Abstract 4138545: Mitral Valve Replacement is associated with favourable Functional and Clinical Outcome as compared with Restrictive Mitral Annuloplasty in Patients with Severe Ischemic Mitral Regurgitation. A prospective longitudinal analysis

Abstract

Background: Restrictive mitral annuloplasty (RMA) and chordal-sparing mitral valve replacement (MVR) are common options for treatment of chronic severe ischemic mitral regurgitation. Research question: in patients with severe ischemic mitral regurgitation the most effective surgical approach remains controversial Aim: to test whether MVR provides superior clinical and functional outcomes compared with RMA. Methods: a prospective longitudinal analysis on 187 patients (age: 66 ± 9 year; EF:35 ± 8 %) undergoing MVR or RMA and CABG for severe ischemic mitral regurgitation. Six-minute walking test and echocardiography were performed at preoperative baseline, at 1 year and at a median FU of 5 year (interquartile range: 2.9). Brain natriuretic peptide levels were also obtained. Mitral regurgitation was defined through a comprehensive and integrative approach. Recurrent mitral regurgitation was defined as a vena contracta ≥ 3 mm at follow-up, in patients with no persistent regurgitation at discharge. The primary outcome was a 5-year composite of all-cause mortality and rehospitalization for heart failure. Survival analysis was performed with Kaplan-Meier method. Cox regression analysis was used to verify any independent predictor of composite end-point Results: Baseline preoperative data were similar between the two group. Mitral valve replacement was performed in 49% of patients (n=92) and RMA in 51 % (n=95). At 5 year patients referred to prostheses showed significant improvement in six-minute walking test as compared to RMA (MVR: 290 ± 70 meters vs MRA: 165± 56 meters) (p > 0.01) ( Figure 1 ). The brain natriuretic peptide values did not differ between the two group at 1 year whereas were significantly lower in the MVR group at 5 years (MVR: 135 pg/ml; interquartile range:100 vs RMA: 486 pg/ml; interquartile range: 68 (p<0.01) ( Figure 2 ). At 5 years freedom from all-cause death and rehospitalization for heart failure was higher in the MVR group as compared to RMA (84 ±8.9% vs 61 ±12%, p<0.01) ( Figure 3 ). According to the Cox analysis recurrent mitral regurgitation was found to be a predictor of clinical outcome (HR:5.4, 95% CI:1.3-23.2, p= 0.023). Conclusions: In patients with severe ischemic mitral regurgitation referred for surgery, chordal- sparing MVR and CABG may improve functional capacity, clinical outcome and brain natriuretic peptide levels, compared with RMA and CABG. The impact of these findings remains to be defined by larger studies on longer term