Left atrial reverse remodeling and functional improvement after mitral valve repair in degenerative mitral regurgitation: a real-time 3-dimensional echocardiography study.

BACKGROUND: Severe mitral regurgitation is often associated with left atrium (LA) enlargement, which is a well-known predictor of adverse cardiovascular outcomes. However, only few data are available on the effect of mitral valve (MV) repair on LA size. The aim of this study was to evaluate, using real-time 3-dimensional echocardiography, the changes in LA volumes after MV repair.
METHODS: A total of 65 patients with severe mitral regurgitation due to MV prolapse and scheduled for repair at an early stage were enrolled. Before the procedure, real-time 3-dimensional echocardiography was performed to assess LA volumes (maximum, before atrial active contraction [preA], and minimum). The same evaluation was repeated 6 months and 1 year after MV repair. Twenty healthy subjects matched for age and gender were enrolled as a control group.
RESULTS: Before MV repair, patients showed significantly higher values of LA volumes (maximum 43 ± 14 mL/m², preA 33 ± 12 mL/m², minimum 23 ± 11 mL/m²) as compared to controls (maximum 22 ± 6 mL/m², preA 13 ± 4 mL/m², minimum 8 ± 3 mL/m²). Six months after the operation, LA volumes significantly decreased (maximum 25 ± 8 mL/m², preA 18 ± 8 mL/m², minimum 13 ± 5 mL/m²), with a further reduction at 1-year follow-up (maximum 23 ± 7 mL/m², preA 15 ± 7 mL/m², minimum 11 ± 5 mL/m²), resulting in values similar to controls. The extent of LA reverse remodeling was inversely correlated with age (r = -0.42) and postoperative transmitral mean pressure gradient (r = -0.32), whereas a positive correlation was found with the reduction in left ventricular volume after MV repair (r = 0.35). DISCUSSION: In patients with severe mitral regurgitation due to MV prolapse, MV repair, when performed at an early stage, results in a significant LA reverse remodeling.