Secular Trends in Outcomes and Impact of Novel Oral Anticoagulants in Atrial Fibrillation-Related Acute Ischemic Stroke

BACKGROUND

Novel oral anticoagulants (NOACs) are currently recommended for the secondary prevention of stroke in patients with acute ischemic stroke (AIS) accompanied by atrial fibrillation (AF). However, the impact of NOACs on clinical outcomes in real-world practice remains ambiguous. This study analyzes the trend of clinical events in patients with AF-related AIS and determines how much the introduction of NOACs has mediated this trend.

METHODS

We identified patients with AIS and AF between January 2011 and December 2019 using a multicenter stroke registry. Annual rates of NOAC prescriptions and clinical events within 1 year were evaluated. The primary outcome was a composite of recurrent stroke, myocardial infarction, and all-cause mortality. To assess the mediation effect of NOACs on the relationship between the calendar year and these outcomes, we used natural effect models and conducted exposure-mediator, exposure-outcome, and mediator-outcome analyses using multivariable regression models or accelerated failure time models, adjusting for potential confounders.

RESULTS

Among the 12 977 patients with AF-related AIS, 12 500 (average age: 74.4 years; 51.3% male) were analyzed after excluding cases of valvular AF. Between 2011 and 2019, there was a significant decrease in the 1-year incidence of the primary composite outcome from 28.3% to 21.7%, while the NOAC prescription rate increased from 0% to 75.6%. A 1-year increase in the calendar year was independently associated with delayed occurrence of the primary outcome (adjusted time ratio, 1.10 [95% CI, 1.07-1.14]) and increased NOAC prescription (adjusted odds ratio, 2.20 [95% CI, 2.14-2.27]). Increased NOAC prescription was associated with delayed occurrence of the primary outcome (adjusted time ratio, 3.82 [95% CI, 3.17 to 4.61]). Upon controlling for NOAC prescription (mediator), the calendar year no longer influenced the primary outcome (adjusted time ratio, 0.97 [95% CI, 0.94-1.00]). This suggests that NOAC prescription mediates the association between the calendar year and the primary outcome.

CONCLUSIONS

Our study highlights a temporal reduction in major clinical events or death in Korean patients with AF-related AIS, mediated by increased NOAC prescription, emphasizing NOAC use in this population.

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.

Comparison of Hospital Performance in Acute Ischemic Stroke Based on Mortality and Functional Outcome in South Korea

BACKGROUND

Recent evidence suggests a correlation between modified Rankin Scale-based measures, an outcome measure commonly used in acute stroke trials, and mortality-based measures used by health agencies in the evaluation of hospital performance. We aimed to examine whether the 2 types of measures are interchangeable in relation to evaluation of hospital performance in acute ischemic stroke.

METHODS

Five outcome measures, unfavorable functional outcome (3-month modified Rankin Scale score ≥2), death or dependency (3-month modified Rankin Scale score ≥3), 1-month mortality, 3-month mortality, and 1-year mortality, were collected for 8292 individuals who were hospitalized for acute ischemic stroke between January 2014 and May 2015 in 14 hospitals participating in the Clinical Research Collaboration for Stroke in Korea - National Institute of Health registry. Hierarchical regression models were used to calculate per-hospital risk-adjusted outcome rates for each measure. Hospitals were ranked and grouped based on the risk-adjusted outcome rates, and the correlations between the modified Rankin Scale-based and mortality-based ranking and their intermeasure reliability in categorizing hospital performance were analyzed.

RESULTS

The comparison between the ranking based on the unfavorable functional outcome and that based on 1-year mortality resulted in a Spearman correlation coefficient of -0.29 and Kendall rank coefficient of -0.23, and the comparison of grouping based on these 2 types of ranks resulted in a weighted kappa of 0.123 for the grouping in the top 33%/middle 33%/bottom 33% and 0.25 for the grouping in the top 20%/middle 60%/bottom 20%, respectively. No significant correlation or similarity in grouping capacities were found between the rankings based on the functional outcome measures and those based on the mortality measures.

CONCLUSIONS

This study shows that regardless of clinical correlation at an individual patient level, functional outcome-based measures and mortality-based measures are not interchangeable in the evaluation of hospital performance in acute ischemic stroke.

Abstract WMP97: Symptomatic Steno-occlusion Of Major Cerebral Arteries And Stroke Recurrence In Acute Ischemic Stroke Patients With Atrial Fibrillation

Introduction: There is lack of knowledge on whether symptomatic steno-occlusion (SYSO), common in acute ischemic stroke (AIS) patients with atrial fibrillation (AF), could increase the long-term risk of stroke recurrence in these patients.

Methods: From a prospective cohort of patients with AIS and AF enrolled in 14 centers between Oct 2017 and Dec 2018, we identified patients who underwent MR angiography during hospitalization and completed 3-year follow-up including death during follow-up. SYSO was defined as (1) ≥ 50% stenosis or occlusion of cerebral arteries relevant to acute infarction or (2) any residual stenosis after endovascular treatment. Using cause-specific hazard models with non-stroke death as a competing risk, the risk of any recurrent stroke and recurrent ischemic stroke was estimated according to SYSO, respectively.

Results: A total of 889 patients (mean age, 74.4 years; men, 54.6 %; median NIHSS, 6) were analyzed for this study. During the median 1096 days of follow-up, 152 any recurrent strokes, 142 recurrent ischemic strokes, and 208 deaths were observed. Patients with SYSO, compared to those without, were more likely to be older, be female, have hypertension, diabetes and history of stroke/TIA, and be on antiplatelets at discharge and were less likely to be on anticoagulants at discharge ( p <.05). The cumulative incidence of recurrent stroke in patients with and without SYSO was 25.2% and 8.3% at 1 month, 33.1% and 9.9% at 1 year, and 41.8% and 13.1% at 3 years, respectively ( p <.001). With adjusting age, sex, hypertension, diabetes, history of stroke/TIA, discharge antiplatelets, and discharge anticoagulants, SYSO increased the risk of any stroke recurrence (adjusted hazard ratio [95% confidence interval]; 3.02 [2.18-4.20]; p <.001) and ischemic stroke recurrence (3.20 [2.28-4.51]; p <.001).

Conclusions: SYSO in AIS patients with AF substantially increased the risk of recurrent stroke by a 3-fold or more. Accordingly, SYSO should be considered in stratifying the risk of recurrence in AIS patients with AF.

Abstract 44: Impact Of Novel Oral Anticoagulant Use On Secular Trend Of Vascular Events Or Death After Atrial Fibrillation-related Acute Ischemic Stroke

Introduction: Now novel oral anticoagulants (NOAC) are strongly recommended for secondary stroke prevention in patients with atrial fibrillation (AF). However, it remains unclear to what extent the introduction of NOACs improved clinical outcomes in real-world practice.

Methods: Using a nationwide prospective multi-center stroke registry database, we identified consecutive AIS patients with AF enrolled between Jan 2011 and Dec 2019, and analyzed one-year clinical events and NOAC prescription at discharge. The primary outcome was the composite of stroke, myocardial infarction, and all-cause death. To assess the mediation effect of NOAC on the outcomes, we performed natural effect models according to the calendar year. The exposure-mediator analysis, exposure-outcome analysis, and mediator-outcome analysis were performed using multivariate regression analysis according to the characteristics of the variables.

Results: We analyzed 12,500 patients (mean age, 74.4 years; 51.3% male; median NIHSS at presentation, 8). From 2011 to 2019, the cumulative one-year incidence of the primary composite outcome (28.3% to 22.1%), all-cause mortality (23.8% to 17.9%), and stroke recurrence (8.3% to 5.1%) significantly decreased, while the NOAC prescription rate at discharge increased (0% to 75.6%). One-year increase in the calendar year was independently associated with a delayed occurrence of primary composite outcomes (Step 1: adjusted Time Ratio (aTR), 1.10; 95% confidence interval, 1.07-1.14) and with an increased NOAC prescription rate (Step 2: adjusted odds ratio, 2.20; 2.14-2.27). Increase in the NOAC prescription rate was significantly associated with the delayed occurrence of primary composite outcome (Step 3: aTR, 3.80; 3.15-4.58). However, after controlling for the NOAC prescription rate (mediator), the calendar year was no longer associated with the primary composite outcomes. (Step 4: aTR, 0.78; 95% CI 0.60-1.03). Thus, our results indicate full mediation of NOAC prescription in the association between the calendar year and primary composite outcomes.

