Fastener and techniques therefor

Apparatus for use with a contracting member that is flexible and elongate, the apparatus comprising:

• a fastener configured to receive the contracting member therethrough such that the fastener surrounds the contracting member, the fastener comprising a clamping structure that:
• (a) has an open state in which the contracting member can pass through the clamping structure, and
• (b) is biased toward assuming a closed state in which the clamping structure is configured to clamp onto the contracting member disposed therethrough;
• a stop removably coupled to the fastener in a manner that maintains the fastener in the open state;
• and
• a tool:
• comprising a cutting element;
• and
• configured to pull the stop proximally in a manner that moves the stop both:
• away from the fastener such that the stop becomes removed from the fastener, and
• against the cutting element such that the stop pushes the cutting element against the contracting member in a manner that severs the contracting member.

A method for use with a heart of a subject, the method comprising:

• advancing a tool distally along a flexible elongate contracting member, toward an anchor implanted at the heart, the tool including a cutting element;
• applying tension to the contracting member such that the contracting member slides proximally through a fastener disposed at the heart, while a stop is removably coupled to the fastener in a manner that maintains the fastener in an open state;
• and
• using the tool, pulling the stop proximally away from the fastener and against a cutting element of the tool in a manner that causes both:
• the fastener to clamp to the contracting member, thereby locking the tension in the contracting member, and
• the stop to push the cutting element against the contracting member to sever the contracting member.