18F-FDG PET/CT in left ventricular assist device infections: In-depth characterization and clinical implications

BACKGROUND

Previous retrospective studies suggest a good diagnostic performance of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET)/computed tomography (CT) in left ventricular assist device (LVAD) infections. Our aim was to prospectively evaluate the role of PET/CT in the characterization and impact on clinical management of LVAD infections.

METHODS

A total of 40 patients (aged 58 [53-62] years) with suspected LVAD infection and 5 controls (aged 69 [64-71] years) underwent 18F-FDG-PET/CT. Four LVAD components were evaluated: exit site and subcutaneous driveline (peripheral), pump pocket, and outflow graft. The location with maximal uptake was considered the presumed site of infection. Infection was confirmed by positive culture (exit site or blood) and/or surgical findings.

RESULTS

Visual uptake was present in 40 patients (100%) in the infection group vs 4 (80%) control subjects. For each individual component, the presence of uptake was more frequent in the infection than in the control group. The location of maximal uptake was most frequently the pump pocket (48%) in the infection group and the peripheral components (75%) in the control group. Maximum standard uptake values (SUVmax) were higher in the infection than in the control group: SUVmax (average all components): 6.9 (5.1-8.5) vs 3.8 (3.7-4.3), p = 0.002; SUVmax (location of maximal uptake): 10.6 ± 4.0 vs 5.4 ± 1.9, p = 0.01. Pump pocket infections were more frequent in patients with bacteremia than without bacteremia (79% vs 31%, p = 0.011). Pseudomonas (32%) and methicillin-susceptible Staphylococcus aureus (29%) were the most frequent pathogens and were associated with pump pocket infections, while Staphylococcus epidermis (11%) was associated with peripheral infections. PET/CT affected the clinical management of 83% of patients with infection, resulting in surgical debridement (8%), pump exchange (13%), and upgrade in the transplant listing status (10%), leading to 8% of urgent transplants.

CONCLUSIONS

18F-FDG-PET/CT enables the diagnosis and characterization of the extent of LVAD infections, which can significantly affect the clinical management of these patients.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

A radiologist's guide to median sternotomy

Median sternotomy is widely recognised as the primary incision technique in cardiac surgery. This surgical procedure involves dividing the sternum to gain access to the heart and lungs, making it invaluable in correcting congenital heart defects. Furthermore, it is frequently employed in adult patients, particularly during coronary artery bypass graft (CABG) procedures. In this imaging review, we present a comprehensive overview of the pre-procedural assessment and various post-sternotomy complications encountered within our clinical experience at a tertiary cardiothoracic centre. The focus of this review is to outline the imaging features associated with mediastinal adhesions and establish the minimal safe distance between the sternum and common mediastinal structures when considering re-sternotomy. By providing visual examples, we aim to facilitate a better understanding of these key concepts. Moreover, we delve into a detailed discussion of a spectrum of postoperative complications that may arise following median sternotomy including those related to metalwork (sternal wire fracture), bone (sternal dehiscence, non-union and osteomyelitis), and soft tissue (abscess, haematoma).

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

INTRODUCTION

The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures.

METHODS

In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025.

FINDINGS

Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2-6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5-5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4-10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32-4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23-11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation.

INTERPRETATION

After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Perivascular wall tumour presenting as pastern mass in a Standardbred gelding

A 2-year-old Standardbred gelding was referred for a mass on the palmaromedial right front pastern which was accompanied by progressively worsening lameness. The mass was firm to palpation and covered by normal skin. Ultrasonographically, a smooth encapsulated mass was present, medial to the flexor tendons and palmar to the neurovascular bundle. Because of a poor prognosis for future athletic performance without surgical or chemotherapeutic intervention and economic constraints preventing further diagnostics and treatment, the horse was euthanised. Post-mortem magnetic resonance imaging, histopathology and immunohistochemistry revealed the mass to be a perivascular wall tumour, the first record of such a neoplasia in the horse.

Examining spatial variation for immunisation coverage in pregnant women: A nationwide and geospatial retrospective cohort study in Aotearoa New Zealand

BACKGROUND

Maternal influenza and pertussis immunisation is crucial for protecting mothers during pregnancy and their babies in the first weeks of life against severe disease. We examined geospatial variation in maternal immunisation coverage among pregnant women in Aotearoa New Zealand and its health equity implications.

METHOD

We constructed a retrospective cohort including all pregnant women who delivered between 01 January 2013 and 31 December 2020 using administrative health datasets. Our outcomes were receipt of influenza or pertussis vaccine in any one of three relevant national databases (e.g. National Immunisation Register, Proclaims, or Pharmaceutical collection) during the eligible pregnancy.

RESULTS

Data from our retrospective cohort study show significant regional variation in maternal immunisation coverage for both influenza and pertussis from 2013 to 2020. Maximal coverage was around 50% in the best performing regions, which means that half of the women who were pregnant (183,737 women) were not protected. In addition, we found significant spatio-temporal variation and clustering of immunisation coverage. Our findings are interactively available to explore here: https://geohealthlab.shinyapps.io/hapumama/ CONCLUSION: Our study is one of the first to examine spatial variation in maternal vaccination coverage in pregnant women at a national level over space and time. This provides powerful tools to measure the impact of interventions to improve coverage at national and regional levels, with specific reference to inequities between ethnic groups, likely applicable to similar settings internationally.

Tritium Beta Spectrum Measurement and Neutrino Mass Limit from Cyclotron Radiation Emission Spectroscopy

The absolute scale of the neutrino mass plays a critical role in physics at every scale, from the subatomic to the cosmological. Measurements of the tritium end-point spectrum have provided the most precise direct limit on the neutrino mass scale. In this Letter, we present advances by Project 8 to the cyclotron radiation emission spectroscopy (CRES) technique culminating in the first frequency-based neutrino mass limit. With only a cm^{3}-scale physical detection volume, a limit of m_{β}<155  eV/c^{2} (152  eV/c^{2}) is extracted from the background-free measurement of the continuous tritium beta spectrum in a Bayesian (frequentist) analysis. Using ^{83m}Kr calibration data, a resolution of 1.66±0.19  eV (FWHM) is measured, the detector response model is validated, and the efficiency is characterized over the multi-keV tritium analysis window. These measurements establish the potential of CRES for a high-sensitivity next-generation direct neutrino mass experiment featuring low background and high resolution.

