Post-acute COVID syndrome (long COVID): What should radiographers know and the potential impact for imaging services

Objectives

The COVID-19 pandemic caused an unprecedented health crisis resulting in over 6 million deaths worldwide, a figure, which continues to grow. In addition to the excess mortality, there are individuals who recovered from the acute stages, but suffered long-term changes in their health post COVID-19, commonly referred to as long COVID. It is estimated there are currently 1.8 million long COVID sufferers by May 2022 in the UK alone. The aim of this narrative literature review is to explore the signs, symptoms and diagnosis of long COVID and the potential impact on imaging services.

Key findings

Long COVID is estimated to occur in 9.5% of those with two doses of vaccination and 14.6% if those with a single dose or no vaccination. Long COVID is defined by ongoing symptoms lasting for 12 or more weeks post acute infection. Symptoms are associated with reductions in the quality of daily life and may involve multisystem manifestations or present as a single symptom.

Conclusion

The full impact of long COVID on imaging services is yet to be realised, but there is likely to be significant increased demand for imaging, particularly in CT for the assessment of lung disease. Educators will need to include aspects related to long COVID pathophysiology and imaging presentations in curricula, underpinned by the rapidly evolving evidence base.

Implications for practice

Symptoms relating to long COVID are likely to become a common reason for imaging, with a particular burden on Computed Tomography services. Planning, education and updating protocols in line with a rapidly emerging evidence base is going to be essential.

O007 Pancreas and islet transplantation in the United Kingdom during the COVID-19 era

Introduction

Methods

Results

Conclusion

Take-home message

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.

In-depth phenotypic characterisation of myocardial fibrosis by cardiovascular magnetic resonance predicts sudden cardiac death in coronary heart disease: a long-term prospective outcome study

Background

Prospective studies harnessing late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) afford the potential to non-invasively characterise the phenotypic substrate for sudden cardiac death (SCD) and simultaneously interrogate its mechanistic drivers.

Purpose

To assess the utility of infarct characterisation by CMR, including scar microstructure analysis, to predict SCD in prospectively investigated patients with coronary heart disease (CHD).

Methods

Patients with stable CHD were prospectively recruited into a registry between August 2009 and January 2016. The primary outcome for this study was SCD or aborted SCD. Patients with a secondary prevention implantable cardioverter defibrillator (ICD) indication were excluded. All patients had CMR with LGE imaging. Infarct quantification (core scar and peri-infarct zone [PIZ]) was performed by an independent level 3 CMR reader. Outcome events were adjudicated by a panel of cardiologists blinded to the CMR data. To investigate fibrosis microstructure, bespoke computational image processing algorithms were applied to the LGE images in order to extract specific morphological and texture related features.

Results

Of 437 patients (mean age 64, mean left ventricular ejection fraction [LVEF] 47%, 91% with LGE) followed for a median of 6.3 years, 49 patients (11.2%) experienced the primary outcome. Patients with higher PIZ mass had an increased risk of the primary outcome (10-year risk 0.7%, 24.0% and 37.8% for patients with PIZ mass <5.66g, 5.66–12.28g and ≥12.29g respectively, P<0.001; figure 1a). On univariable analysis, an increase in PIZ mass and core infarct mass was associated with an increased risk of the primary outcome (per gram: HR 1.12, 95% CI 1.09–1.15, P<0.001 and HR 1.05, 95% CI 1.04–1.06, P<0.001 respectively). PIZ mass and core infarct mass remained independently associated with the primary outcome after adjustment for baseline predictors (per gram: HR 1.10, 95% CI 1.06–1.14, P<0.001 and HR 1.04, 95% CI 1.02–1.06, P<0.001 respectively) and together provided incremental value compared to conventional variables in predicting the endpoint (Harrell's C-statistic 0.76 to 0.82, figure 1b-c). Bespoke analysis of imaging data identified several shape-based scar metrics that associated with the primary outcome (figure 2). These included core infarct transmurality, radiality and interface length (the latter defining the core scar-PIZ boundary length), and the number of PIZ islets.

