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Background Over the last decade, a new paradigm for heart failure with preserved ejection (HFpEF) development has been proposed. High burden of comorbidities would lead to a systemic inflammatory state and enhanced platelet activation. High platelet reactivity could be associated with higher mean platelet volume (MPV) due increased circulating immature platelets. Moreover, neutrophil-to-lymphocyte (NLR) reflects systemic inflammation. Both parameters have been associated with morbidity and mortality in heart failure (HF). However, data in HFpEF are limited. Purpose We aim to investigate the use of MPV and NLR to predict clinical outcome in HFpEF patients. Methods We prospectively enrolled 228 patients with HFpEF (79±9 years, 66% female patients) and 38 controls of similar age and gender (78±5, 63% female patients). All subjects underwent a complete two-dimensional echocardiography. Mean platelet volume and NLR were measured at baseline. Patients were followed over time for a primary end point of all-cause mortality or first HF hospitalization. The prognosis impact of MPV and NLR were determined with Cox proportional hazard models. Results Mean MPV and median NLR were significantly higher in HFpEF patients compared to controls (MPV: 11.7±1.1 fL vs 10.0±1.1 fL, p=0.005; NLR: 3.3 [2.2; 5.0] vs 2.2 [1.9; 2.9], p75th percentile (n=56) had more frequently a history of ischemic cardiomyopathy (46%, p=0.04). HFpEF patients with NLR >75th percentile (n=57) were more frequently in New York Heart Association functional (NYHA) III or IV class (58%, p=0.02) and had higher levels of NT-proBNP (2152 [1336; 6397] pg/mL vs 1690 [705; 3304] pg/mL, p=0.02). Over a median follow-up of 26 months [11.5–56.7 months], 136 HFpEF patients (60%) reached the composite end point (87 deaths and 107 hospitalizations for HF). In univariate Cox regression analysis for the primary end point, MPV >75th percentile (HR: 1.45 [0.99; 2.13], p=0.05) and NLR >75th percentile (HR: 1.59 [1.11; 2.28], p=0.01) were predictors of the primary composite endpoint. In multivariate Cox regression analysis, mean platelet volume >75th percentile (χ2=8.11, P=0.004), continuous MPV (χ2=4.64, P=0.03) provided significant additional prognostic value over a baseline model created using independent predictors of the primary composite end point: body mass index (BMI), NYHA class III or IV, chronic obstructive pulmonary disease (COPD), loop diuretics, estimated glomerular filtration rate (eGFR) and NT-proBNP. By contrast, NLR did not provide any additional information (Figure 1 and 2). Conclusion MPV level and NLR were significantly higher in HFpEF patients compared with controls of similar age and gender. Elevated MPV offers an additional prognostic indication for clinicians and more interestingly it supports the hypothesis that of platelet activation could be involved in disease pathophysiology in HFpEF. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Fondation Saint-Luc

Background Until 2021, the strongest guidelines on surgical correction of severe aortic regurgitation (AR) focused on the left ventricular systolic function (LVEF) and the presence of symptoms. However, those situations lead to an outcome penalty, even after surgical correction. Left ventricle end-systolic diameter (LVESD) gained in strength in 2021 European guidelines. Moreover, more inclusive cut-off values are now recommended (class IIb) in patients at low surgical risk, reflecting the will to recommend surgery before developing heart failure and its consequences on post-operative outcome. Purpose We sought to evaluate the impact of guidelines triggers and their recent changes on postoperative survival of patients with severe AR from a large multicentric international registry. Method and results Postoperative overall survival of 1899 patients operated for severe and chronic AR (mean age 49±15 years, 85% male) in the international multicenter surgery registry for aortic valve surgery, AVIATOR, was evaluated over a median of 37 months. Twelve patients (0.6%) died postoperatively, and 68 within 10 years. By multivariable Cox analysis, presence of heart failure symptoms (HR 2.60; 95% CI [1.20–5.66]; p=0; 016), and either LVESD >50 mm or >25 mm/m2 (HR 1.64; 95% CI [1.05–2.55]; p=0.029) predicted survival independently over and above age (HR 2.25 per SD, 95% CI [1.67–3.03], p20 mm/m2 or LVEF between 50–55%, 10-year survival 97±3%). Moreover, the sub-group of patients having a dilated LVESD >50 mm or >25 mm/m2 but a preserved LVEF >50% had excellent survival (10-year survival 95±3%). Conclusions In severe AR, patients operated on when meeting any class I trigger have postoperative survival penalty. Asymptomatic patients operated on earlier have better survival. This supports early surgery in AR as encouraged by the recent ESC/EACTS guidelines. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Fondation Nationale de la Recherche Scientifique of the Belgian Government

