A dynamical measure of the black hole mass in a quasar 11 billion years ago

Tight relationships exist in the local Universe between the central stellar properties of galaxies and the mass of their supermassive black hole (SMBH)1-3. These suggest that galaxies and black holes co-evolve, with the main regulation mechanism being energetic feedback from accretion onto the black hole during its quasar phase4-6. A crucial question is how the relationship between black holes and galaxies evolves with time; a key epoch to examine this relationship is at the peaks of star formation and black hole growth 8-12 billion years ago (redshifts 1-3)7. Here we report a dynamical measurement of the mass of the black hole in a luminous quasar at a redshift of 2, with a look back in time of 11 billion years, by spatially resolving the broad-line region (BLR). We detect a 40-μas (0.31-pc) spatial offset between the red and blue photocentres of the Hα line that traces the velocity gradient of a rotating BLR. The flux and differential phase spectra are well reproduced by a thick, moderately inclined disk of gas clouds within the sphere of influence of a central black hole with a mass of 3.2 × 108 solar masses. Molecular gas data reveal a dynamical mass for the host galaxy of 6 × 1011 solar masses, which indicates an undermassive black hole accreting at a super-Eddington rate. This suggests a host galaxy that grew faster than the SMBH, indicating a delay between galaxy and black hole formation for some systems.

The effects of short-term, progressive exercise training on disease activity in smouldering multiple myeloma and monoclonal gammopathy of undetermined significance: a single-arm pilot study

BACKGROUND

High levels of physical activity are associated with reduced risk of the blood cancer multiple myeloma (MM). MM is preceded by the asymptomatic stages of monoclonal gammopathy of undetermined significance (MGUS) and smouldering multiple myeloma (SMM) which are clinically managed by watchful waiting. A case study (N = 1) of a former elite athlete aged 44 years previously indicated that a multi-modal exercise programme reversed SMM disease activity. To build from this prior case study, the present pilot study firstly examined if short-term exercise training was feasible and safe for a group of MGUS and SMM patients, and secondly investigated the effects on MGUS/SMM disease activity.

METHODS

In this single-arm pilot study, N = 20 participants diagnosed with MGUS or SMM were allocated to receive a 16-week progressive exercise programme. Primary outcome measures were feasibility and safety. Secondary outcomes were pre- to post-exercise training changes to blood biomarkers of MGUS and SMM disease activity- monoclonal (M)-protein and free light chains (FLC)- plus cardiorespiratory and functional fitness, body composition, quality of life, blood immunophenotype, and blood biomarkers of inflammation.

RESULTS

Fifteen (3 MGUS and 12 SMM) participants completed the exercise programme. Adherence was 91 ± 11%. Compliance was 75 ± 25% overall, with a notable decline in compliance at intensities > 70% V̇O2PEAK. There were no serious adverse events. There were no changes to M-protein (0.0 ± 1.0 g/L, P =.903), involved FLC (+ 1.8 ± 16.8 mg/L, P =.839), or FLC difference (+ 0.2 ± 15.6 mg/L, P =.946) from pre- to post-exercise training. There were pre- to post-exercise training improvements to diastolic blood pressure (- 3 ± 5 mmHg, P =.033), sit-to-stand test performance (+ 5 ± 5 repetitions, P =.002), and energy/fatigue scores (+ 10 ± 15%, P =.026). Other secondary outcomes were unchanged.

CONCLUSIONS

A 16-week progressive exercise programme was feasible and safe, but did not reverse MGUS/SMM disease activity, contrasting a prior case study showing that five years of exercise training reversed SMM in a 44-year-old former athlete. Longer exercise interventions should be explored in a group of MGUS/SMM patients, with measurements of disease biomarkers, along with rates of disease progression (i.e., MGUS/SMM to MM).

REGISTRATION

https://www.isrctn.com/ISRCTN65527208 (14/05/2018).

Coulomb Blockade in a Nonthermalized Quantum Dot

We investigate nonequilibrium transport properties of a quantum dot in the Coulomb blockade regime under the condition of negligible inelastic scattering during the dwelling time of the electrons in the dot. Using the quantum kinetic equation we show that the absence of thermalization leads to a double step in the distribution function of electrons on the dot, provided that it is symmetrically coupled to the leads. This drastically changes nonlinear transport through the dot resulting in an additional (compared to the thermalized case) jump in the conductance at voltages close to the charging energy, which could serve as an experimental manifestation of the absence of thermalization.

Head injury in older adults presenting to the ambulance service: who do we convey to the emergency department, and what clinical variables are associated with an intracranial bleed? A retrospective case-control study

OBJECTIVE

Most older adults with traumatic brain injuries (TBI) reach the emergency department via the ambulance service. Older adults, often with mild TBI symptoms, risk being under-triaged and facing poor outcomes. This study aimed to identify whether sufficient information is available on the scene to an ambulance clinician to identify an older adult at risk of an intracranial haemorrhage following a head injury.

METHODS

This was a retrospective case-control observational study involving one regional ambulance service in the UK and eight emergency departments. 3545 patients aged 60 years and over presented to one regional ambulance service with a head injury between the 1st of January 2020 and the 31st of December 2020. The primary outcome was an acute intracranial haemorrhage on head computed tomography (CT) scan in patients conveyed to the emergency department (ED). A secondary outcome was factors associated with conveyance to the ED by the ambulance clinician.

RESULTS

In 2020, 2111 patients were conveyed to the ED and 162 patients were found to have an intracranial haemorrhage on their head CT scan. Falls from more than 2 m (adjusted odds ratio (aOR) 3.45, 95% CI 1.78-6.40), chronic kidney disease (CKD) (aOR 2.80, 95% CI 1.25-5.75) and Clopidogrel (aOR 1.98, 95% CI 1.04-3.59) were associated with an intracranial haemorrhage. Conveyance to the ED was associated with patients taking anticoagulant and antiplatelet medication or a visible head injury or head injury symptoms.

CONCLUSION

This study highlights that while most older adults with a head injury are conveyed to the ED, only a minority will have an intracranial haemorrhage following their head injury. While mechanisms of injury such as falls from more than 2 m remain a predictor, this work highlights that Clopidogrel and CKD are also associated with an increased odds of tICH in older adults following a head injury. These findings may warrant a review of current ambulance head injury guidelines.

Ultrasound compared with projection radiography for the detection of soft tissue foreign bodies - A technical note

INTRODUCTION

Soft tissue foreign bodies (STFBs) present a diagnostic challenge depending on their composition. Untreated complications can arise, namely infection through to loss of function. General (projection) radiography is recommended as the first line imaging examination. However, some STFBs are radiolucent, leading to false negative radiographs. The aim of this in vitro study was to compare ultrasound with projection radiographs for the detection of a range of different types of STFB.

METHOD

Ethical approval (for use of participants to evaluate images) was granted by the Higher Education Institute's departmental Ethics Committee. Seven hand phantoms were created from a water, gelatine and psyllium mix. A different STFB (radiolucent and radiopaque) was inserted into six phantoms, with the seventh being a control. Ultrasound and projection radiograph images were generated of each phantom. Participants (academics and radiography students) reviewed all images.

RESULTS

50 responses were received from a study population of approximately 400, (10 academics, 40 students). The ability of ultrasound to detect radiolucent foreign bodies performs well compared with projection radiography: sensitivity 94% versus 9%, specificity 90% versus 88%. For radiopaque foreign bodies the data was more mixed: sensitivity 96% versus 99%, specificity 90% versus 88%.

DISCUSSION

These data suggest that ultrasound is superior to projection radiography for the detection of radiolucent STFBs. Limitations include the lack of formal postgraduate ultrasound training within the study population and a lack of simulated bony structure within the hand phantoms.

