Taxonomic and Metagenomic Analyses Define the Development of the Microbiota in the Chick

Chicks are ideal to follow the development of the intestinal microbiota and to understand how a pathogen perturbs this developing population. Taxonomic/metagenomic analyses captured the development of the chick microbiota in unperturbed chicks and in chicks infected with Salmonella enterica serotype Typhimurium (STm) during development. Taxonomic analysis suggests that colonization by the chicken microbiota takes place in several waves. The cecal microbiota stabilizes at day 12 posthatch with prominent Gammaproteobacteria and Clostridiales. Introduction of S. Typhimurium at day 4 posthatch disrupted the expected waves of intestinal colonization. Taxonomic and metagenomic shotgun sequencing analyses allowed us to identify species present in uninfected chicks. Untargeted metabolomics suggested different metabolic activities in infected chick microbiota. This analysis and gas chromatography-mass spectrometry on ingesta confirmed that lactic acid in cecal content coincides with the stable presence of enterococci in STm-infected chicks. Unique metabolites, including 2-isopropylmalic acid, an intermediate in the biosynthesis of leucine, were present only in the cecal content of STm-infected chicks. The metagenomic data suggested that the microbiota in STm-infected chicks contained a higher abundance of genes, from STm itself, involved in branched-chain amino acid synthesis. We generated an ilvC deletion mutant (STM3909) encoding ketol-acid-reductoisomerase, a gene required for the production of l-isoleucine and l-valine. ΔilvC mutants are disadvantaged for growth during competitive infection with the wild type. Providing the ilvC gene in trans restored the growth of the ΔilvC mutant. Our integrative approach identified biochemical pathways used by STm to establish a colonization niche in the chick intestine during development. IMPORTANCE Chicks are an ideal model to follow the development of the intestinal microbiota and to understand how a pathogen perturbs this developing population. Using taxonomic and metagenomic analyses, we captured the development of chick microbiota to 19 days posthatch in unperturbed chicks and in chicks infected with Salmonella enterica serotype Typhimurium (STm). We show that normal development of the microbiota takes place in waves and is altered in the presence of a pathogen. Metagenomics and metabolomics suggested that branched-chain amino acid biosynthesis is especially important for Salmonella growth in the infected chick intestine. Salmonella mutants unable to make l-isoleucine and l-valine colonize the chick intestine poorly. Restoration of the pathway for biosynthesis of these amino acids restored the colonizing ability of Salmonella. Integration of multiple analyses allowed us to correctly identify biochemical pathways used by Salmonella to establish a niche for colonization in the chick intestine during development.

The impact of signposting and group support pathways on a community-based physical activity intervention grounded in motivational interviewing

BACKGROUND

Brief advice is recommended to increase physical activity (PA) within primary care. This study assessed change in PA levels and mental well-being after a motivational interviewing (MI) community-based PA intervention and the impact of signposting (SP) and social action (SA) (i.e. weekly group support) pathways.

METHODS

Participants (n = 2084) took part in a community-based, primary care PA programme using MI techniques. Self-reported PA and mental well-being data were collected at baseline (following an initial 30-min MI appointment), 12 weeks, 6 months and 12 months. Participants were assigned based upon the surgery they attended to the SP or SA pathway. Multilevel models derived point estimates and 95% confidence intervals for outcomes at each time point and change scores.

RESULTS

Participants increased PA and mental well-being at each follow-up time point through both participant pathways and with little difference between pathways. Retention was similar between pathways at 12 weeks, but the SP pathway retained more participants at 6 and 12 months.

CONCLUSIONS

Both pathways produced similar improvements in PA and mental well-being; however, the addition of a control would have provided further insight as to the effectiveness. Due to lower resources yet similar effects, the SP pathway could be incorporated to support PA in primary care settings.

The impact of signposting and group support pathways on a community-based physical activity intervention grounded in motivational interviewing

BACKGROUND

Brief advice is recommended to increase physical activity (PA) within primary care. This study assessed change in PA levels and mental well-being after a motivational interviewing (MI) community-based PA intervention and the impact of signposting (SP) and social action (SA) (i.e. weekly group support) pathways.

METHODS

Participants (n = 2084) took part in a community-based, primary care PA programme using MI techniques. Self-reported PA and mental well-being data were collected at baseline (following an initial 30-min MI appointment), 12 weeks, 6 months and 12 months. Participants were assigned based upon the surgery they attended to the SP or SA pathway. Multilevel models derived point estimates and 95% confidence intervals for outcomes at each time point and change scores.

RESULTS

Participants increased PA and mental well-being at each follow-up time point through both participant pathways and with little difference between pathways. Retention was similar between pathways at 12 weeks, but the SP pathway retained more participants at 6 and 12 months.

CONCLUSIONS

Both pathways produced similar improvements in PA and mental well-being; however, the addition of a control would have provided further insight as to the effectiveness. Due to lower resources yet similar effects, the SP pathway could be incorporated to support PA in primary care settings.

RADT-02. IMPACT OF SINGLE AND DUAL IMMUNE CHECKPOINT BLOCKADE ON RISK OF RADIATION NECROSIS AND LOCAL CONTROL AMONG PATIENTS WITH BRAIN METASTASES TREATED WITH STEREOTACTIC RADIOSURGERY

PURPOSE

Single and dual immune checkpoint inhibition (ICPI) are common treatment options for patients, particularly with melanoma and non-small cell lung cancer (NSCLC). While data suggest a cancer control benefit of combining stereotactic radiosurgery (SRS) and ICPI, we hypothesized that concurrent dual ICPI and SRS increases risk for radiation necrosis (RN).

METHODS

We retrospectively reviewed patients with metastatic melanoma or NSCLC treated with SRS for intact brain metastases from 2014-2020. Patients were stratified by receipt of dual ICPI, single ICPI, and SRS alone. Concurrent ICPI was defined as treatment within 30 days of SRS. RN and local control (LC) were biopsy confirmed or determined radiographically and longitudinally, in combination with clinical assessment and steroid use. Kaplan-Meier estimates were used to compare rates of RN and LC between cohorts.