Background: Spinal muscular atrophy (SMA) is a rare neurodegenerative disease characterized by progressive muscular weakness, which occurs in one in 6,000 to 10,000 live births. The burden of SMA on Canadian patients and caregivers is not known. Objective: To characterize the burden of SMA in Canada as reported by patients and caregivers, including disease and treatment impacts, indirect costs, and caregiver burden. Methods: Surveys were distributed by Cure SMA Canada and Muscular Dystrophy Canada to individuals with SMA and their caregivers. The online surveys were anonymous and completed between January 28 and February 21, 2020. Results: 965 patient and 962 caregiver responses met the eligibility criteria. Patients reported SMA subtypes as: type I (25.0%), type II (41.3%), type III (29.3%). Using the EQ-5D, patients were shown to have impaired quality of life with an average health utility index of 0.49 (SD: 0.26). The median expenditure was $4,500 CAD (IQR: $1,587 – $11,000) for assistive devices; $6,800 CAD (IQR: $3,900–$13,000) on health professional services; and $1,200 CAD (IQR: $600 –$3,100) on SMA-related travel and accommodation in the past 12 months. Caregivers reported needing respite care (45.7%), physiotherapy for an injury from a lift/transfer (45.7%), or other health impacts (63.3%). Caregivers reported changes to personal plans, sleep disturbances, and work adjustments, with a mean Caregiver Strain Index score of 7.5 [SD: 3.3]. Conclusion: SMA in Canada is associated with a significant burden for patients and their caregivers.

Muscle paralysis induced with botulinum toxin (Botox) injection increases vascular porosity and reduces osteocyte lacunar density in the tibial cortical bone of skeletally mature rats. These morphological changes potentially affect interstitial fluid flow in the lacunar–canalicular porosity, which is thought to play a role in osteocyte mechanotransduction. The aim of this study was to investigate the effects of disuse-induced morphological changes on interstitial fluid velocity around osteocytes in the bone cortex. Micro-CT images from a previous study that quantified the effects of Botox-induced muscle paralysis on bone microarchitecture in skeletally mature rats were used to create high-resolution, animal-specific finite element models that included the vascular pores and osteocyte lacunae within the tibial metaphysis of Botox-injected (BTX, n = 8) and saline-injected control (CTRL, n = 8) groups. To quantify fluid flow, lacunar and canalicular porosities were modeled as fluid-saturated poroelastic materials, and boundary conditions were applied to simulate physiological loading. This modeling approach allowed a detailed quantification of the fluid flow velocities around osteocytes in a relatively large volume of bone tissue. The analysis demonstrated that interstitial fluid velocity at the vascular pore surfaces was significantly lower in BTX compared to CTRL because of the decreased vascular canal separation. No significant differences in average fluid velocity were observed at the osteocyte lacunae and no correlation was found between the fluid velocity and the lacunar density, which was significantly lower in BTX. Instead, the lacunar fluid velocity was dependent on the osteocyte’s specific position in the bone cortex and its proximity to a vascular pore.

