[Success of treatment with a low-molecular-weight heparin fraction in a case of pulmonary embolism complicated by heparin-induced thrombopenia].

A 40-year-old woman was admitted to Ambroise-Paré Hospital with a mitral stenosis and right ventricular failure. On the admission, heparino-therapy was started (Heparine Calcique Leo 30,000 IU/24 h); 11 days after, a thrombocytopenia (platelet count 60 . 10(9)/l) was observed and a few days later a pulmonary embolus was diagnosed. "In vitro", a heparin dependent plasma platelet aggregating factor was found (with Heparine Leo and all other standard ones tested) leading to the diagnosis of heparin associated thrombocytopenia; on the other this aggregating factor was not found with a low molecular weight (LMW) heparin fraction (Choay laboratory, Paris, batch CY216). We decided to stop standard heparin and to treat this patient with the LMW fraction (7,500 IU every 8 h SC) associated with oral antivitamin K. A rapid clinical improvement was observed and the platelet count rose progressively reaching 300 . 10(9)/l and has subsequently always been greater than 200 . 10(9)/l. The occurrence of heparin induced thrombocytopenia associated with thrombosis leads to heparin cessation; the treatment of the thrombotic episode seems to be improved by the use of LMW heparin associated with vitamin K antagonists.