Circulating c-Met-Expressing Memory T Cells Define Cardiac Autoimmunity.

BACKGROUND: Autoimmunity is increasingly recognized as a key contributing factor in heart muscle diseases. The functional features of cardiac autoimmunity in humans remain undefined because of the challenge of studying immune responses in situ. We previously described a subset of c-mesenchymal epithelial transition factor (c-Met)-expressing (c-Met+) memory T lymphocytes that preferentially migrate to cardiac tissue in mice and humans. METHODS: In-depth phenotyping of peripheral blood T cells, including c-Met+ T cells, was undertaken in groups of patients with inflammatory and noninflammatory cardiomyopathies, patients with noncardiac autoimmunity, and healthy controls. Validation studies were carried out using human cardiac tissue and in an experimental model of cardiac inflammation. RESULTS: We show that c-Met+ T cells are selectively increased in the circulation and in the myocardium of patients with inflammatory cardiomyopathies. The phenotype and function of c-Met+ T cells are distinct from those of c-Met-negative (c-Met-) T cells, including preferential proliferation to cardiac myosin and coproduction of multiple cytokines (interleukin-4, interleukin-17, and interleukin-22). Furthermore, circulating c-Met+ T cell subpopulations in different heart muscle diseases identify distinct and overlapping mechanisms of heart inflammation. In experimental autoimmune myocarditis, elevations in autoantigen-specific c-Met+ T cells in peripheral blood mark the loss of immune tolerance to the heart. Disease development can be halted by pharmacologic c-Met inhibition, indicating a causative role for c-Met+ T cells. CONCLUSIONS: Our study demonstrates that the detection of circulating c-Met+ T cells may have use in the diagnosis and monitoring of adaptive cardiac inflammation and definition of new targets for therapeutic intervention when cardiac autoimmunity causes or contributes to progressive cardiac injury.

Dilated cardiomyopathy and chronic cardiac inflammation: Pathogenesis, diagnosis and therapy.

Dilated cardiomyopathy (DCM) is typically defined by left ventricular dilation and systolic dysfunction in the absence of a clear precipitant. Idiopathic disease is common; up to 50% of patients with DCM have no cause found despite imaging, genetic and biopsy assessments. Treatment remains focused on managing symptoms, reducing the risk of sudden cardiac death and ameliorating the structural and electrical complications of disease progression. In the absence of aetiology-specific treatments, the condition remains associated with a poor prognosis; mortality is approximately 40% at 10 years. The role of immune-mediated inflammatory injury in the development and progression of DCM was first proposed over 30 years ago. Despite the subsequent failures of three large clinical trials of immunosuppressive treatment (ATTACH, RENEWAL and the Myocarditis Treatment Trial), evidence for an abnormal adaptive immune response in DCM remains significant. In this review, we summarise and discuss available evidence supporting immune dysfunction in DCM, with a specific focus on cellular immunity. We also highlight current clinical and experimental treatments. We propose that the success of future immunosuppressive treatment trials in DCM will be dependent on the deep immunophenotyping of patients, to identify those with active inflammation and/or an abnormal immune response who are most likely to respond to therapy.

Refining the risk of HTLV-1-associated myelopathy in people living with HTLV-1: identification of a HAM-like phenotype in a proportion of asymptomatic carriers.