RESULTS

673 brain lesions from 93 patients met inclusion criteria [median (Q1, Q3): 5.0 (2.0-10.0) lesions per patient]. Median follow-up was 8.1 months (95% CI: 7.3-8.7). Histologies included melanoma (53.5%), adenocarcinoma NSCLC (27.3%), squamous cell NSCLC (6.1%), and NSCLC NOS (6.1%). 88 lesions from 25 patients (27%) developed RN and 11 (13%) were biopsy-proven. ICPI use was enriched among lesions that developed RN (85.2%) versus those that did not (19.8%). RN was associated with concurrent ICPI (p< 0.001). Freedom from RN at 6 months was 80% for dual ICPI, 82% for single ICPI, and 97% for SRS alone; 12-month rates were 78% in each ICPI cohort and 95% with SRS alone (p=0.0002). LC differed among dual (97.5%), single (88.7%), and no ICPI (79.7%, p < 0.001). There was a trend toward improved LC with RN (96.6% vs 91.8%; p=0.087).

CONCLUSIONS

In a large cohort of brain metastases, we observed increased risk of RN and improved LC with SRS plus concurrent dual or single ICPI. Awareness of these associations is critical for patient management.

RADT-23. MODALITY-SPECIFIC CNS INJURY FOLLOWING PROTON VS PHOTON BEAM RADIOTHERAPY IN GLIOMA

BACKGROUND

CNS injury following brain-directed radiotherapy (RT) is common and may mimic disease progression. Dosimetric advantages of protons (PRT) over photons (XRT) minimize radiation to healthy brain, potentially limiting radiotoxic sequelae. We characterized CNS radiotoxicity i.e., radiation-induced leukoencephalopathy (RIL), brain tissue necrosis (TN), and cerebral microbleeds (CMB), during progression-free survival (PFS) periods in glioma patients irradiated with PRT or XRT.

METHODS

34 patients (19 male; mean age = 40.10y) with grade 2/3 gliomas treated by partial cranial RT were stratified by RT modality [XRT(n = 17) vs PRT(n = 17)] and matched on 11 criteria [age, sex, tumor type/location/laterality, mutational status (IDH; 1p19q deletion), concurrent/adjuvant chemotherapy, radiation dose/fractions] for retrospective analysis. Radiotoxicity was characterized longitudinally until 3 years post-RT via analysis of serial MRI T2/FLAIR- (RIL), T1+Contrast- (TN), and Susceptibility (CMB)-weighted sequences. RIL was rated using a novel scoring system with embedded Fazekas scale (intraclass correlation coefficient > 0.9), at global (whole-brain) and hemispheric levels.

RESULTS

Analysis of delayed radiotoxicity at 3 years post-RT identified significant modality-specific differences. While both groups developed moderate-to-severe RIL [62% (XRT) and 72% (PRT)], XRT resulted in greater RIL injury dynamics (i.e., average % change between 1 and 3 years post-RT) in the contralesional hemisphere [F(1, 31) = 4.32, p < .05]. Conversely, PRT was associated with higher TN incidence [6%(XRT) vs 18%(PRT) z = - 2.22, p < 0.03, two-tailed]. Finally, while CMB incidence [76%(XRT) vs 71%(PRT)] and burden [mean #CMB: 4.3(XRT) vs 4.2(PRT)] were comparable, lesion-to-radiation field (RF)-correlation identified preferential CMB clustering at RF margins with PRT [X2(2, N =200)= 8.8, p < .02].

CONCLUSIONS

CNS radiotoxicity is common and progressive in glioma patients. Injury patterns suggest radiation modality specificity as RIL, TN, and CMB exhibit unique spatiotemporal differences following XRT vs PRT, likely reflecting dosimetric and biological differences between protons and photons. The impact of such sequelae on cognition is subject of current investigation.

NCOG-09. RADIATION INDUCED CEREBRAL VOLUME LOSS AND CEREBROVASCULAR DISEASE RISK IN SURVIVORS OF GRADE 2 AND 3 GLIOMAS

INTRODUCTION

Cranial irradiation with protons (PRT) as compared with photons (PHT) reduces radiation exposure to healthy brain tissue and may mitigate early- and late-delayed complications. Prior work in our group has demonstrated that PRT results in less brain atrophy over 2 years post-treatment as compared with PHT. It is unknown whether individual factors, such as cerebrovascular disease risk (CVDR; known to be important in post-RT brain changes), interacts with treatment type to affect brain volume change.

METHODS

Patients treated with PRT for grade 2 or 3 gliomas were meticulously matched to patients treated with PHT using an eleven-tiered criterion (i.e., age, sex, tumor type, tumor location, laterality, IDH mutation status, 1p19q deletion status, concurrent chemotherapy, adjuvant chemotherapy, total Gy dose, and number of fractions). Brain volume changes were evaluated by measuring changes in ventricular size in the contralesional hemisphere (to reduce impact of tumor-related changes on volumetric measurements). A CVDR score was created, incorporating history of hypertension, hyperlipidemia, smoking, and diabetes. Correlation and multiple regression analyses examined the relationship between CVDR and brain volume loss over 2 years.

RESULTS

Mann-Whitney tests of independence showed no significant differences in CDVR between PHT and PRT treatment groups. Cerebral volume loss correlated significantly with CVDR (r =.404, p =0.02) and treatment type (r=-.366, p =0.036). Age and gender were unrelated to volume loss. A multiple regression analysis that included treatment type (PHT, PRT) and CVDR accounted for 23% of the variance in volume loss, F(2, 32) = 4.383, p < .021.

CONCLUSION

The current study demonstrates that neurotoxicity of radiation therapy is related to both CVDR and radiation treatment type. Longitudinal data, including a larger sample size, are warranted to confirm these preliminary findings. Inclusion of routine neuropsychological outcome data will be critical to understand the functional significance of these results.