Introduction. Currently, the issue of reducing electrical energy consumption in the technologies of processing agricultural products, in particular, milk is topical. In large part, these costs are associated with the implementation of heat treatment processes. The reduction of electrical energy consumption can be achieved in several ways, one of which is the development and application of solar-powered installations. In this case, the consumption of traditional electrical energy is significantly reduced, but the manufactures have the task of coordinating the installation parameters and the real production conditions of enterprises. Materials and Methods. The study examined energy consumption in milk processing technologies, plate heat exchanger operation modes and heliocollector performance indicators. The heating temperature of the coolant and the product was determined with an instrument complex that allows registering the temperature values in 8 different control points and transmitting the received signals to the personal computer hard disk. The method for defining the parameters of the plant for preparing the coolant in the technologies of milk processing with the use of a complex energy-substituting unit is proposed. The new technique provides a reduction of electric energy consumption from 30 to 70%. Results. The consumption of electrical energy for thermal processes can be reduced by using solar energy. To solve the problem of optimizing the ratio of product consumption, heating area in the heat exchanger, the area of the solar collectors of the energy-substituting installation, it is recommended to use the obtained graphical dependencies and the formula for determining the area of the solar collectors. Discussion and Conclusion. It is possible to determinate the area of solar collectors of complex energy-substituting installation for real production conditions through using the obtained analytical dependence taking into account the dependence the specified parameter on a temperature mode of heating, the area of a surface of heating in the heat exchanger, and weight of milk being processed per unit of time. The obtained graphical dependencies make it possible to determine the product consumption and heating area for the given heating temperature values.

Psychische Uberbelastungen im Arztberuf fuhren zu emotionaler Erschopfung, dem Gefuhl von Uberforderung sowie reduzierter Leistungszufriedenheit und Interessensverlust, auch als „Burn-out“ –bezeichnet, mit weitreichenden Folgen fur das Personal im Gesundheitswesen, die Patientenversorgung und das Gesundheitssystem insgesamt. Wie kann die Stressbewaltigung klinisch tatiger Anasthesisten verbessert werden? Dazu wurden vom Programm der Mindfulness-Based Stress Reduction (MBSR) abgeleitete Intervention sowie kurze Ubungen in den anasthesiologischen Alltag integriert. Die Intervention nahm Elemente aus dem klassischen MBSR auf, indem alltagstaugliche Kurzubungen erlernt wurden. Direkt vor (t0) und nach (t1) der Intervention sowie nach 3 (t2) und 6 Monaten (t3) wurden im Arbeitsalltag subjektive und objektive Stressparameter erhoben. Die subjektiven Stressparameter wurden mittels validierter Fragebogen (WHO‑5, RS-11, MBI-22, PSS-10) erhoben, die objektiven durch die Messung der Herzfrequenzvariabilitat (HRV) und der Haarkortisolkonzentration (HCC). Daten von 27 Personen wurden erhoben und ausgewertet. Es zeigten sich zwischen t3 und t0 ein signifikanter Anstieg der psychischen Widerstandsfahigkeit (RS-11) mit hoher Effektstarke (p = 0,013; r = 0,59) sowie eine signifikante Reduktion von Burn-out-Symptomen (MBI-22) ebenfalls mit hoher Effektstarke (p = 0,019; r = 0,57). Ein fur Arztinnen und Arzte einer universitaren Anasthesieabteilung angepasstes und an MBSR angelehntes Programm mit regelmasigen Kurzubungen ist in den Arbeitsalltag implementierbar. Es zeigen sich klare Hinweise darauf, dass es die psychische Widerstandsfahigkeit erhoht und Burn-out-Symptome senkt.

(1) Background: The technological advances achieved with minimally-invasive surgery have enabled procedures to be undertaken in outpatient settings, and there has been growing acceptance of performing minimally-invasive transforaminal interbody fusion (TLIF) in the ambulatory surgery center (ASC). The purposeof this study was to determine the comparative 30 day safety profile for patients treated with TLIF in the ASC versus the hospital setting. (2) Methods: This multi-center study retrospectively collected baseline characteristics, perioperative variables, and 30 day postoperative safety outcomes for patients having a TLIF using the VariLift®-LX expandable lumbar interbody fusion device. Outcomes were compared between patients undergoing TLIF in the ASC (n = 53) versus in the hospital (n = 114). (3) Results: Patients treated in-hospital were significantly older, frailer and more likely to have had previous spinal surgery than ASC patients. Preoperative back and leg pain scores were similar between study groups (median, 7). ASC patients had almost exclusively one-level procedures (98%) vs. 20% of hospital procedures involving two-levels (p = 0.004). Most procedures (>90%) employed a stand-alone device. The median length of stay for hospital patients was five times greater than for ASC patients (1.4 days vs. 0.3 days, p = 0.001). Emergency department visits, re-admissions and reoperations were rare whether the patients were managed in the traditional hospital setting or the ASC. (4) Conclusions: There were equivalent 30 day postoperative safety profiles for patients undergoing a minimally-invasive TLIF irrespective of surgical setting. For appropriately selected surgical candidates, the ASC offers a viable and attractive option for their TLIF procedure with the advantage of same-day discharge and at-home recovery.

Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): The Funds Pierre Masure, Alphonse and Marie Walckiers & De Winter-Vermant, by King Baudouin Foundation Background Radiation therapy (RXT) is a keystone in breast cancer (BC) treatment which allows to reduce risk of local recurrence and cancer related mortality. Yet these benefits may be offset by increases in cardiovascular mortality due to late radiation induced cardiotoxicity. Indeed, prior works in patients exposed to high cardiac radiation dose demonstrated development of diffuse and focal myocardial fibrosis by cMR. However, whether such effects may also occur after contemporary BC-RXT with lower cardiac dose exposure, has not yet been evaluated. Purpose To evaluate the long-term cardiac safety of contemporary RXT for BC, we sought to estimate the prevalence of cardiac functional and structural focal and myocardial abnormalities in BC survivors treated by RXT 10 years earlier, in direct relation to measured local radiation dose exposure. Methods In a prospective cross-sectional study, we studied 27 women (mean age 62 ± 7 years) treated with adjuvant RXT but without chemotherapy for a first left (n= 12) or right sided (n= 15) BC between 2009 and 2011, which had no history of coronary artery or cardiac disease and compared them to 20 age matched (64 ± 10 years) healthy female controls (without history of BC or RXT). All subjects underwent 3T cMR to measure LV volumes, function, global longitudinal (GLS), circumferential (GRS) and radial strains (GRS) as well as extracellular volume (ECV) and late gadolinium enhancement (LGE). Functional and structural abnormalities in women with BC were compared to healthy controls. We also compared abnormalities among patients with left vs right BC and related them to mean heart radiation dose measured at the time of RXT (Figure). Results Mean cardiac radiation exposure in BC survivors was 1.87 ± 1.7 Gy (range 0-7.9 Gy). Exposure was significantly (p Conclusions In this preliminary work, patients with BC treated by adjuvant RXT 10 years ago, presented no significant structural or functional abnormalities in relation to cardiac dose exposure nor in comparison to healthy controls. This suggests that current RXT protocols for BC are safe without long-term functional or morphological cardiac side effects.

Reduced mechanical loading can lead to disuse osteoporosis, resulting in bone fragility. Disuse models report macroscopic bone loss due to muscle inactivity and immobilization, yet only recently has there been quantification of the effects of disuse on the vascular pores and osteocyte network, which are believed to play an important role in mechanotransduction via interstitial fluid flow. The goal of this study was to perform a high-resolution analysis of the effects of muscle inactivity on intracortical porosity and osteocyte lacunar density in skeletally mature rats. Muscle paralysis was induced in 20-week-old female Sprague Dawley rats by injection of botulinum neurotoxin. Rats were injected in the right hindlimb muscles with either Botox (BTX, n = 8) or saline solution (CTRL, n = 8), with a third group used as baseline controls (n = 8). Four weeks after injection, Botox caused a ∼60% reduction in hindlimb muscle mass. High-resolution micro-CT analysis showed that Botox-induced muscle paralysis increased vascular canal porosity and reduced osteocyte lacunar density within the tibial metaphysis cortex. Cortical thickness and other areal properties were diminished in the proximal tibial metaphysis, whereas no differences were found in the mid-diaphysis. Within the BTX group, the injected limbs showed a lower cancellous bone volume fraction relative to the contralateral limb. These results indicate that diminished muscle activity alters the vascular canal porosity and osteocyte lacunar density in cortical bone, which could alter interstitial fluid flow, affecting molecular transport and the transmission of mechanical signals to osteocytes. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