Up to 3.8% of human T-lymphotropic virus type-1 (HTLV-1)-infected asymptomatic carriers (AC) eventually develop HTLV-1-associated myelopathy (HAM). HAM occurs in patients with high (> 1%) HTLV proviral load (PVL). However, this cut-off includes more than 50% of ACs and therefore the risk needs to be refined. As HAM is additionally characterised by an inflammatory response to HTLV-1, markers of T cell activation (TCA), ß2-microglobulin (ß2M) and neuronal damage were accessed for the identification of ACs at high risk of HAM. Retrospective analysis of cross-sectional and longitudinal routine clinical data examining differences in TCA (CD4/CD25, CD4/HLA-DR, CD8/CD25 & CD8/HLA-DR), ß2M and neurofilament light (NfL) in plasma in ACs with high or low PVL and patients with HAM. Comparison between 74 low PVL ACs, 84 high PVL ACs and 58 patients with HAM revealed a significant, stepwise, increase in TCA and ß2M. Construction of receiver operating characteristic (ROC) curves for each of these blood tests generated a profile that correctly identifies 88% of patients with HAM along with 6% of ACs. The 10 ACs with this 'HAM-like' profile had increased levels of NfL in plasma and two developed myelopathy during follow-up, compared to none of the 148 without this viral-immune-phenotype. A viral-immuno-phenotype resembling that seen in patients with HAM identifies asymptomatic carriers who are at increased risk of developing HAM and have markers of subclinical neuronal damage.

A Randomised Controlled Trial Comparing Three Different Radiofrequency Technologies: Short-Term Results of the 3-RF Trial.

OBJECTIVE: To date there has been no comparison of outcomes of endovenous radiofrequency (RF) devices. The 3-RF trial is the first randomised controlled trial of three commercially available RF ablation technologies. METHODS: Patients were recruited [182/302 patients with great saphenous vein (GSV) incompetence] into a prospective double blind randomised trial of Venefit, radiofrequency induced thermal therapy (RFITT), and endovenous radiofrequency (EVRF). The primary outcome measure was GSV closure (total/partial/failed) at six months. Secondary outcome measures included ablation times, complications, pain scores, analgesia requirements, and quality of life (QoL) scores to 12 months. RESULTS: Patients treated [180: Venefit (57), RFITT (64), EVRF (59)] were matched for age, sex, and vein characteristics. At six months, complete GSV closure was significantly better after Venefit and RFITT treatment (100% and 98%, respectively) compared with EVRF treatment (79%, p < .001). Mean treatment time was significantly faster for RFITT than for Venefit and EVRF (p < .0001). Euroqol 5D (EQ5D) visual analogue score (VAS) did not differ between groups at any time point. The only difference between groups in EQ5D domain scores was for the pain/discomfort domain at two weeks when significantly fewer EVRF patients reported no problems compared with Venefit and RFITT. This difference had disappeared at six and 12 months. The Aberdeen Varicose Vein Questionnaire (AVVQ) improved for all groups at six and 12 months compared with pre-treatment levels; however, there was no significant difference between groups. CONCLUSION: Compared with Venefit and RFITT, EVRF was associated with significant failure of truncal ablation at six months; however, clinical outcomes did not differ significantly at 12 months. clinicaltrials.gov identifier: NCT02441881, NHS Health Research Authority (Hampstead Research Ethics Committee) number: 14/LO/1232.

Prediction of atrial fibrillation and stroke using machine learning models in UK Biobank.

Objective: Atrial fibrillation (AF) is the most common cardiac arrythmia, and it is associated with increased risk for ischemic stroke, which is underestimated, as AF can be asymptomatic. The aim of this study was to develop optimal ML models for prediction of AF in the population, and secondly for ischemic stroke in AF patients. Methods: To develop ML models for prediction of 1) AF in the general population and 2) ischemic stroke in patients with AF we constructed XGBoost, LightGBM, Random Forest, Deep Neural Network, Support Vector Machine and Lasso penalised logistic regression models using UK-Biobank's extensive real-world clinical data, questionnaires, as well as biochemical and genetic data, and their predictive performances were compared. Ranking and contribution of the different features was assessed by SHapley Additive exPlanations (SHAP) analysis. The clinical tool CHA2DS2-VASc for prediction of ischemic stroke among AF patients, was used for comparison to the best performing ML model. Findings: The best performing model for AF prediction was LightGBM, with an area-under-the-roc-curve (AUROC) of 0.729 (95% confidence intervals (CI): 0.719, 0.738). The best performing model for ischemic stroke prediction in AF patients was XGBoost with AUROC of 0.631 (95% CI: 0.604, 0.657). The improved AUROC in the XGBoost model compared to CHA2DS2-VASc was statistically significant based on DeLong's test (p-value = 2.20E-06). In addition, the SHAP analysis showed that several peripheral blood biomarkers (e.g. creatinine, glycated haemoglobin, monocytes) were associated with ischemic stroke, which are not considered by CHA2DS2-VASc. Implications: The best performing ML models presented have the potential for clinical use, but further validation in independent studies is required. Our results endorse the incorporation of some routinely measured blood biomarkers for ischemic stroke prediction in AF patients.

