Effect of Low-Level Tragus Stimulation on Cardiac Metabolism in Heart Failure with Preserved Ejection Fraction: A Transcriptomics-Based Analysis

Abnormal cardiac metabolism precedes and contributes to structural changes in heart failure. Low-level tragus stimulation (LLTS) can attenuate structural remodeling in heart failure with preserved ejection fraction (HFpEF). The role of LLTS on cardiac metabolism is not known. Dahl salt-sensitive rats of 7 weeks of age were randomized into three groups: low salt (0.3% NaCl) diet (control group; n = 6), high salt diet (8% NaCl) with either LLTS (active group; n = 8), or sham stimulation (sham group; n = 5). Both active and sham groups received the high salt diet for 10 weeks with active LLTS or sham stimulation (20 Hz, 2 mA, 0.2 ms) for 30 min daily for the last 4 weeks. At the endpoint, left ventricular tissue was used for RNA sequencing and transcriptomic analysis. The Ingenuity Pathway Analysis tool (IPA) was used to identify canonical metabolic pathways and upstream regulators. Principal component analysis demonstrated overlapping expression of important metabolic genes between the LLTS, and control groups compared to the sham group. Canonical metabolic pathway analysis showed downregulation of the oxidative phosphorylation (Z-score: -4.707, control vs. sham) in HFpEF and LLTS improved the oxidative phosphorylation (Z-score = -2.309, active vs. sham). HFpEF was associated with the abnormalities of metabolic upstream regulators, including PPARGC1α, insulin receptor signaling, PPARα, PPARδ, PPARGC1β, the fatty acid transporter SLC27A2, and lysine-specific demethylase 5A (KDM5A). LLTS attenuated abnormal insulin receptor and KDM5A signaling. HFpEF is associated with abnormal cardiac metabolism. LLTS, by modulating the functioning of crucial upstream regulators, improves cardiac metabolism and mitochondrial oxidative phosphorylation.

Noninvasive Vagus Nerve Stimulation in Postural Tachycardia Syndrome: A Randomized Clinical Trial

BACKGROUND

Low-level transcutaneous stimulation of the auricular branch of the vagus nerve at the tragus is antiarrhythmic and anti-inflammatory in animals and humans. Preliminary studies show that transcutaneous vagus nerve stimulation (tVNS) is beneficial in animal models of postural tachycardia syndrome (POTS).

OBJECTIVES

In this study the authors conducted a sham-controlled, double-blind, randomized clinical trial to examine the effect of tVNS on POTS over a 2-month period relative to sham stimulation.

METHODS

tVNS (20 Hz, 1 mA below discomfort threshold) was delivered using an ear clip attached to either the tragus (active; n = 12) or the ear lobe (sham; n = 14) for 1 hour daily over a 2-month period. Postural tachycardia was assessed during the baseline and 2-month visit. Heart rate variability based on 5-minute electrocardiogram, serum cytokines, and antiautonomic autoantibodies were measured at the respective time points.

RESULTS

Mean age was 34 ± 11 years (100% female; 81% Caucasian). Adherence to daily stimulation was 83% in the active arm and 86% in the sham arm (P > 0.05). Postural tachycardia was significantly less in the active arm compared with the sham arm at 2 months (mean postural increase in heart rate 17.6 ± 9.9 beats/min vs 31.7 ± 14.4 beats/min; P = 0.01). Antiadrenergic autoantibodies and inflammatory cytokines were lower in the active arm compared with the sham arm at 2 months (P < 0.05). Heart rate variability was better in the active arm. No device-related side effects were observed.

CONCLUSIONS

Our results support the emerging paradigm of noninvasive neuromodulation to treat POTS. Mechanistically, this effect appears to be related to reduction of antiautonomic autoantibodies and inflammatory cytokines, and improvement in autonomic tone. Further studies are warranted. (Autoimmune Basis for Postural Tachycardia Syndrome; NCT05043051).

Non-invasive Vagus Nerve Simulation in Postural Orthostatic Tachycardia Syndrome

Postural orthostatic tachycardia syndrome (POTS) is a chronic debilitating condition of orthostatic intolerance, predominantly affecting young females. Other than postural tachycardia, symptoms of POTS include a spectrum of non-cardiac, systemic and neuropsychiatric features. Despite the availability of widespread pharmacological and non-pharmacological therapeutic options, the management of POTS remains challenging. Exaggerated parasympathetic withdrawal and sympathetic overdrive during postural stress are principal mechanisms of postural tachycardia in POTS. Non-invasive, transcutaneous, vagus nerve stimulation (tVNS) is known to restore sympathovagal balance and is emerging as a novel therapeutic strategy in cardiovascular conditions including arrhythmias and heart failure. Furthermore, tVNS also exerts immunomodulatory and anti-inflammatory effects. This review explores the effects of tVNS on the pathophysiology of POTS and its potential as an alternative non-pharmacological option in this condition.

The Blunt Liver and Spleen Trauma (BLAST) audit: national survey and prospective audit of children with blunt liver and spleen trauma in major trauma centres

PURPOSE

To compare the reported and observed management of UK children with blunt liver or spleen injury (BLSI) to the American Pediatric Surgical Association (APSA) 2019 BLSI guidance.

