Clinical and Doppler echocardiographic evaluation of bioprosthetic valve failure after 10 years. Four hundred thirteen consecutive patients underwent valve replacement with a bioprosthesis between 1976 and 1982. Aortic valve replacement was performed in 240 patients, mitral valve replacement in 132 patients, and multiple valve replacement in 41. The Carpentier-Edwards porcine (n = 336), Angell-Shiley porcine (n = 23), Hancock porcine (n = 11), and the Ionescu-Shiley pericardial valves (n = 43) were inserted. Follow-up between 5 and 12 years postoperatively was 98% complete. Freedom from structural valve deterioration was 72 +/- 7%, 59 +/- 9%, and 59 +/- 9%, respectively, after aortic, mitral, and double valve replacement. The risk of structural valve deterioration and reoperation for valve-related complications was significantly increased with the Ionescu-Shiley pericardial prosthesis. The risk for reoperation was inversely related to patient age. Postoperative Doppler echocardiographic studies in 87% of available patients revealed a subgroup of asymptomatic patients with evidence of structural valve deterioration. These patients (n = 61) had significantly reduced prosthetic valve areas (aortic less than 1 cm2, mitral less than 1.7 cm2), elevated resting transvalvular gradients (aortic greater than 40 mm Hg), or moderate-to-severe regurgitation. In summary, postoperative Doppler echocardiographic examination identified asymptomatic patients with structural valve dysfunction. These patients must be followed up carefully to determine the optimal timing of reoperation. 