Bioprostheses for cardiac valve replacement

Biologic tissue has been used successfully for cardiac valve substitutes since the introduction of glutaraldehyde preservation in 1969. Assessment of the clinical performance of prosthetic valves requires consideration of thromboembolism, anticoagulant-related hemorrhage, prosthetic valve endocarditis, periprosthetic leak and prosthesis failure. Two methods of assessment of valve performance, linearized occurrence rates and multiple decrement analysis of valve-related complications, are illustrated in evaluation of previous and new-generation Carpentier-Edwards porcine bioprostheses. The standard valve has a valve-related complication rate of 2.9% per patient-year over 5 years, while the rate for the new-generation supra-annular prosthesis is 4.3% per patient-year in the 2-year interval. Thromboembolism has been 1.6% and 1.7% per patient-year, respectively, for the previous and new-generation prostheses. Primary tissue failure has occurred only in the standard prosthesis, 0.6% per patient-year. The freedom from all valve-related complications is 93.1% at 2 years and 87.5% at 6 years with the standard valve and 95.1% at 2 years with the new-generation prosthesis. Standardized assessment of prosthetic performance should provide physicians and surgeons with the knowledge to optimize patient management. The new-generation biologic prostheses with improved preservation should reduce calcification and fatigue lesions. Tissue valves have afforded patients an excellent quality of life with a low incidence of valve-related complications.