Cardiac valve replacement in patients with end-stage renal failure: impact of prosthesis type on the early postoperative course

Objectives: It is still discussed whether biological or mechanical valves should be used in patients on chronic dialysis therapy.

Methods: We 104 patients with end-stage renal failure (RF) who underwent aortic- or mitral valve replacement between 2002 and 4/2008. Mechanical valves were implanted in 44 patients (gr.m) and bioprostheses in 60 (gr.b). The groups were comparable with regard to preoperative data, age and incidence of additional CABG-procedures. We looked for the postoperative course in hospital, i.e. mortality, major postoperative complications, and length of ICU- and hospital stay. Additionally, with multivariate regression analysis, parameters predicting a poor outcome were analyzed.

Results: The overall hospital mortality was 12.5% and was not different between groups m (13.6%) and b (11.7%). In the postoperative course, duration of ventilation and stay on ICU were comparable between the groups, whereas hospital stay was significantly prolonged in group m (19.5±5.4 vs. 15.6±4.1 days, p<0.05).

Mechanical valve patients had a significantly higher rate of postoperative cerebrovascular accidents (18.2 vs. 8.3%, p<0.05) and bleeding complications (15.9 vs. 11.7%, p<0.05).

Reoperation, obesity, ejection fraction <30%, and former neurologic compliations were independent predictors of hospital mortality.

Conclusion: Our results demonstrate that in patients with end-stage RF, the use of mechanical valves is associated with a significant risk of complications. Overall survival is poor in both groups of patients. Because of the limited life expectancy of patients on dialysis, bioprosthesis degeneration will be uncommon. Therefore, preference should be given to biological valves in these patients.