Expanding the clinical spectrum of biglycan-related Meester-Loeys syndrome

Pathogenic loss-of-function variants in BGN, an X-linked gene encoding biglycan, are associated with Meester-Loeys syndrome (MRLS), a thoracic aortic aneurysm/dissection syndrome. Since the initial publication of five probands in 2017, we have considerably expanded our MRLS cohort to a total of 18 probands (16 males and 2 females). Segregation analyses identified 36 additional BGN variant-harboring family members (9 males and 27 females). The identified BGN variants were shown to lead to loss-of-function by cDNA and Western Blot analyses of skin fibroblasts or were strongly predicted to lead to loss-of-function based on the nature of the variant. No (likely) pathogenic missense variants without additional (predicted) splice effects were identified. Interestingly, a male proband with a deletion spanning the coding sequence of BGN and the 5' untranslated region of the downstream gene (ATP2B3) presented with a more severe skeletal phenotype. This may possibly be explained by expressional activation of the downstream ATPase ATP2B3 (normally repressed in skin fibroblasts) driven by the remnant BGN promotor. This study highlights that aneurysms and dissections in MRLS extend beyond the thoracic aorta, affecting the entire arterial tree, and cardiovascular symptoms may coincide with non-specific connective tissue features. Furthermore, the clinical presentation is more severe and penetrant in males compared to females. Extensive analysis at RNA, cDNA, and/or protein level is recommended to prove a loss-of-function effect before determining the pathogenicity of identified BGN missense and non-canonical splice variants. In conclusion, distinct mechanisms may underlie the wide phenotypic spectrum of MRLS patients carrying loss-of-function variants in BGN.

Dynamic Exosome Analysis to Predict Response to the Combination of SABR and Immunotherapy in Oligoprogressive Disease

PURPOSE/OBJECTIVE(S)

Up to 80% of metastatic patients face resistance to immune checkpoint inhibitors (ICI). Combined SABR and ICI (I-SABR) can unleash antitumor immune cascades to overcome resistance and improve response with minimal toxicity. This synergy is particularly interesting in the oligoprogressive setting to extend the clinical benefit (CB) of ICI. However, there are no current biomarkers for patient selection. We hypothesize that differential expression of exosomal RNA in liquid biopsy may predict response to I-SABR.

MATERIALS/METHODS

Ongoing prospective multicenter study in two cohorts. Cohort A consists of metastatic patients in oligoprogression to ICI (1-5 extracranial sites) but maintaining the same ICI due to CB and who receive concomitant SABR (35 Gy in 5 fractions, fx) to oligoprogressive sites. Cohort B is a comparative group of oligometastatic patients receiving only SABR in ablative doses. Blood samples are extracted before SABR (T1), after the first (T2) and last (T3) fx, two months post-SABR (T4) and at further progression (TP). Response is evaluated by iRECIST and defined by the objective response rate (ORR) in all lesions (in and out-of-field)- complete and partial responses. For exosome analysis, we perform RNA isolation and small RNA sequencing from plasma. We use Cutadapt, Bowtie and featureCounts to quantify the number of reads of miRNA, small nuclear RNA (snRNA) and small nucleolar RNA (snoRNA). Pairwise differences in expression in responders and non-responders are examined by DESeq2 differential expression analysis. Differentially expressed transcripts are consulted in Ingenuity Pathway Analysis (IPA).

RESULTS

Of 22 patients recruited, we present preliminary results of the first 10 (8 from cohort A and 2 from B) that had undergone re-evaluation after SABR. Most frequent cancer types were lung (60%) and renal cell (20%). Seventy percent were polymetastatic (>5 lesions) and 90% had a single progressing site. Pembrolizumab (40%) and Nivolumab (30%) were the most frequent ICI. Most lesions for SABR were lung (45%). With a median follow-up of 7.1 months (95% CI, 3.7-10.6) ORR at two months was 60% (6 partial responses, 1 stable disease and 3 progressions). Median progression-free survival was 10.3 months (95% CI, 3.7-not reached) and median overall survival was not reached. Seven patients in cohort A were available for small RNA analysis. We identified 3 miRNA, 24 snRNA and 9 snoRNA that were significantly differentially expressed at T1. Hsa-miR-493, marker of tumor progression, was upregulated in non-responders. RN7SK inhibits LAS1L (a known inductor of metastasis in lung cancer) and was upregulated in responders. SNORD71, which is inhibited by ILF3 (promotor of progression), was also upregulated in responders.

CONCLUSION

I-SABR is an effective approach for extending CB of ICI in oligoprogressive patients. Exosomal RNA expression analysis in liquid biopsy is a novel and non-invasive technique that may predict response to this combination and aid in patient selection.

Pre-defined gene co-expression modules in rheumatoid arthritis transition towards molecular health following anti-TNF therapy

BACKGROUND

No reliable biomarkers to predict response to TNF inhibitors (TNFi) in RA patients currently exist. The aims of this study were to replicate changes in gene co-expression modules that were previously reported in response to TNFi therapy in RA; to test if changes in module expression are specific to TNFi therapy; and to determine whether module expression transitions towards a disease-free state in responding patients.

METHOD

Published transcriptomic data from the whole blood of disease-free controls (n = 10) and RA patients, treated with the TNFi adalimumab (n = 70) or methotrexate (n = 85), were studied. Treatment response was assessed using the EULAR response criteria following 3 or 6 months of treatment. Change in transcript expression between pre- and post-treatment was recorded for previously defined modules. Linear mixed models tested whether modular expression after treatment transitioned towards a disease-free state.

RESULTS

For 25 of the 27 modules, change in expression between pre- and post-treatment in the adalimumab cohort replicated published findings. Of these 25 modules, six transitioned towards a disease-free state by 3 months (P < 0.05), irrespective of clinical response. One module (M3.2), related to inflammation and TNF biology, significantly correlated with response to adalimumab. Similar patterns of modular expression, with reduced magnitude, were observed in the methotrexate cohort.