METHODS

UK Paediatric Major Trauma Centres (pMTCs) undertook 1 year of prospective data collection on children admitted to or discussed with those centres with BLSI and an online questionnaire was distributed to all consultants who care for children with BLSI in those centres.

RESULTS

All 21/21 (100%) pMTCs participated; 131 patients were included and 100/152 (65%) consultants responded to the survey. ICU care was reported and observed to be primarily determined using haemodynamic status or concomitant injuries rather than injury grade, in accordance with APSA guidance. Bed rest was reported to be determined by grade of injury by 63% of survey respondents and observed in a similar proportion of patients. Contrary to APSA guidance, follow-up radiological assessment of the injured spleen or liver was undertaken in 44% of patients before discharge and 32% after discharge, the majority of whom were asymptomatic.

CONCLUSIONS

UK management of BLSI differs from many aspects of APSA guidance. A shift towards using clinical features to determine ICU admission and readiness for discharge is demonstrated, in line with a strong evidence base. However, routine bed rest and re-imaging after BLSI is common, contrary to APSA guidance. This disparity may exist due to concern that evidence around the incidence, presentation and natural history of complications after conservatively managed BLSI, particularly bleeding from pseudoaneurysms, is weak.

Reliability and validity testing of the ASSIST functional performance index

Reliability and validity testing of the ASSIST Functional Performance Index (AFPI) was conducted, focusing on persons with physical disabilities (PwPD). The AFPI was iteratively developed to assess persons' needs for Mainstream Smart Home Technologies (MSHT) as Assistive Technology (AT) and to measure the impact of a service delivery model for MSHT. The AFPI consists of 46 items organized by functional domains. A total of N = 22 PwPD completed the AFPI twice. The median response time between these two time points was four days. Test-retest reliability of overall scores was assessed using the Intraclass Correlation Coefficient model (ICC, 3.1). The weighted kappa coefficient was applied to conduct an item analysis, demonstrating moderate to substantial agreement in all but one of the items. During the second administration, validity was established by correlating the number of hours of assistance and total AFPI scores with the SCI-FI Self-Care and Basic Mobility Short Form Questionnaires. Results indicate that the AFPI demonstrates good to very good validity as an assessment tool and outcome measure in recommending and evaluating the impact of MSHT for PwPD. Future studies, including more participants and persons with cognitive and sensory disabilities, may further establish the clinical utility of the AFPI.

Transcutaneous Vagus Nerve Stimulation Ameliorates the Phenotype of Heart Failure With Preserved Ejection Fraction Through Its Anti-Inflammatory Effects

BACKGROUND

A systemic proinflammatory state plays a central role in the development of heart failure with preserved ejection fraction (HFpEF). Low-level transcutaneous vagus nerve stimulation (LLTS) suppresses inflammation in animals and humans, mediated by an α7nAchR (alpha7 nicotinic acetylcholine receptor)-dependent pathway. We examined the effects of LLTS on cardiac function, inflammation, and fibrosis in the presence of α7nAchR pharmacological blockade in a rat model of HFpEF.

METHODS

Dahl salt-sensitive rats at 7 weeks of age were treated with high-salt diet for 6 weeks to induce HFpEF, followed by 4 weeks of (1) LLTS, (2) LLTS with the α7nAchR blocker methyllycaconitine, (3) sham, and (4) olmesartan. Blood pressure, cardiac function by echocardiography, heart rate variability, and serum cytokines were measured at 13 and 17 weeks of age. Cardiac fibrosis, inflammatory cell infiltration, and gene expression were determined at 17 weeks.

RESULTS

LLTS attenuated the increase in blood pressure; improved cardiac function; decreased inflammatory cytokines, macrophage infiltration, and fibrosis; and improved survival compared with other groups. Methyllycaconitine attenuated these effects, whereas olmesartan did not improve cardiac function or fibrosis despite maintaining similar blood pressure as LLTS. Heart rate variability was similarly improved in the LLTS and LLTS plus methyllycaconitine groups but remained low in the other groups. LLTS reversed the dysregulated inflammatory signaling pathways in HFpEF hearts.

CONCLUSIONS

Neuromodulation with LLTS improved cardiac function in a rat model of HFpEF through its anti-inflammatory and antifibrotic effects. These results provide the basis for further clinical trials in humans.

Direct Measurement of Carbon Fusion at Astrophysical Energies with Gamma-Particle Coincidences

We present 12C+12C direct fusion measurements with STELLA UKFATIMA, that reach into the region of astrophysics interest relevant to massive stars (M⊙ ≈ 25) using self-supporting thin rotating carbon foils [1]. We demonstrate that detecting gammas and light charged particles in coincidence with nanosecond timing is key for effective background reduction achieving reliable measurements in the sub-nanobarn range. We give details about core developments of the detection apparatus as well as the coincidence-analysis procedure of low count statistics. The present data largely follows the phenomenological hindrance interpolation and shows indication for resonant behaviour at the lowest energy explored.

Neuromodulation of Inflammation to Treat Heart Failure With Preserved Ejection Fraction: A Pilot Randomized Clinical Trial

Background

A systemic proinflammatory state plays a central role in the development of heart failure with preserved ejection fraction. Low‐level transcutaneous vagus nerve stimulation suppresses inflammation in humans. We conducted a sham‐controlled, double‐blind, randomized clinical trial to examine the effect of chronic low‐level transcutaneous vagus nerve stimulation on cardiac function, exercise capacity, and inflammation in patients with heart failure with preserved ejection fraction.

