Prosthesis-patient mismatch after "high-risk" aortic valve replacement.

S ince the initial description of prosthesispatient mismatch (PPM) more than 3 decades ago (1), the clinical import of PPM after surgical aortic valve replacement (SAVR) has been debated in the surgical published data. The phenotypic manifestation of PPM is an elevated aortic valve gradient after valve implantation. Although a number of indices have been used to characterize the frequency of PPM after valve replacement, the most common parameter used to describe its magnitude is the effective orifice area index (EOAi), which accounts for the body surface area (BSA) and, presumptively, the cardiac output. PPM is defined as moderate when the EOAi is #0.85 cm/m but $0.65 cm/m, and severe when the EOAi is <0.65 cm/m. PPM has been associated with higher early (2–5) and late mortality (4,6–10) after aortic valve surgery. In a meta-analysis comprising 34 studies that included 27,186 patients and 133,141 patient-years, both moderate and severe PPM increased all-cause mortality (hazard ratio: 1.19 and 1.84, respectively) and cardiac-related mortality (hazard ratio: 1.32 and 6.46, respectively); these relationships were consistent over time (11). The impact of PPM on late mortality may be influenced by the presence of older age, left ventricular (LV) dysfunction, New York Heart Association functional class III or IV symptoms, and concomitant coronary artery bypass grafting (12,13).