Risk factors for venous thromboembolism in newly diagnosed multiple myeloma patients based on thrombosis prophylaxis.

This study aimed to explore risk factors for symptomatic venous thromboembolism (VTE) in newly diagnosed multiple myeloma (NDMM) patients, with particular focus on the moderating effect of age. A retrospective case-control study was conducted, and clinical and laboratory data from 309 NDMM patients were analyzed. Multivariable logistic regression and interaction analysis were employed to identify independent risk factors and assess age as an effect modifier. Age (OR = 1.060, 95% CI: 1.019-1.102), immobilization ≥ 72 h (OR = 2.835, 95% CI: 1.207-6.662), elevated D-dimer (> 0.55 mg/L) (OR = 2.294, 95% CI: 1.161-4.532), estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73m2 (OR = 2.088, 95% CI: 1.065-4.095), doxorubicin (OR = 4.760, 95% CI: 1.642-13.792), and dexamethasone 160 mg/cyc combined with immunomodulators (IMiDs) (OR = 2.758, 95% CI: 1.197-6.355) were independent risk factors for VTE (P < 0.05). Baseline anticoagulation (OR = 0.209, 95% CI: 0.049-0.896) and antiplatelet therapy (OR = 0.260, 95% CI: 0.132-0.511) served as protective factors (P < 0.05). Interaction analysis revealed that the effects of moderate-to-severe renal insufficiency and 160 mg/cyc dexamethasone-IMiDs combination were significantly modified by age (P for interaction < 0.05). The risk associated with renal insufficiency was amplified in older patients. The 160 mg/cyc dexamethasone-IMiDs combination increased VTE risk in younger patients but showed no significant association with VTE risk in older patients. Age significantly modifies the risk profile for VTE in NDMM. Notably, renal insufficiency poses a greater threat in older patients. Dexamethasone 160 mg/cyc combined with IMiDs exhibited varying effects across different age groups.