Long-term trends and affecting factors in the concentrations of criteria air pollutants in South Korea.

Here, we used a novel approach to analyze the trends in the concentrations of six national criteria air pollutants, carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), PM10, PM2.5, and surface ozone (O3), between 2001 and 2018, and the factors affecting the concentrations of CO and SO2 at the district level in South Korea (Korea) between 2011 and 2016. We considered four factors affecting the concentrations of CO and SO2: (1) concentration-to-emission ratio, (2) air pollutant-to-CO2 emission ratio, (3) carbon intensity, and (4) area-weighted energy supply. We found that the most influencing factors determining the concentrations of CO and SO2 in Korea were the air pollutant-to-CO2 emission ratio and the concentration-to-emission ratio. The annual mean concentrations of CO, SO2, PM10, PM2.5, and NO2 generally decreased, while O3 levels showed an increasing trend, over the last 18 years in Korea. We also found that NO2 concentration had strong positive and negative correlations with PM2.5 and O3 concentrations, respectively. However, the relationship between O3 and NO2 levels showed an inverted U shape under NO2 super-rich condition (e.g., > 55 ppb in Seoul), and the daily maximum 8-h values (MDA8O3) increased in proportion to the NO2 level under poor NO2 conditions (e.g., < 25 ppb in Seoul).

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.

Three-month modified Rankin Scale as a determinant of 5-year cumulative costs after ischemic stroke: An analysis of 11,136 patients in Korea.

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.

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.

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.

The Epidemiology of Fracture in Patients with Acute Ischemic Stroke in Korea.

BACKGROUND: Patients who survive an acute phase of stroke are at risk of falls and fractures afterwards. However, it is largely unknown how frequent fractures occur in the Asian stroke population. METHODS: Patients with acute (< 7 days) ischemic stroke who were hospitalized between January 2011 and November 2013 were identified from a prospective multicenter stroke registry in Korea, and were linked to the National Health Insurance Service claim database. The incidences of fractures were investigated during the first 4 years after index stroke. The cumulative incidence functions (CIFs) were estimated by the Gray's test for competing risk data. Fine and Gray model for competing risk data was applied for exploring risk factors of post-stroke fractures. RESULTS: Among a total of 11,522 patients, 1,616 fracture events were identified: 712 spine fractures, 397 hip fractures and 714 other fractures. The CIFs of any fractures were 2.63% at 6 months, 4.43% at 1 year, 8.09% at 2 years and 13.00% at 4 years. Those of spine/hip fractures were 1.11%/0.61%, 1.88%/1.03%, 3.28%/1.86% and 5.79%/3.15%, respectively. Age by a 10-year increment (hazard ratio [HR], 1.23; 95% confidence interval [CI], 1.17-1.30), women (HR, 1.74; 95% CI, 1.54-1.97), previous fracture (HR, 1.72; 95% CI, 1.54-1.92) and osteoporosis (HR, 1.44; 95% CI, 1.27-1.63) were independent risk factors of post-stroke fracture. CONCLUSION: The CIFs of fractures are about 8% at 2 years and 13% at 4 years after acute ischemic stroke in Korea. Older age, women, pre-stroke fracture and osteoporosis raised the risk of post-stroke fractures.

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

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

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

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

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

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

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

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

Effect of statin on progression of symptomatic basilar artery stenosis and subsequent ischemic stroke.

BACKGROUND AND OBJECTIVE: Symptomatic basilar artery stenosis (BAS) is associated with high risk of ischemic stroke recurrence. We aimed to investigate whether statin therapy might prevent the progression of symptomatic BAS and stroke recurrence. METHODS: We retrospectively analyzed the data of patients with acute ischemia with symptomatic BAS, which was assessed using magnetic resonance angiogram (MRA) imaging on admission day, and 1 year later (or the day of the clinical event). The clinical endpoints were recurrent ischemic stroke and its composites, transient ischemic attack, coronary disease, and vascular death. RESULTS: Of the 153 patients with symptomatic BAS, 114 (74.5%) were treated with a statin after experiencing a stroke. Statin therapy significantly prevented the progression of symptomatic BAS (7.0% vs 28.2%) and induced regression (22.8% vs 15.4%) compared to non-statin users (p = 0.002). There were 31 ischemic stroke incidences and 38 composite vascular events. Statin users showed significantly lower stroke recurrence (14.9% vs 35.9%, p = 0.05) and composite vascular events (17.5% vs 46.2%; odds ratio [OR], 0.29; 95% confidence interval [CI], 0.13-0.64) than those not using statins did. Recurrent stroke in the basilar territory and composite vascular events were more common in patients with progression of BAS than they were in other patients (OR, 5.16; 95% CI, 1.63-16.25 vs OR, 4.2; 95% CI, 1.56-11.34). CONCLUSION: Our study suggests that statin therapy may prevent the progression of symptomatic BAS and decrease the risk of subsequent ischemic stroke. Large randomized trials are needed to confirm this result.

Isolated intracranial fibromuscular dysplasia of the posterior cerebral artery.

Fibromuscular dysplasia (FMD) is a nonatherosclerotic, noninflammatory arterial disease that most commonly affects the renal and internal carotid arteries, but intracranial FMD is very rare. We report a patient with FMD involving the posterior cerebral arteries (PCAs). A 24year old female was presented with a 4day history of right homonymous hemianopsia with throbbing headache in the left temporo-occipital area. The brain magnetic resonance imaging (MRI) revealed an acute ischemic stroke in the left PCA territory, while the Time of Flight (TOF) magnetic resonance angiogram (MRA) showed segmental luminal irregularities in the left proximal PCA. The conventional angiogram revealed the "string of beads" appearance, a characteristic that is pathognomonic for FMD. The patient's inhospital clinical course was stable, while there was no recurrence of stroke. This is the second report of FMD of the PCA. Notwithstanding incredibly rare incidences of isolated intracranial FMD and nonspecific findings of MRA, such a pathophysiology should be considered as the cause for a stroke in young patients, especially those with no cardiovascular risk factor.

