Fully automated quantification of LV regional wall motion from echocardiograms to detect myocardial infarction

Funding Acknowledgements

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

Background

Myocardial wall motion analysis from echocardiography allows precise assessment of cardiac contractile function. Strain, which assesses myocardial deformation, has been shown to enable earlier detection of myocardial disease [1]. Current analysis software packages [2] use semi-automated methods to compute strain, which frequently require manual endocardial delineation and iterative contour adjustment based on tracking results, respectively, causing significant variability.

Purpose

We present a fully automated pipeline for tracking left ventricular (LV) wall motion to quantify global and segmental longitudinal strain from 2D echocardiograms, and go on to validate the pipeline with an openly available myocardial infarction (MI) dataset.

Methods

We applied our existing deep learning-based automated contouring method [3] to delineate the endocardial border in the A4C, A2C and A3C views and combined this with spline-based elastic image registration to track LV motion through time. We sampled points from a region of interest initiated from the endocardial border at the end-diastolic (ED) frame, and tracked subsequent motion by recomputing updated positions of all sample points based on each frame‘s displacement field, enabling us to both track the myocardium throughout the cardiac cycle and calculate longitudinal strain relative to the ED frame. The automated endocardial contour was used to regularise the process. The pipeline was independently tested on the HMC-QU dataset [4] which was downloaded from Kaggle and consists of a single cardiac cycle from the A4C view from 160 patients who were diagnosed with an acute MI and underwent echocardiography either prior to percutaneous coronary intervention or within 24 hours of undergoing the procedure; the dataset includes the labels of ED and end-systolic (ES) frames, as well as the presence of an MI in 6 segments excluding the apical cap (Fig 1a), as determined by the consensus of cardiologists from HMC Hospital in Qatar. The Wilcoxon signed-rank test was used to compare peak strain between the MI and non-MI segments; ROC curves were computed to compare the performance of the automatically derived peak longitudinal strain against the MI labels.

Results

Fig 1b shows ROC curves of peak segmental longitudinal strain for detecting MI, with the best performance in the mid-anterolateral segment (AUC 0.84), and a lower performance for basal segments than mid and apical segments, consistent with known variation in clinical practice [5]. Fig 2 shows that peak longitudinal strain computed from our pipeline was statistically significantly more positive in segments with an MI.

Conclusions

We present a fully automated pipeline for calculating segmental strain across a cardiac cycle to identify infarcted segments without any observer variability. Clinical application of this method has the potential to identify and monitor regional myocardial function and benefit patient management. Abstract Figure. Fig1. ROC of peak longitudinal strains  Abstract Figure. Fig2.Boxplot of peak longitudinal strain

The association between incident vertebral deformities, health-related quality of life and functional impairment: a 10.7-year cohort study

We aimed to describe longitudinal changes in health-related quality of life (HRQoL) measures associated with incident vertebral deformities (VDs) over 10.7 years. Incident VDs are associated with clinically significant functional impairment in men, and reduction in overall HRQoL in older women. Increasing severity and number of incident VDs are associated with clinically meaningful functional impairment in men, but not women.

INTRODUCTION

To describe associations between incident VD and changes in HRQoL and functional ability in older adults over 10.7 years.

METHODS

Participants (n = 780) underwent whole-body dual-energy X-ray absorptiometry (DXA) scans at baseline, 2.5, 5.1 and 10.7 years later. VD was defined as ≥ 25% reduction in anterior height relative to posterior height of vertebrae from T4 to L4. An incident VD was defined as a new VD at any follow-up visit. Assessment of Quality of Life (AQoL-4D) questionnaire and Health Assessment Questionnaire-Disability Index (HAQ-DI) were used to assess HRQoL and functional impairment. Changes in AQoL and HAQ-DI associated with incident VD were analysed using multilevel mixed-effects linear regression. Log binomial regression was used to examine clinically relevant changes and effects of severity and number of VD.

RESULTS

The incidence of VD was 37% over 10.7 years. In women, incident VDs were associated with annual reduction in AQoL utility score (β = -0.005, 95% CI -0.008 to -0.002). Men had increased risk of clinically significant reduction in HAQ-DI (IRR = 1.76, 95% CI 1.07-2.89). Men had increased risk of clinically important functional impairment with increasing severity (IRR 1.76, 95% CI 1.04-2.95 for mild vs IRR 1.98, 95% CI 1.13-3.47 for moderate to severe VD) as well as number of incident VD (IRR 1.85, 95% CI 1.17-2.93 for one vs IRR 1.88, 95% CI 0.94-3.78 for ≥ 2 VDs). Such associations were not observed in women.

CONCLUSIONS

Incident VDs are associated with clinically significant functional impairment in men, and reduction in overall HRQoL in older women. Increasing severity and number of incident VDs are associated with clinically meaningful functional impairment in men, but not women.

Patients presenting with acute coronary syndromes have unreported coronary artery calcium on historical CT imaging

Introduction

Ischaemic heart disease (IHD) remains the leading cause of mortality globally1. The presence and extent of coronary artery calcification (CAC) is a strong predictor of cardiovascular events, and CAC scoring has been shown to be more predictive of cardiovascular events than other traditional risk assessment scores2.

Incidental coronary calcification can be detected and quantified on non-gated CT chest scans covering the heart in the field of view3. This finding is typically not reported4 and hence an opportunity to optimise cardiovascular risk assessment and treatment is missed.