Standards of Care for the Health of Transgender and Gender Diverse People, Version 8

Background: Transgender healthcare is a rapidly evolving interdisciplinary field. In the last decade, there has been an unprecedented increase in the number and visibility of transgender and gender diverse (TGD) people seeking support and gender-affirming medical treatment in parallel with a significant rise in the scientific literature in this area. The World Professional Association for Transgender Health (WPATH) is an international, multidisciplinary, professional association whose mission is to promote evidence-based care, education, research, public policy, and respect in transgender health. One of the main functions of WPATH is to promote the highest standards of health care for TGD people through the Standards of Care (SOC). The SOC was initially developed in 1979 and the last version (SOC-7) was published in 2012. In view of the increasing scientific evidence, WPATH commissioned a new version of the Standards of Care, the SOC-8. Aim: The overall goal of SOC-8 is to provide health care professionals (HCPs) with clinical guidance to assist TGD people in accessing safe and effective pathways to achieving lasting personal comfort with their gendered selves with the aim of optimizing their overall physical health, psychological well-being, and self-fulfillment. Methods: The SOC-8 is based on the best available science and expert professional consensus in transgender health. International professionals and stakeholders were selected to serve on the SOC-8 committee. Recommendation statements were developed based on data derived from independent systematic literature reviews, where available, background reviews and expert opinions. Grading of recommendations was based on the available evidence supporting interventions, a discussion of risks and harms, as well as the feasibility and acceptability within different contexts and country settings. Results: A total of 18 chapters were developed as part of the SOC-8. They contain recommendations for health care professionals who provide care and treatment for TGD people. Each of the recommendations is followed by explanatory text with relevant references. General areas related to transgender health are covered in the chapters Terminology, Global Applicability, Population Estimates, and Education. The chapters developed for the diverse population of TGD people include Assessment of Adults, Adolescents, Children, Nonbinary, Eunuchs, and Intersex Individuals, and people living in Institutional Environments. Finally, the chapters related to gender-affirming treatment are Hormone Therapy, Surgery and Postoperative Care, Voice and Communication, Primary Care, Reproductive Health, Sexual Health, and Mental Health. Conclusions: The SOC-8 guidelines are intended to be flexible to meet the diverse health care needs of TGD people globally. While adaptable, they offer standards for promoting optimal health care and guidance for the treatment of people experiencing gender incongruence. As in all previous versions of the SOC, the criteria set forth in this document for gender-affirming medical interventions are clinical guidelines; individual health care professionals and programs may modify these in consultation with the TGD person.

MMAP-07 IMPACT OF SINGLE AND DUAL IMMUNE CHECKPOINT BLOCKADE ON RISK OF RADIATION NECROSIS AMONG PATIENTS WITH BRAIN METASTASES TREATED WITH STEREOTACTIC RADIOSURGERY

PURPOSE

While stereotactic radiosurgery (SRS) is often an efficacious treatment for brain metastases, it carries a significant risk of radionecrosis (RN). Single and dual immune checkpoint inhibition (ICPI) have emerged as common treatment options for many patients, particularly those with melanoma and non-small cell lung cancer (NSCLC). While data suggest a cancer control benefit of combining SRS and ICPI, we hypothesized that concurrent receipt of dual ICPI with SRS increases the risk for RN.

METHODS

We performed a retrospective review of serial patients with metastatic melanoma or NSCLC treated with SRS for intact brain metastases from 2014-2020 at our single institution. Patients were stratified by receipt of dual vs. single ICPI vs. SRS alone. RN was biopsy confirmed or determined radiographically, in combination with clinical assessment and steroid use. Kaplan-Meier estimates were used to compare rates of RN between cohorts.

RESULTS

673 brain lesions from 93 patients met inclusion criteria [median (Q1, Q3): 5.0 (2.0-10.0) lesions per patient]. Median follow-up of lesions was 8.1 months (95% CI: 7.3, 8.7). Most (82.8%) lesions were supratentorial and histologies included melanoma (53.5%), adenocarcinoma NSCLC (27.3%), squamous cell NSCLC (6.1%), and NSCLC NOS (6.1%). In the entire cohort, 88 lesions from 25 patients (27%) developed RN. 77 (87%) lesions were diagnosed clinico-radiographically and 11 (13%) were biopsy-proven. ICPI use was highly enriched among lesions that developed RN (85.2%) versus those that did not (19.8%). Freedom from RN at 6 months was 80% for dual ICPI, 82% for single ICPI, and 97% for SRS alone; 12 month rates were 78% in each of the ICPI cohorts and 95% with SRS alone (P=0.0002).

CONCLUSIONS

In a large cohort of SRS-treated brain metastases, we observed an increased risk of RN among patients who received either dual or single ICPI concurrently with SRS.

Six year follow-up data on a leadless pacing system real life experience in comparison to data of the prospective trial

Funding Acknowledgements

Type of funding sources: None.

Introduction

The Micra™ leadless intracardiac pacing system has been introduced and implemented into clinical routine in 2015, with its next generation MICRA AV ™ in 2020. Feasibility, implantation safety, and acute success have been proven in the setting of controlled studies. Even apart from controlled studies, this new technology was beneficial for the individual patient. We aimed to report our single center follow-up (FU) data with a follow-up of up to six years.

Methods

In 246 patients (134 men; age: 79±8 y), Micra™ implantation was performed.

Pacemaker interrogation was performed one to seven days after implantation and during FU (1; 3; 6, then every 6 month) up to 72 months. Data were assessed in a real-life setting and compared with existing data of a controlled prospective trial.

Results

The implantation was successful in all 246 attempts with only one pericardial effusion as major complication. During follow up there were two patients developing severe heart failure symptoms resulting in an implantation of a CRT-device and switching of the leadless pacemaker system.

The average acute thresholds, sensing and impedance after system release were: 0.62±0.45V@0.24ms; 10,55±3,61mV and 697±178Ohm. During follow up of up to 5 years neither, pacemaker failure, nor infections were reported. Measurements were reevaluated for long-term thresholds, sensing and impedance: 0.44 ± 0.07V @ 0.24 ms; 17,25 ±4,65 mV and 572 ± 80 Ohm. During five years, no significant changes from acute to long-term measurements were detectable. In comparison to the controlled trial, our measurements of this real-life cohort were very similar.