Methods and Results

Patients with heart failure with preserved ejection fraction and at least 2 additional comorbidities (obesity, diabetes, hypertension, or age ≥65 years) were randomized to either active (tragus) or sham (earlobe) low‐level transcutaneous vagus nerve stimulation (20 Hz, 1 mA below discomfort threshold), for 1 hour daily for 3 months. Echocardiography, 6‐minute walk test, quality of life, and serum cytokines were assessed at baseline and 3 months. Fifty‐two patients (mean age 70.4±9.2 years; 70% female) were included (active, n=26; sham, n=26). Baseline characteristics were balanced between the 2 arms. Adherence to the protocol of daily stimulation was >90% in both arms (P>0.05). While the early mitral inflow Doppler velocity to the early diastolic mitral annulus velocity ratio did not differ between groups, global longitudinal strain and tumor necrosis factor‐α levels at 3 months were significantly improved in the active compared with the sham arm (−18.6%±2.5% versus −16.0%±2.4%, P=0.002; 8.9±2.8 pg/mL versus 11.3±2.9 pg/mL, P=0.007, respectively). The reduction in tumor necrosis factor‐α levels correlated with global longitudinal strain improvement (r=−0.73, P=0.001). Quality of life was better in the active arm. No device‐related side effects were observed.

Conclusions

Neuromodulation with low‐level transcutaneous vagus nerve stimulation over 3 months resulted in a significant improvement in global longitudinal strain, inflammatory cytokines, and quality of life in patients with heart failure with preserved ejection fraction.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03327649.

721 Imaging for Suspected Bowel Obstruction in Pennine Acute Trust (PAT): A Comparison with the National Audit of Small Bowel Obstruction’s (NASBO) recommendations

Background

NASBO recommends Computed Topography (CT) over plain abdominal X-ray (AXR) for the investigation of bowel obstruction (BO). AXR is routinely used within PAT for investigation of BO which may be exposing patients to unnecessary radiation and adding unnecessary cost to the service.

Method

A retrospective audit collected data on patients with CT confirmed BO between July 2019 and February 2020. This looked at the percentage of patients who had both CT and AXR to investigate BO. The cost of these AXRs and the percentage of these AXRs that were normal were also calculated.

Results

A search identified 141 patients with CT proven BO. 81/141(57.4%) patients had both AXR and CT as a part of their initial investigations. Of those patients 26/81(32.1%) had no AXR features suggestive of BO. Only 12/81(14.8%) of those patients had serial AXRs following initial imaging. The cost for one AXR is £34.15 which means £2766.15 was spent on potentially unnecessary AXRs within this period.

Conclusions

PAT is performing potentially unnecessary AXRs which is exposing patients to unnecessary radiation and costing the trust. Plain AXRs do not rule out BO. We have recommended an investigation flowchart to PAT A&E departments to reduce unnecessary AXRs being performed.

Stress is associated with larger perivascular spaces in depression: A 7-tesla MRI study

Introduction

Emerging evidence in depressive phenotypes suggests that the breakdown of the blood brain barrier (BBB) andhigh levels of inflammatory cytokines in states of persistent stress or traumatic experiences may contribute to its pathophysiology. Ultra-high field MRI may aid in the radiological detection of maladaptations of the glymphatic system related to BBB integrity that may not be visualized at lower field strengths.

Objectives

We aimed to investigate the link between glymphatic neuroanatomy in the form of perivascular spaces (PVS) and trauma experience in patients with major depressive disorder.

Methods

We examined PVS’s in patients with major depressive disorder and in healthy controls using 7-Tesla MRI and a semi-automated segmentation algorithm.

Results

After controlling for age and gender, we found that the number of traumatic life events experienced was positively correlated with total PVS volume in MDD patients (r= 0.50, p= 0.028) and the overall population (r= 0.34, p= 0.024). Furthermore, the number of traumatic events eliciting fear, helplessness, or horror was positively correlated with total PVS volume in MDD patients (r= 0.50, p= 0.030) and the overall population (r= 0.32, p= 0.023). As expected, age correlated positively with PVS count (r= 0.37, p= 0.013), PVS total volume (r= 0.53, p< 0.001), and PVS density (r= 0.68, p< 0.001 in all participants.

Conclusions

These results suggest a relationship between glymphatic dysfunction potentially related to BBB integrity and psychological trauma in patients with depression, and suggest that glymphatic impairment may play a role in trauma-related symptomatology.

Sex differences in the incidence and mode of death in rats with heart failure with preserved ejection fraction

NEW FINDINGS

What is the central question of this study? Prior studies failed to address the role of sex in modifying the pathophysiology and response to therapy in heart failure with preserved ejection fraction (HFpEF), potentially introducing bias into translational findings. We aimed to explore sex differences in outcomes and sought to identify the underlying mechanisms in a well-established rat model of HFpEF. What is the main finding and its importance? Male rats with HFpEF exhibited worse survival compared with females and were at a higher risk for sudden death, attributable in part to QT prolongation, autonomic dysregulation and enhanced inflammation. These data might provide the basis for the development of sex-specific interventions in HFpEF targeting these abnormalities.