Purpose

We sought to investigate whether patients presenting to our centre with an acute coronary syndrome (ACS) event had historical CT imaging demonstrating coronary artery calcification.

Methods

We retrospectively reviewed case records for all patients referred to our centre for an invasive coronary angiogram following their first known admission with an ACS event. ACS were defined according to contemporary guidelines from the European Society of Cardiology. We reviewed a 3 month period prior to the COVID-19 pandemic (01/01/2019–31/03/2019). The national imaging database was interrogated to identify previous CT imaging that includes the heart in the field of view. The presence of coronary calcification was confirmed and quantified using an ordinal scoring method previously described3. The clinical radiology reports for the scans were reviewed to determine the frequency of CAC being reported.

Demographic information was collected from our electronic patient record including the presence of risk factors for IHD. Prescribed medication prior to admission was also recorded using the on-admission medicines reconciliation documented in the electronic patient record.

Results

385 patients with first presentation of ACS were identified. 75 (19%) had a prior non-gated CT chest imaging. The most common indication for CT was for investigation of possible malignancy. The mean interval from CT imaging to ACS admission was 36 months.

CAC was present on 67 (89%) scans. The mean ordinal score was 4.04, corresponding to moderate CAC. The distribution of CAC by coronary artery revealed the majority of disease to involve the left anterior descending artery (Table 1). Only 12/67 (18%) of clinical radiology reports mentioned coronary calcification (Figure 1).

Patients with CAC frequently had additional risk factors for IHD. Despite this only 42% were prescribed antiplatelet therapy, and only 45% prescribed a statin.

Conclusions

A significant proportion of ACS admissions have evidence of CAC on historical CT scans. This finding is often not reported and the majority of patients with demonstrated coronary artery disease are not prescribed appropriate preventative therapies. Systematic reporting of this finding may have a significant impact on the prevention of acute cardiovascular events.

Funding Acknowledgement

Type of funding sources: None. Table 1

Machine learning for detection of stenoses and aneurysms: application in a physiologically realistic virtual patient database

This study presents an application of machine learning (ML) methods for detecting the presence of stenoses and aneurysms in the human arterial system. Four major forms of arterial disease-carotid artery stenosis (CAS), subclavian artery stenosis (SAS), peripheral arterial disease (PAD), and abdominal aortic aneurysms (AAA)-are considered. The ML methods are trained and tested on a physiologically realistic virtual patient database (VPD) containing 28,868 healthy subjects, adapted from the authors previous work and augmented to include disease. It is found that the tree-based methods of Random Forest and Gradient Boosting outperform other approaches. The performance of ML methods is quantified through the [Formula: see text] score and computation of sensitivities and specificities. When using six haemodynamic measurements (pressure in the common carotid, brachial, and radial arteries; and flow-rate in the common carotid, brachial, and femoral arteries), it is found that maximum [Formula: see text] scores larger than 0.9 are achieved for CAS and PAD, larger than 0.85 for SAS, and larger than 0.98 for both low- and high-severity AAAs. Corresponding sensitivities and specificities are larger than 90% for CAS and PAD, larger than 85% for SAS, and larger than 98% for both low- and high-severity AAAs. When reducing the number of measurements, performance is degraded by less than 5% when three measurements are used, and less than 10% when only two measurements are used for classification. For AAA, it is shown that [Formula: see text] scores larger than 0.85 and corresponding sensitivities and specificities larger than 85% are achievable when using only a single measurement. The results are encouraging to pursue AAA monitoring and screening through wearable devices which can reliably measure pressure or flow-rates.

Introduction - Validation of tests for OIE-listed diseases as fit-for-purpose in a world of evolving diagnostic technologies

The World Organisation for Animal Health (OIE) has made leading contributions to the discipline of test validation science by providing standards and guidelines that inform the test validation process in terrestrial and aquatic animals. The OIE Manual of Diagnostic Tests and Vaccines for Terrestrial Animals, and the Manual of Diagnostic Tests for Aquatic Animals describe the test validation pathway in the context of fitness for purpose, elaborate on the importance of diagnostic sensitivity (DSe) and specificity (DSp) as measures of test accuracy, and designate additional factors (e.g. test cost, laboratory throughput capacity and rapidity of test results) that influence choices of a single test over others or the inclusion of a new test in a diagnostic process that includes multiple tests. This paper provides examples of each of the six main testing purposes listed in the Terrestrial Manual and describes additional metrics such as ruggedness and robustness that should be included in the validation of point-of-care tests. Challenges associated with new diagnostic technologies and platforms are described. Validated tests with estimates of DSe and DSp are needed to measure confidence in test results for OIE-listed diseases, to facilitate risk assessments related to animal movement, to estimate true prevalence, and for certification of disease freedom and use in epidemiological (risk factor) studies.

Bayesian latent class analysis when the reference test is imperfect

Latent class analysis (LCA) has allowed epidemiologists to overcome the practical constraints faced by traditional diagnostic test evaluation methods, which require both a gold standard diagnostic test and ample numbers of appropriate reference samples. Over the past four decades, LCA methods have expanded to allow epidemiologists to evaluate diagnostic tests and estimate true prevalence using imperfect tests over a variety of complex data structures and scenarios, including during the emergence of novel infectious diseases. The objective of this review is to provide an overview of recent developments in LCA methods, as well as a practical guide to applying Bayesian LCA (BLCA) to the evaluation of diagnostic tests. Before conducting a BLCA, the suitability of BLCA for the pathogen of interest, the availability of appropriate samples, the number of diagnostic tests, and the structure of the data should be carefully considered. While formulating the model, the model's structure and specification of informative priors will affect the likelihood that useful inferences can be drawn. With the growing need for advanced analytical methods to evaluate diagnostic tests for newly emerging diseases, LCA is a promising field of research for both the veterinary and medical disciplines.