Impact of Voluntary, Community and Social Enterprise (VCSE) Organisations Working with Underserved Communities with Type 2 Diabetes Mellitus in England

The Voluntary, Community and Social Enterprise (VCSE) sector offers services and leadership within the health and care system in England and has a specialist role in working with underserved, deprived communities. This evaluation aims to identify best practices in self-management support for those living with type 2 diabetes mellitus (T2DM) and to develop a theory of change (TofC) through understanding the impact of VCSE organisations on diabetes management. An appreciative inquiry (AI) was carried out and co-delivered using qualitative interviews and an embedded analysis with VCSE partners. A voluntary service coordinated seven VCSE organisations who assisted with recruiting their service users and undertook interviews to identify the impact of existing activities and programmes. People living with T2DM were interviewed about services. Themes were as follows: (a) individual and group activities; (b) trusted services and relationships across the community; (c) long-term engagement; (d) sociocultural context of diet and nutritional choices; (e) experience of adaptation; and (f) culturally appropriate advice and independent VCSE organisations. The structured educational approach (DESMOND) for T2DM was accessed variably, despite these services being recommended by NICE guidelines as a standard intervention. The VCSE offered continuity and culturally appropriate services to more marginalised groups. This evaluation highlights the importance of targeted engagement with underserved communities, particularly where primary care services are more limited. The TofC is a unique insight into the impact of VCSE services, offering bespoke support to manage T2DM, suggesting areas for improvements in capacity and offering the capability to sustain the VCSE sector as an essential element of the T2DM care pathway in England.

New Zealand and Australian MRI technologists' (radiographers) MRI safety knowledge and confidence levels

INTRODUCTION

The MRI technologist (radiographer) is at the frontline of MRI safety decision-making and has the primary responsibility to provide high quality, efficient and safe patient care in the MRI environment. As MRI technology advances and new safety issues emerge, this study aimed to provide a snapshot of the preparedness of MRI technologists in New Zealand (NZ) and Australia to practise confidently and safely.

METHOD

An online questionnaire, administered via Qualtrics and covering a range of MRI safety topics, was distributed in 2018 via the New Zealand MR Users Group, the MRI Australia-NZ Group Facebook, and relevant professional bodies.

RESULTS

A total of 312 MRI technologists attempted the questionnaire, with 246 surveys being fully completed. Of these, 61% (n = 149) were in Australia, 36% (n = 89) in NZ, and 3% (n = 8) from other countries. Findings indicated that current MRI education is preparing MRI technologists in NZ and Australia to practise safely. However, while these technologists are confident in their MRI safety decision-making, accuracy levels within some groups need addressing.

CONCLUSION

To develop a consistent level of safe practice, it is proposed that a minimum level of MRI-specific education is defined and mandated to practise. Continuing professional development focussing on MRI safety must be encouraged and, if audited as part of registration, could also be mandated. Implementation of a supporting regulatory framework similar to NZ is recommended for other countries.

IMPLICATIONS FOR PRACTICE

All MRI technologists are responsible for the safety of their patients and staff. Employers must support and ensure MRI-specific education has been completed. Ongoing engagement in MRI safety events provided by MRI safety experts, professional bodies and/or universities is essential to remain up-to-date.

The association between food desert severity, socioeconomic status, and metabolic state during pregnancy in a prospective longitudinal cohort

Poor metabolic health during pregnancy is associated with health concerns for pregnant individuals and their offspring. Lower socioeconomic status (SES) is one risk factor for poor metabolic health, and may be related to limited access to healthful and affordable foods (e.g., living in a food desert). This study evaluates the respective contributions of SES and food desert severity on metabolic health during pregnancy. The food desert severity of 302 pregnant individuals was determined using the United States Department of Agriculture Food Access Research Atlas. SES was measured using total household income adjusted for household size, years of education, and amount of reserve savings. Information about participants' glucose concentrations one hour following an oral glucose tolerance test during the second trimester was extracted from medical records and percent adiposity during the second trimester was assessed using air displacement plethysmography. Information about participants' nutritional intake during the second trimester was obtained by trained nutritionists via three unannounced 24-h dietary recalls. Structural equation models showed that lower SES predicted higher food desert severity (β = - 0.20, p = 0.008) and higher adiposity (β = - 0.27, p = 0.016) and consumption of a more pro-inflammatory diet (β = - 0.25, p = 0.003) during the second trimester of pregnancy. Higher food desert severity also predicted higher percent adiposity during the second trimester (β = 0.17, p = 0.013). Food desert severity significantly mediated the relationship between lower SES and higher percent adiposity during the second trimester (βindirect = - 0.03, 95% CI [- 0.079, - 0.004]). These findings indicate that access to healthful and affordable foods is a mechanism by which SES contributes to adiposity during pregnancy and may inform interventions intended to improve metabolic health during pregnancy.

The Extra-Islet Pancreas Supports Autoimmunity in Human Type 1 Diabetes

In autoimmune Type 1 diabetes (T1D), immune cells progressively infiltrate and destroy the islets of Langerhans - islands of endocrine tissue dispersed throughout the pancreas. However, it is unclear how this process, called 'insulitis', develops and progresses within this organ. Here, using highly multiplexed CO-Detection by indEXing (CODEX) tissue imaging and cadaveric pancreas samples from pre-T1D, T1D, and non-T1D donors, we examine pseudotemporal-spatial patterns of insulitis and exocrine inflammation within large pancreatic tissue sections. We identify four sub-states of insulitis characterized by CD8 ⁺ T cells at different stages of activation. We further find that exocrine compartments of pancreatic lobules affected by insulitis have distinct cellularity, suggesting that extra-islet factors may make particular lobules permissive to disease. Finally, we identify "staging areas" - immature tertiary lymphoid structures away from islets where CD8 ⁺ T cells appear to assemble before they navigate to islets. Together, these data implicate the extra-islet pancreas in autoimmune insulitis, greatly expanding the boundaries of T1D pathogenesis.

JS07.5.A 18F-fluciclovine PET and multi-parametric MRI to distinguish pseudoprogression from tumor progression in post-treatment glioblastoma

Background

Differentiation of tumor progression (TP) from pseudoprogression (PsP) is a major unmet need in glioblastoma (GBM). 18F-Fluciclovine is a synthetic amino acid PET radiotracer with higher uptake in tumor tissue vs. areas of treatment-related change. We aimed to assess the combined value of 18F-Fluciclovine PET and multi-parametric MRI for differentiating PsP from TP.

Material and Methods

We enrolled 30 patients with GBM with a new or enlarging contrast-enhancing lesion on MRI after chemoradiotherapy who were planned for surgical resection of the lesion. Patients underwent pre-operative 18F-Fluciclovine PET and multi-parametric MRI. Following surgery, the relative percentages of viable tumor and therapy-related changes observed on histopathology were quantified. Patients were categorized as TP if viable tumor represented ≥ 50% of the specimen, mixed TP if &lt; 50% and &gt; 10%, and PsP if ≤ 10%. SUVmax, SUVpeak, and 50% threshold SUVmean were calculated and normalized to contralateral brain, pituitary gland, and superior sagittal sinus (SSS). The least absolute shrinkage and selection operator (LASSO) was used to determine the variables most predictive of tumor percentage. The strength of association between the primary outcome and selected variables was assessed by Pearson’s or Point-biserial correlation.

