Acute results of a novel flexible tip radiofrequency catheter incorporating contact force sensing

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Abbott

Background

Catheter ablation is an established therapy for paroxysmal atrial fibrillation (PAF). The TactiFlex Ablation Catheter, Sensor-Enabled (TactiFlex SE) is a next-generation radiofrequency ablation catheter incorporating highly accurate fiber optics-based contact force sensing technology with a flexible, laser-cut tip. This is the first report of results from the TactiFlex IDE clinical study.

Purpose

To demonstrate that ablation with TactiFlex SE is safe and effective for the treatment of drug refractory, symptomatic PAF.

Methods

The TactiFlex IDE (NCT04356040) is a prospective, non-randomized, multi-center clinical study which enrolled 305 subjects worldwide in the main study. Enrollment in the main study began on June 26, 2020 and completed on June 8, 2021. Subjects underwent de novo Pulmonary Vein Isolation (PVI) and, if indicated, a Cavotricuspid Isthmus ablation (CTI line) for CTI-dependent atrial flutter.

Results

Acute procedural success was achieved in 98.6% (274/278) of the main study cohort who underwent an ablation procedure using the TactiFlex SE. First pass success, defined as isolation of all pulmonary veins (PVs) confirmed after a minimum 20 min waiting period was achieved in 89.6% (249/278) of subjects. This was a significant improvement versus the TactiSense IDE trial (TactiCath Ablation Catheter, Sensor-Enabled). Significant decreases were also seen in total procedure time (123 min [101.0, 163.5]), total PV ablation time (55.5 min [35.0, 81.0]), total fluoroscopy time (6.0 min [0.0, 13.0]) and irrigation fluid volume (450.0 mL [346.0, 636.0]) (values given as Median [Q1, Q3]), see FIGURE. All subjects have completed at least 90 days of follow-up. Only 2.6% (7/271) of subjects required a repeat procedure during the 90-day blanking period. The primary safety and effectiveness endpoints will be evaluated at 12-months. At 90 days, 4.3% (12/281) subjects had experienced a primary safety endpoint event.

Conclusions

The acute data from the TactiFlex IDE clinical study demonstrate safety and effectiveness of the TactiFlex SE catheter in the treatment of PAF. Ablation procedures performed using the next-generation TactiFlex SE catheter were shorter and had improved acute clinical effectiveness outcomes versus the TactiSense IDE. It is anticipated these results will also be reflected in the 12-month safety and effectiveness endpoints.

High-density mapping in catheter ablation for persistent atrial fibrillation

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Abbott Laboratories

Background

Pulmonary vein isolation (PVI) is an established treatment option for persistent atrial fibrillation (PersAF). Corresponding long-term success rates remain modest however, advancements in high-density (HD) mapping may better identify substrates. The HD grid-style mapping catheter (HD Grid) allows for simultaneous analysis of adjacent orthogonal bipolar signals that may assist in ablation strategy decisions to achieve favorable outcomes in treating PersAF.

Objective

This was a prospective, multi-center, observational study to quantify and characterize the use of a market-released HD mapping catheter in PersAF subjects.

Methods

HD Grid was used in PersAF subjects undergoing radiofrequency (RF) ablation across 25 sites to gather data regarding safety, mapping efficiency and quality, ablation strategies, and procedural outcomes.

