A method of treating a native mitral valve without open-heart surgery is disclosed. An expandable prosthesis includes an anchoring portion and an occluding member coupled to the anchoring portion. The prosthesis is loaded into a distal end portion of a delivery catheter and is advanced through a femoral vein and through a pre-made puncture in an atrial septum. The anchoring portion self-expands within the left atrium for anchoring the occluding member in a fixed position. The anchoring portion is preferably a laser cut structure that conforms to the left atrium and uniformly distributes anchoring forces within the left atrium. After deployment, the occluding member prevents blood from flowing from the left ventricle to the left atrium during systole. The occluding member is preferably made from a flexible material, such as pericardial tissue.