Calcific stenosis of a mitral valve xenograft in a patient in chronic renal failure.

A 61 year old man presented with mitral regurgitation and glomerulonephritis caused by suspected infective endocarditis. His glomerulonephritis remitted on immunosuppression but mitral valve replacement with a Carpentier-Edwards porcine xenograft later proved necessary. The patient became dialysis dependent and cadaveric renal allografting was complicated by delayed graft function and refractory pulmonary oedema. Cardiac catheterisation showed severe calcification and stenosis of the xenograft with a transvalvar gradient of 23 mm Hg and despite emergency valve replacement the patient died. The valve had been in place less than five years. The rapid calcification and stenosis of a bioprosthetic heart valve calls into question the use of such prostheses in patients with chronic renal failure.