Stroke Measures Analysis of pRognostic Testing - Mortality (SMART-M) nomogram predicts long-term mortality after ischaemic stroke.

BACKGROUND: Predicting long-term mortality is essential for understanding prognosis and guiding treatment decisions in patients with ischemic stroke. Therefore, this study aimed to develop and validate the method for predicting 1-year and 5-year mortality after ischemic stroke. METHODS: We utilized data from the linked dataset comprising the administrative claims database of the Health Insurance Review and Assessment Service and the Clinical Research Center for Stroke registry data for patients with acute stroke within 7 days of onset. The outcome was all-cause mortality following ischemic stroke. Clinical variables linked to long-term mortality following ischemic stroke were determined. A nomogram was constructed based on the Cox's regression analysis. The performance of the risk prediction model was evaluated using the Harrell's C index. RESULTS: This study included 42,207 ischemic stroke patients, with a mean age of 66.6 years and 59.2% being male. The patients were randomly divided into training (n=29,916) and validation (n=12,291) groups. Variables correlated with long-term mortality in patients with ischemic stroke, including age, sex, body mass index, stroke severity, stroke mechanisms, onset-to-door time, pre-stroke dependency, history of stroke, diabetes mellitus, hypertension, coronary artery disease, chronic kidney disease, cancer, smoking, fasting glucose level, previous statin therapy, thrombolytic therapy such as intravenous thrombolysis and endovascular recanalization therapy, medications, and discharge modified Rankiin Scale were identified as predictors. We developed a predictive system named Stroke Measures Analysis of pRognostic Testing - Mortality (SMART-M) by constructing a nomogram using the identified features. The C-statistics of the nomogram in the developing and validation groups were 0.806 (95% confidence interval [CI], 0.802-0.812) and 0.803 (95% CI, 0.795-0.811), respectively. CONCLUSIONS: The SMART-M method demonstrated good performance in predicting long-term mortality in ischemic stroke patients. This method may help physicians and family members understand the long-term outcomes and guide the appropriate decision-making process.

Automated segmentation of MRI white matter hyperintensities in 8,421 patients with acute ischemic stroke.

BACKGROUND AND PURPOSE: To date, only a few small studies have attempted deep learning-based automatic segmentation of white matter hyperintensity (WMH) lesions in patients with cerebral infarction, which is complicated because stroke-related lesions can obscure WMH borders. We developed and validated deep learning algorithms to segment WMH lesions accurately in patients with cerebral infarction, using multisite datasets involving 8,421 patients with acute ischemic stroke. MATERIALS AND METHODS: We included 8,421 stroke patients from 9 centers in Korea. 2D UNet and SE-Unet models were trained using 2,408 FLAIR MRI from 3 hospitals and validated using 6,013 FLAIR MRIs from 6 hospitals. WMH segmentation performance was assessed by calculating DSC, correlation coefficient, and concordance correlation coefficient compared to a human-segmented gold standard. In addition, we obtained an uncertainty index that represents overall ambiguity in the voxel classification for WMH segmentation in each patient based on the Kullback-Leibler divergence. RESULTS: In the training dataset, the mean age was 67.4±13.0 years and 60.4% were men. The mean (95% CI) DSCs for Unet in internal testing and external validation were respectively 0.659 (0.649-0.669) and 0.710 (0.707-0.714), which were slightly lower than the reliability between humans (DSC=0.744; 95% CI=0.738-0.751; P=.031). Compared with the Unet, the SE-Unet demonstrated better performance, achieving a mean DSC of 0.675 (0.666-0.685; P<.001) in the internal testing and 0.722 (0.719-0.726; P<.001) in the external validation; moreover, it achieved high DSC values (ranging from 0.672 to 0.744) across multiple validation datasets. We observed a significant correlation between WMH volumes that were segmented automatically and manually for the Unet (r=0.917, P<.0001) and even stronger for the SE-Unet (r=0.933, P<.0001). The SE-Unet also attained a high concordance correlation coefficient (ranging from 0.841 to 0.956) in external test datasets. In addition, the uncertainty indices in the majority of patients (86%) in the external datasets were below 0.35, with an average DSC of 0.744 in these patients. CONCLUSIONS: We developed and validated deep learning algorithms to segment WMH in patients with acute cerebral infarction using the largest-ever MRI datasets. In addition, we showed that the uncertainty index can be used to identify cases where automatic WMH segmentation is less accurate and requires human review. ABBREVIATIONS: WMH = white matter hyperintensity; CNN = convolutional neural networks; SE = squeeze-and-excitation; KL = Kullback-Leibler; ReLU = rectified linear unit; LKW = last known well; mRS = modified Rankin Scale; NIHSS = National Institute of Health Stroke Scale; LAA = large artery atherosclerosis; SVO = small vessel occlusion; CE = cardioembolism.