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.

Clinical Outcomes of Posterior Versus Anterior Circulation Infarction With Low National Institutes of Health Stroke Scale Scores.

BACKGROUND AND PURPOSE: We compared baseline characteristics and outcomes at 3 months between patients with minor anterior circulation infarction (ACI) versus minor posterior circulation infarction (PCI), including the influence of large vessel disease on outcomes. METHODS: This study is an analysis of a prospective multicenter registry database in South Korea. Eligibility criteria were patients with ischemic stroke admitted within 7 days of stroke onset, lesions in either anterior or posterior circulation, and National Institutes of Health Stroke Scale score of ≤4 at baseline. Patients were divided into 4 groups for further analysis: minor ACI with and without internal carotid artery/middle cerebral artery large vessel disease and minor PCI with and without vertebrobasilar large vessel disease. RESULTS: A total of 7178 patients (65.2±12.6 years) were analyzed in this study, and 2233 patients (31.1%) had disability (modified Rankin Scale score 2-6) at 3 months. Disability was 32.3% in minor PCI and 30.3% in minor ACI (P=0.07), and death was 1.3% and 1.5%, respectively (P=0.82). In a multivariable logistic regression analysis, minor PCI was significantly associated with disability at 3 months when compared with minor ACI (odds ratio, 1.23; 95% confidence interval, 1.09-1.37; P<0.001). In pairwise comparisons, minor PCI with vertebrobasilar large vessel disease was independently associated with disability at 3 months, compared with the other 3 groups. CONCLUSIONS: Our study showed that minor PCI exhibited more frequent disability at 3 months than minor ACI. Especially, the presence of vertebrobasilar large vessel disease in minor PCI had a substantially higher risk of disability. Our results suggest that minor PCI with vertebrobasilar large vessel disease could require more meticulous care and are important targets for further study.

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.

Extended Use of Hypothermia in Elderly Patients with Malignant Cerebral Edema as an Alternative to Hemicraniectomy.

BACKGROUND AND PURPOSE: The use of decompressive hemicraniectomy (DHC) for the treatment of malignant cerebral edema can decrease mortality rates. However, this benefit is not sufficient to justify its use in elderly patients. We investigated the effects of therapeutic hypothermia (TH) on safety, feasibility, and functional outcomes in elderly patients with malignant middle cerebral artery (MCA) infarcts. METHODS: Elderly patients 60 years of age and older with infarcts affecting more than two-thirds of the MCA territory were included. Patients who could not receive DHC were treated with TH. Hypothermia was started within 72 hours of symptom onset and was maintained for a minimum of 72 hours with a target temperature of 33°C. Modified Rankin Scale (mRS) scores at 3 months following treatment and complications of TH were used as functional outcomes. RESULTS: Eleven patients with a median age of 76 years and a median National Institutes of Health Stroke Scale score of 18 were treated with TH. The median time from symptom onset to initiation of TH was 30.3±23.0 hours and TH was maintained for a median of 76.7±57.1 hours. Shivering (100%) and electrolyte imbalance (82%) were frequent complications. Two patients died (18%). The mean mRS score 3 months following treatment was 4.9±0.8. CONCLUSIONS: Our results suggest that extended use of hypothermia is safe and feasible for elderly patients with large hemispheric infarctions. Hypothermia may be considered as a therapeutic alternative to DHC in elderly individuals. Further studies are required to validate our findings.

Different Antiplatelet Strategies in Patients With New Ischemic Stroke While Taking Aspirin.

BACKGROUND AND PURPOSE: Selecting among different antiplatelet strategies when patients experience a new ischemic stroke while taking aspirin is a common clinical challenge, currently addressed by a paucity of data. METHODS: This study is an analysis of a prospective multicenter stroke registry database from 14 hospitals in South Korea. Patients with acute noncardioembolic stroke, who were taking aspirin for prevention of ischemic events at the time of onset of stroke, were enrolled. Study subjects were divided into 3 groups according to the subsequent antiplatelet therapy strategy pursued; maintaining aspirin monotherapy (MA group), switching aspirin to nonaspirin antiplatelet agents (SA group), and adding another antiplatelet agent to aspirin (AA group). The primary study end point was the composite of stroke (ischemic and hemorrhagic), myocardial infarction, and vascular death up to 1 year after stroke onset. RESULTS: A total of 1172 patients were analyzed for this study. Antiplatelet strategies pursued in study patients were MA group in 212 (18.1%), SA group in 246 (21.0%), and AA group in 714 (60.9%). The Cox proportional hazards regression analysis showed that, compared with the MA group, there was a reduction in the composite vascular event primary end point in the SA group (hazard ratio, 0.50; 95% confidence interval, 0.27-0.92; P=0.03) and in the AA group (hazard ratio, 0.40; 95% confidence interval, 0.24-0.66; P<0.001). CONCLUSIONS: This study showed that, compared with maintaining aspirin, switching to or adding alternative antiplatelet agents may be better in preventing subsequent vascular events in patients who experienced a new ischemic stroke while taking aspirin.

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.