Deep learning performance compared to healthcare experts in detecting wrist fractures from radiographs: A systematic review and meta-analysis

OBJECTIVE

To perform a systematic review and meta-analysis of the diagnostic accuracy of deep learning (DL) algorithms in the diagnosis of wrist fractures (WF) on plain wrist radiographs, taking healthcare experts consensus as reference standard.

METHODS

Embase, Medline, PubMed, Scopus and Web of Science were searched in the period from 1 Jan 2012 to 9 March 2023. Eligible studies were patients with wrist radiographs for radial and ulnar fractures as the target condition, studies using DL algorithms based on convolutional neural networks (CNN), and healthcare experts consensus as the minimum reference standard. Studies were assessed with a modified QUADAS-2 tool, and we applied a bivariate random-effects model for meta-analysis of diagnostic test accuracy data.

RESULTS

Our study was registered at PROSPERO with ID: CRD42023431398. We included 6 unique studies for meta-analysis, with a total of 33,026 radiographs. CNN performance compared to reference standards for the included articles found a summary sensitivity of 92% (95% CI: 80%-97%) and a summary specificity of 93% (95% CI: 76%-98%). The generalized bivariate I-squared statistic indicated considerable heterogeneity between the studies (81.90%). Four studies had one or more domains at high risk of bias and two studies had concerns regarding applicability.

CONCLUSION

The diagnostic accuracy of CNNs was comparable to that of healthcare experts in wrist radiographs for investigation of WF. There is a need for studies with a robust reference standard, external data-set validation and investigation of diagnostic performance of healthcare experts aided with CNNs.

CLINICAL RELEVANCE STATEMENT

DL matches healthcare experts in diagnosing WFs, which potentially benefits patient diagnosis.

Nordic radiographers' and students' perspectives on artificial intelligence - A cross-sectional online survey

INTRODUCTION

The integration of artificial intelligence (AI) into the domain of radiography holds substantial potential in various aspects including workflow efficiency, image processing, patient positioning, and quality assurance. The successful implementation of AI within a Radiology department necessitates the participation of key stakeholders, particularly radiographers. The study aimed to provide a comprehensive investigation about Nordic radiographers' perspectives and attitudes towards AI in radiography.

METHODS

An online 29-item survey was distributed via social media platforms to Nordic students and radiographers working in Denmark, Norway, Sweden, Iceland, Greenland, and the Faroe Islands including items on demographics, specialization, educational background, place of work and perspectives and knowledge on AI. The items were a mix of closed-type and scaled questions, with the option for free-text responses when relevant.

RESULTS

The survey received responses from all Nordic countries with 586 respondents, 26.8% males, 72.1% females, and 1.1% non-binary/self-defined or preferred not to say. The mean age was 37.2 with a standard deviation (SD) of ±12.1 years, and the mean number of years since qualification was 14.2 SD ± 10.3 years. A total of 43% (n = 254) of the respondents had not received any AI training in clinical practice. Whereas 13% (n = 76) had received AI during radiography undergrad training. A total of 77.9% (n = 412) expressed interest in pursuing AI education. The majority of respondents were aware of the potential use of AI (n = 485, 82.8%) and 39.1% (n = 204) had no reservations about AI.

CONCLUSION

Overall, this study found that Nordic radiographers have a positive attitude toward AI. Very limited training or education has been provided to the radiographers. Especially since 82.8% reports on plans to implement AI in clinical practice. In general, awareness of AI applications is high, but the educational level is low for Nordic radiographers.

IMPLICATION FOR PRACTICE

This study emphasises the favourable view of AI held by students and Nordic radiographers. However, there is a need for continuous professional development to facilitate the implementation and effective utilization of AI tools within the field of radiography.

Radiation dose to multidisciplinary staff members during complex interventional procedures

INTRODUCTION

Complex interventional radiology procedures involve extensive fluoroscopy and image acquisition while staff are in-room. Monitoring occupational radiation dose is crucial in optimization. The purpose was to determine radiation doses received by staff involved in complex interventional procedures performed in a dedicated vascular or neuro intervention room.

METHODS

Individual real-time radiation dose for all staff involved in vascular and neuro-interventional procedures in adult patients was recorded over a one-year period using wireless electronic dosimeters attached to the apron thyroid shield. A reference dosimeter was attached to the C-arm near the tube housing to measure scattered, unshielded radiation. Radiology staff carried shoulder thermo-luminescent dosimeters with monthly read-out to monitor dose over time.

RESULTS

Occupational radiation dose was measured in 99 interventional procedures. In many cases prostate artery embolization procedures exposed radiologists to high radiation doses with a median of 15.0 μSv and a very large spread, i.e. 0.2-152.5 μSv. In all procedures except uterine fibroid embolization radiographers were exposed to lower doses than those of radiologists, with endovascular aortic repair being the procedure with highest median exposure to assisting radiographers, i.e. 2.2 μSv ranging from 0.1 to 36.1 μSv. Median radiation dose for the reference dosimeter was 670 μGy while median staff dose for all procedures combined was 3.2 μGy.

CONCLUSION

Radiation doses for multiple staff were determined and the ratio between staff dose and reference dosimeter indicated proper use of shielding in general. Some high-dose procedures may need further optimization for certain staff members, especially those not primarily employed in radiology.

IMPLICATIONS FOR PRACTICE

The study provides benchmark doses that may be used widely in audits and in the ongoing effort to optimize radiation protection for staff in interventional radiology.

Radiographers use of social media - SoMe in a Nordic perspective

INTRODUCTION

Social media (SoMe) is widely used as a communication platform in everyday life. Also, healthcare professionals have embraced SoMe as a communication tool for both peers and patients. It is becoming an interactive tool for discussing professionals' issues and a place where learning and education occur. This study explores the specific patterns of SoMe use for radiographers' in the Nordic countries. The aim of this survey was to investigate radiographers use of social platforms in a professional setting.

METHODS

A 29-item survey was prepared, and pilot-tested. The survey was produced in Danish a language that all Nordic countries master. In general, most Nordic languages are very similar. The survey was distributed by online platforms such as Facebook, LinkedIn, Twitter/X, and also distributed by newsletters by the Norwegian and Danish national radiographers societies. All data was collected anonymously. An Ethical Research approval was obtained from the University of Southern Denmark.

RESULTS

A total of 242 respondents completed the survey (Denmark n = 183, Norway n = 48, Sweden n = 8, and n = 3 from other Scandinavian countries). The respondents included 186 females, 52 males and four were undisclosed. On average, the respondents spent approximately 2 h and 23 min daily on SoMe, with 27 min specifically dedicated to content relevant to radiographers. Facebook was the preferred platform with 93 % (n = 226). A total of 5.4 % (n = 13) respondents had experienced contact from patients and/or next of kin, while 92 % (n = 222) reported no such interactions and 2.9 % (n = 7) were undisclosed. A total of 52.8 % (n = 128) used SoMe in relation to courses, conferences, or online meetings. This shows that time spent on content relevant to radiographers imply that SoMe can be a relevant tool for reaching radiographers.

CONCLUSION

The survey demonstrates radiographers' use of SoMe for personal and professional interest, with Facebook as the preferred social media platform. SoMe were mostly used during courses, conferences, or online meetings with half of the respondent reported using SoMe platforms during working hours. These results underscore the untapped potential of SoMe in professional healthcare settings. Additionally, the study offers insight into current practices, facilitating comparisons to identify trends in SoMe usage within the radiographer community.

