P185 | VENOUS THROMBOEMBOLISM IN MULTIPLE MYELOMA: ASSESSMENT OF THE CURRENT RISK MODELS AND THE ROLE OF HYPERCALCEMIA AS A POTENTIAL CONTRIBUTING FACTOR.

Background Patients (pts) with Multiple Myeloma (MM) have a 9-fold increased risk of venous thromboembolic events (VTE). Prophylaxis effectively reduces VTE risk and is initiated after applying two different scores: SAVED, which is validated for pts receiving immunomodulatory drugs (IMiDs), and IMPEDE-VTE, which has a dynamic use and doesn’t consider disease activity markers. Aims To estimate the incidence of VTE in a cohort of MM pts from our Center, evaluate the performance of SAVED and IMPEDE-VTE in this cohort and identify additional parameters that may be associated with VTE. Methods A retrospective analysis was conducted on 137 pts with newly diagnosed MM between 2017 and 2024. Clinical and laboratory data about disease and inflamamtory burden were collected at diagnosis. SAVED and IMPEDE-VTE scores were calculated. Pts already on anticoagulants at diagnosis (n=7) were excluded. Statistical analysis was performed using GraphPad Prism 10.4.1. Results The median age was 76 years (42–93). 6.5% of pts had an asymptomatic disease. The median follow-up time was 21 months (1-89). VTEs incidence was 6.9% (9/130): 2 cases were registered at diagnosis and 7 during therapy, with a median time to onset of 4 months (0-9). 4 VTE cases occurred in patients on prophylaxis, regardless of the ongoing anticoagulant drug. We observed a correlation between a high SAVED score and VTE events (p=0.032) in IMiDs exposed pts. Conversely, IMPEDE-VTE score did not demonstrate a direct correlation with VTE, likely due to the limited sample size. For the same reason, an association was found between VTE and established risk factors such as IMiD-based therapy, body mass index (BMI) and fractures, but did not reach statistical significance. We performed a univariate analysis among inflammatory and disease activity markers assessed at diagnosis, and we found a strong and significant association between VTE and hypercalcemia (p<0.001). Notably, 86% of patients who presented with hypercalcemia at diagnosis and later developed VTE had high calcium levels at the time of the thrombotic event, even if this occurred well after. No correlation was found between VTE and other CRAB criteria. Conclusion In our experience we evaluated the applicability of the current risk stratification tools for VTE in MM, and found that hypercalcemia at diagnosis may be an independent risk factor for the development of VTE. Prospective studies with larger cohorts are needed to validate this observation.