Associations of dietary patterns with bone density and fractures in adults: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Although nutrition is important to bone health, the impact of different dietary patterns on bone density and fracture is unclear. The aim of this study was to synthesise conflicting evidence from observational studies to determine associations of empirically derived dietary patterns with bone density and fracture in healthy adults.

METHOD

A systematic review (PROSPERO CRD42017071676) with meta-analysis where possible (for hip fracture) and otherwise with best-evidence synthesis.

RESULTS

Twenty-one studies were included in the best-evidence synthesis and four in the meta-analysis. Meta-analysis demonstrated a protective association between 'healthy' pattern score and hip fracture (risk ratio 0.73; 95% confidence interval: 0.56, 0.96; I2 = 95%) for highest compared to lowest 'healthy' pattern score category. In best-evidence synthesis, there was conflicting evidence for associations of both pattern scores with bone density at all sites and total fractures and for 'Western' score and hip fracture. No study reported detrimental effects of 'healthy' patterns, or beneficial effects of 'Western' patterns.

DISCUSSION

The results suggest that general practitioners promoting a 'healthy' dietary pattern is, at worst, unlikely to be detrimental for bone health and, at best, may reduce hip fracture.

POS0280 ASSOCIATION OF COMPLEMENTARY AND ALTERNATIVE MEDICINE USE WITH KNEE SYMPTOMS AND KNEE STRUCTURAL CHANGES OVER 2.6 YEARS: A POPULATION-BASED COHORT STUDY OF TASMANIAN OLDER ADULTS

Background:

There is increasing use of complementary and alternative medicines (CAMs) alone or as an adjuvant therapy to conventional palliative medicines.1 However, there remains clinical uncertainty about the benefit of CAMs in the management of osteoarthritis in older population.

Objectives:

To describe the association between CAM use (alone or in combination with conventional analgesics) with knee symptoms and structural changes amongst a representative sample of Tasmanian older adults.

Methods:

A total of 1,099 participants were selected from the Tasmania Older Adult Cohort Study (TASOAC), an ongoing prospective population-based study. Exposure to CAM and conventional medications was classified into four categories according to the national drug code directory: 2 CAM only, conventional analgesics only, both CAM and conventional analgesics, and neither CAMs nor conventional analgesics. Knee pain was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and a 1.5-T MRI of the right knee was performed at baseline and follow-up (around 2.6 years). Longitudinal associations were assessed using mixed effect linear models.

Results:

At baseline, participants‘ mean age was 63, 86.5% (n=951) reported any medication use. The prevalence of CAM use was 35.0% and of conventional analgesics was 58.6%. Over follow-up, the analgesic only group had a significant increase in WOMAC pain, function, and stiffness scores compared to those who took neither CAMs nor conventional analgesics. There was a statistically significant femoral cartilage volume loss across all four groups, and no statistical difference was found between participants who takes both CAMs and analgesics group and the reference group, but participant in the CAM only or the analgesics only groups loss statistically significant more femoral cartilage volume than the reference group (Table 1).

Table 1.

Association of change in clinical knee symptoms and knee structural changes over 2.6 years with different medications groups.

Mean change for reference group*Change for each category, coefficient (95% confident intervals)CAMsBothAnalgesicsReference group*No. of participants327128257387327WOMAC pain (5-50)-0.95 (-1.42, -0.48)0.04 (-0.85, 0.93)0.32 (-0.4, 1.04)0.78 (0.13, 1.43)RefWOMAC function (17-170)-3.09 (-4.52, -1.67)1.02 (-1.7, 3.73)1.39 (-0.81, 3.59)2.32 (0.33, 4.31)RefWOMAC stiffness (2-20)-0.39 (-0.62, -0.17)0.15 (-0.28, 0.58)0.35 (0, 0.7)0.40 (0.09, 0.72)RefFemoral cartilage volume (mL)-187.98 (-228.79, -147.18)-113.81 (-192.60, -35.03)-1.92 (-65.00, 61.17)-127.19 (-186.31, -68.06)Ref

*Reference group=participants taken neither CAMs nor conventional analgesics

Conclusion:

CAM use alone or in combination with conventional analgesics may associate with slower progression of knee pain. Conclusive evidence on the longitudinal benefits of CAM in the management of osteoarthritis among older adults warrants more studies.

References:

[1]Steel A, McIntyre E, Harnett J, et al. Complementary medicine use in the Australian population: Results of a nationally-representative cross-sectional survey. Sci Rep 2018;8:17325.

[2]National Center for Health Statistics. Long-term Care Drug Database System: Drugs by NDC Class Code, Drug Code and Name 2007 Available from: https://www.cdc.gov/nchs/data/nnhsd/DrugsbyNDCClass3.pdf [accessed date: 2020 23 December].

The data were fitted using mixed effect linear models, which were constructed by entering baseline medication group, phase, the interaction between medication group and phase, covariates (baseline age, sex, body mass index [BMI], baseline value of outcome), the interaction between the covariates and phase, random intercept, and random slope on phase (time).