CONCLUSION

This study provides independent validation of changes in module expression in response to therapy in RA. However, these effects are not specific to TNFi. Further studies are required to determine whether specific modules could assist molecular classification of therapeutic response.

Drivers of COVID-19 vaccine hesitancy among women of childbearing age in Victoria, Australia: A descriptive qualitative study

Objective

Women of childbearing age, including pregnant and breastfeeding women, report higher COVID-19 vaccine hesitancy, but reasons for this hesitancy are unknown. We explored factors influencing vaccine decision-making among women of childbearing age in Victoria, Australia to inform strategies to increase COVID-19 vaccine uptake.

Methods

Twenty-four women aged 18-40 years were interviewed July-October 2021. Interview data were analyzed thematically using an inductive, constructivist approach.

Results

Of 24 participants, 14 (57%) were vaccine-hesitant, of whom 10/14 pregnant or breastfeeding. Six key themes were identified: weighing up perceived risks for self and baby; availability of information; change and contradictions; vaccination above everything; practical issues – hurdles of inconvenience. Vaccine-hesitant women’s concerns included safety in pregnancy, breastfeeding and fertility effects. Some participants expressed a loss of trust in healthcare providers following vaccine mandates.

Conclusions

Public health campaigns and communication should be tailored to address specific concerns to increase COVID-19 vaccine uptake and prevent negative COVID-19 outcomes for women of childbearing age. Findings suggest that effective strategies to address hesitancy in this group may include providing robust short- and long-term safety data across fertility, birth outcomes and child development following COVID-19 vaccination. Other supportive strategies may include systemic changes like making childcare available at vaccination points (where practical), and using data linkage infrastructure to track post-vaccination outcomes.

In vitro susceptibility of canine corneal bacterial pathogens to three cross-linking protocols

OBJECTIVE

To assess in vitro antibacterial efficacy of three cross-linking (XL) protocols on bacteria associated with canine ulcerative keratitis.

METHODS

Three XL protocols: UVA 3 mW/cm² for 60 min, UVA 3 mW/cm² for 30 min, and UVA 30 mW/cm² for 3 min with and without application of riboflavin and a riboflavin-only protocol were performed in vitro on the four most common bacterial genera isolated from cases of canine ulcerative keratitis treated at Dick White Referrals, UK. Zones of bacterial growth inhibition (GIZ) associated with treatment were measured and compared.

RESULTS

The four most common isolates were Pseudomonas aeruginosa (PA) (48/140, 34.3%), Streptococcus spp. (32/140, 22.9%), Staphylococcus spp. (24/140, 17.1%) and Escherichia coli (EC) (11/140, 7.9%). PA, EC, Streptococcus canis (SC), and Staphylococcus pseudintermedius (SP), isolated from canine corneas, were selected for testing. EC and SC demonstrated growth inhibition following all UVA/riboflavin protocols. PA and SP only displayed growth inhibition following the 60 min UVA/riboflavin protocol. GIZ areas for 60 min UVA/riboflavin protocols were significantly greater than 30 and 3 min UVA/riboflavin protocols (p < .01) and there was no significant difference between 30 and 3 min UVA/riboflavin protocols. In respect to GIZ areas, EC was significantly more susceptible to XL than SP (p = <.01).

CONCLUSIONS

All UVA/riboflavin XL protocols caused growth inhibition of EC and SC in vitro. PA and SP did not show clear growth inhibition in vitro following exposure to XL protocol settings of UVA 3 mW/cm² for 30 min and UVA 30 mW/cm² for 3 min.

Comparison of corneal culture results obtained using the ESwab™ and Amies charcoal swab in canine and feline patients

OBJECTIVE

The objective of the study was to compare corneal culture results using the ESwab™ and Amies charcoal swab.

ANIMALS STUDIED

One hundred fourteen canine and fifteen feline eyes.

PROCEDURES

Retrospective analysis of Dick White Referrals bacterial and fungal corneal culture data was conducted. Results were included from canine and feline patients, which presented with suspected infectious keratitis that had samples taken using an Amies charcoal swab followed by an ESwab™ in the same eye. In respect to positive and negative cultures, a McNemar test was conducted comparing instances of disagreement between swab types, and the Kappa coefficient (κ) was calculated to assess the level of agreement between swab types.

RESULTS

The ESwab™ produced more positive corneal cultures (71/129 [55.0%]) than the Amies charcoal swab (41/129 [31.8%]). 2/129 eyes produced positive fungal cultures. Considering 37/129 eyes in which both swab types detected a positive corneal culture, the same bacterial species were cultured from each swab type in 34/37 (91.9%) eyes, and an additional bacterial species was cultured by the ESwab™ in 3/37 (8.1%) eyes. In 34/38 (89.5%), instances of disagreement between swab types, the ESwab™ showed a positive culture, and the Amies charcoal swab showed a negative culture from the same eye, and this difference was significant (p < 0.0001). There was a moderate level of agreement between results from both swab types (κ = 0.432).

CONCLUSIONS

ESwab™ sampling alone may be superior to Amies charcoal swabs for detecting presence of bacteria in suspected infectious keratitis in cats and dogs.

P187 Pre-defined Gene Co-expression Modules in Rheumatoid Arthritis Transition towards Molecular Health following Tumour Necrosis Factor Inhibitor Therapy

Background/Aims

Tumour necrosis factor inhibitors (TNFi) have advanced the clinical management of rheumatoid arthritis (RA); however, only 30-40% of patients who receive initial treatment with a TNFi experience a beneficial response. The discovery of biomarkers of TNFi response would facilitate improved response rates and more objective monitoring of inflammation. Gene transcript levels measured in the blood of RA patients represent an attractive source of biomarkers. For example, a study by Oswald et al demonstrated reproducible changes in gene expression modules in RA patients treated effectively with a TNFi. Such gene modules were previously defined by Chaussabel et al following the assessment of gene co-expression patterns, transcript clustering patterns and functional associations amongst transcripts from several inflammatory diseases.

