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A research consortium in which Professor Anna Gloyn is a member has been awarded EU funding of €5.99 million as part of the Horizon 2020 Research and Innovation Framework Progamme.
Automated Coronary Vessels Segmentation in X-ray Angiography Using Graph Attention Network
Accurate coronary vessels segmentation from invasive coronary angiography (ICA) is essential for diagnosis and treatment planning for patients with coronary stenosis. Current machine learning-based approaches primarily utilise convolutional neural networks (CNNs), which heavily focus on the local vessels features and ignore the geometric structures such as the shapes and directions of vessels. This limits the machine understandability of ICA images and creates a bottleneck for improvements of computer-generated segmentation quality, including unstable generalisation ability in low contrast areas and disconnection in vascular structures. To address these issues, we propose a fusion of Graph Attention Network (GAT) and CNN to assist in the learning of global geometric information during coronary vessels segmentation. We train and evaluate the proposed method on a large-scale ICA dataset and demonstrate that combining GAT into a unified network yields improved segmentation performance. Additionally, we utilise specific metrics to demonstrate the achieved improvements, as they offer greater potential for future research and exploration.
Accounting for intensity variation in image analysis of large-scale multiplexed clinical trial datasets.
Multiplex immunofluorescence (mIF) imaging can provide comprehensive quantitative and spatial information for multiple immune markers for tumour immunoprofiling. However, application at scale to clinical trial samples sourced from multiple institutions is challenging due to pre-analytical heterogeneity. This study reports an analytical approach to the largest multi-parameter immunoprofiling study of clinical trial samples to date. We analysed 12,592 tissue microarray (TMA) spots from 3,545 colorectal cancers sourced from more than 240 institutions in two clinical trials (QUASAR 2 and SCOT) stained for CD4, CD8, CD20, CD68, FoxP3, pan-cytokeratin, and DAPI by mIF. TMA slides were multi-spectrally imaged and analysed by cell-based and pixel-based marker analysis. We developed an adaptive thresholding method to account for inter- and intra-slide intensity variation in TMA analysis. Applying this method effectively ameliorated inter- and intra-slide intensity variation improving the image analysis results compared with methods using a single global threshold. Correlation of CD8 data derived by our mIF analysis approach with single-plex chromogenic immunohistochemistry CD8 data derived from subsequent sections indicates the validity of our method (Spearman's rank correlation coefficients ρ between 0.63 and 0.66, p ≪ 0.01) as compared with the current gold standard analysis approach. Evaluation of correlation between cell-based and pixel-based analysis results confirms equivalency (ρ > 0.8, p ≪ 0.01, except for CD20 in the epithelial region) of both analytical approaches. These data suggest that our adaptive thresholding approach can enable analysis of mIF-stained clinical trial TMA datasets by digital pathology at scale for precision immunoprofiling.
Data integration in eHealth: a domain/disease specific roadmap.
The paper documents a series of data integration workshops held in 2006 at the UK National e-Science Centre, summarizing a range of the problem/solution scenarios in multi-site and multi-scale data integration with six HealthGrid projects using schizophrenia as a domain-specific test case. It outlines emerging strategies, recommendations and objectives for collaboration on shared ontology-building and harmonization of data for multi-site trials in this domain.
