Percutaneous treatment of mitral regurgitation: looking for a final model

Excerpt

Transcatheter mitral valve therapy (TMVT) has emerged as an alternative to surgery for treating patients with heart failure (HF) and primary or secondary mitral regurgitation (MR) [1, 2]. The most widely adopted technique, to date, is the edge-to-edge repair using the Mitraclip device. Among Mitraclip recipients, about 70% are affected by secondary (functional) MR [1, 2]. The distinction between primary and secondary MR is paramount. Primary MR is a valve’s disease, which can lead to left ventricular (LV) remodelling if not treated. Therefore, current guidelines recommend mitral valve surgery in patients with severe primary MR and symptoms and/or initial overload of left chambers [3]. In this setting TMVT (i.e. Mitraclip) can be considered as an alternative to surgery in patients deemed inoperable or at high-risk due to comorbidities, elderly age or frailty [3]. On the other hand, secondary MR is a ventricle’s disease in presence of a normal mitral valve anatomy. In the latter case, the presence of a cardiomyopathy (ischaemic or non-ischaemic) causes LV remodeling leading to a distortion of the mitral valve apparatus. The indications to treatment of isolated secondary MR are still controversial [3, 4]. Evidence for mitral valve surgery in patients with severe secondary MR who do not need revascularization is limited. According to the 2017 European Society of Cardiology (ESC) and European Association for Cardio-Thoracic Surgery (EACTS) Guidelines for the management of valvular heart disease, surgical treatment of severe symptomatic mitral regurgitation may be considered in patients at low surgical risk [3]. However, patients with functional MR have an inherent high surgical risk due to the LV dysfunction. In the Endovascular Valve Edge-to-Edge Repair Study (EVEREST II) trial, surgery had a similar 1-year efficacy, defined as freedom from death, MR recurrence or reoperation, compared with MitraClip in the patients with secondary MR whereas it was more effective in those with primary MR [5]. In this setting, TMVT may have a major role fulfilling an unmet treatment need. …