POS0146 INCREASED RISKS OF AORTIC REGURGITATION AND ATRIAL FIBRILLATION IN RADIOGRAPHIC AXIAL SPONDYLOARTHRITIS PATIENTS: A 10 YEAR NATIONWIDE COHORT STUDY

Background

Radiographic axial spondyloarthritis (r-axSpA) has increased risk of cardiovascular disease. Other cardiac manifestations such as conduction disturbance and valvular diseases were also suggested as co-morbidities in r-axSpA patients, however, the risk of these cardiac manifestation in r-axSpA were seldomly evaluated in large cohort.

Objectives

To compare the incidences of aortic regurgitation, atrial fibrillation (AF), and atrioventricular (AV) block II–III between r-axSpA patients and the general population (GP).

Methods

National Health Insurance Services data were used. R-axSpA patients (N = 8,877) and the age- and sex-matched GP (N = 26,631) were followed from August, 2006 to December, 2019. Incidence rates and standardized incidence ratios (SIR) of aortic regurgitation, AF, and AV block II–III were compared between these groups. Ten year incidence rates and hazard ratios (HRs) were calculated by the Kaplan–Meier method and Cox regression analysis.

Results

Incidence rates of aortic regurgitation, AV block II–III, and AF in the r-axSpA group were 0.42, 0.21, and 4.0 per 1000 person-years, respectively. In the r-axSpA group, the SIR for aortic regurgitation was highest among 40–49-year-old men (4.11). Incidence rates of aortic regurgitation and AF were higher in the r-axSpA group than in the GP group (both p < 0.001), whereas the difference was insignificant for AV block II–III. In multivariate analysis, HRs for aortic regurgitation and AF were higher in the r-axSpA group than in the GP group (HR (95% confidence interval) = 2.55 (1.49–4.37) and 1.20 (1.04–1.39), respectively), but the difference was insignificant for AV block II–III.

Conclusion

Compared with the GP, r-axSpA patients are at increased risk of aortic regurgitation and AF, but not AV block II–III. These patients should be carefully monitored for occurrence of aortic regurgitation and AF.

References

[1]Agca R, Heslinga SC, Rollefstad S, et al. EULAR recommendations for cardiovascular disease risk management in patients with rheumatoid arthritis and other forms of inflammatory joint disorders: 2015/2016 update. Ann Rheum Dis 2017; 76: 17-28.

[2]Szabo SM, Levy AR, Rao SR, et al. Increased risk of cardiovascular and cerebrovascular diseases in individuals with ankylosing spondylitis: a population-based study. Arthritis Rheum 2011; 63: 3294-3304.

[3]Morovatdar N, Watts GF, Bondarsahebi Y, et al. Ankylosing Spondylitis and risk of Cardiac Arrhythmia and Conduction Disorders: A systematic review and meta analysis. Curr Cardiol Rev 2021.

[4]Bengtsson K, Forsblad-d’Elia H, Lie E, et al. Risk of cardiac rhythm disturbances and aortic regurgitation in different spondyloarthritis subtypes in comparison with general population: a register-based study from Sweden. Ann Rheum Dis 2018; 77: 541-548.

[5]Dik VK, Peters MJ, Dijkmans PA, et al. The relationship between disease-related characteristics and conduction disturbances in ankylosing spondylitis. Scand J Rheumatol 2010; 39: 38-41.

Disclosure of Interests

None declared

The need to study rural cancer outcome disparities at the local level: a retrospective cohort study in Kansas and Missouri

Background

Rural residence is commonly thought to be a risk factor for poor cancer outcomes. However, a number of studies have reported seemingly conflicting information regarding cancer outcome disparities with respect to rural residence, with some suggesting that the disparity is not present and others providing inconsistent evidence that either urban or rural residence is associated with poorer outcomes. We suggest a simple explanation for these seeming contradictions: namely that rural cancer outcome disparities are related to factors that occur differentially at a local level, such as environmental exposures, lack of access to care or screening, and socioeconomic factors, which differ by type of cancer.

Methods

We conducted a retrospective cohort study examining ten cancers treated at the University of Kansas Medical Center from 2011 to 2018, with individuals from either rural or urban residences. We defined urban residences as those in a county with a U.S. Department of Agriculture Urban Influence Code (UIC) of 1 or 2, with all other residences defines a rural. Inverse probability of treatment weighting was used to create a pseudo-sample balanced for covariates deemed likely to affect the outcomes modeled with cumulative link and weighted Cox-proportional hazards models.

