Etiologies, mechanisms, and risk factors of ischemic stroke in a young Asian adult cohort.

OBJECTIVES: Risk factors and causes of acute ischemic stroke (AIS) are more diverse in young adults, and traditional stroke classifications may be inadequate. Precise characterisation of AIS is important for guiding management and prognostication. We describe stroke subtypes, risk factors and etiologies for AIS in a young Asian adult population. MATERIALS AND METHODS: Young AIS patients aged 18-50 years admitted to two comprehensive stroke centres from 2020-2022 were included. Stroke etiologies and risk factors were adjudicated using Trial of Org 10172 in Acute Stroke Treatment (TOAST) and International Pediatric Stroke Study (IPSS) risk factors. Potential embolic sources (PES) were identified in a subgroup with embolic stroke of undetermined source (ESUS). These were compared across sex, ethnicities and age groups (18-39 years versus 40-50 years). RESULTS: A total of 276 AIS patients were included, with mean age 43±5.7 years and 70.3% male. Median duration of follow-up was 5 months (IQR: 3-10). The most common TOAST subtypes were small-vessel disease (32.6%) and undetermined etiology (24.6%). IPSS risk factors were identified in 95% of all patients and 90% with undetermined etiology. IPSS risk factors included atherosclerosis (59.5%), cardiac disorders (18.7%), prothrombotic states (12.4%) and arteriopathy (7.7%). In this cohort, 20.3% had ESUS, of which 73.2% had at least one PES, which increased to 84.2% in those <40 years old. CONCLUSIONS: Young adults have diverse risk factors and causes of AIS. IPSS risk factors and ESUS-PES construct are comprehensive classification systems that may better reflect heterogeneous risk factors and etiologies in young stroke patients.

Impact of atrial fibrillation on the treatment effect of bridging thrombolysis in ischemic stroke patients undergoing endovascular thrombectomy: a multicenter international cohort study.

BACKGROUND: The role of bridging intravenous thrombolysis (IVT) before endovascular thrombectomy (EVT) in the treatment of acute ischemic stroke (AIS) remains debatable. Atrial fibrillation (AF) associated strokes may be associated with reduced treatment effect from IVT. This study compares the effect of bridging IVT in AF and non-AF patients. METHODS: This retrospective cohort study comprised anterior circulation large vessel occlusion (LVO) AIS patients receiving EVT alone or bridging IVT plus EVT within 6 hours of symptom onset. Primary outcome was good functional outcome defined as modified Rankin Scale (mRS) 0-2 at 90 days. Secondary outcomes were successful reperfusion defined as expanded Thrombolysis In Cerebral Infarction (eTICI) grading ≥2b flow, symptomatic intracerebral hemorrhage (sICH), and in-hospital mortality. RESULTS: We included 705 patients (314 AF and 391 non-AF patients). The mean age was 68.6 years and 53.9% were male. The odds of good functional outcomes with bridging IVT was higher in the non-AF (adjusted odds ratio (aOR) 2.28, 95% CI 1.06 to 4.91, P=0.035) compared with the AF subgroups (aOR 1.89, 95% CI 0.89 to 4.01, P=0.097). However, this did not constitute a significant effect modification by the presence of AF on bridging IVT (interaction aOR 0.12, 95% CI -1.94 to 2.18, P=0.455). The rate of successful reperfusion, sICH, and mortality were similar between bridging IVT and EVT for both AF and non-AF patients. CONCLUSION: The presence of AF did not modify the treatment effect of bridging IVT. Further individual patient data meta-analysis of randomized trials may shed light on the comparative efficacy of bridging IVT in AF versus non-AF LVO strokes.

Autoimmune glial fibrillary acidic protein astrocytopathy masquerading as tuberculosis of the central nervous system: a case series.

We describe the case history of three patients with meningoencephalitis who were initially treated for presumed tuberculous meningoencephalitis before being diagnosed with autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy. We highlight the overlapping clinical features between autoimmune GFAP astrocytopathy and tuberculous meningoencephalitis and the challenges in early diagnosis, as both entities respond to an initial course of steroids accompanying antituberculous medications. Early evaluation of GFAP-immunoglobulin G in the cerebrospinal fluid of patients who present with aseptic meningoencephalitis could reveal autoimmune GFAP astrocytopathy, which responds favorably to immunotherapy.

