Percutaneous treatment with Mitraclip for functional mitral regurgitation: medium-term follow up according to left ventricular function

BACKGROUND: Functional mitral regurgitation (FMR) is a bad prognosis condition despite optimal medical treatment. Nowadays there is an open debate about the surgical versus percutaneous treatment. The main objective of this study is to evaluate the mid-term follow up clinical outcomes of patients with FMR treated with MitraClip(®) system, according to their left ventricular ejection fraction (LVEF). METHODS: Data was obtained from two experienced centers in transcatheter mitral valve repair (TMVR). All consecutive cases of severe FMR undergoing TMVR in both centers with the same inclusion criteria were included prospectively in this study and followed-up. Periodical follow-ups with clinical and echocardiographic evaluation were scheduled from the baseline procedure, at 3 months and then yearly. RESULTS: From October 2015 to October 2019, a total of 119 patients with FMR at 2 centers in Spain underwent TMVR with the MitraClip(®) procedure and were included in this study. The mean age was 73.8±8.9 years old and 32 patients (26.9%) were female. A 39.5% of cases [47] had a LVEF ≤30% (group 1) and 60.5% (72 cases) had a LVEF >30% (group 2). There was a similar distribution in cardiovascular risk factors, age and other diseases. All MitraClip(®) implantations were elective and procedural success was achieved in 110 patients (92.4%) with a similar distribution between the groups. There were no differences in procedural time and the number of implanted clips. The median follow-up was 22.6 months (IQR, 11.43–34.98 months). The primary combined endpoint occurred in the 41.6% of the global cohort, 57.5% in group 1 and 30.99% in group 2 (P=0.036). LVEF was associated to the main event in the multivariate analysis (HR 2.09, 95% CI: 1.12–3.89; P=0.02). CONCLUSIONS: The MitraClip edge-to-edge technique is a safe and effective procedure for the treatment of FMR. In this study, patients with LVEF >30% treated with Mitraclip presented better clinical cardiovascular outcomes than those with a LVEF ≤30%. Regardless clinical outcomes, at the end of the follow-up, there was a sustained reduction in MR grades and an important improvement in NYHA functional class.