Assessing Evidence-Based Practice Knowledge, Self-Efficacy, and Use Among Respiratory Therapists

BACKGROUND

Evidence-based practice is at the forefront of providing quality patient care by using the best available evidence and clinical expertise, while also considering patient needs and preferences for clinical decisions. However, evidence-based practice may not be consistently used even when the evidence supports the therapy. The purpose of this study was to assess the factors associated with the use of evidence-based practice among respiratory therapy faculty teaching in a large community college system and post-professional students enrolled in a university-based, respiratory therapy baccalaureate degree-advancement program.

METHODS

A non-probability, descriptive survey research design was used to develop and administer an online questionnaire.

RESULTS

All respondents demonstrated sufficient knowledge and understanding of introductory concepts of evidence-based practice but knowledge of specific components of the evidence-based practice process was not as strong. Self-efficacy in knowledge and the use of evidence-based practice among faculty and degree-advancement students varied. Faculty and students rated their self-efficacy high in assessing patients' needs, values, and treatment preferences but ratings were lower for using the PICO (patient/population/problem, intervention, comparison, outcome) technique and interpreting common statistical tests. Students viewed their previous evidence-based practice learning experiences more favorably compared with faculty (P = .008). Faculty and students searched and read the research literature more often compared with critically appraising and using the research literature. Logistic regression analysis indicated no statistically significant relationship of knowledge, self-efficacy, and learning experiences to the use of evidence-based practice among respiratory therapy students, Χ 2 (4, N = 54) = 7.73; P = .10.

CONCLUSIONS

Analysis of the results suggested that respiratory therapy faculty and students were knowledgeable and confident with regard to evidence-based practice but their use of evidence-based practice in clinical decisions was limited. Although the evidence-based practice knowledge, self-efficacy, and learning experiences had minimal influence on the use of evidence-based practice, the results of the study provide a foundation for future research.

Beyond scale-free networks: integrating multilayer social networks with molecular clusters in the local spread of COVID-19

This study evaluates the scale-free network assumption commonly used in COVID-19 epidemiology, using empirical social network data from SARS-CoV-2 Delta variant molecular local clusters in Houston, Texas. We constructed genome-informed social networks from contact and co-residence data, tested them for scale-free power-law distributions that imply highly connected hubs, and compared them to alternative models (exponential, log-normal, power-law with exponential cutoff, and Weibull) that suggest more evenly distributed network connections. Although the power-law model failed the goodness of fit test, after incorporating social network ties, the power-law model was at least as good as, if not better than, the alternatives, implying the presence of both hub and non-hub mechanisms in local SARS-CoV-2 transmission. These findings enhance our understanding of the complex social interactions that drive SARS-CoV-2 transmission, thereby informing more effective public health interventions.

Late gadolinium enhancement and the risk of ventricular arrhythmias and sudden death in NYHA class I patients with non-ischaemic cardiomyopathy

AIM

To compare the risk of ventricular arrhythmias (VA) and sudden death (SD) between New York Heart Association (NYHA) class I and NYHA class II-III patients with non-ischaemic cardiomyopathy (NICM).

METHODS AND RESULTS

Observational retrospective cohort study including patients with NICM who underwent cardiac magnetic resonance at two hospitals. The primary endpoint included appropriate implantable cardioverter defibrillator (ICD) therapies, sustained ventricular tachycardia, resuscitated cardiac arrest and SD. The secondary endpoint included heart failure (HF) hospitalizations, heart transplant, left ventricular assist device implant or HF death. Overall, 698 patients were included, 33% in NYHA class I. During a median follow-up of 31 months, the primary endpoint occurred in 57 patients (8%), with no differences between NYHA class I and NYHA class II-III cases (7% vs. 9%, p = 0.62). Late gadolinium enhancement (LGE) was the only independent predictor of the primary outcome both in NYHA class I and NYHA class II-III patients. LGE+ NYHA class I patients had a similar cumulative incidence of the primary endpoint as compared to LGE+ NYHA class II-III (p = 0.92) and a significantly higher risk as compared to LGE- NYHA class II-III cases (p < 0.001). The risk of the secondary endpoint was significantly higher in patients in NYHA class II-III as compared to those in NYHA class I (hazard ratio 3.2, p = 0.001).

CONCLUSIONS

Patients with NICM in NYHA class I are not necessarily at low risk of VA and SD. Actually, LGE+ NYHA class I patients have a high risk. NYHA class I patients with high-risk factors, such as LGE, could benefit from primary prevention ICD at least as much as those in NYHA class II-III with the same risk factors.

A personal journey to build leadership skills through collaboration to support radiography research and evidence-based practice

Introduction

The Covid-19 pandemic continues to impact on how radiotherapy is delivered, how staff do their job and how patients are cared for. Part of the UK NHS response to the covid-19 crisis was to accelerate final year radiotherapy students into work as therapeutic radiographers. The study objective is to explore the experiences of a cohort of new registrants who started work in May 2020.

Methods

In depth interviews were conducted remotely with newly qualified therapeutic radiography registrants regarding their first 12 months working in UK NHS cancer centres. Data were analysed within and across cases using a framework analysis and synthesised thematically.

Results

Eleven radiographers were interviewed, working across six different sites. Key generated themes are the risk of impaired professional socialisation due to incongruence between students’ expectations and the reality in clinical departments. We use Bridges Transitional Model to show how a combination of the disrupted/undefined end to university and a perceived lack of recognition of professional knowledge, skills and values evident in our data may leave participants stuck in a middle stage of the transition process. Slower than expected professional development led to demotivation, which was also associated with rising covid-19 case numbers.

Conclusion

The covid-19 pandemic accentuated and heightened the existing challenge of professional integration and socialisation faced by new therapeutic radiography staff. Demotivation and potentially attrition are more likely in this environment. Compassionate leadership that fosters the mentorship of junior cohorts as part of a flexible preceptorship package could mitigate these risks.

Direct comparison of RT-ddPCR and targeted amplicon sequencing for SARS-CoV-2 mutation monitoring in wastewater

Over the course of the COVID-19 pandemic, variants of SARS-CoV-2 have emerged that are more contagious and more likely to cause breakthrough infections. Targeted amplicon sequencing approach is a gold standard for identification and analysis of variants. However, when applied to environmental samples such as wastewater, it remains unclear how sensitive this method is for detecting variant-associated mutations in environmental samples. Here we directly compare a targeted amplicon sequencing approach (using ARTIC v3; hereafter referred to as sequencing) with RT-ddPCR quantification for the detection of five mutations that are characteristic of variants of concern (VoCs) in wastewater samples. In total, 547 wastewater samples were analyzed using both methods in parallel. When we observed positive mutation detections by RT-ddPCR, 42.6% of the detection events were missed by sequencing, due to negative detection or the limited read coverage at the mutation position. Further, when sequencing reported negative or depth-limited mutation detections, 26.7% of those events were instead positive detections by RT-ddPCR, highlighting the relatively poor sensitivity of sequencing. No or weak associations were observed between quantitative measurements of target mutations determined by RT-ddPCR and sequencing. These findings caution the use of quantitative measurements of SARS-CoV-2 variants in wastewater samples determined solely based on sequencing.

Direct comparison of RT-ddPCR and targeted amplicon sequencing for SARS-CoV-2 mutation monitoring in wastewater

Over the course of the COVID-19 pandemic, variants of SARS-CoV-2 have emerged that are more contagious and more likely to cause breakthrough infections. Targeted amplicon sequencing approach is a gold standard for identification and analysis of variants. However, when applied to environmental samples such as wastewater, it remains unclear how sensitive this method is for detecting variant-associated mutations in environmental samples. Here we directly compare a targeted amplicon sequencing approach (using ARTIC v3; hereafter referred to as sequencing) with RT-ddPCR quantification for the detection of five mutations that are characteristic of variants of concern (VoCs) in wastewater samples. In total, 547 wastewater samples were analyzed using both methods in parallel. When we observed positive mutation detections by RT-ddPCR, 42.6% of the detection events were missed by sequencing, due to negative detection or the limited read coverage at the mutation position. Further, when sequencing reported negative or depth-limited mutation detections, 26.7% of those events were instead positive detections by RT-ddPCR, highlighting the relatively poor sensitivity of sequencing. No or weak associations were observed between quantitative measurements of target mutations determined by RT-ddPCR and sequencing. These findings caution the use of quantitative measurements of SARS-CoV-2 variants in wastewater samples determined solely based on sequencing.

