Fatal hemolysis due to unidentified causes following mitral valve replacement with bileaflet tilting disc valve prosthesis.

Fatal hemolysis after mitral valve replacement with the St. Jude bileaflet tilting prosthesis is reported in two patients. Although one underwent re-replacement of the valve, both died from multiple organ failure and acute renal failure, respectively. Scanning electron microscopy revealed microthrombi adherent to a leaflet in one and irregular leaflet surfaces in the other. Such defects are rare but are possible causes of hemolysis in patients with the St. Jude mitral valve prosthesis.