Patient prosthesis mismatch (PPM) was originally described by Rahimtoola almost four decades ago as follows: “the effective prosthetic valve area, after insertion into the patient, is less than that of a normal human valve”.1 That is, PPM is a situation in which the area of a perfectly functioning prosthetic valve is too small for the body surface area (BSA) of that patient. So, the indexed effective orifice area (IEOA) defined as the ratio between the effective orifice area (EOA) of a prosthetic valve and the BSA of that patient is the optimal parameter to calculate PPM.

Due to its ability to maintain high transvalvular pressure gradients, the existence of PPM can lead to adverse outcomes and worse quality of life. After the aortic valve replacement (AVR), these high-pressure gradients result in a slowing or absence of LV mass regression, which hampers LV function recovery and favours myocardial ischaemia even with normal coronary arteries due to increased myocardial demand and decreased coronary flow reserve (figure 1).2

During these four decades, a huge number of articles and reviews on the prevalence and clinical impact of PPM have obtained different results. Several reasons are responsible for these controversial findings. First, different …