IMPLICATIONS FOR PRACTICE

Ultrasound has the potential to be a useful modality in the detection of STFBs, particularly radiolucent objects. There are associated challenges such as conducting ultrasound in the vicinity of a wound, but further exploration of this application of ultrasound is warranted.

Improved Diagnostic Criteria for Apical Hypertrophic Cardiomyopathy

BACKGROUND

There is no acceptable maximum wall thickness (MWT) threshold for diagnosing apical hypertrophic cardiomyopathy (ApHCM), with guidelines referring to ≥15 mm MWT for all hypertrophic cardiomyopathy subtypes. A normal myocardium naturally tapers apically; a fixed diagnostic threshold fails to account for this. Using cardiac magnetic resonance, "relative" ApHCM has been described with typical electrocardiographic features, loss of apical tapering, and cavity obliteration but also with MWT <15 mm.

OBJECTIVES

The authors aimed to define normal apical wall thickness thresholds in healthy subjects and use these to accurately identify ApHCM.

METHODS

The following healthy subjects were recruited: healthy UK Biobank imaging substudy subjects (n = 4,112) and an independent healthy volunteer group (n = 489). A clinically defined disease population of 104 ApHCM subjects was enrolled, with 72 overt (MWT ≥15 mm) and 32 relative (MWT <15 mm but typical electrocardiographic/imaging findings) ApHCM subjects. Cardiac magnetic resonance-derived MWT was measured in 16 segments using a published clinically validated machine learning algorithm. Segmental normal reference ranges were created and indexed (for age, sex, and body surface area), and diagnostic performance was assessed.

RESULTS

In healthy cohorts, there was no clinically significant age-related difference for apical wall thickness. There were sex-related differences, but these were not clinically significant after indexing to body surface area. Therefore, segmental reference ranges for apical hypertrophy required indexing to body surface area only (not age or sex). The upper limit of normal (the largest of the 4 apical segments measured) corresponded to a maximum apical MWT in healthy subjects of 5.2 to 5.6 mm/m2 with an accuracy of 0.94 (the unindexed equivalent being 11 mm). This threshold was categorized as abnormal in 99% (71/72) of overt ApHCM patients, 78% (25/32) of relative ApHCM patients, 3% (122/4,112) of UK Biobank subjects, and 3% (13/489) of healthy volunteers.

CONCLUSIONS

Per-segment indexed apical wall thickness thresholds are highly accurate for detecting apical hypertrophy, providing confidence to the reader to diagnose ApHCM in those not reaching current internationally recognized criteria.

Coulomb staircase in an asymmetrically coupled quantum dot

We investigate the Coulomb blockade in quantum dots asymmetrically coupled to the leads for an arbitrary voltage bias focusing on the regime where electrons do not thermalise during their dwell time in the dot. By solving the quantum kinetic equation, we show that the current-voltage characteristics are crucially dependent on the ratio of the Fermi energy to charging energy on the dot. In the standard regime when the Fermi energy is large, there is a Coulomb staircase which is practically the same as in the thermalised regime. In the opposite case of the large charging energy, we identify a new regime in which only one step is left in the staircase, and we anticipate experimental confirmation of this finding.

Apical Ischemia Is a Universal Feature of Apical Hypertrophic Cardiomyopathy

BACKGROUND

Apical hypertrophic cardiomyopathy (ApHCM) accounts for ≈10% of hypertrophic cardiomyopathy cases and is characterized by apical hypertrophy, apical cavity obliteration, and tall ECG R waves with ischemic-looking deep T-wave inversion. These may be present even with <15 mm apical hypertrophy (relative ApHCM). Microvascular dysfunction is well described in hypertrophic cardiomyopathy. We hypothesized that apical perfusion defects would be common in ApHCM.

METHODS

A 2-center study using cardiovascular magnetic resonance short- and long-axis quantitative adenosine vasodilator stress perfusion mapping. One hundred patients with ApHCM (68 overt hypertrophy [≥15 mm] and 32 relative ApHCM) were compared with 50 patients with asymmetrical septal hypertrophy hypertrophic cardiomyopathy and 40 healthy volunteer controls. Perfusion was assessed visually and quantitatively as myocardial blood flow and myocardial perfusion reserve.

RESULTS

Apical perfusion defects were present in all overt ApHCM patients (100%), all relative ApHCM patients (100%), 36% of asymmetrical septal hypertrophy hypertrophic cardiomyopathy, and 0% of healthy volunteers (P<0.001). In 10% of patients with ApHCM, perfusion defects were sufficiently apical that conventional short-axis views missed them. In 29%, stress myocardial blood flow fell below rest values. Stress myocardial blood flow was most impaired subendocardially, with greater hypertrophy or scar, and with apical aneurysms. Impaired apical myocardial blood flow was most strongly predicted by thicker apical segments (β-coefficient, -0.031 mL/g per min [CI, -0.06 to -0.01]; P=0.013), higher ejection fraction (-0.025 mL/g per min [CI, -0.04 to -0.01]; P<0.005), and ECG maximum R-wave height (-0.023 mL/g per min [CI, -0.04 to -0.01]; P<0.005).

CONCLUSIONS

Apical perfusion defects are universally present in ApHCM at all stages. Its ubiquitous presence along with characteristic ECG suggests ischemia may play a disease-defining role in ApHCM.

An accurate and time-efficient deep learning-based system for automated segmentation and reporting of cardiac magnetic resonance-detected ischemic scar

BACKGROUND AND OBJECTIVES

Myocardial infarction scar (MIS) assessment by cardiac magnetic resonance provides prognostic information and guides patients' clinical management. However, MIS segmentation is time-consuming and not performed routinely. This study presents a deep-learning-based computational workflow for the segmentation of left ventricular (LV) MIS, for the first time performed on state-of-the-art dark-blood late gadolinium enhancement (DB-LGE) images, and the computation of MIS transmurality and extent.

METHODS

DB-LGE short-axis images of consecutive patients with myocardial infarction were acquired at 1.5T in two centres between Jan 1, 2019, and June 1, 2021. Two convolutional neural network (CNN) models based on the U-Net architecture were trained to sequentially segment the LV and MIS, by processing an incoming series of DB-LGE images. A 5-fold cross-validation was performed to assess the performance of the models. Model outputs were compared respectively with manual (LV endo- and epicardial border) and semi-automated (MIS, 4-Standard Deviation technique) ground truth to assess the accuracy of the segmentation. An automated post-processing and reporting tool was developed, computing MIS extent (expressed as relative infarcted mass) and transmurality.

RESULTS

The dataset included 1355 DB-LGE short-axis images from 144 patients (MIS in 942 images). High performance (> 0.85) as measured by the Intersection over Union metric was obtained for both the LV and MIS segmentations on the training sets. The performance for both LV and MIS segmentations was 0.83 on the test sets. Compared to the 4-Standard Deviation segmentation technique, our system was five times quicker (<1 min versus 7 ± 3 min), and required minimal user interaction.

CONCLUSIONS

Our solution successfully addresses different issues related to automatic MIS segmentation, including accuracy, time-effectiveness, and the automatic generation of a clinical report.

Safety and efficacy of tenecteplase in patients with wake-up stroke assessed by non-contrast CT (TWIST): a multicentre, open-label, randomised controlled trial

BACKGROUND

Current evidence supports the use of intravenous thrombolysis with alteplase in patients with wake-up stroke selected with MRI or perfusion imaging and is recommended in clinical guidelines. However, access to advanced imaging techniques is often scarce. We aimed to determine whether thrombolytic treatment with intravenous tenecteplase given within 4·5 h of awakening improves functional outcome in patients with ischaemic wake-up stroke selected using non-contrast CT.