Conclusion: The reduced risk of major vascular events or death over time in AIS patients with AF was fully mediated by the increase in NOAC use.

Covert Brain Infarction as a Risk Factor for Stroke Recurrence in Patients With Atrial Fibrillation

BACKGROUND

We aimed to evaluate covert brain infarction (CBI), frequently encountered during the diagnostic work-up of acute ischemic stroke, as a risk factor for stroke recurrence in patients with atrial fibrillation (AF).

METHODS

For this prospective cohort study, from patients with acute ischemic stroke hospitalized at 14 centers between 2017 and 2019, we enrolled AF patients without history of stroke or transient ischemic attack and divided them into the CBI (+) and CBI (-) groups. The 2 groups were compared regarding the 1-year cumulative incidence of recurrent ischemic stroke and all-cause mortality using the Fine and Gray subdistribution hazard model with nonstroke death as a competing risk and the Cox frailty model, respectively. Each CBI lesion was also categorized into either embolic-appearing (EA) or non-EA pattern CBI. Adjusted hazard ratios and 95% CIs of any CBI, EA pattern CBI only, non-EA pattern CBI only, and both CBIs were estimated.

RESULTS

Among 1383 first-ever stroke patients with AF, 578 patients (41.8%) had CBI. Of these 578 with CBI, EA pattern CBI only, non-EA pattern CBI only, and both CBIs were 61.8% (n=357), 21.8% (n=126), and 16.4% (n=95), respectively. The estimated 1-year cumulative incidence of recurrent ischemic stroke was 5.2% and 1.9% in the CBI (+) and CBI (-) groups, respectively (P=0.001 by Gray test). CBI increased the risk of recurrent ischemic stroke (adjusted hazard ratio [95% CI], 2.91 [1.44-5.88]) but did not the risk of all-cause mortality (1.32 [0.97-1.80]). The EA pattern CBI only and both CBIs elevated the risk of recurrent ischemic stroke (2.76 [1.32-5.77] and 5.39 [2.25-12.91], respectively), while the non-EA pattern only did not (1.44 [0.40-5.16]).

CONCLUSIONS

Our study suggests that AF patients with CBI might have increased risk of recurrent stroke. CBI could be considered when estimating the stroke risk in patients with AF.

Risk of Subsequent Events in Patients With Minor Ischemic Stroke or High-Risk Transient Ischemic Attack

This study aimed to present the prognosis after minor acute ischemic stroke (AIS) or transient ischemic attack (TIA), using a definition of subsequent stroke in accordance with recent clinical trials. In total, 9,506 patients with minor AIS (National Institutes of Health Stroke Scale ≤ 5) or high-risk TIA (acute lesions or ≥ 50% cerebral artery steno-occlusion) admitted between November 2010 and October 2013 were included. The primary outcome was the composite of stroke (progression of initial event or a subsequent event) and all-cause mortality. The cumulative incidence of stroke or death was 11.2% at 1 month, 13.3% at 3 months and 16.7% at 1 year. Incidence rate of stroke or death in the first month was 12.5 per 100 person-months: highest in patients with large artery atherosclerosis (17.0). The risk of subsequent events shortly after a minor AIS or high-risk TIA was substantial, particularly in patients with large artery atherosclerosis.

Effectiveness and safety of EVT in patients with acute LVO and low NIHSS

Background and purpose

There is much uncertainty in endovascular treatment (EVT) decisions in patients with acute large vessel occlusion (LVO) and mild neurological deficits.

Methods

From a prospective, nationwide stroke registry, all patients with LVO and baseline NIHSS &lt;6 presenting within 24 h from the time last known well (LKW) were included. Early neurological deterioration (END) developed before EVT was prospectively collected as an increasing total NIHSS score ≥2 or any worsening of the NIHSS consciousness or motor subscores during hospitalization not related to EVT. Significant hemorrhage was defined as PH2 hemorrhagic transformation or hemorrhage at a remote site. The modified Rankin Scale (mRS) was prospectively collected at 3 months.

Results

Among 1,083 patients, 149 (14%) patients received EVT after a median of 5.9 [3.6–12.3] h after LKW. In propensity score-matched analyses, EVT was not associated with mRS 0-1 (matched OR 0.99 [0.63–1.54]) but increased the risk of a significant hemorrhage (matched OR, 4.51 [1.59–12.80]). Extraneous END occurred in 207 (19%) patients after a median of 24.5 h [IQR, 13.5–41.9 h] after LKW (incidence rate, 1.41 [95% CI, 1.23–1.62] per 100 person-hours). END unrelated to EVT showed a tendency to modify the effectiveness of EVT (P-for-interaction, 0.08), which decreased the odds of having mRS 0–1 in mild LVO patients without END (adjusted OR, 0.63 [0.40–0.99]).

Conclusions

The use of EVT in patients with acute LVO and low NIHSS scores may require the assessment of individual risks of early deterioration, hemorrhagic complications and expected benefit.

Facemask ventilation and vocal cord angle following neuromuscular blockade: a prospective observational study. Anaesthesia 2022;77:1010-1017. [PMID: 35727620 DOI: 10.1111/anae.15786]

Numerous studies support the idea that neuromuscular blockade facilitates facemask ventilation after induction of anaesthesia. Although improved airway patency or pulmonary compliance and a resolution of laryngospasm have been suggested as possible causes, the exact mechanism remains unclear. We aimed to assess whether neuromuscular blockade improves facemask ventilation and to clarify whether this phenomenon is associated with the vocal cord angle. This prospective observational study included patients aged between 20 and 65 years scheduled for elective surgery under general anaesthesia. After induction of anaesthesia, patients' lungs were ventilated with pressure-controlled ventilation using a facemask. During facemask ventilation, a flexible bronchoscope was inserted through a self-sealing diaphragm at the elbow connector attached to the facemask and breathing circuit and positioned to allow a continuous view of the vocal cords. The mean tidal volume and vocal cord angle were measured before and after administration of neuromuscular blocking drugs. Of 108 patients, 100 completed the study. Mean (SD) tidal volume ((11.0 (3.9) ml.kg^-1 vs. 13.6 (2.6) ml.kg^-1 ; p < 0.001) and mean (SD) vocal cord angle (17° (10°) vs. 26° (5°); p < 0.001) increased significantly after neuromuscular blockade. The proportional increase in mean tidal volume after neuromuscular blockade was positively correlated with vocal cord angle (Spearman's ρ = 0.803; p < 0.001). In conclusion, neuromuscular blockade facilitated facemask ventilation, and the improvement was correlated with further opening of the vocal cords.

One-Year Blood Pressure Trajectory After Acute Ischemic Stroke

Background Although the effect of blood pressure on poststroke outcome is well recognized, the long-term trajectory of blood pressure after acute ischemic stroke and its influence on outcomes have not been studied well. Methods and Results We analyzed systolic blood pressure (SBP) measurements in 5514 patients with acute ischemic stroke at ≥2 of 7 prespecified time points during the first year after stroke among those enrolled in a multicenter prospective registry. Longitudinal SBPs were categorized using a group-based trajectory model. The primary outcome was a composite of stroke recurrence, myocardial infarction, and all-cause mortality up to 1 year after stroke. The study subjects were categorized into 4 SBP trajectory groups: low (27.0%), moderate (59.5%), persistently high (1.2%), and slowly dropping (12.4%). In the first 3 groups, SBP decreased during the first 3 to 7 days and remained steady thereafter. In the slowly dropping SBP group, SBPs decreased from 182 to 135 mm Hg during the first 30 days, then paralleled the trajectory of the moderate SBP group. Compared with the reference, the moderate SBP group, the slowly dropping SBP group was at higher risk for the primary outcome (adjusted hazard ratio [HR], 1.32; 95% CI, 1.05‒1.65) and mortality (adjusted HR, 1.35; 95% CI, 1.03‒1.78). Primary outcome rates were similarly high in the persistently high SBP group. Conclusions Four 1-year longitudinal SBP trajectories were identified in patients with acute ischemic stroke. Patients in the slowly dropping SBP and persistently high SBP trajectory groups were prone to adverse cardiovascular outcomes after stroke.

