Management of thrombocytopenia and anticoagulant therapy in patients with hematological malignancy on chemotherapy: a binational prospective study (TAT study).

Anticoagulant use in patients with hematological malignancies treated on intensive chemotherapy represents a management challenge because of concomitant thrombocytopenia. This prospective multi-center cohort included 100 patients with hematological malignancies on anticoagulation. The aims of the study were to assess the incidence of WHO grade ≥ 2 bleeding, describe physician management strategies during thrombocytopenia (platelet count < 50 × 109//L), and examine short-term outcomes and risk factors for bleeding and thrombosis. Median patients age was 60 years and median duration of severe thrombocytopenia was 16 days. The 30-day cumulative incidence of WHO grade ≥ 2 bleeding was 29.3% (95% CI 19.4-39.8), grade 4 bleeding was 7.2% (95% CI 2.8-14.2) and incidence of thrombus recurrence/progression was 6.2% (95% CI 2.2-13.3). No deaths occurred. The majority of patients received full-dose anticoagulation with a high platelet transfusion threshold. Half of the bleeding episodes grade ≥ 2 occurred with platelets counts between 20 and 50 × 109/L. Longer period of full-dose anticoagulation during thrombocytopenia was associated with increased bleeding risk (16 days [IQR: 6-29] for participants who presented ≥ grade 2 bleeding versus 7 days for those who did not [IQR: 2-14], p < 0.001). So was a HAS-BLED score ≥ 3 (HR = 9 [4.1-20], p < 0.001). Multiple myeloma diagnosis was associated with lower bleeding risk versus other hematological malignancies (HR = 0.2 [0.0-0.9], p = 0.05). Our study underscores the complex trade-off between preventing thrombotic events' progression or recurrence and avoidance of bleeding. We highlight specific clinical scenarios and consider different risk factors. Future randomized controlled trials are required for these complex situations to achieve a rationalization of their management.