Severe haemolysis with the St. Jude Medical prosthesis

The St. Jude Medical prosthesis has become one of the most widely used mechanical heart valves because of its excellent haemodynamic function. Although subclinical haemolysis has been described with this prosthesis, there has only been a single report of frank haemolysis in the absence of a paravalvular leak. We report the occurrence of severe haemolysis in five patients following St Jude Medical prosthesis implantation, four of whom had combined aortic and mitral valve replacements. In no patient could the haemolysis be attributed either to a paravalvular leak or an obvious valve malfunction.