Ischemic mitral regurgitation (MR) is a disease of the myocardium that disturbs the function of the mitral valve. IMR is the regurgitation seen with structurally normal valve leaflets that occurs in approximately 20% of patients after myocardial infarction and 56% of patients with congestive heart failure caused by ischemic or non-ischemic cardiomyopathy. The initiating event is an ischemic insult (heart attack) that results in remodeling of the left ventricle toward a more spherical shape. These changes lead to dilation of the mitral valve annulus, which prevents the mitral valve leaflets from closing completely during the contraction phase of the heart beat.
The size and location of the myocardial infarction (MI) sets into motion left ventricular remodeling that determines the severity, time course, and clinical manifestation of IMR. The presentation may be either acute or develop slowly over time in association with congestive heart failure (CHF).
Treatment options for IMR include revascularization, ring annuloplasty, valve repair and replacement, or left ventricular reconstruction by way of reshaping or resection. Medical therapy is also employed to improve symptoms of IMR.
Long-term prognosis is poor; therefore many thought leaders in cardiac surgery believe that a mitral valve procedure should be considered at the time of coronary artery bypass grafting (CABG). This surgical treatment essentially involves implantation of an artificial ring (annuloplasty ring) along with revascularization of the heart via coronary artery bypass grafting (CABG).