Results

We found that rural residence is not a simple risk factor but rather appears to play a complex role in cancer outcome disparities. Specifically, rural residence is associated with higher stage at diagnosis and increased survival hazards for colon cancer but decreased risk for lung cancer compared to urban residence.

Conclusion

Many cancers are affected by unique social and environmental factors that may vary between rural and urban residents, such as access to care, diet, and lifestyle. Our results show that rurality can increase or decrease risk, depending on cancer site, which suggests the need to consider the factors connected to rurality that influence this complex pattern. Thus, we argue that such disparities must be studied at the local level to identify and design appropriate interventions to improve cancer outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-12190-w.

Prediction of long-term survival after gastrectomy using random survival forests

BACKGROUND

No well validated and contemporaneous tools for personalized prognostication of gastric adenocarcinoma exist. This study aimed to derive and validate a prognostic model for overall survival after surgery for gastric adenocarcinoma using a large national dataset.

METHODS

National audit data from England and Wales were used to identify patients who underwent a potentially curative gastrectomy for adenocarcinoma of the stomach. A total of 2931 patients were included and 29 clinical and pathological variables were considered for their impact on survival. A non-linear random survival forest methodology was then trained and validated internally using bootstrapping with calibration and discrimination (time-dependent area under the receiver operator curve (tAUC)) assessed.

RESULTS

The median survival of the cohort was 69 months, with a 5-year survival of 53.2 per cent. Ten variables were found to influence survival significantly and were included in the final model, with the most important being lymph node positivity, pT stage and achieving an R0 resection. Patient characteristics including ASA grade and age were also influential. On validation the model achieved excellent performance with a 5-year tAUC of 0.80 (95 per cent c.i. 0.78 to 0.82) and good agreement between observed and predicted survival probabilities. A wide spread of predictions for 3-year (14.8-98.3 (i.q.r. 43.2-84.4) per cent) and 5-year (9.4-96.1 (i.q.r. 31.7-73.8) per cent) survival were seen.

CONCLUSIONS

A prognostic model for survival after a potentially curative resection for gastric adenocarcinoma was derived and exhibited excellent discrimination and calibration of predictions.

COVID-19 in pregnant women with heart diseases. Adverse maternal and fetal outcomes. Case series from InCor registry of Pregnancy and Heart Disease

Background

Heart disease is the leading non-obstetric cause of maternal death during pregnancy. In this field, the emergence of pandemic COVID-19 has caused the worst-case scenario considering that pregnant women are more susceptible to viral infections, and preexisting cardiac disease is the most prevalent co-morbidity among COVID-19 deaths.

Purpose

To assess the maternal and fetal outcomes of COVID-19 during pregnancy of women with heart diseases.

Methods

During the year 2020, among 82 pregnant women with heart disease followed consecutively at the Instituto do Coração-InCor, seven of them with an average age of 33.2 years had COVID-19 during their pregnancies. The underlying heart diseases were rheumatic valve disease (5 pt), congenital heart disease (1 pt) and one case with acute myocarditis, without preexisting cardiopathy. The prescription (antibiotics, inotropes, corticosteroids and others) used was according to the clinical conditions required for each patient, however subcutaneous or intravenous heparin was used in all patients.

Results

Only one case had an uneventful maternal-fetal course, the other six women required hospitalization / ICU for an average of 25.3 days, including the need for mechanical ventilation in two of them. Serious complications were related to respiratory failure (ADRS), recurrent atrial flutter with hemodynamic instability, acute pulmonary edema, and cardiogenic shock associated with sepsis which caused two maternal deaths. There were two emergency mitral valve interventional, percutaneous balloon valvuloplasty and valve bioprosthesis replacement, respectively. There were five premature births with an average gestational age of 34.2 weeks of gestation, which resulted in one stillbirth. Pathological findings of three placental and the six-months follow-up of the babies did not confirm vertical transmission of COVID-19.

Conclusions

The uncertain evolution given of the overlapping complications of three conditions – COVID-19, pregnancy, and heart disease – implies an increased risk for women with heart diseases of childbearing age, for whom pregnancy should be discouraged and planned after vaccination

FUNDunding Acknowledgement

Type of funding sources: None.