Conclusions

In this large prospective study of patients with stable CHD, both PIZ mass and core infarct mass independently predicted long-term SCD risk after adjusting for conventional predictors including LVEF. Reassuringly, minimal or absent LGE portended a comparatively low risk of SCD. Analysis of the scar microstructure identified several shape-based features that associated with SCD. These results highlight a potential avenue towards a more personalised approach to ICD implantation decisions.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Lung and Heart Institute, Imperial College London

Monitoring cell-mediated immune responses in AAV gene therapy clinical trials using a validated IFN-γ ELISpot method

Adeno-associated virus (AAV)-based gene therapies have recently shown promise as a novel treatment for hereditary diseases. Due to the viral origin of the vector capsid, however, cellular immune response may be elicited that could eliminate transduced target cells. To monitor cellular immune responses in clinical trials, we optimized and bioanalytically validated a sensitive, robust, and reliable interferon-γ (IFN-γ) enzyme-linked immunospot (ELISpot) assay. For method performance validation, human peripheral blood mononuclear cells (PBMCs) were stimulated with peptides derived from AAV5 capsid proteins and the encoded transgene product, human blood clotting factor VIII (FVIII), in addition to positive controls, such as peptides from the 65-kDa phosphoprotein of cytomegalovirus. We statistically assessed the limit of detection and confirmatory cutpoint, evaluated precision and linearity, and confirmed specificity using HIV peptides. Robustness parameter ranges and sample stability periods were established. The validated IFN-γ ELISpot assay was then implemented in an AAV5-FVIII gene therapy clinical trial. Cellular immune responses against the AAV5 capsid were observed in most participants as soon as 2 weeks following dose administration; only limited responses against the transgene product were detected. These data underscore the value of using validated methods for monitoring cellular immunity in AAV gene therapy trials.

Non-invasive prediction of the mouse tibia mechanical properties from microCT images: comparison between different finite element models

New treatments for bone diseases require testing in animal models before clinical translation, and the mouse tibia is among the most common models. In vivo micro-Computed Tomography (microCT)-based micro-Finite Element (microFE) models can be used for predicting the bone strength non-invasively, after proper validation against experimental data. Different modelling techniques can be used to estimate the bone properties, and the accuracy associated with each is unclear. The aim of this study was to evaluate the ability of different microCT-based microFE models to predict the mechanical properties of the mouse tibia under compressive load. Twenty tibiae were microCT scanned at 10.4 µm voxel size and subsequently compressed at 0.03 mm/s until failure. Stiffness and failure load were measured from the load-displacement curves. Different microFE models were generated from each microCT image, with hexahedral or tetrahedral mesh, and homogeneous or heterogeneous material properties. Prediction accuracy was comparable among models. The best correlations between experimental and predicted mechanical properties, as well as lower errors, were obtained for hexahedral models with homogeneous material properties. Experimental stiffness and predicted stiffness were reasonably well correlated (R2 = 0.53-0.65, average error of 13-17%). A lower correlation was found for failure load (R2 = 0.21-0.48, average error of 9-15%). Experimental and predicted mechanical properties normalized by the total bone mass were strongly correlated (R2 = 0.75-0.80 for stiffness, R2 = 0.55-0.81 for failure load). In conclusion, hexahedral models with homogeneous material properties based on in vivo microCT images were shown to best predict the mechanical properties of the mouse tibia.

The immunopeptidomes of two transmissible cancers and their host have a common, dominant peptide motif

Transmissible cancers are malignant cells that can spread between individuals of a population, akin to both a parasite and a mobile graft. The survival of the Tasmanian devil, the largest remaining marsupial carnivore, is threatened by the remarkable emergence of two independent lineages of transmissible cancer, devil facial tumour (DFT) 1 and devil facial tumour 2 (DFT2). To aid the development of a vaccine and to interrogate how histocompatibility barriers can be overcome, we analysed the peptides bound to major histocompatibility complex class I (MHC‐I) molecules from Tasmanian devil cells and representative cell lines of each transmissible cancer. Here, we show that DFT1 + IFN‐γ and DFT2 cell lines express a restricted repertoire of MHC‐I allotypes compared with fibroblast cells, potentially reducing the breadth of peptide presentation. Comparison of the peptidomes from DFT1 + IFNγ, DFT2 and host fibroblast cells demonstrates a dominant motif, despite differences in MHC‐I allotypes between the cell lines, with preference for a hydrophobic leucine residue at position 3 and position Ω of peptides. DFT1 and DFT2 both present peptides derived from neural proteins, which reflects a shared cellular origin that could be exploited for vaccine design. These results suggest that polymorphisms in MHC‐I molecules between tumours and host can be ‘hidden’ by a common peptide motif, providing the potential for permissive passage of infectious cells and demonstrating complexity in mammalian histocompatibility barriers.