IMPLICATIONS FOR PRACTICE

The findings advocate for the strategic use of SoMe by radiographers', emphasizing professional networking and knowledge sharing. However, clear guidelines are necessary to ensure patient confidentiality and data security in these digital interactions.

Repeatability of diffusion-based stiffness prediction - A healthy volunteer study

INTRODUCTION

The study investigated the repeatability of brain diffusion-based stiffness prediction (DWIstiff) in healthy volunteers.

METHODS

Thirty-one healthy volunteers were examined with DWIstiff using two different sets of b-values: b200-1500 s/mm2 (DWIstiff, 1500) and b200-1000 s/mm2 (DWIstiff, 1000). Each b-value set was scanned twice per imaging session without repositioning the participants. DWIstiff images were reconstructed from each set. Two observers delineated regions of interest (ROIs) on each DWIstiff image. The repeatability coefficient (RC), coefficient of variation (CV), inter- and intraobserver agreement were calculated.

RESULTS

After excluding three participants due to image artifacts, the study included twenty-eight volunteers (mean age (range)) 37 years (24-62), 10 males, 18 females). For DWIstiff, 1500, the lowest and the highest RCs were in the parietal lobe (0.52) and respectively the brain stem (1.17). The lowest RC for DWIstiff, 1000 was in the frontal lobe (0.42) and the highest in the brain stem (1.58). The CV for whole brain measurements was 3.83 % for DWIstiff, 1500 and 4.93 % for DWIstiff, 1000. The Bland‒Altman (BA) limits of agreement (LoA) for the intraobserver agreement of DWIstiff, 1500 were -0.90 to 1.06 and respectively -0.78 to 0.88 for DWIstiff, 1000. Regarding interobserver agreement, the LoA were -0.85 to 0.94 for DWIstiff, 1500 and -0.61 to 0.66 for DWIstiff, 1000.

CONCLUSION

DWIstiff is a precise technique with some observer dependence. Repeatability is higher for DWIstiff, 1000 s/mm2 than for DWIstiff 1500 s/mm2.

IMPLICATIONS FOR PRACTICE

Our findings suggest that DWIstiff can reliably detect stiffness changes larger than 4.93 % in healthy volunteers. Further studies should investigate whether the repeatability of DWIstiff may be affected by the presence of pathology such as a brain tumor.

Reporting radiographers within the European Federation of Radiographer Society (EFRS) member countries - motivation for becoming a reporting radiographer

INTRODUCTION

Radiographer-led reporting originated in the United Kingdom as a strategy to reduce reporting backlog and time taken to report images. The effectiveness of reporting radiographers has been demonstrated, but their motivational factors have not been thoroughly explored. This survey aims to understand the incentives for radiographers to pursue postgraduate education in reporting radiography across Europe.

METHODS

An online survey was conducted, collecting data across a range of topics such as demographic information, professional role, and job satisfaction. Questions assessing the influence of motivational factors on the decision to become a reporting radiographer are presented in this study. Descriptive statistics characterized the respondents' demographics. The motivational aspects were analysed quantitatively by regression analyses. Thematic analyses were performed for the free text responses on motivational aspects.

RESULTS

239 respondents from the UK, Denmark, Norway, Sweden, The Netherlands, Ireland, and Malta completed the survey's motivation section. Increased knowledge and new challenges were the most motivating factors for becoming a reporting radiographer, while less exposure to radiation and less patient contact were the least motivating factors. Job satisfaction was a significant motivator. Gender significantly correlated with the importance of social connections for female reporting radiographers. A cross-country comparison showed that title and position and job security were more important for reporting radiographers from the UK.

CONCLUSION

Taking in consideration that a sample of 239 is not generalisable for the role, this survey does provides insights into the motivation behind being a reporting radiographer in Europe. Factors such as increased knowledge, new challenges, and job satisfaction play significant roles. Hindrances experienced by reporting radiographers included lack of time, support, and standards, while aspirations for further professional development were expressed.

IMPLICATIONS FOR PRACTICE

A thorough understanding of the motivation behind pursuing postgraduate studies in reporting radiography is a valuable tool for managers, aiding in fostering a positive work environment and attracting/keeping qualified personnel. The findings of this study can be employed in the development of strategies to support and enhance the practice of reporting radiographers.

Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Reporting radiographers in Europe survey: Support, role satisfaction, and advanced clinical practice within the European federation of radiographer society (EFRS) member countries

INTRODUCTION

Increasing number of radiographers are undertaking image reporting throughout Europe. However, there are variations in practice and experience in European countries. The study aim was to investigate reporting radiographer's perceptions in relation to support for their role and workload satisfaction and elements of advanced practice that may also be undertaken.

METHODS

Following institutional ethical approval an online 34 item questionnaire survey was circulated via social media; Twitter, Facebook, and LinkedIn in a 12-week period in 2022 across Europe. The survey data were managed by the online secure database REDCap (Research Electronic Data Capture). Data was collected across a range of questions, of which those relating to support for, and barriers to radiographer reporting, role and job satisfaction, and other role elements are reported here.

RESULTS

A response level of 345 individual reporting radiographers replied to the survey from 15 European countries; some questions were optional and therefore had a lower response rate. There was consensus about the need for support from radiologists and management, protected time, and funding to support the reporting role. The majority of respondents received additional pay for taking on this role and expressed satisfaction with their role and workload. In relation to elements of advanced practice, the majority of respondents were involved in educational and managerial activities, and there was interest, but limited involvement, in research.

CONCLUSION

There was a consensus about the support needed, and perceived barriers to, radiographer reporting, between reporting radiographers from different countries. Whilst there is some commonality in relation to activities such as supervision and education, there was clearer variety in relation to opportunities for research between the respondents, perhaps reflecting the differences between reporting as a standalone role development and reporting as part of an advanced clinical practice role.

IMPLICATIONS FOR PRACTICE

As there is increasingly an emphasis on advanced clinical practice, reporting radiographers are likely to require support to develop their skills so that they can actively participate in the broader activities associated with this role, including education, leadership, and research.

Reporting radiographers in Europe survey: An overview of the role within the European Federation of Radiographer Society (EFRS) member countries

INTRODUCTION

Reporting radiographers undertake an important role in healthcare and for the radiographer profession in general. First introduced in the United Kingdom, reporting radiographers are now practicing in several other European countries. Our objective was to investigate the workforce of reporting radiographers across the European Federation of Radiographer Societies (EFRS) community.

METHOD AND MATERIAL

A voluntary anonymous 34 item electronic survey was distributed online using social media accounts such as Twitter, Facebook and LinkedIn covering a wide range of topics relating to professional role, advanced practice, education, and seniority. The questionnaire was distributed during a 12-week period in 2022.

RESULT

A total of 345 individual responses were received from 15 countries with majorities of respondent from United Kingdom (n = 245, 71%) and Denmark (n = 66, 19%). Mean age was 41.9 (S.D 9.8), similar for females, 42.5 (S.D 9.0) and men 40.9 years (S.D 9.7). Most reporting radiographers worked in public hospitals (90%). The vast majority of the respondents (n = 270, n = 94%) authored and signed their own clinical reports while a minority (n = 18, 6%) stated that their reports were checked by radiologists.

CONCLUSION

The survey highlights the scope of practice of reporting radiographers working in Europe. Reporting is becoming a career path for an increasing number of radiographers across Europe and there is assess to academic education and clinical support.

IMPLICATION FOR PRACTICE

Reporting radiographers fulfil an important role within the current demands of healthcare. This demand is likely to increase in the future, and therefore it is vital that there is some form of standardisation in the level of education that this group of healthcare professionals receive.

