This study focused on the clinical outcomes in
multiple myeloma (MM) patients with
venous thromboembolism (VTE) who received
low-molecular-weight heparin (
dalteparin)
therapy. Changes in
D-dimer levels before and after VTE were also evaluated. Among 549 patients treated with various chemotherapeutic agents, a total of 52 (9.47%) patients including 32 newly diagnosed with MM and 16 with relapsed/refractory MM developed VTE, 48 of whom received
dalteparin. Among the 48 treated patients, 37 (77%) had proximal
deep vein thrombosis (DVT), four had (8%)
pulmonary embolism (PE), and seven (15%) had both DVT and PE. In 32 patients with available paired samples (at baseline and VTE occurrence), significant conversion of
D-dimer levels from 2.2 ± 0.4 mg/L to 11.8 ± 1.6 mg/L (P < 0.001) was observed, which decreased from 10.9 ± 0.4 mg/L to 1.9 ± 0.6 mg/L one month after initiating
dalteparin therapy. A total of 44 patients received
dalteparin with a median duration of 4.2 months (range, 2.7-9.4), and four patients were discontinued early due to death (n = 3) and major
bleeding (n = 1). After a median follow-up of 9.0 months (range, 0.7-35.8) since the first VTE episode, five patients showed recurrence of VTE with a cumulative incidence of 17.5 ± 7.9%. Major
bleeding occurred in three patients. In summary,
dalteparin seems to be a promising
drug for the treatment of VTE in MM. In addition, the significant difference in
D-dimer levels observed before occurrence of VTE and after
dalteparin treatment may suggest the usefulness of
D-dimer testing as a
surrogate marker for VTE in MM patients.