We aim to replicate the changes in modular gene co-expression reported to occur in response to TNFi therapy in RA in a UK cohort described by Oswald et al; to test if changes in modular expression are specific to TNFi therapy by analysing change in gene co-expression in response to methotrexate (MTX); and to determine if module expression transitions towards a disease-free state in responding patients.

Methods

Published whole blood transcriptomic data from disease-free controls (n = 10) and RA patients treated with either the TNFi adalimumab (n = 70) or MTX (n = 85) were studied. Transcriptomic data were available at pre-treatment and at 3-months (TNFi) and 4-weeks (MTX) post-treatment. Response to treatment was assessed using the EULAR response criteria following 3/6-months on-drug. For each of the 27 modules, the fraction of probes that significantly (p &lt; 0.05) changed in expression between time-points was recorded. Linear mixed models were used to test if module expression transitioned towards a disease-free state following treatment.

Results

In the TNFi cohort, 25 of the 27 modules significantly changed in expression between pre- and post-treatment, replicating published findings by Oswald et al. Six of these 27 modules transitioned towards a disease-free state by 3-months. Transition in module expression was irrespective of treatment response in 5 of the 6 modules, however one module (module 3.2) appeared to be dependent on good response to adalimumab. This module was linked to pathways of inflammation and TNF signalling. Similar patterns of modular expression changes were observed in the MTX cohort, but with reduced significance compared to TNFi treated patients.

Conclusion

This study provides independent replication of changes in modular gene expression in TNFi treated RA patients. Gene expression changes were observed regardless of treatment response and were not specific to TNFi therapy. These results suggest that some factors of biological response are not detected by clinical classifiers of treatment response. Further research is now needed to test the utility of gene modules for prediction of clinical response, or for objective monitoring of molecular pathways that are responsive to treatment.

Disclosure

M.A. Sutcliffe: None. N. Nair: None. J. Oliver: None. A. Morgan: None. J. Isaacs: None. G. Wilson: None. S. Verstappen: None. S. Viatte: None. K. Hyrich: None. A. Morris: None. A. Barton: None. D. Plant: None.

Use of Pulmonary Arterial Hypertension Therapies in Patients with a Fontan Circulation: Current Practice Across the United Kingdom

Background

The Fontan circulation is a successful operative strategy for abolishing cyanosis and chronic volume overload in patients with congenital heart disease with single ventricle physiology. “Fontan failure” is a major cause of poor quality of life and mortality in these patients. We assessed the number and clinical characteristics of adult patients with Fontan physiology receiving pulmonary arterial hypertension (PAH) therapies across specialist centers in the United Kingdom.

Methods and Results

We identified all adult patients with a Fontan‐type circulation under active follow‐up in 10 specialist congenital heart disease centers in England and Scotland between 2009 and 2019. Patients taking PAH therapies were matched to untreated patients. A survey of experts was also performed. Of 1538 patients with Fontan followed in specialist centers, only 76 (4.9%) received PAH therapies during follow‐up. The vast majority (90.8%) were treated with a phosphodiesterase‐5 inhibitor. In 33% of patients, PAH therapies were started after surgery or during hospital admission. In the matched cohort, treated patients were more likely to be significantly limited, have ascites, have a history of protein‐losing enteropathy, or receive loop diuretics (P<0.0001 for all), also reflecting survey responses indicating that failing Fontan is an important treatment target. After a median of 12 months (11–15 months), functional class was more likely to improve in the treated group (P=0.01), with no other changes in clinical parameters or safety issues.

Conclusions

PAH therapies are used in adult patients with Fontan circulation followed in specialist centers, targeting individuals with advanced disease or complications. Follow‐up suggests stabilization of the clinical status after 12 months of therapy.

Perfluorooctanoic acid induces liver and serum dyslipidemia in humanized PPARα mice fed an American diet

Per- and polyfluoroalkyl substances (PFAS) are pervasive in the environment resulting in nearly universal detection in people. Human serum PFAS concentrations are strongly associated with increased serum low-density lipoprotein cholesterol (LDL-C), and growing evidence suggests an association with serum triacylglycerides (TG). Here, we tested the hypothesis that perfluorooctanoic acid (PFOA) dysregulates liver and serum triacylglycerides in human peroxisome proliferator activated receptor α (hPPARα)-expressing mice fed an American diet. Mice were exposed to PFOA (3.5 mg/L) in drinking water for 6 weeks resulting in a serum concentration of 48 ± 9 μg/ml. In male and female hPPARα mice, PFOA increased total liver TG and TG substituted with saturated and monounsaturated fatty acids. Lack of expression of PPARα alone also increased total liver TG, and PFOA treatment had little effect on liver TG in PPARα null mice. In hPPARα mice, PFOA neither significantly increased nor decreased serum TG; however, there was a modest increase in TG associated with very low-density cholesterol particles in both sexes. Intriguingly, in female PPARα null mice, PFOA significantly increased serum TG, with a similar trend in males. PFOA also modified fatty acid and TG homeostasis-related gene expression in liver, in a hPPARα-dependent manner, but not in adipose. The results of our study and others reveal the importance of context (serum concentration and genotype) in determining the effect of PFOA on lipid homeostasis.

POS0357 MiRNAs CORRELATE WITH IMPROVEMENT IN DISEASE ACTIVITY IN PATIENTS WITH RHEUMATOID ARTHRITIS ON TUMOUR NECROSIS FACTOR INHIBITORS

Background:

Tumour necrosis factor inhibitors (TNFi) although effective in the treatment of rheumatoid arthritis (RA), show a variable response rate. Therefore, there is a need to identify treatment response predictors to inform therapy selection in order to practise precision medicine. MicroRNAs (miRNAs) are endogenous, single-stranded, non-coding RNAs that can alter gene expression by regulating messenger RNA translation. There is evidence for miRNA involvement in RA pathogenesis and they may serve as a useful biomarker of treatment response.

