Decreased hydraulic forces are incrementally associated with survival beyond conventional measures of diastolic dysfunction

BACKGROUND: Decreased hydraulic forces during diastole contribute to reduced left ventricular (LV) filling and heart failure with preserved ejection fraction. OBJECTIVES: To determine the association between diastolic hydraulic forces, estimated by atrioventricular area difference (AVAD), and both diastolic function and survival. We hypothesized that decreased diastolic hydraulic forces, estimated as AVAD, would associate with survival independent of conventional diastolic dysfunction measures. METHODS: Patients (n=11,734, median [interquartile range] 3.9 [2.4-5.0] years follow-up, 1,213 events) were selected from the National Echo Database Australia based on the presence of relevant transthoracic echocardiographic measures, LV ejection fraction (LVEF) ≥ 50%, heart rate 50-100 beats/minute, the absence of moderate or severe valvular disease, and no prior cardiac surgery. AVAD was calculated as the cross-sectional area difference between the LV and left atrium. LV diastolic dysfunction was graded according to 2016 guidelines. RESULTS: AVAD was weakly associated with E/e prime, left atrial volume index, and LVEF (multivariable global R2=0.15, p<0.001), and not associated with e prime and peak tricuspid regurgitation velocity. Decreased AVAD was independently associated with poorer survival, and demonstrated improved model discrimination after adjustment for diastolic function grading (C-statistic 0.645 vs 0.607) and E/e prime (C-statistic 0.639 vs 0.621), respectively. CONCLUSIONS: Decreased hydraulic forces, estimated by AVAD, are weakly associated with diastolic dysfunction and provide an incremental prognostic association with survival beyond conventional measures used to grade diastolic dysfunction.

Effect of the Membrane Composition of Giant Unilamellar Vesicles on Their Budding Probability: A Trade-Off between Elasticity and Preferred Area Difference

The budding and division of artificial cells engineered from vesicles and droplets have gained much attention in the past few decades due to an increased interest in designing stimuli-responsive synthetic systems. Proper control of the division process is one of the main challenges in the field of synthetic biology and, especially in the context of the origin of life studies, it would be helpful to look for the simplest chemical and physical processes likely at play in prebiotic conditions. Here we show that pH-sensitive giant unilamellar vesicles composed of mixed phospholipid/fatty acid membranes undergo a budding process, internally fuelled by the urea–urease enzymatic reaction, only for a given range of the membrane composition. A gentle interplay between the effects of the membrane composition on the elasticity and the preferred area difference of the bilayer is responsible for the existence of a narrow range of membrane composition yielding a high probability for budding of the vesicles.

PPP-BOTDA Distributed Optical Fiber Sensing Technology and Its Application to the Baishuihe Landslide

Serious landslide hazards are prevalent along the Yangtze River in China, particularly in the Three Gorges Reservoir area. Thus, landslide monitoring and forecasting technology research is critical if landslide geological hazards are to be prevented and controlled. Pulse-prepump brillouin optical time domain analysis (PPP-BOTDA) distributed optical fiber sensing technology is a recently developed monitoring method with evident advantages in precision and spatial resolution. Herein, fixed-point immobilization and direct burying methods were adopted to arrange parallel distribution of the strain and temperature-compensated optical fibers along the Baishuihe landslide’s front edge, in order to carry out ground surface deformation monitoring. The strain data acquired from both optical fibers were processed with temperature compensation to obtain the actual optical fiber strain produced by deformation. Butterworth low-pass filter denoising method was employed to determine the filter order (n) and cut-off frequency (Wn). The area differences between the two optical fiber monitoring curves and the fixed horizontal axis were selected as evaluation indexes to obtain the area difference along the optical fiber. This data were then leveraged to determine the positive correlation between the area difference and the optical fiber strain variation degree. Finally, these results were compared with the GPS and field measured data. This study shows that when PPP-BOTDA technology is used for landslide surface deformation monitoring in conjunction with Butterworth filter denoising and strain area difference, the optical fiber strain variation degree analysis results are consistent with the GPS monitoring data and the actual landslide deformation. As such, this methodology is highly relevant for reducing the workload and improving the monitoring precision in landslide monitoring, which in turn will protect lives and property.