Results

334 PersAF subjects (average age: 64.2 years; 76% male) were enrolled in this study. Types of maps generated included peak-to-peak voltage (78%; 322/413), local activation time (LAT) (11.4%; 47/413), and complex fractionated electrogram (CFE) mean (7.7%; 32/413). Median total mapping points collected and used were 8428.0 (IQR 4845.0-13366.0) and 2099.0 (IQR 1219.0-2947.0), respectively, in a median of 11.0 (IQR 7.3-16.0) minutes per map. Low voltage, scar/fibrosis, and CFE were searched for in 90.4% (302/334), 53.6% (179/334), and 15.9% (53/334) of subjects, respectively. A PVI approach was used in 93.1% of all ablation procedures and 34.1% (114/334) of subjects received PVI plus additional lesions. HD Grid identified signals of interest not identified by the ablation catheter in 80.4% (205/255) of subjects. The total procedure time was 134.3 ± 51.3 minutes with a fluoroscopy time of 14.5 ± 11.3 minutes and RF ablation time of 32.4 ± 29.6 minutes. Of the subjects in atrial fibrillation (AF) (59.6%; 199/334), AF was terminated in 80.4% (160/199). 87.4% (173/198) of subjects were free from recurrent atrial arrhythmias as detected by 48-hour Holter monitoring at 12 months. 13.8% (46/334) of subjects experienced any adverse event through 12 months including 1 death unrelated to the procedure and 1 event deemed related to HD Grid by the investigator.

Conclusion

This study demonstrated the use of the HD Grid mapping catheter to create detailed maps and to guide ablation strategies to treat PersAF while maintaining an adequate safety profile.

Patterns Testing for Tick-Borne Diseases and Implications for Surveillance in the Southeastern US

IMPORTANCE

Tick-borne diseases (TBD), including spotted fever group rickettsiosis (SFGR), ehrlichiosis, and, increasingly, Lyme disease, represent a substantial public health concern throughout much of the southeastern United States. Yet, there is uncertainty about the epidemiology of these diseases because of pitfalls in existing diagnostic test methods.

OBJECTIVE

To examine patterns of diagnostic testing and incidence of TBD in a large, academic health care system.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study included diagnostic test results for TBD at UNC Health, a large academic health care system with inpatient and outpatient facilities, from January 1, 2017, to November 30, 2020. Participants included all individuals seeking routine care at UNC Health facilities who had testing for SFGR, ehrlichiosis, or Lyme disease performed during the study period.

MAIN OUTCOMES AND MEASURES

Rates of test positivity, testing completeness, and incidence of TBD.

RESULTS

During the 4-year study period, 11 367 individuals (6633 [58.4%] female; 10 793 [95%] non-Hispanic individuals and 8850 [77.9%] White individuals; median [IQR] age, 53 [37-66] years) were tested for TBD. Among the 20 528 diagnostic tests performed, 47 laboratory-confirmed, incident cases of SFGR, 27 cases of ehrlichiosis, and 76 cases of Lyme were confirmed, representing incidence rates of 4.7%, 7.1%, and 0.7%, respectively. However, 3984 of SFGR tests (79.3%) and 3606 of Ehrlichia tests (74.3%) lacked a paired convalescent sample. Of 20 528 tests, there were 11 977 tests (58.3%) for Lyme disease from 10 208 individuals, 5448 tests (26.5%) for SFGR from 4520 individuals, and 3103 tests (15.1%) for ehrlichiosis from 2507 individuals. Most striking, testing for ehrlichiosis was performed in only 55% of patients in whom SFGR was ordered, suggesting that ehrlichiosis remains underrecognized. An estimated 187 incident cases of SFGR and 309 of ehrlichiosis were potentially unidentified because of incomplete testing.

CONCLUSIONS AND RELEVANCE

In this cross-sectional study, most of the patients suspected of having TBD did not have testing performed in accordance with established guidelines, which substantially limits understanding of TBD epidemiology. Furthermore, the data revealed a large discrepancy between the local burden of disease and the testing performed. These findings underscore the need to pursue more robust, active surveillance strategies to estimate the burden of TBD and distribution of causative pathogens.

Social determinants of health influence disease activity and functional disability in Polyarticular Juvenile Idiopathic Arthritis

BACKGROUND

Social determinants of health (SDH) greatly influence outcomes during the first year of treatment in rheumatoid arthritis, a disease similar to polyarticular juvenile idiopathic arthritis (pJIA). We investigated the correlation of community poverty level and other SDH with the persistence of moderate to severe disease activity and functional disability over the first year of treatment in pJIA patients enrolled in the Childhood Arthritis and Rheumatology Research Alliance Registry.

