Alloplastic materials have found wide application in heart-valve prostheses, in spite of the need for permanent anticoagulant treatment. Though biological valves exhibit excellent thromboresistance, they fail in long-term application because of a disintegration of the tissue structure. An improvement of the blood compatibility of implantable material has been achieved on the basis of an identification of interfacial reactions between clotting plasma proteins and the solid surface. Rutile ceramics offer advantageous properties because: (i) surface induced activation processes are diminished and (ii) the chemical and mechanical resistance shows long-term stability. Rutile ceramics are utilised for a central-flow heart-valve prosthesis which is being subjected to accelerated fatigue studies.