Results

18 patients with TP, 4 with mixed TP-PsP, and 8 with PsP were included. There was a positive correlation between 50% threshold SUV mean measured from PET images acquired 50-60 minutes post-injection and rCBVmax by MRI and tumor percentage by histology (r= 0.56; p= 0.004 and r=0.50; p=0.012 respectively). 40-50 minutes SUVmax (OR=1.78 rpb=0.51) and rCBVmax (OR=1.64, rpb=0.48) were positively correlated with tumor TP/mixed TP group. Patients who demonstrated TP/mixed TP-PsP had significantly higher 40-50 minutes SUVmax compared to patients with histological PsP (6.71±2.03 vs 3.93±1.63; p=0.012). 40-50 minutes SUVmax cut-off of 4.46 provided 90% sensitivity and 80% specificity for differentiation of TP/mixed TP-PsP from PsP (AUC=0.88). Combining a 40-50 minutes SUVmax cut-off of 4.46 and an rCBVmax cut-off of 3.67 provided 100% sensitivity and 100% specificity for differentiating TP/mixed TP-PsP from PsP (AUC=1). Patients who demonstrated TP had a significantly higher 40-50 minutes SUVmax compared to patients with histological PsP (6.99±2.06 vs 3.93±1.63; p=0.008). A 40-50 minutes SUVmax cut-off of 4.66 provided 94% sensitivity and 80% specificity for differentiation of TP from PsP (AUC=0.89).

Conclusion

18F-Fluciclovine PET uptake is positively correlated with viable tumor quantification on histology and can accurately differentiate PsP from TP in patients with GBM. Further independent studies are required to cross-validate these promising early results.

Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Clinical Feasibility of Speech Phenotyping for Remote Assessment of Neurodegenerative and Psychiatric Disorders (RHAPSODY): a study protocol

Introduction

The diagnosis of neurodegenerative and psychiatric disorders (NPDs) in primary care can suffer from inefficiencies resulting in misdiagnoses and delayed diagnosis, limiting effective treatment options. The development of speech and language-based profiling biomarkers could aid in achieving earlier motor diagnosis for PD for instance, or more accurate diagnosis of clinically similar or late presenting NPDs.

Objectives

RHAPSODY aims to investigate the feasibility of the remote administration of a battery of speech tasks in eliciting continuous narrative speech across a range of NPDs. The project also aims to determine the feasibility of using acoustic and linguistic biomarkers from speech data to support the clinical assessment and disambiguation of common NPDs

Methods

All participants (n=250) will take part in a single virtual telemedicine video conference with a researcher in which they are screened and complete a battery of speech tasks, in addition to cohort-specific screening measures. Over the following month, participants will be asked to complete a series of short, self-administered speech assessments via a smartphone application.

Results

The speech tasks will be audio-recorded and analysed on Novoic’s technology platform. Objectives will be analysed using measures including average length of speech elicitation for speech tasks, intra- and inter-subject variance, differences in linguistic patterns, and response rates to speech assessments.

Conclusions

The analyses could help to identify and validate speech-derived clinical biomarkers to support clinicians in detecting and disambiguating between NPDs with heterogeneous presentations. This should further support earlier intervention, improved treatment options and improved quality of life.

Disclosure

In terms of significant financial interest and relationships, it is emphasised that the private organisation Novoic, who aim to develop speech algorithms for diagnostic use, is the study’s sponsor and employees or former employees of this company comprise

Care pathways for people with major depressive disorder

Introduction

Major depressive disorder (MDD) is a leading cause of disability worldwide, in part due to its high prevalence and high rates of comorbidities, recurrence, chronicity and treatment-resistance. These indicate that MDD is treated suboptimally despite a multitude of effective interventions and well-regarded best-practice treatment guidelines. To improve the management of MDD, the nature and extent of ‘gaps’ in care pathways need to be understood.

Objectives

We aimed to: 1. Identify ‘treatment gaps’ and patient needs along the care pathway, and determine the extent of these gaps (i.e. discrepancy between best- and current-practice). 2. Propose policy recommendation on how minimise treatment gaps for MDD.

Methods

Care pathway analysis: A set of relevant treatment gaps were agreed upon, a priori, based on gold-standard stepped-care guidelines. Data was gathered from a variety of sources in six countries (UK, Sweden, Germany, Italy, Portugal, Hungary). Policy recommendations: To attain expert consensus on proposed recommendations, a modified-Delphi approach was undertaken with a multidisciplinary panel of experts across Europe.

Results

Taken together, data indicated that: ˜50% of episodes are undiagnosed, lifetime delay to treatment averages ˜4 years, ˜25-50% of patients are treated at any one time, ˜30-65% are followed up within 3 months of treatment, ˜5-25% can access psychiatric services. 28 specific recommendations to optimise pathways were made to enhance MDD detection (pathway entry), increase multimodal treatment, facilitate continuity of follow-up after treatment and increase access to specialist care.

Conclusions

There are concerning treatment gaps in depression care across Europe, from the proportion of people not being diagnosed to those stagnating in primary care with impairing, persistent illness.

Disclosure

No significant relationships.

Creating a Digital Psychoeducation Programme for bipolar disorder in the COVID-19 pandemic

Introduction

The Covid-19 pandemic profoundly affected delivery and accessibility of mental health care services at a time when most needed. The OPTIMA Mood Disorder Service, a specialist bipolar disorder service, adapted group psychoeducation programme for delivery on-line.

Objectives

We report the feasibility of creating a digital psychoeducation programme.

Methods

The OPTIMA ten session group psychoeducation programme was converted into a ‘Digital’ intervention using video-conferencing. Sessions offered a range of key topics, derived from the initial Barcelona Group Psychoeducation Programme. At the time of writing, OPTIMA had fully completed two 10 session digital courses.

Results

A total of 12 people (6 in each group) consented to be part of a service evaluation of the digital groups. Just over half of the participants were women (7/12; 58.3%) and one identified as being non-binary (8.3); remaining participants were men. Age of participants ranged from 25 years to 65 years (Mean=42.3; SD=13.1). Data showed a high level of engagement (77%) All participants reported some improvement with a mean Bipolar Self-Efficacy scale (BPSES) post-group score of 105.6 (SD=14.8). At group level, this change was not statistically significant (F (1, 15) = 0.71, p=0.41). At an individual level, two out of five showed a reliable change index >1.96.

Conclusions

Delivering a ‘digital’ group psychoeducation programme was possible due to careful planning and programme development. There was good uptake from service users suggesting it is a feasible approach with preliminary evidence of clinical benefit.

Disclosure

No significant relationships.