Objectives:

To identify miRNAs associated with response to TNFi in RA.

Methods:

Biologic naïve patients were selected from the Biologics in Rheumatoid Arthritis Genetics and Genomics Study Syndicate (BRAGGSS), a prospective multi-center UK study investigating treatment response biomarkers to TNFi with a primary outcome measure of change in DAS28 scores. Patients were stratified into European League Against Rheumatism (EULAR) good or non-responders based on their 3 or 6-month DAS28-CRP score.

Pre-treatment and 3-month post-treatment serum samples were substrates for miRNA profiling, which was conducted by FIRALIS using the HTG EdgeSeq miRNA whole transcriptome V2 targeted sequencing assay. Linear modelling using R package limma compared miRNA expression at (i) pre-treatment and at three-months, in EULAR good-responders and non-responders (ii) longitudinal change in expression from pre-treatment to three-months in EULAR good and non-responders.

A literature search was conducted to identify miRNAs associated with RA as a diagnostic and/or treatment response predictor. Data on these miRNAs were extracted from the miRNAs identified in the serum samples. A correction for multiple testing was applied to statistical tests.

Results:

A total of 54 patients were analysed; of these, 35 (65%) were female, median disease duration [inter-quartile range] was 6 years [2 – 14] (n=51), and 44/51 (86%) patients were on a concomitant disease modifying anti-rheumatic drug. Of the 54 patients, 39 (72%) were classified as EULAR good-responders and 15 (28%) as non-responders. 1880 miRNAs were detected in the serum samples. 64 miRNAs were identified to be associated with RA from the literature, of which, 26 were identified in the serum samples tested.

No difference in pre-treatment or three-month miRNA levels was seen comparing EULAR good-responders and non-responders (FDR p<0.05). There was a significant differential expression of four miRNAs at 3-months in good-responders compared with pre-treatment levels; miR-125a-3p (downregulated, p-value 0.002), miR-149-3p (upregulated, p-value 0.004), miR-766-3p (downregulated, p-value 0.008), miR-146b-5p (upregulated, p-value 0.006). No significant differences were observed between 3-months and baseline in non-responders.

Conclusion:

Although no pre-treatment miRNAs were associated with TNFi response, changes in the levels of four miRNAs were detected at 3-months compared to baseline in EULAR good-responders. Future work involves validation of these samples in a larger patient cohort and analysing miRNA levels at 6 and 12 months. Replication and validation of these results in larger studies are required to analyse the role of miRNAs in stratifying EULAR good-responders from non-responders at three-months, and as treatment response predictors to TNFi in RA.

Acknowledgements:

Joint last-author: Dr. Darren Plant

Disclosure of Interests:

Trixy David: None declared, Nisha Nair: None declared, James Oliver: None declared, Eric Schordan: None declared, Hüseyin Firat: None declared, Kimme Hyrich Consultant of: consultancy/honoraria from AbbVie, Grant/research support from: Pfizer, UCB, BMS, Ann Morgan: None declared, Anthony G Wilson: None declared, John D Isaacs Speakers bureau: consultancy/speaker fees from AbbVie, Gilead, Roche, UCB, Consultant of: consultancy/speaker fees from AbbVie, Gilead, Roche, UCB, Grant/research support from: Pfizer, Darren Plant: None declared, Anne Barton: None declared

Transcriptome-wide study of TNF-inhibitor therapy in rheumatoid arthritis reveals early signature of successful treatment

BACKGROUND

Despite the success of TNF-inhibitor therapy in rheumatoid arthritis treatment, up to 40% of patients fail to respond adequately. This study aimed to identify transcriptome-based biomarkers of adalimumab response in rheumatoid arthritis (RA) to aid timely switching in non-responder patients and provide a better mechanistic understanding of the pathways involved in response/non-response.

METHODS

The Affymetrix Human Transcriptome Array 2.0 (HTA) was used to measure the transcriptome in whole blood at pre-treatment and at 3 months in EULAR good- and non-responders to adalimumab therapy. Differential expression of transcripts was analysed at the transcript level using multiple linear regression. Differentially expressed genes were validated in independent samples using OpenArray™ RT-qPCR.

RESULTS

In total, 813 transcripts were differentially expressed between pre-treatment and 3 months in adalimumab good-responders. No significant differential expression was observed between good- and non-responders at either time-point and no significant changes were observed in non-responders between time-points. OpenArray™ RT-qPCR was performed for 104 differentially expressed transcripts in good-responders, selected based on magnitude of effect or p value or based on prior association with RA or the immune system, validating differential expression for 17 transcripts.

CONCLUSIONS

An early transcriptome signature of DAS28 response to adalimumab has been identified and replicated in independent datasets. Whilst treat-to-target approaches encourage early switching in non-responsive patients, registry evidence suggests that this does not always occur. The results herein could guide the development of a blood test to distinguish responders from non-responders at 3 months and support clinical decisions to switch non-responsive patients to an alternative therapy.

A narrative-informed evaluation of tree of life for parents of children with physical health conditions

BACKGROUND

Parents of children with chronic health conditions can face many challenges. The Tree of Life narrative therapy group intervention aims to connect parents with their skills and resources before collectively exploring the 'storms' (challenges) they face. A narrative-informed evaluation aimed to story the parents' experiences of attending the group.

METHODS

Seven parents attended a Tree of Life group intervention and then participated in a narrative-informed group interview to generate stories regarding their experience of the group. The interview was recorded with consent and later transcribed.

RESULTS

A thematic analysis was undertaken and highlighted that the group offered parents a 'safe place to stand' to talk about difficulties; a different perspective on their situation; connection with the skills of other parents; new ideas to introduce more independence to their child; and togetherness within the 'storms' (challenges).