METHODS

TWIST was an investigator-initiated, multicentre, open-label, randomised controlled trial with blinded endpoint assessment, conducted at 77 hospitals in ten countries. We included patients aged 18 years or older with acute ischaemic stroke symptoms upon awakening, limb weakness, a National Institutes of Health Stroke Scale (NIHSS) score of 3 or higher or aphasia, a non-contrast CT examination of the head, and the ability to receive tenecteplase within 4·5 h of awakening. Patients were randomly assigned (1:1) to either a single intravenous bolus of tenecteplase 0·25 mg per kg of bodyweight (maximum 25 mg) or control (no thrombolysis) using a central, web-based, computer-generated randomisation schedule. Trained research personnel, who conducted telephone interviews at 90 days (follow-up), were masked to treatment allocation. Clinical assessments were performed on day 1 (at baseline) and day 7 of hospital admission (or at discharge, whichever occurred first). The primary outcome was functional outcome assessed by the modified Rankin Scale (mRS) at 90 days and analysed using ordinal logistic regression in the intention-to-treat population. This trial is registered with EudraCT (2014-000096-80), ClinicalTrials.gov (NCT03181360), and ISRCTN (10601890).

FINDINGS

From June 12, 2017, to Sept 30, 2021, 578 of the required 600 patients were enrolled (288 randomly assigned to the tenecteplase group and 290 to the control group [intention-to-treat population]). The median age of participants was 73·7 years (IQR 65·9-81·1). 332 (57%) of 578 participants were male and 246 (43%) were female. Treatment with tenecteplase was not associated with better functional outcome, according to mRS score at 90 days (adjusted OR 1·18, 95% CI 0·88-1·58; p=0·27). Mortality at 90 days did not significantly differ between treatment groups (28 [10%] patients in the tenecteplase group and 23 [8%] in the control group; adjusted HR 1·29, 95% CI 0·74-2·26; p=0·37). Symptomatic intracranial haemorrhage occurred in six (2%) patients in the tenecteplase group versus three (1%) in the control group (adjusted OR 2·17, 95% CI 0·53-8·87; p=0·28), whereas any intracranial haemorrhage occurred in 33 (11%) versus 30 (10%) patients (adjusted OR 1·14, 0·67-1·94; p=0·64).

INTERPRETATION

In patients with wake-up stroke selected with non-contrast CT, treatment with tenecteplase was not associated with better functional outcome at 90 days. The number of symptomatic haemorrhages and any intracranial haemorrhages in both treatment groups was similar to findings from previous trials of wake-up stroke patients selected using advanced imaging. Current evidence does not support treatment with tenecteplase in patients selected with non-contrast CT.

FUNDING

Norwegian Clinical Research Therapy in the Specialist Health Services Programme, the Swiss Heart Foundation, the British Heart Foundation, and the Norwegian National Association for Public Health.

1230 PALLIATIVE CARE MOVEMENT DISORDERS MULTIDISCIPLINARY MEETING

Introduction

It is well recognised that patients with Parkinson’s disease (PD) have significant symptom burden in advanced stages of their disease. Integration of movement disorder and palliative care services has been limited by concerns about resource and sustainability. We present our experience of establishing a movement disorders palliative care multidisciplinary meeting.

Method

In 2019 we established a multidisciplinary virtual bimonthly meeting between movement disorders and palliative care specialists. Referrals were accepted from movement disorder specialists, community Parkinson’s practitioners and palliative care specialists. Referring clinicians all actively applied primary palliative care approaches within their existing services. Aims of the meeting were to facilitate holistic management of complex needs, support advance care planning (ACP) and consider referral to specialist palliative care services.

Result

37 patients in total were discussed over a 2-year period (although the service was limited for a time due to COVID pressures). On average 3 new patients were discussed per meeting. Reasons for referral included motor and non-motor symptoms, support with ACP, medication advice, caregiver concerns and emotional distress. Meeting outcomes included medication adjustments, expediting reviews, hospice support, carer support, and referral to other services. Since the meetings started 23 (62%) patients have died. Of these, 30% died in hospital compared with the national average of 43.4%. The average between discussion at the meeting and death was 139 days. The meeting has generated education opportunities, triggered joint assessments and a professionals’ framework for the palliative management of patients with a movement disorder.

Conclusions

We present the experience of an MDT embedded within an early integrated palliative care service for movement disorders. The MDT has strengthened partnership working and findings suggest that alongside active primary palliative care, specialist palliative care for PD can be sustainable and resource efficient in a UK setting.

Predictors and risk factors for admission to critical care in cervicofacial infections: a Maxillofacial Trainee Research Collaborative (MTReC) study

Cervicofacial infections carry significant morbidity. Patients present on a broad spectrum of severity, with some requiring outpatient management and others admission to higher level care. Recognition of risk factors is helpful in decision making regarding the need for admission to higher level care. Prospective data were captured on 1002 patients in 25 centres across 17 regions of the United Kingdom (UK) by the Maxillofacial Trainee Research Collaborative (MTReC). Patients admitted to critical care were compared with those who received ward-level care. Multivariate and receiver operating characteristic curve analyses were used to identify predictors for critical care admission. Our results show that the best predictor for critical care admission is the presence of three or more features of airway compromise (AUC 0.779), followed by C-reactive protein (CRP) >100 mg/L (OR 2.70; 95% CI 1.59 to 4.58; p < 0.005), submandibular space involvement (OR 3.82; 95% CI 1.870 to 7.81; p = 0.003), white cell count (WCC) >12 × 10⁹/ dl (1.05; 95% CI 1.01 to 1.10; p = 0.03), and positive systemic inflammatory response syndrome criteria (OR 2.78; CI 1.35 to 5.80; p = 0.006). Admission to critical care is multifactorial, however, the presence of three or more features of airway compromise is the best predictor. Awareness of this alongside other key clinical findings in cervicofacial infections may allow for the early recognition of patients who may require escalation to critical care.

Renal replacement and extracorporeal therapies in critical care: current and future directions

There are a wide number of indications for extracorporeal therapies in the critical care environment. A common indication seen by the acute physician is continuous renal replacement therapy (CRRT) in a proportion of patients with acute kidney injury. It is therefore important that acute physicians have a sound understanding of the principles of CRRT in the acutely unwell patient. This review will outline the indications for its use, commonly used methods and anticoagulation considerations. It will discuss when to start and stop CRRT as well as describing potential treatment complications. This review will also discuss the role of therapeutic plasma exchange in critical care and novel extracorporeal therapies including blood purification in sepsis and carbon dioxide removal in acute respiratory distress syndrome and acute exacerbations of obstructive lung disease. Extracorporeal membrane oxygenation is outside of the scope of this article.

Improved diagnostic accuracy for apical hypertrophic cardiomyopathy

Introduction

The diagnosis of apical hypertrophic cardiomyopathy (ApHCM) is contingent on demonstrating apical maximum wall thickness (MWT) of ≥15mm; the same threshold as other HCM subtypes. However, the myocardium naturally tapers towards the apex in healthy individuals, so ≥15mm MWT is proportionately higher in the apex than in naturally thicker basal segments. Using cardiac magnetic resonance (CMR), relative ApHCM has been described (typical ECG features, loss of apical tapering, cavity obliteration but hypertrophy &lt;15mm). Wall thickness measurement using machine learning now exceeds human performance.

Purpose

We aimed to redefine the optimal diagnostic threshold for ApHCM using segment-specific criteria based on a large cohort of healthy control subjects.

Methods

Segmental wall thickness was measured using healthy subjects from the UK Biobank using a clinically validated machine learning algorithm1,2. A normative reference range was established for all 16 segments, conditioned to body surface area (BSA), sex and age. Derived segment-specific wall thickness thresholds were used to define optimal disease thresholds for patients clinically managed with overt (MWT ≥15mm) and relative ApHCM (MWT &lt;15mm, but typical ECG and imaging findings).