Long-term outcomes of ischaemic stroke patients with diabetes in a multi-ethnic cohort in Singapore.

INTRODUCTION: Diabetes increases the risk of ischaemic stroke especially among Asians. This study aims to investigate contemporaneous long-term cardiovascular outcomes of ischaemic stroke patients with diabetes in a multi-ethnic Asian cohort. METHODS: Consecutive patients with ischaemic stroke were recruited from the National University Hospital, Singapore. Data on age, gender, ethnicity, risk factors (including diabetes status and body mass index [BMI]), stroke severity and mechanisms were collected. These patients were followed up until the day of the first cardiovascular event or July 2016, whichever was earlier. The primary endpoint was the time from enrolment to the first occurrence of a composite of cerebrovascular and coronary artery events. RESULTS: Between July 2011 and December 2013, 720 patients (mean age 60.6 years, 71% men, 43% with diabetes, median National Institute Health Stroke Severity scale 2) were enrolled and followed up. A total of 175 cardiovascular events occurred during a median follow-up of 3.25 years (6.90 events per 1,000 person-month), comprising 133 cerebrovascular and 42 coronary artery events. The adjusted hazard ratio of diabetes was 1.50 (95% CI 1.08-2.10). In a multivariable Cox proportional hazards model, Malay and Indian ethnicities, BMI <23kg/m2 and a prior diagnosis of diabetes were identified as independent predictors of recurrent cardiovascular events. CONCLUSION: Our study provides quantitative data on the event rates of ischaemic stroke patients with diabetes. These findings provide insights on stroke predictors in a multi-ethnic Asian population, which may have implications in the design of future interventional studies.

Temporal Trends and Patient Characteristics Associated With Drug Utilisation After First-Ever Stroke: Insights From Chronic Disease Registry Data in Singapore.

INTRODUCTION: Data on drug utilisation among stroke patients of Asian ethnicities are lacking. The objectives of the study were to examine the temporal trends and patient characteristics associated with prescription of thrombolytic, antithrombotic and statin medications among patients with first-ever stroke. MATERIALS AND METHODS: First-ever ischaemic and haemorrhagic stroke patients admitted to 2 Singapore tertiary hospitals between 2010‒2014 were included. Data were extracted from the National Healthcare Group Chronic Disease Management System. Association between drug utilisation and admission year, as well as characteristics associated with drug use, were explored using multivariable logistic regression. RESULTS: There was an increasing trend in the combined use of all 3 guideline medications in ischaemic stroke patients (P <0.001)-specifically thrombolytic agents (P <0.001), oral antithrombotics (P = 0.002) and statins (P = 0.003) at discharge. Among antithrombotics, the use of clopidogrel (P <0.001) and aspirin-clopidogrel (P <0.001) had increased, whereas prescription of dipyridamole (P <0.001) and aspirin-dipyridamole (P <0.001) had declined. For statins, the increase in atorvastatin prescription (P <0.001) was accompanied by decreasing use of simvastatin (P <0.001). Age, ethnicity and certain comorbidities (hyperlipidaemia, atrial fibrillation and chronic kidney disease) were associated with the combined use of all 3 guideline medications (P <0.05). In haemorrhagic stroke, prescription of statins at discharge were comparatively lower. CONCLUSION: This study reveals changes in prescription behaviour over time in a multiethnic Asian population with first-ever stroke. Patient characteristics including younger age, Malay ethnicity and certain comorbidities (i.e. hyperlipidaemia, atrial fibrillation) were associated with the combined use of all 3 guideline medications among ischaemic stroke patients.

Genotype-guided versus traditional clinical dosing of warfarin in patients of Asian ancestry: a randomized controlled trial.