Abstract TP180: Secular Trends For Demographics, Characteristics, Management, And Clinical Outcome Of Young Adults With Acute Ischemic Stroke

Background: The incidence of stroke in young adults is increasing with the growing prevalence of stroke risk factors among young adults over the last decades. However, studies on secular trends in the young-age stroke population are scarce.

Methods: We extracted data of acute ischemic stroke (AIS) patients aged 18-50 (n=7053; age, 43±6; male, 72%) from the multicenter stroke registry in South Korea. Demographics, risk factors, stroke characteristics, management, and clinical outcomes in young adults with AIS were summarized according to calendar year (2008-2019). Trends analysis was conducted using a linear regression model for continuous variables and the Mann-Kendall trend test for categorical variables.

Results: There was no significant change between 2008 and 2019 in the proportions of young adults among female patients (7.1% to 7.0%, p=0.44). However, the proportions of young adults within male patients tended to decrease (12.4% to 10.7%; p=0.001) The prevalence, and awareness of risk factors were unchanged during the study period. Regarding stroke subtypes, there was a significant increase in other determined etiology (8% to 20%; p<0.001) and a tendency to decrease in large artery atherosclerosis (26% in 2008; 34% in 2009 to 26% in 2019; p=0.28). The endovascular thrombectomy (EVT) rate increased (2% to 8%; p<0.001), but the intravenous thrombolysis rate (8.8% to 10.6%) and door-to-needle time (38 to 36 min) did not change. Use of dual antiplatelet (DAPT; 29% to 55%; p=<0.001) increased and direct oral anticoagulants (DOACs) in patients with atrial fibrillation tended to increase (11.7% in 2013 to 44.8% in 2019; p=0.07; DOAC began to be used in 2013 in Korea). However, the use of anticoagulants among young adult patients having atrial fibrillation tended to decrease (80% to 66%; p=0.054). Clinical outcomes, including a 3-month modified ranking scale 0-2 (84.6% to 85.2%), 1-year mortality (2.8% to 2.4%), and stroke recurrence rate (4.5 to 5.6%), did not improve during the study period.

Conclusions: Among young adults with ischemic stroke, the EVT rate and use of DAPT or DOACs increased. Still, awareness of risk factors, door-to-needle time, and anticoagulation for atrial fibrillation required more attention to improve clinical outcomes.

Abstract WP186: Long-term Incidence Of Gastrointestinal Bleeding After Ischemic Stroke

Background: Incidence of gastrointestinal (GI) bleeding after acute ischemic stroke (AIS) was reported as 1.5% during hospitalization, one-thirds of which required blood transfusion. However, it is not known about the long-term incidence and the incidence rates by period after AIS.

Methods: AIS patients who were admitted to the 14 participating hospitals between 2011 and 2013 were identified using a nationwide multicenter prospective stroke registry database. GI bleeding was captured with related diagnosis codes by International Classification of Diseases-10th Revision through the linkage between the registry database and the claims data. Bleeding requiring at least 2 packs of blood transfusion was defined as major GI bleeding. Incidence rates were calculated for each period as follow; 0-30 days, 31-90 days, 91-180 days, 181-365 days, 1-2 years, 2-3years, after 3 years.

Results: Of 10,818 AIS patients, 59.0% were male and mean age was 67.5 ± 12.9 years. The median follow-up duration was 3.1 (interquartile range 2.3 to 4.0) years. During 31,208 person-years, 947 patients (8.8%) had 1,224 episodes of major GI bleeding. Annual incidence rate was 3.92 per 100 person-years. The incidence rates by periods were the highest at 19.21 per 100 person-years in the first month of AIS, gradually decreased to 9.02 in one to three months, 6.18 in three to six months, and 3.48 in six to twelve months. After three years, it remained at about 2.62 events per 100 person-years. During the observation period, only one major GI bleeding occurred without recurrence in about 80% of patients, about 13% recurred twice, and about 6% of patients had three or more recurrences. In the multivariable recurrent event analysis, anemia at admission, lower eGFR below 60, and mRS at 3 months ≥4 were independently associated with higher risk of major GI bleeding during the most of the observation period above 3 years.

Conclusions: Major GI bleeding, requiring transfusion, seems to occur frequently after AIS, and the risk was gradually decreased after stroke. The efforts are needed to prevent it, especially in stroke patients with anemia and decreased renal function.

Treatment Intensification for Elevated Blood Pressure and Risk of Recurrent Stroke

Background

It remains unclear whether physicians' attitudes toward timely management of elevated blood pressure affect the risk of stroke recurrence.

Methods and Results

From a multicenter stroke registry database, we identified 2933 patients with acute ischemic stroke who were admitted to participating centers in 2011, survived at the 1‐year follow‐up period, and returned to outpatient clinics ≥2 times after discharge. As a surrogate measure of physicians' attitude, individual treatment intensification (TI) scores were calculated by dividing the difference between the frequencies of observed and expected medication changes by the frequency of clinic visits and categorizing them into 5 groups. The association between TI groups and the recurrence of stroke within 1 year was analyzed using hierarchical frailty models, with adjustment for clustering within each hospital and relevant covariates. Mean±SD of the TI score was −0.13±0.28. The TI score groups were significantly associated with increased risk of recurrent stroke compared with Group 3 (TI score range, −0.25 to 0); Group 1 (range, −1 to −0.5), adjusted hazard ratio (HR) 13.43 (95% CI, 5.95–30.35); Group 2 (range, −0.5 to −0.25), adjusted HR 4.59 (95% CI, 2.01–10.46); and Group 4 (TI score 0), adjusted HR 6.60 (95% CI, 3.02–14.45); but not with Group 5 (range, 0–1), adjusted HR 1.68 (95% CI, 0.62–4.56). This elevated risk in the lowest TI score groups persisted when confining analysis to those with hypertension, history of blood pressure‐lowering medication, no atrial fibrillation, and regular clinic visits and stratifying the subjects by functional capacity at discharge.

Conclusions

A low TI score, which implies physicians' therapeutic inertia in blood pressure management, was associated with a higher risk of recurrent stroke. The TI score may be a useful performance indicator in the outpatient clinic setting to prevent recurrent stroke.

Five-Year Risk of Acute Myocardial Infarction After Acute Ischemic Stroke in Korea

Background

The long‐term incidence of acute myocardial infarction (AMI) in patients with acute ischemic stroke (AIS) has not been well defined in large cohort studies of various race‐ethnic groups.

Methods and Results

A prospective cohort of patients with AIS who were registered in a multicenter nationwide stroke registry (CRCS‐K [Clinical Research Collaboration for Stroke in Korea] registry) was followed up for the occurrence of AMI through a linkage with the National Health Insurance Service claims database. The 5‐year cumulative incidence and annual risk were estimated according to predefined demographic subgroups, stroke subtypes, a history of coronary heart disease (CHD), and known risk factors of CHD. A total of 11 720 patients with AIS were studied. The 5‐year cumulative incidence of AMI was 2.0%. The annual risk was highest in the first year after the index event (1.1%), followed by a much lower annual risk in the second to fifth years (between 0.16% and 0.27%). Among subgroups, annual risk in the first year was highest in those with a history of CHD (4.1%) compared with those without a history of CHD (0.8%). The small‐vessel occlusion subtype had a much lower incidence (0.8%) compared with large‐vessel occlusion (2.2%) or cardioembolism (2.4%) subtypes. In the multivariable analysis, history of CHD (hazard ratio, 2.84; 95% CI, 2.01–3.93) was the strongest independent predictor of AMI after AIS.

Conclusions

The incidence of AMI after AIS in South Korea was relatively low and unexpectedly highest during the first year after stroke. CHD was the most substantial risk factor for AMI after stroke and conferred an approximate 5‐fold greater risk.

Neurologic deterioration in patients with acute ischemic stroke or transient ischemic attack

OBJECTIVE

To improve epidemiologic knowledge of neurologic deterioration (ND) in patients with acute ischemic stroke (AIS).

METHODS

In this prospective observational study, we captured ND prospectively in 29,446 patients with AIS admitted to 15 hospitals in Korea within 7 days of stroke onset. ND was defined as an increase in NIH Stroke Scale (NIHSS) score ≥2 (total), or ≥1 (motor or consciousness), or any new neurologic symptoms. Change in incidence rate after stroke onset, causes, factors associated with ND, modified Rankin Scale (mRS) score at 3 months and 1 year, and a composite of stroke, myocardial infarction, and all-cause death at 1 year were assessed.

