Establishment and validation of a 28-day clinical outcome prediction model for acute promyelocytic leukemia based on an early platelet-coagulation factor combined transfusion strategy.

Early mortality in acute promyelocytic leukemia (APL) remains a major challenge, and the Sanz risk stratification has limited predictive value. This retrospective multicenter study aimed to establish and externally validate a 28-day mortality risk prediction nomogram integrating an early platelet-coagulation factor (PLT-CF) combined transfusion strategy. A total of 631 newly diagnosed APL patients from two tertiary hospitals (2019-2024) were divided into a training cohort (n = 429) and an external validation cohort (n = 202). Independent predictors were identified by multivariate Cox regression and incorporated into a nomogram. Model performance was assessed by time-dependent ROC curves, calibration, decision curve analysis (DCA), and Kaplan-Meier survival analysis, with comparison against the Sanz system. The 28-day mortality rate was 19.02% (120/631). Six independent predictors were identified: decreased fibrinogen (HR = 0.254, P < 0.001), decreased hemoglobin (HR = 0.989, P = 0.034), age ≥ 45 years (HR = 2.037, P = 0.003), Charlson Comorbidity Index score 1-3 (HR = 1.877, P = 0.005), white blood cell count > 10 × 109/L (HR = 3.151, P < 0.001), and absence of early PLT-CF combined transfusion within 72 hours (HR = 2.713, P < 0.001). The nomogram showed excellent discrimination in the training cohort (28-day AUC = 0.890, C-index = 0.858) and validation cohort (AUC = 0.945, C-index = 0.913), with good calibration (Hosmer-Lemeshow P > 0.05) and net clinical benefit (DCA). High-risk patients had significantly higher 28-day mortality than low-risk patients (training: 67.1% vs. 8.1%; validation: 64.4% vs. 3.8%; both P < 0.0001). The nomogram significantly outperformed the Sanz risk stratification (AUC: 0.890 vs. 0.693 in training, 0.945 vs. 0.759 in validation; DeLong P < 0.001). In conclusion, this nomogram integrating early PLT-CF combined transfusion effectively predicts 28-day mortality in APL and is superior to the traditional Sanz system, aiding early identification of high-risk patients and individualized decision-making.