Optimization of the failure criterion in micro-Finite Element models of the mouse tibia for the non-invasive prediction of its failure load in preclinical applications

New treatments against osteoporosis require testing in animal models and the mouse tibia is among the most common studied anatomical sites. In vivo micro-Computed Tomography (microCT) based micro-Finite Element (microFE) models can be used for predicting the bone strength non-invasively, after proper validation against experiments. The aim of this study was to evaluate the ability of different microCT-based bone parameters and microFE models to predict tibial structural mechanical properties in compression. Twenty tibiae were scanned at 10.4 μm voxel size and subsequently tested in uniaxial compression at 0.03 mm/s until failure. Stiffness and failure load were measured from the load-displacement curves. Standard morphometric parameters were measured from the microCT images. The spatial distribution of bone mineral content (BMC) was evaluated by dividing the tibia into 40 regions. MicroFE models were generated by converting each microCT image into a voxel-based mesh with homogeneous isotropic material properties. Failure load was estimated by using different failure criteria, and the optimized parameters were selected by minimising the errors with respect to experimental measurements. Experimental and predicted stiffness were moderately correlated (R² = 0.65, error = 14% ± 8%). Normalized failure load was best predicted by microFE models (R² = 0.81, error = 9% ± 6%). Failure load was not correlated to the morphometric parameters and weakly correlated with some geometrical parameters (R² < 0.37). In conclusion, microFE models can improve the current estimation of the mouse tibia structural properties and in this study an optimal failure criterion has been defined. Since it is a non-invasive method, this approach can be applied longitudinally for evaluating temporal changes in the bone strength.

Heart rate as a marker of relapse during withdrawal of heart failure therapy in patients with recovered dilated cardiomyopathy: an analysis from TRED-HF

Introduction

In TRED-HF, 40% of patients with recovered dilated cardiomyopathy (DCM) relapsed in the short-term during phased withdrawal of drug therapy. Non-invasive markers of relapse may be used to monitor patients who wish a trial of therapy withdrawal and provide insights into the pathophysiological drivers of relapse.

Purpose

To investigate the relationship between changes in heart rate (HR) and relapse amongst patients with recovered DCM undergoing therapy withdrawal in TRED-HF.

Methods

Patients with recovered DCM were randomised to phased withdrawal of therapy or to continue therapy for 6 months. After 6 months of continued therapy, those in the control arm underwent withdrawal of therapy in a single arm crossover phase. HR was measured at each study visit. Mean HR and 95% confidence intervals (CI) were calculated at baseline, 45 days after baseline, 45 days prior to the end of the study or relapse and at the end of the study or relapse. Patients were stratified by treatment arm and the occurrence of the primary relapse end-point. Heart rate at follow-up was compared amongst patients who had therapy withdrawn and relapsed versus those who had therapy withdrawn and did not. ANCOVA was used to adjust for differences in HR at baseline between the two groups.

Results

Of 51 patients randomised, 26 were assigned to continue therapy and 25 to withdraw therapy. In the randomised and cross-over phases, 20 patients met the primary relapse end-point; one patient withdrew from the study and one patient completed follow-up in the control arm but did not enter the cross-over phase. Mean HR (standard deviation) at baseline and follow-up for (i) patients in the control arm was 69.9 (9.8) & 65.9 (9.1) respectively; (ii) for those who had therapy withdrawn and did not relapse was 64.6 (10.7) & 74.7 (10.4) respectively; and (iii) for those who had therapy withdrawn and relapsed was 68.3 (11.3) & 86.1 (11.8) respectively [all beats per minute]. The mean change in HR between the penultimate visit and the final visit for those who had therapy withdrawn and did not relapse was −2.4 (9.7) compared to 3.1 (15.5) for those who relapsed. After adjusting for differences in HR at baseline, the mean difference in HR measured at follow-up between patients who underwent therapy withdrawal and did, and did not relapse was 10.4bpm (95% CI 4.0–16.8; p=0.002) (Figure 1 & Table 1).