METHODS

In this cohort study, unadjusted and adjusted generalized linear mixed effects models analyzed the effect of community poverty and other SDH on disease activity, using the clinical Juvenile Arthritis Disease Activity Score-10, and disability, using the Child Health Assessment Questionnaire, measured at baseline, 6, and 12 months.

RESULTS

One thousand six hundred eighty-four patients were identified. High community poverty (≥20% living below the federal poverty level) was associated with increased odds of functional disability (OR 1.82, 95% CI 1.28-2.60) but was not statistically significant after adjustment (aOR 1.23, 95% CI 0.81-1.86) and was not associated with increased disease activity. Non-white race/ethnicity was associated with higher disease activity (aOR 2.48, 95% CI: 1.41-4.36). Lower self-reported household income was associated with higher disease activity and persistent functional disability. Public insurance (aOR 1.56, 95% CI 1.06-2.29) and low family education (aOR 1.89, 95% CI 1.14-3.12) was associated with persistent functional disability.

CONCLUSION

High community poverty level was associated with persistent functional disability in unadjusted analysis but not with persistent moderate to high disease activity. Race/ethnicity and other SDH were associated with persistent disease activity and functional disability.

A139 EQUITY IN ACCESS TO COLORECTAL CANCER SCREENING IN NOVA SCOTIA

Background

Population-based colorectal cancer (CRC) screening programs aim to minimize inequities in participation through universal access, however, there remain disparities associated with low education, socio-economic status, and population centre. In the United States racialized groups have lower screening participation, and Black and Indigenous adults have higher CRC mortality. There is no Canadian data on racialized group participation in CRC screening because racial and ethnic data is not routinely collected. The Nova Scotia Colon Cancer Prevention Program (NSCCPP) mails fecal immunochemical tests (FIT) biennially to all residents aged 50–74 and allows for optional self-identified race and ethnicity.

Aims

To determine whether participation rates in the NSCCPP differ on the basis of race/ethnicity, age, sex, or population centre. In this preliminary analysis we report screening participation on the basis of race/ethnicity.

Methods

A retrospective cohort study was performed using the NSCCPP database to identify screen-eligible adults who returned a FIT to the program (i.e. participated) from 2011 to 2021. Racialized groups were identified based on self-identification form results allowing for multiple category selections. Race/Ethnicity was categorized as White, Black/African Canadian, Indigenous, Asian, Middle Eastern. The 2016 Canadian census was used to estimate the screen-eligible population (age 50–74) and race/ethnicity group population sizes. Unique participants were identified as individuals who returned one or more FITs in the study period. Unique participants were compared to the screen-eligible population to estimate participation over the 10-year study period.

Results

508,533 FITs were returned over 10 years by 208,702 unique participants. The number of annual FITs returned ranged from 14,066 in 2011 to 65,746 in 2019. Participants were 56% female, 44% male, with a mean age 62.8 (± 7.0). FIT status was 89% negative, 7% positive, and 4% indeterminate. 96% (n=490,398) of participants provided self-identification data. Table 1 provides the screen-eligible population, unique participants, and FIT participation over the 10-year study period all characterized by race/ethnicity. Over 10 years, 59% of the eligible population participated in CRC screening by returning at least one FIT.

Conclusions

CRC screening participation by race/ethnicity in Canada is unknown. This analysis of the NSCCPP suggests that participation by racialized individuals including Black/African Canadian, Asian, and Indigenous, are lower relative to White individuals. Further analyses will explore race/ethnicity and gender in terms of temporal and geographic trends.

Table 1.

