Session S21.3

Quantitative Assessment of Changes in Left Ventricular Shape following Mitral Valve Repair

F Maffessanti*, G Tamborini, F Muratori, M Zanobini, V Mor-Avi,
L Sugeng, F Alamanni, RM Lang, M Pepi, EG Caiani

Politecnico di Milano
Milano, Italy

Aim: Myxomatous degeneration is the most common cause of pure mitral valve (MV) regurgitation with leaflet prolapse due to chordal lengthening or rupture. MV repair combined with ring annuloplasty, allowing the preservation of the valvular apparatus, has become the preferential treatment for MV prolapse. Our goal was to evaluate pre- and post-operative LV function and morphology after MV repair and annuloplasty, using new custom software for 3D shape analysis from real-time 3D echocardiographic (RT3DE) images.
Methods: 50 patients (36 M, age 59±12) with MV prolapse and ejection fraction (EF)>55% undergoing MV repair, were enrolled. An age-matched group of 66 normal (NL) subjects (45 M, age 55±11) were prospectively studied. RT3DE transthoracic imaging (Philips) was performed the day before the intervention, 6 months and 1 year later. LV endocardial surfaces were extracted (TomTec) and used to compute LV 3D shape indexes of sphericity (S) and conicity (C). End-diastolic and end-systolic LV volumes, EF and S and C indices were compared at each phase of the study. Moreover, results from the MV group were compared with those obtained in the NL group.
Results: Post-operative LV volumes were decreased compared to pre-surgery values both at ED (pre: 73±22; 6m: 54±13; 12m: 56±13, ml/m2) and at ES (pre: 28±10; 6m: 24±8; 12m: 23±7, ml/m2). EF was found slightly decreased 6 months after MV repair, but was restored to pre-surgery values after 1 year (pre:61±6; 6m:56±6; 12m:59±6, %). Functional changes were followed by modifications in ED LV shape, with permanently decreased S (pre: .67±.05; 6m: .64±.04; 12m: .63±.05) and increased C (pre: .76±.03; 6m: .79±.03; 12m: .79±.03) values. In the MV group, index S was found higher while C was smaller than in the NL group, even if a trend toward NL values was noted after MV repair.
Conclusion: Early MV repair appeared not only to preserve LV systolic function but also to reduce LV volume and mass. This remodeling process was accompanied by shape changes in LV, especially at ED, due to the decreased overload, leading to both functional and morphological restoration of normal values. This combined approach could allow a more detailed examination of the complex pre and post-operative relationship between function and shape.

(Abstract Control Number: 192)