Validation of in vivo toenail measurements of manganese and mercury using a portable X-ray fluorescence device

BACKGROUND AND OBJECTIVE

Toenail metal concentrations can be used as an effective biomarker for exposure to environmental toxicants. Typically toenail clippings are measured ex vivo using inductively coupled plasma mass spectrometry (ICP-MS). X-ray fluorescence (XRF) toenail metal measurements done on intact toenails in vivo could be used as an alternative to alleviate some of the disadvantages of ICP-MS. In this study, we assessed the ability to use XRF to measure toenail metal concentrations in real-time without having to clip the toenails (i.e., in vivo) in two occupational settings for exposure assessment of manganese and mercury.

MATERIALS AND METHODS

The portable XRF method used a 3-min in vivo measurement of toenails prior to clipping and was assessed against ICP-MS measurement of toenail clippings taken immediately after the XRF measurement and work history for a group of welders (n = 16) assessed for manganese exposure and nail salon workers (n = 10) assessed for mercury exposure.

RESULTS AND CONCLUSIONS

We identified that in vivo XRF metal measurements were able to discern exposure to manganese in welders and mercury in nail salon workers. We identified significant positive correlations between ICP-MS of clippings and in vivo XRF measures of both toenail manganese (R = 0.59, p = 0.02) and mercury (R = 0.74, p < 0.001), as well as between in vivo XRF toenail manganese and work history among the welders (R = 0.55, p = 0.03). We identified in vivo XRF detection limits to be 0.5 µg/g for mercury and 2.6 µg/g for manganese. Further work should elucidate differences in the timing of exposure using the in vivo XRF method over toenail clippings and modification of measurement time and x-ray setting to further decrease the detection limit. In vivo portable, XRF measurements can be used to effectively measure toenail Mn and Hg in occupational participants in real-time during study visits and at a fraction of the cost.

Immune Response in Heart Transplant Patients Following COVID-19 Vaccination

Purpose

Previous studies have described poor outcomes in heart transplant patients who develop COVID-19 infection. Therefore, we sought to characterize a single center's experience with heart transplant patient outcomes during the COVID-19 pandemic and the recent role of vaccination in mitigating the risk of mortality.

Methods

From a single center, we identified all orthotopic heart transplant patients alive at the beginning of the COVID-19 pandemic in March 2020. All patients were followed from the start of the pandemic until their most recent follow up or death. Baseline comorbidities and immediate outcomes data were obtained from the Society for Thoracic Surgery (STS) Adult Cardiac Surgery Database (ACSD). Multiple logistic regression analyzed the association between vaccination status, baseline covariates, and other standard STS outcome measures. Non-parametric tests were used to compare different subgroups.

Results

We included 153 patients, of which 20.9% developed COVID-19 infection (32/153) with 40.6% (13/32) requiring hospitalization and 15.6% of those patients (5/32) dying as a direct result of COVID-19 pneumonia. Kaplan-Meier survival analysis revealed that unvaccinated patients had a significantly higher rate of all-cause mortality as compared to those patients that were fully vaccinated despite similar baseline characteristics (p < 0.001). Patients with previous COVID-19 infection in addition to vaccination had significantly higher IgG titers as compared to those only vaccinated (6568.50 AU/mL vs. 58.05 AU/mL, p = 0.002).

Conclusion

Immunization against COVID-19 is associated with a significant reduction in the mortality of heart transplant patients. IgG titers were variable among heart transplant patients who received the vaccine with the highest titers seen in those patients with a personal history of COVID-19. The implications of IgG levels are still unknown.

303 Mapping the Landscape of Surgical Registries in the United Kingdom

Introduction

Well-designed surgical registries are essential for high-quality patient-centred evaluation of implantable devices and surgical procedures. The importance of registries was highlighted in the recent Cumberlege report that detailed important innovation failures such as the use of vaginal mesh. Many surgical registries exist, but it is currently unclear how different registries are funded; designed; what data are collected; how databases are hosted and if the data can be linked to other datasets. There is therefore a need to understand the characteristics of and variation in existing surgical registries to make recommendations for how these could be improved. The aim of this work is to identify existing surgical registries in the UK and describe and summarise their key characteristics to inform recommendations for how surgical registries may be improved.

Method

Existing surgical registries will be identified using multiple different sources, including society websites; search engine review; a targeted search of Medline and Embase databases and expert knowledge. Details of each registry will be extracted using a standardised data extraction proforma developed by the study team. Characteristics of identified registries will be summarised into a narrative review.

Results

Identification of registries is ongoing. Preliminary data extraction has highlighted marked heterogeneity in the design, content, and structure of existing surgical registries. Data extraction is ongoing, but results will be available for presentation at the ASIT meeting.

Conclusions

There is considerable heterogeneity in existing surgical registries. Further work is needed to establish the extent of this variation and identify areas that can be improved.

Flow vorticity relationships with right ventricular geometry in adult tetralogy of Fallot

Background

Repaired tetralogy of Fallot adults (rToF) undergo right ventricular (RV) remodeling, in part due to volume overload of residual pulmonary regurgitation volume (PRV). Time-resolved phase-contrast cardiac magnetic resonance imaging (4D Flow MRI) enables the qualitative and quantitative measurement of altered blood flow patterns, including vorticity. Cardiac atlases allow for complex three-dimensional heart shapes to be expressed as morphometric scores. Those scores show the extent of geometrical shift and can help explore uncharted relationships between vorticity and architecture.

Purpose

We aimed to quantify vorticity, incorporating deep learning to enhance 4D Flow data, and correlate this with global cardiac parameters and morphometric scores.

Methods

12 Adult rToF patients and 10 age-matched controls underwent 4D flow MRI and cine imaging. RV interventricular vorticity was calculated for outflow and inflow tracts. EDV, ESV and SV were computed from cines which were also used to build three-dimensional shape models.

The biventricular models were projected onto an atlas generated from 95 rToF patients, and twenty-one principal component analysis shape modes were correlated with cardiac metrics and vorticity to identify global shape variations. Association between biventricular shape and vorticity was further analysed using multivariate multiple regression models.

Results

Strong correlation was found between PRV and the right ventricular outflow tract (RVOT) vorticity. PRV and RVOT vorticity both correlated with the same 3 shape modes (r=−0.55, −0.50 and 0.6 (p&lt;0.05) respectively for PR and r=0.63, −0.82 and 0.60 (p&lt;0.05) respectively for vorticity) i.e., the RV dilates with an increase in basal bulging, apical bulging and tricuspid annulus tilting with more severe regurgitation, as well as a smaller LV, and a paradoxical movement of the septum (Figure 1). However, RV vorticity correlated with 2 modes that did not correlate with PRV, (r=−0.62, −0.69, p&lt;0.05). With higher vorticity the RV was longer, increased tilting of the tricuspid annulus and an increased basal bulge around the tricuspid area. The multivariate analysis model demonstrated that higher vorticity was associated with displacement of the pulmonary valve and change in the RVOT length and direction. A septal displacement towards the left ventricle was observed and increased apical flatness of the RV (Figure 1). Qualitatively, vorticity in rToF group was more heterogeneous than controls (Figure 2).