Funding Agencies

None

Barriers and facilitators to targeted anxiety prevention programmes in families at risk: a qualitative interview study

Anxiety disorders are the most common psychiatric disorder in children and young people. They can be prevented in those at risk, but families do not always take up opportunities to participate in prevention programmes. This qualitative study aimed to understand what families with children who were at prospective risk of anxiety disorders perceived to be the barriers to access to targeted anxiety prevention programmes, and to explore what would help facilitate access. We used Information Power to determine our sample size, and individually interviewed seven young people (14-17 years) who had anxiety disorders and their mothers, each of whom had pre-natal anxiety disorders. We transcribed all interviews and thematically analyzed them to identify perceived barriers and facilitators to targeted anxiety prevention programmes. Perceived potential barriers to access included possible negative consequences of anxiety prevention, difficulties in identifying anxiety as a problem and concerns about how professions would respond to raising concerns about anxiety. Possible facilitators included promoting awareness of anxiety prevention programmes and involvement of schools in promotion and delivery of prevention. Our findings illustrate that implementation of targeted anxiety prevention could be improved through (i) the provision of tools for parents to recognize anxiety in their children as a problem, (ii) promotion of awareness, as well as delivery, of anxiety prevention via schools and (iii) the involvement of parents and possibly adolescents in the intervention programme, but not younger children.

Determining the role of natural SARS-CoV-2 infection in the death of domestic pets: 10 cases (2020-2021)

OBJECTIVE

To establish a pathoepidemiological model to evaluate the role of SARS-CoV-2 infection in the first 10 companion animals that died while infected with SARS-CoV-2 in the US.

ANIMALS

10 cats and dogs that tested positive for SARS-CoV-2 and died or were euthanized in the US between March 2020 and January 2021.

PROCEDURES

A standardized algorithm was developed to direct case investigations, determine the necessity of certain diagnostic procedures, and evaluate the role, if any, that SARS-CoV-2 infection played in the animals' course of disease and death. Using clinical and diagnostic information collected by state animal health officials, state public health veterinarians, and other state and local partners, this algorithm was applied to each animal case.

RESULTS

SARS-CoV-2 was an incidental finding in 8 animals, was suspected to have contributed to the severity of clinical signs leading to euthanasia in 1 dog, and was the primary reason for death for 1 cat.

CONCLUSIONS AND CLINICAL RELEVANCE

This report provides the global community with a standardized process for directing case investigations, determining the necessity of certain diagnostic procedures, and determining the clinical significance of SARS-CoV-2 infections in animals with fatal outcomes and provides evidence that SARS-CoV-2 can, in rare circumstances, cause or contribute to death in pets.

Evidence-Based Determination of Cut-Off Points for Increased Cardiac-Surgery Mortality Risk With EuroSCORE II and STS: The Best-Performing Risk Scoring Models in a Single-Centre Australian Population

OBJECTIVES

Risk scoring models (RSMs) are commonly used for estimation of postoperative-mortality risk in patients undergoing cardiac surgery, but their prediction accuracy may vary in different populations and clinical situations. The prognostic accuracies of some RSMs have not yet been fully evaluated in the Australian population. In this retrospective observational study, our aims were to assess the performance of four contemporary RSMs, to identify the best RSMs for prediction of postoperative-mortality in the single-centre cohort, and to determine a statistical threshold for classification of patients with increased or "higher" mortality risk.

METHODS

The study population included patients who underwent cardiac surgery at Liverpool Hospital between January 2013 and December 2014. Demographic information was collected, and mortality risks were estimated with the ES2 (EuroSCORE II), STS (Society of Thoracic Surgeons Score), AS (AusSCORE total) and ASMR (AusSCORE multi-risk) RSMs. (Additive EuroSCORE) (AES) and LES (logistic EuroSCORE) were included for historical interest. Discrimination, the ability to stratify patients between mortality and no mortality outcomes, and calibration, the comparison of risk score estimated and observed outcome in the population, were evaluated for each RSM, to determine their predictive accuracy in the study population. Discrimination was assessed by the AUC (area under the receiver operating characteristic curve), and acceptable calibration by the p-value greater than 0.05 for the Hosmer-Lemeshow (H-L) test. The best AUCs in contempory models were compared using the DeLong test. For ES2 and STS risk scores, cut-off points, or thresholds, for patients at increased risk of mortality were derived using Youden's J-statistics, calculated from sensitivity and specificity of models in predicting mortality.