OBJECTIVES: The optimal management of functional tricuspid regurgitation (FTR) in the setting of mitral valve operations remains controversial. The current practice is both centre specific and surgeon specific with guidelines based on non-randomized data. A prospective randomized trial was performed to evaluate the worth of less-than-severe FTR repair during mitral valve procedures. METHODS: A single-centre randomized study was designed to allocate patients with less-than-severe FTR undergoing mitral valve surgery to be prophylactically treated with or without tricuspid valve annuloplasty (TVP- or TVP+). These patients were analysed using longitudinal cardiopulmonary exercise capacity, echocardiographic follow-up and cardiac magnetic resonance. The primary outcome was freedom from more than or equal to moderate tricuspid regurgitation with vena contracta ≥4 mm. Secondary outcomes were maximal oxygen uptake and right ventricular (RV) dimension and function. RESULTS: A total of 53 patients were allocated to receive concomitant TVP+, and 53 patients were treated conservatively (TVP-). At 5 years, tricuspid regurgitation was observed to be greater than mild in 10 patients in the TVP- group and no patients in the TVP+ group (P < 0.01). Maximal oxygen uptake, RV basal diameter, end-diastolic diameter and end-systolic diameter and fractional area changes were similar in both groups. Cardiac magnetic resonance confirmed no differences in RV end-diastolic volume, RV end-systolic volume and RV ejection fraction. CONCLUSIONS: This single-centre prospective randomized trial demonstrated that prophylactic tricuspid annuloplasty irrespective of annular dilatation at the time of mitral surgery reduced the recurrence of moderate or severe FTR at 5-year follow-up and reduced the pulmonary pressure. Nevertheless, the functional capacity, the RV function and the RV dimension remained similar.

This is the story of a career in theoretical chemistry during a time of dramatic changes in the field due to phenomenal growth in the availability of computational power. It is likewise the story of the highly gifted graduate students and postdoctoral fellows that I was fortunate to mentor throughout my career. It includes reminiscences of the great mentors that I had and of the exciting collaborations with both experimentalists and theorists on which I built much of my research. This is an account of the developments of exciting scientific disciplines in which I was involved: vibrational spectroscopy, molecular reaction mechanisms and dynamics, e.g., in atmospheric chemistry, and the prediction of new, exotic molecules, in particular noble gas molecules. From my very first project to my current work, my career in science has brought me the excitement and fascination of research. What a wonderful pursuit!

Muscle paralysis induced with botulinum toxin (Botox) injection increases vascular porosity and reduces osteocyte lacunar density in the tibial cortical bone of skeletally mature rats. These morphological changes potentially affect interstitial fluid flow in the lacunar-canalicular porosity, which is thought to play a role in osteocyte mechanotransduction. The aim of this study was to investigate the effects of disuse-induced morphological changes on interstitial fluid velocity around osteocytes in the bone cortex. Micro-CT images from a previous study that quantified the effects of Botox-induced muscle paralysis on bone microarchitecture in skeletally mature rats were used to create high-resolution, animal-specific finite element models that included the vascular pores and osteocyte lacunae within the tibial metaphysis of Botox-injected (BTX, n = 8) and saline-injected control (CTRL, n = 8) groups. To quantify fluid flow, lacunar and canalicular porosities were modeled as fluid-saturated poroelastic materials, and boundary conditions were applied to simulate physiological loading. This modeling approach allowed a detailed quantification of the fluid flow velocities around osteocytes in a relatively large volume of bone tissue. The analysis demonstrated that interstitial fluid velocity at the vascular pore surfaces was significantly lower in BTX compared to CTRL because of the decreased vascular canal separation. No significant differences in average fluid velocity were observed at the osteocyte lacunae and no correlation was found between the fluid velocity and the lacunar density, which was significantly lower in BTX. Instead, the lacunar fluid velocity was dependent on the osteocyte's specific position in the bone cortex and its proximity to a vascular pore.

