Failures after Mitral Valve Repair for Functional Mitral Regurgitation: A Propensity Score Matched Analysis

Objectives: This study aims to evaluate and identify echocardiographic and surgical factors associated with failure after mitral valve repair leading to reoperation in patients with functional mitral valve regurgitation (FMR).

Methods: We analyzed our institutional mitral valve surgery database to identify patients with FMR who underwent surgical mitral valve repair and required mitral valve redo-surgery due to recurrence. Furthermore, a control group of FMR patients who had a stable postoperative result after mitral valve repair was identified based on 3:1 propensity score matching. Systematic analysis of echocardiographic parameters before primary surgery, after mitral valve repair and prior to redo surgery was performed and incorporated into multivariate cox regression analysis.

Results: A total of 1,735 patients underwent mitral valve repair at our center between March 2006 and September 2017. A total of 77 (4%) patients (mean age 60 ± 11 years, 61% male) who required redo mitral surgery following initial mitral valve repair were identified. Pulmonary hypertension (p = 0.02), mean transmitral gradient >5mmHg (p = 0.001), LVEF (p = 0.06), and MR grade at discharge (p = 0.02) were found to be associated with the need for redo surgery in the whole cohort. A total of 36 (47%) patients required reoperation due to recurrence of FMR. The underlying disease was predominant annular dilatation (Carpentier Type 1) in 54% (n = 20) and FMR Carpentier Type 3b in 46% (n = 16). Redo mitral surgery was performed at a median interval of 26 months (Min 3d, Max 22y). Re-repair could be performed in 7 patients (20%), while mitral valve replacement was required in 27 patients (75%) and transcatheter mitral valve-in-valve implantation (TMVI) in 2 patients (25.6%.) In-hospital mortality after redo surgery in the FMR cohort was 8.3%. Our multivariate analysis revealed a tendency toward significant association between preoperative LVEDD ≥65mm and need for redo surgery (HR 1.1, p = 0.11). Preoperative tenting parameter (i.e., PML-angle, tenting height ≥8 mm) were not significantly associated with the redo mitral surgery in the FMR cohort.

Conclusion: Isolated anuloplasty in functional mitral valve regurgitation is associated with a significant need for redo procedures due to FMR recurrence. Preoperative LV diameters were associated with an increased reoperation rate. Prospective quantification of FMR patients by LV geometry and tenting parameters is warranted to obtain better functional results.