Conclusions

Vorticity is a novel marker based on the influence of blood motion providing new insight into early diagnosis and prognosis of cardiac disease. This is the first study to examine the relationships between vorticity and regional RV shape changes in rToF. Mode associations with vorticity were different to associations with PRV. More longitudinal studies are required for standardization of change in vorticity with the disease process.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): The New Zealand heart foundation Mode variations and morphometric modelVorticity visualization and analysis

1020 Delay to Surgery in Acute Perforated and Ischaemic Gastrointestinal Pathology

Introduction

Patients with acute abdominal pathology requiring emergency laparotomy who experience a delay to theatre have an increased risk of morbidity, mortality, and complications. The timeline between symptom onset and operation is ill-defined with international variance in assessment and management. This systematic review aims to define where delays to surgery occur and assess the evidence for previous interventions.

Method

A systematic review was performed searching MEDLINE and EMBASE databases (January 1st 2005 to May 6th 2020). All studies assessing the impact of time to theatre in patients with acute abdominal pathology requiring emergency laparotomy were considered.

Results

Eighty-five results were assessed to include 19 papers in the analysis. Fifteen unique timepoints were identified in the patient pathway between symptom onset and operation which could be classified into four distinct phases. Time from admission to theatre (1 to 72 hours), and mortality rate (10.6-74.5%) varied greatly between studies. Mean time to surgery was significantly higher in deceased patients compared to survivors. Delays were related to imaging, diagnosis, decision-making, theatre availability and staffing. Four of five interventional studies showed a reduced mortality following introduction of an acute laparotomy pathway.

Conclusions

There is wide variation in the definition and measurement of time delays prior to emergency surgery with few studies exploring interventions. Given the heterogenous nature of the patient population and pathologies, an assessment and management framework from onset of symptoms to operation is proposed. This could be incorporated into national mortality prediction and audit tools and assist in the assessment of interventions.

1289 Gender Representation in The Authorship of Surgical Journals

Introduction

Despite the increase in female doctors graduating from medical schools internationally, gender disparity in surgery remains. This disparity is also evident in academic surgery. This study aims to quantify the extent of gender disparity in the authorship of articles in major surgical journals.

Method

The Top 10 Surgical Journals were identified using SCImago Journal Rank indicator. Authorship details for papers published in 2019 were collected. Authors were assigned as female, male or unknown using Gender API software (Gender API, Germany). For each journal, the percentage of first author, last author, corresponding author and all authors split by gender was interrogated. Gender differences by publication type were also identified.

Results

9 of the 10 journals had full names publicly available. Overall, 2414 manuscripts were interrogated which included 16,277 number of authors. Respectively, females and males accounted for 29.8% [22.9-34.9%] (N = 655) and 62.4% [56.3-70.2%] (N = 1419) of first authors, 20.6% [11.8-27.1%] (N = 453) and 74.2% [65.6-84.1%] (N = 1706) of last authors, 23.9% [14.9-29.6%] (N = 510) and 69.9% [60.5-79.3%] (N = 2341) of corresponding authors and in total 27% [19.4-31.6%] (N = 4298) and 65.5% [58.6-73.4%] (N = 9982) of all authors. The wide range in these results could be a result of various factors.

Conclusions

This study has identified a gender imbalance in authorship positions, with the greatest difference observed in the most senior author position. Whether this is reflective of the current disparity observed in senior academic surgery positions or due to gender discrimination is unclear.

1308 Investigating the Use of a Novel Pre-Hospital Triage Tool for Acute Abdominal Surgical Emergencies – A Two-Phase Single Centre Cohort Study

Background

Despite the recent improvements in mortality in patients undergoing emergency laparotomy(EL) within the UK, delay to theatre continues to be associated with increased mortality. This study aimed to assess if patients requiring urgent surgical intervention for acute abdominal surgical pathology could be identified in the pre-hospital setting.

Method

A two-phase, single-centre, cohort study was performed. Phase 1 retrospectively investigated patients who underwent emergency laparotomy between 01/01/2019-31/12/2019 at Leeds Teaching Hospital Trust (LTHT) through the NELA database. Phase 2 prospectively assessed NEWS2 for all patients presenting to LTHT Surgical Admissions Unit with abdominal pain between 01/01/2020-31/01/2020.

Results

Phase 1: 45 patients were coded through NELA and confirmed through operation note review as undergoing EL for gastrointestinal perforation. 66%(n = 30) were assessed by the ambulance service and 80% (n = 24) had a NEWS2 of 3 or greater. Phase 2: 319 patients were assessed in SAU/ED, of which 69 initially treated by the ambulance service. 30% (n = 21) of these patients had an initial NEWS2 of 3 or above. Sensitivity of a NEWS2 score of &gt;/3 in predicting the need for immediate surgical intervention including EL was 95%(95%CI, 74-99) and specificity was 95% (95%CI, 83-99) with a PPV of 86%(95%CI 67-95) and NPV of 98% (95%CI, 87-99).

Conclusions

A NEWS2 score of &gt;/3 predicts the need for emergency surgical intervention including laparotomy for gastrointestinal perforation with reasonable sensitivity in this cohort. A pre-hospital triage tool for patients presenting with abdominal pain could utilise NEWS2 as an adjunct to decision-making in an acute abdominal pathway.

1423 Quality and Efficacy of Multidisciplinary Team (MDT) Discussion Quality Assessment Tools and Checklists: A Systematic Review

Aim

MDT discussion is the gold standard for cancer care in the UK. With the cancer incidence and complexity of treatments both increasing, demand for MDT discussion is growing. The need for efficiency, whilst maintaining high standards, is therefore clear. Paper-based MDT quality assessment tools and discussion checklists may represent a practical method of monitoring and improving MDT practice. This review aims to describe and appraise these tools, as well as consider their value to quality improvement.

Method

MEDLINE, Embase and PsycInfo were searched using pre-defined terms. PRISMA methodology was followed throughout. Studies were included if they described the development of a relevant tool/checklist, or if an element of the methodology further informed tool quality assessment. To investigate efficacy, studies using a tool as a method of quality improvement in MDT practice were also included. Study quality was appraised using the COSMIN risk of bias checklist or the Newcastle-Ottawa scale, depending on study type.

Results

The search returned 6888 results. 17 studies were included, and 6 different tools were identified. Overall, methodological quality in tool development was adequate to very good for assessed aspects of validity and reliability. Clinician feedback was positive. In one study, the introduction of a discussion checklist improved MDT ability to reach a decision from 82.2% to 92.7%. Improvement was also noted in the quality of information presented and the quality of teamwork.

Conclusions

Several tools for assessing and guiding MDT discussions are available. Although limited, current evidence indicates sufficient rigour in their development and their potential for quality improvement.

