Impact of prosthesis-patient mismatch on long-term survival in patients with small st jude medical mechanical prostheses in the aortic position

The impact of aortic prosthesis-patient mismatch (P-PtM) on long-term survival is unclear. Between 1985 and 2000, 388 patients at Mayo Clinic in Rochester, Minn, underwent aortic valve replacement (AVR) with 19- or 21-mm St Jude Medical prostheses and had transthoracic echocardiography within 1 year after AVR. Mean age of patients was 62+/-13 years; 69% were female. Prosthesis effective orifice area (EOA) was derived from the continuity equation. P-PtM was classified as severe (indexed EOA < or =0.60 cm2/m2), moderate (0.60 cm2/m20.85 cm2/m2). P-PtM was severe in 66 patients (17%), moderate in 168 (43%), and not hemodynamically significant in 154 (40%). Patients with severe P-PtM had a significantly larger body surface area (P