Multiple valve replacement increases the risk of reoperation for structural degeneration of bioprostheses

Background and aim of the study: The study aim was to analyze the results o f reoperations for structural degeneration of bioprostheses, and to define a highrisk population for reoperative procedures. Methods: A series of 524 consecutive patients who had undergone a first reo perative replacement for a failed bioprosthesis between 1978 and 1998 was r eviewed retrospectively. The reoperative procedure comprised 363 single val ve replacements, and 161 multiple valve replacements. During the original p rocedure, 648 bioprostheses had been implanted in the mitral (n = 403), aor tic (n = 220) and tricuspid (n = 25) positions. Results: The mean interval between the original procedure and reoperation w as 8.8 +/- 3.3 years. Tissue valve failure was revealed by recurrence of ca rdiac insufficiency in 70% of cases. The overall early mortality rate was 8 %, but early mortality rates for elective single mitral and aortic reoperat ive valve replacements were only 3.9% and 4%, respectively. Early mortality following reoperation for single and multiple valve replacement was 6.0% a nd 12.4% respectively (p = 0.02). Other significant multivariable predictor s for early mortality were old age (p = 0.003), NYHA functional class (p = 0.007), presence of ascites (p = 0.02) and reoperation performed before 198 8 (p = 0.013). Conclusions: The risk of reoperation for structural degeneration of biopros theses is acceptable for elective single reoperative valve replacement as o pposed to multiple reoperative valve replacement. This may limit the use of bioprostheses during the original procedure when multiple valve replacemen t is required.