Disclosure of Interests:

None declared

OP0196 CIRCULATING LEVEL OF IL-6 IS ASSOCIATED WITH 10.7-YEAR KNEE CARTILAGE VOLUME LOSS AND WORSE PAIN TRAJECTORY

Background:

There is growing evidence that inflammation plays a critical role in osteoarthritis (OA) progression and its symptoms evolution. OA pain is heterogeneous and there are distinct subgroups within OA pain patients. Recently, we identified three homogeneous subgroups following distinct pain trajectories in which metabolic mechanism may be involved. Whether circulating inflammatory markers are associated with long-term knee structural changes on MRI, and whether the association between inflammatory markers and the trajectories we identified differs remain to be clarified.

Objectives:

To examine whether inflammatory markers are associated with 10.7-year knee structural changes including knee cartilage volume (CV) and bone marrow lesions (BMLs), and to assess the associations between inflammatory markers and different pain trajectories.

Methods:

This study was conducted as part of a population-based older adult (mean age 63 years, 51% of females) cohort study with 1,099, 875, 768 and 563 participants attending at baseline, and 2.6-, 5.1- and 10.7-year follow-ups. Circulating levels of interleukin (IL)-6, tumour necrosis factor alpha (TNF-α) and high sensitivity C-reactive protein (CRP) were measured at baseline in 193 randomly selected participants. T1-weighted or T2-weighted MRI of the right knee was performed to measure CV and BMLs at baseline and 10.7-year. X-ray was performed to assess radiographic knee osteoarthritis (ROA). The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain questionnaire was used to measure knee pain at all four visits. Data on demographic, psychological, lifestyle and comorbidities were also collected. Pain trajectories was previously identified using the group-based trajectory modelling. Linear, log-binomial and multi-nominal logistic regression modellings were used for the analyses.

Results:

IL-6 was associated with both medial and lateral tibial CV loss (Medial: β=-0.51% per log pg/ml, 95%CI -0.88 to -0.15; Lateral: β=-0.34% per log pg/ml, 95%CI -0.64 to -0.04) after adjusting for age, sex, body mass index, physical activity, comorbidities, and ROA. TNF-α was not associated with either medial or lateral CV loss, but CRP was positively associated with medial tibial CV loss (Medial: β=0.27% per log mg/L, 95%CI 0.04 to 0.49), not lateral CV loss. No inflammatory markers were found to associate with medial and lateral BML size increase. Of 169 participants who had complete data at baseline, 54%, 35% and 11% of participants fell into ‘Minimal pain’, ‘Mild pain’ and ‘Moderate pain’ trajectory group, respectively. In multivariable analysis, IL-6 was associated with an increased risk of being a ‘Moderate pain’ trajectory (relative risk ratio [RRR]: 4.03, 95%CI 1.34 to 12.13) in comparison with ‘Minimal pain’ trajectory group. There was no significant association of TNF-α and CRP with trajectory groups.

Conclusion:

IL-6 was associated with both medial and lateral tibial CV loss (Medial: β=-0.51% per log ml/pg, 95%CI -0.88 to -0.15; Lateral: β=-0.34% per log ml/pg, 95%CI -0.64 to -0.04) after adjusting for age, sex, body mass index, physical activity, comorbidities, and ROA. TNF-α was not associated with either medial or lateral CV loss, but CRP was positively associated with medial tibial CV loss (Medial: β=0.27% per log ml/pg, 95%CI 0.04 to 0.49), not lateral CV loss. No inflammatory markers were found to associate with medial and lateral BML size increase. Of 169 participants who had complete data at baseline, 54%, 35% and 11% of participants fell into ‘Minimal pain’, ‘Mild pain’ and ‘Moderate pain’ trajectory group, respectively. In multivariable analysis, IL-6 was associated with an increased risk of being a ‘Moderate pain’ trajectory (relative risk ratio [RRR]: 4.03, 95%CI 1.34 to 12.13) in comparison with ‘Minimal pain’ trajectory group. There was no significant association of TNF-α and CRP with trajectory groups.

Disclosure of Interests:

None declared

POS1103 SLEEP DISTURBANCE AND BONE MINERAL DENSITY, RISK OF FALLS AND FRACTURE: RESULTS FROM A 10.7-YEAR PROSPECTIVE COHORT STUDY

Background:

Sleep problems are common in the general population and have been reported to adversely affect bone health and increase risk of falls and fracture. However, no study has investigated whether an increased risk of fracture is attributable to sleep-related low bone mineral density (BMD) and/or an increased risk of falls.

Objectives:

This study, therefore, sought to describe the associations of sleep disturbance with BMD, risk of falls and fractures.

Methods:

The analyses were performed in a population-based prospective cohort study with 1,099 participants (aged 50–80 years) enrolled at baseline, and 875, 768 and 563 participants traced at a mean follow-up of 2.6, 5.1 and 10.7 years, respectively. At each visit, self-reported sleep disturbance was recorded. BMD (by DXA), falls risk and fracture were measured at each visit. The short-form Physiological Profile Assessment was used to measure falls risk expressed as Z-score. Fractures were self-reported. Mixed-effects model and generalised estimating equations were used for the analyses.

Results:

In multivariable analysis, there was a dose-response relationship between extent of sleep disturbance and falls risk score with the strongest association in those reporting the worst sleep disturbance (β=0.15/unit; 95%CI 0.02-0.28). The worst sleep disturbance was associated with an increased risk of any (relative risk [RR] 1.30/unit; 95%CI 1.01-1.67) and vertebral fracture (RR 2.41/unit; 95%CI 1.00-5.80) compared with those reporting no interrupted sleep. This was independent of covariates, hip BMD and falls risk. There was no statistically significant association between sleep disturbance and BMD at hip, spine or total body.