RESULTS

From a total study population of 898 patients, 738 had scores for all six RSMs. The three EuroSCORE risk models and Youden's J-statistics analysis included the total population. Of the models in contemporary use, ES2 had higher discrimination (AUC=0.850) in this population than ASMR (AUC=0.767, p=0.024) and AS (AUC=0.739) and non-significantly higher discrimination than STS (AUC=0.806, p=0.19). All contemporary models had acceptable calibration but the older LES (H-L p=0.024) did not. Estimated mortality was closest to observed mortality with the ES2 model. Both AES and LES over predicted mortality. The RSM with the highest discrimination in isolated coronary artery bypass graft surgery (CAGs) (AUC=0.847), isolated valves (AUC=0.830), and females (AUC=0.784) was the ES2 model. STS discrimination was highest in CAGs plus valve procedures (AUC 0.891), and males (STS AUC=0.891). Cut-off points for risk scores to define increased risk populations were 3.0% for ES2 and 1.7% for STS. Similar proportions of patients in each RSM (ES2-26% to STS-32%) were defined as higher risk by the model threshold score depending on type of procedure.

CONCLUSION

Among RSMs in contemporary use, ES2 and STS showed the best discrimination and acceptable calibration. Caution is recommended in specific subgroups. Increased mortality risk score cut-off points could be identified for these two RSMs in this single-centre cohort.

A model of lifetime health outcomes in cardiovascular disease based on clinical trials and large cohorts

Background and purpose

Cardiovascular disease (CVD) risk of individuals depends on their socio-demographic characteristics, clinical risk factors, and treatments, and strongly influences their quality of life and survival. Individual-based long-term disease models, which aim to more accurately calculate the lifetime consequences, can help to target treatments, develop disease management programmes, and assess the value of new therapies. We present a new micro-simulation CVD model.

Methods

This micro-simulation model was developed using individual participant data from the Cholesterol Treatment Trialists' collaboration (CTT: 118,000 participants; 15 trials) and calibrated (with added socioeconomic deprivation, ethnicity, physical activity, mental illness, cancer and incident diabetes) in the UK Biobank cohort (UKB: 502,000 participants). Parametric survival models estimated risks of key endpoints (myocardial infarction (MI), stroke, coronary revascularisation (CRV), diabetes, cancer and vascular (VD) and nonvascular death (NVD) using participants' age, sex, ethnicity, physical activity, socioeconomic deprivation, smoking history, lipids, blood pressure, creatinine, previous cardiovascular diseases, diabetes, mental illness and cancer at entry and non-fatal incidents of the key endpoints during follow-up. The model integrates the risk equations and enables annual projection of endpoints and survival over individuals' lifetimes. The model was used to project remaining life expectancy across UK Biobank participants.

Results

Nonfatal cardiovascular events and age were the major determinants of CVD risk and, together with incident diabetes and cancer, of individuals' survival. The cumulative incidence of the key endpoints predicted by the CTT-UKB model corresponded well to their observed incidence in the UK Biobank cohort, overall (Figure 1) and in categories of participants by age, sex, prior CVD and CVD risk. Predicted remaining life expectancy across UK Biobank participants without history of CVD ranged between 22 and 43 years in men and between 24 and 46 years in women, depending on their age and CVD risk (Figure 2). Among UK Biobank participants with history of CVD, depending on their age, predicted remaining life expectancy ranged from 20 to 32 years in men and from 26 to 38 years in women.

Conclusion

This new lifetime CVD model accurately predicts morbidity and mortality in a large UK population cohort. It will be made available to provide individualised projections of expected lifetime health outcomes and benefits of treatments.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): UK National Institute for Health Research (NIHR) Health Technology Assessment (HTA) Programme, UK Medical Research Council (MRC), British Heart Foundation Figure 1. Predicted (in black) versus observed (95% CI; in red) incidence of major clinical outcomes in the UK Biobank.Figure 2. Predicted remaining life expectancy of participants in UK Biobank cohort, by age and CVD risk or previous CVD at entry. QRISK, a 10-year CVD risk scoring algorithm for people without previous CVD, recommended for use in the UK National Health Service.

