Long-term clinical and hemodynamic evaluation of the Ionescu-Schiley pericardial xenograft and the Braunwald-Cutter and Björk-Shiley prostheses in the mitral position.

Single mitral valve replacement was undertaken in 220 patients between March, 1971, and October, 1977. Bjork-Shiley prostheses (BS) were inserted in 42 patients, Braunwald-Cutter prostheses (BC) in 52, and Ionescu-Shiley pericardial xenografts (PX) in 126. No attempt was made at randomization. The actuarial survival rate was 81.9 +/- 12.8 percent at 7 years for patients with BS prostheses, 41.7 +/- 22.9 percent at 6 years for patients with BC prostheses, and 89.0 +/- 9.3 percent for patients with PX valves 7 years following valve replacement. Of the late deaths in patients with BC prostheses, 62.5 percent were valve related. The incidence of thromboembolism was 4.7, 1.8, and 1.5 episodes per 100 patient-years in the BS, BC, and PX groups, respectively. Long-term anticoagulation was used only in patients with BS and BC prostheses. Late postoperative hemodynamic studies were performed in six patients each with BS and BC prostheses and in 29 patients with PX valves. The mean diastolic gradients at rest were 6.2, 8.3, and 6.4 mm. Hg in the respective groups. The corresponding figures for calculated valve area were 1.8, 1.6, and 2.0 sq. cm. There was no statistically significant difference between the data recorded from the three groups of patients except for the survival rate of the BC prosthesis and the PX valve. The BS prosthesis and the PX valve have similar durability and hemodynamic performance for an almost identical duration of follow-up. Because of the improved quality of life and reduced morbidity without anticoagulants, we are using the PX valve exclusively for heart valve replacement.