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

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

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

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

Prevalence of Mutations in Mendelian Stroke Genes in Early Onset Stroke Patients.

OBJECTIVE: Heritability of stroke is assumed not to be low, especially in the young stroke population. However, most genetic studies have been performed in highly selected patients with typical clinical or neuroimaging characteristics. We investigated the prevalence of 15 Mendelian stroke genes and explored the relationships between variants and the clinical and neuroimaging characteristics in a large, unselected, young stroke population. METHODS: We enrolled patients aged ≤55 years with stroke or transient ischemic attack from a prospective, nationwide, multicenter stroke registry. We identified clinically relevant genetic variants (CRGVs) in 15 Mendelian stroke genes (GLA, NOTCH3, HTRA1, RNF213, ACVRL1, ENG, CBS, TREX1, ABCC6, COL4A1, FBN1, NF1, COL3A1, MT-TL1, and APP) using a customized, targeted next generation sequencing panel. RESULTS: Among 1,033 patients, 131 (12.7%) had 28 CRGVs, most frequently in RNF213 (n = 59), followed by ABCC6 (n = 53) and NOTCH3 (n = 15). The frequency of CRGVs differed by ischemic stroke subtypes (p < 0.01): the highest in other determined etiology (20.1%), followed by large artery atherosclerosis (13.6%). It also differed between patients aged ≤35 years and those aged 51 to 55 years (17.1% vs 9.3%, p = 0.02). Only 27.1% and 26.7% of patients with RNF213 and NOTCH3 variants had typical neuroimaging features of the corresponding disorders, respectively. Variants of uncertain significance (VUSs) were found in 15.4% patients. INTERPRETATION: CRGVs in 15 Mendelian stroke genes may not be uncommon in the young stroke population. The majority of patients with CRGVs did not have typical features of the corresponding monogenic disorders. Clinical implications of having CRGVs or VUSs should be explored. ANN NEUROL 2023;93:768-782.

Frequency, management, and outcomes of early neurologic deterioration due to stroke progression or recurrence.

OBJECTIVE: The frequency, management, and outcomes of early neurologic deterioration (END) after ischemic stroke specifically due to stroke progression or stroke recurrence have not been well delineated. MATERIALS AND METHODS: In a multicenter, nationwide registry, data on END due to stroke progression or recurrence confirmed by imaging were collected prospectively between January 2019 and July 2020. Patient characteristics, management strategies, and clinical outcomes were analyzed. RESULTS: Among 14,828 consecutive ischemic stroke patients, 1717 (11.6%) experienced END, including 1221 (8.2%) with END due to stroke progression (SP) or stroke recurrence (SR). Active management after END was implemented in 64.2% of patients. Active management strategies included volume expansion (29.2%), change in antithrombotic regimen (26.1%), induced hypertension (8.6%), rescue reperfusion therapy (6.8%), intracranial pressure lowering with hyperosmolar agents (1.5%), bypass surgery (0.6%), and hypothermia (0.1%). Active management strategies that varied with patient features included volume expansion and induced hypertension, used more often in large artery atherosclerosis and small vessel occlusion, and rescue endovascular thrombectomy, more common in other (dissection), cardioembolism, and large artery atherosclerosis. Active management was associated with higher rates of freedom from disability (modified Rankin Scale, mRS, 0-1; 24.3% vs. 16.6%) and functional independence (mRS, 0-2; 41.6% vs. 27.7%) at 3 months. CONCLUSION: END specifically due to stroke progression or recurrence occurs in 1 in 12 acute ischemic stroke patients. In this observational study, active management, undertaken in two-thirds of patients, was most often hemodynamic or antithrombotic and was associated with improved functional outcomes.

Stroke of Other Determined Etiology: Results From the Nationwide Multicenter Stroke Registry.

BACKGROUND: Stroke of other determined etiology (OE) includes patients with an uncommon cause of stroke. We described the general characteristics, management, and outcomes of stroke in OE and its subgroups. METHODS: This study is a retrospective analysis of a prospective, multicenter, nationwide registry, the Clinical Research Center for Stroke-Korea-National Institutes of Health registry. We classified OE strokes into 10 subgroups according to the literature and their properties. Each OE subgroup was compared according to clinical characteristics, sex, age strata, lesion locations, and management. Moreover, 1-year composites of stroke and all-cause mortality were investigated according to the OE subgroups. RESULTS: In total, 2119 patients with ischemic stroke with OE types (mean age, 55.6±16.2 years; male, 58%) were analyzed. In the Clinical Research Center for Stroke-Korea-National Institutes of Health registry, patients with OE accounted for 2.8% of all patients with stroke. The most common subtypes were arterial dissection (39.1%), cancer-related coagulopathy (17.3%), and intrinsic diseases of the arterial wall (16.7%). Overall, strokes of OE were more common in men than in women (58% versus 42%). Arterial dissection, intrinsic diseases of the arterial wall and stroke associated with migraine and drugs were more likely to occur at a young age, while disorders of platelets and the hemostatic system, cancer-related coagulopathy, infectious diseases, and hypoperfusion syndromes were more frequent at an old age. The composite of stroke and all-cause mortality within 1 year most frequently occurred in cancer-related coagulopathy, with an event rate of 71.8%, but least frequently occurred in stroke associated with migraine and drugs and arterial dissection, with event rates of 0% and 7.2%, respectively. CONCLUSIONS: This study presents the different characteristics, demographic findings, lesion locations, and outcomes of OE and its subtypes. It is characterized by a high proportion of arterial dissection, high mortality risk in cancer-related coagulopathy and an increasing annual frequency of cancer-related coagulopathy in patients with stroke of OE.

