Platelet activation is less enhanced in the new balloon expandable Edwards Sapien 3 valve compared to its predecessor model (Edwards Sapien XT)

SummaryStroke and thromboembolic events after transfemoral aortic valve replacement (TAVR) continue to be a problem. The aim of our study was to compare platelet aggregation (Agg) and platelet activation (PA) observed with two different catheter valves, the ESV-XT and the newer ESV-3 valve in patients (pts) undergoing TAVR on dual antiplatelet therapy (DAPT). A total of 174 patients with severe aortic stenosis and high surgical risk successfully underwent TAVR (60 ESV-XT; 114 ESV-3). Platelet Agg and PA (CD62P expression) were evaluated before and the following three days after TAVR under DAPT. Platelet Agg was inhibited to the same extent in both valve types and there was no significant difference in platelet drop between both valve types between day 0 and day 3 [ESV-XT vs ESV-3: median (25th-75th percentile): platelet count (x1000): 55 (42–74) vs 61(42–93), p=0.280]. However, there was an enhanced CD62P expression directly after TAVR with the ESV-XT compared to the ESV-3 [CD62P (MIF): 7.4 (6.8–8.6) vs 6.6 (6–7.9), p=0.014]. Surface expression of platelet CD62P was associated with the occurrence of residual aortic regurgitation (AR) and was significantly higher in patients with residual AR [CD62P (mild AR) vs CD 62P (no or trace AR): 7.9 (7.3–9.1) vs 7.1 (6.4–8.0), p < 0.001)]. PA was significantly enhanced in patients with the ESV-XT compared to the ESV-3 valve and was associated with the amount of residual AR which was significantly reduced by ESV-3. This may have implications for thromboembolic events following TAVR procedure

Abstract 13606: Platelet Activation is Less Enhanced in the New Balloon Expandable Edwards Sapien 3 Valve Compared to Its Predecessor Model (Edwards Sapien XT)

Aim of the study: Stroke and thromboembolic events after transfemoral aortic valve replacement (TAVR) continue to be a problem. The aim of our study was to compare platelet aggregation (Agg) and platelet activation (PA) observed with two different catheter valves, the ESV-XT and the newer ESV-3 valve in patients (pts) undergoing TAVR on dual antiplatelet therapy (DAPT). Methods and results: 174 pts with severe aortic stenosis and high surgical risk underwent successfully TAVR (60 ESV-XT; 114 ESV-3). Platelet Agg and PA (CD62P expression) were evaluated before and for the following 3 days after TAVR under DAPT. Platelet Agg was inhibited to the same extent in both valve types and there was no significant difference in platelet drop between both valve types between day 0 and day 3 [ESV-XT versus ESV-3: median (25th-75th percentile): platelet count (x 1000 ): 55 (42-74) versus 61(42-93), p=0.280]. However there was an enhanced CD62P expression directly after TAVR with the ESV-XT compared to the ESV-3 [CD62P (MIF): 7.4 (6.8-8.6) versus 6.6 (6-7.9), p=0.014 ]. Surface expression of platelet CD62P was associated with the occurrence of residual aortic regurgitation (AR) and was significantly higher in pts with residual AR [ CD62P (Mild AR) versus CD 62 P (no or trace AR): 7.9 (7.3-9.1) versus 7.1 (6.4 -8.0), p < 0.001)]. Conclusion: Although platelet inhibition was similar in both valve types, platelet activation was significantly enhanced in pts with the ESV-XT compared to the ESV-3 valve and was associated to the amount of residual AR which was significantly reduced by ESV-3, which may have implications for thromboischemic events following TAVR procedure.

Parameters Identification Strategy for a Generalized Vehicle Concept Model for Ride and Handling Analysis

In this paper we propose a structured approach for the parameters identification of a multibody vehicle concept model to be used for the combined analysis of vertical and longitudinal dynamics. The model here proposed adopts eight degrees of freedom in the space. The wheels are connected to the sprung mass in an equivalent trailing arm configuration thus enabling to reproduce the squat and dive phenomena. This conceptual suspension representation allows determining the dynamic response of the vehicle during longitudinal acceleration or braking maneuvers. The identification procedure here suggested evaluates the unknown parameters of the model, being the global stiffness and damping coefficients of the suspensions and the positions of the pivot points of the trailing arms. The identification algorithm is based on non-linear least square costs that can be computed by having as reference the signals of a measurement campaign which is conducted on a real vehicle as well as on a virtual predecessor model. The results here shown make use of virtually measured quantities coming from ride maneuvers performed by means of a high fidelity multibody model of a passenger car. The presented concept model, showing good correlation with respect to the reference signals, is suggested as a reliable prediction and optimization tool in the early stage of the design phase of new vehicles.

The Hitachi Model HS-8 Electron Microscope

By improving the predecessor Model HS- 7 electron microscope for the purpose of easier operation, we have recently completed new Model HS-8 electron microscope featuring higher performance and ease of operation.