Influence of stentless versus stented valves on ventricular remodeling assessed at 6 months by magnetic resonance imaging and long-term follow-up.

Background: To compare the effect of stented versus stentless bioprostheses on left ventricular remodeling and assess their impact on long-term survival.

Methods: From January 2002 to December 2009, 62 severe aortic stenosis patients without coronary artery disease were randomized for bioprosthetic aortic valve replacement. After randomization, a cross-over was possible based on intraoperative data. Ventricular remodeling was studied by cardiovascular magnetic resonance imaging six months after surgery. Long-term survival was assessed by telephone survey.

Results: Thirty-five patients received a porcine Mosaïc Medtronic bioprosthesis (Stented Group; Medtronic, Minneapolis, MN, USA) inserted using the usual supra-annular technique and 27 received a porcine Freestyle Medtronic bioprosthesis (Stentless Group) inserted in the subcoronary position. Mean age was 75±3 and 73±4 years in the stentless and stented group, respectively. Nine patients who should have been implanted with a stentless bioprosthesis received a stented bioprosthesis for anatomical reasons. At 6 months, the left ventricular mass (LVM) decreased significantly in both groups (Stentless Group: 214.6±56.1g and 156.3±23g and Stented Group: 237±75.7g and 181±53.3g, respectively after surgery and at 6 months), this decrease was significantly greater in the stentless group (p=0.026). Reserve and coronary flow were increased in both groups at 6 months. Mean follow-up duration was 6.6±3.0 years and 7.2±4.0 years in the stentless and stented group, respectively. The 5-year actuarial survival was 87.5±11.7% and 82.5±17.1% for the stentless and stented group, respectively (p=0.81).

Conclusion: Porcine stentless prosthesis results in a better LVM regression than a stented valve at 6 months without changing the long-term survival.