Results

4118 UK biobank subjects were used to define normal segmental thicknesses and reference ranges. These were applied to ApHCM (73 overt, 31 relative). There were no apical wall thickness age related differences. The upper limit of the 95% confidence interval corresponded to a combined maximum apical MWT for both males and females of 10.4mm using non-indexed measurement, or 5.6mm/m2 when indexed to BSA. Non-indexed segmental threshold identified 100% of ApHCM patients (true positives), 81% (25 of 31) relative ApHCM and 3% (115 of 4118) of healthy UK biobank subjects (false positives). Indexed segmental thresholds improved the diagnostic potential in relative ApHCM without an increase in false positives (100% of ApHCM patients, 84% (26 of 31) of relative ApHCM patients, and 3% healthy UK biobank (127 of 4118).

Conclusion

We propose new diagnostic criteria for ApHCM using segmental indexed apical wall thickness of &gt;5.6 mm/m2 to better identify inappropriate apical hypertrophy in those whose wall thickness does not meet current criteria for diagnosis.

Funding Acknowledgement

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

Cardiac magnetic resonance imaging predictors of ventricular arrhythmia in mid-cavity obstructive hypertrophic cardiomyopathy

Background/Introduction

Left ventricular (LV) mid-cavity obstruction (LVMCO) in hypertrophic cardiomyopathy (HCM) is an uncommon phenotypic feature predisposed to the formation of myocardial fibrosis and apical aneurysms (LVAA). These features may be independently proarrhythmic, and LVAA is considered a class 2a indication for implantable cardioverter defibrillator (ICD) in current US, but not European guidelines for the primary prevention of sudden cardiac death (SCD). Cardiac magnetic resonance (CMR) imaging is the preferred modality for detecting these and other phenotypic features critical to SCD risk assessment.

Purpose

To assess the ability of CMR imaging parameters to predict occurrence of non-sustained ventricular tachycardia (NSVT) in HCM patients with Doppler-derived evidence of LVMCO.

Methods

Multi-modality imaging records were retrospectively assessed to identify HCM patients with Doppler-LVMCO and CMR scans. CMR images were assessed by an investigator blinded to clinical status. Late gadolinium enhancement (LGE) was quantified using the full-width, half-maximum technique. CMR imaging parameters were assessed for predictive ability using Cox proportional hazards during univariate and multivariate analyses, accounting for time to event (NSVT or censorship of follow-up).

Results

The study cohort included 58 patients (57±11 years, 74% male) with a median follow-up of 6.2 (IQR 4.3) years. Mean mid-cavity gradient was 33±23 mmHg. NSVT was detected in 27/58 (47%) patients, was 4 beats or longer in 23/27 (85%) and was monomorphic in 21/27 (77%).

On univariate analysis, predictors of NSVT during follow-up include LV mass index (HR 1.02, 95% CI 1.00–1.04, p=0.03), LGE in grams (HR 1.04, 95% CI 1.01–1.06, p=0.005), and LVAA (HR 2.57, 95% CI 1.14–5.79, p=0.023). After multivariate adjustment (Table 2), none were significantly associated.

Conclusions

In LVMCO, magnitude of LV hypertrophy, extent of LGE and the presence of an apical aneurysm may not be independent predictors of ventricular arrhythmias. SCD algorithms based on qualitative assessments of these features may overestimate risk.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): National Institute of Health Research (NIHR)

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Quantitative Myocardial Perfusion Predicts Outcomes in Patients With Prior Surgical Revascularization

BACKGROUND

Patients with previous coronary artery bypass graft (CABG) surgery typically have complex coronary disease and remain at high risk of adverse events. Quantitative myocardial perfusion indices predict outcomes in native vessel disease, but their prognostic performance in patients with prior CABG is unknown.

OBJECTIVES

In this study, we sought to evaluate whether global stress myocardial blood flow (MBF) and perfusion reserve (MPR) derived from perfusion mapping cardiac magnetic resonance (CMR) independently predict adverse outcomes in patients with prior CABG.

METHODS

This was a retrospective analysis of consecutive patients with prior CABG referred for adenosine stress perfusion CMR. Perfusion mapping was performed in-line with automated quantification of MBF. The primary outcome was a composite of all-cause mortality and major adverse cardiovascular events defined as nonfatal myocardial infarction and unplanned revascularization. Associations were evaluated with the use of Cox proportional hazards models after adjusting for comorbidities and CMR parameters.

RESULTS

A total of 341 patients (median age 67 years, 86% male) were included. Over a median follow-up of 638 days (IQR: 367-976 days), 81 patients (24%) reached the primary outcome. Both stress MBF and MPR independently predicted outcomes after adjusting for known prognostic factors (regional ischemia, infarction). The adjusted hazard ratio (HR) for 1 mL/g/min of decrease in stress MBF was 2.56 (95% CI: 1.45-4.35) and for 1 unit of decrease in MPR was 1.61 (95% CI: 1.08-2.38).

CONCLUSIONS

Global stress MBF and MPR derived from perfusion CMR independently predict adverse outcomes in patients with previous CABG. This effect is independent from the presence of regional ischemia on visual assessment and the extent of previous infarction.

Myocardial Perfusion Imaging After Severe COVID-19 Infection Demonstrates Regional Ischemia Rather Than Global Blood Flow Reduction

Background: Acute myocardial damage is common in severe COVID-19. Post-mortem studies have implicated microvascular thrombosis, with cardiovascular magnetic resonance (CMR) demonstrating a high prevalence of myocardial infarction and myocarditis-like scar. The microcirculatory sequelae are incompletely characterized. Perfusion CMR can quantify the stress myocardial blood flow (MBF) and identify its association with infarction and myocarditis. Objectives: To determine the impact of the severe hospitalized COVID-19 on global and regional myocardial perfusion in recovered patients. Methods: A case-control study of previously hospitalized, troponin-positive COVID-19 patients was undertaken. The results were compared with a propensity-matched, pre-COVID chest pain cohort (referred for clinical CMR; angiography subsequently demonstrating unobstructed coronary arteries) and 27 healthy volunteers (HV). The analysis used visual assessment for the regional perfusion defects and AI-based segmentation to derive the global and regional stress and rest MBF. Results: Ninety recovered post-COVID patients {median age 64 [interquartile range (IQR) 54-71] years, 83% male, 44% requiring the intensive care unit (ICU)} underwent adenosine-stress perfusion CMR at a median of 61 (IQR 29-146) days post-discharge. The mean left ventricular ejection fraction (LVEF) was 67 ± 10%; 10 (11%) with impaired LVEF. Fifty patients (56%) had late gadolinium enhancement (LGE); 15 (17%) had infarct-pattern, 31 (34%) had non-ischemic, and 4 (4.4%) had mixed pattern LGE. Thirty-two patients (36%) had adenosine-induced regional perfusion defects, 26 out of 32 with at least one segment without prior infarction. The global stress MBF in post-COVID patients was similar to the age-, sex- and co-morbidities of the matched controls (2.53 ± 0.77 vs. 2.52 ± 0.79 ml/g/min, p = 0.10), though lower than HV (3.00 ± 0.76 ml/g/min, p< 0.01). Conclusions: After severe hospitalized COVID-19 infection, patients who attended clinical ischemia testing had little evidence of significant microvascular disease at 2 months post-discharge. The high prevalence of regional inducible ischemia and/or infarction (nearly 40%) may suggest that occult coronary disease is an important putative mechanism for troponin elevation in this cohort. This should be considered hypothesis-generating for future studies which combine ischemia and anatomical assessment.

Prognostic Value of Pulmonary Transit Time and Pulmonary Blood Volume Estimation Using Myocardial Perfusion CMR

OBJECTIVES

The purpose of this study was to explore the prognostic significance of PTT and PBVi using an automated, inline method of estimation using CMR.

BACKGROUND

Pulmonary transit time (PTT) and pulmonary blood volume index (PBVi) (the product of PTT and cardiac index), are quantitative biomarkers of cardiopulmonary status. The development of cardiovascular magnetic resonance (CMR) quantitative perfusion mapping permits their automated derivation, facilitating clinical adoption.

