Multiple myeloma: retrospective assessment of routine thromboprophylaxis and utility of thrombotic risk scores.

Background: The high risk of venous thromboembolism (VTE) in multiple myeloma (MM) warrants primary thromboprophylaxis for most patients. Myeloma-specific thrombotic risk scores (TRSs), such as IMPEDE-VTE, SAVED, and PRISM, were developed to improve risk assessment and guide antithrombotic strategies. Their performance is variable and has not yet been tested in Latin America. Objectives: We aimed to assess the use of primary thromboprophylaxis, the incidence of VTE and bleeding events, and the effectiveness of TRSs in patients with newly diagnosed MM. Methods: This was a retrospective, single-center study. Cumulative VTE rates and TRS performance were analyzed using survival and receiver operating characteristic curves. Results: The study included 250 newly diagnosed MM patients; the vast majority (98.6%) received aspirin as thromboprophylaxis. VTE occurred in 8% within the initial 6 months, increasing to 14.8% over a median follow-up of 19 months. High rates of major bleeding (4.8%) and clinically relevant nonmajor bleeding (4.4%) events were documented. A minimal proportion (0.8%, 0.5%, and 1.2%) of patients were classified as low risk by IMPEDE-VTE, PRISM, and SAVED scores, respectively. Only IMPEDE-VTE exhibited a trend for distinguishing between intermediate-risk (7.14%) and high-risk (13.2%) groups ( Conclusion: Aspirin as primary thromboprophylaxis carries an unacceptable risk of VTE and bleeding in patients at intermediate or high thrombotic risk. The IMPEDE-VTE score performed best, although without reaching statistical significance. We confirm that VTE does not portend poor overall survival in MM.