P977: the venous thromboembolism risk assesment models in multiple myeloma

Topic: 14. Myeloma and other monoclonal gammopathies - Clinical Background: Multiple myeloma (MM) increases the risk of thrombosis approximately 20 times, especially in the first 6 months, due to factors related to disease, patient and treatment such as monoclonal proteins, usage of central catheter, immobility, steroids, immunomodulatory drugs (IMIDs). There are some risk assesment models that predict venous thromboembolism (VTE) and the IMPEDE and PRISM scores have recently been developed in newly diagnosed MM (NDMM) patients. Aims: We aimed to reveal the incidence of VTE and its predisposing factors and survival rates in our NDMM patients and analyze the predictive power of new risk models. Methods: We included 150 MM patients with NDMM, treated and followed-up more than 6 months between January 2013 and June 2022. Results: VTE and pulmonary embolism (PE) developed in 12 patients (8%) during the first year of treatment within 150 patients. Mean and median days of VTE were 69.9 and 60 days, respectively. In 6 patients with deep venous thrombosis developed PE. One of these patients had VTE after central venous catheterization at the 8th month. Thrombosis prophylaxis such as acetylsalicylic acid, clopidogrel, low molecular weight heparin and direct oral anticoagulants (DOACs) was applied to 17 patients due to cardiac, cerebrovascular, peripheral arterial diseases, previous VTE and IMIDs. 65 patients had thromboprophylaxis during hospitalization in the first treatment cycle. While 76% of the patients had low IMPEDE score, 61.7% of 128 patients had low PRISM score. The mortality rate was 48% and the median time of survival was 36 months. No death due to thrombosis was observed. The PRISM score was statistically significant between groups with VTE and without VTE (p 0.021). In univariate logistic regression analysis; IMPEDE intermediate risk score was found to be more predictive than the low risk score in differentiating patients non-VTE (p 0.027) while none of the variables were found to be significant in predicting VTE in multivariate analysis. Median survival was 34 months in non-VTE group and 57 months in the VTE group in the Kaplan-Meier analysis but this difference was not found statistically significant (p 0.191).Summary/Conclusion: In our study we found the VTE incidence 8% in the first year of treatment median in 60 days, similar to the literature. However we could not demonstrate the survival benefit in the non-VTE group and advantage of the IMPEDE and PRISM risk scores in predicting VTE. We think that might be related to application of thromboprophylaxis during hospitalization and in the use of IMIDs, increasing mobilization with palliation of pain in daily practice and generally increasing the use of DOACs which could be consider a protective factor in treatment or prophylaxis the non-hematological indications. Keywords: Thromboprophylaxis, Multiple myeloma, Venous thromboembolism