Two Epidemics and a Pandemic: The Collision of Prescription Drug Misuse and Racism during COVID-19

The present study investigated the relationship between perceived racial discrimination and prescription drug misuse (PDM) among Asian, Black, and Latinx Americans during the COVID-19 crisis. U.S. racial/ethnic minorities may have been uniquely affected by two national and one global pandemic: the opioid crisis, racism, and COVID-19. Opioid death rates increased among many groups prior to the pandemic. This country witnessed an increase in racialized acts against people of color across the spectrum in the spring and summer months of the world's COVID-19 outbreak. While studies have shown a clear link between perceived racial discrimination and substance abuse outside of the global pandemic, no identified studies have done so against the backdrop of a global health pandemic. Separate hierarchical regressions revealed a significant association between perceived racial discrimination and PDM for Black Americans, Asian Americans, and Latinx individuals. Findings build on the scant literature on PDM in diverse samples and establish a relationship between perceived racial discrimination and PDM, as previously identified for other abused substances. Future post-pandemic substance misuse interventions should consider the influence of perceived racial discrimination as they help individuals recover from the aftermath of this stressful trifecta.

Use of spatio-temporal habitat suitability modelling to prioritise areas for common carp biocontrol in Australia using the virus CyHV-3

Common carp (Cyprinus carpio) are an invasive species of the rivers and waterways of south-eastern Australia, implicated in the serious decline of many native fish species. Over the past 50 years a variety of control options have been explored, all of which to date have proved either ineffective or cost prohibitive. Most recently the use of cyprinid herpesvirus 3 (CyHV-3) has been proposed as a biocontrol agent, but to assess the risks and benefits of this, as well as to develop a strategy for the release of the virus, a knowledge of the fundamental processes driving carp distribution and abundance is required. To this end, we developed a novel process-based modelling framework that integrates expert opinion with spatio-temporal datasets via the construction of a Bayesian Network. The resulting weekly networks thus enabled an estimate of the habitat suitability for carp across a range of hydrological habitats in south-eastern Australia, covering five diverse catchment areas encompassing in total a drainage area of 132,129 km² over a period of 17-27 years. This showed that while suitability for adult and subadult carp was medium-high across most habitats throughout the period, nevertheless the majority of habitats were poorly suited for the recruitment of larvae and young-of-year (YOY). Instead, high population abundance was confirmed to depend on a small number of recruitment hotspots which occur in years of favourable inundation. Quantification of the underlying ecological drivers of carp abundance thus makes possible detailed planning by focusing on critical weaknesses in the population biology of carp. More specifically, it permits the rational planning for population reduction using the biocontrol agent, CyHV-3, targeting areas where the total population density is above a "damage threshold" of approximately 100 kg/ha.

OP0033 REGULATORY T CELL CD39 EXPRESSION AS A PREDICTOR OF EARLY REMISSION-INDUCTION WITH METHOTREXATE IN NEW-ONSET RHEUMATOID ARTHRITIS

Background:

The long term outcomes for patients with rheumatoid arthritis (RA) depend on early and effective disease control. Methotrexate remains the key first line disease modifying therapy for the majority of patients, with 40% achieving an ACR50 on monotherapy(1). There are at present no effective biomarkers to predict treatment response, preventing effective personalisation of therapy. A putative mechanism of action of methotrexate, the potentiation of anti-inflammatory adenosine signalling, may inform biomarker discovery. By antagonism of the ATIC enzyme in the purine synthesis pathway, methotrexate has been proposed to increase the release of adenosine moieties from cells, which exert an anti-inflammatory effect through interaction with ADORA2 receptors(2). Lower expression of CD39 (a cell surface 5-’ectonucleotidase required for the first step in the conversion of ATP to adenosine) on circulating regulatory T-Lymphocytes (Tregs) was previously identified in patients already established on methotrexate who were not responding (DAS28 >4.0 vs <3.0)(3). We therefore hypothesised that pre-treatment CD39 expression on these cells may have clinical utility as a predictor of early methotrexate efficacy.

Objectives:

To characterise CD39 expression in peripheral blood mononuclear cells in RA patients naïve to disease modifying therapy commencing methotrexate, and relate this expression to 4 variable DAS28CRP remission (<2.6) at 6 months.

Methods:

68 treatment naïve early RA patients starting methotrexate were recruited from the Newcastle Early Arthritis Clinic and followed up for 6 months. Serial blood samples were taken before and during methotrexate therapy with peripheral blood mononuclear cells isolated by density centrifugation. Expression of CD39 by major immune subsets (CD4+ and CD8+ T-cells, B-lymphocytes, natural killer cells and monocytes) was determined by flow cytometry. The statistical analysis used was binomial logistic regression with baseline DAS28CRP used as a covariate due to the significant association of baseline disease activity with treatment response.

Results:

Higher pre-treatment CD39 expression was observed in circulating CD4+ T-cells of patients who subsequently achieved clinical remission at 6 months versus those who did not (median fluorescence 4854.0 vs 3324.2; p = 0.0108; Figure 1-A). This CD39 expression pattern was primarily accounted for by the CD4+CD25 high sub-population (median fluorescence 9804.7 vs 6455.5; p = 0.0065; Figure 1-B). These CD25 high cells were observed to have higher FoxP3 and lower CD127 expression than their CD39 negative counterparts, indicating a Treg phenotype. No significant associations were observed with any other circulating subset. A ROC curve demonstrates the discriminative utility of differential CD39 expression in the CD4+CD25 high population for the prediction of DAS28CRP remission in this cohort, showing greater specificity than sensitivity for remission prediction(AUC: 0.725; 95% CI: 0.53 - 0.92; Figure 1-C). Longitudinally, no significant induction or suppression of the CD39 marker was observed amongst patients who did or did not achieve remission over the 6 months follow-up period.

Figure 1.

Six month DAS28CRP remission versus pre-treatment median fluorescence of CD39 expression on CD4+ T-cells (A); CD25 High expressing CD4+ T-cells (B); and ROC curve of predictive utility of pre-treatment CD39 expression on CD25 High CD4+ T-cells (C).

Conclusion:

These findings support the potential role of CD39 in the mechanism of methotrexate response. Expression of CD39 on circulating Tregs in treatment-naïve RA patients may have particular value in identifying early RA patients likely to respond to methotrexate, and hence add value to evolving multi-parameter discriminatory algorithms.

References:

[1]Hazlewood GS, et al. BMJ. 2016 21;353:i1777

[2]Brown PM, et al. Nat Rev Rheumatol. 2016;12(12):731-742

[3]Peres RS, et al. Proc Natl Acad Sci U S A. 2015;112(8):2509-2514

Disclosure of Interests:

None declared

POS0348 GENETIC SUSCEPTIBILITY VARIANTS FOR RHEUMATOID ARTHRITIS ARE NOT ASSOCIATED WITH EARLY REMISSION; A MULTI-COHORT STUDY

Background:

Patients who achieve remission promptly could have a specific genetic risk profile that supports regaining immune tolerance. The identification of these genes could provide novel drug targets.

Objectives:

To test the association between RA genetic risk variants with achieving remission at 6 months.

Methods:

We computed genetic risk scores (GRS) comprising of the RA susceptibility variants1 and HLA-SE status separately in 4425 patients across eight datasets from inception cohorts. Remission was defined as DAS28CRP<2.6 at 6 months. Missing DAS28CRP values in patients were imputed using predictive mean matching by MICE. We first tested whether baseline DAS28CRP changed with increasing GRS using linear regression. Next, we calculated odds ratios for GRS and HLA-SE on remission using logistic regression. Heterogeneity of the outcome between datasets was mitigated by running inverse variance meta-analysis.

