“ LOS ANGELES -- Percutaneous mitral valve replacement may be on the horizon, first-in-man results suggest. [...] CardiAQ's percutaneous mitral valve is a self-positioning, self-anchoring bioprosthesis designed to address functional mitral regurgitation. Many other similar devices are in the works as well, but mitral valve replacement has proven slower to develop than aortic valve replacement. One of the challenges is the large size of the mitral valve compared with the aortic valve, requiring a larger system for delivery.