Clinical and hemodynamic evaluation of the Quattro stentless mitral valve bioprosthesis. A 5 year follow up

Objectives: The chordally supported, Quattro stentless mitral valve bioprosthesis, has been designed to overcome the unsatisfactory durability and hemodynamic performance of stented bioprostheses in the mitral position. After promising early results, it was the objective of our study to evaluate the midterm results relating to valve performance and patient outcome.

Material and Methods: Since February 1997, 24 patients with mitral valve stenoses, underwent isolated valve replacement with the stentless Quattro valve, at our institution. The clinical outcomes of patients were followed up at yearly intervals. All pre- and postoperative echocardiograms were evaluated, with attention focused on the subvalvular apparatus, leaflet morphology and incidence of late mitral regurgitation.

Results: There were no cases of structural valve deterioration. The 5 year mortality rate was 12.5% (3/24). 3 patients suffered a stroke. There was one case of endocarditis. The mean gradient at 5 years was 4.8mmHg. The mean effective orifice area was 2.3 cm³. 41% of patients (10/24) developed late mitral regurgitation (mild n=5, moderate n=5). The site of regurgitation was located at the two commisures in all cases. In eight patients changes in left ventricular diameter had occurred.

Conclusions: With regards to hemodynamic performance and durability good clinical results can be achieved with this prosthesis. Midterm changes in left ventricular geometry seem to affect the competence of the stentless Quattro valve. The relatively high incidence of late mitral regurgitation and stroke remain worrying aspects.