[Anticoagulation with low molecular-weight heparin in patients with prosthetic heart valve replacements].

In six patients with prosthetic heart valve replacement anticoagulation was performed with low molecular weight heparin for 4-58 weeks. The treatment was indicated because of one or more severe cerebral or gastrointestinal bleeding complications during therapy with oral anticoagulants or conventional heparin. The dose of the low molecular weight heparin ranged individually from 2,500 to 12,000 units once a day subcutaneously and was adjusted on the basis of the general bleeding tendency of the patient and the specific anticoagulant effect on factor Xa. Under this treatment no heart valve thrombosis occurred. Two minor bleeding complications were observed in two patients. All patients suffered previously from severe bleeding complications with conventional anticoagulants. One additional patient, who had been treated one year earlier with the low molecular weight heparin, again experienced embolism during treatment with only 1 X 5,000 anti factor Xa units per day. We conclude that anticoagulation with low molecular weight heparin may be recommended for patients with prosthetic heart valve replacement and severe bleeding problems with conventional anticoagulants. In patients with recurrent embolism higher doses should be administered.