blood flow volume) ratio on perfusion-weighted imaging (PWI) and the extent of collateral flow on conventional angiography. Methods We recruited 98 patients with AIS (within 24 h after ischemic events). All the patients were evaluated by MRI, including PWI and diffusion-weighted imaging (DWI), and underwent digital subtraction angiography (DSA) of the brain. We hypothesized that the rCBV ratio on PWI could reveal the extent of the blood flow and predict early neurological deterioration (END) within 7 days after AIS. Results The rCBV ratio on PWI was significantly correlated with its extent on DSA (p < 0.01). During the observation period, 24 patients (24.5%) experienced END. The univariate analysis revealed that severe neurological deficit at admission (p < 0.01), the volume of the ischemic lesion on DWI (p < 0.01), poor blood flow on DSA (p < 0.01), the presence of DPM (p = 0.05) and a low rCBV ratio on PWI (p < 0.01) were related to END occurrence. The multivariate analysis showed that the presence of a low rCBV ratio on PWI was independently significant as a correlate of END (OR, 5.64; 95% CI, 1.68–18.90; p < 0.01). Conclusion This study shows that the rCBV ratio on PWI may be a useful tool to reveal the status of blood flow after AIS. Moreover, the extent of collateral flow may be an important parameter that subtly influences the fate of DPM in AIS.
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    ABSTRACT: Background This study aimed to estimate the population-attributable risks (PARs) of 9 major risk factors for stroke in Korea through a case–control study and to test the feasibility and validity of internet-based control recruitment. Methods From April 2008 to September 2009, controls were enrolled via internet after providing consent for participation through a web-based survey. The cases included patients who were admitted to the participating centers due to acute stroke or transient ischemic attack within 7 days of onset during the study period. Each control was age- and sex-matched with 2 cases. Adjusted odd ratios, age-standardized prevalence, and PARs were estimated for the 9 major risk factors using the prevalence of risk factors in the control group and the age and sex characteristics from Korea's national census data. Results In total, 1041 controls were matched to 2082 stroke cases. Because of a shortage of elderly controls in the internet-based recruitment, 248 controls were recruited off-line. The PARs were 23.44%, 10.95%, 51.32%, and 6.35% for hypertension, diabetes, smoking, and stroke history, respectively. Hypercholesterolemia, atrial fibrillation, obesity, coronary heart disease, and a family history of stroke were not associated with stroke. Comparison with education and religion of the control group with that mentioned in the national census data showed a notable difference. Conclusions The study results imply that internet-based control recruitment for a case–control study requires careful selection of risk factors with high self-awareness and effective strategies to facilitate the recruitment of elderly participants.
  • Jae-Hyung Choi · Jae-Kwan Cha · Jae-Taeck Huh
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    ABSTRACT: Systemic atherosclerosis is involved in ischemic damages and cardioembolism after atrial fibrillation (AF)-related ischemic stroke (IS). Platelet activation is a critical factor in systemic atherosclerosis; however, there is little information regarding the role of platelet activation on the outcome of AF-related IS. We investigated the relationship between adenosine diphosphate (ADP)-induced platelet aggregation and the long-term outcomes of AF-related IS. We studied 249 patients who were exclusively treated with anticoagulation therapy after they had experienced AF-related IS. We evaluated their platelet function 5 days after admission to the hospital by using an optic platelet aggregometer test. We also assessed the prognoses of patients 90 days after the AF-related IS. Our results showed that ADP-induced platelet aggregation was positively correlated with CHA2DS2-VASc scores (r = .285, P < .01). Totally, 107 (43.0%) patients had a poor outcome at 90 days after IS. Univariate analysis showed that the following factors significantly contribute to a poor outcome: older age (odds ratio [OR] = 1.07, confidence interval [CI] 1.04-1.10, P < .01), a history of stroke (OR = 3.24, CI 1.61-6.53, P < .01), high scores on the National Institutes of Health Stroke Scale (NIHSS; OR = 1.25, CI 1.18-1.32, P < .01), increased white blood cell counts (OR = 1.12, CI 1.02-1.24, P < .01), high CHA2DS2-VASc scores (≥5, OR = 7.31, CI 3.36-15.93, P = .025), and the highest tertile of ADP-induced platelet aggregation (≥72%, OR = 3.17, CI 1.67-5.99, P < .01). Of these factors, high NIHSS scores (OR = 1.27, CI 1.20-1.36, P < .01), high CHA2DS2-VASc scores (OR = 4.69, CI 1.21-18.14, P = .03), and the highest tertile of ADP-induced platelet aggregation (OR = 2.49, CI 1.17-5.27, P = .02) were independently associated with a poor outcome at 90 days after IS. Therefore, our results suggest that platelet activation might affect the outcome of AF-related IS.
    Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 11/2013; 23(3). DOI:10.1016/j.jstrokecerebrovasdis.2013.10.011 · 1.99 Impact Factor
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    ABSTRACT: Although ethnic or cultural differences affect prevalence of cardiovascular risk factors, limited information is available about the age- and gender-stratified prevalence of the risk factors in Asian stroke population. We assessed gender- and age-stratified prevalences of major risk factors in Korean stroke patients, and assumed that the gender differences are attenuated by adjustment with lifestyle factors. Using the nationwide hospital-based stroke registry, we identified 9417 ischemic stroke patients admitted between April 2008 and January 2011. Prevalence of hypertension, diabetes, hyperlipidemia, atrial fibrillation, prior stroke, and coronary heart disease was assessed in both genders by age groups. We analyzed gender differences of the prevalence among the age groups by calculating prevalence ratio, and further explored the influence of lifestyle factors on the gender difference in multivariable analyses. Hypertension and hyperlipidemia were more common in men until middle age, but after that more common in women, whereas diabetes was more common in women after 65 years of age. Atrial fibrillation increased steadily with age in both genders but was more common in women through all age groups. Prior stroke and coronary heart disease showed inconsistent gender differences. Gender differences in hypertension and diabetes among the age groups were attenuated by adjustment with accompanying risk factors including lifestyle factors. Korean women with stroke had more hypertension and hyperlipidemia after middle age, more diabetes after 65 years, and more atrial fibrillation throughout all ages. Strategies to control risk factors in women at risk for stroke are eagerly needed.
    International Journal of Stroke 10/2013; 9(6). DOI:10.1111/ijs.12146 · 4.03 Impact Factor
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    ABSTRACT: The drip and ship paradigm for stroke patients enhances the rate of using intravenous tissue plasminogen activator (IVT) in community hospitals. The safety and outcomes of patients treated with IVT for acute ischemic stroke (AIS) under the drip and ship paradigm were compared with patients directly treated at a comprehensive stroke center in the Busan metropolitan area of Korea. This was a retrospective study of patients with AIS treated with IVT between January 2009 and January 2012. Information on patients' baseline characteristics, neuroimaging, symptomatic intracerebral hemorrhage (sICH), and outcome 90 days after using IVT was obtained from our stroke registry. We surveyed stroke neurologists regarding their pattern of post-thrombolysis care. During the observation periods, we selected 317 patients using IVT. Among these, 239 patients received IVT at our stroke center, and 78 were treated at 21 community hospitals under the drip and ship paradigm. Initial neurologic deficits and the size of ischemic lesions on magnetic resonance imaging were much more severe in patients treated with IVT under the drip and ship paradigm compared with patients treated at our comprehensive stroke center. The prevalence of a poor outcome (modified Rankin Scale score 3-6) 90 days after IVT was much higher in patients treated with the drip and ship paradigm than in those treated at our comprehensive stroke center. Regarding the occurrence of sICH, there was no significant difference between the 2 groups. The clinical characteristics and outcomes after using IVT under the drip and ship paradigm may differ greatly among stroke care systems.
    Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 10/2013; 23(1). DOI:10.1016/j.jstrokecerebrovasdis.2013.07.032 · 1.99 Impact Factor

Publication Stats

188 Citations
105.97 Total Impact Points

Institutions

  • 2002–2015
    • Dong-A University
      • Department of Neurology
      Tsau-liang-hai, Busan, South Korea
  • 2003–2010
    • Dong Thap University
      Phong Thanh, Đồng Tháp, Vietnam