Impact of adverse events on quality of life and hospital costs in secondary cardiovascular disease prevention

Background and purpose

People with atherosclerotic vascular disease remain at high risk of cardiovascular (CVD) events despite effective risk factor management 1. There is little research on impacts of adverse events on quality of life (QoL) and hospital cost to inform evaluations of novel interventions in this population. We estimate QoL and annual hospital costs associated with a range of adverse events of interests using the individual participant data from the Randomized Evaluation of the Effects of Anacetrapib through Lipid Modification (REVEAL) trial.

Methods

Data from the 30,449 participants with atherosclerotic vascular disease receiving effective statin therapy in REVEAL, were used to estimate regression models for participants' hospital costs and QoL using participants' characteristics at entry (socio-demographic, clinical, prior diseases and treatments) and time-updated adverse events. We estimate costs and QoL in the year of an event, and in subsequent years, using stepwise covariate selection (p-value <0.01). Standard errors were adjusted for clustering of participant annual costs.

Hospital episodes were costed (2019 UK£) using the UK Healthcare Resource Groups reference costs 2. One- and two-part generalized linear regression models (GLMs) for annual hospital costs (part 1: logistic model for estimating probability of incurring cost, part 2: GLM with Gaussian, Poisson or Gamma distributions with identity or log links for estimating costs, conditional on incurring any) were compared.

EQ-5D-5L questionnaires, completed by study participants at entry and final follow-up visits in the study, were mapped into QoL utility scores 3. QoL utility at final follow-up was used to estimate QoL decrements of adverse events using GLM linear model and adjusting for QoL at entry in addition to other participants characteristics.

Results

The two-part model with gamma distribution and identity link, indicated by specification tests and model fit statistics, was selected for modelling annual hospital costs (Figure 1). Non-haemorrhagic stroke, non-coronary revascularization, coronary revascularization and incident cancer were associated with highest hospital costs. The QoL model (Figure 2) indicated large QoL decrements associated with non-fatal non-haemorrhagic stroke, heart failure hospitalization, incident cancer and non-coronary revascularization, and comparatively small QoL decrement associated with experiencing non-fatal myocardial infarction.

Conclusion

These cost and QoL models in a well-managed contemporary high CVD risk patient population would assist in assessments of long-term net effects and cost-effectiveness of novel interventions to reduce cardiovascular risk.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Merck Sharp & Dohme and UK Medical Research Council Figure 1Figure 2

Low SARS-CoV-2 Seroprevalence and No Active Infections among Dogs and Cats in Animal Shelters with Laboratory-Confirmed COVID-19 Human Cases among Employees

Human-to-animal and animal-to-animal transmission of SARS-CoV-2 has been documented; however, investigations into SARS-CoV-2 transmission in congregate animal settings are lacking. We investigated four animal shelters in the United States that had identified animals with exposure to shelter employees with laboratory-confirmed COVID-19. Of the 96 cats and dogs with specimens collected, only one dog had detectable SARS-CoV-2 neutralizing antibodies; no animal specimens had detectable viral RNA. These data indicate a low probability of human-to-animal transmission events in cats and dogs in shelter settings with early implementation of infection prevention interventions.

An epidemiological investigation of COVID-19 outbreaks in a group of care homes in Wales, UK: a retrospective cohort study

Background

This study describes the epidemiology of COVID-19 outbreaks in four care homes in terms of spread, severity, presentation and interventions.

Methods

Participants were 100 residents and 102 staff from four co-located care homes in Wales. Data were collected from the homes and Public Health Wales, including demographics, presentations, test status and results, hospital admissions and deaths. Genomic sequencing of confirmed case samples was completed, where possible. Epi-curves, crude attack rates, a Kaplan-Meier survival curve and adjusted hazard ratios were calculated using R.

Results

About 14 confirmed and 43 possible resident cases, 23 confirmed and 47 possible staff cases occurred. Crude attack rates of possible and confirmed cases were 57% (residents) and 69% (staff). Genomic sequencing for 10 confirmed case PCR samples identified at least 5 different UK lineages of COVID-19.42 (42%) residents died, 23 (55%) with COVID-19 or suspected COVID-19 recorded on the death certificate. The hazard ratio for death amongst resident possible and confirmed cases compared to null cases, adjusting for age and sex, was 13.26 (95% CI 5.61–31.34).