Estimating power for clinical trials with Patient Reported Outcomes - using Item Response Theory

OBJECTIVES

Patient reported outcomes (PRO) are widely used in quality of life (QOL) studies, health outcomes research, and clinical trials. The importance of PRO has been advocated by health authorities. Patient Reported Outcomes Measurement Information System (PROMIS) is a collection of standardized measures of PROs using Item Response Theory (IRT). However, in clinical trials with PROs as endpoints, observed scores are routinely used for power estimation rather than IRT scores. This paper aims to fill this gap and estimate power in a two-arm clinical trials with PROMIS measures as endpoints with IRT model.

STUDY DESIGN AND SETTING

We conducted a series of simulations to study the IRT power with validated PROMIS measures controlling factors including sample size, effect size, number of items, and missing data proportion.

RESULTS

Our results showed that sample size, effect size, and number of items are important indicators of IRT based power estimation for PROMIS measures. When effect size is small and sample size is limited, IRT model provides higher power than the closed form formula.

CONCLUSION

IRT based simulation should be used for power estimation in two-armed clinical, especially when there is small effect size or small sample size.

A framework for personalized mammogram screening

Breast cancer screening guidelines serve as crucial evidence-based recommendations in deciding when to begin regular screenings. However, due to developments in breast cancer research and differences in research interpretation, screening guidelines can vary between organizations and within organizations over time. This leads to significant lapses in adopting updated guidelines, variable decision making between physicians, and unnecessary screening for low to moderate risk patients (Jacobson and Kadiyala, 2017; Corbelli et al., 2014). For analysis, risk factors were assessed for patient screening behaviors and results. The outcome variable for the first analysis was whether the patient had undergone screening. The risk factors considered were age, marital status, education level, rural versus urban residence, and family history of breast cancer. The outcome variable for the second analysis was whether patients who had undergone breast cancer screening presented abnormal results. The risk factors considered were age, Body Mass Index, family history, smoking and alcohol status, hormonal contraceptive use, Hormone Replacement Therapy use, age of first pregnancy, number of pregnancies (parity), age of first menses, rural versus urban residence, and whether or not patients had at least one child. Logistic regression analysis displayed strong associations for both outcome variables. Risk of screening nonattendance was negatively associated with age as a continuous variable, age as a dichotomous variable, being married, any college education, and family history. Risk of one or more abnormal mammogram findings was positively associated with family history, and hormonal contraceptive use. This procedure will be further developed to incorporate additional risk factors and refine the analysis of currently implemented risk factors.

Efficacy and costs of a workplace wellness programme

BACKGROUND

Research investigating the efficacy of workplace wellness programmes to promote exercise, and by extension, reduce obesity and increase productivity has proliferated in recent years. Although preliminary work is encouraging, more work is needed.

AIMS

To evaluate the effects and overall cost of a workplace exercise programme on multiple physical outcomes, including body mass index, aerobic fitness and muscular fitness.

METHODS

Data from the Bruin Health Improvement Programme .5 (BHIP) between August 2013 and July 2018 were analysed. BHIP is a 12-week workplace wellness programme that assesses multiple areas of physical and mental health. For this study, changes in weight, waist-to-hip ratio, aerobic fitness and muscular endurance were analysed using paired samples t-tests and chi-squared tests. Using results from a prior analysis of Medical Expenditure Panel Survey, the estimated medical expenditure savings associated with weight loss were also analysed.

RESULTS

A total of 518 participants (84% female) took part in the BHIP programme (mean age = 41 years, SD = 1.17). There were significant decreases in all anthropometric indices and significant increases in all fitness outcomes (P < 0.01) from baseline to follow-up. Estimated programme cost per participant, per session was $473 US Dollars (USD), and weight loss is estimated to reduce annual medical care costs by ~$2200 USD.

CONCLUSIONS

Results showed significant improvements in all physical outcomes of interest. Additionally, there appears to be an inverse relationship between improvements in employee health and employer healthcare costs. Strengths, limitations and future directions are discussed.

MRI-Visible Perivascular Spaces in the Centrum Semiovale Are Associated with Brain Amyloid Deposition in Patients with Alzheimer Disease-Related Cognitive Impairment

BACKGROUND AND PURPOSE

The association of perivascular spaces in the centrum semiovale with amyloid accumulation among patients with Alzheimer disease-related cognitive impairment is unknown. We evaluated this association in patients with Alzheimer disease-related cognitive impairment and β-amyloid deposition, assessed with [¹⁸F] florbetaben PET/CT.