Conclusion

In a real-life setting, the implantation of the leadless Micra™ system demonstrates a high rate of implantation success without major complications. We were also able to show stable long-term system parameters in the clinical setting of up to six years of follow up with a very good battery longevity of about 12 years.

A Thermodynamic Model for Interpreting Tryptophan Excitation-Energy-Dependent Fluorescence Spectra Provides Insight Into Protein Conformational Sampling and Stability

It is now over 30 years since Demchenko and Ladokhin first posited the potential of the tryptophan red edge excitation shift (REES) effect to capture information on protein molecular dynamics. While there have been many key efforts in the intervening years, a biophysical thermodynamic model to quantify the relationship between the REES effect and protein flexibility has been lacking. Without such a model the full potential of the REES effect cannot be realized. Here, we present a thermodynamic model of the tryptophan REES effect that captures information on protein conformational flexibility, even with proteins containing multiple tryptophan residues. Our study incorporates exemplars at every scale, from tryptophan in solution, single tryptophan peptides, to multitryptophan proteins, with examples including a structurally disordered peptide, de novo designed enzyme, human regulatory protein, therapeutic monoclonal antibodies in active commercial development, and a mesophilic and hyperthermophilic enzyme. Combined, our model and data suggest a route forward for the experimental measurement of the protein REES effect and point to the potential for integrating biomolecular simulation with experimental data to yield novel insights.

Real-world experience on the safety and effectiveness of Micra TPS in patients with pre-existing in situ CIEDs

Background

The Micra pre-market study showed that the Micra transcatheter pacing system could be safely implanted in patients with pacing indications. Patients with pre-existing cardiac implantable electronic devices (CIED) were excluded from this clinical trial; however, this group of patients might benefit from a leadless pacemaker especially when a lead fails or after incidence of system-related infections.

Objective

To determine the outcome of patients with a pre-existing CIED or lead that remains in situ at the time of Micra implant attempt.

Methods

Patients who had a pre-existing CIED and/or lead at the time of Micra implantation attempt were identified from the Micra Post-Approval Registry and Micra Acute Performance studies. Baseline characteristics were summarized, and a Fine-Gray competing risk model was used to compare risk for major complication through 24 months for patients with and without a pre-existing CIED.

Results

Of the 2323 patients included in the analysis, 111 patients had a pre-existing CIED or lead at the time of Micra implantation attempt that remained in situ. Types of pre-existing devices included 81 pacemakers (45 single chamber, 32 dual chamber, 4 of unknown type), 10 ICDs (2 single chamber, 2 dual chamber, 6 unknown type), 10 CRT devices (6 CRT-P, 4 CRT-D), 3 generators of unknown type, and 7 patients had only leads remaining. Patients with pre-existing devices were younger and less likely to have a pacing indication of bradyarrhythmia with atrial fibrillation compared to patients without pre-existing devices (p<0.001 for both). Patients with prior devices were more likely to have a condition precluding implant of a transvenous pacemaker (67.6% vs. 21.3%, p<0.001). The presence of a pre-existing CIED did not impact the outcome of the Micra TPS implant procedure: implant success was >99% for both cohorts. Mean follow-up duration was 21.2±14.3 months (range 0–56) for pre-existing devices patients and 23.3±15.8 months (range 0–62) for other patients. The rate of major complications through 24 months was 1.8% for patients with and 3.8% for patients without prior devices (p=0.36). There were no major complications related to device malfunction or device-device interaction. There were 6 system revisions in 4 patients with preexisting devices and 52 revisions in 51 patients without preexisting devices. Pacing thresholds for patients with and without prior devices were similar at implant (0.72 and 0.63, respectively; p=0.31) and remained stable through 12 months.

Conclusion

Micra can be safely and successfully implanted in patients with a pre-existing CIED remaining in situ. It should be considered a treatment option for patients in whom CIED extraction may be deemed high risk.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Medtronic, Inc. Risk of major complications

Population pharmacokinetics of intravenous and oral ciprofloxacin in children to optimize dosing regimens

PURPOSE

This study aimed to characterize pharmacokinetics of intravenous and oral ciprofloxacin in children to optimize dosing scheme.

METHODS

Children treated with ciprofloxacin were included. Pharmacokinetics were described using non-linear mixed-effect modelling and validated with an external dataset. Monte Carlo simulations investigated dosing regimens to achieve a target AUC_0-24 h/MIC ratio ≥ 125.

RESULTS

A total of 189 children (492 concentrations) were included. A two-compartment model with first-order absorption and elimination best described the data. An allometric model was used to describe bodyweight (BW) influence, and effects of estimated glomerular filtration rate (eGFR) and age were significant on ciprofloxacin clearance.

CONCLUSION

The recommended IV dose of 10 mg/kg q8h, not exceeding 400 mg q8h, would achieve AUC_0-24 h to successfully treat bacteria with MICs ≤ 0.25 (e.g. Salmonella, Escherichia coli, Proteus, Haemophilus, Enterobacter, and Klebsiella). A dose increase to 600 mg q8h in children > 40 kg and to 15 mg/kg q8h (max 400 mg q8h, max 600 mg q8h if augmented renal clearance, i.e., eGFR > 200 mL/min/1.73 m²) in children < 40 kg would be needed for the strains with highest MIC (16% of Pseudomonas aeruginosa and 47% of Staphylococcus aureus). The oral recommended dose of 20 mg/kg q12h (not exceeding 750 mg) would cover bacteria with MICs ≤ 0.125 but may be insufficient for bacteria with higher MIC and a dose increase according bodyweight and eGFR would be needed. These doses should be prospectively confirmed, and a therapeutic drug monitoring could be used to refine them individually.

A leadless pacemaker in the real-world setting: Patient profile and performance over time

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Medtronic, Inc.

OnBehalf

Micra Acute Performance EMEA Investigators

Background

The first in-man implant of the Micra leadless pacemaker occurred in December 2013. While prior trials demonstrated a high implant success rate and favorable safety and efficacy results; whether the patient population and outcomes have changed over time is not well studied.

Purpose

To characterize the evolution of patient profile and outcomes for patients receiving a leadless pacemaker through the pre-market and post-market environment.

