Frailty and Early Mortality following Intracerebral Hemorrhage.

INTRODUCTION: Prognostication in spontaneous intracerebral hemorrhage (ICH) is vital for effective clinical decision-making but can be challenging. Frailty - the loss of physiological reserve to withstand stressor events - is a risk factor for poor outcomes after ischemic stroke, yet its role in ICH remains poorly understood. This study investigates whether frailty is independently associated with 28-day mortality following ICH. METHODS: A validated pre-stroke frailty index (FI) was measured for individuals presenting with ICH, yielding a FI of 0-1. The relationship between 28-day mortality and FI was assessed using multivariable logistic regression adjusting for age, neurosurgical intervention, National Institutes of Health Stroke Scale (NIHSS), Glasgow Coma Score (GCS), and ICH volume. RESULTS: Forty (34.5%) of 116 individuals with ICH died within 28 days. Frailty was independently associated with 28-day mortality, with each 0.1 increase in FI independently associated with an adjusted odds ratio of death of 1.09 (95% CI: 1.01-1.18). ICH volume was also independently associated with mortality (aOR 1.04, 95% CI: 1.02-1.06 per 10 mL increase). In contrast, age and neurosurgical intervention were not independently associated with mortality in our cohort. CONCLUSION: Higher pre-stroke frailty is independently associated with early mortality following spontaneous ICH, indicating the potential of frailty evaluation to inform prognostication and clinical decision-making.

18F-NaF uptake on vascular PET imaging in symptomatic versus asymptomatic atherosclerotic disease: A meta-analysis.

INTRODUCTION: 18F-sodium fluoride (NaF) positron-emission tomography (PET) is increasingly being used to measure microcalcification in atherosclerotic disease in vivo. Correlations have been drawn between sodium fluoride uptake and the presence of high-risk plaque features, as well as its association with clinical atherosclerotic sequelae. The aim of this study was to perform a meta-analysis of NaF uptake on PET imaging and its relation to symptomatic and asymptomatic disease. METHODS: A systematic review was performed according to PRISMA guidelines, via searching the Ovid MEDLINE, Ovid Embase, Cochrane Library, PubMed, Scopus, and Web of Science Core Collection databases up to May 2024. The search strategy included the terms 'NaF', 'PET', and 'plaque', and all studies with data regarding the degree of microcalcification, as measured by 18F-NaF uptake in symptomatic and asymptomatic atherosclerotic plaques, were included. Analysis involved calculating mean differences between uptake values and comparison using a random-effects model. RESULTS: A total of 16 articles, involving 423 participants, were included in the meta-analysis (10 carotid artery studies, five coronary artery studies, and one in peripheral vascular disease). Comparing 18F-NaF uptake in symptomatic versus asymptomatic atherosclerotic plaques, a mean difference of 0.43 (95% CI 0.29 to 0.57; p < 0.0001, I2 = 65%) was noted in studies comparing symptomatic and asymptomatic plaques in the same participant, with a significant difference in effect based on arterial territory studied (χ2 = 12.68, p = 0.0018). In studies of participants with and without symptomatic disease, there was no significant difference between symptomatic and asymptomatic plaques (mean difference 0.27, 95% CI -0.26 to 0.80, p = 0.28, I2 = 85%). CONCLUSIONS: PET imaging using 18F-NaF can detect differences in microcalcification between symptomatic and asymptomatic atherosclerotic plaques within, but not between, individuals, and thus, is a marker of symptomatic disease. The standardization of 18F-NaF PET imaging protocols, and its future use as a risk stratification tool or outcome measure, requires further study. (PROSPERO Registration ID: CRD42023451363).

Clinical frailty independently predicts early mortality after ischaemic stroke.

