Safety of therapeutic anticoagulation in patients with multiple myeloma receiving autologous stem cell transplantation

The use of autologous stem cell transplantation (ASCT) for the treatment of multiple myeloma is increasing. Anticoagulation may be required during ASCT for conditions such as Hickman line thrombosis. The safety of anticoagulation in patients receiving ASCT is unknown. We report a retrospective case-control study of the safety of therapeutic anticoagulation in patients with multiple myeloma receiving ASCT. We identified 10 patients who received therapeutic anticoagulation during ASCT. For each of the 10 cases identified, two matched controls were selected. As a primary endpoint, bleeding complications were assessed. Secondary endpoints included survival, length of hospital stay, transfusion requirements, grade 4 toxicity, and days to platelet engraftment. Bleeding complications were not significantly different between patients receiving anticoagulation and controls (P = 0.3). Three of 10 anticoagulated patients and two of 20 controls had a bleeding complication. Mortality during admission was similar (P = 1.0); one anticoagulated patient and one control died of sepsis. A trend towards increased median number of platelet transfusions in the heparinized patients was seen (27 vs 12 units, P = 0.055), reflecting the higher transfusion threshold chosen for the anticoagulated patients. The other secondary endpoints did not differ between patients and controls. In this case control study, bleeding was not significantly increased in the group receiving anticoagulation during ASCT. This group electively received more units of platelets than controls. Thus, therapeutic anticoagulation can be managed with minimal increased toxicity during ASCT.