CONCLUSIONS

The narrative-informed evaluation offered opportunities to further thicken parents' preferred identity stories whilst also contributing to the evidence base of narrative-informed group interventions for parents.

Transition for patients with congenital heart disease in the UK: need for a universal model with adequate training and support

Background

Adolescence is a vulnerable period for patients with congenital heart disease (CHD). Transition is a process that guides these patients through adolescence and ensures a smooth transfer to adult services, in order improve adherence to medical care and reduce loss to follow-up. While the importance of a formal Transition process is widely recognised and a requirement for specialist services in the UK, the optimal structure and delivery of Transition remains a matter of debate.

Aims

To examine the different models of Transition currently in place in specialist CHD centres around the UK.

Methods

A survey of Adult CHD centres in the UK was performed. A focus was placed on the structure of the Transition service, relevant training and areas of perceived improvement.

Results

There were 10 responses to our survey covering 10 specialist CHD centres. All respondents were consultant adult CHD specialists, looking after patients from the age of 16 [14–17] years. All centres have a specialised Transition service, which runs from the age 13 [11–15] to 18 [16–25] years (duration of transition 5 [2–13] years). The majority of centres (80%) report providing transition care “well before” transfer to adult care, whereas 20% provide transition care at or immediately before transfer (i.e. first adult CHD appointment). Transition is delivered by physicians and clinical specialist nurses in approximately equal numbers in 9 (90%) centres and exclusively by clinical nurse specialists in 1 (10%) centre. A median of 2 [1–5] visits are planned for each patient, with 7 (70%) centres seeing patients at least twice during transition. The majority, but not all centres (70%) provide a health passport during transition. A significant number of centres felt they werer not receiving sufficient support in the following domains: financial (50%), training (30%), clinical space (30%), referrals from paediatrics (50%). All respondents felt that their Transition service had room for improvement. Other areas of improvement highlighted included reduction in loss to follow-up, difficulties in providing a Transition service to patients followed in peripheral hospitals, the need for more support from paediatric services in referring all appropriate patients, and dedicated administrative support. The vast majority of respondents (9, 90%) felt equipped with the appropriate skills to care for transition patients. However, few (2, 20%) had completed formal training in more than one area related to adolescent health and transition.

Conclusions

While all CHD centres have a Transition service, Transition models and delivery differs significantly. There is urgent need for research in this area to develop a unified model, greater financial support and relevant training to optimise care.

Figure 1. Participating UK centres

Funding Acknowledgement

Type of funding source: None

Multicentre study on pulmonary arterial hypertension therapies in fontan patients: underutilised or of limited use?

Introduction

The Fontan circulation is successful in abolishing cyanosis and chronic volume overload in congenital heart disease (CHD) patients with single ventricle physiology. “Fontan failure” is a major cause of poor quality of life and mortality in these patients. Recently, pulmonary arterial hypertension (PAH) therapies have been used in Fontan patients with variable success, even though patients included in these studies are generally at the best end of the spectrum.

Aim

To assess contemporary patterns of PAH therapy in Fontan patients in large specialist CHD centres.

Methods

We identified all adult patients with a Fontan-type circulation under active follow-up in 8 specialist CHD centres between 2009 and 2019. Patients on PAH therapies were matched by age and gender to untreated patients (1:1 or 1:2). Baseline data were collated immediately prior to initiation of therapy (treated group) or from a synchronous routine clinical assessment (untreated group).

Results

During the study period, 70 Fontan patients were started on PAH therapy (6.5% of those under follow-up). The majority 63 (90.0%) were started on monotherapy with a phosphodiesterase-5 (PDE5) inhibitor, 6 (8.6%) patients were started on an endothelin receptor antagonist (ERA) and 1 (1.4%) received early sequential therapy with a PDE5 inhibitor and ERA. Prostacyclin analogues were not used, and no patients received triple therapy. Overall, 51 (72.9%) patients started therapy electively (49% in outpatient clinic, 51% as day case admission), while 18 (25.7%) were treated following urgent hospital admission with fluid overload +/− acute kidney injury. The remainder (2,2.9%) started therapy following cardiac surgery. Adverse events during treatment were rare. Patients starting PAH therapy were matched to 112 untreated patients (table 1). Patients were well matched between groups for age (p=0.52) and sex (p=0.27). Treated patients were more likely to be significantly impaired than matched patients (56.7% vs. 8.6% in NYHA class III/IV, p&lt;0.0001) and were more likely to have ascites (16.2% vs. 0.9%, p=0.0002). Treated patients were also more likely to have a lower albumin level (43 [14–56] vs. 45 [29–54], p=0.01) or to be on a loop diuretic e.g. furosemide (p&lt;0.0001), at a higher daily dose (p&lt;0.0001) than matched patients. Only a quarter of patients on therapies had no high-risk features (24.2%), 80% of whom were from a single centre.

Conclusion

A small minority of Fontan patients followed in specialist centres receive PAH therapies. PAH therapy was reserved in most centres for patients with more advanced disease, targeting predominantly those with a “failing Fontan” in an individualised approach, in line with the recent adult CHD American Heart Association (AHA) guidelines. Further studied are needed to establish the role of PAH therapies in Fontan patients, provided that adult patients with advanced disease who are at increased risk of adverse outcome are included.

Figure 1

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Dr Constantine received an educational grant from Actelion Pharmaceuticals, a Janssen company of Johnson & Johnson, which helped to pay for travel for data collection.

