Hemodynamic Behavior of Two 4^th Generation Aortic Valve Bioprosthesis during Exercise

Objective: Hemodynamic behavior of biological aortic valve prosthesis during exercise is essential for final valve judgement but is seldom performed. Opening characteristics of the prosthetic valve leaflets as well as the valve stent design itself contribute to maintain optimal pressure gradients during exercise, resulting in better hemodynamics. It was the aim of the present study to examine the in vitro opening behavior of two different aortic valve bioprosthesis (SJM Trifecta™, Edwards MagnaEase™) in a mock circulation at different flow levels.

Methods: To evaluate the different performances of the SJM Trifecta™, size 23mm (n = 4) and the Edwards MagnaEase™ size 23mm (n = 4) we used an aortic root model in which both valves types have been embedded for measurement in the mock circulation. Hemodynamic parameters (dpmean [mmHg], EOA [cm²], GOA [cm²]) were assessed stepwise at different flow levels (starting from 7.5 l/min up to 15 l/min).

Results: Hemodynamic behavior of the Edwards MagnaEase^TM was significantly inferior to the SJM Trifecta™ at higher flow levels (>10 l/min) with respect to all parameters being measured (p< 0.05). Opening of the valve as indicated by EOA and GOA was significantly more pronounced with the Trifecta aortic valve bioprosthesis (Fig. 1).

Fig. 1.

Conclusions: In our in vitro exercise model, the SJM Trifecta™ aortic valve bioprosthesis revealed a lower pressure gradient development when compared with another 4^th generation aortic valve bioprosthesis (Edwards MagnaEase™). This effect is presumably caused by the capability of an additional dynamic stent opening at higher flow rates, e.g., higher exercise levels.