In leukemia patients, antithrombotic medications (i.e. anticoagulation or antiplatelet therapy) are frequently prescribed for prior or new indications such as venous thromboembolism (VTE), stoke prevention in atrial fibrillation, or acute coronary syndrome (ACS). Balancing the risks of bleeding and thrombosis during periods of thrombocytopenia represents a significant challenge. The main management options include no change, temporarily withholding antithrombotic therapy, reducing dose, changing the regimen, and increasing the platelet transfusion threshold. Management is informed mainly by expert opinion and several recent retrospective studies on venous thromboembolism.
Important recent advances in knowledge include evidence showing an increased risk of arterial thrombosis in cancer, data on the prognostic importance and apparent safety of aspirin in ACS and acute leukemia, a study suggesting a low risk of recurrent VTE in autologous stem cell transplantation patients who had anticoagulation withheld, as well as evidence on factors driving management. Ongoing prospective studies are attempting to define the bleeding and thrombotic risk with various antithrombotic drugs in thrombocytopenic patients with hematological malignancy.
This lecture will review the short-term thrombotic risk associated with various indications for antithrombotic therapy, as well as the bleeding risk in the context of thrombocytopenia and leukemia. Considerations for practice and research will be discussed.