Reconstruction of occluded pelvis markers during marker-based motion capture with industrial exoskeletons

Industrial back support exoskeletons are a promising solution to alleviate lumbar musculoskeletal strain. Due to the complexity of spinal loading, evaluation of EMG data alone has been considered insufficient to assess their support effects, and complementary kinematic and dynamic data are required. However, the acquisition of marker-based kinematics is challenging with exoskeletons, as anatomical reference points, particularly on the pelvis, are occluded by exoskeleton structures. The aim of this study was therefore to develop and validate a method to reliably reconstruct the occluded pelvic markers. The movement data of six subjects, for whom pelvic markers could be placed while wearing an exoskeleton, were used to test the reconstructions and compare them to anatomical landmarks during lifting, holding and walking. Two separate approaches were used for the reconstruction. One used a reference coordinate system based on only exoskeleton markers (EXO), as has been suggested in the literature, while our proposed method adds a technical marker in the lumbar region (LUMB) to compensate for any shifting between exoskeleton and pelvis. Reconstruction with EXO yielded on average an absolute linear deviation of 54 mm ± 16 mm (mean ± 1SD) compared to anatomical markers. The additional marker in LUMB reduced mean deviations to 14 mm ± 7 mm (mean ± 1SD). Both methods were compared to reference values from the literature for expected variances due to marker placement and soft tissue artifacts. For LUMB 99% of reconstructions were within the defined threshold of 24 mm ±9 mm while for EXO 91% were outside.

Atrial Arrhythmias in Patients with Pulmonary Hypertension

TOPIC IMPORTANCE

Atrial arrhythmia (AA) are common in patients with pulmonary hypertension (PH) and contribute to morbidity and mortality. Given the growing PH population, it is important to understand the pathophysiology, clinical impact, and management of AA in PH.

REVIEW FINDINGS

AA occurs in PH with a five-year incidence of 10-25%. AA confers a higher morbidity and mortality, and restoration of normal sinus rhythm improves survival and functionality. AA is thought to develop due to structural alterations of the right atrium caused by changes to the right ventricle (RV) due to elevated pulmonary artery pressures. AA can subsequently worsen RV function. Current guidelines do not provide comprehensive recommendations for the management of AA in PH. There is a lack of robust evidence to favor a specific treatment approach. While the role of medical rate or rhythm control, and the use of cardioversion and ablation, can be inferred from other populations, there is a lack of evidence in the PH population. Much remains to be determined regarding the optimal management strategy. We present here our institutional approach and discuss areas for future research.

SUMMARY

This review highlights the epidemiology and pathophysiology of AA in patients with PH, describes the relationship between AA and RV dysfunction, and discusses current management practices. We outline our institutional approach and offer directions for future investigation.

Percutaneous Retrieval of an Embolized Transcatheter Mitral Valve Repair Clip Causing ST-Segment Elevation Myocardial Infarction

Mitral valve repair clip detachment and embolization is a rare phenomenon, with few reported cases. We describe a case of subacute transcatheter mitral valve repair clip embolization presenting as an inferior ST-segment elevation myocardial infarction, with subsequent successful percutaneous device retrieval. (Level of Difficulty: Intermediate.).

Effect of robotic tilt table verticalization on recovery in patients with disorders of consciousness: a randomized controlled trial

Verticalization is a common therapeutic intervention during rehabilitation of patients with disorders of consciousness (DoC). The Erigo®Pro is a robotic tilt-table (RTT) with built-in stepping unit for the lower extremities to prevent orthostatic hypotension during verticalization. In addition, the system also provides functional electrical stimulation (FES) of muscles of the lower extremities. In this randomized controlled clinical trial (RCT), 47 patients with subacute DoC received a 4-week verticalization regime (16 verticalization sessions) and were allocated to one of three experimental groups: (1) verticalization by means of RTT with FES, (2) by means of RTT without FES, or (3) by conventional physiotherapy (CPT). Level of consciousness (LoC), spasticity, functional independence in daily activities, and functional brain connectivity measured by means of high-density quantitative EEG were assessed at baseline, directly after the verticalization program and after 6 months. There was a similar clinical improvement in all three experimental groups. RTT was not associated with an effect on any of the clinical outcomes. Verticalization or mobilization time during the study period was significantly positively correlated with recovery of consciousness (rho = 0.494, p < 0.001) in the short term and showed a statistical trend at the 6 months follow-up (rho = 0.244, p = 0.078). In conclusion, RTT treatment is not more effective in promoting recovery of consciousness than CPT in subacute DoC patients. Yet, our data suggest, that verticalization may be an important and feasible rehabilitation intervention in this group of patients. ClinicalTrials.gov NCT Number NCT02639481, registered on December 24, 2015.

