The changing spectrum of bioprostheses hydrodynamic performance: considerations on in-vitro tests

The aims of the present study were to compare hydrodynamics of three pericardial and two porcine valves while performing at different stroke volume (SV) and increasing pulse rate (PR). Carpentier-Edwards Magna-21 (CEM), Sorin Soprano-20 (SS), Mitroflow-23 (MF), SJM-Biocor-Epic-Supra-21 (SJME), and Medtronic Mosaic Ultra-23 (MMU) were tested in the aortic chamber (23-mm in diameter) of the Sheffield-Pulse-Duplicator. The tests were carried out at increasing pulse-rate and at each pulse-rate the valve was tested at different SV. CEM and MF showed significantly lower gradients than porcine valves and SS. Transvalvular gradients were unrelated to PR showing a constant value with increasing PR. While SJME valve showed the lowest regurgitant volume, on the contrary CEM showed the highest. At increasing SV, effective-orifice-area (EOA) observed with CEM was significantly larger than with the other tested valves, even though at SV 60 ml MF was comparable and at SV 65 ml significantly better. SS, SJME and MMU showed comparable EOAs with bigger area at increasing PR. The latter relation was reversed for CEM and MF. Our results show that CEM and MF have shown significantly better in-vitro hydrodynamics in comparison with their porcine counterpart and SS. Nevertheless, at increasing pulse rate, porcine tissue valves and SS may guarantee higher EOA values.