MATERIALS AND METHODS

MR imaging and [¹⁸F] florbetaben PET/CT images of 144 patients with Alzheimer disease-related cognitive impairment were retrospectively evaluated. MR imaging-visible perivascular spaces were rated on a 4-point visual scale: a score of ≥3 or <3 indicated a high or low degree of MR imaging-visible perivascular spaces, respectively. Amyloid deposition was evaluated using the brain β-amyloid plaque load scoring system.

RESULTS

Compared with patients negative for β-amyloid, those positive for it were older and more likely to have lower cognitive function, a diagnosis of Alzheimer disease, white matter hyperintensity, the Apolipoprotein E ε4 allele, and a high degree of MR imaging-visible perivascular spaces in the centrum semiovale. Multivariable analysis, adjusted for age and Apolipoprotein E status, revealed that a high degree of MR imaging-visible perivascular spaces in the centrum semiovale was independently associated with β-amyloid positivity (odds ratio, 2.307; 95% CI, 1.036-5.136; P = .041).

CONCLUSIONS

A high degree of MR imaging-visible perivascular spaces in the centrum semiovale independently predicted β-amyloid positivity in patients with Alzheimer disease-related cognitive impairment. Thus, MR imaging-visible perivascular spaces in the centrum semiovale are associated with amyloid pathology of the brain and could be an indirect imaging marker of amyloid burden in patients with Alzheimer disease-related cognitive impairment.

Analysis of local invasion and regional spread in malignant sublingual gland tumour: Implications for surgical planning

Malignant tumours arising from the sublingual glands are very rare, and the extent and frequency of local invasion or regional spread in malignant sublingual gland tumour (MSLT) has not been fully studied due to the disease rarity. To provide comprehensive features of local and regional spread of MSLT, we reviewed 20 surgical cases for detailed pathological analyses among 26 cases diagnosed as having primary MSLT. Adenoid cystic carcinoma (ACC) was the most common pathological subtype, followed by mucoepidermoid carcinoma. Disease-free and overall survivals at 5 years were 76.1 % and 77.7 %, respectively. High-grade malignant tumours and grade 2-3 ACC accounted for 41.7 % and 85.7 %. Clinical and pathological extraparenchymal extensions were found in 34.6 % and 80.0 %, respectively. Tumour invasion to the lingual nerve and submandibular gland/ductal system were also detected in 40.0 % and 28.6 %. The incidences of lingual nerve invasion in ACC and ACC ≥4 cm were 30.8 % and 42.9 %. Regional nodal involvement occurred in seven of 26 cases, and all metastatic lymph nodes were found in neck levels Ib and IIa. In summary, a significant portion of MSLT cases consisted of high-grade tumours and grade 2-3 ACC; therefore local invasion into adjacent structures should be cautiously evaluated in cases of MSLT.

Abstract SP112: Spatial variance signatures/Intra-tumor zonation in TNBC

It is increasingly clear that triple negative breast cancer (TNBC) is a heterogeneous disease with variable clinical presentation, histological features and response to therapy. While these differences have been partially explained by inter- and intra-tumoral heterogeneity, spatial heterogeneity represented by the tumor architecture plays a critical role in clonal evolution and displays a landscape for different compartment-specific processes and cell-to-cell specific interactions. To better understand the impact of spatial heterogeneity on gene-expression-defined cell populations, we have coupled single-cell RNA sequencing with multiplex immunofluorescence (IF). Multiplex immunofluorescence using specific markers for each cell cluster, integrated with computational image analyses and neighborhood maps, has revealed spatial zonation of single cell subpopulations. Zonation of single cell populations was coupled to hypoxia and overlayed distinct metabolic tumor zones and defined areas of differential stress and cell plasticity that give rise to tumor cells with enhanced fitness and aggressivity.

Citation Format: M Park, C Martínez Ramirez, Y Yang, A Blanchet-Cohen, H Kuasne, A Fortier, J Ragoussis, P Savage, A Omeroglou, S Meterissian, S Costantino, C Kleinman. Spatial variance signatures/Intra-tumor zonation in TNBC [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr SP112.

Biodegradable-polymer versus durable-polymer drug eluting stents for coronary artery disease: systematic review and a meta-analysis

Background

Biodegradable polymer drug-eluting stents (BP-DES) has been developed to overcome the potential drawbacks of the first-generation durable polymer drug-eluting stents (DP-DES). However, it is still under debate whether BP-DES is associated with superior efficacy and safety over DP-DES.

Purpose

We sought to compare the effects of BP-DES and DP-DES in patients with coronary artery disease.