RESULTS

ND occurred in 4,299 (14.6%) patients. The highest rate, 6.95 per 1,000 person-hours incidence, was within the first 6 hours, which decreased to 2.09 within 24-48 hours, and 0.66 within 72-96 hours after stroke onset. Old age, female sex, diabetes, early arrival, large artery atherosclerosis as a stroke subtype, high NIHSS scores, glucose level, systolic blood pressure, leukocytosis at admission, recanalization therapy, TIA without a relevant lesion, and steno-occlusion of relevant arteries were associated with ND. The causes were stroke progression (71.8%) followed by recurrence (8.5%). Adjusted relative risks (95% CI) for poor outcome (mRS 3-6) at 3 months and 1 year were 1.75 (1.70-1.80) and 1.70 (1.65-1.75), respectively. The adjusted hazard ratio (95% CI) for the composite event was 1.59 (1.45-1.74).

CONCLUSIONS

ND should be taken into consideration as a factor that may influence the outcome in acute ischemic stroke.

Predicting Functional Outcome Based on Linked Data After Acute Ischemic Stroke: S-SMART Score

Prediction of outcome after stroke may help clinicians provide effective management and plan long-term care. We aimed to develop and validate a score for predicting good functional outcome available for hospitals after ischemic stroke using linked data. A total of 22,005 patients with acute ischemic stroke from the Clinical Research Center for Stroke Registry between July 2007 and December 2014 were included in the derivation group. We assessed functional outcomes using a modified Rankin scale (mRS) score at 3 months after ischemic stroke. We identified predictors related to good 3-month outcome (mRS score ≤ 2) and developed a score. External validations (geographic and temporal validations) of the developed model were performed. The prediction model performance was assessed using the area under the receiver operating characteristic curve (AUC) and the calibration test. Stroke severity, sex, stroke mechanism, age, pre-stroke mRS, and thrombolysis/thrombectomy treatment were identified as predictors for 3-month good functional outcomes in the S-SMART score (total 34 points). Patients with higher S-SMART scores had an increased likelihood of a good outcome. The AUC of the prediction score was 0.805 (0.798-0.811) in the derivation group and 0.812 (0.795-0.830) in the geographic validation group for good functional outcome. The AUC of the model was 0.812 (0.771-0.854) for the temporal validation group. Moreover, they had good calibration. The S-SMART score is a valid and useful tool to predict good functional outcome following ischemic stroke. This prediction model may assist in the estimation of outcomes to determine care plans after stroke.

Development of stroke identification algorithm for claims data using the multicenter stroke registry database

BACKGROUND

Identifying acute ischemic stroke (AIS) among potential stroke cases is crucial for stroke research based on claims data. However, the accuracy of using the diagnostic codes of the International Classification of Diseases 10th revision was less than expected.

METHODS

From the National Health Insurance Service (NHIS) claims data, stroke cases admitted to the hospitals participating in the multicenter stroke registry (Clinical Research Collaboration for Stroke in Korea, CRCS-K) during the study period with principal or additional diagnosis codes of I60-I64 on the 10th revision of International Classification of Diseases were extracted. The datasets were randomly divided into development and validation sets with a ratio of 7:3. A stroke identification algorithm using the claims data was developed and validated through the linkage between the extracted datasets and the registry database.

RESULTS

Altogether, 40,443 potential cases were extracted from the NHIS claims data, of which 31.7% were certified as AIS through linkage with the CRCS-K database. We selected 17 key identifiers from the claims data and developed 37 conditions through combinations of those key identifiers. The key identifiers comprised brain CT, MRI, use of tissue plasminogen activator, endovascular treatment, carotid endarterectomy or stenting, antithrombotics, anticoagulants, etc. The sensitivity, specificity, and diagnostic accuracy of the algorithm were 81.2%, 82.9%, and 82.4% in the development set, and 80.2%, 82.0%, and 81.4% in the validation set, respectively.

CONCLUSIONS

Our stroke identification algorithm may be useful to grasp stroke burden in Korea. However, further efforts to refine the algorithm are necessary.

Three-month modified Rankin Scale as a determinant of 5-year cumulative costs after ischemic stroke

Objective

Stroke is a devastating and costly disease; however, there is a paucity of information on long-term costs and on how they differ according to 3-month modified Rankin scale (mRS) score, which is a primary outcome variable in acute stroke intervention trials.

Methods

We analyzed a prospective multicenter stroke registry (Clinical Research Collaboration for Stroke in Korea) database through linkage with claims data from the National Health Insurance Service with follow-up to December 2016. Healthcare expenditures were converted into daily cost individually, and annual and cumulative costs up to 5 years were estimated and compared according to the 3-month mRS score.

Results

Between January 2011 and November 2013, 11,136 patients were enrolled in the study. The mean age was 68 years, and 58% were men. The median follow-up period was 3.9 years (range 0–5 years). Mean cumulative cost over 5 years was $117,576 (US dollars [USD]); the cost in the first year after stroke was the highest ($38,152 USD), which increased markedly from the cost a year before stroke ($8,718 USD). The mean 5-year cumulative costs differed significantly according to the 3-month mRS score (p < 0.001); the costs for a 3-month mRS score of 0 or 5 were $53,578 and $257,486 USD, respectively. Three-month mRS score was an independent determinant of long-term costs after stroke.

Conclusions

We show that 3-month mRS score plays an important role in the prediction of long-term costs after stroke. Such estimates relating to 3-month mRS categories may be valuable when undertaking health economic evaluations related to stroke care.

Abstract WP94: Higher Mortality in Slow Blood Pressure Droppers: Blood Pressure Trajectory Groups of 1-Year After Acute Ischemic Stroke

Introduction: Although the effect of blood pressure in post-stroke outcome is well recognized, the long-term time course of BP following acute ischemic stroke and it’s influence to outcomes have not been well elucidated.

Method: From a multicenter prospective registry of acute ischemic stroke patients, a total of 5,514 patients with measurement of systolic blood pressure (SBP) in more than 2 of 7 prespecified time points up to 1 year after symptom onset were analyzed. The patients were grouped according to longitudinal SBPs of each patient using a group-based trajectory model, and number of groups were determined by the optimal delta-Bayesian Information Criterion. Outcome measures, which were stroke recurrence, mortality and composite of each events along with myocardial infarction were prospectively collected up to 1 year after symptom onset.

Results: Patients were categorized into four groups according to their SBP trajectories: low (27.0%), moderate (59.5%), persistently high (1.2%), and slowly dropping (12.4%). After adjustment for pre-determined covariates, there were higher risk of stroke recurrence in persistently high SBP group (hazard ratio (HR), 2.28 [95% confidence interval (CI), 1.01-5.12]). Mortality was higher only in the slowly dropping SBP group (HR, 1.50 [95% CI, 1.09-2.05]). Composite events were higher in both persistently high (HR, 1.96 [95% CI, 1.02-3.75]) and slowing dropping (HR, 1.54 [95% CI, 1.18-2.00]) SBP groups.

Conclusion: There were a group of patterns in long-term longitudinal SBP changes after acute ischemic stroke. Especially, slow BP droppers might have a distinct nature with higher mortality and would be a target for future investigations.

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.

Silk peptide treatment potentiates natural killer cell activity in vitro and induces natural killer cell maturation and activation in mouse splenocytes

Context: Silk peptide from cocoons of silkworm (Bombyx mori L., Bombycidae) has been employed as a biomedical material and exhibits various bioactivities, including immune-modulating activity. Objective: We analyzed whether silk peptide exerts direct modulating effects on NK cells using an NK cell line in vitro and ex vivo splenocytes. We also attempted to delineate the mechanism underlying the modulation. Material and methods: In vitro activity of silk peptide on NK cells was determined by measurement of cytolytic activity against K562 cells at an effector-to-target ratio of 5:1 after incubation of NK-92MI cells with silk peptide (0-2000 μg/mL) for 48 and 72 h. Ex vivo activity of silk peptide on mouse splenic NK cells was determined similarly by using YAC-1 cells. Results: Treatment of NK-92MI NK cells with silk peptide (500-2000 μg/mL) significantly increased cytolytic activity on target cells by 2- to 4-fold. The same concentrations (500-2000 μg/mL) of silk peptide treatment also significantly enhanced the cytolytic activity of splenic NK cells against YAC-1 cells. Silk peptide treatment of IL-2-stimulated splenocytes induced enhanced expression of Th1, 2 and 17 cytokines including TNF-α, IFN-γ, IL-6, IL-4 and IL-17. Finally, ex vivo treatment with silk peptide on mouse splenocytes significantly enhanced the degree of NK cell maturation in a dose-dependent manner from 3.49 to 23.79%. Discussion and conclusions: These findings suggest that silk peptide stimulates NK cells, thereby influencing systemic immune functions and improving natural immunity. Thus, silk peptide could be useful as a complementary therapy in cancer patients.

