title: Cardiac valve replacement: an unanswered question.
mesh_terms: D001022:Aortic Valve Insufficiency / Q000601:surgery; D005260:Female; D006350:Heart Valve Prosthesis; D006801:Humans; D008017:Life Expectancy; D008944:Mitral Valve Insufficiency / Q000601:surgery; D008946:Mitral Valve Stenosis / Q000601:surgery