1.1 This International Standard is applicable to all devices intended for implantation in human hearts, as a heart valve substitute. 1.2 This International Standard is applicable to both newly developed and modified heart valve substitutes and to the accessory devices, packaging and labelling required for their implantation and for determining the appropriate size of heart valve substitute to be implanted. 1.3 This International Standard outlines an approach for qualifying the design and manufacture of a heart valve substitute through risk management. The selection of appropriate qualification tests and methods are derived from the risk assessment. The tests may include those to assess the physical, chemical, biological and mechanical properties of heart valve substitutes and of their materials and components. The tests may also include those for pre-clinical in vivo evaluation and clinical evaluation of the finished heart valve substitute. 1.4 This International Standard imposes design specifications and minimum performance specifications for heart valve substitutes where adequate scientific and/or clinical evidence exists for their justification. 1.5 This International Standard excludes heart valve substitutes designed for implantation in artificial hearts or heart assist devices. NOTE A rationale for the provisions of this International Standard is given in Annex A.