Temporal trends of sex differences in acute reperfusion therapy and early outcomes of acute ischemic stroke in South Korea: 10-year analysis of the nationwide stroke registry.

BACKGROUND: Sex differences in stroke outcomes are notable, with women experiencing higher incidence rates, greater disability-adjusted life years, and poorer recovery compared to men, even after adjusting for age and comorbidities. Despite the disproportionate burden in women, studies have reported that women are less likely to receive appropriate stroke treatment than men. AIM: This study investigated temporal trends of sex differences in acute reperfusion therapy and early outcomes in patients with acute ischemic stroke over 10 years in South Korea. METHODS: A retrospective analysis of Korean Stroke Registry included patients with acute ischemic stroke from 2012 to 2021. The study outcomes were the temporal trends of acute reperfusion therapy and early outcomes over 10 years in men and women, respectively. In addition, this study analyzed the temporal trends of sex differences in these parameters during the same period. Early outcomes include the proportions of favorable functional outcomes at discharge, discharge patterns, and in-hospital mortality. RESULTS: A total of 93,692 patients (68.4 years, 40.1% women) with acute ischemic stroke were finally enrolled. Women had a higher age at stroke onset, a higher prevalence of atrial fibrillation, and more severe strokes than men. Women had lower proportion of favorable functional outcomes at discharge and higher proportion of in-hospital mortality compared to men each year. The proportion of patients who received intravenous thrombolysis was lower or similar in women compared to men in most years, and the proportion of patients who received endovascular thrombectomy did not significantly differ between sexes annually. Sex differences in acute reperfusion therapy remained unchanged over 10 years. CONCLUSION: Women have received acute reperfusion therapy at similar or lower rates than men and experienced poorer outcomes, despite having more stroke risk factors and often more severe strokes.

Trends in Dual Antiplatelet Therapy of Aspirin and Clopidogrel and Outcomes in Ischemic Stroke Patients Noneligible for POINT/CHANCE Trial Treatment.

BACKGROUND: Recent clinical trials established the benefit of dual antiplatelet therapy with aspirin and clopidogrel (DAPT-AC) in early-presenting patients with minor ischemic stroke. However, the impact of these trials over time on the use and outcomes of DAPT-AC among the patients with nonminor or late-presenting stroke who do not meet the eligibility criteria of these trials has not been delineated. METHODS AND RESULTS: In a multicenter stroke registry, this study examined yearly changes from April 2008 to August 2022 in DAPT-AC use for stroke patients ineligible for CHANCE/POINT (Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events/Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke) clinical trials due to National Institutes of Health Stroke Scale >4 or late arrival beyond 24 hours of onset. A total of 32 118 patients (age, 68.1±13.1 years; male, 58.5%) with National Institutes of Health Stroke Scale of 4 (interquartile range, 1-7) were analyzed. In 2008, DAPT-AC was used in 33.0%, other antiplatelets in 62.7%, and no antiplatelet in 4.3%. The frequency of DAPT-AC was relatively unchanged through 2013, when the CHANCE trial was published, and then increased steadily, reaching 78% in 2022, while other antiplatelets decreased to 17.8% in 2022 (Ptrend<0.001). From 2011 to 2022, clinical outcomes nonsignificantly improved, with an average relative risk reduction of 2%/y for the composite of stroke, myocardial infarction, and all-cause mortality, both among patients treated with DAPT-AC and patients treated with other antiplatelets. CONCLUSIONS: Use of DAPT-AC in stroke patients with stroke ineligible for recent DAPT clinical trials increased markedly and steadily after CHANCE publication in 2013, reaching deployment in nearly 4 of every 5 patients by 2022. The secondary prevention in patients with ischemic stroke seems to be gradually improving, possibly due to the enhancement of risk factor control.

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

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

Optimal use of antithrombotic agents in recent small subcortical strokes accompanied by atrial fibrillation.

