Gradient and pressure recovery of a self-expandable transcatheter aortic valve depends on ascending aorta size: In vitro study

Comparison of performance of self-expanding and balloon-expandable transcatheter aortic valves

“…Clinical, in vitro, and in silico studies have shown that TAV performance varies with valve type (self-expanding vs balloon-expandable), 2 , 3 , 4 , 5 the unique design of each valve within the same type group, 6 , 7 , 8 the deployment (axial and commissural), 9 , 10 , 11 and the surrounding patient-specific anatomy. 12 , 13 , 14 It is important to evaluate the flow downstream of the aortic valve because it instructs directly on the performance parameters and ultimately durability (after sufficient follow-up). The turbulence of the flow downstream of the TAV informs on the pressure drop across the valve and explains some of the reasons behind differences in pressure recovery among different valves, as identified by different measurement modalities such as echocardiography and catheterization.…”

Commentary: The importance of understanding fluid dynamics

“… 1 However, data on PR past different transcatheter aortic valve (TAV) models is relatively scarce. 2 In this issue of the JTCVS Open , Samaee and colleagues 3 have meticulously characterized, in a left heart simulator model, the fluid dynamics after implantation of an Evolut self-expandable Medtronic 26-mm transcatheter aortic valve. In addition, keeping other parameters constant, the influence of different ascending aorta diameters on the measured PR was also analyzed.…”

“…In addition, keeping other parameters constant, the influence of different ascending aorta diameters on the measured PR was also analyzed. 3 …”

“…Although this may be partially compensated by a greater PR in small ascending aortas, the pinwheeling effect on the cusps will affect the opening and closing mechanisms of the prosthetic valve cusps and increase leaflet fluttering during systole, which in turn may have important implications in long-term durability. 3 …”

Commentary: Does this model reality?

“…In this issue of the Journal , Samaee and coauthors 1 present a study on the effect of ascending aortic (AA) size on the hemodynamics and pressure recovery (PR) in self-expanding transcatheter aortic valves (SEVs). They placed a 26-mm Evolut R valve in a heart simulator flow loop with 3 different aortic sizes, 23 mm, 28 mm, and 34 mm.…”