Methods

Patients undergoing a Micra leadless pacemaker implant attempt from the initial Micra Investigational Device Exemption [IDE] and current Micra studies (Micra post-approval registry [PAR], Micra acute performance [MAP] study) were analyzed. Patient characteristics and pericardial effusions regardless of severity were summarized.

Results

The 3466 patients included in the analysis underwent a Micra implant attempt and were enrolled during consecutive timeframes: patients from the Micra IDE study (n = 726) underwent a Micra implant attempt from 2013-2015, patients from the PAR (n = 1814) from 2015-2018, and patients from Micra MAP cohort (n = 926) from 2018 – 2020.  Implant success was &gt;99.0% in all 3 studies. Median age ranged from 78 – 79 years among the 3 studies without significant difference. There were more patients requiring dialysis in the MAP cohort compared to the PAR or IDE cohorts (10.3%, 7.9%, and 3.9%, respectively; P &lt; 0.001), but fewer patients with congestive heart failure (8.3%, 13.1%, and 18.0%; P &lt; 0.001). Pacing indication was significantly different between the studies, with fewer patients in MAP having an indication of bradyarrhythmia associated with atrial fibrillation (AF) and more having an indication associated with atrioventricular block without AF (P &lt; 0.001). The number of patients considered to be precluded for a transvenous pacemaker implant increased significantly from the initial IDE study to the PAR and MAP studies (6.2%, 23.9%, and 44.1%, respectively, P &lt; 0.001).  Implant site placement was mostly apical for the IDE but shifted to mostly septal placement in the PAR and MAP (septal placement: 33.3%, 64.0%, and 79.5%, respectively). The rate of pericardial effusion regardless of severity was 1.79% (n = 13) in the IDE, 0.83% (n = 15) in the PAR, and 0.97% (n = 9) in MAP (figure). Mean pacing thresholds among MAP EMEA patients were low (0.61 ± 0.40V) at implant and remained stable through 12 months (0.62 +/- 0.41V).

Conclusion

Despite patient differences over time, the Micra leadless pacemaker was implanted with a high success rate and a low perforation rate, in-line with prior reports. Abstract Figure. Pericardial effusion rate by study

417 COVID-19 and the Return to Head and Neck Outpatient Activity in The United Kingdom: What Is the New Normal?

Background

We aim to investigate current head and neck outpatient practices across the United Kingdom during the COVID-19 pandemic.

Method

A cross-sectional study comprising of an online 20-item survey was emailed to members of the British Association of Head and Neck Oncologists (BAHNO). Topics covered included safety measures, protective equipment used and protocols around the use of flexible nasendoscopy (FNE) in clinic.

Results

117 participants completed the survey covering 66 Trusts across the UK. There was a significant reduction in face-to-face clinic patients compared to pre-pandemic numbers. Room down-time after FNE ranged from 0-6 hours and there was a significant increase in allocated down-time after the patient had coughed or sneezed. Natural ventilation existed in 36% of clinics and the majority of responders didn’t know the calculated Air Change Per Hour (ACPH) of the room (77%). Where ACPH was known, it often did not match the allocated room down-time.

Conclusions

Adaptations are being made across the UK to maintain staff and patient safety, but more can still be done by liaising with hospital infectious diseases and the hospital estates team to clarify outpatient protocols.Outpatient activity will likely remain limited and alternative strategies will need to develop to manage the backlog in face-to-face clinics.

[Echocardiographic assessment of myocardial function during His bundle and right ventricular pacing]

INTRODUCTION

In patients with pacemaker (PM) therapy, His bundle stimulation (HBS) may lead to a more synchronous activation of the left ventricle (LV) than conventional right ventricular stimulation (RVS). In this study, we investigated to which extent this effect can be objectified by means of contemporary echocardiographic functional imaging.

METHODS

In all, 15 RVS patients (6 women, mean age 76.6 ± 4.1 years) and 15 HBS patients (6 women, mean age 74.6 ± 3.7 years) underwent echocardiography with and without cardiac pacing. Besides LV end-diastolic volume (EDV), ejection fraction (EF), and global strain (GLS), we measured global and regional myocardial work and LV efficiency based on noninvasive pressure-strain loops.

RESULTS

In all HBS patients, optimization of PM settings resulted in immediate changes in myocardial function parameters. With pacing, RVS patients showed a higher decrease in EF and GLS than HBS patients. Global LV work and LV work efficiency decreased significantly only in RVS patients.

CONCLUSION

Changes in regional and global myocardial function can by proven and quantified by functional echocardiography. In patients under PM therapy, HBS shows functional advantages in comparison to conventional RVS.

P1468Four years follow-up of leadless pacing system single center real life experience compared to data of the prospective trial

Funding Acknowledgements

none

OnBehalf

Cologne Registry

Introduction

The Micra™ leadless intracardiac pacing system has been introduced and implemented into clinical routine more than three years ago. Feasibility, implantation safety and acute success have been proven in the setting of controlled studies. Additionally few real- life and post-implantation data exist.  We aimed to report our single center follow-up (FU) data in comparison with the results of the prospective controlled  Micra™- studie.

Methods

In 112 patients (69 men; age: 79 ± 10 y) successful Micra™ implantation was performed.Pacemaker interrogation was performed one to seven days after implantation and during FU (1; 3; 6, than every 6 month) up to 48 month. Data were assessed in a real-life setting and compared with existing data of the controlled prospectiv trial.

Results

The implantation was successful in all 112 attempts without procedure or device-related major complications. During Follow up there was one patient developing severe heart failure symptoms resulting in an implantation of a CRT-device and switching of the leadless pacemaker system.

The average acute thresholds, sensing and impedance after system release were: 0.63 ± 0.42V@0.24ms; 9,94 ± 3,61mV and 705 ± 166 Ohm. During follow up of up to 4 years neither, pacemaker failure, nor infections were reported. Measurements were reevaluated for long-term thresholds, sensing and impedance: 0.54 ± 0.16V @ 0.24 ms; 16,15 ±4,22 mV and 579 ± 133 Ohm. In the first three years no significant changes from acute to long-term measurements were detectable.  In comparison to the data of the controlled trial the measurements of our real-life cohort was very similar.