Conclusion(s)

A larger increase in HR may be a simple and effective marker of relapse for patients with recovered DCM who have insisted on a trial of therapy withdrawal. Whether HR control is crucial to the maintenance of remission amongst patients with improved cardiac function, or is simply a marker of deteriorating cardiac function, warrants further investigation.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): British Heart Foundation

The ecology and evolution of wildlife cancers: Applications for management and conservation

Ecological and evolutionary concepts have been widely adopted to understand host-pathogen dynamics, and more recently, integrated into wildlife disease management. Cancer is a ubiquitous disease that affects most metazoan species; however, the role of oncogenic phenomena in eco-evolutionary processes and its implications for wildlife management and conservation remains undeveloped. Despite the pervasive nature of cancer across taxa, our ability to detect its occurrence, progression and prevalence in wildlife populations is constrained due to logistic and diagnostic limitations, which suggests that most cancers in the wild are unreported and understudied. Nevertheless, an increasing number of virus-associated and directly transmissible cancers in terrestrial and aquatic environments have been detected. Furthermore, anthropogenic activities and sudden environmental changes are increasingly associated with cancer incidence in wildlife. This highlights the need to upscale surveillance efforts, collection of critical data and developing novel approaches for studying the emergence and evolution of cancers in the wild. Here, we discuss the relevance of malignant cells as important agents of selection and offer a holistic framework to understand the interplay of ecological, epidemiological and evolutionary dynamics of cancer in wildlife. We use a directly transmissible cancer (devil facial tumour disease) as a model system to reveal the potential evolutionary dynamics and broader ecological effects of cancer epidemics in wildlife. We provide further examples of tumour-host interactions and trade-offs that may lead to changes in life histories, and epidemiological and population dynamics. Within this framework, we explore immunological strategies at the individual level as well as transgenerational adaptations at the population level. Then, we highlight the need to integrate multiple disciplines to undertake comparative cancer research at the human-domestic-wildlife interface and their environments. Finally, we suggest strategies for screening cancer incidence in wildlife and discuss how to integrate ecological and evolutionary concepts in the management of current and future cancer epizootics.

Risks to healthcare workers following tracheal intubation of patients with COVID-19: a prospective international multicentre cohort study

Healthcare workers involved in aerosol‐generating procedures, such as tracheal intubation, may be at elevated risk of acquiring COVID‐19. However, the magnitude of this risk is unknown. We conducted a prospective international multicentre cohort study recruiting healthcare workers participating in tracheal intubation of patients with suspected or confirmed COVID‐19. Information on tracheal intubation episodes, personal protective equipment use and subsequent provider health status was collected via self‐reporting. The primary endpoint was the incidence of laboratory‐confirmed COVID‐19 diagnosis or new symptoms requiring self‐isolation or hospitalisation after a tracheal intubation episode. Cox regression analysis examined associations between the primary endpoint and healthcare worker characteristics, procedure‐related factors and personal protective equipment use. Between 23 March and 2 June 2020, 1718 healthcare workers from 503 hospitals in 17 countries reported 5148 tracheal intubation episodes. The overall incidence of the primary endpoint was 10.7% over a median (IQR [range]) follow‐up of 32 (18–48 [0–116]) days. The cumulative incidence within 7, 14 and 21 days of the first tracheal intubation episode was 3.6%, 6.1% and 8.5%, respectively. The risk of the primary endpoint varied by country and was higher in women, but was not associated with other factors. Around 1 in 10 healthcare workers involved in tracheal intubation of patients with suspected or confirmed COVID‐19 subsequently reported a COVID‐19 outcome. This has human resource implications for institutional capacity to deliver essential healthcare services, and wider societal implications for COVID‐19 transmission.

Pimavanserin: Potential Treatment For Dementia-Related Psychosis

Psychosis is common across dementia types with a prevalence of 20% to 70%. Currently, no pharmacologic treatment is approved for dementia-related psychosis. Atypical antipsychotics are frequently used to treat these disorders, despite significant safety concerns. Pimavanserin, a selective 5-HT2A inverse agonist/antagonist, was approved in the U.S. for treating hallucinations and delusions associated with Parkinson's disease psychosis (PDP). Patients in the pimavanserin group experienced a significant (p=0.001) improvement in Scale for the Assessment of Positive Symptoms - Parkinson's disease (SAPS-PD) scores vs. placebo. In a subgroup analysis of patients with cognitive impairment (MMSE score ≥21 but ≤24), the observed improvement on the SAPS-PD with pimavanserin (N=50) was also significant (p=0.002) and larger than in the overall study population without an adverse effect on cognition. In a Phase 2 study with pimavanserin in Alzheimer's disease psychosis, pimavanserin significantly (p=0.045) improved psychosis at Week 6 vs. placebo on the NPI-NH Psychosis Score (PS). In a prespecified subgroup of patients with a baseline NPI-NH PS ≥12, a substantively larger treatment effect (p=0.011) was observed vs. participants with NPI-NH PS <12. The results of these studies in cognitively impaired patients with PDP provided the scientific foundation for an ongoing study of pimavanserin for treating patients with dementia-related psychosis associated with the most common neurodegenerative disorders. The study uses a relapse-prevention design with the endpoint of time-to-relapse of psychosis to evaluate the long-term efficacy and safety of pimavanserin as a potential treatment for hallucinations and delusions of dementia-related psychosis.