Genetic parameters for early piglet weight, litter traits and number of functional teats in organic pigs

Knowledge remains limited on genetic variation and genetic correlations for traits in sows and piglets that are reared in an organic or outdoor setting. Here, we estimated genetic variance components for individual piglet weight, litter weight, litter size traits, and number of functional teats in a pig population raised under outdoor organic conditions. Data were collected from the largest organic multiplier farm in Denmark. Individual piglet weight was recorded at birth and on day 10. Number of live and dead piglets were recorded at birth, day 4, and day 11. Mean and total litter weight were calculated based on the individual weight of living piglets at birth and on day 10. The estimated heritability was highest for the number of functional teats (0.49), mean weight of a litter at birth (0.33) and on day 10 (0.25). In contrast, heritability was lowest for litter size traits (0.04-0.08) and piglet weight (0.06-0.07). Maternal heritability was much higher for individual piglet weight than direct heritability. The results showed that selection for higher mean weight results in smaller litters. Also, selection for individual birth weight of piglets results in heavier piglets at 10 days. In conclusion, this study confirmed that there is genetic variation in individual piglet weight, litter traits, and number of functional teats in organically and outdoor-reared pigs.

Age-dependent genetic and environmental variance of semen quality in Nordic Holstein bulls

The aim of this study was to estimate genetic and environmental parameters, across bull's age, for semen quality traits including pre- and postcryopreservation semen concentration, sperm motility, and sperm viability as well as ejaculate volume and number of doses per ejaculate. A data set on 96,595 ejaculates from 2,831 Nordic Holstein bulls collected between 2006 and 2019 was used. Genetic and environmental parameters were estimated using a random regression model and applying the average-information REML approach. Spline functions were chosen to fit the additive genetic and permanent environmental effects across bull's age, and the optimal number of knots was chosen using cross validation. Residual variance heterogeneity was assumed in different bull age classes. The estimated repeatabilities of semen quality traits ranged from 0.16 to 0.85 across different ages of bulls. The estimated heritabilities of semen quality traits ranged from 0.02 to 0.56 across different ages of bulls. The results indicate possibilities for genetic improvement of semen quality traits through selective breeding.

Cyclin-dependent kinase 6 (CDK6) as a potent regulator of the ovarian primordial-to-primary follicle transition

Introduction: Ovarian follicle development requires tight coordination between several factors to initiate folliculogenesis to generate a mature and fertile egg. Studies have shown that cell cycle factors might contribute to follicle development, hover specific knowledge on individual CDKs and follicle activation has not been investigated. Among cell cycle regulators, CDK6 is a key player through binding to cyclin D resulting DNA synthesis and genome duplication. Interestingly, the CDK6 gene is differentially expressed in oocytes and granulosa cells from human primordial and primary follicles, which suggest a potential role of CDK6 in the primordial-to-primary transition. In this study, we investigated the potential regulatory role of CDK6 in progression of primordial to primary follicle transition using BSJ-03-123 (BSJ), a CDK6-specific degrader. Methods: In mouse ovarian in vitro culture, BSJ reduced the activation of primordial follicles, and reduced follicle development. As a next step, we examined the egg maturation read-out and found that BSJ-treated follicles matured to competent MII eggs with resumption of first meiosis, comparable with the control group. Results: Noteworthy, it appears that inhibition of CDK6 did increase number of apotoptic cells, articular in the granulosa cells, but had no impact on ROS level of cultured ovaries compared to control group, indicating that the cells were not stressed. Oocyte quality thus appeared safe. Discussion: The results of this study indicate that CDK6 plays a role in the primordial-to-primary transition, suggesting that cell cycle regulation is an essential part of ovarian follicle development.

Adherence and discontinuation of sglt2-inhibitors and glp1-r agonists in patients with type 2 diabetes with and without cardiovascular disease

Background

Sodium-glucose cotransporter-2 (SGLT2) inhibitors and glucacon-like-peptide-1 receptor (GLP-1R) agonists are two novel therapies in type 2 diabetes (T2D) that are recommended in patients with manifestations of cardiovascular disease or high risk of cardiovascular disease due to their cardioprotective benefits. Despite the increasing use of these drugs, there is still limited knowledge on the adherence patterns and the risk of discontinuation, according to the presence or absence of different cardiovascular conditions.

Purpose

To investigate the adherence and estimate the risk of discontinuation of SGLT2 inhibitors and GLP1-R agonists in patients with T2D with and without cardiovascular disease.

Methods

From Danish nationwide registers, we included all individuals >40 years with T2D who redeemed the first prescription of a SGLT2 inhibitor or GLP1-R agonist, between December, 2012 and December, 2018. Patients were divided into subgroups according to the presence or absence of different cardiovascular conditions (heart failure, ischemic heart disease, peripheral artery disease, atrial fibrillation), at the time of inclusion. Adherence over the course of one year after initiation of treatment was estimated by the proportion of days covered (PDC) for each subgroup, and adherence was defined as PDC 80%. The risk of discontinuation was estimated using multivariable cause-specific Cox regression models, and was defined as a break in treatment of 90 days. The Aalen-Johansen estimator was used to account for censoring and competing risks. Patients were followed until date of emigration, death or study end (December 31, 2019).

Results

We included 24,061 patients with T2D who initiated treatment with a SGLT2 inhibitor, and 13,899 patients with T2D who initiated treatment with a GLP1-R agonist, for the first time between December 10, 2012 and December 31, 2018. Median age at inclusion was 62 years (IQR 54–70) and 40% were female. In the analyses, 67% of the patients treated with SGLT2 inhibitors were adherent to therapy throughout the first year, whereas the same proportion of patients, 67%, were adherent to therapy with GLP-1R agonists. Mean PDC was 77% (SD 33) and 79% (31) for patients in therapy with SGLT2 inhibitors and GLP1-R agonists, respectively. No significant difference was observed related to the presence or absence of cardiovascular disease (SGLT2 inhibitor: mean PDC 77 (33) vs. 77 (33), GLP1-R agonist: 78 (32) vs. 79 (31)).

Conclusions

In this nationwide cohort study, we found that patients with T2D who initiated therapy with a SGLT2 inhibitor and those who initiated therapy with a GLP1-R agonist were almost equally adherent to therapy throughout the first year. Adherence in both treatment groups did not differ according to the presence or absence of cardiovascular disease.

Funding Acknowledgement

Type of funding sources: None.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Trans-stenotic pressure gradient as derived from CT improves patient management: ADVANCE registry

Background

The change in fractional flow reserve derived from CT (FFRCT) value across a coronary stenosis (ΔFFRCT) improves the physiological characterization of coronary artery disease (CAD). The role of ΔFFRCT in guiding risk-stratification and downstream testing in patients with stable CAD is unknown.

Purpose

To investigate the incremental value of ΔFFRCT at predicting early revascularization and improving efficacy of resource utilization.

Methods

Patients with CAD on CT coronary angiography (CTCA) were enrolled in an international multicenter registry. Patients with non-evaluable FFRCT analysis were excluded. The CTCA was assessed for: stenosis severity as per CAD-Reporting and Data System (CAD-RADS), lesion length and lesion-specific FFRCT measured 2 cm distal to stenosis. Risk factors and actual treatment (revascularization vs medical therapy) at 90-day follow-up were recorded. Multivariable logistic regression analysis for early revascularization was conducted. The incremental discrimination for revascularization prediction was compared among 3 models (model 1: risk factors + lesion length and location + CAD-RADS; model 2: model 1 + lesion-specific FFRCT; model 3: model 2 + ΔFFRCT). Simulating ICA referral for patients with CAD-RADS ≥3 and lesion-specific FFRCT ≤0.8, the potential impact of ΔFFRCT at reducing ICA referral and improving the ratio of subsequent revascularization was assessed.