Perfluorooctanoic acid activates multiple nuclear receptor pathways and skews expression of genes regulating cholesterol homeostasis in liver of humanized PPARα mice fed an American diet

Humans are exposed to per- and polyfluoroalkyl substances (PFAS) in their drinking water, food, air, dust, and by direct use of consumer products. Increased concentrations of serum total cholesterol and low density lipoprotein cholesterol are among the endpoints best supported by epidemiology. The objectives of this study were to generate a new model for examining PFAS-induced dyslipidemia and to conduct molecular studies to better define mechanism(s) of action. We tested the hypothesis that perfluorooctanoic acid (PFOA) exposure at a human-relevant level dysregulates expression of genes controlling cholesterol homeostasis in livers of mice expressing human PPARα (hPPARα). Female and male hPPARα and PPARα null mice were fed a diet based on the "What we eat in America" analysis and exposed to PFOA in drinking water (8 μM) for 6 weeks. This resulted in a serum PFOA concentration of 48 μg/ml. PFOA increased liver mass, which was associated with histologically-evident lipid accumulation. Pooled analyses of serum lipoprotein cholesterol suggest that PFOA increased serum cholesterol, particularly in male mice. PFOA induced PPARα and constitutive androstane receptor target gene expression in liver. Expression of genes in four pathways regulating cholesterol homeostasis were also measured. PFOA decreased expression of Hmgcr in a PPARα-dependent manner. PFOA decreased expression of Ldlr and Cyp7a1 in a PPARα-independent manner. Apob expression was not changed. Sex differences were evident. This novel study design (hPPARα mice, American diet, long term exposure) generated new insight on the effects of PFOA on cholesterol regulation in the liver and the role of hPPARα.

Implantable cardioverter-defibrillator therapy to reduce sudden cardiac death in adults with congenital heart disease: A registry study

INTRODUCTION

The adult congenital heart disease (ACHD) population is rapidly expanding. However, a significant proportion of these patients suffer sudden cardiac death. Recommending implantable cardioverter-defibrillator (ICD) insertion requires balancing the need for appropriate therapy in malignant arrhythmia against the consequences of inappropriate therapy and procedural complications. Here we present long-term follow-up data for ICD insertion in patients with ACHD from a large Level 1 congenital cardiac center.

METHODS AND RESULTS

All patients with ACHD undergoing ICD insertion over an 18-year period were identified. Data were extracted for baseline characteristics including demographics, initial diagnosis, ventricular function, relevant medication, and indication for ICD insertion. Details regarding device insertion were gathered along with follow-up data including appropriate and inappropriate therapy and complications. A total of 136 ICDs were implanted during this period: 79 for primary and 57 for secondary prevention. The most common congenital cardiac conditions in both groups were tetralogy of Fallot and transposition of the great arteries. Twenty-two individuals in the primary prevention group received appropriate antitachycardia pacing (ATP), 14 underwent appropriate cardioversion, 17 received inappropriate ATP, and 15 received inappropriate cardioversion. In the secondary prevention group, 18 individuals received appropriate ATP, 8 underwent appropriate cardioversion, 8 received inappropriate ATP, and 7 were inappropriately cardioverted. Our data demonstrate low complication rates, particularly with leads without advisories.

CONCLUSION

ICD insertion in the ACHD population involves a careful balance of the risks and benefits. Our data show a significant proportion of patients receiving appropriate therapy indicating that ICDs were inserted appropriately.

The Development of Virtual Reality as a Tool to Investigate Eating Behavior

Objectives

The objective of this study was to a) determine the feasibility of eating in virtual reality (VR) environment while wearing a head mounted display (HMD) and b) determine the effect of eating in a virtual restaurant on food intake, sensory evaluation of the test food and masticatory parameters.

Methods

Fifteen adults were asked to report to the laboratory on two occasions, separated by at least one week, at their usual lunchtime. On reporting to the laboratory, surface electrodes were attached to the left and right masseter muscles to measure masticatory activity and a wristband placed on the non-dominant wrist to collect physiological data. The participant sat quietly for 5 minutes before a VR (HMD) was placed on their head. The HMD displayed either a virtual restaurant (pizzeria) or a blank scene (consisting of a white background and a table). The participant's hand movements were captured using an infrared camera mounted on the HMD so when the participant moved their hands this was represented by computer generated model hands in the VR scene. The test foods (pizza bites) were represented in VR using a 3D model of pizza bites. The test foods were arranged so that when the participant touched the test food model in the VR scene they touched the test food in real life allowing them to locate and pick up the test food. The participant was instructed to eat the test food until they felt comfortably full.  When the participant finished eating the equipment was removed and they completed questionnaires regarding their feelings of presence and experiences in the VR environment and their ratings of the test food attributes.

Results

Participants were able to successfully locate and eat the pizza rolls while in the VR environment. The participants feeling of presence was higher in the restaurant scene compared to the blank scene (P &lt; 0.05). Heart rate and skin temperature were higher in the restaurant scene (P &lt; 0.05). Differences in masticatory parameters were found with participants using fewer masticatory cycles before swallowing in the restaurant scene (P &lt; 0.05). There were no differences between scenes regarding the sensory evaluation of the test foods. There was no difference in food intake between the treatments.

Conclusions

Eating in VR is feasible and may provide a new method to understand eating behavior in different contexts.

Funding Sources

None.

Partial anomalous pulmonary venous drainage in patients presenting with suspected pulmonary hypertension: A series of 90 patients from the ASPIRE registry

Background and objective

There are limited data regarding patients with PAPVD with suspected and diagnosed PH.

Methods

Patients with PAPVD presenting to a large PH referral centre during 2007–2017 were identified from the ASPIRE registry.

Results

Ninety patients with PAPVD were identified; this was newly diagnosed at our unit in 71 patients (78%), despite 69% of these having previously undergone CT. Sixty‐seven percent had a single right superior and 23% a single left superior anomalous vein. Patients with an SV‐ASD had a significantly larger RV area, pulmonary artery and L‐R shunt and a higher % predicted DL_CO (all P < 0.05). Sixty‐five patients were diagnosed with PH (defined as mPAP ≥ 25 mm Hg), which was post‐capillary in 24 (37%). No additional causes of PH were identified in 28 patients; 17 of these (26% of those patients with PH) had a PVR > 3 WU. Seven of these patients had isolated PAPVD, five of whom (8% of those patients with PH) had anomalous drainage of a single pulmonary vein.