P1932Predictors of DAPT use in patients beyond 1 year post myocardial infarction: Insights from the TIGRIS observational study

Background

International guidelines vary in their recommendations for dual antiplatelet therapy (DAPT) use beyond 1 year post-myocardial infarction (MI).

Purpose

To identify predictors of DAPT use in patients ≥1 year post-MI prior to the publication of the DAPT score and the 2017 European Society of Cardiology (ESC) guidelines for DAPT in coronary artery disease.

Methods

TIGRIS (NCT01866904) was a prospective, multi-center (369 centers in 25 countries), observational study of patients 1 to 3 years post-MI between June 2013 and November 2014. We performed a multivariable logistic regression analysis to identify independent predictors of DAPT use at 396 days post-MI (365 + 31 days overrun period to allow intended DAPT discontinuation at 1 year). Patients on oral anticoagulation were excluded.

Results

Of 8464 patients enrolled (mean age 66 years, women 24%, ST-elevation MI 53%), 40% were on DAPT at 396 days post-MI (Figure). In the subset of patients on DAPT at 396 days post-MI, aspirin was combined with clopidogrel in 84%, prasugrel in 12%, and other antiplatelet agents in 4%. DAPT use at 396 days post-MI was independently associated with geographic region, age, PCI for the index MI, and a history of multivessel disease or angina (Table). Several variables included in the DAPT score and ESC guideline recommendations (diabetes, second prior MI, hypertension, peripheral artery disease, heart failure, smoking, and renal insufficiency) were not independent predictors of DAPT use at 396 days.

Independent predictors of DAPT @396 days Variable at enrolment Patients Odds ratio (95% CI) P-value Region: Europe 3813 Reference group 0.01 North America 923 1.65 (0.56, 4.86) Latin America 1084 2.55 (1.19, 5.47) Asia and Australia 2644 3.01 (1.42, 6.36) Age <65 years 3274 1.15 (1.04, 1.28) 0.005 PCI for index MI 6925 2.08 (1.82, 2.38) <0.0001 Multi-vessel disease 5598 1.37 (1.24, 1.52) <0.0001 History of angina 829 1.46 (1.24, 1.71) <0.0001

DAPT use at 396 days post-MI by region

Conclusion

During the study period, DAPT use ≥1 year post-MI was prevalent and appeared to be influenced by regional practices. Further research is needed to determine whether the DAPT score and the 2017 ESC guidelines for dual antiplatelet therapy have changed long-term DAPT use practices.

Acknowledgement/Funding

AstraZeneca AB, Södertälje, Sweden

P5471Baseline characteristics, healthcare resource use and clinical outcomes of stable post-myocardial infarction patients with diabetes: insights from the global prospective TIGRIS study

Background

There is a growing prevalence of diabetes worldwide in patients in the general population, including those with prior myocardial infarction (MI).

Purpose

To describe the characteristics, health status, resource utilization and clinical adverse events of stable post-MI patients with diabetes.

Methods

The long-Term rIsk, clinical manaGement and healthcare Resource utilization of stable coronary artery dISease (TIGRIS) prospective observational study (NCT01866904) obtained data from 8985 stable patients 1–3 years post-MI from 369 centres in 25 countries, who provided diabetes status (no, yes, insulin-treated) and follow-up. Diabetes status, other patient characteristics, medications, medical history and healthcare resource utilization were recorded at enrolment. Health status was assessed at enrolment, 1 and 2 years by EQ-5D-3L and converted to an EQ-5D score. Deaths, cardiovascular (CV) events, bleeding events and related hospitalizations were recorded during 2 years of follow-up.

