Left ventricular remodeling after mini-mitral repair-does the complexity of mitral disease matter?

OBJECTIVES: Degenerative mitral valve (MV) regurgitation (MR) is associated with left ventricular (LV) dilatation. Surgical treatment of MR has been shown to favorably affect LV remodeling. We prospectively compared the long-term echocardiographic outcomes of LV remodeling following mini-mitral repair for simple versus complex MV disease. METHODS: We prospectively followed up 203 consecutive patients who underwent mini-MV repair for severe degenerative MR over a 9-year period. Simple disease (n = 122 patients: posterior leaflet prolapse) was compared to complex disease (n = 81 patients: anterior, bilateral or commissural prolapse). Baseline demographics were similar between simple and complex groups (age: 63 ± 13 years vs 60 ± 15 years; p = .2; sex: 71% male vs 72% male, p = 1; preoperative MR grade ≥ 3+: 100%; n = 122; vs 100%; n = 81; p = 1), respectively. RESULTS: Preoperative left ventricular ejection fraction (LVEF) was significantly lower in the complex group as compared to the simple group (57.2% simple vs 56.0% complex; p = .04). Preoperative LV end-systolic diameter (LVESD: 35 mm simple vs 36 mm complex, p < .05) and LV end-diastolic diameter (LVEDD: 50 mm simple vs 51 mm complex; p < .05), as well as LV mass index (99.5 g/m2 vs 102.4 g/m2 ; p = .06) were larger in the complex group. Despite different baseline characteristics of LV function and geometry, both groups had similar remodeling of LV after MV repair. CONCLUSIONS: Patients with complex MV disease are referred late for surgical repair, causing LV function and dimensions to never fully recover. This suggests that earlier referral (before LV changes and potentially before symptoms) may be the preferred approach in those with complex disease.