Conclusion

Undiagnosed PAPVD with or without ASD may be present in patients with suspected PH; cross‐sectional imaging should therefore be specifically assessed whenever this diagnosis is considered. Radiological and physiological markers of L‐R shunt are higher in patients with an associated SV‐ASD. Although many patients with PAPVD and PH may have other potential causes of PH, a proportion of patients diagnosed with PAH have isolated PAPVD in the absence of other causative conditions.

PAPVD was frequently missed in patients presenting with suspected PH. L‐R shunt was higher in patients with associated ASD. Although patients may have other potential causes of PH, some patients with PAH have isolated PAPVD without other causative conditions.

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Initial Results from Mobile Low-Dose Computerized Tomographic Lung Cancer Screening Unit: Improved Outcomes for Underserved Populations

Introduction

The National Lung Screening Trial (NLST) demonstrated that screening high‐risk patients with low‐dose computed tomography (CT) of the chest reduces lung cancer mortality compared with screening with chest x‐ray. Uninsured and Medicaid patients usually lack access to this hospital‐based screening test because of geographic and socioeconomic factors. We hypothesized that a mobile screening unit would improve access and confer the benefits demonstrated by the NLST to this underserved group, which is most at risk of lung cancer deaths.

Patients and Methods

We created a mobile unit by building a Samsung BodyTom portable 32‐slice low‐dose CT scanner into a 35‐foot coach; it delivers high‐quality images for both soft tissue and bone and includes a waiting area and high‐speed wireless internet connection for fast image transfer. The unit was extensively tested to show robustness and stability of mobile equipment. This project was designed to screen uninsured and underinsured patients, otherwise with eligibility criteria identical to that of the National Lung Screening Trial, with the only difference being exclusion of patients eligible for Medicare (which provides financial coverage for CT‐based lung cancer screening).

Results

We screened 550 patients (20% black, 3% Hispanic, 70% rural) with a male‐to‐female ratio of 1.1:1, median age 61 years (range, 55–64), and found 12 lung cancers at initial screen (2.2%), including 6 at stage I–II (58% of total lung cancers early stage) and 38 Lung‐RADS 4 (highly suspicious) lesions that are being followed closely. Incidental findings included nonlung cancers and coronary artery disease.

Discussion

In this initial pilot study, using the first mobile low‐dose whole body CT screening unit in the U.S., the initial cancer detection rate is comparable to that reported in the NLST, despite excluding patients over the age of 64 years who have Medicare coverage, but with marked improvement of screening rates specifically in underserved sociodemographic, racial, and ethnic groups and with better outcomes than conventionally found in the underserved and at lower cost per case.

Implications for Practice

This study shows clearly that a mobile low‐dose CT scanning unit allows effective lung cancer screening for underserved populations, such as impoverished African Americans, Hispanics, Native Americans, or isolated rural groups, and has a pick‐up rate of 1% for early stage disease. If confirmed in a planned randomized trial, this will be policy changing, as these groups usually present with advanced disease; this approach will produce better survival data at lower cost per case.

The BodyTom CT is the first mobile screening unit in the U.S., designed to improve access to lung cancer screening for underserved patient groups. This article reports results of the initial pilot study using this first‐of‐its‐kind mobile low‐dose whole body CT screening unit. Twelve cases of lung cancer were found in 550 smokers (including 6 early stage).

Maternal and fetal outcomes in pregnancies complicated by Marfan syndrome

OBJECTIVES

Information to guide counselling and management for pregnancy in women with Marfan syndrome (MFS) is limited. We therefore conducted a UK multicentre study.

METHODS

Retrospective observational study of women with MFS delivering between January 1998 and March 2018 in 12 UK centres reporting data on maternal and neonatal outcomes.

RESULTS

In total, there were 258 pregnancies in 151 women with MFS (19 women had prior aortic root replacements), including 226 pregnancies ≥24 weeks (two sets of twins), 20 miscarriages and 12 pregnancy terminations. Excluding miscarriages and terminations, there were 221 live births in 139 women. Only 50% of women received preconception counselling. There were no deaths, but five women experienced aortic dissection (1.9%; one type A and four type B-one had a type B dissection at 12 weeks and subsequent termination of pregnancy). Five women required cardiac surgery postpartum. No predictors for aortic dissection could be identified. The babies of the 131 (65.8%) women taking beta-blockers were on average 316 g lighter (p<0.001). Caesarean section rates were high (50%), particularly in women with dilated aortic roots. In 55 women, echocardiographic aortic imaging was available prepregnancy and postpregnancy; there was a small but significant average increase in AoR size of 0.84 mm (Median follow-up 2.3 months) CONCLUSION: There were no maternal deaths, and the aortic dissection rate was 1.9% (mainly type B). There with no identifiable factors associated with aortic dissection in our cohort. Preconception counselling rates were low and need improvement. Aortic size measurements increased marginally following pregnancy.

Effectiveness of mobile computerized tomographic (CT) lung scanning unit for early diagnosis of lung cancer in under-served populations