ABSTRACT

Heart failure with preserved ejection fraction (HFpEF) accounts for 50% of heart failure, and sudden death is the leading cause of mortality. We aimed to explore sex differences in outcomes in rats with HFpEF and sought to identify the underlying mechanisms. Dahl salt-sensitive rats of either sex were randomized into high-salt diet (HS diet; 8% NaCl, n = 46, 50% female) or low-salt diet (LS diet; 0.3% NaCl; n = 24, 50% female) at 7 weeks of age. After 6 and 10 weeks of LS or HS diets, the ECG, heart rate variability, cytokines and echocardiographic parameters were measured. The animals were monitored daily for development of HFpEF and survival. Over 6 weeks of HS diet, rats developed significant hypertension and signs of HFpEF. Compared with female HS diet-fed rats, males exhibited more left ventricular dilatation, a longer QT interval, and worse autonomic tone, as assessed by heart rate variability and elevated inflammatory cytokines. Ten of 23 (46%) male rats died during follow-up, compared with two of 23 (9%) female rats (P = 0.01). There were four sudden deaths in males (with ventricular tachycardia documented in one rat), whereas the females died of heart failure. In conclusion, male rats with HFpEF exhibit worse survival compared with females and are at a higher risk for sudden death, attributable in part to QT prolongation, autonomic dysregulation and enhanced inflammation. These data might provide the basis for the development of sex-specific interventions in HFpEF targeting these abnormalities.

Non-invasive vagus nerve stimulation attenuates proinflammatory cytokines and augments antioxidant levels in the brainstem and forebrain regions of Dahl salt sensitive rats

The anti-inflammatory effects of vagus nerve stimulation are well known. It has recently been shown that low-level, transcutaneous stimulation of vagus nerve at the tragus (LLTS) reduces cardiac inflammation in a rat model of heart failure with preserved ejection fraction (HFpEF). The mechanisms by which LLTS affect the central neural circuits within the brain regions that are important for the regulation of cardiac vagal tone are not clear. Female Dahl salt-sensitive rats were initially fed with either low salt (LS) or high salt (HS) diet for a period of 6 weeks, followed by sham or active stimulation (LLTS) for 30 min daily for 4 weeks. To study the central effects of LLTS, four brainstem (SP5, NAb, NTS, and RVLM) and two forebrain sites (PVN and SFO) were examined. HS diet significantly increased the gene expression of proinflammatory cytokines in the SP5 and SFO. LLTS reversed HS diet-induced changes at both these sites. Furthermore, LLTS augmented the levels of antioxidant Nrf2 in the SP5 and SFO. Taken together, these findings suggest that LLTS has central anti-inflammatory and antioxidant properties that could mediate the neuromodulation of cardiac vagal tone in the rat model of HFpEF.

The impact of compliance on Stage 2 uni-ventricular heart circulation: An experimental assessment of the Bidirectional Glenn

The Bidirectional Glenn (BDG) or cavopulmonary connection is typically undertaken to volume unload the single ventricle in an effort to preserve ventricular and atrioventricular valve function. The geometry of this surgical palliation has been shown to influence the fluid energy loss as well as the distribution of flow that enters through the superior vena cava. In-vitro and in-silico studies to date have been performed on rigid wall models, while this investigation looks at the impact of flexible thin walled models versus rigid walls. Rigid and compliant models of two patient-specific Glenn geometries were fabricated and tested under various flow conditions, within a biosimulator capable of replicating patient specific flow conditions. It was found that the compliant models exhibit greater levels of energy loss compared to the rigid models. Along with these findings greater levels of turbulence was found in both compliant models compared to their rigid counterparts under ultrasound examinations. This shows that vessel compliance has a significant impact on the hemodynamics within hypoplastic left heart syndrome.

Palliative Radiation Therapy in Older Adults With Cancer: Age-Related Considerations

There are many additional considerations when treating older adults with cancer, especially in the context of palliative care. Currently, radiation therapy is underutilised in some countries and disease sites, but there is also evidence of unnecessary treatment in other contexts. Making rational treatment decisions for older adults necessitates an underlying appraisal of the person's physiological reserve capacity. This is termed 'frailty', and there is considerable heterogeneity in its clinical presentation, from patients who are relatively robust and suitable for standard treatment, to those who are frail and perhaps require a different approach. Frailty assessment also presents an important opportunity for intervention, when followed by Comprehensive Geriatric Assessment (CGA) in those who require it. Generally, a two-step approach, with a short initial screening, followed by CGA, is advocated in geriatric oncology guidelines. This has the potential to optimise care of the older person, and may also reverse or slow the development of frailty. It therefore has an important impact on the patient's quality of life, which is especially valued in the context of palliative care. Frailty assessment also allows a more informed discussion of treatment outcomes and a shared decision-making approach. With regards to the radiotherapy regimen itself, there are many adaptations that can better facilitate the older person, from positioning and immobilisation, to treatment prescriptions. Treatment courses should be as short as possible and take into account the older person's unique circumstances. The additional burden of travel to treatment for the patient, caregiver or family/support network should also be considered. Reducing treatments to single fractions may be appropriate, or alternatively, hypofractionated regimens. In order to enhance care and meet the demands of a rapidly ageing population, future radiation oncology professionals require education on the basic principles of geriatric medicine, as many aspects remain poorly understood.