PerBrain: a multimodal approach to personalized tracking of evolving state-of-consciousness in brain-injured patients: protocol of an international, multicentric, observational study

BACKGROUND

Disorders of consciousness (DoC) are severe neurological conditions in which consciousness is impaired to various degrees. They are caused by injury or malfunction of neural systems regulating arousal and awareness. Over the last decades, major efforts in improving and individualizing diagnostic and prognostic accuracy for patients affected by DoC have been made, mainly focusing on introducing multimodal assessments to complement behavioral examination. The present EU-funded multicentric research project "PerBrain" is aimed at developing an individualized diagnostic hierarchical pathway guided by both behavior and multimodal neurodiagnostics for DoC patients.

METHODS

In this project, each enrolled patient undergoes repetitive behavioral, clinical, and neurodiagnostic assessments according to a patient-tailored multi-layer workflow. Multimodal diagnostic acquisitions using state-of-the-art techniques at different stages of the patients' clinical evolution are performed. The techniques applied comprise well-established behavioral scales, innovative neurophysiological techniques (such as quantitative electroencephalography and transcranial magnetic stimulation combined with electroencephalography), structural and resting-state functional magnetic resonance imaging, and measurements of physiological activity (i.e. nasal airflow respiration). In addition, the well-being and treatment decision attitudes of patients' informal caregivers (primarily family members) are investigated. Patient and caregiver assessments are performed at multiple time points within one year after acquired brain injury, starting at the acute disease phase.

DISCUSSION

Accurate classification and outcome prediction of DoC are of crucial importance for affected patients as well as their caregivers, as individual rehabilitation strategies and treatment decisions are critically dependent on the latter. The PerBrain project aims at optimizing individual DoC diagnosis and accuracy of outcome prediction by integrating data from the suggested multimodal examination methods into a personalized hierarchical diagnosis and prognosis procedure. Using the parallel tracking of both patients' neurological status and their caregivers' mental situation, well-being, and treatment decision attitudes from the acute to the chronic phase of the disease and across different countries, this project aims at significantly contributing to the current clinical routine of DoC patients and their family members.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04798456 . Registered 15 March 2021 - Retrospectively registered.

AB0444 ENPATORAN: PRECLINICAL EVIDENCE SUPPORTING GLUCOCORTICOID DOSE REDUCTION AND PHASE II STUDY DESIGN IN PATIENTS WITH SLE AND/OR CLE (WILLOW)

Background

Enpatoran is a potent selective dual inhibitor of toll-like receptor (TLR) 7 and TLR8, aberrant activation of which may be involved in systemic lupus erythematosus (SLE) pathogenesis and glucocorticoid resistance.1,2,3 Enpatoran suppressed disease development in lupus mouse models, improving survival and reducing proteinuria, autoantibodies, and the interferon (IFN) gene signature.1 In healthy participants and patients hospitalized with COVID-19 pneumonia, enpatoran was well tolerated and demonstrated effective TLR7/8 engagement.4 Enpatoran is potentially glucocorticoid sparing and may help avoid the detrimental effects of long-term corticosteroid use in SLE management.5,6

Objectives

To evaluate the glucocorticoid-sparing effect of enpatoran and design a basket trial to assess its efficacy and safety in patients with SLE and/or cutaneous lupus erythematosus (CLE).

Methods

Cytokine concentrations and gene expression changes were measured in stimulated human peripheral blood mononuclear cells (PBMCs) from healthy donors after treatment with dexamethasone, TLR7/8 inhibitor, or both. A Phase II, basket design proof-of-concept, dose-finding study in patients with SLE and/or CLE (WILLOW) was designed.

Results

In healthy donor PBMCs, synergy was observed between TLR7/8 inhibitor and dexamethasone. Combination treatment inhibited cytokine release (IL-6) with greater potency than either treatment alone and reduced the expression of nuclear factor-kappa B and IFN-regulated genes. WILLOW is a Phase II, basket proof-of-concept, dose-finding, randomized, double-blind, placebo (PBO)-controlled 24-week study with two cohorts (NCT05162586, Figure 1). The primary objectives of WILLOW are to evaluate the dose–response relationship of enpatoran in reducing disease activity based on Cutaneous Lupus Erythematosus Disease Area and Severity Index-A (CLASI-A) or BILAG-Based Composite Lupus Assessment (BICLA) response rate. The secondary objectives are to investigate effects on both BICLA response and clinically meaningful corticosteroid reduction and evaluate disease control (including clinically meaningful corticosteroid reduction) in patients with predominantly active CLE or SLE. Cohort A will enroll patients with CLE (active subacute CLE and/or discoid LE) or SLE with predominantly active lupus rash. Cohort B, in two parts, will enroll SLE patients with moderate to severe systemic disease activity. Part 1 will assess clinical signal and Part 2 may be adapted to improve dose finding. Glucocorticoid-sparing will be evaluated by mandatory tapering to a prednisone-equivalent dose of ≤5 mg/day.

Figure 1.

WILLOW study design.

Cohort A and Cohort B Part 1 will start in parallel.

*Part 2 will be initiated after a pre-specified number of patients are enrolled in Part 1; enpatoran doses in Part 2 may be adapted to improve dose finding (dashed boxes).

