Have We Found the Surgical Solution for Ischemic Mitral Regurgitation?

Abstract

The article by deVarennes et al in the current issue of Circulation details the outcomes in 44 patients with severe (4+) Carpentier type IIIb ischemic mitral regurgitation undergoing mitral valve repair consisting of posterior leaflet extension with bovine pericardium, coupled with remodeling annuloplasty, with or without coronary revascularization.1 Dissatisfied with the long-term results of annuloplasty alone, this group added posterior leaflet extension in an attempt to improve long-term mitral valve competency in this complex group of patients. Chronic ischemic mitral regurgitation (IMR), also referred to as functional mitral regurgitation (MR) is present in 10% to 20% of patients with coronary artery disease.2 It is associated with a markedly worse prognosis and is a common cause of congestive heart failure in this patient grouping. Critical in the discussion of this topic is a definition of the entity at hand. Borger et al put forth a concise definition of chronic IMR as follows: “Chronic IMR should be defined as mitral regurgitation occurring more than one week after MI with (1) one or more left ventricular segmental wall motion abnormalities; (2) significant coronary artery disease in the territory supplying the wall motion abnormality; and (3) structurally normal mitral valve leaflets and chordae tendineae.”3 Article see p 2837 Myocardial infarction sets in motion a cascade of events that can lead to mitral insufficiency. Among these are distortion and remodeling of the left ventricle, which displace the papillary muscles away from the mitral annulus. This phenomenon places excessive tension on the chordae, with the result being apical mitral leaflet tethering. The resultant restriction in leaflet motion …