Results

Diabetes mellitus (DM) was prevalent at enrolment in 2966 (33%) patients of whom 872 (29%) were insulin-treated. Compared to patients without DM, those with DM had a higher mean body mass index (28.2 vs 26.6kg/m2) and heart rate (71 vs 67bpm), were more likely to have had ≥2 prior MIs (12% vs 10%), chronic kidney disease (10% vs 6%), peripheral artery disease (10% vs 5%), heart failure (15% vs 10%), anaemia (4% vs 2%), angina (12% vs 9%), stroke (6% vs 4%) and chronic obstructive pulmonary disease (9% vs 7%). Patients with DM reported more problems for each domain of the EQ-5D (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression), which resulted in a lower mean EQ-5D utility score at enrolment (0.83±0.22 for no-diabetes vs 0.86±0.19 for diabetes). Moreover, they also had higher CV hospitalization rates in the 6 months prior to enrolment (6.4% vs 5%). All these measures were more marked in insulin-dependent diabetics. The incidences of all-cause death, CV death and the composite of CV death, MI and stroke were all significantly higher in patients with DM, especially those on insulin (see Figure). For CV death, MI and stroke the 2-year risk ratios, compared to patients without DM, were 2.64 (P<0.001) and 1.48 (P<0.001) respectively for those with insulin-treated DM and non-insulin treated.

Figure 1

Conclusions

Within a global population of stable post-MI patients, those with DM (especially those on insulin) have poorer health status and EQ-5D utility score, higher hospitalization rates and worse clinical outcomes compared with those without DM. Thus, in cardiac clinics worldwide, patients with DM require particularly close attention.

Acknowledgement/Funding

The study was funded by AstraZeneca

Abstract 52: Inflammatory Biomarkers Correlate With Etiology in Childhood Arterial Ischemic Stroke

Introduction: Etiologies of childhood arterial ischemic stroke (AIS) are heterogeneous, yet most cases fall into one of three subtypes: arteriopathic, cardioembolic, or idiopathic. Circulating inflammatory mediators could play a role in the pathogenesis of each subtype, whether through inflammatory injury to arterial or cardiac endothelium, or by promoting thrombosis.

Hypothesis: Patterns of post-stroke serum inflammation in children will differ by etiologic subtype.

Methods: From the “Vascular effects of Infection in Pediatric Stoke” (VIPS) study cohort (355 cases of AIS, ages 29 days through 18 years), we selected cases centrally classified as arteriopathic (N=119), spontaneous cardioembolic (N=58; excluding peri-procedural cardioembolic AIS), or idiopathic (N=82). We used Luminex assays to measure serum concentrations (pg/mL) of 20 inflammatory biomarkers selected for their correlation with adult AIS or arteriopathy in other settings. We compared analyte concentrations across the three etiologic subtypes in unadjusted and adjusted analyses.

Results: Serum samples were collected at a median of 5.5 days post-stroke (IQR 3, 10 days). Compared to children with idiopathic AIS, those with cardioembolic AIS had higher levels of four analytes (IL-6, IL-8, IL-10, IP-10), even after adjustment for age, sex, infarct volume, and other potential confounders (Table). Children with arteriopathic AIS, on the other hand, had higher levels of two analytes (IL-10, IP-10), and lower levels of another two (fractalkine, MCP-1).

Conclusion: Patterns of post-AIS serum inflammation differ by stroke subtype in children, and may provide clues to stroke pathogenesis. We will perform network analyses using unsupervised machine learning approaches to elucidate these patterns further.

Development of a high-resolution infrared thermographic imaging method as a diagnostic tool for acute undifferentiated limp in young children

Acute limp is a common presenting condition in the paediatric emergency department. There are a number of causes of acute limp that include traumatic injury, infection and malignancy. These causes in young children are not easily distinguished. In this pilot study, an infrared thermographic imaging technique to diagnose acute undifferentiated limp in young children was developed. Following required ethics approval, 30 children (mean age = 5.2 years, standard deviation = 3.3 years) were recruited. The exposed lower limbs of participants were imaged using a high-resolution thermal camera. Using predefined regions of interest (ROI), any skin surface temperature difference between the healthy and affected legs was statistically analysed, with the aim of identifying limp. In all examined ROIs, the median skin surface temperature for the affected limb was higher than that of the healthy limb. The small sample size recruited for each group, however, meant that the statistical tests of significant difference need to be interpreted in this context. Thermal imaging showed potential in helping with the diagnosis of acute limp in children. Repeating a similar study with a larger sample size will be beneficial to establish reproducibility of the results. Graphical abstract A young child with an acute undifferentiated limp undergoes thermal imaging and the follow on image analysis assists the limp diagnosis.

