Transvalvular velocities after full aortic root replacement: results from a prospective randomized trial between the homograft and the Medtronic Freestyle bioprosthesis

Background and aim of the study: Unstented bioprostheses offer better hemodynamics after aortic valve replacement. It has been reported recently that subcoronary implantation of the Freestyle valve may result in increased transvalvular velocities. In a prospective randomized trial, transvalvular velocities were investigated after implantation of a homograft or a Medtronic Freestyle bioprosthesis as a full root. Methods: A total of 137 patients was randomized to receive either a homograft (group H, n = 64) or a Freestyle (group F, n = 73) root replacement. Echocardiographic investigations were performed at six weeks, six months, and then yearly after surgery. Transvalvular and subvalvular velocities were recorded from each echocardiogram. Results: At follow up, none of the patients showed high transvalvular or subvalvular velocities (>2 m/s). At six weeks after surgery the transvalvular velocity was 1.5+/-0.3 m/s in group H (n = 51) and 1.7+/-0.3 m/s in group F (n = 56) (p = NS), while subvalvular velocities were 0.9+/-0.3 and 1.0+/-0.3 m/s, respectively (p = NS). These findings remained constant up to the three-year follow up, when transvalvular velocity was 1.6+/-0.4 m/s in group H (n = 10) and 1.6+/-0.2 m/s in group F (n = 15) (p = NS). Subvalvular velocities were 0.9+/-0.1 and 0.9+/-0.1 m/s, respectively (p = NS). Conclusion: Full aortic root replacement and reimplantation of the coronary arteries either with the Medtronic Freestyle or the homograft valve produces near-normal transvalvular velocities less than were reported for the Freestyle in the subcoronary implantation.