Implant heart valve devices, mitral valve repair devices and associated systems and methods

A method for repairing a native valve of a patient, the method comprising:

• positioning a heart valve repair device in a subannular position behind at least one leaflet connected to chordae tendineae, the repair device having a support in an unexpanded configuration;
• and
• expanding the support in the subannular position such that the support engages an interior surface of a heart wall and a downstream-facing surface of the at least one leaflet,
• wherein the repair device is configured to reposition the at least one leaflet into an at least partially closed position and brace the at least one leaflet such that the function of the native valve is improved,
• wherein, in the expanded arrangement, the repair device further includes an appendage extending beyond an edge of the at least one leaflet toward another adjacent leaflet.

A method of repairing a native mitral valve having anterior leaflet and a posterior leaflet between a left atrium and a left ventricle, comprising

• implanting a repair device having a support and an appendage under the posterior leaflet, wherein
• the support comprises an extension unit, and
• implanting the repair device under the posterior leaflet comprises implanting the extension unit under the posterior leaflet in an unexpanded state;
• and
• causing the support to press against a portion of an underside of the posterior leaflet and thereby push at least a portion of the posterior leaflet toward the anterior leaflet and extend the appendage beyond an edge of the posterior leaflet toward the anterior leaflet wherein causing the support to press against the underside of the posterior leaflet or engaging the underside of the posterior leaflet with the support comprises extending at least a portion of the extension unit such that the support presses against a wider portion of the posterior leaflet than in the unexpanded state.