BACKGROUND: This study aimed to evaluate the efficacy and safety of anticoagulants (AC) and antiplatelets (APT) in patients with recent small subcortical infarctions (RSSI) and atrial fibrillation (AF). METHODS: We utilized a prospective multicenter stroke registry database to identify patients with RSSI with a concurrent diagnosis of AF. Propensity score matching analysis was used to balance baseline differences among the AC-only, APT-only, and their combination groups. The main outcomes of interest were time to occurrence of minor and major bleeding, stroke recurrence, and all-cause mortality. Adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for each outcome were calculated using the multivariable Cox proportional hazard regression analysis. RESULTS: Of the 404 eligible patients, 28.2% received APT only, 53.0% received AC only, and 18.9% received a combination of both. Notable differences were observed between these groups in terms of the 1-year stroke recurrence (APT, 32.5%; AC, 5.6%; APT + AC, 9.2%) and all-cause mortality (APT, 21.9%; AC, 6.1%; APT + AC, 14.5%), whereas the rates of bleeding events were comparable. The multivariable analysis indicated a significant association of AC alone with reduced risks of severe bleeding, stroke recurrence, and all-cause mortality compared with APT alone (aHR 0.64, 95% CI 0.41-0.98; aHR 0.11, 95% CI 0.06-0.22; aHR 0.22, 95% CI 0.11-0.44, respectively). The combination group showed a reduced risk of stroke recurrence compared to APT alone (aHR 0.19, 95% CI 0.08-0.46). These findings remained consistent with the propensity score-matched analysis. CONCLUSION: AC showed better clinical outcomes than APT in patients with RSSI and AF. Additionally, combination therapy with AC and APT was associated with a lower risk of stroke recurrence than APT alone.

The impact of statin treatment duration on the risk of new-onset diabetes mellitus and recurrent vascular events in ischemic stroke patients: a linked data analysis.

INTRODUCTION: Although statin therapy reduces cardiovascular events, statin use is associated with the risk of new-onset diabetes mellitus (NODM). Using a linked dataset, we evaluated the effect of statin treatment on vascular outcomes and NODM development in patients with ischemic stroke. METHODS: From the dataset, we identified 20,250 patients with acute ischemic stroke who had neither a prior history of DM nor a previous history of statin use before the index stroke. Patients were divided into statin users and non-users. The outcomes were NODM and vascular outcomes, including recurrent ischemic stroke and acute myocardial infarction (AMI). RESULTS: Of the 20,250 patients, 13,706 (67.7%) received statin treatment after the index stroke. For the risk of NODM, a time-response relationship was observed between the use of statins and NODM; a longer post-stroke follow-up duration substantially increased the risk of NODM. Among those with ischemic stroke exceeding 3 years, statin users had an approximately 1.7-fold greater risk of NODM than statin non-users. Statin therapy significantly reduced the risk of recurrent ischemic stroke by 54% (HR 0.46, 95% CI, 0.43-0.50, P < 0.001) across all stroke subtypes. CONCLUSION: Statin therapy following ischemic stroke increased the occurrence of NODM in patients over a period of 3 years. Despite the increased risk of NODM, statin therapy shows a beneficial effect in reducing major cardiovascular events such as recurrent ischemic stroke and AMI in patients with ischemic stroke.

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.

Differential impacts of admission LDL-cholesterol on early vascular outcomes by ischemic stroke subtypes.

BACKGROUND: Because ischemic stroke is heterogeneous, the associations between low-density lipoprotein (LDL)-cholesterol levels and early vascular outcomes might be different according to the stroke subtype in acute ischemic stroke patients. METHODS: This study was an analysis of a prospective, multicenter, stroke registry. Acute ischemic stroke patients previously not treated with statins were included. Admission LDL-cholesterol levels were divided into 7 groups at 20 mg/dl intervals for comparison. The primary early vascular outcome was a composite of stroke, myocardial infarction (MI) and all-cause mortality within 3 months. RESULTS: A total of 38,531 patients (age, 68.5 ± 12.8 yrs; male, 59.6%) were analyzed for this study. The 3-month cumulative incidences of the composite of stroke, MI, and all-cause mortality significantly differed among the LDL-cholesterol level groups, with the highest event rate (11.11%) in the lowest LDL-cholesterol group (<70 mg/dl). After adjustment, the U-shaped associations of LDL-cholesterol levels with primary outcome and all-cause mortality were observed. For the stroke subtypes, there were substantial interactions between the LDL-cholesterol groups and stroke subtype and all-cause mortality (Pinteraction=0.07). Different patterns, with higher risks of all-cause mortality in the lower LDL-cholesterol in the large artery atherosclerosis subtype (adjusted hazard ratio [aHR] 1.29, 95% confidence interval [CI] 0.98-1.69), but in the higher LDL-cholesterol in the cardioembolism subtype (aHR 1.71 95% CI [1.28-2.29]), were observed among stroke subtypes. CONCLUSION: We found that there were differential associations of admission LDL-cholesterol levels with all-cause mortality within 3 months among stroke subtypes. These results suggest that admission LDL-cholesterol and early vascular outcomes had complex relationships in patients with ischemic stroke according to the stroke subtypes.