Tricuspid valve flow measurement using a deep learning framework for automated valve‐tracking 2D phase contrast
AbstractPurposeTricuspid valve flow velocities are challenging to measure with cardiovascular MR, as the rapidly moving valvular plane prohibits direct flow evaluation, but they are vitally important to diastolic function evaluation. We developed an automated valve‐tracking 2D method for measuring flow through the dynamic tricuspid valve.MethodsNine healthy subjects and 2 patients were imaged. The approach uses a previously trained deep learning network, TVnet, to automatically track the tricuspid valve plane from long‐axis cine images. Subsequently, the tracking information is used to acquire 2D phase contrast (PC) with a dynamic (moving) acquisition plane that tracks the valve. Direct diastolic net flows evaluated from the dynamic PC sequence were compared with flows from 2D‐PC scans acquired in a static slice localized at the end‐systolic valve position, and also ventricular stroke volumes (SVs) using both planimetry and 2D PC of the great vessels.ResultsThe mean tricuspid valve systolic excursion was 17.8 ± 2.5 mm. The 2D valve‐tracking PC net diastolic flow showed excellent correlation with SV by right‐ventricle planimetry (bias ± 1.96 SD = −0.2 ± 10.4 mL, intraclass correlation coefficient [ICC] = 0.92) and aortic PC (−1.0 ± 13.8 mL, ICC = 0.87). In comparison, static tricuspid valve 2D PC also showed a strong correlation but had greater bias (p = 0.01) versus the right‐ventricle SV (10.6 ± 16.1 mL, ICC = 0.61). In most (8 of 9) healthy subjects, trace regurgitation was measured at begin‐systole. In one patient, valve‐tracking PC displayed a high‐velocity jet (380 cm/s) with maximal velocity agreeing with echocardiography.ConclusionAutomated valve‐tracking 2D PC is a feasible route toward evaluation of tricuspid regurgitant velocities, potentially solving a major clinical challenge.
Multi-organ abnormalities assessed by a single MRI scan in individuals with blood cancer.
BACKGROUND: During the COVID-19 pandemic individuals with all blood cancers were classified as clinically vulnerable and at high risk of complications and death. Our study sought to determine if individuals with specific blood cancers were at a heightened risk of longer term organ impairment, secondary to SARS-CoV-2 infection. METHODS: We set up a prospective observational study, utilising quantitative multi-parametric MRI to determine organ health over time in patients with specific blood cancers who had recovered from COVID-19. RESULTS: Multi-organ abnormality was more prevalent in blood cancer patients than in healthy controls (42 % vs 6 % p < 0.001) but comparable to the long COVID controls (42 % vs 33 %, p > 0.05). At 6 month follow up scans, organ abnormalities persisted in most individuals with blood cancer (71 % ≥1 organ and 52 % multi-organ). CONCLUSION: A multi-organ MRI platform offers the capacity to accurately evaluate organ health dynamically in blood cancers and detect asymptomatic organ impairment. The application of multi-organ MRI could aid early detection and longitudinal monitoring of organ impairment, potentially guiding more personalised treatment strategies and improving clinical outcomes in many rare diseases.
Cardiac magnetic resonance reveals biventricular impairment in Cushing's syndrome: a multicentre case-control study.
PURPOSE: Cushing's syndrome (CS) is associated with severe cardiovascular (CV) morbidity and mortality. Cardiac magnetic resonance (CMR) is the non-invasive gold standard for assessing cardiac structure and function; however, few CMR studies explore cardiac remodeling in patients exposed to chronic glucocorticoid (GC) excess. We aimed to describe the CMR features directly attributable to previous GC exposure in patients with cured or treated endogenous CS. METHODS: This was a prospective, multicentre, case-control study enrolling consecutive patients with cured or treated CS and patients harboring non-functioning adrenal incidentalomas (NFAI), comparable in terms of sex, age, CV risk factors, and BMI. All patients were in stable condition and had a minimum 24-month follow-up. RESULTS: Sixteen patients with CS and 15 NFAI were enrolled. Indexed left ventricle (LV) end-systolic volume and LV mass were higher in patients with CS (p = 0.027; p = 0.013); similarly, indexed right ventricle (RV) end-diastolic and end-systolic volumes were higher in patients with CS compared to NFAI (p = 0.035; p = 0.006). Morphological alterations also affected cardiac function, as LV and RV ejection fractions decreased in patients with CS (p = 0.056; p = 0.044). CMR features were independent of metabolic status or other CV risk factors, with fasting glucose significantly lower in CS remission than NFAI (p
Sex-Based Outcomes of Dual-Antiplatelet Therapy After Percutaneous Coronary Intervention: A Pairwise and Network Meta-Analysis.