BACKGROUND: Clinical frailty is an important syndrome for clinical care and research, independently predicting mortality and rates of institutionalisation in a range of medical conditions. However, there has been little research into the role of frailty in stroke. OBJECTIVE: This study investigates the effect of frailty on 28-day mortality following ischaemic stroke and outcomes following stroke thrombolysis. METHODS: Frailty was measured using the Clinical Frailty Scale (CFS) for all ischaemic stroke admissions aged ≥75 years. Stroke severity was measured using the National Institutes of Health Stroke Scale (NIHSS). 28-day mortality and clinical outcomes were collected retrospectively. Analysis included both dichotomised measures of frailty (non-frail: CFS 1-4, frail: 5-8) and CFS as a continuous ordinal scale. RESULTS: In 433 individuals with ischaemic stroke, 28-day mortality was higher in frail versus non-frail individuals (39 (16.7%) versus 10 (5%), P < 0.01). On multivariable analysis, a one-point increase in CFS was independently associated with 28-day mortality (OR 1.03 (1.01-1.05)). In 63 thrombolysed individuals, median NIHSS reduced significantly in non-frail individuals (12.5 (interquartile range (IQR) 9.25) to 5 (IQR 10.5), P < 0.01) but not in frail individuals (15 (IQR 11.5) to 16 (IQR 16.5), P = 0.23). On multivariable analysis, a one-point increase in CFS was independently associated with a one-point reduction in post-thrombolysis NIHSS improvement (coefficient 1.07, P = 0.03). CONCLUSION: Clinical frailty is independently associated with 28-day mortality after ischaemic stroke and appears independently associated with attenuated improvement in NIHSS following stroke thrombolysis. Further research is needed to elucidate the underlying mechanisms and how frailty may be utilised in clinical decision-making.

Impact of stroke on outcomes following cardiac surgery: Propensity matched analysis.

BACKGROUND: Stroke remains a devastating complication of cardiac surgery. The aim of this study was to characterize the incidence of stroke and analyze the impact of stroke on patient outcomes and survival. METHODS: A retrospective analysis was performed of patients with a computed tomography-confirmed stroke diagnosis between 1 January 2015 and 31 March 2019 at a single center. 2:1 propensity matching was performed to identify a control population. RESULTS: Over the period 165 patients suffered a stroke (1.99%), with an incidence ranging from 0.85% for coronary artery bypass grafting to 8.14% for aortic surgery. The mean age was 70.3 years and 58.8% were male. 18% had experienced a previous stroke or transient ischemic attack. Compared to the comparison group, patients experiencing postoperative stroke had a significantly prolonged period of intensive care unit admission (8.0 vs 1.1 days P < .001) and hospital length of stay (12.94 vs 8.0 days P < .001). Patient survival was also inferior. In-hospital mortality was almost three times as high (17.0% vs 5.9%; P < .001). Longer-term survival was also inferior to Kaplan-Meier estimation (P < .001). The 1-year and 3-year survival were 61.5% and 53.8% respectively compared to 89.4% and 86.1% for the comparison group. CONCLUSION: Perioperative stroke is a devastating complication following cardiac surgery. Perioperative stroke is associated with significantly inferior outcomes in terms of both morbidity and mortality. Notably a 28% reduction in 1-year survival. Efforts should focus on identifying strategies aimed at reducing the incidence, morbidity, and mortality of perioperative stroke following cardiac surgery.

Imaging Atherosclerosis.

Advances in atherosclerosis imaging technology and research have provided a range of diagnostic tools to characterize high-risk plaque in vivo; however, these important vascular imaging methods additionally promise great scientific and translational applications beyond this quest. When combined with conventional anatomic- and hemodynamic-based assessments of disease severity, cross-sectional multimodal imaging incorporating molecular probes and other novel noninvasive techniques can add detailed interrogation of plaque composition, activity, and overall disease burden. In the catheterization laboratory, intravascular imaging provides unparalleled access to the world beneath the plaque surface, allowing tissue characterization and measurement of cap thickness with micrometer spatial resolution. Atherosclerosis imaging captures key data that reveal snapshots into underlying biology, which can test our understanding of fundamental research questions and shape our approach toward patient management. Imaging can also be used to quantify response to therapeutic interventions and ultimately help predict cardiovascular risk. Although there are undeniable barriers to clinical translation, many of these hold-ups might soon be surpassed by rapidly evolving innovations to improve image acquisition, coregistration, motion correction, and reduce radiation exposure. This article provides a comprehensive review of current and experimental atherosclerosis imaging methods and their uses in research and potential for translation to the clinic.

