Clinical durability of the pericardial xenograft valve: ten years experience with mitral replacement.

Data from 366 patients with mitral valve replacement (250 single and 116 multiple) who received pericardial xenografts between 1971 and 1981 were analyzed. Cumulative duration of follow-up was 1,151 patient-years, with a maximum duration of 10.7 years. Actuarial survival at 11 years is 71.6 +/- 14.2%. Pericardial valve failure occurred in 7 patients (0.6 episodes per 100 patient-years). Actuarial freedom from valve failure at 11 years is 90.4 +/- 9.1% for the entire series. Although 275 (75.1%) patients were in chronic atrial fibrillation, anticoagulants were not used in any patient beyond the first 6 postoperative weeks. The incidence of emboli was 0.6% per year. Six episodes occurred following single mitral valve replacement and 1 after multiple valve replacement (5 early and 2 late). The actuarial freedom from embolism in 96.4 +/- 1.5% at 6 and 11 years postoperatively. Valve thrombosis has not been encountered. This analysis has shown a low incidence of valve dysfunction and a very low risk of embolic complications without long-term anticoagulation. The pericardial xenograft is a safe substitute for the mitral valve, with predictable behavior during the first decade of follow-up.