BACKGROUND: Although dual antiplatelet therapy (DAPT) improves the outcomes of patients undergoing percutaneous coronary intervention (PCI), sex-specific differences in efficacy and safety of DAPT remain unresolved. We compared sex differences for DAPT outcomes and DAPT durations (1-3 months [short-term], 6 months [mid-term], and >12 months [extended] vs. 12 months). METHODS: We searched databases through 31 December 2023 for trials reporting DAPT after PCI. The endpoints were major adverse cardiovascular and cerebrovascular events (MACCE), net adverse clinical and cerebrovascular events (NACCE), and any bleeding. Extracted data were pooled in a frequentist network and pairwise, random-effects meta-analysis. RESULTS: Twenty-two trials (99,591 participants, 25.2% female) were included. Female sex was significantly associated with a higher 1-year MACCE risk (hazard ratio 1.14 [95% confidence interval 1.02-1.28]) and bleeding (1.13 [1.00-1.28]), but not NACCE (1.12 [0.96-1.31]). In sub-analyses, the association between female sex and MACCE was related to use of clopidogrel as the second antiplatelet agent (1.11 [1.03-1.20]), whereas higher bleeding events were related to newer P2Y12 inhibitors (P2Y12i) (1.58 [1.01-2.46]). For DAPT duration, short-term DAPT followed by P2Y12i monotherapy was non-inferior for MACCE in females and males (0.95 [95% CI 0.83-1.10; and 0.96 [0.80-1.16]) but tended to be superior in males for NACCE versus 12-month DAPT (0.96 [0.91-1.01]); mid-term DAPT tended to be associated with a lower bleeding risk in males (0.43 [0.17-1.09]). CONCLUSIONS: Female sex is associated with higher MACCE and bleeding when newer P2Y12i agents are used. Short-term DAPT followed by P2Y12i monotherapy is safe and effective in both sexes undergoing PCI. CLINICAL TRIALS REGISTRATION: PROSPERO ID: CRD42021278663.
Illustrated State-of-the-Art Capsules of the ISTH 2024 Congress
Here, we present a series of illustrated capsules from the State of the Art (SOA) speakers at the 2024 International Society on Thrombosis and Haemostasis Congress in Bangkok, Thailand. This year's Congress marks the first time that the International Society on Thrombosis and Haemostasis has held its flagship scientific meeting in Southeast Asia and is the first to be organized by an international Planning Committee. The Bangkok program will feature innovative science and clinical updates from around the world, reflecting the diversity and multidisciplinary growth of our field. In these illustrated SOA capsules, you will find an exploration of novel models of thrombosis and bleeding and biomaterial discoveries that can trigger or block coagulation. Thromboinflammation is now understood to drive many disease states, and the SOA speakers cover cellular and coagulation responses to COVID-19 and other infections. The theme of crosstalk between coagulation and inflammation expands with capsules on protein S signaling, complement, and fibrinolytic inhibitors. Novel agents for hemophilia and thrombosis prevention are introduced. Challenging clinical conditions are also covered, such as inherited platelet disorders and antiphospholipid antibody syndrome. The scientific program in Bangkok will also showcase the work of clinicians and scientists from all parts of the world and chronicle real-world challenges. For example, 2 SOA capsules address the diagnosis and management of von Willebrand disease in low-income settings. Take some time to browse through these short illustrated reviews; we're sure that you'll be entertained, educated, and inspired to further explore the world of thrombosis and hemostasis.
Treatment and Care of Patients with ST-Segment Elevation Myocardial Infarction. What Challenges Remain after Three Decades of Primary Percutaneous Coronary Intervention?
Primary percutaneous coronary intervention (pPCI) has revolutionized the prognosis of ST-segment ele-vation myocardial infarction (STEMI) and is the gold standard treatment. As a result of its success, the number of pPCI centres has expanded worldwide. Despite decades of advancements, clinical outcomes in STEMI patients have plateaued. Out-of-hospital car-diac arrest and cardiogenic shock remain a major cause of high in-hospital mortality, whilst the growing burden of heart failure in long-term STEMI survivors presents a growing problem. Many elements aiming to optimize STEMI treatment are still subject to debate or lack sufficient evidence. This review provides an overview of the most contentious current issues in pPCI in STEMI patients, with an emphasis on unresolved questions and persistent challenges.