18F-FDG Uptake on PET/CT in Symptomatic versus Asymptomatic Carotid Disease: a Meta-Analysis.

INTRODUCTION: The role of positron emission tomography (PET)/computed tomography (CT) in the determination of inflammation in arterial disease is not well defined. This can provide information about arterial wall inflammation in atherosclerotic disease, and may give insight into plaque stability. The aim of this review was to perform a meta-analysis of PET/CT with 18F-FDG (fluorodeoxyglucose) uptake in symptomatic and asymptomatic carotid artery disease. METHODS: This was a systematic review, following PRISMA guidelines, which interrogated the MEDLINE database from January 2001 to May 2017. The search combined the terms, "inflammation", "FDG", and "stroke". The search criteria included all types of studies, with a primary outcome of the degree of arterial vascular inflammation determined by 18F-FDG uptake. Analysis involved an inverse weighted variance estimate of pooled data, using a random effects model. RESULTS: A total of 14 articles (539 patients) were included in the meta-analysis. Comparing carotid artery 18F-FDG uptake in symptomatic versus asymptomatic disease yielded a standard mean difference of 0.94 (95% CI 0.58-1.130; p < .0001; I2 = 65%). CONCLUSIONS: PET/CT using 18F-FDG can demonstrate carotid plaque inflammation, and is a marker of symptomatic disease. Further studies are required to understand the clinical implication of PET/CT as a risk prediction tool.

Molecular imaging of atherosclerosis with integrated PET imaging.

Atherosclerotic diseases account for nearly half of all deaths and are leading causes of adult disability. Our understanding of how atherosclerosis leads to cardiovascular disease events has evolved: from a concept of progressive luminal narrowing, to that of sudden rupture and thrombosis of biologically active atheroma. In concert with this conceptual shift, contemporary imaging techniques now allow imaging of biological processes that associate with plaque instability: active calcification and plaque inflammation. This review focuses on opportunities provided by positron emission tomography/computed tomography, to identify these high-risk biological features of atherosclerosis.

PET Imaging of Atherosclerotic Disease: Advancing Plaque Assessment from Anatomy to Pathophysiology.

Atherosclerosis is a leading cause of morbidity and mortality. It is now widely recognized that the disease is more than simply a flow-limiting process and that the atheromatous plaque represents a nidus for inflammation with a consequent risk of plaque rupture and atherothrombosis, leading to myocardial infarction or stroke. However, widely used conventional clinical imaging techniques remain anatomically focused, assessing only the degree of arterial stenosis caused by plaques. Positron emission tomography (PET) has allowed the metabolic processes within the plaque to be detected and quantified directly. The increasing armory of radiotracers has facilitated the imaging of distinct metabolic aspects of atherogenesis and plaque destabilization, including macrophage-mediated inflammatory change, hypoxia, and microcalcification. This imaging modality has not only furthered our understanding of the disease process in vivo with new insights into mechanisms but has also been utilized as a non-invasive endpoint measure in the development of novel treatments for atherosclerotic disease. This review provides grounding in the principles of PET imaging of atherosclerosis, the radioligands in use and in development, its research and clinical applications, and future developments for the field.

Imaging unstable plaque.