Results:

Evaluation of the complete dataset, baseline clinical variables did not differ between patients achieving remission and those who did not (Table 1). Distribution of GRS was consistent between datasets. Neither GRS nor HLA-SE was associated with baseline DAS2DAS (OR1.01; 95% CI 0.99-1.04). A fixed effect meta-analysis (Figure 1.) showed no significant effect of the GRS (OR 0.99; 95% CI 0.94-1.03) or HLA-SE (OR 0.8CRP87; 95% CI 0.75-1.01) on remission at 6 months.

Table 1.

Summary of the data separated by disease activity after 6 months.

allRemission at 6 monthsNo remission at 6 monthsN4425*15582430Age, mean (sd)55.38 (13.87)5517 (14.09)55.62 (13.59)Female %68.98%65.43%70.73%ACPA+ %61.94%63.53%61.67%Baseline DAS28, mean (sd)4.76 (1.22)4.47 (1.23)5.1 (1.15)

*not all patients had 6 months data

Conclusion:

In these combined cohorts, RA genetics risk variants are not associated with early disease remission. At baseline there was no difference in genetic risk between patients achieving remission or not. Studies encompassing other genetic variants are needed to elucidate the genetics of RA remission.

References:

[1]Knevel R et al. Sci Transl Med. 2020;12(545):eaay1548.

Acknowledgements:

This project has received funding from the Innovative Medicines Initiative 2 Joint Undertaking under grant agreement No 777357, RTCure.

This project has received funding from Pfizer Inc.

Disclosure of Interests:

Samantha Jurado Zapata: None declared, Marc Maurits: None declared, Yann Abraham Employee of: Pfizer, Erik van den Akker: None declared, Anne Barton: None declared, Philip Brown: None declared, Andrew Cope: None declared, Isidoro González-Álvaro: None declared, Carl Goodyear: None declared, Annette van der Helm - van Mil: None declared, Xinli Hu Employee of: Pfizer, Thomas Huizinga: None declared, Martina Johannesson: None declared, Lars Klareskog: None declared, Dennis Lendrem: None declared, Iain McInnes: None declared, Fraser Morton: None declared, Caron Paterson: None declared, Duncan Porter: None declared, Arthur Pratt: None declared, Luis Rodriguez Rodriguez: None declared, Daniela Sieghart: None declared, Paul Studenic: None declared, Suzanne Verstappen: None declared, Leonid Padyukov: None declared, Aaron Winkler Employee of: Pfizer, John D Isaacs: None declared, Rachel Knevel Grant/research support from: Pfizer

Expectations of therapeutic radiography students in Wales about transitioning to practice during the Covid-19 pandemic as registrants on the HCPC temporary register

INTRODUCTION

The Covid-19 crisis continues to profoundly impact on radiotherapy practice in the UK. We explore the views of therapeutic radiographer students on entering their first post in unique circumstances as a means to evaluate the support that may minimise negative impacts on their transition to practitioners.

METHOD

Focus groups were conducted outside of students' final year educational programme and immediately prior to them starting work. Qualitative data were analysed using a framework analysis.

RESULTS

Emergent themes from the eleven participants were: Covid-19 as a layer on top of underlying anxieties; Degree of readiness for imminent psychological, emotional and practical challenges; Feeling valued as a health professional/radiographer at this time; A mixed student and qualified staff professional identity as HCPC temporary registrants.

CONCLUSION

Uncertainties related to Covid-19 were seen to add a destabilising component to existing anxieties and challenges. In this context, there are significant risks of impaired professional socialisation due to incongruence between students' expectations and the reality in clinical departments.

IMPLICATIONS FOR PRACTICE

Informed academic support and flexible clinical preceptorship that address anxieties and congruence barriers are vital to guide new practitioners through a health crisis that presents significant challenges but also opportunity for professional development.

Influence of Lipophilicity on the Antibacterial Activity of Polymyxin Derivatives and on Their Ability to Act as Potentiators of Rifampicin

Novel polymyxin derivatives are often classified either as having direct activity against Gram-negative pathogens or as compounds inactive in their own right, which through permeabilization of the outer membrane act as potentiators of other antibiotics. Here, we report the systematic investigation of the influence of lipophilicity on microbiological activity (including against strains with reduced susceptibility to polymyxins), potentiation of rifampicin, and in vitro toxicity within a series of next-generation polymyxin nonapeptides. We demonstrate that the lipophilicity at the N-terminus and amino acids 6 and 7 in the cyclic peptide core is interchangeable and that the activity, ability to potentiate, and cytotoxicity all appear to be primarily driven by overall lipophilicity. Our work also suggests that the characterization of a polymyxin molecule as either a direct acting compound or a potentiator is more of a continuum that is strongly influenced by lipophilicity rather than as a result of fundamentally different modes-of-action.

Abstract SP020: Beyond Hormones: Newer Pharmacologic Approaches

It is now possible to prevent many breast cancers inhigh-risk women using anti-estrogen hormonal drugs. Several Phase III breast cancer preventiontrials demonstrated that hormonal drugs such as the “selective estrogenreceptor modulators” tamoxifen and raloxifene, and aromatase inhibitors preventthe development of 50% of ER-positive breast cancers in women. However, mostwomen at high risk of breast cancer do not use these cancer preventive drugsdue to concerns about their side effects. To overcome this problem, recent studies havefocused on testing novel approaches for the prevention of breast cancer. Results of preclinical and clinical studiestesting targeted drugs and vaccines for breast cancer prevention show that itis possible to prevent breast cancer with reduced toxicity. Studies seeking to prevent all forms ofbreast cancer, including ER-positive, HER2-positive, and “triple-negative”breast cancer, will be presented and discussed. Novel approaches testing targeted therapies including signalinginhibitors, combinations of preventive agents, and vaccines, will be presented. Many of these interventions prevent breastcancer in animal models, and are now being tested in human clinicaltrials. Results from studies testing novel drugdelivery approaches will also be discussed. Topical gels containing anti-estrogen drugs are being used to reducebreast cell growth and mammographic density in Phase II clinical trials. This topical approach has the potential toprevent ER-positive breast cancers without the toxicity of oral hormonaldrugs. All of these novel preventive measuresoffer great promise to effectively prevent all forms of breast cancer withminimal toxicity.

Citation Format: P Brown. Beyond Hormones: Newer Pharmacologic Approaches [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr SP020.

Survey of research participation amongst UK radiology trainees: aspirations, barriers, solutions and the Radiology Academic Network for Trainees (RADIANT)

AIM

To inform the activity of the newly formed Radiology Academic Network for Trainees (RADIANT) regarding the current level of interest, engagement, and barriers experienced by UK radiology trainees to undertake research.

MATERIALS AND METHODS

A web-based survey containing nine questions was sent to the UK radiology training programme directors for distribution to trainees. The survey was also distributed to all trainee members of the RADIANT network. This led to 224 responses over a period of 2 months.

RESULTS

A large proportion of respondents indicated a desire to participate in research in the next 12 months 72.3% (n=162). The most frequently reported barriers to research were lack of time (60.7%, n=136), lack of awareness of local/departmental opportunities (53.6%, n=120), and limited experience in research statistics (46%, n=103). The most favoured factor that would improve access to research was structured research training opportunities, qualified as a project with clear goals and timeline (71%, n=159), protected time for research (68.8%, n=154), and local or national trainee research networks (40.2%, n=90 and 37.1%, n=83, respectively).

CONCLUSION

Many radiology trainees would like to participate in research, but multiple barriers exist. The formation of RADIANT is seen as a key part of a multifaceted approach to improving access to quality research activity alongside support from local and regional training bodies.

Risk stratification and prognostic value of CMR in DCM; parametric mapping and GLS- value beyond EF and LGE?

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Dr Pamela Brown was suppoerted by funding from Alliance Medical.