Characteristics and management of stroke in Korea: 2014–2018 data from Korean Stroke Registry

Background

Lifestyle changes and evolving healthcare practices in Korea have influenced disease patterns and medical care. Since strokes have high disease burden in countries with aging populations, it is necessary to evaluate the associated recent disease characteristics and patient care patterns. The Korean Stroke Registry is a nationwide, multicenter, prospective, hospital-based stroke registry in Korea used to monitor these changes across the population.

Aims

We aimed to evaluate the recent status of clinical characteristics and management of stroke cases in order to identify changes in the Korean population across time.

Methods

This study used Korean Stroke Registry data from patients experiencing ischemic stroke or transient ischemic attack patients, between 2014 and 2018. We analyzed data on demographics, risk factors, stroke subtypes, and treatments that included thrombolysis.

Results

A total of 39,291 patients (mean age 68.0 ± 13.0, 58.3% male) were analyzed. The proportions of hypertension, diabetes mellitus, dyslipidemia, atrial fibrillation, and prior stroke were 63.4%, 30.9%, 27.7%, 19.4%, and 17.1%, respectively. In the stroke subtype analysis, the frequency of large artery atherosclerosis was highest (32.6%), followed by cardioembolism (21.3%) and small vessel occlusion (19.9%). Acute reperfusion therapy was conducted in 15.3% of cases (11.7% using intravenous tPA and 7.3% using intra-arterial thrombectomy). Intra-arterial thrombectomy also demonstrated a steep increasing trend over time (RR 1.095 (1.060–1.131), p < 0.001).

Conclusions

This study provided analysis of nationwide, hospital-based, quality-controlled data from the Korean Stroke Registry database regarding changes in the characteristics, risk factors, and treatments of strokes in Korea.

Association between time to treatment and functional outcomes according to the Diffusion-Weighted Imaging Alberta Stroke Program Early Computed Tomography Score in endovascular stroke therapy

BACKGROUND AND PURPOSE

The rate at which the chance of a good outcome of endovascular stroke therapy (EVT) decays with time when eligible patients are selected by baseline diffusion-weighted magnetic resonance imaging (DWI-MRI) and whether ischaemic core size affects this rate remain to be investigated.

METHODS

This study analyses a prospective multicentre registry of stroke patients treated with EVT based on pretreatment DWI-MRI that was categorized into three groups: small [Diffusion-Weighted Imaging Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS)] (8-10), moderate (5-7) and large (<5) cores. The main outcome was a good outcome at 90 days (modified Rankin Scale 0-2). The interaction between onset-to-groin puncture time (OTP) and DWI-ASPECTS categories regarding functional outcomes was investigated.

RESULTS

Ultimately, 985 patients (age 69 ± 11 years; male 55%) were analysed. Potential interaction effects between the DWI-ASPECTS categories and OTP on a good outcome at 90 days were observed (P_interaction  = 0.06). Every 60-min delay in OTP was associated with a 16% reduced likelihood of a good outcome at 90 days amongst patients with large cores, although no associations were observed amongst patients with small to moderate cores. Interestingly, the adjusted rates of a good outcome at 90 days steeply declined between 65 and 213 min of OTP and then remained smooth throughout 24 h of OTP (P_nonlinearity  = 0.15).

CONCLUSIONS

Our study showed that the probability of a good outcome after EVT nonlinearly decreased, with a steeper decline at earlier OTP than at later OTP. Discrepant effects of OTP on functional outcomes by baseline DWI-ASPECTS categories were observed. Thus, different strategies for EVT based on time and ischaemic core size are warranted.

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.

Abstract WP552: Post-stroke Dementia Incidence and Risk Factors in Korea: Linked Big Data Between the Clinical Research Center for Stroke Data and the Health Insurance Review & Assessment Service Data Analysis

Background: Post-stroke dementia is an important factor of poor functional outcome following stroke. However, few longitudinal studies on the incidence and risk factors of dementia after stroke have been performed.

Hypothesis: We aimed to investigate the incidence and clinical factors related to dementia after ischemic stroke.

Methods: A total of 47,779 patients with acute ischemic stroke (within 7 days after stroke onset) were enrolled, who were registered in the Clinical Research Center for Stroke (CRCS) registry from 2006 to 2014 and successfully linked the Health Insurance Review and Assessment Service (HIRA) big database. All included patients did not have dementia before index stroke. The incidence of post-stroke dementia was identified using International Classification of Diseases, Tenth Revision, dementia diagnosis codes (F00, F01, F02, F03, and G30) with prescription of an anti-dementia medications after index stroke based on linked big data.

Results: Of the 47,779 patients, 10,357 patients (21.7%) had post-stroke dementia. The cumulative incidence of dementia after stroke was 10.4% after 1 year, 15.6 % after 3 years, 19.5% after 5 years, 22.9% after 7 years, and 27.1% after 10 years. The crude incidence rate of post-stroke dementia was 40.03 cases per 1000 person-years in this stroke registry based linkage big data. Post-stroke dementia groups were older, more frequently female, and were more likely to have severe stroke, history of stroke, lower education level, dependency before stroke.

Conclusions: Our study demonstrated that about 22% of ischemic stroke patients were demented after stroke, particularly were associated with history of stroke, and stroke severity. These patients with high risk of dementia should be controlled risk factors for preventing cognitive impairment following stroke.

Abstract TP386: The Risk Score to Predict Functional Outcome Following Acute Ischemic Stroke Based on the Linked Big Data between theClinical Research Center for Stroke Data and the Health Insurance Review and Assessment Service Data

Introduction: Prediction of outcome after stroke may help clinicians provide effective stroke management and plan long-term care for patients.

Hypothesis: We aimed to develop and validate a risk score for predicting functional outcome available at hospital after ischemic stroke using linked big data.

Methods: A total of 24,907 cases with acute ischemic stroke (within 7 days after onset) were enrolled, who were registered in the Clinical Research Center for Stroke (CRCS) registry from 2006 to 2014 and successfully linked the Health Insurance Review and Assessment Service (HIRA) database. Among them, 22,005 cases were derivation and internal validation group, and 2,902 cases were external validation group. We assessed the functional outcome using a modified Rankin Scale (mRS) at 3-month after onset ischemic stroke. We evaluated the predictive value of variables associated with the favorable 3-month outcome (mRS ≤ 2) and developed the score using the logistic regression coefficients. The prediction model performance was assessed by the area under the receiver-operating characteristic curve (AUC).

Results: Proportion of cases with favorable outcome were 67.0% (n=14,748) in the derivation and internal validation group, and 68.4% (n=1,986) in the external validation group. Multivariable predictors of functional outcome at 3-month included age, gender, stroke severity, body mass index, stroke subtype, previous functional status, recanalization treatment, pre-stroke antiplatelet or anticoagulation therapy, fasting glucose level, history of stroke, hyperlipidemia, diabetes mellitus, hypertension, congestive heart failure, kidney disease on dialysis, cancer before the stroke. The AUC of the prediction model was 0.855 (0.850 - 0.860) in the derivation group and 0.854 (0.849 - 0.860) in the internal validation group for 3-month functional outcome. In addition, the AUC of the model was 0.860 (0.846 - 0.874) in the external validation group for outcome at 3-month.

Conclusions: This prediction of functional outcome model is a valid clinical tool to predict functional outcome following ischemic stroke and reliable externally. This prediction model may assist to estimate functional outcome after stroke and to decide the care plan after stroke.

Estimation of Acute Infarct Volume with Reference Maps: A Simple Visual Tool for Decision Making in Thrombectomy Cases

BACKGROUND AND PURPOSE

Thrombectomy within 24 hours can improve outcomes in selected patients with a clinical-infarct mismatch. We devised an easy-to-use visual estimation tool that allows infarct volume estimation in centers with limited resources.