Recent advances in imaging technology have enabled us to utilise a range of diagnostic approaches to better characterise high-risk atherosclerotic plaque. The aim of this article is to review current and emerging techniques used to detect and quantify unstable plaque in the context of large and small arterial systems and will focus on both invasive and non-invasive imaging techniques. While the diagnosis of clinically relevant atherosclerosis still relies heavily on anatomical assessment of arterial luminal stenosis, evolving multimodal cross-sectional imaging techniques that encompass novel molecular probes can provide added information with regard to plaque composition and overall disease burden. Novel molecular probes currently being developed to track precursors of plaque rupture such as inflammation, micro-calcification, hypoxia and neoangiogenesis are likely to have translational applications beyond diagnostics and have the potential to play a part in quantifying early responses to therapeutic interventions and more accurate cardiovascular risk stratification.

Developing a pragmatic medical curriculum for the 21st century.

Medical education within a hospital setting presents both opportunities and challenges. The range of educational experiences on offer is often vast, though may be lost in the overworked and convoluted environment of a tertiary centre. As our learners are increasingly consumed by the literal and figurative labyrinths of hospitals and electronic learning logs, are we failing to train them in the skills they need to deliver 21st century health care? In response to this problem we propose a FARCICAL approach: Fostering A Relevant Curriculum that Is Closer to Actual Life.

Carotid atherosclerotic plaque microcalcification is independently associated with recurrent neurovascular events: A pilot study.

BACKGROUND: Microcalcification and macrocalcification are critical processes in atherosclerotic plaque progression, though how these processes relate to the risk of stroke recurrence in symptomatic carotid atherosclerosis is poorly understood. METHODS: We performed a post hoc analysis of data from the ICARUSS (Imaging Carotid Atherosclerosis in the Recovery and Understanding of Stroke Severity) study, where individuals with acute ischemic stroke originating from ipsilateral carotid stenosis of ⩾ 50% underwent 18F-sodium fluoride positron emission tomography (NaF-PET) to measure microcalcification. Tracer uptake was quantified using maximum tissue-to-background ratio (TBRmax). Macrocalcification was measured on computed tomography (CT) using Agatston scoring. Patients were followed up for 6 months for recurrent ipsilateral neurovascular events. RESULTS: Five (27.8%) of 18 individuals had a recurrent ischemic stroke or transient ischemic attack. Ipsilateral carotid plaque NaF uptake at baseline was higher in those with recurrent events compared to those without, and this association remained after adjustment for other vascular risk factors (adjusted odds ratio (aOR) = 1.24, 1.03-1.50). Macrocalcification score in the symptomatic artery was also significantly independently associated with ipsilateral recurrence, but the effect size was relatively smaller (aOR = 1.12, 1.06-1.17 for each 100 unit increase). CONCLUSIONS: Our findings indicate that microcalcification in symptomatic carotid plaques is independently associated with ipsilateral ischemic stroke recurrence. Furthermore, differences in the extent of active microcalcification in macrocalcified plaques may help explain variation in the relationship between calcified carotid plaques and stroke recurrence reported in the literature. Our pilot study indicates that evaluation of carotid artery microcalcification using NaF-PET may be a useful method for risk-stratification of carotid atherosclerosis, though our findings require confirmation in larger cohorts.

Using machine learning to predict carotid artery symptoms from CT angiography: A radiomics and deep learning approach.