METHODS

In this retrospective 2-center study of patients referred for clinical myocardial perfusion assessment using CMR, analysis of right and left ventricular cavity arterial input function curves from first pass perfusion was performed automatically (incorporating artificial intelligence techniques), allowing estimation of PTT and subsequent derivation of PBVi. Association with major adverse cardiovascular events (MACE) and all-cause mortality were evaluated using Cox proportional hazard models, after adjusting for comorbidities and CMR parameters.

RESULTS

A total of 985 patients (67% men, median age 62 years [interquartile range (IQR): 52 to 71 years]) were included, with median left ventricular ejection fraction (LVEF) of 62% (IQR: 54% to 69%). PTT increased with age, male sex, atrial fibrillation, and left atrial area, and reduced with LVEF, heart rate, diabetes, and hypertension (model r2 = 0.57). Over a median follow-up period of 28.6 months (IQR: 22.6 to 35.7 months), MACE occurred in 61 (6.2%) patients. After adjusting for prognostic factors, both PTT and PBVi independently predicted MACE, but not all-cause mortality. There was no association between cardiac index and MACE. For every 1 × SD (2.39-s) increase in PTT, the adjusted hazard ratio for MACE was 1.43 (95% confidence interval [CI]: 1.10 to 1.85; p = 0.007). The adjusted hazard ratio for 1 × SD (118 ml/m2) increase in PBVi was 1.42 (95% CI: 1.13 to 1.78; p = 0.002).

CONCLUSIONS

Pulmonary transit time (and its derived parameter pulmonary blood volume index), measured automatically without user interaction as part of CMR perfusion mapping, independently predicted adverse cardiovascular outcomes. These biomarkers may offer additional insights into cardiopulmonary function beyond conventional predictors including ejection fraction.

Chiari 1: Is decompression always necessary previous to scoliosis surgery?

The association between Chiari 1 malformation and scoliosis is well known in the literature. Prevalence has increased after the advent of magnetic resonance imaging. In children with this association, prophylactic suboccipital decompression prior to scoliosis correction is a common surgical procedure although the rationale for this surgical management and whether not performing it may lead to spinal cord injury has not been clearly elucidated. We conducted a systematic review of the literature with the aim to obtain strong data to support the hypothesis that it is safe to proceed with scoliosis correction without prior prophylactic suboccipital decompression for Chiari 1 in an asymptomatic population. Using the Prisma methodology, we analyzed 3250 studies published between 1972 and 2018. Only four studies met the inclusion criteria. None of the studies had a level of evidence high enough to recommend prophylactic decompression previous to correction of the spinal deformity.

A Comparative study on the Effectiveness of Augmented Reality on Denture Tooth Selection

One of the most difficult aspects of providing removable dentures, for both the patient and the dentist, is the tooth selection process. The aim of this study was to assess the effectiveness of augmented reality (AR) on patient experience of the tooth selection process.

MATERIALS AND METHODS

3D scanning of upper anterior teeth of various shapes and sizes allowed for the creation of a virtual library that were subsequently used to programme an AR software application, 'ToothPick'. Seventeen participants were recruited to a comparative study at Leeds Dental Institute, over two clinical appointments, to trial the app and complete a 10-question survey to assess the efficacy of AR simulation. The sample size response generated outcome variables for 'perceived usefulness' and 'perceived ease of use' from the perspectives of the patient, dentist and technician.

RESULTS

By the second appointment, 86% of participants preferred the app over the conventional methods for selection of denture teeth due to increased ease of use and accuracy that AR simulation had in replicating the wax try-in.

CONCLUSION

The sample population favoured the adoption of AR technology to select denture teeth from the perspective of both the patient and the clinician.

Comparison of the prognostic value of stress and rest pulmonary transit time estimation using myocardial perfusion CMR

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation Clinical Research Training Fellowship

Background

Pulmonary transit time (PTT) is a quantitative biomarker of cardiopulmonary status. Rest PTT was previously shown to predict outcomes in specific disease models, but clinical adoption is hindered but challenges in data acquisition. Whether evaluation of PTT during stress encodes incremental prognostic information has not been previously investigated as scale.

Objectives

To compare the prognostic value of stress and rest PTT derived from a fully automated, in-line method of estimation using perfusion CMR, in a large patient cohort.

Methods

A retrospective two-center study of patients referred clinically for adenosine stress myocardial perfusion assessment using CMR. Analysis of right and left ventricular cavity arterial input function curves from first pass perfusion was performed automatically, allowing the in-line estimation of both rest and stress PTT. Association with major adverse cardiovascular events (MACE) was evaluated. MACE was defined as a composite outcome of myocardial infarction, stroke, heart failure admission and ventricular tachycardia or appropriate ICD treatment (including ICD shock and/or anti-tachycardia pacing).

Results

985 patients (67% male, median age 62 years (IQR 52,71)) were included, with median left ventricular ejection fraction (LVEF) of 62% (IQR 54-69). Median stress PTT was shorter than rest PTT 6.2 (IQR 5.1, 7.7) seconds versus 7.7 (IQR, 6.4, 9.2) seconds. Stress and rest PTT were highly correlated (r = 0.69; p &lt; 0.001). Stress PTT also correlated with LVEF (r=-0.37), stress MBF (r=-0.31), LVEDVi (r = 0.24), LA area index (r = 0.32) (p &lt; 0.001 for all). Over a median follow-up period of 28.6 (IQR, 22.6 35,7) months, MACE occurred in 61 (6.2%) patients. After adjusting for prognostic factors, both rest and stress PTT, independently predicted MACE, but not all-cause mortality. For every 1xSD (2.39s) increase in rest PTT the adjusted hazard ratio (HR) for MACE was 1.43 (95% CI 1.10-1.85, p = 0.007). The hazard ratio for one standard deviation (2.64s) increase in stress PTT was 1.34 (95% CI 1.048-1.723; p = 0.020) after adjusting for age, LVEF, hypertension, diabetes, sex and presence of LGE

Conclusions

In this 2-center study of 985 patients, we deploy a fully automated method of PTT estimation using perfusion mapping with CMR and show that both stress and rest PTT are independently associated with adverse cardiovascular outcomes. In this patient cohort, there is no clear incremental prognostic value of stress PTT, over its evaluation during rest.

Figure 1. Stress and Rest Pulmonary Transit Time estimation using myocardial perfusion CMR

Figure 2. Event-free survival curves for major adverse cardiovascular events (Heart failure hospitalization, myocardial infarction, stroke and ventricular tachycardia/ICD treatment) according to mean rest PTT (8.05seconds) and mean stress PTT (6.7seconds). Log-rank for both p &lt; 0.05

Prospective case-control study of cardiovascular abnormalities six months following mild COVID-19 in healthcare workers

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): Barts Charity UCLH Charity

OnBehalf

COVIDsortium

Background

Recent CMR studies have reported cardiac abnormalities after COVID-19 are common, even after mild, non-hospitalised illness with evidence of ongoing myocardial inflammation.  Such a prevalence of chronic myocarditis after mild disease has prompted societal concerns in diverse domains, and suggests that screening should be considered post COVID-19, even in asymptomatic individuals.  Cardiovascular magnetic resonance (CMR) has proven utility for diagnosis in patients with COVID-19 infection and elevated troponin from unclear causes by measuring cardiac structure, function, myocardial scar (late gadolinium enhancement) and oedema (T1 and T2 mapping).

Objectives

We aimed to determine the prevalence and extent of late cardiac and cardiovascular sequelae after mild non-hospitalised SARS-CoV-2 infection.