Advances in the Direct Study of Carbon Burning in Massive Stars

The ^{12}C+^{12}C fusion reaction plays a critical role in the evolution of massive stars and also strongly impacts various explosive astrophysical scenarios. The presence of resonances in this reaction at energies around and below the Coulomb barrier makes it impossible to carry out a simple extrapolation down to the Gamow window-the energy regime relevant to carbon burning in massive stars. The ^{12}C+^{12}C system forms a unique laboratory for challenging the contemporary picture of deep sub-barrier fusion (possible sub-barrier hindrance) and its interplay with nuclear structure (sub-barrier resonances). Here, we show that direct measurements of the ^{12}C+^{12}C fusion cross section may be made into the Gamow window using an advanced particle-gamma coincidence technique. The sensitivity of this technique effectively removes ambiguities in existing measurements made with gamma ray or charged-particle detection alone. The present cross-section data span over 8 orders of magnitude and support the fusion-hindrance model at deep sub-barrier energies.

Qualitative Ampule and Multitest for Beta-Lactam Residues in Fluid Milk Products: Collaborative Study

A collaborative study was performed on a rapid Bacillus stearothermophilus agar diffusion ampule method to detect low levels of penicillin G in 7 types of fluid milk products. A multitest technique for processing a large number of samples simultaneously was also studied. Slight modifications were made in the original method to establish more uniformity and to eliminate doubtful responses by specifying a confirmation procedure. Twenty samples spiked with penicillin G (0.000 to 0.008 IU/mL) and tetracycline hydrochloride were frozen and sent to 20 laboratories in the ampule test, and 16 laboratories in the multitest. Each analyst was asked to do a screening run and a confirmation run. Results were reported by color reaction and also as positive or negative for β-lactam inhibitors. The concentrations (penicillin G) where percent positive results equal 100 or not significantly less than 100 (α = 0.05) ranged from 0.005 to 0.007 IU/mi in the ampule test and from 0.004 to 0.007 IU/mL in the multitest. Both techniques have been adopted official first action.

Pharmacokinetics and pharmacodynamics of the novel monobactam LYS228 in a neutropenic murine thigh model of infection

Objectives

The neutropenic murine thigh infection model and a dose-fractionation approach were used to determine the pharmacokinetic/pharmacodynamic (PK/PD) relationship of LYS228, a novel monobactam antibiotic with activity against Enterobacteriaceae including carbapenem-resistant strains.

Methods

Mice (n = 4 per group) were inoculated with Enterobacteriaceae strains via intramuscular injection. Two hours post-bacterial inoculation, treatment with LYS228 was initiated. Animals were euthanized with CO2 24 h after the start of therapy and bacterial counts (log10 cfu) per thigh were determined. PK parameters were calculated using free (f) plasma drug levels.

Results

Following a dose-fractionation study, non-linear regression analysis determined that the predominant PK/PD parameter associated with antibacterial efficacy of LYS228 was the percentage of the dosing interval that free drug concentrations remained above the MIC (%fT>MIC). In a dose-dependent manner, LYS228 reduced the thigh bacterial burden in models established with Enterobacteriaceae producing β-lactamase enzymes of all classes (e.g. ESBLs, NDM-1, KPC, CMY-2 and OXA-48). The range of the calculated static dose was 86-649 mg/kg/day for the isolates tested, and the magnitude of the driver of efficacy was 37-83 %fT>MIC. %fT>MIC was confirmed as the parameter predominantly driving efficacy as evidenced by a strong coefficient of determination (r2 = 0.68). Neutrophils had minimal impact on the effect of LYS228 in the murine thigh infection model.

Conclusions

LYS228 is efficacious in murine thigh infection models using β-lactamase-producing strains of Enterobacteriaceae, including those expressing metallo-β-lactamases, ESBLs and serine carbapenemases, with the PK/PD driver of efficacy identified as %T>MIC.

P3512Sex differences in rats with heart failure with preserved ejection fraction and the effect of autonomic modulation

Background

Heart failure (HF) with preserved ejection fraction (HFpEF) accounts for 50% of HF and sudden death is the leading cause of mortality. There are considerable sex differences in cardiac structure and function, which may be related to outcomes in HFpEF. Transcutaneous vagus nerve stimulation (tVNS) is antiarrhythmic.

Purpose

To describe sex differences in mortality, autonomic tone and ECG parameters in rats with HFpEF and examine the effect of tVNS on these outcomes.

Methods

Dahl salt sensitive (DS) rats of either sex were randomized into high salt (HS, 8% NaCl) or low salt (LS) diet (0.3% NaCl) at 7 weeks of age. After 6 weeks of LS or HS diets, HS rats were randomized to receive active or sham tVNS, 30min daily (20Hz, 3mA) for 4 weeks. The rats were monitored daily for 4 weeks for the development of HFpEF. ECG and echocardiogram were performed at 13 weeks (baseline) and 17 weeks (endpoint). Heart rate variability (HRV) was calculated at the respective time points. ECG and HRV parameters were analyzed in a blinded fashion. Logistic regression analysis was performed to identify independent predictors of mortality.