Methods

We performed systematic review and a meta-analysis of randomized controlled trials comparing BP-DES and DP-DES on clinical outcomes in patients with coronary artery disease using CE-mark approved drug-eluting stents (DES) with at least 1-year follow-up. We included 32 studies involving 39,686 patients (BP-DES: 21,439 patients, and DP-DES: 18,247 patients). Primary outcome measure was target vessel failure (TVF; equivalent to the composite of cardiac death, target-vessel myocardial infarction, or ischemia-driven target vessel revascularization). We performed subgroup analysis according to the DP-DES generations (newer-generation DP-DES: 15,179patients, and first-generation DP-DES: 3,068 patients), and the effects of newer-generation DP-DES was compared with the BP-DES according to the BP-DES strut thickness (Ultra-thin strut [&lt;80μm]: 7,572 patients, Thin-strut [80–100μm]: 5,465 patients, and Thick-strut [≥80μm]: 5,876 patients).

Results

The odds for TVF was not significantly different between the BP-DES group and the DP-DES group in the entire study population (odds ratio [OR] 0.96, 95% confidence interval [CI] [0.90–1.02], P=0.20). The odds for TVF was significantly low in the BP-DES group relative to the first-generation DP-DES group, however the odds were comparable between the BP-DES group and the newer-generation DP-DES group (BP-DES versus first-generation DP-DES: OR 0.82, 95% CI [0.73–0.92], P&lt;0.001, and BP-DES versus newer-generation DP-DES: OR 1.00, 95% CI [0.93–1.08], P=0.99). We also found no significant differences between the BP-DES and newer-generation DP-DES, in all subgroups stratified by the BP-DES strut thickness (Ultra-thin strut BP-DES versus newer-generation DP-DES: OR 0.88, 95% CI [0.76–1.02], P=0.10, Thin-strut BP-DES versus newer-generation DP-DES: OR 1.01, 95% CI [0.90–1.13], P=0.89, and Thick strut BP-DES versus newer-generation DP-DES: OR 1.11, 95% CI [0.99–1.25], P=0.08).

Conclusions

In this meta-analysis of randomized controlled trials evaluating clinical outcomes, there was no significant differences between BP-DES and DP-DES. We found beneficial effects of BP-DES relative to the first-generation DP-DES, however, there was no statistical differences between BP-DES and newer-generation DP-DES, irrespective of the BP-DES strut thickness.

Pooled odds ratios for clinical outcomes

Funding Acknowledgement

Type of funding source: None

0558 Sleep Disordered Breathing and Right Ventricular Electrocardiographic and Functional Characteristics in Group 1 Pulmonary Arterial Hypertension

Introduction

Right ventricular (RV) electrophysiologic and functional alterations related to sleep disordered breathing (SDB) in pulmonary arterial hypertension (PAH) are not well understood. We hypothesize an association between SDB and RV electrophysiological/functional measures in World Symposium of Pulmonary Hypertension (WSPH) Group 1 PAH.

Methods

The NHLBI multicenter PVDOMICS study (NCT02980887) enrolls patients with PAH undergoing a battery of assessments including home sleep apnea testing(NOX-T3, Carefusion®) or with historical sleep study data. Logistic(OR,95%CI) and linear(beta coefficients,95%CI) regression models adjusted for age, sex, race, body mass index (BMI, kg/m2), PAH medications, supplemental oxygen(O2), positive airway pressure(PAP) were used to assess associations of SDB(apnea hypopnea index,(AHI), ≥3% desaturations(hypopnea), percentage recording time with SaO2&lt;90% (TRT&lt;90%) with electrocardiographic measures: RV hypertrophy(RVH), right bundle branch block(RBBB), and right axis deviation(RAD), echocardiographically-derived RV systolic pressure(RVSP) and RV ejection fraction(RVEF) from cardiac MRI. Analyses were performed based on an overall significance level of 0.05, using SAS software (version 9.4, Cary, NC).

Results

The analysis consisted of 182 PAH participants with age: 52.5±13.9 years, 71.4% female, 88.9% Caucasian, BMI:30.3±7.8 kg/m2, RVEF: 37.3±11.6, and RVSP: 67.0±23.4. None of the electrocardiographic measures were associated with AHI and only RVH was significantly associated with TRT&lt;90% (1.25:1.09,1.43),p=0.001. Although AHI was not associated with RVSP, a 10% increase in TRT&lt;90% was associated with a 2.60mmHg increase in RVSP (2.60:1.44,3.76),p&lt;0.001. Each 10-unit increase in AHI was associated with a 2.72% reduction of RVEF (-2.72:-4.89,-0.56),p=0.014, and each 10-unit increase in TRT&lt;90% was associated with a 0.72% reduction of RVEF (-0.72:-1.38,-0.06),p=0.033.