Background; Arrhythmia risk stratification and device implantation in dilated cardiomyopathy (DCM) poses significant challenges and as demonstrated by the DANISH trial appears to have reached the asymptote of clinical efficacy. A body of evidence now demonstrates that risk stratification of and device selection for DCM patients may be enhanced by inclusion of patients" LGE-status. Furthermore, it has been suggested that CMR based parametric mapping and strain analysis may further advance risk stratification.

Methods; 703 patients with DCM undergoing clinically indicated CMR scans and prospectively enrolled into the UHSM-CMR study (NCT02326324) between 03/2015-12/2018 were analysed. Multivariable Cox proportional hazard models and Youden index driven C-statistics were used to assess additive prognostic value of GLS, T1 and ECV mapping on the combined endpoint of cardiovascular death, cardiac transplantation, LVAD  insertion  or hospitalisation for heart failure in models incorporating NHYA class, EF and LGE status. Additionally. the value of GLS, T1, and ECV on predicting significant arrhythmic events (SAV) (ventricular arrhythmia (VA), resuscitated cardiac arrest (rCA) or sudden cardiac death (SCD)) was assessed.

Results; Patients (mean age 59, 66% male, 60% ≥NYHA II, mean EF 42%, mean GLS -12%, mean ECV 27%) were on good medical therapy (beta blocker 74%%, ACE 79%, MRA 38%, Entresto 5%, CRT 23%). Mean follow-up was 21 months; the combined endpoint occurred in 34 patients (5%). On univariate analysis NYHA class (HR 2.44 (1.67-3.57), p &lt; 0.001), ECV (HR 1.14 (1.05-1.22), p &lt; 0.001), GLS% (HR 1.14 (1.07-1.21) p &lt; 0.001,) T1 (HR 1.06 (1.005-1.1), p = 0.03), RVEF (HR 0.95 (0.93-0.98), p &lt; 0.001), LVEF (HR 0.92 (0.9-0.95), p &lt; 0.001) were all significantly associated with outcome. On multivariate analysis only EF and NYHA class was associated with outcome.

SAV occurred as the first manifestation of disease or during follow up in 27 patients (4%). At univariate analysis LGE, ECV, GLS, EF and NYHA class were all associated with SAV. However, on multivariable analysis only EF, LGE  and ECV (HR 1.11 (1.01-1.22), p = 0.03) but not GLS remained independently predictive in a model already incorporating EF, NYHA and LGE.

Conclusion

Optimally treated DCM populations have very low event rates. CMR based assessment of fibrosis status/burden with both LGE and ECV assessment has the potential to enhance patient selection for ICD therapy. Whilst GLS is increasingly recognised as a sensitive imaging biomarker of early disease detection it provides no additive value,  likely because of it’s high co-linearity with EF, in models already containing EF, NYHA class and LGE status.

Methylation of the hippo signalling effector YAP by SETD7 drives myocardial ischemic injury

Introduction

Myocardial ischemia/reperfusion (I/R) injury is one of the most deleterious cardiovascular conditions and a leading cause of mortality. The Hippo pathway effector YAP critically regulates cardiomyocyte proliferation and survival during myocardial I/R injury. However, the mechanisms regulating YAP activation in this setting remain poorly understood. Post-translational modifications of proteins, namely methylation, modulate pathways implicated in myocardial I/R injury. The methyltransferase SETD7 is emerging as a regulator of cell survival via methylation of histone and non-histone proteins. Whether SETD7 participates to myocardial I/R injury remains elusive.

Purpose

To investigate the role of SETD7 in regulating Hippo signaling during myocardial I/R injury.

Methods

Neonatal rat ventricular myocytes (NRVM) were exposed to normal glucose levels or glucose deprivation (GD) for 15 h, in the presence of the selective SETD7 inhibitor [(R)-PFI-2] or its inactive enantiomer [(S)-PFI-2]. Western blot and real time PCR were employed to investigate the effects of energy stress on SETD7 and the Hippo pathway, while apoptosis was assessed by Caspase-3 activity assay. YAP activity was assessed through chromatin immunoprecipitation assay (ChIP), its localization was examined by confocal microscopy while mono-methylation was assessed by immunoblotting. SETD7 knockout (SETD7−/−) mice and wild-type (WT) littermates (male, 8–12 weeks old) underwent 1 h of left anterior descending (LAD) coronary artery ligation followed by 24 h of reperfusion. Infarct size was assessed by TTC staining and shown as infarct size per ventricle surface (I/V). Cardiac function was investigated at 24h by conventional and Tissue Doppler Imaging (TDI) echocardiography.

Results

GD in NRVMs led to upregulation of SETD7 and physical interaction with the pro-survival transcriptional cofactor YAP, resulting in its direct mono-methylation. Furthermore SETD7-dependent methylation of YAP led to its cytosolic retention and subsequent reduction of YAP binding to the promoter of pro-survival genes. Of note, pharmacological inhibition of SETD7 by (R)-PFI-2 blunted YAP mono-methylation while restoring its nuclear retention. Mechanistically, SETD7 inhibition promoted YAP binding to catalase and superoxide dismutase (SOD) gene promoters, thus preventing GD-induced mitochondrial oxidative stress and apoptosis. In line with our in vitro findings, SETD7−/− mice showed decreased infarct size as compared to WT littermates and preserved cardiac systolic (ejection fraction, fractional shortening) and diastolic function, as assessed by both conventional and TDI echocardiography.

Conclusions

We show that SETD7-dependent methylation of YAP is required for its inactivation, thus leading to myocyte oxidative stress and apoptosis. Pharmacological modulation of SETD7 by (R)-PFI-2 may represent a new therapeutic approach to prevent myocardial ischemic damage through modulation of the Hippo pathway.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Swiss Heart Foundation

A comparison of in vivo viral targeting systems identifies adeno-associated virus serotype 9 (AAV9) as an effective vector for genetic manipulation of Leydig cells in adult mice

BACKGROUND

Despite the increasing popularity of deliverable transgenics, a robust and fully validated method for targeting Leydig cells, capable of delivering long-term transgene expression, is yet to be defined.

OBJECTIVES

We compared three viral vector systems in terms of their cell targeting specificity, longevity of gene expression and impact on targeted cell types when delivered to the interstitial compartment of the mouse testis.

MATERIALS & METHODS

We delivered lentiviral, adenoviral and adeno-associated (AAV) viral particles to the interstitial compartment of adult mouse testis. Immunolocalization and stereology were performed to characterize ability of vectors to target and deliver transgenes to Leydig cells.

RESULTS

Viral vectors utilized in this study were found to specifically target Leydig cells when delivered interstitially. Transgene expression in lentiviral-targeted Leydig cells was detected for 7 days post-injection before Leydig cells underwent apoptosis. Adenoviral-delivered transgene expression was detected for 10 days post-injection with no evidence of targeted cell apoptosis. We found serotype differences in AAV injected testis with AAV serotype 9 targeting a significant proportion of Leydig cells. Targeting efficiency increased to an average of 59.63% (and a maximum of 80%) of Leydig cells with the addition of neuraminidase during injection. In AAV injected testis sections, transgene expression was detectable for up to 50 days post-injection.

DISCUSSION & CONCLUSION

Lentivirus, Adenovirus and Adeno-Associated virus delivery to the testis resulted in key variances in targeting efficiency of Leydig cells and in longevity of transgene expression, but identified AAV9 + Neuraminidase as an efficient vector system for transgene delivery and long-term expression. Simple viral delivery procedures and the commercial availability of viral vectors suggests AAV9 + Neuraminidase will be of significant utility to researchers investigating the genetics underpinning Leydig cell function and holds promise to inform the development of novel therapeutics for the treatment of male reproductive disorders.

Machine learning-based FDG PET-CT radiomics for outcome prediction in larynx and hypopharynx squamous cell carcinoma

AIM

To determine whether machine learning-based radiomic feature analysis of baseline integrated 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET) computed tomography (CT) predicts disease progression in patients with locally advanced larynx and hypopharynx squamous cell carcinoma (SCC) receiving (chemo)radiotherapy.