1404 NELA Risk Mortality Scores from Admission to Theatre in Emergency Gastrointestinal Perforation – A Retrospective Cohort Study

Background

Patients with acute abdominal pathology requiring emergency laparotomy who experience a delay to theatre have an increased risk of morbidity, mortality and complications. The aim of this study was to assess delay, from symptom onset to theatre in patients with gastrointestinal perforation and its effect on perioperative risk.

Method

A single-centre retrospective study was performed in the Leeds Trust Hospitals, UK investigating the NELA database for patients requiring emergency laparotomy for perforated gastrointestinal viscus who presented to the acute surgical unit or emergency department between 1st February 2018 and 31st January 2020.

Results

101 patients met the inclusion criteria (47% F and 53% M), mean age 59 [21-91]. 37% of patients’ NELA scores worsened from admission to pre-op (median change of + 5.9% IQR 1.3-11.5]), 14% stayed the same and 49% improved (median change of -4.4%[IQR 0.4-9.1]) 3% had their NELA score documented at the time of consent. 18% did not wait for a CT report or went straight to theatre. Mean time from admission to scan report was 9.3 hours (0.9-22.0). Median time from symptom onset to presentation (2 days [IQR 1-13]) was greater in patients with an Index of Multiple Deprivation Decile of 1-5, (n = 64, median 2 days [IQR 1-6]) compared to those in deciles 6-10, (n = 37, median 1 day[IQR 1-3]), p = 0.097.

Conclusions

NELA mortality risk score changes from presentation to surgery in patients with acute gastrointestinal perforation requiring emergency laparotomy. There is suggestion that delay in symptom onset to presentation may correlate with Index of Multiple Deprivation Decile.

Transdermal delivery of carnosine into equine skeletal muscle

The dipeptide carnosine consists of β-alanine and L-histidine. It plays a major role in skeletal muscle metabolism, especially as an intracellular buffer and antioxidant. Increasing intramuscular carnosine has been shown to improve recovery from exercise and increase anaerobic threshold and time-to-exhaustion. Dietary supplementation with carnosine does not effectively increase intramuscular carnosine due to the presence of carnosinase in the blood. However, an effective transdermal delivery process could expediently increase intramuscular concentrations of carnosine. This study’s objective was to examine the efficacy of a transdermal system for delivering carnosine into the skeletal muscle of horses, using a randomised, placebo controlled, crossover study. Carnosine plus a proprietary transdermal delivery agent or the agent alone (placebo) were applied to the middle gluteal muscles of 10 Thoroughbred racehorses, and muscle biopsies were taken before and 30, 60, and 120 min after application. Muscle carnosine concentration was measured using an enzyme-linked immunosorbent assay. A two-way repeated measures analysis of variance was used to test for the main effects of time and treatment (placebo or carnosine) as well as an interaction between time and treatment. Independent F-tests examined the change in intramuscular carnosine levels from baseline to each time point (30, 60, and 120 min). There was a significant main effect of treatment (P=0.004), no significant main effect for time (P=0.18), and a non-significant interaction of treatment with time (P=0.08). Mean intramuscular carnosine concentrations increased from baseline to 120 min. Compared to concentrations following placebo application, carnosine was greater by ~35% at 30 min (P=0.002) and ~46% after 60 min (P=0.044), but not at 120 min (P=0.20). The results indicated that intramuscular carnosine can be increased using a transdermal delivery system within 60 min of application which could have important implications for the health of horses, and their capacity to perform and recover from physical activity.

Automatic segmentation of the aorta on multi-center and multi-vendor phase-contrast enhanced magnetic resonance angiographies and the advantages of transfer learning

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Guala A. received funding from the Spanish Ministry of Science, Innovation and Universities

Background

Phase-contrast (PC) enhanced magnetic resonance (MR) angiography (MRA) is a class of angiogram exploiting velocity data to increase the signal-to-noise ratio, thus avoiding the administration of external contrast agent, normally used to segment 4D flow MR data. To train deep-learning algorithms to segment PC-MRA a large amount of manually annotated data is needed: however, the relatively novelty of the sequence, its rapid evolution and the extensive time needed to manually segment data limit its availability.

Purpose

The aim of this study was to test a deep learning algorithm in the segmentation of multi-center and multi-vendor PC-MRA and to test if transfer learning (TL) improves performance.

Methods

A large dataset (LD) of 262 and a small one (SD) of 22 PC-MRA, acquired without contrast agent at 1.5 T in a General Electric and a Siemens scanner, respectively, were manually annotated and divided into training (232 and 15 cases) and testing (30 and 7) sets. They both included PC-MRA of healthy subjects and patients with aortic diseases (excluding dissections) and native aorta. A convolutional neural networks (CNN) based on nnU-Net framework [1] was trained in the LD and another in the SD. The left ventricle was removed semi-automatically from the DL segmentations of the LD as it was not relevant for this application. Networks were then tested on the test sets of the dataset there were trained and the other dataset to assess generalizability. Finally, a fine-tuning transfer learning approach was applied to LD network and the performance on both test sets were tested. Dice score, Hausdorff distance, Jaccard score and Average Symmetrical Surface Distance were used as segmentation quality metrics.

Results

LD network achieved good performance in LD test set, with a DS of 0.904, ASSD of 1.47, J of 0.827 and HD of 6.35, which further improve after removing the left ventricle in the post-processing to a DS of 0.942, ASSD of 0.93, J of 0.892 and HD of 3.32. SD network results in an average DS of 0.895, ASSD of 0.59, J of 0.812 and HD of 2.05. Once tested on the testing set of the other dataset, LD network resulted in a DS of 0.612 while SD network in DS of 0.375, thus showing limited generalizability. However, the application of transfer learning to LD network resulted in the improvement of the evaluation metrics on the SD from a DS of 0.612 to 0.858, while slightly worsening in the first one without post-processing to 0.882.

Conclusions

nnU-net framework is effective for fast automatic segmentation of the aorta from multi-center and multi-vendor PC-MRA, showing performance comparable with the state of the art. The application of transfer learning allows for increased generalization to data from center not included in the original training. These results unlock the possibility for fully-automatic analysis of multi-vendor multi-center 4D flow MR.

Delay to surgery in acute perforated and ischaemic gastrointestinal pathology: a systematic review

BACKGROUND

Patients with acute abdominal pathology requiring emergency laparotomy who experience a delay to theatre have an increased risk of morbidity, mortality and complications. The timeline between symptom onset and operation is ill defined with international variance in assessment and management. This systematic review aims to define where delays to surgery occur and assess the evidence for interventions trialled across Europe.

METHODS

A systematic review was performed searching MEDLINE and EMBASE databases (1 January 2005 to 6 May 2020). All studies assessing the impact of time to theatre in patients with acute abdominal pathology requiring emergency laparotomy were considered.