Conclusion

We identify nocturnal hypoxia as a predictor of RV electrophysiological and functional alterations even after consideration of confounding factors. SDB as determined by AHI was also more so associated with reduced RVEF than hypoxia. Future mechanistic studies should focus on further elucidation of SDB and nocturnal hypoxia on pathogenesis of RV dysfunction in PAH.

Support

U01HL125218/U01HL125205/U01HL125212/U01HL125208/U01HL125175/U01HL125215, U01HL125177/Pulmonary Hypertension Association

1151 Is Timing Of Light Exposure Different In Women With Chronic Migraine?

Introduction

Light avoidance is a common coping behavior of individuals with migraine headaches. It is not known whether timing of light exposure is different in individuals with chronic migraine (CM) compared to those without migraine and how this may relate to headache frequency and severity. We tested this by examining timing of the brightest and darkest light and headaches in women with chronic migraines and healthy controls.

Methods

Sixteen women with CM (mean age = 33.07) and 18 female healthy controls (HC; mean age = 32.22) completed daily ratings of headache severity (0-10, severity &gt; 2 classified as headache) concurrent with light exposure measured by wrist actigraphy for approximately one month (M=28.00 days, range=21-36). Start time of each day’s 10-hour periods of maximum light (M10) and 5-hour periods of lowest light (L5) were calculated and averaged for each participant. T-tests and Cohen’s d effect sizes were used to compare groups. Pearson correlation coefficients were calculated to examine associations between M10/L5 timing and headache frequency and severity.

Results

M10 was earlier in the CM group compared to the HC group (07:42±00:47 vs. 08:50±00:58, t(32)=3.69, p=0.0008, d=1.08). The CM group exhibited non-significant trend towards earlier L5 compared to the HC group (12:26±00:48 vs. 01:07±01:03, t(32)=1.89, p=0.0723, d=0.62). Among individuals with CM, later M10 timing was associated with more severe average daily headache (r=0.60, p=0.0136) and more frequent headaches (r=0.55, p=0.0257). Later L5 timing was significantly associated with more severe average daily headache (r=0.66, p=0.0052) and showed a non-significant trend toward association with more frequent headaches (r=0.47, p=0.0686).

Conclusion

Timing of the greatest light exposure period was earlier in CM compared to HC. Within the CM group, those who had earlier light and dark periods reported lower headache severity and fewer days with headaches. These findings suggest the possibility of a role for the circadian system in chronic migraine.

Support

This study was supported by grant R21NS081088 from the National Institutes of Health.

Modification of the RANKL-RANK-binding site for the immunotherapeutic treatment of osteoporosis

Here, we proposed the use of mutated RANKL as an immunogen for active immunization and to induce anti-cytokine antibodies for osteoporosis treatment.

INTRODUCTION

Osteoclasts are responsible for bone resorption in bone-related disorders. Anti-cytokine therapeutic antibodies such as denosumab are effective for the treatment of osteoporosis. However, problems with antibody manufacturing and the immunogenicity caused by multiple antibody doses have led to the use of auto-cytokines as immunogens to induce anti-cytokine antibodies.

METHODS

RANKL was point-mutated based on the crystal structure of the complex of RANKL and its receptor RANK.

RESULTS

As a proof of concept, immunization with RANKL produced high levels of specific antibodies and blocked osteoclast development in vitro and inhibited osteoporosis in RANKL-treated or ovariectomized mouse models.

CONCLUSIONS

The results demonstrate the successful use of mutated RANKL as an immunogen for the induction of anti-RANKL immune response. This strategy is useful in general anti-cytokine immunotherapy to avoid toxic side effects of osteoporosis treatment.