MATERIALS AND METHODS

Patients with larynx and hypopharynx SCC treated with definitive (chemo)radiotherapy at a specialist cancer centre undergoing pre-treatment PET-CT between 2008 and 2017 were included. Tumour segmentation and radiomic analysis was performed using LIFEx software (University of Paris-Saclay, France). Data were assigned into training (80%) and validation (20%) cohorts adhering to TRIPOD guidelines. A random forest classifier was created for four predictive models using features determined by recursive feature elimination: (A) PET, (B) CT, (C) clinical, and (D) combined PET-CT parameters. Model performance was assessed using area under the curve (AUC) receiver operating characteristic (ROC) analysis.

RESULTS

Seventy-two patients (40 hypopharynx 32 larynx tumours) were included, mean age 61 (range 41-77) years, 50 (69%) were men. Forty-five (62.5%) had chemoradiotherapy, 27 (37.5%) had radiotherapy alone. Median follow-up 26 months (range 12-105 months). Twenty-seven (37.5%) patients progressed within 12 months. ROC AUC for models A, B, C, and D were 0.91, 0.94, 0.88, and 0.93 in training and 0.82, 0.72, 0.70, and 0.94 in validation cohorts. Parameters in model D were metabolic tumour volume (MTV), maximum CT value, minimum standardized uptake value (SUVmin), grey-level zone length matrix (GLZLM) small-zone low grey-level emphasis (SZLGE) and histogram kurtosis.

CONCLUSION

FDG PET-CT derived radiomic features are potential predictors of early disease progression in patients with locally advanced larynx and hypopharynx SCC.

Tumour growth rate of carcinoma of the colon and rectum: retrospective cohort study

BACKGROUND

The growth pattern of colorectal cancer is seldom investigated. This cohort study aimed to explore tumour growth rate in colorectal cancers managed non-surgically or deemed not resectable, and to determine its implication for prognosis.

METHODS

Consecutive patients with colonic or rectal adenocarcinoma were identified through the colorectal multidisciplinary team database at Leeds Teaching Hospitals NHS Trust over a 2-year interval. Patients who received no treatment (surgery, stenting, colonic defunctioning procedures, chemotherapy, radiotherapy) and who underwent CT twice more than 5 weeks apart were included. Multidetector CT/three-dimensional image analysis was performed independently by three experienced radiologists.

RESULTS

Of 804 patients reviewed, 43 colorectal cancers were included in the final analysis. Median age at first CT was 80 (73-85) years and the median interval between scans was 150 (i.q.r. 72-471) days. An increase in T category was demonstrated in 31 of 43 tumours, with a median doubling time of 211 (112-404) days. The median percentage increase in tumour volume was 34·1 (13·3-53·9) per cent per 62 days. The all-cause 3-year mortality rate was 81 per cent (35 of 43) with a median survival time of 1·1 (0·4-2·2) years after the initial diagnostic scan. In those obstructed, the relative risk of death from subsequent perforation was 1·26 (95 per cent c.i. 1·07 to 1·49; P = 0·005).

CONCLUSION

This study documented a median doubling time of 211 days, with a concerning suggestion of tumour progression, which has implications for the current management standard.

Local field potential activity dynamics in response to deep brain stimulation of the subthalamic nucleus in Parkinson's disease

Local field potentials (LFPs) may afford insight into the mechanisms of action of deep brain stimulation (DBS) and potential feedback signals for adaptive DBS. In Parkinson's disease (PD) DBS of the subthalamic nucleus (STN) suppresses spontaneous activity in the beta band and drives evoked resonant neural activity (ERNA). Here, we investigate how STN LFP activities change over time following the onset and offset of DBS. To this end we recorded LFPs from the STN in 14 PD patients during long (mean: 181.2 s) and short (14.2 s) blocks of continuous stimulation at 130 Hz. LFP activities were evaluated in the temporal and spectral domains. During long stimulation blocks, the frequency and amplitude of the ERNA decreased before reaching a steady state after ~70 s. Maximal ERNA amplitudes diminished over repeated stimulation blocks. Upon DBS cessation, the ERNA was revealed as an under-damped oscillation, and was more marked and lasted longer after short duration stimulation blocks. In contrast, activity in the beta band suppressed within 0.5 s of continuous DBS onset and drifted less over time. Spontaneous activity was also suppressed in the low gamma band, suggesting that the effects of high frequency stimulation on spontaneous oscillations may not be selective for pathological beta activity. High frequency oscillations were present in only six STN recordings before stimulation onset and their frequency was depressed by stimulation. The different dynamics of the ERNA and beta activity with stimulation imply different DBS mechanisms and may impact how these activities may be used in adaptive feedback.

Direct modifications of the cyclic peptide Polymyxin B leading to analogues with enhanced in vitro antibacterial activity

Synthetic modifications have been made directly to the cyclic peptide core of polymyxin B, enabling the further understanding of structure activity relationships of this antimicrobial peptide. Such modified polymyxins are also substrates for enzymic hydrolysis, enabling the synthesis of a variety of semi-synthetic analogues, resulting in compounds with increased in vitro antibacterial activity.

P790 Bi-ventricular dysfunction in patients after bone marrow transplant: the value of strain imaging

Background

Cardiovascular events are a significant cause of morbidity and mortality in cancer survivors, particularly occurring at 5-10 years after their cancer therapy.

Purpose

To assess the utility of strain imaging by 2-dimensional (2D) speckle tracking echocardiography in detecting bi-ventricular dysfunction, as compared to traditional measures, in patients post bone marrow transplantation (BMT) with previous anthracycline (AC) therapy for haematological conditions.

Methods

50 consecutive patients post BMT + AC, reviewed at a long-term survivor clinic, were compared to 50 age and gender matched controls. 48/50 patients received AC doses below the recommended cumulative lifetime thresholds set by the European Society of Medical Oncology. 2D left ventricular global longitudinal strain (LV GLS) and right ventricle free wall strain (RV FWS) were compared to conventional measures of bi-ventricular function.

Results

The mean LVEF (58 ± 6% vs 63 ± 6%) and RV fractional area change (FAC) (39 ± 5% vs 44 ± 5%), although reduced in the BMT + AC group vs controls, were within normal limits. LV GLS was reduced in BMT + AC patients as compared to controls (-17.8 ± 3.1% vs -20.5 ± 2.2%, p &lt; 0.01) while RV FWS was also reduced (-23.2 ± 4.0% vs -27.9 ± 2.7%, p &lt; 0.001). In BMT + AC patients with a preserved LVEF (LVEF &gt; 53%), 28% (11/40) had reduced GLS (GLS &lt; -17%) while 52% (24/46) of those with preserved FAC (FAC &gt; 35%) had reduced FWS (FWS &lt; -25%). Major adverse cardiac events (MACE) occurred in 9/50 patients in the BMT + AC group and none in the control group. 8/9 patients had normal biventricular function as assessed by traditional parameters (LVEF and RV FAC) but 5/9 patients had reduced LV GLS and/or RV FWS.

Conclusions

Subclinical bi-ventricular dysfunction is common in patients post BMT + AC therapy, and can be detected using strain analysis, despite preserved LV and RV systolic function using conventional measures. MACE occurred at a significantly higher rate in BMT patients exposed to AC. More than half of MACE events occurred in patients with reduced LV or RV strain, with preserved bi-ventricular function by traditional measures. LV GLS and RV FWS should be utilised for early identification of subclinical dysfunction in BMT patients.

P353 Structural, functional, and electromechanical alterations in patients with paroxysmal atrial fibrillation compared to healthy controls

Background and Methods

We sought to evaluate the clinical and echocardiographic differences between healthy controls and paroxysmal atrial fibrillation (AF) patients. Clinical and echocardiographic parameters (performed in sinus rhythm) in 46 paroxysmal AF patients were compared with a departmental database of 83 health controls.