Results

A total of 58 rats were included (5 male LS, 6 female LS, 22 male HS and 25 female HS). HS rats developed significant hypertension and signs of HFpEF, while 24% of females and 53% of males died (P=0.004). There were 4 sudden cardiac deaths in males (with ventricular tachycardia documented in 1 rat), whereas all the females died of HF or stroke. Corrected QT (QTc) at baseline significantly prolonged in HS compared to LS rats (250.5±14.4ms vs. 226.8±13.9ms, respectively, p=0.0007), while all other ECG parameters did not differ significantly between groups. In HS rats, QTc prolongation was significantly more pronounced in males compared to females (259.4±20.6ms vs. 243.8±14.5ms, respectively, P=0.002). In univariate analysis, prolonged baseline QTc (OR=1.04; 95% CI 1.01–1.06, p=0.003) and male sex (OR=3.21, 95% CI 1.19–8.66, p=0.016) predicted mortality. However, in multivariate analysis, QTc was the only significant predictor of mortality (OR=1.04; 95% CI 1.01–1.06, p=0.003). After 4 weeks of treatment, active tVNS significantly decreased QTc compared to sham (244.6±13.8ms vs. 255.8±14.0ms, respectively, p=0.017) in both male and female rats in a similar manner. The low frequency to high frequency ratio (LF/HF) of HRV, which reflects sympathovagal balance, was significantly decreased in active tVNS rats compared to sham (0.21±0.13 vs. 0.54±0.14, respectively; p=0.001) in both male and female rats in a similar manner.

Conclusions

Male rats with HFpEF exhibit worse survival compared to females and are at higher risk for sudden death. QTc prolongation accounts for the increased risk of sudden death in males compared to females. Autonomic modulation with tVNS attenuates the unfavorable changes in QTc and HRV induced by HS diet and may be used to prevent ventricular arrhythmias in patients with HFpEF.

Successful implementation of bedaquiline for multidrug-resistant TB treatment in remote Papua New Guinea

SETTING

Bedaquiline (BDQ) was introduced in the multi-drug-resistant tuberculosis (MDR-TB) programme in Daru in remote Papua New Guinea in 2015, along with a core package of active drug-safety monitoring (aDSM).

OBJECTIVE

To assess interim results and safety of BDQ for the treatment of MDR-TB from 1 July 2015 to 31 December 2017.

DESIGN

A retrospective cohort analysis of routine programme data.

RESULTS

Of 277 MDR-TB patients, 77 (39%) received BDQ with a total of 8 serious adverse events including 5 (6.5%) deaths, of which 1 (1.3% QTcF prolongation, grade 3) was attributable to BDQ. Of 200 (61%) patients who did not receive BDQ, there were 17 (9%) deaths. Completeness of monitoring for the BDQ group was 90% for >5 electrocardiograms and 79% for ⩾2 cultures. In the interim result indicator analysis at month 6 in the BDQ and non-BDQ groups, there were respectively 0% and 1% lost to follow-up; 6.5% and 8.5% who died; 94% and 91% in care; and 92% and 96% with negative culture among those monitored.

CONCLUSION

Early experience in Daru shows BDQ is safe and feasible to implement with aDSM with good interim effectiveness supporting the rapid adoption and scale-up of the 2019 WHO MDR-TB treatment guidelines in the programme and in similar remote settings.

A pilot model of patient education and counselling for drug-resistant tuberculosis in Daru, Papua New Guinea

Education and counselling for people with drug-resistant tuberculosis (DR-TB) is recommended by the World Health Organization, given the arduous treatment journey. A model of education and counselling involving counsellors and peer counsellors, standard sessions and novel education tools was piloted in the high DR-TB burden context of Daru, Papua New Guinea. The pilot contributed to high retention in care, highlighting the need for investment in scalable models. Future models will need to be adapted as better tolerated regimens are introduced. A focus on patient-centred care requires prioritisation in order to meet the End TB Strategy targets.

The emergency response to multidrug-resistant tuberculosis in Daru, Western Province, Papua New Guinea, 2014-2017

SETTING

A response to an outbreak of multidrug-resistant tuberculosis (MDR-TB) on Daru Island, South Fly District (SFD), Western Province, Papua New Guinea (PNG) was implemented by a national emergency response taskforce.

OBJECTIVE

To describe programmatic interventions for TB in SFD and evaluate characteristics of TB case notifications, drug resistance and treatment outcomes.

DESIGN

This was a retrospective cohort study based on routine programmatic data for all patients enrolled on TB treatment at Daru General Hospital from 2014 to 2017.

RESULTS

The response involved high-level political commitment, joint planning, resource mobilisation, community engagement and strengthening TB case detection and treatment. Of 1548 people enrolled on TB treatment, 1208 (78%) had drug-susceptible TB (DS-TB) and 333 (21.5%) had MDR-TB. There was an increase in MDR-TB as a proportion of all TB. Treatment success rates increased over the study period from 55% to 86% for DS-TB, and from 70% to 81% for MDR-TB from 2014 to 2015. The 2014 case notification rate for TB in SFD was 1031/100 000, decreasing to 736/100 000 in 2017.

CONCLUSION

The outbreak was stabilised through the response from the national and provincial governments and international partners. Additional interventions are needed to decrease the TB burden in Daru.