Purpose: To assess radiomics and deep learning (DL) methods in identifying symptomatic Carotid Artery Disease (CAD) from carotid CT angiography (CTA) images. We further compare the performance of these novel methods to the conventional calcium score. Methods: Carotid CT angiography (CTA) images from symptomatic patients (ischaemic stroke/transient ischaemic attack within the last 3 months) and asymptomatic patients were analysed. Carotid arteries were classified into culprit, non-culprit and asymptomatic. The calcium score was assessed using the Agatston method. 93 radiomic features were extracted from regions-of-interest drawn on 14 consecutive CTA slices. For DL, convolutional neural networks (CNNs) with and without transfer learning were trained directly on CTA slices. Predictive performance was assessed over 5-fold cross validated AUC scores. SHAP and GRAD-CAM algorithms were used for explainability. Results: 132 carotid arteries were analysed (41 culprit, 41 non-culprit, and 50 asymptomatic). For asymptomatic vs symptomatic arteries, radiomics attained a mean AUC of 0.96(± 0.02), followed by DL 0.86(± 0.06) and then calcium 0.79(± 0.08). For culprit vs non-culprit arteries, radiomics achieved a mean AUC of 0.75(± 0.09), followed by DL 0.67(± 0.10) and then calcium 0.60(± 0.02). For multi-class classification, the mean AUCs were 0.95(± 0.07), 0.79(± 0.05), and 0.71(± 0.07) for radiomics, DL and calcium, respectively. Explainability revealed consistent patterns in the most important radiomic features. Conclusions: Our study highlights the potential of novel image analysis techniques in extracting quantitative information beyond calcification in the identification of CAD. Though further work is required, the transition of these novel techniques into clinical practice may eventually facilitate better stroke risk stratification.

(E)-5,5'-di(thiophen-2-yl)-3,3'-bi[thiophen-3(2H)-ylidene]-2,2'-diones--from conspicuous blue impurities to "quasi-metallic" golden-bronze crystals.

(E)-5,5'-Di(thiophen-2-yl)-3,3'-bi[thiophen-3(2H)-ylidene]-2,2'-dione () has caught the eye of several chemists who have encountered it as a trace by-product in a variety of reactions. We report here the first deliberate synthesis of this intense blue dye (λ(max) 635 nm; ε(max) 32,400 L cm(-1) mol(-1)). We prove on the basis of predictions made with TDDFT that 1a has previously been misassigned as a structural isomer and we correct the visible absorption data that was reported. Derivatives of 1a equipped with pentyl (1b) and butylsulfanyl (1c) groups are readily prepared with our divergent synthetic route (3-7% yield over five steps). Crystals of 1b and 1c exhibit an attractive "quasi-metallic" golden-bronze lustre. This effect is rare in molecular crystals and is observed only with the most intense dyes.

Imaging Carotid Plaque Inflammation Using Positron Emission Tomography: Emerging Role in Clinical Stroke Care, Research Applications, and Future Directions.

Atherosclerosis is a chronic systemic inflammatory condition of the vasculature and a leading cause of stroke. Luminal stenosis severity is an important factor in determining vascular risk. Conventional imaging modalities, such as angiography or duplex ultrasonography, are used to quantify stenosis severity and inform clinical care but provide limited information on plaque biology. Inflammatory processes are central to atherosclerotic plaque progression and destabilization. 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is a validated technique for quantifying plaque inflammation. In this review, we discuss the evolution of FDG-PET as an imaging modality to quantify plaque vulnerability, challenges in standardization of image acquisition and analysis, its potential application to routine clinical care after stroke, and the possible role it will play in future drug discovery.

Novel Targets for Molecular Imaging of Inflammatory Processes of Carotid Atherosclerosis: A Systematic Review.

Computed tomography angiography (CTA), magnetic resonance angiography (MRA) and 18F-FDG-PET have proven clinical value when evaluating patients with carotid atherosclerosis. In this systematic review, we will focus on the role of novel molecular imaging tracers in that assessment and their potential strengths to stratify stroke risk. We systematically searched PubMed, Embase, the Web of Science Core Collection, and Cochrane Library for articles reporting on molecular imaging to noninvasively detect or characterize inflammation in carotid atherosclerosis. As our focus was on nonclassical novel targets, we omitted reports solely on 18F-FDG and 18F-NaF. We summarized and mapped the selected studies to provide an overview of the current clinical development in molecular imaging in relation to risk factors, imaging and histological findings, diagnostic and prognostic performance. We identified 20 articles in which the utilized tracers to visualize carotid wall inflammation were somatostatin subtype-2- (SST2-) (n = 5), CXC-motif chemokine receptor 4- (CXCR4-) (n = 3), translocator protein- (TSPO-) (n = 2) and aVß3 integrin-ligands (n = 2) and choline-tracers (n = 2). Tracer uptake correlated with traditional cardiovascular risk factors, that is, age, gender, diabetes, hypercholesterolemia, and hypertension as well as prior cardiovascular disease. We identified discrepancies between tracer uptake and grade of stenosis, plaque calcification, and 18F-FDG uptake, suggesting the importance of alternative characterization of atherosclerosis beyond classical neuroimaging features. Immunohistochemical analysis linked tracer uptake to markers of macrophage infiltration and neovascularization. Symptomatic carotid arteries showed higher uptake compared to asymptomatic (including contralateral, nonculprit) arteries. Some studies demonstrated a potential role of these novel molecular imaging as a specific intermediary (bio)marker for outcome. Several novel tracers show promise for identification of high-risk plaque inflammation. Based on the current evidence we cautiously propose the SST2-ligands and the choline radiotracers as viable candidates for larger prospective longitudinal outcome studies to evaluate their predictive use in clinical practice.

