Surgical Treatment of Severe Ischemic Mitral Regurgitation Marc Gillinov, heart surgeon in the Department of Cardiovascular Surgery in Cleveland Clinic’s Miller Family Heart & Vascular Institute, discusses the results of a randomized controlled trial from the Cardiothoracic Surgical Trials Network looking at the outcomes of surgery for severe vs. moderate mitral regurgitation caused by coronary artery disease.  Who should have bypass surgery, mitral valve repair, or mitral valve replacement?