BACKGROUND: Genotype-guided warfarin dosing has been shown in some randomized trials to improve anticoagulation outcomes in individuals of European ancestry, yet its utility in Asian patients remains unresolved. METHODS: An open-label, non-inferiority, 1:1 randomized trial was conducted at three academic hospitals in South East Asia, involving 322 ethnically diverse patients newly indicated for warfarin (NCT00700895). Clinical follow-up was 90 days. The primary efficacy measure was the number of dose titrations within the first 2 weeks of therapy, with a mean non-inferiority margin of 0.5 over the first 14 days of therapy. RESULTS: Among 322 randomized patients, 269 were evaluable for the primary endpoint. Compared with traditional dosing, the genotype-guided group required fewer dose titrations during the first 2 weeks (1.77 vs. 2.93, difference -1.16, 90% CI -1.48 to -0.84, P < 0.001 for both non-inferiority and superiority). The percentage of time within the therapeutic range over 3 months and median time to stable international normalized ratio (INR) did not differ between the genotype-guided and traditional dosing groups. The frequency of dose titrations (incidence rate ratio 0.76, 95% CI 0.67 to 0.86, P = 0.001), but not frequency of INR measurements, was lower at 1, 2, and 3 months in the genotype-guided group. The proportions of patients who experienced minor or major bleeding, recurrent venous thromboembolism, or out-of-range INR did not differ between both arms. For predicting maintenance doses, the pharmacogenetic algorithm achieved an R2 = 42.4% (P < 0.001) and mean percentage error of -7.4%. CONCLUSIONS: Among Asian adults commencing warfarin therapy, a pharmacogenetic algorithm meets criteria for both non-inferiority and superiority in reducing dose titrations compared with a traditional dosing approach, and performs well in prediction of actual maintenance doses. These findings imply that clinicians may consider applying a pharmacogenetic algorithm to personalize initial warfarin dosages in Asian patients. TRIAL REGISTRATION: ClinicalTrials.gov NCT00700895 . Registered on June 19, 2008.

Products of 5-lipoxygenase and myeloperoxidase activities are increased in young male cigarette smokers.

The significance of 5-lipoxygenase and myeloperoxidase activities has not been extensively studied among young male smokers. Leukotriene B(4), 20-hydroxy-leukotriene B(4), 20-carboxy-leukotriene B(4) and 3-chlorotyrosine were measured in plasma and urinary samples of young male smokers at 8 hours following cigarette abstinence and an hour after cigarette smoking. Leukotriene B(4) and 3-chlorotyrosine were determined in neutrophils isolated from these individuals. The levels of these markers were compared with those of age-matched controls. In vitro studies were performed to evaluate the production of leukotriene B(4) and 3-chlorotyrosine from human neutrophils following exposure to nicotine and cotinine. Thirty male smokers (mean age, 27.4 years) and 28 male non-smokers (mean age, 28.7 years) were studied. Plasma levels of leukotriene B(4), 20-carboxy-leukotriene B(4) and 3-chlorotyrosine were higher in smokers than in non-smokers; leukotriene B(4) and 20-carboxy-leukotriene B(4) levels increased further an hour after cigarette smoking. Peripheral neutrophils isolated from smokers showed greater expressions of myeloperoxidase and 5-lipoxygenase activities compared with non-smokers, while plasma leukotriene B(4) and 3-chlorotyrosine were correlated significantly with high-sensitivity C-reactive protein and plasma nicotine concentrations. Exposure of human neutrophils to nicotine and cotinine resulted in a higher production of leukotriene B(4) and 3-chlorotyrosine. To conclude, leukotriene B(4) and 3-chlorotyrosine levels are increased in young male cigarette smokers. These results suggest that cigarette smoking aggravates neutrophil-mediated inflammation by modulating the activities of myeloperoxidase and 5-lipoxygenase pathways.

Markers of oxidative damage are not elevated in otherwise healthy individuals with the metabolic syndrome.

OBJECTIVE: The role of oxidative damage in the pathogenesis of metabolic syndrome is poorly understood. RESEARCH DESIGN AND METHODS: A detailed cross-sectional study was performed to assess the relationship between lipid oxidation products, gamma-glutamyltransferase, high-sensitivity C-reactive protein (hs-CRP), and phospholipase activities with respect to the metabolic status in a cohort of otherwise healthy individuals. RESULTS: A total of 179 individuals (87 men and 92 women) aged 43 +/- 14 years (mean +/- SD) participated in this study. There were no differences in the levels of plasma F(2)-isoprostanes, hydroxyeicosatetraenoic acids, cholesterol oxidation products, and phospholipase activities in individuals with features of metabolic syndrome. In multivariate analyses, serum hs-CRP was a consistent independent predictor of metabolic syndrome. CONCLUSIONS: Minimal changes were observed in multiple markers of oxidative damage in a well-characterized cohort of individuals with features of metabolic syndrome.