Conclusion

In a real life setting the implantation of the leadless Micra™ system demonstrates high rate of implant success without major complications. Also shown were stable long-term system parameters in the clinical setting of up to two years of follow up. These data of every day clinical practice support the findings of the prospectiv trials.

553 Acute re-distribution of regional left ventricular work by cardiac resynchronization therapy determines long-term remodelling

Background

In patients with dilated cardiomyopathy and left bundle branch block (LBBB), different regions of the left ventricle (LV) have been shown to perform different amounts of work. In this study, we investigate the acute impact of cardiac resynchronization therapy (CRT) on regional LV work distribution and its relation to long-term reverse-remodelling.

Methods

We recruited 140 heart failure patients, referred for CRT. Regional myocardial work was calculated from non-invasive echocardiographic segmental stress-strain-loop-area before and immediately after CRT. The magnitude of volumetric reverse-remodelling was determined from the change in LV end-systolic volume (ESV), 11 ± 3 months after implantation. Characteristics of patients with the lowest and highest quartile of LV ESV reverse remodelling (LV ESV reduction of less than 10% and LV ESV reduction of more than -48%) were compared.

Results

Before CRT, myocardial work showed significant differences among the walls of the LV (Figure A). CRT caused an acute re-distribution of myocardial work, on average with most increase in the septum and most decrease laterally (all walls p &lt; 0.05) and lead to a homogeneous work distribution (Figure B). The acute change in the difference between lateral and septal wall work (Δ Lateral-to-septal work) correlated significantly with LV ESV reverse-remodelling (r = 0.63, p &lt; 0.0001). The smallest changes in work were seen in the patients with the least LV ESV reverse remodelling (Figure C, red markers), while patients with the most LV ESV reverse remodelling showed the largest changes in work (Figure C, green markers). In multivariate linear regression analysis, including conventional parameters such as pre-implant QRS duration, LV ejection fraction, LV end-diastolic volume and global longitudinal strain, the re-distribution of work across the septal and lateral walls appeared as the strongest determinant of volumetric reverse-remodelling after CRT (R²=0.393, p &lt; 0.0001).

Conclusions

The acute re-distribution of regional myocardial work between the septal and lateral wall of the left ventricle is an important determinant of long term reverse-remodelling after CRT-implantation. Our data suggest that modification of regional loading is the mode of action of CRT treatment.

Abstract 553 Figure.

Assessing the efficacy and cost of detergents used in a primary care automated washer disinfector

Background

Cleaning of re-usable medical devices is a critical control point in the decontamination cycle, although defined end-points of the process are controversial.

Objective

Investigate cleaning efficacy and cost of different detergent classes in an automated washer disinfector (AWD) designed for dental practice.

Methods

Loads comprised test soiled dental hand instruments in cassettes and extraction forceps. Residual protein assayed using the International standard method (ISO 15883-5:2005) 1% SDS elution with ortho-phthalaldehyde (OPA) or GBox technology (on instrument OPA analysis). Short (60 minutes) and long (97 minutes) AWD cycles were used with four different classes of detergents, tap water and reverse osmosis water.

Results

SDS elution analysis (N = 612 instruments) demonstrated four detergents with both wash cycles achieved equivalent cleanliness levels and below a threshold of 200 μg protein/instrument. GBox methodology (N = 575) using UK Department of Health threshold of 5 μg/instrument side demonstrated that tap water performed with the greatest efficacy for all types of instruments and cycle types.

Conclusions

Using International standard methodology, different detergent classes had equivalence in cleaning efficacy. Cheaper detergents used in this study performed with similar efficacy to more expensive solutions. Findings emphasise the importance of validating the detergent (type and concentration) for each AWD.

P1238Acute re-distribution of myocardial work by cardiac resynchronization therapy determines long-term remodelling of the left ventricle

Background

In patients with dilated cardiomyopathy and left bundle branch block (LBBB), different regions of the left ventricle (LV) have been shown to perform different amounts of work. In this study, we investigate the acute impact of cardiac resynchronization therapy (CRT) on regional LV work distribution and its relation to long-term reverse-remodelling.

Methods

We recruited 130 heart failure patients, referred for CRT. Regional myocardial work was calculated from non-invasive echocardiographic segmental stress-strain-loop-area before and immediately after CRT. The magnitude of volumetric reverse-remodelling was determined from the change in LV end-systolic volume (ESV), 11±2 months after implantation. Characteristics of patients with the lowest and highest quartile of LV ESV reverse remodelling (ΔLV ESV <−9% and ΔLV ESV >−48%) were compared.

Results

Before CRT, myocardial work showed significant differences among the walls of the LV (Figure 1A). CRT caused an acute re-distribution of myocardial work, on average with most increase in the septum and most decrease laterally (all walls p<0.05) and lead to a homogeneous work distribution (Figure 1B). The acute change in the difference between lateral and septal wall work (Δlateral − septal work) correlated best and significantly with LV ESV reverse-remodelling (r=0.62, p<0.0001). The smallest changes in work were seen in the patients with the least LV ESV reverse remodelling (Figure 1C, red markers), while patients with the most LV ESV reverse remodelling showed the largest changes in work (Figure 1C, green markers). In a multivariate-linear-regression-analysis, including pre-implant QRS duration, LVEF, LV EDV and GLS, the re-distribution of work remained as the strongest determinant of volumetric reverse-remodelling after CRT (r=0.63, p<0.0001).

Figure 1

Conclusions

The acute re-distribution of regional myocardial work between the septal and lateral wall of the left ventricle is the main determinant of long term reverse-remodelling after CRT-implantation. Our data suggest that modification of regional loading is the mode of action of CRT treatment.

P3641Matrix Metalloproteinase-2 polymorphisms are associated with prognosis of patients with symptomatic coronary artery disease

Background

Matrix Metalloproteinase-2 (MMP-2) is involved in regulation and proliferation of vascular and endothelial cells and is therefore an important component of atherosclerotic vessels. Inhibition of MMP-2 activity is associated with improvement of cardiac function in animal models after myocardial infarction. MMP-2 single nucleotide polymorphisms (SNPs) might alter MMP-2 expression and therefore influence prognosis in patients with symptomatic coronary artery disease (CAD).