Results

Of 4730 patients (66±10 years; 34% female), 2092 (42.7%) underwent ICA and 1168 (24.7%) underwent early revascularization. With increasing ΔFFRCT, a higher incidence of revascularization (Figure 1A) and an increase in the revascularization to ICA ratio was observed (Figure 1B). ΔFFRCT >0.13 was the optimal cut-off for predicting revascularization as determined by the Youden index. ΔFFRCT remained an independent predictor for early revascularization (odds ratio per 0.05 increase with 95% CI, 1.31 [1.26–1.35]; p<0.0001) after adjusting for risk factors, CAD-RADS, lesion length and location, and FFRCT. Among the 3 models, model 3, which included ΔFFRCT showed the highest AUC and improved discrimination power compared to model 2 (0.87 [0.86–0.88] vs 0.85 [0.84–0.86]; p<0.0001] (Figure 2), with the greatest incremental value for ΔFFRCT observed in patients with lesion-specific FFRCT between 0.71–0.80. In patients with CAD-RADS ≥3 and lesion-specific FFRCT ≤0.8, a diagnostic strategy incorporating ΔFFRCT >0.13 would potentially reduce ICA referral by 32.2% (1638 to 1110) and improve the revascularization to ICA ratio from 65.2% [1068/1638] to 73.1% [811/1110].

Conclusions

The characterization of CAD with ΔFFRCT improves the identification of patients requiring early revascularization as compared to a standard diagnostic strategy of CTCA with FFRCT, particularly for those with lesion-specific FFRCT of 0.71–0.80. ΔFFRCT has the potential to aid decision making for ICA referral and improve the efficiency of resource utilization.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): HeartFlow, Inc., Redwood City, CA, USA ΔFFRCT and actual treatmentROC curve for early revascularization

Resting and exercise hemodynamic determinants of daily activity measured by accelerometer in stable heart failure patients

Background

Patient-worn accelerometer is increasingly used in patients with heart failure and reduced ejection fraction (HFrEF) to assess daily activity and and as surrogate endpoint. We examined the association between cardiac physiology and daily activity by patient-worn accelerometer recordings in stable HFrEF patients.

Methods

In this descriptive study, physical average daily accelerometer units (PADA) and total average daily accelerometer unit (TADA) were assessed by a accelerometer recordings. Sixty three stable ambulatory patients with HFrEF, mainly men (92%), mean age 58±10 years, and ejection-fraction 26±4% underwent hemodynamic exercise testing, and accelerometry (Table 1). Patients were divided by PADA in a low and high activity level groups based on counts per minute physical activity.

Results

Patients in the low activity group were older and more frequently treated with diuretics. At rest, the low activity group was characterized by a lower cardiac index (CI) (2.2±0.4 vs. 2.4±0.4 l/min/m2, p=0.01), Stroke volume (SV) (70±19 vs. 81±17 ml, p=0.02) but not pulmonary capillary wedge pressure (PCWP) (12±5 vs. 11±5 mmHg, p=0.3) (Figure 1). Low activity group reached a lower CI (4.8±1.7 vs. 6.6±1.7 l/min/m2, p<0.001) and SV (94±32 vs. 121±29 ml, p<0.001), but not in PCWP (31±12 vs. 27±8 mmHg, p=0.2) or arterial-venous O2 content difference (A-VO2 diff) (13.00±2.32 vs. 12.96±1.65 ml O2/dl, p=0.9) at peak exercise. The attenuated increase was associated with attenuated increase in SV rther than increase in heart rate (42±23 vs. 52±21 bpm, p=0.07). Finally, CI at peak exercise was the only independent variable associated with PADA after adjusting for age, gender, and BMI (p<0.0001). The PADA and TADA were associated to functional assessments using Kansas City Cardiomyopathy Questionnaire, but not with New York Heart Association class or N-terminal pro brain natriuretic peptide (NT-proBNP) (Table 1).

Conclusion

Accelerometer-assessed activity in patients with HFrEF are associated with impairments in LV performance, SV reserve and cardiac output during exercise, to a greater extent than changes in arterial-venous O2 content difference or pulmonary vascular pressures. Accelerometer data may provide information about the functional status that we do not nessecary find in the widely used tools in both research and daily clinical practice.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): This work was supported by the Danish Heart Foundation [grant numbers 17-R116-A7714-22076, 18-R124-A8573-22107]; Steno Diabetes Center Odense, Denmark [grant number 3363] and A.P. Møller Foundation for the Advancement of Medical Science [grant number 17-L-0339]. Table 1. Baseline and regression analysisFigure 1. Change in PCWP and CI by exercise

Effect of empagliflozin in hfref patients treated with angiotensin receptor neprilysin inhibitor an analysis of EMPIRE HF

Introduction

Inhibition of neprilysin/valsartan (ARNi) or sodium glucose cotransporter 2 (SGLT2) in patients with heart failure (HF) and reduced ejection fraction (HFrEF) has been shown to reduce the risk of Cardiovascular death and hospitalization for HF. Recent trails suggested that SGLT2 reduces the risk for cardiovascular death or hospitalization for HF, regardless of underlying ARNi treatment and that the effect may even be greater in those receiving the combination. Whether there exist an interaction between effect of ARNi and SGLT2 on functional endpoints related to mechanism of action is unknown.

Purpose

This post-hoc analysis of the randomized double-blinded Empire HF trial evaluated the influence of ARNi on the effect of the SGLT2 Empagliflozin on N-terminal prohormone B-type natriuretic peptide (NT-proBNP), pulmonary capillary wedge pressure (PCWP), Left ventricular end-systolic and end-diastolic volumes index; (LVESVI) (LVEDVI), left atrial volume index (LAVI), Left ventricular ejection fraction (LVEF), and Kansas City Cardiomyopathy Questionnaire (KCCQ) HFrEF patients.

Methods

Empire HF trial randomized 190 patients with HFrEF (LVEF ≤40%) to placebo or empagliflozin (10 mg/day), on top of recommended treatment for HFrEF, for 12 weeks of treatment. A total of 58 (31%) received ARNi at baseline and no patients initiated ARNi during study period.

Results

Patients on ARNi were well-treated with a similar baseline characteristic as those who were not treated with ARNi (Table 1). Patients with ARNi had a lower systolic blood pressure (P=0.01), with a higher NT-proBNP (P<0.001) when compared with those not receiving ARNi. When compared to placebo, empagliflozin did not reduce the ratio of change of NT-proBNP with or without ARNi (0.94 [95% CI, 0.75 to 1.19] pg/ml; P=0.62) and (1.02 [95% CI, 0.86 to 1.22] pg/ml; P=0.78), respectively, adjusted (age, atrial fibrillation) interaction P=0.57. Empagliflozin reduced PCWP regardless of ARNi treatment (with ARNi; −4.9 [95% CI, −9.1 to −0.6] mmHg; P=0.02) and (without ARNi; −2.1 [95% CI, −3.8 to −0.4] mmHg; P=0.01), adjusted interaction P=0.20. Overall, empagliflozin was associated with a reduction in LVESVI, LVEDVI, and LAVI volumes, but no effect on LVEF. However, Empagliflozin combined with ARNi at baseline, significantly reduced LVEDVI (−11.2 [95% CI, −21.2 to −1.2] ml/m2; P=0.03), but not without ARNI (−2.9 [95% CI, −8.7 to 2.9] ml/m2; P=0.32), adjusted interaction P=0.13. Treatment-by-subgroup interaction P-values for LVESVI, LAVI, and LVEF analysis were >0.05 (Figure 1). KCCQ total symptom score were significantly increased in those not receiving ARNi (5.4 [95% CI, 1.1 to 9.6]; P=0.013), but not with ARNi (−4.0 [95% CI, −10.3 to 2.3]; P=0.22), adjusted P=0.02.