Conclusions

There were extensive outbreaks of COVID-19 in these homes with high crude attack rates and deaths. Universal testing and early isolation of residents are recommended.

538 Patient Satisfaction from ENT Phone Consultations During COVID-19

Introduction

Telephone consultations (TCs) have rapidly increased in the outpatient setting due to the coronavirus pandemic. We have implemented a quality improvement project to improve patient satisfaction of TCs in our unit.

Method

This was a prospective complete-cycle project, with online patient satisfaction questionnaires sent following TCs in ENT clinics. This consisted of 28 questions including the Medical Interview Satisfaction Scale (MISS-21).

Based on results and a current literature review, a two-pronged intervention was designed, comprising of staff education and application of a model structured TC framework. A follow-up survey was subsequently undertaken.

Results

100 patient questionnaires were collected (April & June 2020). Significant improvements in MISS-21 scores were seen over the two surveys (p = 0.026). An average MISS-21 score of 114.6 (range 49 – 147) was seen in the first survey, with a mean score of 128.5 (range 79 – 142) seen in the second (maximum score of 147). There was a significantly increased preference for TC over FTF appointments over the two surveys (p = 0.021).

Conclusions

We have shown significant improvements in patient satisfaction and an increased TC preference through use of a structured consultation model. Its potential benefits in infection control and impact on outpatient workload may see TCs persist in the post-coronavirus era.

High-throughput organ-on-chip platform with integrated programmable fluid flow and real-time sensing for complex tissue models in drug development workflows

Drug development suffers from a lack of predictive and human-relevant in vitro models. Organ-on-chip (OOC) technology provides advanced culture capabilities to generate physiologically appropriate, human-based tissue in vitro, therefore providing a route to a predictive in vitro model. However, OOC technologies are often created at the expense of throughput, industry-standard form factors, and compatibility with state-of-the-art data collection tools. Here we present an OOC platform with advanced culture capabilities supporting a variety of human tissue models including liver, vascular, gastrointestinal, and kidney. The platform has 96 devices per industry standard plate and compatibility with contemporary high-throughput data collection tools. Specifically, we demonstrate programmable flow control over two physiologically relevant flow regimes: perfusion flow that enhances hepatic tissue function and high-shear stress flow that aligns endothelial monolayers. In addition, we integrate electrical sensors, demonstrating quantification of barrier function of primary gut colon tissue in real-time. We utilize optical access to the tissues to directly quantify renal active transport and oxygen consumption via integrated oxygen sensors. Finally, we leverage the compatibility and throughput of the platform to screen all 96 devices using high content screening (HCS) and evaluate gene expression using RNA sequencing (RNA-seq). By combining these capabilities in one platform, physiologically-relevant tissues can be generated and measured, accelerating optimization of an in vitro model, and ultimately increasing predictive accuracy of in vitro drug screening.

21 Realist Review of General Practitioners’ Role in Advancing Practice in Care Homes (Grape Study)

Introduction

Many care home residents have high levels of complex needs and their medical care is the responsibility of the general practitioner (GP) in UK. GPs have multiple roles, including gatekeeper for access to other healthcare services and often play a leadership role in the healthcare team. Our aim is to develop realist programme theories for how GPs interact with care homes to facilitate improvements in care of residents.

Method

Using realist review we aimed to describe “what works” for GPs to be involved in improvements in care of residents. Firstly we carried out a scoping review of UK literature and interviewed GP leaders in order to build programme theory. Secondly iterative literature searches were performed in Medline, Embase, CINAHL, PsycInfo, ASSIA, Scopus and many grey literature databases. This international literature is being used to test and refine programme theories and to explore the range of contexts.