Factors influencing the release of potentially toxic elements (PTEs) during thermal processing of electronic waste

The release of potentially toxic elements as airborne fine particulates is a significant environmental risk associated with recycling e-waste. Some of these may redeposit near emission sites or be transported over long distances causing wide-spread pollution. With an aim to identify key factors affecting particulate emissions, we report novel investigations on the adsorptive capture of particulate matter (PM) released during low temperature pyrolysis (600 °C; 15 min) of waste printed circuit boards (PCBs). A significant proportion of the released particulates (5.3 to 37%) were captured by adsorbents located downstream and in close proximity to the emitting source. Data was collected for four different PCBs and three adsorbents: alumina, silica-gel and activated carbon. With sizes ranging from nanoparticles to over 10 µm, adsorbed particulates were present as fines, spheres, oblongs, clusters and larger particles with no specific shape. Of the 24 elements identified initially in waste PCBs, only 14 were detected in released particulates: major PTEs- Zn, Sn, Pb and Cu (up to 400 ppm); minor PTEs- Ni, Mn, Cd, Cr and Ba (up to 10 ppm); trace PTEs- Co, In, Bi, Be and Sb (up to 1 ppm). Key factors influencing the release of PTEs during thermal processing were identified as basic elemental characteristics, densities, melting points, vapor pressures, initial concentrations, local bonding and mechanical strength. These results show that the presence of low melting point/high vapour pressure elements (Zn, Pb, Sn) should be minimised for a significant reduction in PTE emissions during e-waste processing.

P361 Assessment of accuracy and reproducibility of coronary flow reserve measured by SPECT in patients with known or suspected coronary artery disease

Funding Acknowledgements

Spectrum Dynamics

Background

Traditional relative assessment of regional myocardial perfusion by single photon emission computed tomography (SPECT) has limited ability to identify multivessel coronary artery disease, as well as diffuse atherosclerosis and coronary microvascular dysfunction. Current gamma cameras with cadmium-zinc-telluride (CZT) detectors have higher temporal resolution and sensitivity and allow the acquisition of multi-frame images and quantification of absolute myocardial blood flow (MBF) and coronary flow reserve (CFR

Purpose

The aim of this study was to assess the accuracy and reproducibility of quantitative measurements of MBF and CFR obtained with a CZT SPECT system compared to PET in a cohort of patients with known or suspected coronary artery disease.

Methods

Accuracy was assessed in 22 patients who underwent dynamic rest/stress 99mTc-sestamibi-SPECT and 13N-ammonia PET myocardial perfusion imaging within two weeks of each other. Fourteen patients comprised the reproducibility cohort and underwent two dynamic 99mTc-sestamibi SPECT scans within two weeks. A rest/pharmacological stress single-day SPECT protocol was performed, using a 1:3 dose ratio. SPECT image reconstruction was performed using a spline-fitting method and SPECT MBF was quantified using a net retention kinetic model in commercially available software. Rest MBF and CFR were adjusted for heart-rate pressure product.

Results

Global MBF at rest and stress showed a good correlation between SPECT and PET (r = 0.814, p &lt; 0.001). For global rest MBF the mean difference between the two techniques was -0.25 ± 0.24 ml/min/g, while for stress MBF mean difference was -0.21 ± 0.40 ml/min/g. We also observed a significant correlation between global SPECT and PET CFR measurements (r = 0.745, p &lt; 0.001), with no significant difference between the two (mean difference: 0.16 ± 0.50). Regarding the reproducibility cohort, the correlation between global CFR measured by two SPECT scans was also significant (r = 0.616, p = 0.019), with a mean difference of 0.14 ±0.51. The mean difference between scans for rest MBF (-0.05 ± 0.19) and stress MBF (0.01 ± 0.42) were also not significant.

Conclusion

MBF and CFR quantification is feasible using a CZT gamma camera and provides accurate and reproducible results that correlate with 13N-ammonia PET. This may be of special relevance in sites where PET is not available, enabling MBF and CFR quantification with CZT SPECT cameras.

Abstract P361 Figure.

Optimizing Retrieval of Biospecimens Using the Curated Cancer Clinical Outcomes Database (C3OD)

To fully support their role in translational and personalized medicine, biorepositories and biobanks must continue to advance the annotation of their biospecimens with robust clinical and laboratory data. Translational research and personalized medicine require well-documented and up-to-date information, but the infrastructure used to support biorepositories and biobanks can easily be out of sync with the host institution. To assist researchers and provide them with accurate pathological, epidemiological, and bio-molecular data, the Biospecimen Repository Core Facility (BRCF) at the University of Kansas Medical Center (KUMC) merges data from medical records, the tumor registry, and pathology reports using the Curated Cancer Clinical Outcomes Database (C3OD). In this report, we describe the utilization of C3OD to optimally retrieve and dispense biospecimen samples using these 3 data sources and demonstrate how C3OD greatly increases the efficiency of obtaining biospecimen samples for the researchers.

