Which of the following are not true?

B. Mitral valve replacement with either a bioprosthesis or a mechanical valve requires warfarin anticoagulation.

DISCUSSION: Tricuspid regurgitation due to annular dilatation alone generally can be treated with tricuspid annuloplasty or with correction of associated mitral valve disease. Mitral valve replacement with a mechanical valve does require warfarin anticoagulation; however, mitral valve replacement with a bioprosthesis may be managed with aspirin alone. Tricuspid valve replacement is an indication for using a tissue valve because of the significant incidence of valve thrombosis when a mechanical valve is in the tricuspid position. Chronic renal failure is a relative indication for tissue valves because valve calcification is rare and because anticoagulation of patients on dialysis carries high risks of morbidity and mortality.