Effect of pre-stroke antiplatelet use on stroke outcomes in acute small vessel occlusion stroke with moderate to severe white matter burden.

BACKGROUND: Cerebral small vessel disease is characterized by white matter hyperintensities (WMH) and acute small vessel occlusion (SVO) stroke. We investigated the effect of prior antiplatelet use (APU) on stroke outcome in 1151 patients with acute SVO stroke patients and moderate to severe WMH. METHODS: Using a multicenter database, this retrospective study used quantitative WMH volume measurements and propensity score matching (PSM) for comparisons between patients with prior APU and without APU. Primary outcomes were stroke progression and poor functional outcome (modified Rankin Scale>2) at 3 months. Logistic regression analyses assessed associations between prior APU, WMH burden, and stroke outcomes. RESULTS: Stroke progression was lower in the prior APU group in both the total cohort (14.8% vs. 6.9%, p < 0.001) and the PSM cohort (16.3% vs. 6.9%, p < 0.001). The proportion of poor functional outcomes at 3 months was not significantly different in the total cohort, but the PSM cohort showed a lower proportion in the prior APU group (30.8% vs. 20.2%, p = 0.002). Logistic regression analysis confirmed that prior APU was associated with a reduced risk of stroke progression (OR, 0.39; 95% CI, 0.22-0.70; p = 0.001) and poor functional outcome at 3 months (OR, 0.37; 95% CI, 0.23-0.59; p < 0.001). CONCLUSION: Prior APU is associated with reduced stroke progression and improved functional outcome at 3 months in acute SVO stroke patients with moderate to severe WMH. Early treatment of WMH and acute SVO stroke may have potential benefits in improving stroke outcomes.

Association of high-estimated glomerular filtration rate with the severity of ischemic stroke during non-vitamin K antagonist oral anticoagulants therapy: a nationwide cohort study.

Aim: While the relationship between impaired kidney function and non-vitamin K antagonist oral anticoagulants (NOACs) is well established, there is limited research exploring the association between an elevated estimated glomerular filtration rate (eGFR) and the efficacy of NOACs, especially concerning the outcomes of acute ischemic stroke (AIS). This study aimed to examine the association between higher-than-normal eGFR and the severity of AIS during the use of NOACs using a nationwide multicenter stroke registry in Korea. Material and methods: This study utilized data from the Korean Stroke Registry (KSR) database, examining information from 2,379 patients with AIS, who had atrial fibrillation (AF) and a history of utilizing NOACs prior to hospitalization due to incident stroke occurring between 2016 and 2021. Patients with a history involving two or more types of anticoagulants or one or more forms of antiplatelet agents were excluded. Baseline characteristics, medical history, medication usage, CHADS2-VASc score, and the anticoagulation and risk factors in atrial fibrillation (ATRIA) score were evaluated. Renal function was assessed using eGFR levels and calculated with the Cockcroft-Gault equation. The severity of stroke was measured by the National Institutes of Health Stroke Scale as an outcome. For sensitivity analysis, further evaluation was performed using eGFR levels according to the modification of diet in renal disease (MDRD) study equation. Results: The mean age of subjects was 76.1 ± 8.9 years. The moderate-to-severe stroke severity group exhibited an elevation in creatinine levels. The eGFR of 60 to 89 mL/min/1.73 m2 group was associated with a decreased risk of moderate-to-severe stroke severity [hazard ratio (HR)] (0.77, 95% confidence interval (CI) [0.61, 0.98], p = 0.031) compared to the eGFR≥90 mL/min/1.73 m2 group. An increment of 10 units in eGFR was marginally associated with an increased risk of moderate-to-severe stroke severity (HR: 1.03, 95% CI [1.00, 1.07], p = 0.054). Conclusion: The study revealed that individuals with eGFR ≥ 90 mL/min/1.73 m2 had an association linked to an increased risk of moderate-to-severe stroke severity. Our study suggests that patients taking NOACs with higher-than-normal eGFR levels may have an increased severity of AIS.