Low-molecular-weight heparin for prosthetic heart valves: treatment failure.

There is no adequate substitute therapy for patients with prosthetic heart valves, in whom anticoagulation with warfarin or unfractionated heparin must be withheld. In the literature there are several reports describing successful treatment with low-molecular-weight heparin in patients with prosthetic heart valves. We report two cases of low-molecular-weight heparin treatment failure resulting in thrombosed prosthetic heart valves with stormy clinical presentations, who underwent successful valve replacements.