Prosthesis-patient mismatch (PPM) occurs when the Effective Orifice Area (EOA) of the implanted prosthesis is small in comparison of the patient’s body size and hemodynamic requirement.

PPM is well documented in aortic position and is associated poor clinical outcomes and higher mortality rates after aortic valve replacement. Strategies such as aortic root enlargement or choosing a prosthesis with larger EOAs prove to be helpful to avoid PPM in aortic position.

PPM in the mitral position is similar to having residual mitral stenosis causing persistent high mitral gradients, high left atrial pressure and increased pulmonary artery pressures. PAH may cause right sided heart failure, and high LA pressures my cause atrial fibrillation compromising cardiac output and increasing the risk of thromboembolic complications thus impacting the long-term survival of the patient.

The threshold values for mitral PPM are higher than that of aortic PPM. Indexed EOA of 1.2 or less demonstrates moderate PPM and an iEOA of 0.9 or less demonstrates severe PPM in the mitral position.

The best possible way to reduce the occurrence of PPM in the mitral position, is to implant a prosthesis with a larger EOA for a given annular size. This makes understanding of the documented EOAs of different available mitral prosthesis an effective tool in the treatment of patients with mitral valve disease.