Methods

Participants were recruited from COVIDsortium, a three-hospital prospective study of 731 healthcare workers who underwent first wave weekly symptom, PCR and serology assessment over 4 months, with seroconversion in 21.5% (n = 157). At 6 months post infection, 74 seropositive and 75 age-, sex-, ethnicity-matched seronegative controls were recruited for cardiovascular phenotyping (comprehensive phantom-calibrated Cardiovascular Magnetic Resonance and blood biomarkers). Analysis was blinded, using objective AI analytics where available.

Results

149 subjects (mean age 37 years, range 18-63, 58% female) were recruited. Seropositive infections had been mild with case definition/non-case definition/asymptomatic disease in 45(61%), 18(24%) and 11(15%) with one person hospitalised (for 2 days). Between seropositive and seronegative groups, there were no differences in cardiac structure (left ventricular volumes, mass; atrial area), function (ejection fraction, global longitudinal shortening, aortic distensibility), tissue characterisation (T1, T2, ECV mapping, late gadolinium enhancement) or biomarkers (troponin, NT-proBNP).  With abnormal defined by the 75 seronegatives (2 standard deviations from mean, e.g. EF &lt; 54%, septal T1 &gt; 1072ms, septal T2 &gt; 52.4ms), individuals had abnormalities including reduced EF (n = 2, minimum 50%), T1 elevation (n = 6), T2 elevation (n = 9), LGE (n = 13, median 1%, max 5% of myocardium), biomarker elevation (borderline troponin elevation in 4; all NT-proBNP normal). These were distributed equally between seropositive and seronegative individuals.

Conclusions

Cardiovascular abnormalities are no more common in seropositive vs seronegative otherwise healthy, workforce representative individuals 6 months post mild SARS-CoV-2 infection.  Our study provides societal reassurance for the cardiovascular health of working-aged individuals with convalescence from mild SARS-CoV-2. Screening asymptomatic individuals following mild diseases is not indicated.

Use of quantitative cardiovascular magnetic resonance myocardial perfusion mapping for characterization of ischemia in patients with left internal mammary coronary artery bypass grafts

BACKGROUND

Quantitative myocardial perfusion mapping using cardiovascular magnetic resonance (CMR) is validated for myocardial blood flow (MBF) estimation in native vessel coronary artery disease (CAD). Following coronary artery bypass graft (CABG) surgery, perfusion defects are often detected in territories supplied by the left internal mammary artery (LIMA) graft, but their interpretation and subsequent clinical management is variable.

METHODS

We assessed myocardial perfusion using quantitative CMR perfusion mapping in 38 patients with prior CABG surgery, all with angiographically-proven patent LIMA grafts to the left anterior descending coronary artery (LAD) and no prior infarction in the LAD territory. Factors potentially determining MBF in the LIMA-LAD myocardial territory, including the impact of delayed contrast arrival through the LIMA graft were evaluated.

RESULTS

Perfusion defects were reported on blinded visual analysis in the LIMA-LAD territory in 27 (71%) cases, despite LIMA graft patency and no LAD infarction. Native LAD chronic total occlusion (CTO) was a strong independent predictor of stress MBF (B = - 0.41, p = 0.014) and myocardial perfusion reserve (MPR) (B = - 0.56, p = 0.005), and was associated with reduced stress MBF in the basal (1.47 vs 2.07 ml/g/min; p = 0.002) but not the apical myocardial segments (1.52 vs 1.87 ml/g/min; p = 0.057). Extending the maximum arterial time delay incorporated in the quantitative perfusion algorithm, resulted only in a small increase (3.4%) of estimated stress MBF.

CONCLUSIONS

Perfusion defects are frequently detected in LIMA-LAD subtended territories post CABG despite LIMA patency. Although delayed contrast arrival through LIMA grafts causes a small underestimation of MBF, perfusion defects are likely to reflect true reductions in myocardial blood flow, largely due to proximal native LAD disease.

The effect of coincidental SARS-CoV-2 infection on pre-operative cardiopulmonary exercise testing

This case report demonstrates the significant impact active infection with SARS-CoV-2 can have on functional capacity evaluated by cardiopulmonary exercise testing, even in minimally symptomatic individuals. A 75-year-old man underwent cardiopulmonary exercise testing before a right hemicolectomy; SARS-CoV-2 was incidentally diagnosed following his test. The patient underwent a period of isolation and recovery before a second pre-operative cardiopulmonary exercise test 6 weeks later. His resting pulmonary function tests did not vary between tests but his peak work, anaerobic threshold, oxygen pulse, pulse oximetry nadir, ventilation perfusion matching and heart rate response to exercise all improved significantly after this recovery period. These are unique results that add to the existing knowledge of the pathophysiology and management of SARS-CoV-2 in the peri-operative setting. While our patient demonstrated dramatic improvement in his functional capacity following 6 weeks of recovery, he remained in a high-risk group for surgery according to our local guidelines. Cardiopulmonary exercise testing has a valuable role in individualised risk assessment and shared decision-making in complex, urgent surgical cases where the benefits of delaying surgery to recover from SARS-CoV-2 infection should be balanced against the potential risks.

OP0241 SERIOUS INFECTION WITH TOCILIZUMAB COMPARED TO TNF-INHIBITORS AND OTHER BDMARDS IN RHEUMATOID ARTHRITIS PATIENTS: DOES LINE OF THERAPY MATTER?

Background:

In the real-world, tocilizumab is prescribed to a population of patients different from those prescribed TNF-inhibitors, often older with longer disease duration, worse functional status and more previous b- or tsDMARDs.

Objectives:

The aim of this study was to evaluate if and how the risk of serious infection on tocilizumab and other bDMARDs differs when stratifying by line of therapy in a real-world population of rheumatoid arthritis patients.

Methods:

We included patients registered in the BSRBR-RA treated with tocilizumab, etanercept, adalimumab, infliximab, certolizumab, abatacept or rituximab, including biosimilars. Primary outcome was the occurrence of a serious infection (defined as infection requiring hospitalisation, intravenous antibiotics or resulting in death). Primary covariate of interest was line of therapy (from first to fifth line of therapy). Every change to another b- or tsDMARD was considered a new line of therapy, but not a change between a bio-original and a biosimilar.

Hazard ratios (HR) of serious infections were estimated using an inverse probability weighted Cox regression, based on a propensity score including baseline patient and disease characteristics, and adjusting for time in study (see Table). The reference group was etanercept, which included the highest number of patients. Treatment exposure was analysed without and with stratification by line of therapy.

Table.NETNTCZADAIFXCERTRTXABAN33,91610,6552,6327,8394,4301,6165,5561,188Patient-years19,1294,34214,5048,1352,72612,0091,686Infections8071926814817443374Incidence per 100 patient-years (95%CI)4.2 (3.9-4.5)4.4 (3.8-5.1)4.7 (4.4-5.1)5.9 (5.4-6.6)2.7 (2.2-3.4)3.6 (3.3-4.0)4.0 (3.2-5.1)Unadjusted HR (95%CI)Ref.1.0 (0.9-1.2)1.1 (1.0-1.2)1.4 (1.2-1.6)0.6 (0.5-0.8)0.9 (0.8-1.0)0.9 (0.7-1.2)Adjusted HR* (95% CI)All lines of therapy33,916Ref.1.2 (1.0-1.5)1.1 (1.0-1.3)1.3 (1.1-1.6)0.8 (0.6-1.0)1.0 (0.8-1.1)1.2 (0.8-1.7)1stline16,152Ref.0.9 (0.5-1.5)1.1 (1.0-1.3)1.3 (1.1-1.6)0.6 (0.5-0.9)1.6 (1.2-2.2)-2ndline10,378Ref.1.4 (1.0-2.0)1.1 (0.9-1.4)1.1 (0.7-1.6)0.9 (0.4-2.2)1.0 (0.8-1.2)0.9 (0.5-1.9)3rdline4,676Ref.1.4 (0.9-2.3)1.3 (0.8-2.2)0.9 (0.4-1.9)0.9 (0.3-2.9)0.8 (0.5-1.2)1.5 (0.7-2.9)4thline1,947Ref.1.0 (0.5-2.3)1.3 (0.4-3.7)1.4 (0.5-4.4)0.2 (0.0—2.1)1.0 (0.5.-2.2)0.9 (0.4-2.3)5thline763Ref.0.9 (0.2-3.5)2.5 (0.5-12.4)0.7 (0.1-7.1)3.3 (0.6-18.4)0.9 (0.2-3.5)0.8 (0.2-3.5)