Results

A scoping search identified a small number (n = 5) of recent UK articles (2010–19) that described GP input into quality improvement. To gain insight into context, observational studies (n = 4 in UK and Ireland) were identified which described concerns about workload and resource constraints. To develop initial programme theories, we conducted interviews with 6 GP leaders, where themes of risk and specialism were identified. We are developing the following mechanisms within programme theory: where GP profession have an ownership of the agenda, this encourages GP involvement. In other initiatives, the mechanism may be a trusting relationship between GP and another practitioner, eg pharmacist.

Conclusion

Many reported projects which aim to improve care quality in care homes do not describe how the initiative relates to GP practice. We have identified mechanisms which, when present, may cause GPs to contribute leadership and medical expertise, and thus lead to successful outcomes for residents.

Idiopathic systemic capillary leak syndrome (Clarkson's disease) presenting with recurrent hypovolemic shock

A 49-year old male with a past medical history of myocardial infarction and compartment syndromes requiring fasciotomies presented on five occasions with hypovolemic shock. We describe his admissions and presumptive diagnoses which required large volumes of intravenous fluids, admission to intensive care for vasopressors and renal replacement therapy. The presentations were always precipitated by a prodrome of fatigue and pre-syncopal episodes. On his last admission, a diagnosis of Idiopathic systemic capillary leak syndrome (ISCLS), also known as Clarkson's Disease, was reached. He is currently receiving high dose intravenous immunoglobulins on a monthly basis.

'Secondary biofilms' could cause failure of peracetic acid high-level disinfection of endoscopes

INTRODUCTION

The reduced susceptibility of biofilms to disinfectants presents a challenge to the successful reprocessing of medical equipment. This study examined the effect of residual biomass remaining after previous disinfection with peracetic acid (PAA) on the tolerance of subsequent mature Pseudomonas aeruginosa biofilms to PAA. The effect of enzymatic degradation of specific components of the extracellular polymeric substance (EPS) of P. aeruginosa biofilm on the effectiveness of PAA disinfection was also evaluated.

METHODS

The susceptibility of biofilm grown on the biomass of PAA-killed biofilm to PAA was compared with the PAA susceptibility of biofilm grown in wells of a 24-well plate by evaluating their viability using the plate count assay. The effect of PAA on biofilm biomass was measured using crystal violet quantification of total biofilm biomass, while its effect on the polysaccharide and protein components of biofilm EPS was quantified using the phenol-sulphuric acid assay or Bradford assay, respectively. A confocal microscope was used to visualize the distribution of living and dead cells in biofilms grown on residual biofilm biomass.

FINDINGS

The presence of residual biomass from previously disinfected biofilms significantly enhanced the tolerance of subsequent biofilms. A 96-h-old 'secondary biofilm' formed on disinfected biomass survived PAA concentrations of 4000 ppm, which exceeds the concentrations used in practice for high-level disinfection.

CONCLUSION

These observations indicate that, under certain circumstances, recolonization of residual EPS can cause failure of disinfection of medical equipment such as endoscopes, and emphasizes the importance of cleaning endoscopes prior to disinfection.

Patient satisfaction from ENT telephone consultations during the coronavirus disease 2019 pandemic

BACKGROUND

Telephone consultations have rapidly increased in the out-patient setting because of the coronavirus pandemic. A quality improvement project was implemented to improve patient satisfaction of telephone consultations in our unit.

METHODS

This was a prospective complete-cycle project. Patient satisfaction questionnaires were sent to patients following telephone consultations in ENT clinics. Based on a literature review and initial results, clinicians were encouraged to follow a structured consultation format. A second questionnaire survey was conducted following its implementation.

RESULTS

One hundred patient questionnaires were collected during the survey (April and June 2020). There was significant improvement over the two surveys in terms of satisfaction scores (p = 0.026), along with a significantly increased preference for telephone consultations over face-to-face consultations (p = 0.021).

CONCLUSION

This study showed significant improvement in patient satisfaction and an increased telephone consultation preference through the use of a structured consultation model. The potential benefits in terms of infection control and impact on out-patient workload may see telephone consultations persist in the post-coronavirus era.