A survey of health care professionals and oncology patients at the McGill University Health Centre reveals enthusiasm for establishing a postmortem rapid tissue donation program

Background

In the early developmental phase of a postmortem rapid tissue donation (rtd) program for patients with metastatic cancer, we surveyed health care professionals (hcps) and oncology patients at the McGill University Health Centre (muhc) to assess their knowledge and attitudes pertaining to rtd from metastatic cancer patients for research purposes.

Methods

A 23-item survey was developed and distributed to hcps at tumour board meetings, and a related 26-item survey was developed and distributed to oncology patients at the muhc Cedars Cancer Centre.

Results

The survey attracted participation from 73 hcps, including 37 attending physicians, and 102 oncology patients. Despite the fact that 88% of hcps rated their knowledge of rtd as none or limited, 42% indicated that they would feel comfortable discussing rtd with their cancer patients. Of the responding hcps, 67% indicated that their current knowledge of rtd would affect their decision to discuss such a program with patients, which implies the importance of education for hcps to facilitate enrolment of patients into a rtd program. Of responding patients, 78% indicated that they would not be uncomfortable if their doctor discussed rtd with them, and 61% indicated that they would like it if their doctor were to discuss rtd with them. The hcps and patients felt that the best time for patients to be approached about consenting to a rtd program would be at the transition to palliative care when no treatment options remain.

Conclusions

At the muhc, hcps and patients are generally enthusiastic about adopting a rtd program for patients with metastatic cancer. Education of hcps and patients will be an important determinant of the program's success.

Relevant Word Order Vectorization for Improved Natural Language Processing in Electronic Health Records

Electronic health records (EHR) represent a rich resource for conducting observational studies, supporting clinical trials, and more. However, much of the data contains unstructured text, presenting an obstacle to automated extraction. Natural language processing (NLP) can structure and learn from text, but NLP algorithms were not designed for the unique characteristics of EHR. Here, we propose Relevant Word Order Vectorization (RWOV) to aid with structuring. RWOV is based on finding the positional relationship between the most relevant words to predicting the class of a text. This facilitates machine learning algorithms to use the interaction of not just keywords but positional dependencies (e.g. a relevant word occurs 5 relevant words before some term of interest). As a proof-of-concept, we attempted to classify the hormone receptor status of breast cancer patients treated at the University of Kansas Medical Center, comparing RWOV to other methods using the F1 score and AUC. RWOV performed as well as, or better than other methods in all but one case. For F1 score, RWOV had a clear edge on most tasks. AUC tended to be closer, but for HER2, RWOV was significantly better for most comparisons. These results suggest RWOV should be further developed for EHR-related NLP.

A Novel Collateral Imaging Method Derived from Time-Resolved Dynamic Contrast-Enhanced MR Angiography in Acute Ischemic Stroke: A Pilot Study

BACKGROUND AND PURPOSE

Assessment of the collateral status has been emphasized for appropriate treatment decisions in patients with acute ischemic stroke. The purpose of this study was to introduce a multiphase MRA collateral imaging method (collateral map) derived from time-resolved dynamic contrast-enhanced MRA and to verify the value of the multiphase MRA collateral map in acute ischemic stroke by comparing it with the multiphase collateral imaging method (MRP collateral map) derived from dynamic susceptibility contrast-enhanced MR perfusion.

MATERIALS AND METHODS

From a prospectively maintained registry of acute ischemic stroke, MR imaging data of patients with acute ischemic stroke caused by steno-occlusive lesions of the unilateral ICA and/or the M1 segment of the MCA were analyzed. We generated collateral maps using dynamic signals from dynamic contrast-enhanced MRA and DSC-MRP using a Matlab-based in-house program and graded the collateral scores of the multiphase MRA collateral map and the MRP collateral map independently. Interobserver reliabilities and intermethod agreement between both collateral maps for collateral grading were tested.

RESULTS

Seventy-one paired multiphase MRA and MRP collateral maps from 67 patients were analyzed. The interobserver reliabilities for collateral grading using multiphase MRA or MRP collateral maps were excellent (weighted κ = 0.964 and 0.956, respectively). The agreement between both collateral maps was also excellent (weighted κ = 0.884; 95% confidence interval, 0.819-0.949).

CONCLUSIONS

We demonstrated that the dynamic signals of dynamic contrast-enhanced MRA could be used to generate multiphase collateral images and showed the possibility of the multiphase MRA collateral map as a useful collateral imaging method in acute ischemic stroke.