Conclusion:

Sleep disturbance was independently associated with a greater falls risk score and an increased risk of fractures, suggesting that correcting sleep disturbance has the potential to reduce both falls risk and fractures.

Disclosure of Interests:

None declared.

POS0276 EFFICACY OF KRILL OIL IN THE TREATMENT OF KNEE OSTEOARTHRITIS: A 24-WEEK MULTICENTRE RANDOMISED DOUBLE-BLIND CONTROLLED TRIAL

Background:

Elevated levels of systemic inflammation are common in people with osteoarthritis and predict both pain and structural outcomes. Krill oil has anti-inflammatory properties and reduces severity of inflammatory arthritis in mice by 50% compared to controls.1 In humans, krill oil reduced knee pain and function in two short, moderate quality randomised controlled trials (RCTs) in people with osteoarthritis. However, evidence from longer trials with imaging data is lacking.

Objectives:

The aim of this study was to compare the efficacy of krill oil (2g / day) vs. placebo for treating knee pain in patient with clinical knee osteoarthritis who have significant knee pain and effusion-synovitis.

Methods:

KARAOKE was a 24-week multicentre, randomised, double-blind, placebo-controlled trial conducted at five Australian sites. Participants aged ≥40 years with symptomatic knee OA (according to ACR criteria), significant knee pain (pain score ≥40mm on a 100mm visual analogue scale [VAS]), and effusion-synovitis present on MRI (grade ≥1 according to modified Whole-Organ Magnetic Resonance Imaging Score (WORMS) scoring) were eligible. The study protocol has been published previously.2

Participants were randomised to receive 2g/day of krill oil, (350 mg/g omega-3 content, 12 mg/g total omega-6 content) or inert placebo (vegetable oil, no EPA or DHA, <5 mg/g (0.05%) other omega-3s).

The primary outcome was absolute change in knee pain assessed using a VAS [0-100mm] after 24 weeks. Secondary outcomes were: change in knee pain and function assessed using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score [0-500mm]), change in back and hand pain assessed using a VAS [0-100mm], change in lower limb leg strength assessed using a dynamometer, and change in blood parameters (including CRP, triglycerides, fasting glucose and total, HDL, LDL cholesterol), after 24 weeks.

Linear mixed-models were used, using patient identification as random intercepts and trial centre and treatment month as random effect to adjust for correlated data within trial centres and repeated measures and to allow different treatment effects among patients over time, respectively.

Results:

262 participants were randomised (mean age 61.5 years, 53% females) to receive krill oil (n=130) or placebo (n=132). A total of 85% completed the trial.

Knee pain improved in both groups over 24 weeks, but with no between-group difference (krill oil, -20.1mm; placebo, -19.3mm, p=0.81). Secondary outcomes: knee pain and function score improved in both groups, but with no between-group difference (WOMAC pain: krill oil, -86.7; placebo, -82.5mm, p=0.81; WOMAC function: krill oil, -245.3; placebo, -184.3, p=0.14 at 24 weeks). The same applies for hand pain and back pain. No significant changes were seen in leg strength or any of the blood parameters at 24 weeks). Incidence of one or more adverse events was 50% in the krill oil group (n=66) and 55% in the placebo group (n=71). There were 8 serious adverse events in the krill oil group 6 in the placebo group, all considered unrelated to treatment.

Conclusion:

Krill oil was safe and well tolerated, but did not significantly reduce knee pain in patients with clinical knee osteoarthritis, significant knee pain and effusion-synovitis after 24 weeks compared to placebo. These findings do not support use of krill oil for alleviating knee pain in clinical knee osteoarthritis.

References:

[1]Ierna M, et al. BMC Musculoskelet Disord 2010;11:136.

[2]Laslett L, et al. Trials 2020;21:79

OutcomesAbsolute between group difference at 24 weeksP valuePrimaryKnee pain0.8 (-5.6 to 7.2)0.81SecondaryKnee pain (WOMAC)4.2 (-29.1 to 37.5)0.81Knee function (WOMAC)61 (-19.2 to 141.3)0.14Hand pain2.8 (-2.6 to 8.3)0.31Back pain1.9 (-3.9 to 7.8)0.46Leg strength-2.59 (-9.41 to 4.23)0.52Metabolic factorsTotal Cholesterol0.09 (-0.1 to 0.29)0.34HDL Cholesterol-0.03 (-0.1 to 0.03)0.35LDL Cholesterol0.05 (-0.12 to 0.22)0.57Triglycerides0.12 (-0.09 to 0.33)0.27Fasting glucose0.01 (-0.26 to 0.29)0.93hsCRP0.64 (-0.56 to 1.84)0.30

Disclosure of Interests:

Laura Laslett Speakers bureau: once, several years ago, and unrelated to this topic, Grant/research support from: Yes, received funding from Aker Biomarine to conduct this trial, Lieke Scheepers Shareholder of: AstraZeneca, Grant/research support from: Pfizer, unrelated to this topic, Employee of: Previously employed by AstraZeneca, Benny Antony Speakers bureau: Zydus, Grant/research support from: Grant support for investigator-initiated trial from NR Ltd for unrelated research, Anita Wluka: None declared, Catherine Hill: None declared, Lyn March Speakers bureau: Speaker fees from Pfizer Australia Ltd, Bristol Myer Squibb Australia, Abbvie Australia, Grant/research support from: Grant support for my institution from Janssen for unrelated research, Helen Keen: None declared, Petr Otahal: None declared, Flavia Cicuttini: None declared, Graeme Jones: None declared