BILAG, British Isles Lupus Assessment Group; CLASI-A, Cutaneous Lupus Erythematosus Disease Area and Severity Index-A; CLE, cutaneous lupus erythematosus; CS, corticosteroid; DBPC, double-blind placebo-controlled; DLE, discoid lupus erythematosus; PBO, placebo; SCLE, Subacute cutaneous lupus erythematosus; SLE, systemic lupus erythematosus; SLEDAI, Systemic Lupus Erythematosus Disease Activity Index.

Conclusion

Enpatoran is a novel TLR7/8 inhibitor and may enable glucocorticoid dose reduction in patients with SLE and CLE. The WILLOW study incorporates multiple novel elements including a basket design and evaluation of glucocorticoid-sparing.

References

[1]Vlach, et al. J Pharmacol Exp Ther. 2021;376:397–409;

[2]Northcott, et al. Lancet Rheumatol. 2021;5:e357–e370;

[3]Guiducci, et al. Nature. 2010;465:937–941;

[4]Port, et al. Pharmacol Res Perspect. 2021;9:e00842;

[5]Thamer, et al. J Rheumatol. 2009;36:560–564;

[6]Ruiz-Irastorza, et al. Rheumatology. 2012;51:1145–1153.

Acknowledgements

This study was sponsored by the healthcare business of Merck KGaA, Darmstadt, Germany (CrossRef Funder ID: 10.13039/100009945), who funded medical writing support by Bioscript Stirling Ltd.

Disclosure of Interests

Eric F. Morand: None declared, Andrew Bender Shareholder of: Shares in Merck KGaA, Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), Aditee Deshpande Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), Bharat Vaidyanathan Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), cristina vazquez mateo Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), Melinda Przetak Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), Flavie Moreau Employee of: EMD Serono Research & Development institute (an affiliate of Merck KGaA), Mukhy Khursheed Employee of: Merck Serono Ltd (an affiliate of Merck KGaA), Sanjeev Roy Employee of: Ares Trading SA (an affiliate of Merck KGaA), David Pearson Consultant of: Biogen Inc.

Dataset for multidimensional assessment to incentivise decentralised energy investments in Sub-Saharan Africa

In this data article, we present datasets from the construction of a composite indicator, the Photovoltaic Decentralised Energy Investment (PV-DEI) index, presented in detail in [1]. This article consists of a comprehensive energy-related data collected in practice from several sources, and from the outputs of the methodology described in [1]. The PV-DEI was designed and developed to measure the multidimensional factors that currently direct decentralised renewable energy investments. The PV-DEI index includes 52 indicators and was constructed because factors stimulating investment cannot be captured by a single indicator, e.g. competitiveness, affordability, or governance [1]. The PV-DEI index was built in alignment with a theoretical framework guided by an extensive review of the literature surrounding investment in decentralised Photovoltaic (PV), which led to the selection of its indicators. The structure of the PV-DEI was evaluated for its soundness using correlational assessments and principal component analyses (PCA). The raw data provided in this article can enable stakeholders to focus on specific country indicators, and how scores on these indicators contributed to a countries overall rank within the PV-DEI index. The data can be used to weight indicators depending on the specifications of several different stakeholders (such as NGOs, private sector or international institutions).

Adverse device-device interaction between pacemaker and subcutaneous implantable cardiac defibrillator

A 26-year-old patient with prior surgery for Ebstein's anomaly and a pacemaker (placed for post-surgical heart block and poor underlying rhythm) underwent SICD was placement. During defibrillation testing, device-device interaction led to undersensing of ventricular fibrillation with failure to shock. Increasing the pacemaker sensitivity resolved the problem but post shock pacing was unable to capture the heart after both shocks. The patient underwent removal of both the pacemaker and the SICD and placement of a transvenous ICD. Complex device-device interactions can occur in patients who are pacemaker dependent and undergo placement of a SICD.

Competing risks in patients with primary prevention implantable cardioverter-defibrillators: Global Electrical Heterogeneity and Clinical Outcomes study

BACKGROUND

Global electrical heterogeneity (GEH) is associated with sudden cardiac death in the general population. Its utility in patients with systolic heart failure who are candidates for primary prevention (PP) implantable cardioverter-defibrillators (ICDs) is unclear.

OBJECTIVE

The purpose of this study was to investigate whether GEH is associated with sustained ventricular tachycardia/ventricular fibrillation leading to appropriate ICD therapies in patients with heart failure and PP ICDs.

METHODS

We conducted a multicenter retrospective cohort study. GEH was measured by spatial ventricular gradient (SVG) direction (azimuth and elevation) and magnitude, QRS-T angle, and sum absolute QRST integral on preimplant 12-lead electrocardiograms. Survival analysis using cause-specific hazard functions compared the strength of associations with 2 competing outcomes: sustained ventricular tachycardia/ventricular fibrillation leading to appropriate ICD therapies and all-cause death without appropriate ICD therapies.