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.

In-Hospital and Post-Discharge Recovery after Acute Ischemic Stroke: a Nationwide Multicenter Stroke Registry-base Study.

BACKGROUND: Using data from a large national stroke registry, we aimed to investigate the incidence and determinants of in-hospital and post-discharge recovery after acute ischemic stroke and the independence of their occurrence. METHODS: In-hospital recovery was defined as an improvement of 4 points or > 40% in the National Institutes of Health Stroke Scale (NIHSS) score from admission to discharge. Post-discharge recovery was defined as any improvement in the modified Rankin Scale (mRS) score from discharge to 3 months after stroke onset. Two analytic methods (multivariate and multivariable logistic regression) were applied to compare the effects of 18 known determinants of 3-month outcome and to verify whether in-hospital and post-discharge recovery occur independently. RESULTS: During 54 months, 11,088 patients with acute ischemic stroke meeting the eligibility criteria were identified. In-hospital and post-discharge recovery occurred in 36% and 33% of patients, respectively. Multivariate logistic regression with an equality test for odds ratios showed that 7 determinants (age, onset-to-admission time, NIHSS score at admission, blood glucose at admission, systolic blood pressure, smoking, recanalization therapy) had a differential effect on in-hospital and post-discharge recovery in the way of the opposite direction or of the same direction with different degree (all P values < 0.05). Both in-hospital and post-discharge recovery occurred in 12% of the study population and neither of them in 43%. The incidence of post-discharge recovery in those with in-hospital recovery was similar to that in those without (33.8% vs. 32.7%, respectively), but multivariable analysis showed that these 2 types of recovery occurred independently. CONCLUSION: Our findings suggest that, in patients with acute ischemic stroke, in-hospital and post-discharge recovery may occur independently and largely in response to different factors.

Executive Summary of Stroke Statistics in Korea 2018: A Report from the Epidemiology Research Council of the Korean Stroke Society.

Despite the great socioeconomic burden of stroke, there have been few reports of stroke statistics in Korea. In this scenario, the Epidemiologic Research Council of the Korean Stroke Society launched the "Stroke Statistics in Korea" project, aimed at writing a contemporary, comprehensive, and representative report on stroke epidemiology in Korea. This report contains general statistics of stroke, prevalence of behavioral and vascular risk factors, stroke characteristics, pre-hospital system of care, hospital management, quality of stroke care, and outcomes. In this report, we analyzed the most up-to-date and nationally representative databases, rather than performing a systematic review of existing evidence. In summary, one in 40 adults are patients with stroke and 232 subjects per 100,000 experience a stroke event every year. Among the 100 patients with stroke in 2014, 76 had ischemic stroke, 15 had intracerebral hemorrhage, and nine had subarachnoid hemorrhage. Stroke mortality is gradually declining, but it remains as high as 30 deaths per 100,000 individuals, with regional disparities. As for stroke risk factors, the prevalence of smoking is decreasing in men but not in women, and the prevalence of alcohol drinking is increasing in women but not in men. Population-attributable risk factors vary with age. Smoking plays a role in young-aged individuals, hypertension and diabetes in middle-aged individuals, and atrial fibrillation in the elderly. About four out of 10 hospitalized patients with stroke are visiting an emergency room within 3 hours of symptom onset, and only half use an ambulance. Regarding acute management, the proportion of patients with ischemic stroke receiving intravenous thrombolysis and endovascular treatment was 10.7% and 3.6%, respectively. Decompressive surgery was performed in 1.4% of patients with ischemic stroke and in 28.1% of those with intracerebral hemorrhage. The cumulative incidence of bleeding and fracture at 1 year after stroke was 8.9% and 4.7%, respectively. The direct costs of stroke were about ₩1.68 trillion (KRW), of which ₩1.11 trillion were for ischemic stroke and ₩540 billion for hemorrhagic stroke. The great burden of stroke in Korea can be reduced through more concentrated efforts to control major attributable risk factors for age and sex, reorganize emergency medical service systems to give patients with stroke more opportunities for reperfusion therapy, disseminate stroke unit care, and reduce regional disparities. We hope that this report can contribute to achieving these tasks.

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.

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.

Internet-based control recruitment for a case-control study of major risk factors for stroke in Korea: lessons from the experience.

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.

N-methylated beta-carbolines protect PC12 cells from cytotoxic effect of MPP+ by attenuation of mitochondrial membrane permeability change.

Opening of the mitochondrial permeability transition pore has been recognized to be involved in cell death. The present study investigated the effect of beta-carbolines (harmaline and harmalol) on the MPP(+)-induced change in the mitochondrial membrane permeability and cell death in differentiated PC12 cells. beta-Carbolines and antioxidants (superoxide dismutase, catalase, ascorbate or rutin) prevented the loss of cell viability in PC12 cells treated with 250 microM MPP(+), while the effects of N-acetylcysteine and dithiothreitol were not observed. beta-Carbolines reduced the condensation and fragmentation of nuclei caused by MPP(+) in PC12 cells. beta-Carbolines alone did not exhibit a significant cytotoxic effect on PC12 cells. beta-Carbolines (50 microM) inhibited the decrease in mitochondrial transmembrane potential, cytochrome c release, activation of caspase-3, formation of reactive oxygen species (ROS) and depletion of GSH caused by MPP(+) in PC12 cells. beta-Carbolines reduced the hydrogen peroxide- or SIN-1-induced cell death in PC12 cells. The results suggest that beta-carbolines may attenuate the MPP(+)-induced viability loss in PC12 cells by inhibition of change in the mitochondrial membrane permeability and by antioxidant effect.