Conclusion

In this post hoc analysis the effects on empagliflozin to reduce PCWP and LV volumes were not diminished in patients receiving ARNi, however KCCQ change were diminished in patients receiving ARNi.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): This work was supported by the Danish Heart Foundation [grant numbers 17-R116-A7714-22076, 18-R124-A8573-22107]; Steno Diabetes Center Odense, Denmark [grant number 3363] and A.P. Møller Foundation for the Advancement of Medical Science [grant number 17-L-0339]. Table 1. Baseline characteristicsFigure 1. Change in echo variables +/− ARNi

There's nothing plain about projection radiography! A discussion paper

OBJECTIVES

Unlike the technological advances in cross-sectional imaging, the adoption of CR and DR has been relatively overlooked in terms of the additional radiographer skills and competences required for optimal practice. Furthermore, projection radiography is often referred to as basic, plain or other words suggesting simplicity or entry-level skill requirements. Radiographers' professional identity is connected with the discourse expressed via the language used in daily practice and consequently, if the perception of projection radiography is regarded as simple practice not requiring much reflection or complex decision-making, apathy and carelessness may arise. The purpose of this narrative review was to raise projection radiography from its longstanding lowly place and re-position it as a specialist imaging field.

KEY FINDINGS

Danish pre-registration radiography curricula contain little mention of projection radiography and a low proportion (n = 17/144; 11.8%) of Danish radiography students chose to focus on projection radiography within publicly available BSc. theses between 2016 and 2020 as compared to topics related to CT and MRI (n = 60/144; 41.7%).

CONCLUSION

By changing how we as the profession perceive the role and position of projection radiography, we can start to rebuild its lost prestige and demand a greater, more detailed and clinically relevant educational offering from academic partners. For this to commence, the language and terminology we use to describe ourselves and tasks undertaken must reflect the complexity of the profession.

IMPLICATIONS FOR PRACTICE

Regardless of imaging modality, every patient should be assured that a radiographer with expertise in acquiring images of diagnostic quality undertakes their examination. Reclaiming the prestige of projection radiography may lead students and radiographers to recognize projection radiography as a demanding specialist field for the benefit of the patients.

Rare variants in HCN4 identified in the general population are associated with complete atrioventricular (AV) block, 1. degree AV block and bundle branch block, results from 50.000 exomes

Background/Introduction

Cardiac conduction disorders cover disorders such as atrioventricular (AV) block and bundle branch block. Genome-wide association studies have identified more than 100 genetic loci for atrial fibrillation, including HCN4 loci associated with duration of the PR interval, a proxy for AV dysfunction. Recent candidate studies suggest an association between HCN4 variants and AV-block.

Purpose

We seek to determine the contribution of rare genetic variants in HCN4 to complete AV-block, 1. degree AV-block and bundle branch block (BBB) in the general population.

Methods

The UK Biobank is a population-based study of 500 000 individuals including a subset with genome-wide genotyping and exome sequencing (n=45,596). In this case-control study, we included persons of genetically determined white-European ancestry and analyzed their exome data. Analyses were performed using a logistic mixed-effects model. A gene-based burden analysis and single variant test were performed to examine the relationship between HCN4 variants and complete AV-block, 1. degree AV-block and BBB in the general population.

Results

The study included 43,371 persons. In an analysis of the HCN4 genes a significant association between rare variants (MAF<0.01) in HCN4 gene was found (complete AV-block, P=2.5x10–5, 1. degree AV-block, P=1.3x10–3 and BBB, P=0.01) (Figure 1A). The association to complete AV block was mostly driven by the variants Ser835Phe (P=2.7e-3), Glu153Gly (P=3.5e-3) and Arg378Cys (P=6.3e-3) (Figure 1B).

Conclusions

Rare HCN4 variants contribute to the risk of complete AV-block, 1. degree AV-block and BBB in the general population. These HCN4 variants seem to confer a substantial penetrance. Clinical screening for some of these variants seems appropriate.

Figure 1

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Hallas Møller - Novo nordisk

Utilization and outcomes of rotational atherectomy in Sweden

Aim

To evaluate utilization and outcomes of rotational atherectomy (RA) using data from the Swedish Coronary and Angioplasty Registry (SCAAR)

Methods

We included 1476 patients with 2218 lesions who underwent RA from 2005 to 2016. To study temporal changes, the study period was divided into three equal time-periods, period A, B and C.

Results

Although the number of RA procedures increased 3-fold from 2005 to 2016, the rate of RA (of all PCI procedures) remained low (0.5% vs 1.2% in 2005 vs 2016). RA patients consisted a high-risk group, with advanced age and clustering of comorbidities. Over time, included patients were older and had a higher risk profile. Trans-radial access, drug eluting stent (DES) use and use of intravascular imaging significantly increased from period A to C whereas positioning of a temporary pacemaker or intra-aortic balloon pump declined. Unfractionated heparin became the main anticoagulant (52 vs 87%) and use of glycoprotein IIb/IIIa inhibitors declined (31 vs 12%, in period A vs C). Following RA, 11% of lesions were treated without stent (15 vs 15 vs 8%, in period A, B and C) (Rota-only). In lesions treated with a stent, a bare metal stent (BMS) was implanted in 39% vs 12% vs 2% and a new generation DES (N-DES) in 5 vs 75 vs 97% (period A vs B vs C) of lesions.

The 3-year cumulative rate of restenosis was 6.7% (122 events), (11.1 vs 7.1 vs 4.1% in period A vs B vs C). As compared to DES, rota-only (adjusted HR 2.71; 95% CI 1.69- 4.36) and BMS (adjusted HR 3.63; 95% CI 2.27- 5.81) were associated with significantly higher risk for restenosis. First generation DES were associated with numerically higher but not significantly different risk for restenosis as compared to N-DES (adjusted HR 1.31; 95% CI 0.74- 2.31).

The 3 year cumulative rate of major adverse cardiac events (MACE), including death, myocardial infarction (MI) or any restenosis was 30.6% (34.2 vs 31.4 vs 28.2%, in period A vs B vs C) and the corresponding numbers for all-cause mortality were 18.1% (18.9 vs 18.4 vs 17.0%). After adjustment for baseline characteristics and angiographic findings, RA in period A was associated with higher risk for MACE as compared to period C (adjusted HR 1.40; 95% CI 1.09- 1.79), due to higher risk for MI and restenosis. The difference disappeared when procedural characteristics, including DES use, were added to the model.

The rate of major in-hospital complications was 7.0%, including in-hospital death 1.3%, periprocedural MI 2.8%, perforation 1.1%, cardiac tamponade 0.7%, stroke 0.2% and major bleedings 2.1%. We found no significant differences over time.

