Transcatheter Mitral Valve Therapies

Abstract

The mitral valve is a complex apparatus and any structural change in this apparatus can lead to degenerative mitral valve regurgitation. Likewise, anatomical changes of the left atrium, mitral annulus, or left ventricle (LV) can lead to secondary or functional mitral valve regurgitation. Mitral regurgitation is frequent, increases with age and is the second common valve disease requiring surgery. Transcatheter valve interventions have emerged as an option to treat inoperable or high-risk patients who are not suitable for conventional open-heart surgery. Catheter-based devices and techniques can be grouped into those acting on the leaflets and sub-valvular apparatus, direct or indirect annuloplasty, and chamber remodeling. Based on the surgical Alfieri repair, there are “percutaneous mechanical sutures” for edge-to-edge repair. The MitralClip is the most used and is the only one incorporated into international guidelines. Then, there are devices designed to implant new synthetic chords or sutures fixing the leaflets to the LV. Other useful tools are annuloplasty devices, which try to decrease mitral regurgitation by reducing the annulus circumference, with subsequent improvement in leaflet coaptation. They can be divided into two types, direct and indirect. More recently prosthetic valves have also been designed for percutaneous implantation in patients who are not candidates for surgery.