Should bioprostheses be considered the valve of choice for dialysis-dependent patients?

There is controversy regarding the choice of prosthetic valves in patients with cardiac valve disease and dialysis-dependent patients. This review assesses a 12-year experience and outcomes after valve replacement in patients on chronic preoperative renal dialysis, comparing survival and valve-related outcomes following valve replacement with bioprostheses versus mechanical prostheses in this population in china.

From January 1999 and October 2011, 73 consecutive dialysis patients underwent cardiac valve replacement. The patients were divided into two groups: (Group B) bioprosthesis valves were implanted in 38 (52.1%) patients and (Group M) mechanical valves were implanted in 35 (47.9%) patients. Outcome measures included perioperative data, hospital mortality, major postoperative complications, follow-up outcomes, valve related morbidity and late survival.

There were no significant differences in terms of patient characteristics in the 2 groups. Thirty-three were isolated aortic valve replacements (45.2%); 28 were isolated mitral valve replacements (38.4%); 10 were combined aortic and mitral replacements (13.7%); 2 were combined tricuspid and mitral replacements (2.7%). The overall hospital mortality was 5.5% (n = 4) and was not different between Group B (5.3%) and Group M (5.7%). Low ejection fraction was the only independent predictors of hospital mortality. There was no significant difference between the groups in the overall rate of complications. The overall mean follow-up was 47 ± 23 months. According to the Kaplan-Meier analysis, late mortality, perivalvular leak and freedom from reoperation were similar in patients with mechanical and bioprosthesis valves. The bioprosthesis valve group had significantly higher freedom from thromboembelism-bleeding events (100% versus 77.6 ± 11.0%, p = 0.012), and valve-related morbidity (73.2 ± 10.1% versus 58.1 ± 10.9%, p = 0.035) in 5 years. Kaplan-Meier survival estimates at 1, 3, and 5 years were 0.971, 0.832, and 0.530 in group B, and 0.967, 0.848, and 0.568 in group M.

There is no significant difference in the perioperative morbidity and mortality, late survival of dialysis patients after cardiac valve replacement with bioprostheses versus mechanical valves. In spite of the limited sample size analyzed, its outcome and consistency to several previous reports supports a conclusion that bioprostheses rather than mechanical ones could be a favorable choice for valve replacement needs of renal failure patients.