RESULTS

Sixteen papers, involving 50 653 patients, were included in the analysis. Fifteen unique timepoints were identified in the patient pathway between symptom onset and operation which are classified into four distinct phases. Time from admission to theatre (1-72 hours) and mortality rate (10.6-74.5 per cent) varied greatly between studies. Mean time to surgery was significantly higher in deceased patients compared with that in survivors. Delays were related to imaging, diagnosis, decision making, theatre availability and staffing. Four of five interventional studies showed a reduced mortality rate following introduction of an acute laparotomy pathway.

CONCLUSION

Given the heterogeneous nature of the patient population and pathologies, an assessment and management framework from onset of symptoms to operation is proposed. This could be incorporated into mortality prediction and audit tools and assist in the assessment of interventions.

Discrimination in the surgical discipline: an international European evaluation (DISDAIN)

Background

Negative workplace experiences (NWPEs), such as gender discrimination, bullying, sexual harassment and ethnic discrimination, are concerns in today’s surgical society. These negative experiences potentially impair surgeons’ performance and might impact patient care or outcomes negatively. This study aimed to assess the experience of NWPEs across the European surgical workforce.

Methods

A prospective online 34-point questionnaire was designed using a combination of Likert scale, multiple-choice and short-answer questions. Invitations were distributed through surgical associations via email/social media between 1 September and 15 November 2019. Data were analysed using non-parametric methods.

Results

Some 840 complete responses were included in the analysis. The distribution across genders and stage of surgical training was even. Of the respondents, 20 per cent (168 respondents) considered quitting their job, 4.5 per cent (38) took time off and 0.5% (4) left surgery due to NWPEs; 12.9 per cent of females and 4.4 per cent of males experienced some form of physical harassment. Females and those in training were significantly more likely to experience or witness gender discrimination and sexual harassment. Just over half of the respondents (448) did not report negative experiences, with most of these (375 respondents) being unaware of whom to report to. Nearly a fifth of respondents felt that NWPEs influenced patient care or outcomes negatively.

Conclusion

NWPEs were frequent, especially among females and those in training. While a substantial proportion of respondents experienced physical harassment, many individuals were unaware of how to raise concerns. Adverse effects on patient outcomes, surgical training and workforce retention indicate a need for urgent action.

POS0495 LARGE JOINT DISEASE IN RHEUMATOID ARTHRITIS AND THE ROLE OF RHEUMATOID FACTOR. RESULTS FROM THE EARLY RHEUMATOID ARTHRITIS STUDY

Background:

Rheumatoid arthritis (RA) is classically described as a symmetric small joint polyarthritis with additional involvement of large joints. There is a paucity of information concerning the time course of damage in large joints, such as shoulder, elbow, hip, knee and ankle, from early to established RA, or of the influence of Rheumatoid Factor (RF) status. There is a historic perception that patients who do not have RF follow a milder less destructive course, which might promote less aggressive treatment strategies in RF-negative patients. The historic nature of the Ealy Rheumatoid Arthritis Study (ERAS) provides a unique opportunity to study RA in the context of less aggressive treatment strategies.

Objectives:

To examine the progression of large joint involvement from early to established RA in terms of range of movement (ROM) and time to joint surgery, according to the presence of RF.

Methods:

ERAS was a multi-centre inception cohort of newly diagnosed RA patients (<2 years disease duration, csDMARD naive), recruited from 1985-2001 with yearly follow-up for up to 25 (median 10) years. First line treatment was csDMARD monotherapy with/without steroids, favouring sulphasalazine for the majority. Outcome data was recorded at baseline, at 12 months and then once yearly. Patients were deemed RF negative if all repeated assessments were negative. ROM of individual shoulder, elbow, wrist, hip, knee, ankle and hindfeet joints was collected at 3, 5, 9 and 12-15 years. The rate of progression from normal to any loss of ROM, from years 3 to 14 was modelled using GEE, adjusting for confounders. Radiographs of wrists taken at years 0, 1, 2, 3, 5, 7, 9 were scored according to the Larsen method. Change in the Larsen wrist damage score was modelled using GEE as a continuous variable, while the erosion score was dichotomised into present/absent. Surgical procedure data were obtained by linking to Hospital Episodes Statistics and the National Joint Registry. Time to joint surgery was analysed using multivariable Cox models.

Results:

A total of 1458 patients from the ERAS cohort were included (66% female, mean age 55 years) and 74% were RF-positive. The prevalence of any loss of ROM, from year 3 through to 14 was highest in the wrist followed by ankle, knee, elbow and hip. The proportion of patients at year 9 with greater than 25% loss of ROM was: wrist 30%, ankle 12%, elbow 7%, knee 7% and hip 5%. Odds of loss of ROM increased over time in all joint regions, at around 7 to 13% per year from year 3 to 14. There was no significant difference between RF-positive and RF-negative patients (see Figure 1). Larsen erosion and damage scores at the wrists progressed in all patients; annual odds of developing any erosions were higher in RF-positives OR 1.28 (95%CI 1.24-1.32) than RF-negatives OR 1.17 (95%CI 1.09-1.26), p 0.013. Time to surgery was similar according to RF-status for the wrist and ankle, but RF-positive cases had a lower hazard of surgery at the elbow (HR 0.37, 0.15-0.90), hip (HR 0.69, 0.48-0.99) and after 10 years at the knee (HR 0.41, 0.25-0.68). Adjustment of the models for Lawrence assessed osteoarthritis of hand and feet radiographs did not influence these results.

Figure 1.

Odds of progression to any loss of ROM (from no loss of ROM) per year in the overall population and stratified by RF status.

Conclusion:

Large joints become progressively involved in RA, most frequently affecting the wrist followed by ankle, which is overlooked in some composite disease activity indices. We confirm a higher burden of erosions and damage at the wrists in RF-positive patients, but have not found RF-negative patients to have a better prognosis over time with respect to involvement of other large joints. In contrast RF-negative patients had more joint surgery at the elbow, hip, and knee after 10 years. There is no justification to adopt a less aggressive treatment strategy for RF-negative RA. High vigilance and treat-to-target approaches should be followed irrespective of RF status.

Disclosure of Interests:

None declared

Routine antiseptic baths and MRSA decolonization: diverse approaches across Singapore's acute-care hospitals

To determine the variation in practices on meticillin-resistant Staphylococcus aureus (MRSA) surveillance and management of MRSA-colonized patients amongst 17 acute healthcare facilities in Singapore, the Ministry of Health convened a sharing session with Infection Prevention and Control Leads. All hospitals practised close to universal MRSA entry swabbing in keeping with national policy. There were, however, major variations in the response to both positive and negative surveillance swabs across facilities including the role of routine antiseptic bathing and MRSA decolonization. Most undertaking decolonization considered its role to be in 'bioburden reduction' rather than longer-term clearance.