ABA, abatacept; ADA, adalimumab; CERT, certolizumab; ETN, etanercept; HR, hazard ratio; IFX, infliximab; RTX, rituximab; TCZ, tocilizumab

*Adjusted using inverse probably weighting (with age, gender, concomitant steroids, concomitant DMARDs, comorbidities, seropositivity, smoking, disease duration, HAQ and DAS28 at baseline in the model) and time since study entry (categorised from 0 to 4, 0 starting just before or at the moment of entering study, 1 starting during the first year, 2 starting during the second year until 4 for the fourth year and more)

Results:

A total of 33,916 treatment courses were included (Table) contributing to 62,532 years of follow-up. Compared to etanercept, participants starting abatacept, tocilizumab and rituximab were older, had more previous bDMARDs, longer disease duration and more comorbidities. The crude HR of serious infections were higher with infliximab and adalimumab, lower with certolizumab and rituximab, and not significantly different for abatacept and tocilizumab compared to etanercept. After adjustment, HR of serious infections were higher with tocilizumab, adalimumab and infliximab. However, when stratified by line of therapy, HR were no longer significantly different compared to etanercept for tocilizumab, adalimumab and infliximab for most lines of therapy.

Conclusion:

Whilst initially there appears to be a difference in rates of serious infection between biologic therapies, line of therapy may be a confounding factor when comparing the risk of serious infections between bDMARDs.

Disclosure of Interests:

Kim Lauper Consultant of: Gilead-galapagos, Grant/research support from: AbbVie, Lianne Kearsley-Fleet: None declared, Rebecca Davies: None declared, Kath Watson: None declared, Mark Lunt: None declared, Kimme Hyrich Consultant of: AbbVie, Grant/research support from: Pfizer, BMS

Reduction in antimicrobial resistance prevalence in Escherichia coli from a pig farm following withdrawal of group antimicrobial treatment

An important element in the control of antimicrobial resistance (AMR) is reduction in antimicrobial usage. In the veterinary sector individual antimicrobial treatment of livestock, rather than the use of group treatment, can help achieve this goal. The aim of this study was to investigate how cessation of group antimicrobial treatment impacted the prevalence of AMR in commensal Escherichia coli in pigs at one farm over an 11-month period. Minimum inhibitory concentrations of eight antimicrobials were determined for 259 E. coli isolates collected during the study. A significant reduction in the prevalence of multidrug resistance and a significant increase in the proportion of full susceptibility to the panel of nine antimicrobials tested was seen after 11 months. Whole genome sequencing of 48 multidrug resistant isolates revealed E. coli clones that persisted across multiple visits and provided evidence for the presence of plasmids harbouring AMR genes shared across multiple E. coli lineages. E. coli were also isolated from on-farm environmental samples. Whole genome sequencing of one multidrug resistant isolate obtained from cleaning tools showed it was clonal to pig-derived E. coli that persisted on the farm for 11 months. In this study we provide evidence that withdrawal of group antimicrobial use leads to significant reductions in key indicators for AMR prevalence and the importance of the farm environment as a reservoir of resistant bacteria. These findings support policy makers and producers in the implementation of measures to control AMR and reduce antimicrobial use.

Acute kidney injury following endovascular intervention for peripheral artery disease

BACKGROUND

The incidence of, and risk factors for, acute kidney injury (AKI) after endovascular intervention for peripheral artery disease (PAD) remain unknown. The aim of this study was to assess the proportion of patients who develop AKI and explore the risk factors.

METHODS

Prospectively collected data on patients undergoing femoropopliteal endovascular intervention for symptomatic PAD across three vascular centres were analysed. The proportion of patients developing AKI (according to the Kidney Disease Improving Global Outcomes definition) within 48 h, and the proportion developing the composite Major Adverse Kidney Events (MAKE) endpoints (death, dialysis, drop in estimated glomerular filtration rate at least 25 per cent) at 30 days (MAKE30) and remains 90 days (MAKE90) were calculated. Multivariable regression analysis was used to assess predictors of AKI, and the association between AKI and death.

RESULTS

Some 2041 patients were included in the analysis. AKI developed in 239 patients (11.7 per cent), with 47 (2.3 per cent) requiring dialysis within 30 days, and 18 (0.9 per cent) requiring ongoing dialysis. The MAKE30 and MAKE90 composite endpoints were reached in 358 (17.5 per cent) and 449 (22.0 per cent) patients respectively. Risk factors for AKI were age, sex, congestive heart failure, chronic limb-threatening ischaemia, emergency procedure, and pre-existing chronic kidney disease. AKI, dementia, congestive heart failure, and major amputation were risk factors for medium-term mortality.

CONCLUSION

AKI is a common complication after intervention for PAD and is associated with medium-term mortality.

Dental school before or after core surgical training? Consideration for medically qualified junior trainees prior to embarking on - their second degree

Medical graduates who are interested in pursuing a career in oral and maxillofacial surgery require attainment of a degree in dental surgery (BDS). A common question facing this cohort of junior trainees is whether to study dentistry before or after core surgical training; both routes have advantages and disadvantages that must be considered. Here we provide our perspective into this common dilemma.

Optimal symptom combinations to aid COVID-19 case identification: Analysis from a community-based, prospective, observational cohort

Objectives

Diagnostic work-up following any COVID-19 associated symptom will lead to extensive testing, potentially overwhelming laboratory capacity whilst primarily yielding negative results. We aimed to identify optimal symptom combinations to capture most cases using fewer tests with implications for COVID-19 vaccine developers across different resource settings and public health.

Methods

UK and US users of the COVID-19 Symptom Study app who reported new-onset symptoms and an RT-PCR test within seven days of symptom onset were included. Sensitivity, specificity, and number of RT-PCR tests needed to identify one case (test per case [TPC]) were calculated for different symptom combinations. A multi-objective evolutionary algorithm was applied to generate combinations with optimal trade-offs between sensitivity and specificity.

Findings

UK and US cohorts included 122,305 (1,202 positives) and 3,162 (79 positive) individuals. Within three days of symptom onset, the COVID-19 specific symptom combination (cough, dyspnoea, fever, anosmia/ageusia) identified 69% of cases requiring 47 TPC. The combination with highest sensitivity (fatigue, anosmia/ageusia, cough, diarrhoea, headache, sore throat) identified 96% cases requiring 96 TPC.

Interpretation

We confirmed the significance of COVID-19 specific symptoms for triggering RT-PCR and identified additional symptom combinations with optimal trade-offs between sensitivity and specificity that maximize case capture given different resource settings.

Optimal symptom combinations to aid COVID-19 case identification: analysis from a community-based, prospective, observational cohort

OBJECTIVES

Diagnostic work-up following any COVID-19 associated symptom will lead to extensive testing, potentially overwhelming laboratory capacity whilst primarily yielding negative results. We aimed to identify optimal symptom combinations to capture most cases using fewer tests with implications for COVID-19 vaccine developers across different resource settings and public health.

METHODS

UK and US users of the COVID-19 Symptom Study app who reported new-onset symptoms and an RT-PCR test within seven days of symptom onset were included. Sensitivity, specificity, and number of RT-PCR tests needed to identify one case (test per case [TPC]) were calculated for different symptom combinations. A multi-objective evolutionary algorithm was applied to generate combinations with optimal trade-offs between sensitivity and specificity.