Innate and adaptive immunity in acute myocarditis.

Acute myocarditis is an acute inflammatory cardiomyopathy associated with cardiac damage triggered by a virus or a pathological immune activation. It may present with a wide range of clinical presentations, ranging from mild symptoms to severe forms like fulminant myocarditis, characterized by hemodynamic compromise and cardiogenic shock. The immune system plays a central role in the pathogenesis of myocarditis. In fact, while its function is primarily protective, aberrant responses can be detrimental. In this context, both innate and adaptive immunity play pivotal roles; notably, the innate system offers a non-specific and immediate defense, while the adaptive provides specialized protection with immunological memory. However, dysregulation in these systems can misidentify cardiac tissue, triggering autoimmune reactions and possibly leading to significant cardiac tissue damage. This review highlights the importance of innate and adaptive immune responses in the progression and treatment of acute myocarditis.

Community-engaged primary care medical education.

BACKGROUND: Community-engaged medical education (CEME) requires medical schools to partner with local communities to help address community priorities, whilst enhancing the learning experiences of students. Current literature on CEME has focused on evaluating its effects on students; however, there remains a gap in exploring whether CEME initiatives can have a sustainable impact for communities. APPROACH: The Community Action Project (CAP) at Imperial College London, is an eight-week, community-engaged, quality improvement project for Year 3 medical students. Students initially consult with clinicians, patients and wider community stakeholders to understand local needs and assets, and identify a health priority to address. They then work with relevant stakeholders to design, implement and evaluate a project to help address their identified priority. EVALUATION: All CAPs (n = 264) completed in the 2019-2021 academic years were evaluated for evidence of several key areas, including community engagement and sustainability. 91% of projects evidenced a needs analysis, 71% demonstrated patient involvement in their development, and 64% demonstrated sustainable impacts from their projects. Analysis revealed the topics frequently addressed, and the formats used by students. Two CAPs are described in more detail to demonstrate their community impact. IMPLICATIONS: The CAP demonstrates how the principles of CEME (meaningful community engagement and social accountability) can lead to sustainable benefits for local communities through purposeful collaboration with patients and local communities. Strengths, limitations and future directions are highlighted.

Interpersonal violence and depression in Brazil: A cross-sectional analysis of the 2019 National Health Survey.

Depression and interpersonal violence are issues of increasing public health concern globally, especially in low-and-middle income countries. Despite the known relationship between interpersonal violence and an increased risk of depression, there is a need to further characterise the experience of depression in those who have experienced violence, to better develop screening and treatment interventions. A cross-sectional analysis was conducted on responses from the 2019 Brazilian National Health Survey. The prevalence of depression (both clinician-diagnosed, and Patient Health Questionnaire (PHQ-9) screened) were estimated by type of violence experienced in the preceding 12 months (none, physical violence, sexual violence, physical and sexual violence, or threat of violence). Logistic regression models assessed the associations between violence and depression after adjusting for socioeconomic and demographic factors. Of 88,531 respondents, 8.1% experienced any type of violence. Compared to those not experiencing violence, those who experienced any type of violence had a higher prevalence of clinician-diagnosed or PHQ-9-screened depression (e.g. the prevalence of clinician-diagnosed depression was 18.8% for those experiencing sexual violence compared to 9.5% for those not experiencing violence). Both undiagnosed and untreated depression were also more prevalent in those experiencing any type of violence. In logistic regression models, any experience of violence was associated with a higher odds of depression (e.g. aOR = 3.75 (95% CI: 3.06-4.59) for PHQ-9-detected depression). Experiencing violence was also associated with a higher likelihood of having depression which was undiagnosed (e.g. in those who experienced sexual violence: aOR of 3.20, 95% CI 1.81-5.67) or untreated (e.g. in those who experienced physical and sexual violence: aOR = 8.06, 95% CI 3.44-18.9). These findings highlight the need to consider screening for depression in those affected by violence, and to prioritise mental healthcare in communities affected by violence.

