Dr Rose honoured me with a request for a Foreword. I am delighted to oblige. The treatment of valvular heart disease has improved remarkably in the past 40 years. Many factors have contributed; not least being the introduction of artificial heart valves for treatment, more than 25 years ago. Their use has shown that they are good, but not an ideal substitute for native valves. A galaxy of pathological changes are associated with the insertion and malfunction of artificial heart valves. Each has to be defined, classified and related to clinical procedures or problems with a prosthesis; then a...