Abstract 18767: Preoperative Echocardiographic Predictors of Left Ventricular Remodeling After Surgical Correction of Mitral Regurgitation Caused by Leaflet Prolapse

Abstract

Background: This study sought to determine whether preoperative echocardiography analysis before mitral valve surgery is predictive of postoperative left ventricular dysfunction in patients undergoing valve surgery for severe mitral regurgitation caused by leaflet prolapse. Methods: In 72 consecutive patients without coronary artery disease undergoing valve repair (n=29, 40%) or replacement (n=43, 60%), preoperative, early postoperative (1-2 days) and late postoperative (4.5 ± 2.5 months and 18 ± 8.0 months) echocardiographic parameters, including left ventricular (LV) dimensions, volumes and ejection fractions (EF) were measured. Patients were stratified and analysed in 3 different groups according to their respective baseline LVEF (group 1: EF ≥ 60, group 2: EF = 45-59%, group 3: EF < 45%). Results: Over a mean follow-up period of 546 ± 244 days, our cohort’s echocardiographic parameters showed the following reductions from baseline: LVEF: 56% ± 8 to 53% ± 9 (p<0.0001), LV end-diastolic dimension: 58.0mm ± 8.0 to 47.0mm ± 5.0 (p<0.0001) and LV end-systolic dimension: 41.0mm ± 8.0 to 33.0mm ± 6.0 (p<0.0001) respectively. Subgroup analysis revealed that only those with LVEF ≥ 60% recovered to a completely normal EF. Additionally, two-third of the observed changes in LV diameters and volumes occurred in the first 6 months. No difference in remodelling parameters was seen during the follow-up period between patients who underwent mitral valve replacement versus mitral valve repair. Finally, multivariate analysis demonstrated that pre-operative LVEF is an independent predictor of a poor post-operative LVEF (OR = 1.504 [1.249 - 1.966; p<0.0001]). Conclusions: In patients with pure severe mitral regurgitation due to leaflet prolapse, significant positive LV remodelling can be expected irrespective of patient’s baseline EF. Remodelling is more important in the first 6 months after surgery but is usually progressive and occurs over a long follow-up period (≥ 12 months); however, only those with baseline EF ≥ 60% will usually recover to a normal EF. This reinforces our understanding that contemplation of early surgical intervention for severe mitral regurgitation secondary to leaflet prolapse will most likely yield a favourable effect on LV remodelling.