Objective: The aim of this prospective randomized trial was to evaluate the impact of complete supraannular positioning of mechanical aortic bileaflet valves.
Methods: Between April of 2004 and November of 2006, 80 patients underwent aortic valve replacement with the complete supraannular Medtronic Advantage Supra (n = 40) (Medtronic Inc, Minneapolis, Minn) or the intra-supraannular St Jude Medical Regent (n = 40) prosthesis (St Jude Medical Inc, St Paul, Minn). Before randomization and valve sizing for both valve types, the aortic tissue annulus diameter was determined by Hegar dilator. Transthoracic echocardiography data were obtained early postoperatively and at 6 months, including stress echocardiography.
Results: By grouping the data on the basis of a patient's tissue annulus diameter, no significant difference of either valve was detected with regard to mean pressure gradient and effective orifice area index at rest. Effective orifice area index ranged from 0.95 +/- 0.32 cm(2)/m(2) to 1.27 +/- 0.33 cm(2)/m(2) in the Advantage Supra group and from 0.98 +/- 0.36 cm(2)/m(2) to 1.26 +/- 0.37 cm(2)/m(2) in the Regent group. During exercise, mean pressure gradients increased from 11.9 +/- 4.9 mm Hg to 19.1 +/- 7.2 mm Hg in the Advantage Supra group and from 9.6 +/- 4.0 to 16.4 mm Hg +/- 7.3 mm Hg in the Regent group. A marked left ventricular mass regression across all annulus sizes was noted in both groups (P < .001). Sizing for both valve types showed that in 26.3%, the completely supraannular valve design allows the implantation of a 1 size larger valve in label than the corresponding intra-supraannular valve.
Conclusion: By grouping the data on the basis of a patient's tissue annulus diameter, no significant superiority of either prosthesis was detected with regard to left ventricular mass regression, effective orifice area index, and mean pressure gradient during rest and exercise. We conclude that there is no additional benefit of supraannular valve positioning.