Results

AF patients were older and had increased body size (Table 1). 39/46 (84%) of AF patients had hypertension and 23/46 (50%) had diabetes mellitus.

AF patients had increased left ventricular (LV) mass, and reduced diastolic function (lower e’ and increased E/e’ ratio) when compared to healthy controls. Left atrial (LA) volumes were significantly increased in the AF group. All strain parameters – reservoir, conduit, and contractile strain – were impaired in AF patients compared to controls. LA mechanical dispersion (MD) was significantly increased in AF patients. A ratio of indexed LA volume/LA reservoir strain was significantly higher in AF patients over controls.

The duration of AF had an inverse correlation with LA reservoir strain (Fig 1) (r=–0.78; p &lt; 0.001).

Conclusions

Compared to healthy controls, patients with paroxysmal AF have significant structural, functional and electromechanical alterations. LA strain is significantly impaired in paroxysmal AF and correlates with AF duration.

Table 1. Echocardiographic parameters Parameter Controls (mean ± SD) AF patients (mean ± SD) P value Age (years) 48 ± 18 58 ± 14 0.001 Body surface area (m2) 1.9 ± 0.2 2 ± 0.2 0.014 LV mass (g) 178 ± 48 223 ± 68 &lt;0.001 Average e’ velocity (cms-1) 10.3 ±2.7 8.1 ± 2.2 &lt;0.001 E/e’ 7.4 ± 1.9 9.3 ± 3.4 0.001 Indexed LA end systolic volume (ml/m2) 27.2 ± 7.1 39.0 ± 11.6 &lt;0.001 LA ejection fraction 55.2 ± 10.4 48.5 ± 14.0 0.007 LA functional index 43.7 ± 14.6 29.8 ± 14.3 &lt;0.001 LA reservoir strain (%) 34.3 ± 6.8 27.9± 8.1 &lt;0.001 LA conduit strain (%) 18.4 ± 6.2 13.5 ± 4.7 &lt;0.001 LA contractile strain (%) 15.9 ± 3.9 14.4 ± 5.5 0.007 LA mechanical dispersion (ms) 25.8 ± 9.6 30.9 ± 11.6 0.018 Indexed LA volume / Reservoir strain ratio 0.8 ± 0.3 1.6 ± 0.9 &lt;0.001 LV = left ventricular; LA = left atrium; SD = standard deviation

Abstract P353 Figure. Fig 1. AF duration vs. Reservoir strain

P970 Significant differences in atrial structural and functional parameters leading to differing mechanisms of atrial fibrillation in athletes compared to non-athletes

Methods

36 endurance athletes in sinus rhythm, with a previous history of AF (ATH-AF) were compared to age and gender matched endurance athletes with no prior history of AF (ATH), non athletes with paroxysmal AF (NONATH-AF) and age and gender matched healthy controls (CONTROL). A detailed transthoracic echocardiogram was performed with all groups in sinus rhythm, with detailed left atrial (LA) and left ventricular (LV) measurements, including strain analysis.

Results

All athletes had increased LA and LV size when compared with healthy controls (Table 1). Non athletes with paroxysmal AF had increased LA size when compared with controls. However, indexed LA/LV ratio was preserved in athletes and similar to healthy individuals, whilst AF patients had significantly increased LA/LV ratio. Athletes with AF had higher e’ velocity and lower E/e’, whereas e’ was reduced and E/e’ elevated in non-athlete AF patients.

Athletes had impaired LA reservoir and contractile strain, and reduced LV global longitudinal strain (GLS) compared with healthy controls.

Conclusions

Compared to healthy controls, athletes have reduced LA and LV strain, with preserved LV diastolic function and LA/LV ratio. In contrast, altered diastolic function with differential increase in LA volume was observed in AF patients. The increased risk of AF in athletes is likely mediated by different mechanistic processes other than an atrial myopathy consequent to diastolic dysfunction as observed in non-athletes with AF.

Table 1. LA and LV parameters Parameter ATH-AF ATH NONATH-AF CONTROL P value LVEDV indexed (ml/m2) 84 ± 12 79 ± 14 57 ± 10 51 ± 13 &lt;0.001 LVESV indexed (ml/m2) 35 ± 6 34 ± 7 25 ± 8 27 ± 33 0.02 LV ejection fraction (%) 58 ± 4 56 ± 4 56 ± 10 58 ± 8 0.586 LV global longitudinal strain (%) 19.2 ± 1.7 18.9 ± 2.1 21 ± 3.1 21.7 ± 2.9 &lt;0.001 e’ vel (cm/s) 10 ± 2 10 ± 3 8 ± 2 9 ± 2 0.007 E/e’ 5.7 ± 1.3 5.9 ± 1.8 9.1 ± 3.3 7.5 ± 1.5 &lt;0.001 LAV max indexed (ml/m2) 45 ± 11 43 ± 12 38 ± 11 27 ± 8 &lt;0.001 Indexed LAV/LVEDV ratio 0.5 ± 0.1 0.6 ± 0.2 0.7 ± 0.2 0.5 ± 0.1 &lt;0.001 LA reservoir strain (%) 27.2 ± 4.8 28.2 ± 3.7 27.9 ± 8.4 33.2 ± 7.0 &lt;0.001 LA conduit strain (%) 14.2 ± 4.5 14.4 ± 4.0 14.9 ± 5.5 16.6 ± 6.3 0.182 LA contractile strain (%) 13.0 ± 3.1 13.8 ± 3.6 13.0 ± 5.1 16.6 ± 3.1 &lt;0.001 LV = left ventricular, LAV = left atrial volume, LA = left atrial

P1504 Inter-vendor comparison of left atrial 2-dimensional strain using multilayer analysis

BACKGROUND

Left atrial strain (LAS) is increasingly being accepted as a marker of left atrial function. Different vendors utilise different techniques of measuring LAS in echocardiography.

AIMS

To determine the difference between multilayer endocardial and mid-myocardial measurements of LA strain on General Electric (GE) Echopac compared to the TOMTEC system which tracks endocardial strain.

METHODS

Peak reservoir left atrial strain (LAS) was measured on 50 healthy controls using the two different echocardiographic software packages. GE Echopac (v201) 2D-speckle tracking echocardiography technique (LV package) was used to measuremid-myocardial (GE-mid) and endocardial (GE-endo) LAS. This was compared to LAS measurement using TOMTEC (v4.6) which uses an endocardial tracking technique. LAS was measured in 4ch and 2ch views and average biplane strain measurement was obtained.

RESULTS

The mean of GE-mid LAS was 36.3 ± 6.3%, GE-endo LAS was higher with a mean of 44.1 ± 8.0%, while TOMTEC LAS was 42.1 ± 6.3 %. GE-mid and GE-endo LAS correlated well with TOMTEC LAS (r = 0.9, p &lt; 0.001 for both). On Bland-Altman Analysis, GE-mid LAS measurements were systematically lower than TOMTEC LAS (mean difference -5.77), whereas GE-endo LAS had no systematic bias (mean difference 1.99).

CONCLUSIONS

Mid-myocardial peak reservoir left atrial strain, which is routinely measured using GE Echopac software, systematically underestimates LAS as compared to TOMTEC LAS or GE endocardial LAS. This suggests that serial follow up of LAS measurements for patients should be performed on the same software.

P309 The use of echocardiographic parameters to predict clinical outcomes in AL-amyloidosis cardiomyopathy

Background

AL-amyloidosis has a rapid clinical progression, with cardiac involvement associated with a particularly poor prognosis. Cardiac amyloidosis is diagnosed by either invasive biopsy or conventional echocardiographic parameters such as increased wall thickness, in the absence of other causes. More recently, novel parameters including 2D longitudinal strain have demonstrated diagnostic utility in a range of infiltrative cardiomyopathies including cardiac amyloidosis.