Infective endocarditis complicating transcatheter aortic valve implantation.

Infective endocarditis complicating transcatheter aortic valve implantation (TAVI-IE) is a relatively rare condition with an incidence of 0.2%-3.1% at 1 year post implant. It is frequently caused by Enterococci, Staphylococcus aureus and coagulase negative staphylococci While the incidence currently appears to be falling, the absolute number of cases is likely to rise substantially as TAVI expands into low risk populations following the publication of the PARTNER 3 and Evolut Low Risk trials. Important risk factors for the development of TAVI-IE include a younger age at implant and significant residual aortic regurgitation. The echocardiographic diagnosis of TAVI-IE can be challenging, and the role of supplementary imaging techniques including multislice computed tomography (MSCT) and positron emission tomography (18FDG PET) is still emerging. Treatment largely parallels that of conventional prosthetic valve endocarditis (PVE), with prolonged intravenous antibiotic therapy and consideration of surgical intervention forming the cornerstones of management. The precise role and timing of cardiac surgery in TAVI-IE is yet to be defined, with a lack of clear evidence to help identify which patients should be offered surgical intervention. Minimising unnecessary healthcare interventions (both during and after TAVI) and utilising appropriate antibiotic prophylaxis may have a role in preventing TAVI-IE, but robust evidence for specific preventative strategies is lacking. Further research is required to better select patients for advanced hybrid imaging, to guide surgical management and to inform prevention in this challenging patient cohort.

Chemistry of (and on) transition metal clusters: a Fourier transform ion cyclotron resonance study of the reaction of niobium cluster cations with nitric oxide.

The reactions of niobium cluster cations, Nb(+)(n) (n = 2-19), with nitric oxide have been investigated using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR). The overall reaction rate constants are found to be in reasonable agreement with collision rates calculated using the surface charge capture model. The dominant reaction for small clusters (n <9) involves reaction-induced fragmentation resulting in the loss of either NbO or NbN. By contrast, the main reaction observed for the larger clusters (n> 11) is sequential NO chemisorption. Clusters n = 9, 10 exhibit both extremes of behaviour and are the only clusters upon which there is evidence of NO decomposition with N(2) loss observed whenever multiple NO molecules are co-adsorbed. The rate constants for each process have been determined as a function of cluster size.

Advanced imaging improves the diagnosis of infective endocarditis.

Infective endocarditis is a heterogeneous condition whose incidence is rising. Despite advances in surgery and diagnostic methods, one-year mortality has not changed and it remains at 30%. Patients with prosthetic valve and intra-cardiac device-related endocarditis are being seen more frequently and this condition is difficult to diagnose with conventional microbiological and imaging techniques. The modified Duke criteria lack sensitivity in this group and should be supplemented with newer imaging techniques, including 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) and single-photon emission computed tomography (SPECT). In this article, we discuss these techniques and their role in the diagnosis of infective endocarditis.

Poor adherence of randomised trials in surgery to CONSORT guidelines for non-pharmacological treatments (NPT): a cross-sectional study.