POS0190 ASSOCIATION BETWEEN OSTEOARTHRITIS-RELATED SERUM BIOCHEMICAL MARKERS OVER 11 YEARS AND KNEE SYMPTOMS IN MIDDLE-AGED ADULTS

Background:

Serum levels of cartilage and joint-specific biochemical markers such as cartilage oligomeric matrix protein (COMP), matrix metalloproteinase (MMP)-3, and hyaluronan (HA) are associated with cartilage degradation, joint tissue degradation, and synovitis in patients with OA. Change in these biomarkers may precede the morphological and clinical manifestations of OA and therefore have been explored as predictive markers in OA. However, few studies have evaluated the association of OA-related biomarkers with knee symptoms in general population-based middle-aged adults

Objectives:

To describe the associations between OA-related biomarkers and knee symptoms in middle-aged adults followed up over 10-13 years

Methods:

Blood samples were collected during the Childhood Determinants of Adult Health (CDAH)-1 study at baseline (year: 2004-06, age: 26–36 years) and 10-13 year follow-up (CDAH-3; year: 2014–2019, age: 36–49 years). Serum samples from baseline (n=156) and follow-up (n= 167) were analyzed for three OA-related biomarkers – namely COMP, MMP-3, and HA– using ELISA. Knee symptoms (pain, stiffness, and dysfunction) were assessed using the WOMAC scale during the CDAH-3 phase. Univariable and multivariable (adjusted for age, sex, and body mass index (BMI)) zero-inflated Poisson regression models with random effects were used to describe the above associations

Results:

The prevalence of knee pain was 46%. In the multivariable model, adjusted for age, sex, and BMI, there was a significant positive association between COMP (ɞ=1.156, 95%CI: 0.989,1.324; p=0.04), MMP-3 (ɞ=1.013, 95%CI: 1.001,1.025; p=0.02), and HA (ɞ=1.008, 95%CI: 1.002,1.015, p=0.01) with knee pain and WOMAC-total score (Table 1) in middle-aged adults. The increase in knee pain per ng/ml increase in COMP, MMP-3, and HA was 15.7%, 1.3%, and 0.8%, respectively. The overall mean biomarker levels decreased over 10-13 years; however, the mean WOMAC-total scores were higher in participants whose COMP and HA levels increased (COMP: 24 (27.31), HA: 14.20 (22.60)) compared to those in whom it decreased or remained stable (COMP: 9.84 (16.83), and HA: 8.28 (13.22)) during this period. There was a significant positive association between COMP (ɞ=1.026, 95%CI: 1.002,1.050, p=0.03) and MMP-3 (ɞ=1.020, 95%CI: 1.009,1.030, p<0.01) measured at baseline and knee pain assessed after 10-13 year in the middle-aged adults (Table 1)

Table 1.

Cross-sectional and longitudinal association between WOMAC symptoms and OA-related biomarkers

VariablesLongitudinal Biomarker at CDAH-1, knee symptom at CDAH-3Cross-sectional Biomarker at CDAH-3, knee symptom at CDAH-3Adjusted. Coef. (95%CI) p-valueAdjusted. Coef. (95%CI) p-valueCOMP (Predictor)WOMAC-total1.047 (1.035, 1.060)1.088 (1.017, 1.159)p<0.01p=0.01Stiffness1.019 (0.988, 1.051)0.877 (0.708, 1.057)p=0.23p=0.12Dysfunction1.045 (1.030, 1.061)1.040 (0.949, 1.130)p<0.01p=0.38MMP3 (Predictor)WOMAC-total1.026 (1.020, 1.031)1.017 (1.010, 1.023)p<0.01p<0.01Pain1.020 (1.009, 1.030)1.013 (1.001, 1.025)p<0.01p=0.03Stiffness1.020 (1.004, 1.035)1.004 (.987, 1.021)p=0.01p=0.66Dysfunction1.029 (1.022, 1.037)1.019 (1.010, 1.026)p<0.01p<0.01HA (Predictor)WOMAC-total0.995 (0.991, 0.999)1.007 (1.003, 1.010)p=0.01p<0.01Pain0.999 (0.991, 1.006)1.008 (1.002, 1.015)p=0.75p=0.01Stiffness0.989 (0.980, 0.998)0.997 (0.989, 1.007)p=0.03p=0.65Dysfunction1.003 (0.998, 1.009)1.015 (1.010, 1.020)p= 0.22p<0.01

Bold denotes statistically significant. Model adjusted for age, sex, and BMI

Conclusion:

OA-related biochemical markers such as COMP and MMP-3 were positively associated with knee pain in population-based middle-aged adults. These results suggest biochemical markers measured in middle-aged adults may be used as a marker of joint pain

Acknowledgements:

AS is supported by International Graduate Research Scholarship, University of Tasmania.

