Early results with composite strut caged ball prostheses.

The Starr-Edwards model 6400/10 mitral and 2400/10 aortic valve prostheses incorporate metallic tracks on the inner aspects of cloth-covered struts in an attempt to preserve the favorable thromboembolic performance of cloth-covered valves while avoiding the risk of cloth wear. Two hundred severity operative survivors of mitral valve replacement with the model 6400/10 prosthesis, all on continuous anticoagulant therapy, have been followed up for a mean period of 2.3 (maximal 6) years. The late survival rate is 91 percent and the removal-free rate is 94 percent at 5 years. The rate of embolism (mean +/- standard error of the mean) is 4.6 +/- 0.9 percent per patient-year. Significant bleeding complications occurred at a rate of 1.0 +/- 0.2 percent per patient-year; there were no deaths. Two hundred forty operative survivors of aortic valve replacement with a model 2400/10 prosthesis, all on continuous anticoagulant therapy, have been followed up for a mean of 2.0 (maximal 7) years. The 5 year survival rate is 84 percent and the removal-free rate is 98 percent. Embolism occurred at a rate of 3.3 +/- 0.8 percnet per patient-year. Hemorrhagic complications occurred at a rate of 2.1 +/- 0.6 percent per patient-year; there were three families. Cloth wear and hemolysis have not been significant problems with this prosthesis, and the rates of thromboembolism are comparable with those reported for xenograft bioprostheses. The composite strut (track) valve prosthesis is a durable alternative to tissue valves in patients who are able to tolerate anticoagulant therapy.