Prosthesis-patient mismatch in transcatheter and surgical aortic valve replacement.

Prosthesis-patient mismatch (PPM) occurs when the effective orifice area (EOA) of a normally functioning prosthetic valve is too small in relation to the patient's body size. The effect of PPM on outcomes and valve durability have gained credibility, making this an important possibly preventable risk factor. Transcatheter aortic valve replacement (TAVR) generally has a lower incidence of PPM than surgical aortic valve replacement (SAVR). Current surgical literature and randomized trials show an association between severe PPM and mortality in patients with SAVR but there is less evidence for an association with TAVR. Differences in the incidence of PPM may be related to the methods and cutoffs for measuring mismatch. This review will discuss the current state of field and propose standardization of measurement methods which may more accurately risk stratify patients.