Is ischemic mitral regurgitation an indication for surgical repair or replacement?

Ischemic mitral regurgitation (IMR) is common in patients with coronary artery disease. While it is well-known that IMR exerts a graded effect upon survival-the greater the degree of IMR, the lower the survival-the indications for surgical treatment and the choice of surgical procedure (repair versus replacement) are controversial. In patients with mild to moderate IMR, the benefit of a mitral valve procedure has not been demonstrated, and surgical practice varies. In patients with severe IMR, mitral valve surgery is the norm, but guidelines for choosing between valve repair and valve replacement do not exist. Furthermore, the survival impact of mitral valve surgery in patients with severe IMR is uncertain. When patients with severe IMR undergo mitral valve surgery, undersized annuloplasty results in durable repair in 70% to 85% of cases. Newly-developed adjunctive repair techniques may further improve results. Currently, mitral valve repair is the procedure of choice in the majority of patients having surgery for severe IMR. However, the most severely ill patients and those with certain echocardiographic characteristics (e.g. severe bileaflet tethering) should be treated with bioprosthetic mitral valve replacement rather than repair.