[Patient-prosthesis mismatch: myth or reality?].

Patient-prosthesis mismatch (PPM) is present when the effective valvular surface area of the prosthesis is too small compared to the patient's body surface area. PPM is a frequent problem following aortic valvular replacement (20 to 70%). PPM is associated with a lesser improvement in symptomatic state and quality of life, less regression in left ventricular hypertrophy, incomplete recuperation of coronary reserve, a higher incidence of adverse cardiac events, and reduced survival following aortic valvular replacement. However, the effect of PPM varies significantly depending on its severity and the patient's profile. Young patients in particular, as well as those with poor left ventricular function and/or severe left ventricular hypertrophy are more vulnerable to PPM. Unlike most of the other risk factors, PPM can be avoided or its severity can be more or less reduced by putting in place a prevention strategy at the time of the operation. This strategy should be oriented as a priority towards supra-annular implantation of modern prostheses, optimised on the hemodynamic front rather than leaning towards enlargement of the aortic root.