Tuberculosis treatment unmasking leprosy: management of drug-resistant tuberculosis and leprosy co-infection

Co-infection with tuberculosis (TB) and leprosy is thought to occur infrequently, but has been reported in settings highly endemic for both infectious diseases. We report for the first time a case where treatment for multidrug-resistant TB (MDR-TB) led to the 'unmasking' of clinically silent leprosy through the precipitation of a type-1 immunological reaction. Current treatment regimens for MDR-TB may contain a number of drugs, such as levo-floxacin and clofazimine, which also have activity against M. leprae. A treatment regimen containing drugs active against both mycobacterial species may be used to achieve cure. Individual considerations on drug-drug interactions, potential additive toxicities and other comorbidities should be taken into account.

A1 The role of virus-antibody co-evolution in the development of a V3-glycan-directed HIV-1 broadly neutralizing antibody lineage

Broadly neutralizing antibodies (bNAbs) are essential for a preventative HIV-1 vaccine but have not been elicited through vaccination. bNAbs develop in 20–30 per cent of HIV-1 infections and often target the V3-glycan epitope of the HIV envelope protein (Env). In these individuals, virus-antibody co-evolution is thought to drive the maturation of antibody lineages to neutralization breadth. We used deep sequencing of env genes and antibody transcripts from fourteen time points spanning the first 3 years of infection to characterize the virus-antibody co-evolution in donor CAP255 who developed V3-glycan-specific bNAbs. Sequencing and cloning of env genes, followed by neutralization assays, were used to identify Env mutations associated with neutralization escape from two bNAbs (CAP255.G3 and CAP255.C5) isolated at 149 weeks post-infection (wpi). Sequencing data indicated that CAP255 was co-infected by three related viral variants, all of which had an intact N332 glycan, which persisted in > 90 per cent of later viruses. A recombinant V3-region became fixed from 8 wpi, conferring slight neutralization resistance to CAP255.G3/C5 and other V3-glycan bNAbs. Later, T415R/K substitutions in V4 emerged by 51 wpi and were associated with complete viral escape from CAP255.G3/C5, though not from the polyclonal plasma response. All 93-week and later Envs were resistant to CAP255.G3/C5 and V3-glycan bNAb PGT135. Viral escape by 51 wpi suggested that the CAP255 bNAbs arose earlier, driving escape, but persisted to 149 weeks. This was supported by preliminary deep sequencing of the antibody repertoire that indicated bNAb lineage members were already present in the plasma at 39 wpi. Escape from V3-glycan bNAbs via T415R/K mutations have not previously been shown, suggesting a novel mode of recognition within the V3-glycan supersite. Further work will focus on identifying the bNAb-initiating Env and intermediate bNAb lineage members that were capable of engaging contemporaneous Env neutralization escape mutants. Characterization of Envs that engaged bNAb precursors, as well as those that selected for broader members of the bNAb lineage, will inform the design of immunogens capable of eliciting V3-glycan bNAbs in a novel HIV-1 vaccine regimen.

Embolus Analog Trajectory Paths Under Physiological Flowrates Through Patient-Specific Aortic Arch Models

Atrial fibrillation (AF) is the most common irregular heartbeat among the world's population and is a major contributor to cardiogenic embolisms and acute ischemic stroke (AIS). However, the role AF flow plays in the trajectory paths of cardiogenic emboli has not been experimentally investigated. A physiological simulation system was designed to analyze the trajectory patterns of bovine embolus analogs (EAs) (n = 720) through four patient-specific models, under three flow conditions: steady flow, normal pulsatile flow, and AF pulsatile flow. It was seen that EA trajectory paths were proportional to the percentage flowrate split of 25–31% along the branching vessels. Overall, AF flow conditions increased trajectories through the left- (LCCA) and right (RCCA)-common carotid artery by 25% with respect to normal pulsatile flow. There was no statistical difference in the distribution of clot trajectories when the clot was released from the right, left, or anterior positions. Significantly, more EAs traveled through the brachiocephalic trunk (BCT) than through the LCCA or the left subclavian. Yet of the EAs that traveled through the common carotid arteries, there was a greater affiliation toward the LCCA compared to the RCCA (p < 0.05).

Abstract P5-18-12: Effectiveness of Oncotype DX DCIS scoring in a community setting

The Oncotype DX DCIS Score was developed to assist in determining a low risk for recurrence subgroup of patients who can avoid radiation therapy following breast conserving surgery. We sought to evaluate our experience using the Oncotype DX DCIS Score and to see if a greater number of patients who did not receive radiation therapy were experiencing a local recurrence than the score predicted.

Between February 23, 2011 and November 29, 2017, 145 women were diagnosed with ductal carcinoma in situ (DCIS) without an invasive component. 126 (87%) underwent breast conserving surgery. Thirty-five underwent Oncotype DX DCIS Score, of whom 26 (74%) were low risk, four were intermediate risk (11%), and five were high risk (14%).

The scores ranged from 0 (7 patients) to 100 (1 patient). Of the 26 patients with low risk scores, one chose to undergo mastectomy, three received radiation therapy, 20 chose observation without radiation therapy, and two patients were unknown because they had no further treatment or follow-up at our facility. Two of the four intermediate risk patients underwent radiation therapy and two did not. Four of the five high risk patients underwent radiation therapy, but one did not.