Methods and results

Genotyping for selected MMP-2 SNPs variants (rs2241145, rs2285053, rs2287076, rs243865, rs7201) was performed in 943 consecutive patients with symptomatic CAD. All patients were followed-up for all-cause death (ACD), myocardial infarction (MI) and ischemic stroke (IS) for 360 days. The primary combined endpoint (CE) consisted of either first occurrence of ACD, and/or MI, and/or IS. Secondary endpoints were defined as the single events of ACD or MI. Homozygous carriers of major allele (rs2241145, rs2287076) showed significantly better event-free survival than carriers of the minor allele for CE (Log rank = 0.022 and Log rank= 0.015, respectively). Furthermore, homozygous carriers of major allele (rs2241145, rs2285053, rs2287076) showed significantly better event-free survival for ACD (Log rank= 0.047, Log rank= 0.006 and Log rank= 0.023, respectively). In multivariate analysis, MMP-2 rs2241145, rs2287076 and rs2285053 were significantly and independently associated with CE and ACD.

Figure 1

Conclusions

MMP-2 rs2241145, rs2287076 and rs2285053 are associated with prognosis and might be valuable for further risk stratification in CAD patients.

Acknowledgement/Funding

DFG, KFO 274, CRC TR 240

P3643Junctional Adhesion Molecule-A (JAM-A) polymorphisms influence serum levels of soluble JAM-A and are associated with long term prognosis in coronary artery disease

Aims

Junctional adhesion molecule A (JAM-A/F11R) is a cell adhesion molecule. Membrane associated JAM-A mediates platelet aggregation, secretion, adhesion, and spreading. Plasma levels of JAM-A are elevated in hypertension and atherosclerosis. This study was designed to investigate the impact of JAM-A single nucleotide polymorphisms (SNPs) on circulatory JAM-A levels and prognosis in patients with symptomatic coronary artery disease (CAD).

Methods and results

JAM-A SNP analysis (JAM-A F11R rs2774276 and rs790056) was performed in 943 patients with symptomatic CAD. All patients were tracked for all-cause death (ACD), myocardial infarction (MI), and ischemic stroke (IS) for 1080 days. The primary combined endpoint (CE) was defined as a composite of ACD and/or MI and/or IS. Secondary endpoints were defined as the single events of ACD and MI. Homozygote carriers of the minor allele (F11R rs2774276 and rs790056) showed significantly worse event-free survival for MI when compared with major allele carriers (Log rank = 0.011 and log rank = 0.031, respectively). No significant differences could be shown for the CE and ACD. Of note, in multivariate analysis, both SNPs were significantly and independently associated with MI. Furthermore, serum levels of soluble JAM-A were elevated in homozygote carriers of minor allele when compared to major allele carriers. Finally, serum levels of soluble JAM-A were significantly elevated in patients with MI when compared to stable CAD (p=0.036).

Figure 1

Conclusion

JAM-A SNPs are associated with prognosis in patients with symptomatic coronary artery disease. Furthermore, JAM-A SNPs might influence serum concentration of soluble JAM-A. Finally, serum concentration of soluble JAM-A is higher in patients with myocardial infarction when compared to stable coronary artery disease. These findings suggest JAM-A as a valuable biomarker for risk stratification and tailoring therapies in patients with coronary artery disease.

Acknowledgement/Funding

DFG-KFO274, CRC/Transregio 240

Development and validation of a novel prognostic score to predict survival in patients with metastatic colorectal cancer: the metastatic colorectal cancer score (mCCS)

AIM

Published prognostic scores for metastatic colorectal cancer (mCRC) are based on data from highly selected patient subgroups with specified first-line treatments and may not be applicable to routine practice. We have therefore developed and validated the metastatic colorectal cancer score (mCCS) to predict overall survival (OS) for patients with mCRC.

METHOD

A total of 1704 patients from the prospective, multicentre cohort study Tumour Registry Colorectal Cancer were separated into learning (n = 796) and validation (n = 908) samples. Using a multivariate Cox regression model, the six-factor mCCS was established.

RESULTS

The six independent prognostic factors for survival are as follows: two or more metastatic sites at the start of first-line treatment, tumour grading ≥ G3 at primary diagnosis, residual tumour classification ≥ R1/unknown, lymph node ratio (of primary tumour) ≥ 0.4, tumour stage ≥ III/unknown at primary diagnosis and KRAS status mutated/unknown. The mCCS clearly separated the learning sample into three risk groups: zero to two factors (low risk), three factors (intermediate risk) and four to six factors (high risk). The prognostic performance of the mCCS was confirmed in the validation sample and additionally stratified a large sample of patients with known (K)RAS mutation status.

CONCLUSION

The novel prognostic score, mCCS, clearly defines three prognostic groups for OS at start of first-line therapy. For oncologists, the mCCS represents a simple and easy-to-apply tool for routine clinical use, as it is based on objective tumour characteristics and can assist with treatment decision-making and communication of the prognosis to patients.

Neuroimaging of Brain Tumors: Pseudoprogression, Pseudoresponse, and Delayed Effects of Chemotherapy and Radiation

Management of patients with brain cancer critically depends on an accurate interpretation of imaging findings that will guide treatment decisions. Treatment with chemotherapy and radiation can affect the imaging characteristics of a tumor and therefore cause misinterpretation of treatment response. Specifically, radiotherapy or chemotherapy may result in distinctive imaging abnormalities that can be challenging to differentiate from tumor itself. Moreover, cancer therapy can be associated with unique adverse effects on the brain, which need to be appropriately recognized by the treating physician to guide patient management. Specific imaging findings, such as radiation-induced tissue necrosis, leukoencephalopathy, pseudoprogression, and pseudoresponse represent treatment-related phenomena that can complicate interpretation of imaging studies and clinical decision making. The aim of this review is to describe these phenomena and improve clinician familiarity as to how these appear on structural (MRI) and functional (perfusion, spectroscopy, PET) imaging studies.