Aldehyde-mediated inhibition of asparagine biosynthesis has implications for diabetes and alcoholism.
Patients with alcoholism and type 2 diabetes manifest altered metabolism, including elevated aldehyde levels and unusually low asparagine levels. We show that asparagine synthetase B (ASNS), the only human asparagine-forming enzyme, is inhibited by disease-relevant reactive aldehydes, including formaldehyde and acetaldehyde. Cellular studies show non-cytotoxic amounts of reactive aldehydes induce a decrease in asparagine levels. Biochemical analyses reveal inhibition results from reaction of the aldehydes with the catalytically important N-terminal cysteine of ASNS. The combined cellular and biochemical results suggest a possible mechanism underlying the low asparagine levels in alcoholism and diabetes. The results will stimulate research on the biological consequences of the reactions of aldehydes with nucleophilic residues.
New characterization and safety evaluation of human limbal stem cells used in clinical application: fidelity of mitotic process and mitotic spindle morphologies
Abstract Background Limbal stem cells (LSCs) are crucial for the regeneration of the corneal epithelium in patients with limbal stem cell deficiency (LSCD). Thus, LSCs during cultivation in vitro should be in highly homogeneous amounts, while potency and expression of stemness without tumorigenesis would be desirable. Therefore, further characterization and safety evaluation of engineered limbal grafts is required to provide safe and high-quality therapeutic applications. Methods After in vitro expansion, LSCs undergo laboratory characterization in a single-cell suspension, cell culture, and in limbal grafts before transplantation. Using a clinically applicable protocol, the data collected on LSCs at passage 1 were summarized, including: identity (cell size, morphology); potency (yield, viability, population doubling time, colony-forming efficiency); expression of putative stem cell markers through flow cytometry, immunofluorescence, and immunohistochemistry. Then, mitotic chromosome stability and normal mitotic outcomes were explored by using live-cell imaging. Finally, impurities, bacterial endotoxins and sterility were determined. Results Expression of the stemness marker p63 in single-cell suspension and in cell culture showed high values by different methods. Limbal grafts showed p63-positive cells (78.7 ± 9.4%), Ki67 proliferation (41.7 ± 15.9%), while CK3 was negative. Impurity with 3T3 feeder cells and endotoxins was minimized. We presented mitotic spindles with a length of 11.40 ± 0.54 m and a spindle width of 8.05 ± 0.55 m as new characterization in LSC culture. Additionally, live-cell imaging of LSCs (n = 873) was performed, and only a small fraction < 2.5% of aberrant interphase cells was observed; 2.12 ± 2.10% of mitotic spindles exhibited a multipolar phenotype during metaphase, and 3.84 ± 3.77% of anaphase cells had a DNA signal present within the spindle midzone, indicating a chromosome bridge or lagging chromosome phenotype. Conclusion This manuscript provides, for the first time, detailed characterization of the parameters of fidelity of the mitotic process and mitotic spindle morphologies of LSCs used in a direct clinical application. Our data show that p63-positive CK3-negative LSCs grown in vitro for clinical purposes undergo mitotic processes with extremely high fidelity, suggesting high karyotype stability. This finding confirms LSCs as a high-quality and safe therapy for eye regeneration in humans.
Stratification of acute myocardial and endothelial cell injury, salvage index and final infarct size by systematic microRNA profiling in acute ST-elevation myocardial infarction.
