Edwards Lifesciences Corp. launched a pivotal trial of its mitral valve repair system in the U.S., with the first patient undergoing treatment for severe degenerative mitral valve regurgitation at the University of Maryland Medical Center in Baltimore. Open-heart surgery is the current standard approach to mitral valve repair, but the Harpoon Beating Heart mitral valve repair system allows surgeons to use a minimally invasive approach, according to Edwards Lifesciences.