Long-term hemodynamic performance of bileaflet prostheses versus tilting-disc prostheses in the aortic position

Background: The aim of this study was to compare the long-term hemodynamic performances of Medtronic-Hall (MH) and ATS medical bileaflet (ATS) valves in the aortic position. Methods: We reviewed 249 patients that underwent AVR using MH or ATS valves between October 1994 and February 2004. MH valves were implanted in 117 patients (the MH group) and ATS valves in 132 patients (the ATS group). Serial changes in echocardiographic findings and clinical outcomes were analyzed. Results: No early mortality occurred, and the late valve-related mortality was 11.2% (28/249). The transaortic mean pressure gradient (TMPG) in the MH group increased more rapidly than that in the ATS group during follow-up. Concomitant mitral valve replacement (double valve replacement, DVR) and placement of small aortic prostheses (indexed effective orifice area less than 0.85 cm²/m²) were found to contribute to a postoperative increase in TMPG. No inter-group difference in cumulative survival was observed at 10 years (88.2± 3.1% vs. 84.7±3.1%, p=0.847). Cox regression analysis revealed that old age and DVR were predictors of late death, and that female gender, inclusion in the MH group and DVR were predictive of major adverse valve-related events (MAVREs). Conclusions: The MH group showed higher MAVREs than the ATS group and a relatively rapid increase in TMPG. Furthermore, DVR and placement of small prostheses were related to a late increase in TMPG irrespective of valve type.