RESULTS

We analyzed 2668 patients (mean age 63 ± 12 years; 624 (23%) female; 78% white; 43% nonischemic cardiomyopathy; left ventricular ejection fraction 28% ± 11% from 6 academic medical centers). After adjustment for demographic, clinical, device, and traditional electrocardiographic characteristics, SVG elevation (hazard ratio [HR] per 1SD 1.14; 95% confidence interval [CI] 1.04-1.25; P = .004), SVG azimuth (HR per 1SD 1.12; 95% CI 1.01-1.24; P = .039), SVG magnitude (HR per 1SD 0.75; 95% CI 0.66-0.85; P < .0001), and QRS-T angle (HR per 1SD 1.21; 95% CI 1.08-1.36; P = .001) were associated with appropriate ICD therapies. Sum absolute QRST integral had different associations in infarct-related cardiomyopathy (HR 1.29; 95% CI 1.04-1.60) and nonischemic cardiomyopathy (HR 0.78; 95% CI 0.62-0.96) (P_interaction = .022).

CONCLUSION

In patients with PP ICDs, GEH is independently associated with appropriate ICD therapies. The SVG vector points in distinctly different directions in patients with 2 competing outcomes.

Does Sex Modify an Association of Electrophysiological Substrate with Sudden Cardiac Death? The Atherosclerosis Risk in Communities (ARIC) Study

Background

Sex is a well-recognized risk factor for sudden cardiac death (SCD). We hypothesized that sex modifies the association of electrophysiological (EP) substrate with SCD.

Objective

The purpose of this study was to determine whether there are sex differences in electrocardiographic (ECG) measures and whether sex modifies the association of ECG measures of EP substrate with SCD.

Methods

Participants from the Atherosclerosis Risk in Communities study with analyzable ECGs (n = 14,725; age 54.2 ± 5.8 years; 55% female; 74% white) were included. EP substrate was characterized by heart rate, QRS, QTc, Cornell voltage, spatial ventricular gradient (SVG), and sum absolute QRST integral (SAI QRST) ECG metrics. Two competing outcomes were adjudicated: SCD and non-SCD. Interaction of ECG metrics with sex was studied in Cox proportional hazards and Fine-Gray competing risk models. Model 1 was adjusted for prevalent cardiovascular disease (CVD) and risk factors. Time-updated model 2 was additionally adjusted for incident nonfatal CVD. Relative hazard ratio (RHR) and relative subhazard ratio with 95% confidence interval (CI) for SCD and non-SCD risk for women relative to men were calculated. Model 1 was adjusted for prevalent CVD and risk factors. Time-updated model 2 was additionally adjusted for incident nonfatal CVD.

Results

Over median follow-up of 24.4 years, there were 530 SCDs (incidence 1.72; 95% CI 1.58–1.88 per 1000 person-years). Women compared to men experienced a greater risk of SCD associated with Cornell voltage (RHR 1.18; 95% CI 1.06–1.32; P = .003), SAI QRST (RHR 1.16; 95% CI 1.04–1.30; P = .007), and SVG magnitude (RHR 1.24; 95% CI 1.05–1.45; P = .009), independently from incident CVD.

Conclusion

In women, the global EP substrate is associated with up to 24% greater risk of SCD than in men, suggesting differences in underlying mechanisms and the need for sex-specific SCD risk stratification.

Occupational inequality in disability pension among persons with diabetes and comorbidity

Background

Persons with type 2 diabetes (DM2) have higher probability of an early exit from the labour market and to receive permanent disability pension compared with persons without DM2.

Objectives

To assess the association between occupational class and disability pension among persons without disease, with DM2 only and DM2 with six comorbid conditions (CVD, musculoskeletal disorders, mental disease, cancer, cerebrovascular disease and ≥2 comorbid diseases).

Methods

All employed persons aged 40-64 living in Denmark in the period 2011-2017(n, year 2011=1,454,649) were stratified according to DM2 and six major concomitant diseases. We estimated the relative risk of disability pension dependent on DM2 comorbidity status and occupational class by means of a log-binomial regression. Reference group was upper non manual employees with no disease.

Results

The highest risks of disability pension were seen for DM2 + mental disease, age 40-59 (RR = 2.45 [2.3-2.5]), DM2 + cerebrovascular disease (RR = 2.45 CI 95% [2.1-2.8]) and DM2 + ≥2 diseases (RR = 2.98 [2.9-3.1]). Unskilled and manual workers were more likely to receive disability pension. The occupational inequality was highest among younger persons and groups of persons with DM2 only and DM2 + CVD and lowest for persons with more than one concomitant disease.

Conclusions

The results suggest that among people with DM2, labour market exit depend on both comorbid conditions and occupational class. Overall, our results show that the relative effects of occupational class on disability pension decrease in cases with severe comorbid conditions. In younger persons the mechanisms may be more nuanced, suggesting that persons with DM2 + comorbid conditions in particular have difficulties fulfilling the working requirements of lower occupational jobs. Practitioners may use the results in targeting prevention interventions to persons in high risk of early labour market exit.

Key messages

Low occupational class and comorbidity increase the risks of disability pension among persons with DM2. Constrained work-flexibility of low occupational jobs may influence diabetes self-care and explain high inequality in disability pension.