Disclosure of Interests:

Ambrish Singh Employee of: Has worked in the past for Abbott and Eli Lilly and Company, Leigh Blizzard: None declared, Alison Venn: None declared, Graeme Jones: None declared, John Burgess: None declared, Venkat Parameswaran: None declared, Changhai Ding: None declared, Benny Antony: None declared

POS0186 METABOLOMIC SIGNATURES FOR KNEE CARTILAGE VOLUME LOSS OVER 10 YEARS

Background:

Osteoarthritis (OA) is the most common form of arthritis, and its impact is increasing year by year due to an aging population and lack of effective treatments. One of the main structural pathological changes of OA is the loss of articular cartilage. Tools that can predict cartilage loss would help identify people at high risk, thus preventing OA development.

Objectives:

Using a metabolomics approach, the current study aimed to identify serum metabolomic signatures for predicting the loss of knee cartilage volume over 10 years in a well-established community-based cohort - the Tasmania Older Adult Cohort (TASOAC).

Methods:

TASOAC is an on-going, prospective, population-based study of older adults who were randomly selected from the roll of electors in Southern Tasmania, Australia. Participants had a right knee magnetic resonance imaging (MRI) scan at baseline and a 10-year follow-up. Cartilage volume was measured in the medial, lateral, and patellar compartments and change in cartilage volume over 10 years was calculated as percentage change per year. Fasting serum samples collected at 2.6-year follow-up were metabolomically profiled using the TMIC Prime Metabolomics Profiling Assay which measures a total of 143 metabolites. 129 metabolite concentrations passed the quality control and the pairwise ratios of them as the proxies of enzymatic reaction were calculated. Linear regression models were used to test the association between each of the metabolite ratios and change in cartilage volume in each of the knee compartments with adjustment for age, sex, and body mass index (BMI). The significance was defined at a=3.0×10-6 to control multiple testing of 16,512 ratios with Bonferroni method.

Results:

A total of 344 participants (51% females) were included. The mean baseline age was 62.83±6.13 years and the mean BMI was 27.48±4.41 kg/m2. The average follow-up time was 10.84±0.66 years. Cartilage volume reduced by 1.34±0.72%, 1.06±0.58%, and 0.98±0.46% per year in the medial, lateral, and patellar compartments, respectively. Our data showed that an increased ratio of hexadecenoylcarnitine (C16:1) to tetradecanoylcarnitine (C14) was associated with a 0.12±0.02% per year reduction in patellar cartilage volume (p = 8.80×10-7). An increased ratio of hexadecenoylcarnitine (C16:1) to dodecanoylcarnitine (C12) was also associated with a 0.12±0.02% per year reduction in patellar cartilage volume (p = 2.66×10-6). While there were several metabolite ratios associated with cartilage volume loss in the medial and lateral compartments, none of them reached the predefined significance level.

Conclusion:

Our data suggested that alteration of fatty acid β-oxidation is involved in knee cartilage loss, especially in the patellar compartment, and the serum ratio of C16:1 to C14 and to C12 could be used to predict long-term patellar cartilage loss.

Acknowledgements:

We thank all the study participants who made the study possible. The original TASOAC study was supported by the National Health and Medical Research Council (NHMRC) and the current study was supported by the Canadian Institutes of Health Research (CIHR).

Disclosure of Interests:

None declared

Statistical shape modeling of the hip and the association with hip osteoarthritis: a systematic review

OBJECTIVE

To summarize available evidence on the association between hip shape as quantified by statistical shape modeling (SSM) and the incidence or progression of hip osteoarthritis.

DESIGN

We conducted a systematic search of five electronic databases, based on a registered protocol (available: PROSPERO CRD42020145411). Articles presenting original data on the longitudinal relationship between radiographic hip shape (quantified by SSM) and hip OA were eligible. Quantitative meta-analysis was precluded because of the use of different SSM models across studies. We used the Newcastle-Ottawa Scale (NOS) for risk of bias assessment.

RESULTS

Nine studies (6,483 hips analyzed with SSM) were included in this review. The SSM models used to describe hip shape ranged from 16 points on the femoral head to 85 points on the proximal femur and hemipelvis. Multiple hip shape features and combinations thereof were associated with incident or progressive hip OA. Shape variants that seemed to be consistently associated with hip OA across studies were acetabular dysplasia, cam morphology, and deviations in acetabular version (either excessive anteversion or retroversion).

CONCLUSIONS

Various radiographic, SSM-defined hip shape features are associated with hip OA. Some hip shape features only seem to increase the risk for hip OA when combined together. The heterogeneity of the used SSM models across studies precludes the estimation of pooled effect sizes. Further studies using the same SSM model and definition of hip OA are needed to allow for the comparison of outcomes across studies, and to validate the found associations.

Norwich COVID-19 testing initiative pilot: evaluating the feasibility of asymptomatic testing on a university campus

Background

There is a high prevalence of COVID-19 in university-age students, who are returning to campuses. There is little evidence regarding the feasibility of universal, asymptomatic testing to help control outbreaks in this population. This study aimed to pilot mass COVID-19 testing on a university research park, to assess the feasibility and acceptability of scaling up testing to all staff and students.

Methods

This was a cross-sectional feasibility study on a university research park in the East of England. All staff and students (5625) were eligible to participate. All participants were offered four PCR swabs, which they self-administered over two weeks. Outcome measures included uptake, drop-out rate, positivity rates, participant acceptability measures, laboratory processing measures, data collection and management measures.

Results

798 (76%) of 1053 who registered provided at least one swab; 687 (86%) provided all four; 792 (99%) of 798 who submitted at least one swab had all negative results and 6 participants had one inconclusive result. There were no positive results. 458 (57%) of 798 participants responded to a post-testing survey, demonstrating a mean acceptability score of 4.51/5, with five being the most positive.

