Abstract
BACKGROUND: Ventricular functional mitral regurgitation (FMR) is a common morbidity in patients with heart failure (HF). In addition to guideline-directed medical therapy, mitral valve (MV) repair or replacement has become an option for such patients. However, the impact of different treatments on cardiac remodeling, function, and clinical outcomes remains unclear. METHODS: We systematically searched PubMed, EMBASE, Medline, Clinical Trials.gov, and the Cochrane Central Register of Controlled Trials with search terms related to mitral regurgitation, mitral valve repair, surgical mitral valve replacement, mitral annuloplasty device, and MitraClip. The outcomes were left ventricular ejection fraction (LVEF), left ventricular (LV) remodeling, all-cause mortality, cardiovascular death, and HF hospitalization. Sensitivity analysis was performed by removing high-bias risk studies. The analysis was done by Review Manager 5.4 Analyzer and MedCalc Statistical Software version 19.2.6. RESULTS: This meta-analysis included 10 studies with a total of 2533 patients (567 with transcatheter MitraClip, 823 with surgical MV repair, 651 with surgical MV replacement, and 492 with medical therapy). Our meta-analysis revealed that surgical MV repair had significant improvement in LVEF compared to the surgical MV replacement (mean differences (MD) 2.32, [95% CI 0.39, 4.25]), while transcatheter MitraClip treatment was associated with LVEF reduction (MD -4.82, [95% CI -7.29, -2.34]). In terms of LV remodeling, transcatheter MitraClip treatment was associated with improvement in left ventricular end-diastolic volume (MD -10.36, [95% CI -18.74, -1.99]). Furthermore, compared to surgical MV replacement, surgical MV repair was not associated with a reduction of all-cause mortality (risk ratio (RR) 0.83, [95% CI 0.61, 1.13]) and cardiovascular death (RR 0.95, [95% CI 0.56, 1.62]), while transcatheter MitraClip was associated with reduced risk of all-cause mortality (RR 0.87, [95% CI 0.78, 0.98]). CONCLUSIONS: Surgical MV repair was associated with significant improvement in LVEF but had no significant effect on all-cause mortality compared to surgical MV replacement. Transcatheter MitraClip was associated with better long-term survival than the non-MitraClip group, thus, transcatheter MitraClip could be considered an alternative treatment in patients with HF-complicated ventricular FMR.