METHODS

We identified 1,031 patients with cardioembolic or large-artery atherosclerosis infarction on diffusion-weighted images (DWIs) obtained before recanalization therapy and within 24 hours of onset, and occlusion of the internal carotid or middle cerebral artery. Acute DWIs were mapped onto a standard template and used to create visual reference maps with known lesion volumes, which were then used in a validation study (with 130 cases) against software estimates of infarct volume.

RESULTS

The DWI reference map chart comprises 144 maps corresponding to 12 different infarct volumes (0.5, 1, 2, 3, 5, 7, 9, 11, 13, 15, 17, and 19 mL) in each of 12 template slices (Montreal Neurological Institute z-axis -15 to 51 mm). Infarct volume in a patient is estimated by selecting a slice with a similar infarct size at the corresponding z-axis level on the reference maps and then adding up over all slices. The method yielded good correlations to software volumetrics and was easily learned by both experienced and junior physicians, with approximately 1 to 2 minutes spent per case. The sensitivity, specificity, and accuracy for detecting threshold infarct volumes (<21, <31, and <51 mL) were very high (all about >90%).

CONCLUSION

s We developed easy-to-use reference maps that allow prompt and reliable visual estimation of infarct volumes for triaging patients to thrombectomy in acute stroke.

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.

Oral Administration of Silk Peptide Enhances the Maturation and Cytolytic Activity of Natural Killer Cells

Silk peptide, the hydrolysate of silk protein derived from cocoons, has been employed as a biomedical material and is believed to be safe for human use. Silk peptide display various bioactivities, including anti-inflammatory, immune-regulatory, anti-tumor, anti-viral, and anti-bacterial. Although earlier investigations demonstrated that silk peptide stimulates macrophages and the production of pro-inflammatory cytokines, its effect on natural killer (NK) cell function has not yet been explored. In this study, we initially confirmed that silk peptide enhances NK cell activity in vitro and ex vivo. To assess the modulatory activity of silk peptide on NK cells, mice were fed various amounts of a silk peptide-supplemented diet for 2 months and the effects on immune stimulation, including NK cell activation, were evaluated. Oral administration of silk peptide significantly enhanced the proliferation of mitogen- or IL-2-stimulated splenocytes. In addition, oral silk peptide treatment enhanced the frequency and degree of maturation of NK cells in splenocytes. The same treatment also significantly enhanced the target cell cytolytic activity of NK cells, which was determined by cell surface CD107a expression and intracellular interferon-γ expression. Finally, oral administration of silk peptide stimulated T helper 1-type cytokine expression from splenic lymphocytes. Collectively, our results suggest that silk peptide potentiates NK cell activity in vivo and could be used as a compound for immune-modulating anti-tumor treatment.

Serotonin transporter gene polymorphisms may be associated with poststroke neurological recovery after escitalopram use

OBJECTIVE

Selective serotonin reuptake inhibitors (SSRIs) putatively improve neurological recovery after stroke. We aimed to investigate whether serotonin transporter (SERT) gene polymorphisms are related to the responsiveness to SSRIs in the poststroke neurological recovery.

METHODS

This was a post hoc analysis of the EMOTION study (ClinicalTrials.gov NCT01278498), a randomised, placebo-controlled, double-blind trial examining the efficacy of escitalopram on emotional and neurological disturbances after acute stroke. Patients with no/minimal disability initially (modified Rankin Scale (mRS) 0-1) were excluded. Of the participants, 301 underwent genetic studies of the STin2 (a variable number tandem repeat (VNTR) in intron 2) (STin2 12/10 and STin2 12/12 genotypes) and 5-HTTLPR (a variable-length repeat in the promoter region) polymorphisms of SERT. We explored whether neurological function (National Institutes of Health Stroke Scale (NIHSS) score and mRS) at 3 months would differ according to SERT polymorphisms within each treatment arm (escitalopram and placebo).

RESULTS

Among the escitalopram users (n=159), neurological function in subjects with STin2 12/10 (n=29) improved significantly more than that in STin2 12/12 carriers (n=130) at 3 months. After adjusting for age, initial NIHSS and depression, STin2 12/10 independently predicted a good clinical outcome (mRS 0-1) (OR 2.99, 95% CI 1.04 to 8.58) at 3 months. However, differences between STin2 polymorphisms were not shown in the placebo group (n=142). 5-HTTLPR polymorphisms were not associated with neurological recovery in any treatment group.

CONCLUSION

STin2 VNTR polymorphisms may be associated with poststroke neurological recovery after SSRI therapy. Further studies are needed to identify the role of serotonin in neurological recovery after stroke.

Activated leucocyte cell adhesion molecule (ALCAM/CD166) regulates T cell responses in a murine model of food allergy

Food allergy is a major public health problem. Studies have shown that long-term interactions between activated leucocyte cell adhesion molecule (ALCAM/CD166) on the surface of antigen-presenting cells, and CD6, a co-stimulatory molecule, influence immune responses. However, there are currently no studies on the functions of ALCAM in food allergy. Therefore, we aimed to identify the functions of ALCAM in ovalbumin (OVA)-induced food allergy using ALCAM-deficient mice. Wild-type (WT) and ALCAM-deficient (ALCAM^-/- ) mice were sensitized intraperitoneally and with orally fed OVA. The mice were killed, and parameters related to food allergy and T helper type 2 (Th2) immune responses were analysed. ALCAM serum levels increased and mRNA expression decreased in OVA-challenged WT mice. Serum immunoglobulin (Ig)E levels, Th2 cytokine mRNA and histological injuries were higher in OVA-challenged WT mice than in control mice, and these were attenuated in ALCAM^-/- mice. T cell proliferation of total cells, CD3⁺ CD4⁺ T cells and activated T cells in immune tissues were diminished in OVA-challenged ALCAM^-/- mice. Proliferation of co-cultured T cells and dendritic cells (DCs) was decreased by the anti-CD6 antibody. In addition, WT mice sensitized by adoptive transfer of OVA-pulsed ALCAM^-/- BM-derived DCs showed reduced immune responses. Lastly, serum ALCAM levels were higher in children with food allergy than in control subjects. In this study, serum levels of ALCAM were elevated in food allergy-induced WT mice and children with food allergy. Moreover, immune responses and T cell activation were attenuated in OVA-challenged ALCAM^-/- mice. These results indicate that ALCAM regulates food allergy by affecting T cell activation.

Abstract TMP89: Early Heart Rate as an Outcome Predictor in Atrial Fibrillation Related Acute Ischemic Stroke

Backgrounds: Previous studies demonstrated the association of resting heart rate with cardiovascular outcomes while there were only few evidence for patients who experienced ischemic stroke. As atrial fibrillation (AF) is characterized by rapidity and irregularity of heart rate, heart rate characteristics might be a predictor for future vascular event in patients with AF acute ischemic stroke.

Methods: From a multicenter prospective registry of stroke patients, acute ischemic stroke patients with AF who admitted within 48 hours after stroke onset were included. Heart rate data during the first 24 hours after admission were collected and level and variability of heart rate were assessed by mean and coefficient of variation (CV). Primary outcome was a composite of stroke recurrence, myocardial infarction and all-cause death, which was prospectively captured until 1 year after stroke onset.

Results: A total of 2,046 patients were included for the final analysis. There were 102 (5.0%) stroke recurrence, 9 (0.4%) myocardial infarction and 440 (21.5%) death events within 1 year after stroke onset. Proportional hazards regression models were constructed and the non-linearity of effects of heart rate parameters were examined for outcome events. Among all the associations, effects of mean heart rate on primary outcome and all-cause mortality were non-linear ( p’s for quadratic effect = 0.017 and 0.032, respectively). The overall effects were significant only for effects of mean heart rate on primary outcome and all-cause mortality (P =0.013 and P=0.006, respectively). Effects of CV on outcome variables were not significant.

Conclusion: This study suggests that mean heart rate during the first day of hospitalization was a predictor of future vascular events in AF patients presenting with acute ischemic stroke and the association seems to be non-linear ‘J shaped’. However, heart rate variability did not affect.

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.

Relationship between sputum clusterin levels and childhood asthma

BACKGROUND

Clusterin is a sensitive cellular biosensor of oxidative stress and has been studied as a biomarker for inflammation-associated diseases. Clusterin levels in childhood asthma have not been evaluated.

