Can three-dimensional echocardiography accurately predict complexity of mitral valve repair?

OBJECTIVE: Feasibility of mitral repair is a key factor in the decision to operate for mitral regurgitation. Repair feasibility is highly dependent on surgical experience and repair complexity. We sought an objective means of predicting complexity of repair using three-dimensional (3D) transoesophageal echocardiography.

METHODS: In a cohort of 786 patients who underwent mitral valve surgery between 2007 and 2010, 3D transoesophageal echocardiography was performed in 66 patients with mitral regurgitation prior to the institution of cardiopulmonary bypass. The surgeon reviewed the 2D echocardiographic images for all patients pre-operatively, but did not view the 3D echocardiographic quantitative data or volumetric analysis until after surgery. Repairs involving no or a single-segment leaflet resection, sliding-plasty, cleft closure, chordal or commissural repair techniques were classed as standard repairs. Complex repairs were defined as those involving bileaflet repair techniques, requiring multiple resections or patch augmentation. Disease aetiology included Barlow's disease (n = 18), fibroelastic deficiency (n = 22), ischaemic (n = 5), endocarditis (n = 5), rheumatic (n = 2) and dilated cardiomyopathy (n = 2).

RESULTS: No patient required mitral replacement or had more than mild mitral regurgitation on pre-discharge echocardiography. Anterior and posterior leaflet areas, annular circumference, anterior and posterior leaflet angles, prolapse and tenting heights and volumes were most strongly predictive of repair complexity. As 21 of the 22 patients with bileaflet pathology and multisegment prolapse were complex repairs, we sought to develop a model predicting repair complexity in the remaining patients. The most predictive model with a c-statistic of 0.91 included three predictors: multisegment pathology, prolapsing height and posterior leaflet angle. After bootstrap validation, the revised c-statistic was 0.88.

CONCLUSIONS: 3D transoesophageal echocardiography provides an objective means of predicting mitral repair complexity in mitral regurgitation due to a range of aetiology.