Thromboprophylaxis in Multiple Myeloma Patients on Immunomodulatory Agents: Single-Center Practice Patterns and Outcomes

PURPOSE Practice guidelines suggest two models (IMPEDE and SAVED) be utilized to stratify risk of venous thromboembolism (VTE) and determine the optimal thromboprophylaxis in patients with multiple myeloma (MM). Historical practice at the VA North Texas (VANTHCS) has been to preference aspirin for MM patients receiving induction therapy with immunomodulatory drugs (IMiDs). This study reviewed the rate of VTE in this population and examined the role of risk stratification models in determining need for anticoagulation versus aspirin thromboprophylaxis. METHODS Retrospective chart review of 329 patients diagnosed with MM between 2010 and 2022 was conducted. The primary outcome was incidence of VTE within six months of initiating IMiD-based induction therapy, stratified by IMPEDE and SAVED scores. Select secondary outcomes included predictive probability of IMPEDE and SAVED scores, thromboprophylaxis regimen utilized, and incidence of major bleeding. RESULTS A total of 248 patient inductions were included. Based on IMPEDE and SAVED scores, 100% and 76% of patients were classified as high risk, respectively, with 86% of patients receiving aspirin thromboprophylaxis. There was a 7.7% incidence of VTE within six months. Neither the IMPEDE (p = 0.55) or SAVED (p = 0.295) scores demonstrated predictive probability of VTE in this population. There was no statistical difference in the primary outcome between aspirin and anticoagulation (p = 0.3). Major bleeding occurred in 7.3% of the patients. CONCLUSION Overall incidence of VTE was low despite these populations being classified as high risk. Aspirin prophylaxis may be adequate VTE thromboprophylaxis in patients receiving IMiD-based induction regimens.