Funding Acknowledgements Fond national de la recherche scientifique (FNRS) Background New research methods to assess cardiac function such as 2D speckle tracking echocardiography (STE) are emerging in clinical practice after showing incremental prognostic information beyond ejection fraction in a variety of settings. However, comprehensive data regarding the day to day reproducibility is still lacking. Aim To assess the inter and especially the day to day intravariability of RV and LV GLS STE in direct comparison with cMR in asymptomatic volunteers and in patients with heart failure. Methods for the volunteers:30 asymptomatic volunteers ( 34 ± 9years, 33% were women) underwent 2 cMR and 2 echocardiography studies with a maximal interval between each study of 6 days and 20 minutes between each technique. RV strain was performed on a RV focus view and LV strain on 4, 3 and 2 chamber views using the segment software. cMR- RVEF and cMR-LVEF was performed in short axis view. Preliminary Results: Volunteers Average values for the the STE measurements was -24.2%±2.3 and -27.4%±2.1 for LV and RV GLS respectively. Average values for the 2 cMR measurements was 61.9% ±4.5 and 56.3%± 6.2% for cMR-LVEF and RVEF respectively. The interstudy varability coefficient of variability was lower in GLS-STE parameters (RV-GLS = 7.7% and LV-GLS = 6.3%) than for the cMR parameters (cMR-LVEF= 8.2% and cMR-RVEF= 12.9%). The superior interstudy reproducibility resulted in lower calculated sample sizes require by GLS compared with cMR to show clinically relevant changes in LV and RV function. (Figure 1) Conclusion LV and RV -GLS- STE has excellent interstudy reproducibility in normal hearts and is as good as cMR- LVEF and RVEF. Echocardiography cMR LV-GLS-STE RV-GLS-STE LVEF RVEF Mean difference ±SD 0.6 ± 1.88 0.5± 1.73 1.14 ± 5.22 0.98 ± 7.23 Coefficient of variation 7.7% 6.3% 8.2% 12.9% Sample Size for 2% absolute change in GLS or 5% absolute change in cMR- EF 18 16 22 44 Sample size required to detect a clinically significant change in global longidutdinal strain speckle tracking (GLS-STE) echocardiographie and cMR - ejection fraction (EF). RV and LV indicate Right ventricular and left ventricular respectively.

Funding Acknowledgements Fondation de Recherche Scientifique Belge FRSM PDR 19488731 BACKGROUND 2D-speckle-tracking (ST) echocardiography is currently widely used for estimation of global (G) and regional myocardial deformation. In previous works, we showed good correlation between global longitudinal (LS) and circumferential strain (CS) from one 2DST vendor with cMR-Tagging, however with significant bias between both methods. Also, we found poorer agreement between 2DST and cMR-Tagging on regional basis. However it is unknown how 2DST from other vendors would comparte to cMR tagging. PURPOSE To asssess vendor differences in global and regional strain assessment and compare 1) the agreement of 2 different 2DST softwares for global and regional LS and CS among each other and against cMR-Tagging as reference; and 2) the accuracy of both softwares to detect infarcted segments. METHODS 100 subjects with different cardiac disease (among which 31 with chronic infarct) underwent 2DST and tagging and LGE cMR on the same day. Global and regional CS (16 AHA segments) and LS (18 AHA segments) was computed using 2 different ST vendor softwares and compared to cMR-Tagging with HARP. Accuracy of regional 2D-ST by both vendors to detect infarcted segments (ie >75% transmurality of late gadolinium) was compared using ROC analysis. RESULTS Global LS (ICC = 0.87) and CS 2DST (ICC = 0.83, p Agreement for regional strains is shown in the figure below. Overall, regional LS and CS agreed adequately among both vendors. Agreement of regional LS and CS vs cMR-tagging was slightly better for vendor 1, with less bias than for vendor 2, and disagreement was similarly located (ie agreement with cMR-Tagging for LS in inferolateral inferior and inferoseptal basal segments). The predictive accuracy of regional CS and LS for detecting segments with infarct was higher for vendor 2 (AUC 0.76 and 0.68) than for vendor 1 (AUC 0.70 and 0.63) . CONCLUSION GLS agreed well among both vendors and with cMR-Tagging, confirming the universal validity of this measurement. However vendor 2 provided significantly greater GCS values and had higher bias against cMR-Tagging than vendor 1. On regional basis CS and LS agreed moderately well among both vendors, however vendor 2 agreed less with cMR-Tagging than vendor 1, but astoundingly had higher diagnostic accuracy for detecting infarct. Overall this findings call for further efforts in standardization of 2DST CS and regional strain. Abstract P1393 Figure.