OBJECTIVES

(1) To evaluate sputum clusterin levels in children with asthma compared to a control group. (2) To assess the relationships between sputum clusterin levels and airway inflammation, pulmonary function, and bronchial hyperresponsiveness.

METHODS

This study included 170 children aged 5-18 years with stable asthma (n = 91), asthma exacerbation (n = 29), or no asthma (healthy controls; n = 50). Induced sputum, pulmonary function, and methacholine challenge tests were performed. Stable asthma was classified into two groups according to the severity. Clusterin levels in sputum were measured using an enzyme-linked immunosorbent assay.

RESULTS

Children with stable asthma had a higher clusterin level than healthy controls [4540 (3872-5651) pg/mL vs. 3857 (1054-4369) pg/mL, P < 0.001]. The clusterin level was also more elevated in eosinophil-dominant sputum than in non-eosinophilic sputum in stable asthma [5094 (4243-6257) pg/mL vs. 4110 (1871-4839) pg/mL, P = 0.0017]. Clusterin levels were associated with asthma severity. Paradoxically, clusterin levels were lower during asthma exacerbation than in stable asthma [1838 (350-4790] pg/mL vs. 4540 (3872-5651) pg/mL, P < 0.001]. Clusterin levels were strongly correlated with the methacholine concentration that caused a 20% decrease in the forced expiratory volume in 1 s (r = -0.617, P < 0.001); there was no significant correlation between clusterin levels and other pulmonary function parameters.

CONCLUSIONS AND CLINICAL RELEVANCE

Clusterin levels were altered in children with stable asthma and asthma exacerbation because of its antioxidant and anti-inflammatory effects. Clusterin may be a marker that reflects airway inflammation and severity of symptoms, and it can be used in the assessment and management of childhood asthma.

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.

Abstract 183: Effect of Statin in Acute Cardioembolic Stroke Patients Who Are not Indicated According to Current Guidelines

Background: There is no specific recommendation on statin therapy for cardioembolic stroke (CES) patients in current stroke guidelines. We evaluated the effect of statin on major vascular events following acute ischemic stroke in patients with CES and no other indications for statin.

Methods: Using a prospective multicenter stroke registry database, we identified acute ischemic stroke patients who were hospitalized between 2008 and 2015 and were categorized into CES according to the Trial of Org 10172 in Acute Stroke Treatment classification. Patients who had established indications for statin in accordance with the recent stroke guidelines were excluded. Primary outcome measure was a major vascular event, a composite of stroke recurrence, myocardial infarction and vascular death; and secondary outcome measures were stroke recurrence and all-cause death. We performed frailty model analysis to estimate hazard ratios (HRs) of statin therapy on outcomes accounting for variation in quality of care among centers. Stabilized inverse probability of treatment weighting method with propensity scores was used to remove baseline imbalances between statin users and non-users.

Results: Of the 6124 CES patients, 2987 patients (male, 52%; mean age, 73±12 years) met the eligibility criteria; and 2125 (71%) of 2987 patients were on statin at discharge. Compared to the non-users, the statin users were more likely to arrive at hospitals later, have milder neurologic deficits at presentation, be on stain prior to index stroke and have hyperlipidemia and were less likely to have atrial fibrillation and occlusion of relevant cerebral arteries. During the median follow-up of 364 days, major vascular events were observed in 118 patients (5.6%) among the statin users and 177 patients (20.5%) among the non-users, respectively (p<0.001 on log rank test); the adjusted HR of statin therapy was 0.35 (95% confidence interval, 0.27-0.46). The adjusted HRs of statin therapy were 0.71 (0.49-1.04) for stroke recurrence and 0.55 (0.46-0.66) for all-cause death, respectively.

Conclusion: This study suggests that statin therapy may reduce major vascular events and all-cause death in cardioembolic stroke patients without definite indications for statin.

Abstract TP184: Impact on Ischemic Stroke Subtypes of Fasting and Non-fasting Triglycerides

Introduction: Remnant cholesterol, comprising triglycerides(TG)-rich lipoproteins, accumulates in intimal foam cells and causes atherosclerosis. Fasting TG is reported to be associated with atherosclerotic stroke, but relationships between non-fasting TG (NFTG) and ischemic stroke subtypes are unknown. Recently NFTG was found to produce endothelial dysfunction. This study aimed to elucidate the association of fasting and NFTG with ischemic stroke subtypes, especially large-artery atherosclerosis (LAA) and small vessel occlusion (SVO).

Methods: Using a prospective multicenter stroke registry (Clinical Research Center for Stroke - 5th division), we identified acute ischemic stroke patients, hospitalized within 48 hours of onset, and whose fasting and non-fasting TG values were available. We measured lipid profiles in each individual twice; at presentation and after overnight fasting. Initial TG were regarded as NFTG when measured within 8 hours from last mealtime.

Results: Total 3,170 patients were analyzed. Stroke subtypes were categorized as LAA (37.9%), SVO (18.7%) and non-LAA and non-SVO (43.4%). Lipid levels according stroke subtypes are presented in Table. Lipid levels were divided by quartiles and the highest quartile was compared to others. In multinomial analyses compared to non-LAA and non-SVO group, fasting TG was associated with LAA (adjusted ORs 1.33 [95% CIs 1.09 - 1.62]) and SVO (1.61 [1.27 - 2.04]). NFTG was associated not with LAA (1.05 [0.87 - 1.28]), but with SVO (1.36 [1.08 - 1.71]). With respect to other lipid levels, fasting and non-fasting LDL were associated with both LAA (1.57 [1.29 - 1.90], fasting; 1.89 [1.56 - 2.29], non-fasting) and SVO (1.40 [1.11 - 1.77], fasting; 1.74 [1.38 - 2.19], non-fasting).

Conclusions: This study may be the first one to demonstrate an association between non-fasting TG and SVO. It should be explored further on mechanisms of differential effect of fasting and non-fasting TG on ischemic stroke subtypes.

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.

Prestroke Antiplatelet Effect on Symptomatic Intracranial Hemorrhage and Functional Outcome in Intravenous Thrombolysis

Background and Purpose

About 30%-40% of stroke patients are taking antiplatelet at the time of their strokes, which might increase the risk of symptomatic intracranial hemorrhage (SICH) with intravenous tissue plasminogen activator (IV-TPA) therapy. We aimed to assess the effect of prestroke antiplatelet on the SICH risk and functional outcome in Koreans treated with IV-TPA.

Methods

From a prospective stroke registry, we identified patients treated with IV-TPA between October 2009 and November 2014. Prestroke antiplatelet use was defined as taking antiplatelet within 7 days before the stroke onset. The primary outcome was SICH. Secondary outcomes were discharge modified Rankin Scale (mRS) score and in-hospital mortality.

Results

Of 1,715 patients treated with IV-TPA, 441 (25.7%) were on prestroke antiplatelet. Prestroke antiplatelet users versus non-users were more likely to be older, to have multiple vascular risk factors. Prestroke antiplatelet use was associated with an increased risk of SICH (5.9% vs. 3.0%; adjusted odds ratio [OR] 1.79 [1.05-3.04]). However, at discharge, the two groups did not differ in mRS distribution (adjusted OR 0.90 [0.72-1.14]), mRS 0-1 outcome (34.2% vs. 33.7%; adjusted OR 1.27 [0.94-1.72), mRS 0-2 outcome (52.4% vs. 52.9%; adjusted OR 1.21 [0.90-1.63]), and in-hospital mortality (6.1% vs. 4.2%; adjusted OR 1.19 [0.71-2.01]).

Conclusions

Despite an increased risk of SICH, prestroke antiplatelet users compared to non-users had comparable functional outcomes and in-hospital mortality with IV-TPA therapy. Our results support the use of IV-TPA in eligible patients taking antiplatelet therapy before their stroke onset.

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.

Abstract TP304: Use, Time Delay and Outcomes of the Drip-and-Ship Thrombolysis Paradigm for Patients With Acute Ischemic Stroke

Introduction: The utilization of drip-and-ship thrombolysis paradigm, clinical characteristics and outcomes of patients treated with the paradigm could vary with regional stroke care system.

Hypothesis: We hypothesized that clinical characteristics and functional outcomes of patients treated with drip-and-ship paradigm would be different from those of patients treated via direct visit.