Amphibian breeding phenology and reproductive outcome: an examination using terrestrial and aquatic sampling

Worldwide amphibian declines highlight the need for programs that monitor species presence and track population trends. We sampled larval amphibians with a box trap at 3-week intervals for 23 months in eight wetlands, and concurrently trapped adults and juveniles with drift fences, to examine spatiotemporal patterns of tadpole occurrence; explore relationships between breeding effort, tadpole abundance, and recruitment; and compare the efficacy of both methods in detecting species presence and reproductive outcome. Intermittent detection of species within and among wetlands suggested high mortality, followed by deposition of new eggs and tadpole cohorts. Breeding effort, tadpole abundance, and juvenile recruitment were generally not correlated. The reasons for this may include differential bias in detecting species or life stages between methods and high incidence of egg or tadpole mortality. Drift fences detected more species than box traps, but each provided insights regarding amphibian presence and recruitment. Our results illustrate shortfalls in the ability of infrequent aquatic sampling to detect local species richness of larval amphibians, as occurrence of many species is spatially and temporally variable. We also show the importance of using different sampling methods to detect species’ presence, as well as difficulties associated with both methods in tracking breeding effort, tadpole occurrence, or reproductive outcome.

Correction: Temporal Patterns of Influenza A and B in Tropical and Temperate Countries: What Are the Lessons for Influenza Vaccination?

[This corrects the article DOI: 10.1371/journal.pone.0152310.].

Pelvic Artery Embolization in the Management of Obstetrical Hemorrhage: Predictive Factors for Clinical Outcomes

PURPOSE

To evaluate clinical outcomes of pelvic artery embolization (PAE) for treatment of obstetric hemorrhage, and determine the predictive factors associated with failure.

MATERIALS AND METHODS

This retrospective study included all consecutive patients who underwent PAE for obstetric hemorrhage (not only in the post-partum setting), between January 2003 and January 2013 at three tertiary care centers. Medical records and imaging were reviewed to identify the study population and collect data on patient characteristics, PAE characteristics, and outcomes. Multiple parameters were compared between the failed and successful PAE groups, and univariate analysis was performed to determine the predictive factors for PAE failure.

RESULTS

A total of 74 PAE procedures were performed in 68 patients. Primary clinical success rate was 78%. On univariate analysis, three factors were associated with PAE failure: hemodynamic instability (p < 0.022), hemoglobin level <95 g/dL (p < 0.024), and disseminated intravascular coagulation (DIC) (p < 0.046). Other factors, including maternal characteristics, antecedent history, angiographic finding, embolic agent, operator experience, procedure done after hours, and unilateral versus bilateral embolization, did not show any statistically significant association with PAE failure. Only one major complication was encountered, which was fetal demise in a pregnant patient with a uterine arteriovenous malformations. Out of the 68 patients, there were 61 total pregnancies at follow-up.

CONCLUSION

PAE is an effective treatment for obstetric hemorrhage, with a low complication rate, and preserves fertility. Factors significantly associated with PAE failure include hemodynamic instability, hemoglobin level <95 g/dL, and DIC.

The use of telemedicine in burn care: development of a mobile system for TBSA documentation and remote assessment

The requirements for accurate documentation within the process of burn assessment have increased dramatically over the years. TBSA (total body surface area) and burn depth are commonly determined by visual inspection, especially in the emergency or acute care setting. However, inexperience often results in incorrect estimation of these factors. In 2001, BurnCase 3D was initiated in order to develop a tool for objective burn assessment and documentation on mobile devices (Apple iPhoneTM). The centerpiece is a 3D model representing the actual patient. At two international burn meetings, a survey containing three pictures of patients was conducted and this data was collected. A patient-specific 3D model adapted to the height and weight of the real patient was created and the digital picture was superimposed in the computer system. The burns were transferred to the model and the TBSA in % was calculated by the software BurnCase 3D. The preferred methods of the 80 respondents for burn extent estimation were: the Rule of Nines (38%), the Rule of Palm (37%) and the Lund-Browder chart (18%). Analysis showed very high deviations of TBSA within the participants, even among the group of experts. In comparison to a computer-aided method we found massive overestimation of up to 230%. The use of BurnCase 3D could have a true impact on the quality of treatment in burns. In the acute care setting for burn injuries, telemedicine has great potential to help guide decisions regarding triage and transfer based on TBSA, burn depth, patient age and injury mechanism.