A health inequality impact assessment of leveling down overweight and obesity

Background

Social differences in the proportion of overweight and obesity have increased in recent decades. Health impact assessments provide population-level valuations of changes in disease prevalence related to scenarios with different risk factors levels. These scenarios can be focused on reducing overweight and obesity among people with low socioeconomic position.

Methods

This study included the projected population of Copenhagen, Denmark in year 2040 (n = 742,130). Using the DYNAMO-HIA tool we conducted a health inequality impact assessment. Future prevented disease prevalence (IHD, diabetes, stroke, and multi-morbidity) and change in life expectancy related to an equalized scenario were estimated in a scenario where the prevalence of overweight/obesity (OWOB) in the group of people with short and medium educational attainment was reduced to the levels of people with long education.

Results

A higher proportion of people with short and medium education were OWOB than among people with long education and they had higher prevalence of cardiometabolic diseases. The diabetes prevalence among people with short education was reduced by 8-10% for men and 12-13% for women and life expectancy with diabetes decreased by one year in the group of women with short education. No notable effect of the equalized OWOB was seen regarding life expectancy with and prevalence of stroke and IHD.

Conclusions

Reaching the low prevalence of OWOB observed among people with high educational level, will reduce future cardiometabolic disease, increase life expectancy and meanwhile reduce the social inequality in health. These findings can serve as relevant references points for public health planners.

Key messages

This study is the first to combine advanced mathematical modelling and population data to assess changes in health from reducing socioeconomic inequality in obesity and overweight. These results propose valuable reference values for outcome assessments of interventions on inequalities in health.

QSAR-derived affinity fingerprints (part 1): fingerprint construction and modeling performance for similarity searching, bioactivity classification and scaffold hopping

An affinity fingerprint is the vector consisting of compound’s affinity or potency against the reference panel of protein targets. Here, we present the QAFFP fingerprint, 440 elements long in silico QSAR-based affinity fingerprint, components of which are predicted by Random Forest regression models trained on bioactivity data from the ChEMBL database. Both real-valued (rv-QAFFP) and binary (b-QAFFP) versions of the QAFFP fingerprint were implemented and their performance in similarity searching, biological activity classification and scaffold hopping was assessed and compared to that of the 1024 bits long Morgan2 fingerprint (the RDKit implementation of the ECFP4 fingerprint). In both similarity searching and biological activity classification, the QAFFP fingerprint yields retrieval rates, measured by AUC (~ 0.65 and ~ 0.70 for similarity searching depending on data sets, and ~ 0.85 for classification) and EF5 (~ 4.67 and ~ 5.82 for similarity searching depending on data sets, and ~ 2.10 for classification), comparable to that of the Morgan2 fingerprint (similarity searching AUC of ~ 0.57 and ~ 0.66, and EF5 of ~ 4.09 and ~ 6.41, depending on data sets, classification AUC of ~ 0.87, and EF5 of ~ 2.16). However, the QAFFP fingerprint outperforms the Morgan2 fingerprint in scaffold hopping as it is able to retrieve 1146 out of existing 1749 scaffolds, while the Morgan2 fingerprint reveals only 864 scaffolds.

European Academy of Neurology guideline on the diagnosis of coma and other disorders of consciousness

BACKGROUND AND PURPOSE

Patients with acquired brain injury and acute or prolonged disorders of consciousness (DoC) are challenging. Evidence to support diagnostic decisions on coma and other DoC is limited but accumulating. This guideline provides the state-of-the-art evidence regarding the diagnosis of DoC, summarizing data from bedside examination techniques, functional neuroimaging and electroencephalography (EEG).

METHODS

Sixteen members of the European Academy of Neurology (EAN) Scientific Panel on Coma and Chronic Disorders of Consciousness, representing 10 European countries, reviewed the scientific evidence for the evaluation of coma and other DoC using standard bibliographic measures. Recommendations followed the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. The guideline was endorsed by the EAN.

RESULTS

Besides a comprehensive neurological examination, the following suggestions are made: probe for voluntary eye movements using a mirror; repeat clinical assessments in the subacute and chronic setting, using the Coma Recovery Scale - Revised; use the Full Outline of Unresponsiveness score instead of the Glasgow Coma Scale in the acute setting; obtain clinical standard EEG; search for sleep patterns on EEG, particularly rapid eye movement sleep and slow-wave sleep; and, whenever feasible, consider positron emission tomography, resting state functional magnetic resonance imaging (fMRI), active fMRI or EEG paradigms and quantitative analysis of high-density EEG to complement behavioral assessment in patients without command following at the bedside.

CONCLUSIONS

Standardized clinical evaluation, EEG-based techniques and functional neuroimaging should be integrated for multimodal evaluation of patients with DoC. The state of consciousness should be classified according to the highest level revealed by any of these three approaches.

Dynamic predictive accuracy of electrocardiographic biomarkers of sudden cardiac death within a survival framework: the Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND

The risk of sudden cardiac death (SCD) is known to be dynamic. However, the accuracy of a dynamic SCD prediction is unknown. We aimed to measure the dynamic predictive accuracy of ECG biomarkers of SCD and competing non-sudden cardiac death (non-SCD).

