ATRA treatment in the emergency department is associated with reduced early mortality in acute promyelocytic leukemia—a real-world multicenter retrospective cohort analysis

Early hemorrhagic death in acute promyelocytic leukemia (APL) remains a major, preventable cause of mortality. Although guidelines recommend empiric all-trans retinoic acid (ATRA) at first suspicion of APL, real-world initiation varies. We conducted a multicenter retrospective cohort study within the TriNetX U.S. Collaborative Network to evaluate the impact of early ATRA initiation. Adults with laboratory-confirmed APL (PML-RARA) presenting to the emergency department (ED) were categorized by ATRA initiation within 24 h (early) versus after 24 h (delayed). The primary outcome was 30-day mortality; secondary outcomes included major hemorrhage, ICU admission, thrombosis, and sepsis. Among 596 patients, 137 (23%) received early ATRA. After 1:1 propensity score matching (<i>n</i> = 137 per group), early ATRA was associated with lower 30-day mortality (10.2% <i>vs</i> 26.2%) and reduced major hemorrhage, while other outcomes did not differ. The absolute mortality risk reduction was 16%, yielding a number-needed-to-treat of seven. Early ED ATRA initiation substantially improved survival in PML-RARA-confirmed APL.