Venous thromboembolism in patients with acute myeloid leukemia: development of a predictive model

Abstract Background Patients with acute myeloid leukemia (AML) are at increased risk of venous thromboembolic events (VTE). However, thromboprophylaxis is largely underused. Objectives This study aimed to determine possible VTE development risk factors and to develop a novel predictive model. Methods We conducted a retrospective cohort study of adult patients with newly diagnosed AML. We used univariate and multivariable logistic regression to estimate binary outcomes and identify potential predictors. Based on our final model, a dynamic nomogram was constructed with the goal of facilitating VTE probability calculation. Results Out of 626 eligible patients with AML, 72 (11.5%) developed VTE during 6 months of follow-up. Six parameters were independent predictors: male sex (odds ratio [OR] 1.82, 95% confidence interval [CI]: 1.077–2.065), prior history of thrombotic events (OR 2.27, 95% CI: 1.4–4.96), international normalized ratio (OR 0.21, 95% CI: 0.05–0.95), Eastern Cooperative Oncology Group performance status (OR 0.71, 95% CI: 0.53–0.94), and intensive therapy (OR 2.05, 95% CI: 1.07–3.91). The C statistics for the model was 0.68. The model was adequately calibrated and internally validated. The decision-curve analysis suggested the use of thromboprophylaxis in patients with VTE risks between 8 and 20%. Conclusion We developed a novel and convenient tool that may assist clinicians in identifying patients whose VTE risk is high enough to warrant thromboprophylaxis.