Bipolar affective disorder

Abstract Body

Abstract: Biomarkers for diagnosis and treatment of Bipolar Disorder: hope or hype? Professor Allan Young, Centre for Affective Disorders, IoPPN, KCL London, SE5 8AF. allan.young@kcl.ac.uk The use of “biomarkers” (biological markers) in basic and clinical research as well as in clinical practice has become so commonplace in many areas of medicine that their presence as primary endpoints in clinical trials is now widely accepted. In clinical disciplines where specific biomarkers have been well characterized and repeatedly shown to correctly predict relevant clinical outcomes across a variety of treatments and populations, this use is entirely justified and appropriate. However, the validity of biomarkers in most psychiatric disorders continues to be evaluated. This lecture will review the current conceptual status of biomarkers as clinical and diagnostic tools for bipolar disorder and as surrogate endpoints in clinical research in bipolar disorder. The conceptual background in terms of current diagnostic categories and research domain criteria will be discussed and the various approaches with putative value (e.g., brain imaging, genetics, and neuroendocrinology) reviewed (1, 2). The lecture will end with a discussion of approaches to evaluating biomarkers of lithium response (3).

References

Wise et al, Mol Psychiatry. 2016 May 24. doi: 10.1038/mp.2016.72. [Epub ahead of print]; Young AH. Harv Rev Psychiatry. 2014 Nov-Dec;22(6):331–3 Bellivier F, Young AH, et al, Bipolar Disord. 2020 Oct 23. doi: 10.1111/bdi.13023. Online ahead of print.

Disclosure

Paid lectures and advisory boards for the following companies with drugs used in affective and related disorders: Astrazenaca, Eli Lilly, Lundbeck, Sunovion, Servier, Livanova, Janssen, Allegan, Bionomics, Sumitomo Dainippon Pharma, COMPASS Principal Inve

The strain-7 study: multimodal, multivendor, multifield strength, scan:rescan comparison of global longitudinal and circumferential strain in healthy volunteers

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): National Insitute for Health Research

Background

There is clinical and prognostic evidence for global longitudinal strain (GLS) and circumferential strain (GCS). A range of techniques exist: 2-dimensional echocardiography (2Decho), 3-dimensional echocardiography (3Decho) and Cardiovascular Magnetic Resonance (CMR).

Purpose

To investigate inter-study repeatability and inter-method comparison of GLS and GCS techniques.

Methods

Volunteers underwent same day scan

rescan 2Decho, 3Decho, 1.5T Siemens CMR (Cine imaging and Displacement encoding with stimulated echoes [DENSE]), 3T Siemens CMR (Cine Imaging and DENSE) and 3T Philips CMR (Tagging and Fast strain-encoding [fSENC]) imaging. Strain was quantified for 2Decho (EchoPAC), 3Decho (TomTec), Feature tracking (FT) for cine imaging (CircleCVI), CIM (University of Auckland) for DENSE and Tag, and Myostrain (Myocardial solutions) for fSENC.

Results

20(6F) volunteers, mean age 33 ± 7 years, mean LVEF 62 ± 4%. All GLS and GCS methods had excellent inter-study agreement (ICC &gt; 0.75) with coefficient of variation (CoV) between 4-8% (Table 1). Median and IQR are presented in Figure 1.

Friedman’s test revealed statistically significant inter-method differences for GLS (χ2 = 66.4,p &lt; 0.0001) and GCS (χ2 = 50.9,p &lt; 0.0001). Post hoc analysis using Dunn’s test with Bonferroni correction demonstrated significant differences:

-GLS: 2Decho vs DENSE 1.5T (p = 0.001) and Myostrain 3T (p = 0.0116); 3Decho vs FT 3T (p = 0.049) and DENSE 1.5T (p &lt; 0.0001); FT 1.5T vs DENSE 1.5T (p = 0.001) and Myostrain 3T (p = 0.01); FT 3T vs Myostrain 3T (p &lt; 0.0001); DENSE 1.5T vs Tag 3T (p = 0.0008) and Myostrain 3T (p &lt; 0.0001); Tag 3T vs Myostrain (p = 0.02).

-GCS: 3Decho vs DENSE 1.5T (P = 0.0005), FT 1.5T (p &lt; 0.001), FT 3T (P &lt; 0.001) and Myostrain (p = 0.003); FT 1.5T vs Tag 3T (p = 0.001), FT 3T vs Myostrain 3T (p = 0.04).

Conclusion

There is excellent interstudy agreement for GLS and GCS methods. However, there are important inter-method differences in absolute values, that need to be considered for clinical application as a surveillance method and longitudinal studies.

Table 1 Acquisiton Post processing GLS CoV(%) GLS ICC GCS CoV(%) GCS ICC 2DEcho EchoPAC 4.88 0.80 - - 3DEcho TomTec 4.77 0.86 3.97 0.85 Siemens 1.5T cine FT CircleCVI 8.30 0.79 6.00 0.85 Siemens 3T cine FT CircleCVI 6.21 0.89 4.76 0.94 Philips 3T Tag CIM 6.15 0.89 5.86 0.88 Siemens 1.5T DENSE CIM 4.36 0.90 4.65 0.89 Philips 3T fSENC Myostrain 8.45 0.81 4.06 0.90 Interstudy agreement for the different GLS and GCS methods. Abstract Figure 1

Patient-reported experiences of mealtime care and food access in acute and rehabilitation hospital settings: a cross-sectional survey

BACKGROUND

Nutrition and mealtime interventions can improve nutritional intake amongst hospital inpatients; however, patient-reported experience is rarely considered in their development and evaluation. The present study aimed to measure patient-reported food and mealtime experience to evaluate and inform continuous quality improvement of hospital nutrition care.

METHODS

A cross-sectional survey with inpatients in seven acute care and rehabilitation wards was conducted. A 27-item validated questionnaire measured five domains of patient experience: food choices, organisational barriers, feeling hungry, physical barriers to eating and food quality. Responses were summarised descriptively and compared between settings (acute versus rehabilitation), patient demographics (age, gender) and time in hospital.

RESULTS

Responses from 143 participants (mean age 67 years, 57% male, 28% rehabilitation, median 6 days into hospitalisation) showed that 10% or fewer respondents reported difficulties with food choices, feeling hungry or food quality. The most common difficulties were opening packets (36%), insufficient menu information provided (29%), being interrupted by staff when eating (28%), being disturbed when eating (27%), being in an uncomfortable position when eating (24%) and difficulty reaching food (21%). There were no significant differences in domain patterns by sex, age group or time in hospital. Organisational barriers were reported less frequently amongst rehabilitation participants compared to acute care (P = 0.01).

CONCLUSIONS

This survey highlights areas of positive patient-reported experience with nutrition care and suggests that local improvement efforts should focus on physical assistance needs and organisational barriers, especially in acute care wards. The questionnaire may be useful for informing and evaluating systematic nutrition care improvements.