Suggested New Statistical Parameter for Estimating Joint Roughness Coefficient considering the Shear Direction

The 10 standard roughness joint profiles provided a visual comparison to get the joint roughness coefficient (JRC) of rock joint surface, but the accuracy of this method is influenced by human factors. Therefore, many researchers try to evaluate the roughness morphology of joint surface through the statistical parameter method. However, JRC obtained from most of the existing statistical parameters did not reflect the directional property of joint surface. Considering the 10 standard profiles as models of different roughness joints, we proposed a new idea for the accurate estimation of JRC. Based on the concept of area difference, the average of positive area difference (Sa) and sum of positive area difference (Ss) were first proposed to reflect the roughness of joint surfaces on the basis of directional property, and their fitting relationship with JRC was also investigated. The result showed that the Sa and Ss calculated by shearing from right to left (FRTL) and JRC backcalculated from right to left (FRTL) came to a satisfying power law. The correlation between JRC and Sa was better than that of Ss. The deviation between the predicted value calculated by Sa and the true value was smaller than that obtained from the existing statistical parameters. Therefore, Sa was recommended as a new statistical parameter to predict the JRC value of joint profile. As the sampling interval increased from 0.5 to 4 mm, the correlation between Sa and JRC gradually decreased, and the accuracy of the prediction results also declined. Compared with the single JRC values for joint profiles mentioned in the literature, the forward and reverse JRC were obtained. Based on the laboratory direct shear test of the natural joint surface, the JRC values of two joint surfaces in four shear directions were backcalculated by the JRC-JCS model. Based on 3D scanning and point cloud data processing technology, JRC of joint surface in different directions were obtained by Sa method, and they are very close to those obtained by JRC-JCS model. It is confirmed that Sa could accurately estimate the joint roughness coefficient and reflect its anisotropy.

Abstract 294: Microrna-208a: A Marker of No-Reflow in STEMI Patients Undergoing Primary Percutaneuos Coronary Intervention

Background: Biomarkers are the corner stone for diagnosis of myocardial infarction (MI). MicroRNA-208a (miR-208a) is known to be heart specific. So, this study was designed to explore its role as a marker for diagnosis of MI as well as a predictor of outcome of primary percutaneuos coronary angiography especially no-reflow phenomenon. Methods: This study was carried out between January 2018 and August 2019 in Cardiology Department, Zagazig University Hospitals, Egypt. Approval was obtained from institutional review board adhering to the guidelines of the Declaration of Helsinki. Patients (n=75) presented by chest pain were recruited into two groups. Group 1 (n=40) had STEMI and underwent primary PCI: 21 patients with sufficient reperfusion and 19 with no-reflow. Group 2 (n= 35) had negative troponin T (cTnT). Plasma miR-208a expression was assessed using quantitative polymerase chain reaction and patients were followed for occurrence of in-hospital (3 days average) major adverse cardiac events (MACE). Results: Analysis of relative expression values shows that miR-208a has reasonable sensitivity and specificity for MI diagnosis (AUC= 0.92, sensitivity = 92.5, Specificity = 80) which is comparable to the routine cardiac biomarkers; creatine kinase-MB (CK-MB) (area difference 0.0439, P= 0.235) and cTnT (area difference 0.0614, P= 0.06). The no-reflow group (b) had higher expression compared to subgroup (a). ROC analysis shows it to be a good predictor of no-reflow (AUC= 0.88, sensitivity = 73.7, Specificity = 95.2) which is significantly superior to cTnT (AUC difference of 0.231, P= 0.0233). As well, it was superior to cTnT as a predictor of in-hospital MACE (AUC difference of 0.367, P= 0.0053). Conclusion: This study highlights the value of miR-208a as a diagnostic and prognostic marker in STEMI context. To the best of our knowledge, this is the first study to investigate the value of miR-208a in no-reflow and almost the second to investigate the role of any known miRNA in no-reflow. Although still far from clinical application due to long time needed for the assay, the future introduction of new fast nucleic acids assays could support its clinical application. The study points to a possible mechanism for no-reflow development that needs to be thoroughly investigated.