Remodeling of the mitral valve using radiofrequency energy: review of a new treatment modality for mitral regurgitation

Mitral regurgitation (MR) is a common valvular pathology with significant morbidity and mortality implications. Mechanical treatment of this condition is more effective than medical treatment and surgical correction has traditionally been the mechanical method of choice. Following major advances and wide acceptance of percutaneous interventions for coronary artery diseases, the field of valvular heart disease became an attractive target for transcatheter treatment modalities. Significant steps have been achieved in the field of percutaneous treatment of mitral stenosis as well as aortic stenosis, and lately, mitral regurgitation has been the focus of interest for many investigators looking for transcatheter solutions. Percutaneous edge-to-edge techniques and annuloplasty are innovative but have many disadvantages including the inability to reintervene and leaving a foreign body behind, respectively. Since the mitral and tricuspid annuli have dense collagen, a treatment modality targeting that collagen is logical. Observing the thermal effect on collagen, which causes conformational changes and shrinkage, radiofrequency energy was tested to evaluate its effect on the collagen-rich structure that is the mitral valve annulus. The potential of shrinking the mitral annulus by applying direct thermal source could be a promising modality for the treatment of mitral regurgitation with potential open and percutaneous applications. This paper presents an overview of the recent advances in transcatheter treatment of mitral regurgitation focusing on a new treatment modality that aims at reducing the mitral valve annulus diameter through the direct application of thermal energy using a radiofrequency energy probe.