Valve replacement surgery in end-stage renal failure: Mechanical prostheses versus bioprostheses

Background. The 1998 American College of Cardiology/American Heart Association Guidelines recommend mechanical prostheses for valve replacement in patients with end-stage renal disease requiring dialysis. The aim of the study is to evaluate the combined experience at two academic centers. Methods. Sixty-nine valve replacements (aortic 40; mitral 22; multiple 7, 47 bioprostheses, 22 mechanical prostheses) were performed. Total follow-up was 128.7 patient-years (bioprostheses, 68.4; mechanical prostheses, 60.4). Results. Patient populations were homogeneous, except for age (bioprostheses greater than mechanical prostheses, p = 0.012), previous myocardial infarction (bioprostheses greater than mechanical prostheses, p = 0.040), and concomitant CABG (bioprostheses greater than mechanical prostheses, p = 0.019). A survival advantage was observed in favor of mechanical prostheses (p = 0.0299) at 5 years. Freedom from valve-related complications at 5 years was calculated for thromboembolism plus thombosis plus hemorrhage (bioprostheses, 93.0% +/- 3.9%; mechanical prostheses, 76.4% +/- 12.7%), thromboembolism excluding thombosis (bioprostheses, 93.0% 3.9%; mechanical prostheses, 88.9% +/- 10.5%), and hemorrhage (bioprostheses, 100%; mechanical prostheses, 95.2% +/- 4.7%). One case of structural valve deterioration occurred in the bioprostheses group at 95 months after surgery. Five-year freedom from all valve-related complications was 82.8% +/- 8.1% for bioprostheses and 76.4% +/- 12.7% for mechanical prostheses. Conclusions. Overall survival was poor. Differences between populations were related to age at operation and coronary artery disease. Structural valve deterioration was not accentuated with bioprostheses. Considering lack of homogeneity between prostheses groups there was no superiority of mechanical prostheses over bioprostheses in terms of freedom from composites of complications. Bioprostheses should be considered in the management of valvular disease in end-state renal disease patients.