Papillary muscle repositioning in mitral valve replacement in patients with left ventricular dysfunction.

Background: The aim of this study was to investigate the feasibility of performing papillary muscle repositioning for mitral valve replacement procedures in patients with left ventricular dysfunction and to determine the early and late effects of this procedure on clinical outcome and left ventricular mechanics.

Methods: One hundred patients with ejection fraction less than 40, who were candidates for isolated surgical correction of mitral insufficiency, had mitral valve replacement and were prospectively randomly assigned to either total chordal-sparing or papillary muscle repositioning. Fifty subjects underwent papillary muscle repositioning (PMR group), and the remaining 50 had complete preservation of all chordal structures with mitral valve replacement (CMVR group). Echocardiography was performed preoperatively, at discharge, and after 2 years to determine dimensions, left ventricular shape, and function.

Results: End-diastolic and -systolic volumes decreased in both groups initially and continued to decline. Decreasing volumes, however, were more significant in the PMR group, in which the significant decrease in the sphericity index continued for another 2 years. In contrast, the sphericity index in the CMVR group had no significant changes at discharge and at 2 years. In terms of systolic performance, ejection fraction had no significant changes in the CMVR group, whereas ejection fraction significantly increased in the PMR group.

Conclusions: Papillary muscle repositioning may result in more favorable left ventricular remodeling compared with complete retention of the mitral subvalvular apparatus during mitral valve replacement. It confers a significant early and late advantage by causing significant reductions in the left ventricular chamber volume, sphericity index, and systolic performance.