The contribution of competing mechanisms in stroke despite anticoagulation in patients with atrial fibrillation.

BACKGROUND: For reasons poorly understood, strokes frequently occur in patients with atrial fibrillation (AF) despite oral anticoagulation. Better data are needed to inform randomised trials (RCTs) of new strategies to prevent recurrence in these patients. We investigate the relative contribution of competing stroke mechanisms in patients with AF who have stroke despite anticoagulation (OAC+) compared with those who are anticoagulant naïve (OAC-) at the time of their event. PATIENTS AND METHODS: We performed a cross-sectional study leveraging data from a prospective stroke registry (2015-2022). Eligible patients had ischemic stroke and AF. Stroke classification was performed by a single stroke-specialist blinded to OAC status using TOAST criteria. The presence of atherosclerotic plaque was determined using duplex ultrasonography, computerised tomography (CT) or magnetic resonance (MR) angiography. Imaging was reviewed by a single reader. Logistic regression was used to identify independent predictors of stroke despite anticoagulation. RESULTS: Of 596 patients included, 198 (33.2%) were in the OAC+ group. A competing cause for stroke was more frequent in patients with OAC+ versus OAC- (69/198 (34.8%)) versus 77/398 (19.3%), p < 0.001). After adjustment, both small vessel occlusion (odds ratio (OR): 2.46, 95% CI: 1.20-5.06) and arterial atheroma (⩾50% stenosis) (OR: 1.78, 95% CI: 1.07-2.94) were independently associated with stroke despite anticoagulation. DISCUSSION AND CONCLUSION: Patients with AF-associated stroke despite OAC are much more likely than patients who are OAC-naïve to have competing stroke mechanisms. Rigorous investigation for alternative stroke causes in stroke despite OAC has a high diagnostic yield. These data should be used to guide patient selection for future RCTs in this population.

Protocol for the development of a multidisciplinary clinical practice guideline for the care of patients with chronic subdural haematoma.

Introduction: A common neurosurgical condition, chronic subdural haematoma (cSDH) typically affects older people with other underlying health conditions. The care of this potentially vulnerable cohort is often, however, fragmented and suboptimal. In other complex conditions, multidisciplinary guidelines have transformed patient experience and outcomes, but no such framework exists for cSDH. This paper outlines a protocol to develop the first comprehensive multidisciplinary guideline from diagnosis to long-term recovery with cSDH. Methods: The project will be guided by a steering group of key stakeholders and professional organisations and will feature patient and public involvement. Multidisciplinary thematic working groups will examine key aspects of care to formulate appropriate, patient-centered research questions, targeted with evidence review using the GRADE framework. The working groups will then formulate draft clinical recommendations to be used in a modified Delphi process to build consensus on guideline contents. Conclusions: We present a protocol for the development of a multidisciplinary guideline to inform the care of patients with a cSDH, developed by cross-disciplinary working groups and arrived at through a consensus-building process, including a modified online Delphi.