Conclusion

During the studied period, RA remained a rare procedure, utilised in a highly selected population. Over time a declining rate of restenosis and MI after RA was observed, a finding that appeared to be mainly driven by an increased use of DES. The rate of major in-hospital complication remained low.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Boston Scientific International

Bayesian estimation of genetic variance and response to selection on linear or ratio traits of feed efficiency in dairy cattle

This study aimed to estimate genetic parameters of the linear trait genetic residual feed intake (RFI) and the ratio traits feed conversion ratio (FCR) and feed conversion efficiency (FCE) along with dry matter intake (DMI) and energy sink traits such as energy-corrected milk (ECM), body weight (BW), body condition score (BCS), and BW change (BWC) across different weeks in the first lactation of Danish Holstein cows. A second objective was to conduct a Bayesian analysis of direct and correlated superiority of the selected group when selecting on genetic RFI, FCR, or FCE. Feed intake and energy sink traits were recorded during wk 1 to 44 of lactation on 847 primiparous Danish Holstein cows. A Bayesian multivariate random regression animal model was used to analyze DMI, ECM, BW, and BCS in different weeks of lactation. Genetic RFI was obtained by conditioning DMI on ECM, BW, BCS, and BWC using genetic partial regression coefficients. The posterior distribution of the breeding values for FCR and FCE was derived from the posterior distribution of functions of "fixed" environmental effects and random additive genetic effects on DMI and ECM. Genetic superiority of the selected group was defined as the difference in additive genetic mean of the selected top individuals expected to be potential parents, and the total population after integrating genetic trends out of the posterior distribution of selection responses. Posterior means of heritability of genetic RFI ranged from 0.10 to 0.15, genetic variance of FCR and FCE ranged from 2.13 × 10^-3 to 3.2 × 10^-3 (kg² DMI/kg² ECM) and 6.11 × 10^-3 to 2.4 × 10^-2 (kg² ECM/kg² DMI), respectively. Selection against RFI showed a direct response of -1.01 to -2.23 kg/d RFI and correlated responses of -0.031 to -0.056 kg/kg for FCR, 0.104 to 0.160 kg/kg for FCE, and -0.316 to -1.057 kg/d for DMI in different weeks of lactation. Selection against RFI had no significant effect on production traits but selection for ratio traits reduced BW and BCS. Posterior means of genetic correlation between DMI and ratio traits were low. In conclusion, the Bayesian procedure allowed us to estimate genetic RFI without the need for separate multiple regression analysis and considered the non-normal posterior distribution of ratio traits. Selection against genetic RFI might be an effective means to improve feed efficiency compared with ratio traits for feed efficiency in dairy cattle.

P2238Prognostic value and incremental benefit of ischaemic myocardial burden subtended by non-invasive CT-derived fractional flow reserve (FFRCT) significant stenoses

Background

Fractional flow reserve derived from CT-coronary angiography (FFRCT) accurately identifies ischaemic vessels which may be associated with clinical outcomes. Its predictive value in grey zone FFRCT values between 0.7–0.8 is not defined. The technique permits estimation of burden of ischaemic myocardium subtended by FFRCT significant vessels.

Purpose

To evaluate the prognostic value and incremental benefit of FFRCT defined ischaemic myocardial burden when compared to FFRCT alone.

Methods

This is a subanalysis of NXT (Analysis of Coronary Blood-Flow Using CTA:Next-Steps), a prospective study of stable coronary artery disease (CAD) patients referred for invasive angiography (ICA) undergoing invasive FFR, CTA and FFRCT in whom treating physicians had been blinded to FFRCT results. Primary endpoint, defined as a composite of non-fatal myocardial infarction and any revascularisation, was determined in 206 patients (age 64±9.5 years, 64% male) and 618 vessels. Burden of ischaemic myocardium was defined as percentage of myocardium subtended beyond the point at which a vessel's FFRCT becomes ≤0.8 as estimated by APPROACH score (FFRCT-APPROACH). In significant FFRCT vessels, the predictive value and incremental benefit of FFRCT-APPROACH was compared with significant FFRCT (≤0.8) for primary endpoint as measured by area under the receiver operator characteristic curve (AUC). Significant ischaemic myocardial burden was defined as >10%. The incidence and relationship between the primary endpoint with each 10% increase in FFRCT-APPROACH and 0.05-unit decrease in FFRCT values ≤0.8 was determined.

Results

Significant FFRCT was identified in 52.9% of patients (109/206) and 29.3% of vessels (181/618). At 4.7 years median follow-up the incidence of the primary endpoint in vessels with significant FFRCT-APPROACH was 58.9% (96/163) which was comparable with vessels with significant FFRCT (55.2%,100/181; P=0.50). The predictive value of FFRCT-APPROACH for the primary endpoint was comparable with FFRCT (AUC 0.72 [95% CI 0.65–0.79] vs 0.71 [0.63–0.78], P=0.79). When combined, there was significant predictive improvement compared with FFRCT alone (AUC 0.77 [0.70–0.84]; P=0.01). The largest incremental benefit upon FFRCT was observed in vessels with FFRCT values in the grey zone between 0.70–0.80 (AUC 0.76 [0.65–0.86] vs 0.62 [0.48–0.74]; P<0.01). Each 10% increase in FFRCT-APPROACH (Adjusted-HR 1.36; 95% CI 1.16–1.60; P<0.001) and each 0.05-unit FFRCT decrease (Adjusted-HR 1.42; 1.19–1.70; P<0.001) were independently associated with significant increase in the incidence of the primary-endpoint.

Conclusion

In patients with stable CAD referred for ICA, the burden of ischaemic myocardium subtended by FFRCT significant vessels predicted non-fatal myocardial infarction and future revascularisation. This provided significant incremental benefit when used in combination with FFRCT particularly at FFRCT values in the grey zone between 0.7 to 0.8.

P4449Incident cardiovascular disease in patients with type 2 diabetes: Established cardiovascular disease versus traditional risk markers

Background/Introduction

It is well established that patients with both T2D and established cardiovascular disease (CVD) are at high-risk of a re-event and should be treated with either a glucagon-like peptide-1 (GLP-1) analogue or a sodium-glucose transporter-2 (SGLT-2) inhibitor. Other high-risk patients with T2D may also benefit from these treatments. Whether traditional risk markers can identify patients with T2D without CVD with a similar incidence of CVD events as patients with T2D with established CVD is unknown.

Purpose

To compare the CVD incidence in patients with T2D with and without established CVD, stratified according to mid-regional pro-atrial natriuretic peptide (MR-proANP), albuminuria, electrogardiogram (ECG), echocardiography and age, to identify patients without established CVD who are at high risk of a CVD event.

Methods

In this prospective cohort study, patients with T2D (n=921) from a specialized diabetes clinic were examined at baseline regarding the different risk markers. Increasing cut-offs for MR-proANP were analysed to identify high-risk patients. Albuminuria included both micro- and macroalbuminuria. An abnormal ECG was defined as the presence of ST-/T-changes, bundle branch block or atrial fibrillation, and an abnormal echocardiography was defined as either heart failure with preserved (HFpEF) or reduced (HFrEF) ejection fraction. Established CVD was reported at baseline as prior myocardial infarction, coronary revascularization, cerebrovascular disease or peripheral artery disease. Information regarding CVD events was retrieved through national registers and a CVD event was similarly defined as established CVD, but in addition also included hospitalisation for heart failure and CVD death.