Smartphones and burn size estimation: "Rapid Burn Assessor"

Estimation of the total body surface area burned (%TBSA) following a burn injury is used in determining whether to transfer the patient to a burn center and the required fluid resuscitation volumes. Unfortunately, the commonly applied methods of estimation have revealed inaccuracies, which are mostly related to human error. To calculate the %TBSA (quotient), it is necessary to divide the burned surface area (Burned BSA) (numerator in cm2) by the total body surface area (Total BSA) (denominator in cm2). By using everyday objects (eg. credit cards, smartphones) with well-defined surface areas as reference for estimations of Burned BSA on the one hand and established formulas for Total BSA calculation on the other (eg. Mosteller), we propose an approximation method to assess %TBSA more accurately than the established methods. To facilitate distribution, and respective user feedback, we have developed a smartphone app integrating all of the above parameters, available on popular mobile device platforms. This method represents a simple and ready-to-use clinical decision support system which addresses common errors associated with estimations of Burned BSA (=numerator). Following validation and respective user feedback, it could be deployed for testing in future clinical trials. This study has a level of evidence of IV and is a brief report based on clinical observation, which points to further study.

United Kingdom Myeloma Forum (UKMF) position statement on the use of bendamustine in myeloma

Bendamustine is a unique bifunctional alkylating agent with promising activity in myeloma. Despite the increasing number of studies demonstrating its efficacy in both the upfront and relapse settings, including patients with renal insufficiency, the optimal use of bendamustine, in terms of dosage, schedule and combination with other agents, has yet to be defined. It is currently licensed for use as frontline treatment with prednisolone for patients with myeloma who are unsuitable for transplantation and who are contraindicated for thalidomide and bortezomib. Studies in relapsed/refractory patients are currently ongoing with other combinations. Given the increasing data to date, the UK Myeloma Forum believes that bendamustine with steroids alone or in combination with a novel agent could be considered for patients with multiply relapsed myeloma. This document provides guidance for the use of bendamustine for patients with myeloma until the results of definitive studies are available.

Abstract P3-06-09: Test of association between Ki67 index of early breast cancer and local relapse after adjuvant hypofractionated radiotherapy

Introduction: There is a strong inverse association between the proliferation indices of early- and late-responding normal tissues and their sensitivity to radiotherapy fraction size. The aim of this study is to test for association between Ki67 index and the fractionation sensitivity of breast cancer. The hypothesis is that tumours with high Ki67 indices are relatively insensitive to fraction size and be over-represented in tumours relapsing after hypofractionated, radiotherapy.

Methods: Between 1986 and 2003, the START pilot and START A trials tested 2 test dose levels of a 13-fraction regimen (3.0 or 3.3 Gy & 3.0 or 3.2 Gy fractions, respectively) in 5 weeks against 25 fractions of 2.0 Gy following primary surgery for early breast cancer. Primary tumour blocks of patients with local tumour relapse were collected for immunohistochemistry (IHC) for Ki67 (manual counting in whole sections), HER2, ER & PR (Allred quick scores in tissue sections). Ki67 was assumed to be log normally distributed with a standard deviation of 0.5–0.9. Assuming evaluable blocks for 240 patients, a standardised detectable difference of 0.45 (90%+ power, 5% significance level) corresponded to a detectable difference in geometric means of 5–10%.

Results: From a total of 3646 patients entered into the START pilot and START A trials, 261 local tumour relapses were recorded at a median follow up of 8.4 years (range 0.9–17.5) and 7.2 (range 0.7–11.9) years respectively. Blocks from 213 patients were recovered, of which 176 were evaluable by IHC. There was no significant difference in proliferation between tumours relapsing after conventional and hypofractionated radiotherapy, with mean Ki67 scores of 7.63 (95%CI: 5.06–11.5) and 5.33 (95CI%: 3.86–7.35), respectively. Mean Ki67 scores in 48 primary triple negative tumours (TNT) that relapsed locally were 15.74 (95%CI: 8.53–29.06) after conventional and 7.52 (95%CI: 3.51–16.1) after hypofractionated radiotherapy, but TNT were equally represented (28%) in both groups.

Conclusion: An association between proliferative indices and fractionation sensitivity in breast tumours has not been demonstrated. If confirmed, it suggests that genetic and epigenetic features unrelated to proliferation are sources of inter-tumour variation in fractionation sensitivity.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-06-09.