ABSTRACT
New therapy for functional mitral regurgitation Heart failure is a major public health problem; nearly 5 million patients are under active treatment in the United States alone.1 The most significant etiology of congestive heart failure (CHF) is coronary artery disease leading to myocardial infarction, initiating left ventricular dilatation, which stretches the mitral valve annulus and chordae, eventually causing mitral regurgitation (MR). This class of MR is generally called functional MR or ischemic MR (IMR).2-4
It is estimated that 15% of the approximately 20 million CHF patients worldwide suffer from clinically significant MR (>2+ grade).5-11 The compound effect of MR in CHF patients is a serious problem with an extremely detrimental impact on survival.12-14 In the past 5 years there has been a growing recognition of the clinical significance of IMR and the potential benefits of appropriately timed correction.15-17 The current standard of care for heart failure patients with MR is open surgical valve repair via placement of an annuloplasty ring, or mitral apparatus reconstruction, or mitral valve replacement.5,18 Surgical mitral annuloplasty is designed to reduce the anterior and posterior annulus diameter and improve the co-aptation of the mitral valve leaflets, and therefore reduce MR.5,18,19 Mitral annuloplasty is generally effective in producing a durable reduction in mitral regurgitation. However, mortality rates associated with mitral valve surgery limit its application, particularly in the already compromised CHF patients who suffer differentially higher surgical morbidity and mortality.5,6,12,16,20,21 Over the past 5 years, a high procedure morbidity and mortality has propelled the development of various novel approaches, including both surgical and percutaneous means. This section will focus on the present status of a proposed alternative method, the percutaneous transvenous mitral annuloplasty
(PTMA) via a coronary sinus (CS) approach. These efforts are still in the pre-clinical stage.