Results

In total, 224 (24%) patients had established CVD at baseline. Median [interquartile range] of follow-up was 4.7 [4.0–5.3] years. The incidence of CVD events among patients with established CVD was 95.7 per 1000-person years. Using a cut-off for MR-proANP of 190 pmol/l revealed that patients with a value above had similar incidence (93.9 per 1000-person years) and was found in 47 of 697 (6.7%) patients without CVD. In contrast, patients without CVD and with albuminuria (146 of 685 (21.3%) patients) or abnormal ECG (147 of 679 (21.6%)) or abnormal echocardiography (221 of 618 (35.7%)) or an age>65 years (335 of 697 (35.7%)) had substantial lower incidence (47.1, 35.1, 32.7 and 33.7 per 1000-person years, respectively).

Kaplan-Meier curves

Conclusion(s)

In patients with T2D without established CVD, using a range of traditional risk markers, we were only able to identify a subgroup of patients with MR-proANP values above 190 pmol/l who had a similar high incidence of CVD as T2D patients with established CVD. This subgroup may benefit from treatment with a GLP-1 analog or a SGLT-2 inhibitor. In contrast, the presence of other traditional risk markers in T2D was not associated with risk of incident CVD similar to patients with established CVD.

Acknowledgement/Funding

Thermo Fisher Scientific (Germany) funded the MR-proANP kits

Primary health care: an opportunity for early identification of people living with undiagnosed HIV infection

OBJECTIVES

We aimed to determine the fraction of HIV-diagnosed individuals who had primary health care (PHC) contacts 3 years prior to HIV diagnosis and whether the risk of HIV diagnosis and degree of immunodeficiency were associated with the frequency of visits or procedures performed.

METHODS

We used data from national registries to conduct a population-based nested case-control study. Cases were individuals diagnosed with HIV infection in Denmark from 1998 to 2016. Population controls were extracted from the general population matched 13:1 on gender and age. We used conditional logistic regression. As there was a statistically significant interaction, analyses were further stratified by gender and Danish/non-Danish origin.

RESULTS

We identified 2784 cases and 36 192 controls. Ninety-three per cent of cases and 88% of controls attended PHC at least once in the 3 years prior to diagnosis, with a higher median number of visits to PHC (NVPC) for cases. We found a statistically significant positive association between NVPC and risk of subsequent HIV diagnosis in men and non-Danish women. A U-shaped association between NVPC and risk of HIV diagnosis among Danish women. No substantial association between NVPC and degree of immunodeficiency was found. Risk of HIV diagnosis and degree of immunodeficiency were weakly associated with type of procedures performed.

CONCLUSIONS

For most HIV-infected individuals, there seem to be many opportunities for earlier diagnosis in PHC. In men and non-Danish women, the risk of HIV diagnosis but not the degree of immunodeficiency was related to NVPC. The results suggest that the type of medical procedure performed cannot not be used as a guide by the primary physician to indicate which patients to test.

Short communication: Multivariate outlier detection for routine Nordic dairy cattle genetic evaluation in the Nordic Holstein and Red population

It is of practical importance to ensure the data quality from a milk-recording system before use for genetic evaluation. A procedure was developed for detection of multivariate outliers based on an approximation for Mahalanobis distance and was implemented in the Nordic Holstein and Red population. The general target of this procedure is based on the Nordic Cattle Genetic Evaluation yield model, which is a 9-trait model for milk, protein, and fat in the first 3 lactations. The procedure is based on the phenotypic correlation structure as a function of days in milk (DIM) and on computation of trait means and standard deviations within a production year, lactation, and DIM. For each record in the data, a Mahalanobis distance value was computed based on the trait mean and the covariance matrix for the actual production year, lactation, and DIM. A set of cutoff values, ranging from 10 to 100 with steps of 10, for discarding multivariate outliers was investigated. Prediction accuracy was calculated as the Pearson correlations between estimated breeding values predicted by full data set and estimated breeding values predicted by reduced data set for cows without records in the reduced data set and with 1 or more records deleted due to the editing rules on Mahalanobis distance. The results showed that, averaged over all scenarios, gains of 0.005 to 0.048 on prediction accuracy have been obtained by deleting the multivariate outliers. The improvements were more profound for progeny of young bulls compared with progeny of proven bulls. It is easy to implement this multivariate outlier-detection procedure in the routine genetic evaluation for different dairy cattle breeds; however, an optimal cutoff value for Mahalanobis distance needs to be defined to achieve an acceptable compromise between genetic evaluation accuracy and data deletion.

Vorkommen von Ehrlichia canis bei Hunden in Deutschland?

Gegenstand und Ziel: Retrospektive Untersuchung von Hunden auf eine autochthone Infektion mit E. canis in Deutschland. Material und Methode: In die Studie gingen 111 Hunde ein, die sich in eine symptomatische (n = 49) und eine asymptomatische (n = 62) Gruppe unterteilten. Bei allen Hunden erfolgten eine Antikörperbestimmung gegen Ehrlichia canis mittels Immunfluoreszenztest im Serum und ein Direktnachweis von Ehrlichia und Anaplasma spp. mittels PCR aus EDTA-Vollblut. Ausschlusskriterien waren ein Auslandsaufenthalt sowie die Vorbehandlung mit Tetrazyklinen, Chloramphenicol oder Imidocarb. Ergebnisse: Niedrige IFT-Antikörpertiter gegen E. canis konnten bei sieben Hunden (6,3%) festgestellt werden. Sechs Hunde gehörten der symptomatischen und ein Hund der asymptomatischen Gruppe an. Gleichzeitig wurden bei vier dieser Hunde sehr hohe und bei einem ein moderater Antikörpertiter gegen Anaplasma phagocytophilum gefunden. Das PCR-Screening für Ehrlichia und Anaplasma war lediglich in zwei Fällen positiv. Beide Male ließ sich A. phagocytophilum nachweisen. Schlussfolgerungen: Nur bei zwei für E. canis seropositiven Hunden konnten keine Kreuzreaktionen mit A. phagocytophilum nachgewiesen werden. Da ein Direktnachweis bei diesen zwei Hunden nicht möglich war, ist eine tatsächliche Infektion mit E. canis fraglich. Die Gefahr der autochthonen Infektion von Hunden mit E. canis in Deutschland scheint somit gering zu sein, ist aber nicht ausgeschlossen. Klinische Relevanz: Bei unspezifischen Symptomen wie Apathie, Fieber und Inappetenz sowie Laborveränderungen in Form von Anämie und/oder Thrombozytopenie sollte deshalb auch bei Hunden, die Deutschland nicht verlassen haben, an eine Infektion mit E. canis gedacht werden.

The value of a new cardiac magnetic resonance imaging protocol in Myocardial Infarction with Non-obstructive Coronary Arteries (MINOCA) - a case-control study using historical controls from a previous study with similar inclusion criteria

Background

Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA) is common with a prevalence of 6% of all patients fulfilling the diagnosis of myocardial infarction. MINOCA should be considered a working diagnosis. Cardiac Magnetic Resonance (CMR) imaging has recently been suggested to be of great value to determine the cause behind MINOCA. The objectives of this paper are to describe the rationale behind the second Stockholm Myocardial Infarction with Normal Coronaries (SMINC-2) study and to discuss the protocol for investigation of MINOCA patients in the light of the recently published position paper from the European Society of Cardiology.

Methods

The SMINC-2 study is an open non-randomised study using historical controls for comparison. The primary aim is to prove that MINOCA patients investigated with the latest CMR imaging technique can achieve a diagnosis in 70% of all cases entirely by imaging. By including 150 patients we will have >80% chance to prove that the diagnostic accuracy can be improved by 20 absolute % with a p-value of less than 0.05 when compared with CMR imaging in the SMINC-1 study. Furthermore, in addition to invasive coronary angiography, coronary arteries are evaluated by computed tomography angiography to investigate coronary causes and questionnaires are used to describe Quality-of-Life (QoL). By January 1st 2017, 75 patients have been included.