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Background: The National Lung Screening Trial (NLST) demonstrated that screening high-risk patients with low-dose CT (LDCT) of the chest reduces lung cancer mortality compared to screening with chest x-ray. Uninsured and Medicaid patients lack access to this hospital-based screening test due to geographic isolation/socio-economic factors. We hypothesized that a mobile screening unit would improve access and confer benefits demonstrated by the NLST to this under-served group, which is most at risk of lung cancer deaths. Methods: In collaboration with Samsung Inc, we inserted a BodyTom portable 32 slide low-dose CT scanner into a 35-foot coach, reinforced to avoid equipment damage, to function as a mobile lung scanning unit. The unit includes a waiting area, high speed wireless internet connection for rapid image transfer, and electronic tablets to deliver smoking cessation and health education programs and shared decision-making video aids. It has been certified as a lung cancer screening Center of Excellence by Lung Cancer Alliance. We employed the LUNG RADS approach to lesion classification, yielding high sensitivity and specificity in assessment. All films were reviewed by a central panel of oncologists, pulmonologists and radiologists. The protocol was approved by Chesapeake IRB, which oversees all LCI cancer trials. Interim analysis at this time was approved by the Oversight Committee. Results: We screened 470 under-served smokers between 4/2017-1/2019; M:F 1.1:1, mean age 61 years (range 55-64), with average pack year history of 45.7 (30-150) (25% African-American; 3% Hispanic; 65% rural; 100% uninsured, under-insured or Medicaid - NC Medicaid does not cover lung cancer screening). Patients over the age of 64 years were excluded as they are covered by Medicare for lung cancer screening. We found at initial screen 35 subjects with LUNG RADS 4 lesions, 49 subjects with LUNG RADS 3 lesions, 10 lung cancers (2.1%), including 4 at stage I-II. 4 non-lung cancers were identified and treated. Other incidental non-oncologic findings are the subject of another presentation. Conclusions: In this small sample using the first mobile low dose CT lung screening unit in the United States, the initial cancer detection rate is comparable to that reported in the NLST but with marked improvement of screening rates in underserved groups and with better anticipated outcomes at lower cost than if they had first presented with metastatic disease.

Maternal and fetal outcomes in pregnancies complicated by the inherited aortopathy Loeys-Dietz syndrome

OBJECTIVE

Pregnancies in women with Loeys-Dietz syndrome (LDS) are rare and are typically documented in case reports only. Early reports suggested high rates of maternal complications during pregnancy and the puerperium, including aortic dissection and uterine rupture, but information on fetal outcomes was very limited.

DESIGN

A retrospective cohort study.

SETTING

Eight specialist UK centres.

SAMPLE

Pregnant women with LDS.

METHODS

Data was collated on cardiac, obstetric, and neonatal outcomes.

MAIN OUTCOME MEASURES

Maternal and perinatal outcomes in pregnancies complicated by LDS.

RESULTS

Twenty pregnancies in 13 women with LDS were identified. There was one miscarriage, one termination of pregnancy, and 18 livebirths. In eight women the diagnosis was known prior to pregnancy but only one woman had preconception counselling. In four women the diagnosis was made during pregnancy through positive genotyping, and the other was diagnosed following delivery. Five women had a family history of aortic dissection. There were no aortic dissections in our cohort during pregnancy or postpartum. Obstetric complications were common, including postpartum haemorrhage (33%) and preterm delivery (50%). In all, 14/18 (78%) of deliveries were by elective caesarean section, at a median gestational age at delivery of 37 weeks. Over half the infants (56%) were admitted to the neonatal unit following delivery.

CONCLUSION

Women with LDS require multidisciplinary specialist management throughout pregnancy. Women should be referred for preconception counselling to make informed decisions around pregnancy risk and outcomes. Early elective preterm delivery needs to be balanced against a high infant admission rate to the neonatal unit.

TWEETABLE ABSTRACT

Pregnancy outcomes in women with Loeys-Dietz syndrome.

Two-scale topology optimization in computational material design: An integrated approach

In this work, a new strategy for solving multiscale topology optimization problems is presented. An alternate direction algorithm and a precomputed offline microstructure database (Computational Vademecum) are used to efficiently solve the problem. In addition, the influence of considering manufacturable constraints is examined. Then, the strategy is extended to solve the coupled problem of designing both the macroscopic and microscopic topologies. Full details of the algorithms and numerical examples to validate the methodology are provided.

eAppendicitis: Diagnostic uncertainty in appendicitis and the role of ehealth - does IT help?

The availability of medical information on the World Wide Web has grown as information technology has become more accessible. Patients seeking online information may be able to selfselect conditions having been adequately informed. This study evaluates the effect of eHealth information on those presenting to hospital with a suspected appendicitis and its effect on their management and clinical outcome. Patients who had performed online reading were more likely to go to theatre but were less likely to have a confirmed histological diagnosis of appendicitis.

Ischemic Optic Neuropathy in a Dog with Acute Bilateral Blindness and Primary Systemic Hypertension

A 6-year-old neutered female Jack Russell terrier was investigated for sudden onset prechiasmatic bilateral blindness, left circling, reduced proprioception in the right pelvic limb and right facial allodynia. Electroretinography was normal. Magnetic resonance imaging (MRI) examination revealed that the right optic nerve and the optic chiasm were hyperintense on diffusion weighted imaging and hypointense on apparent diffusion coefficient map consistent with ischemic optic neuropathy. A concurrent lacunar infarct was detected in the left rostral colliculus. Primary systemic hypertension was diagnosed based on blood pressure measurement and no detectable abnormalities on hematology, comprehensive serum biochemistry, urinalysis including protein/creatinine and cortisol/creatinine ratios and thoracic/abdominal imaging. Prednisolone for 10 days and amlodipine long-term were administered. Vision was not recovered after 7 months. Repeat MRI supported the diagnosis of ischemic lesions and revealed a recent striatocapsular infarct. Ischemic optic neuropathy is a well-recognized cause of blindness in humans and should be included as a differential diagnosis for acute prechiasmatic blindness in dogs.

Generation of segmental chips in metal cutting modeled with the PFEM

The Particle Finite Element Method, a lagrangian finite element method based on a continuous Delaunay re-triangulation of the domain, is used to study machining of Ti6Al4V. In this work the method is revised and applied to study the influence of the cutting speed on the cutting force and the chip formation process. A parametric methodology for the detection and treatment of the rigid tool contact is presented. The adaptive insertion and removal of particles are developed and employed in order to sidestep the difficulties associated with mesh distortion, shear localization as well as for resolving the fine-scale features of the solution. The performance of PFEM is studied with a set of different two-dimensional orthogonal cutting tests. It is shown that, despite its Lagrangian nature, the proposed combined finite element-particle method is well suited for large deformation metal cutting problems with continuous chip and serrated chip formation.