Twenty-two of the 35 patients who underwent Oncotype DX Score met the criteria for size (based on grade) and margins (at least 3 mm). Ten patients had margins that were less than 3 mm but met the size criteria. Two patients did not meet the size criteria but had at least 3 mm margins. One patient did not meet either the size or margin criteria. None of our 20 patients with low risk Oncotype DX DCIS Score and who met both the size and margin criteria recurred.

With the median follow-up of approximately 2-1/2 years, three of the 21 patients (14%) with low or intermediate risk scores who underwent Oncotype DX DCIS Score and did not receive radiation therapy suffered a local recurrence. The predicted average recurrence risk for these patients based on their Oncotype DX DCIS Score was 12%. Two of these patients who recurred had margins less than 3 mm, and one patient met the size and margin criteria, but had an intermediate risk score.

By comparison, five of 61 (8%) of patients who underwent breast conserving surgery and adjuvant radiation therapy had a local recurrence.

Twenty of the 23 (87%) low risk Oncotype DX DCIS Score patients did not receive radiation therapy and overall 20/35 (57%) of the patients undergoing Oncotype DX DCIS Score did not receive radiation therapy.

Although the follow-up is still relatively short, Oncotype DX DCIS Score allows a considerable number of women to avoid adjuvant radiation therapy.

Citation Format: Wheeler JA, Vaghefi H, Liu F, Owens V, Morris L, Denham F, Coody L. Effectiveness of Oncotype DX DCIS scoring in a community setting [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-18-12.

A unique schedule of palonosetron, ondansetron, and dexamethasone for the prevention of delayed nausea and vomiting in patients receiving myeloablative chemotherapy

Myeloablative chemotherapy administered prior to autologous stem cell transplantation (auto-SCT) is associated with a significant amount of chemotherapy-induced nausea and vomiting (CINV). We conducted a phase II trial to assess the safety, efficacy, and impact on quality of life when palonosetron (PAL) 0.25 mg combined with dexamethasone were given on the final or only day of myeloablative chemotherapy for auto-SCT. The primary end point of this study was the incidence of achieving a delayed CINV complete response defined as no emetic episode and no use of rescue medications during the 24-120 h period post chemotherapy. Eighty-five patients were enrolled in the study and received PAL. A delayed CINV complete response was achieved in 15% of patients. A multivariate analysis demonstrated no associated differences between age, gender, diagnosis, or regimen. By day 5 after PAL, the mean nausea severity was 0.91 ± 2.45 vs. 0.09 ± 1.58 at baseline (p = 0.012). Quality of life measurements demonstrated similar quality of life between baseline and day 3. By day 6 however, nausea alone had a statistically significant impact on quality of life. In our study, PAL controlled nausea severity and sustained quality of life, but further strategies are needed to control delayed CINV associated with the auto-SCT process.

Communication training interventions for family and professional carers of people living with dementia: a systematic review of effectiveness, acceptability and conceptual basis

OBJECTIVES

To update previous reviews and provide a more detailed overview of the effectiveness, acceptability and conceptual basis of communication training-interventions for carers of people living with dementia.

METHOD

We searched CINAHL Plus, MEDLINE and PsycINFO using a specific search and extraction protocol, and PRISMA guidelines. Two authors conducted searches and extracted studies that reported effectiveness, efficacy or acceptability data regarding a communication training-intervention for carers of people living with dementia. Risk of bias was assessed using the Cochrane Collaboration guidelines. Quality of qualitative studies was also systematically assessed.

RESULTS

Searches identified 450 studies (after de-duplication). Thirty-eight studies were identified for inclusion in the review. Twenty-two studies focused on professional carers; 16 studies focused mainly on family carers. Training-interventions were found to improve communication and knowledge. Overall training-interventions were not found to significantly improve behaviour that challenges and caregiver burden. Acceptability levels were high overall, but satisfaction ratings were found to be higher for family carers than professional carers. Although many interventions were not supported by a clear conceptual framework, person-centred care was the most common framework described.

CONCLUSION

This review indicated that training-interventions were effective in improving carer knowledge and communication skills. Effective interventions involved active participation by carers and were generally skills based (including practicing skills and discussion). However, improvements to quality of life and psychological wellbeing of carers and people living with dementia may require more targeted interventions.

Distinct genital tract HIV-specific antibody profiles associated with tenofovir gel

The impact of topical antiretrovirals for pre-exposure prophylaxis on humoral responses following HIV infection is unknown. Using a binding antibody multiplex assay, we investigated HIV-specific IgG and IgA responses to envelope glycoproteins, p24 Gag and p66, in the genital tract (GT) and plasma following HIV acquisition in women assigned to tenofovir gel (n=24) and placebo gel (n=24) in the CAPRISA 004 microbicide trial to assess if this topical antiretroviral had an impact on mucosal and systemic antibody responses. Linear mixed effect modeling and partial least squares discriminant analysis was used to identify multivariate antibody signatures associated with tenofovir use. There were significantly higher response rates to gp120 Env (P=0.03), p24 (P=0.002), and p66 (P=0.009) in plasma and GT in women assigned to tenofovir than placebo gel at multiple time points post infection. Notably, p66 IgA titers in the GT and plasma were significantly higher in the tenofovir compared with the placebo arm (P<0.05). Plasma titers for 9 of the 10 HIV-IgG specificities predicted GT levels. Taken together, these data suggest that humoral immune responses are increased in blood and GT of individuals who acquire HIV infection in the presence of tenofovir gel.