Discussion

Whether CMR imaging can provide a diagnosis to an adequate proportion of MINOCA patients is unknown. Well-defined inclusion and exclusion criteria will be used to compare a MINOCA cohort from the population with an appropriate control group. Positive results are likely to influence future guidelines of the management of MINOCA. Furthermore, the study will give mechanistic insights into MINOCA in particular in patients with “true” myocardial infarction and describe QoL in this vulnerable group of patients.

Trial registration

Clinical Trials NCT02318498.

Joint analysis of longitudinal feed intake and single recorded production traits in pigs using a novel Horizontal model

A novel Horizontal model is presented for multitrait analysis of longitudinal traits through random regression analysis combined with single recorded traits. Weekly ADFI on test for Danish Duroc, Landrace, and Yorkshire boars were available from the national test station and were collected from 30 to 100 kg BW. Single recorded production traits of ADG from birth to 30 kg BW (ADG30), ADG from 30 to 100 kg BW (ADG100), and lean meat percentage (LMP) were available from breeding herds or the national test station. The Horizontal model combined random regression analysis of feed intake (FI) with single recorded traits of ADG100, LMP, and ADG30. In the Horizontal model, the FI data were horizontally structured with FI on each week as a "trait." The additive genetic and litter effects were modeled to be common across different FI records by reducing the rank of the covariance matrices using second- and first-order Legendre polynomials of age on test, respectively. The fixed effect and random residual variance were estimated for each weekly FI trait. Residual feed intake (RFI) was derived from the conditional distribution of FI given the breeding values of ADG100 and LMP. The heritability of FI varied by week on test in Duroc (0.12 to 0.19), Landrace (0.13 to 0.22), and Yorkshire (0.21 to 0.23). The heritability of RFI was lowest and highest in wk 6 (0.03) and 10 (0.10), respectively, in Duroc and wk 7 (0.04 and 0.02) and 1 (0.09 and 0.20), respectively, in Landrace and Yorkshire. The proportion of FI genetic variance explained by RFI ranged from 20 to 75% in Duroc, from 19 to 75% in Landrace, and from 11 to 91% in Yorkshire. Average daily gain from 30 to 100 kg BW and ADG30 heritabilities were moderate in Duroc (0.24 and 0.22, respectively), Landrace (0.34 and 0.25, respectively), and Yorkshire (0.34 and 0.22, respectively). Lean meat percentage heritability was moderate in Duroc (0.37) and large in Landrace (0.62) and Yorkshire (0.60). The genetic correlation of FI with ADG100 increased by week on test followed by a 32% decrease from wk 7 in Duroc and a 7% decrease in dam line breeds. Defining RFI as genetically independent of production traits leads to consistent and easy interpretable breeding values. The genetic parameters of traits in the feed efficiency complex and their dynamics over the test period showed breed differences that could be related to the fatness and growth potential of the breeds. The Horizontal model can be used to simultaneously analyze repeated and single recorded traits through proper modeling of the environmental variances and covariances.

Reliability of surface electromyography measurements from the suprahyoid muscle complex

Assessment of swallowing musculature using motor evoked potentials (MEPs) can be used to evaluate neural pathways. However, recording of the swallowing musculature is often invasive, uncomfortable and unrealistic in normal clinical practice. To investigate the possibility of using the suprahyoid muscle complex (SMC) using surface electromyography (sEMG) to assess changes to neural pathways by determining the reliability of measurements in healthy participants over days. Seventeen healthy participants were recruited. Measurements were performed twice with one week between sessions. Single-pulse (at 120% and 140% of the resting motor threshold (rMT)) and paired-pulse (2 ms and 15 ms paired pulse) transcranial magnetic stimulation (TMS) were used to elicit MEPs in the SMC which were recorded using sEMG. ≈50% of participants (range: 42-58%; depending on stimulus type/intensity) had significantly different MEP values between day 1 and day 2 for single-pulse and paired-pulse TMS. A large stimulus artefact resulted in MEP responses that could not be assessed in four participants. The assessment of the SMC using sEMG following TMS was poorly reliable for ≈50% of participants. Although using sEMG to assess swallowing musculature function is easier to perform clinically and more comfortable to patients than invasive measures, as the measurement of muscle activity using TMS is unreliable, the use of sEMG for this muscle group is not recommended and requires further research and development.

Global mRNA sequencing of human skeletal muscle: Search for novel exercise-regulated myokines

Objective

Skeletal muscle is an important secretory organ, producing and releasing numerous myokines, which may be involved in mediating beneficial health effects of physical activity. More than 100 myokines have been identified by different proteomics approaches, but these techniques may not detect all myokines. We used mRNA sequencing as an untargeted approach to study gene expression of secreted proteins in skeletal muscle upon acute as well as long-term exercise.

Methods

Twenty-six middle-aged, sedentary men underwent combined endurance and strength training for 12 weeks. Skeletal muscle biopsies from m. vastus lateralis and blood samples were taken before and after an acute bicycle test, performed at baseline as well as after 12 weeks of training intervention. We identified transcripts encoding secretory proteins that were changed more than 1.5-fold in muscle after exercise. Secretory proteins were defined based on either curated UniProt annotations or predictions made by multiple bioinformatics methods.

Results

This approach led to the identification of 161 candidate secretory transcripts that were up-regulated after acute exercise and 99 that where increased after 12 weeks exercise training. Furthermore, 92 secretory transcripts were decreased after acute and/or long-term physical activity. From these responsive transcripts, we selected 17 candidate myokines sensitive to short- and/or long-term exercise that have not been described as myokines before. The expression of these transcripts was confirmed in primary human skeletal muscle cells during in vitro differentiation and electrical pulse stimulation (EPS). One of the candidates we identified was macrophage colony-stimulating factor-1 (CSF1), which influences macrophage homeostasis. CSF1 mRNA increased in skeletal muscle after acute and long-term exercise, which was accompanied by a rise in circulating CSF1 protein. In cultured muscle cells, EPS promoted a significant increase in the expression and secretion of CSF1.

Conclusion

We identified 17 new, exercise-responsive transcripts encoding secretory proteins. We further identified CSF1 as a novel myokine, which is secreted from cultured muscle cells and up-regulated in muscle and plasma after acute exercise.

•

Numerous transcripts were identified that were regulated in human skeletal muscle after acute and/or long-term exercise.

•

These transcripts encode potential myokines, which may play key roles in local and systemic adaptations to exercise.

•

CSF1 was identified as a novel myokine. CSF1 was increased after acute exercise, and secreted from cultured human myotubes in response to EPS.

Weekly Formative Exams and Creative Grading Enhance Student Learning in an Introductory Biology Course

First-year students often become discouraged during introductory biology courses when repeated attempts to understand concepts nevertheless result in poor test scores. This challenge is exacerbated by traditional course structures that impose premature judgments on students' achievements. Repeated testing has been shown to benefit student ability to recognize and recall information, but an effective means to similarly facilitate skill with higher-order problems in introductory courses is needed. Here, we show that an innovative format that uses a creative grading scheme together with weekly formative midterm exams produced significant gains in student success with difficult items requiring analysis and interpretation. This format is designed to promote tenacity and avoid discouragement by providing multiple opportunities to attempt demanding problems on exams, detailed immediate feedback, and strong incentives to retain hope and improve. Analysis of individual performance trajectories with heat maps reveals the diversity of learning patterns and provides rational means for advising students.