An apparatus for endovascularly replacing a patients heart valve is described. The apparatus comprises an expandable anchor which supports a replacement valve and a delivery catheter adapted to deliver the anchor and replacement valve to a vicinity of the heart. The anchor and replacement valve are adapted for percutaneous delivery and deployment to replace the patients heart valve. The apparatus further comprises a seal (380) adapted to prevent blood flow around the replacement valve when the anchor and replacement valve are fully deployed. The seal (380) comprises a pleated seal in the deployed configuration.