Sodium phosphate enemas do not worsen renal function among hospitalized patients with mild to moderate renal failure: a matched, case-control study

BACKGROUND

Sodium phosphate enemas (SPEs) are widely used among hospitalized patients despite their potential to worsen renal failure.

AIM

We decided to assess the extent to which this side effect is clinically relevant.

DESIGN

We conducted a matched case-control, retrospective study in a cohort of hospitalized patients.

METHODS

Patients treated and untreated with SPEs were matched for age, gender, baseline creatinine, usage of certain medications and several background diagnoses. Three groups of matched patients (whole study cohort, patients with baseline creatinine > 1.5 mg/dl and those with baseline creatinine > 2 mg/dl) were compared with regards to their creatinine and blood electrolyte concentrations during 3 consecutive hospitalization days after SPE application.

RESULTS

Four hundred and twelve patients were included in this study of which 206 were treated by single SPEs. Exact matching was done for the whole study cohort, for 108 patients with baseline creatinine > 1.5 mg/dl and for 58 patients with baseline creatinine > 2 mg/dl. During 3 consecutive days after SPEs, the maximal blood concentrations of creatinine, phosphor and potassium did not differ significantly between treated patients and matched controls, in all three patients' groups.

CONCLUSION

Application of SPEs neither seem to worsen mild to moderate renal failure, nor are associated with hyperphosphatemia or hyperkalemia in patients hospitalized in internal medicine departments.

Osteocondromatose em gato: relato de caso

RESUMO A osteocondromatose é caracterizada por nódulos únicos ou múltiplos decorrentes de um crescimento ósseo excessivo benigno. É encontrada em cães, gatos, equinos e humanos. Em felinos, tem maior incidência dos dois aos quatro anos de idade. A etiologia em gatos está relacionada ao vírus da leucemia felina, e também já foi encontrada relação com o fibrossarcoma. A manifestação clínica depende do local acometido e do tamanho da lesão. O diagnóstico definitivo é por meio de histopatologia e o prognóstico é desfavorável, pois ocorrem muitas recidivas. Este relato de caso objetiva descrever a apresentação dessa enfermidade em um felino jovem.

Failure of non-vacuum steam sterilization processes for dental handpieces

BACKGROUND

Dental handpieces are used in critical and semi-critical operative interventions. Although some dental professional bodies recommend that dental handpieces are sterilized between patient use there is a lack of clarity and understanding of the effectiveness of different steam sterilization processes. The internal mechanisms of dental handpieces contain narrow lumens (0.8-2.3 mm) which can impede the removal of air and ingress of saturated steam required to achieve sterilization conditions.

AIM

To identify the extent of sterilization failure in dental handpieces using a non-vacuum process.

METHODS

In-vitro and in-vivo investigations were conducted on widely used UK bench-top steam sterilizers and three different types of dental handpieces. The sterilization process was monitored inside the lumens of dental handpieces using thermometric (TM; dataloggers), chemical indicator (CI), and biological indicator (BI) methods.

FINDINGS

All three methods of assessing achievement of sterility within dental handpieces that had been exposed to non-vacuum sterilization conditions demonstrated a significant number of failures [CI: 8/3024 (fails/no. of tests); BI: 15/3024; TM: 56/56] compared to vacuum sterilization conditions (CI: 2/1944; BI: 0/1944; TM: 0/36). The dental handpiece most likely to fail sterilization in the non-vacuum process was the surgical handpiece. Non-vacuum sterilizers located in general dental practice had a higher rate of sterilization failure (CI: 25/1620; BI: 32/1620; TM: 56/56) with no failures in vacuum process.

CONCLUSION

Non-vacuum downward/gravity displacement, type N steam sterilizers are an unreliable method for sterilization of dental handpieces in general dental practice. The handpiece most likely to fail sterilization is the type most frequently used for surgical interventions.

Saliva testing for human papilloma virus in oropharyngeal squamous cell carcinoma: A diagnostic accuracy study

BACKGROUND

New cases of oropharyngeal squamous cell carcinoma (OPSCC) are routinely tested for HPV. HPV in saliva can be detected with PCR, but its clinical applicability in the context of OPSCC remains unknown.

METHODS

Forty-six consecutive patients diagnosed with OPSCC had pre-treatment saliva specimens collected. PCR for HPV on saliva was compared to p16 IHC and HPV DNA in situ hybridisation (ISH) on surgical biopsies.

RESULTS

The sensitivity and specificity of saliva testing when compared to the reference test of p16 IHC and HPV DNA ISH were 72.2% and 90%, and positive and negative predictive values were 96.3% and 47.4%. There were no adverse events. Time from last meal, smoking, alcohol drinking and physical exercise did not impact on results.

CONCLUSIONS

Saliva testing is a promising test to detect HPV in patients with OPSCC. A positive result could avoid the need for surgical biopsies, thereby reducing costs, patient morbidity and expedite treatment.

Polymorphic variation in TPMT is the principal determinant of TPMT phenotype: A meta-analysis of three genome-wide association studies

Thiopurine-related hematotoxicity in pediatric acute lymphoblastic leukemia (ALL) and inflammatory bowel diseases has been linked to genetically defined variability in thiopurine S-methyltransferase (TPMT) activity. While gene testing of TPMT is being clinically implemented, it is unclear if additional genetic variation influences TPMT activity with consequences for thiopurine-related toxicity. To examine this possibility, we performed a genome-wide association study (GWAS) of red blood cell TPMT activity in 844 Estonian individuals and 245 pediatric ALL cases. Additionally, we correlated genome-wide genotypes to human hepatic TPMT activity in 123 samples. Only genetic variants mapping to chromosome 6, including the TPMT gene region, were significantly associated with TPMT activity (P < 5.0 × 10^-8 ) in each of the three GWAS and a joint meta-analysis of 1,212 cases (top hit P = 1.2 × 10^-72 ). This finding is consistent with TPMT genotype being the primary determinant of TPMT activity, reinforcing the rationale for genetic testing of TPMT alleles in routine clinical practice to individualize mercaptopurine dosage.