[Choice of the prosthetic valve in patients aged between 55 and 70 years].

About 280 000 heart valve replacements are performed worldwide every year. Since the first prosthetic valve implantation in 1952 there have been notable developments. There are a lot of types of prosthetic valves that can be summarized into two categories: biological prosthetic valves or mechanical prosthetic valves. Biological prostheses, made of bovine or porcine pericardium, homografts, or autografts, degenerate over time becoming dysfunctional. Mechanical prostheses have a potentially unlimited lifespan but require oral anticoagulation which can affect patients' quality of life. Generally, biological prostheses are particularly suitable for elderly patients while mechanical prostheses for young people, with some distinctions. For example, in case of age <60 years, in the presence of preoperative oral anticoagulant therapy, metabolic syndrome, hemodialysis or hyperparathyroidism, a mechanical valve is the preference. The choice of the prosthesis in patients aged between 55 and 70 years is particularly challenging because the advantages and disadvantages of the two categories of prosthesis overlap in middle-aged patients. The choice of the prosthesis should be made after discussion with the surgeon, according to the patient's preferences, and keeping in mind the pros and cons of biological and mechanical prostheses.