Analysis of bleeding outcomes in patients with hypoproliferative thrombocytopenia in the A‐TREAT clinical trial

AbstractBackgroundDespite prophylactic platelet transfusions, hypoproliferative thrombocytopenia is associated with bleeding; historical risk factors include hematocrit (HCT) 25%, activated partial thromboplastin time 30 s, international normalized ratio 1.2, and platelets5000/μL.MethodsWe performed a post hoc analysis of bleeding outcomes and risk factors in participants with hematologic malignancy and hypoproliferative thrombocytopenia enrolled in the American Trial to Evaluate Tranexamic Acid Therapy in Thrombocytopenia (A‐TREAT) and randomized to receive either tranexamic acid (TXA) or placebo.ResultsWorld Health Organization (WHO) grade 2+ bleeding occurred in 46% of 330 participants, with no difference between the TXA (44%) and placebo (47%) groups (p = 0.66). Overall, the most common sites of bleeding were oronasal (18%), skin (17%), gastrointestinal (11%), and genitourinary (11%). Among participants of childbearing potential, 28% experienced vaginal bleeding. Platelets ≤5000/μL and HCT < 21% (after adjusting for severe thrombocytopenia) were independently associated with increased bleeding risk (HR 3.78, 95% CI 2.16–6.61; HR 2.67, 95% CI 1.35–5.27, respectively). Allogeneic stem cell transplant was associated with nonsignificant increased risk of bleeding versus chemotherapy alone (HR 1.34, 95% CI 0.94–1.91).DiscussionThe overall rate of WHO grade 2+ bleeding was similar to previous reports, albeit with lower rates of gastrointestinal bleeding. Vaginal bleeding was common in participants of childbearing potential. Platelets ≤5000/μL remained a risk factor for bleeding. Regardless of platelet count, bleeding risk increased with HCT < 21%, suggesting a red blood cell transfusion threshold above 21% should be considered to mitigate bleeding. More investigation is needed on strategies to reduce bleeding in this population.