Full Length ArticleClinical outcomes of venous thromboembolism with dalteparin therapy in multiple myeloma patients

- Anticoagulant therapy with dalteparin is efficacious in treating VTE in myeloma.
- Significant change of D-dimer levels was observed before the occurrence of VTE.
- D-dimer could serve as a surrogate marker for VTE recurrence in myeloma.

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.