Methods: From a multicenter stroke registry, we identified acute ischemic stroke patients treated with tPA who arrived hospital within 6 hours from the symptom onset. Functional outcomes at three months after the stroke were classified as favorable (modified Rankin Scale score [mRS] 0 to 1) or unfavorable (mRS 2-6). Using multivariable analysis, we compared the modified Rankin scale (mRS) score at 3 months and symptomatic intracranial hemorrhages (SICH) between patients treated with drip-and-ship paradigm and those treated via direct visit.

Results: Among 1,843 patients who met the eligible criteria, 244 patients (13.2%; 95% CI, 11.7-14.9) were treated using drip-and-ship paradigm. Patients treated with drip-and-ship paradigm had shorter onset to needle time compared with patients treated via direct visit (median[IQR], 110 minutes[79-150] vs 126 minutes[90-173], p<0.001). After multivariable analysis, patients treated with drip-and-ship paradigm had significantly greater risk of unfavorable functional outcome (mRS 2-6) at 3 months after the stroke compared with patients treated via direct visit (OR 2.15; 95% CI, 1.50-3.08; p < 0.001). SICH also occurred more frequently in patients treated with drip-and-ship paradigm (OR 1.78; 95% CI, 1.02-3.12; p =0.04). Of 1,843 patients, 509 patients (27.6%, 71 patients with drip-and-ship paradigm and 438 patients via direct visit) received subsequent endovascular recanalization therapy. The use of drip-and-ship paradigm caused approximately 105 minute delay in onset to groin puncture time compared with those treated via direct visit (305 minutes[260-345] vs 200 minutes[155-245], p<0.001).

Conclusions: Drip-and-ship thrombolysis paradigm was used in less than 15% of patients treated with tPA, and use of the paradigm caused a significant delay in onset to groin puncture time for endovascular therapy.

Abstract TP200: Family History and Risk of Recurrent Stroke

Background: 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 in ischemic stroke patients hospitalized within 7 day of onset. Collected information was categorized as follows: type of affected relatives with stroke (paternal, maternal, sibling, or two or more) and age of relative’s stroke onset in relative (< 50, 50∼59, 60∼69, and ≥ 70). Stroke recurrence was captured prospectively using predetermined protocol. Subgroup analysis was performed using categories based on patient’s age at the index stroke.

Results: Among 7,642 patients, 937 (12.3%) had history of stroke in their first-degree relatives, and 475(6.2%) experienced stroke recurrence (median follow-up, 365 days). In multivariate Cox proportional hazard models, overall family history was not associated with stroke recurrence (hazard ratio [HR], 1.06; 95% confidence interval [CI], 0.80-1.41). However, the details of family history, including relative’s age at stroke onset < 50 (HR, 2.15; 95% CI, 1.01-4.57) and stroke history in sibling (HR, 1.67; 95% CI, 1.09-2.57) were independently associated with stroke recurrence after adjusting for possible confounders. The associations seemed to be stronger in stroke of young adults (age, <55) compared to older stroke patients.

Conclusion: This study suggests that having relative with early onset stroke and sibling with history of stroke increase the risk of recurrent stroke and imply that additional precautions may be needed in such population.

Abstract WP76: Utility of Individual NIH Stroke Scale Items as a Predictor of Functional Outcomes in Acute Ischemic Stroke Patients Presenting With Mild Neurologic Deficits

Introduction: Predicting outcomes of acute stroke patients initially presenting with mild neurologic deficits is important in making decision for thrombolytic therapy. Previous researches with a small sample size have failed to find specific items of NIH Stroke Scale or clinical syndromes to be predictive of functional outcome.

Hypothesis: We hypothesized that certain items of the NIH Stroke Scale or their combinations would be independently associated with unfavorable functional outcome 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 initial NIH Stroke Scale scores ≤ 5. Functional outcomes at three months after the stroke were classified as favorable (modified Rankin Scale score [mRS] 0 to 1) or unfavorable (mRS 2-6). The individual NIH Stroke Scale items were dichotomized as absent (0) or present (≥1) for the analysis. The NIH Stroke Scale items and the total score were tested for predicting the outcomes in multivariable models adjusting for demographics and clinical characteristics. Area under the ROC curve (AUC) was used to assess the performance of multivariable models.

Results: Among 2,209 patients who met the eligible criteria, 588 patients (26.6%) exhibited unfavorable functional outcome (mRS 2-6) at three months. The most frequently present items were item 10 (dysarthria, 37.5%), item 4 (facial palsy, 21.1%), item 8 (sensory, 15.0%), and items indicating limb paralysis. Among 15 items of NIH Stroke Scale, all items except for item 8 (sensory) and item 11 (extinction) were significantly associated with unfavorable functional outcomes in bivariate analysis (P <0.05), and many of them remained significant in multivariable analyses. In multivariable analyses, the model including the total NIH Stroke Scale scores exhibited similar AUC (0.759; 95% CI, 0.740 -0.776; P=0.75 for pairwise comparison) compared to the model with all NIH Stroke Scale items (0.758; 0.739 - 0.775) in predicting functional outcomes after the stroke.

Conclusions: Simply using the total score was as effective as using all NIH Stroke Scale items in predicting outcomes of patients presented with mild stroke symptom.

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

Background and Purpose

Estimating age- and sex-specific population attributable risks (PARs) of major risk factors for stroke may be a useful strategy to identify risk factors for targeting preventive strategies.

Methods

For this case-control matched study, consecutive patients aged 18-90 years and admitted to nine nationwide hospitals with acute ischemic stroke between December 2008 and June 2010, were enrolled as cases. Controls, individually matched by age and sex, were chosen from the 4th Korean National Health & Nutrition Examination Survey (2008-2010). Based on odds ratios and prevalence, standardized according to the age and sex structure of the Korean population, PARs of major risk factors were estimated according to age (young, ≤ 45; middle-aged, 46-65; and elderly, ≥ 66 years) and sex subgroups.

Results

In 4,743 matched case-control sets, smoking (PAR, 45.1%) was the greatest contributing risk factor in young men, followed by hypertension (28.5%). In middle-aged men, the greatest contributing factors were smoking (37.4%), hypertension (22.7%), and diabetes (14.6%), whereas in women the greatest factors were hypertension (22.7%) and stroke history (10.6%). In the elderly, hypertension was the leading factor in men (23.7%) and women (23.4%). Other noticeable factors were stroke history (men, 19.7%; women, 17.3%) and diabetes (men, 12.5%; women, 15.1%). In young women, risk factors with a PAR greater than 10% were not found.

Conclusions

Smoking cessation in young people and hypertension and diabetes control in older people may be effective in reducing the burden of stroke on the population. In the elderly, secondary prevention could also be emphasized.

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

Background and Purpose

In a recent pooled analysis of randomized clinical trials (RCTs), intravenous tissue plasminogen activator (TPA) improves the outcome in patients aged ≥80 years. However, it is uncertain whether the findings are applicable to clinical practice in Asian populations.

Methods

From a multicenter stroke registry database of Korea, we identified patients with acute ischemic stroke who were aged ≥ 80 years. Using multivariable analysis and propensity score (PS)-matched analyses, we assessed the effectiveness and safety of intravenous TPA within 4.5 hours.

Results

Among 2,334 patients who met the eligible criteria, 236 were treated with intravenous TPA (mean age, 83±5; median NIHSS, 13 [IQR, 8-17]). At discharge, the TPA group compared to the no-TPA group had a favorable shift on the modified Rankin Scale (mRS) score (multivariable analysis, OR [95% CI], 1.51 [1.17-1.96], P=0.002; PS-matched analysis, 1.54 [1.17-2.04], P=0.002) and was more likely to achieve mRS 0-1 outcome (multivariable analysis, 2.00 [1.32-3.03], P=0.001; PS-matched analysis, 1.59 [1.04-2.42], P=0.032). TPA treatment was associated with an increased risk of symptomatic intracranial hemorrhage (multivariable analysis, 5.45 [2.80-10.59], P<0.001; PS-matched analysis, 4.52 [2.24-9.13], P<0.001), but did not increase the in-hospital mortality (multivariable analysis, 0.86 [0.50-1.48], P=0.58; PS-matched analysis, 0.88 [0.52-1.47], P=0.61).

Conclusions

In the setting of clinical practice, intravenous TPA within 4.5 hours improved the functional outcome despite an increased risk of symptomatic intracranial hemorrhage in very elderly Korean patients. The findings, consistent with those from pooled analysis of RCTs, strongly support the use of TPA for this population.