Conclusions

Repeated self-testing for COVID-19 using PCR is feasible and acceptable to a university population.

Incidence and circumstances of falls among middle-aged women: a cohort study

This was the first study assessing falls prospectively in middle-aged women. The 1-year incidence was 42% for any fall, which suggest falls are a major issue in middle-aged women. Middle-aged women, particularly those sustaining a fall, could be a target group for fall-prevention strategies.

PURPOSE

Incidence and circumstances of falls in middle-aged people are poorly understood. This cohort study aimed to elucidate the incidence and circumstances of falls over 1 year in middle-aged women.

METHODS

Falls were recorded monthly for 1 year by questionnaire in 2017-2019 in a population-based sample of women aged 41-62 years. The incidence of falls and injurious falls and related circumstances were descriptively analysed.

RESULTS

Of 273 women, 115 sustained 209 falls. The 1-year incidence was 42% for any fall, 17% for multiple (two or more) falls, and 24% for injurious falls. The incidence was greater in older age groups for any fall (33, 45, and 44% for people aged < 50, 50-55, and > 55 years, respectively), multiple falls (7, 14, and 22%) and injurious falls (15, 20, and 28%), although only the incidence of multiple falls was significantly increased across the three age groups (P = 0.01). Most falls occurred outdoors (71%) and were attributed to tripping and slipping (60%) CONCLUSIONS: Falls are a major issue in middle-aged women, a group that has been largely ignored in the prevention of falls. Middle-aged women, in particular those sustaining a fall, could be a target group for fall-prevention strategies. Future studies are needed to identify risk factors for falling in this population so as inform the development of strategies for preventing falls in middle-aged women.

Evaluating survey methods for bat roost detection in ecological impact assessment

The disturbance, damage and destruction of roosts are key drivers of bat population declines worldwide. In countries where bats are protected by law, bat roost surveys are often required to inform ecological impact assessments. Yet, evidence‐based information on survey methodology to detect bat roosts is crucially lacking, and failing to detect a roost can lead to serious errors during decision‐making processes. Here, we assess the efficacy of bat roost surveys in buildings as implemented in the UK. These consist of a daytime inspection of buildings, followed by a series of acoustic surveys at dusk/dawn if during the daytime inspection evidence of bats is found, or if the absence of bats cannot be verified. We reviewed 155 ecological consultants’ reports to (1) compare survey outcome between daytime inspection and acoustic surveys and (2) determine the minimum sampling effort required during acoustic surveys to be confident that no bats are roosting within a building. We focused on two genera of bats most frequently found in buildings in Europe – Pipistrellus (crevice roosting species with high‐intensity echolocation calls that can be easily detected by ultrasound detectors) and Plecotus (species that roost in open spaces and which emit faint echolocation calls that are difficult to detect). Daytime inspections were efficient in detecting open‐roosting species such as Plecotus species but were likely to miss the presence of crevice‐dwelling ones (here Pipistrellus species) which may lead to erroneous conclusions if no acoustic surveys are subsequently prescribed to confirm their absence. A minimum of three and four acoustic surveys are required to be 95% confident that a building does not host a roost of Pipistrellus species and Plecotus species, respectively, thus exceeding current recommendations. Overall, we demonstrated that reports submitted as part of an ecological impact assessment provide suitable data to test and improve survey methods.

Skin Photosensitivity is Associated with 25-Hydroxyvitamin D and BMD but not Fractures Independent of Melanin Density in Older Caucasian Adults

Whether skin photosensitivity modulates sun exposure behaviours, consequent vitamin D status and skeletal health outcomes independently of constitutive pigmentation have not been systematically investigated. 1072 community-dwelling adults aged 50-80 years had skin photosensitivity quantified by questionnaire and melanin density by spectrophotometry. Bone mineral density (BMD), falls risk and 25-hydroxyvitamin D (25OHD) were measured using DXA, short form physiological profile assessment and radioimmunoassay, respectively. Sun exposure and symptomatic fractures were assessed by questionnaire. Participants were followed up at 2.5 (n = 879), 5 (n = 767) and 10 (n = 571) years. Higher resistance to sunburn and greater ability to tan were associated with reduced sun protection behaviours (RR 0.87, p < 0.001 & RR 0.88, p < 0.001), higher lifetime discretionary sun exposure in summer (RR 1.05, p = 0.001 & RR 1.07, p = 0.001) and winter (RR 1.07, p = 0.001 & RR 1.08, p = 0.02) and fewer lifetime sunburns (RR 0.86, p < 0.001 & RR 0.91, p = 0.001). Higher resistance to sunburn was associated with lower total body (β =  - 0.006, p = 0.047) and femoral neck (β = - 0.006, p = 0.038) BMD, but paradoxically, fewer prevalent fractures (RR 0.94, p = 0.042). Greater ability to tan was associated with higher 25OHD (β = 1.43, p = 0.04), lumbar spine (β = 0.014, p = 0.046) and total body (β = 0.013, p = 0.006) BMD, but not fracture or falls risk. These associations were independent of constitutive melanin density. Cutaneous photosensitivity was associated with sun exposure behaviours, cutaneous sequelae and, consequently, 25OHD and BMD in older Caucasian adults independent of constitutive melanin density. There was no consistent association with fracture outcomes, suggesting environmental factors are at least as important.