METHODS

Atherosclerosis Risk In Community study participants with analyzable ECGs in sinus rhythm were included (n = 15,716; 55% female, 73% white, age 54.2 ± 5.8 y). ECGs of 5 follow-up visits were analyzed. Global electrical heterogeneity and traditional ECG metrics (heart rate, QRS, QTc) were measured. Adjudicated SCD was the primary outcome; non-SCD was the competing outcome. Time-dependent area under the receiver operating characteristic curve (ROC(t) AUC) analysis was performed to assess the prediction accuracy of a continuous biomarker in a period of 3,6,9 months, and 1,2,3,5,10, and 15 years using a survival analysis framework. Reclassification improvement as compared to clinical risk factors (age, sex, race, diabetes, hypertension, coronary heart disease, stroke) was measured.

RESULTS

Over a median 24.4 y follow-up, there were 577 SCDs (incidence 1.76 (95%CI 1.63-1.91)/1000 person-years), and 829 non-SCDs [2.55 (95%CI 2.37-2.71)]. No ECG biomarkers predicted SCD within 3 months after ECG recording. Within 6 months, spatial ventricular gradient (SVG) elevation predicted SCD (AUC 0.706; 95%CI 0.526-0.886), but not a non-SCD (AUC 0.527; 95%CI 0.303-0.75). SVG elevation more accurately predicted SCD if the ECG was recorded 6 months before SCD (AUC 0.706; 95%CI 0.526-0.886) than 2 years before SCD (AUC 0.608; 95%CI 0.515-0.701). Within the first 3 months after ECG recording, only SVG azimuth improved reclassification of the risk beyond clinical risk factors: 18% of SCD events were reclassified from low or intermediate risk to a high-risk category. QRS-T angle was the strongest long-term predictor of SCD (AUC 0.710; 95%CI 0.668-0.753 for ECG recorded within 10 years before SCD).

CONCLUSION

Short-term and long-term predictive accuracy of ECG biomarkers of SCD differed, reflecting differences in transient vs. persistent SCD substrates. The dynamic predictive accuracy of ECG biomarkers should be considered for competing SCD risk scores. The distinction between markers predicting short-term and long-term events may represent the difference between markers heralding SCD (triggers or transient substrates) versus markers identifying persistent substrate.

P5645Lifetime sex-specific sudden cardiac death prediction using ECG global electrical heterogeneity: the atherosclerosis risk in communities (ARIC) study

Background

Sex-based differences in sudden cardiac death (SCD) exist and screening methods for SCD are inadequate.

Purpose

To develop sex-specific lifetime risk prediction models using electrocardiographic (ECG) global electrical heterogeneity (GEH) and clinical characteristics.

Methods

Participants from the Atherosclerosis Risk in Communities study with analyzable ECGs (n=14,725; age, 54.2±5.8 yrs; 55% female, 74% white) were followed up for 24.4 years (median). Traditional ECG and GEH variables were measured on 12-lead ECGs. A Cox regression model was used to develop a prediction model. In women, the final model included race, age, coronary heart disease (CHD), stroke, hypertension, diabetes, smoking, high-density lipoprotein, albumin, uric acid, education level, heart rate, QTc, sum absolute QRST integral, spatial peak QRS-T angle. In men, the final prediction model included age, race, CHD, stroke, hypertension, diabetes, total cholesterol, physical activity, smoking, serum phosphorus, albumin, chronic kidney disease, spatial area QRS-T angle, area spatial ventricular gradient (SVG) elevation and magnitude, and peak SVG magnitude.

Results

There were a total of 530 SCDs. Our prediction models showed robust prediction of SCD in both sexes [(Harrell's C-statistic women 0.863 (95% CI 0.845–0.882), men 0.786 (95% CI 0.786–0.803)]. In women when ECG and GEH variables were added to clinical variables, the net reclassification improved by 9% (P=0.001) (Table). In men there was no significant reclassification improvement.

Net reclassification Lifetime SCD Risk: Clinical + ECG + GEH Variables Women Men <5% 5–15% >15% Total <5% 5–15% >15% Total SCD Cases <5% 82 14 0 96 103 16 0 119 5–15% 7 59 10 76 12 116 12 140 >15% 0 0 20 20 0 5 74 79 Lifetime SCD Risk: Total 89 73 30 192 115 137 86 338 Clinical Variables Only Non-Cases <5% 6,956 131 2 7,089 4,411 264 0 4,675 5–15% 180 509 42 731 210 1,059 48 1,317 >15% 0 28 84 112 0 56 214 270 Total 7,136 668 128 7,932 4,621 1,379 262 6,262

Conclusions

We were the first to develop sex-specific lifetime SCD prediction models. The addition of ECG GEH to clinical variables improved SCD risk reclassification in women, but not in men. Prediction of SCD was more accurate in women as compared to men.