Funding Acknowledgements Philips BACKGROUND Accurate and reproducible echocardiographic measurements are paramount for objective assessment and follow-up of the cardiac function. However, manual contouring – e.g., for determining left ventricular (LV) volumes and ejection fraction (EF) – is limited by image quality and operator experience. Meanwhile, despite the wider availability of (semi-)automated tools, strong multimodal validation is still lacking for their widespread and safe use in the clinical routine. PURPOSE To evaluate the accuracy and reproducibility of an Artificial Intelligence (AI)-based semi-automated tool to compute LV volumes and EF, in comparison with manual contouring, using cardiac magnetic resonance (cMR) as reference. METHODS Manual and AI measurements from echocardiography were compared to measurements from cMR in a retrospective two-centre study. One hundred fourteen patients in sinus rhythm were included; among those, 85 had abnormal LV function (56 dilated and 29 hypertrophic). Three successive cardiac cycles were available for apical 4- and 2-chamber views. Two senior (A1 and B1) and one junior (A2) cardiologists contoured the ED and ES endocardial borders in the cardiac cycle of their choice, while blinded to quantitative outcomes. For AI analysis, a deep convolutional neural networks model was used to segment the LV cavity on the frames selected by the three observers. This model was trained using ED and ES manual contouring from senior cardiologist A1 on an independent single-centre dataset that consisted of 700 apical 4- and 2-chamber views. The same biplane Simpson’s method was used to compute all LV volumes and EF. RESULTS Despite challenging image quality (poor: 6%; fair: 33%; high: 61%, as rated by observers), the majority of the AI segmentations were deemed acceptable (75% in total; 80% for images of high quality). Overall, inter-observer agreement was better by AI than by manual contouring (ICC = 0.99 vs. 0.89, 1.00 vs. 0.95 and 0.95 vs. 0.89 for LVED, LVES and LVEF respectively, all p CONCLUSION The AI model generalized well to different sites, observers and image quality. Compared to manual contouring, LV volumes and EF by AI showed comparable or improved accuracy and higher reproducibility. These findings demonstrate the value of AI-based tools, with potential for full automation, for objective assessment and follow-up of the cardiac function. Abstract 154 Figure.

Chronic stress and high workload in physicians can lead to loss of interest, emotional exhaustion and finally in burnout syndrome. This can cause serious consequences not only for the physicians personally and their own health by developing extensive health impairments, e.g. depression, suicide, substance abuse and poor self-care but also for patient care, reflected in an increase of medical errors, longer recovery times, lower care quality and consequently lower patient satisfaction. Additionally, it can also have negative effects on the healthcare system by reduced productivity, increased physician turnover and thereby higher costs.This pilot study investigated brief interventions inspired by mindfulness-based stress reduction (MBSR) combined with short daily meditation exercises in the everyday work of anesthetists at a university hospital. Secondly, whether this program increases the development of coping mechanisms for stress and improves participants' resilience and health status.The pilot study was designed as a monocenter prospective interventional study with four different points of measurement. Subjective and objective stress parameters were measured directly before (t0) and after (t1) the intervention as well as 3 (t2) and 6 (t3) months after end of the intervention. Measurements took place during work time and at the workplace. The intervention was based on the classical MBSR including short daily exercises and lasted for 6 weeks with sessions lasting 1- 1.5 h and an additional 20 min of daily mediation exercises. The subjective parameters were based on validated questionnaires, such as the World Health Organization (WHO) well-being index (WHO-5), resilience scale (RS-11), Maslach burnout inventory (MBI-22) and perceived stress scale (PSS-10). For objective parameters heart rate variability (HRV) was evaluated during rest and after exposure to physical exercise and hair cortisol concentrations (HCC) in a 1.5 cm length of a hair, which represents the equivalent of a 6-week period.Data from 27 subjects could be analyzed. Between t3 and t0 a significant improvement of resilience was detected as a positive personality trait measured by RS-11 with a large effect size (p = 0.013; r = 0.59) as well as a significant reduction of burnout symptoms (MBI-22) also with a large effect size (p = 0.019; r = 0.57). Furthermore, a significant decrease was found in well-being (WHO-5) between t2 and t0 (p = 0.003, r = 0.67) and between t1 and t0 (p = 0.001, r = 0.71). The objective parameters did not show any significant differences between the examinations.An MBSR-based intervention in combination with short exercises during and after work can be implemented in daily work of anesthetists at a university hospital. Furthermore, there was clear evidence that the intervention program increased resilience and reduced burnout symptoms for up to 6 months. These findings are in line with the literature that MBSR reduces risk of burnout symptoms. The decrease in well-being might be biased by a high amount of socially accepted answers at the beginning of the study (t0).