Functional Ischemic Mitral Regurgitation

Abstract

Ischemic cardiomyopathy is the most common cause of heart failure in the United States.1 This advanced form of coronary artery disease is marked by diffuse myocardial damage, left ventricular remodeling, and often functional ischemic mitral regurgitation (MR).2 Whether moderate functional ischemic MR in patients with ischemic cardiomyopathy should be addressed with mitral valve repair at the time of coronary artery bypass grafting (CABG) has been debated for a decade.3–7 Arguments against concomitant mitral valve repair are that CABG alone, by decreasing ischemia and improving left ventricular function, often decreases functional ischemic MR, and adding mitral valve repair to CABG increases operative complexity and risk. Arguments favoring concomitant mitral valve repair are that mitral valve repair consistently decreases functional ischemic MR, and CABG alone does not predictably improve postoperative MR. Article see p 1474 In this issue of Circulation , Penicka and colleagues8 present an elegantly designed and conducted study to help solve this surgical conundrum. They demonstrate that in patients with ischemic cardiomyopathy and moderate MR, the presence of preoperative myocardial viability in the areas adjacent to the papillary muscles and absence of papillary muscle dyssynchrony were associated with a reduction in MR after isolated CABG. This observational study included 135 patients with ischemic cardiomyopathy (ejection fraction <45%) and moderate MR who underwent CABG without mitral valve repair. Preoperative echocardiographic evaluation of functional ischemic MR included measurements of severity of MR based on the width of vena contracta and the ratio of regurgitant jet to left atrial area. Measurements of mitral valve tenting and displacement of mitral coaptation were used to assess changes in mitral valve geometry caused by left ventricular remodeling. Dyssynchrony between the papillary muscles was determined by …