Physico-chemical aspects of grape juices produced in the region of Campanha Gaucha, RS, Brazil (Southern Brazil)

The Campanha Gaucha region, southern Brazil, has received significant investments in Viticulture during the last decades, especially for the production of quality wines. However, implementing the production of American and hybrid grapes in this region constitutes and opportunity to supply the increasing demand of the grape juice market in Brazil. Juices of two varieties, “Bordô” and “Concord”, from two locations, Dom Pedrito and Santana do Livramento, were analysed in terms of the following physico-chemical aspects: total city, volatile acidity, density, pH, soluble solids content, color intensity, and hue. “Bordô” juices presented higher total acidity and did not differ in relation to location. Higher volatile acidity was found in “Concord” juice from Santana do Livramento. Higher pH was found in the variety “Concord” and in the location Dom Pedrito. For this same location, the “Concord” grape juices showed higher soluble solids values. Color intensity was higher in Santana do Livramento. Color hue was higher in Dom Pedrito. Both variety and location impacted significantly on physico-chemical aspects of grape juices, although all the grapes were produced within the Campanha Gaucha region.

Importance of the heart vector origin point definition for an ECG analysis: The Atherosclerosis Risk in Communities (ARIC) study

AIM

Our goal was to investigate the effect of a global XYZ median beat construction and the heart vector origin point definition on predictive accuracy of ECG biomarkers of sudden cardiac death (SCD).

METHODS

Atherosclerosis Risk In Community study participants with analyzable digital ECGs were included (n = 15,768; 55% female, 73% white, mean age 54.2 ± 5.8 y). We developed an algorithm to automatically detect the heart vector origin point on a median beat. Three different approaches to construct a global XYZ beat and two methods to locate origin point were compared. Global electrical heterogeneity was measured by sum absolute QRST integral (SAI QRST), spatial QRS-T angle, and spatial ventricular gradient (SVG) magnitude, azimuth, and elevation. Adjudicated SCD served as the primary outcome.

RESULTS

There was high intra-observer (kappa 0.972) and inter-observer (kappa 0.984) agreement in a heart vector origin definition between an automated algorithm and a human. QRS was wider in a median beat that was constructed using R-peak alignment than in time-coherent beat (88.1 ± 16.7 vs. 83.7 ± 15.9 ms; P < 0.0001), and on a median beat constructed using QRS-onset as a zeroed baseline, vs. isoelectric origin point (86.7 ± 15.9 vs. 83.7 ± 15.9 ms; P < 0.0001). ROC AUC was significantly larger for QRS, QT, peak QRS-T angle, SVG elevation, and SAI QRST if measured on a time-coherent median beat, and for SAI QRST and SVG magnitude if measured on a median beat using isoelectric origin point.

CONCLUSION

Time-coherent global XYZ median beat with physiologically meaningful definition of the heart vector's origin point improved predictive accuracy of SCD biomarkers.

Vectorcardiogram in athletes: The Sun Valley Ski Study

BACKGROUND

Global electrical heterogeneity (GEH) is associated with sudden cardiac death (SCD) in adults of 45 years and above. However, GEH has not been previously measured in young athletes. The goal of this study was to establish a reference for vectorcardiograpic (VCG) metrics in male and female athletes.

METHODS

Skiers (n = 140; mean age 19.2 ± 3.5 years; 66% male, 94% white; 53% professional athletes) were enrolled in a prospective cohort. Resting 12-lead ECGs were interpreted per the International ECG criteria. Associations of age, sex, and athletic performance with GEH were studied.

RESULTS

In age and training level-adjusted analyses, male sex was associated with a larger T vector [T peak magnitude +186 (95% CI 106-266) µV] and a wider spatial QRS-T angle [+28.2 (17.3-39.2)°] as compared to women. Spatial QRS-T angle in the ECG left ventricular hypertrophy (LVH) voltage group (n = 21; 15%) and normal ECG group did not differ (67.7 ± 25.0 vs. 66.8 ± 28.2; p = 0.914), suggesting that ECG LVH voltage in athletes reflects physiological remodeling. In contrast, skiers with right ventricular hypertrophy (RVH) voltage (n = 26, 18.6%) had wider QRS-T angle (92.7 ± 29.6 vs. 66.8 ± 28.2°; p = 0.001), larger SAI QRST (194.9 ± 30.2 vs. 157.8 ± 42.6 mV × ms; p < 0.0001), but similar peak SVG vector magnitude (1976 ± 548 vs. 1939 ± 395 µV; p = 0.775) as compared to the normal ECG group. Better athletic performance was associated with the narrower QRS-T angle. Each 10% worsening in an athlete's Federation Internationale de' Ski downhill ranking percentile was associated with an increase in spatial QRS-T angle by 2.1 (95% CI 0.3-3.9) degrees (p = 0.013).

CONCLUSION

Vectorcardiograpic adds nuances to ECG phenomena in athletes.

