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

BACKGROUND: It is still unclear whether biological or mechanical valves should be preferred in patients on chronic dialysis therapy. PATIENTS AND METHODS: We retrospectively analyzed data from 104 patients (66.5 +/- 8.6 years) with end-stage renal failure (RF) who underwent aortic or mitral valve replacement between 2002 and 4/2008. Mechanical valves were implanted in 44 (42 %) patients and bioprostheses in 60 (58 %). The two groups were comparable with regard to preoperative data, age and incidence of additional CABG procedures. We studied in-hospital morbidity and mortality, major postoperative complications and length of ICU and hospital stay. Additionally, parameters predicting a poor outcome were analyzed with multivariate regression analysis.
RESULTS: The overall hospital mortality was 12.5 % and did not differ between the two groups (mechanical: 13.6 %, biological: 11.7 %, n. s.). In the postoperative course, duration of ventilation and ICU stay were similar, whereas hospital stay was significantly longer for patients with mechanical prostheses (19.5 +/- 5.4 vs. 15.6 +/- 4.1 days, P < 0.05). Mechanical valve patients had a significantly higher rate of postoperative cerebrovascular incidents (18.2 vs. 8.3 %, P < 0.05) and bleeding complications (15.9 vs. 11.7 %, P < 0.05). Reoperation, obesity, left ventricular ejection fraction < 30 % and previous neurological complications were independent predictors of hospital mortality.
CONCLUSIONS: Our results demonstrate that in patients with end-stage RF, the use of mechanical valves is associated with a significant risk of complications. Because of the poor overall survival of patients on dialysis, bioprosthesis degeneration will not be a limiting factor. Therefore, preference should be given to biological valves in these patients.