[Can bioprostheses be implanted at younger ages?]

The choice between mechanical prosthesis (MP) and bioprosthesis (BP) depends on the respective advantages and disadvantages of the two types of valves. MP theoretically have an indefinite life span but carry the risk of thromboembolic events that requires anticoagulant therapy, which itself is responsible for hemorrhages. BP bear a theoretically lower thromboembolic risk but have a limited life span that requires reintervention at a subsequent date, latter when the patient is older at implantation and operated on for aortic replacement. Actually MP is preferred before 60 years and BP after 70 years. Between 60 and 70 years there is not consensus. The limit recommended is around 65 years for aortic replacement and 70 years for mitral replacement. This limit can change either for upper or lower limit depending on patient's life expectancy, technological improvements of MP as well as BP, improvements of medical follow up of anticoagulant therapy (either self testing or use of anti thrombin). In the future the age limit of implantation of BP can be lowered but MP didn't have their last word.