Moderate ischemic mitral regurgitation: to treat or not to treat?

There is consensus of opinion that patients with moderately severe to severe (grade 3+ or 4+) ischemic mitral regurgitation (IMR) should undergo mitral valve surgery at the time of coronary artery bypass grafting (CABG), while trace to mild (grade 1+) IMR can probably be left alone. However, the management of moderate (grade 2+) IMR continues to be a subject of constant debate and controversy. In particular, as techniques of valvular repair continue to be refined; many surgeons have advocated mitral valve repair and concomitant CABG for these patients. Others, however, have continued to treat these patients with revascularization alone and close postoperative observation of the mitral valve. In their opinion, degree of concomitant mitral valve dysfunction in this group of patients does not justify the increased operative risks associated with simultaneous mitral valve correction. We are currently practicing in an era of evidence-based medicine (EBM) in which clinical decision-making has to be guided by current best available evidence from scientific, clinical studies. This review article attempts to tackle this controversial issue and find the best approach of dealing with moderate IMR at the time of CABG by evaluating current best available evidence.