Advances in percutaneous treatment of mitral regurgitation.

Percutaneous techniques for the treatment of mitral regurgitation have aroused much interest in recent years. Percutaneous mitral annuloplasty can be performed indirectly by using devices implanted in the coronary sinus or directly by using a retrograde approach. However, as yet, the results of these techniques are scarce and some devices have a high complications rate. The most frequent percutaneous mitral valve repair technique consists of mitral leaflet plication by implanting 1 or more percutaneous clips (MitraClip) in an imitation of the Alfieri surgical technique. Clinical experience with this device is broader than that with any other. The MitraClip device is associated with improved mitral regurgitation in a high percentage of carefully-selected patients. However, the single randomized study performed to date (EVEREST) showed its efficacy to be less than that of surgical repair and we await the results of new randomized studies that should clarify which patient-type can benefit most from this technique. Other left ventricular remodeling devices, tendinous cord implantation, and leaflet ablation are currently undergoing preclinical development or first-in-human experimentation. Finally, the development of biological prostheses for percutaneous mitral valve replacement is at an early stage. Many promising experiments at the preclinical phase and initial experiments in humans will very probably multiply in the near future. However, the true role of this technique in treating mitral valve disease will have to be evaluated in appropriately designed randomized controlled studies.