Effect of mitral valve repair on mitral-aortic coupling : a real-time three-dimensional transesophageal echocardiography study

BACKGROUND: The aortic valve and the mitral valve (MV) are coupled via fibrous tissue. Simultaneous dynamic analysis of the two valves' annuli has demonstrated that they have synchronous and reciprocal behavior. Accordingly, the aims of this study were to characterize mitral-aortic coupling (MAC) in three-dimensional space before and after MV repair and to identify the untoward effects of annuloplasty rings on MAC compared with normal valvular function. METHODS: Real-time three-dimensional transesophageal echocardiography was performed on 28 consecutive patients with degenerative MV disease and severe mitral regurgitation before and after MV repair and in 25 age-matched control subjects. Custom software was used to semiautomatically identify the mitral and aortic annuli throughout the cardiac cycle and to measure parameters describing valvular dynamics. RESULTS: Patients with mitral regurgitation before MV repair were characterized by altered morphology and function of the MV but preserved MAC because of the maintained ability of the mitral annulus to change size and position. MV repair together with annuloplasty ring implantation forced the mitral annulus to be smaller and less pulsatile, with decreased displacement ability compared with normal mitral annuli. Because of this alteration in MAC, the "unaffected" aortic annulus became less pulsatile and less mobile. CONCLUSIONS: This study shows unwanted and unexpected changes in aortic annular function secondary to mitral valve repair with an annuloplasty ring due to altered MAC mechanisms. These changes may alter the dynamic mechanism of the aortic root that facilitates blood ejection, so MAC should be considered and evaluated from diagnosis to treatment in MV disease