Aim/Method: We sought to evaluate traditional and novel echocardiographic parameters in their ability to predict adverse outcomes in a cohort of AL-amyloid patients. 80 patients who had transthoracic echocardiograms at a single centre were included. Comprehensive echocardiographic assessment was performed, including left ventricular ejection fraction (LVEF), LV Global Longitudinal Strain (GLS), LV mass (indexed to BSA). The primary endpoint was a composite of of major adverse cardiac events (MACE) and all-cause mortality, that was assessed by interrogation of the medical records on a specified censor date.

Results

At a mean follow-up (time from echo to censor date) of 5.4 ± 2.6years, 38/80 (47.5%) of patients experienced the primary endpoint of MACE or death, of which 25/80 (31%) were deaths. LVEF (59 ± 5.6%vs56 ± 6.4%, p = 0.04), GLS (17.4 ± 3.9%vs14.8 ± 4.9%, p = 0.01) basal longitudinal strain (12.3 ± 3.2%vs9.6 ± 3.9%, p = 0.002), indexed LV mass (107 ± 36g/m2vs130 ± 34g/m2, p = 0.06) and E/E’ (13.7 ± 4.9vs20.6 ± 9.6, p &lt; 0.001) were all significantly different between patients who experienced the primary endpoint and those that didn’t. The strongest predictors of outcome were E/E’ (AUC 0.74), LV mass (AUC 0.73) and the ratio GLS:LV mass (AUC 0.73). An E/E’ of 15 had a sensitivity of 71% and specificity of 69%, while an indexed LV mass of 108 had a sensitivity and specificity of 74% and 67% respectively. GLS to LV mass as a cutoff of 0.16 had a sensitivity and specificity of 70% and 69% respectively.

Conclusion

In a cohort of 80 patients with AL-amyloid cardiomyopathy, almost half (47.5%) reached the primary composite endpoint. Diastolic dysfunction as expressed as E/E’, and LV mass were the most powerful predictors of outcome, while global longitudinal strain and LV basal strain were also reduced, and showed superiority over LV ejection fraction in predicting prognosis.

P1543 The assessment of regional myocardial strain in classifying amyloid cardiomyopathy

Background

An infiltrative cardiomyopathy is a common manifestation of AL-amyloidosis, with cardiac involvement associated with a poor prognosis. Wild-type transthyretin amyloidosis (wt-TTR), is a distinct clinical entity occurring predominantly in men &gt; 65 yrs, that has gained interest recently due to novel treatment options. Regional strain analysis has been shown to discriminate both forms of cardiac amyloidosis from other causes of concentric left ventricular hypertrophy, with a characteristic pattern of ‘apical sparing’. Due to the significant difference in both the course of the disease and treatment options between groups, a non-invasive echocardiographic method of determining subtype would be valuable.

Aim/Method: We sought to compare traditional and novel echocardiographic parameters in a cohort of AL ( n = 80) and wild type (wt-TTR) amyloid ( n = 32) patients. All amyloid patients underwent comprehensive transthoracic echocardiography, including both conventional parameters and LV longitudinal strain. Further novel parameters were computed including the ratio of global longitudinal strain (GLS) to LV ejection fraction (LVEF), as well as GLS to indexed LV mass.

Results

wt-TTR patients had significantly greater LV mass (176 ± 59g/m2vs118 ± 37g/m2, p &lt; 0.001), and worse diastolic dysfunction as expressed as E/E’ (21.5 ± 11vs17 ± 8, p = 0.04). LVEF was significantly lower in wt-TTR patients however remained in the normal range in both groups (53 ± 6%vs57 ± 6%, p = 0.001), whilst GLS was significantly reduced compared to AL-amyloid patients (11.5 ± 3.4%vs16.2 ± 4.6%, p &lt; 0.001). LVEF:GLS was significantly higher in wt-TTR patients (4.93 ± 1.4vs3.87 ± 1.3, p = 0.001) reflecting a more profound reduction in strain with a relatively preserved ejection fraction. Similarly, the ratio of GLS to LV mass was significantly lower in wt-TTR amyloidosis (0.078 ± 0.05vs0.155 ± 0.07, p &lt; 0.001), reflecting a more significant reduction in strain for a given wall thickness in wt-TTR patients. GLS:LV mass was the strongest discriminator between subtypes (AUC 0.82), with a cutoff of 0.09 giving a sensitivity and specificity of 71% and 80% respectively, for detecting wt-TTR.

Conclusion

In this cohort, patients with wt-TTR had significantly greater increase in LV wall thickness and diastolic dysfunction, which may in part reflect their increased age (77vs62). However, GLS was also significantly reduced compared to AL-amyloid, even when accounting for LV ejection fraction and LV mass, suggesting these composite parameters may have value in determining the subtype of cardiac amyloidosis.

Applicability of the ACE-III and RBANS Cognitive Tests for the Detection of Alcohol-Related Brain Damage

Background and Aims

Recent investigations have highlighted the value of neuropsychological testing for the assessment and screening of Alcohol-Related Brain Damage (ARBD). The aim of the present study was to evaluate the suitability of the Addenbrooke’s Cognitive Examination (ACE-III) and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) for this purpose.

Methods

Comparing 28 participants with ARBD (11 with Korsakoff’s Syndrome and 17 with the umbrella “ARBD” diagnosis) and 30 alcohol-dependent participants without ARBD (ALs) we calculated Area Under the Curve (AUC) statistics, sensitivity and specificity values, base-rate adjusted predictive values, and likelihood ratios for both tests.

Results

High levels of screening accuracy were found for the total scores of both the ACE-III (AUC = 0.823, 95% CIs [0.714, 0.932], SE = 0.056; optimal cut-off ≤86: sensitivity = 82%, specificity = 73%) and RBANS (AUC = 0.846, 95% CIs [0.746, 0.947], SE = 0.052; optimal cut-off ≤83: sensitivity = 89%, specificity = 67%) at multiple cut-off points. Removing participants with a history of polysubstance from the samples (10 ALs and 1 ARBD) improved the diagnostic capabilities of the RBANS substantially (AUC = 0.915, 95% CIs [0.831, 0.999], SE = 0.043; optimal cut-off ≤85: sensitivity = 98%, specificity = 80%), while only minor improvements to the ACE-III’s accuracy were observed (AUC = 0.854, 95% CIs [0.744, 0.963], SE = 0.056; optimal cut-off ≤88: sensitivity = 85%, specificity = 75%).

Conclusion

Overall, both the ACE-III and RBANS are suitable tools for ARBD screening within an alcohol-dependent population, though the RBANS is the superior of the two. Clinicians using these tools for ARBD screening should be cautious of false-positive outcomes and should therefore combine them with other assessment methods (e.g., neuroimaging, clinical observations) and more detailed neuropsychological testing before reaching diagnostic decisions.

Photostimulated Luminescence Detection of Irradiated Herbs, Spices, and Seasonings: International Interlaboratory Trial

An interlaboratory trial was conducted to validate photostimulated luminescence (PSL) methods for herbs, spices, and seasonings. Forty products (11 herbs, 17 spices, and 12 seasonings) were purchased from a local commercial source, and randomly selected samples were irradiated with 10 kGy. Four blended products were prepared at Scottish Universities Research and Reactor Centre, mixing varying proportions of irradiated material with the untreated product. Precharacterization against a predefined threshold identified low sensitivity products (black and white peppers) and products with high natural signals (thyme, sage, parsley, and mixed herbs), both of which might be susceptible to misclassification. Precharacterization also revealed whether calibration was likely to resolve overlap between classification categories. Eight sets of screening data and 5 sets of calibrated data were returned by participants. Of the 840 samples sent, 1593 screening measurements and 788 calibrated measurements were received from 662 samples. In screening mode, participants reached definitive conclusions in 87% of cases, 99% of which were correct. Of the remaining 13%, calibration to identify low-sensitivity resolved 60% of cases. Overall, 94% of samples were correctly identified by either screening alone, or screening plus calibration; 6% remained unclassified and therefore required further investigation by thermoluminescence. The results confirm the validity of the PSL method for herbs, spices, seasonings, and blends, and emphasize the need for calibration to identify low-sensitivity samples. This method has now been adopted by the European Committee for Standardization (CEN) and the Codex Alimentarius Commission.