Mediolateral force distribution at the knee joint shifts across activities and is driven by tibiofemoral alignment

AIMS

Tibiofemoral alignment is important to determine the rate of progression of osteoarthritis and implant survival after total knee arthroplasty (TKA). Normally, surgeons aim for neutral tibiofemoral alignment following TKA, but this has been questioned in recent years. The aim of this study was to evaluate whether varus or valgus alignment indeed leads to increased medial or lateral tibiofemoral forces during static and dynamic weight-bearing activities.

PATIENTS AND METHODS

Tibiofemoral contact forces and moments were measured in nine patients with instrumented knee implants. Medial force ratios were analysed during nine daily activities, including activities with single-limb support (e.g. walking) and double-limb support (e.g. knee bend). Hip-knee-ankle angles in the frontal plane were analysed using full-leg coronal radiographs.

RESULTS

The medial force ratio strongly correlated with the tibiofemoral alignment in the static condition of one-legged stance (R² = 0.88) and dynamic single-limb loading (R² = 0.59) with varus malalignment leading to increased medial force ratios of up to 88%. In contrast, the correlation between leg alignment and magnitude of medial compartment force was much less pronounced. A lateral shift of force occurred during activities with double-limb support and higher knee flexion angles.

CONCLUSION

The medial force ratio depends on both the tibiofemoral alignment and the nature of the activity involved. It cannot be generalised to a single value. Higher medial ratios during single-limb loading are associated with varus malalignment in TKA. The current trend towards a 'constitutional varus' after joint replacement, in terms of overall tibiofemoral alignment, should be considered carefully with respect to the increased medial force ratio. Cite this article: Bone Joint J 2017;99-B:779-87.

In vivo hip joint loads and pedal forces during ergometer cycling

The rising prevalence of osteoarthritis and an increase in total hip replacements calls for attention to potential therapeutic activities. Cycling is considered as a low impact exercise for the hip joint and hence recommended. However, there are limited data about hip joint loading to support this claim. The aim of this study was to measure synchronously the in vivo hip joint loads and pedal forces during cycling. The in vivo hip joint loads were measured in 5 patients with instrumented hip implants. Data were collected at several combinations of power and cadence, at two saddle heights. Joint loads and pedal forces showed strong linear correlation with power. So the relationship between the external pedal forces and internal joint forces was shown. While cycling at different cadences the minimum joint loads were acquired at 60RPM. The lower saddle height configuration results in an approximately 15% increase compared to normal saddle height. The results offered new insights into the actual effects of cycling on the hip joint and can serve as useful tools while developing an optimum cycling regimen for individuals with coxarthrosis or following total hip arthroplasty. Due to the relatively low contact forces, cycling at a moderate power level of 90W at a normal saddle height is suitable for patients.

Synthesis and in vitro Antiviral Properties of Amphiphilic Dinucleoside Phosphate Derivatives of 2′,3-dideoxycytidine (ddC)

N4-hexadecyl-5′-0-(4-monomethoxytrityl)-2′-deoxycytidine-3′-hydrogenphosphonate and 5′-0-(4-monomethoxytrityl)-2′-deoxythymidine-3′-0-hydrogenphosphonate were condensed with 2′,3′-dideoxycytidine (ddC) according to the hydrogenphosphonate method to yield N4-hexadecyl-2′-deoxycytidylyl-(3′-5′)-2′,3′-dideoxycytidine (N4-hexadecyldC-ddC) and 2′-deoxythymidylyl-(3′-5′)-N4-palmitoyl-2′,3′-dideoxycytidine (dT-N4-palmddC). N4-palmitoyl-2′,3′-dideoxycytidine (N4-palmddC) was synthesized by reacting palmitic anhydride with ddC. Both dinucleoside phosphates have amphiphilic properties and represent a new class of ddC derivatives in which in the case of the dinucleosides, the ddC-5′-monophosphate is masked with lipophilic residues of variable stability. The ddC derivatives can be solubilized in water by micelle formation and, because they have lipophilic residues, they can be incorporated into the lipid membranes of liposomes. The ddC derivatives were shown to have antiviral activities comparable to those of AZT and ddC when tested in vitro against HIV-1-infected HeLa and H9 cells as well as infected human monocytes/macrophages.

Systematic selection of small molecules to promote differentiation of embryonic stem cells and experimental validation for generating cardiomyocytes

Small molecules are being increasingly used for inducing the targeted differentiation of stem cells to different cell types. However, until now no systematic method for selecting suitable small molecules for this purpose has been presented. In this work, we propose an integrated and general bioinformatics- and cheminformatics-based approach for selecting small molecules which direct cellular differentiation in the desired way. The approach was successfully experimentally validated for differentiating stem cells into cardiomyocytes. All predicted compounds enhanced expression of cardiac progenitor (Gata4, Nkx2-5 and Mef2c) and mature cardiac markers (Actc1, myh6) significantly during and post-cardiac progenitor formation. The best-performing compound, Famotidine, increased the percentage of Myh6-positive cells from 33 to 56%, and enhanced the expression of Nkx2.5 and Tnnt2 cardiac progenitor and cardiac markers in protein level. The approach employed in the study is applicable to all other stem cell differentiation settings where gene expression data are available.