OBJECTIVE: To systematically assess adherence of randomised trials in surgery to Consolidated Standards of Reporting Trials (CONSORT) guidelines for non-pharmacological treatments (NPT). Surgical trials are considered more difficult to design and execute than pharmacological trials. Furthermore, the original CONSORT statement does not address some aspects that are vital to the transparent reporting of surgical trials. The CONSORT-NPT extension was designed to address these issues but adherence in medical and surgical journals has not been assessed. DESIGN: Cross-sectional study. SAMPLE: We identified eight general medical and eight surgical journals, indexed in PubMed and published in 2011, with the highest impact factors in their respective categories. MAIN OUTCOMES: Adherence to CONSORT statement and CONSORT-NPT extension items. RESULTS: We identified 54 surgical trials (22 published in medical journals and 32 in surgical journals). There were eight items for which there was less than 30% overall compliance (seven were specific to the CONSORT-NPT extension). These seven items are related to: a full description of the care providers, centres and blinding status in the abstract (n=7/54, 13%), eligibility criteria for centres performing the interventions (n=13/54, 24%), how adherence of care providers with the protocol was assessed or enhanced (n=7/54, 13%), how clustering by care providers or centres was addressed as it relates to sample size (n=3/54, 6%), how care providers were allocated to each group (n=9/54, 17%), how clustering by care providers or centres was addressed as it relates to statistical methods (n=2/54, 4%), a description of care providers (case volume, qualification, expertise, etc) and centres (volume) in each group (n=0/54, 0%). CONCLUSIONS: Adherence of surgical trials to CONSORT-NPT extension items is much poorer than to the standard CONSORT statement. Adherence also appears to be superior in general medical journals compared with surgical journals. Raising awareness and conducting qualitative research to identify areas for specific intervention will be important going forward.

Stereoselective C-C bond formation catalysed by engineered carboxymethylproline synthases.

The reaction of enol(ate)s with electrophiles is used extensively in organic synthesis for stereoselective C-C bond formation. Protein-based catalysts have had comparatively limited application for the stereoselective formation of C-C bonds of choice via enolate chemistry. We describe protein engineering studies on 5-carboxymethylproline synthases, members of the crotonase superfamily, aimed at enabling stereoselective C-C bond formation leading to N-heterocycles via control of trisubstituted enolate intermediates. Active site substitutions, including at the oxyanion binding site, enable the production of substituted N-heterocycles in high diastereomeric excesses via stereocontrolled enolate formation and reaction. The results reveal the potential of the ubiquitous crotonase superfamily as adaptable catalysts for the control of enolate chemistry.

Dramatic size effects and evidence of structural isomers in the reactions of rhodium clusters, Rhn+/-, with nitrous oxide.

The reactions of gas phase rhodium clusters, Rhn+/- (n<30), with nitrous oxide, N2O, have been investigated under single collision conditions by Fourier transform ion cyclotron resonance mass spectrometry. The only significant reaction observed is the sequential generation of oxides. Absolute rate constants for the reactions of all clusters have been determined and, in the case of the cationic clusters especially, they exhibit large fluctuations as a function of cluster size with local minima observed for n=5, 19, 28. Striking similarities are observed with the variation in rate constants for these clusters in reactions with small hydrocarbons (C. Adlhart and E. Uggerud, J. Chem. Phys., 2005, 123, 214709). Corresponding size effects are also observed but are less marked in the reactions of the anionic clusters. The reactions of several clusters exhibit marked deviations from simple pseudo-first-order kinetics suggesting the presence of multiple isomeric forms: Rh11+, Rh12+ and Rh8- exhibit characteristic biexponential decays which are interpreted in terms of the existence of different structural forms of the cluster which have markedly different reactivity. By contrast, Rh6+, Rh7+ and Rh8+ show rates which apparently increase with time, probably due to collisional activation. Thermalisation of the clusters prior to reaction by exposure to pulses of argon results in changes to the kinetics of these anomalous systems which can be explained in terms of collision induced isomerisation.