Safety and efficacy of enoxaparin treatment in venous thromboembolic disease during acute leukemia.

Background: Venous thromboembolism (VTE) is a quite common complication in acute leukemia, although its real incidence is unknown. The best treatment of this complication is still a matter of debate due to the very high risk of hemorrhage in this group of patients.

Patients And Methods: From December 2000 to December 2002 four Caucasian patients with acute leukemia developed VTE complications. The patients were three men and one woman, mean age 55.7 years (range, 27-77). Two patients with acute lymphoid leukemia (L1 and L2 according to the FAB classification) developed deep venous thrombosis during the administration of chemotherapy; one patient with acute myeloid leukemia (AML, M2 according to the FAB classification) had pulmonary thromboembolism at diagnosis, while another AML patient (M4 according to FAB) showed deep venous thrombosis as the first symptom of leukemia. The clinical diagnosis of symptomatic VTE was confirmed by objective imaging procedures including lower limb venous color Doppler imaging in all cases and a ventilation-perfusion lung scan in one case. All patients were treated with enoxaparin 100 IU/kg subcutaneously twice daily for one month, followed by 150 IU/kg once daily for at least five months. When the platelet count was below 20,000 x 10(9)/L, the dose was reduced by 50%.

Results: During antithrombotic treatment neither VTE recurrences nor hemorrhagic complications or heparin-induced thrombocytopenia occurred. The platelet count at the beginning of enoxaparin treatment was very low (mean, 55,750 x 109/L; range, 12,000-121,000 x 10(9)/L) and treatment did not affect platelet recovery.

Conclusions: Enoxaparin proved to be efficacious and safe in the management of deep venous thrombosis with or without pulmonary embolism in patients affected by acute leukemia. Enoxaparin cured acute venous thrombosis, prevented recurrences and did not cause any hemorrhagic complications despite prolonged severe thrombocytopenia.