FINDINGS

UK and US cohorts included 122,305 (1,202 positives) and 3,162 (79 positive) individuals. Within three days of symptom onset, the COVID-19 specific symptom combination (cough, dyspnoea, fever, anosmia/ageusia) identified 69% of cases requiring 47 TPC. The combination with highest sensitivity (fatigue, anosmia/ageusia, cough, diarrhoea, headache, sore throat) identified 96% cases requiring 96 TPC.

INTERPRETATION

We confirmed the significance of COVID-19 specific symptoms for triggering RT-PCR and identified additional symptom combinations with optimal trade-offs between sensitivity and specificity that maximize case capture given different resource settings.

Temporal changes in the gut microbiota in farmed Atlantic cod (Gadus morhua) outweigh the response to diet supplementation with macroalgae

BACKGROUND

Aquaculture successfully meets global food demands for many fish species. However, aquaculture production of Atlantic cod (Gadus morhua) is just 2.5% of total market production. For cod farming to be a viable economic venture specific challenges on how to increase growth, health and farming productivity need to be addressed. Feed ingredients play a key role here. Macroalgae (seaweeds) have been suggested as a functional feed supplement with both health and economic benefits for terrestrial farmed animals and fish. The impact of such dietary supplements to cod gut integrity and microbiota, which contribute to overall fish robustness is unknown. The objective of this study was to supplement the diet of juvenile Atlantic cod with macroalgae and determine the impacts on fish condition and growth, gut morphology and hindgut microbiota composition (16S rRNA amplicon sequencing). Fish were fed one of three diets: control (no macroalgal inclusion), 10% inclusion of either egg wrack (Ascophyllum nodosum) or sea lettuce (Ulva rigida) macroalgae in a 12-week trial.

RESULTS

The results demonstrated there was no significant difference in fish condition, gut morphology or hindgut microbiota between the U. rigida supplemented fish group and the control group at any time-point. This trend was not observed with the A. nodosum treatment. Fish within this group were further categorised as either 'Normal' or 'Lower Growth'. 'Lower Growth' individuals found the diet unpalatable resulting in reduced weight and condition factor combined with an altered gut morphology and microbiome relative to the other treatments. Excluding this group, our results show that the hindgut microbiota was largely driven by temporal pressures with the microbial communities becoming more similar over time irrespective of dietary treatment. The core microbiome at the final time-point consisted of the orders Vibrionales (Vibrio and Photobacterium), Bacteroidales (Bacteroidetes and Macellibacteroides) and Clostridiales (Lachnoclostridium).

CONCLUSIONS

Our study indicates that U. rigida macroalgae can be supplemented at 10% inclusion levels in the diet of juvenile farmed Atlantic cod without any impact on fish condition or hindgut microbial community structure. We also conclude that 10% dietary inclusion of A. nodosum is not a suitable feed supplement in a farmed cod diet.

Diagnostic performance of virtual fractional flow reserve derived from routine coronary angiography using segmentation free reduced order (1-dimensional) flow modelling

Introduction

Fractional flow reserve (FFR) improves assessment of the physiological significance of coronary lesions compared with conventional angiography. However, it is an invasive investigation. We tested the performance of a virtual FFR (1D-vFFR) using routine angiographic images and a rapidly performed reduced order computational model.

Methods

Quantitative coronary angiography (QCA) was performed in 102 with coronary lesions assessed by invasive FFR. A 1D-vFFR for each lesion was created using reduced order (one-dimensional) computational flow modelling derived from conventional angiographic images and patient specific estimates of coronary flow. The diagnostic accuracy of 1D-vFFR and QCA derived stenosis was compared against the gold standard of invasive FFR using area under the receiver operator characteristic curve (AUC).

Results

QCA revealed the mean coronary stenosis diameter was 44% ± 12% and lesion length 13 ± 7 mm. Following angiography calculation of the 1DvFFR took less than one minute. Coronary stenosis (QCA) had a significant but weak correlation with FFR (r = -0.2, p = 0.04) and poor diagnostic performance to identify lesions with FFR <0.80 (AUC 0.39, p = 0.09), (sensitivity - 58% and specificity - 26% at a QCA stenosis of 50%). In contrast, 1D-vFFR had a better correlation with FFR (r = 0.32, p = 0.01) and significantly better diagnostic performance (AUC 0.67, p = 0.007), (sensitivity - 92% and specificity - 29% at a 1D-vFFR of 0.7).

Conclusions

1D-vFFR improves the determination of functionally significant coronary lesions compared with conventional angiography without requiring a pressure-wire or hyperaemia induction. It is fast enough to influence immediate clinical decision-making but requires further clinical evaluation.

Modelling scenarios of environmental recovery after implementation of controls on emissions of persistent organic pollutants

Comparison of monitoring data with toxicologically-derived environmental quality standards (EQSs) forms the basis of assessments of the quality status of the water environment. Having established the status quo, the logical next step is to address instances of non-compliance with EQSs by applying remedial measures, including reducing the use or at least the emission of the substances of concern or by taking steps to reduce concentrations already present using technological solutions such as enhanced wastewater treatment. The selection of suitable remedial measures must be a compromise between cost, likely effectiveness and the timescale over which improvements might be acceptable. The decision on overall environmental management has also to take into account the need for demonstrable progress; this might mean that it is preferable to address some more readily achievable goal rather than to attempt to solve a more serious, but ultimately intractable problem. This paper describes the development and application of a generic modelling tool that provides a way of assessing the potential requirements for remedial actions and their likely outcomes over a timescale of up to forty years taking account of sediment partitioning, environmental degradation and biological accumulation. The tool was validated using a detailed UK wastewater treatment works effluent discharge dataset. Examples involving several chemicals that are of current concern are provided. Some substances (e.g. tributyltin, PFOS) are identified as likely to meet EQS values in sediments or biota in a relatively short timescale; others (PAHs, DEHP) appear to represent more intractable problems.

Physiological performance and inflammatory markers as indicators of complications after oesophageal cancer surgery

BACKGROUND

The extent to which physiological factors influence outcome following oesophageal cancer surgery is poorly understood. This study aimed to evaluate the extent to which cardiorespiratory fitness and selected metabolic factors predicted complications after surgery for carcinoma.

METHODS

Two hundred and twenty-five consecutive patients underwent preoperative cardiopulmonary exercise testing to determine peak oxygen uptake ( V ˙ o_2peak ), anaerobic threshold and the ventilatory equivalent for carbon dioxide ( V ˙ e/ V ˙ co₂ ). Cephalic venous blood was assayed for serum C-reactive protein (CRP) and albumin levels, and a full blood count was done. The primary outcome measure was the Morbidity Severity Score (MSS).

RESULTS

One hundred and ninety-eight patients had anatomical resection. A high MSS (Clavien-Dindo grade III or above) was found in 48 patients (24·2 per cent) and was related to an increased CRP concentration (area under the receiver operating characteristic (ROC) curve (AUC) 0·62, P = 0·001) and lower V ˙ o_2peak (AUC 0·36, P = 0·003). Dichotomization of CRP levels (above 10 mg/l) and V ˙ o_2peak (below 18·6 ml per kg per min) yielded adjusted odds ratios (ORs) for a high MSS of 2·86 (P = 0·025) and 2·92 (P = 0·002) respectively. Compared with a cohort with a low Combined Inflammatory and Physiology Score (CIPS), the OR was 1·70 (95 per cent c.i. 0·85 to 3·39) for intermediate and 27·47 (3·12 to 241·69) for high CIPS (P < 0·001).

CONCLUSION

CRP and V ˙ o_2peak were independently associated with major complications after potentially curative oesophagectomy for cancer. A composite risk score identified a group of patients with a high risk of developing complications.