AIM: Acute injury and subsequent remodelling responses to ST-segment elevation myocardial infarction (STEMI) are major determinants of clinical outcome. Current imaging and plasma biomarkers provide delayed readouts of myocardial injury and recovery. Here, we sought to systematically characterize all microRNAs (miRs) released during the acute phase of STEMI and relate miR release to magnetic resonance imaging (MRI) findings to predict acute and late responses to STEMI, from a single early blood sample. METHODS AND RESULTS: miRs were quantified in blood samples obtained from patients after primary PCI (PPCI) for STEMI. Cardiac MRI (cMRI) was performed to quantify myocardial edema, infarct size and salvage index. Regression models were constructed to predict these outcomes measures, which were then tested with a validation cohort. Transcoronary miR release was quantified from paired measurements of coronary artery and coronary sinus samples. A cell culture model was used to identify endothelial cell-derived miRs.A total of 72 patients undergoing PPCI for acute STEMI underwent miR analysis and cMRI. About >200 miRs were detectable in plasma after STEMI, from which 128 miRs were selected for quantification in all patients. Known myocardial miRs demonstrated a linear correlation with troponin release, and these increased across the transcoronary gradient. We identified novel miRs associated with microvascular injury and myocardial salvage. Regression models were constructed using a training cohort, then tested in a validation cohort, and predicted myocardial oedema, infarct size and salvage index. CONCLUSION: Analysis of miR release after STEMI identifies biomarkers that predict both acute and late outcomes after STEMI. A novel miR-based biomarker score enables the estimation of area at risk, late infarct size and salvage index from a single blood sample 6 hours after PPCI, providing a simple and rapid alternative to serial cMRI characterization of STEMI outcome.
Ventriculoperitoneal shunt failures at Red Cross War Memorial Children's Hospital.
INTRODUCTION: Ventriculoperitoneal shunt (VP shunt) insertion is one of the mainstays of treatment of hydrocephalus and although very effective, a high rate of shunt failure persists globally. The purpose of the study was to quantify the ventriculoperitoneal shunt failure rate at Red Cross War Memorial Children's Hospital (RCWMCH) and assess potential factors contributing to shunt failures. METHODS: A retrospective review of VP shunts done at RCWMCH between August 2015 through December 2019 was performed. Operative notes, discharge summaries and patient folders were reviewed to collect information about patient age, aetiology of hydrocephalus, index vs revision shunt, shunt system and other noticeable variables. Overall shunt failure was recorded. Univariate and multivariate models were used to determine causal relationship. RESULTS: Four hundred and ninety-four VP shunt operations were performed on 340 patients with 48.8% being index shunts and 51.2% revision shunts. The average patient age was 3.4 months. The total VP shunt failure rate over the study period was 31.2%, with a 7.3% infection rate, 13.6% blockage and 3.6% disconnection rate. The most common aetiologies were post-infectious hydrocephalus 29.4%, myelomeningocele 19.7% and premature intraventricular haemorrhage 14.1%. Orbis-sigma II (OSVII), distal slit valves and antibiotic-impregnated catheters were used most frequently. Failure rates were highest in the revision group, 34.7% compared to 27.3% in index shunts. Sixty-five percent (65%) of the head circumferences measured were above the + 3 Z score (> 90th centile). CONCLUSION: VP shunt failure occurs most commonly in revision surgery, and care should be taken at the index operation to reduce failure risk. Surgeon level, duration of surgery, aetiology of hydrocephalus and shunt system used did not influence overall failure rates. A closer look at larger head circumferences, their effect on shunt systems and the socio-economic factors behind late presentations should be investigated further in the future.
Exercise Capacity in Patients With Obstructive Hypertrophic Cardiomyopathy: SEQUOIA-HCM Baseline Characteristics and Study Design.
Patients with obstructive hypertrophic cardiomyopathy (oHCM) have increased risk of arrhythmia, stroke, heart failure, and sudden death. Contemporary management of oHCM has decreased annual hospitalization and mortality rates, yet patients have worsening health-related quality of life due to impaired exercise capacity and persistent residual symptoms. Here we consider the design of clinical trials evaluating potential oHCM therapies in the context of SEQUOIA-HCM (Safety, Efficacy, and Quantitative Understanding of Obstruction Impact of Aficamten in HCM). This large, phase 3 trial is now fully enrolled (N = 282). Baseline characteristics reflect an ethnically diverse population with characteristics typical of patients encountered clinically with substantial functional and symptom burden. The study will assess the effect of aficamten vs placebo, in addition to standard-of-care medications, on functional capacity and symptoms over 24 weeks. Future clinical trials could model the approach in SEQUOIA-HCM to evaluate the effect of potential therapies on the burden of oHCM. (Safety, Efficacy, and Quantitative Understanding of Obstruction Impact of Aficamten in HCM [SEQUOIA-HCM]; NCT05186818).