Photostimulated Luminescence Detection of Irradiated Shellfish: International Interlaboratory Trial

An interlaboratory trial was conducted to validate photostimulated luminescence (PSL) detection of irradiated shellfish. Five species of shellfish (Nephrops norvegicus, mussels, black tiger prawns, brown shrimps, and king scallops) were presented blind as nonirradiated and irradiated to 0.5 and 2.5 kGy. Precharacterization analysis of each product and treatment was performed on both whole (including shell) and intestinal samples. The results for whole samples (including shell) confirmed that the method was able to distinguish between nonirradiated and irradiated samples, regardless of dose. Intestinal data have identified that the method is dependent on the quantity and sensitivity of grits present within the intestinal tract, which can be assessed using calibration by normalization to 1 kGy. Five laboratories returned both initial screening and calibrated data and sample classification. All laboratories correctly identified all irradiated products using the screening criteria. There were no false positives. The results confirm the validity of the PSL method for shellfish, which has been adopted as a European standard method and by the Codex Alimentarius Commission. Calibration is required where only intestinal material is available. For whole samples with shell, screening alone is sufficient.

P736Histone marks induced by the methyltransferase SETD7 modulate angiogenic response in diabetes

Introduction

Despite advances in revascularization strategies, type 2 diabetic (T2D) patients with peripheral artery disease (PAD) continue to have a high risk of limb amputation. Hence, strategies that promote vascularization can be considered as a novel therapeutic option in T2D patients with PAD. Epigenetic modifications of histones and DNA have emerged as key modulators of gene expression. Mono-methylation of histone 3 at lysine 4 (H3K4m1) – a specific epigenetic signature induced by the methyltransferase SETD7 – favours a chromatin conformation enabling the transcription of genes involved in inflammation and oxidative stress.

Purpose

To investigate whether SETD7 modulates angiogenesis in experimental diabetes.

Methods

Human aortic endothelial cells (HAECs) were cultured in growth factor-free medium and exposed either to normal glucose (NG, 5 mM) or high glucose (HG, 25 mM) for 48 hours. SETD7 protein and H3K4me1 levels were investigated by Western blot and chromatin immunoprecipitation (ChIP). Knockdown of SETD7 was achieved by small interfering RNA (siRNA). Pharmacological blockade of SETD7 was performed by using the highly selective inhibitor (R)-PFI-2, while its inactive enantiomer, (S)-PFI-2, was used as a control. Scratch and tube formation assays were performed to investigate the impact of SETD7 on angiogenic properties of HAECs. RNA sequencing (RNA-seq) and Ingenuity Pathway Analysis (IPA) were employed to unveil putative genes regulated by SETD7 in HG-treated HAECs. SETD7 expression was also investigated in muscular specimens isolated from type 2 diabetic (db/db) mice and non-diabetic mice undergoing hindlimb ischemia for 21 days.

Results

HG exposure in HAECs led to a time-dependent increase of both SETD7 gene and protein expression, as compared to NG. SETD7 upregulation in HG-treated HAECs was associated with an increase of H3K4me1 levels as well as with impaired endothelial cell migration and tube formation. Of interest, both gene silencing and pharmacological blockade of SETD7 rescued hyperglycemia-induced impairment of angiogenic properties in HAECs. RNA-seq in HG-treated HAECs with and without SETD7 depletion unveiled an array of differentially expressed genes, which were mainly involved in blood vessel growth and angiogenic response, as assessed by IPA analysis. Among dysregulated genes, ChIP assays showed that SETD7-dependent chromatin changes enabled the transcription of Semaphorin 3G (SEMA-3G), a negative regulator of endothelial cell migration. Indeed, gene silencing of SETD7 blunted SEMA-3G expression in HAECs exposed to HG. Consistent with our in vitro observations, SETD7 was upregulated in adductor muscle specimens from db/db mice undergoing hindlimb ischemia as compared to non-diabetic animals.

Conclusions

Pharmacological blockade of SETD7 by (R)-PFI-2 may represent a potential therapeutic approach to boost post-ischemic vascularization in T2D patients with PAD.

Design of Next Generation Polymyxins with Lower Toxicity: The Discovery of SPR206

Polymyxins are an important class of antibiotics for the treatment of bacterial infections due to multidrug resistant Gram-negative pathogens. However, their clinical utility is limited by nephrotoxicity. Here, we report a series of promising next generation polymyxin nonapeptides identified on the basis of our understanding of the relationship of structure with activity, cytotoxicity, and kidney compartment accumulation. We demonstrate that nonapeptides with an amine-containing N-terminal moiety of specific regio- and stereochemistry possess superior in vitro activity, together with lower cytotoxicity compared to polymyxin B. We further demonstrate that compounds with a β-branched aminobutyrate N-terminus with an aryl substituent offer a promising combination of low cytotoxicity and kidney exposure, leading to low toxicity in the mouse. From this series, SPR206 has been selected as a development candidate.

P5378The methyltransferase SETD7 promotes myocardial ischemic injury by activating Hippo signalling

Introduction

Despite significant advances in coronary revascularization, acute myocardial infarction remains the leading cause of heart failure and death worldwide. The Hippo pathway is a master regulator of cell survival during myocardial ischemia. Upon cellular stress, activation of Hippo signaling leads to cytosolic retention and degradation of the pro-survival transcription factor YAP. Post-translational modifications, namely methylation, critically affect protein functionality in conditions of cellular stress. The SET domain-containing lysine methyltransferase 7 (SETD7) - which induces a specific mono-methylation of both histone and non-histone proteins - has recently emerged as key player in the pathogenesis of vascular disease. However, the role of SETD7 in the heart is largely unknown.

Purpose

The present study investigates whether SETD7 regulates the Hippo pathway during myocardial ischemia.

Methods

Neonatal rat ventricular myocytes (NRVM) were exposed to normal glucose levels or glucose deprivation (GD) for 15 h, in the presence of the selective SETD7 inhibitor [(R)-PFI-2] or its inactive enantiomer [(S)-PFI-2]. Western blot and real time PCR were employed to investigate the effects of energy stress on SETD7 and the Hippo pathway, while apoptosis was assessed by Caspase-3 activity assay. YAP localization was examined by confocal microscopy while its mono-methylation was assessed by immunoblotting. SETD7 knockout (SETD7−/−) mice and wild-type (WT) littermates (male, 8–12 weeks old) underwent 1 h of left anterior descending (LAD) coronary artery ligation followed by 24 h of reperfusion. Infarct size was assessed by TTC staining and shown as infarct size per ventricle surface (I/V). Cardiac function was investigated at 24h by conventional and Tissue Doppler Imaging echocardiography (Vevo 3100, Visualsonics).

Results

GD for 15h in NRVMs led to both YAP phosphorylation and mono-methylation, and subsequent cytosolic retention, as assessed by confocal microscopy. Reduced nuclear content of YAP was confirmed by downregulation of YAP-dependent pro-survival genes, namely Ctgf and Fgf2. GD-induced YAP inactivation was associated with an increase in SETD7 expression. Interestingly, pharmacological inhibition of SETD7 by (R)-PFI-2 blunted YAP mono-methylation, thus restoring nuclear retention of YAP and transcription of pro-survival genes in GD-treated NRVMs. Moreover, (R)-PFI-2 prevented NRVMs apoptosis. In line with our in vitro findings, SETD7−/− mice showed decreased infarct size as compared to WT littermates (I/V: 16.27%±2 vs. 20.54%±3, p<0.005, respectively). Consistently, cardiac function, as assessed by ejection fraction (EF: 46%±2 vs. 38%±5, p<0.001), fractional shortening (FS: 22%±1 vs. 18%±3, p<0.001) as well as by TDI, was preserved in mice lacking SETD7 as compared to WT animals.

Conclusions

Pharmacological modulation of SETD7 by (R)-PFI-2 may represent a novel therapeutic approach to prevent myocardial ischemic damage.